丙泊酚抑制H_2O_2诱导的内皮细胞通透性增加

目的探讨丙泊酚对H2O2诱导的内皮通透性增加的影响。方法实验一:分别用0、0.2、0.4、0.6和0.8mmol/L H2O2刺激人脐静脉内皮细胞(human umbilical vein endothelial cells,HUVECs)后通过测量跨细胞电阻(TER)以观察H2O2对HUVECs通透性的影响。实验二:随机分为对照组(C组,无处理)、PBS组(等体积PBS)、丙泊酚1组(P1组,丙泊酚20μmol/L)、丙泊酚2组(P2组,丙泊酚50μmol/L)、丙泊酚3组(P3组,丙泊酚100μmol/L)及脂肪乳剂组(Ⅰ组,等体积脂肪乳剂)。按实验设计预处理30min后,选用0.6mmol/L H2O2刺激HUVECs 60min(C组无处理),然后分别以TER、免疫荧光染色、western blot检测内皮细胞通透性、细胞肌动蛋白(F-actin)形态学、ERK1/ERK2及p38磷酸化水平。结果与0mmol/L H2O2比较,0.4、0.6、0.8mmol/LH2O2刺激后30~180min HUVECs TER明显减少(P0.05),刺激60min HUVECs TER明显减少并达到峰值,而后均呈恢复趋势,而且0.6、0.8 mmol/L H2O2刺激后HUVECs TER明显低于0.4mmol/L H2O2(P0.05)。与C组比较,0.6mmol/L H2O2刺激后15~60min PBS组、P1组、I组和刺激后45、60min P2组、P3组HUVECs TER明显减少(P0.05)。与PBS组比较,刺激后30~60min P2组、P3组HUVECs TER明显增加(P0.05)。与P2组比较,刺激后30~60min P1组、I组HUVECs TER明显减少(P0.05)。C组F-actin集中分布在内皮细胞周边,无应力纤维形成;PBS组F-actin在细胞内非极性排列成束,应力纤维形成;P2组H2O2诱导的F-actin细胞内束集及应力纤维形成明显得到改善;I组应力纤维形成。与C组比较,PBS组、P2组和I组内皮细胞ERK1/ERK2及p-38磷酸化水平明显升高(P0.05)。与PBS组比较,P2组内皮细胞ERK1/ERK2及p-38磷酸化水明显降低(P0.05)。结论丙泊酚可以抑制H2O2诱导HUVEC通透性增高,其分子机制可能与抑制p38及ERK1/2信号通路激活有关。     

血红素加氧酶-1预处理对大鼠肺泡Ⅱ型上皮细胞氧化损伤的影响

目的 评价血红素加氧酶-1(HO-1)预处理对大鼠肺泡Ⅱ型上皮细胞氧化损伤的影响.方法 成年健康雄性SD大鼠,体重180～220 g,原代培养肺泡Ⅱ型上皮细胞,经鉴定后随机分为6组(n=8):对照组(C组),不给予任何药物,继续培养5 h;H2 O2组,加入0-5 mmol/L H2 O2,孵育3 h;不同浓度HO-1预处理组(H1-4组),分别加入0.01、0.10、1.00、10.00μmol/L HO-1孵育2 h,然后加入0.5 mmol/L H2 O2,孵育3 h.孵育结束后,于倒置相差显微镜下观察细胞形态,并进行肺泡Ⅱ型上皮细胞计数,测定细胞活力.结果 C组、H2～4组肺泡Ⅱ型上皮细胞大部分贴壁,呈圆形,胞质均匀,胞浆内含颗粒状物质;而H2 O2组和H1组肺泡Ⅱ型上皮细胞内可见反光增强的空泡,上清液中有较多的细胞碎片.与C组比较,H2O2组和H1组细胞计数和细胞活力降低(P＜0.05),H2～4组细胞计数和细胞活力差异无统计学意义(P＞0.05);与H2O2组和H1组比较,H2～4组细胞计数和细胞活力升高(P＜0.05);H2O2组和H1组间,H2～4组间细胞计数和细胞活力差异无统计学意义(P＞0.05).结论 0.10～10.00μmol/L HO-1预处理可减轻大鼠肺泡Ⅱ型上皮细胞氧化损伤.     

低表达蛋白HAX1对Hela细胞凋亡的影响

目的 观察低表达蛋白HAX1对Hela细胞维持线粒体膜电位及细胞凋亡的影响.方法 利用RNA干扰技术抑制Hela蛋白HAX1表达3 d后,利用阳离子脂质荧光染料JC-I标记法和流式细胞仪检测并比较实验组(蛋白HAX1低表达组)及对照组细胞线粒体膜电位变化趋势.加入H2O2(2 mmol/L)诱导细胞凋亡3 h后利用Annexin V-FITC法检测并比较两组细胞凋亡率.结果 对照组细胞线粒体膜电位下降百分比均值为9.52%,实验组细胞线粒体膜电位下降百分比均值为21.12%,实验组细胞线粒体膜电位降低比率多于对照组(P＜0.05).对照组H2O2(2 mmol/L)诱导细胞凋亡率均值为21.80%,实验组H2O2(2 mmol/L)诱导细胞凋亡率均值为31.73%.实验组细胞凋亡率高于对照组(P＜0.05).结论 低表达蛋白HAX1不仅可以降低Hela细胞线粒体膜电位稳定性,而且促进Hela凋亡.     

丙泊酚抑制过氧化氢诱导人红细胞衰亡

目的 观察过氧化氢(hydrogen peroxide,H2O2)在体外诱导人红细胞磷脂酰丝氨酸(phosphatidylserine,PS)外露及前向散射值(forward scatter,FSC)的变化,探讨丙泊酚对此的影响和机制.方法 健康成年人红细胞制成2％悬液,分为5组:对照组(C组)、H2O2组(H组)、丙泊酚10 μmol/L+H2O2组(P10+H组)、丙泊酚50 μmoL/L+ H2O2组(P50+H组)、丙泊酚100μmol/L+H2O2组(P100+H组).以离子霉素、维生素E和英脱利匹特为阳性和阴性对照.各组H2O2的反应浓度均为200μmol/L,孵育1h后用流式细胞仪检测红细胞PS标记率及FSC.所得数据用SPSS软件统计处理.结果 红细胞PS标记率H组比C组(15.20±1.01)、(1.45±0.21)(P＜0.001)明显增高,P50+H组(3.09±1.66)和P100+H组(1.68±0.28)均比H组(15.20±1.01)明显低(P＜0.001).FSCH组比C组小(1 768±9)、(1 808±26)(P=0.047),P50+H组比H组明显恢复(1 811±16)、(1 768±9)(P=0.037).结论 H2O2能诱导人红细胞衰亡,丙泊酚对其有明显抑制作用,其机制在于丙泊酚有较强的抗氧化及清除自由基功能.     

丹参多酚酸盐预处理对肾小管上皮细胞凋亡的保护机制

目的：为丹参多酚酸盐治疗肾脏急性肾损伤提供理论依据.方法：将肾小管上皮NRK52E细胞随机分组.对照组不干预;H2O2组加入H2O2使终浓度为400 μmol/L,丹参多酚酸盐组分为1、2、3组分别加入丹参多酚酸盐使终浓度分别为0.4 μg/ml、4 μg/ml、40 μg/ml,H2O2＋丹参多酚酸盐1、2、3组分别加入H2O2及丹参多酚酸盐,检测SOD数值,观察细胞损伤情况,MTT法观察细胞的活性,流式细胞术检测细胞凋亡率,RT-PCR检测Survivin,基因mRNA的表达.结果：H2O2组细胞凋亡率明显高于对照组及丹参多酚酸盐组;H2O2＋丹参多酚酸盐组凋亡率明显低于H2O2组;H2O2＋丹参多酚酸盐组Survivin mRNA表达明显高于H2O2组.结论：丹参多酚酸盐能显著抗氧化,从而抑制H2O2诱导的肾小管上皮细胞凋亡,其作用机制可能与其可增加Survivin表达有关;丹参多酚酸盐可用于肾脏急性损伤的治疗.     

依达拉奉通过c-jun氨基端激酶通路和线粒体信号途径对H2O2诱导神经元凋亡的保护作用

目的 观察依达拉奉通过c-jun氨基端激酶(JNK)通路和线粒体信号途径对神经元凋亡的保护作用.方法 采用新生1dSD乳大鼠体外培养的大脑皮层神经元被随机分为空白对照组、氧化应激组(加入终质量浓度为500 μmol/L H2O2在37℃条件下进行)和依达拉奉组(提前30 min加入终质量浓度为300μmol/L的依达拉奉后加入终质量浓度为500 μmol/L H-2O2,在37℃条件下进行).免疫荧光显微镜观察神经元形态、Western blot法检测JNK、P-JNK相关蛋白表达、检测细胞色素C(Cyt-C)和线粒体形态的变化.结果 依达拉奉组中0.5h和2.0h两个样本的P-JNK/JNK比值分别为0.057和0.172,相对于氧化应激组明显降低,差异有统计学意义(P＜0.05).在Cyt-C的检测中,依达拉奉组中0.5h和2.0h两个样本的Cyt-C分布较同时间点的氧化应激组集中,且电镜中也可见依达拉奉组(0.5h、2.0h)中线粒体损伤比同时间点的氧化应激组轻.结论 H2 O2诱导的氧化应激反应可能通过JNK通路和线粒体信号途径诱发神经元细胞的凋亡,在凋亡早期使用依达拉奉可能通过JNK通路和线粒体信号途径抑制神经元凋亡.     

高温预处理对过氧化氢诱导大鼠心肌细胞线粒体金属硫蛋白表达的影响

目的 探讨高温预处理对过氧化氢(H2O2)诱导大鼠心肌细胞线粒体金属硫蛋白(MT)表达的影响.方法 采用随机数字表法,将体外培养的H9C2大鼠心肌细胞分为3组(n=6):正常对照组(C组)心肌细胞加入含血清DMEM培养基,置于37℃5％CO2培养箱中3 h;H2O2组加入含0.5mmol/L H2O2的无血清DMEM培养基,置于37℃5％CO2培养箱中孵育3h;高温预处理组(HTP组)加入含血清DMEM培养基,置于42℃恒温水浴lh,行高温预处理,然后在37℃5％CO2细胞培养箱中孵育12 h,去除DMEM培养基,随后处理同H2O2组.采用流式细胞术测定心肌细胞凋亡率;观察心肌细胞线粒体超微结构;采用Western blot法测定线粒体MT的表达.结果 与C组比较,H2O2组和HTP组细胞凋率升高,线粒体MT表达上调(P＜0.01);与H2O2组比较,HTP组细胞凋率降低,线粒体MT表达上调(P＜0.01).HTP组心肌细胞线粒体损伤较H2 O2组减轻.结论 高温预处理减轻H2O2诱导大鼠心肌细胞损伤的机制可能与上调线粒体MT表达,增强心肌内源性保护机制有关.     

二羟异黄酮和三羟异黄酮对CHO细胞抗氧化活性的比较研究

目的:研究二羟异黄酮(Daidzein)和三羟异黄酮(Genistein)对H2O2诱导的中国仓鼠卵巢细胞(CHO)氧化损伤的保护作用及探讨其抗氧化活性的作用机制。方法:H2O2体外培养CHO细胞建立细胞氧化损伤模型,预先加入三羟异黄酮和二羟异黄酮(0.25～20μmol/L)作用24h作为保护后再加入100μmol/LH2O2作用3h,显微镜下观察CHO细胞形态改变,MTT法检测活细胞数,LDH法检测细胞的损伤情况,MDA生成量和SOD活性的测定检测细胞膜脂质过氧化反应程度。结果:H2O2处理细胞3h后,细胞形态发生明显改变,胞体变小、突起缩回;MTT吸光值减小,活细胞数减少;MDA生成量和LDH释放量明显增多,SOD活性下降,与正常对照组比较有显著性差异(P<0.01)。Daidzein处理组和Genistein处理组细胞形态明显改善,MTT吸光值显著增加,MDA生成量和LDH释放量明显减少,与H2O2处理组相比有显著性差异(P<0.01)。结论:与三羟异黄酮相比,二羟异黄酮一样能显著抑制H2O2对CHO细胞的氧化损伤,且具有较强的保护作用。     

异氟醚对肺泡Ⅱ型细胞表面活性物质相关蛋白A的影响

目的 通过原代培养的正常及受H2O2损伤的肺泡Ⅱ型上皮细胞（ATⅡcell）,探讨异氟醚（Iso）对肺泡Ⅱ型上皮细胞表面性物质相关蛋白A（SP-A）的影响。方法 肺泡Ⅱ型上皮细胞培养32小时后,被分为六组;对照组（不加任何药物）、0.28mmol/L Iso组、2.8mmol/L Iso组、75μmol/L H2O2组、75μmol/L H2O2 0.28mmol/L Iso组和75μmol/L H2O2 2.8mmol/L Iso组,继续培养3小时。通过酶联免疫吸附法（ELISA）检测Ⅱ型上皮细胞内和培养液中SP-A含量。结果 Iso降低正常肺泡Ⅱ型上皮细胞内和培养液中SP-A含量;经H2O2作用后,SP-A含量亦显著减少,异氟醚增强H2O2的作用。结论 Iso可降低肺泡Ⅱ型上皮细胞合成SP-A的功能,尤其是在过氧化环境中。     

促红细胞生成素抑制过氧化氢诱导的肾小管细胞凋亡

目的探讨促红细胞生成素（erythropoietin,EPO）是否可以抑制过氧化氢（H2O2）诱导的氧化应激和细胞凋亡及其抑制凋亡的相关机制。方法传代培养大鼠近端肾小管上皮细胞（NRK-52E）,分为正常对照组（NC组）、H1组（1mmol／L H2O2）、H2组（5mmol／LH2O2、E组（H2U＋EPO组）。细胞免疫荧光检测NRK-52E细胞是否表达EPO受体（erythropoietin receptor,EPOR）。荧光探针氯甲基二氯二氢荧光素二乙酯（CM—H2DCFDA）标记检测细胞内活性氧（reactive oxygen species,ROS）水平。流式细胞仪AnnexinV-FITC／PI双染法检测细胞凋亡指数。RTPCR检测凋亡相关基因B细胞淋巴瘤／白血病-2（B-cell lymphoma／L eukemia-2,Bcl-2）家族中Bcl-2和BaxmRNA的表达。结果NRK52E细胞表达EPOR。H2O2引起NRK-52E细胞内ROS水平升高,上调BaxmRNA表达、下凋Bcl-2mRNA表达,诱导NRK-52E细胞凋亡。EPO可以抑制H2O2诱导的ROS水平升高、Bcl2mRNA表达下调、BaxmRNA表达上调及NRK-52E细胞凋亡。结论EPO可以缓解H2O2诱导的氧化应激、上调Bcl-2mRNA表达、下调BaxmRNA表达,抑制H2O2诱导的NRK52E细胞凋亡,发挥肾小管细胞保护效应。     

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 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.     

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.     

Is the recovery profile of mivacurium independent of the rate of decay of its plasma concentration in patients with normal plasma cholinesterase activity?

Background: The duration of action of muscle relaxants is poorly correlated to the rate of decay of their plasma concentration. The plasma concentration of mivacurium may rapidly decrease below its active concentration because of the extensive hydrolysis of mivacurium. By inflating a tourniquet on one upper limb for 3 min after the administration of atracurium, mivacurium or vecuronium, we studied the influence of the initial decline of their plasma concentration on their effect. Methods: In 50 patients anaesthetised with thiopental, isoflurane and fentanyl, the effect of bolus doses of 0.15 or 0.25 mg . kg^?1 mivacurium (MIV 15, MIV 25), 0.3 or 0.5 mg . kg^?1 atracurium (ATR 30, ATR 50) and 0.06 or 0.1 mg . kg^?1 vecuronium (VEC 06, VEC 10) were measured on both arms (evoked response of the adductor pollicis to train-of-four stimulation every 12 s), a tourniquet being applied on one arm just before and during 3 min after the muscle relaxant bolus. Results: Tourniquet inflation of 3 min almost abolished the neuromuscular effect of mivacurium. In the vecuronium groups and in the ATR 50 group, tourniquet inflation did not modify the maximum degree of depression of the twitch response. Also, the duration of action of vecuronium was unaffected by the tourniquet. In the ATR 30 group, times to return of the twitch response to 25% (duration 25%) and 75% (duration 75%) of control response were significantly shorter in the cuffed arm, 23 min vs 27 min, and 41 min vs 45 min, respectively. In the ATR 50 group, only duration 25% was significantly shorter in the cuffed arm (41 min vs 45 min). Conclusion: The results suggest that the rate of decline of the plasma concentration of mivacurium is so rapid, that a very low and almost clinically ineffective concentration is present as soon as 3 min after its administration. The results also indicate that the recovery from a mivacurium-induced neuromuscular blockade is not influenced by the rate of decay of its plasma concentration in patients with genotypically normal plasma cholinesterase.     

Membranes in Artificial Organs

Abstract: Membrane processes play a pivotal and enabling role in modern replacement therapy for acute and chronic organ failure and in the management of immunologic diseases. In fact, virtually all contemporary extracorporeal blood purification methods employ membrane devices, and the next generation of artificial organs and tissue engineering therapies are almost certain to be similarly grounded in membrane technology. In this short essay, we comment on the similarities and differences among synthetic membranes and their natural counterparts and also provide a critical overview of the demographics and technology of hemodialysis, hemofiltration, apheresis, oxygenation, and emerging membrane technologies and applications.     

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.     

Dilemma of Membrane Biocompatibility and Reuse

Abstract: Numerous articles have been published on the multiple use of dialyzers and on the effect of different reprocessing chemicals and techniques on the dialyzer biocompatibility and performance. The results often appear contradictory, especially those comparing standard biocompatibility parameters. Despite this confusion, a discerning review of the published works allows certain limited conclusions to be drawn. Reprocessing of used hemodialyzers changes the biocompatibility profile of a dialyzer as defined by the parameters complement activation. leukopenia, and cytokine release. The effect of reprocessing depends on the chemicals and reprocessing technique applied and also on the type of membrane polymer being subjected to the reprocessing procedure. Reports of pyrogenic reactions indicate that the flux of the membrane also influences how suitable it is for safe reuse. An increased risk of allergic and pyrogenic reactions appears to be associated with dialyzer reuse. Furthermore, there has been a lack of investigations into the immunologic effect of the layer of adsorbed and chemically altered proteins that remains on the inner surface of reprocessed dialyzers. We conclude that the clinical benefit of dialyzer reuse cannot be generally accepted from a biocompatibility point of view.