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Biomedical subjects

M M SIGEL

Publications and source records attributed to M M SIGEL.

53 records · Page 3Linked to original sources
PubMed1952

Studies on the psittacosis-lymphogranuloma group. II. A non-infectious phase in virus development following adsorption to host tissue.

The pattern of growth of meningopneumonitis virus in vitro seemed to be similar to that occurring in ovo and thus the initial stages of development, the adsorption and the latent periods, were investigated by the use of tissue culture procedures. The initial increment of infectivity in allantoic membrane suspensions following virus inoculation in ovo was due to prolonged adsorption of virus and not to immediate virus reproduction. The length of the adsorption period varied with the virus dilution employed. The reduction of virus titer in allantoic membrane suspensions subsequent to adsorption was due to a change of infectious virus to a non-infectious form and this seemed to be a part of the normal developmental cycle of the virus. The possible causes for both prolonged virus adsorption and for the subsequent development of a non-infectious form are discussed.

Adsorption↗
PubMed1951

Studies on the psittacosis-lymphogranuloma group. 1. The pattern of multiplication of meningopneumonitis virus in the allantois of the chick embryo.

Because of the peculiar properties of the psittacosis-lymphogranuloma group of viruses, the pattern of multiplication in the allantois of the chick embryo of one of their number, meningopneumonitis virus, was studied. This was done by determination of the changes in its infectivity for mice and chick embryos. Titration of infectivity in embryos proved to be a more sensitive procedure than titration in mice; the latter procedure however, had the advantage of greater simplicity and gave more clear-cut results. The mouse titration method was used in most of the experiments. Following inoculation of virus into the allantois, there was a slow decrease in infectivity in the allantoic fluids followed by an increase due to appearance of new virus between 24 and 48 hours. The slope of declining infectivity in the allantoic fluids in ovo was similar if not identical with the slope of decreasing infectivity in allantoic fluids in vitro caused by thermal degradation of virus. Multiplication of the virus in allantoic membranes was characterized by the following pattern: (a) Increase in infectivity in the first few hours (exact duration of increase depended on concentration of virus in inoculum) due to adsorption of virus. (b) Decrease in infectivity up to about 20 to 24 hours. (c) Increase in infectivity due to appearance of the new generation of virus. The growth curve of meningopneumonitis is analyzed and the pattern of growth is discussed in the light of the present concepts of viral multiplication.

Allantois↗