Mestrado em Bioquímica

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http://repositorio.ufes.br/handle/10/17562

Nível: Mestrado Acadêmico
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Navegando Mestrado em Bioquímica por Autor "Bittencourt, Athelson Stefanon"

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    Coloração de espécimes anatômicos para aplicação no processo de plastinação por meio de corantes histológicos : floxina b, safranina, fucsina fenicada e tricrômico de masson
    (Universidade Federal do Espírito Santo, 2018-09-17) Siqueira, Bruno Magela de Melo; Bittencourt, Ana Paula Santana de Vasconcellos; Bittencourt, Athelson Stefanon; Silva, André Romero da; Ribeiro, Joselito Nardy
    The Study of Anatomy has been known for several centuries and before this, every moment has generated several repercussions in this area of biomedical sciences. Even with advancement in the technological sectors, the teaching of anatomical concepts through corpses in health courses is still essential. A more common way of preserving anatomical parts for studies is through a substance that was discovered in 1867 by German Hoffman by accident: formaldehyde, but such substance has an unpleasant odor and irritates the nasal passages and the eye region. Plastination is the newest in terms of technology for the preservation of anatomical specimens. This technique was developed by the German Dr. von Hagens in 1977 and its principles reflect in the idea of impregnating polymers (silicone, epoxy or polyester) in biological tissues, removing the fat and water present, thus increasing their durability and with aspects close to the original object. Plastination is free from toxic conservative substances, thus facilitating its role for didactic and scientific purposes. The dye is used for a better visualization of the structures in the anatomical part and thus ending with that aspect of worn, emphasizing the true color of the object. In view of the above, has developed a staining protocol in skeletal muscle tissue, applied to the Plastination technique with the following dyes: Phloxine B, Safranin, Phenicated Fuchsin and Masson's Trichrome. The interaction of the dye with the muscle tissue, fat and epithelial tissue of the samples that were used for the research was evaluated. All the dyes used in the macroscopic staining were able to show certain structures such as tendon, fascia and connective tissue inside the muscle. It was also evaluated the photodegradation of these dyes in solution. It was noticed that the dyes that obtained more satisfactory results in relation to the dyeing of the specimens were those of anionic character: Phloxine B and Masson's Trichrome, but in relation to the resistance of the dyes in light exposure, it was not possible to choose the one that obtained the best because the solutions exhibited different behaviors when exposed to light. The final protocol for the staining muscle tissues will be applied in the collection of the Life Sciences Museum of the Federal University of Espírito Santo and in the Department of Morphology of the same University.
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    Efeito de diferentes agonistas de receptores galaninérgicos no núcleo dorsal da rafe de ratos expostos a modelos animais de ansiedade e pânico
    (Universidade Federal do Espírito Santo, 2015-02-26) Morais, Juliana da Silva; Harres, Vanessa Beijamini; Bittencourt, Athelson Stefanon; Andreatini, Roberto
    Galanin (GAL) is a peptide present in the CNS of various mammals, including human being. Three different receptors have been cloned for the GAL, GALR1 and GALR3, inhibitory, and GALR2, excitatory. The distribution of GAL in structures involved in the control of emotions, and behavior studies suggest that GAL may be involved in the neurobiology of anxiety. The effect seems to depend on both the GAL administration site as involved receptor subtype. The dorsal raphe nucleus (DRN) is distinguished by the presence of serotonergic neurons, important to mediate the antidepressant effect of several drugs. About 40% of the neurons of the DRN co-expressing serotonin and GAL. The activation of GALR1 in this structure decreases the firing rate of serotonergic neurons in the DRN. Previous results from our laboratory showed anxiolytic effect of GAL intra-DRN in rats exposed to the elevated T maze (ETM), but no effect on the escape, related to panic. One of the limitations of this model is that the escape (latency to leave the open arm) usually occurs within a few seconds, so that detect panicogenic effect (low latency escape) can be difficult. Thus, one aim of this study was to investigate the effect of intra-DRN rat GAL in another experimental model of panic, electrical stimulation of the dorsal periaqueductal gray matter (DPAG), more sensitive to detect panicogenic effect. Furthermore, given the existence of different subtypes of galaninergic receptors (GALR1 and GALR2) in the DRN with opposite transduction mechanisms, inhibitory and excitatory, respectively, it is possible that activation of GALR1 receptors is responsible for mediating the anxiolytic/panicogenic effect while activation of GALR2 receptors induces anxiogenic/panicolytic effect. Accordingly, we tested this hypothesis using a selective agonist for GALR1 (M617) and a selective agonist for GALR2 (AR-M1896) in the DRN in rats exposed to ETM. The administration of M617 1.0 and 3.0 nmol in the DRN facilitated inhibitory avoidance, suggesting an anxiogenic-like effect., while administration of AR-M1896 3,0nmoles in the DRN impaired the inhibitory avoidance, suggesting an anxiolytic-like effect, both without changing locomotor activity of animals tested in the open field. Also there was no effect of these drugs on the ETM escape behavior. Later, the pre-treatment with WAY100635 was tested in order to verify that administration of a 5-HT1A antagonist would be able to block the effects seen with GALR2 agonist in animals exposed to ETM. The anxiolytic effect of AR-M1896 was attenuated by the prior administration of WAY100635 at a dose of 0,18nmol. Therefore these results suggest a relationship between the observed effect with the AR-M1896, the release of 5-HT and activation of 5-HT1A receptors. And finally, the GAL 0,3nmol intra-DRN increased significantly the jumpping and trotting thresholds of animals submitted to electrical stimulation of the DPAG, suggesting a panicolytic effect. Together, the results show that the GAL in the DRN participates in the mediation of behavioral responses related to anxiety and, less clearly, to Panic Disorder. The results also shows that effect of GAL on anxiety depends galaninergic subtype receptor activated.
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    Enriquecimento ambiental como estratégia não farmacológica para prevenção dos efeitos de longo prazo da separação maternal
    (Universidade Federal do Espírito Santo, 2015-08-21) Ribeiro, Laisa Barroso; Bittencourt, Athelson Stefanon; Bittencourt, Ana Paula Santana de Vasconcellos; Rodrigues, Lívia Carla de Melo; Pires, Rita Gomes Wanderley
    The perinatal maternal relationship has a fundamental importance in the development of healthy neural circuits that remain as mental bequest throughout life. In this sense, adverse events in this period have the potential to induce psychopathology in adulthood, increasing vulnerability to psychiatric disorders and substance abuse. In this study, the Maternal Separation (MS) was performed in male Wistar rats, with the intention to mimic a sustained stress in human childhood. After that, the animals were submitted to the Environmental Enrichment protocol, a nonpharmacological strategy employed during a strong brain plasticity period, in order to prevent the harmful effects of MS. In adulthood, we proceeded to the behavioral tests for evaluate depression, anxiety and alcohol abuse, as well as biochemical tests as the analysis of plasmatic corticosterone, indicative of the reactivity of the hypothalamus-pituitary-adrenal (HPA) axis to acute stress, and analysis dopamine and metabolites in structures involved in brain reward process – the mesocorticolimbic way (nucleus accumbens and prefrontal cortex). Statistical analysis was performed using the Student t test and one-way, two-way, three-way or repeated measures analysis of variance (ANOVA)
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    INVESTIGAÇÃO DE MATERIAL E MÉTODO PARA APLICAÇÃO DE POLIÉSTER ALTERNATIVO NO PROCESSO DE PLASTINAÇÃO DE TECIDO NERVOSO
    (Universidade Federal do Espírito Santo, 2022-03-25) Juvenato, Laissa da Silva; Bittencourt, Athelson Stefanon; https://orcid.org/; http://lattes.cnpq.br/3498043196182770; https://orcid.org/; http://lattes.cnpq.br/; Soares, Kinglston; https://orcid.org/; http://lattes.cnpq.br/; Silva, Andre Romero da; https://orcid.org/0000000214976093; http://lattes.cnpq.br/3079774974302460
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    Plastinação com silicone de baixa viscosidade : estratégia para uma menor retração tecidual
    (Universidade Federal do Espírito Santo, 2020-12-15) Monteiro, Yuri Favalessa; Bittencourt, Athelson Stefanon; https://orcid.org/0000-0003-1378-2577; http://lattes.cnpq.br/3498043196182770; https://orcid.org/0000-0001-8521-5593; http://lattes.cnpq.br/7269203136333787; Soares, Kinglston; https://orcid.org/0000-0003-2669-391X; http://lattes.cnpq.br/7671657131724834; Rezende, Lucas Cunha Dias de; https://orcid.org/0000-0002-4095-3135; http://lattes.cnpq.br/6353284950167322; Baptista, Carlos Augusto de Camargo Souza; https://orcid.org/; http://lattes.cnpq.br/3554852890141199
    Plastination is an anatomical technique for preserving biological tissues, whose principle is the replacement of body fluids with a curable polymer. The main polymers used in the technique are epoxy, polyester and silicone, with silicone being the most used worldwide due to its versatility and greater range of use. The inputs are usually acquired via import, so the acquisition of alternative polymers of national acquisition would facilitate the diffusion of plastination. In addition, there are no studies in the literature that evaluate the use of low viscosity silicones in plastination, using tissue retraction as a parameter. With this, the idea of evaluating the nationally acquired silicone Polisil® Poliplast 1 (P1) and the imported silicone (reference) Biodur S10 emerges, investigating its chemical and rheological properties and how much to use in plastination. For chemical and rheological characterization, mass spectrometry, infrared spectroscopy and rheometry were used, in order to characterize the functional groups, molecular mass, study of flow and deformation of polymeric materials and viscosity. And to evaluate the use of these silicones in the technique, the tissue retraction of different tissues caused in the forced impregnation stage was investigated. The human tissues used were cardiac, pulmonary, splenic, renal, hepatic, muscular and bone. For this, a male human corpse sliced in 13-15 mm thick cuts was used, having as parameter the before and after plastination with the different silicones. It followed the standard slicing plastination protocol: dehydration, forced impregnation and curing. Half of the cuts obtained were plastinated with silicone P1 (group P1) and the other half with S10 (group S10). The results found in the infrared, mass spectrometry and rheometry tests showed that the structural formula of the silicone molecules is identical, compatible with the polydimethylsiloxane (PDMS) and presented a strong indication that the P1 silicone has less molar mass compared to S10, due to its lower viscosity, greater presence of silanol groups and distribution of m/z of the fragments obtained in EM. All tissues and anatomical segments analyzed in this study showed less or equal retraction when compared to the control group (S10) plastination with silicone P1. From this, it is concluded that the lower viscosity silicone promotes less tissue retraction, making it a viable alternative to the reference