Chemistry Flashcards
1
Q
Following overnight fasting, hypoglycemia in adults is defined as a glucose of:
a. ≤70 mg/dL
b. ≤60 mg/dL
c. ≤55 mg/dL
d. ≤45 mg/dL
A
d. ≤45 mg/dL (≤2.5 mmol/L)
2
Q
The following results are from a 21-year-old patient with a back injury who appears otherwise healthy:
whole blood glucose: 77 mg/dL (4.2 mmol/L)
serum glucose: 88 mg/dL (4.8 mmol/L)
CSF glucose: 56 mg/dL (3.1 mmol/L)
The best interpretation of these results is that:
a. the whole blood and serum values are expected but the CSF value is elevated
b. the whole blood glucose value should be higher than the serum value
c. all values are consistent with a normal healthy individual
d. the serum and whole blood values should be identical
A
c. all values are consistent with a normal healthy individual
3
Q
The preparation of a patient for standard glucose tolerance testing should include:
a. a high carbohydrate diet for 3 days
b. a low carbohydrate diet for 3 days
c. fasting for 48 hours prior to testing
d. bed rest for 3 days
A
a. a high carbohydrage diet for 3 days
4
Q
If a fasting glucose was 90 mg/dL, which of the following 2-hour-postprandial glucose results would most closely represent normal glucose metabolism?
a. 55 mg/dL
b. 100 mg/dL
c. 180 mg/dL
d. 260 mg/dL
A
b. 100 mg/dL (5.5 mmol/L)
5
Q
A healthy person with a blood glucose of 80 mg/dL (4.4 mmol/L) would have a simultaneously determined CSF glucose value of:
a. 25 mg/dL
b. 50 mg/dL
c. 100 mg/dL
d. 150 mg/dL
A
b. 50 mg/dL (2.3 mmol/L)
6
Q
A 25-year-old man became nauseated and vomited 90 minutes after receiving a standard 75 g carbohydrate dose for an oral glucose tolerance test. The best course of action is to:
a. give the patient a glass of orange juice and continue the test
b. start the test over immediately with a 50 g carbohydrate dose
c. draw blood for glucose and discontinue test
d. place the patient in a recumbent position, reassure him and continue the test
A
c. draw blood for glucose and discontinue test
7
Q
CSF for glucose assay should be:
a. refrigerated
b. analyzed immediately
c. heated to 56ºC
d. stored at room temperature after centrifugation
A
b. analyzed immediately
8
Q
Which of the following 2 hour postprandial glucose values demonstrates unequivocal hyperglycemia diagnostic for diabetes mellitus?
a. 160 mg/dL (8.8 mmol/L)
b. 170 mg/dL (9.4 mmol/L)
c. 180 mg/dL (9.9 mmol/L)
d. 200 mg/dL (11.0 mmol/L)
A
d. 200 mg/dL (11.0 mmol/L)
9
Q
Serum levels that define hypoglycemia in pre-term or low birth weight infants are:
a. the same as adults
b. lower than adults
c. the same as a normal full-term infant
d. higher than a normal full-term infant
A
b. lower than adults
10
Q
A 45-year-old woman has a fasting serum glucose concetration of 95 mg/dL (5.2 mmol/L) and a 2-hour-postprandial glucose concentration of 105 mg/dL (5.8 mmol/L). The statement which best describes this patient’s fasting serum glucose concentration is:
a. normal; reflecting glycogen breakdown by the liver
b. normal; reflecting glycogen breakdown by skeletal muscle
c. abnormal; indicating diabetes mellitus
d. abnormal; indicating hypoglycemia
A
a. normal; reflecting glycogen breakdown by the liver
11
Q
Pregnant women with symptoms of thirst, frequent urination or unexplained weight loss should have which of the following tests performed?
a. tolbutamide test
b. lactose tolerance test
c. epinephrine tolerance test
d. glucose tolerance test
A
d. glucose tolerance test
12
Q
In the fasting state, the arterial and capillary blood glucose concentration varies from the venous glucose concentration by approximately how many mg/dL (mmol/L)?
a. 1 mg/dL
b. 5 mg/dL
c. 10 mg/dL
d. 15 mg/dL
A
b. 5 mg/dL
13
Q
The conversion of glucose or other hexoses into lactate or pyruvate is called:
a. glycogenesis
b. glycogenolysis
c. gluconeogenesis
d. glycolysis
A
d. glycolysis
14
Q
Which one of the following values obtained during a GTT are diagnostic of diabetes mellitus?
a. 2-hour specimen = 150 mg/dL
b. fasting plasma glucose = 126 mg/dL
c. fasting plasma glucose = 110 mg/dL
d. 2-hour specimen = 180 mg/dL
A
b. fasting plasma glucose = 126 mg/dL (6.9 mmol/L)
15
Q
The glycated hemoglobin value represents the integrated values of glucose concentration during the preceding:
a. 1-3 weeks
b. 4-5 weeks
c. 6-8 weeks
d. 16-20 weeks
A
c. 6-8 weeks
16
Q
Monitoring long-term glucose control in patients with adult onset diabetes mellitus can best be accompanied by measuring:
a. weekly fasting 7 am serum glucose
b. GTT
c. 2-hour postprandial serum glucose
d. hemoglobin A1c
A
d. hemoglobin A1c
17
Q
A patient with Type I, insulin-dependent diabetes mellitus has the follwoing results:
fasting blood glucose increased
hemoglobin A1c increased
fructosamine normal
After reviewing these test results, the technologist concluded that the patient is in a:
a. “steady state” of metabolic control
b. state of flux, progressively worsening metabolic control
c. improving state of metabolic control as indicated by fructosamine
d. state of flux as indicated by the fasting glucose level
A
c. improving state of metabolic control as indicated by fructosamine
18
Q
Total glycosylated hemoglobin levels in a hemolysate reflect the:
a. average blood glucose levels of the past 2-3 months
b. average blood glucose levels for the past week
c. blood glucose level at the time the sample is drawn
d. hemoglobin A1c level at the time the sample is drawn
A
a. average blood glucose levels of the past 2-3 months
19
Q
Which of the following hemoglobins has glucose-6-phosphate on the amino-terminal valine of the beta chain?
a. S
b. C
c. A2
d. A1c
A
d. A1c
20
Q
A patient with hemolytic anemia will:
a. show a decrease in glycated Hgb value
b. show an increase in glycated Hgb value
c. show little or no change in glycated Hgb value
d. demonstrate an elevated Hgb A1
A
a. show a decrease in glycated Hgb value
21
Q
In using ion-exchange chromatophraphic methods, falsely increased levels of Hgb-A1c might be demonstrated by the presence of:
a. IDA
b. PA
c. thalassemias
d. Hgb S
A
d. Hgb S
22
Q
An increase in serum acetone is indicative of a defect in the metabolism of:
a. carbohydrates
b. fat
c. urea nitrogen
d. uric acid
A
a. carbohydrates
23
Q
An infant with diarrhea is being evaluated for a carbohydrate intolerance. His stool yields a positive copper reduction test and a pH of 5.0. It should be concluded that:
a. futher tests are indicated
b. results are inconsistent–repeat both tests
c. the diarrhea is not due to carbohydrate intolerance
d. the tests provided no useful information
A
a. futher tests are indicated
24
Q
Blood samples were collected at the beginning of an excercise class and after thirty minutes of aerobic activity. Which of the following would be most consistent with the post-exercise sample?
a. normal lactic acid, low pyruvate
b. low lactic acid, elevated pyruvate
c. elevated lactic acid, low pyruvate
d. elevated lactic acid, elevated pyruvate
A
d. elevated lactic acid, elevated pyruvate
25
What is the best method to diagnose lactase deficiency?
a. H2 breath test
b. plasma aldolase level
c. LDH level
d. D-xylose test
a. H2 breath test
26
The expected blood gas results for a patient in chronic renal failure would match the pattern of:
a. metabolic acidosis
b. respiratory acidosis
c. metabolic alkalosis
d. respiratory alkalosis
a. metabolic acidosis
27
Sever diarrhea causes:
a. metabolic acidosis
b. metabolic alkalosis
c. respiratory acidosis
d. respiratory alkalosis
a. metabolic acidosis
28
The following blood gas results were obtained:
pH 7.18; pO2: 86 mmHg; pCO2: 60 mmHg; O2 sat: 92%; HCO3-: 7921 mEq/L (21 mmol/L); TCO2: 23 mEq/L (23 mmol/L); base excess: -8.0 mEq/L (-8.0 mmol/L)
The patient's results are compatible with which of the following?
a. fever
b. uremia
c. emphysema
d. dehydration
c. emphysema
29
Factors that contribute to a PCO2 electrode requiring 60-120 seconds to reach equilibrium include the:
a. diffusion characteristics of the membrane
b. actual blood PO2
c. type of calibrating standard
d. potential of the polarizing mercury cell
a. diffusion characteristics of the membrane
30
An emphysema patient suffering from fluid accumulation in the alveolar spaces is likely to be in what metabolic state?
a. respiratory acidosis
b. respiratory alkalosis
c. metabolic acidosis
d. metabolic alkalosis
a. respiratory acidosis
31
At blood pH 7.40, what is the ratio of bicarbonate to carbonic acid?
a. 15:1
b. 20:1
c. 25:1
d. 30:1
b. 20:1
32
The reference range for the pH of arterial blood measured at 37ºC is:
a. 7.28-7.34
b. 7.33-7.37
c. 7.35-7.45
d. 7.45-7.50
c. 7.35-7.45
33
A 68-year-old man arrives in the emergency room with a glucose level of 722 mg/dL (39.7 mmol/L) and serum acetone of 4+ undiluted. An arterial blood gas from this patient is likely to be:
a. low pH
b. high pH
c. low PO2
d. high PO2
a. low pH
34
A patient is admitted to the emergency room in a state of metabolic alkalosis. Which of the following would be consistent with this diagnosis?
a. high TCO2, increased HCO3
b. low TCO2, increased HCO3
c. high TCO2, decreased H2CO3
d. low TCO2, decreased H2CO3
a. high TCO2, increased HCO3
35
A person suspected of having metabolic alkalosis would have which of the following laboratory findings?
a. CO2 content and PCO2 elevated, pH decreased
b. CO2 content decreased and pH elevated
c. CO2 content, PCO2 and pH decreased
d. CO2 content and pH elevated
d. CO2 content and pH elevated
36
Metabolic acidosis is described as a(n):
a. increase in CO2 content and PCO2 with a decreased pH
b. decrease in CO2 content with an increased pH
c. increase in CO2 with an increased pH
d. decrease in CO2 content and PCO2 with a decreased pH
d. decrease in CO2 content and PCO2 with a decreased pH
37
Respiratory acidosis is decribed as a(n):
a. increase in CO2 content and PCO2 with a decreased pH
b. decrease in CO2 content with an increased pH
c. increase CO2 content with an increased pH
d. decrease in CO2 content and PCO2 with a decreased pH
a. increase in CO2 content and PCO2 with a decreased pH
38
A common cause of respiratory alkalosis is:
a. vomiting
b. starvation
c. asthma
d. hyperventilation
d. hyperventilation
39
Acidosis and alkalosis are best defined as fluctuations in blood pH and CO2 content due to changes in:
a. Bohr effect
b. O2 content
c. bicarbonate buffer
d. carbonic anhydrase
c. bicarbonate buffer
40
A blood gas sample was sent to the lab on ice, and a bubble was present in the syringe. The blood had been exposed to room air for at least 30 minutes. The following change in blood gases will occur:
a. CO2 content increased/PCO2 decreased
b. CO2 content and PO2 increased/pH increased
c. CO2 content and PCO2 decreased/pH decreased
d. PO2 increased/HCO3 decreased
d. PO2 increased/HCO3 decreased
41
Sodium: 136 mEq/L
Potassium: 4.4 mEq/L
Chloride: 92 mEq/L
Bicarbonate: 40 mEq/L
pH: 7.32
PCO2: 79 mmHg
These results are most compatible with:
a. respiratory alkalosis
b. respiratory acidosis
c. metabolic alkalosis
d. metabolic acidosis
b. respiratory acidosis
42
Select the test which evaluates renal tubular function:
a. IVP
b. creatinine clearance
c. osmolarity
d. microscopic urinalysis
c. osmolarity
43
Sodium: 140 mEq/L
Potassium: 4.0 mEq/L
Glucose: 95 mg/dL
BUN: 10 mg/dL
Which osmolality is consistent with these results?
a. 188
b. 204
c. 270
d. 390
c. 270
44
The degree to which the kidney concentrates the glomerular filtrate can be determined by:
a. urine creatine
b. serum creatinine
c. creatinine clearance
d. urine to serum osmolality ratio
d. urine to serum osmolality ratio
45
Osmolal gap is the difference between:
a. the ideal and real osmolality values
b. calculated and measured osmolality values
c. plasma and water osmolality values
d. molality and molarity at 4ºC
b. calculated and measured osmolality values
46
The most important buffer pair in plasma is the:
a. phosphate/biphosphate pair
b. hemoglobin/imidazole pair
c. bicarbonate/carbonic acid pair
d. sulfate/bisulfate pair
c. bicarbonate/carbonic acid pair
47
Quantitation of Na+ and K+ by ion-selective electrode is the standard method because:
a. dilution is required for flame photometry
b. there is no lipoprotein interference
c. of advances in electrochemistry
d. of the absence of an internal standard
c. of advances in electrochemistry
48
What battery of tests is most useful in evaluating an anion gap of 22 mEq/L (22 mmol/L)?
a. Ca++, Mg++, PO-4 and pH
b. BUN, creatinine, salicylate and methanol
c. AST, ALT, LD and amylase
d. glucose, CK, myglobin and cryoglobulin
b. BUN, creatinine, salicylate and methanol
49
A patient with myeloproliferative disorder has the following values: Hgb: 13 g/dL; Hct: 38%; WBC: 30\*103/µL; platelets: 1000\*103/µL; serum Na+: 140 mEq/L; serum K+: 7 mEq/L
The serum K+ should be confirmed by:
a. repeat testing of the original serum
b. testing freshly drawn serum
c. testing heparinized plasma
d. atomic absorption spectrometry
c. testing heparinized plasma
50
Most of the carbon dioxide present in blood is in the form of:
a. dissolved CO2
b. carbonate
c. bicarbonate ion
d. carbonic acid
c. bicarbonate ion
51
Serum "anion gap" is increased in patients with:
a. renal tubular acidosis
b. diabetic alkalosis
c. metabolic acidosis due to diarrhea
d. lactic acidosis
d. lactic acidosis
52
The anion gap is useful for quality control of laboratory results for:
a. amino acids and proteins
b. blood gas analyses
c. sodium, potassium, chloride, and total CO2
d. calcium, phosphorus, and magnesium
c. sodium, potassium, chloride, and total CO2
53
The buffering capacity of blood is maintained by a reversible exchange process between bicarbonate and:
a. sodium
b. potassium
c. calcium
d. chloride
d. chloride
54
In respiratory acidosis, a compensatory mechanism is the increase in:
a. respiration rate
b. ammonia formation
c. blood PCO2
d. plasma bicarbonate concentration
d. plasma bicarbonate concentration
55
Which of the following electrolytes is the chief plasma cation whose main function is maintaining osmotic pressure:
a. chloride
b. calcium
c. potassium
d. sodium
d. sodium
56
A potassium level of 6.8 mEq/L (6.8 mmol/L) is obtained. Before reporting the results, the first step the technologist should take is to:
a. check the serum for hemolysis
b. rerun the test
c. check the age of the patient
d. do nothing, simply report out the result
a. check the serum for hemolysis
57
The solute that contributes the most to the total serum osmolality is:
a. glucose
b. sodium
c. chloride
d. urea
b. sodium
58
A sweat chloride result of 55 mEq/L and a sweat sodium of 52 mEq/L were obtained on a patient who has a history of respiratory problems. The best interpretation of these results is:
a. normal
b. normal sodium and an abnormal chloride, test should be repeated
c. abnormal results
d. borderline results, the test should be repeated
d. borderline results, the test should be repeated
59
Which of the following is true about direct ion selective electrodes for electrolytes?
a. whole blood specimens are acceptable
b. elevated lipids cause falsely decreased results
c. elevated proteins cause falsely decreased results
d. elevated platelets cause falsely increased results
a. whole blood specimens are acceptable
60
Sodium determination by indirect ion selective electrode is falsely decreased by:
a. elevated chloride levels
b. elevated lipid levels
c. decreased protein levels
d. decreased albumin levels
b. elevated lipid levels
61
A physician requested that electrolytes on a multiple myeloma patient specimen be run by direct ISE and not indirect ISE because:
a. excess protein binds Na in indirect ISE
b. Na is falsely increased by indirect ISE
c. Na is falsely decreased by indirect ISE
d. excess protein reacts with diluent in indirect ISE
c. Na is falsely decreased by indirect ISE
62
Which percentage of total serum calcium is nondiffusible protein bound?
a. 80-90%
b. 51-60%
c. 40-50%
d. 10-30%
c. 40-50%
63
Calcium concentration in the serum is regulated by:
a. insulin
b. parathyroid hormone
c. thyroxine
d. vitamin C
b. parathyroid hormone
64
The regulation of calcium and phosphorous metabolism is accomplished by which of the following glands?
a. thyroid
b. parathyroid
c. adrenal glands
d. pituitary
b. parathyroid
65
A patient has the following test results:
increased serum calcium levels
decreased serum phosphate levels
increased levels of parathyroid hormone
This patient most likely has:
a. hyperparathyroidism
b. hypoparathyroidism
c. nephrosis
d. steatorrhea
a. hyperparathyroidism
66
A hospitalized patient is experiencing increased neuromuscular irritability (tetany). Which of the following tests should be ordered immediately?
a. calcium
b. phosphate
c. BUN
d. glucose
a. calcium
67
Which of the following is most likely to be ordered in addtion to serum calcium to determine the cause of tetany?
a. magnesium
b. phosphate
c. sodium
d. vitamin D
a. magnesium
68
A reciprocal relationship exists between:
a. sodium and potassium
b. calcium and phosphate
c. chloride and CO2
d. calcium and magnesium
b. calcium and phosphate
69
Fasting serum phosphate concentration is controlled primarily by the:
a. pancreas
b. skeleton
c. parathyroid glands
d. small intestines
c. parathyroid glands
70
A low concentation of serum phosphorus is commonly found in:
a. patients who are receiving carbohydrate hyperalimentation
b. chronic renal disease
c. hypoparathyroidism
d. patients with pituitary tumors
a. patients who are receiving carbohydrate hyperalimentation
71
The following laboratory results were obtained:
increased calcium in the seruma nd urine
alkaline phosphate decreased in the serum and increased in the urine
normal or increased alkaline phosphatase in the serum
These results are most compatible with:
a. multiple myeloma
b. milk-alkali syndrome
c. sarcoidosis
d. primary hyperparathyroidism
d. primary hyperparathyroidism
72
The primary function of serum albumin in the peripheral blood is to:
a. maintain colloidal osmotic pressure
b. increase antibody production
c. increase fibrinogen formation
d. maintain blood viscosity
a. maintain colloidal osmotic pressure
73
The first step in analyzing a 24-hour urine specimen for quantitative urine protein is:
a. subculture the urine for bacteria
b. add the appropriate preservative
c. screen for albumin using a dipstick
d. measure the total volume
d. measure the total volume
74
The following data was obtained from a cellulose acetate protein electrophoresis scan:
albumin area: 75 units
gamma globulin area: 30 units
total area: 180 units
total protein: 6.5 g/dL
The gamma globulin content in g/dL is:
a. 1.1 g/dL
b. 2.7 g/dL
c. 3.8 g/dL
d. 4.9 g/dL
a. 1.1 g/dL
75
Total iron-binding capacity measures the serum iron transporting capacity of:
a. hemoglobin
b. ceruloplasmin
c. transferrin
d. ferritin
c. transferrin
76
The first step in the quantitation of serum iron is:
a. direct reaction with appropriate chromogen
b. iron saturation of transferrin
c. free iron precipitation
d. separation of iron from transferrin
d. separation of iron from transferrin
77
To assure an accurate ammonia level result, the specimen should be:
a. incubated at 37C prior to testing
b. spun and separated immediately, tested as routine
c. spun, separated, iced, and tested immediately
d. stored at room temperature until tested
c. spun, separated, iced, and tested immediately
78
Erroneous ammonia levels can be eliminated by all of the following except:
a. assuring water and reagents are ammonia-free
b. separating plasma from cells and performing test analysis as soon as possible
c. drawing the specimen in a prechilled tube and immersing the tube in ice
d. storing the specimen protected from light until the analysis is done
d. storing the specimen protected from light until the analysis is done
79
A serum sample demonstrates an elevated result when tested with the Jaffe reaction. This indicates:
a. prolonged hyperthermia
b. renal functional impairment
c. pregnancy
d. arrhythmia
b. renal functional impairment
80
Creatinine clearance is used to estimate the:
a. tubular secretion of creatinine
b. glomerular secretion of creatinine
c. renal glomerular and tubular mass
d. glomerular filtration rate
d. glomerular filtration rate
81
A blood creatinine value of 5.0 mg/dL (442.0 µmol/L) is most likely to be found with which of the following blood values?
a. osmolality: 292 mOsm/kg
b. uric acid: 8 mg/dL (475.8 µmol/L)
c. urea nitrogen: 80 mg/dL (28.56 µmol/L)
d. ammonia: 80 µg/dL (44 µmol/L)
c. urea nitrogen: 80 mg/dL (28.56 µmol/L)
82
90% of the copper present in the blood is bound to:
a. transferrin
b. ceruloplasmin
c. albumin
d. cryoglobulin
b. ceruloplasmin
83
Hemoglobin S can be separated from hemoglobin D by:
a. electrophoresis on a different medium and acidic pH
b. hemoglobin A2 quantitation
c. electrophoresis at higher voltage
d. Kleihauer-Betke acid elution
a. electrophoresis on a different medium and acidic pH
84
On electrophoresis at alkaline pH, which of the following is the slowest migrating hemoglobin?
a. Hgb A
b. Hgb S
c. Hgb C
d. Hgb F
c. Hgb C
85
Urobilinogen is formed in the:
a. kidney
b. spleen
c. liver
d. intestine
d. intestine
86
A serum sample was assayed for bilirubin at 10 am, and the result was 12 mg/dL. The same sample was retested at 3 pm. The result now is 8 mg/dL. The most likely explanation for this discrepancy is:
a. the reagent has deteriorated
b. the sample was exposed to light
c. a calculation error in the first assay
d. the sameple was not refrigerated
b. the sample was exposed to light
87
Kernicterus is an abnormal accumulation of bilirubin in:
a. heart tissue
b. brain tissue
c. liver tissue
d. kidney tissue
b. brain tissue
88
A stool specimen that appears black and tarry should be tested for the presence of:
a. occult blood
b. fecal fat
c. trypsin
d. excess mucus
a. occult blood
89
The most specific enzyme test for acute pancreatitis is:
a. acid phosphatase
b. trypsin
c. amylase
d. lipase
d. lipase
90
Which of the following enzymes are used in the diagnosis of acute pancreatitis?
a. amylase (AMS) and lipase (LPS)
b. aspartate aminotransferase (AST) and alanine aminotransferase (ALT)
c. 5'-nucleotidase (5'N) and gamma-glutamyl transferase (GGT)
d. aspartate aminotransferase (AST) and lactact dehydrogenase (LD)
a. amylase and lipase
91
Which of the following enzymes catalyzes the conversion of starch to glucose and maltose?
a. malate dehydrogenase
b. amylase
c. creatine kinase
d. isocitric dehydrogenase
b. amylase
92
A physician suspects his patient has pancreatitis. Which test(s) would be most indicative of this disease?
a. creatinine
b. LD isoenzymes
c. beta-hydroxybutyrate
d. amylase
d. amylase
93
Aspartate amino transferase (AST) is characteristially elevated in diseases of the:
a. liver
b. kidney
c. intestine
d. pancreas
a. liver
94
Amino transferase enzymes catalyze the:
a. exchange of amino groups and sulfhydryl groups between alpha-amino and sulfur-containing acids
b. exchange of amino and keto groups between alpha-amino and alpha-keto acids
c. hydrolysis of amino acids and keto acids
d. reversible transfer of hydrogen from amino acids to coenzyme
b. exchange of amino and keto groups between alpha-amino and alpha-keto acids
95
Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) are both elevated in which of the following diseases?
a. muscular dystrophy
b. viral hepatitis
c. pulmonary emboli
d. infectious mononucleosis
b. viral hepatitis
96
The greatest activities of serum AST and ALT are seen in which of the following?
a. acute viral hepatitis
b. primary biliary cirrhosis
c. metastatic hepatic cirrhosis
d. alcoholic cirrhosis
a. acute viral hepatitis
97
Which of the following clinical disoders is associated with the greatest elevation of lactate dehydrogenase isoenzyme 1?
a. pneumonia
b. glomerulonephritis
c. pancreatitis
d. pernicious anemia
d. pernicous anemia
98
The enzyme, which exists chiefly in skeletal muscle, heart, and brain, is grossly elevated in active muscular dystrophy, and rises early in myocardial infarction is:
a. lipase
b. transaminase
c. lactate dehydrogenase
d. creatine kinase
d. creatine kinase
99
The enzyme present in almost all tissues that may be separated by electrophoresis into 5 components is:
a. lipase
b. transaminase
c. creatine kinase
d. lactate dehydrogenase
d. lactate dehydrogenase
100
A common cause of falsely increased LD1 fraction of lactic dehydrogenase is:
a. specimen hemolysis
b. liver disease
c. congestive heart failure
d. drug toxicity
a. specimen hemolysis
101
The presence of whic of the following isoenzymes indicates acute myocardial damage?
a. CKMM
b. CKMB
c. CKBB
d. none
b. CKMB
102
In which of the following conditons would be a normal level of creatine kinase be found?
a. acute myocardial infarct
b. hepatitis
c. progressive muscular dystrophy
d. intramuscular injection
b. hepatitis
103
Of the following diseases, the one most often associated with elevations with elevations of lactate dehydrogenase isoenzymes 4 and 5 on electrophoresis is:
a. liver disease
b. hemolytic anemia
c. myocardial infarction
d. pulmonary edema
a. liver disease
104
When myocardial infarction ocurs, the first enzyme to become elevated is:
a. CK
b. LD
c. AST
d. ALT
a. CK
105
A scanning of a CK isoenzyme fractionation revealed 2 peaks: a slow cathodic peak (CKMM) and an intermediate peak (CKMB). A possible interpretation for this pattern is:
a. brain tumor
b. muscular dystrophy
c. myocardial infarction
d. viratl hepatitis
c. myocardial infarction
106
A 10-year-old child was admitted to pediatrics with an initial diagnosis of skeletal muscle disease. The best confirmatory tests would be:
a. creatine kinase and isocitrate dehydrogenase
b. gamma-glutamyl transferase and alkaline phosphatase
c. aldolase and creatine kinase
d. lactate dehydrogenase and malate dehydrogenase
c. aldolase and creatine kinase
107
In the immunoinhibition phase of the CKMB procedure:
a. M subunit is inactivated
b. B subunit is inactivated
c. MB is inactivated
d. BB is inactivated
a. M subunit is inactivated
108
The presence of increased CKMB activity on a CK electrophoresis patern is most likely found in a patient suffering from:
a. acute muscular stress following strenuous exercise
b. malignant liver disease
c. myocardial infarction
d. severe head injury
c. myocardial infarction
109
Increased serum lactic dehydrogenase activity due to elevation of fast fraction (1 and 2) on electrophoretic separation is caused by:
a. nephrotic syndrome
b. hemolytic anemia
c. pancreatitis
d. hepatic damage
b. hemolytic anemia
110
A serum smaple drawn in the emergency room from a 42-year-old man yielded the following laboratory results:
Increased CK
greatly increased AST
normal CKMB
Which of the following conditions might account for these values?
a. crush injury to the thigh
b. cerebrovascular accident
c. pulmonary infarction
d. early acute hepatitis
a. crush injury to the thigh
111
Given the following results:
marked increased alkaline phosphatase
slight increased aspartate amino transferase
slight increase alanine amino transferase
marked increase gamma-glutamyl transferase
This is most consistent with:
a. acute hepatitis
b. osteitis fibrosa
c. chronic hepatits
d. obstructive jaundice
d. obstructive jaundice
112
Given the following results:
slight increased in alkaline phosphatase, aspartate amino transferase, alanine amino transferase, and gamma-glutamyl transferase
This is most consisiten with:
a. acute hepatitis
b. chronic hepatitis
c. obstructive jaundice
d. liver hemangioma
b. chronic hepatitis
113
What specimen preparation is commonly used to perform the alkaline phosphatase isoenzyme determinations?
a. serum is divided into 2 aliquots, one is frozen and the other is refrigerated
b. serum is divided into 2 aliquots, one is heated at 56C and the other is unheated
c. no preparation is necessary since teh assay uses EDTA plasma
d. protein-free filtrate is prepared first
b. serum is divided into 2 aliquots, one is heated at 56C and the other is unheated
114
Regan isoenzyme has the same properties as alkaline phosphatase that originates in the:
a. skeleton
b. kidney
c. intestine
d. placenta
d. placenta
115
The most heat labile fraction of alkaline phosphatase is obtained from:
a. liver
b. bone
c. intestine
d. placenta
b. bone
116
The most sensitive enzymatic indicator for liver damage from ethanol intake is:
a. alanine aminotransferase (ALT)
b. aspartate aminotransferase (AST)
c. gamma-glutamyl transferase (GGT)
d. alkaline phosphatase
c. gamma-glutamyl transferase (GGT)
117
Isoenzyme assays are performed to improve:
a. precision
b. accuracy
c. sensitivit
d. specificity
d. specificity
118
The protein portion of an enzyme complex is called the:
a. apoenzyme
b. coenzyme
c. holoenzyme
d. proenzyme
a. apoenzyme
119
Which of the following chemical determinations may be of help in establishing the presence of seminal fluid?
a. lactate dehydrogenase (LD)
b. isocitrate dehydrogenase (ICD)
c. acid phosphatase
d. alkaline phosphatase
c. acid phosphatase
120
A 1-year-old girl with hyperlipoproteinemia and lipase deficiency has the following lipid profile:
cholesterol: 300 mg/dL
LDL: increased
HDL: decreased
triglycerides: 200 mg/dL
chylomicrons: present
A serum specimen from this patient that was refrigerated overnight would most likely be:
a. clear
b. cloudy
c. creamy layer over cloudy serum
d. creamy layer over clear serum
d. creamy layer over clear serum
121
Chylomicrons are present in which of the following dyslipidemias?
a. familial hypercholesterolemia
b. hypertriglyceridemia
c. deficiency in lipoprotein lipase activity
d. familial hypoalphalipoproteinemia
c. deficiency in lipoprotein lipase activity
122
Turbidity in serum suggests elevation of:
a. cholesterol
b. total protein
c. chylomicrons
d. albumin
c. chylomicrons
123
TSH is produced by the:
a. hypothalamus
b. pituitary gland
c. adrenal cortex
d. thyroid
b. pituitary gland
124
A patient has the following thyroid profile
decreased total T4
decreased free T4
positive thyroid peroxidase antibody
decreased TSH
This patient most probably has:
a. hyperthyroidism
b. hypothyroidism
c. a normal thyroid
d. Graves disease
b. hypothyroidism
125
A 45-year-old woman complains of fatigue, heat intolerance and hair loss. Total and free T4 are abnormally low. If the TSH showed marked elevation, this would be consistent with:
a. Graves disease
b. an adenoma of the thyroid
c. thyrotoxicosis
d. primary hypothyroidism
d. primary hypothyroidism
126
The majority of thyroxine (T4) is converted into the more biologically active hormone:
a. thyroglobulin
b. thyroid-stimulating hormone (TSH)
c. triiodothyronine (T3)
d. thyrotropin-releasing hormone
c. triiodothyronine (T3)
127
A 2-year-old child with a decreased serum T4 is descibed as being somewhat dwarfed, stock, overweight, and having coarse features. Of the following, the most informative additional laboratory test would be the serum:
a. thyroxine binding globulin (TBG)
b. thyroid-stimulating hormone (TSH)
c. triiodothyronine (T3)
d. cholesterol
b. thyroid-stimulating hormone (TSH)
128
The recommended initial thyroid function test for either a healthy, asymptomatic patient or a patient with symptoms which may be related to a thyroid disorder is:
a. free thyroxine (free T4)
b. thyroid-stimulating hormone (TSH)
c. total thyroxine (T4)
d. triiodothyronine (T3)
b. thyroid-stimulating hormone (TSH)
129
The screening test for congenital hypothyroidism is based upon:
a. TSH level in the newborn
b. thyroid-binding globulin level in the newborn
c. iodine level in the newborn
d. total thyroxine (T4) level in the newborn
d. total thyroxine (T4) level in the newborn
130
A 68-year-old female patient tells her physician of being "cold all the time" and recent weight gain, with no change in diet. The doctor orders a TSH level, and the laboratory reports a value of 8.7 µU/mL (reference range = 0.5-5.0 µU/mL). This patient most likely has:
a. primary hypothyroidism
b. Graves disease
c. a TSH-secreting tumor
d. primary hyperthyroidism
a. primary hypothyroidism
131
Which of the following is secreted by the placenta and used for the early detection of pregnancy?
a. follicle-stimulating hormone (FSH)
b. human chorionic gonadotropin (HCG)
c. luteinizing hormone (LH)
d. progesterone
b. human chorionic gonadotropin
132
In amniotic fluid, the procedure used to detect hemolytic disease of the newborn is:
a. measurement of absorbance at 450 nm
b. creatinine
c. lecithin/sphingomyelin ratio
d. estriol
a. measurement of absorbance at 450 nm
133
During a normal pregnancy, quantitative human chorionic gonadotropin (HCG) levels peak how many weeks after the last menstrual period?
a. 2-4
b. 8-10
c. 14-16
d. 18-20
b. 8-10 weeks
134
Which of the following steroids is an adrenal cortical hormone?
a. angiotensinogen
b. aldosterone
c. epinephrine
d. growth hormone
b. aldosterone
135
What common substrate is used in the biosynthesis of adrenal steroids, including androgens and estrogens?
a. cortisol
b. catecholamines
c. progesterone
d. cholesterol
d. cholesterol
136
Plasma for cortisol determinations were collected at 7am, after waking the patient, and at 10pm that eveining. The cortisol level of the morning sample was higher than the evening sample. This is consistent with:
a. a normal finding
b. Cushing syndrome
c. Addison disease
d. hypopituitarism
a. normal finding
137
Night blindness is associated with deficiency of which of the following vitamins?
a. A
b. C
c. niacin
d. thiamine
a. vitamin A
138
Beriberi is associated with deficiency of vitamin:
a. A
b. C
c. niacin
d. thiamine
d. thiamine
139
Scurvy is associated with deficiency of which of the following vitamins?
a. A
b. C
c. niacin
d. thiamine
b. vitamin C
140
Rickets is associated with deficiency of which of the following vitamins?
a. B1
b. C
c. niacin
d. D
d. vitamin D
141
Pellagra is associated with deficiency of which of the following vitamins?
a. A
b. B1
c. thiamine
d. niacin
d. niacin
142
The major action of angiotensin II is:
a. increased pituitary secretion of vasopressin
b. increased vasoconstriction
c. increased parathyroid hormone secretion by the parathyroid
d. decreased adrenal secretion of aldosterone
b. increased vasoconstriction
143
The urinary excretion product measured as an indicator of epinephrine production is:
a. dopamin
b. dihydroxyphenylalanine (DOPA)
c. homovanillic acid
d. vanillylmandelic acid (VMA)
d. vanillylmandelic acid (VMA)
144
Which of the following hormones regulates normal blood calcium levels?
a. thyroxine
b. estriol
c. parathyroid hormone
d. growth hormone
c. parathyroid hormone
145
A diagnosis of primary adrenal insufficiency requires demonstration of:
a. decreased urinary 17-keto- and 17-hydroxysteroids
b. decreased cortisol production
c. impaired response to ACTH stimulation
d. increased urinary cortisol excretion after metyrapone
c. impaired response of ACTH stimulation
146
The screen for adrenal cortex hyperfunction with the greatest sensitivity and specificity is:
a. 24-hour urine free cortisol
b. plasma cortisol
c. urinary 17-hydroxycorticosteroids
d. plasma corticosterone
a. 24-hour urine free cortisol
147
Which of the following sample collections would give an accurate assessment of potential excess cortisol production (hypercortisolism)?
a. collect a plasma sample as a baseline, and another one-hour after administration of metyrapone
b. collect a plasma sample at 8am only
c. collect a 24-hour urine free cortisol
d. collect a plasma sample at 8am and at 8am the next day
c. collect a 24-hour urine free cortisol
148
Aldosterone is released by the adrenal cortex upon stimulation by:
a. renin
b. angiotensinogen
c. angiotensin I
d. angiotensin II
d. angiotensin II
149
Clinical assays for tumor markers are most important for:
a. screening for the presence of cancer
b. monitoring the course of a known cancer
c. confirming the absence of disease
d. identifying patients at risk for cancer
b. monitoring the course of a known cancer
150
Detection of which of the following substances is most useful to monitor the course of a patient with testicular cancer?
a. alpha-fetoprotein
b. carcinoembryonic antigen
c. prolactin
d. testosterone
a. alpha-fetoprotein
151
Increased concentrations of alpha-fetoprotein (AFP) in adults are most characteristically associated with:
a. hepatocellular carcinoma
b. alcoholic cirrhosis
c. chronic active hepatitis
d. multiple myeloma
a. hepatocellular carcinoma
152
Carcinoembryonic antigen (CEA) is most likely to be produced in a malignancy involving the:
a. brain
b. testes
c. bone
d. colon
d. colon
153
Which of the following is useful in the detection and management of carcinoma of the prostate?
a. total prostate-specific antigen
b. prostatic acid phosphatase
c. human chorionic gonadotropin
d. alpha-fetoprotein
a. total prostate-specific antigen
154
Which of the following statements most correctly describes the utility of clinical laboratory assays for tumor markers?
a. tumor markers are useful to screen asymptomatic patients for tumors
b. tumor markers are highly specific
c. tumor markers indicate the likelihood of an individual developing a tumor
d. tumor markers are useful in tracking the efficacy of treatment
d. tumor markers are useful in tracking the efficacy of treatment
155
Cancer antigen 125 (CA 125) is a tumor marker associated with:
a. breast carcinoma
b. colon cancer
c. lung cancer
d. ovarian and endometrial carcinoma
d. ovarian and endometrial carcinoma
156
In addition to carcinoma of the prostate, elevated prostate-specific antigen (PSA) can occur due to:
a. aspirin therapy
b. exogenous steroid use
c. benign prostatic hyperplasia
d. statin therapy (cholesterol lowering drug)
c. benign prostatic hyperplasia
157
A drug has a half-life of 6 hours. If a dose is given every 6 hours, a steady-state drug level would usually be achieved in:
a. 3-5 hours
b. 10-12 hours
c. 24-42 hours
d. 48-50 hours
c. 24-42 hours
158
The drug procainamide is prescribed to treat cardiac arrhythmia. What biologically active liver metabolite of procainamide is often measured simultaneously?
a. phenobarbitol
b. quinidine
c. N-acetyl procainamide (NAPA)
d. lidocaine
C. N-acetyl procainamide (NAPA)
159
Cocaine is metabolized to:
a. carbamazepine
b. codeine
c. hydrocodone
d. benzoylecgonine
d. bezoylecgonine
160
The metabolite 11-nor-tetrahydrocannabinol-9-COOH can be detected by immunoassay 3-5 days after a single use of:
a. methamphetamine
b. cocaine
c. benzodiazepine
d. marijuana
d. marijuana
161
A 3-year-old child was evaluated for abdominal pain and anorexia by a physician. A CBC revealed a hemoglobin of 9.8 g/dL and basophilic stippling of the RBCs. The doctor should order further tests to check for poisoning from:
a. arsenic
b. iron
c. mercury
d. lead
d. lead
162
A carbonate salt used to control manic-depressive disorders is:
a. digoxin
b. acetaminophen
c. lithium
d. phenytoin
c. lithium
163
An antiepileptic (or anticonvulsant) used to control seizure disorders is:
a. digoxin
b. acetaminophen
c. lithium
d. phenytoin
d. phenytoin
164
A drug that relaxes the smooth muscles of the bronchial passages is:
a. acetaminophen
b. lithium
c. phenytoin
d. theophylline
d. theophylline
165
A cardiac glycoside that is used in the treatment of congenital heart failure and arrythmias by increasing the force and velocity of myocardial contraction is:
a. digoxin
b. acetaminophen
c. lithium
d. phenytoin
a. digoxin
166
A salicylate level is performed to detect toxicity caused by ingestion of excess:
a. acetaminophen
b. aspirin
c. ibuprofen
d. pseudoephedrine
b. aspirin
167
Lithium therapy is widely used in the treatment of:
a. hypertension
b. hyperactivity
c. aggression
d. manic-depressive (bipolar) disorder
d. manic-depressive (bipolar) disorder
168
Testing for the diagnosis of lead poisoning should include:
a. erythrocyte protoporphyrin (EPP)
b. urine delta-aminolevulinic acid
c. whole blood lead
d. zinc protoporphyrin (ZPP)
c. whole blood lead
169
Blood received in the laboratory for blood gas analysis must meet which of the following requirements?
a. on ice, thin fibrin strands only, no air bubbles
b. on ice, no clots, fewer than 4 air bubbles
c. on ice, no clots, no air bubbles
d. room temperature, no clots, no air bubbles
c. on ice, no clots, no air bubbles
170
In a specimen collected for plasma glucose analysis, sodium fluoride:
a. serves as a coenzyme of hexokinase
b. prevents reactivity of non-glucose reducing substances
c. precipitates proteins
d. inhibits glycolysis
d. inhibits glycolysis
171
As part of a hyperlipidemia screening program, the following results were obtained on a 25-year-old woman 6 hours after eating:
triglycerides: 260 mg/dL
cholesterol: 120 mg/dL
Which of the following is the best interpretation of these results?
a. both results are normal, and not affected by the recent meal
b. cholesterol is normal, but triglycerides are elevated, which may be attributed to the recent meal
c. both results are elevated, indicating a metabolic problem in addition to the nonfasting state
d. both results are below normal despite the recent meal, indicating a metabolic problem
b. cholesterol is normal, but triglycerides are elevated, which may be attributed to the recent meal
172
Blood was collected in a serum separator tube on a patient who has been fasting since midnight. The time of collection was 7am. The laboratory test which should be recollected is:
a. triglycerides
b. iron
c. LD
d. sodium
a. triglycerides
173
