色素痣脱细胞真皮基质制备方法的实验研究

目的 通过对色素痣组织的脱细胞处理,制备一种能够避免异种和同种异体脱细胞真皮基质缺点的自体脱细胞真皮,为自体组织回植修复组织缺损提供实验依据.方法 将手术切除的1例患者的色素痣组织,切取2cm×2cm大小的色素痣25块,置于0.25% DispaseⅡ试剂中,室温下消化24h,去除表皮后,随机分成5个组,分别置于0.25%、0.5%、1.0%、2.5%、5.0%Triton X-100试剂中室温下消化.于不同的作用时间,取标本进行光镜、扫描电镜、透射电镜等检测.结果 色素痣组织在0.25%DispaseⅡ室温下作用24h,去除表皮,再分别用不同浓度的Triton X-100处理48～72h,可有效地去除色素痣组织中的痣细胞及其他所有细胞成分.光镜下胶原纤维粗细均匀,排列规整,无明显变性.扫描电镜观察可见起伏的皮肤纹理及天然毛孔结构,胶原纤维完整而连续,呈规律排列,相互交织成疏松立体网状结构.透射电镜观察胶原纤维粗细均匀,结构清晰,排列规整,可见细胞脱除后留下的腔隙,未见任何细胞碎片的残留.结论 用Triton X-100处理经DispaseⅡ消化去表皮的色素痣组织,当Triton X-100浓度超过0.5%以及Triton X-100作用时间超过48h,可有效地去除色素痣组织中的痣细胞及其他所有细胞成分,进一步增加Triton X-100浓度和脱细胞时间对脱细胞的效果无明显影响.     

脱细胞肝支架的结构和成分对细胞相容性的影响

目的 比较不同方法制备脱细胞肝支架(DLBS)的结构和成分以及细胞相容性,探讨其内部联系.方法 取50只成年F344大鼠肝脏,使用文献报道的3种方法[以十二烷基硫酸钠(SDS)、Triton X-100和NP-40为主洗脱剂]制备大鼠DLBS.进行扫描电镜和孔径计算和氨基葡聚糖(GAG)检测.后经门静脉灌注肝卵圆细胞,进行黏附率、增殖情况、免疫荧光、扫描电镜以及白蛋白分泌检测.结果 大体观察、扫描电镜及孔径计算表明NP-40方案细胞外基质较SDS和Triton X-100方案整齐；GAG检测NP-40方案[(44.19±3.35) ng/mg]高于Triton X-100方案[(36.71±2.01) ng/mg]和SDS方案[(21.63 ±2.78) ng/mg]；细胞黏附率显示NP-40方案[(95.78±2.11)％]高于SDS方案[(84.18±3.30)％]和Triton X-100方案[(91.15±2.21)％]；细胞增殖情况Triton X-100方案和NP-40方案的细胞增殖速度显著高于SDS方案(P＜0.05)；白蛋白分泌NP-40方案[(85.77±3.30) mg/106个细胞]明显好于SDS方案[(49.37±2.43) mg/106个细胞]和Triton X-100方案[(74.66 ±4.80) mg/106个细胞].结论 DLBS的结构和成分对支架的细胞相容性具有明显的影响,同时也明显观察到NP-40方案较SDS和Triton X-100方案在制备DLBS的优势.     

超声波联合曲拉通X-100制备猪去细胞的主动脉支架

目的 探讨超声波联合曲拉通X-100制备猪升主动脉去细胞支架的方法及效果.方法 从体质量相近的中华实验猪制备新鲜主动脉标本280份,随机分为4组:空白对照组、曲拉通X-100(Triton X-100)和SDS(十二烷基磺酸钠)组、曲拉通X-100组、超声波联合曲拉通X-100组,通过组织学及电镜观察、生物力学性能测定、免疫组织化学检测Ln和Fn的蛋白表达变化等分析比较各组去细胞的效果.结果 超声波联合曲拉通X-100组可完全去除动脉内膜细胞,组织形态、生物力学等保持良好.层粘连蛋白(Ln)和纤维连接蛋白(Fn)的阳性面积×平均吸光度值分别是0.01470±0.001 60、0.01340±0.000 29,明显优于传统的化学去细胞方法.结论 超声波联合曲拉通X-100组去细胞效果优于传统化学去污剂,是较理想的制备猪动脉去细胞支架的方法.     

三种屈肌腱缝合方法的生物力学研究

目的比较三种不同屈肌腱缝合方法的生物力学性能及操作时间,寻找一种不仅具有良好生物力学性能而且有利于临床推广的屈肌腱缝合方式。方法选取猪后足屈趾深肌腱作为实验对象,共24个,随机分为3组。横行切断肌腱后,分别采用改良kessler缝合、内锁缝合、半结锁定式缝合三种不同缝合方式并结合连续周边缝合将肌腱断端进行缝合,记录操作时间,并对修复肌腱进行生物力学测试,测定修复肌腱的2mm裂隙抗张强度、断裂抗张强度和断裂间隙。结果与改良kessler缝合相比,内锁缝合与半结锁定式缝合均能显著提高修复肌腱的2mm裂隙抗张强度和断裂抗张强度。内锁缝合的2mm裂隙抗张强度(58.8±8.1)N与半结锁定式缝合(53.7±6.0)N没有明显差异,而断裂抗张强度(72.7±6.0)N明显大于半结锁定式缝合(60.4±6.6)N。内锁缝合与改良kessler缝合的断裂间隙无明显差异,两者均小于半结锁定式缝合(8.5±1.3)mm。与改良kessler缝合(11.1±1.4)min相比,内锁缝合(15.4±1.1)min与半结锁定式缝合(15.8±0.9)min的操作时间均较长,而两者之间无明显差异。结论与改良kessler缝合和半结锁定式缝合相比,内锁缝合具有更好的生物力学性能并有效阻止间隙形成,更值得临床应用推广。     

曲拉通X-100对制备猪胸主动脉脱细胞血管基质影响的实验研究

目的为将内皮细胞和平滑肌细胞种植于脱细胞血管基质(Acellular Tissue Matrix,ACTM)上形成组织工程化血管提供实验依据.方法用曲拉通(Triton)X-100等试剂制备猪胸主动脉ACTM,并寻找曲拉通X-100的最佳浓度.取家猪的新鲜去除外膜胸主动脉56根,随机分成7组,每组分别浸入不同浓度的曲拉通 X-100中作用144 h～240 h.标本作HE弹力纤维染色,大体、光镜及透射电镜观察.结果经上述试剂处理后,光镜及透射电镜检查显示,制备出的猪胸主动脉脱细胞血管基质由胶原纤维、弹力纤维和某些不可溶的、变性细胞器构成.曲拉通 X-100最佳浓度为1%.时间为176.25 h±5.5 h.结论本方法可成功制备猪胸主动脉ACTM,1%曲拉通 X-100是制备血管ACTM的良好试剂.     

γ射线照射对人肌腱组织形态学及羟脯氨酸含量的影响

[目的]研究2.87 Mrad剂量γ射线照射后,肌腱组织形态学及羟脯氨酸含量的变化.[方法]选取40根人新鲜上肢掌深屈肌腱,-80℃深低温冷冻6周,等分为二:实验组(A组),对照组(B组).A组肌腱在干冰低温保存条件下行γ射线照射,检测肌腱最终吸收剂量为2.87 Mrad.分别行HE、VG染色,在普通光镜和透射电镜下观察其组织形态学变化.用柱前衍生高效液相色谱分析法检测肌腱胶原蛋白水解液中羟脯氨酸含量.[结果]①形态学观察发现,同非照射组肌腱相比,照射组肌腱胶原纤维束间隙较大,纤维排列卷曲紊乱,并可见部分纤维发生断裂.电镜下胶原纤维横纹模糊消失,腱细胞膜溶解消失,核崩解,细胞器减少.②在同等水解条件下,胶原蛋白水解液中照射组羟脯氨酸含量与非照射组相比,有显著差异(P＜0.05).[结论]2.87 Mrad剂量γ射线照射可引起肌腱组织形态结构发生显著改变.在同等水解条件处理下,照射组肌腱胶原蛋白水解液中羟脯氨酸含量显著高于非照射组.     

两种肌腱缝合方法的对比研究

目的 对两种肌腱缝合方法的生物力学特性进行对比研究,为临床肌腱修复术对缝合方法的选择提供理论依据.方法 收集30根完整的废弃肌腱,随机分为两组,从中间锐性切断.A组:采用新创ZM缝合法缝合肌腱;B组:采用改良Kessler缝合法缝合肌腱,缝合后立即进行生物力学测试.测定2mm间隙形成负荷、最大负荷、最大间隙、断裂方式,计算所修复肌腱的强度,所得数据进行统计学分析.结果 A组的2mm间隙形成负荷为(46.13±1.57)N、最大负荷为(57.18±1.84)N、强度为(8.45±0.34) N/mm,均大于B组的2 mm间隙形成负荷(15.02±0.67)N、最大负荷(28.63±1.95)N、强度(2.47±0.22) N/mm;A组的最大间隙(6.77± 0.29)mm小于B组的最大间隙(11.62± 0.94) mm;A组的缝线抽出率(0)小于B组缝线抽出率(100％).结论 ZM缝合法具有良好的抓持作用和强大的抗张力强度,可以满足屈肌腱修复术后早期无抗阻主动功能锻炼的需要.     

原花青素处理去细胞牛颈静脉带瓣管道的生物学特性

目的 观察原花青素处理去细胞牛颈静脉带瓣管道的生物学特性.方法 分别比较去细胞处理、原花青素去细胞联合处理、戊二醛处理和新鲜未处理带瓣牛颈静脉管道管壁、瓣膜的厚度、大体形态、组织学特点、含水量、热皱缩温度及断裂强度,并进行可溶性蛋白含量的测定.结果 原花青素去细胞联合处理组牛颈静脉带瓣管道较未处理组的管壁、瓣膜厚度[管壁:(0.81±0.17) mm比(0.79 ±0.14) mm,瓣膜:(0.23±0.07) mm比(0.21 ±0.05) mm,P＞0.05]、组织含水量[管壁:(85.30 ±2.13)％比(88.10±2.93)％,瓣膜:(87.30±2.67)％比(91.40±3.41)％,P＞0.05]无明显变化;管壁、瓣膜断裂强度[管壁:(10.32±1.07)N比(6.83±1.03)N,瓣膜:(7.49±0.81)N比(3.21 ±0.57)N,P＜0.05]和热皱缩温度[管壁:(85.30±1.21)℃比(70.40 ±0.32)℃,瓣膜:(87.30±2.67)℃比(70.70±0.61)℃,P＜0.05]明显提高,与戊二醛处理组比较差异无统计学意义(P＞0.05)原花青素去细胞联合处理组可溶性蛋白的含量较未处理组明显减少[管壁:(0.041 ±0.011)％比(0.178 ±0.037)％;瓣膜:(0.096±0.017)％比(0.311 ±0.063)％;P ＜0.05].结论 原花青素去细胞联合处理牛颈静脉带瓣管道材料具有较好的生物学特性.     

血小板源性生长因子BB对大鼠肌腱愈合和肌腱粘连的影响

目的 了解血小板源性生长因子BB(PDGF-BB)基因转染大鼠肌腱细胞对肌腱愈合及肌腱粘连的影响. 方法 将90只SD大鼠制成跟腱损伤模型,按随机数字表法分为3组,每组30只:实验组,肌腱断端注射20μL转染PDGF-BB基因的大鼠肌腱细胞(1×108个/mL);对照组,肌腱断端注射20μL未行转染的大鼠肌腱细胞(1×108个/mL);空白对照组,不做任何处理.6-0丝线行改良Kessler法缝合跟腱,管型石膏固定1周.通过基因测序及RT-PCR鉴定转染PDGF-BB基因的大鼠肌腱细胞.分别于术后3 d和1、2、4、8周取各组大鼠肌腱组织样本,行大体、组织学观察以及生物力学检测,对比各组肌腱粘连度、组织中Fb数量与胶原纤维含量、肌腱最大抗拉力及最大滑动距离、组织中PDGF-BB的浓度.对数据行t检验. 结果(1)转染的肌腱细胞经RT-PCR以及基因测序证实在体外稳定表达PDGF-BB mRNA.(2)各组大鼠术后3 d肌腱均出现较明显肿胀及炎性细胞浸润,实验组改变较其他组明显轻微;随后各组情况均逐渐好转.术后4、8周肌腱粘连度分级组间比较未见明显差异.(3)实验组Fb数在术后2、4、8周显著低于对照组和空白对照组(t值分别为2.94、4.26、5.76和4.00、3.83、6.12,P＜0.05或P＜0.01).(4)实验组术后4周胶原纤维含量为(43±6)%,较对照组[(55±8)%]与空白对照组[(61±8)%]显著下降(t值分别为2.94和4.41,P＜0.05或P＜0.01).(5)术后4、8周实验组肌腱最大滑动距离为(3.25±0.33)、(3.65±0.21)mm,显著高于对照组的(2.29±0.40)、(2.21±0.37)mm和空白对照组的(2.01±0.23)、(1.89±0.24)mm(t值分别为4.53、8.29和7.55、13.52,P值均小于0.01),但其肌腱最大抗拉力与另2组比较差异无统计学意义(t值分别为0.41、0.41和0.77、0.72,P值均大于0.05).(6)术后3 d和2、4周,实验组肌腱组织中PDGF-BB浓度为(12.95±1.36)、(8.32±0.94)、(9.10±1.06)ng/mL,均显著高于对照组的(1.13±0.21)、(2.07±0.48)、(3.85±0.39)ng/mL(t值分别为21.04、14.50、11.39,P值均小于0.01). 结论 转染PDGF-BB基因肌腱细胞有促进肌腱内源性愈合、减轻肌腱粘连的作用.     

软骨脱细胞基质的研制及其力学性质分析

目的猪CACM的制作及其力学特征的检测.方法切取猪耳软骨,采取Triton X-100、 Tris-HCl液等4步法制取脱细胞的猪耳CACM.采用光镜、透射电镜、扫描电镜等对结构进行检测,同时对CACM进行力学检测.结果肉眼观察,CACM与软骨除颜色略白外无差别.组织学HE染色,细胞陷窝已无细胞结构,阿尔新兰染色呈淡染,阴性;透射电镜下CACM软骨陷窝内已无细胞结构,细胞膜、核器均已溶解;扫描电镜下CACM基质纤维成分与正常软骨基质的胶原纤维在形态上无差异;力学试验,最大拉伸强度,最大拉伸比,猪耳软骨与其脱细胞基质比较及其弹性模量无统计学意义.结论经Triton X-100为主的脱细胞处理方法可以脱去软骨的细胞成分,不改变软骨细胞基质的主要成分,不改变其原有力学性质.     

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.