281 - Civatte bodies is aka colloid bodies; in lichen planus; anucleate - necrotic basal cells becoming incorporated into the inflamed papillary epidermis.
282 - Miller Fisher test is in normal pressure hydrocephalus - objective gait assessment before and after 30 cc CSF removed reflecting prognosis for shunting.
283 - Osler-Weber-Rendu disease is hereditary hemorrhagic telangiectasia - larger lesions can be a source of chronic blood loss - systemic emboli - hypoxemia - hepatic dysfunction - and a high-output cardiac failure; important risk factor for brain abscess - especially in affected patients with clubbing - cyanosis - and/or polycythemia; use aminocaproic acid (an antifibrinolytic agent).
284 - Rapoport-Luebering shunt is in red blood cells - pathway converting 1 -3-diphosphoglyceric acid to 2 -3-DPG and then to 3-phosphoglyceric acid; enzyme is diphosphoglycerate synthetase; 2 -3-DPG reduces affinity of hemoglobin for oxygen; 2 -3-DPG rises with alkalosis and decreases with acidosis - result of effect of pH on enzyme.
285 - Alexander’s disease is leukodystrophy-like neurodegenerative disease presenting in infancy or childhood; characterized by Rosenthal fibers.
286 - Hirschprung’s disease is megacolon; congenital disorder characterized by colonic dilatation proximal to an aganglionic - contracted distal colon and rectum; caused by gestational failure of neural crest cells to migrate to distal colon; an AD form has been reported with mutations of the RET gene - and an AR form with mutation of the endothelin-B-receptor gene.
287 - Looser’s zones is radiolucent narrow lines that lie either at right angles or obliquely to the cortical outlines of bones and often transect them; bilateral and symmetric - found at the axillary margins of the scapula - lower ribs - neck of the proximal femurs - and posterior regions of the proximal ulnas; related either to stress fractures or to mechanical erosion by penetrating nutrient arteries; aka Milkman’s fractures.
288 - Williams’s syndrome is supravalvular aortic stenosis - mental retardation - elfin facies - association with hypercalcemia due to abnormal sensitivity to vitamin D - idiopathic hypercalcemia of pregnancy - loquacious personality - abnormally sensitive hearing; from deletion in elastin gene and probably several adjacent genes.
289 - Burnett’s syndrome is far-advanced milk-alkali syndrome - due to long-standing calcium and alkali ingestion; severe hypercalcemia - irreversible renal failure - and phosphate retention - may be accompanied by ectopic calcification; also Cope’s syndrome.
290 - Prader-Willi syndrome is deletion of 15q11-q13 - paternally derived; uncontrollable hyperphagia after 12 months.