The following thyroid inhibitor does not produce goiter when given in over dose:

Correct Answer: C

Rationale: Step-by-step rationale for correct answer (C): 1. Radioactive iodine destroys overactive thyroid tissue, reducing hormone production. 2. Unlike anti-thyroid medications (A and B), radioactive iodine does not directly inhibit thyroid function. 3. Sodium thiocyanate (D) inhibits iodine uptake by the thyroid, potentially leading to goiter. Summary of incorrect choices: A. Propyl thiouracil and B. Carbimazole are anti-thyroid medications that can cause goiter in overdose. D. Sodium thiocyanate can lead to goiter by interfering with iodine uptake.

Correct Answer: B

Rationale: The correct answer is B: Young adults with recent onset of Grave's disease. Radioactive iodine is the treatment of choice for this category of thyrotoxic patients because it effectively destroys the overactive thyroid tissue, providing a long-term solution. Children are not typically treated with radioactive iodine due to concerns about potential long-term effects on growth and development. Elderly patients with ischaemic heart disease may not be suitable candidates due to the risk of exacerbating heart conditions. Pregnant women should not receive radioactive iodine treatment as it can harm the developing fetus. Therefore, the most appropriate choice is B based on the effectiveness and safety considerations for each category of patients.

Correct Answer: B

Rationale: The correct answer is B: Tyrosine protein kinase receptor. The insulin receptor is a type of receptor that belongs to the tyrosine kinase family. It works by phosphorylating tyrosine residues on itself and other proteins, triggering a signaling cascade that regulates glucose uptake and metabolism. This process is crucial for maintaining blood glucose levels. Option A is incorrect because the insulin receptor is not an ion channel regulating receptor. Option C is incorrect as the insulin receptor does not belong to the G-protein coupled receptor family. Option D is incorrect as the insulin receptor is indeed a tyrosine protein kinase receptor.

Correct Answer: C

Rationale: Step 1: Tight control of hyperglycemia in diabetic patients aims to reduce complications. Step 2: Multiple daily insulin injections or insulin pumps can lead to hypoglycemia. Step 3: Hypoglycemic reactions are associated with tight control methods. Step 4: Therefore, option C is correct as it highlights the higher incidence of hypoglycemic reactions with round-the-clock tight control.

Correct Answer: D

Rationale: The correct answer is D: Sodium bicarbonate. In diabetic ketoacidosis, the blood becomes acidic due to ketone accumulation. Administering sodium bicarbonate can worsen the acidosis by shifting the pH too rapidly. Insulin is essential to lower blood glucose levels, IV fluids are necessary to correct dehydration, and potassium chloride is needed to replenish electrolytes. Sodium bicarbonate is not recommended as it can lead to potential complications.