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Dive into the research topics where Shozo Miyake is active.

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Featured researches published by Shozo Miyake.


Nephron | 1998

Interferon Therapy for Chronic Hepatitis C in Hemodialysis Patients: Increased Serum Levels of Interferon

Masakatsu Uchihara; Namiki Izumi; Yoshinori Sakai; Tsunehito Yauchi; Shozo Miyake; Takahiro Sakai; Takashi Akiba; Fumiaki Marumo; Chifumi Sato

Background/Aims: The efficacy and side effects of interferon (IFN) therapy have not been well clarified in hemodialysis patients with chronic hepatitis C. Methods: In 6 of 9 hemodialysis patients with chronic hepatitis C, 3 million units (MU) or 6 MU of recombinant IFN-α2b or natural IFN-α were administered intramuscularly daily for the first 2 weeks, followed by three times a week for 22 weeks. In the remaining 3 patients, 3 MU of IFN-α2b were given three times a week for 24 weeks. Serum concentrations of IFN-α2b were measured sequentially after the injection of interferon. Responders were defined as the patients with normal serum aminotransferase and negative serum HCV RNA 6 months after the cessation of IFN therapy. Results: Three of the 6 patients who were administered IFN daily in the first 2 weeks were responders, while the other 3 withdrew from the therapy due to serious adverse events such as depression, loss of consciousness and persistence of high-grade fever. Serious adverse events were not observed in the 3 patients without daily administration. Half-lives of IFN-α2b in hemodialysis patients were significantly longer than those in nonuremic patients (10.0 vs. 6.0 h, p < 0.05). Moreover, the areas under the serum concentration curve of the hemodialysis patients were significantly larger than those of nonuremic patients (756 ± 223 vs. 324 ± 223 IU·h/ml, p < 0.05), despite the fact that the dose of IFN-α administered to hemodialysis patients was half that administered to nonuremic patients. Conclusions: In hemodialysis patients with chronic hepatitis C, pharmacokinetic parameters of IFN may be different from those in nonuremic patients, and daily or high-dose administration of IFN may lead to serious adverse events in those patients.


Digestive Diseases and Sciences | 1996

Hepatic iron contents and response to interferon-α in patients with chronic hepatitis C: Relationship to genotypes of hepatitis C virus

Namiki Izumi; Nobuyuki Enomoto; Masakatsu Uchihara; Takeshi Murakami; Keiichi Ono; Osamu Noguchi; Shozo Miyake; Toshihiko Nouchi; Kiyoshi Fujisawa; Fumiaki Marumo; Chifumi Sato

Recent reports have shown that response to interferon treatment is influenced by hepatic iron contents in patients with chronic hepatitis C. In those reports, however, hepatitis C virus (HCV) genotypes and serum HCV-RNA levels were not examined. The aim of the present study was to investigate whether hepatic iron contents influence the response to interferon in patients with chronic hepatitis C and whether HCV genotypes and serum HCV-RNA levels play a role in this relationship. Among 65 patients with chronic hepatitis C, hepatic iron contents were significantly high in patients with a history of excess drinking of alcohol (more than 80 g/day) compared to those without, and significantly low in female patients before menopause. Having excluded these patients, hepatic iron contents were significantly higher in patients with genotype 1b infection than those with genotype 2a and 2b infection. There was no significant correlation between hepatic iron contents and plasma HCV-RNA levels. Among the patients with genotype 1b infection, hepatic iron contents were significantly lower in the responders to interferon than those in the nonresponders (429 ± 100 vs 875 ± 110 µg/g liver,P<0.05). From these results, it is concluded that response to interferon is mainly influenced by HCV genotypes, while hepatic iron contents may play an important role in response to interferon in patients with genotype 1b infection.


Gastroenterology | 2008

Potential Relevance of Cytoplasmic Viral Sensors and Related Regulators Involving Innate Immunity in Antiviral Response

Yasuhiro Asahina; Namiki Izumi; Itsuko Hirayama; Tomohiro Tanaka; Mitsuaki Sato; Yutaka Yasui; Nobutoshi Komatsu; Naoki Umeda; Takanori Hosokawa; Ken Ueda; Kaoru Tsuchiya; H. Nakanishi; Jun Itakura; Masayuki Kurosaki; Nobuyuki Enomoto; Megumi Tasaka; Naoya Sakamoto; Shozo Miyake

BACKGROUND & AIMS Clinical significance of molecules involving innate immunity in treatment response remains unclear. The aim is to elucidate the mechanisms underlying resistance to antiviral therapy and predictive usefulness of gene quantification in chronic hepatitis C (CH-C). METHODS We conducted a human study in 74 CH-C patients treated with pegylated interferon alpha-2b and ribavirin and 5 nonviral control patients. Expression of viral sensors, adaptor molecule, related ubiquitin E3-ligase, and modulators were quantified. RESULTS Hepatic RIG-I, MDA5, LGP2, ISG15, and USP18 in CH-C patients were up-regulated at 2- to 8-fold compared with nonhepatitis C virus patients with a relatively constitutive Cardif. Hepatic RIG-I, MDA5, and LGP2 were significantly up-regulated in nonvirologic responders (NVR) compared with transient (TR) or sustained virologic responders (SVR). Cardif and RNF125 were negatively correlated with RIG-I and significantly suppressed in NVR. Differences among clinical responses in RIG-I/Cardif and RIG-I/RNF125 ratios were conspicuous (NVR/TR/SVR = 1.3:0.6:0.4 and 2.3:1.3:0.8, respectively). Like viral sensors, ISG15 and USP18 were significantly up-regulated in NVR (4-fold and 2.3-fold, respectively). Multivariate and receiver operator characteristic analyses revealed higher RIG-I/Cardif ratio, ISG15, and USP18 predicted NVR. Lower Cardif in NVR was confirmed by its protein level in Western blot. Also, transcriptional responses in peripheral blood mononuclear cells to the therapy were rapid and strong except for Cardif in not only a positive (RIG-I, ISG15, and USP18) but also in a negative regulatory manner (RNF125). CONCLUSIONS NVR may have adopted a different equilibrium in their innate immune response. High RIG-I/Cardif and RIG-I/RNF125 ratios and ISG15 and USP18 are useful in identifying NVR.


Journal of Hepatology | 2008

The presence of steatosis and elevation of alanine aminotransferase levels are associated with fibrosis progression in chronic hepatitis C with non-response to interferon therapy

Masayuki Kurosaki; Kotaro Matsunaga; Itsuko Hirayama; Tomohiro Tanaka; Mitsuaki Sato; Nobutoshi Komatsu; Naoki Umeda; Takanori Hosokawa; Ken Ueda; Kaoru Tsuchiya; H. Nakanishi; Jun Itakura; Yasuhiro Asahina; Shozo Miyake; Nobuyuki Enomoto; Namiki Izumi

BACKGROUND/AIMS Interferon (IFN) therapy leads to regression of hepatic fibrosis in chronic hepatitis C patients who achieve a sustained virologic response (SVR), while the beneficial effect is limited in those who fail to do so. The aim of the present study was to define factors associated with progression of fibrosis in patients who do not achieve a SVR. METHODS Fibrosis staging scores were compared between paired liver biopsies before and after IFN in 97 chronic hepatitis C patients who failed therapy. The mean interval between biopsies was 5.9 years. Factors associated with progression of fibrosis were analyzed. RESULTS Fibrosis progressed in 23%, remained unchanged in 47% and regressed in 29%. Steatosis and a high average alanine aminotransferase (ALT) between biopsies were independent factors for progression of fibrosis with risk ratios of 5.53 and 4.48, respectively. Incidence and yearly rate of progression of fibrosis was 64% and 0.22+/-0.29 fibrosis units per year in those with both risk factors compared to 8% and -0.04+/-0.17 fibrosis units per year in those negative for both factors. CONCLUSIONS Hepatic steatosis and elevated ALT levels are risk factors for progression of fibrosis in chronic hepatitis C patients who fail to achieve a SVR to IFN therapy and therefore may be therapeutic targets to halt the potentially progressive disease.


Hepatology Research | 2003

Assessment of Kupffer cells by ferumoxides-enhanced MR imaging is beneficial for diagnosis of hepatocellular carcinoma: comparison of pathological diagnosis and perfusion patterns assessed by CT hepatic arteriography and CT arterioportography

Yasuhiro Asahina; Namiki Izumi; Masakatsu Uchihara; Osamu Noguchi; Ken Ueda; Kazunari Inoue; Yuki Nishimura; Kaoru Tsuchiya; Kosei Hamano; Jun Itakura; Yoshiro Himeno; Morio Koike; Shozo Miyake

To investigate the clinical significance of the radiographic assessment of Kupffer cells and hemodynamics in the diagnosis of hepatocellular nodules, both magnetic resonance (MR) imaging enhanced by ferumoxides and CT hepatic arteriography (CTHA)/CT arterioportography (CTAP) were undertaken for 118 patients with 158 primary nodular hepatocellular lesions. The radiographic findings were analyzed in the context of the pathological diagnosis. Among nodules presumed to be pre- or early HCC by CTHA/CTAP, all 13 hyperintense nodules identified by MR imaging (MRI) were found pathologically to be hepatocellular carcinoma (HCC). In contrast, in 14 hypointense nodules, no advanced (moderately or poorly differentiated) HCC was pathologically identified and none of these progressed to advanced HCC during the follow up period (mean: 24 months). Instead, 78% of these cases were pathologically confirmed as dysplastic nodules. For the 16 lesions undetectable by CTHA/CTAP, four of eight (50%) hypointense nodules turned out to be dysplastic nodules and one hyperintense lesion was HCC. Signal intensity by ferumoxides-enhanced MRI showed a strong correlation with the increase or decrease of Kupffer cells assessed by immunohistochemistry. Assessment of Kupffer cells by ferumoxides-enhanced MRI is beneficial for the accurate diagnosis of primary hepatocellular nodules that are considered borderline or early stage HCC by their hemodynamic profile.


Journal of Hepatology | 2003

Interferon-stimulated gene expression and hepatitis C viral dynamics during different interferon regimens

Yasuhiro Asahina; Namiki Izumi; Masakatsu Uchihara; Osamu Noguchi; Yuki Nishimura; Kazunari Inoue; Ken Ueda; Kaoru Tsuchiya; Kosei Hamano; Jun Itakura; Shozo Miyake

BACKGROUND/AIMS To address the molecular mechanism for enhanced antiviral efficacy associated with a frequent dosing of interferon (IFN)-beta. METHODS Serum hepatitis C viral (HCV) dynamics, double-stranded RNA-activated protein kinase (PKR) mRNA and MxA mRNA levels in peripheral blood mononuclear cells (PBMC) were analyzed serially in 140 patients who were randomly assigned to a twice daily (3 MU bid) or once daily (6 MU qd) administration group. RESULTS In twice daily group, the rate of HCV decline during the second phase was 2-fold greater than in the once daily group (P=0.04). Peak PKR and MxA gene expression levels in the first phase (observed 4 h after a single administration) were 2-fold higher in the once daily group. However, the expression in the second phase was maintained at a significantly higher level in the twice daily group. Initial and peak expression levels were related to initial viral load. Basal expressions in PBMC were significantly correlated with those in the liver tissue (PKR, r=0.81; MxA, r=0.75, respectively, P<0.0001). CONCLUSIONS Our data suggest that elimination of HCV-infected cells is enhanced by twice daily dosing of IFN-beta, and that this enhanced effect is associated with a higher intracellular expression of PKR and MxA during the second phase.


Nephron | 1990

Adult Fanconi Syndrome Secondary to ĸ-Light Chain Myeloma: Improvement of Tubular Functions after Treatment for Myeloma

Shinichi Uchida; Osamu Matsuda; Takanori Yokota; Tamiko Takemura; Ryoichi Ando; Hiroyoshi Kanemitsu; Hiroyuki Hamaguchi; Shozo Miyake; Fumiaki Marumo

A 66-year-old man with kappa-light chain multiple myeloma had adult Fanconi syndrome. Renal tubular transport abnormalities consisted of renal tubular acidosis, renal glycosuria, aminoaciduria, phosphaturia and renal hypouricemia. After therapy for multiple myeloma, urinary Bence Jones protein became undetectable, and all these renal tubular abnormalities except urate wasting were corrected. Histological examination revealed electron-dense tubular and rod-like deposits in proximal tubular epithelium. This clinical observation suggests that the renal tubular transport defects were secondary to the myeloma process, possibly due to Bence Jones proteinuria.


American Journal of Nephrology | 1990

Polycystic kidney of autosomal dominant inheritance, polycystic liver and congenital hepatic fibrosis in a single kindred

Osamu Matsuda; Terukuni Ideura; Toshio Shinoda; Tatsuo Shiigai; Hiroyuki Takeuchi; Chen Wei-Chia; Shozo Miyake

A family with clear evidence of concomitant congenital hepatic fibrosis, polycystic liver and adult-type polycystic kidney is reported. The autosomal dominant inheritance of polycystic kidney in association with either liver cyst or hepatic fibrosis in this family suggests that various combinations of hepatic and renal fibrocystic lesions are possible to occur. Additionally, in the proband a very rare association of congenital hepatic fibrosis and cerebral aneurysm was present.


Journal of Hepatology | 2003

Core promoter/pre-core mutations are associated with lamivudine-induced HBeAg loss in chronic hepatitis B with genotype C

Yasuhiro Asahina; Namiki Izumi; Masakatsu Uchihara; Osamu Noguchi; Yuki Nishimura; Kazunari Inoue; Ken Ueda; Kaoru Tsuchiya; Kosei Hamano; Jun Itakura; Shozo Miyake

BACKGROUND/AIMS To clarify the factors associated with the efficacy of lamivudine. METHODS Variables including basic core promoter (BCP) and pre-core (PreC) mutations were evaluated in 60 chronic hepatitis B e antigen (HBeAg)-positive patients with genotype C. Thirty patients were treated with lamivudine and the remaining 30 patients were age- and sex-matched controls. RESULTS Severe fibrosis was significantly more frequent in patients with the BCP-mutant/PreC-wild (MW) and BCP-mutant/PreC-mutant (MM) patterns compared to BCP-wild/PreC-wild (WW) pattern (P=0.02). The cumulative rates of HBeAg loss at 6, 12 and 18 months were significantly higher in the lamivudine group (14.2, 36.3, and 60.9%) compared with the control group (17.6, 17.6, and 24.5%, P=0.03), and was especially pronounced in patients with the MW pattern (P=0.04). The rate of lamivudine-related HBeAg loss was significantly lower in patients with the WW pattern (P=0.03). Factors correlating with HBeAg loss were histological fibrosis and activity, hepatitis B virus-DNA levels, BCP/PreC mutation and lamivudine therapy. Multivariate analysis revealed BCP/PreC mutations and fibrosis were independent factors for HBeAg loss. CONCLUSIONS With specific reference to the genotype C, we found earlier HBeAg loss was expected in patients carrying MM and MW patterns, while the efficacy of lamivudine was limited in patients with the WW pattern.


Intervirology | 2004

A Comparison of the Exponential Decay Slope between PEG-IFN alfa-2b/Ribavirin and IFN alfa-2b/Ribavirin Combination Therapy in Patients with Chronic Hepatitis C Genotype 1b Infection and a High Viral Load

Namiki Izumi; Yasuhiro Asahina; Masayuki Kurosaki; Masakatsu Uchihara; Yuki Nishimura; Kazunari Inoue; Ken Ueda; Kaoru Tsuchiya; Kousei Hamano; Jun Itakura; Shozo Miyake

Objectives: A high virological response rate can often be shown to be obtained with PEG-IFN α-2b and ribavirin combination therapy in chronic hepatitis C patients. Viral dynamics have been utilized for the evaluation of antiviral effects, especially the exponential second decay slope, which represents the elimination of infected cells. Methods: Forty-nine patients were randomly assigned to the IFN α-2b group (n = 26) or the PEG-IFN α-2b group (n = 23). Ribavirin was administered equally to both groups. Measuring the serum concentration of HCVRNA, the exponential viral decay during phase 1 and 2 was calculated. Results: The exponential decay slope in phase 2 during the first 2 weeks was greater in the IFN α-2b group than in the PEG-IFN α-2b group; however, from weeks 3 to 4, it was greater in the PEG-IFN α-2b group than in the IFN α-2b group. Interestingly, in the PEG-IFN α-2b group, the exponential decay slope was greater from weeks 3 to 4 after initiating combination therapy than during the weeks 1–2 (p < 0.01), despite administration of the same PEG-IFN α-2b dose (1.5 µg/kg once weekly). Conclusions: In PEG-IFN α-2b and ribavirin combination therapy, elimination of infected cells may be pronounced following an increase in serum ribavirin concentration in chronic hepatitis C patients with genotype 1b infection and a high viral load.

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Namiki Izumi

Tokyo Medical and Dental University

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Masakatsu Uchihara

Tokyo Medical and Dental University

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Yasuhiro Asahina

University of Connecticut Health Center

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Osamu Noguchi

Tokyo Medical and Dental University

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Jun Itakura

University of Yamanashi

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Chifumi Sato

Tokyo Medical and Dental University

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Nobuhiko Kanazawa

Tokyo Medical and Dental University

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Kosei Hamano

Tokyo Medical and Dental University

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