496 PATHOLOGICAL PIGMENTATION 



to form new hemoglobin, and hence the functional capacity of the 

 liver is indicated by the completeness with which it utilizes the uro- 

 bilin, except in cases of excessive formation of urobilinogen as a re- 

 sult of hemolysis. The amount of urobilinogen in the urine will be 

 found increased, therefore, in hemolytic icterus, and decreased in ob- 

 structive icterus. Exceptionally, urobilinogen may be formed from 

 blood disintegrated in bloody effusions without evident participation 

 of the liver, e. g., urobilinogenuria with hemorrhagic ascites, hemolytic 

 poisons, etc. With a normal liver urobilinogenuria is found only 

 when there is excessive hemolysis, otherwise urobilinogenuria occurs 

 only with an injury to the liver parenchyma (Hildebrant). In general, 

 the amount in the urine is an index of the amount of blood destruction.^^ 

 There seems to be little if any retention by imperfectly functioning 

 kidneys (Blankenhorn) and it can often be found in the urine when not 

 demonstrable in the blood. Occlusion of the bile ducts stops an ex- 

 isting urobilinogenuria by preventing the formation of urobilinogen 

 in the intestine. Normally there is a very small amount of urobilin- 

 ogen and related substances in the urine, which disappears when 

 there is no bile in the intestine. Fromholdt^^ considers that increased 

 ■ bacterial reduction in the intestines may by itself account for uro- 

 bilinogenuria. The amount of urobilin and urobilinogen excreted in 

 the feces, seems to vary directly with the amount of hemolysis, ^^ and 

 the same is true for the duodenal contents.'^' The evidence of abnor- 

 mal hemolysis is said to occur first in the stools, then in the duo- 

 denal contents, and lastly in the urine; the presence of even small 

 amounts of urobilinogen in the urine being evidence of a probable per- 

 nicious anemia in the absence of signs of biliary and hepatic disease.^-" 



Digestive Disturbances in Obstructive Icterus." — In case the icterus depends 

 upon the occlusion of the main bile-passages by stones, tumors, etc., the situation 

 is complicated by the effects of the absence of this natural secretion in the in- 

 testinal canal. Carbohydrate and protein digestion seem to be but little affected, 

 especially the former, but the proportion of the ingested fat that appears in the 

 feces increases from the normal 7-11 per cent, to GO-<SO per cent. The products 

 of bacterial decomposition of the undigested fat may lead to injury of the in- 

 testinal wall and disturbance of its function. Failure of absorption of fat also 

 favors intestinal putrefaction by enveloping the protein substances so that they 

 are not readily digested and absorbed. The relation of bile to intestinal putre- 

 faction is still not exactly determined. Frequently, but by no means always, 

 there is an increased intestinal putrefaction which may result in diarrhea and 

 the appearance of excessive quantities of indican and phenol in the urine. The 

 idea once held that the bile salts acted as intestinal antiseptics has not been 

 established by experimental investigations; however, it is possible that through 

 their function as natural cathartics, by stimulation of peristalsis, they prevent 

 stagnation and putrefaction of proteins. 



»» Dubin, Jour. Exp. Med., 1918 (28), 313. 

 '0 Zeit. exp. Path., 1911 (9), 268. 



71 Robertson, Arch. Int. Med., 1916 (15), 1072; McCrudden, Bost. Med. Surg. 

 Jour., I!tl7 (177), 907. 



" Gifhn, Sanford and Szlapka, Amer. Jour. Med. Sci., 1918 (155), 502. 

 ''''' Hausmann and Howard, .lour. Amer. Med. Assoc, 1919 (73), 1202 

 "Concerning metabolism in icterus .:ee Vannini, Zeit. klin. Med., 1912 (75), 136. 



