Nokea
Platelet aggregation is an important event in hemostasis. Which of the following statement is true for platelet aggregation in vascular injury?
- A. There will be initial vasodilation
- B. Clotting factors play no role in its formation
- C. Platelets change their shape during the process
- D. Serotonin stimulates platelet aggregation
Correct Answer: C
Rationale: Platelets change their shape during platelet aggregation to form a plug at the site of vascular injury. This process involves platelets adhering to the injured blood vessel wall, becoming activated, and then changing shape to form a clot. Vasodilation is not an initial response, as vasoconstriction occurs to reduce blood loss. Clotting factors are essential for clot formation and play a significant role. Serotonin is released from platelets during aggregation but does not directly stimulate aggregation. The correct choice, C, directly correlates with the physiological process of platelet aggregation in response to vascular injury.
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Peripheral bl. Picture is most useful in:
- A. NHL
- B. multiple myeloma
- C. myelodysplastic syndrome
- D. CML
Correct Answer: D
Rationale: The correct answer is D: CML. Peripheral blood picture is most useful in diagnosing CML due to the characteristic presence of increased mature and immature granulocytes, especially neutrophils, in the blood smear. This finding is known as a "left-shift" and is a hallmark of CML. In contrast, NHL (choice A) primarily involves lymphocytes, multiple myeloma (choice B) is characterized by abnormal plasma cells, and myelodysplastic syndrome (choice C) typically presents with dysplastic changes in blood cell precursors. Therefore, based on the specific blood cell findings, CML is the most likely diagnosis when observing a peripheral blood picture.
A 5-year-old boy is evaluated for apparent ongoing hemolysis. His hemoglobin is 9.5 g/dL, with 8% reticulocytes and MCV 87 fL. Platelets and leukocytes are normal. His direct antiglobulin test (DAT) is negative. No cold agglutinin is detectable. His family history is negative for blood disorders. Peripheral smear reveals basophilic stippling in 10% of the red blood cells. Given these findings, which of the following blood disorders is most likely?
- A. Rh-null disease
- B. Hereditary pyropoikilocytosis
- C. Glucose phosphate isomerase deficiency
- D. Unstable hemoglobin
Correct Answer: E
Rationale: I'm sorry, but it seems like there might be a mistake in the question as there is no option "E" provided. Could you please provide the correct answer choice so that I can give you a step-by-step rationale for why that answer is correct?
The International Normalized Ratio (INR) was developed for the purpose of
- A. Monitoring heparin therapy
- B. Monitoring oral anticoagulant therapy
- C. Screening for intrinsic clotting system abnormalities
- D. Standardizing the monitoring of warfarin therapy
Correct Answer: D
Rationale: Rationale:
1. INR standardizes PT results across labs.
2. Warfarin therapy requires close monitoring.
3. INR helps adjust warfarin dose accurately.
4. INR is not specific to heparin, oral anticoagulants, or screening for clotting system abnormalities.
Summary:
A: Heparin is monitored by aPTT.
B: Oral anticoagulant therapy is monitored by INR.
C: Intrinsic clotting abnormalities are not detected by INR.
D: Warfarin therapy monitoring is standardized by INR.
An 8-year-old girl presents with National Cancer Institute (NCI) Standard Risk acute pre-B-cell acute lymphoblastic leukemia. Her family history is significant for her mother having been diagnosed with breast cancer at age 34 years and a maternal uncle who developed osteosarcoma as a teenager. What cytogenetic abnormality is most likely to be detected in this patient?
- A. t(1;19)
- B. CRLF2 rearrangement with a JAK2 mutation
- C. KMT24 rearrangement
- D. Hypodiploidy with a modal chromosome number of 34
Correct Answer: D
Rationale: The correct answer is D: Hypodiploidy with a modal chromosome number of 34. In pediatric pre-B-cell acute lymphoblastic leukemia, hypodiploidy (fewer than 44 chromosomes) is associated with poor prognosis. A modal chromosome number of 34 is specifically linked to high-risk disease.
A: t(1;19) is characteristic of pre-B-cell acute lymphoblastic leukemia but is associated with intermediate prognosis, not standard risk.
B: CRLF2 rearrangement with a JAK2 mutation is seen in a subset of high-risk acute lymphoblastic leukemia cases, not standard risk.
C: KMT24 rearrangement is not a known cytogenetic abnormality in acute lymphoblastic leukemia.
Which of the following is not the criteria in the international prognostic index for non Hodgkin's lymphoma?
- A. Number of extranodal sites
- B. LDH level
- C. Lymphocyte count
- D. Performance status
Correct Answer: C
Rationale: The correct answer is C: Lymphocyte count. The International Prognostic Index (IPI) for non-Hodgkin's lymphoma includes factors such as age, number of extranodal sites, LDH level, performance status, and stage. Lymphocyte count is not a specific criteria in the IPI. This index is used to predict the outcome of patients with aggressive lymphomas. A higher score indicates a worse prognosis. A low lymphocyte count is not a consistent prognostic factor for non-Hodgkin's lymphoma, unlike the other factors listed. Therefore, choice C is not a criteria in the IPI, making it the correct answer.