I 9 4 PRACTICAL METHODS IN IMMUNITY 



to the second injection should be considered as possible subjects for anaphylactic 

 shock. 



Vaughan recommends that when this is to be feared one should only give about 

 o.i c.c. of the serum and after an interval of two hours, provided no untoward 

 symptoms set in, to give the full amount of the injection. Besredka advises heating 

 the serum to 56C. as a guard against anaphylactic shock. 



Allergy. The condition of hypersusceptibility or anaphylaxis is at 

 times termed allergy. Thus in a person who has been successfully 

 vaccinated a reaction shows at the site of inoculation within twenty- 

 four hours which does not appear in the nonimmune person for a period 

 two or three times as long. The diagnostic tests with tuberculin and 

 luetin are hence often referred to as allergic reactions. 



Toxic Protein Split Products. It may here be stated that some in- 

 vestigators are of the opinion that our views not only as to immunity 

 but as to the essential nature of infectious diseases may be later on 

 found to rest in production of anaphylaxis. According to Vaughan 

 and others the parenteral introduction (hypodermic as opposed to 

 alimentary tract or enteral introduction) of foreign proteids excites the 

 formation of specific ferments in the cells and fluids of the animal 

 injected. After the ferment is formed a second injection of the same 

 proteid activates the ferment which splits up the proteid into a poison- 

 ous and nonpoisonous portion, the former causing the symptoms of 

 anaphylaxis or disease in the case of the poisonous split proteid of 

 bacterial pathogens. 



The name anaphylactine has been applied to the sensitizing substance 

 produced during the period of incubation, and anaphylatoxin to the 

 poisonous part of the split proteid. 



It has been proposed to employ this phenomenon as a diagnostic measure. By 

 taking the serum of a tuberculous patient, which would contain the sensitizing sub- 

 stance, and injecting it into the peritoneal cavity of a rabbit, the animal would be 

 sensitized and an injection of tuberculin a few hours later would bring about the 

 phenomena of anaphylaxis in the rabbit. 



This passive anaphylaxis, as it is termed, usually requires approximately twenty- 

 four hours for sensitization. This passive anaphylactic sensitization seems to dis- 

 appear in two weeks. It has been advised to passively sensitize guinea-pigs with 

 the serum of the person about to be injected and then twenty-four hours after inject 

 the guinea-pigs with the curative serum. If untoward results occur in the guinea- 

 pigs the patient should not receive the injection. 



Recently Hagemann has found the following technic valuable in the diagnosis 

 of surgical tuberculosis. Guinea-pigs are inoculated intraperitoneally with tuber- 

 culosis cultures and by the end of the second week such pigs are sensitized. The 

 suspected material, as serous effusion, is injected intracutaneously and within twenty- 

 four to forty-eight hours a distinct swelling of the skin with a bluish-red center, 



