Causes spurious decrease in MCV

Correct Answer: A

Rationale: The correct answer is A: Cryofibrinogen. Cryofibrinogenemia can cause a spurious decrease in Mean Corpuscular Volume (MCV) due to the presence of cryoprecipitates in the blood sample, leading to underestimation of red blood cell volume. Cryofibrinogen does not actually alter the size of the red blood cells, but its presence interferes with the accurate measurement of MCV. Summary: B: Hyperglycemia does not affect MCV. C: Autoagglutination causes clumping of red blood cells, leading to falsely elevated MCV. D: High white blood cell count does not directly impact MCV.

Correct Answer: B

Rationale: Certainly. The correct answer is B (FALSE) because antimalarial drugs and high dose birth control do not increase riboflavin levels. Riboflavin is a water-soluble vitamin that is not affected by these medications. Choice A (TRUE) is incorrect as there is no evidence to support an increase in riboflavin due to these drugs. Choice C (Sometimes) is incorrect because there is no situation where these medications would lead to an increase in riboflavin. Choice D (Only in pregnancy) is also incorrect as riboflavin levels are not specifically affected by pregnancy or these medications.

Correct Answer: D

Rationale: Step-by-step rationale for choice D (Liver impairment) being correct: 1. Warfarin is metabolized in the liver. 2. Liver impairment can alter the metabolism of warfarin, leading to potential over-anticoagulation. 3. Monitoring of INR levels is crucial in patients with liver impairment to prevent bleeding risks. 4. Caution is necessary to adjust warfarin dosages based on liver function tests. Summary of why other choices are incorrect: A: Alcoholic liver disease - Although liver function is compromised, specific liver impairment poses a higher risk with warfarin. B: Gastrointestinal bleeding - While a concern with anticoagulants, liver impairment directly affects warfarin metabolism. C: Recent neurosurgery - Not directly related to liver function, so does not impact warfarin metabolism.

Correct Answer: A

Rationale: The correct answer is A: Stage 0 in the Rai Staging System for Chronic Lymphocytic Leukemia (CLL). In stage 0, patients have lymphocytosis without any other symptoms or signs of advanced disease. This indicates a low-risk group with a favorable prognosis and no need for immediate treatment. Other choices are incorrect because they correspond to stages with increasing severity and additional symptoms such as lymphadenopathy, hepatosplenomegaly, anemia, or thrombocytopenia, which are not present in this case.

Correct Answer: A

Rationale: The correct answer is A: To replace lost lipids in the membrane. Lipid exchange in RBCs is crucial for membrane maintenance and repair. Lipids can be lost due to various factors like oxidative stress or mechanical stress. Replacing lost lipids helps maintain the integrity and functionality of the membrane. Summary of other choices: B: Providing a mechanism for excretion of lipid-soluble waste products is not a primary function of lipid exchange in RBCs. C: Ensuring symmetry between the lipid layers is important for membrane stability but not the primary purpose of lipid exchange in RBCs. D: Providing lipid-soluble nutrients to RBCs is not the main function of lipid exchange; RBCs primarily rely on glucose for energy.