35 research outputs found

    Targeting a custom-engineered flavonoid to the mitochondria protects against acute oxidative stress

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    Oxidative stress is caused when there are more reactive oxygen species (ROS), than antioxidants to scavenge them, resulting in damage to cellular components. It has been implicated as a major player at multiple points in the disease process of Parkinson’s disease (PD) and many other conditions. For example, evidence suggests oxidative damage to the α-synuclein protein may affect its aggregation propensity. In addition, α-synuclein may increase ROS production. However, how this oxidative stress relates to neurodegeneration is not known. Therefore, there is a need for models of α-synucleinopathies and tools to assess the involvement of oxidative stress in the disease process. In order to model α-synucleinopathies, overexpression of the α-synuclein protein was used. A BacMam viral expression system containing human α-synuclein was generated and used to assess toxicity. α-Synuclein overexpression in undifferentiated or differentiated SH-SY5Y cells failed to show toxicity. However, the stability of α-synuclein protein expression and the cell line used may have influenced in the lack of toxicity. The current work provides important guidance for future experimental design. Flavonoids are found in plants and have antioxidant capability. AO-1-530 is a synthetic compound with a flavonoid head group and a long hydrocarbon tail. It is highly cell permeable and localises to the mitochondria. In order to investigate its protective properties, toxin-induced oxidative stress cell assays were established. AO-1-530, in the low micromolar range, was protective against high doses of tert-butyl hydroperoxide (tBHP), whereas natural antioxidants, such as myricetin and quercetin, showed limited protection or required at least 10-fold higher concentrations to achieve similar protection. The ability of AO-1-530 to directly scavenge radicals was assessed cell-free in solution and in a cell-based assay. In solution the mechanism of action was investigated by electron paramagnetic resonance (EPR) spectroscopy. AO-1-530 had similar scavenging ability to myricetin, but was a slightly stronger scavenger than quercetin. The intracellular scavenging ability was quantified by CellROXÂź Deep Red live imaging. Although the compounds had similar cell-free scavenging abilities, AO-1-530 significantly out-performed both myricetin and quercetin in the intracellular assay, suggesting the mitochondrial localisation is critical to its highly protective properties. AO-1-530 is a powerful, novel tool to study the involvement of oxidative stress in diverse disease models

    Mitigation of harm during a novel behavioural response study involving active sonar and wild cetaceans

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    Some studies of how human activities can affect wild free-ranging animals may be considered to have potential negative outcomes too severe to beethically studied. This creates a societal dilemma involving choices between continuing risky activities with high uncertainty about their potentialeffects on wildlife, often with considerable associated precaution or undertaking focused research to reduce uncertainty, but with some risk of harmfrom either strong response leading to potential stranding or direct physical injury from sound exposure. Recent and ongoing field experimentshave measured the conditions in which wild cetaceans respond to military sonar, and provided insight into the nature of responses. Here mitigationmeasures are reported for one of the first such experiments designed to measure fine-scale behavioural responses to controlled exposures of midfrequency(3–4 kHz) active sonar. The objective was to do so without causing the kinds of physical harm that have been previously observed (e.g.stranding events) and that motivated the study. A critical goal of this experimental study was to identify a response that was safe but that could beused as an indicator of the probability of risk from more extreme or sustained exposure from real military operations. A monitoring and mitigationprotocol was developed using a feedback control procedure for real-time mitigation of potential harm. Experimental protocols were modulatedrelative to indicators of potential risk with the explicit objective of detecting potentially harmful consequences of sound exposure and takingappropriate corrective action. Three categories of mitigation methods were developed and integrated within the experimental protocol incorporatingdesigned, engineered, and operational mitigation measures. Controlled exposure experiments involving free-ranging animals were conducted withoutany evident harm to the experimental subjects, while successfully eliciting behavioural responses that provided meaningful results to informmanagement decisions. This approach demonstrates the importance of careful design of protocols in exposure-response experiments, particularlyin pioneering studies assessing response where both the potential for harm and level of uncertainty may be high.Publisher PDFPeer reviewe

    Classification of animal dive tracks via automatic landmarking, principal components analysis and clustering

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    The BRS study was financially supported by the United States (U.S.) Office of Naval Research (www.onr.navy.mil) Grants N00014‐07‐10988, N00014‐07‐11023, N00014‐08‐10990; the U.S. Strategic Environmental Research and Development Program (www.serdp.org) Grant SI‐1539, the Environmental Readiness Division of the U.S. Navy (http://www.navy.mil/local/n45/), the U.S. Chief of Naval Operations Submarine Warfare Division (Undersea Surveillance), the U.S. National Oceanic and Atmospheric Administration (National Marine Fisheries Service, Office of Science and Technology) (http://www.st.nmfs.noaa.gov/), U.S. National Oceanic and Atmospheric Administration Ocean Acoustics Program (http://www.nmfs.noaa.gov/pr/acoustics/), and the Joint Industry Program on Sound and Marine Life of the International Association of Oil and Gas Producers (www.soundandmarinelife.org).The behaviour of animals and their interactions with the environment can be inferred by tracking their movement. For this reason, biologgers are an important source of ecological data, but analysing the shape of the tracks they record is difficult. In this paper we present a technique for automatically determining landmarks that can be used to analyse the shape of animal tracks. The approach uses a parametric version of the SALSA algorithm to fit regression splines to 1‐dimensional curves in N dimensions (in practice N = 2 or 3). The knots of these splines are used as landmarks in a subsequent Principal Components Analysis, and the dives classified via agglomerative clustering. We demonstrate the efficacy of this algorithm on simulated 2‐dimensional dive data, and apply our method to real 3‐dimensional whale dive data from the Behavioral Response Study (BRS) in the Bahamas. The BRS is a series of experiments to quantify shifts in behavior due to SONAR. Our analysis of 3‐dimensional track data supports an alteration in the dive behavior post‐ensonification.Publisher PDFPeer reviewe

    What is a return to work after stroke?: 12 month work outcomes in a feasibility trial

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    Background: Return to work (RTW) is an outcome in determining the effectiveness of rehabilitation post-stroke. However, stroke survivors (SS) may return to different roles with altered work status. Income, hours, responsibilities and job-satisfaction may be reduced. SS may be dissatisfied if unable to resume apriori work status; alternatively adjusted work status may be viewed positively if perceived as a way of reducing the risk of another stroke. The purpose of this study was to explore what is meant by RTW. Method: Information about the nature of RTW (job type, hours, roles, responsibilities) was extracted from 3, 6 and 12 month follow-up postal questionnaires in 46 SS participants in a feasibility randomised controlled trial investigating effectiveness of a vocational rehabilitation intervention. Results/Findings: Participants took a mean 90 (SD:70, range 7-227) days to RTW. 19/46 reported working at 12 months. In 17 who supplied complete data, 7(41%) reported reduced working hours. Participants incurred a mean wage loss of 44% against pre-stroke earnings. 10/17(59%) participants were in the same job with the same employer and 6(35%) were working in different/modified jobs (1 missing:). 10/17(59%) had work-place adjustments. 18/46 (39%) participants were happy with their work situation. Discussion: Participants experienced marked changes in work status post-stroke, with implications for job-satisfaction, financial security and quality of life. Research into psychological adjustment following altered vocational status in SS is warranted. Conclusion: RTW is a complex outcome and may not translate to a return to pre-stroke vocational status. It is important to consider what constitutes a RTW following stroke

    Implementation of corticosteroids in treating COVID-19 in the ISARIC WHO Clinical Characterisation Protocol UK:prospective observational cohort study

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    BACKGROUND: Dexamethasone was the first intervention proven to reduce mortality in patients with COVID-19 being treated in hospital. We aimed to evaluate the adoption of corticosteroids in the treatment of COVID-19 in the UK after the RECOVERY trial publication on June 16, 2020, and to identify discrepancies in care. METHODS: We did an audit of clinical implementation of corticosteroids in a prospective, observational, cohort study in 237 UK acute care hospitals between March 16, 2020, and April 14, 2021, restricted to patients aged 18 years or older with proven or high likelihood of COVID-19, who received supplementary oxygen. The primary outcome was administration of dexamethasone, prednisolone, hydrocortisone, or methylprednisolone. This study is registered with ISRCTN, ISRCTN66726260. FINDINGS: Between June 17, 2020, and April 14, 2021, 47 795 (75·2%) of 63 525 of patients on supplementary oxygen received corticosteroids, higher among patients requiring critical care than in those who received ward care (11 185 [86·6%] of 12 909 vs 36 415 [72·4%] of 50 278). Patients 50 years or older were significantly less likely to receive corticosteroids than those younger than 50 years (adjusted odds ratio 0·79 [95% CI 0·70–0·89], p=0·0001, for 70–79 years; 0·52 [0·46–0·58], p80 years), independent of patient demographics and illness severity. 84 (54·2%) of 155 pregnant women received corticosteroids. Rates of corticosteroid administration increased from 27·5% in the week before June 16, 2020, to 75–80% in January, 2021. INTERPRETATION: Implementation of corticosteroids into clinical practice in the UK for patients with COVID-19 has been successful, but not universal. Patients older than 70 years, independent of illness severity, chronic neurological disease, and dementia, were less likely to receive corticosteroids than those who were younger, as were pregnant women. This could reflect appropriate clinical decision making, but the possibility of inequitable access to life-saving care should be considered. FUNDING: UK National Institute for Health Research and UK Medical Research Council

    A collaborative approach to exploring the future of Cancer treatment and care in relation to Precision Medicine: A design perspective.

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    The Precision Medicine and the Future of Cancer project was jointly conceived by the Innovation School at Glasgow School of Art and the Institute of Cancer Sciences at the University of Glasgow. Graduating year Product Design students from the Innovation School were presented with a challenge-based project to produce a vision of the future based on current trends that relate to Precision Medicine(PM) and Cancer treatment. This project involved working closely with scientists, clinicians, patients, industry and academic professionals from Glasgow University, staff at Queen Elizabeth University Hospital and Clinical Innovation Zone, staff at Beatson West of Scotland Cancer Centre, Patient Representatives and external design experts from Studio AndThen and GOODD design consultancy. The objective of this project was to investigate, in both analytical and speculative ways, future forms and functions of cancer treatment and care in relation to Precision Medicine, to develop future scenarios and design artefacts, services, and the experiences associated with them. One of the most significant societal shifts currently taking place within the field of PM is the transformation around what it means to be a patient and a professional working within this context. The public’s role is developing beyond once-passive patients into stakeholders valued within the medical industry and healthcare sector for their participation in clinical trials, and contribution towards policy-making and decision-making committees. This new dynamic is changing the traditional patient-doctor relationship and challenging the hegemony of medical practice at an institutional level. The impetus for this shift is relentless technological acceleration and increased scientific research, in particular driven by advances in PM. This project asked students to consider what will happen in a cancer landscape ten years from now, where PM has evolved to the extent that new forms of medical practice, cancer treatment and care transform how we interact with each other, with professionals and the world around us. The brief gave students the opportunity to reflect on the underlying complexities regarding the future of health, technological acceleration, post-capitalism and human agency, to envision a future world context, develop it as an experiential exhibit, and produce the designed products, services and experiences for the people who might live and work within it. The project was divided into two sections: The first was a collaborative stage where groups of students were assigned a specific area of focus from Social, Technological, Economic, Ethical, Educational, Political, Legal, Ecological [STEEEPLE]. These groups focused on researching and exploring their specific lenses and gathering as much information and understanding while working with external experts to further their knowledge. This group stage culminated in an exhibition of the collaborative understanding of what the future could look like in 10 years from now, after exploring the possible consequences of current actions. The second stage saw students explore their individual response to the world that had been defined in the first stage. Each student had their own response to the research by iteratively creating a design outcome that was appropriate to the subject matter. This culminated in each student having created a design product/service/experience relating to the future scenario. A full report (Project Process Journal [PPJ]) is included within the repository of each student which breaks down their process of designing and the outcome they have designed. The project aims to tackle the emerging possibilities where medical professionals and design can collaborate, to create a future where forms of medical practice are more preventative and are more appropriate for an aging population now and into the future. The deposited materials are arranged as follows: Readme files - two readme files relate to stage one and stage two of the project as outlined above. Overview poster - gives a visual overview of the structure and timeline of the project. Data folders - the data folders for stage one of the project are named for the lens through which each group viewed possible futures. The data folders for stage two of the project are named for the individual students who conducted the work

    Identification of a BRCA2-Specific modifier locus at 6p24 related to breast cancer risk

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    Common genetic variants contribute to the observed variation in breast cancer risk for BRCA2 mutation carriers; those known to date have all been found through population-based genome-wide association studies (GWAS). To comprehensively identify breast cancer risk modifying loci for BRCA2 mutation carriers, we conducted a deep replication of an ongoing GWAS discovery study. Using the ranked P-values of the breast cancer associations with the imputed genotype of 1.4 M SNPs, 19,029 SNPs were selected and designed for inclusion on a custom Illumina array that included a total of 211,155 SNPs as part of a multi-consortial project. DNA samples from 3,881 breast cancer affected and 4,330 unaffected BRCA2 mutation carriers from 47 studies belonging to the Consortium of Investigators of Modifiers of BRCA1/2 were genotyped and available for analysis. We replicated previously reported breast cancer susceptibility alleles in these BRCA2 mutation carriers and for several regions (including FGFR2, MAP3K1, CDKN2A/B, and PTHLH) identified SNPs that have stronger evidence of association than those previously published. We also identified a novel susceptibility allele at 6p24 that was inversely associated with risk in BRCA2 mutation carriers (rs9348512; per allele HR = 0.85, 95% CI 0.80-0.90, P = 3.9×10−8). This SNP was not associated with breast cancer risk either in the general population or in BRCA1 mutation carriers. The locus lies within a region containing TFAP2A, which encodes a transcriptional activation protein that interacts with several tumor suppressor genes. This report identifies the first breast cancer risk locus specific to a BRCA2 mutation background. This comprehensive update of novel and previously reported breast cancer susceptibility loci contributes to the establishment of a panel of SNPs that modify breast cancer risk in BRCA2 mutation carriers. This panel may have clinical utility for women with BRCA2 mutations weighing options for medical prevention of breast cancer

    An original phylogenetic approach identified mitochondrial haplogroup T1a1 as inversely associated with breast cancer risk in BRCA2 mutation carriers

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    Introduction: Individuals carrying pathogenic mutations in the BRCA1 and BRCA2 genes have a high lifetime risk of breast cancer. BRCA1 and BRCA2 are involved in DNA double-strand break repair, DNA alterations that can be caused by exposure to reactive oxygen species, a main source of which are mitochondria. Mitochondrial genome variations affect electron transport chain efficiency and reactive oxygen species production. Individuals with different mitochondrial haplogroups differ in their metabolism and sensitivity to oxidative stress. Variability in mitochondrial genetic background can alter reactive oxygen species production, leading to cancer risk. In the present study, we tested the hypothesis that mitochondrial haplogroups modify breast cancer risk in BRCA1/2 mutation carriers. Methods: We genotyped 22,214 (11,421 affected, 10,793 unaffected) mutation carriers belonging to the Consortium of Investigators of Modifiers of BRCA1/2 for 129 mitochondrial polymorphisms using the iCOGS array. Haplogroup inference and association detection were performed using a phylogenetic approach. ALTree was applied to explore the reference mitochondrial evolutionary tree and detect subclades enriched in affected or unaffected individuals. Results: We discovered that subclade T1a1 was depleted in affected BRCA2 mutation carriers compared with the rest of clade T (hazard ratio (HR) = 0.55; 95% confidence interval (CI), 0.34 to 0.88; P = 0.01). Compared with the most frequent haplogroup in the general population (that is, H and T clades), the T1a1 haplogroup has a HR of 0.62 (95% CI, 0.40 to 0.95; P = 0.03). We also identified three potential susceptibility loci, including G13708A/rs28359178, which has demonstrated an inverse association with familial breast cancer risk. Conclusions: This study illustrates how original approaches such as the phylogeny-based method we used can empower classical molecular epidemiological studies aimed at identifying association or risk modification effects.Peer reviewe

    Genome-Wide Association Study in BRCA1 Mutation Carriers Identifies Novel Loci Associated with Breast and Ovarian Cancer Risk

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    BRCA1-associated breast and ovarian cancer risks can be modified by common genetic variants. To identify further cancer risk-modifying loci, we performed a multi-stage GWAS of 11,705 BRCA1 carriers (of whom 5,920 were diagnosed with breast and 1,839 were diagnosed with ovarian cancer), with a further replication in an additional sample of 2,646 BRCA1 carriers. We identified a novel breast cancer risk modifier locus at 1q32 for BRCA1 carriers (rs2290854, P = 2.7×10-8, HR = 1.14, 95% CI: 1.09-1.20). In addition, we identified two novel ovarian cancer risk modifier loci: 17q21.31 (rs17631303, P = 1.4×10-8, HR = 1.27, 95% CI: 1.17-1.38) and 4q32.3 (rs4691139, P = 3.4×10-8, HR = 1.20, 95% CI: 1.17-1.38). The 4q32.3 locus was not associated with ovarian cancer risk in the general population or BRCA2 carriers, suggesting a BRCA1-specific associat
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