正骨散对实验性损伤局部软组织炎性细胞的影响

目的:探讨正骨散在细胞水平对急性软组织损伤的修复机制,方法:40只新西兰大耳白兔,采用重锤打击法建立急性软组织损伤动物模型,造模后随机分为:正常组(A),模型组(B),赋形剂(凡士林)组(C),正骨散组(D).造模24 h后损伤局部涂药,每日1次,用药4 d后损伤部位取材进行病理组织学观察,Elisa法测定白细胞介素-1β(IL-1β)、白细胞介素-6(IL-6)和肿瘤坏死因子α(TNFα)的含量;放免法测定血栓素(TXB2)和6-酮前列腺素F1α(6-keto-PGF1α)含量.结果:A组肌组织结构正常,横纹清晰;B组与C组肌纤维肿胀、断裂或明显坏死,间质中度或重度出血、瘀血、水肿和大量炎细胞浸润;D组肌纤维肿胀、间质出血、瘀血、水肿、炎细胞浸润则明显减轻,可见血管和成纤维细胞增生.D组IL-1β、TNFα、TXB2以及TXB2/6-keto-PCF1α比值均明显低于B组和C组;6-keto-PGF1α显著高于B组和C组;各组IL-6无明显变化.结论:正骨散可促进炎症的吸收与炎性细胞因子的稀释和转运,并能迅速地促进组织的修复与再生,其抗炎镇痛作用与IL-6关系不大.     

川芎嗪联合丹参延缓肾移植大鼠慢性移植肾肾病进程的作用

目的 研究川芎嗪(TMP)联合丹参延缓肾移植大鼠慢性移植肾肾病进程的作用及机制.方法 以Fisher 344大鼠和Lewis大鼠分别作为肾移植的供、受者进行原位肾移植,并建立CAN模型.按随机数字表法将受鼠分为5组:环孢素A(CsA)组(A组),TMP+ CsA组(B组)、丹参+ CsA组(C组)、TMP+丹参+CsA组(D组)及空白对照组(E组,术使用任何药物).分别于术后2、4、6、8和12周,处死每组5只受鼠,取移植肾进行移植肾组织病理学变化,采用免疫组织化学法检测移植肾组织转化生长因子β1(TGF-β1)的表达,采用荧光定量聚合酶链反应法检测移植肾组织TGF-β1 mRNA的表达.结果　术后空白对照组受鼠的存活时间均未超过2周.A组于术后4周时最早出现CAN病理改变,B组和C组出现CAN病理改变的时间较A组晚,D组出现CAN病理改变的时间最晚,且病理改变程度最轻.术后各组Banff评分均呈现明显的上升趋势,相同时间点,A组明显高于其他3组(P＜0.05和P＜0.0 1),D组明显低于与B组和C组(P＜0.05),而B组与C组间无显著差异(P＞0.05).随着术后时间的推移,各组TGFβ1表达强度呈逐渐增加的趋势,相同时间点,A组TGF-β1表达强度最高,与其他3组比较,差异均有统计学意义(P＜0.05和P＜0.01),D组明显低于B组和C组(P＜0.05),B组与C组间无明显差异(P＞0.05).各组TGF-β1 mRNA表达的变化趋势及组间差异与TGF-β表达强度的情况相一致.结论 TMP或丹参均具有通过下调TGF-β1 的表达延缓肾移植大鼠CAN进程的作用,当两者联合应用时作用更为明显.     

血必净联合维拉帕米对大鼠小肠缺血再灌注损伤的实验研究

目的探讨血必净联合维拉帕米对大鼠小肠缺血再灌注（I／R）损伤的保护作用及其可能机制。方法制作小肠缺血再灌注模型,SD大鼠50只随机分为假手术组（A组）、缺血再灌注组（B组）、血必净组（c组）、维拉帕米组（D组）及血必净和维拉帕米联合治疗组（E组）,各10只。分别检测各组大鼠小肠缺血45min再灌注0h、2h时血清中肿瘤坏死因子α（TNF—α）、白细胞介素1β（IL-1β）、丙二醛（MDA）的含量;同时观察小肠黏膜组织病理学变化。结果缺血再灌注组小肠组织病理学改变较其他组明显;在再灌注0h、2h时B、C、D、E组血清中TNF—α、IL-1β、MDA含量均较A组显著升高（P〈0．05）;再灌注2h时C、D、E组血清中TNF—α、IL-1β、MDA含量均较B组明显降低（P〈0．05）,但C、D两组间差异无统计学意义;C、D组血清中TNF—α、IL-1β、MDA含量均较E组明显升高（P〈0．05）。结论血必净、维拉帕米能减轻大鼠小肠缺血再灌注损伤,二者联合用药有协同保护作用,效果更明昴。     

通气侧肺吸入伊洛前列素对肺动脉压和缺氧性肺血管收缩的影响

目的 探讨雾化吸入伊洛前列素对大鼠单肺通气(one-lung ventilation,OLV)期间肺动脉压和缺氧性肺血管收缩(hypoxic pulmonary vasoconstriction,HPV)的影响。方法 雄性SD大鼠30只,随机分为A、B、C三组,每组10只。原位离体肺灌注模型建立后,调整气管导管深度致左侧肺OLV,FiO_2为100%,打开连接于呼吸回路的雾化器,A组吸入生理盐水,B组吸入伊洛前列素0.05μg·kg-1·min-1,C组吸入伊洛前列素0.1μg·kg~(-1)·min~(-1),记录灌注10min(T_1)、雾化吸入10min(T_2)和OLV 1h(T_3)的平均肺动脉压(MPAP)及左心房引流液氧分压(PaO_2)。通过测量T_1、T_2和T_3时的左心房引流液PaO_2计算氧合指数(oxygenation index,OI)。实验结束分别取双侧肺组织进行电镜检查。结果 与T_1时比较,T_2、T_3时三组MPAP明显升高(P0.05);T_2、T_3时B、C组MPAP明显低于A组(P0.05),且C组MPAP明显低于B组(P0.05)。与T_1时比较,T_2、T_3时三组OI明显降低(P0.05);T_2、T_3时C组OI明显高于B组(P0.05)。相对于B、C组通气侧,A组通气侧与A、B、C组非通气侧Ⅱ型肺泡上皮细胞核膜外突内陷,部分板层小体排空。结论 在大鼠原位肺灌注模型中,单肺通气期间雾化吸入伊洛前列素能明显降低平均肺动脉压,减少肺内分流并增加氧合。     

静脉注射肿瘤坏死因子α对大鼠骨骼肌蛋白降解的影响及机制初探

目的　观察静脉注射重组大鼠肿瘤坏死因子α(TNFα)对大鼠骨骼肌蛋白降解的影响 ,初步探讨其与糖皮质激素的关系。　方法　Wistar大鼠随机分为 3组 :A组为对照组 ;B组一次性静脉注射重组大鼠TNFα 1× 10 6 U kg ;C组预先使用糖皮质激素受体拮抗剂RU384 86灌胃 ,2h后注射重组大鼠TNFα(条件同B组 )。用药后 12h ,测量各组大鼠体温 ,分离伸趾长肌 ,称重后进行有氧孵育。采用高效液相色谱法测定总蛋白和肌纤维蛋白的降解率 ,以RNA印迹法检测泛素mRNA(2 .4kb)和C2亚基mRNA的表达变化。　结果　用药后 12h ,体温 :B、C组大鼠均明显高于A组 (P〈0 .0 1) ;伸趾长肌重量 :B、C组均明显轻于A组 ((P〈0 .0 1) ,但C组重于B组 (P〈0 .0 5 ) ;总蛋白和肌纤维蛋白降解率 :B组较A组分别升高 4 3%和 112 % (P〈0 .0 1) ;C组较B组分别降低 16 %和 2 8% (P〈0 .0 1) ;泛素mRNA和C2亚基mRNA的表达 :B组较A组分别升高约 4 .3、3.6倍 ,C组较B组均明显降低。　结论　静脉注射大剂量重组大鼠TNFα ,能增强大鼠骨骼肌泛素 -蛋白酶体途径的活性 ,导致总蛋白 ,特别是肌纤维蛋白降解率升高 ,糖皮质激素是该效应的介导因素之一     

大鼠慢性颈髓损伤后颈髓中IL-1β的表达及其与神经细胞凋亡的关系

目的:观察白细胞介素1β(interleukin-1 beta,IL-1β)在慢性颈髓损伤大鼠颈脊髓中的表达及其与神经细胞凋亡的关系。方法:4月龄SD大鼠随机分为3组:A组(模型组),破坏大鼠颈椎后柱稳定性建立慢性颈髓损伤模型,造模后立即腹腔注射生理盐水10μl,以后每周注射一次;B组(药物干预组),建立模型后立即腹腔注射IL-1受体阻滞剂(IL-1Ra,1mg/μl)10μl,以后每周注射一次;C组(对照组),切开颈椎后方皮肤后即缝合。分别饲养3、5个月后,腹腔麻醉取C4～C6脊髓。免疫组化法测定颈脊髓IL-1β的表达,TUNEL法测定颈脊髓神经细胞凋亡情况,Western Blot及定量RT-PCR分别测定caspase-3的蛋白表达及mRNA含量。结果:相同时间点颈脊髓IL-1β的表达A、B、C三组间均有显著性差异(P<0.05),A、B组同组间不同时间点比较也有显著性差异(P<0.05)。5个月时A、B、C三组神经细胞凋亡数分别为32.38±4.75个、16.56±3.89个、1.82±0.64个,三组间比较有统计学差异(P<0.01)。颈脊髓caspase-3的蛋白表达随着时间延长表达增强,使用IL-1Ra后,其表达明显减弱(P<0.05)。caspase-3 mRNA含量(拷贝数取对数)3个月时A组为8.46±0.32,B组为8.30±0.26,C组为7.95±0.36;5个月时A组为8.92±0.85,B组为8.50±0.78;C组为8.05±0.46,相同时间点各组间比较有统计学差异(P<0.01)。结论:IL-1β在大鼠慢性颈脊髓损伤的脊髓组织中有异常表达,其可能通过激活caspase-3基因参与诱导细胞凋亡。     

芒果苷对大鼠急性脊髓损伤的保护作用及相关机制研究

目的探讨芒果苷对大鼠急性脊髓损伤(spinal cord injury,SCI)的保护作用并分析其相关机制。方法成年雄性SD大鼠90只,体质量250~300 g,随机分为假手术组(A组)、SCI组(B组)、10 mg/kg芒果苷处理组(C组)、25 mg/kg芒果苷处理组(D组)、50 mg/kg芒果苷处理组(E组),每组18只。B、C、D、E组采用Allen法(60 g/cm)建立大鼠T9 SCI模型,A组仅切除T8~10椎板;C、D、E组术后每天按照10、25、50 mg/kg剂量腹腔注射芒果苷,共注射30 d;A、B组于对应时间点注射等量生理盐水。术后观察大鼠存活情况,于24、48、72 h采用BBB评分评价大鼠后肢运动功能;72 h时取损伤节段脊髓测量其水含量,ELISA检测氧化应激反应因子丙二醛(malondialdehyde,MDA)、过氧化氢酶(catalase,CAT)、过氧化物歧化酶(superoxide dismutase,SOD)、谷胱甘肽过氧化物酶(glutathione peroxidase,GSH)以及炎性因子NF-κB、TNF-α、IL-1β、IL-6活性;30 d时取损伤节段脊髓采用ELISA法检测Caspase-3、9活性,Western blot检测凋亡蛋白Bax、Bcl-2表达,组织学观察脊髓组织形态,免疫组织化学染色观察Caspase-3蛋白表达。结果术后各组大鼠均存活至实验结束。B、C、D、E组BBB评分均显著低于A组,B、C、D、E组评分呈逐渐增高趋势,组间比较差异均有统计学意义(P0.05)。B、C、D、E组脊髓水含量均显著高于A组,B、C、D、E组水含量呈逐渐降低趋势,组间比较差异有统计学意义(P0.05)。ELISA检测示,B、C、D、E组MDA、NF-κB、TNF-α、IL-1β、IL-6、Caspase-3、Caspase-9活性均显著高于A组,B、C、D、E组均呈逐渐降低趋势;而CAT、SOD、GSH活性均显著低于A组,B、C、D、E组均呈逐渐增加趋势;以上指标组间比较差异均有统计学意义(P0.05)。Western blot示,B、C、D、E组Bax蛋白表达明显高于A组,B、C、D、E组表达呈逐渐降低趋势;Bcl-2蛋白表达明显低于A组,B、C、D、E组表达呈逐渐增高趋势;组间比较差异有统计学意义(P0.05)。组织学观察示B组脊髓组织符合SCI病理改变,C、D、E组神经坏死程度较B组好转,并且E组效果优于D组,D组优于C组。免疫组织化学染色观察,B、C、D、E组Caspase-3蛋白表达量显著高于A组,B、C、D、E组呈逐渐降低趋势(P0.05)。结论对于大鼠急性SCI,芒果苷可通过减轻脊髓组织水肿、抑制氧化应激反应及炎性反应,调节Bax、Bcl-2蛋白表达,从而发挥神经保护作用。     

丙泊酚对新生大鼠海马神经元形态结构及生长相关蛋白表达的影响

目的观察丙泊酚麻醉对新生大鼠海马神经元形态结构及生长相关蛋白表达的影响。方法雄性SD大鼠175只,日龄7d,体重8~15g,随机分为对照组(A组)、丙泊酚25mg/kg组(B组)、丙泊酚50mg/kg组(C组)、丙泊酚100mg/kg组(D组)和丙泊酚200mg/kg组(E组),每组35只。A组不注射任何药物,B、C、D和E组分别腹腔注射丙泊酚25、50、100和200mg/kg。每组取5只大鼠,于苏醒后即刻抽取动脉血样进行血气分析。各组其余大鼠又随机分成等份的两个亚组:A1和A2组、B1和B2组、C1和C2组、D1和D2组、E1和E2组。A1、B1、C1、D1和E1组大鼠于苏醒后2h用透射电镜观察海马神经元的形态学变化,采用半定量逆转录-聚合酶链反应(RT-PCR)和免疫印迹法(Western blot)检测海马脑源性神经营养因子(BDNF)、Bcl-2mRNA和蛋白的表达;A2、B2、C2、D2和E2组大鼠苏醒后放回笼中继续饲养至9w时,再行上述相同实验。结果五组大鼠动脉血pH值、PaO2、PaCO2、碳酸氢根离子浓度(HCO-3)、剩余碱(BE)、SaO2差异无统计学意义。A1、A2、B1和B2组大鼠海马神经元基本正常,C1、C2、D1和D2组大鼠海马神经元细胞核肿胀、染色质减少,E1和E2组大鼠海马神经元核碎裂、染色质边集甚至出现凋亡小体。与A1组比较,B1、C1、D1和E1组大鼠海马组织BDNF mRNA、Bcl-2mRNA、BDNF蛋白和Bcl-2蛋白表达均下调(P0.05);与A2组比较,B2、C2、D2和E2组大鼠海马组织BDNF mRNA、Bcl-2mRNA、BDNF蛋白和Bcl-2蛋白表达也均下调(P0.05)。结论丙泊酚麻醉破坏海马神经元的形态结构,其机制可能与其抑制海马BDNF、Bcl-2的表达有关。     

丹参抑制转化生长因子-β1诱导的肌源性干细胞向肌成纤维母细胞分化

目的 观察丹参对失神经骨骼肌肌源性干细胞(MDSCs)向肌成纤维母细胞分化的抑制作用.方法 采用差速贴壁法分离出大鼠失神经骨骼肌MDSCs,加入转化生长因子-β1(TGF-β1)和丹参进行干预,将细胞分为3组:A:对照组;B:10 μg/L TGF-β1组;C:10 μg/L TGF-β1+ 150 mg/L丹参组.荧光实时定量聚合酶链反应(qRT-PCR)和Western blot检测各组细胞在干预后5个时间点α-平滑肌肌动蛋白(α-SMA)和波形蛋白(Vimentin) mRNA和蛋白表达.结果 与A组比较,B组和C组细胞α-SMA、Vimentin的mRNA在干预后第2、3、5、7天均明显升高(P＜0.05),其蛋白表达在干预后第3、4、6、8天亦显著升高(P＜0.05);与B组比较,C组细胞α-SMA、Vimentin的mRNA和蛋白在对应时间点均明显降低(P＜0.05).结论 丹参能抑制TGF-β1诱导的失神经骨骼肌MDSCs向肌成纤维母细胞的分化.     

胆总管梗阻解除前后脑肠肽及免疫水平变化的实验研究

目的:探讨胆总管梗阻解除前后脑肠肽水平的变化及其免疫调节作用.方法:将100只Wistar大鼠随机分为假胆总管梗阻组(A组)、胆总管梗阻组(B组)、假解除胆总管梗阻加生理盐水治疗组(C组)、解除胆总管梗阻加生理盐水治疗组(D组)、解除胆总管梗阻加善宁治疗组(E组),应用放射免疫分析法和流式细胞分析技术动态观察各组术后第1、7天血中血管活性肠肽(VIP)、P物质(SP)、白细胞介素-2(IL-2)和CD 4、CD8 水平.结果:血浆VIP、SP水平B组较A组明显升高(P＜0.05),D组较C组、E组较D组明显降低(P＜0.05).IL-2水平B组较A组降低,D组较C组、E组较D组升高(P＜0.05).术后第7天B组较A组、D组较C组CD4 降低、CD8 升高(P＜0.05).E组较D组CD4 升高、CD8 降低(P＜0.05).结论:梗阻性黄疸大鼠胆总管梗阻解除前后,血中VIP、SP等脑肠肽(BGP)呈高表达,伴有机体细胞免疫功能抑制;解除胆总管梗阻,应用善宁治疗可以通过调控脑肠肽有效地改善机体的免疫功能.     

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.     

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.     

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.