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。     

雷公藤多甙对大鼠原位肝移植急性排斥反应的影响

目的 探讨雷公藤多甙(TⅡ)对大鼠肝移植术后急性排斥反应的抑制作用和机制。方法 用“二袖套法”建立Wistar→SD大鼠原位肝移植模型，分对照组(n＝12)和TⅡ治疗组(n＝13)，移植术后第7d两组各杀死部分大鼠，测肝功能、肝组织病理和脾淋巴细胞IL—2活性，其余大鼠留作观察存活时间。结果术后第7d，TⅡ组肝功能损害和移植肝病理急性排斥反应程度轻于对照组，IL—2活性低于对照组。TⅡ组大鼠术后存活时间比对照组明显延长。结论 TⅡ可明显延长肝移植术后存活时间，减轻急性排斥反应程度。     

CTLA4-Ig抗大鼠肝移植排斥反应及诱导免疫耐受的实验研究

目的 建立大鼠原位肝移植（ROLT）急性排斥反应模型．探讨细胞毒淋巴细胞抗原4免疫球蛋白（CTLA4-Ig）抗排斥反应和诱导免疫耐受的作用。方法采用“二袖套管”法建立Wistar→SD大鼠配对组合的肝移植后排斥反应模型．并于术后第2天腹腔内一次性注射CTLA4-Ig（75pg／只大鼠）．与未给药的相同组合的排斥反应模型鼠对照研究．观察移植术后7d2组动物的一般情况、肝功能变化、移植肝病理改变及血清TNF-α水平的变化，同时观察CTLA4-Ig组动物术后4个月时的上述情况．以了解CTLA4-Ig抗排斥及诱导免疫耐受的作用。结果①对照组动物于肝移植术后6～14d内相继死亡；移植肝出现明显的排斥反应的病理改变征象。②CTLA4-Ig组动物于术后7d及4个月均未见明显的排斥反应表现．移植肝无明显的排斥反应的病理改变征象．血清TNF-α、ALT、AST、TBIL及DBIL水平均明显低于对照组（P〈0．05）．TP及A1b水平则明显高于对照组（P〈0．05）。结论CTLA4-Ig有抗排斥反应及诱导免疫耐受功能的作用；血清TNF-α水平作为观察ROLT后排斥反应的指标，可能有一定的参考价值。     

大鼠受体性别对肝移植效果的影响

目的探讨大鼠性别对肝移植效果的影响。方法根据大鼠受体性别将实验动物分为2组：雄性（M）组和雌性（F）组，比较两组术后急性排斥反应（ACR）发生率、术后7d肝功及术后6周生存率。结果F组大鼠肝移植效果优于M组，两组术后急性排斥反应的发生率、术后7d ALT及AKP水平、术后6周生存率具有显著性差异（P〈0．05或0．01）。结论性别对大鼠肝移植的急性排斥反应、生存率及术后肝功能的恢复有重要的影响。     

“二袖套法”大鼠原位肝移植的技术改进

目的 探讨大鼠原位肝移植(OLT)模型的技术改进方法,并观察移植后的排斥反应。方法 将“二袖套法”大鼠肝移植技术进行了改进;并行SD→SD,SD→Wistar大鼠肝移植各30例,观察术后排斥情况。结果 全组肝移植手术无肝期约为15min。大鼠无手术死亡。SD-SD大鼠肝移植后3周内存活率为97％;SD→Wistar大鼠肝移植后8～15d死亡,组织病理学证实存在不同程度的排斥反应。结论 采用该改良大鼠肝移植方法可明显缩短手术时间,降低术后并发症,提高移植大鼠的术后生存率。SD-Wistar大鼠的肝移植可作为较理想的研究肝移植排斥反应的动物模型。     

大鼠肝移植急排模型的建立及相关免疫指标的检测

目的:建立同种异体大鼠原位肝移植动物模型,观察急性排斥反应的发生发展以及相关免疫指标的变化过程.方法:Lewis大鼠与BN大鼠随机分为3组:正常对照组、同基因移植组及同种异基因移植组.观察大鼠存活率,移植组受体分别于术后3、5、7和10 d处死取标本,观察肝脏组织病理和超微结构变化,全自动生化分析法测定血清谷丙转氨酶(ALT)、总胆红素(total bilirubin,TBIL)和白蛋白(albumin,Alb)水平变化,ELISA检测血清IL-2含量.结果:在未用任何免疫抑制剂情况下,同基因组大鼠无急性排斥表现,14 d生存率为100%,肝组织发生轻度形态学改变,肝功能损害较轻,血清IL-2在正常范围.异基因组大鼠1 4 d内全部死亡,术后第7天肝组织病理改变出现典型急性排斥反应表现,肝脏功能损害较重,血清IL-2持续性升高,并在第7天达峰值.结论:Lewis大鼠与BN大鼠的组合方式.可以建立稳定的急排模型(急性排斥反应模型),在未用任何免疫抑制剂情况下,大鼠术后第7天急性排斥反应指标表现最为典型.     

TNF-α和IL-2在肝移植急性排斥反应中的表达及意义

目的 检测肿瘤坏死因子α(TNF-α)和白细胞介素2(IL-2)在肝移植术后急性排斥反应中的表达情况,以评价其作为肝移植术后急性排斥反应早期诊断指标的价值.方法 建立大鼠原位肝移植模型,应用荧光定量PCR法检测大鼠肝移植术后肝组织中TNF-α和IL-2基因的表达,以组织病理学作为急性排斥反应的诊断标准,研究其表达与急性排斥反应的关系.结果 术后3,5,7d异基因肝移植大鼠移植肝均有急性排斥反应发生.其肝组织TNF-α及IL-2表达水平均显著高于同期同基因肝移植大鼠肝组织的TNF-α,IL-2表达水平.结论 TNF-α和IL-2参与肝移植后排斥反应的发生,其表达可作为术后急性排斥反应的辅助诊断指标.     

热休克蛋白70与大鼠肝移植术后早期急性排斥反应的相关性研究

目的对热休克蛋白70（heat shock protein70，HSP70）与大鼠肝移植术后早期急性排斥反应进行相关性研究．探讨其中的免疫学机制。方法建立改良“二袖套法”大鼠原位肝移植模型，将大鼠分为A组（冷保存1h同基因组），B组（冷保存18h同基因组），C组（冷保存1h异基因组），D组（冷保存18h异基因组），术后收集大鼠肝脏组织和血清．用免疫组织化学及Western blotting方法检测HSP70在移植肝脏中的表达，观察其与病理学检查的相关性结果冷保存时间的延长可以诱导移植肝组织HSP70的高表达，移植肝HSP70表达水平的升高与大鼠原位肝移植术后早期急性排斥病理学评分之间存在着明显的正相关性（P〈0．05，r=0.928）．结论HSP70的升高可能与大鼠原位肝移植术后急性排斥的早期发生以及大鼠移植术后2周存活率密切相关．     

肝硬化大鼠原位肝移植模型的制作及术后排斥反应的观察

目的 制备肝硬化大鼠的原位肝移植模型,观察术后排斥反应发生情况,为进行其它研究创建一个平台.方法 以皮下注射CCl4联合饮用苯巴比妥钠和乙醇溶液的方法制备大鼠肝硬化模型,应用改良的"二袖套"法建立大鼠原位肝移植模型,同系移植者的供、受者均为SD大鼠(SD实验组),以接受肝移植的正常SD大鼠为对照(SD对照组);同种移植者的供者为Lewis大鼠,受者为BN大鼠(BN实验组),以接受肝移植的正常BN大鼠为对照(BN对照组).术后观察受者的存活情况以及移植肝的组织学变化.结果 肝硬化大鼠门静脉压力为(182.0±10.7)mm H2O,显著高于正常大鼠的(70.8±5.5)mm H2O(P＜0.01),移植后7 d降至(82.7±10.7)mm H2O.同种移植组术后5～12 d,移植肝组织中均可见中、重度急性排斥反应病理改变.同系移植者存活时间中位数均＞100 d;同种移植者中,BN对照组和BN实验组受者肝移植后存活时间中位数均为10 d.结论 以Lewis大鼠为供者、肝硬化BN大鼠为受者制备的肝移植模型术后排斥反应的发生率较高,可作为肝移植后排斥反应相关研究的平台.     

Telomerase activity in rat liver allografts

BACKGROUND: Telomerase activity in grafts may be involved in the alteration of cellular senescence after transplantation or its relevant immunological events. METHODS: At the age of 20 weeks, donor livers harvested from DA (RT1a) were orthotopically transplanted into PVG (RT1c) or LEW (RT1(1)) rats. Rats having undergone orthotopic liver transplantation (OLT; DA-PVG) naturally overcome rejection, whereas all OLT (DA-LEW) rats die from acute rejection within 14 days. Telomerase activity in liver allografts was measured at various intervals post OLT. RESULTS: At day 7 when the most severe rejection episode was observed in OLT (DA-LEW) and OLT (DA-PVG), the telomerase activity was significantly higher than in syngeneic OLT (DA-DA) rats, in which no rejection occurred. Telomerase activity in tolerogenic OLT (DA-PVG) livers remained elevated for at least 2 months. CONCLUSION: These results suggest that telomerase activity in allogeneic OLT livers may reflect regenerating hepatocytes or activation of lymphocytes and/or hematopoietic stem cells associated with rejection or tolerance.     

趋化因子IP-10及其受体CXCR3在大鼠肝移植急性排斥反应中的作用

目的探讨趋化因子IP-10及其受体CXCR3的表达在大鼠肝移植手术前后的动态变化,分析其与肝移植急性排斥(acute rejection,AR)的关系。方法改良"二袖套"法建立大鼠原位肝移植模型和急性排斥模型,分为4组:手术创伤组,肝移植无排斥组,肝移植急性排斥组,FK506组。ELISA法检测血清IP-10表达。流式细胞仪检测外周血淋巴细胞CXCR3的表达,用Cellquest软件分析阳性细胞百分率。半定量RT-PCR检测各组第7天肝脏组织CXCR3-mRNA的表达。结果①各组大鼠手术后外周血趋化因子IP-10及其受体CXCR3表达明显升高;②AR组在术后第5天起IP-10及其受体CXCR3表达均高于各对照组(P0.01);③AR组大鼠在移植后第7天,外周血IP-10和CXCR3的表达随着AR组RAI积分的升高而逐步升高,相关系数分别为0.89和0.92(P0.05)。结论血清中趋化因子IP-10及其受体CXCR3的高表达与AR密切相关,有望成为诊断AR较特异、敏感的指标。     

近交系大鼠DA到LEW肝移植急性排斥模型的特点

目的 探讨近交系大鼠DA到LEW原位肝移植模型的特点并判断排斥反应发生的强度.方法 采用Kamada二袖套法,利用封闭群大鼠SD和Wistar进行建模技能训练,在此基础上建立近交系大鼠DA到LEW肝移植模型,根据临床表现和Banff标准判断排斥反应发生的强度.结果 共施行DA到LEW大鼠肝移植模型15例,手术成功率86.7%,死亡原因为肝上下腔静脉漏血、肝下下腔静脉血栓、胆道梗阻.术后第3天开始出现排斥反应,7 d后逐渐达到高峰,除术后并发症致死外,其余均在12 d内死于Ⅲ级排斥反应.结论 DA到LEW为稳定、强烈的大鼠肝移植急排模型,是研究肝移植排斥反应及免疫耐受的理想动物模型.但近交系大鼠在组织结构上有其自身特点,给建模带来一定难度.     

The influence of cytomegalovirus viraemia on the outcome of recurrent hepatitis C after liver transplantation

BACKGROUND: Several interrelated host and hepatitis C virus (HCV) associated factors have been proposed to explain the variable outcomes in HCV recurrence. Recent evidence suggests that cytomegalovirus (CMV) infection not only is co-factor in progression of HCV recurrence but may precipitate allograft rejection. We investigated whether short-term CMV viremia influences HCV recurrence, the number and grade of acute rejection episodes, and the histological course of HCV recurrence during the first year after orthotopic liver transplantation (OLT) for HCV-related cirrhosis. METHODS: A cohort of 39 patients transplanted for cirrhosis HCV-related was analyzed. Patients were evaluated twice weekly for CMV infection by a blood polymerase chain reaction (PCR) assay. Triple therapy with cyclosporine or tacrolimus, azathioprine and prednisolone was the initial immunosuppressive regimen. Preemptive treatment with ganciclovir was started when two consecutive PCRs for CMV were positive. Liver biopsies were performed on day 7 after OLT or when indicated. A 3-day IV 1 g methilprednisolone was given to patients with moderate or severe rejection. Ishak's score was used to grade inflammation and to stage fibrosis. RESULTS: Neither CMV viremia nor CMV disease after OLT for HCV-related cirrhosis adversely influenced the incidence and grade of acute rejection episodes nor the histological outcome of post transplant HCV recurrence, during the first year after liver transplantation. CONCLUSION: CMV viremia as detected by PCR does not affect the progression of HCV recurrence in liver grafts.     

大鼠肝移植术后肝脏T淋巴细胞凋亡与免疫耐受的关系

目的探讨肝移植术后肝组织T淋巴细胞凋亡和肝移植免疫耐受之间的关系。方法采用Kamada二袖套法建立Wistar→Sprague-Dawley(SD)原位肝移植(OLT)大鼠模型。实验动物随机分为3组,每组各6只。A组:空白对照组,不作任何处理,采用SD大鼠;B组:免疫排斥组,Wistar大鼠为供体,SD大鼠为受体,行OLT;C组:免疫耐受组,Wistar大鼠为供体、SD大鼠为受体,行OLT,术前1周胸腺内注射F蛋白0.4mg,建立稳定的移植耐受大鼠模型。A组立即处死大鼠,B组和C组分别于术后7d、100d处死大鼠取肝组织,分别取各组大鼠肝组织标本进行冰冻切片,应用原位末端脱氧核苷酸转移酶标记法(terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling,TUNEL)在荧光显微镜下检测肝移植术后肝脏T淋巴细胞的凋亡情况。各组样本另取一张切片行常规苏木素-伊红(HE)染色在光学显微镜下观察,与TUNEL荧光染色法作对比观察。结果光学显微镜下,B组可见中、重度免疫排斥反应表现,C组肝组织细胞间的淋巴细胞浸润较B组大大减少,稍多于A组。荧光显微镜下,A组TUNEL切片可见零星散在的凋亡细胞,C组可见大量散在或密集分布的凋亡细胞,B组的凋亡细胞数远较C组减少,但仍多于A组。A组、B组、C组大鼠肝组织内浸润T淋巴细胞的凋亡指数(apoptosisindex,AI)分别为(8.83±0.43)%、(11.32±1.29)%和(19.00±1.96)%,两两比较差异有统计学意义(P<0.05～0.01)。结论免疫耐受移植物内浸润的T淋巴细胞凋亡明显增高,浸润的T淋巴细胞凋亡受阻可能会阻碍免疫耐受的发生,引起排斥反应。     

A study of tolerance induced by liver transplantation on intestinal graft in the rat]

In some strain combinations of rats, orthotopic liver transplantation (OLT) permits long-term donor-specific survival of fully allogeneic kidney, heart or skin grafts. The difficulties encountered in the clinical situation to obtain tolerance of small-bowel transplantation (SBT), in spite of massive non-specific immunosuppression, led us to study possible liver-induced tolerance in SBT. Inbred DA (RTIa) and PVG (RT1c) rats were used respectively as donors and recipients and divided in two groups: group 1: SIT alone (n = 6); group 2: combined OLT/SBT (n = 6). SIT was performed 17 days after OLT. No immunosuppressive treatment was given to the recipients. Biopsies of small-bowel grafts were performed in both groups at various times after small bowel engraftment. All animals in group 1 showed evidence of acute rejection of the graft between days 6 and 9 post-graft. The histologic pattern of rejection associated lamina propria (LP) mononuclear cell infiltration, crypt lesions and villous atrophy at the end-point of rejection. In group 2, long-term survival (> 100 days) of small bowel grafts was achieved in five of the six animals in spite of strong mononuclear cell infiltration in the LP, which peaked two months after small bowel grafting but then disappeared partially. This striking mononuclear cell infiltrate contrasted with only minor epithelial damage. These data demonstrate that liver grafting can enhance the survival of a small-bowel graft from the same donor in a rat model. Histological findings show that an intense immunological reaction takes place within liver-induced tolerated small-bowel grafts.     

The effect of selective inhibition of inducible nitric oxide synthase on cytochrome P450 after liver transplantation in a rat model

BACKGROUND: Activity levels of cytochrome P450 (CYP) provide markers for liver function and graft rejection episodes after orthotopic liver transplantation (OLT). Some in vitro studies have shown decreased CYP activation of inducible nitric oxide synthase (iNOS) in rejecting liver grafts. The aim of this study was to evaluate CYP isoenzyme activity changes in vivo and to examine histopathologic aspects during inhibition of iNOS after treatment with aminoguanidine (AG) using OLT in the rat. MATERIALS AND METHODS: Thirty DA-(RT1av1) rats that served as donors and LEWIS-(RT(1)) rats as recipients were divided into three groups: group I (controls, syngeneic rats; n = 6), group II (allogeneic rats without immunosupression; n = 11), and group III (allogeneic rats with AG treatment; n = 13). On postoperative days 5, 8, and 10 we performed laboratory investigations and liver biopsies for histopathologic investigations. RESULTS: On postoperative day 5, activities of CYP-1A1 and -3A4 were significantly lower (P = .022) in group III and the activity of CYP-1A2 higher (P < .05) compared with group II. At postoperative days 8 and 10, the activities of all CYP isoenzymes were significant higher in AG-treated rats (group III) in contrast with group II after allogeneic OLT without immunosuppression. Histopathologic findings revealed less distinct rejection signs in group III specimens after AG treatment compared with group II. CONCLUSION: Summarizing our results, we concluded that AG treatment led to increased CYP activity and less distinction of graft rejection after OLT in rats.     

The utility of noninvasive serologic markers in the management of early allograft rejection in liver transplantation recipients.

BACKGROUND: Early allograft rejection after orthotopic liver transplantation (OLT) currently requires a biopsy for diagnosis. Alpha-glutathione S-transferase (alpha-GST) and Pi-glutathione S-transferase (Pi-GST) are potential noninvasive markers of hepatocyte and biliary epithelial cell injury. Our aim was to determine the utility of noninvasive serologic markers in the management of early hepatic allograft rejection. METHODS: Forty-four of 52 consecutive adult patients undergoing primary OLT at the University of Florida were included in the study. All had protocol liver biopsies between days 6 and 8 after OLT. Serum alpha-GST and plasma Pi-GST were determined using a sandwich enzyme immunoassay (Biotrin International, Dublin, Ireland). All biopsy specimens were retrospectively reviewed and scored for rejection and cholestasis. RESULTS: The biopsy specimens were scored for rejection as moderate to severe in 14 patients (group 1) or none to mild in 30 patients (group 2). Group 1 had statistically higher mean levels than group 2 for alpha-GST on days 6, 7, and 9; alanine aminotransferase on days 6 and 9; aspartate aminotransferase (AST) on days 6 and 7; alkaline phosphate (AP) on days 3 through 7, 9, and 10; and gamma-glutamyl transferase on day 3. No differences between groups were seen with Pi-GST or total bilirubin. Between days 6 and 8, the following values were found more frequently in group 1 than group 2: alpha-GST level >15 ng/ml (11/14 vs. 14/30; P<0.01); AST >100 U/L (8/14 vs. 2/30; P=0.002); and AP >120 U/L (14/14 vs. 17/30). Combining AP with either alpha-GST or AST led to improved detection of rejection over any single marker alone. In the first week after the initiation of rejection treatment, alpha-GST was the only marker that accurately predicted response. CONCLUSION: Serum alpha-GST may be useful in the management of early hepatic allograft rejection. A combination of noninvasive markers may be beneficial to diagnose early hepatic allograft rejection.     

乙型肝炎相关性肝病肝移植术后的急性排斥反应

目的 研究乙型肝炎相关性肝病肝移植术后急性排斥反应的发病率、治疗和预防。方法前瞻性地研究用肝移植术治疗乙型肝炎相关性肝病100例，分析急性排斥反应的发病相关因素，急性排斥反应和免疫抑制剂治疗的动态监测及二者间的联系。结果临床型急性排斥反应的发病率为12％，急性排斥反应发生前3～5d，有明显的免疫抑制剂浓度降低的过程。FKS06为基础的免疫抑制方案，加用骁悉，可有效地终止、逆转急性排斥反应；和以甲基强的松龙冲击治疗急性排斥反应相比较，副作用少，但肝功能的完全恢复时间相对较慢。结论乙型肝炎相关性肝病的肝移植术后急性排斥反应的发生率相对较低；和急性排斥反应发生相关的免疫抑制剂低浓度是诱导急性排斥反应的重要相关因素；FK506为基础的免疫抑制方案，可有效地终止、逆转急性排斥反应，且副作用少。