191 research outputs found

    Geometrical distribution of Cryptococcus neoformans mediates flower-like biofilm development

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    Microbial biofilms are highly structured and dynamic communities in which phenotypic diversification allows microorganisms to adapt to different environments under distinct conditions. The environmentally ubiquitous pathogen Cryptococcus neoformans colonizes many niches of the human body and implanted medical devices in the form of biofilms, an important virulence factor. A new approach was used to characterize the underlying geometrical distribution of C. neoformans cells during the adhesion stage of biofilm formation. Geometrical aspects of adhered cells were calculated from the Delaunay triangulation and Voronoi diagramobtained fromscanning electronmicroscopy images (SEM). A correlation between increased biofilm formation and higher ordering of the underlying cell distribution was found. Mature biofilm aggregates were analyzed by applying an adapted protocol developed for ultrastructure visualization of cryptococcal cells by SEM. Flower-like clusters consisting of cells embedded in a dense layer of extracellular matrix were observed as well as distinct levels of spatial organization: adhered cells, clusters of cells and community of clusters. The results add insights into yeast motility during the dispersion stage of biofilm formation. This study highlights the importance of cellular organization for biofilm growth and presents a novel application of the geometrical method of analysis

    Pathogenic Rickettsia in ticks of spur-thighed tortoise (Testudo graeca) sold in a Qatar live animal market

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    Research Areas: Infectious Diseases ; Veterinary SciencesThe dissemination of vector arthropods harbouring zoonotic pathogens through the uncontrolled transboundary trade of exotic and pet animals poses an important threat to Public Health. In the present report, we describe the introduction of pathogenic Rickettsia africae and R. aeschlimanni in ticks removed from imported tortoises in Qatar. A total of 21 ticks were collected from pet spur‐thighed tortoises (Testudo graeca) from Doha, May 2018, and studied for species identification and characterization of Rickettsia spp. Morphological and molecular analysis of ticks allowed their identification as Hyalomma aegyptium. Molecular analysis of partial ompA and gltA genes showed that Rickettsia sequences found on these ticks clustered with sequences classified as R. aeschilimanii and R. africae. Since pre‐adult stages of H. aegyptium also feed on humans, this tick species may play a role in the transmission of R. aeschilimanii and R. africae. We alert for the introduction of non‐native pets as vehicles for tick importation, known vectors for animal and human pathogenic agents. Importation of exotic species into non‐autochthonous countries deserves strict control to enforce robust surveillance and mitigate potential exotic diseases epidemics.info:eu-repo/semantics/publishedVersio

    Instrumentação virtual para avaliação automática de gordura corporal com tecnologia wireless

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    Um método universalmente utilizado para avaliação subcutânea de gordura corporal baseia-se em medições antropométricas obtidas através de um instrumento portátil e de baixo custo designado por Lipocalibrador. Este método não invasivo, considerado duplamente indirecto, permite a determinação quantitativa da composição corporal em tecido gordo e não gordo pela medição da espessura de pregas cutâneas1. Este método éreconhecido na literatura como a forma mais simples de avaliar estes dois compartimentos e fornece resultados fiáveis se correctamente aplicado. Mas, para queos resultados sejam consistentes, tem que ser realizado por técnicos altamente especializados, seguindo um procedimento estipulado e procurando minimizaravaliações e decisões subjectivas2.O trabalho que se apresenta procura reduzir as subjectividades inerentes a este método de medição, facilitando a sua utilização na prática clínica e na avaliação de grandes amostras populacionais

    Peripheral axonal ensheathment is regulated by RalA GTPase and the exocyst complex

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    Funding This work was supported by H2020 Marie Skłodowska-Curie Actions [H2020- GA661543-Neuronal Trafficking to R.O.T.], Fundo Regional para a Ciência e Tecnologia [IF/00392/2013/CP1192/CT0002 to R.O.T.] and iNOVA4Health (UID/Multi/04462/2013) (co-funded by FCT-FEDER-PT2020).Axon ensheathment is fundamental for fast impulse conduction and the normal physiological functioning of the nervous system. Defects in axonal insulation lead to debilitating conditions, but, despite its importance, the molecular players responsible are poorly defined. Here, we identify RalA GTPase as a key player in axon ensheathment in Drosophila larval peripheral nerves. We demonstrate through genetic analysis that RalA action through the exocyst complex is required in wrapping glial cells to regulate their growth and development. We suggest that the RalA-exocyst pathway controls the targeting of secretory vesicles for membrane growth or for the secretion of a wrapping glia-derived factor that itself regulates growth. In summary, our findings provide a new molecular understanding of the process by which axons are ensheathed in vivo, a process that is crucial for normal neuronal function.publishersversionpublishe

    Intestinal anti-inflammatory effects of goat whey on DNBS-induced colitis in mice

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    This study evaluated the intestinal anti-inflammatory effects of goat whey in a mouse model of colitis induced by 2,4-dinitrobenzenesulfonic acid that resembles human IBD. At a concentration of 4 g/kg/day, the goat whey improved the symptoms of intestinal inflammation, namely by decreasing the disease activity index, colonic weight/length, and leukocyte infiltration. Moreover, goat whey inhibited NF-kappa B p65 and p38 MAPK signaling pathways and consequently down-regulated the gene expression of various proinflammatory markers such as IL-1 beta, IL-6, IL-17, TNF-alpha, iNOS, MMP-9, ICAM-1. Also, goat whey increased the expression of proteins such as mucins, occludin proteins and cytokine signalling suppressors. The immunomodulatory properties of goat whey were also evaluated in vitro using the murine macrophage cell line Raw 264 and CMT-93 cells derived from mouse rectum carcinomas. The results revealed the ability of goat whey to inhibit the production of NO and reduce IL-6 production in LPS-stimulated cells. In conclusion, goat whey exhibited antiinflammatory effects in the DNBS model of intestinal inflammation, and these observations were confirmed by its immunomodulatory properties in vitro. Together, our results indicate that goat whey could have applications for the treatment of IBD.info:eu-repo/semantics/publishedVersio

    REASE – Rede regional de sensibilização dos serviços prestados pelos ecossistemas das pradarias de ervas marinhas e sapais na região do Algarve.

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    Projeto financiado pelo Fundo Ambiental da República PortuguesaA Rede de Educação Ambiental para os Serviços Ambientais (REASE) é uma iniciativa recentemente criada no Algarve, por instituições de pesquisa científica, educação, divulgação científica e uma ONG ambiental. O REASE tem como objetivo desenvolver projetos de educação ambiental na área dos Serviços Ecossistémicos (SE), especialmente aqueles gerados pela vegetação costeira, incluindo sapais e pradarias marítimas. Atualmente, a rede está trabalhando em: 1) capacitação de professores e gestores ambientais, a fim de promover o conhecimento científico sobre os serviços prestados pelos ecossistemas costeiros; 2) a criação de uma “incubadora de projetos” para poder desenvolver em escolas locais projetos SE inovadores de educação formal; 3) sensibilização dos estudantes e do público em geral sobre o papel dos ecossistemas para o bem-estar humano através de exposições e palestras em centros de divulgação científica; 4) publicação de um livro para crianças sobre SE de ervas marinhas, num processo participativo de base comunitária (ilustrações feitas por crianças nas escolas); 5) o lançamento de um projeto de Ciência Cidadã, para avaliar a produção de Carbono Azul no Algarve, envolvendo escolas que recebem kits de campo e de laboratório e respetivo apoio científico; 6) o desenvolvimento de uma aplicação móvel para fazer upload diretamente das medições de campo e dados do carbono azul no site do projeto, onde os dados são cientificamente validados e analisados.SFRH/BGCT/52704/2014 - REFORÇO DA INTERAÇÃO COM ENTIDADES EXTERNAS E RENOVAÇÃO DE ACTIVIDADES E DE CONTEÚDOS (SFRH/BGCT/52704/2014)info:eu-repo/semantics/publishedVersio

    SARS-CoV-2 introductions and early dynamics of the epidemic in Portugal

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    Genomic surveillance of SARS-CoV-2 in Portugal was rapidly implemented by the National Institute of Health in the early stages of the COVID-19 epidemic, in collaboration with more than 50 laboratories distributed nationwide. Methods By applying recent phylodynamic models that allow integration of individual-based travel history, we reconstructed and characterized the spatio-temporal dynamics of SARSCoV-2 introductions and early dissemination in Portugal. Results We detected at least 277 independent SARS-CoV-2 introductions, mostly from European countries (namely the United Kingdom, Spain, France, Italy, and Switzerland), which were consistent with the countries with the highest connectivity with Portugal. Although most introductions were estimated to have occurred during early March 2020, it is likely that SARS-CoV-2 was silently circulating in Portugal throughout February, before the first cases were confirmed. Conclusions Here we conclude that the earlier implementation of measures could have minimized the number of introductions and subsequent virus expansion in Portugal. This study lays the foundation for genomic epidemiology of SARS-CoV-2 in Portugal, and highlights the need for systematic and geographically-representative genomic surveillance.We gratefully acknowledge to Sara Hill and Nuno Faria (University of Oxford) and Joshua Quick and Nick Loman (University of Birmingham) for kindly providing us with the initial sets of Artic Network primers for NGS; Rafael Mamede (MRamirez team, IMM, Lisbon) for developing and sharing a bioinformatics script for sequence curation (https://github.com/rfm-targa/BioinfUtils); Philippe Lemey (KU Leuven) for providing guidance on the implementation of the phylodynamic models; Joshua L. Cherry (National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health) for providing guidance with the subsampling strategies; and all authors, originating and submitting laboratories who have contributed genome data on GISAID (https://www.gisaid.org/) on which part of this research is based. The opinions expressed in this article are those of the authors and do not reflect the view of the National Institutes of Health, the Department of Health and Human Services, or the United States government. This study is co-funded by Fundação para a Ciência e Tecnologia and Agência de Investigação Clínica e Inovação Biomédica (234_596874175) on behalf of the Research 4 COVID-19 call. Some infrastructural resources used in this study come from the GenomePT project (POCI-01-0145-FEDER-022184), supported by COMPETE 2020 - Operational Programme for Competitiveness and Internationalisation (POCI), Lisboa Portugal Regional Operational Programme (Lisboa2020), Algarve Portugal Regional Operational Programme (CRESC Algarve2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF), and by Fundação para a Ciência e a Tecnologia (FCT).info:eu-repo/semantics/publishedVersio
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