Poliomyelitis Virus. Results of Treating with Certain Chemicals and with Heat. ∗

Abstract

Vinson and Petre 1 demonstrated that the virus causing mosaic disease of tobacco was “in many ways analogous to that of a chemical substance/' since it could be precipitated by certain dyes and chemicals without loss of virulence and could be recovered uninjured after removal of the phosphates, sulphates, pigments and most of the protein contained in the plant juice. It was thought of interest to apply certain of their methods to the virus of poliomyelitis, although the one virus was of plant and the other of animal origin. Certain modifications in technique were necessary, however. Strict asepsis had to be practiced while care had to be taken in neutralizing the end product and in pulverizing any precipitate before inoculation. The necessity of intercranial injection into monkeys required particular attention as to the amount, the character and the toxicity of the substance given.

A Berkefeld V filtrate of a 10% saline suspension of monkey poliomyelitis virus was employed. Definite proportions of the chemicals were added to a standard amount of this filtrate, usually SO cc. Whenever a precipitate was used, it was repeatedly washed with saline, ground in a sterile mortar with a definite amount of saline and then filtered through sterile gauze before intercranial inoculation. If a supernatant fluid was given the reaction was adjusted to pH 7.0. A control monkey injected with the virus filtrate was always added to each experimental series. Tests for proteins, carbohydrates and occasionally for lipoids were made whenever sufficient material was available. Daily observations, including rectal temperatures were taken on each monkey for 2 to 3 weeks unless the animal developed typical poliomyelitis after the usual incubation of 5-7 days. Histological sections of the cord and brain were examined from all animals succumbing to the disease.