Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Norie Yamada is active.

Publication


Featured researches published by Norie Yamada.


Clinical Infectious Diseases | 2013

High Levels of Hepatitis B Virus After the Onset of Disease Lead to Chronic Infection in Patients With Acute Hepatitis B

Hiroshi Yotsuyanagi; Kiyoaki Ito; Norie Yamada; Hideaki Takahashi; Chiaki Okuse; Kiyomi Yasuda; Michihiro Suzuki; Kyoji Moriya; Masashi Mizokami; Yuzo Miyakawa; Kazuhiko Koike

BACKGROUND Some patients with acute hepatitis B virus (HBV) infection develop chronic infection. However, the method for identifying these patients has not been established. METHODS We followed 215 Japanese patients with acute HBV infection until the clearance of hepatitis B surface antigen (HBsAg) or the development of chronic infection. Levels of HBsAg and HBV DNA were serially monitored from the onset. RESULTS Of the 215 patients, 113 (52.5%) possessed HBV genotype A, 26 (12.0%) genotype B, and 73 (34.0%) genotype C. Twenty-one of the 215 (9.8%) developed chronic infection, with the persistence of HBsAg for >6 months. The rate of chronicity of genotype A, B, and C was 12.4%, 3.8%, and 8.2%. Of the 21 patients, only 6 (2.8%) patients, including 5 with genotype A, failed to clear HBsAg within 12 months. Levels of HBsAg at 12 weeks and HBV DNA at 4 weeks were useful for distinguishing the patients who became chronic from those who did not (P < .001 and P < .001, respectively). Likewise, the levels of HBsAg at 12 weeks and HBV DNA at 8 weeks were useful for discriminating between the patients who lost HBsAg within 12 months and those who did not (P < .01 and P < .05, respectively). CONCLUSIONS In acute HBV infection, clearance of HBV may happen between 6 and 12 months from the onset. Only those who fail to clear HBV within 12 months from the onset may develop chronic infection.


Journal of Medical Virology | 2017

Impact of resistance-associated variant dominancy on treatment in patients with HCV genotype 1b receiving daclatasvir/asunaprevir.

Hiroki Ikeda; Tsunamasa Watanabe; Chiaki Okuse; Nobuyuki Matsumoto; Toshiya Ishii; Norie Yamada; Ryuta Shigefuku; Nobuhiro Hattori; Kotaro Matsunaga; Hiroyasu Nakano; Tetsuya Hiraishi; Minoru Kobayashi; Kiyomi Yasuda; Hiroyuki Yamamoto; Hiroshi Yasuda; Masayuki Kurosaki; Namiki Izumi; Hiroshi Yotsuyanagi; Michihiro Suzuki; Fumio Itoh

Sustained virological responses (SVR) by daclatasvir (DCV) and asunaprevir (ASV) therapy for genotype 1b hepatitis C virus (HCV) infected patients has been significantly affected by pre‐existence of Y93 H resistance‐associated variants (RAVs) in the non‐structural protein 5A (NS5A) region. The aim of this study was to elucidate the dominancy of naturally occurring RAVs in viral quasispecies on treatment outcomes in patients with HCV. In total, 138 patients were prospectively selected from 152 patients treated with DCV and ASV, where evaluation of treatment outcomes at 12 weeks post‐treatment was possible. Pre‐treatment RAVs in the non‐structural protein 3 and NS5A regions were detected by polymerase chain reaction (PCR)‐Invader assays, and the ratio of Y93H RAVs in viral quasispecies was measured by quantitative PCR‐Invader assay. Among 25 patients detected the Y93H RAV, the Y93H ratio was 1–25% in 5 patients, 26–75% in 7 patients, and ≥76% in 13 patients. Overall, SVR at 12 weeks after the completion of treatment (SVR12) was 91% (125/138), and those with Y93H ratios of <1%, 1–25%, 26–75%, and ≥76% were 99%, 100%, 71%, and 23%, respectively. Thus, the SVR12 decreased as the HCV Y93H ratio increased (P < 0.0001). The dominancy of pre‐treatment RAVs of DCV and ASV affected its treatment outcomes, suggesting that evaluating the dominancy of HCV RAVs could be required for every other direct‐acting antiviral agent treatments. J. Med. Virol. 89:99–105, 2017.


Hepatology Communications | 2017

Resistance mutations of hepatitis B virus in entecavir-refractory patients

Norie Yamada; Ryuichi Sugiyama; Sayuri Nitta; Asako Murayama; Minoru Kobayashi; Chiaki Okuse; Michihiro Suzuki; Kiyomi Yasuda; Hiroshi Yotsuyanagi; Kyoji Moriya; Kazuhiko Koike; Takaji Wakita; Takanobu Kato

The emergence of resistance mutations in the reverse transcriptase gene of hepatitis B virus (HBV) is associated with treatment failure. Entecavir (ETV) is one of the most potent anti‐HBV reagents; it has a very low resistance rate and is used as the first‐line treatment for chronic hepatitis B. In this study, we isolated HBVs in 4 ETV‐refractory patients (2 with viral breakthrough, 1 with partial virological response, and 1 with flare‐up) and assessed ETV resistance using replication‐competent 1.38‐fold HBV genome‐length molecular clones. The full genome sequences of infected HBVs in ETV‐refractory patients were determined. The HBV molecular clones were generated with the patient‐derived sequences. After transfection of these molecular clones into HepG2 cells, viral replications and ETV susceptibilities were evaluated by measuring the amount of intracellular core‐particle‐associated HBV DNA using Southern blotting and real‐time polymerase chain reaction. Among these cases, ETV‐resistant variants were detected in 2 patients with viral breakthrough and responsible amino acid mutations in reverse transcriptase were successfully identified in these variants. No ETV‐resistant mutation was detected in the other cases. The identified ETV‐resistant mutations did not confer resistance to tenofovir disoproxil fumarate. Conclusion: The HBV replication model with patient‐derived sequences is useful for assessing replication efficiency, susceptibility to anti‐HBV reagents, and responsible resistance mutations and can aid in choosing the appropriate treatment strategy for treatment‐failure cases of chronic hepatitis B. (Hepatology Communications 2017;1:110‐121)


World Journal of Gastroenterology | 2014

Acute hepatitis B of genotype H resulting in persistent infection

Norie Yamada; Ryuta Shigefuku; Ryuichi Sugiyama; Minoru Kobayashi; Hiroki Ikeda; Hideaki Takahashi; Chiaki Okuse; Michihiro Suzuki; Fumio Itoh; Hiroshi Yotsuyanagi; Kiyomi Yasuda; Kyoji Moriya; Kazuhiko Koike; Takaji Wakita; Takanobu Kato

A 47-year-old man presented with general fatigue and dark urine. The laboratory data showed increased levels of hepatic transaminases. The patient was positive for hepatitis B virus (HBV) markers and negative for anti-human immunodeficiency virus. The HBV-DNA titer was set to 7.7 log copies/mL. The patient was diagnosed with acute hepatitis B. The HBV infection route was obscure. The serum levels of hepatic transaminases decreased to normal ranges without any treatment, but the HBV-DNA status was maintained for at least 26 mo, indicating the presence of persistent infection. We isolated HBV from the acute-phase serum and determined the genome sequence. A phylogenetic analysis revealed that the isolated HBV was genotype H. In this patient, the elevated peak level of HBV-DNA and the risk alleles at human genome single nucleotide polymorphisms s3077 and rs9277535 in the human leukocyte antigen-DP locus were considered to be risk factors for chronic infection. This case suggests that there is a risk of persistent infection by HBV genotype H following acute hepatitis; further cases of HBV genotype H infection must be identified and characterized. Thus, the complete determination of the HBV genotype may be essential during routine clinical care of acute hepatitis B outpatients.


Hepatology Research | 2012

Changes in levels of hepatitis B virus markers in patients positive for low‐titer hepatitis B surface antigen

Chiaki Okuse; Hiroshi Yotsuyanagi; Norie Yamada; Hiroki Ikeda; Minoru Kobayashi; Yasunobu Fukuda; Hideaki Takahashi; Kotaro Matsunaga; Nobuyuki Matsumoto; Masaru Okamoto; Toshiya Ishii; Akira Sato; Kazuhiko Koike; Michihiro Suzuki; Fumio Itoh

Aim:  Recently, patients positive for the low‐titer hepatitis B surface antigen (HBsAg) have been found occasionally owing to the increase in the accuracy of detection methods. The aim of this study is to clarify the clinical status of acute hepatitis B virus (HBV) infection in patients positive for low‐titer HBsAg.


Cancer Letters | 2018

Dysregulation of miRNA in chronic hepatitis B is associated with hepatocellular carcinoma risk after nucleos(t)ide analogue treatment

Hideki Wakasugi; Hideaki Takahashi; Takeshi Niinuma; Hiroshi Kitajima; Ritsuko Oikawa; Naoki Matsumoto; Yuko Takeba; Takehito Otsubo; Masayuki Takagi; Yasushi Ariizumi; Michihiro Suzuki; Chiaki Okuse; Shogo Iwabuchi; Masayuki Nakano; Noriyuki Akutsu; Jong-Hon Kang; Takeshi Matsui; Norie Yamada; Hajime Sasaki; Eiichiro Yamamoto; Masahiro Kai; Yasushi Sasaki; Shigeru Sasaki; Yasuhito Tanaka; Hiroshi Yotsuyanagi; Takeya Tsutsumi; Hiroyuki Yamamoto; Takashi Tokino; Hiroshi Nakase; Hiromu Suzuki

Hepatitis B virus (HBV) infection is a major cause of hepatocellular carcinoma (HCC). Nucleos(t)ide analogue (NA) therapy effectively reduces the incidence of HCC, but it does not completely prevent the disease. Here, we show that dysregulation of microRNAs (miRNAs) is involved in post-NA HCC development. We divided chronic hepatitis B (CHB) patients who received NA therapy into two groups: 1) those who did not develop HCC during the follow-up period after NA therapy (no-HCC group) and 2) those who did (HCC group). miRNA expression profiles were significantly altered in CHB tissues as compared to normal liver, and the HCC group showed greater alteration than the no-HCC group. NA treatment restored the miRNA expression profiles to near-normal in the no-HCC group, but it was less effective in the HCC group. A number of miRNAs implicated in HCC, including miR-101, miR-140, miR-152, miR-199a-3p, and let-7g, were downregulated in CHB. Moreover, we identified CDK7 and TACC2 as novel target genes of miR-199a-3p. Our results suggest that altered miRNA expression in CHB contributes to HCC development, and that improvement of miRNA expression after NA treatment is associated with reduced HCC risk.


Antiviral Research | 2018

Vitamin D derivatives inhibit hepatitis C virus production through the suppression of apolipoprotein

Asako Murayama; Hiroshi Saitoh; Akiko Takeuchi; Norie Yamada; Takuya Matsumura; Masaaki Shiina; Masamichi Muramatsu; Takaji Wakita; Michio Imawari; Takanobu Kato

ABSTRACT Supplementation with vitamin D (VD) has been reported to improve the efficacy of interferon‐based therapy for chronic hepatitis C. We found that 25‐hydroxyvitamin D3 (25‐(OH)D3), one of the metabolites of VD, has antiviral effects by inhibiting the infectious virus production of the hepatitis C virus (HCV). In this study, to clarify the underlying mechanisms of the anti‐HCV effects, we searched VD derivatives that have anti‐HCV effects and identified the common target molecule in the HCV life cycle by using an HCV cell culture system. After infection of Huh‐7.5.1 cells with cell culture‐generated HCV, VD derivatives were added to culture media, and the propagation of HCV was assessed by measuring the HCV core antigen levels in culture media and cell lysates. To determine the step in the HCV life cycle affected by these compounds, the single‐cycle virus production assay was used with a CD81‐negative cell line. Of the 14 structural derivatives of VD, an anti‐HCV effect was detected in 9 compounds. Cell viability was not affected by these effective compounds. The 2 representative VD derivatives inhibited the infectious virus production in the single‐cycle virus production assay. Treatment with these compounds and 25‐(OH)D3 suppressed the expression of apolipoprotein A1 and C3, which are known to be involved in infectious virus production of HCV, and the knockdown of these apolipoproteins reduced infectious virus production. In conclusion, we identified several compounds with anti‐HCV activity by screening VD derivatives. These compounds reduce the infectious virus production of HCV by suppressing the expression of apolipoproteins in host cells. HighlightsWe identified VD derivatives with anti‐HCV activity by a screening of structural derivatives of 1&agr;,25‐dihydroxy VD3.The anti‐HCV effect of VD derivatives is not associated with the binding affinity to VDR and the signaling activation.The VD derivatives reduce the infectious virus production of HCV by suppressing the expression of apolipoproteins.


Kanzo | 2011

Evaluation of usefulness of hepatitis B vaccination at St. Marianna University School of Medicine Hospital and related facilities

Chiaki Okuse; Hiroshi Yotsuyanagi; Norie Yamada; Kiyomi Yasuda; Masatoshi Hara; Takahide Matsuda; Junko Aono; Michihiro Suzuki; Fumio Itoh; Kazuhiko Koike


Kanzo | 2010

Duration of HBs antigenemia in patients with acute hepatitis B

Norie Yamada; Hiroshi Yotsuyanagi; Chiaki Okuse; Kiyomi Yasuda; Michihiro Suzuki; Kazuhiko Koike


Kanzo | 2013

A review of the cases with transient sero-positive HCV-RNA during antiviral treatment and after susutained virological response in chronic hepatitis C

Yasunobu Fukuda; Yoshihiko Nagase; Sarika Kitagawa; Yosuke Michikawa; Tetsuya Hiraishi; Daisuke Kumon; Seiyo Ko; Satoshi Baba; Norie Yamada; Minoru Kobayashi; Hiroki Ikeda; Hideaki Takahashi; Kotaro Matsunaga; Nobuyuki Matsumoto; Chiaki Okuse; Hiroshi Yotsuyanagi; Michihiro Suzuki

Collaboration


Dive into the Norie Yamada's collaboration.

Top Co-Authors

Avatar

Chiaki Okuse

St. Marianna University School of Medicine

View shared research outputs
Top Co-Authors

Avatar

Michihiro Suzuki

St. Marianna University School of Medicine

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Hideaki Takahashi

St. Marianna University School of Medicine

View shared research outputs
Top Co-Authors

Avatar

Minoru Kobayashi

St. Marianna University School of Medicine

View shared research outputs
Top Co-Authors

Avatar

Kiyomi Yasuda

National Defense Medical College

View shared research outputs
Top Co-Authors

Avatar

Fumio Itoh

St. Marianna University School of Medicine

View shared research outputs
Top Co-Authors

Avatar

Hiroki Ikeda

St. Marianna University School of Medicine

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Nobuyuki Matsumoto

St. Marianna University School of Medicine

View shared research outputs
Researchain Logo
Decentralizing Knowledge