494 research outputs found

    Superoxide dismutase downregulation in osteoarthritis progression and end-stage disease

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    Oxidative stress is proposed as an important factor in osteoarthritis (OA). To investigate the expression of the three superoxide dismutase (SOD) antioxidant enzymes in OA. SOD expression was determined by real-time PCR and immunohistochemistry using human femoral head cartilage. SOD2 expression in Dunkin–Hartley guinea pig knee articular cartilage was determined by immunohistochemistry. The DNA methylation status of the SOD2 promoter was determined using bisulphite sequencing. RNA interference was used to determine the consequence of SOD2 depletion on the levels of reactive oxygen species (ROS) using MitoSOX and collagenases, matrix metalloproteinase 1 (MMP-1) and MMP-13, gene expression. All three SOD were abundantly expressed in human cartilage but were markedly downregulated in end-stage OA cartilage, especially SOD2. In the Dunkin–Hartley guinea pig spontaneous OA model, SOD2 expression was decreased in the medial tibial condyle cartilage before, and after, the development of OA-like lesions. The SOD2 promoter had significant DNA methylation alterations in OA cartilage. Depletion of SOD2 in chondrocytes increased ROS but decreased collagenase expression. This is the first comprehensive expression profile of all SOD genes in cartilage and, importantly, using an animal model, it has been shown that a reduction in SOD2 is associated with the earliest stages of OA. A decrease in SOD2 was found to be associated with an increase in ROS but a reduction of collagenase gene expression, demonstrating the complexities of ROS function

    Perceived health benefits and willingness to pay for parks by park users: quantitative and qualitative research

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    Whilst a growing body of evidence demonstrates people derive a range of health and wellbeing benefits from visiting parks, only a limited number of attempts have been made to provide a complementary economic assessment of parks. The aim of this exploratory study was to directly estimate the perceived health and wellbeing benefits attained from parks and the economic value assigned to parks by park users in Victoria, Australia. The research employed a mixed methods approach (survey and interviews) to collect primary data from a selection of 140 park users: 100 from two metropolitan parks in Melbourne and 40 from a park on the urban fringe of Melbourne, Victoria. Our findings suggest that park users derive a range of perceived physical, mental/spiritual, and social health benefits, but park use was predominantly associated with physical health benefits. Overall, our exploratory study findings suggest that park users are willing to pay for parks, as they highly value them as places for exercising, socialising, and relaxing. Importantly, most people would miss parks if they did not exist. The findings aim to provide park managers, public health advocates, and urban policy makers with evidence about the perceived health and wellbeing benefits of park usage and the economic value park visitors place on parks

    832 Unravelling human melanoma heterogeneity by 6-color multiplex immunofluorescence to overcome recurrence and resistance to therapy

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    Background Inter- and intralesional tumor heterogeneity is commonly seen in metastatic melanoma, likely playing a major role in resistance to therapy, immunotherapy included. This research project aims to identify by 6-color multiplex immunofluorescence melanoma cell subpopulations, to reveal those that are insufficiently targeted by current immunotherapies. Methods In silico analysis of single cell RNAseq data available from the literature for melanoma were performed and matched with a list of known cancer antigens. Genes discriminating between different subpopulations of melanoma cells were selected and included for multiplex immunofluorescence experiments. FFPE sections from pre- and post-immunotherapy (DC vaccination or ipilimumab) treated melanoma patients were stained by multiplex immunofluorescence for AXL, MITF, PRAME, melanoma lineage (comprising Melan-A, gp100 and tyrosinase), CD45 and CD8 expression. Results Single cell-based analysis of RNAseq data revealed two sets of genes discriminating between different subpopulations of melanoma cells and covering most melanoma cells. Set 1 was shown to be AXL high/MITF low and expressed PRAME, whereas set 2 was shown to be AXL low/MITF high and expressed melanoma lineage markers. The 6-color multiplex immunofluorescence panel could discriminate different melanoma subpopulations, thereby giving information on melanoma heterogeneity. Image analyses of melanoma phenotypes and immune infiltrates is still ongoing. These analyses also include the topographical location of different melanoma cell subpopulations with respect to immune cells, and their changes after immunotherapy. Conclusions Melanoma heterogeneity pre- and post-immunotherapy can be analyzed by 6-color multiplex immunofluorescence

    The anxiety and ethanol intake controlling GAL5.1 enhancer is epigenetically modulated by, and controls preference for, high-fat diet

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    Excess maternal fat intake and obesity increase offspring susceptibility to conditions such as chronic anxiety and substance abuse. We hypothesised that environmentally modulated DNA methylation changes (5mC/5hmC) in regulatory regions of the genome that modulate mood and consumptive behaviours could contribute to susceptibility to these conditions. We explored the effects of environmental factors on 5mC/5hmC levels within the GAL5.1 enhancer that controls anxiety-related behaviours and alcohol intake. We first observed that 5mC/5hmC levels within the GAL5.1 enhancer differed significantly in different parts of the brain. Moreover, we noted that early life stress had no significant effect of 5mC/5hmC levels within GAL5.1. In contrast, we identified that allowing access of pregnant mothers to high-fat diet (> 60% calories from fat) had a significant effect on 5mC/5hmC levels within GAL5.1 in hypothalamus and amygdala of resulting male offspring. Cell transfection-based studies using GAL5.1 reporter plasmids showed that 5mC has a significant repressive effect on GAL5.1 activity and its response to known stimuli, such as EGR1 transcription factor expression and PKC agonism. Intriguingly, CRISPR-driven disruption of GAL5.1 from the mouse genome, although having negligible effects on metabolism or general appetite, significantly decreased intake of high-fat diet suggesting that GAL5.1, in addition to being epigenetically modulated by high-fat diet, also actively contributes to the consumption of high-fat diet suggesting its involvement in an environmentally influenced regulatory loop. Furthermore, considering that GAL5.1 also controls alcohol preference and anxiety these studies may provide a first glimpse into an epigenetically controlled mechanism that links maternal high-fat diet with transgenerational susceptibility to alcohol abuse and anxiety

    STROGAR – STrengthening the Reporting Of Genetic Association studies in Radiogenomics

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    AbstractDespite publication of numerous radiogenomics studies to date, positive single nucleotide polymorphism (SNP) associations have rarely been reproduced in independent validation studies. A major reason for these inconsistencies is a high number of false positive findings because no adjustments were made for multiple comparisons. It is also possible that some validation studies were false negatives due to methodological shortcomings or a failure to reproduce relevant details of the original study. Transparent reporting is needed to ensure these flaws do not hamper progress in radiogenomics. In response to the need for improving the quality of research in the area, the Radiogenomics Consortium produced an 18-item checklist for reporting radiogenomics studies. It is recognised that not all studies will have recorded all of the information included in the checklist. However, authors should report on all checklist items and acknowledge any missing information. Use of STROGAR guidelines will advance the field of radiogenomics by increasing the transparency and completeness of reporting

    Inhibitory control, exploration behaviour and manipulated ecological context are associated with foraging flexibility in the great tit

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    Funder: FP7 Ideas: European Research Council; Id: http://dx.doi.org/10.13039/100011199; Grant(s): FP7/2007‐2013Abstract: Organisms are constantly under selection to respond effectively to diverse, sometimes rapid, changes in their environment, but not all individuals are equally plastic in their behaviour. Although cognitive processes and personality are expected to influence individual behavioural plasticity, the effects reported are highly inconsistent, which we hypothesise is because ecological context is usually not considered. We explored how one type of behavioural plasticity, foraging flexibility, was associated with inhibitory control (assayed using a detour‐reaching task) and exploration behaviour in a novel environment (a trait closely linked to the fast–slow personality axis). We investigated how these effects varied across two experimentally manipulated ecological contexts—food value and predation risk. In the first phase of the experiment, we trained great tits Parus major to retrieve high value (preferred) food that was hidden in sand so that this became the familiar food source. In the second phase, we offered them the same familiar hidden food at the same time as a new alternative option that was visible on the surface, which was either high or low value, and under either high or low perceived predation risk. Foraging flexibility was defined as the proportion of choices made during 4‐min trials that were for the new alternative food source. Our assays captured consistent differences among individuals in foraging flexibility. Inhibitory control was associated with foraging flexibility—birds with high inhibitory control were more flexible when the alternative food was of high value, suggesting they inhibited the urge to select the familiar food and instead selected the new food option. Exploration behaviour also predicted flexibility—fast explorers were more flexible, supporting the information‐gathering hypothesis. This tendency was especially strong under high predation risk, suggesting risk aversion also influenced the observed flexibility because fast explorers are risk prone and the new unfamiliar food was perceived to be the risky option. Thus, both behaviours predicted flexibility, and these links were at least partly dependent on ecological conditions. Our results demonstrate that an executive cognitive function (inhibitory control) and a behavioural assay of a well‐known personality axis are both associated with individual variation in the plasticity of a key functional behaviour. That their effects on foraging flexibility were primarily observed as interactions with food value or predation risk treatments also suggest that the population‐level consequences of some behavioural mechanisms may only be revealed across key ecological conditions

    Protocol for the process evaluation of a complex, statewide intervention to reduce salt intake in Victoria, Australia

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    Systematic reviews of trials consistently demonstrate that reducing salt intake lowers blood pressure. However, there is limited evidence on how interventions function in the real world to achieve sustained population-wide salt reduction. Process evaluations are crucial for understanding how and why an intervention resulted in its observed effect in that setting, particularly for complex interventions. This project presents the detailed protocol for a process evaluation of a statewide strategy to lower salt intake in Victoria, Australia. We describe the pragmatic methods used to collect and analyse data on six process evaluation dimensions: reach, dose or adoption, fidelity, effectiveness, context and cost, informed by Linnan and Steckler’s framework and RE-AIM. Data collection methods include routinely collected administrative data; surveys of processed foods, the population, food industry and organizations; targeted campaign evaluation and semi-structured interviews. Quantitative and qualitative data will be triangulated to provide validation or context for one another. This process evaluation will contribute new knowledge about what components of the intervention are important to salt reduction strategies and how the interventions cause reduced salt intake, to inform the transferability of the program to other Australian states and territories. This protocol can be adapted for other population-based, complex, disease prevention interventions

    Inhibitory control performance is repeatable over time and across contexts in a wild bird population

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    Inhibitory control is one of several cognitive mechanisms required for self-regulation, decision making and attention towards tasks. Inhibitory control is expected to influence behavioural plasticity in animals, for example in the context of foraging, social interaction or responses to sudden changes in the environment. One widely used inhibitory control assay is the ‘detour task’ where subjects must avoid impulsively touching transparent barriers positioned in front of food, and instead access the food by an alternative but known route. However, because the detour task has been reported to measure factors unrelated to inhibitory control, including motivation, previous experience and persistence, the task may be unreliable for making cross-species comparisons, estimating individual differences and linking performance with socioecological traits. To address these concerns, we designed a variant of the detour task for wild great tits, Parus major, and deployed it at the nesting site across two spring seasons. We compared task performance of the same individuals in the wild across 2 years, and with their performance in captivity when tested using the classical cylinder detour task during the nonbreeding season. Potential confounds of motivation, previous experience, body size, sex, age and personality did not significantly predict performance, and temporal and contextual repeatability were low but significant. These results support the hypothesis that our assays captured intrinsic differences in inhibitory control. Instead of dismissing detour tasks and ‘throwing the baby out with the bathwater’, we suggest confounds are likely system and experimental-design specific, and that assays for this potentially fundamental but largely overlooked source of behavioural plasticity in animal populations, should be validated and refined for each study system
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