310 IMMUNOLOGY 



method of separating the pseudoglobulin antibody fraction is ac- 

 complished by dialysis and "salting-out" of the pseudoglobulins. 

 For a more extensive discussion of tlie method employed and its 

 effect on serum proteins the student is referred to a report by 

 Weil, Parfentjev and Bowman (1938). 



Coghill, Fell, Creighton and Brown (1940) report on a new 

 concentration process for antitoxin which utilizes the enzyme- 

 complex Taka-diastase. The enzyme is permitted to act on the 

 immune horse serum for 3 to 5 daj'S at a pH of 3.5 to 4.5 and a 

 temperature of 37° C. Concentration is then accomplished by a 

 modified sodium sulfate (Na^SOi) salting out procedure. 



In all of these new methods of enz>nne treatment of immune 

 serum the antitoxin concentration is not impaired while the 

 biologic specificity and antigenic ]n-operties have been modified. 

 Coghill, et al., say that in addition to " despeciation " their process 

 also produces highly concentrated antitoxins that do not elicit 

 serious reactions upon injection into either lower animals or man. 



2. Serum Sickness in the Lower Animals. — In an excellent re- 

 view of Serum Allergy, Harten and Walzer (1939) call attention 

 to the production of serum disease in the horse by sera of cattle, 

 man and rabbits and to serum disease in cattle produced by horse 

 serum. Fleisher and Jones (1931, 1933, 1934, 1939) have pub- 

 lished extensively upon serum sickness in rabbits. They describe 

 the symptoms as elevation of body temperature, altered leucocyte 

 picture, and redness and swelling of the ears. The incubation 

 period was usually five or six days after a primary intravenous 

 injection of horse serum. They noted variation in the ability 

 of the sera of normal horses to produce "serum sickness" in 

 rabbits. 



3. Mechanism of Serum Sickness. — While Zinsser, Enders and 

 Fothergill (1939) seem to accept as an established fact the anti- 

 body theory of serum sickness proposed by von Pirquet and Schick 

 (1905), Harten and Walzer (1939) state that an analysis of all 

 available data does not support such a conclusion. 



In the theory of von Pirquet and Schick it is postulated that fol- 

 lowing the injection of horse serum the antibody is formed 

 gradually before the antigen is completely eliminated from the cir- 

 culation and that the newly formed antibody reacts with the cir- 



