REACTIVITY OF MALIGNANT NEOPLASMS 2^7 



ser\ed niicroscopically, an area of tumor infiltrated Avith Ijloocl. 

 The bleeding seemed to occur in sites of spontaneous necrosis. 

 The reaction reached its peak from six to twelve hours following 

 the injection. Incidental to the hemorrhage, there was an extreme 

 dilatation of blood vessels. The author was strongly impressed by 

 the histological similarity of the phenomenon of local skin reac- 

 tivity and the appearance of the reaction in the tiunor follo'wing 

 a single intra\enous injection of the bacterial filtrate. In addition 

 to the actual sexere hemorrhage, he foinid climips of agglutinated 

 platelets in the lumina of the blood vessels. The accompanying 

 inlhnnmation obserxed in the reaction of the phenomenon in the 

 rabbit cotdd alsc:) ])e obserxed in the timior reactic^n, although to 

 a lesser degree. The edema seemed to compress the timior cells. 

 The changes observed, however, did not fully explain the rapid 

 regression of the timior xvhich may occur either following the 

 hemorrhage and edema, or appear later at the periphery of 

 healthy grooving tissue se\eral days after the elicitation of the 

 reaction. Apparently there was an injinious effect upon the tumor 

 cells as well. 



Apitz reports that clear-cut experiments xvere obtained xvh.en 

 B. coli "agar washings" filtrates were used, notably, those capable 

 of eliciting the phenomenon of local skin reactivity in the rabbit. 

 Agar gave irregidar residts in some of the mice tested. Because 

 of the fact previously reported loy me that mixtures of animal 

 protein antigens xvith homologous antibodies are highly potent 

 in elicitation of the phenomenon of local skin reactivity in rab- 

 bits prepared with bacterial filtrates, the aiuhor treated some of 

 his mice with a mixtine of horse seriun and rabbit anti-horse 

 serum. The intravenous injection of the mixtine produced hemor- 

 rhage in tumors xvith greater irregularity than the injections of 

 agar. An anti-mouse guinea pig serum also produced hemorrhages 

 in the tumor but they xvere not nearly as pronounced as xvith the 

 bacterial filtrates. The injections were generally toxic to the mice. 

 The fatal outcome of the experiments did not guarantee, ho\v- 

 ever, a positive reaction in the tumor. The effect of the anti- 

 mouse serum may be also considered as depending on the react- 

 ing potency of an antigen-antibody complex, i.e., the anti-mouse 

 antibody plus the mouse circulating blood as an antigen. 



Of considerable interest are the experiments of \arious authors 

 tending to show that the reaction in the tumor described here 

 depends on the presence of active principles of the phenomenon 



