Gynaecomastia can be treated with:

Correct Answer: C

Rationale: The correct answer is C: Bromocriptine. Gynaecomastia is often caused by hormonal imbalances, specifically increased estrogen levels relative to testosterone. Bromocriptine is a dopamine agonist that inhibits prolactin secretion, which can help restore hormonal balance and reduce gynaecomastia. Chlorpromazine (A) is an antipsychotic with no direct effect on hormonal levels. Cimetidine (B) is a histamine H2 receptor antagonist used for acid reflux and ulcers, not for gynaecomastia. Metoclopramide (D) is a dopamine receptor antagonist that can actually exacerbate gynaecomastia by increasing prolactin levels.

Correct Answer: A

Rationale: The correct answer is A. Auricular fibrillation is not a complication of overtreatment with thyroxine. Thyroxine is a thyroid hormone that can increase heart rate and cardiac output, potentially leading to complications such as angina pectoris, congestive heart failure, and acceleration of atherosclerosis. However, auricular fibrillation, also known as atrial fibrillation, is not directly caused by thyroxine over-treatment. It is important to differentiate between the potential complications of thyroxine therapy to ensure proper management and avoid unnecessary risks to the patient's health.

Correct Answer: A

Rationale: Propyl thiouracil inhibits the enzyme 5'-deiodinase, which is responsible for converting thyroxine (T4) to triiodothyronine (T3) peripherally. Methimazole and carbimazole primarily inhibit thyroid hormone synthesis. Radioactive iodine destroys thyroid tissue. Therefore, choice A is correct as it specifically targets the peripheral conversion of T4 to T3.

Correct Answer: D

Rationale: The correct answer is D: 60 days. This is because the physical half-life of a radioactive substance refers to the time it takes for half of the radioactive atoms to decay. In the case of 131I, it has a physical half-life of 8 days. However, 131I undergoes beta decay to form stable xenon-131, which has a longer half-life. Therefore, the effective half-life of 131I is longer, approximately 60 days. Summary: A: 8 hours - Incorrect, too short for the physical half-life of 131I. B: 8 days - Partially correct, but the effective half-life is longer. C: 16 days - Incorrect, not the effective half-life of 131I. D: 60 days - Correct, reflects the effective half-life of 131I due to its decay process.

Correct Answer: C

Rationale: The correct answer is C: Facilitation of neoglucogenesis by liver. Insulin's main role is to lower blood glucose levels by promoting glucose uptake into cells (A) and glycogen synthesis in the liver (B), and inhibiting lipolysis in adipose tissue (D). Neoglucogenesis is the process of synthesizing new glucose molecules, which is not a function of insulin. Therefore, choice C is incorrect as insulin does not facilitate neoglucogenesis.