Navegando por Autor "Rocha, Noeme Sousa"
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Item Cell cycle kinetics, apoptosis rates and gene expressions of MDR - 1, TP53, BCL - 2 and BAX in transmissible venereal tumour cells and their association with therapy response.(2016) Flórez, Luis Mauricio Montoya; Fêo, Haline Ballestero; Silva, Glenda Nicioli da; Yamatogi, Ricardo Seiti; Aguiar, Antonio José de Araujo; Araújo Junior, João Pessoa; Rocha, Noeme SousaTransmissible venereal tumour (TVT) generally presents different degrees of aggressiveness, which makes them unresponsive to conventional treatment protocols. This implies a progressive alteration of their biological profile. This study aimed to evaluate the cytotoxicity, cell survival, apoptosis and cell cycle alterations in TVT cell cultures subjected to treatment with vincristine. Similarly, it assessed possible implications of MDR-1, TP53, BCL-2, and BAX gene expressions in eight TVT primary cultures for both resistance to chemotherapy and biological behaviour.When comparing TVT cells receiving vincristine to those untreated, a statistical difference related to increased cytotoxicity and decreased survival rates, and alterations in G1 and S cell cycle phases were found but without detectable differences in apoptosis. Increased MDR-1 gene expression was observed after treatment. The groups did not differ statistically in relation to the TP53, BAX and BCL-2 genes. Although preliminary, the findings suggest that such augmented expression is related to tumour malignancy and chemotherapy resistance.Item Role of selective cyclo-oxygenase-2 inhibitor celecoxib in canine osteosarcoma cell culture.(2013) Bersano, Paulo Ricardo de Oliveira; Alves, Maria T. S.; Gartner, Maria F. M. R.; Ferrasi, Adriana Camargo; Lima Neto, João Ferreira de; Alvarenga, Fernanda da Cruz Landim e; Vexenat, Stephane Cássia; Alves, Carlos Eduardo Fonseca; Silva, Glenda Nicioli da; Rocha, Noeme SousaExperimental studies have shown that cyclo-oxygenase-2 (Cox2) is related to the development and pro-gression of tumors, since this enzyme is induced and expressed by cells such as macrophages, osteoblasts, “activated” endothelial cells, and tumor cells. The activity in tumors includes proliferation, cell transformation, tumor growth, inva- sion and metastasis and may play an important role in carcinogenesis of the canine osteosarcoma, since it has high ex- pression in tissue fragments. The combination of selective Cox2 inhibitors and other treatment modalities is the basis for a new anti-cancer therapy strategy. This in vitro study exposed primary cells of five different canine osteosarcoma cultures to selective Cox2 inhibitor at increasing concentrations and times. Results: For Cox2 negative cultures, despite the absence of differences, greater sensitivity of cells to treatment was observed. For Cox2 positive cultures, a higher number of necrotic cells were observed (P ≤ 0.05), when compared with negative cultures. For exposure times with Celecoxib doses, no difference (P > 0.05) was found between the three times analyzed for living, apoptotic and apop- totic/necrotic cells. There are similarities in the values of 24 h and 48 h, with slight reduction of living cells, increasing those undergoing apoptosis and apoptosis/necrosis. There was significance for necrosis (P ≤ 0.05). In 72 hours, a sig-nificant difference was observed between the other two previous values (P ≤ 0.05). It was found for the group of 100 μM•L−1, that there was a numerically greater signaling for apoptosis and lower (P = 0.08) for necrosis, and this point was the onset of the pharmacodynamic phenomenon, with drop in the values for living cells and increased number of necrotic cells, with a tendency (P = 0.08) for reducing the percentage of necrotic cells for the group of 100 μM•L−1 when compared to that of 10 μM•L−1. Conclusions: For Cox2 positive and negative cultures, there was difference for necrotic cells and there was no difference between Cox2 positive and Cox2 negative groups in relation to the percentage of living cells and apoptotic and apoptotic/necrotic cells. At time of 72 hours, higher percentage of living cells, lower percentage of apoptotic cells and increased percentage of necrotic cells in relation to groups of 24 and 48 hours were observed. A tendency for reducing the percentage of necrotic cells for the group of 100 μM•L−1 when compared to that of the group of 10 μM•L−1 was observed.Item Spontaneous mammary carcinomas in female dogs : association between the immunohistochemical degree of aggressiveness of tumors, intensity of DNA damage and residues of pyrethroids.(2013) Brandão, Yara de Oliveira; Colodel, Marcia Moleta; Silva, Glenda Nicioli da; Vexenat, Stephane Cássia; Ferreira, Isabelle; Silva, Yamê Fabres Robaina Sancler da; Bulla, Camilo; Rocha, Noeme SousaDiagnosis and biological behavior of breast cancer of female dog represent one of the biggest challenges facing the Veterinarian in recent years. Due to its exponential growth and the degree of aggressiveness, the exact cause of this tu- mor is probably multifactorial and it is believed that may suffer influence from environmental factors. Among the sus- pected environmental contaminants are the pyrethroids. Aiming to investigate the participation of pyrethroids in tu- morigenesis in female dogs, a study was conducted using 50 female dogs, 22 were positive for simple breast carcinoma (Group I), 18 with a diagnosis of complex breast carcinoma (Group II) and 10 negative (Group III) for breast cancer. In order to detect DNA damage, the Comet assay was performed on mammary samples of these animals, which also had samples submitted to the technique of High Performance Liquid Chromatography (HPLC), which aimed to quantify the concentration of pyrethroids. The results of HPLC of each animal were compared with those obtained by the Comet assay analysis of variance and the means were compared by the test groups “Student T” at the significance level of p 0.05. Despite presenting correlation between the amount of DNA damage and tumor aggressiveness, no statistical dif- ferences were found in the DNA damage of different histologic types of breast carcinoma. As for pyrethroids, even these were detected in 22% of tumor tissues and peritumoral fat, there was no difference in DNA damage between cells exposed and not exposed to environmental contaminant.