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Featured researches published by Shintaro Kodai.


Hepatology Research | 2007

Effects of lamivudine on outcome after liver resection for hepatocellular carcinoma in patients with active replication of hepatitis B virus

Shoji Kubo; Hiromu Tanaka; Shigekazu Takemura; Satoshi Yamamoto; Seikan Hai; Tsuyoshi Ichikawa; Shintaro Kodai; Hiroji Shinkawa; Hiroki Sakaguchi; Akihiro Tamori; Daiki Habu; Shuhei Nishiguchi

Aim:  Patients with high serum hepatitis B virus (HBV) DNA concentrations are at high risk of tumor recurrence after liver resection for HBV‐related hepatocellular carcinoma (HCC).


Journal of Pharmacology and Experimental Therapeutics | 2006

Calorie Restriction Improves Cardiovascular Risk Factors via Reduction of Mitochondrial Reactive Oxygen Species in Type II Diabetic Rats

Yukiko Minamiyama; Yasuyuki Bito; Shigekazu Takemura; Yosuke Takahashi; Shintaro Kodai; Shinjiro Mizuguchi; Yuriko Nishikawa; Shigefumi Suehiro; Shigeru Okada

Uncoupling protein 2 (UCP2) is an important regulator of intracellular reactive oxygen species (ROS) production. We determined the effects of calorie restriction (CR) on the dynamic aspects of mitochondrial ROS production, UCP2, and the nitric oxide (NO)-cGMP pathway in the cardiovascular tissues of type II diabetic Otsuka Long-Evans Tokushima Fatty (OLETF) rats. Some rats were on restricted diets (30% reduction from free intake) from age 29 to 42 weeks. Blood glucose, hemoglobin A1c, plasma levels of free fatty acid, triacylglycerol, and plasminogen activator inhibitor-1 in OLETF rats were significantly higher than those in nondiabetic control [Long-Evans Tokushima Otsuka (LETO)] rats at 29 weeks. Mitochondrial ROS production and UCP2 expression significantly increased in the heart and aorta of OLETF rats compared with those in LETO rats. A fibrogenic growth factor, transforming growth factor (TGF)-β1 in the coronary vessels, endothelial nitric-oxide synthase, and aortic nitrotyrosine were increased in OLETF rats at 42 weeks. In contrast, an index of the NO-cGMP pathway, phosphorylated vasodilator-stimulated phosphoprotein, and superoxide dismutase activity in the aorta were significantly diminished. The relationship between UCP2 and ROS production in the cardiovascular function of diabetic rats being fed a calorie-restricted diet is unknown. These abnormalities in OLETF rats were reversed to normal levels by CR. CR significantly improved the NO-cGMP pathway via normalizing ROS generation in OLETF rats. A decrease in UCP2 expression by CR may be a compensatory mechanism to counteract decreased intracellular oxidative stress. The data suggest that CR may prevent cardiovascular tissues from oxidative stress provoked by diabetes mellitus.


American Journal of Physiology-endocrinology and Metabolism | 2010

Iron restriction improves type 2 diabetes mellitus in Otsuka Long-Evans Tokushima fatty rats

Yukiko Minamiyama; Shigekazu Takemura; Shintaro Kodai; Hiroji Shinkawa; Takuma Tsukioka; Hiroshi Ichikawa; Yuji Naito; Toshikazu Yoshikawa; Shigeru Okada

Accumulating evidence suggests that alcohol, hepatitis C virus infection, steatosis with obesity, and insulin resistance are accompanied by iron overload states. Phlebotomy and oral iron chelators are effective treatments for these conditions and for hemochromatosis. However, the mechanisms by which iron depletion improves clinical factors remain unclear. We examined the effect of iron depletion in a model of type 2 diabetes, Otsuka Long-Evans Tokushima Fatty (OLETF) rats. Age-matched Long-Evans Tokushima Otsuka (LETO) rats were used as controls for all experiments. Iron restriction was performed by eliminating iron in the diet from 15 wk of age or by phlebotomy. Phlebotomy was commenced at 29 wk of age by removing 4 and 3 ml of blood from the tail vein every week in OLETF and LETO rats, respectively. Rats were euthanized at 43 wk of age, and detailed analyses were performed. The plasma ferritin concentration was markedly higher in OLETF rats and decreased in iron-deficient (ID) diet and phlebotomy rats. Hemoglobin A(1c) (Hb A(1c)) was decreased significantly in OLETF rats fed the ID diet and in the phlebotomy group. Increased levels of triglycerides, glucose, free fatty acids, and total cholesterol were found in ID OLETF rats. Plasma, liver, and pancreas lipid peroxidation and hepatic superoxide production decreased in both groups. Pancreatic fibrosis and insulin levels improved in both groups of OLETF rats. Pancreatic levels of peroxisome proliferator-activated receptor-beta/delta (PPARbeta/delta) ligands and hypoxia-inducible factor (HIF)-1alpha were decreased significantly in OLETF rats. These factors were normalized in both rats fed ID and phlebotomy groups of OLETF rats. In conclusion, iron depletion improved diabetic complications by inhibition of oxidative stress and TGFbeta signal pathways and the maintenance of pancreatic PPARbeta/delta and HIF-1alpha pathways.


Analytical Biochemistry | 2008

Simultaneous measurement of F2-isoprostane, hydroxyoctadecadienoic acid, hydroxyeicosatetraenoic acid, and hydroxycholesterols from physiological samples

Yasukazu Yoshida; Shintaro Kodai; Shigekazu Takemura; Yukiko Minamiyama; Etsuo Niki

Oxidative stress induced by various oxidants in a random and destructive manner is considered to play an important role in the pathophysiology of a number of human disorders and diseases. It is important to assess the oxidative injury in vivo accurately and inclusively. We have developed an improved method for the measurement of in vivo lipid peroxidation by using a single plasma or liver sample, where total 8-iso-prostaglandin F(2alpha) (t8-iso-PGF(2alpha)), total hydroxyoctadecadienoic acids (tHODEs), total hydroxyeicosatetraenoic acids (tHETEs), and total 7-hydroxycholesterol (t7-OHCh), as well as their parent molecules linoleic acid (t18:2) and cholesterol (tCh), are determined by LC-MS/MS (for t8-iso-PGF(2alpha), tHODE, and tHETE) and GC-MS (for t7-OHCh, t18:2, and tCh) analyses. The plasma and liver samples from human are reduced with sodium borohydride and saponified by potassium hydroxide after the addition of heavy isotopic standards. After extraction by chloroform/ethyl acetate (CHCl(3)/CH(3)COOC(2)H(5), 4:1), they are analyzed without any further sample processing. We applied this method to hepatitis C virus-infected patients (n=8, plasma and liver), hepatitis B virus-infected patients (n=2, plasma and liver), and controls (virus free, n=8, plasma and liver). It was found that in the plasma of patients and controls, the concentrations of oxidized lipids decreased in the following order: tHODE tHETE t7-OHCh >> t8-iso-PGF(2alpha). As expected, the virus clearly increased these concentrations. The ratio of stereoisomers of HODE [(E,E)-HODE/(E,Z)-HODE], which reflects the antioxidant capacity in vivo, can also be determined by this method. A significant decrease in the stereoisomer ratio for the liver of patients was observed, indicating liver dysfunction. t8-iso-PGF(2alpha), tHODE, tHETE, and t7-OHCh are measured satisfactorily and inclusively by the current method from biological fluids and tissues, and they can account for a large portion of oxidized lipids in vivo.


Free Radical Research | 2007

S-allyl cysteine prevents CCl4-induced acute liver injury in rats

Shintaro Kodai; Shigekazu Takemura; Yukiko Minamiyama; Seikan Hai; Satoshi Yamamoto; Shoji Kubo; Yasukazu Yoshida; Etsuo Niki; Shigeru Okada; Kazuhiro Hirohashi; Shigefumi Suehiro

Aged garlic extract (AGE) possesses multiple biological activities. We evaluated the protective effect of S-allyl cysteine (SAC), one of the organosulfur compounds of AGE, against carbon tetrachloride (CCl4)-induced acute liver injury in rats. SAC was administrated intraperitoneally (50–200 mg/kg). SAC significantly suppressed the increases of plasma ALT and LDH levels. SAC also attenuated histological liver damage. CCl4 administration induced lipid peroxidation accompanied by increases in the plasma malondialdehyde and hepatic 4-hydroxy-2-nonenal levels, and SAC dose-dependently attenuated these increases. The hepatic total level of hydroxyoctadecadienoic acid (HODE), a new oxidative stress biomarker, was closely correlated with the amount of liver damage. These results suggest that SAC decreased CCl4-induced liver injury by attenuation of oxidative stress, and may be a better therapeutic tool for chronic liver disease.


Journal of Hepato-biliary-pancreatic Surgery | 2009

A simple, noninvasively determined index predicting hepatic failure following liver resection for hepatocellular carcinoma

Tsuyoshi Ichikawa; Takahiro Uenishi; Shigekazu Takemura; Kazuki Oba; Masao Ogawa; Shintaro Kodai; Hiroji Shinkawa; Hiromu Tanaka; Takatsugu Yamamoto; Shogo Tanaka; Satoshi Yamamoto; Seikan Hai; Taichi Shuto; Kazuhiro Hirohashi; Shoji Kubo

BACKGROUND A novel index, the serum aspartate aminotransferase activity/platelet count ratio index (APRI), has been identified as a biochemical surrogate for histological fibrogenesis and fibrosis in cirrhosis. We evaluated the ability of preoperative APRI to predict hepatic failure following liver resection for hepatocellular carcinoma. METHODS Potential preoperative risk factors for postoperative hepatic failure (hepatic coma with hyperbilirubinemia, four patients; intractable pleural effusion or ascites, 30 patients; and variceal bleeding, one patient) as well as APRI were evaluated in 366 patients undergoing liver resection for hepatocellular carcinoma. Prognostic significance was determined by univariate and multivariate analyses. RESULTS Hepatic failure developed postoperatively in 30 patients, causing death in four. APRI correlated with histological intensity of hepatitis activity and degree of hepatic fibrosis, and was significantly higher in patients who developed postoperative hepatic failure than in others without failure. Risk of postoperative hepatic failure increased as the serum albumin concentration and platelet count decreased and as indocyanine green retention rate at 15 min, aspartate and alanine aminotransferase activities, and APRI increased. Only APRI was an independent preoperative factor on multivariate analysis. Of the four patients who died of postoperative hepatic failure, three had an APRI of at least 10. CONCLUSIONS Preoperative APRI independently predicted hepatic failure following liver resection for hepatocellular carcinoma. Patients with an APRI of 10 or more have a high risk of postoperative hepatic failure.


Surgery Today | 2007

Surgical treatment for hepatocellular carcinoma detected after successful interferon therapy.

Shoji Kubo; Hiromu Tanaka; Shigekazu Takemura; Satoshi Yamamoto; Seikan Hai; Tsuyoshi Ichikawa; Shintaro Kodai; Hiroji Shinkawa; Taichi Shuto; Kazuhiro Hirohashi

PurposeInterferon therapy suppresses the development of hepatocellular carcinoma (HCC) and tumor recurrence after a resection of HCC in patients with chronic hepatitis C. However, the value of a liver resection and which method is best for the treatment of HCC detected after successful interferon therapy remains to be clarified. The risk factors for tumor recurrence after a liver resection for HCC detected after successful interferon therapy were investigated to determine the appropriate operative method for such HCC.MethodsRisk factors including the clinicopathologic findings and the operative methods for tumor recurrence were evaluated by univariate and multivariate analyses in 24 patients who underwent liver resection for HCC detected after successful interferon therapy (sustained viral response or biochemical response).ResultsAccording to a univariate analysis, large tumor (>2 cm, P = 0.0326), multiple tumors (P = 0.0372), nonanatomic resection (P = 0.0103), and positive surgical margin (<5 mm of a free surgical margin, P = 0.0245) were possible risk factors for short tumor-free survival time after surgery. A multivariate analysis showed that large tumor (P = 0.0407), nonanatomic resection (P = 0.0215), and positive surgical margin (P = 0.0253) were independent risk factors for a short tumor-free survival time after surgery.ConclusionAn anatomic resection with an appropriate surgical margin (≥5 mm of a free surgical margin) is recommended for patients with HCC detected after successful interferon therapy.


Hepatology Research | 2012

Effect of interferon therapy on first and second recurrence after resection of hepatitis C virus-related hepatocellular carcinoma

Masayuki Sakae; Shoji Kubo; Shigekazu Takemura; Chikaharu Sakata; Takahiro Uenishi; Shintaro Kodai; Hiroji Shinkawa; Yorihisa Urata; Kazunori Ohata; Kazuhisa Kaneda; Takayoshi Nishioka; Akinori Nozawa; Shigefumi Suehiro

Aim:  Several investigators have shown that interferon (IFN) therapy can suppress the recurrence of hepatocellular carcinoma (HCC) after curative treatment. We investigated the effect of IFN therapy on the first and second HCC recurrence following hepatic resection of hepatitis C virus (HCV)‐related HCC.


Journal of Clinical Biochemistry and Nutrition | 2015

Therapeutic administration of an ingredient of aged-garlic extracts, S-allyl cysteine resolves liver fibrosis established by carbon tetrachloride in rats.

Shintaro Kodai; Shigekazu Takemura; Shoji Kubo; Hideki Azuma; Yukiko Minamiyama

S-allyl cysteine (SAC) is the most abundant compound in aged garlic extracts (AGEs). AGE has been reported to ameliorate the oxidative damage implicated in a variety of diseases. However, the effects of SAC have not been established in liver cirrhosis. The aim of this study was to examine the effect of therapeutic administration of SAC in liver cirrhosis by chronic carbon tetrachloride (CCl4) administration in rats. SAC or other cysteine compounds were administered from 4 weeks when liver fibrosis was confirmed to be in process. CCl4 administration elevated plasma alanine aminotransferase, plasma lipid peroxidation, liver hydroxyproline, and liver transforming growth factor (TGF)-β at 12 weeks. SAC prevented these changes induced by CCl4. Furthermore, SAC improved survival in a dose-dependent manner following consecutive CCl4 administration. The inhibitory mechanisms may be associated with a decrease in the profibrogenic cytokine, TGF-β as well as the antioxidative properties of SAC.


Hepato-gastroenterology | 2012

Features and outcome after liver resection for non-B non-C hepatocellular carcinoma.

Kazuhisa Kaneda; Shoji Kubo; Hiroshi Tanaka; Shigekazu Takemura; Kazuki Ohba; Takahiro Uenishi; Shintaro Kodai; Hiroji Shinkawa; Yorihisa Urata; Masayuki Sakae; Takatsugu Yamamoto; Shigefumi Suehiro

BACKGROUND/AIMS We investigated the clinicopathological findings and outcome after surgery for hepatocellular carcinoma in patients without hepatitis B or C virus infection. METHODOLOGY Among 562 patients who underwent curative resection for hepatocellular carcinoma, the sera from 97 patients (B group) were positive for hepatitis B surface antigen alone, sera from 355 patients (C group) were positive for anti-hepatitis C virus antibody alone and sera from 104 patients (NBNC group) were negative for both hepatitis B surface antigen and anti-hepatitis C virus antibody. We compared the clinicopathological findings and postoperative outcomes in the 3 groups. RESULTS The prevalence of diabetes mellitus, hypertension, hyperlipidemia and alcohol abuse were higher in the NBNC group than in the other groups. The prevalence of obesity was higher in the NBNC group than in the B group. Non-alcoholic steatohepatitis was detected in 16 NBNC patients. The tumor- free survival rate was higher in the NBNC group than in the C group. CONCLUSIONS Obesity, diabetes mellitus, hypertension, hyperlipidemia, alcohol abuse and non-alcoholic steatohepatitis were the possible risk factors for hepatocellular carcinoma in the NBNC group. The patients in the NBNC group are expected to show a better outcome as compared to patients in the C group.

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