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Dive into the research topics where Noritomo Shimada is active.

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Featured researches published by Noritomo Shimada.


Liver International | 2012

Contribution of ribavirin transporter gene polymorphism to treatment response in peginterferon plus ribavirin therapy for HCV genotype 1b patients.

Akihito Tsubota; Noritomo Shimada; Kai Yoshizawa; Tomomi Furihata; Rie Agata; Yoko Yumoto; Hiroshi Abe; Makiko Ika; Yoshihisa Namiki; Kan Chiba; Kiyotaka Fujise; Norio Tada; Yoshio Aizawa

Standard‐dose ribavirin is crucial for the standard‐of‐care treatment of chronic hepatitis C virus (HCV) infection. Equilibrative nucleoside transporter 1 (ENT1), encoded by SLC29A1 gene, is the main transporter that imports ribavirin into human hepatocytes. Aims:


Journal of Gastroenterology | 1997

Association between frequency of amino acid changes in core region of hepatitis B virus (HBV) and the presence of precore mutation in Japanese HBV carriers

Tatsunobu Karasawa; Takuji Shirasawa; Yasuhiko Okawa; Akira Kuramoto; Noritomo Shimada; Yoshio Aizawa; Mikio Zeniya; Gotaro Toda

To elucidate the relationship between the frequency of core mutations and precore mutation of hepatitis B virus (HBV) in Japanese HBV carriers, we investigated the nucleotide sequence of the precore/core region of HBV in 26 Japanese HBV carriers [15 who were HBe antigen-negative (HBeAg−) and 11 who were HBeAg-positive (HBeAg+)]. The number of amino acid changes (5.9±3.8) in the core region of HBV in HBeAg-carriers was significantly greater than that in the HBeAg+ carriers (1.5±1.0;P<0.005). The precore stop codon mutation was found in 93.3% of HBeAg-negative HBV carriers, while no precore mutation was found in the HBeAg-positive HBV carriers, suggesting that the frequency of core mutations may be associated with the presence of the precore stop codon mutation. However, there was no significant difference in the frequency of amino acid changes among HBeAg-HBV carriers. The mean number of core amino acid changes of liver cirrhosis patients, chronic active hepatitis patients, chronic persistent hepatitis patients, and asymptomatic carriers were 2.7±1.5, 6.0±2.2, 4.7±1.2, and 8.4±5.3, respectively. We detected hot spots for core mutations, which showed characteristic localizations and specific substitutions: Gly-87, Leu-97, and Thr-130 were detected exclusively in patients with chronic liver disease with or without HBeAg. To address further the relationship between frequency of core mutations and the presence of the precore stop codon mutation, we investigated the precore/core nucleotide sequence serially along with seroconversion in three patients with chronic hepatitis B in whom the hepatitis either became inactive or remained active after the seroconversion. Emergence of the precore stop codon mutation and a significant increase in core amino acid changes after seroconversion were noted in all three patients. Our results suggest a close association between the frequency of core amino acid changes and the presence of the precore stop codon mutation; some characteristic core mutations may be associated with the clinical course of chronic hepatitis B in Japanese patients.


Journal of Hepatology | 2017

Efficacy and tolerability of an IFN-free regimen with DCV/ASV for elderly patients infected with HCV genotype 1B

Hidenori Toyoda; Takashi Kumada; Toshifumi Tada; Noritomo Shimada; Koichi Takaguchi; Tomonori Senoh; Kunihiko Tsuji; Yoshihiko Tachi; Atsushi Hiraoka; Toshihide Shima; Takeshi Okanoue

BACKGROUND & AIMS Anti-hepatitis C virus (HCV) therapy by interferon (IFN)-free regimen with oral direct-acting antiviral drugs are tolerable in aged patients, with fewer adverse effects than IFN-based therapies. We investigated the efficacy and tolerability of an IFN-free anti-HCV therapy in extremely aged patients, as well as the survival benefit of sustained virologic response (SVR). METHODS Following IFN-free therapy with daclatasvir and asunaprevir, tolerability and SVR rate were compared between 115 HCV genotype 1-infected patients aged 80years or older, 151 patients in their 70s (⩾70 and <80years), and 115 patients under the age of 70. One-year mortality and morbidity in patients aged ⩾80years were compared between SVR patients and propensity score-matched patients with persistent HCV infection. RESULTS The SVR rate was 96.5% in patients ⩾80years, comparable to that in patients aged ⩾70 and <80years (95.4%) and patients aged <70years (93.9%). There were no differences in treatment discontinuation rate (2.6%, 1.3%, and 0.9%, respectively). One-year mortality was significantly lower in SVR patients (2.7%) than in patients with persistent HCV infection (15.3%, p=0.0016). Whereas 1-year mortality due to liver-related diseases was 8.1% in patients with persistent HCV infection who were aged ⩾80years, no SVR patients died from liver diseases within 1-year after the end of therapy. CONCLUSIONS IFN-free therapy for HCV infection was associated with high tolerability and antiviral efficacy, even in patients aged ⩾80years. In addition, there seemed to be a survival benefit from the eradication of HCV in this population. LAY SUMMARY IFN-free therapy with oral direct-acting antiviral drugs (daclatasvir and asunaprevir) for HCV infection showed similar tolerability and antiviral efficacy in patients aged ⩾80years as in younger patients (patients aged ⩾70 and <80years and patients aged <70years), with an SVR rate over 90% and no severe adverse effects. There was a survival benefit from the eradication of HCV even in patients aged ⩾80years.


Hepatology Research | 2017

Clinical Evaluation of Sofosbuvir/Ledipasvir in Chronic Hepatitis C Genotype 1 with and without Prior Daclatasvir/Asnaprevir Therapy.

Etsuko Iio; Noritomo Shimada; Koichi Takaguchi; Tomonori Senoh; Yuichiro Eguchi; Masanori Atsukawa; Akihito Tsubota; Hiroshi Abe; Keizo Kato; Atsunori Kusakabe; Tomokatsu Miyaki; Kentaro Matsuura; Kayoko Matsunami; Noboru Shinkai; Kei Fujiwara; Shunsuke Nojiri; Yasuhito Tanaka

This study explored treatment outcomes of sofosbuvir (SOF)/ledipasvir (LDV) therapy for chronic hepatitis C patients with and without prior daclatasvir (DCV)/asunaprevir (ASV) therapy.


Hepatology Research | 2017

Clinical evaluation of sofosbuvir/ledipasvir in patients with chronic hepatitis C genotype 1 with and without prior daclatasvir/asunaprevir therapy

Etsuko Iio; Noritomo Shimada; Koichi Takaguchi; Tomonori Senoh; Yuichiro Eguchi; Masanori Atsukawa; Akihito Tsubota; Hiroshi Abe; Keizo Kato; Atsunori Kusakabe; Tomokatsu Miyaki; Kentaro Matsuura; Kayoko Matsunami; Noboru Shinkai; Kei Fujiwara; Shunsuke Nojiri; Yasuhito Tanaka

This study explored treatment outcomes of sofosbuvir (SOF)/ledipasvir (LDV) therapy for chronic hepatitis C patients with and without prior daclatasvir (DCV)/asunaprevir (ASV) therapy.


World Journal of Gastroenterology | 2012

Several factors including ITPA polymorphism influence ribavirin-induced anemia in chronic hepatitis C

Akihito Tsubota; Noritomo Shimada; Hiroshi Abe; Kai Yoshizawa; Rie Agata; Yoko Yumoto; Makiko Ika; Yoshihisa Namiki; Keisuke Nagatsuma; Hiroshi Matsudaira; Kiyotaka Fujise; Norio Tada; Yoshio Aizawa

AIM To construct formulae for predicting the likelihood of ribavirin-induced anemia in pegylated interferon α plus ribavirin for chronic hepatitis C. METHODS Five hundred and sixty-one Japanese patients with hepatitis C virus genotype 1b who had received combination treatment were enrolled and assigned randomly to the derivation and confirmatory groups. Single nucleotide polymorphisms at or nearby ITPA were genotyped by real-time detection polymerase chain reaction. Factors influencing significant anemia (hemoglobin concentration < 10.0 g/dL at week 4 of treatment) and significant hemoglobin decline (declining concentrations > 3.0 g/dL at week 4) were analyzed using multiple regression analyses. Prediction formulae were constructed by significantly independent factors. RESULTS Multivariate analysis for the derivation group identified four independent factors associated with significant hemoglobin decline: hemoglobin decline at week 2 [P = 3.29 × 10(-17), odds ratio (OR) = 7.54 (g/dL)], estimated glomerular filtration rate [P = 2.16 × 10(-4), OR = 0.962 (mL/min/1.73 m(2))], rs1127354 (P = 5.75 × 10(-4), OR = 10.94) and baseline hemoglobin [P = 7.86 × 10(-4), OR = 1.50 (g/dL)]. Using the model constructed by these factors, positive and negative predictive values and predictive accuracy were 79.8%, 88.8% and 86.2%, respectively. For the confirmatory group, they were 83.3%, 91.0% and 88.3%. These factors were closely correlated with significant anemia. However, the model could not be constructed, because no patients with rs1127354 minor genotype CA/AA had significant anemia. CONCLUSION Reliable formulae for predicting the likelihood of ribavirin-induced anemia were constructed. Such modeling may be useful in developing individual tailoring and optimization of ribavirin dosage.


Journal of Gastroenterology and Hepatology | 2014

Impact of IL28B polymorphisms on 24‐week telaprevir‐based combination therapy for Asian chronic hepatitis C patients with hepatitis C virus genotype 1b

Akihito Tsubota; Noritomo Shimada; Masanori Atsukawa; Hiroshi Abe; Keizo Kato; Makiko Ika; Hiroshi Matsudaira; Keisuke Nagatsuma; Tomokazu Matsuura; Yoshio Aizawa

The aim of this study was to clarify which or how factors could influence the probability of sustained virological response (SVR) in 24‐week telaprevir‐based triple combination therapy for East Asian chronic hepatitis C patients infected with hepatitis C virus genotype 1b.


Oncology | 2011

Occurrence of Hepatocellular Carcinoma Was Not a Rare Event during and Immediately after Antiviral Treatment in Japanese HCV-Positive Patients

Tatsuo Kanda; Fumio Imazeki; Shigeru Mikami; Keizo Kato; Noritomo Shimada; Yutaka Yonemitsu; Tomoo Miyauchi; Makoto Arai; Keiichi Fujiwara; Akihito Tsubota; Nobuo Takada; Takayoshi Nishino; Motohide Takashi; Nobuyuki Sugiura; Michio Kimura; Kenichi Fukai; Osamu Yokosuka

Advanced chronic hepatitis C patients with sustained virolological response by antivirals remain at risk for hepatocellular carcinoma (HCC). We investigated the incidence of HCC during and immediately after peginterferon-alfa-2a and ribavirin (RBV) treatment in patients with chronic hepatitis C in Japan. HCC was detected in 8 of 238 patients during and after these treatments (mean follow-up period: 572 ± 252 days). In conclusion, occurrence of HCC is not a rare event during and immediately after peginterferon-alfa-2a plus RBV treatment. In cases with cirrhosis, higher α-fetoprotein levels, old age, or a previous history of HCC treatment, clinicians should be especially alert for the possible development of HCC during and immediately after peginterferon-alfa-2a and RBV treatment. Clinicians should regularly check for the possible development of HCC even in chronic hepatitis C patients under treatment.


Hepatology Research | 2017

Efficacy and safety of ombitasvir/paritaprevir/ritonavir in dialysis patients with genotype 1b chronic hepatitis C

Masanori Atsukawa; Akihito Tsubota; Yohei Koushima; Tadashi Ikegami; Kouji Watanabe; Noritomo Shimada; Shinichi Sato; Keizo Kato; Hiroshi Abe; Tomomi Okubo; Taeang Arai; Norio Itokawa; Chisa Kondo; Shigeru Mikami; Toru Asano; Yoshimichi Chuganji; Yasushi Matsuzaki; Katsuhiko Iwakiri

From a pharmacokinetic viewpoint, the use of ombitasvir/paritaprevir/ritonavir, one of the standards of care for genotype 1b chronic hepatitis C in Japan, could be possible in patients with impaired renal function. The aim of this study was to assess the efficacy and safety of this combination that have not yet been addressed in patients undergoing dialysis.


Journal of Medical Virology | 2013

New Proposal for Response-Guided Peg-Interferon- Plus-Ribavirin Combination Therapy for Chronic Hepatitis C Virus Genotype 2 Infection

Hiroshi Abe; Yuta Aida; Haruya Ishiguro; Kai Yoshizawa; Nobuyoshi Seki; Tamihiro Miyazaki; Munenori Itagaki; Satoshi Sutoh; Makiko Ika; Keizo Kato; Noritomo Shimada; Akihito Tsubota; Yoshio Aizawa

This study aimed to determine the most suitable duration of pegylated‐interferon (Peg‐IFN)‐plus‐ribavirin combination therapy in patients infected with hepatitis C virus (HCV) genotype 2 who had not achieved rapid virological response (serum HCV RNA disappearance after 4 weeks of therapy). HCV genotype 2 patients (n = 182) with a high viral load received >80% of the standard Peg‐IFN‐plus‐ribavirin dose for at least 24 weeks, and their final virological responses were studied. Patients were classified into “rapid virological response” and “non‐rapid virological response” groups. The non‐rapid virological response group was further divided into a “virological response at 8 weeks” (serum HCV RNA disappearance after 8 weeks of therapy) and a “non‐virological response at 8 weeks” group. Factors related to rapid virological response and optimal therapy duration in the non‐rapid virological response group were evaluated. Multivariate logistic regression analysis showed that subtype HCV genotype 2a (P = 0.0015) and low concentration of pretreatment serum HCV RNA (P = 0.0058) were independent factors in a rapid virological response. In the virological response at 8 weeks group, the sustained virological response rate after 24 weeks of therapy was significantly lower than after 36 weeks (P = 0.044) or after 48 weeks (P = 0.006), and was similar for 36‐ and 48‐weeks. The cost for achieving (CAS) one sustained virological response was lowest with 36‐week therapy. Prolongation of Peg‐IFN‐plus‐ribavirin combination therapy to 36 weeks is suitable for achieving virological response at 8 weeks, given the high, sustained virological response rate and cost benefit. J. Med. Virol. 85:1523–1533, 2013.

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Akihito Tsubota

Jikei University School of Medicine

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Yoshio Aizawa

Jikei University School of Medicine

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Keizo Kato

Jikei University School of Medicine

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