Asian Science Citation Index is committed to provide an authoritative, trusted and significant information by the coverage of the most important and influential journals to meet the needs of the global scientific community.  
ASCI Database
308-Lasani Town,
Sargodha Road,
Faisalabad, Pakistan
Fax: +92-41-8815544
Contact Via Web
Suggest a Journal
 
Articles by T Sasaki
Total Records ( 8 ) for T Sasaki
  W Koizumi , T Akiya , A Sato , K Yamaguchi , T Sakuyama , N Nakayama , S Tanabe , K Higuchi , T Sasaki , T Sekikawa and The Tokyo Cooperative Oncology Group (TCOG GI Group)
  Objective

A multicenter trial was conducted to evaluate the efficacy and safety of paclitaxel every 2 weeks in patients with advanced or recurrent gastric cancer who had previously received fluoropyrimidine-based chemotherapy.

Methods

The subjects were patients with gastric cancer who had disease progression or recurrence while receiving fluoropyrimidine-based chemotherapy. All patients had adequate major organ functions with an Eastern Cooperative Oncology Group performance status (PS) of 0–2. Paclitaxel 140 mg/m2 was administered intravenously on days 1 and 15 of a 4-week cycle. The primary endpoint was the response rate. Secondary endpoints were progression-free survival (PFS), overall survival and safety.

Results

Response was assessable in 40 of 41 enrolled patients. Their median age was 63 (range: 48–77) years, and PS was 0 in 22 patients, 1 in 13 and 2 in 5. Previous treatment included S-1 (1 M tegafur–0.4 M gimestat–1 M otastat potassium) monotherapy in 32 patients and S-1-based combination therapy in 5. The median number of administered courses of paclitaxel was 3.5 (1–14). The response rate was 17.5% (95% confidence interval: 7.3–32.8%, partial response: 7, stable disease: 21, progressive disease: 10 and not evaluable: 2). The disease control rate was 70.0%, the median PFS was 111 days and the median overall survival was 254 days. Major adverse events of Grade 3 or 4 were neutropenia (27.5%), anemia (12.5%), diarrhea (2.5%) and sensory neuropathy (2.5%).

Conclusions

Biweekly paclitaxel seemed to be one of the useful chemotherapies after failure of fluoropyrimidine-based treatment in patients with advanced or recurrent gastric cancer.

  K Nakamura , K Ogawa , T Sasaki , H Onishi , M Koizumi , M Araya , N Mukumoto , M Mitsumori , T Teshima and Japanese Patterns of Care Study Working Subgroup of Prostate Cancer
  Objective

The purpose of this study is to identify the treatment planning process for Japanese patients with localized prostate cancer.

Methods

The Patterns of Care Study conducted a random survey of 61 institutions nationwide. Detailed information was collected on prostate cancer patients without distant metastases who were irradiated during the periods 2003–05. Radiation treatment planning and delivery were evaluated in 397 patients who were treated radically with external photon beam radiotherapy.

Results

Computed tomography data were used for planning in ~90% of the patients. Contrast was rarely used for treatment planning. Simulations and treatments were performed in the supine position in almost all patients. Immobilization devices were used in only 15% of the patients. Verification of the treatment fields using portal films or electric portal imaging devices was performed in most of the patients. However, regular or multiple verifications in addition to initial treatment and/or portal volume changes were performed in only 30% of the patients. Typical beam arrangements for treatment of the prostate consisted of a four-field box. Three-dimensional conformal techniques were applied less frequently in non-academic hospitals than in academic ones. Modernized multileaf collimators with leaf widths ≤10 mm were used in about two-thirds of the patients. Although the total doses given to the prostate were affected by the leaf widths, there were no significant differences between leaf widths of 5 and 10 mm.

Conclusions

The results of the survey identified certain patterns in the current treatment planning and delivery processes for localized prostate cancer in Japan.

  T Ishikawa , D Shimizu , T Sasaki , S Morita , M Tanabe , I Ota , K Kawachi , A Nozawa , T Chishima , Y Ichikawa , I Endo and H. Shimada
  Objective

We investigated the pathological effects of neoadjuvant chemotherapy based on the human epidermal growth factor receptor 2 in operable breast cancer.

Methods

This prospective clinical study was a pilot involving 63 female patients. Before surgery, patients with tumors overexpressing human epidermal growth factor receptor 2 received four cycles of 60 mg/m2 anthracycline and 600 mg/m2 cyclophosphamide every 3 weeks, whereas those whose tumors did not overexpress human epidermal growth factor receptor 2 received four cycles of 75 mg/m2 docetaxel and 600 mg/m2 cyclophosphamide every 3 weeks. A quasi-pathological complete response (i.e. absence of invasive tumor or only focal residual tumor cells) was the primary endpoint, with compliance and predictors for each regimen as secondary endpoints. If a quasi-pathological complete response was not achieved, then crossover to the alternative treatment was recommended.

Results

The quasi-pathological complete response rate was 36.5% (23 of 63) overall, 27.8% (5 of 18) for the anthracycline and cyclophosphamide regimen and 40.0% (18 of 45) for the docetaxel and cyclophosphamide regimen. Docetaxel and cyclophosphamide treatment induced a quasi-pathological complete response in most patients with triple-negative tumors (15 of 19). The relative dose intensity was 97.3% for the anthracycline and cyclophosphamide regimen and 96.6% for the docetaxel and cyclophosphamide regimen. Quasi-pathological complete response to the docetaxel and cyclophosphamide regimen was associated with low estrogen receptor and progesterone receptor expression and high MIB-1 and topoisomerase II expression, in univariate analyses, but only with low estrogen receptor expression in multivariate analysis.

Conclusions

Selecting neoadjuvant chemotherapy regimens on the basis of individual human epidermal growth factor receptor 2 status improved efficacy, with docetaxel and cyclophosphamide treatment showing particular promise in tumors with the potential to be highly malignant.

  Y Nakai , H Isayama , T Sasaki , N Sasahira , H Kogure , K Hirano , T Tsujino , H Ijichi , K Tateishi , M Tada , M Omata and K. Koike
  Objective

We investigated the impact of S-1 on the prognosis of patients with gemcitabine-refractory pancreatic cancer.

Methods

A total of 108 patients with gemcitabine-refractory pancreatic cancer were divided by the time of S-1 introduction in our institution: 47 patients who experienced progressive disease before February 2005 (pre-S-1 group) and 61 patients showed progressive disease after February 2005 (post-S-1 group). Introduction rates of second-line chemotherapy and survival were compared. Prognostic factors for residual survival were analyzed using the Cox proportional hazards model.

Results

Introduction rates of second-line chemotherapy were 12.8% in the pre-S-1 group and 45.9% in the post-S-1 group. Second-line chemotherapy was administered to 34 patients: 29 using S-1, 4 using 5-fluorouracil-based chemoradiation and 1 using 5-fluorouracil. The objective response rate, progression-free survival and overall survival for second-line chemotherapy with S-1 were17.2%, 2.5 and 7.7 months, respectively. By the introduction of S-1 in our institution, residual survival was prolonged from 3.1 months in the pre-S-1 group to 6.7 months in the post-S-1 group (P < 0.001). Overall survival from the initiation of gemcitabine was 8.8 months in the pre-S-1 group and 11.3 months in the post-S-1 group (P = 0.013). Multivariate analysis identified the post-S-1 group (hazard ratio, 0.43; P = 0.001), gender, performance status, liver metastasis, and lactate dehydrogenase and C-reactive protein levels at progressive disease for gemcitabine to be prognostic factors for residual survival.

Conclusions

The introduction of S-1 might improve the prognosis of patients with gemcitabine-refractory pancreatic cancer.

  H Sawada , T Sasaki , F Hosokawa , S Yuasa , M Terao , M Kawazoe , T Nakamichi , T Kaneyama , Y Kondo , K Kimoto and K. Suenaga
 

A new concept of a spherical aberration correction system using three dodecapoles is proposed. The system compensates for higher order aberration of 6-fold astigmatism, which generally limits a uniform phase area for image forming and probe forming in an electron microscope with a conventional two-hexapole corrector. Triple 3-fold astigmatism field is used to correct the spherical aberration of the objective lens, and the total 3-fold astigmatism is eliminated by their combination. The optimum azimuth relationship among three dodecapoles is calculated to eliminate the 6-fold astigmatism. The principle of the method was verified using a mathematically complex representation. This new concept was experimentally tested with a scanning transmission electron microscope at 60 kV acceleration. The 6-fold astigmatism was certainly compensated and the coherent convergent angle became almost twice compared to a conventional double hexapole system.

  S Yanaka , M Kudou , Y Tanaka , T Sasaki , S Takemoto , A Sakata , Y Hattori , T Koshi , S Futaki , K Tsumoto and T. Nakashima
 

Staphylococcal enterotoxin B (SEB), a toxin produced by Staphylococcus aureus, causes food poisoning and other fatal diseases by inducing high levels of pro-inflammatory cytokines. These cytokines are released from CD4+ T cells and major histocompatibility complex (MHC) class II antigen-presenting cells, which are activated through binding of wild-type (WT) SEB to both the MHC class II molecule and specific T-cell receptor Vβ chains. Here, we focused on a trypsin/cathepsin cleavage site of WT SEB, which is known to be cleaved in vivo between Lys97 and Lys98, located within the loop region. To know the function of the cleavage, an SEB mutant, in which both of these Lys residues have been changed to Ser, was examined. This mutant showed prolonged tolerance to protease cleavage at a different site between Thr107 and Asp108, and structural analyses revealed no major conformational differences between WT SEB and the mutant protein. However, differential scanning calorimetric analysis showed an increase in enthalpy upon thermal denaturation of the mutant protein, which correlated with the speed of cleavage between Thr107 and Asp108. The mutant protein also had slightly increased affinity for MHC. In the in vivo experiment, the SEB mutant showed lower proliferative response in peripheral blood mononuclear cells and had lower cytokine-induction activity, compared with WT SEB. These results highlight the importance of the flexible loop region for the functional, physical and chemical properties of WT SEB, thus providing insight into the nature of WT SEB that was unrevealed previously.

  M Iida , T Sasaki and H. Komatani
 

To unravel the growth inhibition mechanism of Polo-like kinase 3 (Plk3), the effect of overexpression of Plk3 was examined in 293T cells. Cell rounding, changes in actin organization and cellular detachment were induced by Plk3 transfection in a kinase activity-dependent manner. Although apoptosis was not observed, Plk3 overexpression suppressed cellular growth in a long-term colony-forming assay. Because both Plk3 and Ras affect F-actin organization, the effect of co-transfection of Plk3 and Ras was evaluated. Adhesion was synergistically lost by co-transfection of these two genes, compared with transfection of Plk3 alone. Furthermore, overexpression of Plk3 caused long-term growth suppression in Ras-transformed NIH3T3. Collectively, Plk3 activation might cause cytoskeleton re-organization and result in growth suppression more pronouncedly in Ras pathway-activated cells.

 
 
 
Copyright   |   Desclaimer   |    Privacy Policy   |   Browsers   |   Accessibility