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Dive into the research topics where Yasuhiko Masui is active.

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Featured researches published by Yasuhiko Masui.


Cancer Chemotherapy and Pharmacology | 1994

Single instillation of hydroxypropylcellulose-doxorubicin as treatment for superficial bladder carcinoma

Kousuke Ueda; Hiroshi Sakagami; Yasuhiko Masui; Takehiko Okamura

A single instillation of hydroxypropylcellulose (HPC)-doxorubicin (20 mg/20 ml) was performed in 20 patients with superficial bladder carcinoma. The therapeutic effect was assessed by cystoscopy at 14–30 days after the instillation, and the residual tumor tissue was resected by transurethral resection (TUR) when possible. The results obtained for the therapeutic effect were as follows: a complete response (CR), in 7 cases (35%); a reduction in size of more than 50% (partial response, PR), in 6 cases (30%); and a reduction of less than 25% in size (no change, NC), in 7 cases (35%). Combined intravesical instillation of HPC-doxorubicin and local hyperthermia using a Thermotron RF-8 was performed in 11 patients with recurrent superficial bladder carcinoma. The total number of treatment courses ranged from three to five per patient. The results obtained for the effect of this combined treatment were as follows: a CR, in 6 cases (54.5%); a PR, in 3 cases (27.3%); and NC, in 2 cases (18.2%). Therefore, the combination of intravesical instillation of HPC-doxorubicin and local hyperthermia was more effective against superficial bladder carcinoma than the single instillation of the chemotherapeutic agent alone.


European Urology | 1992

Studies on the retention of the mucous-membrane-adhesive anticancer agent hydroxypropylcellulose doxorubicin

Kousuke Ueda; Hiroshi Sakagami; Kazuo Ohtaguro; Yasuhiko Masui

Incorporation of hydroxypropylcellulose (HPC-)doxorubicin, which we developed as a mucous-membrane-adhesive drug preparation, was instilled into the urinary bladder in 10 clinical cases. Tumor of the urinary bladder was a single tumor in all 10 cases, and preclinical histology showed transitional cell carcinoma, grade 1 or 2, and a lower stage than T1. HPC-doxorubicin, 20 mg/20 ml, was administered in 5 cases, and the other 5 cases received the conventional aqueous doxorubicin, 20 mg/20 ml by way of a catheter and the urethra. Cold punch biopsy was performed after 3 days of instillation, and the incorporation of doxorubicin into both tumorous and normal tissue was measured by high-pressure liquid chromatography. After 3 days, it was found that in the HPC-doxorubicin-administered group, doxorubicin was detected in both tumorous and normal tissue, but it was not detected in either tissue after aqueous doxorubicin administration. In 5 cases of the HPC-doxorubicin group, doxorubicin levels in the tumorous and normal tissue were examined, and it was found that significantly more doxorubicin was detected in the tumorous tissues. Thus, it may be said that our HPC-doxorubicin remained longer within the urinary bladder than the conventional aqueous doxorubicin preparation. Instilled HPC-doxorubicin is more highly concentrated in the tumorous tissue than in the normal bladder tissue, and thus, HPC-compounded anticancer drugs may be therapeutically more useful.


European Urology | 1993

One-shot intravesical instillation of the mucous adhesive anticancer agent hydroxypropylcellulose-doxorubicin for the treatment of superficial bladder carcinoma is sufficient to determine antitumor effects

Kousuke Ueda; Hiroshi Sakagami; Yasuhiko Masui; Takehiko Okamura; Kazuo Ohtaguro

A 20 mg/20 ml dose of the membrane adhesive anticancer preparation, hydroxypropylcellulose-doxorubicin (HPC-doxorubicin), was instilled into urinary bladders through a catheter for the treatment of superficial bladder carcinomas (Ta-T1). After 14-30 days, the effects of the drug on tumors was examined by cystoscopy, and the residual tumor tissue where reduction in size was observed was resected by transurethral resection (TUR). Therapeutic effects were as follows: a complete response (CR) was found in 6 cases (37.5%), a reduction in size of more than 50% (partial response = PR) in 4 cases (25%), and a less than 25% reduction (no change = NC) in 6 cases (37.5%). In no case was progression of the disease noted. In CR cases, cold cup punch biopsy revealed no tumor cells remaining at the site where the tumor was present before the instillation. Side effects such as bladder irritation were found in 4 cases, but they were only temporary in nature. The one-dose HPC-doxorubicin approach developed by ourselves allowed detection of antitumor effects between 14 and 30 days after the instillation and therefore determination of sensitivities at an earlier stage than with instillation of the conventional water-soluble type of doxorubicin hydrochloride.


Japanese Journal of Hyperthermic Oncology | 1995

The Effectiveness of The Gripping Method as an Adjunct to Local Hyperthermia Thermotron RF-8 Treatment of Deep Seated Tumors

Kousuke Ueda; Takehiko Okamura; Keiji Fujita; Hidetoshi Akita; K. Kohri; Takaichirou Itoe; Yasuhiko Masui; Eiichi Kano


The Japanese Journal of Urology | 1988

Studies of anticancer drugs adhering to bladder mucosa for the treatment of bladder cancer

Kousuke Ueda; Yasuhiko Masui; Takehiko Okamura; Kazuo Ohtaguro; Kazuhiko Inoue


Japanese Journal of Hyperthermic Oncology | 1992

Therapeutic Effects of Local Hyperthermia for Hormone-Resistant Prostatic Cancer

Kosuke Ueda; Yasuhiko Masui


Japanese Journal of Hyperthermic Oncology | 1991

Clinical Results of Local Hyperthermia with Thermotron RF-8 for the Treatment of Prostatic Carcinoma and Prostatic Hyperplasia

Kosuke Ueda; Yasuhiko Masui


Japanese Journal of Hyperthermic Oncology | 1995

STUDY OF BLOOD CIRCULATION DURING LOCAL HYPERTHERMIA IN PATIENTS WITH PROSTATIC CARCINOMA

Kousuke Ueda; Yutarou Hayashi; Takehiko Okamura; K. Kohri; Takaichirou Itou; Yasuhiko Masui; Seiji Hattori


Japanese Journal of Hyperthermic Oncology | 1995

LONG-TERM CLINICAL RESULTS OF LOCAL HYPERTHERMIA FOR INVASIVE BLADDER CARCINOMAS

Kousuke Ueda; Takehiko Okamura; Yasuhiko Masui


The Japanese Journal of Urology | 1993

A study of testicular tumor on magnetic resonance imaging

Yutaro Hayashi; Masayuki Tsugaya; Noriaki Hirao; Yasuhiko Masui; Kazuo Ohtaguro

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Takehiko Okamura

University of Nebraska Medical Center

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Kosuke Ueda

Nagoya City University

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K. Kohri

Nagoya City University

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