GENERAL TECHNIC 



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tested with numerous different extracts at the same time, and under 

 similar conditions. A suitable alcoholic extract of syphilitic liver was 

 always included among the antigens in testing each serum or fluid, and 

 the other extracts compared with it in determining their antigenic value. 

 In the following table the results of such studies, covering a period 

 of two years, are given: 



TABLE 12. COMPARATIVE ANTIGENIC VALUES OF VARIOUS TISSUE 



EXTRACTS 



The results of these studies have shown : 



1. That cholesterinized alcoholic extracts of human, beef, and guinea- 

 pig heart are far more sensitive than simple alcoholic extracts of syphil- 

 itic liver. Another peculiar feature of these antigens is the fact that in 

 syphilis, if they react at all, they usually do so quite strongly. 



2. That the addition of cholesterin to crude alcoholic extracts of 

 syphilitic liver and of normal liver doubles their antigenic sensitiveness 

 without materially increasing their anticomplementary and hemolytic 

 action. 



3. We have practically never found a serum that reacted negatively 

 with a cholesterin extract and positively with an alcoholic extract of 

 syphilitic liver. On the other hand, in about 20 per cent, of cases the 

 cholesterinized antigens will react positively, whereas with the plain 

 antigen of syphilitic liver the reactions are negative. In the majority 

 of such instances the person was known to be luetic, but had received 

 treatment and was regarded clinically as cured, or the serum was that 

 of a long-standing and unrecognized case of lues. Unfortunately, slight 



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