Occurrence of Poliocidal Substances in Tears,Saliva and Cerebrospinal Fluid of Normal Individuals. ∗

Abstract

While the presence of poliocidal substances in the serum of normal individuals is generally known and this fact is tentatively put in correlation with the mechanism of resistance to the disease, there are but few data to indicate the extent of distribution of similar substances in other body fluids and secretions of man. Apart from the early work of Amoss and Taylor, 1 who reported neutralization of poliomyelitis virus by the nasal secretions of healthy persons and more recent observations on the inactivation of the virus by pregnancy urine, placenta extracts and various endocrine preparations, 2 , 3 investigations in this field have been strangely neglected. Yet it is clear that the question whether or not virucidal substances may normally be found at the site of the presumable portal of every or in the vicinity of the ultimate seat of the lesions, carries far greater significance than the successful demonstration of such substances in the circulating blood. In an attempt to bridge this gap in our knowledge, we have conducted a series of experiments in order to determine whether poliocidal substances are present in the tears, the saliva and the cerebrospinal fluid of normal adults.

Virucidal tests with normal human tears. Human tears were collected on the day of the experiment from a group of 5 or 6 adult persons after local irritation of the conjunctiva by mustard oil or onion juice. The individual specimens were combined and neutralization tests carried out with the pooled mixtures. The mixtures were used undiluted and in dilutions ranging from 1:2 to 1:20. Amounts of 0.8 cc. were combined with 0.2 cc. of a 10% suspension of poliomyelitis virus. After incubation of 1 1/2 hours at 37°C., the tears-virus mixtures were allowed to stand in the ice-box for 24 hours and then injected intracerebrally into individual monkeys. A total of 11 tests were carried out, 2 with undiluted tears, 4 with tears diluted 1:2, 4 with tears diluted 1:5 and 1 with tears diluted 1:20.