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Biomedical subjects

K Imaeda

Publications and source records attributed to K Imaeda.

30 records · Page 2Linked to original sources
PubMed1985

Effect of oxygen and superoxide anion on mutation rate in Ames test.

Effects of oxygen and superoxide anion to mutation rate were examined using the method of Ames. As test samples, 3-methylcholanthrene or 3,4-benzpyrene dissolved in squalene was used. In order to increase the concentration of dissolved oxygen in the medium during preincubation, oxygen was bubbled into the medium. Various combinations of xanthine oxidase, superoxide dismutase and hypoxanthine were used with an intent of changing the concentration of superoxide anion in the medium during the preincubation. An increase in the concentration of dissolved oxygen and superoxide anion resulted in a lower mutation rate, clearly showing the relationships of mutation rate with oxygen and with superoxide anion.

Animals↗
PubMed1984

The possible role of squalene and its peroxide of the sebum in the occurrence of sunburn and protection from the damage caused by U.V. irradiation.

To clarify the role of squalene peroxide in the occurrence of skin damage from sunburn, the optimum condition of squalene peroxidation and the effect of squalene peroxide on cutaneous tissue were examined. Peroxidation of squalene was more easily induced than palmitoleic acid and oleic acid in the unsaturated lipid occurred in sebum. The peroxidation of squalene gradually occurred by U.V. irradation, and it is parallel to increases in the malonyldialdehyde production (production of lipoperoxide). This peroxidation easily carries out in the case of high temperature (40 degrees C than 30 degrees C), and in the case of low pH. Good correspondence was recognized among the spectrum of natural daylight, U.V. absorption spectrum of squalene and erythema curve. Squalene and its peroxide have an important role in the occurrence of sunburn, and/or protection from damage caused by U.V. irradiation.

Animals↗
PubMedDate not supplied

Multiple parapapillary choledochoduodenal fistulas with ampullary carcinoma.

Only very rarely do multiple parapapillary choledochoduodenal fistulas occur concurrently with ampullary carcinoma. The following presents just such a case, which occurred in a 51 year-old Japanese female hospitalized for epigastralgia. Gastrointestinal fiberscopy (GIF) showed abnormal swelling of Vater's papilla. She was diagnosed as having ampullary carcinoma and choledochoduodenal fistulas, as determined by hypotonic duodenography (HDG), endoscopic retrograde cholangiopancreatography (ERCP) and from the histopathology of the ampullary mucosal biopsy. Pancreatoduodenectomy was performed. We postulated that the multiple fistulas were formed on the longitudinal fold of Vater's papilla by an ampullary carcinoma, and that the fistulas played a major role in bile drainage. As a result, jaundice was not seen throughout the entire clinical course. We report on the mechanism of fistula formation, with a review of the recent literature.

Ampulla of Vater↗