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Pilares protéticos de dimensão horizontal discrepante: biomecânica e desempenho clínico

Rocha, Salomão
Fonte: Universidade de Coimbra Publicador: Universidade de Coimbra
Tipo: Tese de Doutorado
Português
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Introdução A utilização de pilares de cicatrização ou componentes protéticos de diâmetro inferior ao da plataforma do implante, conceito conhecido como platform switching (PS), tem sido associado a uma menor remodelação óssea marginal. Ainda que existam vários trabalhos publicados que sustentam esta teoria, todas as revisões sistemáticas são unânimes em considerar a necessidade de mais estudos clínicos prospetivos controlados e randomizados, com condições comparáveis entre os grupos teste e controlo e com períodos de seguimento de pelo menos 5 anos. O trabalho apresentado nesta tese teve duas linhas de investigação: uma foi a realização de um estudo numérico pelo método dos elementos finitos (MEF), para simular o comportamento dinâmico e estático de um implante osteointegrado na região posterior mandibular e reabilitado com pilares convencionais e pilares de plataforma horizontal discrepante, e a segunda, um estudo clínico prospetivo randomizado, cujo objetivo foi avaliar a eficácia de implantes reabilitados com coroas unitárias cimentadas sobre pilares protéticos coincidentes (PM) ou sobre pilares protéticos com platform switching, no sector posterior mandibular. Materiais e métodos No estudo numérico avaliou-se o comportamento biomecânico de um implante Camlog® Screw-Line 4.3x13 mm...

Análise de estruturas de concreto sob o efeito do tempo: uma abordagem consistente com consideração da viscoelasticidade, da plasticidade, da fissuração, da protensão e de etapas construtivas.; Concrete structures analysis under the time effects: an efficient and accurate approach qhich takes into account the viscoelasticity, the plasticity, the cracking, the prestressing and constructions by stages.

Santos, Hudson Chagas dos
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 25/05/2006 Português
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Apresenta-se neste trabalho uma metodologia consistente e eficiente para análise de estruturas de concreto sob o efeito do tempo. A metodologia exposta é baseada no Método dos Elementos Finitos (MEF). É mostrado como se analisar estruturas de concreto através do MEF, considerando na equação constitutiva dos elementos, os fenômenos viscoelásticos. A solução para este problema, denominado análise incremental quase-estática, pode ser obtida determinando os campos de tensões, deslocamentos e deformações num dado instante a partir de seus valores conhecidos no instante anterior. Aqui, efetua-se a análise incremental através de um Algoritmo de Integração de Tensões (AIT) com a ajuda de uma rotina computacional baseada no MEF. A Função de Fluência utilizada neste trabalho, além de ser muito eficiente segundo uma metodologia através do MEF, permite facilmente o seu ajuste a quaisquer dados experimentais, ou mesmo aproximar qualquer função de fluência de normas ou códigos. Outra característica crucial é que a integração das tensões não exige o armazenamento computacional de todas as variáveis dependentes do histórico de tensão em um determinado instante, facilitando significantemente a análise ou a retro-análise de estruturas de concreto. Vale ressaltar que ao longo do texto são feitas algumas discussões e comparações do emprego da Função de Fluência proposta com a função da NBR-6118:2003. Também é apresentada uma outra consistente metodologia para a análise de um elemento finito de cabo com escorregamento...

Identificação de marcadores de pluripotência em células-tronco embrionárias e embriões suínos; Identification of pluripotency markers in swine embryonic stem cells and embryos

Barros, Flavia Regina Oliveira de
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 22/01/2009 Português
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Células-tronco embrionárias (CTE) são importantes para estudos de desenvolvimento embrionário, diferenciação e manipulação genética. Além disso, essas células podem ser utilizadas na terapia celular e organogênese in vitro. Na pesquisa sobre terapia celular a partir de CTE oriundas de embriões humanos, considerações éticas, morais e religiosas têm sido feitas por pesquisadores e leigos. Portanto, um modelo animal como o suíno (Sus scrofa) será bastante válido por transpor tais barreiras, visto que o suíno possui parâmetros fisiológicos semelhantes aos humanos. Apesar do alto potencial biomédico das CTE, existem dificuldades na manutenção da pluripotência in vitro dessas células em suínos. Portanto, estudos que visam elucidar os mecanismos de manutenção da pluripotência de CTE in vitro são necessários para viabilizar o cultivo dessas células. Os objetivos do presente estudo foram (1) isolar células-tronco embrionárias suínas a partir de blastocistos produzidos in vitro e in vivo; (2) comparar dois sistemas de cultivo in vitro das massas celulares internas (MCI) isoladas, MEF ou Matrigel e (3) identificar e comparar a expressão dos fatores de transcrição Nanog, Sox2 e FoxD3 em CTE e blastocistos suínos produzidos in vitro e in vivo. Assim...

Verificação dos índices de resistência do Streptococcus pneumoniae e caracterização genotípica das cepas resistentes a eritromicina; Verification of streptococcus pneumoniae resistance indices and genotypical characterization of the erythromycin resistant strains

Weber, Fabio Tito
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Dissertação Formato: application/pdf
Português
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O Streptococcus pneumoniae é responsável por altos índices de morbidade e mortalidade pelo mundo. No início do século XX os percentuais de morte causados por essa bactéria atingiram mais de 80%. Com o surgimento da antibioticoterapia, principalmente com o uso da penicilina, o combate ao pneumococo tornou-se mais efetivo. A partir da década de 1980, o combate a essa bactéria começou a ser mais difícil, devido ao aumento da resistência pneumocócica aos antimicrobianos. No Brasil e, de forma geral, no mundo todo são verificados percentuais crescentes de resistência pneumocócica. Tais percentuais variam de um país para outro e, até mesmo, dentro de um mesmo país significativamente. Dessa forma, faz-se necessário o monitoramento desses índices de resistência para se ter conhecimento da efetividade dos antimicrobianos comumente usados contra o pneumococo. A resistência do pneumococo tem origem cromossomal. No caso da eritromicina, os genes de resistência são denominados erm(B) e mef(A/E). Como ocorre com os percentuais de resistência, a prevalência dos genes citados também muda de acordo com a região pesquisada. Assim como a verificação da resistência, é importante a pesquisa da origem da resistência antimicrobiana...

Association of riboflavin in whey protein hydrogels produced through application of moderate electric field and cold induced gelation

Pereira, Ricardo; Altinok, Emir; Rodrigues, Rui M.; Ramos, Óscar L.; Malcata, F. X.; Ferrari, Giovanna; Teixeira, J. A.; Vicente, A. A.
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Conferência ou Objeto de Conferência
Publicado em 15/10/2014 Português
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Protein hydrogels are one of the most convenient and widely used matrix in food applications. Recently, cold gelation ability of whey protein isolate (WPI) is taking interest in protection and delivery of value-added bioactive compounds through micro and nano-association techniques. This study aims to combine an electro-heating treatment at moderate electric fields (MEF) together with cold gelation ability of whey proteins in order to reduce size of protein aggregates at nano-scale and improve association efficiency of riboflavin. Divalent iron cation assisted cold gelation of electro-heated WPI and effects of MEF on the produced hydrogels were reported and encouraged during this experimental research. Particle size was characterized, through dynamic light scattering. While spectrofluorimetric analyses were performed in order to examine the effects of MEF and cold induced gelation on the association of riboflavin within WPI hydrogel network structure. Under MEF application smaller sized particles were produced and riboflavin association efficiencies ranged from 40 to 60%. Results also show that MEF treatment allowed producing WPI nano-hydrogels with associated riboflavin less susceptible to light oxidation. This novel approach that combines electro-heating treatment together with cold gelation can be used to design and develop entirely biodegradable whey protein-based gels as potential devices for controlled release of riboflavin. MEF can be used to improve or create novel applications not only in food and bioprocessing industries...

Influence of moderate electric fields on the formation and properties of whey protein network structures

Pereira, Ricardo; Teixeira, J. A.; Vicente, A. A.
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Conferência ou Objeto de Conferência
Publicado em /09/2012 Português
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Gelation plays a major role in enhancing textural properties of foods (substituting fats), once it provides unique textural properties that gives pleasant mouth feel, and enables holding water and other ingredients in one matrix. The general objective of this study was to assess the effects of MEF on properties of whey protein hydrogels. Results show that MEF originated a weaker gel structure than conventional heating treatment. Significant decreases in storage and loss moduli were observed upon application of MEF. Aggregation and cross-linking patterns of whey proteins during MEF was not sufficiently high to form a true elastic gel network. As conclusion, MEF may provide a novel method for production of a protein matrix with distinctive properties. However a larger body of research is needed to fully address the role of the MEF on protein electrostatics and protein-protein interactions.

Avaliação do impacto do módulo NUT do programa multimédia "Alimentação, modelo estético feminino e meios de comunicação", nas variáveis comportamento alimentar e conhecimento nutricional : estudo integrado no projeto "Avaliação da eficácia do programa Alimentação modelo estético feminino e meios de comunicação", na população portuguesa

Vieira, Catarina Alexandra Fernandes
Fonte: Universidade de Lisboa Publicador: Universidade de Lisboa
Tipo: Dissertação de Mestrado
Publicado em //2012 Português
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Tese de mestrado, Psicologia (Secção de Psicologia Clínica e da Saúde - Núcleo de Psicologia da Saúde e da Doença), Universidade de Lisboa, Faculdade de Psicologia, 2012; Este estudo integra-se num projeto que pretendeu avaliar, numa amostra de adolescentes portugueses, o impacto de um programa multimédia, intitulado Alimentação, modelo estético feminino e meios de comunicação – como formar alunos com juízo crítico no ensino secundário, composto por módulos: Modelo estético feminino (MEF), O modelo estético feminino nos media (ML) e Alimentação e Nutrição (NUT) (Francisco, Custódio, Jesus, Martins, Vieira, & Barros, 2012). Especificamente neste estudo, fez-se a aplicação do módulo NUT, e avaliou-se o seu impacto em comparação com a aplicação conjunta dos módulos MEF+ML, em relação a variáveis relacionadas com comportamento alimentar e conhecimento nutricional. A amostra total foi constituída por 40 alunos do 8º ano de escolaridade, distribuídos por duas condições experimentais: MEF+ML e NUT. Em cada condição experimental existiram 3 momentos de recolha de informação, nos quais foi preenchido um conjunto de questionários. O impacto do módulo NUT, em destaque neste trabalho...

Pharmacodynamics of mefloquine and praziquantel combination therapy in mice harbouring juvenile and adult Schistosoma mansoni

El-Lakkany,Naglaa Mohamed; el-Din,Sayed Hassan Seif; Sabra,Abdel-Nasser Abdel-Aal; Hammam,Olfat Ali
Fonte: Instituto Oswaldo Cruz, Ministério da Saúde Publicador: Instituto Oswaldo Cruz, Ministério da Saúde
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/11/2011 Português
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Praziquantel (PZQ) is currently the only drug widely used for the treatment of schistosomiasis, but the antimalarial drug mefloquine (Mef) possesses interesting antischistosomal properties. Combination therapy with these two drugs has been suggested as a strategy for transmission control, as PZQ is active against adult worms and Mef is active against schistosomula. To examine the efficacy of combination therapy, Schistosoma mansoni-reinfected mice were separated into seven groups: untreated (I), treated with PZQ in doses of 200 mg/kg (II) or 1,000 mg/kg (III), treated with Mef in doses of 200 mg/kg (IV) or 400 mg/kg (V); each dose was divided equally and given on two consecutive days. Group VI was treated with doses of PZQ + Mef as in groups II and IV, respectively, while group VII was treated with PZQ + Mef as in groups III and V, respectively. PZQ + Mef at the reduced doses of 200 mg/kg each enhanced the therapeutic efficacy over the reduced PZQ dose alone as shown by a very high reduction in the total numbers of mature worms (95% vs. 49%), immature worms (96% vs. 29%) and the complete eradication of immature females, mature females and immature eggs. The reduction in worm burden was associated with the healing of hepatic granulomatous lesions and the normalisation of all liver enzymes. Therefore...

Força de mordida em crianças com mantenedor de espaço funcional na fase da dentadura mista inicial

Jacinto-Gonçalves,Suzane Rodrigues; Gavião,Maria Beatriz Duarte
Fonte: Dental Press Editora Publicador: Dental Press Editora
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2009 Português
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OBJETIVO: verificar a influência do mantenedor de espaço funcional (MEF) na força muscular em crianças com perda prematura de molares decíduos na fase inicial da dentadura mista (5,5 a 6,5 anos de idade) com oclusão normal, considerando-se o padrão facial. MÉTODOS: a amostra foi constituída por dois grupos: Grupo MEF (n = 15), com perda precoce de pelo menos um molar decíduo; e Grupo Controle (n = 16). Determinou-se a força de mordida máxima (FM) com um tubo transmissor pressurizado, conectado a um circuito eletrônico analógico/digital antes (t0), um mês (t1) e 6 meses (t6) após a instalação do mantenedor. O padrão facial foi determinado pelo índice de Jarabak (FHR). Os dados foram analisados pela estatística descritiva, análise de variância para medidas repetidas, teste t e correlação de Pearson. RESULTADOS:a FM foi significativamente menor em t0 e t1 para o Grupo MEF em relação ao Controle. Em t6 não houve diferença. Os dois grupos apresentaram a FM significativamente maior em t6, em relação a t0, mas o percentual de variação para o Grupo MEF foi significativamente maior. Os valores de FHR não se correlacionaram com a FM, não ocorrendo diferença entre os tipos faciais intragrupos. Os dolicofaciais do Grupo MEF apresentaram a FM significativamente menor que os do Grupo Controle...

Molecular Epidemiology of Erythromycin Resistance in Streptococcus pneumoniae Isolates from Blood and Noninvasive Sites

Amezaga, Maria Rosario; Carter, Philip E.; Cash, Phillip; McKenzie, Hamish
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /09/2002 Português
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Erythromycin-resistant isolates of Streptococcus pneumoniae from blood cultures and noninvasive sites were studied over a 3-year period. The prevalence of erythromycin resistance was 11.9% (19 of 160) in blood culture isolates but 4.2% (60 of 1,435) in noninvasive-site isolates. Sixty-two of the 79 resistant isolates were available for study. The M phenotype was responsible for 76% (47 of 62) of resistance, largely due to a serotype 14 clone, characterized by multilocus sequence typing as ST9, which accounted for 79% (37 of 47) of M phenotype resistance. The ST9 clone was 4.8 times more common in blood than in noninvasive sites. All M phenotype isolates were PCR positive for mef(A), but sequencing revealed that the ST9 clone possessed the mef(A) sequence commonly associated with Streptococcus pyogenes. All M phenotype isolates with this mef(A) sequence also had sequences consistent with the presence of the Tn1207.1 genetic element inserted in the celB gene. In contrast, isolates with the mef(E) sequence normally associated with S. pneumoniae contained sequences consistent with the presence of the mega insertion element. All MLSB isolates carried erm(B), and two isolates carried both erm(B) and mef(E). Fourteen of the 15 MLSB isolates were tetracycline resistant and contained tet(M). However...

Comparison of PCR assay with bacterial culture for detecting Streptococcus pneumoniae in middle ear fluid of children with acute otitis media.

Virolainen, A; Salo, P; Jero, J; Karma, P; Eskola, J; Leinonen, M
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /11/1994 Português
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We have studied etiological diagnosis of acute otitis media (AOM) by comparing a newly developed pneumococcal PCR for Streptococcus pneumoniae to bacterial culture with 180 middle ear fluid (MEF) samples of 125 children with 125 episodes of AOM. For pneumococcal PCR assay, DNA from MEF samples was extracted by phenol-chloroform. The outer primers used amplified a 348-bp region of the pneumolysin gene, and the inner primers amplified a 208-bp region. S. pneumoniae was cultured in 33 (18%) samples, and pneumolysin PCR was positive for 51 (28%) of 180 MEF samples. Only 2 of 21 PCR-positive, S. pneumoniae culture-negative samples were positive for other otitis pathogens. By combining MEF culture and PCR results, 54 (30%) of 180 MEF samples had evidence of pneumococcal etiology. In conclusion, pneumolysin PCR is a sensitive and specific new method to study pneumococcal involvement in MEF samples of children with AOM.

Acquired Macrolide Resistance Genes in Pathogenic Neisseria spp. Isolated between 1940 and 1987

Cousin, Sydney; Whittington, William L. H.; Roberts, Marilyn C.
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /12/2003 Português
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Seventy-six Neisseria gonorrhoeae isolates, isolated between 1940 and 1987, and seven Neisseria meningitidis isolates, isolated between 1963 and 1987, were screened for the presence of acquired mef(A), erm(B), erm(C), and erm(F) genes by using DNA-DNA hybridization, PCR analysis, and sequencing. The mef(A), erm(B), and erm(F) genes were all identified in a 1955 N. gonorrhoeae isolate, while the erm(C) gene was identified in a 1963 N. gonorrhoeae isolate. Similarly, both the mef(A) and erm(F) genes were identified in a 1963 N. meningitidis isolate. All four acquired genes were found in later isolates of both species. The mef(A) gene from a 1975 N. gonorrhoeae isolate was sequenced and had 100% DNA and amino acid identity with the mef(A) gene from a 1990s Streptococcus pneumoniae isolate. Selected early isolates were able to transfer their acquired genes to an Enterococcus faecalis recipient, suggesting that these genes are associated with conjugative transposons. These isolates are the oldest of any species to carry the mef(A) gene and among the oldest to carry these erm genes.

Molecular Basis of Resistance to Macrolides and Other Antibiotics in Commensal Viridans Group Streptococci and Gemella spp. and Transfer of Resistance Genes to Streptococcus pneumoniae

Zolezzi, Paula Cerdá; Laplana, Leticia Millán; Calvo, Carmen Rubio; Cepero, Pilar Goñi; Erazo, Melisa Canales; Gómez-Lus, Rafael
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /09/2004 Português
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We assessed the mechanisms of resistance to macrolide-lincosamide-streptogramin B (MLSB) antibiotics and related antibiotics in erythromycin-resistant viridans group streptococci (n = 164) and Gemella spp. (n = 28). The macrolide resistance phenotype was predominant (59.38%); all isolates with this phenotype carried the mef(A) or mef(E) gene, with mef(E) being predominant (95.36%). The erm(B) gene was always detected in strains with constitutive and inducible MLSB resistance and was combined with the mef(A/E) gene in 47.44% of isolates. None of the isolates carried the erm(A) subclass erm(TR), erm(A), or erm(C) genes. The mel gene was detected in all but four strains carrying the mef(A/E) gene. The tet(M) gene was found in 86.90% of tetracycline-resistant isolates and was strongly associated with the presence of the erm(B) gene. The catpC194 gene was detected in seven chloramphenicol-resistant Streptococcus mitis isolates, and the aph(3′)-III gene was detected in four viridans group streptococcal isolates with high-level kanamycin resistance. The intTn gene was found in all isolates with the erm(B), tet(M), aph(3′)-III, and catpC194 gene. The mef(E) and mel genes were successfully transferred from both groups of bacteria to Streptococcus pneumoniae R6 by transformation. Viridans group streptococci and Gemella spp. seem to be important reservoirs of resistance genes.

Simultaneous Detection of Nine Antibiotic Resistance-Related Genes in Streptococcus agalactiae Using Multiplex PCR and Reverse Line Blot Hybridization Assay†

Zeng, Xianyu; Kong, Fanrong; Wang, Hui; Darbar, Archie; Gilbert, Gwendolyn L.
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /01/2006 Português
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Streptococcus agalactiae (group B streptococcus [GBS]) is the leading cause of neonatal and maternal sepsis. Penicillin is recommended for intrapartum prophylaxis, but erythromycin or clindamycin is used for penicillin-allergic carriers. Antibiotic resistance (AR) has increased recently and needs to be monitored. We have developed a multiplex PCR-based reverse line blot (mPCR/RLB) hybridization assay to detect, simultaneously, seven genes encoding AR—erm(A/TR), erm(B), mef(A/E), tet(M), tet(O), aphA-3, and aad-6—and two AR-related genes, int-Tn and mreA. We tested 512 GBS isolates from Asia and Australasia and compared mPCR/RLB with antibiotic susceptibility phenotype or single-gene PCR. Phenotypic resistance to tetracycline was identified in 450 (88%) isolates, of which 442 had tet(M) (93%) and/or tet(O) (6%). Of 67 (13%) erythromycin-resistant isolates, 18 were susceptible to clindamycin, i.e., had the M phenotype, encoded by mef(A/E); 39 had constitutive (cMLSB) and 10 inducible clindamycin resistance, and of these, 34 contained erm(B) and 12 erm(A/TR). Of four additional isolates with mef(A/E), three contained erm(B) with cMLSB and one was erythromycin susceptible. Of 61 (12%) clindamycin-resistant isolates, 20 were susceptible to erythromycin and two had intermediate resistance. Based on sequencing...

The promyelocytic leukemia protein functions as a negative regulator of IFN-γ signaling

Choi, Youn-Hee; Bernardi, Rosa; Pandolfi, Pier Paolo; Benveniste, Etty N.
Fonte: National Academy of Sciences Publicador: National Academy of Sciences
Tipo: Artigo de Revista Científica
Português
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IFN-γ is an immunomodulatory cytokine and uses the STAT-1α transcription factor to mediate gene expression. The promyelocytic leukemia (PML) protein regulates transcription as an activator or repressor, depending on the gene under investigation. Herein, we examined the influence of PML on IFN-γ signaling, using PML wild-type (Pml+/+) and deficient (Pml−/−) mouse embryonic fibroblasts (MEF). Pml−/− MEF exhibit enhanced IFN-γ-induced STAT-1α transcriptional activity compared with Pml+/+ cells. Moreover, reconstitution of PML in Pml−/− MEF reduced STAT-1α transcriptional activity to levels comparable to Pml+/+ MEF. Numerous endogenous IFN-γ-regulated genes were up-regulated in Pml−/− MEF compared with Pml+/+ MEF. IFN-γ-mediated STAT-1α DNA-binding activity was enhanced in Pml−/− cells compared with Pml+/+ cells. Lastly, IFN-γ enhanced the formation of a PML–STAT-1α complex in the nucleus. These data suggest a novel function for PML in the IFN-γ signaling pathway by inhibiting STAT-1α DNA binding and transcriptional activity.

Increasing the sensitivity of DNA microarrays by metal-enhanced fluorescence using surface-bound silver nanoparticles

Sabanayagam, Chandran R.; Lakowicz, Joseph R.
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica
Português
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The effects of metal-enhanced fluorescence (MEF) have been measured for two dyes commonly used in DNA microarrays, Cy3 and Cy5. Silver island films (SIFs) grown on glass microscope slides were used as substrates for MEF DNA arrays. We examined MEF by spotting biotinylated, singly-labeled 23 bp DNAs onto avidin-coated SIF substrates. The fluorescence enhancement was found to be dependent on the DNA spotting concentration: below ∼12.5 μM, MEF increased linearly, and at higher concentrations MEF remained at a constant maximum of 28-fold for Cy5 and 4-fold for Cy3, compared to avidin-coated glass substrates. Hybridization of singly-labeled oligonucleotides to arrayed single-stranded probes showed lower maximal MEF factors of 10-fold for Cy5 and 2.5-fold for Cy3, because of the smaller amount of immobilized fluorophores as a result of reduced surface hybridization efficiencies. We discuss how MEF can be used to increase the sensitivity of DNA arrays, especially for far red emitting fluorophores like Cy5, without significantly altering current microarray protocols.

Smooth Muscle α-Actin Expression and Myofibroblast Differentiation by TGFβ are Dependent Upon MK2

Sousa, Anne Marie; Liu, Tiegang; Guevara, Oscar; Stevens, JoAnne; Fanburg, Barry L.; Gaestel, Matthias; Toksoz, Deniz; Kayyali, Usamah S.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 15/04/2007 Português
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Fibroblasts play a major role in processes such as wound repair, scarring, and fibrosis. Differentiation into myofibroblasts, characterized by upregulation of smooth muscle α-actin (smα) in response to profibrotic agents such as TGFβ is believed to be an important step in fibrosis. Therefore, elucidating mechanisms of myofibroblast differentiation might reveal novel targets in treating diseases such as idiopathic pulmonary fibrosis (IPF). MK2 is a kinase substrate of p38 MAP kinase that mediates some effects of p38 activation on the actin cytoskeleton. Using mouse embryonic fibroblasts (MEF) from MK2 knockout (MK2−/−) mice, we demonstrate that disrupting expression of MK2 expression reduces filamentous actin and stress fibers. It also causes MK2−/− MEF to express less smα than their corresponding wild-type (WT) MEF at baseline and in response to TGFβ. Furthermore, TGFβ causes downregulation of smα in MK2−/− MEF, instead of upregulation observed in WT MEF. Expression of other fibroblast markers, such as collagen, is not altered in MK2−/− MEF. Our results further suggest that downregulation of smα in MK2−/− MEF is not due to lack of activation of serum responsive promoter elements, but probably due to reduced smα message stability in these cells. These results indicate that MK2 plays a key role in regulation of smα expression...

Manganese superoxide dismutase: Effect of the ala16val polymorphism on protein, activity, and mRNA levels in human breast cancer cell lines and stably transfected mouse embryonic fibroblasts

McAtee, Britt L.; Yager, James D.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Português
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The manganese superoxide dismutase (MnSOD) ala16val polymorphism has been associated with various diseases including breast cancer. In the present study, we investigated levels of MnSOD protein, enzymatic activity and mRNA with respect to MnSOD genotype in several human breast carcinoma cell lines and in mouse embryonic fibroblasts (MEF), developed from the MnSOD knockout mouse, stably expressing human MnSOD-ala and MnSOD-val. In human breast cell lines, the MnSOD-ala allele was associated with increased levels of MnSOD protein and MnSOD protein per unit mRNA. In the MEF transformants, MnSOD activity correlated fairly well with MnSOD protein levels. MnSOD mRNA expression was significantly lower in MnSOD-ala versus MnSOD-val lines. MnSOD protein and activity levels were not related to MnSOD genotype in the transformed MEF, although, as observed in the human breast cell lines, the MEF human MnSOD-ala lines produced significantly more human MnSOD protein per unit mRNA than the human MnSOD-val lines. This suggests that there is more efficient production of MnSOD-ala protein compared to MnSOD-val protein. Examination of several indicators of reactive oxygen species levels, including superoxide and hydrogen peroxide, in wild type MEF and in MEF expressing similar elevated amounts of MnSOD-ala or val activity did not show differences related to the levels of MnSOD protein expression. In conclusion...

Molecular Mechanisms of Fragile X Syndrome Investigated by Mass Spectrometry-Based Proteomics

Matic, Katarina
Fonte: Universität Tübingen Publicador: Universität Tübingen
Tipo: Dissertation; info:eu-repo/semantics/doctoralThesis
Português
Relevância na Pesquisa
17.404128%
Fragile X syndrome (FXS) is the leading cause of inherited intellectual disability (ID) and autism. This neurodevelopmental disorder is caused by silencing of the FMR1 gene and lack of its product, Fragile X Mental Retardation Protein (FMRP). FMRP, an RNA-binding protein, is highly expressed in the brain and plays an important role in the transport and translation of many different mRNA targets. Lack of FMRP causes disruption in synapse morphology and function, as well as disruption in synaptic plasticity. These molecular and synaptic abnormalities cause FXS symptoms like ID, autism, hyperactivity, epilepsy and anxiety. Therefore, understanding of the molecular pathogenesis of FXS is also important for other neurodevelopmental and psychiatric disorders. In last two decades, extensive research in basic neurobiology and pathophysiology led to significant advances in FXS field. However, although caused by only one gene, the molecular mechanisms of FXS are not yet well understood. Since FMRP is characterized as a translational regulator with multiple mRNA targets, it is crucial to understand the changes of the proteome in the absence of FMRP. As multiple FMRP-regulated proteins are involved in conserved neuronal signal transduction pathways...

Reconstruction des mouvements du plasma dans une région active solaire à l'aide de données d'observation et d'une minimisation Lagrangienne

Tremblay, Benoit
Fonte: Université de Montréal Publicador: Université de Montréal
Tipo: Thèse ou Mémoire numérique / Electronic Thesis or Dissertation
Português
Relevância na Pesquisa
17.360149%
À ce jour, les différentes méthodes de reconstruction des mouvements du plasma à la surface du Soleil qui ont été proposées présupposent une MHD idéale (Welsch et al., 2007). Cependant, Chae & Sakurai (2008) ont montré l’existence d’une diffusivité magnétique turbulente à la photosphère. Nous introduisons une généralisation de la méthode du Minimum Energy Fit (MEF ; Longcope, 2004) pour les plasmas résistifs. Le Resistive Minimum Energy Fit (MEF-R ; Tremblay & Vincent, 2014) reconstruit les champs de vitesse du plasma et la diffusivité magnétique turbulente qui satisfont à l’équation d’induction magnétique résistive et qui minimisent une fonctionnelle analogue à l’énergie cinétique totale. Une séquence de magnétogrammes et de Dopplergrammes sur les régions actives AR 9077 et AR 12158 ayant chacune produit une éruption de classe X a été utilisée dans MEF-R pour reconstruire les mouvements du plasma à la surface du Soleil. Les séquences temporelles des vitesses et des diffusivités magnétiques turbulentes calculées par MEF-R sont comparées au flux en rayons X mous enregistré par le satellite GOES-15 avant, pendant et après l’éruption. Pour AR 12158, nous observons une corrélation entre les valeurs significatives de la diffusivité magnétique turbulente et de la vitesse microturbulente pour les champs magnétiques faibles.; To this day...