肝移植患者外周血辅助性T 17细胞的变化及意义

目的探讨肝移植术后患者外周血辅助性T(Th)17细胞(CD4+IL-17+T淋巴细胞)与急性排斥反应的关系。方法本文研究对象为2008年6月至2012年12月在首都医科大学附属北京朝阳医院肝胆胰脾外科因良性终末期肝病行原位肝移植术的76例患者。根据患者术后有否发生急性排斥反应,分为排斥组(17例)和非排斥组(59例)。所有患者均按常规定期随访。记录患者排斥反应发生情况及治疗经过。排斥组患者发生急性排斥反应时给予肝穿刺活组织检查确定排斥反应严重程度。所有患者分别于肝移植术前、出院后1年内定期(间隔3~6个月)、或急性排斥反应治疗前和缓解后(3~6个月),检测外周血CD4+IL-17+T淋巴细胞占CD4+T淋巴细胞百分比(CD4+IL-17+T%)。比较两组患者各时间点的CD4+IL-17+T%。分析CD4+IL-17+T%与排斥活动指数(RAI)、免疫抑制剂血药浓度的相关性。结果急性排斥反应发生在术后0.7~12.0个月,中位数2.5个月。肝移植术后,与非排斥组比较,排斥组患者CD4+IL-17+T%明显升高[(1.79±0.44)%比(2.56±0.43)%,P0.001]。排斥组患者发生急性排斥反应时,CD4+IL-17+T%均较未发生急性排斥反应时明显升高[(2.56±0.43)%比(1.50±0.25)%,P0.001)]。非排斥组患者不同时间点的CD4+IL-17+T%变化不明显(P0.05)。排斥组患者发生急性排斥反应时的CD4+IL-17+T%与RAI呈正相关(r=0.72,P=0.001)。排斥组和非排斥组患者他克莫司、环孢素血药浓度与CD4+IL-17+T%无明显相关性(r=0.21,-0.13;均为P0.05)。结论外周血CD4+IL-17+T%可作为诊断和评估肝移植术后急性排斥反应严重程度的监测指标,外周血CD4+IL-17+T%升高提示急性排斥反应严重。     

大鼠原位肝移植术后急性排斥反应中 Fractalkine的表达及意义

目的利用直视下套入式吻合肝动脉加袖套法吻合门静脉建立的大鼠全血供肝移植模型,研究同种异体大鼠肝移植术后早期急性排斥反应中Fractalkine（Fkn）的表达情况。方法制备SD-Wistar大鼠全血供肝移植模型,随机分为两组,每组20只。对照组：于移植术后第1天开始腹腔内注射生理盐水（3ml/kg）;实验组：于移植术后第1天开始腹腔内注射环孢素A（3mg/kg）。术后观察大鼠一般情况,并于第3、5及7天分别处死5只大鼠,取肝脏标本,观察移植肝组织排斥反应强度（rejection activity index,RAI）及Fkn表达情况;余大鼠观察生存时间。结果对照组存活18只,实验组存活19只。实验组较对照组术后一般情况好,存活时间为19.50±4.51d,与对照组7.60±1.60d比较,差异有统计学意义（P〈0.05）。组织学观察：对照组移植肝小叶结构清楚,汇管区增大,大量淋巴细胞浸润;实验组移植肝组织RAI明显降低。术后第3、5及7天,对照组RAI为3.80±0.35、5.90±0.87及7.50±1.30,实验组为3.10±0.21、3.90±0.41及4.50±0.52。两组术后第7天RAI比较差异有统计学意义（P〈0.01）。免疫组织化学观察：两组移植肝组织中均见细胞浆或细胞膜有棕色颗粒的Fkn表达,但实验组表达较弱。术后第3、5及7天,对照组Fkn细胞数为8.20±0.57、21.30±3.30及25.70±4.91,实验组分别为8.30±0.56、10.30±0.67及11.70±1.23;两组第5、7天比较差异有统计学意义（P〈0.01）。结论Fkn参与了同种异体大鼠肝移植急性排斥反应,可作为诊断大鼠肝移植急性排斥反应发生的指标之一。环孢素A可以通过抑制Fkn表达来抑制排斥反应发生的强度。     

通过小鼠皮肤移植后心脏移植模型观察记忆性T淋巴细胞的变化和作用

目的 建立小鼠皮肤移植后心脏移植模型,观察记忆性T淋巴细胞的变化和作用,及其与皮肤移植后同种反应性记忆性T淋巴细胞过继转移模型的差异和机理.方法 应用显微外科技术及血管套管法,建立小鼠皮肤移植后心脏移植模型(实验组),并以心脏移植前输注或未输注记忆性T淋巴细胞的2个组作为对照(移植对照组和输注对照组),两对照组均未进行皮肤移植.心脏移植后每天触摸各组供心的搏动情况,观察各组移植心的存活情况及组织病理学改变,并对排斥反应进行分级;采用流式细胞仪检测各组受鼠体内CD3+ CD44high CD62L-记忆性T淋巴细胞表型的分布,应用体外混合淋巴细胞反应体系综合评价各组记忆性T淋巴细胞体外增殖程度.结果 皮肤移植前受鼠体内CD4+记忆性T淋巴细胞的比例为2.7％,移植后升至72.0％ (P＜0.05).移植对照组、输注对照组及实验组移植心脏的平均存活时间分别为7.33、4.83和3.5d,排斥反应评分分别为1B～2级、3A级和4级,体内CD3+ CD44highT淋巴细胞的比例分别为29％、55％和75％,CD3+ CD62L-T淋巴细胞群落中CD44荧光强度分别为215、274和380,以及MLR强度(吸光度值)分别为0.29、0.45和1.0,与两对照组相比,实验组移植心存活时间明显缩短、记忆性T淋巴细胞比例明显升高、MLR强度均明显增强及排斥反应程度更严重(P＜0.05或P＜0.01).结论 同种小鼠皮肤移植后心脏移植模型是一个更为贴近临床实际的动物模型,其同种抗原反应能力明显强于过继输注同种记忆性T淋巴细胞的小鼠心脏移植模型,有利于免疫记忆的相关研究.     

大鼠肝移植后树突状细胞的迁移变化

目的：研究大鼠肝移植后树突状细胞（DC）的迁移情况。方法：制作Wistar大鼠到SD大鼠的肝移植模型（实验组），并设Wistar大鼠间肝移植作为对照（对照组）。分别于术后第3、5、7天处死受者，切取移植肝组织及腹腔淋巴结，进行组织学观察，并以免疫组织化学染色观察移植肝组织和淋巴结中S-100^＋DC的动态变化，以及CD25^＋T淋巴细胞在淋巴结的活化增殖。结果：肝组织病理学检查显示，实验组移植后第5天即出现轻至中度急性排斥反应，至第7天发展成中至重度排斥反应，受者存活时间（9．7±1．4）d。免疫组织化学染色显示，术后第3天实验组移植肝组织中DC数量明显增多，于第5天达到高峰，第7天则出现下降，明显高于对照组，差异有统计学意义（P〈0．05）。从第3天开始，淋巴结中DC数量明显增多，第5、7天持续上升，与对照组相比，差异有统计学意义（P〈0．05）。移植术后第3天，实验组淋巴结中CD25^＋T淋巴细胞明显增多，呈现明显的T淋巴细胞活化增殖反应。结论：同种异体肝移植后，DC对抗原的摄取和递呈加速，产生对T淋巴细胞强烈而持久的刺激，最终激活T淋巴细胞，导致排斥反应的发生。     

大鼠肝移植术后输注ω-3多不饱和脂肪酸对T淋巴细胞的影响

目的 探讨大鼠肝移植术后应用ω-3多不饱和脂肪酸对移植肝脏功能、受体T淋巴细胞和急性排斥反应的影响.方法 行BN(RTln)大鼠到Lewis(RT11)二袖套法大鼠肝移植18例,术后颈内静脉插管,微量泵匀速输注液体.生理盐水NS组(n=6)输注生理盐水,肠外营养PN组(n=6)输注营养液,脂肪酸OM组(n=6)输注营养液+ω-3脂肪乳.术后第7天处死大鼠,留取肝组织标本病理检查,取血清检测生化指标.取抗凝血0.5 ml,流式细胞仪检测CD4+、CD8+、CD4+CD25+T细胞和CD8+CD28-T细胞.结果 大鼠肝移植术后输注ω-3脂肪酸的OM组CD4+、CD8+、CD4+CD25+和CD8+CD28-T细胞下降,与Ns组比较差异有统计学意义(t=4.28,P<0.01;t=2.63,P<0.05;t=2.59,P<0.05;t=8.86,P<0.01).OM组CD4+、CD8+、CD4+CD25+和CD8+CD28-T细胞下降,与PN组比较差异有统计学意义(分别t=8.06,t=3.57,t=5.35.t=7.98,均P<0.01).OM组CD4+/CD8+比值下降,与NS组和PN组比较差异有统计学意义(分别t=2.41,t=8.74,均P<0.01).病理学检查移植肝排斥反应强度(rejection activity index,RAI)评分,NS组为7.17±0.98,PN组为6.17±0.75,OM组为4.33±0.52,OM组与NS组、PN组比较排斥反应减轻(分别t=6.25,t=4.92,均P<0.01).结论 静脉输注ω-3多不饱和脂肪酸可以抑制T淋巴细胞,显著降低CD4+辅助性T细胞比例,减轻排斥反应.抑制性T细胞和调节性T细胞与ω-3脂肪酸减轻大鼠肝移植排斥反应的效应无关.     

锌指蛋白A20促进同种异体大鼠小体积移植肝再生并抑制急性排斥

目的 探讨锌指蛋白A20对同种异体大鼠30%小体积移植肝再生与排斥及受体存活时间的影响.方法 采用急性排斥组合DA (RT1a)大鼠→Lewis (RT1l)大鼠建立同种异体大鼠30%小体积肝移植模型. 75只大鼠均分为A20腺病毒组(A20组)、对照空腺病毒组(rAdEasy组)及对照生理盐水组(PS组)3组. 供肝切取后采用离体门静脉灌注法转基因干预,肝脏灌洗后移植. 观察受体存活时间及排斥反应,检测移植肝A20表达、肝细胞再生与凋亡、肝血窦内皮细胞(LSECs)中NF-κB活性与ICAM-1 mRNA表达、移植肝浸润单核细胞(LIMCs)总数及自然杀伤(NK)细胞和自然杀伤T(NKT)细胞数以及血清IFN-γ水平. 结果 A20组受体大鼠存活时间长于PS组大鼠和rAdEasy组大鼠(P=0.001 8),而PS组大鼠存活时间又长于rAdEasy组大鼠(P=0.001 8). A20促进小体积移植肝再生,肝移植后4 d A20组大鼠肝细胞BrdU标记指数高于PS组大鼠和rAdEasy组大鼠(P＜0.01); A20组大鼠肝细胞凋亡指数低于PS组大鼠和rAdEasy组大鼠(P＜0.01). 肝移植术后4 d,组织学检测结果显示A20组大鼠移植肝有少量细胞浸润,呈轻度排斥; 而PS 组和rAdEasy组大鼠移植肝有大量细胞浸润,呈重度排斥. A20能抑制移植后早期(1 d) LSECs 中NF-κB活性和 ICAM-1 mRNA 表达. 流式细胞术检测结果显示A20能下调移植肝LIMCs数,包括下调NK和NKT 亚群细胞数,并下调血清IFN-γ水平(P＜0.05). 结论 A20能有效促进同种异体大鼠30%小体积移植肝再生,抑制排斥并延长受体存活时间,其功效可能与抑制LSECs中NF-κB活性、抑制LIMCs浸润及减少NK 细胞和NKT 细胞浸润入肝以及抑制肝细胞凋亡有关.     

联合输注受者Treg细胞和供者未成熟DC延长肝移植大鼠的存活时间

目的 探讨联合输注受鼠调节性T淋巴细胞(Treg细胞)和供鼠未成熟树突状细胞(imDC)延长同种肝移植大鼠存活时间的作用.方法 以DA大鼠为供鼠,Lewis大鼠为受鼠,采用改良二袖套法进行原位肝移植100例.采用随机数字表法将受鼠平均分为5组,急性排斥反应(AR)组、成熟树突状细胞(mDC)组、imDC组、Treg组及imDC+Treg组受鼠分别于术前5d经尾静脉注射生理盐水、供鼠的mDC、供鼠的imDC、受鼠的Treg细胞及供鼠的imDC+受鼠的Treg细胞.术后每组预留8只受鼠观察和记录存活时间.术后3、7、10d,检测各组肝功能指标,采用酶联免疫吸附试验法检测血清白细胞介素2(IL-2)、IL-10及转化生长因子β(TGF-β)的浓度 ;取各组受鼠移植肝组织进行病理学检查,采用原位末端标记法检测各组肝组织细胞的凋亡情况.结果 与其他4组相比,imDC+Treg组受鼠术后肝功能恢复明显较快 ;imDC+Treg组术后7d时外周血IL-10和TGF-β浓度均升高,IL-2浓度降低.imDC+Treg组移植肝组织仅有较少量的单核细胞浸润,属非确定型AR至轻度AR,术后10d开始出现肝细胞再生,有少量的中性粒细胞浸润 ;imDC+Treg组肝组织汇管区淋巴细胞凋亡数量高于mDC组,肝脏汇管区淋巴细胞凋亡数量最多.imDC+Treg组受鼠中位存活时间为37 d,明显长于imDC组的23 d和Treg组的15 d(P＜0.05),AR组和mDC组受鼠存活时间均未超过12 d.结论 单独输注供鼠的imDC或受鼠的Treg细胞均未能诱导同种肝移植大鼠的长期存活 ;而联合输注受鼠的Treg和供鼠的imDC能显著延长同种肝移植大鼠的存活时间.     

全身照射预处理供体对异基因大鼠肝移植的作用及对受体内CD4~+CD25~+调节性T细胞的影响

目的 探讨全身照射(TBI)预处理诱导大鼠肝移植术后急性排斥反应的发生机制,及CD4~+ CD25~+调节性T细胞的变化在诱导免疫耐受中的作用.方法 以雄性Lewis、DA大鼠为供、受体,随机分为正常对照组、同种肝移植组、自发免疫耐受组、急性排斥反应组.观察各组受体的生存时间及生存率,检测受体术后外周血中ALT、TB含量、Foxp3~+ CD4~+ CD25~+ 调节性T细胞和T细胞亚群上GITR的表达,检测受体术后第14天移植肝的病理变化和受体脾脏CTL杀伤活性.结果 自发免疫耐受组,术后经历短暂排斥反应最终获得免疫耐受并长期存活.急性排斥反应组,在术后第17～21天死亡,与其他组相比,外周血血清中ALT、TB含量明显升高,而Foxp3~+ CD4~+ CD25~+调节性T细胞比例明显降低.TBI预处理大鼠供肝致受体外周血中CD3~+ CD4~+ T细胞上GITR表达降低,CD3~+CD8~+T细胞上GITR表达增加,提高CTL的杀伤活性.结论 通过TBI清除供体大鼠肝移植物中携带的旁路淋巴细胞,致受体外周血中Foxp3~+ CD4~+ CD25~+调节性T细胞表达降低,而使CD3~+ CD8~+T细胞上GITR表达增加,共同诱导大鼠肝移植术后急性排斥反应发生和耐受障碍.     

肝移植急性排斥反应者外周血CD4+CD25+Foxp3+调节性T淋巴细胞的变化

目的 探讨良性终末期肝病患者肝移植术后外周血CD4+CD25+叉状头螺旋转录因子(Foxp3)+调节性T淋巴细胞在急性排斥反应期的变化及意义.方法 2004年12月至2008年1月间,符合入选条件的良性终末期肝病患者共55例,按照术后是否发生急性排斥反应分为排斥组(14例)和无排斥组(41例).肝移植术前用流式细胞仪检测患者外周血CD4+CD25+Foxp3+T淋巴细胞占CD4+T淋巴细胞的百分率(简称CD4+CD25+Foxp3+T细胞百分率),出院后1年内每隔3～6个月复查;发生急性排斥反应时,于治疗前和治疗缓解后(3～6个月)复查.比较两组患者外周血CD4+CD25+Foxp3+T细胞百分率的变化,对排斥组发生急性排斥反应时外周血CD4+CD25+Foxr3+T细胞百分率与排斥反应活动指数(RAI的相关性进行统计学分析.结果 肝移植术前,排斥组与无排斥组外周血CD4+CD25+Foxp3+T细胞百分率的差异无统计学意义(P＞0.05).排斥组患者发生急性排斥反应时外周血CD4+CD25+Foxp3+T细胞百分率为(2.23±0.54)%,低于无排斥组的(2.99±0.86)%,差异有统计学意义(P＜0.01).排斥组中,患者发生急性排斥反应时外周血CD4+CD25+Foxp3+T细胞百分率低于未发生急性排斥反应时的(3.67±0.70)%,差异有统计学意义(P＜0.01).排斥组患者发生急性排斥反应时外周血CD4+CD25+Foxp3+T细胞百分率与RAI呈负相关(r=-0.80,P＜0.01).结论 监测肝移植受者外周血CD4+CD25+Foxp3+调节性T淋巴细胞的变化,可辅助诊断急性排斥反应及判断其严重程度.

Abstract：

Objective To investigate the expression of peripheral blood (PB) CD4+ CD25+ Foxp3+ regulatory T cells (Tregs) in patients with benign end-stage liver disease after liver transplantation and the relationship between levels of PB Tregs and acute rejection. Methods A prospective analysis was performed on 55 consecutive patients who underwent liver transplantation.Fourteen out of 55 cases suffered from acute rejection after liver transplantation were defined as rejection group,while the rest patients were classified into no acute rejection group. PB was obtained from liver transplant patients at different time points longitudinally: pre-transplant, post-transplant within one year and acute rejection. The circulating CD4+ CD25+ Foxp3+ Tregs in PB were measured by flow cytometry. Blood samples were drawn during acute rejection, at the same time, liver biopsies were performed. The circulating CD4+ CD25+ Foxp3+ Tregs were compared between two groups.Results There was no difference between two groups in levels of circulating CD4+ CD25+ Foxp3 + Tregs cells pre-transplant. However, the levels of circulating CD4+ CD25+ Foxp3+ Tregs in rejection group were decreased significantly as compared with no-rejection group (2. 23 % ± 0. 54 % vs. 2. 99 % ±0. 86 %,P＜0.01). The frequency of CD4+ CD25+ Foxp3+ T cells was negatively correlated with rejection activity index (RAI) (r = - 0. 80, P＜0. 01 ). Conclusion Monitoring PB CD4+ CD25+ Foxp3+ Tregs levels may be helpful in evaluating the immune state and act as a more sensitive marker for acute rejection diagnosis in the patients following liver transplantation.     

输注供者CD8+CD28-调节性T淋巴细胞抑制大鼠肝移植急性排斥反应的作用

目的 评价具有免疫抑制作用的CD8+CD28-调节性T淋巴细胞(Treg)体内输注在抑制大鼠肝移植急性排斥反应中的作用.方法 建立近交系大鼠肝移植自发耐受及急性排斥反应模型.从肝移植自发耐受模型受者脾脏中分离CD8+CD28-Treg,于急性排斥反应模型建立前1 d输注给受者,比较不同的输注组间受者的存活时间和移植肝病理学表现.结果 来自自发耐受模型(LEW大鼠为供者,DA大鼠为受者)的CD8+CD28-Treg输注可以延长急性排斥反应模型(LEW大鼠为供者,BN大鼠为受者)受者的存活时间,由(14.0±2.2)d延长至(24.0±3.0)d(P＜0.01),移植肝病理学显示排斥反应程度减轻.结论 大鼠肝移植自发耐受模型受者体内诱导的CD8+CD28-Treg具有抑制急性排斥反应的作用,该免疫抑制作用具有抗原特异性.     

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.     

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.     

Immunomodulation in Transplantation with Photopheresis

Abstract: Photopheresis is a technique in which peripheral blood mononuclear cells, in the presence of a photoacti-vatable compound, are exposed extracorporeally to ultraviolet A light and reinfused, inducing a host autoregula-tory immune response. Experimental work and ongoing clinical studies are helping to define the role of this novel, safe, and non-toxic immunomodulating technology in the field of transplantation.