498 THE CHEMIi^TIiV OF TUMORS 



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 

 (Amberg and Jones). Secondary tumors growing in the human liver 

 do not accjuire the enzyme, xanthine-oxidase, which is a characteristic 

 enzyme of tliis organ. The liver tissue between the cancer nodules 

 seems to oxidize purines less activelj^ than normal liver tissue. Long ^* 

 has also found similar conditions in tumors from sheep, pigs and 

 cattle, observing that primary carcinoma of the liver does not con- 

 tain xanthine oxidase, a point of interest in view of the fact that in 

 the development of mammals the xanthine oxidase does not appear 

 until late. 



Lipins. — Tumor cells seem to contain much the same fats and lipoids 

 as normal cells, and, so far as known, in much the same pro])ortions 

 as characterize the cells from which the tumors arose. Thus Wells ^^ 

 found that hypernephromas show the same high proportions of leeitlii]i 

 and cholesterol as he found in normal adrenal, and as are found in 

 the renal cortex. Other malignant tumors have much less lipoids and 

 fats (see Hypernephromas). A secondaiy carcinoma of liver cells^ 

 metastatic in the skull, was found by Prym ^^ to show the same sort 

 of fatty infiltration that is characteristic of fatty liver cells. On 

 account of the poor blood supply of many tumors, fatty changes 

 are usual, occurring under the same conditions and showing the same 

 microscopic features as fatty degeneration in other tissues,^^ being 

 more common in malignant than in benign tumors ; especially abun- 

 dant in squamous cell carcinomas, and scanty in sarcomas. Crystals 

 of cholesterol or cholesterol compounds are described in tumors by 

 White.^* Even lipoma fat shows no difference from normal fat,^** 

 and the depot fat of tumor patients is quite the same as in patients 

 with other diseases associated with equal wasting,^'^ in whom some 

 increase in unsaponifiable material (cholesterol) is usual. INIurray '*^ 

 saj's that the lipoids of degenerating uterine fibroids are strongly 

 hemolytic, which may account for the so-called ''red degeneration" of 

 these tumors. Freuncl and Kaminer *^ suggest that the fatty acids of 

 tissues are of importance in determining whether a tissue is a suitable 

 soil for secondary growth, these substances being deficient in tissues 

 where growths develop. There has been some effort to correlate the 

 cholesterol and lecithin contents of blood and tissues with the rate of 



34, Tour. Exper. Med., 1013 (18), rA2. 

 35 .Tour. Med. Res., 1908 (17), 461. 

 3«l'>ankf. Zeit. Palli., 1012 (10), 170. 



37 See lliifra, IJorl. klin. Wocli., ]:;]2 (40), ,342; Joamiovics, Wien. klin. Woeli., 

 1912 (25). 37. 



38 .Tour. Patli. and Haci.. 1!)0S (I.']). .3. 



39 See WellH, Arcli. Int. .Med., 1912 (10), 2!l7. 



■»" \\'acker, Zeit. ])hyfiiol. Cheni., 1!)12 (7S), :54!>; l!)12 (SO), ;5S.3. 

 41 Jour. Obst. Gvn.'lJrit. Knip., 1010 (17), 534. 

 4-:Wien. klin. Woch., 1012 (25), KiOS. 



