Clinical Chem Test Bank Final Exam

Clinical Chem Test Bank (Final Exam) 1. In which of the following disorders would the maternal serum level of 1-fetoprotein be elevated? A. Neural tube defect. B. Cardiac ischemia. C. Down syndrome. D. Small cell lung carcinoma 2. Which of the following is FALSE about PSA? A. It is a single-chain glycoprotein B. It is used as a tumor marker C. It is not elevated in benign prostatic hyperplasia D. It is quantified in serum by immunoassays 3. Which of the following biomarkers is elevated in nonmucinous epithelial ovarian cancer? A. CA 15-3 B. CA 19-9 C. CA 125 D. CEA 4. Which of the following is a sialylated Lewis blood group antigen associated with colorectal cancer? A. CA 125 B. CA 15-3 C. PSA D. CA 19-9 5. Which of the following biomarkers are elevated in advanced stages of breast cancer? A. Total and free PSA B. CEA and alpha-fetoprotein C. CA 15-3 and CA 549 D. DUPAN-2 and Gastrin 6. Which tumor marker is associated with cancer of the urinary bladder? A. CA 125 B. CA19-9 C. CA 50 D. Nuclear matrix protein 7. What is the primary clinical usefulness of measuring carcinoembryonic antigen? A. Diagnosis of lung cancer B. Diagnosis of colorectal cancer C. Screening for breast cancer D. Monitoring for recurrence of colon cancer 8. Which of the following is used to assess the usefulness of trastuzumab (Herceptin®) therapy for breast cancer? A. CA 15-3 B. HER-2/neu C. CA 125 D. Prolactin 9. Which type of hCG test would be most useful to assess a person suspected of having testicular cancer? A. Plasma immunoassay for intact hCG and the β-hCG subunits B. Plasma immunoassay fro the free alpha and β-hCG subunits C. Urine assay for hCG-β core D. Plasma immunoassay for intact hCG only 10. A markedly elevated serum AFP is associated with which of the following? A. Ovarian cancer B. Lung cancer C. Hepatoma D. Breast cancer 11. Which of the following assays is recommended as a screening test for colorectal cancer in persons over 50 years of age? A. Fecal typsin B. AFP C. BTA D. Occult blood t test 12. Which of the following must be determined to calculate diagnostic specificity? A. True-negatives and false-positives B. True-positives and false-positives C. True-positives and false-negatives D. True-negatives and false-negatives 13. A new tumor marker assay for prostate specific antigen (PSA) is evaluated for sensitivity by testing serum samples from patients who have been diagnosed as having prostate cancer. The following results were obtained: Number of prostate cancer patients who tested positive by the new assay = 42 out 46 Number of patients who did not have cancer and tested negative by the new assay = 31 out of 32 What is the sensitivity of the new assay for PSA? A. 98.0% B. 95.0% C. 91.3% D. 88.5% 14. Which statement below best describes the molecular difference between free PSA (fPSA) and complex PSA (cPSA)? A. Free PSA is bound by compounds such as ACT, PCI, API, or AMG B. Free PSA is an active form that can complex with protease inhibitors C. Free PSA is not bound by compounds such as ACT, PCI, API, or AMG D. Free PSA cannot be detected in serum, whereas complex PSA can 15. The production of alpha fetal protein (AFP) in a healthy individual is best reflected by which of the following statements? A. The production of AFP remains the same through life B. The production of AFP declines rapidly at birth and healthy adults and children have negligible or undetectable levels in serum C. The production of AFP declines rapidly at birth and healthy adults and children have higher than normal levels in serum D. The production of AFP declines rapidly at birth and healthy adults and children have negligible or undetectable levels in serum 16. The combination of squamous cell carcinoma antigen (SCCA) and CYFRA 21-1 test results can be used to provide reliable laboratory data for the differential diagnosis of which disease? A. Nonsquamous cell lung carcinoma B. Pancreatic cancer C. Liver cancer D. Pulmonary embolism 17. A new test for breast cancer is found to have a sensitivity of 85.0% and a specificity of 90.0%. If the prevalence of breast cancer is 3.5% in women over 45 years old, what is the predictive value of a positive test result (PV+) in this group? A. 60.0 B. 50.5 C. 30.0 D. 23.6 18. Nuclear matrix protein-22 (NMP) is a tumor marker designed for what purpose? A. Test for recurrence of bladder cancer B. Test for recurrence of lung cancer C. Test for recurrence of bone cancer D. Test for recurrence of colorectal cancer 19. Which molecular form(s) is/are measured by an intact β-hCG assay? A. hCG core and "nicked" hCG or hCGn B. The whole molecule C. Only "nicked" hCG or hCGn D. α-hCG and free β-hCG subunits 20. Diagnostic specificity is defined as which of the following? A. The probability that a laboratory test will be positive in the absence of disease B. The probability that a laboratory test will be negative in the absence of disease C. A measure of how often the assay system detects the biomarker when the disease is present D. The probability that a disease is present when the test is positive or that a disease is absent when a test is negative 1. Which of the following electrolyte measurements would be of clinical usefulness to the clinician who is treating patients for pregnancy-induced hypertension? A. Ionized calcium B. Potassium C. Magnesium D. Phosphorus 2. Ionized or free calcium is clinically useful for which of the following reasons? A. It is the best indication of phosphate status because it is biologically active and tightly regulated by PTH and Vitamin D. B. It is the best indication of calcium status because it is biologically active and tightly regulated by thyroid hormones. C. It is the best indication of calcium status because it is biologically inactive and tightly regulated by PTH and Vitamin D. D. It is the best indication of calcium status because it is biologically active and tightly regulated by PTH and Vitamin D. 3. Free ionized calcium normally represents approximately what percentage of the total serum calcium? A. 5% B. 40% C. 50% D. 80% 4. Which of the following reagents is used to determine the concentration of serum inorganic phosphate? A. Biuret B. Bathophenanthroline C. Ammonium molybdate D. Malachite green 5. Monitoring intraoperative PTH is useful for: A. Surgical management of primary hyperparathyroidism. B. Surgical management of thyroid disease. C. Surgical management of prostate cancer. D. Surgical management of coronary heart disease. 6. Which of the following can affect the concentration of ionized calcium in blood? A Barometric pressure B. pH and temperature C. Magnesium concentration D. Partial pressure of carbon dioxide 7. If the pH of a sample decreases, what is the predicable response to the serum magnesium concentration? A. The concentration will increase 1 mmol/L for each whole unit of pH change B. The concentration will not be altered C. The concentration will decrease D. The concentration will increase 8. Which of the following statements best illustrates the diagnostic criteria for primary hyperparathyroidism? A. No serum PTH detected and no serum calcium detected B. Detectable amounts of serum PTH concomitant with elevated total serum calcium C. Elevated total serum calcium only D. A normal levels of serum PTH and serum calcium 9. Which of the following feedback mechanisms regulate the production of 1, 25(OH) 2D3? A. Negative feedback mechanism associated with circulating levels of calcium and inorganic phosphorus. B. Negative feedback mechanism associated with circulating levels of calcitonin. C. Negative feedback mechanism associated with circulating levels of magnesium. D. Positive feedback mechanism associated with circulating levels of calcium and inorganic phosphorus. 10. Which of the following is an effect of increased parathyroid secretion? A. Decreased intestinal absorption of calcium B. Increased intestinal absorption of calcium C. Decreased blood calcium levels D. Decreased bone resorption