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Dive into the research topics where Hitoshi Ohkubo is active.

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Featured researches published by Hitoshi Ohkubo.


Journal of Hepatology | 1997

Quantitative assays for hepatitis C virus in serum as predictors of the long-term response to interferon

Yasushi Shiratori; Naoya Kato; Osamu Yokosuka; Etsuko Hashimoto; Naoaki Hayashi; Akira Nakamura; Manabu Asada; Hisamoto Kuroda; Hitoshi Ohkubo; Yasuyuki Arakawa; Akisuke Iwama; Masao Omata

BACKGROUND/AIMS Interferon therapy has a beneficial effect in patients with chronic hepatitis C who have a low viral load. The aim of this study was to compare the core protein level with HCV RNA levels and to analyze whether virus quantitation predicts the efficacy of interferon therapy. METHODS HCV core protein level assessed by the recently developed assay was compared with HCV RNA levels measured by three different methods (Amplicor-HCV monitor, competitive RT(CRT)-PCR, and bDNA probe assay) in 352 patients with chronic hepatitis C in relation to viral serotype. RESULTS From 91% (320/352) to 93% (299/322) of patients with viremia were detected by Amplicor-monitor and CRT-PCR, in contrast to 60% (187/312) and 74% (191/258) by bDNA and HCV core protein assay, respectively. The HCV core protein level was positively correlated with HCV RNA levels measured by the three assays (r = 0.680 to 0.731). Serum HCV RNA and core protein levels were significantly lower in patients with serotype 2 than in those with serotype 1. Viral eradication after interferon therapy was observed in 60-70% of the patients with < 1 x 10(4) copies/ml of HCV RNA by Amplicor-monitor assay, < 2 x 10(5) copies/ml by CRT-PCR, < 0.5 Meq/ml by bDNA assay, and < 20 pg/ml of core protein by HCV core protein assay. Viral eradication was uncommon (< 11%) among the patients with higher viral loads. Bivariate analysis revealed that the outcome of interferon therapy was more closely associated with both HCV core protein and RNA levels than the HCV serotype. CONCLUSIONS Quantitation of HCV core protein and HCV RNA in useful for prediction of the interferon response.


European Neurology | 2002

Alterations of Quantitative EEG and Mini-Mental State Examination in Interferon-α-Treated Hepatitis C

Satoshi Kamei; T. Sakai; Masato Matsuura; Naohide Tanaka; Takuya Kojima; Yasuyuki Arakawa; Yoshihiro Matsukawa; Tomohiko Mizutani; K. Oga; Hitoshi Ohkubo; H. Matsumura; Kaname Hirayanagi

We have recently observed a diffuse slowing of brain waves using serial quantitative electroencephalographic (qEEG) examinations in interferon (IFN)-α-treated chronic hepatitis C patients. However, it remains unclear how this alteration could be assessed. We evaluated the correlation between the qEEG changes and three tests of mental status, including the Mini-Mental State Examination (MMSE), in such patients. This is the first study to undertake a clinical evaluation of the adverse effects on brain function due to IFN. We undertook blind, prospective and serial qEEG examinations on 56 chronic hepatitis C patients at three independent hospitals. IFN-α was administered intramuscularly at a dose of 9 × 106 IU daily for the first 4 weeks and then 3 times/week for the next 20 weeks. Serial EEGs were obtained before, at 2 and 4 weeks of treatment, and after the IFN-α treatment. The absolute power values of each frequency band in each patient at different stages of treatment were recorded by qEEG. Each patient was assessed by the MMSE, Hamilton Rating Scale for Depression (HSD), and Hamilton Rating Scale for Anxiety (HSA). We statistically evaluated the correlations between the changes in power values and alterations of scores on the mental status tests during IFN-α treatment. The decreased scores observed on the MMSE ranged from 2 to 5 points at both 2 and 4 weeks of IFN-α treatment. There were no significant differences in age distribution for each decreased score on the MMSE. As the alteration in MMSE score during IFN treatment increased, the alteration in absolute power values for the slow waves during IFN treatment increased significantly, while that for the alpha 2 and fast waves during treatment decreased significantly. However, the changes in the HDS and HSA revealed no significant correlations. The alteration of the qEEG was reversible after the treatment. MMSE scores represent one screening method for the clinical assessment of IFN-α-induced alterations of brain function.


International Hepatology Communications | 1993

Ultrastructural study of HBx antigen in liver from chronic hepatitis B patients

Mitsuhiko Moriyama; Kazutomo Suzuki; Shuichi Amaki; Naohide Tanaka; Hitoshi Ohkubo; Ishizuka Hideo; Yasuyuki Arakawa; Yutaka Matsuo; Kohyu Suzuki; Toshikazu Uchida; Toshio Shikata; Noboru Yanaihara

Abstract We examined the localization of intrahepatic HBx and HBc antigen in patients with chronic hepatitis B using immuno-electron microscopy. HBx antigen is detected on endoplasmic reticulum in the cytoplasm of hepatocytes, and is localized at almost the same site as the HBc antigen. These studies suggested that HBx antigen appears to be associated with HBV replication in one way or another.


Internal Medicine | 1999

Prediction of the Development of Hepato-Cellular-Carcinoma in Patients with Liver Cirrhosis by the Serial Determinations of Serum Alpha-L-fucosidase Activity

Hideo Ishizuka; Tomoki Nakayama; Shunichi Matsuoka; Iori Gotoh; Masahiro Ogawa; Kazutomo Suzuki; Naohide Tanaka; Kouji Tsubaki; Hitoshi Ohkubo; Yasuyuki Arakawa; Tadao Okano


Journal of Clinical Neurophysiology | 2005

Correlation Between Quantitative-EEG Alterations and Age in Patients With Interferon-?????Treated Hepatitis C

Satoshi Kamei; Kentaro Oga; Masato Matsuura; Naohide Tanaka; Takuya Kojima; Yasuyuki Arakawa; Yoshihiro Matsukawa; Tomohiko Mizutani; Teiichiro Sakai; Hitoshi Ohkubo; Hiroshi Matsumura; Mitsuhiko Moriyama; Kaname Hirayanagi


Liver | 2000

A prospective study of interferon therapy modified by pre‐treatment viral load in cirrhotic patients

Yasushi Shiratori; Mistuhiko Moriyama; Fumio Imazeki; Hitoshi Ohkubo; Naohide Tanaka; Yasuyuki Arakawa; Haruhiko Yoshida; Osamu Yokosuka; Akitaka Shibuya; Kohei Matsuzaki; Etsuko Hashimoto; Naoaki Hayashi; Keiichi Hirata; Yasuo Ohashi; Masao Omata


Internal Medicine | 2009

Relationships between Quantitative Electroencephalographic Alterations and the Severity of Hepatitis C Based on Liver Biopsy in Interferon-α Treated Patients

Satoshi Kamei; Akihiko Morita; Naohide Tanaka; Masato Matsuura; Mitsuhiko Moriyama; Takuya Kojima; Yasuyuki Arakawa; Yoshihiro Matsukawa; Tomohiko Mizutani; Teiichiro Sakai; Kentaro Oga; Hitoshi Ohkubo; Hiroshi Matsumura; Kaname Hirayanagi


Kanzo | 1993

Response of liver histology to interferon therapy with chronic hepatitis B and C.

Mitsuhiko Moriyama; Fumihiko Komine; Atsuo Shiota; Junko Moriyama; Hiroshi Saitoh; Keizo Fujibayashi; Takashi Motohashi; Kazutomo Suzuki; Shuichi Amaki; Naohide Tanaka; Hitoshi Ohkubo; Hideo Ishizuka; Yoshiki Ono; Yasuyuki Arakawa; Yutaka Matsuo; Nakanobu Hayashi; Masahiko Sugitani; Kohyu Suzuki; Toshikazu Uchida; Toshio Shikata


Kanzo | 1991

Detection of serum HCV antibody ELISA assay using to the C-100 synthetic peptide.

Mitsuhiko Moriyama; Tomohide Takahashi; Nakanobu Hayashi; Toshio Shikata; Junko Moriyama; Shuichi Amaki; Naohide Tanaka; Masahiko Tokoro; Hitoshi Ohkubo; Yasuyuki Arakawa; Yutaka Matsuo; Masakatsu Hashimoto; Kunihiro Nitta; Kiichiro Nakajima


Progress of Digestive Endoscopy(1972) | 1996

A latent case of Schistosomiasis Japonica

Kiyoko Ohtake; Tamiko Saitoh; Atsuo Shiota; Hitoshi Ohkubo; Toshihiro Shimizu; Akira Asaoka; Naohide Tanaka; Kohji Tsubaki; Yohichi Hayashi; Yasuyuki Arakawa

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