The successful cultivation of poliomyelitis virus in suspensions of cells from various tissues or organs, such as skin, muscle, intestine, kidney, or testis, has been taken as proof that the virus is not necessarily neurocytotropic in the intact animal body. This conclusion is challenged by Faber1 of Stanford University, based on technical errors in the in vitro cultivation technique.
The cells have always been repeatedly washed in saline solution, so that all normal inhibiting serum components are removed and so that many intracellular inhibiting factors are removed or denatured. The added nutrient medium has always been ox serum ultrafiltrate, which is free from normal inhibiting colloids.
There is abundant evidence that neurocytotropism and axonal conduction of the virus takes place in the intact animal. Clinical evidence does not support the belief that other tissues are capable of supporting the virus, since dermatitis, enteritis, nephritis, and orchitis are not clinical