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Featured researches published by Yoshimi Ito.


The Lancet | 1991

Resolution of acute hepatitis C after therapy with natural beta interferon

Masao Omata; Osamu Yokosuka; Susumu Takano; Naoya Kato; Kazuhiko Hosoda; Fumio Imazeki; Motohisa Tada; Yoshimi Ito; Masao Ohto

To test whether interferon can prevent acute non-A, non-B hepatitis from becoming chronic, a prospective controlled trial was conducted in 25 patients; 11 were treated for an average of 30 days with a mean of 52 megaunits of interferon and 14 acted as controls. 4 patients in the treatment group who continued to have raised serum aminotransferase concentrations after a years follow-up were given a second course of interferon. Follow-up at 3 years has revealed that all but 1 of those treated showed normal serum aminotransferase, whereas only 3 controls showed such change (p less than 0.02). Serum hepatitis C virus RNA became undetectable in 10 of 11 treated and in only 1 of 12 control patients, which suggests that interferon prevents the progression of acute non-A, non-B hepatitis to chronicity by eradicating HCV.


Journal of Clinical Investigation | 1993

Mutations in core nucleotide sequence of hepatitis B virus correlate with fulminant and severe hepatitis.

Toshiki Ehata; Masao Omata; Osamu Yokosuka; Yoshimi Ito; Kazuhiko Hosoda; Masao Ohto

Infection with hepatitis B virus leads to a wide spectrum of liver injury, including self-limited acute hepatitis, fulminant hepatitis, and chronic hepatitis with progression to cirrhosis or acute exacerbation to liver failure, as well as an asymptomatic chronic carrier state. Several studies have suggested that the hepatitis B core antigen could be an immunological target of cytotoxic T lymphocytes. To investigate the reason why the extreme immunological attack occurred in fulminant hepatitis and severe exacerbation patients, the entire precore and core region of hepatitis B virus DNA was sequenced in 24 subjects (5 fulminant, 10 severe fatal exacerbation, and 9 self-limited acute hepatitis patients). No significant change in the nucleotide sequence and deduced amino acid residue was noted in the nine self-limited acute hepatitis patients. In contrast, clustering changes in a small segment of 16 amino acids (codon 84-99 from the start of the core gene) in all seven adr subtype infected fulminant and severe exacerbation patients was found. A different segment with clustering substitutions (codon 48-60) was also found in seven of eight adw subtype infected fulminant and severe exacerbation patients. Of the 15 patients, 2 lacked precore stop mutation which was previously reported to be associated with fulminant hepatitis. These data suggest that these core regions with mutations may play an important role in the pathogenesis of hepatitis B viral disease, and such mutations are related to severe liver damage.


Gastroenterology | 1985

Recombinant Leukocyte A Interferon Treatment in Patients With Chronic Hepatitis B Virus Infection: Pharmacokinetics, Tolerance, and Biologic Effects

Masao Omata; Fumio Imazeki; Osamu Yokosuka; Yoshimi Ito; Katsuo Uchiumi; Junko Mori; Kunio Okuda

Large doses of recombinant leukocyte A interferon were administered to 20 patients with deoxyribonucleic acid polymerase- and hepatitis B e antigen-positive chronic hepatitis B to study the maximum tolerated dose, its pharmacokinetics, and its antiviral activity. The first group of 5 patients received a constant dose of 36 X 10(6) U/day for 28 consecutive days. When it was well tolerated, the second, third, and fourth groups (5 patients each) received 50, 72, and 100 X 10(6) U/day, respectively. All 20 patients completed the 28-day treatment. Hourly and daily profile of serum interferon level showed a dose-dependent effect with an increasing dosage, and cumulative effects during the treatment. The mean peak serum interferon concentration ranged from 93 U/ml on day 1 in the first group to 1271 U/ml on day 28 in the fourth group. Inhibition of serum deoxyribonucleic acid polymerase activity and hepatitis B virus-deoxyribonucleic acid during the treatment was compared between the groups with low doses (36 and 50 X 10(6) U) and high doses (72 and 100 X 10(6) U). Low doses of interferon suppressed deoxyribonucleic acid polymerase activity to the same extent as did the high doses. Prednisolone withdrawal was combined with interferon in 5 patients. Three patients treated with such combination became seronegative for hepatitis B e antigen during the treatment, whereas all 15 with interferon alone remained seropositive. These results suggest that a maximum antiviral effect of recombinant leukocyte A interferon is below the maximum tolerated doses.


Gastroenterology | 1985

Discordance of hepatitis B e antigen/antibody and hepatitis B virus deoxyribonucleic acid in serum: Analysis of 1063 specimens

Yasuhisa Matsuyama; Masao Omata; Osamu Yokosuka; Fumio Imazeki; Yoshimi Ito; Kunio Okuda

Hepatitis B virus DNA was determined in 1063 serum samples from 252 patients with hepatitis B surface antigen by the spot hybridization technique. The results were correlated with hepatitis B e antigen and antibody. Hepatitis B virus DNA was detected in 87% of hepatitis B e antigen-positive patients, in 18% of hepatitis B e antibody-positive patients, and in 18% of those negative for both. Discordance of antigen/antibody and hepatitis B virus DNA, i.e., the presence of the DNA in antibody-positive sera or the absence of the DNA in antigen-positive sera, was observed in 209 of 997 (21%) samples. Of 121 patients with histologic diagnosis, this discordance was observed in none of 20 patients with nonspecific changes, in 13% of 39 with chronic persistent hepatitis, in 21% of 38 with chronic active hepatitis, and in 38% of 24 with cirrhosis. Thus, hepatitis B e antigen/antibody testing alone failed to predict the presence or absence of circulating hepatitis B virion in a significant proportion of patients with advanced chronic liver disease.


The New England Journal of Medicine | 1986

Hepatitis B virus RNA transcripts and DNA in chronic liver disease

Osamu Yokosuka; Masao Omata; Fumio Imazeki; Yoshimi Ito; Kunio Okuda

To study the relation between gene expression of hepatitis B virus (HBV) and liver disease, we studied HBV RNA transcripts and DNA in liver-biopsy specimens from 30 patients with chronic liver disease (17 seropositive for hepatitis B surface antigen and 13 seronegative). HBV-specific RNA was found in all the seropositive patients and in none of the seronegative patients. Two major RNAs, sizes 29S (long) and 21S (short), were found in nine seropositive patients, of whom seven had free HBV DNA and eight were seropositive for hepatitis B e antigen. Six of the nine patients had hepatitis B core antigen in hepatocytes and active liver disease. In contrast, inactive liver disease was noted in the remaining eight seropositive patients, who had only one (21S) RNA. None of these patients had free HBV DNA (five of eight had integrated DNA) or hepatitis B core antigen in hepatocytes. Hybridization analysis suggested that 29S and 21S RNAs are messenger RNAs of hepatitis B core antigen and hepatitis B surface antigen, respectively. These data indicate that the free DNA and its products are causally related to the activity of liver disease and that once HBV DNA has been integrated, the disease will become quiescent. None of the determinants were identified in patients seronegative for hepatitis B surface antigen.


Gastroenterology | 1985

Combination of short-term prednisolone and adenine arabinoside in the treatment of chronic hepatitis B

Osamu Yokosuka; Masao Omata; Fumio Imazeki; Katsutaro Hirota; Junko Mori; Katsuo Uchiumi; Yoshimi Ito; Kunio Okuda

The efficacy of adenine arabinoside (Ara-A) alone or in combination with prednisolone utilizing its withdrawal effect was studied in 43 patients with deoxyribonucleic acid polymerase- and hepatitis B e antigen-positive chronic hepatitis. Ten patients were treated with 10 mg/kg body wt of Ara-A alone for 4-8 wk. In 9 cases, prednisolone (40 mg/day) was given at a constant dosage for 4 wk before Ara-A treatment. Fourteen patients received oral prednisolone alone for 4 wk, and 10 patients served as untreated controls. Six of 9 patients (67%) undergoing the combination therapy became seronegative for hepatitis B e antigen, whereas only 4 of 24 patients (17%) treated either with Ara-A alone or prednisolone alone lost the antigen. Two of the 10 untreated patients became seronegative for hepatitis B e antigen during the same follow-up period of 9 mo. This prospective controlled study suggests that the combination of immunomodulation by steroid withdrawal and subsequent Ara-A is more effective in the treatment of patients with chronic liver disease and active hepatitis B virus replication than treatment with Ara-A alone.


Digestive Diseases and Sciences | 1989

Histological changes of the liver by treatment of chronic non-A, non-B hepatitis with recombinant leukocyte interferon alpha

Masao Omata; Yoshimi Ito; Osamu Yokosuka; Fumio Imazeki; Katsuo Uchiumi; Susumu Takano; Kazuhiko Hosoda; Masao Ohto

We have treated 17 patients with non-A, non-B chronic hepatitis by recombinant interferon alpha (0.3–9 megaunits for 4–28 weeks). In six patients, serum aminotransferase levels fell to normal or near-normal range during treatment. The mean levels of serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in 17 patients fell from 156±80 (mean±sd) and 213±135 at the beginning of treatment to 94±49 and 112±71, respectively, at the end of treatment. In 12 patients, liver biopsies were performed before and after (or during) the treatment, and histological activity indices (HAI) were blindly examined by two independent observers. For comparison, we examined histological changes of pre- and posttreatment liver biopsies of 19 patients who were treated by recombinant interferon for chronic hepatitis B. Mean HAI scores improved from 10.0 to 5.4 after treatment in non-A, non-B chronic hepatitis. The most marked reduction was noted in scores of portal inflammation and hepatocellular degeneration and/or necrosis. No such reduction was observed in B- viral chronic hepatitis. These data indicated that rapid biochemical resolution by the treatment was related to histological improvement of the liver in our patients with non-A, non-B hepatitis.


Digestive Diseases and Sciences | 1991

Randomized, double-blind, placebo-controlled trial of eight-week course of recombinant α-interferon for chronic non-A, non-B hepatitis

Masao Omata; Yoshimi Ito; Osamu Yokosuka; Fumio Imazeki; Masami Tagawa; Susumu Takano; Kazuhiko Hosoda; Minoru Tada; Masao Ohto; Kazuto Ito; Kunio Okuda

Forty-nine Japanese patients were enrolled in a randomized, placebo-controlled, doubleblind trial of α-interferon for chronic non-A, non-B hepatitis: 24 patients received 3 million units of recombinant human alpha α-interferon (α-2a) thrice weekly for eight weeks, and 25 patients received placebo in a similar schedule. The mean serum alanine aminotransferase (ALT) dropped from 155±91 (sd) to 69±72 during interferon treatment, but remained unchanged (158±140 to 147±130) during placebo treatment (P<0.001). Serum ALT level fell to the normal range in 29% of interferon-treated patients, but in only 4% of placebo-treated patients. Pre- and posttreatment liver biopsies were obtained in all but one case. Average histological activity indices (HAI) were markedly improved in the interferon-treated group (9.5±3.7 to 7.0±4.3), but were unchanged in the placebo group (8.5±4.3 to 8.5±4.9). In addition, we compared the efficacy of interferon treatment between anti-hepatitis C virus (HCV) antibody positive and negative groups. Biochemical and histological improvements were similar and statistically significant in patients with and without antibody to hepatitis C virus. These data indicate that a eight-week course of α-interferon induces biochemical and histological improvement in more than half the patients with chronic non-A, non-B hepatitis.


Gastroenterology | 1987

Correlation of Hepatitis B Virus DNA and Antigens in the Liver A Study in Chronic Liver Disease

Masao Omata; Osamu Yokosuka; Fumio Imazeki; Yoshimi Ito; Junko Mori; Katsuo Uchiumi; Kunio Okuda

Hepatitis B virus deoxyribonucleic acid (DNA) and antigens (HBsAg and HBcAg) were studied in liver biopsy specimens from 105 HBsAg-positive patients with chronic liver diseases. Free or integrated viral DNA, or both, was detected in 83 of 105 (79%) patients, whereas HBsAg and HBcAg were demonstrated immunohistologically in 96 (91%) and 39 (37%), respectively. Of 60 patients with detectable free viral DNA, 38 (63%) were positive for HBcAg, whereas only 1 of 45 (2%) with either integrated viral DNA alone (n = 23) or no detectable viral DNA (n = 22) was positive for HBcAg (p less than 0.001). Furthermore, the amount of HBcAg was positively correlated with the amount of free viral DNA in the liver tissue. In contrast, HBsAg was well expressed not only in the liver with free viral DNA, but also in the liver with integrated DNA. These data suggest that the synthesis of HBcAg is primarily directed by free viral DNA, whereas that of HBsAg may be directed by free as well as integrated viral DNAs.


Gut | 1995

Efficacy of longterm interferon treatment in chronic liver disease evaluated by sensitive polymerase chain reaction assay for hepatitis C virus RNA.

Osamu Yokosuka; Naoya Kato; Kazuhiko Hosoda; Yoshimi Ito; Fumio Imazeki; Masao Ohto; Masao Omata

Effects of interferon treatment on hepatitis C virus were examined by investigating the presence of hepatitis C virus ribonucleic acid and anti-hepatitis C virus antibody in 70 patients with non-A, non-B chronic liver diseases. Twenty one patients were treated with three million units of interferon alfa 2a three times a week for 52 weeks, 24 patients were treated similarly for eight weeks, and 25 patients were given a placebo for eight weeks and served as control. Sixty six of 70 patients (94%) were positive for both hepatitis C virus RNA and second generation anti-hepatitis C virus antibody. Fourteen of 21 (67%) receiving the longterm treatment had a normalised alanine aminotransferase (ALT) activity, and in 12 of these hepatitis C virus ribonucleic acid became undetectable by the end of treatment and remained so during the three year follow up after the treatment. Anti-hepatitis C virus antibody determined by first generation assay became negative in one case at the end of the 52 week treatment, and in four cases at the end of the one year follow up. In contrast, only one of 24 (4%) who received the eight week treatment and only one of 25 (4%) who received the placebo had normalised ALT activities. Hepatitis C virus ribonucleic acid became negative in two patients undergoing short-term treatment and in none receiving the placebo. Thus, longterm interferon treatment seems effective in clearing hepatitis C virus from serum of patients with chronic liver disease.

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