Aggregation of Urinary Microcrystallines with Different Sizes

Changes of average size ( d ), autocorrelation curve, aggregation state and stability of urinary crystallites in urine samples of calcium oxalate (CaOxa) stone patients and healthy controls with placement time were com- paratively studied using transmission electron microscopy (TEM) and nanoparticle size analyzer. The urine samples were filtrated by microporous membrane with a pore size of 0.22, 0.45, 1.2 and 3 μm, respectively. With the in- crease of placement time from 0 to 4 h, the d values of the crystallites in various filtrated urine of patients in- creased rapidly. The amplification of d (Δ d ) was 1439, 1557, 1534 and 1051 nm, respectively, when the place- ment time was up to 4 h. However, the Δ d of the urine crystallites of the controls was relatively small, which was only 474, 511, 567 and 433 nm, respectively. The urinary crystallites of the patients had rapid and large agglomera- tion and poor stability compared with those of the controls. The urinary crystallites of small size agglomerated more easily than those of large size. The results show that the rapid agglomeration of urine crystallites may play an im- portant role in the formation of CaOxa stones.