Typhoid Agglutinins as Influenced by the Conditioned Reflex in Man

Abstract

In order to throw some light on the relation of the nervous system to the production of antibodies, an investigation of the artificial production of typhoid agglutinins in man was undertaken. Following the procedure which Metalnikov 1 used with animals, the plan followed in 3 experiments was to inject patients for 21 successive days with a small dose of typhoid vaccine subcutaneously, immediately after application of an ice cube to the cheek. After a rest period of approximately 2 weeks the patients were given the conditioning stimuli alone, that is, ice cube, and the prick of the needle. The curve of typhoid agglutinins was determined.

In the first experiment with 12 subjects, 6 received typhoid vaccine daily and 6 received injections of sterile saline. The latter served as a control group and did not show any titer during the injection period. Following the administration of conditioning stimuli alone to the first 6 subjects, 2 showed a slight rise in titer from 1-200 to 1-250.

In the second experiment 12 subjects received typhoid vaccine (groups of 4 receiving different dosages). Two weeks later the conditioning stimuli alone were applied. Blood was taken 75 minutes later. Of the 11 subjects so tested 6 showed a rise in titer of one tube (one dilution-step), one a rise of 2 tubes and one a rise in 3 tubes, in the usual dilutions of 1-20, 1-40, 1-80, 1-160, 1-320, etc. Three who had responded feebly to the vaccine showed no change. Twenty-four hours later the blood examination showed a marked decrease in titer in all subjects who had previously shown a rise. Subsequent conditioning stimuli again led to a rise.

In a third experiment, 16 subjects were given the same dosage of typhoid vaccine.