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Biomedical subjects

K Tsunoda

Publications and source records attributed to K Tsunoda.

At least 181 records · Page 10Linked to original sources
PubMed1975

Pathogenicity for several laboratory animals of toxoplasma oocysts originated from naturally infected cats.

The pathogenicity of four strains, O-1, O-2, O-3, and O-4, of Toxoplasma isolated in the form of oocyst from the feces of naturally infected cats was examined for such laboratory animals as mice, rats, rabbits, guinea pigs, and dogs, in comparison with that of the Beverley strain. Suspensions of seven graded doses of oocysts of each strain ranging from 1.0 X 10(-1) to 1.0 X 10(5) were inoculated orally into seven groups of five mice each. The O-1, O-2, and O-3 strains were as pathogenic for mice as the Beverley strain, but the O-4 strain was not so pathogenic as any other strain. Rats, rabbits, guinea pigs, and dogs were inoculated orally with around 1.0 X 10(5) oocysts. The four O strains were not so severly pathogenic for rats and rabbits as to cause death. The O-2 and O-3 strains showed strong pathogenicity for guinea pigs, almost all of which, when inoculated with them, died after manifesting severe clinical symptoms. The pathogenicity of the O-1 and O-2 strains showed essentially the same tendency for dogs as for any other animal. In inoculation with oocysts, as well as with proliferative forms or cysts, the same pathogenicity was not observed in different strains, even if the same species of host animals was used. On the contrary, the same pathogenicity was not always found even in one strain when a different species of animals was used.

Administration, Oral↗
PubMed1975

Destructive effect of heating against toxoplasma oocysts.

Heating was examined for destructive effect against Toxoplasma oocysts, both unsporulated and sporulated, of the O-1 and O-3 strains. Sporulation-inhibition rates were measured by counting sporulated and unsporulated oocysts in each examination. As a result, the sporulation of Toxoplasma oocysts was completely inhibited by exposure to 60 or 70 degrees C for 10 seconds, 55 degrees C for 30 seconds, 50 degrees C for 2.5 minutes. 45 degrees C for 1 hour, or 37 degrees C for 48 hours. When examined by the mouse inoculation method, the infectivity of sporulated oocysts became extinct after heating at 90 degrees C for 30 seconds, 80 degrees C for 1 minute, 70 degrees C for 2 minutes, 55 or 60 degrees C for 15 minutes, or 50 degrees C for 30 minutes. It was confirmed that heating was effective for the sterilization of Toxoplasma oocysts.

Animals↗