霉酚酸酯对2型糖尿病大鼠肾组织的保护作用

目的:观察霉酚酸酯(MMF)对2型糖尿病大鼠肾组织中神经生长因子(NGF)的影响.方法:应用高糖高脂饮食加小剂量链脲佐菌素(STZ)制备2型糖尿病大鼠模型,然后分别用胰岛素、MMF及二者联合干预治疗.采用免疫组织化学技术检测各组肾小球中NGF及单核/巨噬细胞(CD68)的表达水平.结果:(1)高糖高脂饮食 小量STZ后,大鼠血糖升高,且血胰岛素水平不低.继续喂养6周后大鼠肾重/体重、内生肌酐清除率(Ccr)、尿白蛋白排泄率(UAE)等指标较正常组明显升高;(2)糖尿病组大鼠肾组织中NGF、CD68表达较正常组明显增加.治疗6周后,MMF 胰岛素组NGF表达水平显著降低,单核/巨噬细胞浸润减轻,肾功能指标及组织病理学损害明显改善.结论:(1)糖尿病模型建立后6周,已出现糖尿病肾病早期改变;(2)2型糖尿病大鼠肾组织中NGF过量表达,MMF的肾脏保护作用可能与减少肾组织中NGF表达,减轻单核/巨噬细胞的浸润有关;(3)同时应用MMF和胰岛素能增强对2型糖尿病大鼠肾脏的保护作用,这可能与MMF抗炎和胰岛素降血糖双重保护作用有关.     

霉酚酸酯对糖尿病大鼠肾间质细胞浸润及肾组织ICAM-1和MCP-1 mRNA表达的影响

炎症反应是糖尿病肾病（DN）发生的重要环节，细胞间黏附分子（ICAM）和单核细胞趋化因子（MCP）表达增加是导致单核细胞及巨噬细胞浸润肾组织的两个重要因素。近年来发现霉酚酸酯（MMF）有抗炎作用，所以在理论上可以用于包含糖尿病肾病在内的一些非移植性疾病的治疗。本研究的目的主要在于探讨MMF对糖尿病大鼠肾脏ICAM-1和MCP-1m RNA表达的影响及其对肾脏的保护作用。     

霉酚酸酯对糖尿病大鼠肾组织单核细胞趋化蛋白-1与细胞间黏附分子-1表达的影响

糖尿病肾病(DN)肾内单核细胞趋化蛋白-1(MCP-1)、细胞间黏附分子-1(ICAM-1)表达上调,单核/巨噬细胞浸润等炎症机制越来越受到重视犤1犦。本研究探讨霉酚酸酯(MMF)对糖尿病(DM)肾组织MCP-1、ED-1、ICAM-1表达的影响,旨在为DN的抗炎治疗提供实验依据。一、材料和方法1.糖尿病模型建立及分组:30只雄性昆明种SD大鼠(安医大实验动物中心提供),行右肾切除术和腹腔注射单剂量STZ65mg/kg。随机分3组:对照组(C);模型组(DM);MMF给药组(DM MMF),每组10只。MMF10mg·kg-1·d-1灌胃。整个实验期间不用胰岛素。2.指标检测:术后8周末测尿…     

神经生长因子在2型糖尿病大鼠肾组织中的表达及意义

目的建立2型糖尿病大鼠模型,观察神经生长因子（NGF）在该大鼠肾组织中的表达及单核／巨噬细胞（CD68）的浸润情况。方法应用高糖高脂饮食加小剂量链脲佐菌素（STZ）制备2型糖尿病大鼠模型。采用免疫组化技术检测各组肾组织中NGF及CD68的表达水平。结果①高糖高脂可成功诱导胰岛素抵抗,小量STZ可使血糖升高,达到糖尿病标准。2型糖尿病大鼠模型制备成功后,继续喂养6周,血肌酐（SCr）、尿素氮（BUN）、内生肌酐清除率（Ccr）、尿白蛋白排泄率（UAE）、肾重／体重增加等特征,肾组织出现明显基底膜增厚、系膜区扩张等病理学改变。②糖尿病组大鼠肾组织中NGF、CD68表达较正常组明显增加。且NGF、CD68二者数量呈正相关。结论①糖尿病模型建立后6周,已出现糖尿病肾病早期改变。②NGF可能通过介导炎症反应参与糖尿病肾脏损害过程,且此炎症反应至少部分与单核／巨噬细胞的增殖活化及浸润有关。     

霉酚酸酯对糖尿病大鼠肾组织RANTES与ED-1表达的影响

目的：建立链脲佐菌素（STZ）诱导的糖尿病大鼠模型并用霉酚酸酯（MMF）干预，动态观察细胞因子（RANTEs）、单核／巨噬细胞表面特异性标志抗原（ED-1）、Ⅳ型胶原（Col Ⅳ）在肾组织中的表达，探讨MMF能否通过抑制肾组织炎症反应达到保护肾脏的作用。方法：36只雄性SD大鼠随机分为正常对照组、糖尿病模型组和MMF治疗组，于实验第4周、14周末每组分别处死6只大鼠，处死前留取24h尿进行24h尿蛋白定量，处死后免疫组织化学染色观察RANTES、ED-1、Col Ⅳ在肾组织中的表达。结果：（1）正常肾组织RANTES有少量表达，模型组的表达均显著增高，MMF组各时间点与相应模型组比较均显著降低；（2）正常肾组织ED-1有少量表达，模型组的表达均显著增高，MMF组各时间点与相应模型组比均显著降低。结论：MMF可能是通过下调RANTES在肾组织中的表达、减少单核／巨噬细胞在肾组织中的浸润．在旱期抑制肾组织炎症反应．进而对肾脏具有一定的保护作用．     

p38丝裂原活化蛋白激酶介导抵抗素调节高糖刺激下人肾小球系膜细胞增殖的作用

目的 观察巨噬细胞因子抵抗素过度表达对高糖刺激作用下人肾小球系膜细胞p38丝裂原活化蛋白激酶（MAPK）信号通路的影响，探讨抵抗素调控肾小球系膜细胞增殖及细胞外基质积聚的作用机制。 方法 通过转染携带野生型抵抗素基因的腺病毒载体 （Ad-resistin）构建过度表达抵抗素的人巨噬细胞模型，并与高糖刺激后的人肾小球系膜细胞共培养。3H-氚标胸腺嘧啶掺入法检测肾小球系膜细胞增殖。免疫细胞化学法检测系膜细胞激活蛋白1（AP-1）的表达。免疫荧光检测细胞外基质层粘连蛋白（LN）的表达。Western印迹检测系膜细胞内p38MAPK、转化生长因子(TGF)β1的表达并测定Smad2的磷酸化水平。 结果 Ad-resistin转染后，人巨噬细胞抵抗素 mRNA水平及蛋白表达均显著升高（P < 0.01）。与对照组比较，与过度表达抵抗素的人巨噬细胞共培养后，人肾小球系膜细胞p38MAPK、TGF-β1的蛋白表达显著增强；细胞内Smad2的磷酸化水平显著升高（P < 0.05）；肾小球系膜细胞出现明显的增殖（P < 0.01）；细胞外基质的合成增多（P < 0.05）。 结论 巨噬细胞因子抵抗素的过度表达可能通过p38MAPK信号通路，促进高糖刺激作用下肾小球系膜细胞的增殖及细胞外基质的异常积聚。     

氧化低密度脂蛋白刺激人肾小球系膜细胞产生单核细胞趋化蛋白-1由核因子-кB活化调控

目的 研究核因子-кB（NF-кB）在氧化低密度脂蛋白（Ox-LDL)诱导的体外培养的人肾小球系膜细胞表达单核/巨噬细胞趋化蛋白-1（MCP-1）中的作用。方法 采用凝胶迁移率变动分析检测NF-кB的DNA结合活性变化。以免疫组织化学观测细胞内p65的核转位，用细胞ELISA法检测细胞内MCP-1及IкBα蛋白含量变化。结果 不同浓度（10、25、50、100μg/ml)Ox-LDL刺激肾小球系膜细胞均可引起细胞NF-кB的DNA结合活性增强，IкBα蛋白表达下降以及MCP-1蛋白表达增强，以50μg/ml刺激1hNF-кB活化及IкBα表达减弱最明显，作用24hMCP-1表达水平最高，NF-кB活化的同时伴有p65核转位，上述效应可被NF-к特异性抑制剂吡咯二硫氨基甲酸酯（PDTC）所抑制。结论 Ox-LDL刺激人肾小球系膜细胞产生MCP-1是由NF-кB调控，NF-кB参与了脂质肾损害的发病过程。     

霉酚酸酯联合激素对弥漫增生性狼疮肾炎活动性及慢性病变的影响及其机制研究

目的 比较霉酚酸酯（MMF）联合糖皮质激素治疗弥漫增生性狼疮肾炎前后肾组织的活动性和慢性病变的变化并探讨其机制，方法 9例弥漫增生性狼疮肾炎患者在MMF和糖皮质激素治疗后6-7个月接受了重复肾活检，应用天狼星红行胶原染色，T细胞，单核/巨噬细胞，增殖细胞、骨桥蛋白（OPN）、纤连蛋白（FN）、α-平滑肌肌动蛋白（α-SMA）及TGF-β1应用SP法行免疫组织化学染色，计数细胞及应用图像分析对染色行定量评估，对组织病理表现行活动指数（AI）和慢性指数（CI）评分，观察上述指标在治疗前后的变化。分析其间的相关性，结果 （1）治疗后AI下降，小球及小管间质浸润的T细胞，单核/巨噬细胞减少，小球及小管间质细胞的增殖率降低；OPN表达减少并与小管间质的单核/巨噬细胞数正相关。（2）治疗后CI变化不显著，FN在小球及小管间质的面积比，胶原在小管间质的面积比及α-SMA、TGF-β1的表达在治疗前后差异无显著性意义。（3）治疗后间质的T细胞数与胶原在小管间质的面积比正相关，单核/巨噬细胞数与胶原，FN、α-SMA在小管间质面积比正相关，结论 MMF联合糖皮质激素治疗弥漫增生性狼疮肾炎可以通过下调黏附分子减少单核巨噬细胞和淋巴细胞浸润，抑制细胞增殖，从而减轻活动性炎症病变，其对肌成纤维细胞和TGF-β1的表达影响不显著，慢性纤维化病变无显著减少。     

霉酚酸酯对2型糖尿病大鼠肾脏单核细胞趋化蛋白-1表达的影响

目的:探讨霉酚酸酯对2型糖尿病大鼠肾脏单核细胞趋化蛋白-1(monocyte chemoattractant protein-1,MCP-1)表达的影响.方法:将实验动物分为正常对照组、糖尿病组及霉酚酸酯治疗组.霉酚酸酯治疗组给予霉酚酸酯(my cophenolate mofetil,MMF;15 mg·kg-1·d-1)治疗.13周后检测各组大鼠尿白蛋白排泄率、内生肌酐清除率、血糖、血脂、血胰岛素;HE 及PAS 染色观察肾脏病理改变;用免疫组化方法检测肾组织中MCP-1及单核/巨噬细胞(ED-1)的表达.结果:MMF可以减少2型糖尿病大鼠24 h尿蛋白排泄率及内生肌酐清除率,使大鼠肾脏组织中MCP-1和ED-1的表达降低,并改变肾脏病理结构.结论:霉酚酸酯对2型糖尿病大鼠肾脏有部分保护作用,其机制可能通过部分下调2型糖尿病大鼠肾脏MCP-1的表达来实现的.     

细胞因子信号传导抑制蛋白1抑制高糖诱导的肾小球系膜细胞单核细胞趋化蛋白1的表达

目的 探讨细胞因子信号传导抑制蛋白1(SOCS-1)对高糖状态下肾小球系膜细胞单核细胞趋化蛋白1（MCP-1）表达的影响。 方法 体外培养人肾小球系膜细胞,应用脂质体2000分别转染pCR3.1-SOCS-1表达质粒和pCR3.1 空质粒载体,G418筛选阳性克隆。分别采用低糖（5.5 mmol/L）、高糖（30 mmol/L）、低糖+甘露醇（24.5 mmol/L甘露醇）和JAK-STAT信号通路抑制剂AG490 （10 μmol/L）进行刺激。Western印迹检测系膜细胞SOCS-1、信号转导和转录活化因子1、3（STAT1、STAT3）及其磷酸化蛋白（p-STAT1、p-STAT3）的表达。ELISA法和放免法测定细胞上清液中MCP-1、FN和Ⅳ型胶原的含量。RT-PCR法检测SOCS-1和MCP-1 mRNA的表达。 结果 高糖刺激系膜细胞SOCS-1蛋白和mRNA表达呈时间依赖性变化, 4 h表达达到峰值,然后逐渐减低,24 h达基线水平。与低糖组相比,高糖组系膜细胞STAT1和STAT3磷酸化水平显著上调（P < 0.01）; MCP-1 mRNA水平表达显著上调[（0.39±0.05）比（0.16±0.02）,P < 0.01];上清液中MCP-1[（459±67）比（241±19） ng/L]、FN[（5.84±0.61）比（3.41±0.31） mg/L]和Ⅳ型胶原[（16.45±2.30）比（9.56±1.52） μg/L] 含量均显著增加（均P < 0.01）。与空载体对照组相比,SOCS-1过表达组系膜细胞STAT1和STAT3的磷酸化水平显著下降（P < 0.05）;MCP-1 mRNA表达下调[（0.34±0.04）比（0.42±0.05）,P < 0.05]; 上清液中MCP-1[(387±47）比（463±56） ng/L]、 FN[（4.61±0.57）比（5.76±0.74） mg/L]和Ⅳ型胶原[(13.4±2.32)比（17.1±2.57） μg/L] 含量显著减少（均P < 0.05）。与高糖组相比,AG490组系膜细胞MCP-1 mRNA（0.31±0.04）表达显著下调;上清液中MCP-1[（361±53） ng/L]、FN[（5.46±0.71）mg/L]和Ⅳ型胶原[（15.2±1.97） μg/L]含量均减少。 结论 SOCS-1过表达抑制高糖状态下肾小球系膜细胞MCP-1及细胞外基质的分泌可能部分是通过影响STAT1和STAT3的激活而实现。     

Vasopressor hormone response following mesenteric traction during major abdominal surgery

Background : We investigated the vasopressor hormone response following mesenteric traction (MT) with hypotension due to prostacyclin (PGI₂) release in patients undergoing abdominal surgery with a combined general and epidural anesthesia. Methods : In a prospective, randomized, placebo-controlled study we administered 400 mg ibuprofen (i.v.) in 42 patients scheduled for abdominal surgery. General anesthesia was combined with epidural anesthesia (T4-L1). Before as well as 5, 15, 30, 45, and 90 min after MT we recorded plasma osmolality, hemodynamics and measured 6-keto-PGFlα (stabile metabolite of PGI₂), TXB₂ (stabile metabolite of thromboxane A₂) active renin, and arginine vasopressin (AVP) plasma concentrations by radioimmunoassay. Catecholamine levels were assessed by high-pressure liquid chromatography (HPLC) with electrochemical detection. Results : Following MT, arterial hypotension occurred along with a substantial PGI₂ release. This was completely abolished by ibuprofen administration. Although plasma levels of 6-keto-PGF_1α (1133 (708) vs. 60 (3) ng/L, median (median absolute deviation), P=0.0001, placebo vs. ibuprofen) remained significantly elevated, blood pressure was restored within 30 min after MT in the placebo group. At the same point in time plasma concentrations of TXB² (164 (87) vs. 58 (1) ng/L, P=0.0001), epinephrine (46 (33) vs. 14 (6) ng/L, P=0.001), AVP (41 ± (18) vs. 12 (7) ng/L, P=0.0004), and active renin (27 (12) vs. 12 (4) ng/L, P = 0.001) were significantly higher in placebo-treated patients. Conclusion : Under combined general and epidural anesthesia arterial hypotension following MT due to endogenous PGI₂ release is associated with enhanced release of AVP, active renin, epinephrine and thromboxane A₂, presumably contributing to hemodynamic stability within 30 min after MT.     

Microspheres Based Detoxification System: A New Method in Convective Blood Purification

Abstract: A variety of protein-bound or hydrophobic substances, accumulating as a result of pathologic conditions such as exogenous or endogenous intoxications, are removed poorly by conventional detoxification methods because of low accessibility (hemodialysis), insufficient adsorption capabilities (hemosorption), low efficiency (peritoneal dialysis), or economic limitations (high-volume plasmapheresis). Combining advantages of existing methods with microspheric technology, a module-based system was designed. Major operating parameters of the latter can be modified to allow for adjustment to individual clinical situations. An extracorporeal blood circuit including a plasmafilter is combined with a secondary high-velocity plasma circuit driven by a centrifugal pump. Different microspheric adsorbers can be combined in one circuit or applied in sequence. Thus, a prolonged treatment can be tailored using specially designed selective adsorber materials. Comparing this system with existing methods (high-flux hemodialysis, molecular adsorbent recycling system), results from our in vitro studies and animal experiments demonstrate the superior efficiency of substance removal.     

Bariatric Surgery in Some "Central and East-European (former Eastern bloc)"Countries - Current Status and Prediction for the Next Millennium

Background: Obesity is increasing globallly, including in the formerly "Eastern Bloc" countries. Methods: A survey was made of obesity and bariatric surgery. Results: In the 8 East and Central European countries studied, with total population 300 million, roughly 43% of the population was overweight (BMI 25-30), 23% obese (BMI > 30), with about 15 million people morbidly obese (BMI > 40). From 0-10 morbidly obese individuals/100,000/year undergo bariatric surgery. Conclusion: Most countries were found to provide inadequate treatment for obesity.The majority of the morbidly obese are not treated effectively. However, health-care awareness of obesity and bariatric surgeons are slowly increasing.     

Synergistic interaction between the effects of propofol and midazolam with fentanyl on phrenic nerve activity in rabbits

Background: It has been shown that the depressive effects of both propofol and midazolam on consciousness are synergistic with opioids, but the nature of their interactions on other physiological systems, e. g. respiration, has not been fully investigated. The present study examined the effect of propofol and midazolam alone and in combination with fentanyl on phrenic nerve activity (PNA) and whether such interactions are additive or synergistic. Methods: PNA was recorded in 27 anaesthetised and artificially ventilated rabbits. In three groups, propofol, fentanyl and midazolam were administered intravenously in incremental doses to construct dose-response curves for the depressant effects of each one on PNA. In another two groups, the effect of pretreatment with either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. on the effects of propofol and fentanyl respectively on PNA were studied. Results: Propofol and fentanyl caused a dose-dependent depression of PNA with complete abolition at the highest total doses of 16 mg · kg^?1 i. v. and 32 μg · kg^?1 i. v., respectively. In contrast, midazolam in incremental doses to a total of 0.8 mg · kg^?1 reduced mean PNA by 63%, but approximately 12% of PNA remained at a total dose as high as 6.4 mg · kg^?1. The mean ED₅₀s, calculated from dose-response curves, were 5.4 mg · kg^?1, 3.9 μg · kg^?1 and 0.4 mg · kg^?1 for propofol, fentanyl and midazolam, respectively. Initial doses of either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. acted synergistically with subsequent doses of either propofol or fentanyl to abolish PNA at total doses of 8 mg · kg^?1 and 8 μg · kg^?1, respectively. Conclusion: Fentanyl has a synergistic interaction with both propofol and midazolam on PNA and hence potentially on respiration.     

Influence of dopexamine hydrochloride on haemodynamics and regulators of circulation in patients undergoing major abdominal surgery

Background: Catecholaminergic support is often used to improve haemodynamics in patients undergoing major abdominal surgery. Dopexamine is a synthetic vasoactive catecholamine with beneficial microcirculatory properties. Methods: The influence of perioperative administration of dopexamine on cardiorespiratory data and important regulators of macro- and microcirculation were studied in 30 patients undergoing Whipple pancreaticduodenectomy. The patients received randomized and blinded either 2 μg · kg^?1 · min^?1 of dopexamine (n=15) or placebo (n=15, control group). The infusion was started after induction of anaesthesia and continued until the morning of the first postoperative day. Endothelin-1 (ET-1), vasopressin, atrial natriuretic peptide (ANP), and catecholamine plasma levels were measured from arterial blood samples. Measurements were carried out after induction of anaesthesia, 2 h after onset of surgery, at the end of surgery, 2 h after surgery, and on the morning of the first postoperative day. Results: Cardiac index (CI) increased significantly in the dopexamine group (from 2.61±0.41 to 4.57±0.78 1 · min^?1 · m^?2) and remained elevated until the morning of the first postoperative day. Oxygen delivery index (DO₂I) and oxygen consumption index (VO₂I) were also significantly increased in the dopexamine group (DO₂I: from 416±91 to 717±110 ml/m² · m²; VO₂I: from 98±25 to 157±22 ml/m² · m²), being significantly higher than in the control group. pHi remained stable only in the dopexamine patients, indicating adequate splanchnic perfusion. Vasopressive regulators of circulation increased significantly only in the untreated control patients (vasopressin: from 4.37±1.1 to 35.9±12.1 pg/ml; ET-1: from 2.88±0.91 to 6.91±1.20 pg/ml). Conclusion: Patients undergoing major abdominal surgery may profit from prophylactic perioperative administration of dopexamine hydrochloride in the form of improved haemodynamics and oxygenation as well as beneficial influence on important regulators of organ blood flow.     

Systemic analgesia adapted to the children's condition

A concept of balanced analgesia using nonsteroidal anti-inflammatory drugs (NSAIDs), paracetamol (acetaminophen), opioids, and corticosteroids can also be used in patients with pre-existing illnesses. NSAIDs are the most effective treatment for acute pain of moderate intensity in children; however, these drugs should be avoided in patients at increased risk for serious side effects, e.g. patients with renal impairment, bleeding tendency, or extreme prematurity. NSAIDs can be given with minimal risks to the younger child with mild to moderate asthma, and, in these patients, the use of steroids can be encouraged; in addition to their antiemetic and analgesic action, a beneficial effect on asthma symptoms can be expected. In the non-intubated child with cerebral trauma, exaggerated sedation caused by opioids and increased bleeding tendency caused by NSAIDs must be avoided. In neonates and small infants, the oral administration of sucrose or glucose is helpful to minimize pain reaction during short uncomfortable interventions.     

Intraoperative autotransfusion is associated with modest reduction of allogeneic transfusion in prosthetic hip surgery

Background: The efficacy of intraoperative salvage and washing of wound blood and the predictors of allogeneic red cell transfusions in prosthetic hip surgery are insufficiently known.
Methods: In 96 patients, undergoing primary or revision surgery, salvaged and washed red cells and, if necessary, allogeneic blood were used to keep haematocrit not lower than 33%. The bleeding of red cells during hospital stay was calculated from the red cell balance. The preoperative red cell reserve (millilitres of red cells in excess of a haematocrit of 33%) was estimated and the difference between this volume and the total bleeding of red cells was retrospectively used to classify patients with regard to the need for red cells. Stepwise regression analysis was used to define patient-related variables associated with allogeneic blood transfusion.
Results: Preoperative knowledge of the type of operation (primary, revision), the preoperative red cell reserve, and the body mass could predict roughly half of the need for banked blood (r²=0.45). Only one-third of the total bleeding of red cells was retransfused. For complete avoidance of allogeneic blood, autotransfusion was most effective in patients with a moderate need (0–4 u). However, 32% of such patients required allogeneic blood.
Conclusions: Autotransfusion has a limited efficacy to decrease the need for allogeneic blood, and other blood-saving methods should be added for this purpose. It is difficult to predict the need for allogeneic blood preoperatively.     

缺氧对肾小管上皮细胞分泌外泌体的影响

目的    观察缺氧对肾小管上皮细胞分泌外泌体的影响,探讨外泌体在缺氧致肾脏损伤中的作用及机制。 方法    （1）常氧（21% O₂）及缺氧（1% O₂）分别处理大鼠肾小管上皮细胞（NRK-52E）48 h,收集细胞上清液并使用高速梯度离心法分离外泌体。采用透射电镜、纳米示踪分析、Western印迹、蛋白浓度定量鉴定并比较两组外泌体的基本特性。（2）在共培养实验中,以不同浓度（1、10、50、100、300 mg/L）的常氧外泌体、缺氧外泌体分别干预脂多糖（LPS）诱导的大鼠原代腹腔巨噬细胞,使用实时荧光定量PCR与酶联免疫吸附试验（ELISA）法分别检测巨噬细胞白细胞介素6（IL-6）、肿瘤坏死因子α（TNF-α）、诱导型氮氧化物合酶（iNOS）水平;使用Western印迹法检测巨噬细胞磷酸化（p）STAT/STAT及细胞因子信号传导抑制蛋白1（SOCS1）的蛋白表达;最后,使用实时荧光定量PCR法检测常氧外泌体与缺氧外泌体中炎性反应相关微RNA（microRNA,miR）的表达差异。 结果    （1）离心得到的囊泡具有外泌体典型的结构,粒径小于150 nm,表达外泌体标志蛋白CD63,说明分离得到外泌体。缺氧对肾小管上皮细胞分泌的外泌体形态、粒径分布比例无明显影响,但提高了外泌体的分泌量。（2）缺氧外泌体相比于常氧外泌体促进了LPS诱导的M1型巨噬细胞IL-6、TNF-α、iNOS 的表达和分泌（均P＜0.01）,同时提高STAT的磷酸化水平并减少SOCS1的蛋白表达（均P＜0.01）;对炎性反应相关microRNA检测发现缺氧外泌体中miR-155、miR-27a表达量较常氧外泌体明显升高（P＜0.05）。 结论    缺氧可改变外泌体的生物学功能,表现为协同促进LPS诱导的M1型巨噬细胞的表型转化,这可能是慢性肾脏病微炎性反应状态持续的原因之一。     

In Vitro Function and Durability Assessment of a Novel Polyurethane Heart Valve Prosthesis

Abstract While flexible-leaflet, central-flow prosthetic heart valves promise relief from anticoagulation therapy, they continue to be restricted by inadequate durability. In consequence, a novel trileaflet valve, made entirely from polyurethane, has been developed. A batch of 6 consecutively manufactured polyurethane valves was subjected to hydrodynamic function and accelerated fatigue testing. Computerized data acquisition and control systems have been introduced to improve valve testing methodologies. In terms of hydrodynamic function, the polyurethane valve demonstrates transvalvular pressure gradients similar to those for a bioprosthetic valve (Carpentier-Edwards) and levels of retrograde flow significantly less than those for either the bioprosthetic valve or a bileaflet mechanical valve (St Jude Medical). The equivalent of 10 years of cycling without failure has been exceeded by all 6 polyurethane valves in accelerated fatigue tests with 2 valves remaining intact after 674 million cycles (equivalent to approximately 17 years) in continuing tests. Highspeed photography revealed considerable differences in leaflet motion between valves cycled at accelerated and physiological rates.     

Negative pressure ventilation vs. spontaneous assisted ventilation during rigid bronchoscopy: A controlled randomised trial

Background: Ventilation during interventional rigid bronchoscopy (IRB) under general anaesthesia (jet ventilation, positive pressure ventilation and spontaneous assisted ventilation) may offer some difficulties. This study compares the effectiveness during IRB of intermittent negative pressure ventilation (INPV) and spontaneous assisted ventilation (SAV). Methods: Thirty-eight patients submitted to IRB were randomised into two groups: SAV or INPV. All patients received a total intravenous anaesthesia; INPV patients were paralysed. Pre-and intra-operative arterial blood gases and O₂ flow through a rigid bronchoscope were assessed. The endoscopist applying a subjective score evaluated the operating conditions. Results: Patients of the INPV group, as compared to the SAV group, required a lower dosage of fentanyl (2.6 ± 1.8 (μg · kg^?1· h^?1 vs. 6.6 ± 4.8 μg · kg^?1· h^?1), a lower O₂ supply (3.3 ± 2.8 1/min vs. 11.6 ± 3.4 1/min), a shorter recovery time (5.4 ± 2.9 min vs. 9.8 ± 7.1 min) and no manually assisted ventilation (0 ± 0 vs. 1 ± 1.1 nd?/procedure). Intraoperative PaCO₂ was higher in the SAV (8.1 ± 1.3 kPa) than in the INPV group (5.0 ± 1.6 kPa) and intraoperative pH differed in the two groups (7.26 ± 0.05, SAV vs. 7.47 ± 0.08, INPV). Operating conditions, as assessed by a subjective score, were considered better with INPV than with SAV (4.9 vs. 4.3). Conclusions: As compared to SAV, INPV in paralysed patients during IRB reduces administration of opioids, shortens recovery time, prevents respiratory acidosis, excludes the need for manually assisted ventilation, reduces 02 need and affords optimal surgical conditions. INPV appears a safe, non-invasive and effective ventilatory management during IRB.