SOME CATALYTIC ASPECTS OF DISEASE AND DRUGS 229 



and other places exposed to light. Blum believes that the only 

 way to account for all the evidence is to assume that when a quan- 

 tum of light strikes a dye unit in a substrate-dye combination, the 

 dye portion is activated and thereupon transfers its activation to 

 the substrate, which then reacts with oxygen and injures cell struc- 

 ture. The reaction is evidently of catalytic nature, for it continues 

 steadily without continuous addition of dye. 



Cancer* 



From a clinical point of view cancer is a progressive growth of 

 somatic cells which are abnormal, which invade and injure healthy 

 tissue, and form abnormal structures that often become infected 

 and break down. Cancer cells, breaking away from the main mass, 

 may wander elsewhere in the body, and there establish new 

 cancerous growths (metatases). Furthermore, many cancer cells 

 duplicate themselves in tissue culture. It is therefore obvious that 

 in cancer we are confronted with a heritable change in the somatic 

 cell affected. The medical terms are in general descriptive, indi- 

 cating the tissue involved; e.g., glioma (nerve); carcinoma (epi- 

 thelium); sarcoma (connective tissue); nephroma (kidney), etc. 



A much clearer understanding of the basic cause of this protean 

 group of diseases emerges if we descend to the catalytic level of 

 biological happenings. For catalysts (genes, enzymes, symbionts) 

 dominate the chemical and physico-chemical changes which are 

 responsible for morphology and physiological function. Mere 

 heritable change in a cell is not alone enough to make it cancer- 

 ous, for, as has been pointed out, differentiation and evolution 

 both involve heritable catalyst changes in cells. It is the peculiar 

 and harmful consequences of the heritable catalyst change that 

 leads the clinician to make his diagnosis of cancer. 



It has long been known that the development of cancers in man 

 and animals is associated with exposure to certain influences, and, 

 more recently, to certain definite chemical substances. Thus the 

 natives of Kashmir, who often suffer from burns from a charcoal 

 brazier (kangri) which they carry about their waist, are prone to 

 develop kangri cancer. The British surgeon Sir Percival Pott ob- 

 served that chimney-sweeps frequently developed scrotal cancers; 

 and later it was noted that cotton spinners exposed to oils and 

 workers in tar and aniline factories show a high incidence of can- 



* See review by Professor Leo Loeb (Washington Univ.) in Vol. V, "Colloid 

 Chemistry," 1944. 



