Which hemoglobin does not predispose to sickling?

Correct Answer: C

Rationale: The correct answer is C: Hb-F. Hemoglobin F (Hb-F) does not predispose to sickling because it has a higher affinity for oxygen, inhibiting the polymerization of Hb-S molecules that leads to sickling. Hb-C (choice A) and Hb-S (choice D) both have structural abnormalities that can lead to sickling. Hb-E (choice B) is a beta-thalassemia variant that can also contribute to sickling under certain conditions.

Correct Answer: B

Rationale: B: Stored in mast cells. Heparin is not stored in mast cells; it is synthesized in mast cells and basophils. Heparin is stored in granules within these cells and released upon activation. This is why choice B is false. The other choices are true: A) SubQ injection can lead to hematomas due to its anticoagulant effect, C) Heparin binds to antithrombin III to inhibit thrombin, and D) Protamine sulfate is used as an antidote to heparin overdose by binding to heparin and neutralizing its effects.

Correct Answer: C

Rationale: The correct answer is C: Lymphocyte count. In the International Prognostic Index (IPI) for non-Hodgkin’s lymphoma, lymphocyte count is not a criterion because it focuses on factors such as age, stage, LDH level, extranodal sites, and performance status. Lymphocyte count does not directly impact the prognosis or risk assessment in non-Hodgkin’s lymphoma. The other choices (A, B, D) are included in the IPI as they are important prognostic factors that help determine the severity and outcome of the disease.

Correct Answer: B

Rationale: The correct answer is B: Defects in peripheral proteins. Spherocytosis is a condition characterized by red blood cells with a spherical shape due to defects in the peripheral proteins such as spectrin. This leads to decreased cell flexibility, making the cells more prone to premature destruction in the spleen. Choice A is incorrect because spherocytosis is not caused by abnormal integral proteins. Choice C is incorrect as increased roleaux refers to red blood cells sticking together, not the cause of spherocytosis. Choice D is incorrect as sickle-shaped cells are characteristic of sickle cell anemia, not spherocytosis.

Correct Answer: B

Rationale: The correct answer is B because NHL commonly originates from B cells. B cells give rise to most NHL subtypes, making the B-cell phenotype more common. Choice A is incorrect because RS cells are characteristic of Hodgkin's lymphoma, not NHL. Choice C is incorrect as NHL can involve non-contiguous lymph nodes. Choice D is incorrect as some NHL subtypes can have a leukemic phase.