Clinical Chemistry II, Quiz 19.

In the Jendrassik-Grof method for the determination of serum bilirubin concentration, quantitation is obtained by measuring the color of

azobilirubin

Board Review Question: The most widely used methods for bilirubin measurement are those based on the

Jendrassik-Grof method

Board Review Question: Bile acid concentrations are useful to assess

hepatobiliary disease

Board Review Question: The greatest activities of serum AST and ALT are seen in

acute hepatitis

Board Review Question: A 48-yr old woman with mild jaundice has the following serum enzyme results

ALP 600IU/L (ref:0-150IU/L)

GGT 230IU/L (ref:0-55IU/L)

ALP after 10minutes' incubation at 56C 300IU/L (ref: 50% of original activity)

AST 400 IU/L (ref: 0-50 IU/L)

Which of the following sources most contributes to the patient's ALP activity?

liver

What is portal circulation?

network of veins that carry blood from the intestines to the liver

Which of the following is not a function of the liver?

Synthesis of hemoglobin

What is/are the function(s) of the liver?

all of the above

The portal vein drains the detoxified blood away from the liver.

false

The liver produces cholesterol.

true

In the small intestines, bilirubin is reduced to what colorless substance?

Urobilinogen

When elevated amounts of bilirubin are presented to the liver with elevated serum unconjugated bilirubin, what type of jaundice occurs?

prehepatic

What reagents are used in the Jendrassik-Grof method for bilirubin determination?

Sulfanilic acid; sodium nitrite

What is the preferred specimen to measure serum bilirubin levels in newborns?

A brown collection container to protect specimen from light

What is the function of caffeine-benzoate in the bilirubin assay?

Solubilize indirect bilirubin

The following results were obtained on a grossly icteric serum sample. What is the next step?

Total bilirubin 15.8 mg/dL

Direct bilirubin 18.6 mg/dL

Repeat patient testing

The laboratory results from a jaundiced patient correlate with which of the following diseases?

Total bilirubin 8.5 mg/dL

Direct bilirubin 6.1 mg/dL

AST 1000 U/L

ALT 1250 U/L

ALP 300 U/L

Acute viral hepatitis

What is unconjugated bilirubin?

Bilirubin bound to glucuronic acid

What enzyme conjugates bilirubin in the hepatocyte?

UDP-glucuronyl transferase

What reagent is used in the bilirubin method to shift the color reaction to a wavelength with less interference?

Alkaline tartrate

Which of the following is false regarding bilirubin metabolism?

Unconjugated bilirubin is insoluble and must be bound to albumin for circulation.

Which of the following would be classified as prehepatic jaundice?

Congestive heart failure

The enzyme system that catalyzes the conjugation of bilirubin is known as:

Uridine diphosphate (UDP) glucoronyl transferase.

In obstructive liver disease, the following test results are found:

Feces: urobilinogen decreased; urine: bilirubin: positive; serum: conjugated bilirubin increased.

These cells are phagocytes that engulf bacteria, old RBCs, toxins and cellular debris

Kupffer cells

Board Review Question: To ensure an accurate ammonia level result, the specimen should be

spun, separated, iced, and tested immediately

Board Review Question: Given the following results:

ALP: slight increase

ALT: marked increase

AST: marked increase

GGT: slight increase

This is most consistent with :

acute hepatitis

Board Review Question: In the liver, bilirubin is converted to

bilirubin diglucuronide

Bile formed in the liver is stored in the:

gall bladder.

If a total bilirubin is 4.0 mg/dL and the conjugated bilirubin is 2.5 mg/dL, the unconjugated bilirubin is:

1.5 mg/dL.

Alcoholic liver disease that follows six months to a year of moderate consumption, few lab abnormalities, and is reversible with abstinence from alcohol is termed:

alcohol fatty liver disease.

In the liver lobule, each portal triad is made of a branch of:

hepatic artery, portal vein, bile duct

Board Review Question: Serial bilirubin determination are charted below with the best explanation for the results due to

Day 1, collected at 7 am, assayed at 8 am, result: 14.0 mg/dL

Day 2, collected at 7 am, assayed at 6 pm, result: 9.0 mg/dL

Day 3, collected at 6 am, assayed at 8 am, result: 15.0 mg/dL

sample exposure to light

Board Review Question: Which two conditions can "physiologically" elevate serum alkaline phosphatase?

growth, third-trimester pregnancy

Board Review Question: The most sensitive enzymatic indicator for liver damage from ethanol intake is

gamma-glutamyl-transferase (GGT)