657 research outputs found

    Living better in a better world: Guidance and counselling in an ecosystemic model of culture

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    Diagnosis and prognosis of current problems take into account the connections (assets) and ruptures (deficits) between the different dimensions of being-in-the-world, mutually entangled as donors and recipients: intimate; interactive; social and biophysical. Guidance and counselling consider the complex and dynamic configurations formed by the intertwining of the different dimensions, as they combine to produce the events. Cultural and epistemic backgrounds, subject-object relationships, assumptions and conflicts, are examined by heuristic-hermeneutic processes, as new support structures emerge in the socio-cultural learning niches. Problems related to education, culture, ethics, physical, social and mental well-being, natural and man-made environment are treated as ecosystemic configurations, not as separate objects of separate programmes. Values, goals, and principles are considered in the transition from a non-ecosystemic to an ecosystemic model of culture. The proposal presents not only a descriptive position, but also a normative position, a framework for the development and evaluation of public policies and research and teaching programmes, critically inquiring into the prevailing assumptions of growth, power, wealth, work and freedom.education; culture; environment; ecosystemic; guidance; counselling

    Revisiting aminocoumarins for the treatment of melioidosis.

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    Burkholderia pseudomallei causes melioidosis, a potentially lethal disease that can establish both chronic and acute infections in humans. It is inherently recalcitrant to many antibiotics, there is a paucity of effective treatment options and there is no vaccine. In the present study, the efficacies of selected aminocoumarin compounds, DNA gyrase inhibitors that were discovered in the 1950s but are not in clinical use for the treatment of melioidosis were investigated. Clorobiocin and coumermycin were shown to be particularly effective in treating B. pseudomallei infection in vivo. A novel formulation with dl-tryptophan or l-tyrosine was shown to further enhance aminocoumarin potency in vivo. It was demonstrated that coumermycin has superior pharmacokinetic properties compared with novobiocin, and the coumermycin in l-tyrosine formulation can be used as an effective treatment for acute respiratory melioidosis in a murine model. Repurposing of existing approved antibiotics offers new resources in a challenging era of drug development and antimicrobial resistance

    Living better in a better world: Guidance and counselling in an ecosystemic model of culture

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    Diagnosis and prognosis of current problems take into account the connections (assets) and ruptures (deficits) between the different dimensions of being-in-the-world, mutually entangled as donors and recipients: intimate; interactive; social and biophysical. Guidance and counselling consider the complex and dynamic configurations formed by the intertwining of the different dimensions, as they combine to produce the events. Cultural and epistemic backgrounds, subject-object relationships, assumptions and conflicts, are examined by heuristic-hermeneutic processes, as new support structures emerge in the socio-cultural learning niches. Problems related to education, culture, ethics, physical, social and mental well-being, natural and man-made environment are treated as ecosystemic configurations, not as separate objects of separate programmes. Values, goals, and principles are considered in the transition from a non-ecosystemic to an ecosystemic model of culture. The proposal presents not only a descriptive position, but also a normative position, a framework for the development and evaluation of public policies and research and teaching programmes, critically inquiring into the prevailing assumptions of growth, power, wealth, work and freedom

    Reconnecting the Broken Bonds: Environment, Politics, Economics and the State of the World

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    An ecosystem theoretical and practical framework is posited for the evaluation and planning of advocacy, communication, public policies, research and teaching programmers, intertwining four dimensions of being-in-the-world (intimate, interactive, social and biophysical), as they combine, as donors and recipients, to induce the events (deficits/assets), cope with consequences (desired/undesired) and contribute for change (potential outputs). Earth’s regeneration and mankind’s regeneration, as faces of the same coin, are addressed simultaneously, in space and time, for their mutual support. Goals and new paths to reach them contemplate a set of values, norms and policies that prioritizes socio-ecological objectives, human well-being, natural and built environments, the aesthetic, ethical and cultural meaning of the existence

    Living better in a better world: Guidance and counselling in an ecosystemic model of culture

    Get PDF
    Diagnosis and prognosis of current problems take into account the connections (assets) and ruptures (deficits) between the different dimensions of being-in-the-world, mutually entangled as donors and recipients: intimate; interactive; social and biophysical. Guidance and counselling consider the complex and dynamic configurations formed by the intertwining of the different dimensions, as they combine to produce the events. Cultural and epistemic backgrounds, subject-object relationships, assumptions and conflicts, are examined by heuristic-hermeneutic processes, as new support structures emerge in the socio-cultural learning niches. Problems related to education, culture, ethics, physical, social and mental well-being, natural and man-made environment are treated as ecosystemic configurations, not as separate objects of separate programmes. Values, goals, and principles are considered in the transition from a non-ecosystemic to an ecosystemic model of culture. The proposal presents not only a descriptive position, but also a normative position, a framework for the development and evaluation of public policies and research and teaching programmes, critically inquiring into the prevailing assumptions of growth, power, wealth, work and freedom

    Challenges in Chagas Disease Drug Development.

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    The protozoan parasite Trypanosoma cruzi causes Chagas disease, an important public health problem throughout Latin America. Current therapeutic options are characterised by limited efficacy, long treatment regimens and frequent toxic side-effects. Advances in this area have been compromised by gaps in our knowledge of disease pathogenesis, parasite biology and drug activity. Nevertheless, several factors have come together to create a more optimistic scenario. Drug-based research has become more systematic, with increased collaborations between the academic and commercial sectors, often within the framework of not-for-profit consortia. High-throughput screening of compound libraries is being widely applied, and new technical advances are helping to streamline the drug development pipeline. In addition, drug repurposing and optimisation of current treatment regimens, informed by laboratory research, are providing a basis for new clinical trials. Here, we will provide an overview of the current status of Chagas disease drug development, highlight those areas where progress can be expected, and describe how fundamental research is helping to underpin the process

    Determination of the volume-specific surface area by using transmission electron tomography for characterization and definition of nanomaterials

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    <p>Abstract</p> <p>Background</p> <p>Transmission electron microscopy (TEM) remains an important technique to investigate the size, shape and surface characteristics of particles at the nanometer scale. Resulting micrographs are two dimensional projections of objects and their interpretation can be difficult. Recently, electron tomography (ET) is increasingly used to reveal the morphology of nanomaterials (NM) in 3D. In this study, we examined the feasibility to visualize and measure silica and gold NM in suspension using conventional bright field electron tomography.</p> <p>Results</p> <p>The general morphology of gold and silica NM was visualized in 3D by conventional TEM in bright field mode. In orthoslices of the examined NM the surface features of a NM could be seen and measured without interference of higher or lower lying structures inherent to conventional TEM. Segmentation by isosurface rendering allowed visualizing the 3D information of an electron tomographic reconstruction in greater detail than digital slicing. From the 3D reconstructions, the surface area and the volume of the examined NM could be estimated directly and the volume-specific surface area (VSSA) was calculated. The mean VSSA of all examined NM was significantly larger than the threshold of 60 m<sup>2</sup>/cm<sup>3</sup>.</p> <p>The high correlation between the measured values of area and volume gold nanoparticles with a known spherical morphology and the areas and volumes calculated from the equivalent circle diameter (ECD) of projected nanoparticles (NP) indicates that the values measured from electron tomographic reconstructions are valid for these gold particles.</p> <p>Conclusion</p> <p>The characterization and definition of the examined gold and silica NM can benefit from application of conventional bright field electron tomography: the NM can be visualized in 3D, while surface features and the VSSA can be measured.</p

    In Vivo Analysis of Trypanosoma cruzi Persistence Foci at Single-Cell Resolution

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    Infections with Trypanosoma cruzi are usually lifelong despite generating a strong adaptive immune response. Identifying the sites of parasite persistence is therefore crucial to understanding how T. cruzi avoids immune-mediated destruction. However, this is a major technical challenge, because the parasite burden during chronic infections is extremely low. Here, we describe an integrated approach involving comprehensive tissue processing, ex vivo imaging, and confocal microscopy, which allowed us to visualize infected host cells in murine tissue with exquisite sensitivity. Using bioluminescence-guided tissue sampling, with a detection level of 200 parasites, which we term mega-nests. In contrast, during the acute stage, when the total parasite burden is considerably higher and many cells are infected, nests containing >50 parasites are rarely found. In C3H/HeN mice, but not BALB/c mice, we identified skeletal muscle as a major site of persistence during the chronic stage, with most parasites being found in large mega-nests within the muscle fibers. Finally, we report that parasites are also frequently found in the skin during chronic murine infections, often in multiple infection foci. In addition to being a site of parasite persistence, this anatomical reservoir could play an important role in insect-mediated transmission and have implications for drug development.IMPORTANCETrypanosoma cruzi causes Chagas disease, the most important parasitic infection in Latin America. Major pathologies include severe damage to the heart and digestive tract, although symptoms do not usually appear until decades after infection. Research has been hampered by the complex nature of the disease and technical difficulties in locating the extremely low number of parasites. Here, using highly sensitive imaging technology, we reveal the sites of parasite persistence during chronic-stage infections of experimental mice at single-cell resolution. We show that parasites are frequently located in smooth muscle cells in the circular muscle layer of the colon and that skeletal muscle cells and the skin can also be important reservoirs. This information provides a framework for investigating how the parasite is able to survive as a lifelong infection, despite a vigorous immune response. It also informs drug development strategies by identifying tissue sites that must be accessed to achieve a curative outcome

    The first minutes in the life of a peroxisomal matrix protein

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    In the field of intracellular protein sorting, peroxisomes are most famous by their capacity to import oligomeric proteins. The data supporting this remarkable property are abundant and, understandably, have inspired a variety of hypothetical models on how newly synthesized (cytosolic) proteins reach the peroxisome matrix. However, there is also accumulating evidence suggesting that many peroxisomal oligomeric proteins actually arrive at the peroxisome still as monomers. In support of this idea, recent data suggest that PEX5, the shuttling receptor for peroxisomal matrix proteins, is also a chaperone/holdase, binding newly synthesized peroxisomal proteins in the cytosol and blocking their oligomerization. Here we review the data behind these two different perspectives and discuss their mechanistic implications on this protein sorting pathway. This article is part of a Special Issue entitled: Peroxisomes edited by Ralf Erdmann.This work was supported by national funds through FCT – Fundação para a Ciência e a Tecnologia/MEC-Ministério da Educação e Ciência and when applicable co-funded by FEDER funds within the partnership agreement PT2020 related with the research unit number 4293; and by the project FCOMP-01-0124-FEDER-019731 (PTDC/BIABCM/118577/2010) funded by national funds through FCT and co-funded by Fundo Europeu de Desenvolvimento Regional (FEDER) through the Operation- alCompetitiveness Programme(COMPETE).A. F.D., T.F., T.A.R. and C. P. G. were supported by FCT, Programa Operacional Potencial Humano (POPH) do Quadro de Referência Estratégico Nacional (QREN), and Fundo Social Europeu (FSE)

    A cell-free organelle-based in vitro system for studying the peroxisomal protein import machinery

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    Here we describe a protocol to dissect the peroxisomal matrix protein import pathway using a cell-free in vitro system. The system relies on a postnuclear supernatant (PNS), which is prepared from rat/mouse liver, to act as a source of peroxisomes and cytosolic components. A typical in vitro assay comprises the following steps: (i) incubation of the PNS with an in vitro-synthesized 35 S-labeled reporter protein; (ii) treatment of the organelle suspension with a protease that degrades reporter proteins that have not associated with peroxisomes; and (iii) SDS-PAGE/autoradiography analysis. To study transport of proteins into peroxisomes, it is possible to use organelle-resident proteins that contain a peroxisomal targeting signal (PTS) as reporters in the assay. In addition, a receptor (PEX5L/S or PEX5L.PEX7) can be used to report the dynamics of shuttling proteins that mediate the import process. Thus, different but complementary perspectives on the mechanism of this pathway can be obtained. We also describe strategies to fortify the system with recombinant proteins to increase import yields and block specific parts of the machinery at a number of steps. The system recapitulates all the steps of the pathway, including mono-ubiquitination of PEX5L/S at the peroxisome membrane and its ATP-dependent export back into the cytosol by PEX1/PEX6. An in vitro import(/export) experiment can be completed in 24 h.We thank M. Fransen, Katholieke Universiteit-Leuven, for critical comments on the manuscript and for the plasmid encoding histidine-tagged PEX19. We thank P. van Veldhoven, Katholieke Universiteit-Leuven, and P. Maciel, Universidade do Minho, for the expression plasmids encoding prePHYH and GST-Ub, respectively. This work was funded by FEDER—Fundo Europeu de Desenvolvimento Regional through the COMPETE 2020—Operacional Programme for Competitiveness and Internationalization (POCI), Portugal 2020, Portugal’s FCT—Fundação para a Ciência e a Tecnologia/ Ministério da Ciência, Tecnologia e Inovação in the framework of the projects ‘The molecular mechanism of protein import into peroxisomes’ (FCOMP-01-0124-FEDER-019731-PTDC/BIA-BCM/118577/2010), ‘Institute for Research and Innovation in Health Sciences’ (POCI-01-0145-FEDER-007274) and ‘The molecular mechanisms of peroxisome biogenesis’ (PTDC /BEX-BC M/2311/2014) and Norte 2020—Programa Operacional Regional do Norte, under the application of the ‘Porto Neurosciences and Neurologic Disease Research Initiative at i3S (NORTE-01-0145-FEDER-000008)’, awarded to J.E.A. T.A.R., T.F., A.F.D. and C.P.G. were supported by Fundação para a Ciência e a Tecnologia, Programa Operacional Potencial Humano do QREN and Fundo Social Europeu
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