Yuichi Masuda

Oral activated charcoal adsorbent (AST-120) ameliorates chronic kidney disease-induced intestinal epithelial barrier disruption.

Background: Chronic kidney disease (CKD) impairs intestinal barrier function which by allowing influx of noxious products causes systemic inflammation. We have recently shown that intestinal barrier dysfunction in CKD is due to degradation of epithelial tight junction (TJ) which is, in part, mediated by influx of urea and its conversion to ammonia by microbial urease. We hypothesized that by adsorbing urea and urea-derived ammonia, oral activated charcoal (AST-120) may ameliorate CKD-induced intestinal epithelial barrier disruption and systemic inflammation. Methods: Rats were randomized to the CKD or control groups. The CKD group was fed a chow containing 0.7% adenine for 2 weeks. They were then randomized to receive a chow with or without AST-120 (4 g/kg/day) for 2 weeks. Rats consuming regular diet served as controls. Animals were then euthanized, colons were removed and processed for Western blot and immunohistology, and plasma was used to measure endotoxin and oxidative and inflammatory markers. Results: Compared with the controls, the untreated CKD rats showed elevated plasma endotoxin, IL-6, TNF-α, MCP-1, CINC-3, L-selectin, ICAM-1, and malondialdehyde, and depletions of colonic epithelial TJ proteins, claudin-1, occludin, and ZO1. Administration of AST-120 resulted in partial restoration of the epithelial TJ proteins and reduction in plasma endotoxin and markers of oxidative stress and inflammation. Conclusions: CKD animals exhibited depletion of the key protein constituents of the colonic epithelial TJ which was associated with systemic inflammation, oxidative stress and endotoxemia. Administration of AST-120 attenuated uremia-induced disruption of colonic epithelial TJ and the associated endotoxemia, oxidative stress and inflammation.

Prognosis of Adult Patients Transplanted with Liver Grafts < 35% of Their Standard Liver Volume

We have previously reported that a graft volume (GV) > 30% of the recipients standard liver volume (SLV) can meet the recipients metabolic demands. Here we report our experience with adult‐to‐adult living donor liver transplantation using left side grafts < 35% of the recipients SLV. Of 143 adult living donor liver transplants, 13 auxiliary partial orthotopic liver transplants, 8 right side grafts, and 2 retransplantation cases were excluded. The resulting 120 cases were divided into 2 groups: group S consisted of 33 patients who received liver grafts < 35% of their SLV, and group L consisted of 87 patients who received liver grafts ≥ 35% of their SLV. Patient characteristics, postoperative liver function, duration of hospital stay, and recipient survival rates were compared between the 2 groups. There were no significant differences between groups in recipient or donor background characteristics. The mean GV/SLV ratio of group S was 31.8%, whereas that of group L was 42.5%. There were no significant differences in the postoperative serum total bilirubin levels, prothrombin time international normalized ratio, daily ascites volume, or duration of postoperative hospital stay between the groups. The 1‐ and 5‐year survival rates in group S were 80.7% and 64.2%, respectively, whereas those of group L were 90.8% and 84.9%, respectively, with no significant difference between groups. In conclusion, graft size was not considered to be the only cause of so‐called small‐for‐size graft syndrome, and left side grafting appears to be the procedure of choice for adult‐to‐adult living donor liver transplantation because of the lower risk to donors in comparison with right lobe grafting. Liver Transpl 15:1622–1630, 2009.

Nonsurgical policy for treatment of bilioenteric anastomotic stricture after living donor liver transplantation

Biliary complications remain a significant cause of morbidity following living donor liver transplantation. The purpose of this retrospective study was to assess the outcome of nonsurgical management for hepatojejunostomy stricture in our institution. We reviewed 22 patients with hepatojejunostomy stricture among the 231 patients who underwent living donor liver transplantation between June 1990 and December 2005. Hepatojejunostomy stricture was confirmed by percutaneous transhepatic or endoscopic retrograde cholangiography. Anastomotic strictures were treated by balloon dilatation. Percutaneous transhepatic cholangiography was performed on 15 of the 22 patients. Two of 15 patients, with complete obstruction of the anastomosis, were treated successfully by Yamanouchi magnet compression anastomosis. Although another two patients died of infectious disease that was unlikely to have been related to biliary complications, anastomotic patency was maintained in the other 13 patients. Endoscopic retrograde cholangiography was performed on seven of the 22 patients. None of the 22 patients required re‐operation or died of biliary complications. The 5‐year graft survival rate of 85.6% in the 22 patients with stricture was equivalent to that of the patients without stricture (82.9%, Pu2003=u20030.98). Advances in intervention techniques have enabled wider application of nonsurgical approaches for this complication, and fair results have been obtained.

Iron Sucrose Impairs Phagocytic Function and Promotes Apoptosis in Polymorphonuclear Leukocytes

Background: With the recent implementation of bundling reimbursement policy, the use of intravenous (IV) iron preparations for the management of anemia in the end-stage renal disease (ESRD) population has dramatically increased. Iron overload increases the risk of infections in individuals with or without kidney disease. IV iron administration in ESRD patients impairs bacteriocidal capacity of polymorphonuclear leukocytes (PMNs) against Escherichia coli. These preparations consist of an elemental iron core and a carbohydrate shell. In addition to the iron core, the carbohydrate shell may affect PMNs. We therefore examined the effect of iron sucrose, a commonly used preparation, on phagocytic capacity of PMNs from a group of normal individuals against Gram-positive (Staphylococcus aureus) and Gram-negative (E. coli) bacteria. Methods: Iron sucrose was added to heparinized blood samples at pharmacologically-relevant concentrations and incubated for 4 and 24 h at 37°C to simulate in vivo condition. Blood samples mixed with equal volume of saline solution served as controls. To isolate the effects of the carbohydrate shell, blood samples were co-treated with the iron chelator, desferrioxamine. Results: Iron sucrose caused significant PMN apoptosis and dose-dependent suppression of phagocytic function against both Gram-positive and Gram-negative bacteria. These abnormalities were prevented by desferrioxamine which precluded contribution of the carbohydrate shell to the PMN dysfunction. Conclusions: At pharmacologically-relevant concentrations, iron sucrose promotes apoptosis and inhibits phagocytic activities of PMNs. The deleterious effect of iron sucrose is mediated by its elemental iron core, not its carbohydrate shell, and as such may be shared by other IV iron preparations.

The Effect of Nrf2 Pathway Activation on Human Pancreatic Islet Cells

Background Pancreatic islets are known to contain low level of antioxidants that renders them vulnerable to oxidative stress. Nrf2 is the master regulator of numerous genes, encoding antioxidant, detoxifying, and cytoprotective molecules. Activation of Nrf2 pathway induces up-regulation of numerous genes encoding antioxidant and phase II detoxifying enzymes and related proteins. However, little is known regarding the role of this pathway in human islet cells. The aim was to investigate the effect of Nrf2 activator (dh404, CDDO-9,11-dihydro-trifluoroethyl amide) on human islet cells. Methods Human islets were obtained from cadaveric donors. After dh404 treatment, Nrf2 translocation, mRNA expression, and protein abundance of its key target gene products were examined. The proportion of dh404-treated or non-treated viable islet beta cells was analyzed using flowcytemetry. The cytoprotective effects against oxidative stress and production of inflammatory mediators, and in vivo islet function after transplantation were determined. Results Nrf2 nuclear translocation was confirmed by con-focal microscope within 2 hours after treatment, which was associated with a dose-dependent increase in mRNA expression of anti-oxidants, including NQO1, HO-1, and GCLC. Enhanced HO-1 expression in dh404 treated islets was confirmed by Western Blot assay. Islet function after transplantation (2000 IEQ/mouse) to diabetic nude mice was not affected with or without dh404 treatment. After induction of oxidative stress with hydrogen peroxide (200 μM) the proportion of dh404-treated viable islet cells was significantly higher in the dh404-treated than untreated islets (74% vs.57%; P<0.05). Dh404 significantly decreased production of cytokines/chemokines including IL-1β, IL-6, IFN-γ and MCP-1. Conclusion Treatment of human pancreatic islets with the potent synthetic Nrf2 activator, dh404, significantly increased expression of the key anti-oxidants enzymes, decreased inflammatory mediators in islets and conferred protection against oxidative stress in beta cells.

Dimethyl Fumarate Protects Pancreatic Islet Cells and Non-Endocrine Tissue in L-Arginine-Induced Chronic Pancreatitis

Background Chronic pancreatitis (CP) is a progressive disorder resulting in the destruction and fibrosis of the pancreatic parenchyma which ultimately leads to impairment of the endocrine and exocrine functions. Dimethyl Fumarate (DMF) was recently approved by FDA for treatment of patients with multiple sclerosis. DMFs unique anti-oxidant and anti-inflammatory properties make it an interesting drug to test on other inflammatory conditions. This study was undertaken to determine the effects of DMF on islet cells and non-endocrine tissue in a rodent model of L-Arginine-induced CP. Methods Male Wistar rats fed daily DMF (25 mg/kg) or vehicle by oral gavage were given 5 IP injections of L-Arginine (250 mg/100 g×2, 1 hr apart). Rats were assessed with weights and intra-peritoneal glucose tolerance tests (IPGTT, 2 g/kg). Islets were isolated and assessed for islet mass and viability with flow cytometry. Non-endocrine tissue was assessed for histology, myeloperoxidase (MPO), and lipid peroxidation level (MDA). In vitro assessments included determination of heme oxygenase (HO-1) protein expression by Western blot. Results Weight gain was significantly reduced in untreated CP group at 6 weeks. IPGTT revealed significant impairment in untreated CP group and its restoration with DMF therapy (P <0.05). Untreated CP rats had pancreatic atrophy, severe acinar architectural damage, edema, and fatty infiltration as well as elevated MDA and MPO levels, which were significantly improved by DMF treatment. After islet isolation, the volume of non-endocrine tissue was significantly smaller in untreated CP group. Although islet counts were similar in the two groups, islet viability was significantly reduced in untreated CP group and improved with DMF treatment. In vitro incubation of human pancreatic tissue with DMF significantly increased HO-1 expression. Conclusion Administration of DMF attenuated L-Arginine-induced CP and islet function in rats. DMF treatment could be a possible strategy to improve clinical outcome in patients with CP.

Dimethyl fumarate ameliorates acute pancreatitis in rodent.

Objectives Pancreatitis is a complex inflammatory disorder, ranging from a mild attack, to severe and potentially fatal condition. Dimethyl fumarate (DMF), a potent antioxidant and anti-inflammatory, has been used medicinally for decades. The purpose of this study was to test the hypothesis that treatment with DMF may ameliorate acute pancreatitis (AP) in a rodent model. Methods Rats were treated with DMF (25 mg/kg) 24 hours prior to AP induction with l-arginine (3 g/kg). At 72 hours, the pancreas was processed for histology. Serum amylase, lactate dehydrogenase, pancreatic trypsin, and lipid peroxidation product (malondialdehyde) were evaluated. Key cytokines and chemokines in the supernatant of lipopolysaccharide-stimulated splenocytes were also determined. Results Pancreata from DMF-treated rats showed reductions in the severity of inflammatory cell infiltration, acinar damage, perilobar edema, and cell necrosis. This was associated with significantly lower amylase and malondialdehyde but not lactate dehydrogenase or trypsin levels. The apoptotic pancreatic cells (cleaved caspase 3 positive) were significantly lower in the DMF-treated rats. Lipopolysaccharide-stimulated splenocytes treated with DMF produced a significantly lower amount of key inflammatory mediators. Conclusion Administration of DMF attenuates AP in rats.

Temporary Auxiliary Partial Orthotopic Liver Transplantation Using a Small Graft for Familial Amyloid Polyneuropathy

Donor shortage is a major issue in liver transplantation. We have successfully performed temporary auxiliary partial orthotopic liver transplantation (APOLT) using a small volume graft procured from a living donor for recipients with familial amyloid polyneuropathy (FAP). The aim of this study was to evaluate this procedure by comparing it with standard living donor liver transplantation (LDLT). We compared 13 recipients undergoing this procedure with 23 recipients undergoing a standard LDLT for the treatment of FAP. The estimated donor graft volume and the graft volume/recipients standard liver volume ratio were significantly smaller in the temporary APOLT group than in the standard LDLT group. Postoperative complications were comparable, although the hospital stay was longer in the temporary APOLT group. All the patients safely underwent a remnant native liver resection about 2 months after their first operation in the temporary APOLT group. No symptoms related to FAP developed before the remnant liver resection, and no significant differences in graft and patient survival were observed between the two groups. We successfully performed temporary APOLT using a small volume liver graft without postoperative liver failure for FAP. Temporary APOLT for FAP might be a useful alternative procedure for expanding the donor pool for LDLT.

Administration of Dalteparin Based on the Activated Clotting Time for Prophylaxis of Hepatic Vessel Thrombosis in Living Donor Liver Transplantation

Beginning in 2004, dalteparin doses based on activated clotting time (ACT) were administered for hepatic vessel thrombosis prophylaxis in living donor liver transplantation (LDLT). We verified the feasibility of this new therapy by comparing it with the previous one. From 1993 through 2008, 42 metabolic liver patients who underwent LDLT were divided into two groups. Group A (1993-2003, n = 32) was administered a fixed dalteparin dose and a large amount of fresh frozen plasma (FFP); Group B (2004-2008, n = 10) was administered an appropriate dosage of dalteparin to maintain the ACT levels from 140 to 150 seconds and a small amount of FFP. Group B was administered a lesser amount of FFP and more dalteparin. This resulted in longer activated partial thromboplastin time, lower fibrinogen degradation products D-dimer, and lower aspartate aminotransferase levels compared to group A; all differences were significant. Group B showed neither thrombotic nor hemorrhagic complications. Anticoagulation therapy comprising adjustment of the dalteparin dose based on ACT reduces thrombotic complications without increasing hemorrhagic complications. ACT measurement is a simple, reliable method for bedside monitoring of dalteparin anticoagulant effects for LDLT.

Arterial reconstruction in a case of subintimal dissection of celiac arterial tributaries in living donor liver transplantation: a case report.

BACKGROUNDnHepatic arterial reconstruction is one of the critical issues in living donor liver transplantation (LDLT). Herein we have reported an LDLT case whose celiac arterial trunk tributaries were insufficient as host arteries because of extensive subintimal dissection proceeding to all tributaries of the celiac arterial trunk.nnnPATIENTS AND METHODSnA 45-year-old woman with fulminant hepatic failure underwent LDLT. After reperfusion of the hepatic and portal veins, subintimal dissection of the recipient right and left hepatic arteries was found to extend to all tributaries of the celiac arterial trunk, preventing an anastomosis using the more proximal part of these arteries. Therefore, a jejunal arterial arcade of Roux-en-Y limb mobilized for biliary reconstruction was anastomosed to the donor left hepatic artery in end-to-end fashion.nnnRESULTSnArterial blood flow to the grafted liver was established successfully, and the patients postoperative recovery was excellent. Postoperative computed tomography demonstrated sufficient hepatic arterial blood flow. The patient is doing well 4 years after transplantation.nnnCONCLUSIONnThe method of hepatic graft arterialization described herein is an important option for LDLT recipients when tributaries of the celiac arterial trunk are insufficient as host arteries.