6,904 research outputs found

    Guanosine nucleotides regulate B2 kinin receptor affinity of agonists but not of antagonists: Discussion of a model proposing receptor precoupling to G protein

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    The effect of nucleotides on binding of the B2 kinin (BK) receptor agonist {[}H-3]BK and the antagonist {[}H-3]NPC17731 to particulate fractions of human foreskin fibroblasts was studied. At 0 degrees C, particulate fractions exhibited a single class of binding sites with a Kd of 2.3 nM for {[}H-3]BK and a K-d Of 3.8 nM for the antagonist {[}H-3]NPC17731. Incubation with radioligands at 37 degrees C for 5 min gave a reduction of agonist, as well as antagonist, binding that was between 0-40% depending on the preparation, even in the absence of guanosine nucleotides. As shown by Scatchard analysis, this reduction in specific binding was due to a shift in the affinity of at least a fraction of the receptors. The presence at 37 degrees C of the guanine nucleotides GTP, GDP and their poorly hydrolyzable analogs left {[}H-3]-NPC17731 binding unaffected, but reduced the receptor affinity for {[}H-3]BK to a K-d Of about 15 nM. The maximal number of receptors, however, was unchanged. This affinity change was strongly dependent on the presence of bivalent cations, in particular Mg2+. It was reversed by incubation at 0 degrees C, The rank order of the guanosine nucleotides for {[}H-3]BK binding reduction was GTP{[}gamma S] = Gpp{[}NH]p > GTP = GDP > GDP{[}beta S]. GMP, ATP, ADP and AMP showed no influence on agonist binding. A model for the interaction of the B2 kinin receptor with G proteins is discussed

    Using Q methodology:Sorting out subjectivity in educational research

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    Understanding subjective perspectives and lived experiences of different stakeholders can improve pupils’ learning environment in compulsory school settings. Q methodology is an inherently mixed method approach and regarded as the basis for the science of subjectivity. The present paper reviewed recent Q methodological publications in compulsory education research. Seventy-four studies reporting from context in twenty countries met the inclusion criteria and showed a wide-ranging and diverse application of the research methodology. The subjectivity of teachers, pupils and others were explored on topics related to the science of learning and development and teacher characteristics. This review showcases how Q methodology is applied to access subjectivity in educational research and provides an overview of Q methodological find- ings and implications for the field. The wide range of the application of Q studies in compulsory education attests to the flexibility and suitability of this research method in educational research

    Building Healthy Communities in the Dominican Republic: A Mixed-Methods Approach towards Engaging the Community

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    Breakout Session 1C: The Building Healthy Communities Creative Inquiry is an ongoing undergraduate and graduate student-led project from Clemson University. Its goal is to facilitate community-driven improvement of a small rural community in the Dominican Republic, Las Malvinas II. We strive to address five public health priorities, identified in consultation with the community, including vaccine-preventable diseases, chronic diseases, education, sanitation, and unwanted pregnancies. To address these areas for improvement, our research used a mixed-methods approach, using both qualitative and quantitative data gathering tools. Qualitative methods included focus groups and interviews with community leaders and relevant governmental and non-governmental organizations from five different sectors, including work, education, community institutions/organizations, health care, and community-at-large sector. The findings were then analyzed to create a Community Health Assessment. For quantitative methods we utilized arcGIS technology. Students created surveys based on health priorities and mapped a comprehensive survey including any personal assets the community household members may have. In spring 2018, students will conduct a photovoice project with the youth of the community

    Frequency of Tongue Cleaning Impacts the Human Tongue Microbiome Composition and Enterosalivary Circulation of Nitrate

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    The oral microbiome has the potential to provide an important symbiotic function in human blood pressure physiology by contributing to the generation of nitric oxide (NO), an essential cardiovascular signaling molecule. NO is produced by the human body via conversion of arginine to NO by endogenous nitric oxide synthase (eNOS) but eNOS activity varies by subject. Oral microbial communities are proposed to supplement host NO production by reducing dietary nitrate to nitrite via bacterial nitrate reductases. Unreduced dietary nitrate is delivered to the oral cavity in saliva, a physiological process termed the enterosalivary circulation of nitrate. Previous studies demonstrated that disruption of enterosalivary circulation via use of oral antiseptics resulted in increases in systolic blood pressure. These previous studies did not include detailed information on the oral health of enrolled subjects. Using 16S rRNA gene sequencing and analysis, we determined whether introduction of chlorhexidine antiseptic mouthwash for 1 week was associated with changes in tongue bacterial communities and resting systolic blood pressure in healthy normotensive individuals with documented oral hygiene behaviors and free of oral disease. Tongue cleaning frequency was a predictor of chlorhexidine-induced changes in systolic blood pressure and tongue microbiome composition. Twice-daily chlorhexidine usage was associated with a significant increase in systolic blood pressure after 1 week of use and recovery from use resulted in an enrichment in nitrate-reducing bacteria on the tongue. Individuals with relatively high levels of bacterial nitrite reductases had lower resting systolic blood pressure. These results further support the concept of a symbiotic oral microbiome contributing to human health via the enterosalivary nitrate-nitrite-NO pathway. These data suggest that management of the tongue microbiome by regular cleaning together with adequate dietary intake of nitrate provide an opportunity for the improvement of resting systolic blood pressure

    Heightened immune response to autocitrullinated porphyromonas gingivalis peptidylarginine deiminase: a potential mechanism for breaching immunologic tolerance in rheumatoid arthritis

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    Background: Rheumatoid arthritis (RA) is characterised by autoimmunity to citrullinated proteins, and there is increasing epidemiologic evidence linking Porphyromonas gingivalis to RA. P gingivalis is apparently unique among periodontal pathogens in possessing a citrullinating enzyme, peptidylarginine deiminase (PPAD) with the potential to generate antigens driving the autoimmune response. Objectives: To examine the immune response to PPAD in patients with RA, individuals with periodontitis (PD) and controls (without arthritis), confirm PPAD autocitrullination and identify the modified arginine residues. Methods: PPAD and an inactivated mutant (C351A) were cloned and expressed and autocitrullination of both examined by immunoblotting and mass spectrometry. ELISAs using PPAD, C351A and another P gingivalis protein arginine gingipain (RgpB) were developed and antibody reactivities examined in patients with RA (n=80), individuals with PD (n=44) and controls (n=82). Results: Recombinant PPAD was a potent citrullinating enzyme. Antibodies to PPAD, but not to Rgp, were elevated in the RA sera (median 122 U/ml) compared with controls (median 70 U/ml; p<0.05) and PD (median 60 U/ml; p<0.01). Specificity of the anti-peptidyl citrullinated PPAD response was confirmed by the reaction of RA sera with multiple epitopes tested with synthetic citrullinated peptides spanning the PPAD molecule. The elevated antibody response to PPAD was abolished in RA sera if the C351A mutant was used on ELISA. Conclusions: The peptidyl citrulline-specific immune response to PPAD supports the hypothesis that, as a bacterial protein, it might break tolerance in RA, and could be a target for therapy

    ECONOMIA DO ESTADO NA APLICAÇÃO DO PRINCÍPIO DA INSIGNIFICÂNCIA

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    O presente artigo tem por finalidade apresentar concepções sobre a Autoridade Policial como primeira guardiã de direitos e garantias individuais em virtude dos princípios constitucionais e tratados internacionais ratificados pela República Federativa Brasileira, traz a possibilidade da aplicação do Princípio da Insignificância pela Autoridade Policial sem diminuir a autoridade, de direito, do judiciário. O Princípio da Insignificância, no que pese, não ter sua conceituação expressa nas Leis brasileiras, vem se fortalecendo ao passar dos tempos, e a sua aplicabilidade, bem como o seu reconhecimento, é cada vez mais presente na jurisprudência e na doutrina. No entanto a sua aplicação pela Polícia Judiciária ainda é pouco discutida pelo mundo jurídico. Surge então, a possibilidade e benefício não só para a sociedade, mas como também, para o sistema processual penal como um todo, que os Delegados de Polícia fazendo seu juízo de valor, decidam acerca da lavratura, ou não, do auto de prisão em flagrante de fatos que não prejudiquem significativamente os bens jurídicos tutelados, como a vida, a honra, a liberdade, etc, sendo obviamente atípicos, isto com base e fundamento no Princípio da Insignificância. O ato de abranger a competência da aplicação do Princípio da Insignificância pela Polícia Judiciária, não significa que o Estado, representado pela sua polícia, fechará os olhos aos crimes insignificantes, mas sim, o interesse do Estado em preservar ao máximo a liberdade, a integridade física, a dignidade e a vida das pessoas, tratando tais fatos de forma razoável e proporcional, já na fase investigativa

    GM-CSF Inhibits c-Kit and SCF Expression by Bone Marrow-Derived Dendritic Cells.

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    Stem cell factor (SCF), the ligand of c-kit, is a key cytokine for hematopoiesis. Hematopoietic precursors express c-kit, whereas differentiated cells of hematopoietic lineage are negative for this receptor, with the exception of NK cells, mast cells, and a few others. While it has long been recognized that dendritic cells (DCs) can express c-kit, several questions remain concerning the SCF/c-kit axis in DCs. This is particularly relevant for DCs found in those organs wherein SCF is highly expressed, including the bone marrow (BM). We characterized c-kit expression by conventional DCs (cDCs) from BM and demonstrated a higher proportion of c-kit+ cells among type 1 cDC subsets (cDC1s) than type 2 cDC subsets (cDC2s) in both humans and mice, whereas similar levels of c-kit expression were observed in cDC1s and cDC2s from mouse spleen. To further study c-kit regulation, DCs were generated with granulocyte-macrophage colony-stimulating factor (GM-CSF) from mouse BM, a widely used protocol. CD11c+ cells were purified from pooled non-adherent and slightly adherent cells collected after 7 days of culture, thus obtaining highly purified BM-derived DCs (BMdDCs). BMdDCs contained a small fraction of c-kit+ cells, and by replating them for 2 days with GM-CSF, we obtained a homogeneous population of c-kit+ CD40hi MHCIIhi cells. Not only did BMdDCs express c-kit but they also produced SCF, and both were striking upregulated if GM-CSF was omitted after replating. Furthermore, a small but significant reduction in BMdDC survival was observed upon SCF silencing. Incubation of BMdDCs with SCF did not modulate antigen presentation ability of these cells, nor it did regulate their membrane expression of the chemokine receptor CXCR4. We conclude that the SCF/c-kit-mediated prosurvival circuit may have been overlooked because of the prominent use of GM-CSF in DC cultures in vitro, including those human DC cultures destined for the clinics. We speculate that DCs more prominently rely on SCF in vivo in some microenvironments, with potential implications for graft-versus-host disease and antitumor immunity

    Dark Matter Disc Enhanced Neutrino Fluxes from the Sun and Earth

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    As disc galaxies form in a hierarchical cosmology, massive merging satellites are preferentially dragged towards the disc plane. The material accreted from these satellites forms a dark matter disc that contributes 0.25 - 1.5 times the non-rotating halo density at the solar position. Here, we show the importance of the dark disc for indirect dark matter detection in neutrino telescopes. Previous predictions of the neutrino flux from WIMP annihilation in the Earth and the Sun have assumed that Galactic dark matter is spherically distributed with a Gaussian velocity distribution, the standard halo model. Although the dark disc has a local density comparable to the dark halo, its higher phase space density at low velocities greatly enhances capture rates in the Sun and Earth. For typical dark disc properties, the resulting muon flux from the Earth is increased by three orders of magnitude over the SHM, while for the Sun the increase is an order of magnitude. This significantly increases the sensitivity of neutrino telescopes to fix or constrain parameters in WIMP models. The flux from the Earth is extremely sensitive to the detailed properties of the dark disc, while the flux from the Sun is more robust. The enhancement of the muon flux from the dark disc puts the search for WIMP annihilation in the Earth on the same level as the Sun for WIMP masses < 100 GeV.Comment: 7 pages, 4 figures, added a short paragraph to the discussion section, conclusions unchanged, published versio
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