Nokea
Bone marrow responds to iron therapy by increasing erythropoietic activity. Which of the following in bone marrow would most likely indicate erythropoiesis?
- A. Myelocytes
- B. Reticulocytes
- C. Ring sideroblasts
- D. Target cells
Correct Answer: B
Rationale: The correct answer is B: Reticulocytes. Reticulocytes are immature red blood cells released by the bone marrow into the bloodstream in response to increased erythropoietic activity. They indicate ongoing erythropoiesis as they mature into fully functional red blood cells. Myelocytes (A) are immature granulocytic precursors, not involved in erythropoiesis. Ring sideroblasts (C) are seen in conditions like sideroblastic anemia and indicate abnormal iron metabolism. Target cells (D) are red blood cells with a central bull's eye appearance and are associated with conditions like liver disease and thalassemias, not specifically erythropoiesis.
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A 9-month-old boy has been referred to you for the evaluation of an enlarged abdomen. Imaging studies show a large liver mass (PRETEXT III). Alfa-fetoprotein is 98 ng/mL, and a CT scan of the lungs show bilateral lung metastases. A needle biopsy is performed, and you are planning to review the specimen with the pathologist. Which of the following diagnoses are you suspecting?
- A. Pure fetal histology hepatoblastoma
- B. Embryonal sarcoma of the liver
- C. Fibrolamellar hepatocellular carcinoma
- D. Small cell undifferentiated hepatoblastoma
Correct Answer: D
Rationale: The correct answer is D: Small cell undifferentiated hepatoblastoma. In hepatoblastoma, the presence of lung metastases indicates a high-risk tumor. The small cell undifferentiated subtype is more aggressive with a poorer prognosis compared to other subtypes. The AFP level is lower than typically seen in hepatoblastoma, but still within the range for this diagnosis. Pure fetal histology hepatoblastoma (choice A) is less common and usually associated with a better prognosis. Embryonal sarcoma of the liver (choice B) is a distinct entity with different histological features. Fibrolamellar hepatocellular carcinoma (choice C) typically occurs in older children and has a different imaging appearance.
A patient is scheduled for upcoming surgery. He is on nonsteroidal anti-inflammatory drugs (NSAIDs) for rheumatoid arthritis. You are being asked what to do with his medications for the surgery. What is the mechanism of action of NSAIDS?
- A. Irreversible inhibition of cyclooxygenase 1
- B. Irreversible inhibition of cyclooxygenase 2
- C. Reversible inhibition of cyclooxygenase 1
- D. Reversible inhibition of cyclooxygenase 2
Correct Answer: C
Rationale: The correct answer is C: Reversible inhibition of cyclooxygenase 1. NSAIDs work by reversibly inhibiting cyclooxygenase enzymes, particularly COX-1 and COX-2, which are involved in the synthesis of prostaglandins. In this case, reversible inhibition is crucial because it allows for the temporary suppression of prostaglandin production, leading to pain relief and anti-inflammatory effects.
Explanation of other choices:
A: Irreversible inhibition of cyclooxygenase 1 - This is incorrect because NSAIDs typically do not irreversibly inhibit COX-1.
B: Irreversible inhibition of cyclooxygenase 2 - This is incorrect because NSAIDs do not irreversibly inhibit COX-2.
D: Reversible inhibition of cyclooxygenase 2 - This is incorrect because while NSAIDs can inhibit COX-2, the primary target is COX-1 for their therapeutic effects.
A nurse is caring for a client who has hemophilia A and is about to begin taking desmopressin to prevent bleeding. The nurse should monitor the client for which of the following adverse reactions?
- A. Weight loss
- B. Edema
- C. Polyuria
- D. Bradycardia
Correct Answer: B
Rationale: The correct answer is B: Edema. Desmopressin is a medication that can cause fluid retention, leading to edema. Hemophilia A clients are at risk for bleeding, so desmopressin is given to improve clotting. Weight loss (A), polyuria (C), and bradycardia (D) are not common adverse reactions of desmopressin. Weight loss and polyuria are more associated with diabetes insipidus, a condition that desmopressin is used to treat. Bradycardia is not a typical adverse reaction of desmopressin.
The main vector transmitting malaria in Sabah is Anopheles balabacensis. This vector breeds in
- A. Artificial containers in urban centres
- B. Drains
- C. Temporary collecting of water in jungles
- D. Rock pools in control areas
Correct Answer: C
Rationale: The correct answer is C: Temporary collecting of water in jungles. Anopheles balabacensis is a forest-dwelling mosquito species commonly found in jungle environments. They prefer to breed in temporary water collections such as rainwater puddles, small ponds, or stream edges within the jungle. Breeding in urban areas, drains, or rock pools would not be typical for this species based on its natural habitat preference. Therefore, the most suitable breeding site for this vector in Sabah would be temporary water collections in jungles.
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.