Thermodynamic modeling of crystal deposition in humans

The prevention and treatment of crystal deposition in the human body are ba sed on the understanding of the physicochemical properties underlying the p recipitation of the substances involved. Among these properties, the solubi lities of the crystals are very important. Recently, experimentally determi ned solubility data of substances related to urolithiasis, such as calcium oxalate hydrates, uric acid and urates, cystine, and xanthine, were critica lly assessed. Unfortunately, reported solubilities of these substances were found to be either scarce or in large disagreement. Consequently, detailed studies were carried out in our laboratory, and the results will be discus sed in this communication with emphasis on the thermodynamic consistency of the experimentally determined data. Since proper modeling of the solubilit ies of these substances in artificial urine solutions serves as a prerequis ite for solubility predictions in real urine, the Joint Expert Speciation S ystem (JESS) software package was employed to create a comprehensive comput er model including the relevant, low-molecular inorganic and organic compon ents of urine. The results of the simulations lead to some useful suggestio ns regarding the prevention and treatment of stone disease.