Liver Function Tests & Detoxification (Viva)

Liver Function Tests


Q.1 What are the various liver function tests commonly performed?

  1. Serum total proteins, A/G ratio.
  2. Prothrombin time.
  3. Serum cholesterol.
  4. Serum bilirubin.
  5. SGOT.
  6. SGPT.
  7. S.alkaline phosphatase.

Q.2 What is the importance of liver function tests?

  1. To assess the severity of liver damage.
  2. To differentiate different types of jaundice.
  3. To find out the presence of latent liver disease.

 Q.3 What is the normal serum protein level?

6-8 gm%

Q.4 What is the level of albumin and globulin?

Albumin 4.0-5.5 gm%

Globulin 1.5-3.0 gm%

Q.5 What is the normal A/G ratio?

 1.2: 1

Q.6 What are the conditions in which total proteins are low?

  1. Malnutrition.
  2. Liver disease.
  3. Nephrotic syndrome.

Q.7 Where is albumin synthesized?

Liver

Q.8 What happens to the A/G ratio, if the liver is damaged?

If the liver is damaged, albumin synthesis is decreased and hence A/G ratio lowers down.

Q.9 If total proteins are low, what happens to the A/G ratio.

 A/G ratio lower decreases.

Q.10 How will you separate albumin and globulin?

  1. By precipitation reactions using 28% sodium sulphite.
  2. By electrophoresis.

Q.11 In the case of nephrotic syndrome, what will be the abnormality in the urine sample?

 Urine will show the presence of albumin

Q.12 Why albumin comes in the urine first?

Albumin is low molecular weight and smaller in size as compared to globulin and hence it is filtered by the glomeruli first.


Q.13 How is albumin detected in urine?

  1. By heat coagulation test.
  2. By Heller’s test.

Q.14 What are the functions of plasma proteins?

  1. In maintaining osmotic pressure.
  2. As buffers.
  3. As carrier of various metabolites.
  4. Antibodies.

Q.15 What are the various fractions of plasma protein separated by electrophoresis?

 Albumin.
α1-globulin.
α2-globulin
β-globulin
γ-globulin
Fibrinogen

Q.16 What is the normal serum cholesterol level?

150-250 mg%

Q.17 What is the percentage of esterified and non-esterified form of cholesterol?

Nonesterified form 30%

Esterified form 70%

Q.18 What are the conditions in which cholesterol level in the blood is increased?

  1. Diabetes mellitus.
  2. Atherosclerosis.
  3. Hypothyroidism.
  4. Obstructive jaundice.
  5. Nephrotic syndrome.
  6. Myxoedema.
  7. Xanthomatosis.

Q.19 What are the conditions in which cholesterol level in the blood is decreased?

  1. Hyperthyroidism.
  2. Pernicious anemia.
  3. Hemolytic jaundice.
  4. Malabsorption syndrome.

Q.20 By which method cholesterol is estimated.

Cholesterol is estimated colorimetrically by Lieberman Burchardt reaction.

Q.21 What are the foods rich in cholesterol?

Egg yolk, liver, brain, etc.

Q.22 What is the site of cholesterol synthesis?

Liver, adrenal cortex, skin, intestine, testes, aorta, etc.

Q.23 What is the starting material for cholesterol synthesis?

Acetyl CoA

Q.24 What are the steps in cholesterol synthesis?

Acetyl CoA → Acetoacetyl CoA → HMG CoA → Mevalonate → Squalene → Cholesterol.

Q.25 How cholesterol biosynthesis is regulated?

Cholesterol biosynthesis is regulated by a negative feedback mechanism. The rate-limiting enzyme is HMG-CoA reductase. Dietary cholesterol inhibits the biosynthesis of cholesterol in the liver by depressing the synthesis of HMG-CoA reductase in the liver. Whereas fasting inhibits cholesterol biosynthesis by diverting HMG-CoA to ketone bodies formation. While high-fat diet accelerate the cholesterol production.

Q.26 What are the metabolic products of cholesterol breakdown?

  1. Bile acids.
  2. Steroid hormones.
  3. Fecal steroids (Coprostanol and cholesterol).

Q.27 What does SGOT/SGPT stands for?

  • SGOT stands for serum glutamate oxaloacetate transaminase.
  • SGPT stands for serum glutamate pyruvate transaminase.

Q.28 What is atherosclerosis?

Deposition of cholesterol and cholesterol esters in the arterial walls leads to a condition known as atherosclerosis.

Q.29 What is the normal serum bilirubin level?

 0.2-0.8 mg%

Q.30 Name the reaction by which bilirubin in estimated colorimetrically.

van den Bergh reaction.

Q.31 What is thymol turbidity test?

When thymol barbitone is added in serum: a. Faint opalescent color when g globulin is normal, i.e. in prehepatic and posthepatic jaundice. b. Turbid solution when g globin level increases, i.e. in hepatic jaundice.

Q.32 Give the results of von den Bergh test in different jaundice.

Pre hepatic → Indirect +ve
Hepatic → Biphasic
Posthepatic → Direct +ve

 

Q.33 What is direct bilirubin?

 Bilirubin diglucuronide is called direct bilirubin. It is water-soluble.

Q.34 What is the indirect bilirubin?

Albumin bound bilirubin is called indirect bilirubin. It is water-insoluble.

Q.35 How bilirubin is formed?

Bilirubin is formed as a breakdown product of hemoglobin.

Q.36 What is jaundice?

Jaundice is due to the accumulation of bile pigments (i.e, bilirubin and biliverdin) in the blood giving rise to increased level of these in blood which imparts yellow color in the eyes and the skin.

Q.37 When does bilirubin appear in urine?

Bilirubin appears in urine in obstructive jaundice.

Q.38 What does the presence of bilirubin in urine suggests?

The presence of bilirubin in urine suggests the increased level of direct bilirubin (water-soluble) in the blood.

Q.39 What is obstructive jaundice?

Obstructive jaundice is due to the obstruction or blockage of the bile duct.

Q.40 What is hemolytic jaundice?

Hemolytic jaundice is due to an increased rate of break down of red cells (hemolysis) leading to an increased rate of bile pigment formation at a rate exceeding the capacity of the liver to remove the pigment.

Q.41 What is hepatocellular jaundice?

This type of jaundice is due to the impaired capacity of the liver to conjugate bilirubin and secrete the conjugate into the bile.

Q.42 Name some enzymes whose levels are elevated in liver disease.

  1. Serum alkaline phosphatase.
  2. SGPT.

Q.43 Name the bile pigments.

Bilirubin, biliverdin.

Q.44 What is prothrombin time?

Prothrombin time is the time required for clotting citrated plasma to which optimum amounts of thromboplastin and calcium has been added.

Q.45 What is the normal value of prothrombin time?

14-17 seconds

Q.46 What are the conditions in which prothrombin time is affected?

  1. In liver damage.
  2. In obstructive jaundice

Q.47 What is the vitamin required in the formation of prothrombin?

Vitamin K

Q.48 What is the harm of increased prothrombin time?

Increased prothrombin time signifies a low level of prothrombin, which means blood will take more to clot, and hence the loss of blood will be more.

Q.49 What is neonatal jaundice?

During the first 10 days of life, a child usually develops jaundice called physiological or neonatal jaundice.

Q.50 What is the reason for developing neonatal jaundice?

  1. Excessive destruction of RBC.
  2. Hepatic immaturity.

Q.51 What is the treatment of neonatal jaundice?

Phototherapy

Q.52 Give the procedure of phototherapy?

Skin is illuminated with white light. So that albumin is converted into bilirubin which has a shorter life span.



Detoxification


Q.1 What is detoxification?

Detoxification is a biochemical changes taking place in the body whereby foreign molecules (toxic) are converted to harmless compounds which are more readily excretable.

Q.2. What are xenobiotics?

Xenobiotics refer to all foreign pollutants, food additives, chemicals, drugs, carcinogens, etc.

Q.3. What are the major phases involved in detoxification?

Phase I. hydroxylation (mainly)

Phase II. conjugation

Q.4. What are the various processes involved in detoxification?

  1. Oxidation
  2. Reduction
  3. Hydrolysis
  4. Conjugation

Q.5. What is responsible for hydroxylation?

Cytochrome P450.

Q.6. What is the chemical nature of cytochrome P450?

Cytochrome P450 is hemoproteins.

Q.7. What are the main sites of detoxification?

 Liver—main seat of detoxification.

Kidney and other organs also participate to some extend.

Q.8. Give examples of detoxifications?

Oxidation:
i. Methyl alcohol → Formic acid
ii. Indole → Indoxyl
Reduction:
i. Picric acid → Picramic acid
ii. p-Nitrobenzene → p-Nitrophenol
Hydrolysis:
i. Phenylacetic acid → Phenol
ii. Aromatic amides → Corresponding acids.
Conjugation
i. Glycine + benzoic acid → Hippuric acid
ii. Bilirubin + glucuronic acid → Bilirubin diglucuronide.

 

Q.9. What factors influence xenobiotics metabolizing enzymes?

  1. Age.
  2. Sex.
  3. Some genetic factors

Q.10. What is hydroxylation?

 It is any chemical process that introduces one or more hydroxyl groups (–OH) into a compound thereby oxidizing it.

Q.11. What is oxidation?

It is described as the loss of an electron by a molecule or atom.

Q.12. Describe reduction.

It is described as the uptake of an electron by a molecule or atom.