Structural and chemical characterization of inorganic deposits in calcified human mitral valve.
Structural and chemical characterization of inorganic deposits in calcified human mitral valve.
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DOI：
10.1016/0162-0134(88)85019-0
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发表时间：
1988-10
影响因子：
3.9
通讯作者：
A. Bigi;E. Foresti;A. Ripamonti;L. Compostella;A. Fichera;Massimo Gazzano;N. Roveri
中科院分区：
文献类型：
--
作者：
A. Bigi;E. Foresti;A. Ripamonti;L. Compostella;A. Fichera;Massimo Gazzano;N. Roveri
X射线衍射仪，IR。对钙化的人二尖瓣和戊二醛保存的猪主动脉移植物的矿物质沉积物进行了吸附、化学分析。从高度钙化的二尖瓣和猪主动脉移植物中分离出的矿物沉积物由B型碳酸盐磷灰石组成。在钙化程度较低的二尖瓣的灰烬中，存在镁取代的β-磷酸三钙，以及类似于达利石的磷灰石相。比较了镁掺杂引起的β-磷酸三钙晶胞收缩和合成β-磷酸三钙在不同镁取代度下晶格常数的变化。这些结果揭示了镁在人体瓣膜钙化中的重要作用。事实上，在钙化过程开始时沉积的磷灰石相，当镁含量较高时，通过1000℃的热处理完全转化为β-磷酸三钙；另一方面，当钙化变得块状时，镁含量显得非常低，沉积的磷灰石相具有很高的热稳定性。
X-ray diffraction, i.r. absorption, and chemical analyses have been carried out on the mineral deposits of calcified human mitral valves and glutaraldehyde-preserved porcine aortic grafts. The mineral deposits isolated from highly calcified mitral valves and porcine aortic grafts are constituted of type B-carbonate apatite. Magnesium substituted β-tricalcium phosphate is present, together with an apatitic phase similar to dahllite, in the ashes of poorly calcified mitral valves. The contraction of the unit cell of β-tricalcium phosphate due to magnesium incorporation is compared with the variation of the lattice constants of synthetic β-tricalcium phosphate at different degree of magnesium substitution for calcium. The results reveal the important role of magnesium on the calcification of human valves. In fact, the apatitic phase deposited at the beginning of the calcification process, when there is a high magnesium content, converts completely into β-tricalcium phosphate by heat treatment at 1,000°C. On the other hand, when the calcification becomes massive, magnesium content appears highly reduced, and the deposited apatitic phase is characterized by a high thermal stability.