Cristallographic and pathologic study of calcified atheroma

Abstract

The objective of this study was to identify the mineral phases present in calcified atheromatous aortas. The following techniques were used: 1) Optic microscopy in order to find the crystalline masses. 2) Scanning electron microscopy. 3) X-ray difraction in order to identify the mineral phases present. 4) X-ray dispersion analysis to confirm the chemical composition and to determine the relationship Ca/P: A) The relationship Ca/P indicates the presence of carbonate ions, replacing phosphate ions, in the calcium phosphate structure. The results of the X-ray diffraction indicate that the mineral present in the studied calcifications belong to the calcium-hydroxiapatites family, its general formula being CA₁₀ (PO₄)₆ (OH)₂ B) It is worth mentioning that EDAX analysis of the small spherulites showed the presence of chlorine and calcium ions and only a low concentration of phosphate ions. The results show that, apart from the calcifications that appear in the form of carbonate-hydroxiapatite, other type of calcifications may be present whose main components are chlorine and calcium with a very low phosphorus concentration, S, Si, Al and Na. The X-ray energy dispersive analysis is an unreplaceable method for this type of information with very small samples. On the other hand, it pointed out the usefulness and importance of high technology cristallographic techniques in the study of aortic calcified atheroma showing the variety that can be found in the apatites present in biological tissues, as shown by the presence of Cl^- or CO₃ = in the hydroxiapatite structure.