Carotid plaque instability is not related to quantity but to elemental composition of calcification.

BACKGROUND AND AIMS: Recent studies highlighted the role of calcification processes in the clinical progression of chronic cardiovascular diseases. In this study we investigated the relationship between the chemical composition of calcification and atherosclerotic plaque stability in carotid arteries. METHODS AND RESULTS: To this end, we characterized the calcification on 229 carotid plaques, by morphology, immunohistochemistry, transmission electron microscopy and energy dispersive X-ray microanalysis. Plaques were classified into two categories: unstable and stable. No significant differences were found in the incidence of the various risk factors between patients with and without carotid calcification, with the exception of diabetes. The energy dispersive X-ray microanalysis allowed us to identify two types of calcium salts in the atheromatous plaques, hydroxyapatite (HA) and calcium oxalate (CO). Our results showed that calcification is a common finding in carotid plaques, being present in 77.3% of cases, and the amount of calcium is not a factor of vulnerability. Noteworthy, we observed an association between HA calcification and unstable plaques. On the contrary, CO calcifications were mainly detected in stable plaques. CONCLUSIONS: The presence of different types of calcification in atheromatous plaques may open new perspectives in understanding the molecular mechanisms of atheroma formation and plaque instability.

Assessment of metal contaminants in non-small cell lung cancer by EDX microanalysis.

Human cardio-respiratory diseases are strongly correlated to concentrations of atmospheric elements. Bioaccumulation of heavy metals is strictly monitored, because of its possible toxic effects. In this work, we utilized the EDX microanalysis in order to identify the potential heavy metal accumulation in the lung tissue.  To this aim, we enrolled 45 human lung biopsies: 15 non-small cell lung cancers, 15 lung benign lesions and 15 control biopsies. Lung samples were both paraffin embedded for light microscopy study and eponepoxid embedded for transmission electron microscopy. EDX microanalysis was performed on 100 nm thick unstained ultrathin-sections placed on specific copper grids. Our results demonstrated that the EDX technology was particularly efficient in the study of elemental composition of lung tissues, where we found heavy metals, such as Cobalt (Co), Chromium (Cr), Manganese (Mn) and Lead (Pb). Furthermore, in malignant lesions we demonstrated the presence of multiple bio-accumulated elements. In fact, a high rate of lung cancers was associated with the presence of 3 or more bio-accumulated elements compared to benign lesions and control tissue (91.7%, 0%, 8.3%, respectively). The environmental impact on pulmonary carcinogenesis could be better clarified by demonstrating the presence of polluting agents in lung tissues. The application of EDX microanalysis on biological tissuescould shed new light in the study of the possible bioaccumulation of polluting agents in different human organs and systems.