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Dive into the research topics where Yasuo Arakawa is active.

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Featured researches published by Yasuo Arakawa.


Alimentary Pharmacology & Therapeutics | 2004

Randomized placebo-controlled trial assessing the effect of bifidobacteria-fermented milk on active ulcerative colitis

Kimitoshi Kato; Shigeaki Mizuno; Yoshinori Umesaki; Yukimoto Ishii; Masahiko Sugitani; Akemi Imaoka; M. Otsuka; Osamu Hasunuma; Ryuichi Kurihara; Ariyoshi Iwasaki; Yasuo Arakawa

Background : Probiotics are efficacious for treating and maintaining remission of ulcerative colitis.


Intervirology | 2008

Influence of occult hepatitis B virus coinfection on the incidence of fibrosis and hepatocellular carcinoma in chronic hepatitis C.

Shunichi Matsuoka; Kazushige Nirei; Akinori Tamura; Hitomi Nakamura; Hiroshi Matsumura; Shuu Oshiro; Yasuo Arakawa; Hiroaki Yamagami; Naohide Tanaka; Mitsuhiko Moriyama

We examined prospectively the influence of occult hepatitis B virus (HBV) infection on the histopathological features and clinical outcome of HCV RNA-positive chronic hepatitis (CH-C) and detected hepatitis B core (HBc) particles in hepatocytes. The subjects were 468 patients with CH-C or liver cirrhosis (LC) who were negative for serum hepatitis B surface antigen (HBsAg) by enzyme-linked immunosorbent assay. HBV DNA was detected in serum by nested PCR. HBsAg and HBc antigen (HBcAg) in liver were investigated using immunohistochemical techniques and light (LM) and electron microscopy (EM). Serum HBV DNA was detected in 43.6% of the patients studied. There were no significant differences between HBV DNA-positive and DNA-negative patients in terms of their clinical profiles. For HBV DNA-positive patients, the degree of inflammatory cell infiltration and irregular regeneration of hepatocytes was significantly greater than for HBV DNA-negative patients. The cumulative probability of development of hepatocellular carcinoma (HCC) was significantly higher for HBV DNA-positive patients than for HBV DNA-negative patients. HBV DNA positivity was a risk factor for the occurrence of HCC according to multivariate analysis. HBsAg and HBcAg were detected in 8.5 and 72.3%, respectively, of the livers of serum HBV DNA-positive individuals. Core particles were detected in the nuclei of the hepatocytes by IEM. The histopathological features and long-term outcome of CH-C or LC could be affected by occult HBV infection.


Alimentary Pharmacology & Therapeutics | 2002

Circadian rhythm of melatonin and prostaglandin in modulation of stress-induced gastric mucosal lesions in rats.

Kimitoshi Kato; Ichiro Murai; Satoshi Asai; Yasuo Takahashi; Toshihito Nagata; Sachiko Komuro; Shigeaki Mizuno; Ariyoshi Iwasaki; Kouichi Ishikawa; Yasuo Arakawa

We previously demonstrated the circadian variation of water‐immersion restraint stress (WRS)‐induced gastric mucosal lesions in rats.


Digestive Diseases and Sciences | 2006

Clinical Significance of Evaluation of Serum Zinc Concentrations in C-Viral Chronic Liver Disease

Mitsuhiko Moriyama; Hiroshi Matsumura; Akiko Fukushima; Kenji Ohkido; Yasuo Arakawa; Kazushige Nirei; Hiroaki Yamagami; Miki Kaneko; Naohide Tanaka; Yasuyuki Arakawa

We evaluated zinc concentrations in patients with hepatitis C virus (HCV)-positive chronic liver disease and correlated them with the clinical profiles of the patients. A total of 100 patients with chronic hepatitis (CH), 29 with liver cirrhosis (LC), and 6 who were asymptomatic HCV carriers (ASC) were examined. All of the patients were positive for serum HCV RNA. One hundred eighteen HCV antibody-positive hepatocellear carcinoma (HCC) patients and 11 healthy subjects also were included in this study. Serum zinc concentrations were evaluated using conventional atomic absorption spectrometry. The median concentration of zinc in patients with CH was statistically lower than that in healthy control subjects. The median zinc concentrations of the LC and HCC groups were significantly lower than that of the CH group. A significant correlation was observed between the zinc concentrations and the platelet counts and albumin concentrations. The zinc concentrations did not correlate with tumor size and number and decreased with the development of Child-Pugh stage. The cumulative survival rate after therapy for HCC nodules in the low zinc concentration group was significantly lower than in the high group. We conclude that the serum concentration of zinc influences the clinical profiles in patients with C-viral chronic liver disease.


Alimentary Pharmacology & Therapeutics | 2000

Gastric epithelial cell proliferation and apoptosis in Helicobacter pylori-infected mice

Toshikazu Yamaguchi; Noriko Nakajima; H. Kuwayama; Yoko Ito; Ariyoshi Iwasaki; Yasuo Arakawa

Background: Helicobacter pylori causes gastritis and is strongly associated with gastroduodenal ulcer and gastric cancer. The bacterium is associated with an increased rate of epithelial proliferation, which can be reversed by eradication of the organism. The mechanism of this response is not known, but this epithelial proliferation is one of the risk factors for developing gastric carcinoma. Recently, apoptosis also was found to be increased in the gastric mucosa of persons carrying H. pylori.


Journal of Gastroenterology | 2004

PBC-AIH overlap syndrome with concomitant ITP and Hashimoto's disease with positivity for anti-centromere antibody.

Yasuo Arakawa; Shuichi Amaki; Hiroshi Miyakawa; Toshimitsu Sakai; Iori Gotou; Naohide Tanaka; Mitsuhiko Moriyama; Ariyoshi Iwasaki; Masahiko Sugitani; Yasuyuki Arakawa

We report a case of primary biliary cirrhosis (PBC)-autoimmune hepatitis (AIH) overlap syndrome with concurrent idiopathic thrombocytopenic purpura (ITP) and Hashimoto’s disease with positivity for anticentromere antibody. The patient was a 64-year-old woman with symptoms of jaundice and general fatigue. About 30 years earlier, she had been diagnosed as having ITP and had undergone splenectomy. As part of her present history, she had exhibited liver dysfunction in 1995, during the follow-up of Hashimoto’s disease, and a liver biopsy led to the diagnosis of PBC. In March 2000, she was admitted to hospital because of general fatigue and jaundice. Blood tests revealed: total protein (TP), 6.6 g/dl; γ-globulin (glb), 35.9%; total bilirubin (T-bil), 9.41 mg/dl; direct bilirubin (D-bil), 7.52 mg/dl; aspartate aminotransferase (AST), 957 U/l; alanine aminotransferase (ALT), 651 U/l; alkaline phosphatase (ALP), 595 U/l; γ-guanosine triphosphate (GTP), 129 U/l; IgG, 2620 mg/dl; IgM, 223 mg/dl; hepatitis B surface antigen (HBsAg), negative; anti-hepatitis C virus (HCV), negative; antinuclear antibody, positive; antimitchondrial antibody (AMA), negative (by the immunofluorescence [IF] method); and anti-pyruvate dehydrogenase complex (PDC)-E2 antibody, positive (by Western blotting). Anticentromere antibody (ACA), which is an alternative diagnostic marker for PBC, was detected in this patient. Prednisolone was administered after admission and liver function test results improved markedly. The liver biopsy in 1995 had revealed infiltration of lymphocytes and plasma cells in the portal areas with fibrous expansion and periportal necrosis. Destructive cholangitis was observed, as well as scattered epitheloid cell granulomas in some portal areas. Liver biopsy after the steroid treatment revealed alleviated necrotic inflammatory responses of hepatocytes, while the destructive cholangitis persisted. This is a very rare case of PBC-AIH overlap syndrome accompanied by ITP and Hashimoto’s disease which provides a possible insight into the mechanisms and interplay of autoimmune diseases.


Journal of Clinical Biochemistry and Nutrition | 2012

Zinc supplementation therapy improves the outcome of patients with chronic hepatitis C.

Hiroshi Matsumura; Kazushige Nirei; Hitomi Nakamura; Yasuo Arakawa; Teruhisa Higuchi; Jyunpei Hayashi; Hiroaki Yamagami; Syunichi Matsuoka; Masahiro Ogawa; Noriko Nakajima; Naohide Tanaka; Mitsuhiko Moriyama

We administered zinc supplementation therapy over three years to patients with chronic hepatitis C and reported and that the aspartate aminotransferase (AST) and alanine aminotaransferase (ALT) levels decreased, and platelet counts increased, significantly in the group with increased serum zinc concentrations. We are continuing this treatment to clarify the long-term consequences and report here the changes in serum zinc concentrations over seven years and compare the cumulative incidence of hepatocellular carcinoma (HCC). We administered polaprezinc to 32 patients, randomly selected for zinc therapy (treatment group), while another 30 formed the control group. We measured the serum zinc and albumin concentrations and conducted a prospective study to determine long-term outcomes. The changes and rates of change of serum zinc concentrations after seven years were 76.7 ± 18.2 µg/dl and +0.302 ± 0.30% in the treatment group and 56.7 ± 12.4 µg/dl and +0.033 ± 0.21% in the control group and had increased significantly (p = 0.0002, p = 0.0036). Progression of liver disease seemed to vary, depending on serum albumin concentrations. In the group with baseline serum albumin concentrations of 4.0 g/dl or more, the change and rate of change of serum zinc concentrations increased significantly, and the cumulative incidence of HCC tended to decrease, in the treated group. According to multivariate analysis, the factors that contribute to a reduction in the incidence of HCC are zinc therapy (risk ratio: 0.113, 95% CI: 0.015–0.870, p = 0.0362), and platelet counts (0.766, 0.594–0.989, 0.0409). Zinc supplementation therapy seems to improve liver pathology and reduce the incidence of HCC.


Intervirology | 2006

Measurement of human intercellular adhesion molecule 1 in the blood is useful for predicting the occurrence of hepatocellular carcinomas from chronic hepatitis C and liver cirrhosis.

Mitsuhiko Moriyama; Hiroshi Matsumura; Jiro Shioda; Hiroshi Aoki; Hitomi Nakamura; Yasuo Arakawa; Kazushige Nirei; Hiroaki Yamagami; Miki Kaneko; Naohide Tanaka; Yasuyuki Arakawa

Objective: We measured the concentrations of serum intercellular adhesion molecule 1 (sICAM-1) in patients with C-viral chronic liver diseases and started prospective studies immediately thereafter, in order to determine whether the concentration of sICAM-1 is useful for predicting the occurrence of hepatocellular carcinoma (HCC) following C-viral chronic hepatitis (CH) and liver cirrhosis (LC). Methods: We studied 74 patients with CH, 18 with LC, and 28 patients with HCC who visited our institute from 1993 through 1996. All were positive for hepatitis C virus RNA in the blood. The concentrations of sICAM-1 were measured using enzyme-linked immunosorbent assay kits. The expression of ICAM-1 in the liver was detected by indirect immunoperoxidase staining. Results: The concentrations of sICAM-1 were significantly higher in patients with LC and HCC than in patients with CH. The sICAM-1 concentrations were high in patients whose platelet counts were low. ICAM-1 in the liver was localized to the endoplasmic reticulum or the membrane of cancer cells. The cumulative rate of occurrence of HCC from CH or LC was significantly higher in the high-sICAM-1 group (>400 ng/ml) than in the low-sICAM-1 group. Multivariate analysis revealed that elevation of the sICAM-1 concentration is a significant risk factor for the occurrence of HCC. Conclusion: Evaluation of the sICAM-1 concentration is useful for prediction of the occurrence of HCC in patients with C-viral CH or LC.


Journal of International Medical Research | 1997

Efficacy of Lansoprazole against Peptic Ulcers Induced by Nonsteroidal Anti-Inflammatory Drugs: Endoscopic Evaluation of Ulcer Healing

Yoshihiro Matsukawa; Yasuyuki Tomita; Susumu Nishinarita; Takashi Horie; Kimitoshi Kato; Yasuo Arakawa; K Ko; H Shimada; M Nakano; Y Kitami; H Kurosaka

Beyond the obvious step of limiting use of non-steroidal anti-inflammatory drugs (NSAIDs), the treatment of ulcers induced by NSAIDs remains controversial. We evaluated the efficacy of the proton-pump inhibitor lansoprazole on NSAID-induced ulcers. Ulcers were endoscopically diagnosed in 47 NSAID users. These patients received 30 mg/day lansoprazole, orally, for 6 or 8 weeks (6 weeks for duodenal ulcers and 8 weeks for other ulcers). Ulcer healing was assessed using an established classification system. The presence of immunoglobulin G antibody against Helicobacter pylori was also evaluated. The antibody was present in the sera of 51% of patients (24/47). Most of the ulcers reached scarring stages S1 (healing) or S2 (good healing), and the S2 healing rate was 35%. Two H. pylori seropositive patients did not reach these stages; their ulcers were improved by H. pylori eradication therapy, followed, in one case, by medication with misoprostol. Lansoprazole seemed to be useful for most patients with NSAID-induced ulcers, but a few needed additional treatments.


Annals of Tropical Medicine and Parasitology | 2009

Sero-epidemiology of sporadic acute hepatitis in Bangladesh: high prevalences of infection with type-B, type-E and multiple types of hepatitis virus

Masahiko Sugitani; Aleemuzzaman Sheikh; Koyu Suzuki; Noriko Kinukawa; Mitsuhiko Moriyama; Yasuo Arakawa; Kazuo Komiyama; Tian-Cheng Li; Naokazu Takeda; Shamsuddin M. Ishaque; Pk Roy; Asma Raihan; Mahmud Hasan

Abstract In a recent investigation of hepatitis in Bangladesh, the sera from 74 adult patients (aged 15–67 years) who had been clinically diagnosed as cases of sporadic acute hepatitis were collected at various hospitals in and around Dhaka. Five cases were positive for IgM antibody against the hepatitis A virus and 30 were positive both for the surface antigen of the hepatitis B virus (HBV) and for IgM antibody against the HBV core (HBc). The six cases found positive for antibodies against the hepatitis D virus were all also positive for the HBV surface antigen but negative for anti-HBc IgM. Thirteen patients harboured hepatitis C virus RNA and 29 were positive for IgM antibody against the hepatitis E virus (HEV). There were 14 non-A-to-E subjects, whose illness was of unknown aetiology. Of the 83 infections with hepatitis viruses detected in the other 60 patients, 6%, 36%, 16%, 7% and 35% were of types A, B, C, D and E, respectively. Each of 28 of the patients (47% of those confirmed to have viral hepatitis) had concomitant infection with more than one type of hepatitis virus. The predominance of HBV and HEV infections and the high prevalence of multiple infection seen among these Bangladeshi cases have not been observed among hepatitis cases in developed countries.

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