Nokea
A 30 year old patient had presented with fever and posterior cervical lymphadenopathy over the past two years. Which is the most probably causative organism?
- A. Trypanosoma cruzi
- B. Trypanosoma brucei rhodesiense
- C. Trypanosoma brucei gambiense
- D. Leishmania donovani
Correct Answer: C
Rationale: The correct answer is C: Trypanosoma brucei gambiense. This is the most likely causative organism because the patient's presentation of fever and posterior cervical lymphadenopathy is consistent with African trypanosomiasis, also known as sleeping sickness, which is caused by T. brucei gambiense. This parasite is transmitted by the tsetse fly in sub-Saharan Africa. The other choices (A, B, D) are not the correct causative organism for African trypanosomiasis and do not match the clinical presentation described in the question. Trypanosoma cruzi causes Chagas disease, Trypanosoma brucei rhodesiense causes a more acute form of African trypanosomiasis, and Leishmania donovani causes visceral leishmaniasis, which typically presents with splenomegaly and hepatomegaly rather than posterior cervical lymphadenopathy.
You may also like to solve these questions
A nurse is caring for a client who is about to begin taking aspirin to reduce the risk of a cardiovascular event. The nurse should identify that the drug inhibits platelet aggregation by which of the following mechanisms?
- A. Activating thromboxane A2
- B. Blocking adenosine diphosphate receptor agonists
- C. Suppressing specific clotting factors
- D. Inhibiting cyclooxygenase action in platelets
Correct Answer: D
Rationale: The correct answer is D: Inhibiting cyclooxygenase action in platelets. Aspirin works by irreversibly inhibiting cyclooxygenase, specifically COX-1, in platelets. By inhibiting COX-1, aspirin prevents the formation of thromboxane A2, which is a potent platelet aggregator. This action reduces platelet aggregation and ultimately decreases the risk of clot formation leading to a cardiovascular event.
Choice A is incorrect because aspirin does not activate thromboxane A2, but rather inhibits its formation. Choice B is incorrect as aspirin does not block adenosine diphosphate receptors. Choice C is incorrect as aspirin does not suppress specific clotting factors, but rather inhibits platelet function through the mechanism described above.
Your patient with relapsed high-risk neuroblastoma returns to your care after travelling to an outside institution for [131]I-MIBG therapy. In the weeks following [131]I-MIBG therapy, what adverse events directly attributable to this therapy will the patient most likely encounter?
- A. Myelosuppression requiring growth factor and blood product support
- B. Severe mucositis
- C. Hemorrhagic cystitis
- D. Symptomatic hypothyroidism
Correct Answer: A
Rationale: Rationale for Correct Answer (A): Myelosuppression requiring growth factor and blood product support is the most likely adverse event following [131]I-MIBG therapy due to its impact on bone marrow. The therapy targets neuroblastoma cells, but can also affect normal bone marrow function, leading to myelosuppression. Growth factors and blood products are often needed to support hematopoiesis.
Summary of Incorrect Answers:
B: Severe mucositis: Not a common adverse event associated with [131]I-MIBG therapy, as it primarily affects the bone marrow.
C: Hemorrhagic cystitis: Not directly related to [131]I-MIBG therapy, which does not typically cause bladder toxicity.
D: Symptomatic hypothyroidism: While [131]I-MIBG therapy can affect thyroid function, symptomatic hypothyroidism is not the most likely adverse event following this therapy.
Which of the following characteristics are similar with respect to Factor VIII and von Willebrand factor (vWF)?
- A. Both are made in endothelial cells and megakaryocytes.
- B. Both are activated by thrombin.
- C. They are present in normal to high relative amounts in newborns.
- D. They are stored in Weibel-Palade bodies in endothelial cells.
Correct Answer: C
Rationale: Step-by-step rationale:
1. Factor VIII and vWF are present in normal to high relative amounts in newborns due to the physiological adaptation to the low levels at birth.
2. Both Factor VIII and vWF play crucial roles in the coagulation cascade, but their levels decrease after birth.
3. The other choices are incorrect because:
- A: Factor VIII is primarily made in endothelial cells and vWF is made in endothelial cells and platelets, not megakaryocytes.
- B: Thrombin activates Factor VIII but not vWF, which is activated by shear stress.
- D: Factor VIII is stored in Weibel-Palade bodies, but vWF is stored in platelets and endothelial cells, not in the Weibel-Palade bodies.
In microcytic hypochromic anaemia
- A. Red cells are larger with normal staining
- B. Red blood cell count is increased
- C. Haemtocrit and mean corpuscular haemoglobin are normal
- D. Red cells are smaller with a pale large central pallor
Correct Answer: D
Rationale: In microcytic hypochromic anemia, the correct answer is D because red cells are smaller (microcytic) and have a pale large central pallor (hypochromic). This is due to decreased hemoglobin content and iron deficiency. Choice A is incorrect as red cells are smaller, not larger. Choice B is incorrect as the red blood cell count is typically decreased in this type of anemia. Choice C is incorrect as both hematocrit and mean corpuscular hemoglobin are decreased in microcytic hypochromic anemia, not normal. Therefore, the correct answer is D based on the characteristic features of microcytic hypochromic anemia.
NADPH is a product of the hexose monophosphate pathway (HMP) in the red blood cell. The NADPH is used for the
- A. Synthesis of fatty acids
- B. Reduction of glutathione
- C. Formation of ATP
- D. Removal of oxygen radicals
Correct Answer: B
Rationale: The correct answer is B: Reduction of glutathione. In the hexose monophosphate pathway (HMP), NADPH is generated, which serves as a reducing agent. This NADPH is crucial for reducing oxidized glutathione back to its reduced form, maintaining cellular antioxidant defense. This process helps to protect cells from oxidative damage and maintain redox balance.
Now, let's summarize why the other choices are incorrect:
A: Synthesis of fatty acids - NADPH is indeed involved in fatty acid synthesis, but in the context of red blood cells, the primary role of NADPH is in reducing glutathione.
C: Formation of ATP - NADPH is not directly involved in ATP synthesis. ATP is primarily produced through processes like glycolysis and oxidative phosphorylation.
D: Removal of oxygen radicals - While NADPH indirectly contributes to the removal of oxygen radicals through its role in reducing glutathione, it is not the primary function of NAD