HUNTOON AND HUTCHISON 933 



of Rosenow's serum depends upon the hypothesis that a streptococcus, having 

 peculiar neurotropic properties and isolated from cases of epidemic poliomyelitis, may 

 stand in causative relation to the disease. 



RHEUMATIC FEVER STREPTOCOCCUS ANTISERUM 



SmalP has reported the isolation of a strain of streptococcus from blood cultures 

 of patients suffering from acute rheumatic fever. This is a non-hemolytic strepto- 

 coccus repeatedly found in cases of this kind and is so distinctive as to warrant its 

 designation under a specific name — S. cardioarthritidis. A serum has been prepared 

 which apparently has considerable antibacterial value, as shown by the agglutinin 

 titre and the opsonic index. While still in the experimental stage, laboratory and 

 clinical work now in progress give every indication of confirming Small's observations 

 and of giving the serum a definite place in biological therapy. 



SCARLET FEVER STREPTOCOCCUS ANTISERUM 



A number of workers have demonstrated that the streptococci associated with 

 scarlet fever form a distinct serological group. When the Dicks demonstrated the 

 etiological relation of the scarlet fever strains of the streptococcus to the disease and 

 that this organism forms a soluble toxin which appears to be responsible for the 

 symptoms of scarlet fever, the necessity of producing sera of high antitoxic properties 

 was apparent. 



Preparation. — Two basic methods are at present employed. The first is that advocated 

 by the Dicks — namely, the subcutaneous injection of scarlet fever streptococcus culture 

 filtrates, which have been shown to produce a skin test in high dilution in susceptible indi- 

 viduals who have not had scarlet fever. After a period of several months the serum from 

 the animals can be shown to neutralize the substance which causes the skin reactions. The 

 final product is strictly an antitoxic serum, any antibacterial properties being lost during 

 concentration. 



The second is the method advocated by Dochez. A certain amount of semifluid agar is 

 injected under the skin of the animal. After the agar has solidified, a culture of living scarlet 

 fever streptococcus is injected into the center of the mass. The organisms proceed to grow 

 in this medium and give off their toxic products into the circulation. This method, however, 

 is likely to cause abscesses in the animals, and a modification proposed by Zinsser is more 

 useful. In this method citrated or oxalated hor.se blood is mixed with a culture of the strepto- 

 coccus, and just before injection enough calcium chloride is added to cause the coagulation 

 of the blood. The whole mass is rapidly injected under the skin, where clotting takes place. 

 This method has the advantage that it is much less likely to cause abscesses. Either of these 

 methods will produce an adequate therapeutic serum. 



In the beginning of the work on scarlet fever serum one of us (F.M.H.) preferred 

 to combine subcutaneous injections of the filtrate with intravenous injections of the 

 centrifuged organisms. This produces a combined antibacterial and antitoxic serum, 

 but the antibacterial portions of the serum are lost in the process of concentration. 



A detailed description of the method of immunization of horses for production of 

 this serum will be found in an article by Anderson and Leonard.^ The serum is 

 standardized on its antitoxic properties. 



" Small, J. C: Am. J. M. Sc, 173, loi. Jan., 1927. 



= Anderson, J. F., and Leonard, G. F.: ibid., 172, 334. Sept., 1926. 



