UREA 



366 



URINE 



Employed by HoUande for bacteriocytes 

 of Periplaneta orientalis L (HoUande, 

 A. C, Bull. d'Histol. Appl., 1931, 8, 

 176-178). 



Urea. Many histochemical techniques have 

 been proposed. Leschke (E., Zeit. 

 Klin. Med., 1915, 81, 14-35) fixes in 

 half sat. sol. mercuric nitrate in 1% 

 nitric acid for 1 day, then washes in 

 frequently changed aq. dest., imbeds 

 in paraffin and treats the sections with 

 sat. aq. hydrogen sulphide staining 

 nuclei with hemalum. Stiibel (H., 

 Anat. Anz., 1921, 54, 237-239) fixes small 

 pieces in 6% xanthydrol in glacial acetic 

 acid 6-12 hrs., imbeds in paraffin, stains 

 sections by ordinary methods and 

 examines by polarizing microscope. 

 Oliver (J., J. Exper. Med., 1921, 33, 

 177-186) employs instead a solution 

 containing 2 gm. xanthydrol, 10 cc. 

 methyl alcohol and 20 cc. glacial acetic 

 acid. Lison (p. 169) criticizes these 

 methods severely. 



It may be necessary to resort to the 

 capillary tube colorimetric technique 

 of Walker, A. M. and Hudson, C. L., 

 Am. J. Physiol., 1937, 118, 153-166, 

 or to the titrimetric method of Kinsey, 

 V. E., and Robison, P., J. Biol. Chem., 

 1946, 162, 325-331. 



Urease. A method for determining the 

 distribution of urease in the gastric 

 mucous membrane (pylorus and fundus) 

 of the dog has been d.escribed and used 

 by Linderstr0m-Lang and Ohlsen (K. 

 and A. S., Enzymologia, 1936-37, 1, 

 92-95). Cylinders of tissue (2.5 mm. 

 in diameter) are cut vertical to the 

 surface from frozen mucosa. Cross 

 frozen sections (25 microns thick) 

 of the cylinders are then tested for 

 urease. This is concentrated in the 

 surface layers containing cells stainable 

 with mucicarmine. Chief cells in the 

 bases of the glands are inactive in both 

 fundus and pylorus and the authors 

 think it very unlikely that the parietal 

 cells contain urease. 



For help in the problem of adapting 

 methods for urea to urease see Glick, 

 p. 287. 



Uremia. Microscopic demonstration of 

 uremia by precipitation of xanthydrol 

 urea in tissue. A modification of 

 Oestreicher's original method is pro- 

 vided by Brown, A. F. and Krajian, 

 A. A., Arch. Path., 1936, 21, 96-99. 



Cut blocks of tissue 2-3 mm. thick. 

 Immerse in fresh xanthydrol solution 

 (xanthydrol, 5 gm., glacial acetic acid 

 100 cc.) at 80°C. for 2 hrs. Wash in 

 running water, 5 mm. Fix in 1 part 

 formaldehyde U.S. P. and 10 parts aq. 

 dest. at 70°C. for 15 min. Wash in tap 



water and cut 5-10/x frozen sections. 

 Transfer them to slide and pour on 

 several drops "dehydrated alcohol" 

 (presumably abs. ethyl ale.) from a drop 

 bottle and blot. Repeat. Cover by 

 dipping in thin pyroxylin (celloidin) 

 contained in wide mouthed bottle. 

 Fix film of pyroxylin to slide by blowing 

 breath over section and stain in 1% aq. 

 eosin for several minutes. Wash in 

 water, dehydrate in 3 changes dehy- 

 drated alcohol, place in carbol-xylene, 

 clear in 2 changes pure xylene 1 min. 

 each and mount in dammar. Xanthy- 

 drol urea crystals appear as closely 

 packed clusters of yellow-green needles. 



Uric Acid. Micro colorimetric method, 

 Borsook, H., J. Biol. Chem., 1935, 

 110, 481-493. See Urates. 



Urinary Casts, staining with methyl blue 

 picric acid. To sediment from centri- 

 luged urine add 1 drop 0.5% aq. eosin. 

 Mix by side to side shaking. After 1-2 

 min. add 2 drops from 1 cc. 1% aq. 

 methyl blue + 10 cc. sat. aq. picric acid 

 and again mix. Color of sediment 

 should be distinctly bluish green. If it 

 is reddish brown add more methjd blue- 

 picric acid. Transfer to slide cover 

 and examine. The casts should be dis- 

 tinct blue but not too dark. Numerous 

 details are brought out (Behre, J. A. 

 and Muhlberg, W., J. Lab. & Clin. Med., 

 1936-37, 22, 853-856). See the author's 

 figures. 



Urinary Sediments. The following outline 

 is from Stitt (pp. 707-713) much ab- 

 breviated. Concentrate sediment by 

 centrifuging 15 cc. fresh urine 1500 

 r.p.m. 5 min. but not longer. Decant 

 supernatant urine. Suspend sediment 

 in 2 cc. urine as is the practice in the 

 Naval Medical School. By always using 

 these amounts quantitative differences 

 from normal in individual sediments 

 become apparent. Examine for epi- 

 thelial cells, leucocytes, erythrocytes, 

 casts, crystalline materials, bacteria 

 and so forth. 



Urinary Tract Smears, see Papanicolaou 

 Techniques. 



Urine. For microscopic study sediments 

 are divided into classes. 



Details with helpful diagrams are sup- 

 plied by C. J. Gentzkow and H. A. Van 

 Auken in Simmons and Gentzkow, 

 26-33. 



Unorganized components depending 

 chiefly on metabolic activities and 

 changes in content of bladder before 

 urination. See also Sulfonamides. 

 Examine for: 

 In acid urines 

 Urates, as pink amorphous mate- 

 rials 



