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Dive into the research topics where Takashi Yamashita is active.

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Featured researches published by Takashi Yamashita.


International Journal of Radiation Oncology Biology Physics | 2000

A preliminary outcome analysis of the patterns of care study in Japan for esophageal cancer patients with special reference to age: Non surgery group

Kazuaki Tanisada; Teruki Teshima; Hiroshi Ikeda; Mitsuyuki Abe; Jean B. Owen; Gerald E. Hanks; Takashi Yamashita; Masamichi Nishio; Shogo Yamada; Kunio Sakai; Masahiro Hiraoka; Yutaka Hirokawa; Masahiko Oguchi; Toshihiko Inoue

BACKGROUNDnThe Patterns of Care Study (PCS) was imported to Japan from the United States in July 1996. A preliminary outcome analysis of the PCS for esophageal cancer patients in Japan was made with special reference to age, because the elderly population is rapidly increasing in Japan.nnnPATIENTS AND METHODSnFrom July 1996 to February 1998, external PCS audits were performed for 37 institutions nationwide and detailed information of 561 esophageal cancer patients treated during the period 1992-1994 was collected by using the fifth PCS data format developed in the United States. This format was provided courtesy of the American College of Radiology. For this study, patients who had not undergone surgery (n = 336) were selected. The patients were classified into three age groups: < 65 years old (n = 119), between 65 and 74 years (n = 93), and 75 years or older (n =123). Coxs proportional hazards model was used for the statistical analysis, with survival, acute/subacute complication and late complication of grade 3 or more based on RTOG criteria, as the endpoints.nnnRESULTSnSignificant prognostic factors for the entire non-surgery group were Karnofsky Performance Status (KPS) (p = 0.0007), stage (p = 0.0001), and external irradiation dose (p = 0.0001). For the younger group, KPS (p = 0.0004), stage (p = 0.0197), and utilization of brachytherapy (p = 0.0010) were significant, while for the intermediate age group it was KPS (p = 0. 0027), history of pulmonary disease (p = 0.0339), stage (p = 0.0001), and external dose (p = 0.0001), and for the elderly group, stage (p = 0.0001) and external irradiation dose (p = 0.0224) were significant. Significant risk factors for complications for the entire group were stage (p = 0.0411), external dose (p = 0.0163), and stratification of institution (academic vs. nonacademic) (p = 0. 0114). Significant risk factors for the younger group were history of pulmonary disease (p = 0.0495) and external dose (p = 0.0037), and the other age groups showed no significant risk factors.nnnCONCLUSIONnAge was not a significant prognostic or risk factor for esophageal cancer patients in the non-surgery group treated with radiation therapy. Therefore, radiation therapy represented an important treatment modality for the elderly as well as for the younger esophageal cancer patients. External dose was a treatment-related prognostic factor for the elderly as well as for the intermediate age group.


International Journal of Gynecological Cancer | 2009

Phase I study of concurrent chemoradiotherapy with weekly cisplatin and paclitaxel chemotherapy for locally advanced cervical carcinoma in Japanese women.

Kenji Umayahara; Nobuhiro Takeshima; Takayuki Nose; Kiyoshi Fujiwara; Yuko Sugiyama; Kuniko Utsugi; Takashi Yamashita; Ken Takizawa

The purpose of this study was to evaluate the use of concurrent chemoradiotherapy involving weekly administration of cisplatin and paclitaxel for the treatment of locally advanced cervical carcinoma in Japanese women. Twenty Japanese patients were registered for this phase I study. Radiation therapy was performed using external irradiation and high-dose rate intracavitary irradiation of the pelvis. Chemotherapy was performed once a week until termination of the radiation therapy. The dose of cisplatin was decided as 30 mg/m2, and the initial dose of paclitaxel was set as 30 mg/m2, with a planned incremental increase of 10 mg/m2 up to 70 mg/m2. When 3 to 6 patients were registered at each dose level and dose-limiting toxicity (DLT) was noted in more than 3 patients, the dose level was assumed to be the maximum tolerated dose. Among the 20 patients, 1 patient experienced DLT during 2 courses because of dehydration and arrhythmia. In another patient, chemotherapy was discontinued after 4 courses because of a hypersensitivity reaction to paclitaxel at dose level 3. No patient experienced DLT resulting from hematologic toxicities. All patients underwent radiation therapy according to schedule without any discontinuations. A complete response was obtained in 16 patients. Based on the results obtained from this study, weekly administration of 30 mg/m2 cisplatin and 50 mg/m2 paclitaxel with concurrent chemoradiotherapy can be considered a tolerable and safe dose for the treatment of locally advanced cervical carcinoma in Japanese women.


Annals of Nuclear Medicine | 2004

Improved detection of axillary hot nodes in lymphoscintigraphy in breast cancer located in the upper lateral quadrant with additional projection imaging.

Mitsuru Koizumi; Etsuji Nomura; Yasuhiko Yamada; Tohohiro Takiguchi; Motoki Ishii; Takashi Yamashita; Keiichiro Tada; Seiichiro Nishimura; Kaoru Takahashi; Masujiro Makita; Takuji Iwase; Masataka Yoshimoto; Fujio Kasumi

Background: Sentinel node (SN) biopsy has been becoming a standard method for early stage breast cancer. Scintigraphic image of SN helps the biopsy procedure. It is reported that the scintigraphic detection rate is not 100%. The value of taking additional projection view in SN detection was assessed in breast cancer patients.Patients and Methods: Consecutive 114 breast cancer patients with upper lateral quadrant tumor were included in this study. After injection of99mTc-phytate, scintigram was taken at the projection of anterior oblique (AO) 30° view and an additional AO 60° view. Images were evaluated visually.Results: In 7 of 114 patients, an axillary hot node was hidden on the activity at the injected site on AO 30° view, and was visualized on AO 60° view. In 17 of 114 patients, the axillary hot node was seen as a hump from the injected activity, and was separate on AO 60° view. In 90 of 114 patients, the axillary hot node was separately seen on AO 30° view.Conclusion: Multi-directional views are helpful to depict the axillary sentinel nodes that are concealed behind the injected radioactivity.


Chemistry: A European Journal | 2009

Light-induced deformation of photoresponsive liquid crystals on a water surface.

Kunihiko Okano; Masato Shinohara; Takashi Yamashita

Photodeformation: Azobenzene derivatives showing a room-temperature liquid crystal (LC) phase exhibit photoinduced deformation on a water surface. While a droplet of a LC sample floating on the surface expands upon UV irradiation, a LC sample containing a solvent is condensed towards the center of the illuminated regions (see figure).


International Journal of Clinical Oncology | 2000

The bisphosphonate incadronate for bone metastases of breast cancer

Mitsuru Koizumi; Masao Kobayashi; Masahiko Furukawa; Takashi Yamashita; Etsuro Ogata

AbstractBackground. Bisphosphonates are bone resorption inhibitors which are effective in the treatment of diseases of increased bone turnover, such as hypercalcemia of malignancy and osteolytic bone metastasis. The safety and efficacy of incadronate, a third-generation bisphosphonate, were evaluated in breast cancer patients with bone metastases.nMethods. Fifteen breast cancer patients with bone metastasis were enrolled. Incadronates safety, its effectiveness in relieving bone pain, and its effects on bone metabolic markers and a tumor marker were assessed in 8 patients treated with a 10-mg IV infusion once a week for 5 weeks (10 mg × 5), 3 patients treated with a single 20-mg IV infusion (20 mg × 1), and 4 patients treated with a 20-mg IV infusion once a week for 5 weeks (20 mg × 5). Pain assessment was performed only in the patients with the repeated infusion regimens.nResults. All incadronate treatment regimens were administered without any serious adverse reactions. Minimal fever was noted in 6 patients, but it subsided without any treatment. Incadronate relieved bone pain in 10 of the 12 patients who received repeated infusions. Levels of bone resorption markers dropped transiently, but the decreases in the individual markers of bone resorption varied. Levels of bone formation markers did not change significantly. Levels of a tumor marker specific to breast cancer, carbohydrate antigen (CA)15-3 decreased in patients whose metastases were limited to bone.nConclusion. The third-generation bisphosphonate, incadronate, was administered safely at dosages of up to 20 mg once a week for 5 weeks. Incadronate reduced bone pain, bone resorption marker levels, and CA15-3 tumor marker levels in breast cancer patients with bone metastases.


International Journal of Clinical Oncology | 1999

Patterns of Care Study of radiation therapy for uterine cervix cancer in Japan: The influence of age on the process

Teruki Teshima; Hiroshi Ikeda; Mitsuyuki Abe; Gerald E. Hanks; Jean B. Owen; Masahiko Oguchi; Yutaka Hirokawa; Masahiro Hiraoka; Masamichi Nishio; Takashi Yamashita; Akira Naito; Yoichi Okazaki; Toshihiko Inoue

AbstractBackground. To improve the quality of radiation oncology in Japan, a Patterns of Care Study (PCS), a quality assurance program widely known in the United States, was introduced to Japan. In this study, the process, including work-up and treatment for uterine cervix cancer patients, was investigated to show nationwide variation by age.nMethods. From July 1996 through February 1997, PCS extramural audits were performed for 29 institutions nationwide. Medical charts for 432 patients with uterine cervix cancer treated between 1992 and 1994 were reviewed based on the PCS data format used in the US. The processes of radiation therapy for these patients were compared in two age groups – those aged ≥75 years (n = 132) and those aged <75 years (n = 300).nResults. There were significant differences by age group in medical background, indicating the fragility of the elderly and a relatively higher incidence of early-stage disease in the elderly by patient selection. Lower pelvic radiation doses were used for the elderly with advanced stage disease. There were no significant differences in unplanned breaks in external irradiation between the two age groups. Brachytherapy was used less commonly in the elderly group than in younger group (P = 0.0187). The dose range for brachytherapy did not show any significant difference between the two groups. Preliminary survival rates for the elderly were similar to those for the younger group.nConclusion. Radiation therapy was found to play an important role in the treatment of uterine cervix cancer in elderly as well as younger patients.


Chemistry of Materials | 2007

Dendrimer Generation Effects on Photodynamic Efficacy of Dendrimer Porphyrins and Dendrimer-Loaded Supramolecular Nanocarriers

Yuan Li; Woo Dong Jang; Nobuhiro Nishiyama; Akihiro Kishimura; Satoko Kawauchi; Yuji Morimoto; Sayaka Miake; Takashi Yamashita; Makoto Kikuchi; Takuzo Aida; Kazunori Kataoka


Breast Cancer | 2005

Classification of ipsilateral breast tumor recurrence after breast-conserving therapy: new primary cancer allows a good prognosis.

Seiichiro Nishimura; Kaoru Takahashi; Futoshi Akiyama; Masahiko Oguchi; Keiichiro Tada; Masujiro Makita; Takuji Iwase; Masataka Yoshimoto; Takashi Yamashita; Goi Sakamoto; Fujio Kasumi


Japanese Journal of Clinical Oncology | 2004

Improvement in the Prognosis of Japanese Breast Cancer Patients from 1946 to 2001—an Institutional Review

Masataka Yoshimoto; Keiichiro Tada; Haruko Hori; Akira Morota; Masahiko Tanabe; Seiichiro Nishimura; Kaoru Takahashi; Masujiro Makita; Takuji Iwase; Fujio Kasumi; Syunji Takahashi; Yoshinori Ito; Masahiro Oguchi; Takashi Yamashita; Futoshi Akiyama; Goi Sakamoto


Breast Cancer | 2006

A pilot study of wider use of accelerated partial Breast irradiation: Intraoperative margin-directed re-excision combined with sole high-dose-rate interstitial brachytherapy

Takayuki Nose; Yoshihumi Komoike; Ken Yoshida; Masahiko Koizumi; Kazuyoshi Motomura; Tsutomu Kasugai; Hideo Inaji; Kinji Nishiyama; Hiroki Koyama; Takuyo Kozuka; Kotaro Gomi; Masahiko Oguchi; Yutaka akahashi; Iori Sumida; Takashi Yamashita

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Masahiko Oguchi

Japanese Foundation for Cancer Research

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Kotaro Gomi

Japanese Foundation for Cancer Research

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Takayuki Nose

Japanese Foundation for Cancer Research

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Takuyo Kozuka

Japanese Foundation for Cancer Research

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