Extracellular matrix and integrins influence in the regulation of myogenic precursor cells behaviour

Tese de mestrado, Biologia (Biologia Molecular Humana), 2009, Universidade de Lisboa, Faculdade de CiênciasMyogenesis is the process by which undifferentiated dermomyotomal cells are specified for myogenesis, move towards the myotome where they differentiate into skeletal muscle cells that fuse into myotubes and later in development form myofibers which will constitute the skeletal muscles of the adult. The muscle precursor cells arise from the dermomyotome, an epithelial-like structure that is the source for skeletal muscle and dorsal dermis cells. Some cells, called satellite cells, go throughout part of this differentiation process but remain in a quiescent undifferentiated state (although committed to skeletal muscle fate). These cells are activated in the adult in case of muscle injury or enhanced exercise, for example. In this work we used a satellite cell-derived cell line, C2C12, and the mouse embryo to study the extracellular matrix (ECM) and integrins influence in myogenic determination and differentiation. Integrins are heterodimeric ECM receptors constituted by an α and a ß subunit that can induce, for example, migration or differentiation. The integrin ligand specificity is acquired by the combination of both subunits. Our studies have addressed that laminin-α6ß1 integrin interaction may be coordinating with Notch signaling the maintenance of undifferentiated dermomyotomal cells. By inhibiting Notch signaling, we observed precocious myogenic differentiation of dermomyotomal cells (by Myf5 expression) and the assembly of a laminin matrix around these cells. This result suggests that Myf5 induces laminin assembly. In vitro, fibronectin enhances C2C12 myoblasts alignment and migration. When we observed the myotubes of cells grown on fibronectin, we believe that the enhanced cell alignment imposed by fibronectin-α5ß1 integrin interaction will facilitate cell fusion. In vivo, we found that fibronectin is important for dermomyotome epithelial-integrity, especially through the polarization of N-cadherin, and that α5ß1 integrin signaling may also contribute to myogenic repression in the dermomyotome. These observations show that the ECM and integrins are of paramount importance in myoblast cell behaviour.Resumo alargado em português disponível no document

Determinantes da estrutura de capitais : o caso do sector do calçado

O tema estrutura de capitais tem desenvolvido diversas teorias e tem sido alvo de investigação desde os primeiros estudos de Modigliani e Miller (1958). A presente dissertação tem como objectivo analisar os determinantes da estrutura de capitais, com base em diversas investigações desenvolvidas sobre o tema da estrutura de capitais. Pretende-se verificar quais os factores influenciadores do nível de endividamento de empresas do sector do calçado Português, tentado enquadrar nas teorias relacionadas com a tomada de decisão sobre a forma de financiamentos das empresas. A análise efectuada, através do modelo de regressão linear, com dados entre o ano de 2006 e 2012, indica a existência de uma relação positiva entre o endividamento e as variáveis independentes dimensão e composição do activo. As restantes variáveis independentes demonstraram não influenciar o nível de endividamento das empresas do sector do calçado. Com a elaboração deste trabalho foi perceptível que as teorias não são facilmente observáveis na realidade do nosso país inclusive que, para a variável outros benefícios fiscais para além da dívida, não tem qualquer impacto no endividamento da amostra, ao contrário do que era expectável indo também contra a teoria de trade-off.The capital structure has developed several theories and has been the subject of research since the early studies of Modigliani and Miller (1958). This thesis aims to analyze the determinants of capital structure based on various investigations developed on the subject of capital structure. It is intended to verify the factors influencing the level of indebtedness of Portuguese companies in the footwear sector, tried to frame the theories related to the choice of business financing. The analysis, using linear regression model, using data between 2006 and 2012, indicates the existence of a positive relationship between debt and the independent variables size and composition of the asset. The remaining independent variables were not influencing the level of indebtedness of the companies in the footwear industry. With the development of this work was noticeable that the theories are not readily observable in the reality of our country including that for the variable other tax benefits beyond the debt has no impact on debt sample, contrary to what was expected, going also against the theory of trade-off

Microaerophilic growth characteristics of Pseudomonas aeruginosa importance to the successful treatment of chronic infections in cystic fibrosis lungs

Patients with CF lung disease are susceptible to chronic infections by various pathogens, such as Pseudomonas aeruginosa. This pathogen is able to adaptat to the environment in CF lungs, characterized by inflammatory defences, oxygen restriction, and poor nutrient availability. It is well established that, once P. aeruginosa infection is installed in the lungs, it is almost impossible to eradicate, due to sophisticated genotypic and phenotypic adaptation mechanisms that develop according to the stage of infection. Understanding those changes and the identification of specific characteristics that allow P. aeruginosa eradication before the onset of chronic infection is urgent. In this work, P. aeruginosa adaptation under microaerophilic and anaerobic conditions was assessed in terms of phenotypic charatceristics, antibiotic susceptibility and expression of antibiotic resistance mechanisms (mexAB operon). Results showed, when compared with aerobic conditions, similar growth and emergence of intermediate resistance profiles for ciprofloxacin and imipenem, but no significant variation in operon mexAB expression. It was also observed an increase of colony morphotypes with the decrease of oxygen availability, mainly in 5% O2. Nevertheless oxygen depletion has no significant effect on P. aeruginosa growth and mexAB expression, affecting, however, the phenotypic characteristics and antibiotic susceptibility profiles. Despite the overall observations, the microaerophilic environment with 5% O2, seems to demonstrate a transient distinct behaviourwhich can be a point of evolution into chronic infection and as such a possible treatment target

Indirect Effects of Oral Tolerance Inhibit Pulmonary Granulomas to Schistosoma mansoni Eggs

Parenteral injection of tolerated proteins into orally tolerant mice inhibits the initiation of immunological responses to unrelated proteins and blocks severe chronic inflammatory reactions of immunological origin, such as autoimmune reactions. This inhibitory effect which we have called “indirect effects of oral tolerance” is also known as “bystander suppression.” Herein, we show that i.p. injection of OVA + Al(OH)3 minutes before i.v. injection of Schistosoma mansoni eggs into OVA tolerant mice blocked the increase of pulmonary granulomas. In addition, the expression of ICAM-1 in lung parenchyma in areas outside the granulomas of OVA-orally tolerant mice was significantly reduced. However, at day 18 after granuloma induction there was no difference in immunofluorescency intensity to CD3, CD4, F4/80, andα-SMA per granuloma area of tolerant and control groups. Reduction of granulomas by reexposure to orally tolerated proteins was not correlated with a shift in Th-1/Th-2 cytokines in serum or lung tissue extract

Polpa cítrica úmida na terminação de cordeiros confinados:: desempenho e concentração de enzimas hepáticas

A indústria de produção de pectina gera um resíduo composto por pedúnculo, endocarpo, vesículas de suco, columela, sementes e minúsculas frações de epicarpo e mesocarpo de frutas cítricas, denominada Polpa Cítrica Úmida (WCP), que ainda não foi testada como alimento na nutrição de ovinos. Sendo assim, este estudo teve como objetivo avaliar o efeito da substituição parcial do milho pela WCP em dietas contendo elevado teor de concentrado sobre o desempenho e a concentração de enzimas hepáticas de cordeiros confinados. Quarenta e dois cordeiros machos (15 Santa Inês e 27 ½ Dorper x Santa Inês), com 24,7 ± 1,5 kg de peso corporal e 60 ± 5 dias de idade foram distribuídos em delineamento de blocos completos casualizados. Dentro de cada bloco (n = 14), os cordeiros foram distribuídos aleatoriamente entreos tratamentos: 0WCP – dieta contendo 75,5% de milho moído, sem a inclusão de WCP; 20WCP – dieta contendo 20% de WCP em substituição ao milho moído; e 40WCP – dieta contendo 40% de WCP em substituição ao milho moído. O experimento teve duração de 70 dias, sendo dividido em 3 períodos experimentais (14 dias de adaptação as dietas e 2 períodos de 28 dias cada). As análises estatísticas foram realizadas utilizando o procedimento MIXED do SAS. Os polinômios ortogonais lineares e quadráticos foram utilizados para avaliar o efeito das dietas. Houve efeito quadrático para o consumo de matéria seca, PB, cinzas, extrato etéreo e CNF. A maior ingestão de MS e PB foi observada para os cordeiros alimentados com 20WCP, entretanto, a dieta controle aumentou o consumo de cinzas, extrato etéreo e CNF. O aumento na inclusão de WCP diminuiu o ganho médio diário e a eficiência alimentar durante o período de adaptação,entretanto, não afetou essas variáveis durante os períodos 1 e 2. Consequentemente, a inclusão de WCP reduziu o peso corporal ao final do período experimental. Não houve efeito das dietas na concentração de gama-glutamil transferase (GGT). Entretanto, houve aumento linear na concentração de aspartato aminotransferase (AST) durante o período de adaptação. Em conclusão, a inclusão de até 40% de WCP nas dietas de terminação para cordeiros confinados diminuiu o desempenho durante o período de adaptação, comprometendo o peso corporal ao final do período experimental, entretanto, não comprometeu a afetou as enzimas hepáticas. Pectin industry generates a citrus pulp residue compounded by peduncle, endocarp, juice vesicles, columella, seeds and tiny fractions of epicarp and mesocarp of citrus fruits, denominated Wet Citrus Pulp (WCP), which has not yet been tested as food for lamb’s nutrition. Thus, this study aimed to determine the effect of partial replacement of ground corn by WCP in high-concentrate diets on the performance and hepatic enzyme concentration of feedlot lambs. Forty-two male lambs (15 Santa Inês and 27 ½ Dorper × Santa Inês), with 24.7 ± 1.5 kg of BW and 60 ± 5 d of age was assigned to a randomized complete block design. Within blocks (n = 14), lambs were randomly assigned to 1 of 3 treatments: 0WCP (control) – diet containing 75.5% ground corn without WCP; 20WCP – diet containing 20% WCP in replacement of ground corn, and 40WCP – diet containing 40% WCP in replacement of ground corn. The experiment lasted 70 days, which was split in 3 experimental periods (14 days of diets’ adaptation and 2 sub-periods of 28 days each). Statistical analyses were performed using the MIXED procedure of the SAS. Orthogonal polynomials for diet response were determined by linear and quadratic effects. There was a quadratic effect for DM, CP, ash, ether extract and NFC intake The highest DM and CP intake was observed for lambs fed 20WCP, however, the control diet increased the ash, ether extract and NFC intake. The increased levels of WCP decreased the ADG and feed efficiency (FE) during the adaptation period, however, did not affect the ADG and FE on periods 1 and 2. Consequently, the increased levels of WCP inclusion decreased linearly the BW. There was no effect of WCP inclusion in diets on Gamma-Glutamyl Transferase (GGT) concentration. However, there was a linear increase for Aspartate Aminotransferase (AST) concentration during the adaptation period, but without difference in other periods. In conclusion, adding up to 40% of WCP in finishing diets for feedlot lambs decrease performance during adaptation period, compromising the final body weight, but without damages effects on liver enzymes

Environmental azole fungicide, prochloraz, can induce cross-resistance to medical triazoles in Candida glabrata

Acquisition of azole resistance by clinically relevant yeasts in nature may result in a significant, yet undetermined, impact in human health. The main goal of this study was to assess the development of cross-resistance between agricultural and clinical azoles by Candida spp. An in vitro induction assay was performed, for a period of 90 days, with prochloraz (PCZ) - an agricultural antifungal. Afterward, the induced molecular resistance mechanisms were unveiled. MIC value of PCZ increased significantly in all Candida spp. isolates. However, only C. glabrata developed cross-resistance to fluconazole and posaconazole. The increased MIC values were stable. Candida glabrata azole resistance acquisition triggered by PCZ exposure involved the upregulation of the ATP binding cassette multidrug transporter genes and the transcription factor, PDR1. Single mutation previously implicated in azole resistance was found in PDR1 while ERG11 showed several synonymous single nucleotide polymorphisms. These results might explain why C. glabrata is so commonly less susceptible to clinical azoles, suggesting that its exposure to agricultural azole antifungals may be associated to the emergence of cross-resistance. Such studies forward potential explanations for the worldwide increasing clinical prevalence of C. glabrata and the associated worse prognosis of an infection by this species.info:eu-repo/semantics/publishedVersio

Promoção do sono seguro no recém-nascido pré-termo em unidades de neonatologia

Introdução e Objetivos: As Unidades de Cuidados Intensivos Neonatais (UCIN) são fundamentais à sobrevivência do recém-nascido pré-termo, embora proporcionem um espaço diferente do útero materno. Como linha orientadora das práticas foi desenvolvido o Modelo de Cuidados Centrados no Desenvolvimento, que inclui sete medidas neuroprotetoras, entre as quais a “promoção do sono seguro”, foco do presente trabalho. Neste sentido, o objetivo desta Revisão Narrativa da Literatura foi descortinar a evidência científica de suporte às práticas de cuidados em neonatologia na promoção do sono seguro e refletir sobre estas práticas em duas unidades de neonatologia. Metodologia: Revisão narrativa da literatura com recurso à MEDLINE, CINAHL, literatura cinzenta, com os Descritores: NICU, preterm infant, neurodevelopment, sleep, neonatology, nursing. Resultados: Os achados da evidência científica (28 artigos sobre o sono) permitiram uma reflexão sobre as práticas de cuidados para a promoção do sono seguro que envolveu a discussão entre estudantes e profissionais de saúde e a elaboração e realização de sessões de educação para a saúde. A evidência mostra a importância de se desenvolverem Programas de Educação para o Sono Seguro com intervenção no Hospital e em Casa, capacitando os pais para os cuidados durante o internamento, visando a preparação para a alta. Conclusão: A reflexão sobre as práticas permitiu-nos concluir que nas duas unidades se promove o conforto do recém-nascido pré-termo e a vinculação com os pais, visando o sono seguro. Muito trabalho tem sido desenvolvido nas unidades de neonatologia neste sentido, mas ainda há um longo caminho a percorrer, o qual exige mais investigação nesta área importante para o neurodesenvolvimento.abstract:Introduction and Objectives: Neonatal Intensive Care Units (NICU) are fundamental to the survival of the preterm infant, eventhough, they provide a different space from the maternal uterus. A guideline of care practices in this units the “Neonatal Model of Care Centered in Development” were developed and established, which includes seven neuroprotective measures, being the “safe sleep promotion” measure this article focus. Therefore, the objective of the worked Narrative Review of Literature was to uncover the scientific evidence to support the care practices in neonatal intensive care units, on promoting safe sleep, as well as, a situational reflection about pratices in two neonatal intensive care units. Metodology: Narrative review of literature with 58 |pensa refpamsgpm|Vol. 23 | N.º 2 | 2º Semestre de 2019resource to MEDLINE, CINAHL and grey literature. Descriptors: NICU, preterm infant, neurodevelopment, sleep, neonatology, nursing. Results: The findings of the scientific evidence (28 articles about sleep) allowed a reflection of the care practices for the promotion of safe sleep, which involved the discussion between students and health care professionals and the elaboration and promotion of health education meetings. The evidence showed the importance of the Educational Programs development, on Sleep Promotion, with intervention in Hospital and at Home areas, empowering the parents to provide care during the hospitalization, in order to prepare them for discharge. Conclusion: The reflection on care practices allowed us to conclude that in both units preterm infant confort and bond with their parents are granted, aiming safe sleep. A lot of work has been developed in those units to promote safe sleep, but there is still a long way to go, which demands investigation in an area as important as neurodevelopment.info:eu-repo/semantics/publishedVersio

How do companies communicate sustainability? a systematic literature review

Sustainability is a topic that is increasingly discussed in society and organizations, leading many companies to adopt communication strategies focused on this theme. The objective of this article was to identify in the literature the ways, means, or tools that companies use to communicate sustainability. This article was based on a systematic review of the literature on the topic, resulting in a final sample of 18 articles from 14 different journals. Seven potential topics were identified in the systematic review: (i) communication strategies, (ii) the relationship between communication and consumer behavior, (iii) communication and health benefits, (iv) sustainability and corporate social responsibility (CSR), (v) sustainable business models, (vi) sustainability and process optimization, and (vii) sustainability and environmental impact. The results obtained allowed us to conclude that the strategies that companies can use to communicate sustainability are as follows: use new technologies (internet, social networks, websites, etc.), make value propositions based on consumer behaviors, disseminate clear and consistent information, and ensure broader work teams, among others. These results contribute to the advancement of scientific literature and to the definition and implementation of more efficient and effective public policies that facilitate communication between companies and consumers. Finally, this paper offers practical suggestions to formulate sustainable communication strategies.F017-F614-4A6B | Susana Isabel Almeida CamposN/

House dust fungal communities’ characterization: a double take on the six by sixty by six project (6x60x6)

Fungi are a group microbes, that are found with particular incidence in the indoor environment. Their direct toxicity or capability of generating toxic compounds has been associated with a large number of adverse health effects, such as infectious diseases, allergies and other toxic effects. Given that in modern society people spend a large part of their time indoors; fungal communities’ characterization of this environmental compartment assumes paramount importance in the comprehension of health effects. House dust is an easy to obtain, time-integrative matrix, being its use in epidemiological studies on human exposure to environmental contaminants highly recommended. Furthermore, dust can carry a great variety of fungal content that undergoes a large number of processes that modulate and further complexify human exposure. Our study aims to quantify and identify the fungal community on house dust samples collected using two different methodologies (an approach not often seen in the literature): active (vacuum cleaner bags) and passive sampling (dust settled in petri dishes). Sampling was performed as part of the ongoing 6x60x6 Project in which six houses from Covilhã (Portugal), with building dates representative of six decades, were studied for a period of sixty days.info:eu-repo/semantics/publishedVersio

A globalização pós-Covid-19 e o medo dos outros. O que se segue?

O IDN Brief especial pandemia chega agora ao fim com um número dedicado ao impacto da COVID-19 na ordem mundial e nos equilíbrios geoestratégicos. Foram 9 edições, em que 90 especialistas partilharam as suas análises sobre os efeitos desta pandemia em múltiplas dimensões: da segurança sanitária à ação das forças armadas, da gestão de crises à segurança humana, da defesa Europeia à relação transatlântica, da cibersegurança aos equilíbrios de poder mundiais. Esta edição fecha com registos de diagnóstico e prospetiva sobre as dinâmicas da tensão e competição entre Estados Unidos e a China, o lugar da Europa e dos seus principais protagonistas, o espaço para o multilateralismo e o papel da ciência, a contradição entre o reforço dos interesses nacionais e as exigências de cooperação, a emergência, estabilidade ou irrelevância estratégica de diferentes espaços regionais, a produção do inimigo, a desconfiança e o medo dos outros. Continuaremos, com outros formatos e iniciativas, a acompanhar os cenários desta crise em desenvolvimento e de uma magnitude sem precedentes, na qual a expressão ‘saudades do futuro’ adquire um sentido muito particular, alimentando tanto visões pessimistas como demandas de ação e transformação.info:eu-repo/semantics/publishedVersio