CARBOHYDRATES OF TUMORS 501 



tic tissue. However, the lack of any marked specific individuality 

 of cancer proteins when tested by immunological reactions, indicates 

 a very close chemical agreement with normal tissue proteins. ' 



On account of the amount of autolysis going on in tumors the 

 products of protein splitting are usually present. Beebe''' found in 

 a number of tumors leucine, tyrosine, tryptophane, proteoses (biuret 

 reaction), and in one glycine. Drummond" has found leucine, 

 tyrosine and creatinine commonly present in water extracts of malig- 

 nant tumors. Because of the deficient circulation in the tumors, the 

 amino-acids accumulate in the cancer tissues in sufficient amounts 

 to be detected, and may be found even when no macroscopic evidences 

 of degeneration are present. Possibly on account of this poor absorp- 

 tion no proteoses, peptones, or amino-acids could be found in the urine 

 of cancer patients by Wolff ;''^ but Ury and LilienthaP-* found a posi- 

 tive reaction for albumose in the urine in about two-thirds of all car- 

 cinoma cases examined by them; however, it may be absent even in 

 advanced stages. Lactic acid is also present in tumors, according to 

 Fulci^^ and Saiki,^^ the latter finding 0.48 gm. of lactic acid per 100 

 gms. cancer of the stomach. According to Clowes" cancer tissues 

 are much more permeable to ions than are normal tissues. 



(2) Other Organic Constituents. — These, in general, resemble 

 the organic constituents of the tissue from which the tumor arises, for 

 a structural resemblance to the parent tissue always exists, and as 

 structural features depend largely on the proportion of the chemical 

 components, a structural similarity fairh' implies a chemical similarity. 

 For example, adrenal and renal tissue contain much lecithin and choles- 

 terol, and hypernephromas show a similar composition; the fat of a 

 lipoma is, in its qualitative features, almost identical with the normal 

 fat of the same individual; tumor melanin shows no characteristic 

 chemical distinction from normal melanin, etc. 



Glycogen has been particularly studied in tumors, especially be- 

 cause of the erroneous idea advanced by Brault that the quantity of 

 glycogen is in direct proportion to the mahgnancy. From a sum- 

 mary of all the evidence, it seems that two chief factors determine the 

 presence and amount of glycogen in tumors. One is the embryonic 

 origin of the tumors; thus tumors of cartilage, striated muscle, or of 

 squamous epithelium, which tissues normally contain much glycogen, 

 are hkewise provided with an abundance of this material. Second, 

 the occurrence of areas of impaired cell-nutrition favors the accumu- 

 lation of glycogen in the degenerating tumor-cells just as it leads to 



31 Amer. Jour. Physiol, 1904 (11), 139. 

 « Biochem. Jour., 1917 (11), 246. 



35 Zeit. f. Krebsforschung, 1905 (3), 95. 

 3* Arch. f. Yerdauungskr., 1905 (11), 72. 

 " Gaz. internaz. dimed., 1910, No. 24. 



36 Arch. m^d. exp^r., 1911 (23), 376. 



37 Proc. Soc. Exp. Biol. Med., 1918 (15), 107. 



