全膝关节置换术后的骨溶解：胫骨盘表面的修饰及聚乙烯衬垫灭菌方法对其的影响术 后5至10年的报告

背景：从关节和胫骨假体聚乙烯衬垫后表面转移磨损碎屑，是全膝关节置换术后假体周围骨溶解的主要原因。全膝人工关节假体设计随时问而发生变化，例如对胫骨盘近端表面的粗糙度和聚乙烯衬垫的灭菌方法。我们假设胫骨盘表面抛光和采用空气中γ射线照射之外的其他方法对衬垫灭菌，可降低骨溶解的发生率。方法：从1987年至1998年，我们采用后十字韧带保留型的解剖型组配式全膝人工关节假体系列。对300名患者施行365例全膝关节置换术。术后5至10年，对这些患者的膝关节摄正、侧位X线片。由两位关节置换专家对X线片上的骨溶解状况进行单独评定（骨溶解的界定标准为假体周围存在边缘清晰的非线性松质骨丢失区）。结果：在粗糙表面的胫骨盘的242例膝关节中，使用空气中γ射线照射灭菌的衬垫固定，有34％（82例）骨溶解阳性。用惰性气体中γ射线照射或没有照射的衬垫与抛光表面连接的98例膝关节中，有9％（9例）骨溶解阳性。骨溶解与六项因素相关，这些因素为：一项与患者（男性）相关、一项与胫骨盘（近端表面抛光）相关、三项与聚乙烯衬垫（加工的原材料、灭菌方法及存放时间）相关及一项与手术技术（股骨假体与胫骨假体间的过伸）相关。结论：在这类假体设计中，胫骨盘近端表面采用抛光及衬垫采用更为先进的灭菌方法（不用空气中γ射线照射灭菌）能显著减少骨溶解的发生率，但不能避免骨溶解。     

Seasonal covariation of the circadian phases of rectal temperature and slow wave sleep onset

There is a scarcity of well-controlled studies of the seasonal variation in circadian rhythmicity. In the present study, the circadian phase of rectal temperature and the onset of slow wave sleep were studied in a series of twelve 24-h experiments, one each month of the year, for six healthy subjects under controlled conditions in a climatic chamber. In winter, as compared with summer, the average circadian rhythm of rectal temperature was phase delayed by 45 min, and the average onset of slow wave sleep was phase delayed by 40 min. The temporal relationship between the circadian phase of rectal temperature and the timing of slow wave sleep was maintained throughout the year. Habitual rising and retiring times covaried as well. Furthermore, the circadian rhythm of rectal temperature followed the timing of the photoperiod across the year, but had a much smaller range of seasonal variation. Apparently, the seasonal variation in the photoperiodic zeitgeber is largely compensated for by the stabilizing influence of secondary zeitgebers. However, in healthy subjects some effect of photoperiodic variation can still be observed.     

Disproportional impact of the revised AIDS surveillance definition on the AIDS incidence among drug users compared to homosexual men

The impact of changes in 1993 of the old 1987 WHO/CDC AIDS casedefinition was studied in a cohort of 153 HIV-infected injectiondrug users (IDUs) and 502 HIV-infected homosexual men in Amsterdam.It appeared that the extension in Europe of the old AIDS definitionto also include recurrent pneumonia, pulmonary tuberculosisand invasive cervical neoplasia, strongly increases the numberof persons diagnosed with AIDS among IDUs, but will hardly influencethe AIDS incidence among homosexual men. As recurrent pneumoniaand pulmonary tuberculosis are present among drug users withhigh CD4 cell counts, the incidence of these diseases may partlybe determined by environmental factors. The extension of theold 1987 AIDS definition in the USA with CD4 count <200 cells/mm³In addition to the 3 above-mentioned diseases, will also havea larger impact on drug users than on homosexual men.     

Deuterium Isotope Effect on the Metabolism of the Flame Retardant Tris(2,3-dibromopropyl) Phosphate in the Isolated Perfused Rat Liver

The metabolism of tris(2,3-dibromopropyl) phosphate (Tris-BP)was compared with that of completely deuterated Tris-BP (D15-Tris-BP)in an isolated, recirculating rat liver perfusion system inorder to determine the relative quantitative importance of twodifferent biotransformation pathways of Tris-BP: (i) cytochromeP450-mediated metabolism and (ii) GSH S-transferase-mediatedmetabolism. To accomplish this we quantitated the biliary excretionof S-(3-hydroxypropyl)glutathione (GSOH) as a marker metabolitefor cytochrome P450-mediated metabolism and that of S-(2,3-dihydroxypropyl)glutathione (GSOHOH) as a marker metabolite for GSH S-transferase-mediatedmetabolism. Completedeuterium substitution of Tris-BP significantlydecreased the formation of GSOH, whereas there was no effecton the formation of GSOHOH. Because our previous studies showeda large decrease in genotoxicity of D15-Tris-BP compared toTris-BP, the present results support our hypothesis that cytochromeP450-mediated metabolism is responsible for the genotoxic effectsof Tris BP in the rat liver.     

Surgical Treatment of Supraventricular Tachycardia: A Five-Year Experience

Two hundred and eight patients underwent operative therapy of supraventricular tachycardia between June 1984 and June 1986. There were 196 patients with Wolff-Parkinson-White syndrome, one with AV nodal reentry, two with atrial flutter, one with ectopic atrial tachycardia, three with paroxysmal sinus tachycardia, and five with atrial fibrillation. Map guided or direct surgery was performed in all patients except the three with atrial fibrillation. Direct surgery was generally successful with failures including one patient with Wolff-Parkinson-White syndrome, one with atrial flutter, and the three patients with paroxysmal sinus tachycardia. There was no mortality. Major complications were uncommon and included three resternotomies for bleeding, one chylopericardium. Six patients required reoperation.     

Effects of medium- and long-chain triglycerides on sleep and thermoregulatory processes in neonates

Sleep processes and body temperature regulation of neonates are never taken into account in the evaluation of nutrients, although these functions are implicated in the regulation of energy metabolism and are influenced by the nutritional state and its metabolic consequences. Medium-chain triglycerides (MCT) are currently used in paediatric units during the first weeks of because they are considered to be a rapid source of energy, easy to assimilate for growing premature infants, whose digestive function is immature. However, no study has described the thermic effect of these nutrients on body temperature regulation and sleep. The present study aimed at analysing the influence of three feeding formulas with different content of MCT on sleep processes and on thermoregulation of neonates fed until desired intake was reached. Whatever the thermal conditions (thermal equilibrium or cool environment), the MCT-fed groups had higher body temperatures and than groups fed without MCT, for whom total sleep time was reduced at thermal equilibrium. In this group, the large amount of quiet sleep seems to favour a strategy of conserving energy . Higher energy expenditure in MCT-fed groups is not harmful to growth rate since nutritional efficiency is even better reflected by a larger body mass gain. The thermic effect of MCT contributes to lessening the vulnerability of neonates exposed to low incubator temperatures.     

Pituitary hormones and the small bowel: effect of hypophysectomy on intestinal adaptation to small bowel resection in the rat*

Abstract. The influence of pituitary hormones on intestinal adaptation to small bowel resection was studied by examining jejunal and ileal structure and function in control and in sham-operated rats, and in animals with 50% proximal or distal resection which were divided into three main groups: normally-fed, hypophysectomized, and pair-fed. The pituitary was removed 2 weeks before intestinal surgery and gut structure and function were studied 4 weeks later. The effectiveness of hypophysectomy was confirmed by histological examination of the aspirated pituitary, and by showing a significant subsequent reduction in weight of the testes and adrenals. Food intake and body weight fell significantly after removing the pituitary; intestinal surgery caused a transient further decrease in food intake. Measurements of intestinal villus height and crypt depth, indices of mucosal mass (mucosal wet weight, protein and DNA content/cm intestine), measurements of mucosal a-glucosidase activity, and in vivo galactose absorption/unit length of intestine all showed comparable results. In rats with an intact intestine, resection resulted in mucosal hyperplasia and increased segmental absorption. Following hypophysectomy, there was marked mucosal hypoplasia and hypofunction which seemed to be due largely to associated hypophagia since comparable changes were found in the pair-fed, sham-operated rats. However following pituitary removal, both distal jejunum and proximal ileum retained their capacity to regenerate though the magnitude of this adaptive change was much greater in the resected, pair-fed rats suggesting that hypophagia alone cannot explain the diminished adaptation to resection after hypophysectomy. By inference, pituitary hormones do influence the adaptive response to resection.