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Biomedical subjects

D T KARZON

Publications and source records attributed to D T KARZON.

At least 37 records · Page 2Linked to original sources
PubMed1959

Cytopathic effect of canine distemper virus in tissue culture.

A characteristic cytopathic effect was obtained with canine distemper virus (Onderstepoort strain) propagated in chick embryo fibroblast monolayer tissue culture. In limiting dilutions the lesions were focal. The titer at the 20th tissue culture passage was approximately 10(5) TCD(50)/ml. Cytopathogenicity was specifically inhibited by distemper immune serum. Minute plaques were produced under agar overlay.

Animals↗
PubMed1951

The pathogenesis of infection with a virulent (CG 179) and an avirulent (B) strain of Newcastle disease virus in the chicken. I. Comparative rates of viral multiplication.

The comparative growth rates of a virulent (CG 179) and an avirulent (B) strain of NDV in the chicken were analyzed. Following intramuscular inoculation, the CG 179 and B strains both increased at the same rate in the extraneural tissues, i.e. the blood, lung, rectum, and spleen, but the CG 179 strain showed an accelerated growth rate in the brain. The CG 179 strain also multiplied more rapidly in the brain than the B strain following intracerebral administration of minimal inocula. Recovery with the B strain was associated with a decline in virus titer, first in the circulating blood, then in the visceral organs, and lastly in the central nervous system. Certain neuropathological observations were correlated with the pattern of virus growth.

Animals↗
PubMed1951

The pathogenesis of infection with a virulent (CG 179) and an avirulent (B) strain of Newcastle disease virus in the chicken. II. Development of antibody.

Circulating antibody appeared in the convalescing NDV-infected chicken concomitantly with the disappearance of virus from the tissues. The antigenic response to the CG 179 and B strains was demonstrated to be approximately equal. The neutralization test in the embryo and the hemagglutination inhibition technique yielded parallel results in the measurement of antibody early in convalescence, but late in convalescence the hemagglutination inhibition titers were relatively lower. This disparity indicates the possible duality of the antibodies. There was a wide ratio between the neutralizing antibody titers found in the brain and in the serum after an asymptomatic infection with NDV. The antibody level in the brain appeared to be related to the extent of virus growth and damage in the central nervous system. It appeared likely that a major factor in determining the virulence of the CG 179 strain was the more rapid attainment in the central nervous system of high virus concentration which outstripped the defense mechanisms of the host.

Animals↗