Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BOC review-Harr 5th ed > Chemistry 6.6 Enzymes and Cardiac Markers > Flashcards

Chemistry 6.6 Enzymes and Cardiac Markers Flashcards

1
Q

An international unit (IU) of enzyme activity is the quantity of enzyme that:
A. Converts 1 µmol of substrate to product per liter
B. Forms 1 mg of product per deciliter
C. Converts 1 µmol of substrate to product per minute
D. Forms 1 µmol of product per deciliter

A

C. Converts 1 µmol of substrate to product per minute

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Which of the following measurement modes does not allow for continuous monitoring of enzyme activity?
A. Initial absorbance is measured followed by a second reading after 5 minutes
B. Absorbance is measured at 10-second intervals for 100 seconds
C. Absorbance is monitored continuously for 1 minute using a chart recorder
D. Reflectance is measured from a xenon source lamp pulsing at 60 Hz

A

A. Initial absorbance is measured followed by a second reading after 5 minutes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Which of the following statements regarding enzymatic reactions is true?
A. The enzyme shifts the equilibrium of the reaction to the right
B. The enzyme alters the equilibrium constant of the reaction
C. The enzyme increases the rate of the reaction
D. The enzyme alters the energy difference between reactants and products

A

C. The enzyme increases the rate of the reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Which statement about enzymes is true?
A. An enzyme alters the Gibbs free energy of the reaction
B. Enzymes cause a reaction with a positive free energy to occur spontaneously
C. An enzyme’s natural substrate has the highest Km
D. A competitive inhibitor will alter the apparent Km of the reaction

A

D. A competitive inhibitor will alter the apparent Km of the reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Which substrate concentration is needed to achieve zero-order conditions?
A. Greater than 99 × Km
B. [S] = Km
C. Less than 10 × Km
D. [S] = 0

A

A. Greater than 99 × Km

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Which of the following statements is true?
A. Apoenzyme + prosthetic group = holoenzyme
B. A coenzyme is an inorganic molecule required for activity
C. Cofactors are as tightly bound to the enzyme as prosthetic groups
D. All enzymes have optimal activity at pH 7.00

A

A. Apoenzyme + prosthetic group = holoenzyme

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Which of the following statements about enzymatic reactions is true?
A. NADH has absorbance maxima at 340 and 366 nm
B. Enzyme concentration must be in excess to achieve zero-order kinetics
C. Rate is proportional to substrate concentration in a zero-order reaction
D. Accumulation of the product increases the reaction rate

A

A. NADH has absorbance maxima at 340 and 366 nm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

The increase in the level of serum enzymes used to detect cholestatic liver disease is caused mainly by:
A. Enzyme release from dead cells
B. Leakage from cells with altered membrane permeability
C. Decreased perfusion of the tissue
D. Increased production and secretion by cells

A

D. Increased production and secretion by cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Which of the following enzymes is considered most tissue specific?
A. CK
B. Amylase
C. ALP
D. ADH

A

D. ADH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Which of the following enzymes is activated by calcium ions?
A. CK
B. Amylase
C. ALP
D. LD

A

B. Amylase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Which of the following enzymes is a transferase?
A. ALP
B. CK
C. Amylase
D. LD

A

B. CK

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Which statement about methods for measuring LD is true?
A. The formation of pyruvate from lactate (forward reaction) generates NAD+
B. The pyruvate-to-lactate reaction proceeds at about twice the rate as the forward reaction
C. The lactate-to-pyruvate reaction is optimized at pH 7.4
D. The negative-rate reaction is preferred

A

B. The pyruvate-to-lactate reaction proceeds at about twice the rate as the forward reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Which condition produces the highest elevation of serum lactate dehydrogenase (LD)?
A. Pernicious anemia
B. Myocardial infarction
C. Acute hepatitis
D. Muscular dystrophy

A

A. Pernicious anemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

In which condition is the LD most likely to be within normal limits?
A. Hepatic carcinoma
B. Pulmonary infarction
C. Acute appendicitis
D. Crush injury

A

C. Acute appendicitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

The LD pleural fluid:serum ratio for a transudative fluid is usually:
A. 3:1 or higher
B. 2:1
C. 1:1
D. 1:2 or less

A

D. 1:2 or less

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

In which type of liver disease would you expect the greatest elevation of LD?
A. Toxic hepatitis
B. Alcoholic hepatitis
C. Cirrhosis
D. Acute viral hepatitis

A

A. Toxic hepatitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Which of the following conditions will interfere with the measurement of LD?
A. Slight hemolysis during sample collection
B. Storage at 4°C for 3 days
C. Storage at room temperature for 16 hours
D. Use of plasma collected in heparin

A

A. Slight hemolysis during sample collection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

In the Oliver-Rosalki method, the reverse reaction is used to measure CK activity. The enzyme(s) used in the coupling reactions is (are):
A. Hexokinase and G-6-PD
B. Pyruvate kinase and LD
C. Luciferase
D. Adenylate kinase

A

A. Hexokinase and G-6-PD

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

In the Oliver-Rosalki method for CK, AMP is added to the substrate to:
A. Inhibit adenylate kinase
B. Block the oxidation of glutathione
C. Increase the amount of ADP that is available
D. Block the action of diadenosine pentaphosphate

A

A. Inhibit adenylate kinase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Which substance is used in the CK assay to activate the enzyme?
A. Flavin adenine dinucleotide (FAD)
B. Imidazole
C. N-acetylcysteine
D. Pyridoxyl-5’-phosphate

A

C. N-acetylcysteine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

SITUATION: A specimen for CK performed on an automated analyzer using an optimized Oliver-Rosalki method gives an error flag indicating substrate depletion. The sample is diluted 1:2 and 1:4 by the serial dilution technique and reassayed. After correcting for the dilution, the results are as follows:

1:2 Dilution = 3,000 IU/L 1:4 Dilution = 3,600 IU/L

Dilutions are made a second time and assayed again but give identical results. What is the most likely explanation?

A. The serum became contaminated prior to making the 1:4 dilution
B. The wrong pipet was used to make one of the dilutions
C. An endogenous competitive inhibitor is present in the serum
D. An error has been made in calculating the enzyme activity of one of the two dilutions

A

C. An endogenous competitive inhibitor is present in the serum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

SITUATION: A physician calls to request a CK on a sample already sent to the laboratory for coagulation studies. The sample is 2-hour-old citrated blood and has been stored at 4°C. The plasma shows very slight hemolysis. What is the best course of action and the reason for it?
A. Perform the CK assay on the sample because no interferent is present
B. Reject the sample because it is slightly hemolyzed
C. Reject the sample because it has been stored too long
D. Reject the sample because the citrate will interfere

A

D. Reject the sample because the citrate will interfere

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Which of the following statements regarding total CK is true?
A. Levels are unaffected by strenuous exercise
B. Levels are unaffected by repeated intramuscular injections
C. Highest levels are seen in Duchenne muscular dystrophy
D. The enzyme is highly specific for heart injury

A

C. Highest levels are seen in Duchenne muscular dystrophy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

A patient’s CK-MB isoenzyme concentration is reported as 18 µg/L and the total CK as 560 IU/L. What is the CK relative index (CKI)?
A. 0.10%
B. 3.2%
C. 10.0%
D. 30.0%

A

B. 3.2%

CKI = (CK-BM in ug/L)/(Total CK in IU/L) * 100

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

In a nonmyocardial as opposed to a myocardial cause of an increased serum or plasma CK-MB, which would be expected?
A. An increase in CK-MB that is persistent
B. An increase in the percent CK-MB as well as concentration
C. The presence of increased troponin I (TnI)
D. A more modest increase in total CK than CK-MB

A

A. An increase in CK-MB that is persistent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Which statement best describes the clinical utility of plasma or serum myoglobin?
A. Levels greater than 100 µg/L are diagnostic of AMI
B. Levels below 100 µg/L on admission and 2 to 4 hours after admission help exclude a diagnosis of AMI
C. Myoglobin peaks after the cardiac troponins but is more sensitive
D. The persistence of myoglobin greater than 110 µg/L for 3 days after chest pain favors a diagnosis of AMI

A

B. Levels below 100 µg/L on admission and 2 to 4 hours after admission help exclude a diagnosis of AMI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Which statement best describes cardiac troponin I and T?
A. An enzyme embedded in the endocardium released after MI
B. Two polypeptides that regulate the sliding of contractile proteins in cardiac muscle
C. A peptide that is released in response to ventricular stretching
D. A prohormone released from the pericardium in response to injury

A

B. Two polypeptides that regulate the sliding of contractile proteins in cardiac muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What requirements must be met for a troponin assay to be considered a high-sensitivity test?
A. Must have a detection limit of 30 ng/L
B. Must be able to give a value for 100% of the healthy population who have a concentration above the limit of detection
C. Must have a coefficient of variation (CV) of less than 10% at the 99th percentile of the healthy population
D. Must have a clinical specificity of 99% or greater

A

C. Must have a coefficient of variation (CV) of less than 10% at the 99th percentile of the healthy population

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is the typical time course for high-sensitivity (guideline compliant) cardiac troponin I (cTnI) or cardiac troponin T (cTnT) following an AMI?
A. Abnormal within 1 hour; peak within 24 hours; return to normal in 7 to 10 days
B. Abnormal within 4 hours; peak within 18 hours; return to normal in 48 hours
C. Abnormal within 4 hours; peak within 24 hours; return to normal in 3 days
D. Abnormal within 6 hours; peak within 36 hours; return to normal in 5 days

A

A. Abnormal within 1 hour; peak within 24 hours; return to normal in 7 to 10 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What protocol is needed to rule out an MI with a high-sensitivity troponin assay?
A. A single sample at arrival
B. Serial samples for up to 3 hours after arrival
C. Serial samples for up to 6 hours after arrival
D. A minimum of four samples over 4 hours

A

B. Serial samples for up to 3 hours after arrival

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Which statement best describes the clinical significance of a single cTnI or cTnT result that is slightly above the limit of detection?
A. A positive test in the absence of laboratory error is diagnostic of MI
B. A positive test in the absence of laboratory error or in vitro false positive result indicates cardiac injury
C. Serial increases indicate necrosis caused by plaque rupture or thrombosis
D. Serial increases indicate S-T segment elevated myocardial infarction (STEMI)

A

B. A positive test in the absence of laboratory error or in vitro false positive result indicates cardiac injury

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Which of the following cardiac markers is most often increased in persons who exhibit unstable angina?
A. Troponin C
B. cTnT
C. CK-MB
D. Myoglobin

A

B. cTnT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

A patient has a plasma cTnT of 10 ng/L at admission. One hour later, the cTnT is 34 ng/L, and 3 hours later 120 ng/L. Electrocardiography (ECG) showed no change over this time. These results are consistent with which condition?
A. Skeletal muscle injury
B. Acute myocardial infarction
C. Unstable angina
D. No evidence of myocardial or skeletal muscle injury

A

B. Acute myocardial infarction

34
Q

SITUATION: A single heparinized plasma sample measured for troponin was found to have a concentration exceeding the laboratory’s upper reportable limit. However, the patient had a normal ECG result and was stable without showing any classic signs of MI and had no history of arteriosclerotic cardiovascular disease. What is the most likely cause?
A. Chronic renal failure
B. Recent angioplasty
C. Non-transmural MI
D. False positive troponin

A

D. False positive troponin

35
Q

SITUATION: An EDTA sample for cTnI assay gives a result of 40 ng/L (reference range 0–13 ng/L). The test is repeated 30 minutes later on a new specimen, and the result is 4 ng/L. A third sample collected 1 hour later gives a result of 5 ng/L. What is the most likely explanation?
A. A false-positive result occurred as a result of matrix interference
B. Heparin should have been used instead of EDTA, which causes false-positive results
C. The patient has suffered a heart attack
D. The patient has had an ischemic episode without cardiac injury

A

A. A false-positive result occurred as a result of matrix interference

36
Q

Which of the following laboratory tests is a marker for ischemic heart disease?
A. Oxidized LDL
B. F2 isoprostanes
C. Albumin cobalt binding
D. Free fatty acid binding protein

A

C. Albumin cobalt binding

37
Q

Which test becomes abnormal earliest in the progression of ACS?
A. Proprotein convertase subtilisin/kexin type 9 (PCSK9)
B. B-type natriuretic peptide (BNP)
C. Myoglobin
D. High-sensitivity CRP

A

D. High-sensitivity CRP

38
Q

Which statement best describes the clinical utility of BNP?
A. Abnormal levels may be caused by obstructive lung disease
B. A positive test result indicates prior myocardial damage caused by AMI that occurred within the last 3 months
C. A normal test result (less than100 pg/mL) helps rule out CHF in persons with symptoms associated with coronary insufficiency
D. A level greater than 100 pg/mL is not significant if evidence of CHF is absent

A

C. A normal test result (less than100 pg/mL) helps rule out CHF in persons with symptoms associated with coronary insufficiency

39
Q

Which statement best describes the clinical utility of plasma homocysteine?
A. Levels are directly related to the quantity of LDL cholesterol in plasma
B. High plasma levels are associated with atherosclerosis and increased risk of thrombosis
C. Persons who have an elevated plasma homocysteine will also have an increased plasma Lp(a)
D. Plasma levels are increased only when there is an inborn error of amino acid metabolism

A

B. High plasma levels are associated with atherosclerosis and increased risk of thrombosis

40
Q

Which of the following cardiac markers is derived from neutrophils and predicts an increased risk for MI?
A. Lipoprotein-associated phospholipase A2 (Lp-PLA2)
B. Glycogen phosphorylase-BB (GP-BB)
C. Cystatin C
D. Myeloperoxidase (MPO)

A

D. Myeloperoxidase (MPO)

41
Q

Which of the following statements about the aminotransferases (AST and ALT) is true?
A. Isoenzymes of AST and ALT are not found in humans
B. Both transfer an amino group to 2-oxogluterate (α-ketoglutarate)
C. Both require NADP+ as a coenzyme
D. Both utilize four carbon amino acids as substrates

A

B. Both transfer an amino group to 2-oxogluterate (α-ketoglutarate)

42
Q

Select the products formed from the forward reaction for measurement of AST.
A. Alanine and α–ketoglutarate
B. Oxaloacetate and glutamate
C. Aspartate and glutamine
D. Glutamate and NADH

A

B. Oxaloacetate and glutamate

43
Q

Select the products formed from the forward reaction for measurement of ALT.
A. Aspartate and alanine
B. Alanine and α–ketoglutarate
C. Pyruvate and glutamate
D. Glutamine and NAD+

A

C. Pyruvate and glutamate

44
Q

Which of the statements below regarding the methods of Henry for AST and ALT is correct?
A. Hemolysis will cause positive interference in both AST and ALT assays
B. Loss of activity occurs if samples are frozen at –20°C
C. The absorbance at the start of the reaction should not exceed 1.0 A
D. Reaction rates are unaffected by addition of P-5’-P to the substrate

A

A. Hemolysis will cause positive interference in both AST and ALT assays

45
Q

Select the coupling enzyme used in the AST reaction of Henry.
A. LD
B. Malate dehydrogenase (MD)
C. GLD
D. G-6-PD

A

B. Malate dehydrogenase (MD)

46
Q

What is the purpose of LD in the method of Henry for AST?
A. Forms NADH, enabling the reaction to be monitored at 340 nm
B. Rapidly exhausts endogenous pyruvate in the lag phase
C. Reduces oxaloacetate, preventing product inhibition
D. Generates lactate, which activates AST

A

B. Rapidly exhausts endogenous pyruvate in the lag phase

47
Q

Which of the following statements regarding the naming of transaminases is true?
A. Serum glutamic oxaloacetic transaminase (SGOT) is the older abbreviation for ALT
B. Serum glutamic pyruvic transaminase (SGPT) is the older abbreviation for AST
C. SGPT is the older abbreviation for ALT
D. SGOT is the newer abbreviation for AST

A

C. SGPT is the older abbreviation for ALT

SGOT refers to the products measured in the in vitro reaction, and is more correctly named AST for the four-carbon amino acid substrate aspartate.
SGPT is the older name referring to the products of the reaction for ALT. SGPT is more correctly named ALT for the three-carbon amino acid substrate alanine.

48
Q

Which statement accurately describes serum transaminase levels in AMI?
A. ALT is increased 5- to 10-fold after an AMI
B. AST peaks 24–48 hours after an AMI and returns to normal within 4–6 days
C. AST levels are usually 20–50 times the upper limit of normal after an AMI
D. Isoenzymes of AST are of greater diagnostic utility than the total enzyme level

A

B. AST peaks 24–48 hours after an AMI and returns to normal within 4–6 days

49
Q

Which condition gives rise to the highest serum level of transaminases?
A. Acute hepatitis
B. Alcoholic cirrhosis
C. Obstructive biliary disease
D. Diffuse intrahepatic cholestasis

A

A. Acute hepatitis

50
Q

In which liver disease is the DeRitis ratio (ALT:AST) usually greater than 1.0?
A. Acute hepatitis
B. Chronic hepatitis
C. Hepatic cirrhosis
D. Hepatic carcinoma

A

A. Acute hepatitis

51
Q

Which of the following liver diseases produces the highest levels of transaminases?
A. Hepatic cirrhosis
B. Obstructive jaundice
C. Hepatic cancer
D. Alcoholic hepatitis

A

C. Hepatic cancer

52
Q

Which of the following statements regarding transaminases is true?
A. ALT is often increased in muscular disease, pancreatitis, and lymphoma
B. ALT is increased in infectious mononucleosis, but AST is usually normal
C. ALT is far more specific for liver diseases than is AST
D. Substrate depletion seldom occurs in assays of serum from persons with hepatitis

A

C. ALT is far more specific for liver diseases than is AST

53
Q

Select the most sensitive marker for alcoholic liver disease.
A. GLD
B. ALT
C. AST
D. γ-Glutamyltransferase (GGT)

A

D. γ-Glutamyltransferase (GGT)

54
Q

Which enzyme is least useful in differentiating necrotic from obstructive jaundice?
A. GGT
B. ALT
C. 5’ Nucleotidase
D. LD

A

D. LD

55
Q

Which of the following statements about the phosphatases is true?
A. They hydrolyze adenosine triphosphate and related compounds
B. They are divided into two classes based upon pH needed for activity
C. They exhibit a high specificity for substrate
D. They are activated by Pi

A

B. They are divided into two classes based upon pH needed for activity

56
Q

Which of the following statements regarding ALP is true?
A. In normal adults, the primary tissue source is fast-twitch skeletal muscle
B. Geriatric patients have a lower serum ALP than other adults
C. Serum ALP levels are lower in children than in adults
D. Pregnant women have a higher level of serum ALP than other adults

A

D. Pregnant women have a higher level of serum ALP than other adults

57
Q

Which isoenzyme of ALP is most heat stable?
A. Bone
B. Liver
C. Intestinal
D. Placental

A

D. Placental

58
Q

Which isoenzyme of ALP migrates farthest toward the anode when electrophoresed at pH 8.6?
A. Placental
B. Bone
C. Liver
D. Intestinal

A

C. Liver

59
Q

Which statement regarding bone-specific ALP is true?
A. The bone isoenzyme can be measured immunochemically
B. Bone ALP is increased in bone resorption
C. Bone ALP is used for the diagnosis of osteoporosis
D. There are two distinct bone isoenzymes

A

A. The bone isoenzyme can be measured immunochemically

60
Q

Which of the following statements regarding ALP is true?
A. All isoenzymes of ALP are antigenically distinct and can be identified by specific antibodies
B. Highest serum levels are seen in intrahepatic obstruction
C. Elevated serum ALP seen with elevated GGT suggests a hepatic source
D. When jaundice is present, an elevated ALP suggests acute hepatitis

A

C. Elevated serum ALP seen with elevated GGT suggests a hepatic source

61
Q

In which condition would an elevated serum ALP be likely to occur?
A. Small cell lung carcinoma
B. Hemolytic anemia
C. Prostate cancer
D. Acute myocardial infarction

A

A. Small cell lung carcinoma

62
Q

Which condition is least likely to be associated with increased serum ALP?
A. Osteomalacia
B. Biliary obstruction
C. Hyperparathyroidism and hyperthyroidism
D. Osteoporosis

A

D. Osteoporosis

63
Q

Which substrate is used in the Bowers-McComb method for ALP?
A. p-Nitrophenyl phosphate
B. β-Glycerophosphate
C. Phenylphosphate
D. α-Naphthylphosphate

A

A. p-Nitrophenyl phosphate

64
Q

Which of the following buffers is used in the IFCC recommended method for ALP?
A. Glycine
B. Phosphate
C. 2-Amino-2-methyl-1-propanol
D. Citrate

A

C. 2-Amino-2-methyl-1-propanol

65
Q

A serum ALP level greater than twice the elevation of GGT suggests:
A. Misidentification of the specimen
B. Focal intrahepatic obstruction
C. Acute alcoholic hepatitis
D. Bone disease or malignancy

A

D. Bone disease or malignancy

66
Q

Which condition is associated with a decrease in ALP activity?
A. Pregnancy
B. VDDR
C. Hypophosphatasia
D. Bone fracture

A

C. Hypophosphatasia

67
Q

In which condition is the measurement of acid phosphatase clinically useful?
A. Measuring the prostatic isoenzyme to screen for prostate cancer
B. Measuring the enzyme in a vaginal swab extract
C. The diagnosis of hemolytic anemia
D. As a marker for bone regeneration

A

B. Measuring the enzyme in a vaginal swab extract

68
Q

Which definition best describes the catalytic activity of amylase?
A. Hydrolyzes second α-1-4 glycosidic linkages of starch, glycogen, and other polyglucans
B. Hydrolyzes all polyglucans completely to produce glucose
C. Oxidatively degrades polysaccharides containing glucose
D. Splits polysaccharides and disaccharides by addition of water

A

A. Hydrolyzes second α-1-4 glycosidic linkages of starch, glycogen, and other polyglucans

69
Q

Which of the following amylase substrates is recommended by the IFCC?
A. Starch
B. Maltodextrose
C. Maltotetrose
D. Blocked maltohepatoside

A

D. Blocked maltohepatoside

70
Q

How soon following acute abdominal pain due to pancreatitis is the serum amylase expected to peak?
A. 1–2 hours
B. 2–12 hours
C. 3–4 days
D. 5–6 days

A

B. 2–12 hours

71
Q

Which of the following statements regarding the diagnosis of pancreatitis is correct?
A. Amylase and lipase are as predictive in chronic as in acute pancreatitis
B. Diagnostic sensitivity is increased by assaying both amylase and lipase
C. Measuring the urinary amylase:creatinine ratio is useful only when patients have renal failure
D. Serum lipase peaks several hours before amylase after an episode of acute pancreatitis

A

B. Diagnostic sensitivity is increased by assaying both amylase and lipase

72
Q

Which of the following conditions is associated with a high level of S-type amylase?
A. Mumps
B. Intestinal obstruction
C. Alcoholic liver disease
D. Peptic ulcers

A

A. Mumps

73
Q

Which of the following statements regarding amylase methods is true?
A. Requires sulfhydryl compounds for full activity
B. Activity will vary depending on the method used
C. Amyloclastic methods measure the production of glucose
D. Over-range samples are diluted in deionized water

A

B. Activity will vary depending on the method used

74
Q

Which of the following statements regarding amylase methods is true?
A. Dilution of serum may result in lower than expected activity
B. Methods generating NADH are preferred because they have higher sensitivity
C. Synthetic substrates can be conjugated to p-nitrophenol (PNP) for a kinetic assay
D. The reference range is consistent from method to method

A

C. Synthetic substrates can be conjugated to p-nitrophenol (PNP) for a kinetic assay

75
Q

Which statement about the clinical utility of plasma or serum lipase is true?
A. Lipase is not increased in mumps, breast cancer, or ectopic pregnancy
B. Lipase is not increased as dramatically as amylase in acute pancreatitis
C. Increased plasma or serum lipase is specific for pancreatitis
D. Lipase levels are elevated in both acute and chronic pancreatitis

A

A. Lipase is not increased in mumps, breast cancer, or ectopic pregnancy

76
Q

In which condition would amylase but not lipase be elevated?
A. Pancreatic cancer
B. Peptic ulcer
C. Macroamylasemia
D. Renal failure

A

C. Macroamylasemia

77
Q

The most commonly employed method of assay for plasma or serum lipase is based on:
A. Hydrolysis of olive oil
B. Rate turbidimetry
C. Immunoassay
D. Peroxidase coupling

A

D. Peroxidase coupling

78
Q

Which of the following enzymes is usually depressed in liver disease?
A. Elastase-1
B. GLD
C. Pseudocholinesterase
D. Aldolase

A

C. Pseudocholinesterase

79
Q

Which enzyme is most likely to be elevated in the plasma of a person suffering from a muscle wasting disorder?
A. 5’-Nucleotidase
B. Pseudocholinesterase
C. Aldolase
D. Glutamate dehydrogenase

A

C. Aldolase

80
Q

Which enzyme is measured in whole blood?
A. Chymotrypsin
B. Glucose-6-phosphate dehydrogenase
C. Glycogen phosphorylase
D. Lipase

A

B. Glucose-6-phosphate dehydrogenase

BOC review-Harr 5th ed (41 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions