Chem TB Flashcards Unit 3
1) When arterial blood is exposed to air (as in air bubbles in
a collection syringe), what sets of changes occur?
2) Uptake of O2 by the blood in the lungs is controlled
primarily by:
3) Quantitative sweat chloride testing remains the standard
for diagnostic testing of cystic fibrosis (CF) because:
4) The anticoagulant that is considered best for anaerobic
collection of an arterial or venous whole blood specimen
for blood gas analysis is:
5) What is a cause of decreased fractional oxyhemoglobin
(FO2Hb)?
6) An increase in blood pH with a concomitant decrease in
PCO2 and a decreased body temperature and 2,3diphosphoglycerate will cause the oxygen dissociation
curve to:
7) In the Henderson-Hasselbalch equation, the term “pK'”
is the:
8) The PO2 at which the hemoglobin of the blood is half
saturated with O2 is referred to as:
9) In regard to the colligative properties of a solution, the
addition of solutes to pure solvent will _____ the vapor
pressure of that solution compared with pure solvent.
10) Historically, chloride was measured in blood by
spectrophotometry. Now the methods of choice for
chloride measurement include ion-selective electrodes
and:
11) A 24-hour-old infant is tested for quantitative sweat
chloride because her older brother was diagnosed with
cystic fibrosis. After iontophoresis of pilocarpine nitrate
and collection of sweat, the sample is analyzed by
coulometric titration. The value of the infant’s sweat
chloride was 23 mmol/L (reference interval: 29
mmol/L). The next day, the infant’s physician calls the
laboratory to report that the infant has difficulty breathing
and that the parents report the infant’s skin tasted salty.
The physician is considering a diagnosis of cystic
fibrosis. What type of error has likely occurred?
12) To stimulate sweating for a quantitative sweat chloride
test, _____ is iontophoresed into the skin.
13) The high extracellular concentration of which cation
contributes to the osmotic strength of extracellular fluid?
PO2 increased, PCO2
decreased, pH increased
the PO2 of alveolar air.
an amino acid deletion in the
CFTR gene resulting in the loss
of electrolyte transport across
cell membranes can only be
detected by sweat testing.
lyophilized heparin.
Conversion of part of
hemoglobin to dyshemoglobin
shift to the left.
negative log of the combined
dissociation constant for
carbonic acid.
P50
decrease
coulometric-amperometric
titration.
The infant was tested at too
young of an age for accurate
results to be obtained.
pilocarpine
Sodium
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Chem TB Flashcards Unit 3
14) What electrolytes is regulated in part by dietary intake?
a.
Chloride
b.
Potassium
c.
Sodium
d.
All of the above
15) The most common laboratory method of
sodium/potassium measurement in a high-throughput
automated chemistry analyzer is:
16) Osmolality is defined as the number of _____ of
solution.
17) The “electrolyte exclusion effect” is:
D
indirect ion-selective electrode
measurement.
moles of osmotic substances per
kilogram
an underestimation of
electrolyte concentration by
indirect ISE methods when
hyperproteinemia is present.
18) The correct formula for calculating plasma osmolality
is:
(mmol/L) + urea (mmol/L) + 9.
19) What statements concerning electrolytes and electrolyte Whole blood specimens should
measurement is incorrect?
be stored at 4° C before
separation.
20) Which blood gas parameter is most affected by the
PO2
choice of arterial versus venous blood?
21) A blood gas parameter is affected by the choice of
PO2 is generally lower in
arterial versus venous blood. What is the reason for the
venous blood after O2 is
difference in the value of this correctly identified
released in the capillaries and
parameter?
higher in arterial blood because
this blood has passed through
the lungs.
22) Although aqueous fluid control materials are the most
They are dissimilar to blood by
commonly used commercial controls for blood gas and
having lower viscosity and
pH measurements, what is their main disadvantage?
surface tension.
23) An instrument that hemolyzes whole blood by
co-oximeter.
sonication then determines total hemoglobin fractions by
spectrophotometry and calculation is called a(n):
24) The basic methodology used to measure pH, PCO2,
osmometry.
and PO2 is:
25) In an individual older than 6 months of age, what
Sweat chloride concentration
laboratory results is usually associated with cystic
greater than 60 mmol/L
fibrosis?
26) A blood sample from an individual with leukemia is
Because of leukocyte
submitted for blood gas analysis. The transport of the
glycolysis, pH decreases, PCO2
sample is delayed for approximately an hour before
increases, and PO2 decreases.
analysis. What affect, if any, will these two variables
have on the blood gas analysis results?
27) The most commonly measured colligative property of
the freezing point.
urine or plasma that is tested in the clinical laboratory to
determine osmolality is:
2
Chem TB Flashcards Unit 3
28) The specimen of choice for measurement of potassium
(K+) is plasma because:
29) The half-life of a protein hormone in plasma is:
30) What statements concerning steroid hormones is
correct?
31) The analytical method that provides better analytical
sensitivity in hormone detection than other methods such
as immunoassay or receptor-based assays is:
32) What protein hormones produces a decrease in blood
glucose by causing glucose to enter cells for energy
production?
33) Considering the classification of hormones by structure,
an example of a steroid hormone would be:
34) An example of a protein hormone synthesized in the
hypothalamus, with the principal action to control the
release of thyroid-stimulating hormone, is:
35) What hormones requires a transport protein to move it
through the circulation?
36) What statements concerning protein hormones is
correct?
37) A group of hormones produced by the gastrointestinal
tract that stimulates insulin secretion from the pancreas
and slows the rate of gastric emptying is referred to as:
38) What is an effect of increased parathyroid hormone
(PTH) secretion from the parathyroid gland in the
homeostatic control of serum calcium?
39) As part of homeostatic control by hormones, the
metabolism of electrolytes and water balance is
controlled in part by the renal system. What hormone
synthesized by the kidneys affects water and electrolyte
balance?
40) Calcium concentration in the blood is regulated by
what hormones?
41) Binding to a receptor at the outer cell membrane to
induce phosphorylation via adenylyl cyclase and cAMP
of certain intracellular enzymes is a property of which
class of hormone?
platelets release potassium
during the coagulation process
in a serum sample.
short, approximately 10 to 30
minutes.
Steroid hormones are
hydrophobic when free and
bind to intracellular receptors in
the nucleus.
tandem mass spectrometry.
Insulin
cortisol.
thyrotropin releasing hormone.
Estrogen
A protein hormone, once bound
to its receptor, activates
adenylyl cyclase, which leads to
eventual phosphorylation of
other cellular enzymes.
incretins.
Increased intestinal absorption
of calcium
Renin
Calcitriol and Parathyroid
hormone
Protein and
Amino acid-derived
3
Chem TB Flashcards Unit 3
42) The release of thyroid-stimulating hormone (from the
pituitary gland) stimulates the release of thyroid
hormones from the thyroid gland. When the level of
thyroid hormones increases in the circulation, they shut
off the release of TSH from the pituitary. This is an
example of which type of feedback?
43) An example of a polypeptide hormone that is part of
the complex integrative function of many hormones
involved in development of the human organism is:
44) In the gastrointestinal (GI) tract, dopamine functions as
a modulator of the enteric nervous system or as a
paracrine substance. What essential enzyme is required
for synthesis of dopamine in the dopaminergic system in
the GI tract?
45) In the diagnosis of pheochromocytoma, what hormone
is being assessed by measuring urine metanephrine?
46) A neoplasm considered to be a pediatric cancer that is
derived from the neural crest cells of the sympathetic
nervous system is referred to as a:
47) Measurement of urinary metanephrine and
vanillylmandelic acid (VMA) assesses the amount of
hormone secreted by the _____ and is done to detect the
presence of _____.
48) What substances is measured in urine to determine the
presence of a gastroenteropancreatic neuroendocrine
tumor in an individual with carcinoid syndrome?
49) In the assessment of equivocal results in
pheochromocytoma testing, the clonidine suppression test
is used to differentiate between:
50) Pheochromocytomas:
51) The amino acid precursor for the neurotransmitter
serotonin (5HT) is:
52) Metabolism of norepinephrine and epinephrine in
adrenal chromaffin cells requires the presence of what
enzymes for conversion into normetanephrine and
metanephrine?
53) In the sympathetic component of the autonomic
nervous system, norepinephrine acts to:
54) Regarding catecholamines, the amino acid from which
dopamine is synthesized?
55) An overnight fast is recommended for individuals being
tested for carcinoid syndrome because:
Negative feedback
growth hormone.
Tyrosine hydroxylase
Epinephrine
neuroblastoma.
adrenal medulla;
pheochromocytoma
5-Hydroxyindole acetic acid (5HIAA)
adrenal gland and sympathetic
nervous system increases in
catecholamine synthesis.
are benign in the majority of
cases.
tryptophan.
Catechol-O-methyltransferase
increase heart rate and blood
pressure.
Tyrosine
dietary interference, particularly
with foods that contain 5hydroxyindoles, will produce a
false increase in plasma 5HIAA measurement.
4
Chem TB Flashcards Unit 3
56) The urinary metabolite measured as an indicator of
dopamine synthesis is:
57) The rate-limiting step in the biosynthesis of
catecholamines is the:
homovanillic acid.
conversion of tyrosine to 3,4dihydroxyphenylalanine by
tyrosine hydroxylase.
The results will be falsely
elevated because of inhibition
of monoamine reuptake.
58) The use of tricycle antidepressants by an individual
may produce incorrect results in the measurement of
norepinephrine and normetanephrine during testing for
pheochromocytoma. How will results be affected and
why?
59) A man visits his physician complaining of hypertension pheochromocytoma.
(elevated heart rate and blood pressure), periodic bouts of
profuse sweating, and occasional severe headaches.
These symptoms are indicative of:
60) Currently, the most common method of analysis for
liquid chromatography (LC)
plasma catecholamines is:
with electrochemical (EC)
detection.
61) All of the following represent metabolic effects caused increased protein synthesis.
by the action of epinephrine secreted from the adrenal
gland except:
62) What statements concerning folic acid is correct?
Folic acid deficiency results in
megaloblastic anemia.
63) Deficiency of what vitamins will result in decreased
Pyridoxal phosphate (PLP)
heme synthesis?
64) What vitamins will aid in the absorption of iron by the
Vitamin C
intestine?
65) Absorption of vitamin B12 requires the presence of:
intrinsic factor.
66) Which vitamin is given to a newborn within minutes of Vitamin K
birth?
67) Scurvy is associated with deficiency of what vitamins? Vitamin C
68) What vitamins would be least affected by long periods
Vitamin C
of fat malabsorption?
69) The trace element that is important in the stabilization
fluoride.
of the surface of a regenerating tooth is:
70) A 65-year-old woman was admitted to the hospital in
Vitamin B12
mild congestive heart failure. She complained of a
burning sensation in her calves and feet and of weight
loss. Upon admission she appeared confused, depressed,
and pale. She had some edema around her ankles. Her lab
results were as follows: low hemoglobin and hematocrit,
increased RBC size, decreased RBC and WBC count, and
hypersegmented neutrophils. All basic chemistry values
were normal. Which vitamin should be tested for
deficiency?
71) A lack of _____ leads to the symptoms observed in
intrinsic factor
vitamin B12 deficiency.
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Chem TB Flashcards Unit 3
72) What is the common cause of vitamin B12 deficiency?
73) Trace elements are:
74) What specific specimen collection procedures should
be observed when assessing zinc deficiency?
75) What trace elements, when combined with an enzyme,
is essential for stabilization of extracellular matrixes such
as collagen and elastin?
76) The most commonly used method of analysis for
assessing vitamins A, K, and B6 is:
77) A 10-year-old girl visits her pediatrician. The physician
notes that the girl has immature secondary sex
characteristics and small stature. Her mother who has
accompanied her complains that the adolescent also
exhibits very slow healing of cuts and scrapes and has
had some hair loss. Your laboratory has ruled out any
inborn error of metabolism and possible cancer.
Deficiency of what trace element might be responsible
for the stated symptoms?
78) What trace elements would be most affected when a
hemolyzed sample is used for analysis?
79) Activity of what enzymes might be markedly affected
by a deficiency of zinc?
80) In trace element analysis, the coupling of an analytical
procedure with a technique that separates the chemical
complexes of individual elements present in any medium
is referred to as a(n):
81) Poor dark adaptation or night blindness is associated
with:
82) The ease with which iron can move from a reduced
form to an oxidized form in its metalloprotein transferrin
is important because:
83) The vitamin that is an antioxidant that acts as a
scavenger for lipid Peroxyl-free radicals and that has a
role in RBC protection from hemolysis is:
84) The trace element that is thought to mimic insulin
because of its activation of the cellular insulin response
is:
85) Bilirubin is considered to be the breakdown product of:
86) In blood, bilirubin is unconjugated but is bound to
_____ as it is transported to the liver.
Pernicious anemia
inorganic molecules found in
human and animal tissues in
milligram per kilogram amounts
or less.
Plasma is the specimen of
choice to avoid contamination
by RBCs, WBCs, and platelets.
Copper
high performance liquid
chromatography (HPLC).
Zinc
Manganese
Alkaline phosphatase
hyphenated technique.
deficiency of vitamin A.
transport of iron in transferrin
occurs only in the oxidized
state.
E
vanadium.
protoporphyrin IX.
Albumin
6
Chem TB Flashcards Unit 3
87) An 80-year-old patient visits his physician with an
elevated serum iron value and a decreased TIBC. The
most likely diagnosis in this case is:
88) The most popular assay used to determine iron
deficiency anemia is ferritin. What are the ferritin levels
in the correctly identified diagnosis in the preceding
question compared to normal?
89) Regarding serum iron analysis, the maximum
concentration of iron that transferrin can bind is reflected
in what laboratory measurement?
90) Iron is transported as ferric iron through the plasma by
means of:
91) In an individual using progesterone-based oral
contraceptives, serum iron _____ and TIBC _____.
92) Regarding the individual using progesterone-based oral
contraceptives, would the transferrin saturation be
increased, decreased, or not affected?
93) What statements concerning TIBC is not correct?
94) In the initial step of the diazo reaction for direct
bilirubin determination:
95) What soluble iron-protein complex is the form in which
iron is stored in tissues?
96) What is formed by the reduction of unconjugated
bilirubin in the intestines, is found in urine, and is further
oxidized to form urobilin?
97) The major substance formed from the breakdown of
hemoglobin when senescent red blood cells are
phagocytized by the reticuloendothelial system is:
98) The most common cause of iron deficiency anemia in
children is:
99) What is the percent transferrin saturation given the
transferrin 300 mg/dL, and ferritin 65 ng/mL?
100) The inherited disorders caused by an underproduction
of certain globin chains are referred to as the:
101) What sets of laboratory values correctly reflects an iron
deficiency state?
102) What is the mutational basis of an “elongation
hemoglobin?”
hemochromatosis.
Increased
Total iron binding capacity
(TIBC)
transferrin.
increases; increases
Increased
TIBC is decreased in an iron
deficiency anemia.
serum is added to an aqueous
solution of caffeine, sodium
acetate, and sodium benzoate.
Ferritin
Urobilinogen
bilirubin.
dietary deficiency.
43%
thalassemias.
Transferrin saturation low,
serum iron decreased, TIBC
low to normal
A single base pair mutation or
frameshift at either the 3' end of
exon 3 or the 5' end of exon 1
of the alpha2 or beta globin
chain
7
Chem TB Flashcards Unit 3
103) A patient presents with yellowish skin and eyes,
fatigue, and mild motor system dysfunction. Upon
assessment in the laboratory, the total bilirubin
concentration was shown to be 3.0 mg/dL (normal 0.21.0 mg/dL) with negative urinary bilirubin. Liver
function tests are normal. The most likely diagnosis in
this case would be:
104) High levels of unconjugated bilirubin that accumulate
in the brain are called:
105) The oxidation of the Fe+2 of hemoglobin to the Fe+3 of
methemoglobin by ferricyanide is the initial step in the:
106) In a certain hemoglobin structural variant, a deletion in
the coding gene results in a reduction of the production of
the beta globin chain. This will result in:
107) Increased total iron in serum is common in all of the
following except:
108) The two pairs of globin chains in normal HbA
hemoglobin are:
109) In hemoglobin F, which globin chains are different
from adult hemoglobin chains and what replaces them in
the adult?
110) A group of compounds containing four monopyrrole
rings connected by methane bridges is the:
111) A deficiency of the enzyme hydroxymethylbilane
synthase (HMBS) results in what acute porphyrias?
112) An individual visits his physician with porphyria-like
symptoms. The results of porphyrin analysis are as
follows: urine 5-aminolevulinic acid (ALA), positive;
urine coproporphyrin III, increased; RBC zinc
protoporphyrin (ZPP), increased. What laboratory test
should the physician order to determine the exact
diagnosis?
113) An individual is suspected of having some type of
porphyria although he has no skin lesions. The qualitative
screen demonstrates an elevated PBG and ALA in urine.
Upon quantitation, the PBG was noted as being more
increased than the ALA. Further quantitative tests
indicated increased uroporphyrin and fecal porphyrin.
The plasma fluorescence emission peak was at 624 to
628 nm. What is the likely diagnosis?
114. Moderate elevations of what occur secondary to lead
toxicity or iron-deficiency anemia?
115. The skin lesions observed in individuals with nonacute
porphyria are caused by:
Gilbert syndrome.
kernicterus.
cyanmethemoglobin method of
hemoglobin determination
decreased quantity of HbA.
chronic inflammation.
alpha and beta.
Gamma chains are replaced by
betas.
porphyrins.
Acute intermittent porphyria
(AIP)
Blood lead
Variegate porphyria (VP)
ALA
the excess presence of
porphyrins in the skin that
generate oxygen radicals.
8
Chem TB Flashcards Unit 3
116. An important amino acid in the synthesis of ALA is:
117. Porphyrin synthesis is regulated by modulation of what
enzymes?
118. What cofactors is required for heme synthesis?
119. The enzyme that is an iron-sulfur protein located in the
inner mitochondrial membrane that inserts ferrous iron into
protoporphyrin to form heme is:
120. The immediate precursor of the porphyrins is:
121. A physician calls the laboratory stating that one of her
patients is exhibiting what she suspects to be an acute
porphyric attack. The patient is having acute abdominal pains
and seems apathetic and distant. Initial laboratory analysis
should include:
122. A physician calls the laboratory stating that one of her
patients is exhibiting what she suspects to be an acute
porphyric attack. The patient is having acute abdominal pains
and seems apathetic and distant. If the urine test for PBG in
the preceding question is strongly positive and remains
elevated for 2 weeks or longer, what is the most likely
disease process?
123. Erythrocyte protoporphyria (EPP):
124. What is the name of the oxygen storage protein found
in muscle that uses heme as its prosthetic group?
125. An individual with jaundice reports to the emergency
department with symptoms of an acute porphyric attack,
including severe abdominal pain, pain in her thighs,
vomiting, and muscle weakness. A hepatitis screen is
negative and unconjugated bilirubin and urobilinogen are
increased. Your laboratory receives a dark orange-colored
urine sample for qualitative PBG analysis, results of which
are difficult to interpret. When you contact the physician
with this information, the physician informs you that this
patient is an alcohol abuser and asks you to run a quantitative
urine porphyrin analysis. Results of this analysis show an
increased uroporphyrin and coproporphyrin III. Why was the
PBG difficult to interpret?
126. When using DNA analysis to screen a new family to
identify a genetic mutation that has caused porphyria, what
must be examined?
127. Protoporphyrin that contains iron is known as:
128. The heme precursor that is elevated in PCT is:
129. When a drug concentration exceeds the available
metabolic capacity of the body, what does the drug’s
metabolism become dependent on?
glycine.
ALA-synthase (ALAS)
Pyridoxal phosphate
ferrochelatase.
porphobilinogen.
urinary PBG.
AIP
leads to progressive hepatic
failure.
Myoglobin
There was interference from
elevated urobilinogen in the
urine sample.
All exons with promoters and
flanking intron sequences
around the mutation must be
analyzed.
heme.
uroporphyrin.
The amount of metabolizing
enzyme
9
Chem TB Flashcards Unit 3
130. A hospital patient is receiving amikacin for her
Enterobacter infection, which seems to be resistant to all
other antibiotics. Her physician is somewhat unfamiliar with
the antibiotic and wants to know what laboratory analyses
can be performed to assess this antibiotic’s efficacy and risk
of toxicity. You suggest:
131. What could account for drug toxicity following a
prescribed dose?
132. The fraction of drug absorbed into a physiological
system that is based on the amount of drug given is referred
to as:
133. If a drug is acidic in nature, what proteins will it
associate with primarily for transport and distribution?
134. The therapeutic range of a drug is:
135. The period of time during which the concentration of a
therapeutic drug decays by 50% is referred to as the drug’s:
136. A hospitalized patient is being given gentamicin to treat
a gram-negative bacterial infection. The patient’s physician
contacts you regarding monitoring of this antibiotic because
this patient is beginning to exhibit signs of hearing loss and
renal failure. When you assess the patient’s 10-hour
postinfusion trough antibiotic concentration, it is increased.
You learn from the physician that he has been dosing the
patient to keep the antibiotic concentration high, “at a steady
state” he tells you. You state that:
137. The steady state of a drug is defined as the:
138. A woman is treated for a seizure disorder with
levetiracetam. She began experiencing dizziness and fatigue.
Blood cell values indicated decreased RBC count and low
hematocrit. Trough blood concentration of levetiracetam was
assessed to be 15 µg/mL, although her dosing should have
resulted in a trough therapeutic concentration of 3 µg/mL.
She claimed that she was not taking antacids or any other
medication. What is the likely cause of the elevated
levetiracetam?
139. What is a major active metabolite of procainamide that
must be monitored along with the parent drug?
140. What do both cyclosporine and tacrolimus inhibit?
both peak and trough amikacin
concentration assessment.
Decreased renal elimination
leading to increased free drug
concentration
bioavailability.
Albumin
the range of concentrations
within which the drug is
effective yet not toxic.
half-life.
with aminoglycoside
antibiotics, trough
concentrations must be allowed
to decrease because of the
postantibiotic effect.
point at which the body
concentration of the drug is in
equilibrium with the rate of
dose administered and the rate
of elimination.
The patient might have an issue
with her renal function, leading
to decreased elimination of the
drug.
N-acetylprocainamide
Calcineurin
10
Chem TB Flashcards Unit 3
141. What immunosuppressant prodrugs inhibits inosine
monophosphate dehydrogenase (IMPDH) to reduce the pool
of intracellular guanine nucleotides and arrest T-cell
proliferation?
142. The therapeutic drug used to treat all but absence
seizures by prolonging inactivation of the synaptic sodium
channel and reducing synaptic transmission is:
143. What is occurring in phase I metabolism of a
therapeutic drug?
144. What therapeutic drugs is considered to be a selective
serotonin reuptake inhibitor?
145. A class III antiarrhythmic drug that acts by blocking
potassium channels and that is used to manage atrial
fibrillation is:
146. What therapeutic drugs is used in the management of
acute lymphoblastic leukemia and inhibits DNA synthesis by
decreasing methylation of pyrimidine nucleotides and their
synthesis?
147. What is not a good rationale for monitoring the blood
concentration of a therapeutic drug?
148. Mycophenolate mofetil (MMF) is rapidly hydrolyzed
by widely distributed esterases in blood and tissue to produce
MPA. In regard to drug metabolism, this chemical reaction is
referred to as:
149. The method of monitoring therapeutic drug
concentrations that is replacing HPLC-based methods and is
now considered to be the best technology for analysis of
biological specimens with high specificity and fewer
interferences is:
150. For a therapeutic drug that has a short half-life, for
example levetiracetam, when is the appropriate time to
collect a blood sample for therapeutic drug assessment?
151. The name given to the group of enzymes that are
particularly involved in phase I metabolism of drugs and that
involve reduction/oxidation or hydrolysis is:
152. An individual who appears to be very inebriated is
brought to a hospital emergency department by the police.
Laboratory blood gas results indicate metabolic acidosis with
an increased serum osmol gap, the presence of serum
acetone, and many urine oxalate crystals. Which alcohol did
this individual ingest?
153.What is the major metabolite of acetaminophen that
is formed in the liver?
Mycophenolate mofetil
phenytoin.
Chemical modification such as
hydrolysis
Fluoxetine
amiodarone.
Methotrexate
To monitor drugs with a broad
therapeutic range
a phase I reaction.
liquid chromatography–mass
spectrometry/mass
spectrometry.
Immediately before a dose of
the drug is given
cytochromes P-450.
Isopropanol
Glucuronide
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Chem TB Flashcards Unit 3
154.) In a clinical laboratory without gas chromatography
instrumentation, the common method of choice used to
measure ethanol in serum or plasma is a(n):
155.In the liver methanol is metabolized by _____ to
form _____.
156.) Your toxicology testing facility tests urine samples.
New screening tests for methamphetamine and
amphetamine have been added to the drug profiles.
Occasionally a positive methamphetamine
immunoassay screening test is followed by a
negative amphetamine confirmatory test result. What
might cause this discrepancy?
157. In what specimen types is there a strong relationship
between it and plasma free drug concentration, but the
window of detection is short compared with that in a
urine specimen?
158. What enzymes is inhibited by organophosphate or
carbamate compounds, such as those found in pesticides?
159. A drug of abuse that stimulates the central nervous
system by blocking dopamine reuptake and rapidly
metabolizes to inactive benzoylecgonine and ecgonine
methyl ester is:
160. Respiratory alkalosis is a clinical feature of overdose
ingestion of salicylate because:
161. An individual is found unconscious with two empty pill
bottles nearby, one of aspirin and the other of
phenobarbital. The best antidote for this type of double
drug overdose would be:
162. The most common laboratory method for detection,
discrimination, and quantitation of alcohols in biological
specimens is:
163. In a chronic user of marijuana, the metabolite will
remain in urine for what period of time?
164. A type of drug test that is used to rule out the presence
of drugs or to suggest the presence of a particular drug
group and that has been replaced by rapid immunoassay
tests is the _____ test.
165. The correct formula for determining anion gap is:
enzymatic analysis using
alcohol dehydrogenase and
measurement of nicotinamide
adenine dinucleotide (NADH)
formation.
alcohol dehydrogenase;
formaldehyde
Other chemically related
compounds such as
pseudoephedrine have been
shown to produce positive
results in amphetamine
immunoassays.
Oral fluid
Acetylcholinesterase
cocaine
salicylates induce
hyperventilation.
forced alkaline diuresis.
flame ionization gas
chromatography (GC).
Up to 73 days
spot
[Na+] – [Cl- + HCO –]
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Chem TB Flashcards Unit 3
166. An 18-year-old man who had been found unresponsive
and face down in his bed after spending the day working
in his garage is brought to the hospital emergency
department. He had not responded to naloxone
administration given by the paramedics. His history
reveals that he was despondent over the recent death of
his father, with whom he enjoyed restoring antique
automobiles. Laboratory results indicate negative serum
acetone, elevated serum urea and creatinine, normal PO2,
decreased bicarbonate, increased PCO2, and increased
osmol gap (corrected for ethanol) and anion gap.
Urinalysis indicated many oxalate crystals. Based on
these laboratory results, what is the likely compound that
has affected this individual?
167. With the above patient, Based on these laboratory
results and the likely compound that has affected this
individual, what are the metabolizing enzyme and the
metabolite(s) formed from the toxic compound?
168. With the above patient, what is the best therapy?
169. With the above patient, a second anion gap is
calculated and the value has increased from the initial
value. Based on these laboratory results and the likely
compound that has affected this individual, what type of
acid-base imbalance is present?
170. What best explains the toxic effect of acetaminophen
overdose?
171. Following a school field trip to the country, four
teenage boys are admitted to the hospital emergency
department with visual system impairment and severe
abdominal pain. Laboratory evaluation reveals metabolic
acidosis, increased anion gap and osmol gap, negative
serum acetone, and no unusual urine sediments.
Intoxication by what is most likely responsible?
172. You receive a filled purple-top (EDTA-containing)
tube with a request for a cyanide assay that requires a
whole blood sample. You:
173. The enzyme responsible for the metabolism of delta-9tetrahydrocannabinol (THC) to its various metabolites is:
Ethylene glycol
Alcohol dehydrogenase;
glycolic and oxalic acids
Fomepizole
Metabolic acidosis
The hepatic necrosis is caused
by depletion of a substance in
the liver and
eventual accumulation of the
oxidized metabolite.
Methanol
know that the tube you received
is perfectly fine if well mixed
and proceed to run the sample
to check for evidence of
cyanide.
CYP2D6
13
Chem TB Flashcards Unit 3
174. To recognize a poisoning pattern, groups of drugs with
similar actions, symptoms, and clinical signs are
examined. These common signs and symptoms are
referred to as the:
175. An example of a nonbenzodiazepine sedative-hypnotic
that is used in drug-facilitated sexual assault that interacts
with a subtype of the GABAA receptor complex is:
176. Agents related to the anticholinergic toxidrome include
all of the following except:
177. A symphathomimetic drug that can be a drug of abuse
but has legitimate pharmacologic use as a treatment for
narcolepsy is:
178. Because of its rapid turnaround time, the laboratory
method of choice used to screen urine samples for their
opiate content is:
179. Cocaine is subject to recreational abuse because it:
180. Meconium is a difficult substance to analyze in a
clinical laboratory for drug assessment because:
181. A positive urine immunoassay screening test for a drug
of abuse must be confirmed by:
182. The best antidote for overdose with heroin is:
183. Laboratory analysis of what enzyme activities is
performed to assess acute neurotoxicity from
organophosphate or carbamate poisoning?
184. An individual is brought to the hospital emergency
department with nausea, vomiting, and an altered mental
status. An empty bottle of nonprescription enteric-coated
acetylsalicylic acid (aspirin) was found at her bedside by
her husband 30 minutes earlier. Although all signs and
symptoms point to salicylate overdose, laboratory
analysis indicated no acid-base disorder and low
salicylate concentration using a photometric procedure.
What is the explanation of this discrepancy?
185. The laboratory method of analysis that is accurate and
precise for very low concentrations of carbon monoxide
is:
186. The occurrence of cell membrane damage causing
normal cells to be replaced with fibroblasts occurs in the
heart because of a deficiency of what metals?
toxidrome.
zolpidem.
organophosphates.
amphetamine.
immunoassay.
blocks dopamine reuptake at
nerve synapses and prolongs the
action of dopamine in the CNS,
leading to feelings of euphoria.
it is a difficult material to work
with, and drug testing is far less
standardized than for a urine
specimen.
GC-MS.
naloxone.
Acetylcholinesterase
The enteric-coated pills delayed
aspirin absorption and blood
work was collected before the
salicylate could reach maximum
concentration.
gas chromatography.
Selenium
14
Chem TB Flashcards Unit 3
187. In blood collection for chromium or other trace metal
analysis, what aspect of specimen collection is critical?
188. What blood analyte does a toxic overdose of aluminum
affect?
189. An individual is admitted to the hospital with markedly
increased liver enzymes (transferases) and unusual
behavioral changes noted by her family. A protein
electrophoresis reveals decreased ceruloplasmin. What
toxic metals might be implicated in this individual’s
symptoms?
190. A byproduct of zinc and lead smelting, this metal is
also used in the production of rechargeable batteries.
Chronic exposure to this metal results in renal damage
and breathing its fumes causes pulmonary congestion
resembling chronic emphysema
191. What is a toxic metal that produces Mees’ lines upon
overdose exposure by denaturing keratin in fingernails?
192. Lead produces a serious toxic effect when ingested
because it:
193. What is the specimen of choice for determining arsenic
exposure in an individual and why?
194. Both mercury and arsenic produce their symptoms of
toxicity in a similar way. This includes:
195. A four-member family of fish-loving vegetarians has
become ill and visits their family practitioner. Their
symptoms include stumbling (ataxia), visual field loss,
and urinary difficulties. No Mees’ lines are observed.
Being environmentally conscious, they have their home
examined for toxic gases. All tests are negative. Based on
their history and symptoms, what toxic metal might be to
blame?
196. A four-member family of vegetarians has become ill
and visits their family practitioner. Their symptoms
include stumbling (ataxia), visual field loss, and urinary
difficulties. No Mees’ lines are observed. Based on their
symptoms and knowledge of the correct metal involved,
what is the best therapy?
197. All of the following factors must be demonstrated
before metal toxicity is considered a diagnosis except:
Using specially manufactured
collection tubes with unique
stoppers
Parathyroid hormone
Copper
Cadmium
Arsenic
does not allow for the
incorporation of heme into the
porphyrin molecule.
Urine is the specimen of choice
because arsenic is concentrated
in and excreted predominantly
by kidneys.
binding to the sulfhydryl groups
of protein causing loss of
protein activity.
Mercury
British anti-Lewisite (BAL)
More than two organ systems m
ust be affected.
15
Chem TB Flashcards Unit 3
198. When reporting the results of a urine metal analysis,
such as urine chromium, how are the results reported?
199. Certain metals are essential for life at low
concentrations and typically function as protein cofactors
required for enzymatic reactions. These particular
elements are located in which group(s) and row(s) of the
periodic table?
200.Match the disorder with the diagnostic analyte
measured in the laboratory.
A. Plasma/urine metanephrines
B. Urinary VMA
C. Melatonin
D. Urinary 5-HIAA
201.Match the correct vitamin to the disorder that the
vitamin deficiency would cause:
A. Thiamine
B. Retinol
C. Quinone
D. Cobalamin
202. Match the trace or ultratrace elements with the clinical
disorders associated with either deficiency or toxicity:
A. Chromium
B. Manganese
C. Copper
D. Selenium
203.Match each drug with its major therapeutic use:
A. Imipramine
B. Methotrexate
C. Quinidine
D. Lamotrigine
204. Match each drug with its major mode of action:
A. Amitriptyline
B. Procainamide
C. Phenobarbital
D. Sirolimus
205. Match the compound with the antidote for overdose:
A. N-acetylcysteine
B. Activated charcoal
C. Atropine
D. Hydroxycobalamin
206. Match the compound with its metabolite:
A. Glycolic acid
B. Morphine
C. Carboxylic acid
D. Acetaldehyde
In concentration units of the me
tal of interest per gram of creati
nine
Groups 6 through 12, row 4
A. Tumor of adrenal medullary
chromaffin cells
B. Neuroblastoma
C. Pineal gland tumor
D. Gastroenteropancreatic
endocrine tumor
A. Beriberi
B. Night blindness
C. Impaired blood coagulation
D. Megaloblastic anemia
A. Lung cancer
B. Parkinson disease-like
symptoms
C. Menkes disease
D. Loss of immunocompetence
A.
B.
C.
D.
Antidepressant
Antimetabolic
Antiarrhythmic
Antiepileptic
A.
B.
C.
D.
Tricyclic antidepressant
Antiarrhythmic
Antiepileptic
Immunosuppressant
A.
B.
C.
D.
Acetaminophen
Salicylic acid
Organophosphates
Cyanide
A.
B.
C.
D.
Ethylene glycol
Heroin
Barbiturate
Ethanol
16
Chem TB Flashcards Unit 3
207. Match the drug with its correct elimination half-life.
A. Diazepam
B. Heroin
C. Cocaine
D. . Carboxyhemoglobin
208. Match the substance with the suggested antidote for its
overdose.
A. Anticholinergic agents
B. Ethylene glycol
C. Methemoglobinemia
D. Benzodiazepine
209. Match the toxicant with its specific effect.
A. Pesticides (carbamates)
B. Carbon monoxide
C. Methamphetamine
D. Ethanol
210. Name the metal that might alter the results of the below
analytical issue.
a Reduced to a nontoxic form in biological specimens
b Blood specimens are not especially useful; urine is best
c Requires a lymphocyte proliferation test; serum or
urine quantification is not useful
d To examine erythrocytes, EDTA-anticoagulated blood
is specimen of choice
204. True or False: Whole blood specimens stored at 37° C
will demonstrate a falsely increased potassium value
because of red blood cell hemolysis.
205. True or False: Dopamine in the central nervous system
functions as a neurotransmitter important for regulating
an overall state of attention and vigilance.
206. True or False: In the analysis of plasma porphyrins,
porphyrins at neutral pH fluoresce between 610 to 640
nm.
207. True or False: The long elimination half-life of
marijuana that affects the duration of detection is due to
the reentry of THC from tissue fat stores into the
circulation
A.
B.
C.
D.
21 to 37 hours
2 to 6 minutes
30 mins to 1.5 hours
5 to 6 hours
A.
B.
C.
D.
232. Physostigmine
233. Ethanol
234. Methylene blue
235. Flumazenil
A. 236. Interferes with
enzyme action
B. 237. Blocks oxygen
binding to hemoglobin
C. 238. Central nervous
system stimulant
D. 239. Central nervous
system depressant
A. Lead
B. Beryllium
C. Arsenic
D. Chromium
False
False
True
True
17