COMPLEMENT FIXATION IN YAWS. 



487 



same result. These results demonstrated that serum from cases of yaws 

 does not bind complement when the extract from guinea pig's heart is 

 used. 



An extract of yaws papules was then prepared. One gram of papule was 

 added to 5 cubic centimeters of salt solution containing 0.5 peT cent carbolic 

 acid and placed in a shaking apparatus for twenty-four hours. This was then 

 centrifugated and the opalescent fluid decanted and placed on ice until ready to 

 be used. 



This extract was tested in the same way as the guinea pig's heart and was 

 found to be nonhemolytic and also noninhibitive. 



The extract in three dilutions, 0.4, 0.2 and 0.1, was added to the sera from the 

 cases of yaws (0.05 cubic centimeter) — 0.05 cubic centimeter of complement, and 

 allowed to remain one hour at room temperature; then 1 cubic centimeter of 

 washed ox-blood cells + 0.001 cubic centimeter amboceptor were added and all 

 incubated at 37° C. for two hours and then placed on ice for twenty-four hours 

 before the final reading was made. At the end of twenty-four hours it was found 

 that there was marked inhibition of hemolysis. 



The following table summarizes the results obtained with the two kinds 

 of extract: 





Y 





Guinea pig 



s heart 1 







extract. 



Dilution of extract ._ 



0.4 



0.2 



0.1 



0.4 



0.2 



0.1 





~r -r 

 + + + 



+ + 



+ +.+ 





+ + 

 + + + 



+ + + 



+ + + 

 + + + 













+ — haemolysis. 

 — = no haemolysis. 



These experiments are confirmatory of and supplementary to those 

 of Castellani already cited and furnish additional evidence of the non- 

 identity of syphilis and yaws. 



99323- 



