A 9-year-old boy is being treated for standard-risk acute lymphoblastic leukemia. His treatment protocol calls for administration of intravenous methotrexate and intramuscular L-asparaginase during interim maintenance chemotherapy. What is the most appropriate sequence of drug administration?

Correct Answer: B

Rationale: The correct answer is B: Administer L-asparaginase immediately after the methotrexate infusion. This is the most appropriate sequence because methotrexate can impair the activity of L-asparaginase if administered together. By waiting to administer L-asparaginase after the methotrexate infusion, the efficacy of both drugs is maximized without interference. Administering L-asparaginase during the methotrexate infusion (Choice A) would lead to decreased effectiveness of L-asparaginase. Administering both drugs at the same time (Choice C) is not recommended due to potential drug interactions. Administering methotrexate 24 hours after the asparaginase (Choice D) does not optimize the synergistic effects of the drugs during interim maintenance chemotherapy.

Correct Answer: B

Rationale: Step-by-step rationale for why answer B is correct: 1. Autoimmune thrombocytopenia is a condition where the body's immune system attacks and destroys its own platelets. 2. Platelet transfusions in patients with autoimmune thrombocytopenia are less likely to be successful due to the underlying immune response. 3. Reviewing transfusion records of subjects with this condition would likely show a pattern of unsuccessful platelet transfusions. 4. This conclusion is supported by medical knowledge and understanding of autoimmune thrombocytopenia. Summary: - Choice A is incorrect because frozen storage of platelets does not necessarily increase units available in the context of the study. - Choice C is incorrect as platelet units can carry a risk of transmission for hepatitis C infection. - Choice D is incorrect as the preference for pooled donor platelets over single-donor platelets is not a conclusion that can be drawn from the study.

Correct Answer: D

Rationale: Ferroportin is a transmembrane iron exporter responsible for releasing iron from cells into the bloodstream. It is crucial in regulating systemic iron levels. Choice A is incorrect as storage iron is typically stored as ferritin. Choice B is incorrect as ferroportin is not found in the plasma but on cell membranes. Choice C is incorrect as erythroid progenitors do not directly interact with ferroportin. Therefore, the correct answer is D as it accurately describes the function of ferroportin in iron metabolism.

Correct Answer: A

Rationale: The correct answer is A: Extremity. Rhabdomyosarcoma has a better prognosis when located in the extremities compared to other sites due to easier surgical resection and less risk of metastasis. Prostate (B) is less common in children and has a poorer prognosis. Infratemporal fossa (C) and neck (D) sites have a higher risk of local invasion and metastasis, leading to a worse prognosis compared to extremity sites.

Correct Answer: B

Rationale: The correct answer is B: Ensure that valid consent is in the medical record. This is the priority because obtaining informed consent is essential before any invasive procedure like a bone marrow aspiration and biopsy. It ensures that the client understands the procedure, risks, benefits, and alternatives. Administering pain medication (A), having the client shower (C), and premedicating with sedatives (D) are important aspects of care but obtaining valid consent is crucial for legal and ethical reasons before proceeding with the procedure.