Yasushi Harihara

Living-related transplantation of left liver plus caudate lobe

Living-related liver transplantation (LRLT) has been accepted as an effective treatment of choice for pediatric patients but its feasibility for adult patients is limited because of graft size disparity. Kawasaki and colleagues have shown that the donor’s left liver (without the caudate lobe) can be used as a maximal-for-size graft to adults if the ratio of the predicted graft volume (GV) to the recipient’s standard liver volume (SV) is more than one-third. When the graft is too small, auxiliary implantation of the left liver or use of the right liver can be an option in patients under urgent situations. Recently Miyagawa and colleagues reported a patient who received a left liver with caudate lobe graft, but they did not reconstruct the drainage vein of the caudate lobe, which may cause lobe congestion and dysfunction. We report a new technique by which the left liver plus caudate lobe is implanted with complete reconstruction of the vessels relevant to the caudate lobe.

A comparison of gene expression in murine cardiac allografts and isografts by means DNA microarray analysis.

BACKGROUND Acute rejection of allografts remains a significant problem in clinical transplantation, and the fundamental mechanism underlying this rejection are as yet only poorly elucidated. Recently, DNA microarrays have come into use for the study of gene expression profiles, and we have taken advantage of this new technology to investigate acute rejection. We compared mRNA profiles in murine cardiac allografts with isografts using DNA microarrays with probe sets corresponding to more than 11,000 mice genes. METHODS We screened for gene expression changes in murine cardiac allografts between fully incompatible mice strains (BALB/c H2d to C3H/He H2k) using a DNA microarray. The heart was heterotopically transplanted. Allografts (BALB/c to C3H/He) were removed on days 1, 3, and 5. As a control, isografts (C3H/He to C3H/He) harvested on days 1, 3, and 5 and native hearts of both strain mice (C3H/He and BALB/c) were obtained. RESULTS On day 5, interferon-gamma (IFN-gamma) and many IFN-gamma-inducible genes were profoundly induced in the allograft relative to isograft. Monokine induced by IFN-gamma was most profoundly induced followed by inducibly expressed GTPase and Lmp-2. IFN-gamma was also profoundly induced. The induction was detectable from day 3. In contrast, genes regulated by other cytokines exhibited only modest changes. CONCLUSION IFN-gamma-inducible genes are specifically up-regulated in murine cardiac allografts, suggesting that signaling mediated by IFN-gamma may play an important role in the late phase of acute rejection in vivo.

Objective evaluation of Liver consistency to estimate hepatic fibrosis and functional reserve for hepatectomy

BACKGROUND The empiric evaluation of liver consistency is currently used to plan the surgical strategy. The aim of this study was to verify the feasibility of the objective measurement of liver consistency and to check its correlation with liver fibrosis and liver functional reserve. STUDY DESIGN Fifty-two consecutive patients who underwent hepatic resections in our department were enrolled. The indications for liver resection were hepatocellular carcinoma in 36 patients, metastatic liver tumors in 12 patients, and other conditions in 4 patients. Liver consistency was measured with a new tactile sensor. A fibrosis index was calculated as an expression of the percentage of fibrotic tissue. Liver consistency was compared with the degree of liver fibrosis observed in histologic specimens (fibrosis index) and with liver function parameters. RESULTS Liver stiffness showed a significant positive correlation with fibrosis index (r = 0.887, p < 0.0001). Liver stiffness also showed significant positive correlation with the indocyanine green test (r = 0.631, p < 0.0001) by a univariate analysis. The indocyanine green test and platelet count were independently and significantly associated with liver stiffness by a multiple regression analysis. In five patients, the liver stiffness values measured intraoperatively differed markedly from those expected from the indocyanine green test values. In these patients, the operative procedures were finally selected based on the liver stiffness measured with the tactile sensor and good clinical outcomes were obtained. CONCLUSIONS These results show for the first time that liver stiffness can be clinically assessed quantitatively by means of the tactile sensor. The tactile sensor adequately estimates liver stiffness and this estimation is well correlated with liver fibrosis and functional reserve. Liver consistency determined objectively in this manner may be useful for optimizing surgical decision making.

Prolonged survival in rat liver transplantation with mouse monoclonal antibody against an inducible costimulator (ICOS).

Background. An inducible costimulator (ICOS), a recently identified costimulatory receptor with a close structural homology to CD28 and CTLA4, is expressed on activated T cells. Interaction with its ligand on antigen-presenting cells stimulates T-cell proliferation to produce a different spectrum of cytokine. The inhibition of ICOS-mediated signal transduction by an anti-ICOS antibody is considered to be capable of protecting against graft rejection in organ transplantation. Methods. An anti-rat ICOS antibody was intravenously administered into recipients of dark Agouti-to-Lewis liver transplantations. The recipient lymphocytes from mesenteric lymph nodes were harvested on day 7 after transplantation for fluorescence-activated cell sorting analysis, and tissue specimens from the grafts were removed for histologic evaluation. Antigen-specific T-cell proliferation responses were assessed in vitro with anti-ICOS antibody. Results. Monotherapy with the antibody significantly prolonged the graft survival time by inhibiting T-cell activation and its proliferation response. The graft-infiltrating cells, both CD4 and CD8 T cells, were not completely reduced even when rats were administered the antibody, whereas the expression of ICOS almost completely disappeared in these cells. Conclusions. T-cell activation through the ICOS costimulatory pathway plays an important role in graft rejection, and manipulating its pathway is an effective method for modulating transplantation immunity.

Reconstruction of the hepatic and portal veins using a patch graft from the right ovarian vein.

We describe a patch-graft technique using the right ovarian vein for reconstruction of the right hepatic and portal veins after resection in hepatectomy and pancreatoduodenectomy in female patients. After partial resection of the right hepatic vein or portal vein for removing either hepatic or pancreatic tumors, the defects were covered by a patch graft from the right ovarian vein. The proximal part of the vein, 5 cm in length, was harvested, divided longitudinally, and then divided into two equal parts, which were sutured together to give a patch measuring 2.5 x 2.0 cm. This technique can be applied for reconstruction after partial resection of the hepatic or portal vein in hepatectomy and pancreatoduodenectomy.

A new technical aspect of ultrasound-guided liver surgery

Nowadays, resective hepatic surgery should be considered an echo-guided surgical procedure to guarantee that effective anatomical resection is accomplished. We describe a simple and original technique guided by intraoperative ultrasonography (IOUS), called the hooking technique, that enables the ligation sites of the intrahepatic vessels during systematic segmentectomy to be chosen precisely. Together with other IOUS-guided techniques described previously, the hooking technique provides a further guarantee for the successful execution of anatomical and radical liver resection.

Simultaneous blockade of co-stimulatory signals, CD28 and ICOS, induced a stable tolerance in rat heart transplantation

An inducible co-stimulator (ICOS), a recently identified co-stimulatory receptor with a close structural homology of CD28 and CTLA4, is expressed on activated T cells. Anti-ICOS antibody was demonstrated to be effective on prolongation of graft survival after liver transplantation in rats. In this study, we investigated the potency of tolerance induction using the antibody combined with a recombinant adenovirus vector containing CTLA-4Ig cDNA (AdCTLA-4Ig) in rat heart transplantation model. Using a DA-to-Lewis rat heart transplantation model, an anti-rat ICOS antibody and AdCTLA-4Ig were simultaneously administered i.v. into recipients. The tissue specimens from the grafts were removed on various days after transplantation for histological evaluation. Donor-strain skin and heart grafts, and third-party heart allografts were challenged in the recipients with a long-term surviving graft. Splenocytes from the tolerance-induced recipients were used for adoptive transfer study. Anti-ICOS antibody alone did not prolong the survival of heart allograft. AdCTLA-4Ig monotherapy significantly prolonged the survival of heart allograft (Group 4). With a combination of Anti-ICOS antibody and AdCTLA-4Ig, all recipients were resulted in a long-term allograft acceptance for more than 200 days (Group 8). When challenged donor-strain skin grafts in the tolerant rats of Group 4, the skin was rejected, which also lead to a rejection of primary heart allografts. The recipients in Group 8 also rejected donor-strain skin grafts with no rejection of the primary heart grafts. These recipients accepted secondary heart grafts from donor-strain but not third-party. In Group 8 long-term survival recipients showed a high population of CD4+CD25+ regulatory T cell in peripheral blood, and in adoptive transfer study subtraction of these CD4+CD25+ T cells accelerate the rejection of heart graft in secondary irradiated recipients. The present results demonstrated that anti-ICOS antibody combined with AdCTLA-4Ig potently induces a stable immune tolerance after heart allografting in rat, which is mediated by the induction of CD4+CD25+ regulatory T cells. This strategy may be attractive for clinical employment to induce transplantation tolerance.

Improved Hepatic Regeneration With Reduced Injury by Redox Factor-1 in a Rat Small-Sized Liver Transplant Model

Redox factor‐1 (Ref‐1) has been shown to function in a redox‐dependent manner in the cell. This study was designed to examine the effects of Ref‐1 on liver regeneration as well as protection against postischemic injury in a rat model of 20% partial liver transplantation. Adenovirus carrying the full length of Ref‐1 gene was introduced into liver grafts by ex vivo perfusion via the portal vein during preservation. Liver graft weights were assessed, as well as graft histology, serum levels of alanine aminotransferase (ALT)/bilirubin, DNA binding activities of AP‐1 and Stat3. Redox factor‐1 successfully expressed in the liver graft, improved regeneration by promoting cell proliferation. Overexpression of Ref‐1 protein also reduced post‐transplant injury and inflammatory reactions in the grafts. The increased serum levels of ALT and bilirubin observed after transplantation were significantly reduced by Ref‐1 overexpression. Furthermore, adenovirally overexpressed Ref‐1 in mouse liver successfully promoted liver regeneration after simple partial hepatectomy. Interestingly, Ref‐1 significantly increased DNA binding of Stat3, but not AP‐1. Overexpressed Ref‐1 effectively promoted graft regeneration and reduced postischemic injury in a small‐sized liver transplantation model. The results of the present study may open a new avenue to clinical transplantation of disproportionately sized grafts in living‐related liver transplantation.

p53 and p21/Waf1 protein expression and K-ras codon 12 mutation in carcinoma of the papilla of Vater

OBJECTIVE:There have been few studies on the molecular biological characteristics of carcinoma of the papilla of Vater. In this study, p53 and p21/Waf1 expression and K-ras codon 12 mutation in carcinoma of the papilla of Vater were investigated.METHODS:Thirty-seven cases of carcinoma of the papilla of Vater were studied. Macroscopically, the carcinoma was ulcerative in 15 cases and nonulcerative in 22 cases. Histologically, nine were intestinal type, 27 were pancreaticobiliary type, and one was undifferentiated. Formalin-fixed, paraffin-embedded sections were immunohistochemically stained for p53 and p21. K-ras codon 12 mutation was detected with the two-step polymerase chain reaction-restriction fragment length polymorphism method, followed by direct sequencing.RESULTS:p53 overexpression was found in 17 of 37 cases (46%) and was more frequent in the ulcerative type than in the nonulcerative type (67%vs 32%, p < 0.05). p21/Waf1 protein expression was found in 15 of 37 cases (41%), and was not correlated with that of p53. K-ras codon 12 mutation was found in 14 of 37 cases (38%), and was more frequently detected in the intestinal type than in the pancreaticobiliary type (66%vs 30%, p < 0.05). On direct sequencing, the mutations were mainly GGT to GAT (9/14) and GGT to GTT (4/14). The type of mutation did not correlate with the histological type.CONCLUSIONS:In carcinoma of the papilla of Vater, p53 overexpression may play a role in tumor ulceration. p21/Waf1 expression is induced via a p53-independent pathway. Carcinomas of the intestinal and pancreaticobiliary types may develop via different mechanisms, and K-ras mutation is mainly associated with the intestinal type.

Simple test on the back table for justifying single hepatic-arterial reconstruction in living related liver transplantation.

1. Sollinger HW, Odorico JS, Knechtle SJ, D’Alessandro AM, Kalayoglu M, Pirsch JD. Experience with 500 simultaneous pancreas-kidney transplants. Ann Surg 1998; 228: 284. 2. Gruessner RW, Sutherland DE, Drangstveit MB, Wrenshall L, Humar AA, Gruessner AC. Mycophenolate mofetil in pancreas transplantation. Transplantation 1998; 66: 318. 3. Groth CG. The European experience with mycophenolate mofetil. European Mycophenolate Mofetil Cooperative Study Group. Transplant Proc 1996; 28: 30. 4. Vanrenterghem Y. The use of mycophenolate mofetil (CellCept) in renal transplantation. Nephron 1997; 76: 392 5. Wilmink T, Frick W. Drug-induced pancreatitis. Drug Saf 1996; 14: 406.