58 IMMUNO-CATALYSIS 



duration or entirely absent. These patients either had very mild serum 

 disease lasting from one to five days or had none at all. One individual 

 who had received 630 ml. oF horse serum showed the persistence of 

 horse serum in the circulation for 75 days. He also showed precipitins 

 and had severe serum disease lasting 12 days. These observations were 

 made, in the main, by the use of macroscopic precipitin tests, and there- 

 fore are rough estimations. By the use of refined quantitative micro- 

 technique one may be able to detect circulating antigens during a 

 longer period of time. Such estimations, however, would fail to inform 

 us about the amount and the duration of antigens bound in the tissues 

 which may continue to exercise antigenic stimuli during a far greater 

 period of time than are indicated by the tests for their presence in 

 blood and urine. 



Herdegen, Halbert and Mudd (1947) developed an in vivo tech- 

 nique whereby they demonstrated that 0.002 mg. of Shigella para- 

 dysenteriae Type III antigen was capable of inducing an agglutinin 

 response. This method was used to determine the fate of this antigen in 

 mineral oil emulsion stabilized with lanolin derivatives at the site of 

 subcutaneous inoculation in mice. It was found that the antigen per- 

 sisted at the site of injection for at least 24 weeks when 200 i^g. of 

 antigen were injected. This was demonstrated by covering the injected 

 vaccine from period to period; 200 /tg. of antigen per 0.3 ml. of original 

 volume of vaccine was recovered after a period of two weeks. This de- 

 creased to 20 fj-g. after 12 weeks, but 0.2 //.g. was still present at 24 

 weeks. The material recovered from the injection site was still anti- 

 genic. The deterioration of antigen at the site of inoculation was 

 paralleled by a fall in the agglutinin titers of the mice receiving the oil 

 vaccine. 



In connection with the above observations, a reference to the find- 

 ings of Freund and Bonato (1946) is of interest. Using water-in-oil 

 emulsion stabilized by Falba (a mixture of oxycholesterine and choles- 

 terine derived from lanolin) of killed typhoid bacilli as vaccine, they 

 reported the presence of antibodies in the sera of animals three years 

 and one month after one injection and three years and five months 

 after two simultaneous subcutaneous injections. 



The persistence of pneumococcal polysaccharide in the circulation 

 for a long period of time has been reported by various investigators. 

 Dochez and Avery (1917) carried out a systematic study of the pres- 



