激光光凝联合玻璃体腔注气治疗玻璃体切割术后再发黄斑孔

目的 探讨激光光凝联合玻璃体腔注气治疗玻璃体切割术后再发与未愈黄斑孔的疗效。方法 应用COHERENT Omni多波长激光光凝黄斑裂孔底部的视网膜色素上皮层。随后眼内注入20％C3F80．5～0．8ml并置换出玻璃体腔液体。治疗后每天坚持俯卧位。结果 19只眼中16只眼黄斑孔愈合，成功率为84．2％，视力提高15只眼，占78．9％，未出现严重的并发症。结论 应用激光光凝联合眼内注气治疗玻璃体切割术后再发与未愈黄斑孔具有方法简单、费用低、疗效确定、大部分患者无须住院等优点。     

劳动复合方案对小鼠血浆心钠素和耐力的实验研究

昆明种小鼠56只，在两个海拔高度上（300m和5000m）各分为两个组（对照组和复合组），分别给予相应的处理因素后，检测其血浆ANP水平和游泳时间。结果表明，小鼠在海拔5000m生活48h后，其血浆ANP较海拔300m小鼠降低52．87％，而其游泳时间则增长91．59％；在两个海拔高度上，复合组血浆ANP都较对照组降低，而游泳时间都长于对照组．提示复合方案提高高原劳动能力的机理，可能与降低体内血浆ANP水平有关。     

Similarities and differences in mechanisms of cardiotoxins, melittin and other myotoxins

Myonecrosis induced in vivo by cardiotoxin, melittin, and Asp49 and Lys49 phospholipase A₂ (PLA₂) myotoxins involves rapid lysis of the sarcolemma, myofibril clumping, and hypercontraction of sarcomeres. In contrast, skeletal muscle necrosis induced by crotamine and myotoxin a is much slower, consisting of mitochondrial and sarcoplasmic reticulum swelling, myofibril degeneration, and lack of sarcolemma or transverse tubule damage. The mechanisms contributing to the myonecrosis induced by these peptides were evaluated. Two cardiotoxins and two Lys49 PLA₂ myotoxins lysed primary cultures of human skeletal muscle within 24 hr at a concentration of 0.25 μM, while melittin, crotamine, and myotoxin a, and an Asp49 PLA₂ myotoxin were non-cytolytic at concentrations up to 5.0 μM, suggesting that cytolysis is not a good measure of myotoxicity. Crotamine and the Lys49 PLA₂ myotoxin altered Ca²⁺ ion flux in human heavy sarcoplasmic reticulum by opening the ryanodine receptor. Whole-cell patch-clamp studies demonstrated that administrating crotamine intracellularly increased Na⁺ currents. Free fatty acids, liberated by activation of tissue phospholipase C or by the PLA₂ activity of the myotoxins, were monitored for crotamine, myotoxin a and a Lys49 PLA₂ myotoxin in cell cultures in which the lipids had been radiolabeled. Only the Lys49 myotoxin produced significant amounts of fatty acid in cell cultures, supporting a potential role for fatty acid production only in the mechanism of sarcolemma-destroying myotoxins. These findings, coupled with those in the literature, support a hypothesis in which the myotoxins and/or products of lipase activity (e.g. fatty acids) are acting at a site existing on both the Na⁺ channel and a protein involved in Ca²⁺ release and probably serving a modulatory function for ion regulation. Based on the similarities in mechanisms between the toxins and fatty acids, the most likely site would be a fatty acid binding site on the protein (either similar to that on fatty acid binding proteins, or an acylated cysteine residue) or in the membrane.     

Proteolytic Processing Mechanisms in the Biosynthesis of Neuroendocrine Peptides: The Subtilisin-like Proprotein Convertases

The recent discovery of a novel family of precursor processing endoproteases has greatly accelerated progress in understanding the complex mechanisms underlying the maturation of prohormones, neuropeptides, and many other precursor-derived proteins. At least six members of this family have been found thus far in mammalian species, several having alternatively spliced isoforms, and related enzymes have been identified in many invertebrates, including molluscs, insects, nematodes, and coelenterates. The proprotein convertases are all dependent on calcium for activity and all possess highly conserved subtilisin-like domains with the characteristic catalytic triad of this serine protease (ordered Asp, His, and Ser along the polypeptide chain). Two members of this family, PC2(SPC2) and PC1/PC3(SPC3), appear to play a preeminent role in neuroendocrine precursor processing. Both convertases are expressed only in the brain and in the extended neuroendocrine system, while another important family member—furin/PACE (SPC1)—is expressed more ubiquitously, in almost all tissues, and at high levels in liver. SPC2 and SPC3 exhibit acidic pH optima and other properties which enhance their activity in the acidic, calcium-enriched environment of the dense-core secretory granules of the regulated pathway in neuroendocrine cells, while furin has a neutral pH optimum and is localized predominantly to the trans Golgi network where it is retained by a C-terminal transmembrane domain. Furin processes a wide variety of precursors in the constitutive pathway, such as those of growth factors, receptors, coagulation factors, and viral glycoproteins. Recent findings on the processing of proopiomelanocortin, proinsulin, proglucagon, and several other neuroendocrine precursors by SPC2 and SPC3 are discussed, along with information on the structure, properties, evolution, developmental expression, and regulation or the convertases. An inherited defect in the fat/fat mouse which affects the processing of proinsulin, and probably also many other prohormones, due to a point mutation in carboxypeptidase E has recently been identified and has begun to provide new insights into the functional integration of the individual processing steps.     

特发性肌炎免疫机制研究及临床意义

目的探讨多发性肌炎（PM）和皮肌炎（DM）患者骨胳肌组织损伤的免疫机制及临床意义。方法应用免疫荧光一步法和免疫组化SP法分析25例PM／DM肌组织中免疫球蛋白IgG、IgM、补体C3和浸润肌组织单核细胞的分布与定位。结果PM和DM肌组织中IgG、IgM、C3的阳性率分别为60％、33．3％、20％和70％、40％、50％，以IgG为主（P＜0．05），分布于肌组织血管壁、肌膜和肌浆中，补体C3在DM血管壁的分布有统计学意义（P＜0．05）；80％PM和7O％DM肌组织有单核细胞浸润，PM以T淋巴细胞为主，Ia＋活化TS细胞占多数，主要分布于肌内衣，DM以B淋巴细胞为主，多分布在肌柬衣血管周围。结论免疫反应在PM和DM发病机理中占重要地位，PM以T细胞介导的细胞毒作用为主，DM以体液免疫特别是补体介导的血管损害为主。     

宾馆工作人员艾滋病KAP调查

目的：制订在宾馆工作人员中开展AIDS健康教育的策略。方法：调查了694名宾馆工作人员有关AIDS的KAP情况。结果：95．5％的人听说过AIDS，70．4％知道艾滋病的病原体，75．7％的确定人们可以从看上去很健康的人那里感染上艾滋病病毒，30．7％的人艾滋病知识来源于广播电视，51．4％来源于报刊杂志。接触过黄色读物和录像的人为46．4％，50．3％的人认为只要双方相爱即可发生性行为，82．9％的人认为有必要在宾馆开展艾滋病健康教育。结论：在宾馆工作人员中开展艾滋病健康教育非常必要，并应作为上岗培训内容之一。     

儿童生殖细胞瘤全脑放射治疗中自适应消除摆位累积误差新技术探讨

目的 以影像引导放射治疗(image guided-radiotherapy, IGRT)为基础探讨儿童生殖细胞瘤全脑自适应放射治疗(以下简称放疗）(adaptive radio therapy,ART）可行性,为临床全脑ART提供依据。方法 回顾性研究首都医科大学附属北京天坛医院放射治疗科20例中枢神经系统生殖细胞肿瘤(germ cell tumors, GCTs)行全脑预防性照射的放疗患者。每例患者治疗前三次及后每周行一次锥形束电子计算机断层扫描(cone beam computed tomography,CBCT),共7次。记录整个治疗过程中左右(lateral, LAT)、进出(longitudinal, LNG)、升降(vertical, VRT)方向上的摆位误差值。原计划命名为Plan_A,将因摆位误差值产生新的治疗中心点(treatment center point,ISO)回归治疗计划系统,不改变射野权重、射野分布情况下进行体积剂量计算,用Plan Sum功能相加摆位累积误差产生新计划得到Plan_B。将摆位累积误差产生的新计划用Acuros XB算法重新快速优化后用Plan Sum功能相加得到Plan_C。对比Plan_A、Plan_B、Plan_C的靶区及危及器官(organ at risk, OAR)剂量变化并用Wilcoxon配对符号秩检验证统计学差异。结果与Plan_A相比,Plan_B 均匀性指均匀性指数（homogeneity index, HI）95计划靶区（planning target volume, PTV）、 HI98 PTV为1.058 4~1.084 7。适形度指数(conformity index, CI）PTV为0.934 4。 临床靶区（clinical target volume, CTV）D_min相对偏差为－7.22%,P值为0.000 7。OAR相对偏差为－0.1%~9.8%。与Plan_ A相比,Plan_ C的HI95 PTV、 HI98 PTV为1.056 9~1.078 8。CI PTV为0.936 5。CTV D_min相对偏差为－1.69%,P值为0.545 9。OAR相对偏差为－0.15%~3.40%。结论儿童生殖细胞瘤全脑放疗摆位累计误差对靶区及危及器官剂量差异有统计学意义,摆位累计误差导致靶区均匀性及适形度变差,CTV的D_min 变化超过5%,OAR受量增高。ART再计划可以让靶区均匀性和适形度及危及器官受量接近原计划。同时Plan_B虽然存在相对偏差,但是危及器官的绝对剂量在合理范围内。     

AO肩锁钢板钩治疗重型肩锁关节脱位

目的评估AO肩锁钢板钩治疗重型肩锁关节脱位的手术疗效.方法回顾性分析两年来27例手术病人的手术治疗和疗效.结果手术方法符合生理结构,手术时间平均30分钟,内固定牢靠.根据Murley和Constant[1]评分,优良率94%.结论 AO肩锁钢板钩治疗重型肩锁关节脱位,手术方法简单,疗效可靠,允许病人术后早期功能锻炼.