丙泊酚复合雷米芬太尼行颅脑手术麻醉的血药浓度

目的探讨丙泊酚复合雷米芬太尼行颅脑手术时两药合适的血浆药物浓度。方法60例择期颅内肿瘤手术患者,随机分为P4组(n=30)和P6组(n=30),所有患者均采用雷米芬太尼18μg·kg-1·h-1和丙泊酚12mg·kg-1·h-1恒速泵注麻醉诱导,根据需要补充丙泊酚0.5~1mg/kg保持脑电双频指数(BIS)低于60。P4组采用丙泊酚4mg·kg-1·h-1,P6组采用6mg·kg-1·h-1;复合雷米芬太尼10μg·kg-1·h-1维持麻醉。术中根据BIS的变化增加或减少丙泊酚的输入量,维持BIS在40~60。记录不同时点的BP、HR、BIS,记录各组丙泊酚的累积用量和血管活性药物的使用情况,测定血浆丙泊酚浓度。结果两组麻醉诱导平稳,无插管反应发生。麻醉中P4组BIS(49.70±2.75)显著高于P6组(45.80±3.82);P4组和P6组丙泊酚麻醉维持平均剂量分别为(4.43±0.42)和(5.77±0.38)mg.kg-1.h-1。P4组和P6组血丙泊酚浓度分别为(2.00±0.35)和(2.58±0.45)μg/ml。结论丙泊酚复合10μg·kg-1·h-1雷米芬太尼全凭静脉麻醉行颅脑手术,合适的血浆靶控浓度宜为(2.32±0.55)μg/ml。     

喉罩-雷米芬太尼复合七氟醚或丙泊酚麻醉在烧伤整形术中的应用

目的 比较喉罩-雷米芬太尼联合七氟醚与喉罩-雷米芬太尼联合丙泊酚两种麻醉方法在整形手术中应用的优缺点.方法 30例择期疤痕切除植皮术患者,随机均分为喉罩-雷米芬太尼联合七氟醚(S)组与喉罩-雷米芬太尼联合丙泊酚(P)组.静脉诱导置人喉罩后,S组静脉泵入0.15μg·kg-1·min-1雷米芬太尼及吸入2%～3%七氟醚维持麻醉.P组患者通过外周静脉泵入雷米芬太尼0.15μg·kg-1·min-1及丙泊酚6～8 mg·kg-1·h-1维持麻醉.记录患者术中生命体征、苏醒时间、术中及术后并发症发生情况.结果 麻醉诱导后两组患者MAP及HR均明显低于麻醉前水平(P<0.05),S组MAP、HR在切皮前已恢复到术前水平,而P组术中各个时点MAP及HR仍明显低于麻醉前水平及对应时间点的S组(P<0.05).结论 与喉罩-雷米芬太尼联合丙泊酚比较,喉罩-雷米芬太尼联合七氟醚用于烧伤整形手术具有血流动力学更稳定、麻醉更平稳等优点.     

雷米芬太尼在宫腔镜手术中的应用

目的观察单纯输注雷米芬太尼对宫腔镜手术患者呼吸及循环功能的影响。方法选择拟行宫腔镜手术患者60例,随机均分为雷米芬太尼组(R组)和丙泊酚复合芬太尼组(PF组)。R组静注雷米芬太尼1μg/kg,继而以6μg·kg-1.h-1的速率输注。PF组静注芬太尼1μg/kg、丙泊酚2mg/kg,继而以4mg·kg-1.h-1输注丙泊酚。观察术前基础值(T1),注药后5min(T2)、10min(T3)、15min(T4)以及停药后5min(T5)的循环、呼吸情况,并记录意识消失时间、清醒时间、定向力恢复时间。结果与T1时相比,R组各时点MAP无明显变化,T2~T4时HR明显减慢(P<0.05),分钟通气量(MV)减少(P<0.01),PETCO2升高(P<0.01),但均保持自主呼吸;而PF组T2~T4时MAP明显下降,HR明显减慢(P<0.05),呼吸抑制明显,均需进行控制呼吸或辅助呼吸,其中有25例患者出现呼吸停止。T5时R组的MAP、HR和MV与T1时相比差异无统计学意义,而PF组MAP和MV明显降低(P<0.05),HR明显减慢(P<0.05)。R组术中体动患者明显少于PF组(P<0.05),患者均保持清醒而安静,而PF组患者均意识消失。结论在宫腔镜手术麻醉中,单纯输注雷米芬太尼可使患者保持自主呼吸,意识清醒而安静,并对循环影响轻微。     

小剂量氯胺酮对脑电熵指数和脑电双频指数的影响

目的比较小剂量氯胺酮对脑电熵指数(RE、SE)和脑电双频指数(BIS)的影响。方法22例ASAⅠ或Ⅱ级择期行腹腔镜子宫切除术及卵巢囊肿切除术患者,随机均分为氯胺酮组(K组)和生理盐水组(S组)。麻醉诱导:丙泊酚1～2mg/kg、雷米芬太尼1～1.5μg/kg和维库溴铵0.1～0.15mg/kg,气管插管。麻醉维持:丙泊酚6～8mg.kg-1.h-1、维库溴铵0.1mg.kg-1.h-1和雷米芬太尼7～10μg.kg-1.h-1。在稳定的麻醉和手术状况下,分别单次给予患者氯胺酮0.5mg/kg(K组)或等量的生理盐水(S组),记录给药前(基础值)、给药后5、10、15、20、25和30min七个时点MAP、HR、RE、SE和BIS的数值。结果K组和S组MAP、HR、RE、SE和BIS的基础值差异均无统计学意义。K组RE、SE和BIS在给药后迅速升高,然后逐渐下降,在给药后10min达到峰值,分别比基础值升高了43.8%(P<0.01)、43.2%(P<0.01)和28.8%(P<0.01)。RE和SE增加的幅度显著高于BIS,熵指数和BIS增加持续的时间分别为25min和20min。S组在给药后RE、SE和BIS值与基础值相比差异均无统计学意义。K组和S组在给药前后MAP和HR变化差异无统计学意义。结论在丙泊酚-雷米芬太尼麻醉期间,单次加入小剂量的氯胺酮,熵指数和BIS均不能准确反映其真正的麻醉深度。     

雷米芬太尼对小儿心内直视手术心肺转流前血流动力学的影响

目的 观察不同剂量雷米芬太尼对小儿心内直视手术心肺转流(CPB)前血流动力学的影响.方法 75例拟行先天性心脏病矫治患儿随机均分为四个不同剂量的雷米芬太尼组和芬太尼组(F组).麻醉诱导静注芬太尼10μg/kg、雷米芬太尼2μg/kg;麻醉维持于切皮前10 min分别静脉泵注雷米芬太尼0.5μg·kg-1·min-1(R0.5组)、1.0μg·kg-1·min-1(R1.0组)、1.5μg·kg-1·min-1(R1.5组)、2.0μg·kg-1·min-1(R2.0组)和静注芬太尼10μg/kg(F组).记录麻醉前(T0)、插管后2 min(T1)、切皮后2min(T2)、劈胸骨后2 min(HR)的HR、MAP及各组开胸后到CPB前间羟胺的使用例数情况.结果 五组血流动力学在T0～T3时基本稳定.与F组比较,T3时R0.5、R1.0组FIR明显增快(P<0.05),R2.0组MAP降低(P<0.05).开胸后R2.0组间羟胺使用率(60%)明显高于F组(20%)(P<0.05).结论 输注雷米芬太尼0.5～1.5μg·kg-1·min-1能维持心内直视手术CPB前小儿的血流动力学稳定.     

意识指数监测在无痛肠镜检查术中的应用效果

目的观察意识指数(index of consciousness,IoC)监测在无痛肠镜检查术中的临床效果。方法选择自愿行无痛肠镜的男性患者200例,年龄18~65岁,随机均分为观察组(IoC组)和对照组(C组)。两组患者均采用TCI丙泊酚复合瑞芬太尼麻醉,丙泊酚血浆靶浓度从4.0μg/ml起始,瑞芬太尼0.05μg·kg-1·min-1持续泵注。IoC组IoC指数保持在50±3,根据IoC值调整丙泊酚靶浓度;C组术中根据血流动力学及体动反应调整麻醉深度。记录给药前即刻(T1)、睫毛反射消失(T2)、过脾曲(T3)、过肝曲(T4)和苏醒时(T5)的MAP、HR、SpO2及镜检时间、丙泊酚用量、术后苏醒时间、定向力恢复时间及正常行走时间,观察术中不良反应发生情况。结果与C组比较,IoC组丙泊酚用量明显减少,苏醒时间及定向力恢复时间明显缩短(P0.05),体动发生率明显降低(P0.05)。两组镜检时间、正常行走时间和呼吸抑制、头晕、恶心呕吐等不良反应发生率差异无统计学意义。结论 IoC监测用于无痛肠镜检查术可减少麻醉药物用量,缩短恢复时间。     

雷米芬太尼与芬太尼复合丙泊酚在纤维胃镜检查中的应用

目的探讨雷米芬太尼复合丙泊酚在纤维胃镜检查中的镇静效果和安全性.方法选择ASA Ⅰ～Ⅱ级90例门诊胃镜检查患者,随机分成三组,即丙泊酚组、芬太尼复合丙泊酚组（芬太尼组）和雷米芬太尼复合丙泊酚组（雷米芬太尼组）,每组30例.术中在置入胃镜前、胃镜经咽时、镜检时及镜检后5 min各时点监测HR、MAP、SpO2等.记录镇静起效时间、定向力恢复时间、镜检满意度、术中知晓、胃镜操作时间及不良反应.结果芬太尼组在置入胃镜前、胃镜经咽时、镜检时及镜检后5 min各时点HR明显减慢（P＜0.05）,丙泊酚组在胃镜经咽时、镜检时HR明显增快（P＜0.05）.芬太尼组MAP较丙泊酚组和雷米芬太尼组明显降低（P＜0.05）.检查过程中丙泊酚组和芬太尼组低血压发生率较雷米芬太尼组明显增高（P＜0.05）.丙泊酚组和芬太尼组注药时静脉疼痛及术后头晕发生率较雷米芬太尼组明显增高（P＜0.05）.丙泊酚组肢体扭动和呛咳呃逆等不良反应发生率较芬太尼组和雷米芬太尼组明显增高（P＜0.01）.结论纤维胃镜检查中采用雷米芬太尼和丙泊酚联合镇静,起效时间快、定向力恢复时间短、镜检满意度高、丙泊酚用量明显减少、费用更低、副作用少,且镇静效果增强,是一种安全、有效的方法.     

丙泊酚诱导时雷米芬太尼对老年患者意识消失的影响

目的研究靶控输注丙泊酚麻醉诱导时雷米芬太尼对老年人意识消失的影响。方法30名老年患者,随机分两组靶控输注雷米芬太尼4ng/ml组(R组)和生理盐水对照组(C组)。10min后同时靶控输注丙泊酚,效应浓度逐步上升(1,2,4μg/ml)。记录BIS、OAA/S、血液动力学变化、丙泊酚效应浓度及用量。结果OAA/S1分时,R组BIS值为62±18,C组为61±11。R组丙泊酚效应浓度为(1·1±0·4)μg/ml,C组为(2·0±0·4)μg/ml(P<0·05)。R组丙泊酚用量为(63±24)mg,C组为(141±34)mg(P<0·01)。结论雷米芬太尼能协同丙泊酚加强对老年人意识消失的作用。     

雷米芬太尼、芬太尼、氯胺酮复合丙泊酚用于小儿烧伤和整形手术的比较

目的比较雷米芬太尼、芬太尼和氯胺酮复合丙泊酚保留自主呼吸全麻用于小儿烧伤和整形手术,观察麻醉中血液动力学的变化和术后恢复时间以及不良反应。方法选择51例ASAⅠ～Ⅱ级择期烧伤或整形的患儿,随机均分为三组,丙泊酚与雷米芬太尼组(R组);丙泊酚与芬太尼组(F组);丙泊酚与氯胺酮组(K组)。观察并记录患儿给药前、给药后5min、切痂、植皮以及停药后5min时的MAP、HR、RR、SpO2、PETCO2和术后恢复时间以及不良反应。结果R组MAP和HR在给药后有所下降但术中基本保持平稳,而F组MAP和HR术中波动明显(P<0.05,P<0.01),K组术中MAP较高、HR较快(P<0.05,P<0.01)。R组术后恢复时间明显短于F组和K组(P<0.01),而F组又明显短于K组(P<0.05,P<0.01)。R组呼吸抑制发生率高于F组和K组。结论雷米芬太尼与丙泊酚复合较芬太尼与丙泊酚复合和氯胺酮与丙泊酚复合对术中血液动力学影响更小,术后苏醒时间更快,但应注意诱导时呼吸抑制的发生。     

丙泊酚复合瑞芬太尼行腹腔镜卵巢囊肿切除术的临床观察

目的观察丙泊酚复合瑞芬太尼行腹腔镜卵巢囊肿切除术麻醉诱导和拔管期的临床效果。方法选择ASAⅠ或Ⅱ级,腹腔镜下卵巢囊肿切除术患者60例,随机均分为丙泊酚复合瑞芬太尼组(PR组)和丙泊酚复合芬太尼组(PF组)。麻醉诱导:PR组丙泊酚2～3mg/kg、瑞芬太尼1μg/kg,然后泵注0.5μg·kg-1·min-1;PF组丙泊酚2～3mg/kg、芬太尼2～3μg/kg。麻醉维持:PR组丙泊酚75μg·kg-1·min-1、瑞芬太尼0.2μg·kg-1·min-1,根据血流动力学调整瑞芬太尼给药速度和丙泊酚靶浓度;PF组丙泊酚75μg·kg-1·min-1,于手术开始前加芬太尼4～5μg/kg,两组患者均在手术结束时同时停麻醉药。观察并记录患者麻醉前、气管插管后、气腹后5min、手术结束时的HR、MAP。记录诱导时间、睁眼时间、拔管时间。结果与麻醉前比较,PF组气管插管后和气腹后5min的HR增快、MAP升高(P<0.05);与PF组比较,PR组气管插管后和气腹后5min的HR减慢、MAP降低(P<0.05),且诱导时间、睁眼时间、拔管时间均缩短(P<0.05)。结论腹腔镜下卵巢囊肿切除术患者丙泊酚复合瑞芬太尼麻醉较之复合等效剂量芬太尼,术中血流动力学更稳定,术后清醒快、恢复迅速。     

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.