Renal Calculi Including 

 Phosphaturia and Oxaluria 



JACOB ROSENBLOOM 



PITTSBURGH 



I. Introduction 



Before a pathological concretion may form it is essential that there he 

 a nucleus of some substance different from the substance to be deposited. 

 Upon the nucleus substances crystallize out of solution and only in a few 

 cases would the concretion form, w r ere it not that the solution contains an 

 excess of some substance. However, the nucleus may, in certain instances, 

 cause the precipitation of the substance. Concretions consist, therefore, 

 of mixtures of colloids, and crystalloids deposited from the solutions of 

 colloids and crystalloids, and, on this account, the application of the prin- 

 ciples of colloidal chemistry throws considerable light on the conditions of 

 their formation. It is to be remembered that the constituents of urinary 

 calculi are derived from the secretion of the kidneys and are usually de- 

 posited on account of an oversaturation of the urine or on account of a 

 change in the composition of the urine, which renders them insoluble. 

 Although the amount of colloidal material in the urine is small, it plays an 

 important part in keeping in solution the less soluble crystalloids, such as 

 urates and calcium oxalate. In inflammatory conditions fibrinogen ap- 

 pears, which readily forms the irreversible fibrir and conditions thus be- 

 come favorable for the formation of concretions made up of any crystalloid 

 that the urine may be saturated or oversaturated with at that time. 

 Aschoff and Kleinschmidt claim that most urinary calculi begin as pri- 

 mary calculi formed independent of any inflammation, but from an excess 

 of the main constituent (uric acid, oxalates, xanthin, ammonium urate) ; 

 this calculus then forms the crystalline nucleus of the laminated secondary 

 deposit of other substances (uric acid, oxalates, and phosphates) ; all being 

 deposited without inflammation. The inflammatory formations are usu- 

 ally deposited on a foreign body or a primary calculus and are composed 

 chiefly of ammonium-magnesium phosphate and ammonium urate. 



Urinary calculi commonly consist of the following substances: uric 

 acid, ammonium urate, xanthin, cystin, calcium carbonate, calcium oxa- 

 late, calcium and magnesium phosphate (the so-called bone earth) and 



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