Estudo das características físico-químicas e biológicas pela adesão de osteoblastos em superfícies de titânio modificadas pela nitretação em plasma

SILVA, J. S. P. Estudo das características físico-químicas e biológicas pela adesão de osteoblastos em superfícies de titânio modificadas pela nitretação em plasma. 2008. 119 f. Tese (Doutorado) - Faculdade de Medicina, Universidade de São Paulo. São Paulo, 2008.

Bibliotecas digitais de teses e dissertações brasileiras: paradigma do acesso livre à informação científica

A evolução da comunicação científica ao longo do tempo e o impacto causado pela A evolução da comunicação científica ao longo do tempo e o impacto causado pela A evolução da comunicação científica ao longo do tempo e o impacto causado pela se analisar as contribuições da Biblioteca Digital de Teses e Dissertações (BDTD)para a comunicação científica atual, destacando possibilidades emergentes e desafios a serem superados. Apresenta uma breve evolução da comunicação científica ao longo do tempo; discute os impactos causados pela Internet na comunicação, disponibilização e acessibilidade de informações técnico-científicas; e caracteriza BDTD destacando os desafios a serem superados. Dentre eles estão, a questão dos direitos autorais que ocasionam a baixa adesão dos autores ao projeto piloto do IBICT para disponibilizar teses e dissertações no meio eletrônico. Para este desafio, são apontadas sugestões.

Efeito de glucanas do fungo Caripia montagnei em modelo de inflamação intestinal induzida por tnbs em ratos Wistar e em células de carcinoma de cólon humano HT-29

Compounds derived from fungi has been the subject of many studies in order to broaden the knowledge of their bioactive potential. Polysaccharides from Caripia montagnei have been described to possess anti-inflammatory and antioxidant properties. In this study, glucans extracted from Caripia montagnei mushroom were chemically characterized and their effects evaluated at different doses and intervals of treatment. It was also described their action on colonic injury in the model of colitis induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS), and its action on cells of the human colon carcinoma (HT-29). Compounds extracted of C. montagnei contain high level of carbohydrates (96%), low content of phenolic compounds (1.5%) and low contamination with proteins (2.5%). The (FT-IR) and (NMR) analysis showed that polysaccharides from this species of mushroom are composed of &#945;- and &#946;-glucans. The colonic damage was evaluated by macroscopic, histological, biochemical and immunologic analyses. The results showed a reduction of colonic lesions in all groups treated with the glucans of Caripia montagnei (GCM). GCM significantly reduced the levels of IL-6 (50 and 75 mg/kg, p < 0.05), a major inflammatory cytokine. Biochemical analyses showed that such glucans acted on reducing levels of alkaline phosphatase (75 mg/kg, p < 0.01), nitric oxide (p < 0.001), and myeloperoxidase (p < 0.001). These results were confirmed microscopically by the reduction of cellular infiltration. The increase of catalase activity suggest a protective effect of GCM on colonic tissue, confirming their anti-inflammatory potential. GCM displayed cytostatic activity against HT-29 cells, causing accumulation of cells in G1 phase, blocking the cycle cell progression. Those glucans also showed ability to modulate the adhesion of HT-29 cells to Matrigel® and reduced the oxidative stress. The antiproliferative activity against HT-29 cells displayed by GCM (p <0.001) can be attributed to its cytostatic activity and induction of apoptosis by GCM

Processamento e análise de imagens na caracterização da superfície do titânio submetido a um ensaio de cultura de células

This work aims to develop a methodology for analysis of images using overlapping, which assists in identification of microstructural features in areas of titanium, which may be associated with its biological response. That way, surfaces of titanium heat treated for 08 (eight) different ways have been subjected to a test culture of cells. It was a relationship between the grain, texture and shape of grains of surface of titanium (attacked) trying to relate to the process of proliferation and adhesion. We used an open source software for cell counting adhered to the surface of titanium. The juxtaposition of images before and after cell culture was obtained with the aid of micro-hardness of impressions made on the surface of samples. From this image where there is overlap, it is possible to study a possible relationship between cell growth with microstructural characteristics of the surface of titanium. This methodology was efficient to describe a set of procedures that are useful in the analysis of surfaces of titanium subjected to a culture of cells

Adesão, proliferação e genotoxicidade celular de celulose bacteriana modificada por plasma

Bacterial cellulose (BC) has a wide range of potential applications, namely as temporary substitute skin in the treatment of skin wounds, such as burns, ulcers and grafts. Surface properties determine the functional response of cells, an important factor for the successful development of biomaterials. This work evaluates the influence of bacterial cellulose surface treatment by plasma (BCP) on the cellular behavior and its genotoxicity potential. The modified surface was produced by plasma discharge in N2 and O2 atmosphere, and the roughness produced by ion bombardment characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Cell adhesion, viability and proliferation on BCP were analysed using crystal violet staining and the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium (MTT) method. Genotoxicity was evaluated using the comet and cytokinesis block micronucleus assay. The results show that the plasma treatment changed surface roughness, producing an ideal cell attachment, evidenced by more elongated cell morphology and improved proliferation. The excellent biocompatibility of BCP was confirmed by genotoxicity tests, which showed no significant DNA damage. The BCP has therefore great potential as a new artificial implant

Expressão da E-caderina em carcinoma de células escamosas e no tumor de células basais de cães

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A influência da criopreservação nas células mesenquimais indiferenciadas do ligamento periodontal de humanos análise comparativa in vitro

Cryopreservation is a process where cells or biological tissues are preserved by freezing at very low temperatures and aims to cease reversibly, in a controlled manner, all the biological functions of living tissues, i.e., maintain cell preservation so that it can recover with high degree of viability and functional integrity. This study aimed to evaluate the influence of cryopreservation on the mesenchymal stem cells originating from the periodontal ligament of human third molars by in vitro experiments. Six healthy teeth were removed and the periodontal cells grown in culture medium containing &#945;-MEM supplemented with antibiotics and 15% FBS in a humidified atmosphere with 5% CO2 at 37° C. Cells isolated from each sample were divided into two groups: Group I - immediate cell culture (not fresh cryopreserved cells) and Group II - cell cryopreservation, during a period of 30 days. Analyses of rates of cell adhesion and proliferation in different groups were performed by counting the cells adhered to the wells, in intervals of 24, 48 and 72 hours after the start of cultivation. The number of cells in each well was obtained by counting viable cells with the use of hemocytometer and the method of exclusion of cells stained by trypan blue. The difference between groups for each of the times was analyzed by Wilcoxon test. Regarding the temporal evolution for each group, analysis was done by Friedman's test to verify the existence of differences between times and, when it existed, the Wilcoxon penalty was applied. The results showed no statistically significant difference between the two groups analyzed in this study. Therefore, we conclude that the cryopreservation process, after a period of 30 days, did not influence the cell type studied, and there was no difference in growth capacity in vitro between the groups

Isolamento, caracterização e diferenciação de células-tronco mesenquimais do líquido amniótico equino obtido em diferentes idades gestacionais

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Interação de Paracoccidioides brasiliensis com células endoteliais

Paracoccidioidomycosis has a variety of clinical manifestations and Paracoccidioides brasiliensis, the causative agent, may infect many tissues, most importantly the lungs. Migration of pathogenic yeasts to the endothelial cell layer is considered a prerequisite for multiple organ invasion and dissemination of the fungus. In this study of the adhesion of P. brasiliensis to endothelial cells in vitro, we investigated whether this adhesion could represent a mechanism of dissemination. To this end, as well as using conventional optical microscopy, an alternative in vivo technique was developed, to detect the presence of fungal cells in umbilical cords embedded in paraffin wax. An experiment on the migration of P. brasiliensis through an endothelial cell monolayer was carried out, and the migration of yeast cells was greater, and took less time, in control wells with no cells. The fungus crossed the monolayer, but, compared to control wells, the migration-rate was about 30% lower. This shows that the monolayer only partially blocked migration of the fungus. In these experiments, we had great difficulty finding P. brasiliensis adhered to the cell monolayer, when it was examined at different times, suggesting that migration of the fungus across the endothelial layer is very fast, and cannot normally be observed in cell culture in vitro. Thus, P. brasiliensis can cross the endothelium rapidly and probably invades deeper tissue.

Expressão gênica das adesinas e fatores de virulência da fase miceliar e leveduriforme do complexo paracoccidioides e de sua interação com células epiteliais e fagócitos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Estruturação ex-vivo de vasos sanguíneos a partir da diferenciação de células tronco de coelhos

Pós-graduação em Pesquisa e Desenvolvimento (Biotecnologia Médica) - FMB

Expressão da e-caderina e do fator de crescimento do endotélio vascular no carcinoma de células escamosas e no tumor de células basais de cães

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeito da quercetina sobre alguns fatores relacionados com a virulência de Staphylococcus aureus

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeito do condicionamento radicular com ácido cítrico, citrato de sódio, EDTA e tetraciclina na adesão de elementos sanguíneos. Estudo por meio de microscopia eletrônica de varredura. -

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Obtenção, manutenção e caracterização de células-tronco embrionárias equinas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)