泌尿系结石患者尿液中草酸钙结晶的研究

目的与方法利用扫描电子显微镜(SEM)研究结石患者稀释尿液中，Ca^2 和C2O4^2-浓度、结晶时间和枸橼酸钠对草酸钙结晶的影响。结果Ca^2 和C2O4^2-浓度较高时，热力学不稳定的三水草酸钙(COT)晶体成核及生长的速度比一水草酸钙(COM)晶体快，而随着Ca^2 和C2O4^2-浓度的降低，COM晶体的成核和生长占优势，当浓度降低到0．6mmol／L时，只出现COM这一种晶型。结晶时间有利于COM晶体的生长，COT在结石形成中起着先驱的作用。结论构橼酸钠对草酸钙结晶有抑制作用。

Calcium oxalate crystallization in vitro in the diluted urine of stone-forming individuals

The effects of calcium, oxalate, sodium citrate and crystallization time on calcium oxalate crystal growth were studied in vitro by the observation of crystal morphology grown in the diluted urine of calcium oxalate stone formers using scanning electron microscope. The nucleation and growth of thermodynamically unstable calcium oxalate trihydrate (COT) crystals were faster than those of thermodynamically stable calcium oxalate monohydrate (COM) crystals when the crystallization was in higher concentrations of calcium and oxalate (in the form of potassium oxalate). However, only COM crystals formed when the concentrations of calcium and oxalate declined to 1.60 mmol/L. Longer crystallization time contributes to COM crystal growth; on the contrary COT crystals could be precursors in stone formation which explains why COM was the predominant crystal form rather than COT. Sodium citrate could inhibit crystallization of calcium oxalate.