30-year-old with fever, cervical lymphadenopathy for 2 years. Most likely organism?

Correct Answer: B

Rationale: The correct answer is B: Trypanosoma brucei gambiense. This parasite causes African Trypanosomiasis (sleeping sickness), characterized by fever, lymphadenopathy, and neurological symptoms. Choice A, Trypanosoma cruzi, causes Chagas disease, not presenting with lymphadenopathy. Choice C, Leishmania donovani, causes visceral leishmaniasis with hepatosplenomegaly, not cervical lymphadenopathy. Choice D, Onchocerca volvulus, causes onchocerciasis (river blindness) with skin and eye manifestations, not cervical lymphadenopathy.

Correct Answer: D

Rationale: The correct answer is D, "RA with excess blasts in transformation". This choice indicates progression to acute myeloid leukemia, which has the poorest prognosis among MDS subtypes. Refractory anemia (A) has a relatively better prognosis compared to transformation. RA with ring sideroblasts (B) and RA with excess blasts (C) are also MDS subtypes, but they do not indicate the same level of disease progression as RA with excess blasts in transformation. Therefore, choice D is the correct answer due to its association with the most severe outcome in MDS.

Correct Answer: B

Rationale: The correct answer is B: Promastigote. In vitro diagnosis of leishmaniasis involves culturing the promastigote stage of the parasite. Promastigotes are the infective stage found in the sandfly vector and are typically used for laboratory diagnosis. Amastigotes are the intracellular forms found in mammalian hosts, not in vitro. Trypomastigotes are seen in Trypanosoma species, not Leishmania. Schizonts are not typically used for diagnosis of leishmaniasis.

Correct Answer: C

Rationale: The correct answer is C: Release of histamine. Early local inflammation is characterized by the release of histamine from mast cells and basophils in response to tissue injury. Histamine causes vasodilation and increased vascular permeability, leading to redness, swelling, and heat at the site of inflammation. Fever (choice A) typically occurs during systemic inflammation, not in early local inflammation. Anaphylactic shock (choice B) is a severe, systemic allergic reaction involving widespread histamine release, not confined to the local area of inflammation. The attack of cytotoxic T cells (choice D) is part of the adaptive immune response and is not typically involved in the early stages of inflammation.

Correct Answer: A

Rationale: The correct answer is A because assessing the conjunctiva of the eye is the best way to evaluate pallor in a dark-skinned client. Pallor is often difficult to detect on the skin in dark-skinned individuals. The conjunctiva is a mucous membrane that covers the eye and can show signs of pallor, such as a paler color. This method provides a reliable indicator of pallor in dark-skinned clients. Choice B (having the client open hand widely) and choice C (looking at the roof of the mouth) are not as effective in assessing pallor in dark-skinned clients because these areas may not show visible signs of pallor. Choice D (palpating for mild swelling) is also not relevant to assessing pallor, as swelling and pallor are distinct signs with different assessment methods.