Biological rhythmicity and crystallization--urine profiles and Se-studies on calcium oxalate stone genesis.

In profile urines from oxalate stone patients and normal persons the progress of concentration and excretion of 10 urine parameters was investigated. For the majority of lithogenic and litholytic urine substances, especially for oxalic acid, a day-and-night rhythm was proven. This may be transferred to a principle of zonary structure of weddellite crystals, explaining the periodically recurring change of weddellite layers of different dissolution resistances arising from different growth rates due to different concentrations of supersaturated urine.