418 BETROGRESSIVE CHANGES 



usual, are probably significant in the causation of diabetic lipemia. 

 (See also cholesterolemia.) 



Pathological Occurrence of Fatty Acids 



Fatty acids occasionally occur free in pathological processes. The 

 best example of this is fat necrosis (q. v.)., where crystals of fatty acids 

 appear in the necrotic fat-cells, arising through splitting of fat. and 

 later becoming combined with calcium from the blood. Similar 

 crystals, consisting of a mixture of palmitic and stearic acids, fre- 

 quently called margarin or inargaric acid crystals, may be found in 

 decomposed pus, in sputum from bronchiectatic cavities and from 

 gangrene of the lungs, in gangrenous tissue, and in atheromatous areas. 

 According to Schwartz and Kayser^'* the free fatty acids, at least in 

 pulmonary gangrene, arise from Hpolysis by bacterial action rather 

 than by the hpase of the tissues. Eichhorst found crystals of fatty 

 acids in the neighborhood of acute patches of sclerosis in the central 

 nervous system in multiple sclerosis, and McCarthy*^ found them 

 in a spinal cord undergoing secondary degeneration from compression. 

 Whipple^^ describes a case with deposits of fatty acids and neutral 

 fat in the wall of the intestine and the mesenteric glands, while soaps 

 and fatty acids are said to be present in excess in chronic appendicitis.^^ 

 Soaps and fatty acids, especially oleic acid and oleates, are highly 

 toxic, and their profound hemolytic power has been thought of im- 

 portance in pathological conditions, especially bothriocephalus anemia. ^^ 

 (See Hemolysins, Chap, ix.) The fatal dose of sodium oleate for 

 rabbits is 0.15 gm. per kilo (Leathes). The salts of higher fatty acids 

 above capric are hemolytic, while those from caproic down are not, 

 nonoic acid salts being the turning point (Shimazono).^^ The toxicity 

 of soaps may be related to their marked power to inhibit proteolytic 

 enzymes.^" 



The fatty acids may be stained green by copper acetate, according 

 to Benda's method, and if then treated with hematoxylin, they turn 

 black. ^^ With Nile blue sulphate they stain blue, forming a blue 

 salt, while the neutral fats are stained red by the oxazone base (J. L. 

 Smith). Fischler and Gross^- state that fatty acids are present in 

 atheromatous areas and about the margin of anemic infarcts, but 

 are not recognizable by this method in such fatty degenerations as 

 pneumonic exudates, caseation, etc. Klotz^^ considers that calcium 



«< Zcit. klin. Med., 1905 (56), 111. 



"Univ. of Penn. Med. Bull., 1903 (IG), 141. 



«« liull. Johns Hopkins Hosp., 1907 (IS), 382. 



"Anthony, Jour. Med. Res., 1911 (20), 359. 



'* Faust, Suppl. Bd., Schiuiedebcrp's Arch., 1908, p. 171. 



89 Z. Immunitat., Ilef., 1911 (4), 650. 



"".lobling and Petersen, Jour. Exp. IMod., 1914 (19), 251. 



«' Fischler, Cent. f. Path., 1904 (15), 913. 



82 Ziegler's Beitr., 1905 (7th suppl.), 343. 



" Jour. E.\p. Med., 1905 (7), 633. 



