How can a colony-stimulating factor affect the patient's erythrocyte count?

Correct Answer: A

Rationale: Colony-stimulating factors are substances that stimulate the production of blood cells in the bone marrow. Erythrocytes are red blood cells, so a colony-stimulating factor would specifically stimulate the growth of red blood cells, leading to an increase in the patient's erythrocyte count. Choice B is incorrect because colony-stimulating factors do not suppress T-cell production. Choice C is incorrect because colony-stimulating factors do not inhibit protein synthesis. Choice D is incorrect because colony-stimulating factors do not stimulate antibody production; they primarily affect the production of blood cells.

Correct Answer: A

Rationale: The correct answer is A: Zoster vaccine. The Zoster vaccine is recommended for the prevention of shingles in individuals aged 50 years and older. Shingles is caused by the reactivation of the varicella-zoster virus, the same virus that causes chickenpox. The vaccine helps reduce the risk of developing shingles and decreases the severity and duration of the illness if it occurs. Choices B, C, and D are incorrect: Haemophilus influenzae Type b (Hib) vaccine is used to prevent infections caused by Haemophilus influenzae type b, Human papillomavirus (HPV) vaccine is used to prevent HPV infections that can lead to cervical cancer and other cancers, and Pneumococcal polyvalent vaccine is used to protect against infections caused by the bacterium Streptococcus pneumoniae.

Correct Answer: C

Rationale: Rifampin (Rifadin) achieves a therapeutic action against both intracellular and extracellular tuberculosis organisms by inhibiting the synthesis of RNA. This action interferes with bacterial RNA synthesis, leading to the suppression of protein synthesis in the bacteria, ultimately causing their death. Option A is incorrect because rifampin is primarily metabolized in the liver, but this is not how it exerts its bactericidal effects. Option B is incorrect as rifampin does not bind to acetylcholine. Option D is also incorrect as rifampin does not cause phagocytosis.

Correct Answer: A

Rationale: In a patient with an autoimmune disorder, a viral infection can trigger an immune response where lymphocytes mistakenly recognize the host's tissue as foreign. This can lead to an exacerbation of the autoimmune condition. Choice B is incorrect because erythrocytes are not responsible for destroying T cells. Choice C is incorrect as thymus involution weakens the immune response, making the patient more susceptible to infections rather than increasing the infection risk. Choice D is unrelated to the potential effects of a viral infection in a patient with an autoimmune disorder.

Correct Answer: B

Rationale: The correct answer is B: Candida albicans. Candida albicans is a common fungal agent responsible for causing vaginal yeast infections characterized by itching and burning. It is known to overgrow in the vagina, especially when the normal vaginal flora is disrupted, such as during antibiotic use. Cryptococcus neoformans is more associated with causing meningitis in immunocompromised individuals, not vaginal symptoms. Aspergillus is more commonly associated with lung infections and allergic reactions, not vaginal infections. Dermatophytes typically cause skin infections like ringworm, not vaginal symptoms.