496 THE CHEMISTRY OF TUMORS 



incoaon^ilable nitrogen being relatively increased; a given amount of 

 nitrogen produces more cancer than normal tissue. The water con- 

 tent of rapidly growing tissues, whether normal or cancerous, was 

 found to be high. This corresponds with the analysis of Robin,-" 

 who found the water content high and nitrogen low in carcinomas of 

 the liver, sulphur being especially low, and Chisholm -^ has found the 

 proportion of nitrogen in several human tumors lower than in the 

 somatic tissues. However, the lack of any marked specific individual- 

 ity of cancer proteins when tested by imnnmological reactions, indi- 

 cates 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 glycocoll. Because of the deficient circulation in 

 the tumors, the amino-acids accumulate in the cancer tissues in suffi- 

 cient amounts to be detected, and may be found even when no macro- 

 scopic evidences of degeneration are present. Possibly om account of 

 this poor absorption no proteoses, peptones, or amino-acids could be 

 found in the urine of cancer patients by AYolff : -^ but T^ry and 

 Lilienthal -* found a positive reaction for albumose in the urine in 

 about two-thirds of all carcinoma "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.-18 

 gm. of lactic acid per 100 gms. cancer of the stomach. 



(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 fairly implies a chemical simi- 

 larity. For example, adrenal and renal tissue contain much lecithin 

 and cholesterol, 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 charac- 

 teristic chemical distinction from normal melanin, etc. 



Glycogen lias 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 malignancy. From a summary 

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

 ence and amount of glycogen in tumors. One is tlie embryonic origin 

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



20 Cent. Plivs. Path. StoflFwechs., 1011 fd), .'i77. 



21 Jour. Pa'tliol. and l^act., 1013 (17). G06. 

 22Ainer. Jour. Physiol., 1004 (11), 130. 



23 Zeit. f. Krclisforschuiip, 1005 (3), 0,5. 



24 Arch. f. V(T(laiuiii-:skr., 100.5 (11), 72. 

 21 Gaz. interna/., di nied., 1010, No. 24. 



27 Arch. mC'd. e\[>6r., 1011 (23), 370. 



