DRX Merge
Symptoms of glucocorticoid insufficiency
- anorexia - nausea and vomiting - fever - joint/muscle pain - postural hypotension
Toxicity of some older 2nd generation antihistamines
- inc risk of sudden death due to ventricular arrhythmia (tornadoes de pointers; inhibition of K+ channel in heart) - risk negligible in newer drugs; most OTC
The Pharmacology of Anti- inflammatory and Immunosuppressant Agents
-H1 Receptor Antagonists "Antihistamines" Histamine mediates •allergic and inflammatory reactions •gastric acid secretion •neurotransmission in parts of the brain Found in almost all tissues (lung, skin, gastric mucosa, CNS) Stored in secretory granules in mast cells and basophils (inactive and bound to heparin and an anionic protein) Histamine Release from Mast Cells and Basophils • Bradykinin • Complement components C3a and C5a • Antigen interaction with IgE • Basic drugs - Curare - Opioids - Vancomycin Histamine Release from Enterochromaffin-like Cells in Gastric Wall • Neurotransmitters - ACh • Hormones - Gastrin Discovery of Histamine Receptor Subtypes Development of "antihistamines" in 1940s with no effect on gastric acid secretion • Development in 1970s of histamine antagonists of gastric acid secretion with no effect on histamine-induced smooth muscle contraction Diphenhydramine and Loratadine are H1 receptor antagonists IP3DAGCA2+ Ranititnde is a H2 receptor antagonist cAMP H1 Recepter Activation should jusually increase permability, dilate via endothelial NO release, SM constrictio of larger arteries and veins and bronchioles (neural reflex increases sensitivity of asthmatics). Activating the H1 receptor causes sensory nerve ending stimulation of itch, flare, and pain, CNS arousal of histamionergic fibers from tuberomamillary nucleus diffusely to cortex. Intradermal Injection of Histamine: Redspotdueto vasodilation • Wheal: swelling of red spot due to increased vascular permeability • Flare due to axonally mediated reflex vasodilation Histamine-induced Reactions inclue itching, rhinitis, conjuctvites, angioedema, hives, and hypotension (direct drug effect i.e. morphine). Effects of H2 receptor activation: Stimulation of hydrogen ion secretion by gastric parietal cell, vascular smooth muscle relaxation, increate heart rate and force of contraction. H1 ANTAGONIST: 1st Gen: Diphenhydramine Benadryl 2nd Gen: Loratadine Claritin Aryl -X-Y-C-C-N 1st Gen: High selectivity for H1 vs H2, weak selectivity for H1 vs others (local anesthetic, antimuscarinin, a-adenrenegic, 5-HT), access to CNS sedative effect. Effect of H1 Antihistamines: Appetite, sedation, hypotension, dizziness, dry mouth, urine retention, sinus tachycardia. Use of H1 antagonist: ithcing, rhinitis, conjunctivity, hives, mastocytosis, myelogenous leukemia. DO NOT USE H1 ANTAG for astham or tpye 1 hypersensitivity. 1st Gen H1 can be used for nasuea, motion sickness, sedative. ATROPINE-LIKE toxicity of 1st gen h1: fixed dilated puples, dry mouith, tachycardia, urine retention, hallucinations, and fever bc blocks Ach. Advantages of 2nd gen H1: higher selectivity for H1 over others so less antimuscarinic effects, lower csedation Carboxylate residue limits access to CNS. Toxicity of 2nd gen: Ventricular arrhythmia, tosades de pointes, inhibition of K+ channel in heart. NSAIDS & Aspirin-like Drugs • Large class of agents used to treat inflammation, pain and fever. • Mechanism of action of agents is primarily mediated via inhibition of cyclooxygenase (COX), the enzyme involved in the production of prostaglandins (Pgs), thromboxanes (TxA) and prostacycline • Agents are called: nonopioid, nonnarcotic analgesics; antipyretic analgesics; nonsteroidal anti-inflammatory drugs (NSAIDs) - Inhibits COX/P's and Ts but not LOX Ls - PGE2: Fever, Pain, Edema -PGE2 + PGF2a: Increased GI motility, GI cytoprotection, decreased gastric secretion, uterine contract -Prostacyclin: inhibit platelet agrreagation, vasodilation TXA2: stimulate platelet aggregation, vasoconstriction Cyclooxygenase Pathway: COX-1 •Constitutively expressed •Gastric cytoprotection •Vascular homeostasis •Platelet aggregation •Kidney function COX-2: •Induced by cytokines, growth factors & tumor promoters •Associated with inflammation & cancer •Also constitutively expressed in brain, kidney, bone and gastrointestinal tissues Nonselective, Traditional NSAIDS (tNSAIDS): • Ibuprofen, Naproxen (& many others) • older agents that inhibit both COX-1 and COX-2 isozymes. • COX-2 inhibition is thought to mediate the antipyretic, analgesic and anti-inflammatory actions. • COX-1 inhibition largely (not entirely) mediates many adverse effects. COX-2-selective agent: • Celecoxib • designed and marketed to selectively inhibit COX-2 isoenzyme to provide antipyretic, analgesic and anti-inflammatory actions with less adverse effects (GI effects) Nonopioid, Nonnarcotic Analgesic agent: Acetaminophen • Antipyretic and analgesic activity • No anti-inflammatory activity Acetaminophen • Relatively weak cyclooxygenase inhibitory action compared with salicylates and NSAIDs • In analgesic doses its potency, elimination half- life, and duration of action are similar to salicylic acid (major metabolite of aspirin). • Lacks peripheral side effects observed with other cyclooxygenase inhibitors (no platelet effect, little GI toxicity) Analgesic and antipyretic actions due to reversible cyclooxygenase inhibition in the CNS as compared to peripheral sites • Actions at CNS receptors • Lack of anti-inflammatory effect possibly results from its poor ability to inhibit COX in the presence of peroxides found in sites of inflammation Therapeutic Uses: • Mild-to-moderate pain, fever • NOT an anti-inflammatory and less effective than NSAIDs in some conditions Analgesia •Antipyresis - e.g. chronic inflammatory conditions like rheumatoid arthritis • Preferable antipyretic-analgesic for patients at increased risk of NSAID toxicity Acetaminophen Biotransformation Metabolite causes centrilobular hepatic necrosis Risk increased by: CYP2E1, CYP3A4 inducers more quinone formed Alcohol CYP2E1 induction and hepatotoxicity Glutathione depletion less quinone detoxified •Drug of choice for children with viral infections & patients intolerant to aspirin and other NSAIDS "Traditional" NSAIDs • Aspirin* • Nonacetyatedsalicylates* • Ibuprofen*,naproxen*,fenoprofen, flurbiprofen • Diflunisal •Diclofenac,etodolac,sulindac,ketorolac • Meloxicam,piroxicam • Nabumetone • Indomethacin Salicylates: Aspirin irreversibly inactivates cyclooxygenase NSAIDS: Propionic Acid Derivatives: Ibuprofen (Advil, Motrin) (t1/2 ~ 2 h). Naproxen (Aleve, Naprosyn) (t1/2 ~ 14 h) Antipyresis Analgesia: Anti-inflammatory • Treatment of chronic musculoskeletal disorders • Do not arrest the progress of the disease or induce remission (often used in combination with DMARDS) • Reduce elevated body temperature • Relieve mild to moderate pain (headache, dysmenorrhea & dental procedures and pain originating from joints, skeletal muscle) Antipyretic Effect of NSAID • Decrease in elevated body temperature - Sweating - Increase in cutaneous blood flow • Response to reduced PgE synthesis in hypothalamus • Avoid salicylates in children with fever from viral illness due to association with Reyes'syndrome - Acetaminophen as preferred antipyretic-analgesic Analgesia •Inhibit peripheral PGE2 synthesis •Possible inhibition of constitutively expressed COX-2 in the dorsal horn of the spinal cord •Relieve mild to moderate pain •Limited maximal effect Opiod hass higher potency and max efficacy than NSAID + acetaminophen Anti-inflammatory reduce the inflammatory response to mechanical, chemical or immunological stimuli by inhibiting production of prostaglandins primarily by COX-2. Another proposed anti-inflammatory mechanism of salicylates includes the inhibition of activation of the transcription factor NF-kB - Decreased synthesis of proinflammatory mediators such as TNF-a - Decreased synthesis of COX-2 Inflammation of the joints - Rheumatoid, psoriatic, IBD-related arthritis - Osteoarthritis - Ankylosing spondylitis Therapeutic Uses of Aspirin Cardiovascular Use Aspirin is used prophylactically to decrease the risk of thromboembolic disorders such as transient ischemic attacks, and myocardial infarction Increased Bleeding Time •Inhibition of thromboxane synthesis o prolongs bleeding time by inhibiting normal formation of a platelet plug and platelet-induced acceleration of coagulation. o Aspirin and tNSAIDS prolong bleeding time o Aspirin irreversibly inactivates COX-1 in platelets o A single analgesic dose of aspirin doubles bleeding time for the life of the platelet (4 - 7 days) o Acetaminophen does not affect platelet function -81 mg/day: antiplatelet 650-100mg: analgesia 3 g/day: anti-inflammatory Renal Toxicity • Sodium retention and edema - NSAIDs - risk greater in patients with renal and CV disease. • Papillary necrosis and interstitial nephritis - "Analgesic nephropathy" - Acetaminophen and NSAIDs GI Toxicity • Most common side effect - est. 15-30% of regular users - Dyspepsia, GI bleeding, erosions, and ulcers • Risk caused by COX-1 inhibition: - reduced synthesis of gastroprotective prostaglandins in stomach wall - ulcerogenic effect of gastric acid secretion 'Aspirin Intolerance' • Bronchospasm, rhinorrhea and/or hives - INDUCED BY NSAIDS - NOT BY ACETAMINOPHEN • More common in asthmatics • Mediated by leukotrienes • Cross-sensitivity with other NSAIDS but not acetaminophen Selective COX-2 Inhibitors •Higher TI than non selective NSAIDS •Equal analgesic & anti-inflammatory efficacy with decreased risk of GI effects. COX-2 Inhibitors •No effect on platelets ROFECOXIB CELECOXIB The active center of COX-2 has a larger side pocket which can accommodate molecules with bulkier side chains than COX-1 Cox Selectivity: iC50 is much lower for COX-2 meaning higher potency juvenile and rheumatoid arthritis osteoarthritis ankylosing sponylitis primary dymenorrhea • GI Toxicity: lower risk than naproxen, and ibuprofen • Renal Toxicity: sodium retention and edema • Cardiovascular Toxicity: possible increased risk of heart attack and stroke •In platelets: there is no COX-2; TXA2 production is unchecked •In endothelial cells: COX-2 inhibition decreases PGI2; decreases PGI2-induced vasodilatation and inhibition of platelet aggregation •The risk of CV adverse effects increases with chronicity of dosing. •label contains boxed warning highlighting the risk of adverse CV events •lowest dose for the shortest period of time should be used •contraindicated for patients with cardiovascular disease •CV warning for all NSAIDs (except aspirin) Aspirin: High incidence of GI Effects; useful anti- platelet action at low doses Ibuprofen & naproxen: OTC nonselective NSAIDS with moderate effectiveness. Naproxen: longer-acting (t1/2 ~ 14 h) Celecoxib: selective COX-2 inhibitor; equal analgesic & anti-inflammatory efficacy; lower risk of GI effects; possible increased risk of heart attack and stroke
1st generation anti-histamines
1st = 1940s; diphenhydramine --> no effect on gastric acid secretion - high selectivity for H1 vs H2 - weak selectivity for H1 vs other receptors --> side effects (local anesthetic, antimuscarinic, alpha adrenergic antagonism, 5HT antagonism) - access to CNS (sedative, origin of neuroleptic class of antipsychotic agents) - other effects = prevent nausea/vomiting, motion sickness, sedative hypnotic (OTC sleep aids)
5. Describe the extracellular matrix, its molecular components and its role in repair.
3. Extracellular Matrix Formation - Layer III Granulation Tissue and ECM The extracellular matrix is the stuff between cells that gives tissues physical properties such as turgor, elasticity or rigidity; it acts as a reservoir for molecules such as growth 15-5 factors that maintain tissues; and finally it provides a scaffolding for tissue renewal (basement membrane) and provides a substratum for cells to adhere to and migrate on or within. The ECM is found as 2 distinct domains Basal Membrane - BMs are produced by epithelial cells and some mesenchymal cells and in the case of epithelial cells form a ribbon along the base of the cells to which the cells adhere and/or move along. This membrane is composed of non- fibrillary collagens, laminin, heparan sulfate, proteoglycan and other glycoproteins. It is necessary for the eventual re-epithelialization of the ulcer. The Interstitial Matrix - as the name suggests it fills the spaces between the cells and is a predominant element in connective tissue. It consists mainly of fibrillary and non-fibrillary collagens and elastin, the adhesive glycoproteins fibronectin, and a gel of proteoglycans and hyaluronate. It becomes prominent in the layer III of the ulcer and is identified by blue staining on the trichrome stain. The ECM consists mainly of 3 groups of macromolecules that confer its physical and functional characteristics: (i) Fibrous Structural Proteins Collagens consist of a triple helix of 3 polypeptide chains that have a gly-x-y repeating sequence. About 30 chains form more than 27 distinct collagen types. Types I, II, III, V and XI are the fibrillary collagens and the most abundant; these have numerous cross linkages between adjacent molecules, a property that confers tensile strength. Type IV is non-fibrillary collagen (forms sheets) and is found in both interstitial matrix and basal membrane. Elastins The ability of tissues to stretch and recoil is conferred by elastin fibers. They are abundant therefore in structures such as aorta and large blood vessels, uterus, ligaments and skin. Elastic fibers consist of a central core of elastin surrounded by a micro-fibrillary network of fibrillin, a large MW glycoprotein which acts as a scaffold for elastin assembly. Cross-linkages between the elastin fibers confer elasticity. (ii) Cell Adhesion Proteins (CAMs) - glycoproteins that link cells and ECM components to one another. The following are the more important examples: Cadherins, "calcium - dependent adherence proteins", connect the plasma membrane of adjacent cells, forming cell junctions. Cadherins are in turn linked to the cytoskeleton by and catenins. Cell-cell interactions mediated by cadherins and catenins play a major role in regulating cell motility, proliferation and differentiation. 15-6 Integrins are the major family of cell surface receptors that mediate cell attachment to ECM by binding to CAMS such as fibronectin and laminin. They are transmembrane glycoproteins made up of multiple types of and chains generating more than 20 heterodimers. Integrin receptors organize the actin cytoskeleton of cells to induce shape alterations and cell movement; they are also involved in the transduction of signals from the ECM to the cell interior. Fibronectin is a large adhesive glycoprotein produced by fibroblasts, endothelial cells, monocytes and other cells. It binds to ECM proteins and to cells via specific domains. It exists in a tissue form and a plasma form which is transported to wound sites and binds to fibrin. Laminin is the most abundant glycoprotein in BMs. It has a cross shaped structure and spans the BM and binds specific cell surface receptors to collagen type IV and heparan sulfate within the matrix. (iii) Proteoglycans and Hyaluronan Proteoglycans consist of core proteins linked to one or more disaccharide polymers, called glycosaminoglycans. They are named according to the predominant disaccharide, eg heparan sulfate, chondroitin sulfate and dermatan sulfate. They have roles in regulating ECM structure and permeability. Hyaluronan is a large molecule consisting of numerous repeats of a simple disaccharide. It associates with various core proteins and surface receptors. It binds water to give tissues turgor pressure. It is abundant in the matrix of cells that are actively migrating. 4. Remodeling of ECM - Layer IV Fibrous Scar In layer IV, the final stage of the repair process, the ECM rich granulation is gradually transformed to the relatively avascular scar. The ECM of this layer consists predominantly of collagen fibers. The remodeling is achieved by a process of degradation of collagen and other ECM proteins by enzymes called metalloproteinases (collagenases, gelatinases and stromelysins) and resynthesis. Collagen bundles, newly synthesized by the fibroblasts become aligned plate-like along the lines of physical stress. Secreted adhesion molecules such as SPARC and the thrombospondins play a role by regulating angiogenesis here and remodeling the ECM. Contraction of fibroblasts in this and more superficial layers draws the edges of the ulcer defect together and smooth muscle bundles from the adjacent stomach wall become anchored in the collagen lamellae. Cellular elements of blood vessels undergo apoptosis. Epilogue: With successful treatment (acid suppression and antimicrobials) the surface layer is permitted to regenerate along newly created basal membrane; this is followed by differentiation and restoration of a normal or simplified surface mucosa. The granulation tissue (layers II and III) involutes. All that remains of the ulcer is a patch of collagenous scar connecting the previously interrupted muscle bundles of the stomach wall. At endoscopy everything may appear normal except for slight narrowing of the stomach if the ulcer had been located in the tube-like pylorus. At exploratory laparotomy 15-7 the external surface of the stomach may appear completely normal or show puckering of the serosa or fibrous adhesions overlying the site of the healed ulcer. Figure 2. Healed chronic peptic ulcer
GABA-A receptor
5 subunits. - alpha, alpha, beta, beta, gamma - each different agonist binds a different site - ion channel (drug binds, ion passes through)
64. The opioid dosing requirements for postoperative analgesia: Are unaffected by genetic factors Are increased by hepatic and renal impairment *May be increased by more painful conditions Is highly predictable with low variability among patients Are lower after oral as compared to intravenous administration
63. Synthetic drugs classified as glucocorticoids have in common: The ability to activate phospholipase A2 and NFkB. *Affinity for a specific cytosolic receptor which, when bound by agonist, interacts with glucocorticoid response elements in DNA. Glucuronide conjugation as an activating biotransformation. The ability to inhibit synthesis of prostaglandins, but not of leukotrienes. Less selectivity for glucocorticoid as compared to mineralocorticoid effects than observed for cortisol. 62. In a patient treated orally with a chronic systemic regimen of glucocorticoids for an appropriate indication, abrupt termination can be expected to: Result in an increase in ACTH and endogenous cortisol plasma concentrations to normal levels within one week. Result in a decrease in ACTH and endogenous cortisol plasma concentrations to normal levels within one week. *Result in prolonged adrenocortical insufficiency with inadequate ACTH secretion. Have a similar risk of toxicity to that observed after two high doses of glucocorticoids, given 4 hours apart. Cause minor symptoms, none of which are life-threatening. 61. A patient with severe auto-immune disease is treated chronically with an oral regimen of a long-acting glucocorticoid. Side effects may include: A. Hepatic glycogen and triglyceride accumulation. *Osteoporosis and loss of skeletal muscle mass. Prolonged systemic treatment is NOT safe and may cause iatrogenic Cushing's syndrome; toxicities include osteoporosis with fractures, muscle wasting, hypertension, hyperglycemia, infection, impaired wound healing, cataracts, behavioral disturbances, slowed growth in children. Thickening of the skin. X Loss of abdominal fat. X Orthostatic hypotension.X 60. The primary effect of the H2 receptor antagonists, which is the basis for their major clinical indication, is: Increase in cardiac output. B. Vasoconstriction. C. *Inhibition of gastric acid secretion. H2 receptor antagonists, for which ranitidine is prototypic, are highly selective for H2 as compared to H1 receptors. Their primary clinical indications are prevention and treatment of gastrointestinal ulcers, gastric acid hyper-secretory conditions, and gastro-esophageal reflux disease. (These drugs will be discussed further in the Gastroenterology Module.) D. Sedation. E. Bronchodilation. 59. An effect of a selective H1 receptor antagonist in a patient experiencing an allergic reaction is to: A. *Block histamine-induced release of NO from the vascular endothelium. B. Block histamine-induced smooth muscle relaxation mediated by an increase in cAMP. C. Block histamine-induced increase in vascular permeability mediated through muscarinic receptors. D. Block histamine-induced tachycardia mediated by an increase in cAMP. E. Inhibit histamine release.
Cyclophosphamide
DNA alkylating agent used for immunosuppressive and cancer tx
Identify the major therapeutic applications of nicotinic cholinergic agonists and antagonists.
I. Autonomic Nervous System Anatomy A. Parasympathetic 1. Gangliatypicallyclosetotargetorgan 2. Transmitter a) Ganglionic synapse: Acetylcholine released by preganglionic neuron, and acting at neuronal nicotinic receptors of postganglionic neuron b) Postganglionic neuron: Acetylcholine released by postganglionic neuron, and acting at muscarinic acetylcholine receptors on target organ B. Sympathetic 1. Ganglia mostly near spinal cord 2. Adrenal medulla: sole organ innervated directly by preganglionic sympathetic neurons 3. Transmitter a) Preganglionic neuron: Acetylcholine, acting at neuronal nicotinic receptors of postganglionic neuron b) Postganglionic neuron: Norepinephrine, acting at adrenergic receptors (Exceptions: sweat glands innervated by cholinergic sympathetic fibers; dopamine in renal vasculature smooth muscle) c) Adrenal medulla: Epinephrine, released into circulation II. AcetylcholineReceptors A. Nicotinic Acetylcholine Receptors 1. Structure: Nicotinic acetylcholine receptors are ligand-gated ion channels, with 5 structurally homologous subunits surrounding a central ion pore. Includes at least two (depending upon subtype) acetylcholine binding sites located at α/β subunit interfaces (see illustration). 2. Function: Nicotinic acetylcholine receptors are excitatory receptors that transport Na+, K+, and sometimes (depending upon the specific nicotinic receptor subtype) Ca2+. The receptor responds rapidly to acetylcholine on a time scale of milliseconds. Prolonged (seconds to minutes) exposure to agonists causes receptors to enter a refractory desensitized state in which agonist remains bound, but the channel recloses. After removal of agonist, the receptor recovers from desensitization, also on a time scale of seconds to minutes 3. Subtypes of the nicotinic acetylcholine receptor (differing in subunit composition) vary somewhat in sensitivity to cholinergic agonists and antagonists and permeability to Ca2+. a) Skeletal Muscle b) Neuronal (1) Autonomic ganglia (both sympathetic and parasympathetic) (2) CNS(multiplesubtypes) 4. Nicotinic agonists (direct-acting cholinomimetics) a) Acetylcholine (1) Endogenous neurotransmitter; highly selective for nicotinic acetylcholine receptors (2) Quaternary ammonium; does not diffuse across membranes (3) Activates both nicotinic and muscarinic receptors (4) Rapidly inactivated by hydrolysis into choline and acetic acid by the enzyme acetylcholinesterase at the synapse, and by nonspecific esterases in blood b) Carbamylcholine (1) Quaternaryammonium (2) Activates both nicotinic and muscarinic receptors (3) Acetylcholinesterase-resistantanalogofacetylcholine c) Nicotine (1) Tertiaryammonium,resultinginincreasedskinpermeability.Crosses the blood-brain barrier into the CNS. (2) Selective for nicotinic receptors (3) Drugofabuse (4) Acute toxicity (Generally occurs from ingestion of nicotine-based insecticides or ingestion of tobacco products by children) (a) Rapid onset of symptoms, including abdominal pain, nausea, diarrhea, disturbed hearing and vision, weakness, mental confusion (b) Stimulation of both branches of autonomic nervous system via activation of ganglionic receptors produces a complex mixture of sympathetic and parasympathetic effects. Initial autonomic stimulation can progress to ganglionic blockade as ganglionic receptors become desensitized (c) Central stimulation, which in severe poisoning may progress to convulsions, coma, respiratory arrest. (d) Skeletal muscle depolarization and contractions, which in severe poisoning may progress to paralysis (including respiratory paralysis), due to a combination of sodium channel inactivation and nicotinic acetylcholine receptor desensitization 5. Nicotinic antagonists a) Skeletalmusclerelaxants (1) Nondepolarizingrelaxants (a) Prototype: Tubocurarine ("curare;" no longer in clinical use) Others: atracurium, cisatracurium, mivacurium. Main differences are in onset and recovery time and route of elimination. (b) Nondepolarizing skeletal muscle relaxants act as competitive antagonists of acetylcholine muscle nicotinic receptors, resulting in flaccid paralysis (c) The muscle relaxant effect may be indirectly antagonized by acetylcholinesterase inhibitors, resulting in increased levels of endogenous acetylcholine, which competes with the antagonist. This is sometimes used to speed postsurgical recovery of respiratory function (2) Depolarizingrelaxants(succinylcholine) (a) Depolarizing relaxants are actually nicotinic agonists. Succinylcholine is the only such agent in clinical use, but any nicotinic agonist is capable in principle of acting as a depolarizing relaxant. (b) Initial muscle fasciculations (disorganized muscle fiber contractions) due to non-synchronous activation of muscle nicotinic receptors progresses to flaccid paralysis due to a combination of acetylcholine receptor desensitization and voltage-gated sodium channel inactivation. (c) The primary advantage of succinylcholine is rapid onset and short duration of action. Succinylcholine is resistant to acetylcholinesterase, but is rapidly hydrolyzed by plasma cholinesterase. Patients typically recover muscle tone within a few minutes after termination of infusion. Some patients with genetic atypical plasma esterase (frequency about 1 in 2000) show exaggerated effect and prolonged paralysis, sometimes for hours. (d) Acetylcholinesterase inhibitors are generally not effective in (3) reversing succinylcholine paralysis, since they further increase agonist stimulation of receptors Clinical uses of skeletal muscle relaxants (a) Surgical muscle relaxant (in conjunction with general anesthesia) (b) Short-acting agents (e.g. succinylcholine) are sometimes used to facilitate setting of fractures of extremities or mandible. (c) Prevention of laryngospasm during tracheal intubation (e.g. succinylcholine) (d) Prevention of trauma from involuntary muscle contractions in electroconvulsive therapy (e.g. succinylcholine) (4) Adverseeffectsofskeletalmusclerelaxants (a) Nondepolarizing: Some, but not all, nondepolarizing blockers can produce hypotension by blocking ganglia. Nondepolarizing blockers chemically related to d-tubocurare can also stimulate release of histamine, which can also contribute to hypotension, as well as producing pseudo-allergic reactions. (b) Depolarizing (succinylcholine) (i) Prolonged paralysis in patients with atypical plasma esterase (ii) Hyperkalemia, with potentially life-threatening cardiovascular effects, due to excessive release of intracellular K+ through nicotinic acetylcholine receptor channels. Predisposing factors include denervating injury or disease, burns, prolonged immobilization. (iii) Malignant hyperthermia due to runaway Ca2+ release in skeletal muscle of patients with this genetic disorder. Inhalation anesthetics are also a predisposing factor. b) Ganglionic blockers (e.g. trimethaphan) (1) Ganglionic blockers are relatively selective inhibitors of nicotinic receptors of autonomic ganglia. Most are competitive antagonists of acetylcholine, although some also produce noncompetitive inhibition. (2) Because ganglionic blockers inhibit both sympathetic and parasympathetic ganglionic transmission, their physiological effects depend upon the predominant tone (sympathetic or parasympathetic) of a particular organ. For example, the predominant tone of the resting heart is parasympathetic, so ganglionic blockers tend to increase heart rate, whereas the predominant tone of the vasculature is sympathetic vasoconstriction, so ganglionic blockers tend to produce vasodilation and a decrease in blood pressure. The decrease in blood pressure is greater in a standing posture, due to greater sympathetic tone while standing. (3) Clinical applications: Ganglionic blockers were once used for treatment of hypertension, but because the block all autonomic function, they have a high incidence of side effects, and have been mostly replaced by more specific agents. Modern use is mainly limited to circumstances in which it is advantageous to block autonomic reflexes: (a) Sometimes used in patients with acute dissecting aortic aneurysm, to reduce blood pressure and inhibit autonomic reflexes that elevate blood pressure (b) Also occasionally used to lower blood pressure to reduce bleeding in surgery (c) Used for control of spinal hyperreflexia (exaggerated autonomic reflexes associated with spinal damage)
Leukocyte, Role, and WBC type for ICAM-1 and VCAM-1 adhesion molecules
ICAM-1 - Leuko = CD11/CD8 integrins - Role: adhesion, arrest, migration - WBC type = PMN, Monocytes, Lymphs VCAM-1 - VLA-4 integrin - also adhesion - Eos, Monos, Lymphs
Identify the major clinical uses of the adrenergic agonists and antagonists.
II. Adrenergicagonists A. Direct-acting adrenergic agonists (most do not cross blood brain barrier, and are not orally active). Note that selectivity is not absolute. 1. Epinephrine: α1 = α2; β1 = β2; endogenous agonist released into bloodstream by adrenal medulla 2. Norepinephrine: α1 > α2 > β1 >> β2; endogenous sympathetic transmitter 3. Phenylephrine:α1>α2 4. Clonidine:α2(centrallyactive) 5. Isoproterenol: β1 = β2 6. Albuterol:β2>β1 7. Dobutamine:"β1"(actuallyhascomplexmixtureofactions,alsoincludingα1 agonism and antagonism, but β1 effect predominates) 8. Dopamine:specificD1dopaminereceptors,β1>α1;endogenousagonist B. Indirect-acting sympathomimetic drugs (do not have strong direct activity at adrenergic receptors, but produce physiological effects by increasing level or availability of endogenous adrenergic transmitters/hormones 1. Tyramine: Present in foods, especially cheese, red wine, produced in small quantities by gut flora. Normally degraded by MAO, but orally active when MAO is inhibited—can precipitate hypertensive crisis by releasing norepinephrine from nerve terminals. Can be converted to octopamine and stored in synaptic vesicles, replacing norepinephrine. Octopamine is said to be a "false transmitter" because it can be released, but has little action at adrenergic receptors. Therefore, long-term administration of MAO inhibitors can impair the function of the sympathetic nervous system. 2.Dextroamphetamine:Releasesnorepinephrineanddopamine,alsoacts directly (α + β1). Orally active, marked CNS effects: wakefulness, anorexia, euphoria, locomotor stimulation, stereotyped behavior. High abuse potential. Psychotomimetic with prolonged abuse. Primary clinical use for ADHD 3.Methylphenidate:Effectssimilartoamphetamine.Primaryclinicalusefor ADHD 4. Cocaine: Inhibits reuptake of norepinephrine and dopamine. Centrally active, with effects similar to amphetamine. High abuse potential. Primarily an illicit drug. Can precipitate fatal cardiovascular and CNS events, sometimes at moderate doses. 5. Ephedrine:Releasesnorepinephrineanddirectlyactivatesαand β receptors. Orally active. Less CNS stimulation than amphetamine. Controversial ingredient of many "nutritional supplements." Use restricted by FDA due to adverse effects. 6. Pseudoephedrine: Similar to ephedrine. Widely used over-the-counter decongestant. 7. Tricyclicantidepressants:Centrallyactive.Inhibitcatecholamineand serotonin reuptake. Also have antimuscarinic side effects at high doses. 8. MAOinhibitors:increasecatecholaminelevelsinnerveterminals;potentiate effects of tyramine. C. Hemodynamic effects of adrenergic agonists depend on: 1. Relativepotencyforadrenergicreceptortypes 2. Doseofagonist 3.Distributionofreceptortypesinvascularbedsdeterminesbalancebetween α1-mediated vasoconstriction and β2-mediated vasodilation a. Skin & mucosa: α dominates b. Splanchnic & renal: α, β, dopaminergic c. Skeletal muscle: α + β
• Describe the limits imposed on your practice by regulations enforced by the FDA and the DEA.
III. The Controlled Substances Act: U.S. Drug Enforcement Agency, http://www.dea.gov/pubs/csa.html The stated purpose of the Controlled Substances Act of 1970 is to minimize the quantities of drugs available to persons who are prone to abuse them. Control procedures are initiated by the Department of Health and Human Services (DHHS), by the Drug Enforcement Administration (DEA), or by petition from any interested person or organization. A. Schedules: Substances controlled under the Act are classified by "Schedules" according to criteria of abuse potential, acceptance in current therapeutic practice, and risk of dependence (see Table on the next page of this document, http://www.deadiversion.usdoj.gov/schedules/). The DHHS and DEA consider the following factors when assigning a drug to a specific schedule: 1. Its actual or relative potential for abuse. 2. Scientific evidence of its pharmacological effect, if known. 3. Current scientific knowledge about the substance. 4. Its history and current pattern of abuse. 5. The scope, duration, and significance of its abuse. 6. Its risk, if any, to public health. 7. Its dependence liability. 8. Whether the substance is an immediate metabolic precursor of another substance that has already been controlled under the Act. B. Control Methods: The controls imposed by the Act are enforced by the FDA, which is in the DHHS, and by the DEA, which is in the Department of Justice. The control methods for the manufacturing, obtaining, and selling of controlled substances include: 1. Registration of handlers (e.g., manufacturers, importers, pharmacies, hospitals, physicians, dentists, research workers, etc.). 2. Maintenance of inventories and other pertinent records. 3. Limitations on manufacturing quotas. 4. Restrictions on distributions from manufacturer to purchaser (especially Schedule I and II drugs). 5. Limitations on dispensing to patients. 6. Limitations on imports and exports. 7. Security conditions for drug storage (especially Schedule I and II drugs). 8. Periodic reports to DEA of transactions in all drugs in Schedules I and II (and some in Schedule III). 9. Criminal penalties for illicit trafficking (defined as the unauthorized manufacture, distribution by sale or gift otherwise, or possession) in controlled substances. C. Prescription Monitoring Programs: Because of the increased abuse of opioid drugs and deaths associated with their misuse, many states, including Massachusetts, have implemented databases on opioid prescriptions that prescribers are obligated to check before issuing a prescription for an opioid drug product. Additional regulations were passed in Massachusetts in 2016, including a limit of 7 days of opioid products for first-time prescriptions, educational programs in schools for teenagers, and treatment approaches for patients who present with an opioid overdose.
Arachnidonic acid metabolism
Leads to leukotrienes & lipoxins, or COX products (prostaglandins PGE PGF, thromboxanes TXA TXB, Prostacyclin PGI)
Opioid receptor agonists
Morphine Met-Enkephalin (+ other endogenous peptides)
4. Know the molecules responsible for cell adhesion to the endothelium and neutrophil chemotaxis.
Step 3. Emigration, accumulation, activation of leukocytes Leukocyte infiltration into inflamed tissue is the most important histologic sign of inflammation. Acute inflammation is most commonly associated with neutrophils. The sequence of leukocyte recruitment to tissue includes: (A) margination, (B) rolling, (C) tight adhesion, (D) migration across vessel wall. Leukocyte transmigration occurs most prominently in post-capillary venules and, to a lesser extent, in the capillaries themselves. Leukocyte transmigration does not occur in arteries, arterioles, or larger veins. A. Margination. In normally flowing blood, the red and white cells within small vessels stay in the central portion of the vessel. There is typically a plasma layer, relatively depleted of cells, in the blood flowing along the vessel walls. In order for leukocytes to exit the bloodstream, they must first move to the margin of the bloodstream, and come into contact with the vascular wall. This is called "margination". B. Rolling. Once leukocytes have marginated, they may physically contact endothelial cells of the vascular wall. In order to initiate leukocyte transmigration across the vascular wall, the leukocyte and the endothelium must adhere to each other. All of the blood leukocytes can potentially fall out of laminar flow yet only very specific types of leukocytes will actually transmigrate into the tissue. In most types of acute inflammation, neutrophils predominate in the first day and are gradually replaced by monocytes and lymphocytes. The initial adherence of leukocytes to endothelium is weak and is mediated by a family of molecules called selectins. The leukocytes roll on the endothelial cell layer rather than abruptly stopping. The expression of these selectins is mediated by cytokines. During rolling, there is cell-to-cell contact, allowing the passing leukocyte to interact with adhesion molecules on the surface of the endothelium. Rolling leukocytes may move into the tissue, or the leukocyte may cease rolling once it has passed out of the area of inflammation and continue into the venous circulation. The specificity of cellular inflammation is, at least in part, regulated during the rolling phase. C. Tight adhesion. With appropriate pairing of the adhesion molecules on the neutrophil and the endothelium, leukocytes will tightly adhere and emigrate out of the bloodstream. Tight adhesion is due to the ability of a family of integrin molecules to rapidly increase their molecular avidity for integrin ligands on the endothelial cell surface. Once tightly adherent, the shear force of the blood is not sufficient to cause the cell to continue to roll. The important adhesion molecules, integrins and selectins, are found in the book in table 3-3. D. Migration across the vessel wall. During this process the leukocyte actually migrates between two endothelial cells. It requires the leukocyte to interpose itself between two endothelial cell junctions which re-form after passage. After migrating between two endothelial cells, the leukocyte moves through a small area of extracellular matrix at the site of the basement membrane. Lastly, the leukocyte migrates between collagen fibrils until it is in the extravascular space. Last year during the immunology course of video was shown demonstrating this process. Only minutes are typically required for passage of a leukocyte through the vascular wall. There are several important neutrophil chemotactic agents including (1) bacterial products, (2) components of the complement system, most notably C5a, and (3) products of the lipoxygenase pathway of arachidonic acid metabolism, especially leukotriene B4 (LTB4), (4) CXC chemokines such as interleukin 8 and (5) platelet activating factor.
Discuss the rational use of these drugs in the treatment of acute and chronic patients
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drugs to slow absorption of local anaesthetics
a1 agonist; epinephrine (vasoconstriction)
belladona alkaloids
atropine & scopolamine muscarinic antagonists, prevent parasymp response by blocking M receptor used when a reduction in parasymp tone is desired
why does our patient with infection get green-colored sputum?
because of neutrophil degradation of bacteria
process of prostaglandin/leukotriene/lipoxin formation + Where to inhibit (part of acute inflammation)
cell membranes of phospho lipids --(phospholipase)--> arachidonic acid arach acid --> (A) cyclooxygenase & (B) 5-lipoxygenase (A) COX -->--> - PGI2 (prostacyclin), - TXA2 (thromboxane A2), - PGD2 & PGE2 (B) 5-Lipoxygenase-->--> - Leukotrienes - lipoxins *inhibition*: - glucocorticoids inhibit phospholipase (first step) - cox 1 & cox 2 inhibit cyclooxygenase - leukotriene rec. antagonists block action of leukotrienes
Cl_T
elimination RATE of drug from body = (dA/dt) / Cp = (0.693/t1/2)*Vd = Kel * Vd = Cl_R + Cl_NR
carcinoma
epithelial cells malignant neoplasm - glandular = adenocarcinoma - squamous = squamous cell carcinoma - urothelium = urothelial carcinomas
Bradykinin
example of biologically active protein: effects: - increases vascular permeability - causes contraction of non-vascular smooth muscle - dilation of blood vessels - pain
principal mediators of inc. vascular permeability
hist, 5HT C3a, C5a leukotrienes C4, D4, and E4
IL-6
interleukin 6 synthesis: - macrophages (esp Kupffer cells in liver) - fibroblasts - endothelial cells - also activated by T cells biological actions: - stimulates synth of *acute phase reactants* in liver - systemic effects = fever - growth of antibody producing B lymphocytes
infusion rate constant
k0 = Cpss * Cl_T
Fcy elimination
monocytes, macrophages, and dendritic cells express Fc receptors that bind to Fc regions of mAbs and fusion protein drugs Fcy elimination also responsible for *immune complex elimination* (or opsonized cell elim) ---> IC's often form in response to administration of protein drugs; these are eliminated by RES & Fcy (RES = reticuloendothelial system, same as mononuclear phagocyte system)
drugs to restore BP
overdose of hyoptensive agents - a1 agonist spinal damage or anaesthesia - a1 agonist cardiogenic shock - B1 agonist, DA, dobutamine antihypertensive = a2 agonist (not a first line therapy, clonidine
point of care (POC) lab tests
performed by clinicians at bedside - easy to perform and interpret - fingerstick glucose, guaiac, urine pregnancy test, etc. - some tests need to be made POC in some situations where a rapid test result is needed - the lab still has to oversee the operational and copmliance aspect of POC testing
5 adhesion molecules to know
1. P-selectin 2. E-selectin 3. Glycam-1 4. ICAM-1 5. VCAM-1 Select CAM!
principal mediators of fever
- TNF - IL-1 - IL-6 - Prostaglandins TNF, IL1 and IL6 act via prostaglandins on the hypothalamic thermoregulatory center to *reset the set point*
Lecture 39: Pathology Overview
-First sign of anoxic cell injury: cell swelling -Reversible injury example is cytoplasmic vacuoles, chromatin clumping, cytoplasmic inclusions, and cellular edema -Irreversible injury includes pkynosis, rupture of cell membrane, karyolysis, and karyorrhexis -Splenic infarct: coagulative necrosis. -Ischemic infarct in brain: liquefactive necrosis -MI increases serum enzyme creatine kinase due to increases plasma membrane permeability from cell membrane rupture. -Squamous epithelium lining endocervial is an example of metaplasia -Papillary projects and fibromuscular storm lesion is an example of a epithelial and stroll hyperplasia response to stress in prostate resection sample. -Carb metabolism disorder causing increased hepatic glycogen and hypoglycemia is a result of absence of glucose-6-phosphatase. -Jewish splenomegaly lysosomal storage disease would be Gauchers Disease Type I. -Stored material in cells of infant dying from impaired Skelton devoted and heart failure is dermatan sulfate -Primary vascular mechanism for edema in acute inflammation is increased vascular permeability -Inflammatory response of a bronchospasm and edema due to bee sting is from a mast cell -Cell death from conversion of cell to acidophilic body + loss of nucleus but share is same will by just apoptosis -Yellow sclerae means abnormally high bilirubin in liver -Neutrophils are unable to recirculate once they leave the blood stream -Apriation of 1.050 means it is an effusion resulting from a serous exudate. -Acute apendicisti and acute inflame shows high neutrophils in blood. -Acute inflammation and fever is due to cytokines made by monocytes/macrophages -Infection by mycobacterium tuberculosis and peritoneum nodules will consist of macrophages and giant cells. -Bening tumor is low mitotic, nucleoli, encapsulation, different (normal N/C ration) -Injury with high ALT: Hepatocellular -Hepatic toxicity from acetaminophen overdose: NAPQI
Identify the major adverse effects of the adrenergic agonists and antagonists
4. Baroreceptor-mediatedautonomicreflexeffectsonheartrateandcardiac output may amplify or oppose the adrenergic receptor mediated effects of adrenergic drugs on heart rate. Most notably, systemic administration of norepinephrine normally results in a reflex, vagal-mediated decrease in heart rate even though the direct β1-mediated effect of norepinephrine is to increase heart rate. D. Therapeutic uses of adrenergic agonists 1. Cardiovascular a. Nasal decongestants (α1) Phenylephrine, pseudoephedrine b. Slowing absorption of local anesthetics (α1; epinephrine) c. Resuscitation after cardiac arrest (probably mainly α1; epinephrine) d. Restoring blood pressure Overdose of hypotensive agents (α1) Spinal damage or anesthesia (α1) Cardiogenic shock (β1; dopamine, dobutamine) e. Antihypertensive (α2) (not a first-line therapy) Clonidine 2. Ophthalmology a. Mydriasis (radial muscle α1) Epinephrine, phenylephrine b. Treatment of wide angle glaucoma (α1 for vasoconstriction; α2 for reduced secretion) Epinephrine, phenylephrine 3. Allergicdisorders a. Asthma (β2, airway smooth muscle relaxation) Terbutaline, albuterol b. Acute allergic reactions and anaphylactic shock (β2, airway smooth muscle relaxation and inhibition of release anaphylaxis mediators by mast cells; α1, vasoconstriction to maintain blood pressure) Epinephrine 4. Otheruses a. Obstetrics: Delay premature labor (uterine β2) b. Reducing symptoms of opioid withdrawal (α2) c. Treatment of attention deficit disorder (central effect) amphetamine, methylphenidate E. Toxicity & side effects of adrenergic agonists 1. Vasoconstriction,ischemia(α1) 2. Hypertensivereactions—cerebralhemorrhage(α1) 3. Reboundnasalcongestion(α1) 4.Withdrawalsyndromefromα2agonists(reversalofhemodynamiceffects i.e., hypertension and tachycardia) 5. Cardiacventriculararrhythmias(β1) 6. Tachycardia(β1) 7. Myocardialischemia(β1) 8.Increasedriskofsevereasthmaexacerbationanddeathwithlong-termuse of long-acting β-agonists (β2) 9. CNSstimulation(mechanismunclear) III. Adrenergic antagonists Α. α-Adrenergic antagonists 1. Phentolamine (α1 + α2) 2. Phenoxybenzamine (α1 + α2; irreversible) 3. Prazosin(α1) 4. Yohimbine(α2) B. β-Adrenergic antagonists ("β-blockers") 1. Propranolol (β1 + β2; enters CNS) 2. Carvedilol (β1 + β2 + α1) 3. Labetalol (β1 + β2 + α1) 4. Pindolol (β1 + β2; partial agonist; some intrinsic activity) 5. Metoprolol(β1) 6. Esmolol(β1;ultra-shortacting;t1/28min) 7. Butoxamine(β2) C. Therapeutic uses of adrenergic antagonists 1. α1-Antagonists a. Treatment of hypertension (not a first-line therapy) b. Treatment of pheochromocytoma (to reduce α1 mediated hypertension from circulating adrenergic agonists released by tumor, administered before a β-blocker) c. Treatment of Raynaud's disease (to reduce digital vasospasm) d. Treatment of heart failure (reduction of vascular resistance) e. Treatment of benign prostatic hyperplasia (to relieve difficulty in urination by decreasing bladder smooth muscle tone) 2. β-Antagonists a. Management of heart failure (carvedilol and metoprolol now approved by FDA) b. Reducing mortality after myocardial infarction (probably by reducing ventricular arrhythmias) c. Treatment of hypertension (reduction of cardiac output; inhibition of renin production). Note that a meta-analysis found no benefit of β-blocker monotherapy in hypertension for endpoints of mortality, stroke, or MI (Bangalore et al., 2007, J. Am. Coll. Cardiol.) d. Relief of angina (to control cardiac oxygen demand) e. Treatment of cardiac arrhythmias (to increase AV nodal refractory period) f. Treatment of hyperthyroidism g. Treatment of anxiety states, particularly "stage fright" h. Migraine prophylaxis i. Treatmentofopen-angleglaucoma j. Treatment of pheochromocytoma (It is important to block α1 receptors before administering β-blockers, as β2 blockade of circulating epinephrine will exacerbate hypertension.) D. Toxicity & side effects of adrenergic antagonists 1. α-Antagonists a. Postural hypotension (due to inhibition of α-mediated vasoconstriction) b. Reflex effects arising from postural hypotension (less severe with α1 selective agents such as prazosin) 1) Reflex tachycardia 2) Myocardial ischemia (increased oxygen demand from reflex tachycardia) 3) Salt and water retention and peripheral edema (due to reflex β1 stimulation of kidney renin-angiotensin system) c. GI stimulation (abdominal pain, nausea, exacerbation of peptic ulcer) d. Inhibition of ejaculation 2. β-Antagonists ("β-blockers") a. Bronchoconstriction b. Bradycardia c. Exacerbation of angina and increased risk of sudden death after abrupt withdrawal d. Fatigue e. Cold extremities f. Potentiation of epinephrine vasoconstriction g. Precipitation of heart failure due to inhibition of adrenergic compensation (However, as noted above, β-blockers used appropriately are beneficial in treatment of heart failure) h. May predispose toward new-onset diabetes (Clinical studies do not support earlier concerns regarding possible dangers of β-blockers in insulin-dependent diabetics).
V. Pharmacokinetics of Protein Therapeutics (Biologics)
A. Antibody Absorption 1&2-9 1. Biologic proteins, such as monoclonal antibodies (mAb), have negligible oral bioavailability due to their molecular weight (MW), size, hydrophilicity, variable solubility, limited chemical stability, and gastrointestinal degradation. They are administered by parenteral routes (intravenous, subcutaneous, or intramuscular). 2. After IM or SC injection, systemic absorption of mAb consists of travel through interstitial spaces into lymphatic vessels by a process called convective transport, a "solvent drag" or sieving, through the lymphatic vessel membrane. Lymphatic capillaries have a higher permeability than blood capillaries for transport of large molecules, due to the absence of a well-defined basement membrane and the presence of clefts between the endothelial cells. Antibodies in the lymphatic system equilibrate with the bloodstream when the thoracic duct drains into the left subclavian vein. After SC injection, mAb absorption proceeds slowly; the time to reach maximal plasma concentration ranges from 2 to 8 days because lymphatic flow rate is slow (~120 mL/h). B. Antibody Distribution 1. Biologics, especially mAbs, have a small volume of distribution approximately the size of plasma volume (~ 4L / 70kg) due to their size, charge, and tight target binding. 2. mAbs, distribute into peripheral tissues from the vasculature by convective transport through pores in capillary walls, as well as by transcytosis (fluid-phase endocytosis and receptor-mediated endocytosis) from the bloodstream into extracellular spaces. a. Convective transport of mAb from lymph or blood into tissue spaces depends on the fluid-tissue hydrostatic pressure gradient, flow rate of fluid moving into the tissue, and on the sieving effect of paracellular pores in the membranes that make up the lymphatic or vascular vessels. Sieving is determined by the size and shape of the pores and by the size, shape, and charge of the antibody. b. Fluid-phase endocytosis (pinocytosis) is a nonspecific process driven by the concentration of mAb on the extracellular side of a membrane. It does not require ligand binding to cell surface membranes, and is a non-competitive process. Fluid-phase endocytosis is responsible for mAb entering into endothelial cells and other tissues. Once the mAbs are inside the cells, they may undergo FcRn recycling, which either transports mAbs to the interstitial fluid or back into the circulation (see below). c. Receptor-meditated endocytosis of mABs may result from interaction of the Fab binding domains of the antibody with target epitopes found on the cell surfaces (see below). C. Antibody Elimination Biologics are removed from circulation or interstitial fluid via several mechanisms: nonspecific endocytosis, degradation by proteolysis, target-mediated clearance, FcRn-mediated clearance, FcR-mediated clearance and formation of immune- complexes. 1. Proteolytic degradation: Once inside cells, the mAbs may be eliminated by intracellular lysosomal proteolytic degradation. Non-specific proteolysis may occur widely in the body or may be limited to specific organs and tissues. For example, hepatocytes take up biologics via carrier-mediated transport or endocytosis and metabolize these agents by the same catabolic pathways as endogenous proteins. Kidneys may also contribute to metabolism of biologics that are small enough (<60kDa) to undergo glomerular filtration. 2. Three catabolic pathways important for mAb elimination include the reticular endothelial system (RES); a saturable, target-mediated pathway (Fab-mediated); and a non-specific, first-order, Fc-mediated pathway. a. The reticuloendothelial system (RES), predominantly phagocytes (monocytes, macrophages, endothelial cells) in the liver, spleen,and lymph nodes plays a role in the elimination of biologics, as well as endogenous IgG molecules. b. Fab-mediatedelimination:asaturable,target-mediatedclearancepathway mediated by the specific interaction between the Fab region of the antibody and its pharmacological target. Receptor-meditated endocytosis of IgG, and mAb may proceed following interaction of the Fab binding domains of the antibody with target epitopes found on the cell surfaces. This type of endocytosis is a form of target- mediated disposition resulting from the interaction of the drug and its pharmacological target (e.g. a target receptor) and serves as a significant contributor to the kinetics of both antibody distribution and elimination as well as the pharmacodynamic effect of the drug. c. Fc-mediated elimination: a nonspecific elimination pathway for both endogenous IgGs and exogenous therapeutic mAbs involving either FcRn or Fcγ receptors. FcRn receptors: A large fraction of endocytosed IgG molecules, including therapeutic mAbs, are not sorted to the lysosome for catabolism but are redirected to the cell surface and released into plasma or interstitial fluids. The recycling is mediated by the Brambell receptor (FcRn) in endothelial cells which binds to IgG and mAbs with pH-dependent affinity. FcRn in the acidified environment of the early endosome, binds to internalized IgG and forms an IgG-FcRn complex. The IgG-FcRn complex is not delivered to the lysosome but is sorted to the cell surface for fusion with the cell membrane. The FcRn receptor has no affinity for IgG at physiological pH and, upon fusion of the sorting vesicle with the cell membrane, the IgG- FcRn complex dissociates and free IgG is released into extracellular fluid. This FcRn-mediated antibody recycling provides an explanation for the long half-life of IgG and many mAbs in the blood (3 weeks). The FcRn is expressed in a wide variety of cells and tissues in addition to the vascular endothelium including: monocytes, macrophages, dendritic cells, hepatocytes, epithelial cells of the intestine, renal proximal convoluted tubules and upper airways. The FcRn-mediated clearance pathway is non-specific and is a common pathway used by both endogenous IgG and exogenous mAbs. Fc receptors: FcRs, another type of receptor that binds to the Fc region of IgG, is expressed on many cell types, including monocytes, macrophages, dendritic cells, neutrophils, natural killer (NK) cells, B cells, and hepatocytes. Biologic agents with an Fc domain (mAbs, and fusion proteins) may bind to FcR receptors on these cells and become internalized and subsequently degraded by lysosomes in RES. FcR may be also be responsible for the elimination of mAb-antigen immune complexes or cells opsonised by the mAb. However, the exact mechanism of action of FcRs in antibody clearance is not fully understood. 3. Immunogenicity:formationofimmune-complexes(IC) An exogenous protein therapeutic agent, such as a mAb, may be viewed by the body as foreign and trigger immune responses that result in the generation of endogenous antibodies against the protein drug. The formation of antidrug antibodies (ADA) may impact on both the pharmacokinetics as well as the pharmacodynamics of a protein therapeutic agent. In terms of pharmacodynamics, biologic-ADA complexes cause a loss of drug response as well as the induction of hypersensitivity reactions. Pharmacokinetic impact of biologic-ADA complexes includes a likely increase in the clearance rate of the biologic agent. Clearance of biologic-ADA immune complexes (ICs) is mediated through the RES, predominantly phagocytes in the liver and spleen, where the ICs are internalized and undergo lysosomal degradation. Red blood cells may facilitate this clearance by binding to the ICs in the bloodstream and aiding in their delivery to the RES.
III. Distribution of Drugs from the Circulation into Tissues
A. Causes of tissue differences in rates of drug uptake 1. Bloodflow:distributionoccursmostrapidlyintotissueswithhighbloodflow (lungs, kidneys, liver, brain) and least rapidly into tissues with low flow (fat). 2. Capillary permeability: distribution rates are relatively lower into the CNS because of tight junctions between capillary endothelial cells, endothelial cell efflux transporters, insignificant membrane aqueous pores, and juxtaposed glial cells around endothelium (blood brain barrier). B. Causes of differences in drug tissue/blood concentration ratios at equilibrium 1. Dissolution of lipid-soluble drugs into adipose tissue 2. Binding of drugs to intracellular sites 3. Plasma protein binding: many drugs reversibly bind to albumin in plasma; extent of binding dependent on affinity, number of binding sites and drug concentrations; drug bound to albumin is not filtered by renal glomerulus but may be cleared by proximal renal tubule and liver; binding reduces free drug available for distribution into tissue; many drug interactions based on displacement from binding sites. C. Apparent Volume of Distribution (Vd) 1. Theamountofdruginthebodycanberelatedtoit'splasmaconcentration by a proportionality constant that reflects the apparent fluid volume into which the drug distributes (Vd) 2. The extent of drug distribution in the body is characterized by its apparent volume of distribution; this pharmacokinetic parameter is expressed in volume units (e.g. liters) or as a percent of body weight (volume in liters divided by body weight in kg times 100%); Vd is one determinant of the plasma concentration of a drug (Cp); Cp = Amount of drug in the body/ Vd. 3. Fluid compartments of the body vary with body weight (BW); for a 70-kg healthy subject these values in liters and as percent of body weight are: plasma 3 1 (4%), extracellular water 12 1 (17%), total body water 41 1 (58%). Knowing these values helps in the interpretation of Vd values for drugs. 4. Vd is determined in a pharmacokinetic study from extrapolated plasma concentration at "zero-time" (Co) after intravenous administration of a dose: Vd = Dose/Co. These values are measured in preclinical and human studies during drug development. 5. Vd values can be predicted from chemical characteristics of a drug, e.g. high MW protein therapeutics are restricted to plasma (Vd about 4% BW); highly lipophilic small MW drugs have Vd s typically exceeding not only total body water but also body weight (Vd >100% BW) due to extensive accumulation in fat with higher concentrations than in plasma. 6. Vd although generally proportional to body weight is also affected by body composition, so the value can differ in very lean or obese patients from that in patients with a normal body mass index. 7. Theplasmaeliminationhalf-lifeofadrug(thetimetoreducethe concentration by one-half) is directly proportional to Vd, and inversely proportional to total clearance (ClT); for a given ClT, the higher the Vd, the longer the elimination t1/2.
What triggers release of histamine from enterochromaffin-like (ECL) cells in gastric wall?
ACh Gastrin
carbamoylcholine (carbachol) vs. acetylcholine
ACh = endogenous, rapidly inactivated by AChE carbachol = exogenous analog, *esterase-resistant*, same effects but lasts longer
COUNSELING PATIENTS
Asking about use — Surveys have found that the majority of patients who use herbal medicines and other forms of complementary and alternative medicine do not disclose this to their health care providers [87]. Of complementary alternative medicine users who did not disclose such use to their clinicians, 46 percent reported that a reason for not telling their clinician was "it wasn't important for my doctor to know" and 57 percent also reported that "the doctor never asked." There are several important reasons for asking patients about the use of herbal medicines: ● Herbs are pharmacologically active and therefore can positively and negatively impact patient health. Positive effects may include improvement of disease-specific outcomes. Negative effects may include adverse effects and drug-herb interactions. For these reasons, the Joint Commission on Accreditation of Healthcare Organizations in the United States now requires that herb and supplement use be recorded as part of the medication list in the hospital medical record [88]. ● Discussion of herbal medicine use may open dialogue about patient concerns that may be amenable to management with well-studied conventional therapies. For example, further questioning of a patient who uses multiple supplements such as garlic, Vitamin E, and Coenzyme Q-10 might reveal intense anxiety of myocardial infarction due to a family history of premature heart disease. Measuring cardiovascular risk markers and educating the patient about conventional cardiac risk factor reduction and therapy could then be initiated. ● Providers may need to consider herb-drug interactions when prescribing and dosing conventional medications. Asking about herb use can be done during the medication history by asking: "What prescription medications, over-the-counter medicines, vitamins, herbs, or supplements do you use?" This encourages communication by demonstrating the practitioner's interest in the information and willingness to discuss herb and supplement use. It is also appropriate to put a question like this into medical intake questionnaires filled out prior to the appointment. When the ingredients of a commercial herbal product are unknown, practitioners can consult the Dietary Supplement Labels Database or the product's website. Patients who use herbs should be asked about their reasons for use. Motivation for herb use is often not based on scientific data [17]. Of herbal users surveyed, 72 percent stated they would continue using supplements despite a negative government scientific study. Instead, patients often get their information about herbs from family, friends, advertisements, and the Internet. Patients can be directed to Medline plus (see above) for free evidence-based information about many herbal products. Advising patients — The schema in the table (table 8), can be used to develop an approach to advising patients about an herbal product based upon the evidence for that product's quality, efficacy, and safety [53,58]. If there is strong evidence for an herbal product's quality, safety, and efficacy, it may be reasonable to proactively recommend that product and closely monitor the patient for effectiveness and safety. Given the frequent uncertainty in herbal product quality, which impacts the product's efficacy and safety, few (if any) herbal products fit these criteria. By contrast, it would be appropriate to discourage use of products when there is strong evidence for either lack of quality, inefficacy, or harmfulness. Examples of products that should be discouraged include traditional herbal medicines known to contain toxic heavy metals, St. John's wort when taken with medicines metabolized by cytochrome P450 3A4 (CYP3A4), and ephedra-related products [62]. The majority of herbal products do not fall into either the recommend or discourage category due to uncertain, insufficient, or contradictory evidence regarding quality, efficacy, and/or safety. For these products, clinicians should counsel and caution patients regarding the uncertainty of the evidence. The impact of uncertain quality on efficacy and safety should be emphasized. If the patient chooses to proceed with an herbal product, a plan should be agreed on for ongoing monitoring for both benefits and adverse effects. These discussions should be documented clearly in the medical record. Clinicians need to take into account patients' individual health conditions, concerns, and preferences [89]. Patients seeking or already using herbal treatments should have an appropriate evaluation for their condition such that proven conventional treatments can be offered for any diagnosed conditions [90]. For the patient who decides to use an herbal product against the advice of his or her clinician, a nonjudgmental attitude should be maintained. This will allow channels of communication to remain open for monitoring and future discussion. A patient's decision to pursue herbal therapy against medical advice or in lieu of conventional therapy is not an acceptable justification for a clinician to terminate care of a patient. Choice of brand — Patients who use herbs often ask their providers what brand should be used. Lack of regulatory reform in the herbal industry makes it difficult for the clinician to provide an informed response. One option is to recommend brands that have been tested by independent sources such as Consumer Labs (www.consumerlab.com) and found to meet minimum quality criteria. For ethical reasons, supplements sold through practitioners' offices or multilevel marketing plans should be discouraged.
Cp and Vd equation
Cp = amount in body / volume Vd = Dose / C0
Hexamethonium
Nicotinic Antagonist ganglionic blocker?
Conflict of Interest Why Does It Matter?
Preservation of trust is the essential purpose of policies about conflict of interest. Physicians have many impor- tant roles including caring for individual patients, pro- tecting the public's health, engaging in research, report- ing scientific and clinical discoveries, crafting professional guidelines, and advising policy makers and regulatory bodies. Success in all these functions depends on oth- ers—laypersons, professional peers, and policy leaders— believing and acting on the word of physicians. There- fore, the confidence of others in physician judgment is of paramount importance. When trust in physician judg- ment is impaired, the role of physicians is diminished. Physicians should make informed, disinterested judgments. To be disinterested means being free of per- sonal advantage. The type of advantage that is typi- cally of concern in most situations involving physicians is financial. When referring to conflict of interest, the term generally means a financial interest that relates to the issue at hand. More specifically, a conflict of inter- est can be discerned by using a reasonable person stan- dard; ie, a conflict of interest exists when a reasonable person would interpret the financial circumstances per- interest is not tantamount to saying her or his judg- ment is affected, nor does it constitute an accusation of bias or prejudgment. The presence of a conflict of interest is no judgment about the appropriateness or value of the relationship that engenders the conflict in a particular situation. For example, physicians employed by the pharma- ceutical industry may improve health and save more lives than they could in many lifetimes of clinical prac- tice. However, this does not alter the presence of a conflict of interest if making judgments about drugs or vaccines produced by the physician's employer. Some erroneously take a financial interest that qualifies as a conflict of interest to be an allegation that their think- ing is tainted. They seek to defend their scientific integrity and adherence to evidence, and aver that the monetary payment they received or financial interest they hold could not possibly influence their scientific or clinical judgment. They may be right, and they miss the point. If a reasonable person would perceive that the financial circumstances could potentially influence their judgment, a failure to acknowledge and respond Opinion Corresponding Author: Harvey V. Fineberg, MD, PhD, Gordon and Betty Moore Foundation, 1661 Page Mill Rd, Palo Alto, CA 94304 (harvey.fineberg @moore.org). jama.com taining to a situation as potentially sufficient to influ- ence the judgment of the physician in question. Invoking a reasonable person standard for deter- mining conflict of interest introduces a fundamental ele- ment of subjectivity into the concept. If a conflict of in- terest is what a reasonable person would perceive as a conflict of interest, then to refer to the appearance of a conflict of interest is redundant. When the reasonable person standard is used, a conflict of interest is based on the perception of a reasonable person of what finan- cial circumstances could exert influence on the judg- ment of an individual in question. Even when a specific, objective dollar level of payment may be selected as a threshold for defining a conflict of interest, the reason- ing behind that dollar level is ultimately subjective, and it should pass the reasonable observer test for poten- tial influence. As president of the Institute of Medicine (now the National Academy of Medicine) for 12 years, I dealt with scores of cases of conflict of interest among potential members of committees that were convened to provide policy advice. An individual's conflict of of feelings of reciprocation is the reason you receive pre- printed return address labels with charitable solicita- tions. Included in about one-third of pieces of non- profit direct mail, these small gifts substantially improve donation response rates.1 Even a stamped return enve- lope (compared with a business reply envelope) will prompt significantly more physicians to respond to a pro- fessional survey.2 If the presence of a conflict of interest is ultimately subjective—based on the judgment of a reasonable person—it is also situational, that is, dependent on the specific financial circumstances and relationship to the specific role of the person involved. The standards for adjudging a conflict of interest may also be bound by time and place, having different meaning in different cultures and at different moments in history. In practical terms, policy about conflict of interest should be specific to the role, and clear about the fi- nancial thresholds and time frames that count, explicit about interests of individuals related to the person in question, and describe specific remedies, such as disclosure or exclusion. The policies should be public, The aim, throughout, is to preserve and protect public trust in the independence and objectivity of physicians involved in the exercise in question. to the conflict of interest threatens to erode the trust that undergirds the value of professional judgment and expertise. Many people tend to underesti- mate the influence of even relatively small financial relationships, and the fact of a relationship can be as salient as the amount of money involved. The power (Reprinted) JAMA May 2, 2017 Volume 317, Number 17 1717 Copyright 2017 American Medical Association. All rights reserved. Downloaded From: http://jamanetwork.com/pdfaccess.ashx?url=/data/journals/jama/936200/ by a Boston University User on 05/06/2017 1718 JAMA May 2, 2017 Volume 317, Number 17 (Reprinted) jama.com Opinion Viewpoint readily understood, and applied evenhandedly. The basis for any ex- ceptions should be spelled out. The aim, throughout, is to preserve and protect public trust in the independence and objectivity of phy- sicians involved in the exercise in question. Physicians, like others, have many types of possible financial interests. As clinicians, their basic income may be salary, capita- tion, or fee-for-service. A surgeon paid fee-for-service clearly has a financial stake in whether a patient agrees to surgery. This is transparent to the patient and may be readily balanced by seeking a second opinion from a disinterested expert. Consultant fees, honoraria, and other financial interests may arise in relation to other professional roles. Authors of a published article, for example, may disclose an institutional affiliation, sources of other relevant income, and funders of the research. What is acceptable for an author and remedied by disclosure may differ from more lax standards required for a reviewer who is merely advising the edi- tors and from more stringent standards for selecting an editorialist who will interpret the meaning of the research for clinical practi- tioners. Standards for disclosure and inclusion may be even more stringent for experts chosen to develop professional guidelines or regulations that can directly affect practice. In setting financial thresholds for conflict of interest, policies to guide disclosure should be explicit and public. What relationship to a payer and financial level triggers disclosure, discussion, and pos- sible remedy? If not contemporaneous, for how long in the past is a financial relationship deemed relevant? Should the financial inter- ests of a spouse, a parent, a minor child, and a sibling be considered as pertinent as those of the individual involved? In general, the an- swers to these questions should be guided by the reasonable per- son standard. To preserve public trust, it is better to lean toward more disclosure rather than less, while also protecting individual privacy and avoiding tangential matters. For example, the financial inter- ests of a cousin or a niece are of less interest than those of a spouse or sibling. Scrupulous attention to conflict of interest will not avoid all sources of influence on judgment extraneous to the evidence at hand. Bias in the sense of a preformed judgment can grow out of many sources other than financial interest. Friendships, institu- tional associations, previous study and reflection, knowledge of a field, and life experience can all produce a predisposition to ac- cept, reject, or interpret evidence in a particular way. The aim of poli- cies about conflict of interest is to expose those sources of influ- ence that stem from financial interests and to reduce the likelihood they will intrude into professional judgments. The Gallup poll reports that nurses, pharmacists, and physicians are among the professions most trusted by the US public.3 Espe- cially at a time when the place of science is challenged in public policy and decision making, it is incumbent on the health professions to champion their reliance on evidence and disinterested expertise. Ad- herence to carefully considered, transparent, and evenhanded poli- cies on conflict of interest can help physicians earn and maintain their trusted place in the minds of the public and policy makers.
toxicity of muscarinic agonists
SLUDGE (BHB) salivation lacrimation urination diarrhea GI upset emesis (vomiting) bronchoconstriction hypotension bradycardia
Alcohol
[18] Alcohol (ethanol) is metabolized mainly in the liver and to a lesser extent in the brain and GI tract. Alcohol metabolism - mainly through cytosolic alcohol dehydrogenase (ADH)] - decreases NAD and generates toxic acetaldehyde; NAD is also used by mitochondrial aldehyde dehydrogenase (ALDH) to convert acetaldehyde into acetic acid, which is broken down into water and carbon dioxide in the mitochondrial respiratory chain. NAD is required for fatty acid oxidation, therefore its depletion results in fat accumulation. Acetaldehyde is a carcinogen, which acts by interfering with DNA replication and repair. It also contributes to incoordination, memory impairment and sleepiness, and can cause facial flushing, nausea, and rapid heart beat. Variants of the ADH and ALDH enzymes in different individuals determine the acetaldehyde level and hence the level of 'tolerance' to alcohol. Fast ADH and/or slow ALDH result in higher levels of acetaldehyde, lowering tolerance to alcohol and thereby protecting against alcoholism (alcohol dependence / high alcohol consumption). 50% of Asians have a slow ALDH variant and, therefore, low alcohol tolerance. [19, 20] The level of alcohol in exhaled breath is proportional to the alcohol level in the blood and, therefore, is used by the police as a Breath Test for suspected drunk driving ( 80 mg/dL blood). Blood alcohol levels of 200 and 300 mg/dL and higher cause, respectively, drowsiness, stupor (greatly diminished responsiveness), and coma with possible respiratory arrest. High alcohol consumption leads to accidents, homicides, suicides, and personal violence. Acute alcoholism (one-time high alcohol consumption) affects mainly the central nervous system (depression of neuronal centers, including respiration regulators, hence the respiratory arrest at very high alcohol levels). Sometimes reversible liver and stomach damage occurs, e.g., fat accumulation in hepatocytes ("fatty change"), and/or acute gastritis and ulceration. Chronic alcoholism (repeated long-term high alcohol consumption) causes major health problems, and affects about 15 million people in the US, who are referred to as alcoholics. Chronic alcoholism affects the liver and gastrointestinal tract as well as the cardiovascular system. The liver shows fatty change and alcoholic hepatitis (inflammation of the liver), which progresses to liver fibrosis and, finally, cirrhosis - irreversible replacement of hepatocytes by scar tissue. This impairs blood flow through the liver and gives rise to portal hypertension, with large swollen veins (varices) in the GI tract. These varices may rupture, resulting in internal bleeding with life-threatening complications. Bleeding due to gastritis or gastric ulcers may also occur. The inflammatory changes in the liver greatly increase the risk of liver cancer. And poor liver function also leads to cognitive decline. Chronic alcoholism may also injure the myocardium, a condition called alcoholic cardiomyopathy. Fetal alcohol syndrome can result from consumption of even small amounts of alcohol during pregnancy, especially in the first trimester). Affected infants show microcephally (abnormally small head), facial abnormalities, growth retardation, and reduced mental functioning. Fetal alcohol syndrome affects about 3 per 1000 children born in US.
prazosin
alpha 1 antagonist
phenylephrine
alpha 1 selective agonist a1> a2
phentolamine
alpha ANTagonist (a 1 and 2)
leiomyoma
benign tumor of smooth muscle
glaucoma
beta blockers reduce fluid accumulation M2/M3 move fluid out-->want to agonize a2 reduces sympathetic tone and increases fluid outflow (loss of B2 tone)? B2 relaxes the cilliary muscle and is bad because it increases fluid accumulation
codeine Agonist Agonist pro-drug converted to morphine (only like 10%)
hepatic: CYP2D6 (variability in metabolizers) (CYP3A4 and glucuronide metabolites are inactive) 48-56% first pass
LC-E
leuktrienes arachidonic acid metabolite via lipoxygenase pathway bronchospasm, increased vascular permeability
Clinical Laboratory Compliance Clinical laboratories in the U.S. are regulated by Clinical Laboratory Improvement Act 1988 (CLIA 88), which mandates medical director oversight of clinical labs, use of FDA-approved reagents and instruments, and periodic inspections. Clinical laboratories are inspected by either the CAP or the Joint Commission. In addition, blood banks are inspected by the Food and Drug Administration.
Rational Approach to Interpretation of Laboratory Test Results Test interpretation is a skill necessary for appropriate medical decision-making. In an ideal world, all results communicated by the laboratory would truly reflect what is happening in the patient. However that is usually not the case, and test results have to compiled with patient history, physical examination, and radiographic findings in making the most correct diagnosis. Just like pathologists have to use test performance statistics in deciding what is the best methodology, reagent, or instrument to bring to their laboratory. Clinicians also use these same statistics in helping to decide patient management or deciding which tests to perform. A poor sensitivity or poor specificity is not necessarily a bad thing depending on the context. For instance it is optimal for a screening test to have good sensitivity however the specificity may not be important. Whereas it is optimal for a confirmatory test to have good specificity however sensitivity may not be important. Especially with health care costs coming into greater scrutiny, judicious ordering of tests will be needed where in the ideal world an appropriate number of tests is ordered to make a diagnosis without exceeding costs. The pathologist can be helpful in recommending what new tests to order and best algorithms for cost effective test ordering in the workup of specific diseases. Lastly, the laboratory is not always right. When there are results that are not what you expect given the history, physical examination, or radiographic findings contact the pathologist to communicate your concerns before acting on a laboratory result. Discorrelations between laboratory results and the clinical picture can happen as the result of ordinary mistakes such as mislabeled specimens. But they can happen as the result of unusual circumstances such as a female patient who has a positive serum HCG indicating pregnancy, however a negative urine pregnancy test and negative transvaginal ultrasound. Such a patient should have a high suspicion for a heterophile antibody causing a false positive serum HCG result. Upon discovery of such, heterophile antibodies have to be neutralized before running any additional immune based assays. Conclusions The clinical laboratory plays many roles in aiding the clinician in patient management. In addition to direct patient management, the laboratory serves as a resource for quality assurance, evidence-based medicine, and translational research. Utilizing the laboratory will enhance your medical education and your practice.
Effects of H2 receptor activation
Stimulation of H+ acid secretion by gastric parietal cell Vascular smooth muscle relaxation (only if very marked histamine inc.) Inc. heart rate and force of contraction (only if very marked histamine inc.) H2 not for allergies!
chemotaxis; recruitment; activation
TNF, IL-1, chemokines (IL-8 CXC), C3a & C5a, LTB4 PAF, bacterial products
volume of distribution
Vd = Dose / C0
What's in a CBC?
WBC HGB (hemoglobin) HCT (Hematocrit) Plt (platelets)
intracellular hormone receptors
hours gene transcription often need to displace a protein like hsp90 off of the dna binding domain so that the transcription-activating domain can go to town estrogen receptor
4 types of physiological receptors
1. Ligand gated ion channels 2. GPCRs 3. Growth factor/cytokine receptors 4. Intracellular hormone receptors
2. Discern the concepts of reversible and irreversible cell injury and cell necrosis
CELL INJURY AND CELL DEATH Causes of cell injury and necrosis Oxygen Deprivation (Hypoxia). Causes of oxygen deprivation of cells and tissues include inadequate oxygenation of the blood (due to cardio-respiratory failure), decreased oxygen carrying capacity due to anemia or rarely carbon-monoxide or cyanide poisoning and most frequently ischemia due to interruption of the oxygen and nutrient bearing blood flow to tissues by vascular disease and or luminal obstruction by thrombosis. Physical Agents. These include trauma, heat, cold, radiation and electric shock. Chemical Agents and Drugs. Cellular homeostasis can be disrupted by inappropriate exposure to any chemical, including water and oxygen, not to mention myriad pollutants and poisons. Adverse reactions from therapeutic agents including "wonder-drugs" are an increasingly recognized source of tissue injury and disease. Infectious Agents. Viruses, Rickettsiae, Bacteria, Fungi and Parasites. Immunologic Reactions. While these are generally protective, immunologic reactions are also the basis for tissue injury caused by hypersensitivity reactions to foreign antigens and autoimmune disease where immunologic reactions are directed against self-antigens. Genetic Derangements. Inherited mutations and gene variants (polymorphisms) are an important cause or contributor to cell injury and disease. An example is Sickle cell anemia, where an inherited structural abnormality of hemoglobin can lead to life-threatening ischemic injury. Nutritional Imbalances. These include protein-calorie malnutrition and vitamin deficiencies prevalent in the underdeveloped world. In developed countries nutritional imbalances are related mainly to excess, leading to obesity and diabetes, conditions that predispose to or directly cause many forms of cell injury and disease. Morphology of cell injury and necrosis Molecular changes leading to cell injury or necrosis are followed quickly by evidence of functional impairment or loss and only later by morphologic changes. Cell necrosis can be recognized at the ultrastructural level in minutes to hours but at the light microscopic level it requires hours or days to become manifest. 14-5 Reversible Injury 1) Cellular swelling is due to loss of function of the plasma-membrane energy- dependent ion pumps. It can be seen with anoxic injury in many tissues and is particularly associated with hepatocyte injury due to viral infection. The cell cytoplasm and endoplasmic reticulum is distended (by water) but cell membranes are intact. 2) Fatty change occurs in hypoxic and various forms of toxic or metabolic injury mainly in the liver. It is associated with obesity, diabetes and alcoholism. It can be caused by excessively stressing the fat metabolism process in the liver at any point from fatty acid entry to lipoprotein exit. This results in triglyceride accumulation in small and large vacuoles within the hepatocytes. Necrosis Ultrastucturally there is disruption or fragmentation of cell membranes which may form whorled aggregates called myelin bodies. A reliable morphologic characteristic of necrosis is either the complete absence of the nucleus due to karyolysis (fading) or nuclear fragmentation (karyorrhexis).The morphologic appearance of the necrotic cells under the light microscope may offer a clue to the manner of cell death: Coagulative necrosis. This pattern is typical of ischemic injury and a myocardial infarct of 2 days duration is a good example. The ghost outlines of cells are preserved due to calcium infusion and early denaturation of the structural proteins and enzymes, including lysosomal enzymes. The cytoplasm shows increased eosinophilia due to loss of RNA and fibrils and cross striations cannot be appreciated. Gangrenous necrosis is a term applied to ischemic necrosis of extremities and the bowel where it is associated with a black discoloration. If secondarily infected it may be described as wet gangrene. Liquefactive necrosis shows no ghost outlines because the dead cells have been hydrolyzed by enzymes released from ruptured lysosomes. Grossly there is only viscous liquid and later a cavity. This pattern is typical of necrosis due to bacterial infection and is also seen in infarction of the CNS. Caseous (Cheesy) Necrosis describes the gross appearance of necrosis seen in tuberculosis. Fat Necrosis. This term describes a pattern of faintly outlined necrotic cells produced by the action of free pancreatic enzymes on adjacent tissues, mainly fat. The release of fatty acids from the necrotic tissue promotes the early formation of chalky calcium deposits (soaps). Calcium deposits tend to form in all types of necrosis (dystrophic calcification) eventually, unless the debris is completely removed by macrophages. Fibrinoid Necrosis. This is a special form of necrosis usually seen in immune reactions involving blood vessels. Deposits of complexes of antigens and antibodies together with fibrin results in a bright pink amorphous material called "fibrinoid" replacing the vessel wall. An example of such an immune mediated disease is polyarteritis nodosa.
GMP guidelines
Good Manufacturing Practices 2008-2010 For dietary supplements - good that it's a new regulatory framework that companies have to follow; bad because it's still from manufacturers, not FDA + lack of enforcement provision and some companies can be exempt
Mucopolysaccharidoses (MPS 1--VII) Genetics
I H (Hurler), I S (Scheie), III, IV = autorecessive *II* (Hunter) = x-linked recessive (Hunter marks the spot with an x) hunter =/= hurler, but both are MPS
Cortisol (hydrocortisone)
- equal affinity for glucocorticoid and mineralocorticoid receptors - converted to cortisone (in kidney, salivary gland, and colon; by 11 B hydroxysteroid DHO) - cortis*one* has low affinity for MC receptors
Is parent or metabolite active for following drugs? Codeine, oxycodone, tramadol
Codeine = inactive parent, active metabolite Oxycodone = active parent, active metabolite (oxymorphone) Tramadol = active parent, inactive metabolite (thus poor metabolized = toxicity risk) Take home: polymorphism in clearance (e.g. Amount of 2D6) Mai be bad or good, depending upon effect of metabolite and activity of parent drug
drugs that are exceptions to first-order kinetics
Ethanol, Aspirin = tx levels >> Km (working @ Vmax, can't eliminate any faster) Drugs where overdose levels >> Km - e.g. acetaminophen --> gains a toxic metabolic route, no longer first-order
How is histamine stored?
In secretory granules in mast cells & basophils; inactive and bound to heparin and an anionic protein And in ECL cells in gastric wall
Mechanism of NSAID antipyretic effect
Infection = inc cytokines, inc PGE, inc thermal set point NSAID = reduce PGE synthesis in hypothalamus; dec. elevated body temp --> "fever breaks" leads to sweating, inc. in cutaneous blood flow
Lecture 37: Bacterial Metabolism and Growth
Major Features of Prokaryotes and Eukaryotes Bacteria grow in a variety of forms Bacterial Biofilms and Quorum Sensing Division 1. Cell wall extends 2.Chromosome replicates 3. Septum forms and DNA binds at the mesosom Solution to Stubborn Bacterial Infections Might Be Sweet Energy is generated through catabolism. Cellular constituents are synthesized through anabolism. Minimal growth requirements include: carbon, nitrogen, iron, etc. Growth requirements and products of metabolism are used in classification Ex. Carbon source Ex. Obligate vs. facultative intracellular growth Ex. Ability to grow in presence/absence of oxygen Ex. Ability to ferment specific sugars Catalase Test + Staphylococcus - Streptococcus Growth on MacConkeyAgar Lac -/Lac + Glycolysis(anaerobic): 2ATP TCA(aerobic): 38ATP Cytoplasmic Membrane Site of: Active transport of molecules Electron transport chain Synthesis of cell wall precursors Signal transduction Most actions at cell cell, ribosome, RNA synthesis, Folate metabolism, and DNA synthesis Peptidoglycan synthesis: soluble substrates activated, attached on undecaprenol phosphate, peptidoglucam units cross link on outside Transpeptidation reaction: MurNAC - Lys binds to second-t-last C=O D Ala (MurNAC flipped) Sites of actions of inhibitors of bacterial cell wall synthesis: Fosfomycin NAG to NAM, Cycloserin NAM to NAM, Bacitracin inhibits recycling of bactoprenol, Vancomyci, Vancomycin, Penicilin acts on B-lactam Lipopolysaccharide (LPS) is synthesized on the cytoplasmic side of the inner membrane (IM) and flipped to the periplasmic side by the ATP-binding cassette (ABC) transporter MsbA. LPS is then transported to the cell surface by the LPS transport (Lpt) pathway. This pathway consists of seven essential proteins, LptA, LptB, LptC, LptD, LptE, LptF and LptG. LPS is extracted from the IM in an ATP-dependent manner by the ABC transporter LptB2FG and transferred to LptC, which forms a complex with LptB2FG. LptC consists of a single membrane- spanning domain and a large periplasmic domain, which forms a periplasmic bridge with the soluble protein LptA and the amino-terminal region of LptD. LPS transverses the aqueous periplasmic space through this protein bridge and reaches the cell surface with the aid of the carboxy-terminal domain of LptD, which forms a β-barrel structure that is plugged by the outer membrane (OM) lipoprotein LptE. LPS is composed of lipid A, the inner and outer core oligosaccharides, and the O antigen, which is highly variable and absent in Escherichia coli K-12. The letters A-G in the figure correspond to the respective Lpt protein in the transport pathway. EtN, ethanolamine; Gal, D-galactose; Glc, D-glucose; Hep, L-glycero-D-manno-heptose; Kdo, 3-deoxy-D-manno-octulosonic acid; P, phosphate; Pi, inorganic phosphate.
Acetylcholine
Nicotinic; Muscarinic Agonist quarternary amine, doesn't penetrate cell membranes
Endogenous Peptides that agonize opioid receptors
Probably used in body for other things besides analgesia; none usable as treatments yet, but we did figure out how to prevent peptidase from degrading them so quickly. Future option? POMC (pro-opiomelanocortin) - B endorphin - MSH, ACTH Pro-Enkephalins A - met-enkephalins - leu enkephalin Pro-enkephalin B - dynorphin A Pro-Orphanin - orphanin FQ (nociceptin) (?) - endomorphins 1 and 2
Standardized safety margin & therapeutic index
SSM: (LD1 - ED99) / ED99 x 100 (I.e. 99% effective; 1% lethal) TI: LD50/ED50
fever
TNF, IL-1, IL-6, prostaglandins
melanoma mechanism
UVB-->pyrimidine dimers in DNA--> mutations or transcriptional errors --> cancer
carboxylate group charge vs amino acid charge
carboxylate = COO- (anion, acid) amine = NR4+ (cation, base)
B1 agonist side effects
cardiac ventricular arrhythmias tachycardia myocardial ischemia
mechanism for arsenic poisoning
indoor air pollutant trivalent arsenic replaces phosphates in ATP --> inhibits mitochondrial ox phos effect: acute GI, cardiovascular, CNS damage, death (if high amt ingestef); hyperpigmentation & hyperkeratosis; lung, bladder & skin cancers
laceration vs incised wound
laceration = tear or disruptive stretching from blunt object, intact bridging blood vessels (e.g. hit your head and it splits open but blood vessels still connected) incised wound = from sharp object, severed bridging blood vessels (actually cut something)
methadone u/k Agonist Agonist
synthetic codeine long 4+ hours)
meperidine u/k Agonist Agonist
synthetic morphine; high lipophilicity; (Rapidly crosses BBB) mostly ionized, rapid absorption, fast onset, wide distribution, rapid clearance from plasma short (less than 1 hour)
drug to delay premature labor
uterine B2 agonist - relax smooth muscle, stop uterine contractions
two types of mediators of acute inflammation
1. cell derived - made by cells; preformed in storage granules; de novo synthesis 2. plasma protein derived - proteins already present in plasma in an inactive form; typically produced by liver
C5a C3a complement
neutrophil chemotaxis; release of histamine
hallmark of acute inflammation
neutrophils lasts hours-days
sensitivity
out of all the actual positives, how many did the test pick up? (how well an abnormal test result detects a disease process) - high sensitivity = good for screening (want to find as many positives as possible!) TP / (TP + FN)
4. Describe the inflammatory cells and mediators in autoimmune diseases
Autoimmune diseases. Chronic inflammation is a prominent component of numerous autoimmune diseases which will be covered in greater detail in subsequent courses. The two principal cells which interact with each other are activated macrophages and T cells. There is abundant inflammatory cross talk between the cells to maintain the chronic inflammatory response. Macrophages produce cytokines such as interleukin 12 (IL-12) and tumor necrosis factor (TNF). These cytokines, in combination with antigen presentation by the macrophages, activate T cells. These activated T cells then produce additional cytokines including TNF, IL-17, and interferon gamma. The T cell-derived cytokines further activate the macrophages to result in continuous amplification of the chronic inflammatory process. B cells also become involved in this process resulting in augmented levels of immunoglobulins. Virtually all of the soluble mediators in this process, i.e. the cytokines, have been targeted for inhibition in clinical trials. Some of these, such as TNF inhibitors, are in routine clinical use for treatment of chronic inflammatory conditions. Allergic diseases. Allergic diseases have acute exacerbations, but they are chronic inflammatory conditions. Histologically, in the lungs of asthmatic patients there are numerous chronic inflammatory cells including macrophages, lymphocytes, and eosinophils. The eosinophil is the cell most closely identified with an asthmatic response. Eosinophils are also important in the clearance of parasitic infections, particularly helminths (worms). Acute phase proteins Why are we talking about something acute in the section on chronic inflammation? Acute phase proteins are rapidly increased during acute inflammation, but they stay chronically elevated unless the inflammation subsides. Acute phase proteins, also known as acute phase reactants, are present in the blood. These molecules, synthesized primarily by hepatocytes, are induced by IL-6 as well as other cytokines. Acute phase reactants may be measured clinically as an index of inflammation. Typically, either C-reactive protein is measured or an erythrocyte sedimentation rate (ESR) is measured. ESR is an indirect measure of acute phase reactants. More about mediators We have described several different mediators. A useful system categorizes these biologically active compounds into two different groups, cell derived or plasma protein derived. Cell derived mediators. These mediators are produced within the cells and are then exported to the outside world. At the start of acute inflammation, some of the mediators are already present within the cell so that they may be rapidly released. Typically these are sequestered within granules inside the cell. Examples include histamine within mast cells or serotonin inside platelets. Other cell derived mediators are synthesized de novo and may be proteins, lipids or reactive oxygen species or reactive nitrogen species. The distinction between pre-formed mediators and newly synthesized mediators has implications for how the inflammatory response is governed. Pre-formed mediators are important in the first stages of acute inflammation and acute exacerbation of chronic inflammation. Methods to block their biological activity need to be directed at preventing their release, or interfering with binding to their receptors. Newly synthesized mediators may be produced for long periods of time, even years. Consequently, they may be a part of both acute and chronic inflammation. Effective strategies for reducing the impact of these could include preventing their synthesis, such as cyclooxygenase inhibitors, or preventing them from binding to their receptors. Plasma protein derived mediators. These mediators are generated from proteins found within the plasma. The proteins are normally circulating in the blood, but they were originally synthesized within cells typically in the liver hepatocyte. Many of these proteins exist in inactive precursor forms which are larger proteins. When inflammation is initiated, proteases cleave these larger proteins into smaller proteins, which are the biologically active forms. This protein processing results in activated forms that may appear within minutes to help drive acute inflammation. However, during chronic inflammation the liver keeps producing the acute phase proteins, never slowing down. Consequently, there are increased concentrations of several proteins, termed acute phase proteins, which may be used as biomarkers for the level of inflammation.
propranolol
B (1 &2) antagonist
Adrenergic Drugs Norepinephrine - NE (adrenergic receptors) NE a1, a2, b1, b2 Dopamine D1
Sym: B1 renal, B1 heart, a1 b2 smooth muscle NE Synthesis is from tyrosine -> catechol -> DA -> NE/E : Tyrosine LDOPA DA is Presynaptic, NE reuptake into MAO or by COMT a2 is on presynaptic rec. -Agonist Potency Defines Receptor Subtypes -α Receptor EPI > NE > PE > ISO α1&α2-adrenoceptors β1 & β2-adrenoceptors β Receptor ISO > EPI/ NE > PE B1: Cardiac Force B2: Tracheal Relaxation Alpha 1 Receptor Signal Transduction via PLC Beta Adrenergic Receptor Signal Transduction via Adenylyl Cyclase a1 agonist phenylephine: PLC+ DAG+ IP3+, vascular contraction, smooth muscle contraction, arterial resistance, less venous capacitance, intestinal smooth msucle relaxation,. mydriasis, glycogenolysis, glucongegensis a2 agonist clonidine: -cAMP: low insulin, low NE, low sym tone in CNS. platelet aggregation b1 agonist dobutamine: + camp = HR, RR, AV, Renin b2 agonist: albuteral +CAMP sm relax, glycogenolysis, D21 agonist dopamine cAMP dilated renal vcas Endogenous Adrenergic Agonists E: α, β non-selective, released from adrenal medulla into blood N: α1 = α2, β1 > β2, endogenous sympathetic neurotransmitter D: D1 specific, endogenous activator of β1 > α1 Selectivity refers to a drug's ability to preferentially produce a given effect • Selectivity arises from differences in potency at different receptors or tissues NE: a1a2>B1>b2 Isoproterenol:B1/B2 Adrenergic Agonists α1 selective: Phenylephrine α2 selective: Clonidine b1+ b2: Isoproterenol β1 selective: Dobutamien β2 selective: albuterol Selectivity is not usually absolute (nearly absolute selectivity has been termed "specificity"), and at higher agonist concentrations, a drug may interact with related classes of receptors. Low Conc: E= Relaxation High: A1 occupied bc more receptors exist Adrenergic agonist specificity is relative, not absolute. Agonist ability to selectively activate specific receptors depends on dosage Low doses, selectivity is maximal High doses, selectivity declines Major Cardiovascular Effects of Adrenergic Agonists B1: CF,HR,ReninR B2: Vasodilation, low TPR A1: Vasoconstriction, high TPR Physiological Effects Dependent on - Relative potency for receptor subtype - Agonist dose - Receptor distribution determines balance between α1 vasoconstriction and β2 vasodilation - Impact of baroreflex Norepinephrine - α1 vasoconstriction = increased MAP = increased resistance - β1 effect should increases HR - Increased MAP triggers vagal-mediated decrease in HR - β2 effect on blood vessels not observed as α1 receptors predominate - Sympathoinhibition requires CNS activation, when given peripherally poor CNS penetration due to polarity also short half life/rapid metabolization E: Moderate dose - α1 vasoconstriction + β2 vasodilation almost equal = stable MAP - β1 effect increases HR - β2 vasodilation reduces resistance NE: - α1 vasoconstriction + β1 cardiac effects increase MAP - Baroreflex decreases HR - α1 vasoconstriction increases resistance Isoproterenol:- β2 vasodilation outweighs β1 cardiac effects to reduce MAP - β1 increases HR - β2 vasodilation reduces resistance Therapeutic Uses of Adrenergic Agonists • Nasal decongestants (a1; phenylephrine: counters dilation and engorgement of nasal mucosa blood vessels) • Cardiovascular - Extend local anesthetic action (a1; epinephrine: vasoconstriction reduces drug absorption) - Resuscitation after cardiac arrest (mainly a1, b1; epinephrine) - Antidote to hypotensive agent overdose (a1: vasoconstriction) - Maintaining blood pressure in spinal damage or anesthesia (a1: vasoconstriction, usually in combination with fluids) - Restoring blood pressure in cardiogenic shock (DA, a1) - Treatment of hypertension (a2; clonidine, not a first-line therapy) • Ophthamology - Mydriasis (a1 dilation: epi, phenylepinephrine) - Glaucoma (a2, b1 reduce fluid generation, a2 increase fluid outflow) • Allergic - Asthma (b2) mediated bronchial smooth muscle relaxation e.g. albuterol - Anaphylactic shock (a1, b1, b2) β2 relaxes airway smooth muscle and inhibits mast cell release of anaphylaxis mediators α1 maintains MAP • Other uses - Obstetrics: Delay premature labor (b2 relaxation of uterine smooth muscle) - Treatment of opioid withdrawal (a2) - TreatmentofAttentionDeficitDisorder(amphetamine, methylphenidate) Anaphylactic shock Anaphylaxis, a life-threatening allergic reaction caused by severe hypersensitivity to insect venoms (e.g., bee), certain foods (e.g., peanuts), and certain drugs (especially penicillin). Acute Tx - Epinephrine as activates α & β receptors α1 receptor vasoconstriction increases blood pressure and suppresses glottal edema β1 receptors increases cardiac output, thereby helping elevate blood pressure β2 receptors counteract bronchoconstriction Toxicity & Side Effects of Adrenergic Agonists • Vasoconstriction,ischemia(a1) • Hypertensive reactions, can cause cerebral hemorrhage (a1) • Reboundnasalcongestion(a1) • Withdrawalsyndrome(a2agonists) • Tachycardia(b1) • Myocardialischemia(b1) • Cardiacventriculararrhythmias(b1) • Increased risk of asthma exacerbation with extended use of long-acting b-agonists (b2) • Hyperglycemia (Liver + skeletal b2 activation converts glycogen to glucose) • CNSstimulation(mechanismunknown) Indirect-acting Sympathomimetics : increase availability of endogenous adrenergic transmitters: Octopamine, Amphetamine, Methylphenidate, Cocaine. Indirectly acting adrenergic agonists Tyramine, ephedrine, amphetamine (increase NE release) Tyramine (increase NE release) Present in food e.g. cheese, red wine Degraded by MAO (monoanimine oxidase) - when MAO is inhibited can trigger hypertensive crisis by release of NE from nerve terminals LONG TERM Tyramine converted to octopamine and stored in synaptic vesicles replacing NE. Octopamine is released but has little action at adrenergic receptors. Long term MAO therapy can impair function of sympathetic nervous system Indirectly acting adrenergic agonists Tyramine, ephedrine, amphetamine (increase NE release) • ADHD medications e.g. dextroamphetamine, methylphenidate - Evoke NE and DA synaptic release following oral administration - Also directly stimulate α + β1 • Ephedrine - Releases NE and directly activates α + β receptors, present in many "nutritional supplements" - FDA restricted use due to adverse effects Pseudoephedrine - widely used over counter decongestant, similar to ephedrine Indirectly acting adrenergic agonists Tricyclic antidepressants, Cocaine (prevent NE and DA reuptake) both centrally active Direct neuronal blockers Reserpine - rarely used - Depletes NE stores by inhibiting vesicular monoamine transport (VMAT) within synapse. NE not transported into pre-synaptic vesicle for release, NE metabolized by intra-neuronal MAO Alpha Adrenergic Antagonists a1 a2 phentolamine a1 a2 irreversible phenoxybezamine a1 selective prazosin a2 selectibve yohimbine Therapeutic Uses of a-Antagonists • Treatment of hypertension • Treatment of pheochromocytoma (b-blockers may also be used, but only after blocking a1-receptors) • Treatment of Raynaud's Disease (reduce digital vasospasm) • Treatment of heart failure (reduce vascular resistance) • Treatment of benign prostatic hyperplasia (BPH) - decreases bladder smooth muscle tone • Antidote to a-agonist vasoconstriction agonists • Postural hypotension - due to inhibition of α-mediated vasoconstriction - Reflex tachycardia - Myocardial ischemia (increased O2 demand from reflex tachycardia) - Salt & water retention (reflex β1 stimulation of renal RAS system) - Peripheral edema • GI stimulation (abdominal pain, nausea) • Inhibition of ejaculation Beta Adrenergic Antagonists b1 b2 :( proranol b1 selective :( metorpolol b1 b2 a1 carvedilol b1 and b2 pinodolol b1 short esmolol b1 b2 a1 labetalol b b b 1& 2 - propranalol 1 - Atenolol • Treatment of cardiac arrhythmias • Reducing mortality after myocardial infarction • Shock - maintains cardiac output and tissue perfusion • Treatment of heart failure, increases cardiac output (carvedilol FDA approved) • Treatment of hypertension (reduce cardiac output, inhibit renin production) • Treatment of angina (to control O2 demand) • Treatment of hyperthyroidism (propranolol) • Reducing anxiety ("stage fright") • Migraine prophylaxis • Treatment of open-angle glaucoma Protective Effect of b-Blockers after MI Protective effect of carvedilol in heart failure Toxicity & Side Effects of b-antagonists • Bronchoconstriction • Bradycardia • Withdrawal:exacerbationofangina,riskofsudden death • Fatigue • Coldextremities • Potentiation of epinephrine vasoconstriction • Precipitation of congestive heart failure (via inhibition of adrenergic compensation) • Possible predisposition toward new-onset diabetes
Thermal Injury
[23, 24] Thermal Burns are caused mainly by fire or scalding (the latter especially in children). Their clinical significance is determined by: the depth of the burn, the percent of body surface involved, the presence of internal injuries from inhalation of hot and toxic fumes, and the promptness and efficacy of therapy. Thermal burns are classified based on their depth. A superficial burn is limited to the epidermis, appears red and dry, and is painful. A partial- thickness burn destroys the epidermis as well as part of the dermis, appears red and moist with blisters, and is painful. A full-thickness burn destroys both the epidermis and the dermis layers, and is anesthetic (not painful, because the nerve endings in the skin are destroyed). Full thickness burns are not capable of regeneration, and pose a high risk of infection. [25] Hyperthermia is a consequence of prolonged exposure to high ambient temperature, and includes three conditions: 1) Heat cramps, which occur as a result of loss of electrolytes via sweating. 2) Heat Exhaustion, the most common of the three, manifests as prostration (extreme physical weakness) and a brief period of collapse (due to hypovolemia caused by dehydration). However, the affected individual soon recovers if properly rehydrated. 3) Heat stroke, which manifests as cessation of sweating due to failure of the thermoregulatory mechanisms with prolonged core temperature higher than 40oC (104oF). It is the most serious of the three hyperthermia types, and occurs under high temperature / high humidity conditions, especially in the elderly and in individuals under physical stress, such as athletes. Heat stroke leads to peripheral vasodilation and, if not promptly treated with cooling methods to reduce the high core temperature, results in reduced blood flow to the brain and heart, leading to confusion, coma, and eventually death Hypothermia is a consequence of prolonged exposure to low ambient temperature, which is often seen in homeless individuals, and can be systemic or local. Systemic hypothermia refers to a drop in core temperature, and can be mild, moderate, or severe, depending on the core temperature. Mild hypothermia [32-35oC (90-95oF) core temperature] is characterized by hyperventilation (fast breathing), lethargy, and vigorous shivering to generate heat. Moderate hypothermia [28-32oC (82-90oF) core temperature] is characterized by hypoventilation (slow shallow breathing), confusion, and loss of coordination. And severe hypothermia [<28oC (<82oF) core temperature] causes unconsciousness, slow or no breathing, and low or no pulse. Local hypothermia is restricted to that part of the body that has been under prolonged exposure to low ambient temperature, such frostbite of fingers, or trench foot, a term coined during World War I, when soldiers' boots were soaked in cold water while staying for long periods of time in waterlogged trenches. Local hypothermia is accompanied by suppression of vital metabolism in the affected body part, crystallization of intra- and extracellular water, increased permeability of vessels and, eventually, ischemia, hypoxia, and infarction (death of the tissue) - a condition called gangrene, which necessitates amputation.
mechanism for lead poisoning
indoor air pollutant - binds to sulfhydryl groups in proteins and blocks Ca++ metabolism - results in hematologic, skeletal, neuro, GI, renal effects e.g. radiodense led lines in epiphyses from poor remodeling of cartilage and bone children > adults (50% vs <15% absorption)
steps in laboratory analysis
- pre-analytic phase: before specicem is either received in the lab or being tested - analytic phase: specimen is being tested and a result is generated - post-analytic phase: generated result is seen by clinician who then uses result to make decision
B. Biotransformation*
1. Biotransformation refers to the elimination of a drug by chemical modification of the molecule. This process is rarely a spontaneous event and usually one that is an enzymatically catalyzed reaction. A drug may be biotransformed by reactions at several sites on the molecule. 2. The product(s) may have greater, lesser or qualitatively different pharmacologic activity from the parent compound. A prodrug is inactive and is biotransformed to a therapeutic agent. Highly reactive products such as quinones or epoxides may cause tissue necrosis or DNA damage. Examples are: 3. The reaction rate is dependent on chemical structure and obeys Michaelis Menten kinetics; the rate is usually first-order at therapeutic drug concentrations (and therefore proportional to the drug concentration); it may be zero-order (i.e. constant), if the drug concentration substantially exceeds the Km of the enzyme of biotransformation. 4. Enzymatic activity is generally highest in the liver. Enzymes in target organs, e.g., neurons, kidney, lung etc., may be responsible for conversion of drug to therapeutic or toxic metabolites. Enzymes in intestinal bacteria carry out reductive and hydrolytic reactions, some of which may facilitate enterohepatic circulation of drug conjugates excreted in bile. 5. Sources of individual variation in clearance by biotransformation a. Exposure: Drugs, herbal medicines (e.g., St. John's wort), dietary constituents (e.g. grapefruit juice), and chemicals in the environment (xenobiotics, e.g. cigarette smoke) may be substrates, inhibitors and inducers of enzymes of biotransformation and may interact at the same enzymes; this phenomenon is the basis for many clinically significant drug-drug, drug-diet and drug-xenobiotic interactions. b. Genetics: Level of enzyme activity shows greater concordance among identical than fraternal twins; many enzymes of biotransformation exhibit genetic polymorphisms of clinical significance in which case drug substrate clearances are distributed bimodally or trimodally depending upon the frequency of gene mutation in the population of patients; the frequency of polymorphisms tends to vary with ethnicity. Important examples include: pseudocholinesterase: hydrolyzes the neuromuscular blocker succinylcholine; rare gene mutation results in markedly slower clearance, prolonged elimination half-life, and much longer duration of neuromuscular blockade N-acetyltransferase: acetylates the antitubercular agent isoniazid; common mutation so that about 50% of patients are slow acetylators, which increases risk of certain side effects CYP2D6: hydroxylates many drugs of therapeutic significance c. Age: Activity of some drug-metabolizing enzymes, such as glucuronyl transferase, is low in the neonate. d. Disease: Reduction in hepatic blood flow (e.g., in congestive heart failure) may decrease hepatic clearance of drugs that are readily biotransformed; hepatic disease (especially chronic) may reduce hepatic clearance by biotransformation 6. Major pathways of biotransformation a. Phase I: Often first step in biotransformation with formation of product susceptible to phase II conjugative reaction; products may have therapeutic or toxic activities 1.) Types of reactions Oxidations: N- and O- dealkylations, alphatic and aromatic hydroxylations, N-and S- oxidation, deamination, desulfuration Reductions: azo and nitro reduction Hydrolyses: deesterification and deamination 2.) Primary oxidative enzymes, the cytochrome P450s Enzymes in membranes of smooth endoplasmic reticulum called mixed-function oxidases or monooxygenases contain cytochrome P450; this oxidative reaction requires NADPH, O2 and a reducing agent (cytochrome P450 reductase, a flavoprotein) and entails oxidation-reduction of Fe in the heme group. Highest activity in liver, activity in intestinal mucosa also affects oral bioavailability for some drugs. Multiplicity of enzymes (more than 12 CYP gene families in humans) with overlapping substrate specificity; endogenous substrates include steroids, prostaglandins; most important drug-metabolizing isozymes are CYP3A4 and CYP2D6. Isozymes differ in induction of their gene expression, e.g., barbiturates induce some (2C9, 3A4), polycyclic aromatic hydrocarbons (dioxins, cigarette smoke) induce others (CYP1A); inducers bind to cytosolic receptors, such as arylhydrocarbon (AhR) and pregnane X (PXR) receptors that then combine with promotor site for the CYP450. Isozymes differ with respect to inhibitors, e.g., component of grapefruit juice is selective inhibitor of CYP3A4. b. Phase II: Coupling of drug or its oxidized metabolite to endogenous conjugating agent derived from carbohydrate, protein or sulfur sources; product ALWAYS greater in molecular weight, products generally more water-soluble and more readily excreted in urine or bile; products generally have less therapeutic activity than parent drug.
N-methylnaltrexone
Derivative of naltrexone Quaternary amine - can't cross BBB, but can help w/ effect outside of brain (i.e. Constipation, delayed gastric emptying, urinary retention) - opioid antagonist for outside CNS only (still get analgesia, but this helps w/ side effects :) )
How do opioids cause hives?
NOT an allergic reaction Just competitive displacement of histamine (opioid-induced histamine release)
Pharmacokinetic antagonism
Occurs when the antagonist accelerates the metabolism/elimination of the agonist E.g. Drug that inc. liver enzymes to metabolize/biotransform agonist to inactive form faster
what does a fibrinous exudate look like?
bread & butter
% bound to protein in plasma for: - warfarin - codeine
warfarin = 99% codeine = 7%
How does St. John's Wort interact with a lot of drugs
- inc. cyt P450 - inc. metabolism of drug
what determines where stored material is distributed?
- site where most of the material to be degraded is found (e.g. gangliosides in brain) - location where most degradation normally occurs (e.g. RES [macrophages] in lymph nodes, spleen, and liver)
post-analytic variables for lab testing
- takes time for generated result to transfer from lab info system (LIS) to EMR - time it takes for ordering clinican to see result
Physicians, Industry Payments for Food and Beverages, and Drug Prescribing
In 2015, the pharmaceutical industry and other health care companies reported to the Centers for Medicare & Medicaid Services through the Open Payments pro- gram a total of $235 million in food and beverage pay- ments to physicians, accounting for approximately 12% of general payments.1 General payments include royal- ties and licenses, consulting, services other than con- sulting, travel and lodging, and serving as faculty in ac- credited and unaccredited education programs. There are about 850 000 active physicians in the United States. Of 616 567 physicians in the United States with any type of general payment in 2015, 589 042 (95.5%) received food and beverage payments, with a total mean value per physician of $400 and a median value of $138.1 Although the median value of each food and beverage payment is modest, these are by far the most frequent types of gifts and payments that physicians receive from industry, apparently now supplanting the branded black bags, pens, mugs, and other tchotchkes of yore.2 Individual physicians may note that even though they attended an industry-sponsored educational or pro- motional event where food and beverages were pro- vided, they did not eat or drink anything; nonetheless, ceived a single meal (mean value of $12 to $18 per meal) promoting the drug of interest had higher rates of prescrib- ing rosuvastatin over other statins, nebivolol over other β-blockers, olmesartan over other angiotensin-converting enzyme inhibitors and angiotensin-receptor blockers, and desvenlafaxine over other selective serotonin and serotonin-norepinephrine reuptake inhibitors. With receipt of additional meals and of meals costing more than $20, there were higher relative prescribing rates. For example, in unadjusted analyses, "[p]hysicians receiving meals re- lated to target drugs on 4 or more days prescribed rosu- vastatin at 1.8 times the rate (15.2% vs 8.3%), nebivolol at 5.4 times the rate (16.7% vs 3.1%), olmesartan at 4.5 times the rate (6.3% vs 1.4%), and desvenlafaxine at 3.4 times the rate (1.7% vs 0.5%) of physicians receiving no target meals (all comparisons, P < .001)."7 The drugs were cho- sen for study because they were the most-prescribed brand-name drug in each of their drug categories in Medi- care Part D in 2013, with what the authors characterized as "limited, mixed, or contrary evidence about the supe- riority of these 4 drugs over generic alternatives."7 A separate analysis of Open Payments data by Ornstein and colleagues8 found that "[d]octors who got money from device and drug makers— even just a meal—prescribed a higher percentage of brand-name drugs over- all than doctors who didn't,"8 and "the more money they receive, on average, themorebrand-namemedicationstheyprescribe."8The mean prescribing rates of brand-name drugs among fam- ily medicine physicians, internists, cardiologists, psy- chiatrists, and ophthalmologists were highest among those who received other types of payments (such as speaking payments, either alone or in combination with meals) than those whose only industry payments were for meals. Nonetheless, physicians who received only meals still had significantly higher rates of prescribing brand-name drugs than physicians who received no in- dustry payments.9 A limitation of both studies is that their findings rep- resent associations between industry payments for food and beverages and physician prescribing behavior, not cause-and-effect relationships. Some of those attend- ing industry events may already prefer a company's drug and are seeking additional information from the com- pany that markets it. Some physicians make a point of avoiding promotional events. Those in attendance are a skewed sample of prescribers. Focusing on such limitations, however, begs a broader question: is there any need to prove a causal relationship between industry payments to physicians and the prescrib- ing of brand-name medications? First, industry-sponsored meals and other outright gifts may be legal, but are there Opinion Corresponding Author: Robert Steinbrook, MD, Department of Internal Medicine, Yale School of Medicine, 333 Cedar St, I-456 SHM, PO Box 208008, New Haven, CT 06520 (robert [email protected]). jama.com anyonewhoregisteredattheeventisconsideredtohave received a payment, with the per-physician amount de- termined by dividing the total that the sponsor spent on food and beverages by the number of attendees. Providing hundreds of millions of dollars of indus- try payments to physicians for food and beverages each year is not a charitable act; like other investor-owned businesses, pharmaceutical companies seek to maxi- mize their profits, and they provide meals with the ex- pectations of good returns.3 Without the provision of food and beverages, it is likely that fewer physicians would attend industry events and listen to presenta- tions by academic experts, pharmaceutical company em- ployees, or other speakers paid for by industry. For years, the evidence has suggested that even small gifts can influence physicians' behavior, create a mindset of entitlement, and help to promote allegiance to compa- nies and their products.2,4,5 Recently, with the availability of Open Payments data6 and research made possible by these data, the evidence has become stronger. Using Open Payments data, a 2016 study found that receipt of industry-sponsored meals, even just a single meal, was associated with an increase in the rate of pre- scribing the brand-name drug that was being promoted.7 DeJong and colleagues7 found that physicians who re- Physicians have to ask why they are accepting this industry largesse. (Reprinted) JAMA May 2, 2017 Volume 317, Number 17 1753 Copyright 2017 American Medical Association. All rights reserved. Downloaded From: http://jamanetwork.com/pdfaccess.ashx?url=/data/journals/jama/936200/ by a Boston University User on 05/06/2017 Opinion Viewpoint any reasons for physicians to either expect or accept them? Second, in this situation, perceptions of conflict of interest are more important than discussing whether there is an actual conflict of interest, and the clear perception is that companies are using the provision of food and beverages to increase attendance at promotional events and to drive sales. Third, part of the privilege of caring for patients is to be mindful of their finances as well as their health. In 2015, spending on prescrip- tion drugs alone in the United States was approximately $1000 per per- son. For situations in which less expensive and similarly effective alter- native medications are available, physicians should be prescribing these alternatives, not more expensive choices. Fourth, even when patients have prescription drug insurance or may be eligible for rebates or other discounts, unwarranted prescribing of more expensive medications shifts costs to insurers, states, the federal government, and society as a whole and makes needed health care less affordable for everyone. There are complex issues and trade-offs with regard to conflict of interest in medicine. Gifts, which in 2017 are primarily industry- sponsored meals, however, are not one of these. The American Medi- cal Association's Code of Medical Ethics is clear that "[g]ifts to phy- sicians from industry create conditions that carry the risk of subtly biasing—or being perceived to bias—professional judgment in the care of patients."10 Physicians have to ask why they are accepting this industry lar- gesse. Each year, $235 million would pay for considerable needed care for patients who cannot afford it or essential clinical research. Instead of dining on meals from industry, physicians should be ad- vocating for drug and device manufacturers to spend less on pro- moting their products and more on independent bona fide re- search on safety, effectiveness, and affordability. Patients and the health care system deserve no less.
how do phagocytic cells kill bacteria
1. extracellular traps 2. intracellular killing ---> phagocytosis ---> phagolysosome ---> proteases ---> reactive oxygen and nitrogen
Would either norepinephrine or Alpha be preferable to the other as a vasopressor (or vasoconstrictor) for clinical use? Why?
Based only on the data available, norepinephrine may be preferable to alpha as a vasoconstrictor because its efficacy is greater. However, this depends upon the clinical goals, as a partial agonist may sometimes offer adequate efficacy with reduced risk of adverse effects at high doses.
microbiology lab tests
ID of different microorganisms through culture, stains, chemical rxns, molecular techniques, and proteomics also tests such as antibiotic susceptibility, viral load, genotype testing
Atropine Scopolamine scopalamine crossCs BBB and blocks memory???? Antihistamines
Muscarinic Antagonist Belladonna alkaloids, deadly nightshade treat with AChE inhibitors (physostigmine) to increase the amount of Ach Loss of parasympathetic tone: tachycardia, vasodilation, bronchodilation, mydriasis, decreased GI motility, decreased salivation, tears, sweating
Based on the receptor selectivity indicated in the above table, what adrenergic prototypes most resemble A, B, and C, respectively?
Of the adrenergic prototypes provided in your lecture notes, metoprolol is most like A, prasozin and phentolamine are most like B, and carvedilol is most like C.
PGE2
Prostaglandin Metabolite of arachidonic acid via COX pathway fever, increased pain and edema in response to histamine, bradykinen
tricyclic antidepressants
centrally active inhibit catecholamine and serotonin reuptake also have antimuscarinic side effects & high doses (+symp)
rheumatoid arthritis chronic inflammation features a collection of which cells?
macrophages and lymphocytes complex immune cycling leads to endless cycle
Hisamine vasoactive amines Serotonin
mast cells, platelets stimulated by antibodies, physical injury, neuropeptides like substance P, C3a, C5b mast cells, platelets
mixed tumor
may have neoplastic components of epithelial and mesenchymal (stromal) elements benign
distribution of receptor types in different tissues
skin & mucosa: a splanchnic & renal: a, B, D skeletal muscle: a, B
Aspirin structure/charge
weak acid (pka = 3.5) loses H+ at physiologic pH to become negatively charged pka 3.5 < pH 7.4 --> negative charge @ 7.4
when do you get tissue injury?
when there's more acute inflammation than is necessary, due to: - release of ROS - release of proteases (i.e. lysozyme into tissue) - inappropriate coagulation
1. Describe the pathophysiology of the following adaptive cellular responses - hyperplasia, hypertrophy, atrophy and metaplasia
ADAPTATION, INJURY AND CELL DEATH CELL RESPONSES TO STRESS AND INJURY The tissues of the body and the cells that comprise them need to maintain a steady state or homeostasis. When they are exposed to extra demands or stress they are designed by nature to adapt in order to preserve the health or wellbeing 14-1 of the whole body. Such demands may be physiologic, as when the cells and tissues of the uterus adapt to a pregnancy or when the bone marrow responds to a lower oxygen tension of the blood as one ascends to high altitude. These cell and tissue adaptations are instigated by molecules such as growth factors, hormones or cytokines that interact with sensors or receptors at the cell surfaces causing them to activate signaling pathways inside the cell. In this way signals that can modify transcription of proteins reach the nucleus. The resulting adaptive responses may range from inducing the cells to undergo division to altering the production of structural and functional proteins. Similarly, if cells are exposed to excessive or pathologic stress, such as insufficient oxygen that depletes the ATP necessary for vital survival functions, they will immediately attempt to adapt (- in this case by increasing anaerobic glycolysis). If, however, the adaptation does not restore a steady-state, the cell will show signs of injury. These signs include an altered appearance and impaired function and they indicate loss of homeostasis and a disease state. If the injury is not too severe, it can be reversed when the stress or injurious agent is removed. If severe injury persists, however, the cell may undergo irreversible changes and die. CELL AND TISSUE ADAPTATIONS Hyperplasia Hyperplasia is an increase in the number of cells resulting in increased volume of the organ or tissue. It can only be initiated where there is a cell population capable of division and proliferation. It can be physiologic or pathologic. Examples of physiologic hyperplasia: The lactating breast - the increase in number and size of the breast lobules in lactation is due to stimulation by estrogen and the pituitary hormone prolactin (hormonal hyperplasia). Post-hepatectomy regeneration: restoration of the volume of the liver following partial hepatectomy for injury or organ donation (compensatory hypertrophy). The stimulus for this regeneration is growth factor production by the residual hepatocytes. Examples of pathologic hyperplasia: Follicular Hyperplasia of Lymph Nodes, for example in the neck in response to an oral infection or dental abscess. Exposure to the antigens of the infectious agent leads to B-cell proliferation in the follicles of the regional lymph nodes. Benign prostatic hyperplasia, a common disorder in men over 50 which is caused by the testosterone metabolite dihydrotestosterone inducing nodular enlargement of the gland. The enlarging nodules of hyperplastic glands and stroma impinge on the prostatic urethra and cause urinary retention. Squamous hyperplasia: in response to chronic irritation, such as an ill-fitting denture, for example, an irritated area of squamous mucosa may become thickened to compensate for repeated loss of surface epithelial cells. The molecular mediator of this response is the growth factor TGF- A notable feature of both physiologic and pathologic hyperplasia is that when the stimulus that induces it is removed, proliferation ceases. Failure to respond in this way would suggest that the process has become autonomous and thus neoplastic. A transformation from pathologic hyperplasia to neoplasia can sometimes occur. A final point is that hyperplasia often occurs in association with hypertrophy so that adaptive responses such as those in the uterus and breasts in pregnancy and lactation can be cited as examples of both hyperplasia and hypertrophy. Hypertrophy Hypertrophy is an increase in the size of cells leading to increased tissue volume. The increased size results from increased synthesis of cellular components. Hypertrophy, in contrast to hyperplasia, does not require a cell population capable of cell division but can occur in fully mature non-dividing cells. It also can be physiologic or pathologic and is usually caused by increased functional demand. Examples of physiologic hypertrophy. Hypertrophy of hepatocytes due to increased endoplasmic reticulum in response to the functional demand for metabolism of ingested drugs such as Phenobarbital. Muscle hypertrophy induced by "pumping iron". The increased size of the individual skeletal muscle fibers is due to increased numbers of actin and myosin fibers and cellular organelles necessary to support increased function, most notably mitochondria. The stimulus is mechanical stretch that cell membrane transducers convert to the appropriate protein transcription signals. The process is controlled by multiple regulatory factors. One such is a recently described inhibitor of muscle growth, myostatin, a molecule related to the TGF- family of growth factors. It is interesting that children born with a rare inherited deficiency of myostatin are found to have hypertrophic muscles and Herculean strength from an early age without any muscle training. Examples of pathologic hypertrophy. The prototypical example of pathologic hypertrophy is cardiac muscle hypertrophy in response to abnormally increased peripheral vascular resistance, i.e. hypertension. The mechanism of cardiac hypertrophy involves many signal transduction pathways that lead not only to increased synthesis of functional proteins, but also to the synthesis of growth factors and agents that affect peripheral vessel tone and caliber and even kidney function by the action of newly synthesized ANF (atrial natriuretic factor). The major known signaling pathways and their functional effects are shown in Robbins & Cotran 9th, Fig 2-4. Mechanical sensors appear to be the major triggers for physiologic hypertrophy, and agonists such as a-adrenergic hormones and angiotensin and growth factors may be more important in pathologic states. Atrophy Atrophy describes shrinkage of a tissue due to loss of cell substance and or cell number. It can be physiologic or pathologic. An imbalance between protein 14-3 degradation and synthesis drives the process. A pathway responsible for accelerated proteolyis in atrophy is referred to as the ubiquitin-proteasome pathway. Targeted proteins are conjugated with ubiquitin which chaperones the protein into a cytoplasmic organelle called a proteasome where it is degraded. Atrophic cells often exhibit numerous lysosomes that contain fragments of cell components such as mitochondria or endoplasmic reticulum. Such lysosomes are called autophagic vacuoles. Increased protein and structural degradation occurs within the lysosomes due to the activation of hydrolytic enzymes and other proteases. Atrophic cells ultimately accumulate numerous shrunken lysosomes that contain only lipofuschin, the residue of hydrolytic enzyme digestion. These structures are called, appropriately, residual bodies. They confer a brown color on atrophic organs; for example the atrophic heart in patients who die with wasting illnesses or cachecia has been described as showing brown atrophy attributable to this phenomenon. Examples of atrophy. Atrophy of disuse. Examples include the wasting of muscles in a limb immobilized by a plaster cast. Another example is thinning of bones or osteoporosis occurring in astronauts that is induced by prolonged weightlessness during space flight. Denervation atrophy. Interruption of the peripheral nerve supply to muscle due to trauma or disease results in rapid atrophy and loss of denervated muscle fibers. Ischemia (diminished blood supply). A limb affected by chronic ischemia, due, for example, to atherosclerosis is apt to show signs of atrophy that include thinning of the skin epidermis and hair loss and marked reduction in muscle mass and strength. Inadequate nutrition can lead to atrophy of muscle and internal organs. This is referred to as cachecia. It is also seen in patients with chronic illnesses and cancer. In the latter it is sometimes attributed to overproduction of a cytokine called Tumor-necrosis factor that induces appetite suppression and accelerates atrophy. Loss of hormonal stimulation. Loss of estrogen in post menopausal females results in physiologic atrophy of the endometrium, and the cervical and vaginal epithelium. Senile atrophy. Advanced aging may be associated with atrophy. This contributes to the hollow-cheeks and loose dentures commonly observed in the very elderly. A more thought-provoking manifestation of senility, perhaps, is the occurrence of gradual atrophy of the cerebral cortex. Metaplasia Metaplasia is a reversible change in which one adult cell type (epithelial or mesenchymal) is replaced by another adult cell type. It results from the reprogramming of tissue stem cells and is brought about by the actions of cytokines, growth factors and extracellular matrix components. For example, the cytokines, Bone Morphogenetic Protein (BMP) and TGF- can induce undifferentiated mesenchymal cells to differentiate into bone or cartilage. The "survival" benefit of metaplasia is thought to be greater resistance to a specific 14-4 stress or adverse environment afflicting the tissue. The most common epithelial metaplasia is conversion of a columnar to a squamous phenotype in response to chronic irritation. The prime example is squamous metaplasia of the lower respiratory tract induced by the chronic irritation of cigarette smoking. Another very prevalent example is Barrett's esophagus. This refers to replacement of, in this case, the more susceptible squamous mucosa of the lower esophagus by a more acid-resistant gastric or intestinal columnar mucosa in response to persistent acid reflux from the stomach.
DRx Foundations Clinical Correlation
-poorly controlled with inhaled corticosteroids and beta-agonists. Also with recurrent sinus infections and episodic joint aches -In acute bacterial pneumonia, what cell type is most commonly seen infiltrating the alveolar spaces: neutrophils -WBC HGB/HCT Plt -NA/K CL/HCO3 BUN/Cr Gluy -Eosinophil w large granules fights against parasites -Eosinophil makes major basic protein -Pancreatic acinar cells make elastase -TNF alpha is made mainly by macrophages + more -Myeloperoxidase (MPO) is made by neutrophil granulocytes -IL 2 is made mainly by CD4 T Cells -25% Eosinophilia (usually 1%): NNAACP: Neoplasm, allergic diseases, asthma, addisons disease, collagen vascular disease, parasites, (worms, wheezes, weird diseases). -Asthma, sinus, pulm infil, palpable purpura, eosinophilia, renal insufficiency. -Eosinophilic Granulomatosis with Polyangiitis: Asthma, sinusitis, palpable purport, peripheral neuropathy, eosinophilia, granulomatous vasculitis, P-ANCA positive (anti-neutcytoab) - Eosinophilic Granulomatosis with Polyangiitis allergic granulomatosis, angitits, inflammation of small/medium arteries, starts with 95% asthma/rhinitis, then pulmonary infiltrates/eosinophilia (+1500 EOS), and vasculitis of other organs. Treat with oral prednisone until low inflammation taper over 12-18 months, corticosteroid potential for life, cyclophosphamide anti-neoplastic agent with immunosuppressive properties,. -Mechanism: interact w/ cytosolic hGR alpha, translocate into nucleus, bind GRE to promote gene expression, interact with GR with transcriptional regulators (inhibit NF-kb gene expression) -Glucocorticoids are ant-inflammatory by lowering conversion of arachidonic acid to prostaglandins/leukotrienes, decrease extravasation of leukocytes in injury site, lower fibrosis with reduced production of collagen. -Glucocorticoid long term side affects: osteoporosis with fractures, muscle wasting, hypertension, hyperglycemia, candida infections, weight gain, infection, impaired wound healing, cataracts, behavioral disturbances, slowed growth in kids, -Mustard grads are blinding, biting Cl----N/S----Cl with do Bis(chloroethyl)amine alkylation of N7 of guanine in DNA - Alkylating agents are primarily DNA-directed: Mechlorethamine, Melphelan (multiple myeloma, ovarian & breast cancer), chlorambucil (chronic lymphocytic leukemia, lymphoma), Cyclophosphamide, and Ifosfamide (testicular cancer, sarcomas). Monoalkylated, interstrand crosslink, intrastrand crosslink. Cyclophosphamide: must be activated to 4-hydroxy-cyclophosphamide by liver cytochrome P450. Used in leukemia/lymphoma, breast, ovarian cancer. Used in rheumatologic disorders to suppress immune system. Side effects: nausea and vomiting, bone marrow suppression; sterility; hemorrhagic cystitis Pretreatment: 100% death; now: 70% 5-year survival.
DMARDs
Disease-modifying anti-rheumatoid drugs E.g. Glucocorticoid
Integ
Clinical Correlation DRx Foundations Robert C. Lowe, M.D. August 1, 2017 • 27 y.o. male with a history of IVDU presents with three days of R arm pain and redness. • He reports chills, but has not taken his temperature at home. • He uses 5-10 bags of heroin per day, shooting up in his arms and legs. • He has no other past medical history Physical exam • T 101.0 P 95 BP 120/70 RR 14 O2 sat 99% • HEENT normal • Chest CTA • Card RRR S1+S2 with no M/R/G • Abd soft, NT/ND, no HSM • Ext: no c/c/e • Skin... Cellulitis • Skin infection involving dermis and subcutaneous tissue • Erythema, edema, pain, warmth • May be associated with abscess • Commonly due to Strep and Staph in normal hosts • Diabetics = much broader range of bacteria www.goldbamboo.com Levels of SSTI Green, et al. Chest 1996; 110 219-29 Levels of SSTI Green, et al. Chest 1996; 110 219-29 All that is inflamed is not infected CCJM 2012 Aug;79(8):547-552. Venous stasis dermatitis Necrotizing Fasciitis • Infection of deep fascia - poorly vascularized • Type 1 - anaerobes, Gram negatives • Type 2 - Group A strep (+/- Staph) • Severe pain, bullae, purple color, anesthesia of surface • Surgical debridement is essential Levels of SSTI Green, et al. Chest 1996; 110 219-29 Contrasting Pathologic Findings Cellulitis Necrotizing Fasciitis • Non-necrotizing • Acute inflammation- PMNs • Architecture largely intact • Dermis, upper subcutaneous tissue involved • Necrosis of fascia and fat • Patchy acute inflammation • Extensive destruction • Can see bacteria in tissue sfghed.ucsf.edu/Education/ClinicImages/infections.htm Labs 16.5 250 138 104 24 3.6 24 0.9 110 40.1 Poly 90% Lymph 8% Monos 1% Eos 1% Plasma Protein Vessel Lumen PMN Endothelial cell Damage Damaged endothelial cell Tissue Leakage of Plasma Proteins AND Extravasation of neutrophils 19 Steps in Acute Inflammation 1. Blood vessel dilates to increase flow 2. Microvascular changes allow proteins and cells to leave the blood vessel 3. Emigration, accumulation and activation of leukocytes Which of the following receptors mediates the rolling of neutrophils along the endothelium? P-selectin Migration Across The Vessel Wall Which of the following is found in Gram positive bacteria, but NOT in Gram negative bacteria ? . Teichoic acid Bacterial Cell Walls Mycobacteria produce a thick mycolic acids-rich outer covering which functions as an exceptionally efficient barrier. Penicillin Methicillin blactam ring Vancomycin Spectrum: gram positive aerobes, including MRSA No gram negative activity, molecule too large to cross the outer membrane in gram negative organisms • Use: - Gram positive infections resistant to beta lactams - Gram positives infections in persons unable to tolerate beta lactams - Second line therapy for C. difficile colitis (oral) Vancomycin • Pharmacokinetics - Poor oral absorption, only use PO for C. difficile colitis - Good distribution (CSF poor) - Minimal metabolism, renal excretion - Monitor trough levels • AdverseEffects - Infusion related effects (slow rate of infusion) - Hematologic - Hypersensitivity - Ototoxicity/Nephrotoxicity rare
Reserpine
direct neuronal blocker depelets NE stores by inhibiting VMAT within synapse; NE isn't transported into pre-synaptic vesicle for release and NE is metabolized by MAO rarely used
reference range
created for every test using your patient demographics includes values within 2 SDs of the mean (95% of normal or non-diseased patients( can differ based on age, gender, time of year, time of day, etc.
hyperemia
dilated blood vessels to inc. flow; occurs w/ acute inflam response
cocaine, d-Amphetamine, and methylphenidate
indirect agonist/central stimulant (transporter inhibitor/releaser) d-amphetamine: releases NE and DA, also acts directly on a and B1; orally active, marked CNS effects (wakefulness, anorexia, euphoria, locomotor stimulation, stereotyped behavior) - high abuse potential - psychotomimetic w/ prolonged abuse - clinical use for ADHD methylphenidate: effects similar to d-amphetamine; primary clinical use for ADHD cocaine: *inhibits reuptake* of NE and DA; centrally active, with effects similar to amphetamine; high abuse potential, primarily illicit drug; can precipitate fatal CV and CNS events, sometimes even @ moderate doses
Cytoplasmic (Cell) Membrane
1. Locatedjustinsidethepeptidoglycanlayer. 2. Phospholipid bilayer similar to eukaryotic membranes, but does not contain sterols (except Mycoplasma species). 3. Functions: a. active transport of molecules into cell b. energy generation by oxidative phosphorylation c. synthesis of cell wall precursors d. secretion of enzymes and toxins e. signal transduction
dobutamine
B1 selective agonist actually has a complex mixture of actions, also including a1 agonism and antagonism, but B1 effect predominates
albuterol
B2 selective agonist B2 > B1
adrenergic drugs to treat anaphylactic shock
a1 rec. vasoconstriction to inc BP and suppress glottal edema B1 rec. inc CO, helping elevate BP B2 counteract bronchoconstriction
epinephrine
a1=a2; B1=B2 endogenous agonist released into bloodstream by adrenal medulla
NE
a1>a2 > B1 >> B2 endogenous sympathetic transmitter
information bias indication bias
information bias = due to measurement error or misclassification; differing assessment of outcome in case vs control group indication bias = drug given to those at higher risk of outcome, so appears drug causes outcome
initial concentration
C0 = dose / Vd
Opioid receptor structure
GPCR - G0 = Decreases AC! Dec. AC still results in stimulatory effects via disinhibition
TNM criteria
to stage tumor - Tumor - Nodes (lymph nodes) - Metastasis
a2 side effects
withdrawal syndrome - reversal of hemodynamic effects i.e. hypertension, tachycardia)
Opioid Receptor "agonist-antagonists"
Nalorphine, buprenorphine (Partial agonists, or agonist @ one kind of opioid rec, antag at another)
Natural, semisynthetic, and synthetic alkaloids
Natural: morphine, codeine Semisynthetic: heroin, hydromorphone (dilaudid) Synthetic: meperidine, methadone, fentanyl
principal mediators of chemotaxis, recruitment, and activation
- TNF - IL-1 - chemokines - C3a, C5a - LTB4 (leukotriene B4)
Treatment for eosinophilic granulomatosis with polyangiitis
- corticosteroids: oral prednisone until inflammation subsides, then taper over 12-18 months; many require low dose steroids for life - cyclophosphamide: an anti neoplasticism agent with immunosuppressive properties
58. A patient is recommended loratadine for allergic rhinitis. The patient should be advised that: Second generation H1 H1 receptor antagonists (- IP3/DAG) similar to diphenhydramine A. Care should be taken in driving because of an expected sedative effect. B. Use of NSAIDs will be safer, because gastric acid secretion will be inhibited. C. Dryness of the mouth may occur, due to inhibition of salivary secretion. D. Abnormal heart rhythm is likely to occur. E. *The recommended drug may be preferable to diphenhydramine, because the risk of side effects is lower. Lack of sedative or antimuscarinic effects. Several agents were found, after marketing, to cause a potentially fatal arrhythmia (a ventricular tachycardia referred to as torsades de pointes), because of block of certain potassium channels in the heart. The risk, which was rare, increased when these agents were taken with drugs that inhibited their biotransformation by CYP 3A4 (such as erythromycin). One of these, terfenadine (SELDANE) was withdrawn from the market and replaced by its active metabolite, fexofenadine, which is not cardiotoxic. 57. The anti-inflammatory effects of NSAIDs are: Attributed primarily to their COX 1 inhibitory effect. Attributed primarily to their ability to reduce synthesis of prostaglandins and leukotrienes. *Achieved in the case of aspirin with doses higher than those that affect bleeding time. Lower in maximum efficacy than observed with COX 2 selective agents. Associated with increased risk of colonic adenomas, when these drugs are used in prolonged therapy. NSAIDs reduce the inflammatory response to mechanical, chemical or immunological stimuli; the mechanism is believed to be primarily inhibition of COX-2. These drugs are useful in treating diseases such as acute rheumatic fever and rheumatoid arthritis, where they may cause symptomatic relief. However, there are limits to their efficacy and various toxicities, which have resulted in development of many drugs in this class, as well as the selective COX-2 inhibitors. The limits to their maximum anti-inflammatory effect and lack of efficacy on the underlying disease process has led to development and use of numerous alternative classes of agents, generally referred to as "disease-modifying antirheumatic drugs" (DMARDS). These include: a.) small, low molecular weight drugs, such as certain antimalarial agents (e.g., chloroquine), sulfasalazine (a prodrug of sulfapyridine coupled to 5-aminosalicylic acid), glucocorticoids, leflunomide, and 'antimetabolites' (e.g. methotrexate) and b.) large, high MW biologic agents (protein therapeutics), such as TNF inhibitors (the monoclonal antibody infliximab and the soluble TNF-receptor analogue etanercept, both of which bind TNF and prevent its interaction with its membrane receptor). Other immunosuppressive protein molecules are described at the end of this document.The anti-inflammatory activity of aspirin may explain the decreased risk of colon cancer in long-term users. 56. The effect of aspirin on bleeding time results from: Inhibition of prostacyclin synthesis by the vascular endothelium. Reversible inhibition of COX 2 in platelets. *Irreversible inhibition of thromboxane synthesis in platelets. COX 1 inhibition in platelets that is reversed in about 24 hours by synthesis of new enzyme in the existing platelet pool. COX 1 mediated inhibition of platelet formation in the bone marrow. Block in platelet cyclooxygenase synthesis of thromboxane A2, a potent stimulator of platelet ADP release and aggregation, prolongs bleeding time by inhibiting normal formation of a platelet plug and platelet-induced acceleration of plasma coagulation. The effect of aspirin is prolonged (due to irreversible platelet COX inhibition) and highly selective relative to other NSAIDs. The effect is not observed with acetaminophen. A single analgesic dose of aspirin doubles bleeding time for as long as 4 to 7 days (the life span of a platelet). Aspirin is contraindicated in patients with bleeding disorders, such as severe hemophilia, in patients prior to surgery, and in platelet donors (within 12 hours). Aspirin is recommended in low doses to decrease risk of thromboembolic disorders such as transient ischemic attacks and myocardial infarction. The role of aspirin in the prevention of cardiovascular disease will be discussed further in the Cardiovascular Module. 53. In a patient with severe rheumatoid arthritis who is not effectively treated with an NSAID, an appropriate alternative anti-inflammatory agent might be: A. Acetaminophen: Nonopioid analgesics B. * Infliximab: Large, High MW Biologic Agent: TNF inhibitors C. The oatp inhibitor probenecid: the multidrug resistance-associated proteins (MRP1-6, 190 kD) and organic anion transporters (oatp); organic anion substrates, probenecid sensitive. D. A tricyclic antidepressant: Tricyclicantidepressants:Centrallyactive.Inhibitcatecholamineand serotonin reuptake. Also have antimuscarinic side effects at high doses. E. A TNF∝ agonist NSAIDs reduce the inflammatory response to mechanical, chemical or immunological stimuli; the mechanism is believed to be primarily inhibition of COX-2. These drugs are useful in treating diseases such as acute rheumatic fever and rheumatoid arthritis, where they may cause symptomatic relief. However, there are limits to their efficacy and various toxicities, which have resulted in development of many drugs in this class, as well as the selective COX-2 inhibitors.. Many chronic inflammatory diseases are treated with inhibitors of inflammation. Some of these treatments are non-specific, such as glucocorticoids which decrease multiple aspects of the inflammatory response. Other treatments are relatively specific, such as the use of cytokine inhibitors. There are multiple TNF inhibitors approved by the Food and Drug Administration for the treatment of chronic inflammation. Some of these were discussed in the immunology course in the first year. However, many of the cytokines in chronic inflammation are essential components to keep infections under control. It is well recognized that blocking TNF to treat chronic inflammatory diseases significantly increases reactivation of tuberculosis. 52. An asthmatic child presents with a fever associated with a viral illness. An appropriate antipyretic and the rationale for the choice is: A. Ibuprofen, because it is not known to cause bronchospasm in asthmatic patients. B. Aspirin, because its antipyretic efficacy has a longer duration of action than other choices for this indication. C. *Acetaminophen, because unlike salicylates its use is not associated with increased risk of Reyes syndrome. D. Acetaminophen, because it has bronchodilator efficacy in asthmatics. E. Acetaminophen, because unlike NSAIDs it has antipyretic efficacy. Asthma (β2, airway smooth muscle relaxation) Terbutaline, albuterol a. Metered-dose Inhalers: A fixed dose of propellant containing suspended drug particles is released through a valve during a deep breath, although only about 12% of the measured drug dose actually reaches the alveoli. Preferred for bronchodilators and anti-inflammatory therapy, because side effects are minimized. [Examples: Atrovent® (ipratropium bromide, a bronchodilator for chronic obstructive pulmonary disease; COPD) and Azmacort® (triamcinolone acetonide, a steroid for asthma), and many brands of albuterol.] b. Nebulizers: i) In jet nebulizers, used chiefly in hospitals, a high flow gas shears liquid strands from a drug solution; when the strands hit a baffle they are fractured into drug-containing particles that are then inhaled through a mask placed over the nose and mouth. ii) Ultrasonic nebulizers, which can be used at home, expel particles from a "geyser" formed from a drug solution by generating ultrahigh frequency sound into a similar mask. Both kinds of nebulizers can be used with some of the same drugs that are used in metered dose inhalers. c. Diskus: a handheld plastic disk with mouthpiece that contains powdered formulations of drugs in double-foil blister strips; activation opens the blister and releases the drugs into the airway. [Examples: Advair Diskus® (fluticasone, an anti-inflammatory steroid for asthma and salmeterol, a bronchodilator for asthma)]
51. According to regulations of the Drug Enforcement Agency, a Schedule I drug: A. May be marketed as Over-the-Counter (OTC). B. Has refill limits. C. *May not be legally used in medical practice. D. Is unlikely to be abused. E. May only be used in a hospital setting I: Unsafe even under medical supervision: Heroin, LSD, Mescaline, Marijuana, Research use only, no currently accepted use in medical therapeutics II: Severe physical or psychological dependence: Written prescription required; no refills: Injectable codeine Morphine and other opioid agonists, hydrocodone and combination products Cocaine, amphetamines Pentobarbital and other barbiturates Nabilone and certain other synthetic cannabinoids III: Moderate to low physical, and high psychological dependence: Written or oral prescriptions; no more than 5 refills: Codeine combination products (no more than 90 mg per dosage unit)Several barbiturates Anabolic steroids Dronabinol and certain other synthetic cannabinoids IV: Limited physical or psychological dependence: Written or oral prescriptions; no more than 5 refills: Benzodiazepines Barbiturates not in other schedules V: Less risk of dependence than for Schedule IV: Other-the-counter (OTC), with some limits: Antitussives with no more than 200 mg codeine per 100 ml or 100 gm 50. FDA approval of a generic product, once the patent on a new drug expires, requires submission of data: A. From Phase 1, 2, and 3 of testing. B. * Documenting bioequivalence of the generic to the patented product, indicated in part by comparable bioavailability. C. From Phase 4 of surveillance for safety. D. Documenting reduction in cost to the patient. E. From preclinical studies. 49. The 'indication' of an FDA-approved drug: A. Is determined by Phase 3 studies that must include a placebo group, regardless of the disease or condition. B. Must be supported by evidence from Phase 1 studies, the purpose of which is to test efficacy in a controlled trial. C. Is the only purpose for which a physician may use the drug in an individual patient. D. * Must be stated in the 'label' (the package insert), which is published in the Physician's Desk Reference. E. Can be changed after marketing, based on case reports from physicians to the manufacturer, without FDA review. The Physician's Desk Reference (PDR), text and electronic equivalents, duplicates drug labeling (as approved by the FDA). The label (the "package insert") describes a drug's pharmacological and pharmacokinetic properties, its indications, contraindications, side effects, toxicity, drug interactions, dose forms, and information (when available) regarding use in special populations such as children and pregnant women. This resource is NOT a critical guide to use of drugs in medicine. In addition to drug labels, the PDR contains other information, such as color photographs of drug products to assist in their identification. 48. The purchase price of a drug product in the US: A. Is a fixed percent of the manufacturers' average wholesale price. B. Is reimbursed directly to the insured consumer. C. *Is based on a pricing algorithm that differs depending on the insurer and group discount purchasing. D. Is generally higher for generic products than the proprietary equivalents. E. Is determined by the FDA, based on pharmacoeconomic analyses. 3.1 The cost of drug therapy is comprised of the following: 3.1.1 Acquisition cost of the drug = price to the purchaser 3.1.2 Preparation and administration costs = cost of labor and materials required to dispense and administer drugs (i.e., pharmacy and nursing costs) 3.1.3 Monitoring costs = laboratory studies, follow-up visits 3.1.4 Adverse Events costs = toxicity, complications, failures 47. The MassHealth insurance program for drug costs of the poor and disabled in the state of Massachusetts: A. *Utilizes cost reduction strategies, such as drug formularies and pre-authorization procedures. B. Entails an annual cost that has steadily decreased in the last ten years. C. Represents less than 5% of the Massachusetts Medicaid expenditures for all health care costs. D. Has increased in cost, although the number of prescriptions per person in the US has decreased in the last ten years. E. Has increased in cost in recent years, primarily because claims for generic drugs have increased relative to proprietary drugs. 46. Part of an appropriate strategy for counseling patients with respect to herbal medicines is to: A. *Use databases such as Natural Standard or resources such as Consumerlab.com to access evidence-based information on quality, safety, and efficacy. B. Inform patients that herbal medicines are regulated by the government with respect to content of impurities such as lead. C. Inform patients that herbal medicines may be taken safely with FDA-approved drugs, because no interactions have been documented. D. Expect that almost all patients will inform you about use of complementary and alternative medicine without your asking. E. Avoid consideration or discussion of natural product use, because use by U.S. adults has declined in the last two decades and is uncommon. 45. The Dietary Supplement Health and Education Act (DSHEA) of 1994: A. Improved the safety of herbal medicines by setting standards for purity. B. Improved the potential for clinical study of herbal medicines by establishing methods for standardizing the content of active ingredients. C. Added vitamins and mineral supplements to the types of drug products that must be evaluated for safety in animal studies prior to marketing. D. Prohibits the FDA from removing herbal medicines from the market due to safety. E. *Does not require evidence of safety or efficacy prior to marketing of herbal medicines and dietary supplements The Dietary Supplement Health and Education Act of 1994 exempts products marketed as dietary supplements from FDA review for either efficacy or safety, or even purity. For example, controversy surrounds the marketing of melatonin for insomnia and jet lag because there is no need for controlled studies of its efficacy or safety, and many brands include unidentified impurities. However, food additives such as Olestra are regulated, especially for safety. 44. A patient presents at the emergency room with hypotension, bronchoconstriction, and rash after being stung by a wasp. The patient would be most reasonably treated with: Bee sting: a-receptor antagonist A. Norepinephrine: Postganglionic neuron: Norepinephrine, acting at adrenergic receptors (Exceptions: sweat glands innervated by cholinergic sympathetic fibers; dopamine in renal vasculature smooth muscle) B. Epinephrine: Adrenal medulla: Epinephrine, released into circulation C. Dopamine: specificD1 dopaminereceptors, β1>α1; endogenous agonist D. Neostigmine: Acetylcholinesterase inhibitor; Neostigmine Physostigmine E. Atropine: Muscarinic antagonist 43. Subsequent to myocardial infarction, a patient is given a prescription for carvedilol. The patient should be cautioned about which potential side effect? β-Adrenergic antagonists. a. Management of heart failure (carvedilol and metoprolol now approved by FDA) A. Hypertension ? B. Exacerbation of difficulty of urination in benign prostatic hyperplasia (BPH) (a-agonist, a-antag treats) C. Tachycardia (a-antag toxic reflex + ischemia: (increased oxygen demand from reflex tachycardia) D. Angina (b-antag toxic toxic) E. *Postural (orthostatic) hypotension (α-Antagonists) β1 + β2 + α1 is carvedilol, 42. A patient in the early stages of Alzheimer's Disease is prescribed donezepil, a centrally active acetylcholinesterase inhibitor, to improve his symptoms of confusion and memory loss. Which of the following autonomic side effects would be most likely to occur with this medication? more Ach A. Hypertension B. Exacerbation of glaucoma C. Diarrhea* D. Urinary retention E. Dry mouth 41. Which of the following would be most likely to be effective in reducing intraocular pressure in a patient with glaucoma? A. *A beta-adrenergic antagonist B. A muscarinic antagonist C. An alpha adrenergic antagonist D. A nicotinic antagonist E. A beta2 adrenergic agonist Ophthalmic: Ocusert® is a reservoir of pilocarpine contained in a flexible polymer membrane;muscarinin agonist, when placed within an eyelid pouch, the drug diffuses out through the membrane, maintaining miosis in patients with glaucoma for one week. Acetylcholinesterase inhibitors topical for glaucoma Topical beta-blockers reduce the intraocular pressure (IOP) by blockade of sympathetic nerve endings in the ciliary epithelium causing a fall in aqueous humour production. ... Betaxolol has an effect comparable to timolol in lowering IOP, but is less effective in some patients.
isoproterenol
B selective agonist (b1 = b2)
COX2
Cyclooxygenase enzyme that makes prostaglandins, thromboxanes, prostacyclins - the *bad* cox! Upregulates inflammation and cancer! <-- we want to just block COX2 and keep COX 1! - induced by cytokines, growth factors, and tumor promoters - assoc w/ inflammation and cancer - also constitutively expressed in brain, kidney, bone and GI tissues
Parasympathetic Nervous System CHOLINERGIC DRUGS ACh Nicotinic (N) Muscarinic (M) AChE: A + Ch = ACh
PS: 1. Ach N on skeletal muscles, Ach N on M3 exocrine glands, M2 heart, Ach onto sum nerves Ach on N adrenal medulla to release blood E. M: SM, Glands, Cardiac m Nicotinic Acetylcholine Receptor Top view Side view -Ligand gated ion channel - 5 subunits -Excitatory receptor that transports Na+, K+ and Ca+ -Activated in milliseconds -Prolonged exposure evokes refractory desensitized state in which agonist is bound but closes -Receptor will gradually "reset" after agonist dissociation (seconds to minutes) Nicotinic Acetylcholine Receptor: Antagonist: Muscle relaxants, ganglionic blocker, etc. Agonists: Carbachol, AcH, Nicotine. Nicotinic Acetylcholine Receptor Agonists *Acetylcholine -Endogenous neurotransmitter -Quaternary amine - does not penetrate cell membranes -Activates nicotinic and muscarinic receptors -Rapidly inactivated by acetylcholine esterase (AChE) at synapse and esterases in blood *Carbamylcholine -Quaternary amine -Activates nicotinic and muscarinic receptors -Esterase resistant analog of ACh - Tertiary amine, CNS penetrating, rapid acting, rapid clearance - Drug of abuse ACUTE TOXICITY - Via ingestion of nicotine-based insecticides or tobacco products by children or via dermal contact in tobacco workers 1- Rapid onset of abdominal pain, nausea, diarrhea, disturbed vision, weakness, mental confusion 2 - Stimulates parasympathetic and sympathetic nervous system 3 - Central simulation, can cause convulsion, coma and respiratory arrest 4 - Skeletal muscle depolarization via receptor desensitization ACUTE TOXICITY Treatment - Activated charcoal to reduce GI absorption - Benzodiazepine to control seizures - i.v. fluids to maintain/increase blood pressure - Atropine for bradycardia if needed Nicotine poisoning in infant: - Incidence increasing due to concentrated liquid forms - Patient vomiting, truncal ataxia and poor respiration - Ingested small amount of liquid containing 1.8% nicotine (18mg/ml) - 5ml of this solution could be lethal to a 90-kg adult - Patient recovered without antidote within 6 hours- Ingested 5 ml of liquid nicotine containing 10 mg/ml nicotine - Involuntary vomited after ingestion - Lost consciousness and was unresponsive - EMT found no pulse did 40min CPR - Needed mechanical ventilation - Pupils fixed and dilated and had fetal incontinence - Feet and hands clammy - Brain edema - Never regained consciousness - Died on 44th day in hospital Neuromuscular (NMJ) Blocking Agents Non-depolarizing blockers (competitive) e.g., tubocurarine - Competitive inhibition of ACh binding to nicotinic receptor at skeletal muscle endplate - When approx 70% bound prevent ACh evoking muscle contraction - Results in flaccid paralysis of all skeletal muscle - Indirectly antagonized by AChE inhibitors which increase endogenous ACh (used post surgically to speed recovery) USED IN SURGERY TO PROMOTE SKELETAL MUSCLE RELAXATION - Tracheal Intubation e.g., succinycholine - Maintain controlled ventilation - Paralysis of skeletal muscle in area of surgery - To set fractures e.g., succinycholine Depolarizing blockers (non-competitive) e.g., succinycholine Mechanism of action: -Binds to nicotinic ACh receptor (nicotinic agonist) -Evokes receptor desensitization and voltage-gated channel inactivation -Nicotinic ACh receptors enter a desensitized state upon prolonged exposure to agonist -Receptor will gradually "reset" after agonist dissociation -Rapid onset and short duration of action - recover within minutes of infusion termination -Rapidly hydrolyzed by plasma cholinesterase - Cholinesterase inhibitors prolong effect as increase endogenous ACh receptor activation Neuromuscular Blocking Agents Depolarizing blockers (non-competitive) e.g., succinycholine Stages of block: Fasciculation: Initial excitation and disorganized muscle fiber contractions due to non-synchronous muscle receptor activation Phase I block (depolarizing): Prolonged depolarization due to persistent nicotinic ACh receptor activation leads to voltage-gated sodium channel inactivation. Muscle exhibits flaccid paralysis. Phase II block (desensitizing): Nicotinic ACh receptor activation progresses to receptor desensitization and receptor-operated channels close. Muscle repolarizes, but continues to exhibit flaccid paralysis due to non-responsiveness of ACh receptors. Skeletal Muscle Relaxants: Toxicity • Nondepolarizing - Histamine release with tubocurarine and some related agents • Depolarizing (succinylcholine) - Malignant hyperthermia in patients with this genetic skeletal muscle disorder (features excess Ca2+ release in skeletal muscle) • Incidence: 1 in 4,500-60,000 surgical procedures • Treatment: dantrolene (prevents Ca2+ release) - Prolonged action in patients with atypical plasma cholinesterase Skeletal Muscle Relaxants: Toxicity • Depolarizing (succinylcholine) -Hyperkalemia - potentially life threatening Due to intracellular K+ release through nicotinic ACh receptor channels Increased risk in burn and immobilized patients (due to ACh receptor up regulation) -Cardiac dysrhythmias, primarily due to stimulation of cardiac muscarinic receptors (usually bradycardia, although tachycardia is sometimes seen, particularly with high doses) -Postoperative muscle pain (mechanism unclear) Hereditary deficiency of which of the following enzymes can lead to prolonged effects of succinylcholine? Plasma cholinesterase b. Plasma cholinesterase c. Heme oxygenase d. Cytochrome oxidase e. Liver transaminase Botulinum toxin: A denervating protein toxin • Bacterial protein toxin (m.w. ~150,000) • Binds specifically to cholinergic nerve terminals, internalized into cytoplasm • Enzymatically degrades protein factors required for vesicle fusion and ACh release • Produces prolonged presynaptic impairment of cholinergic neurotransmission resulting in localized skeletal muscle paralysis • Prolonged action (months) - recovery due to axonal sprouting • FDAapprovedfor - Cosmetics (reduction of facial wrinkles) - Treatment of cervical dystonia (spasmodic torticollis) - Treatment of spasticity in flexors of elbow, wrist, fingers - Treatment of strabismus (misalignment of the eyes) - Treatment of blepharospasm - Treatment of severe primary axillary hyperhydrosis (excessive underarm sweating) - Treatment of urinary incontinence associated with neurologic conditions - Treatment of localized muscle cramps • Off-label uses include - Treatment of spasticity - Treatment of nondystonic muscle activity disorders e.g., tics, tremor - Treatment of localized muscle cramps - Treatment of smooth-muscle hyperactive disorders • Muscle weakness (may be long-lasting) - Difficulty in eating/swallowing (particularly with use in head & neck) - Paralysis of respiratory muscles, can result in death • FDA Warning (2008) - botulinum toxin has "been linked in some cases to adverse reactions, including respiratory failure and death, following treatment of a variety of conditions using a wide range of doses." • Treatment of botulism: antitoxin (but does not reverse toxicity once botulinum toxin has entered the nerve terminal) Muscarinic Acetylcholine Receptor M1M3M5: PLC, DAG, IP3 M2M4: -cAMP + K -Ca2+ channel Non-selective (N+M): Ach carbachol M selece EFFECTS OF STIMULATING MUSCARINIC RECEPTORS Bradycardia, NO Vasodilation, Bronchoconstriction, Miosis, More urnination, more tears, more sweating MUSCARINIC AGONISTS (parasympathomimetics) ACh - no clinical use!!!! Pilocarpine -NO nicotinic effects -Some selectivity for salivary glands -Used orally to treat xerostomia -Used topically to treat glaucoma Bethanchol -NO nicotinic effects -Some selectivity for bladder -Used orally to treat post-op urinary retention -Stimulates GI activity Carbachol -Pupil contraction for ophthalmological surgery Muscarinic Agonists: Toxicity • Salivation • Lacrimation (tear secretion) • Urination • Diarrhea • GI upset • Emesis (vomiting) • Bronchoconstriction • Hypotension • Bradycardia Muscarinic Antagonists: BELLADONNA ALKALOIDS Atropine and Scopolamine Trycyclic antidepressants and antihistamines have anti muscarinic effects Antimuscarinic drugs cause: tachycardia, vasodilation from feedback, bronchdilation, MYDRIASIS, DECREASED GI MOTILITY, DECREASED SALIVATION, DECREASED TEARS, DECREASED SWEATNG Antimuscarinic Agents BELLADONNA ATROPINE ALKALOIDS SCOPOLAMINE TX: USED WHEN A REDUCTION OF PARASYMATHETIC TONE IS DESIRABLE • Reduce tremor • Preop to reduce salivations / bronchial secretions • Treat rhinitis (inflammation of nasal membrane) • Reduce intestinal motility • Prevent vagal stimulation of heart during MI (i.e., reduce HR) • Treat overactive bladder • Ophthalmological examinations • Prevent motion sickness (scopolamine, CNS action) • Treat bronchoconstriction (asthma) • Treat AChE inhibitor poisoning or muscarinic agonism Antimuscarinic side effects and toxicity DRYASABONE HOTASAPISTOL REDASABEET BLINDASABAT MAD AS A HATTER • e.g., Deadly nightshade • Dry mouth • Dry, hot skin • Dilated pupils • Blurred vision • Flush • Delirium • Tachycardia • Urinary retention, constipation • Exacerbation of glaucoma (esp. narrow-angle) • Hyperthermia (esp. in children) • Sedation (particularly with scopolamine) • Give pt Physostigmine (ACh-esterase inhibitor) Which one of the following agents, when applied topically to the eye, would induce mydriasis?: Atropine Carbachol (muscarinic agonist) causes pupil constriction (myosis). Atropine Atropine (muscarinic antagonist) causes mydriasis (pupil dilation) Acetylcholinesterase (AChE) Inhibitors ACh - normally removed from synapse via AChE AChE inhibitors reduce AChE activity Increase ACh concentrations ENHANCE TRANSMISSION AT CHOLINERGIC JUNCTIONS Cholinesterase (AChE) Inhibitors Carbamate esters Primary clinical class - form reversible covalent bond Physostigmine -Penetrates CNS, drug of choice to treat atropine poisoning Neostigmine -No CNS penetration (quaternary amine) •Treatment of Alzheimer's Disease •Myasthenis gravis •Accelerating recovery from nondepolarizing muscle relaxants •Treatment of postsurgical paralytic ileus •Treatment of urinary bladder atony •Antimuscarinic antidote (atropine = competitive blocker) Cholinesterase (AChE) Inhibitors Organophosphates - IrreversibleAChEinhibitorsvia phosphate bond Insecticides e.g., Parathion Nerve Gases e.g., Sarin • Muscarinic toxicity (SLUDGE, bronchoconstriction) • Neuromuscular blockade • Respiratory failure • Confusion, coma, convulsions Antidote for Muscarinic Responses Produced by Overdose of Cholinesterase Inhibitors: Atropine ENHANCE TRANSMISSION AT CHOLINERGIC JUNCTIONS -Evokes muscarinic toxicity (SLUDGE) -Atropine blocks action at Muscarinic NOT Nicotinic receptors Pralidoxime - cholinesterase regenerator - Atropine blocks action at Muscarinic NOT Nicotinic receptors - PRALIDOXIME - Oximes bind organophosphate inactivated AChE - treat organophosphate poisoning or toxic gas exposure - Effects N and M responses Esteric site blocked by organophosphate blocking activity Anionic site free - Pralidoxime binds here Pralidoxime then binds to organophosphate changing its conformation Organophosphate and pralidoxime complex unbinds AChE function restored Efficacy in organophosphate treatment remains controversial Jimson weed (belladonna alkaloids) (Atropine-like toxicity have the opposite effect. i.e. Mad as a hatter, dry as a bone, blind as a bat, hot as hell.) Parathion (Parathion is a cholinesterase inhibitor, which will lead to accumulation of Ach. Symptoms are signs of Ach excess). Poisoning with malathion insecticide (organophosphate) is best managed by administration of which one of the following agents? Atropine (Atropine blocks the muscarinic effects of increased Ach resulting from cholinesterase inhibition). Pilocarpine Pilocarpine is a direct muscarinic agonist. This will make the situation much worse . Bethanechol Bethanechol is a direct muscarinic agonist. This will make the situation much worse. Physostigmine Physostigmine is a inhibitor of cholinesterase, increase Ach effect. This will make the situation much worse
his programmed problem set is designed to help you learn and apply the concepts and vocabulary in Pharmacokinetics that have been introduced to you in lectures and text. The primary terms that you should master from this exercise are Half-life (t1/2), Volume of Distribution (Vd), Renal Clearance (ClR), Total Clearance (ClT), and Bioavailability (F). Their definitions and methods for calculating these parameters are presented in the Pharmacology Glossary posted online and the lecture syllabus. You should complete this program before the first Pharmacology Discussion Session. Bring to that class any questions that arise during your use of this program. The first Discussion Session is designed to reinforce and expand upon the groundwork in pharmacokinetics presented in this problem set. In order to help organize your interpretation of the data, a summary table is available for your use to enter in pharmacokinetic parameters as you determine them. Click here now to bring up the summary table page. Fill in the table as you work through the problem set, and then bring it with you to the discussion session on pharmacokinetics. Chloramphenicol is a clinically useful antibiotic with the following chemical structure: The compound is uncharged over the pH range 2-9 and is poorly soluble in water. The concentration of chloramphenicol added to biological fluids may be determined in several ways: Bioassay: determination of the capacity of a sample to inhibit growth of microorganisms in vitro as compared to the capacity of a series of standards containing known amounts of chloramphenicol. Biotransformation products of chloramphenicol, produced in man and experimental animals, are inactive against microorganisms, so a bioassay of a sample containing both chloramphenicol and its metabolites measures unchanged chloramphenicol only. (Why would such an assay for chloramphenicol possibly be inappropriate in a patient receiving multiple antibiotic agents?) Chemical assay for nitro groups: NO2 groups are not present in mammalian fluids, so a chemical assay for this substituent can be used to quantitate chloramphenicol. But there is a problem with the accuracy, specifically the validity, of this assay because it detects all derivatives of chloramphenicol formed in vivo in which the NO2 remains but other parts of the molecule are modified. (Where might this molecule be modified? HINT: Might the aliphatic hydroxyl group be a site for glucuronide conjugation?) High-performance liquid chromatography (HPLC) or radioenzymatic assays: the advantage of these procedures is their capacity to assay specifically the concentration of the chloramphenicol molecule by chemical methods, and to distinguish chloramphenicol from its major metabolite (chloramphenicol glucuronide) and from inactive esteratic prodrug forms (chloramphenicol succinate or palmitate). For this programmed problem set, you will be analyzing preclinical data collected during the initial development of this drug. The biological disposition of chloramphenicol was studied in dogs, as is currently required by F.D.A. regulations for all new drugs. Experiments from two normal male dogs are presented below. One animal, weighing 16.5 kg, received a single dose of 50 mg/kg (825 mg total) intravenously (i.v.); the second, weighing 18.0 kg, received 50 mg/kg (900 mg total) of chloramphenicol orally (p.o.). For both animals, serum and urine samples were collected at various times after drug administration and analyzed by bioassay for their content of microbiologically active material (unchanged chloramphenicol). (These data are taken from the studies published in the Journal of Pharmacology and Experimental Therapeutics by the investigators at Parke-Davis who were responsible for the preclinical development of this drug prior to its marketing.) Complete urine collections were made during the period following administration of chloramphenicol. The concentration of chloramphenicol in each urine sample was determined and multiplied by urine volume to determine the amount of drug excreted in the urine in each interval (see below). The following program will guide you through an evaluation of the data to conclusions about the pharmacokinetics of chloramphenicol. Your first step for each question should be to inspect the data and estimate the pharmacokinetic parameter required to arrive at the answer. These are the skills you will most often use in interpreting clinical data or the clinical literature. You may better understand these data if you graph them and complete a regression analysis of ln Cp vs. time. Use this Cp vs Time spreadsheet and enter the plasma concentration (Cp) data from above, before moving on to Item I. If you find that you have difficulty working with these data, please consult a faculty member or tutor before the first discussion session.
Qs
Role of Laboratory Medicine Every clinician depends on the laboratory to optimally care for their patients. It has been estimated that laboratory results are critical in 70% of patient care decisions, including diagnosis, monitoring treatment, admittance to a hospital, and discharge.
The Steps of Laboratory Analysis It all starts with the clinician who decides that they want a particular laboratory test to aid in the diagnosis or management of a patient. Pre-analytic phase: The physician, nurse, medical student, or phlebotomist obtains the sample. The sample is brought to the laboratory, where it is accessioned and prepared for analysis. Pre-analytic variables for optimal laboratory resulting: Proper identification of the patient and labeling of the specimen are key pre-analytic steps. Timing of collection is important for tests requiring a fasting state (i.e. glucose, lipid panel, etc.) or in therapeutic drug monitoring (i.e. peak vs trough sample). Using the right tube for the given test, because some tests can only be performed in samples collected in a specific tube.
absolute bioavailability vs relative
absolute F = (AUC non iv / AUC iv) x 100 relative F = (AUCgeneric / AUC proprietary) x 100
methotrexate MTX small, low MW molecule purine/prymidine synthesis inhibitor inhibition of thymidine-MP synthesis; reduces availability of folate for thymidylate and DNA synthesis; arrest of DNA replication inhibition of de novo purine (ionosine) synthesis
antineoplastic (chemotherapy) cell death, infection, etc. HIGH DOSE anti-inflammatory, antirheumatic effect LOW DOSE
which second messenger pathway do m2 and m4 receptors use? where are m2 found?
dec. cAMP, inc. K+ channel activation (By), dec. Ca2+ channel activation (By) m2 cardiac receptors - dec. HR and contractility
effusion vs edema
effusion: - the escape of fluid into a *defined* cavity - can be transudate or exudate - can get out w/ needle since it's a defined space edema: - the accumulation of fluid into the interstitium of tissues or alveolus - more diffuse; can't get out w/ needle - also can be transudate or exudate
B1 receptor: 2nd messenger & effects
inc. cAMP - heart = inc. force (+inotropic), inc. HR (+ chronotropic), inc. AV conduction velocity (i.e. inc. systolic pressure) - kidney = inc. renin release
B2 receptor: 2nd messenger + effects
inc. cAMP - smooth muscle: relaxation (i.e. dec. diastolic pressure) - skeletal muscle: glycogenolysis - liver: glycogenolysis, gluconeogenesis
D1 rec: 2nd messenger & effect
inc. cAMP dilates renal vasculature
types of germ cell tumors
seminoma embryonal cell carcinoma choriocarcinoma
1. The chemistry lab performs testing for chemical compounds or proteins such as blood gases, electrolytes, liver function tests, cardiac function tests, renal function tests, pancreas function tests, hormones, autoimmune disease tests, tumor markers, immunoglobulin tests, toxicology, therapeutic drug monitoring, etc. 2. The hematology lab performs blood counts, morphologic cell identification (peripheral blood smear, urinalysis, body fluids), routine and special coagulation, hemolysis tests, hemoglobinopathy tests, flow cytometry, etc. 3. Themicrobiologylabperformstestsformicroorganism(bacteria,virus,fungi, parasites) identification. They also perform antibiotic susceptibility testing, viral load and genotype testing.
4. The blood bank provides blood products for transfusion and performs tests that ensure safe transfusion such as type and screen as well as a crossmatch. Some blood banks operate a blood donor center or perform blood replacement procedures (red cell exchange, plasmapheresis). 5. Laboratory information system (LIS) is used to automate most of laboratory medicine functioning for minimizing human errors and maximizing efficiency. This includes correct test ordering, correct specimen tube for the particular test, direct interfacing with laboratory instruments for test order and test result, and direct interfacing with the electronic medical record (EMR) for the reporting of lab tests, etc. LIS can also be used to make sure correct results are reported on the correct patient such as delta checks i.e. a person who historically had O- blood type but now the patient's friend using their insurance information and assuming their identity has A+ blood type. 6. Point of care (POC) testing refers to tests performed by clinicians at the patient's bedside such as fingerstick glucose, Guaiac test, etc. Such testing is overseen by laboratory medicine (from an operation and compliance standpoint) despite not being physically performed in the lab.
Chronic and Granulomatous Inflammation Inflammation that persists for more than a few days. Typical causes Prolonged exposure to injury/irritants etc. Immune mediated diseases (autoimmune, allergies) Persistent infections (results in granulomatous inflammation)
Acute: All but fibroblasts Chronic: All but neurtophils Wound healing phases: Note that the first phases are in minutes while later phase are weeks - months. 9 Sources of monocytes\macrophages: Bone Marrow, Blood monocyte, skin macro, resident cell macro, yolk sac. Macrophage - Critical Cell: 1. Classic activation: IFNy ROS NO Lysozyme: Bacteria and Fungi die. IL-1,IL-12,IL-23 Inflammation. M2: TGF-B fibrosis. IL-10,TGF-B: anti-inflammatory (activation by Il-13 IL-4). Acute inflammation becoming chronic Layers in ulcer = Sequence 1. Top Layer - Fibrinopurulent exudate - fibrin strands + PMNs 2. Middle layer - Granulation tissue , Angiogenesis, Mixture of Inflammatory cells 3. Bottomlayer-Scar- Red collagen, trapped nerve fiber, Granulation tissue - gross: Healing wound Skin excised and allowed to heal Red appearance due to blood flow on base of wound Chronic Inflammation Rheumatoid arthritis: Swollen Joint: Purple spots are collections of macrophages + lympohycytes, synovium on outside. Complex lymphocyte macrophage interaction: Active TH1 Th17 using IL17 TNF Active macrophage using TNF Il1 MEDIATORS: TNF: local [c]> systemic, inhibition improves chronic outcomes, IL-1 local+, overlap fx tnf TNF inhibitors approved for chronic inflammation: 4 Ab TNF, TNFsolublereceptors Examples of diseases treated with cytokine inhibitors • Rheumatoid arthritis • Crohn's disease • Psoriatic arthritis • Ankylosing spondylitis • And others Infliximab Anti-TNF Ab Kufperr cells induce Interleukin-6 which increases acute phase protein synthesis • Synthesis - Macrophages (especially Kupffer cells), fibroblasts, endothelial cells, also by activated T-cells • Biological actions - Stimulates synthesis acute phase reactants in liver - Systemic effects: fever - Growth of antibody-producing B lymphocytes Acute Phase Proteins (indicates how much the reactant increases) Alpha 1 Anti-trypsin (x 2-3) Alpha 1 Anti-chymotrypsin (x 2-5) Haptoglobin (x 1-2) Ceruloplasmin (x 2-5) Fibrinogen C3 C-Reactive Protein (x 5-500) Hemopexin Serum Amyloid A Protein Erythrocyte Sedimentation Rate ESR, Sed Rate APR: # tests/year at BMC CRP - 10,000 ESR - 11,000 Haptoglobin - 1,400 Asthma - chronic inflammation Asthma - Peribronchial Inflammation Asthma Attack Acute exacerbation of a chronic disease Granulomatous Inflammation • Granuloma: At a minimum, an aggregate of macrophages usually arranged concentrically around a pathogen or irritant. • Typical description - Focus of epithelioid macrophages surrounded by a collar of lymphocytes • Only associated with certain specific pathologic conditions. Attempt by the host to contain and eliminate an insult too great for a single cell alone. Combination of cells Epithelioid macrophages Lymphocytes Multinucleated giant cells Fibroblasts Infectious Mycobacteria (tuberculosis, leprosy) Coccidiomycosis Blastomycosis Spirochetes Many others Foreign Body Idiopathic - Sarcoidosis, Crohn's Disease Granulomas - Tuberculosis in Lymph Node: Caseuous Necrosis: Epitheliod macro, lympocytes, multinucleated giant cells RA: TNF inhibitor blocked the chronic inflammation. The response to therapy was measured by CRP However, blocking the inflammatory response allowed re-activation of the tuberculosis by allowing the mycobacteria to escape the inflammation keeping the pathogen under control. -Granulomatous Inflammation Coccidiomycosis - -Kidney Spherule with endospores -Granulomatous Inflammation Lung - Blastomycoses - Skin - Granulomatous Leprosy -Foreign Body Suture Granuloma, Polarized Light Sarcoidosis Crohn's disease - inflammatory disease of bowel Wegener's granulomatosis - necrotizing vasculitis, anti-neutrophil abs Chronic granulomatous disease - inherited deficiency of NADPH oxidase
Why are cytoplasmic proteins from hepatocytes (AST & ALT) released into the blood?
Death of hepatocytes leads to release of their cytoplasmic proteins into blood.
Market sales
Herbal sales have shown slow growth since 2004. Obtaining accurate market data that capture all of US herbal sales is difficult. This is due in part to the multiple channels available for purchasing supplements such as drug stores, supermarkets, warehouse buying clubs, natural food stores, multilevel marketing, health professionals, and the Internet. Nonetheless, using multiple survey methods, total sales of herbal and dietary supplements in the United States were estimated to be $5.6 billion for 2012, a 5.5 percent increase from 2011 [10]. Reasons for use — Americans reported that their top reasons for using herbs and supplements were enhancing health and helping with common chronic symptoms or diseases such as memory loss, arthritis, and fatigue [11]. In this way, herbs are similar to other complementary and alternative medicines in that they are frequently used for chronic conditions for which conventional medicine does not offer straightforward answers or cures. Herbs are also appealing to those who perceive nature as benevolent and healing [12]. Associated with this is the mistaken perception that a naturally derived product is always safe. Regulation — In the first half of the 20th century, medicinal herbs were included in the United States National Formulary and the United States Pharmacopoeia (USP). In 1962, outrage over limb defects from thalidomide prompted Congress to pass the Kefauver-Harris Drug Amendment. This required proof of safety and efficacy for all prescription and over-the-counter drugs and reassigned herbal medicines to the category of food supplements which have a lower threshold of required evidence for safety [13]. In the early 1990s, the US Food and Drug Administration (FDA) attempted to develop more strict regulations for herbal products. This was opposed in a campaign by consumers, supplement manufacturers, and political advocates. The result was a 1994 bill passed by Congress called the Dietary Supplement Health and Education Act (DSHEA). DSHEA defined dietary supplements as a product containing one or more of the following: a vitamin, mineral, amino acid, herb, other botanical, concentrate, metabolite, constituent, or extract [13]. DSHEA placed dietary supplements in a distinct category from drugs. Labels of dietary supplements are required to state: "this product in not intended to diagnose, treat, cure, or prevent any disease." However, product labels are allowed to make health claims, such as "promotes prostate health" or "supports the circulatory system." Importantly, makers of dietary supplements are not required to prove efficacy, safety, or quality of a product prior to marketing. Supplement manufacturers are also not obligated to report postmarketing adverse events to the FDA. DSHEA therefore moved the burden of proving that a product is unsafe or ineffective to the FDA. For various reasons, the FDA has infrequently removed a dietary supplement product from marketing. Products containing ephedra, androstenedione, and PC-SPES are notable exceptions. Increasing research, case reports, and publicity of adverse effects and harmful drug-herb interactions have prompted many clinicians, physician organizations such as the Institute of Medicine, and consumer groups such as the Center for Science in the Public Interest to call for reform of DSHEA [14-16]. National surveys found that 81 percent of Americans believed evidence of safety should be required before allowing the sale of a supplement [17]. However, more than half did not understand that current regulations did not require such evidence. Thus, the public appears to be sensitive to safety issues and supportive of greater regulation. In 2007, the FDA issued new rules requiring Good Manufacturing Practices (GMPs) for dietary supplements [18]. The new GMPs require dietary supplements be properly labeled, free of adulterants, and manufactured according to specified standards for personnel and equipment. However, the rules allow manufacturers, in particular smaller companies, significant flexibility to specify the quality criteria they will follow. As an example, there are no specified maximum acceptable concentrations or daily dose limits for heavy metals such as lead [18]. There is concern whether the GMPs are being uniformly followed. Since 2010, 71 percent of 626 FDA inspections of supplement manufacturers resulted in citations for not following the new standards; on average, each company was cited for seven deviations [19]. Furthermore, one study found that many supplements recalled due to adulteration with pharmaceutical ingredients were still available for purchase six months after the recall [20].
Fluoxetine
Inhibits 5HT reuptake. (Drug binding to receptor to block transport)
Herbal Article
Plants have been used for medicinal purposes for thousands of years. All major cultures, including Native American, European, South American, Asian, and African cultures, have used botanicals for healing purposes. As an example, saw palmetto was used for urinary symptoms in men from Egypt in the 15th century BCE [1]. Hippocrates documented the use of St. John's wort for mood ailments in the 5th century BCE [2]. The Inner Classic of the Yellow Emperor around 100 BCE describes complex traditional Chinese herbs [3]. Herbal medicines flourished in Europe in the 17th century, then showed a decline with the Scientific Revolution. European immigrants brought to North America their own herbal medicine traditions as well as acquiring many from Native Americans. Two-thirds of entries in the first edition of the United States Pharmacopoeia (USP) published in 1820 were botanical substances [2]. After about 1920, standardized pharmaceutical drugs increasingly replaced herbal therapies in the United States. Synthetic drugs were found to have larger pharmacologic effects and greater profitability [2]. Over 120 conventionally used pharmaceuticals are derived from plant species (table 1) [2,4]. In the United States, in response to increased public interest and use of complementary and alternative medicines, Congress established the National Institutes of Health (NIH) Office of Alternative Medicine (OAM) in 1992. The NIH Office of Dietary Supplements was created in 1994 to conduct and coordinate research in herbs and supplements. In 1998, the NIH OAM was upgraded to the National Center for Complementary and Integrative Health (NCCIH). NCCIH has prioritized evaluating mechanisms, efficacy, and safety of botanical medicines through basic science studies, clinical research, and the establishment of dedicated botanical research centers [5]. A list of commonly used herbs and supplements is provided below with links to more information about use, efficacy, and safety elsewhere in UpToDate and from the US National Library of Medicine (NLM) and the European Medicines Agency (EMA) websites. General concerns about quality and safety are reviewed below. (See 'Commonly used herbs and supplements' below and 'Quality and efficacy' below and 'Safety' below.) Several specific herbs and supplements are discussed in detail elsewhere. A partial list follows. (See "Vitamin supplementation in disease prevention" and "Complementary and alternative remedies for rheumatic disorders" and "Complementary and alternative therapies for cancer" and "Complementary and alternative therapies for allergic rhinitis and conjunctivitis" and "Complementary and alternative treatments for anxiety symptoms and disorders: Herbs and medications".) Commonly used herbs and supplements ● Acai (Euterpe oleracea) - National Center for Complementary and Integrative Health (NCCIH) 1 of 26 6/21/2017 12:22 PM Overview of herbal medicine and dietary supplements - UpToDate https://www.uptodate.com/contents/overview-of-herbal-medicine-and-die... ● Black cohosh (Actaea racemosa, Cimicifuga racemosa) (see "Menopausal hot flashes", section on 'Role of complementary and alternative therapies') - NLM MedlinePlus, NCCIH, and EMA Community Herbal Monograph (EMA) ● Chamomile (Matricaria recutita) (see "Infantile colic: Management and outcome", section on 'Herbal remedies') - NCCIH ● Capsicum pepper, cayenne (Capsicum frutescens, Capsicum annuum) (see "Complementary and alternative therapies for allergic rhinitis and conjunctivitis", section on 'Capsaicin (Capsicum annum)' and "Cancer pain management: Adjuvant analgesics (coanalgesics)", section on 'Other local anesthetics' and "Management of knee osteoarthritis", section on 'Other nutritional supplements' and "Management of knee osteoarthritis", section on 'Glucosamine and chondroitin') ● Coenzyme Q10 (Ubiquinol, Ubiquinone, Ubidecarenone) (see "Mitochondrial myopathies: Treatment", section on 'Coenzyme Q10 deficiency' and "Statin myopathy", section on 'Coenzyme Q10' and "Investigational and emerging therapies for heart failure", section on 'Growth hormone' and "Investigational and emerging therapies for heart failure", section on 'Coenzyme Q10') - National Cancer Institute (NCI) ● Cranberry (Vaccinium macrocarpon, Vaccinium oxycoccos) (see "Urinary tract infections in children: Long-term management and prevention", section on 'Cranberry juice' and "Recurrent urinary tract infection in women", section on 'Cranberry products') - NCCIH ● Creatine (see "Unipolar depression in adults and initial treatment: Investigational approaches", section on 'Creatine') - NLM MedlinePlus ● DHEA (Dehydroepiandrosterone) (see "Dehydroepiandrosterone and its sulfate") - NLM MedlinePlus ● Echinacea (Echinacea angustifolia) (see "Clinical use of echinacea") - NCCIH ● Evening primrose oil (Oenothera biennis) (see "Treatment of atopic dermatitis (eczema)", section on 'Dietary supplements' and "Menopausal hot flashes", section on 'Role of complementary and alternative therapies') - NCCIH and EMA ● Feverfew (Tanacetum parthenium) (see "Preventive treatment of migraine in adults", section on 'Feverfew') - NCCIH and EMA ● Fish oil (see "Fish oil and marine omega-3 fatty acids") ● Flax, flaxseed oil, linseed (Linum usitatissimum) (see "Lipid lowering with diet or dietary supplements", section on 'Fish oil and omega-3 fatty acids') - NCCIH and EMA ● Garlic (Allium sativum) (see "Lipid lowering with diet or dietary supplements", section on 'Garlic') - NCCIH ● Ginkgo biloba (see "Clinical use of ginkgo biloba") - NCCIH ● Ginseng (Panax quinquefolius, Panax ginseng, Eleutherococcus senticosus) (see "Complementary and alternative therapies for cancer", section on 'Ginseng and guarana for fatigue' and "Chinese herbal medicine for the treatment of allergic diseases", section on 'Modified Mai Men Dong Tang (mMMDT) formula') - NLM MedlinePlus (American and Siberian) and EMA 2 of 26 6/21/2017 12:22 PM Overview of herbal medicine and dietary supplements - UpToDate https://www.uptodate.com/contents/overview-of-herbal-medicine-and-die... ● Glucosamine and chondroitin (see "Subacute and chronic low back pain: Nonpharmacologic and pharmacologic treatment", section on 'Glucosamine' and "Management of knee osteoarthritis", section on 'Glucosamine and chondroitin') - NLM MedlinePlus (glucosamine hydrochloride and glucosamine sulfate) and NLM MedlinePlus (chondroitin sulfate) ● Green tea (Camellia sinensis) (see "Complementary and alternative therapies for cancer", section on 'Green tea' and "Benefits and risks of caffeine and caffeinated beverages", section on 'Consumption') - NCCIH ● Hawthorn (Crataegus monogyna) (see "Investigational and emerging therapies for heart failure", section on 'Hawthorn extract') - NCCIH ● Horse chestnut seed extract (Escin, Aesculus hippocastanum) (see "Medical management of lower extremity chronic venous disease", section on 'Escin (horse chestnut seed extract)') - NCCIH and EMA ● Kava (Piper methysticum) (see "Hepatotoxicity due to herbal medications and dietary supplements" and "Pharmacotherapy for generalized anxiety disorder in adults") - NCCIH ● Melatonin (see "Physiology and available preparations of melatonin") ● Milk thistle (Silymarin, Silybum marianum) (see "Emerging therapies for hepatic fibrosis", section on 'Silymarin') - NCI and NCCIH ● Omega-3 fatty acids (see "Fish oil and marine omega-3 fatty acids") - NCCIH ● Probiotics (see "Probiotics for gastrointestinal diseases") - NCCIH ● S-adenosylmethionine (SAMe) (see "Prognosis and management of alcoholic fatty liver disease and alcoholic cirrhosis", section on 'S-adenosylmethionine') - NCCIH ● Saw palmetto (Serenoa repens) (see "Clinical use of saw palmetto") - NCCIH ● Soy isoflavones (Glycine max) (see "Lipid lowering with diet or dietary supplements", section on 'Soy' and "Preparations for menopausal hormone therapy", section on 'Phytoestrogens' and "Overview of the management of osteoporosis in postmenopausal women", section on 'Therapies not recommended') - NCCIH ● St. John's wort (Hypericum perforatum) (see "Clinical use of St. John's wort") - NCCIH ● Valerian (Valeriana officinalis) (see "Treatment of insomnia in adults", section on 'Over-the-counter') - NCCIH and EMA
Policy for Interactions with Industry by Faculty/Clinicians at the Boston University School of Medicine
Purpose: Page: 1 Approved by the BUSM Executive Committee on August 20, 2014 Policy for Interactions with Industry by Faculty/Clinicians at the Boston University School of Medicine To establish Boston University School of Medicine ("BUSM") standards governing the relationship between BUSM faculty/clinicians and for-profit commercial providers of services or supplies that support patient care, including entities that provide pharmaceuticals (including biologics), medical devices, clinical services or supplies, as well as intermediary organizations retained by such entities (hereinafter "industry" or "vendors"). Policy Statement: This policy, together with Boston University's Conflict of Interest Policy and other related policies, provides the standards by which all BUSM faculty/clinicians are expected to conduct themselves when dealing with industry. Although relationships between faculty/clinicians and vendors can facilitate a mutually beneficial exchange of information about products or services relevant to patient care, these relationships can also create the potential for conflicts of interest and abuse. These standards are designed to protect the integrity of clinical decision making and to ensure that faculty/clinicians comply with all relevant federal and state laws and regulations including, but not limited to, the anti-kickback and self-referral laws, Prescription Drug Marketing Act, Massachusetts Pharmaceutical and Medical Device Manufacturers Conduct Law and the laws governing tax-exempt organizations. This policy draws upon the guidance issued by the Office of Inspector General, the American Medical Association, the Accreditation Council for Continuing Medical Education ("ACCME"), the Pharmaceutical Research and Manufactures of America (PhRMA) and the Advanced Medical Technology Association (AdvaMed). This policy does not apply to dealings between industry and BUSM with respect to funding for research. Such relationships are covered by the BU Policy on Investigators' Conflicts of Interest, as administered by the BUMC Advisory Committee on Investigators' Conflicts of Interest. For activities where continuing medical education ("CME") credit is sought, the organizer should also consult the Boston University School of Medicine CME Office for guidance with respect to policies and procedures addressing vendor sponsorship. These policies augment Boston University's general policies on conflict of interest. In the case of faculty/clinicians, when these policies are more stringent than University-wide policies on conflict of interest, these policies will apply. Application: This policy applies to (a) all BUSM faculty; and (b) other BUSM employees and trainees who are directly engaged in the provision of clinical services. These groups will be collectively referred to as "faculty/clinicians." Exceptions: As approved by Department Chairs. Procedure: 1. RECEIPT OF GIFTS, GRATUITIES OR OTHER BUSINESS COURTESIES a. Faculty/clinicians may not accept any form of personal gift from industry or industry representatives. b. Food, directly or indirectly funded by industry, may not be provided at BMC or on the BUMC campus. In addition, faculty/clinicians should use discretion in participating in industry-sponsored meals off-campus. Specifically, faculty/clinicians should not facilitate the attendance of trainees at meals off campus sponsored by industry or at educational events off campus sponsored by industry which are not accredited by the ACCME or the American Dental Association Continuing Education Dental Recognition program ("ADA CERP"). 2. CONSULTING a. Consulting arrangements must be reduced to writing and clearly describe the nature of the consulting services and compensation. Compensation must be reasonable, at fair market value and only for specific bona fide services. Reimbursement for reasonable expenses as part of such arrangements is permissible. Such arrangements must comply with any applicable institutional employment contracts, conflict of commitment and conflict of interest policies. b. Faculty/clinicians may not accept more than $500 per hour or $5000 per day from vendors for any consulting service or in the form of honoraria. The terms of the arrangements, services provided, and compensation must be submitted in writing and approved prior to the consultation or service by the faculty/clinician's Department Chair. c. Faculty/clinicians who are simply attending a continuing education program or other instructional activity and who are not speaking or otherwise actively participating or presenting at the meeting, may not accept compensation from vendors either for attending or defraying costs related to attending the meeting. d. Faculty/clinicians may not accept compensation for listening to any sales presentation by an industry representative. e. Faculty/clinicians may not receive any form of compensation for changing a patient's prescription or using a specific device in a patient or for recommending the use of any product or service to a patient. f. Faculty/clinicians may not be paid for attaching their signature to a professional paper, article, or speech unless they have had meaningful input. 3. VENDOR ACCESS AND VENDOR PRODUCT SUPPORT a. As a general rule, industry representatives may not interact with trainees at BMC or on the BUMC campus. Interactions are allowed in limited circumstances, however, when the expertise of representatives is required for instruction in the use of a device and a teaching physician or in the case of non-physician trainee, instructor, is present to supervise the interaction. Page: 2 b. Industry representatives are not allowed in in-patient or out-patient care areas and must visit with faculty/clinicians by appointment only. Under limited circumstances, device vendor representatives may be allowed in patient care areas at the request of a faculty/clinician to facilitate a clinical procedure involving a pertinent device. Under these circumstances, representatives must comply with all BMC patient care requirements and wear appropriate clothing and identification that distinguishes them from employed staff. c. Generally, faculty/clinicians may not accept support from industry for travel and related expenses to review a vendor's products except under limited circumstances. Please consult the Compliance Office in advance of planning such a review. d. Free drug samples may not be accepted by any faculty/clinicians. 4. DEPARTMENT/CORPORATE EDUCATIONAL GRANTS or SCHOLARSHIPS a. Direct support, including support provided to BUSM or a Faculty Practice Plan corporation, of trainee or faculty/clinician salaries, reimbursement for travel expenses or other non-research funding in support of scholarship or training by industry or industry representatives is not allowed. b. Under some circumstances, vendor support of trainee or faculty/clinician salaries or other non-research funding in support of scholarship or training is allowed through a national professional organization or other non-profit entity provided the following conditions are met: 1. The trainee recipient is selected through a peer-review process and both the trainee and the proposed training are endorsed by the department; 2. The trainee and the supporting member or faculty/clinician is not subject to any implicit or explicit quid pro quo (i.e., no strings attached). Specifically, there should be no actual or perceived conflict of interest related to the financial support of trainees; 3. The fellowship or scholarship program must be reviewed and approved by the Department Chair or Vice President; and 4. The funds for the training or scholarship must be paid to a corporation. 5. EDUCATIONAL EVENTS at BMC or BUSM Vendor support for educational events at BMC or BUSM is allowed under the following circumstances: Page: 3 a. All educational activities supported by industry must comply with the ACCME and ADA CERP standards (http://www.accme.org/dir_docs/doc_upload/68b2902a-fb73- 44d1-8725-80a1504e520c_uploaddocument.pdf) regardless of whether or not formal CME credit is awarded; b. All industry funding for medical educational activities must be channeled through the Office of Continuing Medical Education of BUSM; c. The course director is responsible for content, speaker, forum, and management of conflict of interest assisted by the Office of CME; d. Although the industry support can be acknowledged, no marketing, detailing, or other form of vendors advertising should occur on campus in connection with the event; and e. Attendee fees must be used to cover the costs of any food provided. 6. LECTURES or PARTICIPATION in LEGITIMATE CONFERENCES and MEETINGS OFF the BMC or BUMC Campus Clinical meetings and scientific meetings sponsored by professional societies frequently derive a portion of their support from vendors. Such support may give rise to inappropriate vendor influence on the content of the conference or its attendees. Grants for meetings and conferences that originate from the company's marketing division may be particularly problematic. Vendor support generally takes one of two forms and different standards apply in each case. a. First, vendors may partially support meetings run by professional societies. Faculty/clinicians are expected to participate in meetings of professional societies as part of their continuing professional education and professional obligations. Nonetheless, faculty/clinicians should be aware of the potential influence of vendors on these meetings and attentive to the guidelines set forth below in evaluating whether and how to attend or participate in these meetings. b. A second type of meeting or lecture is fully supported by vendors directly or through intermediate educational companies retained by vendors. Faculty/clinicians may actively participate (e.g., giving a lecture, organizing the meeting) in such meetings or lectures only if: 1. Financial support by the vendor is fully disclosed at the meeting by the sponsor. 2. The meeting and lecture's content, including slides and written materials, must be determined by the faculty/clinician. This provision precludes faculty/clinicians from serving in any other relationship with industry that does not allow the faculty/clinician to fully control the content of the lecture. Since providing lectures as a member of a vendor-sponsored Speaker's Bureau usually precludes faculty/clinicians from controlling the content of lectures, faculty/clinicians may not serve on Speaker's Bureaus unless they retain full control of content of all vendors-sponsored lectures. 3. The faculty/clinician delivering a lecture is expected to provide a balanced assessment of therapeutic options, and should promote objective scientific and educational activities and discourse. Importantly, faculty/clinicians should clearly Page: 4 distinguish those uses of medications or devices that are approved by the FDA from those that are not FDA-approved in their lecture. The content of the lecture should be compliant with applicable FDA regulations. 4. The faculty/clinician is not required by the company sponsor to accept advice or services concerning teachers, authors, or other educational matters including content as a condition of the sponsor's contribution of funds or services. 5. The faculty/clinician receives compensation only for the services provided and the compensation is reasonable and reflects fair market rates. 6. Time spent in preparing and delivering the lectures does not impair the faculty/clinician's ability to fulfill departmental responsibilities. 7. The faculty/clinician delivering the lecture explicitly describes all his or her related financial interests (past, existing, or planned) to the audience. 8. The faculty/clinician makes clear to the audience that the content of the lecture reflects the views of the clinician and not those of BMC or BUSM. 9. Faculty/clinicians should not facilitate the participation of trainees in vendor- sponsored events that fail to comply with these standards. 7. DISCLOSURE of RELATIONSHIPS with VENDORS a. Faculty/clinicians must fully disclose all relationships with vendors on an annual basis through the reporting mechanisms of Boston University School of Medicine and Boston Medical Center. b. Faculty/clinicians engaged in speaking or consulting that is compensated by vendors must have approval from the Department Chair prior to providing the service. If the Department Chair has personal financial interest in the same entity as that proposed for the member, the Department Chair should recuse himself or herself and the approval should be granted by the Dean of BUSM. c. Faculty/clinicians must disclose all of their related financial interests, including past, existing or expected interests (e.g., grants and sponsored research, compensation from consulting, speaker's bureaus, advisory boards; investments and ownership interests) to journal editors in manuscripts submitted for publication, and audiences at lectures or presentations. d. Faculty/clinicians must disclose their actual and potential conflicts of interest related to any institutional deliberations and generally may not participate in deliberations in which he or she has an actual or potential conflict of interest. See Boston University Conflict of Interest Policy (http://www.bu.edu/ethics/conflict.pdf) and Boston Medical Center Conflict of Interest Policy (No. 9.4). e. Faculty/clinicians with supervisory responsibilities for trainees must ensure that the instructor's conflict or potential conflict of interest does not affect or appear to affect his or her supervision of the activities or responsibilities of the trainee or staff member. Page: 5 8. ENFORCEMENT In the case of members of the BMC Medical Dental Staff, Department Chairs will be responsible for reporting violations of the policies to the Chief Compliance Officer of Boston Medical Center, Chief Medical Officer of BMC, and to the Provost of BUMC. Members who violate the aforementioned policies will be subject to sanctions in accordance with their Faculty Practice Plan Agreement and the Boston University Faculty Handbook. These sanctions may include disciplinary actions, financial penalties, and possibly termination for repeat violations of the policy described herein. Enforcement of these provisions and sanctions against individual faculty members will be overseen by a standing committee appointed by the President and CEO of Boston Medical Center and Provost of BUMC, and comprised of representatives from Boston Medical Center and Boston University. In addition, companies whose representatives violate the aforementioned policies will also be referred to the Chief Compliance Officer and may be subject to sanctions by BMC and/or BU. For example, companies or their vendors who violate two of these policies within a one year period may be denied access to clinical staff at Boston University School of Medicine and faculty/clinicians and members at Boston Medical Center for a six month period. Companies with three violations within two years may be denied access for a two year period. This policy is not intended to address all possible situations involving financial relationships between BUSM faculty/clinicians and vendors. If anyone has a question concerning the interpretation or applicability to a particular circumstance of any of the laws, regulations or standards referred to in this policy, he or she should contact the Department Chair, Vice President or Chief Compliance Officer. Anyone who is in doubt as to the propriety or legality of any course of action must consult with the Chief Compliance Officer prior to taking action. If anyone is aware of any actual or threatened violation of this policy, or suspects a violation of this policy has occurred, he or she must report the situation to the Chief Compliance Officer. Responsibility: Department Chairs, Provost of BUMC, BMC Chief Compliance Officer, BMC Chief Medical Officer.
% BW for TBW, ECF, Plasma
TBW = 58% ECF = 17% Plasma = 4%
Association Between Academic Medical Center Pharmaceutical Detailing Policies and Physician Prescribing
Supplemental content CME Quiz at jamanetwork.com/learning Author Affiliations: University of California, Los Angeles (Larkin); University of California, San Diego (Ang); Austrian Institute of Technology, Seibersdorf, Austria (Steinhart); Johannes Kepler University, Linz, Austria (Steinhart); Williams College, Williamstown, Massachusetts (Chao); Carnegie Mellon University, Pittsburgh, Pennsylvania (Patterson, Loewenstein); Cornell University, Ithaca, New York (Sah); New York University Langone School of Medicine, New York, New York (Wu); National Institute of Mental Health, Bethesda, Maryland (Schoenbaum); CVS Caremark, Woonsocket, Rhode Island (Hutchins, Brennan). Corresponding Author: Ian Larkin, PhD, Anderson School of Management, University of California, 110 Westwood Plaza, Los Angeles, CA 90095 ([email protected]). (Reprinted) 1785 Downloaded From: r on 05/06/2017 IMPORTANCE In an effort to regulate physician conflicts of interest, some US academic medical centers (AMCs) enacted policies restricting pharmaceutical representative sales visits to physicians (known as detailing) between 2006 and 2012. Little is known about the effect of these policies on physician prescribing. OBJECTIVE ToanalyzetheassociationbetweendetailingpoliciesenactedatAMCsand physician prescribing of actively detailed and not detailed drugs. DESIGN,SETTING,ANDPARTICIPANTS Thestudyusedadifference-in-differencesmultivariable regression analysis to compare changes in prescribing by physicians before and after implementation of detailing policies at AMCs in 5 states (California, Illinois, Massachusetts, Pennsylvania, and New York) that made up the intervention group with changes in prescribing by a matched control group of similar physicians not subject to a detailing policy. EXPOSURES Academicmedicalcenterimplementationofpoliciesregulatingpharmaceutical salesperson visits to attending physicians. MAINOUTCOMESANDMEASURES Themonthlywithin-drugclassmarketshareof prescriptions written by an individual physician for detailed and nondetailed drugs in 8 drug classes (lipid-lowering drugs, gastroesophageal reflux disease drugs, diabetes drugs, antihypertensive drugs, hypnotic drugs approved for the treatment of insomnia [sleep aids], attention-deficit/hyperactivity disorder drugs, antidepressant drugs, and antipsychotic drugs) comparing the 10- to 36-month period before implementation of the detailing policies with the 12- to 36-month period after implementation, depending on data availability. RESULTS Theanalysisincluded16121483prescriptionswrittenbetweenJanuary2006and June 2012 by 2126 attending physicians at the 19 intervention group AMCs and by 24 593 matched control group physicians. The sample mean market share at the physician-drug-month level for detailed and nondetailed drugs prior to enactment of policies was 19.3% and 14.2%, respectively. Exposure to an AMC detailing policy was associated with a decrease in the market share of detailed drugs of 1.67 percentage points (95% CI, −2.18 to −1.18 percentage points; P < .001) and an increase in the market share of nondetailed drugs of 0.84 percentage points (95% CI, 0.54 to 1.14 percentage points; P < .001). Associations were statistically significant for 6 of 8 study drug classes for detailed drugs (lipid-lowering drugs, gastroesophageal reflux disease drugs, antihypertensive drugs, sleep aids, attention-deficit/hyperactivity disorder drugs, and antidepressant drugs) and for 9 of the 19 AMCs that implemented policies. Eleven of the 19 AMCs regulated salesperson gifts to physicians, restricted salesperson access to facilities, and incorporated explicit enforcement mechanisms. For 8 of these 11 AMCs, there was a significant change in prescribing. In contrast, there was a significant change at only 1 of 8 AMCs that did not enact policies in all 3 areas. CONCLUSIONSANDRELEVANCE ImplementationofpoliciesatAMCsthatrestricted pharmaceutical detailing between 2006 and 2012 was associated with modest but significant reductions in prescribing of detailed drugs across 6 of 8 major drug classes; however, changes were not seen in all of the AMCs that enacted policies.
Mechanisms of opioid clearance
**depends on person's gene and metabolism!! Always titrate! *Hepatic:* Fentanyl: CYP3A4,5 Codeine: CYP2D6 (10% of codeine turns into morphine via 2D6; european w/ dec. 2D6 gene = less analgesic effect from codeine; north african = opposite) Morphine: Glucuronidation, Demethylation *Extra-hepatic* Remifentanil: esterases (in muscles; lots of types of esterases, hence super rapid clearance of this drug
Hurler Syndrome
*MPS I = Hurlers Syndrome* missing enzyme: *alpha-L-iduronidase* accum material: dermatan sulfate, heparin sulfate tissues involved = connective tissues - RES, endothelial cells, smooth muscle cells, fibroblasts (balloon cells) clinical: - hepatosplenomegaly, skeletal deformities, valvular lesions, subendothelial arterial deposits, myocardial infarction
intraventricular and germinal matrix hemorrhage
- baby brain ~ vanilla pudding - predisposeod to intraventricular and germinal matrix hemorrhage if: --> premie --> hypoxia --> breach clinical symptoms --> apnea --> lethargy --> poor muscle tone --> seizures
causes of patient variability in apparent Vd
- body weight (directly prop. to Vd) - body composition (% fat, % fluid compartments) --e.g. obese = lipophilic drug has more Vd; other drug has less (because BW relative to TBWater is >>) - concentrations of plasma and tissue binding sites (e.g. how much albumin)
mechanism of heat stroke
- due to high ambient temp/humidity --> cessation of sweating; can't cool off body - advanced age, physical stress are major risk factors prolonged core temp > 40* F --> peripheral vasodilation --> reduced blood flow to brain/heart --> confusion/coma/death
Mechanism of how glucocorticoids change gene expression
- interaction w/ cytosolic hGR alpha - translocation into nucleus - binding to GRE (glucocorticoid response element) - interaction of GR (glucocorticoid receptor) with transcriptional regulators - change in gene expression
Diseases/conditions associated to prematurity
- neonatal respiratory distress syndrome (hyaline membrane disease) - necrotizing enterocolitis - sepsis - intraventricular and germinal matrix hemorrhage - long-term complications, including developmental delay
fluid-phase endocytosis
- nonspecific (FC region) process driven by *concentration* mAb on the extracellular side - doesn't require ligand binding to cell surface - responsible for mAb entering into endothelial cells and peripheral tissues aka pinocytosis
toxicity & side effects of a antagonists
- postural hypotension (due to inhibition of a-mediated vasoconstruction) - reflex effects arising from postural hypotension (less sevre w/ a1 selective agents such as prazosin) - reflex tachycardia - MI - salt and water retention in kidneys + peripheral edema (due to reflex B1 stimulation of kidney RAAS) - GI stimulation (abdominal pain, nausea, exacerbation of peptic ulcer) - inhibition of ejaculation
Risk factors for prematurity
- preterm premature rupture of placental membranes (PPROM) - intrauterine infection - uterine, cervical, and placental structural abnormalities - multiple gestation (twin pregnancy)
Pre-analytic variables for lab testing
- proper patient identification and specimen labeling - time of day specimen is collected (i.e. fasting state for glucose and lipid testing, peak and trough sampling for therapeutic drug monitoring) - right tube for the given test - quality of the specimen: ---> minimize hemolysis ---> adequate mixing of anticoag blood tests ---> sometimes more is better, esp for microbio ---> *not collecting blood downstream of infusion site* ---> collecting blood for coag tests that's free of line anticoagulants (i.e. flushing lines kept open w/ heparin) - minimizing transport time of specimen or time between draw and receipt in lab
Renal toxicity from NSAIDs
- sodium retention and edema (greater risk in pts w/ renal and CV disease) - papillary necrosis and interstitial nephritis ("analgesic nephropathy"; caused by acetaminophen and NSAIDs
Opioid cardiovascular effects & tx of MI
- vasodilation (centrally mediated, venous and arterial) - bradycardia - *no* important effects on: myocardial contractility, vascular response to catecholamines, sympathetic reflexes Tx of MI? - opioids are great to help with everything MI, but depends on patient's blood pressure! - normal BP = use opioids - low BP = don't (brady + vasodilation would worsen) --> need to use a1 agonist (phenylephrine) first, then morphine
Steps of cytokine receptor function (aka "kinase-linked receptors")
1. Ligand binds 2. Dimerization of rec.protein w/ another rec. that has just bound the same type of ligand 3. Autophosphorylation of intracellular domain (activates it) 4. Cascade of effects (carries) 5. Affects gene transcription in nucleus Slow (hours) because relies on gene transcription
4 ways opioids cause pain relief
1. Limbic System - pain doesn't bother person as much; source of euphoria; depends on person 2. Descending modulation - via locus cereleus and raphe nuclei; decreases descending pain info 3. Dorsal Horn Substantial Gelatinosa - opioid Receptor cause dec. calcium conductance - result = inhibit substance P and NT transmission to postsynaptic neuron - at post-synaptic neuron, u receptors cause inc. gK+ IPSP (inhibitory post synaptic potential) - result = dec. pain transmission - also Enk 1 and Enk 2 modulate at dorsal horn - dec. effect of substance P (post syn neuron desensitization to subst. P) 4. Perhaps peripheral effect w/ inflammation (minimal impact though)
4. Identifythestructureandfunctionofgranulationtissueandtherole cytokines and growth factors have in its formation
1. Inflammation - Layer I Necrosis and Acute Inflammatory Exudate The elements involved in the acute inflammatory process are discussed in a separate lecture. The purpose of acute inflammation is to contain the injury and initiate the reparative process; this latter is achieved by the digestion and removal of tissue debris and the production of cytokines and growth factors by the participating inflammatory cells, particularly macrophages/monocytes. The acute inflammatory process is reflected in the superficial layer of the chronic ulcer by fibrin and acute inflammatory exudates. Deep to this are remnants of necrotic tissue, smooth muscle in this example, mixed with inflammatory cells and scavenging macrophages. 2. Cell Proliferation and Migration - Layer II Granulation Tissue Cell proliferation and migration of epithelium is evident in the edges of the epithelial defect as a monolayer of epithelial cells gradually insinuates itself deep to the resolving inflammatory exudates. In layer II the ingrowth of endothelial cells and fibroblasts, macrophages and attendant extracellular matrix forms a specialized reparative stroma called granulation tissue. This tissue is essentially the "organ of repair" that ultimately produces mature scar tissue (layer IV). The molecular agents that are mainly responsible for the formation and functioning of granulation tissue are growth factors and cytokines. To sustain itself this intensively productive tissue forms new vessels. This process is called Angiogenesis and is driven by multiple growth factors particularly VEGF which is stimulated, in turn, by other growth factors such as TGF- and PDGF. Angiopoietins (Ang 1 and 2) stabilize the vascular tubes that are formed by recruiting periendothelial cells. The source of the new vessels is capillary budding from the contiguous vascular networks but endothelial precursor cells (EPCs) from the bone marrow may also contribute. The following is the sequence of steps in angiogenesis derived from pre-existing vessels: 1) degradation of basement membrane; 2) migration of endothelial cells; 3) proliferation of endothelial cells; 4) maturation and tube formation Growth factors Growth factors are polypeptides (typically) that signal cells to proliferate, migrate and differentiate. They may act exclusively on a particular cell type or affect a variety of cell types in a tissue. They may reach the target cells from a remote site transported by the blood stream (endocrine signaling), or diffuse from adjacent cells (paracrine signaling - a good example is FGF derived from macrophages causing fibroblasts to proliferate in granulation tissue), or finally they may act on the very cells that produce them (autocrine signaling - TGF-a & hepatocyte regeneration). They exert their effect on target cells by binding to specific receptors which in turn signal transcription factors that affect cell proliferation, migration and protein synthesis. The following are examples of growth factors that are important in the repair process: EGF/TGF- These related polypeptide growth factors bind to EGFR cell membrane receptors which generate a signal with tyrosine kinase that induces a wide variety of cells including epithelial cells and fibroblasts to divide. In healing skin wounds it is produced by keratinocytes and macrophages. PDGF is a dimer with A and B chains; each molecule binds to 2 membrane receptors and respectively. PDGF is stored in platelet alpha granules and released on activation; it is also produced by a variety of other cells including activated macrophages, smooth muscle cells, endothelial cells and some tumor cells. Among its effects are the induction of migration and proliferation of fibroblasts and endothelial cells FGFs are produced by a variety of cells and are recognized by a family of cell surface receptors that have intrinsic protein kinase activity. FGFs induce macrophage, fibroblast and endothelial cell migration and also induce angiogenesis. VEGF is a family of growth factors essential to new blood vessel formation or angiogenesis. VEGF also induces increased vascular permeability. TGF- refers to one of a family of homodimeric proteins (-1,- 2,- 3 and BMP) produced by platelets, endothelial cells, lymphocytes, macrophages and other cells. It interacts with a cell surface receptors with serine/threonine kinase activity and activates by phosphorylation cytoplasmic transcription factors called SMADs. TGF- can function both as a growth inhibitory and stimulatory agent (pleiotropic) depending on the tissue environment. It inhibits epithelial proliferation and stimulates fibroblast chemotaxis and production of collagen and fibronectin by cells. It is considered an important factor in the development of fibrosis in many chronic inflammatory conditions.
toxicity mechanisms for tobacco
1. Nicotine (an alkaloid) --> addictive - nicotinic ACh recpetor in brain --> inc. catecholamines --> inc. HR, BP, CO (stimulant, plus relaxing) 2. Polycyclic hydrocarbons nitrosamines - carcinogens 3. many smoke components (tar, formaldehyde, nitric oxides) --> inflammation, mucus production (bronchitis), neutrophil recruitment to lung increases; elastase inc. (thus elasticity dec.); tissue injury --> emphysema
MCQs lecture
1. Norepinephrine acts on beta-1 receptors to INCREASE heart rate. 2. NE acts on alpha-1 receptors to INCREASE blood pressure. 3. NE causes an increase in BP and decrease in HR if via IV; if muscarinic receptors are blocked then NE increases both BP (a1) and HR(b1). 4. Propranolol is a B1 antagonist/blocker alone causes no channge in BP (a1) and decrease in HR. 5. NE is a a1/b1 agonist alone causes rise in BP and baroreflex drop in HR. Miuscarinic blockade prevents M2-mediated baroreflex so the direct effect of NE is to increase HR via B1 and increase Bp via B1. 6.Isoproterenol is a B1 agonist and causes an increase in HR via B1. M2 is from the heart, M2 is from exocrine glands. 7. Adrenergic agonists can be used a) Phenylephrine: Nasal decongestants (a1; prevents dilation and engorgement of nasal mucosa blood vessels) b) Epinephrine a1 vasoconstriction reduces drug absorption to increase local anesthetic action c) Epinephrine a1/b1 resuscitation after cardiac arrest d) a1 vasoconstriction antidote to hypotensive agent overdose e) a1 vasoconstriction with fluids maintain blood pressure in spinal damage or anesthesia f) DA a1 restorate blood pressure after cariogenic shock g) Clonidine: a2 treat hypertension h) Phenylepinephrine a1 dilation for mydriasis i) a2/B1 reduce fluid generation for glaucoma j) a2 increases fluid outflow for glaucoma k) Allergy Asthma b2- Asthma bronchial smooth muscle relaxation l) a1-b1-b2 anaphylactic shock (b2 relaxes airway smoke muscle and inhibits mast cell release of anaphyslasic mediators, a1 maintains MAP) o) b2 relaxes uterine SM to delay premature labor q) a2 treats opioid withdrawals w) ADD via amphetamine methylphenidate z) Anaphylactic shock: g allergic reaction caused by severe hypersensitivity to insect venoms (e.g., bee), certain foods (e.g., peanuts), and certain drugs (especially penicillin). Acute treatment via epinephrine for a/b a1: vasoconstriction to increase BP and prevent glottal edema b1: increases CO/HR to help rise BP b2: increases bronchodilation -Albuterol most likely to induce bronchial dilation -NE: no B2 selectivity -Phenylephrine - a1 agonist vasoconstrictor -Clonidine a2 agonist - inhibits sympathetic sedative -Phenylephrine is a a1 agonist vasoconstrictor applying to nasal mucosal to induce vasoconstriction a1 side affects: vasoconstriction, ischemia, hypertensive reactions, cerebral hemorrhage, rebound nasal congestion a2 agonist: withdrawal syndrome b1: tachycardia, myocardial schema, cardiac ventricular arrhythmias b2: increased asthma exacerbation (b2 helps bronchodilate), hyperglycemia (b2 liver glycogenolysis) -Adrenergic agonists cause CNS stimulation side affect -Indirect Sympathomimetics will increase the availability of endogenous adrenergic transmitters: Dopamine(octopamine), amphetamine, methylphenidate, and cocain. -Indirectly acting adrenergic agonists: tyramine, ephedrine, amphetamine increase NE release leading to more postsynaptic action. Tyamine in food, cheese, red wine, cute: tyramine degraded by MAO, if MAO is inhibited (Parkinson's): hypertensive crisis by cheese/red Wien due to release of NE on b1, tyramine pressor response BP increases by 30mmHg. Longterm: tyramine converts to octopamine via dopamine b-hydroxylase and stores to replace NE which has little action so long term MAO therapy can impair sympathetic nervous system. -Indirect adrenergic agonists that increase NE include dextroamphetamine, methylphenidate via ADHD (NE DA release + a/b1 stimulate), ephedrine (release NE + a/b in nutritional supplements FDA regulated), pseudoephedrine used for decongestants. -Tricyclic antidepressants, coins (prevent NE DA reuptake) are central active leading to fatal CV VNS events. -Direct neuronal blockers: Resperine depletes NE stores by inhibits VMAT (inhibiting vesicular monoamine transport) in synapse, so no NE release, NE killed by intraneuronal MAO (monoanimine oxidase). Adrenergic Antagonists:AcH M on heart and SM, slow HR, no b1/b2/1 response. A1 Antagonist: The blockade or reduction of epinephrine and norepinephrine binding on alpha adrenoreceptors reduce arteriolar resistance and increase venous capacitance causes a reflex increase in heart rate. Depending on plasma concentration they may cause orthostatic hypotension. Alpha-1 blockers may decrease LDL and triglycerides and increase HDL. A2 Antagonist: Mechanistically, α2-blockers significantly increase adrenergic, dopaminergic and serotonergic neurotransmitters, and induce insulin secretion and decreases blood sugar levels. TCA. Phentoalamine a1/a2 a1/a2 irreversible: phenoxybenzamine/ethylemimonium a1 only: prazosin a2 only: Yohimbine Therapy: treat hypertension, treat pheochromocytoma, Raynaud reduce digital vasospasm, treat heart failure by lowering vascular resistance, treat BPH, decrease bladder muscle tone to make peeing easier, antidote to a-1 agonist vasocontsitiron. Side Effects: Postural hypotension (inhibit a-mediated vasoconstriction): reflex tachycardia, myocardial ischemia due to more O2 demand, B1 renal RAS reflex salt/water retention, peripheral edema, GI stimulation pain, inhibition of ejaculation. Beta Adrenergic Antagonists B1/B2/CNS: Propranolol (HR + BP) B1 only: Metoprolol (HR+) B1/B2/a1: Carbedilol B1/B2: Pindolol B1 short: Esmolol B1/B2/a1: Labetalol B1/B2: Propranalol B1: Atenolol Beta antagonists are used for Treatment of cardiac arrhythmias, reduce mortality after MI, shock to keep CO/perfusion, heart failure (carvedilol increases CO), hypertension (reduce CO inhibit renin), treatment of angina (to control O2 demand), treartment of hyperthyroidism (propranolol), reduce anxiety, migraine prophylaxis, OPEN ANGLE galucome. Timolol has a protective effect after MI. Carvedilol has a protective affect in heart failure. Metoprolol is less effective in protecting in CHF mortality. Toxic side affects of B-antagonists include bronchoconstirction, bradycardia, withdrawal increases angina, fatigue, cold extremities, epinephrine vasoconstriction, CHF increase via inhibition of adrenergic compensation, predispose new onset diabetes., -The reflex change in heart rate associated with administration of a low dose of isoproterenol could be blocked by administration of which one of the following agents? Propranol: Isoproterenol is a B1/B2 agonist causing vasodilation/tachycardia; effects can be blocked by a nonselective b-antagonist propanol. Atropine is a muscarinin antagonist. Prazosin is a a-1 antagonist. Physostigmine is a reversible cholinesterase inhibitor (increase Act) Apoptosis in liver lobule apaototic body is called councilman body. Necrosis: Unprogrammed/chaotic Numerous cells/field of injury Always pathological Cell membranes disrupted Inflammatory response Apopstosis: Programmed/controlled Scattered single cells Physiological or Pathological Cell membranes intact No inflammatory response Physiologic causes of apoptosis: Organogenesis - developmental involution and metamorphosis during embryogenesis. • Hormone-dependent involution e.g. the menstrual cycle and regression of the lactating breast after weaning. • Cell deletion in proliferating cell populations e.g. the crypts of the colon, granulocytosis Pathologic causes of apoptosis: Pathologic • Viral diseases, particularly viral hepatitis. • Pathologic atrophy following duct obstruction such as occurs in salivary gland, pancreas and kidney. • Cell death in some tumors • Cell death in response to DNA injury drugs • Cell death in response to misfolded proteins in the endoplasmic reticulum. Methods of Apoptosis: GF withdrawal, DNA damage, ER stress, Death Receptor Extrinsic Fas, TNF receptor, Apoptotic body results for phagocytosis. BCL2 increases BAX BAK and cytocrhrome C so caspase then apaostisis cell death. -Alzheimers disease cerebral generalized atrophy. -Drug (MMF) induced Apoptosis Colonic glands -Necroptosis (programmed necrosis): begins by ligation of TNFR1 by TNF = RIP1/RIp3 -> decreased mictochondrial ATP and higher ROS, membrane cell leakage. -Steatohepatitis Mallory's Hyaline.
4 drugs that block enzymes + mechanisms
1. Penicillin (B lactam antibiotic; blocks bacterial transpeptidase --> no cell wall construction) 2. Zidovudine (blocks HIV's reverse transcriptase) 3. Physostigmine (AChE inhibitor - result = more parasymp transmission) 4. Disulfiram (blocks aldehyde DHO; anti-alcohol agent for addiction)
layers in ulcer
1. top layer = fibrinopurulent exudate (fibrin + PMNs) 2. middle layer = granulation tissue capillary network in matrix of fibroconnective tissue and inflammatory cells (angiogenesis) 3. bottom layer = scar tissue (collagen) - sometimes can have trapped nerve fiber in collagen and that causes painful scar
5 vasodilators (part of acute inflammation)
1. vasoactive amines (histamine, serotonin) 2. COX products from arachidonic acid (prostacyclin (PGI2), PGE2, PGD2) 3. Nitric Oxide (NO) 4. Bradykinin (<-- the rest are cell derived; this one is plasma-derived (biologically active protein) 5. Platelet activating factor (PAF) (causes dilation @ low conc, but constriction @ high!) mnemonic: VCNBP vasodilation can never be perfect
Describe the factors contributing to the escalating expenditures for prescription drugs • Distinguish the difference between the price of a drug and the cost of a drug • Describe the role of pharmacoeconomic analyses • Describe the impact of the epidemic of adverse drug events/drug misadventures in the USA • Describe methods to manage drug expenses: • Discuss drug formulary systems • Define generic equivalence and therapeutic equivalence
1.1 Price factors: 1.1.1 Research and Development Costs - The costs of bringing a drug to the market 1.1.2 Advertising and Marketing Costs 1.1.2.1 Direct-to-Consumer Advertising 1.2 Utilization factors: 1.2.1 Escalating use of drugs for more patients, more conditions 1.2.3 Product mix - choice of drug to treat the condition (e.g., new brand name drugs are more expensive) 2. Price - (Sum of money asked or given) 2.1 Average Wholesale Price (AWP) - Industry-established "list price" 2.2 Discounts are offered for volume purchases or by class-of-trade (e.g., nonprofit vs profit). Group Purchasing Organizations negotiate price for a group of unaffiliated businesses. 3. Cost - (Value of resources consumed) 3.1 The cost of drug therapy is comprised of the following: 3.1.1 Acquisition cost of the drug = price to the purchaser 3.1.2 Preparation and administration costs = cost of labor and materials required to dispense and administer drugs (i.e., pharmacy and nursing costs) 3.1.3 Monitoring costs = laboratory studies, follow-up visits 3.1.4 Adverse Events costs = toxicity, complications, failures 3.2 The cost is offset by the benefit, or positive therapeutic outcome 4. Pharmacoeconomics - Identifying, measuring, and comparing the costs, risks, and benefits of programs, services, or therapies and determining which alternative produces the best health outcome for the resources invested. 4.1 Cost Minimization - comparison of costs of similar products that have equivalent outcomes 4.2 Cost Effectiveness - comparison of total costs of therapy relative to the clinical outcomes gained; used to compare treatments that have different efficacy rates, but similar treatment objectives (e.g., Antibiotic A vs Antibiotic B for sinusitis). The outcome measure is expressed as a natural unit (e.g., cure rate or mmHg reduced for antihypertensives) 4.3 Cost Benefit - similar to cost-effectiveness, however outcome measure is expressed in dollars (e.g., dollar value of a life saved). Allows comparison of treatments with entirely different objectives (e.g., vaccination program vs. HIV drug treatment program) 4.4 Cost Utility - similar to cost effectiveness, however the outcome measure (expressed in natural units) is adjusted for the quality of health gained (e.g., quality adjusted life years) 5. Adverse Drug Event (Medication Errors and Adverse Drug Reactions) 5.1 Medication Error — An error that occurs at any stage in the medication use process (prescribing, dispensing, administration, monitoring, documenting). PREVENTABLE 5.2 Adverse Drug Reaction — An unintended reaction (not a side effect) to a drug used in a proper manner. NON-PREVENTABLE 5.3 Impact — Incidence / Morbidity / Mortality / Costs — Studies estimate that the burden of all adverse drug events costs the US healthcare system tens of billions of dollars annually, secondary to: treatment failures and disease progression; increased hospital and emergency room admissions; additional prescriptions; and deaths. 5.3.1 Non-adherence and non-persistence - contribution to poor efficacy and increased costs attributable to failure to take medication as frequently as intended and for the duration intended.
2nd generation anti histamines
2nd = 1970s; loratidine --> no effect on histamine induced smooth muscle contraction - higher selectivity for H1 relative to other receptors - minimal antimuscarinic effects (xerostomia); sometimes supplement with phenoephrine or pseudoephedrine to help with nasal vasoconstriction/other ways that +symp makes you feel good - markedly lower incidence of sedation (*charged carboxylate residue* limits access to CNS)
Drugs A, B, and C were tested for their capacity to competitively antagonize the epinephrine-induced increase in heart rate, for their capacity to competitively antagonize epinephrine-induced relaxation of bronchial smooth muscle, and for their capacity to competitively antagonize epinephrine-induced contraction of arterial smooth muscle. KB's were determined for all three drugs. Results were as follows: A. Drug C would likely be safer than Drug B for treatment of benign prostatic hyperplasia (BPH) in a patient with asthma. B. *Drug B would probably be less likely than drug A to cause bronchoconstriction when used for treatment of congestive heart failure in a patient with chronic obstructive pulmonary disease (COPD). C. The receptors blocked by drugs B and C in bronchial smooth muscle are different. D. Drug B would be more likely than drug C to produce postural hypotension as a side effect when used as treatment for congestive heart failure. E. If norepinephrine were used as an agonist instead of epinephrine, drug C would probably exhibit lower potency (greater KB) for inhibition of contraction of arterial smooth muscle.
31. Which type of physiological receptor typically shows the fastest response time? A. G-protein coupled receptors B. Ligand gated ion channels * C. Intracellular hormone receptors x D. Growth factor receptors x E. Cytokine receptors Which of the following hypotheses is consistent with this result? A. Drug X is a beta 2 agonist B. Drug X is a noncompetitive antagonist x C. Drug X is an inverse agonist x D. Drug X is a partial agonist * E. Drug X is a muscarinic agonist , partial agonists are drugs that bind to and activate a given receptor, but have only partial efficacy at the receptor relative to a full agonist.
66. BUSM policy regarding interactions with representatives of the pharmaceutical industry prohibits: Free drug samples for distribution by the hospital pharmacy *Gifts to physicians Physician attendance at CME conferences supported by industry Payment for consulting services by a physician Visits to a physician's office by appointment
65. Which of the following can be expected to have the most rapid onset of analgesic effect after IV administration, in part because it is not a pro-drug and is extremely lipophilic? Morphine-6-glucuronide: Morphine 6-glucuronide (M6G) is an active metabolite of morphine that could be used as a drug, but its hydrolysis into morphine remains controversial. *Fentanyl: Fentanyl, also known as fentanil, is an opioid pain medication with a rapid onset and short duration of action. It is a potent agonist of μ-opioid receptors. Reservoir: The drug is stored in a single compartment from which it migrates through a rate-controlling membrane to the skin surface. [Examples: Duragesic® (fentanyl, for the management of chronic pain) U AGONIST Naloxone It is a competitive antagonist at mu, delta, and kappa opioid receptors. .... Recently, naloxone has been shown to bind all three opioid receptors (mu, kappa and ... Morphine: Hypotension: due to drug-induced release from mast cells (e.g. morphine); Histamine Antagonists; Morphine (u/k agonist); Opioid sturcture is related to morphine which includes 5 rings, 3-/6- hyroxyl group (phenolic/alchoholic), piperidine ring w N-methyl group, quaternary carbon at C13. Morphine is optically active; only the levorotatory isomer is an analgesic. Simple modifications of morphine make other active analgesics Codeine: Codeine: morphine O-methylated at position 3/ Heroin is morphine O-acetlyated at position 3 and 6. Replacing the N-methyl with larger group (allyl, cyclopropyl, cyclobutyl,) produces a copound with opioid ANTAGONIST properties. N-allyl derivatives of morphine (oxymorphone)and nalorphine (naloxone). Meperidine (Demerol) is a synthetic opioid with only fragments of the morphine structure.
Selectivity of aspiring (dosage & resultant effect)
81 mg/day = baby aspirin once/day; anti-platelet, CV event prophylaxis 650-1000 mg = analgesia 3g/day = anti-inflammatory (can hurt stomach, ulcers & GI bleeds)
arachidonic acid metabolites
=> arachidonic acid (20 carbon polyunsaturated fat w/ phospholipids in cell mem) metabolites (COX products): - prostaglandins - leukotrienes - lipoxins
what things determine the clinical significance of a thermal burn?
> depth of burn > percent of body surface involved > internal injuries from inhalation of hot & toxic fumes > promptness and efficacy of therapy
7. Would either X or Y be preferable to the other, as less likely to cause orthostatic (postural) hypotension if it were administered to patients? Explain your answer.
A noncompetitive (or irreversible competitive) antagonist of norepinephrine such as Y would be more likely to cause orthostatic hypotension than would a reversible competitive antagonist such as X, because increased release of norepinephrine upon reflex sympathetic firing to the vasculature could not overcome the effect of the noncompetitive antagonist.
Which of the following is an appropriate conclusion regarding the association between salicylates and Reye's syndrome?
All three of these biases could have influenced this study. The selection mechanism is not described here, but case-control studies provide an opportunity for selection bias. Recall bias is a distinct possibility, because the mothers of children with Reye's syndrome are more likely to have thought about and remembered the medications that they gave their children. If the interviewers were not blinded to the outcome, they could ask questions of the parents in a different way among those affected by Reye's syndrome compared with parents of those not affected.
Analytic phase:
Analytic phase: The laboratory runs the sample and generates a result. Results can be quantitative or qualitative. Most lab tests are quantitative. Also most lab tests are resulted by the medical technologist without review by the pathologist. Some lab tests, particularly the qualitative ones, are interpreted by the pathologist such as protein electrophoresis with or without immunofixation, antinuclear antibody (ANA) testing, some peripheral smears or body fluid cytospins in which a medical technologist is unsure or concerned about, bone marrow aspirate smears, flow cytometry, abnormal type and screens, transfusion reactions, etc.
Do you think X and Y have the same mechanism of action? Why, or why not?
As antagonists of norepinephrine, X and Y do not have the same mechanism of action because interpretation of the dose-effect curves indicates that X behaves as a reversible competitive antagonist, whereas Y is a noncompetitive (or irreversible competitive) antagonist. X is illustrative of the properties of the prototype drugs phentolamine and prazosin, competitive alpha receptor antagonists.
Relate the therapeutic and toxic effects of prototypic cholinergic agonists and antagonists to their actions on specific receptors.
B. Muscarinic Acetylcholine Receptors 1. G-proteincoupled 2. 5subtypes(M1-M5) a) M1, M3, M5: The odd- numbered subtypes couple through activation of phospholipase C (2nd messengers inositol triphosphate (IP3) and diacylglycerol). M3 ("glandular") muscarinic receptors are predominantly responsible for glandular secretion, nitric oxide (NO) release in vasculature, bronchial smooth muscle contraction, bladder contraction & sphincter relaxation b) M2, M4 muscarinic receptors: The even-numbered subtypes couple through inhibition of adenyl cyclase, reducing 2nd messenger cAMP. In addition, they also produce Ca2+ channel inhibition and K+ channel activation mediated by the G-protein -subunit. Activation of M2 ("cardiac") receptors decreases heart rate and contractility. 3. Direct-actingAgonists a) Nonselective(nicotinic+muscarinic) (1) Acetylcholine (2) Carbamylcholine b) Muscarinic-selective (1) Pilocarpine (2) Muscarine (3) Bethanechol c) Physiological effects of muscarinic receptor activation (1) Contractionofpupil(miosis)andciliarymuscle(accommodation) (2) Decreased heart rate (3) Vasodilation, mediated by release of EDRF (nitric oxide) by vascular endothelium (4) Bronchial smooth muscle contraction (5) Gastric acid secretion (6) IncreasedGItoneandperistalsis (7) Bladder contraction and sphincter relaxation (8) Glandular secretion (9) Penileerection d) Therapeutic uses (1) Promote bladder emptying (bethanechol) (2) Stimulation of GI activity in GI disorders (bethanechol) (3) Treatmentofxerostomia(drymouth) (4) Contraction of pupil (miosis) for ophthamlogical surgery (acetylcholine, carbachol) (5) Reduce intraocular pressure in open-angle glaucoma by contracting ciliary body, facilitating drainage of aqueous humor (pilocarpine, carbachol) e) Muscarinic toxicity ("SLUDGE") (1) Salivation (2) Lacrimation (3) Urination (4) Diarrhea (5) GIupset (6) Emesis (7) Bronchoconstriction/bronchospasm (muscarinic agonists are contraindicated in asthma) 4. Muscarinic antagonists a) Belladonna alkaloids (1) Atropine(littleCNSeffectatmoderatedoses) (2) Scopolamine(CNSdepressioninadditiontoperipheralautonomic effects) b) Pirenzepine (1) Relatively selective for M1 receptors in cerebral cortex and sympathetic ganglia (2) Lower affinity for M2 (cardiac) and M3 (glandular) receptors c) Some drugs have antimuscarinic side effects. For example, tricyclic antidepressants (e.g. imipramine) have muscarinic blocking activity, which can contribute to side effects and which plays a major role in overdose toxicity of this class of agents. This is a secondary effect that is unrelated to their mechanism of antidepressant action. SSRIs do not exhibit antimuscarinic activity. Other widely used drugs with antimuscarinic side effects include first-generation antihistamines, certain antipsychotic drugs, and meperidine. d) Physiological effects of antimuscarinic drugs (1) Eye (a) Dilation of pupil (mydriasis) (b) Paralyzes accomodation by blocking contraction of ciliary muscle (interferes with near vision) (2) Increase heart rate by blocking vagal control of heart rate (3) Decreased salivary and gastric secretion (4) Inhibitionofsweating (5) InhibitionofGImotility (6) Bronchialdilation e) Therapeutic uses of muscarinic antagonists (1) Reducingexcessivesalivation (2) Treatmentofoveractivebladder (3) Reducing tremor (CNS action) (a) Treatment of Parkinson's disease (b) Reduces extrapyramidal side effects of antipsychotic drugs (4) Prevention of motion sickness (scopolamine; CNS action) (5) Ophthalmology, for mydriasis and cycloplegia (6) Reliefofacuterhinitis (7) Treatment of bradycardia due to excess vagal tone in acute myocardial infarction (8) Bronchodilation(treatmentofasthma,COPD) (9) Relaxation of GI smooth muscle for endoscopy or treatment of irritable bowel syndrome (10)Antidote for poisoning with cholinergic agonists (including Amanita mushroom poisoning) or esterase inhibitors (11)Pre-anesthesia sedation (scopolamine). Largely replaced by benzodiazepines (12)Management of peptic ulcer (pirenzepine) but can exacerbate gastric peptic ulcer by slowing gastric emptying. Largely replaced by more selective agents. f) Adverse/toxic effects ("Dry as a bone, blind as a bat, red as a beet, mad as a hatter") (1) Drymouth (2) Dry,hotskin (3) Dilatedpupils (4) Blurred near vision (5) Flush (6) Hallucinationsanddelirium (7) Hyperthermia(especiallywithatropineinchildren) (8) Tachycardia (greater with atropine than scopolamine) (9) May trigger acute symptoms in narrow-angle glaucoma (10)Urinary retention, exacerbation of benign prostatic hyperplasia (BPH) (11) Constipation (12)Exacerbation of gastric ulcer and acid reflux C. Acetylcholinesterase inhibitors 1. Acetylcholinesterase inhibitors reduce the enzymatic activity of acetylcholinesterase at both nicotinic and muscarinic synapses, thereby increasing the effective concentration of acetylcholine and extending its duration of action 2. Acetylcholinesterase inhibitors act by occupying the active site of the enzyme (acetylcholine-binding site) and preventing access of acetylcholine 3. The primary difference among the major classes of acetylcholinesterase inhibitors is in duration of action: a) Alcohols (edrophonium): competitive inhibitor; rapidly reversible (2-10 min) b) Carbamate esters (e.g. physostigmine, pyridostigmine, neostigmine) form a slowly reversible (0.5-6 h) covalent bond. This is the primary class of clinically used acetylcholinesterase inhibitors c) Organophosphates(e.g.parathion,malathion,sarin)formacovalent phosphate bond, which progresses ("aging") via a secondary reaction to an effectively irreversible bond. Binding of the inhibitor can be reversed in the initial stage by cholinesterase regenerators such as pralidoxime, but aging renders the inhibitory effect irreversible. These agents are primarily used as poisons (insecticides, nerve gasses). 4. Most are lipid soluble, and enter the CNS (neostigmine, with a quaternary ammonium, is an exception) 5. Therapeutic uses of acetylcholinesterase inhibitors overlap with the uses of muscarinic agonists. Clinical applications include: a) Treatment of senile dementia, Alzheimer type (donepezil) b) Myasthenia gravis (increases levels of acetylcholine at neuromuscular junction) c) Accelerate reverse of paralysis by nondepolarizing muscle relaxants d) Treatment of hyperthermia or supraventricular tachycardia due to antimuscarinic intoxication e) Treatment of glaucoma (applied topically) f) Treatment of postsurgical paralytic ileus g) Treatment of urinary bladder atony 6. Toxicity (e.g. pesticide or nerve gas poisoning) a) Muscarinic toxicity ("SLUDGE"; treated with atropine) b) Neuromuscularblockade c) Respiratoryfailure d) Confusion, ataxia, convulsions, coma e) Delayed development of peripheral neuropathy. This appears to be due to an off-target effect on another esterase (neuropathy target esterase) with a metabolic role important in neurite outgrowth. f) Treatment of acute toxicity: atropine to treat muscarinic symptoms, artificial respiration, benzodiazepine to relieve convulsions (if atropine fails to do so), pralidoxime to regenerate esterase.
carvedilol
B1, B2, and a1 antagonist
Diphenhydramine H1-->first generation antagonist
Benadryl H1-->first generation antagonist IP3/DAG-->Ca2+ reduced itching, rhinitis, conjuctivitis, hives high selectivity for H1 vs. H2; weak selectivity for H1 vs. other receptors anti-allergy; "histamine-induced" symptoms of mastocytosis and myelogenous leukemia CNS sedation (origin of some antipsychotic drugs) anesthetic activity OTC sleep aids antimuscarinic activity nausea/vomiting; motion sickness alpha adrenergic antagonism; 5-HT (serotonin) antagonism, increases appeptite in general: toxicity is ATROPINE-LIKE due to muscarinic receptor antagonism
critical alert values
CAV - some lab values deemed to be life-threatening and are designated as a CAV - must be relayed from lab to ordering clinician within 30 minutes of result - minimize post-analytic phase and possible prevent death, esp for outpatients
Ibuprofen Advil; Motrin nonselective NSAID inhibit COX-1 and COX-2
COX-2 inhibition mediates therapeutic effects (antipyretic, analgesic, anti-inflammatory-->see notes for details) COX-1 inhibition mediates adverse effects FOR ALL NONSELECTIVE NSAIDS naproxen is very similar but has a longer half-life GI toxicity is most common (15-30%); dyspepsia, GI bleeding, erosions, ulcers, loss of cytoprotective effect renal toxicity: sodium retention and edema; risk for pts with renal and CV disease; papilary necrosis and interstitial nephritis-->when combining apsirin and ibuprofen "aspirin intolerence" seen with both drugs; bronchospasm, rhinorrhea and/or hives mediated by leukotrienes prolong bleeding time; aspirin is worse because it permanently takes out a platelet's clotting abilities for its entire lifespan (4-7 days)
CYP450s
CYP3A4 fentanyl clearance hepatic toxicity of acetominophen CYP2D6 super polymorphic opoid metabolism (codeine) CYP1A CYP2E1 hepatic toxicity of acetominophen
Cushing Syndrome
Caused by: - chronic administration of large doses of GCs - tumor of the pituitary or adrenal gland Effect: too much GC (moon face, buffalo hump, poor wound healing, etc.)
Cl_T =
Cl_T = Cl_R + Cl_NR (renal and nonrenal) refers to elimination RATE of a drug from the body
clearance of organ
Cl_organ = (Cp_a - Cp_v)/Cp_a
Cl_organ =
Cl_organ = (Cp_a - Cp_v)/Cp_a aka what didn't come out of organ (what was eliminated) divided by total that went in
Evaluation of Dietary Supplements • Long history of use • Poorly regulated • Herb and supplement use is common • A few show promise; many do not • Up-to-date evidence-based information is available
Conventional Pharmaceuticals Derived from Natural Sources • Atropine • Colchicine • Taxol • Pseudoephedrine • Salicylin • Vincristine • Lovastatin Dietary Supplement Health and Education Act • DSHEA passed by Congress in 1994 • Dietary supplements include herbs, vitamins, minerals, metabolites, or extracts • Companies not required to prove efficacy or safety before marketing • Burden of proving inefficacy or lack of safety fell to FDA Name of product (w/ the word "supplement") • Fulldisclosureofallingredients - Identity & strength • Ingredient name (source), quantity (per serving), plant part • Net quantity of contents • Name and place of business of manufacturer, packer, or distributor • Directions for use • Must have disclaimer: not evaluated by FDA, not intended to diagnose, cure or prevent disease -Variation of Ginseng Preparations -Prevalence of Metals in 70 Ayurvedic Drugs: lead, Mercury, Arsenic, any metal 11+ 50% to kids GOOD NEWS - New regulatory framework - Companies have to follow GMP guidelines BAD NEWS - Manufacturers individually define the GMP guidelines and quality specifications, not FDA - Lack of enforcement provision - Ability for some companies to be exempt - Difficult for consumer to distinguish good from bad companies Varibles Affecting Quality • Plant species • Part of plant • Where, when, and how cultivated • Environmental contamination • Storage • Extraction, formulation, & packaging • Standardization of contents Data on Quality • Research post 2010 on the quality of herbal supplements in the American market sparse • From 2008 - 2012, increased number of dietary supplement recalls due to use of unapproved pharmaceutical ingredients (Harel, et al. JAMA 2013) • 465 drugs - class I recall (possible serious adverse health consequences or death) • Weight loss supplements • Bodybuilding • Sexualenhancements -20% of US - Perception of nature as benevolent and healing - "If it's natural, it must be safe" - Treat conditions w/ no conventional "cure" -Top Conditions Treated with Supplements and Perceived Helpfulness esp URI GI -Advertisements promising spectacular results -Recommendations by family & friends • Cultural, religious, & economic reasons Echinacea, ginsend, ginkgo biloba, garlic, glucosamine, st jogns, peppermint, omega 3 Evidence ↔ Public Use • Many pre-2000 positive trials - Low sample size - Inadequate description of supplement - No assessment of blinding • Post-2000 well-designed large NIH-funded negative trials - Saw palmetto, Echinacea, St. John's wort, Gingko, Glucosamine • Dissemination of evidence resulting in change in public use Large Negative Studies Saw palmetto for benign prostatic hypertrophy1 Ginkgo for dementia2-4 Echinacea for prevention/treatment of URI5-7 St. John's wort for major depression8-11 Glucosamine sulfate for osteoarthritis12 Promising Supplements: Fish Oils / Omega-3 Fatty Acids • Contains DHA and EPA • 20-50% ↓ triglycerides (Sirtori, Atheroscl 1998) • 15% ↓ nonfatal MI and death in post-MI patients (GISSI-Prevenzione, Lancet 1999) • Effective adjunct for cardiac risk factor reduction and treatment of post-MI patients (AHA Scientific Statement, Circulation 2002) • Brands: Berkley & Jensen (BJ's), CVS, GNC • Dose: 1-3 grams/day Supplements for Hyperlipidemia • Psyllium (Plantago ovata) - Decreases enterohepatic circulation of cholesterol • Walnuts - ↓LDL 8-16% (Sabate J et al, NEJM 1993) • Plant sterols (beta-sitosterol) and stanols - Prevent incorporation of cholesterol into micelles - ↓ LDL 5-17% (Law M, BMJ 2000) - Impact on CAD controversial - Marketed in spreads (Benechol) and supplements oy (Glycine max) • 1995 meta-analysis shows soy protein 25 g/dreduces TC 9%, LDL 13%, triglycerides 11% (Anderson, NEJM 1995) • > 40 studies and 1 meta-analysis since 1995 consistent w/ these findings (Zhan S et al, Am J Nutr 2005) Ginger • 0.5, 1, or 1.5 g supplementation 2x daily significant reduction in acute nausea during day 1 of chemotherapy (Ryan et al, 2012) • Ginger one hour before, and three and eight hours after start of chemotherapy significantly reduced incidence of acute and delayed emesis (Pillai et al, Pediatr Blood Cancer 2011) • Reduction of nausea up to 24 hours after chemotherapy with ginger supplementation (1.5 g 4x daily) (Panahi et al, Integr Cancer Ther 2012) Probiotics • Microorganisms that have beneficial properties for the host • Potential therapeutic effect for diseases including: - Pouchitis - Antibiotic-related diarrhea - Infectious diarrhea - Irritable bowel syndrome - Clostridium difficile toxin-induced colitis • Multiple systematic reviews demonstrated modest reduction in duration of infectious diarrhea Melatonin • Most thoroughly studied for jet lag • Systematic review of 10 placebo-controlled trials consistently showed reduced jet lag scores (Herxheimer & Petrie, Cochrane Database Syst Rev 2002) • Most trials have used 5 mg doses Xenadrine RFA-1 Citrus Aurantium peel (bitter orange, standardized for 4% synephrine) 125 mg Ma Huang (standardized for 6% ephedrine) 335 mg Guarana extract (standardized for 22% caffeine) 910 mg White Willow Bark extract (standardized for 15% salicin) 105 mg Acetyl L-Carnitine 100 mg L-Tyrosine 80 mg Ginger root 50 mg Vitamin B5 (pantothenic acid) 40 mg Common Dietary Supplements for Weight Loss • Ephedra-related compounds showed 0.9 kg weight loss/mo > placebo but 2.2-3.6 fold increase palpitations, psychiatric, autonomic, and GI symptoms (Shekelle, JAMA 2003) • Chitosan - blocks clinically insignificant amount of fat absorption • Chromium - may play a role in insulin sensitivity but not helpful for weight loss • Hydroxycytricacid-evidenceequivocal St Johns Wart reduces efficacy of HIV meds Certain herbal medicines may impact: - Coagulation: ginkgo, ginseng, garlic - Cardiovascular stability: ephedra - Glucose: ginseng - Anesthesia: valerian, kava - ↑Metabolism of perioperative meds: St. John's wort • Recommend avoiding for > 2 weeks prior to surgery >60% of patients did not disclose their CAM use to their physician (Eisenberg, Ann Intern Med, 2001) • Identify potential interactions, ineffective or unsafe therapies • "What prescription medications, over the counter medicines, vitamins, herbs, or supplements do you use?" AND • "Why?" • Empathy • Compassion • Warmth • Attentiveness • Listening • Competence • Confidence • 200 patients with non-specific complaints randomized to: 1. Positive Consultation, treatment 2. Positive Consultation, no treatment 3. Negative Consultation, treatment 4. Negative Consultation, no treatment • At 2 wks 64% receiving a positive consultation improved vs. 39% receiving a negative consultation (p = 0.001) • No difference between those treated and those not treated (p = 0.50) The Healer's Art Elective Spring Semester Supports medical students in recognizing, valuing, enhancing, and preserving the human dimension of health care • Sustaining idealism and altruism • Medicine as a calling to serve others • Learning how to grieve and heal loss • Preventing stress & burnout • Cultivating compassion and listening skills
Celecoxib
Cox2 selective agent (contains bulkier side chain to go into COX 2's larger side pocket on active site) Less adverse GI effects. (Not inhibiting gastroprotective prostaglandins in stomach wall) Higher TI than non selective NSAIDs Equal analgesic & anti-inflammatory efficacy No effect on platelets
Types of tolerance
Cross-tolerance = tolerance can develop for other drugs w/ the same mechanism Tachyphylaxis = the effect of the drug declines very rapidly (minutes) Desensitization = mechanisms for dec. effect (including tachyphylaxis) Sensitization = opposite of tolerance ;cocaine, locomotor sensitization
Depressing vs stimulatory effects of opioids:
Depressing - Acute = *analgesia, respiratory depression*, sedation, vasodilation - Chronic = tolerance Stimulatory - Acute: bradycardia, nausea/vomiting, mitosis, smooth muscle spasm, skeletal muscle hypertonus - Chronic: physician dependence
Effects of H1 receptor activation
Dilation of arterioles and venues (via NO release) Inc. venule permeability Smooth muscle constriction (large arteries and veins, bronchioles - asthma) Stimulation of sensory nerve endings (itch, flare, pain) CNS arousal (histaminergic fibers from tuberomamillary nucleus diffusely to cortex)
Which of the three drugs would you expect to be safest for treatment of congestive heart failure in a patient with asthma? Why? B1 Heart B2 Lungs
Drug A would be safest for chronic treatment of heart failure, because it is 100- fold more potent at blocking beta 1 receptors in the heart as compared to beta 2 receptors in the airways. The other two drugs show no selectivity for beta 1 vs beta 2.
3. Explain 5 essential cellular systems and where they are located within the cell.
ESSENTIAL CELLULAR SYSTEMS The following are the cellular systems that are essential for homeostasis and their respective locations within the cell: 1) aerobic respiration for the production of ATP - the mitochondria. 2) Osmotic and ionic balance - membranes. 3) Protein synthesis - ribosomes. 4) Structural maintenance and intracellular transport - the cytoskeleton and 5) Functional genetic apparatus - the nucleus. MOLECULAR MECHANISMS OF CELL INJURY ATP Depletion (Figure 2-17 in Robbins & Cotran). ATP, generated mainly by oxidative phosporylation within the mitochondria is the source of the high-energy phosphate essential for all active processes in the cell including signaling, active transmembrane transport of electrolytes and protein synthesis. Depletion to 5-10% levels is a potential deathblow. Some cells, such as skeletal muscle, have a robust backup system for ATP generation, namely anerobic glycolysis which occurs in the cytosol and others (CNS neurons, for example,) do not. ATP depletion is most frequently caused by anoxia. Toxins or chemical can achieve the same effect by generating free radicals that denature the enzyme systems, or they can directly disrupt the structure of the mitochondria. Calcium Influx (Figure 2-19 in Robbins & Cotran). Calcium is normally maintained at a very low concentration in the cytosol relative to the extracellular environment, and most is sequestered in mitochondria and endoplasmic reticulum. If injury directly or indirectly causes a breakdown of this compartmentalization, high cytosolic calcium activates a number of enzyme systems with potential damaging effects. These include ATPases(deplete ATP), phospholipases(damage membranes), proteases(damage cytoskeletal proteins) and endonucleases(nuclear and DNA fragmentation). Increased cytosolic calcium also increases mitochondrial permeability and induces apoptosis. Accumulation of Oxygen Derived Free Radicals (Figure 2-14 in Robbins & Cotran). Free radicals are chemicals that have a single unpaired electron in an outer orbit and are thus highly reactive. Consequently, their excessive accumulation within the cell can cause undesirable chemical reactions such as membrane damage due to lipid peroxidation, denaturation of structural proteins and enzymes and DNA damage. Oxygen free radicals are generated as a byproduct of aerobic glycolysis, nitric oxide metabolism and chemical reactions involving metals such as iron and copper. Other sources include absorption of radiant energy and metabolism of drugs and toxins. A major buildup of free radicals occurs with reperfusion of a tissue following a period of ischemia. Excessive accumulation of 14-8 free radicals is controlled normally by intracellular antioxidants such as Vitamin E and A and enzyme systems such as catalase and superoxide dismutase. Robbins & Cotran Fig 2-20
Review the organization of the autonomic nervous system and the type and location of specific receptor targets.
Endogenous neurotransmitter Acetylcholine Esterase-resistant agonist Carbamylcholine Nicotinic agonist Nicotine Muscle Relaxant (non-depolarizing) Tubocurarine Muscle Relaxant (depolarizing) Succinylcholine Denervating neurotoxin Botulinum toxin Acetylcholinesterase inhibitor Neostigmine Physostigmine Muscarinic agonist Pilocarpine Muscarinic antagonist Atropine Scopolamine
Disorders associated with defects in enzymes • Lysosomal Storage Diseases Intracellular digestive tract • Enzymes are manufactured in Endoplasmic reticulum • Acquire "address label" in the golgi apparatus • Transport to lysosomes • Intracellular(Autophagy) • Christian de Duve was awarded the Nobel Prize in Physiology or Medicine in 1974 for the discovery of the lysosome • the 2016 Nobel Prize in Physiology or Medicine to Yoshinori Ohsumi for his discoveries of mechanisms for autophagy • Extracellular (Heterophagy)
Features common to most of the Lysosomal Storage Disorders Autosomal recessive transmission • (except Hunters X linked recessive) (Hunter marks the spot with an X) • Patient population consisting of infants and young children • Storage of insoluble intermediates in the mononuclear phagocyte system, giving rise to hepatosplenomegaly • Frequent CNS involvement with associated neuronal damage • Cellular dysfunctions, caused not only by storage of undigested material but also by a cascade of secondary events triggered, for example, by macrophage activation and release of cytokines The distribution of stored material (organs) is determined by two factors • Site where most of the material to be degraded is found - Gangliosides in brain •Location where most degradation normally occurs - RES (macrophages) in lymph nodes, spleen and liver 1. Sphingolipids • Gangliosides • Cerebrosides • Sphingomyelin 2. Mucopolysaccharides • Heparan Sulfate • Dermatan Sulfate • Keratan Sulfate • Chondroitin Sulfate 3. Glycogen • Tay - Sachs Disease •Missingenzyme - Hexosaminidase •Accumulatedmaterial - Gangliosides •Microscopic - Cytoplasmicvacuoles • EM - lysosomes filled with "onion-skin" membranes • Tissues involved - CNS - Retina (cherry red spot) - Autonomic nerves - Heart, Liver, Spleen etc. -Hypotonia • Niemann- Pick Disease • Missing enzyme - Sphingomyelinase • Accumulated material - Sphingomyelin • Tissues involved - CNS and RES in the spleen, liver, lymph nodes and bone marrow • Type A variant - 75-80% of cases - severe infantile form with extensive neurologic involvement, marked visceral accumulation of sphingomyelin, progressive wasting and death by age three • Type B variant - Patients have organomegaly but no CNS involvement - they usually survive into adulthood •Gaucher Disease • Missing enzyme - Glucocerebrosidase - cleaves glucose from ceramide • Accumulated material - Glucocerebrosides • Tissues involved - spleen, bone, liver and sometimes neurons in the CNS • Three clinical subtypes Type 1 - adult - spleen and skeletal involvement, reduced enzyme, slightly decreased longevity Type 2 - infantile - cerebral, no enzyme, death at an early age Type 3 - intermediate between type1 and type 2 • Hepatomegaly - 2 to 3 times normal size • Splenomegaly - up to 15 times normal size • Thrombocytopenia - excessive bruising and bleeding • Anemia - fatigue • Low White Cells - susceptibility to infections • "Bone Crisis" - insufficient blood circulation • Bone thinning/fracture - "Erlenmeyer flask" - Enzyme replacement • Mucopolysaccharidoses (MPS I-VII) • MPS I - Hurlers Syndrome • Missing enzyme - alpha-L-iduronidase • Accumulated material - Dermatan sulfate, Heparan sulfate • Tissues involved - connective tissues - RES, endothelial cells, smooth muscle cells, fibroblasts (balloon cells) • Clinical - Hepatosplenomegaly, skeletal deformities, valvular lesions, subendothelial arterial deposits (myocardial infarction) •Glycogenoses - two metabolic pathways •Cytoplasmic pathway •Lysosomal pathway - glucosidase (acid maltase): G6Phosphatase Von Gierke, Muscle phos McArdle, Acid Maltase Pome disease Type II Von Gierke Disease • Missing enzyme - glucose -6- phosphatase • Accumulated material - glycogen (lipid in liver cells) • Tissues involved - hepatocytes, renal tubular cells • Clinical - convulsions (hypoglycemia) - hepatomegaly - growth retardation - infections - hyperlipidemia, hyperuricemia • Pompe Disease • Missing enzyme - alpha-glucosidase (acid maltase) • Accumulated material - glycogen • Tissues involved - generalized involvement - heart and brain cause most prominent symptoms • Clinical - cardiac enlargement with progressive heart failure, muscular weakness, neurologic symptoms, death in infancy.
Triple Response of Lewis
From intradermal injection of histamine 1. Red spot due to vasodilation 2. Wheel: swelling of red spot due to inc. vascular permeability 3. Flare de to axonally mediated reflex vasodilation
Cell walls of Gram-positive vs. Gram-negative bacteria
G-Pos: ML Thick Peptiglycan, Teichoic acids (no LPS/PSS/OM) G-Neg: SL Thin Peptidoglycan, Lipopolysaccharide (LPS, endotoxin), Periplasmic space (in some species this contains β-lactamases), Outer membrane (no teichoic acids0
Leukocyte, Role, and WBC type for Glycam-1 adhesion molecules
Glycam-1 is like the selectins, but a tiny bit different: Leukocyte = L-selectin (different) Role = Rolling (same) WBC type = PMN, Monocytes (no t cells!)
von Gierke Disease
Glycogen Storage Disease Type 1 missing enzyme: *glucose-6-phosphatase* accum material: *glycogen* (lipid in liver cells) tissues involved: hepatocytes, renal tubular cells clinical: - convulsions (hypoglycemia) - growth retardation - infections - hyperlipidemia
Pompe Disease
Glycogen Storage Disease Type II missing enzyme: alpha-glucosidase (acid maltase) accum material: glycogen tissues involved - generalized involvement; heart and brain cause most prominent symptoms clinical - cardiac enlargement with progressive heart failure; muscular weakness, neurologic symptoms, death in infancy
Histamine H1/H2 receptors histamine is lipophilic
H1: increased venule permeability H1: diliation of arterioles and venules via NO release H1: smooth muscle constriction (large arteries and veins, bronchioles) H1: CNS: arousal via tuberomamillary nuclues H2: stimulation of hydrogen ion secretion, vascular smooth muscle relaxation H2: increased HR and force of contraction (similar to B1 activation) H2: vascular smooth muscle contraction
Acetominophen toxicity
High doses = picks up extra liver metabolic pathway --> causes centrilobular hepatic necrosis Risk inc by: - CYP 2E1 inducers - CYP 3A4 inducers (both = more quinone formed) - alcohol (CYP2E1 induction and hepatotoxicity) - glutathione depletion (less quinone detoxified)
Relate the major physiological actions of prototypical adrenergic agonists and antagonists to their interactions with adrenergic receptors
I. Classification of adrenergic receptors Major classifications are based upon order of potencies of agonists and upon relative selectivity of agonists and antagonists. Effects of agonists depend upon their receptor selectivity, as well as the tissue distribution of adrenergic receptors. Α. α Receptors Epinephrine > Norepinephrine > Phenylephrine >> Isoproterenol Β. β Receptors: Isoproterenol > Epinephrine ≥ Norepinephrine >> Phenylephrine C. Additional subdivisions (distinguished by more subtle differences in agonist/antagonist potency) 1. Atleast3subtypesofα1,3subtypesofα2identifiedbycloning 2. β3: Present in adipose tissue, promote lipolysis
Explain how tumor stage is derived and its prognostic implications
In general, the choice of surgical approach or selection of treatment modality is influenced more by the stage of the tumor than by the grade. Stage simply refers to the extent of the tumor. It takes into account local growth (size, contiguous invasion) lymph node metastasis and distant metastasis. These criteria have been codified in the international TNM cancer staging system in which T refers to the size of the primary tumor, N to the number of node metastases, and M to the presence and extent of distant metastases. While the TNM system attempts to standardize the staging of malignancies in various organs, other staging systems, particular to individual organs, still persist and are utilized. Some examples include the Dukes staging system for colon adenocarcinoma, the Breslow and Clark classification of melanomas of the skin and the FIGO staging for ovarian carcinoma. The staging of lymphoid malignancies relies on a totally different system (Ann Arbor classification).
3. Describe the local and systemic factors that affect tissue repair and wound healing
In this lecture we use the example of a chronic peptic ulcer to illustrate the process of tissue repair. The molecular, cellular and histological events described are common to all tissues that undergo repair. Chronic peptic ulcer is a discrete defect in the surface and wall of the stomach caused by abnormal acid and pepsin digestion, initiated usually by H. Pylori infection or the use of anti- inflammatory medications (NSAIDs). A cross-section of the chronic gastric ulcer illustrates tissue strata that correspond to the sequence of events occurring in response to this chronic injury much in the way that a canyon's wall reveals geologic changes over time.
Anti-inflammatory indications for NSAIDs (what diseases)
Inflammation of joints: - RA, psoriasis, IBD - osteoarthritis - ankylosing spondylitis
Multiple Dosing Kinetics Cpss = Infusion rate / ClT
Kinetics of Continuous Infusion • Constant rate input, first order output, single compartment • Cp = Cpss [1-e-(kelt)] • At steady state, input rate = output rate infusion rate = Cpss ClT • Cpss = Infusion rate / ClT (LEARN!) • Time (t) when Cp is 50% of Cpss is one elimination half-life • Time (t) when Cp is 93% of Cpss is four elimination half-lives Time required to reach Cpss depends on elimination half-life not input rate A drug with an elimination half-life of 4 hours is administered by continuous intravenous infusion. How long will it take for the drug to reach ~93% of its final steady-state level? 4*4 Cpss = Infusion rate / ClT decreased clearance with unaltered infusion rate normal clearance decreased clearance with lower infusion rate iof clearance is lower you hshould lower the infusion rate Drug A has a half-life of 4 hours and a recommended infusion rate of 10 mg/min in normal 70-kg subjects In a 70-kg patient with renal failure, the volume of distribution of drug A is like that found in normal subjects, but its total clearance is only half as large. An appropriate infusion rate of drug A for this patient would be: . 5 mg/ml Loading Dose is the initial dose administered to achieve therapeutic Cp at start of regimen Loading Dose is important for: - Indication requiring rapid onset of effect - Drugs with long elimination half-lives and slow attainment of steady-state by continuous infusion • Loading dose does NOT affect the Cpss achieved by continuous infusion loading dose (IV bolus) is a tsaper from top to Cpss maintenance dose (IV infusion) is a taper from bottom to cpss First-order elimination, single compartment distribution • Constant rate input, D / t maintenance dose D / dosing interval t • Each dose D diluted into Vd adds C0 to Cp D/Vd = C0 • Cp rises from Cpmin to Cpmax with each dose Cpmin + C0 = Cpmax e Kinetics Accumulation Kinetics Cmin is 'trough' Cp. Cmaxss to Cminss is 'therapeutic window' Accumulation from First Dose to Steady-State • The shorter the dosing interval, relative to the elimination half-life, the greater the drug accumulation • If dosing interval is greater than 7 half-lives, less than 1% remains and accumulation is.... NEGLIGIBLE • If dosing interval is about 1 half-life, then the accumulation is......TWO-FOLD If the therapeutic window of a drug is 125 - 500 mg/l and the t1/2 is 12 hr, what is the appropriate dosing interval for fluctuation specifically from this peak to this trough?00 If the therapeutic window of a drug is 125 - 500 mg/l and the t1/2 is 12 hr, what is the appropriate dosing interval for fluctuation specifically from this peak to this trough?00 24hr Fluctuation around a Cp"average" from Cmaxss to Cminss • Cp"average" = ( D / t ) / ClT • About the same Cp"average" can be achieved with infusion, with small dose at frequent intervals, or with high dose at long intervals. • What are the advantages and disadvantages of each regimen? Oral Formulations • solutions, tablets, controlled release capsules • absorption half-life and bioavailability dependent on disintegration and dissolution rates • dissolution rate dependent on factors such as drug crystal form, excipients (inactive ingredients), tablet compression force Rate Limiting Steps in Drug Absorption Disintegration & release Solid drug particles Rate processes for solid, oral, immediate-release products: •disintegration of drug product and release of drug •dissolution of drug in aqueous environment •absorption across biological membranes into the systemic circulation Dissolution Absorption Drug in drug product Drug in solution Drug in body Tablet Formulations Oral Formulations:Factors that affect dissolution rates Excipients \ Starches • Excipients are inactive substances in drug products (diluent) • Starches are added to drug products to enhance disintegration, the breakup of the tablet. • Starches bind water and swell, enhancing disintegration of the tablet and dissolution of the active drug. Oral Formulations:Factors that affect dissolution rates Drug crystal forms Chloramphenicol has several crystal forms that have different aqueous solubilities and absorptions. The b form is more aqueous soluble and better absorbed The oral suspension that contains the highest concentration of the b polymorph is absorbed the greatest. serum levels vs. time Oral Formulations:Factors that affect dissolution rates Particle/Crystal Size • the smaller the particle size, the greater its surface area, the faster its dissolution rate • the smaller the crystal size of chloramphenicol, the faster the absorption rate Oral Formulations:Factors that affect dissolution rates Compression Force • the greater the compression force used to create the tablet, the longer it takes for the tablet to dissolve Oral Formulations\ Buccal Administration Buccal Fentanyl Tablet • Buccal administration is intended for absorption in the oral cavity. • Buccal surface has large blood flow, provides rapid absorption for lipid-soluble drugs. • Venous drainage from the mouth bypasses the portal circulation and protects drug from first-pass metabolism. Oral Controlled Release Devices • Purpose: slow absorption and a more sustained duration of action • Technologies: - 'Gastrointestinal Therapeutic Systems' with release based on osmotic pressure of core - Capsules containing beads manufactured with differing dissolution rates Oral Controlled Release Devices Osmotic Pump Gastrointestinal Therapeutic System (GITS) Oral Controlled Release Devices Osmotic Pump Gastrointestinal Therapeutic System (GITS) PROCARDIA® (nifedipine) Osmotic Pump: GITS two 10 mg capsules 60 mg dose in the GITS Oral Controlled Release Devices • Drug product comprises a core (2 drug compartments and one compartment with osmotically active polymer) a surrounding semipermeable membrane, and an overcoat of immediate-release drug. • The drug overcoat dissolves in the GI tract providing the initial drug dose. • Water diffuses into core, expands the polymer, pushing dissolved drug out of the pore. • Over time, drug in compartment 2 dissolves and is pushed out of the pore, maintaining plasma drug levels for once-daily dosing Methylphenidate Special Delivery Devices to enhance safety, ease, and duration of administration • Ophthalmic • Uterine and vaginal • Subcutaneous • IV • Transdermal • Pulmonary Special Delivery Devices Vaginal Ring • NuvaRing® is a flexible plastic ring containing an estrogen and a progesterone inserted into the vagina • Hormones diffuse out of the ring, enter the bloodstream, and prevent ovulation for 3 weeks • On ring removal menstruation occurs Special Delivery Devices Subdermal Implants for long-term birth control Implanon® a progestin-containing rod implant for subdermal use indicated for women for the prevention of pregnancy. The rod consists of a copolymer core containing the synthetic progestin etonogestrel surrounded by a copolymer shell. Progestin is released into the circulation providing a long-acting (up to 3 years), reversible, contraception. Drug Infusion Pumps for Long-term Outpatient Use Insulin Pump and Catheter • Exteriorized programmable pumps for s.c. insulin administration in diabetics Drug Infusion Pumps for Long-term Outpatient Use Programmable Implanted Pump • Surgically implanted pump for spinal analgesic or antispasmodic agents Port for IV Chemotherapy Nanotechnology and Drug Delivery Wang, AS, Langer, R, Farokhzad, OC Ann. Rev. Med. 63:185-98. 2012 Liposomes: ex. the antifungal agent amphotericin B Albumin-bound nanoparticle: ex. antitumor agent paclitaxel Coronary Vessel Stent: Drug- coated to inhibit restenosis • Stents maintain patency of the coronary vessels to occlusions caused by atherosclerosis. • Active agent is embedded in a polymeric matrix that releases drug directly to the target site in the vessel. • Direct drug delivery into the vessel reduces systemic toxicity of cytotoxic drugs that act to inhibit the proliferation of smooth muscle that cause occlusion. • Inhibitors of cell replication include sirolimus (rapamycin, an mTOR inhibitor) and paclitaxel (taxol, a microtubule inhibitor). Transdermal Drug Delivery • Provides prolonged delivery for drugs with short half- lives to achieve effective levels • Avoids problem of low oral bioavailability due to first- pass effect • Allows for drug device removal to avoid drug tolerance • Useful for lipophillic agents with low mw Nitroglycerin-containing Transdermal Patches Inhalation Delivery Devices for Drug Particulates • Improves selectivity of bronchodilators and anti-inflammatory agents for asthma and chronic obstructive lung disease (COPD) • Permits routine outpatient use • Metered dose inhalers, nebulizers, and diskus differ in design, cost, and ease of use Pulmonary Devices for Targeted Delivery to Airways Metered Dose Inhaler • Metered dose inhalers and nebulizers release small aerosolized particles of drug • Small fraction gains access to deeper regions of the airways for efficacy in asthma and COPD • Much more selective effect than oral route; reduces risk of systemic adverse effects Pulmonary Devices for Targeted Delivery to Airways Ultrasonic Nebulizer for Drug Administration by Inhalation • Localized delivery improves drug selectivity for asthma and COPD Pulmonary Devices for Targeted Delivery to Airways Diskus • Delivery device for anti- inflammatory and bronchodilator agents for asthma • Advair Diskus® contains fluticasone, an anti- inflammatory steroid and salmeterol, a bronchodilator for asthma
Which of the following is the most appropriate interpretation regarding the confidence interval that you calculated?
It suggests a significant increase in risk, but it is a wide, imprecise confidence interval because of the relatively small number of subjects using phenacetin daily. The 95% confidence interval ranges from 2.5 to16.83. This is the range within which the true odds ratio lies, with 95% confidence. This interval does not include the null value of 1.0, so the association is statistically significant using a criterion of p< 0.05. Nevertheless, the interval is quite wide, because the estimated odds ratio was based on a relatively small sample size. As a result, the estimate lacks precision, and while it appears that there is a significant increase in risk, one isn't confident about its magnitude.
TISSUE REPAIR, CELLULAR GROWTH, FIBROSIS AND WOUND HEALING
Labile Cells: Surface Epithelia Stable Cells: Liver, SM, Vessels Permanent Cells: Neurons and Skeletal muscles Proliferation Zones Ki67 IHC (G2 S G1) of Tonsil -Stem cells are undifferentiated cells known for self-renewal issues included fx integration and immunogenicity. Embryonic stem cells are the 32 cell blastocyst which is pluripotent. Adult stem cells have niches, markers. -Mature Cells Can be Reprogrammed to become Pluripotent: four retrovirally delivered genes, Oct4, Klf4, Sox2, and cMyc. (genes for stemness) -Disease issues by fibrosis: MI (myocardial fibrosis): cardiac failure, CVH (cirrhosis): portal hypertension liver failure, Diffuse alveolar damage pulm intersitital fibrosis (res failure). -Cirrhosis of Liver -Pulmonary Fibrosis -Chronic Ulcer of Foot -Cutaneous Wound Healing first intension blood brings neutrophils or second intention neutrophils bring blood. -Factors affecting wound healing: local: blood supply; denervation; infection; foreign body; necrotic tissue; mechanical stress; surgical technique; type and location of tissue. Systemic: diabetes; malnutrition; steroids; uremia; hypoxia; vitamin C deficiency; malignant disease -Chronic Peptic Ulcer H&E stain, Trichrome stain I, II, III, IV layers. I: Inflammation Necrosis and Acute Exudate II: Cell Prolif Granulation Tissue III: Synth ECM Granulation Tissue and ECM IV: Fibrous Scar Layer I Acute inflammation and Necrosis: Fibrin, Neutrophils (MPO), Macrophages, Platelets, Cytokines (interleukins, Interferons, TNF), Growth Factors (PDGF, FGF). Regeneration of Surface Epithelium - Ki67 2. Cell Proliferation and Migration - Layer II Granulation Tissue Capillaries, fibroblasts, macrophages, Growth factors: EGF-TGFa, PDGF, FGF, VEGF, TGF-B, Angiopoietins 3. ECM Functions: • Tissue Texture -turgor, elasticity, rigidity • Reservoir - growth factors • Substratum/matrix - cell adherence and migration 1. Basal Membrane 2. Interstitial Matrix -Fibrous structural proteins Collagens Elastins -Cell Adhesion Proteins (CAMs) Cadherins Integrins Fibronectin Laminin -Gel of proteoglycans and hyaluronan -Fibronectin: Large glycoprotein, produced by fibroblasts, endothelial cells, monocytes - specific binding domains -Laminin Most abundant in BM, cross-shaped, spans BM and links specific receptors to collagen IV and heparan sulfate Ingerins: B,A Vinculin, Talin, Paxillin, Tensin, Actin, ECM Gel: Proteoglycans Core proteins linked to disaccharide polymers Heparan sulfate, chondroitin sulfate, Regulate ECM structure and permeability, Hyaluronan Large molecule of repeating disaccharides Associates with various proteins & receptors Binds water to give tissues turgor pressure Abundant in matrix of actively migrating cells Events in Layer IV: Remodeling of ECM and formation of collagen plates - Metalloproteinases, gelatinases,stromolysins,Wound contraction - Myofibroblasts • Regression of blood vessels - Apoptosis
Lidocaine, benzocaine, cocaine
Local anaesthetics - inhibit VG Na+ channels
Opioids with long vs medium vs short t1/2
Long: methadone (super long, 1/day pill), levorphanol Medium: morphine, hydromorphone Short: meperidine, fentanyl, remifentanil **super fast!
Morphine-6-glucuronide
Most morphine glucuronidated to morphine-3-glucuronide 15% to morphine-6-glucuronide - polar active metabolite - much slower clearance - builds up over prolonged time on opioids - renal failure patients have a hard time clearing it
Antihistamines
Muscarinic Antagonist due to cross reaction of first generation anti-histamines w/ muscarinic receptor, but can be used as an anti-emetic or nausea drug
Differential diagnosis of high eosinophils (eosinophilia)
NAAACP WWW - neoplasm - allergic diseases - asthma - addison's disease - collagen vascular disease - parasites - worms - wheezes - weird diseases
6. Describe how neutrophils and macrophages\monocytes kill bacteria.
Neutrophil activation. Neutrophil activation is an important component of the acute inflammatory response. This activation occurs to clear bacteria and remove necrotic tissue. Neutrophils become activated to kill bacteria through two principal mechanisms. Neutrophil extracellular nets. These are strands of chromatin derived from the neutrophil which contain antimicrobial peptides. These snare and kill the bacteria. Neutrophil phagocytosis, engulfment and killing. Several mediators will enhance these processes by binding to receptors on the surface of the cell. Many of these have already been described because they also induce chemotaxis. Additionally, opsins such as antibodies and fragments of the complement cascade will bind to the bacteria. These opsonized bacteria will then bind to receptors on the cell surface to facilitate phagocytosis. After neutrophils have phagocytosed the bacteria, the engulfed bacteria will be combined with lysozyme in the phagolysosome to effectively destroy the pathogen. Pathogens are also destroyed through the generation of reactive oxygen and reactive nitrogen intermediates. In addition to neutrophils, monocytes and macrophages will also phagocytose bacterial and fungal pathogens.
The authors used stratification and logistic regression to control for confounding by diabetes, hypertension, headaches or specific symptoms. If, after adjusting for these factors, the odds ratios for analgesic use and renal disease did not change very much, what would this suggest?
One can tell whether another risk factor is causing confounding by adjusting for it; if the magnitude of association changes when you adjust (using either stratification or multivariate analysis), then there was confounding. If the relative risks or odds ratios don't change much after adjusting, then there was little, if any, confounding.
Opiate vs opioid vs narcotic
Opiate = in poppy (morphine, codeine) Opioid = acts like morphine (e.g. Alkaloid peptide) Narcotic = gov't definition including morphine, heroin, and cocaine (abusable, but no real definition/not sensible categorization)
3. Match morphologic and histologic images to causative toxic agents in the environment and/or their mechanisms of action.
Organic Chemicals [10] Organic chemicals are substances that contain carbon and often hydrogen. Exposure to toxic organic chemicals may occur either occupationally (at the workplace) or in our role as consumers (often at home). One toxic category is volatile organic compounds, including: chloroform and carbon tetrachloride, found in degreasing agents like dry-cleaning products and paint removers; and benzene and 1,3-butadiene, used in the manufacturing of plastics, lubricants, rubbers, and dyes. These compounds enter the body mainly through the lung, and can cause headache and dizziness and, with chronic exposure, may impair liver and kidney function. [11] Another category of toxic organic compounds comprises manufactured products, such as: organochlorines, including the now-banned polychlorinated biphenyls (PCBs), dioxin, and pesticides like lindane and the now-banned DDT; vinyl chloride monomer; phthalate esters; and possibly bisphenol A. Sources, toxic effects and known or suspected mechanisms of toxicity Organochlorines 1. Polychlorinated biphenyls (PCBs) 2. Dioxin (TCDD) 3. DDT*, Lindane 1. Old capacitors, transformers (banned 1977) 2. Incomplete waste inciner. 3. Pesticides (*banned1973) Chloracne, rashes, liver damage; endocrine disrupter, probable carcinogens / → binding to aryl hydrocarbon receptor on cells → transcriptional change Vinyl chloride (monomer, VCM - gas with sweet odor) Manufacturing (pre- regulation) of polyvinylchloride (PVC) products (pipes, flooring); improper PVC incineration Liver angiosarcoma / ? Processing of metabolites in liver Phthalate esters (used as plasticizers) Flexible plastics (shower curtains, toys, adhesives, catheters) Reproductive toxin in animals ? Human effect Bisphenol A (BPA)? Polycarbonate bottles, coatings of food cans Estrogen mimic (proliferative effect) A characteristic manifestation of exposure to organochlorines is an acne-like eruption with cysts, hyperpigmentation, and hyperkeratosis, called chloracne. This, as well as systemic toxicities, were seen in two incidents of unintentional PCB poisoning in China and Japan in the 1960s, and in a publicized case of deliberate dioxin poisoning of a Ukranian presidential candidate in in 2004.
Regulation of Drug Development, Marketing, and Prescribing in the U.S.
Patent Medicines of the 1800s • Botanical extracts • Alcohol as diluent • No controls over content or claims of efficacy or safety • Lydia Pinkham's Vegetable Compound promoted for women's ailments (19% alcohol) 1902: federal controls over vaccines • 1906: Food and Drug Act - drugs shipped in interstate commerce must be labeled properly according to ingredients • 1912: amendments - prohibition of false advertising claims Sulfanilamide Disaster • 1936-7 • Elixir formulated with diethylene glycol (antifreeze) as solvent • Resulted in over 100 fatalities • Mislabeling conviction - Elixir means alcohol Food, Drug and Cosmetic Act of 1938: Proof of Safety • Drugs shipped in interstate commerce must be proven experimentally to be safe • Experimental data on safety must be submitted to FDA for marketing approval Prescription vs OTC • 1951 Durham-Humphrey Amendment - Distinction between the two categories of prescription and over-the-counter (OTC) - Standards of labeling and safety apply to both - Certain criteria of safety must be satisfied to permit OTC status Thalidomide Disaster • 1961: thalidomide, a sedative used for morning sickness, found to cause major limb malformation in babies born in Europe • FDA denied approval • Generated climate for U.S. reforms to improve evidence of safety and efficacy Proof of Efficacy • 1962: Kefauver-Harris Amendments - Efficacy for indication must be proven experimentally - Label and advertisements must list all ingredients and side effects - Subjects in clinical trials must give informed consent Safeguards of Subjects in Clinical Trials 1991 Federal Policy on Protection of Human Subjects • Approval of trial by Institutional Review Board (IRB) • Are subjects rights and welfare protected? • Are risks to subject outweighed by benefit or importance of new knowledge? • Has subject given informed consent without coercion? Types of Products Regulated by the FDA • New molecular entities, new drug combinations, new dosage forms or strengths, diagnostics - Center for Drug Evaluation and Research, CDER • Proteins such as vaccines and cell products - Center for Biologics Evaluation and Research, CBER • Medical devices and materials - Medical device amendment of 1976 • Dietary supplements - Dietary Supplement Health and Education Act of 1994, DSHEA, false advertising only The IND • Notice of Claimed Investigational Exemption of a New Drug - Composition, manufacturing, animal studies, clinical protocols, clinical investigators • Must be approved by FDA before clinical trials begin Phase 1 • Pilot study in 20-80 healthy volunteers • Determination of safety of several doses • Determination of pharmacokinetic properties • Non-blinded • About 20% of tested drugs are approved Phase 2 • Studies in 100-200 patients with target disease • Placebo and active drug controls • Single-blind • About 30% of tested drugs are approved Phase 3 • Studies in many (about 5000) patients with target disease • Determination of efficacy for indication and side effects • Usually double-blind and cross-over design with placebo or active control • About 70% of tested drugs are approved New Drug Application NDA • Data from all studies submitted to FDA - FDA summary and response available at www.fda.gov for approved drugs • FDA may require additional studies prior to approval The 'Label' • Approved by FDA as part of NDA process • Same as package insert • Available in The Physician's Desk Reference • Contains chemistry, pk, indication, side effects, toxicity, contraindications, dosage, information in special populations • NOT a critical guide! (see NEJM 36:1230,2009) Out-of-Pocket and Capitalized Cost per Approved New Compound Phase 4 • Additional trials, in some cases FDA requested • Post-marketing surveillance - Detection of low-incidence side effects <1 in 10,000 - Based on physician and hospital reports to FDA and manufacturer • FDA MedWatch reporting program • Data available through FDA's Adverse Event Reporting System - May result in black-box warning on label or recall of drug • Additional trials, in some cases FDA requested • Post-marketing surveillance - Detection of low-incidence side effects <1 in 10,000 - Based on physician and hospital reports to FDA and manufacturer • FDA MedWatch reporting program • Data available through FDA's Adverse Event Reporting System - May result in black-box warning on label or recall of drug Impact of Label 'Indication' • Illegal to ship interstate for other than label indication • Physician may use product for 'off- label' indication in individual patient • IND must be obtained for clinical trial for new indication, even of approved drug • Label 'indications' change, as new data on efficacy are obtained Regulations to Decrease Cost: Approval of Generics • Patents expire 20 years after filing of patent - Patent filing occurs generally early in development - Effective patent life lasts less than 14 years • Generic formulations, marketed after patent expires, are generally much less costly than original patented drug Approval Process for Non-patented Drug • Small MW drug: a 'generic' - Generic manufacturer must prove bioequivalence of generic formulation to the patented drug product • Same amount of active ingredient • Similar bioavailability measured in healthy human subjects - within + 20% of proprietary formulation - based on AUC, peak Cp, and time of peak - Data submitted to FDA as 'abbreviated' NDA - Low research expenditure, so product typically much less costly Approval Process for Non-patented Drug • Protein therapeutic: a 'biosimilar' - More complex studies required as manufacturing in cell culture can lead to subtle differences in composition and structure - May require studies of clinical efficacy and safety, not just study of bioavailability - Regulations initiated in 2009 and evolving Measures to Increase Access to New Drugs • Treatment IND (1987) - Promising investigational drugs in late Phase II or III can be available for patients with life-threatening conditions or serious chronic conditions - Regulatory safeguards apply to patients as to experimental subjects - Sped access to drugs for HIV Regulations to Decrease R&D Cost and Speed Access: Shortening FDA Review Times • Prioritizing NDAs (1991) - Priority: important therapeutic gain, new class NDA review time about 6 months - Standard: modest therapeutic gain, 'me-too' drugs NDA review time about 12 months • Prescription Drug User Fee Act (PDUFA, 1992) - Fees collected from manufacturer to cover NDA review - Incentive for improved quality of the NDA to shorten review times Food and Drug Administration Modernization Act (FDAMA) 1997 • Access to information on clinical trials for serious illnesses ClinicalTrials.gov • Incentives for clinical trials in children • 2007 reauthorization included plans to improve post-marketing drug safety surveillance and review of TV advertising Are the FDA and its advisory committees serving the public need? - Avorn, J. Keeping science on top in drug evaluation, NEJM 357: 633-5, 2007. • Are the labeling requirements inadequate? - Stafford et al. New, but not improved? Incorporating comparative-effectiveness information into FDA labeling, NEJM 361:1230-2, 2010. • Is supply-chain globalization overtaxing the inspection capabilities of the FDA? - Mullin, R. C&EN News 89: 11-15, 2011. Direct-to-Consumer Advertising of Prescription Drugs • Substantial expenditure since about 1997; 4.4 billion dollars in 2010 (Kornfield et al., PLoS One, 8(3): e55504, 2013) - 1.4% of sales - about 18% of promotion to providers - declining since 2006 • Effective marketing strategy - Increases consumer awareness of drug products - Increases request by consumer for heavily promoted proprietary drugs - Increases prescribing by physicians in response to request of more expensive therapeutics • Substantial percent of total marketing budget and much more than direct-to-consumer (estimated at 5.4 times greater in 2010) • Includes free samples, the largest cost category, distributed to physicians upon FDA approval to generate sales • The 2013 Physician Payment Sunshine Act now requires manufacturers to report to DHHS all 'transfers of value' (meals, gifts, travel) to individual physicians - Information posted on DHHS website • Regulatory authority: state boards authorized by state legislation • Prescribers - physicians and osteopaths - in some states with restrictions pharmacists, nurse practioners, physician's assistants, optometrists • Prescriber • Patient's name and address • Drug name • Dose and quantity dispensed • Instructions for use • Refills • Date • Physician's signature Shift to e-Prescribing • About 4 billion prescriptions filled annually in U.S. • e-prescribing used by about 70% of physicians in 2014 (10-fold increase from 2008) • Required by some health plans, insurers, and hospitals • e-prescribing may improve efficiency, reduce cost, reduce errors, increase safety; but has drawbacks such as no e-discontinuation • Physician prescribes by generic name metoprolol • Physician prescribes by proprietary name TOPROL • Physician prescribes to prohibit substitution TOPROL " Dispense as written" Formularies in hospitals, managed care organizations, and insurers are designed for cost-saving • In some managed care settings - prescriber chooses drug class - pharmacist dispenses drug in that class from the formulary Regulation of Drugs of Abuse • Opioidsrecognized as major medical problem by end of 19th c. • Manypatent medicines contained high levels of opioids Harrison Narcotic Act of 1914 • Regulation of production and use of narcotics - opioids, cocaine, marijuana (1937) • Enforced by Federal Bureau of Narcotics in Treasury Department - taxation of physician prescriber Controlled Substances Act of 1970 • Purpose - decrease availability of drugs to potential abusers • Enforcers - Drug Enforcement Agency located within the Department of Justice - DEA issues permits to physicians for a fee for right to prescribe controlled substances Schedules of Controlled Substances • Chemicals categorized into schedules based on: - abuse potential - pattern and significance of abuse - risk of dependence • Schedule affects: - registration of handlers, record-keeping, storage security, limits on dispensing - penalties for illegal trafficking I Research use only heroin, marijuana (in conflict with laws of many states!) II No prescription refills morphine, amphetamine, III Limit to refills codeine IV Limit to refills benzodiazepines V O-T-C with some limits antitussives with low codeine • Physician's DEA registration number • Physician must also register with state • e-prescribing allowed by DEA as of 2010 Keep informed about changes in drug regulations and their interpretation! - Federal level: refer to FDA Guidance website - State level: • MA Prescription Monitoring Program now covers data on prescribing of schedule II-V substances and requires review of patient prescription history before prescribing schedule II and III drugs. • MA March 2016, three measures to reduce opioid deaths including 7-day limit on new opioid prescriptions • Work to improve regulations on behalf of your patients and public health • Consider that some regulations may increase cost of drug use and reduce incentives for drug discovery
Plant species used — Several common herbal products are drawn from closely related species. As an example, studies of echinacea for the treatment and prevention of the common cold utilize Echinacea purpurea, E. pallida, and/or E. angustifolia. The relative pharmacologic activity of these different species is unclear. Serious injury also has resulted from the misidentification of other plant species and subsequent mislabeling [43].
Plant parts used — Different plant parts from the same species may have different pharmacologic activity. As an example, echinacea products vary according to the proportion of root and aerial parts used. The relative activities of these different parts of the same plant are uncertain. Other inherent problems involve contamination by plant parts not normally utilized [44]. Harvesting and storage conditions — The strength of a plant's pharmacologic activity may also vary according to where it was raised, when it was harvested, and the length of time it was stored [45]. Plant products and their active constituents can vary from year to year due to climatic changes involving rainfall, sunlight, and even genetic composition [44]. Problems with prolonged storage may also lead to microbial contamination. Processing — Herbs can be processed and formulated multiple ways. Whole herbs can be homogenized and extracted using solvents (eg, alcohol, glycerol, acetone, water). These extracts can be dried and encapsulated, or made into liquid tinctures. Whole herbs can also be eaten or consumed as teas. Topical applications can be made using poultices or creams. Different processing techniques can result in different chemical composition of the final product. Accuracy of labeling — Multiple reports of inaccurate herb labeling have been documented. As an example, a study of commercially available Asian ginseng products showed that among products with a labeled concentration of ginsenosides, the actual measured ginsenoside varied from zero to over 300 percent of labeled concentrations [46]. Similarly, in a study of valerian products, 4 out of 17 products tested had no detectable levels of the expected valerenic acids, while another four had only one-half the expected amount [47]. A study that used DNA barcoding by polymerase chain reaction (PCR) examined 44 herbal products available in North America [48]. Fourteen of the 44 products (32 percent) contained a different plant species and did not contain the labeled product. Furthermore, many brands of the same herb have labeling recommendations that vary greatly [49]. Among 880 commercial products of the 10 most commonly purchased herbs, 43 percent were consistent with generally accepted benchmarks and 37 percent were either not consistent or were insufficiently labeled to determine whether or not it was consistent with generally accepted benchmarks. Standardization — Herbs are complex substances with dozens or hundreds of chemical constituents. Often it is unclear which of these chemicals play an important role in the herb's pharmacologic activity. Some herbal products are standardized to contain a specified amount of one or two chemicals or chemical groups thought to be the active ingredients for the herb. Examples include ginkgo extracts standardized to 24 percent flavonoid glycosides and 6 percent terpenoids, and St. John's wort standardized to 0.3 percent hypericin. The latter is an example of a product standardized to a component that many experts believe is not the most important component for antidepressant activity [50,51]. (See "Clinical use of St. John's wort".) Even when herbal preparations are labeled "standardized," there may be significant variation. One study of echinacea found that the content did not match the labeling in 47 percent of samples labeled "standardized" [52].
Special populations
Pregnancy and nursing — Few animal or human studies have been conducted on the safety of herbal medicines in pregnancy or while nursing. Given the paucity of data for these populations as well as the uncertainty in product quality, women who are pregnant, contemplating pregnancy, or lactating should generally be discouraged from using herbal treatments. Infants and children — Parents should be cautioned about the relative lack of studies demonstrating efficacy and safety of herbal medicines in infants and children [91]. Additional concerns are proper dosing in this age group, greater susceptibility to potential contaminants, and uncertainty of product quality. Older adults — Caution should be exercised in the use of herbs in older adults due to possible decreased renal and hepatic clearance of herb and drug metabolites. Additionally, for older individuals taking multiple medications, there is a greater potential for herb-drug interactions [45]. Surgical patients — No large prospective study of the impact of perioperative herb use on surgical outcomes has been completed. Herbs may theoretically impact surgery through altered coagulation (eg, ginkgo, ginseng, garlic), cardiovascular stability (eg, ephedra), glucose control (ginseng), anesthesia (eg, valerian, kava), and increased metabolism of perioperative medication (eg, St. John's wort). Case reports of perioperative bleeding associated with Ginkgo biloba [92] and saw palmetto [93] have been reported. Authors have recommended avoiding herbs for at least two weeks prior to surgery [94].
PGE2 & PGF2a
Prostaglandin Metabolite of arachidonic acid via COX pathway increased GI motility and secretion; GI cytoprotection; decreased gastric acid secretion; uterine contraction
Evaluating Drug Efficacy and Toxicity: NSAIDs for Osteoarthritis •Why the study was done, and who sponsored it? •What was the study design? •What were the end-points, and how were they defined? •What statistical analysis was applied, and was it appropriate? •Are there problems that limit the validity of the study, either internally or with respect to generalizability to the case (e.g., choice of subjects, dropout rates, duration of drug treatment)? •Whether the data provide evidence of drug efficacy and/or toxicity that relate to this case?
Randomized Controlled Trial • Advantage: estimation of absolute and relative risk of efficacy or toxicity, determination of causality • Disadvantage: expensive, not feasible for outcomes with low incidence due to need for recruitment of large numbers of subjects • Limitations: choice of study population, drug regimen, end points, duration of study; comparator treatment; subject drop-outs; need for monitoring of drug use; generalizability of findings Interpretation of Data • Rate or proportion data - percent of subjects with outcome of interest compared with chi-square analysis - absolute risks, p, compared in treatment groups • Ratio provides 'relative risk', p1/p2 • Difference, p1-p2, provides 'absolute risk reduction' (ARR) • Number needed to treat NNT = 1/ARR • Continuous measurement data - Evaluated with analysis of variance 1.4%/2.90 = RR Greater mean effect of diclofenac than acetaminophen after 6 weeks in reduction of primary OA outcome measure (WOMAC Score) based on ANOVA Stratification of Patients by Baseline Disease Severity Efficacy of diclofenac and acetaminophen after 6 weeks did not differ in patients with mildest baseline OA (p>0.05) Greater efficacy of diclofenac than acetaminophen observed in patients with more severe disease (p<0.05) Potential Pitfalls - bias for publication of 'positive' findings, study search process, and selection for inclusion - heterogeneity of outcome - lack of detailed study information - method of data analysis • Advantage - greatly increased sample size Key Features of Valid Meta-Analysis (Cleveland Clinic Journal of Medicine, CME) • Well-defined objectives, including precise definitions of clinical variables and outcomes • An appropriate and well-documented study identification and selection strategy • Evaluation of bias in the identification and selection of studies • Description and evaluation of heterogeneity • Justification of data analytic techniques • Use of sensitivity analysis. • Advantages - study of rare outcomes - low cost and short study time relative to randomized control trial • Disadvantages - inability to establish causality, only an association - many potential biases - inability to determine absolute risk of the outcome from drug use, because subjects with the outcome are selected for the study Recall bias - Problem with self-report or interview - Reduced by use of data from automated collection sources or information recorded prior to outcome • Informationbias - Due to measurement error or misclassification - Differing assessment of outcome in case vs control group • Indicationbias - Drug given to those at higher risk of outcome, so appears drug causes outcome Case control: odds ratio Odds ratio = ad/bc, the 'cross-product' ratio 95% Confidence Interval of Odds Ratio • Determined by sample size in each cell - Larger the size, the smaller the confidence interval • Interpretation of 95% confidence interval - If includes 1.0, then no association of drug use with effect - If greater than 1, effect more likely with drug use - If less than 1, effect less likely with drug use E N E DU. A. B NDU C. D Odds ratio = ad/bc Relative risk = a/(a+b) / c/(c+d) first row over second row If b>>a and d>>c, then OR approximates RR Based on OR of 6.3 (2.4-16.4), daily acetaminophen use was associated with...Increased risk of ESRD, as 95% confidence interval of OR exceeds 1.0 Potential flaws to many case-control studies, including confounding by indication - Recommendation for use of acetaminophen rather than NSAID in patients with renal impairment - Association in case-control study does not prove causation! How does diclofenac compare to other NSAIDs with respect to GI toxicity? • Garcia Rodriquez, Gastroenterology, 132:498, 2007, Risk of upper gastrointestinal complications among users of traditional NSAIDs and COXIBs in the general population. • Astra Zeneca supported study • About 1500 cases of UGIC selected from UK The Health Improvement Network database of patient records on GP office computers; well defined criteria for UGIC identification; 10,000 controls matched for age, gender and calendar year • Characterization of drug exposure as 'current', 'recent' or nonuse and duration of use by defined criteria, based on prescription records to avoid recall bias • Strategies to avoid information bias (by validation of UGIC diagnosis), confounding by indication, and misclassification of drug use (computer-based records of prescriptions for NSAIDs) Major findings of Rodriguez 2007 case-control study • Current use of tNSAID associated with 3-4 fold increase of UGIC with lesser risk from COXIB • Concomitant use of aspirin with the COXIB eliminated superior GI safety • Risk shown to be dose dependent • Risk greater in RA than OA patients, partly due to higher dose used in RA • Is acetaminophen likely to be effective? • If not, can she tolerate oral NSAIDs? - Is there a history of 'aspirin intolerance syndrome'? - What are GI, CV, renal risks in the patient? • Use PPI to reduce GI risk, if GI history • Consider CV risks of tNSAIDs and COX2 inhibitors, if CV history • Does the patient achieve a therapeutic effect after titration up to the maximum NSAID dose? • If not, consider other approaches - Combination of acetaminophen and NSAID, topical NSAID, steroids (intra-articular injections), opioids, duloxetine (5HT/NE reuptake inhibitor)
What molecular changes result in hypereosinophilia in coagulative necrosis? -Denaturation of cellular proteins (coagulation) increases eosin staining and decreased levels of cellular RNA reduce normal basophilia (cytoplasmic staining with hematoxylin) How are neutrophils recruited to areas of necrosis? - Ischemic injury results in release of cytokines and increased surface expression of adhesion molecules which recruit inflammatory cells.
Sections from the base of the papillary muscle at the point of rupture with advanced necrosis
Herb-drug interactions — Increasing data show the potential for herbal medicines to interact with prescription and nonprescription pharmaceuticals [82]. Several of these interactions have been documented to occur through case reports. Other interactions have been theorized through in vitro studies but not documented with case reports. Specific interactions of natural and alternative drugs with other medications may be determined using the drug interaction program (Lexi-Interact) included with UpToDate. This can be accessed from the UpToDate online new search tab or through the individual drug information topics, section on Drug interactions. Several systematic reviews identified herb-drug pairs that have been reported to interact based on clinical data or in vitro studies [83,84]. Warfarin was the most frequent pharmaceutical implicated and St. John's wort had the most drug-herb interactions [84]. Herb-induced alteration in the metabolism of cytochrome P450 enzymes was the most common mechanism implicated in herb-drug interactions.
Specific examples of documented herb-drug interactions include: ● The hyperforin component of St. John's wort induces the cytochrome P450 3A4 (CYP3A4) system, which metabolizes a number of drugs including protease inhibitors, cyclosporine, oral contraceptives, irinotecan, warfarin, and digoxin. Failure of antiretroviral therapy, transplant rejection, and contraceptive failure have been reported. In addition, St. John's wort may produce the serotonin syndrome when taken with other serotonergic medications. (See "Clinical use of St. John's wort", section on 'Herb-drug interactions'.) ● Ginkgo biloba has antiplatelet and antithrombotic effects and therefore has the potential to interact with anticoagulants such as warfarin, nonsteroidal antiinflammatory drugs (NSAIDs), and aspirin, leading to an increased risk for spontaneous hemorrhage and bleeding. (See "Clinical use of ginkgo biloba", section on 'Interactions'.) ● Concomitant ingestion of grapefruit juice and certain dihydropyridine calcium channel blockers may elevate the plasma concentration of the latter, possibly leading to hypotension [85]. Grapefruit juice increases the bioavailability of certain calcium channel blockers by inhibiting the CYP3A4 isoenzyme found in the liver and gut wall [86]. The result of this inhibition is that more drug is absorbed and plasma concentrations increase.
2. Be able to list the important mediators that cause increased blood flow
Steps in acute inflammation. There are three basic steps in acute inflammation, but this does not mean that the response moves in a linear fashion from one step to the next since the steps may occur nearly simultaneously. Many of the mediators exert an effect on each of these three steps. Step 1. Hyperemia - dilatation of blood vessels Hyperemia, or increased blood flow to the affected inflamed region, accounts for the calor (warmth) and rubor (redness) of acute inflammation. Increased blood flow occurs following vasodilatation of precapillary arterioles. Several mediators dilate arterioles. Stasis is the opposite of hyperemia and is the engorgement of small blood vessel with slowly moving cells Vasoactive amines: histamine and serotonin. These are usually the first mediators released. Histamine is stored in mast cells, basophils and platelets. It is released from mast cells in response to trauma or heat, immune reactions involving IgE, and the C3a and C5a fragments of complement (anaphylatoxins), leukocyte-derived histamine-releasing proteins, neuropeptides, and cytokines, such as IL-1 and IL-8. Histamine causes arteriolar dilation and increased venule permeability and is inactivated by histaminase. Serotonin is principally found in platelets, pre-formed, in the platelet dense body granules, and its effects are similar to those of histamine. Prostaglandins (vasodilation), thrombozan/leukotrienes (vasoconstriction), leukotrienes (permeability), LTB4HETE (chemotaxis). Arachidonic acid metabolites These metabolites are called prostaglandins, leukotrienes and lipoxins. Arachindonic acid (AA), a 20-carbon polyunsaturated fatty acid, yields derivatives called eicosanoids and is derived from the phospholipids contained in cell membranes. AA metabolites mediate many steps in inflammation including vasodilatation, listed in table 3. Nitric Oxide (NO) NO acts as a smooth muscle relaxant causing vasodilation especially when produced by endothelial cells. NO is synthesized from L-arginine and oxygen by nitric oxidase synthase (NOS) using NADPH as a cofactor. Inducible (iNOS) is found in macrophages and endothelial cells, the 'i' indicating that it is inducible by cytokines (IL-1, TNF, IFN-gamma) and products of bacterial breakdown Platelet activating factor (PAF): A lipid derived from cell membranes, PAF is produced by neutrophils, monocytes, basophils, endothelial cells, and platelets, through the action of phospholipase A2. The name was given since it causes platelet aggregation and activation. Bradykinin. Kinins are vasoactive peptides derived from plasma proteins, called kininogens. Factor XIIa converts prekallikrein to kallikrein, which cleaves a plasma glycoprotein to produce bradykinin. Bradykinin increases vascular permeability and causes contraction of smooth muscle, dilation of blood vessels and pain when injected into the skin.
7. Explain the beneficial effects of acute inflammation.
Tissue injury. In some situations the acute inflammation causes damage to nearby tissues. Many of the processes involved in killing the bacteria, such as the generation of highly active proteases and reactive oxygen intermediates, can induce damage to nearby normal tissue themselves. In an appropriate response, acute inflammation clears the pathogen or necrotic tissue without damaging normal cells and tissues. Outcomes of acute inflammation. The most ideal outcome is resolution of the acute inflammatory response and restoration of normal tissues and hemostasis. This in fact happens on a daily basis across the world where an acute inflammatory response resolves without sequela. However, in some situations the acute inflammation may progress to fibrosis and/or chronic inflammation.
• Describe transdermal and pulmonary drug delivery devices and their therapeutic advantages
V. Some Special Drug Delivery Systems A. Ophthalmic: Ocusert® is a reservoir of pilocarpine contained in a flexible polymer membrane; when placed within an eyelid pouch, the drug diffuses out through the membrane, maintaining miosis in patients with glaucoma for one week. B. Vaginal: NuvaRing® is a flexible plastic ring containing an estrogen and a progesterone that can be inserted into the vagina; the hormones diffuse out of the ring, enter the bloodstream for 3 weeks, and prevent ovulation; on removal menstruation occurs. C. Intrauterine: Mirena® is an intrauterine device that delivers low doses of the progestin, levonorgestrel, directly into the uterine cavity to provide contraception. Following insertion of Mirena®, a stable plasma level of levonorgestrel occurs after the first few weeks. Unlike oral contraceptives, plasma levels with Mirena® do not display peaks and troughs. Mirena® is indicated for intrauterine contraception for up to 5 years and is recommended for women who have had at least one child. D. Subdermal: Implanon® is a single, non-biodegradable, progestin-containing rod implant for subdermal use that is indicated for women for the prevention of pregnancy. The rod consists of a copolymer core containing the synthetic progestin etonogestrel surrounded by a copolymer shell. After subdermal insertion of Implanon®, the progestin is released into the circulation and is approximately 100% bioavailable. Implanon® is a long-acting (up to 3 years), reversible, contraceptive method. The rod must be removed by the end of the third year and may be replaced by a new rod, if continued contraceptive protection is desired. E. Intravenous: 1. Numerous devices for inpatient and outpatient delivery via syringe or catheter for controlled input rates with pumps. 2. Liposomes: spherical vesicles with an aqueous core and bilayered membrane structure of natural or synthetic lipids; from tens of nanometers to micrometers in size; can be tailored for delivering a drug trapped inside to a specific tissue; typically administered as iv infusion; applications in cancer chemotherapy, anti-fungal therapy and other indications. 3. Drug-coated stent: a slotted stainless steel tube inserted in a coronary artery, which releases a cytostatic drug such as paclitaxel to prevent restenosis of the vessel (Example: TAXUSTM Express2TM). F. Transdermal patches: 1. Advantages: a. Permits effective administration of drugs with very short half-lives. b. Permits administration of low doses, especially of drugs that undergo extensive first-pass inactivation in the liver. c. Simplifies self-administration by patients and enhances their compliance. d. Avoids problems associated with variable absorption from the gut. e. Avoids IV administration. 2. Determinants of skin permeability to drugs (via the stratum corneum): a. Oil/water partition coefficient of the drug b. Molecular weight (however, low frequency ultrasound has been used to enhance permeability to many drugs, especially large proteins) c. Solubility in water. 3. Representative types of transdermal systems: a. Reservoir: The drug is stored in a single compartment from which it migrates through a rate-controlling membrane to the skin surface. [Examples: Duragesic® (fentanyl, for the management of chronic pain); Estraderm® (estradiol, for estrogen replacement); Habitrol® and Nicoderm® (nicotine substitution patches). b. Matrix: The drug is uniformly dispersed through a polymer matrix from which it slowly diffuses to the skin surface. [Example: Nitro-Dur® (a brand of nitroglycerin patch)] c. Microseal: The drug is sealed within microcompartments, 5-50 μm in diameter, that are dispersed throughout a polymer. The drug is partitioned out of water at the surface of each compartment, and then diffuses through the solid polymer to the skin surface. [Example: Nitro Disc® (a brand of nitroglycerin patch)] G. Intranasal/buccal Routes (to pulmonary sites of action for improved drug selectivity) 1. Factors governing deposition of aerosols a. inertial impaction of particles in areas of non-laminar flow: particles > 10 μm will not reach alveoli b. gravity, especially for particles of 0.5 to 10 μm c. Brownian motion causes particles to remain in suspension and are exhaled d. 80% of submicronic particles remain in suspension and are exhaled e. patient factors (e.g., inspiratory flow rate, respiratory rate, tidal volume, airway diameter, and alveolar contents). 2. Delivery Systems a. Metered-dose Inhalers: A fixed dose of propellant containing suspended drug particles is released through a valve during a deep breath, although only about 12% of the measured drug dose actually reaches the alveoli. Preferred for bronchodilators and anti-inflammatory therapy, because side effects are minimized. [Examples: Atrovent® (ipratropium bromide, a bronchodilator for chronic obstructive pulmonary disease; COPD) and Azmacort® (triamcinolone acetonide, a steroid for asthma), and many brands of albuterol.] b. Nebulizers: i) In jet nebulizers, used chiefly in hospitals, a high flow gas shears liquid strands from a drug solution; when the strands hit a baffle they are fractured into drug-containing particles that are then inhaled through a mask placed over the nose and mouth. ii) Ultrasonic nebulizers, which can be used at home, expel particles from a "geyser" formed from a drug solution by generating ultrahigh frequency sound into a similar mask. Both kinds of nebulizers can be used with some of the same drugs that are used in metered dose inhalers. c. Diskus: a handheld plastic disk with mouthpiece that contains powdered formulations of drugs in double-foil blister strips; activation opens the blister and releases the drugs into the airway. [Examples: Advair Diskus® (fluticasone, an anti-inflammatory steroid for asthma and salmeterol, a bronchodilator for asthma)] H. Nanoparticle Drug Delivery: Current research in the field of drug delivery includes investigation of the application of nanometer-sized particles of varying composition as the delivery vehicle for therapeutic agents. This approach is designed to enhance the properties of drugs, such as improved distribution specifically to the drug target to increase drug selectivity. Liposomal formulations are one example, and the primary type among the more than two-dozen nanotechnology products that are currently approved for clinical use.
What pathologic process is ongoing? Thrombosis
What factors/pathways likely caused this reaction? Endothelial damage by bacterial toxins can lead to thromboplastin release and/or exposed collagen and activated platelets can activate factor VII through the extrinsic coagulation pathway.
Chemical antagonism
When the antagonist interacts w/ the agonist to render the agonist inactive E.g. Etanerecept, infliximab (bind TNF-a, block it from binding its rec and inducing immune response)
Which mediators are responsible for rebound tenderness in this case? Prostaglandins and bradykinin
Which mediators are responsible for fever in this case? IL1, IL6, TNF, and prostaglandins
alpha vs beta classification (based on potency of agonists and selectivity of antagonists)
a receptors: E > NE > Phenylephrine >> isoproterenol B receptors: isoproterenol > E >/= NE >> Phenylephrine
V. Analysis of the serum concentration data for chloramphenicol after its i.v. and oral administration suggests that:
a. The elimination half-life of chloramphenicol depends on the route of administration No; the elimination half-life is determined by the total clearance (ClT) and the volume of distribution, t1/2el = 0.693 Vd/ClT. ClT and Vd generally are the same for different routes of administration (please make sure that makes sense to you). So the elimination half-life is usually the same for different routes of administration. If the absorption half-life (t1/2abs) is shorter than the elimination half-life (t1/2el) , then the terminal portion of the log Cp vs. t curve after p.o. administration will parallel the curve after i.v. administration and in both cases are indicative of the elimination half-life, as shown in the top curve: But in cases where the elimination is very rapid, as with chloramphenicol, the terminal curves may not be parallel because the kinetics of decline after p.o. administration are indicative of the absorption half-life, not the elimination half-life, as shown below: Please return to Item V to find a correct answer. b. The absorption of chloramphenicol into the systemic circulation is incomplete, since peak concentration is lower after p.o. than i.v. administration No; your logic is not quite right. After administration of a drug by any route other than i.v., the peak concentration is determined by the absorption half-life, elimination half-life, the extent of absorption (bioavailability), the dose, and the volume of distribution. Generally, the elimination half-life and Vd are about the same regardless of the route of administration. But the slower the rate of absorption, the lower the peak concentration even when the entire dose is absorbed, i.e., when the bioavailability is 100%. Try Item V again. c. The absorption of chloramphenicol is complete, since the area under the concentration vs. time curve after the p.o. route (83 mg hr/ml) is about equivalent to that after i.v. administration (70 mg hr/ml)* Correct: To quantitate the percent of the dose absorbed into the systemic circulation, the bioavailability (F), you can measure the area under the curve of serum concentration vs. time (AUC) for the p.o. route and compare this value to the area generated after i.v. administration. This approach is the standard procedure for assessing the bioavailability of formulations of a drug for oral use that may differ with respect to factors such as disintegration time, dissolution rate, stability, etc. In this case, the AUCp.o. is 83 mg.hr/ml and the AUCi.v. is 70 mg.hr/ml, so the bioavailability appears to be 100%. Strictly speaking, 83/70 x 100% = 116% bioavailability. Theoretically, the bioavailability cannot exceed 100%. But this study was carried out in two dogs, each of which received the drug by only one route. AUC is determined by dose, bioavailability, and total clearance. Total clearance may have been slightly lower in the dog receiving the p.o. dose, in which case the estimate of bioavailability would be a little high. The preferred experimental design for studies of bioavailability entails administration of the same total dose of drug by both routes in each subject (cross-over design) with sufficient time between the doses to avoid possible drug accumulation or drug-induced changes in its own pharmacokinetics. This cross-over design minimizes differences in total clearance. Please look for another correct answer in Item V. If you have already found it, proceed to Item VI. d. The absorption of chloramphenicol after oral administration exhibited a lag phase and was not rapid in onset Yes; measurable serum levels were not detectable until 1 hour after the oral dose, and the peak concentration did not occur until 4 hours. The oral dose was administered in gelatin capsules. Possibly, capsule disintegration, dissolution of chloramphenicol powder, and emptying of the drug from the stomach into the small intestine affected the rate of chloramphenicol absorption. Since chloramphenicol is an uncharged molecule that appears to readily distribute into cells, it is unlikely that the rate-limiting factor in its absorption is passage of dissolved drug through the intestinal mucosa. Please look for another correct answer in Item V. If you have already found it and the comment to Item Va, which has a helpful figure, then time for a new challenge! Now try Item VI.
nasal decongestant drugs
a1 agonist - want to vasoconstrict to oppose the vasodilation that's causing all the yucky nasal symptoms phenylephrine pseudoephedrine
Phentalomine Antagonist a1 & a2 Prazosin Antagonist a1
a1-antagonists: treatment of hypertension, treatment of pheochromocytoma (administered before beta blocker), treatment of raynaud's disease to reduce vagospasm, treatment of heart failure, decreasing bladder smooth muscle tone to aid in BPH, antidote to a-agonist vasoconstriction postural hypotension due to inhibition of a1-mediated vasoconstriction; reflex tachycardia and mycardial ischemia, salt & water retention & peripheral edema; GI stimulation, inhibition of ejaculation
bladder fxns
accumulates urine-->a1 on sphincter contraction and B2 on bladder wall relaxation voids urine (M3 mediates sphincter relaxation and detrusor contracture)
example(s) of muscarinic agonist vs antagonist
agonist = pilocarpine antagonist = atropine, scopolamine
Mineralocorticoids
aldosterone; fludrocortisone replacement therapy for adrenal disorders
alternating current --> asphyxia
alternating current --> tetanic muscle spasm --> irreversible clutching severe --> spasm of chest wall muscle --> asphyxia
VII. Some understanding of the mechanisms by which a drug is cleared from the plasma into the urine can be acquired by calculating of the renal clearance. The renal clearance (ClR) indicates the volume of the plasma that must have been cleared of the drug in order to achieve the output observed in the urine. Recall your calculations of renal clearance of nutrients such as glucose in physiology. ClR (ml/min) = rate of renal excretion (amount/min) plasma concentration (amount/ml) (Note that usually the concentrations of a drug in serum and plasma are about the same.) ClR 70-kg human 16.5-kg dog Estimate for: Inulin 120 ml/min 50 ml/min GFR Para-aminohippuric acid 650 ml/min 200 ml/min RPF The renal clearance of chloramphenicol in the dog after i.v. administration is:
b. 10 to 35 ml / min Correct; Based on 0-2 hr urinary recovery: ClR = Excretion rate of drug = 55 mg / 120 min Cp at 1 hr 24.2 µg/ml =(0.019 mg•ml) •(1000 µg) µg•min *mg = 19 ml/min Based on 2-4 hr urinary recovery: ClR =17 mg / 120 min= 21.5 ml/min 6.6 µg/ml Note that your two estimates of ClR of chloramphenicol are very similar, as you would expect. Generally, the renal clearance is constant and not dependent on the dose of the drug or the time after drug administration. However, often experimental estimates of ClR may be quite variable. One cause of variability is incomplete collection of urine excreted during the study interval. Can you think of other sources of variability? Proceed to Item VIII.
ephedrine/pseudoephedrine Indirect Agonist/Central Stimulant-->Indirect acting Sympathomimetics
can directly stimulate a1+B1 releases NE; present in many "nutritional supplements"; pseudoephedrine is used as a nasal deongestant
infliximab structure, function
chimeric monoclonal antibody, MW 144,000 biologic agent (protein therapeutic) administered parenterally (not p.o.) function: Fab region selectively binds TNF-alpha, dampens immune response
Botulinum toxin
cholinergic nerve terminals; internalized into cytoplasm denervating protein toxin enzymatically degrades protein factors required for vesicle fusion and Ach release; produces presynaptic impairment and localized skeletal muscle paralysis antitoxin-->but does not reverse toxicity, only prevents botulinum toxin from entering nerve muscle weakness; difficulty eating/swallowing, paralysis of respiratory muscles, death
effect of cholinesterase inhibitors on non-depolarizing vs depolarizing muscle blockers
cholinesterase inhibitors: + depolarizing blockers (More ACh to desensitize rec.) - non-depolarizing blockers (More ACh to out-compete drug)
pralidoxime mechanism
cholinesterase regenerator to treat organophosphate poisoning (irreversible AChE inhibition) - esteric site on AChE bound by organophosphate, blocking activity - anionic site = free, pralidoxime binds here - pralidoxime then binds organophosphate changing its conformation, causing it to unbind - AChE function is restored efficacy in organophosphate tx = controversial
Hurler's syndrome (Mucopolysaccharidoses I) alpha-L-iduronidase dematan sulfate, heparan sulfate
connective tissues, RES, endothelial cells, smooth muscle cells, fibroblasts hunter's disease is MPSII and is XL-R inherited hepatosplenomegaly, skeletal deformities, valvular lesions, subendothelial arterial deposits (Mis); cloudy corneas
other anti inflammatory
cyclosporine, tacrolimus calcineurin inhibitor enzymatic activity of calcineurin is required for NFAT--->NFAT binds to promotor region in T-cell for IL-2 synthesis-->without NFAT binding, no T-cell replication organ transplants sirolimus rapamycin mTOR inhibitor blocks mTOR activity-->T-cell can't progress from G1 to S-phase organ transplants and coronary stents atabacept orencia prevents binding of B7 (on APC) to CD28 on T-cell; needed for T-cell activation increases risk of infection rheumatoid arthritis natalizumab integrin a4 antagonist prevents lymphocyte interaction with adhesion molecules on vascular regions of inflamed intestine MS and chrohn's
c. Cell arrangement: clusters, chains, pairs i. Determined by orientation and degree of attachment of the cells during cell division.
d. Biotyping i. Based on the presence or absence of specific biochemical markers, like: a. ability to ferment specific sugars. b. production of specific end products. c. relationship to oxygen. e. Serotyping/Immunoassays i. Based on detection of unique antigens using specific antibodies. ii. Advantages: a. Fast b. Can be used for organisms that can't be identified by biotyping. c. Can be used for organisms difficult or impossible to grow. d. Can be used to make a definitive identification, depending on the reference antibody used. f. Antibiograms i. Tests for susceptibility to different antibiotics. g. Phagetyping i. Tests for patterns of susceptibility to infection by bacteriophages.
iris dilation / constriction
dilation = mydriasis sympathetic NE to outer layer of muscle, contraction = pulls pupil open constriction = myosis (constricted word) parasymp ACh to inner sphincter layer, contraction = constriction
partition coefficient
drug concentration in oil vs water (measures how lipophilic the drug is)
asthma signature immune cell
eosinophils asthma attack = acute exacerbation of a chronic disease
Pompe's disease alpha-glucosidase glycogen
generalized involvement (heart and brain most problematic) dark glycogen granules in myocardium cardiac enlargement, progressive HF, weakness, neurologic symptoms, death in infancy guy from extrordinary measures
granulomatous inflammation
granuloma = at a minimum, *an aggregate of macrophages*, usually arranged concentrically around a pathogen or irritant only assoc w/ certain specific pathological conditions purpose = host can't eliminate w/ one cell; forms granuloma to get a bunch of cells to surround the insult to eliminate it together
principal mediators of vasodilation
histamine, prostaglandins (but those 5 vasodilators all do it: vasodilators can never be perfect: vasoactive amines, cox derivatives [prostaglandins, leukotrienes, lipoxins], NO, bradykinin, PAF)
vasodilation
histamine; prostaglandins (PGE2, PGD2) serotonin, prostacyclins (PGI2) ; NO; bradykinin, PAF at low concentrations
growth factor/cytokine receptors
hours protein phosphorylation after dimerization kinase linked receptor, single transmembrane domain, ligands bind extracellularly
2. Microscopic appearance a. Gram stain: Gram-positive vs. Gram-negative, Gram-variable
i. Influences choice of antibiotic—in general, Gram-positive bacteria are more susceptible to penicillin G than Gram-negative bacteria. Why?
pathogenesis of neonatal respiratory distress syndrome
immaturity of the lungs main defect = pulmonary surfactant leads to inc. surface tension, collapsed lungs, progressive atelectasis, and reduced lung compliance result = deposition of protein/fibrin-rich exudate in the alveolar spaces (hyaline membranes)
Gluck\=dexamethasone; predisoneGC selective
immunosuppresant effects; autoimmune disorders, organ transplants; immune cell malignancies like leukemias and lymphomas; psoriasis; UC an Crohns duration of action 36-72 hrs
which second messenger pathway do m1, m3, & m5 receptors use? what's special about m3?
inc. PLC activity, inc. DAG, IP3 m3 = "glandular" muscarinic receptor, predominantly responsible for glandular secretion, NO release in vasculature, bronchial smooth muscle contraction, bladder contraction, and sphinctor relaxation
a1 receptor: 2nd messengers and effects
inc. PLC, inc. DAG, IP3 - vascular, genitourinary smooth muscle = contraction - inc. TPR, dec. venous capacitance - intestinal smooth muscle = relaxation - radial muscle (eye) = contraction (mydriasis) - liver = glycogenolysis, gluconeogenesis
effect of charge on ability to get through cell membrane? how about reabsorbed through kidney?
ionized = can't pass through cell membrane; can't be reabsorbed acidic compound in alkaline urine = (-) charge; can't be reabsorbed basic compound in acidic urine = (+) charge; can't be reabsorbed
LB4
leuktrienes arachidonic acid metabolite via lipoxygenase pathway chemotaxis (of neutrophils?)
exceptions to the "oma" = benign rule
lymphoma melanoma mesothelioma hepatoma (all malignant)
principal mediators of tissue damage
lysosomal enzymes, reactive oxygen species
PGI2
metabolite of arachidonic acid via COX pathway; made by endothelial cells inhibits platelet aggregation; vasodilation
effects of systemic hypothermia
mild: 32-35*C (90-95F) - *hyper*ventilation - lethargy - vigorous shivering moderate: 28-32/82-90 - *hypo*ventilation - confusion - loss of coordination severe (<28 / <82) - unconsciousness - slow or no breathing - weak or no pulse
Niemann-Pick Disease
missing enzyme: *Spingomyelinase* accum material: *sphingomyelin* tissues involved: CNS and RES in spleen, liver, lymph nodes, and bone marrow *Type A Variant* - 75-80% of cases; severe infantile form w/ *extensive neurologic* involvement, marked visceral accum of sphingomyelin, progressive wasting, and *death by age 3* *Type B Variant* - Patients have organomegaly but *no CNS involvement* - usually survive into *adulthood*
how does more severe injury lead to more leakage? (exudate)
more severe endothelial damage - more cytokines, bacterial toxins inducing cytokines, leukocytes more retraction (causes by mediators) more leakage + adhesion molecule expression neutrophils extravasate more - more swelling
common lab tests in the chemistry lab
most involve the measurement of a chemical or a protein - blood gas, electrolytes, LFT, cardiac function, renal function, pancreas function, hormones, autoimmune disease, tumor markers, immunoglobulin, toxicology, therapeutic drug monitoring tests
ligand gated ion channels
ms lets in ions, leads to hyper/de polarization GABA-A receptor-->GABA binds and opens a chloride channel Na+ channel blockers (prevent an action potential)-->local anesthetics like lidocaine, benzocaine, cocaine Calcium channel blockers preventing release of internal calcium stores into cytosol-->heart muscle does not respond--->nifedipine, dilatiazem
pilocarpine
muscarinic agonist (parasympathomimetic) - no nicotinic effects - some selectivity for salivary glands - used orally to treat xerostomia - used topically to treat glaucoma
RDS
neonatal respiratory distress syndrome - commonly observed in pretemr infants, male gender, and C section --> c section because normally inc. in glucocorticoids triggers inc. surfactant production -- c section = lacks that GC release - estimated of 24,000 cases of RDS annually in US - physical exam = dyspnea, fine rales heard on both lung fields - maternal history of diabetes (elevated fetal insulin)
AChE inhibitors
neostigmine physostigmine ___ neostigmine = - *no* CNS penetration (quaternary amine) - tx of Alzheimer's, myasthenia gravis - accelerates recovery from nondepol muscle relaxants (by inc. ACh to outcompete nondepol) - tx of post surgical paralytic ileus - tx of urinary bladder atony - antimuscarinic antidote physostigmine = penetrates CNS, drug of choice to treat *atropine poisoning*
granulocytes
neutrophils basophils eosinophils aka polymorphonuclear leukocytes (PMNs) short lived, non-recirculating (get to site of infection and die there)
NO
nitric oxide, vasodilator => L-arginine + oxygen 3 isoforms: 1. constitutive (always present) 2. inducible (@ inflam) 3. endothelial (only @ endothel) Activities: - vasodilation (relaxes sm muscle) - inhibits cellular components (e.g. platelet aggregation, WBC recruitment) - microbicidal (antimicrobial)
Acetaminophen Tylenol Nonopoid, nonncarcotic analgesic agent reversible CYCLOOXYGENASE activity in the CNS
no platelet effect; GI toxicity; no anti-inflammatory effect (loses effectiveness in the presence of peroixides found in sites of inflammation)
Met-Enkephalin u/d agonist
peptide==>none for clinical use
B3 receptors
present in adipose tissue, promote lipolysis
pain
prostaglandins, bradykinen
blood bank lab tests
provide products for transfusion (pRBC, PLT, FFP) and perform tests that ensure safe transfusion (type, screen, crossmatch) some blood banks perform blood replacement procedures (plasmapharesis and red cell exchange) also some blood banks have a blood donor center
succinylcholine
quaternary ammonium w/ fixed positive charge won't get through cell membrane; can diffuse between endothelial cell gaps and can get into interstitium, but CAN'T get into cells
Naloxone u antagonist giving nalaxone can cause precipitated abstinance or rapid, dangerous withdrawal
rapid redistribution; patient may become renarcotized overdoses
ROC curve
receiver operator characteristic curve plots the true positive rate (sensitivity) vs the false positive rate (1-specificity) and is a graphical representation of finding the best cut off (where sensitivity and specificity are maximized)
dopamine
specific endogenous D1 agonist / neurotransmitter B1 > a1
F_ab mediated elimination
specific, saturable mAb enters target cell by rec-mediated endocytosis and undergoes intracellular catabolism
Gaucher's Disease glucocerebrosidase sphingolipid-->glucocerebrosides
spleen, bone, liver, neurons in CNS crinkled tissue paper; huge cytoplasm Type 1-adult, spleen and skeletal involvement, reduced enzyme, slightly decreased longevity; Type 2-infantile, cerebral, no enzye, death; Type 3-intermediate (develop CNS in 2-3rd decade) hepatomegaly (2-3x), splenomegaly (up to 15x), thrombocytopenia (excessive bruising and bleeding), fatigue, low WBCs, bone crisises due to insufficient circulation, erlenmeyer flask deformity enzyme replacement, BM transplant, splenectomy, blood transfusions, joint replacement, gene therapy
SIDS
sudden infant death syndrome (SIDS) - *unknown cause* - death *under 1 year* of age which remains unexplained after a thorough case investigation, including complete autopsy, exam of death scene, and review of clinical history - autopsy usually fails to provide a clear cause of death
positive predictive value
the probability that a positive rest result predicts the patient has the disease PPV = TP/(TP+FP) how many of the positive test results are actually positive?
linearity
the reportable range for a given test that a lab feels comfortable in reporting the manufacturer will recommend a reportable range, however the lab should also have some kind of sense of range reported is accurate hence sometimes lab results may be reported as "greater than" or "less than"
TXA2
thromboxin Metabolite of arachidonic acid; made by platelets stimulates platelet aggregation; vasoconstriction
TPA structure, function
tissue plasminogen activator large molecule drug - protein w/ MW 70,000 administered parenterally (not p.o.) doesn't travel across membranes; stays in plasma to lyse clots
transudate vs exudate
transudate = - fluid that passes due to hydrostatic pressure early in the inflam process (leaks out; always happens naturally because oncotic pressure never fully balances) - *low* content of cells and proteins - *spec. gravity <1.015* exudate = - a fluid that escaped from the blood vasculature usually as a result of inflammation - *high* protein and cell content - *spec. gravity >1.015*
TNF & IL-1
tumor necrosis factor - important cytokine for both acute and chronic inflam - local concentrations higher than systemic - TNF inhibitors dramatically improve outcomes in chronic inflam conditions (but can't go off them) e.g. etanercept, infliximab (antibodies to TNF, bind it before it can bind to TNF rec; immunosuppressive) ___ interleukin 1 - important cytokine for both acute and chronic inflam - local concentrations usually higher than systemic (like TNF) - overlapping functions w/ TNF
platelet activating factor
type of vasodilator => leukocytes, mast cells, endothelial cells, platelets effects: - platelet aggregation - low levels = vasodilation - high levels = constriction - bronchoconstriction - leukocyte oxidative burse (energizes leukocytes to kill) - leukocyte adhesion, chemotaxis, degranulation
validation
validation - whenever bringin on a new test/instrument, validation has to be performed to compare the new with either the previous or a "gold standard"
a1 agonist side effects
vasoconstriction, ischemia hypertensive reactions - cerebral hemorrhage rebound nasal congestion
• A 25 year old woman felt ill with weakness and loss of appetite 6 weeks after a visit to Costa Rica as part of a rain forest research survey team. • She noticed yellow sclerae and visited a gastroenterologist. • Physical examination revealed mild jaundice, and a slightly enlarged and tender liver.
• Describe the microscopic anatomy of the liver lobule • Summarize the morphologic and molecular features of hydropic degeneration, necrosis, and apoptosis in the context of acute viral hepatitis. • Relate laboratory test results to these morphologic and cellular abnormalities. • Explain key differences between coagulation necrosis and apoptosis.
Acute Inflammation:
-A patient with acute inflammationPneumonia. Leukocytes found in Buffy coat. Granulocytes like NP, BP, EP: short lived nonrecirculating. -Monocytes in periphery, macrophage in tissue. Microglia in CNS< Histiocytes in CT, Kupffer cell in liver. Host response to injury or insult Infections Trauma Loss of blood - infarct (heart attack) Vaccinations Or - Immune reactions with blood flow Lasts hours to days. Neutrophils - hallmark inflammatory cell - part of innate immune system If you see neutrophils think acute inflammation Mediators of acute iflammation: made by preformed granules or de novo. Plasma protein derived present in inactive form or made in liver. -Mediators are Stimulate other cells Release secondary effector molecules Amplify or oppose given response Quickly destroyed or removed Activities in time and space are limited STEP OF ACUTE INFLAM 1. Blood vessel dilates to increase flow (Hyperemia in eyes) 2. Microvascular changes allow proteins and cells to leave the blood vessel 3. Emigration, accumulation and activation of leukocytes Vasodilators 1. Vasoactive amines (histamine, serotonin) 2. Cycloxygenase froma arachidonic acid (PG12), PGE2, PGD2, Prostacyclin. 3. NO 4. Bradykini 5. PAF (at low, at high PAF. causes vasoconstriction) 1.Vasoactive amines His/Ser are earliest mediators, preformed in granules, mast cell/platelets, histamine stimulated by trauma, cold, heart, binds ab to mast cells, C3a/C5a anaphylatoxin, substance P neuropeptides, dilates arterioles and increases permeability. Mast cell degranulation using allergen, heat, neuropeptide stimulus. 2. Cycloxygenase froma arachidonic acid (PG12), PGE2, PGD2, Prostacyclin. AA is a 20c pollyunsat FA phosphilids in cell membrane makes: prostaglandins, leukotrienes, and lipoxins. Glucocorticoids inhibit phospholipase so reduces the production a bit. COX-1/COX2 inhibit CO reducing just Prostaglandings and thromboxane. 3. Platelet Activating Factor is derivced form phsopholipids from leukocytes, mast cells endothelial cells, platelets, causes vasodilation in low levels, platelet aggeregation, bronchocontriction, leukocyte oxidative burst, leukocyte adhesion,c hemotaxis, and degranulation. 4. Nitric Oxide - NO: Synethesized from L-arginine + oxygen Constitutive, Inducible, or Endothelial isoforms. Vasodilation rleaxing SM, inhibit cellular components like PA WBC recruitment, microbicidal. 5. Biologically active proteins: Insulin, complem ent, coagulation proteins, proteolytic cleavage. Prekallikrein using Factor XIIa and HMWK Kallikrein makes Bradykinin a nonapeptide to increase vascular permeability, increase contraction of non-bv SM, dilate blood vessels, pain! Cell Derived Histamine, serotonin Cyclooxygenase products Nitric Oxide Platelet Activating Factor Plasma protein derived Bradykinin Most have additional biological activities Transudate: Fluid due to early inflam or hydro forces low protein <1.015 Exudate: Escames w high proteina nd high cell: +1.015. Effusion The escape of fluid into a defined cavity. Can be transudate or exudate. Edema The accumulation of fluid into the interstitium of tissues or alveolus. Can be transudate or exudate. Pulmonary Edema Types of Exudates: • Serous: Contains few cells. Clear fluid. Suggests mild vascular injury. • Purulent: Many inflammatory cells. "Pus" • Hemorrhagic: Contains red blood cells. Implies capillary damage. • Fibrinous: Exudate with a layer of fibrin deposited onto serosal surface. PLASMA LEAKAGE MEDIATORS: -Retraction of endothelial cells Histamine *Leukotrienes* Nitric oxide Bradykinin *Substance P* -Vasodilatation i.e. exert dual effects Histamine *Prostaglandins* Nitric Oxide Bradykinin Fibrinous exudate Bread & Butter Pericarditis Injury to endothelial cells Cytokines Bacterial Toxins (may be indirect by inducing cytokines) Leukocytes Leakage of Plasma Proteins Adhesion molecule expression AND Extravasation of neutrophils Leakage benefits: Plasma proteins are important - Kill invading pathogen (IgG FcyRI Fc kill) - Remove necrotic tissue Accumulate inflammatory cells PAMP DAMP TNF IL-1: 1. Margination 2. Rolling - Selectins & integrins 3. Tightadhesion - Integrins 4. Migration across vessel wall Adhesion Molcules: Pselectin - SLX RollingPMT Eselectin -SLX RA PMT Glycam1 -L selectin R PM ICAM-1 CD11/18 AdArMig PML VCAM-1 VLA-4 Int Adh EML Neutrophil chemotactic factors: 1. Bacterial products 2, C5a 3. LTB4 4. IL-8 CXC chemokines 5. PAF Chemotactic Cytokines • Chemoattractants for leukocytes • CXC - An amino acid between two cysteines. - Major neutrophil chemoattractant and activator • CC - No intervening amino acid - Attract monocytes and lymphocytes Vascular effects o C3a and C5a (anaphylatoxins) o Release histamine from mast cells o Vasodilation o Increased permeability C5a o Chemotaxis, esp o neutrophils, o Activation of lipoxygenase pathway of arachidonic acid o C3b: opsoninizes bacteria for phagocytosis Biological Activities of Inflammatory Mediators: Vasodilation: Histamine/Prostaglandins Increased vascular permeability: Histaminr, Serotonin, C3a, C5a, Leukotrienes C4, D4, E4 Chemotaxis, recruitment, activation: TNF, IL-1, chemokines, C3a, C5a, LTB4 Fever: TNF, Il-1,IL-6,Prostaglandins Pain: Prostaglandins, Bradykinin Tissue damage: Lysosome enzsymes, ROS Systemic Effects of Acute Inflammation 1. Fever: TNF, IL-1, IL-6, Prostaglandins on hypothalamic thermoregulatory center. 2. Leukocytosis: CSF increase leukocute release from bone marrow. 3. Tachycardia rapid heart rate 4. Tachypnea Rapid respiratoru rate 5. Acute phase reactants from hepatocyte release via IL-6. SOB: leakage of plasma proteins Green sputum: neutrophil degradation of bacteria Fever and malaise: CO metabolises and cytokines Purpose of acute inflammation Eliminate pathogen (s) Remove necrotic tissue Steps to accomplish these goals 1. Recognition 2. Removal 1. Extracellular traps 2. Intracellular killing a) Phagocytosis b) Phagolysosome c) Proteases d) Reactive oxygen and nitrogen Neutrophil Extracellular Traps: Product of a dying neutrophil Composed of strands of chromatin and proteins Bacteria stick to the chromatin Proteins have anti-microbial activity Phagolycosome: destroy gram negative rod Oxygen metabolites: Oxygen derivatives • Superoxide: O2• • Hydrogen peroxide: H2O2 • Hydroxyl radical: OH• • Main source • Leukocytes iNOS + Arginine + OH* + NADPH + Phagocyte Oxidase + MPO = OCL OH OONO kill G- rod. Tissue injury: more inflammation, release ROS, release protease, coagulation. Outcomes of acute inflammation 1. Complete resolution 2. Fibrosis 3. Chronic inflammation
Discuss the concept of differentiation as it applies to tumors arising from the various epithelial cell types (squamous, glandular)
5. Differentiation: refers to the extent to which parenchymal cells of a particular growth resemble the normal cells in the tissue or organ from which the growth arose both morphologically and functionally. "Well" differentiated tumors are composed of cells that closely resemble the normal cells of the parent organ/tissue while "poorly" differentiated tumors have a more primitive appearance. "Moderately" differentiated is somewhere in between. For glandular neoplasms the degree of differentiation is determined by the ability of the tumor cells to form welldefined glands (well differentiated) or to occur in solid sheets with minimal gland formation (poorly differentiated). Moderate differentiation is somewhere between. For squamous epithelial tumors the degree of differentiation is dependent on the extent of keratinization Neoplasms: There are two basic divisions of neoplasms, benign and malignan: Benign neoplasms: an abnormal growth of cells that cytologically closely resembles the normal cells of the tissue from which the tumor arises. These neoplasms tend to remain localized, are generally well circumscribed, do not spread to other sites, are generally amenable to surgical excision and are usually associated with a good prognosis. Nomenclature: benign tumors are often designated with a suffix "oma". Thus a benign tumor of fibroblasts is a fibroma, a benign tumor of smooth muscle cells is a leiomyoma, a benign tumor of chondrocytes is a chondroma etc. The nomenclature of benign tumors of epithelial cells is slightly more complex: a) Benign tumors of gland forming cells (or cells from glandular organs) are called adenomas. In some instances the cells may form tubular (gland-like) structures (colon, kidney, thyroid) while in other situations the cells may be present in solid sheets (adrenal cortex, liver). In cases where large cysts are formed (typically ovary) the term cystadenoma is used. b) Benign tumors of squamous epithelium can be called epitheliomas or papillomas (when exophytic, branched). In special situations additional terms, such as verrucae (wart) or condyloma are used to describe benign squamous epithelial growths. c) The term polyp refers to a tumor that projects above a mucosal surface and can be glandular (colon) or squamous (vocal cord). d) In some instances a benign tumor may include both epithelial and mesenchymal elements (mixed tumor [pleomorphic adenoma] of salivary gland, fibroadenoma of breast). e) Benign tumors that arise from germ cells (gonads, mediastinum) give rise to tumors composed of different germ layers (skin, neurons, glial cells, thyroid, intestinal cells, cartilage) and are called teratomas. Teratomas may be benign, immature or overtly malignant. f) A hamartoma - is not strictly a neoplasm but results from a disorganized collection of normal tissue. . While, by definition, benign tumors are slow growing, localized growths associated with a good prognosis, some benign tumors can be life threatening. a) A benign tumor of the meninges (meningioma) may exert increased pressure on the brain and compromise function. b) A small benign tumor of ependymal cells in the third ventricle (ependymoma) may block CSF flow and lead to hydrocephalus. c) A benign endocrine adenoma may secrete excessive hormone (insulinoma of pancreas producing sudden hypoglycemia) d) A gastric leiomyoma may ulcerate and lead to serious hemorrhage.
Nifedipine, Diltiazem
Ca++ channel blockers --> inhibit VG Ca2+ channels; no release of intracellular Ca2+ stores into cytosol
Select Economic Aspects of Drug Use
Medicine spending below healthcare spending growth for 5 of the last 10 years $374 BN industry Government health care spending crowds out other taxpayer-funded priorities 58% $457 billion was spent on prescription drugs in 2015, comprising 16.7% of total healthcare spending. ASPE also broke down the drivers of increased drug spending, finding: - 10% was due to population growth; - 30% to increases in the number of prescriptions per person; - 30% to economy-wide inflation; - 30% to changes in composition of drugs prescribed towards higher-priced products or price increases for drugs that drove the average price increase above general inflation Increasing Utilization of Medications all ages but mine Specialty" Pharmaceuticals Spending 1/3 spending oncology autoimmune HIV MS VH other Drug Pricing Dominates the News - Still, and More to Come PHARMALOT SEPTEMBER 19, 2016 Sarepta to charge $300K for Duchenne drug. 'We tried to be reasonable,' CEO says Forbes Pharma and HealthCare August 21, 2016 Why Did Mylan Hike EpiPen Prices 400%? Because They Could The Wall Street Journal January 10, 2016 Drugmakers Raise Prices Despite Criticisms: Pharmaceutical companies cite high cost of research as reason for price increases Pharmaceutical Industry ■ ■ ■ ■ ■ Good Guys? Economic juggernaut Cure for Chronic Hepatitis C infection Disease modifying therapies for Cystic Fibrosis, many immune diseases Advances in treatment of cancer Bad Guys? ■ Price increases beyond inflationary factors ■ Accusations of Price gouging, cornering the market ■ CEO compensation ■ Drugs in United States costing significantly more than in other countries LantusTM Price Increases Oct 2012 - Nov 2014 188% Price Increase Nov 2014 - Jul 2016 O% Price Increase Insurance Who Pays - How? ■ ■ Pool of money to provide benefits to members of the pool (beneficiaries) Cost-sharing strategies: - Premiums • Employer ● Individual - Deductibles • Out-of-Pocket (OOP) payments before benefit kicks in - Co-Insurance • Percentage OOP payment for service - Co-Pays • Fixed dollar amount OOP payment for service Pharmacy Benefit Cost-sharing ■ Co-Pays - Tier 1 - Tier 2 - Tier 3 - Tier 4 Generics $10 Preferred Brands $25 Non-preferred Brands $50 Specialty Pharmacy 20% • AKA co-insurance Pricing / Cost / Value / Affordability ■ Price vs. Cost - Price - Sum of money asked or given - Cost - Value of resources consumed ■ List Price and Discounts ■ Value - Is it worth it? - Cost Effectiveness; Willingness to Pay ■ Affordability - Can we afford it? - Feasible; Sustainable MassHealth Overview (FY17) ■ Members - ~1.98 Million Total Including: - Medicaid Contracted Managed Care Organizations - Primary Clinician Care Plan ("in-house" managed care plan) - "Fee-for-Service" Members (Mostly Other Insurance) • Medicare Dual Eligible members • Members with commercial insurance • "True" FFS members ■ Dollars - - - State Budget - $39.15Bn MassHealth Budget - $15.4Bn • Plus Connector, Health Safety Net, other Pharmacy Spend - MCOs (~$1B) + PCCP/FFS ($654Mm) • Plus Dual Eligibles - Medicare Part D Clawback ($372Mm) BUSM Disease and Therapy August 1, 2017 MassHealth Rx Spending $1,200 MassHealth Pharmacy Spend FY 2000-2017 Retail Pharmacy, Fee-for-Service (Non-MCO) lower Brand - Generic Utilization Rate 2002 - 2016 % Claims December 2002 MassHealth is primary payer Avg claim vs generic claim omeprazole = most amount Harvoni - 22k Budget Impact Model: Axicabtagene ciloleucel $300,000 8 to 20 $2.4 to $6 million/year* ■ Approval of federal 1115 waiver ■ Development of Accountable Care Organization (ACO) Models - Model A: Integrated entity includes both the ACO provider and health plan (MCO) - Model B: ACO providers contract directly with MassHealth, which remains the insurer - Model C: ACO providers contract directly with MCOs Deploy ACO Pilot project - PCC Plan only (Dec 2016) - Boston Accountable Care Organization - Community Care Cooperative - UMass Memorial Healthcare, Inc - Partners Healthcare Accountable Care Organization - Children's Hospital Integrated Care Organization - Steward Medicaid Care Networ MassHealth Priorities Restructuring / Payment Reform ACO models: goals and principles ■ Materially improve member experience- ACOs expected to innovate and engage members differently ■ Strengthen the relationship between members and Primary Care Providers (PCPs) by attributing members to an ACO through their selection of a PCP ■ Encourage ACOs to develop high value, clinically integrated provider partnerships ■ Partner with MCOs, with expectations for MCOs to help administer the ACO program and work with providers in strengthening provider-based care management ■ Increase BH/ LTSS integration and linkages to social services in ACO models Value Frameworks for Medication ■ Analytical tool to measure the value of medications and determine potential impacts on healthcare system ■ Five Models: - - - - - American College of Cardiology / American Heart Association American Society of Clinical Oncology Memorial Sloan Kettering Cancer Center National Comprehensive Cancer Network Institute for Clinical and Economic Review Value and Affordability (ICER Definitions) ■ Care Value - Comparative clinical ■ Affordability - Short-term budget impact - Project uptake rate and competitive products - Benchmark budget impact ≤ GDP growth rate +1% ICER = Institute for Comparative Effectiveness Research effectiveness - Incremental cost- utility ($100- 150K/QALY) - Benefits / disadvantages - Other contextual issue Pharmacoeconomics ■ Identifying, measuring, and comparing the costs, risks, and benefits of programs, services, or therapies and determining which alternative produces the best health outcome for the resources invested. - Cost-Minimization Analysis - Cost-Benefit Analysis - Cost-Effectiveness Analysis - Cost-Utility Analysis The Generic Cliff Zyprexa - olanzapine Wholesale Acquisition Cost 95% REDUCTION Cost-Benefit vs. Cost-Effectiveness COST-BENEFIT COST-EFFECTIVENESS ■ ■ ■ ■ Uses dollar values for outcome measurements Maximizes benefit of investment Assumes limited resources Compares programs with different objectives ■ Use non-monetary outcome measurements ■ Minimizes cost of program ■ Assumes adequate resources ■ Compares programs with the same objective Sample Comparison Using Different Benefit- Cost Approaches Cost-Effectiveness Analysis Which drug is more cost effective for lowering blood pressure? Average Blood Pressure Cost/Month Reduction Drug X Drug Y $35 12mm Hg $50 15mm Hg Cost Effectiveness Ratio: Drug X: Drug Y: $35 / 12 = $2.91 / mmHg $50 / 15 = $3.33 / mmHg Cost-Utility Analysis Which chemotherapy regimen is preferred? Increased Lifespan of Life Average Quality Adjusted Life Years Gained 1.8 1.6 Quality Chemotherapy Regimen 1 * Chemotherapy Regimen 2 * 2 years 0.9 0.4 4 year * Assumes regimens are same cost The Medication Use Process Adjust MONITOR All PRESCRIBE Physician DISPENSE Pharmacist 40 ADMINISTER Nurse / Patient 1 IN 10 GETS DFRUG ERROR ■ Drug-related morbidity and mortality estimated to cost $76.7 billion annually in the ambulatory setting in the USA - 8.76 million hospitalizations (28%) @ $47.4 billion - Long-Term Care Admissions - Physician and Emergency Department Visits - Additional Prescriptions - 199,000 Deaths Governor declares an emergency on opiate abuse DEATHS INCREASE AND OPIOPD SOLD INCREASES AND ADMISSIONS Management strategies • Dose limits (120 MME as of March 8, 2016) • Duplicate short-acting and long-acting • Quantity limits • High dose short-acting monotherapy restriction Therapeutic Class Management (TCM) Workgroup • Reviews outlier member cases • Outreach to prescriber regarding treatment plans • Referrals to fraud, waste and abuse Recent legislation • Initial prescription day supply limits ■ ■ ■ Up to 50% of patients do not adhere to medication regimen Adds $100B in avoidable hospitalizations 89,000 premature deaths Increases total cost of care in U.S. by $290B Drug Expense Management ■ Follow the money... ■ Distribution of Dollar Revenue from a Retail Prescription - Manufacturer $0.76 - Pharmacy $0.22 - Wholesaler $0.02 Basic Strategies to Manage Pharmacy Costs ■ Control the Payment Rate - Manage the Reimbursement Rate to Providers ■ Control the Volume - Manage the Number of Units • Prescriptions or Tablets ■ Control the Utilization - Manage Selection of Drug Formulary (Preferred Drug List) - GenericEquivalence - TherapeuticEquivalence - PatientIncentives ■ Drug Use / Treatment Guidelines ■ Disease State or Care Management ■ Restrictions (e.g., Prior Authorization) ■ Drug Use Evaluation / Review - Prospective 49 BUSM Disease and Therapy August 1, 2017 - Retrospective
In this study, what can be said about the risk (i.e., probability) of Reye's syndrome among children treated with salicylates?
The risk is elevated, but the absolute risk can't be estimated since this was a case-control study.
Radiation Injury
[29] Two types of radiation, electromagnetic and particulate, can cause injuries. Electromagnetic radiation is generated by waves that span the electromagnetic (EM) spectrum, from longer wavelengths with lower frequency and lower energy to shorter wavelengths with higher frequency and higher energy. At the lower-frequency end are the radio frequency (RF), used in communication applications such as radio, TV, cell phones, WiFi, and radar; followed by the microwave frequency, used for cooking in microwave ovens, as well as in some cell phone towers. Next is infrared radiation (IR), which is felt as heat and is the most encountered type of radiation; and visible light. Ultraviolet radiation (UVR), with still higher frequency, comes from the sun. X-rays are generated by firing electrons at a metal target. X- rays are used in biomedical applications for imaging in radiographs and computed tomography (CT) scans - computer-processed combinations of many X-ray images; and for solving molecular structures in X-ray crystallography. And gamma rays, at the highest-frequency end of the EM spectrum (originating from eruptions on the sun's surface), are used for cancer-cell killing in therapy, and for sterilization of medical equipment that cannot withstand heat. Particulate radiation arises from nuclear decay, and comprises alpha and beta particles and neutrons. Alpha particles, used in smoke alarms, consist of 2 protons & 2 neutrons. Beta particles, used in paper & aluminum foil production, consist of electrons. And neutrons, react with the nuclei of other atoms to generate new isotopes, which may be radioactive. X-rays and gamma rays, and alpha, beta and neutron particles are ionizing forms of radiation - inducing formation of free radicals by molecules with which they collide. Ionizing radiation is mutagenic, and both ionizing radiation and the UVB part of ultraviolet radiation are carcinogenic. [30] Ionizing radiation can lead to mutations both directly by inducing free radical formation in the DNA and indirectly by inducing other free radicals, especially reactive oxygen-species, which then ionize DNA. If the DNA is not repaired, the mutations may lead to cell death, or contribute to carcinogenesis (initiation of cancer formation) or teratogenesis (promotion of congenital malformations in an embryo or fetus). [31, 32] Different tissues have different sensitivity to ionizing radiation, with rapidly dividing cells, including lymphoid cells, hematopoietic cells, germ cells, and GI epithelium, showing the highest sensitivity, dying when exposed to less than 25 Sievert. [(Sv = unit of equivalent biologic dose of radiation = Gray (Gy, energy absorbed by a tissue per unit mass) x the relative biologic effectiveness of the radiation]. Skin, blood vessels, squamous epithelium, and growing bone and cartilage have moderate sensitivity to radiation. And kidney, muscle, brain, endocrine organs, and adult bone and cartilage have the lowest sensitivity, dying only at radiation doses higher than 50 Sv. Injuries caused by ionizing radiation include vascular damage, inflammation, and fibrosis, especially fibrosis of the lungs which, when severe, is referred to as radiopneumonitis. In radiopneumonitis, the alveolar spaces are largely filled with connective tissue. [33] Ultraviolet radiation consists of UVA, UVB and UVC. UVC (the most energetic) is the most harmful but it is absorbed by the shielding stratospheric ozone layer (a highly beneficial function). Both UVA (the least energetic) and UVB reach the earth and are harmful, although most solar UVB radiation is absorbed by the atmosphere so only a fraction reaches the earth. UVB can cause non-neoplastic and neoplastic damage to the skin, whereas UVA contributes to the non-neoplastic damage. Non-neoplastic changes manifest as sunburn, an acute one-time excessive exposure to UV radiation, with erythema (reddening of the skin), pigmentation (tanning) and depletion of Langerhans cells (dendritic cells in the skin), all reversible changes. However, long-term cumulative exposure to UV radiation results in irreversible degeneration of skin elastin and collagen, leading to wrinkles and leathery skin. Long-term UV exposure can also increase the risk of cataract formation (a clouding of the eye lens that typically occurs with aging), by triggering harmful oxidative reactions. In addition, UVB radiation can cause dimerization of pyrimidines in DNA, resulting in transcriptional errors, which can lead to cancer. ] Electromagnetic field (EMF) radiation from radio-waves associated with cell phones and cell phone towers, and microwaves from microwave ovens and some cell phone towers, has given rise to safety concerns. Indeed, high EMF radiation levels do cause burns and possibly cancer. But cell phone towers are restricted to specifically designated sites and routine use of microwave ovens and cell phones appears to pose little or no health risk. However, prolonged and heavy use of cell phones may be associated with increased risk of brain cancer.
Stages of [nondepolarizing muscle] Block
1. Fasciculation (from nonsynchronous muscle activation) 2. Phase I Block (depolarizing) --> leads to desensitization & VG Na+ inactivation; muscle exhibits flaccid paralysis 3. Phase II Block (desensitizing) - nicotinic ACh rec. activation --> desensitize and inactivate channel - muscle repolarizes but continues to exhibit flaccid paralysis due to non-responsiveness of ACh Rec.
What pathologic process is present?
Acute inflammation with acute inflammatory exudate partially replacing the mucosa. Neutrophils infiltrating the muscular wall What is the cause of this inflammatory reaction? Luminal blockage (fecalith or foreign body) causes bacterial overgrowth with resultant inflammation and infection.
What type of receptor do cytokines use?
Kinase linked receptor (growth factors, too)
Aspirin
Salicylate Irreversibly inactivates COX (1 and 2)
Describe the basic steps involved in the process by which new drugs become available for professional use. their intended audiences.
The Prescription Drug User Fee Act (PDUFA) of 1992 authorized the FDA to collect fees from applicants seeking approval of certain NDAs. Because the fees are proportional to the time spent reviewing applications, the act encourages manufacturers to submit more data at the beginning of the process, rather than respond to potentially multiple requests for more data from the FDA. This legislation was reauthorized in 1997 and 2002 through the FDA Modernization Act, which continued measures to shorten review times and permitted manufacturers' advertising of unapproved ("off-label") uses of approved drugs under certain conditions. The 2007 reauthorization improved the FDA's drug safety surveillance system and increased resources for review of TV drug advertising. In 2002 a new act was passed by Congress to improve knowledge of the appropriate use of drugs in infants and children through clinical trials in pediatric patients. The Best Pharmaceuticals for Children Act (BPCA) extends the market exclusivity of a patented drug in response to sponsors' submission of data from pediatric studies. The Dietary Supplement Health and Education Act of 1994 exempts products marketed as dietary supplements from FDA review for either efficacy or safety, or even purity. For example, controversy surrounds the marketing of melatonin for insomnia and jet lag because there is no need for controlled studies of its efficacy or safety, and many brands include unidentified impurities. However, food additives such as Olestra are regulated, especially for safety. The Medical Device Amendment (to the 1938 FDA act), passed in 1976, requires FDA approval of a wide range of non-drug devices and materials, based on studies of their efficacy and safety in animals and human subjects. B. Definition of "New Drug": Although the word "drug" is used in many ways, it is, broadly speaking, a substance or combination of substances used in the diagnosis, prevention, or treatment of disease, or for restoring and/or maintaining health (although at this writing vitamins are not included as drugs by the FDA). "Drug" sometimes refers to the specific active ingredient in a combination upon which the intended medically useful properties of the combination depends. From the viewpoint of federal approval of the introduction of new drugs, the definition of "drug" includes at least the idea embodied in the words "in the form in which it is used or administered to the patient." Specifically, a new drug may be "new" in any several ways, e.g.: 1. A chemical or substance not previously used in humans for the treatment of disease (i.e., a "New Chemical Entity" or "New Molecular Entity"). 2. Two or more already approved drugs in a new combination not previously used for the treatment of disease. 3. An already approved drug to be employed for a new indication other than those for which it has been approved. 4. An already approved drug in a new dosage form, strength, or dose. 5. A chemical proposed for an in vitro diagnostic laboratory test, when its use will influence the diagnosis or treatment of disease in humans. The regulations regarding drug approval differ for "biologics", such as vaccines, which are reviewed by CBER (Center for Biologics Evaluation and Research). Chemically synthesized drugs and proteins manufactured using recombinant technology are handled at the FDA by its CDER branch (Center for Drug Evaluation and Research). Both the FDA regulations and documentation related to drug application approvals are readily available through its website (www.fda.gov). A physician may employ a drug in the treatment of a specific patient without seeking or obtaining permission for such use from the FDA, so long as the practitioner is not investigating the drug's potential efficacy in the treatment of the patient's specific disease. The intent of the Food & Drug Laws is, on the whole, to protect patients by regulating the introduction of new drugs into therapeutics, not to restrict medical practice by preventing a physician from using best professional knowledge and judgment when prescribing treatment adapted to the specific needs of an individual patient. However, if a physician wishes to test the efficacy of a drug for a new indication, then an IND is required before the clinical trial is initiated. II. Sources of Information on New Drugs The United States Pharmacopoeia (USP) describes standards for purity and assay of every drug approved by the FDA. This resource is important to manufacturers. The Physician's Desk Reference (PDR), text and electronic equivalents, duplicates drug labeling (as approved by the FDA). The label (the "package insert") describes a drug's pharmacological and pharmacokinetic properties, its indications, contraindications, side effects, toxicity, drug interactions, dose forms, and information (when available) regarding use in special populations such as children and pregnant women. This resource is NOT a critical guide to use of drugs in medicine. In addition to drug labels, the PDR contains other information, such as color photographs of drug products to assist in their identification. The FDA provides drug labels at Drugs@FDA and safety information at its Med- Watch portal. Physicians are provided letters from the FDA when new safety issues arise, and since 2008 this information is also rapidly updated on WebMD. Other internet resources used by patients such as Wikipedia have recently been documented to lag in updates on safety issues. ClinicalTrials.gov offers up-to-date information for locating federally and privately supported clinical trials for a wide range of diseases and conditions. ClinicalTrials.gov contains clinical studies sponsored by the National Institutes of Health (NIH), other federal agencies, and private industry, both in the U.S. and abroad. NIH, through its National Library of Medicine (NLM), has developed this site in collaboration with the FDA, as a result of the FDA Modernization Act of 1997. Numerous journals, such as the New England Journal of Medicine and JAMA, publish the results of clinical trials on drug therapy. These journals and resources such as The Medical Letter also provide critiques of the evidence of efficacy and toxicity of drugs, including newly approved ones. These resources or their equivalents are key to acquiring the evidence for rationale use of drugs in clinical practice. Advertising by manufacturers to both physicians and consumers is well documented to be a successful marketing tool for the sale of therapeutic agents. Direct-to- consumer advertising of prescription drugs, allowable in the U.S. since the early 1990's, is criticized by some experts because of its focus on newly approved drugs, which tend to be more expensive and for which there is more limited data on benefit and risk. Physicians are responsible for life-long dedication to use of evidence-based resources for decisions about drug use, rather than the advertising of manufacturers and their representatives. Note that some states, including Massachusetts and Vermont, have passed legislation to limit marketing practices designed to influence physicians' prescribing. (See NEJM 361:8, 2009 posted in Conflict of Interest session folder.) Another regulation to reduce undue influence of industry on physician's prescribing is the Physician Payment Sunshine Act, which requires industry as of 2013 to report to the Centers for Medicare & Medicaid Services all payments to physicians, including stock options, research grants, gifts, consulting fees, and travel to medical conferences.
pleomorphism
another way to define malignant tumor - tumor cells have no idea/resemblance to where they came from
tobacco epidemiology
- cigarette (and cigar and tobacco pipe) smoking causes 1 in 5 deaths/year in the US and 90% of lung cancers (including second hand smoke) - life expectance for smokers is >= 10 years less than for nonsmokers (lung cancer, CV disease, chronic resp disease) - quitting smoking before the age of 40 reduces the risk of dying from smoking-related disease by ~90% - smoking during pregnancy --> spont abortion, preterm births inc.; birth weight dec.
How do non-depolarizing blockers work?
- competitive inhibition of ACh binding to N receptor @ NMJ endplate - when ~70% bound, no ACh muscle contraction - results in *flaccid paralysis* of all skeletal muscle - indirectly antagonized by AChE inhibitors (because those inc. ACh in cleft to out-compete non-depol blocker) e.g. Tubocurarine
treatment for neonatal RDS
- maternal steroids before birth (GC trigger baby's surfactant) - artificial surfactant for infant - mechanical ventilation (high frequency) - oxygen supplementation
Why is bilirubin increased in the blood?
- Failure of hepatocytes to normally export bilirubin leads to it's increase in the blood. If there is mechanical blockage of the biliary tract, direct (soluble, conjugated) bilirubin is increased. If there is dysfunction of hepatocytes, non-conjugated bilirubin (indirect) is increased
Albuterol (terbutaline?) B2>B1 agonist
Agonist B2>B1 B2: bronchial smooth muscle relaxation for asthma long term use of B2 agonists can lead to risk of severe asthma exacerbation and death B2: relaxation of uterine smooth muscle to prevent contraction
dopamine Adrenergic Agonist
Agonist D1; B1>a1 B1: restoring BP after cardiogenic shock
Phenylephrine Adrenergic Agonist
Agonist a1 selective a1: nasal decongestant, restoring blood pressure (overdose of hypotensive agent, spinal damage or anesthesia) a1: mydriasis for opthamology a1: vasoconstriction to treat glaucoma
Integrin a4 Antagonist (Natalizumab)
- 95% humanize antibody targeting integrin alpha4 on lymphocytes - blocks lymphocyte interaction w/ adhesion molecules (MAdCAM-1) on vascular endo in inflamed regions of intestine - approved for MS and crohn's
common features of lysosomal storage disorders (LSDs)
- autosomal recessive transmission (except Hunters X linked recessive) "Hunter marks the spot with an X" - patient population consisting of infants and young children - storage of insoluble intermediates in the mononuclear phagosyte system, giving rise to *hepatosplenomegaly* - frequent CNS nivolvement with associated neuronal damage - cellular dysfunctions, caused not only by storage of undigested material but also by a cascade of secondary events triggered, for example, by macrophage activation and release of cytokines
progression of benign neoplasia-->metastatic
- benign - dysplastic (low grade--> high grade) - carcinoma in situ (vascular access) - invasive carcinoma - metastatic carcinoma
Mechanism for calcineurin inhibitors
- block T cell signaling for growth and differentiation by inhibiting enzymatic activity of calcineurin required for NFAT induction of T-cell IL-2 synthesis. (Net = no IL2 communication between T cells) Immunosuppressant Indicated for organ transplants E.g. Cyclosporine, Tacrolimus
mTOR inhibitors - mechanism
- block protein kinase (mTOR) activity required for cell cycle progression from G1-->S phase in T lymphocytes (Net = no replication of T lymphocytes) - immunosuppressant - indicated for organ transplants and contained in coronary stents E.g. Sirolimus (rapamycin)
Describe the changes in this hepatocyte
- Ballooning degeneration - In Ballooning degeneration, Hepatocytes show cellular swelling (also called "cloudy swelling" or "hydropic degeneration"). - This is a manifestation of sub-lethal cellular injury and results from dysfunction of ionic and fluid homeostasis in involved cell What is the pigment in the cytoplasm of this hepatocyte? - Bilirubin
toxicity and side effects of B blockers
- bronchoconstriction - bradycardia - exacerbation of angina, inc. risk of sudden death after abrupt withdrawal - fatigue - cold extremities - potentiation of E vasoconstriction - precipitation of CHF due to inhibition of adrenergic compensation (but also treat CHF) - predisposition to new onset diabetes
"Aspirin Intolerance"
- bronchospasm, rhinorrhea, and/or hives Induced by NSAIDs, *NOT* acetaminophen - more common in asthmatics - mediated by leukotrienes - cross sensitivity with other NSAIDs but not acetaminophen * I have this!! *
What is the main ultrastructural change associated with ballooning degeneration?
- Edema with swelling of the endoplasmic reticulum (ER) and detachment of ribosomes from the rough ER. - Note that mitochondria do not show the marked swelling and accumulation of dense bodies characteristic of irreversible injury in coagulation necrosis. - This type of reversible cell injury typically results from impairment of plasma membrane Na/K ATPase with a switch to anaerobic glycolysis and results in cellular dysfunction such as accumulation of bile in hepatocytes.
What has happened to the hepatocytes that were located about this central vein from an adjacent lobule?
- Lytic Necrosis What type of cells comprise the inflammatory infiltrate? - Activated T Cells - The inflammatory cells (predominantly lymphocytes and monocytes/macrophages) are present in the subendothelial space (space of Disse). - If a hepatocyte has undergone lytic necrosis and "disappeared", lymphocytes and macrophages may occupy the space it previously occupied. Lytic necrosis is typical of viral hepatitis and in this centrilobular area we see that hepatocytes, which normally extend up to the wall of the central venule have disappeared, i.e. have undergone lytic necrosis. Progressive injury occurs in the swollen hepatocytes, the nucleus undergoes karyolysis and the cell membrane ruptures. Within hours the necrotic cells are engulfed by macrophages.
What things does histamine mediate?
- allergic and inflammatory reactions - gastric acid secretion - neurotransmission in parts of the brain
Fish oil supplements/ omega-3-FAs
- contains DHA and EPA - 20-50% *decrease* in triglycerides - 15% decrease in non fatal MI and death in post-MI patients - effective adjunct for cardiac risk factor reduction - brands: Berkeley & Jensen (BJ's), CVS, GNC - dose: 1-3 g/day
prematurity
- gestational age of less than 37 weeks and weight less than 2500 grams - second most common cause of neonatal mortality (primary cause = congenital abnormalities) - ACOG estimates that 12% of all births in the US are pre-term deliveries
complications of oxygen therapy in neonatal RDS
- give too *high pressure* = bronchopulmonary dysplasia (BPD) "honeycombed lung" - also retrolental fibroplasia (retinopathy of prematurity) now we give low pressure, high frequency ventilation
Advantages of synthetic steroids
- greater selectivity (GC selective = dexamethasone, prednisone) - longer half-life and duration of action --> cortisol: duration 8-12 hours --> dexamethasone: duration 36-72 hours
Cytochrome P450 enzymes
- heme containing - embedded in membrane of SER (microsomes) - highest activity in *liver* - catalyze addition of molecular oxygen - about 17 human genes, most important for dugs = *Cyp 3A4 and 2D6*
health hazards of ionizing radiation (different sensitivities of different cells)
- high sensitivity: lymphoid and hematopoietic cells, germ cells, GI epithelium - moderate: skin, blood vessels, squamous epithelium, growing bone and cartilage - low: kidney, muscle brain, endocrine organs, adult bone and cartilage
mechanisms of alcohol toxicity + genetic variations
- metabolized mainly in liver, but also in brain and GI tract - alcohol metabolism *dec. NAD* and generates toxic *acetaldehyde* - NAD is required for FA oxidation --> end up w/ fat accumulation - acetaldehyde is a carcinogen (interferes w/ DNA replication and repair), contributes to incoordination, memory impairment, sleepiness, and can cause facial flushing, nausea, rapid HR genetic variations: - variants of the ADH and ALDH enzymes determine the acetaldehyde level (ADH forms it, ALDH breaks it down) - fast ADH and/or slow ALDH increases tolerance and protects against alcoholism
Gaucher Disease
- missing enzyme: glucocerbrosidase (cleaves glucose from ceramide) - accum material: *glucocerebrosides* tissues involved: spleen, bone, liver, and sometimes neurons in the CNS three clinical subtypes: - Type 1 = adult; spleen and skeletal involvement, reduced enzyme, slightly dec. longevity - Type 2 = infantile, cerebral, no enzyme, death at an early age - Type 3 - intermediate btwn 1 and 2 Clinical: - hepatomegaly (2-3x normal size) - splenomegaly (*15x normal size*) (spleno>hepato) - thrombocytopenia (excessive bruising and bleeding) - anemia - fatigue - low white cells; suscept to infections - "bone crisis" - insufficient blood circulation - bone thinning/fracture - *"Erlenmeyer Flask Deformity*"
A. Cell Wall
1. Outermost structure common to all bacteria, except Mycoplasma species which do not have a cell wall. 2. Multi-layered, located outside of the outer leaflet of the cytoplasmic membrane. 3. In Gram-negative bacteria, the cell wall is composed of inner layer of peptidoglycan and an outer membrane, and the periplasmic space in-between. 4. Polysaccharide and protein constituents of bacterial cell walls are often antigens used in lab identification. 5. The cell walls of Gram-negative bacteria contain porin proteins in the outer membrane which are involved in regulating the passage of small hydrophilic molecules into the cell, including essential nutrients and antimicrobial drugs.
2 drug transporters to know:
1. Pgp/MDR-1 (P-glycoprotein 1, multidrug resistance protein) - ABC transporter (ATPase, ABCB1 gene product) - amphipathic, cationic, and neutral - *verapamil* sensitive - actively transports stuff out; upregulated by anti-tumor drugs, causing resistance (drugs just pumped out); also present in normal cells to protect against OD (e.g. in intestinal mucosa, hepatocyte into bile, prox renal tubule into nephron lumen, brain @ choroid plexus and vascular endothelium) 2. OAT1 (organic anion transporter) - solute carrier family member (SLC22A6 gene product) - organic anionic substrates (for acid drugs) - *probenecid* sensitive
3 overall steps in acute inflammation
1. blood vessels dilate to inc. flow 2. microvascular changes allow proteins and cells to leave the blood vessel 3. emigration, accumulation, and activation of leukocytes
systemic effects of acute inflammation
1. fever 2. leukocytosis (colony stimulating factors promote inc. release of leukocytes from bone marrow) 3. tachycardia 4. tachypnea (inc. resp rate) 5. acute phase reactants (i.e. IL-6 causing hepatocytes to inc. synth of certain proteins)
absorption half-life for oral dose depends on:
1. formulation 2. gastric emptying time (needs to get to small intestine) 3. interaction w/ diet or other drugs in GI lumen bioavailability of an oral drug may be low due to: 1. mucosa barrier (blocks high MW, low lipophilicity; + carrier-mediated extrusion) 2. first-pass effect (lumenal, mucosal, and/or hepatic biotransformation during absorption process)
Using the data in the Table 1 (above), which of the following best describes the appropriate measure of association between acetaminophen and Reye's syndrome? Refer to the Stat-Ref tool if you need help with the analysis.
8/19 / 120/and 20 = .07 Odds Ratio = 0.07 Your 2x2 table for the association between acetaminophen and Reye's syndrome should look like this:
causes of pt variability in clearance by biotransformation
> dietary and drug interactions -- inhibition: substrate compeition, suicide inhibition (e.g. grapefruit juice) -- induction: promoters of enzyme expression (e.g. cigarette smoke) > disease -- cytokine-induced inhibition of hepatic enzyme synthesis -- reduction in hepatic blood flow (e.g. liver disease) > genetic polymorphisms in enzymes involved -- generally result in longer HL -- e.g. CYP450s, N-acetyltransferase, pseudocholinesterase (clears succinyl coA)
4. Describe the mechanisms and clinical implications of cell injury and necrosis a. Describe the morphology of reversible and irreversible cell injury and necrosis at the ultrastructural and light microscopic level b. Identify the causes of cell injury c. Distinguish the causes and morphologic appearance of cellular swelling and fatty change. d. Describe the morphology of coagulation necrosis, gangrenous necrosis, liquefactive necrosis, caseous necrosis, fat necrosis and fibrinoid necrosis and the disease associated with each.
APOPTOSIS This form of cell death differs in many ways from necrosis. It is closely controlled by a complex series of molecular switches and thus is referred to as programmed cell death. In contrast to necrosis, which involves the relatively chaotic and indiscriminate destruction of contiguous cells over an area or field of injury, apoptosis involves only scattered individual cells. In fact apoptosis is more often a physiologic process than a pathologic one, whereas necrosis is invariably a response to cell injury and thus pathologic by definition. Finally, the apoptotic process preserves the targeted cell membrane intact as the cell becomes fragmented so that no products are released and no inflammatory response is elicited. Apoptosis is the way that the body "quietly" rids itself of unwanted cells. Mechanisms of Apoptosis (Figure 2-14 in Robbins & Cotran). The execution of apoptosis is accomplished by the activation of a cascade of unique enzymes called caspases. These denature cytoplasmic proteins and fragment the cytoskeleton of both cytoplasm and nucleus. They activate DNAases that systematically digest the DNA into small fragments of uniform size. Ultimately the cell is converted into multiple membrane enclosed cytoplasmic fragments that contain nuclear debris. These apoptotic fragments are then rapidly engulfed by macrophages and removed from the scene. This final execution pathway may be initiated either by an extrinsic or an intrinsic mechanism. The extrinsic mechanism comes into play when ligands, which are often present on T lymphocytes, engage cell membrane receptors called death receptors. The best known are TNF Type 1 receptor and a related protein called FAS(CD95). When FAS, for example, is cross-linked by its ligand it provides a 14-9 binding site for an adaptor protein called FADD (Fas Activated Death Domain). This in turn binds pro-caspase 8 molecules and caspase 8 activation results and sets the caspase cascade in motion. The intrinsic or mitochondrial pathway is activated when anti-apoptotic proteins in the mitochondrial membrane (bcl-2 and bcl-x) are replaced by pro-apoptotic proteins (Bak & Bax). This results in increased membrane permeability and permits cytochrome c to be released into the cytoplasm where it binds to Apaf-1 and activates Caspase-9 and the caspase cascade. Causes of Apoptosis Adaptive or Physiologic Apoptosis Apoptosis is an essential mechanism for the following: Organogenesis, developmental involution and metamorphosis during embryogenesis. Hormone-dependent involution as occurs during the menstrual cycle and regression of the lactating breast after weaning. Cell deletion in proliferating cell populations such as the crypts of the colon. Death of neutrophils following conclusion of an inflammatory response and lymphocytes at the end of an immune response. Elimination of potentially harmful self-reactive lymphocytes. Apoptosis in Pathologic Conditions Viral diseases, particularly viral hepatitis. Cell death in some tumors Cell death in response to DNA injury induced by various stimuli including radiation and cytotoxic anti-cancer drugs. Cell death in response to accumulation of misfolded proteins in the endoplasmic reticulum [The unfolded protein response]. This mechanism is important in neurodegenerative diseases such as Alzheimer's and Parkinson's disease. Pathologic atrophy in parenchymal organs following duct obstruction such as occurs in salivary gland, pancreas and kidney. NECROPTOSIS Necroptosis is a recently described and still only partially understood form of programmed cell death. It is a hybrid of necrosis and apoptosis. It resembles necrosis morphologically and apoptosis mechanistically. It is triggered by ligation of TNFR1, by TNF and other molecules. Necroptosis is then driven by signaling by the RIP1 and RIP3 protein complexes, which reduces mitochondrial ATP generation, causes production of ROS, and permeabilizes lysosomal membranes, thereby causing cellular swelling and membrane damage as occurs in necrosis. Release of cellular contents evokes an inflammatory reaction as in necrosis. It is relevant in normal processes and several important pathological conditions including steatohepatitis and neurodegenerative conditions such as Parkinson's disease.
IV. Elimination of Drugs by Biotransformation or Excretion Unchanged
A. Total Clearance (ClT) 1. Total clearance is defined as the volume of plasma completely cleared of drug per unit time by all routes and mechanisms and provides a quantitative measure of drug elimination. 2. ClT is the sum of clearance values for each elimination route, e.g., Clrenal + Cl hepatic + Clalveolar + Clbiliary+........ 3. If intrinsic capacity of an organ to clear drug is high and exceeds plasma flow to that organ, then the clearance equals plasma flow and is altered by changes in plasma flow. 4. Variability in ClT among patients may require individualization of a dosage regimen. One factor may be body weight (BW); ClT generally increases with body weight ( ClT = BW 0.7 ). Other factors are described below and depend on the clearance route and mechanism. 5. The plasma elimination half-life of a drug is inversely proportional to total clearance and directly proportional to Vd. Therefore, for a given Vd, the higher the total clearance, the shorter the plasma elimination half-life.
Methadone maintenance
Advantages: - long acting (once/day) - oral (no needles) - reduces drug seeking (prevents abstinence, cross-tolerance to heroin) - regular contact with caregivers - agent of choice for detox Limitations: - highly regulated, requires special license - separate from PCP - limited availability - stable and unstable patients mixed - no privacy; social stigma - tied to clinic; employment difficult - can't "graduate" from program
fentanyl u/k
Agonist Agonist synthetic codeine; very high lipophilicity, mostly ionized short (less than 1 hour) rapid hepatic: CYP34A, 5, 60% first pass
Dobutamine B1 agonist
Agonist B1 selective B1: restoring BP after cardiogenic shock **some other complicated stuff
epinephrine Adrenergic Agonist
Agonist a1=a2; B1=B2 a1: extends local anesthetic action resusictation after cardiac arrest-->mainly a1 for vasoconstriction & B1 for HR & contractility a1: restoring blood pressure (overdose of hypotensive agent, spinal damage or anesthesia) a1: mydriasis for opthamology a1: vasoconstriction to treat glaucoma; a2: reduced secretion anaphylactic shock: a1, B1, B2 B2 can inhibit mast-cell release Low dose epi - decreases BP and increases HR High dose epi - increases BP and increases HR
This appendix was removed from another patient who developed generalized peritonitis. What complication has occurred?
Appendiceal rupture results in bacterial contamination of the peritoneum and can lead to sepsis and death. What physiologic processes are responsible for rupture? o Necrosisofthemuscularwalloftheappendixandproteolysisof extracellular matrix proteins by neutrophil and macrophage enzymes.
What components of the neutrophil are important for killing bacteria?
Azurophilic granules in the cytoplasm of neutrophils contain myeloperoxidase which can produce HOCl from hydrogen peroxide and chlorine to kill bacteria after they are phagocytosed.
Etanercept
Biological mediator ( interacts directly w/ signaling molecule) Soluble "decoy" TNF-alpha receptor, for autoimmune disease (psoriasis, RA) - traps TNF-alpha ligand so it can't bind to TNF-alpha receptor --> no TNF-alpha effect! Is like infliximab (anti TNF alpha antibody), but doesn't work against receptor-bound TNF-a (infliximab does)
Laboratory Medicine • Laboratory medicine is the integration of laboratory testing into the practice of medicine. • Laboratory medicine primarily involves testing done on "fluids" such as blood, urine, body fluids; and in a few instances "tissues" (microbiology, flow cytometry). • Anatomic pathology involves histopathologic evaluation of "tissues". • Most of the results resulted by the lab is performed by medical technicians, with a physician (clinical pathologist) interpreting a minority of cases. • 70% of medical decisions (ranging from diagnosis, monitoring of treatment, decision to admit or discharge a patient) are based on laboratory testing! • Sections: • Chemistry • Hematology • Microbiology • Blood bank • Point of care • Sendout / reference lab • Information technology (IT)
Chemistry Lab • Most chemistry tests involve measurement of a chemical or protein. • Common chemistry tests include blood gas, electrolytes, liver function, cardiac function, renal function, pancreas function, hormones, autoimmune disease, tumor markers, immunoglobulin, toxicology, and therapeutic drug monitoring tests. Hematology Lab • Common hematology tests include blood counts, leukocyte differential (peripheral smear and body fluids), urinalysis (especially the microscopic component), routine coagulation, special coagulation, hemolysis, hemoglobinopathy, and flow cytometry tests. Microbiology Lab • Microbiology testing involves identification of microorganisms (bacteria, mycobacteria, virus, fungi, parasites) through culture, stains, chemical reactions, molecular techniques, and proteomics. As well as other tests such as antibiotic susceptibility, viral load and genotype testing. lood Bank • The blood bank's primary responsibility is to provide blood products for transfusion (pRBC, PLT, FFP) and performing tests that ensure safe transfusion (type, screen, crossmatch). • Some blood banks perform blood replacement procedures (plasmapharesis and red cell exchange). • Also some blood banks have a blood donor center. Point of Care • Point of care (POC) involves tests that are performed by clinicians at the patient bedside which is not performed in the lab by a medical technologist (MT). • POC tests are easy to perform and easy to interpret. • POC tests include fingerstick glucose, Guaiac, urine pregnancy test, etc. • Some tests need to be made POC in some situations where a rapid test result is needed. • The lab still has to oversee the operational and compliance aspect of POC testing. Send Out / Reference Lab • There are many tests that are not performed in a hospital lab. • Send out tests are often technically difficult to perform, rarely performed, or costly. • Smaller hospital labs will have to rely more on reference labs. Laboratory Information System • Laboratory information system (LIS) is a software that laboratories use to minimize human errors and maximize efficiency. • Direct orders from electronic medical record (EMR) into the lab. • Notify phlebotomist what type of blood tube and how many blood tubes are needed for a test. • Partially automate receipt and accessioning of a specimen. • Direct interfacing with a laboratory instrument for test order and result. • Potentially catch mistaken patient identity based on previous results (delta check). • Report results into the EMR. Steps in Laboratory Analysis • Pre-analytic phase: The step before the specimen is either received in the lab or being tested. • Analytic phase: The step when the specimen is being tested and a result is generated. • Post-analytic phase: The step when the generated result is seen by the clinician who then uses the result in making a decision. Pre-Analytic Variables for Laboratory Testing • Proper patient identification and specimen labelling. • Time of day specimen is collected (i.e. fasting state for glucose and lipid testing, peak and trough sampling for therapeutic drug monitoring). • Right tube for the given test. Color Additive What Happens Used For Red (glass) None After clot has formed, serum is collected Some chemistry tests, some toxicology Gold Clot activator, serum separator gel After clot has formed, gel separate serum from clot Most common chemistry tube Lavender or Pink EDTA EDTA chelates calcium, because calcium is needed in coagulation, it acts as an anticoagulant and allows testing to be done on whole blood Lavender tops are used for hematology and molecular tests. Pink tops are used for blood bank. Green Heparin Heparin inhibits thrombin (through antithrombin III) and acts as an anticoagulant, allowing testing to be done on whole blood Some chemistry tests, cytogenetics Blue Citrate Citrate chelates calcium and acts as an anticoagulant, it allows the extraction of plasma Coagulation tests Gray Glycolysis inhibitor Inhibits glycolysis Forensics and some glucose studies Pre-Analytic Variables for Laboratory Testing • Quality of the specimen • Minimizing hemolysis. • Adequate mixing of anticoagulated blood tests (lavender, blue, pink, green top tubes). • Sometimes more is better, especially for microbiology tests (i.e. submitting tissue or an aspirate rather than a swab). • Not collecting blood downstream of an infusion site. • Collecting blood for coagulation testing that is free of line anticoagulants (i.e. flushing lines kept open with heparin). • Minimizing specimen transport time or time between draw and receipt in lab. Analytic Variables for Laboratory Testing • Manual vs automated testing. • Quantitative vs qualitative test results. • Most tests are quantitative and are resulted by MT without review by pathologist. • Some qualitative and interpretational tests are reviewed by a pathologist (i.e. problematic peripheral smears or body fluid cytospins, bone marrow aspirate smears, flow cytometry, SPEP/UPEP with or without immunofixation, ANA, abnormal T&S, transfusion reactions, etc). • Interference • For tests dependent on optical transmittance, factors that change the color or clarity of serum/plasma such as hemolysis, icterus, and lipemia may interfere with the assay. • For immunoassays, rarely false positive results can be seen in patients who have heterophile antibodies (human anti-animal antibodies that react with antibodies used in laboratory testing that are generated in animals). • Difficulty of a case (some tests may be difficult to interpret either due to equivocal findings, rarity of a case, multiple concurrent disease processes, etc) Post-Analytic Variables for Laboratory Testing • The time it takes for the generated lab result to transfer from the LIS to the EMR. • The time it takes for the ordering clinician to see the result in the EMR. Some lab values are deemed to be life-threatening and are designated as a critical alert value (CAV). • Laboratory accreditation and regulatory agencies (i.e. CAP, Joint Commission) stipulate that CAVs must be relayed from the lab to the ordering clinician within 30 minutes of the lab result. • The idea behind CAV is to minimize the post-analytic phase and possibly prevent death, especially for outpatients. • In our hospital, CAVs include a K+ <2.8 or >5.8, hemoglobin <7.0, a positive blood culture, and many others. Turnaround Time • The time it takes from specimen draw or specimen receipt in the lab to the generation of the lab result is the turnaround time (TAT). • TAT can vary based on specimen transport time, how often a test is run (some tests are 24/7/365, others are batched), the actual running of a test, etc. • Some tests require a fast TAT such as blood gas, whereas others may not such as molecular testing for genetic counselling. Quality Control • Quality control (QC) is a standard step of running designated QC reagents to make sure that a test (whether automated, semi-automated, or manual) is generating correct or reasonably accurate results. • Even for an automated test, just because a test is run on a machine does not mean it is always right. Instruments are prone to "drifting" and have to be kept in check with QC. • QC optimizes the analytic phase of lab testing. • Manufacturers sell QC reagents which have a known range for an acceptable result. • Some tests have three ranges (low, normal, and high i.e. WBC) or two ranges (normal and high i.e. PTT) of QC reagents. • Qualitative tests have two QC reagents (positive and negative i.e. malaria antigen test). • Example of performing QC before a run: • The range for normal platelet (PLT) count QC reagent is between 250 - 350K. • If your QC reagent yields a result of 300K, your QC is acceptable and you can your run patients. • If you QC reagent yields a result of 200K, your QC has failed. • When QC has failed, you can not run any patient samples until troubleshooting has occurred and the repeat QC has passed. • Troubleshooting can involve examination of reagents, examining MT performance (consulting procedure manual), recalibrating the instrument, etc. • For most tests, QC is run at the beginning of every shift (3 times a day). • For low volume or batched tests, QC is run before each run. QC can also be evaluated as an overall trend (in addition to daily operations) to make sure there is no systemic bias or drift in results. • Levey-Jennings plot is a graphical representation of results from QC reagents over time. • Westgard rules are rules recommending re-evaluation of a test if QC results over time show too much departure from the mean, systemic bias, or too much variation. • Quality assurance (QA) is the systematic approach overseen by the pathologist/medical director and laboratory supervisor to improve laboratory function including pre- analytic, analytic, and post-analytic variables. • QA can be achieved globally as well as monitoring performance in proficiency surveys and engaging in QA projects. • Many QA projects aim for improving TAT but other things can be monitored such as proper labelling of specimens, minimizing corrected reports, minimizing contamination rates, expeditious reporting of CAV, etc. • When a test/instrument is being replaced or a new test/ instrument is brought to a hospital, many things have to be considered. • Automation: Ideally a more automated test allows for greater ease, improved efficiency, and minimization of human errors. • Accuracy: Measures how close a method is in providing a test value that is close to the "true" value. • Precision: Measures the reproducibility of the assay such that if a test is performed multiple times for a given sample, the results should be similar. • Validation: Whenever bringing on a new test/instrument, validation has to be performed comparing the new with either the previous test/instrument or a "gold standard". Reference range: A reference range has to be created for every test using your patient demographics. The reference range includes values within 2 standard deviations of the mean (95% of normal or non-diseased patients). Rarely published reference ranges can be used for a test. Reference ranges can differ based on age, gender, time of year, time of day, etc. • Linearity: The reportable range for a given test that a lab feels comfortable in reporting. The manufacturer will recommend a reportable range. However the lab should also have a sense of kind of range reported is accurate. Hence sometimes lab results may be reported as "greater than __" or "less than __". • CLIA 88 or the Clinical Laboratories Improvement Act is a law passed in 1988 which mandates medical director oversight of clinical labs, use of FDA-approved reagents and instruments, and periodic inspection of labs by an accrediting agency (CAP, Joint Commission, Food and Drug Administration). • In an ideal world, all results generated by the lab would reflect what is happening in the patient. • However that is usually not the case and test results have to be compiled with history, physical, and imaging to make the correct diagnosis. • Just like pathologists have to use test performance statistics in deciding what is the best methodology, reagent, or instrument to bring to their lab; clinicians also have to use these same statistics in deciding which tests to perform. • Statistics is used by pathologists in deciding on validation results for a new test/instrument and by clinicians in deciding what test to order. • The test in question is compared to a "gold standard". In real life, there are very few gold standard tests and the gold standard might actually entail a compilation that includes history, physical, imaging studies, lab tests, and even looking at these factors in a retrospective manner. • Prevalence = Disease ÷ (Disease + No Disease) • Sensitivity is how good an abnormal test result detects a disease process. • Sensitivity = TP ÷ (TP + FN) • Specificity is how good a normal test result detects a normal process. • Specificity = TN ÷ (TN + FP) • Positive Predictive Value (PPV) is the probability that a positive test result predicts the patient has disease. • PPV=TP÷(TP+FP) • Negative Predictive Value (NPV) is the probability that a negative test result predicts that the patient does not have disease. • NPV = TN ÷ (TN + FN) • In the ideal world a test would have close to 100% sensitivity, specificity, PPV, and NPV. • In the real world, this is not the case. • Usually improvements in sensitivity causes specificity to suffer and vice versa. • A receiver operator characteristic (ROC) curve plots the true positive rate (sensitivity) vs the false positive rate (1 - specificity) and is a graphical representation of finding the best cutoff (where sensitivity and specificity are maximized) in discriminating disease from no disease. Integration of Laboratory Results in Medicine • Screening tests should have good sensitivity, whereas specificity isn't as important. • Confirmatory tests should have good specificity, whereas sensitivity isn't as important. • Ideally the appropriate number of tests are ordered in order to make the right diagnosis. • The laboratory is a very important component in medicine. • Consult the clinical pathologist if you have questions about a test, test algorithm strategies, or even bouncing off ideas on how to manage or treat a patient. • Although frequently right, the laboratory isn't always right. If there is a lab result that is incongruous with the clinical picture, contact the pathologist.
COX1
Cyclooxygenase enzyme that makes prostaglandins, thromboxanes, prostacyclins - provides us with stuff that's *good for us!* - *constitutively expressed* - *gastric cytoprotection* -- why COX1 blockers = not as good - vascular homeostasis - platelet aggregation - kidney function
Describe the major classes of adrenergic receptors and their effects on major organ systems.
Endogenous Adrenal Mediator Epinephrine Postganglionic Adrenergic Neurotransmitter Norepinephrine Endogenous D1 Agonist/Neurotransmitter Dopamine α1 Selective Agonist Phenylephrine α2 Selective Agonist Clonidine β Selective Agonist Isoproterenol "β1 Selective" Agonist Dobutamine β2 Selective Agonist Albuterol Indirect Agonist (Transmitter Releaser/False Transmitter) Tyramine Indirect Agonist/Central Stimulant (Transporter Inhibitor/Releaser) Cocaine d-Amphetamine Methylphenidate α Antagonist Phentolamine α1 Antagonist Prazosin β Antagonist Propranolol β1 Antagonist Metoprolol β + α1 Antagonist Carvedilol
Acute vs chronic glucocorticoid replacement therapy
For adrenocortical insufficiency Acute: - high doses of hydrocortisone Chronic: - e.g. Addison's disease (autoimmune e.g. Rxn against 21-a-hydroxylase-->insufficient steroid produced by adrenal ctx) - physiologic doses of hydrocortisone and fludrocortisone (mineralo)
DrugAction,DoseEffect,rugSeelctivity Receptor Classes • Physiological ReceptorsPhysiological Receptors - Ligand-gatedionchannels - G-ProteinCoupledReceptors(GPCRs) - GrowthFactor/CytokineReceptors - IntracellularHormoneReceptors • Enzymes BLOCK: Penicillin (-lactam antibiotic) - transpeptidase Zidovudine - reverse transcriptase Physostigmine - acetylcholinesterase Disulfiram - aldehyde dehydrogenase • Transporters - Cocaine: Inhibits uptake of catecholamines and serotonin SERT NET DAT - Fluoxetine: Inhibits serotonin uptake SERT • Voltage-gated Ion Channels - Local anesthetics: inhibit voltage gated Na channels :Lidocaine, benzocaine, cocaine Cachannelblockers:inhibitvoltagegatedCachannels Nifedipine, Diltiazem • Structural Proteins vinblastine: Interfere with microtubule polymerization • Nucleic Acid - e.g. Cyclophosphamide: DNA alkylating agent used for immunosuppression and cancer chemotherapy • Biological Mediators (interact directly with signaling molecules) - Etanercept (soluble "decoy" TNF-α receptor, autoimmune diseases (psoriasis, rheumatoid arthritis)) Molecular structures which are receptors for endogenous substances Have a physiological signaling role Regulate physiological functions Can transduce signal from extracellular to intracellular space or from intracellular space to nucleus Agonists: bind receptor and generate effect, electrical or biochemical change ("2nd messenger") Ligands include neurotransmitters, hormones, and growth factors
GABA a receptor GPCR: CRF Adenosine CAnnabinoid Adrenergic Opioid • Therapeutic Effect (beneficial effect resulting from a drug treatment) • Non-therapeutic Effects • Placebo Effect Dose-intensity (graded) - How much effect? • X-axisdrug concentration or dose • Y-axis% effect • Dose-frequency (quantal) - How many affected? • X-axisdrug concentration or dose • Y-axis% of subjects responding Dose Dose-Intensity Curves (graded) KD is the drug concentration at which 50% of receptors are occupied 1:1 [Effect] / [Effectmax] [Drug]/ EC50 +[Drug] Why semilogarithmic plots? • Because linear plots are more difficult to be handled: close to the zero the effect changes rapidly • Semilogarithmic curves have a large middle portion close to the EC50, which is linear and easier to work with (easier to make accurate determinations) Emax vs EC50 Potency = EC50 = [ ] of a drug able to give the 50% of its maximal effect Efficacy = Emax = maximum effect of a drug achievable at high dose Potency ≈ how well the drug binds the receptor Efficacy ≈ how well the drug produces the effect Selectivity can be due: to a difference in binding affinity (Kd) of that drug for different receptors to the number of spare receptors ( spare receptors EC50) differences in drug access to receptors on different tissues Full agonist: a drug that binds to a receptor and produces a maximal biologic response Partial agonist: a drug that has efficacy greater than zero but less than that of a full agonist Neutral antagonist: a drug that does not induce a biological response and reduces/blocks the response induced by the agonist Inverse agonist: a drug that induces a pharmacological response opposite to that of the agonist Chemical Antagonism (see Etanercept) Occurs when the antagonist interacts with the agonist to render the agonist inactive. Pharmacokinetic Antagonism Occurs when the antagonist accelerates the metabolism or the elimination of the agonist. Physiological Antagonism Occurs when the antagonist activates a different mechanisms that opposes the effects of the agonist Pharmacological Antagonism (occurs at a receptor level) 1. Reversible competitive 2. Noncompetitive 3. Irreversible competitive 1. Reversible competitive the antagonist binds the same receptor site bound by the agonist the two drugs compete for the same site both agonist and antagonist bindings are reversible right-shift of the dose-response curve (higher ED50) unchanged Efficacy competitive antagonism is surmountable, meaning that it is always possible to "overcome" inhibition by increasing the concentration of agonist, in order to achieve the same magnitude of effect as before 2. Noncompetitive the antagonist binds the receptor to a different site than the site bound by the agonist (insurmountable) the antagonist does not interfere with the binding of the agonist decreased Efficacy (lower Emax) unchanged Potency noncompetitive antagonism is insurmountable. One cannot necessarily restore the original response of the agonist by increasing the concentration of the agonist 3. Irreversible competitive resembles noncompetitive typically insurmountable decreased Efficacy (lower Emax) unchanged Potency usually results from covalent binding of antagonist to receptor effect of drug may long outlast its presence in the body and is determined by the time required for the body to reconstitute the drug's target Spare Receptors Agonist concentration=Kd 50% receptor occupancy A certain response Agonist concentration<Kd ~20% receptor occupancy The same response as in 1 Receptor excess Limiting step downstream to binding An agonist may produce a maximum response even though the agonist concentration is not high enough to fully occupy all of the available receptors Spare receptors increase the apparent potency of agonists, because the response reaches 50% of Emax at a concentration at which less than 50% of receptors are occupied by agonist (i.e. EC50 < Kd). Receptor is assumed to exist in two conformations: inactive (Ri) and active (Ra) Nature of the drug (agonist, antagonist, etc) arises from differences in affinity constant for the active state and the inactive states Drugs act stabilizing either Ri or Ra conformation Inverse agonist: a drug that induces a pharmacological response opposite to that of the agonist. If there is an elevated basal response in the absence of ligand (agonist- independent constitutive activity), then activity will be inhibited and A will then be an inverse agonist (Negative Efficacy) Summation (the joint effect of the two drugs is the algebraic sum of their individual effects) • Synergism (the joint effect of the two drugs is greater than the algebraic sum of their individual effects) • Potentiation (an inert drug potentiates the effect of another drug. Ex.: Benzodiazepines and GABA) - Increasing potency - Increasing efficacy Allosteric modulators: bind receptor at site other than that of endogenous ligand and potentiate or inhibit the effect of the ligand Diazepam (a benzodiazepine) potentiates ( potency) the effects of GABA on GABAA receptor function (current, chloride channel) Flumazenil acts as a competitive inhibitor of an allosteric modulator competing with Diazepam (not GABA!) • Tolerance - Cross-tolerance (tolerance can develop for other drugs with the same mechanism of action e.g. same receptor) - Tachyphylaxis (the effect of the drug declines very rapidly. Timescale of minutes) - Desensitization (mechanism for decreased effect (including tachyphylaxis)) • Sensitization (cocaine, locomotor sensitization) To clarify the proper dose of a given drug that produces the desired therapeutic effect while limiting harmful side effects • To determine therapeutic and hazardous drug dosages Dose-Frequency curves (quantal) • Quantal dose-response curves are all or nothing: the effect is scored in a binary (present/absent) fashion • IntegratedGaussianbell • A continuous effect may be converted to quantal by defining a threshold effect intensity criterion (effect ≥ threshold present) • How many (what percentage of) subjects respond at a particular dose? Shallower slope indicates greater variability • Different slopes imply different sources of variability, suggesting difference in route or mechanism of action Nature of variation - Pharmacokinetic (Clearance, Distribution) - Pharmacodynamic (Receptor number, type, location, endogenous mediators) • Sources of variation - Genetic heterogeneity (different receptors, different receptor distribution, different enzymes of biotransformation, etc.) - Disease (impact of renal or hepatic disease on the effect of drugs) - Physiological state - Drug interactions (older people) Side effects - Pharmacologic - Pharmacokinetic - Allergic (hypersensitivity) - Idiosyncratic • Toxiceffects - Overdose Represents an important aspect of the post marketing surveillance of drugs (pharmacovigilance) • Unintended or unexpected • Noxious • Licituse • Severe • Ascribable to drug - Known effect of drug or class - No other cause - Timing consistent - Blood levels consistent - Reproducible ED50 = Dose producing an effect in the 50% of the subjects LD50 = Dose producing death in the 50% of the subjects Therapeutic Index as a measure of safety: LD50/ED50 Compare T1>T2 = Drug 1 sis safer than Drug 2 Importance of population variability: Same Therapeutic Index, different risk Standardized safety margin: LD1-ED99/ED99 Sources of placebo "response" A therapeutic "response" to an inactive drug or treatment • Spontaneous improvement ("most things get better on their own") • Subsiding toxic effect of previous treatment • Bias (often unintentional) • Power of suggestion? (controversial topic) • Use of placebo and ethical concerns Placebo controlled studies: • The "gold standard" of pharmaceutical research is the double-blind placebo-controlled study, in which some patients receive placebos and some receive active drug, but neither the patient nor the researcher knows which is which until the end of the study. • The double-blind design also controls against experimenter bias in selection of subjects or analysis of data • A valid placebo control must be indistinguishable from active drug in all respects (e.g. size, taste, color). Albuteral, antidepressants, Rofecoxib,Open vs. hidden drug administration
Ranitidine
H2 antagonist (H2 works via cAMP; affects GI) Not for this class; just to start knowing
G. Host Immune Response 1. Innate and adaptive immune responses play a critical role in preventing, controlling, and eliminating infection, and sometimes in the pathogenic process. There is a constant, complex, and always evolving "dance" between the host immune response and infectious organisms at every step in the disease process. 2. In most cases, bacterial infections are resolved with clearance of the organism and development of immunity to the infecting strain and closely related strains. However, this is not always the case. Understanding the immune response to specific bacterial pathogens is crucial for devising effective strategies to prevent these infections; strategies that work for some may not work for others.
H. Progression or resolution of disease 1. There are many different outcomes of infection depending on a complex array of bacterial and host factors, including complete resolution (clearance of organism with no significant damage to the host), chronic infection (for weeks, months, years, lifetime) with or without symptoms, clearance of organism with sequelae ("hit-and- run", e.g. autoimmune disease). Study Questions 1. What is the difference between the LD50 and the ID50? Why are these measures of virulence measured in terms of 50% of an experimental population? 2. What does the term "virulence" mean? If I tell you that Shigella species are more virulent than Salmonella species, and that Bob ate 1 cup of salad contaminated with Salmonella and Barb ate 1 cup of salad contaminated with Shigella, who would you predict will get sick or get sick first? Why? 3. If Barb didn't get sick from eating the Salmonella-contaminated salad, what 2 basic requirements for the production of infectious disease were not likely met? 4. What host factors can increase the likelihood that exposure to an infectious agent will result in disease? 5. People with defective or deficient humoral immune responses are more susceptible to infections with ____________________. 41-8 6. List at least 4 ways in which one can be, or become, immunocompromised. 7. For an immunocompetent person, the most likely outcome of an exposure to an infectious agent is ___________________________. 8. Describe the major differences between acute and chronic infections. 9. What are the common mechanisms by which bacteria cause disease and how do they differ? 10. What are the 4 typical stages of an infectious disease? 11. What are the clinical signs of the prodrome and why are they the same regardless of the infectious agent? 12. What are 3 bacterial structures that mediate adherence and why are they considered virulence factors? What types of surfaces do bacteria adhere to? 13. List several bacterial virulence factors and explain how they enhance the ability of bacteria to produce disease. 14. What is the difference between pyogenic and granulomatous inflammation? What is pus composed of? 41-9 15. Why is the ability of a bacterium to invade and survive inside a cell considered a virulence factor? 16. What is the definition of an exotoxin? Of an endotoxin? Which one would you guess might be listed on the Homeland Security's list of potential biowarfare agents? Why? 17. And while we are on the topic of the Homeland Security's list of potential biowarfare agents... which two microorganisms that are on this list were recently in the news because of lapses in safety protocols at the Centers for Disease Control (CDC)? Hint: one is a bacterium and one is a virus. 18. Do endotoxins or exotoxins make the best vaccines? Do they have to be in their active form to elicit an immune response? Do they need to be associated with the bacterial cell that produces them to be effective? 19. Do all exotoxins have the same mode of action? 20. What is the main endotoxin found in Gram-negative cells and what are the 2 most serious clinical syndromes it causes? How does endotoxin produce these syndromes? 21. What endotoxin-like components are found in some Gram-positive cells? In all Gram- positive cells? 23. Where are the genes for exotoxins and endotoxins usually located? What are the consequences of this? 24. What is a toxoid? Why are toxoids used in vaccines to protect against the effects of exotoxins, but not endotoxins? 25. Describe 3 examples of immunopathogenesis. 26. How can some bacteria be pathogenic even when they are no longer viable? 41-10
Describe factors in oral dosage forms that may affect drug absorption rate Learning Objectives: •
I. Introduction BIOPHARMACEUTICS & DRUG DELIVERY SYSTEMS Karen M. Harnett, Ph.D. [email protected] Describe factors in oral dosage forms that may affect drug absorption rate Learning Objectives: • • Describe transdermal and pulmonary drug delivery devices and their therapeutic advantages (Note: Specific examples of marketed drug formulations are provided below for illustrative purposes only.) A. The choice of a therapeutic agent entails determining the appropriate drug class for a specific indication and then the particular drug within that class. In addition, there may be multiple formulations of a particular drug, so that a decision must also be made as to the most appropriate formulation for a particular therapeutic indication in a specific patient. The objectives of modified formulations of a drug may be to improve its bioavailability, increase its duration of action, or increase its selectivity by localized administration at a target site. B. FDA approval of a drug is for a specific formulation and dose. New formulations must be tested in clinical studies and approved by the FDA prior to marketing. II. Factors Affecting Drug Absorption from the GI Tract The absorption rate of a drug from an oral formulation may be affected by the disintegration of the formulation, the dissolution of the drug into the aqueous fluids of the gastrointestinal lumen, and then the drug's diffusion rate through the gastrointestinal mucosa. The primary determinant of the absorption rate is likely to be the slowest of the three processes, the 'rate-limiting' step. Drugs with low aqueous solubility have drug dissolution as the slowest step that limits drug bioavailability. Drugs with high aqueous solubility have fast dissolution rates but have movement of drug across the membrane as the rate-limiting step in bioavailability. A. Rate of disintegration of solid dosage forms within the gut. Tablet disintegration time is not necessarily correlated with either dissolution rate of the drug or the amount of drug absorbed systematically. Enteric-coated products are designed not to disintegrate in the acid conditions of the gastric lumen and are used to improve bioavailability of drugs that undergo degradation in acidic solution. B. Rate of dissolution of drug molecules from solid particles in the gut. Aqueous solubility is enhanced by a charge on the molecule, and so solid formulations may be prepared from the salt form rather than uncharged drug (in the case of acidic or basic drug moieties), in order to enhance dissolution rates. C. Rate of diffusion of drug molecules through gastrointestinal epithelial cell membranes. This phenomenon is dependent on the drug's lipophilicity. III. Factors Affecting Dissolution Rate in the GI Tract A. Surface area of the drug particles or crystals; the greater the surface area relative to mass, the more rapid the dissolution. Particle size is important for drugs with low aqueous solubility. B. Drug solubility in the area immediately surrounding solid particles of drug (e.g., the solubility of a weak acid in the stomach is increased by administering it as a highly water-soluble salt or by combining it with a basic substance, such as NaHCO3 in the case of 'buffered' aspirin). C. Crystallization state of the drug. Some drugs exist in both crystalline forms and non-crystalline forms. Crystalline forms are more rigid, stable structures with low free energy that dissolve more slowly than non-crystalline forms. The crystalline form of drug with the highest aqueous solubility will have the highest absorption rate. D. Excipients (inactive ingredients) and manufacturing processes 1. Adsorptive fillers (e.g., CaSO4) may accelerate tablet disintegration 2. 'Lubricants' (e.g. salts of stearic or lauryl acids) used to facilitate tablet production may alter dissolution 3. Starchcontent 4. Compression pressures used in tablet production 5. Specific coatings such as "enteric coating" to prevent dissolution in gastric contents or controlled-released dosage forms (see next section) IV. Methods for Preparing Oral Controlled-Release Dosage Forms A. Control of Dissolution Rates, by coating drug particles with polymers that dissolve under different conditions, or over time, depending on thickness. B. Ion Exchange Methods, in which water-soluble, ionizable drugs are complexed with appropriate cationic or anionic resins and prepared as tablets or capsules. After ingestion, ions in the GI contents displace drug molecules into the luminal fluid. C. Repeat Action, in which a drug particle is completely released once its coating has been breached by physical factors such as pH, gut action, etc.; however, the timing of particle release is not precise. D. Osmotic Pump: the drug-containing core is surrounded by a semi-permeable membrane that allows water to enter the core; the resulting drug solution is then "pumped out" through a rate-limiting single hole cut into the membrane with a laser. [Example: Procardia XL® brand of the calcium channel blocker nifedipine, to permit once-a-day dosing]
Mechanism of NSAID analgesic effect
Inhibit peripheral PGE2 synthesis Possible inhibition of constitutively expressed COX2 in the dorsal horn of the spinal cord Relieve mild to moderate pain Limited maximal effect - higher EC50 and lower Emax than opioids
How do nsaids inc. bleeding time?
Inhibit thromboxane synthesis - prolong bleeding time by inhibiting normal formation of platelet plug and coagulation * Aspirin irreversibly inactivates cox 1 in platelets --> a single analgesic dose of aspirin doubles bleeding time for the life of the platelet (4-7 days) (why dad couldn't take NSAID before surgery) * Acetaminophen does NOT affect platelet function (useful drug)
loading dose
LD = Cp_ss x Vd or Cpavg x Vd
specify two of the major glycogenoses: von Gierke's disease and Pompe's disease
Lysosomal storage diseases - Glycogenoses deficiency of any of the enzymes involved in glycogen catabolism. Three main categories are: 1) Hepatic form - the liver is a key organ in glycogen metabolism. Deficiency of glu-6 phosphatase leads to Von Gierke's disease, glycogen accumulates in all tissues but hepatomegaly and hypoglycemia dominate the clinical picture. Mortality approximately 50%. 2) Myopathic form - glycogen is an important source of energy in muscle. If there is an enzyme deficiency in glycolysis it leads to glycogen accumulation and muscle weakness. McArdle's disease is due to a deficiency of muscle phosphorylase which results in painful cramps with exercise and failure to induce elevated lactate levels in blood. Normal longevity. 3) Pompe's disease - a lysosomal enzyme deficiency of acid maltase, which leads to widespread deposition of glycogen in all organs but cardiomegaly, is most prominent. Cardiorespiratory failure ensues in two years. A milder adult form affects skeletal muscle only and is associated with chronic myopathy.
Introduction to Neoplasia Adaptive response, hyperplasia
Metaplasia - a reversible change from one adult cell type to another adult cell type: Adaptive Dysplasia- - Loss of normal orientation of one cell to another in a particular tissue - Preneoplastic - Associated with cellular "anaplasia" - Metaplasia, Gastroesophageal junction Barrett Esophagus Differentiation - the extent to which neoplastic cells resemble the parent cell of origin • "Well" differentiated - close resemblance to parent cell • "Poorly" differentiated - more primitive • "Moderately" - between well and poorly differentiated • For glandular tissues - ability to form glands • For squamous epithelium - ability to form keratin Epithelia Squamous - skin, oral mucosa cervix Glandular - ducts, GI tract, endocrine glands Transitional - bladder, ureters • Mesenchymal tissues Connective tissues - fibrous, muscle, bone, cartilage, blood vessels • Specialized tissues Gonads - germ cells Brain • Benign neoplasms • Cells resemble normal cells • Well circumscribed (encapsulated) • Localized - do not spread to other sites • Amenable to surgical excision • Mesenchymal - connective tissues - often designated by the suffix "oma" • Benign tumor of fibrous tissue - fibroma • Benign tumor of smooth muscle - leiomyoma • Benign tumor of adipose tissue - lipoma • Benign tumor of cartilage - chondroma • Benign tumor of endothelium - endothelioma Squamous - Papilloma • Glandular - Adenoma Benign • Dysplastic - Low grade - High grade • Carcinoma in situ • Invasive carcinoma • Metastatic carcinoma Could still be problematic - Due to location - Due to functional status - Due to complications - Due to "syndromic complexes" • Multiple endocrine neoplasia Adrenal gland tumor Familial Adenomatous Polyposis (FAP) MatureTeratoma - Arises from germ cells, and can give rise to different types of tissue. • Mixed tumor- may have neoplastic components of epithelial and mesenchymal (stromal) elements Carcinoma in situ of breast: Intact basement membranes, Invasive Adenocarcinoma, Invasive Squamous cell carcinoma, Malignant tumors, invasive, Pleomorphism + Mercedes benz Malignant tumors • Lack of differentiation of cells • Cellular pleomorphism • Nuclear pleomorphism • Increase in Nuclear cytoplasm ratio • Prominent nucleoli • Aneuploidy (abnormal DNA content) • Hyperchromasia of nuclei • Abnormal mitosis • Tumor giant cells • Anaplasia Lymphovascular Invasion: -how a tumor spreads in the body Tumor cells in a lymphatic space Tumor cells in a lymph node CANCEROUS: Lymphoma • Melanoma • Mesothelioma • Hepatoma • Epithelial cells - carcinomas (i) Glandular - Adenocarcinomas (ii) Squamous - Squamous cell carcinomas (iii) Urothelium - Urothelial carcinomas • Mesenchymal cells - sarcomas Fibrosarcoma Leiomyosarcoma Chondrosarcoma Osteosarcoma • Organ specific - Hepatocellular carcinoma (hepatoma) - Renal cell carcinoma - Papillary carcinoma of the thyroid • Germ cell tumors - Seminoma - Embryonalcellcarcinoma - Choriocarcinoma • Brain - Astrocytomas - Meningioma Grade: • Well differentiated - grade 1 • Moderately differentiated - grade 2 • Poorly differentiated - grade 3 Stage of tumor: • TNM criteria - Tumor - Nodes (Lymph nodes) - Metastasis Staging is more prognositc
Buprenorphine
Miu (u) partial agonist Need to be off of morphine (and methadone) for 8-10 days before you can switch to it (get down to buprenorphine's Emax) Tx combined w/ naloxone --> naloxone won't be absorbed well sublingually (pretty much no bioavailability), so if you take the combined drug right, it won't have an effect; however, if you try to inject buprenorphine for a high, naloxone will block it
Use of diphenhydramine for Type 1 hypersensitivity reaction?
NO! Not drugs of choice for asthma or T1 hypersensitivity b/c *not bronchodilators!!* Tx = epinephrine - physiological antagonist (dif rec) to open up airways
Opioid Receptor Antagonist (drugs)
Naloxone Naltrexone
Succinylocholine
Nicotinic Agonist; muscle relaxant depolarizing blocker, noncompetitive; binds to nicotinic receptor and causes receptor desensitization & voltage gated channel inactivation; rapid onset and duration DO NOT TREAT WITH AChE INHIBITORS! This will prolong action; succinylcholine is hydrolyzed by cholinesterase patients w/ genetic disorder causing excess Ca2+ release in skeletal muscle-->malignant hyperthermia due to excessive muscle contraction-->treat with dantrolene to prevent Ca2+ release used clinically to set bones, intubate, surgery; muscle paralysis prolonged action in patients with atypical cholinesterase Hyperkalemia due to intracellular release from ACh receptor channels. High risk for burn and immobilized/surgery patients (ACh receptor upregulation). Cardiac dysrhythmias due to stimulation of cardiac muscarinic receptors (usually bradycardia, sometimes tachycardia in high doses) post-operative muscle pain
Atracurium
Nicotinic Antagonist; muscle relaxant competitive inhibitor of ACh, non-depolarizing. 70% bound prevents muscule contraction; flaccid paralysis AChE inhibitors, reduce the destruction of endogenous ACh, used after surgery to speed recovery can sometimes cause histamine release and allergic reaction
Physiologic antagonism
Occurs when antagonist activates a different mechanism that opposes the effect of the agonist E.g. Agonist inc. effect X, antagonist does something different to dec. effect X --> net = 0 change
The Time-Course of Plasma Concentrations: Single Dose and Multiple Dose Regimens
Relationship of Drug Dose to Plasma Concentration (Cp) and Therapeutic Effect • Single compartment distribution - Drug rapidly equilibrates into volume of distribution • First-order elimination - Drug is cleared at constant fractional rate - Kel is fraction eliminated per unit time Cp = Cpo e ^ -kelt Cp as a function of time Cp(t): Single Compartment with First-order Elimination Linearization of Cp(t) ln Cp = ln Cp0 - kel t y int: lnCpo slope: kel Elimination Half-life Time to eliminate 50% of drug from plasma Dose-independent under first-order conditions of elimination kel= .693/t1/2 Dependent on both Vd and ClT t1/2 = 0.693*Vd/Clt Estimation of Vd single compartment analysis - Administer dose iv • Collect plasma at various times • Measure drug concentrations (Cp) • Estimate Cp at time 0 (Cp0) by extrapolation • Compute Vd = Dose / Cp0 Determined from Cp vs time data after iv administration (see lecture notes for derivation) ClT = ( kel ) (Vd) Clt = .693/t1/2 * Vd How do ClT and Vd in a specific patient affect Cp vs t? Duration of Drug Action • When drug readily distributes to site of action to generate its effect, how is duration of effect related to drug dose? • Note that usually Cp increases with dose, but Vd, ClT and half-life do not change. ln Cp vs time for dose Y, 2Y, 4Y iv administration, 1st order elimination, one compartment distribution, rapidly reversible effect, no active metabolites Exponential increase in dose results in arithmetic increase in duration Doubling the dose increases the duration of action by one t1/2 3* t1/2 Nonlinear Kinetics • Dose-dependence in PK parameters • Saturation of enzymatically mediated clearance • Saturation of plasma or tissue binding site Exceptions to First-Order Elimination • ZEROORDERkinetics - constant reaction rate due to enzyme saturation - 50% biotransformation time increases with concentration - Cp vs time is linear without ln transformation • MIXED ORDER kinetics - Multiple elimination pathways with differing kinetics Distribution of Drugs Drug is administered into the body IV; rapidly distributes entirely into its Vd Drug concentration is calculated Some drugs behave as if the body is made up of two compartments Drug is administered IV and one compartment (V1; plasma and well perfused tissues) has a high concentration quickly, and then the drug distributes slowly into another compartment (V2) Cp (t) of Two-Compartment Model Cp = Ae - (at) + Be - (bt) Cp and Ctissue of Two-Compartment Model ln Concentration concentration in highly perfused tissue (V1) ln Cp concentration in poorly perfused tissue (V2) Duration of Action Dependent on Redistribution • For drugs with multi-compartment kinetics, duration of action depends on distribution into and out of compartment where target is located. • For lipophilic drugs that act in the brain, duration of action depends on redistribution out of brain to slowly perfused tissues. • Duration of action may be short, although elimination half-life is long. Cp is determines Cp?...BOTH absorption and elimination kinetics and the bioavailability Effect of absorption rate on Cp The faster the absorption rate: • the higher Cpmax • the earlier tmax Determination of Bioavailability (F) • Bioavailability (F) is the fraction of the Dose absorbed into the systemic circulation • The bioavailability by a specific route of administration of a specific formulation of a drug, made by a specific manufacturer, is determined by a clinical study of the drug's plasma concentrations • Endpoint data: the AREA under the plasma concentration vs time curve (AUC) Bioavailability (F), the fraction of the dose absorbed into the systemic circulation. Bioavailabilty = AUCpo / AUCiv x 100 Integral Cp = AUC = F (D / ClT) • ClT must be constant during study, so cross-over design used - each subject receives same drug dose in two arms of the experiment Absolute bioavailability: determined for new drug = AUC of noniv dose / AUC of iv dose • Relative bioavailability: determined for generic in comparison to proprietary formulation of drug = AUC of formulation1 / AUC of formulation2 Effect of ka and F on Cp via time above TC Comparison of iv and po Relative Magnitude of ka and kel • t1/2 elimination longer than t1/2 absorption • kel<ka • terminal slope of Cp(t) is same for iv and noniv route and reflects kel PO: elimionation longer than absorption halflife terminal slope of Cp(t) is shallower for noniv than iv route and reflects ka
4 types of exudates
SPHF (expelled from the school of public health, ****) 1. serous: contains few cells, clear, suggests mild vascular injury 2. purulent (pus): many inflammatory cells, no blood 3. hemorrhagic: contains RBCs - implies capillary damage 4. fibrinous: exudate with a layer of fibrin deposited onto serosal surface
Colors
Stopper color Additive Notes Red (glass) No additive. After a clot is formed, serum is collected. Used for toxicology and some chemistry testing. Gold Clot activator, serum separation gel, has a low vacuum which minimizes hemolysis. After a clot is formed, serum is collected. The most common tube for chemistry tests. Lavender or Pink EDTA Allows testing to be done on whole blood because EDTA binds calcium and prevents the coagulation cascade. Lavender top is used in hematology and molecular testing. Pink top is used in blood bank. Green Heparin Allows testing to be done on plasma because heparin inhibits thrombin. Used in some chemistry tests as well as cytogenetic testing. Blue Citrate Allows testing to be done on plasma because citrate binds to calcium and prevents the coagulation cascade. Used in coagulation studies. Gray Glycolysis inhibitor Used in forensics and some glucose studies.
neutrophil chemotactic factors (5 of them)
cause neutrophil migration to site of inflammation 1. bacterial products 2. complement fragments 3. LTB4 (leukotriene B4) 4. IL-8 CXC chemokines 5. PAF (platelet activating factor)
Phthalate esters
VOC used as plasticizers; flexible plastics reproductive toxin in animals - ?human effects
advantages and disadvantages of case control study
advantages: - study of rare outcomes - low cost and short time relative to RCT disadvantages - inability to establish causality; only an association - many potential biases - inability to determine absolute risk of the outcome from drug use, because subjects w/ the outcome are selected for the study - confounding variables
Botulinum toxin
bacterial protein MW = 150k binds specifically to cholinergic nerve terminals, then is internalized into cytoplasm - enzymatically degrades protein factors required for vesicle fusion and ACh release -> no ACh release, local skel muscle paralysis - paralysis for months --> need axonal sprouting to recover adverse effects: - muscle weakness (long-lasting) - difficulty eating/swallowing - paralysis of resp muscles --> death tx of botulism = antitoxin (but doesn't reverse toxicity once botox has entered nerve terminal)
MAO inhibitors
inc. catecholamine levels in nerve terminals; potentiate effects of tyramine (MAO normally degrades tyramine and catecholamines inside the presynaptic nerve terminal; w/o it, inc. catecholamine effects & more risk of tyramine toxicity - hypertensive crisis)
B2 agonist side effects
inc. risk of severe asthma exacerbation & death w/ long term use of lon-acting B-agonists (b2)
Ranitidine H2
increased cAMP used to help with gastric ulcers, gastric hypersecretory conditions
mechanism for mercury poisoning
indoor air pollutant binds to sulfhydryl groups in some proteins, especially in the CNS and kidney effect = tremors, confusion, mental retardation (if in utero exposure), death @ high doses
phagolysosome
ingested bacteria into phagosome; fuses with lysosome; phagolysosome destroys gram negative rod
Lecture 41: Mechanisms of Bacterial Pathogenesis
1. A 15-y.o. male presents to the ED with several days of fever, malaise, and generalized myalgias. On the day of admission, he acutely developed painful swelling of his right wrist. On exam, a lesion is noted on his left shin just below the knee and several other lesions are on his right arm near the elbow. 2. LD50 (lethal dose) for Strain A is lower therefore stain A is more portent. Max Lethality is 100% so does not matter. 3. Surface-Associated Virulence Factors: -Fimbriae/pilli: Adhesion, antiphagocytic -Capsule/slide: Adhesion, antiphagocytic, anticomplement, camouflage -Peptidoglycan (muramyl peptides); immunomodulation, induction of inflammatory mediators -LPS/LOS: Anticomplement, induction of inflammatory cytokines, endotoxic shock systemic inflammatory response syndrome -Teichoic acid: Adhesion, sequester divalent cations, induction of inflammatory mediatorys -Flagella/axial filaments: Chemotaxis, penetration of mucus -Outer membrane protein: Adhesion, sequester iron, intracellular survival, invasion -Surface proteins: Adhesion, binding Fc region of immunoglobulins -Iceberg concept of disease: Classic disease, less severe disease, asymptomatic infection (most) -Early response: does not cross multiplication threshold for disease so no disease -Delayed response: crosses multiplication threshold so some disease shows in 8 days) -Immunodeficiencies increase susceptibility to infection/disease: B cell deficiency leads to more bacterial infections, T cell deficiency leads to more viral/fungal infections, B and T cell deficiency leads to more bacterial, viral, fungal, and protaozoal infections. There are also phagocytic deficiencies and complement deficiencies. AIDS, diabetes, immunosuppressive drugs, genetic disorders, old age, poor nutrition, stress, pregnancy, splenectomy, tobacco use, drug & alcohol abuse, some medications can cause immunodeficiency. Acute infections come and end. Persisitent infections virus stats for a while but symptoms only show at end. Slow virus has an acute symptom phase then a end of life symptoms phase but the middle has low virus production. Stages of disease include 1. incubation period 2. prodrome 3. clinical illness 4. recovery. Stages of bacterial pathogenesis include: 1. transmission and entry 2. evasion of host defense 3. adherence 4. colonization 5. disease 6. host immune response 7. disease progression or resolution. Determinants of bacterial pathogenesis include: 1. method of transmission and entry; infection can shed via conjuctiva, respiration, capillary for arthropods, scratch injury, skin, alimentary tract->urinogential tract + anus. Normal microbiota of conductive, nose, mouth/oropharnx, small intestine, large intestine, vagina, urethra, skin, stomach, and outer ear is huge. 2. Evasion of host defenses include tear lysozyme, respiratory mucus/ciliated epithelium/alveolar macrophages, skin anatomic barrier and antimicrobial secretion, stomach acidiity/flora/bile, washing urine/acidity/lysozyme, vaginal lactic acid. Oral mucosa has saliva, keratin, granular layer, BM, leukocytes, antibodies, blood vessels. Crevicular fluid (IgG,IgM,IgA,proteins, complement, enzymes, electrolytes, b/t/Mac/poly) and salivary gland secretion (IgA, proteins, enzymes, electrolytes) into whole saliva (IgA, IgG, Proteins, Enzymes, Electrolytes, Polymorphs). 3. Adherence to cell surfaces (Pili/fimriae, MSCRAMMS, capsules, LTA) 4. Colonization. 5. Invasion, growth, biofilms (i.e. abscess, erysipelas): Phagocytosis IgG + C3b receptor -> NADPH+Oxidase+Cl,OH,H2O2,O2*. Escapes phagocytosis by inhibiting opsonization, inhibiting chemotaxis, killing phagocyte, inhibiting phagocytosis, inhibiting lysocsomal fusion, escaping lysosome to grow in plasma, resist antibacterial lysosomal action and multiply, block activation by interferon-y. Bacteria can damage tissue by invasion and inflammation (pyogenic (Necrotizing faciitis: Aeromonas hydrophila/Sepsis: Streptococcus pyogenes, Group A Strep) or granulomatous) or with toxin production (EXOTOXIN: secreted, encoded by plasmid or phage genes, very toxic in low concentration, good antigens!, toxoids, act variously some A-B subunit). A unit inactivates elongation factor = prevents protein synthesis = cell death. Hyperactivation: A1-A2 increase adenylate cyclase = increase cAMP = high Na, H2O, Cl, K, HCO3 = loss of cell nutrients = diarrhea. There is super antigen binding to external regions of the T-cell receptor and MHC II right in the middle like a slug. G+ cocci: GI enterotoxin super antigen. G+ rod: GI depolymerize actin, inhibit Act release, inactive respiratory protein. G- rod: GI stimulate adenylate cyclase, Resp inactive protein synthesis, stimulate ac or gc. ENDOTOXIN: not secreted, part of bacterium, encoded by genes on bacterial chromosome, not as toxin as exotoxins, poor antigens, no toxoids or vaccines, causes of septic shock. Endotxoin (Lipid A, LPS on outer membrane of cocci and rod): Activate macrophage (IL-1 fever, TNF fever/hypotension hemorrhagic tissue necrosis , NO hypotension shock), Activate complement Alternative Pathway (C3a: hypotension edema C5a neutrophil chemotaxis), activates tissue factor (coagulation cascade DIC). E:Edema, N: NO D: DIC, O: Outer membrane, T: TNF-a, O: O-antigen/hypotension, eXtremely heat stable, Il-1, Neutrophil chemotaxis , by-products of bacterial growth, immunopathogeneis.
• Describe the mechanism of the anti-inflammatory and immunosuppressive effects of glucocorticoids.
1. Anti-inflammatory Effects Increase in transcription of lipocortin (annexin I, inhibitor of phospholipase A2) and decrease in transcription of inducible COX-2 leads to decreased release of arachidonic acid and decreased formation of PGs and leukotrienes. Increase in transcription of MAPK phosphatase 1 that inactivates the MAPK proinflammatory cascades. Possibly nongenomic effects with more rapid onset of anti-inflammatory action than those mediated through transcriptional effects. Decreased secretion of lipolytic and proteolytic enzymes at site of injury Decreased extravasation of leukocytes due to decreased endothelial synthesis of cell adhesion factors that affect leukocyte localization Decreased fibrosis with reduced production of collagen. 2. Immunosuppressive Effects Increase in transcription of I-kB which binds NF-kB and blocks its transcriptional activity; direct interaction between GC-bound receptor and NF-kB to block transcriptional effects of the latter Inhibition of cytokine secretion by macrophages and T cells. Interleukins 1-3, 6, 8,12, TNFa, GM-CSF, Interferon y. Inhibition of T and B cell replication Decreased IgG production Increased neutrophil release from bone marrow into circulation and reduced extravasation Decreased T and B cells, monocytes, eosinophils and basophils in circulation due to shift into lymphoid tissue. Inflammatory response: PC -Phospholiapse Az (Lipocortin from Cortisol inhibits phospholipase)-> Arachidonic acid -> COX -> prostoglandin/Thromboxones -> Vasodilation Arachidonic acid -> LOX -> Leukotrienes (Cortisol inhibits leukotrienes) -> Neutrophil fx, Phagocytosis, Bacterial killing Immunne Response Antigen -> Macrophage (cortisol inhbits macrophages) -> Interleukin -1 (fever) -> T-cell (cortisol inhibits) -> Interleukin-2 (cortisol inhibits signaling for T-cell proliferation) -> B cell pro -> Ab . Effects on Metabolism 1. Carbohydrates: gluconeogenesis with decreased glucose utilization except in critical tissues; hyperglycemia leading to insulin release 2. Lipids: lipolysis and lipogenesis due to insulin secretion; net effect to increase fat deposition 3. Proteins: catabolism with release of amino acids and decrease in muscle mass C. Cardiovascular Effects 1. Permissive effect to enhance reactivity of smooth muscle to adrenergic amines and angiotensin II; essential for normal CV function; contributes to hypertension on chronic systemic administration for anti-inflammatory or immunosuppressive indications 2. Edema and hypertension from Na retention caused by MC effect 3. Possibly other effects that impair endothelial-mediated vasodilation D. Effects on Bone 1. Negative calcium balance 2. Decreased bone formation through inhibition of osteoblast activity 3. Osteoporosis E. CNS Effects 1. Insomnia 2. Hypomania, psychosis 1. Endogenous hormone: hydrocortisone (cortisol) 2. Synthetic derivatives (modifications at 1,2,9,16 positions): prednisone, dexamethasone, and many others 3. Differences among agents: percent and rate of clearance by biotransformation, duration of action, potency, selectivity for GC versus MC effects, and formulation for oral, topical, inhalation or injectable administration Hydrocotisonne (8-2 hr + selectivity GC vs MC) Prednisone (12-36 hr ++) Dexamethasone (36-72hr +++ selectivity) Replacement Therapy for Endocrine Disorders 1. Adrenocortical insufficiency a. Acute: high doses of hydrocortisone b. Chronic (Addison's disease): physiologic doses of hydrocortisone and fludrocortisone; few adverse effects; need for increased dosage with stress, illness, surgery and co-administration of CYP450 inducers that increase GC clearance . Other Adrenal Disorders a. Cushing's syndrome: 1.) Differential diagnosis: dexamethasone is used to distinguish pituitarydependent Cushing's syndrome from other causes such as an ectopic site of ACTH production or adrenocortical tumors, because it suppresses ACTH production from pituitary cells but not other sites 2.) High doses at time of surgery to remove ACTH-producing tumor b. Genetic disorders: congenital adrenal hyperplasia e.g., 21-hydroxylase deficiency leading to inadequate GC/MC synthesis, and excess androgens; treat pregnant woman to prevent fetal genital virilization C. Non-endocrine Disorders 1. Asthma and chronic obstructive pulmonary disease (COPD) 2. Severe allergic reactions 3. Collagen-vascular disorders, such as rheumatoid arthritis and lupus erythematosus and other autoimmune diseases 4. Dermatologic disorders, such as psoriasis 5. Gastrointestinal inflammatory diseases, such as inflammatory bowel disease (IBD) 6. Emesis following surgery or chemotherapy 7. Cerebral edema associated with tumors 8. Immune cell malignancies such as leukemia 9. Tissue grafts and organ transplants 10. Antenatal administration during premature labor to stimulate fetal lung maturation and reduce risk of respiratory distress syndrome in preterm infants
list the underlying enzyme defects and clinical manifestations of three sphingolipidoses: Tay Sachs disease, Gaucher's disease and Niemann-Pick disease
A. Gaucher disease - autosomal recessive, - carrier rate in general population is 1:200 - carrier rate in Jewish people of Eastern European ancestry is 1:10 Enzyme deficient: glucocerebrosidase (cleaves glu from ceramide). Accumulated substrate: glucocerebroside Major organ(s) affected: Reticuloendothelial cells in spleen, lymph node and bone marrow. Also, in some cases, neurons in the brain. Histology: "Gaucher's cells" in spleen, liver, bone marrow, etc. Unlike other LSD's, Gaucher's cells are not vacuolated but have a fibrillary cytoplasm (crinkled tissue paper). EM - stacks of lipid in lysosomes. Three clinical subtypes. Type 1: (Classic) - Adult type, non neurotropic, storage cells in spleen and bone, 80% cases occur in Jews of Eastern European ancestry, reduced but detectable level of enzyme, longevity is shortened but not markedly.Major clinical findings (Type 1): (i) Enlarged liver (2-3x) and spleen (15x) - protruding abdomens, suppression of appetite due to compression of stomach (ii) Low platelet count - sequestration due to large spleen, bruising and bleeding (iii) Anemia - sequestration, bone marrow replacement by Gaucher cells, fatigue (iv) Low white blood cells - sequestration, susceptibility to infections (v) "Bone crises" - severe bone pain due to insufficient blood supply to bone (due to the accumulation of Gaucher cells) (vi) Bone thinning/fracture - "Erlenmeyer flask" deformity, due to abnormal bone development, flared, flattened distal bones (femur, tibia) rather than normal rounded forms Treatment options: (i) Enzyme replacement (recombinant glucocerebrosidase), dramatic decrease in size of liver and spleen, cost $200,000 annually for life. (ii) Bone marrow transplant, can cure but increased life-threatening risk is prohibitive (iii) Splenectomy, blood transfusions, joint replacement, liver transplantation (iv) Gene therapy Type II: Infantile type, neurotropic, no Jewish predilection, no detectable enzyme activity, death at an early age. Type III: Intermediate between types I and II, juveniles present with systemic disease like type I but also develop CNS disease beginning 2nd to 3rd decade. Level of enzyme is intermediate B. Tay Sachs Disease- Autosomal recessive. - Most common among Ashkenazi Jews. - Heterozygous carrier rate of 1:30. Enzyme deficient: Hexosaminidase A Accumulated substrate: GM2 Ganglioside Major organs affected: Neural tissues and retina (cherry red spot) Histology: Neurons with cytoplasmic vacuoles (distended lysosomes) which by EM look like whorled inclusions (layers of membrane). Clinical: Infants are normal at birth, manifest symptoms by six months, motor and mental deterioration, muscle flaccidity, obtundation, blindness ("amaurotic familial idiocy"). Death ensues in two to three years. Antenatal diagnosis possible by assessing Hex A in cultured fibroblasts obtained from amniotic fluid C. Niemann-Pick Disease- auto recessive Enzyme deficient: sphingomyelinase two forms biochemically: Type A (75-80%) & Type B. Accumulated substrate: sphingomyelin and cholesterol Major organs affected: Reticuloendothelial system of spleen, liver, lymph nodes, bone marrow, GI tract, etc. The brain is extensively involved in Type A deficiency. In Type B, patients have organomegaly but no CNS involvement. Splenomegaly is usually quite striking (ten times normal size). Liver enlargement is usually less impressive. Histology: Macrophages with foamy cytoplasm (numerous small vacuoles). EM reveals concentric "myelin" figures (Zebra bodies). When involved, the neurons of the brain are vacuolated and degenerated. Clinical: May be present at birth but certainly by six months. Infants with protuberant abdomens, failure to thrive, organomegaly progressive deterioration of motor function, may have skin xanthomas (cholesterol, lipid in skin macrophages), "cherry red spot" in retinae of 30 to 50%. Associated with early death (three years). Can be detected antenatally.
Predict the transport mechanism of a drug, based on its Describe the physicochemical features of drug molecules molecular weight, lipophilicity, pKa, and affinity for carriers Explain the factors that affect absorption half-life and bioavailability for parenteral and enteral routes of administration Distinguish the major differences between Phase 1 and Phase 2 biotransformation reactions Infer the mechanism of renal elimination of a drug from its renal clearance Describe the major causes of variability in the volume of distribution and clearance of drugs among individual patients Compare the absorption, volume of distribution, and elimination of protein therapeutics to those of highly polar and highly lipophilic small molecular weight drugs
A. Physicochemical Features of Drug Molecules 1. Molecular weight (small MW drugs <1000 Da, monoclonal antibodies ≈ 150,000 Da) 2. Oil:water partition coefficient (a measure of lipophilicity) 3. pKa (presence of a fixed charge or ionizable group that increases aqueous and decreases lipid solubility; drug with amine residue acts as base and acquires positive charge with addition of hydrogen as pH decreases relative to pKa, drug with carboxylate residue acts as acid and acquires negative charge with loss of hydrogen as pH increases relative to pKa) 3. Physical form (gas, liquid, solid; critical to handling and formulation, vapor pressure of special relevance to general anesthetic agents) 4. Stability in aqueous solution 5. Affinity for proteins (membrane carriers, biotransforming enzymes, or reservoir sites such as plasma albumin; likely to differ for stereoisomers of a drug molecule)
interneuron transmissions
ACh nicotinic
Organophosphates
AChE inhibitor Irreversible AChE inhibotrs via phosphate bond examples: insecticides, sarin Atropine-->stopgap, only blocks muscarinic receptors SLUDGE, neuromuscular blockade, respiratory failure, confusion, coma, convulsions Pralidoxime-->cholinesterase regenerator. Binds organophosphate-inactivated AChE (anionic free site) and changes conformation of organophosphate so it unbinds---> prevents nicotinic and muscarininc responses. Controversial
Which of the following is an appropriate conclusion regarding the association between acetaminophen and Reye's syndrome
Answer: Correct A. Children treated with acetaminophen were less likely to have had Reye's syndrome, and the association was statistically significant. Response Feedback: The odds ratio of 0.07 for acetaminophen suggests that children treated with acetaminophen had a substantially lower risk of Reye's syndrome compared to those not treated with acetaminophen. (This is because children not treated with acetaminophen were usually treated with salicylates, which are associated with Reye's syndrome in children.) This is statistically significant, because the p-value = 0.00001, which is far less than 0.05.
Toxicity of 1st generation antihistamines
At very very high amount; OTC is safe Effects = Atropine-like (antimuscarinic) Fixed, dilated pupils Dry mouth Tachycardia Urinary retention Hallucinations Fever
Agnus castus Many uses in hormonal imbalance disorders Alfalfa Estrogenic, in vivo Aniseed Estrogenic Bayberry Mineralocorticoid Cohosh, black Estrogenic Fucus Hyper-/hypothyroidism reported Ginsengs Estrogenic, human Horseradish May depress thyroid activity Liquorice Mineralocorticoid activity, human; estrogenic in vivo, in vitro Motherwort Oxytoxic Pleurisy root Estrogenic Red clover Estrogenic in vivo Saw palmetto Estrogenic and antiadrogenic in vivo; human use in prostate cancer Vervain Inhibition of gonadotrophic activity Wild carrot Estrogenic
Bayberry Hypertensive, myricitrin mineralocorticoid side effect Broom Hypertensive, alkaloid effect, stated to be contraindicated in hypertensive individuals Capsicum Hypertensive, increased catecholamine secretion Cohosh, blue Hypertensive, methylcytisine has nicotinic action, alkaloid effect Cola Hypertensive, caffeine Coltsfoot Hypertensive, pressor activity Gentian Stated to be contraindicated in hypertensive individuals Ginger Hypertensive Ginseng, Panax Hypertensive, human and in vivo Liquorice Hypertensive, mineralocorticoid side effect Maté Hypertensive, caffeine Vervain Hypertensive
Leukocyte, Role, and WBC type for P-selectin and E-selectin adhesion molecules
Both: Leukocyte = Sialyl-Lewis X Role = Rolling WBC type = PMN, Monos, T cells E-selectin: Role = Rolling *+ adhesion*
Which of the following is an appropriate conclusion regarding the association between salicylates and Reye's syndrome?
Children treated with salicylates were more likely to have had Reye's syndrome, and the association was statistically significant. The odds ratio = 42.8 suggests that febrile children treated with salicylates had 42.8 times the risk of Reye's syndrome compared to those not treated with salicylates. This is statistically significant, because the p-value = 0.00001, which is far less than 0.05.
1. Specify sources, uses, and health effects of toxic agents in the environment.
Environmental pathology refers to the many disorders that occur because of exposure to harmful chemical and physical agents in the immediate environment. These diseases often result from the deleterious activities of people themselves, either individually or collectively, but some are caused by natural phenomena. [1] The study of harmful (or toxic) agents - their distribution, effects, and mechanisms of action - is called toxicology. Toxic agents enter the body through the skin, the lung, or the gastrointestinal tract, and reach the bloodstream, from which they are distributed to other tissues. Once in the body, these agents may be stored or excreted in their original form (which may or may not be toxic), or may first be converted to metabolites. The original agents and/or their metabolites may cause the toxicity. The extent of toxicity varies with the dose of toxic agent as well as the affected individual. [2] The environmental toxic agents that we will discuss here comprise two categories: 1) chemical agents (often called xenobiotics because they are not intrinsic to the individual), which include air pollutants, heavy metals, organic chemicals, tobacco, and alcohol; and 2) physical agents, which may cause mechanical, thermal, electrical, or radiation injuries. Other toxic agents (which will be discussed elsewhere in the curriculum) include infectious agents, firearms, some drugs, and some nutrients or lack thereof. [3] Xenobiotics are metabolized mainly by the cytochrome P-450 enzymes (CYPs, in the endoplasmic reticulum), with generation of reactive oxygen species (ROS) byproducts that promote inflammation. They may be metabolized harmlessly into primary then secondary metabolites, through phase I and phase II reactions, respectively; or they may be converted from nontoxic metabolites into reactive metabolites that affect biologic processes or introduce changes in DNA. If these changes are not repaired - they result in short- or long-term toxicity. Air Pollutants [4] The main xenobiotic outdoor air pollutants, which the US Environmental Protection Agency (EPA) regulates by setting safe upper limits, are: particulates (also known as soot); and the gases sulfur dioxide, carbon monoxide (CO), ground-level ozone (O3, generated by the interaction of nitrogen oxides with ultraviolet light - a photochemical reaction), and nitrogen dioxide. These pollutants are main components of smog (short for smoke + fog), a whitish haze tinged with a yellow-brown color, which sometimes forms over large cities. The main source of smog is the combustion of fossil fuels (gasoline, oil, coal, wood, and natural gas) by motor vehicles, power plants, factories, and homes. Smog components are respiratory irritants that cause inflammation and lung damage, especially in asthma sufferers. [5] Ozone (O3) is a highly reactive oxidant, which forms free radicals that promote inflammation and damage the lung epithelium. Carbon monoxide (CO) is a colorless, tasteless, odorless gas (formed by the burning of carbon- containing material), which is rapidly oxidized to carbon dioxide (CO2). However, when generated in close proximity and high concentration (as for example in automotive fumes in a closed garage), CO can easily form carboxyhemoglobin, outcompeting oxygen, because its affinity for Hb is 2-orders of magnitude higher than that of oxygen. In the case of mild CO poisoning, this oxygen deprivation (hypoxia) causes dizziness, confusion and headache. However, in severe cases, the hypoxia rapidly leads to depression of the central nervous system, heart damage, and death. Particulates are combustion products and mineral dusts derived from major compounds in the earth such as coal, silica and iron. These are harmful if less than 10 μm in diameter and, therefore, too small to be trapped by the nasal hairs or mucociliary lung epithelium. These fine and ultrafine particles reach the lung and are phagocytosed by alveolar macrophages and neutrophils, which then release inflammatory mediators that may cause lung damage (especially with chronic exposure) and, in severe cases, may lead to heart rate irregularities.
Notable examples of adverse effects include:
Ephedra alkaloids (derived from Ephedra sinica or Ma huang) have been commonly combined with caffeine and marketed for weight loss and athletic enhancement [58]. A review of adverse events possibly associated with ephedra use between 1997 and 1999 found episodes of hypertension, arrhythmias, myocardial infarction, stroke, and seizures [59]. Ten events led to death and 13 to permanent disability. Of these 23 reports, nine occurred at recommended ephedra doses in individuals without significant preexisting cardiovascular or neurologic risk factors. Although double-blind, randomized, controlled trials of ephedra-caffeine combinations have shown modest efficacy over placebo for weight loss [60,61], data from 50 ephedra trials showed an estimated 2.2- to 3.6-fold increase in the odds of psychiatric, autonomic, cardiovascular, and gastrointestinal symptoms [62]. There have also been case reports of heart failure in patients taking ephedra [63]. ● Despite ephedra products comprising only 0.8 percent of all dietary supplement sales in 2001, they were responsible for 64 percent of all herb-related adverse events reported to US Poison Control Centers during the same year [64]. In part based upon these data, the FDA on April 12, 2004 banned manufacturers from the sale of products containing ephedra [65]. Some manufacturers subsequently substituted bitter orange (Citrus aurantium) for ephedra in weight-loss products. C. aurantium contains synephrine, an adrenergic agonist similar to phenylephrine and ephedrine, that has been associated with serious cardiovascular and neurologic side effects Plants containing pyrrolizidine alkaloid constituents can lead to liver toxicity secondary to venoocclusive lesions, resulting in parenchymal necrosis, fibrosis, and even cirrhosis (table 7) [68]. The precise mechanism of hepatic injury is unknown but appears to result from the accumulation of toxic metabolites produced via the cytochrome system [69]. The increased concentration of cytochrome P enzymes in the centrilobular region of the liver correlates with the changes seen pathologically. (See "Hepatotoxicity due to herbal medications and dietary supplements".) Consumption of kratom (Mitragyna speciosa), an herb used in self-treatment of opioid withdrawal, can lead to respiratory depression, anorexia, depression, psychosis, and seizures [70]. Overdose-associated hospitalizations and deaths have lead public health officials to detain and consider regulating supplements containing kratom [71,72]. (See "Medically supervised opioid withdrawal during treatment for addiction", section on 'Alternative treatments'.) ● Some herbal treatments are known to be nephrotoxic and should be avoided (see "Nephropathy induced by aristolochic acid (AA) containing herbs") [73]. Aristolochia is a Chinese herb included in weight-loss herbal formulas associated with over 100 cases of nephropathy [74]. It is also a probable human carcinogen associated with urothelial cancers [75]. Herbal products can contain harmful contaminants including heavy metals (see 'Purity' above). These may be incidental contaminants from plant raw materials or the manufacturing process. However, they may be sometimes intended constituents of the product, since several non-Western healing traditions such as traditional Indian (Ayurvedic) and Chinese medicine systems use heavy metals, including lead, for their purported therapeutic efficacy [54,55]. Use of Ayurvedic and/or traditional Chinese medicine herbs, as well as St. John's wort, has been associated with higher blood lead levels among women [76]. At least 80 cases of heavy metal toxicity have been reported from traditional Indian (Ayurvedic) herbal medicine products that contain lead, mercury, and arsenic [55,77-79]. The majority of these cases involve lead and involve products manufactured outside of the United States. (See "Adult occupational lead poisoning" and "Arsenic exposure and poisoning".) The belief among some patients that "more is better" leads to significant side effects and potential harm from ingesting large quantities of herbal products [80]. Toxicities due to overuse have been documented with ginseng and licorice [81].
INTERNATIONAL
Epidemiology — Herbs are commonly used for medicinal purposes throughout the world. Data on this usage come from convenience samples, national surveys, ethnographic studies, market data, and toxicity reports from Canada, Europe, Asia, Australia, the Caribbean, South and Central America, and Africa [21-35]. Europe — In Europe, herbal medicine is frequently referred to as phytotherapy and is commonly integrated with conventional medicine in many countries within the European Union. Sales of over-the- counter herbal medicines in Europe in 2003 were over $5 billion [36]. Herbal products are often used as a first-line therapy for conditions such as benign prostatic hyperplasia in Germany, Italy, and elsewhere. Other studies of use include: ● A nationally representative survey of the German general public found that 65 percent used herbal medicines [37]. German physicians receive medical school training in medicinal herbs and must pass a test on herbal medicine to become licensed. Approximately 80 percent of German physicians regularly prescribe herbs. ● A survey of 21,923 adults in the Northwest region of England found 12.8 percent used one or more herbs [22]. ● Half of Danish preoperative patients reported taking herbal medicines, including ginkgo and echinacea [23]. ● Twenty-seven percent of outpatients in a Spanish gastroenterology clinic had used herbs in the previous year [24]. Asia — Alongside acupuncture and massage, herbs play a significant role in traditional Chinese medicine [38]. Ayurveda, the most common traditional medicine practiced in India, uses over 6000 herbal combinations in its pharmacopoeia [39]. Vietnam, Malaysia, Korea, and other Southeast Asian countries have their own systems of traditional medicine. (See "Chinese herbal medicine for the treatment of allergic diseases".) Developing world — In developing countries, herbal medicines are often less expensive and more accessible than conventional pharmaceuticals. As an example, 78 percent of households in a low-income neighborhood of Managua, Nicaragua reported herbal use [28]. Almost two-thirds of respondents from Brazilian urban primary care clinics reported use of herbal therapies, often due to inability to obtain conventional medicines [29]. Recommendations for herbal use are often given by family members, community elders, village health workers, midwives, or healers. Herbal formulations are often prepared individually for the patient from raw plant materials, instead of being commercially available. In many developing countries, the administering of traditional medicines is often part of an elaborate healing ritual with spiritual or supernatural components [40]. Regulation — In general, regulation of the quality of herbal products is significantly greater in the European Union than in the United States. A 2004 EU directive requires manufacturers of all over-the-counter herbal products to register and license the product with the European Agency for the Evaluation of Medicinal Products. A premarket evaluation of quality and safety of the product is required. Companies need to carry out post-marketing surveillance and report serious adverse events. Indications for these over-the-counter herbal products are for minor conditions not usually requiring a clinician's care. Instead of requiring new rigorous efficacy studies to market a new product, documentation from the medical literature of safety for the relevant condition and reasonable plausibility of efficacy is needed. In countries such as Germany and France herbal medicines are partially or fully reimbursed. The World Health Organization (WHO) developed a Traditional Medicine Strategy "to promote the integration of traditional medicine and CAM (complementary and alternative medicine) into national health care systems where appropriate" [41]. As part of this effort, the WHO distributed a survey about national policies and regulations for herbal medicines to help frame regulatory policies, enhance quality, safety and efficacy, ensure access, and support rational use of these remedies; 141 of 191 member states from all WHO regions responded [42]. Thirty-seven percent of responding nations had herbal medicine regulations in place. Approximately half of the remaining nations were considering implementing regulations. Over two-thirds of countries sold herbal medicines without requiring a prescription. There are relatively few herbal medicines available by prescription only (eg, saw palmetto, ginkgo, St. John's wort). QUALITY AND EFFICACY — Given the regulatory structure for herbal medicines, there is substantial variation in the quality of commercially available products in the United States and elsewhere. Variability in product quality can impact the product's efficacy, safety, and therefore clinical usefulness. Quality — There are multiple determinants of the quality of an herbal product. These factors all impact the ability to insure consistency and standardization of herbal products.
analytic variables for lab testing
- manual vs automated testing - quantitative vs qualitative test results ---> most tests are quantitative and are resulted by MT without review by pathologist ---> some qual and interpretational tests are reviewed by a pathologist - interference --> for tests dependent on optical transmittence; color & other may interfere --> for immunoassays, rarely false positive results can be seen in pts who have heterophile antibodies (human anti-animal antibodies that react with lab antibodies from animals used in testing) - difficulty of a case (some tests may be difficult to interpret either due to equivocal findings, rarity of case, multiple concurrent disease processes, etc.) MT = medical technologist
examples of biologically active proteins
- may be generated by processing of larger, inactive proteins (via proteolysis) e.g. insulin, complement, coagulation proteins
Pharmacology of Anti-inflammatory Steroids
Glucocorticoids A class of steroids with anti-inflammatory and immunosuppressant effects A type of disease-modifying anti-rheumatoid drugs (DMARDs) Principal Adrenal Steroids • Glucocorticoids (GCs): cortisol (hydocortisone), corticosterone • Mineralocorticoids (MCs): aldosterone Regulation of Endogenous Glucocorticoid Synthesis • CRH from hypothalamus stimulates corticotropin (ACTH) release from anterior pituitary • ACTH increases synthesis of GC from cholesterol in adrenal cortex • GC inhibits CRH release and inhibits synthesis of proopiomelanocortin (source of ACTH) Output of endogenous steroids depends on the stimulatory effect of ACTH ACTH acts on a GPCR in the adrenal cortex to activate a signaling pathway resulting in the increased synthesis and release of cortisol GC Selectivity of Cortisol (Hydrocortisone): Equal affinity for GC and MC receptors: Converted to cortisone - in kidney, salivary gland and colon - by 11B hydoxysteroid dehydrogenase so Cortisone has low affinity for MC receptors GC action: Interactionwithcytosolic hGR alpha • Translocationintonucleus • Binding to GRE • InteractionofGRwith transcriptional regulators • Change in gene expression -Inhibitors of arachdon stuff: Increased synthesis of phospholipase A2 inhibitor • Increased synthesis of NF-kB inhibitor (IkB) • Blocked transcriptional effects of NF-kB • Decreased synthesis of adhesion factors that affect leukocyte localization Molecular Mechanisms of Anti-inflammatory and Immunosuppressant Effects of Glucocorticoids Block in release of arachidonic acid and its metabolites - Increased transcription of gene for lipocortin (inhibitor of phospholipase A2) - Decreased transcription of COX-2 Antagonism of NF-KB - Increased transcription of gene for I-kB (inhibitor of NF-kB translocation into nucleus) - Nuclear binding by ligand-bound GC receptor Anti-inflammatory Effects of GCs Blockade of the early manifestations of inflammation pain and vasodilation enhanced vascular permeability and edema extravasation of leukocytes Blockade of later stages of inflammation vascular proliferation fibroblast activation fibrosis and collagen production Immunosuppressive Effects of GCs • Inhibition of macrophage activity • Inhibition of cytokine secretion by macrophages and T cells - Interleukins 1-6,8 - TNFa - Cell adhesion factors • Inhibition of T and B cell replication • Decreased IgG production Greater selectivity GC selective: dexamethasone, prednisone MC selective: fludrocortisone Longer half-life and duration of action Cortisol: duration 8-12 hr Dexamethasone: duration 36-72 hr Therapeutic Uses of Glucocorticoids • Replacement therapy for adrenal disorders • Anti-inflammatory effect RA (rheumatoid arthritis) & LE (lupus erythematosis) • Immunosuppressant effect Autoimmune disorders (RA, LE), organ transplants, or immune cell malignancies Adrenocortical insufficiency - Acute • High doses of hydrocortisone - Chronic (Addison's disease) • Physiologic doses of hydrocortisone and fludrocortisone GC Insufficiency • Anorexia • Nausea and vomiting • Fever • Joint or muscle pain • Postural hypotension GC can be used for: Asthma, COPD, alergic reactions, RA, LE, collagen vasc idsorders, dermatologic disorders psoriasis, GI UC Chrons, cerebral edema, bells palsy inflammation, immune cell malignancies, tissue grafts, premature lungs. • Single large dose relatively safe • Beneficial effects only palliative • Prolonged treatment is NOT safe - Toxicities - Suppression of HPA axis • Abrupt termination is life-threatening Months after stoping GC: ACTH peaks then falls: cortisol palteus: GC-induced atrophy of the adrenal cortex Adverse Effects of Long-term GC Use Infection • Impaired wound healing • Osteoporosis with fractures • Muscle wasting • Hypertension • Hyperglycemia • Altered fat deposition • Cataracts • Ulcers • Behavioral disturbances: psychosis • Slowed growth in children Cushing Syndrome Caused by: • Chronic administration of large doses of glucocorticoids • Tumor of the pituitary or adrenal gland Measures to Reduce Risk of GC Toxicity • Local administration - MDI aerosol delivery with spacer for lung - Nasal sprays for allergic rhinitis - Topical preparations for skin, eye, oral cavity - Injection into joint - Intrathecal for post-herpetic neuralgia - Slow release capsule with high first pass effect for IBD (budesonide) • Minimize use to essential indications, avoid prolonged use, and taper on withdrawal from chronic use Other Immunosuppressants Small, Low MW molecules Purine/pyrimidinesynthesisinhibitors: -(Antimetabolites): Methotrexate (MTX) MTX Mechanism of Action •Inhibition of thymidine-MP synthesis -High dose antineoplastic effect -Reduces the availability of folate for thymidylate and DNA synthesis -Causes arrest of DNA replication and cell division •Inhibition of de novo purine (inosine-MP) synthesis -Low dose antirheumatic effect -Possibly mediated by increased adenosine that acts as the anti- inflammatory agent CalcineurinInhibitor:Cyclosporin Calcineurin inhibitors: Cyclosporine, Tacrolimus • Mechanism: Block T cell signaling for growth and differentiation by inhibiting enzymatic activity of calcineurin required for NFAT induction of T-cell IL- 2 synthesis • Indicated for organ transplants (cyclosporine-first- in-class) • mTORInhibitor:Sirolimus Mechanism: Block protein kinase (mTOR) activity required for cell cycle progression from G1 to S phase in T lymphocytes • Indicated for organ transplants and contained in coronary stents Large, High MW Proteins: Biologics TNFa Antagonists (Infliximab Mab, Etanercept SOlRec) • High molecular weight proteins that bind and block the inflammatory actions of TNFa • IV or SC administration • Long half-lives • Indicated for arthritis and inflammatory bowel disease • Increases the risk of infection • Expensive • IL-6 Antagonist Abatacept (ORENCIA) - IgG1 like protein that binds to Antigen-Presenting Cell (APC) and prevents T cell activation - Approved for rheumatoid arthritis - Increases risk of infection Mechanism • Two signals are required for T cell activation. • Signal one: T-cell receptor binds to the major histocompatability complex antigen (MHC) on the antigen presenting cell (APC) • Signal two: a co-stimulatory ligand B7 (CD80/CD86) on the antigen presenting cell binds the co-stimulatory receptor on the T cell (CD28). • Abatacept inhibits the binding of B7 (CD80/CD86) to CD28 and T cell activation • Anti-Integrin Antibody (Natalizumab) Integrin a4 Antagonist Natalizumab • 95% humanized antibody targeting integrin a4 on lymphocytes • Blockslymphocyteinteraction with adhesion molecules (MAdCAM-1) on vascular endothelium in inflamed regions of intestine • Approved for multiple sclerosis and Crohn's Disease (Vedolizumab)
• Describe and compare sources of information about drugs and
I. New Drugs and their Development A. Approval Procedures: The Food & Drug Administration approves the marketing of all new drugs that are sold in the U.S., and monitors their use afterward. The timeline of implementation of U.S. drug legislation, the basis for current FDA regulations, is provided below: 1902 Vaccines brought under federal control. 1906 Food and Drug Act prohibits interstate commerce of drugs mislabeled with respect to content. 1936-7 Elixir of sulfanilamide disaster: more than 100 people die because of toxicity of the diluent, diethylene glycol, used in a new formulation of the first synthetic antimicrobial agent sulfanilamide. 1938 In response, Congress requires that new drugs be proved experimentally to be safe. 1951: Amendment differentiates between prescription and non-prescription (OTC, "over-the-counter") drugs; standards of labeling and safety apply to both. 1961 Thalidomide, a new sedative, had been found to cause phocomelia (limb malformations) in several hundred babies born in Europe, before the drug had won FDA approval for marketing in the U.S. This prompted passage of: 1962 Kefauver-Harris Amendments to 1938 FDA legislation: Drugs must be proved experimentally to be effective for indications claimed by manufacturer (proof of safety still required). Drug advertisements, as well as labeling, must list all ingredients and side effects. Patients in clinical trials of investigational new drugs must give their informed consent to participation in the trials. Institutional Review Boards charged by later regulations to determine that: Subjects' rights and welfare are adequately protected. The risks to any subject are outweighed by potential benefits to the subject or by the importance of the new knowledge to be gained from the experiment. The subject's informed consent will be obtained by non-coercive methods. The FDA's authority to regulate drugs comes from the Interstate Commerce clause of the U.S. Constitution (Article I.§ 8, ¶ III). That is, a drug may not be shipped from one state to another if intended for use in some way other than the therapeutic uses recommended by the manufacturer, approved by the FDA, and listed in the labeling. The current FDA approval process includes: 1. PRECLINICAL TESTING: Most new drugs are developed in laboratories of pharmaceutical companies, where they are screened in animals. Toxic drug levels and the probable safe dosage range in humans are determined at the same time. Before clinical testing can begin, the sponsor (as the pharmaceutical firm is called as far as new drug development is concerned) must submit to the FDA a NOTICE OF CLAIMED INVESTIGATIONAL EXEMPTION FOR A NEW DRUG, called the "IND" for short. In this application, the sponsor describes the composition of the drug, its source, and how it is made. The sponsor also presents the results of all animal studies to document that they were sufficient to indicate that the drug shows promise of being medically useful in humans, and that no human subject will be exposed to unreasonable risks when taking the drug as an experimental subject. Finally, the IND contains a detailed protocol for the planned testing in human subjects. The sponsor must wait 30 days after submitting the IND to enable the FDA to review it to make sure that subjects will not be exposed to unjustifiable risks, although the wait is usually much longer. 2. CLINICAL TESTING: Once the IND has been approved, clinical testing proceeds in three phases monitored by the FDA: PHASE I is directed toward determining the drug's effects; how it is absorbed, distributed, and eliminated and the pharmacokinetic parameters; its safe dosage range; and its appropriate route of administration. The tests may involve from 20 to 80 subjects, both normal healthy volunteers and patients. PHASE II is the first controlled study of the new drug and may involve several hundred patients with the targeted disease(s). Such studies are designed to permit evaluation of the drug's efficacy, although safety testing continues in both animals and human subjects. PHASE III studies are designed to assess the drug's safety, efficacy, and most desirable dose range in treating a specific disease in a large number of patients, often several thousand. This step requires more extensive controls, such as a placebo or sometimes a comparator drug, and is expected to provide a full evaluation of the drug's potential role in therapy. When Phase III is completed and the sponsor believes the drug is effective and safe under specified conditions of use, the company applies to the FDA for permission to market the drug with a NEW DRUG APPLICATION, or "NDA." Technically, the FDA has 180 days in which to review the data in the NDA; the supervising scientists at FDA will have been following the clinical testing all along, but the final review period may last as long as two or three years. The review is prioritized and more rapid for a drug that offers the potential for innovative therapy, as compared to one that is similar in approach to drugs already on the market (see below). The review mechanism is intended to insure that the new drug's benefits outweigh its risks to an appropriate degree. Preparation of the package insert, or as it is called formally, the labeling, is part of the process leading to final approval of the NDA. (Note that evidence as to efficacy is generally in comparison to placebo and not a comparator drug for the same indication. See discussion of the problem of lack of comparative efficacy data in drug labels in NEJM 361:1230, 2009, posted in the folder for this session.) PHASE IV: After approval, the sponsor must maintain records relating to production methods and the drug's safety and efficacy and must report previously unexpected hazards or lack of efficacy. The FDA can reverse its earlier approval and require withdrawal of the drug from the market. Or in cases where marketing is allowed to continue, the FDA may require a change in the label to add additional warnings about risks of adverse effects (referred to as a "black-box warning") or outcomes of additional clinical trials. Conversely, prescription drugs found to be very safe can sometimes be approved for over-the-counter sale (e.g., H-2 receptor blockers and proton pump inhibitors for GI indications). SUPPLEMENTAL NDA: Once the patent on a drug expires (usually after 17 years, although the life of a patent is often much shorter because it is granted before testing begins), any other company that wishes to market it must submit a "Supplemental NDA" to acquire the necessary marketing permission. Approval of such an application requires that the new "generic drug" formulation must contain the same amount of the same active ingredient as the patented drug, and the bioavailability of the formulation must be within plus or minus 20 percent of that of the original product. Efficacy does not have to be reestablished if the labeling for the new product will not include any new clinical indications for the drug's use. These studies are therefore much less expensive to conduct than are Phase 1-3 trials (1984 Drug Price Competition and Patent Term Restoration Act). The study data typically includes the relative bioavailability of the generic formulation compared to the proprietary version, tested in fewer than twenty healthy subjects with a cross-over design. The Biologics Price Competition and Innovation Act of 2009, passed as part of the PPAC Act of 2010, establishes guidelines for FDA approval of "biosimilars", protein therapeutics manufactured by non-innovators once patents expire on the original product. These guidelines and required studies are more complicated due to the greater complexity of the protein drugs, compared to the small molecular weight therapeutics, and their manufacture in a biologic system that adds variability to the molecular structure. Treatment IND: In 1987, the FDA established new procedures, called the Treatment IND, so that promising investigational drugs that are still in late Phase II or mid-Phase III clinical testing can be administered to patients with immediately life threatening conditions (e.g. AIDS, advanced heart failure, herpes simplex encephalitis, etc.) or serious chronic diseases (e.g., Alzheimer's, multiple sclerosis, etc.) well before general marketing of the drug begins. All the usual safeguards to both experimental subjects and patients remain intact. The AIDS epidemic was a major factor for instituting this regulatory change. In 1991 the FDA established a system of prioritizing NDAs that was designed to shorten the review time and accelerate the marketing of agents that represented an important therapeutic gain. Submissions are categorized as 1P (highest priority), 1S (modest therapeutic gain), 4S (lowest priority).
Describe the difference between controlled cell growth (hyperplasia, hypertrophy) and uncontrolled growth (neoplasia)
I. Neoplasia - "new growth": The process of uncoordinated cell growth exceeding the limits established for normal tissues due to loss of responsiveness to normal growth controls. Such growth gives rise to neoplasms. Tumor - by strict definition a tumor is a "swelling" that can be produced by edema, hemorrhage or neoplasm. Today, most people restrict the definition of tumor to meaning a neoplasm. The study of tumors constitutes the medical subspecialty of oncology (oncos = tumor, logos = study of) II. Before discussing the different types of neoplasms, some important considerations regarding cell growth should be reviewed: 1. Hyperplasia - an increase in the number of cells comprising a particular tissue or organ. Hypertrophy - refers to an increase in the size of individual cells making up a particular tissue or organ. Both lead to an increase in size (volume) of the organ involved.
Explain how dose, bioavailability, rate of absorption, apparent volume of distribution, total clearance, and elimination half-life affect the plasma concentrations of a drug after administration of a single dose.
I. Time Course of Plasma Concentrations A. Relationship between Plasma Concentration and Drug Effect Understanding the impact of pharmacokinetic parameters, including volume of distribution, total clearance and bioavailability, on the plasma concentrations of a drug is important to predicting drug concentrations in individual patients and interpreting data when plasma samples are evaluated as part of dosage monitoring. (The methods for determining pharmacokinetic parameters are provided below to enhance understanding of these values. They are determined for individual drugs in studies conducted prior to approval for marketing.) Ultimately, the key prediction is the onset time, peak magnitude, and duration of therapeutic and toxic effects of a drug. That requires understanding the factors that affect how levels rise to reach a minimum level for an effect (a threshold concentration), how high the levels rise to produce a peak effect, and how long the levels stay above the threshold to generate a duration of the drug's effect. When a drug rapidly equilibrates into its target site, produces a reversible effect, and is eliminated by first-order kinetics, the duration of effect increases in direct proportion to log dose and doublings of dose increase duration by one elimination half-life. This relationship will be explained more fully after first considering the impact of pharmacokinetic parameters on plasma concentrations as a function of time for three common types of drug administration, a single bolus dose, continuous intravenous infusion, and multiple dosing regimen. B. Time-Course of Plasma Concentrations (Cp) following Administration of a Single Dose (D) 1. Case with instantaneous (e.g., intravenous) or highly rapid absorption relative to elimination a. Single compartment model: drug rapidly equilibrates into its volume of distribution 1) First-order elimination: plasma concentrations decline according to first-order kinetics, i.e. the elimination rate from plasma is proportional to the plasma concentration; Cp declines exponentially with time; the curve is linearized by converting Cp into ln values; the fraction eliminated per unit time is the elimination rate constant (kel)*, a term expressed as time-1 such as per minute or hour. dCp/dt = kel Cp Cp = Cp0e^-kelt a) Determination of elimination rate constant and elimination half-life*: The elimination rate constant kel for a drug is the slope of the ln Cp vs. time relationship. The plasma half-life of a drug is determined by its elimination rate constant (t1/2 = 0.693/kel). As long as the elimination kinetics are first-order, the half-life is constant and independent of dose. (To estimate the half-life from Cp data rather than compute it from kel, just find the time interval for any Cp to decline to 1/2 of that Cp.) b) Determination of apparent volume of distribution: The Vd is determined by extrapolating to time 0 the line of best fit for ln Cp vs time; the antilog of ln Cp at time 0 is designated as C0. Then, Vd in ml or liters = Total dose in mg or gm/ C0 in ug/ml or mg/l To express Vd as a percent of body weight, assume that 1 liter is equivalent to 1 kg; divide the Vd in liters by body weight, and then multiply by 100%. Similarly, if relative dose administered is known (i.e., the dose per kg or other unit of body weight BW) but not the total dose, Vd as fraction of BW = Relative Dose/ C0 c) Determinationoftotalclearance: Total clearance (elimination rate by all routes and mechanisms normalized for the plasma concentration) is the amount of drug (CpVd) eliminated per unit time divided by the plasma concentration; therefore, ClT = (kel) (CpVd) / Cp = (kel) (Vd) = [ 0.693/t1/2] (Vd) So, having determined the volume of distribution and the elimination rate constant, the total clearance can be determined. (Remember that ClT and Vd are independent parameters and are the determinants of the elimination rate constant and half-life.) d) Determination of nonrenal clearance (ClNR): If total clearance and renal clearance are determined from plasma and urine samples as described previously, then clearance by nonrenal routes (which includes biotransformation) can be estimated from: ClNR = ClT - ClR 2.) Kinetics of zero-order* elimination: in this case elimination rate is constant and t1/2 is dose-dependent (example: ethanol); this phenomenon occurs because of enzyme saturation such that a constant amount of drug is biotransformed per unit time rather than an amount per unit time proportional to its concentration. In this case a plot of Cp vs time is linear and not exponential. Cp=Cp0 -k0t
DOSE-EFFECT RELATIONSHIPS AND THE PHARMACOLOGY OF CHOLINERGIC AND ADRENERGIC AGENTS
Interpret dose-effect relationships to determine the potencies, efficacies, and selectivities of agonists, partial agonists, and antagonists. Evaluate drug interactions including competitive and noncompetitive antagonism. Compare the selectivities of different drugs to guide the choice of drug therapy. Describe the pharmacology of adrenergic and cholinergic agents. Describe how the potency and efficacy of drugs at receptors located on different tissues contribute to their therapeutic effects, side effects, and toxicities. Interpret clinical signs and symptoms (related to cholinergic or adrenergic phenomenon) for diagnosis of drug overdose, and determine the appropriate choice of antidote based on pharmacologic or physiologic antagonism. Communicate with colleagues, using appropriate terminology and reasoning skills, to solve pharmacologic problems.
What's in a Chem 7 panel?
Na+ Cl- K+ HCO3- Cr GLU
NETs
Neutrophil Extracellular Traps - product of a dying neutrophil (extrudes chromatin) - NETs composed of strands of chromatin and proteins - bacteria stick to the chromatin (b/c of its antibacterial peptides) - *stuck bacteria trapped and doomed to enter phagolysosome*
tNSAIDS
No selective, traditional NSAIDS Ibuprofen - older agents that inhibit both COX1 and COX 2 - cox2 inhibition is thought to mediate the antipyretic, analgesics, and anti-inflam actions (what we want to block) - cox 1 inhibition largely (not entirely) causes many adverse effects, e.g. Ulcer
Opioid Pharmacology Opiate Opioid Narcotic
Opiod receptor ligans: Agonist: Morphine, Met-Enkephalin Antagonist: Naloxon, Naltrexone Agonist-Antagonist: Nalorphine, Buprenorphine Alkaloids: Natural (miorphine, codeine), Semisynthetic (heroin, hydromorphone), sunthetic (meperidine, methadone, fentanyl). Pro-Opiomelanocortin (POMC): B-Endorphin, MSH, ACTH Pro-Enkephalin A: Met-Enkephalin, Leu-Enkephalin Pro-Enkrephalin B: Dynorphin A Pro-Orphanin: Orphanin FQ Nociceptin Endomrophins 1 and 2 Choosing Opioids via Pharmacokinetics; Long: Methadone, Levorphanol Medium: Morphine, Hydromorphone Short: Meperidine, Fentanyl, Remifentanil Receptors: u1/2 MOP: Sufentanil, B-endorphin, Endomorphin-1 k1/2/3 KOP: Nalorphine, Dynorphin-A g1/2/3 DOP: Enkephalin, DPDPE ORL NOP: Nociceptin Opioid Receptor Structure: VII cross 3 intracellulat loop receptor Acute opiod effects: Analgesia • Respiratory Depression • Sedation • Vasodilation • Tolerance • Bradycardia • Nausea, Vomiting • Miosis • Smooth Muscle Spasm • Skeletal Muscle Hypertonus Chronic: tolerance + dependence presynaptic u,k,g cause low transmitter release u recptor on post synaptic cause hyperpolarization Imacts limbic system, descending modulation, and dorsal horn (inhibit SG cell) Fentanyl Hepatic CYP3A4,5 clearance Codeine CYP2D6 clearance Codeine O-Demethylation to Morphine • A minor pathway (<10%) of codeine metabolism, but it accounts for nearly all opioid activity • CYP3A4 and glucuronide metabolites (80%) are mostly inactive Mrophine GlucuronDemethyl clearance Morphine-6-Glucuronide: pain tollerance high then leaves Remifentanil Esterase extrahepatic clearance - pethidine 2D6 Phenotype: -Codeine: Inactive parent + active metabolite • Oxycodone: Active parent + active metabolite • Tramadol: Active parent + inactive metabolite 1. Almost all opioids are cleared by the liver 2. Many opioids have polar active metabolites, so most likely to cause problems in renal failure 3. Polymorphisms in clearance may be bad or good, depending upon - Effect of metabolite - Activity of parent drug Analgeisa is always accompanied by some respiratory effect Morphine will depress CO2 response with higher doses N-Methylnaltrexone (MNTX) • Highly polar quaternary ammonium compound that does not enter the CNS • Reverses opioid-induced constipation, delayed gastric emptying, & urinary retention • Does not affect CNS actions like analgesia, respiration or pupil constriction Opioid Cardiovascular Effects • Vasodilation - Centrally-mediated - Venous and Arterial • Bradycardia • No Important Effects on - Myocardial Contractility - Vascular Response to Catecholamines - Sympathetic Reflexes Opioid-Induced Histamine Release Duration & intensity of effect ↓ • Change may be profound • Cross-tolerance to other opioids • Opioid receptor changes? - Phosphorylation & internalization - ↑MAP kinase, ↑adenylyl cyclase, ↑PLC • Non-opioid receptor mechanisms? - Hyperalgesic effect (NMDA, NO) - Neuroinflammation (immune responses) • Opioid receptor changes? - Phosphorylation & internalization - ↑MAP kinase, ↑adenylyl cyclase, ↑PLC • Non-opioid receptor mechanisms? - Hyperalgesic effect (NMDA, NO) - Neuroinflammation (immune responses) Tolerance Affects Analgesia and Respiratory Depression Physical Dependence Abstinence • Nausea, Vomiting • Restlessness • Yawning • Gooseflesh • Mydriasis • Rhinorrhea • Lacrimation • Diaphoresis • Anorexia • Weight Loss • Hyperthermia • Drug Seeking • Behavioral Pattern of Drug Use • Harm to Individual & Society • Overwhelming Involvement - Obtaining Drug - Using Drug • High Tendency to Relapse After Withdrawal Methadone Maintenance Advantages • Long-acting (once a day) • Oral (no needles) • Reduces drug seeking - Prevents abstinence - Cross-tolerance to heroin • Regular contact with caregivers • Agent of choice for detoxification Requires special license, highly regulated • Separate from medical care • Limited availability • Stable and unstable patients mixed • No privacy; Social stigma • Tied to clinic; Employment difficult • Can't "graduate" from program - Buprenorphine - u Partial Agonis (merge with morphine causes downward slope) Buprenorphine Maintenance for Heroin Abusers • Buprenorphine feels "morphine-like" • Potent agonist (~30 X morphine) • Strong antagonist - May cause withdrawal sxs. - Blocks effects of injected heroin • Low-moderate abuse liability - Marketed with naloxone (Suboxone®) - Treatment by primary care physicians -Morphine for postoperative pain: dose range 3-60mg Factors Affecting Opioid Requirement • Pharmacokinetic - CYP2D6 polymorphism - Glucuronidation? • Pharmacodynamic - Type and Location of Pain - Co-existing Disease - Concomitant Drug Treatment - Culture, Expectations, Setting - Age, Gender - Receptor polymorphism -OPRM-1Gene and Single Nucleotide Polymorphisms Most frequent mutation is A118G - Asn to Asp substitution at position 40 - Frequency 10-20% in Caucasian, Hispanic - May be as high as 35-50% in Asians! • Implications of A118G not clear - Greater miosis from M6G in man - Reduced analgesia from M6G in man Are Opioids Inappropriate for Chronic "Benign" Pain? • Poor Response? • Pain Behavior? • Tolerance, Dependence? • Drug Diversion? • Addiction? Heroin Use? Mortality?
Prostaglandins
PGE2 - pyresis (febrile) - inc. pain and edema in response to autocoids PGE2 & PGF2a - inc GI motility and secretion - GI cytoprotection ** - Dec gastric secretion - uterine contraction Both = cox derivatives from arachidonic acid metabolism
Prostacyclin vs TXA2
PGI2: - Inhibits platelet aggregation - Vasodilation - made in endothelial cells TXA2: - stimulates platelet aggregation - vasoconstriction - made in platelet Both COX derivatives from arachidonic acid metabolism
Methotrexate (MTX)
Purine/pyrimidine synthesis inhibitor (Another immunosuppressant; antimetabolite) Mechanisms: 1. inhibits thymidine-MP synthesis - high dose = antineoplastic effect - reduces availability of folate for thymidylate and DNA synthesis - causes arrest of DNA replication and cell division 2. Inhibition of de novo purine (inosine-MP synthesis) - low dose antirheumatic effect - possibly mediated by inc. adenosine that acts as the anti-inflammatory agent
Do you believe that both norepinephrine and Alpha interact with receptors in the tissue? Is it the same receptor for both agonists? Give the reasons for your answers.
The observation of a monotonic, symmetric log concentration-response curves suggests that both norepinephrine and alpha interact with receptors. This is supported by the observation that it is possible to achieve competitive inhibition. The KB of X as an antagonist of norepinephrine is similar to its KB as an antagonist of alpha. This observation suggests that norepinephrine and alpha may interact with the same receptor. This might be confirmed by examining more competitive antagonists of X and alpha. While similar KBs for a single antagonist might perhaps be a coincidence, this is less likely if the same correspondence holds for multiple antagonists.
2. Relate mechanisms of action of toxic agents in the environment to their effects on health.
[6] Major indoor air pollutants include formaldehyde, asbestos fibers, and radon. See table for sources and toxic effects. Pollutant Formaldehyde (a gas) Foam insulation, glues, wood products Asthma, eye/nose/throat irritation, contact dermatitis, nasopharyngeal cancer (rarely) Asbestos fibers (silicate minerals) Insulation, floor & ceiling tiles, before banned in 1970 Mesothelioma (cancer of lining of pleural or abdominal cavity), lung fibrosis, lung cancer Radon (radioactive gas derived from uranium, greatest single source of background radiation) Soil (high conc. in some basements), uranium mines Lung cancer [7] Major toxic heavy metals include lead, mercury, arsenic, and cadmium. Sources, toxic effects, and Metal Lead Water, lead paints (banned in US 1978), leaded gasoline (banned in US 1996) Hematologic, skeletal, neurologic, GI, renal; children > adults (>50% vs ≤15% absorption) Binds to sulfhydryl groups in proteins & blocks Ca metabolism [8] Lead (Pb), the 6th substance regulated by the EPA, has a variety of toxic effects, especially in children, impairing both cognitive and physical development. One consequence of lead poisoning is poor remodeling of cartilage and bone trabeculae, which can be seen on radiographs as radiodense "lead lines" in the epiphyses (the ends of long bones, which are separated from the main part of the bone by cartilage during periods of longitudinal growth Mercury Contaminated fish (methyl mercury), dental amalgams (metallic mercury vapor) Tremors, confusion, mental retardation (if in utero exposure), death (if high doses) Binds to sulfhydryl groups in some proteins, especially in CNS & kidney Arsenic (historical murder weapon) Soil, water, wood preservers, herbicides Acute GI, cardiovasc. & CNS damage, death (if high amt. ingested); hyperpigmentation & hyperkeratosis; lung, bladder & skin cancers Trivalent arsenic replaces phosphates in ATP → inhibits mitoch. oxid. phophoryl'n [9] Arsenic, which can contaminate ground water, can cause hyperkeratosis (abnormal thickening of the dermis), which may lead to skin cancer. Cadmium Nickel-cadmium batteries → water, soil, food Obstructive lung disease, kidney damage, lung cancer (from occup'l exposure) Increased ROS production?
.Teichoic Acid
a. Water-soluble polymers (fiber-like) of glycerol or ribitol phosphate covalently linked to peptidoglycan in the outer layer of Gram-positive cell wall and extending from it. Fibers penetrating the peptidoglycan layer and covalently linked to lipid in the cytoplasmic membrane are called lipoteichoic acid. . Induces sepsis caused by certain Gram-positive bacteria by activating the same pathways as LPS. c. Mediates attachment of Staphylococcus aureus to mucosal cells.
all adrenergic rec. inc. cAMP second messenger except
a1 = inc. PLC, DAG, IP3 a1 = *dec* cAMP
drugs to treat wide angle glaucoma
a1 agonist for vasoconstriction, a2 agonist for reduced secretion and inc. fluid outflow epinephrine, phenylephrine also B blockers
drugs for resuscitation after cardiac arrest
a1 agonist, epinephrine (vasoconstrict to keep blood near heart during compressions)
drug to reduce symptoms of opioid withdrawal
a2 agonist
hallmark cell of acute inflammation vs chronic
acute = neutrophils (not in chronic) chronic = fibroblasts (not in acute) macrophage/monocyte, lymphocyte, eosinophils, mast cells all in *both*
clonidine
alpha 2 selective agonist (centrally active, since a2 activation reduces CNS symp tone)
why does our patient with infection become short of breath?
because of leakage of plasma proteins
low MW lipophilic drugs administered into ______ high MW drugs administered into ______
blood (abs rate depends on flow to that organ) lymph (slow absorption rate for high MW)
classification of burns
by depth superficial (formerly 1st degree) - limited to epidermis - red, dry, painful partial thickness (formerly 2nd degree) - epidermis + part of dermis destroyed - red, moist (blisters), painful full thickness (formerly 3rd and 4th degree) - epidermis + dermis destroyed - anesthetic (no pain) - not capable of regeneration - high risk of infection
how do we measure inflammation quantitatively?
by measuring acute phase reactants - e.g. C-Reactive Protein (will inc 5-500x with inflammation) called "acute phase reactants" but measure chronic inflammation (triggered acutely by IL-6; present in chronic)
5 sections of the clinical laboratory
chemistry hematology microbiology blood bank point of care (+ sendout/reference lab and IT)
C3a and C5a
complement cause migration of neutrophils to site of inflammation both: release histamine from mast cells causing vasodilation & inc. permeability; result = anaphylaxis C5a: chemotaxis, esp of neutrophils; and activation of lipoxygenase pathway of arachidonic acid (results in leukotrienes and lipoxins) C3a: opsonizes bacteria for phagocytosis
NO
inhibits platelet aggregation; vasodilation, inhibits wbc recruitment,
nicotinic ACh channel structure
ligan-gated ion channel 5 subunits (a, a, B, g, y) excitatory rec. that transports Na+, K+, Ca++ activated in milliseconds *prolonged exposure evokes refractory period refractory period = desensitized state in which agonist is bound but channel is closed (depolarizing muscle blockers) - rec. gradually resets after agonist dissociation
C3b
opsonization of bacteria; release of histamine
specificity
out of all the actual normal tests out there, how many did the test pick up? TN/(TN + FP) good for confirmation tests - high specificity will reliably tell you if you're negative
therapeutic uses of B antagonists (B blockers)
propranolol (b1 and 2) , metoprolol (b1) , cardeviol (b1, b2, a2) - CHF management - reducing mortality after MI (reduce arrhythmias) - hypertension (dec. CO, dec. renin - B1 activation inc. renin release; antag = block renin) - relief of angina (to control cardiac oxygen demand) - cardiac arrhythmia tx (inc. AV nodal refractory period) - hyperthyroidism - anxiety - particularly "stage fright" - migraine prevention - open-angle glaucoma - treat pheochromocytoma (need to block a1 before B-blockers, because B2 block of circulating E would exacerbate hypertension)
why use NMJ blocking agents
to block parasymp nicotinic cholingeric ability to excite muscles at NMJ - used in surgery to promote skeletal muscle relaxation, usually for brief unpleasant procedures e.g. tracheal intubation, maintain controlled ventilation, paralysis of skel muscle in area of surgery, to set fractures two types of blockers: depolarizing (non competitive) and non-depolarizing (competitive)
PHARMACOLOGICAL BASIS FOR DRUG SELECTION: EVALUATING THE BENEFIT AND RISK OF ASPIRIN-LIKE DRUGS
• Distinguish the advantages and disadvantages of evidence from case-control, randomized controlled trials, and meta analyses • Interpret data on efficacy and toxicity using odds-ratios, absolute and relative risk, analysis of variance, and chi-square tests • Describe types of bias and confounding factors in case-control studies • Explain limits of evidence from randomized controlled trials, including length of study, choice of subjects, dosing regimen, measured endpoints, and comparator drug(s) or placebo • Access point-of-care resources to quickly identify the best available evidence to inform a decision on the choice of analgesic treatment
What type of cell fight against parasites and what cytokine does it produce to kill multicellular parasites?
- eosinophil - major basic protein
Immunosuppressive effects of glucocorticoids
- inhibition of macrophage activity - inhibition of cytokine secretion by macrophages and t cells (IL-1-6,8; TNF-a; cell adhesion factors) - inhibition of T and B cell replication - Dec. IgG production
characteristics of malignant tumor
- lack of differentiation of cells - cellular pleomorphism - nuclear pleomorphism - inc. nuclear cytoplasm ratio - prominent nucleoli - aneuploidy (abnormal DNA content) - hyperchromasia of nuclei - abnormal mitosis - tumor giant cells - anaplasia
where do ROS come from? how do they kill pathogen?
- oxygen derivatives, main source = leukocytes - breakdown products from aerobic respiration - MPO and iNOS help to make them types: OCl-, 'OH, OONO' OH NO! They go kill bacteria :)
Therapeutic uses of glucocorticoids:
- replacement therapy for adrenal disorders - anti-inflammatory effect (RA, lupus) - immunosuppressant effect (autoimmune disorders, organ transplants, immune cell malignancies) Non-endocrine disorders that use GCs: - asthma, COPD - severe allergic runs - RA, lupus (collagen-vascular disorders) - dermatological disorders (psoriasis) - GI diseases (UC, crohn's) - cerebral edema w/ tumors - neural inflammation (bell's palsy) - immune cell malignancies like leukemia or lymphoma - tissue grafts and organ transplants - prematurity to inc. lung maturation
Benefits of Ginger
-0.5, 1, or 1.5 supplementation 2x daily --> significant reduction in acute nausea during day 1 of chemotherapy - ginger one hour before and 3 and 8 hours after start of chemo significantly reduced incidence of acute and delayed Messi - reduction of nausea up to 24 hours after chemotherapy with ginger supplementation (1.5g 4x daily)
Lecture 38: Bacterial Gene Expression and Transfer A dreaded superbug found for the first time in a U.S. woman This STD is becoming 'smarter' and harder to treat Perdue Aims to Make Chickens Happier and More Comfortable Perdue Sharply Cuts Antibiotic Use in Chickens and Jabs at Its Rivals Mew guidelines released by the Infectious Diseases Society of America (IDSA) and Society for Healthcare Epidemiology of America (SHEA) and published in the journal Clinical Infectious Diseases.
-ART IN US 2014: first snapshot of burden of ab-res germs on human health (2 million; 23k die per year; most deaths in healthcare setting/nursing homes). -National Action Plan for Combating AB-Res Bacteria: slow emergence, prevent spread, strengthen surveilance, advance rapid diagnotic tests, accelerate research for ab, vaccines, treatments, improve international collaboration, reduce in CRE, MRSA, and CDiff (prevent spread of threat, eliminate ab use in a animals, increase surveillance) 2020: Reduce 50% incidence CDiff, reduce 60% CRE hospital-acquired, maintain gonorrhoeae below 2%, reduce 35% MRSA in hospital acquired, reduce 50% MRSA total, reduce 25% Salmonella, reduce 15% TB, reduct 25% pneomocol in youth + elderly. BMC appropriate AB us Sterwardship more practical; less focused on cost-savings. -Law School Guides Global Effort to Create New Antibiotics CARB-X - $350 million to combat antibiotic-resistant superbugs -Definition of virulence gene, pathogenicity island, Differential expression of virulence genes, Examples of signals that regulate bacterial gene expression -The Lac Operon: An inducible operon under positive and negative regulation -Quorum sensing for bacteria in biofilms (plaktonic; adhesion; acyl-HSL signal, mature biofilm) -4 major sources of DNA that can be transferred between bacterial cells: 1. Plasmids 2. A simple transposon contains insertion sequences (IS) that include a transposase (tnp) gene flanked by inverted repeats. A composite transposon contains additional gene(s) 3. Bacteriophages 4. Bacterial DNA from Lysing Cells 5. Conjugation F+ cell 6. Lytic Phage and Generalized Transduction: These phage can infect new cells, but this will not result in more phage. 7. Transformation (free dan in enviornment: Homologous vs. Non-homologous Recombination) 1. Tranformation: Take up naked DNA (SHiN: S pneumonia, H inf B, Neis) 2. F+ - F- : Incorp sex pilus 3. Hfr - F-: F+ via Her cell 4. Transposition: DNA jump from one to another Transduction: Packaging phage then excision and insertion (Group A Step ET, BT, CT, DT, ST)
II. Gene Exchange in Prokaryotic Cells A. DNA is often exchanged among bacterial cells via a variety of mechanisms and may result in genetic alteration of bacteria. These mechanisms may result in no effect on the bacteria, deleterious effects, or they may increase the virulence of bacteria. There are 4 major types of DNA that can be transferred between bacterial cells:
1. Plasmids a. Small, extrachromosomal replicons that replicate independently of the bacterial 38-2 genome; they have their own ori. b. Circular, double-stranded DNA ranging in size from 1.5 to 400 kbp. c. Carry genetic information that is usually NOT necessary for essential bacterial functions, but can provide an advantage under certain selective conditions; e.g. antibiotic resistance genes in the presence of the target antibiotic. 2. Transposons a. Pieces of DNA that can move easily from one site to another within or between the DNAs of bacteria, plasmids, and bacteriophages; e.g. "jumping genes" b. Can include genes for drug resistance enzymes, toxins, or other factors. c. Consist of 4 domains: inverted repeats on each end which play a role in integration of the transposon into the recipient DNA, a gene for the enzyme, transposase, which mediates excision and integration, a repressor gene whose product regulates synthesis of transposase, and the extra gene (e.g. antibiotic resistance gene). d. Are not replicons—cannot replicate autonomously (no ori)! They replicate as part of the DNA into which they insert. e. When transposons "jump" and insert into a new piece of DNA they can have a variety of effects, including causing mutations in a gene into which they insert or altering the expression of genes near the insertion site. 3. Bacteriophages a. Viruses that infect only bacteria. b. May have a DNA or RNA genome. c. Sometimes bacterial DNA gets incorporated into the phage genome or into the phage virus particle and gets transferred to a new bacterial cell when the phage infects that cell. 4. Bacterial DNA from dying bacterial cells a. Bacteria which are dying often "leak" their contents, including DNA, into the environment. This DNA can be randomly taken up by other bacterial cells and may be incorporated into the recipient cell's chromosome. B. Mechanisms of DNA transfer between bacterial cells 1. Conjugation a. Process that results in the transfer of DNA from a donor cell to a recipient cell; requires a specialized sex pilus. b. Plasmids are most frequently transmitted by conjugation. Only plasmids that contain special genes, called tra genes, can be transferred by this process. They are referred to as "self-transmissible" or "conjugative" plasmids. c. Some conjugative plasmids can "mobilize" non-conjugative plasmids. 38-3 d. Example: F (fertility) plasmid (F factor) contains genes required for conjugation, including the pilin protein gene. Pilin forms the sex pilus which mediates attachment of the donor cell to the recipient cell. i. The donor (F+, male) cell binds to the recipient cell (F-, female) via the sex pilus and a single strand of the F plasmid is transferred from the donor to the recipient. The complementary strand is synthesized in the recipient cell so that the recipient becomes a male, F+, donor cell. e. Example: R factor plasmids contain antibiotic resistance genes--often multiple and different genes. 2. Transduction a. Process that results in the transfer of bacterial DNA between cells via bacteriophage. b. Review of bacteriophage life cycle: i. Lytic phages kill the cells they infect by lysis. ii. Lysogenic (temperate) phages may enter a lytic life cycle, or a lysogenic life cycle in which the phage genome becomes incorporated into the bacterial chromosome. c. Two kinds of transduction: i. Specialized transduction results from the excision of a lysogenic phage genome from its integrated state in the bacterial genome and by mistake, some of the adjacent bacterial DNA is excised with the phage genome. The phage genome, with the additional bacterial DNA, is packaged into phage virions and transferred to a new cell infected by the phage. The "extra" bacterial DNA may then become incorporated into the newly infected cell's genome, along with the lysogenic phage, and be expressed. Several toxins expressed by pathogenic bacteria are actually encoded by genes on phage, so that only bacteria that are infected with the toxigenic phage are pathogenic! Examples: diphtheria toxin, botulinum toxin, cholera toxin. ii. Generalized transduction results when phage are being assembled during a lytic infection and during packaging of the phage genome, small pieces of bacterial DNA are packaged into virions instead of phage DNA. The phage virions are released, infect new cells, and transfer the bacterial DNA to a new cell. 3. Transformation a. Process that results in the transfer of bacterial DNA between cells by one cell taking up fragments of DNA released from another cell and incorporating them into its genome. b. Only certain bacteria appear to be naturally "competent" to take up exogenous DNA from the environment, and in nature this process probably does not play a significant role in disease. c. In the laboratory, prokaryotic and eukaryotic cells can be made to take up exogenous DNA in genetic engineering experiments. 4. Once DNA has been introduced into cells by any of the above mechanisms, it may integrate into the host cell chromosome by one of two recombination mechanisms. Each mechanism involves different enzymes. i. Homologous (legitimate) recombination: 2 pieces of DNA with extensive homologous regions bind to each other in these regions and exchange pieces by breakage and ligation; i.e. basically a substitution of one piece for the other. ii. Nonhomologous (illegitimate) recombination: 2 pieces of DNA with little or no homology exchange pieces of DNA; usually produces insertions and/or deletions. Ex. insertion of transposons and lysogenic phage into the bacterial genome.
I. Expression and Regulation of Virulence Genes in Bacteria A. Virulence genes 1. Encode factors that help bacteria successfully infect the host and cause disease by enhancing invasion and colonization, or by helping the bacteria evade the host immune response. Examples of virulence factors include pili, capsules, toxins.
2. RegulationofVirulenceGenes Virulence genes are often expressed only in response to specific signals, like changes in environment that occur when a bacterial cell is transferred from the outside of a human host (from a fomite or food) into the host. A change in temperature is often a signal that induces changes in bacterial gene expression. In general, genes that are not expressed all of the time are called "regulated genes", in contrast to "constitutive" or "housekeeping" genes that are expressed all of the time. a. Transcription of genes may be under negative control which means that they are constitutively expressed unless a repressor protein is bound to the operator and inhibits transcription. b. Transcription of genes under positive control are not expressed unless an apoinducer is bound to the operator so that transcription is enhanced. c. Genes which are involved in a similar function, like virulence genes and others, are often organized so that they are close together in an operon that is regulated by a single operator, so there is coordinated expression of these genes. i. Operons can be inducible or repressible. ii. Pathogenicity islands in bacteria are an example of an operon in which genes involved in a similar function or structure, usually related to virulence, are clustered and expressed together, e.g. Type secretion systems d. Examples of signals that regulate virulence genes: i. Tetracycline is an antibiotic whose presence can induce the expression of tetracycline resistance genes in some bacteria. ii. Quorum sensing involves the expression of genes in response to signals reflecting the density of bacterial cells. Bacterial cells secrete and respond to these quorum sensor molecules. Some scientists call this a form of bacterial communication! Quorum sensing plays a critical role in the formation and maintenance of biofilms, and may be a useful target for antibacterial agents. iii. Iron concentration
odds ratio
= ad/bc (++ x -- / +- x -) 95% confidence interval of OR - determined by sample size in each cell (larger size = smaller confidence interval) - interpretation of 95% confidence interval: --> if it includes 1.0, then NO assoc of drug use with effect --> if >1, effect more likely with drug use --> if <1, effect less likely with drug use
Cp_ss
= k0 / Cl_T (at steady state, input = output) k0 = infusion rate Cpmax ss = Cpmin ss + C0 = Cpmin ss + (MD/Vd) MD = maintenance dose Cp avg = (FD/T) / Cl_T
Examine the odds ratios and 95% confidence intervals in Table 2. What do they suggest about the association between these analgesics and risk of renal failure?
A. There is a statistically significant association that appears to be dose-dependent. None of the 95% confidence intervals include the null value, so all of the associations appear to be significant. In each case the odds ratio is greater for those who took more analgesics, so there seems to be a dose-dependent increase in risk.
Physostigmine penetrates CNS--drug of choice for atropine poisoning atropine/scopalamine/ belladonna poisoning Treatment of Alzheimer's disease Treatment of myasthenis gravis Neostigmine quaternary amine, doesn't penetrate CNS Acceleration of rcovery from nondepolarizing muscle relaxants; treatment of bladder atony (inability to urinate due to loss of muscle tone)
AChE inhibitor Carbamate Ester--form reversible covalent bonds with AChE penetrates CNS--drug of choice for atropine poisoning quaternary amine, doesn't penetrate CNS SLUDGE, neuromuscular blockade, respiratory failure, confusion, coma, convulsions
Cholinergic Drugs Sympathetic - exit from thoracic and lumbar region Parasympathetic - exit from cranial and sacral areas
Acetylcholine - ACh (cholinergic receptors) ACh Nicotinic (N) Muscarinic (M) Nicotinic postganlionic M on heart N on SM N on Epinephrine Norepinephrine - NE (adrenergic receptors) NE a1, a2, b1, b2 PS:, converse energy, bradycardia, vasodilation, low bp, high RBF, increase urine, increase salivation, I, low respiration, increase motlirty Sym: - Expenditure of energy - Tachycardia - Vasoconstrictor predominance - Blood pressure increased - Renal blood flow decreased - Urine output decreased - Salivation reduced - Respiration increased - GI motility and secretions reduced LOW HR: PS ACH M HIGH HR: S NE B1 HIGH GI: PS ACH M LOW GI: NE A2 block PS so no Ach no M GI low PS: Short Ciliary nerves to Spincter Pilillae contraction Iris sphincter muscle: Parasympathetic (miosis) S: Opthalmic nerve long ciliary nerve dilator iridis (Iris dilator muscle: Sympathetic (mydriasis)) Point and Shoot BLOOD VESSELS HAVE ONLY SYMAPTHETIC INNVERVATION Primarily parasympathetic NS Predominant Tone except blood vessels and sweat glands (sympathetic cholingergic) Dom PS: Hear (B1>B2 SA B1>B2 contractility), Iris (a1 dilates), Ciliary muscle (b2 contracts) GI tract (a1,a2,b1,b2 increases motility, a2 incrrases secretion, a1 relaxes sphincters), Urinary bladder (a1 ejaculation spincter, b2 bladder) Salivary glands(M,a,a1), Liver (b2,a1 increase sugar release into blood sym, a1-b3 increase fat cell lipolysis, kidney a1b1 increase renin). Dom Sym: Arterioles Veins(a1,a2,b1,b2 in organs and skin contract, b2 in muscle relaxes) NE, Sweat Ach. Sym nerve: a2 lower NE release PS: a2 lower Ach release In humans, the release of acetylcholine is responsible for which of the following postganglionic sympathetic responses? a. Activation of sweat glands
norepinephrine Adrenergic Agonist
Agonist a1=a2; B1>B2 (a2 are primarily in the CNS, NE does not typically cross BBB) a1: restoring blood pressure (overdose of hypotensive agent, spinal damage or anesthesia)
Hyperglycemic Devil's claw Stated to be contraindicated in diabetics Elecampane Hyperglycemic Figwort Similar constituents as Devil's claw Ginseng, Panax Hyperglycemic Hydrocotyle Hyperglycemic, human Liquorice Hypokalemia aggravates glucose tolerance
Alfalfa Hypocholesterolemic, in vivo Artichoke Hypocholesterolemic, in vivo, human Cohosh, black Hypocholesterolemic, in vivo Fenugreek Hypocholesterolemic, in vivo, human Garlic Hypocholesterolemic, in vivo, human Ginger Hypocholesterolemic, in vivo Hydrocotyle Hypercholesterolemic, in vivo Plantain Hypocholesterolemic, in vivo Scullcap Hypocholesterolemic, in vivo Tansy Hypocholesterolemic, in vivo
carvedilol (and labetalol)
Antagonist B1, B2, & a1 treatment of cardiac arrythmias, reducing mortality after MI, maintaining cardiac output and tissue perfusion in shock, treatment of heart failure, treatment of hypertension, angina, stage fright, hyperthyroidism symptoms, migraine prophylaxis, glaucoma management of heart failure bronchoconstriction, bradycardia, exacerbation of angina, fatigue, cold extremities, potentiation of epinephrine vasoconstriction, precipitation of heart failure (if incorrectly used), new onset diabetes
If it is appropriate to do so, and the data permit, determine KB -- the concentration of a competitive antagonist required to half-saturate its receptors -- for X and Y as antagonists of norepinephrine. If values for KB cannot or should not be calculated, explain why not. Example: KB for X as an antagonist of Alpha was calculated to be 1.45 µM. (Should "KB" be called "apparent KB"?) 3 = 1 + .X/Kb 2 = .1/Kb .1/2 = a'/a = 1 + [B]/Kb
As antagonists of norepinephrine, the KB can be appropriately computed for X, a reversible competitive antagonist, but not Y, a noncompetitive (or irreversible competitive) antagonist. Recall that the KB of a competitive antagonist can be estimated as follows: Use the ED50 for NE + X/EC50 for NE alone as a'/a. The concentration of X is 2 uM. Therefore, the KB for X is 1.42 uM. KB determined from dose-ratio analysis using measures of effect in vitro is a good estimate of the actual dissociation constant of the antagonist for its receptor binding site, and is therefore not referred to as an "apparent" K value.
buprenorphine partial u agonist; high affinity but limited efficacy kAntagonist
B-endorphin u/k agonist
Describe the factors that determine the time-course of systemic accumulation of a drug administered by continuous infusion or multiple doses, including the steady-state concentrations and the time to reach steady-state.
C. Effect of Continuous Infusions or Multiple Dosing on Time-Course of Plasma Concentrations 1. Infusion kinetics One approach to maintaining a desired therapeutic level of a drug is to administer the agent by intravenous infusion. Drug delivery may be controlled by gravity-regulated drip of the agent into i.v. tubing or by use of an infusion pump. a. When a drug is administered at a constant rate (k0) and its elimination follows first-order kinetics, the concentration of drug in the plasma rises exponentially and reaches a steady-rate or plateau level (CSS)*. Cp = CSS (1-e-kelt) b. At steady-state the INPUT RATE = OUTPUT RATE. The input rate is k0, which may be expressed as the total dose (D) divided by the length of the infusion (T). The output rate in the case of first-order elimination is the total amount of drug in the body (CSSVd) times the elimination rate constant (kel). k0 = CSSVdkel Therefore, the plasma concentration at steady-state can be predicted as follows: CSS = k0 Vdkel Total clearance equals the elimination rate constant (kel) times the volume of distribution. Therefore, the plasma concentration at steady- state (CSS) is directly proportional to the input rate (k0) of the drug and inversely proportional to its plasma clearance (ClT). CSS = k0 ClT c. The rate of achieving steady-state depends only on the elimination half-life of the drug. Half the CSS level is achieved in one t1/2, and about 94% of CSS in four t1/2. d. Because of the lag in achieving steady-state when a constant infusion rate is administered, a loading dose may be given to achieve a therapeutic effect more quickly. This may be especially important for a drug with a long elimination half-life, because of the delay in reaching steady-state. If the loading dose is as follows, Loading dose = CSS Vd then the plasma concentration will instantaneously reach the steady-state level, and that level will be maintained, as long as the infusion continues. As drug is eliminated from the loading dose, it is replaced by drug in the infusate. Note that the steady-state level achieved with a continuous infusion is determined by the infusion rate and is NOT affected by the size of a loading dose.
. Bacterial Metabolism A. Bacteria cannot reproduce without a source of energy and the building blocks of cellular constituents (e.g. amino acids, carbohydrates, lipids). B. Minimum requirements for growth are a source of carbon and nitrogen, an energy source, water and various ions. Iron is also an important requirement.
C. Growth requirements and products of metabolism are often used to classify bacteria 1. Autotrophs: can use inorganic chemicals for their energy and carbon source. 2. Heterotrophs: require organic carbon sources. 3. Need to know these specific requirements to culture successfully for lab diagnostic tests. 4. Some bacteria are obligate intracellular parasites and cannot be cultured in the absence of a eukaryotic cell host. Hey, you already know 2 of these bacteria from the last lectures—do you remember them? D. Some by-products of bacterial growth contribute to pathogenesis by destroying tissues; e.g. acids, gas, etc. E. Aerobic and Anaerobic Growth 1. The growth of most medically important organisms is enhanced by the presence of oxygen, which acts as the hydrogen acceptor in the final stages of energy production catalyzed by the flavoproteins and cytochromes of the electron transport system. By the way, do you remember where this process takes place in a bacterial cell? 2. Organisms are often classified based on their ability to grow in the presence of oxygen: a. obligate aerobes: require oxygen for growth. Ex. Mycobacterium tuberculosis, Nocardia b. microaerophiles: require oxygen at low concentration. c. obligate anaerobes: cannot grow in the presence of oxygen (usually > 10%). Ex. Clostridium, Bacteroides d. aeroteolerant anaerobes: do not use oxygen, but can grow in its presence. e. facultative anaerobes: can grow in the presence or absence of oxygen. Ex. Staphylococcus, Streptococcus 3. Aerobic growth produces 2 toxic molecules that can generate hydroxyl radicals which can damage proteins, DNA, lipids, etc. Cells have specific enzymes to deal with these toxic molecules: a. Superoxide (O2-) is converted to oxygen and hydrogen peroxide by the enzyme, superoxide dismutase: 2O2- + 2H+ ---- O2 + H2O2 b. Hydrogen peroxide (H2O2) is broken down into water and oxygen by the enzyme, catalase: 2H2O2 ---- 2H2O + O2 c. Obligate anaerobes generally do not have catalase nor superoxide dismutase! 4. Some organisms require CO2 for optimal growth; they are referred to as capnophilic, e.g. Campylobacter species are capnophilic and microaerophilic.
Tay-Sachs hexosaminidase sphingolipid-->ganglioside hypotonia; cherry red spot
CNS, retina, autonomic nerves, heart, liver, spleen "onion-skin" membranes
Purity — Reports of herbal medicines containing pharmaceuticals have occurred. Notable examples include the combination product PC-SPES used for prostate cancer that was found to contain DES, warfarin, and indomethacin [53]. Reports of lead, mercury, and arsenic contamination in imported traditional Chinese [54] and Indian [55-57] herbal products have also occurred. (See "Adult occupational lead poisoning" and "Arsenic exposure and poisoning".) In the study discussed above that used DNA barcoding (see 'Accuracy of labeling' above), of 21 products that contained the herbal ingredient listed on the label, seven contained other plant species as well [48].
Efficacy — Prior to 2000, a number of predominantly European studies suggested efficacy for common herbs such as echinacea for upper respiratory infection, saw palmetto for benign prostatic hyperplasia, ginkgo for dementia, and St. John's wort for depression. However, more recent adequately powered, rigorous, double- blind, placebo-controlled trials of standardized well-defined preparations suggest the contrary. (See "Clinical use of echinacea" and "Clinical use of St. John's wort" and "Clinical use of saw palmetto" and "Clinical use of ginkgo biloba".) Several herbal medicines and dietary supplements evaluated in controlled trials show therapeutic promise. Larger, well-designed studies with standardized preparations are needed: ● Soy products (Glycine max) for treating hypercholesterolemia. (See "Lipid lowering with diet or dietary supplements", section on 'Soy'.) ● Ginger (Zingiber officinale) for antiemetic efficacy in various situations that can produce nausea and vomiting (eg, postoperative, chemotherapy, motion sickness, pregnancy). The majority of studies show ginger to be more effective than placebo, although safety in pregnancy has not been adequately proven. (See "Prevention and treatment of chemotherapy-induced nausea and vomiting in adults", section on 'Complementary therapies' and "Motion sickness", section on 'Ginger' and "Treatment and outcome of nausea and vomiting of pregnancy", section on 'Ginger'.) ● Probiotics for various gastrointestinal conditions such as ulcerative colitis, pouchitis, infectious diarrhea, and irritable bowel syndrome. (See "Probiotics for gastrointestinal diseases".) ● Fish oils containing omega-3 fatty acids such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) for reduction in cardiovascular risk, primarily through favorable effects on risk of arrhythmias. (See "Fish oil and marine omega-3 fatty acids".). SAFETY — Safety issues for herbs include adverse effects and drug-herb interactions. Asking patients about herbal medicine use and potential side effects will improve their recognition. In the United States, adverse events related to herbal products can be reported to the US Food and Drug Administration (FDA) MedWatch program via telephone (800-FDA-1088), online, fax (800-FDA-0178), or mail. Adverse effects — Our knowledge about adverse effects of herbs comes predominantly from case reports and clinical trials. Few systematic studies of safety have been completed. Several tables are prepared, reviewing the effects of commonly used herbal medications on glucose metabolism (table 2), lipids (table 3), hormones (table 4), blood pressure (table 5), and the heart (table 6).
Compare first and second generation H1 receptor antagonists with respect to selectivity for H1 receptors relative to other Gprotein coupled receptors. H1 receptor antagonists:Diphenhydramine (1st Gen), Loratadine (2nd Gen),Ibu/Asp Acetaminophen (Nonopioid analgesic), Apririn/Ibuprogen (NSAID), Celecoxib (COX2 inhibitor), Methotrexate (small/low MW antiinflammatory/immunosupressant), Infliximab (large/high mw biologic agent TNFa inhibtor), Hydrocortisone/Cortisol (endogenous glucocorticoids), Cortisone, Prednisone, Dexamethasone (synthetic glucocorticoids).
Histamine Antagonists: 1. Distribution and storage of histamine: Stored in secretory granules in mast cells and basophils; slow turnover; degranulation by endogenous (bradykinin, complement components C3a and C5a) and exogenous substances (antigen interaction with IgE, some basic drugs such as morphine). Fast turnover in enterochromaffin-like cells of the gastric mucosa, where release is regulated by neural and hormonal input, in histaminergic neurons of the CNS, and in the epidermis. 2. Physiological and Pathological Roles for Histamine: A. Allergy and anaphylaxis: particularly itch, urticaria, and angioedema; minor role in bronchospasm B. Gastric acid secretion: released from enterochromaffin cells in response to vagal and gastrin stimulation to cause H+ output from parietal cells C. CNS role: involved with arousal, neuroendocrine release (ACTH, vasopressin), thermoregulation, eating and satiety D. Hypotension: due to drug-induced release from mast cells (e.g. morphine) 3. Classification of Histamine Receptors and Responses Multiple G-protein coupled histamine receptor subtypes have been identified. There are many clinically important antagonists for the H1 and H2 subtypes. IMP: H1 (IP3/DAG) 2-methylhistamine (Agonist) + Diphenhydramine loratadine (Antagonist) H2 (cAMP) 4-methylhistamine (agonist); ranitidine (antagonist).
Mechanism for how celecoxib (and possibly older NSAIDs) can inc. CV risk
In platelets, there's no COX2, only cox 1, so TXA2 production goes unchecked - extra platelets and blood clotting (TXA2 stimulates platelet aggregation and vasoconstriction) In endothelial cells, COX2 inhibition decreases pGI2, which leads to dec. in PGI2-induced vasodilation and inhibition of platelet aggregation --> more platelet aggregation; vasoconstriction Unchecked COX 1 in platelets = inc. TXA; inhibited COX 2 in endothelial cells = dec. PGI2 --> result = inc. clotting and vasoconstriction; adverse CV events more likely - celecoxib is contraindicated for patients with CV disease
II. Classification of Bacteria
It is difficult to classify all bacteria into clear-cut categories. Various classification methods are used, depending in part, on the purpose. A. Nomenclature 1. Bacteria are given 2 names (usually Latin) denoting their genus and species a. Ex. Escherichia coli 1. The name is italicized or underlined because it's Latin. 2. The first name refers to the genus (plural: genera) and is capitalized, "Escherichia". 3. The last name refers to the species (plural: species) and is not capitalized,"coli". 2. Sometimes it is necessary to distinguish strains or to identify a new strain of a particular bacterial species, e.g. during epidemics. This is done by "subtyping" an isolate using methods described below (biotyping, serotyping, phage typing, genotyping, or antimicrobial susceptibility testing, etc.). Ex. E. coli O157:H7, the most common strain that can cause hemolytic-uremic syndrome (HUS) vs. E. coli O26, the strain implicated in a recent outbreak of infections acquired from eating at various Chipotle restaurants: http://1.usa.gov/298C6xT B. Phenotypic Classification 1. Macroscopic morphology a. Colonial appearance: Many different bacterial species exhibit characteristic colonial morphologies when grown on agar plates, which can be used to make a presumptive identification. Colonies may be pigmented or not, rough or smooth, glistening or dull, flat or raised, or even have a distinguishing odor. Growth of some bacteria is associated with the secretion of factors which cause the lysis of red blood cells. When bacteria are inoculated on agar medium containing red blood cells, they can be characterized as α-, β-, or -hemolytic: a-hemolytic: incomplete hemolysis of red blood cell leads to greenish-brown colored zone surrounding + under colony b-hemolytic: complete hemolysis to RBC leads to clear/colorless zone around colony y (non)-hemolytic: No hemolysins are produced and no lysis of red blood cells occurs.
Acetylcysteine was administered intravenously
LFTs during hospital stay AST (20-48 u/L ) •Day1:110 •Day2:280 •Day3:400 • Day 5: 2010 • Day 7: 3050 ALT (10-35 u/L) •Day1:105 •Day2:250 •Day3:324 • Day 5: 1500 • Day 7: 2,800 Bilirubin & Prothrombin Bilirubin (0.3-1.0 mg/dl) •Day 1: 0.9 • Day 2: 1.8 • Day 3: 3.0 • Day 5: 8.3 • Day 7: 15.8 Prothrombin Times •D 1: 11.9 (WNL) • D 2: 15. 5 (prolonged) • D 3: 20.2 (prolonged) • D 5: 28.6 (prolonged) • D 7: 34.1 (prolonged) Bilirubin elevation is an indicator of significant hepatocellular injury. Its elevation, in association with elevated transaminases, points to clinically important drug induced liver disease. Prolonged Prothrombin times indicate significant hepatocellular damage Hepatocytes synthesize most coagulation factors . PT reflects function of factors comprising the classic extrinsic pathway, eg VII, X, V, II & fibrinogen. Decreases in Vit K dependent II,VII, IX, X are earliest
• Compare aspirin, ibuprofen, and acetaminophen with respect to therapeutic and toxic effects.
Mechanism of Action: Arachidonic Acid Catabolism and Effects of its Derivatives Prostaglandin E: increased pain and edema in response to autacoids such as bradykinin and 5-hydroxytryptamine; pyresis Prostaglandin E, F: uterine contraction in vivo, increased intestinal motility and secretion, decreased gastric secretion, gastric mucosal protection Prostacyclin: inhibition of platelet aggregation, vasodilation Thromboxane A2 : platelet aggregation, vasoconstriction HETE: chemotaxis of leukocytes and alveolar macrophages Leukotrienes: role in anaphylaxis, in cardiogenic and endotoxic shock; increased vascular permeability, bronchoconstriction; chemotaxis of leukocytes Phosphilpid in membrane -Phospholipase A- Arachidonic Acid -Lipoxygenase- 5-Hete Hete 5-Hete -Leukotriene A4- LTB4 and LTC4-F4 Arachidonic Acid -Ccloxygenas- Endoperoxide PgG2 Prostaglandin E2F2, Thromoxange TxA2, Prostacyclin PgI2
Muscarine
Muscarinic Agonist mushroom poisoning treat with atropine causes SLUDGE toxicity as well as bronchoconstriction, bradycardia, hypotension
Nicotine
Nicotine Nicotinic Agonist tertiary amine, can cross BBB, rapid acting Atropine for bradycardia, benzos for seizures toxicity stimultes both S and PS systems (interneurons for S)--->abdominal pain, nausea, diarrhea, disturbed vision, weakness, mental confusion; central stimulation: convulsion, coma, respiratory arrest; skeletal muscle depolarization via receptor desensitization
Carbachol/Carbamylcholine
Nicotinic; Muscarinic Agonist quaternary amine, doesn't penetrate cell membranes, esterase resistant muscarinic properties used for pupil contraction for opthalmological surgery
Acetominophen
Non-opioid, nonnarcotic analgesic agent Antipyretic and analgesic activity *no* anti-inflammatory activity - relatively weak COX inhibitory action compared to salicylates and NSAIDs - in analgesic doses, its potency, t1/2, and duration of action are similar to salicylic acid (major metabolite of aspirin) - lacks peripheral side effects observed with other COX inhibitors (no platelet effect, little GI toxicity) Mechanism: - analgesic and antipyretic actions due to *reversible COX inhibition in CNS* as compared to peripheral sites - lack of anti-inflammatory effect possibly results from its *poor ability to inhibit COX in the presence of peroxides found in sites of inflammation* Tx Uses: - mild to moderate pain, fever - NOT anti-inflammatory and less effective than NSAIDs in some conditions (e.g. Chronic inflam conditions like RA) - preferable antipyretic analgesic for pts at inc risk of NSAID toxicity - drug of choice for children w/ viral infections to dec. fever (Reyes syndrome = risk of NSAIDs in kids)
Pharmacological antagonism
Occurs @ receptor level - 3 types: 1. Reversible competitive (same site, conc matters, dec. potency aka inc EC50, same efficacy) 2. Noncompetitive (different site, insurmountable, same potency, dec efficacy) 3. Irreversible competitive (same as noncompetitive, but usually result of covalent binding of antagonist to receptor; effect of drug may long out-last its presence in the body; need to make new receptor to get back to normal)
Understand the concept of prematurity and its associated entities (neonatal respiratory distress syndrome, necrotizing enterocolitis, and intraventricular and germinal matrix hemorrhage).
Prematurity is considered the second most common cause of neonatal mortality (primary cause are congenital anomalies), and is defined by a gestational age of less than 37 weeks and weight of less than 2500 grams. The American College of Obstetrics and Gynecology (ACOG) estimates that 12% of all births in the United States are preterm deliveries. Major risk factors for prematurity include: - Preterm premature rupture of placental membranes (PPROM). - Intrauterine infection: inflammation of placental membranes (chorioamnionitis) and umbilical cord (funisitis). The most common microorganisms are Ureaplasma urealyticum, Mycoplasma hominis, Gardnerella vaginalis, Trichomonas, gonorrhea, and Chlamydia. - Uterine, cervical and placental structural abnormalities: Uterine distortion (e.g., uterine fibroids), compromised structural support of the cervix ("cervical incompetence"), placenta previa, and abruptio placentae. - Multiple gestation (twin pregnancy). Many of the causes of preterm labor and prematurity can result in fetal growth restriction, making them especially vulnerable to several complications, including: Neonatal respiratory distress syndrome (hyaline membrane disease) Necrotizing enterocolitis Sepsis Intraventricular and germinal matrix hemorrhage Long-term complications, including developmental delay. 1. Neonatal Respiratory Distress Syndrome (RDS) Immaturity of the lungs is the most important cause for this condition to develop. The incidence of RDS is inversely proportional to gestational age. An estimated 24,000 cases of RDS are reported annually in the United States and improvements in management of this condition have sharply decreased deaths due to respiratory insufficiency from as many as 5000 per year a decade earlier to less than 900 cases. The main defect in RDS is a deficiency of pulmonary surfactant leading to collapsed lungs, progressive atelectasis and reduced lung compliance resulting in a protein/fibrin-rich exudate in the alveolar spaces with the formation of hyaline membranes. The fibrin-hyaline membranes constitute barriers to gas exchange, leading to carbon dioxide retention and hypoxemia. Hypoxemia further impairs surfactant synthesis, and a vicious cycle occurs. Grossly, the lungs are of normal size, solid, airless, and reddish purple. Microscopically, the alveoli are poorly developed or collapsed. Necrotic cellular debris is present in the terminal bronchioles and alveolar ducts and becomes incorporated within eosinophilic hyaline membranes lining the respiratory bronchioles. In uncomplicated cases, recovery occurs within 3 or 4 days. High concentrations of oxygen (positive pressure ventilation) administered for prolonged periods of time (oxygen-derived free radicals) causes retrolental fibroplasia (retinopathy of prematurity) and bronchopulmonary dysplasia (BPD). BPD microscopically shows dilation of airspaces, airway (bronchial) epithelial hyperplasia and squamous metaplasia, alveolar wall thickening, and peribronchial as well as interstitial fibrosis. The major abnormality in BPD is a decrease in alveolar number, known as alveolar hypoplasia. 2. Necrotizing Enterocolitis (NEC) Most commonly occurs in premature infants, with the incidence of the disease being inversely proportional to the gestational age. It occurs in approximately 1 out of 10 very low birth weight infants (<1500 grams). Approximately 2500 cases occur annually in the United States. Clinically they may present with abdominal distention, absent bowel sounds, and bloody stools. Abdominal radiographs often show gas within the intestinal wall (pneumatosis intestinalis). The involved segment is either distended, friable, congested, gangrenous or may present as an intestinal perforation (free air) with accompanying peritonitis. Microscopically, mucosal or transmural coagulative necrosis, ulceration, bacterial colonization, and submucosal gas bubbles may be seen. 3. Intraventricular and Germinal Matrix Hemorrhage Subependymal (germinal matrix) hemorrhage, with secondary bleeding into the ventricles, is particularly prone to occur in preterm infants. Intracranial hemorrhages lead to sudden increases in intracranial pressure, damage to the brain substance, herniation of the medulla or base of the brain into the foramen magnum, and fatal depression of function of vital medullary centers.
2. Case with non-instantaneous absorption a. Kinetics of first order absorption and elimination: Cp is determined by both the absorption and elimination half-lives. Cp = kaFD/ Vd(ka-kel) * [e-kelt - e-kat]
TC refers to threshold concentration for drug effect. Note the potential impact of absorption rate and bioavailability on onset of effect and duration of effect and how that is dependent on the TC. b. The peak plasma concentration is dependent on the absorption and elimination half-lives, the volume of distribution, dose (D), and the fraction of dose absorbed (F, bioavailability); the faster the absorption, the higher the peak Cp and the earlier it occurs. In Figure 3 note the faster absorption rate for the drug in case A as compared to case C. c. Area under plasma concentration vs. time curve (AUC)* is dependent on dose (D), the fraction of the dose absorbed (F) and the total clearance ClT. AUC = FD/ClT The fraction of the dose absorbed into the systemic circulation (F) is the bioavailability of the drug product. Absolute bioavailability is determined experimentally by measuring the AUC of a dosage form of drug given by one route and comparing it to the AUC of the same dose of drug under conditions of complete absorption, i.e. given i.v. Absolute oral bioavailability is determined early in clinical studies of a drug that will be indicated for oral use. Relative bioavailability is determined by measuring the AUC of one dosage form of a drug (e.g., generic) and comparing it to the AUC of another dosage form of the same drug (e.g., proprietary) given by the same route and same total dose. Relative bioavailability of a generic drug must be equivalent to that of the proprietary drug for FDA approval. Bioavailability studies in human subjects are conducted with a cross-over design, in which on separate occasions each subject receives the drug by two routes (for determining absolute bioavailability) or the drug in the two formulations (for determining relative bioavailability). This design helps assure that ClT is about the same for the two arms of the study and thus minimizes its impact on the ratio of the AUCs. In Figure 3 note the greater relative bioavailability of drug in case A as compared to case B.
what determines equilibrium gradient? (where a drug wants to hangout @ equilibrium)
TISSUE FACTORS: 1. vascular permeability (e.g. BBB) 2. macromolecular binding in tissue (e.g. some drugs bind bone/muscle, etc.) 3. plasma protein binding (P+D<=> PD) 4. Dissolution of lipid-soluble drugs in adipose DRUG FACTORS: 1. MW 2. lipophilicity 3. affinity to carrier
high MW
TPA, mAbs don't diffuse across membrane, stays in plasma important for selective tissue uptake, can be saturated, can be rate dependant on expression of receptor endocytosis receptor-mediated: specific interaction of Fab with epitopes on cell-->can lead to targeting drug effects to a specific cell type SC or IM injection allows for more absorption than P.O route where mucosa acts as a barrier for high MW drugs. For high MW compounds, go into lymphatics and slow the absortion rate, excluded from BBB usually restricted to plasma (Vd=4% BW) RES of phagocytes in liver, spleen, LNs eliminates all biologics and endogenous IgG molecules fluid-phase: nonspecific driven by concentration of Ab, does not require ligand binding-->mAb enters into endothelial cells and peripheral tissues
4. Why might the relative potency of these drugs, and their selectivities, differ following oral administration in human subjects from those observed following in vitro administration?
The selectivity of these drugs in vivo could be affected by: their distribution to the target site and the extent of conversion to metabolites with affinity for adrenergic receptors. Their relative potencies could also be affected by differences in their oral bioavailabilities and their volumes of distribution.
Organochlorine Toxicity
VOC e.g. *PCBs* (polychlorinated biphenyls), dioxin (TCDD), lindane (DDT) source: old capacitors, incomplete waste incliner, pesticides toxic effects: - chloracne, rashes, liver damage, endocrine disrupter, probably carcinogens mech: - binding to aryl hydrocarbon receptor on cells --> transcriptional changes
Sections from the base of the papillary muscle at the point of rupture with advanced necrosis
What subcellular events are responsible for these morphologic changes? -Neutrophils produce free radicals and inflammatory mediators which result in additional tissue injury and release catalytic enzymes which digest necrotic tissue (heterolysis) Phospholipase from lysosomes releases free fatty acids from cell membranes which complex with calcium (saponification) and result in the bluish hue. If inflammatory cells do not reach necrotic tissue (e.g. dry gangrene) then necrotic cells mummify if their own proteolytic enzymes have been denatured and are not capable of autolysis.
VI. The excretion of chloramphenicol in the urine following i.v. as compared to oral administration suggests that:
a. Regardless of the route of administration, chloramphenicol is primarily eliminated from the body by a mechanism other than renal excretion Yes; since only 7.4% and 9.3% are recovered in the urine after p.o. and i.v. administration respectively, most of the dose of chloramphenicol must be eliminated by another mechanism. Return to Item VI to see if there is another correct answer. b. Chloramphenicol is incompletely absorbed from the intestine No; The total recovery of chloramphenicol in the urine, 0-24 hr after oral administration, is low, 7.4% of the dose. But this value is very similar to the cumulative urinary recovery after i.v. administration, 9.3% of the dose, indicative of nearly complete bioavailability. Reconsider the choices in Item VI. c. Chloramphenicol is incompletely absorbed and/or is eliminated by first-pass biotransformation in the liver No; the cumulative excretion of unchanged chloramphenicol after p.o. administration (67 mg/900 mg = 7.4% of dose) is similar to that after the i.v. route (77 mg/825 mg = 9.3% of dose). The bioavailability of chloramphenicol appears to be high. Your conclusion, based on cumulative urinary excretion data, agrees with your previous one based on AUCs of the serum data (see the comment to Item Vc), as you would expect. Since the renal excretion of chloramphenicol is so low, it would be preferable to have data on the urinary excretion of both unchanged drug AND any metabolites after p.o. and i.v. administration. Then you could estimate the fraction of the dose which is absorbed by dividing the cumulative excretion of drug AND metabolites after p.o. administration by the corresponding value after i.v. administration. Try Item VI again. d. Urine collected 6-24 hr. after i.v. administration of chloramphenicol would be expected to contain substantial amounts of unchanged drug No; generally the excretion rate of unchanged drug into urine is proportional to the plasma or serum concentration. You can see from the data that by 6 hours after i.v. administration the concentration of chloramphenicol in serum dropped to below measurable levels. Remember also that the elimination half-life is 1.1 hr in this animal. One half-life after an i.v. dose only 50% is remaining in the body, two half-lives only 25%, three half-lives only 12.5%, etc., so by 6 hours less than 3% is left. Of that 3% only a minor fraction is eliminated by the kidney, so you wouldn't expect to recover much in the urine after 6 hours. If you have considered choices 1-4 and found only one correct answer, you may now proceed to Item VII.
Lipopolysaccharide(LPS)
a. is found in the outer membrane of the cell wall of Gram-negative bacteria. b. is an endotoxin—an integral part of the cell wall which is released when the cell lyses and sometimes as membrane "blebs" (as opposed to exotoxins which are secreted from bacteria without cell lysis). LPS induces many disease symptoms caused by some Gram-negative bacteria by stimulating the release of TNF-alpha from macrophages, which in turn can lead to an excessive systemic inflammatory response and symptoms including fever, hypotension, disseminated intravascular coagulation (DIC), sepsis, and death. c. LPS composed of 3 units: i. Lipid A—a phospholipid responsible for the toxic effects. ii. A core polysaccharide of 5 sugars linked to lipid A. iii. An outer polysaccharide consisting of up to 25 repeating units of 3- 5 sugars; the somatic or O antigen of several Gram-negative bacteria used for clinical identification (Ex. O157:H7 E. coli) iv. The structure and endotoxic potential of LPS can vary among Gram-negative bacteria; e.g. some have shorter O-chains and are referred to as lipooligosaccharide (Neisseria meningitidis and N. gonorrhoeae); Lipid A in LPS of Fusobacterium is more potent than that of Bacteroides. Hey, since we won't have time in this course to talk much about Fusobacterium, you should do a quick Google search on it and read a little about it. d. LPS is recognized by PRRs and can activate the innate immune response.
overstimulation of sympathetic effects can cause fatal cardiac events
a1: vasoconstCictCon, ischemia in extremities, hypertensive reactions can cause cerebral hemorrhage, rebound nasal congestion; B1: tachycarida, myocardial ischemia, and arrythmias depending on pre-existing pathology, hyperglycemia; CNS activation in geCeral by unknown mechnismC
absolute risk, relative risk, absolute risk reduction, and number needed to treat
absolute risk = p relative risk = p1/p2 ARR = p1-p2 NNT = 1/ARR
toxicity of muscarinic antagonists
belladona alkaloids/ deadly nightshade poisoning (atropine, scopolamine) (inc. sympathetic b/c para blocked) - dry as bone - hot as pistol - red as beet - blind as bat - mad as hatter
where in the body is there transitional epithelial tissue?
bladder, ureters (transition between squamous and glandular)
TNF-alpha
cell signaling protein (cytokine) involved in systemic inflammation - one of the cytokines that makes up the acute phase reaction - produced chiefly by activated macrophages - produced by many other cell types such as CD4+ lymphocytes, NK cells, neutrophils, mast cells, eosinophils, and neurons
what are the cell-derived vasodilators? plasma protein derived?
cell-derived (preformed in granules): - vasoactive amines (Hist, 5HT) - COX products (=>arachidonic) - NO - PAF plasma protein derived: - bradykinin
why does our patient with infection experience fever and malaise ?
cyclooxygenase metabolites and cytokines; reset set-point and cause malaise
a2 receptor: 2nd messengers & effects
dec. cAMP pancreas: dec. insulin secretion nerve terminals: dec. NE release CNS: dec. sympathetic tone platelets: aggregation
ephedrine & pseudoephedrine
ephedrine = releases NE and directly activates alpha and beta receptors; orally less active, less CNS stimulation than amphetamine - controversial ingredient of many "nutritional supplements"; use restricted by FDA due to adverse effects pseudoephedrine = similar to ephedrine; widely used over-the-counter decongestant
radiopneumotitis
fibrosis of lungs due to ionizing radiation ionizing radiation can also cause: - vascular damage - inflammation - fibrosis
filtration rate is dependent on:
filtration = transport of small molecule drugs in bulk flow of aqueous fluid rate dependent on: - hydrostatic pressure - molecular weight, size, charge, and binding to excluded macromolecules - tissue porosity (e.g. glomerulus, BBB, liver sinusoids)
tyramine
indirect agonist (transmitter releaser / false transmitter) - present in foods, especially cheese, red wine, produced in small quantities by gut flora - normally degraded by MAO, but orally active when MAO is inhibited - can precipitate hypertensive crisis by releasing NE from nerve terminals - can be converted to octopamine and stored in synaptic vesicles replacing NE as "false transmitter" because it can be released, but has little effect on adrenergic receptors long term MAO inhibition can impair sympathetic NS function and make someone vulnerable to tyramine
Cocaine/tricyclic antidepressants prevents NE and dopamine reuptake
indirect agonist; reuptake inhibitors overstimulation of sympathetic effects can cause fatal cardiac events
cadmium mechanism & effect
indoor air pollutant increased ROS production? effect: obstructive lung disease, kidney damage, lung cancer (from occupational exposure)
quality control (QC)
making sure a test (whether automated, semi-automated, or manual) is generating correct or reasonably accurate results - instruments are prone to "drifting" - must do QC to calibrate - QC optimizes analytic phase of lab testing - can calibrate w/ products that manufacturers sell that have a known range for an acceptable result - qualitative tests have 2 ranges: positive and negative (e.g. malaria antigen test) - when QC has failed, you can't run any patient samples until troubleshooting has occurred and the repeat QC has passes - QC usually run at the beginning of every shift (3x/day); or before each run for low-volume or batched tests - Westgard rules are rules recommending re-evaluation of a test if QC results over time show too much departure from the mean, systemic bias, or too much variation (can analyze patterns over time to see if there's a bias in test)
Aspirin
nonselective NSAID; salicylates irreversibly inhibits COX-1 and COX-2 DO NOT USE ASPIRIN IN CHILDREN WITH VIRAL ILNESSNES, can cause REYES SYNDROME which is a fatal encephalopathy prophylactically to decrease risk of thromboembolic disorders (HA, stroke); tilts cycle in a cardioprotective direction by selective inhibition of thromboxane in the platelet can use dosage selectively: 81 mg/day has an antiplatelet effect; 650-1000 mg has an analgesic effect; 3g/day has an anti-inflammatory effect
phases of biotransformation
phase 1: oxidation, reduction, hydrolysis --> often introduces active site onto drug, which can be conjugated to be turned off phase 2: conjugation (results in usually inactive conjugated metabolite; usually more polar than parent compound) exception = morphine -- conjugated to become active (starts off w/ OH)
why is vascular leak beneficial? (exudate) (aka why do we have acute inflammation)
plasma proteins are important for: - killing invading pathogen - removing necrotic tissue need to let them get out of vasculature and into injured tissue
PAF
platelet activating factor phospholipid derived low levels: vasodilation high levels: vasoconstriction bronchoconstriction; leukocyte oxidative burst; leukocyte adhesion, chemotaxis, degranulation
drugs to induce mydriasis
pupil dilation radial muscle a1 agonist; epinephrine, phenylephrine
negative predictive value
the probability that a negative test result predicts that the patient doesn't have a disease NPV = TN / (TN + FN) - how many of the negative tests are actually negative?
propanolol treatment of hyperthyroidism Antagonist B1 & B2 (CNS penetrating)
treatment of cardiac arrythmias, reducing mortality after MI, maintaining cardiac output and tissue perfusion in shock, treatment of heart failure, treatment of hypertension, angina, stage fright, hyperthyroidism symptoms, migraine prophylaxis, glaucoma bronchoconstriction, bradycardia, exacerbation of angina, fatigue, cold extremities, potentiation of epinephrine vasoconstriction, precipitation of heart failure (if incorrectly used), new onset diabetes
therapeutic uses of a1 antagonists
(e.g. prazosin) - hypertension (not a first line therapy) - pheochromocytoma (to reduce a1 mediated hypertension from circulating adrenal medulla tumor agonists) - Raynaud's disease (reduce digital vasospasm) - heart failure (reduce TPR, easier on heart) - BPH (relieve difficulty in urination by decreasing bladder smooth muscle tone - a1 usually inc. it)
Morphine u/ agonist
(herion is semi-synthetic); not very lipohpillic (slow onsent and long duration); 76% ionized at pH polar-->entry/exit from CNS Is slow-->effects lag behind plasma concentrations medium (3-4 hours) hepatic: glucuronidation, demethylation (70% first pass) *can be used post-MI b/c of centrally mediated vasodilation, bradycardia (no effects on contractility, vascular response to catecholamines, sympathetic reflexes) morphine-6-glucuronide (metabolite) penetrates CNS poorly but can accumulate in the brain after chronic dosing rapid absorption, wide distribution, fast clearance; large first pass effect via hepatic metabolistm can displace histamine from mast cells and cause redness, hives, itching near injection site (but not an allergy). Facial itching and warmth are not a symptom of this (another mechanism)
effects of nicotine poisioning + how to treat
(ingested or transdermal nicotine) 1. rapid onset of abdominal pain, nausea, diarrhea 2. stimulated parasymp and symp NS 3. central stimulation can cause convulsion, coma, and resp arrest (gets through BBB into CNS) 4. skeletal muscle depolarization via receptor desensitization tx: - activated charcoal to dec. GI absorption - benzodiazepine to control seizures - iv fluids to maintain/inc. BP - atropine for bradycardia if needed (anti-muscarinic)
Clinical and lab presentation of Eosinophilic Granulomatosis with Polyangiitis
- First-aid says... - asthma, sinusitis, palpable purpura, peripheral neuropathy (wrist, foot drop), eosinophilia Purpura = red/purple raised spots on skin that don't blanch with pressure, usually due to vasculitis or scurvy - granulomatous vasculitis - P-ANCA positive (anti-neutrophil cytoplasmic antibodies) <-- present in a lot of inflammatory vasculites - Allergic granulomatosis and angiitis - Inflam of small and medium-sized arteries -- starts with asthma (95%) and allergic rhinitis -- pulmonary infiltrates and eosinophilia (>1500 eos) -- vasculitis of other organs - skin, GI tract, heart, nerves, kidney
Abatacept
- IgG1 like protein that binds to APC (antigen presenting cell) and *prevents T cell activation* - approved for RA - inc. risk of infection Mechanism: - inhibits binding of B7 (CD80/CD86) to CD28 and T cell activation (signal 2 of T cell activation) [ Remember - signal 1 = t cell rec binding to major histocompatability complex (MHC) on antigen presenting cell; signal 2 = a co-stimulatory ligand (B7) on APC binds to co-stim molecule (CD-28) on T cell ]
Some examples of large negative studies on supplement efficacy
- Saw Palmetto for BPH - Ginkgo for dementia - Echinacea for prevention/treatment of URI - St John's wort for major depression - glucosamine sulfate for osteoarthritis (Negative = proved supplement didn't work/wasn't better than placebo/maybe made things or other drugs worse)
particulate radiation
- alpha particles (2 protons, 2 neutrons - smoke alarms) - beta particles (electrons - paper & aluminum foil production) - neutrons (react w/ nuclei of other atoms --> new isotopes) radiation mechanism = DNA damage either directly or through production of ROS: dna damage can look different & result in different things, including cell death, fetus or germ cells (teratogenesis), and carcinogenesis
cystic fibrosis
- autosomal recessive - most common lethal genetic disease that affects caucasian populations - defect = abnormal function of CFTR on chromosome 7 - deletion of *deltaF508* (most common mutation among caucasians)
hematology lab tests
- blood counts, leukocyte differential (peripheral smear and body fluids), urinalysis (esp the microscopic component), routine coagulation, special coagulation, hemolysis, hemoglobinopathy, and flow cytometry tests
What things (endogenous and exogenous) trigger histamine release from mast cells and basophils?
- bradykinin - C3a and C5a - antigen interaction with IgE (hypersensitivity response) - basic drugs: curare, opioids, vancomycin (act directly on body to release histamine; NOT an allergy)
Herbal medicines and surgery
- certain herbal medicines may impact: Coagulation (ginkgo, ginseng, garlic) CV stability (ephedra) Glucose (ginseng) Anesthesia (valerian, kava) Inc. metabolism of perioperative meds: St. John's Wort - recommend avoiding for >= 2 weeks prior to surgery
conjugating moieties for biotransformation
- glucuronic acid - sulfate - methyl groups - glutathione - acetyl groups - glycine
toxicity of nondepolarizing skeletal muscle relaxant
- histamine release w/ tubocurarine and some related agents
receptor-mediated endocytosis
- importance in *selective* tissue uptake --> uses FAB region - rate dependent on receptor expression and membrane insertion - saturable kinestics - mechanism for some protein therapeutics (biologic agents e.g. mAbs) - same as clathrin-coated vesicle endocytosis
4 anti-inflammatory mechanisms of glucocorticoid
- inc. synthesis of phospholipase A2 inhibitor (lipocoortin) --> blocks arachidonic acid and its metabolites (first step of Arach. Acid inflammatory metabolite synthesis) - inc. synthesis of NF-kB inhibitor (ikB) - blocked transcriptional effects of NF-kB - dec. synthesis of adhesion factors that affect leukocyte localization Effect: *Block*--> - pain and vasodilation - enhanced vascular permeability and edema - extravasation of leukocytes - later stages: vascular prolif, fibroblast activation, fibrosis & Collagen production
How do depolarizing muscle blockers work?
- noncompetitively bind nicotinic ACh receptors (N agonist) - evokes receptor desensitization & VG channel inactivation - prolonged exposure to agonist --> N rec. get desensitized - rec. will gradually reset after agonist dissoc. - rapid onset & short duration (Recover within minutes of infusion termination) - rapidly hydrolyzed by *cholinesterase* in plasma - cholinesterase inhibitors *prolong* effect as they inc. endogenous ACh receptor activation e.g. succinylcholine
Adverse effects of long-term steroid use
- osteoporosis with fractures - muscle wasting - hypertension - hyperglycemia - candida infections - weight gain - infection - impaired wound healing - cataracts - behavioral disturbances (psychotic) - slowed growth in children (will catch up, but slower than age-matched peers)
where can the following be distributed: - high MW (e.g. protein drugs) - small MW and polar - small MW and lipophilic
- plasma only (Vd = 4% BW) - ECF (Vd = 17% BW) - >58% (> Vd (circulation + fat stores) --e.g. anaesthetics = lipophilic
Quality Assurance (QA)
- the systemic approach overseen by the pathologist/medical director and laboratory supervisor to improve lab function including pre-analytic, analytic, and post-analytic variables - many QA projects aim for improving TAT but also other things (labeling, minimizing corrected reports, minimizing contamination, etc.)
Adaptation, Injury & Cell Death
-Cells & Tissues Respond to Stress: cells need to adapt to stress via hyperplasia, hypertrophy, atrophy, or metaplasia. i.e. hyperplasia of liver via TNF on Kuppfer cell = IL-6 = EGF/TGF-a/HGF/MET = proliferation. -Prostate gland hyperplasia via testosterone -Hyperplasia (#/vol): • Increased number of cells • Increases volume of the organ or tissue. • Only in cell population capable of division. • Physiologic or Pathologic. -Hypertrophy: increased load response, mechanical stretch, agonist a-angiotensin, IGF-1, synthesis of proteins, GF, genes, more performance. -• Increase in the size of cells • Increased synthesis of cellular components. • Can occur in fully mature non-dividing cells. • Usually caused by increased functional demand. • Physiologic or Pathologic Denervation Atrophy, Autophagy, Myocardial residual bodies, disuse, denervation, ischemia, inadequate nutrition, loss of hormonal stimulation, senile atrophy. Atrophy: • Loss of cell substance and or cell number. • Protein degradation (ubiquitination) exceeds synthesis • Autophagic vacuoles increase • Residual bodies increase • Physiologic or Pathologic. Metaplasia: Barrett's Esophagus, reveriusble change, adult cell flip, induces cytokines and gf, tissue and circulating stem cell. 1) aerobic respiration for the production of ATP - the mitochondria 2) Osmotic and ionic balance - membranes 3) Protein synthesis - ribosomes 4) Structural maintenance and intracellular transport - cytoskeleton 5) Functional genetic apparatus - nucleus Injury via: 1. Oxygen Deprivation 2. Physical Agents 3. Chemical Agents and Drugs 4. Infectious Agents 5. Immunologic Reactions 6. Genetic Derangements 7. Nutritional Imbalances Reversible Injury: RER swelling, hydronic change, steatosis, clumping of chromatin, membrane blebs Irreversible: lysosome rupture, swollen mitochondria, cell membrane rupture -Threshold of effect is reversible then gets worse: Cell death, ultrasutrual changes late, light microscope changes later, gross chances latest -Acute Myocardial Infarct Coagulation Necrosis, Gangrenous Necrosis, Lung Abscess Liquefactive Necrosis, Liquefactive Necrosis of Brain Coagulative (pink) vs Liquefactive Necrosis (grainy) Enzymatic Fat Necrosis (grainy near fat) Tuberculosis of Lung Caseous Necrosis (giant cells) Fibrinoid Necrosis (central ring) Types: 1. Coagulative Necrosis - Gangrenous Necrosis 2. Liquefactive Necrosis 3. Enzymatic Fat Necrosis 4. Caseation Necrosis 5. Fibrinoid Necrosis Methods of Cell DeathL Low ATP, Mitochrondial leakage, Ca+ Entry leads to leaking mito, high ROS damage, Membrane damage (PM. or lysosome), protein misfoliding or DNA damage.
III. In the 16.5 kg dog the apparent volume of distribution (Vd) of chloramphenicol is:
. About 18 liters Correct, you have extrapolated the serum concentration to zero time after i.v. administration, 45 µg/ml (anti-ln of 3.8), and divided this number into the total dose, 825 mg, to determine Vd in liters, 18.3 l. Or you estimated the zero time level at about 48 µg/ml by realizing that the level is 24µg/ml at 1 hr after administration and because the half-life is about 1 hr, the zero time level would be two times higher. Now proceed to Item IV. No; The extrapolated zero-time value on your graph of ln Cp vs. time should be about 3.80. The anti-ln of this number is about 45 µg/ml. Or estimate the zero-time value as about 48 µg/ml, given a half-life of about 1 hr and a Cp value of about 24µg/ml at 1 hr. Now try again to calculate Vd. Go back to Item III.
Define metaplasia, dysplasia, anaplasia,and neoplasia
. Metaplasia - a reversible change from one adult cell type (epithelial or mesenchymal) to another adult type. Typically an adaptive response to chronic irritation. Example: squamous metaplasia of ciliated epithelial cells of the pulmonary bronchi secondary to cigarette smoke. While the metaplastic change is generally more "protective" it usually results in loss of function e.g. the loss of mucus production by bronchial epithelial cells. Metaplasia in and of itself is not a precancerous lesion. However the irritant that causes the metaplasia may in time lead to cancerous transformation Dysplasia: refers to a loss of normal orientation of one epithelial cell to the other and is accompanied by alterations in cell size and shape, nuclear size and shape, mitotic activity and staining characteristics. It is mostly encountered in lining epithelia and is generally graded as mild, moderate or severe. Some extend the term "dysplasia" to describe individual cells but strictly speaking dysplasia refers to the relationship of a group of cells making up a particular tissue. Dysplasia is a precancerous lesion. Milder forms of dysplasia are reversible. Anaplasia: refers to a lack of differentiation of cells and is marked by a number of morphologic changes including: cellular pleomorphism (variation in size and shape), nuclear pleomorphism, increased nuclear: cytoplasmic ratio (N/C ratio) abundant (abnormal) DNA content (aneuploidy) which stains dark (hyperchromatic) on H&E staining, presence of prominent nucleoli, increased mitotic (often atypical) activity and tumors giant cell formation. Generally associated with poorly differentiated malignancies.
The Rumack-Matthew nomogram was used to assess risk for developing hepatic necrosis
1) Is the level of acetaminophen sufficient to cause serious liver injury? 2) Doesthehistoryofalcoholconsumption contribute to the patient's risk? Ans: Enzyme inducers such as alcohol and phenobarbital can affect blood levels of toxic metabolites and affect outcomes: Substrate competition can occur when alcohol and acetaminophen are taken simultaneously and can result in prolonged half-life of CPY2E1. Longtime exposure to alcohol results in increased levels of the CYP2E1 isoform of cytochrome P-450 leading to increased levels of the toxic metabolite NAPQI
What laboratory tests should be ordered at this point? What is the rationale for the tests selected?
1)Transaminases,AST,ALT, 2)AlkalinePhosphatase,ALP 3) Bilirubin level, 4) Prothrombintime,PT 5)Bloodacetaminophenlevel, 6) Blood alcohol and toxin screen.
toxicity of depolarizing skeletal muscle relaxant
1. *malignant hyperthermia* (in pts w/ genetic skeletal muscle disorder featuring *excess Ca2+ release* in skeletal muscle --> body wastes a ton of heat trying to sequester Ca2+ back in - incidence = 1 in 4500-6000 surgical pts - tx = dantrolene (prevents Ca2+ release) 2. *prolonged action* of relaxant in pts w/ atypical plasma cholinesterase (can't hydrolyze the succinylcholine) 3. *hyperkalemia* => intracellular inc. K+ through nicotinic ACh channels - can be life threatening; worse in pts w/ denervating injury or disease, burns, or prolonged immobilization (b/c rec. is upreg) 4. *cardiac dysrhythmias* => stimulation of cardiac muscarinic rec. (usually bradycardia, although can have tachy esp. w/ high doses) 5. post-op muscle pain (mech unclear)
Mechanism of NSAID anti-inflam effct
1. Block COX (1 and 2, but 2 is the important one) Dec. production of prostaglandins Reduce inflam response 2. Inhibition of activation of NF-kB transcription factor --> dec. synthesis of pro inflammatory mediators such as TNF-a, dec. synthesis of COX-2 - inhibit NF-kB by blocking the dissociation of the "i" inactive unit
• Describe strategies for blocking B and T cell function with small MW drugs and large MW, monoclonal antibodies.
1. Calcineurin inhibitors a. Blocks T cell signaling for growth and differentiation by inhibiting enzymatic activity of calcineurin required for NFAT induction of T-cell IL2 synthesis, e.g., cyclosporine, tacrolimus b. Nephrotoxicity limits dosing, and drug interactions are also a problem. 2. mTOR inhibitors a. Blocks protein kinase (mTOR) activity required for cell cycle progression from G1 to S phase in T lymphocytes, e.g., sirolimus (rapamycin) 3. Antimetabolites a. Blocks purine or pyrimidine synthesis required for B and T cell replication, referred to as 'antimetabolites', e.g., methotrexate (inhibitor of tetrahydrofolate synthesis, drug of first choice in rheumatoid arthritis), azathioprine, mycophenolate 4. Alkylating agents a. Alkylates N7 residue on guanine to cause DNA inter-strand crosslinking that blocks DNA replication and cell division, e.g., cyclophosphamide (a "nitrogen mustard") 5. Biologics: Large, high MW proteins and monoclonal antibodies (mabs) a. TNF Antagonists: bind TNF and block its proinflammatory effects, e.g., etanercept (TNF receptor analogue), infliximab and others (mabs with high affinity for TNF) b. Costimulation modulator: IgG1-like protein that binds with high affinity to B7 on antigen-presenting cells (APC) and prevents T cell interaction with this APC site to block T cell activation, e.g. abatacept. c. Anti-integrin antibody: targets integrin-4 on leukocytes and prevents their egress into brain in multiple sclerosis or intestine in Crohn's disease, e.g., natalizumab d. IL-6 Antagonist: monoclonal antibody that binds the IL-6 receptor and blocks the proinflammatory effects of the cytokine IL-6, e.g. tocilizumab
Anatomic pathology primarily examines tissues and uses morphology / microscopy to diagnose disease, particularly cancers. Clinical pathology / laboratory medicine primarily examines body fluids such as blood, urine, cavity fluids, etc. and uses a variety of techniques in generating laboratory results. These laboratory techniques include chemical reactions, antibody based assays, automated cell count technology, morphology for cell and microbe identification, optical transmittance for coagulation assays, protein separation methods, molecular assays, etc. The clinician can use laboratory results in conjunction with the patient's history, physical exam, and radiographic findings to make a diagnosis, particularly non-neoplastic diseases. Hence both anatomic and clinical pathology are critical to the diagnosis of many diseases, from which treatment can be initiated.
1. Define sections of the clinical laboratory, and list some common lab tests in each section. 2. Classify the steps in using a laboratory test into pre-analytical, analytical, and post-analytical phases, and know where the clinician and pathologist may have impact on the process. 3. Describe accuracy, precision, reference range, and critical alert value in laboratory medicine. 4. Define sensitivity, specificity, positive predictive value, and negative predictive value of a lab test.
C. Excretion
1. Elimination of drug by excretion unchanged in body fluid or breath. 2. Routesofexcretion a. Urine: quantitatively most important excretory route for nonvolatile drugs and their metabolites; excretion rate depends on rate of glomerular filtration, proximal tubular active secretion and passive reabsorption; reabsorption is dependent on drug lipophilicity and urinary pH (raising the pH promotes excretion of acidic drugs, impairs excretion of basic drugs); drugs with fixed positive (quaternary ammonium compounds) or negative charge undergo minimal reabsorption. The mechanism of a drug's renal excretion can be inferred from its renal clearance *, the volume of plasma completely cleared of the drug per unit time; for a drug not bound to plasma protein a renal clearance greater than 120 ml/min in a 70-kg subject (GFR) indicates tubular secretion and less than that indicates net reabsorption. The renal clearance of a drug is determined experimentally by measuring a drug's excretion rate in the urine and normalizing it for the plasma concentration during the urine collection interval. ClR= urinary excretion rate/plasma concentration Sources of variation in renal clearance that may require modification of a dosage regimen include: 1) Age (low in neonate and progressive decline after about age 30 years) 2) Renal disease (correlation of drug renal clearance with creatinine clearance) 3) Plasmaproteinbinding(decreasedalbuminbindingincreases clearance by filtration) 4) Drug interactions (competition among co-administered drugs for transporters may reduce clearance by tubular secretion) b. Bile: quantitatively important excretory route for drugs and their metabolites that are transported by hepatocyte; once in small intestine compounds with sufficient lipophilicity are reabsorbed and cleared again by liver (enterohepatic circulation); more polar substances may be biotransformed by bacteria, e.g. hydrolysis of drug conjugates, and products reabsorbed; unabsorbed drugs and metabolites are excreted in feces. c. Minor routes: sweat, tears, reproductive fluids, milk; generally pH- dependent passive diffusion of lipophilic drugs; can be of toxicologic significance e.g. exposure of infants to drugs in milk.
C. Genotypic Classification The development of molecular techniques based on analysis of nucleic acids is changing the way bacterial classification and identification are done. The advantages of these techniques include their specificity (allows for definitive identification) and the ability to detect organisms that cannot be cultured. However, in some ways these can also be considered as disadvantages—why? Techniques include:
1. Guanine + cytosine content, i.e. the GC ratio in a genome or genome fragment. 2. DNAhybridization. 3. Nucleic acid sequence analysis. a. Ex. Amplification of ribosomal (16S) or other unique sequences by PCR. b. Ex. Pulsed field gel electrophoresis
4 Steps for Emigration of Leukocytes
1. margination (leukocytes move from middle of vessel to edges as dilation causes flow to slow down) 2. rolling along edge, via *selectins & integrins* (lower affinity) 3. tight adhesion w/ wall via *integrins* (higher affinity) 4. migration across vessel wall; result = accumulation of inflammatory cells
B. Transport Across Cell Membranes
1. Passive diffusion a. Passage through the lipid cell membrane by dissolution in membrane; rate dependent on concentration gradient and lipid:water partition coefficient of drug; rate markedly higher for unionized form of weak electrolyte because of its higher lipophilicity than the ionized form; obeys first-order kinetics (rate of transport is proportional to concentration gradient at transport site). b. Filtration through aqueous channels within membranes and between cells. 2. Activetransport a. Transport across a cell membrane facilitated by an energy-dependent membrane carrier mechanism such that transport can occur against a concentration gradient; transporters include the family of ATP-dependent proteins such as: the multidrug resistance p-glycoprotein (amphipathic, cationic and neutral substrates, 170 kD, mdr gene product, verapamil sensitive) the multidrug resistance-associated proteins (MRP1-6, 190 kD) and organic anion transporters (oatp); organic anion substrates, probenecid sensitive. b. Exhibits structural selectivity; one racemic form of a drug may be transported at a much higher rate than another; drugs may compete for binding to carrier and so one drug may inhibit transport of other drugs. c. Sites for drugs at choroid plexus (CSF to blood), cerebral vascular endothelium (brain to blood), proximal renal tubular cell (blood to urine), hepatocyte (blood to bile), tumor cells (efflux). d. Obeys Michaelis-Menten kinetics: if drug concentration is high enough to saturate carrier mechanism, kinetics are zero-order (rate of transport is constant). 3. Endocytosis a. Passage into cell within membrane invagination. b. Important mechanism for particulates, high molecular weight compounds such as protein therapeutics, and drugs with affinity for some membrane receptors.
2 types of macrophage activation
1. classically activated macrophage (M1) - activated by IFN-y, inhib by IL-13 and IL-4 - result = microbiocidal, inflammation 2. alternatively activated macrophage (M2) - activated by IL-13, IL-4, inhib by IFN-y - result = growth factors, TGFBeta for tissue repair & fibrosis ;; or IL-10 and TGF-B for anti-inflammatory effects SUMMARY: IFN-y -->M1--> inflammation, killing bacteria IL-13, IL-4 --> M2 --> tissue repair + anti-inflam
outcomes of acute inflammation
1. complete resolution 2. fibrosis (scar) :( 3. chronic inflam :(
Cytoplasm
1. contains the nucleoid and ribosomes, nutrient storage granules, metabolites and plasmids. a. Ribosomes i. Differ in size and composition from eukaryotic ribosomes— selective target of several antibiotics that inhibit bacterial, but not eukaryotic protein synthesis. b. Nutrient Storage Granules i. Several different types; stain characteristically and can be used to help identify some bacteria (e.g. glycogen, sulfur). c. Nucleoid i. The bacterial DNA chromosome (~2000 genes, no introns) ii. No nuclear membrane, no nucleolus, no mitotic spindle, no histones. d. Plasmids i. Extrachromosomal double-stranded, circular DNA molecules that can be transferred between bacteria and fungi, i.e. mobile genetic element. ii. Replicate independently of bacterial chromosome. iii. Found in Gram-positive and Gram-negative bacteria. iv. Often contain genes for antibiotic resistance, toxins, and other factors that contribute to virulence e. Transposons i. Another type of mobile genetic element, also called transposable elements or "jumping genes". ii. DNA sequence that can change move within a genome, but cannot replicate independently because it does not contain an ori of replication.
Outer Membrane of Gram-negative Cells
1. like a stiff "canvas sack" around the bacterial cell. 2. maintainscellstructure. 3. is a permeability barrier to large molecules (like lysozyme & vancomycin) and hydrophobic molecules; also provides protection from adverse environments like the GI tract; due in part to the long polysaccharide (hydrophilic) O-chains of the LPS molecules which extend out over the outer membrane. Mutants lacking these O-chains or with shorter O-chains, become sensitive to hydrophobic compounds, like bile salts and some antibiotics. 4. has an asymmetric bilayer structure: inner leaflet similar to other phospholipid membranes, but outer leaflet contains LPS. 5. containsagroupoftransmembraneproteins,porins,thatformporesallowing diffusion of small hydrophilic molecules. 6. is involved in signal transduction, e.g. quorum sensing: communication among bacteria. 7. can be disrupted by antibiotics, like polymyxin.
11-13 In two studies separated by two weeks, Drug Y was administered in a dose of 60 mg/kg to a 50-kg subject with a normal creatinine clearance. In the first study the drug was injected intravenously (IV), and in the second study it was given orally (PO). The plasma concentrations (Cp) were determined after each drug administration. 11. The plasma elimination half-life of Drug Y is approximately: A. Less than 2 hour. B. 2 hour. C. 4 hours. D. *6 hours. (use exact # if avail) E. 8 hours. 12. The volume of distribution of Drug Y suggests that its distribution: A. Is restricted to the vascular space. B. Includes extracellular but not intracellular fluid compartments. C. Excludes the central nervous system and adipose tissue. D. Is homogeneous and includes all fluid compartments in the body. E. Is substantially greater than total body water * Vd = Dose/Co Issues with calculating Vd mg/ mg/L LOW Vd: 6L (high drug in plasma) High Vd: 120L (low drug in plasma) 13. 3. These data suggest that Drug Y following oral administration: A. Has a bioavailability of greater than 50%. X B. Has a longer duration of action than after IV administration of the same dose. X C. Is completely absorbed within 2 hours. X D.* May be eliminated in feces or undergo a first-pass effect. E. Has a longer elimination half-life than after IV administration of the same dose. 14. Which of the following correctly characterizes the effect of continuous infusion of a drug at the same dosing rate in two patients with the same body weight and composition, but differing total clearances of the drug. The ClT in patient A is 500 ml/min and in patient B is 250 ml/min: A. *A steady-state plasma concentration would be achieved more quickly in patient A than B, and the level in patient A would be about half that in patient B. B. The steady-state plasma concentration would be higher in patient A than B. C. The steady-state plasma concentration would be the same in the two patients. D. Steady-state would occur at about the same time in the two patients. E. A steady-state would not occur in either patient, because continuous infusion of drugs cleared by first-order kinetics generally results in a continuous increase in plasma concentrations until the infusion is terminated. 16. A text indicates that a drug has the following pharmacokinetic parameters: ClT 10 ml/min/70 kg, Vd 20 l/70 kg, t1/2 23 hr, oral bioavailability 50%. You decide to prescribe this drug as once a day maintenance doses, given orally. Which of the following may best explain why after two days of therapy the patient has not achieved the therapeutic effect that you had intended: A. * Steady-state has not been achieved. B. The patient has a slower clearance of the drug than that of the population in general. X C. The bioavailability of the drug is greater than anticipated. X D. The patient has not complied with the prescription and taken one dose in the am and one in the pm. X E. The threshold plasma concentration of the drug in this patient is lower than in the population in general.
17. Which of the following is most likely to reduce the bioavailability of a drug from an orally administered solid dosage form: A. Rapid dissolution of the drug from the dosage form in the duodenal lumen B. * Oxidation by CYP450s in the intestinal mucosa and liver C. Affinity for a transporter that actively pumps the drug into the intestinal mucosa from the duodenal lumen. X D. Excipients that enhance disintegration of the dosage form in the gastrointestinal lumen. X E. Coadministration of another drug that blocks the acidic degradation of the drug in the gastric lumen. Oxidation by CYP450 reduces bioavailability of drug by decreasing half life and increasing clearance 19. Compared to oral administration of a drug in an aqueous solution, administration of the same dose of a drug in a controlled release oral dosage form is most likely to result in: A. A higher Cpmax and earlier tmax. B. A higher Cpmax and later tmax. C. A lower Cpmax and earlier tmax. D. A lower Cpmax and later tmax. * E. The same Cpmax and earlier tmax. 20. Chronic administration of propranolol results in an increase in the number of beta1-adrenergic receptors in the heart. In the figure above, if the dotted line indicates the effect of isoproterenol on the rate of beating of a normal heart in an organ bath, then which curve might most reasonably represent the effect of isoproterenol on a heart taken from an animal that had been treated for 3 months with propranolol? (You may assume that the heart was extensively washed such that no propranolol remains). A. a B. b C. c* same cpmax, early tmax since less time to build up receptors D. d E. e 22. A dog is injected with a moderate dose of epinephrine, and it is observed that the heart rate increases. After the heart rate returns to normal, the dog is pretreated with drug X, and then administered the same dose of epinephrine. This time, the heart rate slows down. Drug X might most reasonably be: A. A ganglionic blocker B. A muscarinic antagonist C. An alpha1-adrenergic antagonist D. A beta1-adrenergic agonist E. * A beta adrenergic antagonist 23. A young child is brought to the emergency room. The parents believe that she may have ingested something toxic. Her symptoms include tachycardia, dilated pupils, and flushed skin. She has a temperature of 103 °F. She might most reasonably have ingested which of the following: A. A muscarinic antagonist * blocks Ach/ParaSym B. Nicotine C. An acetylcholinesterase inhibitor D. Epinephrine E. An alpha1-adrenergic antagonist 24. A male, aged 62, is diagnosed with benign prostatic hyperplasia. Which of the following would be most likely to alleviate his primary symptom of difficulty in urination? A. Prazosin* B. Clonidine C. Propranolol D. Succinylcholine E. Metoprolol 24. A male, aged 62, is diagnosed with benign prostatic hyperplasia. Which of the following would be most likely to alleviate his primary symptom of difficulty in urination? A. Prazosin* a- Prazosin is in a class of medications called alpha-blockers. It works by relaxing the blood vessels so that blood can flow more easily through the body. Urinary retention medication and antihypertensive drug, B. Clonidine a+ Sedative and antihypertensive. This medication is used alone or with other medications to treat high blood pressure (hypertension). Lowering high blood pressure helps prevent strokes, heart attacks, and kidney problems. Clonidine belongs to a class of drugs (central alpha agonists) that act in the brain to lower blood pressure. C. Propranolol b1/b2 Nonselective Beta blocker It can treat high blood pressure, chest pain (angina), and uneven heartbeat (atrial fibrillation). It can also treat tremors and proliferating infantile hemangioma. In addition, it can prevent migraine headaches. D. Succinylcholine Ach+ Cholingergic Succinylcholine is a depolarizing skeletal muscle relaxant. As does acetylcholine, it combines with the cholinergic receptors of the motor end plate to produce depolarization. ... The mechanism of action of Succinylcholine involves what appears to be a "persistent" depolarization of the neuromuscular junction. E. Metoprolol b1 Lopressor is a beta1-selective (cardioselective) adrenergic receptor blocker. This preferential effect is not absolute, however, and at higher plasma concentrations, Lopressor also inhibits beta2- adrenoreceptors, chiefly located in the bronchial and vascular musculature. 25. A patient with amyotrophic lateral sclerosis (a motor neuron disease that produces functional denervation of skeletal muscle) would be expected to be at greater risk for what adverse side-effect of succinylcholine, when succinylcholine is used as a surgical muscle relaxant? A. Desensitization B. Histamine release C. Bronchoconstriction D. Hyperkalemia* (depolarize more = Na in K out) E. Skeletal muscle paralysis 26. After mistakenly eating a mushroom containing muscarine, a patient presents with symptoms including hypotension. Normal blood pressure is restored by an injection of phenylephrine. This is an example of A. Chemical antagonism Chemical antagonism occurs when a drug reduces the concentration of an agonist by forming a chemical complex B. *Physiological antagonism Physiological antagonism describes the behavior of a substance that produces effects counteracting those of another substance C. Pharmacological antagonism: NA D. Pharmacokinetic antagonism: NA E. Synergism the interaction or cooperation of two+ 27. Which of the following would be most likely to produce an adverse effect in a patient with glaucoma A. Carbamylcholine Ag Nicotinic + Musc B. Neostigmine Ach Inhib C. Propranolol nonselective b1 D. * Atropine Musc. antag. In cardiac uses, it works as a nonselective muscarinic acetylcholinergic antagonist, increasing firing of the sinoatrial node (SA) and conduction through the atrioventricular node (AV) of the heart, opposes the actions of the vagus nerve, blocks acetylcholine receptor sites, and decreases bronchial secretions. E. Clonidine It is used to lower high blood pressure. Clonidine works by stimulating alpha receptors in the brain. This action reduces the nerve signals that are sent from the brain to the blood vessels causing them to contract and narrow. As a result, the blood vessels are allowed to relax and widen
Benefits of Soy
1995 meta-analysis + >40 studies after show soy protein 25g/day reduces total cholesterol 9%, LDL 13&, TGs 11%
F. MetabolismofGlucose 1. Glycolysis is the process by which glucose is converted to pyruvic acid, and it serves as the first step in a variety of aerobic and anaerobic reactions producing energy for the cell.
2. Fermentation is the process by which pyruvic acid, produced during glycolysis, is converted to energy (ATP). It is the process by which facultative bacteria produce ATP under anaerobic conditions. 3. Under aerobic conditions, pyruvic acid enters the Krebs cycle (also referred to as the oxidation cycle or tricarboxylic acid, TCA, cycle) and is metabolized to CO2 and H2O. 4. The Krebs cycle generates much more ATP than fermentation, so facultative bacteria grow faster under aerobic conditions. 5. Both facultative and anaerobic bacteria ferment, but obligate aerobes do not. 6. Fermentation tests in the clinical laboratory are used to identify certain bacteria. The fermentation of sugars results in production of ATP and pyruvic or lactic acids. The acids lower the pH of the medium which is detected by a change in color of indicator dyes.
Predict the impact of a dose increase on the duration of drug effect, and explain the pharmacokinetic and pharmaco- dynamic conditions under which that prediction is valid.
2. Multiple dosing kinetics a. Commonly, drugs are administered repeatedly in order to maintain their therapeutic effects. In the simplest case, a maintenance dose (D) is given at a constant dosing interval (). Since the route of administration may not be i.v., the amount of drug which reaches the systemic circulation may be some fraction (F) of the dose. If elimination is by first-order kinetics, a steady-state is eventually reached. The "average" Css at steady-state is the fraction absorbed times the dosing rate divided by total clearance, analogous to the Css from an infusion (see above). CSS "average" = F D/t / ClT b. However, unlike an infusion, in the case of repetitive dosing, drug plasma concentrations fluctuate during the dosing interval, depending on the kinetics of absorption and elimination. The degree of fluctuation in the plasma concentration during a dosing interval increases with increasing dose, dosing interval, clearance, and absorption rate. c. If a drug is administered i.v. (or where absorption is rapid and complete), the peak plasma concentration at steady-state (Cmaxss) relative to the peak after the first dose (C0) depends on the ratio of the dosing interval and the elimination half-life ( t / t1/2 ). The more frequently a drug is given, relative to its half-life, the more drug that remains at the end of each dosing interval, and the higher the levels will be at steady-state, relative to those after the first dose. Cmaxss = C0 / 1-f where f is the fraction of drug remaining at the end of a dosing interval (t). f = e -kel*t = e (-0.693/t1/2) t = 0.5 t/t1/2 So the more frequently a drug is administered relative to its half-life, the more it accumulates and the greater the steady-state level relative to the level after the first dose. If a drug is administered at a dosing interval about equal to its half-life, then the accumulation is two-fold. If a drug is administered at a dosing interval about seven times its half-life, almost all drug is eliminated after each dose, and there will be no accumulation. Each time that the maintenance dose D is administered, the plasma concentration increases from Cmin to Cmax. CminSS + D/Vd = CmaxSS D/Vd =C0 CminSS + C0 = Cmax SS The decline from Cmax to Cmin is governed by the t1/2, just as in single dosing. CminSS = CmaxSS e^ -kelt d. Prediction of Cmax and Cmin at steady-state can be of great importance in cases where therapeutic efficacy is to be maintained while minimizing the risk of toxic side effects. (Note that the CSS "average" described above lies between CmaxSS and CminSS, but is not mathematically equivalent to their arithmetic or geometric mean.) The therapeutic window in a dosing regimen is the range of efficacious, non-toxic plasma concentrations lying between CmaxSS and CminSS. If these are known, then the dosing regimen is determined as follows: Maintenance dose = (CmaxSS - CminSS) ( Vd ) Dosing interval (t) = [ ln CmaxSS /CminSS ] [ t 1/2/0.693 ] Typically, a guide to the appropriate dosing regimen for a given therapeutic agent is provided on the basis of a clinical trial. The physician must then consider whether that regimen must be modified in an individual patient due to pharmacokinetic factors, such as differences in the patient's volume of distribution and total clearance of the drug from the population mean values. In addition, for some drugs, plasma levels are monitored and then the physician must interpret the reported values to help determine whether the regimen should be modified. e. The rate of achieving steady-state is determined by the elimination half-life (as with an infusion). A loading dose may be used to rapidly achieve steady-state concentrations; use of a loading dose is especially important for drugs with long half-lives since attainment of steady-state is slow. This is especially the case when an immediate therapeutic effect is desired. Loading dose = ( CmaxSS ) ( Vd )
1. describe the major differences between eukaryotic and prokaryotic cells and explain why it is important to know the differences.
2. usebacterialnomenclatureproperly. 3. describe the phenotypic features used to classify bacteria, including cell morphology and arrangement, colonial morphology, and hemolysis. 4. explain the difference between phenotypic and genotypic classification of bacteria and the advantages and limitations of each. 5. describe how the Gram stain is done, what a Gram-negative vs. Gram-positive cell looks like microscopically, and how the Gram stain is used in clinical medicine. 6. explainthedifferencebetweenpresumptivevs.definitiveidentificationofbacteriaand lab tests used for each. 7. list the major structural features of bacteria and their functions in the bacterial cell and in disease production. 8. describe the major structural differences between Gram-negative cells and Gram- positive cells. 9. explain why some bacteria cannot be Gram-stained and why it is important to know which bacteria cannot be Gram-stained with respect to ordering and interpreting lab diagnostic tests. 10.diagram the basic structure of peptidoglycan and explain how lysozyme disrupts this structure. 11.describe the basic structure of LPS, its role in disease production, and how it is used in identifying certain bacteria. 12.compare and contrast teichoic acid and LPS with respect to which bacteria contain these structures and their roles in pathogenesis. 13.describe the cellular location and functions of capsules, flagella, and pili (fimbriae), and their roles in disease production. 14.explain what spores are and describe the properties of spores that promote disease production and affect methods used for sterilization.
Using the data in the Table 1 above, which of the following best describes the appropriate measure of association between salicylates and Reye's syndrome? Refer to the Stat-Ref tool if you need help with the analysis.
26/1 / 53/87 Odds Ratio=42.7
H1 receptor 2nd messenger + antagonists
2nd messenger = IP3/DAG-->Ca2+ Diphenhydramine Loratidine
2. After bacteria have colonized and multiplied, usually at the site of entry, invasion (of cells and/or tissues) and spread to other parts of the body may occur. There are numerous virulence factors that enhance invasion and often contribute to tissue damage. a. Ex. Collagenase and Hyaluronidase i. degrade collagen and hyaluronic acid, respectively. ii. facilitate spread (invasion) of bacteria through subcutaneous tissue. b. Ex. Lecithinase (phospholipase): damages host cell membranes c. Ex. Streptokinase (fibrinolysin): activates enzyme in plasma that dissolves coagulated plasma; may facilitate spread of bacteria.
3. Some bacteria can grow intracellularly. a. They may be obligate or facultative intracellular bacteria and grow in different cell types, including macrophages. b. Some bacteria invade cells via specialized surface proteins that bind to specific cellular receptors. i. Ex. Type III secretion systems to "inject" factors into the host cell that promote uptake of bacteria and intracellular survival or replication. c. Intracellular growth protects organisms from extracellular host defense mechanisms, and provides access to intracellular nutrients. 4. Some bacteria may grow in biofilms which provide protection from the immune response and antimicrobials; nearly impossible to treat, once formed. 5. Some bacteria produce siderophores, iron-binding factors that allow them to compete with the host for iron bound to hemoglobin, transferrin, and lactoferrin.
1. Which of the following is most likely to increase the absorption rate of a basic drug, when it is administered orally in aqueous solution: A. Administration with a large meal rather than a glass of water. B.* An increase in stomach emptying rate. C. An increase in the first pass effect. D. A decrease in gastric blood flow. E. An increase in gastric acid secretion rate. 2. Which of the following correctly pairs certain drugs with a patient attribute that is likely to lengthen the plasma elimination half-life and the duration of drug effect from the average in a population: A.* Drugs cleared by CYP3A4: a gene mutation that decreases CYP3A4 activity. B. Drugs cleared by some cytochrome P450 enzymes: chronic smoking. C. Prodrugs: high renal clearance of the prodrug. D. Drugs cleared by hepatic CYP3A4: renal impairment. E. Morphine and chloramphenicol: inactivating mutations in CYP2D6 gene. 3. If the absolute bioavailability of an oral 10 mg dose of a proprietary formulation of Drug X is 30%, then a generic version marketed after patent expiration: A. Must have an absolute bioavailability of 80-100%. B. Must have an AUC of Cp vs t after oral administration that is 30% of the oral 10 mg proprietary formulation. C. Must result in 30% of the dose excreted in the urine. D.* Must contain 10 mg of Drug X and have comparable bioavailability to be labeled as bioequivalent. E. Must result in 70% of the dose excreted in the feces. 4. If the decline in the plasma concentrations of a drug after intravenous injection is monoexponential, then it is reasonable to conclude that: A. The drug is cleared according to zero-order kinetics. B. The drug does not distribute instantaneously into its volume of distribution and accumulates extensively in fat. C.* The drug rapidly equilibrates into its volume of distribution and is eliminated by first order kinetics. D. The drug is eliminated at a constant rate due to enzyme saturation. E. The elimination half-life of the drug will depend on the dose. 5. In administering a drug cleared by a phase II biotransformation reaction, you should consider that: A.* A genetic polymorphism may affect the nonrenal clearance of the drug. B. Renal impairment, with an increase in serum creatinine, is likely to increase clearance of the drug conjugate. C. The drug conjugate is likely to have the same Vd and elimination half-life as the parent drug. D. The drug conjugate is likely to have the same efficacy as the parent drug. E. The parent drug is likely to be a prodrug
6.Which of the following correctly pairs a description of a drug and a mechanism that will increase its renal clearance (ClR): a. *Acid of pKa4, 95% bound to albumin: displacement from albumin. b. Base of pKa8: increased urinary pH. c. Quaternary ammonium compound: decreased urinary pH. d. Substrate for transport carrier in proximal tubule: coadministration of a second drug with affinity for the same carrier. 7. Drug cleared by CPY450: coadministration of a CYP450 inducer. A protein therapeutic with a molecular weight of about 70,000 D is likely to: a. Be cleared by glomerular filtration with a ClR of 120 ml/min/70 kg. b. Be a substrate for the organic anionic transporter protein (oatp) in the renal proximal tubule. c. Cross the cerebral vascular endothelium by passive diffusion and reach a concentration in the cerebral extracellular fluid equal to the plasma. d. *Have a small Vd of about 4% of body weight. d. Have a short absorption half-life after s.c. injection. 8. Which of the following factors is most likely to explain the difference observed in the figure above between subjects in Group 1 and 2 after iv injection of 1 mg/kg of Drug M: A. Group 1 has a much higher body mass index than Group 2. B. Group 2 are pretreated with an inducer of the CYP450 that biotransforms the drug. C. Group 2 has renal impairment, and the drug is cleared primarily by CYP2D6. D. Group 1 is coadministered with an inhibitor of CYP3A4, the isozyme that biotransforms the drug. E.* Group 2 are neonates and the drug is cleared by glucuronyl transferase. because rest are phase II and this is an IV infusion 9. After continuous intravenous infusion, the desired therapeutic effect is achieved with about the same steady-state plasma concentrations for Drug A and for Drug B. The two drugs are chemically similar with about the same Vd. However, Drug A has a much longer half-life. How should the dosing regimens differ to achieve comparable effect? A. The infusion rate should be higher for Drug A. B. The infusion rate should be the same for the two drugs, and a loading dose may be more appropriate for Drug B. C. The infusion rate should be the same for the two drugs, and a loading dose may be more appropriate for Drug A. D.* The infusion rate should be lower for Drug A, and a loading dose may be more appropriate for Drug A than Drug B. E. The infusion rate should be lower for Drug B, and a loading dose may be more appropriate for Drug B than Drug A. 10. A drug with an elimination half-life of 8 hours is administered by intravenous injection of 10 mg every 8 hours. At steady state, approximately how much drug will be in the body at the end of the dosing interval (the trough or minimum), just before the next injection: A. 5 mg B.* 10 mg C. 20 mg D. 40 mg E. 80 mg Steady state: 10mg + 10mg /2 = 10mg
6. Reimbursement Issues 6.1 Impact of Insurance - 6.1.1 Most pharmacy payments are made by third parties (insurers) to the pharmacy using various complex reimbursement formulas 6.1.2 Insurers negotiate prices with pharmaceutical manufacturers and negotiate payment rates with pharmacies
7. Managing Drug Expense 7.1 Formulary System - List of drugs and attendant policies and procedures intended to promote optimal quality of the medication use process (prescribing, dispensing, administration, and monitoring of drug therapy) 7.2 Generic Equivalence - same drug, different manufacturers; Therapeutic Equivalence - different drugs, same intended therapeutic effect 7.3. Treatment/Management Protocols 7.3.1 Clinical Practice Guidelines - broad statements that incorporate available evidence on health outcomes into sets of recommendations concerning appropriate management strategies for patients with specific conditions 7.3.1.1 Drug Use Guidelines - standards for optimal use of a particular drug or class of drugs 7.3.2 Disease State or Care Management - a comprehensive, integrated approach to care and reimbursement based on the natural course of a disease, with treatment designed to address an illness with a maximum effectiveness and efficiency
t_1/2 =
= 0.693 * (Vd/ClT) = 0.693 / Kel
• To list the 2 main categories of drug induced liver injury and examples of drugs and chemicals that are linked to each category • To correlate abnormalities of liver function tests with progression of hepatotoxic injury • To explain the molecular basis for acetaminophen toxicity to the liver and the factors that affect the extent of liver injury • To describe the pathologic findings in the liver in patients with hepatoxic and drug hypersensitivity liver injury.
A 23 year old female came to the ER at BMC, agitated and complaining of nausea and right upper abdominal discomfort. She reported that she had ingested about 30 acetaminophen (Tylenol) tablets (500 mg each) 12 hours earlier. She had been depressed for several weeks and admitted that her intention was to commit suicide. She was not on anti-depressant medications. She had been drinking more than usual over several months and had four or five shots of vodka in the hours before taking the Tylenol overdose. •On physical exam she appeared anxious, pale and sweaty. •BP 126/67 mm Hg; pulse 98 bpm; respirations 22/min; temp.98.6 F (37 C) •The remainder of the physical exam was unremarkable
Are You Putting Your Patient at Risk of Developing Renal Failure? A study was carried out to assess whether end-stage renal disease (ESRD) was associated with use of analgesic agents. [Sandler et al: Analgesic use and chronic renal failure. N. Engl. J. Med. 1989;320:1238-43.] Subjects with renal disease (defined as serum creatinine >130 μm/l [1.5 mg/dl]) were identified from hospital discharge summaries using ICD-9 codes; trained reviewers examined their medical records to identify newly diagnosed cases of renal disease. Subjects were excluded if they had systemic conditions or family syndromes associated with renal disease. In all they identified 709 patients with newly diagnosed primary renal disease. The comparison group was obtained by random-digit dialing and from lists of Social Security recipients. The comparison group was matched to the group with renal disease by age (within 5 years), race, and gender. The two groups were sent letters explaining the study, and they were then contacted for a telephone interview. 607 patients were successfully contacted by phone, and 554 agreed to be interviewed. In the comparison group 608 individuals were successfully contacted, but 4 indicated a history of renal disease; of the remaining 604, 516 consented to be interviewed. Interviews obtained information about past use of medications, life style, and occupational and environmental exposures. Not all subjects could answer questions for themselves. Information was obtained by proxy interviews for 55% of the renal patients and 10% of the comparison group.What type of study was this?
A case-control study This is another example of a case-control study in which participants were selected for each group based on their outcome. Cases with renal disease were compared to controls without renal disease regarding prior exposures, including use of analgesics.
Mechanism of cyclophosphamide
A nitrogen mustard (bis(chloroethyl)amine) - alkylates N7 guanine in DNA (cross-link)--> inhibits DNA replication - must be activated to 4-hydroxy-cyclophosphamide by liver cytochrome P450 - wide utility: leukemia/lymphoma, breast, ovarian cancer - used in rheumatologist disorders to suppress immune system - side effects: nausea, vomiting, bone marrow suppression, sterility, hemorrhagic cystitis
I. Growth Cycle
A. Bacteria reproduce by binary fission: one cell divides to form 2 progeny cells. This results in exponential (logarithmic) growth. 1. Number of cells 1 2 4 8 16 Exponential 20 21 22 23 24 One bacterial cell produces 16 cells after just 4 generations....yikes! 2. Some bacteria, like E. coli, which can cause diarrhea, have a generation time of 20 minutes....a short generation time + exponential growth = big trouble. 3. Some bacteria, like Mycobacterium tuberculosis, have a longer generation time; this can also cause big trouble, but it takes longer. 4. Bacteriacangrowinavarietyofformsinthelaboratory(andinthehumanbody): a. as colonies on a solid nutrient medium. b. in a broth culture in suspension. c. in biofilms in which growth is spread over an inert surface and nutrients are obtained from a fluid that bathes the surface.
III. Biosynthesis
A. Bacterial metabolism results in products that are used for the synthesis of cellular constituents, like peptidoglycan, LPS, proteins, nucleic acids, etc. You learned about the mechanisms of bacterial transcription of mRNA, DNA replication (including types of mutations that can occur), and translation of proteins in biochemistry lectures. B. Since bacteria do not have a nuclear membrane, transcription and translation are coupled. C. The bacterial cytoplasmic membrane is the site for many of the functions carried out by specialized eukaryotic organelles, including electron transport and energy production. D. Synthesis of peptidoglycan occurs in 3 phases, each of which can be inhibited by various antibiotics: 1. Precursorsubunitsaresynthesizedandassembledinsidethecell a. the antibiotics, fosfomycin and cycloserine, inhibit precursor synthesis in the cytoplasm. 2. At the membrane the units are attached to the bactoprenol "conveyer belt". 3. The bactoprenol molecule translocates the subunits to the outside of the cell, where they are attached to the polysaccharide chain. Crosslinking of the tetrapeptide chains between the NAM-NAG glycan chains of peptidoglycan is catalyzed by enzymes called transpeptidases. These enzymes are also called penicillin-binding proteins (PBP) because they are the target of β-lactam antibiotics, such as penicillin, which bind to them. Transpeptidases are bound to the cell membrane of Gram-positive and Gram-negative bacterial cells. a. The antibiotic, vancomycin also inhibits the transpeptidation crosslinking reaction using a different mechanism than β-lactam antibiotics. b. Bactoprenol is normally recycled; the antibiotic, bacitracin, inhibits the re-use of bactoprenol. E. Teichoic acid is synthesized from precursors in a similar manner as peptidoglycan. F. Lipopolysaccharide (LPS) Synthesis 1. Lipid A and core portions are enzymatically synthesized at the inside surface of the cytoplasmic membrane. 2. RepeatingunitsoftheOantigenareassembledonabactoprenolmoleculeand transferred to a growing O antigen chain. 3. The completed O antigen chain is transferred to the core lipid A structure. 4. The LPS molecule is then translocated through adhesion sites to the outer surface of the outer membrane.
II. THE PHARMACOKINETICS OF INFUSIONS AND MULTIPLE DOSING
A. CONTINUOUS INFUSION OF PENICILLIN G 1. Comparison of the total and renal clearance values for penicillin G indicates that renal clearance is the primary elimination mechanism. The renal clearance greatly exceeds GFR, indicative of clearance by tubular secretion. Other drugs cleared by the renal organic anionic transporter protein (oatp) may compete with penicillin and reduce its renal clearance. The clearance may also be reduced by reduction in renal plasma flow or diseases of the renal tubules. 2a. Css = 0.1 ug/ml ClT = 700 ml/min ko = Css ClT = 0.1 ug/ml 700 ml/min = 70 ug/min 19-11 2b. 50% of SS is achieved in one elimination half-life, 30 min; 93% in four half-lives, 120 min 2c. Loading Dose = Css VD = 0.1 ug/ml 0.42 l/kg = 0.1 mg/l 0.42 l/kg = 0.042 mg/kg = 2.94 mg/70 kg The loading dose does not affect the Cpss achieved by the infusion. 2d. Once the infusion is terminated, it takes two elimination half-lives, 60 minutes, for Cp to drop from the Css of 0.1 ug/ml to 0.025 ug/ml. 3a. To achieve the same Css if renal disease has caused a 50% drop in ClT, reduce ko by 50%. 0.50 (70 ug/min) = 35 ug/min 3b. The elimination half-life is doubled by the 50% reduction in ClT, and so it will take twice as long to reach any specific fraction of ss. 3c. The appropriate loading dose is not affected by the renal disease, unless the VD or the MIC has changed.
II. DrugAbsorption
A. Definition and Characterization 1. Absorption refers to the process by which drug molecules leave the site of administration and gain access to the systemic circulation (plasma). The process is characterized by its rate (or absorption half-life) and the percent of the dose that reaches the circulation in the same molecular form as it was administered (bioavailability*). 2. Bioavailability is primarily dependent on the extent to which a drug can i) move through the cell layers between a site of administration and the plasma and ii) not be converted along the way into another molecular form. B. Routes of Drug Administration 1. General determinants of absorption rate a. The factors that may affect the absorption rate of a drug include: dissolution into aqueous fluids at absorption site from a solid formulation, lipid solubility, concentration gradient, blood flow at absorption site, surface area of absorption site. b. If multiple processes are involved in the absorption of a drug, such as first dissolution from a solid formulation and then passive diffusion across the intestinal epithelium, then the slowest process will be the rate-limiting one that primarily determines the absorption rate. 2. ParenteralInjection a. Intravenous (i.v.) Injection: complete bioavailability; drugs given in sterile aqueous solution, except for few cases of lipid emulsion; important when immediate effect required; increased risk of toxicity. b. Subcutaneous (s.c.) and Intramuscular (i.m.) Administration: more extensive absorption of high molecular weight, polar molecules than by p.o. route; absorption rate can be manipulated by formulation, e.g. rapid from aqueous solution, slow from suspension or solid pellet. 3. PulmonaryInhalation a. Rapid absorption of drugs in gaseous, vaporized or aerosol form. b. Absorption of particulates depends on particle size which influences depth of entry in pulmonary tree. 4. TopicalApplication a. Usually for local effect b. Absorption through mucous membrane may be rapid c. Absorption through skin generally slow; enhanced by increased lipophilicity, by damage to stratum corneum, and by increased local blood flow. 5. Oral (p.o.) Ingestion a. Convenient route for administration of solid as well as liquid formulations. b. Additional variables that may influence rate and extent of absorption include disintegration and dissolution of solids, acidity of gastric contents, gastric emptying rate, intraluminal biotransformation by host or bacterial enzymes, dietary contents, and presence of other drugs. c. First-pass effect: absorbed drug passes via portal circulation through liver that may clear substantial fraction and thus decrease the bioavailability (percent of dose which reaches the systemic circulation); enzymes in GI lumen and mucosa may also clear drug and contribute to first-pass effect.
Clonidine Adrenergic Agonist
Agonist a2 selective (crosses BBB) a2: anti-hypertensive, not a first line therapy (total sympathetic block in CNS, can cause sedation) a2: treatment of opoid withdrawal *causes its own withdrawal symptoms, reversal of hemodynamic effects like hypertension and tachycarida
Atropine Belladona (Atropa belladonna) Codeine Poppy (Papaver somniferum) Colchicine Autumn crocus (Colchicum autumnale) Digoxin Foxglove (Digitalis purpurea) Ephedrine Ephedra (Ephedra sinica) Reserpine Rauwolfia (Rauvolfia serpentine) Salicylic acid Willow bark (Salix purpurea) Scopolamine Jimson weed (Datura stramonium) Taxol Pacific yew (Taxus brevifolia) Vincristine Madagascar periwinkle (Catharanthus roseus)
Alfalfa Hypoglycemic, manganese, human Aloes/Aloe vera Hypoglycemic, in vivo Burdock Hypoglycemic, in vivo Celery Hypoglycemic, in vivo Cornsilk Hypoglycemic, in vivo Damiana Hypoglycemic Elecampane Hypoglycemic Eucalyptus Hypoglycemic, in vivo Fenugreek Hypoglycemic, human Garlic Hypoglycemic, in vivo, human Ginger Hypoglycemic, in vivo Ginseng, Panax Hypoglycemic Juniper Hypoglycemic, in vivo Marshmallow Hypoglycemic Myrrh Hypoglycemic Nettle Hypoglycemic Sage Hypoglycemic, in vivo Tansy Hypoglycemic, in vivo
The table below summarizes results of the adverse outcomes in the Physicians Health Study. Use the Cohort Studies worksheet in "Stat Tools" Excel spreadsheet to compute the relative risk and p-value for the association between aspirin use and fatal myocardial infarction.
Aspirin was associated with a significantly reduced risk of fatal and non-fatal myocardial infarctions, (see relative risks for below) but aspirin users had significantly more bleeding ulcers and other bleeding problems and a borderline significant increase in hemorrhagic strokes. These results were controversial at the time. Most of the investigators wanted to continue the study to clarify whether there was an increased risk of stroke. However, the data safety and monitoring board for the study strongly recommended that the study be terminated, because the benefit of aspirin had been clearly demonstrated, and they felt it was unethical to withhold its use from half of the participants. Another useful way to weigh benefits and risks is to compare risk differences (attributable risks). This gives a useful perspective on the actual numbers of people who might benefit or be placed at risk by a treatment. Table 5 below looks at the same data that was presented in the previous table, but from the perspective of risk difference.
Factors to Consider When Bringing on or Replacing a Test
Automation: Ideally a more automated test allows for greater ease, improved efficiency, and minimization of human errors. There is a greater need for more automated tests as laboratories perform a greater number of tests to meet clinician needs. As a result manufacturers are competing with each other in creating the most automated instruments. Accuracy: Measures how close a method is in providing a test value that is close to the "true" value. The "true" value is often determined by calculating the mean of test values performed on a common specimen at multiple laboratories in proficiency surveys. For example, if the mean of creatinine measurements is 1.0 for all labs with a standard deviation of 0.3 mg/dL, then a lab reporting a value of 1.9 mg/dL would be 3 SD from the mean, which implies inaccuracy. Precision: Measures the reproducibility of the assay such that if a test is performed multiple times for a given sample, the results should be tightly clustered around a certain value. For the same example above, if the "true" creatinine is 1.0, a lab result of 1.9 is inaccurate, but it would be considered precise if repeated measurements were 1.8, 1.9, and 2.0. Validation or Test Performance: Just like clinicians like to use statistics in deciding what tests to use for specific diseases, pathologists also have to consider statistics in deciding what tests and what test methodology to use. The test in question has to be compared to the "gold standard". In real life, there are very few "gold standard" tests and the "gold standard" might actually entail a compilation that considers history, physical examination, radiographic studies, laboratory tests, anatomic pathology results, and even looking at these factors in a retrospective manner.
Multiple Dosing
B. MULTIPLE DOSING OF DRUG X BY IV INJECTION 1. a. The concentration achieved with the first dose, C0, is 10 mg/40 liters or 250 ug/l. b. The dosing interval should be one elimination half-life, 4 hours. The Cpmax of Drug X to avoid side effects is 500 ug/l and the Cpmin for maintaining the therapeutic effect is 250 ug/l. Cpmin is half Cpmax so the dosing interval should be one elimination half-life or 4 hours. c. If the dosing interval is about the same as the elimination half-life, then Cpmax at ss will be about twice Co, or 500 ug/l, which is the desired value. d. 87.5% of ss is achieved in three half-lives, so four doses at 4-hr dosing intervals would be required to achieve a Cmaxss above 90% of the steady state value. 19-12 2. a. If the total clearance is reduced by 50% and the Vd stays the same, then the elimination half-life will be twice as long, 8 hours rather than 4 hours. b,c. If the same dosing regimen were used in this patient, then Cpave at steady state would be twice as great as in the first patient. Cpmax at ss would be less than doubled and Cpmin at ss would be more than doubled, and the difference would continue to be C0. d. a.) if the maintenance dose were kept the same and the dosing interval doubled, then Cpmax, Cpmin and Cpave at ss would be the same as in the first patient b.) if the maintenance dose were decreased by half to 5 mg and the dosing interval kept the same at 4 hr, then the Cpave at ss would be the same but the Cpmax at ss would be lower and the Cpmin at ss would be higher. e. It would take longer to reach ss in this patient, regardless of the dosing interval, because the elimination half-life is longer and the elimination half- life is the determinant of the time to achieve steady state.
I. General Principles and Definitions A. Virulence is a quantitative measure of pathogenicity: the number of organisms necessary to produce disease. 1. LD50 = 50% lethal dose 2. ID50 = 50% infectious dose
B. The infectious dose of an organism necessary to produce disease varies, and depends on the presence of virulence factors and host factors. C. Infectious disease results from a sufficient infectious dose of an organism entering a host and evading host defense mechanisms. Hosts with compromised immune systems are more susceptible to infections: 1. Immunodeficiency/immune defects due to a variety of factors increase susceptibility to infection and more severe disease outcomes: a. Genetic immunodeficiencies i. B cell deficiencies are associated with recurring bacterial infections ii. T cell deficiencies are associated with recurrent viral and fungal infections iii. Combined B and T cell deficiencies are associated with recurrent viral, bacterial, fungal, and protozoal infections iv. Phagocytic deficiencies v. Complement deficiencies b. Pre-existing infections/conditions that compromise host defenses, e.g. AIDS, diabetes, COPD c. Drug-induced immunodeficiency associated with organ transplant patients d. Immunosuppression associated with chemotherapy for cancer e. Autoimmunediseases f. Splenectomy g. Oldage,malnutrition,stress,pregnancy h. Tobacco use, drug and alcohol abuse, some medications D. Susceptibility to infections and disease outcomes are also influenced by host genetic factors which vary among individuals. Resistance and susceptibility genes have been implicated in mycobacterial diseases (tuberculosis and leprosy) and gastric ulcers due to Helicobacter pylori. E. Most infections are asymptomatic (inapparent, subclinical) because the host immune response is effective in clearing the organisms before disease is produced. How could you test someone to see if they have had an asymptomatic infection? F. Acute infections are characterized by rapid onset, often severe symptoms, and a short time course. The organism is cleared from the host. G. Chronic infection of a host may occur in which organisms continue to replicate, with or without producing symptoms. Asymptomatic chronic carriers are an important source of infection.
metoprolol
B1 antagonist
Niemann-Pick sphingomyelinase sphingolipid-->spingomyelin **may also have cherry red spot, skin lipid deposits
CNS, RES in spleen, liver, LNs, bone marrow zebra bodies, huge white puffy cells (vacoulated) Type A (~80%): severe, extensive neurologic involvement, death by 3; Type B: organomegaly but no CNS involvement
1. What were the relative potencies of norepinephrine and Alpha?
Based on KA as a measure of potency, alpha is 1.6 times more potent than norepinephrine (or norepinephrine is 0.6 times as potent as alpha). However, alpha has less maximum efficacy than norepinephrine and so if they act on the same receptors, alpha would be considered a partial agonist and norepinephrine a full agonist. (FlippedEc/Ec)
BPA toxin
Bisphenol A from polycarbonate bottles, coatings of food cans effect: estrogen mimic (proliferative effect)
Celecoxib selective NSAID inhibits COX-2 (~10:1 specificity)
COX-2 inhibition mediates therapeutic effects (antipyretic, analgesic, anti-inflammatory) NO COX-1 side effects (platelet effect, GI toxicity) juvenile, rheumatoid, osteoarthritis renal toxicity: sodium retention and edema ankylosing spondylitis, primary dysmenorrhea cardiovascular toxicity: possible increased risk of HA and stroke do not use in patients with atherosclerosis
CXC vs CC chemokines
CXC = an amino acid between two cysteines; major neutrophil chemoattractant and activator CC = no intervening AA; attract monocytes and lymphocytes chemokines are chemotactic cytokines; they attract a leukocyte to somewhere (i.e. inflammation)
The Structure of Bacterial Cells
Cell Wall Peptidoglycan Outer membrane of Gram- negative bacteria Surface fibers in some Gram-positive bacteria Sugar backbone with peptide side chains that are cross- linked Lipid A Polysaccharide Teichoic acid, Lipoteichoic acid Provides rigid support and shape, protects against osmotic pressure; site of action of penicillins & cephalosporins; is degraded by lysozyme. Toxic component of endotoxin. Major surface antigen used frequently in lab diagnosis. LPS-like. Cytoplasmic (Cell) Membrane Lipoprotein bilayer without sterols** Site of oxidative and transport enzymes. Ribosome RNA and protein in 50S and 30S subunits (70S) Protein synthesis; site of action of aminoglycosides, erythromycin, tetracyclines & chloramphenicol. Nucleoid DNA Genetic material Periplasm of Gram-negative bacteria Space between plasma membrane & outer membrane Contains many hydrolytic enzymes, including β-lactamases. "Nonessential" Components Capsule Polysaccharide* Protects against phagocytosis, environment; role in biofilms, attachment Pilus or Fimbria Glycoprotein Mediates attachment to host and to other bacteria; F (sex) pilus mediates attachment of 2 bacteria during conjugation & transfer of genetic material. Flagellum Protein Motility Secretion Systems (Type I-VI) Protein Transfer of virulence factors Spore Keratin-like coat; dipicolinic acid Provides resistance to dehydration, heat & chemicals; germination gives rise to single cell. Plasmid DNA Mobile genetic element containing genes for antibiotic resistance, toxins, etc. Nutrient Storage Granule Glycogen, lipids, polyphosphates Site of nutrients in cytoplasm. Glycocalyx Polysaccharide Similar functions as capsule
Lecture 36: Introduction to Bacteria: Classification, Structure & Virulence Factors, Part 2 Streptococcus pneumoniae vs Neisseria meningitidis
Cell Wall: Peptidoglycan Outer membrane of Gram-negative bacteria Lipid A endotoxin Polysacc Major surface antigen Surface fibers in some Gram-positive bacteria Teichoic acid LPS-like, CM: Lipoprotein bilayer without sterols**: Site of oxidative and transport enzymes. Ribosome: Protein synthesis; site of action of aminoglycosides, erythromycin, tetracyclines & chloramphenicol. Periplasm of Gram-negative bacteria: Contains many hydrolytic enzymes, including β-lactamases. G- = LPS, Pore, OM, PPS PPG NBP, CM, G+ = PPG, TA, LTA, CW, CM Lipopolysaccharide, LPS In OM of G- Endotoxin Composed of 3 units O-antigen repeats, core sugar, lipid A Most Common ID's seen at BMC E. Coli UTIs HIV Staph bacteremia Pneumonia Meningitis Cellulitis Diabetic foot infections Osteomyelitis Spontaneous peritonitis Infections in IC hosts, e.g. cancer patients on chemo Tuberculosis Teichoic Acid Polymers of ribitol or glycerol connected by phosphates. Found in outer layer of G+ cells. "LPS-like" in some G+ bacteria Can mediate attachment May contain antigenic determinants Cytoplasmic Membrane Phospholipid bilayer like eukaryotic cells, except it does not contain... Site of: Active transport of molecules Electron transport chain Synthesis of cell wall precursors Signal transduction Cytoplasm containing DNA (nucleoid), ribosomes (70S), granules, plasmids, transposons, etc. Capsule Polysaccharide* Protects against phagocytosis Pilus or Fimbrae Glycoprotein 2 types: (1) Fimbrae mediates attachment to cell surfaces; (2) sex pilus mediates attachment of 2 bacteria during conjugation & transfer of genetic material. Flagellum Protein Motility Secretion Systems (Type I- VI) Protein Transfer of virulence factors Spore Keratin-like coat; dipicolinic acid Provides resistance to dehydration, heat & chemicals; germination gives rise to single cell. Plasmid DNA Contains a variety of genes for antibiotic resistance and toxins. Nutrient Storage Granule Glycogen, lipids, polyphosphates Site of nutrients in cytoplasm. Glycocalyx Polysaccharide Mediates adherence to surfaces. Streptococcus pneumoniae Quellung reaction Capsules inhibit Phagocytosis Capsule-based vaccines promote opsonization E. coli is a common cause of UTIs Clostridium tetani with terminal spores diff types of secretion Spores: Keratin-like coat Dipicolinic acid is a Ca++ chelator Highly resistant to heating: are not killed by boiling (1000C), but are killed at 1210C. Medical supplies must be heated to 1210C for at least 15 minutes to be sterilized. Highly resistant to many chemicals, including most disinfectants. Must use "sporicidal" solutions to kill spores. Can survive for many years, especially in soil. Wounds contaminated with soil can get infected with spores and cause diseases such as tetanus and gas gangrene (caused by Clostridium species). Metabolically inactive. Antibiotics are ineffective against spores; plus they cannot penetrate coat. Formed when nutrients are limited, but germinate when nutrients become available. Usually see bacteria, not spores, in specimens from wounds (why?). Produced by members of only 2 medically important genera, Bacillus and Clostridium (Gram-positive rods). Infections resulting from spores can be attributed to either Bacillus or Clostridium species.
Table 3 above shows the frequency of some risk factors of the subjects at the beginning of the study. *RR is the relative risk of having the risk factor, comparing those who received aspirin to those who received placebo. For example, the relative risk of diabetes in the aspirin group versus the placebo group is 275/11,037 divided by 258/11,034, or 1.07. The p-values that were computed were based on a comparison of the frequency of having the risk factor (or not) among the two treatment groups. These p-values were most likely calculated using which of the following statistical tests:
Chi squared test. Differences in frequency are commonly tested using a chi-squared test. This test is not appropriate with very small numbers of subjects, but in this large study a chi-square test is entirely appropriate.
3. Explain the progression from acute inflammation to granulation tissue to scarring
Chronic Inflammation Acute inflammation indicates a process that has been present for a few hours to days, while chronic inflammation has been present for weeks, months, or even years. There are many different morphologic patterns of chronic inflammation but almost all include abundant lymphocytes, macrophages, and some degree of fibrosis. Chronic inflammation is an active process, which implies that it can be modulated or even terminated. There are several examples of chronic inflammatory conditions such as rheumatoid arthritis, atherosclerosis, and Crohn's disease (a form of chronic inflammatory bowel disease). Causes of chronic inflammation 1. Prolonged exposure to tissue injury, irritants or potentially toxic agents may cause chronic inflammation. In this situation the offending agent or insult is never removed so the inflammatory process persists. Some clinically important diseases, such as atherosclerosis and Alzheimer's disease, may result from prolonged exposure to irritants such as cholesterol (atherosclerosis) or beta-amyloid (Alzheimer's disease). 2. Immune mediated diseases such as autoimmune diseases and allergic diseases may result in chronic inflammation. In autoimmune diseases the body inappropriately recognizes host tissues as foreign antigens and mounts a specific inflammatory response. Most autoimmune diseases have a substantial infiltrate of lymphocytes and these cells are important in perpetuating the inflammatory response. These lymphocytes serve as a source of secreted cytokines to drive the inflammatory process. Patients are currently treated with drugs to inactivate cytokine activity. 3. Persistent infections may result in chronic inflammation, and will be discussed in further detail in the section on granulomatous inflammation. Evolution of acute inflammation into chronic inflammation. In some situations exposure to ongoing tissue injury will result in chronic inflammation and fibrosis. A skin ulcer represents example of this situation, and histologic examination of the ulcer provides a chronology of the inflammatory events. Starting at the top of the ulcer there is a fibrinopurulent exudate composed of fibrin and neutrophils. These are the same components present in the acute inflammatory response. The next layer contains granulation tissue, which is part of the healing response. Granulation tissue is given this name because on gross examination it appears that there are small red granules, which are actually capillaries. Granulation tissue is composed of a rich capillary network embedded in a loose matrix of fibro-connective tissue. Angiogenesis is the biological process that produces these newly formed blood vessels. The matrix also contains numerous chronic inflammatory cells including macrophages, mast cells, lymphocytes and plasma cells. An important cellular component of the granulation tissue is the fibroblast, which is responsible for producing collagen that forms the deepest layer of the ulcer. At the bottom of the ulcer are bands of collagen that will become scar tissue. This same sequence of wound healing occurs following the resolution of a myocardial infarction. Specifically, acute inflammation is followed by granulation tissue and the eventual replacement of the normal tissue by scar. Chronic inflammation may also be initiated by the presence of irritants such as a foreign body (i.e. suture material)
1. Describe the major cells present in chronic inflammation
Chronic inflammatory cells Monocytes - Macrophages are components of the mononuclear phagocytic system. They originate in the bone marrow as monoblasts, moved into the bloodstream after maturation and become monocytes. These monocytes then migrate to the tissue to become fixed cells where they are given specific names. The various cell types included in the mononuclear phagocyte system are microglia (in the CNS), macrophages (connective tissue and lymphoid organs), sinus lining cells (i.e., Kupffer cells of the liver and alveolar macrophages). Histiocyte is an older term and refers to a macrophage in the tissue with abundant cytoplasm. M1 or classically activated macrophages are important in acute inflammation by producing cytokines. M2 macrophages or alternatively activated macrophages are important in wound healing. Lymphocytes are composed of a stunning array of different subtypes including T cells and B. cells. Plasma cells which secrete immunoglobulins are also derived from lymphocytes. They are part of both the innate and adaptive immune system. Important cells in chronic inflammation include: CD4+ cells secrete numerous cytokines which help drive chronic inflammation. Among these are interferon gamma, secreted by Th1 cells, which active macrophages. IL-4, 5, and 13 are produced by Th2 cells which drive macrophages towards the alternative activation pathway and will also activate eosinophils. Additionally, IL-17 is produced by Th17 cells to recruit neutrophils. B cells, including antibody secreting plasma cells, are frequently found at sites of chronic inflammation. Eosinophils are the principal effector cell of antibody-dependent cellular cytotoxicity (ADCC) against helminths, as these cells express high levels of the IgE Fc receptor. Eosinophils are also found at local sites of inflammation in individuals with allergies. Basophils and mast cells are related cell types which become activated following the binding of antigen to surface-bound IgE. Basophils are found in blood whereas mast cells are found within tissues. Other stimuli, such as C3a and C5a, certain drugs and chemicals, as well as certain physical stimuli (cold, heat, sunlight) can also activate these cells. Following activation basophils and mast cells promptly (within seconds to minutes) release pre-formed granules. They are part of acute and chronic inflammation. Fibroblasts are found within tissues and are a prominent component of granulation tissue. Fibroblasts produce collagen which forms scar tissue and causes fibrosis.
Loratadine H1-->second generation antagonist
Claratin IP3/DAG-->Ca2+ reduced itching, rhinitis, conjuctivitis, hives better selectivity for H1 relative to other receptors less dry mouth (anti-muscarinic); less sedation due to charge @ physiological pH
Acute Appendicitis Case Describe the external surface of the appendix, what type of material is adherent in this area? Exudate composed of fibrin and inflammatory cells coats areas of the appendix.
Compare with the the shiny serosal surface of a normal appendix. What is the cause of the focal red discoloration in this cross section of the appendix? Area of impending perforation with hemorrhage, necrosis, and marked acute inflammation.
Pediatric Pathology I- CongenitalAnomalies(DevelopmentalGenetics) II- Prematurity 1. Neonatal Respiratory Distress Syndrome 2. Necrotizing Enterocolitis 3. Intraventricular and Germinal Matrix Hemorrhage III- Sudden Infant Death Syndrome IV- Pathologic Findings in Cystic Fibrosis (Molecular Genetic Abnormalities and Genetic Screening and Prenatal Diagnosis) • Pediatric pathology is considered a unique subspecialty within pathology since it is defined by an age group and not by an organ system or process. • Groups all diseases that occur during embryogenesis until early adulthood. • Knowledge of normal versus abnormal processes is extremely important.
Congenital Anomalies • Morphologic defects present at birth • Most common cause of mortality in the first year of life. • Contribute significantly to morbidity and mortality throughout the early years of life. • Include malformations, disruptions, deformations, sequence and syndromes. Trisomy 13: Patau Syndrome • Cleft lip/palate • Polydactyly • Microcephaly • Microphthalmia • Rocker bottom feet • Holoprosencephaly A) Micrognathia (Trisomy 18) B) Simian crease (Trisomy 21) C) Prominent occiput (Trisomy 18) D) Cleft lip and palate (Trisomy 13) E) Overlapping fingers (Trisomy 18) Prematurity - Gestational age of less than 37 weeks and weight less than 2500 grams. • Second most common cause of neonatal mortality (primary cause are congenital anomalies). • American College of Obstetrics and Gynecology (ACOG) estimates that 12% of all births in the United States are preterm deliveries. - Preterm premature rupture of placental membranes (PPROM) - Intrauterine infection - Uterine, cervical, and placental structural abnormalities - Multiple gestation (twin pregnancy) • Neonatal respiratory distress syndrome (hyaline membrane disease) • Necrotizing enterocolitis • Sepsis • Intraventricular and germinal matrix hemorrhage • Long-term complications, including developmental delay. Neonatal Respiratory Distress Syndrome (RDS) • Commonly observed in preterm infants, male gender and those delivered by cesarean section (decreased release of fetal glucocorticoids). • An estimated 24,000 cases of RDS are reported annually in the United States. • PE: dyspnea and fine rales heard on both lung fields. • Maternal history of diabetes (elevated fetal insulin). Diffuse bilateral atelectasis (alveolar collapse) causing a ground glass appearance. Immaturity of the lungs is the most important substrate on which this condition develops. • Main defect is deficiency of pulmonary surfactant. • Leads to increased surface tension, collapsed lungs (collapsed alveoli), progressive atelectasis and reduced lung compliance. • Results in deposition of a protein/fibrin-rich exudate in the alveolar spaces (hyaline membranes). Treatment: - Maternal steroids before birth - Artificial surfactant for infant - Mechanical ventilation (high frequency) - Oxygen supplementation Complications of Oxygen Therapy • Retrolental Fibroplasia (Retinopathy of Prematurity) • Intraventricular hemorrhage • Bronchopulmonary Dysplasia (BPD) RIB What is the pathogenesis of BPD? • Prolonged assisted ventilation at high oxygen concentrations. • Oxygen toxicity and mechanical ventilation damage the developing lung, leading to poor alveolar development. What is the pathogenesis of Retrolental Fibroplasia (Retinopathy of Prematurity)? Disorganized growth of blood vessels Oxygen toxicity leads to endothelial injury, resulting in fibrosis and neovascularization (disorganized growth of blood vessels is noted). Scar retraction causes the retina to detach Necrotizing Enterocolitis (NEC) • Incidence of disease is inversely proportional to gestational age. • Approximately 2500 cases occur annually in the United States. • Clinical presentation: - Abdominal distention - Absent bowel sounds - Bloody stools - Possible perforation (free air in abdomen) A) Duodenal atresia ("double bubble": dilated stomach, proximal duodenum on x-ray. Associated with Down syndrome). B) Hirschsprung disease (congenital megacolon. Lack of ganglion cells/enteric nervous plexuses in distal segment of colon. Normal portion of colon proximal to aganglionic segment is dilated. Associated with Down syndrome). C) Meckel diverticulum (persistence of the vitelline duct. May contain ectopic acid-secreting gastric mucosa and/or pancreatic tissue. Most common anomaly of the GI tract. The rule of 2's: 2 times as likely in males, 2 inches long, 2 feet from the ileocecal valve, 2% population, 2 first years of life, 2 types of epithelia: gastric/pancreatic). D) Pyloric stenosis (is an uncommon condition in infants that blocks food from entering the small intestine due to thickening of the pylorus muscles. It can lead to forceful vomiting, dehydration and weight loss). E) Necrotizing enterocolitis Intraventricular and Germinal Matrix Hemorrhage What are the predisposing factors for intraventricular hemorrhage? Prematurity Hypoxia Breech delivery What clinical symptoms may result from this? Apnea Lethargy Poor muscle tone Seizures SIDS is a disease of unknown cause. The National Institute of Child Health and Human Development defines SIDS as "the sudden death of an infant under 1 year of age which remains unexplained after a thorough case investigation, including performance of a complete autopsy, examination of the death scene, and review of the clinical history". • Infections (e.g., viral myocarditis or bronchopneumonia) are the most common causes of sudden "unexpected" death, followed by an unsuspected congenital anomaly. • Considered a multifactorial condition that reflects a delayed development of arousal and cardiorespiratory control. Lungs Cystic Fibrosis • Autosomal recessive disease. • Most common lethal genetic disease that affects Caucasian populations. • Primary defect is abnormal function of the epithelial chloride channel CFTR on chromosome 7. • Deletion of ∆F508 (most common mutation among Caucasians). • Affects fluid secretion in exocrine glands (salivary glands) and epithelial lining of respiratory, gastrointestinal (pancreas, liver, small bowel) and reproductive tracts. • Other: nasal polyps, meconium ileus in newborns, infertility in males (bilateral absence of vas deferens), and fat soluble vitamin deficiencies (A, D, E, K). • Refer to medical genetics course lectures
Describe the acute and chronic effects of the clinically important opioid classes
Coreine Morphine (u/k agonist) Fentanyl (u agonist) Meperidine (u agonist) Methadone (u agonist) Buprenorphine (1/2u ag + k antagonist) Nalbuphine (u antagonist, k agonist) Butorphanol (1/2u ag, k agonist) b-endorphin (u/g agonist) Met/Leu-enkephalin (u/g agonist) Dynorphin A (1-17) u/k agonist. Naloxon (u/g/k antagonist) Naltrexone (u/g/k antagonist) N-methylnaltrexone (u peripheral antagonist) Opium - mixture of alkaloid from Papaver somniferum Opiate - natural alkaloid (morphine/codeine) Opioid - (natural or synthetic compound with morphine-like properties; hundreds made but all clincally available are alkaloids) Opioid sturcture is related to morphine which includes 5 rings, 3-/6- hyroxyl group (phenolic/alchoholic), piperidine ring w N-methyl group, quaternary carbon at C13. Morphine is optically active; only the levorotatory isomer is an analgesic. Simple modifications of morphine make other active analgesics (Codeine: morphine O-methylated at position 3/ Heroin is morphine O-acetlyated at position 3 and 6. Replacing the N-methyl with larger group (allyl, cyclopropyl, cyclobutyl,) produces a copound with opioid ANTAGONIST properties. N-allyl derivatives of morphine (oxymorphone) and nalorphine (naloxone). Meperidine (Demerol) is a synthetic opioid with only fragments of the morphine structure.
infusion rate affects ____, while clearance rate (ClT) affects ___.
Cp_ss_max ; time to reach Cp_ss_max
• Identify toxicities of glucocorticoids associated with long-term systemic use.
D. Principles of Therapeutic Use 1. Single large dose relatively safe; one week treatment does not significantly affect HPA axis 2. Beneficial effects only palliative 3. Prolonged systemic treatment is NOT safe and may cause iatrogenic Cushing's syndrome; toxicities include osteoporosis with fractures, muscle wasting, hypertension, hyperglycemia, infection, impaired wound healing, cataracts, behavioral disturbances, slowed growth in children. 4. Abrupt termination of prolonged therapy is life-threatening because of suppression of HPA axis; symptoms of adrenal insufficiency include anorexia, lethargy, joint pain, postural hypotension, etc.; restoration of HPA axis takes months 5. Measures to reduce risk of toxicities a. Restrict use to condition where truly indicated b. Use local administration MDI aerosol delivery with spacer for pulmonary indications Nasal sprays for allergic rhinitis Topical preparations for skin and eye Injection into joint Intrathecal for post-herpetic neuralgia Slow release capsule with high first pass effect for inflammatory bowel disease (budesonide) A. Therapeutic Use For some clinical conditions such as prevention of rejection reactions following organ transplantation, glucocorticoids are used in combination with other immunosuppressive agents. Many of these agents increase the risk of infections and cancer, and some also have toxicities specific to their chemical class. Immunosuppressive agents are used for treatment of autoimmune diseases such as rheumatoid arthritis, prophylaxis for or treatment of transplant rejection, and cancer; specific indications depend upon the drug class. (The pharmacology of immunosuppressants will be discussed further in the Renal, Rheumatology, and Oncology modules.)
A 20 year old college student came to the emergency room complaining of abdominal pain and nausea. He was febrile with a temperature of 101 F. On examination he was found to have rebound tenderness in the right lower quadrant. A CBC revealed a leucocytosis of 11,000 with 90% neutrophils.
Describe the gross, microscopic, cellular, and molecular features of acute inflammation in the setting of acute appendicitis. Relate clinical signs and symptoms and clinical laboratory data to these processes
Which of the three drugs would be the best candidate for treating difficulty in urination secondary to benign prostatic hyperplasia (BPH)? Why?
Drug B would be the best candidate for treating BPH because it is selective as an alpha 1 receptor antagonist, a class of drugs that are efficacious in decreasing the obstruction in urinary outflow associated with this condition, by relaxing smooth muscle of the prostate and base of the bladder.
If used for treatment of hypertension, which of the three drugs would be most likely to produce postural hypotension and reflex tachycardia as a side effect? Why? POSTURAL HYPOTENSION IS CAUSED BY ALPHA 1 RECEPTOR ANTAGONISTS (PREVENTS REFLEX VASOCONSTIRCTION DUE TO DROP IN BP IN CAROTID)
Drugs B and C would both be likely to produce postural hypotension due to alpha 1 receptor antagonism. Drug B is selective as an alpha 1 receptor antagonist and therefore prevents the reflex vasoconstriction in response to a drop in blood pressure in the carotid sinus. Drug B would be expected to cause a tachycardia in response to the orthostatic hypotension, due to reflexmediated activation of beta 1 receptors in the heart. Drug C could also act as a beta blocker to reduce blood pressure, but because it is nonselective, it will also inhibit alpha-1 receptors at effective concentrations. Blockade of beta-2 mediated vasodilation may moderate this somewhat, depending upon circulating epinephrine levels. Note also that you would expect less reflex tachycardia than with B, due to the beta blocking effect of C. For any degree of blood pressure lowering effect, Drug B would be expected to cause greater risk of orthostatic hypotension and reflex tachycardia than Drug C. Drug A selectively blocks beta 1 receptor in the heart and so its antihypertensive effect is through reduction in heart rate and contractility. Reflex increase in total peripheral resistance mediated through alpha 1 receptors would not be affected by this drug and so there would be substantially less risk of orthostatic hypotension than with the other two drugs.
Electrical Injury
Electrical injury results from contact with low-voltage current at home or in the workplace, or with high-voltage current from high power lines or lightning. The low-voltage current is usually 120 or 220v and is alternating (periodically reverses direction). Wet skin lowers resistance to the conductance of the current (about 100-fold) and, since current = voltage/resistance, people can get electrocuted in a bath tub by a hair dryer. The severity of electrical injury is determined by the type and intensity of current, the path of current, the resistance of different tissues, and the duration of exposure. Contact with current results in several types of injury: burns at entry and exit sites and internal organs; ventricular fibrillation or cardiac and respiratory center failure (due to disruption of normal electrical impulses); paralysis of medullary centers and extensive burns from high voltage current. Also, alternating current can cause tetanic muscle spasms (sustained muscle contraction), resulting in prolonged (irreversible) clutching of the current source which, in severe cases, leads to spasm of the chest-wall muscle, causing asphyxia (suffocation) due to oxygen deprivation.
Common dietary supplements for weight loss
Ephedra-related compounds: - 0.9kg weight loss/month > placebo - But 2.2-3.6x increase palpitations, psychiatric, autonomic, and GI symptoms Chitosan --> blocks clinically insignificant amount of fat absorption Chromium --> may play a role in insulin sensitivity but not helpful for weight loss Hydroxycytric Acid --> evidence equivocal (ambiguous, open to more than one interpretation)
why do mAbs have a long half-life?
FcRn recycling mechanism - FcRn = receptor, binds Fc region of mAb, aka "Brambell Receptor" - FcRn binds Fc of mAb in acidic environment of early endosome, mAb taken into cell - most *doesn't* go to lysosome for degradation. Instead, it's recycled in the endosome back to the surface where mAb is re-released 3 week HL
Three investigational drugs, A, B, and C were tested for their capacity to: competitively antagonize epinephrine-induced: a. increase in heart rate (B1) b. relaxation of bronchial smooth muscle (B2) c. contraction of arterial smooth muscle. (A-1) Experiments were carried out with isolated tissues in an organ bath, which allowed accurate control of drug concentrations. KB's were determined for all three drugs. Results were as follows: B1 B2 A1 50um 5mM 5mM (B1 ant) 1mM 1mM 50uM (A1 ant) 1uM 1uM 1uM (Nonsel ant)
First identify the receptors that mediate each of the effects above. The epinephrine-induced effects are mediated by the following receptors: heart rate increase by beta 1 adrenergic receptors, bronchial smooth muscle relaxation by beta 2 adrenergic receptors, arterial smooth muscle constriction by alpha 1 adrenergic receptors. Then, identify the receptor selectivity for each drug by comparing its KB for each tissue. Then apply that information to answer the following questions. The drugs act as competitive adrenergic receptor antagonists on all three receptor types. They can be classified by their selectivity with the lowest KB indicative of their most selective site of action. Drug A: beta 1 receptor antagonist, Drug B: alpha 1 receptor antagonist, Drug C: nonselective antagonist at all three receptor types.
DSHEA Labeling Requirements
For dietary supplements - Name of product with word "supplement" - full disclosure of all ingredients - identity and strength (ingredient name (source), quantity (per serving), plant part) - net quantity of contents - name and place of business of manufacturer, packer, or distributor - directions for use - must have disclaimer: not evaluated by FDA; not intended to diagnose, cure, or prevent disease
Some examples:
GI tract: G+ cocci: Staphcoccus aureus (food poisoning): enterotoxin is a superantigen G+ rod: Clos difficile/Pseudomembranous colitis: Depolymerize actin filament G- rod: Vibrio cholerae/Cholera Stimulates adenylate cyclase Escherichia coli O157:H7/Bloody diarrhea Inactivates protein synthesis Escherichia coli/Watery diarrhea Labile toxin stimulates adenylate cyclase; Stable toxin stimulates guanylate cyclase Nervous: 1. Gram-positive rods Clostridium botulinum/Botulism Neurotoxin inhibits acetylcholine release Respiratory Tract 1. Gram-positive rods Corynebacterium diphtheriae/Diphtheria Inactivates protein synthesis 2. Gram-negative rods Bordetella pertussis/Whooping cough Stimulates adenylate cyclase; inhibits chemokine receptor Skin, Soft Tissue, or Muscle 1. Gram-positive cocci Staphylococcus aureus/Scalded skin syndrome Protease cleaves desmosome in skin Streptococcus pyogenes/Scarlet fever Erythrogenic toxin is a superantigen 2. Gram-positive rods Clostridium perfringens/Gas gangrene Lecithinase cleaves cell membranes Bacillus anthracis/Anthrax Edema factor is an adenylate cyclase; lethal factor is a protease Systemic Systemic 1. Gram-positive cocci Staphylococcus aureus Toxic shock syndrome toxin is a superantigen
6. Name the cellular components of granulomatous inflammation and describe the causes of this type of inflammatory response.
Granulomatous Inflammation Granulomas are the predominant microscopic feature of granulomatous inflammation, exactly as one would expect. The granuloma is a small focus of chronic inflammation. The characteristic cell of the granuloma is a macrophage which has been transformed into a cell termed an epithelioid macrophage. The epithelioid macrophage is a large cell with abundant, pale, pink cytoplasm that looks like an epithelial cell. These cells are typically clustered in the center of the granuloma. Surrounding these macrophages is a collar of lymphocytes. This close juxtaposition of the macrophages and lymphocytes allows robust cell to cell communication, similar to that described for the autoimmune diseases. As in the autoimmune diseases, many of the same cytokines are critical for the granulomatous response. A distinctive feature of granuloma is the presence of multi-nucleated giant cells. As the name suggests, these are large cells with abundant eosinophilic cytoplasm and numerous nuclei. Multi-nucleated giant cells are formed by the fusion of individual macrophages. Granulomas may also have an element of fibrosis. Granulomas are formed in an attempt to contain an offending agent that a single cell cannot handle alone. The inciting agent is typically near the center of the granuloma. Special studies may be necessary to locate the inciting agent, such as acid fast stains to look for mycobacteria or polarized light to identify foreign bodies. Determining the cause of the granuloma is critical, since it will direct the therapy of the patient. Causes of granulomatous inflammation. Common causes of granulomatous inflammation are: 1. Certain bacterial infections, most notably infections associated with mycobacteria, resulting in diseases such as tuberculosis and leprosy. 2. Certain fungal and parasitic infections, such as histoplasmosis and schistosomiasis. 3. Aseptic foreign bodies, like suture threads, asbestos, talcum powder (once used for surgical gloves) 4. Unknown causes associated with specific diseases, such as sarcoidosis and Crohn's disease. Many chronic inflammatory diseases are treated with inhibitors of inflammation. Some of these treatments are non-specific, such as glucocorticoids which decrease multiple aspects of the inflammatory response. Other treatments are relatively specific, such as the use of cytokine inhibitors. There are multiple TNF inhibitors approved by the Food and Drug Administration for the treatment of chronic inflammation. Some of these were discussed in the immunology course in the first year. However, many of the cytokines in chronic inflammation are essential components to keep infections under control. It is well recognized that blocking TNF to treat chronic inflammatory diseases significantly increases reactivation of tuberculosis. Cytokine inhibitor therapy has become sufficiently widespread that a standardized suffix nomenclature has been developed to categorize the agents. A soluble receptor ends with -cept (etanercept, the TNF soluble receptor). Chimeric monoclonal antibodies end in -mab (infliximab directed against TNF). A humanized antibody is denoted with -zumab (tocilizumab, the monoclonal antibody directed against the IL-6 receptor).
• Distinguish H1 from H2 receptor antagonists with respect to therapeutic use.
H1 Receptor Antagonists H1 receptor antagonists are highly selective for H1 as compared to H2 receptors. Doses that inhibit the H1 mediated effects of histamine released from mast cells have no effect on histamine-induced acid secretion by parietal cells in the stomach The first generation agents differ from the second generation in that the older drugs are relatively nonselective with respect to other actions including local anesthetic action, muscarinic receptor blockade, weak alpha-adrenergic blockade, and prominent sedative effects. This group of drugs led to the discovery of other classes of agents, such as drugs used in the treatment of psychosis. The second generation drugs have minimal antimuscarinic activity and insignificant sedative effects due to limited access to the CNS. Some are prodrugs, some are cleared predominantly by the kidney, and some are formulated for topical administration (intranasal or ophthalmic use). A. Agents: H1 antagonists share the structural motif shown below. They differ from the H2 antagonists, which have an imidazole moiety like histamine. First Generation H1: Sedation/Antimuscaric Chlorpheniramine + + diphenhydramine +++ ++ Hydroxyzine ++ + Promethazine ++ ++ Therapy Use First Gen H1: a. Allergic responses such as allergic rhinitis, conjunctivitis, and urticaria b. Anti-emetic, motion sickness, sedative-hypnotics with OTC availability Side effects: Sedation, antimuscarinic effects (acute toxicity resembling atropine poisoning with CNS excitation); allergic dermatitis a common paradoxical effect of topical antihistamines Second Generation H1: Carboxlate residue, charged at physiological pH, less distribution into the CNS (Loratadine, fexofenadine, +) Therapy 2nd Gen H1: Allergic responses such as allergic rhinitis, conjunctivitis, and urticaria; reduce nasal itching, watery eyes, rhinorrhea, and sneezing associated with allergic rhinitis, but not the nasal congestion; nasal corticosteroids in contrast reduce the latter symptom. Treatment of mastocytosis. Side effect: Lack of sedative or antimuscarinic effects. Several agents were found, after marketing, to cause a potentially fatal arrhythmia (a ventricular tachycardia referred to as torsades de pointes), because of block of certain potassium channels in the heart. The risk, which was rare, increased when these agents were taken with drugs that inhibited their biotransformation by CYP 3A4 (such as erythromycin). One of these, terfenadine (SELDANE) was withdrawn from the market and replaced by its active metabolite, fexofenadine, which is not cardiotoxic. H1 and H2 Receptor Antagonists in combination Rarely, inflammatory effects of histamine released from mast cells and basophils are mediated by H2 receptors, as well as H1 receptors. Under those conditions, H2 receptor antagonists are used in combination with H1 receptor antagonists. H2 receptor antagonists, for which ranitidine is prototypic, are highly selective for H2 as compared to H1 receptors. Their primary clinical indications are prevention and treatment of gastrointestinal ulcers, gastric acid hyper-secretory conditions, and gastro-esophageal reflux disease. (These drugs will be discussed further in the Gastroenterology Module.) Inhibitors of Mast Cell Function: Inhibitors of Histamine Release: Cromones inhibit mast cell degranulation, and the release of histamine and other mediators, in response to antigen/IgE binding. These drugs are very poorly absorbed by the oral route and are administered by inhalation. Side effects are mostly due to direct irritant effects of inhaled powder. They are used for prophylaxis against allergic rhinitis and asthma. . IgE Antagonists: Omalizumab is a humanized monoclonal antibody with affinity for the Fc region of IgE. Binding blocks the ability of IgE to bind to the FcRI receptor on mast cells, basophils and other cell types. This IgG therapeutic, administered s.c., is very slowly absorbed and has a long elimination half-life (26 days). Due to risk of anaphylaxis, the drug must be administered by a healthcare provider and not by the patient. An expensive agent, its use is limited to those patients for whom other therapeutic agents have been found inadequate. The drug was approved for asthma and more recently for chronic spontaneous urticaria. The role of H1 receptor antagonists, cromones, and the IgE antagonists in the prevention and treatment of asthma will be further discussed in the Pulmonary Module.
• Compare first and second generation H1 receptor antagonists with respect to selectivity for peripheral vs. central effects.
H1 receptor responses: 1. Dilation of arterioles and venules, mediated by release of NO from vascular endothelium 2. Increased capillary permeability 3. Constriction of the larger arteries/veins 4. Constriction of bronchial smooth muscle 5. Stimulation of sensory nerve endings (itch, flare) 6. CNS arousal H2 receptor responses: 1. Stimulation of gastric acid secretion 2. Vasodilation (slower onset and longer duration relative to H1 effect) mediated by H2 receptors on smooth muscle. 3. Effects on cardiac contractility and rate similar to beta-1 adrenergic stimulation
Centrilobular Necrosis and Periportal Steatosis
Hepatotoxic Drugs - Acetaminophen is an example of a hepatotoxic drug - Its toxic effect is dose dependent but it is modulated by individual susceptibility and also exposure to cytochrome P-450 enzyme inducers such as ethanol or phenobarbital. - Acetaminophen poisoning is currently the most frequent cause of acute liver failure in the US. • Drug Hypersensitivity Reactions - - - Most drug reactions are idiosyncratic occurring at therapeutic doses but only in a tiny fraction of exposed individuals (1/1000 - 1/100,000). Most are mild, producing a viral hepatitis like syndrome, a cholestatic hepatitis and rarely massive hepatic necrosis. Severe hepatic drug reactions represent the most frequent reasons cited for the withdrawal from the market of an approved drug
Q1 Discussion
I. CLINICAL PHARMACOKINETICS OF CHLORAMPHENICOL: EFFECTS OF DISEASE, AGE, AND FORMULATION A. PHARMACOKINETICS OF CHLORAMPHENICOL IN PATIENTS WITH RENAL AND HEPATIC DISEASE: Estimates of the range (or variance) of the elimination half-life in patients are necessary for making statistical comparisons among groups. In addition, the range may provide information relevant to prediction in individual patients. The extent of disease may correlate with the magnitude of change in drug clearance. The data presented in Table I indicate that in patients with hepatic disease (but not renal disease) the half-life of chloramphenicol is prolonged. The range is also increased, probably based on the degree of hepatic impairment. These findings in human subjects are consistent with the observations in dogs that the 12&16-10 drug is cleared primarily by nonrenal mechanisms (glucuronide conjugation). Therefore, the dosing regimen of chloramphenicol should be modified to a longer dosing interval in patients with hepatic disease. B. PHARMACOKINETICS OF CHLORAMPHENICOL IN INFANTS: Inspection of the plasma concentration data in Table II indicates that the half-life of total nitro compounds (chloramphenicol and metabolites) is markedly prolonged in neonates (> 24 hr), but the volume of distribution normalized for body weight (1.0 l/kg) is similar to that in adults. Deficiency in neonates of glucuronyl transferase, the enzyme that conjugates chloramphenicol (as well as other drugs and endogenous compounds such as bilirubin), results in reduced total clearance of chloramphenicol. A longer dosing interval of chloramphenicol is required in infants than in adults to avoid accumulation of the drug to toxic levels. C. EFFECT OF FORMULATION ON CLINICAL PHARMACOKINETICS OF CHLORAMPHENICOL ADMINISTERED ORALLY: The plasma concentrations of chloramphenicol and its metabolites are higher from Preparation A than from Preparation B. The ratio of the areas under the plasma concentration versus time curves (AUCs) suggests that B has only 35% the bioavailability of A. Biopharmaceutical factors such as the excipients or larger crystal sizes of the drug in the capsules may lead to slower dissolution and explain the poor bioavailability of B. Generic drugs are generally less expensive than proprietary preparations. To gain FDA approval for marketing manufacturers must document to the FDA that their product has a bioavailability within ± 20% of the proprietary standard. Product B would not be approved for marketing. Concern about this issue has reemerged due to illegal importation by internet pharmacies of drug products manufactured in off-shore sites (Science 305:481, 2004).
• Explain the effect of exogenous glucocorticoid administration on regulation of the synthesis of endogenous glucocorticoids.
I. Fundamental Aspects of Adrenal Steroid Action A. Principal Endogenous Adrenal Steroids: 1. Glucocorticoids (GC): cortisol, corticosterone -- essential for life! 2. Mineralocorticoids (MC): aldosterone 3. Androgens (weak): dehydroepiandrosterone B. Regulation of Adrenal GC Secretion Not stored or actively secreted; diffuse out of synthesizing adrenal cell; plasma levels determined mainly by rate of synthesis; corticotropin (ACTH) released from anterior pituitary in response to CRF from hypothalamus increases synthesis rate of GC; feedback inhibition: GC inhibits CRF release and transcription of proopiomelanocortin gene (source of ACTH), so ACTH and GC synthesis decrease; cortisol primarily bound in plasma and cleared by biotransformation with a half-life of 1-1.5 hrs. C. Mechanism of Steroid Action 1. Receptor subtypes a. GC receptor - activated by GC b. MC receptor - activated by both MC and GC 2. GC selectivity of cortisol: Cortisol binds MC receptor and GC receptor (hGR) with similar affinity. Cortisone has low affinity for MC receptor. In kidney and certain other tissues, an enzyme rapidly converts cortisol to cortisone and thereby prevents the former from activating the MC receptor 3. Signaling mechanism: Activated receptors are translocated to the nucleus, where they bind directly to specific DNA sequences (glucocorticoid response elements, GREs), transcriptional activators, and coregulators and thereby increase or decrease expression of target genes (10-20% of expressed genes in a cell) 4. Effects are generally slow in onset, long-lasting, and often permissive. 5. Inverse relationship between plasma levels of GC and expression of GC receptor.
Understand the role of the pathologist in investigating Sudden Infant Death Syndrome (SIDS).
II. Sudden Infant Death Syndrome (SIDS) SIDS is a disease of unknown cause. The National Institute of Child Health and Human Development defines SIDS as "the sudden death of an infant under 1 year of age which remains unexplained after a thorough case investigation, including performance of a complete autopsy, examination of the death scene, and review of the clinical history." SIDS is the leading cause of death between age 1 month and 1 year in the USA and the third leading cause of death overall in infancy, after congenital anomalies and diseases of prematurity and low birth weight. Autopsy usually fails to provide a clear cause of death but helps identify other causes of sudden unexpected death in infancy, such as an unsuspected infection, congenital anomaly, or a genetic disorder. SIDS is considered a multifactorial condition that reflects a delayed development of arousal and cardiorespiratory control. Other causes include maternal smoking during pregnancy, young maternal age, frequent childbirths, and inadequate prenatal care. African Americans and American Indians have significantly higher rates of SIDS deaths than Caucasians. Among environmental factors, prone sleeping position, sleeping on soft surfaces, and thermal stress are possibly the most important modifiable risk factors for SIDS. In SIDS cases it is important to carefully examine the scene of death and do a complete postmortem examination. Infections (e.g., viral myocarditis or bronchopneumonia) are the most common causes of sudden "unexpected" death, followed by an unsuspected congenital anomaly.
Time Course
II. Time-Course of Drug Effect A. Relationship between Drug Dose and Duration of Drug Effect (Dose- Duration Curve*) Under certain conditions (including i.v. route of administration, first-order kinetics, and close temporal relationship between concentration of drug at target site and magnitude of drug effect), the duration of action of a drug (above a specified level of effect) is proportional to the logarithm of the dose. Consequently, geometric increases in dose result in only arithmetic increases in the duration of action. So, for example, a doubling of the dose increases the duration of action by one elimination half-life; a quadrupling of the dose increases the duration by two half-lives, etc. Increasing the drug dose, therefore, may not be the best way to increase the duration of drug effect, especially for drugs with short elimination half-lives and low therapeutic indices. The elimination half-life of a drug and its threshold dose for a particular level of drug effect can be estimated experimentally by monitoring the effect of the drug as a function of time after drug administration. Data obtained from several doses can then be evaluated by examining the duration of a given level of effect as a function of the natural logarithm of the dose, as illustrated below on the right. The slope is directly proportional to the elimination half-life; the steeper the slope (i.e., increase in duration with an increase in dose), the longer the elimination half-life. Doubling of the dose increases duration by one half-life of elimination (see on left below). The x- intercept of the ln dose-duration plot indicates the ln of the threshold dose; the smaller the x-intercept the greater the potency of the drug. Duration of Action = ( t1/2 ) ( ln Dose - ln Threshold Dose ) 0.693 B. Discrepancies between Pharmacokinetics of a Drug and Kinetics of its Effects 1. Multicompartmental drug distribution a. If the target site of a drug effect is located outside the plasma compartment, then slow distribution to the target site may delay the onset of action and prolong the effect. b. If the target site of drug effect is in the same compartment as plasma (such as the brain and other rapidly perfused tissues), then drug redistribution from the target site to another compartment such as fat may shorten the duration of action relative to the duration of drug in the body (e.g., lipophilic drugs that act in the brain). 2. The drug effect may be mediated by irreversible interaction with a target site. Duration of action then depends on the resynthesis rate of functional target (e.g., aspirin inhibits platelet function by irreversible, covalent modification of cyclooxygenase; the effect persists for days despite the very short plasma half-life of aspirin; restoration of platelet function requires new platelet synthesis). 3. The drug effect may be mediated by inhibition of synthesis of downstream effectors. Onset of action then depends on the effector with the shortest elimination half-life; duration of action depends on resynthesis rate of that effector (e.g., the anticoagulant warfarin inhibits vitamin K function essential for synthesis of clotting factors). 4. The drug effect may be mediated by an active metabolite. Onset and duration of action then depend on the pharmacokinetics of the metabolite(s), not the parent compound (e.g., many benzodiazepine anti-anxiety agents).
Recognize pathologic findings in cystic fibrosis.
III. Pathologic findings in Cystic Fibrosis Cystic fibrosis is an autosomal recessive disease considered the most common lethal genetic disease that affects Caucasian populations. It is caused by defects in epithelial transport which affects fluid secretion in exocrine glands and the epithelial lining of the respiratory, gastrointestinal, and reproductive tracts. Clinically it manifests as chronic lung disease, pancreatic insufficiency, steatorrhea, malnutrition, hepatic cirrhosis, intestinal obstruction, and male infertility. The primary defect in cystic fibrosis results from abnormal function of the epithelial chloride channel protein that is encoded by the cystic fibrosis transmembrane conductance regulator (CFTR) gene on chromosome 7. The pancreas shows changes beginning with accumulation of mucus in the small ducts with some dilation of the exocrine glands. In advanced cases, the ducts are totally occluded, causing atrophy of the exocrine glands and progressive fibrosis. Thick viscid plugs of mucus may also be found in the small intestine of infants leading to small-bowel obstruction (meconium ileus). In the liver, bile canaliculi are occluded by mucinous material, with ductular proliferation, portal inflammation, hepatic steatosis and with time focal biliary cirrhosis may develop. Salivary glands show progressive dilation of ducts, squamous metaplasia of the lining epithelium, and glandular atrophy followed by fibrosis. Lung changes are the most serious complications of this disease. The bronchioles are often distended with thick mucus associated with marked hyperplasia and hypertrophy of the mucus-secreting cells. Superimposed infections give rise to severe chronic bronchitis, bronchiectasis and lung abscess formation. Infectious agents include Staphylococcus aureus, Hemophilus influenzae, and Pseudomonas aeruginosa. Burkholderia cepacia, an opportunistic bacterium, has been associated with fulminant illness. Other opportunistic pathogens include Stenotrophomonas maltophila, nontuberculous mycobacteria, and allergic bronchopulmonary aspergillosis. Azoospermia, infertility and congenital bilateral absence of the vas deferens are frequent findings in these patients. Refer to Medical Genetics Molecular Genetic Abnormalities and Genetic Screening and Prenatal Diagnosis Lectures.
II. Typical Stages of an Infectious Disease A. Incubation period: the period between acquisition of the organism (or toxin) and the onset of specific symptoms. B. Prodrome: period during which nonspecific symptoms occur, including fever, malaise, loss of appetite. What causes these nonspecific symptoms? C. Specific Illness period: period during which the characteristic signs and symptoms are observed. D. Recovery Period: period during which the illness abates and patient returns to a healthy state.
III. Stages in Bacterial Pathogenesis A. Transmission from an external source into a portal of entry B. Entry C. Evasion of primary host defenses D. Adherence E. Colonization F. Disease symptoms; usually due to toxin production, by-products of bacterial growth, inflammation and/or invasion, or immunopathogenesis G. Host immune response H. Progression or resolution of disease IV. Determinants of Bacterial Pathogenesis Bacterial virulence factors enhance the ability of bacteria to cause disease, and are often identified as such when organisms without them are demonstrated to be non-pathogenic. Many virulence factors are encoded by genes clustered in pathogenicity islands, whose expression may be regulated by environmental factors. A. Transmission 1. Person-to-person;fomites;ingestion;zoonotic 2. Manybacteriasurviveinmultipleenvironmentsbydifferentiallyexpressing specialized genes. B. Entry 1. Major portals of entry into the body include mucosal surfaces of oral cavity, respiratory, GI, genitourinary tracts; also skin, eyes. 2. These sites have multiple protective mechanisms that bacteria have to overcome to establish infection. C. Evasion of primary host defenses 1. Primaryhostdefensesinclude: a. Normal flora b. Antimicrobial enzymes (e.g. lysozyme) and factors (defensins) in mucosal secretions c. Cilia and mucous in lungs; alveolar macrophages d. IgA in mucosal secretions e. Mechanical mechanisms: eye blinking, swallowing, peristalsis, urine flow, etc. 2. Bacterial virulence factors involved in evasion of primary host defenses: a. Immunoglobulin A (IgA) protease i. degrades IgA so organism can adhere to mucous membranes. b. Leukocidins i. destroy leukocytes and macrophages c. Coagulase i. accelerates formation of fibrin clots from fibrinogen. ii. anti-phagocytic by coating organisms with fibrin. d. Anti-phagocytic factors i. Capsules prevent phagocytes from adhering to bacteria. e. Protein A i. binds to Fc region of IgG and prevents activation of complement. f. Many bacteria also undergo antigenic variation to evade the host immune response. g. Formationofbiofilms. h. Growth or persistence inside host cells.
6. Spores a. Highly resistant structures formed intracellularly by certain bacteria (Gram-positive bacilli: Bacillus and Clostridium) when nutrients are scarce or under adverse environmental conditions. b. Composed of bacterial DNA, small amount of cytoplasm, cell membrane, peptidoglycan, a little water, and a thick, keratin-like coat. c. The outer coat provides remarkable resistance to heat, dehydration, radiation and chemicals; likely due to dipicolinic acid, a calcium ion chelator found only in spores. d. Have no metabolic activity and can remain dormant for years. e. When water and nutrients become available, or low O2 conditions occur, spore may germinate and give rise to a single bacterial cell.
Important Features of Spores Medical Implications Highly resistant to heating: are not killed by boiling (1000C), but are killed at 1210C. Medical supplies must be heated to 1210C for at least 15 minutes to be sterilized. Highly resistant to many chemicals, including most disinfectants. Must use "sporicidal" solutions to kill spores. Can survive for many years, especially in soil. Wounds contaminated with soil can get infected with spores and cause diseases such as tetanus and gas gangrene (caused by Clostridium species). Metabolically inactive. Antibiotics are ineffective against spores; plus they cannot penetrate coat. Formed when nutrients are limited, but germinate when nutrients become available. Usually see bacteria, not spores, in specimens from wounds (why?). Produced by members of only 2 medically important genera, Bacillus and Clostridium (Gram-positive rods). Infections resulting from spores can be attributed to either Bacillus or Clostridium species.
What is the predominant type of nucleated cell? Segmented neutrophil, band forms would also be increased The patient was taken to surgery emergently and his appendix was removed.
Key components of the inflammatory response
Epidemiology
In the United States, use of herbal medicine declined in the early 1900s only to experience a resurgence beginning in the 1960s that was part of a larger movement towards using natural, nonconventional approaches to health care [2]. A 1990 national telephone survey of complementary and alternative medicine use by US adults demonstrated that 2.5 percent of respondents used herbal medicines [6]. A follow-up 1997 national survey showed almost a fivefold increase, with 12.1 percent of US adults reporting herbal medicine use in the previous year [7]. One factor contributing to this dramatic increase was congressional passage of the Dietary Supplement Health and Education Act (DSHEA) in 1994. DSHEA allowed manufacturers to market their herbal products without prior demonstration of safety or efficacy. (See 'Regulation' below.) Data from the 2012 National Health Interview Survey (NHIS) Alternative Medicine Supplement showed that 17.7 percent of US adults had used natural products in the previous year, including herbs and other naturally occurring non-botanical supplements such as glucosamine sulfate (derived from crustacean shells) and fish oils [8]. The following natural products were the 10 most commonly used by US adults in the NHIS survey (percentages are the rate of use among US adults): ● Fish oil (7.8 percent) ● Glucosamine or chondroitin (2.6 percent) ● Probiotics or prebiotics (1.6 percent) ● Melatonin (1.3 percent) ● Coenzyme Q-10 (1.3 percent) ● Echinacea (0.9 percent) ● Cranberry (0.8 percent) ● Garlic (0.8 percent) ● Ginseng (0.7 percent) ● Ginkgo biloba (0.7 percent) National Health and Nutrition Examination Survey (NHANES) data show that use of supplements (including vitamins, minerals, and non-vitamin, non-mineral supplements) by noninstitutionalized adults in the United States remained stable from 1999 to 2012, with 52 percent of US adults reporting use from 2011 to 2012 [9]. Use of supplements other than multivitamin products was reported by 34 to 39 percent
1. Identify the cells typically found during acute inflammation
Inflammation is the host response to injury or infection. It may be considered as immunology when there is blood flow. Acute inflammation refers to a process which develops in a few minutes to hours, and typically resolves within a few days. The hallmark cell of acute inflammation is the neutrophil. Leukocytes are the white blood cells (4.0-11.0x1000/ul) found within the bloodstream or present in the tissue. The normal number of white blood cells in the peripheral blood is listed in table 1. Neutrophils are the predominant cell (1.8-7.8k/ul), followed by lymphocytes(1-4.5k/ul). In normal individuals there are relatively few monocytes (.1-.6k/ul) or eosinophils (0-.5k/ul) Neutrophils are the major cell type mediating acute inflammation. A mature neutrophil is 12-14 microns in diameter and has a characteristic multi-lobed nucleus and pale staining cytoplasm. Cytoplasmic granules can be seen in a routine blood smear stain (Wright-Giemsa stain). They are short-lived cells, with a half-life in blood on the order of hours. They typically survive in tissues for only a few days and do not recirculate back to the blood. In other words, after a neutrophil has left the bloodstream and entered a tissue site, the neutrophil does not re-enter the blood. Once in tissue, they phagocytose microorganisms or necrotic tissue, release their granules, and die shortly thereafter. Neutrophils are part of the innate immune system. Histologically, tissues are considered inflamed when there are leukocytes present where they would not normally be found. Neutrophils within the alveolar spaces of the lung would be considered inflammation and is the classic appearance of bacterial pneumonia. In contrast, lymphocytes normally found within the colon, such as Peyers patches, would not typically be considered evidence of inflammation. Inflammation is NOT synonymous with infection. Although infections may cause acute inflammation, other initiating events may also trigger an acute inflammatory reaction. As an example, dermatitis is inflammation of the skin. This may be due to an infection, but also maybe to contact hypersensitivity, direct irritation, i.e. splinter, or an autoimmune reaction. Acute inflammation has four cardinal signs, Redness/Rubor, Swelling/Tumor, Heat/Calor, Pain/Dolor.
Analytic variables for optimal laboratory resulting:
Interference is when a substance interferes with the running or reading of a reaction. For example, assays that use optical transmittance for reading a reaction may be hindered by hemolyzed, icteric, or lipemic samples. Also immune assays can yield false results in patients who have endogenous heterophile antibodies (which is a rare occurrence). Heterophile antibodies are human antibodies directed against animal antibodies. Because many immune assays use antibodies generated in animals, heterophile antibodies can cause interference in these tests. Optimal instrument calibration i.e. just because a test is run on a machine doesn't mean it will always yield correct results. All instruments are subject to incorrect trends or a drift and need to be calibrated on an as needed or scheduled basis. Optimal instrument calibration is gauged by quality control (QC) which is discussed later. Difficulty of a case i.e. some qualitative tests may be deemed difficult to interpret either due to equivocal results, rarity of a case, multiple disease processes, etc. Post-analytic phase: The post-analytic phase starts when the laboratory result is generated by the LIS. The time it takes for this result to interface between the LIS and the EMR and the time it takes for the clinician to see this result is the post- analytic phase. Minimizing the post-analytic phase allows for timely intervention especially for critical alert values (CAV). Some laboratory values are deemed to be life-threatening and are designated as a CAV. CAV include laboratory results such as a potassium (K+) <2.8 or > 5.8, a hemoglobin < 7.0, a positive blood culture, and many others. CAV require a phone call from the laboratory to the ordering clinician within a certain time frame when the result is known. Turnaround time: The time it takes from specimen draw or specimen receipt in the lab to the laboratory result is the turnaround time (TAT). TAT vary by the test type and if there are any problems associated with specimen transport or the actual running of the test. Some tests are easier and faster to run than others. Also some tests are done on 24/7/365 whereas other tests are low volume and lower priority and hence batched i.e. hemoglobin HPLC are run at BMC twice a week, special coagulation tests are run once a week. Lastly some tests require a fast TAT such as blood gas which is usually available within 15-20 minutes of specimen receipt. This is in contrast to for example a molecular test for genetic counseling, which often does not require immediate analysis for patient management.
Vinblastine
Interferes w/ microtubule polymerization (blocks alpha and B tubules); messes up cell division
1. Specify the histological, molecular, and cellular alterations associated with repair in response to tissue injury
Introduction: When tissues are damaged, the body attempts to repair the injury. The initial response is inflammation to contain the injury and its agent. This is followed by repair, which consists of 2 elements: regeneration and fibrosis or fibroplasia. Regeneration involves the recovery of the original tissue by cell growth - proliferation, migration and then differentiation. For vital organs, especially, this is the ideal outcome of repair. In the case of a surgical wound this is referred to as healing by primary intention. The capacity of cells to regenerate themselves varies from readily for so-called labile cells such as epithelial surface cells to not at all for permanent cells such as neurons: • Labile Cells - Continuously dividing cells e.g. surface epithelia. • Stable Cells - Infrequently dividing cells, e.g. liver, smooth muscle • Permanent Cells - Rarely or non-dividing cells e.g. neurons, and skeletal muscle cells If regeneration is not possible, either because of the extent of the defect or limited regenerative capacity of the tissue, the next and, perhaps, last resort is to patch the defect with a scar. This patching process is called fibrosis or fibroplasia (or in the central nervous system, gliosis). In the context of surgical wound healing this "complicated" healing is referred to as healing by secondary intention. Stem Cells are of interest here because of their role in tissue homeostasis and potential future applications in the repair of injury in human tissues including lethal injury to permanent cells such as neurons and cardiac muscle fibers. Embryonic stem cells are derived from the developing blastocyst and are unequivocally pluripotential. Adult or tissue stem cells can be identified in numerous tissues including brain. They reside in special microenvironments called niches, composed of mesenchymal, endothelial and other cell types. They are known to have broad developmental plasticity and play a key role in tissue homeostasis. Recently scientists have shown that such cells, and indeed fully differentiated cells also, can be manipulated in vitro to acquire the pluripotential of embryonic stem cells.
MICROBIOME
Lecture 40: The Microbiome August 1, 2017 1 Normal Flora Microorganisms that are frequently found on, or in, the body of healthy persons; an "organ"? Outnumber human cells 10-fold? Maybe not... -Mostly bacteria, but fungi, viruses (phages and human), and parasites can be found; culturable vs. non-culturable "peacekeeping organisms", "pathobionts" Human Microbiome Project Rationale: determine "healthy" microbiome; is it different from microbiome in some diseases? Can restoring "healthy" microbiome treat diseases due to dysbiosis? Tracked 242 healthy men and women over 2 years; sequenced genetic material from 15-18 anatomic sites (e.g. skin, nose, mouth, gut). Results: No 2 microbiomes are alike Microbial diversity is great even in one person But there are a few "signature" bacteria found at specific body sites in most people, with similar functions, e.g. carbohydrate processing. 2 Normal Flora -Fetus develops in a "sterile" environment, but quickly becomes colonized during and after birth. Vaginal microbiome changes during pregnancy Flora differs in vaginal vs. C-section delivery; breast-feeding vs. formula 3 Taxonomic distribution of mo's in mother and baby 4 Nature Reviews Microbiology Vol 9, Jan. 2011 5 Nature Medicine Vol 22 Number 7, July 2016 How is the normal flora established? 6 From: Metro Boston 1 From: Bagg et al. 2006 8 Plaque Formation 2 From: Bagg et al. 2006 9 Formation of Dental Plaque From: Prescott et al. 2005 10 Commensal Microorganisms Opportunistic Pathogens Strict Pathogens Colonizing Microorganisms 11 Normal Flora -Exposure to microorganism may result in: a. transient colonization b. permanent colonization c. disease production -Normal flora varies with age, environment, immune status, diet, hormone levels, medications -The large intestine has the most bacteria; other popular sites: skin, URT, mouth, vagina, anterior parts of the urethra -Most normal flora bacteria are anaerobes. -Normal flora provide essential benefits to humans 12 Normal Flora 13 EMBO reports vol 7 no 7 2006 The Gut Microbiota Affects Drug Metabolism Science Vol 336 6/8/12 14 15 NEJM 375:24 12/15/16 Nat Med 22;10:1079 2016 16 Antibiotic depletion of microbiota is sufficient to predispose mice to allergic disease Nat Medicine vol 18, No 4, 2012 17 18 NEJM 375:24 12/15/16 Normal flora serves as a source of opportunistic infections Prescott, et al. Microbiology 6th ed. 2005 19 From: Prescott et al. 2005 How does the normal flora co-exist with the immune system? 20 The Immune System Controls the Microbiota... Science Vol 336 6/8/12 21 Ex. The immune system monitors and regulates intestinal bacteria 22 EMBO reports vol 7 no 7 2006 NEJM July 7, 2016 23 And commensals have mechanisms for suppressing the immune response against them... 24 EMBO reports vol 7 no 7 2006 And the Microbiota Influences the Immune System... The hygiene theory Science Vol 336 6/8/12 25 Location Conjunctiva Skin Nose Mouth Dental plaque Gingival crevices Throat Stomach Colon Vagina Urethra Medically Important Members of the Normal Flora Important Organisms1 Staphylococcus aureus & coag-neg Staph, Corynebacterium species Staphylococcus epidermidis S. aureus3 Viridans streptococci Streptococcus mutans Various anerobes, e.g. Bacteroides, Fusobacterium, streptococci, Actinomyces Viridans streptococci Bacteroides fragilis, E. coli Lactobacillus, E. coli3, group B streptococci3 Less Important Organisms2 Haemophilus spp. and Streptococcus spp. S. aureus, Corynebacterium, various streptococci, Pseudomonas aeruginosa, anaerobes (e.g. Propionibacterium acnes), yeasts (e.g. Candida albicans) S. epidermidis, Corynebacterium, various streptococci Various streptococci, Eikenella corrodens Prevotella intermedia, Porphyromonas gingivalis Various streptococci (including S. pyogenes & S. pneumoniae), Neisseria species, Haemophilus influenzae, S. epidermidis Moraxella Helicobacter pylori, Lactobacillus spp. and Streptococcus spp. Bifidobacterium, Eubacterium, Fusobacterium, Lactobacillus, various Gram-negative rods, Enterococcus faecalis, streptococci, Clostridium Various streptococci, various Gram-negative rods, B. fragilis, Corynebacterium, Candida spp. S. epidermidis, coag-neg Staph., Corynebacterium, various streptococci, 26 various Gram-negative rods, e.g. E. coli3 Normal Flora is not found in some sites Deep tissues and organs CSF Blood Body fluids Implications for specimen collection, lab tests, and interpretation of results... 27 From: Petersen, C. & J.L. Round (2014) Defining dysbiosis and its influence on host immunity and disease. Cellular Microbiology 16(7) 1024-1033 Diseases Associated with Dysbiosis? Obesity and metabolic syndromes Inflammatory bowel disease Irritable bowel syndrome Asthma Antibiotic-associated diseases Autoimmune and inflammatory diseases Colon cancer Non-alcoholic fatty liver disease Atopy Hypertension 29 Prebiotics, Probiotics, Synbiotics Probiotics: live microorganisms that, when administered in adequate amounts, confer a health benefit on the host. Prebiotics: selectively fermented ingredients that stimulate specific changes in the colonic microbiota that benefit the health of the host. Synbiotics: combinations of pre- and probiotics that are designed to have synergistic or additive effect benefitting the host 30 31 32 Mechanisms of action of probiotics FIGURE 1. Inhibition of enteric bacteria and enhancement of barrier function by probiotic bacteria. Schematic representation of the crosstalk between probiotic bacteria and the intestinal mucosa. Antimicrobial activities of probiotics include the (1) production of bacteriocins/defensins, (2) competitive inhibition with pathogenic bacteria, (3) inhibition of bacterial adherence or translocation, and (4) reduction of luminal pH. Probiotic bacteria can also enhance intestinal barrier function by (5) increasing mucus production. 33 (Inflamm Bowel Dis 2009;15:300 -310) Mechanisms of action of probiotics FIGURE 2. Modulation of mucosal immune response by probiotic bacteria. Pathogen-associated molecular patterns (PAMPs) derived from probiotic bacteria are recognized by pattern recognition receptors, such as Toll-like receptors (TLRs) on DC in the epithelium or lamina propria. Probiotic bacteria can shape the mucosal immune system toward a noninflammatory, tolerogenic pattern through the induction of T cells with regulatory properties. Probiotics can also downregulate Th1 response and inhibit the production of proinflammatory cytokines, IL-12, TNF-, and IFN- by DC. The predominant cytokine profile depends on the nature of the stimulus and the types of probiotic bacteria. The IL-23/IL-17-mediated inflammatory axis has recently been implicated in the pathogenesis of IBD but there remain gaps in our knowledge on how probiotics influence the 34 differentiation of Th17 cells. (Inflamm Bowel Dis 2009;15:300 -310) 35 Nature Reviews Microbiology Vol 9, Jan. 2011 Fecal matters 36 Volume17 number 2 | february 2011 Nature Medicine Fecal transplants??? 37 From: Improper Bostonian 8/5-18/15
describe the mucopolysaccharidosis: Hurler's syndrome
Lysosomal storage diseases - Mucopolysaccharidoses (MPS) results from deficiency of enzymes involved in the degradation of glycosaminoglycans (ground substance). Several clinical variants of MPS have been described (MPS I to VII). One of the better described variants is MPS I (Hurlers syndrome). Enzyme deficient: alpha-L-iduronidase Accumulated substrate: Heparan and dermatan sulfate Major organs affected: Liver, spleen, brain, heart, blood vessels. Histology: "balloon cells", MPS in phagocytes, endothelium, smooth muscle cells, neurons and fibroblasts, EM - lamellated structures in neurons (Zebra bodies). Clinical: common to all MPS are hepatosplenomegaly skeletal deformities, cardiac valvular lesions, coronary artery deposits, brain lesions. Myocardial infarction and cardiac decompensation are important causes of death. Prenatal diagnosis is possible.
describe the pathogenesis of LSD's
Lysosomes - membrane bound cytoplasmic organelles containing hydrolytic enzymes that break down complex macromolecules derived exogenously (heterophagy) or endogenously from the turnover of intracellular organelles (autophagy). The cells of the mononuclear phagocytic system are prominently involved in the lysosomal catabolism of macromolecules so organs rich in macrophages (histiocytes), i.e. spleen, lymph nodes, liver, are especially enlarged and/or impaired in LSD. Three major categories of macromolecules that accumulate in LSD's include: 1. Sphingolipids: - Sphingomyelin, cerebrosides and gangliosides. - Combinations of sphingosine (a long chain amino alcohol), esterified fatty acids and complex carbohydrates. - Particularly abundant in the membranes of brain and nerve tissues. 25-2 2. Mucopolysaccharides (Proteoglycans): - Comprise much of the ground substance of connective tissue (Heparan sulfate, dermatan sulfate, keratan sulfate and chondroitin sulfate).- Long linear polymers of substituted glucose and galactose. 3. Glycogen: - Large branched polysaccharide of glucose. - Main pathway for degradation is in the cytoplasm via phosphorylases, debranching enzymes, etc. Glycogen can also be degraded in lysosome (acid maltase) which, when defective, can lead to a LSD.
Provide the characteristics of a malignant tumor. Exceptions to the "oma" rule. Because certain terminology has become so ingrained in the medical literature there are certain "omas" that are not benign: lymphoma, melanoma, seminoma, mesothelioma, hepatoma.
Malignant neoplasms: There are two fundamental properties that define a tumor as malignant: a) invasion and destruction of adjacent tissues. b) spread to distant sites (metastasis) Malignant tumors are oftentimes called cancer (crab) because they adhere firmly to involved tissues. Cancers grow by progressive invasion and penetration of surrounding tissue thus, in general, cancers are not encapsulated. On clinical examination these tumors are poorly defined and tend to adhere to surrounding structures. Histologically malignant tumors are composed of cells exhibiting varying degrees of anaplasia (sometimes referred to as "atypia") and consequently varying degrees of differentiation (well, moderately, poorly differentiated). Depending on the aggressiveness of the tumor, mitoses may be prominent and, in particular, bizarre mitoses (tripolar, quadripolar, and circular) may be identified. Nomenclature: 1. Malignant tumors arising from mesenchymal tissue are called sarcomas. A malignant tumor of fibroblasts is a fibrosarcoma, of chondrocytes a chondrosarcoma; of smooth muscle a leiomyosarcoma etc. 2. Malignant tumors of epithelial cells are called carcinomas. Malignant tumors arising from squamous epithelium are called squamous cell carcinomas (or epidermoid carcinomas). Malignant tumors arising from glandular epithelium are called adenocarcinomas. Those malignant tumors arising from urothelium (transitional cells) are called transitional cell carcinomas (ureters, bladder). Some carcinomas arising in specific organs are identified by the parenchyma cell of origin i.e. hepatocellular carcinoma, renal cell carcinoma. Malignant tumors of germ cells are given unique designations i.e. seminoma, embryonal carcinoma, choriocarcinoma, yolk sac tumor etc.
Physical Agents - Type of Injury
Mechanical Trauma [21, 22] Trauma, with its associated death and disability, is a major public health problem. Unintentional injuries, including motor vehicle accidents, homicide, and suicide, are the leading causes of death for adolescents and adults under age 44 in the US. Mechanical injury occurs whenever a force of sufficient magnitude is applied to the body. The force can be accelerating or decelerating, blunt or sharp, accidental or deliberate. The effects of mechanical force will depend on the amount of kinetic energy the object possesses, as well as the portion of the body and organs injured. Soft tissues, bones and the head are the most significant sites of damage due to mechanical trauma. Soft tissue injury types (head & bone injuries are not included here): Abrasion (scraping or rubbing) is an injury that removes the superficial layer of the skin. Contusion (bruise from a blunt object) shows extravasation of blood into tissue. Laceration (tear or disruptive stretching from a blunt object) has intact bridging blood vessels. Incised wound (from a sharp object) has severed bridging blood vessels (in contrast to laceration). Puncture wound (pierced tissue from penetration of a long & narrow sharp object) is referred to as penetrating, or as perforating if an exit wound is also formed. Thermal Injury
Bethanechol (carbamoyl-B-methylcholine)
Muscarinic Agonist some selectivity for bladder; used to treat post-op urinary retention
Pilocarpine
Muscarinic Agonist some selectivity for salivary glands; used to treat xerostomia and glaucoma (contracts ciliary muscles, moves fluid)
ii. Medically important bacteria that cannot be seen in the Gram stain:
Mycobacteria (Ex. M. tuberculosis) Too much lipid in cell wall so dye cannot penetrate Acid-fast stain Treponema (Ex. Treponema pallidum) Too thin to see Dark-field microscopy or immunofluorescence Mycoplasma No cell wall; very small None Legionella pneumophila Usually intracellular Silver stain or immunofluorescence Chlamydiae Intracellular; very small Look for inclusion bodies in cytoplasm, but insensitive; Giemsa stain Rickettsiae Intracellular; very small Giemsa or other tissue stains or immunohistochemistry
Tubocurarine
Nicotinic Antagonist; muscle relaxant competitive inhibitor of ACh, non-depolarizing. 70% bound prevents muscule contraction; flaccid paralysis AChE inhibitors, reduce the destruction of endogenous ACh, used after surgery to speed recovery can sometimes cause histamine release and allergic reaction
OVERVIEW
OVERVIEW Classification of organisms into groups with similar features provides a means of predicting the nature of all the members of the group. However, the extreme diversity of bacteria makes it difficult to classify them into clear-cut categories and technological advances are changing the way we have classified many bacteria in the past, in addition to identifying new species. Understanding the similarities and differences between eukaryotic and prokaryotic cells is important because it provides the basis for developing effective and selective antibacterial agents. Understanding the structure of bacterial cells is critical for appreciating the variety of ways these organisms cause disease and has led to improved methods for clinical identification of bacteria.
How do opioids trigger vomiting center?
Opioid low dose stimulates chemocenter trigger zone, which stimulates the vomiting center Middle ear involvement (i.e. During movement) makes it worse (also stimulates vomiting center)
Opioid tolerance mechanisms
Opioid receptor changes: - phosphorylation & internalization - inc. MAP kinase, inc. adenylyl cyclase, inc. PLC Non-opioid receptor mechanisms - hyperalgesic effect (NMDA, NO) - neuroinflammation (immune responses)
1. define virulence, LD50 and ID50. 2. list and describe how host factors can increase susceptibility to infections and more severe outcomes of infection, including immunodeficiency/immune defects, certain pre- existing conditions, splenectomy, age, malnutrition, pregnancy, substance abuse, medications, genetic factors. 3. compareandcontrastthemajorfeaturesofacuteandchronicinfections. 4. describe the 4 typical stages of an infectious disease. 5. list the stages that occur during an effective bacterial infection and disease production. 6. describe several host defense mechanisms that bacteria must overcome in order to colonize. 7. list and describe how the following bacterial virulence factors or processes facilitate adherence, invasion of cells and tissues, and/or evasion of host immune defenses: IgA protease, coagulase, capsule, Protein A, antigenic variation, growth in biofilms intracellular growth, pili, collagenase, hyaluronidase, siderophores, type secretion systems. 8. explainhowbacteriacancausetissuedamageanddiseaseviainvasionand inflammation, toxin production, by-products of bacterial growth, and immunopathogenesis. 9. compare and contrast the major features of exotoxins and endotoxins; define "toxoid". 10.state whether or not immunity to re-infection occurs after a bacterial infection resolves.
Pathogenesis refers to the interaction of bacterial and host factors that leads to production of disease. There are specific steps involved in bacterial pathogenesis: to produce disease, bacteria must come into contact with a susceptible host, enter the host, overcome host defenses, colonize, and produce cell and tissue damage. It is important to remember: 1) Many, if not most, infections are subclinical-they do not produce disease. 2) The same disease may be produced by more than one bacterial species. 3) One bacterial species may produce a variety of diseases. 4) The outcome of an infection is determined by the interaction of the bacterium and the host. 5) Understanding the process of bacterial pathogenesis is critical for controlling the spread of infection, performing appropriate lab diagnostic tests, predicting disease outcomes, and developing effective treatments.
. Cell walls of Acid-fast bacteria a. Unlike Gram-positive and Gram-negative bacteria, Mycobacteria species have cell walls with a high concentration of lipids called mycolic acids, and cannot be Gram stained.
Peptidoglycan(alsocalledmurein,mucopeptide) a. "Peptides and sugars" b. Carbohydrate backbone composed of alternating N-acetylmuramic acid and N-acetylglucosamine molecules. A tetrapeptide consisting of both D- and L-amino acids is attached to each muramic acid molecule. The composition of the tetrapeptide differs among bacteria. 1. The amino acid, diaminopimelic acid is unique to bacterial cell walls. 2. The amino acid, D-alanine, is involved in the cross-links between tetrapeptides and in the action of penicillin. c. Protects the cell membrane d. Only present in bacterial cells; not in human cells—makes it a good target for antibacterial drugs. Ex. Beta lactams, e.g. penicillins and cephalosporins, interfere with peptidoglycan synthesis by inhibiting the transpeptidase that cross- links the 2 adjacent tetrapeptides. Vancomycin also inhibits this step by using a different mechanism (steric hindrance). e. Lysozyme cleaves the peptidoglycan backbone by breaking glycosyl bonds. Lysozyme is present in human tears, saliva and mucous and is a natural defense to bacterial infection. i. Lysozyme treatment weakens the cell wall, so that bacterial cells will be more susceptible to destruction, especially when they are in a solution with a different osmotic pressure as inside the bacterial cell. f. Peptidoglycan can activate the innate immune response by binding to pattern recognition receptors (PRRs) on host cells; e.g. Toll-like receptors. PRRs recognize "pathogen-associated molecular patterns" (PAMPs), like peptidoglycan, on foreign entities that enter the body. g. Peptidoglycan can act as an endotoxin with similar effects as LPS (see below), but it is much less potent.
Principles of Pharmacology and Therapeutics • Botanical preparations ("herbal medicine") - Complex mixtures of plant substances • "Small molecule" drugs (m.w. < 1000) - Racemic mixtures (e.g. D- and L- epinephrine) - Pure stereoisomers • Polypeptides & small proteins - Insulin (m.w. 6000) • Protein therapeutics (biologics) - Botulinum toxin A (m.w. 900,000) - Infliximab (IgG monoclonal antibody vs. TNF-; m.w. 144,000) • Nucleic acids - Mipomersen (antisense oligonucleotide for ApoB mRNA; m.w. 7500) Drug Names • Chemical name - Specifies chemical structure ( e.g. ethyl 12-fluoro- 8-methyl- 9-oxo- 2,4,8- triazatricyclo [8.4.0.02,6] tetradeca- 1(10),3,5,11,13- pentaene- 5-carboxylate ) • Code name - Chosen by manufacturer during drug development ( e.g. Ro 15-1788 ) • Proprietary name - Also referred to as brand or trade name - Chosen by manufacturer for marketing purposes ( e.g. Anexate®, Lanexat® ) • Official name - Assigned by US Adopted Name Council ( e.g. flumazenil ) - Also referred to as generic or nonproprietary name - Name used throughout DRx, including exams
Pharmacokinetics • The time course of drug absorption, distribution, and elimination • Factors that affect pharmacokinetics Principles of Pharmacokinetics Dose absorption distribution elimination EFFECT Cp 3 key pharmacologic phenomena that describe the time course of the drug in the body and the therapeutic response Biotransport: transport of drugs into and through cells • Passive diffusion - by passage through membrane - by filtration • Carrier-mediated transport • Receptor-mediated endocytosis Biotransport Passive Diffusion • First-order kinetic process - Rate dependent on concentration gradient • Cellular structure of membranes - Tight junctions - Lack of porosity • Chemical properties of drugs - Lipophilicity - Charge: Ionizable residues and pKa - Molecular weight Biotransport\Passive Diffusion Lipophilicity • Solubility in lipid relative to water • Measured by oil/water partition coefficient - Drug concentration in oil versus water Oil Water Biotransport\Passive Diffusion Impact of Ionizable Groups • Ionization markedly decreases lipophilicity and increases hydrophilicity • Drugs with fixed negative or positive charge do NOT diffuse through cell membrane - Example of quaternary ammonium compounds Biotransport\Passive Diffusion Impact of Ionizable Groups Neuromuscular Blocker Succinylcholine has a quaternary ammonium fixed positive charge Biotransport\Passive Diffusion Lipophilic Drugs with an Ionizable Group • Drugs with carboxylate group act as acids and become negatively charged (and nonlipophilic) as pH increases. • Drugs with amine group act as bases and become positively charged (and nonlipophilic) as pH decreases. • Only the uncharged, unionized form of a drug is lipophilic enough to diffuse through cell membranes Biotransport\Passive Diffusion Influence of pKa on Acid A and Base B AH A- + H+ BH+ B + H+ • • Weak acid is uncharged at low pH; as the pH increases it ionizes; gives up a H+ ion Weak base is ionized and charged in low pH; as pH increases it looses the H+ ion and becomes uncharged low pH high pH Biotransport\Passive Diffusion Lipophilic Drugs with an Ionizable Group Aspirin • weak acid (pKa 3.5) • at physiologic pH it gives up a H+ and becomes charged • pKa 3.5 < pH7.4 Biotransport\Passive Diffusion Lipophilic Drugs with an Ionizable Group • tertiary amine • weak base (pKa 8) • at physiologic pH it picks up a H+ and becomes charged • pKa 8 > pH 7.4 Lidocaine Molecular Weight TPA Biotransport • TPA(tissueplasminogen activator) is large molecule drug • Protein with 527 aa and MW of 70,000 • Administered parenterally • Doesn't travel across membranes • Stays in the plasma to lyse clots Molecular Weight • Chimeric monoclonal antibody (mAbs) MW 144,000 • Biologic agent (Protein therapeutic) • Administered parenterally Infliximab Biotransport (Fc) (Fab) Which drug most readily diffuses through cell membranes?Base at high pH Biotransport Filtration • Transport of small molecule drugs in bulk flow of aqueous fluid • Rate dependent on - hydrostatic pressure - molecular weight, size, charge, and binding to excluded macromolecules - tissue porosity • glomerular capillaries in kidney • choroid plexus in brain • sinusoids in liver Biotransport Convective transport • Important mechanism of transport of mAb from lymph or blood into tissue spaces • Depends on hydrostatic pressure gradient, fluid flow rate into the tissue, and on the sieving effect of paracellular pores • Sieving depends on size & shape of pores, and size, shape, & charge of antibody. Biotransport Carrier-mediated Transport • Saturable kinetics • Substrate competition • Stereospecificity • Tissue differences in expression of carriers Biotransport Drug Transporters • Organic anion transporter 1 (OAT1) • Solute carrier family member - SLC22A6 gene product • Organicanionicsubstrates • Probenecidsensitive • ABCtransporter P-glycoprotein 1 (Pgp), multidrug resistance protein (MDR 1) - ABCB1 gene product • Amphipathic,cationic and neutral substrates • Verapamilsensitive Biotransport Drug Transporters • MDR p-Glycoprotein • Actively transports many chemically different agents across membranes throughout the body. • Expression is upregulated by drugs causing resistance to many antitumor agents. • MDR is found on normal cells as well as tumor cells Biotransport Drug Transporter Localization • Intestinal mucosa • Hepatocyte - into bile • Proximal renal tubule - plasma into nephron lumen • Brain - Choroid Plexus - Vascular endothelium - back into plasma and away from brain Biotransport Receptor-mediated Endocytosis • Importance in selective tissue uptake • Rate dependent on receptor expression and membrane insertion • Saturable kinetics • Mechanism for some protein therapeutics (biologic agents) - monoclonal antibodies (mAbs) Biotransport Endocytosis of mAbs Receptor-meditated endocytosis: • specific interaction of the Fab binding domains of the antibody with target epitopes on the cell surfaces • results in target-mediated disposition of drug Fab with its pharmacological target Fluid-phase endocytosis: • nonspecific process driven by the Fc concentration of mAb on the extracellular side; does not require ligand binding to cell surface • responsible for mAb entering into endothelial cells and peripheral tissues. Principles of Pharmacokinetics DOSE absorption distribution Cp elimination EFFECT Absorption Kinetics • Time-course of transport from site of administration to systemic circulation • Characterization by - Absorption half-life - Percent dose absorbed (Bioavailability) Routes of Administration Routes of Administration Intravenous (iv) • 100% bioavailability • Fastest possible input rate • Rate dependent on technique of administration (IV bolus or IV infusion), not physiological process • Importance of sterility, lack of particulates, aqueous solubility of agent • Route for high MW, polar molecules Biologic agents (therapeutic proteins) Routes of Administration Enteral Administration Bioavailability Bioavailability (F) is the fraction of the dose absorbed into the systemic circulation. Bioavailability is influenced by: •GI absorption •Metabolism in GI tract and/or liver (first pass effect) Brenner and Stevens, Pharmacology 2nd ed (2006) Routes of Administration Oral (p.o.) • Absorption half-life affected by - Formulation of drug • Dissolution from solid - Gastric emptying time - Interactions with diet or other drugs in gastrointestinal lumen Routes of Administration Oral (p.o.) Bioavailability may be low due to: • Mucosa as barrier for drugs with high MW low lipophilicity carrier-mediated extrusion from mucosa back into GI lumen • First-pass effect lumenal, mucosal and/or hepatic biotransformation during absorption process Routes of Administration Subcutaneous (s.c.) & Intramuscular (i.m.) • Low MW lipophilic drugs into blood - Blood flow may affect absorption rate • High MW compounds into lymphatics - Improved bioavailability over oral route for polar and high MW drugs (proteins, mAb) - Uptake of high mw compounds into the lymphatics provides slow absorption rate • Delivery devices for sustained release Inhalation • Rapid absorption of gases and vapors due to - high pulmonary blood flow - low diffusional distance from alveolus to blood • Route for localized delivery of drugs with actions in pulmonary tissue - Nebulizers - Metered dose inhalers Routes of Administration Topical • Absorption through skin generally slow due to surface layers of dead, keratinized cells (stratum corneum) • Drugs with sufficient lipophilicity and potency may have systemic clinical efficacy upon topical application in transdermal patch - Avoids first-pass effect Principles of Pharmacokinetics DOSE absorption distribution Cp elimination EFFECT Distribution Kinetics • Rate and extent of distribution from vascular fluid to tissue space • Determinants of equilibration rate - Blood flow Distribution Kinetics Tissue Perfusion Rates (ml/min-100g tissue ) High Lung 400 Kidney 350 Liver 85 Brain 55 Intermediate/variable Skeletal muscle 5 Low Fat 3 Distribution Kinetics Determinants of equilibrium gradient -Tissue factors Vascular permeability Macromolecular binding in tissue Plasma protein binding P + D PD Dissolution of lipid-soluble drugs in adipose tissue -Physicochemical factors of drug mw, lipophilicity, affinity of carriers Distribution Kinetics Vascular permeability: The Blood-Brain Barrier • Tight junctions between vascular endothelial cells - exclusion of high MW, non-lipophilic drugs • Transporters which actively transport some drugs from endothelium back into plasma PROTEIN Albumin 1-Acid glycoprotein MW CONCENTRATION 67,000 500-700 mM 42,000 9-23 mM Distribution Kinetics Plasma Protein Binding Plasma protein binding P + D PD Drug Warfarin Codeine % Bound in plasma 99% 7% Distribution Kinetics Plasma Protein Binding Apparent Volume of Distribution (Vd) Vd is the volume of the body into which the drug appears to have distributed Drugs will distribute into their apparent volume of distribution dependent on their chemical characteristics Vd governs the concentration of drug in the plasma (Cp) The amount of drug in the body can be related to it's plasma concentration by a proportionality constant that reflects the apparent fluid volume into which the drug distributes (Vd) Apparent Volume of Distribution (Vd) Plasma Concentration = Amount in Body (Cp) Volume Initial Plasma Concentration = Dose (g) (C0) Vd (liters) Vd does not change with dose Distribution Kinetics Apparent Volume of Distribution Fluid compartments of 70 kg subject in liters and % body weight: plasma 3-4L (4%) extracellular 12-14L (17%) total body water 40-42L (58%) Whalen, Lippincott's Illustrated reviews: Pharmacology 6th ed (2015) Fluid Compartments 70-kg Adult Compartment Liters %BW plasma 3 4 extracellular water 12 17 total body water 41 58 Indicator 131I-albumin sucrose D2O Distribution Kinetics Apparent volume of distribution (Vd) depends on the chemical characteristics of the drug: • High MW such as therapeutic proteins - Vd ~ plasma volume, 4% BW • Small MW and polar - Vd ~ extracellular fluid volume, 17% BW • Small MW and lipophilic - Vd ~ total body water or even larger if highly lipophilic, > 58% Which drug is most likely to have a Vd greater than the volume of total body water? Highly lipophilic drug Vd decreases in obesity Elimination Kinetics • Rate and extent of elimination by excretion or biotransformation • Quantitation by total clearance (ClT) - Volume of plasma cleared of compound per unit time by all routes and mechanisms - Expressed as ml/min or ml/hr Elimination Kinetics Clearance depends on organ plasma flow Clorgan = (plasma flow) (Cpa-Cpv) Cparterial Cpa Cpvenous Organ Clearance Elimination Kinetics Total Clearance ClT determines the elimination rate of a drug from the body (dA / dt) (ClT)(Cp)= dA/dt Note: A is amount of drug in the body Elimination Kinetics Total Clearance • Is sum of renal and nonrenal clearances ClT = ClR + ClNR • Renal refers to urinary excretion of unchanged drug • Nonrenal refers to all other routes and mechanisms Elimination Kinetics Monoclonal Antibodies (mAb) Mechanisms of Elimination • Nonspecific endocytosis • Degradation by proteolysis • Target-mediated clearance • FcRn-mediated clearance • FcgR-mediated clearance • Formation of immune complexes (IC) Elimination Kinetics\ mAbs Proteolytic degradation: • mAbs undergo intracellular lysosomal proteolytic degradation • May occur widely in the body or limited to specific organs (liver, kidneys, spleen) • Liver may metabolize mAb by the same catabolic pathways as endogenous proteins • Kidneys may metabolize biologics small enough (<60kDa) to undergo glomerular filtration • The reticuloendothelial system (RES) predominantly phagocytes (monocytes, macrophages) in the liver, spleen, and lymph nodes eliminates biologics, and endogenous IgG molecules Elimination Kinetics\ mAbs Fab-mediated elimination • The specific interaction between the Fab region of the antibody and target epitopes on cell surfaces Fab • A saturable, target-mediated clearance pathway • mAb enters the target cell by receptor-mediated endocytosis and undergoes intracellular catabolism Fc Elimination Kinetics\ mAbs Fc-mediated elimination • A nonspecific elimination pathway for both endogenous IgGs and therapeutic mAbs Fc Fab • Involves either FcRn or Fcγ receptors. Elimination Kinetics\ mAbs FcRn-mediated elimination/ recycling • FcRn, Brambell receptor, binds the Fc domain of mAb • A FcRn-mAb complex forms due to high affinity of FcRn for mAb in the acid environment of the early endosome. • A large fraction of the endosomes are not delivered to the lysosome but are sorted to the cell surface for fusion with the cell membrane. • Upon fusion, the IgG-FcRn complex dissociates in the physiological pH and free IgG is released back into extracellular fluid. Elimination Kinetics\ mAbs FcRn-mediated elimination/ recycling • FcRn is expressed in a wide variety of cells • FcRn-mediated recycling results in the long elimination half-life of IgG and many mAbs (3 weeks) Elimination Kinetics\ mAbs Fcg-mediated elimination • Many cell types (monocytes, macrophages, dendritic cells) express Fc receptors that bind to the Fc domain of biologic agents (mAbs and fusion proteins) • Biologic agents are internalized and degraded by lysosomes in RES • FcgR binding may also be responsible for the elimination of mAb-antigen immune complexes (IC) or cells opsonized by the mAb. • The exact mechanism of action of FcgRs in antibody clearance is not fully understood Elimination Kinetics\ mAbs Formation of immune complexes (IC) • Administration of an exogenous protein therapeutic agent (mAb), often triggers an immune response resulting in generation of endogenous antibodies directed against the protein drug (antidrug antibody; ADA). • The biologic-ADA immune complexes (ICs) are then elimination via the RES Elimination Kinetics\Total Clearance (small molecules) Parent Compound ClR ClNR Metabolite Excretion ClR = renal clearance Excretion Further metabolism ClNR = nonrenal clearance (hepatic) Elimination Kinetics Nonrenal Clearance • Excretion of unchanged drug - Lungs (if high vapor pressure) - Bile • Biotransformation - Phase I oxidation, reduction, hydrolysis - Phase II conjugations Elimination Kinetics Significance of Biotransformation Prodrug Metabolite 1 (inactive) Active Drug Metabolite 2 Metabolite 3 (active) (toxic) Elimination Kinetics Kinetics of Biotransformation • Enzymatic reactions that obey Michaelis-Menton kinetics • Generally therapeutic levels << Km - FIRST ORDER kinetics - Rate of biotransformation proportional to concentration - Described by a half-life, t1/2 Elimination Kinetics\ Biotransformation Exceptions to First-Order Kinetics • Drugs where therapeutic levels >> Km - Ethanol - Aspirin • Drugs where overdose levels >> Km - Acetaminophen Elimination Kinetics\ Biotransformation Causes of Patient Variability in Clearance by Biotransformation: • Dietary and drug interactions - Inhibition: substrate competition, suicide inhibition • Grapefruit juice - Induction: promoters of enzyme expression • Cigarette smoke • Disease - Cytokine-induced inhibition of hepatic enzyme synthesis - Reduction in hepatic blood flow Elimination Kinetics\ Biotransformation Causes of Patient Variability in Clearance by Biotransformation: • Genetic polymorphisms in enzymes of biotransformation - Generally result in prolonged half-life - Frequency depends on enzyme and ethnicity • Examples - CYP450s - N-acetyltransferase - pseudocholinesterase Elimination Kinetics\ Biotransformation Pathways of Biotransformation Drug phase 1 Metabolite phase 2 Conjugated Metabolite (usually inactive & more polar than parent compound) Elimination Kinetics\ Biotransformation Phase 1 Cytochrome P450 Enzymes • Heme-containing • Imbedded in membrane of smooth endoplasmic reticulum (microsomes) • Highest activity in liver • Catalyze addition of molecular oxygen Elimination Kinetics\ Biotransformation Phase 1 Cytochrome P450 Enzymes • About 17 human genes • 3A4 and 2D6 important for many drugs • Isozymes differ in substrate specificity, inducers, and inhibitors • Inducers and inhibitors include drugs, herbal medicines, and environmental chemicals Elimination Kinetics\ Biotransformation Phase II Conjugating Moieties • Glucuronic Acid • Sulfate • Methyl Groups • Glutathione • Acetyl Groups • Glycine Elimination Kinetics\ Biotransformation Sites of Morphine Biotransformation Elimination Kinetics Renal Clearance • Volume of plasma cleared by excretion unchanged into urine • Mechanisms - Glomerular filtration - Proximal tubular carrier-mediated secretion - Passive reabsorption Renal Clearance Elimination Kinetics\Renal Clearance Glomerular Filtration • 20 % renal blood flow filtered • Protein-bound drugs not filtered Elimination Kinetics\Renal Clearance Proximal Tubule Secretion • • • • • Organic anion transporter (oatp) for acid drugs Organic cation transporter for basic drugs Competition between 2 acid drugs for organic anion transporter Competition between 2 basic drugs for organic cation transporter Protein binding does not affect secretion Elimination Kinetics\Renal Clearance Distal Tubule Reabsorption • Passive reabsorption of lipid-soluble, unionized drug • % Ionization depends on urine pH and drug pKa • Acid drug in alkaline urine has increased excretion • Basic drug in acidic urine has increased excretion Elimination Kinetics\Renal Clearance Distal Tubule Reabsorption: % Ionization Compartment in which the drug is more ionized will contain a greater concentration of drug (trapping) Figure shows a basic drug trapped in an acid environment Katzung et al., Basic and Clinical Pharmacology 11th ed (2009) Elimination Kinetics\Renal Clearance Determination of Renal Clearance (ClR) ClR = Urinary excretion rate Cp Amt excreted during collection interval Interval length ClR = ----------------------------------------------------- Cp at midpoint of interval Elimination Kinetics\Renal Clearance Relationship of ClR to Mechanism of Renal Excretion ClR ml/min/70 kg ------------------------------ 0-120 120 (GFR) 120-640(RPF) glomerularfiltration,tubular secretion, no net reabsorption Mechanism -------------------------------------------------------------- exclusion from filtration and/or extensive reabsorption glomerular filtration and no reabsorption Which is most likely to have a renal clearance > 120 ml/min in a 70 kg man? Acidicdrugwith affinity for oatp, high urine pH Elimination Kinetics\Renal Clearance Causes of Patient Variability in ClR • Proportional to body weight 0.7 • Decreases with age - Linear decline in creatinine Cl to 50% by age 90 • Altered by drug interactions - Reduced by carrier competition - Affected by pH if ionizable drug • Reduced by renal disease
2. Analyze the nature of stem cells and their roles in tissue repair and regeneration
Physiologic Role of Adult or Tissue Stem Cells in Tissue Homeostasis In addition to bone marrow cells that may migrate to various tissues after injury, adult stem cells reside permanently in most organs. In the liver they are called ovalocytes and are located in the ducts of Hering. They become activated following fulminant hepatic failure and in chronic liver disease where hepatocyte regeneration is slowed or inhibited. In skeletal muscle, stem cells called satellite cells have the capacity to regenerate. Injured epithelial surfaces renew themselves in 3 interdependent ways: (1) increasing the number of rapidly dividing stem cells, called transit amplifying cells. These cells give rise in turn to cells with restricted developmental potential known as progenitor cells ; (2) expanding the number of cells in the replicating compartment and (3) decreasing the replication time. Healing of tissue defects is usually by a combination of regeneration and fibroplasia. The relative contribution of each process is determined not only by the nature and extent of the injured tissues, but also by the character and persistence of the injury and by systemic factors. In the case of surgical wounds, for example, local factors that retard healing include impaired blood supply, denervation, infection, foreign body or necrotic tissue in the wound and mechanical stress. Systemic factors that adversely affect healing include diabetes, malnutrition, steroids, uremia, hypoxia, vitamin C deficiency and malignant disease. Many clinically important disease states arise when injured vital tissues are ultimately replaced by fibrous tissue as indicated by the following examples:
I. Eukaryotes vs. Prokaryotes
Property Prokaryotic. Bacterial Cells vs. Eukaryotic Human Cells DNA within a nuclear membrane No Yes Number of chromosomes 1 More than 1 Mechanism of Replication Binary Fission Mitosis Presence of organelles, e.g. Golgi, mitochondria, lysosomes, endoplasmic reticulum No Yes Size of Ribosome 70S 80S Site of respiratory electron transport Cytoplasmic membrane Mitochondria Cell wall containing peptidoglycan Yes (except Mycoplasma) No Cell membrane containing sterols No (except Mycoplasma) Yes
Cardiovascular use of aspirin
Prophylactically to decrease the risk of thromboembolic disorders such as transient ischemic attacks and MI (cox products affect platelet aggregation and TPR) "Baby aspirin once/day"
How do psyllium (Plantago ovata), walnuts, and plant sterols work?
Psyllium - dec. enterohepatic circulation of cholesterol Walnuts - dec. LDL 8-16% Plant sterols (beta-sitosterol) and stands - prevent incorporation of cholesterol into micelles - dec. LDL 5-17% - impact on CAD controversial - marketed in spreads (Benechol) and supplements Maybeee an effect if patient takes all of these together; alone = probably minimal effects
Quality Control and Quality Assurance in the Laboratory
Quality control (QC) is a standard step of running designated QC reagents to make sure that a test (whether completely automated, semi-automated, or manual) is generating correct or reasonably accurate results. QC optimizes the analytic phase of laboratory testing. Manufacturers sell QC reagents which have a known range for an acceptable result. The types of QC reagent depends on the test i.e. a white blood cell count (WBC) needs a low, normal, and high QC; whereas a partial thromboplastin time (PTT) needs a normal and high QC; versus a malaria antigen test needs a negative and positive QC. For instance if a normal QC reagent for platelet count is between 250-350 K, and the result ran on your instrument is 300 K, your QC is acceptable and patient samples can be run. If your QC reagent gave a result of 200 K, your QC has failed. When any QC has failed for a given test, then no patient samples can be run for that particular test until troubleshooting has occurred and a repeat QC is acceptable. If QC repeatedly fails then additional troubleshooting must occur including examination of reagents, examining technologist performance of a test, or recalibrating an instrument. For most tests, QC is run at the beginning of every shift (3 times a day). For low volume or batched tests, QC is run before each run. In addition to a shift or daily operations, QC can also be looked at as an overall trend to make sure there is no systemic bias or drift in results. For instance a Levey- Jennings plot is a graphical representation of QC results around a mean over time. Westgard rules are used for interpreting a Levey-Jennings plot and include many advisory principles such as: 13s rule: Reject a QC result if it is greater than 3 standard deviations (SD) from the mean. 22s rule: Reject a QC result if two consecutive QC results are greater than 2 SD from the mean on one side of the mean. R4s rule: Reject a QC result if two consecutive QC results are greater than 4 SD spanning or on opposite sides of the mean. 41s rule: Reject a QC result if 4 consecutive results are greater than 1 SD on one side of the mean. 8x: Reject a QC result if 8 consecutive values are all on one side of the mean. Quality assurance (QA) is a systematic approach overseen by the pathologist / medical director and technical supervisor to improve laboratory function including pre-analytic, analytic, and post-analytic variables. QA can be achieved globally as well as monitoring performance in proficiency surveys and in the form of QA projects. Proficiency surveys are standardized samples sent to laboratories by a central testing agency (College of American Pathologists or CAP), from which individual laboratory test results are compiled and statistics are generated which can be used to compare an individual lab to the group. As for QA projects, many aim at improving TAT but also includes things such as proper labeling of specimens, minimizing corrected reports, minimizing contamination rates (i.e. culture), expeditious reporting of CAV, etc.
More info for blood tests
Quality of the specimen i.e. minimizing hemolysis (larger gauge needles minimize hemolysis), optimal anticoagulation (lavender, blue, pink, and green top tubes need to be inverted a minimum amount of 5 times to ensure adequate distribution of the anticoagulant; also blue top tubes require the right amount of blood because the ratio of blood to anticoagulant additive is important for coagulation testing, this is achieved by allowing the vacuum to be fully exhausted before taking the tube off the needle), sufficiency of sample (generally more is better especially for microbiology tests i.e. instead of sending a swab send an aspirate or tissue), not collecting blood downstream on an infusion site which may cause erroneous results due to dilution or infusion contamination, collecting blood for coagulation testing that is free of line anticoagulants (flushing a central line that is being kept open with heparin), etc. Order of specimen draw i.e. when collecting multiple specimens, tubes with additives should be drawn last because the additive may splash, contaminate the needle and following tubes. Even small amounts of additive carried to the next tube could cause erroneous results. The correct order of a draw would start off with blood cultures, then red top, then blue top, and lastly any other additive tubes. Minimizing the time between specimen collection and receipt is important.
Which of the following is a valid conclusion, based on the information in Table 3?
Randomization was successful, since other risk factors were evenly distributed among the two comparison groups. Randomization is carried out with the intent of equal distribution of all other factors (possible confounding factors) among the comparison groups. This provides control for both known and unknown confounders. Randomized trials usually include an initial table that compares the characteristics of the subjects at baseline, i.e. after randomization. If a large enough sample was selected and randomization was successful, the groups should be very similar with respect to baseline characteristics, and this offers reassurance that randomization successfully distributed all factors evenly. However, it is possible that randomization is done correctly but the groups, due to random variation, are imbalanced in some way.
1. describe the general function of virulence factor genes and how their expression is regulated. 2. explain the advantage of organizing genes involved in similar functions into an operon under the control of a single operator. 3. define "pathogenicity island" and give an example. 4. list and describe the 4 major sources of DNA that may be transferred between bacterial cells. 5. explain how bacterial DNA can be transferred from one bacterial cell to another by: conjugation, specialized and generalized transduction, and transformation. 6. compare/contrast the lytic vs. lysogenic life cycle in bacteriophage 7. explain the role that specialized transducing phage play in the pathogenesis of bacteria causing diphtheria and cholera. 8. describe transposons and how they can alter bacterial gene expression. 9. explain the role of plasmids in transferring antibiotic resistance genes to bacteria. 10. discuss how the overuse/misuse of antibiotics contributes to increased prevalence of antibiotic-resistant bacteria.
Remember that bacteria are haploid; i.e. they have a single chromosome composed of DNA that is not found in a nucleus, but in the cytoplasm of the cell. The relatively small size of the bacterial genome and its close proximity to ribosomes gives bacteria the ability to replicate, mutate, and modify gene expression quickly in response to changes in their environment. In addition, bacteria often have extrachromosomal genetic elements, e.g. plasmids, transposons, and bacteriophages that contain additional genetic information and can be rapidly transferred between bacterial cells. These extrachromosomal genetic elements often contain genes encoding virulence factors, like toxins or proteins that mediate antibiotic resistance, and have played a crucial role in the evolution of antibiotic-resistant bacteria. The increase in bacteria resistant to multiple antibiotics is largely the result of the over- and misuse of antibiotics in animals and humans, which provides strong selective pressure for growth of these bacteria. The increase in bacteria resistant to currently available anti-bacterial agents and the scarcity of new agents in development is putting pressure on us to more strictly regulate the use of antibiotics and to be more creative in devising alternative strategies to prevent and treat bacterial infections.
Prevalence: Disease / (Disease + No Disease)
Sensitivity: How good an abnormal test detects a disease process. Sensitivity = TP / All Real Positives (TP + FN) Specificity: How good a normal test result detects a normal process. Specificity = TN / All Real Negatives (TN + FP) Positive Predictive Value (PPV): The probability that a positive test result predicts that the patient has disease. PPV = TP / All Tested Positives (TP + FP) Negative Predictive Value (NPV): The probability that a negative test result predicts that the patient does not have disease. NPV = TN / All Tested Negatives (TN + FN) Detecting disease and predicting disease are two different things. In the ideal world a test would have close to 100% sensitivity, specificity, PPV, and NPV. In the real world this is not the case. Usually improvements in sensitivity causes specificity to suffer and vice versa. In addition for some rare diseases, a low prevalence complicates matters. A receiver-operating characteristic (ROC) curve, plots the true positive rate (sensitivity) vs the false positive rate (1 - specificity) and is a graphical representation of finding the best cutoff between disease and no disease where sensitivity and specificity are maximized. Reference Range: A reference range has to be created for every test that is performed using your patient demographics. A reference range includes values within 2 SD of the mean or 95% of normal (non-diseased) patient lab results. So by definition, 5% of normal patients have test results outside the reference range. Rarely published reference ranges are used for low volume tests such as special coagulation studies as well as the pediatric age population since obtaining normal samples from these patients is controversial. Physiologic variables also effect reference range including patient age (pediatric population has different reference ranges compared to adults and even have different subset reference ranges such as those for neonates, infants, adolescents, and teenagers), gender (some lab results are different for men and women), seasonal change (i.e. vitamin D levels are higher in the summer than the winter), and diurnal variation (i.e. cortisol is higher in the morning and lower in the afternoon and evening). Linearity: The reportable range for a given test that a laboratory feels comfortable in reporting. Usually the manufacturer will recommend a particular reportable range. However the laboratory should also have a sense of what kind of range their instrument reports is accurate. This is why for some results there will be a comment of "greater than __" or "less than __".
3. Identify the difference between a transudate and an exudate, as well as the different types of exudates.
Step 2. Increased Vascular Permeability. Swelling, i.e. "tumor", is usually present to some degree in acute inflammation. A portion of the swelling results from the leakage of proteins from the plasma into the tissue interstitium. This leakage is not hemorrhage since erythrocytes do not escape. Leakage associated with the inflammatory response occurs in the microcirculation, mainly in the post-capillary venules and does not occur across larger arterioles, arteries or veins. The initial leakage takes place in venules, specifically between endothelial cells, which have retracted to expose openings to allow the escape of plasma proteins. Most of the mediators which cause hyperemia listed in step 1 also increased vascular permeability. Transudate and Exudate. A transudate has a specific gravity < 1.015 while an exudate has a specific gravity > 1.015. The presence of a transudate implies that the endothelial barrier to the passage of plasma proteins is generally intact. Transudates occur normally, to a small degree, across capillary beds. Starling's principle describes the forces regulating fluid flow across a capillary wall. Specifically, the hydrostatic and oncotic pressures of the blood and tissue result in an initial outward fluid flow from the blood vessel. This fluid (transudate) is reabsorbed on the venous side of the capillary bed or via the lymphatics. During inflammation, gaps between endothelial cells result in increased leakage of plasma proteins into the tissue. Definitions of different types of transudates and exudates: •Edema refers to the accumulation of fluid within the interstitium of tissues. It can be either a transudate or an exudate. Patients with edema are described as being "wet" because they have accumulated excess fluid. •An effusion is an accumulation of fluid in a sealed body cavity, such as the pericardial sac or between the parietal and visceral pulmonary pleura. An effusion can be directly aspirated through a needle or catheter, whereas edema cannot • Serous exudate contains few cells and resembles serum from the blood (i.e. more clear than cloudy). Its presence suggests a rather mild type of vascular injury • Purulent exudate implies a large concentration of neutrophils usually due to bacteria that attract neutrophils. This exudate has a cloudy appearance due to numerous cells. • Hemorrhagic exudate is one that contains red blood cells, due to capillary damage. •A fibrinous exudate is typically seen on serosal surfaces (pericardium, pleura) during an inflammatory response. A white layer of fibrin can potentially be several millimeters thick which occurs as a result of polymerization of plasma fibrin on the serosal surface.
S Qs
Study Questions 1. What are some examples of bacterial virulence factors and how do they enhance the pathogenicity of the bacterium expressing them? 2. Why does it seem like a good idea to regulate the expression of virulence genes, instead of just expressing them all of the time? 3. What is an operon and how does it regulate expression of bacterial genes? 4. What is a pathogenicity island? Can you give an example? 5. What is the difference between a plasmid and a transposon? 38-5 6. Draw a diagram and explain how plasmid DNA is transferred from one bacterial cell to another one by conjugation? What gene products are required? 7. What is the difference between lysogenic bacteriophage and lytic bacteriophage? 8. Draw a diagram (use colored pens or pencils!) and explain how bacterial DNA is transferred from one bacterial cell to another one by specialized transduction. Now add generalized transduction. 9. Draw a diagram and explain how bacterial DNA can be transferred from one bacterial cell to another one by transformation. 10. What is the difference between homologous recombination and nonhomologous recombination? Give one example of each from the processes of bacterial DNA transfer discussed in this lecture.
Describe the significance of tumor grade
Summary: The responsibility of the surgical pathologists in the evaluation of a patient with an abnormal growth is to: a) determine if the growth is a neoplasm b) If it is a neoplasm. Using histologic criteria decide on the cell of origin (epithelial, mesenchymal) c) Determine whether the neoplasm is benign or malignant d) If malignant, determine the grade of the tumor e) Determine the stage of the tumor if the specimen is appropriate to do so This information is then clearly communicated to the clinician coordinating the patient's care so that the most appropriate surgical approach and/or treatment modality is administered to maximally benefit the patient.
5. List the principle systemic effects of inflammation.
Systemic Effects of Acute Inflammation Fever. Fever is caused by a collection of substances collectively called "pyrogens." Bacteria can induce the production of pyrogens by the host. The major sources of endogenous pyrogens are macrophage-derived cytokines, notably interleukin-1 (IL-1), IL-6, and tumor necrosis factor-alpha (TNF-alpha). Macrophages release these cytokines after coming into contact with activating stimuli, such as bacteria, or after exposure to activating cytokines. These cytokines stimulate prostaglandin synthesis in the hypothalamic thermoregulatory centers, thus altering the "thermostat" controlling body temperature. Leukocytosis. This means an increased number of leukocytes in the peripheral blood. During acute inflammation, the number of circulating neutrophils typically increases. Additionally, increased number of immature forms of neutrophils appear. The neutrophilia (increased number of circulating neutrophils) is caused by colony stimulating factors. Tachycardia. During acute inflammation the heart rate will typically increase. Tachypnea. In a similar manner, the respiratory rate will increase. Acute phase reactants. These will be discussed in chronic inflammation. Benefits of acute inflammation. Acute inflammation must provide some survival advantage to the host given the potential deleterious consequences of inflammation. As stated at the beginning, the purpose of acute inflammation is to remove invading pathogens or clear necrotic tissue. This is accomplished through a number of different processes.
Describe the gross and microscopic features of tumors derived from epithelial and mesenchymal tissues and know the nomenclature for them.
The grade of a tumor is based on the degree of anaplasia (or degree of differentiation) of the neoplastic cells. Most grading systems classify tumors into three grades of increasing degrees of malignancy. For adenocarcinomas this not only includes the cytologic features of individual cells, it also relies on the ability of the neoplastic cells to form glands. For squamous cell carcinomas, it is the ability to form keratin (pearls). Well differentiated (grade I) tumors closely resemble the parent cell of origin and are considered less aggressive in their behavior. Poorly differentiated (grade 3) tumors depart from normal and usually are aggressive in their behavior. Moderately differentiated (grade 2) tumors exhibits features somewhere between well and poorly differentiated tumors.
ou should be able to: 1. explain how bacteria reproduce and the potential effects of a short vs. a long generation time on the production of disease. 2. compare and contrast features of bacterial growth in suspension, on a solid surface, and in a biofilm and how each of these different forms of growth relates to disease production or laboratory diagnostic procedures. 3. describe how a bacterial growth curve is generated, what it looks like, and the 4 major phases. 4. list the minimal growth requirements for bacteria and explain how these requirements can affect classification and choice of lab tests. 5. define: obligate aerobe, obligate anaerobe, and facultative anaerobe. 6. describethefunctionsofcatalaseandsuperoxidedismutase. 7. define fermentation and explain its importance in lab diagnostic tests. 8. state whether facultative anaerobes grow faster under aerobic or anaerobic conditions and explain why. 9. describe the general way in which bacterial surface structures are synthesized and assembled. 10.describe the basic steps in peptidoglycan synthesis and identify which steps are inhibited by antibiotics. 11.compare and contrast how penicillin vs. vancomycin inhibit synthesis of peptidoglycan.
The growth requirements and types of growth exhibited by pathogenic bacteria affect the way in which they produce disease, for example how quickly and where in the human body. It is important to know that specific bacteria have different growth requirements so that specimens are collected, processed, and cultured appropriately. Understanding bacterial growth, metabolism and biosynthetic processes has also been critical for developing effective antibacterial agents.
What do you predict would happen if both norepinephrine and Alpha were administered concurrently to the same patient? Explain your answer.
The vasoconstriction produced by the combination of norepinephrine plus alpha may be either greater or less than that produced by norepinephrine alone. At concentrations of norepinephrine that elicit a response less than the maximum for alpha, adding alpha will increase vasoconstriction. At high doses of norepinephrine that produce vasoconstriction above the maximum for alpha, adding alpha will reduce vasoconstriction. The vasoconstriction produced by norepinephrine plus alpha will never be less than that produced by alpha alone
• Explain the relationship between cyclooxygenase inhibition and the pharmacologic effects of aspirin-like drugs.
Therapeutic and many side effects of acetaminophen and NSAIDs result from inhibition of constitutive and inducible cyclooxygenases (COX-1 and COX-2, respectively). These drugs have a negligible effect on lipoxygenase and other enzymes in the arachidonic acid cascade. COX-2 is induced by cytokines, growth factors, and tumor promoters and thus is relevant especially to inflammation and cancer. Site-directed mutagenesis and x-ray crystallography provide considerable evidence about the structure-activity relationships for COX- 1 vs COX-2 selectivity. Aspirin is the only drug in this class that acetylates at the active site and causes irreversible inhibition. An increasing body of evidence points to inhibition of constitutively expressed COX-2 in the dorsal horn of the spinal cord as a component of the analgesic effect of these drugs. The COX-2-selective inhibitors, such as celecoxib, have decreased risk of gastrointestinal side effects; the maximum analgesic/anti-inflammatory efficacy, however, appears comparable to the older drugs. These discoveries are consistent with the hypothesis that gastric side effects of the older, nonselective drugs are attributable to COX-1 inhibition and the therapeutic effects to COX-2 inhibition. COX-2 inhibition of prostacyclin production in the vascular endothelium may explain the cardiovascular toxicity of the highly selective COX-2 inhibitors, such as rofecoxib (VIOXX), which led to its withdrawal from the market in 2005. The relatively weak cyclooxygenase inhibitory activity of acetaminophen compared to salicylates, despite its comparable analgesic potency and efficacy, has not been explained. Although the mechanism of action of acetaminophen is purported to result from COX inhibition, this drug does not have anti-inflammatory activity, lacks many of the side effects of the NSAIDs, and causes centrilobular hepatic necrosis as its major toxicity. This dose-dependent pathology is caused by a minor metabolite, generated by CYP450-mediated oxidation and inactivated by hepatic glutathione conjugation. Limited evidence suggests that relatively high concentrations of sodium salicylate (the major metabolite of aspirin) may inhibit the activation of NF-, the transcription factor that promotes the expression of certain inflammatory mediators, and may decrease the expression of COX-1 and COX-2. This observation is consistent with the higher ED50 for its anti-inflammatory effect as compared to its analgesic and antipyretic effect. Analgesia These drugs relieve pain of mild to moderate intensity without changes in other mental functions, but have a limited maximum effect. Severe pain is not relieved by a larger dose once the maximum recommended dose is taken, but requires use of another class of analgesic such as an opioid. The primary mechanism appears to be inhibition of the synthesis of prostaglandin E in the periphery with limited evidence of a CNS effect. These drugs are especially useful in treating headache, dysmenorrhea and pain originating from joints, skeletal muscle, and dental procedures Antipyresis Acetaminophen and NSAIDs reduce body temperature if fever is present, but not if temperature is normal. They act on hypothalamic nuclei that regulate the production and loss of body heat. Increased heat loss results from increased peripheral blood flow and increased sweating; the mechanism is inhibition of prostaglandin E synthesis in the hypothalamic region induced by endogenous pyrogens, such as interleukin-1, TNF and interferon-. The ED50 for antipyresis and analgesia are about the same for salicylates and acetaminophen. Aspirin and other salicylates should be avoided in children with influenza or varicella because of an association with Reye's syndrome. This potentially fatal encephalopathy has dramatically decreased in incidence since the association was determined, and pediatric use shifted away from salicylates to acetaminophen. Anti-Inflammatory Effect NSAIDs reduce the inflammatory response to mechanical, chemical or immunological stimuli; the mechanism is believed to be primarily inhibition of COX-2. These drugs are useful in treating diseases such as acute rheumatic fever and rheumatoid arthritis, where they may cause symptomatic relief. However, there are limits to their efficacy and various toxicities, which have resulted in development of many drugs in this class, as well as the selective COX-2 inhibitors. The limits to their maximum anti-inflammatory effect and lack of efficacy on the underlying disease process has led to development and use of numerous alternative classes of agents, generally referred to as "disease-modifying antirheumatic drugs" (DMARDS). These include: a.) small, low molecular weight drugs, such as certain antimalarial agents (e.g., chloroquine), sulfasalazine (a prodrug of sulfapyridine coupled to 5-aminosalicylic acid), glucocorticoids, leflunomide, and 'antimetabolites' (e.g. methotrexate) and b.) large, high MW biologic agents (protein therapeutics), such as TNF inhibitors (the monoclonal antibody infliximab and the soluble TNF-receptor analogue etanercept, both of which bind TNF and prevent its interaction with its membrane receptor). Other immunosuppressive protein molecules are described at the end of this document. These agents will be discussed further in the Renal, Rheumatology and Oncology Modules. The anti-inflammatory activity of aspirin may explain the decreased risk of colon cancer in long-term users. Bleeding Block in platelet cyclooxygenase synthesis of thromboxane A2 , a potent stimulator of platelet ADP release and aggregation, prolongs bleeding time by inhibiting normal formation of a platelet plug and platelet-induced acceleration of plasma coagulation. The effect of aspirin is prolonged (due to irreversible platelet COX inhibition) and highly selective relative to other NSAIDs. The effect is not observed with acetaminophen. A single analgesic dose of aspirin doubles bleeding time for as long as 4 to 7 days (the life span of a platelet). Aspirin is contraindicated in patients with bleeding disorders, such as severe hemophilia, in patients prior to surgery, and in platelet donors (within 12 hours). Aspirin is recommended in low doses to decrease risk of thromboembolic disorders such as transient ischemic attacks and myocardial infarction. The role of aspirin in the prevention of cardiovascular disease will be discussed further in the Cardiovascular Module . Cardiovascular Effects Recent data indicate that older NSAIDs like ibuprofen, naproxen, and diclofenac, as well as the newer COX-2 selective inhibitors like celecoxib, increase risk of myocardial infarction and are contraindicated in the peri-operative period of coronary artery bypass graft. The FDA currently recommends that the labeling of all NSAIDs includes a boxed warning for the increased risk of thrombotic events, myocardial infarction, and stroke, as the effect was concluded to be a classassociated one. The cardiovascular effects are believed to result from reduction of COX-2-mediated synthesis of prostacyclin (PgI2, a vasodilatory and antiplatelet prostaglandin) in the vascular endothelium, especially where an atherosclerotic process has led to increased expression of COX-2. C. Gastrointestinal Effects NSAIDs (but not acetaminophen) cause dose-dependent increased risk of gastrointestinal blood loss, gastric and duodenal ulceration, and severe hemorrhage; the risk is greater in the elderly and in alcoholics. The effect is related to reduction in prostaglandin levels in the gastrointestinal mucosa. Risk is reduced by concomitant use of the PgE1 analogue misoprostol or with inhibitors of acid secretion such as proton pump inhibitors. The risk is lower with COX-2-selective inhibitors than with nonselective NSAIDs. (The hepatotoxic effect of acetaminophen, which will be considered in a Pathology case discussion and in the GI and Rheumatology Modules, is attributable to one of its metabolites and is unrelated to COX inhibition.) D. Renal Function 1. Fluid retention and decreased sodium excretion from inhibition of renal prostaglandin synthesis, especially in patients with preexisting illness; the effect occurs with nonselective COX inhibitors and COX-2-selective inhibitors. 2. Analgesic nephropathy: papillary necrosis and interstitial nephritis associated with chronic use of NSAIDs and acetaminophen; preexisting renal disease increases risk of drug-associated end-stage renal disease. E. Hypersensitivity-like Syndrome (Aspirin Intolerance Syndrome) NSAIDs may cause bronchospasm, rhinorrhea, and/or urticaria, mediated by leukotrienes and not immunoglobulins. This effect is more likely to occur in asthmatics for whom acetaminophen is therefore preferred as an antipyreticanalgesic
Opioid receptor subtypes
There are a lot - maybe 25+; may explain "opioid rotation" - why when your'e on one opioid a while and become tolerant, another opioid may work (dif receptor) Miu (u1, u2) = the one we'll talk about; agonist = sufentanil Also kappa, delta, ORL
Table 2 below shows the frequency of analgesic use in the two comparison groups. Using individuals who reported "none or rare" use as the reference group, use the "Stat Tools" Excel spreadsheet to compute the odds ratio and 95% confidence limits for daily use of phenacetin.
Those who used phenacetin daily had 6.49 times the risk of renal failure compared to those using it rarely or not at all. The odds ratio is 6.49, indicating that those who used phenacetin daily had 6.49 times the risk of renal failure compared to those using it rarely or not at all. If you chose one of the other answers, it indicates that you either inverted the groups and/or computed a relative risk, which is not correct.
Is Your Patient at Risk for Reye's Syndrome? Reye's Syndrome was first identified in 1963 as an acute disease characterized by encephalopathy and fatty degeneration of the liver. The syndrome typically occurred in children after viral infections, and the case fatality rate was about 20%. There were suspicions that the syndrome was associated with use of medications, and salicylates such as aspirin were high on the list of suspicious agents. The Public Health Service investigated possible etiologic factors in 1985 and 1986. They identified 27 children who met all the criteria for Reye's Syndrome, and compared them to 140 children who were matched by age, sex, race and antecedent illness (respiratory or diarrheal disease or chickenpox). Parents were asked about medications used to treat the viral illness. (JAMA 260:657,1988)
This is a classic example of a case-control study. The outcome of interest is rare, but the investigators were able to study its determinants by finding 27 cases of children who had developed Reye's syndrome and a comparison group of 140 children who did not and then comparing the prior exposures in the two groups.
Is Low Dose Aspirin Beneficial? The Physician's Health Study was conducted to test the hypothesis that 325 mg of aspirin taken every other day would reduce mortality from cardiovascular disease (N. Engl. J. Med. 320:1238, 1989). Male physicians 40 to 84 years of age living in the US in 1980 were eligible to participate. Physicians were excluded if they had a personal history of myocardial infarction, stroke or transient ischemic attack; cancer; current gout; liver, renal or peptic ulcer disease; contraindication to aspirin consumption; current use of aspirin, platelet-active drugs or non-steroidal anti-inflammatory agents; intolerance to aspirin; or inability to comply with the protocol. Eligible subjects who met the inclusion criteria and who successfully completed a run-in phase were randomly assigned to receive aspirin or a placebo. Eventually 22,071 physicians were enrolled; 11,037 were assigned to aspirin, and 11,034 were assigned to placebo. The agents (aspirin and placebo) were identical in appearance and were mailed to the subjects. The recipients' treatment group was coded, and neither the subject nor the investigators knew which treatment group a given subject was in.14. What kind of study was this?
This is obviously a randomized, double-blind clinical trial. Clinical trials are much like prospective cohort studies in design; they differ in that the investigators assign subjects to an exposure, while in a prospective cohort study subjects self-select their exposures or their exposures are unwittingly dictated by circumstance (e.g. asbestos exposure in the shipping industry).
Why did the authors match the comparison groups by age, race, and gender?
To control for confounding by age, race, and gender. Confounding is a distortion of the true association that can be caused when other factors that influence the outcome are unequally distributed among the comparison groups. One way of avoiding confounding is to match the comparison groups with respect to confounding factors. In essence, the investigators then ensure that the groups are equally balanced with respect to the matched characteristics.
Internal versus External Validity The findings cited above for the efficacy of low-dose aspirin in the Physician's Health Study sparked much discussion. There was general consensus the study's primary conclusion (that low-dose aspirin reduced myocardial infarctions in white, middle-aged and elderly, male physicians) was valid, because chance, bias, and confounding were unlikely as alternative explanations for the findings. In other words, the study had internal validity. However, there was much disagreement about whether the findings could be applied to other populations, i.e. whether they were generalizable or had external validity. It should be noted that these physicians had a lower risk of mortality from all causes and from myocardial infarction than the U.S. white or non-white male population as a whole. To some extent there is a trade off between internal and external validity. The Physicians Health Study was restricted to male physicians, because, at the inception of the study, there were relatively few female physicians in the appropriate age group in the US, and their rates of myocardial infarction were exceedingly low. Consequently, it was determined that any conclusions about females would be invalid because of insufficient sample size. The study was conducted in physicians, because they would understand and appropriately respond to follow-up questionnaires, and they would likely provide high rates of follow-up. These advantages increased the likelihood of achieving internal validity, but they limited the extent to which the results could be generalized. The question about efficacy in women was addressed in another large randomized clinical trial published in 2005 (Ridker PM, et al.: A randomized trial of low-dose aspirin in the primary prevention of cardiovascular disease in women. N Engl J Med 2005;352:1293-304.) Methods We randomly assigned 39,876 initially healthy women 45 years of age or older to receive 100 mg of aspirin on alternate days or placebo and then monitored them for 10 years for a first major cardiovascular event (i.e., nonfatal myocardial infarction, nonfatal stroke, or death from cardiovascular causes). Results During follow-up, 477 major cardiovascular events were confirmed in the aspirin group, as compared with 522 in the placebo group, for a nonsignificant reduction in risk with aspirin of 9 percent (relative risk, 0.91; 95 percent confidence interval, 0.80 to 1.03; P=0.13). With regard to individual end points, there was a 17 percent reduction in the risk of stroke in the aspirin group, as compared with the placebo group (relative risk, 0.83; 95 percent confidence interval, 0.69 to 0.99; P=0.04), owing to a 24 percent reduction in the risk of ischemic stroke (relative risk, 0.76; 95 percent confidence interval, 0.63 to 0.93; P=0.009) and a nonsignificant increase in the risk of hemorrhagic stroke (relative risk, 1.24; 95 percent confidence interval, 0.82 to 1.87; P=0.31). As compared with placebo, aspirin had no significant effect on the risk of fatal or nonfatal myocardial infarction (relative risk, 1.02; 95 percent confidence interval, 0.84 to 1.25; P=0.83) or death from cardiovascular causes (relative risk, 0.95; 95 percent confidence interval, 0.74 to 1.22; P=0.68). Gastrointestinal bleeding requiring transfusion was more frequent in the aspirin group than in the placebo group (relative risk, 1.40; 95 percent confidence interval, 1.07 to 1.83; P=0.02). Subgroup analyses showed that aspirin significantly reduced the risk of major cardiovascular events, ischemic stroke, and myocardial infarction among women 65 years of age or older. Based on the information in this abstract, which of the following is true?
Unlike male physicians, the women in this study experienced a significant decrease in ischemic strokes, with no significant reduction in myocardial infarction, except in women over age 65. Response Feedback: This study nicely illustrates the potential dangers of generalizing conclusion beyond the original study group. Unlike the male physicians, women in this study experienced a significant decrease in ischemic strokes, with no significant reduction in myocardial infarction, except in women over age 65. However, like the male physicians, women experienced a significant increase in gastrointestinal bleeding. With close to 40,000 subjects randomly assigned to receive low dose aspirin or placebo over a ten year period, it is unlikely that the study was underpowered.
Environmental Pathology Definition: Study of poisons (distribution, effects, mechanisms of action) Toxic agents enter through skin/lung/GI tract → bloodstream Chemical Agents (Xenobiotics) Air Pollutants Heavy Metals Organic Chemicals Tobacco Alcohol Physical Agents - Type of Injury Mechanical Thermal Electrical Radiation Not included: infectious agents, firearms, drugs, nutrition Chemical Agents (Xenobiotics) Air Pollutants o Outdoor: sulfur dioxide, carbon monoxide, ozone, nitrogen dioxide, particulates o Indoor: formaldehyde, asbestos fibers, radon Heavy Metals - lead, mercury, arsenic, cadmium Organic Chemicals o Volatile: chloroform & carbon tetrachloride, benzene & 1,3-butadiene o Manufactured: organochlorines (polychlorinated biphenyls, dioxin, DDT, lindane), vinyl chloride monomer, phthalate esters, bisphenol A Tobacco - nicotine, polycyclic hydrocarbons, nitrosamines, tar, formaldehyde, nitrogen oxides Alcohol aldehyde, NAD Physical Agents - Type of Injury Mechanical - abrasion, contusion, laceration, incised wound, puncture wound Thermal - burns (superficial, partial thickness, full thickness), hyperthermia (heat cramps, heat exhaustion, heat stroke), hypothermia [systemic (mild, moderate, severe), local (frost bite, trench foot)] Electrical - burns, ventricular fibrillation or cardiac & respiratory center failure, paralysis of medullary centers Radiation o Ionizing (X-rays, gamma rays, particulate) mutations carcinogenes., teratogenesis o UV - sunburn ( wrinkles, cataracts), mutations (pyrimidine dimers melanoma) o Electromagnetic field (radiowaves, microwaves) burns, cancer?
XENOBIOTICS : CYPs = cytochrome P-450 enzymes (ROS byproducts) TO ELIMINATION OR REACTIVE METABOLITE CAUSING TOXICITIY Outdoor air pollutants Smog = smoke + fog Major constituents (in US, upper safety limits set by the Environmental Protection Agency): Sulfur dioxide Carbon monoxide (CO) Ozone (O3, ground-level) Nitrogen dioxide Particulates Major source - combustion of fossil fuels (gasoline, oil, coal, wood, natural gas) by motor vehicles, power plants, factories, homes Respiratory irritants, cause lung damage/inflammation, especially in asthmatics Toxicity mechanisms of some air pollutants Ozone (O3, highly-reactive oxidant) → free radicals → damage to lung epithelium, inflammation) Carbon monoxide (CO) - colorless, tasteless, odorless gas (from burning carbon-containing materials), rapidly oxidized to carbon dioxide (CO2). CO is highly dangerous in close proximity, e.g., automotive fumes in closed garage) → HbCO (carboxyhemoglobin, blocks binding of oxygen) → hypoxia → CNS depression, heart damage, death (mild CO poisoning - dizziness, confusion, headache) Particulates - fine and ultrafine (< 10 μm diam.) → phagocytosed by alveolar macrophages & neutrophils → release of inflamm. mediators (> 10 μm diam. removed by nose) → heart rate irregularities (in severe cases) Formaldehyde (a gas) Foam insulation, glues, wood products Asthma, eye/nose/throat irritation, contact dermatitis, nasopharyngeal cancer (rarely) Asbestos fibers (silicate minerals) Insulation, floor & ceiling tiles, before banned in 1970 Mesothelioma (cancer of lining of pleural or abdominal cavity), lung fibrosis, lung cancer Radon (radioactive gas derived from uranium, greatest single source of background radiation) Soil (high conc. in some basements), uranium mines Lung cancer Lead Water, lead paints (banned in US 1978), leaded gasoline (banned in US 1996) Hematologic, skeletal, neurologic, GI, renal; children > adults (>50% vs ≤15% absorption) Binds to sulfhydryl groups in proteins & blocks Ca metabolism Mercury Contaminated fish (methyl mercury), dental amalgams (metallic mercury vapor) Tremors, confusion, mental retardation (if in utero exposure), death (if high doses) Binds to sulfhydryl groups in some proteins, especially in CNS & kidney Arsenic (historical murder weapon) Soil, water, wood preservers, herbicides Acute GI, cardiovasc. & CNS damage, death (if high amt. ingested); hyperpigmentation & hyperkeratosis; lung, bladder & skin cancers Trivalent arsenic replaces phosphates in ATP → inhibits mitoch. oxid. phophoryl'n Cadmium Nickel-cadmium batteries → water, soil, food Obstructive lung disease, kidney damage, lung cancer (from occup'l exposure) Increased ROS production? Leadlines, death 150, less blood protein, less iq at 10 ug/ml Ground water arsenic poisoning Organic chemicals - occupational & consumer 1) Volatile organic compounds Examples - chloroform, carbon tetrachloride, found in degreasing agents, e.g., dry-cleaning agents, paint removers - benzene, 1,3-butadiene, used in manufacturing of plastics, lubricants, rubbers, dyes Route of exposure - mainly lung exposure Toxic effects - headache, dizziness, impaired liver & kidney function Organic chemicals - occupational & consumer 2) Manufactured products Route of exposure - mainly through skin, GI or respiratory tracts Organochlorines 1. Polychlorinated biphenyls (PCBs) 2. Dioxin (TCDD) 3. DDT*, Lindane 1. Old capacitors, transformers (banned 1977) 2. Incomplete waste inciner. 3. Pesticides (*banned1973) Chloracne, rashes, liver damage; endocrine disrupter, probable carcinogens / → binding to aryl hydrocarbon receptor on cells → transcriptional changes Vinyl chloride monomer (VCM) - gas with sweet odor) Manufacturing (pre- regulation) of polyvinylchloride (PVC) products (pipes, flooring); improper PVC incineration Liver angiosarcoma / ? Processing of metabolites in liver Phthalate esters (used as plasticizers) Flexible plastics (shower curtains, toys, adhesives, catheters) Reproductive toxin in animals ? Human effect Bisphenol A (BPA)? Polycarbonate bottles, coatings of food cans Estrogen mimic (proliferative effect) Chloracne An acne-like eruption, with cysts, hyperpigmentation, and hyperkeratosis; from exposure to chlorinated organics (a.k.a organochlorines). Two incidents (of ~2000 people each) of PCB poisoning in late 1960s in Japan and China, from exposure to contaminated cooking oil → chloracne (Yusho disease in Japan; Yu-Cheng disease in China) 14 Tobacco Cigarette (& cigar & tobacco pipe) smoking causes 1 in 5 deaths/year in the US & 90% of lung cancers (including second hand smoke). Life expectancy for smokers is 10 years less than for nonsmokers (lung cancer, cardiovascular disease, chronic respir. disease). Quitting smoking before the age of 40 reduces the risk of dying from smoking-related disease by ~90%. Smoking during pregnancy → spont. abortion, preterm births↑ birth weight↓ Tobacco cigarette smoke contains > 4000 chemicals, including many toxic agents Toxicity mechanisms of tobacco Nicotine [an alkaloid (organic nitrogen-containing base)] - addictive → nicotinic acetylcholine receptor in brain → catecholamines↑ → heart rate, blood pressure, cardiac output↑ Polycyclic hydrocarbons, nitrosamines - carcinogens Many smoke components (tar, formaldehyde, nitrogen oxides) → inflammation, mucus production (bronchitis), neutrophil recruitment to lung↑ → elastase↑ → tissue injury → emphysemaEmphysema, an irreversible lung disease, results from destruction of elastin in alveolar walls; patients have difficulty breathing; Chronic obstructive pulmonary disease (COPD) = chronic bronchitis, emphysema Alcohol (ethanol) Mechanism of alcohol toxicity Alcohol is metabolized mainly in the liver, but also in brain and GI tract. Alcohol metabolism decreases NAD and generates toxic acetaldehyde: NAD is required for fatty acid oxidation fat accumulation; acetaldehyde is a carcinogen (interferes with DNA replication and repair), contributes to incoordination, memory impairment, sleepiness, and can cause facial flushing, nausea, rapid heart beat. Genetic variations: variants of the ADH and ALDH enzymes in different individuals determine the acetaldehyde level and hence the level of 'tolerance' to alcohol. Fast ADH and/or slow ALDH protect against alcoholism (e.g., slow ALDH variant in 50% of Asians). Health effects of heavy alcohol consumption Exhaled alcohol is proportional to blood level Breath Test - 80 mg/dL blood = drunk driving in the U.S. 200 mg/dL - drowsiness 300 mg/dL - stupor (greatly diminished responsiveness) Higher levels - coma with possible respiratory arrest Heavy alcohol consumption accidents, homicides, suicides, personal violence. Acute alcoholism: Mainly CNS effects [depression of neuronal centers, including those that regulate respiration (respiratory arrest at very high alcohol levels)] Sometimes reversible liver and stomach damage, e.g., fat accumulation in hepatocytes (fatty change), acute gastritis & ulceration Chronic alcoholism: ~15 million chronic alcoholics in the U.S. Liver and GI tract: Fatty change, alcoholic hepatitis, cirrhosis (loss of hepatocytes and irreversible scarring) portal hypertension large swollen veins (varices) in GI tract, which may rupture life-threatening complications; risk of liver cancer; cognitive decline due to poor liver function; also bleeding from gastritis or gastric ulcers. Cardiovascular system: injury to myocardium alcoholic cardiomyopathy Fetal alcohol syndrome (from consumption of even small amounts during pregnancy, esp. in 1st trimester): microcephally, facial abnormalities, growth retardation, reduced mental functioning; affects ~3 per 1000 children born in US. Mechanical trauma (not included: head & bone injuries) Leading cause of death in the 1- 44 yr. age group Trauma occurs when a force of sufficient magnitude is applied to the body. The force can be: accelerating or decelerating blunt or sharp accidental or deliberate Soft tissue injury types: abrasion (scraping or rubbing) removal of superficial layer contusion (bruise from blunt object) extravasation of blood into tissue laceration (tear or disruptive stretching from blunt object) intact bridging blood vessels incised wound (from sharp object) severed bridging blood vessels puncture wound (pierced tissue from penetration of long & narrow sharp object) - penetrating or perforating (if exit wound also formed) Determinants of the clinical significance of a thermal burn Depth of burn Percent of body surface involved Internal injuries from inhalation of hot & toxic fumes Promptness & efficacy of therapy Classification of Burns by Depth Superficial (formerly 1st degree) Limited to epidermis Red, dry, painful Partial Thickness (formerly 2nd degree) Epidermis + part of dermis destroyed Red, moist (blisters), painful Full Thickness (formerly 3rd and 4th degree) Epidermis + dermis destroyed Anesthetic Not capable of regeneration High risk of infection Thermal injury - hyperthermia Heat Cramps - from loss of electrolytes via sweating Heat Exhaustion (most common) - prostration (extreme physical weakness) and brief period of collapse (due to hypovolemia caused by dehydration); rehydration recovery Heat Stroke (most serious) • Due to high ambient temp/humidity cessation of sweating • Advanced age, physical stress are major risk factors Prolonged core temp > 40oC (104oF) Peripheral vasodilation Reduced blood flow to brain/heart Confusion/coma/death Thermal injury - hypothermia • Prolonged exposure to low ambient temp • Homelessness is major risk factor Effects of systemic hypothermia (drop in core temp) Mild 32-35oC (90-95oF) Hyperventilation Lethargy Vigorous shivering Moderate 28-32oC (82-90oF) Hypoventilation Confusion Loss of coordination Severe <28oC (<82oF) Unconsciousness Slow or no breathing Weak or no pulse Effects of local hypothermia (e.g, frostbite, trench foot) - Suppression of vital metabolism - Crystallization of intra- & extracellular water - Increased permeability of vessels - Ischemia, hypoxia, infarction "Trench foot" - gangrene Electrical injury From contact with low-voltage current (home, workplace = 120 or 220v, alternating; wet skin lowers resistance 100-fold) or high-voltage currents (high power lines, lightning) Severity of injury is determined by: type and intensity of current path of current resistance of tissues duration of exposure Types of injuries: Burns - at entry & exit sites & internal organs ventricular fibrillation or cardiac & respir. center failure (due to disruption of normal electrical impulses) Alt. current tetanic muscle spasm irreversible clutching; severe spasm of chest wall muscle asphyxia High-voltage current paralysis of medullary centers & extensive burns 29 Radiation injury types of radiant energy - sources / uses Electromagnetic radiation (wave-propagated) Radio (RF - radio, TV, cell phone, WiFi, radar), microwave Infrared (IR, felt as heat, most encountered), visible Ultraviolet ( - UVR from sun) X-rays [from firing electrons at a metal target - X-ray imaging, computed tomography (CT) scans (computer-processed combination of many X-ray images)] Gamma rays ( - cancer cell killing, sterilization) Particulate radiation Alpha particles (2 protons & 2 neutrons - smoke alarms) Beta particles (electrons - paper & aluminum foil production) Neutrons (react with nuclei of other atoms new isotopes) EM spectrum Sensitivity of Cells/Tissues to Ionizing Radiation Sensitivity level High (< 25 Sv *) Lymphoid and hematopoietic cells, germ cells, GI epithelium Moderate Skin, blood vessels, squamous epithelium, growing bone and cartilage Low (> 50 Sv) Kidney, muscle, brain, endocrine organs, adult bone and cartilage * Sievert (Sv) = unit of equivalent biologic dose of radiation = Gray (Gy, energy absorbed by a tissue per unit mass) x the relative biologic effectiveness of the radiation. Injuries Caused by Ionizing Radiation Vascular damage Inflammation Fibrosis (especially lungs radiopneumonitis) Acute - short-lived, reversible • erythema • pigmentation • depletion of Langerhans cells Long-term - cumulative, largely irreversible • degeneration of elastin and collagen wrinkled and leathery skin • cataracts Melanoma: neoplastic: UVB pyrimidine dimers in DNA mutations or transcriptional errors cancer Research: Dose-related risk: high levels cause burns and possibly cancer; main global concern is with long-term low level exposure Based on > 25,000 published studies, consensus is little or no risk except for "prolonged and heavy" mobile phone use (? brain cancer) The World Health Organization has classified cell phones as "possibly carcinogenic to humans" - long term studies needed.
Tobacco
[14] Cigarette smoking (including cigar & tobacco pipe & "second-hand" smoking) is responsible for 90% of lung cancers and for 1 in 5 deaths in the US each year. Lung cancer, cardiovascular disease, and chronic respiratory disease account for most of the smoking- related deaths. Life expectancy for smokers is at least 10 years lower than for nonsmokers, although quitting smoking before the age of 40 reduces the risk of dying from smoking-related diseases by 90%. Smoking is contra-indicated during pregnancy, as it greatly increases the risk of spontaneous abortion and preterm birth, and causes low-birth weight. [15-17] Cigarette smoke contains thousands of chemicals and many toxic agents. Nicotine [(an alkaloid (organic nitrogen-containing base)] is highly addictive; it binds to nicotinic acetylcholine receptors in the brain, and stimulates the release of catecholamines from sympathetic neurons, leading to increased heart rate, blood pressure, and cardiac output. Other components of cigarette smoke include known or suspected carcinogens, like polycyclic hydrocarbons, which bind to the aryl (aromatic) hydrocarbon receptor, and nitrosamines, which are associated with increased risk of gastric cancer. Furthermore, some of the toxins in cigarette smoke injure endothelial cells and thus smoking increases the risk for development of atherosclerosis (hardening and narrowing of the arteries), which can lead to ischemia (inadequate blood supply) and myocardial infarction (heart attack). Many smoke components, like tar (the partially-combusted particulates), formaldehyde, and nitrogen oxides, are irritants that cause inflammation with mucus production, leading to chronic bronchitis. The inflammatory mediators in the lung recruit neutrophils that produce elastase, which destroys the elastin in alveolar walls. This leads to enlarged air spaces, with insufficient gas exchange and impaired respiratory function, and can lead to the irreversible lung disease called emphysema. Chronic bronchitis and emphysema are two conditions that comprise the so-called chronic obstructive pulmonary disease (COPD).
How much agonist needed in system given a certain level of antagonist:
a'/a = 1 + ([B]/KB) E.g. For [B] = KB, a'a = 2 [B] = 2KB, a'/a = 3 [B] = 9KB, a'/a = 10
XII. In another experiment, the i.v. injection of 25 mg/kg of chloramphenicol to a 16.5 kg dog was found to produce bacteriostatic serum concentrations. In comparison to a dose of 50 mg/kg, this dose would probably result in:
a. A shorter elimination half-life No; from the serum data provided you know that the elimination conforms to laws of first-order kinetics for amounts in the body that would be achieved by a 25 mg/kg dose. Consequently, the half-life is independent of the dose. You don't know, however, whether this is true for doses greater than 50 mg/kg i.v. The higher the dose the greater the likelihood of saturating a mechanism of elimination mediated by enzymes. Go back to XII and make another choice. b. A smaller renal clearance No; you have no basis for making this conclusion. Furthermore, renal clearance is usually independent of dose. Make another choice. c. A smaller volume of distribution No; in the usual case the Vd of a drug does not change with dose. Go back to Item XII. d. A halving of the duration of bacteriostatic effect in serum No; for drugs administered as an iv bolus and eliminated by first-order processes, with a close correspondence between plasma concentrations and a reversible effect, the duration of action is not proportional to the dose, but is proportional to the log of the dose. It takes geometric increases in bolus doses to produce arithmetic increases in duration of action. The time that elapses for the 50µg/kg amount in the body to fall to the 25 µg/kg level is equal to one elimination half-life. The duration of action is therefore one half-life less with the 25 µg/kg dose as compared to the 50 µg/kg dose. Similarly, you would predict that 100 µg/kg would produce a duration of action one half-life longer than the 50 µg/kg dose. Having pondered this a bit, you are ready to reconsider the correct answer to Item XII. e. A 1-hr reduction of the duration of bacteriostatic effect in the serum Yes; the duration of bacteriostatic effect is reduced by one elimination half-life, which for chloramphenicol is about 1 hour. If you haven't already, you may find it useful to read the explanation for choice XIId. If you've considered this explanation, then charge forward to the LAST COMMENT below!
II. The elimination half-life of chloramphenicol is:
a. About 30 minutes No; the subject's serum was sampled and assayed for chloramphenicol at 30 minute intervals initially, but this is not the t1/2 value. Do you understand how to determine the t1/2? Determine the time interval for the concentration to drop 50%. Try Item II again. b. About 1 hour Yes; since the elimination of chloramphenicol conforms to the laws of first-order kinetics, the data are described by the following equation: ln Cp = ln C0 - kel where kel, the slope of the plot of ln plasma concentration vs. time, is the fraction of the drug eliminated per unit time. The half-life is the time it takes to decrease the concentration (C) by half (1/2C). Consequently, the half-life t1/2 = [ln (C/ 1/2C)]/kel = [ln 2]/kel = 0.693/kel. Thus: t1/2 = 0.693/kel Since kel = (ln C1 - ln C2)/(t1 - t2) = 0.64/hr, then t1/2 = 1.1 hr. By inspecting the data, you can see that Cp decreases to about half its value in 1 hour. Now go on to Item III. None of the above No; Inspect the plasma concentrations after i.v. administration. How long does it take for the levels to drop by one half? Choose any serum concentration of X. Find the time t1 at which X occurs. Then find the time t2 corresponding to 1/2X. The serum half-life is t2 - t1, the time required for reduction of the serum concentration by one-half. [If you made a plot of ln serum concentration vs. time, check your calculations of the slope kel. Then reconsider the relationship between kel and t1/2 (t1/2 = 0.693 / kel). Try Item II again
D. Adherence to Cell Surfaces 1. Bacteria use specialized structures (pili or fimbriae) or substances (capsules, glycocalyx) to adhere to cell surfaces (usually mucosal)
a. Adhesins on pili mediate attachment to specific receptors on tissues and prevent bacteria from being washed away; may also determine tropism. b. MSCRAMMs (microbial surface components recognizing adhesive matrix molecules) are proteins expressed and secreted by Streptococci, Staphylococcus aureus, and other bacteria that bind components of the extracellular matrix of epithelial cells, e.g. fibronectin, collagen, laminin. c. Capsules, glycocalyx mediate attachment to tissues and inanimate surfaces non-specifically. d. Some of these structures also mediate attachment of bacteria to other bacteria, e.g. during biofilm formation. 2. Bacteria adhere especially well to foreign bodies, like artificial heart valves and joints. E. Colonization 1. After adherence, bacteria typically multiply before symptoms are observable, i.e. end of the incubation period. 2. After bacteria have colonized and multiplied, usually at the site of entry, invasion (of cells and/or tissues) and spread to other parts of the body may occur. There are numerous virulence factors that enhance invasion and often contribute to tissue damage. a. Ex. Collagenase and Hyaluronidase i. degrade collagen and hyaluronic acid, respectively. ii. facilitate spread (invasion) of bacteria through subcutaneous tissue. b. Ex. Lecithinase (phospholipase): damages host cell membranes c. Ex. Streptokinase (fibrinolysin): activates enzyme in plasma that dissolves coagulated plasma; may facilitate spread of bacteria.
XI. In this experiment the chemical assay for nitro groups was also used to determine serum and urine content of nitro-containing compounds (both chloramphenicol and its metabolites). For a given sample, total nitro content minus chloramphenicol content indicates metabolite content. The data for chloramphenicol glucuronide, the major metabolite, indicate a renal clearance of 96.3 ml/min and a cumulative urinary excretion of 60.5% of the chloramphenicol dose after i.v. administration in the 16.5 kg dog. These data suggest that:
a. Chloramphenicol glucuronide is eliminated in part by renal tubular secretion, but a considerable portion of the dose is eliminated by another mechanism, possibly in the bile Yes; The ClR of the metabolite is greater than that of inulin in the dog, consistent with renal tubular secretion. This is not surprising since glucuronides are organic acids secreted by the carrier mechanisms in the proximal tubules. Glucuronide conjugates are also often secreted via the bile. Proceed to Item XII — the end is in sight! b. The bacteriostatic effect of chloramphenicol in the urine is primarily caused by its metabolites No; remember that chloramphenicol in this study was measured by a microbiological assay. Its metabolites, the primary one being the glucuronide conjugate, are inactive against microorganisms. Some drug metabolites are active, but glucuronides generally are not. The assay for total nitro compounds in urine may detect considerably more material than the bioassay because the inactive metabolites are extensively excreted by this route. Return to Item XI. c. Renal impairment in a patient is more likely to increase the serum concentrations of chloramphenicol than of its metabolite No; chloramphenicol appears to be extensively eliminated by biotransformation, and its metabolite is extensively cleared by renal tubular secretion into the urine. Go back to Item XI.
The total clearance (ClT) of a drug indicates the clearance from the body by all routes and mechanisms. This value can be estimated from: ClT = (0.693/t1/2)Vd (Suggestion: Use half-life in min and Vd in ml so your estimate of ClT is in ml/min. Do you get a value for chloramphenicol in the dog of about 195 ml/min?). Or if kel has already been calculated, it can be computed from: ClT = kel Vd, where kel is the slope of the ln Cp vs. t plot after i.v. administration. Comparison of the total clearance of chloramphenicol (195ml/min) to its renal clearance (See comment to Item VIIIb) indicates that:
a. Chloramphenicol is cleared only by the kidney, and not by the liver or other organs No; the total clearance of chloramphenicol, 195 ml/min, substantially exceeds the renal clearance, 20 ml/min, so additional routes of elimination must occur. Try Item X again. b. Chloramphenicol is cleared by the liver, as well as by the kidney Since the total clearance exceeds the renal clearance, you are correct in assuming clearance of chloramphenicol occurs by another organ. The liver is a good bet because of its capacity for biotransformation and biliary excretion. However, since you don't have any data yet on chloramphenicol in bile or on metabolite formation by the liver, there is a better answer to Item X. c. Chloramphenicol is cleared from the body partly by biotransformation No; clearance of chloramphenicol by biotransformation may explain why the total clearance greatly exceeds the renal clearance. And you might expect that the hydroxyl groups are sites for glucuronide conjugation, mediated by glucuronyl transferases in the liver. However, since you don't have any data on metabolites in the plasma, urine, or bile, this conclusion is not yet justified. For example, the nonrenal clearance could be attributable exclusively to biliary excretion of chloramphenicol without any metabolite formation. So there is still a better answer to Item X, and here's your chance to find it! Go back to Item X. d. Nonrenal mechanisms account for about 90% of the clearance of chloramphenicol Yes; that is true. The total clearance, based on your estimates of half-life or kel (see comment to Item IIb) and Vd (see comment to Item IIc), is 195 ml/min; renal clearance (see comment to Item VIIb) is 20 ml/min. The difference of 175 ml/min, which is 90% of the total, must reflect clearance by nonrenal mechanisms. Note: As would be expected, this estimate of nonrenal clearance (as a percent of total clearance) agrees with the percent of the dose which is not recovered in the urine, 100% - 9% = 91% (see comment to Item VIa), and which must be eliminated by biotransformation and/or nonrenal excretion. Having mastered this item, now try Item XI.
VIII. The value of renal clearance of chloramphenicol in the dog indicated that:
a. Chloramphenicol is filtered by the glomeruli Even without calculating the renal clearance, you can be fairly confident that this drug, and most drugs except protein therapeutics, are filtered by the glomeruli, if present in the plasma (and not 100% bound to plasma proteins!). However, this conclusion is incomplete; go back to Item VIII and consider another answer. b. Chloramphenicol is incompletely filtered by the glomeruli and/or partially reabsorbed Correct: In the dog the renal clearance of chloramphenicol, about 20 ml/min, is less than half that for inulin, about 50 ml/min. Two explanations for a renal clearance less than the glomerular filtration rate are: 1) Not all the drug is filtered out of the blood because of binding to plasma proteins. Chloramphenicol is reported to be about 50% bound at therapeutic concentrations. 2) Some of the filtered drug is reabsorbed from the tubules. You have found that chloramphenicol appears to pass readily through cell membranes, so it is reasonable that some of the drug would be reabsorbed. A definitive study to determine the mechanism of renal clearance of chloramphenicol would entail measurement of free chloramphenicol in serum and calculation of renal clearance based on these data. Now try Item IX. c. Chloramphenicol is filtered, partially reabsorbed, and secreted No; it is not possible to determine from a renal clearance value less than that of inulin whether tubular secretion has taken place. You can conclude that there is no NET tubular secretion. Go back to Item VIII.
E. Specialized Structures 1. Capsule
a. Gelatinous layer surrounding the bacterial cell; gives many bacterial colonies a mucoid appearance. b. Composed of polysaccharide (except in Bacillus anthracis) which varies among bacteria and is used in identification. c. 4 reasons the capsule is important: i. It is a virulence factor; inhibits phagocytosis. ii. Antibodies vs. capsular polysaccharides used to identify bacteria a. Quellungreactionlabtest—useofcorrectreference antibody causes capsule to swell and become more visible by microscopy. iii. Capsular polysaccharides elicit protective antibodies as antigens in certain vaccines; Ex. Capsular polysaccharides from 23 types of Streptococcus pneumoniae are in the Pneumovax 23 vaccine (unconjugated). Some are conjugated to protein to promote T cell activation and class switching from IgM to IgG for a memory response; Ex. Neisseria meningitidis Prevnar vaccine, Haemophilus influenzae type B (Hib) conjugated vaccine. v. Plays a role in bacterial adherence to human tissues and in formation of biofilms. 2. Flagella a. Long, filamentous appendages that propel bacteria towards nutrients and other attractants (chemotaxis). b. Composed of multiple copies of a single protein, flagellin organized in intertwined chains. c. Proton motive force provided by ATP provides energy for movement. d. Present in characteristic numbers (1 or many) and arrangements (at the end or all over the bacterial surface). e. Most common in rods; rarely found in cocci. f. May play a role in pathogenesis; Ex. E. coli and Proteus vulgaris are common causes of urinary tract infections (UTIs), perhaps because their flagella move them up the urethra into the bladder. g. Antibodies vs. flagellar proteins are used to identify some bacterial species; Ex. Salmonella and E. coli species (O157:H7 E. coli).
3. Pili(Fimbriae)
a. Hair-like filaments extending from cell surface. b. Shorter, straighter than flagella. c. Composed of the protein, pilin, organized in helical strands. d. Found mainly on Gram-negative organisms. e. Pili mediate attachment of bacteria to specific receptors on human cells via adhesins, molecular substructures usually present at the tips of pili; can be considered a virulence factor. Pili also mediate attachment to other bacteria. f. F (aka fertility or sex) pili function during conjugation; the genes for their expression are on plasmids. 4. Secretion Systems a. Some Gram-negative bacteria have secretion systems that mediate transfer of proteins and other factors from the bacterial cell to eukaryotic cells. These factors are usually virulence factors that promote disease production. At least six different secretion systems have been identified and are referred to as Type (I -VI) Secretion Systems. They have been evolutionarily conserved and are often encoded on transmissible plasmids. 5. Glycocalyx(slimelayer) a. Polysaccharide coating secreted by many bacteria that mediates adherence to skin, heart valves, catheters, etc. even teeth (basis of plaque and cavity formation); i.e. formation of biofilms. Similar to a capsule, but more loosely constructed.
accuracy vs precision vs validation
accuracy = measures how close a method is in providing a test value that is *close to the "true" value* precision = measures the *reproducibility* of the assay such that if a test is performed multiple times for a given sample, the results should be similar
IX. The rate of renal excretion of chloramphenicol and its renal clearance most likely:
a. Increase if the pH of the urine is decreased, as occurs with basic drugs such as amphetamine (pKa=10) Recall that chloramphenicol is a neutral compound that does not become charged at physiologic pH. It is therefore unlike amphetamine, a primary amine that at lower pH takes on more hydrogen ions and is less well reabsorbed from the renal tubules. Try Item IX again. b. Are unrelated to the pH of the urine Yes; recovery of chloramphenicol in the urine (9% of the dose after i.v. administration) indicates that only a small amount of the drug is cleared from the blood by the kidney. The renal clearance indicates chloramphenicol may undergo partial tubular reabsorption. But the drug is a neutral compound that does not become ionized at physiologic pH. So the pH of the urine should not influence the degree of tubular reabsorption. Therefore the rate of renal excretion and renal clearance of chloramphenicol is NOT likely to be affected by renal pH. Proceed to Item X. c. Increase if the pH of the urine increases, as occurs with acidic drugs such as salicyclic acid (pKa=3) No; a drug in unionized form is more lipid soluble than its ionized counterpart. Reabsorption of unionized drug occurs more readily from the tubular fluid back into the blood. The extent of reabsorption is therefore dependent on the degree of ionization of the drug in the tubular fluid. Since salicylic acid has a pKa of 3, as the pH of the urine increases less of the drug is in unionized form. Consequently, reabsorption occurs more slowly and more of the drug is recovered in the urine. But chloramphenicol does not have a carboxylic acid group like salicylate and does not behave like an acid. Return to Item IX.
F. Ways That Bacteria Cause Tissue Damage and Disease 1. Invasion and Inflammation
a. Invasive bacteria can spread by invading cells, tissues, the bloodstream and the lymphatic system and induce acute inflammation, locally (characterized by redness, swelling, heat, pain) or systemically (characterized by fever, leukocytosis, tachycardia, tachypnea, increase in acute phase proteins). Typically, an acute inflammatory response is resolved with clearance of the organism, however chronic inflammation can occur if the infection persists. b. Bacteriacancausedifferenttypesofinflammation: i. Pyogenic (pus-producing; acute) in which neutrophils predominate ii. Granulomatous (chronic) in which macrophages and T cells predominate 2. Toxin production a. Exotoxins i. Secreted polypeptides produced by some Gram-positive and some Gram- negative organisms. ii. Often encoded by genes located on plasmids or lysogenic phages. iii. Some are extremely toxic with less than 1 μg in a fatal dose for a human. iv. Most are destroyed by heating >600C. v. Can produce disease at sites distant from the organism. vi. Are good antigens; induce protective antibodies (antitoxins). vii. Can be converted to an inactive form, i.e. toxoids, used in effective vaccines, when treated with formaldehyde, or other denaturing conditions. viii. Many have an A-B subunit structure: a. A (active) subunit has the toxic activity. b. B (binding) subunit mediates binding to specific cellular receptors. ix. Some are superantigens x. Exotoxins produce a variety of symptoms via different mechanisms of action.
IV. In the dog, as in a human adult male of average body weight and composition, the volumes of plasma, extracellular and total body water average 4%, 17%, and 58% of body weight, or 0.04, 0.17, and 0.58 l/kg respectively. Therefore, the apparent volume of distribution of chloramphenicol in the dog corresponds approximately to which of the following body fluid compartments:
a. Plasma volume No; divide the Vd of chloramphenicol (18.3 l, see comment to Item IIIc) by the weight of the subject (16.5 kg) and compare the Vd in l/kg to that of plasma (0.04 l/kg or 4% of body weight). Go back to Item IV. b. Intracellular fluid volume No; would you anticipate that a drug which is administered into the vasculature and which passes across vascular walls would not be distributed also to the extracellular fluid? Non-uniform distribution of the drug might result in a calculated volume corresponding to the intracellular fluid space - but that's not true in this case! Go back to Item IV. c. Extracellular fluid volume No; A Vd of 18.3 l in a 16.5 kg subject is substantially greater than 17% of body weight, which is the approximate size of the extracellular fluid volume. Go back to Item IV. d. Total body water No; Total body water is about 58% of body weight which in this subject would be 9.6 liters. Go back to Item IV. e. Greater than total body water Correct; 18.3 l represents 1.1 l/kg body weight or 110% of the total body weight of this subject, considerably higher than the average value of about 58% for total fluid volume. The drug may not distribute uniformly; sequestering at some site outside the plasma volume would reduce the value of the initial serum concentration and increase the apparent volume of distribution. Because the calculated Vd is so high, it is reasonable to conclude that choramphenicol readily crosses membranes and distributes into cells and fluid spaces such as the CSF. Now proceed to Item V.
I. The elimination of chloramphenicol from the serum after it is given i.v. conforms to the laws of:
a. Zero-order kinetics No; a drug is eliminated according to zero-order kinetics if a constant amount is eliminated in equivalent units of time, regardless of the amount of drug present to be eliminated. In this case, the amount eliminated from the serum decreases in each successive 30-minute period. Please go back to Item I. b. First-order kinetics Yes; inspection of the serum concentrations (Cp) of chloramphenicol indicated that in successive 30-minute periods after i.v. administration the percent decrease is constant, whereas the absolute decrease becomes smaller. Your graph of the data with ln of Cp on the ordinate (y-axis) and time on the abscissa (x-axis) is linear. (If you had not made the logarithmic transformation of Cp and had graphed Cp vs. t, your data would be clearly curvilinear.) These observations are consistent with elimination by first-order kinetics. Note that, according to the definition of first-order kinetics, the rate of elimination of drug from plasma is proportional to the plasma concentration. This statement is describable as: ΔCp / Δt = kelCp. The integral of this differential equation is lnCp = lnC0 - kelt, where C0 is the plasma concentration at zero time. So data conforming to first-order elimination are described by an equation of this form. As in this case, with chloramphenicol, a plot of ln Cp vs. t is a straight line with an intercept on the ordinate of ln C0 and a slope of kel, the elimination rate constant. . Note that the elimination t1/2 = 0.693/kel Now proceed to Item II. c. Mixed-order kinetics (a combination of zero-order and first-order kinetics) No; perhaps you should plot the serum data? What does the shape of the curve tell you about the kinetics of elimination? How did you rectify the curve, i.e., transform the data in order to generate a straight line? Go back to Item I.
5. The growth cycle of bacteria in broth culture has 4 major phases:
a. lag phase: period of adaptation to environment and preparation for cell division with high metabolic activity, no cell division. b. log phase: period of rapid cell division and production of cell constituents, including peptidoglycan. β-lactam drugs are most effective during this phase. c. stationary phase: growth slows due to nutrient depletion and accumulation of toxic products; cell number in a steady state due to a balance of cell division and cell death. d. death phase: number of viable bacteria declines. e. Gene expression can vary greatly during these different phases, e.g. cells in stationary phase are often more resistant to stresses than cells in log phase. 6. How are bacteria counted? a. Direct cell count: does not determine if cells can divide b. Turbidity of culture: proportional to the cell mass c. Viable cell counts: dilutions of the specimen or culture are tested for growth on nutrient agar plates. Used to determine the number of colony-forming units (CFU) per milliliter, i.e. the number of cells capable of dividing under provided conditions. Ex. Lab test for diagnosis of UTIs.
mature teratoma
arises from germ cells, and can give rise to different types of tissue benign
Endotoxins
b. Endotoxins i. Integral parts of cell walls of both Gram-negative rods and cocci; lipopolysaccharides (LPS) or lipooligosaccharides (LOS). ii. Encoded by genes located on the bacterial chromosome. iii. Lower toxicity than exotoxins. iv. Are released upon lysis of bacteria or sometimes by "blebbing". v. Are weak antigens; do not effectively induce protective antibodies, so no endotoxin toxoids or vaccines. vi. Best-established cause of sepsis. a. Septic shock is a leading cause of death in ICUs and has a mortality rate of 30-50%. vii. Also cause disseminated intravascular coagulation (DIC) due to activation of the coagulation system, resulting in thrombosis, tissue ischemia and ultimately multiple organ failure. viii. Endotoxin effects are due to induction of the production of cytokines, including interleukin-1 (IL-1) and tumor necrosis factor (TNF). ix. Intravenous fluids are sterilized by filtration to eliminate LPS, since it cannot be inactivated by heat. x. Endotoxin-like effects can be also caused by peptidoglycan, and teichoic or lipoteichoic acids of Gram-positive organisms, like S. aureus, but these are usually not as potent as LPS. 3. By-products of Bacterial Growth a. Acids, gas, and other toxic substances produced during bacterial metabolism can cause tissue damage.
Identify the major therapeutic applications of muscarinic cholinergic agonists and antagonists.
c) Botulinumtoxin (1) Produced by the ubiquitous gram-positive anaerobic bacterium Clostridium botulinum, botulinum toxin specifically enters cholinergic nerve terminals, where it enzymatically degrades proteins required for vesicular fusion and acetylcholine release, producing a long-lasting presynaptic impairment of cholinergic neurotransmission (2) Botulismpoisoning (a) Poisoning is typically the result of ingestion of contaminated food containing the toxin, typically food that is not completely sterilized before being stored under anaerobic conditions (e.g. in canning) and eaten without sufficient cooking to inactivate the toxin. Actual infection by Clostridium botulinum is rare in adults, but sometimes occurs as a result of wound infection. Infection may also occur in infants by colonization of the infant digestive tract, which is more vulnerable than the adult GI tract due to lower acidity. Honey may contain Clostridium botulinum spores and is a risk factor for infant botulism. (b) The primary symptom is block of cholinergic neurotransmission, resulting in voluntary muscle paralysis and autonomic blockade. Death may result from paralysis of respiratory muscles. Early treatment with botulism antitoxin can limit the effect of the toxin, but cannot reverse the effect on terminals that have already internalized the toxin. (3) The enzymatic toxin remains active within the nerve terminal for prolonged periods of time. Only one molecule of toxin is required to disable a terminal. Recovery is primarily by axonal sprouting, typically on a time scale of months. (4) Therapeutic uses (a) Cosmetic: localized facial paralysis to reduce wrinkling (b) Treatment of focal dystonias (c) Treatment of spasticity resulting from stroke, brain or spinal cord injury, multiple sclerosis, cerebral palsy (d) Treatment of nondystonic muscle activity disorders: e.g. blepharospasm, hemifacial spasm, tics, tremor, hereditary cramps (e) Treatment of localized muscle cramps (f) Treatment of smooth-muscle hyperactive disorders (g) Treatment of sweating disorders (5) Adverseeffectsofbotulinumtoxin:Adverseeffectsincludemuscle weakness due to spread of the effect beyond the intended region. Due to the extended duration of botulinum toxin action, such unintended effects are long lasting. Use in the head and neck region sometimes results in dysphagia. Anaphylactic reactions have also been reported. In 2008, the FDA issued a warning that botulinum toxin "been linked in some cases to adverse reactions, including respiratory failure and death, following treatment of a variety of conditions using a wide range of doses."
d-Amphetamine Methylphenidate Tyramine (Octopamine) (not for adhd) degraded by MAO; when MAO is inhibited, can trigger a hypertensive crisis by release of NE from nerve terminals tyramine is converted to octopamine and stored in sympathetic vesicles but DOES NOT have action. Long term MAO therapy can therefore impair sympathetic nervous system function Indirect Agonist/Central Stimulant-->Indirect acting Sympathomimetics
can directly stimulate a1+B1 increases NE and dopamine release; treatment of attention deficit disorder
benign neoplasm
cells resemble normal cells well circumscribed (encapsulated) localized - don't spread to other sites amenable to surgical excision
effects of local hypothermia
e.g. frostbite, trench foot - suppression of vital metabolism - crystallization of intra and extracellular water - inc. permeability of vessels - ischemia, hypoxia, infarction
organophosphates
e.g. parathoin, malathoin, sarin irreversible AChE inhibitors (usually via covalent bond) --> more ACh, more nicotinic and muscarinic transmission (inc. parasymp!) => pesticides, nerve gas tx: - atropine to block muscarinic transmission - symptom treatment only possible fix = pralidoxime Binding of the inhibitor can be reversed in the initial stage by cholinesterase regenerators such as *pralidoxime*, but aging renders inhibitory effect irreversible until new receptors are created by body
Glucocorticoids cortisol (hydrocortisone); corticosterone DMARDS (disease modifying anti-rheumatic drugs)
equal affinity for GC and MC receptors; converted to cortisone (low affinity for MC receptors) by 11B hydroxysteroid DH in the kidney, salivary gland, and colon IC receptors with hGRa receptor; translocate into nucleus and interact with transcriptional regulators (glucocorticoid response elements, GREs)-->change gene expression; receptors are downregulated with GC is high cortisol (hydrocortisone); corticosterone DMARDS (disease modifying anti-rheumatic drugs) equal affinity for GC and MC receptors; converted to cortisone (low affinity for MC receptors) by 11B hydroxysteroid DH in the kidney, salivary gland, and colon see notes for mechanism of immune suppression replacement therapy for adrenal disorders (use hydrocortisone specifically); increase lung development in premature infants prolonged treatment is not safe due to toxicities and suppression of HPA axis (takes a year to reach physiological concentrations of cortisol) duration of action 8-12 h IC receptors with hGRa receptor; translocate into nucleus and interact with transcriptional regulators (glucocorticoid response elements, GREs)-->change gene expression; receptors are downregulated with GC is high note from endo/repro: GC is essential for maintaining vascular tone and making hypotonic urine anti-inflammatory effect; RA and lupus; asthma and COPD; second line treatment for severe allergic reaction; edema aossicated with tumors; Bell's palsy toxicities: cushing syndrome (infection, impaired wound healing, osteoporosis, muscle wasting, hypertension, hyperglycemia, fat dposition, behavioral changes) can use local administration (inhalers, topical) to reduce toxicity; oral administration with high first pass effect; TAPER ON WITHDRAWAL
increased vascular permeability
histamine & serotonin, C3a & C5a, leukotrienes C4, D4, E4 substance P, bradykinin, prostaglandins, NO
Infliximab large, high MW protein; biologic TNF-a antagonist; monoclonal antibody; binds to TNF and prevents it from activating recetor
increases risk of infection arthritis and inflammatory bowel disease long half life
causes of granulomas
infectious - mycobacteria (TB, leprosy) - coccidiomycosis - blastomycosis - spirochetes - many others foreign body idiopathic (sarcoidosis, crohn's disease) other examples: - wegener's granulomatosis [=>necrotizing vasculitis, anti-neutrophil abs] - chronic granulomatous disease [=>inherited deficiency of NADPH oxidase, not enough ROS in cells])
drug input
input = F * dose / dosing interval dosing interval = tau (T) FD/T = CpssVd x Kel = Cpavg x Cl_T ^CpssVd = loading dose
Lipophillic Groups
liphophilic unionized nitroglycerine passive diffusion into cell membranes, filtration through glomerular capillaries in kidney, choroid plexus in the brain, sinusoids in the liver obeys first order kinetics (rate or transfer is proportional to concentration gradient) can be applied topically, will absorb through the skin, can go through BBB Vd can exceed total body water AND total body weight due to extensive accumulation in fat
transdermal drugs need to be sufficiently
lipophilic small MW potent
Lipoxin A4, B4
lipoxin arachidonic acid metabolite via lipoxygenase pathway inhibition of inflammation
von Gierke's disease glucose-6-phosphatase glycogen
liver predominates; hepatocytes, renal tubular cells puffy cells filled with glycogen convulsions, hypoglycemia, hepatomegaly, growth retardation, infections, hyperlipidemia, hyperuricemia
tissue damage
lysosomal enzymes, ROS
baroreceptor / vagal reflex
may amplify or oppose the adrenergic receptor mediated effects of adrenergic drugs on HR - systemic admin of NE normally results in a reflex, vagal-mediated *DECREASE* in HR, even though the direct B1-mediated effect of NE is to inc. HR
pathologic findings in CF
meconium ileus peritonitis mucus secretions in pancreatic ducts mucus in lungs (Meconium is the earliest stool of a mammalian infant. Unlike later feces, meconium is composed of materials ingested during the time the infant spends in the uterus: intestinal epithelial cells, lanugo, mucus, amniotic fluid, bile, and water.)
sarcomas
mesenchymal cell malignant neoplasm - fibrosarcoma - leiomyosarcoma - chondrosarcoma - osteosarcoma
Tay-Sachs Disease
missing enzyme: *hexosaminidase* accumulated material: *gangliosides* - microscopic: cytoplasmic vacuoles - EM: lysosomes filled with "onion skin" membranes - tissues involved - CNS; retina (*cherry red spot*), autonomic nerves, heart, liver, spleen, etc. clinical: - hypotonia (=> autonimic nerves) - cherry red spot
convective transport
movement of large molecules from lymphatics into interstitial spaces e.g. for large drugs - administered directly into vasculature b/c can't diffuse or filter rate depends on: - hydrostatic pressure gradient, fluid flow rate into tissue, and on sieving (filtering) effect of paracellular pores - sieving depends on size & shape of pores, and size, shape, and charge of antibody
NEC
necrotizing enterocolitis - indicidence of disease is inversely proportional to gestational age - highest incidence @ lowest age - approx 2500 cases occur annually in US - clinical presentation: ---> abdominal distention ---> absent bowel sounds ---> bloody stools ---> possible perforation (ischemic bowel, pneumatosis intestinalis, distended bowel loops) ?cause --> hyperalimentation? oral feeds? breast feed = reduces?
lidocaine structure/charge
tertiary amine weak base (pka = 8) + @ 7.4
symp & para opposing effects on GI motility
para ACh--> M receptor --> inc. GI motility (contraction) symp NE --> a2 receptor, inhibits parasympathetic ACh transmission (upstream inhibition; ultimately affects end-organ to relax GI motility)
ionizable groups
quaternary ammonium, drugs with carboxylate group or amine group that are charged at physiological pH, at HIGH pH, the carboxylate group is ionized (if pH>pKa). At LOW pH, the amine group is ionized (if pH<pKa) succinylocholine, aspirin (WA), lidocane (WB) will hang out in interstitial spaces, not within cells unless active transport can exhibit structural selectivity, transport can occur against concentration gradient, drugs can compete for binding and inhibit each other ATP dependant: Pgp (p-glycoprotein 1) MDR1 (multidrug resistance protein)-->ABC transporter, transports amphipathic, cationic, neutral substrates...verapamil sensitive. Found in normal cells (protective) and tumor cells, causes resistance to antitumor agents. Nonselective obeys MM kinetics, carrier mechanism can be saturated, becomes a zero order (rate of transport is constant) choroid plexus, cerebral vascular endothelium, proximal renal tubular cell (blood to urine), hepatocyte (blood to bile), tumur cells GI mucosa can act as a barrier for low lipophilicity drugs, carrier mediated extrusion from mucosa into GI lumen, excluded from BBB ~extracellular fluid (17%) urine pH will change amount in urine-->charged groups are trapped can be actively transported into the urine if a substrate for a OATP/OCTP ATP dependant: Organic anion transporter 1 (OAT1), transports organic anionic substrates....probenecid sensitive will not be free filtered at glomerulus if bound to a plasma protein
N-methylnaltrexone u peripheral antagonist
quaternary ammonium; doesn't penetrate BBB help with opoid-induced constipation, reduced gastric emptying (helps with oral medications since most drugs are absorbed in the intestine), and urinary retention
Cl_R
renal clearance = urinary excretion rate / Cp = (amt excreted during collection interval / interval duration) / Cp @ midpoint of interval
what mediators cause retraction of endothelial cells (to start exudate)? how do these compare to vasodilators?
retraction: (* if also vasodilator) - histamine* - leukotrienes (=>cox*) - nitric oxide* - bradykinin* - substance P (stimulates release of vasoactive amines)
GPCRS
s second messengers 7 transmembrane domains, ligand can bind either extracellularly or within transmembrane domain
differentiation of neoplasias
the extent to which neoplastic cells *resemble* the parent cell of origin - well diff = close resemblance to parent cell (least bad) - *grade 1* - poorly diff = more primitive (worst) - *grade 2* - moderately diff = between well and poorly diff - *grade 3* for glandular tissues - the ability to form glands for squamous - the ability to form keratin
metoprolol (esmolol, atenolol) Antagonist B1 selective
treatment of cardiac arrythmias, reducing mortality after MI, maintaining cardiac output and tissue perfusion in shock, treatment of heart failure, treatment of hypertension, angina, stage fright, hyperthyroidism symptoms, migraine prophylaxis, glaucoma management of heart failure bronchoconstriction, bradycardia, exacerbation of angina, fatigue, cold extremities, potentiation of epinephrine vasoconstriction, precipitation of heart failure (if incorrectly used), new onset diabetes
TAT
turnaround time (from specimen draw-->generation of lab result) can be based on specimen transport time, frequency of test running some tests require a fast TAT such as blood gas, whereas others may not such as molecular testing for genetic counseling
vasoactive amines
type of vasodilators - include Histamine and 5HT - *preformed* in cytoplasmic granules - => mast cells, platelets - dilates arterioles & inc. permeability release stimulated by: - physical injury - binding antibodies to mast cells - anaphylatoxins (C3a, C5a) - neuropeptides (i.e. subst P)
VCM tox
vinyl chloride monomer (gas w/ sweet odor) - PVC pipes, flooring effect: liver angiosarcoma mech: processing of metabolites in liver?
• Describe the morphologic changes in coagulation necrosis in myocardial infarction. • Relate these morphologic changes to cellular and subcellular events during necrosis.
• The patient was stable until the morning of hospital day 3 when she developed sudden respiratory distress and hypotension. • An emergency echocardiogram suggested papillary muscle rupture. • The patient was brought to the OR and the papillary muscle was resected with placement of a mitral valve prosthesis. • The patient made a good recovery.
Hepatocye Metabolism of Acetaminophen
•The lab reported that the the patient's acetaminophen level was 293 ug/ml •The blood alcohol level was 20mg% •Toxin screen was otherwise negative
SUMMARY AND RECOMMENDATIONS — Herbal treatments are widely used by patients in the United States and elsewhere. They have the potential for both benefit and harm. (See 'Commonly used herbs and supplements' above.) ● Patients should be asked about use of herbal treatments in a nonjudgmental manner as part of the medication history. (See 'Asking about use' above.)
● Patients can be advised about herbal product use or avoidance based upon a product's quality, efficacy, and safety (table 8). (See 'Advising patients' above.) ● Uncertainty in quality and the relatively few well-designed studies make it difficult for clinicians to proactively recommend herbal therapies for most patients. (See 'Advising patients' above.) ● When patients decide to use herbal therapies, they should be monitored for evidence of benefits and harmful effects, including side effects. (See 'Advising patients' above.) ● We suggest that pregnant and nursing patients be advised to avoid herbal therapies (Grade 2C). (See 'Pregnancy and nursing' above.) ● An option for counseling patients who seek advice about what brand of herbal medicine to use is to recommend brands that have been tested by independent sources such as Consumer Labs (www.consumerlab.com). (See 'Choice of brand' above.)