非协调性异种肝移植动脉化动物模型的建立

本研究旨在建立豚鼠至大鼠异种肝移植动脉化动物模型 ,观察移植肝的超急性排斥反应 ,现将结果报道如下。一、材料和方法1.动物 :供体为荷兰豚鼠 ,购自上海铁道医学院华亭实验动物养殖场 ,14 0～160 ｇ。受体为雄性ＳＤ大鼠 ,购自中国科学院上海实验动物中心 ,190～ 2 2 0 ｇ。术前不禁食水。2 .移植手术 :(1)供体手术 :供受体均为清洁手术 ,乙醚开放吸入麻醉 ,结扎均用 7 0尼龙线。手术在ＳＸＥ 1型手术显微镜 (上海医用光学仪器厂 )下进行 ,单人操作。豚鼠取上腹部横切口 ,游离肝脏 ,结扎左侧膈静脉。右肾上腺静脉结扎后剪断。游离下腔静脉…     

非协调性异种肝移植动物模型的建立

目的:建立豚鼠至大鼠异种肝移植的动物模型 。方法:利用血管套技术和显微外科技术进行了23例豚鼠至大鼠肝移植。观察存活时间、谷丙转氨酶（ALT）和移植肝病理变化、荧光染色 。结果:移植大鼠存活时间平均为135.10±46.12分钟,肝细胞发生弥漫性水样变性,IgG和IgM沉积于血管内皮细胞和肝血窦 。结论:豚鼠至大鼠异种移植模型存活时间有限,移植肝发生了超急性排斥反应。     

非协调性异种肝移植后再灌注障碍及超微结构变化的观察

目的: 探讨非协调性异种肝移植供肝再灌注障碍与超急性排斥反应的可能关系。方法: 应用改良缝合法建立豚鼠至大鼠的肝移植动物模型,观察供肝再灌注60分钟内门脉灌注和肝脏组织超微结构的变化。结果: 移植后60分钟供肝门脉灌注明显减少;肝细胞的线粒体明显肿胀,线 粒体嵴破坏、结构紊乱,内质网扩张、脱粒,肝细胞狄氏间隙消失,肝血窦内可见到血小板 和粒细胞粘附、聚集和血栓形成,部分内皮细胞消失。受体心肌细胞肿胀,肌原纤维排列紊 乱、疏松化和断裂,线粒体呈多形性,大小不等。结论: 豚鼠至大鼠非协调性异种肝移植60分钟时有超急性排斥反应的发生, 从而导致供肝的灌注障碍,同时心肌的受损可以进一步加重供肝的微循环障碍。     

供体骨髓间充质干细胞干预非协调性异种肝移植免疫排斥反应的实验研究

目的研究骨髓间充质干细胞(MSCs)对非协调性异种肝移植排斥反应的免疫干预作用。方法密度梯度离心法分离培养豚鼠MSCs,流式细胞仪检测其膜表面CD34、CD45、CD44和CD29的表达,脂肪细胞诱导液培养诱导MSCs向脂肪细胞分化。豚鼠MSCs输注大鼠后检测不同时相免疫球蛋白IgG、IgM、IgA以及补体C3、C4的浓度变化。豚鼠和大鼠各30只随机分为3组,所有大鼠受体经环磷酰胺预处理,A组为MSCs输注组;B组为生理盐水输注组;C组为地塞米松输注组。各组行豚鼠大鼠原位肝脏移植手术,观察受体的存活情况及排斥反应情况。结果MSCs膜表面CD34阴性、CD45阴性、CD44阳性、CD29阳性。脂肪细胞诱导液培养后细胞内出现脂滴沉着。MSCs细胞悬液输注受体后各个时相的免疫球蛋白IgG、IgM和补体C3较输注前有显著降低(P<0.01),而IgA和补体C4与输注前相比无明显变化(P>0.05),输注后的免疫球蛋白IgG、IgM和补体C3各个时相点之间的浓度变化无显著差异(P>0.05)。肝脏移植模型A组受体存活时间为(431±27)min,较B组和C组的存活时间[(148±16)min、(141±22)min]显著延长(P<0.01)。A组受体超急性排斥反应发生较迟,程度轻。结论MSCs的鉴定可根据细胞形态,膜表面标志物和分化能力来确定,MSCs可干预异种肝脏移植的超急性排斥反应的发生。     

非协调性异种气管移植的实验研究

目的探索异种气管移植免疫排斥反应特点,为解决供体气管来源提供新方向,并为研究肺移植继发的气道阻塞性疾病(OAD)建立理想的动物模型。方法建立SD大鼠颈部肌肉瓣包裹移植气管模型,以深低温冻储同种异体气管移植为对照,通过组织化学检查,免疫荧光检查,流式细胞术等方法,观察冷冻与非冷冻豚鼠—大鼠非协调性异种气管移植的成活情况,分析其免疫排斥反应的特点和机制。结果颈部肌肉瓣包裹深低温冻储同种异体SD大鼠长期存活。豚鼠—大鼠冷冻异种气管移植最长成活14 d,平均(13.2±0.75)d;新鲜异种气管移植最长成活9 d,平均(8.0±1.09)d。组织学检查,异体移植气管基本正常,气管通畅度大于80%。异种移植气管呈急性排斥反应表现,移植物大量嗜酸粒细胞,淋巴细胞,单核巨嗜细胞浸润;受体IgM,IgG,C3沉积;外周血CD4+T、CD8+T淋巴细胞明显升高;黏膜上皮剥脱,软骨失去活性;气管通畅度小于50%。以上表现随时间延长而加重,冷冻组弱于非冷冻组。结论细胞免疫反应参与的体液免疫反应为主的急性排斥反应是豚鼠—大鼠非协调性异种气管移植免疫反应特点。深低温冻储消减供体抗原,在一定范围内延长异种移植物成活时间。     

异种肝移植免疫排斥反应中脾脏的作用

目的 探讨脾脏在仓鼠到大鼠异种肝移植中的体液免疫,细胞免疫作用。方法 三袖套法建立仓鼠到大鼠原位肝移植模型,观察移植术后肝脏和脾脏的病理变化;采用补体介导的细胞毒检测异种肝移植术后血浆中抗仓鼠抗体滴度的变化;运用免疫组织化学的方法检测脾脏中大鼠抗体的产生,脾脏增殖细胞核抗原的表达;并观察环孢素Ａ,环磷酰胺,切脾对移植术后生存时间及免疫排斥反应的影响。结果 异种肝移植术后免疫排斥反应发生时,脾脏急剧     

大鼠完全动脉化辅助性肝移植的实验模型

本文通过建立大鼠完全动脉化辅助性肝移植模型，对辅助肝的支持作用，原残肝再生，移植肝萎缩等问题进行了研究。     

非协同性异种肝移植模型的探索

我们参照Ｋａｍａｄａ等的方法在成功建立大鼠同种原位肝移植模型的基础上 ,对豚鼠到大鼠的异种原位肝移植模型进行了探索。其主要操作过程与同种相似。由于豚鼠解剖结构的特殊性 ,在某些方面与同种又有所不同 ,主要表现在供肝手术过程方面。一、材料与方法ｌ.实验动物 :供体 :雄性豚鼠 2 0 0～2 50 ｇ ,由第二军医大学动物中心提供 ;受体 :雄性ＳＤ大鼠 2 50～ 30 0 ｇ,由上海寄生虫研究所提供。术前禁食 1 2～ 2 4ｈ ,不禁水。2 .手术 :(1 )麻醉 :供受体均用乙醚麻醉 ,术中给氧 ,术前半小时肌注阿托品0 .2ｍｇ。 (2 )供体手术 :麻醉稳定后…     

异种器官移植的新进展

目的总结异种器官移植的新进展。方法分析近年来异种器官移植进展的文献报道。结果随着免疫生物学的深入研究,异种器官移植取得了长足的进步,并开始应用于临床,但免疫排斥反应的诸多问题仍在探寻之中。结论异种移植为解决器官衰竭患者移植器官短缺的问题展现了广阔的前景,如何更有效地抑制排斥反应及延长移植物生存期是今后研究的重点。     

异种移植排斥机理的探讨

补体的激活是超急性排斥的中心环节，为了研究经典及旁路途径在这种排斥中的作用，本研究建立了体外超急性排斥模型。选择猪血管内皮细胞为人靶，人血清为天然抗体和补体源，用四唑盐法（ＭＴＴ）行补体依赖的细胞毒反应（ＣＤＣ）。人血清能溶解５８±５％的猪血管内皮细胞。加入ＥＧＴＡ阻断经典途径后人血清的溶细胞率降为５１±３％（Ｐ〈０．０１）。同样Ｃｌｑ缺乏的人血清仅溶解３７±７％猪血管内皮细胞（Ｐ〈０．００１）。     

Hemodynamic changes during reperfusion of the graft in an animal model of liver xenotransplantation

Our goal was to determine the hemodynamic changes that are witnessed during the initial minutes of reperfusion of the graft in liver xenotransplantation from pig to baboon. METHOD: We studied a group of 12 baboons undergoing transplantation of a pig liver via the classic technique with arterial anastomosis to the aorta. The anesthesia technique was similar to that used in humans. Hemodynamic monitoring, due to the size of the recipient, consisted of heart rate (HR), mean arterial pressure (MAP), and central venous pressure (CVP) recorded at the beginning and end of each of the three phases: preanhepatic (A1, A2), anhepatic (B1, B2), and neohepatic (C1 and C2). We aimed to maintain the following values by means of crystalloids, colloids, and blood derivates: HR >50 beats/minute; MAP >60 mm Hg; and CVP >10 mm Hg. RESULTS: Both HR and CVP remained unchanged throughout the procedure. MAP droped briefly after vascular clamping (B1) but not on reperfusion (C1). CONCLUSION: In cirrhotic patients there is an autonomic dysfunction, demonstrated as cardiovascular instability at times like the clamping of major vessels and reperfusion of the graft. On the other hand, the intact baboon has an intact nervous system. After vascular clamping, the sharp decrease in venous return lead to an adequate vasopressor response. Likewise, the extreme vasodilatation involved with reperfusion managed to maintain MAP above 70 mm Hg.     

A novel model for orthotopic liver transplantation in rats using hepatic rearterialization and biliary extradrainage system

Background

Although the rat orthotopic liver transplantation (OLT) model has existed for many years, only a few models can be applied for dynamic bile collection. The aim of this study was to introduce a dependent rat OLT model with hepatic rearterialization and an expediently dynamic bile collection system.

Methods

Forty-five male Sprague–Dawley rats were divided into the following three groups (n = 15 each): group A, OLT without hepatic rearterialization; group B, OLT with hepatic rearterialization; group C, OLT with hepatic rearterialization and a biliary extradrainage system. In groups B and C, a modified sleeve anastomosis between the donor common hepatic artery and the recipient proper hepatic artery was performed to restore the hepatic artery blood flow. In group C, after hepatic rearterialization, biliary extradrainage and jejunum stoma were performed to reestablish the bile flow, and a waistcoat-like external fixator was introduced to protect this system.

Results

The surgical success rates in groups A, B, and C were 100% (15/15), 93% (14/15), and 93% (14/15), respectively. In groups B and C, the hepatic artery patency rates were 93% and 86% on postoperative day 3 and postoperative day 21, respectively. Also, the liver function and bile duct integrity were preserved better than that in group A. In group C, the biliary extradrainage system was well preserved and bile collection was easily performed.

Conclusions

The rat OLT model with hepatic rearterialization and a convenient biliary extradrainage system was satisfactory in maintaining the survival rate, hepatic artery patency rate, and recovery of graft function, so it can be applied in various studies after transplantation.     

3D-printed titanium cages without bone graft outperform PEEK cages with autograft in an animal model

BACKGROUND CONTEXTModernization of 3D printing has allowed for the production of porous titanium interbody cages (3D-pTi) which purportedly optimize implant characteristics and increase osseointegration; however, this remains largely unstudied in vivo.PURPOSETo compare osseointegration of three-dimensional (3D) titanium cages without bone graft and Polyether-ether-ketone (PEEK) interbody cages with autologous iliac crest bone graft (AICBG).STUDY DESIGNAnimal study utilizing an ovine in vivo model of lumbar fusion.METHODSInterbody cages of PEEK or 3D-pTi supplied by Spineart SA (Geneva, Switzerland) were implanted in seven living sheep at L2-L3 and L4-L5, leaving the intervening disc space untreated. Both implant materials were used in each sheep and randomized to the aforementioned disc spaces. Computed tomography (CT) was obtained at 4 weeks and 8 weeks. MicroCT and histological sections were obtained to evaluate osseointegration.RESULTSMicroCT demonstrated osseous in-growth of native cancellous bone in the trabecular architecture of the 3D-pTi interbody cages and no interaction between the PEEK cages with the surrounding native bone. Qualitative histology revealed robust osseointegration in 3D-pTi implants and negligible osseointegration with localized fibrosis in PEEK implants. Evidence of intramembranous and endochondral ossification was apparent with the 3D-pTi cages. Quantitative histometric bone implant contact demonstrated significantly more contact in the 3D-pTi implants versus PEEK (p<.001); region of interest calculations also demonstrated significantly greater osseous and cartilaginous interdigitation at the implant-native bone interface with the 3D-pTi cages (p=.008 and p=.015, respectively).CONCLUSIONS3D-pTi interbody cages without bone graft outperform PEEK interbody cages with AICBG in terms of osseointegration at 4 and 8 weeks postoperatively in an ovine lumbar fusion model.CLINICAL SIGNIFICANCE3D-pTi interbody cages demonstrated early and robust osseointegration without any bone graft or additive osteoinductive agents. This may yield early stability in anterior lumbar arthrodesis and potentially bolster the rate of successful fusion. This could be of particular advantage in patients with spinal neoplasms needing post-ablative arthrodesis, where local autograft use would be ill advised.     

Segmental small intestine transplantation in dogs: comparison between a jejunal graft and an ileal graft]

The aim of this study was to compare segmental grafts of jejunum and ileum in a dog model. 14 segmental grafts, 8 ileal (Il. A) and 6 jejunal (Jej. A.), were successfully allografted as 120 cm-Thiry-Vella segments. Immunosuppressive therapy consisted of cyclosporin 25 mg/kg/day per os. Monitoring was performed by histology and absorption (maltose and xylose) studies as well as analysis of brush border enzymes. No cases of Graft-versus-host disease were observed. Six allografts (42.5 per cent) including 3 Jej. A. (50 per cent) and 3 Il. A. (37.5 per cent) were rejected during the first three months. Eight allografts (5 Il. A. and 3 Jej. A.) were tolerated for up to 3 months and were removed: 2 Il. A. and 2 Jej. A. were normal, while 2 Il. A. and one Jej. A presented with signs of chronic rejection and one Il. A. with advanced rejection. Jej. A. and Il. A. showed a similar course, by means of immunologic reactions as well as functional characteristics. It is concluded that there is no major difference between Jej. A. and Il. A. in the dog. Because of the specialized absorptive functions of the ileum and its adaptative properties, ileal segmental grafts should be preferred to jejunal grafts for the treatment of short-gut syndrome.     

Nitrofen-induced diaphragmatic hernias in rats: an animal model

In embryological terms, pathogenesis of congenital diaphragmatic hernia (CDH) associated with pulmonary hypoplasia is still unclear. However, it is known since 1971 that Nitrofen (2,4-dichloro-phenyl-p-nitrophenyl ether) can induce anatomical malformations in rats including diaphragmatic hernias. On order to establish an animal model of the embryogenesis of CDH, the effect of Nitrofen on the developing diaphragm was studied. Thirty-three pregnant female rats were exposed to Nitrofen. Five unexposed pregnant rats served as controls. In the first set of experiments, single doses of Nitrofen were given between the 9th and 13th day of pregnancy. In the second set of experiments, dosages of 50, 100, and 150 mg per animal were given on day 11 of pregnancy only. Postnatally the litters (469 newborn rats) were dissected to record the incidence of diaphragmatic malformations. The results were: (1) most hernias occurred after administration of 100 mg Nitrofen on day 9 (42%) and 11 (59%); (2) left-sided hernias were observed only after exposure to Nitrofen on day 9; (3) after exposure on day 10 or later all hernias were on the right side; and (4) Fifty-nine percent of the newborn rats exposed on day 11 had CDH. These results show that this model is suitable for further embryological investigations on the development of CDH.     

A polyurethane vascular access graft and a hybrid polytetrafluoroethylene graft as an arteriovenous fistula for hemodialysis: comparison with an expanded polytetrafluoroethylene graft

AIM: We evaluated a polyurethane vascular access graft (TVAG), a hybrid polytetrafluoroethylene graft (hPTFEG), and an expanded polytetrafluoroethylene graft (ePTFEG) for postoperative complications and graft patency in their use as prosthetic devices of vascular access for hemodialysis. METHODS: Between August 1993 and October 2001, we treated 200 patients in whom A-V fistulas were placed by the same surgeon. These were divided into the following four groups according to the type of blood access: 27 cases of ePTFEG, 23 cases of TVAG, 22 cases of hPTFEG, and 128 cases of an autogenous A-V fistula. We calculated the cumulative patency rates by the Kaplan-Meier method, including primary (problem-free) and secondary (revised or functional) patency rates. RESULTS: The hPTFEG group experienced few thromboses. The absence of perigraft edema in the TVAG group permitted the early use of the TVAG within a few postoperative days for hemodialysis. Among the three graft groups, the primary patency was the best in the hPTFEG group (94.7% at 1 year and 86.1% at 2 years), with a significant difference versus the ePTFEG group. In regard to secondary patency, hPTFEG had an excellent patency of 100% at 1 year and 90.9% at 2 years, and TVAG had a comparable patency with that of ePTFEG. CONCLUSION: The hPTFEG was considered superior to ePTFEG in terms of being complication-free and had the excellent 2 year secondary patency of 90.9%. TVAG, with a patency equal to that of ePTFEG, could be used immediately after implantation due to the absence of limb edema.     

大鼠肝癌肝移植模型的建立

目的　建立肝癌肝移植动物模型并观察术后肝癌复发的生物学特点。方法　 130只近交系SD雄性大鼠 ,10 0ppm二乙基亚硝胺饲喂诱癌。共 98只大鼠据Kamada袖套技术行原位肝移植 ,术中根据肿瘤大小分为三组 :1组有明确肝癌结节但直径 <1 0cm (n =2 5 ) ,2组肝癌结节直径1 0～ 1 5cm(n =4 1) ,3组肝癌结节直径 >1 5cm(n =32 )。不行肝移植术的 10只大鼠作对照组。结果　三组大鼠肝移植术中死亡率 2 6 5 % (2 6 / 98) ,术后 30d累计死亡率 71 5 % (70 / 98)。术后存活 30d后计算平均生存期 ,1组 (81 3± 33 2 )d ,2组 (6 7 6± 2 4 9)d ,3组 (5 4 4± 2 4 9)d。对照组从诱癌开始 15 0d后计算 ,平均生存期为 (2 9 4± 12 9)d。术后肝癌复发率 35 7% (10 / 2 8) ,单纯移植肝内复发7 1% (2 / 2 8) ,肝和肺同时复发 10 7% (3/ 2 8) ,肝和腹腔同时复发 3 6 % (1/ 2 8) ,单纯腹腔肿瘤 7 1% (2 /2 8) ,单纯肺部肿瘤 7 1% (2 / 2 8)。结论　大鼠肝癌肝移植良好地模仿了临床过程 ,但诱癌大鼠体质差导致术中和术后短期死亡率高。大鼠术后长时间存活是观察到肿瘤复发的重要条件 ,肝癌复发的形式多样。该模型为肝癌肝移植术后抗复发和复发机制研究提供了极好的平台。     

Experimental force measurements on a bifurcated endoluminal stent graft model: comparison with theory

The goal of this study was to experimentally validate a steady-state mathematical model, which can be used to compute the forces acting on a bifurcated endoluminal stent graft. To accomplish this task, an acrylic model of a bifurcated graft was used for the force measurements. The graft model was connected to the inlet piping with a flexible rubber membrane that allowed the graft model to move. This allowed us to measure the force owing to the movement of the graft model with a calibrated load cell. Steady-state blood flow was assumed, and the working fluid was water. The experimental data were found to be consistent with the results from a previously published mathematical model: the graft force is strongly dependent on the proximal or inlet pressure and the inlet area. The force tends to be weakly dependent on flow rate. More research work will be required to determine whether the steady-state force model examined in this article provides a realistic determination of the forces on an endoluminal stent graft that is subject to pulsatile blood flow.