肿瘤坏死因子相关凋亡诱导配体及其受体在烧伤大鼠胸腺组织中的表达

目的 了解肿瘤坏死因子（TNF）相关的凋亡诱导配体（TRAIL）及其受体在严重烧伤大鼠胸腺组织细胞异常凋亡中的作用。方法 将50只Wistar大鼠随机分为假伤组（模拟烧伤）lO只和烧伤组40只（设伤后4、12、24、48h 4个时相点）。应用膜联蛋白A5-异硫氰酸荧光素／碘化丙啶双染法，观察大鼠胸腺组织中细胞凋亡的情况；反转录-聚合酶链反应和蛋白质印迹法检测TRAIL的死亡受体5（DR5）、DR4、诱骗受体1（DcR-1）、DcR2在大鼠胸腺组织中的表达。结果 与假伤组大鼠细胞凋亡率[（6．7±0．8）％]比较，烧伤组于伤后4h[（17．1±0．4）％]起增高，12h时[（25．2±1．1）％]达高峰，48h时仍明显高于假伤组（P〈0．05）。烧伤组大鼠胸腺组织中DR5的表达显著高于假伤组，DcR2的表达则显著低于假伤组；其余受体的表达组间相似。结论 严重烧伤后早期大鼠胸腺组织的细胞凋亡明显增加，且胸腺组织中DR5和DcR2的表达异常，提示TRAIL凋亡途径可能参与了病理性细胞凋亡过程。     

靶向survivin的siRNA联合凋亡相关配体对肝癌细胞的影响

目的探讨靶向survivin的siRNA联合肿瘤坏死因子诱导凋亡相关配体(tumor necrosis factor related apoptosis-inducing ligand,TRAIL)对肝癌细胞增殖与凋亡的影响。方法构建靶向survivin基因的siRNA真核表达载体,观察可溶性TRAIL对肝癌细胞增殖与凋亡的影响。结果采用RT-PCR检测显示,siRNA在mRNA水平抑制survivin基因表达为73％。MTT法检测到可溶性TRAIL对HepG2、HepG2／Silence(-)细胞增殖无明显的抑制作用(P>0．05),通过抑制survivin表达,可使HepG2／Silence(+)细胞的12 h存活率明显降低,48 h降至最低[HepG2／Silence(+)0．518±0．017,对照组0．741±0．005,P<0．01]。荧光显微镜检测HepG2／Silence(+)细胞12 h、24 h、48 h的细胞凋亡率分别为:11．85％±0．72％、28．97％±0．43％、41．80％±0．90％,与对照组相比差异有统计学意义(F=22．37,P<0．05)。结论靶向survivin的siRNA在抑制肝癌细胞中survivin表达的同时可增强TRAIL作用的敏感性。     

灵芝孢子粉对2型糖尿病大鼠附睾细胞线粒体Ca~(2+)细胞色素C的影响

目的:研究灵芝孢子粉对2型糖尿病大鼠附睾组织中细胞色素C(Cyt-C)、线粒体Ca2+的影响。方法:青春期Wistar大鼠50只,大鼠尾静脉一次性注射2%链脲佐菌素(STZ)或柠檬酸-柠檬酸钠缓冲液制备2型糖尿病大鼠模型和对照组模型。糖尿病大鼠模型随机分模型组和灵芝组,每组20只,分别给以高脂高糖饮食、高脂高糖+灵芝孢子粉[250mg/(kg.d)],对照组10只,正常饮食。10周后,取双侧附睾,检测附睾细胞线粒体Ca2+、Cyt-C含量。结果:2型糖尿病模型制备成功,模型组附睾细胞线粒体Ca2+含量[(3.279±0.502)mg/L]明显高于对照组[(2.606±0.048)mg/L,P<0.01],灵芝组[(2.693±0.196)mg/L]明显低于模型组(P<0.05),与对照组差异无显著性(P>0.05)。模型组线粒体Cyt-C含量[(3.213±1.511)μmol/L]明显少于对照组[(5.688±1.679)μmol/L,P<0.05],胞质Cyt-C含量[(2.484±0.661)μmol/L]明显高于对照组[(1.574±0.329)μmol/L,P<0.01];灵芝组线粒体Cyt-C含量[(5.258±1.560)μmol/L]高于模型组,但差异无显著性(P>0.05),胞质Cyt-C含量[(1.727±0.396μmol/L]明显低于模型组(P<0.05),与对照组差异无显著性(P>0.05)。结论:2型糖尿病大鼠附睾细胞钙稳态失衡、线粒体有损伤,附睾细胞可能存在细胞凋亡过度。灵芝孢子粉在糖尿病状态下,对附睾组织有保护作用或有对抗细胞凋亡作用。     

L-肉碱对糖尿病大鼠生精细胞凋亡及附睾精子数量和活动率的影响

目的:探讨L-肉碱(LC)对糖尿病(DM)大鼠生精细胞凋亡及附睾精子数量和活动率的影响。方法:24只雄性SD大鼠随机均分为3组,一组作为对照组,剩余两组分别注射链脲佐菌素(STZ,65 mg/kg)建立DM模型。建模成功后,各组大鼠分别给予如下灌胃剂量:对照组:生理盐水;DM模型组:生理盐水;LC组:300 mg/kgLC溶液,连续灌胃6周。末次给药24 h后,麻醉处死所有大鼠,分别进行附睾精子计数并检测精子活动率,流式细胞术检测各组大鼠睾丸生精细胞凋亡情况。结果:用LC治疗后的大鼠附睾头、尾精子活动率(%)分别为53.7±1.8和60.3±1.6,显著高于DM模型大鼠(分别为32.2±2.0和40.5±1.4,P<0.05),但低于对照组大鼠精子活动率63.1±2.4和68.9±1.3。与对照组附睾尾精子相对计数[(37.8±1.1)×106/100 mg]相比,DM组显著减少[(25.5±1.1)×106/100 mg],且具有统计学差异(P<0.05);LC治疗后大鼠附睾尾精子相对计数[(32.0±1.5)×106/100 mg]比DM组显著增加(P<0.05),但仍低于对照组。与对照组生精细胞凋亡率[(3.7±1.3)%]相比,DM组生精细胞凋亡率[(52.5±4.4)%]显著上升(P<0.05);经LC治疗后,LC组大鼠生精细胞凋亡率为(35.3±3.5)%,比DM组显著降低(P<0.05),但仍显著高于对照组。结论:LC(300 mg/kg)灌胃DM大鼠6周,可以减少DM大鼠生精细胞凋亡,增加附睾精子数量,提高精子活动率。     

芦荟提取物对烫伤大鼠创面组织一氧化氮及内皮素含量的影响

目的观察芦荟凝胶和芦荟粗多糖对烫伤大鼠创面组织含水量及一氧化氮(NO)和内皮素(ET)含量的影响。方法将42只Wistar大鼠背部造成4个直径为3 cm的深Ⅱ度烫伤创面。伤后创面分别外敷质量分数5％芦荟粗多糖膏、质量分数10％芦荟凝胶膏、质量分数1％磺胺嘧啶银(SD-Ag)霜和等渗盐水。根据创面用药的不同分为芦荟粗多糖组、芦荟凝胶组、SD-Ag组、等渗盐水组。伤后4、12、24、48 h及7、14、21 d每时相点处死6只大鼠,取创面全层皮肤测定组织含水量、No和ET含量,计算No／ET值。另取6只大鼠不烫伤,作为正常对照组,检测指标同前。结果伤后12、24、48h,芦荟粗多糖组[(73.4±3．8)％、(76．6±3．0)％、(70．6±3．8)％]和芦荟凝胶组[(74.5±2.6)％、(77．1±3．6)％、(71．2±3．1)%]创面组织含水量显著低于SD-Ag组[(80．1±4．1)％、(80．5±3．9)％、(76．1±3．8)％,P<0．05];伤后7-21 d,除SD-Ag组伤后7 d仍显著高于正常对照组(P<0．05)外,其他各组均基本恢复到正常水平。伤后12 h各烫伤组创面组织NO含量升高达峰值,随后下降,到伤后21d仍显著高于正常对照组(P<0．05);伤后12、24 h,芦荟粗多糖组和芦荟凝胶组创面组织NO含量明显低于SD-Ag组及等渗盐水组(P<0．05)。伤后7 d或14 d各烫伤组创面组织ET含量增加达高峰,随后下降;伤后7、14d均显著高于正常对照组(P<0．05)。伤后12 h各组NO／ET值达峰值,随后下降,伤后14 d基本恢复至正常水平,其中芦荟粗多糖组伤后7 d NO／ET值即恢复至正常水乎,但其他3组仍显著高于正常对照组。结论芦荟粗多糖和芦荟凝胶能有效减少烫伤后早期创面组织NO的释放、优化NO／ET值、减轻血管炎性反应、减少渗出和水肿。     

严重烧伤患者休克期降钙素基因相关肽及神经肽Y的变化对心脏功能的影响

目的研究严重烧伤患者休克期降钙素基因相关肽(CGRP)、神经肽Y(NPY)的变化对心脏功能的影响。方法将60例严重烧伤(烧伤总面积32％-96％TBSA)患者设为试验组,常规进行休克期液体复苏和创面处理;另选60例健康志愿者作为对照组。检测试验组患者伤后1、3、6、12、24、48 h和对照组人员血液中CGRP、NPY、心肌肌钙蛋白T(cTnT)的含量,并对其进行相关性分析。结果伤后3 h试验组患者CGRP水平为(28±6)ng／L,较对照组(55±7)ng／L降低,12 h达低谷(15±4)ng／L,伤后48 h仍低于对照组(P<0．05)。伤后1h试验组NPY、cTnT值[(136±20) ng／L、(0．41±0．08)μg/L]较对照组[(86±13)g／L、(0.16±0．06)／μg／L]升高,12 h达峰值[(189±31)ng／L、(1．78±0．47)μg／L],48 h仍高于对照组(P<0．05)。CGRP与cTnT变化呈显著负相关(r=-0.76,P<0．01);NPY与cTnT变化呈显著正相关(r=0．79,P<0．01)。结论血液中CGRP值降低、NPY值升高在严重烧伤休克期心肌损害中可能起着重要作用。     

诱导中性粒细胞凋亡减轻体外循环后肺损伤的体内外实验研究

目的观察诱导中性粒细胞(PMN)凋亡对体外循环(CPB)后肺脏损伤的保护作用。方法在体外实验中,Percoll细胞分离液梯度密度离心得PMN,培养48 h,实验组加入不同浓度的克拉霉素 (5、10、20μg/ml)。台盼蓝染色,镜下观察细胞存活率。流式细胞仪检测细胞凋亡率。免疫组化法观察 PMN凋亡相关基因蛋白Fas和bcl-2的表达情况。在体内实验中,将12只绵羊随机分为低分子右旋糖酐肺动脉灌注组(对照组)和低分子右旋糖酐+克拉霉素肺动脉灌注组(实验组)。建立CPB后经肺动脉灌注肺保护液,CPB 90min后撤离CPB。观察呼吸功能,检测细胞因子浓度,并观察肺组织形态学改变及肺内PMN凋亡情况。结果克拉霉素明显缩短PMN的生存期。流式细胞仪检测显示,实验组24 h凋亡率 1、5、10和20μg/ml浓度组分别为(33．7±4．9)％、(48．0±4．9)％、(52．0±5．4)％和(53．0±7．1)％,明显高于对照组的(31．5±3．5)％(P<0．01);免疫组化染色显示实验组Fas的表达较对照组高,而bcl-2的表达低于对照组(P<0．01);体内实验结果显示,实验组肺血管阻力[(10．22±1．44)kPa·s·L-1]低于对照组 [(20．26±4．71)kPa·s·L-1,P<0．01],而动脉血氧指数[(188±48)mm Hg]较对照组[(123±62)mm Hg, P<0．05]高。实验组支气管肺泡灌洗液内细胞因子白细胞介素-8和肿瘤细胞因子均低于对照组(P< 0．05)。形态学观察表明实验组肺损伤较对照组轻。对照组肺内中性白细胞凋亡率为29％,实验组凋亡率达73％(P<0．01)。结论克拉霉素能诱导PMN凋亡,减轻CPB所造成的肺脏损伤。     

海水浸泡对烫伤大鼠创面炎性反应与愈合的影响

目的观察海水浸泡对烫伤大鼠创面炎性反应及愈合的影响。方法将144只雄性Wistar大鼠随机分为烫伤对照组和海水浸泡组,每组72只,均造成背部10%TBSA浅Ⅱ度烫伤。海水浸泡组大鼠伤后固定四肢,立即用盛海水的方盆浸泡双前肢以下部分,持续4h；烫伤对照组大鼠则用空方盆模拟浸泡过程。于伤后0(即刻,下同)、6、12、24h采用电解质分析仪测定血清中K~+、Na~+、Cl~-的浓度。于伤前及伤后0、6、12h采用酶联免疫吸附测定法检测血清中肿瘤坏死因子(TNF)α及白细胞介索(IL)6的含量。对两组大鼠创面行大体和组织病理学观察,并记录创面愈合时间。结果海水浸泡组大鼠血清中K~+、Na~+、Cl~-的浓度大多高于烫伤对照组。伤后6h海水浸泡组大鼠血清TNF-α、IL-6含量分别为(140±22)、(160±41)ng/L,均明显高于伤前值(29±15)、(62±17)ng/L及烫伤对照组(120±12)、(124±22)ng/L(P＜0．05)。与烫伤对照组比较,海水浸泡组大鼠创面水肿及局部组织炎性反应加重,创面再上皮化和表皮各层的分化延迟；海水浸泡组创面愈合时间为(16．3±1．6)d,明显迟于烫伤对照组(14．1±1．8)d(P＜0．05)。结论大鼠烫伤后经海水浸泡,可加重创面炎性反应,使创面愈合延迟。     

IGF-1、IGF-bp-3在去势大鼠阴茎海绵体中的表达及其意义

目的探讨胰岛素样生长因子-1(IGF-1)、胰岛素样生长因子结合蛋白-3(IGF-BP-3)在去势大鼠阴茎海绵体中的表达及其意义。方法取16只成年雄性大鼠随机分为去势组、对照组。1周后取阴茎海绵体, 比色法测定阴茎海绵体一氧化氮(NO)含量(ΜG／G);原位细胞凋亡标记检测细胞凋亡数;逆转录多聚酶链聚合反应检测IGF-1、IGF-BP-3MRNA表达。结果 IGF-1MRNA在对照组中表达(1．44±0．29)而在去势组未检测到表达。IGF-BP-3MRNA在去势组表达量(3．52±1．4)较对照组(1．10±0．51)升高(P<0．01)。去势组阴茎海绵体细胞凋亡数(26．02±5．25)较对照组(12．51±1．81)高(P<0．05);凋亡细胞积分光密度去势组(33931．54±2459．36)较对照组(18766．37±3040．42)高(P<0．05)。去势组阴茎海绵体 NO浓度(14．45±2．38)较对照组(39．8±3．28)显著降低(P<0．01)。结论去势1周后阴茎海绵体细胞发生凋亡。去势后阴茎海绵体细胞凋亡可能与IGF-1MRNA表达降低及IGF-BP-3MRNA表达增高有关。     

胰岛素强化治疗对严重烫伤大鼠血清凋亡配体的作用

目的 了解大鼠严重烫伤后血清凋亡相关配体的变化及胰岛素强化治疗的作用.方法 将150只Wistar大鼠随机分为假伤组、烫伤组和治疗组.烫伤组和治疗组烫伤后立即腹腔注射等渗盐水40 mL/kg复苏;治疗组伤后24 h皮下注射胰岛素0.25 U/100 g,以后每12小时注射1次,共注射5 d.第1～5天的剂量分别为0.25、0.50、0.75、1.00、1.25 U/100 g,将大鼠血糖控制在3～6 mmol/L.假伤组浸入37℃温水假伤后不进行液体复苏.于伤后1、4、7、10、14 d抽取各组大鼠腹主动脉血,采用酶联免疫吸附测定法检测血清TNF-α、可溶性Fas配体(sFasL)、可溶性Fas受体(sFas);放射免疫法检测血清胰岛素水平.结果 烫伤组大鼠伤后1 d血清TNF-α水平[(30.9±8.7)ng/L]即达高峰,与假伤组[(12.7±2.8)ng/L]和治疗组[(16.8±4.7)ng/L]比较,差异有统计学意义(P<0.01),以后逐渐下降;治疗组大鼠伤后血清TNF-α水平虽然有所上升,但在伤后7 d内明显低于烫伤组(P<0.01).烫伤组、治疗组大鼠血清sFasL分别在伤后7～14 d和4～10 d高于假伤组(P<0.05),此后逐渐恢复至正常水平.伤后4～10 d治疗组sFas水平明显高于烫伤组及假伤组(P<0.05).伤后7、10 d烫伤组大鼠血清sFasL与sFas比值高于假伤组,而治疗组则在伤后7 d低于烫伤组(P<0.05),伤后14 d 2组均接近正常水平.烫伤组大鼠血清胰岛素水平在伤后4～10d低于假伤组(P<0.05).治疗组从伤后第1天起血清胰岛素水平即显著升高,伤后4 d[(327±15)μU/mL]达高峰,并显著高于假伤组[(42±15)μU/mL,P<0.01]和烫伤组[(28±10)μU/mL,P<0.01],随着治疗的进行,该指标逐渐恢复到正常水平.结论 胰岛素可能通过调节凋亡配体的分泌而抑制烧伤后细胞凋亡.     

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.     

A comparison of the inhibitory effects of four volatile anaesthetics on the metabolism of chlorzoxazone, a substrate for CYP2E1, in rabbits

Background: Halothane inhibits in vitro and in vivo activity of cytochrome P-450 (CYP) 2E1. There are several fluorinated volatile anaesthetics besides halothane, and most of them are defluorinated by CYP2E1. It is unclear whether other fluorinated anaesthetics inhibit the in vivo activity of CYP2E1.
Methods: We compared the inhibitory effects of therapeutic concentrations of four inhalational anaesthetics, halothane, enflurane, isoflurane, and sevoflurane, on chlorzoxazone metabolism in rabbits receiving artificial ventilation.
Results: All four inhalational anaesthetics decreased arterial blood pressure and increased plasma chlorzoxazone concentration. However, no significant differences in the plasma chlorzoxazone concentration were found between the four anaesthetics. The estimated chlorzoxazone clearance increased after beginning inhalation with all four agents, but no significant difference in clearance was noted between agents.
Conclusions: At therapeutic concentrations, the in vivo inhibitory effect on chlorzoxazone metabolism was similar for all four inhalational anaesthetics examined, even though their chemical characteristics and extent of hepatic metabolism differ considerably.     

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.