过度训练可部分通过上调TLR4的表达激活死亡受体凋亡通路诱导大鼠肾小管上皮细胞凋亡

目的：观察过度训练大鼠肾组织TLR4、Fas及Caspase-8表达的变化,探讨TLR4在死亡受体凋亡通路中的作用。方法：将48只雄性SD大鼠按随机数字表法分为对照组（CN）、力竭运动组（ES）、山莨菪碱干预组（AD）。CN组为安静对照;ES组又根据力竭后恢复时间分为力竭后即刻（ESI）、力竭后6 h（ES 6 h）和力竭后24 h（ES 24 h）;AD组于力竭运动前20 min腹腔注射山莨菪碱10 mg/kg后进行力竭运动,分为AD 6 h和AD 24 h组。采用大鼠游泳至力竭建立过度训练模型。采用Western印记测定肾组织TLR4和Fas的表达,免疫组织化学法检测肾组织Caspase-8的表达,并分别对TLR4与Fas、Caspase-8、肾组织细胞凋亡率进行相关性分析。结果：Western印记测定结果显示,过度训练大鼠肾组织TLR4及Fas的表达于力竭后即刻、6 h及24 h逐渐增高,均显著高于对照组（P〈0.05）。免疫组化显示,过度训练大鼠肾组织Caspase-8的表达于力竭后即刻、6 h及24 h逐渐增强,均显著高于对照组（P〈0.05）。过度训练大鼠肾组织TLR4与Fas、Caspase-8和细胞凋亡率的表达均呈正相关性（r=0.848,P〈0.05;r=0.916,P〈0.05;r=0.95,P〈0.05）。用山莨菪碱干预后,过度训练引起的肾组织TLR4、Fas及Caspase-8的过度表达均被显著抑制（均P〈0.05）。结论：过度训练可通过上调TLR4强化死亡受体凋亡通路,进而诱导大鼠肾小管上皮细胞凋亡。     

山莨菪碱、旋覆花素和苦碟子对过度训练大鼠心肌Bcl-2和Bax蛋白表达的影响

目的探讨山莨菪碱、旋覆花素和苦碟子对过度训练大鼠心肌Bcl-2、Bax蛋白表达的影响。方法雄性Wistar大鼠80只,体重200～220 g,随机分为5组：正常对照组（C组,n=8）、力竭对照组（E组,n=24）、山莨菪碱组（A组,n=16）、旋覆花素组（IB组,n=16）、苦碟子组（IS组,n=16）。采用游泳至力竭建立过度训练动物模型,A组于力竭前即刻腹腔注射山莨菪碱10 mg/kg,IB组于力竭前24 h、即刻口腔灌入旋覆花素25 ml/kg,IS组于力竭前即刻腹腔注射苦碟子20 ml/kg。检测大鼠心肌Bax、Bcl-2蛋白的表达,并对Bax/Bcl-2蛋白比值与心肌细胞凋亡率进行相关性分析。结果与C组比较,E组Bax蛋白表达上调,Bcl-2蛋白表达下调,Bax/Bcl-2蛋白比值升高。A组、IB组和IS组Bax、Bcl-2蛋白表达上调,Bax/Bcl-2蛋白比值升高（P〈0.05）。与E组比较,A组、IB组和IS组Bax蛋白表达下调,Bcl-2蛋白表达上调,Bax/Bcl-2蛋白比值降低（P〈0.05）。各组Bax/Bcl-2蛋白比值与心肌细胞凋亡率呈正相关（r=0.727,P〈0.01）。结论山莨菪碱、旋覆花素和苦碟子预先给药可通过下调过度训练大鼠心肌促凋亡蛋白Bax、上调抗凋亡蛋白Bcl-2的表达,抑制心肌细胞凋亡。     

过度训练可通过破坏Bax/Bcl-2平衡激活caspase依赖的凋亡通路诱导大鼠肾小管上皮细胞凋亡

目的 观察过度训练大鼠肾组织Bax、Bcl-2及 caspase-3的表达及其与肾小管上皮细胞凋亡的关系,探讨caspase依赖的凋亡信号途径在其中的作用及其机制。 方法 将48只雄性Wistar大鼠按随机数字表法分为对照组（CN）、力竭运动组（ES）、旋覆花素干预组（IB）。CN组为安静对照;ES组又根据力竭后恢复时间分为力竭后即刻（ESI）、力竭后6 h（ES 6 h）和力竭后24 h（ES 24 h）组;IB组于力竭运动前24 h 给予旋覆花素25 ml/kg分3次灌胃后进行力竭运动,分为IB 6 h和IB 24 h组。采用大鼠游泳至力竭建立过度训练模型。TUNEL法检测肾小管上皮细胞凋亡。免疫组织化学法检测肾组织Bax、Bcl-2及 caspase-3的表达。Western印迹法测定肾组织caspase-3蛋白的表达。用图像分析系统测定肾小管凋亡细胞、Bax、Bcl-2及 caspase-3表达的平均吸光度并计算Bax和Bcl-2的比值。用Pearson法分析Bax和Bcl-2的比值与caspase-3之间的相关性。用非参Spearman法分析Bax/Bcl-2的比值和caspase-3与细胞凋亡之间的相关性。 结果 TUNEL法显示,过度训练大鼠肾组织凋亡细胞主要分布在肾小管上皮细胞,力竭后即刻、6 h及24 h肾小管上皮细胞凋亡数呈进行性增多（P < 0.01）;免疫组化显示,过度训练大鼠肾组织caspase-3的表达及分布与Bax/Bcl-2比值变化及凋亡细胞的分布一致。图像分析显示,大鼠肾小管上皮细胞Bax/Bcl-2比值与caspase-3的表达于力竭后即刻、力竭后6 h、力竭后24 h逐渐增高（均P < 0.05）,均显著高于对照组（均P < 0.05）。Western 印迹测定结果也显示caspase-3蛋白表达的变化趋势。过度训练大鼠肾小管上皮细胞Bax/Bcl-2比值与caspase-3的表达呈正相关（r = 0.865,P < 0.05）;Bax/Bcl-2比值和caspase-3的表达与肾小管上皮细胞凋亡之间均呈正相关（r = 0.674,r = 0.837,均P < 0.05）。用旋覆花素干预后,过度训练引起的肾小管上皮细胞Bax/Bcl-2比值增高和caspase-3的过度表达及肾小管上皮细胞的过度凋亡均被显著抑制（均P < 0.05）。 结论 过度训练可通过破坏肾小管上皮细胞Bax/Bcl-2的平衡,激活caspase依赖的凋亡信号通路,进而诱导大鼠肾小管上皮细胞凋亡。这可能是过度训练引起肾小管上皮细胞凋亡的分子机制之一。     

山莨菪碱、旋覆花素、苦碟子对过度训练大鼠肾细胞凋亡的影响

目的 评价山莨菪碱、旋覆花素、苦碟子对过度训练大鼠肾细胞凋亡的影响。方法 雄性Wistar大鼠72只，体重200-220g，随机分为5组：正常对照组（C组，n=8）、力竭对照组（E组，n= 16）、山莨菪碱组（A组，n=16）、旋覆花素组（IB组，n=16）、苦碟子组（IS组，n=16）。采用游泳至力竭建立过度训练动物模型。A组于力竭前即刻腹腔注射山莨菪碱10 mg／kg，IB组于力竭前24 h及力竭前即刻胃肠灌入旋覆花素25 ml／kg，IS组于力竭前即刻腹腔注射苦碟子20 ml／kg，力竭后6、24 h处死大鼠取肾脏标本，采用流式细胞术及TUNEL法检测肾细胞凋亡，并计算肾细胞凋亡率。结果 与C组比较，E组、A组、IB组和IS组力竭后6、24 h肾细胞凋亡率升高（P〈0.05或0．01）;与E组比较，A组、IB组和IS组力竭后6、24 h肾细胞凋亡率降低（P〈0．05）。结论 山莨菪碱、旋覆花素及苦碟子预先给药可减轻过度训练诱发大鼠肾细胞凋亡。     

山莨菪碱对过度训练致急性心肌损伤大鼠caspase-1和IL-18表达的影响

目的 评价山莨菪碱对过度训练致急性心肌损伤大鼠caspase-1和IL-18表达的影响.方法 健康雄性Wistar大鼠48只,体重200～ 220 g,采用随机数字表法,将其随机分为3组:对照组(C组,n=8)、力竭运动组(ES组,n=24)和山莨菪碱组(AD组,n=16).采用游泳力竭法建立过度训练致大鼠急性心肌损伤模型.AD组于力竭运动前20 min腹腔注射山莨菪碱10 mg/kg.ES组于力竭后即刻、6、24 h时,AD组于力竭后6、24 h时分别随机取8只大鼠,采集下腔静脉血样,采用ELISA法检测血清心肌肌钙蛋白I(cTnl)浓度,随后处死大鼠取心肌组织,采用免疫组化法检测caspase-1及IL-18的表达水平,光镜下观察病理学结果.结果 与C组比较,ES组各时点血清cTnI浓度升高,心肌组织caspase-1和IL-18表达上调(P＜0.05);与ES组比较,AD组各时点血清cTnI浓度降低,心肌组织caspase-1和IL-18表达下调(P＜0.05).AD组心肌病理学损伤程度轻于ES组.结论 山莨菪碱可减轻过度训练致大鼠急性心肌损伤,其机制与下调心肌组织caspase-1及IL-18表达有关.     

山莨菪碱、旋覆花素、苦碟子对过度训练致急性心肌损伤大鼠的影响

目的探讨山莨菪碱、旋覆花素、苦碟子对过度训练致急性心肌损伤大鼠的影响。方法雄性Wistar大鼠80只,体重200～220 g,随机分为5组:正常对照组(C组,n=8)、力竭对照组(E组, n=24)、山莨菪碱组(A组,n=16)、旋覆花素组(IB组,n=16)、苦碟子组(IS组,n=16)。采用游泳致力竭建立过度训练动物模型。A组于力竭前即刻腹腔注射山莨菪碱10 mg/kg,IB组于力竭前24 h和力竭前即刻口腔灌入旋覆花素25 ml/kg,IS组于力竭前即刻腹腔注射苦碟子20 ml/kg。取标本检测大鼠血清磷酸肌酸激酶(CK)及其同工酶(CK-MB)的活性,光镜观察心肌组织形态学,采用流式细胞术及TUNEL法检测大鼠心肌细胞凋亡,并计算心肌细胞凋亡率。结果与C组比较,E组、A组、IB组和IS组血清CK及CK-MB升高,心肌细胞凋亡率升高(P<0.05);与E组比较,A组、IB组及IS组大鼠血清CK及CK-MB及心肌细胞凋亡率均降低(P<0.05)。光镜下,E组的心肌细胞核深染,有固缩现象;而A组、IB组及IS组的心肌心肌组织学变化均未见异常。结论山莨菪碱、旋覆花素、苦碟子预先给药通过抑制心肌细胞的凋亡,可减轻过度训练致大鼠的心肌损伤。     

山莨菪碱与旋覆花素及苦碟子对过度训练大鼠肾组织上皮钙黏素表达的影响

目的：探讨过度训练大鼠肾组织上皮钙黏素表达的变化及山莨菪碱、旋覆花素、苦碟子干预的影响。方法：将80只雄性Wistar大鼠随机分为安静对照组（CN）、力竭运动组（ES）、山莨菪碱干预组（AD）、旋覆花素干预组（IB）、苦碟子干预组（IS）。CN组为安静对照;ES组又根据力竭后恢复时间分为力竭即刻（ESI）、力竭后6h（ES6h）和力竭后24h（ES24h）;AD组、IB组、IS组均分别于力竭后6h和力竭后24h4取材观察各项指标。每个时间点8只大鼠。采用大鼠游泳至力竭建立过度训练模型。采用免疫组织化学法检测各组肾组织E-Cadherin蛋白表达的变化;采用CMIAS病理图像分析仪测量E-Cadherin蛋白表达的平均光密度。结果：对照组大鼠肾组织有E-Cadherin的丰富表达,广泛分布于肾小管上皮细胞膜上及细胞浆内;力竭即刻、6h及24hE-Cadherin表达逐渐减弱（P〈0.05）。山莨菪碱、旋覆花素和苦碟子组大鼠肾组织E-Cadherin表达比同期力竭组明显增强（P〈0.05）。结论：过度训练可引起肾组织E-Cadherin的表达下调,山莨菪碱、旋覆花素和苦碟子干预后可逆转这种变化,这可能是过度训练引起急性肾损伤及上述3种药物减轻OTIAKI的重要机制之一。     

中性粒细胞明胶酶相关脂质运载蛋白对大鼠肾脏缺血再灌注损伤肾小管上皮细胞的保护作用

目的 探讨中性粒细胞明胶酶相关脂质运载蛋白(NGAL)对大鼠缺血再灌注损伤肾脏肾小管上皮细胞凋亡的保护作用及机制.方法 建立大鼠肾脏缺血再灌注模型,雄性SD大鼠随机分为对照组、缺血再灌注模型组、NGAL组 ;HE染色观察3组大鼠肾组织病理变化 ;TUNEL法检测肾小管上皮细胞凋亡 ;实时定量PCR、Western印迹法检测凋亡蛋白fas、bcl-2的表达变化.结果 与缺血再灌注模型组比较,NGAL组肾小管上皮细胞凋亡数量显著减少[(8.6±3.4)/HP比(20.8±3.7)/HP,P＜0.05] ;NGAL组肾组织fas mRNA(2.34±0.51比6.84±2.34,P＜0.05)、fas蛋白(0.65±0.05比0.95±0.08,P＜0.05)表达显著下调,bcl-2蛋白(0.33±0.05比0.24±0.03,P＜0.05)表达显著上调,但bcl-2 mRNA表达无明显改变.结论 NGAL对大鼠缺血再灌注损伤肾小管上皮细胞有保护作用,其作用可能与减少细胞凋亡、改变凋亡蛋白的表达有关.     

过度训练致大鼠肾组织黏附分子表达的改变及东莨菪碱干预的影响

目的 研究过度训练致肾组织黏附分子表达的改变及东莨菪碱的保护作用.方法 采用大鼠游泳至力竭建立过度训练致急性肾损伤模型.将大鼠随机分为7组,即安静对照组、力竭运动后即刻组、力竭运动后6 h组、力竭运动后12 h组、力竭运动后24 h组、山莨菪碱6 h组、山茛菪碱24 h组,用全自动生化仪检测各组大鼠血BUN、Scr、CK及尿r-GT的改变;光镜观察各组肾组织结构的改变;免疫组织化学方法 检测各组大鼠肾组织ICAM-1、E-Cadherin表达,运用免疫组化分析软件对所选视野内阳性信号进行图像分析.结果 力竭后即刻组大鼠血BUN、CK升高0.05).光镜下力竭后即刻组大鼠肾组织结构仅见部分肾小球囊及肾小管扩张,在皮髓质交界处及髓质小血管内可见大量红细胞堆积,力竭12 h大鼠可见肾小管上皮细胞刷状缘不规整,部分脱落,肾小管管腔内可见颗粒管型和透明管型.应用东莨菪碱后.力竭后6 h及24 h血BUN、Cr、CK及尿r-GT均明显降低(P<0.05),肾组织结构改善.力竭运动组肾脏皮质区及髓质区ICAM-1表达随力竭后恢复时问延长呈进行性增高,E-Cadhefin表达则呈进行性减弱;各力竭组与正常对照组之间均有明显差异(P<0.01);东茛菪碱可明显降低力竭运动后ICAM-1表达,与同时段力竭运动组相比有明显差异(P<0.01),与正常对照组之间则无明显差异(P>0.05).东莨菪碱可增强E-Cadhefin的表达,与同时段力竭运动组有明显差异(P<0.01),与正常对照组无明显差异(P>0.05).结论 过度训练可引起急性肾损伤,肾组织黏附分子表达的变化是过度训练致急性肾损伤的重要发病机制,东莨菪碱能减轻过度运动造成的肾组织损伤,下调ICAM-1表达,增强钙黏附分子及其连接素的表达,维持了细胞正常黏附联结的存在,改善了过度训练时异常的血流动力学状态,发挥了明显的肾脏保护作用.     

山莨菪碱对大鼠急性肾损伤时内质网应激的影响

目的 评价山莨菪碱对大鼠急性肾损伤时内质网应激(ERS)的影响.方法 雄性SD大鼠42只,体重200 ～ 220 g,采用随机数字表法将其分为3组:对照组(C组,n=6),双侧后肢肌肉注射生理盐水10 ml/kg;急性肾损伤组(AKI组,n=18),双侧后肢肌肉注射50％ (v/v)甘油10 ml/kg;山莨菪碱组(AD组,n=18),腹腔注射山莨菪碱10 mg/kg,20 min后处理同AKI组.C组于肌肉注射生理盐水后即刻(T0),AKI组和AD组于甘油给药后1 h(T1)、6 h(T2)、24 h(T3)分别随机取6只大鼠,采集肾组织标本,HE染色后行肾小管损伤评分,采用免疫组化和Western blot法测定肾组织葡萄糖调节蛋白78(GRP78)和氧调节蛋白150(ORP150)表达.结果 与C组比较,AKI组和AD组各时点肾小管损伤评分升高,肾组织GRP78和ORP150表达上调(P＜0.01);与AKI组比较,AD组各时点肾小管损伤评分降低,肾组织GRP78和ORP150表达下调(P＜0.05或0.01).结论 山莨菪碱可抑制肾小管上皮细胞ERS,可能减轻了ERS途径诱导的细胞凋亡,从而减轻了大鼠急性肾损伤.     

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.     

A Teaspoon Pump for Pumping Blood with High Hydraulic Efficiency and Low Hemolysis Potential

Abstract: Virtually all blood pumps contain some kind of rubbing, sliding, closely moving machinery surfaces that are exposed to the blood being pumped. These valves, internal bearings, magnetic bearing position sensors, and shaft seals cause most of the problems with blood pumps. The original teaspoon pump design prevented the rubbing, sliding machinery surfaces from contacting the blood. However, the hydraulic efficiency was low because the blood was able to "slip around" the rotating impeller so that the blood itself never rotated fast enough to develop adequate pressure. An improved teaspoon blood pump has been designed and tested and has shown acceptable hydraulic performance and low hemolysis potential. The new pump uses a nonrotating "swinging" hose as the pump impeller. The fluid enters the pump through the center of the swinging hose; therefore, there can be no fluid slip between the revolving blood and the revolving impeller. The new pump uses an impeller that is comparable to a flexible garden hose. If the free end of the hose were swung around in a circle like half of a jump rope, the fluid inside the hose would rotate and develop pressure even though the hose impeller itself did not "rotate"; therefore, no rotating shaft seal or internal bearings are required.     

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.     

Tissue perfusion in relation to cardiac output during continuous positive-pressure ventilation and administration of propranolol or verapamil

Background : Our objective was to determine whether administration of propranolol or verapamil modifies the hemodynamic adaptation to continuous positive-pressure ventilation (CPPV), in particular the regional distribution of cardiac output (CO).
Methods : General hemodynamics and regional blood flows assessed by microsphere technique (15 (μm) were recorded in 16 anesthetized pigs during spontaneous breathing (SB) and CPPV with 8 cm H₂O end-expiratory pressure (CPPV8) before and after intravenous administration of propranolol (0.3 mg · kg⁻¹ followed by 0.15 mg · kg⁻¹ · h⁻¹, n=8) or verapamil (0.1 mg · kg⁻¹ followed by 0.3 mg · kg⁻¹ · h⁻¹, n=8).
Results : CPPV8 depressed CO by 25% without shifts in its relative distribution with the exception of a noteworthy increase in adrenal perfusion. Propranolol increased arterial blood pressure, and due to a fall in heart rate, CO dropped by 25%. The kidneys and, to a lesser extent, the splanchic region and central nervous system received increased fractions of the remaining CO at the expense of skeletal muscle flow. Similar patterns were seen during SB and CPPV8 such that the combination of propranolol and CPPV8 depressed CO by 50%. The circulatory effects of verapamil were less evident but myocardial perfusion tended to increase.
Conclusions : The combination of propranolol or verapamil with CPPV does not result in any specific hemodynamic interaction in anesthetized pigs, except that the combined effect of propranolol and CPPV may severely reduce CO.     

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.     

Volatile anaesthetics reduce adhesion of blood platelets under low-flow conditions in the coronary system of isolated guinea pig hearts

Background : Inhibitory effects of volatile anaesthetics on platelet aggregation have been demonstrated in several studies. However, the influence of volatile anaesthetics on intracoronary platelet adhesion has not been elucidated so far.
Methods : Isolated hearts of guinea pigs were perfused with buffer in the absence or presence of volatile anaesthetics (0.5 and 1 MAC) at constant coronary flow rates of 5 ml/min for 25 min, then 1 ml/min for 30 min and again 5 ml/min for 10 min. Before, during and after low-flow perfusion, a bolus of human platelets was applied into the coronary system. To simulate thrombogenic conditions, 0.3 U/ml human thrombin was infused during low-flow perfusion and reperfusion. The number of platelets sequestered to the endothelium was calculated from the difference between coronary in- and output of platelets. The myocardial production of lactate and consumption of pyruvate and coronary perfusion pressure were also determined.
Results : At a flow rate of 5 ml/min only about 3% of the applied platelets did not emerge from the coronary system, in any group. In contrast, 13.1±1.2% (mean±SEM) of infused platelets became adherent in low-flow perfusion in the control group without anaesthetic. The adherence was reduced with each 1 MAC isoflurane (to 6.2±1.2%), sevoflurane (to 4.4±0.9%) or halothane (to 3.2±1.5%) (each P <0.05 vs. control). Volatile anaesthetic, 0.5 MAC, did not inhibit platelet adhesion to a statistically significant extent in any case. Perfusion pressure and metabolic parameters were not statistically different between the control and the hearts exposed to anaesthetics.
Conclusion : Volatile anaesthetics in a concentration of 1 MAC can reduce the adhesion of platelets in the coronary system under reduced flow conditions. This action does not arise from vasodilation or inhibition of ischaemic stress.     

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.