Comparative investigations of ultrafine crystals in urine of healthy human and lithogenic patients

The ultrafine crystals in urine of lithogenic patients and healthy human were investigated by transmission electron microscopy (TEM), selected-area electron diffraction (SAED), X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopy. Phosphates and calcium oxalate monohydrate (COM) were present in urine of both healthy human and lithogenic patients. In urine of healthy human, the ultrafine crystals were well dispersed and more rounded, their size was smaller. However, the ultrafine crystals in lithogenic urine were highly aggregated. These results were explained by the difference of the concentration and activity of urinary inhibitors. The inhibitors in healthy urine have strong ability to inhibit the growth and aggregation of urinary crystals, making the edges and tips of these crystals more rounded.