Chemolysis of artificial cystine stones (BON(N)-STONES) in vitro using a new dissolution device: first results.
OBJECTIVE
The treatment of cystine stones is a clinical problem. This in vitro study was performed to establish an experimental system that enables standardized and reproducible investigations on chemolysis of cystine stones to look for an improvement of dissolution strategies.


METHODS
Artificial spherical stones made of cystine (BON(N)-STONES) with a diameter of 0.9 cm were used. A new dissolution device was developed simulating the physiological conditions in the upper urinary tract with computer-assisted online measurement of data. For chemolysis of artificial cystine stones, different solvents (artificial urine, physiologic sodium chloride solution, 2 % acetylcysteine, 8.4 % sodium bicarbonate solution, THAM, and combinations) were used.


RESULTS
Chemolysis is an effective tool in the management of cystine stone disease. Statistical analysis showed significant differences (p < or = 0.05) for all solutions compared with artificial urine alone. A combination of THAM at pH 10 with acetylcysteine (2%) showed a 48-fold stronger ability to dissolve cystine calculi than did artificial urine.


CONCLUSIONS
By performing standardized in vitro investigations, new basics to improve the dissolution of cystine stones have been developed. It is recommended to use artificial stones made of cystine and a dissolution device simulating physiological conditions for investigations on chemolysis in the future.
Jacobs
D
D
Department of Urology, University of Bonn, Germany.
Heimbach
D
D
Müller
S C
SC
Hesse
A
A
D000111:Acetylcysteine / Q000627:therapeutic use; D003553:Cystine / Q000378:metabolism*; D004338:Drug Combinations; D004867:Equipment Design; D006801:Humans; D066298:In Vitro Techniques; D008954:Models, Biological; D012997:Solvents / Q000627:therapeutic use*; D014325:Tromethamine / Q000627:therapeutic use; D014545:Urinary Calculi / Q000188:drug therapy* / Q000378:metabolism*; D014556:Urine
D004338:Drug Combinations; D012997:Solvents; D014325:Tromethamine; D003553:Cystine; D000111:Acetylcysteine