Endothelin antagonist treatment for successful liver transplantation from non-heart-beating donors.

BACKGROUND: With the shortage of cadaveric donors, non-heart-beating donors (NHBDs) are a potential source of liver allografts. However, warm ischemic injury in NHBDs seriously affects the viability of graft liver. Endothelin (ET)-1 has been reported to be involved in the hepatic microcirculatory disturbances after ischemia-reperfusion. METHODS: In a porcine orthotopic liver transplantation model, changes in the serum and liver tissue ET-1 concentration were measured and the effects of an ET receptor antagonist, TAK-044, were evaluated. After cardiac arrest of the donors, liver allografts were subjected to 90 min of warm ischemia, flushed, and preserved for 4 hr at 4 degrees C. The pigs were divided into two groups: a control group (no drug treatment) and a drug-treated group, in which donors and recipients were treated with TAK-044 (10 mg/kg body, drip intravenous injection). Both groups had six donor/recipient pairs. RESULTS: -The ET-1 concentration in the hepatic venous blood increased after reperfusion of the graft in the control group recipients. ET-1 in the graft liver significantly increased during the cold preservation period. TAK-044 treatment significantly increased recipient 7-day survival rate. After reperfusion of the graft, the concentrations of serum liver enzymes and arterial lactate in the drug-treated group were significantly lower than in the control group. The postoperative increase in portal venous pressure was significantly reduced in the drug-treated group. Measurements of liver enzymes in the washed-out preservation fluid at the time of graft rinsing indicated that TAK-044 treatment of the donors significantly suppressed liver enzyme release during ischemia. CONCLUSIONS: These findings indicate TAK-044 treatment has protective effects on postoperative function of hepatic allografts procured from NHBDs.

Transition and improvement in surgical treatment for rectal cancer during the last 21 years in our department.

The subject of this study was to examine the net effect of numerous changes in basic strategies, personnel and devices, upon the clinical courses and outcomes of rectal cancer patients. A total of 151 rectal cancer patients who underwent low anterior resection were divided into 4 groups (period 1 to 4) based upon the time period of the operation. They were compared among groups based upon the following parameters: blood loss, operation time, incidence of leakage and urinary dysfunction, incidence of ileus, duration of naso-gastric tube insertion, timing of initial oral feeding and survival. The blood loss during the operations, urinary dysfunction and duration of naso-gastric tube insertion tended to decrease in every period. Timing of initial oral feeding became faster. The operation times, incidence of leakage and ileus were nearly the same in each period. The 5-year survival rates on Dukes' C cases were 100% in period 4, 82.4% in period 3 and 50% in period 2. Survival rates became better. Our net outcome for rectal cancer treatment was satisfactory, because the survival rates became better under function preserving strategies.

Treatment of advanced colorectal adenocarcinoma with weekly high-dose l-leucovorin and 5-fluorouracil.

We report the results of 5-fluorouracil (5-FU) combined with high-dose l-folinic acid (leucovorin) therapy for patients with advanced colorectal carcinoma. In each treatment course, the patients weekly received both 5-FU (600 mg/m2 by intravenous 15 min infusion) and l-folinic acid (250 mg/m2 by intravenous infusion over a period of 2 h). A total of six treatments were administered with a 14-day interval to the next course of six treatments. Forty-eight patients were evaluated for toxicity and 32 for response. The combined complete and partial response rate was 25% in 32 patients. Toxicity was within acceptable limits without grade 4 toxicity. Although the response rate was slightly lower than those reported in phase II trials in Japan, the result was satisfactory. This therapy can be the standard chemotherapy for colorectal cancer patients, even in Japan.

Mechanism of NKT cell activation by intranasal coadministration of alpha-galactosylceramide, which can induce cross-protection against influenza viruses.

In a nasal vaccine against influenza, the activation of natural killer T (NKT) cells by intranasal coadministration of alpha-galactosylceramide (alpha-GalCer) can potently enhance protective immune responses. The results of this study show that the NKT cell-activated nasal vaccine can induce an effective cross-protection against different strains of influenza virus, including H5 type. To analyze the mechanism of NKT cell activation by this nasal vaccine, we prepared fluorescence-labeled alpha-GalCer by which we detect a direct interaction between NKT cells and alpha-GalCer-stored dendritic cells in nasal mucosa-associated tissues. Accordingly, although very few NKT cells exist at mucosa, the nasal vaccination induced a localized increase in NKT cell population, which is partly dependent on CXCL16/CXCR6. Furthermore, we found that NKT cell activation stimulates mucosal IgA production by a mechanism that is dependent on interleukin (IL)-4 production. These results strengthen the basis of nasal vaccination via NKT cell activation, which can induce immune cross-protection.

Mechanism of NKT cell-mediated transplant tolerance.

The mechanism by which CD1d-restricted Valpha14 natural killer T (NKT) cells participate in transplant tolerance has yet to be completely clarified. Recently, we showed that repeated activation of NKT cells by their specific glycolipid ligand, alpha-galactosylceramide, leads to a change in function to an immune regulatory role with IL-10 production. Moreover, these cells were shown to be able to induce regulatory dendritic cells (DCs). In this study, we showed that NKT cells from transplant tolerant recipients of cardiac allograft produced higher levels of IL-10, which is required for the maintenance of tolerance; this was proved by adoptive transfer experiments. In addition, DCs from wild-type (WT) tolerant recipients but not NKT cell-deficient recipients showed a higher IL-10-producing profile, a more immature phenotype, and tolerogenic capability. CD4 T cells from WT tolerant recipients but not NKT cell-deficient recipients also produced higher levels of IL-10 upon alloantigen stimulation and showed lower proliferative activity that was reversed by blocking the IL-10 receptor. These data indicate the existence of IL-10-dependent immune regulatory interplay among NKT cells, DCs, and CD4 T cells, even in the absence of artificial stimulation of NKT cells with synthetic glicolipids, which is required for the maintenance of transplant tolerance.

Increased intracranial pressure in a porcine model of fulminant hepatic failure using amatoxin and endotoxin.

BACKGROUND/AIMS: The purpose of this study was to develop a clinically relevant porcine model of fulminant hepatic failure (FHF) by means of administration of amatoxin and endotoxin. METHODS: Pigs were intraportally administered only saline in group 1 (n = 3), 1 microg/kg of lipopolysaccharide (LPS) in group 2 (n = 4), 0.1 mg/kg of alpha-amanitin in group 3 (n = 5), and amanitin plus LPS in group 4 (n = 9). RESULTS: All the pigs in groups 1 and 2 survived with minimal changes in liver function tests. In contrast to the 60% mortality in group 3, all the pigs in group 4 died within 96 h, with a significant increase in aspartate transaminase at 24 h (9,757 +/- 2,167 IU/I). In addition, they demonstrated severe metabolic disorders, such as serum lactate accumulation, hypoglycemia, coagulopathy, plasma amino acid imbalance, and hyperammonemia. The intracranial pressure significantly increased to 17.8 +/- 2.5 mmHg immediately before death. Reversal of FHF in these pigs following orthotopic liver transplantation confirmed that the toxicity is liver-specific and that the graft liver is unaffected. CONCLUSIONS: This porcine model of FHF induced by a combination of amanitin and LPS will be of much use in the development of new therapies for human FHF.

Requirement for natural killer T (NKT) cells in the induction of allograft tolerance.

In this study, we investigated the role of Valpha14 natural killer T (NKT) cells in transplant immunity. The ability to reject allografts was not significantly different between wild-type (WT) and Valpha14 NKT cell-deficient mice. However, in models in which tolerance was induced against cardiac allografts by blockade of lymphocyte function-associated antigen-1/intercellular adhesion molecule-1 or CD28/B7 interactions, long-term acceptance of the grafts was observed only in WT but not Valpha14 NKT cell-deficient mice. Adoptive transfer with Valpha14 NKT cells restored long-term acceptance of allografts in Valpha14 NKT cell-deficient mice. The critical role of Valpha14 NKT cells to mediate immunosuppression was also observed in vitro in mixed lymphocyte cultures in which lymphocyte function-associated antigen-1/intercellular adhesion molecule-1 or CD28/B7 interactions were blocked. Experiments using IL-4- or IFN-gamma-deficient mice suggested a critical contribution of IFN-gamma to the Valpha14 NKT cell-mediated allograft acceptance in vivo. These results indicate a critical contribution of Valpha14 NKT cells to the induction of allograft tolerance and provide a useful model to investigate the regulatory role of Valpha14 NKT cells in various immune responses.