AUTOLYSIS IN PATHOLOGICAL PROCESSES 99 



cytes do not enter tlic caseous area. Jobling and Petersen "^'^ find 

 evidence that the soaps of unsaturated fatty acids present in tubercles 

 are responsible for the inliibition of digestion. Spietliolf ''^ found 

 that pure caseous material is usually free from even traces of albumose 

 and peptone, but the caseous material at the periphery mixed with 

 tissue elements contains them in very small quantities, suggesting that 

 at the periphery of caseous areas some slight autolysis does occur. The 

 fact that B. tuhcrculosis is, itself, very poor in proteolytic enzymes as 

 compared with most other bacteria may be another factor. When 

 leucocytes are attracted into a tuberculous focus softening goes 

 on rapidly, showing that there is no loss of digestibility of the caseous 

 material, but merely a lack of enzymes. Pus from a cold tuberculous 

 abscess will not digest fibrin, but if iodoform is injected, leucocytes 

 enter in great numbers, softening is rapid, and the pus will then di- 

 gest fibrin (Heile^®). On serum plates tuberculous pus produces no 

 digestion unless a secondaiy infection or other cause has resulted in 

 a local accumulation of leucocytes.^ Tuberculous material contains, 

 like the lymphocytes, an enzyme which is proteoh'tic in acid media 

 and which is inhibited by normal serum (Opie and Barker-). 



Correlation of Histological and Chemical Changes. — A careful study 

 of the relationship of the chemical changes produced by autolysis, to 

 the histological changes of necrosis and autoh'sis, has been made by 

 H. J. Corper,^^ and colored plates published together with analytical 

 figures make it possible to correlate at a glance the structural and 

 chemical changes of necrobiosis. Corper found that in the early 

 stages, characterized by a high grade of pycnosis but no further nu- 

 clear changes, the nucleins are still intact; but with well developed 

 karyorrhexis and beginning karyolysis, some ten per cent, of the nu- 

 clein nitrogen has become soluble in the form of purine bases. Wlien 

 karyolysis is completed so that no more nuclei remain in a stainable 

 condition, only twenty-eight per cent, of the purines was found to 

 have been decomposed to free purine bases,®^'* the remaining seventy- 

 two per cent, being intact although unstainable. This rather surpris- 

 ing observation indicates that the stainable chromatin represents but 

 about one-fourth of the nucleins of the cell, which is in accord with 

 the views of Hammarsten and others. The lecithin disintegrates 

 somewhat more completely, about one-half or two-thirds being disin- 

 tegrated by the time nuclear destmetion is complete, after which this 

 and all other autolytic change is slow. The change from coagulable 



97a .Jour. Exp. Med., 1914 (19), 38-3. 

 05 Cent. f. inn. Med., 1904 (25), 481. 

 90 Zeit. klin. IMed., 1904 (55), 508. 

 1 See Wiens, Joe. citJ5 

 2. Jour. Exper. Med., 1900 (11), 686. 

 93 Jour. Exper. Med., 1912 (15), 429. 



93a Marshall (Jour. Biol. Chem., 1913 (15), 81) has also found that much of 

 the nucleic acid remains unaltered in autolysis of thymus. 



