Análise de tecido mamário neoplásico canino a partir da técnica de difração de Raios X

Abstract

Canine mammary neoplasms represent approximately 52 % of all neoplasms that affect females of this species. Currently studies with human mammary tumors have shown that the use of X-ray diffraction technique allows the identification and differentiation of molecular structures of tissues. However, few studies have used this technique to study canine mammary carcinogenesis. In order to identify alterations in the molecular structures of healthy canine mammary tissues 101 samples distributed among 26 normal tissues, 33 malignant neoplastic tissues and 42 benign neoplastic tissues preserved in 10% formaldehyde, with reports prescribed by specialists, were submitted to a diffraction technique. The samples were irradiated by the SHIMADZU XRD 7000 powder-specific X-ray diffractometer composed of an X-ray anode of Cu with an energy of Kα= 8.04 keV, used in the reflection mode. The angles of incidence of the photons on the sample ranged from 3° to 37° and, with in this angular variation the beams scattered around the sample were detected in steps of a third of degree with a time of counting of 20 seconds. In order to correct the scattering profile provided by the equipment software and to allow the identification of alterations at the molecular level of the tissues submitted to the technique, correction factors associated to the experimental arrangement were calculated. After corrections for each group of samples, were obtained and molecular changes were identified by the peak positions and relative intensity of the peaks. The findings of this work presented similarities to those found in the literature for humans thus suggesting the possibility for ussing canine tissue as a model for diagnostic and therapy studies. This technique applied to canine neoplasias presents a potential for the study of the woman's breast cancer.