Facteurs pronostiques de la cétoacidose en réanimation des urgences

Abstract

Poliovirus obtained from mixedly infected HeLa cells (types 1 and 2) contains particles that are neutralizable by both type 1 and type 2 specific antisera. This alteration in phenotype is not transmitted to progeny virus and is believed to be due to phenotypic mixing. The progeny from most mixedly infected cells shows a high degree of phenotypic mixing (frequently 100%), and in some such cells there was no tangible evidence of the presence of one of the infecting genotypes. Mass yields from mixed infections produced the greatest proportion of phenotypic mixing in the first newly maturing virus.When HeLa cells are mixedly infected the amount of doubly neutralizable virus produced, the number of mixedly infected cells, and the number of cells producing phenotypically mixed virus all exceed theoretical expectations based on virus input by a factor of 2 to 14. Two factors are discussed which may contribute to this excess: one is the possible presence of HeLa cells which adsorb virus poorly or not at all and the second is a possible activating effect of plaque-forming on non-plaque-forming virus.