ENZYMES OF TUMORS 501 



tumors. Nucleases have been found in tumors as in otlier tissues,"^ 

 and in general the enzymes which deamidize adenine and guanine (ad- 

 enase and guanase) are usually present if the original tissue possessed 

 these enzymes, but no instance of tlie presence of xanthine oxidase 

 or uricolytie enzyme has been obtained (Wells and Long, loc. cit.^^). 



Hamburger finds that the enzymes of cancer tissue upon which the 

 glycyl-tryptophane and other enzyme tests for cancer are based, are 

 ereptases, resembling in all thinr properties the ereptases of -normal 

 tissues, and not })resent in particularly large amount. However, Ab- 

 derhalden ^^ has found evidence that certain peptids may be split in a 

 different way by cancer than by normal tissues, supporting those who 

 hold that cancer enzymes are different from normal tissue enzymes. 

 Autolysis of tumors is said to be augmented by x-ray, and especially 

 by radium (Neuberg), and tumor tissue is readilj^ digested by tryp- 

 sin. 



The presence of ereptases in carcinomatous gastric juice has been 

 especially studied because of its diagnostic possibilities, and the care- 

 ful investigation of Jacques and Woodyatt "^ seems to show conclu- 

 sively that such an enzyme is rarely present in gastric juice except 

 when derived from a cancer present in the wall of the stomach, pro- 

 vided peptolytic bacteria are excluded by filtration. Deaminizing 

 enzymes may also be found in gastric cancer secretions.*'^" In the blood 

 of cancer patients there is usually an increased antitrj^ptic activity, 

 ascribable to the reaction against enzymes absorbed from the cancer; 

 it is less pronounced with sarcoma.*'^ The body tissues of patients 

 dying with cancer show a low ereptic activity, but the same is true of 

 persons d.ying from other wasting diseases ( Colwell ) ."'' The same 

 seems to be true of other tissue enzymes ; — at least purine oxidizing 

 enzymes are deficient in the liver tissue between secondary cancers 

 (Wells and Long^^) and the eatalase is also reduced in liver tumors 

 (Blumenthal and Brahn) ^'' and in the blood of tumor mice (Rosen- 

 thal)''^ ; in human blood the eatalase may vary either side of normal.®*^ 

 Brahn °^^ found that liver metastases of gastric cancer contained no 

 lipase or lecithinase, which enzymes were also reduced in the liver tis- 

 sue between cancer nodules. However, choline has been found in 

 necrotic sarcomas of rats,"*'' which would seem to indicate the presence 

 of enzymes disintegrating lecithin. As mentioned elsewhere (Mela- 



62 Goodman. Jour. Exp. Med., 1912 (15), 477. 



63 Zeit. Krebsforscli., 1010 (9), 2fi6. 

 6-tArch. Int. INled., 1912 (10), 560. 



64aHalporn, Mitt. Grenz. Med. Chir., 1915 (28), 709. 



65 Citronblatt, Med. Klin., 1912 (8), 1.38. 



66 Arch. Middlesex Hosp., 1909 (15), 96. 

 6T Zeit. f. Krebsforsoh., 1910 (8), 436. 

 csDeut. med. Wocli., 1912 (.38), 2270. 



68a Rohdonburo:, X. Y. ]\Ied. .Tour., 1913 (97), 824. 

 esbSitzber. kpl. preuss. Akad. Wiss.. 1916 (20), 47-8. 

 68c Euinger, Miinch. mod. Woch., 1914 (61), 2336. 



