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Dive into the research topics where Chiaki Okuse is active.

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Featured researches published by Chiaki Okuse.


Journal of Clinical Microbiology | 2009

Distribution of Hepatitis B Virus Genotypes among Patients with Chronic Infection in Japan Shifting toward an Increase of Genotype A

Kentaro Matsuura; Yasuhito Tanaka; Shuhei Hige; Gotaro Yamada; Yoshikazu Murawaki; Masafumi Komatsu; Tomoyuki Kuramitsu; Sumio Kawata; Eiji Tanaka; Namiki Izumi; Chiaki Okuse; Shinichi Kakumu; Takeshi Okanoue; Keisuke Hino; Yoichi Hiasa; Michio Sata; Tatsuji Maeshiro; Fuminaka Sugauchi; Shunsuke Nojiri; Takashi Joh; Yuzo Miyakawa; Masashi Mizokami

ABSTRACT Acute hepatitis B virus (HBV) infection has been increasing through promiscuous sexual contacts, and HBV genotype A (HBV/A) is frequent in patients with acute hepatitis B (AHB) in Japan. To compare the geographic distribution of HBV genotypes in patients with chronic hepatitis B (CHB) in Japan between 2005 and 2006 and between 2000 and 2001, with special attention to changes in the proportion of HBV/A, a cohort study was performed to survey changes in genotypes of CHB patients at 16 hospitals throughout Japan. Furthermore, we investigated the clinical characteristics of each genotype and examined the genomic characteristics of HBV/A isolates by molecular evolutionary analyses. Of the 1,271 patients, 3.5%, 14.1%, and 82.3% were infected with HBV/A, -B, and -C, respectively. In comparison with our previous survey during 2000 and 2001, HBV/A was twice as frequent (3.5% versus 1.7%; P = 0.02). The mean age was lower in the patients with HBV/A than in those with HBV/B or -C. Based on phylogenetic analyses of 11 full-length genomes and 29 pre-S2/S region sequences from patients, HBV/A isolates were imported from Europe and the United States, as well as the Philippines and India. They clustered with HBV/A from AHB patients and have spread throughout Japan. HBV/A has been increasing in CHB patients in Japan as a consequence of AHB spreading in the younger generation through promiscuous sexual contacts, aided by a tendency of HBV/A to induce chronic hepatitis. The spread of HBV/A infection in Japan should be prevented by universal vaccination programs.


Hepatology Research | 2014

Tolvaptan for improvement of hepatic edema: A phase 3, multicenter, randomized, double‐blind, placebo‐controlled trial

Isao Sakaida; Seiji Kawazoe; Kozo Kajimura; Takafumi Saito; Chiaki Okuse; Koichi Takaguchi; Mitsuru Okada; Kiwamu Okita

Hepatic edema is manifested by ascites, lower limb edema and intolerable symptoms. Some patients insufficiently respond to the conventional diuretic therapy. Therefore, a novel therapeutic option is required. We conducted a phase 3 study to confirm therapeutic effect of tolvaptan on hepatic edema associated with liver cirrhosis.


Hepatology Research | 2011

Higher discontinuation and lower survival rates are likely in elderly Japanese patients with advanced hepatocellular carcinoma receiving sorafenib

Manabu Morimoto; Kazushi Numata; Masaaki Kondo; Hisashi Hidaka; Juichi Takada; Akitaka Shibuya; Satoshi Kobayashi; Shinichi Ohkawa; Chiaki Okuse; Satoshi Morita; Masataka Taguri; Katsuaki Tanaka

Aim:  Sorafenib is approved for the treatment of advanced hepatocellular carcinoma (HCC) in Japan; however, its tolerability and efficacy in elderly patients with HCC have not been clarified. We aimed to evaluate the tolerability and efficacy of sorafenib with increasing age.


Clinical Nephrology | 2006

Successful treatment of hepatitis B virus-associated membranous nephropathy with lamivudine

Chiaki Okuse; Hiroshi Yotsuyanagi; Yamada N; Hiroshi Ikeda; Hideaki Takahashi; Michihiro Suzuki; Kondo S; Kimura K; Koike J; Fumio Itoh

We present a case of chronic hepatitis B with membranous nephropathy, that was improved by lamivudine treatment. A 37-year-old man was admitted to our hospital for the evaluation of proteinuria. He was diagnosed as having chronic glomerulonephritis associated with chronic hepatitis B. Histopathological findings of the renal biopsy specimen indicated membranous nephropathy. He suffered from nephrotic syndrome associated with leg edema, which was parallel to the exacerbation of hepatitis. Lamivudine was started for the treatment of hepatitis, which caused the disappearance of serum hepatitis B virus DNA and the normalization of ALT level in 4 weeks. Additionally, proteinuria disappeared 120 weeks after the treatment was started. Lamivudine treatment may remit HBV-associated nephropathy.


Hepatology Research | 2009

Short‐term prolongation of pegylated interferon and ribavirin therapy for genotype 1b chronic hepatitis C patients with early viral response

Hiroki Ikeda; Michihiro Suzuki; Chiaki Okuse; Norie Yamada; Masaru Okamoto; Minoru Kobayashi; Yoshihiko Nagase; Hideaki Takahashi; Koutarou Matsunaga; Nobuyuki Matsumoto; Fumio Itoh; Hiroshi Yotsuyanagi; Yu Koitabashi; Kiyomi Yasuda; Shiro Iino

Aim:  We tailored extended treatments using pegylated interferon (PEG IFN) and ribavirin (RBV) to viral responses after initiation of therapy and investigated the efficacy and safety of its therapy for chronic hepatitis C (CHC) patients.


Journal of Gastroenterology | 2007

Hepatitis C as a systemic disease: virus and host immunologic responses underlie hepatic and extrahepatic manifestations

Chiaki Okuse; Hiroshi Yotsuyanagi; Kazuhiko Koike

Hepatitis C virus (HCV) causes liver diseases. Approximately 2 million people in Japan and approximately 170 million people worldwide are infected with HCV, and they often suffer from chronic hepatitis, followed by hepatic cirrhosis, leading to hepatic cancer. It was determined relatively soon after the discovery of HCV that HCV infection does not involve the liver only. Other than hepatitis, many complicating diseases of the organs and tissues other than the liver, referred to as extrahepatic lesions, occur in association with HCV infection (Table 1). This review provides an overview of typical extrahepatic lesions associated with hepatitis C.


Hepatology Research | 2003

Detection, using a novel method, of a high prevalence of cryoglobulinemia in persistent hepatitis C virus infection

Chiaki Okuse; Hiroshi Yotsuyanagi; Toshio Okazaki; Kiyomi Yasuda; Takahiro Fujioka; Masai Tomoe; Kiyoe Hashizume; Takeshi Hayashi; Michihiro Suzuki; Shogo Iwabuchi; Tatsuo Nagai; Shiro Iino

To elucidate precisely the prevalence and significance of cryoglobulinemia in hepatitis C, we examined the prevalence of serum cryoglobulin (CG) among 232 consecutive hepatitis C virus carriers (23 asymptomatic carriers, 164 with chronic hepatitis, 45 with cirrhosis), 30 consecutive hepatitis B virus carriers and 100 age- and sex-matched healthy volunteers. We used a gel-diffusion procedure that detects CG with greater sensitivity and specificity than the conventional precipitation method. Among the 232 patients, 166 were tested for the presence or absence of CG by the precipitation method also, which showed 60 (36.1%) patients to be positive for CG. On the other hand, 164 of the 232 patients (70.7%) were positive for CG using the diffusion method. 5 (16.7%) of the 30 HBV carriers and 2 (2%) of the healthy volunteers also were positive for CG using the gel-diffusion procedure. CG was detected more frequently among the patients with chronic hepatitis or cirrhosis than the asymptomatic carriers. In spite of the high prevalence of CG positivity, only one patient had symptoms related to cryoglobulinemia. Positivity for CG was not related to viral serogroup, viral load or the presence of antinuclear antibody, but it was related closely to CH50: 58 of 63 (92.1%) patients with lower levels of CH50 were positive for serum CG. In conclusion, cryoglobulinemia is a very common feature of chronic hepatitis C.


Journal of Gastroenterology | 2012

Pathophysiological analysis of nonalcoholic fatty liver disease by evaluation of fatty liver changes and blood flow using xenon computed tomography: can early-stage nonalcoholic steatohepatitis be distinguished from simple steatosis?

Ryuta Shigefuku; Hideaki Takahashi; Minoru Kobayashi; Hiroki Ikeda; Kotaro Matsunaga; Chiaki Okuse; Nobuyuki Matsumoto; Shiro Maeyama; Shigeru Sase; Michihiro Suzuki; Fumio Itoh

IntroductionEffective noninvasive tests that can distinguish early-stage nonalcoholic steatohepatitis (NASH) from simple steatosis (SS) have long been sought. Our aim was to determine the possibility of noninvasively distinguishing early-stage NASH from SS.Materials and methodsWe used Fick’s principle and the Kety–Schmidt equation to determine the hepatic tissue blood flow (TBF) in 65 NASH patients who underwent xenon computed tomography (Xe-CT). We calculated the lambda value (LV), i.e., Xe gas solubility coefficient, in liver and blood. We assessed the histological severity of fatty changes and fibrosis on the basis of Brunt’s classification. Liver biopsy revealed SS in 9 patients and NASH in 56 patients. NASH stages 1 and 2 were classified as early-stage NASH (Ea-NASH; 38 patients) and stages 3 and 4 as advanced-stage NASH (Ad-NASH; 18 patients). We evaluated the differences in LV and TBF among the 3 groups.ResultsLV was significantly lower in the Ad-NASH group than in the SS and Ea-NASH groups. Portal venous TBF (PVTBF) was significantly lower in the Ea-NASH group than in the SS group, and PVTBF was lower in the Ad-NASH group than in the Ea-NASH group. Total hepatic TBF (THTBF) was significantly different between the SS and Ea-NASH groups and between the SS and Ad-NASH groups.ConclusionsIn conclusion, measurements of TBF and LV are useful for evaluating the pathophysiological progression of NASH. In addition, these measurements can facilitate the differential diagnosis of SS and Ea-NASH, which may not be distinguishable by other means.


Clinical Infectious Diseases | 2013

High Levels of Hepatitis B Virus After the Onset of Disease Lead to Chronic Infection in Patients With Acute Hepatitis B

Hiroshi Yotsuyanagi; Kiyoaki Ito; Norie Yamada; Hideaki Takahashi; Chiaki Okuse; Kiyomi Yasuda; Michihiro Suzuki; Kyoji Moriya; Masashi Mizokami; Yuzo Miyakawa; Kazuhiko Koike

BACKGROUND Some patients with acute hepatitis B virus (HBV) infection develop chronic infection. However, the method for identifying these patients has not been established. METHODS We followed 215 Japanese patients with acute HBV infection until the clearance of hepatitis B surface antigen (HBsAg) or the development of chronic infection. Levels of HBsAg and HBV DNA were serially monitored from the onset. RESULTS Of the 215 patients, 113 (52.5%) possessed HBV genotype A, 26 (12.0%) genotype B, and 73 (34.0%) genotype C. Twenty-one of the 215 (9.8%) developed chronic infection, with the persistence of HBsAg for >6 months. The rate of chronicity of genotype A, B, and C was 12.4%, 3.8%, and 8.2%. Of the 21 patients, only 6 (2.8%) patients, including 5 with genotype A, failed to clear HBsAg within 12 months. Levels of HBsAg at 12 weeks and HBV DNA at 4 weeks were useful for distinguishing the patients who became chronic from those who did not (P < .001 and P < .001, respectively). Likewise, the levels of HBsAg at 12 weeks and HBV DNA at 8 weeks were useful for discriminating between the patients who lost HBsAg within 12 months and those who did not (P < .01 and P < .05, respectively). CONCLUSIONS In acute HBV infection, clearance of HBV may happen between 6 and 12 months from the onset. Only those who fail to clear HBV within 12 months from the onset may develop chronic infection.


Hepatology Research | 2015

Field practice study of half-dose sorafenib treatment on safety and efficacy for hepatocellular carcinoma: A propensity score analysis

Manabu Morimoto; Kazushi Numata; Masaaki Kondo; Satoshi Kobayashi; Shinichi Ohkawa; Hisashi Hidaka; Takahide Nakazawa; Yusuke Okuwaki; Chiaki Okuse; Kotaro Matsunaga; Michihiro Suzuki; Satoshi Morita; Masataka Taguri; Katsuaki Tanaka

Patients with hepatocellular carcinoma (HCC) who receive an initial full dose of sorafenib (800 mg/day) often require a decreased dose (400 mg/day) or discontinuation of therapy because of severe adverse events. We conducted a retrospective analysis of patients with HCC to compare the safety and efficacy of full‐ to half‐dose sorafenib.

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Michihiro Suzuki

St. Marianna University School of Medicine

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Fumio Itoh

St. Marianna University School of Medicine

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Nobuyuki Matsumoto

St. Marianna University School of Medicine

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Hiroki Ikeda

St. Marianna University School of Medicine

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Kotaro Matsunaga

St. Marianna University School of Medicine

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Hideaki Takahashi

St. Marianna University School of Medicine

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Ryuta Shigefuku

St. Marianna University School of Medicine

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Toshiya Ishii

St. Marianna University School of Medicine

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Kazunari Nakahara

St. Marianna University School of Medicine

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