Efeito da exposição subcrônica a ondas de radiofreqüência geradas por um aparelho de telefone celular convencional na função testicular de ratos Wistar adultos

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Efeitos do agente antiproliferativo de origem marinha ET-743 sobre o ciclo celular, apoptose e conteúdo de proteína Hsp70 em culturas de glioma humano

Ecteinascidina 743 (ET-743) é uma nova droga isolada de um tunicado marinho, a Ecteinascidia turbinata, que está na fase III dos estudos clínicos por sua marcada atividade anticâncer. Apesar de seu mecanismo de ação não estar completamente elucidado, tem sido demonstrado que a ET-743 se liga ao DNA formando adutos covalentes com o N2 da guanina. Além disso, a ET-743 tem sido relatada como potente inibidora da transcrição. No presente estudo, utilizou-se como modelo para a investigação dos efeitos antiproliferativos deste composto a linhagem celular derivada de glioblastoma humano, U-251 MG. Uma vez que o foco principal de atenção nos estudos sobre o mecanismo de ação da ET-743 esteja concentrado em suas interações com o DNA, a autora buscou avaliar outros aspectos de sua atividade antiproliferativa, quais sejam, o seu efeito sobre a distribuição das células no ciclo celular, sobre a atividade de enzimas associadas ao processo de apoptose, bem como sobre o conteúdo celular da proteína Hsp70. Em incubações de 0,5 nM por 48 h, a ET-743 causou um significante acúmulo das células na fase G2M do ciclo celular, o mesmo ocorrendo com doses mais elevadas (1,0 e 1,5) e incubações mais prolongadas (72 h). A ET-743 induziu morte celular dose-dependente e este efeito foi significativamente prevenido pelo inibidor de caspases z-VAD-fmk. Contudo, não foi observado aumento significativo nos níveis de Hsp70 após tratamento com ET-743. Considerando que alta expressão de Hsp70 é um dos principais mecanismos de proteção das células em condições de estresse, incluindo-se o tratamento com drogas citotóxicas, a não elevação de seus níveis na presença da ET-374 pode estar, ao menos em parte, relacionada à citotoxicidade produzida por este agente na linhagem estudada.

Estudo da fidelização dos clientes de telefonia celular na grande São Paulo em função do atendimento recebido por esses na área de call center das operadoras

O objetivo desse trabalho é fazer um estudo exploratório acerca da fidelização de usuários de serviços de telefonia celular, na Grande São Paulo, em função do atendimento percebido por ele, quando em contato com o Call Center da empresa. Buscou-se verificar quais os elementos importantes e impactantes do atendimento, assim como de que modo o atendimento prestado pelo Call Center impacta na fidelização do cliente à sua operadora. Para tanto, foi empreendida uma pesquisa de campo junto a clientes das diversas operadoras atuantes na região.

Análise de grandes eventos na cidade do Rio de Janeiro usando dados de telefonia celular

Os dados de telefonia celular são um instrumento valioso para analisar o comportamento da população urbana, uma vez que informação sobre a mobilidade das pessoas é difícil de obter. Estes podem oferecer estimativas em relação ao deslocamento e à ocupação da população nos espaços públicos, ajudando a elaborar medidas de planejamento urbano mais especificas e eficientes. A fim de examinar a movimentação ao redor da cidade do Rio de Janeiro em dias de grandes eventos, propomos uma metodologia com o objetivo de identificar aspectos desses eventos que permitem conhecer o público e oferecer soluções para os planejadores desenharem estratégias para a organização e segurança desses participantes. Palavras-chaves: mobilidade urbana. dados CDR. eventos públicos. Rio de Janeiro

Morfologia, estrutura celular, metabolismo, nutrição e multiplicação de bactérias e leveduras

Unidade 2

Celular

Dimensão: 434x850px

Caracterização físico-química e efeitos de frações polissacarídicas da alga amansia multifida na coagulação, inflamação, radicais livres e viabilidade celular

Galactans are polysaccharides sulfated present in the cell wall of red algae. Carrageenans are galactans well known in the food industry as gelling polysaccharides and for induce inflammatory process in rodents as animal model. The extraction of polysaccharides from A. multifida has been carried out by proteolysis and precipitation in different volumes of acetone, which produced three fractions (F1, F2, and FT). Chemical and physical analyses revealed that these fractions are sulfated galactan predominantly. Results of the antioxidant activity assays showed that all of these fractions have antioxidant activity and that was associated with sulfate content of the analysis of reducing power and total antioxidant capacity. However, these fractions were not effective against lipid peroxidation. The fraction FT presented higher activity on the APTT test at 200 μg (> 240 s). The assessment of the hemolytic activity showed that the FT fraction has the best activity, increasing lyses by the complement system to 42.3% (50 μg) (p< 0,001). The fraction FT showed the best yield, anticoagulant and hemolytic activity between the three fractions and therefore it was choose for the in vivo studies. The Inflammation assessment using the FT fraction (50 mg / kg MB) showed that the cellular migration and the IL-6 production increased 670.1% (p< 0,001) and 531.8% (p< 0,001), respectively. These results confirmed its use as an inflammation inducer in animal model. Cytotoxicity assay results showed that all fractions have toxic effects on 3T3 and HeLa cells after exposition of 48 hours, except when 100 μg for both F1 and FT were used. These results arise the discussion whether these polysaccharides it should be used as additive in foods, cosmetics and medicines.

Indução de morte celular em células de adenocarcinoma cervical humano (HeLa) pela lectina da esponja Cinachyrella apion (CaL)

Cancer is a term used to represent a set of more than 100 diseases, including malignant tumors from different locations. The malignancies are the second leading cause of death in the population, representing approximately 17% of deaths of known cause. Strategies that induce differentiation have had limited success in the treatment of established cancers. In this work, a lectin purified from the marine sponge Cinachyrella apion (CaL) was evaluated due to its hemolytic, cytotoxic and antiproliferative properties, besides the ability to induce cell death via apoptosis in tumor cells. The antiproliferative activity of CaL was tested against cell lines, with the highest inhibition of tumor growth for HeLa, reducing cell growth at a dose dependent manner, with a concentration of 10 μg/mL. The hemolytic activity and toxicity against peripheral blood cells were tested using the concentration of IC50 for both trials and twice the IC50 for analysis in flow cytometry, indicating that CaL is not toxic to these cells. To assess the mechanism of cell death caused by CaL in HeLa cells, we performed flow cytometry and western blotting. The results showed the lectin probably induces cell death by apoptosis activation by pro-apoptotic protein Bax, promoting mitochondrial membrane permeabilization, cell cycle arrest in S phase, with accumulation of cells of approximately 57% in this phase, and acting as both dependent and/or independent of caspases pathway. These results suggest that CaL has the potential to be used as drug treatment against cancer.

Avaliação do efeito do composto tipo heparina isolado do caranguejo Chaceon fenneri na hemostasia e na morte celular

Heparin is a pharmaceutical animal widely used in medicine due to its potent anticoagulant effect. Furthermore, it has the ability to inhibit the proliferation, invasion and adhesion of cancer cells to vascular endothelium. However, its clinical applicability can be compromised by side effects such as bleeding. Thus, the search for natural compounds with low bleeding risk and possible therapeutic applicability has been targeted by several research groups. From this perspective, this study aims to evaluate the hemorrhagic and anticoagulant activities and citotoxic effect for different tumor cell lines (HeLa, B16-F10, HepG2, HS-5,) and fibroblast cells (3T3) of the Heparin-like from the crab Chaceon fenneri (HEP-like). The HEP-like was purified after proteolysis, ion-exchange chromatography, fractionation with acetone and characterized by electrophoresis (agarose gel) and enzymatic degradation. Hep-like showed eletroforetic behavior similar to mammalian heparin, and high trisulfated /Nacetylated disaccharides ratio. In addition, HEP-like presented low in vitro anticoagulant activity using aPTT and a minor hemorrhagic effect when compared to mammalian heparin. Furthermore, the HEP-like showed significant cytotoxic effect (p<0.001) on HeLa, HepG2 and B16-F10 tumor cells with IC50 values of 1000 ug/mL, after incubation for 72 hours. To assess the influence of heparin-like on the cell cycle in HeLa cells, analysis was performed by flow cytometry. The results of this analysis showed that HEP-like influence on the cell cycle increasing S phase and decreasing phase G2. Thus, these properties of HEP-like make these compounds potential therapeutic agents

Concreto celular polimérico: influência na adição de resíduo de poliéster insaturado termofixo

This work addresses the production of lightweight concrete building elements, such as plates, prefabricated slabs for pre-molded and panels of fencing, presenting a singular concrete: the Lightweight Concrete, with special properties such low density and good strength, by means of the joint use of industrial waste of thermosetting unsaturated polyesters and biodegradable foaming agent, named Polymeric Lightweight Concrete. This study covered various features of the materials used in the composition of the Polymeric Lightweight Concrete, using a planning of factorial design 23, aiming at studying of the strength, production, dosage processes, characterization of mechanical properties and microstructural analysis of the transition zone between the light artificial aggregate and the matrix of cement. The results of the mechanical strength tests were analyzed using a computational statistics tool (Statistica software) to understand the behavior and obtain the ideal quantity of each material used in the formula of the Polymeric Lightweight Concrete. The definition of the ideal formula has the purpose of obtaining a material with the lowest possible dry density and resistance to compression in accordance with NBR 12.646/92 (≥ 2.5 MPa after 28 days). In the microstructural characterization by scanning electron microscopy it was observed an influence of the materials in the process of cement hydration, showing good interaction between the wrinkled face of the residue of unsaturated polyesters thermosetting and putty and, consequently, the final strength. The attaining of an ideal formula, given the Brazilian standards, the experimental results obtained in the characterization and comparison of these results with conventional materials, confirmed that the developed Polymeric Lightweight Concrete is suitable for the production of building elements that are advantageous for construction

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