A 30 year old patient had presented with fever and posterior cervical lymphadenopathy over the past two years. Which is the most probably causative organism?

Correct Answer: C

Rationale: The correct answer is C: Trypanosoma brucei gambiense. This is the most probable causative organism because the patient's presentation of fever and posterior cervical lymphadenopathy over a prolonged period aligns with the chronic infection caused by Trypanosoma brucei gambiense, which leads to African Trypanosomiasis (sleeping sickness). Trypanosoma cruzi (choice A) causes Chagas disease, which typically presents with acute symptoms such as fever and swelling at the site of infection. Trypanosoma brucei rhodesiense (choice B) causes acute African Trypanosomiasis with a more rapid progression compared to gambiense. Leishmania donovani (choice D) causes visceral leishmaniasis, which presents with prolonged fever, splenomegaly, and pancytopenia, but not typically with cervical lymphadenopathy.

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: A

Rationale: Rationale: A: Correct - Iron absorption primarily occurs in the duodenum and upper small intestine, not the large intestine. B: Incorrect - Intrinsic factor is necessary for Vitamin B12 absorption, not iron. C: Incorrect - Ascorbic acid (Vitamin C) actually enhances iron absorption. D: Incorrect - Absorption is decreased in hereditary hemochromatosis, a condition of iron overload.

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.