202 HEMOLYSIS AND SERUM CYTOTOXINS 



chocolate-colored, and the pyramids are comparatively light : 

 hemoglobin is frequently present in the urine. In the lungs 

 are often found hemorrhages or areas resembling small infarcts. 

 The blood may be thin and even distinctly transparent. Micro- 

 scopically the red corpuscles are found in all conditions of 

 degeneration, and often fused together. In the liver, besides 

 patches of congestion, fatty changes are present if the animal 

 lives long enough. Large phagocytic cells packed with red 

 corpuscles are abundant in the spleen and lymph-glands, as 

 well as diffuse accumulations of the blood-cells, which are often 

 fused ; and much pigment is also present, both free and in the 

 cells. Pigment also accumulates in the renal epithelium, which 

 often shows much disintegration ; congestion is prominent, and 

 hemorrhages into both interstitial tissue and glomerules are 

 frequent. Some of the lesions are due to the hemolysis, and 

 some to the associated agglutination of corpuscles, which form 

 hyaline thrombi. 



Agglutination of corpuscles in the vessels during life is 

 undoubtedly of much pathologic importance, for such masses 

 of agglutinated corpuscles may produce extensive formation of 

 capillary thrombi and emboli, from which serious results may 

 be produced. (See "Hyaline Thrombi," Chap, xi.) Many 

 bacteria produce substances that are agglutinative for human 

 red corpuscles, among them being such important disease- 

 producers as typhoid, pyocyaneus, and staphylococcus. Flexner l 

 has found in typhoid fever thrombi that seemed to be composed 

 of agglutinated red corpuscles, practically free from fibrin and 

 leucocytes. Probably many of the " hyaline thrombi " frequently 

 found in infectious diseases are really composed of agglutinated, 

 partly hemolyzed red corpuscles. Pearce 2 has found that 

 agglutinative serum when injected into dogs causes wide- 

 spread necrosis in the liver, which is followed by proliferation 

 of connective tissue and the production of changes resembling 

 cirrhosis. 



CYTOLYSIS IN GENERAL 



Not the same degree of success has been obtained in immunizing 

 against other tissue elements as with the erythrocytes. Immune 

 serum can readily be obtained against cells that can be secured 

 quite free from other cells, such as spermatozoa, ciliated epithe- 

 lium, and leucocytes, but even then the immunity is not specific. 



1 Univ. of Penn. Med. Bull., 1902 (15), 324; Amer. Jour. Med. Sci., 1903 

 (126), 202. 



2 Jour. Exp. Med., 1906 (8), 64; Jour. Med. Kesearch, 1906 (14), 541. 



