249 resultados para Cell culture techniques


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Objectives: To evaluate the antimicrobial activity of Arctium lappa L. extract on Staphylococcus aureus, S. epidermidis, Streptococcus mutans, Candida albicans, C. tropicalis and C. glabrata. In addition, the cytotoxicity of this extract was analyzed on macrophages (RAW 264.7).Design: By broth microdilution method, different concentrations of the extract (250-0.4 mg/mL) were used in order to determine the minimum microbicidal concentration (MMC) in planktonic cultures and the most effective concentration was used on biofilms on discs made of acrylic resin. The cytotoxicity A. lappa L. extract MMC was evaluated on RAW 264.7 by MTT assay and the quantification of IL-1 beta and TNF-alpha by ELISA.Results: The most effective concentration was 250 mg/mL and also promoted significant reduction (log(10)) in the biofilms of S. aureus (0.438 +/- 0.269), S. epiderrnidis (0.377 +/- 0.298), S. mutans (0.244 +/- 0.161) and C. albicans (0.746 +/- 0.209). Cell viability was similar to 100%. The production of IL-beta was similar to the control group (p > 0.05) and there was inhibition of TNF-alpha (p < 0.01).Conclusions: A. lappa L. extract was microbicidal for all the evaluated strains in planktonic cultures, microbiostatic for biofilms and not cytotoxic to the macrophages. (C) 2014 Elsevier Ltd. All rights reserved.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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

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OBJETIVO: Avaliar a taxa de proliferação de fibroblastos provenientes de pterígios recidivados e da cápsula de Tenon normal, quando expostos in vitro ao tacrolimus (FK 506). MÉTODOS: Foi realizado estudo prospectivo, controlado, avaliando-se 8 amostras de explantes de cápsula de Tenon de pterígios recidivados e 6 de cápsula de Tenon normal, obtidas na Faculdade de Medicina de Botucatu - UNESP. A cápsula de Tenon normal foi colhida da região temporal inferior, do mesmo portador de pterígio. As amostras foram cultivadas em meio específico e posteriormente expostas ao tacrolimus 1M (FK 506), em única exposição, com avaliação da taxa de proliferação celular 1, 5, 12 e 19 dias após a exposição. RESULTADOS: Avaliando-se a proliferação dos fibroblastos provenientes de cápsula de Tenon de pterígios recidivados e da cápsula de Tenon normal, os fibroblastos expostos ao tacrolimus tiveram taxa de proliferação significativamente menor (p<0,05) do que quando não houve exposição a droga, quando a avaliação foi feita 1 dia após a exposição. Quando a avaliação foi feita 19 dias após a exposição, a taxa de proliferação foi maior nos grupos expostos a droga. CONCLUSÃO: Os fibroblastos provenientes da cápsula de Tenon de pterígios recidivados apresentaram taxa de proliferação significativamente menor um dia após a exposição ao tacrolimus. Novos estudos devem ser realizados para definir dose e tempo de exposição dos fibroblastos a droga, com o intuito de definir se o tacrolimus pode ser útil como tratamento coadjuvante do pterígio.

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Purpose: To evaluate the proliferation rate of recurrent pterygium and normal Tenon's capsule fibroblasts after exposure to triamcinolone.Methods: Explants of recurrent pterygia and normal Tenon's capsule of the same carrier were cultured. The fibroblasts were cultured and subcultured until the third passage and subsequently exposed to triamcinolone. The cell proliferation rate was evaluated 3, 6, 12 and 18 days after the exposure.Results: Fibroblasts exposed to triamcinolone had significantly lower proliferation rate (P < 0.05) compared to those not exposed, when the evaluation was performed 3, 6 and 12 days later. In the 18th day after exposure, there was a return in the proliferation rate, with statistical significance, only in the pterigyum fibroblasts.Conclusion: Both the fibroblasts from normal Tenon's capsule as from recurrent pterygia showed significantly lower proliferation rate after exposure to triamcinolone. After 18 days from the exposition, pterygium fibroblasts recovered the proliferation. The results suggested the triamcinolone might be useful as adjuvant in pterygium treatment.

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OBJETIVO: Avaliar o comportamento dos fibroblastos da cápsula de Tenon de pterígios e normais em cultura, quando expostos a ciclosporina 0,05%. MÉTODOS: Estudo prospectivo, controlado, do qual participaram 20 portadores de pterígio primário. Foram colhidas amostras da cápsula de Tenon normal e proveniente do pterígio, ambas do mesmo indivíduo, colocadas para crescimento em cultura e expostas a ciclosporina 0,05%. As avaliações foram feitas aos 3, 6, 12 e 17 dias após a exposição. RESULTADOS: Das amostras colhidas, 7 foram utilizadas para exposição a ciclosporina - 6 provenientes de pterígios e 1 da Tenon normal. Houve redução significativa na proliferação celular das culturas de fibroblastos expostos a ciclosporina (p<0,05). CONCLUSÃO: A ciclosporina 0,05% é capaz de inibir a proliferação de fibroblastos provenientes da cápsula de Tenon de pterígio e também da Tenon normal. Novos estudos devem ser providenciados para definir o papel da ciclosporina no tratamento do pterígio.

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Statement of problem. Adverse reactions to the materials used for the fabrication and reline of removable denture bases have been observed.Purpose. The purpose of this study was to systematically review the published literature on the cytotoxicity of denture base and hard reline materials.Material and methods. MEDLINE via PubMed, Google Scholar, and Scopus databases for the period January 1979 to December 2009 were searched with the following key words: (biocompatibility OR cytotoxic* OR allergy OR burning mouth OR cell culture techniques) and (acrylic resins OR denture OR monomer OR relin* OR denture liners). The inclusion criteria included in vitro studies using either animal or human cells, in which the cytotoxicity of the denture base and hard chairside reline resins was tested. Studies of resilient lining materials and those that evaluated other parameters such as genotoxicity and mutagenicity were excluded. Articles published in the English language and in peer-reviewed journals focusing on the cytotoxicity of these materials were reviewed.Results. A total of 1443 articles were identified through the search. From these, 20 studies were judged to meet the selection criteria and were included in the review. In the majority of the studies, continuous cell lines were exposed to eluates of specimens made from the materials, and mitochondrial activity was used to estimate cell viability. The tested acrylic resins were grouped according to 5 major categories: (1) heat-polymerized; (2) microwave-polymerized; (3) autopolymerizing; (4) light-polymerized; and (5) hard chairside reliners.Conclusions. This review provided some evidence that the heat-polymerized resins showed lower cytotoxic effects than autopolymerizing denture base acrylic resins and light or dual polymerized reline resins. However, because of the large number of variables in the reviewed literature, a definitive conclusion could not be drawn. (J Prosthet Dent 2012;107:114-127)

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INTRODUÇÃO: O reparo tissular é o objetivo final da cirurgia. A cultura celular requer arcabouço mecânico que dê suporte ao crescimento celular e difusão dos nutrientes. O uso do plasma rico em plaquetas (PRP) como um arcabouço 3D possui diversas vantagens: é material biológico, de fácil absorção pós-transplante, rico em fatores de crescimento, em especial PDGF- ββ e TGF-β que estimula síntese de matriz extracelular na cartilagem. OBJETIVO: Desenvolver arcabouço 3D à base de PRP. MATERIAIS E MÉTODOS: Duas formas foram idealizadas: Sphere e Carpet. Condições estéreis foram utilizadas. O gel de plaquetas permaneceu em cultura celular, observado diariamente em microscópio invertido. RESULTADOS: Ambos arcabouços obtiveram sucesso, com aspectos positivos e negativos. DISCUSSÃO: A forma Sphere não aderiu ao plástico. Observou-se retração do gel e investigação ao microscópio dificultada devido às áreas opacas no campo visual. A forma Carpet não aderiu ao plástico e apresentou-se translúcida. O tempo de estudo foi de 20 dias. CONCLUSÕES: A produção de um arcabouço 3D PRP foi um sucesso, e trata-se de uma alternativa que necessita ser mais utilizado e investigado para que se consolide em uma rota eficiente e confiável na tecnologia de engenharia tissular, particularmente em cultura de tecido cartilaginoso.

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

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We studied the synergistic effect of glucose and prolactin (PRL) on insulin secretion and GLUT2 expression in cultured neonatal rat islets. After 7 days in culture, basal insulin secretion (2.8 mM glucose) was similar in control and PRL-treated islets (1.84 ± 0.06% and 2.08 ± 0.07% of the islet insulin content, respectively). At 5.6 and 22 mM glucose, insulin secretion was significantly higher in PRL-treated than in control islets, achieving 1.38 ± 0.15% and 3.09 ± 0.21 % of the islet insulin content in control and 2.43 ± 0.16% and 4.31 ± 0.24% of the islet insulin content in PRL-treated islets, respectively. The expression of the glucose transporter GLUT2 in B-cell membranes was dose-dependently increased by exposure of the islet to increasing glucose concentrations. This effect was potentiated in islets cultured for 7 days in the presence of 2 μg/ml PRL. At 5.6 and 10 mM glucose, the increase in GLUT2 expression in PRL-treated islets was 75% and 150% higher than that registered in the respective control. The data presented here indicate that insulin secretion, induced by different concentrations of glucose, correlates well with the expression of the B-cell-specific glucose transporter GLUT2 in pancreatic islets.

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Objective: The purpose of this study was to evaluate the effect of erbium:yttrium-aluminum-garnet laser instrumentation of root surfaces on the morphology of fibroblasts from continuous lineage. Method and materials: Dentinal slices with 4 mm2 of surface area were obtained from teeth extracted for severe periodontal involvement. Specimens were assigned to one of three treatment groups: group 1, application of the laser with an energy level of 250 mJ at 103 pulses per second; group 2, application of the laser with an energy level of 80 mJ at 166 pulses per second; and group 3, similar to group 2, but with concomitant water irrigation of the device. The specimens were incubated in multiwell plates containing cell culture media. After 24 hours, the specimens were submitted to routine preparation for scanning electron microscopy. Three independent and blind examiners used photomicrographs to evaluate the morphology of the fibroblasts: 0 = without cells; 1 = flat cells; 2 = round cells; and 3 = combination of round and flat cells. Results: Statistical analysis indicated that there were significant differences among treatment groups and that group 3 was significantly different from groups 1 and 2. Conclusion: There was no difference between groups 1 and 2 in the morphology of fibroblasts. Laser instrumentation with concomitant irrigation impaired the adhesion of fibroblasts to dentinal surfaces.

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PURPOSE: To evaluate the number and morphology of fibroblasts grown on machined titanium healing abutments treated with an airpowder system. MATERIALS AND METHODS: Twenty-six abutments were assigned to two experimental groups: control (no treatment) and treated (exposed to the Prophy-Jet for 30 seconds). The specimens were incubated for 24 hours with fibroblastic cells in multiwell plates, followed by routine laboratory processing for scanning electron microscope analysis. The specimens were photographed at x 350, and the cell number was counted on an area of approximately 200 um2. RESULTS: No significant differences were found on morphology between the groups (P > 0.05); however, the control group presented a significantly greater amount of cells (71.44 +/- 31.93, mean +/- SD) in comparison with treated group (35.31 +/- 28.14), as indicated by a nonpaired t test (P = 0.001). CONCLUSION: The use of an air-abrasive prophylaxis system on the surface of titanium healing abutments reduced the cells proliferation but did not influence cell morphology.

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This article investigates a strain of the yeast Aureobasidium pullulans for cellulase and hemicellulase production in solid state fermentation. Among the substrates analyzed, the wheat bran culture presented the highest enzymatic production (1.05 U/mL endoglucanase, 1.3 U/mL β-glucosidase, and 5.0 U/mL xylanase). Avicelase activity was not detected. The optimum pH and temperature for xylanase, endoglucanase and β-glucosidase were 5.0 and 50, 4.5 and 60, 4.0 and 75°C, respectively. These enzymes remained stable between a wide range of pH. The β-glucosidase was the most thermostable enzyme, remaining 100% active when incubated at 75°C for 1 h. © 2007 Humana Press Inc.

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Objectives: To examine the effects of triiodothyronine (T3), 17β-estradiol (E2), and tamoxifen (TAM) on transforming growth factor (TGF)-α gene expression in primary breast cancer cell cultures and interactions between the different treatments. Methods and results: Patients included in the study (no.=12) had been newly diagnosed with breast cancer. Fresh human breast carcinoma tissue was cut into 0.3-mm slices. These slices were placed in six 35-mm dishes on 2-ml organ culture medium. Dishes received the following treatments: dish 1: ethanol; dish 2: T3; dish 3: T3+TAM; dish 4: TAM; dish 5: E2; dish 6: E2+TAM. TGF-α mRNA content was normalized to glyceraldehyde-3-phosphate dehydrogenase mRNA levels. All tissues included in this study were positive for estrogen receptor (ER) and thyroid hormone receptor expression. Treatment with T3 for 48 h significantly increased TGF-α mRNA levels compared to controls (15-fold), and concomitant treatment with TAM reduced expression to 3.4-fold compared to controls. When only TAM was added to the culture medium, TGF-α mRNA expression increased 5.3-fold, significantly higher than with all other treatment modalities. Conclusion: We demonstrate that TGF-α mRNA expression is more efficiently upregulated by T3 than E2. Concomitant treatment with TAM had a mitigating effect on the T3 effect, while E2 induced TGF-α upregulation. Our findings show some similarities between primary culture and breast cancer cell lines, but also some important differences: a) induction of TGF-α, a mitogenic protein, by TAM; b) a differential effect of TAM that may depend on relative expression of ER α and β; and c) supraphysiological doses of T3 may induce mitogenic signals in breast cancer tissue under conditions of low circulating E2. ©2008, Editrice Kurtis.