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Dive into the research topics where Kenji Imai is active.

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Featured researches published by Kenji Imai.


Nutrition | 2015

Sarcopenia impairs prognosis of patients with liver cirrhosis.

Tatsunori Hanai; Makoto Shiraki; Kayoko Nishimura; Sachiyo Ohnishi; Kenji Imai; Atsushi Suetsugu; Koji Takai; Masahito Shimizu; Hisataka Moriwaki

OBJECTIVE Sarcopenia is characterized by the loss of skeletal muscle mass, and is reported to appear in patients with liver cirrhosis (LC). The aim of this study was to investigate the prevalence of sarcopenia in patients with LC, and to test the association between sarcopenia and patient outcomes. We also analyzed the effect of branched-chain amino acid (BCAA) supplementation on sarcopenic LC. METHODS Clinical and blood biochemical data of 130 patients with LC who underwent abdominal computed tomography scan were analyzed in this retrospective study. The cross-sectional area of skeletal muscles was measured at the level of the third lumbar vertebra on the scan. The skeletal muscle index was calculated to identify sarcopenia. Cirrhotic patients who were treated with BCAA supplementation of 12 g/d for ≥ 1 y were defined as the BCAA group, and the effect of BCAA on sarcopenic LC was evaluated. RESULTS Sixty-eight percent of all patients (82% of men and 50% of women) were diagnosed with sarcopenia. Male sex (P = 0.01) and body mass index (P < 0.0001) were predictors of sarcopenia. The multivariate Cox proportional hazards model found BCAA supplementation (hazard ratio [HR], 0.38; P = 0.01), sarcopenia (HR, 3.03; P < 0.01), and Child-Pugh classes B (HR, 2.39; P = 0.03) and C (HR, 5.49; P < 0.001) to be independently associated with mortality. The mortality of sarcopenic LC was significantly higher than that of non-sarcopenic LC (P = 0.01). Moreover, BCAA supplementation improved the survival of sarcopenic patients in subgroup analysis (P < 0.01). CONCLUSIONS Sarcopenia is significantly associated with mortality in patients with LC. BCAA supplementation might be associated with improved survival of such patients.


Hepatology Research | 2010

Insulin resistance raises the risk for recurrence of stage I hepatocellular carcinoma after curative radiofrequency ablation in hepatitis C virus‐positive patients: A prospective, case series study

Kenji Imai; Koji Takai; Yoichi Nishigaki; Shogo Shimizu; Takafumi Naiki; Hideki Hayashi; Takahiro Uematsu; Jun-ichi Sugihara; Eiichi Tomita; Masahito Shimizu; Masahito Nagaki; Hisataka Moriwaki

Aim:  Several studies have reported that insulin resistance raises the risk of primary hepatocellular carcinoma (HCC). We conducted a prospective, case series study to test the impact of insulin resistance on the recurrence after curative radiofrequency ablation (RFA) of stage I HCC in HCV‐positive patients.


Hepatology Research | 2016

Rapid skeletal muscle wasting predicts worse survival in patients with liver cirrhosis

Tatsunori Hanai; Makoto Shiraki; Sachiyo Ohnishi; Tsuneyuki Miyazaki; Takayasu Ideta; Takahiro Kochi; Kenji Imai; Atsushi Suetsugu; Koji Takai; Hisataka Moriwaki; Masahito Shimizu

Sarcopenia impairs the outcome of patients with liver cirrhosis independently of liver function reserves. The aim of this study was to investigate whether the rate of skeletal muscle wasting predicts mortality in cirrhotic patients.


Cancer Prevention Research | 2011

Possible role of visfatin in hepatoma progression and the effects of branched-chain amino acids on visfatin-induced proliferation in human hepatoma cells

Soranobu Ninomiya; Masahito Shimizu; Kenji Imai; Koji Takai; Makoto Shiraki; Takeshi Hara; Hisashi Tsurumi; Sonoko Ishizaki; Hisataka Moriwaki

Obesity and related metabolic abnormalities, including adipocytokine dysbalance, are risk factors for hepatocellular carcinoma (HCC). Visfatin, an adipocytokine that is highly expressed in visceral fat, is suggested to play a role in the progression of human malignancies. Branched-chain amino acids (BCAA) reduce the incidence of HCC in obese patients with liver cirrhosis and prevent obesity-related liver carcinogenesis in mice. In this study, we investigated the possible role of visfatin on HCC progression and the effects of BCAA on visfatin-induced proliferation of HCC cells. In patients with HCCs, serum visfatin levels were significantly correlated with stage progression and tumor enlargement. Visfatin preferentially stimulated the proliferation of HepG2, Hep3B, and HuH7 human HCC cells compared with Hc normal hepatocytes. Visfatin phosphorylated extracellular signal–regulated kinase (ERK), Akt, and GSK-3β proteins in HepG2 cells. LY294002 [a phosphoinositide-3-kinase (PI3K) inhibitor], PD98059 [a MAP/ERK 1 kinase (MEK1) inhibitor], CHIR99021 (a GSK-3β inhibitor), and BCAA significantly inhibited visfatin-induced proliferation in HepG2 cells. BCAA also inhibited phosphorylation of GSK-3β, increased cellular levels of p21CIP1, caused cell-cycle arrest in G0/G1 phase, and induced apoptosis in HCC cells in the presence of visfatin. These findings suggest that visfatin plays a critical role in the proliferation of HCC cells and may be associated with the progression of this malignancy. In addition, BCAA might inhibit obesity-related liver carcinogenesis by targeting and, possibly, by overcoming the stimulatory effects of visfatin. Cancer Prev Res; 4(12); 2092–100. ©2011 AACR.


Journal of Clinical Biochemistry and Nutrition | 2011

Increased levels of serum leptin are a risk factor for the recurrence of stage I/II hepatocellular carcinoma after curative treatment

Naoki Watanabe; Koji Takai; Kenji Imai; Masahito Shimizu; Takafumi Naiki; Masahito Nagaki; Hisataka Moriwaki

Obesity and related adipocytokine disbalance increase the risk of hepatocellular carcinoma. To determine the impact of increased levels of leptin, an obesity-related adipocytokine, on the recurrence of hepatocellular carcinoma, we conducted a prospective case-series analysis. Eighty-five consecutive primary hepatocellular carcinoma patients at our hospital from January 2006 to December 2008 were analyzed. Serum leptin level significantly correlated with Body Mass Index, total body fat, and the amount of subcutaneous fat. They included 33 with stage I/II, who underwent curative treatment. The factors contributing to recurrence of hepatocellular carcinoma, including leptin, were subjected to univariate and multivariate analyses using the Cox proportional hazards model. Body Mass Index (p = 0.0062), total body fat (p = 0.0404), albumin (p = 0.0210), α-fetoprotein (p = 0.0365), and leptin (p = 0.0003) were significantly associated with the recurrence of hepatocellular carcinoma in univariate analysis. Multivariate analysis suggested that leptin (hazard ratio 1.25, 95% CI 1.07–1.49, p = 0.0035) was a sole independent predictor. Kaplan-Meier analysis showed that recurrence-free survival was lower in patients with greater serum leptin concentrations (>5 ng/mL, p = 0.0221). These results suggest that the serum leptin level is a useful biomarker for predicting the early recurrence of hepatocellular carcinoma.


Hepatology Research | 2015

Impact of serum glycosylated Wisteria floribunda agglutinin positive Mac-2 binding protein levels on liver functional reserves and mortality in patients with liver cirrhosis.

Tatsunori Hanai; Makoto Shiraki; Sachiyo Ohnishi; Tsuneyuki Miyazaki; Takayasu Ideta; Takahiro Kochi; Kenji Imai; Atsushi Suetsugu; Koji Takai; Masahito Shimizu; Hisataka Moriwaki

Serum glycosylated Wisteria floribunda agglutinin positive Mac‐2 binding protein (WFA+‐M2BP) levels are a non‐invasive and reliable marker to assess the degree of liver fibrosis. We investigated the use of WFA+‐M2BP levels to predict mortality in patients with liver cirrhosis (LC).


Hepatology Research | 2014

Free fatty acid as a marker of energy malnutrition in liver cirrhosis

Tatsunori Hanai; Makoto Shiraki; Kayoko Nishimura; Kenji Imai; Atsushi Suetsugu; Koji Takai; Masahito Shimizu; Takafumi Naiki; Hisataka Moriwaki

Protein–energy malnutrition is frequently observed in patients with liver cirrhosis (LC). Non‐protein respiratory quotient (npRQ) measured by indirect calorimetry is a good marker to estimate energy malnutrition, and predicts the prognosis of patients with LC. However, measurement of npRQ is limited because of the high cost of indirect calorimetry. Our aim was to find out an alternative marker to npRQ that can be used in the routine clinical setting.


International Journal of Molecular Sciences | 2014

Impact of Serum Chemerin Levels on Liver Functional Reserves and Platelet Counts in Patients with Hepatocellular Carcinoma

Kenji Imai; Koji Takai; Tatsunori Hanai; Makoto Shiraki; Yusuke Suzuki; Hideki Hayashi; Takafumi Naiki; Youichi Nishigaki; Eiichi Tomita; Masahito Shimizu; Hisataka Moriwaki

Obesity-related metabolic abnormalities, including adipokine imbalance and chronic inflammation, are involved in liver carcinogenesis. Chemerin, a novel adipokine, plays a critical role in adipogenesis, energy metabolism, and inflammation. We evaluated the impact of serum chemerin levels on liver functional reserves in hepatocellular carcinoma (HCC) patients and on the recurrence and prognosis of HCC. This study included 44 patients with any stage of HCC who underwent curative treatment at Gifu Municipal Hospital (Gifu, Japan) between 2006 and 2007. Recurrence-free survival and overall survival were estimated using the Kaplan-Meier method. Serum albumin levels (Pearson’s correlation coefficient; r = 0.3110, p = 0.0399), platelet counts (r = 0.4159, p = 0.0050), and prothrombin times (r = 0.3775, p = 0.0115) were significantly correlated with serum chemerin levels in patients with HCC, and they were inversely correlated with Child-Pugh scores (r = −0.3732, p = 0.0126), serum alanine aminotransferase levels (r = −0.3864, p = 0.0105), and total bilirubin levels (r = −0.4023, p = 0.0068). Among these variables, a multiple comparison test identified that platelet counts and total bilirubin levels were associated with serum chemerin levels (p < 0.0083). No significant correlation was found between serum chemerin levels and recurrence-free survival (p = 0.3691) or overall survival (p = 0.7916). In HCC patients, serum chemerin concentrations were correlated with liver functional reserves and platelet counts, but not with recurrence or prognosis.


Journal of Carcinogenesis | 2012

Acyclic retinoid in chemoprevention of hepatocellular carcinoma: Targeting phosphorylated retinoid X receptor-α for prevention of liver carcinogenesis

Masahito Shimizu; Yohei Shirakami; Kenji Imai; Koji Takai; Hisataka Moriwaki

One of the key features of hepatocellular carcinoma (HCC) is the high rate of intrahepatic recurrence that correlates with poor prognosis. Therefore, in order to improve the clinical outcome for patients with HCC, development of a chemopreventive agent that can decrease or delay the incidence of recurrence is a critical issue for urgent investigation. Acyclic retinoid (ACR), a synthetic retinoid, successfully improves HCC patient survival by preventing recurrence and the formation of secondary tumors. A malfunction of the retinoid X receptor-α (RXRα) due to phosphorylation by the Ras-MAPK signaling pathway plays a critical role in liver carcinogenesis, and ACR exerts chemopreventive effects on HCC development by inhibiting RXRα phosphorylation. Here, we review the relationship between retinoid signaling abnormalities and liver disease, the mechanisms of how RXRα phosphorylation contributes to liver carcinogenesis, and the detailed effects of ACR on preventing HCC development, especially based on the results of our basic and clinical research. We also outline the concept of “clonal deletion and inhibition” therapy, which is defined as the removal and inhibition of latent malignant clones from the liver before they expand into clinically detectable HCC, because ACR prevents the development of HCC by implementing this concept. Looking toward the future, we discuss “combination chemoprevention” using ACR as a key drug since it can generate a synergistic effect, and may thus be an effective new strategy for the prevention of HCC.


Hepatology Research | 2017

Sarcopenia predicts minimal hepatic encephalopathy in patients with liver cirrhosis

Tatsunori Hanai; Makoto Shiraki; Satoshi Watanabe; Takahiro Kochi; Kenji Imai; Atsushi Suetsugu; Koji Takai; Hisataka Moriwaki; Masahito Shimizu

Minimal hepatic encephalopathy (MHE) and sarcopenia impair the health‐related quality of life and prognosis of patients with liver cirrhosis; however, the relationship between MHE and sarcopenia remains unclear. The aim of this study was to investigate their relationship and to identify the predictors of MHE in cirrhotic patients.

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