MLS Chemistry
BNP (brain natriuretic peptide)
BNP (brain natriuretic peptide) is released in response to a variety of cardiac stresses, but most particularly cardiac stretch. It is affected by changes in volume and in cardiac performance. It is a sensitive marker for changes in ventricular physiology.
Which disease/condition is associated with a deficiency in thiamine (vit b1)
Beriberi The clinical condition associated with chronic thiamine (vitamin B1) deficiency is beriberi. Vitamin A deficiency is associated with night blindness. Vitamin D deficiency is associated with rickets. Vitamin C deficiency is associated with scurvy.
How is cortisol controlled?
Blood levels of cortisol vary throughout the day, but generally are higher in the morning when we wake up, and then fall throughout the day. This is called a diurnal rhythm. In people that work at night, this pattern is reversed, so the timing of cortisol release is clearly linked to daily activity patterns. In addition, in response to stress, extra cortisol is released to help the body to respond appropriately. The secretion of cortisol is mainly controlled by three inter-communicating regions of the body: -the hypothalamus in the brain, - the pituitary gland and - the adrenal gland. This is called the hypothalamic-pituitary-adrenal axis. When cortisol levels in the blood are low, a group of cells in a region of the brain called the hypothalamus releases corticotrophin-releasing hormone (CRH) which causes the pituitary gland to secrete another hormone, adrenocorticotropic hormone, into the bloodstream. High levels of adrenocorticotropic hormone are detected in the adrenal glands and stimulate the secretion of cortisol, causing blood levels of cortisol to rise. As the cortisol levels rise, they start to block the release of corticotrophin-releasing hormone (CRH) from the hypothalamus and adrenocorticotropic hormone from the pituitary. As a result, the adrenocorticotropic hormone levels start to drop, which then leads to a drop in cortisol levels. This is called a negative feedback loop.
Which of the following therapeutic drugs increases the force of myocardial muscle contraction?
Digoxin Digoxin inhibits both cellular Na+ efflux, and K+ influx in myocardial cells, which is postulated to enhance movement of calcium ions in the cell, increasing calcium ion availability and improving cardiac contractility. Primidone is a barbiturate used to control seizures. Cyclosporine is an immunosuppressive drug often used to suppress graft rejection of transplanted organs. Disopyramide is an antiarrhythmic agent.
Digoxin
Digoxin is used to treat heart failure and abnormal heart rhythms (arrhythmias).
A patient has a fasting plasma glucose (FPG) performed at an outpatient laboratory. He has fasted as instructed. FPG: 135 mg/dL What does this result indicate and what, if any, further action is recommended by the ADA?
Elevated FPG; needs further evaluation by a repeat or alternative test The result is elevated. Hyperglycemia is demonstrated by this one FPG. The ADA recommends that the hyperglycemia be demonstrated a second time by repeating the FPG or by using one of the other recommended diagnostic tests. Hyperglycemia should be demonstrated a second time by any of the four criteria unless the glucose level is significantly high and diabetes is unquestionable. The four diagnostic creiteria include: HbA1c =6.5% FPG of = 126 mg/dL An oral glucose tolerance test with a 2-hour postload (7g glucose) level of =200 mg/dL Random FPG level of =200 mg/dL and symptoms of diabetes
Which values would be expected with metabolic alkalosis?
Elevated pH, increased bicarbonate, normal PCO2 —————————————————————— When using determining the acid-base status of a person, the parameters that may vary due to conditions of the patient would be the pH (acidosis = < 7.35 or alkalosis = > 7.45), bicarbonate (HCO3-1), and PCO2(partial pressure of carbon dioxide). If the bicarbonate changes, it would be considered metabolic. If the bicarbonate increases, the pH increases and it would be metabolic alkalosis. For example, this could happen through excess administration of sodium bicarbonate. If the bicarbonate decreases, the pH decreases and this would be metabolic acidosis. For example, excessive loss from diarrhea. If the carbon dioxide changes, it would be considered respiratory. A decrease in PCO2 would actually increase the pH and it would be respiratory alkalosis which could be caused by hyperventilation conditions. An increase in PCO2 would actually decrease the pH and it would be respiratory acidosis which could be caused by hypoventilation conditions.
Which of the following analytes will be falsely increased due to hemolysis?
Extreme care should be taken in order to avoid hemolysis of the specimen. When the specimen is hemolyzed, the concentration of analytes is changed and results are inaccurate. Some falsely increased results include potassium, magnesium, iron, lactate dehydrogenase, phosphorus, ammonia, and total protein. Some of the results falsely decreased include red blood cell count, hemoglobin, and hematocrit.
Ferritin
Ferritin is one of the main forms in which iron is stored in the body, the other form is hemosiderin. The concentration of circulating ferritin is proportional to the size of iron stores.
Thyroid (gland)
Found in both women and men, the thyroid controls a person's metabolism. It is located in the front of the neck. This gland secretes hormones that govern many of the functions in your body, such as the way the body uses energy, consumes oxygen and produces heat. Thyroid disorders typically occur when this gland releases too many or too few hormones. An overactive or underactive thyroid can lead to a wide range of health problems. Hormone.com
Testes (gland)
Found in men, this gland produces testosterone, which promotes the growth of the penis as a male gets older as well as facial and body hair. It also deepens the voice of a male at a certain age. Other functions of testosterone include: Maintaining sex drive Promoting production of sperm Maintaining healthy levels of muscle and bone mass
Ovaries (glands)
Found in women, this gland produces eggs and sex hormones—including estrogen, testosterone, and progesterone—which are vital to reproductive organ development, breast development, bone health, pregnancy, and fertility.
A patient who is suspected of having diabetes, has orders for a three-hour glucose tolerance test. The three-hour glucose tolerance test includes?
Four specimens: a fasting blood glucose, a specimen collected at one hour, a second specimen collected at two hours, and a third specimen collected three hours after drinking a 100-gram dose of glucose solution.
Friedewald calculation for LDL
Friedewald calculation for LDL: LDL = total cholesterol - HDL - triglycerides/5 The calculation is considered valid, if the triglyceride value is less than 400 mg/dL.
Which enzyme is responsible for the conjugation of bilirubin?
Glucuronyl transferase is responsible for the conjugation of bilirubin in the liver. When deficiencies exist of this important enzyme, disease states can occur. A deficiency in glucuronosyl transferase is thought to be the cause of Gilbert's syndrome (unconjugated hyperbilirubinemia) Crigler-Najjar syndrome, where this enzyme is completely or mostly absent.
Haptoglobin
Haptoglobin is a glycoprotein which binds free hemoglobin and prevents it from being cleared by the renal system and subsequently preventing iron loss.
renin-angiotensin-aldosterone system
Low blood pressure Low sodium concentration
Which type of lipoprotein transports the MAJORITY of cholesterol to cells for steroid hormone synthesis or cell membrane incorporation?
Low density lipoproteins (LDL) The majority of cholesterol (about 70%) is transported by LDL to the various cells in the body and the rest is transported by HDL through reverse cholesterol transport for excretion purposes, ultimately through bile or bile salts. VLDL transports endogenous products, mostly lipids, whereas chylomicrons transport exogenous (dietary) products (lipids).
Why it's important to centrifuge tubes right away?
Serum/plasma should be removed from the cells as soon as possible after collection. If the specimen is not centrifuged within the first two hours after collection, certain test results may be invalid. Serum/plasma glucose test results may be decreased while lactate dehydrogenase, creatinine, and potassium test results will be increased.
Chem Panels
The Renal Function Panel consists of Glucose, BUN, Creatinine, Sodium, Potassium, Chloride, CO2, Calcium, Albumin, Phosphorus. The Hepatic Function Panel A consists of AST, ALT, Alkaline Phosphatase, Total Protein, Albumin, Total Bilirubin, Direct Bilirubin. The Lipid Panel consists of Cholesterol, Lipoprotein, HDL, Triglycerides. The Electrolyte Panel consists of potassium, sodium, chloride, carbon dioxide. These analytes are also typically ordered within other panels as well, including the basic metabolic and complete metabolic panels.
Calcium regulation
The body maintains very tight control over the calcium circulating in the blood at any given time. The equilibrium is maintained by an elegant interplay of calcium absorbed from the intestines, movement of calcium into and out of the bones, and the kidney's reclamation and excretion of calcium into the urine. If the serum calcium level falls, the parathyroid glands release PTH into the blood and this signals cells in bone (osteoclasts) to release calcium from the bone surfaces. PTH also signals the kidney to reclaim more calcium before it is excreted in the urine and also stimulates synthesis of the active form of vitamin D. There are at least three hormones intimately involved in the regulation of the level of calcium in the blood: parathyroid hormone (PTH), calcitonin and calcitriol (1, 25 dihydroxyvitamin D, the active form of vitamin D). PTH comes from the parathyroid glands located behind the thyroid gland in the lower part of the neck and calcitonin comes from cells in the thyroid gland, both of which monitor and maintain calcium levels in the blood. The active form of vitamin D is synthesized in the kidney under the control of PTH. Special cells that reside in the thyroid gland along with thyroid hormone containing cells release another hormone, calcitonin, into the blood. Calcitonin signals osteoclasts to slow down removal of calcium from bone; this action tends to lower levels of blood calcium. Conversely, shutting off calcitonin allows osteoclasts to get back in business to release needed calcium from bone. The PTH system provides long-term, day-to-day regulation of calcium levels by many hormones working in concert. This hormonal "feedback loop" is governed by the parathyroid glands and the calcitonin-secreting cells of the thyroid gland by their constant monitoring of the blood calcium levels. The body also has a minute to minute regulation of calcium levels from osteocytes in bone—these cells can instantly release needed calcium or instantly stop releasing calcium depending on immediate needs (too little or too much calcium coming into the bloodstream).
Vitamin Deficiency
The clinical condition associated with chronic thiamine (vitamin B1) deficiency is beriberi. Vitamin A deficiency is associated with night blindness. Vitamin D deficiency is associated with rickets. Vitamin C deficiency is associated with scurvy.
A physician calls the lab wanting to order a Hepatitis A IgG test but cannot find the code. What do you tell the physician?
The correct answer is There are no IgG-only tests for Hepatitis A, only a total with/without reflex to IgM. This is because an IgG test only tests for exposure to the virus and cannot determine current or past infection. If a physician is looking for current infection, an IgM test should be ordered. Normally, a total Hep A antibody test will be performed and is positive, will reflex to IgM to look specifically for current infection. Testing does not differentiate specifically IgG from IgM. There are no antigens tests for Hepatitis A, specific antibodies to parts of the virus like with testing for Hepatitis B, and it does not depend on where the patient is coming back from. There are, however, stool antigen test for Hepatitis A as the viral particles are shed in the feces but is not found once liver enzymes reach their peak.
Transferrin
Transferrin is a beta globulin which is involved in iron transport throughout the body.
Which of the following is TRUE of a fully compensated metabolic acidosis?
pH will be normal with a decrease in pCO2 The pH will be normal in a fully compensated form of any alkalosis or acidosis. In this case, the problem is metabolic, meaning there is a decrease in bicarbonate (alkaline) production which has reduced the pH of the blood. To compensate for this, the patient hyperventilates thus reducing the amount of acid, or pCO2 in the system to balance the pH into normal range
Acid Base
negatively charged electrolytes are called anions (Cl-, HCO3-) and those positively charged are called cations (K+, Na+).
How many grams of sodium hydroxide are required to prepare a 200 ml solution of a 10% (weight per volume) solution? (Atomic weights: Na = 23; 0 = 16; H = 1)
% concentration (expressed as a proportion or ratio) x volume needed = mass of reagent to use So... 10% (w/v) solution of sodium hydroxide x 200 mL needed = 20 grams of sodium hydroxide
What is the formula for calculating transferrin saturation (TS)?
(Serum iron/TIBC) X 100
Hyperaldosteronism
-cause high blood pressure, -low potassium levels and - increase in blood volume because of the way the hormone affects the body.
Alpha-fetoprotein
-the BEST screening test for neural tube defects -Alpha-fetoprotein is produced by the fetal liver. It is measured in pregnant women, using maternal blood or amniotic fluid, as a screening test for a subset developmental abnormalities. Abnormally high levels of this substance is associated with defects in the fetal neural tube, while abnormally low levels are associated with the presence of Down' syndrome.
ALP sources
KBLIP - kidney, bone, liver, intestine, placenta
Gestational diabetis
A 29-year old pregnant woman had an outpatient glucose tolerance test. The patient was given a 100-gram dose of glucose and the following values were obtained: Fasting = 110 mg/dL 1 hr. = 188 mg/dL 2 hr. = 175 mg/dL 3 hr. = 143 mg/dL The MOST likely interpretation of this glucose tolerance would be: GD The screening and diagnosis of gestational diabetes mellitus (GDM) is performed on pregnant patients between 24 to 28 weeks of gestation. A 50 g oral glucose load is given to the patient and plasma glucose is measured at 1 hour. If the screening glucose test is greater or equal to 140 mg/dL, glucose tolerance test is indicated. Normal blood values for a 100-gram oral glucose tolerance test used to screen for gestational diabetes are as follows: Fasting: less than 95 mg/dL 1 hour: less than 180 mg/dL 2 hour: less than 155 mg/dL 3 hour: less than 140 mg/dL At least two of the patient's values must meet or exceed the result limits listed above for GDM to be diagnosed. In our case, all of the patient's exceeded the limits, therefore it can be concluded that the patient has GDM.
Which of the following analytes would be INCREASES due to delay in centrifugation?
AST The specimen should not be delayed for more than two hours prior to centrifugation because some of the analyte levels (such as glucose, ionized calcium, bicarbonate, folate, etc.) may be falsely decreased due to cellular consumption or falsely increased (such as potassium, ALT, AST, creatinine, etc.) because they are released over time from cells into serum or plasma.
Acid-Base Reference Range
Acid bases Reference Range: pH = 7.35-7.45 pCO2 = 35-45 mm Hg HCO3- = 22-29 mmol/L pO2 = 85-105 mm Hg
What happens if I have too little cortisol?
Addison's Disease Too little cortisol may be due to a problem in the pituitary gland or the adrenal gland (Addison's disease). The onset of symptoms is often very gradual. Symptoms may include fatigue, dizziness (especially upon standing), weight loss, muscle weakness, mood changes and the darkening of regions of the skin. Without treatment, this is a potentially life-threatening condition.
Albumin
Albumin is a nonglycosylated protein synthesized in the liver whose function is to transport a large number of compunds such as free fatty acids, bilirubin, calcium, hormones, drugs, etc.
What is the effect of aging with the hormones of the endocrine system?
Aldosterone decreases and norepinephrine increases With the endocrine system, adrenocorticotropic hormone and cortisol levels typically do not change with age and epinephrine levels remain stable. Aldosterone levels may decline, which can contribute to orthostatic hypotension, or a drop in blood pressure upon standing. Norepinephrine secretion generally increases, which contributes to systemic vasoconstriction and decrease in myocardial relaxation.
Amitriptyline
Amitriptyline is an antidepressant medication.
Therapeutic Drug
Amphetamine and methamphetamine are therapeutic drugs used for narcolepsy and attention deficit disorders. Digoxin (Lanoxin) is a cardiac glycoside used in the treatment of congestive heart failure. Dilantin (Phenytoin) is a common therapeutic agent used in the treatment of seizure disorders. Phenobarbital (Luminol or Solfoton) is a slow-acting barbiturate that effectively controls several types of seizures.
What is Angiotensin?
Angiotensin consists of a group of hormones that are part of the renin-angiotensin system. To create angiotensin, the liver first creates a protein called angiotensinogen. This protein is broken up by renin, which comes from the kidney. This forms angiotensin I. Angiotensin I passes through the bloodstream, where it turns into angiotensin II, which is the primary form of the hormone that affects blood pressure and other areas of the body. How Does Angiotensin Work? Angiotensin, specifically angiotensin II, binds to many receptors in the body to affect several systems. It can increase blood pressure by constricting the blood vessels. It can also trigger thirst or the desire for salt. Angiotensin is responsible for the release of the pituitary gland's anti-diuretic hormone. In the adrenal glands, angiotensin stimulates aldosterone production. This hormone causes the body to retain sodium. In the kidneys, sodium retention triggered by angiotensin changes the way the blood is filtered, causing increased water re-absorption to increase the volume of blood. This, again, increases blood pressure. While angiotensin has a complex series of effects on the body, the primary results are higher blood volume, blood pressure and sodium content. Potential problems with angiotensin People can struggle with angiotensin in one of two ways: Too much angiotensin can cause the body to retain too much fluid or to have elevated blood pressure levels not caused by other problems. High angiotensin levels can also cause the heart to grow, leading to heart failure. Angiotensin blockers can help in these situations by blocking the receptor sites that take up angiotensin, but this can lead to too much potassium retention. Working with an endocrinologist is important to ensure the body remains healthy while balancing angiotensin levels. Low angiotensin levels can also be problematic. Angiotensin deficiency can prevent the regulation of blood volume and pressure, increase retention of potassium, and lead to a loss of sodium and more urine output, as the body releases needed fluid. This causes a lower blood pressure.
Which of the following apolipoproteins contributes the greatest mass to the structure of high-density lipoprotein (HDL)?
Apolipoprotein A (Apo A) contributes the greatest mass to the structure of HDL. Apo A-1 and Apo A-II both are part of the HDL structure. Apo A-1 has a molecular weight of 28,000 kD while Apo A-II has a molecular weight of 17,400 kD. Apolipoprotein B (Apo B) is a key structural component of chylomicrons, VLDL, and LDL. Apolipoprotein C is structural component to chylomicrons, VLDL, and LDL. While it is a structural component of HDL, it is a smaller part of the structure of HDL than Apo A. Apolipoprotein G does not exist.
Cardiac Markers
B-type natriuretic peptide (BNP) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) are currently used to differentiate heart failure from lung disease. Troponin I (TnI) and troponin T (TnT) are currently used to diagnose acute coronary syndrome and acute myocardial infarction. Myoglobin and lactate dehydrogenase (LD) are no longer used or are less commonly used as biomarkers for cardiac damage. High sensitivity C-reactive protein (hsCRP) and homocysteine are used for cardiovascular risk stratification.
CA-125
CA-125 - ovarian and endometrial carcinomas.
Cancer markers
CA125 is an antigen present on approximately 80% of ovarian carcinomas. CA125 is often elevated in patients with ovarian cancer and its concentration follows the course of disease. It is important to note that CA125 is not completely specific for ovarian carcinomas. It can be found in increased levels in other cancers including endometrial, pancreatic, lung, breast, and colon cancer, along with other conditions such as pregnancy. CEA (carcinoembryonic antigen) is typically utilized for colon cancer screening and prognosistic purposes. CA19-9 is typically found in increased levels in conditions such as gastrointestinal adenocarcinoma and pancreatic cancers. PSA (prostate specific antigen) is specific to the prostate gland. This tumor marker is increased in conditions such as prostate cancer and prostatitis.
CA15-3 and CA27.29
CA15-3/CA27.29 both of these tumor markers are associated with breast cancer.
CSF glucose vs serum
CSF glucose value is 62 mg/dL. What would you estimate the serum glucose? CSF glucose is roughly estimated to be about 2/3 of the serum glucose level in mg/dL. Therefore: 62 mg/dL = 2/3 x serum glucose serum glucose = 62 mg/dL x 3/2 (62 x 3 = 186/2 = 93) serum glucose = 93 mg/dL
Cardiac markers
Cardiac markers Myoglobin - 1st cardiac marker to elevate after MI : 2-4 hours; peak at 6-9 hours post MI Troponin - 2nd cardiac marker elevated @ 3-12 hours; peak @ 12-24 hrs post MI LD - 8-12 hours after MI; peak @ 24-48 hrs post MI CK - 4-6 hours after MI; peak at 24-36 hours post MI
Cortisol Reference Range
Cortisol Reference intervals for an adult are as follows: 5-23 µg/dL at 8:00 a.m. 3-16 µg/dL at 4:00 p.m. <50% of 8:00 a.m. values at 8:00 p.m Addison's disease will show lower levels of cortisol and other steroid hormones without fluctuation in the day/night. Cushing's syndrome is associated with high levels of cortisol throughout the day and night. Pheochromocytoma is associated with an increased release of epinephrine and norepinephrine.
What is cortisol?
Cortisol is a steroid hormone, one of the glucocorticoids, made in the cortex of the adrenal glands and then released into the blood, which transports it all round the body. Almost every cell contains receptors for cortisol and so cortisol can have lots of different actions depending on which sort of cells it is acting upon. These effects include controlling the body's blood sugar levels and thus regulating metabolism, acting as an anti-inflammatory, influencing memory formation, controlling salt and water balance, influencing blood pressure and helping development of the foetus. In many species cortisol is also responsible for triggering the processes involved in giving birth.
What happens if I have too much cortisol?
Cushing Syndrome Too much cortisol over a prolonged period of time can lead to a condition called Cushing's syndrome. This can be caused by a wide range of factors, such as a tumour that produces adrenocorticotropic hormone (and therefore increases cortisol secretion), or taking certain types of drugs. The symptoms include: rapid weight gain mainly in the face, chest and abdomen contrasted with slender arms and legs a flushed and round face high blood pressure osteoporosis skin changes (bruises and purple stretch marks) muscle weakness mood swings, which show as anxiety, depression or irritability increased thirst and frequency of urination.
Increased concentrations of alpha-fetoprotein (AFP) in adults are MOST characteristically associated with:
Hepatocellular carcinoma Alpha-fetoprotein is a substance typically used in the triple test during pregnancy and for screening chronic liver disease patients for hepatocellular carcinoma. AFP is one of the oncofetal proteins which are produced in high concentration during fetal life. AFP is produced by the fetal yolk sac and liver. Oncofetal proteins usually disappear or are reduced to very low concentrations after birth. Increased alpha-fetoprotein levels in adults is usually associated with hepatocelluar carcinoma, as it is a tumor maker in this population. Alcoholic cirrhosis, chronic active hepatitis, and multiple myeloma would not cause an increase in serum AFP.
Which lipid abnormality is most closely linked to heart disease?
Hypercholesterolemia Hypercholesterolemia is the lipid abnormality most closely linked to heart disease. One form of the disease, which is associated with genetic abnormalities that predispose affected individuals to elevated cholesterol levels, is called familial hypercholesterolemia. Hypobetalipoproteinemia is associated with isolated low levels of LDL-C as a result of a defect in the Apo B gene, but it is not generally associated with coronary heart disease. Hypertriglyceridemia can be a consequence of genetic abnormalities or a result of hormonal abnormalities associated with the pancreas, adrenal glands, and pituitary, or of diabetes mellitus or nephrosis. The National Cholesterol Education Program has identified borderline high triglycerides as levels of 150-200 mg/dL, high as 200-500 mg/dL, and very high as > 500 mg/dL. Hypertriglyceridemia has not been shown as an independent risk factor for coronary heart disease. Abetalipoproteinemia, which is due to a defect in the microsomal transfer protein used in the synthesis and secretion of VLDL, will present with low LDL and apo B-like hypobetalipoproteinemia. It is an autosomal recessive disorder and like hypobetalipoproteinemia patients, they are not at an increased cardiovascular risk.
A patient has the following test results: Increased serum phosphorus level, decreased serum calcium level, and decreased serum parathyroid hormone (PTH) level. This patient MOST likely has:
Hypoparathyroidism The decreased serum PTH level indicates that the parathyroid gland is not secreting this hormone adequately. This condition is called hypoparathryroidism, with inadequte parathyroid hormone production (decreased), decreased calcium, and increased phosphorus. Hyperparathyroidism is a condition where the patient produces increased levels of PTH. Hypercalcemia is a condition where a patient's calcium levels are increased, in our case the calcium levels were low. Hypokalemia is a condition where the patient's potassium levels are decreased, there is no mention of patient's potassium levels in the question.
Calcium Reference Range
If you have hyperparathyroidism (a bad parathyroid gland), you should get it removed. You will live longer and feel better. Humans don't like high calcium! If your lab tests say that having calcium levels up to 10.4 or even 10.6 are normal, then that lab is including children and teenagers into their normal range. It is normal for children and teenagers to have blood calcium levels up to 10.4 or even 10.5 on occasion. (They are still building bones!). It is normal for young adults in their twenties to have calcium levels up to 10.3 or 10.4. Once you are over 40, it is OK to have an occasional calcium level up to 10.2 (not above). If you are over 40, then it is not normal to have frequent or persistent calcium levels above 10.1. If your doctor says that it is OK for you because the lab values say this is OK, then you tell them "Not True". That normal range includes kids and that is not the normal range for adults over 40. If you are over 40 and have persistent calcium levels above 10.1, then you need to ask about being tested for hyperparathyroidism
Patients who develop severe sepsis or septic shock commonly have __________ plasma lactate values
Increased lactic acid This is considered Type B lactic acidosis and is of metabolic origin. Other causes for Type B lactic acidosis include: -diabetes mellitus, -leukemia, -liver or renal disease, and poisoning with ethanol, methanol, or salicylate.
Which of the following medications is considered an antineoplastic drug?
Methotrexate Methotrexate (Otrexup, Rasuvo) is one of the few antineoplastic drugs in which TDM may offer some benefit to determining a therapeutic regimen. Cyclosporine (Gengraf, Neoral, Sandimmune) is a cyclic polypeptide that has potent immunosuppressive activity. Clozapine (Clozaril, FazaClo) is an antipsychotic used in the treatment of otherwise treatment-refractory schizophrenia. Tacrolimus FK-506 (Astagraf, Envarsus, Hecoria, Prograf) is an orally administered immunosuppressive drug that is 100 times more potent than cyclosporine.
Monoclonal gammopathies are associated with ?
Monoclonal gammopathies are associated with a clonal process that is malignant or potentially malignant. In contrast, polyclonal gammopathies may be caused by any reactive or inflammatory process, and they usually are associated with nonmalignant conditions.
What is Aldosterone?
Most individuals have never heard about this particular hormone, yet it plays an important role in cardiovascular health. Aldosterone is produced in the cortex of the adrenal glands, which are located above the kidneys. Understanding this hormone will help you understand your body better, and help you take measures to ensure optimal health. Aldosterone affects the body's ability to regulate blood pressure. It sends the signal to organs, like the kidney and colon, that can increase the amount of sodium the body sends into the bloodstream or the amount of potassium released in the urine. The hormone also causes the bloodstream to re-absorb water with the sodium to increase blood volume. All of these actions are integral to increasing and lowering blood vessels. Indirectly, the hormone also helps maintain the blood's pH and electrolyte levels. Aldosterone is closely linked to two other hormones: renin and angiotensin, which create the renin-angiotensin-aldosterone system. This system is activated when the body experiences a decrease in blood flow to the kidneys, such as after a drop in blood pressure, or a significant drop in blood volume after a hemorrhage or serious injury. Renin is responsible for the production of angiotensin, which then causes the release of aldosterone. Once the body is rehydrated and has proper salt levels in the blood, renin levels fall, and aldosterone levels lower as a result.
Proteins in a buffer that sets the pH at 8.6 will become ___________ charged and migrate to the ____________.
Negatively; Anode The isoelectric point (pI) of most proteins is between pH 4.0 and 7.5. A molecule in a solution above its pI will take on a negative charge. Negatively charged molecules in an electric field will migrate to the positive electrode, the anode.
Which of the following GFR (glomerular filtration rate) values is considered to be in renal failure?
Normal GFR rates should be above 90 mL/min. When the kidneys become damaged, the filtration ability will start to decrease, keeping more waste products and toxins in the body. The lower the number for the GFR, the more damaged the kidneys are. Values above 90 mL/min are normal while values between 15-60 mL/min are considered to have kidney damage; values
A male patient's urea nitrogen value is 15 mg/dL and his creatinine is 5 mg/dL. If this patient is not undergoing dialysis, what conclusion would you draw from these results?
One of the values is in error The patient's urea nitrogen is within normal range (6-20 mg/dL) while the creatinine is about five times the upper normal range (0.6-1.2 mg/dL). Gross elevations in creatinine are almost always accompanied by elevations in urea nitrogen when there is kidney impairment. Urea nitrogen to creatinine ration is normally 10:1 to 20:1, in our case is 3:1 which is abnormally low. Therefore, either the urea nitrogen or creatinine value in this case is incorrect. Both tests should be repeated.
There are many reasons why a patient would develop hypomagnesemia such as reduced intake, decreased absorption, and increased excretion.
Pancreatitis will cause decreased absorption of magnesium leading to hypomagnesemia. Hypermagnesemia can be caused by decreased excretion, increased intake, or for miscellaneous reasons. Hypothyroidism, hypoaldosteronism, and bone carcinoma are all considered causes of hypermagnesemia (elevated serum magnesium levels).
A physician is evaluating a 45-year-old obese male for diabetes and orders a plasma glucose test at time of evaluation and a HbA1C one week later. The patient has a family history of diabetes and currently exhibits symptoms of diabetes. What would be the best course of action if these are the blood glucose test results? Casual Plasma Glucose: 208 mg/dL HbA1C one week later: 7.2%
Patient meets criteria for diagnosis of diabetes A casual plasma glucose = 200 mg/dL on a patient with symptoms and a HbA1C = 6.5% meet diagnostic criteria for diabetes. Hyperglycemia should be demonstrated a second time by any of the four diagnostic creiteria below: HbA1c =6.5% FPG of = 126 mg/dL An oral glucose tolerance test with a 2-hour postload (7g glucose) level of =200 mg/dL Random FPG level of =200 mg/dL and symptoms of diabetes
Phenobarbital
Phenobarbital is a barbiturate which is used to help prevent seizures.
Drugs
Phenobarbital is a slow-acting barbiturate that is used to control seizures. Lithium is an antidepressant. Gentamicin is an antibiotic from the aminoglycosides family. Other examples include tobramycin, amikacin, and kanamycin. Tacrolimus is an immunosuppressive drug.
Follicle stimulating hormone (FSH) is produced by?
Pituitary The pituitary gland produces FSH. The adrenal cortex produces corticosteroid hormones, androgens, aldosterone, etc. The adrenal medulla produces catecholamines such as epinephrine and norepinephrine. The thyroid gland produces thyroid hormones such as T3 and T4.
It is important to specify if a blood specimen is a capillary specimen rather than a venous specimen. How will the following laboratory results be affected if a capillary specimen is tested?
Potassium, calcium, and total protein are lower in capillary specimens, where glucose is typically higher than in venous blood. Capillary blood obtained for laboratory testing is significantly different from the usual venous blood tested. It is a mixture of venous, arterial, and capillary blood as well as interstitial and cellular fluids. Because of this mixture, capillary blood more closely resembles arterial rather than venous blood and the reference values will differ. Analytes such as potassium, calcium, and total protein are lower in capillary specimens, where glucose is typically higher than in venous blood. Therefore, it is extremely important a notation is made on the requisition slip to inform the person performing the testing that the blood is capillary and not venous.
Hypoaldosteronism
Primary adrenal insufficiency, a disease that causes a general loss of adrenal function, can be a cause. Patients with primary adrenal insufficiency cause: -low levels of aldosterone - low blood pressure - increased potassium levels - lethargy.
hs-CRP
Ranges of hs-CRP in prediction of risk for CVD are: <1.0 mg/L Low CVD risk 1.0-3.0 mg/L Average risk for CVD >3.0 mg/L High risk for future CVD If results are >10.0 mg/L, the patient should be evaluated for an acute inflammatory condition.
A young man is experiencing difficult breathing after fainting. The physician orders an arterial blood gas analysis which shows the following results: pH = 7.25 pCO2 = 62 mmHg pO2 = 70 mmHg HCO3- = 23 mmol/L Which condition is most likely afflicting this patient?
Respiratory acidosis Judging by the pH, which is acidic, this patient is experiencing acidosis. Recall that the reference range for blood pH is 7.35-7.45. The patient's carbon dioxide (pCO2) level is increased while the bicarbonate (HCO3-) level is still within reference range. This indicates that the acidosis is respiratory in nature. The fact that the bicarbonate is not increased in response to the increase in acid, indicates that the respiratory acidosis is uncompensated. Reference Range Recap: pH = 7.35-7.45 pCO2 = 35-45 mm Hg HCO3- = 22-29 mmol/L pO2 = 85-105 mm Hg
The Endocrine System
The endocrine system is a series of glands that produce and secrete hormones that the body uses for a wide range of functions. These control many different bodily functions, including: Respiration Metabolism Reproduction Sensory perception Movement Sexual development Growth Hormones are produced by glands and sent into the bloodstream to the various tissues in the body. They send signals to those tissues to tell them what they are supposed to do. When the glands do not produce the right amount of hormones, diseases develop that can affect many aspects of life. THE MAIN HORMONE-PRODUCING GLANDS ARE: Hypothalamus: The hypothalamus is responsible for body temperature, hunger, moods and the release of hormones from other glands; and also controls thirst, sleep and sex drive. Pituitary: Considered the "master control gland," the pituitary gland controls other glands and makes the hormones that trigger growth. Parathyroid: This gland controls the amount of calcium in the body. Pancreas: This gland produces the insulin that helps control blood sugar levels. Thyroid: The thyroid produces hormones associated with calorie burning and heart rate. Adrenal: Adrenal glands produce the hormones that control sex drive and cortisol, the stress hormone. Pineal: This gland produces melatonin which affects sleep. Ovaries: Only in women, the ovaries secrete estrogen, testosterone and progesterone, the female sex hormones. Testes: Only in men, the testes produce the male sex hormone, testosterone, and produce sperm.
HA1c formula
The formula for conversion of hemoglobin A1C (HbA1C) to glucose in mg/dL is eAG = (28.7 x A1C) - 46.7. The HbA1C measured on a patient is reported as 7.5%. What would be reported as the estimated average glucose (eAG) for this % A1C (rounded to the nearest whole number)? The eAG for a HbA1C of 7.5% would be reported as 169 mg/dL. ————————————————- Remember, the formula for conversion of HbA1C to glucose in mg/dL is eAG = (28.7 x A1C) - 46.7. So, in this case, the calculation is: eAG = (28.7 x 7.5) - 46.7 = 168.55 mg/dL or 169 mg/dL if rounded to the nearest whole number.
Hypothalamus (gland)
The hypothalamus is in control of pituitary hormones by releasing the following types of hormones: Thyrotrophic-releasing hormone Growth hormone-releasing hormone Corticotrophin-releasing hormone Gonadotropin-releasing hormone These hormones regulate body temperature, appetite and weight, mood, sex drive, sleep, and thirst.
Pancreas (gland)
The main function of the pancreas is to maintain healthy blood sugar levels. It is a large gland located behind the stomach. It produces insulin, glucagon, and other hormones. Diabetes occurs when the pancreas does not produce enough insulin or when the body doesn't use insulin properly (called insulin resistance).
pH alteration of normal blood in a closed vessel standing at 37oC for 1 hour is approximately:
The pH of freshly drawn blood decreases at a rate of 0.04 to 0.08 pH units/hour at 37oC, but only 0.02 to 0.03 pH units/hour at 22oC, and <0.01 pH units/hour at 4oC.
According to the American Diabetes Association recommendations, which of the following statements is TRUE with regards to the following findings? Fasting glucose = 130 mg/dL 2-hour post prandial glucose = 210 mg/dL
The patient may be diagnosed as having diabetes mellitus The American Diabetes Association recommends that the diagnosis of diabetes mellitus be based on two fasting plasma glucose levels of 126 mg/dL (7.0 mmol/L) or higher. Other options for diagnosis include two two-hour postprandial plasma glucose (2hr PPG) readings of 200 mg/dL (11.1 mmol/L) or higher after a glucose load of 75 g or two casual glucose readings of 200 mg/dL or higher. Measurement of the fasting plasma glucose level is the preferred diagnostic test, but any combination of two abnormal test results can be used.
Pineal (gland)
The pineal gland releases melatonin, which helps the body recognize when it is time to go to sleep. Researchers continue to learn more about this gland.
Pituitary Gland
The pituitary gland is a tiny organ, the size of a pea, found at the base of the brain. As the "master gland" of the body, it produces many hormones that travel throughout the body, directing certain processes or stimulating other glands to produce other hormones.The pituitary gland makes or stores many different hormones. The following hormones are made in the anterior (front part) of the pituitary gland: PROLACTIN This hormone stimulates breast milk production after childbirth. When prolactin is high, it affects the hormones that control the ovaries in women and testes in men. As a result, high prolactin can affect menstrual periods, sexual function and fertility. GROWTH HORMONE (GH) This hormone stimulates growth in childhood and plays a role in maintaining healthy muscles and bone and well-being in adults. It also affects fat distribution in the body. Too much growth hormone causes a disease that is called acromegaly. In children, too much growth hormone causes excessive growth, called gigantism. ADRENOCORTICOTROPIN (ACTH) This hormone stimulates the production of cortisol by the adrenal glands—small glands that sit on top of the kidneys. Cortisol, a "stress hormone," is needed for our survival. It helps maintain blood pressure and blood glucose (sugar) levels, and is produced in larger amounts when we're under stress, especially during illness, surgery, or after injury. Too much ACTH will result in too much cortisol production; this is called Cushing's syndrome or Cushing's disease. Low ACTH will result in low cortisol, called adrenal insufficiency. THYROID-STIMULATING HORMONE (TSH) This hormones stimulates the thyroid gland to produce thyroid hormones, which regulate the body's metabolism, energy balance, growth, and nervous system activity. Too much TSH is rare and will cause hyperthyroidism (too much thyroid hormone). Lack of TSH results in hypothyroidism (not enough thyroid hormone). LUTEINIZING HORMONE (LH) This hormone stimulates testosterone production in men and egg release (ovulation) in women FOLLICLE-STIMULATING HORMONE (FSH) This hormone promotes sperm production in men and stimulates the ovaries to produce estrogen and develop eggs in women. LH and FSH work together to enable normal function of the ovaries and testes. Problems with these hormones affects menstrual periods in women and fertility and sexual function in both women and men. The following hormones are stored in the posterior (back part) of the pituitary gland: ANTIDIURETIC HORMONE (ADH) This hormone is also called vasopressin, it regulates water balance in the body and sodium levels in the blood. It conserves body water by reducing the amount of water lost in urine. Lack of ADH causes increased urination and thirst, a condition that is called diabetes insipidus . OXYTOCIN This hormone causes milk to flow from the breasts in breastfeeding women, and may also help labor to progress. Oxytocin may also play an important role in human behavior and social interaction and may promote bonding between a mother and her child.
Electrophoresis band: The globulins are classified by their banding pattern (with their main representatives): The alpha (α) band consists of two parts, 1 and 2: α1 - α1-antitrypsin, α1-acid glycoprotein. α2 - haptoglobin, α2-macroglobulin, α2-antiplasmin, ceruloplasmin. The beta (β) band - transferrin, LDL, complement The gamma (γ) band - immunoglobulin (IgA, IgD, IgE, IgG and IgM). Paraproteins (in multiple myeloma) usually appear in this band.
The proteins included in the albumin band include albumin, transthyretin (also referred to as prealbumin), and retinol-binding protein (RBP). RBP is a small protein that binds retinol (Vitamin A). It is transported bound to prealbumin (transthyretin). Transthyretin, also known as prealbumin, transports thyroid hormones. Albumin transports many compounds and maintains oncotic pressure.
Uric acid is the final breakdown product of what two purines?
The purines adenine and guanine are broken down into uric acid. Cytosine and thymine are pyrimidines which are mostly broken down into ammonia, carbon dioxide and water, but not into uric acid.
Delay in centrifugation (>2 hrs)
The specimen should not be delayed for more than two hours prior to centrifugation because some of the analyte levels (such as glucose, ionized calcium, bicarbonate, folate, etc.) may be falsely decreased due to cellular consumption or falsely increased (such as potassium, ALT, AST, creatinine, etc.) because they are released over time from cells into serum or plasma.
Theophylline
Theophylline belongs to a class of medications called bronchodilators, used in treating asthma and other airway diseases.
Metabolic Syndrome
There are five basic parameters described below as metabolic risk factors. A patient must have at least three of the five risk factors to be diagnosed with metabolic syndrome. 1. A large waistline. In women, =35 in. (88 cm); in men, =40 in. (102 cm) 2. High triglyceride level, =150 mg/dL 3. High fasting blood glucose, =100 mg/dL 4. Low HDL cholesterol. In women, <50 mg/dL; in men, <40 mg/dL 5. High blood pressure, that is, =130/85 mm Hg
Parathyroid (gland)
This gland is vital to proper bone development because it helps control both calcium and phosphorous levels in the body. The parathyroid gland is actually a group of four small glands located behind the thyroid gland.
Adrenal (gland)
This gland produces androgens and cortisol. It helps to control blood sugar. In addition, also helps your body do the following: Promoting proper cardiovascular function Helps in how we respond to stress Properly utilizing carbohydrates and fats Helps distribute stored fat Gives you body odor and pubic hair Promotes healthy gastrointestinal functions Learn more about adrenal disorders that can be caused by too much or too little of a particular hormone.
A physician discusses weight with an overweight 60-year-old female at her yearly physical appointment. The female exercises regularly and eats healthy most of the time. The physician suggests she decrease carbohydrate intake and decrease portion size at meals. Review patient vital signs and laboratory assay results to decide if a diagnosis of metabolic syndrome is appropriate using the NCEP: ATP III Diagnostic Criteria shown on the right. Height: 5' 7' Weight: 192 lbs BMI: 30.1 Waist Circumference: 37 inches Blood Pressure: 108/70 Fasting Blood Glucose: 92 mg/dL Total Cholesterol: 172 mg/dL LDL-C: 112 mg/dL HDL-C: 46 mg/dL Triglycerides: 70 mg/dL hs-CRP: <1.0 mg/L Which of these statements regarding this patient is true?
This patient does not meet the criteria for diagnosis of metabolic syndrome. According to the NCEP: ATP III diagnostic criteria, this patient does not have metabolic syndrome. She has only two parameters outside the criteria limits: waist circumference and HDL-C. She does need to lose weight though because she does seem to have increased upper body fat according to the waist circumference measurement. This may eventually cause an increased triglyceride, increased blood glucose, and/or hypertension and metabolic syndrome diagnosis along with an increased risk for cardiovascular disease.
Cardiac biomarkers (AMI infarction)
Troponin I (TnI) - 7-14 days elevated Troponin T (TnT)- 8-21 days elevated with an initial elevation within 3-12 hours after onset of myocardial necrosis. Lactic dehaydrogenase (LD) - elevated up to a week Creatine Kinase MB (Ck-mb) - return to normal in 48-96 hrs CK-MB is back to normal range in 48-96 hours. Myoglobin returns to normal range within 24-36 hours rises within 1 - 3 hours after chest pain, peaks in 2 - 6 hours, and is usually normal within 24 hours.
An obese adult with premature arteriosclerosis is seen in the clinic. When her serum is tested no chylomicrons are present, LDL levels are normal, and VLDL levels are increased. There is an increase in triglycerides and slight increase in cholesterol. Lipoprotein electrophoresis reveals a heavy pre-beta band. She has no skin rash and uric acid is increased. This patient most likely has what type of hyperlipoproteinemia?
Type IV Based on the information provided, the patient has hyperlipoproteinemia type IV which is associated with high triglycerides and increased VLDL. It is also known as hypertriglyceridemia. Type I hyperlipoproteinemia is a form of hyperlipoproteinemia associated with deficiencies of lipoprotein lipase. Hyperlipoproteinemia type II is the most common form and is classified into type IIa and type IIb, depending on whether there is elevation in the triglyceride level in addition to LDL cholesterol. Hyperlipoproteinemia type III is associated with high chylomicrons and IDL. Hyperlipoproteinemia type V is similar to type I, but with high VLDL in addition to chylomicrons.
Glucuronic acid is used in the liver for conjugating what compound from hemoglobin degradation?
Unconjugated bilirubin Bilirubin is the breakdown product of hemoglobin degradation. Unconjugated bilirubin is not water soluble and is transported to the liver attached to albumin, where it is conjugated with glucuronic acid to become water soluble, or conjugated bilirubin, before excretion into bile. Urobilinogen is is the breakdown product of bilirubin by intestinal bacteria, which in turn is then oxidized to urobilin, the orange/brown pigment that gives stool its color.
Calcitonin and PTH in Calcium
What is calcitonin? Calcitonin is a hormone that is produced in humans by the parafollicular cells (commonly known as C-cells) of the thyroid gland. Calcitonin is involved in helping to regulate levels of calcium and phosphate in the blood, opposing the action of parathyroid hormone. This means that it acts to reduce calcium levels in the blood. However, the importance of this role in humans is unclear, as patients who have very low or very high levels of calcitonin show no adverse effects. Calcitonin reduces calcium levels in the blood by two main mechanisms: It inhibits the activity of osteoclasts, which are the cells responsible for breaking down bone. When bone is broken down, the calcium contained in the bone is released into the bloodstream. Therefore, the inhibition of the osteoclasts by calcitonin directly reduces the amount of calcium released into the blood. However, this inhibition has been shown to be short-lived. It can also decrease the resorption of calcium in the kidneys, again leading to lower blood calcium levels.
Glomerular filtration rate
What is the glomerular filtration rate for a patient with a serum creatinine of 2 mg/dL, if the urine creatinine was 124 mg/dL and the urine volume was 2.2 L/24 hrs? One method of calculating a glomerular filtration rate is using creatinine and urine volume to determine creatinine clearance. The equation is as follows: Creatinine Clearance = (urine creatinine X urine flow rate) / plasma creatinine; where urine flow rate = volume in mL /24 hours x h/60 min) In this case = creatinine clearance = 124 X (2200/24 x hour/60) / 2 = 94.7 or 95 mL/min
What are the expected results of the laboratory markers in iron deficiency anemia?
With iron deficiency anemia, the expected results would show decreased serum iron, increased transferrin, decreased ferritin, decreased percent saturation, and increased total iron binding capacity. With malnutrition, the expected results would show decreased serum iron, decreased transferrin, decreased ferritin, variable percent saturation, and decreased total iron binding capacity. With chronic infection, the expected results would show decreased serum iron, decreased transferrin, increased ferritin, decreased percent saturation, and decreased total iron binding capacity. With chronic anemia, the expected results would show decreased serum iron, normal or decreased transferrin, normal or increased ferritin, decreased percent saturation, and normal or decreased total iron binding capacity.
Hypoaldosteronism
a disease that causes a general loss of adrenal function, can be a cause. Patients with primary adrenal insufficiency causing low levels of aldosterone may experience low blood pressure, increased potassium levels, and lethargy.
Which cardiac biomarker is a regulator of myocyte contraction?
cTnT Troponin is a complex of three proteins, TnT, TnI, and TnC, that help regulate striated muscle contraction. TnT and TnI have cardiac specific isoforms, cTnT and cTnI respectively, which are involved specifically in myocyte contraction. Because of their cardiac specificity, quick release during myocardial infarction (MI), and prolonged elevation in the serum (more than one week), they are great biomarlers for MI.
Hyperaldosteronism
caused by small, benign tumors on the adrenal glands. cause high blood pressure, low potassium levels and an abnormal increase in blood volume because of the way the hormone affects the body.
Which of the following represents a diagram of a spectrophotometer?
light source - monochromator - cuvette - detector - readout A light source is used to emit light through a sample for measurement in spectrophotometry. The monochromator selects a narrow band of light that can pass through which will reach the sample cuvette. The detector detects how much light was reflected from or transmitted through the sample. Finally, the intensity of the transmitted light is measured with a photodiode or other light sensor/detector, and the transmittance value for this wavelength is then compared with the transmission through a reference sample, allowing for the readout of the result.
