The wife of a 48-year-old male patient brings him to the eme

[Hijeck]

The wife of a 48-year-old male patient brings him to the emergency room and says that his memory has progressively gotten worse over the last several years. She also says his personality has been changing. The physician notes abnormal writhing movements of the man's limbs and hyper-reactive reflexes. MRI reveals a loss of volume in the neostriatum and cortex. This disease is inherited via an

A. autosomal dominant trait

B. autosomal recessive trait

C. x-linked dominant trait

D. x-linked recessive trait

[Hijeck]

A. Autosomal dominant, Huntington disease

[manindar]

Ingestion of substantial amount of licorice can produce an effect similar to mineralocorticoid excess. Normally cortisol is present in much larger quantity in plasma than aldesterone. Cortisol is structurally similar to aldosterone and can interact intracellular receptor for aldesterone. However, 11-beta hydroxysteroid dehydrogenase found in principal cells of the cortical collecting duct, inactivates cortisol and prevents it from acting on the aldesterone receptor. Licorice contains glycyrrhizic acid. In excessive quantities this inhibits 11 beta hydroxysteroid dehydrogenase and allow cortisol to act on the aldeseterone receptor. As a result, an excessive mineralocorticoid syndrome is produced. Excess mineralocorticoid promotes the retention of urinary Na and the ensuing hypernatremia, resulting in volume expansion and hypertension. Excess mineralocorticoid also causes urinary potassium loss, resulting in hypokalemia. It is the hypokalemia that accounts for patients muscle weakness. The elevated Na suppresses rennin secretion, which in turn, is follwed by reduce level of plasma aldosterone.