Nokea
Which of the following alters the function of thrombin from a procoagulant protein to one that downregulates the formation of fibrinogen?
- A. Protein C
- B. Protein S
- C. Antithrombin
- D. Thrombomodulin
Correct Answer: D
Rationale: Thrombomodulin alters thrombin's function by binding to it and activating protein C. Activated protein C then inhibits factors Va and VIIIa, which are essential for the formation of fibrinogen. Protein C (choice A) also inhibits coagulation, but it doesn't directly alter thrombin's function. Protein S (choice B) enhances protein C's activity but doesn't directly affect thrombin. Antithrombin (choice C) inhibits thrombin and other coagulation factors, but it doesn't specifically alter thrombin's function to downregulate fibrinogen formation.
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The nurse is reviewing the activated partial thromboplastin time for a patient receiving heparin. Which value indicates that the medication is within the therapeutic range?
- A. 2.5 to 9.5 minutes
- B. 9.5 to 11.3 seconds
- C. 1.5 to 2.0 times normal
- D. 2.0 to 3.0 times normal
Correct Answer: C
Rationale: The correct answer is C (1.5 to 2.0 times normal) because the therapeutic range for heparin therapy is typically considered to be 1.5 to 2.0 times the normal control value for activated partial thromboplastin time (aPTT). This range ensures adequate anticoagulation to prevent clot formation without increasing the risk of bleeding. Options A, B, and D are incorrect because they provide ranges that are either too short or too long for the therapeutic goal of heparin therapy. Option A (2.5 to 9.5 minutes) and Option D (2.0 to 3.0 times normal) are outside the typical therapeutic range for heparin, indicating subtherapeutic and supratherapeutic levels, respectively. Option B (9.5 to 11.3 seconds) is also incorrect as it reflects a range for prothrombin time (PT) rather than aPTT.
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: Correct Answer: B (Vitamin B12 deficiency)
Rationale:
1. Mr. XY is a strict vegetarian, avoiding meat, fish, and milk products.
2. Vitamin B12 is mainly found in animal products, crucial for red blood cell production.
3. Vegetarians at risk of B12 deficiency due to limited dietary sources.
4. Anemia can result from B12 deficiency, leading to decreased red blood cell production.
Summary:
A: Iron deficiency - Possible but less likely since vegetarian diets can still provide iron.
C: Defects in erythropoietin production - Unrelated to diet, more related to kidney function.
D: Calcium-deficiency - Not directly related to anemia; more associated with bone health.
A nurse is caring for a client who is scheduled for an outpatient surgical procedure and reports taking aspirin 81 mg daily, including this morning. The nurse should identify that this places the client at risk for which of the following complications?
- A. Uncontrolled bleeding
- B. Myocardial infarction
- C. Respiratory depression
- D. Decreased renal perfusion
Correct Answer: A
Rationale: Rationale: Aspirin is an antiplatelet medication that inhibits platelet aggregation, increasing the risk of uncontrolled bleeding during surgical procedures. By taking aspirin, the client's blood clotting ability is impaired, leading to potential excessive bleeding during and after surgery. This can result in complications such as prolonged bleeding, hematoma formation, and delayed wound healing. Therefore, the correct answer is A: Uncontrolled bleeding.
Summary:
- B: Myocardial infarction is not directly related to taking aspirin; it is actually used to prevent heart attacks.
- C: Respiratory depression is not a common complication associated with aspirin use.
- D: Decreased renal perfusion is not a typical risk of taking aspirin; it primarily affects the cardiovascular system.
A 77-year-old male is admitted to a unit with a suspected diagnosis of acute myeloid leukemia (AML). When planning this patient's care, the nurse should be aware of what epidemiologic fact?
- A. Early diagnosis is associated with good outcomes.
- B. Five-year survival for older adults is approximately 50%.
- C. Five-year survival for patients over 75 years old is less than 2%.
- D. Survival rates are wholly dependent on the patient's pre-illness level of health.
Correct Answer: C
Rationale: The correct answer is C: Five-year survival for patients over 75 years old is less than 2%. This is because older age is a significant negative prognostic factor in acute myeloid leukemia (AML). As individuals age, their overall health and ability to tolerate aggressive treatments decline, leading to poorer outcomes. The survival rate of less than 2% for patients over 75 years old reflects the challenges of treating AML in this age group.
Choice A is incorrect because early diagnosis does not necessarily guarantee good outcomes in AML, especially in older adults where other factors play a significant role. Choice B is incorrect as the five-year survival rate of 50% does not apply to older adults with AML. Choice D is incorrect as survival rates in AML are influenced by various factors beyond just the patient's pre-illness health status.
An 8-year-old boy undergoes a resection of a tumor in the right cerebrum next to the lateral ventricle (supratentorial). The pathologist feels the histology is most consistent with an ependymoma. The tumor is sent for advanced molecular and genetic testing. Which of the following findings would further support a diagnosis of ependymoma?
- A. BRAFKIAA1549 fusion
- B. BRAFV600E mutation
- C. RELA fusion
- D. H3K27M mutation
Correct Answer: C
Rationale: The correct answer is C: RELA fusion. Ependymomas are known to have specific molecular characteristics, with RELA fusion being a common genetic alteration associated with these tumors. The fusion of RELA gene is a key genetic event in the pathogenesis of supratentorial ependymomas. This fusion leads to the activation of the NF-κB signaling pathway, which is important in the development and progression of ependymomas.
Now, let's summarize why the other choices are incorrect:
A: BRAFKIAA1549 fusion - This fusion is typically associated with pilocytic astrocytomas, not ependymomas.
B: BRAFV600E mutation - This mutation is commonly found in other types of brain tumors like pleomorphic xanthoastrocytomas and gangliogliomas, not ependymomas.
D: H3K27M mutation - This mutation is typically seen in diffuse midline gliomas, such as diffuse