Kenichi Kuwahara
Hiroshima University
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Featured researches published by Kenichi Kuwahara.
Pancreas | 2003
Kenichi Kuwahara; Tamito Sasaki; Yukio Kuwada; Masateru Murakami; Souichirou Yamasaki; Kazuaki Chayama
Introduction It has been reported that angiogenic factors play an important role in proliferation and metastasis in various cancers. Aim To investigate the expression of angiogenic factors and microvessel density (MVD) in pancreatic ductal carcinoma and to examine the correlations among expression of angiogenic factors, clinicopathologic parameters, and clinical prognosis. Methodology Paraffin-embedded specimens from 55 patients with pancreatic ductal carcinoma were immunostained for vascular endothelial growth factor (VEGF), fibroblast growth factor-2 (FGF-2), platelet-derived endothelial cell growth factor (PD-ECGF), and CD34. The correlations among the expression of individual angiogenic factors and MVD, the clinicopathologic features, and the clinical prognoses were analyzed statistically. Results Immunostaining demonstrated that 70.8% of pancreatic ductal carcinomas were positive for VEGF, 60.9% for FGF-2, and 57.2% for PD-ECGF. A significant correlation was observed between VEGF expression and MVD (p < 0.05) but not between FGF-2 or PD-ECGF and MVD. Although the expression of each angiogenic factor had no correlation with clinicopathologic features, the patients with tumors that showed high expression of VEGF and FGF-2 had significantly shorter survival times than those with low or no such expression (p < 0.05). Conclusions These observations suggest that the expression of VEGF closely correlates with MVD and with a poor prognosis in pancreatic ductal carcinoma.
Journal of Clinical Gastroenterology | 2006
Masahiro Serikawa; Tamito Sasaki; Yoshifumi Fujimoto; Kenichi Kuwahara; Kazuaki Chayama
Goals The aim of this study was to examine and clarify the preoperative markers that are useful for differentiating between benign and malignant lesions of intraductal papillary-mucinous neoplasms (IPMN) of the pancreas, grouped according to morphologic classification. Background There are various stages of pathology in IPMN, ranging from benign to malignant lesions. Although the determination of appropriate treatment guidelines to deal with IPMN is a critical issue, no such guidelines have been established. Patients and Methods One hundred twenty cases of IPMN were classified morphologically into either main or branch duct types. We compared the morphologic classification with histopathologic diagnosis using indicators of malignancy detected by imaging such as main duct diameter, the number and diameter of cysts, and the presence or absence of mural nodules. We also examined the usefulness of pancreatic juice cytology and measurement of telomerase activity as indicators of malignancy. Finally, we performed a survival analysis on the basis of morphologic classification to determine prognosis of IPMN. Results Whereas a high incidence (64%) of malignant lesions was seen in main duct type IPMN, benign lesions were dominant (80.5%) in branch duct type IPMN. Survival analysis showed that the prognosis was significantly worse in main duct type than in branch duct type IPMN. The lesions were aggravated in all patients with main duct type who did not undergo resection, resulting in death due to progression of the pancreatic lesion. The incidence of mural nodules was a useful indicator in main duct type, whereas main duct diameter and incidence of mural nodules were useful indicators in branch duct type. Although pancreatic juice cytology showed a high accuracy rate with low sensitivity for determining malignancy, measurement of telomerase activity in this juice was very effective for differentiating between benign and malignant lesions. Conclusions The incidence of malignant lesions was extremely high in main duct type IPMN, indicating that surgery is required in all these patients. However, to determine whether surgery is indicated in branch duct type IPMN it is necessary to obtain an appropriate image diagnosis focusing on main duct diameter and mural nodules and also to carry out cytology and measurement of telomerase activity in samples of pancreatic juice.
Biochemical and Biophysical Research Communications | 2004
Masateru Murakami; Tamito Sasaki; Souichirou Yamasaki; Kenichi Kuwahara; Hideki Miyata; Kazuaki Chayama
Oncology Reports | 2004
Masateru Murakami; Tamito Sasaki; Hideki Miyata; Souichirou Yamasaki; Kenichi Kuwahara; Kazuaki Chayama
International Journal of Oncology | 2006
Hideki Miyata; Tamito Sasaki; Kenichi Kuwahara; Masahiro Serikawa; Kazuaki Chayama
Oncology Reports | 2004
Kenichi Kuwahara; Tamito Sasaki; Kensou Kobayashi; Bunjirou Noma; Masahiro Serikawa; Tomohiro Iiboshi; Hideki Miyata; Yukio Kuwada; Masateru Murakami; Souichirou Yamasaki; Kenji Kariya; Kenji Morinaka; Kazuaki Chayama
Oncology Reports | 2003
Masateru Murakami; Tamito Sasaki; Yukio Kuwada; Souichirou Yamasaki; Kenichi Kuwahara; Kazuaki Chayama
Gastrointestinal Endoscopy | 2008
Kenso Kobayashi; Tamito Sasaki; Yoshifumi Fujimoto; Kenichi Kuwahara; Masahiro Serikawa; Bunjiro Noma; Hiroshi Itsuki; Kazuaki Chayama
Gastroenterology | 2008
Bunjiro Noma; Tamito Sasaki; Yoshifumi Fujimoto; Kenichi Kuwahara; Masahiro Serikawa; Kenso Kobayashi; Hiroshi Ituki; Kazuaki Chayama
Gastroenterology | 2003
Kenichi Kuwahara; Tamito Sasaki; Kenji Morinaka; Kenji Kariya; Yukio Kuwada; Souichirou Yamasaki; Masateru Murakami; Hideki Miyata; Tomohiro Iiboshi; Masahiro Serikawa; Kazuaki Chayama