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Dive into the research topics where Yasuhiko Sawada is active.

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Featured researches published by Yasuhiko Sawada.


Hepatology Research | 2017

Predictive parameter of tolvaptan effectiveness in cirrhotic ascites

Hideto Kawaratani; Hiroshi Fukui; Kei Moriya; Ryuichi Noguchi; Tadashi Namisaki; Masakazu Uejima; Mitsuteru Kitade; Kosuke Takeda; Yasushi Okura; Kosuke Kaji; Norihisa Nishimura; Hiroaki Takaya; Yousuke Aihara; Yasuhiko Sawada; Shinya Sato; Kenichiro Seki; Akira Mitoro; Junichi Yamao; Hitoshi Yoshiji

The efficacy of the vasopressin V2 receptor antagonist tolvaptan for difficult‐to‐treat cirrhotic ascites has recently been reported. However, its effect is variable among patients. This study aimed to clarify the predictive factors for obtaining a good response to tolvaptan in patients with difficult‐to‐treat ascites.


Hepatology Research | 2017

Combination treatment of dipeptidyl peptidase IV inhibitor (sitagliptin) and angiotensin-II type 1 receptor blocker (losartan) suppresses progression in a nondiabetic rat model of steatohepatitis

Yasushi Okura; Tadashi Namisaki; Kei Moriya; Mitsuteru Kitade; Kosuke Takeda; Kosuke Kaji; Ryuichi Noguchi; Norihisa Nishimura; Kenichiro Seki; Hideto Kawaratani; Hiroaki Takaya; Shinya Sato; Yasuhiko Sawada; Naotaka Shimozato; Masanori Furukawa; Keisuke Nakanishi; Saikawa Soichiro; Takuya Kubo; Kiyoshi Asada; Hitoshi Yoshiji

Dipeptidyl peptidase‐4 (DPP4) inhibitors (DPP4‐I) are oral glucose‐lowering drugs for type 2 diabetes mellitus. Previously, we reported that DPP4‐I (sitagliptin) exerted suppressive effects on experimental liver fibrosis in rats. Blockade of the renin–angiotensin system by angiotensin‐II type 1 receptor blocker (losartan), commonly used in the management of hypertension, has been shown to significantly alleviate hepatic fibrogenesis and carcinogenesis. We aimed to elucidate the effects and possible mechanisms of a sitagliptin + losartan combination on the progression of non‐diabetic non‐alcoholic steatohepatitis (NASH) in a rat model.


Molecular Medicine Reports | 2017

Periostin cross‑reacts with the renin‑angiotensin system during liver fibrosis development

Kosuke Takeda; Ryuichi Noguchi; Mitsuteru Kitade; Tadashi Namisaki; Kei Moriya; Hideto Kawaratani; Yasushi Okura; Kosuke Kaji; Yosuke Aihara; Akitoshi Douhara; Norihisa Nishimura; Yasuhiko Sawada; Kenichiro Seki; Hitoshi Yoshiji

Periostin is a 90-kDa extracellular matrix protein, which is secreted primarily from fibroblasts and is expressed in the lungs, kidneys and heart valves. Angiotensin II (AT-II) serves pivotal roles in the pathogenesis of several diseases with accompanying fibrosis, including chronic liver diseases. AT-II induces periostin expression by regulating transforming growth factor-β1 (TGF-β1)/Smad signaling during cardiac fibrosis. The aim of the present study was to investigate the interaction between AT-II and periostin during liver fibrosis development. Fischer 344 rats were fed a choline-deficient L-amino-acid (CDAA)-defined diet for 12 weeks to simulate the development of steatohepatitis with liver fibrosis. Losartan, an AT-II type I receptor blocker, was administered to inhibit the effect of AT-II. The therapeutic effect of losartan on hepatic fibrosis development and on periostin expression was then evaluated. Several in vitro experiments were performed to examine the mechanisms underlying the interaction between AT-II and periostin in activated hepatic stellate cells (Ac-HSCs). Treatment with losartan suppressed the development of liver fibrosis induced by the CDAA diet, and reduced hepatic periostin expression. In addition, losartan treatment suppressed hepatic Ac-HSC expansion and hepatic TGF-β1 expression. In vitro analysis using LX2 HSC cells indicated that AT-II can augment TGF-β1 and collagen type I α1 mRNA expression via periostin expression, suggesting that the interaction between AT-II and periostin may serve a role in liver fibrosis development. In conclusion, blockade of AT-II-induced periostin may suppress the progression of liver fibrosis development.


European Journal of Gastroenterology & Hepatology | 2017

Clinical significance of the Scheuer histological staging system for primary biliary cholangitis in Japanese patients.

Tadashi Namisaki; Kei Moriya; Mitsuteru Kitade; Hideto Kawaratani; Kosuke Takeda; Yasushi Okura; Hiroaki Takaya; Norihisa Nishimura; Kenichiro Seki; Kosuke Kaji; Shinya Sato; Yasuhiko Sawada; Junichi Yamao; Akira Mitoro; Masakazu Uejima; Tsuyoshi Mashitani; Naotaka Shimozato; Keisuke Nakanishi; Masanori Furukawa; Soichiro Saikawa; Takuya Kubo; Hitoshi Yoshiji

Background Inadequate response to ursodeoxycholic acid (UDCA) is associated with unfavorable outcomes in patients with primary biliary cholangitis (PBC). We aimed to identify surrogate markers for predicting long-term prognosis and biochemical response to UDCA in patients with PBC. Patients and methods In this single-center, retrospective study, 99 patients with PBC were classified into responders (n=53) and nonresponders (n=46) based on reductions in the &ggr;-glutamyl transpeptidase levels at 1 year after initiating UDCA therapy (Nara criteria). We assessed whether the criteria for patentability by different countries are useful in predicting the prognosis of PBC. The accuracy of Scheuer and Nakanuma staging systems in predicting prognosis and treatment response was compared. Results Nara definition had comparable utility to the Paris-II definition for selecting patients in whom UDCA monotherapy can be safely continued. Patients at Scheuer stage 1 had a significantly better prognosis than those at Scheuer stages 3 or 4 (P<0.05 and 0.0001, respectively). Patients at Nakanuma stage 4 had decreased survival compared with those at stage 1 (P<0.05). The proportion of responders to nonresponders was significantly higher in stages 1–3 PBC than in stage 4 PBC, according to both staging systems (P<0.05 for both). All patients with Scheuer stage 4 PBC were nonresponders, whereas only 28.6% (2/7) of those with Nakanuma stage 4 PBC were responders. Conclusion The Scheuer staging system had greater utility in predicting long-term prognosis and UDCA response than the Nakanuma staging system.


BMC Gastroenterology | 2018

Treatment of long-segment Barrett’s adenocarcinoma by complete circular endoscopic submucosal dissection: a case report

Miki Kaneko; Akira Mitoro; Motoyuki Yoshida; Masayoshi Sawai; Yasushi Okura; Masanori Furukawa; Tadashi Namisaki; Kei Moriya; Takemi Akahane; Hideto Kawaratani; Mitsuteru Kitade; Kousuke Kaji; Hiroaki Takaya; Yasuhiko Sawada; Kenichiro Seki; Shinya Sato; Tomomi Fujii; Junichi Yamao; Chiho Obayashi; Hitoshi Yoshiji

BackgroundWe present the first description of en bloc endoscopic submucosal dissection (ESD) for total circumferential Barrett’s adenocarcinoma, predominantly of the long-segment Barrett’s esophagus (LSBE), with a 2-year follow-up and management strategies for esophageal stricture prevention.Case presentationA 59-year-old man was diagnosed with LSBE and Barrett’s adenocarcinoma by esophagogastroduodenoscopy (EGD). A 55-mm-long circumferential tumor was completely resected by ESD. Histopathology revealed a well-differentiated adenocarcinoma within the LSBE superficial muscularis mucosa. For post-ESD stricture prevention, the patient underwent an endoscopic triamcinolone injection administration, oral prednisolone administration, and preemptive endoscopic balloon dilatation. Two years later, there is no evidence of esophageal stricture or recurrence.ConclusionsESD appears to be a safe, effective option for total circumferential Barrett’s adenocarcinoma in LSBE.


Oncology Letters | 2017

Predisposing factors for hepatocellular carcinoma recurrence following initial remission after transcatheter arterial chemoembolization

Akitoshi Douhara; Tadashi Namisaki; Kei Moriya; Mitsuteru Kitade; Kosuke Kaji; Hideto Kawaratani; Kosuke Takeda; Yasushi Okura; Hiroaki Takaya; Ryuichi Noguchi; Norihisa Nishimura; Kenichiro Seki; Shinya Sato; Yasuhiko Sawada; Junichi Yamao; Akira Mitoro; Masakazu Uejima; Tsuyoshi Mashitani; Naotaka Shimozato; Soichiro Saikawa; Keisuke Nakanishi; Masanori Furukawa; Takuya Kubo; Hitoshi Yoshiji

Hepatocellular carcinoma (HCC) is prone to recurrence following curative treatment. The purpose of the present study was to identify the predisposing factors of HCC recurrence following complete remission achieved by transarterial chemoembolization (TACE). A retrospective cohort study of 70 consecutive patients with HCC who underwent TACE as the initial treatment was conducted. The patients were divided into two groups according to their 1-year disease-free survival (DFS) status; the early recurrence group (ER group; n=32), with HCC recurring within 1 year of initial TACE; and the non-early recurrence group (NER group; n=38), who did not experience recurrence within 1 year. The parameters identified as significantly associated with DFS time on univariate analysis were aspartate aminotransferase (AST), alanine aminotransferase and α-fetoprotein levels, as well as the tumor number (P=0.003, P=0.027, P=0.002 and P=0.005, respectively). Multivariate analysis revealed that AST levels and tumor number were significantly associated with a shorter DFS period (P=0.009 and P=0.038, respectively). The Mantel-Haenszel test revealed a significant trend of decreasing DFS with increasing tumor number. Among the patients with HCC in the ER group, locoregional recurrence occurred more frequently in those who received TACE alone compared with those treated with TACE combined with radiofrequency ablation treatment. In summary, multinodularity of HCC is the most potent predictive factor for the recurrence of HCC within 1 year of initial TACE.


Hepatology Research | 2017

Liver fibrosis progression predicts survival in patients with primary biliary cirrhosis.

Tadashi Namisaki; Kei Moriya; Ryuichi Noguchi; Mitsuteru Kitade; Hideto Kawaratani; Junichi Yamao; Akira Mitoro; Motoyuki Yoshida; Masayoshi Sawai; Masakazu Uejima; Tsuyoshi Mashitani; Kosuke Takeda; Yasushi Okura; Kosuke Kaji; Hiroaki Takaya; Yosuke Aihara; Akitoshi Douhara; Norihisa Nishimura; Yasuhiko Sawada; Shinya Sato; Kenichiro Seki; Hitoshi Yoshiji

The prognosis and natural history of primary biliary cirrhosis (PBC) has improved, and the clinical end‐point for PBC needs to be discovered. We aimed to identify surrogate markers for predicting long‐term prognosis in patients with PBC.


Case Reports in Hepatology | 2017

Severe Aplastic Anemia following Parvovirus B19-Associated Acute Hepatitis

Masanori Furukawa; Kosuke Kaji; Hiroyuki Masuda; Kuniaki Ozaki; Shohei Asada; Aritoshi Koizumi; Takuya Kubo; Norihisa Nishimura; Yasuhiko Sawada; Kosuke Takeda; Tsuyoshi Mashitani; Masayuki Kubo; Itsuto Amano; Tomoyuki Ootani; Chiho Ohbayashi; Koji Murata; Tatsuichi Ann; Akira Mitoro; Hitoshi Yoshiji

Human parvovirus (HPV) B19 is linked to a variety of clinical manifestations, such as erythema infectiosum, nonimmune hydrops fetalis, and transient aplastic anemia. Although a few cases have shown HPVB19 infection as a possible causative agent for hepatitis-associated aplastic anemia (HAAA) in immunocompetent patients, most reported cases of HAAA following transient hepatitis did not have delayed remission. Here we report a rare case of severe aplastic anemia following acute hepatitis with prolonged jaundice due to HPVB19 infection in a previously healthy young male. Clinical laboratory examination assessed marked liver injury and jaundice as well as peripheral pancytopenia, and bone marrow biopsy revealed severe hypoplasia and fatty replacement. HPVB19 infection was diagnosed by enzyme immunoassay with high titer of anti-HPVB19 immunoglobulin M antibodies. Immunosuppressive therapy was initiated 2 months after the onset of acute hepatitis when liver injury and jaundice were improved. Cyclosporine provided partial remission after 2 months of medication without bone marrow transplantation. Our case suggests that HPVB19 should be considered as a hepatotropic virus and a cause of acquired aplastic anemia, including HAAA.


United European gastroenterology journal | 2018

von Willebrand factor is a useful biomarker for liver fibrosis and prediction of hepatocellular carcinoma development in patients with hepatitis B and C

Hiroaki Takaya; Hideto Kawaratani; Yuki Tsuji; Keisuke Nakanishi; Soichiro Saikawa; Shinya Sato; Yasuhiko Sawada; Kosuke Kaji; Yasushi Okura; Naotaka Shimozato; Mitsuteru Kitade; Takemi Akahane; Kei Moriya; Tadashi Namisaki; Akira Mitoro; Masanori Matsumoto; Hiroshi Fukui; Hitoshi Yoshiji

Background Several noninvasive biomarkers are available for diagnosing liver fibrosis stage and predicting hepatocellular carcinoma (HCC) development in patients with chronic hepatitis and liver cirrhosis. However, these biomarkers are not sufficiently accurate. Recently, von Willebrand factor (VWF) has been related to angiogenesis and apoptosis. Furthermore, VWF is associated with hepatic spare ability and HCC. Objective We aimed to determine whether VWF is a potential biomarker for liver fibrosis and HCC development. Methods Two hundred and twelve patients with chronic hepatitis B and C were recruited. VWF antigen (VWF: Ag) levels in each patient were determined via enzyme-linked immunosorbent assay. Univariable and multivariable analyses were used to determine the risk factor of HCC. Results The VWF: Ag levels were higher in patients with severe liver fibrosis stage and/or HCC development than in those without. The area under the curve of VWF: Ag for diagnosis of severe liver fibrosis stage was 0.721. Multivariable analysis showed that only VWF: Ag was a predictive biomarker for HCC development. Conclusions VWF: Ag is related to liver fibrosis and may be useful for predicting HCC development. VWF is a potentially useful biomarker to diagnose severe liver fibrosis and predict HCC development.


Oncotarget | 2018

Oral administration of fructose exacerbates liver fibrosis and hepatocarcinogenesis via increased intestinal permeability in a rat steatohepatitis model

Kenichiro Seki; Mitsuteru Kitade; Norihisa Nishimura; Kosuke Kaji; Kiyoshi Asada; Tadashi Namisaki; Kei Moriya; Hideto Kawaratani; Yasushi Okura; Hiroaki Takaya; Yasuhiko Sawada; Shinya Sato; Keisuke Nakanishi; Hitoshi Yoshiji

Recent reports have revealed the impact of a western diet containing large amounts of fructose on the pathogenesis of non-alcoholic steatohepatitis (NASH). Fructose exacerbates hepatic inflammation in NASH by inducing increasing intestinal permeability. However, it is not clear whether fructose contributes to the progression of liver fibrosis and hepatocarcinogenesis in NASH. The aim of this study was to investigate the effect of fructose intake on NASH in a rat model. A choline-deficient/L-amino acid diet was fed to F344 rats to induce NASH. Fructose was administrated to one group in the drinking water. The development of liver fibrosis and hepatocarcinogenesis were evaluated histologically. Oral fructose administration exacerbated liver fibrosis and increased the number of preneoplastic lesions positive for glutathione S-transferase placental form. Fructose-treated rats had significantly higher expression of hepatic genes related to toll-like receptor-signaling, suggesting that fructose consumption increased signaling in this pathway, leading to the progression of NASH. We confirmed that intestinal permeability was significantly higher in fructose-treated rats, as evidenced by a loss of intestinal tight junction proteins. Fructose exacerbated both liver fibrosis and hepatocarcinogenesis by increasing intestinal permeability. This observation strongly supports the role of endotoxin in the progression of NASH.

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Kei Moriya

Nara Medical University

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Akira Mitoro

Nara Medical University

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Kosuke Kaji

Nara Medical University

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