13,766 research outputs found

    Identification of stromal cells in spleen which support myelopoiesis

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    Stromal cells in spleen organize tissue into red pulp, white pulp and marginal zone, and also interact with hematopoietic cells to regulate immune responses. This study has used phenotypic information of a previously described spleen stromal cell line called 5G3, which supports restricted hematopoiesis in vitro, to identify an equivalent stromal cell subset in vivo and to test its capacity to support hematopoiesis. Using stromal cell fractionation, phenotypic analysis, as well as cell growth and hematopoietic support assays, the Sca-1+gp38+Thy1.2+CD29+CD51+ fraction of spleen stroma has been identified as an equivalent stromal subset resembling the 5G3 cell counterpart. While heterogeneity may still exist within that subset, it has been shown to have superior hematopoietic support capacity compared with the 5G3 cell line, and all other spleen stromal cell fractions tested.This work was supported by project grants to HO from the Australian Research Council (#DP130101703) and the National Health and Medical Research Council of Australia (#585443). HL was supported by an Australian National University Postgraduate Scholarship

    Decision-making regarding total knee replacement surgery: a qualitative meta-synthesis

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    Knee osteoarthritis is a highly prevalent condition that can result in disability and reduced quality of life. The evidence suggests that total knee replacement surgery (TKR) is an effective intervention for patients with severe knee problems, but there is also an unmet need for this treatment in the UK. To help understand the reason for this unmet need, the aim of this study was to explore the factors that influence the decision-making process of TKR surgery by synthesising the available evidence from qualitative research on this topic

    Towards a sustainable economy? Socio-technical transitions in the green building sector

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    Making the transition to a green economy is a major policy driver in the UK and other countries. Entrepreneurs are suggested as being at the forefront of this transition and as a driving force for sustainability. These “green entrepreneurs” may represent a new type of entrepreneurial behaviour combining economic, environmental and social aims. In this paper, we present empirical work conducted with green entrepreneurs in the UK green building sector. Buildings have significant impacts on the environment, both in terms of materials and post-construction energy demands. Drawing on sustainability transitions theory, we examine the role of green entrepreneurs in affecting change and suggest that green building niches are less consensual than previously theorised. In theorising green entrepreneurs, we also point to the need to consider them within wider networks of activity rather than as lone actors and the implications this has for policy

    MCSF drives regulatory DC development in stromal co-cultures supporting hematopoiesis

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    Background: Splenic stroma overlaid with hematopoietic progenitors supports in vitro hematopoiesis with production of dendritic-like cells. Co-cultures of murine lineage-depleted bone marrow over the 5G3 stromal line produce two populations of cells, characterised as CD11b+CD11c+MHC-II− dendritic-like ‘L-DC’, and CD11b+CD11c+ MHC-II+ cells, resembling conventional dendritic cells (cDC). To date, the functional capacity of these two subsets has not been clearly distinguished. Results: Here we show both the L-DC and cDC-like subsets can be activated and induce proliferation of OT-I CD8+ T cells, being strong inducers of IL-2 and IFN-γ production. Both subsets lack ability to induce proliferation of OT-II CD4+ T cells. The cDC-like population is shown here to resemble regulatory DC in that they induce FoxP3 expression and IL10 production in OT-II CD4+ T cells, in line with their function as regulatory DC. L-DC did not activate or induce the proliferation of CD4+ T cells and did not induce FoxP3 expression in CD4+ T cells. L-DC can be distinguished from cDClike cells through their superior endocytic capacity and expression of 4-1BBL, F4/80 and Sirp-α. A comparison of gene expression by the two subsets was consistent with L-DC having an activated or immunostimulatory DC phenotype, while cDC-like cells reflect myeloid dendritic cells with inflammatory and suppressive properties, also consistent with functional characteristics as regulatory DC. When a Transwell membrane was used to prevent hematopoietic cell contact with stroma, only cDC-like cells and not L-DC were produced, and cell production was dependent on M-CSF production by stroma. Conclusion: Co-cultures of hematopoietic progenitors over splenic stroma produce two distinct subsets of dendritic-like cells. These are here distinguished phenotypically and through gene expression differences. While both resemble DC, there are functionally distinct. L-DC activate CD8+ but not CD4+ T cells, while the cDC-like population induce regulatory T cells, so reflecting regulatory DC. The latter can be enriched through Transwell co-cultures with cell production dependent on M-CSF. Keywords: Hematopoiesis, Dendritic cell, Regulatory dendritic cells, Regulatory T cellsThis work was supported by project grant #585443 to HO from the National Health and Medical Research Council of Australia. SP was supported by a graduate scholarship from the Royal Thai Government. PP was supported by an Australian National University Graduate Scholarship

    A Guide to Global Population Projections

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    Interdisciplinary studies that draw on long-term, global population projections often make limited use of projection results, due at least in part to the historically opaque nature of the projection process. We present a guide to such projections aimed at researchers and educators who would benefit from putting them to greater use. Drawing on new practices and new thinking on uncertainty, methodology, and the likely future courses of fertility and life expectancy, we discuss who makes projections and how, and the key assumptions upon which they are based. We also compare methodology and recent results from prominent institutions and provide a guide to other sources of demographic information, pointers to projection results, and an entry point to key literature in the field.forecasting, population projections, projection methodology, uncertainty

    The solubility and oxidation state of nickel in silicate melt at low oxygen fugacities: Results using a mechanically assisted equilibration technique

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    The solubility of Ni in a silicate melt has been measured using a new, mechanically assisted equilibration technique over a wide range of controlled ƒO2 values. The melt composition corresponds to the 1 atm eutectic in the system CaAl2Si2O8-CaMgSi2O6 + 10 wt% CaO. The experiments were performed at 1300°C and over an ƒO2 range of 10−8.5 to 10−13.75, and over a temperature range of 1270 to 1390°C at a constant gas mixing ratio ( ). The experiment consists of a sample of melt contained within a crucible of Ni metal and held in a 1 atm gas mixing furnace. A Ni spindle is entered into the sample from above and continuously rotated at a constant angular velocity using a viscometer head. The stirring of the sample serves to accelerate the approach to equilibrium between the liquid sample and the metal crucible (and spindle). This arrangement allows relatively rapid equilibration of Ni content following changes to higher or lower ƒO2 values. Samples of the melt may be taken at any time for analysis and thus the equilibrium solubility of Ni in the silicate melt may be determined from unambiguous experimental reversals. The Ni contents of samples, analysed both by INAA and by ICP-AES, range from 25 to 5300 ppm. The data presented in this paper indicate that the oxidation state of Ni in the investigated melt is Ni2+ over the entire range of ƒO2 investigated. This conclusion contrasts with recent reports in the literature of an inflection in the ƒO2 dependence of Ni solubility, which has been interpreted as solution of neutral Ni at low ƒO2 (Morse et al., 1991; Colson, 1992; Ehlers et al., 1992). We also present data for the temperature dependence of Ni solubility in the investigated melt. The solubility decreases with increasing temperature at constant ƒO2. The present results are in good agreement with the metal-loop-equilibration experiments reported by Holzheid et al. (1994)

    Defining the content and delivery of an intervention to Change AdhereNce to treatment in BonchiEctasis (CAN-BE): a qualitative approach incorporating the Theoretical Domains Framework, behavioural change techniques and stakeholder expert panels

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    BACKGROUND: Low patient adherence to treatment is associated with poorer health outcomes in bronchiectasis. We sought to use the Theoretical Domains Framework (TDF) (a framework derived from 33 psychological theories) and behavioural change techniques (BCTs) to define the content of an intervention to change patients' adherence in bronchiectasis (Stage 1 and 2) and stakeholder expert panels to define its delivery (Stage 3). METHODS: We conducted semi-structured interviews with patients with bronchiectasis about barriers and motivators to adherence to treatment and focus groups or interviews with bronchiectasis healthcare professionals (HCPs) about their ability to change patients' adherence to treatment. We coded these data to the 12 domain TDF to identify relevant domains for patients and HCPs (Stage 1). Three researchers independently mapped relevant domains for patients and HCPs to a list of 35 BCTs to identify two lists (patient and HCP) of potential BCTs for inclusion (Stage 2). We presented these lists to three expert panels (two with patients and one with HCPs/academics from across the UK). We asked panels who the intervention should target, who should deliver it, at what intensity, in what format and setting, and using which outcome measures (Stage 3). RESULTS: Eight TDF domains were perceived to influence patients' and HCPs' behaviours: Knowledge, Skills, Beliefs about capability, Beliefs about consequences, Motivation, Social influences, Behavioural regulation and Nature of behaviours (Stage 1). Twelve BCTs common to patients and HCPs were included in the intervention: Monitoring, Self-monitoring, Feedback, Action planning, Problem solving, Persuasive communication, Goal/target specified:behaviour/outcome, Information regarding behaviour/outcome, Role play, Social support and Cognitive restructuring (Stage 2). Participants thought that an individualised combination of these BCTs should be delivered to all patients, by a member of staff, over several one-to-one and/or group visits in secondary care. Efficacy should be measured using pulmonary exacerbations, hospital admissions and quality of life (Stage 3). CONCLUSIONS: Twelve BCTs form the intervention content. An individualised selection from these 12 BCTs will be delivered to all patients over several face-to-face visits in secondary care. Future research should focus on developing physical materials to aid delivery of the intervention prior to feasibility and pilot testing. If effective, this intervention may improve adherence and health outcomes for those with bronchiectasis in the future

    Antigen presenting capacity of murine splenic myeloid cells

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    BACKGROUND: The spleen is an important site for hematopoiesis. It supports development of myeloid cells from bone marrow-derived precursors entering from blood. Myeloid subsets in spleen are not well characterised although dendritic cell (DC) subsets are clearly defined in terms of phenotype, development and functional role. Recently a novel dendritic-like cell type in spleen named ‘L-DC’ was distinguished from other known dendritic and myeloid cells by its distinct phenotype and developmental origin. That study also redefined splenic eosinophils as well as resident and inflammatory monocytes in spleen. RESULTS: L-DC are shown to be distinct from known splenic macrophages and monocyte subsets. Using a new flow cytometric procedure, it has been possible to identify and isolate L-DC in order to assess their functional competence and ability to activate T cells both in vivo and in vitro. L-DC are readily accessible to antigen given intravenously through receptor-mediated endocytosis. They are also capable of CD8(+) T cell activation through antigen cross presentation, with subsequent induction of cytotoxic effector T cells. L-DC are MHCII(−) cells and unable to activate CD4(+) T cells, a property which clearly distinguishes them from conventional DC. The myeloid subsets of resident monocytes, inflammatory monocytes, neutrophils and eosinophils, were found to have varying capacities to take up antigen, but were uniformly unable to activate either CD4(+) T cells or CD8(+) T cells. CONCLUSION: The results presented here demonstrate that L-DC in spleen are distinct from other myeloid cells in that they can process antigen for CD8(+) T cell activation and induction of cytotoxic effector function, while both L-DC and myeloid subsets remain unable to activate CD4(+) T cells. The L-DC subset in spleen is therefore distinct as an antigen presenting cell
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