Teses em Neurociências e Biologia Celular (Doutorado) - PPGNBC/ICB
URI Permanente para esta coleçãohttps://repositorio.ufpa.br/handle/2011/2390
O Doutorado 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) Análise de patógenos orais entre indivíduos portadores de câncer gástrico e indivíduos sem câncer(Universidade Federal do Pará, 2021-06) OLIVEIRA, Gyselle Ribeiro de Carvalho; BURBANO, Rommel Mario Rodriguéz; http://lattes.cnpq.br/4362051219348099; https://orcid.org/0000-0002-4872-234XThe loss of teeth and lack of oral hygiene have been associated with the risk of developing gastric cancer in several populations evidenced in epidemiological studies. In this study, we quantitatively compared the proportion of oral pathogens in individuals with gastric cancer and individuals without cancer in a referral hospital in the city of Belém, Brazil. This study evaluated 192 patients with gastric cancer and 192 patients without cancer. Periodontal clinical examination was performed, and all individuals were submitted to the collection of salivary and dental biofilms. When comparing the median periodontal indexesin the gastric and cancer-free groups, it was statistically significant in the gastric cancer group compared to the probing depth of the periodontal pocket. Levels of bacterial DNA were observed in saliva and dental plaque, with a statistically significant difference between individuals with cancer and without neoplasia in all the bacteria surveyed. Significant relationships between biological agents and gastric cancer have been found in bacterial species that cause high rates of periodontal pathology and caries. The results suggest a different quantitative association in the presence of oral pathogens between individuals without cancer and patients with gastric cancer. As noted, it cannot be said that the bacteria present in the oral cavity increase the risk of gastric cancer or are aggravating factors of the disease. However, it is worth mentioning that, as it is part of the digestive system, the lack of care for the oral cavity can negatively affect the treatment of patients with gastric cancer.Item Acesso aberto (Open Access) Atividade antineoplásica da 1-desoxinojimiricina em modelos de câncer in vitro(Universidade Federal do Pará, 2021-12) FONSECA, Suzanne Suely Santos da; PEREIRA JÚNIOR, Antônio; http://lattes.cnpq.br/1402289786010170; https://orcid.org/0000-0002-0808-1058Cancer is one of the diseases that kill the most in Brazil, with alarming projections until 2030. In view of the problems related to cancer treatment, such as the compromise of healthy cells and, consequently, the presence of adverse effects, it is imperative to seek of alternative substances that may have antineoplastic effects and that are effective in the treatment of patients with this disease. In this way, the use of bioactive compounds has been widely used in the fight against neoplasms. Thus, the substance 1-deoxynojimyricin (1-DNJ) isolated from Bagassa guianensis may have great anticancer potential. In view of the problems related to cancer treatment, such as the impairment of healthy cells and, consequently adverse effects, it is necessary to search alternative substances that may have antineoplastic effects and they are effective in the treatment of patients with this disease. The objective of this study was to evaluate the effect of 1-deoxynojirimycin (1-DNJ) extracted from wood residue of the species Bagassa guianensis in different cancer cell lines to investigate possible antineoplastic actions in vitro using gastric adenocarcinoma and glioblastoma cancer cell lines. To do that, it was evaluated the effect of the substance 1-deoxynojirimycin on cell viability in vitro after 72h of treatment in cell lines ACP02 and A172. We also evaluated the effect of this bioactive compound on cell migration pattern, cell death by apoptosis and cell cycle changes using flow cytometry and reactive oxygen production. The results showed that 1-deoxynojirimycin makes a significant reduction in cell viability of cancer cell cultures in both glioblastoma (A172) and gastric cancer cell (ACP02) cell lines. The reduction in viability appears to be more effective in glioblastoma cell lines, with a common ic50 much lower when compared to other cell lines. We propose that the reduction in viability may be related to the decrease in reactive oxygen production in both lines after treatment with 1-DNJ. Besides that, 1-DNJ interrupts the cell cycle, prevents cell migration and induces necrosis-like cell death in the ACP02 lineage and apoptosis in the A172 lineage. Therefore, we suggest that 1-deoxynojirimycin may be an important and effective chemopreventive substance for the treatment of glioblastoma and gastric adenocarcinoma cancers.Item Acesso aberto (Open Access) Expressão gênica durante o desenvolvimento ocular e regulação de assimetria de opsinas na espécie Anableps anableps, peixe de quatro olhos(Universidade Federal do Pará, 2022-11) SOUSA, Daniele Salgado de; SCHNEIDER, Patrícia Neiva Coelho; http://lattes.cnpq.br/9584217233879031The ocular development is a complex process orchestrated by several events that include: cell specification, morphogenesis and differentiation. All these developmental and functional processes are extremely conserved among living vertebrate species, however, unique adaptations are sometimes observed, such as in fish of the genus Anableps. Unlike most fishes, which use their eyes to explore a submerged world, in Anableps anableps (Anablepidae: Cyprinodontiformes), the eye is adapted for the simultaneous perception of a world above and below the water line. These exceptional adaptations include: duplicated corneas and pupils, as well as a specialized retina region associated with simultaneous aerial and aquatic vision, and which have asymmetrical gene expression. Recently, by transcriptomic analysis of the developing eyes of A. anableps, 20 non-visual opsin genes were identified to be asymmetrically expressed between pre- and post-duplication stages of corneas and pupils. Thus, here, we analyzed by in situ hybridization the gene expression of a bistable opsin (parapinopsin) and a neuropsin (Opn5) in A. anableps larvae. Our data showed that the pattern of gene expression of these opsins is symmetrical between the dorsal and ventral retina, respectively, with expression in the ONL, INL and GCL layers. We also investigated the expression of three non-visual melanopsin genes (opn4x1, opn4x2, opn4m3), one eleost multiple tissue opsin (tmt1b), and two visual opsins (lws and rh2-1) in the dorsal and ventral retinas of juvenile A. anableps, after changing the photic conditions in which the juvenile fish were. Then, we showed that in the transition from an environment of high turbidity to one of clear water, opsins have their expression patterns changed. Additionally, by immunofluorescence, we revealed the expression of Lamin A/C, proteins expressed as part of eye development in A. anableps as well as in other developing organisms, as well as in adult individuals. Therefore, we believe that the information described here elucidates many aspects of the molecular mechanisms behind the development and adaptive plasticity of A. anableps’ eyes.