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PHYSIOLOGICAL CHEMISTRY 



leucocytes, the character of the cast varying according to the nature 

 and size of the granules (Fig. 149, and Fig. 150, page 487). Thus 

 we have casts of this general type classified as finely granular and 

 coarsely granular casts. Granular casts, and in particular the finely 

 granular types, occur in the sediment in practically every kidney dis- 

 order but are probably especially characteristic of the sediment in in- 

 flammatory disorders. 



(c) Epithelial Casts. These are casts bearing upon their surface 

 epithelial cells from the lining of the uriniferous tubules (Fig. 151, 

 page 487). The basic material of this form of cast may be hyaline or 



FIG. 149. GRANULAR CASTS. (After Peyer.) 



granular in nature. Epithelial casts are particularly abundant in the 

 urinary sediment in acute nephritis. 



(d) Blood Casts. Casts of this type may consist of erythrocytes 

 borne upon a hyaline or a fibrinous basis (Fig. 152, page 487). The 

 occurrence of such casts in the urinary sediment denotes renal hemor- 

 rhage and they are considered to be especially characteristic of acute 

 diffuse nephritis and acute congestion of the kidney. 



(e) Fatty- Casts. Fatty casts may be formed by the deposition of 

 fat globules or crystals of fatty acid upon the surface of a hyaline or 

 granular cast (Fig. 153, page 488). In order to constitute a true fatty 

 cast the deposited material must cover the greater part of the surface 

 area of the cast. The presence of fatty casts in urinary sediment in- 



