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Aliviação do estresse por baixo pH na raíz do cultivar Micro-Tom de tomateiro via exposição gradual ou tratamento hipo-osmótico prévio: possível papel de modificações na parede celular; Alleviation of low pH stress in roots of Micro-Tom cultivar of tomato by gradual exposure or hypo-osmotic pre-treatment: possible role of modifications in the cell wall

Graças, Jonathas Pereira das
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 26/04/2013 PT
Relevância na Pesquisa
56.09%
Os solos ácidos (pH < 5,0) representam cerca de 40 % das áreas agricultáveis no mundo. Nestes solos ocorre a solubilização de formas tóxicas de alumínio que inibe o crescimento radicular. Independente da presença do Al, o baixo pH pode ser tóxico à raiz, afetando a viabilidade celular no ápice e o crescimento radicular. Há evidências de que o estresse por H+ e/ou Al³+ afetam a parede celular. Por outro lado, modificações na parede podem determinar o grau de tolerância da planta quando submetidos a estes estresses. Assim, utilizou-se de duas abordagens para investigar se possíveis modificações na parede celular melhorariam o crescimento e viabilidade celular na exposição a H+ e Al³+. Na primeira, raízes de plantas do cultivar Micro-Tom (MT) de tomateiro (Solanum lycopersicum L.), com 2 e 13 dias de desenvolvimento, foram expostas de forma direta ou gradual ao baixo pH. Na segunda abordagem, as raízes foram submetidos a um tratamento hipo-osmótico antes de serem expostas a pH 4,0 ou 4,5 + Al. Em plantas com 2 e 13 dias, a exposição gradual foi realizada alterando o pH ao longo de 12 e 24 h, respectivamente. No tratamento hipo-osmótico (priming), as plantas foram transferidas de uma solução de alta osmolaridade (150 mM) para uma com baixa osmolaridade (0...

Cálcio e boro aliviam a toxidez por H+ e Al3+ e suprimem a indução de guaiacol peroxidase em raízes do cultivar Micro-Tom de tomateiro (Solanum lycopersicum L.): possível envolvimento da parede celular; Calcium and boron alleviate H+ and Al3+ toxicity and suppress the induction of guaiacol peroxidase in roots of Micro-Tom cultivar of tomato (Solanum lycopersicum L.): possible involvement of the cell wall

Figueiredo, Lucas Diego
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 02/08/2013 PT
Relevância na Pesquisa
56.15%
Solos ácidos cobrem cerca de 30% das áreas agricultáveis do mundo. Nestes solos, geralmente ocorrem baixas concentrações de cátions como cálcio e magnésio, enquanto a acidez (pH <5,5) promove a solubilização de Al3+. A exposição de raízes a pH ácido e/ou ao Al3+ inibe o crescimento radicular, reduz a viabilidade de células do ápice, promove estresse oxidativo, e pode causar desarranjos na parede celular. Na parede, é provável que tanto o H+ como o Al3+ atuem sobre a pectina, comprometendo a sua estrutura e funcionalidade. Por outro lado, peroxidases classe III (GPOX) parecem desempenhar um papel central nas modificações da parede celular, são induzidas por H+ e Al3+ e algumas isoformas são associadas à pectina. O objetivo deste trabalho foi caracterizar as respostas radiculares da cultivar Micro-Tom de tomateiro (Solanum lycopersicum L.) à toxidez por H+ e Al3+ e avaliar a capacidade do cálcio e do boro em aliviar esta toxidez com relação à inibição do crescimento radicular, queda na viabilidade celular e alterações na atividade de GPOX. Em raízes expostas a pH 4,0, após 30 min já foi possível observar a redução na viabilidade de células do ápice, avaliada através da absorção de azul de Evans. Observou-se elevação significativa na atividade de GPOX após 2 h de tratamento a pH 4...

Fatores de virulência de Staphylococcus spp. e viabilidade celular na mastite subclínica de cabras; Virulence factors of Staphylococcus spp. and cell viability in subclinical mastitis of goats

Salaberry, Sandra Renata Sampaio
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 13/08/2014 PT
Relevância na Pesquisa
56.15%
A mastite subclínica em caprinos é causada principalmente pelo Staphylococcus spp., sendo os estafilococos coagulase negativa (SCN) os patógenos de maior ocorrência e o S. aureus, a espécie de estafilococos mais pesquisada. Dessa forma, pouco se conhece sobre a patogenicidade de SCN e outros estafilococos coagulase positiva (SCP), além do S. aureus. Também há poucos estudos sobre a variação da viabilidade celular na mastite subclínica de cabras. Assim, o objetivo do presente estudo foi determinar os fatores de virulência de adesão e produção de biofilme de estirpes de Staphylococcus spp. isoladas de amostras de leite de cabras, verificando possíveis associações com a viabilidade celular. Para realizar a colheita das amostras, primeiramente, foi efetuada um exame físico da glândula mamária, com posterior realização dos testes da caneca de fundo preto e California mastitis test (CMT). A colheita do leite foi efetuada em três alíquotas: análises microbiológicas, contagem de células somáticas (CCS) e viabilidade celular. Realizou-se a identificação, teste de antibiograma e PCR (Reação em cadeia polimerase) dos Staphylococcus spp. isolados nas amostras de leite. Os genes de virulência pesquisados no PCR foram: cna...

Optimization of temperature, sugar concentration, and inoculum size to maximize ethanol production without significant decrease in yeast cell viability

Laluce, Cecilia; Tognolli, Joao Olimpio; de Oliveira, Karen Fernanda; Souza, Crisla Serra; Morais, Meline Rezende
Fonte: Springer Publicador: Springer
Tipo: Artigo de Revista Científica Formato: 627-637
ENG
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Processo FAPESP: 05/02840-0; Aiming to obtain rapid fermentations with high ethanol yields and a retention of high final viabilities (responses), a 2(3) full-factorial central composite design combined with response surface methodology was employed using inoculum size, sucrose concentration, and temperature as independent variables. From this statistical treatment, two well-fitted regression equations having coefficients significant at the 5% level were obtained to predict the viability and ethanol production responses. Three-dimensional response surfaces showed that increasing temperatures had greater negative effects on viability than on ethanol production. Increasing sucrose concentrations improved both ethanol production and viability. The interactions between the inoculum size and the sucrose concentrations had no significant effect on viability. Thus, the lowering of the process temperature is recommended in order to minimize cell mortality and maintain high levels of ethanol production when the temperature is on the increase in the industrial reactor. Optimized conditions (200 g/l initial sucrose, 40 g/l of dry cell mass, 30 A degrees C) were experimentally confirmed and the optimal responses are 80.8 A +/- 2.0 g/l of maximal ethanol plus a viability retention of 99.0 A +/- 3.0% for a 4-h fermentation period. During consecutive fermentations with cell reuse...

Evaluation of tissue reaction, cell viability and cytokine production induced by Sealapex Plus

Gomes-Filho, João Eduardo; Gomes, Alessandra Cristina; Watanabe, Simone; Oliveira, Sandra Helena Penha de; Bernabé, Pedro Felício Estrada; Percinoto, Célio
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 329-336
ENG
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The aim of this study was to investigate the effects of mineral trioxide aggregate (MTA), Sealapex, and a combination of Sealapex and MTA (Sealapex Plus) on the reaction of subcutaneous connective tissue of rats, and on cell viability and cytokine production in mouse fibroblasts. The tissue reaction was carried out with dentin tubes containing the materials implanted in the dorsal connective tissue of rats. The histological analysis was performed after 7 and 30 days. Millipore culture plate inserts with polyethylene tubes filled with materials were placed into 24-well cell culture plates with mouse fibroblasts to evaluate the cell viability by MTT assay. ELISA assays were also performed after 24 h of exposure of the mouse fibroblasts to set material disks. Histopathologic examination showed Von Kossa-positive granules that were birefringent to polarized light for all the studied materials at the tube openings. No material inhibited the cell viability in the in vitro test. It was detected IL-6 production in all root-end filling materials. MTA and Sealapex Plus induced a slight raise of mean levels of IL-1β. The results suggest that Sealapex Plus is biocompatible and stimulates the mineralization of the tissue.

A hydrogel scaffold that maintains viability and supports differentiation of dental pulp stem cells

Cavalcanti, Bruno N.; Zeitlin, Benjamin D.; Nör, Jacques E.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 97-102
ENG
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Objectives: The clinical translation of stem cell-based Regenerative Endodontics demands further development of suitable injectable scaffolds. Puramatrix™ is a defined, self-assembling peptide hydrogel which instantaneously polymerizes under normal physiological conditions. Here, we assessed the compatibility of Puramatrix™ with dental pulp stem cell (DPSC) growth and differentiation. Methods: DPSC cells were grown in 0.05-0.25% Puramatrix™. Cell viability was measured colorimetrically using the WST-1 assay. Cell morphology was observed in 3D modeling using confocal microscopy. In addition, we used the human tooth slice model with Puramatrix™ to verify DPSC differentiation into odontoblast-like cells, as measured by expression of DSPP and DMP-1. Results: DPSC survived and proliferated in Puramatrix™ for at least three weeks in culture. Confocal microscopy revealed that cells seeded in Puramatrix™ presented morphological features of healthy cells, and some cells exhibited cytoplasmic elongations. Notably, after 21 days in tooth slices containing Puramatrix™, DPSC cells expressed DMP-1 and DSPP, putative markers of odontoblastic differentiation. Significance: Collectively, these data suggest that self-assembling peptide hydrogels might be useful injectable scaffolds for stem cell-based Regenerative Endodontics. © 2012 Academy of Dental Materials.

Guided implant surgery: What is the influence of this new technique on bone cell viability?

Dos Santos, Pâmela Letícia; Queiroz, Thallita Pereira; Margonar, Rogério; Gomes de Souza Carvalho, Abrahão Cavalcante; Okamoto, Roberta; De Souza Faloni, Ana Paula; Garcia Júnior, Idelmo Rangel
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 505-512
ENG
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Purpose: To evaluate the effect of implant osteotomy on immediate bone cell viability, comparing guided surgery for implant placement with the classic drilling procedure. Materials and Methods: For this study, 20 rabbits were used. The animals were divided into a guided surgery group (GG) and a control group (CG) and were then divided into 4 subgroups - subgroups 1, 2, 3, and 4 - corresponding to drills used 10, 20, 30, and 40 times, respectively. All animals received 5 osteotomies in each tibia, by use of the classic drilling procedure in one tibia and guided surgery in the other tibia. The osteotomized areas were removed and processed immunohistochemically for detection of osteocalcin, receptor activator of nuclear factor κB ligand (RANKL), osteoprotegerin (OPG), and caspase 3. Results: Immunohistochemical analysis showed that osteocalcin expression was initially higher in the CG and remained constant after drill reutilization. Although the expressions of RANKL and OPG were not statistically different for the GG and CG, the RANKL/OPG ratio tended to be higher for the GG. Moreover, caspase 3 expression was elevated in the GG, proportionally to the number of osteotomies, indicating an increase in the apoptosis index in the GG. Conclusions: The classic drilling procedure is more favorable to cell viability than guided surgery.© 2013 American Association of Oral and Maxillofacial Surgeons.

Efeitos dos anestésicos locais associados a carreadores na modulação de mediadores inflamatórios, viabilidade celular e apoptose; Effects of local anesthetics associated to carriers on the modulation of inflammatory mediators, cell viability and apoptosis

Luiz Eduardo Nunes Ferreira
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 13/02/2014 PT
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66.15%
A associação de anestésicos locais a sistemas de liberação modificados tem sido proposta visando prolongar o efeito anestésico e reduzir a citotoxicidade e indução da apoptose sobre diversos tipos celulares. Novas formulações anestésicas produziram uma baixa toxicidade sistêmica e maior duração da anestesia, porém também foram observados efeitos adversos como o aparecimento de processos inflamatórios. Desta maneira, o objetivo do estudo foi comparar os efeitos dos anestésicos locais livres em relação aos associados a carreadores sobre a modulação dos mediadores IL-6, IL1-α, IL-8, TNF-α, IL-10 e PGE2, além de sua ação sobre a viabilidade celular e indução da apoptose. Células HaCaT e FGH em cultura foram expostas a diferentes concentrações dos anestésicos bupivacaína, lidocaína e ropivacaína livres ou associados a lipossomos ou HP-β-CD, por 6h e 24h. A quantificação das citocinas e PGE2 foi realizada utilizando o teste de ELISA de captura. A viabilidade celular foi quantificada pelo método do XTT e avaliada qualitativamente por microscopia de fluorescência (LIVE/DEAD). A indução da apoptose foi estimada através de citometria de fluxo. A lidocaína associada com carreadores aumentou a liberação de citocinas...

Determination and modeling of yeast viability under stress conditions

Coutinho, J. A. P.; Coelho, M. A. Z.; Ferreira, E. C.; Belo, Isabel
Fonte: Elsevier Publicador: Elsevier
Tipo: Conferência ou Objeto de Conferência
Publicado em //2004 ENG
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In this work the effect of the total pressure and the oxygen concentration in the gas phase on the growth and viability of Saccharomyces cerevisiae is studied. Cell viability was measured staining with methylene blue and assessed using digital image processing. A model that takes into account cell viability was developed and used for the correlation of the measured data. A dependence of the death rate, KD, with the total pressure and the oxygen concentration is proposed. Its behavior indicates that opposing effects between oxygen availability and baric and oxidative stresses are present on the system. It is shown that the proposed model can, with this extra parameter, successfully describe not only the traditional X-P-S evolution but also the ratio of viable cells with time.; Brasil. Ministério da Educação. Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Brasil. Ministério da Ciência e Tecnologia. Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq).

Assessment of yeast viability under hyperbaric conditions through a modeling approach

Coutinho, J. A. P.; Belo, Isabel; Ferreira, E. C.; Coelho, M. A. Z.
Fonte: Wiley Interscience Publicador: Wiley Interscience
Tipo: Artigo de Revista Científica
Publicado em /08/2005 ENG
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The effect of pressure (0.1–1.5 MPa) and oxygen concentration on the growth and viability of Saccharomyces cerevisiae was studied. Cell viability was assessed through the Methylene Blue staining method and the percentages of viable and non-viable cells were estimated using digital image processing. A model taking into account cell viability was developed and used to describe the measured data. The model reveals the opposing effects between oxygen availability and the baric and oxidative stresses present on the system and can successfully describe not only the traditional biomass–product–substrate (X–P–S) volution but also the ratio of viable cells with time. It is shown that cell viability in general is not constant during the experiments but strongly depends on the environment.

Macroporous hydroxyapatite scaffolds for bone tissue engineering applications : physicochemical characterization and assessment of rat bone marrow stromal cell viability

Oliveira, Joaquim M.; Silva, S. S.; Malafaya, P. B.; Rodrigues, Márcia T.; Kotobuki, Noriko; Hirose, Motohiro; Gomes, Manuela E.; Mano, J. F.; Ohgushi, H.; Reis, R. L.
Fonte: Wiley Publicador: Wiley
Tipo: Artigo de Revista Científica
Publicado em //2009 ENG
Relevância na Pesquisa
66%
In this work, a new methodology is reported for developing hydroxyapatite (HA) scaffolds using an organic sacrifice template. The novelty of work consists of possibility of obtaining porous and highly interconnected scaffolds mimicking the sacrificial component. Our purpose consisted of evaluating the physicochemical properties of the HA scaffolds by means of Fourier transform infra-red spectroscopy, X-ray diffraction analysis, and scanning electron microscopy (SEM) attached with an Xray detector. The HA scaffolds obtained possess a porosity of !70%, and macropores diameter in the range of 50–600 lm. In contrast, results regarding the microcomputed tomography analysis have demonstrated both high pore uniformity and interconnectivity across the scaffolds. The compressive strength of the HA scaffolds was found to be 30.2 6 6.0 MPa. Bioactivity of the HA scaffolds was assessed by immersion into a simulated body fluid solution, in vitro. SEM observations have showed a deposition of apatite on the surface of the HA scaffolds, with a ‘‘cauliflower- like’’ morphology after 1 day, and tend to be more pronounced with the immersion time. The changes in calcium and phosphorus concentration were monitored by inductively-coupled plasma optical emission spectrometry. Cytotoxicity of the HA scaffolds was preliminarily investigated by carrying direct observation of mouse fibroblasts cells (L929 cell-line) death in the inverted microscope...

Carboxymethylchitosan/poly (amidoamine) dendrimer nanoparticles in central nervous systems-regenerative medicine : effects on neuron/glial cell viability and internalization efficiency

Salgado, A. J.; Oliveira, Joaquim M.; Pirraco, Rogério; Pereira, Vitor H.; Fraga, J. S.; Marques, A. P.; Neves, N. M.; Mano, J. F.; Reis, R. L.; Sousa, Nuno
Fonte: WILEY-VCH Publicador: WILEY-VCH
Tipo: Artigo de Revista Científica
Publicado em /10/2010 ENG
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The applicability of CMCht/PAMAM dendrimer nanoparticles for CNS applications was investigated. AFM and TEM observations revealed that the nanoparticles possessed a nanosphere- like shape with a size from 22.0 to 30.7 nm. The nanoparticles could be bound to fluorescent-probe FITC for tracing purposes. Post-natal hippocampal neurons and cortical glial cells were both able to internalize the FITC-labeled CMCht/PAMAM dendrimer nanoparticles with high efficiency. The percentage of positive cells internalizing the nanoparticles varied, reaching a peak after 48 h of incubation. Further experiments for periods up to 7 d revealed that the periodical addition of FITC-labelled CMCht/ PAMAM dendrimer nanoparticles was needed to maintain the overall percentage of cells internalizing them. Finally, it was also observed that cell viability was not significantly affected by the incubation of dendrimer nanoparticles.

Methylmercury intoxication activates nitric oxide synthase in chick retinal cell culture

Herculano,A.M.; Crespo-López,M.E.; Lima,S.M.A.; Picanço-Diniz,D.L.W.; Nascimento,J.L.M. Do
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2006 EN
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The visual system is a potential target for methylmercury (MeHg) intoxication. Nevertheless, there are few studies about the cellular mechanisms of toxicity induced by MeHg in retinal cells. Various reports have indicated a critical role for nitric oxide synthase (NOS) activation in modulating MeHg neurotoxicity in cerebellar and cortical regions. The aim of the present study is to describe the effects of MeHg on cell viability and NOS activation in chick retinal cell cultures. For this purpose, primary cultures were prepared from 7-day-old chick embryos: retinas were aseptically dissected and dissociated and cells were grown at 37ºC for 7-8 days. Cultures were exposed to MeHg (10 µM, 100 µM, and 1 mM) for 2, 4, and 6 h. Cell viability was measured by MTT method and NOS activity by monitoring the conversion of L-[H³]-arginine to L-[H³]-citrulline. The incubation of cultured retina cells with 10 and 100 µM MeHg promoted an increase of NOS activity compared to control (P < 0.05). Maximum values (P < 0.05) were reached after 4 h of MeHg incubation: increases of 81.6 ± 5.3 and 91.3 ± 3.7%, respectively (data are reported as mean ± SEM for 4 replicates). MeHg also promoted a concentration- and time-dependent decrease in cell viability...

In vitro modulation of Bcl-2 levels in small cell lung cancer cells: effects on cell viability

Santos,A.O.; Pereira,J.P.; Pedroso de Lima,M.C.; Simões,S.; Moreira,J.N.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2010 EN
Relevância na Pesquisa
55.98%
Small cell lung cancer (SCLC) is an aggressive disease, representing 15% of all cases of lung cancer, has high metastatic potential and low prognosis that urgently demands the development of novel therapeutic approaches. One of the proposed approaches has been the down-regulation of BCL2, with poorly clarified and controversial therapeutic value regarding SCLC. The use of anti-BCL2 small interfering RNA (siRNA) in SCLC has never been reported. The aim of the present study was to select and test the in vitro efficacy of anti-BCL2 siRNA sequences against the protein and mRNA levels of SCLC cells, and their effects on cytotoxicity and chemosensitization. Two anti-BCL2 siRNAs and the anti-BCL2 G3139 oligodeoxynucleotide (ODN) were evaluated in SCLC cells by the simultaneous determination of Bcl-2 and viability using a flow cytometry method recently developed by us in addition to Western blot, real-time reverse-transcription PCR, and cell growth after single and combined treatment with cisplatin. In contrast to previous reports about the use of ODN, a heterogeneous and up to 80% sequence-specific Bcl-2 protein knockdown was observed in the SW2, H2171 and H69 SCLC cell lines, although without significant sequence-specific reduction of cell viability...

Assessment of viability of sperm cells of Litopenaeus vannamei on cryopreservation

Uberti,Marcela Fornari; Vieira,Felipe do Nascimento; Salência,Helena Ragibo; Vieira,Genyess da Silva; Vinatea,Luis Alejandro
Fonte: Instituto de Tecnologia do Paraná - Tecpar Publicador: Instituto de Tecnologia do Paraná - Tecpar
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2014 EN
Relevância na Pesquisa
55.96%
Aiming at assessing the cryopreservation potential of Litopenaeus vannamei sperm cells, 74 spermatophores were manually extracted from the sexually mature individuals. After the toxicity test to define the cryoprotectant concentration, suspensions of spermatic cells were cryopreserved in the groups in freezing solutions comprising different cryoprotectants such as dimethyl sulfoxide (DMSO) and ethylene glycol (EG) at 10% concentration. Each treatment was divided in subgroups for storage in liquid nitrogen during 0, 30, 60 and 90 days, in triplicate. After thawing at 25ºC for 40 seconds, cell viability in the suspensions was analyzed under the microscope in eosin-nigrosin stain and flow cytometry. There were no significant differences between the cryoprotectants used. For all the treatments, lower and higher mortalities occurred in the 0 and 90 days, respectively. By applying the eosin-nigrosin technique, lower and higher mortalities were 23.17 and 82.11% for DMSO and 29.94 and 83.72% for EG, while the flow cytometry registered mortalities of 2.42 and 55.13% for DMSO and 0.90 and 55.56% for EG. The Spearman correlation coefficient indicated a positive correlation (R=0.91) between the two techniques used. It was concluded that there was a decrease in cell viability within a longer cryopreservation time.

Effects of biosurfactants on the viability and proliferation of human breast cancer cells

Duarte, Cristina; Gudiña, Eduardo J.; Lima, Cristóvão F.; Rodrigues, L. R.
Fonte: Springer Publicador: Springer
Tipo: Artigo de Revista Científica
Publicado em //2014 ENG
Relevância na Pesquisa
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Biosurfactants are molecules with surface activity produced by microorganisms that can be used in many biomedical applications. The anti-tumour potential of these molecules is being studied, although results are still scarce and few data are available regarding the mechanisms underlying such activity. In this work, the anti-tumour activity of a surfactin produced by Bacillus subtilis 573 and a glycoprotein (BioEG) produced by Lactobacillus paracasei subsp. paracasei A20 was evaluated. Both biosurfactants were tested against two breast cancer cell lines, T47D and MDA-MB-231, and a non-tumour fibroblast cell line (MC-3T3-E1), specifically regarding cell viability and proliferation. Surfactin was found to decrease viability of both breast cancer cell lines studied. A 24h exposure to 0.05gl-1 surfactin led to inhibition of cell proliferation as shown by cell cycle arrest at G1 phase. Similarly, exposure of cells to 0.15gl-1 BioEG for 48h decreased cancer cells' viability, without affecting normal fibroblasts. Moreover, BioEG induced the cell cycle arrest at G1 for both breast cancer cell lines. The biosurfactant BioEG was shown to be more active than surfactin against the studied breast cancer cells. The results gathered in this work are very promising regarding the biosurfactants potential for breast cancer treatment and encourage further work with the BioEG glycoprotein.

Effects of cigarette smoke and nicotine on cell viability, migration and myofibroblastic differentiation

Smith, P. C.; Cáceres, M.; Martínez Winkler, Jorge; Arancibia, R.; Silva, D.
Fonte: John Wiley & Sons A/S Publicador: John Wiley & Sons A/S
Tipo: Artículo de revista
EN
Relevância na Pesquisa
56.08%
Artículo de publicación ISI.; Background and Objective: Several studies have analysed the role of nicotine as a prominent agent affecting wound repair in smokers. However, tobacco smoke contains several components that may alter gingival wound healing. The present study aimed to analyse the roles of cigarette smoke condensate (CSC) and nicotine on cell viability, cell migration/invasion and myofibroblastic differentiation using primary cultures of human gingival fibroblasts. Material and Methods: To compare the effects of CSC and nicotine, gingival fibroblasts were stimulated with CSC (0.4–500 lg/mL) and the corresponding nicotine concentrations (0.025–32 lg/mL) present in research cigarettes (1R3F). Cell viability was evaluated through the MTS assay. Cell migration and invasion were assessed through scratch wound assays, collagen nested matrices and transwell migration. a-Smooth muscle actin production was evaluated by western blotting. Results: Cigarette smoke condensate at 50 lg/mL induced a moderate increase in cell viability, whereas the corresponding nicotine concentration (3.2 lg/mL) did not produce this response. Cigarette smoke condensate at 250 lg/mL, but not nicotine at 16 lg/mL (the corresponding nicotine concentration)...

Rutin increases neural crest stem cell survival against damage caused by aflatoxin B1; Rutina aumenta a sobrevivência das células-tronco da crista neural e atua contra danos causados pela aflatoxina B1

Nones, Jader; Universidade Federal de Santa Catarina; Nones, Janaína; Universidade Federal de Santa Catarina; Trentin, Andrea; Universidade Federal de Santa Catarina
Fonte: Universidade Federal de Santa Catarina Publicador: Universidade Federal de Santa Catarina
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Formato: application/pdf
Publicado em 29/09/2015 ENG
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http://dx.doi.org/10.5007/2175-7925.2015v28n4p1The neural crest (NC) corresponds to a collection of multipotent and oligopotent progenitors endowed with both neural and mesenchymal potential. The derivatives of the NC at the trunk level include neurons and glial cells of the peripheral nervous system, melanocytes, smooth muscle cells and some endocrine cells. The present work investigated, for the first time, the influence of aflatoxin B1 (AFB1) and the flavonoid rutin on the survival and proliferation of NC and NC-derived melanocytes. Quail NC cell cultures were treated with AFB1 (30 μM) and/or rutin (20 μM) for 6 days. Cell viability was assessed by MTT and trypan blue analyses and cell proliferation by BrdU staining. Melanocytes were identified by immunocytochemistry against the melanocyte-specific cellular marker MelEM. The AFB1 treatment decreased both NC cell viability and proliferation. The total number of MelEM-positive cells was also reduced after this treatment, an effect partially prevented by the addition of rutin. On the other hand, rutin added alone did not influence the NC cell population. Our results demonstrated that rutin increases the survival of the NC after damage caused by AFB1. However, additional studies are needed to better understand the mechanisms involved in AFB1 and rutin interactions.; http://dx.doi.org/10.5007/2175-7925.2015v28n4p1A crista neural (CN) corresponde a um conjunto de células progenitoras multi e oligopotentes dotadas com potenciais neural e mesenquimal. Os derivados da CN incluem neurônios e células gliais do sistema nervoso periférico...

Evaluation of two human dental pulp stem cell cryopreservation methods

Munévar,Juan C; Gutiérrez,Nicole; Jiménez,Nury T; Lafaurie,Gloria I
Fonte: Acta Odontológica Latinoamericana Publicador: Acta Odontológica Latinoamericana
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2015 EN
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Dental pulp is a promising source of mesenchymal stem cells for use in cell therapy and regenerative medicine. Methods for storing stem cells with minimum compromise of cell viability, differentiation capacity and function should be developed for clinical and research applications. The aim of this study was to evaluate whether human dental pulp stem cells (hDPSCs) isolated and cryopreserved for 1, 7 and 30 days maintain viability and expression of specific stem cell markers. Human dental pulp stem cells were isolated from 23 healthy patients aged 18 to 31 years. Dental pulp was enzymatically dissociated, and CD105+ cells were separated using the Miltenyi™ system. The hDPSCs were cryopreserved using the Kamath and Papaccio methods. Post-cryopreservation viability was measured by flow cytometry (7AAD) and by the expression of the phenotype markers CD105+/ CD73+, CD34-/CD45-. The Papaccio method showed greater cell viability for cells that had been frozen for 30 days (59.5%) than the Kamath method (56.2%), while the Kamath method provided better results for 1 day (65.5%) and 7 days (56%). Post-cryopreservation expression of the markers CD105+/CD34- was greater after 1 and 7 days with the Kamath method and CD105+/CD45- were expressed after all 3 cryopreservation times. There was greater expression of CD73+ in the hDPSCs after 1 and 7 days with the Kamath method...

A cell viability assay to determine the cytotoxic effects of water contaminated by microbes

Prinsloo,Suranie; Pieters,Rialet; Bezuidenhout,Carlos C.
Fonte: South African Journal of Science Publicador: South African Journal of Science
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2013 EN
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Many South Africans do not have access to safe drinking water, so they have no alternative but to use water from contaminated sources that poses a health hazard. This poor state of affairs appears to be deteriorating. In order to distinguish safe from unsafe sources, the aim of this study was to adapt the well-known MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay into a simple and efficient method to screen the suitability of drinking water without needing to know the nature of any possible contamination. This modified assay presents an immediate and reliable answer to whether water is potable without recourse to standard chemical and microbiological water-quality tests. The MTT assay was used here for the first time to test the effects of microbes, and not chemical contaminants as is traditionally the case, on the viability of human duodenum cells exposed to water samples of interest. Filtered tap water and water from a borehole, for example, had limited adverse effects on cell viability. Cell viability decreased greatly after exposure to dam, treated sewage and river water which confirmed the value of the assay as a screening tool.