SERUM THERAPY 607 



Curative properties. 1 c.c. of the serum will save the life of a rabbit inocu- 

 lated 3 hours previously with 10 times the lethal dose of an exalted (passage) 

 virus : 5 c.c. will in like manner cure rabbits inoculated 5 hours previously : 

 but in the case of animals inoculated with the virus 6 hours before the admini- 

 stration of the serum, the latter is powerless to prevent infection. When an 

 organism of ordinary virulence for the lower animals is used as the test 

 [streptococci taken direct from human lesions are sometimes non- virulent for 

 animals], inoculation of serum even 24 or 30 hours later leads to the recovery 

 of the animal. 



According to Behring and Knorr, Marmorek, Aronson and others, if an animal be 

 immunized against one strain of streptococcus it is equally immunized against related 

 strains and the serum is efficient in both cases. This opinion would, however, not 

 seem to be justified by clinical experience : thus, Mery was unable with Marmorek' s 

 serum to immunize rabbits against a streptococcus isolated from the blood of a 

 case of scarlet fever (vide infra) and Courmont has proved that a serum prepared 

 according to Marmorek' s directions is only effective against the strain used for its 

 preparation and not against strains from other sources. 



Use of Marmorek's serum in practice. Marmorek's serum has been used 

 in cases of streptococcal infections in man but without any striking result. 



In cases of erysipelas and puerperal septiccemia the results have not come up to 

 expectation. The serum is generally inoculated in doses of 10 c.c. repeated, if 

 necessary, daily for a week or more : in serious cases 20 c.c. has been the initial 

 dose. 



In scarlet fever, Marmorek's serum has yielded encouraging but not conclusive 

 results. [It is conceivable that these results were obtained in those cases which 

 are very common in which the streptococci were associated as a secondary 

 infection. ] 



In cases of faucial diphtheria in which streptococci are present as a secondary 

 infection, Roux has tried mixing antidiphtheria serum with the serum of rabbits 

 immunized by Marchoux against streptococci : the results were not successful. 

 Martin used Marmorek's horse-serum in combination with antidiphtheria serum and 

 obtained rather more satisfactory results. 



In the disease known as anasarca of the horse, caused by a streptococcus similar 

 to those found in man, Marmorek's serum has given good results (Nocard and others) 

 and has lowered the death-rate considerably. 



Aronson 's serum. Like Marmorek, Aronson regarded all streptococci 

 occurring in human disease processes as belonging to one and the same species. 

 His investigations were carried out on 17 strains of streptococci. 



Preparation of the serum. Aronson increased the virulence of the organism by 

 passing it through a number of mice. In this way a streptococcus was obtained 

 which would kill mice in a dose of 0*000,000,01 c.c. of a glucose-broth culture. 

 Horses were then immunized with increasing doses of this passage virus. 



The serum of these animals is prophylactic in the case of mice against 

 streptococci of human origin provided always that the virulence has been raised 

 by passing it through mice. It does not protect mice against the streptococcus 

 of strangles (Chap. XLII.) when first isolated from the horse but is very efficient 

 against that organism when it has been passed through several mice. 1 



The prophylactic properties of Aronson's serum are shown by the fact that if 

 0'0002 c.c. be inoculated into the peritoneal cavity of a mouse and 24 hours later 

 one hundred fatal doses of a passage virus be inoculated, the mouse survives. 



Aronson's serum also possesses curative properties. 



Thus, if inoculated 7 hours after an intra-peritoneal inoculation of the virus the 

 animal recovers, and even if the administration of the serum be delayed for 24 hours 

 it still leads to recovery in 50 per cent, of the animals. 



1 Marmorek's serum has very little effect on a virus which has been passed through 

 mice. 



