Monday, October 22, 2012

Subjective Questions- Haem synthesis and degradation


Q.1- Describe the fate of the hemoglobin molecules when senescent erythrocytes are broken down in the reticuloendothelial system. Explain what is meant by pre-hepatic, hepatic and post-hepatic jaundice. Give causes, laboratory findings and treatment of each of the above conditions.

Q.2- Explain the biochemical basis of Porphyria. Classify and  discuss two clinical condition in which different metabolites of porphyrins accumulate  to cause cutaneous hypersensitivity.

Q.3- What is the cause of neonatal jaundice? Explain the basis of blue light phototherapy of this condition.

Q.4- Explain how biliary obstruction could impair blood coagulation.

Q.5-Discuss the different clinical states of hyperbilirubinemia (congenital or acquired) caused due to impaired activity of UDP Glucuronyl transferase enzyme.

Q.6- Describe the biochemical basis and outline the laboratory tests for (a) obstructive jaundice; (b) acute intermittent Porphyria.

Q.7-(a) Explain the principle of measurement of total and free bilirubin by the van den Bergh reaction (b) Explain the diagnostic value in determining serum bilirubin.

Q.8- Explain how lead poisoning affects haem synthesis.

Q.9- From your knowledge of porphyrin metabolism, explain the justification for the current introduction of unleaded petrol.

Q.10- How is the biosynthesis of haem normally regulated?

Q.11- Explain why measurements of both bilirubin and urobilin are relevant to the diagnosis of obstructive jaundice?

Q.12- In a person with a defect in bilirubin metabolism, what can you deduce from the following laboratory results: (a) Bilirubin in urine and decreased urinary urobilinogen. (b) Absence of bilirubin in urine and increased urinary urobilinogen.

Q.13- In patients with a deficiency of coproporphyrinogen oxidase, what abnormalities in porphyrin metabolites would you expect to see?

Q.14- A rational approach to the diagnosis and treatment of jaundice rests on a good knowledge of the biochemistry of bilirubin metabolism. Discuss.

Q.15- What do you understand by the terms “direct” and “indirect”" Van Den Bergh reactions?

Q.16- Discuss briefly the diagnostic value of measuring stercobilin and or urobilin.

Q.17- Explain the use of biochemical tests to confirm the diagnosis of hepatocellular jaundice.

Q.18- Give the reactions catalysed by (a) haem oxygenase (b) ALA synthase (c) Ferrochelatase

Q.19- What is the biochemical basis of cutaneous hypersensitivity in Congenital Erythropoetic Porphyria?

Q.20- What is the biochemical basis of giving Hematin or Glucose infusion to treat acute attack of Porphyria?

Q.21- Discuss the basis of breast milk jaundice.

------------------------------------------ Best Wishes: Dr.Ehab Aboueladab, Tel:01007834123 Email:ehab10f@gmail.com,ehababoueladab@yahoo.com ------------------------------------------

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