| Abstract: By means of nanoparticle size analyzer and transmission electron microscopy (TEM), the effect of membrane pore size on the properties of crystallites in urine of 10 lithogenic patients and 10 healthy subjects were comparatively investigated after urines were filtrated through microporous membrane with a size of 0.22, 0.45, 1.2, 3.0, 10 μm, respectively. These properties include average particle size (d), size distribution, intensity-autocorrelation curve, ζ potential and aggregation state. With the increase of pore size from 0.22 μm to 10 μm, d value of the urinary crystallites in urine of lithogenic patients increased from 162 nm to 3 227 nm, the autocorrelation time (Ta) increased from 1.92 ms to 2 100 ms, the average value of ζ decreased from -2.65 mV to -9.21 mV, respectively; and the autocorrelation curves were of fluctuating and unsmooth, TEM showed that the size difference of the crystallites was large and some crystallites were in the aggregation state. However, for the crystallites in urine of healthy subjects, d increased only from 187 nm to 1010 nm, Ta increased from 1.40 ms to 6.67 ms, the average value of ζ decreased from -5.22 mV to -6.89 mV, the autocorrelation curves were of regular and smooth, TEM showed that the crystallites were well-dispersed with a smaller size. The above results demonstrated that the urinary system of lithogenic patients is unstable and the aggregation degree of their urinary ctystalllites is high. So the risk of urolithiasis formation of urinary crystallites of patients is larger than that of healthy subjects. |
