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M Takehana

Publications and source records attributed to M Takehana.

45 records · Page 3Linked to original sources
PubMed1983

Analysis of low molecular weight fractions in human senile cataractous lens.

Previous studies have suggested that changes occur in low molecular weight proteins during the progression of human senile cataract. In this report we have employed the reverse phase mode of high performance liquid chromatography (HPLC) and characterized the patterns of changes in the fractions of low molecular weight substances. Two different types of cataractous lenses, brown and yellow types, were used. Classification of cataract stages in each type was determined by measuring the Na+/K+ ratio in each lens. The profile of low molecular weight substances loosely bound to the reverse phase column changed significantly during cataract progression. In the brown type cataractous lenses, however, the low molecular weight substances changed after the middle stage of cataract progression, while in the yellow type cataractous lenses, the changes started during the early stages of cataract development. These experiments demonstrated that the reverse phase mode of HPLC is a sensitive and specific method for characterization of the quantitative differences in low molecular weight compounds during the progression of human senile cataract.

Aged↗
PubMedDate not supplied

Ascorbate free radical reductase activity in vertebrate lenses of certain species.

PURPOSE: To clarify the function of ascorbate free radical (AFR) reductase in the antioxidation system of different vertebrate lenses. METHODS: The soluble and insoluble fractions were prepared from bullfrog, guinea pig, rat, rabbit, swine, and bovine lenses, and membrane-bound enzymes in the insoluble fraction were extracted by 0.3% Triton X-100. Ascorbate free radical reductase and diaphorase activities in each fraction were determined. RESULTS: Ascorbate free radical reductase activity in the lens soluble fraction was the highest in the bullfrog. That in the guinea pig and rabbit was at the next level. There was only a little activity in rat and swine lenses, and none was detected in the bovine lenses. However, a large species difference in AFR reductase activity was not observed in the 0.3% Triton X-100 extracts. Diaphorase activity was three to nine higher than AFR reductase activity in the soluble fractions of bullfrog, guinea pig, and rabbit. In the 0.3% Triton X-100 extracts of all animal species used, it was very high, 108 to 311 times the AFR reductase activity. CONCLUSION: These results indicate that the lens soluble and membrane-bound AFR reductase in the different animals may be individual enzyme molecules and have different antioxidative functions. Because the lenses of bullfrog, guinea pig, and rabbit are known to contain a near-ultraviolet (UV) light-absorbing compound, reduced pyridine nucleotide, at a high concentration, the soluble AFR reductase activity is expected to be high in the vertebrate lenses with a near-UV light filter, to enhance the antiphoto-oxidation capacity of ascorbate.

Animals↗
PubMedDate not supplied

Phakomatous choristoma of the eyelid: immunohistochemical observation.

This article reports the first case of phakomatous choristoma of the eyelid in Japan. The tumor occurred in a 2-week-old boy and was located in the left lower lid near the inner canthus. An immunohistochemical study of this rare, congenital tumor was performed. The immunohistochemical analysis revealed that the epithelial cells of this tumor showed positive staining for vimentin, S-100 protein, and neuron-specific enolase, while they had no immunoreactivity for cytokeratin, glial fibrillary acidic protein, epithelial membrane antigen, or a macrophage marker. Both the epithelial cells and the central contents of the islands in this tumor showed positive staining with anti-human alpha crystallin monoclonal mouse IgG. These results strongly indicated that a phakomatous choristoma was of a lenticular origin.

Choristoma↗