5-羟色胺受体激动剂对脊髓损伤猫排尿功能的影响

目的探讨5-羟色胺(5-HT)受体激动剂对猫脊髓损伤后膀胱过度活动的影响。方法雌性猫18只,其中正常假手术组5只,脊髓损伤组13只。术后6~8周,氯醛糖麻醉下,在猫颈动脉及膀胱内置管,连接压力感受器,记录诱发膀胱收缩的膀胱容量阈值、膀胱容量、剩余尿量、排尿量和血压。静脉注入5-HT1A受体激动剂8-OH-DPAT(0.3~30μg/kg)或5-HT1B/1D受体激动剂GR-46611(0.03~300μg/kg),得到剂量-效应曲线后再给予5HT1A受体抑制剂WAY-100635(300μg/kg),比较给药前后各项指标变化。结果正常猫使用8-OH-DPAT后,膀胱容量阈值、膀胱容量、剩尿量均有增加趋势,但差异无统计学意义;8-OH-DPAT和GR-46611均能使脊髓损伤猫的膀胱容量阈值、膀胱容量、剩余尿量增加,且效应随着剂量增加而增加,差异有统计学意义。WAY-100635能抵消8-OH-DPAT的作用,但对GR-46611无影响。结论5-HT1A和5-HT1B/1D受体激动剂能改善慢性脊髓损伤后的膀胱过度活动,增加膀胱容量。     

5-羟色胺1A受体激动剂改善脊髓损伤大鼠排尿功能障碍的实验研究

目的 研究5-羟色胺-1A(5-HTlA)受体激动剂对慢性脊髓损伤(spinal cord injury,SCI)大鼠排尿障碍的改善作用. 方法 雌性SD大鼠14只,体质量175 ～ 200 g.随机分为2组:实验组7只显微镜下大鼠T10棘突水平行脊髓离断建立脊髓损伤模型,正常对照组7只.8周后乌拉坦(1.3 g/kg)麻醉下,2组大鼠颈静脉和膀胱内置管,连接压力感受器,记录膀胱最大容量、残余尿量、排尿量和尿道外括约肌的肌电活动.静脉注入5-HTI A/7受体激动剂8-羟基-丙胺-四氢萘(8-OH-DPAT,0.03 ～1.00 mg/kg),得出剂量—效应曲线后再给予5HTIA受体抑制剂WAY-100635 (0.3g/kg).观察比较2组大鼠用药前后尿动力学指标的变化. 结果 随着8-OH-DPAT剂量增加,SCI大鼠膀胱容量从(33.2 ±8.3)ml降至(22.8±2.4) ml,排尿量从(0.14±0.08)ml增至(0.38 ±0.09) ml,残余尿量从(3.68±1.36)ml降至(1.84±0.21)ml,而膀胱最高压力从(27.1±3.6)mm Hg(1 mm Hg=0.133 kPa)降至(22.8±2.4) mm Hg,用药前后差异均有统计学意义(P＜0.05).对照组大鼠用药前后排尿情况变化差异无统计学意义.肌电图显示8-OH-DPAT引起SCI大鼠尿道外括约肌强直收缩中出现阶段性的松弛,正常对照组大鼠作用无明显改变. 结论 8-OH-DPAT可以剂量依赖性地部分恢复SCI大鼠的尿道外括约肌协调性松弛,从而降低膀胱容量,增加排尿量,减少残尿量,增加排尿效率,改善排尿障碍.     

5-HT7受体激动剂改善脊髓损伤大鼠排尿障碍

目的:研究五羟色胺-7受体激动剂对慢性脊髓损伤(spinal cord injury,SCI)大鼠排尿障碍的改善作用。方法:体重175～200g之间的SD雌性大鼠,脊髓损伤模型7只,正常对照8只。乌拉坦麻醉下,在正常大鼠和脊髓损伤的模型的大鼠颈静脉和膀胱内置管,连接压力感受器,记录膀胱最大容量、剩余尿量、排尿量和尿道外括约肌的肌电活动。静脉注入5-HT7受体激动剂LP44(3～300μg/kg)得到剂量-效应曲线随后再给予5-HT7受体抑制剂SB269970(100μg/kg)。结果:LP44剂量依赖性的降低SCI大鼠膀胱最大容量,并且增加排尿量、减少剩余尿量从而增加排尿效率。但是不能引起脊髓完好的大鼠排尿的改变。SB269970注入后可以逆转LP44的作用。同时LP44引起脊髓损伤大鼠尿道外括约肌强直收缩中出现阶段性的松弛,而对于脊髓完好的大鼠作用无明显改变。结论:LP44可以剂量依赖性地部分恢复SCI大鼠的尿道外括约肌协调性松弛,从而降低膀胱容量,增加排尿量,减少剩余尿量,结果增加排尿效率,改善排尿障碍。     

骶髓5-HT_(2A)受体对于正常大鼠排尿的影响

目的:探讨骶髓控制尿道外括约肌的Onuf's核中是否存在5-HT2A受体,并观察髓腔内给予该受体的拮抗剂酮舍林对于正常大鼠排尿的影响。方法:体重175~200g的SD雌性大鼠14只,随机分为两组:实验组7只,在脊髓L6~S1节段建立脊髓髓腔内置管模型,给予不同浓度的酮舍林(0.01~0.1mg/kg),得到剂量依赖性曲线后再给予5-HT2A受体激动剂DOI(2,5-dimethoxy-4-iodophenyl)-2-aminopropane hydrochloride(0.1mg/kg)。对照组7只,如上述建立脊髓髓腔内置管模型,在脊髓腔内给予生理盐水。3天后在乌拉坦麻醉下,在实验组和对照组大鼠的膀胱内置管连接压力感受器,分别记录实验组和对照组膀胱内压图(CMG)及排尿量、剩余尿量、膀胱容量。待测压结束后,用4%多聚甲醛进行血管灌注取出L6~S1脊髓做冷冻切片并做免疫组化染色,观察并记录5-HT2A受体在脊髓Onuf's核中不同运动神经元的分布情况。结果:对照组大鼠的排尿是节律性的舒缩活动,排尿效率高,高频震荡波(HFOs)的排列整齐并稳定;实验组大鼠在给予酮舍林后,排尿时HFOs的个数呈剂量依赖性减少,同时这种作用可以完全或部分被DOI所逆转,和对照组相比差异有统计学意义,而排尿量、膀胱容量及排尿效率有减少的趋势,但和对照组相比,差异无统计学意义。免疫组化结果显示在大鼠L6脊髓的背后外侧核(RDLN核)、脊髓前角的Ounf's核的背外侧核(DLN)、腹内侧核(VMN)有不同数量的5-HT2A受体免疫反应阳性产物蓄积。结论:骶髓控制大鼠尿道外括约肌舒缩活动的Onuf's核中存在5-HT2A受体,其拮抗剂酮舍林通过与5-HT2A受体特异性结合可以抑制尿道外括约肌的舒缩活动,但由于正常高位中枢的调节作用和受体数量的限制,不会对正常大鼠的排尿功能造成太大影响。     

侧脑室注射高选择性5-HT_（1A）受体拮抗剂或激动剂对大鼠神经病理性疼痛的影响

目的观察侧脑室注射高选择性5-HT1A受体激动剂8-OH-DPAT或拮抗剂WAY100635对大鼠神经病理性疼痛的影响。方法慢性结扎损伤（CCI）坐骨神经大鼠128只分为WAY100635组（W组,n=64）和8-OH-DPAT组（D组,n=64）,每组又分为8个亚组：WAY100635（1、2、4、8μg）-曲马多组（W1T组、W2T组、W4T组、W8T组）;WAY100635（1、2、4、8μg）-生理盐水组（W1N组、W2N组、W4N组、W8N组）;8-OH-DPAT（1、2、4、8μg）-曲马多组（D1T组、D2T组、D4T组、D8T组）;8-OH-DPAT（1、2、4、8μg）-生理盐水组（D1N组、D2N组、D4N组、D8N组）。另设空白对照组以同样方法暴露结扎坐骨神经（NN组,n=8）,建立CCI模型后腹腔和侧脑室均注射生理盐水。测定大鼠热痛敏阈（PWL）和机械痛敏阈（PWT）值。结果与NN组比较,W1T、W2T、W4T、W8T、W2N、W4N、W8N、D1T、D2T、D4T、D8T组PWL、PWT值明显升高（P〈0.01）。W4T、W8T、W2N、W4N、W8N组PWL、PWT值分别高于D4T、D8T、D2N、D4N、D8N组（P〈0.01）。结论曲马多的镇痛作用可以在中枢水平部分被5-HT1A受体激动剂拮抗,侧脑室注射5-HT1A受体拮抗剂WAY100635可以产生一定的镇痛作用。     

K-2阿片受体激动剂诱发大鼠膀胱括约肌和尿道外括约肌失协调

目的：通过脊髓鞘内给与选择性K1（U50,488）和K-2（GR89,696）阿片受体激动剂来验证脊髓K阿片受体亚型在大鼠尿道外括约肌控制中的作用。方法：乌拉坦麻醉雌性大鼠,膀胱顶部插管充盈膀胱诱发排尿进行膀胱测压,肌电图评估尿道外括约肌（EUS）功能,脊髓鞘内或静脉注射给药。结果：大鼠排尿时EUS在基础的（连续的）收缩活动之上出现高频舒张收缩以利于排空尿道完成排尿。GR-89,696（0．05to5μg鞘内注射it）使EUS每次排尿时的舒张收缩的次数呈剂量依赖性减少。它使排尿效率降低,大剂量时导致EUS排尿时的舒张收缩消失,呈持续收缩状态,出现膀胱逼尿肌和EUS协同失调和充盈性尿失禁。非选择性阿片受体拮抗剂纳洛酮（1mg／kg静脉注射iv）可阻滞GR89,696的效应。U-50,488（0．05 to 5μg鞘内注射it）对膀胱内压和EUS肌电图参数无影响。结论：大鼠有效的排尿需要依靠脊髓信号发生器刺激EUS运动神经元产生信号．使EUS产生舒张收缩,从而导致尿道快速的舒张与收缩以利于排空。脊髓鞘内注射K2阿片受体激动剂可以抑制信号发生器,减少每次排尿期舒张收缩的次数,但并不影响与尿道关闭有关的基础收缩。由此产生膀胱逼尿肌和EUS协同失调,导致排尿效率降低。和大鼠脊髓损伤导致的膀胱逼尿肌和EUS协同失调排尿障碍相似。因此,应该进一步研究K-2阿片受体在脊髓损伤导致的排尿障碍中的作用。     

远位触液神经元5-HT1A受体在大鼠神经病理性痛中的作用

目的 评价远位触液神经元5-羟色胺1A(5-HT1A)受体在大鼠神经病理性痛中的作用.方法 雄性SD大鼠40只,体重230～270 g,采用随机数字表法,将其随机分为4组(n=10):假手术组(S组)、神经病理性痛组(NP组)、二甲基亚砜组(DMSO组)和8-羟基-2-(双-正丙胺基)-四氢萘满组(8-OH-DPAT组).采用坐骨神经慢性压迫法(CCI制备大鼠神经病理性痛模型,S组仅暴露坐骨神经,但不结扎.CCI后第7天,8-OH-DPAT组和DMSO组向远位触液神经元分别缓慢注射5-HT1A受体特异性激动剂8-OH-DPAT或DMSO 1 μl,5 min内注射完毕.分别于CCI前(T0)、CCI后第7天(T1)和给药后3、6 h(T2,3)时,测定缩足潜伏期(PWL)和缩足阈值(PWT).于给药后6 h时处死大鼠,取脑组织,采用免疫荧光标记法检测远位触液核神经元5-HT1A受体的表达.结果 与S组比较,NP组、DMSO组和8-OH-DPAT组T1时PWL缩短,PWT降低(P＜0.01);与DMSO组比较,8-OH-DPAT组T2和T3时PWL延长,PWT升高(P＜0.01).与S组比较,NP组和DMSO组5-HT1A受体表达下调(P＜0.01);与NP组和DMSO组比较,8-OH-DPAT组5-HT1A.受体表达上调(P＜0.01);NP组和DMSO组间5-HT1A受体表达比较差异无统计学意义(P＞0.05).结论 远位触液神经元5-HT1A受体参与了大鼠神经病理性痛的调控.

Abstract：

Objective To evaluate the role of 5-HT1A receptors in distal cerebrospinal fluid (CSF)-contacting neurons in neuropathic pain (NP) in rats. Methods Forty male SD rats weighing 230-270 g were randomly divided into 4 groups (n = 8 each): sham operation group (group S); NP group; dimethyl sulfoxide (DMSO) group and 8-OH-DPAT (a specific 5-HT1A receptor agonist) group. NP was induced by chronic constrictive injury (CCI) in groups NP, DMSO and 8-OH-DPAT. Four silk ligatures were placed on the sciatic nerve at 1 mm intervals . In group S, the sciatic nerve was exposed but not ligated. 8-OH-DPAT and DMSO 1 μl were injected into the region where most of CSF-contacting neurons are present over 5 min on 7th day after CCI in groups 8-OH-DPAT and DMSO respectively. Paw withdrawal latency (PWL) and paw withdrawal threshold (PWT) were measured before CCI, on 7th day after CCI, and at 3 and 6 h after administration. The rats were sacrificed 6 h after administration, and the brain tissues removed for determination of the expression of 5-HT1A receptors in the distal CSF-contacting neurons by immunofluorescence. Results Compared with group S, PWL was significantly shorten and PWT decreased at T, in groups NP, DMSO and 8-OH- DPAT (P ＜ 0.01) . Compared with group DMSO, PWL was significantly prolonged and PWT increased at T2 and T3 in group 8-OH-DPAT ( P ＜ 0.01). The 5-HT1A receptor expression was significantly down-regulated in groups NP and DMSO compared with group S, while up-regulated in group 8-OH-DPAT compared with groups NP and DMSO ( P ＜ 0.01). There was no significant difference in 5-HT1A receptor expression between groups NP and DMSO ( P ＞ 0.05). Conclusion 5-HT1A receptors in distal CSF-contacting neurons are involved in the regulation of NP in rats.     

膀胱穿刺造瘘术结合康复功能训练对脊髓损伤后神经源性膀胱患者的效果分析

目的探讨膀胱穿刺造瘘术结合康复功能训练对脊髓损伤后神经源性膀胱患者的效果。方法回顾性分析本院2014年1月至2018年1月接诊的80例脊髓损伤后神经源性膀胱患者的诊疗及护理情况。根据护理方法的不同,将其分为对照组和观察组。对照组采取常规治疗及处理,观察组采取膀胱穿刺造瘘术结合康复功能训练。比较分析两组患者治疗后的临床疗效、治疗前后的残余尿量、膀胱压力、膀胱容量以及自行排尿率。结果观察组总有效率(97.50%)明显高于对照组(85.00%),两组比较差异有统计学意义(P0.05)。治疗后,两组患者的膀胱压力均明显降低,残余尿量明显减少,膀胱容量明显升高,治疗前后比较差异有统计学意义(P0.05)。治疗后,观察组残余尿量明显少于对照组,膀胱压力明显低于对照组,膀胱容量明显高于对照组,两组比较差异有统计学意义(P0.05)。观察组的自行排尿率(70.00%)明显高于对照组(57.50%),两组比较差异有统计学意义(P0.05)。结论膀胱穿刺造瘘术结合康复功能训练,能够有效提高脊髓损伤后神经源性膀胱患者的治疗效果,改善排尿状况,值得临床上广泛应用。     

骶神经根功能性磁刺激对脊髓损伤后神经源性膀胱过度活动症的作用

目的:观察骶神经根功能性磁刺激(functional magnetic stimulation,FMS)对脊髓损伤患者神经源性膀胱过度活动症(overactive bladder,OAB)治疗的效果。方法:将40例脊髓损伤后OAB患者按随机数字表法分为治疗组(20例)和对照组(20例)。两组患者均给予常规的膀胱功能干预,治疗组在此基础上给予骶神经根FMS(强度为70%～100%最大输出强度,频率15Hz,每分钟刺激5s,共刺激30min,每日1次,每周5次,共治疗8周),对照组则给予相同参数FMS(刺激线圈与治疗部位垂直,无刺激作用)。两组患者均于治疗前和8周后比较尿流动力学指标(初尿意时膀胱容量、最大膀胱测压容量、残余尿量)、排尿日记指标(单次尿量、排尿次数和最大排尿量)及因排尿不良而引起生活质量评分变化。结果:治疗8周后,两组患者尿流动力学及排尿日记指标较术前均显著改善。初尿意时膀胱容量(对照组65.25±6.41ml、治疗组78.44±9.52ml)增加(P0.05),最大膀胱测压容量(对照组339.55±36.75ml、治疗组394.46±36.68ml)显著增加(P0.05),残余尿量(对照组120.22±40.35ml、治疗组88.25±33.61ml)明显减少(P0.05);日均单次排尿量(对照组120.06±23.23ml、治疗组150.28±24.24ml)增加(P0.05),24h平均排尿次数(对照组12.28±3.31、治疗组9.44±3.95)减少(P0.05),最大排尿量(对照组233.58±47.14ml、治疗组274.51±30.18ml)显著改善(P0.05);因排尿症状而引起生活质量评分均明显降低;与组内治疗前比较,差异均有统计学意义(P0.05),且治疗组改善情况均显著优于对照组(P0.05)。结论:FMS可改善神经源性膀胱过度活动症患者的膀胱功能和提高患者的生存质量。     

体神经-内脏神经反射弧建立后脊髓损伤鼠排尿功能的改变以及可能机制

目的 建立新的体神经-内脏神经反射弧,应用尿流动力学方法来检测新反射弧建立后对清醒脊髓损伤(SCI)鼠膀胱功能及逼尿肌-尿道外括约肌协调性的影响以及可能机理。方法成年雄性大鼠(280～300)g在L4～L6的椎管内行L6腹侧根与L4腹侧根神经端端吻合,保留L4背根来传导来自新反射弧的皮肤传入信号。术后3个月行T9～T10椎间脊髓横断,8周后在清醒状态下检测容量诱发性排尿和电刺激新反射弧皮肤感觉传入区诱发排尿的膀胱压力变化图(CMG)和尿道外括约肌肌电图(EUS-EMG)各项参数的变化。结果 新的体神经-内脏神经反射弧建立后,在清醒状态下电刺激L4皮区可以诱发排尿,和不用电刺激的容量诱发性排尿(VEMR)相比排尿量增加、排尿压提高、排尿开放压提高,而残余尿减少,排尿效率明显增加,差异均有显著性(P<0.05)。EUS的肌电频率明显降低。结论 新反射弧建立后使 SCI鼠的排尿功能发生显著改变。电刺激反射弧的皮肤感觉区可以收缩膀胱逼尿肌使膀胱内压升高并同时使尿道外括约肌肌电频率下降,CMG和EUS的多项参数均有改善。逼尿肌-外括约肌不协调得到改善。     

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.