BACTERIAL ANAPHYLAXIS 



orthosilicate). 33 They therefore substituted these insoluble sub- 

 stances for antigen, allowed them to absorb serum constituents, as- 

 sumed by them to be amboceptor, out of normal and inactivated im- 

 mune sera, and then allowed complement or alexin to act upon the 

 "sensitized" kaolin. 



In this way they obtained active and powerful anaphylatoxin, 

 and claim, in consequence, that the matrix of the poison is not in 

 the bacterial antigen, but in the sensitizer or amboceptor, which is 

 mechanically absorbed by the bacteria (as by the kaolin), and thus 

 made amenable to the alexin action. 



The experiments of Keysser and Wassermann have found con- 

 firmation in the hands of other investigators, although the results of 

 ^Xeufeld and Dold, as well as our own, with this method were far 

 more irregular than were those of Keysser and Wassermann. Neu- 

 feld and Dold 34 and Friedberger 35 suggest that the horse serum ab- 

 sorbed by the kaolin may act as an antigen itself, and is acted upon 

 by normal sensitizer present in the guinea pig serum. This is in 

 keeping with the well-known fact that small amounts of sensitizers to 

 many varieties of foreign proteins are present in normal serum, and 

 is further borne out by the fact that Neufeld and Dold, unlike Keys- 

 ser and Wassermann, were never able to produce anaphylatoxin by 

 allowing the alexin alone to act upon kaolin without previous ab- 

 sorption of horse serum. 



We say "never," though the protocols of Neufeld and Dold 36 

 show a single successful experiment. This they explain, however, by 

 assuming the accidental presence of some antigen in the alexic 

 serum. That is, the entire complex, antigen, sensitizer, and alexin, 

 is assumed to have been present in this particular guinea pig serum. 

 The same explanation may be applied to the occasional inherent 

 toxicity which develops in normal guinea pig sera on standing. 

 Whether the above complicated explanation is necessary or whether 

 we may assume an autolytic process in the guinea pig serum by which 

 anaphylatoxin-like substances are formed is an open question. 



At any rate, it has been shown that, even with bacteria, the 

 action of alexin is not the only way in which acute poisons may be 

 obtained from them. And, indeed, if we look upon the action of 

 alexin as analogous to that of an enzyme an assumption for 

 which we have much supporting evidence, we may well expect 

 that other methods of proteolysis will give similar toxic cleavage 

 products. And various methods of bacterial autolysis have ac- 



33 Kaolin emulsions will absorb amboceptor only out of diluted serum. 

 Out of concentrated serum complement is completely absorbed. Friedberger 

 u. Salecker, Zeitschr. f. Immunitatsforsch., Vol. 11, 1911; Zinsser, from 

 Journ. Exp. Med., Vol. 18, 1913. 



34 Neuf eld and Dold. Loc. cit. 



35 Friedberger and Salecker. Zeitschr. f. Imm., Vol. 11, 1911. 



36 Dold. LOG. cit. 



