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Dive into the research topics where Manabu Masuzawa is active.

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Featured researches published by Manabu Masuzawa.


Journal of Hepatology | 1997

Circulating matrix metalloproteinase-2 and tissue inhibitor of metalloproteinase-1 as serum markers of fibrosis in patients with chronic hepatitis C : relationship to interferon response

Akinori Kasahara; Norio Hayashi; Kiyoshi Mochizuki; Masahide Oshita; Kazuhiro Katayama; Michio Kato; Manabu Masuzawa; Harumasa Yoshihara; Masafumi Naito; Takeshi Miyamoto; Atsuo Inoue; Akira Asai; Taizou Hijioka; Hideyuki Fusamoto; Takenobu Kamada

BACKGROUND/AIMS/METHODS The imbalance between matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMPs) is considered to be an important determinant of extracellular matrix deposition and breakdown. We measured serum MMP-1, MMP-2, TIMP-1 and TIMP-2 levels using the respective one-step sandwich enzyme immunoassays in 98 patients with chronic hepatitis C treated with interferon beta to examine their clinical significance for assessment of liver histology and to determine whether they can be useful as predictors of the interferon response. RESULTS Serum TIMP-1 levels showed a positive correlation with the degree of fibrosis (r(s)=0.30, p= 0.004). Serum MMP-2 levels revealed positive relationships with the degree of periportal necrosis (r(s)= 0.32, p=0.002), the degree of fibrosis (r(s)=0.26, p= 0.01) and total score of histological activity index (r(s)=0.24, p=0.02). Serum MMP-2 levels were significantly higher in patients with no response than in those with sustained and transient response (p<0.01 and p<0.05, respectively), while serum MMP-1 levels did not differ among the three groups. Compared with the levels in sustained responders, the total amounts of serum TIMP-1 were significantly lower in transient responders and non-responders (p<0.01 and p<0.001, respectively). As for serum TIMP-2 levels, a significant decrease was found in transient responders and non-responders (p<0.01). The ratios of serum MMP-2 to TIMP-1 levels were significantly higher in transient responders and non-responders than in sustained responders (p<0.001, respectively) even when HCV RNA levels were low in patients with HCV genome subtype 1b or when the HCV genome subtype was 2a or 2b. Sustained response was never found in type 1b patients with ratios of serum MMP-2 to TIMP-1 levels of over 6.0. In logistic multivariate regression analysis, the ratios of serum MMP-2 to TIMP-1 level (p=0.0001), HCV genome subtype (p=0.005) and serum TIMP-2 level (p=0.03) were the independent predictors for sustained response, while serum MMP-2 level (p=0.0006) was the only predictor for no response. CONCLUSIONS Serum MMP-2 and TIMP-1 levels might be useful for estimating the degree of liver fibrosis. The ratio of serum MMP-2 to TIMP-1 levels may serve as a new predictor of interferon response in patients with chronic hepatitis C.


International Journal of Cancer | 2000

Effect of interferon therapy on the incidence of hepatocellular carcinoma and mortality of patients with chronic hepatitis C: a retrospective cohort study of 738 patients.

Hideo Tanaka; Hideaki Tsukuma; Akinori Kasahara; Norio Hayashi; Harumasa Yoshihara; Manabu Masuzawa; Tsutomu Kanda; Tohoru Kashiwagi; Atsuo Inoue; Michio Kato; Akira Oshima; Yoko Kinoshita; Takenobu Kamada

The effect of interferon on the long‐term clinical outcome of patients with chronic hepatitis C remains unclear. This study included 594 patients with chronic hepatitis C who received interferon‐α therapy (Interferon group) and 144 patients with chronic hepatitis C who did not receive interferon (Control group). The patients in the Interferon group were classified into the following three groups based on the response of the serum aminotransaminase level of the patient during and after completion of the therapy protocol: sustained responders (n = 175), transient responders (n = 165), and non‐responders (n = 254). The age, sex, serum aminotransaminase level, platelet count, histological staging, hepatitis C virus (HCV) subtype, and HCV concentration at baseline were adjusted with the Cox proportional hazards model. The length of follow‐up for assessment of the risk for developing hepatocellular carcinoma (HCC) was 57.2 ± 13.9 months in the Interferon group and 67.7 ± 28.7 months in the Control group. Multivariate analysis showed that interferon therapy decreased the risk for developing HCC by 48% compared with that in the Control group (P = 0.064). The older the age, being male, having a low platelet count, and higher histological stage were independent factors associated with the development of HCC. The hazard rate ratio for development of HCC in the sustained responders, transient responders, and non‐responders was 0.16 (95% confidence interval [CI]: 0.04–0.62), 0.27 (95% CI: 0.09–0.79), and 0.74 (95% CI: 0.37–1.48), respectively. During follow‐up, 18 patients in the Interferon group died (10 from liver‐related diseases) and 17 patients in the Control group died (10 from liver‐related diseases). No sustained responder or transient responder in the Interferon group died of liver‐related disease. The cumulative survival rates of the Interferon and Control groups were nearly identical during the first 5 years following diagnosis. Thereafter, the cumulative survival rate of the Control group declined, resulting in an 8‐year survival rate in the Interferon and Control groups of 97% and 81%, respectively (P = 0.061). Similar trends were seen in the survival analysis of those who had died of liver disease: the 8‐year survival rates of the Interferon and Control groups were 98% and 88%, respectively (P = 0.32). Our study demonstrated that interferon therapy significantly lowered the incidence of HCC among patients with chronic hepatitis C who showed sustained normalization and among patients who showed transient normalization of the serum aminotransferase level after completion of interferon therapy. The survival analyses and determination of cause of death suggested that interferon therapy improves the long‐term survival of chronic hepatitis C patients who respond to this therapy, possibly by decreasing mortality from liver‐related diseases. Int. J. Cancer 87:741–749, 2000.


Cancer Chemotherapy and Pharmacology | 1992

Prospective and randomized clinical trial for the treatment of hepatocellular carcinoma — a comparison of lipiodol-transcatheter arterial embolization with and without Adriamycin (first cooperative study)

Saburo Kawai; Jun Okamura; Makoto Ogawa; Yasuo Ohashi; Masayoshi Tani; Jushiro Inoue; Yoshifumi Kawarada; Mitsuo Kusano; Yasuhiko Kubo; Chikazumi Kuroda; Yu Sakata; Yoshiyuki Shimamura; Kenji Jinno; Akira Takahashi; Kenichi Takayasu; Kazuo Tamura; Naofumi Nagasue; Yoshimi Nakanishi; Masaoki Makino; Manabu Masuzawa; Shuichi Mikuriya; Morito Monden; Yasuhiro Yumoto; Takesada Mori; Toshitsugu Oda

SummaryA randomized, controlled clinical trial comparing the use of lipiodol-transcatheter arterial embolization (L-TAE) in the presence versus the absence of Adriamycin (ADR) for the treatment of hepatocellular carcinoma was conducted from August 1988 through September 1989. In all, 125 Japanese hospitals participated in this study and 289 patients were entered in the trial. The patients were randomly allocated into group A (L-TAE) or group B (L-TAE+ADR) by telephone registration. There was no significant difference in background factors between group A and group B. Additional treatment, including repeated TAE or hepatic resection, was given to 189 patients. Among the four endpoints analyzed, the rate of tumor reduction and lipiodol accumulation in the tumor did not significantly differ between the two groups. The 3-year survival values for groups A and B were 33.6% and 34.9%, respectively; the difference was not significant. The serum alpha-fetoprotein level, however, decreased to a significantly greater extent in the group that received ADR than in the group that did not (P<0.05). This result suggests that ADR has some favorable additional effect in L-TAE for the treatment of hepatocellular carcinoma.


Journal of Hepatology | 1994

Hepatitis C virus antibody and hepatitis C virus replication in chronic hepatitis B patients

Kazuyoshi Ohkawa; Norio Hayashi; Nobukazu Yuki; Hideki Hagiwara; Michio Kato; Keiji Yamamoto; Hiroshi Eguchi; Hideyuki Fusamoto; Manabu Masuzawa; Takenobu Kamada

We assessed hepatitis C virus infection in 156 chronic hepatitis B patients using second-generation hepatitis C virus antibody (anti-HCV). Active virus replication was further investigated in anti-HCV-positive cases by means of polymerase chain reaction assay for the detection of serum hepatitis C virus RNA. Anti-HCV prevalence was higher in patients negative for hepatitis B e antigen (HBeAg) (10/48, 21%) than in HBeAg-positive patients (10/108, 9%) (p < 0.05), and the reactivity (cut-off index) in anti-HCV enzyme-linked immunosorbent assay of the positive cases was significantly higher in HBeAg-negative patients (4.1 +/- 0.1) than in -positive ones (3.6 +/- 0.6) (p < 0.05). The prevalence of hepatitis C virus RNA in anti-HCV-positive cases was also higher in the HBeAg-negative group (9/10, 90%) than in the -positive group (3/10, 30%) (p < 0.01). Viremia was found in association with high reactivity in anti-HCV ELISA (cut-off index > 3.5) in both groups. Nine (90%) of 10 such cases were viremic in the HBeAg-negative group compared with three (43%) of seven in the HBeAg-positive group (p < 0.05). These results suggest that hepatitis C virus replication may be influenced by hepatitis B virus replicative states, indicating possible interference between hepatitis B and C viruses.


Journal of Gastroenterology | 1998

Thrombotic thrombocytopenic purpura developed suddenly during interferon treatment for chronic hepatitis C

Kenya Iyoda; Michio Kato; Takeshi Nakagawa; Yoshimi Kakiuchi; Yasunori Sugiyasu; Eriko Fujii; Kenji Fujimoto; Tomoki Michida; Akira Kaneko; Nobuhiko Hayashi; Keiji Yamamoto; Kazuhei Kurosawa; Masahiro Ikeda; Manabu Masuzawa

Abstract: A 57-year-old man had abnormal hepatic function identified in April 1994. In October 1994, chronic hepatitis C was diagnosed. Based on the findings of a liver biopsy, administration of recombinant interferon (rIFN)-α2b was begun. In the 16th week of treatment, the patient experienced headache and fever and developed a markedly decreased, platelet count and hemolytic anemia. He was admitted on May 19, 1995 and thrombotic thrombocytopenic purpura (TTP) was diagnosed. He died on the 3rd hospital day. The causes of TTP have yet to be elucidated, but in this patient the occurrence of TTP appeared to be related to the IFN treatment for chronic hepatitis C.


Journal of Hepatology | 1993

Clinical applications of ICG Finger Monitor in patients with liver disease

Yoshitaka Ishigami; Manabu Masuzawa; Eiji Miyoshi; Michio Kato; Kazuya Tamura; Masahiko Kanda; Kunio Awazu; Kunihiro Taniguchi; Masahiro Kurita; Norio Hayashi; Sunao Kawano; Hideyuki Fusamoto; Takenobu Kamada

The indocyanine green (ICG) Finger Monitor system is a non-invasive indication of ICG concentrations in the blood. In this study, significant correlation was found between the sensor signal voltage and plasma ICG concentrations ranging from 0.04 mg/dl to 1.0 mg/dl (r = 0.998, P < 0.001) in vivo. The ICG clearance curve showed an initial sharp rise 20-30 s after bolus injection, followed by a small rise. The concentration then deceased exponentially. In 196 patients with chronic liver disease, there was a close correlation between the KICG (plasma disappearance rate) and R15 (blood retention ratio at 15 min) (r = 0.886, P < 0.001, r = 0.912, P < 0.001) and corresponding values calculated by the conventional ICG method. In 263 cases with chronic liver disease, the plasma disappearance rates calculated using this monitor (mean +/- S.D.) were 0.156 +/- 0.064 (n = 20) in the control group, 0.129 +/- 0.060 (n = 92) in the chronic hepatitis group, 0.048 +/- 0.025 (n = 59) in the cirrhosis group and 0.059 +/- 0.03, (n = 92) in the group with hepatocellular carcinoma. A significant difference in the plasma disappearance rate and blood retention ratios 15 min after injection of ICG using this system was observed between control cases and the chronic hepatitis and cirrhosis groups (P < 0.0001). In 36 cases, the time from injection to the appearance of ICG in the fingertip significantly decreased in the cirrhosis group (P < 0.01). The ICG Finger Monitor system was shown to be useful clinically as well as for research due to its accuracy and non-invasive nature.


Journal of Medical Virology | 1999

Clinical implications of coinfection with a novel DNA virus (TTV) in hepatitis C virus carriers on maintenance hemodialysis

Nobukazu Yuki; Michio Kato; Manabu Masuzawa; Hisashi Ishida; Takashi Inoue; Tsutomu Tabata; Yoshiki Matsushita; Hiroshi Kishimoto; Yutaka Sasaki; Norio Hayashi; Masatsugu Hori

A novel hepatitis‐associated DNA virus, designated as transfusion‐transmitted virus (TTV), was identified recently. We investigated the frequency of TTV viremia in hepatitis C virus (HCV) carriers on maintenance hemodialysis to determine whether TTV coinfection has any clinical relevance. The subjects were 50 hemodialysis patients who had been followed over 4 years after diagnosis of HCV infection. Stored serum samples derived from each patient every 12th month after enrollment were subjected to polymerase chain reaction to amplify TTV DNA and HCV RNA. At enrollment, TTV viremia was detected in 24 (48%) HCV‐positive patients irrespective of the number of previous blood transfusions and the duration of hemodialysis. The presence of TTV viremia had no relation to serum alanine aminotransferase (ALT) levels, HCV viremic levels or HCV genotypes. After enrollment, HCV infection persisted in all patients over the 4‐year follow‐up period, whereas spontaneous resolution of TTV infection was observed in 7 (29%) of the 24 TTV viremic cases (annual rate 7.3%, 95% confidence interval [CI] 0.8–25.5%). Evidence for TTV infection was found in 4 (15%) of the 26 TTV nonviremic patients (annual incidence 3.9%, 95% CI 0.1–19.6%). The relationship between the ALT profile and TTV infection during follow up was not evident. Active TTV coinfection occurs frequently in HCV carriers undergoing hemodialysis but exerts no biochemical or virological influence on the underlying hepatitis C. Lack of disease association and the frequent spontaneous resolution of infection suggest that the clinical significance of TTV infection remains unclear. J. Med. Virol. 59:431–436, 1999.


Journal of Clinical Gastroenterology | 2000

Reappraisal of Biochemical Hepatitis C Activity in Hemodialysis Patients

Nobukazu Yuki; Hisashi Ishida; Takashi Inoue; Tsutomu Tabata; Yoshiki Matsushita; Hiroshi Kishimoto; Michio Kato; Manabu Masuzawa; Yutaka Sasaki; Norio Hayashi; Masatsugu Hori

We reappraised biochemical hepatitis C activity in hemodialysis patients in comparison with normal controls. A total of 111 hemodialysis patients and 66 healthy volunteer blood donors with hepatitis C virus (HCV) infection were consecutively enrolled. Serum alanine aminotransferase (ALT) levels were normal (< or =45 U/L) in 103 (93%) hemodialysis patients and 34 (52%) donors (p < 0.001). HCV viremic levels were lower in the hemodialysis group (p = 0.044), with no difference in the HCV genotype prevalence. During two-year follow-up, 60 (67%) of 90 hemodialysis patients and 13 (26%) of 50 donors showed persistently normal ALT levels (p < 0.001). For hemodialysis patients, however, the upper normal limit of ALT activity was reset at 25 U/L corresponding to the mean + 2 x SD for the normalized ALT distribution in 400 control patients. The adjusted ALT levels were initially normal in 73 (66%) hemodialysis patients and persistently normal in 19 (21%). Thus, ALT levels were the same for the two groups. GB virus C (GBV-C)/hepatitis G virus (HGV) coinfection found only in the hemodialysis group (10/111) had no influence on the disease. A relationship was noted between low disease activity and female gender in both groups. These findings indicate that biochemical hepatitis C activity in hemodialysis patients is similar to that in normal controls and should be monitored based on adjusted ALT levels.


Cancer Chemotherapy and Pharmacology | 1992

Analysis of prognostic factors in patients with hepatocellular carcinoma treated by transcatheter arterial embolization

Keiji Yamamoto; Manabu Masuzawa; Michio Kato; Takumasa Okuyama; Kazuya Tamura

SummaryWe studied 240 cases of unresected hepatocellular carcinoma (HCC) using Coxs proportional hazard model to elucidate which factors would be closely related with the survival period after treatment by transcatheter arterial embolization (TAE) in the presence or absence of iodized oil. The results were as follows. The cumulative survival values obtained after TAE were 67.5% for 1 year, 32.0% for 2 years, and 20.5% for 3 years. The most significant prognostic factor was the degree of extension of tumor embolus in the portal vein or its branch. The tumor extension and the tumor type were also important factors. Age, sex, and AFP, HBsAg, and HCV Ab values were not useful as prognostic factors. This study provides a rational background for the selection of treatment for HCC. Furthermore, knowledge of the prognostic factors is useful for the management of patients, particularly in maintaining their good quality of life.


Journal of Hepatology | 1994

Serial quantitative analysis of serum hepatitis C virus RNA level in patients with acute and chronic hepatitis C

Masafumi Naito; Norio Hayashi; Hideki Hagiwara; Kazuhiro Katayama; Akinori Kasahara; Hideyuki Fusamoto; Michio Kato; Manabu Masuzawa; Takenobu Kamada

To examine changes in the serum level of hepatitis C virus RNA in acute and chronic phases of hepatitis C virus infection, we tested serial serum samples of six patients with acute hepatitis C (posttransfusion: three; sporadic: three) and 11 patients with chronic hepatitis C using a competitive reverse transcription and polymerase chain reaction assay. The internal standard consisted of known amounts of synthetic mutated RNA. No patient with acute hepatitis showed resolution during the follow-up period (24-57 weeks). In posttransfusion cases, titers of hepatitis C virus RNA (log10[hepatitis C virus RNA copies/ml serum]) rose to a high level (7.5-9.5) in the early phase of infection (4-12 weeks after the transfusions) in association with the first serum alanine aminotransferase peaks. Titers of hepatitis C virus RNA then decreased, while serum alanine aminotransferase levels fluctuated with multiple peaks. In sporadic cases, titers of hepatitis C virus RNA had already reached a high level (7.0-7.5) at the first alanine aminotransferase peaks 2-3 weeks after the clinical onset. In chronic hepatitis C virus infection, titers of hepatitis C virus RNA remained high for follow-up periods of 6-12 years in patients with chronic active hepatitis. These results indicate that the replication of hepatitis C virus rose to a high level in the early phase of infection and that a high replicative level of hepatitis C virus might be related with progression of liver disease in the chronic phase of infection.

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