瑞芬太尼用于鼻内镜手术控制性降压对应激反应的影响

目的观察瑞芬太尼用于鼻内镜手术控制性降压对应激反应的影响。方法择期全麻下鼻内镜手术患者60例,ASAI-Ⅱ级,根据降压所用药物不同分为硝普钠组（N组,n=20）、瑞芬太尼组（R组,n=28）及瑞芬太尼复合硝普钠组（RN组,n=12）。常规麻醉诱导后,术者进行消毒时开始行控制性降压,维持MAP在60mmHg-70mmHg之间。分别记录控制性降压前即刻（L）,维持降压30min时（T1）及停止降压待血压自然恢复稳定后（T2）的HR、MAP。于T0、T1、T2时分别抽取动脉血测定血管紧张素Ⅱ（AT-Ⅱ）、醛固酮（ALD）、血栓烷B2（TXB2）、6-酮-前列腺素F1α（6-keto-PGFlα）、内皮素（ET）和一氧化氮（NO）的浓度。结果三组患者相比T1时点,N组HR比R组和RN组明显增快（P〈0．05）,N组降压停止后出现反跳性高血压,R组和RN组停止降压后MAP回复至降压前水平。T1、T2时点N组AT-Ⅱ、ALD的浓度比R和RN组明显升高（P〈0．05）。T1、T2时点RN组NO／ET比值明显高于同时点N组（P〈0．05）,T2时点R组NO／ET比值明显高于同时点N组（P〈0．05）。T1、T2时点R、RN组TXB2／PGF1α比值明显高于同时点R和RN组（P〈0．05）。结论瑞芬太尼持续输注用于异氟醚吸入麻醉下鼻内镜手术中控制性降压能够降低AT-Ⅱ和ALD的分泌,改善NO／ET平衡,降低TXB2／PGF1α比值,有效抑制机体应激反应。     

雷米芬太尼用于颅内肿瘤术中控制性降压

目的 探讨雷米芬太尼用于颅内肿瘤术中控制性降压效果.方法 择期50例颅内肿瘤手术患者随机分为雷米芬太尼组(R组)和硝普钠组(N组).手术开始时,R组给予雷米芬太尼0.10～0.20 μg·kg-1·min-1泵注,N组给予硝普钠3～8 μg·kg-1·min-1泵注.监测并记录麻醉诱导前(T0)、麻醉诱导后(T1)、开始降压前(T2)、开始降压后(T3)、停止降压5 min(T4)及停止降压30min(T5)时的MAP、HR、SpO2、PETCO2、CVP及围术期总输液量、输血量、出血量和尿量.结果 与T0时比较,两组T1～T4时MAP明显降低,R组HR明显减慢,T1时N组HR明显减慢,T2～T4时N组HR明显增快(P<0.05).与T1时比较,两组T2～T4时MAP明显降低(P<0.05),N组患者T5时MAP反跳性升高,且明显高于R组(P<0.05).与T1时比较,N组患者T2～T5时HR明显增快,且T2～T4时明显快于R组(P<0.05).R组的输液量、输血量、出血量均较N组明显减少(P<0.05).结论 雷米芬太尼可安全用于颅内肿瘤术中控制性降压.     

瑞芬太尼复合异氟烷控制性降压对神经外科手术患者肾素-血管紧张素-醛固酮系统的影响

目的观察瑞芬太尼复合异氟烷在神经外科手术中行控制性降压的效果,比较瑞芬太尼和硝普钠对患者肾素-血管紧张素-醛固酮系统（RAAS）的影响。方法择期行控制性降压的手术患者40例,ASA Ⅰ～Ⅱ级,气管插管后,控制呼气末异氟烷浓度为1．2％±0．2％。按降压方法将患者随机分为两组,每组20例,均使平均动脉压（MAP）降低至基础值的60％～70％（目标血压）。Ⅰ组：从1．0μg·kg^-1·min^-1的速度开始给予硝普钠,每隔30s增加0．5μg·kg^-1·min^-1直至血压达到目标血压。Ⅱ组：从（0．15～0．2）μg·kg^-1·min^-1的速度开始给予瑞芬太尼,每隔30s增加0．05μg·kg^-1·min^-1直至达到目标血压。在麻醉前（T0）、控制性降压前（T1）、控制性降压后5min（T2）、控制性降压后30min（T3）及控制性降压结束后20min（T4）记录MAP、HR、CVP,同时测定血中肾素、血管紧张素Ⅱ、醛固酮含量。由术者在不知道控制性降压方式的情况下评估术野质量。结果Ⅰ组T2～4的HR较T0和T1增加;Ⅱ组T2～4的HR较T0和T1减慢,也较Ⅰ组T2-4的HR慢;Ⅰ组T4的MAP、CVP较T1高,也高于Ⅱ组T4的MAP、CVP（P〈0．05或0．01）。Ⅰ组T2～4肾素、血管紧张素Ⅱ、醛固酮含量高于T0和T1,也高于Ⅱ组相应时点三种激素的含量（P〈0．05）。而Ⅱ组三种激素的含量在T0～4未见明显变化（P〉0．05）。Ⅱ组的出血量较Ⅰ组少,6点刻度表和VAS评分均低于Ⅰ组（P〈0．05）。结论与硝普钠相比,瑞芬太尼复合异氟烷控制性降压降压过程平稳,为手术提供更清晰的术野,并在控制性降压期间抑制RAAS。     

脊柱手术中应用雷米芬太尼控制性降压的研究

目的对比评价脊柱手术中应用雷米芬太尼或硝酸甘油行控制性降压麻醉的效果。方法30例后路椎间盘(植骨)融合术的病人,年龄18~65岁,随机分为雷米芬太尼组(R组)和硝酸甘油组(N组),每组15例。两组病人麻醉诱导及维持方法相同。R组以雷米芬太尼2μg/kg静注,0·1~0·5μg·kg-1·min-1维持;N组以硝酸甘油2μg/kg静注,0·5~3μg·kg-1·min-1维持,均将MAP降至60~65mmHg,持续60min。观察两组病人术中MAP、CVP、HR变化,失血量及清醒拔管时间的差异。结果降压期间R组的HR显著低于降压前(P<0·05,P<0·01),而N组显著高于降压前(P<0·05)。N组降压5、10、15min时的CVP显著低于降压前(P<0·05),R组与降压前相比差异无显著意义。R组术中失血量明显少于N组(P<0·01)。两组病人清醒拔管时间差异无显著意义。结论雷米芬太尼可有效用于脊柱手术术中控制性降压。与硝酸甘油相比,具有减慢HR、降压平稳、对CVP影响小、失血量少等优点。     

七氟醚复合瑞芬太尼在外科手术中控制性降压的效果及对内脏灌注的影响

目的：比较七氟醚复合瑞芬太尼和硝普钠在神经外科手术患者中控制性降压效果、对内脏灌注的影响。方法选取行择期手术的神经外科患者42例为研究对象,随机将患者分为观察组及对照组,每组21例。观察组应用七氟醚复合瑞芬太尼,对照组应用硝普钠行降压麻醉。记录两组麻醉前10分钟（T0）,降压后0.5小时（T1）、降压后1小时（T2）、降压后2小时（T3）以及术后1小时（T4）,两组患者的心率（HR）以及平均动脉压（MAP）,并测定两组患者胃粘膜pH值（pHi）以及胃粘膜CO2分压（PgCO2）。结果在 T1~T2阶段两组患者 MAP均低于 T0阶段,在T3~T4时观察组患者低于对照组患者,差异具有统计学意义（P＞0.05）;在T1~T4阶段对照组患者HR明显快于T0阶段及观察组,差异具有统计学差异（P＞0.05）;在T1~T3阶段两组患者pHi显著低于T0,PgCO2显著高于T0,差异具有统计学意义（P＞0.05）。组间比较无统计学差异。结论在脑外科患者中应用七氟醚复合瑞芬太尼对患者进行控制性降压,可改变胃粘膜pHi值,并呈逆转性变化,患者在降压后短时间内内脏灌注恢复正常水平,与硝普钠控制性降压相似,且与硝普钠相比,不易引起反射性心率加快及停药后的血压反跳,降压更为安全、有效。     

艾司洛尔复合硝普钠控制性降压用于关节镜下肩袖修补术的临床观察

目的研究艾司洛尔复合硝普钠控制性降压用于半坐卧位肩关节镜下肩袖修补的可行性及安全性。方法 2010年7月～2011年5月,选择50例单侧肩袖撕裂行关节镜手术患者,按病例单双号分为2组,每组25例。S组（单纯硝普钠组）用微量泵以0.5～5.0μg/（kg.min）速率输注硝普钠,ES组（艾司洛尔＋硝普钠组）在泵注硝普钠的同时泵注艾司洛尔150～300μg/（kg.min）。2组平均动脉压均缓慢降至55～65 mm Hg。监测降压前,降压后5 min、15 min、45 min,停药后5min、10 min的平均动脉压（MAP）、心率（HR）、心电图（ECG）、脉搏血氧饱和度（SpO2）、呼气末CO2分压（PETCO2）及颈内静脉球部血氧含量（SjvO2）,记录关节冲洗液量、尿量、硝普钠用量、手术时间、术中术野质量评分等指标。结果 2组降压后HR差异有显著性（P〈0.01）,S组伴HR升高,而ES组在降低MAP的同时可减慢HR。停药后,S组反跳性引起HR、MAP增高,ES组停药反跳不明显,2组间差异有显著性（P〈0.01）。2组降压后SjvO2有轻微下降,但均在正常范围内,差异无显著性（P〉0.05）。ES组关节冲洗液量、硝普钠用量及手术时间少于S组,术野评分优于S组,差异有显著性（P〈0.01）。结论硝普钠-艾司洛尔联合应用可使控制性降压前后的机体生理变化更趋于平稳,减少硝普钠用量,使术野更清晰,缩短手术时间,减少关节冲洗液量,脑氧代谢良好。     

尼卡地平、硝普钠用于控制性降压对鼻内镜手术脑氧代谢的影响

目的比较鼻内镜手术中应用尼卡地平、硝普钠行控制性降压对脑氧代谢的影响。方法选择鼻息肉行内镜手术者30例,随机分为两组,分别采用尼卡地平(A组,n=15)和硝普钠(B组,n=15)行控制性降压。于不同时段降压前(T0)、降压后10 min(T1)、降压后30 min(T2)及停止降压后10 min(T3)行动静脉血气分析。结果①T1、T2时,B组HR明显快于T0时,且在此两时点HR明显快于A组(P<0.05)。②A组D(a-jv)O2、CERO2在T1、T2时较T0时明显下降,且在此两时点上明显低于B组(P<0.05)。结论尼卡地平、硝普钠均可安全用于鼻内镜手术中的控制性降压,都能降低脑氧代谢,但在降低脑氧代谢、改善脑氧合方面,尼卡地平优于硝普钠,有较好的脑保护作用。     

雷米芬太尼控制性降压对颅脑手术患者血液动力学的影响

目的观察神经外科手术中雷米芬太尼控制性降压对血液动力学的影响。方法20例ASAⅠ~Ⅱ级择期行颅脑手术患者,采用全凭静脉复合麻醉,术中持续泵注雷米芬太尼行控制性降压,维持MAP 60~70 mmHg,观察降压前(T0)、降压达目标时(T1)、维持降压15 min(T2)、30 min(T3)、停降压15 min(T4)3、0 min(T5)6个时点的MAP、HR、心输出量(CO)、心脏指数(CI)、心室收缩加速度指数(ACI)、左心做功(LCW)、外周血管阻力(SVR)的变化。结果与T0比较,T1、T2、T3时点MAP、SVR、LCW均显著降低(P<0.01);HR亦明显减慢(P<0.05);CO、CI、ACI无明显降低。结论神经外科手术中行雷米芬太尼控制性降压安全、有效,具有对心功能影响小的优点。     

不同剂量瑞芬太尼复合七氟醚控制性降压对神经外科手术患者脑氧代谢的影响

目的观察瑞芬太尼复合七氟醚控制性降压对神经外科手术患者脑氧代谢的影响。方法选择拟行控制性降压的神经外科手术患者60例,随机均分为三组:R1组为瑞芬太尼3ng/ml复合七氟醚组,瑞芬太尼效应室靶浓度设定为3ng/ml;R2组为瑞芬太尼6ng/ml复合七氟醚组,瑞芬太尼效应室靶浓度设定为6ng/ml;N组为硝普钠组。R1、R2组同时吸入七氟醚,控制七氟醚呼出气浓度为1MAC,N组泵注硝普钠的速率为1～3μg·kg-1·min-1。记录麻醉前10min(T0)、降压后10min(T1)、30min(T2)、停止降压10min(T3)、30min(T4)时的MAP和HR,采集相应时点的颈内静脉血和动脉血作血气分析,计算动脉血氧含量(CaO2)、颈内静脉球部血氧含量(CjvO2)、脑动-静脉血氧含量差(Da-jvO2)、脑氧摄取率(CERO2)。结果 T1～T4时R1、R2组,T1、T2时N组MAP明显低于T0时(P<0.01),T2时R2组MAP明显低于N组和R1组(P<0.05或P<0.01)。T1～T4时N组HR明显快于T0时和R1、R2组(P<0.01),T1～T3时R1、R2组HR明显慢于T0时,而T2时R2组HR明显慢于R1组(P<0.05或P<0.01)。T1～T4时三组CjvO2明显高于T0时(P<0.01),而Da-jvO2与CERO2明显低于T0时(P<0.01),T1、T2时R1、R2组CjvO2高于N组(P<0.05),而Da-jvO2与CERO2低于N组(P<0.05)。结论瑞芬太尼复合七氟醚控制性降压可降低神经外科手术患者的脑氧代谢,降压平稳迅速,HR缓慢,停止降压后无BP反跳现象,有利于围术期脑保护。     

预注美托洛尔对全麻术中血流动力学及血清皮质醇、一氧化氮的影响

目的观察预注美托洛尔对患者血流动力学、吸入麻醉药MAC值及血清皮质醇（Cor），一氧化氮（NO）的影响。方法择期行胃肠道手术的患者24例，ASAⅠ或Ⅱ级，随机分成两组，分别给予美托洛尔0．05mg／kg（M组）及生理盐水（C组）。手术中连续监测MAP、HR、ST段，分别记录基础值（T0）、给药后（T1）、气管插管后即刻（T2）、手术切皮前（T3）、进腹后（T4）、手术结束时（T5）的MAP、HR、ST段的数值及每小时异氟醚的MAC值。分别在T0、T4、T5抽取患者的静脉血约4ml进行Cor、NO的测定。结果M组的HR明显慢于C组（P〈0．01），MAC值低于C组（P〈0．01）。两组各时点的MAP、ST段、Cor和NO水平差异均无统计学意义。C组L时Cor水平明显高于T0时（P〈0．05）。两组T4、T5时NO均高于T0时（P〈0．05）。结论术前预注β受体阻滞药具有稳定血流动力学、降低异氟醚MAC值的作用。     

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.