A 30-year-old man has a history of heart transplant and is receiving long-term steroids to prevent rejection. The patient is due for routine vaccines. Attenuated vaccines are contraindicated in this patient because the antigen is:

Correct Answer: A

Rationale: The correct answer is A: live and can cause infection. In patients like the one described with a history of heart transplant and receiving long-term steroids, who are immunocompromised, live attenuated vaccines are contraindicated. Live vaccines contain weakened (attenuated) forms of the virus or bacteria, which can replicate and cause mild infections in healthy individuals but can lead to serious infections in immunocompromised individuals. Choices B, C, and D are incorrect because attenuated vaccines are not mutated, not inactive, and not pathogenic in healthy individuals, respectively.

Correct Answer: A

Rationale: The correct answer is Vitamin B12. Vitamin B12 deficiency can lead to megaloblastic anemia and neurological symptoms, including lower extremity paresthesias. Folate deficiency can also cause megaloblastic anemia but typically does not present with neurological symptoms. Iron deficiency leads to microcytic anemia, not megaloblastic anemia. Vitamin K deficiency is associated with coagulation abnormalities, not megaloblastic anemia.

Correct Answer: D

Rationale: Anemia of chronic inflammation is characterized by normochromic and normocytic red blood cells. In chronic inflammation, the body typically produces enough red blood cells, but they are often smaller and paler than normal (normocytic and normochromic). Choices A, B, and C are incorrect because hypochromic and microcytic, hypochromic and macrocytic, and normochromic and microcytic anemias are not typically associated with chronic inflammation.

Correct Answer: B

Rationale: HbAS indicates sickle cell trait, not full-blown sickle cell anemia. Choice A is incorrect because HbAS indicates the presence of the sickle cell trait. Choice C is incorrect as sickle cell anemia is characterized by HbSS, not HbAS. Choice D is incorrect as thalassemia is a different type of hemoglobin disorder not indicated by HbAS.

Correct Answer: B

Rationale: In peripheral artery disease, pain in the lower extremities worsens with the elevation of the extremity because it diverts blood flow away from the affected area, exacerbating the pain. Choices A, C, and D are incorrect. Resting doesn't increase blood flow, a dependent position doesn't lead to blood pooling in this context, and pain worsening due to touch or massage is not a typical feature of peripheral artery disease.