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Biomedical subjects

O Uchida

Publications and source records attributed to O Uchida.

51 records · Page 3Linked to original sources
PubMed1989

[Combined long-term toxicity/carcinogenicity test of alpha-bromocinnamic aldehyde (BCA) applied to female mouse skin].

Bromocinnamic aldehyde (BCA), an antibacterial/antifungal agent, was tested for its chronic toxicity/carcinogenicity in female Slc:ddY mice. The animals received 0.25%, 1.0% and 4.0% of BCA dissolved in olive oil applied to the shaved back skin area twice a week for 79 weeks. The control group received olive oil alone under similar conditions. In addition to these animals, 5 animals in each group were killed at 6 and 12 months for investigation of the time-related toxic effect of BCA. A slight inhibition of body weight increase and a slight decrease in the survival rate were seen in the 4.0% BCA-treated group. No significant changes were observed in hematological parameters at 6, 12 and 18 months. In chemical biochemistry determination in the blood at 6 and 12 months, a significant decrease in non-esterified fatty acid and phospholipid values was observed in the experimental groups. Histopathologically, necrosis, scabbing, cell infiltration and thickening of the epidermis were noted at the site of application in the 4.0% BCA group. Moreover, extramedullary hematopoiesis and amyloid degeneration were detected in the spleen, while the incidence of adenomas in the lung decreased with a dose-response. These changes seemed to be the result of a non-specific inflammatory reaction to the irritation effects of the agent on the skin. No significant differences in the incidence of tumors were found between the control and experimental groups, not only at the site of application but also in other organs, although lung adenomas decreased dose-dependently in all treated groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Aldehydes↗
PubMed1985

[Local irritation of isotonic acetic acid solutions of the rabbit M. vastus lateralis and confirmation of the injected sites].

One ml of 0.106%, 0.425% or 1.7% acetic acid (AA) solution, isotonic to physiological saline solution, was injected into the M. vastus lateralis of male Japanese white rabbits. Two, 7, 14 and 21 days after the injections, the rabbits were autopsied, and the removed muscles were observed macroscopically. After fixation with 10% neutral formalin, they were examined histologically. Hemorrhage and white degeneration of the muscles were grossly observed in 0.106%, 0.425% and 1.7% AA at 2 days. These lesions disappeared at 7 days and thereafter in 0.106% AA, and at 14 days and thereafter, except for one animal, in 0.425% AA. In 1.7% AA, these lesions were observed until 21 days, but gross hemorrhage began to recover at 21 days. The size of the lesion, which was expressed as a product of the major axis (mm) and minor axis (mm) of the lesion, showed reduction over time, especially in 1.7% AA. Histologically, swelling, necrosis and calcification of the muscle fibers and cell infiltration, hemorrhage and dilatation in the interstitium were observed after the injections of 0.106%, 0.425%, and 1.7% AA. At 7, 14 and 21 days, regeneration of the muscle fiber and fibrosis in the interstitium were observed. The injected sites were examined by injecting a chip of test-tube brush as a marker. In 20 (83%) of 24 cases, it was ascertained that the markers were injected into the M. vastus lateralis. The markers were found in the M. vastus intermedius in 3 out of 4 other cases and in the intermuscular tissue between the M. vastus lateralis and M. tensor fasciae latae in one case.

Acetates↗
PubMed1984

Spontaneous tumors of the nervous system and associated organs and/or tissues in rats.

Spontaneous tumors of the nervous system and associated organs and/or tissues in 346 male and 346 female F344/DuCrj rats and 200 male and 177 female Slc:Wistar rats were examined. The main neurogenic tumors observed were gliomas and neurinomas, which were detected in both strains of rats. Out of 7 gliomas, 6 were found in the brain and 1 in the spinal cord, and out of 4 neurinomas, 2 were in the trigeminal nerves and the other 2 were in the spinal nerves. In addition, other types of tumors (2 granular cell tumors in the brain, 1 pinealoma, 3 ganglioneuromas in the adrenal gland, 1 undifferentiated carcinoma in the nasal cavity and 1 chordoma in the posterior neck region) were observed.

Animals↗
PubMedDate not supplied

Spontaneous diabetes-like syndrome in WBN/KOB rats.

Spontaneous hyperglycemia, glycosuria, hypoinsulinemia, and glucose intolerance were observed in some WBN/Kob rats, at about 9 months of age, and in all at the age of 17 months. Females did not present this pathology. Histopathologic examination of the pancreas revealed severe changes in male rats at the age of 3 months. Between 3 and 6 months of age a distinct infiltration of inflammatory cells was found around islets and among adjacent acinar cells. At the same time, marked fibrosis was seen around the pancreatic ducts and blood vessels. With advancing age the fibrous tissue gradually invaded extensive areas of the pancreas where also the islets became involved in fibrotic degeneration. At 17 months of age and later, an obvious decrease in islet number and size (less than 50 mu in diameter) was observed, even in relatively unaffected areas of the organ. Frequent bilateral cataracts began to appear at about 15 months of age. Opacities were first observed in the periphery of the lens, then increased rapidly in intensity and extended centripetally. Nineteen-month-old male rats were hypersensitive to exogenous insulin, but showed no significant decrease in blood glucose level when treated with oral tolbutamide. These results suggest that these rats suffered from a decreased insulinogenic response.

Aging↗