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 sequence is appropriate because methotrexate can interfere with the activity of L-asparaginase if given concurrently, affecting the efficacy of both drugs. Administering L-asparaginase immediately after the methotrexate infusion allows for optimal therapeutic effects of both medications without compromising their individual actions. Choice A (Administer L-asparaginase during the methotrexate infusion) is incorrect because it may lead to drug interactions and reduced effectiveness of both drugs. Choice C (Administer both drugs at the same time) is incorrect for the same reason as choice A. Choice D (Administer methotrexate 24 hours after the asparaginase) is incorrect as it does not follow the optimal timing for these medications during treatment.

Correct Answer: B

Rationale: The correct answer is B. Platelet transfusions are rarely successful in patients with autoimmune thrombocytopenia. Rationale: 1. Patients with autoimmune thrombocytopenia have low platelet levels due to immune destruction. 2. Platelet transfusions may not be effective as the underlying autoimmune process continues to destroy transfused platelets. 3. Reviewing transfusion records of these patients would likely show low success rates of platelet transfusions. Summary of Incorrect Choices: A: Frozen storage of platelets increasing units available is not directly related to the success of platelet transfusions in autoimmune thrombocytopenia. C: Platelet units do carry a risk of transmitting hepatitis C infection, so this conclusion is incorrect. D: Preference for pooled donor platelets over single-donor platelets does not address the success of platelet transfusions in autoimmune thrombocytopenia.

Correct Answer: D

Rationale: The correct answer is D: Transmembrane iron exporter. Ferroportin is a transmembrane protein that functions as an iron exporter, allowing iron to move out of cells. This is crucial in iron metabolism as it facilitates the release of iron from cells into the bloodstream for transport to other tissues. A: A form of storage iron in intestinal mucosal cells - This is incorrect as ferroportin is not involved in storing iron in cells. B: A transport protein in the plasma - This is incorrect as ferroportin is not primarily a plasma protein but rather a transmembrane protein. C: A receptor protein on the surface of erythroid progenitors - This is incorrect as ferroportin is not a receptor protein but an exporter protein.

Correct Answer: A

Rationale: The correct answer is A: Extremity. Rhabdomyosarcoma in extremities has a worse prognosis due to difficulties in achieving complete surgical resection and higher risk of metastasis. Extremity tumors are often larger and more challenging to remove completely, leading to a higher chance of recurrence and poor outcomes. Prostate (B) and neck (D) sites are more favorable as they are easier to access for surgery and have lower rates of metastasis. Infratemporal fossa (C) is also a difficult site, but extremity tumors generally have a worse prognosis due to their anatomical and surgical challenges.

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 a legal and ethical requirement before any invasive procedure like a bone marrow aspiration and biopsy. Without valid consent, the procedure cannot proceed. Administering pain medication (A) can be important, but ensuring consent comes first. Having the client shower (C) is not a priority before the procedure. Premedicating with sedatives (D) may not be necessary for every client and should be based on individual assessment.