降钙素基因相关肽抑制血管平滑肌细胞能量代谢的AMP激活蛋白激酶信号通路

目的观察降钙素基因相关肽对血管紧张素Ⅱ诱导血管平滑肌细胞增殖过程中能量代谢的影响及机制,探索细胞外信号调节激酶和AMP激活蛋白激酶相关信号蛋白在该作用中的地位。方法组织贴块法体外培养SD大鼠胸主动脉血管平滑肌细胞,取第3～10代用于实验。分别用降钙素基因相关肽或/和血管紧张素Ⅱ处理细胞。MTT法及细胞计数法观察降钙素基因相关肽对血管紧张素Ⅱ诱导大鼠血管平滑肌细胞增殖的影响;詹纳斯绿B染色观察细胞线粒体形态及体积;ATP检测试剂盒检测细胞内ATP水平;Western Blotting检测细胞磷酸化AMP激活蛋白激酶的表达。结果降钙素基因相关肽预处理能降低血管紧张素Ⅱ诱导的大鼠血管平滑肌细胞的增殖(P<0.05),同时拮抗血管紧张素Ⅱ引起细胞内线粒体肿胀、ATP水平升高,在此过程中伴随细胞内磷酸化AMP激活蛋白激酶表达下调(P<0.05);降钙素基因相关肽受体拮抗剂CGRP8-37能拮抗降钙素基因相关肽对血管紧张素Ⅱ促增殖和促代谢的抑制作用(P<0.05);细胞外信号调节激酶抑制剂PD98059能部分拮抗降钙素基因相关肽对磷酸化AMP激活蛋白激酶的抑制作用(P<0.05)。结论降钙素基因相关肽能显著抑制血管紧张素Ⅱ诱导大鼠血管平滑肌细胞增殖过程中的能量代谢,其细胞内信号通路可能涉及到降钙素基因相关肽/降钙素基因相关肽1型受体-丝裂原细胞外激酶/细胞外信号调节激酶-磷酸化AMP激活蛋白激酶信息传递链。     

降钙素基因相关肽介导内皮祖细胞抑制血管平滑肌细胞的增殖及其分子机制

目的：探讨内皮祖细胞条件培养基抑制血管紧张素Ⅱ诱导的血管平滑肌细胞增殖的分子机制。方法：制备早期内皮祖细胞条件培养基,经降钙素基因相关肽抗体预处理内皮祖细胞条件培养基或特异性阻断剂阻断内皮祖细胞降钙素基因相关肽受体后,采用免疫印迹、逆转录聚合酶链反应、间接免疫荧光观察内皮祖细胞条件培养基对血管紧张素Ⅱ所致血管平滑肌细胞MAPK、NF-κB信号转导通路和原癌基因c-myc、c-fos表达的影响。结果：降钙素基因相关肽阻断后,早期内皮祖细胞条件培养基对血管紧张素Ⅱ诱导的血管平滑肌细胞MAPK(P38、JNK)、核因子-κB(亚单位P65)信号转导通路的活化以及原癌基因c-myc、c-fos表达的抑制能力较对照组明显降低。结论：内皮祖细胞通过旁分泌降钙素基因相关肽抑制血管紧张素Ⅱ诱导的血管平滑肌细胞增殖,其机制可能与其抑制血管平滑肌细胞MAPK(P38、JNK)、核因子-κB信号转导通路的活化以及原癌基因c-myc、c-fos表达有关。     

降钙素基因相关肽介导内皮祖细胞抑制血管紧张素Ⅱ诱导的血管平滑肌细胞表型转化

目的初步探讨内皮祖细胞抑制血管紧张素Ⅱ诱导的血管平滑肌细胞表型转化的分子机制。方法从人脐带血分离、培养、诱导内皮祖细胞分化并鉴定,制备早期内皮祖细胞条件培养基,酶联免疫吸附试验检测降钙素基因相关肽分泌情况。经降钙素基因相关肽抗体预处理内皮祖细胞条件培养基或阻断内皮祖细胞降钙素基因相关肽受体后,采用逆转录聚合酶链反应和免疫印迹观察内皮祖细胞条件培养基对血管紧张素Ⅱ诱导的血管平滑肌细胞收缩表型标志基因平滑肌α-肌动蛋白以及合成表型标志基因骨桥蛋白表达变化的作用;进一步观察内皮祖细胞条件培养基对血管紧张素Ⅱ诱导的血管平滑肌细胞增殖信号通路(ERK、核因子κB通路)的作用。结果早期内皮祖细胞能够分泌较高浓度的降钙素基因相关肽,并且较晚期内皮祖细胞及脐静脉内皮祖细胞高;内皮祖细胞条件培养基处理能明显抑制血管平滑肌细胞表型转化;阻断降钙素基因相关肽作用后,内皮祖细胞条件培养基对血管紧张素Ⅱ诱导的血管平滑肌细胞表型转化的抑制能力明显降低;同时内皮祖细胞条件培养基能够明显抑制血管紧张素Ⅱ诱导的ERK以及核因子κB通路的活化;阻断降钙素基因相关肽作用后,内皮祖细胞条件培养基对血管紧张素Ⅱ诱导的ERK、核因子κB信号通路活化的抑制能力明显降低。结论降钙素基因相关肽参与介导内皮祖细胞抑制血管紧张素Ⅱ诱导的血管平滑肌细胞的表型转化,其机制可能与其抑制血管平滑肌细胞ERK、核因子κB信号通路活化有关。     

小凹蛋白1-小凹在血管紧张素Ⅱ诱导血管平滑肌细胞增殖信号转导通路中的作用

为观察小凹蛋白1和小凹对血管紧张素Ⅱ诱导血管平滑肌细胞增殖信号转导通路的调控作用，本文用Westem Blot、小凹蛋白1反义寡核苷酸技术及氚标胸腺嘧啶脱氧核苷掺入法观察到血管紧张素Ⅱ刺激细胞外信号调节激酶活化和血管平滑肌细胞增殖，同时抑制小凹蛋白1表达。小凹蛋白1反义寡核苷酸处理可增强血管紧张素Ⅱ激活细胞外信号调节激酶和刺激血管平滑肌细胞增殖的作用。细胞外信号调节激酶抑制剂PD98059和小凹结构抑制剂制霉菌素均可阻断血管紧张素Ⅱ所致细胞外信号调节激酶的活化和小凹蛋白1表达下降和细胞增殖。     

G蛋白抑制肽对血管紧张素Ⅱ诱导的大鼠血管平滑肌细胞增殖的影响

目的 观察G蛋白抑制肽对血管紧张素Ⅱ诱导的大鼠血管平滑肌细胞增殖的影响. 方法贴块法行大鼠胸主动脉血管平滑肌细胞分离培养,α-SM-actin 免疫细胞化学染色鉴定.以血管紧张素Ⅱ为刺激因子,并加入不同浓度的G蛋白抑制肽27,分别利用MTT法、Bradford法和直接计数法检测细胞增殖活性、细胞总蛋白含量、细胞数量的变化. 结果血管紧张素Ⅱ组血管平滑肌细胞增殖活性（吸光度）、细胞总蛋白含量和细胞数量明显高于对照组（P＜0.05或P＜0.01）,而加入浓度≥10 μg/L 的G蛋白抑制肽27后,血管平滑肌细胞增殖活性、细胞总蛋白含量和细胞数量均较血管紧张素Ⅱ组明显降低,差异有显著性（P＜0.05或P＜0.01）. 结论血管紧张素Ⅱ对血管平滑肌细胞的促增殖作用能被G蛋白抑制肽27所拮抗.     

血管紧张素Ⅱ下调肥厚心肌细胞缝隙连接蛋白Cx43的表达

目的研究血管紧张素Ⅱ诱导心肌细胞肥大后连接蛋白43（Cx43）表达的变化及与细胞周期分布的关系。方法分离培养大鼠心肌细胞，用血管紧张素Ⅱ诱导心肌细胞肥大，72h后用RT-PCR，Western-blot和免疫荧光方法观察心肌细胞Cx43基因和蛋白表达，用流式细胞仪测定法观察心肌细胞周期分布变化以及与Cx43表达量的关系。结果血管紧张素Ⅱ处理后的心肌细胞表现细胞肥大且细胞活力增强，S期、G2-M期细胞百分比增加，细胞内G2-M（二倍体）DNA含量降低，Cx43蛋白表达明显低于正常对照组，呈浓度依赖性下调，Cx43mRNA表达水平显著下调，Cx43蛋白表达下调与细胞周期分布的改变相关。结论血管紧张素Ⅱ诱导心肌细胞肥大后Cx43基因及Cx43蛋白表达出现浓度依赖性下调，这一改变与心肌肥大过程中的细胞周期变化有关，提示血管紧张素Ⅱ可能通过调控Cx43基因的表达而参与缝隙连接重构过程，而Cx43表达的变化可能与心肌肥大的机制有关。     

血管紧张素Ⅱ下调肥厚心肌细胞缝隙连接蛋白Cx43的表达

目的 研究血管紧张素Ⅱ诱导心肌细胞肥大后连接蛋白43(Cx43)表达的变化及与细胞周期分布的关系.方法 分离培养大鼠心肌细胞,用血管紧张素Ⅱ诱导心肌细胞肥大,72 h后用RT-PCR,Western-blot和免疫荧光方法 观察心肌细胞Cx43基因和蛋白表达,用流式细胞仪测定法观察心肌细胞周期分布变化以及与Cx43表达量的关系.结果 血管紧张素Ⅱ处理后的心肌细胞表现细胞肥大且细胞活力增强,S期、G2-M期细胞百分比增加,细胞内G2-M(二倍体)DNA含量降低,Cx43蛋白表达明显低于正常对照组,呈浓度依赖性下调,Cx43 mRNA表达水平显著下调,Cx43蛋白表达下调与细胞周期分布的改变相关.结论 血管紧张素Ⅱ诱导心肌细胞肥大后Cx43基因及Cx43蛋白表达出现浓度依赖性下调,这一改变与心肌肥大过程中的细胞周期变化有关,提示血管紧张素Ⅱ可能通过调控Cx43基因的表达而参与缝隙连接重构过程,而Cx43表达的变化可能与心肌肥大的机制有关.     

萘哌地尔衍生物YMⅢ对血管紧张素Ⅱ诱导大鼠胸主动脉平滑肌细胞增殖的抑制作用

目的 研究萘哌地尔衍生物YMⅢ对血管紧张素Ⅱ诱导Wistar大鼠和自发性高血压大鼠胸主动脉平滑肌细胞增殖的抑制作用及机制.方法 将Wistar大鼠和自发性高血压大鼠胸主动脉平滑肌细胞进行体外培养,采用四甲基偶氮唑盐比色法检测YMⅢ对胸主动脉平滑肌细胞和血管紧张素Ⅱ诱导胸主动脉平滑肌细胞增殖的影响;用实时逆转录聚合酶链反应技术检测血管紧张素原、c-myc mRNA表达.结果 未经血管紧张素Ⅱ处理的胸主动脉平滑肌细胞.0.1 μmol/L YMⅢ能抑制Wistar大鼠和自发性高血压大鼠胸主动脉平滑肌细胞增殖;YMⅢ(0.01、0.05、0.1 μmol/L)能呈浓度依赖性抑制血管紧张素Ⅱ所致Wistar大鼠和自发性高血压大鼠胸主动脉平滑肌细胞的增殖;YMⅢ(0.05～0.1 μmol/L)作用能使血管紧张素Ⅱ所致Wistar大鼠血管紧张素原、c-myc mRNA表达水平下调,而各浓度YMⅢ均能下调血管紧张素Ⅱ所致自发性高血压大鼠胸主动脉平滑肌细胞的血管紧张素原、c-myc mRNA表达.结论 YMⅢ明显抑制血管紧张素Ⅱ诱导大鼠胸主动脉平滑肌细胞的增殖,且抑制增殖作用在自发性高血压大鼠比在Wistar大鼠明显,其作用机制可能与下调血管紧张素原、c-myc mRNA的表达有关.     

ADAM17调控CGRP对血管紧张素Ⅱ诱导的血管平滑肌细胞增殖的抑制效应

目的阐明肿瘤坏死因子α转化酶(ADAM17)调控降钙素基因相关肽(CGRP)的抗血管平滑肌细胞(VSMC)增殖效应。方法以大鼠源性胸主动脉平滑肌细胞株(A10VSMC)为研究对象,采用RNA干扰抑制ADAM17表达;采用蛋白质免疫印迹和实时定量PCR检测蛋白和mRNA表达水平;采用噻唑蓝比色法评估细胞活性。结果 CGRP显著抑制血管紧张素Ⅱ介导的VSMC增殖。血管紧张素Ⅱ刺激24 h后,VSMC中ADAM17表达显著增加。CGRP预处理30 min能显著降低VSMC中ADAM17表达,而CGRP受体拮抗剂CGRP8-37可抑制或逆转上述效应。ADAM17 RNA干扰可显著抑制血管紧张素Ⅱ介导的VSMC增殖。结论降低ADAM17表达可能是CGRP抑制血管紧张素Ⅱ介导的VSMC增殖效应的机制。     

蜂胶水提液对人脐动脉平滑肌细胞增殖作用的影响

目的 观察蜂胶水提液对血管紧张素Ⅱ诱导的人脐动脉平滑肌细胞增殖作用的影响.方法 贴块法培养人脐动脉平滑肌细胞,用50、100和200 mg/L蜂胶水提液进行干预.细胞计数法检测人脐动脉平滑肌细胞数量;流式细胞仪检测细胞周期;免疫细胞化学法观察增殖细胞核抗原;分光光度计检测培养液中超氧化物歧化酶及丙二醛的含量;用脱氧核糖核苷酸末端转移酶介导的缺口末端标记技术检测细胞凋亡.结果 100 mg/L和200mg/L的蜂胶水提液能减少血管紧张素Ⅱ对细胞的增殖作用,增加G0/G1期细胞的百分比,降低增殖细胞核抗原阳性率,蜂胶各浓度组总超氧化物歧化酶活力升高,而丙二醛含量降低,凋亡指数降低(P<0.01).结论 一定浓度的蜂胶水提液能抑制血管紧张素Ⅱ诱导的人脐动脉平滑肌细胞增殖;机制可能与蜂胶水提液影响细胞增殖周期、抑制增殖细胞核抗原的表达、提高人脐动脉平滑肌细胞抗氧化能力有关.     

Research and Evaluation of the Influence of the Construction of the Gate and the Influence of the Piston Velocity on the Distribution of Gases into the Volume of the Casting

Distribution of gasses to the cast volume and volume of pores can be maintained within the acceptable limits by means of correct setting of technological parameters of casting and by selection of suitable structure and gating system arrangement. The main idea of this paper solves the issue of suitability of die casting adjustment—i.e., change of technological parameters or change of structural solution of the gating system—with regards to inner soundness of casts produced in die casting process. Parameters which were compared included height of a gate and velocity of a piston. The melt velocity in the gate was used as a correlating factor between the gate height and piston velocity. The evaluated parameter was gas entrapment in the cast at the end of the filling phase of die casting cycle and at the same time percentage of porosity in the samples taken from the main runner. On the basis of the performed experiments it was proved that the change of technological parameters, particularly of pressing velocity of the piston, directly influences distribution of gasses to the cast volume.     

县级以下综合医疗机构医务人员对现代结控知识的认识现状调查

目的本文旨在了解医务人员现代结控知识掌握的现状及培训效果?方法于培训前后进行问卷调查,内容包括:病例发现?结核病诊断及化疗?结果培训前疫情报告和转诊,回答正确者占75.2%?71.7%;对临床表现?查痰和诊断依据,回答正确者占83.5%?42.5%?40.8%;抗痨药物?用药方法?化疗原则?短化方案?短化疗程?治愈标准六项,回答正确者占58%?14.4%?20.8%?9.2%?17%?24.3%?培训后再次调查发现,90%以上医务人员对现代结控基本知识已掌握?结论各级医务人员现代结控知识是很贫乏的,因此,对其进行系统培训是极为必要的,此项工作省时?省力?投入少,可收到事半功倍的效果。     

Preservation of the pylorus and resection of the head of the pancreas

The historical evolution of the pylorus-preservation resection of the head of the pancreas is traced from the first resections early in this century to relative standardization of the operation, to a lowering of the operative mortality, and to an interest in improving nutritional status after resection. There are many theoretical advantages for the function of the upper gastrointestinal tract after pylorus and gastric preservation, such as maintenance of gastric capacitance and equilibration of osmotic pressure in gastric digestants, foodstuff digestion and absorption, and bowel motility. After the pylorus-preserving resection, gastric emptying is normal, pyloric function to prevent duodenal reflux is often normal, and gastric acids and serum levels of duodenal hormones are at normal levels, whereas after standard pancreatoduodenectomy, all of these are often abnormal. No prospective blinded studies have been published comparing nutritional values after the two operative procedures, but evidence is presented of a satisfactory result with regard to gastric capacitance, body weight gain, and lack of postgastrectomy symptoms. An undoubted advantage of the pylorus-preserving feature is a simplification of the operation. These gains are achieved without increase in operative mortality, without increase in the incidence of jejunal ulcer, and without theoretical or actual decrease in value of the procedure as a cancer operation, except in patients with duodenal carcinoma proximal to the ampulla of Vater.     

Preservation of the pylorus in resection of the head of the pancreas

Pylorus preservation has been advocated to decrease the morbidity associated with the classical or standard pancreaticoduodenectomy. The proposed advantages are decreased incidence of peptic ulceration, dumping syndrome, and nutritional problems. However, after an initial period of enthusiasm for the procedure, it is now being found that marginal ulceration at the duodenojejunal anastomosis is encountered with increasing frequency. Delay in gastric emptying occurs frequently, with an overall incidence of 30%. With the availability of better pancreatic enzyme supplements, the current incidence of nutritional problems and weight loss after the standard Whipple procedure is unknown. Whether there is a difference in long-term survival after the two procedures performed for adenocarcinoma of the head of the pancreas is still debatable. A controlled trial is needed to answer many of these questions, and pylorus-preserving pancreaticoduodenectomy should be used cautiously until further data become available.     

Studies of the vascular anatomy of the mesorectum support the concept of the total mesorectal excision

The relation between the mesorectal vessels and the mesorectal fascia needs to be clarified, as a total mesorectal excision (TME) probably derives its advantage from the fact that the visceral or mesorectal fascia can be regarded as a “tumor-tight packaging” and does not contain anatomically preformed perforations. The purpose of this investigation was to study both rectal arterial supply and vascular distribution pattern within the mesorectum. The arterial supply to the rectum was studied with the injection technique in 12 porcine and 28 human TME specimens. We stain-marked 12 porcine and 15 human specimens. Thirteen human specimens were angiographed after filling their arterial bed with a radio-opaque substance. The superior rectal artery is the main rectal artery. Terminal branches extend downwards and forward around the rectum to the level of the levator and muscle. The superior rectal artery and vein were found to be enclosed in a fibrous sheath. The main mesorectal vessels do not penetrate the mesorectal fascia. This study supports the hypothesis of bilateral somatic and one central visceral compartment in the pelvis and implies the absolute necessity of tumor removal within an intact mesorectal fascia. Received: 15 August 2000 / Accepted in revised form: 1 October 2000