Intragraft expression of p38 and activated p38 MAPK (mitogen-activated protein kinase) in rat small bowel transplantation.

Recent studies suggest that cytotoxic T-lymphocytes expressing p38 mitogen-activated protein kinase (p38MAP kinase) contribute to allograft rejection in clinical heart transplantation. Interleukin-2 (IL-2), a potent T cell mitogen, activates the p38MAP kinase pathway, resulting in phosphorylation of target transcription factors. In this study we investigated the expression of activated p38MAP kinase in intragraft cell infiltrates following rat heterotopic small bowel transplantation and examined the effects of the immunosuppressant FK506 on intragraft expression of activated p38MAP kinase and allograft rejection. Allografts receiving FK506 (0.5 mg/kg per day i. m.) for 7 days as primary anti-rejection therapy had a significant reduction in histopathological evidence of allograft rejection on Day 7, compared to allograft controls. In addition, Western blotting analysis of intragraft cell infiltrates showed a reduction in the expression of activated p38MAP kinase in allografts treated with FK506. We conclude that intragraft cell infiltrate expression of activated p38MAP kinase is an important marker of acute rejection in this animal model of small bowel transplantation, and that FK506 is an effective immunosuppressant, in this situation, that may act in part by preventing the activation of p38MAP kinase.

Repeat liver resection for hepatocellular carcinoma.

BACKGROUND: Although hepatectomy has been accepted as a therapeutic option for the primary tumor of hepatocellular carcinoma (HCC), what role the second liver resection will play in the clinical care of patients with intrahepatic recurrence of HCC after the initial resection has not been well evaluated. STUDY DESIGN: In a retrospective review of the 6-year period between January 1991 and December 1996, records were examined of 94 patients who underwent curative liver resection for HCC. Of these, 57 patients had isolated recurrent disease to the liver; 12 of the 57 patients underwent repeat surgical resection and 45 patients received nonsurgical ablative therapy. Clinical data for these patients were reviewed for operative morbidity and mortality, survival, disease-free survival, and pattern of failure. RESULTS: There were no perioperative deaths during repeat liver resections for recurrent HCC. Operative morbidity in the second resection was comparable to the initial resection. The disease-free survival rate after the second hepatectomy was 31% at 2 years, significantly lower than that after initial hepatectomy (62%) (p = 0.009). The overall survival rate after the second hepatectomy was 90% at 2 years, in contrast to 70% after nonsurgical ablative treatment for recurrent HCC (p = 0.253). CONCLUSIONS: Although the second liver resection for recurrent HCC can be performed safely and may improve survival, the disease-free survival rate after such resection therapy is low. This likelihood of further recurrences encourages studies for the selection of patients who may benefit from repeat liver resection.

Clinical predictors of recurrence site after hepatectomy for metastatic colorectal cancer.

BACKGROUND/AIMS: Surgical resection of hepatic colorectal metastasis may produce long-term survival and cure; however, a significant proportion of patients will have intrahepatic and/or extrahepatic recurrence with a poor prognosis. The aim of this study was to define clinical predictors of recurrence site after hepatectomy in terms of stratifying patients for adequate adjuvant trials to improve the prognosis. METHODOLOGY: Clinical, pathologic, and outcome data for 70 consecutive patients undergoing hepatectomy for colorectal metastasis isolated to the liver were reviewed retrospectively, and all data were analyzed by the logistic multivariate regression model. RESULTS: Recurrence in the remnant liver was seen in 60% of patients, and recurrence in the lung was found in 34% of patients. Number of liver tumors was the only significant and independent predictor of recurrence in the remnant liver (P = 0.048). All patients with three or more tumors experienced recurrence. Location of liver tumors lying adjacent to the hepatic vein, which was confirmed by preoperative imaging techniques, was the only significant and independent predictor of recurrence in the lung (P = 0.020). CONCLUSIONS: Number and location of liver tumors would be the significant and independent clinical predictors of recurrence site after hepatectomy for metastatic colorectal cancer. This might be useful for justification and selection of effective adjuvant trials after surgery.

Humoral human xenoreactivity against isolated pig pancreatic islets.

It is widely believed that the hyperacute rejection of vascularized xenografts in the pig-to-human combination is triggered by the binding of human preformed natural antibodies (PNAbs) to the Galalpha.(1,3)Gal epitope in pig endothelium and the subsequent activation of complement. However, it remains poorly defined whether xenogeneic pig pancreatic islets are damaged by antibody and complement-mediated mechanisms. We examined the expression of Galalpha(1,3)Gal on isolated adult pig islets and the presence of PNAbs in normal human sera directed against islets, using immunofluorescence staining and confocal laser scanning microscopy. The pig islets were not stained with Galalpha(1,3)Gal-specific lectin GSIB4, however, the exocrine cells reacted strongly with GSIB4, indicating that the Galalpha(1,3)Gal epitope was highly expressed on exocrine cells, but not on islets. Human sera showed weak reactivity of IgM and IgG class PNAbs to the islets, but strong reactivity to the exocrine cells. Furthermore, we investigated the cytotoxic effect of human serum on pig islets using an in vitro model of pig-to-human islet transplantation. The incubation of pig islets with normal human sera for 45 min resulted in less than 10% specific lysis despite the binding of PNAbs, whereas exposure of porcine aortic endothelial cells to the same human sera caused 56% complement-mediated lysis, determined using a MTT cytotoxic assay. These results support the view that pig islets might not undergo early antibody and complement-mediated rejection in humans.

The impact of interferon gamma receptor expression on the mechanism of escape from host immune surveillance in hepatocellular carcinoma.

Interferon gamma (IFN-gamma) plays an important role in host defense mechanism and participates in the progression of chronic liver disease. IFN-gamma exerts its pleiotrophic effects by transcriptional regulation of expression of numerous genes, such as major histocompatibility complex (MHC) class I and Fas, through interaction with IFN-gamma receptor (IFN-gamma-R). Although hepatocytes in normal liver express weak or no IFN-gamma-R, those in acute and chronic liver disease up-regulate its expression. A study using IFN-gamma-R alpha-chain knock-out mice revealed the actions of IFN-gamma on tumor cells as an extrinsic tumor-suppressor mechanism. However, it is unclear whether or how hepatocellular carcinoma (HCC) blocks the signal transduction of IFN-gamma to evade host immune surveillance. We examined the expression of IFN-gamma-R and IFN-gamma-inducible genes in 44 cases with HCC using real-time reverse-transcriptase polymerase chain reaction (RT-PCR) and immunohistochemistry. In noncancerous liver tissues (n = 38), IFN-gamma-R expression on the cell surface was up-regulated in 27 cases. In IFN-gamma-R-negative cases (n = 15), tumor size was larger (P =.032), serum alpha-fetoprotein (AFP) level was higher (P =.001), intrahepatic and extrahepatic metastasis was more common (P =.044 and.013, respectively), and Ki-67 labeling index (LI) was higher (P =.041), compared with IFN-gamma-R-positive cases. Accordingly, the evasion mechanism may play an important role in progression, especially metastasis, in HCC. The significant correlation between the status of IFN-gamma-R and the expression of Fas and MHC implies that the loss of IFN-gamma-R might contribute to the mechanism of escape from host immune rejection in HCC.

The alteration of Fas receptor and ligand system in hepatocellular carcinomas: how do hepatoma cells escape from the host immune surveillance in vivo?

Escape from the immune surveillance may play an important role in tumor outgrowth and metastasis. Alteration of the Fas receptor (Fas)/ligand (FasL) system including soluble forms is regarded as one of the mechanisms preventing the immune system from rejecting the tumor cells. However, less attention has been paid to the role of Fas/FasL interaction in vivo. Therefore, we investigated the expression of Fas and FasL by immunohistochemistry and reverse-transcription polymerase chain reaction (RT-PCR) and measured the serum levels of soluble Fas (sFas) and FasL (sFasL) in 44 patients with hepatocellular carcinoma (HCC). In the noncancerous liver tissues, Fas expression was up-regulated in most cases, and FasL expression was detected in 6 cases. In Fas-positive HCC cases (n = 15), the intrahepatic metastatic foci was less (P =.037), apoptosis of tumor cells was more (P =.004), the disease-free survival rate was higher (P =.004), and p53-positive cases were less (P =.003), compared with Fas-negative cases. The sFas and sFasL levels in HCC patients were significantly higher and lower than those in controls, respectively. RT-PCR and immunohistochemistry revealed generation of sFas in the hepatocytes and tumor-infiltrating mononuclear cells rather than in hepatoma cells. Accordingly, hepatoma cells may eliminate Fas expression on themselves and let the hepatocytes and infiltrating mononuclear cells generate sFas to escape from the immune system and to produce metastasis. FasL might contribute to malignant transformation in some circumstances, because hepatocytes in the pericancerous pseudolobules expressed FasL.

The serum interleukin 8 level reflects hepatic mitochondrial redox state in hyperthermochemohypoxic isolated liver perfusion with use of a venovenous bypass.

BACKGROUND: We have recently developed a simple method of hyperthermochemohypoxic isolated liver perfusion (HILP) as a regional therapy for unrecognized liver micrometastases. However, little is known about the influence of HILP on cytokine production and liver function. We investigated the influence of HILP on interleukin 8 (IL-8) production and the hepatic mitochondrial function and assessed the relationship between these 2 parameters. We also measured the serum tumor necrosis factor-alpha (TNF-alpha) and interleukin 1 beta (IL-1 beta) levels to examine the involvement of HILP-induced cytokines in the tumor response. METHODS: Sixteen patients with metastatic liver tumors were randomly assigned to undergo hepatectomy with HILP (group A, n = 9) or hepatectomy alone (group B, n = 7). The isolated liver was perfused for 30 minutes with Ringer's lactate solution containing chemotherapeutic agents warmed to 42 degrees C to 43 degrees C without oxygenation. RESULTS: The serum IL-8 levels in group A were markedly increased, with peaks at 3 hours after reperfusion, which was significantly higher than levels in group B (P < .01). In group A the arterial ketone body ratio, which reflects the hepatic mitochondrial redox state, decreased during perfusion and was gradually restored to the preperfusion level 1 hour after reperfusion. However, in group B it decreased during hepatectomy but rapidly recovered 5 minutes after hepatectomy. There was a significant negative correlation between the peak serum IL-8 level and the initial velocity of arterial ketone body ratio recovery for the first 5 minutes after reperfusion r = -0.83, P < .001). The serum TNF-alpha and IL-1 beta were temporarily detected only in 3 of 9 patients in group A. CONCLUSIONS: We have shown that HILP resulted in augmented IL-8 release but not TNF-alpha and IL-1 beta and that the serum IL-8 level reflects the hepatic mitochondrial redox state. These findings suggest that IL-8 production may be associated with hepatic mitochondrial impairment during ischemia. This work may contribute to new therapeutic strategies not only for hepatic ischemia reperfusion injury but also for metastatic liver tumors.

Comparison of hemodynamic changes in two veno-venous bypass techniques modified at the portal cannulation site.

Veno-venous bypass under total vascular exclusion is a useful technique to permit safer resection of hepatic malignancy. We describe here a retrospective study of two modified venous bypass techniques as alternatives to the conventional end-on portal cannulation technique. Portal decompression via inferior mesenteric vein access was performed in eight patients (group A), and portal decompression via a passive shunt between a branch of the mesenteric vein and the right saphenous vein was performed in a second group (group B; n = 8). Both techniques were used in hepatic resection for malignancy under total vascular exclusion. To assess the efficacy of these bypass techniques, we compared the hemodynamic changes in the two groups. There were no differences in the bypass flow between the two groups. Neither group showed any significant changes in hemodynamic parameters (including mean arterial pressure, cardiac index, systemic vascular resistance index, and pulmonary artery pressure) between the pre-bypass and bypass phases. The heart rate in the bypass phase was significantly increased compared to that in the pre-bypass phase in both groups. All hemodynamic parameters in each phase were similar in the two groups. We conclude that both techniques maintained adequate venous return and stabilized the hemodynamic changes during hepatic resection under total vascular exclusion, and that either technique can be selected according to the intraoperative situation.

Predominant role of local immunosuppressive effect in enhanced efficacy of liposomal FK506 in organ transplantation.

Liposomal FK506 is a new formulation of FK506 that increases FK506 levels in the liver and decreases them in the kidney in comparison to conventional IV formulation. In the present study, the efficacy of liposomal FK506 was evaluated in canine kidney and liver transplantation models. Liposomal FK506 increased the immunosuppressive efficacy of FK506 in the liver transplantation model, but decreased it in the kidney transplantation model. These results suggest that local immunosuppressive effects with increased intragraft FK506 level would play an important role in enhancing the immunosuppressive efficacy of liposomal FK506 in liver transplantation.

Transthoracic transdiaphragmatic approach for hepatectomy of Couinaud's segments VII and VIII.

For hepatectomy of Couinaud's segment VII or VIII, severe compression and mobilization of the liver is required to establish the operative field via the usual transabdominal approach. Compression of the cirrhotic liver impairs hepatic and systemic blood circulation, which may cause liver dysfunction. We adopted a transthoracic transdiaphragmatic approach for hepatectomy of segment VII or VIII in cirrhotic patients to establish a good operative field without compressing the liver. The aim of this study was to evaluate the benefits of this approach. Forty-four patients with hepatocellular carcinoma (HCC) complicating liver cirrhosis who underwent limited hepatectomy of Couinaud's segment VII or VIII were studied. The patients were randomized to two groups preoperatively: group I (n = 22), transabdominal approach; group II (n = 22), transthoracic transdiaphragmatic approach. There were no differences in preoperative liver function tests, hepatic functional reserve, or extent of tumor between the two groups. The operative time in group II was significantly shorter than that in group I (243 +/- 50 versus 313 +/- 80 minutes;p < 0.01). Operative blood loss in group II was also significantly smaller than that in group I (1190 +/- 1098 versus 2679 +/- 2267 g;p < 0.01). Serum lactate dehydrogenase levels on postoperative day 1 in group II were significantly lower than those in group I (587 +/- 154 versus 791 +/- 383 IU/L;p < 0.05). Major postoperative complications were significantly fewer in group II. It was concluded that the transthoracic transdiaphragmatic approach is a useful method for hepatectomy of segments VII and VIII in cirrhotic patients.

Significant influence of accompanying chronic hepatitis status on recurrence of hepatocellular carcinoma after hepatectomy. Result of multivariate analysis.

OBJECTIVE: The aim of this study was to evaluate the correlation between the histologic status of accompanying chronic hepatitis and the recurrence rate of hepatocellular carcinoma (HCC) after hepatectomy by multivariate analysis. SUMMARY BACKGROUND DATA: Recent studies have suggested that a considerable number of intrahepatic recurrence of HCC after hepatectomy might be the results of metachronous multicentric hepatocarcinogenesis. The authors hypothesized that the incidence of recurrence due to metachronous multicentric hepatocarcinogenesis would depend on the histologic status of accompanying chronic viral liver disease, which is a main promoter of HCC. METHODS: One hundred ten patients with HCC who underwent curative resection were studied. Histologic status of accompanying chronic hepatitis was classified into the three categories: 1) normal liver or chronic persistent hepatitis (CPH, n = 13), 2) chronic aggressive hepatitis (CAH, n = 50), and 3) liver cirrhosis (LC, n = 47). RESULTS: The Cox multivariate proportional hazard model showed that the accompanying chronic viral hepatitis status (p = 0.0133), extent of hepatectomy (p = 0.0078), and number of tumors (p = 0.0475) were significantly predictive variables for recurrence-free survival. By the log-rank test, recurrence-free survival rate in patients with CPH was significantly higher than those in patients with CAH (p = 0.0005) and LC (p = 0.0075). Patients with CAH had the lowest recurrence-free survival rate (vs. LC, p = 0.028). CONCLUSIONS: The results of this study indicated the significant influence of histologic activity of hepatitis on recurrence of HCC. This might support the concept of significant contribution of multicentric hepatocarcinogenesis to recurrence of HCC after hepatectomy.

Influence of associated viral hepatitis status on recurrence of hepatocellular carcinoma after hepatectomy.

The purpose of this study was to investigate the relation between the recurrence of hepatocellular carcinoma (HCC) and the histologic status of underlying chronic liver disease from a viewpoint of multicentric hepatocarcinogenesis. Sixty-eight patients who underwent curative resection of HCC and have been followed for more than 2 years are reported. Based on the microscopic findings of the noncancerous part of the liver, the patients were divided into normal liver (N,n = 2), chronic persistent hepatitis (CPH,n = 6), chronic aggressive hepatitis (CAH,n = 31), and liver cirrhosis (LC,n = 29) according to a classification by the European Association for the Study of the Liver. Background data for the groups showed no significant differences. Recurrence was observed in none of the patients in the N and CPH groups, 26 (83.9%) of the patients in the CAH group, and 12 (41.4%) of the patients in the LC group. The cumulative disease-free survival rate of the CAH group was significantly lower than that of the CPH group (p < 0.05) and LC group (p < 0.01). This study revealed that the histologic status of the underlying chronic liver disease influenced the recurrence rate in patients with HCC. CAH was considered to be a risk factor for recurrence after resection of HCC.

Effect of complement activation in human serum on isolated porcine islets.

We investigated the effect of the activation of complement in human serum on isolated adult porcine islets using an in vitro model of pig-to-human islet transplantation. Pancreata were obtained from slaughterhouse pigs (6-8 mo old). Islets were prepared by intraductal collagenase digestion followed by purification on Ficoll gradients. The purified islets were incubated with xenogeneic human serum with or without heat inactivation for 45 min. As control, islets were incubated with autologous porcine serum. After the incubation, the islets' responsiveness to an acute glucose stimulus (5.5 mM, static incubation) was evaluated by measurement of the insulin content of the medium. Islets exposed to human serum showed significantly lower insulin secretory response than the control (1.76 +/- 1.17 microU/islet/120 min, without heat inactivation; 1.74 +/- 1.36 microU/islet/120 min, with heat inactivation; 3.39 +/- 0.92 microU/islet/120 min, control). No difference in insulin secretory response, however, was observed between islets exposed to human serum with heat inactivation and without. Furthermore, we evaluated the cytotoxic activity of human serum on porcine islets by a complement-dependent cytotoxicity using the MTT colorimetric assay, and found that the human serum had no complement-dependent cytotoxic activity against the islets. We concluded that the insulin secretion dysfunction of porcine islets exposed to human serum was not due to the activation of complement and there was no evidence of hyperacute rejection mediated by complement activation in the in vitro model of pig-to-human islet transplantation.

Liver transplantation for hepatocellular carcinoma: consideration from the findings on autopsy.

Extrahepatic spread of hepatocellular carcinoma was investigated in twenty autopsy cases with unresected hepatocellular carcinoma to define the appropriate patient selection criteria for liver transplantation. Diagnosis of extrahepatic spread of cancer by diagnostic imaging was not easy, and unsatisfactory prognosis after liver transplantation in patients with hepatocellular carcinoma might have been attributed to the high incidence of extrahepatic occult foci of cancer. All patients with multiple nodular, massive and diffuse tumor had extrahepatic spread of cancer. Only patients with a single nodular type tumor, no larger than 30 mm in diameter, had no extrahepatic metastasis, and these patients are the preferred candidates for liver transplantation.

Different immunosuppressive effects of liposomal FK506 in liver and kidney transplantation.

The efficacy of liposomal FK506 was compared between a canine liver transplantation model and a canine kidney transplantation model. The present study revealed that liposomal FK506 increased immunosuppressive efficacy of FK506 in liver transplantation but decreased in kidney transplantation. Because liposomal FK506 increased FK506 levels in the liver and spleen, and decreased FK506 levels in the kidney, it was suggested that enhanced immunosuppressive efficacy in liver transplantation should be attributed to the local immunosuppressive effects in the hepatic allograft rather than effective suppression of splenocyte activity.