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Biomedical subjects

S Shumiya

Publications and source records attributed to S Shumiya.

41 records · Page 3Linked to original sources
PubMed1977

Persistence of Sendai virus in a mouse breeder colony and possibility to re-establish the virus free colonies.

An epizootic of Sendai virus infection occurred in a mouse breeder colony with respiratory signs, mortality, retarded growth in young and prolonged gestation period in adults. Thereafter, the infection persisted in this colony without any clinical signs and with 90 to 100% antibody positivity in adults. Weanlings had maternal antibodies and no pneumonic lesions. Antibodies were hardly detected in 6-week-old mice with high incidence of red hepatization or congestion in their lungs, but mice over 8 weeks of age had antibody without the lesions. After isolating weanlings and pregnant mice with antibodies from the infected colony, the isolated weanlings and offspring from the isolated dams became negative for Sendai virus antibodies.

Animals↗
PubMed1976

Carrier state of antibody and viruses in a mouse breeding colony persistently infected with Sendai and mouse hepatitis viruses.

In a large-scale mouse breeder colony persistently infected with Sendai and mouse hepatitis viruses, most adult breeders 8 wk or more of age were shown to have antibodies to both viruses when monitored over a periof of 20 mo. Antibody to Sendai virus, apparently transmitted from the dam, was detected in 76% and 2% of mice aged 3 and 4 wk. respectively, and 64% and 100% of mice aged 6 and 8 wk, respectively. By seroconversion of sentinel cage-mates, a Sendai virus-carrier state was demonstrated with 6-wk-old mice but not with those either 4 wk or 10 wk of age, suggesting that breeder candidates about 6 wk of age may play an important role in establishing and perpetuating Sendai infection in this breeding colony. With mouse hepatitis virus, however, mice aged 4 wk or older seem to be effective transmitters of the virus, while some of these mice were found to have antibody to the virus.

Age Factors↗
PubMedDate not supplied

Lens reconstruction after mature cataract in SCR rat.

PURPOSE: To conduct a long-term observation study of SCR rats that had developed a mature cataract at 11 weeks of age at 3-month intervals until the rats were 12 months old. METHODS: Lenses of 15 rats were examined with both light and electron microscopes. RESULTS: At 12 weeks, opacity was observed in the perinuclear zone and the cortical intermediate layer. Liquefaction of the posterior subcapsular area and regression of cortical superficial fibers were also observed at this stage. Epithelial cells at the anterior polar area were multilayered. At 12 months, the lens recovered as a result of the regenerated lens fibers in the intermediate layer and the cortical superficial layer, although the opacity remained in the perinuclear zone. The multilayered cellular structure in the center of the epithelium returned to its original monolayer form. However, the equatorial epithelial cells became vacuolated and swollen with age, showing regression from the bow region. CONCLUSIONS: These results suggest that the decrease of opacity in SCR rats is merely a temporary phenomenon that reflects the differentiating and metabolizing functions of the epithelial cells. With initiation of epithelial regression, the regeneration of the lens fibers ceased, suggesting that further decrease in opacity was no longer possible.

Animals↗
PubMedDate not supplied

Peptidases play an important role in cataractogenesis: an immunohistochemical study on lenses derived from Shumiya cataract rats.

The role of proteolytic enzymes in Shumiya cataract rats in alterations to lens proteins during cataract formation was studied immunohistochemically using antibodies against exopeptidases, such as lysosomal dipeptidyl peptidase II (DPP II), cytosolic dipeptidyl peptidase III, and soluble and membrane-bound alanyl aminopeptidases, and against cytosolic endopeptidases such as mu- and m-calpains, and 20S proteasome. AlphaB-crystallin was detected as a proteolytic marker in the lenses. A constant immunoreactivity against all the antibodies employed was observed in the lens epithelium independent of the strain and age of the rats. A weak immunoreactivity against exo- and endopeptidases and an intense reactivity against alphaB-crystallin were observed in the lens fibres of control rats at all ages. The immunoreactivity of these peptidases in lens fibres increased with age in cataract rats, but that of alphaB-crystallin decreased. No reactivity against exo- and endopeptidases was seen in the perinuclear region of lenses of control rats at all ages or in Shumiya cataract rats at 8 and 10 weeks of age, but an intense reactivity against these peptidases was observed in the lens perinuclear region of lenses in cataract rats at 12 and 14 weeks of age. AlphaB-crystallin immunoreactivity was observed with ordered striations in the lens perinuclear region of all control rats whereas the striations in this area of cataract rat lens were disorganized. Membrane-bound alanyl aminopeptidase was detected feebly in the lens epithelium and fibres of both types of rat at all weeks of age. These findings indicate that exo- and endopeptidases, except for membrane-bound alanyl aminopeptidase, are expressed intensively and are age-dependent. Conversely, the amount of alphaB-crystallin decreased with age in lens fibres of cataract rats. Calpains (mu- and m-), 20S proteasome, dipeptidyl peptidases II and III and soluble alanyl aminopeptidase are thought to induce lens opacification kinetically during cataract formation in Shumiya cataract rats through the intracellular turnover of lens proteins.

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