Calcium phosphate calcium oxalate crystal association in urinary stones: Implications for heterogeneous nucleation of calcium oxalate
Calcium phosphate calcium oxalate crystal association in urinary stones: Implications for heterogeneous nucleation of calcium oxalate
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DOI：
10.1016/s0022-5347(01)65381-3
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发表时间：
1997-01-01
影响因子：
6.6
通讯作者：
Khan, SR
中科院分区：
文献类型：
--
作者：
Khan, SR
目的：大多数结石含有不止一种类型的晶体，一些组合，如磷酸钙/草酸钙，比其他组合更常见。晶体之间的外延被认为在这种石头的生长中起到了作用。本研究的具体目的是探讨磷酸钙在草酸钙结晶过程中的作用。材料和方法：对20个草酸钙结石或结石碎片进行扫描、透射和背散射电子显微镜观察。类似地，实验大鼠尿囊内植入的塑料异物诱导草酸钙结石也被研究。结果：在人和大鼠的结石中，磷酸钙和草酸钙晶体之间存在紧密的缔合关系。所有被检查的晶体都与表面的有机基质有关，并在晶体实体中含有大量的有机物质。晶体之间的界面似乎也被有机基质占据。结论：本研究和我们实验室的其他研究结果表明，尽管从理论上讲，各种晶体之间的外延似乎不太可能在体内发生。结石中特定的结晶组合的出现可能是尿路环境有利于这些成分结晶的结果。草酸钙的异相成核很可能是由生物因素引起的，包括膜细胞降解产物。
Purpose: Most stones contain more than one type of crystals, and some combinations, such as calcium phosphate/calcium oxalate, are more common than others. Epitaxy between the crystals has been suggested to play a role in growth of such stones. The specific aim of this study is to investigate the involvement of calcium phosphate in crystallization of calcium oxalate.Materials and Methods: Twenty calcium oxalate stones or stone fragments were examined using various microscopic techniques, including scanning, transmission and back-scattered electron microscopy. Similarly, calcium oxalate stones induced on a plastic foreign body implanted inside urinary bladders of laboratory rats were also investigated. Examination of the interface between calcium phosphate and calcium oxalate crystals was emphasized.Results: Close association between crystals of calcium phosphate and calcium oxalate were found in both the human and rat stones. All crystals examined were associated with an organic matrix on the surface and contained copious amounts of organic material within the crystalline entities. Interface between the crystals also appeared to be occupied by organic matrix.Conclusions: Results of this and other studies from our laboratory indicate that epitaxy between various crystals, even though theoretically possible, appears unlikely in vivo. The appearance of specific crystalline combinations in stones is probably a result of the urinary environment being conducive for crystallization of those components. Heterogeneous nucleation of calcium oxalate is most probably induced by biological elements, including membranous cellular degradation products.