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Featured researches published by Kanta Oikawa.


Gut | 2004

Prevention of critical telomere shortening by oestradiol in human normal hepatic cultured cells and carbon tetrachloride induced rat liver fibrosis.

Ryo Sato; Chihaya Maesawa; Kentaro Fujisawa; Kei Wada; Kanta Oikawa; Yasuhiro Takikawa; Kazuyuki Suzuki; Hiroki Oikawa; K Ishikawa; Tomoyuki Masuda

Background and aim: Significant telomere shortening of hepatocytes is associated with replicative senescence and a non-dividing state in chronic liver disease, resulting in end stage liver failure and/or development of hepatocellular carcinoma. To prevent critical telomere shortening in hepatocytes, we have focused on oestrogen dependent transactivation of the human telomerase reverse transcriptase (hTERT) gene as a form of telomerase therapy in chronic liver disease. Methods: We examined expression of hTERT mRNA and its protein, and telomerase activity (TA) in three human normal hepatic cell lines (Hc-cells, h-Nheps, and WRL-68) before and after treatment with 17β-oestradiol. The effects of exogenous oestradiol administration were examined in a carbon tetrachloride (CCl4) induced model of liver fibrosis in rats. Results: Expression of hTERT mRNA and its protein was upregulated by oestradiol treatment. Telomere length decreased in Hc-cells and h-Nheps with accumulated passages whereas with long term oestradiol exposure it was greater than without oestradiol. The incidence of β-galactosidase positive cells, indicating a state of senescence, decreased significantly in oestradiol treated cells in comparison with non-treated cells (p<0.05). TA in both male and female rats with CCl4 induced liver fibrosis was significantly higher with oestradiol administration than without (p<0.05). Long term oestradiol administration markedly rescued the hepatic telomere from extensive shortening in both male and female rats. Conclusion: These results suggest that oestradiol acts as a positive modulator of the hTERT gene in the liver. Oestrogen dependent transactivation of the hTERT gene is a new strategy for slowing the progression of chronic liver disease.


Journal of Gastroenterology and Hepatology | 2010

Effects of branched-chain amino acid-enriched nutrient for patients with hepatocellular carcinoma following radiofrequency ablation: a one-year prospective trial.

Hidekatsu Kuroda; Akira Ushio; Yasuhiro Miyamoto; Kei Sawara; Kanta Oikawa; Kazuhiro Kasai; Ryujin Endo; Yasuhiro Takikawa; Akinobu Kato; Kazuyuki Suzuki

Background and Aim:  This prospective control study examined whether supplementation with branched‐chain amino acid (BCAA)‐enriched nutrients can help maintain and improve residual liver function and nutritional status in cirrhotic patients with hepatocellular carcinoma (HCC) after radiofrequency ablation (RFA).


Cancer | 2012

Therapeutic efficacy of combination therapy with intra-arterial 5-fluorouracil and systemic pegylated interferon α-2b for advanced hepatocellular carcinoma with portal venous invasion.

Kazuhiro Kasai; Akira Ushio; Yukiho Kasai; Kei Sawara; Yasuhiro Miyamoto; Kanta Oikawa; Hidekatsu Kuroda; Yasuhiro Takikawa; Kazuyuki Suzuki

The prognosis of advanced hepatocellular carcinoma (HCC) remains poor, particularly among patients with portal vein tumor thrombosis (PVTT). This study evaluated the efficacy of combined 5‐fluorouracil and pegylated interferon (PEG‐IFN) α‐2b in patients with advanced HCC.


Hepatology Research | 2010

Changes in liver function parameters after percutaneous radiofrequency ablation therapy in patients with hepatocellular carcinoma

Hidekatsu Kuroda; Kazuhiro Kasai; Keisuke Kakisaka; Yuki Yasumi; Koujiro Kataoka; Akira Ushio; Yasuhiro Miyamoto; Kei Sawara; Kanta Oikawa; Koryo Kondo; Yoshiaki Miura; Ryujin Endo; Yasuhiro Takikawa; Kazuyuki Suzuki

Aim:  To evaluate changes in liver function parameters and risk factors 1 year after percutaneous radiofrequency ablation (RFA) therapy in patients with hepatocellular carcinoma (HCC).


Journal of Clinical Ultrasound | 2012

Serial changes of liver stiffness measured by acoustic radiation force impulse imaging in acute liver failure: A case report

Hidekatsu Kuroda; Yasuhiro Takikawa; Mio Onodera; Keisuke Kakisaka; Yuichi Yoshida; Koujiro Kataoka; Kei Sawara; Yasuhiro Miyamoto; Kanta Oikawa; Ryujin Endo; Kazuyuki Suzuki

Acoustic radiation force impulse (ARFI) imaging is a new technology used to determine liver elasticity. We report the case of a patient that survived hyperacute‐type acute liver failure (ALF) and who showed a dramatic change in the value of shear wave velocity (SWV) measured by ARFI, which corresponded with the severity of her liver damage. The value of SWV increased significantly up to 3.6 ± 0.3 m/s during the encephalopathy phase and then decreased along with the recovery of liver function, the blood flow of the right portal vein, and the liver volume. These findings suggest the value of SWV in ALF as a reliable marker of liver tissue damage. Further investigations of the pathophysiological significance of SWV in ALF are warranted.


Life Sciences | 2014

A disintegrin and metalloproteinase 17 (ADAM17) mediates epidermal growth factor receptor transactivation by angiotensin II on hepatic stellate cells

Hiroki Oikawa; Chihaya Maesawa; Yoshinori Tatemichi; Yutaka Nishinari; Masao Nishiya; Hisata Mizugai; Aya Ikeda; Kanta Oikawa; Yasuhiro Takikawa; Tomoyuki Masuda

AIMS Epidermal growth factor receptor (EGFR) transactivation induced by angiotensin II (Ang II) participates in the progression of various diseases. A disintegrin and metalloproteinase 17 (ADAM17) is thought to promote renal fibrosis, cardiac hypertrophy with fibrosis and atherosclerosis by activation of the EGFR through secretion of EGFR ligands. The purpose of this study was to investigate whether Ang II-induced EGFR transactivation occurs on hepatic stellate cells (HSCs) and whether the reaction is mediated via ADAM17. MAIN METHODS Ang II-induced EGFR transactivation and cellular proliferation of the human HSC line LI90 were investigated using Western blotting and ATP assay, respectively. Ang II-induced secretion of mature amphiregulin into the cell culture medium was evaluated by enzyme-linked immunosorbent assay (ELISA). KEY FINDINGS An inhibitor of ADAM17, TAPI-1, as well as antagonists of EGFR and angiotensin II type-1 receptor (AT1), attenuated Ang II-induced EGFR transactivation and proliferation of LI90 cells. Furthermore, silencing of ADAM17 inhibited Ang II-induced secretion of mature amphiregulin in addition to EGFR transactivation. SIGNIFICANCE These results indicate that ADAM17 mediates Ang II-induced EGFR transactivation on HSCs, and that this process may participate in the progression of liver fibrosis.


Medical Science Monitor | 2011

Conservative treatment of an aortoesophagial fistula after endovascular stent grafting for a thoracic aortic aneurysm

Kazuhiro Kasai; Akira Ushio; Yoko Tamura; Kei Sawara; Yukiho Kasai; Kanta Oikawa; Masaki Endo; Yasuhiro Takikawa; Kazuyuki Suzuki

Summary Background Aortoesophageal fistula (AEF) is an uncommon condition that presents a problem in therapy because of the high rate of morbidity and mortality associated with its surgical management and the uniformly fatal outcome of medical treatment. In this article we describe a case of secondary AEF after endoluminal stent grafting of the thoracic aorta, which was observed by only conservative management and followed up for 14 months with no signs of recurrent hemorrhage or chronic mediastinitis. Case Report A 54-year old man with hepatocellular carcinoma (HCC) was admitted to our hospital because of tarry stool. He had a history of traumatic aneurysm, and undergone segmental replacement with a stent graft three years ago. After admission, Esophagogastroduodenoscopy and computed tomography identified AEF. He was treated conservatively, because his stage of HCC was advanced. Oral intake was prohibited, and the patient received proton pump inhibitors, intravenous hyperalimentation and antibiotics. Afterwards, no signs of hemorrhage were observed. Although oral intake was resumed after that, another bleeding event or development of mediastinitis was not observed. Subsequently, He was received chemotherapy for advanced HCC, and we observed downstaging of his advanced HCC. Conclusions Although we observed 14 months survival in our case under conservative management of secondary AEF, it seems that the treatment of secondary AEF should do the operative management.


World Journal of Gastroenterology | 2013

Therapeutic efficacy of transarterial chemo-embolization with a fine-powder formulation of cisplatin for hepatocellular carcinoma

Kazuhiro Kasai; Akira Ushio; Yukiho Kasai; Kei Sawara; Yasuhiro Miyamoto; Kanta Oikawa; Yasuhiro Takikawa; Kazuyuki Suzuki

AIM To evaluate the efficacy of transarterial chemoembolization (TACE) using a suspension of a fine-powder formulation of cisplatin (DDPH) in lipiodol (LPD) in the treatment of hepatocellular carcinoma (HCC). METHODS The subjects were 262 HCC patients treated with TACE using a DDPH-LPD suspension. The DDPH-LPD suspension was prepared by mixing 50 mg of DDPH into 10 mL of LPD. TACE was repeated when treated lesions relapsed and/or new hepatic lesions were detected. These patients received additional TACE using the same agent. TACE was repeated until complete regression of the tumor was obtained. The primary efficacy endpoint of the current study was the objective early response rate. Secondary efficacy endpoints were progression-free survival (PFS) and overall survival. RESULTS The objective early response rate was 43.6%. Cumulative PFS rates were 56.7% at 6 mo, 23.1% at 12 mo, 13.4% at 18 mo, and 10.5% at 24 mo. The median PFS was 6.6 mo. Cumulative survival rates were 90.6% at 6 mo, 81.9% at 12 mo, 70.5% at 24 mo, and 58.8% at 36 mo. Median survival time was 46.6 mo. All adverse reactions were controllable by temporary suspension of treatment. No serious complications or treatment-related deaths were observed. CONCLUSION TACE using a suspension of DDPH in LPD may be a useful treatment for HCC.


Hepatology Research | 2015

Bimodal peaks of liver stiffness in a case of drug‐induced liver injury

Keisuke Kakisaka; Yohei Kooka; Takayoshi Oikawa; Akiko Suzuki; Kanta Oikawa; Hidekatsu Kuroda; Kazuhiro Kasai; Yasuhiro Takikawa

A 69‐year‐old male complained of general fatigue and presented with elevation of liver enzymes without any cause of liver injury. We diagnosed him with hepatocellular drug‐induced liver injury (DILI). Liver stiffness, which was evaluated according to the shear wave velocity (SWV) using virtual touch tissue quantification, was serially observed during hospitalization. A fast SWV was noted on the date of admission, indicating a “hard” degree of liver stiffness. The SWV gradually decreased until the 20th hospital day. However, the patients liver enzymes again became elevated on the 20th hospital day, and the SWV simultaneously increased in association with a rise in the total bilirubin level. The laboratory data for the second peak of the SWV indicated mixed‐type DILI; therefore, the patients pathological state transitioned from the hepatocellular type to the mixed type. A liver biopsy performed before discharge revealed a state of recovery from acute inflammation without fibrotic changes. We conclude that the second peak of the SWV may be affected by the presence of intrahepatic cholestasis. We herein report the occurrence of bimodal peaks of liver stiffness in a patient with DILI. In such cases, each peak of liver stiffness may be the result of a different pathological mechanism, namely acute inflammation versus acute intrahepatic cholestasis. Although the detailed mechanisms underlying the development of liver stiffness due to intrahepatic cholestasis remain unclear, this case presented a limitation of virtual touch tissue quantification for evaluation of liver stiffness as fibrosis marker in the liver with intrahepatic cholestasis.


Journal of Nutritional Science and Vitaminology | 2016

Comparison of Predicted Energy Expenditure in Japanese Patients with Non-Alcoholic Fatty Liver Disease to Establish a Suitable Nutrition Intervention.

Kei Endo; Keisuke Kakisaka; Kanta Oikawa; Ryujin Endo; Yasuhiro Takikawa

The incidence of non-alcoholic fatty liver disease (NAFLD) is increasing in Western and Asian countries, including Japan. NAFLD includes the condition of non-alcoholic steatohepatitis, which can progress to end-stage liver disease. Weight reduction based on basal energy expenditure (BEE) is considered to be the only established treatment for patients with NAFLD. However, a formula that is suitable for predicting BEE in Japanese patients with NAFLD remains to be determined. We enrolled 77 Japanese patients who were diagnosed with NAFLD according to histological findings. Their BEE was measured (mBEE) by indirect calorimetry. Physical findings, laboratory data and their predicted BEE (pBEE) values were compared with the mBEE values. All pBEE values were evaluated as a root mean squared error (RMSE) and an accurate estimation. The mBEE values correlated with the patients weight, skeletal muscle mass, and age. Most of predictive formulae overestimated BEE in NAFLD patients in the present study. In contrast, the Kyoto equation provided an accurate prediction. Most prediction formulae included body weight as a reference of the skeletal muscle mass and were established using data from a healthy study population. However, differences in muscle mass exist among different races, and body composition differs between healthy individuals and those with high BMIs. The improved accuracy of the Kyoto equation is likely due to the similar backgrounds of the patients in the present study. The Kyoto equation is the most suitable formula for estimating BEE in Japanese patients with NAFLD.

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Kei Sawara

Iwate Medical University

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Kazuhiro Kasai

Iwate Medical University

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Akira Ushio

Iwate Medical University

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Ryujin Endo

Iwate Medical University

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