VETERINARY MEDICINE. 385 



Protective enzyms, cytotoxic immune sera, and anaphylaxis, R. M. Pearck 

 luul P. F. Williams (Jour. Infect. Diseases, I4 UDl^), No. 2, pp. 351-363).— 

 " On the basis of Abclerhalden's theory of protective enzyms and by the use 

 of his dialysis method it has been shown that the serum of a rabbit receiving 

 a single injection of kidney substance develops the power to digest dog's 

 kidney in vitro, but has no effect upon the kidney of the dog when administered 

 intravenously. Thus it would appear that the so-called protective enzyms 

 are not to be classed with the immune cytolysins. The digestive power of the 

 serum which develops after the injection of kidney is not limited to the kidney 

 but acts also upon the liver. This is true after one injection or after four or 

 five injections. There is some evidence, however, after multiple injections of 

 a tendency to a more definite effect on the kidney than on the liver. 



"A few attempts to demonstrate protective enzyms in the serum of dogs 

 receiving dog's kidney and of animals with experimental nephritis have failed. 

 Attempts to demonstrate protective enzyms in the serum of dogs sensitized to 

 horse serum have not been as successful as those of Abderhalden with the 

 serum of the guinea pig sensitized to egg-white. Negative results have been 

 the rule before shock, and ix»sitive results, difficult of explanation, after shock. 

 Dialysis, alone, of small amounts (2 cc.) of serum, obtained either before or 

 five to ten minutes after ' shock ' in dogs sensitized to horse serum, gives no 

 evidence of the presence of the products of protein disintegration. Larger 

 amounts (10 to 20 cc.) taken 1 to 1* hours after shock give positive results 

 after dialysis, but the interpretation of these is doubtful on account of the 

 difficulty, under these circumstances, of obtaining serum free of traces of 

 hemoglobin. 



" The results of the injection of renal tissues support Abderhalden's general 

 contention concerning protective enzyms, but indicate a lack of sp^ifieity. On 

 the other hand, the work with anaphylaxis, while suggestive, is not sufficiently 

 definite to be used in support of the theory that the essential mechanism of 

 anaphylaxis can be explained on the theory of the development of a protective 

 enzym. 



" Finally, the authors state that on account of the many difficulties which 

 the technique of this method presents — and esi^ecially because of the frequent 

 presence of ninhydrin reacting substances in the serum of normal animals — 

 thus rendering exact control observation difficult, these results are presented 

 with some hesitation. Moreover, without desiring to detract in any way from 

 the importance of the underlying principle of Abderhalden's theory of protective 

 enzyms as exemplified by his work on pregnancy, we urge caution as to hasty 

 attempts to apply this theory as a general explanation of widely diverse con- 

 ditions of altered physiology." 



Studies on so-called protective ferments. — I, The sensitization of sub- 

 stratum for the Abderhalden test, J. Beonfenbeenner, W. T. Mitchell, jr., 

 and M. J. Schlesinger {Biochem. Bui, 3 (lOUf), No. 11-12, pp. 3S6-389).— 

 This is an attempt to determine whether the substances brought into play in 

 the Abderhalden reaction are of the nature of antibody, as " antibody " was 

 understood in 1909, or whether they are entirely different. 



The result of the work, while it does not seem to furnish definite proof that 

 the nature of defensive ferments is identical -with that of the antibody or 

 amboceptor, is nevertheless said to contribute additional evidence to the effect 

 that a certain amount of parallelism between the two apparently exists. In 

 these investigations it was found that " there was not only no dialysis in the 

 containing placenta and the pregnant serum when the temperature was low, 



