PROTEIN SENSITIZATION OR ANAPHYLAXIS 243 



state to egg-white after about one year, and after this 

 time they can be resensitized. The same investigators 

 found that guinea-pigs sensitized to colon or typhoid 

 proteins begin to lose their sensitization after thirty 

 days. Pirquet and Shick report the continuance of the 

 sensitized state in man after treatment with diphtheria 

 antitoxin up to more than seven years, and Currie 1 up to 

 five years. 



The Reinjection. This term has come to have in this 

 connection a restricted and definite meaning. Repeated 

 injections may be employed in inducing anaphylaxis, but 

 by "reinjection" we mean the one made after the anaphyl- 

 actic state has been established. While subcutaneous, 

 intra-abdominal, and intravenous methods of adminis- 

 tration are alike suitable and effective in inducing anaphyl- 

 axis, the intravenous reinjection is much the most effective. 

 Besredka has been partial to the intracerebral introduction 

 of the "reinjection," and he claims that it has advantages 

 over the intravenous, although the latter is the most effec- 

 tive. With a set of highly sensitized guinea-pigs and with 

 the same serum he obtained the following comparative 

 results with the different methods of administration: Fatal 

 dose, intravenously, -j^ to ^V c - c -j intracranially, YQ- to -g-; 

 intraperitoneally, only about one-half the animals responded 

 to 5 c.c., and subcutaneously this amount had scarcely any 

 effect. Besredka prefers intracranial injections because 

 they are not so delicate as the intravenous, and more easily 

 measured. In conjunction with Steinhardt 2 he has developed 

 a method of standardizing sera. He has found that sera 

 differ widely in toxicity, as tested on sensitized guinea-pigs 

 by intracerebral injections, the fatal dose varying from ^ 

 c.c. in a sample thirteen years old, to T ^-- c.c. in some fresh 

 samples. This variation is in part due to age and in part 

 to the horses from which they are taken. His studies on 

 the effects of age on the toxicity of sera as tested upon 



1 Jour, of Hygiene, viii. 35. 



2 Ann. d. 1'Institut Pasteur, 1907, 157. 



