Mapeamento de elementos de baixo número atômico em tecidos cardíacos de ratos usando microfluorescência de raios X com excitação síncrotron de baixa energia (LEXRF)

• Autor(a) principal: Silva, Andrea Mantuano Coelho da
• Data de Publicação: 2016
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/12857
• topic: Low-Z elements micro-X-ray fluorescence; Myocardial; Cardiac tissue; Aortic; Micro fluorescência de raios X de elementos de baixo número atômico; Miocárdio; Tecido cardíaco. Aorta; CNPQ::CIENCIAS EXATAS E DA TERRA::FISICA::FISICA DA MATERIA CONDENSADA

Data from Global Cancer Statistics show that breast cancer (BC) is the most common type of cancer among women, leading the number of deaths caused by cancer. The developments in diagnosis and treatment techniques for the BC, which include chemotherapy and/or radiotherapy, increased the survival rates for this type of cancer. One late complication induced by BC treatment is the cardiotoxicity. The cardiotoxicity term comprises different cardiotoxic side effects, which includes arrhythmia, blood pressure alterations, myocardial ischemia, thrombosis, congestive heart failure and aortic damages. This study aimed to evaluate the cardiac alterations induced by radiotherapy and chemotherapy, simulating a treatment for BC in Wistar rats. It is, therefore, important to understand the mechanisms involved in the cardiotoxicity, in order to prevent women from this late effect, when they undergo BC treatments. The major interests in this work are in Low atomic weight elements as Magnesium (Mg), because it is important in the cardiac metabolism; Iron (Fe), because BC treatment induced cardiotoxicity can be associated to the oxidative stress;and other Sodium (Na) because it is strongly related to cardiomyocyte contraction.Changes that occur in unhealthy tissues, for example, in case to cardiovascular damages, can be better understood when elemental compounds and structures of healthy tissues are known. Low Energy X-ray Fluorescence LEXRF technique was used to obtainelemental maps of low Z-elements providing a semi-quantitative analysis of the different tissues evaluated under the same conditions. Through the technique LEXRF we obtained elemental maps, absorption, and maps of attenuation mass coefficients for the primary energy and all fluorescents energies. The results showed that wen the tissue receive chemotherapy and/or radiotherapy their structures were changed and consequently some elemental compounds become altered. The results that showed more damages were when associate chemotherapy and radiotherapy in comparison to myocardium and aortic healthies. For myocardium tissues the results showed low intensities of Na and high intensities of Mg. For the same group, aortic showed low intensities of Na and Mg. In this work, were also calculated the linear attenuation coefficients and mass lower energies than 1keV in both tissues, hitherto unknown in the literature. All intensity maps were normalized by Compton peak intensity. LEXRF was carried out at TwinMic beamline in the ELETTRA Synchrotron Facility, at the beamline TwinMic, in Trieste, Italy.