输血诱导免疫耐受对大鼠小肠移植急性排斥反应的影响

目的 观察供体特异性输血(DST)诱导免疫耐受对大鼠小肠移植后急性排斥反应的影响.方法 采用SD至Wistar大鼠异位小肠移植模型,实验组分别予以DST,环孢素(CsA)及DST联合CsA干预,Wistar大鼠同系间移植作为对照,于3、5、7 d观察移植肠管病理变化及受体血清中肿瘤坏死因子(TNF)-α和干扰素(IFN)-γ表达程度.结果 病理显示CsA干预组在7 d出现轻度移植排斥反应;DST联合CsA干预组与对照组结果相似,在3、5、7 d均无明显的移植排斥反应发生.并且DST联合CsA干预组TNF-α表达程度低于单独CsA干预组,在第7天时与对照组比较差异无统计学意义(P＞0.05);IFN-γ表达程度低于单独CsA干预组,在第5、7天时与对照组比较差异无统计学意义(P＞0.05).结论 异基因大鼠间小肠移植在CsA配合应用的情况下,进行DST可诱导其产生一定的免疫耐受,预防及减轻大鼠小肠移植急性排斥反应的发生及反应程度.     

断流分流联合手术前后血浆IL-6,IL-8和TNF-α水平的变化及其意义

目的　探讨门静脉高压症行贲门周围血管离断并脾 -肾静脉分流联合手术前后血浆白细胞介素 -6(IL 6) ,白细胞介素 -8(IL 8)和肿瘤坏死因子 -α(TNF α)水平变化的意义。方法　检测联合手术组患者术前 1d和术后 7d血浆IL 6,IL 8和TNF α含量 ,并与对照组比较。结果　联合手术组术前IL 6,IL 8和TNF α水平分别为 ( 2 3 0 .4± 10 .3 )ng/L ,( 2 0 1.5± 7.8)ng/L及 ( 2 61.5± 2 8.3 )ng/L ,明显高于对照组 (P <0 .0 1) ;联合手术后 7d ,IL 6,IL 8和TNF α水平分别为 ( 13 5 .8± 11.4)ng/L ,( 10 8.2± 8.7)ng/L及 ( 2 11.8± 3 6.5 )ng/L ,与术前比均有明显降低 ,但仍高于对照组 ( P <0 .0 1)。结论　IL 6,IL 8和TNF α的活性在肝硬化门静脉高压症的形成过程中起着重要作用 ;联合手术降低门静脉压力 ,血浆IL 6,IL 8和TNF α水平显著下降 ,表明有利于肝功能的恢复     

联合输注供体特异性不成熟树突状细胞及环胞素A对受体Th1/Th2淋巴细胞分化的影响

目的探讨联合应用体外培养供体特异性不成熟树突状细胞及环胞素A(CsA)对受体体内Th1 /Th2淋巴细胞分化的影响。方法建立大鼠同种异体原位肝移植模型 ,88只LWE大鼠和SD大鼠随机分为 3组 :(1 )对照组 :术后不予免疫抑制剂 ;(2 )CsA组 :术后第 2天起隔日腹腔内按1mg/ 1 0 0 g 体重注射CsA ,共 3次 ;(3)CsA DC组 :除术后按CsA组腹腔注射CsA外 ,第 8天阴茎背静脉注射 1 0 6个供体骨髓体外培养的不成熟树突状细胞 (DCim)。术后观察各组的生存时限及 5、1 0、1 5、2 5d分别取标本行肝脏免疫病理学检查、腹腔淋巴结中INF γmRNA、IL 6mRNA含量的检测。结果CsA DC组的生存时限为 (2 7 0± 1 0 )d ,较对照组及CsA组显著延长 (P <0 0 5 ) ;CsA DC组受体腹腔淋巴结中的INF γmRNA含量较对照组及CsA组低 (P <0 0 5 ) ,而IL 6mRNA含量则较前两组升高 (P <0 0 5 )。结论联合应用环孢素A和体外培养的供体特异性DCim后受体体内Th2型淋巴细胞含量升高 ,而Th1型淋巴细胞含量降低 ;通过调节受体体内Th1 /Th2淋巴细胞比例是其降低大鼠肝移植术后免疫排斥反应的机制之一     

异种反应性天然抗体在豚鼠至大鼠肝移植中的作用

目的　研究异种反应性天然抗体 (XNA)在豚鼠至大鼠异种肝移植超急性排斥反应(HAR)中的作用。方法　将实验鼠随机分成A、B、C、D组 ,每组 2 0只 ,分别为对照组、术前输注豚鼠肝细胞 (HC)组、术前连续肌注山地明 (CsA)组和术前输注HC合用CsA组。采用流式细胞仪和免疫组织化学方法检测受体体内XNA含量 ,观察了受体存活时间和移植肝组织学改变。结果　移植肝组织发生了HAR。受体体内存在XNA ,以IgM为主。术前输注HC使受体体内的抗体明显升高 ,A组IgM(单位 :平均荧光强度 ,下同 )为 74.58± 31 .75 ,B组为 40 6 .42± 1 0 8.0 2 (P <0 .0 1 ) ,而使用CsA能预防抗体爆发反应 ,C组为 48.82± 1 1 .0 4 (同B组比较 ,P <0 .0 1 )。术前输注豚鼠肝细胞合并使用CsA能延长受体存活时间 ,A组为 (1 2 4 .1 0± 33 .42 )min,D组为 (1 83 .70± 2 6 .85)min(P <0 .0 1 )。移植肝表现为肝细胞水样变性 ,肝血窦和血管扩张瘀血 ,但小叶结构完整。结论在豚鼠至大鼠异种肝移植中发生的HAR是一种强烈的免疫反应 ,其中XNA所起作用有限 ;术前输注豚鼠肝细胞合并使用CsA能延长受体存活时间     

重症急性胰腺炎肿瘤坏死因子-α与低钙血症的关系

目的　探讨重症急性胰腺炎(SAP)大鼠模型肿瘤坏死因子(TNF) α与血清钙水平的关系。方法　胰管内逆行注射5 %牛磺胆酸钠的方法建立SAP大鼠模型。将SD大鼠分为假手术组2 1只,SAP组2 1只,治疗组2 1只。治疗组为模型制作前15min自阴茎背静脉注入抗肿瘤坏死因子α单克隆抗体(TNF αMcAb ,5mg/kg体重) ,观察血中TNF α与血钙的水平。酶联免疫吸附法(ELISA)测定细胞因子水平。结果　重症急性胰腺炎TNF α水平与血钙之间呈显著负相关(r =-0 .69,P <0 .0 1) ,在发病初期两者关系更紧密(6h组:r =-0 .73 ,P <0 .0 1)。TNF αMcAb能改善胰腺病理变化、降低淀粉酶、降低血清TNF α、升高血钙,6hSAP组血清钙(1.99±0 .0 3 )mmol/L ,TNF αMcAb治疗组血清钙(2 .0 6±0 .0 6)mmol/L ,P <0 .0 5 ;12hSAP组血清钙(1.88±0 .0 5 )mmol/L ,TNF αMcAb治疗组血清钙(1.94±0 .0 5 )mmol/L(P <0 .0 5 )。结论　TNF α可能在SAP并发低钙血症的机制中发挥作用,尤其在疾病发生的早期     

体外光化学疗法对皮肤移植小鼠产生调节性T细胞的影响

目的探讨输注体外光化学法处理的脾淋巴细胞对皮肤移植受体小鼠产生调节性T细胞(Treg)及移植物存活时间的影响。方法以C57BL/6小鼠为供体,BALB/c小鼠为受体,建立小鼠皮肤移植模型。分离C57BL/6和BALB/c小鼠脾淋巴细胞(CSP、BSP),制备经8-甲氧基补骨脂素联合长波紫外线(PUVA)处理的小鼠脾淋巴细胞(PUVA-SP)。根据受者静脉输注的成分将实验动物随机分为5组(每组12只):PUVA-BSP组、PUVA-CSP组、BSP组、CSP组及磷酸盐缓冲液(PBS)对照组,每组受体分别于术前7 d、手术当日和术后7 d按组别从尾静脉注入PUVA-BSP、PUVA-CSP、BSP、CSP或PBS。观察受体移植物的存活时间,检测受体外周血中CD4~+CD25~+Foxp3~+Treg表达情况。结果皮肤移植术后,PUVA-BSP组和PUVA-CSP组的受体小鼠外周细胞CD4~+CD25~+Foxp3~+Treg的比例明显高于输注BSP组、CSP组和PBS对照组;PUVA-CSP组高于PUVA-BSP,BSP组和CSP组低于PBS对照组。PUVA-BSP组和PUVA-CSP组的受者小鼠移植皮片存活时间明显长于BSP组、CSP组和PBS对照组(均为P0.05)。结论输注足够数量的PUVA-SP可诱导受体体内产生较多的CD4~+CD25~+Foxp3~+Treg,可以显著延长移植物的存活时间。     

术前输注供者脾细胞联合应用西罗莫司延长小鼠移植心存活时间的机理

目的探讨移植术前输注供者脾细胞(DST)联合应用西罗莫司(SRL)延长小鼠移植心存活时间的机理。方法单向混合淋巴细胞培养中的刺激细胞及静脉输注的脾细胞均采用经丝裂霉素C处理后失去增殖活性的Balb/c(H-2~d)小鼠脾细胞(包括体外实验和体内实验)。(1)体外实验:分为3组,空白对照组:取正常C57BL/6(H-2~b)小鼠(B6小鼠)的脾细胞作为反应细胞;SRL组:取用SRL(1.5μl·g~(-1)·d~(-1))灌胃7 d后的B6小鼠脾细胞作为反应细胞;DST SRL组:取行脾细胞静脉输注8 d、次日予SRL(1.5μl·g~(-1)·d~(-1))灌胃7 d后的B6小鼠的脾细胞作为反应细胞。观察各组在单向混合培养中的脾细胞增殖能力。(2)体内实验:Balb/c小鼠为供者,B6小鼠为受者,建立颈部异位心脏移植模型。实验分为3组,空白对照组:单纯行心脏移植;DST组:受者移植前8 d给予供者脾细胞静脉输注;DST SRL组:受者移植前8 d给予供者脾细胞静脉输注,次日予以SRL灌胃7d(1.5μl·g~(-1)·d~(-1))。术后观察各组移植心的存活时间、病理表现、受者淋巴细胞中CD4~ CD25~ 调节性T细胞(Tr细胞)和凋亡细胞比例的改变及同种抗原刺激后增殖活性变化。结果体外实验中,DST SRL组反应细胞增殖活性平均为(13.76±2.81)%,明显低于空白对照组(28.14%±5.53%,P<0.05)。体内实验中,空白对照组、DST SRL组以及DST组移植心平均存活时间分别为(8.6±0.48)d、(35±14.4)d和(4.83±0.52)d,DST SRL组存活时间显著延长(P<0.05);流式细胞术(FACS)分析显示DST SRL组脾细胞中CD4~ CD25~ Tr细胞比例平均为(3.39±0.21)%,明显高于空白对照组(1.57%±0.3%,P<0.05)。结论移植术前输注供者脾细胞联合应用西罗莫司可通过清除同种反应性T细胞克隆,增加受者体内CD4~ CD25~ Tr细胞的比例,减低对同种抗原的应答能力,从而延长同种小鼠移植心存活时间。     

体外光分离置换疗法对皮肤移植小鼠IL-12p70和Th1/Th2类细胞因子产生的影响

目的探讨输注体外光分离置换疗法处理的脾淋巴细胞对皮肤移植小鼠白细胞介素(IL)-12p70和辅助性T细胞(Th)1/Th2类细胞因子产生的影响。方法以C57BL/6小鼠为供体,BALB/c小鼠为受体,建立小鼠皮肤移植模型。分离C57BL/6和BALB/c小鼠脾淋巴细胞(CSP、BSP),制备经8-甲氧基补骨脂素联合长波紫外线(PUVA)处理的小鼠脾淋巴细胞(PUVA-SP)。根据受体静脉输注的成分将实验动物随机分为5组(每组12只):PUVA-BSP组、PUVA-CSP组、BSP组、CSP组及磷酸盐缓冲液(PBS)对照组,每组受体分别于术前7 d、手术当日和术后7 d按组别从尾静脉注入PUVA-BSP、PUVA-CSP、BSP、CSP或PBS。观察经PUVA处理脾淋巴细胞凋亡情况,检测受体小鼠外周血中IL-12p70和Th1/Th2类细胞因子产生的情况。结果移植术后,PUVA-BSP组和PUVA-CSP组小鼠外周血的IL-12p70表达水平明显低于BSP组、CSP组和PBS对照组(均为P0.01);PUVA-BSP组和PUVA-CSP组的Th1类细胞因子IL-2、干扰素(IFN)-γ表达水平均明显低于BSP组、CSP组和PBS对照组(均为P0.01);PUVA-BSP组和PUVA-CSP组的Th2类细胞因子IL-10表达水平明显高于BSP组、CSP组和PBS对照组(均为P0.01)。结论输注足够数量的PUVA-SP可诱导受体体内低表达IL-12p70,并且诱导产生Th2免疫偏移。     

缺血预处理对大鼠肝脏缺血再灌注损伤保护作用机制的研究

目的　探讨缺血预处理 (IPC)保护作用的发生机制。方法　建立大鼠部分肝脏热缺血再灌注模型。IPC采用肝脏缺血 10min ,再灌注 10min。结果　IPC后肝组织中腺苷和NO水平明显升高 ,与对照组相比差异显著 (P <0 0 1) ,但IPC前应用腺苷A2 受体拮抗剂后NO的升高被抑制 (P<0 0 1)。缺血再灌注 (I/R) 2h后血清中TNF α、AST、ALT、LDH及W/D水平和假手术组相比明显增加 ,而IL 10含量降低 (P <0 0 1) ;IPC、I/R前加入腺苷、IPC前应用腺苷A1受体拮抗剂显著地降低TNF α释放和AST、ALT、LDH及W /D水平 ,提高IL 10含量 ,与I/R组相比差异显著 (P <0 0 1) ;但IPC前应用腺苷A2 受体拮抗剂 (IPC +A2 antag)和NO合成酶抑制剂NAME并没有能像IPC组那样有效降低TNF α、AST、ALT、LDH及W /D的水平 ,提高IL 10的含量 (P <0 0 1) ;而IPC前给IPC+A2 antag组提供NO前体精氨酸又获得和IPC组同样的结果 (P >0 0 5 )。结论　IPC引起细胞外腺苷水平升高 ,腺苷A2 受体活化 ,介导了NO合成增加 ,最终通过抑制效应器TNF α的释放、增加IL 10的合成来实现对缺血组织的保护作用。     

核因子-κB对大鼠移植肝血管内皮细胞活化的影响

目的　探讨大鼠肝移植后肿瘤坏死因子 α(TNF α)早期释放、核因子 κB(NFκB)活化对内皮细胞E selectin、ICAM 1表达和中性粒细胞粘附积聚的影响。方法　建立大鼠肝移植和假手术模型 ,实验组供、受鼠分别于术前 1h注射己酮可可碱 (PTX ,5 0mg/kg) ,对照组注射等量生理盐水 ,测定肝组织和血清TNF α浓度、NFκBp6 5蛋白含量、ICAM 1和E selectinmRNA表达、髓过氧化物酶(MPO)活性、血清丙氨酸转氨酶 (ALT)、门冬氨酸转氨酶 (AST)、乳酸脱氢酶 (LDH)含量及肝脏水肿程度 (W /D)。结果　移植后 1hTNF α达较高水平 ,3h达高峰 ;NFκBp6 5 3h达高峰 ,持续至 6h ;E se lectinmRNA、ICAM 1mRNA分别于移植后 6h和 12h达高峰 ;移植后 12hMPO活性明显增高。应用PTX组 ,TNF α浓度、NFκBp6 5含量、E selectin和ICAM 1mRNA表达量、MPO活性均降低 (P <0 .0 5 )。移植后 6h ,应用PTX组AST、ALT、LDH、W /D水平也显著降低 ,和对照组比较 ,差异有显著性 (P <0 .0 5 )。结论　PTX通过减少TNF α早期释放 ,抑制NFκB活化 ,从而下调内皮细胞粘附分子表达和减少中性粒细胞浸润 ,来减轻肝脏缺血再灌注损伤。     

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.