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Biomedical subjects

T Kitamura

Publications and source records attributed to T Kitamura.

At least 901 records · Page 50Linked to original sources
PubMed1973

Differential diagnosis of variola viruses by microfocus assay.

Variola virus was identified by means of a method involving the formation of microfoci on microplate cultures of HeLa cells. It was possible to distinguish between variola major and variola minor viruses within 48 h of receipt of the specimens by determining the temperature sensitivity of focus formation.

Bacteriological Techniques↗
PubMed1973

Assay of variola virus on microtiter plates and its application to the neutralization test.

It was established that microfocus assay of the variola virus in HeLa cell cultures on Microtiter plates is a suitable method for titrating the virus in numerous specimens of small volume. The variola foci were formed within 48 hours of inoculation, and the standard error for the number of foci per well did not exceed 15%, with 96 flat-bottomed wells (6 mm diameter) containing 0.1 ml per well of the culture media on a plastic plate replacing 96 Petri dishes in the standard assay procedures. Microfocus assay was successfully applied to the quantification of neutralizing antibody against variola and vaccinia viruses, with a reproducibility equal to that of the standard focus reduction method on glass Petri dishes. Applications of this technique to the assay of field specimens and to the laboratory differentiation of variola viruses are discussed.

Antibodies, Viral↗
PubMed1972

Assay of neutralizing antibody against variola virus by the degree of focus reduction on HeLa cell cultures and its application to revaccination with smallpox vaccines of various potencies.

A method for assaying neutralizing antibody against variola virus was established by focus counting on HeLa cell cultures. The ND(50) titre, i.e., the serum dilution endpoint to give a 50% reduction in the number of foci, was determined with excellent reproducibility.Groups of students 19-20 years of age were revaccinated by the multiple pressure method with serial 10-fold dilutions of a smallpox vaccine and their neutralizing antibody response was assayed by the focus counting assay system and was related to the local skin reactions on the seventh day after inoculation and to the potency of the vaccine administered. There was a significant rise in the antibody level even after inoculation with a vaccine whose potency was as low as 1.3 x 10(5) pock-forming units/ml. In general, the rise in the log antibody level was proportional to the diameter of the reddening, but a significant rise was found among individuals who had no detectable skin reaction. The skin reaction was greater among individuals with a lower initial antibody level when the vaccine administered had a potency lower than 1.3 x 10(6) pock-forming units/ml.

Adult↗