Hering F, Briellmann T, Lüönd G, Guggenheim H, Seiler H, Rutishauser G
Urol Res. 1987;15(2):67-73. doi: 10.1007/BF00260935.
Microscopic crystals were found by SEM analysis in kidneys of stone forming patients as well as in kidneys of non-stone formers. In most samples calcifications were intratubular in the collecting ducts near the papillary tip. 1-2 micron sized particles lay in a gelatinous substance on the epithelium. The only difference in crystal composition is the higher phosphate content in the kidneys of the non-stone forming group. A correlation between the element concentration of the tissue and the occurrence of microliths is given by the cadmium content of the kidney samples. Both groups showed higher cadmium values in the cortex or medulla when crystals were found in the corresponding papillary samples. Urine supersaturation with respect to calcium oxalate was higher in the stone forming group caused by a higher calcium and oxalate but a lower magnesium excretion.
通过扫描电子显微镜（SEM）分析发现，结石形成患者的肾脏以及非结石形成者的肾脏中均存在微观晶体。在大多数样本中，钙化位于乳头尖端附近集合管的肾小管内。1 - 2微米大小的颗粒位于上皮细胞上的凝胶状物质中。晶体成分的唯一差异在于非结石形成组的肾脏中磷酸盐含量较高。肾脏样本中的镉含量表明了组织元素浓度与微结石发生之间的相关性。当在相应的乳头样本中发现晶体时，两组在皮质或髓质中的镉值均较高。由于结石形成组钙和草酸盐排泄较高但镁排泄较低，其草酸钙的尿液过饱和度更高。
