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Biomedical subjects

F L HORSFALL

Publications and source records attributed to F L HORSFALL.

65 records · Page 4Linked to original sources
PubMed1950

Persistent antigenic variation of influenza A viruses after incomplete neutralization in ovo with heterologous immune serum.

Antigenic variants of influenza A virus strains emerge on serial passage in ovo in the presence of immune serum against different but related strains. An old laboratory strain (PR8) which had been through hundreds of animal passages was as readily modified by this procedure as recently recovered strains. Such variants apparently can be obtained at will and show antigenic patterns which are reproducible and appear to be predictable in terms of the immune serum used for their selection. Variant strains retain their new antigenic patterns on serial passage in ovo in the absence of immune serum. Limited serial passage in ovo of strains in the absence of immune serum did not result in the emergence of antigenic variants. Similarly, serial passages of strains in ovo in the presence of immune serum against widely different strains, which failed to show significant cross-neutralization, did not lead to the appearance of antigenic variants.

Antigenic Variation↗
PubMed1950

Further studies on the associative reactions of pneumonia virus of mice and influenza viruses; combination with various animal tissues and adsorbents.

Tissue particles from a wide variety of animal tissues possess the capacity to combine with PVM. Various adsorbents also combine with the virus. Elution of PVM from combination with either tissue particles or adsorbents can be achieved by appropriately altering the ionic environment. Influenza viruses also are adsorbed on and eluted from adsorbents under similar conditions. Reasons are presented for thinking that combination of PVM with tissue particles results from the action of adsorptive forces between virus and tissue particles.

Animals↗
PubMed1950

Lack of identity in neutralizing and hemagglutination-inhibiting antibodies against influenza viruses.

There is an exponential linear relationship between the quantity of influenza virus neutralized and the quantity of immune serum employed in in ovo neutralization. The slope of the neutralization line is extremely steep. The concentration of neutralizing antibody can be measured with considerable precision in ovo if the constant virus-varying serum technique is utilized. The amounts of hemagglutination-inhibiting and neutralizing antibodies which are absorbed by a given quantity of influenza virus (PR8) were found to be predictable and the degree of reactivity of these two antibodies was shown to be directly related to the extent of immunization. It was demonstrated that there are marked discrepancies in correlation between antibody titers obtained by in vitro hemagglutination-inhibition and in vivo neutralization techniques and that neutralizing antibody is preferentially absorbed by a given quantity of virus. Inasmuch as the results were found not to be attributable to peculiarities of the techniques employed, it appears that the antibodies measured by hemagglutination-inhibition in vitro and by neutralization in vivo are not identical.

Antibodies↗