Benedicto de Campos Vidal

Learn More
I review here form, or textural, birefringence (Δ(F)) in the context of advances in the field, as well as with regard to findings and applications in the physics of photonic devices, fibers maintaining polarization, photonic crystal fibers, and in biopolymers present in extracellular matrices and the myelin sheath. Some advantages of applying knowledge of(More)
Violacein, a pigment produced by Chromobacterium violaceum, is reported to be a potential drug for the treatment of Chagas' disease. Violacein is also effective against leukemia and lymphoma cells in culture (IC50 10−8 M). Changes in the nuclear acid content, 3-(4,5-dimethylthiazole-2-yl)-2,5-biphenyl tetrazolium bromide reduction and neutral red uptake in(More)
To determine whether collagen solubilized from tendons can regenerate the most relevant characteristics of the tendon supraorganization was the aim of the present study. Extracted and purified collagen in acetic acid solutions subjected to precipitation and extensive dialysis was found to produce gels with rheological properties that allowed them to form(More)
Chromatin supraorganization and extensibility and nuclear glycoprotein content have been reported to change in hepatocytes from mice during development and aging, as well as under starvation and refeeding conditions. In non-obese diabetic (NOD) mice, the expression of insulin-dependent diabetes may be accompanied by metabolic changes in the liver. These(More)
This work describes polyploidy characteristics and nuclear phenotypes with advancing age in salivary glands of the rat. Feulgen-stained nuclei from squashed salivary gland fragments and nuclei isolated from homogenized salivary glands were analyzed with automatic scanning cytophotometry using Zeiss equipment and a Microdata computer. Polyploidy was(More)
The fate of RNA revealed by metachromatic staining after a critical electrolyte concentration assay using toluidine blue and Mg(2+)ions as competitors for the substrate dye binding sites was followed at mitosis in human breast epithelial cells transformed by benzo[a]pyrene and transfected with the c-Ha- ras oncogene. The aim was to detect changes in RNA(More)
For the purpose of determining the changes in tensile strength and levels of macromolecular orientation in collagen bundles as a result of mechanical stimuli, rats were submitted to different experimental treatments such as physical exercise and muscular denervation. After these treatments the Achilles tendons of the animals were submitted to biomechanical(More)
The dichroism on tendons stained with Toluidine Blue was investigated under conditions which reveal metachromasy. The spectral curves of the dichroism were determined by histophotometry and showed maxima of light absorption at different wavelengths, according to the fiber direction with respect to the plan of polarized light. The results were discussed in(More)