Nokea
Which of the following best characterizes the function of ferroportin in iron metabolism?
- A. A form of storage iron in intestinal mucosal cells
- B. A transport protein in the plasma
- C. A receptor protein on the surface of erythroid progenitors
- D. Transmembrane iron exporter
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.
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You are discussing prognosis with the mother of a patient with stage 3, group III rhabdomyosarcoma. Which of the following is the most unfavorable primary site?
- A. Extremity
- B. Prostate
- C. Infratemporal fossa
- D. Neck
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.
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?
- A. Administer L-asparaginase during the methotrexate infusion.
- B. Administer L-asparaginase immediately after the methotrexate infusion.
- C. Administer both drugs at the same time to maximize synergistic activity.
- D. Administer methotrexate 24 hours after the asparaginase.
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.
Mr XY was found to be anemic. During history taking, he informed his doctor that he was a strict vegetarian who did not consume any meat, fish or milk products.
- A. Iron deficiency
- B. Vitamin B12 deficiency
- C. Defects in erythropoietin production
- D. Calcium-deficiency
Correct Answer: B
Rationale: The correct answer is B: Vitamin B12 deficiency. As a strict vegetarian who does not consume any meat, fish, or milk products, Mr XY is at risk for Vitamin B12 deficiency. Vitamin B12 is primarily found in animal products and is essential for red blood cell production. Anemia can result from Vitamin B12 deficiency, leading to symptoms such as fatigue and weakness. Iron deficiency (A) is also common in vegetarians, but in this case, the focus is on Vitamin B12 due to the exclusion of all animal products. Defects in erythropoietin production (C) are not related to Mr XY's dietary choices. Calcium-deficiency (D) is not directly related to anemia in this scenario.
A 13-year-old Hispanic girl is found to have a WBC count of 6,500/mm3 with 40% Auer rod–containing granular blasts that, by flow cytometry, express very bright CD33 but are negative for human leukocyte antigen–DR isotype (HLA-DR). She is oozing blood around her peripheral IV site. Coagulation studies reveal an international normalized ratio (INR) of 3.4, a fibrinogen of 170, and a markedly elevated D-dimer. Marrow aspirate shows nearly 90% blasts with a similar morphology. You send the marrow to the fluorescence in situ hybridization (FISH) lab and request STAT testing for the most likely recurrent genetic abnormality based on the clinical presentation. How do you plan to initiate therapy?
- A. Perform a lumbar puncture to determine leukemic involvement, then proceed with induction chemotherapy.
- B. Begin therapy with all-trans retinoic acid (ATRA) immediately while aggressively managing coagulopathy with blood product support.
- C. Start dexamethasone and hydroxyurea immediately while aggressively managing coagulopathy with blood product support.
- D. Start induction chemotherapy, obtain HLA typing, and start a donor search because of the poor prognosis associated with this leukemic phenotype.
Correct Answer: B
Rationale: The correct answer is B: Begin therapy with all-trans retinoic acid (ATRA) immediately while aggressively managing coagulopathy with blood product support.
Rationale:
1. The clinical presentation describes acute promyelocytic leukemia (APL), characterized by Auer rod-containing blasts, coagulopathy (elevated INR, D-dimer), and CD33 positivity. ATRA is the standard treatment for APL.
2. ATRA induces differentiation of leukemic promyelocytes, reducing the risk of disseminated intravascular coagulation (DIC) and bleeding.
3. Aggressively managing the coagulopathy with blood product support is crucial to prevent hemorrhagic complications.
Summary:
A: Not needed as the clinical presentation already suggests APL. Lumbar puncture is not indicated for APL diagnosis.
C: Dexamethasone and hydroxyurea are not standard treatments for APL. Immediate ATRA therapy is preferred.
D
The nurse assesses a patient who has numerous petechiae on both arms. Which question should the nurse ask the patient?
- A. Do you take salicylates?
- B. Are you taking any oral contraceptives?
- C. Have you been prescribed antiseizure drugs?
- D. How long have you taken antihypertensive drugs?
Correct Answer: A
Rationale: The correct answer is A: Do you take salicylates? Petechiae can be a sign of salicylate use, which can cause bleeding disorders. By asking about salicylates, the nurse can determine if the petechiae are related to medication. Choice B is not directly related to petechiae. Choice C is more specific to antiseizure drugs and not commonly associated with petechiae. Choice D is unrelated to petechiae and focuses on hypertension management. Asking about salicylates is the most appropriate to assess potential medication-induced petechiae.