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723 results on '"Nishioka, Kiyoshi"'

227. Dual Catalyst System forAsymmetric Alternating Copolymerizationof Carbon Dioxide and Cyclohexene Oxide with Chiral Aluminum Complexes:Lewis Base as Catalyst Activator and Lewis Acid as Monomer Activator.

Author

Nishioka, Kiyoshi, Goto, Hidetoshi, and Sugimoto, Hiroshi

Subjects
*COPOLYMERIZATION, *ASYMMETRY (Chemistry), *ENANTIOSELECTIVE catalysis, *CARBON dioxide, *CYCLOHEXENE, *METAL complexes, *ALUMINUM compounds, *LEWIS acids
Abstract

Optically active aluminum complexes such as Schiff base,binuclearβ-ketoiminate, and bisprolinol complexes were found to promoteasymmetric alternating copolymerizations of carbon dioxide and cyclohexeneoxide. The aluminum Schiff base complexes–tetraethylammoniumacetate afforded isotactic poly(cyclohexene carbonate)s with low enantioselectivities.Lewis bases having two coordinating sites were utilized to enhanceactivity and selectivity based on the binuclear structure of the aluminumβ-ketoiminate clarified by X-ray crystallography. [2gAlMe]2–bulky bisimidazole produced the alternatingcopolymer with high enantioselectivity (62% ee). The polymerizationis considered to preferentially proceed at more crowded, enantioselectivesite owing to coordination of bulky Lewis bases to aluminums in lessenantioselective sites. 32AlMe–2-picolinealso exhibited a high enantioselectivity (67% ee). Methylaluminumbis(2,6-di-tert-butyl-4-methylphenoxide) was appliedto perform faster and more enantioselective copolymerizations at lowtemperature (82% ee). The asymmetric copolymerizations were foundto be significantly dependent on size of epoxide, temperature, andkind/amount of activators. [ABSTRACT FROM AUTHOR]

Published
2012
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229. Annular Erythema.

Author

Katayama, Ichiro, primary, Teramoto, Noriko, additional, Arai, Harue, additional, Nishioka, Kiyoshi, additional, and Nishiyama, Shigeo, additional

Published
1991
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237. Japanese Cedar Pollen as an Exacerbation Factor in Atopic Dermatitis: Results of Atopy Patch Testing and Histological Examination.

Author

Yokozeki, Hiroo, Takayama, Kaoru, Katayama, Ichiro, and Nishioka, Kiyoshi

Subjects
ATOPIC dermatitis, ALLERGIES, SKIN inflammation, CRYPTOMERIA japonica, POLLEN, DERMATOLOGY
Abstract

Atopy patch testing with Japanese cedar pollen extract has been used to investigate patients with atopic dermatitis whose condition is exacerbated by contact with Japanese cedar pollen. Comparative atopy patch testing, scratch tests, and assays for total IgE and specific IgE were performed in 74 patients with atopic dermatitis, 5 patients with Japanese cedar pollinosis and 15 control subjects. A skin biopsy was performed on any sites that were positive to Japanese cedar pollen patch test. The results after 48 h of atopy patch testing were compared with the patient's history, skin scratch test and specific IgE. Twenty-two of the 74 patients (30%) had a history of exacerbation every spring after contact with Japanese cedar. Of these patients 68% showed a positive reaction to Japanese cedar pollen extract, as did 21% of patients with atopic dermatitis without a history of exacerbation by Japanese cedar pollen, 20% of patients with Japanese cedar pollinosis without eruption and 7% of control subjects. A histological examination revealed eczematous changes and infiltration of lymphocytes and eosinophils in atopy patch testing positive sites. In conclusion, atopy patch testing with Japanese cedar pollen extract is a useful method for investigating trigger factors for eczematous skin lesions in a subgroup of patients with atopic dermatitis. [ABSTRACT FROM AUTHOR]

Published
2006
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248. Cellular and molecular mechanisms of bleomycin-induced murine scleroderma: current update and future perspective.

Author

Yamamoto, Toshiyuki and Nishioka, Kiyoshi

Subjects
*SCLERODERMA (Disease), *BLEOMYCIN, *FIBROBLASTS, *INFLAMMATORY mediators, *PATHOLOGICAL physiology, *LABORATORY mice
Abstract

Yamamoto T, Nishioka K. Cellular and molecular mechanisms of bleomycin-induced murine scleroderma: current update and future perspective.Scleroderma is a fibrotic condition characterized by immunologic abnormalities, vascular injury and increased accumulation of matrix proteins in the skin. Although the aetiology of scleroderma is not fully elucidated, a growing body of evidence suggests that extracellular matrix overproduction by activated fibroblasts results from complex interactions among endothelial cells, lymphocytes, macrophages and fibroblasts, via a number of mediators. Cytokines, chemokines and growth factors secreted by inflammatory cells and mesenchymal cells (fibroblasts and myofibroblasts) play an important role in the fibrotic process of scleroderma. Recently, we established a murine model of scleroderma by repeated local injections of bleomycin. Dermal sclerosis was induced in various mouse strains, although the intensity of dermal sclerosis varied among various strains. Histopathological and biochemical analysis demonstrated that this experimental murine scleroderma reflected a number of aspects of human scleroderma. Further investigation of the cellular and molecular mechanisms of inflammatory reaction, fibroblast activation and extracellular matrix deposition following dermal injury by bleomycin treatment will lead to the better understanding of the pathophysiology and the exploration of effective treatment against scleroderma. This review summarizes recent progress of the cellular and molecular events in the pathogenesis of bleomycin-induced scleroderma; moreover, further perspective by using this mouse model has been discussed. [ABSTRACT FROM AUTHOR]

Published
2005
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