Artificial Circulation of the Liver: Machine Perfusion as a Preservation Method in Liver Transplantation

Due to the sharp increase in liver transplant candidates and the subsequent shortage of suitable donor livers, an extension of the current donor criteria is necessary. Simple cold storage, the current standard in organ preservation has proven to be insufficient to preserve extended criteria donor livers. Therefore a renewed interest grew toward alternative methods for liver preservation, such as hypothermic machine perfusion and normothermic machine perfusion. These “new” preservation methods were primarily assessed in rat models, and only a few clinically relevant large animal models have been described so far. This review will elaborate on these alternative preservation methods. Anat Rec, 291:735–740, 2008. © 2008 Wiley‐Liss, Inc.     

肝细胞培养过程中酸碱度和溶解氧的关联控制

目的在生物型人工肝支持系统(BAL)中,设计一种能够精确控制溶解氧(D0)与酸碱度(pH)的控制方案.方法根据肝细胞培养过程中所需要的物料衡算,采用比例积分(PI)算法结合开关量控制、预测控制等方案,通过工控机构建关联控制系统,使得D0与pH的值相互关联.结果DO控制范围0%～200%,精度达到±5%;pH控制范围6～8,精度达到±0.05.结论经实验证实,本控制方案工作稳定,无静态误差,解决了培养过程中DO与pH相互影响的问题,可用于BAL中对肝细胞培养环境的控制.     

A new liver metastatic and peritoneal dissemination model established from the same human pancreatic cancer cell line: analysis using cDNA macroarray

To elucidate the mechanisms of metastasis, we established two sublines HPC-1H5 with a highly liver metastatic cell line and HPC-1P5a with a highly peritoneal disseminating cell line, which were sequentially selected from the parental pancreatic cancer cell line HPC-1. Using these three cell lines, we investigated several biological properties and mRNA levels of differentially-expressed genes involved in cancer metastasis by cDNA macroarray. Microscopic findings for the three cell lines were the same. The tumorigenicity, in vitro growth ability, motile activity, adhesive activity and the production of IL-8 of metastatic sublines were higher than those of parental HPC-1 cells. Particularly, HPC-1H5 cells showed clearly higher levels of IL-8 expression and tumors of HPC-1H5 cells grew faster and bigger than those of HPC-1P5a cells. In cDNA macroarray analysis of HPC-1H5 cells, 22 genes were up-regulated and 44 genes were down-regulated compared with parental HPC-1 cells. In HPC-1P5a cells, 9 genes were up-regulated and 28 genes were down-regulated compared with parental HPC-1 cells. This study provides a demonstration of global gene expression analysis of pancreatic cancer cells with liver metastasis and peritoneal dissemination. Furthermore, our results provide a new insight into the study of liver metastasis and peritoneal dissemination of human pancreatic cancer. This revised version was published online in July 2006 with corrections to the Cover Date.     

Survival and immunogenicity of dissociated allogeneic fetal neural dopamine-rich grafts when implanted into the brains of adult mice

Summary The survival of grafts of dissociated allogeneic fetal neural dopamine (DA) rich tissue in the striatum has been studied after transplantation between inbred strains of mice differing at defined immunogenetical loci between donor and recipient. Six to 7 weeks and 15 weeks after grafting, surviving grafted DA neurons were found in the brains of all the recipients, albeit with a large variation in numbers, located either within the striatum or within the adjacent lateral ventricle. The mean number of surviving DA neurons did not differ between the syngeneic controls and the histoincompatible donor-host combinations, and there was no difference in survival between grafts that differed at single or multiple major histocompatibility complex (MHC) loci, and those that differed at multiple non-MHC loci. The amount of inflammatory cells in the graft area did not differ between the groups, and none of the animals showed massive infiltration of inflammatory cells. The in situ immunogenicity of the grafted neural tissue after intracerebral implantation was monitored by means of Simonsen's alloimmunization test, at 6–7 weeks after transplantation, which provides a sensitive measure primarily of the cellular immunological response. Most, but not all, graft recipients showed immunization with a Spleen Index (S.I.) close to that seen in recipients of an orthotopical skin graft of the same histoincompatibility combination. In contrast to the prolonged survival of the intracerebral neural transplants, none of the skin grafts survived longer than 3 weeks, thus demonstrating the immunologically privileged status of the brain. We conclude that intracerebrally grafted allogeneic neural tissue is capable of provoking a cellular immune response. Despite host immunization, however, the dissociated fetal neural allografts survived for at least 15 weeks without any overt signs of rejection, regardless of the donor-host combination used.     

Xenografting of fetal pig ventral mesencephalon corrects motor asymmetry in the rat model of Parkinson's disease

Summary A suspension of cells from embryonic day 21 fetal pig ventral mesencephalon was transplanted into the striatum of 20 immunosuppressed rats with 6-hydroxydopamine-induced lesions of the nigrostriatal dopamine pathway. Of these rats, 15 showed reduction of amphetamine-induced ipsilateral rotation by 9 weeks and complete reversal of rotation by 14–17 weeks. Animals maintained stable reversal of rotations (contralateral direction) until cessation of Cyclosporin A (CyA) treatment at 15–20 weeks. Within 4–9 weeks after CyA removal, these rats showed exclusively ipsilateral rotations during behavioral testing which were comparable to pre-transplant levels, suggesting that the grafts were rejected upon cessation of CyA treatment. Rats were sacrificed and tyrosine hydroxylase (TH) immunohistochemistry was performed at several time points, both on and off CyA, to examine a possible correlation between the degree of rotational behavior and the number of TH- positive surviving grafted cells. Staining showed large numbers (230–12,329) of TH-positive surviving cells in animals displaying a high degree of rotational correction (1.6 to -9.6 net ipsilateral rotations/min) after cessation of CyA treatment. Two control groups, those transplanted with nonneuronal cells from the pig ventral mesencephalon (n=5) and those receiving only daily CyA injections (n=4) showed no significant reduction of net ipsilateral rotations throughout the experiment. No TH-positive surviving cells were seen in the one non-neuronal transplant analyzed. This data demonstrates long-term retention of xenografted tissue with immunosuppression and its concomitant restoration of normal motor behavior in the rat model of Parkinson's disease.     

人骨髓间质干细胞和嗅鞘细胞移植对大鼠急性脊髓损伤功能修复的比较研究

目的对比人骨髓基质细胞(BMSCs)与人胚嗅鞘细胞(OECs)移植对大鼠脊髓损伤功能修复的影响。方法将45只SD大鼠分成脊髓损伤后BMSCs移植组(BMSCs组)、OECs移植组(OECs组)和PBS对照组(PBS组),通过BBB评分、运动诱发电位(MEP)评估脊髓传导功能的改善状况,免疫组织化学方法检测移植细胞存活和分化情况,病理形态学方法观察组织结构修复情况。结果BMSCs组BBB评分高于OECs组(P<0.05);两细胞治疗组MEP潜伏期明显缩短(P<0.05);BMSCs组嗜银染色可见脊髓损伤近端有较多再生纤维向远端延伸,形成神经纤维束,而OECs组再生纤维较少;两种移植细胞均可在损伤处部分存活,BMSCs组可见BMSCs来源的细胞Nestin、NF、GFAP的阳性表达。结论BMSCs移植比OECs移植能更有效促进大鼠急性脊髓损伤修复。     

Beneficial effect of amrinone on murine cardiac allograft survival.

Amrinone is a non-glycoside positive inotropic agent with an inhibitory effect on a cyclic adenosine monophosphate (AMP) phosphodiesterase isoenzyme. In the present study, we examined the immunosuppressive action of amrinone, since several other cyclic AMP-elevating agents have been shown to suppress T lymphocyte activation. First, the in vivo effects of amrinone were investigated. Oral amrinone treatment, at 40 mg/kg per day, significantly prolonged median cardiac allograft survival compared with non-treated controls (22.0 days versus 10.5 days, P < 0.01) when DBA/2 mouse hearts (H-2d) were heterotopically transplanted into C57B1/6 mice (H-2b). Histopathological examination showed that there was less prominent cellular infiltration in the amrinone-treated than in the non-treated allografts. Plasma amrinone concentrations of mice after a single oral dose of 40 mg/kg were within the range of clinical relevance. To clarify the mechanism of action, in vitro studies were done. The generation of specific cytotoxic T lymphocytes after mixed lymphocyte culture was significantly suppressed by addition of amrinone to the culture medium at 5 micrograms/ml. The production of IL-2 and the interferon-gamma during mixed lymphocyte culture was also suppressed by amrinone at 5 micrograms/ml. However, the level of intracellular cyclic AMP in mouse splenic lymphocytes was not affected significantly by the same dose of amrinone. In conclusion, amrinone has immunosuppressive actions at the therapeutic doses, and it may be a beneficial agent for therapy against acute cardiac allograft rejection.     

Sequential respiratory syncytial virus cytomegalovirus pneumonia following bone marrow transplantation

A 6-month-old child with familial hemophagocytic lymphohistiocytosis (FHL) experienced early sequential pneumonia due to respiratory syncytial virus (RSV) and cytomegalovirus (CMV) following bone marrow transplantation (BMT). The patient was deficient in natural killer (NK) cell activity (as found frequently in patients with FHL), and this risk factor may have played a major role in the concomitant infection by the two viral pathogens. Rapid diagnostic methods for both viruses are essential and early specific treatment may serve to ameliorate RSV- and CMV-induced lung injury in these life-threatening infections. © 1995 Wiley-Liss, Inc.     

Autologous rib perichondrial grafts in experimentally induced osteochondral lesions in the sheep-knee joint: Morphological results

Summary The purpose of the present study was to examine the fate of autologous perichondrial grafts after transplantation into cartilage lesions in weight-bearing joints. Osteochondral lesions were made in the articular surface of knee joints in 36 sheep. The defects were filled with autologous rib perichondrial grafts which were secured by either collagen sponges (12 animals) or fibrin glue (12 animals). Defects without perichondrial grafts served as controls (12 animals). Following 1 week of immobilization of the operated leg, the plaster was removed and the animals were allowed to move freely. Animals were sacrificed after 4, 8, 12 and 16 weeks. The grafts were removed and investigated histologically. In contrast to weight-bearing areas and control defects, hyaline-like cartilage formation was seen in non-weightbearing areas after 4 weeks. This newly formed cartilage revealed strong metachromasia following staining with acidic toluidine blue and reacted positively with periodic acid-Schiff, indicating de novo synthesis of proteoglycans and glycoproteins. Scanning electron microscopy and examinations with polarized light confirmed a hyaline cartilage-like architecture for the surface area as well as for the fibre orientation of the whole graft. Enzyme histochemistry for alkaline and acid phosphatase activity showed positive reactivity only at the base of the transplants.     

Macrophage and perisinusoidal cell kinetics in acute liver injury.

Perisinusoidal cells (PSCs) are currently regarded as the major source of extracellular matrix proteins during hepatic fibrogenesis in response to liver injury. However, the cellular mechanisms underlying their response to injury are not fully understood. One hypothesis is that the PSCs are stimulated by peptide growth factors produced by hepatic macrophages (Kupffer cells) in response to parenchymal cell damage. In this study we have investigated the kinetics of the PSC and macrophage populations in acute carbon tetrachloride-induced hepatic injury in rats. PSCs were identified immunohistochemically by detection of cytoplasmic desmin; monocytes and macrophages were detected using the monoclonal antibodies ED1 and ED2; cells in S phase were identified by immunohistochemical detection of nuclear-incorporated bromodeoxyuridine. The results showed an expansion of the desmin-positive PSC population, predominantly within the damaged perivenular zones, which reached a peak on days 3 and 4 following administration of carbon tetrachloride; this was contributed to by local PSC proliferation. The PSC response was preceded by an expansion of the macrophage population resulting from both local macrophage proliferation and influx of blood monocytes. These results are in keeping with the hypothesis that the PSC response to acute liver injury is mediated, at least in part, by hepatic macrophages.