Scurvy is:

Correct Answer: A

Rationale: The correct answer is A: Scurvy is a disease caused by a deficiency of vitamin C. This deficiency leads to symptoms such as spongy bleeding gums, bleeding under the skin, and weakness. - Choice B is incorrect because extreme dryness of the conjunctiva is not a symptom of scurvy, and it is more related to a deficiency of vitamin A. - Choice C is incorrect because it describes symptoms of pellagra, a disease caused by a deficiency of niacin, not scurvy. - Choice D is incorrect because it includes all the incorrect options, making it incorrect as well. In summary, the correct choice (A) accurately describes the cause and symptoms of scurvy, while the other choices describe different diseases with unrelated symptoms.

Correct Answer: B

Rationale: The correct answer is B: Rickets. Calcifediol is administered for the treatment of vitamin D deficiency-related conditions like rickets, which is a bone disorder caused by a lack of vitamin D, leading to soft and weak bones. The other choices are incorrect because: A) Primary hyperparathyroidism is treated with medications that target the parathyroid gland, not vitamin D. C) Hypercalcemia is an excess of calcium in the blood and is not treated with calcifediol since it can exacerbate the condition. D) Failure of vitamin D formation in the skin is not an indication for calcifediol administration as it is used to treat vitamin D deficiency, not a failure in its formation.

Correct Answer: D

Rationale: The correct answer is D: Fludrocortisone. Fludrocortisone is a synthetic steroid that primarily exhibits mineralocorticoid activity. It is commonly used to treat adrenal insufficiency due to its potent mineralocorticoid effects. Hydrocortisone (A) is a natural steroid with both glucocorticoid and mineralocorticoid activity. Spironolactone (B) is a potassium-sparing diuretic that acts as an aldosterone antagonist, reducing the effects of aldosterone. Dexamethasone (C) is a synthetic steroid with potent anti-inflammatory and immunosuppressive properties but minimal mineralocorticoid activity.

Correct Answer: C

Rationale: The correct answer is C: Penicillins. Penicillins demonstrate bactericidal effects by interfering with bacterial cell wall synthesis, leading to cell lysis and death. Tetracyclines and macrolides are bacteriostatic, inhibiting bacterial growth but not directly killing them. Choice D is incorrect as not all antibiotics listed exhibit bactericidal effects.

Correct Answer: B

Rationale: Step-by-step rationale for choice B (Taking of drinks with alkaline pH) being correct: 1. Sulfonamides are more soluble in alkaline solutions, reducing the risk of precipitation. 2. Alkaline pH helps in preventing the formation of crystals in the urine. 3. Alkaline drinks can help maintain a higher urinary pH, minimizing the risk of crystalluria. 4. This approach is supported by medical literature and pharmacological principles. Summary: - Choice A (Taking of drinks with acid pH) is incorrect as it may exacerbate sulfonamide precipitation and crystalluria. - Choice C (Taking of saline drinks) is incorrect as it does not address the solubility issues of sulfonamides. - Choice D (Restriction of drinking) is incorrect as hydration is essential to prevent crystalluria.