Toxicology Final Questions
A high urinary pH would favour the excretion of a) organic acids b) organic bases c) neutral organic compounds d) none of the above
A
A noncompetitive heterogeneous immunoassay uses a. excess reagent and requires a separation step b. limited reagent and does not require a separation step с. excess reagent and does not require a separation step d. limited reagent and requires a separation step
A
All of the following are associated with necrosis except a) requirement of ATP b) cell swelling c) association with an inflammatory response d) initiation by plasma membrane permeability changes
A
All of the following are true of aromatic amines except a) they are ultimate carcinogens. b) aniline dyes are examples. c) they are associated with bladder cancer. сег. d) they form reactive metabolites after Phase 1 biotransformation.
A
An increase in free drug concentration will a) increase the pharmacological effect b) decrease the toxic effect c) decrease the amount of drug filtered at the glomerulus d) none of the above
A
Assays that detect antibody-antigen complex formation indirectly by detecting labels that have been coupled to one of the reactants are known as a. labeled immunoassays b. non-labeled immunoassays c. general immunoassays d. none of the above
A
Carbamate insecticides interact with a) esteratic site of acetylcholine enzyme (ACHE) b) anionic site of ACHE c) esteratic as well as anionic site of ACHE
A
Clonidine overdose mimics poisoning with a) morphine b) соcaine c) phencyclidine d) amphetamine
A
Fill- Shape Outline Shape Effects The metabolite of cocaine that may be detected for up to 72 hours post-ingestion is a. benzoylecgonine b. ethchlorvynol с. phenocolazine d. codiazepoxide
A
For which of the following routes of exposure is pre-systemic elimination possible? a) Oral (GIT) b) Inhalation c) Intramuscular d) Intravenous
A
For workplace drug programs, which of the following body fluids is used for drugs of abuse testing? a. urine b. saliva с. plasma d. capillary blood
A
If two organophosphate insecticides are absorbed into an organism, the result will be a) additive effect b) synergy effect c) potentiation d) subtraction effect
A
Knowledge of the toxicology of poisonous agents was published earliest in the a) Ebers Papyrus b) De Historia Plantarum c) De Materia Medica d) Lex Cornelia e) Treatise on Poisons and Their Antidotes
A
The LD50 is best described as which of the following: a) the dose at which 50% of all test animals die b) the dose at which 50% of the animals demonstrate a response to the chemical c) the dose at which all of the test animals die d) the dose at which at least one of the test animal dies
A
The LD50o is calculated from a) a quantal dose-response curve b) a hormesis dose-response curve c) a graded dose-response curve d) a log-log dose-response curve
A
The TD,/ED99 is called the a) margin of safety b) therapeutic index c) potency ratio d) efficacy ratio
A
The ability of a chemical to cause acute skin and eye irritation is usually evaluated in a a) rabbit b) rat c) mouse d) dog
A
The branch of science that deals with assessing the toxicity of substances of plant and animal origin and ti produced by pathogenic bacteria is a) toxicology b) toxinology c) toxicokinetics d) toxicodynamics
A
The differences between species in susceptibility to the toxicity of chemicals are usually the result of differences in metabolism. a) true b) false
A
The fetal period is characterized by all of the following except . a) beginning organ development b) tissue differentiation c) growth d) physiological maturation
A
The following immunoassays are homogeneous EXCEPT: а. Immunoradiometric Assay (IRMA) b. Enzyme Multiplied Immunoassay Technique (EMIT) с. Fluorescence Polarization Immunoassay (FPLA) d. Cloned Enzyme Donor Immunoassay (CEDIA)
A
The largest percent of antibodies belong to the class. a) IgG b) IgE c) IgM d) IgA e) IgD
A
The major site of absorption of poisonous substances for monogastric animals is a) large intestine b) small intestine c) colon d) rectum
A
The phenomenon of enzyme induction involves a) an increase in the synthesis of the enzyme b) an increase in the activity of the enzyme c) an increase in liver weight d) a change in the substrate specificity v of oft the enzyme e) an increase in bile flow
A
The primary toxic effect of salicylate is that it a. interferes with the function of the electron transport chain in the mitochondria b. interferes alcohol dehydrogenase с. interacts with beta oxidation d. interferes with glycolytic pathway
A
The rate of diffusion of a xenobiotic across the Gl tract is proportional to all of the following except a) hepatic blood flow b) surface area c) permeability d) residence time
A
The reference dose (RID) is generally determined by applying which of the following default procedures? a) An uncertainty factor of 100 is applied to the NOAEL in chronic animal studies b) A risk factor of 1000 is applied to the NOAEL in chronic animal studies c) A risk factor of 10,000 is applied to the NOAEL in subchronic animal studies d) An uncertainty factor between 10,000 and 1 million is applied to the NOAEL from chronic animal studies e) Multiplying the NOAEL from chronic animal studies by 100
A
The use of charcoal to prevent the absorption of diazepam is an example of a) dispositional antagonism b) chemical antagonism c) receptor antagonism d) functional antagonism
A
Which of the following are common end points? a) Death b) No observable effect level c) No observable adverse effect level d) lowest observakebadverse aleffect level e) all of the above
A
Which of the following does not contribute to the environmental presence of organochlorine insecticides? a) High water solubility b) Low volatility c) Chemical stability d) Low cost e) Slow rate of degradation
A
Which of the following hypersensitivity reactions is most often seen in transfusion reactions? a) Cytotoxic b) Cell-mediated c) Immune complex d) Anaphylactic e) None of the above
A
Which of the following toxicity can occur from a single exposure? a) Acute toxicity b) Subacute toxicity c) Subchronic toxicity d) Chronic toxicity
A
Which technique is helpful in removing ethanol from the body? a) Dialysis b) Activated charcoal c) Diuresis d) Haemoperfusion
A
1000 ppm is equivalent to 1%. a) True b) False
B
A subacute toxicity study in rats usually lasts a) 3 days b) 14 days c) 3 months d) 6 months
B
A toxic substance produced by a biological system is specially referred to as a a) toxicant b) toxin c) xenobiotic d) poison
B
A toxin with a half-life of 12 hours is administered every 12 hours. Which of the following is correct? a) The chemical is eliminated from the body before the next dose is administered. b) The concentration of the chemical in the body will slowly increase until the toxic concentration is attained. c) A toxic level will not be reached, regardless of how many doses are administered. d) Acute exposure to the chemical will produce immediate toxic effects. e) The elimination rate of the toxin is much shorter than the dosing interval.
B
Ablood lead concentration reported as 80 g/dL is the same as a) 0.08 ppm b) 0.8 ppm c) 8 ppm d) 80 ppm e) 800 ppm
B
After ______ ,93.8% of a dose of drug is eliminated. a) 3 half-lives b) 4 half-lives c) 5 half-lives d) 6 half-lives
B
All of the following are considered Phase I biotransformation reactions except a) hydrolysis b) conjugation c) reduction d) oxidation
B
All of the following are significantly stored in the bone matrix except a) lead b) diquat c) strontium d) fluoride
B
All of the following are true regarding idiosyncratic toxicant reactions except a) They are rare. b) They are predictable from the pharmacology of the drug. c) The reaction can be dose dependent. d) They involve genetic or acquired factors that increase susceptibility.
B
Anticholinesterase agents a) enhance the activity of ACHE b) increase ACh concentration in the synaptic cleft c) only target the neuromuscular junction d) antagonize ACh receptors e) cause decreased autonomic nervous system stimulation
B
Cocaethylene is а. a drug that has no biological activity b. a metabolite of cocaine and ethanol с. a substance that can be produced by acid hydrolysis in vitro d. all of the above
B
Drug testing designed to detect drug overdoses and formulate a treatment plan is referred to as a. forensic toxicology b. clinical toxicology с. medicolegal toxicology d. workplace toxicology
B
Ethanol is used as an antidote for the treatment of ethylene-glycol poisoning because it a) facilitates the excretion of ethylene glycol b) blocks the metabolism of ethylene glycol c) increases the detoxication of ethylene glycol d) chelates ethylene glycol e) none of the above
B
Extrapolation is best described as which of the following: a) using known information to reach a conclusion b) using known information to infer something about the unknown c) using speculative information to infer something about the known d) a 'best guess' approach
B
Federal regulations require that screening for the presence of illicit drugs be performed by which of the following methods? а. colorimetric spot tests b. immunoassay с. mass spectrometry d. thin-layer chromatography
B
Five identical experimental animals are treated with 1 mg of one of the following toxins. The animal treated with which toxin is most likely to die? a) Ethyl alcohol (LD50 = 10,000 mg/kg) b) Botulinum toxin (LD50 = 0.00001 mg/kg) c) Nicotine (LD50 = 1 mg/kg d) Ferrous sulfate (LD50 = 1500 mg/kg) e) Picrotoxin (LD50 = 5 mg/kg)
B
If ethanol and carbon-tetrachloride are chronically absorbed into an organism, the effect on the liver would be a) additive effect b) synergy c) potentiation d) subtraction effect
B
Increased production of methemoglobin is due to decreased activity of a) cytochrome P450 2B6 b) NADH cytochrome b5 reductase c) cytochrome oxidase d) cytochrome a3
B
Minimum dose of a toxicant producing the desired response is called a) ceiling dose b) threshold dose c) both a and b d) none
B
Minimum dose of a toxicant producing the desired response is called a) ceiling dose b) threshold dose c) both a and b d) none
B
Movement of xenobiotics molecules from the point of exposure site into circulation is called a) absorption b) distribution c) metabolism d) excretion
B
Prolonged muscle relaxation after succinylcholine is an example of a/an a) IGE-mediated allergic reaction b) idiosyncratic reaction c) immune complex reaction d) reaction related to a genetic increase in the activity of a liver enzyme
B
Regulatory toxicology aims at guarding the public from dangerous chemical exposures and depends primarily on which form of study: a) observational human studies b) controlled laboratory animal studies c) controlled human studies d) environmental studies
B
The first-pass effect for most of the drugs occurs in the a) tongue b) intestines c) rectum d) oral mucosa
B
The organs least involved in systemic toxicity are a) brain and peripheral nerves b) muscle and bone c) liver and kidney d) hematopoietic system and lungs
B
The phrase that best defines toxicodynamics' is the a) linkage between exposure and dose b) linkage between dose and response c) dynamic nature of toxic effects among various species d) dose range between desired biological effects and adverse health effects e) loss of dynamic hearing range due to a toxic exposure
B
The severity of a toxin depends, in large part, on the concentration of the toxin at its site of action. Which of the of following will decrease the amount of toxin reaching its site of action? a) Absorption across the skin b) Excretion via the kidneys c) Toxication d) Reabsorption across the intestinal mucosa e) Discontinuous endothelial cells of hepatic sinusoids
B
The therapeutic index is usually defined as a) TD50/LD50 b) ED50/LD50 c) LD50/ED50 d) ED50/TD50
B
The toxicity of a chemical is dependent on the amount of chemical reaching the systemic circulation. Which of the following does not greatly influence systemic availability? a) Absorption after oral dosing b) Intestinal motility c) Hepatic first-pass effect d) Intestinal first-pass effect e) Incorporation into micelles
B
The use of an antitoxin in the treatment of a snakebite is an example of a) dispositional antagonism b) chemical antagonism c) receptor antagonism d) functional antagonism
B
Toxicity associated with any chemical substance is referred to as a) poisoning b) intoxication c) overdose d) toxicology
B
Virtually safe doses are described at which confidence level? a) 90% b) 95% c) 99% d) 99.9% e) 99.99%
B
What is the mechanism for the harmful effects of CO (carbon monoxide)? a) Interfere with or block the active sites of some important enzymes b) Direct chemical combination with a cell constituent c) Secondary action as a result of its presence in the system d) Compete with the cofactors for a site on an important enzyme e) None of the above
B
Which of following is not a modifying factor that can influence the likelihood of disease? a) Age b) Dose c) Nutritional status d) Gender e) Genetic susceptibility
B
Which of the following assumptions is not correct regarding risk assessment for male reproductive effects in the absence of mechanistic data? a) An agent that produces an adverse reproductive effect in experimental animals is assumed to pose a potential reproductive hazard to humans. b) In general, a non-threshold is assumed for the dose-response curve for male reproductive toxicity. c) Effects of xenobiotics on male reproduction are assumed to be similar across species unless demonstrated otherwise. d) The most sensitive species should be used to estimate human risk. Reproductive processes are similar across mammalian species.
B
Which of the following is not a modifying actor that can influence the likelihood of disease? a) Age b) Dose c) Nutritional status d) Gender e) Genetic susceptibility
B
Which of the following is the correct definition of a complete carcinogen? a) Chemical capable only of initiating cells b) Chemical possessing the ability of inducing cancer from normal cells, usually of initiating, promoting, and progression agents c) Chemical capable of converting an initiated cell or a cell in the stage of promotion to a potentially malignant cell d) Chemical capable of causing the expansion of initiated cell clones e) Chemical that will cause cancer 100% of the time that it is administered
B
Which of the following is the most important in determining the extent of toxicity of a chemical? a) Chemical structure b) Dose c) Metabolism of the compound d) Excretion of the compound e) Metabolic detoxication of the compound
B
Which of the following lung diseases has the highest occupational death rate? a) Asbestosis b) Coal workers' pneumoconiosis c) Byssinosis d) Hypersensitivity pneumonitis e) Silicosis
B
Which of the following metals, when in toxic concentration, leads to decreased intelligence quotient (IQ) and growth in early childhood? a. mercury b. lead C. arsenic d. соpper
B
Which of the following most correctly describes the first-pass effect? a) The body is most sensitive to a toxin the first time that it passes through the circulation. b) Orally administered toxins are partially removed by the GI tract before they reach the systemic circulation. c) It only results from increased absorption of toxins by Gl cells. d) It is often referred to as 'postsystemic elimination'. e) A majority of the toxin is excreted after the first time the blood is filtered by the kidneys.
B
Which one of the following statements is regarding toxicology? a) Modern toxicology is concerned with the study of the adverse effects of chemicals on ancient forms of life. b) Modern toxicology studies embrace principles from such disciplines as biochemistry, botany, chemistry, physiology, and physics. c) Modern toxicology has its roots in the knowledge of plant and animal poisons, which predates recorded history and has been used to promote peace. d) Modem toxicology studies the mechanisms by which inorganic chemicals produce advantageous as well as deleterious effects. e) Modern toxicology is concemed with the study of chemicals in mammalian species.
B
With respect to dose-response relationships, which of the following is correct? a) Graded dose-response relationships are often referred to as 'all or nothing' responses. b) Quantal dose-response relationships allow for the analysis of a population's response to varying dosages. c) Quantal relationships characterize the response of an individual to varying dosages. d) A quantal dose-response describes the response of an individual organism to varying doses of a chemical. e) The dose-response always increases as the dosage is increased.
B
A dose of investigational toxicant that suppresses body weight gain slightly in a 90-day animal study is defined by some regulatory agencies to be a) LOAEL b) NOAEL c) MTD d) reference dosec
C
A toxin is selectively toxic to the lungs. Which of the following modes of toxin delivery would most likely cause the least damage to the lungs? a) Intravenous b) Intramuscular c) Intraperitoneal d) Subcutaneous e) Inhalation
C
All of the following are characteristic of DDT poisoning except a) paresthesia b) hypertrophy of hepatocytes c) increased potassium transport across the membrane d) slow closing of sodium ion channels e) dizziness
C
All of the following are components of the central compartment except a) liver b) lungs c) bone d) kidney
C
All of the following are reasons for selective toxicity except a) transport differences between cell b) biochemical differences between cell c) cytology of male neurons versus female neurons d) cytology of plant cells versus animal cells
C
Allergic contact dermatitis is a) a non-immune response caused by a direct action of an agent on the skin b) an immediate type-I hypersensitivity reaction c) a delayed type-IV hypersensitivity reaction d) characterized by the intensity of reaction being proportional to the elicitation dose e) not involved in photoallergic reactions
C
An immunoassay based on the direct observation of antigen-antibody reaction within a gel matrix is а. ΜΕΙΑ b. FPIA c. radial immunodiffușion d. ELISA
C
Asbestos exposure is unlikely to cause a) lung cancer b) Gl cancer c) emphysema d) pulmonary fibrosis e) mesothlioma
C
Clinical toxicity that is secondary to accidental exposure is a) toxicology b) intoxication c) poisoning d) overdose
C
Cytochrome P450 is an enzyme that a) is found in lysosomes b) is responsible for the conjugation of drugs c) is a central part of the drug-metabolizing system d) is one of the enzymes in the mitochondrial electron transport chain e) (c) and (d) are correct
C
Delta-9-tetrahydrocannabinol (THC) is the primary psychoactive component of a. benzodiazepines b. tricyclic antidepressants c.marijuana d. opiates
C
Examples of significant concentrations of a toxicant in a tissue that is not a target organ include all of the following except a) lead in bone b) DDT in adipose tissue c) paraquat in lung d) TCDD in adipose tissue
C
Following an aspirin overdose, the initial acid-base derangement is usually a) respiratory acidosis b) metabolic acidosis c) respiratory alkalosis d) metabolic alkalosis
C
If propyl alcohol and carbon tetrachloride are chronically absorbed into an organism, the effect on the liver would be a) additive effect b) synergy c) potentiation d) subtraction effect
C
Inhibition of acetylcholinesterase (ACHE) is the mechanism of action of which pesticide? a) Organochlorines b) Pyrethrins c) Organophosphates d) Rotenone e) Fipronil
C
MTD stands for a) minimum tolerated dose b) maximum total dose c) maximum tolerated dose d) maximum threshold dose
C
Measurement of serum acetaminophen concentrations is important for which of the following? a. assessment of the severity of methanol intoxication b. prognosis for patient with lung cancer c. assessment of liver damage d. presumption diagnosis of acute pancreatitis
C
Mercury can cross the following barriers in the body a) blood-brain barrier (BBB) b) placental barrier (PB) c) both d) no barrier
C
Methcathinone is a "designer" drug of which family? a. opiates b. phencyclidine с. amphetamines d. benzodiazepines
C
Paraquat is a highly toxic herbicide that causes damage through generation of reactive oxygen species. Which organ does paraquat accumulate in? a) Heart b) Brain c) Lung d) Spleen e) Small intestine
C
Place the following mechanisms of toxin delivery in order from most effective to least effective-1: intravenous; 2: subcutaneous; 3: oral; 4: inhalation; 5: dermal. a) 1, 5, 2, 4, 3. b) 4, 1, 2, 3, 5. c) 1, 4, 2, 3, 5, d) 4, 2, 1, 5, 3. e) 1, 4, 3, 2, 5.
C
Thalidomide was accidentally discovered as a a) cardiotoxic agent b) liver tonic c) sedative/tranquilizer d) cough mixture
C
The common units used to express total clearance of a toxicant are a) mg/mL b) mg/min c) mL/min d) mg/min/mL
C
The ingestion of poppy seeds may give a positive urine screen for a. cannabinoids b. cocaine metabolite с. opiates d. amphetamines
C
The measure of the margin of safety of a toxicant is obtained by a) LD50/ED 99 b) LD 1/ED 99 c) ED50/LD 50 d) LD50/ED 50
C
The most common target organ of toxicity is the a) heart b) lung c) CNS (brain and spinal cord) d) skin
C
The most effective treatment for Gl decontamination with acetaminophen is a) emesis b) gastric lavage c) activated charcoal d) dialysis
C
The most potent carcinogen derived from nicotine is a) naphthene b) styrene c) nicotine-derived nitrosamine ketone (NNK) d) meth tert-butyl ketone
C
The most rapid exposure to a chemical would occur through which of the following routes: a) oral b) subcutaneous c) inhalation d) intramuscular
C
The probability of an adverse outcome is defined as a) hazard b) exposure ratio c) risk d) susceptibility e) epidemiology
C
The systematic scientific characterization of adverse health effects resulting from human exposure to hazardous agents is the definition of a) risk b) hazard control c) risk assessment d) risk communication e) risk estimate
C
The use tamoxifen in certain breast cancers is an example of a) dispositional antagonism b) chemical antagonism c) receptor antagonism d) functional antagonism
C
Toxic exposure during the fetal period is likely to affect a) organogenesis b) implantation c) growth and maturation d) all of the above
C
What form of mercury was the cause of Minamata Bay disease? a) Mercuric salts b) Mercurous salts c) Organic mercury d) Elemental mercury
C
What is defined as 'a measurable biochemical, physiological, or other alteration within an organism that indicates health impairment or disease'? a) Biomarker of exposure b) Biomarker of susceptibility c) Biomarker of effect d) Biomarker of disease
C
When considering the dose-response relationship or an essential substance a) there are rarely negative effects of ingesting too much b) the curve is the same for all people c) adverse responses increase in severity with increasing or decreasing dosages outside of the homeostatic range d) the relationship is linear e) deficiency will never cause more harm than overingestion
C
Which of the following is an example of a definitive or reference method that is suitable for confirming positive drugs of abuse testing? а. Immunoassays b. HPLC с. GCMS d. Electrophoresis
C
Which of the following is defined as the highest non-statistically significant dose tested? a) ED50 b) ED100 c) NOAEL d) ADI e) COAEL
C
Which of the following is not absorbed in the colon? a) Water b) Sodium ion c) Glucose d) Hydrogen ion
C
Which of the following is not an objective of risk management? a) Setting target levels or risk b) Balancing risks and benefits c) Calculating lethal dosages d) Setting priorities or manufacturers e) Estimating residual risks
C
Which of the following statements is regarding risk analysis? a) It is a field of study that has been around for the last century. b) It was developed by the pharmaceutical companies in response to concerns over new medications. c) It is a relatively new field of study, spurred by new technologically based risks. d) It was largely a private-sector venture.
C
Which of the following types of epidemiologic study is always retrospective? a) Cohort b) Cross-sectional c) Case-control d) Longitudinal e) Exploratory
C
Which of the following was banned under the Delaney Clause of the Food Additive Amendment of 1958? a) Butylated hydroxytoluene b) Sulfamethazine c) Cyclamate d) Phytoestrogens
C
Which would increase the likelihood of a toxic dosage through dermal exposure? a) No preexisting skin disease. b) Toxic exposure to thick skin c) Increased percutaneous absorption rate d) Low surface area of exposure e) High epidermal intercellular junction integrity
C
A U-shaped graded toxicity dose-response curve is seen in humans with a) pesticides b) sedatives c) opiates d) vitamins
D
A newly formed hapten protein complex usually stimulates the formation of a significant amount of antibodies in a) 1-2 min b) 1-2 hours c) 1-2 days d) 1-2 weeks
D
A subchronic animal study required by the FDA will usually include a) two species (usually one rodent and one non-rodent) b) both genders c) at least three doses (low, intermediate, and high) d) all of the above
D
A target organ of toxicity is a) lung b) heart c) reproductive system d) kidney e) liver
D
All of the following are true of the toxic mechanism of paraquat except a) Lungs accumulate paraquat in an energy-dependent manner. b) Its energy into the lungs is assumed to be via the polyamine transport system. c) Similar molecules with smaller distances between nitrogen atoms do not enter lungs as readily. d) Cytotoxicity to alveolar cells is caused by interference with calcium channels.
D
All of the following could influence the gastrointestinal absorption of xenobiotics except a) pH b) intestinal microflora c) presence of food d) time of day
D
All of the following statements regarding apparent volume of distribution (V) are true except a) Va relates the total amount of chemical in the body to the concentration of chemical in the plasma. b) Va is the apparent space into which an amount of chemical is distributed in the body to result in a given plasma concentration. c) A chemical that usually remains in the plasma has a low Va. d) Va will be low for a chemical with high affinity for tissues. e) Va can be used to estimate the amount of chemical in the body if the plasma concentration is known.
D
Bioavailability of a drug refers to the a. availability for therapeutic administration b. availability of the protein-bound fraction of the drug с. drug transformation d. the fraction of the drug absorbed into the systemic circulation
D
Chemical clearance a) is independent of Va b) is unaffected by kidney failure c) is indirectly proportional to Va d) is performed by multiple organs. e) is not appreciable in the GI tract.
D
Chemicals known to produce dispositional tolerances are a) benzene and xylene b) trichloroethylene and methylene chloride c) paraquat and diquat d) carbon tetrachloride and cadmium
D
Cytochrome P450 activity can be affected by a) foods b) social habits c) thyroid disease d) all of the above
D
Drug X is available as a 2.5% solution for intravenous administration. The desired dosage of this drug is mg/kg. What volume of the drug should be injected if the animal weighs 50 kg? a) 0.2 ml b) 1.0 ml c) 2.0 mL d) 10 mL e) 20 mL
D
Metabolism of a foreign chemical will lead to a) accumulation of the chemical in the tissues b) increased excretion in urine c) decreased toxicity d) altered chemical structure e) increased toxicity
D
Phase 2 metabolism usually involves a) microsomal enzymes b) decreasing the polarity of a chemical c) increasing the toxicity of compounds d) the addition of an endogenous moiety e) hydrolysis
D
The acetylator phenotype is a) not found in dogs b) found exclusively in Asians c) responsible for the toxicity of amines d) an inherited trait affecting a particular metabolic reaction e) associated with the HLA type
D
The acute toxicity study in animals provides a) an appropriate lethal dose b) information on target organs c) information on dose selection for long-term studies d) all of the above
D
The effective dose is best described as which of the following: a) the dose at which 50% of all test animals die b) the dose at which some of the animals demonstrate a response to the chemical c) the dose at which all of the animals demonstrate a response to the chemical d) the dose at which 50% of all test animals demonstrate a response to the chemical
D
The liver and kidney are major target organs of toxicity because a) they both receive a high percentage of cardiac output b) they both have substantial xenobiotic metabolizing capacity c) they both have transport systems that can concentrate xenobiotics d) all of the above
D
The systemic availability of an orally administered toxicant is dependent on a) gastrointestinal absorption b) intestinal mucosa metabolism c) first-pass liver metabolism d) all of the above
D
The therapeutic index of a toxicant a) is the amount of a toxicant needed to cure an illness b) is lower in toxicants that are relatively safer c) describes the potency of a chemical in eliciting a desired response d) describes the ratio of the toxic dose to the therapeutic dose of a toxicant e) explains the change in response to a toxicant as the dose is increased
D
The treatment of strychnine-induced convulsions by diazepam is an example of a) chemical antagonism b) dispositional antagonism c) receptor antagonism d) functional antagonism
D
Toxicants most likely to be reabsorbed after being filtered at the glomerulus are a) organic anions b) organic cations c) natural polar molecules d) highly lipid soluble molecules
D
Urushiol is the toxin found in poison ivy. It must first react and combine with proteins in the skin in order for the immune system to recognize and mount a response against it. Urushiol is an example of which of the following? a) Antigen b) Auto antibody c) Superantigen d) Hapten e) Cytokine
D
What kind of hypersensitivity is associated with asthma? a) Cytotoxic b) Cell-mediated c) Immune complex d) Anaphylactic e) None of the above
D
Which form of mercury was the predominant cause of Minamata Bay disease? a) Metallic mercury b) Mercuric salts c) Mercurous salts d) Organic mercury compounds e) Mercury was not the causative agent
D
Which of the following are tools used in risk analysis? a) Toxicology b) Epidemiology c) Clinical trials d) All of the above
D
Which of the following forms of Hg is more toxic? a) Elemental b) Monovalent c) Divalent d) Organic in the body
D
Which of the following gases would most likely pass all the way through the respiratory tract and diffuse into the pulmonary blood supply? a) 03 (ozone) b) NO2 c) H2O d) CO e) SO2
D
Which of the following is considered to be the most predominant conjugation reaction during phase 11-type metabolism? a. hydroxylation b. sulfoxidation c. oxidation d. glucuronidation
D
Which of the following is least likely to increase the occupational inhalation of a chemical? a) Increased airborne concentration b) Increased respiratory rate c) Increased tidal volume d) Increased particle size e) Increased length of exposure
D
Which of the following is not an important site of toxicant storage in the body? a) Adipose tissue b) Bone c) Plasma proteins d) Muscle e) Liver
D
Which of the following is not important in hazard identification? a) Structure-activity analysis b) In-vitro tests c) Animal bioassays d) Susceptibility e) Epidemiology
D
Which of the following is true about facilitated transport? a. Concentration gradient across the membrane is not necessary b. A specific membrane carrier is not required с. Energy expenditure is necessary d. The process may be satarated by high substrate concentrations
D
Which of the following might increase the toxicity of a toxin administered orally? a) Increased activity of the MDR transporter (p-glycoprotein) b) Increased biotransformation of the toxin by gastrointestinal cells c) Increased excretion of the toxin by the liver into bile d) Increased dilution of the toxin dose e) Increased intestinal motility
D
Which of the following represents the dose below which no additional increase in response is observed? a) ED10 b) LD50 c) RfC d) Threshold e) Significance level
D
Which route of administration is associated with 100% bioavailability? a. sublingual b. intramuscular с. oral d. intravenous
D
several orders of magnitude higher. But when the two are given together, the toxic A dose of a Compound A is toxic to animals in vivo. Another Chemical B is not toxic when given at doses response is greater than that of the given dose of A alone. That is a) antagonism b) synergism c) additivity d) potentiation e) none of the above
D
A chemical with which of the following half-lives (T1/2) will remain in the body for the longest period of time when given equal dosage of each? a) TI/2 = 30 min b) TI/2 = 1 day c) TI/2 = 7 h d) TI/2 - 120 s e) TI/2 -1 month
E
The following properties can be attributed to methylmercury (organic Hg), a) mutagenic b) carcinogenic c) embryotoxic d) both b and c e) all of the above
E
The kidney is responsible for all of the following except a) synthesis of renin b) acid base balance c) reabsorption o electrolytes d) regulation of extracellular fluid e) release of angiotensin
E
The toxic effects of a chemical may be influenced by which of the following: 1) kidney function 2) body weight 3) rate of metabolism of the compound 4) time of day the chemical is administered Select the correct statement. a) 1, 2, and 3 b) 1 and 3 c) 2 and 4 d) 3 only 4 e) all four
E
Toxic chemicals are most likely to be biotransformed in which of the following organs? a) Central nervous system b) Heart c) Lung d) Pancreas e) Liver
E
When Chemicals A and B are administered simultaneously, their combined effects are far greater than the sum of their effects when given alone. The chemical interaction between Chemicals A and B can be described as which of the following? a) Potentiative b) Additive c) Antagonistic d) Unconditionally antagonistic e) Synergistic
E
Which information may be gained from an acute toxicity study? a) No effect level b) LD50 c) Therapeutie index d) Target organ e) All of the above
E
Which of the following insecticides blocks the electron transport chain at NADH-ubiquinone reductase? a) Nicotine b) Carbamate esters c) Nitromethylenes d) Pyrethroid esters e) Rotenoids
E
Which of the following is a statement about the biotransformation of ethanol? a) Alcohol dehydrogenase is only present in the liver. b) Ethanol is reduced to acetaldehyde by alcohol dehydrogenase. c) Ethanol and hydrogen peroxide combine to form acetaldehyde with the aid of a catalase. d) In spite of its catalytic versatility, cytochrome P450 does not aid in ethanol oxidation. e) Acetaldehyde is oxidized to acetic acid in the mitochondria by aldehyde dehydrogenase.
E
Bias is a problem primarily of clinical trials.
F
Case control studies start with the exposure and follow for the disease.
F
Clinical trials look at dose-response in animals.
F
Dose refers to the amount of a substance in the environment.
F
Environmental risk is a well-understood entity.
F
Subchronic studies are shorter than acute studies.
F
The maximum tolerated dose (MTD) is the level of chemical exposure where 10% of the animals die.
F
Case control studies are good for rare diseases.
T
Cross-sectional studies look at the exposure and disease at the same time.
T
The lethal dose refers to the dose at which 50% of test animals die.
T
