Noguchi 's Modification 335 



same. Basset-Smith in 458 such cases found 94 per cent, 

 positive reactions. 



In latent syphilis Wassermann found 50 per cent, positive 

 reactions; Basset-Smith, 46 per cent. 



In chronic, presumably syphilitic, disease of the nervous 

 system, general paresis, and tabes dorsalis the positive reac- 

 tions vary. In the former disease some have found as high 

 as 90 per cent, positive; in the latter the usual figures vary 

 about 50 per cent. 



It is thus seen that the occurrence of the reaction is much 

 more conclusive evidence of the presence of syphilitic infection 

 than the failure of the reaction is of its absence. 



Treatment greatly influences the test. When under active 

 treatment, either with mercury and iodids or with salvarsan, 

 the reaction of the serums is usually negative. 



Nature of the Reaction. We now reach the point of con- 

 sidering the nature of the reaction. It is certainly not a vari- 

 ation of the Bordet-Gengou phenomenon. It does not occur 

 because of the presence in the blood of syphilitics of antibodies 

 which combine with the antigen and fix the complement. 

 It is probably not complement fixation so much as comple- 

 mentary inhibition, through the presence in the blood of 

 syphilitics of certain metabolic products, whose action inter- 

 feres with the complement in some entirely different manner. 



NOGUCHFS MODIFICATION OF THE WASSERMAMN 

 REACTION. 



Noguchi* has modified the Wassermann reaction, first by 

 employing as an antigen an extract of the heart of a normal 

 guinea-pig, and, second, by making use of human instead of 

 sheep corpuscles for the hemolytic test. The advantage 

 of the latter depends upon the fact, carefully determined by 

 Noguchi, that human blood-serum contains no amboceptors 

 active in effecting hemolysis of human blood-corpuscles, 

 though it not infrequently contains hemolytic amboceptors 

 for sheep corpuscles. In the directions for making the Was- 

 sermann test a control test for determining their presence or 

 absence was found expedient. It will also be remembered 

 that the presence of these amboceptors causes no invalidity 

 of the test, provided it be recognized. 



* "Serum Diagnosis of Syphilis," Philadelphia, 1910, J. B. Lippin- 

 cott Co. 



