Th1/Th2平衡在高容量血液滤过防治多脏器功能衰竭中的变化及意义

目的探讨多脏器功能衰竭（MODS）发病机制及高容量血液滤过（HVHF）防治MODS的依据。方法采用2次打击法建立猪MODS模型，酶联免疫吸附试验（ELISA）法检测血清干扰素（IFN）-γ和白细胞介素（IL）-4含量变化；逆转录-聚合酶链反应（RT—PCR）法测定脾脏IFN-γ、IL-4mRNA水平及辅助T细胞特异性转录因子T-bet和GATA-3mRNA的含量变化。结果HVHF组MODS发生率为20％，显著低于MODS组88．9％（P〈0．01）；血清IFN-γ和IL-4浓度显著低于MODS组（P〈0．05），处死前IFN-γ／IL-4比值明显高于MODS组（P〈0．01）；脾脏IFN-γ和IL-4 mRNA表达量较MODS组明显下降（P〈0．05），IFN-γ/IL-4 mRNA比值明显高于MODS组（P〈0．05）；脾脏GATA3mRNA表达量低于MODS组（P〈0．01），T—bet mRNA表达量下降，差异无统计学意义（P〉0．05），T-bet／GATA3比值显著高于MODS组（P〈0．01）。结论Th1向Th2漂移可能是MODS发生的本质原因之一，HVHF能够在一定程度上遏止Th1向Th2漂移的发生。     

模拟CO2气腹对胃癌细胞黏附分子表达的影响

目的研究体外模拟不同压力CO2气腹环境对人胃癌MKN,45细胞表面黏附分子表达的影响。方法体外建立模拟CO2气腹环境,实验组分为3个亚组,气腹压力分别为1．2、1．6和2．0kPa,作用时间均为4h。实验组经气腹处理后第0、24、48、72和96h,对照组普通细胞培养4h,用流式细胞仪检测胃癌MKN-45细胞表面黏附分子CD44v6、细胞间黏附分子1（ICAM-1）和上皮型钙黏蛋白（E-cadherin）表达。结果胃癌MKN-45细胞经1．2、1．6kPaCO2气腹作用后CD44v6和ICAM-1表达呈现先升高后回落,24h时与对照组的差异有统计学意义（P〈0．01）,48h时达到高峰,然后逐渐下降,72h时与对照组比较,差异无统计学意义（P〉0．05）,96h恢复至对照组水平：E-cadherin表达变化为先降低后回升,处理后即较对照组明显下降（P〈0．01）,然后开始回升,48h时与对照组比较,差异无统计学意义（P〉0．05）,96h恢复至对照组水平。2．0kPa组CD44v6、ICAM-1和E-cadherin表达变化均更为显著．CD44v6和ICAM-1在处理后即显著高于对照组（P〈0．05）．E-cadherin表达在48h仍然明显低于对照组（P〈0．05）。结论模拟临床常用的CO2气腹压力对胃癌MKN．45细胞表面黏附分子表达可产生一过性影响．但均能在较短时间内恢复。     

改良超滤对体外循环后血浆可溶性细胞间黏附分子与肿瘤坏死因子α浓度变化的影响

目的探讨改良超滤在减轻体外循环（CPB）后炎症反应及内皮细胞损伤中的作用。方法将40例在CPB下行心脏直视手术的患者随机分为两组，超滤组（n=20）：在CPB后行改良超滤；对照组（n=20）：不进行改良超滤。两组患者分别于术前、CPB结束、术后4h和术后24h取静脉血，用酶联免疫吸附法测定血浆可溶性细胞间黏附分子-1（sICAM-1）和放射免疫法测定肿瘤坏死因子α（TNF—α）浓度，并进行比较。结果对照组患者术后4h和24h血浆sICAM-1浓度明显高于术前（P〈0．01）。术前和CPB结束时超滤组sICAM-1与对照组比较差异无统计学意义，术后4h和24h则明显低于对照组（269．6±33．8／μg／Lvs．409．6±37．3／μg／L，245．9±32．2／μg／Lvs．379．3±35．7μg／L；P〈0．01）。CPB结束时和术后4h超滤组TNF—α浓度明显高于术前（P〈0．01），但术后24h基本恢复至术前水平（0．177±0．024μg／Lvs．0．172±0．030μg／L；P〉0．05）。对照组CPB结束时TNF—α浓度明显高于术前（P〈0．01），术后4h和24h浓度有所下降，但仍较术前高（0．264±0．045μg／Lvs．0．174±0．033μg／L，0．218±0．028μg／Lvs．0．174±0．033μg／L；P〈0．05）。结论CPB可诱导炎症反应致内皮细胞损伤或激活，而改良超滤可明显减轻这些不良反应，有利于患者术后的恢复。     

黏附分子T-cadherin表达对C6细胞恶性特性的影响

目的 探讨T-cadherin分子表达对胶质母细胞瘤C6细胞的恶性生物学特征的影响。方法 C6细胞分别转染pcDNA3．T-cadherin和pcDNA3表达质粒后。筛选3个表达不同水平T．cadherin的C6克隆和2个不表达T．cadherin的C6克隆，研究T-cadherin分子表达水平对C6细胞的细胞黏附、迁移及聚集能力的影响。结果 与不表达T-cadherin的C6细胞相比．表达T-cadherin的C6细胞在附着后1h和4h时的细胞黏附能力均显著增强，分别增强61．2％和25．1％（P〈0．01），而其细胞迁移能力平均下降72．6％（P〈0．010）。同时，T-cadherin表达诱导显著的同源细胞聚集，聚集指数平均下降52．4％（P〈0．01）。结论 T-cadherin分子表达显著抑制胶质母细胞瘤C6细胞的恶性生物学特性。     

肝糖原贮备对热缺血再灌注大鼠肝细胞凋亡的影响

目的探讨肝糖原贮备对热缺血再灌注肝细胞凋亡及肝损伤的影响。方法建立大鼠肝热缺血模型。实验分组：术前24h静脉注射25％葡萄糖组，2ml／只，每6h1次，高糖饮食（H组）；术前禁食24h，饮水不限（L组）；正常饮食对照组（N组）和假手术组（S组）。缺血45min，再灌注2、24h取材。流式细胞术检测细胞凋亡及Bcl-2、Bax蛋白。同时进行肝酶学检测、肝组织形态学观察。结果1．细胞凋亡及蛋白表达：（1）24h细胞凋亡百分率。s组〈H组〈N组〈L组（P〈0．01），各组24h凋亡率均高于2h（P〈0．01，S组除外）。（2）Bcl-2、Bax蛋白表达量。①再灌注24hBcl-2表达量：H组明显高于其余3组（P〈0．01），L组〈N组（P〈0．05），与2h比较H组表达升高（P〈0．01）；②再灌注24hBax表达量：S组明显低于其余3组（P〈0．01），L组〉N组（P〈0．01）。2．肝酶学指标：各时相点4组间比较差异有统计学意义（P〈0．05），S组〈H组〈N组〈L组。3．肝脏病理组织学改变：再灌注24hH组明显轻于N组及L组，并接近S组，L组最严重。结论预防性增加肝糖原贮备可抑制热缺血再灌注过程中肝细胞凋亡，减轻肝损伤，并可能通过影响Bcl-2、Bax的表达发挥作用。     

下肢静脉高压对局部可溶性黏附分子水平表达的影响

目的研究下肢静脉高压对局部血清黏附分子含量的影响。方法经过双功彩超和静脉造影，选取单下肢慢性静脉功能不全（chronic venous insufficiency，CVI）的患者20例，在下肢静止下垂30min后分别抽取双下肢静脉血，同时取上肢静脉血作为对照组，而后取平卧位15min后再取双下肢静脉血。分为曲张静脉直立组（Vh组）、正常静脉直立组（Nh组）、曲张静脉平卧组（Vr组）、正常静脉平卧组（Nr组）和上肢对照组5组。用酶联免疫吸附法（ELISA）检测血清中的sICAM-1、sVCAM-1的含量。结果（1）Vh组和Nh组这两组静脉高压组的sICAM-1、sVCAM-1明显高于对照组（P〈0．01），而Vh组和Nh组之间差异无统计学意义（P〉0．05）。（2）Nr组和Nh组相比，sICAM-1、sVCAM-1均下降（P〈0．05）。（3）Vr组和Vh组相比，sICAM-1、sVCAM-1无明显变化（P〉0．05）。结论下肢静脉系统在血流淤滞和静脉高压的情况下，无论是否本身静脉有异常，局部的内皮细胞和白细胞均有激活并表达黏附分子。而在短时间静脉高压解除后，曲张静脉中局部的黏附分子高水平表达提示炎症仍持续，而正常静脉则有所下降。曲张静脉中炎症反应的持续性表达可能是CVI发展的重要环节。     

人近端肾小管上皮细胞黏附分子CD146表达对细胞凋亡的影响

目的：探讨人近端肾小管上皮细胞（HK-2）黏附分子CD146表达与细胞凋亡的关系。方法：体外培养的HK-2N胞在不同浓度葡萄糖和不同浓度甘露醇刺激下分别作用24h、48h、72h，经流式细胞仪（FCM）检测各组HK-2细胞CD146的表达和凋亡率的变化。结果：正常糖浓度下HK2微弱表达CD146，且延长作用时间对表达无影响；随糖浓度升高，CD146表达上调，细胞凋亡率也增高，延长刺激时间可促进CD146表达和细胞凋亡（P〈0．05）；当糖浓度达到40mmol／L，刺激时间达到48h，CD,46表达显著升高（P〈0．05），HK-2细胞凋亡率也显著上升（P〈0．05）；甘露醇对HK-2细胞CD146表达和细胞凋亡的促进作用较葡萄糖的作用显著降低（P〈0．01）。结论：HK-2组成性表达CD146，高糖诱导CD146表达，甘露醇诱导作用较高糖弱；高糖诱导HK-2凋亡，其凋亡作用与CD146表达增高联系密切，提示黏附分子CD146对细胞生存有重要影响。     

外源性一氧化碳释放分子2对严重烧伤小鼠肝脏炎性反应的抑制作用

目的 观察外源性一氧化碳释放分子2（CORM-2）对严重烧伤小鼠肝脏炎性反应的抑制作用，并探讨其机制。方法 将C57BL／6小鼠随机分成假伤组（模拟烧伤）、假伤＋CORM-2组、烧伤组、烧伤＋CORM-2组及烧伤＋二甲亚砜（DMSO）组，每组9只。假伤＋CORM-2组除伤后使用CORM-2以外，其他处理同假伤组。烧伤＋CORM-2组及烧伤＋DMSO组除伤后分别使用CORM-2、DMSO外，其余处理同烧伤组。于伤后24h检测小鼠血清丙氨酸转氨酶（ALT）及天冬氨酸转氨酶（AST）的水平，肝组织髓过氧化物酶（MPO）及核因子KB（NF-kB）活性，胞间黏附分子1（ICAM-1）和血管细胞黏附分子1（VCAM-1）蛋白的表达；检测各组小鼠肝窦内皮细胞（HSEC）经各自血清刺激后对中性粒细胞（PMN）的黏附作用。结果 与假伤组比较，烧伤组小鼠血清ALT、AST的水平[（398±34）、（122±22）U／L]及肝组织MPO活性、肝组织ICAM-1和VCAM-1蛋白表达水平均明显升高（P〈0．05或P〈0．01）。与烧伤组比较，烧伤＋CORM-2组上述情况明显改善，且NF-kB活性下降。与假伤组比较，烧伤组小鼠HSEC对PMN的黏附作用增强；烧伤＋CORM-2组该作用明显弱于烧伤组（P〈0．05）。结论 外源性CORM-2能明显抑制肝组织NF-kB活性，减少ICAM-l、VCAM-l蛋白的表达水平，减轻严重烧伤后组织中白细胞滞留，改善肝功能，可有效减轻肝脏炎性反应。     

氯胺酮和咪达唑仑对谷氨酸致大鼠神经元样PC12细胞损伤的作用

目的 探讨氯胺酮和咪达唑仑对谷氨酸致大鼠神经元样PC12细胞损伤的作用。方法 培养6-7d的神经元样PC12细胞接种于培养板培养18h后随机分为正常对照组（C组），谷氨酸组（G组），0．1、0．5、1．0mmol／L氯胺酮组（K1组-K3组），1、5、10、25、50μmol／L咪达唑仑组（M1组～M5组），0．1、0．5、1．0mmol／L氯胺酮混合10μmol／L咪达唑仑组（KM1组-KM3组）。应用MTT比色法和乳酸脱氢酶（LDH）活性检测评估细胞活力及细胞损伤程度；RT-PCR法测定c-fos mRNA表达水平；细胞免疫组化法测定Fos蛋白表达水平。结果 （1）与C组比较，除K3组外，其余各组细胞活力均降低（P〈0．05）；与G组比较，K1组。K3组、M1组-15组细胞活力均增强（P〈0．05或0．01），LDH漏出率均降低（P〈0．01）；与K1组比较，KM1组细胞活力增加，LDH漏出率降低（P〈0．05）；KM2组与K2组比较，细胞活力、LDH漏出率无明显差异（P〉0．05）。与K3组比较，KM3组细胞活力降低，LDH漏出率升高（P〈0．01）。（2）与C组比较，除K3组外，其余各组c-fos mRNA的表达均上调（P〈0．05）。与G组比较，K1组-K3组、M3组、KM2组c-fos mRNA的表达均下调（P〈0．05）；与K2组、M3组比较，KM2组c-fos mRNA的表达上调（P〈0．05）。（3）与C组比较，除K3组外，其余各组Fos染色阳性胞核数目增加，平均光密度值升高（P〈0．01）。与G组比较，K1组-K3组、M3组、KM2组Fos染色阳性胞核数减少，平均光密度值降低（P〈0．05或0．01）。与K2组、M3组比较，KM2组Fos染色阳性胞核数增加（P〈0．05），平均光密度值升高（P〈0．05）。结论 氯胺酮对谷氨酸损伤的神经元样PC12细胞具有剂量依赖性的保护作用，咪达唑仑也有神经保护作用；低剂量氯胺酮和咪达唑仑混合对神经的保护作用增强，而高剂量氯胺酮和咪达唑仑有对抗作用。     

霉酚酸酯及缬沙坦对糖尿病大鼠足细胞的保护机制研究

目的探讨霉酚酸酯、缬沙坦及2者联合应用对糖尿病。肾病（DN）大鼠足细胞损伤的保护作用。方法雄性Wistar大鼠行右肾切除后，腹腔注射链脲佐菌素（STZ，65mg／kg）建立糖尿病模型。将实验动物随机分为右。肾切除对照组（NC）、糖尿病组（DM）、霉酚酸酯治疗组（M）、缬沙坦治疗组（V）、缬沙坦和霉酚酸酯联合治疗组（V＋M）。治疗组分别给予霉酚酸酯15mg·kg^-1·d^-1，缬沙坦40mg·kg^-1·d^-1；联合治疗组为上述两组之和。检测各组8周末的左肾质量／体质量比值、尿蛋白量（24h）、血糖（Glu）、Scr。光镜及电镜观察肾组织形态学变化。免疫组化检测肾组织中nephrin、结蛋白（desmin）及单核细胞趋化因子1（MCP-1）蛋白表达。实时PCR测定肾组织中nephrin及MCP-1mRNA表达。结果与NC组相比，DM组大鼠血糖、尿蛋白量及左肾质量／体质量比值均显著上升（P〈0．01）；肾小球硬化指数（GSI）及肾间质损害加重（P〈0．01）；肾组织内MCP-1、desmin蛋白表达均显著上调（P〈0．01）。与DM组比较，M组、V组及V＋M组上述指标除Glu、Scr外，均明显改善（P〈0．05或P〈0．01）。与NC组（100％）相比，DM组nephrinmRNA表达下调（78％，P〈0.05）；各治疗组nephrinmRNA表达增加，以M组增加最明显（134％，P〈0．01）。与NC组（100％）相比，DM组MCP-1mRNA表达明显上调（251％，P〈0.05）；各治疗组明显降低，以M组最显著（126％，P〈0．01）。nephrinmRNA与MCP-1mRNA表达呈负相关（r=-0，86。P〈0．01）。尿蛋白量（24h）与MCP-1mRNA呈正相关fr=0．82，P〈0．01）；与nephrinmRNA呈负相关（r=-0．78，P〈0．01）。结论霉酚酸酯及缬沙坦均能下调糖尿病大鼠肾组织中desmin及MCP-1基因及蛋白的表达，上调nephrin基因及蛋白表达，降低尿蛋白量，预防肾损伤。联合治疗不优于单一治疗。霉酚酸酯可能通过抗炎性反应减轻足细胞损伤，减少蛋白尿，对早期DN大鼠具有明显的肾保护作用。     

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.     

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.