Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

CC1 > Lec 17: Liver Function Tests > Flashcards

Lec 17: Liver Function Tests Flashcards

1
Q

5 Tests that are no longer used and are deemed obsolete.

A
  • Hippuric test
  • Urobilinogen quantitation in urine & stool
  • Gross test
  • Cephalic flocculation test
  • Colloidal gold test
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Define:

  1. exogenous compounds
  2. endogenous compounds
  3. Iodine staining dyes
A

Exogenous Compounds
Coming from outside the body which should be administered.
• aminopyrine, caffein

Endogenous Compounds
Not routinely used, for research purposes.
• bile acids

Iodine Staining Dyes
Widely used for radiographic and other imaging procedures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How many lab tests do liver profiles usually have?

A

4 to 8

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What substances are tested for the following:

  1. Special Chemistry tests
  2. Immunologic test
  3. Hematologic test
A

Special Chemistry tests
• Ceruloplasmin
• Alpha-fetoprotein
• Serum Iron & ferritin
• Serum bile acids
• Ammonia

Immunologic test
• IgM & IgG antibodies to Hep A
• IgM & IgG antibodies to Hep D
• Antibodies to Hep C virus
• Antibodies to HbSAg
• Antimicrobial antibodies

Hematologic test
• CBC
• Determination of abnormal Hgb types
• Coagulation factor studies
• Reticulocyte count
• Red cell enzyme studies
• Prothrombin time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Classifications of Tests and their example

A

Abnormalities of pigment metabolism
• serum bilirubin & VD Bergh reaction
• Icteric index
• urine bilirubin
• urine & fecal Urobilinogen
• serum & urinary bile acids

Changes in plasma proteins
• estimation of Total plasma proteins, albumin, globulin, A/G ratio
• plasma fibrinogen
• Various flocculation tests
• amino acids in urine

Carbohydrate metabolism
• Galactose tolerance test
• Fructose Tolerance test

Lipid abnormalities
• Cholesterol and cholesterol ester and ratio
• determination of fecal fats

Detoxicating function of liver
• hippuric acid synthesis test
• Amino antipyrine breath test

Excretory function of liver
• Bromsulphalein test
• 131I Rose Bengal test

Prothrombin by liver
• prothrombin time

Amino acid catabolism
• Blood NH3
• CSF glutamine

Serum enzyme activities

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Serum Bilirubin

  1. Uses of bilirubin determination.
  2. In average plasma conc, give the concentrations of TB, Unconjugated and conjugated bilirubin.
A
  1. a. To detect the breakdown of hemoglobin (hemolysis)
    b. To detect decrease in excretion by the liver due to obstruction
  2. Average plasma conc
    Total bilirubin: less than 1 mg/dL
    Unconjugated B: less than 0.8 mg/dL
    Conjugated B: less than 0.2 mg/dL
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Forms of Bilirubin

• contains 1 to 2 attached glucuronic acid molecules
• reacts readily with Aqueous solution (give example)
• found in small amounts in urine

A

Conjugated Bilirubin
• Aqueous sol: diazotized sulfanilic acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Forms of Bilirubin

• reacts slowly unless with addition of solubilizing agent
• NOT excreted in urine

A

Unconjugated Bilirubin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Forms of Bilirubin

• seen only in the presence of significant hepatic obstruction
• conjugated that is covalent bound to albumin

A

Delta Bilirubin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

The concentration of conjugated/unconjugated in total bilirubin based on the type of hyperbilirubinemia:

  • conjugated hyperbilirubinemia
  • unconjugated hyperbilirubinemia
A

Conjugated Hyperbilirubinemia
50% of Total bilirubin is conjugated

Unconjugated Hyperbilirubinemia
80% of Total bilirubin is unconjugated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Diazotization Principle

  1. Product (name & color)
  2. Accelerator used in Evelyn & Malloy in 1937
  3. Accelerator used in Jendrassik & Grof in 1938
A
  1. (Di)Azobilirubin (purple)
  2. 50% Methanol
  3. Caffeine-benzoate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Oxidation Principle

  1. Bilirubin is converted into what derivative? (Name & color)
  2. Bilirubin behaves like an indicator. Give the color of the pH.
A
  1. Biliverdin (green)
  2. a. Acidic: pink-purple
    b. Alkaline: blue
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

EVELYN & MALLOY

  1. Principle
  2. Reaction time
  3. Product (name & color)
  4. Methanol is added for what form of bilirubin?
  5. Formula for getting Indirect Bilirubin
A
  1. Bilirubin reacts with diazotized sulfanilic acid to form a purple azobilirubin
  2. 1 to 5 minutes
  3. Purple azobilirubin
  4. Indirect bilirubin
  5. Indirect bilirubin = TB - Direct bilirubin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

VAN DEN BERGH

  1. Principle
  2. Product (name & color)
  3. Components of Diazo reagent
  4. Formula for Direct bilirubin
  5. Formula for TB
A
  1. Bilirubin reacts with Van Den Berg’s diazo reagent to form a purple azo bilirubin
  2. Purple azobilirubin
  3. 10mL of Sol. A
    • Sulfanilic acid in conc. HCl
    0.8mL of Sol. B
    • Sodium Nitrite in water
  4. Direct bilirubin = (Test – BLK) ÷ 2
  5. TB = Test – BLK
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Purpose of Methanol

A
  • a dissociating agent
  • catalyst
  • solubilizing agent
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Factors affecting Bilirubin Determination: SAMPLE STABILITY

  1. How is bilirubin affected by light?
  2. Samples should be placed in ___ glassware or be wrapped in ___.
  3. Storage of samples and their stability.
A
  1. When exposed to light, Bilirubin becomes Biliverdin by photo-oxidation/dehydrogenation.
    • bilirubin conc. is reduced:
    —> 10% in 30 minutes
    —> 50% in 1 hour
  2. a. Low actinic glassware
    b. carbon paper
  3. a. 2 days — dark at RT
    b. 1 week — dark refrigerator
    c. 3 months — freezer
17
Q

Factors affecting Bilirubin Determination: HGB & LIPEMIA INTERFERENCE

  1. How does hemolysis affect bilirubin?
  2. How does Lipemia affect bilirubin?
  3. How much Hemoglobin can cause direct bilirubin to be low by 10, 15, and 45%?
  4. This hemoglobin oxidizes bilirubin, and is eliminated by saturation of CO and Ascorbic acid.
A
  1. Hemolysis decreases the reaction of bilirubin with diazo reagent producing false low concentrations
  2. Lipemia causes error in the spectrophotometric measurements
  3. 100, 250, 1000 hgb/100mL
  4. Oxyhemoglobin
18
Q

Factors affecting Bilirubin Determination: TEMPERATURE

  1. Reaction in the presence of methanol is faster at ___ than at 25°C.
  2. Temperature affects the rate of ___.
A
  1. 37°C
  2. Color development
19
Q

Factors affecting Bilirubin Determination: STANDARDIZATION

  1. Effect of Impurities in commercial preparations of bilirubin.
  2. Effect of incomplete solubility
  3. Effect of instability
  4. What substance is used to stabilize bilirubin? For how long?
  5. This substance only makes the sample stable for 3 minutes?
A
  1. Most commercial preparations of bilirubin are not pure, so impurities can affect the accuracy and consistency of the results.
  2. Commercial bilirubin tend to have incomplete solubility, so it can lead to difficulties in preparing standardized solutions.
  3. Instability can change the concentration.
  4. a. 20mg/100mg of Chloroform
    b. 3 months
  5. Ethyl acetate methanol
20
Q

Define/describe:

  1. Immediate direct reaction
  2. delayed direct response
  3. no direct reaction is obtained
A

Immediate direct reaction
Immediate color development

Delayed direct response
Color development after 5-30 minutes

NO direct reaction is obtained
Color development after addition of methanol

21
Q

Components of Artificial STD used in Indirect Reaction.

A

Methyl red solution in GAA of pH 4.6–4.7
• closely resembling azobilirubin’s color

CC1 (16 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions