Endocrinology/Toxicology
Estriol levels in conjunction with hCG, inhibin A (inhA), and alpha-fetoprotein (AFP) can be obtained during pregnancy to:
Assess the risk of Down's syndrome
The measurement of 17-ketosteroids (17-KSs) in urine is performed to assess PRIMARILY which organ(s)?
Testes and adrenal cortex
What blood alcohol concentration has been established as the statutory limit for operation of a motor vehicle in the United States?
80 mg/dL
The De Ritis ratio is the calculation of AST/ALT and is used for evaluating liver disease. What should the ratio be when ethanol-related liver disease is expected?
>2.0
A Cytochrome P450 2D6 (CYP2D6) ultrarapid metabolizer (UM) would require ___________ dose of an active drug (non-prodrug) that is metabolized by CYP2D6 than a CYP2D6 extensive metabolizer (EM).
A higher
All of the following hormones increase or decrease plasma glucose concentration by regulating glycogenolysis (converting glycogen to glucose) EXCEPT?
Cortisol
An elevated level of which of the following hormones will inhibit pituitary secretion of adrenocorticotropic hormone (ACTH)?
Cortisol
Pheochromocytoma is a tumor of the adrenal medulla that results in elevated urinary levels of all the following EXCEPT:
Cortisol
A patient is suspected of having Cushing's syndrome. His doctor is ordering a cortisol level. Which of the following are true about the diurnal variation of cortisol levels in blood?
Cortisol levels are higher in the morning
A patient with truncal obesity, hypertension, a ruddy/striated complexion and mood swings has multiple elevated glucose values. A fasting ACTH sample is also elevated. The physician orders a dexamethasone test, which shows an elevated cortisol level (no suppression). What is the most likely cause of the patient's values and symptoms?
Cushing Syndrome
Ninety-nine percent of lead absorbed in the body is taken up by what after absorption?
Erythrocytes
Which of the following is a component of antifreeze that can cause severe renal tubular damage, along with similar effects of alcohol poisoning?
Ethylene glycol
Cholesterol is used by the body for which of the following functions?
Precursor of hormone synthesis
Human chorionic gonadatropin (hCG) is used in the determination of:
Pregnancy
Fluorometers are designed so that the path of the excitation light is at a right angle to the path of the emitted light. What is the purpose of this design?
Prevent incident light from striking the detector
Which of the following choices is correct when describing the principles of competitive radioimmunoassay procedures?
Which of the following choices is correct when describing the principles of competitive radioimmunoassay procedures?
The ultimate end product of both epinephrine and norepinephrine metabolism is:
Vanillylmandellic acid (VMA)
What is the effect of aging with the hormones of the endocrine system?
What is the effect of aging with the hormones of the endocrine system?
How does Aspirin (salicylic acid) affect platelet function?
Inhibiting cyclooxygenase
All of the following hormones stimulate gluconeogenesis, the formation of glucose from noncarbohydrate sources such as amino acids, glycerol, and fatty acids, EXCEPT?
Insulin
Which of the following hormones is mainly responsible for the entry of glucose into the cell for energy production?
Insulin
Which one of the following statements about thyroid-stimulating hormone (TSH) is true?
It is decreased in hyperthyroidism
Which one of the following statements about acetaminophen metabolism is false?
It is metabolized in the kidney
From the groups of analytes below, which set would most likely be INCREASED in a type 1 diabetic patient in crisis?
Ketone bodies and blood glucose
Which term describes the dose of the drug in which 50% of the individuals will result in mortality?
LD50
Which marker is most useful for detection of gestational trophoblastic disease?
hCG (human chorionic gonadotropin)
Which medication would be prescribed for narcolepsy?
Amphetamine
Which assay is performed to diagnose congestive heart failure (CHF)?
B-type natriuretic peptide (BNP)
Zollinger-Ellison syndrome is characterized by a large (usually 20-fold) elevation of:
Gastrin
Follicle stimulating hormone (FSH) is produced by:
Pituitary
The production of neutral 17-ketosteroids is a measure of which of the following?
Androgen production
Which of the following statements regarding the L/S ratio is TRUE?
A ratio of 2:1 or greater usually indicates adequate pulmonary surfactant to prevent respiratory distress syndrome (RDS)
Which of the following is an example of a specimen which requires a chain-of-custody procedure to be followed?
A urine drug screen for pre-employment
Which of the following medications is known to cause Reye's Syndrome in children?
Acetylsalicylic acid
Which adipokine is decreased in obesity, is anti-inflammatory, and increases insulin sensitivity?
Adiponectin
Which of the following is a true statement about aminoglycoside antibiotics?
Aminoglycosides can be toxic antibiotics that are used to treat bacterial infections when such bacteria are resistant to less-toxic antibiotics. Feedback
Hormonal variation throughout the menstrual cycle typically shows:
An abrupt rise in luteinizing hormone (LH) 3-36 hours prior to ovulation
The immunoassay procedure for serum hCG utilizes antisera against which subunit of hCG?
Beta
Estrogen (ERs) and progesterone (PRs) receptors used as tumor markers are most commonly employed to provide prognostic information about:
Breast cancer
Which enzyme is responsible for the rate-limiting step of steroid hormone synthesis?
CYP450
The parathyroid hormone (PTH) is important in the regulation of:
Calcium and phosphate
Which of the following action describes the MAJOR property of antidiuretic hormone?
Changes distal tubule water permeability
A 64-year old man lost 15 pounds, became weaker, and his face became fuller with a ruddy complexion. His laboratory tests revealed: Serum cortisol8 AM: 880 nmol/L, 138-635 nmol/L (reference range)4 PM: 828 nmol/L, 83-414 nmol/L (reference range) After these results, an overnight dexamethasone suppression test gave a cortisol level of 773 nmol/L. The MOST probable diagnosis for this patient is:
Cushing's Syndrome
Which of the following would you find in a primary hyperparathyroidism case?
Elevated serum calcium and decreased serum phosphorus
In patients with suspected primary hypothyroidism associated with Hashimoto's thyroiditis, one would expect the following laboratory test results:T4 ___? TSH ___? TRH stimulation ___?
Decreased, increased, increased
Thin-layer chromatography is particularly useful as a tool in the identification of:
Drugs
ACTH controls which step of steroid hormone production?
First step (cholesterol esters to cholesterol)
All of the following statements about fluorometry are true, EXCEPT:
Fluorescence is indirectly proportional to the analyte being measured.
Which type of toxicology is primarily concerned with medical and legal consequences of exposure to chemicals and drugs?
Forensic toxicology
An adult's plasma cortisol of 22 µg/dL at 8:00 a.m. and 10 µg/dL at 4:00 p.m. would be:
Found in a healthy individual
Each of the following hypothalamic hormones is correctly matched with the anterior pituitary hormone that it releases EXCEPT:
GHRH --> Oxytocin
Currently the MOST common method for the confirmation of serum barbiturates is:
Gas-liquid chromatography, mass spectrometry
All of the following hormones are produced primarily in the pancreatic islets EXCEPT which one?
Glucagon
Which of the following parts of the body synthesizes and secretes BNP?
Heart
A critically ill 86-year-old female was admitted to the intensive care unit (ICU) after arriving at the emergency department with symptoms that included shortness of breath and fever. Her temperature was 39°C (102°F) and pulse rate 110/minute. A white blood count (WBC) was ordered and was elevated at 15.0 x 109/L. The differential showed an increase in segmented and immature neutrophils. Other testing was ordered after admission to ICU, including a procalcitonin (PCT). The result was 2.15 ng/mL (Reference value for normal at the 95th percentile is <0.05 ng/mL). Given the clinical assessment and laboratory test results, what may the increased procalcitonin indicate?
High risk of severe sepsis/septic shock
Prevent incident light from striking the detector
Hyperparathyroidism
A patient has the following test results: Increased serum phosphorus level, decreased serum calcium level, and decreased serum parathyroid hormone (PTH) level. This patient MOST likely has:
Hypoparathyroidism
Which of the following is considered an action of the hormone glucagon?
Increase glycogenolysis
When a patient is suspected of intoxication, what would you expect the osmol gap to be?
Increased
A major action of angiotensin 2 is
Increased vasoconstriction
Which one of the following adipocyte products is an important messenger in metabolism, signaling the hypothalamus that there are changes in fat stores?
Leptin
Which of the following thyroid function assay results would you expect with hyperthyroidism?
Low TSH, high free T4
Serum calcitonin is typically elevated in which of the following conditions?
Medullary carcinoma of the thyroid
Cushing Syndrome
Metanephrines
You are collecting a blood specimen to be used for forensic (legal) alcohol testing. Which of the following must be done before you can start the specimen collection process?
Must inform the patient that the blood about to be collected is for alcohol testing
When testing for ethanol, what is actually measured in the enzymatic reaction, that is proportional to ethanol concentration?
NADH
Aminoglycosides can cause severe toxicity including which of the following?
Nephrotoxicity and ototoxicity
Enzyme-multiplied immunoassay techniques (EMIT) differ from all other types of enzyme immunoassays in that
No separation of bound and free antigen is required
Can you use an alcohol wipe to cleanse the venipuncture site prior to obtaining a sample for ethanol?
No, alcohol wipes must be avoided when testing for ethanol levels
Which three hormones are known to regulate serum Ca2+ by changing their secretion rate in response to changes in ionized Ca2+?
PTH, vitamin D & calcitonin
The following BEST describes serum hCG levels during pregnancy:
Rapid rise in levels during first trimester; slow decline and possible level-off throughout remainder of pregnancy
All of the following are characteristics of type 2 diabetes mellitus EXCEPT:
Requires insulin therapy to control hyperglycemia.
What is the purpose of the BNP test?
Rules out acute heart failure in the emergency setting.
Patients with Cushing's disease typically exhibit:
Serum cortisol overproduction
Which one of the following statements about lead poisoning is false?
Serum lead level is a good inexpensive screening test for lead toxicity
Which of the following describes gastrin's role in digestion?
Stimulates gastric acid-HCl secretion
Which of the following immunosuppressive drugs below has been associated with thrombus formation in patients with toxic levels?
Tacrolimus
The principal amount of testosterone in males is produced by which endocrine gland?
Testes
Which of the following factors would least affect an orally-administered drug's absorption and/or distribution in the body?
The position of the patient when the drug is taken (sitting vs. standing)
When collecting a urine specimen for workplace drug testing, which of the following situations may indicate that the specimen has been tampered with or adulterated?
The specific gravity test result is 1.001
Serum TSH levels five-times the upper limit of normal in the presence of a low T4 and low T3 uptake could mean which of the following:
The thyroid has been established as the cause of hypothyroidism
A mother and young child arrive at the outpatient laboratory with a physician's order for a lead test on the child. The phlebotomist decides to perform a dermal puncture (fingerstick). What procedure is important to implement when a test for lead is collected by finger puncture that would NOT be necessary prior to an antecubital venipuncture?
Thoroughly washing patient's hands with soap and water
In healthy individuals, calcitonin is synthesized by which cells in the body?
Thyroid C cells
Circulating organic iodine is found primarily in the form of:
Thyroxine