NADPH is a product of the hexose monophosphate pathway (HMP) in the red blood cell. The NADPH is used for the

Correct Answer: B

Rationale: The correct answer is B: Reduction of glutathione. In the HMP pathway, glucose-6-phosphate is converted to ribulose-5-phosphate, generating NADPH. NADPH is essential for the reduction of glutathione, which helps in detoxifying reactive oxygen species and protecting red blood cells from oxidative damage. Fatty acid synthesis (choice A) primarily requires NADPH from the pentose phosphate pathway. ATP formation (choice C) is not a direct function of NADPH production in the HMP pathway. NADPH is not directly involved in the removal of oxygen radicals (choice D), as it is the reduced form of NADP+ that participates in antioxidant defense mechanisms.

Correct Answer: B

Rationale: The correct answer is B: Absolute lymphocytes. In CLL, the most important diagnostic criteria is an absolute lymphocyte count greater than 5,000/microliter. This is crucial for distinguishing CLL from other lymphoproliferative disorders. The presence of hypogammaglobulinemia (choice A) is not specific to CLL and can be seen in other conditions. Male predominance (choice C) is an epidemiological feature and not a diagnostic criterion. Enlarged lymph nodes (choice D) are a common clinical finding but do not solely confirm the diagnosis of CLL.

Correct Answer: D

Rationale: The correct answer is D because heparin binds to antithrombin III, enhancing its ability to inactivate thrombin. This prevents the conversion of fibrinogen to fibrin, thereby inhibiting blood clot formation. Choices A and B are incorrect because heparin does not affect vitamin K-dependent clotting factors or platelet activation. Choice C is incorrect because heparin does not directly prevent platelet aggregation.

Correct Answer: D

Rationale: The correct answer is D, as the Philadelphia chromosome is typically found in myeloid cells, not lymphocytes. This is because the Philadelphia chromosome results from a translocation between chromosomes 9 and 22, leading to the formation of the BCR-ABL fusion gene, which is associated with chronic myeloid leukemia (CML). Choice A is correct as the Philadelphia chromosome results from the shortening of the long arm of chromosome 22. Choice B is incorrect as Philadelphia positivity in CML patients is associated with a worse prognosis. Choice C is correct as the presence of the Philadelphia chromosome is a diagnostic hallmark of CML.

Correct Answer: C

Rationale: The correct answer is C, pernicious anemia. Pernicious anemia is a macrocytic anemia caused by vitamin B12 deficiency affecting red blood cell production. Sideroblastic anemia (A), thalassemia (B), and lead poisoning (D) can all lead to microcytic anemia due to different mechanisms such as impaired hemoglobin synthesis or red blood cell destruction. Pernicious anemia, on the other hand, is not associated with microcytosis.