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Undifferentiated small-cell hepatoblastoma (HB) is a rare malignant tumor of childhood. The cell of origin is supposed to be a pluripotential, probably entodermal, stem-cell. Differential diagnosis of this type of HB is difficult among the group of small round and blue cell malignant tumors of children. The immunohistochemically determined coexpression of cytokeratin 8, 18, and 19 and of vimentin and actin, regularly in the absence of alpha-fetoprotein expression may be diagnostically helpful. We present the case of an undifferentiated small-cell HB of a 15-month-old girl with agenesis of the right kidney. As morphological peculiarity the tumor presented disseminated histiocytic giant cells.

We report on a 43-year-old man with a primary sarcoma of the liver. The patient was admitted to the hospital for evaluation of dyspnea, abdominal pain in the right upper quadrant, diarrhea, and fever. Physical examination revealed hepatomegaly. Increased laboratory values were found for gamma-GT, LDH, CA 125, and NSE, but not for aspartate and alanine aminotransferase. Computed tomography presented a tumor in the right lobe of the liver. Venous cavography revealed a caval tumor thrombus reaching up to the right atrium. Major liver resection combined with replacement of the vena cava inferior was proposed, but before operation the patient complained about shortness of breath. Spontaneous fragmentation of the tumor thrombus with consecutive embolization of the lungs was suspected. Despite lysis therapy the patient died because of right ventricular failure. Autopsy revealed a tumor measuring 8 cm in diameter, which was located in the right lobe of the liver and invaded the inferior vena cava. Because of multiple tumor aggregates seen in the left and right main pulmonary arteries acute tumor embolization of the lungs was regarded as cause of death. Histologically the tumor was composed of bizarre giant cells surrounded by irregular spindle cells. The positive immunoreactivity pattern of the tumor cells for vimentin, lysozym, and CD68 justified the diagnosis of a malignant fibrous histocytoma (MFH) of the liver.

The Budd-Chiari syndrome is one cause of portal hypertension with multiple etiology and different therapeutic interventional strategies. We report on a 23-year-old female patient who developed de novo liver tumors 33 months after portocaval shunting for acute Budd-Chiari syndrome.

Durch Sonographie, Farb-Doppler-Technik, Computer- und Magnetresonanztomographie sowie szintigraphische Methoden gelingt in aller Regel eine gute Differenzierung der haufigsten benignen Lebertumoren. Erganzt wird diese naturlich durch klinische und humorale Untersuchung unter Einschlus von Tumormarkern, um die Verdachtsdiagnose maligne oder benigne zu untermauern. Die Biopsie sollte weitgehend vermieden werden, da die meistens sichere Diagnostik eindeutig nichtmaligner Strukturen durch die genannten Verfahren moglich ist und malignitatsverdachtige Strukturen ohnehin eine Operation notwendig machen, sofern der Zustand des Patienten dies erlaubt. In dieser Arbeit werden nur die benignen soliden Lebertumoren behandelt, nicht die (poly-)zystischen, parasitar zystischen Lebererkrankungen und Abszesse.

Indefinite tolerance to kidney allografts across a two-haplotype class I disparity can be induced in miniature swine in 100% of cases by a short course of cyclosporin A (CyA). Without CyA, all recipients reject kidney allografts within 2 wk. These animals therefore provide a unique opportunity to study the mechanisms of induction and maintenance of tolerance in a large animal model. Previous studies of cellular and humoral immunity suggested that a T cell help deficit at the time of the first exposure of the host's immune system to alloantigens was involved in tolerance induction. We have now studied the effect of exogenous T cell help in the form of an IL-2 infusion during both the induction and maintenance phases of tolerance. Lymphoid infiltrates were seen in class I mismatched renal allografts by day 8 in all animals whether treated with CyA or not. Administration of i.v. IL-2 on postoperative days 8, 9, and 10 to animals receiving the full CyA tolerizing regimen led to acute rejection in four of four animals. These rejecting animals showed induction of IL-2R expression on graft infiltrating cells in the kidney, suggesting that the infiltrates present before IL-2 administration were capable of causing rejection once T cell help was provided. Treatment with IL-2 did not abrogate long-term tolerance. Thus, limitation of T cell help at the time of first exposure to Ag in this model appears to be required to prevent rejection during the time required for active tolerance to develop. Once established, this tolerance does not appear to require continuous limitation of T cell help to be maintained, suggesting loss, inactivation, or suppression of the cells capable of causing rejection.

The critical issue before major hepatic resection is to evaluate and detect patients with a potentially increased risk of hepatic failure. In this study the prognostic value of the monoethylglycinexylidide (MEGX)- liver function test was evaluated with regards to clinical course and survival after partial liver resection.Between 1995 and 2000 a total of 55 patients (29 male, 26 female) underwent a partial liver resection at the Georg-August University of Göttingen. Forty-two patients were treated for malignant, and 13 for benign, disease. MEGX-testing was performed 15 and 30 minutes after a single-dose of 1mg/kg BW Lidocaine i.v. was applied.MEGX-test results after 30 minutes had significant influence on hospital mortality. Patients who died during the hospital stay showed median MEGX-30 minutes results of 32 microg/L in (4-107 microg/L) in comparison to the surviving patients with a median 68 microg/L (16-176 microg/L) (p = 0.026). Furthermore, patients with MEGX scaled categories of 3 and 4 had a significantly lower surivial at 150 days (p = 0.008) and overall (p = 0.0002). There was an indirect impact of MEGX on hospital stay, costs and mortality reflecting high fluid loss: patients with lower loss of fluid over drainages had a significantly lower mortality at 150 days (p = 0.00046) and overall (p = 0.00008), than did patients with higher fluid loss. Low MEGX-values significantly influenced long hospital stay (p = 0.00001) and high costs (p = 0.00001). Pathologic MEGX in combination with increased age, increased BMI and extensive surgical procedures including resection of over 50% volume of the liver had a significant influence on complications (p = 0.015).The preoperative MEGX-test, especially the 30 minutes value, is a useful medium to estimate the liver reserve in non-cirrhotic patients prior to liver resection. In combination with the resection volume it may be very useful to identify patients with a high risk of developing a postoperative liver failure.

von Willebrand factor (vWf) is an adhesive glycoprotein known to play a role in hemostasis and in tissue injury. It is found in high levels in plasma of patients with acute hepatic failure and chronic liver disease. The aim of this study was to investigate the pattern of tissue vWf in acute liver failure in humans.We studied vWf immunostaining and mRNA expression in the liver of three patients with fulminant liver failure, two patients with chronic liver disease, and two controls. PECAM-1 (CD31) immunostaining and mRNA expression were used as an additional endothelial marker.In chronic liver cirrhosis, vWf deposits were strongly detected at the scar-parenchyma interface. In fulminant hepatic failure, intense deposits were seen in tissue sections in the area of necrosis. A similar pattern of immunostaining was seen with PECAM-1. vWf transcripts were abundant in the liver of patients with chronic disease and minimally expressed in patients with acute hepatic failure and in controls.vWf is deposited within the liver sinusoids early after liver damage. The factor is only partially produced locally during the acute phase of the disease, but is overproduced in chronic disease states. These changes may suggest a role for vWf in liver injury and repair.

Background Ischemia-reperfusion injury (IRI) can result in severe organ dys- or nonfunction. Interaction of leukocytes and endothelial cells mediated by E-selectin appears to be a key step for disturbed microcirculation. Therefore we studied gene and protein expression as well as localization of E-selectin during intestinal IRI. Methods Intestinal tissue samples were obtained from extracorporeal perfused intestines (cold ischemia time [CIT] 2 or 20 hours, each n = 5) and additionally in intestinal transplanted pigs (CIT 2 or 20 hours, each n = 1). Mucosal damage was graded according to the Chiu classification. E-selectin mRNA was determined by PCR and quantitative RT-PCR. Localization of E-selectin mRNA was performed by in situ hybridization and of the protein by immunohistochemistry. Results Histologically, mucosal damage occurred during reperfusion and was earlier and more severe after 20 hours of CIT. E-selectin mRNA expression was detected by PCR already after laparotomy and was elevated after reperfusion. Interestingly, mRNA expression was already increased after 20 hours of CIT. E-selectin mRNA was localized to the luminal surface of muscular, submucosal, and mucosal endothelial cells and the protein was detected on submucosal arterial endothelium as early as 2 hours after reperfusion. Conclusion Prolongation of CIT results in more severe mucosal damage during reperfusion, which is associated with protein expression of E-selection that might be used as a marker for activated endothelial cells. Increased E-selectin mRNA at end of 20 hours of CIT might indicate a preactivated state of endothelial cells potentially triggered by bacterial translocation or products.

Der »Wissenschaftliche Beirat der Bundesarztekammer« definiert den Hirntod »als Zustand der irreversibel erloschene Gesamtfunktion des Groshirns, des Kleinhirns und des Hirnstamms. Dabei wird durch kontrollierte Beatmung die Herz- und Kreislauffunktion noch kunstlich aufrechterhalten. Mit dem Hirntod ist naturwissenschaftlich-medizinisch der Tod des Menschen festgestellt.« Liegt diese Voraussetzung vor und hat die/der solcherart Verstorbene vormals in eine Organentnahme eingewilligt, so kann eine Organexplantation vorgenommen werden.

We present a 40-year-old female patient with epigastric pain, ascites, and progressive liver failure, caused by Budd-Chiari syndrome (BCS) with thrombotic occlusion of the right and middle hepatic veins. As underlying diseases, essential thrombocythemia and resistance to activated protein C (APC) due to heterozygote factor V Leiden were found. Initial therapy with heparin caused thrombocytopenia (HIT) type II culminating in thrombosis of the last patent left hepatic vein and further deterioration of liver function. The decision against a surgical shunt and liver transplantation by our surgeons on the basis of the risks involved, prompted us to insert a transjugular intrahepatic portosystemic stent-shunt (TIPS). There was no measurable flow signal in the doppler sonography of the portal vein presumably due to thrombosis. A further evaluation with magnetic resonance tomography and angiography was impossible due to movement artefacts. TIPS initially served as a diagnostic tool allowing direct angiography-diagnosed thrombosis of the portal vein, the superior mesenteric and the splenic vein respectively. However, insertion of the TIPS shunt and subsequent fragmentation led to an effective hepatic decompression and full recanalisation of the portal vein. In the present case TIPS simultaneously allowed the diagnosis of portal vein thrombosis and served as rescue therapy of complicated Budd-Chiari syndrome. The potential development of HIT type II should be kept in mind when heparin is given, especially to patients with thrombophilia.

Inflammatory leukocyte-endothelium interactions, mediated by selectins, contribute to renal ischemia/reperfusion (I/R) injury. We examined the influence of the soluble P-selectin glycoprotein ligand 1 (sPSGL) on early I/R-induced changes in a rat kidney transplantation model with long cold ischemia.After 24 hr of cold storage, syngeneic kidneys were grafted into bilaterally nephrectomized rats. Before transplantation, recipients received either 1 mg/kg of sPSGL or vehicle (n=8 per group). Six hours after reperfusion, grafts were removed for light microscopy and immunohistochemistry. Capillary blood flow was measured under a fluorescence microscope by using the concentric-circles method.A greater proportion, 74.7+/-7.2% (sPSGL) vs. 28+/-7.4% (controls), of all dye-labeled outer medullary capillaries appeared in the 12-microm radius (P0.01), indicating dense blood flow, whereas 7.6+/-2.9% vs. 43.3+/-9.7%, respectively, appeared in the 60-microm radius (P0.05), indicating rarefied blood flow. In the sPSGL-treated group, the extent of severe tubular damage within the inner stripe of the outer medulla was lower compared with controls (37.5+/-8.3% vs. 78.4+/-3.5%, P0.01). Outer medullary heat shock protein 72 expression was 14.5+/-1.6% in the sPSGL-treated group compared with 9.6+/-1.4% in controls (P0.05). The number of infiltrating polymorphonuclear leukocytes was similar in both groups. Treatment with sPSGL had no influence on the serum creatinine level.Our data suggest that impairment of outer medullary blood flow is crucial in I/R injury of kidney grafts with prolonged cold storage. Reduction of capillary blood flow perturbations by sPSGL protects tubular cells from severe structural damage. Blocking early selectin-mediated leukocyte adhesion may have therapeutic implications in improving the prognosis of renal transplants with severe I/R injury.

Undifferentiated small-cell hepatoblastoma (HB) is a rare malignant tumor of childhood. The cell of origin is supposed to be a pluripotential, probably entodermal, stem-cell. Differential diagnosis of this type of HB is difficult among the group of small round and blue cell malignant tumors of children. The immunohistochemically determined coexpression of cytokeratin 8, 18, and 19 and of vimentin and actin, regularly in the absence of alpha-fetoprotein expression may be diagnostically helpful. We present the case of an undifferentiated small-cell HB of a 15-month-old girl with agenesis of the right kidney. As morphological peculiarity the tumor presented disseminated histiocytic giant cells.

According to its different location, clinical features, treatment modalities and prognosis, intrahepatic cholangiocarcinoma should be well differentiated from proximal bile duct carcinoma. There is no therapeutic measure with curative potential apart from surgical treatment. Partial or extended hepatectomy is the treatment of choice in cholangiocarcinoma. Thereby, hilar resection in combination with hepatectomy is increasingly performed in proximal bile duct carcinomas. In most centers liver transplantation is not considered as a therapeutic option for irresectable cholangiocarcinomas.

We report on a 43-year-old man with a primary sarcoma of the liver. The patient was admitted to the hospital for evaluation of dyspnea, abdominal pain in the right upper quadrant, diarrhea, and fever. Physical examination revealed hepatomegaly. Increased laboratory values were found for gamma-GT, LDH, CA 125, and NSE, but not for aspartate and alanine aminotransferase. Computed tomography presented a tumor in the right lobe of the liver. Venous cavography revealed a caval tumor thrombus reaching up to the right atrium. Major liver resection combined with replacement of the vena cava inferior was proposed, but before operation the patient complained about shortness of breath. Spontaneous fragmentation of the tumor thrombus with consecutive embolization of the lungs was suspected. Despite lysis therapy the patient died because of right ventricular failure. Autopsy revealed a tumor measuring 8 cm in diameter, which was located in the right lobe of the liver and invaded the inferior vena cava. Because of multiple tumor aggregates seen in the left and right main pulmonary arteries acute tumor embolization of the lungs was regarded as cause of death. Histologically the tumor was composed of bizarre giant cells surrounded by irregular spindle cells. The positive immunoreactivity pattern of the tumor cells for vimentin, lysozym, and CD68 justified the diagnosis of a malignant fibrous histocytoma (MFH) of the liver.

Objective: Renal-transplant patients who are immunosuppressed with cyclosporin A (CyA) are often treated with proton-pump inhibitors to prevent ulcer disease. No data are available on the effect of the novel proton-pump inhibitor pantoprazole on CyA levels. Methods: In a controlled treatment, we investigated the effect of pantoprazole, which was administered in a pragmatic schedule for acid suppression (40 mg as single oral dose at 2200 hours) in six renal-transplant patients who received CyA (Sandimmun optoral, 50–175 mg twice daily) and prednisolone (5–7.5 mg/24 h). CyA trough levels (0730–0800 hours) were measured by immunoassay. Results: In the absence of pantoprazole, mean CyA trough levels measured on three consecutive days were between 164 ng/ml and 173 ng/ml (therapeutic range 120–200 ng/ml). Pantoprazole did not affect CyA trough levels during an observation period up to 3 months long. Conclusions: Pantoprazole seems to be a safe drug in combination with CyA.

Partially inbred miniature swine have been developed in this laboratory as a large animal model for studies related to transplantation tolerance and as a source of hematopoietic cells and organs for xenotransplantation. The identification of swine CD3 specific mAbs capable of activating or depleting T cells in vitro and inducing an immunosuppressive state in vivo greatly facilitates studies of the swine immune system, transplantation tolerance and xenotransplantation research. Flow cytometry was used to determine the phenotypic profile of the swine specific mAb 898H2-6-15 (2-6-15). The specificity of 2-6-15 was further defined biochemically by surface labeling and immunoprecipitation. The ability of this mAb to activate pig T cells in vitro was examined by several criteria including proliferation assays, calcium flux analysis and detection of surface CD25 upregulation by fluorescence activated cell sorter (FACS) analysis. Monoclonal antibody 898H2-6-15 is specific for swine CD3 and is capable of inducing proliferation and CD25 upregulation in cultured swine peripheral blood lymphocytes. In addition, it induces calcium flux in purified pig T cells. Surprisingly, in contrast to described antibodies to CD3 in swine and other species, the binding of this antibody to porcine CD3 is dependent on the presence of extracellular calcium. Thus calcium was required in order to immunoprecipitate labeled surface molecules for biochemical analysis and to stain cell surfaces for FACS analysis of swine lymphocytes. In this paper, we describe a new swine CD3 specific mAb, 898H2-6-15 (2-6-15) the characteristics of which make it an extremely useful tool for in vitro and in vivo studies of the swine immune system and xenotransplantation. The availability of swine T cell specific reagents should facilitate the monitoring of swine T cell engraftment and/or release amongst xenogeneic mixed chimeras and thymic transplant recipients as well as provide a means to treat potential GvHD across xenogeneic barriers. We are currently evaluating the in vivo effects of 2-6-15 in the pig.

The 5-year survival of colorectal cancer patients with distant metastases is below 30%, despite the development and use of a variety of chemotherapeutic regimens. Therefore, new therapeutic strategies are warranted. Whereas radioimmunotherapy (RIT) has shown disappointing results in bulky disease, it may be a promising therapeutic alternative in limited and small volume disease. The aim of this study was, therefore, to compare, in a preclinical study, the therapeutic efficacy of RIT in colorectal cancer to equitoxic chemotherapy, as well as to evaluate, in a pilot clinical trial, its efficacy in small volume disease. Nude mice, bearing subcutaneous or metastatic human colon cancer xenografts, were injected either with the unlabeled or 131I-labeled monoclonal antibodies (MAbs), CO17-1A (which is a murine IgG2a directed against a 41-kD membrane glycoprotein) or F023C5 (which is an anti-CEA MAb of murine IgG1 subtype), or were administered 5-fluorouracil/folinic acid (5-FU/LV) at equitoxic doses. In a pilot clinical study, 10 colorectal cancer patients with small volume metastatic disease (all lesionsor = 3 cm) have been entered so far in an ongoing mCi/m2-based dose escalation study with the 131I-labeled F023C5. In the animals, the maximum tolerated activities (MTD) of 131I-labeled CO17-1A and F023C5 were 300 microCi and 600 microCi, respectively, corresponding to blood doses of approximately 15 Gy each. Accordingly, myelotoxicity was dose-limiting. The MTD in the chemotherapy group was 0.6 mg 5-FU/1.8 mg LV, given as intravenous bolus 1 h apart for 5 subsequent days. Whereas no significant therapeutic effects were seen with both unlabeled MAbs or 5-FU/LV chemotherapy, tumor growth was retarded significantly with both radiolabeled antibodies. In the metastatic model, chemotherapy prolonged life for only a few weeks, whereas RIT led to cures in 35-55% of the animals. As was the case in the animals, myelotoxicity seems to be dose-limiting in patients as well. Encouraging anti-tumor effects were observed, lasting for up to more than 12 months. These data suggest that radioimmunotherapy may be a viable therapeutic option in colorectal cancer patients with limited disease. Myelotoxicity is the only dose-limiting organ toxicity. Although most patients were treated below the MTD, anti-tumor effects are encouraging. Further studies are ongoing.

We investigated the prophylactical administration of liposomal amphotericin B (Ambisome®) in the early phase after liver transplantation (LTx). Fifty-eight patients received Ambisome® prophylactically after LTx. Ambisome® (1 mg kg -1 day -1 ) was given intravenously for 7 days after LTx. Immunosuppressive prophylaxis was cyclosporin A (CsA) based in 11 patients. Forty-seven patients had a tacrolimus-based immunosuppressive regimen. CsA and tacrolimus dosages were adjusted to trough levels of 150-250 ng ml - (EMIT) and 5-15 ng ml - 1 (MEIA II) respectively. Three patients died from sepsis due to Aspergillus fumigatus infection. Reasons for a fatal outcome were foudroyant Aspergillus pneumonia in a patient transplanted for fulminant hepatic failure on post-operative day (pod) 8; Aspergillus sepsis with severe endocardidtis in a patient with two retransplantations for graft non/dysfunction on pod 24; and disseminated aspergillosis due to Aspergillus fumigatus in a patient retransplanted for primary non-function (pod 19). All three patients underwent haemofiltration for renal failure. One patient with Candida albicans sepsis (pod 4) recovered under increased dosage of Ambisome® (3 mg kg - 1 per day). Ambisome® (1 mg kg - 1 per day) seems to be beneficial against systemic Candida infections. However, the onset of systemic Aspergillus infections could not be prevented. Obviously, higher Ambisome® doses appear to be necessary against Aspergillus. We recommend the use of Ambisome® (3 mg kg -1 per day) for patients with risk factors such as graft dys-/non-function, retransplantation, haemofiltration and complicated acute liver failure to prevent invasive aspergillosis.

Mixed allogeneic hematopoietic chimerism has previously been reliably achieved and shown to induce tolerance to fully MHC-mismatched allografts in mice and monkeys. However, the establishment of hematopoietic chimerism has been difficult to achieve in the discordant pig-to-primate xenogeneic model.To address this issue, two cynomolgus monkeys were conditioned by whole body irradiation (total dose 300 cGy) 6 and 5 days before the infusion of pig bone marrow (BM). Monkey anti-pig natural antibodies were immunoadsorbed by extracorporeal perfusion of monkey blood through a pig liver, immediately before the intravenous infusion of porcine BM (day 0). Cyclosporine was administered for 4 weeks and 15-deoxyspergualin for 2 weeks. One monkey received recombinant pig cytokines (stem cell factor and interleukin 3) for 2 weeks, whereas the other received only saline as a control.Both monkeys recovered from pancytopenia within 4 weeks of whole body irradiation. Anti-pig IgM and IgG antibodies were successfully depleted by the liver perfusion but returned to pretreatment levels within 12-14 days. Methylcellulose colony assays at days 180 and 300 revealed that about 2% of the myeloid progenitors in the BM of the cytokine-treated recipient were of pig origin, whereas no chimerism was detected in the BM of the untreated control monkey at similar times. The chimeric animal was less responsive by mixed lymphocyte reaction to pig-specific stimulators than the control monkey and significantly hyporesponsive when compared with a monkey that had rejected a porcine kidney transplant.To our knowledge, this is the first report of long-term survival of discordant xenogeneic BM in a primate recipient.

Recent studies in young (5-7 months) miniature swine have demonstrated that the thymus is involved in the rapid induction of stable tolerance to class I mismatched renal allografts after a 12-day course of Cyclosporine (CyA). Because both steroids and age are known to influence the structure and function of the thymus, we have now studied the effects of these two parameters on tolerance induction in this model.In young swine, the administration of methylprednisolone (MP) during the standard tolerance-inducing regimen (a 12-day course of CyA) produced severe renal dysfunction and acute cellular rejection histologically. However, the renal allografts recovered and were accepted for100 days with histological evidence of chronic rejection. To test the effect of age, two relatively old swine (55 and 71 months) received transplants of class I mismatched renal allografts and the standard 12-day course of CyA. One animal rejected the allograft acutely on postoperative day 22, and the second also rejected, but more slowly, with manifestations of chronic rejection.These findings suggest that both MP and old age interfere with the induction of stable tolerance in a fashion similar to the previously described effect of thymectomy. These results may have important implications for the mechanism of thymic-dependent tolerance, for the use of steroids in clinical protocols for the induction of allograft tolerance, and for the application of such protocols to adult patients.

The infiltration of the portal vein is not considered an absolute contraindication for resection therapy of proximal bile duct carcinomas. Portal vein resection and reconstruction may be performed without additional perioperative risk after hilar resection and hepatectomy. The resected hepatic vein is a suitable material for portal vein reconstruction. The median survival of patients with additional portal vein resection is comparable with patients without vascular infiltration in the same tumor stage.

Donor-specific tolerance to renal allografts in miniature swine is uniformly induced across a two-haplotype class I plus minor histocompatibility antigen disparity by a 12-day course of cyclosporine. Recent studies have demonstrated that the thymus is essential for rapid and stable tolerance induction, because either prior thymectomy or a series of thymic biopsies induce a spontaneously reversible rejection crisis after the 12-day course of cyclosporine. The present study examined the peripheral cellular mechanisms of tolerance by analyzing cytotoxic effector pathways in peripheral blood lymphocytes (PBL) of tolerant animals.The phenotype and cytotoxic T lymphocyte response of alloantigen-activated PBL cultures using cells from a series of tolerant animals with stable renal function (no thymic manipulation), or during a rejection crisis (induced by thymic biopsies), were studied. The in vitro findings were correlated with the in vivo clinical course of experimental animals.The data demonstrated that in vivo and in vitro tolerance was associated with a specific deficiency of interleukin-2 receptor (IL-2R) alpha-chain up-regulation on CD8 single-positive (SP) T cells expressing high levels of CD8 (CD8high) when PBL from tolerant animals are stimulated with donor class I alloantigen. Stimulation by third party class I alloantigen, or by donor antigen during a rejection crisis, produced efficient cytotoxic T lymphocyte responses and expression of IL-2Ralpha on CD8high SP cells.Antigen-specific regulation of the IL-2Ralpha expression on CD8high SP PBL is a principal event associated with and potentially involved in the mechanism of tolerance in this preclinical large animal model.

Die Pfortaderinfiltration stellt keine absolute Kontraindikation fur die Resektionsbehandlung von proximalen Gallengangstumoren dar. Pfortaderresektionen und -rekonstruktionen konnen ohne zusatzliches perioperatives Risiko nach Hilusre-sektion mit anatomischer Leberresektion durchgefuhrt werden. Die aus dem Leberresek-tat isolierte Vena hepatica ist ein geeigneter Gefasersatz fur die Pfortaderrekonstruktion. Patienten mit zusatzlicher Pfortaderresektion wegen Gefasinfiltration profitieren in unserem Patientenkollektiv, da hierdurch eine Resektionsbehandlung moglich wird und sich das mediane Uberleben gegenuber den Patienten gleicher Tumorstadien ohne Gefasresektion angleicht.

Einleitung: Gallenblasenkarzinome haben eine ungunstige Prognose. Eine 5-Jahres-Uberlebensrate ohne Therapie liegt bei unter 5%. Mehr als 50% der inzidentiellen Karzinome betreffen die Stadien I–II. Patienten und Methoden: 23 Patienten (14 w, 9 m), medianes Alter 60,4 (47–85) Jahre. Tl: 1, T2: 3, T3: 6 und T4: 13 Patienten. Die elektive Operation im Fruhstadium bestand aus einer erweiterten Cholezystektomie mit radikaler Lymphadenektomie. Ergebnisse und Schlusfolgerung: Die Uberlebensrate nach 6 Monaten war bei T2: 65%, T3: 80% und T4: 20%. Beim inzidentiellen Karzinom war die Prognose gunstiger, da unabhangig vom Tumorstadium die Uberlebenszeit uber 6 Monate lag. Im Fruhstadium ist eine radikale Operation nicht nur unter dem Gesichtspunkt der Radikalitat sondern auch der Palliation angezeigt.

Transfer of MHC class II genes, through allogeneic bone marrow (BM) transplantation, induced long-lasting acceptance of renal allografts in miniature swine. To adapt this approach to the clinic, we have now examined whether somatic transfer of allogeneic class II DR genes, into otherwise autologous bone marrow cells (BMC), can provide the matching required for inducing immune tolerance.Autologous BMC were transduced ex vivo with recombinant retroviruses for allogeneic DRB followed by BM transplantation. The recipients were then challenged with kidney allografts solely matched to the DRB transgene.Five miniature swine received autologous BMC conditioned with growth factors and transduced with recombinant retrovirus vectors containing allogeneic (n=4) or syngeneic (n=1) class II DRB genes and a drug-resistance marker. Expression of retrovirus-derived products in BM-derived cells was demonstrated by the detection of drug-resistant colony-forming progenitors and the presence of DRB retrovirus transcripts in peripheral cells. Analysis of selective mixed lymphocyte reaction responses to DR or DQ antigens indicated decreased reactivity toward the transduced DR gene product. Among all of the animals receiving fully mismatched kidney allografts, but with DRB matched to the transduced DRB, the one with the highest gene transduction rate showed stable allograft function and essentially normal renal histology for 2.5 years. A control animal, which received a syngeneic DRB gene, rejected its kidney allograft in 120 days after an earlier rejection crisis.These studies demonstrate that allogeneic MHC gene transfer into BM provides a new strategy for inducing tolerance across MHC barriers.

Long-term tolerance to kidney allografts across a two-haplotype class I disparity is uniformly induced in miniature swine with a short course of cyclosporine (CsA). In the absence of CsA, all recipients acutely reject kidney allografts within 2 weeks. Previous experiments have shown that graft-infiltrating mononuclear cells (GIC) migrate to the allograft in both CsA-treated and untreated animals. To evaluate the correlation between GIC phenotype and the clinical status, infiltrating cells were examined by flow cytometry, using selective gating to distinguish them from other renal cells. GIC from tolerant and rejector animals were mostly mature T cells, with 84% CD8+ cells, which consisted of 68% CD8+/CD4- and 16% CD8+/ CD4+ cells. This cellular phenotype was, however, markedly different from that of peripheral blood lymphocytes, suggesting a selective migration of cells into the graft. This selective process counterselected the CD3+/CD2- subset of GIC, which was never found in the graft. The distribution of GIC subsets was initially comparable in tolerated and rejected kidneys, but the CD4 single-positive subset then increased specifically in the allograft destined to rejection. The absence of CD4 single-positive cells in tolerated grafts was unlikely to be due to a direct effect of the CsA, because long-term tolerant animals, which received a second kidney without further immunosuppression, also showed no increase in CD4 single-positive cells. The fact that CD4 single-positive cells appeared only within the rejected kidneys, strongly suggests that this cell subset may be important in mediating immune rejection and supports the hypothesis that the development of tolerance in this model depends on a relative deficit of T-cell help.

We have previously demonstrated that tolerance to two-haplotype class I-mismatched renal allografts can be induced uniformly by a short course of cyclosporine. We report here that following transplant nephrectomy, 8 such long-term acceptor animals all accepted a second renal transplant MHC matched to the original donor without additional immunosuppression. These results indicate that the mechanism of tolerance to primarily vascularized renal allografts involves modification of the host's immune system by the first transplant. To assess the possibility that "graft adaptation" is also involved in the maintenance of tolerance, we retransplanted class I-disparate kidneys from tolerant animals into naive recipients MHC matched to the original recipient. Three of 4 such transplants were rejected acutely, while one animal demonstrated a markedly prolonged survival, but also eventually rejected. These results, therefore, demonstrate that: (1) graft adaptation is not required in order to maintain tolerance; (2) graft acceptance involves induction of systemic tolerance; and (3) graft adaptation may participate in kidney graft prolongation but is not sufficient to transfer tolerance to a secondary host.

Due to posterior location and the close relationship to vascular and biliary structures, resection of tumors within the caudate lobe of the liver may be a surgical challenge as well as an oncological hazard. Various approaches and techniques of isolated tumorectomy and combined liver resections are available and must be tailored to the individual situation. Prerequisite for a low operative risk is control of bleeding which can be achieved by sequential inflow and outflow occlusion of the liver.

Xenotransplantationen konnten eine Losung fur das Misverhaltnis zwischen Organangebot und Anzahl der notwendigen Transplantationen darstellen. Deshalb untersuchten wir die Moglichkeit ein klinikrelevantes Modell fur die Xenotrans-plantation vom Miniaturschwein zum nicht humanen Primaten zu entwickeln.

Due to posterior location and the close relationship to vascular and biliary structures, resection of tumors within the caudate lobe of the liver may be a surgical challenge as well as an oncological hazard. Various approaches and techniques of isolated tumorectomy and combined liver resections are available and must be tailored to the individual situation. Prerequisite for a low operative risk is control of bleeding which can be achieved by sequential inflow and outflow occlusion of the liver.