MLT ASCP Chemistry Practice Questions

Match deficiency states with their respective vitamins. Select the correct match 1. Night blindness 2. Beriberi 3. Rickets 4. Scurvy A. Thiamine B. Vitamin A C. Vitamin C D. Vitamin D

1. B 2. A 3. D 4. C Thiamine deficiency can cause Beriberi. Vitamin C deficiency can cause Scurvy. Vitamin A deficiency can cause night blindness. Vitamin D deficiency can cause rickets.

Match the tumor markers below with their corresponding sites of tumor origin. 1. Colon 2. Prostate 3. Liver 4. Testicles A. PSA B. Alpha-fetoprotein C. Beta HCG D. CEA

1. D 2. A 3. B 4. C PSA, or prostate specific antigen = Prostate CEA, or Carcinoembryonic Antigen = Colon beta hCG, or Human chorionic gonadotropin = Testicles AFP, or Alpha-fetoprotein = Liver

Serum proteins can be separated by cellulose acetate electrophoresis into how many basic fractions: Please select the single best answer A. 4 fractions B. 5 fractions C. 6 fractions D. 7 fractions

B; The five basic fractions are albumin, alpha-1, alpha-2, beta, and gamma globulins.

While serum elevations are NOT generally seen in early stages, which of the following tumor markers are elevated in more advanced stages of breast cancer? Please select the single best answer A. CEA and AFP B. AFP and CA 125 C. PSA and CA 15-3 D. CA 15-3 and CA 549

D; CA 15-3 is also known as CA-breast as it is specifically associated with breast cancer. CA 549 is a glycoprotein found in the serum of breast cancer patients as well. CEA, or carcinoembryonic antigen, is used mainly to monitor the treatment of cancer patients, particularly those with colon cancer. AFP, or alphafetoprotein, is found in elevated levels in primary liver cancer or germ cell tumor. CA 125 is usually used to detect ovarian cancer and also used to monitor therapy. PSA, or prostate specific antigen, is used in the detection of prostate cancer.

That portion of an enzyme which is separated from its cofactor is called a(n): Choose the single best answer A. Partial enzyme B. Isoenzyme C. Coenzyme D. Apoenzyme

D; A partial enzyme is not an actual term used in the laboratory. An isoenzyme is a related enzyme with a different chemical structure. Finally, a coenzyme is a non-protein molecule (often a vitamin) that helps an enzyme become active.

Which of the following serum constituents is unstable if a blood specimen is left standing at room temperature for eight hours before centrifugation and processing? Please select the single best answer A. Cholesterol B. Triglyceride C. Creatinine D. Glucose

D; Glucose is utilized by red blood cells even after blood collection. Therefore, the glucose levels will decline over time if left standing for extended periods of time.

Which enzyme is responsible for the conjugation of bilirubin? Please select the single best answer A. Beta-Glucuronidase B. Bilirubin oxidase C. Bilirubin reductase D. Glucuronyl transferase

D; Glucuronyl transferase is responsible for the conjugation of bilirubin in the liver. When deficiencies exist of this important enzyme, disease states can occur. A deficiency in glucuronosyl transferase is thought to be the cause of Gilbert's syndrome (unconjugated hyperbilirubinemia) and Crigler-Najjar syndrome, where this enzyme is completely or mostly absent.

Which one of the following are not associated with a polyclonal (broadbased) increase in gamma globulins? Please select the single best answer A. Liver disease B. Chronic inflammation C. Immune reaction D. Immunodeficiency

D; Immunodeficiency would, of course, generally be associated with a decrease in serum immunoglobulin levels, and an associated decreased gamma band.

A; There is a broad based increase in the gamma band, corresponding to polyclonal hypergammaglobulinemia, as seen in chronic inflammation as well as an increase in the alpha-1 and alpha-2 regions.

This serum protein electrophoresis scan most likely represents which condition? Choose the single best answer A. Chronic inflammation B. Myocardial infarction C. Liver disease D. Monoclonal gammopathy

B; According to the NCEP: ATP III diagnostic criteria, this patient does not have metabolic syndrome. She has only two parameters outside the criteria limits: waist circumference and HDL-C. She does need to lose weight though because she does seem to have increased upper body fat according to the waist circumference measurement. This may eventually cause an increased triglyceride, increased blood glucose, and/or hypertension and metabolic syndrome diagnosis along with an increased risk for cardiovascular disease.

A physician discusses weight with an overweight 60-year-old female at her yearly physical appointment. The female exercises regularly and eats healthy most of the time. The physician suggests she decrease carbohydrate intake and decrease portion size at meals. Review patient vital signs and laboratory assay results to decide if a diagnosis of metabolic syndrome is appropriate using the NCEP:ATP lll Diagnostic Criteria shown on the right. Height: 5' 7' Weight: 192 lbs BMI: 30.1 Waist Circumference: 37 inches Blood Pressure: 108/70 Fasting Blood Glucose: 92 mg/dL Total Cholesterol: 172 mg/dL LDL-C: 112 mg/dL HDL-C: 46 mg/dL Triglycerides: 70 mg/dL hs-CRP: <1.0 mg/L Which of these statements regarding this patient is true? Please select the single best answer A. This patient meets the criteria for diagnosis of metabolic syndrome. B. This patient does not meet the criteria for diagnosis of metabolic syndrome.

Acute phase proteins generally fall into which category? Please select the single best answer A. Glycoproteins B. Immunoglobulins C. Lipoproteins D. Microglobulins

A; Acute phase proteins are a large group of glycoproteins found in the blood that are not related to immunoglobulins. Acute-phase proteins are generally a class of glycoproteins whose plasma concentrations increase, known as positive acute-phase proteins, or decrease, known as negative acute-phase proteins, in response to inflammation.

An automated method for measuring chloride which generates silver ions in the reaction is called: Choose the single best answer A. Coulometry B. Potentiometry C. Chromatography D. Polarography E. Densitometry

A; Coulometry operates on the principle of Faraday's law in which a silver anode releases silver ions (titration) at a constant rate when a constant potential is applied. The silver ions react with chloride in a fixed volume of solution to form silver chloride. The time it takes for the chloride in the unknown solution to react with the silver ions is proportional to the chloride activity in the sample.

A 56 year old female was taken to the emergency room in a coma by her employer's nurse. She had lost 35 pounds in 3 months; she was always thirsty; drinking a lot of water and running to the bathroom. The following are her laboratory results: Results: (indicates reference range) pH: 7.11 (7.35-7.45) pCO2: 21 mm Hg (35-45 mm Hg) Glucose: 950 mg/dL (60-110 mg/dL) Serum osmolality: 365 mOsm/Kg (275-295 mOsm/Kg) Urine ketone: strongly positive (negative) Urine glucose: strongly positive (negative) What is the MOST likely cause of this patient's symptoms? Choose the single best answer A. gestational diabetes B. diabetes insipidus C. insulin dependent diabetes mellitus D. type II diabetes mellitus

A; Insulin dependent diabetes mellitus is associated with a lack of insulin, which leads to increased blood and urine glucose. The classical symptoms of polyuria (frequent urination), polydipsia (increased thirst), polyphagia (increased hunger), and weight loss. Since this patient had not been diagnosed and appears to be poorly controlled, she developed hyperosmotic non-ketotic coma (HONK) which lead to her acidosis and elevated osmolality. The ketones and glucose in the urine indicate that the body is not able to use the glucose present, since there is a lack of insulin, and that the body is using fat for its source of energy instead. Gestational diabetes occurs in pregnant women and would not cause the laboratory results shown here. In addition, gestational diabetes since it would be very unlikely that a 56-year-old would be pregnant. Diabetes insipidus is a condition where the body is unable to reabsorb water in the kidneys. This type of diabetes is associated with an increased thirst and cravings for ice, along with very high volumes of diluted urine. However, diabetes insipidus can be ruled out due to the presence of glucose in the urine. Diabetes insipidus patients usually do not exhibit positive urine glucose results. Those suffering from type II diabetes mellitus do not typically show ketosis. Type II diabetes mellitus is usually not associated with ketonuria or ketoacidosis. Therefore, the best choice in this case is insulin dependent diabetes mellitus.

Select the true statement regarding lipids and heart disease. Choose the single best answer A. Increased level of LDL-C indicates an increased risk for cardiovascular disease B. Increased level of HDL-C indicates an increased risk for cardiovascular disease C. Lipids are not involved in atherosclerotic plaque formation D. Lipids are no longer measured in evaluating cardiac disease risk

A; It is now known that atherosclerosis formation is primarily an inflammatory process but lipids do play a role in the process. Increased blood levels of LDL-C indicates a greater risk for atherosclerosis. An increased level of HDL-C is not associated with an increased risk for cardiovascular disease. In fact, the HDL lipoprotein plays a role in reducing lipid levels in the blood."

Which of the following conditions would make a sample unsuitable for lactic acid testing? Choose the single best answer A. Movement of hand or arm during specimen collection B. Received in the lab on ice C. Centrifuged in a refrigerated centrifuge D. Specimen centrifuged and plasma separated from cells less than 15 minutes after collection

A; Movement of the muscles in the hand or arm during specimen collection will falsely increase lactic acid concentration. A blood sample for lactic acid testing should be placed on ice immediately after collection, centrifuged within 15 minutes of collection, and plasma immediately separated from cells following centrifugation. If possible, a refrigerated centrifuge should be used.

Which of the following would you find in a primary hyperparathyroidism case? Please select the single best answer A. elevated serum calcium and decreased serum phosphorus B. elevated serum calcium and elevated serum phosphorus C. decreased serum calcium and decreased serum phosphorus D. decreased serum calcium and increased serum phosphorus

A; Primary hyperparathyroidism is a disorder of the parathyroid glands where overactive parathyroid glands secretes too much parathyroid hormone (PTH). This excess PTH triggers the release of too much calcium into the bloodstream. The bones may lose calcium, and too much calcium may be absorbed from food. The levels of calcium may increase in the urine, causing kidney stones. PTH also lowers blood phosphorus levels by increasing excretion of phosphorus in the urine.

According to the National Diabetes Data Group recommendations, which of the following statements is TRUE with regards to the following findings? Fasting glucose = 130 mg/dl 2-hour post prandial glucose = 210 mg/dl Please select the single best answer A. The patient may be diagnosed as having diabetes mellitus B. The patient is diagnosed as having impaired glucose tolerance C. The patient is diagnosed as having diabetes insipidus D. The patient is normal

A; The National Diabetes Data group recommends that the diagnosis of diabetes mellitus be based on two fasting plasma glucose levels of 126 mg per dL (7.0 mmol per L) or higher. Other options for diagnosis include two two-hour postprandial plasma glucose (2hrPPG) readings of 200 mg per dL (11.1 mmol per L) or higher after a glucose load of 75 g or two casual glucose readings of 200 mg per dL or higher. Measurement of the fasting plasma glucose level is the preferred diagnostic test, but any combination of two abnormal test results can be used.

Which of the following contributes to specific gravity but does NOT contribute to osmolality? Choose the single best answer A. protein B. NaCl C. urea D. glucose

A; The presence of large amounts of protein and glucose will alter the specific gravity and should be considered when interpreting specific gravity results. Osmolality measures the analytes in the following equation- note that protein is not included in the calculation of osmolality. Osmolality = 1.86 Na + (Glucose/18) + (BUN/2.8) + 9 (or) 1.91 Na + (Glucose/15) + (BUN/2.25).

A patient has a fasting plasma glucose (FPG) performed at an outpatient laboratory. He has fasted as instructed. FPG: 135 mg/dL What does this result indicate and what, if any, further action is recommended by the ADA? Please select the single best answer A. Elevated FPG; needs further evaluation by a repeat or alternative test B. Decreased FPG; a repeat of the test is recommended in one year C. Sufficient documentation for diagnosis of diabetes D. Needs no further evaluation; this is a normal FPG

A; The result is elevated. Hyperglycemia is demonstrated by this one FPG. The ADA recommends that the hyperglycemia be demonstrated a second time by repeating the FPG or by using one of the other recommended diagnostic tests. Hyperglycemia should be demonstrated a second time by any of the four criteria unless the glucose level is significantly high and diabetes is unquestionable.

Which of the following enzymes is the most sensitive indicator of liver damage associated with alcohol ingestion: Please select the single best answer A. GGT B. ALT C. AST D. LDH

A; GGT elevations precede those of other liver enzymes in cases of chronic ingestion of drugs or alcohol.

A low CSF glucose level is associated with all the following except: Choose the single best answer A. Hyperglycemia B. Fungal meningitis C. Toxoplasmosis D. Hypoglycemia

A; In hyperglycemia you would expect a normal or elevated CSF glucose level- this question is asking where you would expect to see a decreased (low) CSF glucose level, and in this case hyperglycemia would be the one condition that is excluded (therefore the correct answer).

Which one of the following statements about acetaminophen metabolism is false? Choose the single best answer A. It is metabolized in the kidney B. It is largely metabolized in the liver to glucuronide and sulfonate conjugates C. A small amount is metabolized via cytochrome oxidase to a reactive benzoquinoneimine intermediate D. This intermediate becomes toxic to the liver once tissue glutathione becomes depleted

A; The benzoquinoneimine intermediate produced in the liver as a result of hepatic cytochrome oxidase metabolism of acetaminophen is responsible for hepatic necrosis via acylation of hepatic tissue. The treatment of acetaminophen toxicity includes the use of N-acetylcysteine (Mucomyst), which acts as a glutathione substitute. The risk of hepatotoxicity is predicted with the Rumack-Matthew nomogram, which uses the hours after ingestion and plasma acetaminophen level to predict the probability of hepatotoxicity. Severe hepatotoxicity can be fatal.

When evaluating a patient for a suspected Wilson's Disease diagnosis, low values of plasma ceruloplasmin would be expected along with: Choose the best answers: more than one answer applies A. Decreased urine copper B. Increased urine copper C. Normal urine copper D. Decreased serum copper E. Increased serum copper

B&D; Ceruloplasmin is the main copper transporting protein in the blood. Although there are other conditions (not listed) that can cause a low ceruloplasmin value (i.e., Menkes disease, overdose of Vitamin C, etc.), the best answers of those given for this question is increased urine copper and decreased serum copper. Ceruloplasmin is primarily ordered along with serum and/or urine copper tests to help diagnose Wilson disease, an inherited disorder associated with decreased levels of ceruloplasmin and excess storage of copper in the liver, brain, and other organs. Though there is an increased level of deposited copper throughout the body, the serum copper levels are paradoxically low with a characteristic increase in urine copper levels that aid in this diagnosis.

Which of the following is true of genotype screening in pharmacogenomics? Choose the single best answer A. Genotype screening gives a better overall picture of drug metabolism than measuring metabolism with probe drugs. B. Genotyping does not take into account drug interactions which can affect metabolism. C. Genotyping typically involves measuring only one mutation site or polymorphism.

B; Genotyping, while more robust and definitive, cannot factor in environmental or health variables that could affect drug metabolism. Probe drug analysis does factor in these variables, but it is more complex and tedious. Genotyping typically involves measuring many polymorphisms. For example, a laboratory that offers CYP2D6 profiling may measure twelve of the most common and significant mutation sites on this enzyme.

Which adipokine is synthesized and released by adipocytes and many other body cell types, is an inflammatory cytokine that stimulates the liver to produce C-reactive protein (CRP), and is increased in obesity and insulin resistance? Choose the single best answer A. Leptin B. IL-6 C. Adiponectin D. Angiotensinogen

B; IL-6 is synthesized and released by adipocytes and many other body cell types, is an inflammatory cytokine that stimulates the liver to produce C-reactive protein (CRP), and is increased in obesity and insulin resistance.

When is a trough blood sample for therapeutic drug monitoring usually obtained? Please select the single best answer A. Just after the dose is administered B. Just before the next scheduled dose C. At the peak time calculated after a dose D. After one half-life of the drug

B; A trough blood sample for therapeutic drug monitoring is usually obtained just before the next scheduled dose.

Which of the following conditions should be suspected given the following set of serum laboratory results? Amylase 650 U/L Lipase 1200 U/L Choose the single best answer A. Cystic Fibrosis B. Pancreatitis C. Myocardial Infarction D. Multiple Myeloma

B; Both acute and chronic pancreatitis are associated with increased serum amylase and lipase levels, often 5-10 times the normal range. Since the reference ranges for amylase and lipase are approximately: 53 - 123 U/L and 10 - 150 U/L respectively, the values shown in this case are increased. Cystic Fibrosis can actually cause a decreased serum lipase level, while myocardial infarctions and multiple myeloma will have little effect on serum amylase and lipase levels.

Which of the following statements about the test for C-reactive protein (CRP) is TRUE? Please select the single best answer A. It correlates with neutrophil phagocytic function B. It is an indicator of an inflammatory condition C. It is diagnostic for rheumatic fever D. It is part of the complement cascade

B; C-reactive protein is produced by the liver. The level of CRP rises when there is inflammatory processes happening in the body.

Which of the following is found in plasma but absent in serum: Please select the single best answer A. Proteins B. Fibrinogen C. Red blood cells D. White blood cells

B; Fibrinogen, is, of course, consumed during the clotting process.

Sodium fluoride is an excellent preservative for collecting glucose specimens because: Choose the single best answer A. Prevents interference with other substances B. Inhibits glycolysis C. Enhances chemical reactions D. Inhibits certain clotting factors

B; Glucose is metabolized at a rate of 5% per hour in specimens not immediately separated or collected in sodium fluoride or iodoacetate.

Which of the following electrolytes is most likely to be spuriously elevated in a hemolyzed specimen: Choose the single best answer A. Sodium B. Potassium C. Chloride D. BUN

B; Potassium has the highest RBC to serum concentration ratio: approximately 23:1.

Select the primary reagent components used in the Jaffe reaction for creatinine. Please select the single best answer A. Alkaline copper (II) sulfate B. Saturated picric acid and sodium hydroxide C. Sodium nitroprusside and phenol D. Phosphotungstic acid

B; Saturated picric acid and sodium hydroxide are the main reagents used in the Jaffe reaction for creatinine determination. These chemical components usually cause the creatinine reagent to have a bright yellow color.

A serum sample is received in the clinical chemistry department of the laboratory. The first time the sample is assayed, the result is 600 mg/dL. To verify this result (following this hospital's policy), the tech makes 2 mL of a 1:2 dilution of the original sample. If only 1 mL of this sample is analyzed, what would the result be? Assume that the original 600 mg/dL value was accurate and that the instrument did not automatically perform a dilution calculation. Choose the single best answer A. 100 mg/dL B. 300 mg/dL C. 600 mg/dL D. 1100 mg/dL E. Not enough information given

B; The correct response is option B: 300 mg/dL. A 1:2 dilution of a sample that originally contained 600 mg for every one deciliter would now contain only 300 mg for every deciliter. In other words, it is 1/2 as concentrated as the original sample. The volume of that sample that is then analyzed has no bearing on the concentration read by the instrument. One could assay 10 microliters or the full 2 ml from the problem and the concentration would remain 300 mg/dl. Concentration is independent of the volume assayed.

Which analyte measurement is used to detect early nephropathy in a diabetic patient? Choose the single best answer A. Lactic acid B. Microalbumin C. Ketones D. HbA1C

B; The detection of small concentrations of albumin (microalbumin) in the urine is used to detect early renal impairment.

A drug that is administered through which of the following routes will reach peak level the quickest? Choose the single best answer A. Oral B. Intravenous (IV) C. Intramuscular (IM)

B; A drug that is administered IV will reach peak level the quickest (15 - 30 minutes after injection/infusion). A drug that is injected IM will reach peak level at 30 minutes to one hour after injection; a drug that is taken orally will reach peak level approximately one hour after the drug is taken (if the half-life is > two hours).

D; The bioavailability of an oral drug is the fraction of the drug that is absorbed into systemic circulation. The bioavailability of a drug is calculated by comparing the area under the plasma concentration-time curve of an equivalent dose of the intravenous form and the oral form of the drug. For oral drugs to be effective, bioavailability typically should be greater than 70%.

Bioavailability of an oral drug refers to the Please select the single best answer A. availability for therapeutic administration B. ratio of protein-bound to free drug C. amount of drug transformation D. fraction of the drug that is absorbed into systemic circulation

How long does it take for plasma concentrations to reach steady state when a patient's dose is given at intervals of the drug's half-life? Please select the single best answer A. one half-hour B. two-half lives C. 4-7 half-lives D. 10-12 half-lives

C; As repeated doses of a drug are given to a patient, the drug's plasma concentration accumulates and reaches a steady state. This is when the amount of drug in the plasma has built up to a concentration level that is therapeutically effective and as long as regular doses are administered to balance the amount of drug being cleared the drug will continue to be active. The time taken to reach the steady state is about five-seven times the half life of a drug.

Which assay is performed to diagnose congestive heart failure (CHF)? Please select the single best answer A. Homocysteine B. hs-CRP C. BNP D. cTnI E. Ischemia Modified Albumin F. cTnT

C; BNP is elevated in CHF patients. Cardiac troponins are measured to diagnose an AMI and homoscysteine, hs-CRP, and ischemia modified albumin are markers of risk for cardiac disease.

Which of the following disorders is characterized by increased production of chloride in sweat? Please select the single best answer A. Multiple myeloma B. Hypoparathyoidism C. Cystic fibrosis D. Wilson's disease E. Down Syndrome

C; In cystic fibrosis, individuals have problems with decreased salt, and hence, water levels in their lung surfactent. They also have problems with salt absorption in the sweat ducts which causes them to produce extremely salty sweat, with a high chloride level. Sweat chloride testing is still the gold standard for screening for cystic fibrosis.

All of the following are characteristics of Type II diabetes mellitus EXCEPT: Choose the single best answer A. Insulin levels may or may NOT be abnormal. B. more common than Type I diabetes. C. requires insulin therapy to control hyperglycemia. D. associated with obesity and more common in persons greater than 40 years old. E. a and d

C; In type I diabetes mellitus, patients have deficiency in producing insulin from the beta cells in the islets of Langerhans of the pancreas. In this type of diabetes, patients are often given exogenous insulin therapy to control hyperglycemia. Type II diabetes mellitus involves the body's unresponsiveness to insulin, in which exogenous insulin therapy does not commonly treat the condition.

Which of the following conditions is most likely when an oligoclonal band is seen in CSF electrophoresis without a corresponding serum peak? Choose the single best answer A. Lymphoproliferative disorder B. Meningitis C. Multiple sclerosis D. Traumatic lumbar puncture

C; Oligoclonal bands are found in the CSF of most patients with multiple sclerosis.

Mrs. Jones, a diabetic, is admitted to the hospital on November 25th. It appears that she has had an AMI but did not feel the severe chest pain because of diabetic neuropathy. She has not felt well since November 20th and her physician believes she possibly had an AMI on November 20th. Assuming that the infarct was uncomplicated, which of the following cardiac biomarkers would most likely still be elevated and would assist in an AMI diagnosis? Choose the single best answer A. Myoglobin B. Creatine kinase MB (CK-MB) C. Troponin T

C; Troponin T remains elevated after an AMI for 10-14 days, with an initial elevation within 2-4 hours after onset of myocardial necrosis. Myoglobin returns to normal range within 24-36 hours and CK-MB is back to normal range in 48-72 hours, so neither could be used in this case.

A patient has optimal LDL and HDL cholesterol values but an hsCRP test shows a value of 12 mg/L (low cardiovascular risk < 1.0 mg/L). Which is likely? Please select the single best answer A. The patient has a masked lipid problem such as metabolic syndrome. B. The patient has not been fasting. C. The patient has an underlying acute inflammation process.

C; hsCRP values >10 mg/L usually signify an underlying acute inflammation such as infection. The cardiovascular risk value of hsCRP is void and uninterpretable when levels reach this high. The optimal HDL and LDL may indicate that the patient has been fasting. However, fasting does not affect the hsCRP test.

Which of the following is a cause of metabolic alkalosis? Please select the single best answer A. Late stage of Salicylate poisoning B. Uncontrolled diabetes mellitus C. Renal failure D. Excessive vomiting E. Polyuria

D; Metabolic alkalosis may be caused by several conditions, of which one is excessive vomiting. Other causes are (1) loss of hydrogen ions in renal acid losses that exceed acid production from cellular metabolism, (2) disproportionate chloride loss compared with HCO3 loss (ie, the plasma concentration of HCO3 increases upon restriction to a smaller space of distribution), and (3) HCO3 administration (unusual because additional HCO3 is very quickly eliminated by the kidneys).

You are working in a clinical chemistry laboratory and are analyzing a plasma glucose sample. The sample is flagged by the analyzer for being "outside of linear range." You manually dilute the sample 1:2 and rerun it. Again, you receive an "outside linear range" alert. You decide to perform a different manual dilution. This time you manually dilute the original sample again; this time using a 1:3 dilution. The instrument gives you a glucose value of 150 mg/dL from this diluted sample. What is the actual patient glucose result that you should report to the physician? Choose the single best answer A. 100 mg/dL B. 400 mg/dL C. 600 mg/dL D. 450 mg/dL E. 1200 mg/dL

D; The correct response is option D: 450 mg/dl. A 1:3 dilution entails mixing one part patient sample with two parts diluent, for a total volume of 3 parts. In laboratory dilutions, the total volume is considered a dilution factor. The dilution factor in this question is 3. So a diluted sample with a value of 150 would need to be multiplied by 3 to obtain the correct final answer. 150 x 3 = 450 mg/dl.

Which assay using 24-hour urine is considered the BEST single screening test for pheochromocytoma? Choose the single best answer A. catecholamines B. vanillylmandelic acid (VMA) C. Homovallic acid (HVA) D. Metanephrines E. 5-hydroxyindole acetic acid

D; The most reliable screening tests for diagnosis of pheochromocytoma is measurement of plasma-free fractionated metanephrines and urinary fractionated metanephrines. A pheochromocytoma is a rare, catecholamine-secreting tumor that may precipitate life-threatening hypertension; Pheochromocytomas usually develop in the small glands on top of the kidneys (adrenal glands). They most commonly affect people between the ages of 20 and 50, but can occur at any age. Because of hormones secreted, symptoms include high blood pressure, sweating, rapid heartbeat, and headache. Surgery to remove the tumor is usually required.

When should blood samples for trough drug levels be collected? Choose the single best answer A. 30 minutes after peak levels B. 45 minutes before the next dose C. 1-2 hours after the last dose D. immediately before the next dose is given

D; The trough drug level is drawn immediately before the next dose is given as the drug level is expected to be the lowest in the body at this point.

Blood lactic acid concentration is an indicator of impaired circulation and tissue oxygenation in critically ill patients. If circulation and tissue oxygenation are impaired, blood lactic acid concentration will decrease below the lower end of the established reference range. True/False

False; Lactic acid will increase. When cells do not receive enough oxygen because they are not receiving enough blood, they release excess lactic acid into the bloodstream. Organ failure as a result of septic shock may be indicated by unexplained metabolic acidosis (low blood pH and low bicarbonate level) and extremely elevated lactic acid, where blood pH is <7.30 and plasma lactic acid is >1.5 times the upper limit of the laboratory's established reference values.

Gestational diabetes is diagnosed with the same testing and criteria used for the diagnosis of diabetes for a nonpregnant adult. True/False

False; The diagnostic testing used for diabetes during pregnancy is different. There are different screening tests for gestational diabetes and an OGTT is used to confirm diagnosis.

According to the 2010 ADA guidelines, HbA1C percent can be used as an assay to diagnose diabetes. True/False

T; The 2010 ADA Clinical Practice Recommendations added measurement of HbA1C as a diagnostic assay for diagnosis of diabetes.