尿液中纳米微晶的团聚促进泌尿系结石的形成

采用纳米粒度仪和透射电子显微镜(TEM)比较研究了尿石症患者与健康对照者尿液中纳米微晶的尺寸、粒度分布、聚集状态、自相关函数和ξ电位随放置时间的变化. 患者尿样放置3 h后, 其尿微晶平均粒径(D_a)由506 nm增至958 nm, 粒度分布范围变宽, 自相关时间由1.84 s延长到3.93 s, ξ电位由-1.34 mV降低至-3.89 mV; 而健康对照者尿微晶的D_a仅由330 nm增加至416 nm, 自相关时间由1.44 s延长至2.10 s, ξ电位由-8.35 mV降低至-8.90 mV. 此结果表明, 尿石症患者和健康对照者尿液中的纳米微晶不但在尺寸、粒度分布、聚集、自相关函数和ξ电位等方面存在明显的差异, 而且患者尿微晶的稳定性比对照者的差; 随着时间的延长, 患者尿液中的纳米微晶会逐渐团聚, 而对照者尿微晶的团聚要轻微得多. 从两类尿液中尿大分子和小分子抑制剂的浓度、尿微晶表面形成双电层的稳定性等方面进行了分析, 结果表明, 尿微晶的聚集是泌尿系结石生长的关键因素.

Aggregation of Urine Crystallites to Accelerate Formation of Urolithiasis

The variation of particle size, size distribution, aggregation state, intensity-autocorrelation function and ξ potential of the nanocrystallites in urine of lithogenic patients and healthy subjects following the placement time were comparatively investigated by nanoparticle size analyzer and transmission electron microscopy(TEM). As the placement period increased from 0 h to 3 h, the average diameter(Da) increased from 506 nm to 958 nm. The size distribution of particles became much wider, the autocorrelation time increased from 1.84 s to 3.93 s, and the ξ potential was decreased from -1.34 mV to -3.89 mV. However, Da in healthy urine increased only from 330 nm to 416 nm, the autocorrelation time increased from 1.44 s to 2.10 s, and the ξ potential was decreased from -8.35 mV to -8.90 mV. When the above process was repeated after these two types of urine samples received the second ultrasound treatment, all properties of urinary nanocrystallites basically repeated the above variation rules. It indicated that the nanocrystallites in the urine of lithogenic patients not only was distinctly different from those of healthy patients in particle size, size distribution, aggregation state, intensity-autocorrelation function and ξ potential, etc., but also had lower stability; the nanocrystallites in lithogenic urine can gradually agglomerate with the prolongation of placement period. These results are explained from the concentration difference between inhibitors with large and small molecules in the two types of urine, the stability of electric double layer formed on the surface of urinary nanocrystallites, etc. The results show that the aggregation of urinary nanocrystallites is the key factor to stone placement.