Which of the following acute-phase reactant proteins decreases during inflammation? a. Transferrin b. α1-Antitrypsin c. Haptoglobin d. Fibrinogen

Which of the following refers to the threedimensional spatial configuration of a single polypeptide chain determined by disulfide linkages, hydrogen bonds. Electrostatic attractions, and van der Waals forces? a. Primary structure b. Secondary structure c. Tertiary structure d. Quaternary structure

Which of the following plasma proteins is primarily responsible for maintain in vivo colloidal osmotic pressure? a. Albumin b. Haptoglobin c. Fibrinogen d. α2-Macroglobulin

Which of the following best describes a peptide bond? a. An amino group and carboxyl group bonded to an alpha-carbon. b. A double carbon bond between the alpha-carbons of two amino acids. c. An amino group bonded to a carboxyl group of another amino acid. d. Two carboxyl groups bonded to the alpha-carbon of an amino group.

Which of the following results would correlate best with malnutrition and poor protein-caloric status? a. Decreased prealbumin b. Decreased γ-globulins c. Elevated ceruloplasmin d. Elevated α1-fetoprotein

Which of the following conditions would correlate best with a normal level of myoglobin? a. Multiple myeloma b. Acute myocardial infarction c. Acute renal failure d. Skeletal muscle injury

An immunofixation protein electrophoresis is performed on serum from a patient with the most common type of multiple myeloma. The resulting pattern would most likely reveal which of the following? a. An IgG monoclonal band b. Oligoclonal bands c. Significant β-γ bridging d. An IgM monoclonal band

Which of the following would indicate a plasma specimen was used for protein electrophoresis instead of serum? a. A small peak between the β- and γ-globulins b. A broad increase in the γ-globulin fraction c. A bridge between α1- and α2-globulins d. A significantly decreased albumin peak.

Which of the following conditions would correlate best with the presence of distinct oligoclonal bands in the γ-zone on CSF protein electrophoresis? a. Multiple sclerosis b. Multiple myeloma c. Bacterial meningitis d. Myoglobinemia

Which of the following conditions would correlate best with the serum protein electrophoresis results below? Albumin Decreased α1-globulins Increased α2-globulins Increased β -globulins Normal γ -globulins Normal a. Acute inflammation b. Chronic liver cirrhosis c. Nephrotic syndrome d. Monoclonal gammopathy

When a protein is dissolved in a buffer solution that is more alkaline than its pI and an electric current is passed through the solution, the protein will act as: a. An anion and migrate to the anode b. A cation and migrate to the cathode c. An anion and migrate to the cathode d. An uncharged particle and will not move

Which of the following conditions would correlate best with an elevated serum total protein with high levels of both albumin and globulins? a. Dehydration b. Myocardial infarction c. Glomerulonephritis d. Liver cirrhosis

Which of the following urine total protein results would correlate best with a patient with nephrotic syndrome? a. Normal b. Lower than normal c. Higher than normal d. Similar to levels in CSF total protein levels.

Isoelectric focusing is used to phenotype α1- antitrypsin deficiencies. When protein is electrophoresed, it migrates to which of the following? a. The site where the pH is the same as its pI. b. The site where the mass of the protein correlates with the pI. c. The site where the protein’s net charge exceeds the pI. d. The site where the protein’s net charge is less than the pI.

A CSF-serum albumin ratio of 9.8 was reported. How is this best interpreted? a. This ratio is in the normal range for the patient. b. The blood-brain barrier may be compromised. c. It is biologically impossible to achieve this value. d. This is diagnostic of fungal meningitis.

Which of the following CSF proteins would be measured when investigating active demyelination in multiple sclerosis? a. CSF-serum albumin ratio b. α1-Antitrypsin c. Myelin Basic protein d. Immunoglobulin G

NPN: (1) Allantoin (2) Ammonia (3) Creatinine (4) Urea a. 1, 2, and 3 b. 2, 3, and 4 c. 1, 3, and 4 d. 1, 2, and 4

Which compound constitutes nearly half of the NPN substances in the blood? a. Ammonia b. Creatinine c. Urea d. Uric acid

A technologist reports urea N of 9 mg/dL. What is the urea concentration for this sample? a. 3.2 mg/dL b. 4.2 mg/dL c. 18.0 mg/dL d. 19.3 mg/dL

Which blood collection tube additive can be used to collect a specimen for measurement of urea? a. Ammonium b. Lithium heparin c. Sodium citrate d. Sodium fluoride

n the clinical laboratory, Urea N is measured most often using: a. Conductivity b. Enzymatic reactions c. Isotope dilution mass spectrometry d. Multilayer film formats

Elevated blood urea concentration is termed: a. Azotemia b. BUN c. Uremia d. Uremic syndrome

Prerenal azotemia is caused by: a. Acute renal failure b. Chronic renal failure c. Congestive heart failure d. Urinary tract obstruction

A technologist obtains a urea N value of 61 mg/dL and a serum creatinine value of 2.5 mg/dL on a patient. These results indicate: a. Congestive heart failure b. Dehydration c. Glomerular nephritis d. Urinary tract obstruction

Uric acid is the final product of: a. Allantoin metabolism b. Amino acid metabolism c. Purine (adenine and guanine) metabolism d. The urea cycle

Sources of error in measurement of uric acid include: a. Assay interference b. Competition from alternate purine substrates c. Narrow spectrophotometer bandwidth d. Nonspecific enzyme activity

Which condition is not associated with elevated plasma uric acid concentration? a. Allopurinol overtreatment b. Gout c. Lesch-Nyhan syndrome d. Renal disease

Decreased uric acid (3)

Defective tubular reabsorption

Complete deficiency of hypoxanthine-guanine phosphoribosyltransferase results in which disease? a. Allantoinism b. Glycogen storage disease c. Lesch-Nyhan syndrome d. Megaloblastic anemia

First sign is often uric acid crystals resembling orange sand in diapers.

Glycogen storage disease

Uric acid nephrolithiasis refers to: a. Acidification of the urine to dissolve renal calculi b. Formation of renal calculi composed of uric acid c. Precipitation of urates in the urinary tract d. Saturation of the kidney with uric acid

A 45-year-old male presents to the emergency department complaining of intense joint pain. The previous night the patient experienced similar pain accompanied by inflammation and redness of his wrists and large toe. The physician on-call orders testing for serum uric acid concentration. Which laboratory results and diagnosis are consistent with the physician’s assessment? The reference interval for uric acid is 3.5 to 7.2 mg/dL? a. Uric acid 1.9 mg/dL; Fanconi syndrome b. Uric acid 1.0 mg/dL; Hereditary xanthinuria c. Uric acid 9.1 mg/dL; Alcoholism d. Uric acid 9.1 mg/dL; Gout

Which statement describes creatinine biosynthesis accurately? a. Creatine is phosphorylated in the liver to form phosphocreatinine b. Creatine phosphate undergoes spontaneous cyclization to form creatinine c. Creatinine is formed from creatine and creatine phosphate in the liver d. Creatinine is synthesized from arginine, glycine, and methionine in the liver

Substances known to increase results when measuring creatinine by the Jaffe reaction includes: (1) Ascorbic acid (2) Bilirubin (3) Glucose (4) α-ketoacids a. 1, 2, and 3 b. 2, 3, and 4 c. 1, 3, and 4 d. 1, 2, and 4

n the Jaffe reaction, a red-orange chromogen is formed when creatinine reacts with: a. Aluminum magnesium silicate b. Creatininase c. Phosphocreatine d. Picric acid

Creatinine excretion typically: a. Decreases from childhood to middle age b. Does not vary with age and sex c. Is higher for females than for males d. Is highest for adult men aged 18 to 50 years

Use of serum creatinine to calculate GFR: a. Is discouraged because the calculations are complex. b. Is encouraged as a means to identify kidney disease and improve patient care c. Requires hospitalization of the patient for specimen collection d. Requires simultaneous measurement of creatinine in a 24-hour urine collection

Which factor must be considered for calculation of creatinine clearance using the MDRD equation? a. Certification of body mass index b. Documentation of specimen collection time c. Identification of ethnicity d. Verification that the patient was fasting

Which situation would be expected to falsely increase measured blood ammonia concentration? a. The patient smoked two cigarettes 15 minutes prior to phlebotomy. b. The patient was fasting for 8 hours before blood collection. c. The patient ate a steak dinner the night before the specimen was collected. d. The specimen was placed on ice immediately after collection.

Although arterial blood is the recommended specimen for determination of this analyte, it is seldom used. a. Ammonia b. Creatine c. Urea d. uric acid

Toxic effect of elevated blood ammonia concentration include: a. Decreased renal function b. Hemorrhage and dehydration c. Mental status and coma d. Pain and inflammation of peripheral joints

Ammonia concentrations are measured to evaluate: a. Acid-base status b. Glomerular filtration c. Hepatic encephalopathy d. Renal failure

Ammonia concentration correlates with disease severity and prognosis for a. Astrocytosis b. Inherited deficiencies of urea cycle enzymes c. Neurological deterioration d. Reye’s syndrome

When a reaction is performed in zero-order kinetics: a. The rate of the reaction is independent of the substrate concentration b. The substrate concentration is very low c. The rate of reaction is directly proportional to the substrate concentration d. The enzyme level is always high

Activation energy is: a. Decreased by enzymes b. The energy needed for an enzyme reaction to stop c. Increased by enzymes d. Very high in catalyzed reactions

Enzyme reaction rates are increased by increasing temperatures until they reach the point of denaturation at: a. 40 to 60 *C b. 25 to 35 C c. 100 C d. 37 *C

An example of using enzymes as reagents in the clinical laboratory is: a. The hexokinase glucose method b. The diacetyl monoxime blood urea nitrogen c. The alkaline picrate method d. Biuret total protein method

Activity of enzymes in serum may be determined rather than concentration because: a. The amount of enzyme is too low to measure b. The temperature is too high c. There is not enough substrate d. The amount of enzyme is too high to measure

The isoenzyme LD-4 and LD-5 are elevated in: a. Liver disease b. Pulmonary embolism c. Renal disease d. Myocardial infarction

Which CK isoenzyme is elevated in muscle diseases? a. CK-MM b. CK-BB c. CK-MB d. CK-NN

Elevation of serum amylase and lipase is commonly seen in: a. Acute pancreatitis b. Acute appendicitis c. Gallbladder disease d. Acid reflux disease

The saccharogenic method for amylase determinations measures: a. The amount of product produced b. The amount of substrate consumed c. The amount of iodine present d. The amount of starch present

Elevation of tissue enzymes in serum may be used to detect: a. Tissue necrosis or damage b. Inflammation c. Infectious disease d. Diabetes mellitus

Which of the following enzyme patterns is MOST diagnostic of Duchenne-type muscular dystrophy? a. Total CK level that is 5 to 10 times the ULN b. Total CK level that is 25 times the ULN c. Total CK level that is 50 to 100 times the ULN d. Total CK level that is 1,000 times the ULN

Which of the following preanalytical errors most commonly causes false increase in serum enzyme measurement? a. The patient was not fasting prior to blood draw b. The blood sample was not maintained on ice upon collection and during transport to the laboratory c. The serum was not separated from red blood cells within 1 hour. d. The patient smoked three cigarettes just prior to blood collection e. The blood sample was not protected from light upon collection and during transport to the laboratory

Which of the following hormones promotes gluconeogenesis? a. Growth hormone b. Hydrocortisone c. Insulin d. Thyroxine

Glucose oxidase oxidizes glucose to gluconic acid and: a. H2O2 b. CO2 c. HCO3 d. H2O

From glucose and ATP; hexokinase catalyzes the formation of: a. Acetyl-CoA b. Fructose-6-phosphate c. Glucose-6-phosphate d. Lactose

What is the preferred specimen for glucose analysis? a. EDTA plasma b. Fluoride oxalate plasma c. Heparinized plasma d. Serum

Hyperglycemic factor produced by the pancreas: a. Epinephrine b. Glucagon c. Insulin d. Growth hormone

Polarographic methods of glucose assay are based on which principle? a. Nonenzymatic oxidation of glucose b. Rate of oxygen depletion measured c. Chemiluminescence caused by the formation of ATP d. Change in electrical potential as glucose is oxidized.

Select the enzyme that is most specific for β-Dglucose: a. Glucose oxidase b. Glucose-6-phosphate dehydrogenase c. Hexokinase d. Phosphohexose isomerase

Select the coupling enzyme used in the hexokinase method for glucose: a. Glucose dehydrogenase b. Glucose-6-phosphate c. Glucose-6-phosphate dehydrogenase d. Peroxidase

Characteristics of von Gierke disease: (1) Hypoglycemia (2) Hypolipidemia (3) Increased plasma lactate (4) Subnormal response to epinephrine a. 1, 2, and 3 b. 2, 3, and 4 c. 1, 3, and 4 d. 1, 2, and 4

The preferred screening test for diabetes in nonpregnant adults is measurement of: a. Fasting plasma glucose b. 2 hour postprandial c. Glycohemoglobin d. No one test is preferred over another for diagnosis

Following the 2015 ADA guidelines, the times of measurement of plasma glucose levels during an OGTT in nonpregnant patients are: a. Fasting, 1 hour, and 2 hours b. Fasting and 60 minutes c. 30,60, 90, and 120 minutes d. Fasting and 30, 60, 90, and 120 minutes

Monitoring the levels of ketone bodies in the urine via nitroprusside reagents provides a semiquantitative measure of: a. Acetoacetate b. 3- β-Hydroxybutyrate c. Acetone d. All three ketone bodies

A factor, other than average plasma glucose values, that can affect the HBA1c level is: a. Serum ketone bodies level b. Red blood cell life span c. Ascorbic acid intake d. Increased triglyceride levels

Monitoring the levels of ketone bodies in the urine is: a. Considered essential on a daily basis for all diabetic patients b. A reliable method of assessing long-term glycemic control c. Recommended for patients with type I diabetes on sick days d. Not recommended by the ADA

A urinalysis identifies a positive result for reducing sugars, yet the test for glucose (glucose oxidase reaction) was negative on dipstick. What do these results suggest? a. This is commonly observed with ascorbic acid interference. b. This may suggest the patient has a deficiency in galactose-1-phosphate uridyltransferase. c. This may suggest a pancreatic beta-cell tumor. d. This may suggest a deficiency in glycogen debrancher enzyme e. It is not possible to obtain these results and there is an analytic error in testing

Urinalysis of a diabetic patient identified the following: Year 1: Urine albumin was 16 mg/g creatinine Year 2: Urine albumin was 25 mg/g creatinine Year 3: Urine albumin was 40 mg/g creatinine What do these clinical data suggest? a. These levels of albumin in the urine are normal, and no follow-up is necessary b. These levels of albumin in the urine suggest that kidney function is compromised c. As these values of urinary albumin is not greater than 300 mg/g creatinine, the patient is not likely to have compromised kidney function. d. An additional urinary albumin test is required in 3 to 6 months to verify diminishing kidney function.

Which of the following statements concerning chylomicrons is false? a. The major lipid transported by this lipoprotein is cholesterol b. This lipoprotein is produced in the intestinal mucosa. c. The primary function is to carry dietary (exogenous) lipids to the liver. d. It remains at the origin (point of application) during lipoprotein electrophoresis.

Which of the following methods for lipoprotein electrophoresis depends on charge and molecular size? a. Polyacrylamide gel b. Paper c. Cellulose acetate d. Agarose

The lipoprotein that contains the greatest amount of protein is called: a. HDL b. Chylomicrons c. VLDL d. LDL

Pre-beta VLDL lipoproteins migrate further toward the anode on polyacrylamide gel than they do on cellulose acetate or agarose. a. True b. False

Several enzymatic triglyceride methods measure the production or consumption of: a. NADH b. Fatty acids c. Glycerol d. Diacetyl lutidine

The most likely cause for serum/plasma to appear “milky is the presence of: a. Chylomicrons b. VLDL c. LDL d. HDL

In the colorimetric determination of cholesterol using the enzyme cholesterol oxidase, the agent that oxidizes the colorless organic compound 4- aminoantipyrine to a pink complex is: a. Hydrogen peroxide b. Cholest-4-ene-3-one c. NAD d. Phenol

Which of the following is the major carrier of cholesterol to peripheral tissue? a. LDL b. Chylomicrons c. VLDL d. HDL

78 Increased levels of apo A-I are associated with increase risk for CAD? a. True b. False

A patient is admitted to the hospital with intense chest pains. The patient’s primary care physician requests the emergency department doctor to order several tests, including a lipid profile with cholesterol fractionation. Given the patient’s results provided below, what would be the LDL-C for this patient? Total cholesterol 400 mg/dL TAG 300 mg/dL HDL-C 100 mg/dL Lipoprotein electrophoresis Pending a. 240 mg/dL b. 160 mg/dL c. 200 mg/dL d. 300 mg/dL

Using the results obtained in question number 79, what would be the patient’s LDL-C status? a. High b. Optimal c. Desirable d. Borderline

As part of a lipoprotein phenotyping, it is necessary to perform total cholesterol and triglyceride determinations, as well as lipoprotein electrophoresis. The test results obtained from such studies were: • Triglyceride, 340 mg/dL (reference range, <150 mg/dL) • Total cholesterol, 180 mg/dL (reference range, <200 mg/dL) • Pre-beta-lipoprotein fraction increased • Beta-lipoprotein fraction normal • No chylomicrons present • Serum appearance turbid The best explanation for these results would be that the patient exhibits a phenotype indicative of: a. Type IV hyperlipoproteinemia b. Type I hyperlipoproteinemia c. Type II hyperlipoproteinemia d. Type III hyperlipoproteinemia e. Type V hyperlipoproteinemia

Which of the following results is most consistent with high risk for CHD? a. 20 mg/dL HDL-C and 250 mg/dL total cholesterol b. 35 mg/dL HDL-C and 200 mg/dL total cholesterol c. 50 mg/dL HDL-C and 190 mg/dL total cholesterol d. 55 mg/dL HDL-C and 180 mg/dL total cholesterol e. 60 mg/dL HDL-C and 170 mg/dL total cholesterol

What is the presumed defect in most cases of familial type IIa hyperlipoproteinemia? a. Defective receptors for LDL b. Deficiency of hydroxymethylglutaryl (HMG)-CoA reductase c. Deficiency of cholesterol esterase d. Deficiency of LPL e. Defective esterifying enzymes LCAT and ACAT

Hyperchylomicronemia (type I) in childhood has been associated with which of the following? a. A deficiency of apo-CII b. A deficiency of LCAT c. A deficiency of LPL d. A deficiency of apo A-I

What is the major intracellular cation? a. Potassium b. Calcium c. Magnesium d. Sodium

What is the major extracellular cation? a. Sodium b. Chloride c. Magnesium d. Calcium

Osmolality can be defined as a measure of the concentration of a solution based on the: a. Number of dissolved particles b. Number of ionic particles present c. Number and size of the dissolved particles d. Density of the dissolved particles

Hyponatremia may be caused by each of the following, EXCEPT: a. Hypomagnesemia b. Aldosterone deficiency c. Prolonged vomiting or diarrhea d. Acute or chronic renal failure

Hypokalemia may be caused by: (1) Acidosis (2) Prolonged vomiting or diarrhea (3) Hypomagnesemia (4) Hyperaldosteronism a. 1, 2, and 3 b. 2, 3, and 4 c. 1, 3, and 4 d. 1, 2, and 4

Hyperkalemia may be caused by each of the following, EXCEPT: a. Alkalosis b. Acute or chronic renal failure c. Hypoaldosteronism d. Sample hemolysis

The main difference between a direct and indirect ISE is: a. Sample is diluted in the indirect method, not in the direct method b. The type of membrane that is used c. Direct ISEs use a reference electrode, whereas indirect ISEs do not d. Whole blood samples can be measured with the direct method and not with the indirect method

Which method of analysis will provide the most accurate electrolyte results if a grossly lipemic sample is used? a. Direct ISE b. Indirect ISE c. Flame emission photometry d. Atomic absorption

The most frequent cause of hypermagnesemia is due to: a. Renal failure b. Increased intake of magnesium c. Hypoaldosteronism d. Acidosis

A hemolyzed sample will cause falsely increased levels of each of the following, EXCEPT: a. Sodium b. Potassium c. Phosphate d. Magnesium

The largest portion of total body water is found in which tissue? a. Intracellular fluid b. Extracellular fluid c. Intravascular and extracellular fluid d. Interstitial fluid e. Plasma

Osmoreceptors in the hypothalamus are key to regulating blood osmolality. Typically, a 1% to 2% shift in osmolality causes a ______ change in circulating concentration of AVP. a. Twofold b. Fourfold c. Eightfold d. Tenfold