753 research outputs found

    RELICT FORSTERITE IN UNEQUILIBRATED ENSTATITE CHONDRITES

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    82nd Annual Meeting of The Meteoritical Society 2019 (LPI Contrib. No. 2157). This is freely available from the LPI website. No copyright statement available

    H-Ferritin Is Essential for Macrophages' Capacity to Store or Detoxify Exogenously Added Iron

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    Macrophages are central cells both in the immune response and in iron homeostasis. Iron is both essential and potentially toxic. Therefore, iron acquisition, transport, storage, and release are tightly regulated, by several important proteins. Cytosolic ferritin is an iron storage protein composed of 24 subunits of either the L- or the H-type chains. H-ferritin differs from L-ferritin in the capacity to oxidize Fe2+ to Fe3+. In this work, we investigated the role played by H-ferritin in the macrophages' ability to respond to immune stimuli and to deal with exogenously added iron. We used mice with a conditional deletion of the H-ferritin gene in the myeloid lineage to obtain bone marrow-derived macrophages. These macrophages had normal viability and gene expression under basal culture conditions. However, when treated with interferon-gamma and lipopolysaccharide they had a lower activation of Nitric Oxide Synthase 2. Furthermore, H-ferritin-deficient macrophages had a higher sensitivity to iron-induced toxicity. This sensitivity was associated with a lower intracellular iron accumulation but a higher production of reactive oxygen species. These data indicate that H-ferritin modulates macrophage response to immune stimuli and that it plays an essential role in protection against iron-induced oxidative stress and cell death.Tis work was fnanced by FEDER - Fundo Europeu de Desenvolvimento Regional funds through the COMPETE2020 - Operacional Programme for Competitiveness and Internationalization (POCI), Portugal 2020, and by Portuguese funds through FCT - Fundação para a Ciência e a Tecnologia/Ministério da Ciência, Tecnologia e Ensino Superior in the framework of the project PTDC/IMI-MIC/1683/2014 (POCI-01-0145-FEDER-016590). PFO and MGA acknowledge FCT for the Investigador FCT 2015. We thank the valuable collaboration of the following i3S Scientifc Platforms: Cell Culture and Genotyping Core Facility (CCGen), [Histology and Electron Microscopy Service (HEMS), and BioSciences Screening], member of the PPBI (PPBI-POCI-01-0145-FEDER-022122)], Animal Facility, and Flow Cytometry Unit (TraCy). We acknowledge Lukas Kuhn (Swiss Institute for Experimental Cancer Research, Lausanne, Switzerland) for kindly providing the frst breeding pairs of Fth1−/− mice. Te authors also acknowledge Marisa Castro, from Departamento de Biologia Molecular from ICBAS, Clara Bento, from i3S, and Edgar Pinto from LAQV – REQUIMTE for technical assistance at diferent stages of the project

    Body adiposity index to analyze the percentage of fat in young men aged between 7 and 17 years

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    BACKGROUND: The body adiposity index (BAI), uses anthropometry to estimate percent body fat (%F). However, previous studies have shown that the BAI has limited accuracy for children and adolescents. OBJECTIVE: We propose to develop and validate an adjusted BAI for use in male children and adolescents from 7 to 17 years of age. METHODS: The sample consisted of 141 physically active male children and adolescents (age: 12.5 ± 2.14). The %F was determined by X-ray dual energy absorptometry equipment (DXA) as the standard method and by BAI, using an equation that uses height and hip circumference. Arithmetic modeling was used to adjust the structure of the BAI mathematical model. RESULTS: The BAI arithmetic adjustment was successful, resulting in the mathematical model named in the present study of adjusted body adiposity index (BAIADJ ). BAI and BAIADJ correlated with DXA (r ≤ .70, p  .05). CONCLUSION: The adjusted model of the body adiposity index proves to be an effective tool for the analysis of the fat percentage in young males. In addition, it demonstrated significant degrees of agreement and validity in relation to DXA

    Primary Health Care: care coordinator in regionalized networks?

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    RESUMO OBJECTIVE To analyze the breadth of care coordination by Primary Health Care in three health regions. METHODS This is a quantitative and qualitative case study. Thirty-one semi-structured interviews with municipal, regional and state managers were carried out, besides a cross-sectional survey with the administration of questionnaires to physicians (74), nurses (127), and a representative sample of users (1,590) of Estratégia Saúde da Família (Family Health Strategy) in three municipal centers of health regions in the state of Bahia. RESULTS Primary Health Care as first contact of preference faced strong competition from hospital outpatient and emergency services outside the network. Issues related to access to and provision of specialized care were aggravated by dependence on the private sector in the regions, despite progress observed in institutionalizing flows starting out from Primary Health Care. The counter-referral system was deficient and interprofessional communication was scarce, especially concerning services provided by the contracted network. CONCLUSIONS Coordination capacity is affected both by the fragmentation of the regional network and intrinsic problems in Primary Health Care, which poorly supported in its essential attributes. Although the health regions have common problems, Primary Health Care remains a subject confined to municipal boundaries

    B cells Can Modulate the CD8 Memory T Cell after DNA Vaccination Against Experimental Tuberculosis

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    Abstract\ud \ud \ud \ud Background\ud \ud Although B cells are important as antigen presenting cells (APC) during the immune response, their role in DNA vaccination models is unknown.\ud \ud \ud \ud Methods\ud \ud In this study in vitro and in vivo experiments were performed to evaluate the ability of B cells to protect mice against Mycobacterium tuberculosis challenge.\ud \ud \ud \ud Results\ud \ud \ud In vitro and in vivo studies showed that B cells efficiently present antigens after naked plasmid pcDNA3 encoding M. leprae 65-kDa heat shock protein (pcDNA3-Hsp65) internalization and protect B knock-out (BKO) mice against Mycobacterium tuberculosis infection. pcDNA3-Hsp65-transfected B cells adoptively transferred into BKO mice rescued the memory phenotypes and reduced the number of CFU compared to wild-type mice.\ud \ud \ud \ud Conclusions\ud \ud These data not only suggest that B cells play an important role in the induction of CD8 T cells but also that they improve bacterial clearance in DNA vaccine model.We are thankful to Ana Paula Masson and Izaíra T Brandão for providing the DNA vaccine and recombinant protein. This study was supported by a FAPESP fellowship (05/030873) to LPA.We are thankful to Ana Paula Masson and Izaíra T Brandão for providing the DNA vaccine and recombinant protein. This study was supported by a FAPESP fellowship (05/03087-3) to LPA

    Phase transitions in biological membranes

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    Native membranes of biological cells display melting transitions of their lipids at a temperature of 10-20 degrees below body temperature. Such transitions can be observed in various bacterial cells, in nerves, in cancer cells, but also in lung surfactant. It seems as if the presence of transitions slightly below physiological temperature is a generic property of most cells. They are important because they influence many physical properties of the membranes. At the transition temperature, membranes display a larger permeability that is accompanied by ion-channel-like phenomena even in the complete absence of proteins. Membranes are softer, which implies that phenomena such as endocytosis and exocytosis are facilitated. Mechanical signal propagation phenomena related to nerve pulses are strongly enhanced. The position of transitions can be affected by changes in temperature, pressure, pH and salt concentration or by the presence of anesthetics. Thus, even at physiological temperature, these transitions are of relevance. There position and thereby the physical properties of the membrane can be controlled by changes in the intensive thermodynamic variables. Here, we review some of the experimental findings and the thermodynamics that describes the control of the membrane function.Comment: 23 pages, 15 figure

    Spontaneous charged lipid transfer between lipid vesicles

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    An assay to study the spontaneous charged lipid transfer between lipid vesicles is described. A donor/acceptor vesicle system is employed, where neutrally charged acceptor vesicles are fluorescently labelled with the electrostatic membrane probe Fluoresceinphosphatidylethanolamine (FPE). Upon addition of charged donor vesicles, transfer of negatively charged lipid occurs, resulting in a fluorescently detectable change in the membrane potential of the acceptor vesicles. Using this approach we have studied the transfer properties of a range of lipids, varying both the headgroup and the chain length. At the low vesicle concentrations chosen, the transfer follows a first-order process where lipid monomers are transferred presumably through the aqueous solution phase from donor to acceptor vesicle. The rate of transfer decreases with increasing chain length which is consistent with energy models previously reported for lipid monomer vesicle interactions. Our assay improves on existing methods allowing the study of a range of unmodified lipids, continuous monitoring of transfer and simplified experimental procedures

    Instituciones de enseñanza superior de España y Brasil: temática sobre las personas con discapacidad

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    Las discusiones acerca de la población con discapacidades fueron insertadas en los cursos de Ciencias de la Actividad Física y Deporte y Educación Física como forma de atender a las disposiciones acordadas en diferentes documentos legales elaborados a lo largo de discusiones sobre el proceso de inclusión. Este proceso resultó en una mayor participación de ese grupo en otros ámbitos sociales entre ellos el deporte, el ocio y las competiciones. Eso nos llevó a preguntarnos cómo esta temática es abordada en los cursos citados. Para comprender este factor analizamos los planes docentes o programas de asignaturas de dos instituciones, una de Brasil y otra de España, que ofrecen estos cursos y que se destacan por la relevancia en el área en sus países. Observamos que la cantidad de horas de trabajo dedicado a la discusión sobre las personas con discapacidad es prácticamente la misma en los dos países, aunque la institución brasileña ofrezca mayor cantidad de asignaturas. Además notamos que la institución brasileña presenta repeticiones de temas que tratan específicamente de la etiología de la discapacidad. Las lecturas específicas indicadas en los programas pueden ser más diversificadas en algunas asignaturas. Por fin, notamos que apenas las asignaturas con temática específica sobre las personas con discapacidad las abordan. Creemos que los cursos pueden ofrecer más posibilidades de discusión sobre esta población en otras asignaturas, ya que las personas con discapacidad participan activamente de diversos espacios donde los profesionales de la Educación Física actúan

    Identification of the Schistosoma mansoni TNF-Alpha Receptor Gene and the Effect of Human TNF-Alpha on the Parasite Gene Expression Profile

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    Schistosoma mansoni is the major causative agent of schistosomiasis in the Americas. This parasite takes advantage of host signaling molecules such as cytokines and hormones to complete its development inside the host. Tumor necrosis factor-alpha (TNF-α) is one of the most important host cytokines involved in the inflammatory response. When cercariae, the infective stage, penetrates the human skin the release of TNF-α is started. In this work the authors describe the complete sequence of a possible TNF-α receptor in S. mansoni and detect that the receptor is most highly expressed in cercariae among all life cycle stages. Aiming to mimic the situation at the site of skin penetration, cercariae were mechanically transformed in vitro into schistosomula and exposed to human TNF-α. Exposure of early-developing schistosomula to the human hormone caused a large-scale change in the expression of parasite genes. Exposure of adult worms to human TNF-α caused gene expression changes as well, and the set of parasite altered genes in the adult parasite was different from that of schistosomula. This work increases the number of known signaling pathways of the parasite, and opens new perspectives into understanding the molecular components of TNF-α response as well as into possibly interfering with parasite–host interaction

    Study of the reaction e^{+}e^{-} -->J/psi\pi^{+}\pi^{-} via initial-state radiation at BaBar

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    We study the process e+e−→J/ψπ+π−e^+e^-\to J/\psi\pi^{+}\pi^{-} with initial-state-radiation events produced at the PEP-II asymmetric-energy collider. The data were recorded with the BaBar detector at center-of-mass energies 10.58 and 10.54 GeV, and correspond to an integrated luminosity of 454 fb−1\mathrm{fb^{-1}}. We investigate the J/ψπ+π−J/\psi \pi^{+}\pi^{-} mass distribution in the region from 3.5 to 5.5 GeV/c2\mathrm{GeV/c^{2}}. Below 3.7 GeV/c2\mathrm{GeV/c^{2}} the ψ(2S)\psi(2S) signal dominates, and above 4 GeV/c2\mathrm{GeV/c^{2}} there is a significant peak due to the Y(4260). A fit to the data in the range 3.74 -- 5.50 GeV/c2\mathrm{GeV/c^{2}} yields a mass value 4244±54244 \pm 5 (stat) ±4 \pm 4 (syst)MeV/c2\mathrm{MeV/c^{2}} and a width value 114−15+16114 ^{+16}_{-15} (stat)±7 \pm 7(syst)MeV\mathrm{MeV} for this state. We do not confirm the report from the Belle collaboration of a broad structure at 4.01 GeV/c2\mathrm{GeV/c^{2}}. In addition, we investigate the π+π−\pi^{+}\pi^{-} system which results from Y(4260) decay
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