All of the following are consistent with non-proliferative diabetic retinopathy except:

Correct Answer: C

Rationale: The correct answer is C: Neovascularization. Non-proliferative diabetic retinopathy is characterized by early changes such as retinal vascular microaneurysms, blot hemorrhages, and cotton-wool spots. Neovascularization is a feature of proliferative diabetic retinopathy, not non-proliferative. Neovascularization refers to the growth of abnormal new blood vessels in the retina, which can lead to severe vision loss if not treated promptly. In summary, neovascularization is not consistent with non-proliferative diabetic retinopathy, as it is a hallmark of the proliferative stage.

Correct Answer: C

Rationale: The correct answer is C: Glucose-6-phosphatase deficiency. This enzyme is essential for gluconeogenesis and glycogenolysis, so its deficiency leads to fasting hypoglycemia. Galactosaemia (A) can cause hypoglycemia due to impaired galactose metabolism. Insulinoma (B) results in excess insulin production causing hypoglycemia. Systemic carnitine deficiency (D) can lead to hypoglycemia by impairing fatty acid oxidation, but it does not directly cause fasting hypoglycemia as seen in Glucose-6-phosphatase deficiency.

Correct Answer: A

Rationale: Aldosterone increases potassium excretion by promoting the reabsorption of sodium and water in the kidneys, leading to potassium excretion. This helps maintain electrolyte balance. Other choices are incorrect because aldosterone does not directly increase water loss, is released in response to low blood volume, and is deficient in Addison's disease.

Correct Answer: B

Rationale: The correct answer is B: Kidney disease. Oral contraceptive pills are contraindicated in patients with kidney disease due to the risk of impaired drug clearance and potential adverse effects on renal function. Breast cancer (A), liver disease (C), and prior history of deep venous thrombosis (D) are all contraindications to the use of oral contraceptives due to increased risks of complications such as thrombosis or exacerbation of underlying conditions.

Correct Answer: C

Rationale: Step-by-step rationale for why choice C is correct: 1. Growth hormone stimulates increased production of insulin-like growth factor 1 (IGF-1). 2. In acromegaly, there is excessive production of growth hormone. 3. Excess growth hormone leads to elevated levels of IGF-1. 4. IGF-1 is primarily produced in the liver in response to growth hormone stimulation. 5. Therefore, increased levels of growth hormone in acromegaly stimulate increased production of IGF-1 from the liver. Summary: - Choice A is incorrect because vasopressin is not produced from the adrenal glands in response to growth hormone. - Choice B is incorrect because vasopressin is not produced from the liver in response to growth hormone. - Choice D is incorrect because IGF-1 is mainly produced in the liver, not from the adrenal glands, in response to growth hormone.

Correct Answer: B

Rationale: The correct answer is B: Cretinism. Cretinism is the most common cause of preventable mental deficiency worldwide due to severe iodine deficiency during pregnancy. Iodine is crucial for thyroid hormone production, which is essential for fetal brain development. Beriberi disease (A) is caused by thiamine deficiency and affects the nervous system, not mental deficiency. Folate deficiency (C) can cause neural tube defects but not mental deficiency. Vitamin A deficiency (D) can lead to blindness and immune system issues, but not the most common cause of preventable mental deficiency.

Correct Answer: C

Rationale: Step-by-step rationale: 1. Tertiary hyperparathyroidism occurs due to prolonged secondary hyperparathyroidism in response to chronic renal failure. 2. In chronic renal failure, impaired kidney function leads to reduced activation of vitamin D and impaired calcium regulation. 3. Persistent hypocalcemia triggers the parathyroid glands to overproduce parathyroid hormone, leading to tertiary hyperparathyroidism. 4. Rickets (choice A) is associated with vitamin D deficiency, pseudohypoparathyroidism (choice B) is a genetic disorder, and malabsorption syndrome (choice D) affects nutrient absorption, but they are not commonly linked to tertiary hyperparathyroidism.

Correct Answer: B

Rationale: The correct answer is B: Bitemporal Hemianopsia. Pituitary adenomas can compress the optic chiasm, leading to bitemporal hemianopsia. This occurs due to the loss of peripheral vision on both sides. Carpo-pedal spasm (A) is associated with hypocalcemia, Chvostek's sign (C) is a facial spasm seen in hypocalcemia, and tremor (D) can be seen in conditions such as Parkinson's disease, but they are not specific to pituitary adenoma. Bitemporal hemianopsia is a classic sign of pituitary adenoma due to its location near the optic chiasm.

Correct Answer: C

Rationale: Rationale for choice C (FSH) being correct: 1. FSH stimulates Sertoli cells in the testes. 2. Sertoli cells produce androgen binding globulin (ABG). 3. ABG binds to testosterone, regulating its availability. 4. FSH indirectly influences testosterone levels via ABG production. Summary of incorrect choices: A. LH stimulates Leydig cells to produce testosterone, not Sertoli cells. B. GnRH regulates the release of FSH and LH but does not directly stimulate ABG production. D. Oxytocin is not involved in the regulation of Sertoli cells or ABG production in males.