Myxopapillary ependymoma of lumbosacral region with metastasis to both cerebellopontine angles: report of a rare case

Introduction Myxopapillary ependymomas are low grade tumours that are known to recur locally even after complete excision, but metastasis to distant sites is extremely uncommon. Case report We report an unusual case of lumbo-sacral myxopapillary ependymoma in a 13-year-old boy with metastasis to both cerebellopontine angles. To the best of our knowledge, this is the youngest patient of metastatic myxopapillary ependymoma.     

Alteration of the lipid composition of rat testicular plasma membranes by dietary (n-3) fatty acids changes the responsiveness of Leydig cells and testosterone synthesis

Experiments were conducted to assess whether changing dietary fat composition altered phospholipid composition of rat testicular plasma membranes in a manner that altered receptor-mediated action of luteinizing hormone (LH)/human chorionic gonadotropin (hCG). Weanling rats were fed diets that provided high or low cholesterol intakes and that were enriched with linseed oil, fish oil or beef tallow for 4 wk. Feeding diets high in (n-3) fatty acids decreased plasma and testicular plasma membrane 20:4(n-6) content. A marked reduction of the 22:5(n-6) content and an increase in the 22:6(n-3) content of testicular plasma membrane was found only in animals fed fish oil. A decrease in binding capacity of the gonadotropin (LH/hCG) receptor in the plasma membrane, with no change in receptor affinity, was observed for animals fed either linseed oil or fish oil diets. Dietary treatments that raised plasma membrane cholesterol content and the cholesterol to phospholipid ratio in the membrane were associated with increased binding capacity of the gonadotropin receptor. Feeding diets high in 18:3(n-3) vs. those high in fish oil altered receptor-mediated adenylate cyclase activity in a manner that depended on the level of dietary cholesterol. Feeding diets high in cholesterol or fish oil increased basal and LH-stimulated testosterone synthesis relative to that in animals fed the low cholesterol diet containing linseed oil. It is concluded that changing the fat composition of the diet alters the phospholipid composition of rat testicular plasma membranes and that this change in composition influences membrane-mediated unmasking of gonadotropin receptor-mediated action in testicular tissue.     

Postoperative wound infections following myocutaneous flap surgery in spinal injury patients.

Severe pressure ulcers in patients with spinal cord injury are frequently treated by using musculocutaneous (m-c) flap surgery. There have been few studies of the use of perioperative antibiotics to prevent postoperative infection in this setting. We reviewed 74 m-c flap surgeries in 53 patients (41 male and 12 female) from October 1989 for one year. The sites involved were ischial (31), sacral (24), trochanteric (18), deltoid (2), olecranon (1) and posterior thigh (1). An antibiotic was usually administered perioperatively for 5 days. Patients were followed for a median of 30 (8-96) weeks. Postoperative infections occurred at a median of 12 (4-25) days in 6 of 74 (8%) surgeries. The organisms cultured from the 6 infected wounds were: Bacteroides sp. (4), Proteus mirabilis (2), E. coli (2), MRSA (2), and others (6--each isolated once). These results indicate that antibiotics did not prevent postoperative infection in approximately 8% of patients undergoing m-c surgery. The frequency of isolation of Bacteroides sp. from these infections suggests that anaerobic bacteria may persist in healing pressure ulcers and perioperative antibiotics might include coverage for anaerobic bacteria.     

Bilateral posterior lens dislocation in Marfan's syndrome

Complete dislocation of the lens is a rare feature of Marfan's Syndrome. We observed four cases of bilateral complete posterior dislocation of the lens in established cases of Marfan's Syndrome over a one year period. An ophthalmologist may encounter infrequently, unilateral posterior dislocation in one eye and ectopia lentis in the other, but bilateral spontaneous posterior dislocation is rare. All our cases had associated vitreous degeneration with vitreous herniating into the anterior chamber. The pathogenesis of complete posterior dislocation in Marfan's Syndrome is discussed.     

Computed tomography of the abdomen with fat density oral contrast medium.

A 12.5% corn oil-emulsion (COE) was tested as an oral contrast agent for abdominal computed tomography (CT) examinations in 100 patients. The results were compared with those obtained from another group of patients who received a conventional, high-density, oral contrast agent (2-3% iodinated solution). There was no statistically significant difference in the subjects' tolerance to the two agents (P greater than 0.05). There was, however, a significant improvement in image quality with COE (P less than 0.05). Gastrointestinal tract discrimination, and mucosal and mural visualisation was of higher quality with fat density oral contrast medium than with the high-density contrast agent. These data suggest that COE should be considered for routine use as an alternative to conventional high density oral contrast agents in upper abdominal CT.     

Changes in the lipid composition and activities of isocitrate dehydrogenase and isocitrate lyase during encystation of Acanthamoeba culbertsoni strain A-1

The contents of total lipids, total sterols, total and individual phospholipids: lysophosphatidyl choline, lysophosphatidyl ethanolamine, phosphatidyl choline, phosphatidyl ethanolamine and alkali-stable phospholipids I and II, were significantly lower in mature cysts of Acanthamoeba culbertsoni strain A-1 than in trophozoites. The major constituent sterols of trophozoites, viz. ergosterol, 7-dehydrostigmasterol and 7,22,25-tridehydrostigmasterol which resolved as a single spot on thin-layer chromatography, disappeared in the cysts. When trophozoites grown in the presence of [14C]acetate were transferred to encystation medium, there was a steady decrease in the radioactivity in the lipids and acid-soluble fraction (glycogen) of the encysting cells while the radioactivity increased in the akali-insoluble fraction (cellulose). The activity of isocitrate lyase in the encysting cells steadily increased up to 24 h of encystation, followed by a slight decrease during 24-32 h, but the activity of isocitrate dehydrogenase steadily decreased up to 32 h of encystation, beyond which time no enzyme activity was detected. Inhibitors of isocitrate lyase, glycolate and maleate at 8.5 to 34 mM concentration inhibited encystation by 18-67%.