Dissertações em Neurociências e Biologia Celular (Mestrado) - PPGNBC/ICB
URI Permanente para esta coleçãohttps://repositorio.ufpa.br/handle/2011/2375
O Mestrado Acadêmico pertence ao Programa de Pós-Graduação em Neurociências e Biologia Celular (PPGNBC) do Instituto de Ciências Biológicas (ICB) da Universidade Federal do Pará (UFPA).
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Item Acesso aberto (Open Access) Avaliação eletrorretinográfica de ratos wistar jovens submetidos à tireoidectomia bilateral(Universidade Federal do Pará, 2012-10-31) RODRIGUES, Keuri Eleutério; ROCHA, Fernando Allan de Farias; http://lattes.cnpq.br/3882851981484245The thyroid synthesizes thyroxine (T4) and 3,5,3 '-triiodothyronine (T3), both hormones have a crucial role in the development of the central nervous system, including the retina and visual system. The decrease in blood levels of T3 and T4 causes a syndrome called hypothyroidism, which may lead to visual impairment. The visual deficits generated by hypothyroidism are directly related to the development period of the individual. It has been demonstrated in murine models that congenital hypothyroidism decreases the retinal thickness, the number of cells and interferes with the differentiation of M cones. Here, we investigated the possible functional changes in juvenile rat’s retina after bilateral thyroidectomy using noninvasive electrophysiological responses. Therefore, we divided the rats into three groups (control, sham and thyreoidectomized) each containing n≥8 animals. The surgeries were performed 30 days post-natal and the full-field electroretinogram (ERG) were performed 10, 15, 20, 25 and 30 days after surgery, using standard protocols for assessing the scotopic response maximum, photopic response (with and without the use of light filters) and response to flicker (12, 15, 18 and 30 Hz). The parameters analyzed were implicit time and amplitude of a- and b-waves of ERG. We also perform monitoring of clinical parameters of animals in order to identify characteristics that indicate a hypothyroidism, as well as the dosage of thyroid hormones. The results showed that there was a decrease in the a- and b-waves amplitudes in thyroidectomy animals (10, 15, 20, 25 and 30 days after surgery), compared to control and sham animals at all the stimulation protocols used in ERG. The results of the evaluation of the implicit time for both waves showed none statistical difference when comparing to control and sham groups. Also we observed a reduction in size and weight of thyroidectomy animals, associated with reduced levels of thyroid hormone (T3). Thus we concluded that the thyroid hormones are directly related to functional changes in the retina of thyroidectomy animals, together with the reduction of weight and size.Item Acesso aberto (Open Access) Correlação entre parâmetros estimados pelos testes Colour Assessment and Diagnosis e Cambridge Colour Test na avaliação da discriminação de cores(Universidade Federal do Pará, 2015-03-31) FARIAS, Letícia Miquilini de Arruda; SOUZA, Givago da Silva; http://lattes.cnpq.br/5705421011644718The Colour Assessment and Diagnosis (CAD) and Cambridge Colour Test (CCT) tests are widely used in basic and clinic researches, because of high sensibility and specificity of your results. These tests use distinct paradigms of stimulation to estimate the color discrimination thresholds. It is not well known about the relationship of results of each paradigm in the evaluation of color discrimination in these tests. So, the present study aimed to compare the parameters of evaluation of color discrimination estimated from CAD and CCT tests. Fifty-nine trichromat subjects and thirty eight subjects with congenital dyschromatopsia (16 protans, 22 deutans) with mean age of 26,32 ±8,9 years-old were evaluated. 66 subjects were tested in CAD and CCT tests, 29 subjects in the CAD test and 2 subjects in the CCT test. The color vision phenotype of all subjects was determined through a battery of psychophysical tests and the estimative of color discrimination thresholds was evaluated by CAD and CCT tests. The data of color discrimination thresholds was fitted ellipses. The criteria analyzed to each subject were: area of the ellipses, angle of rotation of the ellipses and size of protan, deutan and tritan vectors. For each one of parameters was realized: descriptive statistic, analysis of dispersion of parameters between CAD e CCT tests and the combination of these parameters in each test, ratio between the parameters, correlation of parameters to three mathematical models and analysis of agreement. The parameters of area and size of deutan and tritan vectors of trichromat subgroup, area and size of tritan vector of protan subgroup, and size of protan and tritan vectors of deutan subgroup exhibited equivalence between the results of both tests. The parameters of area, angle of rotation and size of protan and tritan vectors showed agreement of measures between your results. Factors as the distincts localizations of neutral points of CAD and CCT tests and the spatial arrangement of the vectors in the CIE 1976 color space in the CCT test may have influenced the determination of chromatic discrimination thresholds of both tests. Despite using distinct paradigms in configuration of stimulation, the tests CAD and CCT are comparable.Item Acesso aberto (Open Access) Estudo da neuropatologia induzida pelo vírus Marabá em modelo murino(Universidade Federal do Pará, 2014-02-28) FARIAS, Alexandre Maia de; DINIZ, Cristovam Wanderley Picanço; http://lattes.cnpq.br/2014918752636286; DINIZ JUNIOR, José Antônio Picanço; http://lattes.cnpq.br/3850460442622655The Marabá virus (Be AR 411459) is an Vesiculovirus (VSV), member of the Rhabdoviridae family, isolated in 1983 from a pool of sandflies captured in Marabá - PA by Section Arbovirus the Evandro Chagas Institute. In literature There are few studies on experimental neuropathology Marabá virus induced, despite 30 years of isolation. A single study, however, revealed that viral infection in newborn mice causes necrosis and pyknosis in neurons in several regions of the central nervous system (CNS). The objective of this study was to investigate the distribution of Marabá virus in the CNS, reactive microglia and astrocytes, histopathologic features, and the expression of cytokines and nitric oxide (NO), in Marabá virus-induced encephalitis in BALB / c mice. Thus was performed processing of samples for histopathological examination; Immunohistochemistry for observation of microglia, astrocytes and viral antigen; tests for quantification of cytokines and NO, and statistical analyzes. The results showed that infected animals (Ai) 3 days after inoculation (d.p.i.) with discrete labeling of viral antigen, as well as the activation of microglia and astrocytes in the CNS. Moreover , in Ai 6 d.p.i. marking the viral antigen was observed in almost all brain regions, with intense microglial activation in these locations, although was less astrogliosis. Edema, necrosis and apoptosis of neurons were mainly observed in the olfactory bulb, septum and frontal cortex of Ai 6 d.p.i. Quantification of IL - 12p40, IL- 10, IL- 6, TNF- α, INF- ү, MCP-1 and NO, showed significant increases in Ai 6 d.p.i., when compared with controls animals and Ai 3 d.p.i. On the other hand, TGF-β, important immunosuppressant, has not been significant in all groups and evaluated times (3 and 6 d.p.i.). These results indicate that Marabá virus can infect various CNS regions of BALB /c mouse adult 6 d.p.i., producing anatomical and pathological changes and strong inflammatory immune response that can be lethal to the animal.