546 ANAPHYLAXIS 



toms, which may terminate in death. This interesting and plausible 

 theory will be referred to again. It has received further experimental 

 support from the work of White and Avery 1 with split edestin and 

 split tubercle-cell substance; 2 and from that of Zunz 3 and Wells and 

 Osborne, 4 the last-named observers working with vegetable proteins, 

 and concluding that although it is probable that the entire protein molecule 

 is involved in the anaphylactic reaction, only certain groups are specifically 

 concerned in the process. In other words, it would appear that anaphy- 

 laxis, for example, serum anaphylaxis is not due to one protein sub- 

 stance in the serum that sensitizes and another that intoxicates, both 

 properties residing in the same protein molecule. Whether they are the 

 same intramolecular substances existing side by side, one the sensitizer 

 and the other the intoxicator, as is believed by Vaughan, cannot be 

 definitely decided, although experimental work would tend to indicate 

 that the latter may be the true explanation. 



Physical State of Anaphylactogens. The results of experiments 

 all tend to support the theory that proteins in solution are most power- 

 ful in producing anaphylaxis, because they are able to come into intimate 

 contact with body-cells, and cell permeation is probably necessary for 

 the most complete sensitization. This explains in part the conflicting 

 statements concerning the effect of heat on the sensitizing properties of 

 blood-serum. Rosenau and Anderson found that animals could not be 

 sensitized with serum that has been heated at 100 C., whereas Doerr 

 and Russ placed the point at 80 C. Besredka showed that the sensitizing 

 properties are in part at least, dependent upon the physical condition of 

 the protein, and that heating undiluted blood-serum coagulates the pro- 

 tein and leads to a decrease of its anaphylactogenic properties. Similarly, 

 Vaughan found that proteins that were insoluble in water, as, for ex- 

 ample, edestin, sensitize more readily when dissolved in salt solution. 

 The same factors are operative with the protein used for intoxication, 

 the physical state of the protein substance having a direct bearing 

 on the rapidity with which shock is produced. Temperatures high 

 enough to disrupt and destroy proteins are, however, equally destructive 

 to their sensitizing properties. 



An interesting question in this connection is whether sensitization 

 and intoxication may occur with the parenteral introduction of protein 

 as with the food. In the great majority of instances the gastro-in- 

 testinal enzymes so completely disrupt the protein molecule that sen- 



1 Jour. Inf. Dis., 1913, xiii, 103. 2 Jour. Med. Res., 1912, xxvi, 317. 



3 Zeitschr. f . Immunitatsf ., 1913, xvi, 580. 4 Jour. Inf. Dis., 1913, xii, 341. 



