Katsuji Tokuhara

Protective effect of FR183998, a Na+/H+ exchanger inhibitor, and its inhibition of iNOS induction in hepatic ischemia-reperfusion injury in rats.

Recent evidence indicates that inhibition of the Na+/H+ exchanger improves heart and brain injuries induced by I/R. Studies were performed to investigate whether FR183998, a Na+/H+ exchanger inhibitor, has protective effects on hepatic I/R injury in rats. Male Sprague-Dawley rats were subjected to 70% hepatic ischemia by occluding the hepatic artery, portal vein, and bile duct associated with the left and median liver lobes with a microvascular clip for 2 h. FR183998 (1 mg/kg) was administered i.v. 10 min before the hepatic ischemia. Hepatic I/R increased the serum levels of aspartate transaminase, alanine transaminase, and lactate dehydrogenase, which peaked at 9 h after reperfusion. FR183998 reduced these injury markers and recovered liver functions. Histopathologic analysis revealed that FR183998 prevented the incidences of hepatic necrosis, apoptosis, and neutrophil infiltration at 6 and 9 h (P < 0.05). FR183998 reduced the increases in proinflammatory cytokines such as TNF-&agr; (1 - 6 h), IL-6 (1 - 12 h), interferon-&ggr; (6 - 12 h), IL-1&bgr; (1 - 3 h), and cytokine-induced neutrophil chemoattractant 1 (1-3 h), but enhanced the anti-inflammatory cytokine IL-10 (1 h). FR183998 inhibited the hepatic I/R-induced activation of the transcription factor nuclear factor-&kgr;B at 1 to 6 h and reduced the induction of iNOS at 6 to 12 h, followed by inhibition of nitric oxide production. Furthermore, FR183998 decreased the expression of the iNOS gene antisense transcript, which is involved in the stability of iNOS messenger RNA, at 9 to12 h in the liver of hepatic I/R rats. These results demonstrate that FR183998 reduces the induction of proinflammatory cytokines and iNOS at least in part through inhibition of nuclear factor-&kgr;B activation and iNOS antisense transcript expression, thereby preventing hepatic I/R injury.ABBREVIATIONS - NHE-Na+/H+ exchanger; I/R-ischemia/reperfusion; NO-nitric oxide; iNOS-inducible nitric oxide synthase; TNF-&agr;-tumor necrosis factor-&agr;; CINC-1-cytokine-induced neutrophil chemoattractant 1; IFN-&ggr;-interferon-&ggr;; IL-interleukin; NF-&kgr;B-nuclear factor-&kgr;B

Duodenogastric reflux following biliary reconstruction after excision of choledochal cyst

Duodenogastric reflux (DGR) was assessed in patients surgically treated for choledochal cyst, with emphasis on two different biliary reconstruction methods: Roux-en-Y hepaticojejunostomy (HJ) and hepaticoduodenostomy (HD). Gastric bile monitoring with the Bilitec device revealed excessive DGR in patients in the HD group. Endoscopic findings demonstrated mild to moderate gastric mucosal erosion in patients after HD. In contrast, neither DGR nor gastritis was found in patients after HJ. This preliminary study suggests that HJ, rather than HD, should be recommended as a method of biliary reconstruction for pediatric patients with choledochal cyst. Careful observation of DGR should be continued in patients who have undergone HD.

Magnetic resonance cholangiopancreatography on postoperative work-up in children with choledochal cysts

This study aimed to assess the clinical usefulness of magnetic resonance cholangiopancreatography (MRCP) as a postoperative diagnostic tool in children with choledochal cysts. Magnetic resonance cholangiopancreatography was performed postoperatively in 19 patients and image quality was compared with that obtained by intravenous cholangiography spiral computed tomography (IVC-SCT). While the detectability by MRCP was inferior to that by IVC-SCT, MRCP highly (84.2%) depicted the anastomotic site together with the reconstructed bowel and intrahepatic bile ducts. Magnetic resonance cholangiopancreatography also clearly delineated the postoperative condition of pancreaticobiliary maljunction (PBM), residual distal common bile duct, common channel, and pancreatic duct. Since MRCP is noninvasive and requires neither radiation exposure nor a contrast agent, and is useful for detecting both anastomosis and pancreatico-biliary ducts around PBM, MRCP might be superior to IVC-SCT as an imaging technique for outpatient clinics performing long-term follow-up studies in children with choledochal cysts.

Influence of Rictor and Raptor Expression of mTOR Signaling on Long-Term Outcomes of Patients with Hepatocellular Carcinoma

BackgroundAberrant signaling mediated by the mammalian target of rapamycin (mTOR) occurs at high frequency in hepatocellular carcinoma (HCC), indicating that mTOR is a candidate for targeted therapy. mTOR forms two complexes called mTORC1 (mTOR complexed with raptor) and mTORC2 (mTOR complexed with rictor). There are minor studies of the expression kinetics of mTORC1 and mTORC2 in HCC.MethodsWe studied 62 patients with HCC who underwent curative resection. We used univariate and multivariate analyses to identify factors that potentially influence disease and overall survival after hepatectomy. The mRNA and protein levels of mTOR, rictor and raptor in cancer and non-cancer tissues were analyzed using quantitative RT-PCR, immunohistochemistry and Western blotting.Results/ConclusionHigh ratio of the levels of rictor and raptor mRNAs in tumors was identified as independent prognostic indicators for disease-free survival. Low and high levels of preoperative serum albumin and mTOR mRNA in the tumor, respectively, were identified as independent indicators of overall survival. HCC is likely to recur early after hepatic resection in patients with high levels of mTOR and rictor mRNAs and high rictor/raptor ratios in cancer tissues. We conclude that analysis of mTOR expression in cancer tissues represents an essential strategy to predict HCC recurrence after curative treatment.

Alpha-lipoic acid exerts a liver-protective effect in acute liver injury rats

BACKGROUND Recent evidence indicates that alpha-lipoic acid (α-LA) has a variety of liver-protective effects through the suppression of inflammatory mediators including tumor necrosis factor (TNF)-α and inducible nitric oxide synthase (iNOS). However, there are few reports that α-LA markedly enhanced the survival rate in animal models of liver injury with more than 90% death. The aim of this study was to investigate the beneficial effects of α-LA in a rat model of acute liver injury and to clarify the mechanisms of α-LA action. METHODS Rats were treated with d-galactosamine and lipopolysaccharide (GalN and LPS) to induce acute liver injury. α-LA (100 mg/kg) was administered intraperitoneally 1 h before GalN and LPS injection. Inflammatory mediators including TNF-α and iNOS were analyzed. RESULTS A single injection of α-LA improved the survival rate by more than 80%. α-LA prevented serum transaminase increases, histopathologic changes, and apoptosis in the liver. In the serum, α-LA decreased TNF-α production and increased interleukin (IL)-10 production. In the liver, α-LA reduced TNF-α and IL-6 messenger RNA (mRNA) but enhanced IL-10 mRNA. α-LA decreased the expression of iNOS mRNA and its antisense transcript, leading to the reduction of iNOS protein expression and resulting in the inhibition of nitric oxide production. An electrophoretic mobility shift assay revealed that α-LA reduced the activation of nuclear factor-kappa B induced by GalN and LPS. CONCLUSIONS α-LA inhibited the induction of inflammatory mediators, such as TNF-α and iNOS, in part through the inhibition of nuclear factor-kappa B activation and enhanced the induction of IL-10. α-LA may have therapeutic potential for use in the prevention of acute liver injury.

Atypical ductal hyperplasia of the pancreas associated with a stricture of the main pancreatic duct.

Atypical ductal hyperplasia of the pancreas is thought to be a precancerous lesion. We report a case of atypical ductal hyperplasia associated with a stricture of the main pancreatic duct. A 70-year-old man was admitted to our hospital because of abdominal pain with an elevated serum pancreatic isoamylase level. Endoscopic retrograde cholangiopancreatography disclosed a stricture of the main pancreatic duct in the body of the pancreas. Cytological evaluation of endoscopic brushings suggested adenocarcinoma. Distal pancreatec-tomy was performed. Microscopic examination of the stenotic pancreatic duct showed a hyperplastic epithelium without atypia. Atypical hyperplasia, however, was found in the distal portion of the main pancreatic duct in close proximity to the stricture. Atypical hyperplasia extended along the main pancreatic duct into the ductal branches of the pancreatic tail. In contrast to the vast majority of patients with atypical hyperplasia, the atypical hyperplasia seen in the present patient had no histological features suggestive of intraductal extension of the invasive carcinoma or intraductal papillary-mucinous tumor, thus representing a sporadic precancerous lesion, and it may have been equivalent to carcinoma in situ. Pancreatic duct stricture and the resultant stasis of the pancreatic juice may have promoted the atypical changes in the ductal cells upstream of the stricture.

Effect of Thiol-Containing Molecule Cysteamine on the Induction of Inducible Nitric Oxide Synthase in Hepatocytes

BACKGROUND Cysteamine, which is a known antioxidant and anti-inflammatory agent, is believed to be a key regulator of essential metabolic pathways in organisms. Cysteamine has beneficial effects in liver damaged by a variety of insults. During liver injury, inducible nitric oxide synthase (iNOS) is induced by lipopolysaccharide or proinflammatory cytokines, leading to excessive nitric oxide (NO) production. Accumulated evidence indicates that NO is an important factor associated with hepatic dysfunction. We examined whether cysteamine influences the induction of iNOS in hepatocytes. METHODS Primary cultured rat hepatocytes were treated with interleukin (IL)-1beta in the presence and absence of cysteamine. NO production, iNOS induction, and iNOS signal were analyzed. RESULTS IL-1beta stimulated the inhibitory protein kappaB (IkappaB)/nuclear factor kappaB (NFkappaB) pathway, resulting in the activation of NFkappaB (nuclear translocation and DNA binding), which was followed by the induction of iNOS and NO production. The addition of IL-1beta and cysteamine (1-4 mmol/L) markedly inhibited NO production, with a maximal effect at 4 mmol/L (80%-90% inhibition). Cysteamine also decreased the levels of iNOS protein and mRNA. Transfection experiments revealed that cysteamine decreased the transactivation activity of the iNOS promoter. An electrophoretic mobility shift assay demonstrated that cysteamine inhibited the activation of NFkappaB. Furthermore, cysteamine decreased the mRNA levels of the NFkappaB subunit p65 but increased those of the inhibitory protein IkappaB. CONCLUSIONS These findings suggest that cysteamine inhibits iNOS induction at the step of NFkappaB activation. Further study is necessary to define the molecular basis of this effect of cysteamine on the regulation of NFkappaB and its pharmacologic implications.

Fluvastatin inhibits the induction of inducible nitric oxide synthase, an inflammatory biomarker, in hepatocytes.

Statins (3‐hydroxy‐3‐methylglutaryl coenzyme A [HMG‐CoA] reductase inhibitors), which were originally designed to lower plasma cholesterol levels, are increasingly recognized as anti‐inflammatory agents. In the inflamed liver, pro‐inflammatory cytokines stimulate the induction of inducible nitric oxide synthase (iNOS). Overproduction of NO by iNOS has been implicated as a factor in liver injury. We examined pro‐inflammatory cytokine‐stimulated hepatocytes as a simple in vitro injury model to determine liver‐protective effects of statins. We hypothesized that statins are involved in the downregulation of iNOS, resulting in decreased hepatic inflammation.

Low-grade mucinous neoplasia in a cecal diverticulum: A case report

Highlights • There are no previous reports of mucocele disease in a colonic diverticulum worldwide.• Laparoscopic ileocecal resection was chosen because of its minimal invasiveness and the patient had no evidence of recurrence 12 months postoperatively.• The possibility of a mucocele in a colonic diverticulum should be considered in patients with a colonic SMT.

Japanese Kampo Medicine, Ninjinyoeito, Inhibits the Induction of iNOS Gene Expression in Proinflammatory Cytokine-Stimulated Hepatocytes

This work was carried out in collaboration between all authors. Authors YT, HM, MO and RN managed the analyses of the study. Author YT performed the statistical analysis, wrote the protocol and wrote the first draft of the manuscript. Authors MK, KT, MN, TO and AHK managed the coordination of the study. Authors MK, TO and MN conceived the study and participated in its design. This work was carried out in collaboration between all authors. All authors read and approved the final manuscript.