[Physicochemical and biological properties of the agents isolated from a patient with amyotrophic leukospongiosis and monkeys with experimentally reproduced disease].

The paper describes isolation from the brain of a patient who died of amyotrophic leukospongiosis (ALSP) and from squirrel monkeys with experimentally induced disease of heretofore unknown agents whose reproduction in continuous cell lines (HEp-2, CV-1, Vero) was accompanied by a significant increase in the mitotic activity of cells and adsorption of human 0(1) and M. rhesus erythrocytes. The blood sera from patients with ALSP and a monkey with experimental disease were found to contain a factor specifically inhibiting the hemadsorption phenomenon and the increase of the mitotic activity in the infected cell cultures. Investigations of the properties of the isolates showed them to have a buoyant density of 1.18 g/cm3 in a 20-60% sucrose gradient, to incorporate radioactive precursors of RNA and protein synthesis, and to be highly resistant to the effect of some physical and chemical factors. The data obtained suggest that the isolates differ from all the presently known conventional viruses but have some similarity with etiological agents of slow infections and may be classified as unconventional viruses.