Search

Your search keyword '"Kubota, Sunao"' showing total 46 results
Start Over Author "Kubota, Sunao"
46 results on '"Kubota, Sunao"'

39. Thermoreversible gelation on cooling and on heating of an aqueous gelatin–poly(N-isopropylacrylamide) conjugate

Author

Yoshioka, Hiroshi, Mori, Yuichi, Tsukikawa, Satoshi, and Kubota, Sunao

Abstract

A polymer conjugate composed of 43 wt% gelatin and 57 wt% poly(N-isopropylacrylamide) (PNIPAAm) was prepared. The dynamic viscoelastic properties of an aqueous solution of the conjugate at the concentration of 5 wt% were examined. The solution was viscous fluid at 30°C and turned into an elastic homogeneous hydrogel upon heating above 34°C or upon cooling below 10°C. The resultant hydrogels turned back into a solution at the opposite temperature cycles of the gelation. It is considered that the driving force of the gelation is the intermolecular hydrophobic interaction of PNIPAAm blocks or the intermolecular helix association of gelatin blocks, respectively, on heating or on cooling. © 1998 John Wiley & Sons, Ltd.

Published
1998
Full Text
View/download PDF

46. New chemosensitivity test using a thermo-reversible gelation polymer for recurrent gynecologic cancer patients and a preliminary study of mechanisms of anticancer drug resistance.

Author

Ohara T, Kiguchi K, Tsukikawa S, Sato S, Kobayashi Y, Ishizuka B, and Kubota S

Subjects
Cell Culture Techniques, Drug Resistance, Neoplasm, Female, Gels, Humans, Multidrug Resistance-Associated Protein 2, Neoplasm Recurrence, Local, Polymers, Temperature, Tumor Cells, Cultured, Antineoplastic Agents pharmacology, Culture Media, Drug Screening Assays, Antitumor methods, Genital Neoplasms, Female pathology
Abstract

Objectives: TGP (thermo-reversible gelation polymer) is a high molecular compound that has so-gel transmitting temperature of 221C Since solid cancer tissue grows in this polymer three-dimensionally, and fibroblasts scarcely grow in it, TGP is suitable for chemosensitivity assays for solid tumors. In this study, a chemosensitivity test using TGP was applied to recurrent gynecologic cancer patients in order to evaluate its utility and efficacy. In some ovarian cancer cases, expression of anticancer drug resistance-related proteins was also analyzed., Methods: Recurrent tumor tissues were surgically obtained with informed consent. After these tissues were minced and incubated for 4 days with CDDP, mitomycin C, 5-fluorouracil, paclitaxel, and CPT-11, the sensitivity against these drugs was estimated. Western blotting was performed in 8 recurrent ovarian cancer tissues in order to analyze the expression of Bcl-2, MRP2, BCRP, and GST-pi., Results: The total evaluability rate of this assay was 90.6% (29/32). Sensitive drugs could be determined in 5 of 7 ascites samples (71.4%) and in 2 of 3 intra-tumoral fluid samples (66.7%). The overall clinical response rate of chemotherapy determined by these results was 50.0%. There were significant correlations between the IC50 of CDDP and Bcl-2, BCRP, GST-pi, and between that of 5-FU and MRP 2., Conclusions: Although this was a preliminary study, the chemosensitivity test using this new material appears to be useful for designing 'made-to order' salvage chemotherapy for pretreated recurrent gynecologic patients. In order to overcome multidrug resistance, the mechanisms of multidrug resistance should be further investigated.

Published
2005
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results