In which segment of the nephron is glucose reabsorbed?

Correct Answer: D

Rationale: The correct answer is D: Proximal convoluted tubule. Glucose reabsorption primarily occurs in the proximal convoluted tubule due to the presence of specialized glucose transporters. Step-by-step rationale: 1. Glucose is filtered in the glomerulus and enters the renal tubules. 2. In the proximal convoluted tubule, glucose is reabsorbed through sodium-glucose cotransporters (SGLT) and facilitated diffusion via glucose transporters (GLUT). 3. The loop of Henle is primarily responsible for water and electrolyte reabsorption, not glucose. 4. The collecting duct mainly concentrates urine by reabsorbing water and electrolytes, not glucose. 5. The distal convoluted tubule is involved in fine-tuning electrolyte balance and regulating acid-base balance, not glucose reabsorption.

Correct Answer: D

Rationale: The correct answer is D: Ampicillin. It is considered safe to use in newborn babies due to its efficacy against common bacterial infections in this age group. Ampicillin is a broad-spectrum antibiotic that is often prescribed for neonatal sepsis and meningitis. It is also well-tolerated and has minimal side effects in newborns. A: Chloramphenicol is not recommended in newborns due to the risk of gray baby syndrome. B: Trimethoprim/Sulfamethoxazole can cause kernicterus and other adverse effects in newborns. C: Tetracyclines can lead to tooth discoloration and inhibit bone growth in newborns.

Correct Answer: A

Rationale: Rationale: 1. Ceftriaxone is a third-generation cephalosporin known for broad-spectrum coverage. 2. It has excellent activity against gram-negative anaerobes such as Bacteroides fragilis. 3. It is also one of the cephalosporins that can penetrate the blood-brain barrier. 4. The other choices do not have the same anaerobic coverage or BBB penetration. Summary: - B: Cefoxitin is a second-generation cephalosporin with anaerobic coverage but does not cross the BBB. - C: Cephalexin is a first-generation cephalosporin with limited anaerobic activity and no BBB penetration. - D: Cefixime is a third-generation cephalosporin with no anaerobic activity or BBB penetration.

Correct Answer: B

Rationale: The correct answer is B: Valacyclovir. Valacyclovir is a commonly prescribed antiviral medication used to treat genital herpes simplex virus infections. Firstly, it is a nucleoside analog that inhibits viral DNA replication, helping to reduce symptoms and prevent outbreaks. Additionally, Valacyclovir is well-tolerated and effective in managing herpes infections in young adults. Choice A, Amantadine, is an antiviral primarily used for treating influenza A virus infections and is not effective against herpes simplex viruses. Choice C, Lamivudine, is an antiretroviral medication used to treat HIV and hepatitis B infections, not herpes simplex virus infections. Choice D, Zanamivir, is also an antiviral used for treating influenza infections and is not indicated for genital herpes simplex virus infections.

Correct Answer: A

Rationale: The correct answer is A: Zidovudine. Zidovudine is known to cause bone marrow suppression, leading to decreased white blood cell and red blood cell counts. In this case, the patient's peripheral WBC count of 1000 and low hemoglobin after starting therapy are indicative of hematologic abnormalities consistent with zidovudine use. Acyclovir, Foscarnet, and Amantadine do not typically cause bone marrow suppression and are not associated with the hematologic abnormalities seen in this patient.