Vitamin K deficiency. Which coagulation factor not affected?

Correct Answer: C

Rationale: The correct answer is C, Factor VIII. Vitamin K deficiency primarily affects the synthesis of Factors II, VII, IX, and X. Factor VIII is not dependent on vitamin K for its synthesis since it is a co-factor for Factor IX. Therefore, Factor VIII levels remain unaffected in Vitamin K deficiency. Factors II, VII, and IX are all vitamin K-dependent factors, making them incorrect choices.

Correct Answer: A

Rationale: The correct answer is A: Acute myeloid leukemia. The key clues are the presence of 15% myeloblasts and reduced erythropoiesis. In AML, there is an abnormal increase in myeloblasts in the bone marrow, leading to reduced production of normal blood cells, including erythrocytes. Myelofibrosis (C) is characterized by fibrotic changes in the bone marrow, not an increase in blasts. ALL (B) primarily affects lymphoid cells, not myeloblasts. MDS (D) involves ineffective hematopoiesis and dysplastic changes, but not necessarily a high blast count.

Correct Answer: D

Rationale: The correct answer is D: Schizonticidal activity. Artemisinin targets and kills the asexual blood stage of the malaria parasite Plasmodium falciparum, known as schizonts. This action helps in treating resistant falciparum malaria. Gametocidal activity (A) targets sexual stage parasites, preventing transmission but not directly treating the infection. Preventing hypnozoites (B) is specific to Plasmodium vivax and ovale, not falciparum. Sporontocidal activity (C) targets mosquito-stage parasites, which is not relevant for treating resistant falciparum malaria.

Correct Answer: B

Rationale: Step-by-step rationale: 1. IgM is the first immunoglobulin produced in primary immune response. 2. It is released by plasma cells when an antigen is encountered. 3. IgM is efficient in agglutination and complement activation. Summary of incorrect choices: A: IgA is mainly found in mucosal areas. C: IgE is involved in allergic reactions. D: IgG is the most abundant immunoglobulin in the bloodstream.

Correct Answer: A

Rationale: The correct answer is A: Clopidogrel (Plavix). Clopidogrel is a platelet inhibitor that works by inhibiting the platelet activation and aggregation process. It specifically targets the ADP receptor on platelets, preventing them from clumping together. This action helps to prevent blood clots from forming, making it an effective antiplatelet medication. Enoxaparin (B) is a low molecular weight heparin that works by inhibiting factors Xa and IIa, making it an anticoagulant rather than a platelet inhibitor. Reteplase (C) is a thrombolytic agent that works by converting plasminogen to plasmin, aiding in the breakdown of blood clots. Warfarin (D) is an anticoagulant that works by inhibiting the synthesis of vitamin K-dependent clotting factors.