Chapter XIII 



APPLICATION OF THE PHENOMENON OF 



LOCAL SKIN REACTIVITY TO TREATMENT 



OF CERTAIN HUMAN CONDITIONS 



INTRODUCTION 



THE foregoing studies, having established the close relation- 

 ship of the active principles of the phenomenon to bacterial 

 exotoxins, and having indicated a possible important role 

 that they may play in the evolution of spontaneotis infectiotis dis- 

 eases, it is readily luiderstood why work \vas undertaken to deter- 

 mine to ^vhat extent the phenomenon of local skin reactivity could 

 be titilized for practical serum therapy. Attempts of this sort 

 seemed to be the more desirable since they allowed a new ap- 

 proach to the serum therapy of diseases in ^vhich the de\elopment 

 has been greatly handicapped by the lack of appropriate methods 

 for demonstration of toxins and antitoxins. It is indeed well 

 kno^vn from the past experiences of many years that in passi^'e and 

 active protection against infectious diseases antitoxins are infinitely 

 superior to any other antibodies thus far discovered. Among the 

 latter, agglutinins, precipitins, complement fixing antibodies and 

 bactericidins, although serving the purpose of classification of 

 bacteria and being valtiable in diagnosis of diseases, play no im- 

 portant role in passive protection of the host against an infectious 

 disease. 



Antibodies capable of protection of laboratory animals against 

 virulent microorganisms, ho-^vever, attracted considerable atten- 

 tion from investigators. It still remains questionable whether the 

 protective potency of a sertnn can be justifiably used for estima- 

 tion of its therapetitic value. 



\'irulence represents the power of a microorganism to invade 

 and propagate in the host, the production of injiny being a 

 weapon employed by the microorganism incidentally to its in\a- 

 sion of the host. It is ^vell known that the po^ver of invasion of 

 the host does not necessarily parallel the ability to produce in- 

 jury. The virulence and toxicity may be independent functions 



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