== Comparison of XRD patterns intended for AP sample number 6 (curve 1) and the nanosized synthetic HAp (curve 2) taken in the same experimental conditions

== Comparison of XRD patterns intended for AP sample number 6 (curve 1) and the nanosized synthetic HAp (curve 2) taken in the same experimental conditions. The intensity (the ratio signal-to-noise) of XRD patterns varies significantly (two orders of magnitude) with sample but the quantitative estimation of amount of HAp in the investigated species is a quite tricky task and is not done in the present research. Table 1demonstrates that you cannot distinguish stable AP from the unstable one from the area occupied by calcium deposits. 1 . Introduction == Atherosclerosis is a cardiovascular disease characterized by the accumulation of fatty deposits within the arterial intima, which can eventually expand into the lumen and obstruct blood flow. Atherosclerosis is the result of chronic inflammation in the arterial vessels, initiated by endothelial cells damage, involving monocytes, macrophages, and dendritic cells in conditions of oxidative stress. It is a slowly progressive multifactorial disease with a long asymptomatic phase [1]. Aortic arch atherosclerosis (especially in the common carotid artery bifurcation) is the cause of 20% of ischemic stroke [2, 3], which is the consequence of the increasing atherosclerotic plaque (AP) instability. Plaque stability becomes critical because atherosclerosis progresses. Rupture of unstable plaque can initiate thrombosis leading to vascular occlusion and downstream tissue infarction. One of the important components in the pathogenesis of atherosclerosis is an AP calcification [4, 5]. The origin and mechanisms from the AP calcification remain unclear. Calcification initially affects the lipid core in the close vicinity to the cells involved in the inflammation [4]. Apoptotic bodies and cell Ethyl ferulate debris act as nucleation centers intended for the accumulation of lipoproteins and phospholipids [3] with the deposition of biominerals, consisting mainly from the nonstoichiometric, calcium-deficient carbonated hydroxyapatite (HAp) with the chemical formulae Ca10(PO4)6(CO3)2for ideal HAp [47]. At present, there is no consensus in the expert community on whether the calcification is a sign (indicator) from the AP stability. It is logical to assume that the status of the AP organomineral matrix should (or may) mirror the status Ethyl ferulate of the AP stability but different aspects of calcifications Ethyl ferulate must be taken into account to establish a significant relationship with the AP progress. Rabbit Polyclonal to GPR126 These include chemical diversity, morphologic features at the mesoscopic and macroscopic scale, location, presence of trace elements, presence of molecular groups, such as carbonate groups in apatites [6, 8]. It, in its turn, implies Ethyl ferulate the comprehensive analysis of the clinical and reference materials by the variety of the analytical methods, some of which are still not widely implemented not only into the clinical practice but even into the advanced biochemical research. Because HAp is a highly absorptive material [911], it is believed that this biomineral in AP would actively absorb metal complexes located in the tissue matrix as the result of release from normal or destructive cells of the vessel wall. Among those are the complexes of Fe, Cu, and Mn, many of which are paramagnetic and, therefore , can be detected and investigated by electron Ethyl ferulate paramagnetic (spin) resonance (EPR or ESR) methods (see [12, 13] and literature cited there). The type of the noticed EPR spectra, their intensity, relaxation characteristics, and so forth reflect the structure and properties of the sponsor matrix; that is, the noticed paramagnetic complexes can serve as intrinsic probes that mirror the origin, growth, and status from the AP biominerals as well as a status of the surrounding tissues. Regarding manganese, in the human body, Mn exists primarily in two oxidized says, that is, Mn2+and Mn3+. While Mn3+species are generally EPR silent, Mn2+complexes are EPR detectable [14]. The most familiar manganese-containing complex is a manganese superoxide dismutase (Mn-SOD). It is a homotetramer (96 KDa) that contains one manganese atom per subunit that cycles from Mn3+to Mn2+and back to Mn3+during the two-step dismutation of superoxide. It is the primary enzyme of the antioxidant defense.