972 resultados para Pro-opimélanocortine


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In the spirit of previous work in the compliance literature (e.g., tax, littering), we investigate whether environmental social norms affect volunteering in environmental organizations. Using two ‘environmental morale’ variables as indirect measures, we analyze the impact of social norms on the incidence of unpaid work in environmental organizations. In addition, we test whether violation of a specific environmental norm initiates a conditional cooperation response. We explore a large individual data set covering 32 countries from both Western and Eastern Europe, and extend the number of countries investigated to test the robustness of the relationship at the macro level. Our results indicate a strong positive relationship between the proxies for environmental social norms and volunteering in environmental organizations. The relationship persists despite our various robustness checks.

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Eleven Pro-Am curators of Australian television history were interviewed about their practice. The data helps us to understand the relationship between professional and Pro-Am approaches to Australian television history. There is no simple binary – the lines are blurred – but there are some differences. Pro-Am curators of Australian television history are not paid for their work and present other motivations for practice – particularly being that ‘weird child’ who was obsessed with gathering information and objects related to television. They have freedom to curate only programs and genres that interest them, and they tend to collect merchandise as much as program texts themselves. And they have less interest in formally cataloguing their material than do professional curators of Australian television history.

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Pro-anorexia Internet sites aim to promote, support and discuss anorexia nervosa. Media coverage has raised concerns that sites may increase the level of eating disorders. This research examines the meaning of participation in a pro-anorexia Internet site and its relationship with disordered eating by using an interpretative phenomenological analysis of fifteen separate message ‘threads’ followed over a six-week period. Four themes were identified: (1) tips and techniques; (2) ‘ana’ v. anorexia nervosa; (3) social support; and (4) need for anorexia. Findings suggest participation was multi-purpose, providing a coping function in relation to weight loss, and the contribution of sites to increased levels of eating disorders is not inevitable.

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The role of inflammatory response after spinal cord injury remains unclear. This thesis was a step forward in studying how promoting the inflammation, by delivery pro-inflammatory growth factors, affects the outcomes of spinal cord injury. A significant functional improvement was observed after treatment and these results suggest an interesting avenue for future clinical treatments and may provide a platform to improve the efficacy of other treatments.

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Background: The insulin-like growth factor (IGF) system is composed of ligands and receptors which regulate cell proliferation, survival, differentiation and migration. Some functions are regulated via intracellular signaling cascades, others by involvement of the extracellular milieu, including binding proteins and other extracellular matrix proteins. However, understanding of their functions and the exact nature of these interactions remains incomplete. Methods: IGF-I was PEGylated at its lysine sites - K27, K65 and K68. Binding of PEG-IGF-I to the IGFBPs was analyzed using BIAcore and its ability to activate the IGF-IR was assessed using IGF-IR phosphorylation assay. Furthermore, functional consequences of PEGylating the lysine residues of IGF-I was investigated using cell viability and cell migration assays. In addition, particular downstream signaling pathways regularly implicated in these mechanisms were also dissected using phospho-AKT and phospho-ERK1/2 assays. Results: In this study, IGF-I specifically PEGylated at lysine 27 (PEG-K27), 65 (PEG-K65) or 68 (PEG-K68) were employed. Receptor phosphorylation was only reduced by 2-fold with PEG-K65 and PEG-K68 over all the time points tested, and as observed in two cell types, 3T3 fibroblasts and MCF-7 breast cancer cells. PEGylation at K27 resulted in a much larger effect, with more than 10-fold lower activation for 3T3 fibroblasts and a ~3 fold reduced IGF-IR activation for MCF-7 breast cancer cells over 15 minutes. In addition, all PEG-IGF-I variants demonstrated a ten-fold reduction in the association rate to IGF binding proteins (IGFBPs). Functionally, all PEG variants completely lost their ability to induce cell migration in the presence of IGFBP-3/vitronectin (VN) complexes as compared to IGF-I; in contrast, cell viability was fully preserved. Further investigations into the downstream signaling pathways revealed that the PI3-K/AKT pathway was preferentially affected upon treatment with the PEG-IGF-I variants compared to the MAPK/ERK pathway. Conclusion: PEGylation of IGF-I has an impact on cell migration but not cell viability. General significance: PEG-IGF-I may differentially modulate IGF-I mediated functions that are dependent on its interaction with its receptor as well as key extracellular proteins such as VN and IGFBPs.

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Rural communities across Australia are increasingly being asked to shoulder the environmental and social impacts of intensive mining and gas projects. Escalating demand for coal seam gas (CSG) is raising significant environmental justice issues for rural communities. Chief amongst environmental concerns are risks of contamination or depletion of vital underground aquifers as well as treatment and disposal of high-saline water close to high quality agricultural soils. Associated infrastructure such as pipelines, electricity lines, gas processing and port facilities can also adversely affect communities and ecosystems great distances from where the gas is originally extracted. Whilst community submission (and appeal) rights do exist, accessing expert independent information is challenging, legal terminology is complex and submission periods are short, leading ultimately to a lack of procedural justice for landholders and their communities. Since August 2012, Queensland University of Technology (QUT) has worked in partnership with not-for-profit legal centre - Queensland’s Environmental Defenders Office (EDO) - to help better educate communities about mining and CSG assessment processes. The project, now entering its third semester, aims to empower communities to access relevant information and actively engage in legal processes on their own behalf. Students involved in the project so far have helped to research chapters of a comprehensive community guide to mining and CSG law as well as organising multidisciplinary community forums and preparing information on land access and compensation rights for landholders. While environmental justice issues still exist without significant law reform, the project has led to greater awareness amongst the community of the laws relating the CSG. At the same time, it has led to a greater understanding by students and academics of real life environmental justice issues currently faced by rural communities.

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Background IL-23 is a member of the IL-6 super-family and plays key roles in cancer. Very little is currently known about the role of IL-23 in non-small cell lung cancer (NSCLC). Methods RT-PCR and chromatin immunopreciptiation (ChIP) were used to examine the levels, epigenetic regulation and effects of various drugs (DNA methyltransferase inhibitors, Histone Deacetylase inhibitors and Gemcitabine) on IL-23 expression in NSCLC cells and macrophages. The effects of recombinant IL-23 protein on cellular proliferation were examined by MTT assay. Statistical analysis consisted of Student's t-test or one way analysis of variance (ANOVA) where groups in the experiment were three or more. Results In a cohort of primary non-small cell lung cancer (NSCLC) tumours, IL-23A expression was significantly elevated in patient tumour samples (p<0.05). IL-23A expression is epigenetically regulated through histone post-translational modifications and DNA CpG methylation. Gemcitabine, a chemotherapy drug indicated for first-line treatment of NSCLC also induced IL-23A expression. Recombinant IL-23 significantly increased cellular proliferation in NSCLC cell lines. Conclusions These results may therefore have important implications for treating NSCLC patients with either epigenetic targeted therapies or Gemcitabine. © 2012 Elsevier Ireland Ltd.

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Objectives Titanium implant surfaces with modified topographies have improved osteogenic properties in vivo. However, the molecular mechanisms remain obscure. This study explored the signaling pathways responsible for the pro-osteogenic properties of micro-roughened (SLA) and chemically/nanostructurally (modSLA) modified titanium surfaces on human alveolar bone-derived osteoprogenitor cells (BCs) in vitro. Materials and methods The activation of stem cell signaling pathways (TGFβ/BMP, Wnt, FGF, Hedgehog, Notch) was investigated following early exposure (24 and 72 h) of BCs to SLA and modSLA surfaces in the absence of osteogenic cell culture supplements. Results Key regulatory genes from the TGFβ/BMP (TGFBR2, BMPR2, BMPR1B, ACVR1B, SMAD1, SMAD5), Wnt (Wnt/β-catenin and Wnt/Ca2+) (FZD1, FZD3, FZD5, LRP5, NFATC1, NFATC2, NFATC4, PYGO2, LEF1) and Notch (NOTCH1, NOTCH2, NOTCH4, PSEN1, PSEN2, PSENEN) pathways were upregulated on the modified surfaces. These findings correlated with a higher expression of osteogenic markers bone sialoprotein (IBSP) and osteocalcin (BGLAP), and bone differentiation factors BMP2, BMP6, and GDF15, as observed on the modified surfaces. Conclusions These findings demonstrate that the activation of the pro-osteogenic cell signaling pathways by modSLA and SLA surfaces leads to enhanced osteogenic differentiation as evidenced after 7 and 14 days culture in osteogenic media and provides a mechanistic insight into the superior osseointegration on the modified surfaces observed in vivo.

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Compromised angiogenesis appears to be a major limitation in various suboptimal bone healing situations. Appropriate mechanical stimuli support blood vessel formation in vivo and improve healing outcomes. However, the mechanisms responsible for this association are unclear. To address this question, the paracrine angiogenic potential of early human fracture haematoma and its responsiveness to mechanical loading, as well as angiogenic growth factors involved, were investigated in vitro. Human haematomas were collected from healthy patients undergoing surgery within 72. h after bone fracture. The haematomas were embedded in a fibrin matrix, and cultured in a bioreactor resembling the in vivo conditions of the early phase of bone healing (20 compression, 1. Hz) over 3. days. Conditioned medium (CM) from the bioreactor was then analyzed. The matrices were also incubated in fresh medium for a further 24. h to evaluate the persistence of the effects. Growth factor (GF) concentrations were measured in the CM by ELISAs. In vitro tube formation assays were conducted on Matrigel with the HMEC-1 cell line, with or without inhibition of vascular endothelial growth factor receptor 2 (VEGFR2). Cell numbers were quantified using an MTS test. In vitro endothelial tube formation was enhanced by CM from haematomas, compared to fibrin controls. The angiogenesis regulators, vascular endothelial growth factor (VEGF) and transforming growth factor β1 (TGF-β1), were released into the haematoma CM, but not angiopoietins 1 or 2 (Ang1, 2), basic fibroblast growth factor (bFGF) or platelet-derived growth factor (PDGF). Mechanical stimulation of haematomas, but not fibrin controls, further increased the induction of tube formation by their CM. The mechanically stimulated haematoma matrices retained their elevated pro-angiogenic capacity for 24. h. The pro-angiogenic effect was cancelled by inhibition of VEGFR2 signalling. VEGF concentrations in CM tended to be elevated by mechanical stimulation; this was significant in haematomas from younger, but not from older patients. Other GFs were not mechanically regulated. In conclusion, the paracrine pro-angiogenic capacity of early human haematomas is enhanced by mechanical stimulation. This effect lasts even after removing the mechanical stimulus and appears to be VEGFR2-dependent.

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This investigation measured the effects of a one year participation in an Australian Philosophical Community of Inquiry program on 280 sixth grade students' reading comprehension, interest in maths, self-esteem, social behaviours, and emotional well-being. A multilevel model for change was used to detect differences in the response variables, between a quasi-experimental group and comparison group. Results showed that, for participants, reading comprehension significantly increased while interest in maths decreased. No differences between the groups were found for pro-social behaviour and emotional well-being. Self esteem, however, declined for participants while nonparticipants' self esteem increased.

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Because of their limited number of senior positions and fewer alternative career paths, small businesses have a more difficult time attracting and retaining skilled information systems (IS) staff and are thus dependent upon external expertise. Small businesses are particularly dependent on outside expertise when first computerizing. Because small businesses suffer from severe financial constraints. it is often difficult to justify the cost of custom software. Hence. for many small businesses, engaging a consultant to help with identifying suitable packaged software and related hardware, is their first critical step toward computerization. This study explores the importance of proactive client involvement when engaging a consultant to assist with computer system selection in small businesses. Client involvement throughout consultant engagement is found to be integral to project success and frequently lacking due to misconceptions of small businesses regarding their role. Small businesses often overestimate the impact of consultant and vendor support in achieving successful computer system selection and implementation. For consultant engagement to be successful, the process must be viewed as being directed toward the achievement of specific organizational results where the client accepts responsibility for direction of the process.

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Equine laminitis, a disease of the lamellar structure of the horse’s hoof, can be incited by numerous factors that include inflammatory and metabolic aetiologies. However, the role of inflammation in hyperinsulinaemic laminitis has not been adequately defined. Tolllike receptor (TLR) activation results in up-regulation of inflammatory pathways and the release of pro-inflammatory cytokines, including interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-�), and may be a pathogenic factor in laminitis. The aim of this study was to determine whether TLR4 expression and subsequent pro-inflammatory cytokine production is increased in lamellae and skeletal muscle during equine hyperinsulinaemia. Standardbred horses were treated with either a prolonged, euglycaemic hyperinsulinaemic clamp (p-EHC) or a prolonged, glucose infusion (p-GI), which induced marked and moderate hyperinsulinaemia, respectively. Age-matched control horses were treated simultaneously with a balanced electrolyte solution. Treated horses developed clinical (p-EHC) or subclinical (p-GI) laminitis, whereas controls did not. Skeletal muscle and lamellar protein extracts were analysed by Western blotting for TLR4, IL-6, TNF-� and suppressor of cytokine signalling 3 (SOCS3) expression. Lamellar protein expression of TLR4 and TNF-�, but not IL-6, was increased by the p-EHC, compared to control horses. A significant positive correlation was found between lamellar TLR4 and SOCS3. Skeletal muscle protein expression of TLR4 signalling parameters did not differ between control and p-EHC-treated horses. Similarly, the p-GI did not result in up-regulation of lamellar protein expression of any parameter. The results suggest that insulin-sensitive tissues may not accurately reflect lamellar pathology during hyperinsulinaemia. While TLR4 is present in the lamellae, its activation appears unlikely to contribute significantly to the developmental pathogenesis of hyperinsulinaemic laminitis. However, inflammation may have a role to play in the later stages (e.g., repair or remodelling) of the disease.

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The ability to activate pro-matrix metalloproteinase (pro-MMP)-2 via membrane type-MMP is a hallmark of human breast cancer cell lines that show increased invasiveness, suggesting that MMP-2 contributes to human breast cancer progression. To investigate this, we have stably transfected pro-MMP-2 into the human breast cancer cell line MDA-MB-231, which lacks MMP-2 expression but does express its cell surface activator, membrane type 1-MMP. Multiple clones were derived and shown to produce pro-MMP-2 and to activate it in response to concanavalin A. In vitro analysis showed that the pro-MMP-2-transfected clones exhibited an increased invasive potential in Boyden chamber and Matrigel outgrowth assays, compared with the parental cells or those transfected with vector only. When inoculated into the mammary fat pad of nude mice, each of the MMP-2-tranfected clones grew faster than each of the vector controls tested. After intracardiac inoculation into nude mice, pro-MMP-2-transfected clones showed a significant increase in the incidence of metastasis to brain, liver, bone, and kidney compared with the vector control clones but not lung. Increased tumor burden was seen in the primary site and in lung metastases, and a trend toward increased burden was seen in bone, however, no change was seen in brain, liver, or kidney. This data supports a role for MMP-2 in breast cancer progression, both in the growth of primary tumors and in their spread to distant organs. MMP-2 may be a useful target for breast cancer therapy when refinement of MMP inhibitors provides for MMP-specific agents.