Arroi.Yi^is J\ rATifOLdcicM. i'i;(>rEsi<Ei< 97 



Kzentkowski ^-' found an increase of non-i-oayulablc nitroficu in the 

 Wood of i)n('uni()iii('s, probably resulting from autolysis in the exu- 

 date. Aecordin<r to Dick"*' the blood serum after the crisis contains 

 an enzyme which acts specifically on the pneumocoecus proteins. In 

 the liver during experimental pneumocoecus septicemia, autolysis is 

 increased in rate.''''"' Almagia ^'^ suggests that the bactericidal action 

 of the jiroducts of fibrinolysis in ]nieumonia may be of importance in 

 checkinu' the disease. 



Necrotic Areas. — lacoby '"'" found that if a poi-tion of a dog's liver 

 Avas ligated oft* and tlie animal kept alive for some time, the necrotic 

 ti.ssue contained tlie same jiroducts that he had obtained in experi- 

 mental autolysis. The absorption of necrotic tissues generally is 

 ascribable to either autolysis or heterolysis. Presumably there is no 

 great difference in the self-digestion of an organ which is necrotic 

 because its blood supply is cut off, and of a similar organ removed 

 from the body aseptically and allowed to undergo aseptic autolysis 

 in an incubator. At the periphery there might be some effects pro- 

 duced in vivo by the inhibitive action of the serum or the digestive 

 action of the leucocytes, but beyond that no marked differences are 

 to be expected. In both cases asphyxia is present, leading to increased 

 acidity, without wliich little if any autolysis can occur. 



A study of the relation of autolysis to the histological changes that 

 occur in necrotic areas by Wells ^^ gave evidence that there occurs 

 early a decomposition of the nucleoproteins of the nuclei, which is 

 probably brought about by the intracellular autolytic enzymes. The 

 liberation of the nucleic acid and the reduction in the bulk of nuclear 

 material through the digestion away of the protein is probably the 

 cause of the pycnosis observed in necrotic areas. Later the nucleic 

 acids are further decomposed through the special enzymes described 

 by Jones, Sachs, and others, the "nucleases." This is presumably 

 the cause of the loss of nuclear staining so characteristic of necrosis. 

 That these changes are due to the intracellular enzymes was shown by 

 implanting in animals pieces of sterile tissues, the enzATnes of which 

 had been destroyed by heating; these were found to undergo altera- 

 tions only after several weeks, and then as the result of the action 

 tipon them of invading leucocytes. The slow rate of autolj-sis that 

 occurs in infarcts and other aseptic areas is presumably due in part to 

 the action of the antibodies of the serum, for it was found, experimen- 

 tally, that the histological clianges of autolysis when the tissues are 

 placed in heated serum proceed about twice as rapidly as w^hen they 

 are placed in fresh serum. Chemotactic substances do not seem to 



SGVirchow's Arch., 1005 (179). 405. 

 ST .Jour. Infect. Dis.. 1912 (10), .383. 

 8"a ^ledigreceanii. .Jour. Exp. :Med.. 1914 (19), 31. 

 8"b Festsclir. for Celli, Torino, 191.3. p. 459. 

 ssZeit. physiol. Cliem.. 1900 (30), 149. 

 89 Jour. Med. Research, 1906 (15), 149. 

 7 



