2S8 Imnmnity in Some of its Biochemical Aspects [Jan. 



Significance of the pcriod of inciibation in anaphylaxis. An in- 

 teresting result of these studies on anaphylaxis is the light they shed 

 on the significance of the period of incubation, and also on the poi- 

 sonous Symptoms produced by bacteria f rom which no very poisonous 

 siibstance can be extracted. Taking up first the latter point : It has 

 been held that the various pathogenic bacteria, like the diphtheria 

 and tetanus bacilli, either secrete toxins or, at least, contain such 

 toxins bound np in their protoplasm. In the latter case, it was 

 believed that these endotoxins, as they were termed, were set free 

 during the destruction of bacteria in the body. From his studies 

 on anaphylaxis, Friedberger concludes that it is entirely unneces- 

 sary to assume the existence of specific endotoxins in bacteria to 

 account for the various Symptoms seen in bacterial infections. By 

 repeatedly injecting sensitized animals with minute doses of sheep or 

 horse serum, he found it possible to produce all manner of fever 

 curves at will, merely by varying the size of the dose and the inter- 

 val between the injections. From this he concludes that the diver- 

 sity of clinical Symptoms of various infectious diseases can readily 

 be explained, even on the assumption of but a single poison. He 

 speaks of this as anaphylatoxin, and regards it as a cleavage product 

 of protein of whatever origin introduced parenterally. Just as in 

 enteral digestion, uniform cleavage products are formed from most 

 diverse proteins, so, he believes, that in the parenteral protein de- 

 composition leading to the formation of anaphylatoxin, a certain 

 poison is uniformly produced. Whether or not, in addition to 

 anaphylatoxin, there are other specific poisons for the various in- 

 fectious diseases is immaterial; their existence (except in certain 

 diseases) has not been proved, and the assumption of their existence 

 is unnecessary. According to Friedberger, the assumption of a 

 common anaphylatoxin is only apparently in contradiction to the 

 well known law of specificity of infectious diseases. In the infec- 

 tious diseases it is not the poison which is specific, but only the mode 

 of its production. The production of anaphylatoxin requires the 

 action of antibodies; the mere Solution or disintegration of bacteria 

 by other means does not suffice. In other words, a particular 

 cleavage of the protein molecule is necessary. 



Bearing of the period of incubation on intoxication by bacterial 



