The Effect of Concentration and of Various Tissue Constituents on the Virulence of the Poliomyelitis Virus

[摘要] 1. 1. Titration of poliomyelitis virus cord suspensions of varying percentages shows there is a particular concentration with maximum virulence below which the dilutions become progressively less infective and above which virulence is likewise diminished.2. 2. Berkefeld-filtrates of virus cord suspensions are at times more virulent than corresponding unfiltered suspensions, although exceptions do occur.3. 3. Neither normal monkey cord nor normal monkey brain when added in vitro to virus filtrates, has any appreciable effect on the virulence of the virus. The results with convalescent cord are too irregular to indicate clearly the presence of a neutralizing principle in the immune tissue.4. 4. Normal monkey testicle added to virus filtrates in vitro frequently produces a conspicuous diminution of virulence of the virus in the supernatant fluid. The extent of this antagonistic effect varies with different monkey testicles. Normal rabbit testicle, under similar conditions, seems slightly to enhance the virulence of the virus.

[学科分类] 生物科学（综合）