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Dive into the research topics where Yoji Ishizu is active.

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Featured researches published by Yoji Ishizu.


Liver International | 2010

Efficacy of peginterferon-α-2b plus ribavirin in patients aged 65 years and older with chronic hepatitis C.

Takashi Honda; Yoshiaki Katano; Junichi Shimizu; Yoji Ishizu; Masao Doizaki; Kazuhiko Hayashi; Masatoshi Ishigami; Akihiro Itoh; Yoshiki Hirooka; Isao Nakano; Fumihiro Urano; Kentaro Yoshioka; Hidenori Toyoda; Takashi Kumada; Hidemi Goto

Objectives: The aim of this study was to evaluate the efficacy and indication of combination therapy with ribavirin plus peginterferon‐α‐2b in chronic hepatitis C virus (HCV) patients aged 65 years and older.


World Journal of Hepatology | 2014

Transarterial chemoembolization for hepatocellular carcinoma: A review of techniques

Norihiro Imai; Masatoshi Ishigami; Yoji Ishizu; Teiji Kuzuya; Takashi Honda; Kazuhiko Hayashi; Yoshiki Hirooka; Hidemi Goto

Hepatocellular carcinoma (HCC) is one of the most common malignant diseases worldwide. While curative therapies, including resection, liver transplantation, and percutaneous ablation (percutaneous ethanol injection and radiofrequency ablation), are applicable for only a portion of the HCC population, transcatheter arterial chemoembolization (TACE) has been recognized as an effective palliative treatment option for patients with advanced HCC. TACE is also used even for single HCCs in which it is difficult to perform surgical resection or locoregional treatment due to systemic co-morbidities or anatomical problems. TACE has become widely adopted in the treatment of HCC. By using computed tomography-angiography, TACE is capable of performing diagnosis and treatment at the same time. Furthermore, TACE plays an important role in the multidisciplinary treatment for HCC when combined with other treatment. In this review, we first discuss the history of TACE, and then review the previous findings about techniques of achieving a locoregional treatment effect (liver infarction treatment, e.g., ultra-selective TACE, balloon-occluded TACE), and the use of TACE as a drug delivery system for anti-cancer agents (palliative, e.g., platinum complex agents, drug-eluting beads) for multiple lesions.


Liver Transplantation | 2014

Frequent incidence of escape mutants after successful hepatitis B vaccine response and stopping of nucleos(t)ide analogues in liver transplant recipients

Masatoshi Ishigami; Takashi Honda; Yoji Ishizu; Yasuharu Onishi; Hideya Kamei; Kazuhiko Hayashi; Yasuhiro Ogura; Yoshiki Hirooka; Hidemi Goto

The combination of nucleos(t)ide analogues (NAs) and hepatitis B immune globulin has been established as safe and effective prophylaxis against hepatitis B virus (HBV) reactivation after liver transplantation (LT). However, the essential weak point of this regimen is its high cost. The hepatitis B (HB) vaccine is an attractive alternative that costs less, and it enables some patients to have sufficiently high hepatitis B surface antibody (HBsAb) titers. Almost no data exist on whether NAs can be stopped safely in such successfully vaccinated patients. We investigated the incidence of HB vaccine escape mutants in liver recipients who had sufficient HBsAb titers after LT and stopped NAs. Among 18 HBV carriers and 7 non‐HBV patients who received grafts from hepatitis B core antibody–positive donors, 2 HBV carriers and 6 non‐HBV patients who achieved HBsAb titers >100 IU/L for >3 months after posttransplant vaccination were weaned from NAs. For the patients who showed viremia, we analyzed amino acid sequences of the HB envelope protein, and we performed a statistical analysis for the factors associated with viremia. In 4 of the 8 patients who achieved sufficient HBsAb levels after vaccination and stopped NAs, HBV DNA appeared after a median of 12 months. A sequence analysis showed various amino acid mutations, including the a‐determinant, in the HB envelope region. Frequent vaccination was shown to be a statistically significant risk factor for inducing viremia. In conclusion, although the HB vaccine is an effective substitute for prophylaxis against HBV reactivation in some patients after LT, frequent vaccination could be a risk factor for producing escape mutants. Our data demonstrate not only that caution must be exercised in stopping NAs in effectively vaccinated patients (especially in patients vaccinated frequently) but also that it is important to set stopping rules for vaccination in transplant patients. Liver Transpl 20:1211‐1220, 2014.


Seminars in Liver Disease | 2016

Histopathology of IgG4-Related Autoimmune Hepatitis and IgG4-Related Hepatopathy in IgG4-Related Disease.

Yasuni Nakanuma; Yoji Ishizu; Yoh Zen; Kenichi Harada; Takeji Umemura

Immunoglobulin G4-related disease (IgG4-RD) is a systemic disease involving many organs; it includes IgG4-related sclerosing cholangitis and inflammatory pseudotumor in the hepatobiliary system. Two types of hepatic parenchymal involvement have been reported in IgG4-RD: IgG4-related autoimmune hepatitis (AIH) and IgG4-hepatopathy. Moreover, only three cases of IgG4-related AIH have been reported. Immunoglobulin G4-related AIH is clinicopathologically similar to AIH, except for an elevated serum IgG4 level and heavy infiltration of IgG4-positive plasma cells in the liver tissue. Interestingly, IgG4-related AIH can be complicated by well-known IgG4-RD(s). Immunoglobulin G4-hepatopathy, which includes various histopathological lesions encountered in the liver of patients with type I autoimmune pancreatitis, is classified into five histological categories: portal inflammation, large bile duct damage, portal sclerosis, lobular hepatitis, and cholestasis. Immunoglobulin G4-hepatopathy is currently a collective term covering hepatic lesions primarily or secondarily related to IgG4-related sclerosing cholangitis and type 1 autoimmune pancreatitis. In conclusion, the liver is not immune to IgG4-RD, and at least two types of hepatic involvement in IgG4-RD have been reported: IgG4-related AIH and IgG4-hepatopathy. Additional studies are required to clarify their precise clinical significance with respect to IgG4-RD and inherent liver diseases.


Annals of Gastroenterology | 2016

Fibrosing cholestatic hepatitis C in post-transplant adult recipients of liver transplantation

Tomohide Hori; Yasuharu Onishi; Hideya Kamei; Nobuhiko Kurata; Masatoshi Ishigami; Yoji Ishizu; Yasuhiro Ogura

Hepatitis C recurrence continues to present a major challenge in liver transplantation (LT). Approximately 10% of hepatitis C virus (HCV)-positive recipients will develop fibrosing cholestatic hepatitis (FCH) after LT. FCH is clinically characterized as marked jaundice with cholestatic hepatic dysfunction and high titers of viremia. Pathologically, FCH manifests as marked hepatocyte swelling, cholestasis, periportal peritrabecular fibrosis and only mild inflammation. This progressive form usually involves acute liver failure, and rapidly results in graft loss. A real-time and precise diagnosis based on histopathological examination and viral measurement is indispensable for the adequate treatment of FCH. Typical pathological findings of FCH are shown. Currently, carefully selected combinations of direct-acting antivirals (DAAs) offer the potential for highly effective and safe regimens for hepatitis C, both in the pre- and post-transplant settings. Here, we review FCH caused by HCV in LT recipients, and current strategies for sustained virological responses after LT. Only a few cases of successfully treated FCH C after LT by DAAs have been reported. The diagnostic findings and therapeutic dilemma are discussed based on a literature review.


Metabolism-clinical and Experimental | 2017

Branched-chain amino acids alleviate hepatic steatosis and liver injury in choline-deficient high-fat diet induced NASH mice

Takashi Honda; Masatoshi Ishigami; Fangqiong Luo; Ma Lingyun; Yoji Ishizu; Teiji Kuzuya; Kazuhiko Hayashi; Isao Nakano; Tetsuya Ishikawa; Guo-Gang Feng; Yoshiaki Katano; Tomoya Kohama; Yasuyuki Kitaura; Yoshiharu Shimomura; Hidemi Goto; Yoshiki Hirooka

BACKGROUND For successful treatment for nonalcoholic steatohepatitis (NASH), it may be important to treat the individual causative factors. At present, however, there is no established treatment for this disease. Branched-chain amino acids (BCAAs) have been used to treat patients with decompensated cirrhosis. AIM In order to elucidate the mechanisms responsible for the effects of BCAAs on hepatic steatosis and disease progression, we investigated the effects of BCAA supplementation in mice fed a choline-deficient high-fat diet (CDHF), which induces NASH. METHODS Male mice were divided into four groups that received (1) choline-sufficient high fat (HF) diet (HF-control), (2) HF plus 2% BCAA in drinking water (HF-BCAA), (3) CDHF diet (CDHF-control), or (4) CDHF-BCAA for 8weeks. We monitored liver injury, hepatic steatosis and cholesterol, gene expression related to lipid metabolism, and hepatic fat accumulation. RESULTS Serum alanine aminotransferase (ALT) levels and hepatic triglyceride (TG) were significantly elevated in CDHF-control relative to HF-control. Liver histopathology revealed severe steatosis, inflammation, and pericellular fibrosis in CDHF-control, confirming the NASH findings. Serum ALT levels and hepatic TG and lipid droplet areas were significantly lower in CDHF-BCAA than in CDHF-control. Gene expression and protein level of fatty acid synthase (FAS), which catalyzes the final step in fatty acid biosynthesis, was significantly decreased in CDHF-BCAA than in CDHF-control (P<0.05). Moreover, hepatic total and free cholesterol of CDHF-BCAA was significantly lower than those of CDHF-control. CONCLUSIONS BCAA can alleviate hepatic steatosis and liver injury associated with NASH by suppressing FAS gene expression and protein levels.


Journal of Gastroenterology and Hepatology | 2015

Association of interleukin 28B polymorphism and mutations in the NS5A region of hepatitis C virus genotype 2 with interferon responsiveness

Kazuhiko Hayashi; Yoshiaki Katano; Yoji Ishizu; Teiji Kuzuya; Takashi Honda; Masatoshi Ishigami; Akihiro Itoh; Yoshiki Hirooka; Tetsuya Ishikawa; Isao Nakano; Kentaro Yoshioka; Hidenori Toyoda; Takashi Kumada; Hidemi Goto

The single nucleotide polymorphism (SNP) of interleukin 28B (IL28B) and the mutations in the NS5A region of hepatitis C virus (HCV) genotype 1 have been associated with response to interferon (IFN) therapy. However, these relationships in patients with HCV genotype 2 are not well understood. The aim of this study was to investigate whether the SNP of IL28B (rs8099917) and amino acid substitutions in the NS5A region in patients with HCV genotype 2 affect the response to IFN and ribavirin combination therapy.


Liver International | 2018

Liver stiffness reduction correlates with histological characteristics of Hepatitis C patients with sustained virological response

Yoshihiko Tachi; Takanori Hirai; Yuko Kojima; Yoji Ishizu; Takashi Honda; Teiji Kuzuya; Kazuhiko Hayashi; Masatoshi Ishigami; Hidemi Goto

We investigated the correlation between histological characteristics and changes in liver stiffness (LS) in patients with sustained virological response (SVR) using acoustic radiation force impulse (ARFI) elastography.


Journal of Gastroenterology and Hepatology | 2017

Daclatasvir and asunaprevir treatment in patients with severe liver fibrosis by hepatitis C virus genotype 1b infection: Real-world data

Masatoshi Ishigami; Kazuhiko Hayashi; Takashi Honda; Teiji Kuzuya; Yoji Ishizu; Tetsuya Ishikawa; Isao Nakano; Fumihiro Urano; Takashi Kumada; Kentaro Yoshioka; Hidemi Goto; Yoshiki Hirooka

In this study, we investigated the real‐world data of the first approved interferon‐free regimen in Japan: daclatasvir and asunaprevir in chronic hepatitis C patients with severe fibrosis.


Journal of Gastroenterology and Hepatology | 2017

Daclatasvir and asunaprevir treatment in patients with severe liver fibrosis by HCV genotype 1b infection: Real world data

Masatoshi Ishigami; Kazuhiko Hayashi; Takashi Honda; Teiji Kuzuya; Yoji Ishizu; Tetsuya Ishikawa; Isao Nakano; Fumihiro Urano; Takashi Kumada; Kentaro Yoshioka; Hidemi Goto; Yoshiki Hirooka

In this study, we investigated the real‐world data of the first approved interferon‐free regimen in Japan: daclatasvir and asunaprevir in chronic hepatitis C patients with severe fibrosis.

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