PRINCIPLES OF CHEMOTHERAPY 



851 



long before the disease has "worn itself out, "if, indeed, this ever occurs^ 

 in syphilis. 



The theory of chemoreceptors affords an explanation of this phe- 

 nomenon, just as the side-chain theory affords an explanation of the for- 

 mation of cellular antibodies and the processes of immunity. In adopt- 

 ing it we must be prepared to believe that the number of receptors and 

 the possibilities of their repair or modification are practically unlimited, 

 as evidenced by the large 

 number of substances capable 

 of exerting toxic action. Syph- 

 ilis, for example, is probably 

 a disease of great antiquity, 

 handed down from person to 

 person, from generation to gen- 

 eration, during which trans- 

 mission the receptors of the 

 spirochete must have under- 

 gone innumerable transforma- 

 tions and alterations, yet find- 

 ing suitable receptors in the 

 cells of practically all non- 

 syphilitic persons, although it 

 is now apparent that strains 

 have gradually been evolved 

 that possess receptors with 



marked affinity for certain tissues, as, for example, those for the central 

 nervous system, cardiovascular system, etc. 



Therapia Magna Sterilisans. As the development of resistant 

 strains is thus one of the possibilities and impediments to successful 

 specific therapy, whether with chemicals (chemotherapy) or with anti- 

 bodies (serum therapy), our efforts should be directed toward discover- 

 ing chemical substances and a method of administration that will com- 

 pletely sterilize the individual at one time (Ehrlich's therapia magna 

 sterilisans). This possibility has been amply demonstrated experi- 

 mentally by Ehrlich, and it has occasionally been accomplished in the 

 early stages of human syphilis by means of salvarsan administered early 

 in the proper manner and in correct dosage, but, unfortunately, it is 

 not true of the majority of cases, the difficulties increasing with the 

 duration of the infection. Fortunately, the investigations of Margulies 

 1 "Die Behandlung der Syphilis" (Konigsberg Versammlung), Leipzig, 1910, 930. 



FIG. 144. BLOOD OF A RAT INFECTED WITH 



SPIROCH^TA RECTTRRENTIS. 



(Drawing made from dark-field illumination 



just before administration of salvarsan.) 



