Chemistry rotation MediaLab

What would the following Schilling test results indicate: Part I: 2% excretion of radioactive vitamin B12 (normal 5-35%) Part II: 8% excretion of radioactive vitamin B12 after intrinsic factor was given with B12 (normal 7-10%)

Pernicious anemia

Which of these drugs is listed as an anti-convulsant? Lithium Gentamicin Tacrolimus Phenobarbitol

Phenobarbitol (Tacrolimus is an immunosuppressive drug)

Which condition is suggested by a jaundiced patient with a marked rise in alkaline phosphatase (ALP) and conjugated bilirubin, and a slight rise in alanine aminotransferase (ALT)?

Post-hepatic cholestasis

Which usually shows a DECREASE during an acute phase reaction? Albumin Alpha-1 Antitrypsin Fibrinogen Ceruloplasmin

Albumin (others increase)

The measurement of total glycosylated hemoglobin A1c is an effective means of assessing the average blood glucose levels:

Over the past 2-3 months

Pheochromocytoma is a tumor of the adrenal medulla that results in elevated urinary levels of all these EXCEPT: Cortisol Free catecholamines Metanephrines Vanillylmandelic acid

Cortisol

Which of these analytes would be increased due to delay in centrifugation? Creatinine Ionized calcium Folate Bicarbonate

Creatinine (released over time by cells. Gluc, Ion.Ca, bicarb, folate decr bc cellular consumption)

Which nitrogen base would bind with a guanine nucleotide in forming double-stranded DNA?

Cytosine

The lecithin to sphingomyelin ratio (L/S) is used to assess:

Fetal lung maturity

Each of these hypothalamic hormones is correctly matched with the anterior pituitary hormone that it releases EXCEPT: TRH : TSH GnRH : LH and FSH CRH : ACTH GHRH : Oxytocin

GHRH : Oxytocin (GHRH : Growth Hormone; Oxytocin not pituitary)

All of these hormones are produced primarily in the pancreatic islets EXCEPT: Gastrin Glucagon Insulin Pancreatic polypeptide

Gastrin

Which is true of genotype screening in pharmacogenomics? Genotype screening gives a better overall picture of drug metabolism than measuring metabolism with probe drugs. Genotyping does not take into account drug interactions which can affect metabolism. Genotyping typically involves measuring only one mutation site or polymorphism. Genotyping has no known impact on drug metabolism.

Genotyping does not take into account drug interactions which can affect metabolism.

Hydrogen ion concentration (pH) in blood is usually determined by means of which electrode?

Glass

Which enzyme is responsible for the conjugation of bilirubin?

Glucuronyl transferase

The most likely cause of elevated serum potassium levels in an apparently normal individual is:

Hemolysis

A critically ill 86yo female is admitted to the ICU with symptoms incl. shortness of breat and fever. Temp 39 (102F), pulse 110/min. WBC elevated, incr. segs and immature neutrophils. Procalcitonin (PCT) was ordered: result 2.15 ng/mL (normal <0.05 ng/mL). What may the increased PCT indicate?

High risk of severe sepsis / septic shock

A 46yo woman was admitted through the ER with severe diarrhea, headaches, muscle aches, shortness of breath, and increased heart rate. Blood gas results: pH = 7.30 pCO2 = 32 mm Hg HCO3- = 15 mmol/L pO2 = 93 mmol/L What acid base disorder is most consistent with these results and symptoms?

Metabolic acidosis (pH ref: 7.35-7.45; pCO2: 35-45; HCO3-: 22-29; pO2: 85-105)

All of these are true regarding the hepatic system and drug metabolism EXCEPT: Changes in hepatic status will affect the concentration of circulating drugs eliminated. Hepatic disease states characterized by a loss of functional tissue may result in slower rates of clearance. Hepatic disease states characterized by a loss of functional tissue may result in a longer drug half-life. Metabolism of acetaminophen by the MFO system is altered by alcohol and makes it less toxic.

Metabolism of acetaminophen by the MFO system is altered by alcohol and makes it less toxic. (It makes it MORE toxic)

This serum protein electrophoresis (SPE) scan most likely represents which of the following disease states? (low, slightly tailing up to a spike around the middle of the chart, quick dropoff, very tiny bump, spike near the end) Chronic inflammation Myocardial infarction Liver disease Multiple myeloma

Multiple myeloma (tall narrow peak in the beta region with decreased normal Igs in the gamma region)

Creatinine excretion correlates best with which parameter? Age Sex Muscle mass Body weight

Muscle mass

Enzyme-multiplied immunoassay techniques (EMIT) differ from all other types of enzyme immunoassays in that:

No separation of bound and free antigen is required (enzyme-labelled drug binds to remaining available sites)

The American Diabetes Association recommends performing routine oral glucose tolerance test (OGTT):

OGTT is discouraged for routine use

In therapeutic drug monitoring, a person classified as an ultrarapid metabolizer (UM) would need _____ of a drug metabolized by that enzyme. A lower dose A higher dose The standard dose There's no such thing as an ultrarapid metabolizer.

A higher dose (you want the drug to stay in the system before it's metabolized)

All of these are characteristic of the role of C-reactive protein (CRP) EXCEPT: Activates complement Binds with factor H to initiate alternative complement pathway Exhibits pro-inflammatory characteristics Initiates opsonization

Binds with factor H to initiate alternate complement pathway

Which is true of C-reactive protein (CRP) when being used to assess the risk of cardiovascular disease? CRP levels are high in cardiovascular disease. CRP levels are not affected by cardiovascular disease. CRP levels are low in cardiovascular disease. CRP has little clinical utility for assessing cardiovascular disease.

CRP levels are high in cardiovascular disease.

Which is considered a cause of hypomagnesemia (decreased levels of magnesium in the blood)? Hypothyroidism Hypoaldosteronism Pancreatitis Bone carcinoma

Pancreatitis (decr. absorption of Mg; others cause incr Mg)

What transferrin saturation level would be indicative to investigate further for hereditary hemochromatosis (HH)?

45%

What percentage of dietary iron is normally absorbed daily?

5 to 15%

Which assay is performed to diagnose congestive heart failure (CHF)?

B-type natriuretic peptide (BNP)

Which of these GFR (glomerular filtration rate) values is considered to be in renal failure? 120 mL/min 95 mL/min 35 mL/min 14 mL/min

14 mL/min (normal >90, 15-60 = kidney damage)

Which are markers currently used to differentiate heart failure from lung disease? TnI and TnT BNP and NT-proBNP Myoglobin and LD hs-CRP and homocysteine

BNP and NT-proBNP

What is a hemiacetyl?

A compound with both a carbonyl and alcohol group

Which of these 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). A ratio of 5:1 indicates fetal lung maturity in diabetic pregnancies. Sphingomyelin levels increase in the 3rd trimester, causing the L/S ratio to fall during the last two weeks of gestation. A phosphatidylglycerol (PG) spot indicates meconium in the amniotic fluid.

A ratio of 2:1 or greater usually indicates adequate pulmonary surfactant to prevent respiratory distress syndrome (RDS).

All of these are components of a basic single beam spectrophotometer EXCEPT: Beam splitter Cuvette Prism Light source

Beam splitter (part of a dual beam spectrophotometer)

Which of these tests is the BEST screening test for neural tube defects? Placental lactogen Bilirubin Estriol Alpha-fetoprotein

Alpha-fetoprotein (produced by the fetal liver: high assoc. with defects in the neural tube; low assoc. with Down's syndrome)

All of these lab tests are used to determine kidney function EXCEPT: Creatinine Blood urea nitrogen (BUN) Amylase Phosphorus

Amylase (pancreas)

Given the following data, what is the most likely disease state? Total bili = 4.0 (0.5-1.5) Direct bili = 3.0 (0.2 - 0.5) AST = 75 (2-25) ALT = 118 (2-23) LD = 220 (<140) ALP = 841 (28-68) GGT = 150 (21-40 U)

Biliary duct obstruction (incr. in both ALP and GGT, specific for biliary tree issues, plus conj. bili. Intoxication: no incr. bili. Hemolytic disease: incr. unconj bili and LD. Bone disease: incr. ALP but not GGT or other liver enz)

Following a myocardial infarction, which of these enzymes will be the first to become elevated? CK LDH GGT ALT

CK (myoglobin>CK>LDH; not GGT or ALT - liver)

Which of these cardiac biomarkers could detect a recent reinfarction? Troponin I (TnI) Troponin T (TnT) Lactate dehydrogenase (LD / LDH) Creatine kinase MB (CK-MB)

CK-MB

All these statements concerning CK-MB (CK-2) are true EXCEPT: Greater than 5% or 10 IU/L followed by an LDH-1:LDH-2 flip is specific evidence of myocardial infarction (MD). CK-MB levels can be normal with an elevated total CK. CK-MB and troponin levels can be elevated after an AMI. CK-MB levels are normal in cardiac ischemia.

CK-MB levels are normal in cardiac ischemia (they're not)

Which is the most common technique used by clinical labs for therapeutic drug monitoring?

Immunoassay

A 56yo female was taken to the ER in a coma. She had lost 35 pounds in 3 months, was always thirsty, drinking lots of water and running to the bathroom. Lab results: pH: 7.11 (7.35-7.45) pCO2: 21 mm Hg (35-45) Glucose: 950 mg/dL (60-110) Serum osmolality: 365 mOsm/Kg (275-295) Urine ketones: strongly positive Urine glucose: strongly positive What is the MOST likely cause of these symptoms?

Insulin dependent diabetes mellitus

The migration rate of proteins on cellulose acetate is primarily the result of:

Ionic charge on the proteins

Albuterol is a fast-acting bronchodilator used acutely during asthma attacks. All these reasons explain why therapeutic drug monitoring is not available or common EXCEPT: It is not chronically used, so toxicity is less likely. The half-life is short and the drug is cleared quickly. It has a wide therapeutic window. It has a narrow therapeutic window.

It has a narrow therapeutic window.

Which term describes the dose of the drug in which 50% of the individuals will result in mortality? ED50 LD50 TD50 MD50

LD50 (Lethal dose 50; others are Effective Dose, Toxic Dose, MD is meaningless)

All of these analytes would be significantly increased in a plasma sample as a result of hemolysis, EXCEPT: Potassium LDH Sodium AST

Sodium (Potassium, LDH, AST all found in higher concentration in RBCs than in plasma)

Which of the following conditions would argue in favor of therapeutic drug monitoring (TDM) for a given drug? The drug has a low degree of protein binding. The drug is given chronically. The drug has low toxicity and few side effects. The effective and toxic concentrations are not well defined.

The drug is given chronically.

When collecting a urine specimen for workplace drug testing, which of these situations may indicate that the specimen has been tampered with or adulterated? The temperature is 34 degrees C. The specific gravity is 1.001. The color is amber. The specific gravity is 1.020.

The specific gravity is 1.001 (<1.003 indicates dilution with water)

What is the MOST specific biochemical marker for myocardial infarction?

Troponin

The term pharmacokinetics BEST describes:

What the body does to the drug