9,597 research outputs found

    Meio ambiente e arena pública: governança ambiental e suas implicações para as políticas públicas

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    This is the final version of the article. Available from the publisher via the DOI in this record.O quadro institucional da sociedade contemporânea se alterou, uma vez que a fronteira entre a esfera do público e do privado se torna cada vez mais fluida, isto é, o Estado não é mais o único ator a regular o comportamento dos agentes sociais, muito menos a desenvolver questões sobre o que é público. Isso não é diferente quando se trata de questões ambientais. Nesse contexto, este artigo tem o objetivo de apontar uma abordagem sobre as ações públicas para o meio ambiente com base no exame das experiências do banco de dados do programa Gestão Pública e Cidadania e das ações recentes da Rede Amigos da Amazônia. Concluiu-se que tal abordagem deve considerar pelo menos três elementos: transversalidade, uma vez que os impactos ambientais envolvem diferentes áreas do conhecimento e da ação governamental; não neutralidade, considerando que a compreensão dos impactos ambientais passa por uma negociação na arena pública; governança, haja vista que a temática ambiental requer a articulação e o relacionamento de diferentes atores

    A yeast three-hybrid system that reconstitutes mammalian hypoxia inducible factor regulatory machinery

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    Background: Several human pathologies, including neoplasia and ischemic cardiovascular diseases, course with an unbalance between oxygen supply and demand ( hypoxia). Cells within hypoxic regions respond with the induction of a specific genetic program, under the control of the Hypoxia Inducible Factor (HIF), that mediates their adaptation to the lack of oxygen. The activity of HIF is mainly regulated by the EGL-nine homolog (EGLN) enzymes that hydroxylate the alpha subunit of this transcription factor in an oxygen-dependent reaction. Hydroxylated HIF is then recognized and ubiquitinilated by the product of the tumor suppressor gene, pVHL, leading to its proteosomal degradation. Under hypoxia, the hydroxylation of HIF by the EGLNs is compromised due to the lack of oxygen, which is a reaction cosubstrate. Thus, HIF escapes degradation and drives the transcription of its target genes. Since the progression of the aforementioned pathologies might be influenced by activation of HIF-target genes, development of small molecules with the ability to interfere with the HIF-regulatory machinery is of great interest.Results: Herein we describe a yeast three-hybrid system that reconstitutes mammalian HIF regulation by the EGLNs and VHL. In this system, yeast growth, under specific nutrient restrictions, is driven by the interaction between the beta domain of VHL and a hydroxyproline-containing HIF alpha peptide. In turn, this interaction is strictly dependent on EGLN activity that hydroxylates the HIFa peptide. Importantly, this system accurately preserves the specificity of the hydroxylation reaction toward specific substrates. We propose that this system, in combination with a matched control, can be used as a simple and inexpensive assay to identify molecules that specifically modulate EGLN activity. As a proof of principle we show that two known EGLN inhibitors, dimethyloxaloylglycine (DMOG) and 6-chlor-3-hydroxychinolin-2-carbonic acid-N-carboxymethylamide (S956711), have a profound and specific effect on the yeast HIF/EGLN/VHL system.Conclusion: The system described in this work accurately reconstitutes HIF regulation while preserving EGLN substrate specificity. Thus, it is a valuable tool to study HIF regulation, and particularly EGLN biochemistry, in a cellular context. In addition, we demonstrate that this system can be used to identify specific inhibitors of the EGLN enzymes

    Acute Hemorrhagic Edema of Infancy

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    Acute Hemorrhagic Edema of Infancy is a small vessel leucocytoclastic vasculitis affecting young infants. It is characterized by large, target-like, macular to purpuric plaques predominantly affecting the face, ear lobes and extremities. Non-pitting edema of the distal extremities and low-grade fever may also be present. Extra-cutaneous involvement is very rare. Although the lesions have a dramatic onset in a twenty-four to forty-eight hour period, usually the child has a non-toxic appearance. In most cases there are no changes in laboratory parameters. The cutaneous biopsy reveals an inflammatory perivascular infiltrate. It is a benign and auto-limited disease, with complete resolution within two to three weeks leaving no sequelae in the majority of cases. No recurrences are described. We report a case of a 42-day old girl admitted at our hospital with Acute Hemorrhagic Edema of Infancy.info:eu-repo/semantics/publishedVersio

    Factores que inciden en la práctica de actividad física de la población en situación de discapacidad

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    El presente documento es el resumen de la propuesta técnica del proyecto de investigación denominado Determinantes de la práctica de actividad física en personas con discapacidad, sus familias, cuidadoras y cuidadores en Bogotá, fruto de la apuesta académica desarrollada por un equipo de investigadoras de los grupos de investigación en Actividad Física y Desarrollo Humano, y en Rehabilitación e Integración Social de la Persona con Discapacidad, de la Facultad de Rehabilitación y Desarrollo Humano, de la Universidad del Rosario. El proyecto de investigación obtuvo la financiación del Fondo de Investigaciones de la Universidad del Rosario (FIUR), para ser desarrollado durante el período de julio de 2008 a junio de 2009

    Methamphetamine abstinence induces changes in μ-opioid receptor, oxytocin and CRF systems: Association with an anxiogenic phenotype

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    The major challenge in treating methamphetamine addicts is the maintenance of a drug free-state since they experience negative emotional symptoms during abstinence, which may trigger relapse. The neuronal mechanisms underlying long-term withdrawal and relapse are currently not well-understood. There is evidence suggesting a role of the oxytocin (OTR), μ-opioid receptor (MOPr), dopamine D2 receptor (D2R), corticotropin-releasing factor (CRF) systems and the hypothalamic-pituitary-adrenal (HPA)-axis in the different stages of methamphetamine addiction. In this study, we aimed to characterize the behavioral effects of methamphetamine withdrawal in mice and to assess the modulation of the OTR, MOPr, D2R, CRF and HPA-axis following chronic methamphetamine administration and withdrawal. Ten-day methamphetamine administration (2 mg/kg) increased OTR binding in the amygdala, whilst 7 days of withdrawal induced an upregulation of this receptor in the lateral septum. Chronic methamphetamine treatment increased plasma OT levels that returned to control levels following withdrawal. In addition, methamphetamine administration and withdrawal increased striatal MOPr binding, as well as c-Fos+/CRF+ neuronal expression in the amygdala, whereas an increase in plasma corticosterone levels was observed following METH administration, but not withdrawal. No differences were observed in the D2R binding following METH administration and withdrawal. The alterations in the OTR, MOPr and CRF systems occurred concomitantly with the emergence of anxiety-related symptoms and the development of psychomotor sensitization during withdrawal. Collectively, our findings indicate that chronic methamphetamine use and abstinence can induce brain-region specific neuroadaptations of the OTR, MOPr and CRF systems, which may, at least, partly explain the withdrawal-related anxiogenic effects

    Uniportal robotic-assisted thoracic surgery for mediastinal tumors

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    Survivin as a therapeutic target in Sonic hedgehog-driven medulloblastoma.

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    Medulloblastoma (MB) is a highly malignant brain tumor that occurs primarily in children. Although surgery, radiation and high-dose chemotherapy have led to increased survival, many MB patients still die from their disease, and patients who survive suffer severe long-term side effects as a consequence of treatment. Thus, more effective and less toxic therapies for MB are critically important. Development of such therapies depends in part on identification of genes that are necessary for growth and survival of tumor cells. Survivin is an inhibitor of apoptosis protein that regulates cell cycle progression and resistance to apoptosis, is frequently expressed in human MB and when expressed at high levels predicts poor clinical outcome. Therefore, we hypothesized that Survivin may have a critical role in growth and survival of MB cells and that targeting it may enhance MB therapy. Here we show that Survivin is overexpressed in tumors from patched (Ptch) mutant mice, a model of Sonic hedgehog (SHH)-driven MB. Genetic deletion of survivin in Ptch mutant tumor cells significantly inhibits proliferation and causes cell cycle arrest. Treatment with small-molecule antagonists of Survivin impairs proliferation and survival of both murine and human MB cells. Finally, Survivin antagonists impede growth of MB cells in vivo. These studies highlight the importance of Survivin in SHH-driven MB, and suggest that it may represent a novel therapeutic target in patients with this disease

    How and why DNA barcodes underestimate the diversity of microbial eukaryotes

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    Background: Because many picoplanktonic eukaryotic species cannot currently be maintained in culture, direct sequencing of PCR-amplified 18S ribosomal gene DNA fragments from filtered sea-water has been successfully used to investigate the astounding diversity of these organisms. The recognition of many novel planktonic organisms is thus based solely on their 18S rDNA sequence. However, a species delimited by its 18S rDNA sequence might contain many cryptic species, which are highly differentiated in their protein coding sequences. Principal Findings: Here, we investigate the issue of species identification from one gene to the whole genome sequence. Using 52 whole genome DNA sequences, we estimated the global genetic divergence in protein coding genes between organisms from different lineages and compared this to their ribosomal gene sequence divergences. We show that this relationship between proteome divergence and 18S divergence is lineage dependant. Unicellular lineages have especially low 18S divergences relative to their protein sequence divergences, suggesting that 18S ribosomal genes are too conservative to assess planktonic eukaryotic diversity. We provide an explanation for this lineage dependency, which suggests that most species with large effective population sizes will show far less divergence in 18S than protein coding sequences. Conclusions: There is therefore a trade-off between using genes that are easy to amplify in all species, but which by their nature are highly conserved and underestimate the true number of species, and using genes that give a better description of the number of species, but which are more difficult to amplify. We have shown that this trade-off differs between unicellular and multicellular organisms as a likely consequence of differences in effective population sizes. We anticipate that biodiversity of microbial eukaryotic species is underestimated and that numerous ''cryptic species'' will become discernable with the future acquisition of genomic and metagenomic sequences

    Membrane-Bound TNF Induces Protective Immune Responses to M. bovis BCG Infection: Regulation of memTNF and TNF Receptors Comparing Two memTNF Molecules

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    Several activities of the transmembrane form of TNF (memTNF) in immune responses to intracellular bacterial infection have been shown to be different from those exerted by soluble TNF. Evidence is based largely on studies in transgenic mice expressing memTNF, but precise cellular mechanisms are not well defined and the importance of TNF receptor regulation is unknown. In addition, memTNF activities are defined for a particular modification of the extracellular domain of TNF but a direct comparison of different mutant memTNF molecules has not been done in vivo
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