Papers by Edna Constanza Gomez Victoria
Microvascular Research, May 1, 2020
Ischemic stroke represents a major cause of adult death and severe neurological disability worldw... more Ischemic stroke represents a major cause of adult death and severe neurological disability worldwide. Reperfusion following brain ischemia produces an inflammatory cascade that increases brain damage. In this context, matrix metalloproteinases (MMPs) play an important role as pro-inflammatory mediators. The MMP 2 up-regulation seems to promote matrix degradation, blood-brain barrier (BBB) disruption and facilitates the influx of peripheral inflammatory cells to the brain after stroke. However, there are not studies about MMP-1 in this condition. The aim of this study is to evaluate the association of brain damage, inflammatory response and the immunostaining profile of matrix metalloproteinases 1 and 2 after transient global cerebral ischemia. Mice were submitted to bilateral common carotid arterial occlusion (BCCAo) during 25 min. After three days of reperfusion, the neurological deficit score was evaluated and the animals were euthanized. Brain samples were collected in order to analyze the histopathological damage, MMPs 1 and 2 immunostaining and cytokines and chemokines levels. Ischemic group showed neurological deficits associated with brain lesions, characterized by necrotic core and penumbra zone three days after reperfusion. Higher brain immunostaining of MMP-1 and MMP-2 was observed in BCCAo samples than in sham samples. Ischemic group also exhibited increased brain levels of the cytokines tumoral necrosis factor (TNF) and interleukin 1β (IL-1β), chemokine (C-X-C motif) ligand 1 (CXCL1), and chemokine (C-C motif) ligand 5 (CCL5) in comparison to sham group. Our results suggest that the MMP-1 and MMP-2 raise, associated with the up-regulation of inflammatory mediators, contributes to brain damage and neurological deficits after global brain ischemia followed by three days of reperfusion in mice.
Neurology Psychiatry and Brain Research, Dec 1, 2020
When the target of a saccadic eye movement is displaced while the eyes move this displacement is ... more When the target of a saccadic eye movement is displaced while the eyes move this displacement is often not noticed (saccadic suppression of displacement, SSD). We present a neurobiologically motivated, computational model of SSD and compare its simulation results to experimental data. The model offers a simple explanation of the effects of pre-and post-saccadic stimulus blanking on SSD in terms of peri-saccadic network dynamics. Under normal peri-saccadic conditions pre-and post-saccadic stimulus traces are recurrently integrated with reference to present and future eye position, whereas blanking diminishes the pre-saccadic stimulus trace and thus leads to an uninfluenced integration of the post-saccadic stimulus trace. We show that part of the intersubject variability in SSD can be explained by differences in decision thresholds of this integration process.
Current Neurovascular Research, Jun 15, 2017
Brain Research Bulletin, 2016
Stroke is one of the most frequent causes of death and disability worldwide leading to a signific... more Stroke is one of the most frequent causes of death and disability worldwide leading to a significant clinical and socioeconomic burden. Although different mechanisms are involved in the pathogenesis of stroke, inflammatory response occurs after ischemia and contributes to the expansion of brain injury. Platelet-activating factor receptor (PAF) plays crucial roles in both physiological and pathological conditions in the brain. PAF receptor (PAFR) may be expressed on cellular and nuclear membranes of various cell types, especially leukocytes, platelets, endothelial cells, neuronal cells and microglia. Herein, using mice lacking the PAFR receptor (PAFR(-/-)), we investigate a potential role for this receptor during experimental transient global cerebral ischemia and reperfusion (BCCAo). In PAFR deficiency, we observed a significant improvement in the neurological deficits, which were associated with a reduction of brain infarcted area as evaluated by triphenyltetrazolium chloride (TTC). Moreover, a decrease in the percentage of necrotic cavities areas and in the frequency of ischemic neurons was also found by employing histometric analysis. In addition, in PAFR(-/-) mice there was prevention of caspase-3 activation and decreased vascular permeability and brain edema. Decreased brain levels of the cytokines tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta) and the chemokine (C-X-C motif) ligand 1 (CXCL1) by ELISA were also detected in PAFR(-/-) BCCAo animals. Taken together, our results suggest that PAFR activation might be crucial for the global brain ischemia and reperfusion injury.
Agradecimentos À Deus por todas as bênçãos e por ter me dado outra oportunidade de vida para conc... more Agradecimentos À Deus por todas as bênçãos e por ter me dado outra oportunidade de vida para concluir este trabalho e continuar com meu caminho para conseguir meus sonhos. À minha família, especialmente a meus pais Astrid e Jesus, por todo seu amor incondicional, incentivo, apoio e cuidado sempre, igualmente a meu amor e companheiro de vida Jaime Alejandro por ir juntos da mão em cada momento. À professora Milene Alvarenga Rachid, pela confiança em me receber como sua primeira aluna de doutorado, por toda sua ajuda nesse projeto. Por todo carinho, apoio, conselhos e aprendizado nestes quatro anos, sou imensamente grata. Ao professor Marcelo Vidigal, por ter me ajudado no seu laboratório, por todo apoio e dedicação. Ao professor Antônio Teixeira, pela disponibilidade e importante contribuição no desenvolvimento do projeto. À todas as companheiras de laboratório de Patologia Celular e Molecular que me ajudaram em cada processo, pela troca de conhecimentos e incentivo; especialmente agradeço Eliana, a menina amiga de alegrias e tristezas. À toda equipe da Pós-graduação em Patologia: Ao colegiado, à todos os professores por todo apoio e toda colaboração, as técnicas pela ajuda rápida no processamento das amostras, secretarias especialmente a Danielle e colegas alunos de mestrado e doutorado, por toda ajuda e dedicação. Todos todos contribuíram com um grão de areia para o desenvolvimento deste trabalho.
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Papers by Edna Constanza Gomez Victoria