Correct statements about cortisol (hydrocortisone) include all of the following, EXCEPT:

Correct Answer: D

Rationale: The correct answer is D because the statement is false. The half-life of cortisol in circulation is around 60-90 minutes, not hours. Choice A is correct as cortisol is indeed synthesized from cholesterol. Choice B is correct as ACTH regulates cortisol secretion. Choice C is incorrect - most cortisol is inactivated in the liver.

Correct Answer: D

Rationale: The correct answer is D: Thiamine. Beri-beri is caused by a deficiency of thiamine (Vitamin B1), which is essential for energy metabolism and nerve function. Thiamine deficiency leads to symptoms like fatigue, muscle weakness, nerve damage, and heart problems. Riboflavin (A), Ascorbic acid (B), and Nicotinic acid (C) deficiencies do not directly cause Beri-beri. Riboflavin is important for energy production, Ascorbic acid is Vitamin C important for immunity, and Nicotinic acid is Vitamin B3 important for metabolism.

Correct Answer: A

Rationale: The correct answer is A because LDL is a lipoprotein that contains high amounts of cholesterol and is associated with increased risk of atherosclerosis and coronary artery disease. LDL is often referred to as beta-lipoprotein due to its density. Choice B is incorrect as it describes HDL, which contains small amounts of cholesterol and triglycerides, and is associated with a decreased risk of heart disease. It is also known as alpha-lipoprotein. Choice C is incorrect as it describes VLDL (very low-density lipoprotein), which carries most cholesterol from the liver to the tissues due to its large proportion of lipids to proteins. Choice D is incorrect as it describes chylomicrons, which are large lipoprotein particles created by the absorptive cells of the small intestine. They transport lipids to adipose tissue for breakdown by lipoprotein lipase.

Correct Answer: A

Rationale: The correct answer is A: TRUE. Probenecid and sulfinpyrazone are indeed uricosuric drugs used to decrease urate levels in patients with tophaceous gout or frequent gouty attacks. Probenecid works by inhibiting urate reabsorption in the kidneys, leading to increased urate excretion. Sulfinpyrazone also increases urate excretion. Choice B is incorrect because the statement is true. Choice C is incorrect as it implies all choices are correct, which is not the case. Choice D is incorrect as it states that none of the choices are correct, which is not true in this scenario.

Correct Answer: B

Rationale: The correct answer is B: Defective bone mineralization. Etidronate is a bisphosphonate used to treat osteoporosis by inhibiting bone resorption, leading to increased bone density. However, long-term use can result in defective bone mineralization, leading to brittle or weakened bones. A: Anorexia is not a known side effect of etidronate and is more commonly associated with other medications or medical conditions. C: Hypercalcemia is unlikely with etidronate use since it works to reduce calcium loss from bones. D: Cardiac arrhythmias are not a typical side effect of etidronate and are more commonly associated with other medications or underlying heart conditions.