Acute Moderate Hypoxia in Conscious Rabbits: Effect on Hepatic Cytochrome P450 and on Reactive Oxygen Species

This study aimed to document whether acute moderate hypoxia modifies the amount and activity of hepatic cytochrome P450 and in addition, induces changes in the production or the ability to neutralize oxygen reactive species (ORS). Rabbits were exposed to a low partial pressure of oxygen (12%) for 8 or 24 h, killed, and the amount and activity of cytochrome P450, lipid peroxidation, microsomal chemiluminescence and enzymatic scavenger activity were assessed in the liver. After 8 h of hypoxia, total amount but not the activity of cytochrome P450 was decreased, although after 24 h of hypoxia, both the amount and the activity of cytochrome P450 were decreased. Hypoxia for 8 h increased the activity of glutathione peroxidase. However, after 24 h of hypoxia, lipid peroxidation, microsomal chemiluminescence and superoxide dismutase activity were increased, while hepatic glutathione and glutathione peroxidase activity were reduced, modifications that suggest an enhanced presence of ORS. In in-vitro studies, an ORS generating system reduced the activity of cytochrome P450 and enhanced lipid peroxidation of hepatic microsomal membranes, supporting the view that ORS can impair cytochrome P450. The results of the present study show that hypoxia induces changes in the amount and activity of cytochrome P450, as well as in the production or the ability to neutralize ORS, and that these changes are time-dependent.     

微处理器控制的植入式心脏起搏器专用电路研制

介绍了一种基于微处理器的植入式心脏起搏器专用电路设计。该设计采用的技术路线和国外现有技术方案不同，它采用通用微处理器设计，降低了投资风险，缩短了开发周期．特别适合于我国这样的发展中国家。     

不同脑缺血和再灌流过程中大鼠脑组织NO含量的动态变化

采用线栓法制成大鼠大脑中动脉梗塞 ( MCAO)模型 ,依 Hb O2 - NO法测定持续性脑缺血和缺血 /再灌流脑组织内 NO含量的变化 ,以探讨不同脑缺血和再灌流过程中 NO的变化规律及其意义。结果 :缺血 3小时受损脑组织 NO水平即增高 ,再灌流后 NO逐步升高 ,而持续性缺血状态下 NO则表现降低后再升高的变化。虽然两组 NO在 7天时均有明显降低 ,但仍高于缺血前水平。认为持续性脑缺血和缺血 /再灌流情况下 NO的变化规律有所不同 ,与缺血脑组织的缺氧及产生 NO所需底物供应缺乏有关 ,且可能与脑组织的损害密切相关     

Role of EDRF in the Regulation of Shear Rate in Large Coronary Arteries in Conscious Dogs

To determine whether dilation of large coronary arteries normalizes shear during increased flow following brief occlusion, six dogs were instrumented to measure aortic and left ventricular pressures, left circumflex coronary artery external diameter, and coronary blood flow. The coronary artery was occluded for 15 or 30 s. Data were obtained before and after blockade of EDRF synthesis with nitro-L-arginine. Internal coronary artery diameter and wall shear were calculated on a moment-to-moment basis and the area under the flow curve was measured. Peak flow and shear rate were unaffected by NLA or by the occlusion duration. Flow curve area increased with the duration of occlusion. Internal and external diameters increased significantly for 15 s occlusions before NLA (by 4 ± 1% in external diameter and by 11 ± 4% in internal diameter) and for 30 s occlusions before NLA (by 5 ± 1% in external diameter and by 14 ± 5% in internal diameter) but not after NLA. Adenosine infusions of 0.05, 0.10, 0.50, and 1.0 μmol/kg/min were also used to dilate the coronary arteries. With each infusion, flow, shear and diameter were allowed to reach steady state. Steady state shear was reduced only slightly and did not approach the baseline state. We conclude that increased shear rate causes an increase in coronary artery diameter which is EDRF dependent. Increased coronary artery diameter during reactive hyperemia and adenosine infusions did not normalize wall shear.     

健侧颈7移位治疗臂丛神经根性撕脱伤最佳时间选择的实验研究

健侧颈７移位治疗臂丛神经根性撕脱伤手术分第一阶段（健侧颈７移位到移植神经），第二阶段（移植神经另一端移植修复患侧神经），二次手术间隔多少时间才能获得最好的神经再生？选用ＳＤ大鼠及健侧颈７移位的实验模型，按二次手术间隔时间的不同（０、１、２、３、４、８、１６周）分成７组，在第二次术后１２周，进行电生理测定肌张力恢复率及组织切片的形态学观察，结果证实二次手术最佳间隔时间为４～８周．此结果可提供临床参考．     

生长激素在肝硬变门脉高压低蛋白血症手术前的应用研究

目的：研究生长激素（rhGH)对肝硬变门脉高压低蛋白血症患者手术前的治疗价值。方法：肝硬变门脉高压抑行脾切除、门奇静脉断流手术患者60例，Child分级B级，随机分为rhGH治疗组30例，对照组30例。rhGH组术前5d每天皮下注射rhGH 4IU，对照组给予安慰剂生理盐水。两组术前均行相同肠外营养支持。测定治疗前、治疗后3d、4d、5d血浆白蛋白、球蛋白、前白蛋白及空腹血糖。结果：rhGH组治疗后3d前白蛋白较治疗前及对照组明显升高（P＜0．05），治疗后4d、5d仍维持较高水平；治疗后5d白蛋白较治疗前及对照组明显升高（P＜0．05）。rhGH组患者一般情况改善，生活质量提高。对照组白蛋白、前白蛋白无明显变化。两组空腹血糖、球蛋白无明显改变。结论：rhGH联合肠外营养支持对纪正肝硬变门脉高压低蛋白血症患者术前低蛋白状态，改善生活质量有良好疗效，由于rhGH起效慢，应早期、足量、足疗程应用。     

Correlation between Cyclin A Gene Expression in Adult Patients with Acute Leukemia and Drug Resistance

Adultacuteleukemia (AL)isoneofthemostcommonmalignanttumorsofhematology .Withtherecentprogressinchemotherapyandsupportivether apy ,theremissionandsurvivalrateinALhavebeenmarkedlyimproved .However ,drugresistanceandrelapsearestillimportantfactorsaffectinglongsur vivalofthese patients .Theabnormalregulationofcellcycleisanotherfactorthatcannotbeignoredex ceptformultipledrugresistance (MDR) .WedetectcyclinA ,multidrugresistantgene (mdrl) ,topoiso meraseⅡα(TopⅡα)andbcl 2inadultpatientswithA…     

乌苯美司体外对人单核细胞功能的活化作用

观察了国产乌苯美司（乌比美克）体外对人单核细胞功能的影响：①０．０１￣１００μｇ／ｍｌ乌苯美司能直接诱导人单核细胞生成ＩＬ－１；②经０．１μｇ／ｍｌ乌苯美司作用４ｈ后，人单核细胞即开始分泌ＩＬ－１，２４ｈ达到高峰，以后逐渐下降；③经１０￣１００μｇ／ｍｌ乌苯美司预处理，单核细胞可促进ＮＫ细胞活性，而经０．０１￣０．１μｇ／ｍｌ乌苯美司处理，单核细胞则抑制ＮＫ细胞活性。     

从北京入境的中国籍旅行者死亡案例分析

目的 国际旅行者的健康和在旅行目的 地死亡原因应予以极大关注.通过对中国籍旅行者死亡原因的分析、致死危险性因素的评估,以便有针对性地对国际旅行者提供卫生保健咨询.方法 本文分析了1998年到2002年期间经北京口岸入境的在国外死亡的中国籍旅行者.对每例死亡的地理分布、死亡原因等进行统计.结果 1998年到2002年期间经北京口岸入境的在国外死亡的中国籍旅行者共64例.死亡发生在利比亚、阿拉伯联合酋长国、巴基斯坦、新加坡和巴林等36个国家和地区.心血管疾病、交通事故、工伤致死及意外伤害为主要的死亡原因.结论 根据旅行目的地国家不同、旅行目的 不同,针对心血管疾病、工伤、意外伤害及传染病等危险性提供旅行卫生保健咨询.     

真皮下血管网皮瓣的过氧化脂质测定

对12只豚鼠背部随意型真皮下血管网皮瓣的过氧化脂质含量进行了动态观测.结果表明,过氧化脂质的含量与皮瓣损伤程度呈同步变化;与皮瓣血运重建的时间密切相关.氧自由基对皮瓣组织的损伤主要发生在移植后1～5天.