Osami Inoue
World Health Organization
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Osami Inoue.
Annals of Internal Medicine | 1999
Haruhiko Yoshida; Yasushi Shiratori; Mitsuhiko Moriyama; Yasuyuki Arakawa; Tatsuya Ide; Michio Sata; Osami Inoue; Michitami Yano; Motohiko Tanaka; Shigetoshi Fujiyama; Shuhei Nishiguchi; Tetsuo Kuroki; Fumio Imazeki; Osamu Yokosuka; Shingo Kinoyama; Gotaro Yamada; Masao Omata
Hepatitis C virus (HCV) infection rarely resolves spontaneously once it becomes chronic (1). Most patients remain asymptomatic for a long period, with liver cirrhosis developing after approximately 30 years (2, 3). Chronic hepatitis C with cirrhosis is a major risk factor for hepatocellular carcinoma (4-7). It has been previously shown that the risk increases with the degree of liver fibrosis (5). Interferon is the only agent known to be effective against HCV infection (8-10). It induces a sustained virologic response in 15% to 30% of patients (11-14). Responders usually show biochemical and histologic improvement (9, 11, 15). Recently, interferon therapy in patients with chronic hepatitis C and cirrhosis was shown to be associated with a reduced incidence of hepatocellular carcinoma (16). Because most patients treated with interferon do not have cirrhosis, we included noncirrhotic as well as cirrhotic patients in our analysis of the effect of interferon therapy on the incidence and prevention of hepatocellular carcinoma. A national surveillance program, the Inhibition of Hepatocarcinogenesis by Interferon Therapy (IHIT) Study, was begun in 1994 as a multicenter, large-scale, retrospective cohort study supported by the Japan Ministry of Health and Welfare as one of the Comprehensive 10-Year Strategy for Cancer Control Projects (17). In this program, patients with chronic hepatitis C who have undergone liver biopsy at one of eight participating institutions are enrolled and followed periodically for development of hepatocellular carcinoma by using several imaging techniques. We analyzed the incidence of hepatocellular carcinoma as of February 1998 by using multivariate proportional hazards regression. Methods Patients The IHIT Study Group approved the design of this study on 21 September 1994. All patients who were positive by a second-generation HCV antibody assay and who had undergone liver biopsy since 1986 at one of the eight participating institutions were enrolled. Patients who were participants in interferon trials for non-A, non-B chronic hepatitis (18-21) and in whom anti-HCV seropositivity was confirmed by using stored sera were also included; these patients had undergone liver biopsy in 1986 or later. Patients were excluded if at the time of liver biopsy they presented with hepatocellular carcinoma or other liver diseases, such as chronic hepatitis B, alcoholic liver disease,autoimmune hepatitis, or primary biliary cirrhosis. The minimum follow-up was established as 1 year for two reasons. First, if hepatocellular carcinoma is detected within 1 year after liver biopsy, the possibility that the cancer was present at the time of liver biopsy cannot be ruled out. Second, interferon therapy must be started within 1year after liver biopsy according to Japanese health insurance rules. By February 1998, 3223 patients who fulfilled the inclusion criteria were registered. Of these patients, 333 were excluded from the analysis: 161 patients (5.0%) transferred to other hospitals without follow-up, and the follow-up period after liver biopsy was less than 1 year for172 patients (5.3%). Thus, 2890 patients were included in the present analysis. Figure 1 shows the schema for patient selection. Figure 1. Schema for patient selection. Interferon therapy was given to 2400 patients; 490patients did not receive treatment (control group). Interferon therapy was initiated within 1 year after liver biopsy (within 6 months in 93% of patients); 84% of patients received interferon-, 14% received interferon-, and 2% received a combination of interferon- and interferon-. The median total dose was 480 MU (first quartile, 324 MU; third quartile, 702 MU), and the median duration of administration was 160 days(first quartile, 94 days; third quartile, 168 days). Once interferon therapy was started, a patient was included in the interferon treatment group even if therapy was discontinued because of adverse events or other reasons. The 490patients who did not receive interferon chose this course of action voluntarily on the basis of concerns about adverse effects; lack of time for therapy; or physician recommendation, which took into account depression, severe diabetes mellitus, or other medical conditions. Serum HCV load was quantitatively determined at the timeof liver biopsy by using various commercial and in-house assays. Because it is difficult to correlate the results of different assay methods, only data obtained with two widely used assays, the branched-DNA probe assay (22) and competitive reverse-transcription polymerase chain reaction (RT-PCR) (23), were used. HCV RNA genotype was determined by RT-PCR using genotype-specific primers (24) or by serologic grouping of serum antibody (25), assuming that genotypes 1a and 1b correspond to serologic group 1 (genotype 1) and genotypes 2a and 2b correspond to serologic group 2 (genotype 2) (11). Histologic Evaluation Liver biopsy specimens were evaluated by a representative pathologist at each institution (a total of eight pathologists were involved) and were scored for the stage of liver fibrosis and grade of inflammatory activity according to the classification of Desmet and colleagues (26). Stage of fibrosis was assessed from stage F0 (no fibrosis) to stage F4 (cirrhosis), and grade of inflammatory activity was scored from grade A1 (mild) to grade A3 (severe). To confirm interobserver concordance in scoring, a subsequent blind and independent examination of 350randomly selected liver biopsy specimens was conducted by two of the eight pathologists. Definition of Interferon Response Virologic and biochemical criteria were used to define response to interferon therapy. Hepatitis C virus RNA was used as a marker of virologic response and was determined by RT-PCR. A virologic sustained response was defined as HCV RNA negativity more than 6 months after termination of interferon therapy; positivity at the same time point was considered a nonsustained response (27). Patients with nonsustained response included those who had temporary disappearance of viremia followed by relapse. In patients treated before the availability of RT-PCR, virologicresponse was determined by using sera stored at 30 C or collected afterward. The serum alanine aminotransferase (ALT) level was used as a marker of biochemical response to interferon therapy. Sustained biochemical response was defined as persistently normal serum ALT levels more than 6 months after termination of interferon therapy; nonsustained response was defined as elevated serum ALT levels at the same time point. Nonsustained response was subdivided into two categories: mildly elevated for a serum ALT level less than two times the upper limit of normal and highly elevated for a serum ALT level two or more times the upper limit of normal. Screening for Hepatocellular Carcinoma Patients were examined for hepatocellular carcinoma by abdominal ultrasonography at least every 6 months. If hepatocellular carcinoma was suspected on the basis of ultrasonographic results, additional procedures, such as computed tomography, magnetic resonance imaging, abdominal angiography, and ultrasonography-guided tumor biopsy, were used to confirm the diagnosis. Statistical Analysis Statistical analysis was performed by using SAS software, version 6.12 (SAS Institute, Inc., Cary, North Carolina). Interobserver concordance of histologic scoring was evaluated by using the Spearman correlation coefficient. Differences between two groups were evaluated by using the unpaired Student t-test or the Mann-Whitney U-test. Categorical data were compared by using the chi-square test or the Fisher exact probability test. Cumulative incidence curves were determined with the Kaplan-Meier method, and the differences between groups were assessed by using the log-rank test. We used the Cox proportional-hazards regression analysis to examine the effect of interferon therapy on the incidence of hepatocellular carcinoma. Because virologic and biochemical responses were mutually dependent, the risk ratio for hepatocellular carcinoma was calculated separately for these factors. The risk ratio attributable to categorical data, such as stage of liver fibrosis and serum ALT level, was calculated by using dummy variables. A P value less than 0.05 was considered statistically significant. Results Patient Characteristics The demographic and clinical features of patients at the time of their enrollment are summarized in Table 1. The frequency distribution of the stages of liver fibrosis differed between interferon-treated patients and untreated patients. Most laboratory values also differed between the two groups. However, differences in laboratory values between treated patients and untreated patients were not significant at the same stage of fibrosis. This indicated the need to adjust for stage of liver fibrosis, which was done in the following analyses. Table 1. Demographic and Clinical Characteristics Histologic Evaluation The concordance in scores for stage of fibrosis and grade of inflammatory activity determined at each institution and by the two representative pathologists was strong, with Spearman coefficients ranging from 0.897 to 0.918 for stage of fibrosis and from 0.878 to 0.849 for grade of inflammatory activity. The original score was sustained by at least one of the two pathologists in 319 of 350 cases for fibrosis staging and in 320 of 350cases for grading inflammatory activity. Response to Interferon Therapy Response to interferon therapy was determined in 2357(98.2%) of the 2400 interferon-treated patients. Response was not determined in43 patients because of insufficient follow-up (<6 months) after termination of therapy. A sustained virologic response was achieved in 789 patients(33.5%). The response rate was similar regardless of the type of interferon used (32.3%, 34.5%, and 25.6% for interferon-, interferon-, and the combination of the two, respectively). A sustained bioch
Journal of Hepatology | 2000
Khaleque Newaz Khan; Hiroshi Yatsuhashi; Kazumi Yamasaki; Masafumi Yamasaki; Osami Inoue; Michiaki Koga; Michitami Yano
BACKGROUND/AIM Time-dependent intrahepatic recurrence of hepatocellular carcinoma is frequent after different treatment modalities, including percutaneous ethanol injection. We attempted to prospectively analyze the possible risk factors for early intrahepatic recurrence of hepatocellular carcinoma after percutaneous ethanol injection. METHODS Sixty-five patients with 65 solitary hepatocellular carcinoma nodules < or =6 cm in diameter underwent initial treatment with percutaneous ethanol injection and were examined to ascertain the factors related to recurrence, local and distant, within the liver. A number of clinical and tumor parameters were analyzed. RESULTS Cumulative overall recurrence rates 12 and 24 months after percutaneous ethanol injection were 15.6% and 45.1%, respectively, irrespective of clinical and tumor parameters. Overall recurrence rates 12 and 24 months after percutaneous ethanol injection were 40% and 67.5%, for tumor > or =3 cm and 7.5% and 37.5%, for tumor <3 cm. Cumulative local recurrence rates at 12 and 24 months were 26.3% and 43.5%, respectively, for tumor > or =3 cm and 11.7% and 18.2%, respectively, for tumor <3 cm. The log-rank test indicated that a tumor size of > or =3 cm and the presence of capsule for a tumor of <3 cm in diameter were significant risk factors for intrahepatic recurrence. A pretreatment serum PIVKA-II level of > or =0.02 AU/ml was the only clinical parameter associated with overall recurrence (p=0.0041) and distant intrahepatic recurrence (p=0.0307). Distant intrahepatic recurrence rates 12 and 24 months after percutaneous ethanol injection were 22.5% and 31.4%, respectively, for PIVKA-II levels of > or =0.02 AU/ml and 8% and 17.8%, for PIVKA-II of <0.02 AU/ml. Coxs proportional hazard model identified that tumor size, tumor capsule and baseline serum PIVKA-II levels were independently related to intrahepatic recurrence. CONCLUSIONS These data demonstrate that tumor size and peritumoral capsule were associated with overall and local recurrence of hepatocellular carcinoma. Moreover, pretreatment serum levels of PIVKA-II can indicate the risk of early intrahepatic recurrence and may assist in patient selection and appropriate therapy.
Journal of Gastroenterology and Hepatology | 1998
Tomoyuki Aritomi; Hiroshi Yatsuhashi; Tatsuya Fujino; Kazumi Yamasaki; Osami Inoue; Michiaki Koga; Yuji Kato; Michitami Yano
It was recently reported that mutations in the precore and core promoter region of hepatitis B virus (HBV) are associated with fulminant hepatitis. The aim of this study was to investigate the association of mutations in the precore and core promoter region of HBV with fulminant and severe acute hepatitis. We studied Japanese patients with acute HBV infection, including seven patients with fulminant hepatitis, 12 with severe acute hepatitis and 41 with acute self‐limited hepatitis. The presence of HBV mutants was examined by using a point mutation assay to detect a G to A transition at position 1896 in the precore region and an A to T transition at position 1762 and a G to A transition at position 1764 in the core promoter region. Significant differences in the proportion of mutations in the precore or core promoter region were present between patients with fulminant hepatitis and self‐limited acute hepatitis (7/7 (100%) vs 4/41 (9.8%), P < 0.01) and between severe acute hepatitis and self‐limited acute hepatitis (6/12 (50.0%) vs 4/41 (9.8%), P < 0.01). The frequency of mutation increased proportionately with the severity of disease in patients with acute HBV infection. Fulminant hepatitis B in Japan is closely associated with mutations in the core promoter and precore gene of HBV. Point mutation assays for HBV precore and core promoter analysis may be useful to predict the outcome of liver disease in patients with acute HBV infection.
Liver International | 2007
Hisamitsu Miyaaki; Tatsuki Ichikawa; Kazuhiko Nakao; Hiroshi Yatsuhashi; Ryuji Furukawa; Kazuo Ohba; Katsuhisa Omagari; Yukio Kusumoto; Kenji Yanagi; Osami Inoue; Noboru Kinoshita; Hiromi Ishibashi; Michitami Yano; Katsumi Eguchi
Background/Aims: We evaluated patients with nonalcoholic fatty liver disease (NAFLD) and compared the clinical and pathological features to identify the risk factors for NAFLD with severe fibrosis.
Journal of Hepatology | 1999
Hiroshi Yatsuhashi; Tatsuya Fujino; Takenori Matsumoto; Osami Inoue; Michiaki Koga; Michitami Yano
BACKGROUND/AIMS This study aimed to determine the expression level of interferon alpha/beta (IFN-alpha/beta) receptor in the liver immunohistochemically and evaluate its usefulness in predicting the outcome to IFN therapy in patients with chronic hepatitis C. METHODS The level of IFN-alpha/beta receptor expression was determined in immunoperoxidase-stained pretreatment sections of 55 chronic hepatitis C patients later treated with IFN. We used liver biopsy specimens and mouse monoclonal anti-human IFN-alpha/beta receptor antibody. Quantitative analysis of immunostaining was performed by image analysis software. The level of IFN-alpha/beta receptor was expressed as Unit (U). Sustained responders were patients who showed persistent disappearance of serum HCV-RNA during the 6-month period after treatment, while non-responders showed persistence of viremia after therapy. RESULTS Positive immunostaining was observed in the cytoplasm of hepatocytes. The mean expression level of hepatic IFN-alpha/beta receptor in sustained responders (2.65+/-1.11 U, n = 15) was significantly (p<0.001) higher than in non-responders (1.61+/-1.05 U, n = 40). A significant decrease in IFN-alpha/beta receptor expression level was observed in patients with advanced liver fibrosis. In patients with low level viremia (pretreatment serum HCV-RNA <1 Meq/ml, n = 18), the level of IFN-alpha/beta receptor in sustained responders (2.89+/-1.12 U, n = 11) was significantly (p<0.01) higher than in non-responders (0.93+/-0.33 U, n = 7). CONCLUSIONS Our results suggest that measurement of the level of hepatic IFN-alpha/beta receptor in patients with chronic hepatitis C might be useful for predicting the response to IFN therapy. Resistance to IFN therapy in patients with chronic hepatitis C might be due to low levels of hepatic IFN-alpha/beta receptor.
Gastroenterology Research and Practice | 2012
Naota Taura; Tatsuki Ichikawa; Hisamitsu Miyaaki; Yoshiko Kadokawa; Takuya Tsutsumi; Shotaro Tsuruta; Yuji Kato; Osami Inoue; Noboru Kinoshita; Kazuo Ohba; Hiroyuki Kato; Kazuyuki Ohata; Jun-ichi Masuda; Keisuke Hamasaki; Hiroshi Yatsuhashi; Kazuhiko Nakao
Background. HCV infection is associated with lipid disorders because this virus utilizes the host lipid metabolism to sustain its life cycle. Several studies have indicated that higher concentrations of serum cholesterol and LDL before treatment are important predictors of higher rates of sustained virological response (SVR). However, most of these studies involved patients infected with HCV genotype 1. Thus, we performed a multi-institutional clinical study to evaluate the impact of lipid profiles on SVR rates in patients with HCV genotype 2. Methods. A total of 100 chronic hepatitis C patients with HCV genotype 2 who received peg-IFN alfa-2b and ribavirin therapy were consecutively enrolled. The significance of age, sex, BMI, AST level, ALT level, WBC, hemoglobin, platelet count, gamma-glutamyltransferase, total cholesterol level (TC), LDL level, HCV RNA, and histological evaluation was examined for SVR using logistic regression analysis. Results. The 100 patients infected with HCV genotype 2 were divided into 2 groups, an SVR group and a non-SVR group. Characteristics of each group were subsequently compared. There was no significant difference in the level of HCV RNA, BMI, platelet, TG, or stage of fibrosis between the groups. However, there were significant differences in the levels of TC and LDL-C. In multivariate logistic regression analysis using baseline characteristics, high TC level was an independent and significant risk factor (relative risk 18.59, P = 0.015) for SVR. Conclusion. Baseline serum total cholesterol levels should be considered when assessing the likelihood of sustained treatment response following the course of peg-IFN and ribavirin therapy in patients with chronic HCV genotype 2 infection.
Journal of Gastroenterology and Hepatology | 1997
Hiroshi Yatsuhashi; Kazumi Yamasaki; Tomoyuki Aritomi; Parquet Maria Del Carmen; Osami Inoue; Michiaki Koga; Michitami Yano
We analysed the expression of interferon (IFN) α/β receptor mRNA in the liver of patients with chronic hepatitis C and examined the relationship between the expression of this receptor gene and the level of hepatitis C virus (HCV)‐RNA as well as the response to 16 weeks of 6 × 106 units IFN. The mean level of IFNα/β receptor mRNA in patients with chronic HCV infection (expressed as δ cycle; 10.8±1.9 (mean±SD); n = 39) was significantly higher than that of control subjects (9.4±0.5; n=6; P<0.01). There was a significant negative correlation between the level of IFNα/β receptor mRNA and serum HCV‐RNA in 39 patients with chronic hepatitis C (R=‐0.546; P<0.01). The mean level of IFNα/β receptor mRNA in six patients who showed a complete response to IFN therapy (12.3±1.6) was higher than that of 15 patients who failed to respond to therapy (10.1±1.5; P< 0.01). Our results are consistent with the suggestion that the anti‐viral activity of IFN depends on the level of the IFNα/β receptor on hepatocytes in patients with chronic hepatitis C.
Journal of Gastroenterology and Hepatology | 1993
Hiroshi Yatsuhashi; Osami Inoue; K. Inokuchi; Michiaki Koga; Shigenobu Nagataki; Tai-An Cha; Bruce Irvine; Michelle M. Stempien; Janice A. Kolberg; Mickey S. Urdea; Michitami Yano
Abstract Hepatitis C virus RNA (HCV‐RNA) and serological markers of HCV infection were measured in 30 patients with chronic hepatitis C who had been treated with interferon (IFN). Patients were classified into four groups according to serum alanine aminotransferase (ALT) levels after treatment. These were: as complete responders (CR); partial responders (PR); transient responders (TR); and non‐responders (NR). In all 11 patients in the CR group, HCV‐RNA disappeared from serum for at least 24 months and anti‐c100‐3 decreased progressively during this time. In the PR group, four of five patients were positive for HCV‐RNA in spite of the improvement of ALT levels and decline of anti‐c100‐3. In the TR and NR groups, HCV‐RNA disappeared transiently or remained persistently positive. The results indicate that IFN‐mediated improvement of ALT and decrease of anti‐HCV (anti‐c100‐3) were not always related to the disappearance of HCV‐RNA from serum. On the other hand, sustained disappearance of HCV‐RNA from serum was demonstrated in the patients who did not have post‐treatment ALT relapse. This indicates that IFN can eradicate HCV from serum in some patients and provide a clinical remission of chronic hepatitis C.
Journal of Hepatology | 1999
Maria del Carmen Parquet; Hiroshi Yatsuhashi; Michiaki Koga; Osami Inoue; Takehiro Matsumoto; Rumiko Hamada; Akira Igarashi; Michitami Yano
BACKGROUND/AIMS Recently, a novel DNA virus was isolated from the serum of a patient with post-transfusion non-A-G hepatitis and named TT virus. The aim of this study was to determine the prevalence and clinical characteristics of TT virus infection in patients with sporadic acute hepatitis of unknown etiology. METHODS TT virus was investigated in the serum of 66 patients with sporadic acute hepatitis non-A-G and 50 healthy controls by semi-nested PCR with previously published primers. RESULTS TT virus was detected in 17 (26%) of the 66 patients with sporadic acute hepatitis non-A-G and in a slightly higher rate (34%,17/50) in the control group. No significant differences in alanine aminotransferase or bilirubin concentrations were observed between the groups of patients with or without TT virus infection. Eighty per cent (12/15) of patients for whom follow up was possible had persistent viremia from 4 to 36 months, and 67% (8/12) of these patients had already normalized their levels of alanine aminotransferase. A phylogenetic tree constructed by the Neighbor Joining Method revealed that all isolates in this study were grouped within genotype 1a and 1b, without showing any association between genetic type and development of hepatic disease. CONCLUSIONS Our results suggest that TT virus DNA is present not only in patients with sporadic acute hepatitis non-A-G but also in a large proportion of the general population. This virus was not likely to be the causative agent of hepatitis among the patients in this study.
Hepatology Research | 2011
Takumi Kawaguchi; Tatsuyuki Kakuma; Hiroshi Yatsuhashi; Hiroshi Watanabe; Hideki Saitsu; Kazuhiko Nakao; Akinobu Taketomi; Satoshi Ohta; Akinari Tabaru; Kenji Takenaka; Toshihiko Mizuta; Kenji Nagata; Yasuji Komorizono; Kunitaka Fukuizumi; Masataka Seike; Shuichi Matsumoto; Tatsuji Maeshiro; Hirohito Tsubouchi; Toyokichi Muro; Osami Inoue; Motoo Akahoshi; Michio Sata
Aim: Non‐hepatitis B virus/non‐hepatitis C virus‐related hepatocellular carcinoma (NBNC‐HCC) is often detected at an advanced stage, and the pathology associated with the staging of NBNC‐HCC remains unclear. Data mining is a set of statistical techniques which uncovers interactions and meaningful patterns of factors from a large data collection. The aims of this study were to reveal complex interactions of the risk factors and clinical feature profiling associated with the staging of NBNC‐HCC using data mining techniques.