502 THE CHEMISTRY OF TUMORS 



a similar accumulation in all other tissues (Gierke). ^^" The most ex- 

 tensive consideration of this topic is reported by Lubarsch,^^ who 

 found glycogen microscopically in 447 (or 29 per cent.) of 1544 tumors 

 examined. It was present in but 3 out of 184 fibromas, osteomas, 

 gliomas, hemangiomas, lipomas, and lymphangiomas, and in but 2 

 out of 260 adenomas from various parts of the body. It occurred in 

 all teratomas, rhabdomyomas, hypernephromas, and syncytiomas. 

 In 138 sarcomas glycogen was present in 70 (50.7 per cent.); of 415 

 carcinomas it was found in 181 (43.6 per cent.). In the squamous 

 epithelial cancers 70 per cent, contained glycogen, while the mucoid 

 or colloid cancers were always free from glycogen. The glycogen 

 undoubtedly enters the cells from without, probably entering as sugar, 

 and being converted into glycogen by intracellular enzymes. We have 

 no rehable studies of the actual quantity of glycogen in various tumors, 

 although Meillere^^ states that the microscopic and chemical examina- 

 tion of tumors give corresponding comparative results, which Gierke 

 states is generally true with glycogen estimations. 



Pentoses. — Neuberg'*'^ reports finding, as a product of autolysis of a 

 carcinoma of the liver, a pentose which was not produced by autolysis 

 of either normal liver tissue or the primary growth in the stomach. 

 Beebe*^ found that in carcinoma of the mammary gland the percentage 

 of pentose (xylose) is somewhat higher than the amount in normal 

 mammary glands f about 0.23 per cent.). Carcinoma in the hver did 

 not show any constant excess of pentose above that of normal liver 

 tissue (about 0.38 per cent.). A primary carcinoma of the liver 

 showed quite the same pentose and phosphorus content as normal 

 liver tissue. In general, no constant relation of pentose to origin, 

 mahgnancy, or degeneration of tumors was observed. 



Purines and Purine Enzymes. — ^The purines of both benign and 

 malignant tumors have been studied by Wells and Long, ''- who found 

 them the same as those in normal tissues, and in much the same rela- 

 tive proportions. The proportion of the total nitrogen of tumors 

 which is constituted by the purine nitrogen is less than would be ex- 

 pected from the histological evidence of the amount of nuclear material 

 contained in the tumors. Tumors also seem to contain much the 

 same purine enzymes as the normal tissues. Thus, guanase seems uni- 

 versally present in tumors derived from human tissues, and adenase 

 is missing, although autolyzing tumors can disintegrate their nucleic 

 acid (nuclease) and change the adenine radicals of the nucleic acid 

 into hypoxanthine, presumably by way of adenosine and inosine ( Am- 

 berg and Jones). Secondary tumors growing in the human liver do 



"« Ziegler's Beitr., 1905 (.37), 502. 



'8 Virchow's Arch., 190G (183), 188. 



3» Coinpt. Rend. Hoc. Biol., 1900 (52), 324. 



" Berl. klin. Woch., 1904 (41), 1081; 1905 (42), 118. 



"' Arncr. Jour. Physiol, 1905 (14), 231. 



*■' Zeit. f. Krebsforsch., 1913 (12), 598. 



