ANTI-ENZYME IMMUNITY 357 



In the third study (Kellaway and Trethewie, 1941), they reported 

 their findings on Types B and C toxins of CI. welchii. The M.L.D. 

 of type B toxin for 20 g. mice was 0.04 mg. It was non-hemolytic and 

 therefore probably contained no a-toxin. The M.L.D. of type C toxin 

 for 20 g. mice was 0.007 mg. The antitoxin used neutralized 16,000 

 to 32,000 mouse M.L.D. per ml. Since antitoxin against type C toxin 

 caused severe circulatory effects in cats and the contraction of the 

 jejunum and uterus of guinea pigs, particularly when mixed with 

 toxin, it was purified by precipitating the globulin fraction, which 

 eliminated the toxic effects. 



The toxin of CI. welchii type D set free both histamine and adenyl 

 compounds, while type A liberated adenyl compounds but not hista- 

 mine from perfused organs. The toxins of all the four types liberated 

 adenyl compounds from the isolated perfused liver of the rabbit. 

 Though the preparation of type B toxin liberated histamine, it was 

 ascribed to the presence of the e-fraction. Both toxins B and C caused 

 liberation from the perfused liver of the rabbit, of pigment, of 

 adenyl compounds and of a heat labile agent which inactivates these 

 latter compounds. Both toxins caused the contraction of the isolated 

 jejunum of the guinea pig and of the uteri of the virgin guinea pig 

 and rat. These responses were shown to be specific except that of the 

 isolated uterus of the guinea pig to type B toxin— in which a his- 

 tamine-like impurity was present. 



5. Action of Antitoxin on Enzymes Causing Histolog- 

 ical Changes in Gas-Gangrene 



Robb-Smith (1945) compared the histological changes occurring in 

 muscle lesions in gas-gangrene in man with those occurring in human 

 muscle in vitro as the result of the action of CI. welchii type A filtrate. 

 It was found that the changes occurring under these two conditions 

 were identical. These changes were considered to be due to effects by 

 the enzymes in the filtrates on cell-membranes, cell-nuclei, collagen 

 and reticulin, and mucoproteins, and that the myofibrils were un- 

 affected. Antitoxin inhibited these reactions, suggesting that the local 

 injection of antitoxin might be used advantageously where it has 

 proved impossible to perform an adequate surgical excision of the 

 affected tissue. However, on the basis of an extensive study of the rate 



