盐酸戊乙奎醚对大鼠横纹肌溶解致急性肾损伤肾脏细胞凋亡的作用研究

目的:探究盐酸戊乙奎醚对大鼠横纹肌溶解致急性肾损伤时细胞凋亡影响。方法:将42只SD大鼠按随机数字表法分为对照组(C组)、急性肾损伤组(AKI组),盐酸戊乙奎醚干预组(PHC组)。采用甘油肌注法建立横纹肌溶解致大鼠急性肾损伤模型。速率法检测血清BUN、Cr水平;HE染色法观测肾组织病理学变化并行肾小管损伤评分;TUNEL法检测肾细胞凋亡情况并计算凋亡率;Western Blot法检测肾组织PTEN蛋白表达。结果:AKI 6 h、24 h组血清BUN、Cr水平高于C组(P0.01);PHC 6 h、24 h组血清BUN、Cr水平低于AKI组(P0.05、P0.01)。AKI组各时点肾小管损伤评分高于C组(P0.01);PHC组各时点肾小管损伤评分低于AKI组(P0.05、P0.01);AKI组各时点肾细胞凋亡率高于C组(P0.01);PHC组6 h、24 h肾细胞凋亡率低于AKI组(P0.05、P0.01)。AKI组各时点肾组织PTEN蛋白表达强于同期C组(P0.01);PHC组各时点肾组织PTEN蛋白表达弱于同期AKI组(P0.05、P0.01)。结论:盐酸戊乙奎醚可通过下调PTEN表达、抑制细胞凋亡来发挥肾脏保护作用。     

山莨菪碱对横纹肌溶解致急性肾损伤大鼠肾组织内HO-1表达及肾功能的影响

目的:观察横纹肌溶解致急性肾损伤大鼠肾功能指标、血浆Mb、MDA、肾组织HO-1表达的变化,以及山莨菪碱对上述指标的影响。方法:将42只大鼠随机分为对照组(CN)、模型组(AKI)、山莨菪碱组(AD)。采用甘油肌注法建立横纹肌溶解致急性肾损伤大鼠模型。血生化分析法检测血浆BUN、Cr、CK;硫代巴比妥酸法检测血浆MDA;ELISA法检测血浆Mb;免疫组织化学法和WesternBlot法检测肾组织中HO-1的表达。结果:AKI组血浆BUN、Cr、MDA、CK、Mb与CN组相比明显升高(P<0.05、P<0.01);AD组1、6、24h血浆BUN均显著低于同期AKI组(P<0.05、P<0.01);AD24h组血浆Cr明显低于同期AKI组(P<0.01);AD6h、AD24h组血浆MDA明显低于同期AKI组(P<0.01);AD组1、6h血浆CK明显低于同期AKI组(P<0.05、P<0.01);AD24h组血浆Mb显著低于同期AKI组(P<0.05)。免疫组化和Western Blot结果显示,AKI6h组及AKI24h组HO-1表达均显著强于CN组(P<0.01);AD6h组、AD24h组HO-1表达均显著高于同期AKI组(P<0.01)。血浆Mb水平与BUN、Cr呈显著正相关(r=0.872,P=0.000;r=0.716,P=0.000);血浆MDA水平与HO-1/GAPDH比值呈显著正相关(r=0.884,P=0.000)。结论:山莨菪碱可通过减少Mb的产生、上调肾组织内HO-1的表达以及抑制氧化应激反应发挥其肾脏保护作用。     

内质网应激相关凋亡途径参与单侧输尿管梗阻大鼠肾间质纤维化

目的 探讨内质网应激（ERS）相关凋亡途径在单侧输尿管梗阻（UUO）大鼠肾间质纤维化发生、发展中的作用。 方法 健康雄性Wistar大鼠25只,按随机数字表法分为UUO模型组（n=18）和假手术组（n=7）,UUO模型组行左侧输尿管结扎术,假手术组仅分离输尿管不结扎,分别于术后3 d、7 d、14 d处死各组大鼠,行HE和Masson染色,观察肾脏病理变化;比色法测定肾组织羟脯氨酸（HYP）含量;免疫组化法检测α平滑肌肌动蛋白（α-SMA）;原位末端标记法（TUNEL）与DNA电泳观察肾小管间质细胞凋亡情况;RT-PCR法检测梗阻侧肾组织ERS相关分子葡萄糖调节蛋白78（GRP78）mRNA表达变化;Western印迹法分析凋亡相关蛋白半胱氨酸天门冬氨酸蛋白酶3（caspase-3）和GRP78的蛋白表达变化。 结果 与假手术组比较,UUO模型组肾脏病理改变加重,肾间质纤维化程度随梗阻时间延长逐渐加重,肾组织HYP含量显著升高（P < 0.05）,肾组织α-SMA也在肾小管间质细胞广泛表达,TUNEL染色及DNA琼脂糖凝胶电泳提示大量的肾小管间质细胞凋亡。UUO模型组GRP78 mRNA表达于术后3 d即发生显著上调,而蛋白表达在术后7 d开始出现显著变化,与假手术组差异均有统计学意义（均P < 0.01）;在此后观察期间内GRP78 mRNA和蛋白均持续高水平表达。模型组大鼠肾组织caspase-3的蛋白表达在UUO术后3 d即有显著上调（P < 0.05）,且随着梗阻时间延长进行性升高,于术后7 d、14 d增多更为显著,与假手术组差异均有统计学意义（P < 0.05）。相关分析显示GRP78蛋白表达与肾组织HYP含量和caspase-3蛋白表达均呈正相关（r = 0.657,P < 0.01;r = 0.714,P < 0.01）。 结论 UUO早期即可诱导ERS标志蛋白表达变化,触发ERS。长期ERS可诱导肾小管间质细胞凋亡;caspase-3介导的ERS相关凋亡途径可能参与了肾间质纤维化过程。     

山莨菪碱对顺铂诱导的急性肾损伤大鼠TLR4/NF-κB信号通路的调节作用研究

目的:研究山莨菪碱对顺铂诱导的急性肾损伤大鼠Toll样受体(TLR4)/核因子κB(NF-κB)信号通路的调节作用。方法:90只大鼠随机分为正常对照组、急性肾损伤组、山莨菪碱低、中、高剂量组以及阳性对照组,除正常对照组外,其余大鼠腹腔注射顺铂建立急性肾损伤大鼠模型,山莨菪碱低、中、高剂量组分别按照2.5 mg/kg、5 mg/kg、10 mg/kg腹腔注射给予大鼠山莨菪碱,阳性对照组腹腔注射1.0 mg/kg安磷汀,正常对照组及急性肾损伤组给予生理盐水,1次/d,连续14 d。使用ELISA试剂盒测定大鼠24 h尿蛋白量、尿N-乙酰-β-D-氨基葡萄糖苷酶(NAG)水平、血清尿素氮(BUN)及肌酐(Cr)水平,苏木精-伊红(HE)染色法对大鼠进行肾组织病理学检查,实时定量PCR(RT-PCR)法检测大鼠肾组织TLR4及NF-κBp65 mRNA水平,免疫印迹(Western blot)法测定大鼠肾组织TLR4及NF-κBp65蛋白水平。结果:山莨菪碱低、中、高剂量组大鼠24 h尿蛋白量、尿NAG水平、血清BUN及Cr水平、肾组织TLR4及NF-κBp65 mRNA水平、肾组织TLR4及NF-κBp65蛋白水平较急性肾损伤组大鼠均降低,差异有统计学意义(P0.05),且各项指标变化与山莨菪碱剂量表现出依赖性,同时山莨菪碱各剂量组大鼠肾组织病理学明显改善。结论:山莨菪碱能够缓解顺铂诱导的大鼠急性肾损伤状态,改善大鼠肾组织病理学,其机制可能与调节TLR4/NF-κB信号通路有关。     

Caspase-1选择性抑制剂VX-765在大鼠急性肾损伤相关性肺损伤中的作用

目的评价caspase-1选择性抑制剂VX-765在大鼠急性肾损伤(AKI)相关性肺损伤中的作用。方法 SPF级SD雄性大鼠72只,9～10周龄,体重350～400 g。采用随机数字表法分为四组:假手术组(S组)、AKI组(A组)、DMSO+AKI组(D组)和VX-765+AKI组(V组),每组18只。S组暴露双肾45 min; A组采用切除右肾、夹闭左肾肾蒂45 min的方法建立AKI模型;D组建立AKI模型前经鼠尾静脉注射2%DMSO 0.5 ml/kg; V组建立AKI模型前经鼠尾静脉注射10%VX-765 0.5 ml/kg。AKI模型建立24 h后取主动脉血样,采用酶偶联速率法与肌氨酸氧化酶法检测血清尿素氮(BUN)和肌酐(Scr)浓度,ELISA法检测血清IL-1β和IL-18浓度。随后处死大鼠取左肾组织和左肺组织。采用免疫荧光法检测肾组织caspase-1/DAPI双阳性细胞百分比,Western blot法检测肾组织cleaved GSDMD蛋白及肺组织ZO-1蛋白含量,Paller评分法评估HE染色后的肾小管损伤情况,烘干法检测肺部干湿比重,计算肺含水率,ELISA法检测肺伊文斯蓝评估肺血管通透性,肺损伤评分评估MASSON染色后的肺组织损伤程度。结果与S组比较,A组、D组、V组血清BUN、Scr、IL-1β和IL-18浓度明显升高,肾组织caspase-1/DAPI双阳性细胞百分比明显升高,肾组织caspase-1和cleaved GSDMD蛋白含量明显升高,肾损伤Paller评分明显升高,肺组织ZO-1蛋白含量明显降低,肺含水率、肺血管通透性、肺损伤评分明显升高(P0.05)。与A组比较,V组血清BUN、Scr、IL-1β和IL-18浓度明显降低,肾组织caspase-1/DAPI双阳性细胞百分比明显降低,肾组织caspase-1和cleaved GSDMD蛋白含量明显降低,肾损伤Paller评分明显降低,肺组织ZO-1蛋白含量明显升高,肺含水率、肺血管通透性、肺损伤评分明显降低(P0.05)。A组、D组各指标差异无统计学意义。结论Caspase-1选择性抑制剂VX-765可以降低血清中BUN、Scr、IL-1β和IL-18浓度,减少肾组织细胞焦亡,改善肺水肿及肺血管通透性,减轻AKI相关性肺损伤。     

虎杖苷对脓毒症急性肾损伤大鼠炎症反应和氧化应激的影响

目的观察虎杖苷在脓毒症急性肾损伤(acute kidney injury,AKI)大鼠中的抗炎和抗氧化应激作用。方法 SD大鼠72只,体重180~220g,随机分为四组:假手术对照组(Sham组);盲肠结扎穿刺术(CLP)+生理盐水组(CN组);CLP+溶媒组(CV组);CLP+虎杖苷组(CD组),每组18只。对CN、CV和CD组大鼠施行CLP,模拟脓毒症AKI动物模型,Sham组大鼠盲肠既不被结扎也不被穿孔,余步骤则与CLP组相同,未行其他任何处理。CLP术后6、12、18h,CN、CV和CD组经大鼠尾静脉分别注射生理盐水、溶媒、虎杖苷30 mg/kg。在CLP术后24h记录血清肌酐(Cr)和尿素氮(BUN)等肾功能指标,观察肾脏组织病理形态改变并进行肾小管损伤评分,检测血清TNF-α、IL-1β和IL-6浓度,测定肾组织中超氧化物歧化酶(SOD)活性和丙二醛(MDA)、谷胱甘肽(GSH)浓度。结果与Sham组比较,CN组和CV组血清Cr、BUN、TNF-α、IL-1β和IL-6浓度、肾小管损伤评分和肾组织MDA浓度明显升高(P0.01),肾组织SOD活性、GSH浓度明显降低(P0.01)。与CN组和CV组比较,CD组血清Cr、BUN、IL-1β和IL-6浓度、肾小管损伤评分和肾组织MDA浓度明显降低(P0.05),肾组织SOD活性、GSH浓度明显升高(P0.05)。结论盲肠结扎穿刺术导致的脓毒症可引起急性肾损伤,虎杖苷可通过显著的抗炎和抗氧化应激作用,减轻肾组织损伤,改善肾功能。     

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.     

银杏内酯对急性肾损伤大鼠的保护作用及机制研究

目的探讨银杏内酯对急性肾损伤(acute kidney injury,AKI)大鼠的保护作用及对肾组织中腺苷酸激活蛋白激酶(AMP-activated protein kinase,AMPK)及沉默信息调节因子(silent information regulator 1,SIRT1)通路的影响。方法 SD大鼠随机分为正常对照组(Control组)、AKI组和银杏内酯低(2.5 mg/kg)、中(5 mg/kg)、高(7.5 mg/kg)剂量组,每组10只。除Control组经皮下注射生理盐水外,其余各组大鼠均经皮下注射庆大霉素80 mg/kg,6 d,1次/d,建立AKI模型后,Control组、AKI组经腹腔给予生理盐水,银杏内酯各剂量组经腹腔给予相应剂量药物,1次/d,共给药14 d。末次给药1 h后,收集各组大鼠血液、尿液后处死大鼠,取肾组织标本,用酶联免疫吸附法检测肾功能指标血清肌酐(Scr)、血清尿素氮(BUN)、血清炎性因子白细胞介素-6(IL-6)和肿瘤坏死因子-α(TNF-α)及尿液中中性粒细胞明胶酶相关脂质运载蛋白(NGAL)和肾损伤因子1(KIM-1)含量;用苏木精-伊红染色(HE)检测各组大鼠肾组织病理变化;以试剂盒检测肾组织氧化应激反应物超氧化物歧化酶(SOD)、丙二醛(MDA)含量;凝胶电泳迁移率转变分析法检测肾脏组织NF-κB活性;蛋白免疫印迹法检测肾组织pAMPK/AMPK、SIRT1蛋白表达情况。结果与Control组相比,AKI组大鼠可见肾小管上皮细胞崩解脱落、空泡变性等病理损伤,Scr、BUN、NGAL、KIM-1含量、肾组织TNF-α、IL-6、MDA含量及NF-κB活性均明显升高(P0.05),肾组织SOD活性、pAMPK/AMPK、SIRT1蛋白表达量明显下降(P0.05)。与AKI组相比,银杏内酯高、中、低剂量组肾小管病理损伤减轻,Scr、BUN、NGAL、KIM-1、TNF-α、IL-6、MDA含量及NF-κB活性均明显降低(P0.05),SOD活性、pAMPK/AMPK、SIRT1蛋白表达量明显升高(P0.05)。与银杏内酯低剂量组比较,中、高剂量组肾小管病理损伤减轻,Scr、BUN、NGAL、KIM-1、TNF-α、IL-6、MDA含量及NF-κB活性均明显降低(P0.05),SOD活性、pAMPK/AMPK、SIRT1蛋白表达量明显升高(P0.05)。结论银杏内酯可能通过激活AMPK/SIRT1通路,减轻肾脏氧化应激和炎性损伤,改善AKI大鼠病理损伤。     

STF-083010对肾脏缺血-再灌注损伤的保护作用

目的 观察STF083010对急性肾缺血-再灌注损伤的作用,探讨其损伤保护作用的机制.方法 选择健康雄性SD大鼠30只,随机分为假手术组(打开腹腔)、I-R组(建立大鼠肾I-R损伤模型)与STF083010组.分别在缺血-再灌注24h后处死大鼠,取血液和肾组织.全自动生化仪检测各组血清尿素氮(BUN)及肌酐(Scr)水平.PAS染色观察大鼠肾组织病理变化,免疫组化检测肾脏组织中XBP1、GRP78蛋白的表达.Quantitative real-time PCR(QPCR)测定大鼠肾组织标本中XBP1、GRP78 mRNA水平.结果 I-R组肌酐、尿素氮水平与假手术组相比差异均有统计学意义(P＜0.05).STF-083010组与I-R组相比,差异亦有统计学意义(P＜0.05).PAS病理图片可见STF-083010组肾小管损伤较I-R组明显减轻(P＜0.05);免疫组化检测显示STF-083010组XBP1的表达较I-R组明显降低(P＜0.05),STF-083010组GRP78蛋白的表达较I/R组明显升高;QPCR结果显示STF-083010组XBP1 mRNA水平较I-R组明显降低(P＜0.05),STF-083010组GRP78 mRNA较I-R组明显升高(P＜0.05).结论 STF-083010可以对大鼠肾脏缺血-再灌注损伤性保护作用.     

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.     

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.     

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.     

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.     

Immunomodulation in Transplantation with Photopheresis

Abstract: Photopheresis is a technique in which peripheral blood mononuclear cells, in the presence of a photoacti-vatable compound, are exposed extracorporeally to ultraviolet A light and reinfused, inducing a host autoregula-tory immune response. Experimental work and ongoing clinical studies are helping to define the role of this novel, safe, and non-toxic immunomodulating technology in the field of transplantation.