No abstract

No abstract

IN I903, Meyer and Ransom' reported some experiments upon cats and rabbits in which large and rapidly fatal doses of tetanus toxin were injected into the substance of the lumbar segment of the nontransected spinal cord. These and other experiments2 of Meyer's were carefully repeated upon dogs, in I935, by Firor and Jonas.3 They were able to show, as Zupnik4 had suggested in 1902, that spinal injections of toxin can produce tactile reflex motor tetanus without inducing any sign of the muscular rigidity which complicated Meyer's experiments and fortified his belief that both the muscular rigidity and the reflex convulsions of tetanus were of solely central origin. In repeating Meyer's experiments the amount of toxin injected into any one dog's lumbar cord (a nonvital center) was very much smaller (I/4 to I/I50) than the amount required to kill the animal had the toxin been injected intravenously, subcutaneously, or intramuscularly. And yet in each of the ii experiments the dog died within a week. It was this unexpected and early death which first gave rise to the suspicion that tetanus toxin may be altered when in conltact with the cells of the spinal cord.In an attempt to confirm our suspicions, we carried out the experiments described in a paper published in I938, entitled "The Apparent Alteration of Tetanus Toxin Within the Spinal Cord of Dogs."5 We related there the facts which led us to entertain the possibility of such alteration. In order to establish without any doubt the pattern of reaction for each experiment reported in that paper, we have enlarged our series in each category. The present paper tabulates these experimental results to date. We were also anxious to find more definite proof, or disproof, of the apparent alteration of the toxin. Our further attempts, together with some related experiments, occupy the latter part of this communication.To avoid too much repetition we have omitted from this paper the complete descriptions of Methods of Procedure and the Protocols of Typical Experiments that appeared in our earlier paper; and in an effort to clarify the discussion we have altered somewhat the order in which the various experiments were presented in the previous paper. However, to facilitate reference to the more detailed descriptions of procedures, we have indicated in parentheses under each experiment in the present paper the corresponding sections of our earlier paper.Notes on Dosage, Toxins, Abbreviations Used in the Tables, Symptoms, etc.-Although in keeping our records and in calculating our doses our standard unit was the guinea-pig median lethal dose (or LD50), we have in this paper expressed our doses as * These studies were made possible by a grant from The John and Mary R. MarkleFoundation.

No abstract

No abstract