BILIAKY CALCULI 453 



a hypereliolesterolemia (Ilenes""'') ; that pregnancy, which seems to be 

 a predisposing cause of cholelithiasis, is accompanied by hyperchol- 

 esterolemia; that with hypercholesterolemia there is an increased out- 

 put of cholesterol in the bile, and that experimental hypercholesterole- 

 mia may lead to the formation of gall-stones without evident infection 

 of the bile tracts (Dewey °'^). As far as the existing evidence permits 

 one to draw conclusions, it would seeui probable that both local and 

 systemic conditions are of importance in gall-stone formation. Ap- 

 parently, gall-stones may form from cholesterol derived from the in- 

 flamed bile tract walls, independent of the amount of cholesterol pres- 

 ent in the bile ; but presumably they may derive part if not all the 

 cholesterol from the bile in some cases. In either event, a hyper- 

 cholesterolemia will favor their formation, and hence any given con- 

 dition of injury to the gall bladder will more often give rise to con- 

 cretions in persons with a high cholesterol content in the blood. 

 Changes in the bile itself may be produced by disease of the liver that 

 will alter its composition in such a way that its capacity to sustain 

 cholesterol in solution or suspension will be lowered,"*^ and this fac- 

 tor also cannot be dismissed as without importance ; transient thicken- 

 ing of the bile, such as may occur in any febrile disease, may also very 

 possibly initiate precipitation and stone formation.*^'*^ 



It w-as formerly supposed that the calcium-pigment concretions 

 were produced by the presence of excessive calcium in the bile, de- 

 rived particularly from lime-laden drinking-water, but it has been 

 demonstrated that increase of calcium in the food does not cause an 

 increase in the amount in the bile. Furthermore, on concentrating 

 bile, which contains both bilirubin and calcium, the free bilirabiu 

 separates out and not the calcium compound of bilirubin; and also, 

 Naunyn found that the bile salts prevent precipitation of calcium- 

 bilirubin, even when calcium salts are added in considerable amounts. 

 Apparently it is the presence of positively charged protein substances 

 that leads to the precipitation of this electro-negative substance from 

 bile, and hence the formation of pigment calculi is also favored or 

 initiated by inflammation of the bile tracts, particularly as most of 

 the calcium salts seem to come from the mucous membrane ; ^^ later, 

 as we have seen, these pigment concretions often become covered with 

 cholesterol derived from the injured epithelium, and the common mixed 

 calculi are then formed. In view of the fact that much of the pig- 

 ment in these calculi is composed of the oxidation products of bili- 



67a Surg., Gvn. and Obst.. lOlf, (2.3), 91. 



sTbArch. Int. Med., 1016 (17), 757; see also Aoyama, Deut. Zeit. Chir., 1914 

 (1.32), 234. 



cTcSee D'Amato, Biochem. Zeit., 1915 (69), .353. 



67dSee Rovsing. Hospitalstidende, 1915 (58), 249. 



(■■8 This commonly-held view is denied by Lichtwitz and Bock (Deut. med. 

 Woch., 1915 (41), 1215), who found the calcium content of bile from fistulas to 

 be from 65-84 mg. per liter, and in l)hidder bile to vary from 85 to 325 mg., but 

 not according to the presence or absence of inflammation. 



