796 research outputs found

    Formalization of gene regulation knowledge using ontologies and gene ontology causal activity models

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    Gene regulation computational research requires handling and integrating large amounts of heterogeneous data. The Gene Ontology has demonstrated that ontologies play a fundamental role in biological data interoperability and integration. Ontologies help to express data and knowledge in a machine processable way, which enables complex querying and advanced exploitation of distributed data. Contributing to improve data interoperability in gene regulation is a major objective of the GREEKC Consortium, which aims to develop a standardized gene regulation knowledge commons. GREEKC proposes the use of ontologies and semantic tools for developing interoperable gene regulation knowledge models, which should support data annotation. In this work, we study how such knowledge models can be generated from cartoons of gene regulation scenarios. The proposed method consists of generating descriptions in natural language of the cartoons; extracting the entities from the texts; finding those entities in existing ontologies to reuse as much content as possible, especially from well known and maintained ontologies such as the Gene Ontology, the Sequence Ontology, the Relations Ontology and ChEBI; and implementation of the knowledge models. The models have been implemented using Protégé, a general ontology editor, and Noctua, the tool developed by the Gene Ontology Consortium for the development of causal activity models to capture more comprehensive annotations of genes and link their activities in a causal framework for Gene Ontology Annotations. We applied the method to two gene regulation scenarios and illustrate how to apply the models generated to support the annotation of data from research articles

    FAK acts as a suppressor of RTK-MAP kinase signalling in Drosophila melanogaster epithelia and human cancer cells

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    Receptor Tyrosine Kinases (RTKs) and Focal Adhesion Kinase (FAK) regulate multiple signalling pathways, including mitogen-activated protein (MAP) kinase pathway. FAK interacts with several RTKs but little is known about how FAK regulates their downstream signalling. Here we investigated how FAK regulates signalling resulting from the overexpression of the RTKs RET and EGFR. FAK suppressed RTKs signalling in Drosophila melanogaster epithelia by impairing MAPK pathway. This regulation was also observed in MDA-MB-231 human breast cancer cells, suggesting it is a conserved phenomenon in humans. Mechanistically, FAK reduced receptor recycling into the plasma membrane, which resulted in lower MAPK activation. Conversely, increasing the membrane pool of the receptor increased MAPK pathway signalling. FAK is widely considered as a therapeutic target in cancer biology; however, it also has tumour suppressor properties in some contexts. Therefore, the FAK-mediated negative regulation of RTK/MAPK signalling described here may have potential implications in the designing of therapy strategies for RTK-driven tumours

    Scaling up integration: development and results of a participatory assessment of HIV/TB services, South Africa

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    <p>Abstract</p> <p>Background</p> <p>In South Africa the need to integrate HIV, TB and STI programmes has been recognised at a policy and organisation level; the challenge is now one of translating policies into relevant actions and monitoring implementation to ensure that the anticipated benefits of integration are achieved. In this research, set in public primary care services in Cape Town, South Africa, we set out to determine how middle level managers could be empowered to monitor the implementation of an effective, integrated HIV/TB/STI service.</p> <p>Methods</p> <p>A team of managers and researchers designed an evaluation tool to measure implementation of key components of an integrated HIV/TB/STI package with a focus on integration. They used a comprehensive health systems framework based on conditions for programme effectiveness and then identified and collected tracer indicators. The tool was extensively piloted in two rounds involving 49 clinics in 2003 and 2004 to identify data necessary for effective facility-level management. A subsequent evaluation of 16 clinics (2 per health sub district, 12% of all public primary care facilities) was done in February 2006.</p> <p>Results</p> <p>16 clinics were reviewed and 635 records sampled. Client access to HIV/TB/STI programmes was limited in that 50% of facilities routinely deferred clients. Whilst the physical infrastructure and staff were available, there was problem with capacity in that there was insufficient staff training (for example, only 40% of clinical staff trained in HIV care). Weaknesses were identified in quality of care (for example, only 57% of HIV clients were staged in accordance with protocols) and continuity of care (for example, only 24% of VCT clients diagnosed with HIV were followed up for medical assessment). Facility and programme managers felt that the evaluation tool generated information that was useful to manage the programmes at facility and district level. On the basis of the results facility managers drew up action plans to address three areas of weakness within their own facility.</p> <p>Conclusions</p> <p>This use of the tool which is designed to empower programme and facility managers demonstrates how engaging middle managers is crucial in translating policies into relevant actions.</p

    Prior outpatient antibiotic use as predictor for microbial aetiology of community-acquired pneumonia: hospital-based study

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    Objective: The causative micro-organism in community-acquired pneumonia (CAP) is often difficult to predict. Different studies have examined chronic morbidity and clinical symptoms as predictors for microbial aetiology of pneumonia. The aim of our study was to assess whether prior outpatient antimicrobial treatment is predictive for determining the microbial aetiology of CAP. Methods: This was a hospital-based prospective observational study including all patients admitted with CAP between 1 October 2004 and 1 August 2006. Microbial investigations included sputum, blood culture, sputum PCR, antigen testing and serology. Exposure to antimicrobial drugs prior to hospital admission was ascertained through community pharmacy dispensing records. Multivariate logistic regression analysis was conducted to assess whether prior outpatient antimicrobial treatment is a predictor of microbial aetiology. Patient demographics, co-morbidities and pneumonia severity were considered to be other potential predictors. Results: Overall, 201 patients were included in the study. The microbial aetiology was determined in 64% of the patients. The five most prevalent pathogens were Streptococcus pneumoniae, Heamophilus influenzae, Legionella spp., Mycoplasma pneumoniae and Influenza virus A+B. Forty-seven of the patients (23%) had received initial antimicrobial treatment as outpatients. Multivariate analyses revealed that initial outpatient beta-lactam treatment was associated with a threefold increased chance of finding atypical pathogens and a threefold decreased probability of pneumococcal infection; the corresponding odds ratios were 3.51 (95% CI 1.25-9.99) and 0.30 (95% CI 0.10-0.90), respectively. Patients who received macrolides prior to hospitalisation had an increased probability of viral pneumonia. Conclusion: Prior outpatient antimicrobial therapy has a predictive value in the diagnostic workup aimed at identifying the causative pathogen and planning corresponding antimicrobial treatment in patients hospitalised for pneumonia

    Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

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    Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

    Identifying quantitative operation principles in metabolic pathways: a systematic method for searching feasible enzyme activity patterns leading to cellular adaptive responses

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    <p>Abstract</p> <p>Background</p> <p>Optimization methods allow designing changes in a system so that specific goals are attained. These techniques are fundamental for metabolic engineering. However, they are not directly applicable for investigating the evolution of metabolic adaptation to environmental changes. Although biological systems have evolved by natural selection and result in well-adapted systems, we can hardly expect that actual metabolic processes are at the theoretical optimum that could result from an optimization analysis. More likely, natural systems are to be found in a feasible region compatible with global physiological requirements.</p> <p>Results</p> <p>We first present a new method for globally optimizing nonlinear models of metabolic pathways that are based on the Generalized Mass Action (GMA) representation. The optimization task is posed as a nonconvex nonlinear programming (NLP) problem that is solved by an outer-approximation algorithm. This method relies on solving iteratively reduced NLP slave subproblems and mixed-integer linear programming (MILP) master problems that provide valid upper and lower bounds, respectively, on the global solution to the original NLP. The capabilities of this method are illustrated through its application to the anaerobic fermentation pathway in <it>Saccharomyces cerevisiae</it>. We next introduce a method to identify the feasibility parametric regions that allow a system to meet a set of physiological constraints that can be represented in mathematical terms through algebraic equations. This technique is based on applying the outer-approximation based algorithm iteratively over a reduced search space in order to identify regions that contain feasible solutions to the problem and discard others in which no feasible solution exists. As an example, we characterize the feasible enzyme activity changes that are compatible with an appropriate adaptive response of yeast <it>Saccharomyces cerevisiae </it>to heat shock</p> <p>Conclusion</p> <p>Our results show the utility of the suggested approach for investigating the evolution of adaptive responses to environmental changes. The proposed method can be used in other important applications such as the evaluation of parameter changes that are compatible with health and disease states.</p

    Health Alliance for Prudent Prescribing, Yield and Use of Antimicrobial Drugs in the Treatment of Respiratory Tract Infections (HAPPY AUDIT)

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    <p>Abstract</p> <p>Background</p> <p>Excessive and inappropriate use of antibiotics is considered to be the most important reason for development of bacterial resistance to antibiotics. As antibiotic resistance may spread across borders, high prevalence countries may serve as a source of bacterial resistance for countries with a low prevalence. Therefore, bacterial resistance is an important issue with a potential serious impact on all countries.</p> <p>The majority of respiratory tract infections (RTIs) are treated in general practice. Most infections are caused by virus and antibiotics are therefore unlikely to have any clinical benefit. Several intervention initiatives have been taken to reduce the inappropriate use of antibiotics in primary health care, but the effectiveness of these interventions is only modest. Only few studies have been designed to determine the effectiveness of multifaceted strategies in countries with different practice setting. The aim of this study is to evaluate the impact of a multifaceted intervention targeting general practitioners (GPs) and patients in six countries with different prevalence of antibiotic resistance: Two Nordic countries (Denmark and Sweden), two Baltic Countries (Lithuania and Kaliningrad-Russia) and two Hispano-American countries (Spain and Argentina).</p> <p>Methods/Design</p> <p>HAPPY AUDIT was initiated in 2008 and the project is still ongoing. The project includes 15 partners from 9 countries. GPs participating in HAPPY AUDIT will be audited by the Audit Project Odense (APO) method. The APO method will be used at a multinational level involving GPs from six countries with different cultural background and different organisation of primary health care. Research on the effect of the intervention will be performed by analysing audit registrations carried out before and after the intervention. The intervention includes training courses on management of RTIs, dissemination of clinical guidelines with recommendations for diagnosis and treatment, posters for the waiting room, brochures to patients and implementation of point of care tests (Strep A and CRP) to be used in the GPs'surgeries.</p> <p>To ensure public awareness of the risk of resistant bacteria, media campaigns targeting both professionals and the public will be developed and the results will be published and widely disseminated at a Working Conference hosted by the World Association of Family Doctors (WONCA-Europe) at the end of the project period.</p> <p>Discussion</p> <p>HAPPY AUDIT is an EU-financed project with the aim of contributing to the battle against antibiotic resistance through quality improvement of GPs' diagnosis and treatment of RTIs through development of intervention programmes targeting GPs, parents of young children and healthy adults. It is hypothesized that the use of multifaceted strategies combining active intervention by GPs will be effective in reducing prescribing of unnecessary antibiotics for RTIs and improving the use of appropriate antibiotics in suspected bacterial infections.</p

    Bone mineral density and body composition in postmenopausal women with psoriasis and psoriatic arthritis

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    Introduction: the aim of the present study was to compare bone mineral density (BMD) and body composition (BC) measurements as well as identify risk factors for low BMD and osteoporotic fractures in postmenopausal women with psoriasis (Ps) and psoriatic arthritis (PsA).Methods: A cross-sectional study was carried out in 45 PsA women, 52 Ps women and 98 healthy female controls (HC). Clinical risk factors for low bone density and osteoporotic fracture were evaluated by a specific questionnaire. An X-ray absorptiometry (DXA) at the lumbar spine, total femur and total body was performed on all patients. Skin and joint outcomes were measured by specific tools (PASI, HAQ and DAS28). Morphometric vertebral fractures were evaluated by lumbar and thoracic spine X-ray, according to Genant's method.Results: There were no significant differences in age, body mass index (BMI), total lean mass and bone mineral density among the groups. However, the PsA group had a significantly higher body fat percentage (BF%) than the Ps and HC groups. Osteoporotic fractures were more frequently observed in PsA and Ps groups than in the HC group (P = 0.01). Recurrent falls and a longer duration of disease increased the risk of fracture (odds ratio (OR) = 18.3 and 1.08, respectively) in the PsA group (P = 0.02). Disability was the main factor related to osteoporotic fracture in the Ps group (odds ratio (OR) = 11.1) (P = 0.02).Conclusions: Ps and PsA patients did not present lower BMD. However, they had a higher prevalence of osteoporotic fractures and higher risk of metabolic syndrome. Patients with a longer duration of disease, disability and recurrent falls need preventive measures.Rheumatology Division at UNIFESP/EPMUniversidade Federal de SĂŁo Paulo, UNIFESP Paulista Sch Med, Div Rheumatol, EPM, BR-04023900 SĂŁo Paulo, BrazilUniversidade Federal de SĂŁo Paulo, UNIFESP Paulista Sch Med, Div Rheumatol, EPM, BR-04023900 SĂŁo Paulo, BrazilWeb of Scienc
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