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Featured researches published by Ryusei Sasaki.


Japanese Journal of Cancer Research | 1999

Increased serum levels of vascular endothelial growth factor in patients with renal cell carcinoma

Kazunari Sato; Norihiko Tsuchiya; Ryusei Sasaki; Naotake Shimoda; Shigeru Satoh; Osamu Ogawa; Tetsuro Kato

Neovascularization, an essential event for the growth of solid tumors, is regulated by a number of angiogenic factors. One such factor, vascular endothelial growth factor (VEGF), is considered to exert a potent angiogenic activity, as indicated by immunohistochemical and molecular evidence. In this study we investigated the serum VEGF level (s‐VEGF) in patients with renal cell carcinoma (RCC). s‐VEGF in peripheral blood samples was analyzed in 40 RCC patients and 40 patients without cancer (controls) using a sandwich enzyme‐linked immunoassay. In 20 RCC patients, serum samples were obtained separately from the bilateral renal veins. s‐VEGF was also measured before, 4 and 8 weeks after nephrectomy in 11 patients. There were significant differences in s‐VEGF between the RCC patients and the controls (207.3 ± 32.9 vs. 71.5 ± 9.1 pg/ml, mean ± SE) (P < 0.005), between the tumor‐bearing renal veins and the contralateral ones (P < 0.01), between the pre‐ and post‐nephrectomy situations (P < 0.01) and among the various parameters of tumor status such as tumor extent (P < 0.001) and existence of metastasis (P < 0.001). s‐VEGF significantly correlated with the tumor volume obtained by a three‐dimensional measurement (r= 0.802, P < 0.0001). The sensitivity and specificity of s‐VEGF at the cut‐off level of 100 pg/ml, as determined by the receiver‐operating‐characteristics curve, were 80.0% and 72.5%, respectively. The results indicate that tumor tissue of RCC liberates VEGF into the systemic blood flow and that s‐VEGF is a possible marker for RCC.


Cancer Chemotherapy and Pharmacology | 1996

Targeted cancer chemotherapy with arterial microcapsule chemoembolization : review of 1013 patients

Tetsuro Kato; Kazunari Sato; Ryusei Sasaki; Hideaki Kakinuma; Masatsugu Moriyama

Abstract To evaluate the feasibility of intraarterial infusion of microencapsulated anticancer drugs (chemoembolization), collective data on 1013 cancer patients were reviewed. Ethylcellulose microcapsules containing mitomycin C (median total dose 20 mg), cisplatin (60 mg) or peplomycin (40 mg) were given to tumor-feeding arteries by bolus infusion in 79% of the patients and by fractionated infusion in the others, as a palliative (71%) or preoperative measure (29%). The target sites were the liver (42%), kidney (24%), intrapelvic organs (18%), lung (4%), head and neck (3%), bone (1%) and others (9%), excluding the central nervous system and gastrointestinal tract. The incidence of overall adverse effects ranged from 0.2 to 54.9%, but grade 2–3 hematological, renal and hepatic toxicities, local pain, abdominal discomfort, cutaneous reaction, remote embolization and infection were < 10%. Nine patients (0.9%) in the early stages of trials suffered serious complications including treatment-related death in two with critical underlying diseases of the target organs. The remaining patients recovered from the adverse effects, except for grade 2 cutaneous reactions, within 2 months by routine palliative measures. A ≥ 50% tumor reduction was seen in 28% of 427 evaluable tumors (42% for < 25-cm2 tumors and 20% for ≥ 25-cm2 tumors) with a median treatment number of one. The response rate depended on both the tumor size and the treatment number (P< 0.05), but it was not affected by prior therapies. Mitomycin C microcapsules produced a higher response rate. Complete or partial remission of intractable pain and genitourinary gross hemorrhage was found in two-thirds of eligible patients. The results indicate that this treatment modality, though restricted by catheter technique, can be applied to various tumor lesions with an acceptable morbidity and prospective trials are justified to evaluate the potential role of such a targeted chemotherapy.


Prostate Cancer and Prostatic Diseases | 1999

Association of vitamin D receptor gene polymorphism with protection against prostate cancer and benign prostate hyperplasia

Osamu Ogawa; Toshio Suzuki; Tomonori Habuchi; Ryusei Sasaki; Yutaka Tachiki; Toshiya Akao; Norihiko Tsuchiya; Tetsuro Kato

Association of vitamin D receptor gene polymorphism with protection against prostate cancer and benign prostate hyperplasia


Cancer Research | 2000

Association of Vitamin D Receptor Gene Polymorphism with Prostate Cancer and Benign Prostatic Hyperplasia in a Japanese Population

Tomonori Habuchi; Takehiro Suzuki; Ryusei Sasaki; Lizhong Wang; Kazunari Sato; Shigeru Satoh; Toshiya Akao; Norihiko Tsuchiya; Naotake Shimoda; Yasuhiko Wada; Akio Koizumi; Junichi Chihara; Osamu Ogawa; Tetsuro Kato


Cancer Research | 2000

Increased Risk of Prostate Cancer and Benign Prostatic Hyperplasia Associated with a CYP17 Gene Polymorphism with a Gene Dosage Effect

Tomonori Habuchi; Zhang Liqing; Takehiro Suzuki; Ryusei Sasaki; Norihiko Tsuchiya; Hiroshi Tachiki; Naotake Shimoda; Shigeru Satoh; Kazunari Sato; Yoshiyuki Kakehi; Toshiyuki Kamoto; Osamu Ogawa; Tetsuro Kato


Tohoku Journal of Experimental Medicine | 2001

Quantitative analysis of gene expressions of vascular endothelial growth factor-related factors and their receptors in renal cell carcinoma

Norihiko Tsuchiya; Kazunari Sato; Toshiya Akao; Hideaki Kakinuma; Ryusei Sasaki; Naotake Shimoda; Shigeru Satoh; Tomonori Habuchi; Osamu Ogawa; Tetsuro Kato


Tohoku Journal of Experimental Medicine | 1998

Expression of Vascular Endothelial Growth Factor Gene and Its Receptor (flt-1) Gene in Urinary Bladder Cancer

Kazunari Sato; Ryusei Sasaki; Yasunobu Ogura; Naotake Shimoda; Hisafumi Togashi; Kunihiko Terada; Toshihiro Sugiyama; Hideaki Kakinuma; Osamu Ogawa; Tetsuro Kato


Urological Research | 1999

Circulating prostate-specific antigen mRNA during radical prostatectomy in patients with localized prostate cancer: with special reference to neoadjuvant hormonal therapy.

Osamu Ogawa; Masanori Iinuma; Kazunari Sato; Ryusei Sasaki; Naotake Shimoda; Shigeru Satoh; Tetsuro Kato


The Japanese Journal of Urology | 1996

Microvessel count and vascular endothelial growth factor in renal cell carcinoma

Ryusei Sasaki


The Japanese Journal of Urology | 1995

A case of adrenal angiosarcoma

Ryusei Sasaki; Yutaka Tachiki; Taisei Tsukada; Kunio Miura; Tetsuro Kato; Ken Saito

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Takehiro Suzuki

Tokyo University of Science

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