126 LOCAL ILSSUE REACTIVITY 



j)i()j)c'rly. riic iiimil)cT ol liorsc and guinea piti, sera tested Avas 

 too small to allo\v any statistical conclusions. 



The ^vork reported liius far has dealt with the reactivation ol 

 neutralized reactino- factors of the meningococcus. In further 

 experiments it was foiuid, liowever, that the reactivating property 

 was non-specific inasmtich as the same sera ^vere capable of re- 

 acti\ating neutralized reacting factors of B. culi as well. 



It has been noticed in the cotnse of tlie work that the reac- 

 tivating property may disappear on storage. The observations sug- 

 gested, therefore, studies on the relation of the reactivating prop- 

 erty to the complement and also on their lieat resistance. It was 

 found, liowever, that the reactivating factors had no apparent 

 relationship to the complement content. Some guinea pig sera 

 containing active complement were devoid of reactivating factors 

 ^v^hilst rabbit sera containing no complement possessed the reac- 

 tivating factors to a marked degree. The reactivating factors, how- 

 ever, were found heat-labile, the exposure to 56° c. for five min- 

 utes, 50° c. for t^venty-five miniues and ^',7° c. for four hours 

 being sufficient to destroy them. 



Taking advantage of the above observations it ^vas planned to 

 determine ^vhether immime sera contained native reactixating 

 ]:)roperty, and if so, xvhether heating to a temperatiue destructive 

 to the reactivating ])ro]:)erty but ineffective against neiUralizing 

 antibodies woiUd raise the neutralizing potency of these sera. 



Various immime sera, unheated and heated in the xvater bath 

 at 37° c. for four hotns (temperature sufficient for destruction 

 of reactivating factors) Avere titrated for ireutralizing antibodies 

 in the usual nranner. The anti-meningococcus sera xvere tested 

 \vith and without the auxiliary antibody. The anti-typhoid horse 

 sera Avere tested xvithout auxiliary antibody. 



The treatment enabled two batches of anti-meningococcus 

 horse sera to neutralize com])letely 50 and 80 tuiits ol menin- 

 gococcus reacting factors, respectively. In contrast, only irregular 

 neutralization xvas obtained xvith the same tuiheated sera xvithout 

 the aid of the auxiliary antibody, and only 20 iniits were com- 

 j^Ietely neiUralized exen xvith the aid of the auxiliary antibody. 

 The heated anti-typhoid horse serimi shoxved a Go per cent in- 

 crease in the titer (tuiheated 375 units in 0.25 c.c, heated ()oo 

 units in 0.25 c.c.) . 



Incidentally, in the course of some xvork on antibody absorp- 

 tions, Klein tested in this laboratory for control pin poses the 



