Chapters authored
Nonlinear Microscopy Techniques: Principles and Biomedical Applications
Nonlinear optical microscopy techniques have emerged as a set of successful tools within the biomedical research field. These techniques have been successfully used to study autofluorescence signals in living tissues, structural protein arrays, and to reveal the presence of lipid bodies inside the tissular volume. In the first section, the nonlinear contrast technique foundations is described, and also, a practical approach about how to build and combine this setup on a single confocal system platform shall be provided. In the next section, examples of the usefulness of these approaches to detect early changes associated with the progression of different epithelial and connective tissular diseases are presented.
Part of the book: Microscopy and Analysis
Genotoxicity Induced by Cypermethrin in the Zebrafish Retina
Cypermethrin (Cyp), is one of the most common contaminants in freshwater aquatic systems. We evaluated its possible genotoxic effect and oxidative stress in retinal cells of adult zebrafish exposed to 0.3 μg/L and 0.6 μg/L Cyp. Both the histological and immunofluorescence (IF) techniques showed the presence of apoptotic cells in the zebrafish retina after 9 days of treatment with 0.6 μg/L Cyp. Thus, histone γ-H2AX, a double-stranded DNA damage marker, was immunodetected in both the outer and inner nuclear layer after exposure to 0.6 μg/L Cyp for 12 days, while the anti-caspase-3 apoptotic antibody was detected in the outer nuclear layer. Compared with the morphological evidence, the damage index (DI) showed significant differences with 0.3 μg/L from day 9, while with 0.6 μg/L all the stages evaluated showed very significant differences. According to these results, it was verified that the activities of superoxide dismutase (SOD) and catalase (CAT) increased significantly after exposure to 0.6 μg/L Cyp. The same treatment caused a significant positive regulation of the mRNA levels of both genes. These results indicate that Cyp causes DNA damage and oxidative stress. This pyrethroid also has the potential to induce apoptosis in the cells of the retina.
Part of the book: Genotoxicity