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Mallinson JE, Wardle SL, O'Leary TJ, Greeves JP, Cegielski J, Bass J, Brook MS, Wilkinson DJ, Smith K, Atherton PJ, Greenhaff PL. Protein dose requirements to maximize skeletal muscle protein synthesis after repeated bouts of resistance exercise in young trained women. Scand J Med Sci Sports 2023; 33:2470-2481. [PMID: 37787091 DOI: 10.1111/sms.14506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 09/11/2023] [Accepted: 09/19/2023] [Indexed: 10/04/2023]
Abstract
Studies examining the effect of protein (PRO) feeding on post resistance exercise (RE) muscle protein synthesis (MPS) have primarily been performed in men, and little evidence is available regarding the quantity of PRO required to maximally stimulate MPS in trained women following repeated bouts of RE. We therefore quantified acute (4 h and 8 h) and extended (24 h) effects of two bouts of resistance exercise, alongside protein-feeding, in women, and the PRO requirement to maximize MPS. Twenty-four RE trained women (26.6 ± 0.7 years, mean ± SEM) performed two bouts of whole-body RE (3 × 8 repetitions/maneuver at 75% 1-repetition maximum) 4 h apart, with post-exercise ingestion of 15 g, 30 g, or 60 g whey PRO (n = 8/group). Saliva, venous blood, and a vastus lateralis muscle biopsy were taken at 0 h, 4 h, 8 h, and 24 h post-exercise. Plasma leucine and branched chain amino acids were quantified using gas chromatography mass spectrometry (GC-MS) after ingestion of D2 O. Fifteen grams PRO did not alter plasma leucine concentration or myofibrillar synthetic rate (MyoFSR). Thirty and sixty grams PRO increased plasma leucine concentration above baseline (105.5 ± 5.3 μM; 120.2 ± 7.4 μM, respectively) at 4 h (151.5 ± 8.2 μM, p < 0.01; 224.8 ± 16.0 μM, p < 0.001, respectively) and 8 h (176.0 ± 7.3 μM, p < 0.001; 281.7 ± 21.6 μM, p < 0.001, respectively). Ingestion of 30 g PRO increased MyoFSR above baseline (0.068 ± 0.005%/h) from 0 to 4 h (0.140 ± 0.021%/h, p < 0.05), 0 to 8 h (0.121 ± 0.012%/h, p < 0.001), and 0 to 24 h (0.099 ± 0.011%/h, p < 0.01). Ingestion of 60 g PRO increased MyoFSR above baseline (0.063 ± 0.003%/h) from 0 to 4 h (0.109 ± 0.011%/h, p < 0.01), 0 to 8 h (0.093 ± 0.008%/h, p < 0.01), and 0 to 24 h (0.086 ± 0.006%/h, p < 0.01). Post-exercise ingestion of 30 g or 60 g PRO, but not 15 g, acutely increased MyoFSR following two consecutive bouts of RE and extended the anabolic window over 24 h. There was no difference between the 30 g and 60 g responses.
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Affiliation(s)
- J E Mallinson
- School of Life Sciences, MRC/Versus Arthritis Centre for Musculoskeletal Ageing Research, University of Nottingham, Nottingham, UK
| | - S L Wardle
- Army Health and Performance Research, Army Headquarters, Andover, UK
- Division of Surgery and Interventional Science, University College London, London, UK
| | - T J O'Leary
- Army Health and Performance Research, Army Headquarters, Andover, UK
- Division of Surgery and Interventional Science, University College London, London, UK
| | - J P Greeves
- Army Health and Performance Research, Army Headquarters, Andover, UK
- Division of Surgery and Interventional Science, University College London, London, UK
- Norwich Medical School, University of East Anglia, Norwich, UK
| | - J Cegielski
- School of Medicine, MRC/Versus Arthritis Centre for Musculoskeletal Ageing Research, University of Nottingham, Nottingham, UK
| | - J Bass
- School of Medicine, MRC/Versus Arthritis Centre for Musculoskeletal Ageing Research, University of Nottingham, Nottingham, UK
| | - M S Brook
- School of Life Sciences, MRC/Versus Arthritis Centre for Musculoskeletal Ageing Research, University of Nottingham, Nottingham, UK
| | - D J Wilkinson
- School of Medicine, MRC/Versus Arthritis Centre for Musculoskeletal Ageing Research, University of Nottingham, Nottingham, UK
| | - K Smith
- School of Medicine, MRC/Versus Arthritis Centre for Musculoskeletal Ageing Research, University of Nottingham, Nottingham, UK
| | - P J Atherton
- School of Medicine, MRC/Versus Arthritis Centre for Musculoskeletal Ageing Research, University of Nottingham, Nottingham, UK
| | - P L Greenhaff
- School of Life Sciences, MRC/Versus Arthritis Centre for Musculoskeletal Ageing Research, University of Nottingham, Nottingham, UK
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Hall HN, Wilkinson DJ, Le Bon M. Oregano essential oil improves piglet health and performance through maternal feeding and is associated with changes in the gut microbiota. Anim Microbiome 2021; 3:2. [PMID: 33499989 PMCID: PMC7934403 DOI: 10.1186/s42523-020-00064-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 11/24/2020] [Indexed: 01/04/2023] Open
Abstract
Background With a growing demand for safe and sustainable alternatives to antimicrobials, functional feed ingredients such as plant essential oils have been evaluated for their potential to improve gut health. Amongst these, oregano essential oil (OEO) with the main active compounds carvacrol and thymol has been reported to have antimicrobial and antioxidative properties resulting in improved intestinal barrier function and growth in pigs and poultry. However, its impact on the gut microbiota still remains unclear. The aim of this study was to examine the effect of an oregano essential oil phytobiotic on sow and piglet performance and faecal microbiota. Results Piglets from OEO supplemented sows were significantly heavier at one week of age and showed a trend for improved average daily weight gain from birth to weaning. Post-weaning, maternally supplemented piglets were numerically heavier at 10 weeks post-weaning and at slaughter with a reduced variability in bodyweight. Health records showed that piglets in the OEO supplemented litters had significantly reduced incidence of therapeutic treatment and reduced mortality. In both sows and piglets, the structure and composition of the faecal microbiota varied considerably over time. Sows supplemented with OEO during lactation showed an increase in the relative abundance of Lactobacillaceae family. In addition, there was an increase in the relative abundance of families known to be important in fibre digestion (Fibrobacteriaceae and Akkermansiaceae). Analysis of piglet microbiota at two weeks and four weeks of age revealed a relative decrease in Enterobacteriaceae while butyrate producers (Lachnospiraceae family) were increased at both timepoints. Conclusion We hypothesise that the effects observed from this study were exerted through modulation of the gut microbial communities in the sow and her offspring through maternal microbial transfer. Understanding the link between the gut microbiota and dietary factors represents a keystone to improving health and performance for sustainable pig production. Reducing antimicrobial usage can help to reduce the risk of antimicrobial resistance (AMR) which is a global focus for animal production.
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Affiliation(s)
- H N Hall
- Anpario plc, Unit 5, Manton Wood, Worksop, S80 2RS, UK.
| | - D J Wilkinson
- Antimicrobial Resistance, Omics and Microbiota research group, Clifton Lane, Nottingham Trent University, Nottingham, NG11 8NS, UK
| | - M Le Bon
- Nottingham Trent University, School of Animal, Rural and Environmental Sciences, Southwell, NG25 0QF, UK
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Keating SM, Waltemath D, König M, Zhang F, Dräger A, Chaouiya C, Bergmann FT, Finney A, Gillespie CS, Helikar T, Hoops S, Malik‐Sheriff RS, Moodie SL, Moraru II, Myers CJ, Naldi A, Olivier BG, Sahle S, Schaff JC, Smith LP, Swat MJ, Thieffry D, Watanabe L, Wilkinson DJ, Blinov ML, Begley K, Faeder JR, Gómez HF, Hamm TM, Inagaki Y, Liebermeister W, Lister AL, Lucio D, Mjolsness E, Proctor CJ, Raman K, Rodriguez N, Shaffer CA, Shapiro BE, Stelling J, Swainston N, Tanimura N, Wagner J, Meier‐Schellersheim M, Sauro HM, Palsson B, Bolouri H, Kitano H, Funahashi A, Hermjakob H, Doyle JC, Hucka M. SBML Level 3: an extensible format for the exchange and reuse of biological models. Mol Syst Biol 2020; 16:e9110. [PMID: 32845085 PMCID: PMC8411907 DOI: 10.15252/msb.20199110] [Citation(s) in RCA: 113] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 06/24/2020] [Accepted: 07/09/2020] [Indexed: 12/25/2022] Open
Abstract
Systems biology has experienced dramatic growth in the number, size, and complexity of computational models. To reproduce simulation results and reuse models, researchers must exchange unambiguous model descriptions. We review the latest edition of the Systems Biology Markup Language (SBML), a format designed for this purpose. A community of modelers and software authors developed SBML Level 3 over the past decade. Its modular form consists of a core suited to representing reaction-based models and packages that extend the core with features suited to other model types including constraint-based models, reaction-diffusion models, logical network models, and rule-based models. The format leverages two decades of SBML and a rich software ecosystem that transformed how systems biologists build and interact with models. More recently, the rise of multiscale models of whole cells and organs, and new data sources such as single-cell measurements and live imaging, has precipitated new ways of integrating data with models. We provide our perspectives on the challenges presented by these developments and how SBML Level 3 provides the foundation needed to support this evolution.
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Smith LP, Moodie SL, Bergmann FT, Gillespie C, Keating SM, König M, Myers CJ, Swat MJ, Wilkinson DJ, Hucka M. Systems Biology Markup Language (SBML) Level 3 Package: Distributions, Version 1, Release 1. J Integr Bioinform 2020; 17:jib-2020-0018. [PMID: 32750035 PMCID: PMC7756622 DOI: 10.1515/jib-2020-0018] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Accepted: 04/17/2020] [Indexed: 11/23/2022] Open
Abstract
Biological models often contain elements that have inexact numerical values, since they are based on values that are stochastic in nature or data that contains uncertainty. The Systems Biology Markup Language (SBML) Level 3 Core specification does not include an explicit mechanism to include inexact or stochastic values in a model, but it does provide a mechanism for SBML packages to extend the Core specification and add additional syntactic constructs. The SBML Distributions package for SBML Level 3 adds the necessary features to allow models to encode information about the distribution and uncertainty of values underlying a quantity.
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Farrash W, Brook M, Crossland H, Phillips BE, Cegielski J, Wilkinson DJ, Constantin-Teodosiu D, Greenhaff PL, Smith K, Cleasby M, Atherton PJ. Impacts of rat hindlimb Fndc5/irisin overexpression on muscle and adipose tissue metabolism. Am J Physiol Endocrinol Metab 2020; 318:E943-E955. [PMID: 32369414 PMCID: PMC7311674 DOI: 10.1152/ajpendo.00034.2020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Myokines, such as irisin, have been purported to exert physiological effects on skeletal muscle in an autocrine/paracrine fashion. In this study, we aimed to investigate the mechanistic role of in vivo fibronectin type III domain-containing 5 (Fndc5)/irisin upregulation in muscle. Overexpression (OE) of Fndc5 in rat hindlimb muscle was achieved by in vivo electrotransfer, i.e., bilateral injections of Fndc5 harboring vectors for OE rats (n = 8) and empty vector for control rats (n = 8). Seven days later, a bolus of D2O (7.2 mL/kg) was administered via oral gavage to quantify muscle protein synthesis. After an overnight fast, on day 9, 2-deoxy-d-glucose-6-phosphate (2-DG6P; 6 mg/kg) was provided during an intraperitoneal glucose tolerance test (2 g/kg) to assess glucose handling. Animals were euthanized, musculus tibialis cranialis muscles and subcutaneous fat (inguinal) were harvested, and metabolic and molecular effects were evaluated. Muscle Fndc5 mRNA increased with OE (~2-fold; P = 0.014), leading to increased circulating irisin (1.5 ± 0.9 to 3.5 ± 1.2 ng/mL; P = 0.049). OE had no effect on protein anabolism or mitochondrial biogenesis; however, muscle glycogen was increased, along with glycogen synthase 1 gene expression (P = 0.04 and 0.02, respectively). In addition to an increase in glycogen synthase activation in OE (P = 0.03), there was a tendency toward increased glucose transporter 4 protein (P = 0.09). However, glucose uptake (accumulation of 2-DG6P) was identical. Irisin elicited no endocrine effect on mitochondrial biogenesis or uncoupling proteins in white adipose tissue. Hindlimb overexpression led to physiological increases in Fndc5/irisin. However, our data indicate limited short-term impacts of irisin in relation to muscle anabolism, mitochondrial biogenesis, glucose uptake, or adipose remodeling.
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Affiliation(s)
- W Farrash
- Medical Research Council Versus Arthritis Centre for Musculoskeletal Ageing Research and Nottingham National Institute for Health Research Biomedical Research Centre, School of Medicine, University of Nottingham, Derby, United Kingdom
- College of Applied Medical Sciences, Umm Al-Qura University, Makkah, Saudi Arabia
| | - M Brook
- Medical Research Council Versus Arthritis Centre for Musculoskeletal Ageing Research and Nottingham National Institute for Health Research Biomedical Research Centre, School of Medicine, University of Nottingham, Derby, United Kingdom
| | - H Crossland
- Medical Research Council Versus Arthritis Centre for Musculoskeletal Ageing Research and Nottingham National Institute for Health Research Biomedical Research Centre, School of Medicine, University of Nottingham, Derby, United Kingdom
| | - B E Phillips
- Medical Research Council Versus Arthritis Centre for Musculoskeletal Ageing Research and Nottingham National Institute for Health Research Biomedical Research Centre, School of Medicine, University of Nottingham, Derby, United Kingdom
| | - J Cegielski
- Medical Research Council Versus Arthritis Centre for Musculoskeletal Ageing Research and Nottingham National Institute for Health Research Biomedical Research Centre, School of Medicine, University of Nottingham, Derby, United Kingdom
| | - D J Wilkinson
- Medical Research Council Versus Arthritis Centre for Musculoskeletal Ageing Research and Nottingham National Institute for Health Research Biomedical Research Centre, School of Medicine, University of Nottingham, Derby, United Kingdom
| | - D Constantin-Teodosiu
- Medical Research Council Versus Arthritis Centre for Musculoskeletal Ageing Research, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - P L Greenhaff
- Medical Research Council Versus Arthritis Centre for Musculoskeletal Ageing Research, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - K Smith
- Medical Research Council Versus Arthritis Centre for Musculoskeletal Ageing Research and Nottingham National Institute for Health Research Biomedical Research Centre, School of Medicine, University of Nottingham, Derby, United Kingdom
| | - M Cleasby
- Molecular Physiology of Diabetes Laboratory, Department of Comparative Biomedical Sciences, Royal Veterinary College, University of London, London, United Kingdom
| | - P J Atherton
- Medical Research Council Versus Arthritis Centre for Musculoskeletal Ageing Research and Nottingham National Institute for Health Research Biomedical Research Centre, School of Medicine, University of Nottingham, Derby, United Kingdom
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Green PA, Wilkinson DJ, Bouamra O, Fragoso M, Farrelly PJ. Variations in the management of adolescents with blunt splenic trauma in England and Wales: are we preserving enough? Ann R Coll Surg Engl 2020; 102:488-492. [PMID: 32326736 DOI: 10.1308/rcsann.2020.0053] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
INTRODUCTION Management of blunt splenic injury has changed drastically with non-operative management increasingly used in paediatric and adult patients. Studies from America and Australia demonstrate disparities in care of patients treated at paediatric and adult centres. This study assessed management of splenic injuries in UK adolescents. MATERIALS AND METHODS Data were acquired from the Trauma Audit and Research Network on isolated blunt splenic injuries reported 2006-2015. Adolescents were divided into age groups of 11-15 years and 16-20 years, and injuries classified as minor (grades 1/2) or major (3+). Primary outcomes were needed for splenectomy and blood transfusion. RESULTS A total of 445 adolescents suffered isolated blunt splenic injuries. Road traffic collisions were the most common mechanism. There were no deaths as a result of isolated blunt splenic injuries, but 49 (11%) adolescents needed transfusions and 105 (23.6%) underwent splenectomies. There was no significant difference observed in the management of adolescents with minor trauma. In major trauma, 11-15-year-olds were more likely to have splenectomies when managed at local trauma units compared with major trauma centres (31% vs 4%, odds ratio 11.5; 95% confidence interval 3.82-34.38, p < 0.0001). Within major trauma centres, older adolescents were more likely to have splenectomies than younger adolescents (35.5% vs 3.8%, odds ratio 14; 95% confidence interval 4.55-43.26, p < 0.0001). There were no significant differences in haemodynamic status, transfusion requirement or embolisation rates. CONCLUSIONS There appears to be a large variation in the management of isolated blunt splenic injuries in the UK. The reasons for this remain unclear however non-operative management is safe and should be first line management in the haemodynamically stable adolescent, even with major splenic injuries.
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Affiliation(s)
- P A Green
- Royal Manchester Children's Hospital, Manchester, UK
| | - D J Wilkinson
- Royal Manchester Children's Hospital, Manchester, UK
| | - O Bouamra
- Trauma Audit and Research Network, Salford, UK
| | - M Fragoso
- Trauma Audit and Research Network, Salford, UK
| | - P J Farrelly
- Royal Manchester Children's Hospital, Manchester, UK
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7
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Lee C, Wilkinson DJ. A Hierarchical Model of Nonhomogeneous Poisson Processes for Twitter Retweets. J Am Stat Assoc 2020. [DOI: 10.1080/01621459.2019.1585358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Clement Lee
- School of Mathematics, Statistics and Physics, Newcastle University, Newcastle upon Tyne, UK
- Open Lab, School of Computing, Newcastle University, Newcastle upon Tyne, UK
| | - Darren J. Wilkinson
- School of Mathematics, Statistics and Physics, Newcastle University, Newcastle upon Tyne, UK
- The Alan Turing Institute, UK
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Mitchell AL, Scheremetjew M, Denise H, Potter S, Tarkowska A, Qureshi M, Salazar GA, Pesseat S, Boland MA, Hunter F, ten Hoopen P, Alako B, Amid C, Wilkinson DJ, Curtis TP, Cochrane G, Finn RD. EBI Metagenomics in 2017: enriching the analysis of microbial communities, from sequence reads to assemblies. Nucleic Acids Res 2019; 46:D726-D735. [PMID: 29069476 PMCID: PMC5753268 DOI: 10.1093/nar/gkx967] [Citation(s) in RCA: 121] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 10/12/2017] [Indexed: 01/16/2023] Open
Abstract
EBI metagenomics (http://www.ebi.ac.uk/metagenomics) provides a free to use platform for the analysis and archiving of sequence data derived from the microbial populations found in a particular environment. Over the past two years, EBI metagenomics has increased the number of datasets analysed 10-fold. In addition to increased throughput, the underlying analysis pipeline has been overhauled to include both new or updated tools and reference databases. Of particular note is a new workflow for taxonomic assignments that has been extended to include assignments based on both the large and small subunit RNA marker genes and to encompass all cellular micro-organisms. We also describe the addition of metagenomic assembly as a new analysis service. Our pilot studies have produced over 2400 assemblies from datasets in the public domain. From these assemblies, we have produced a searchable, non-redundant protein database of over 50 million sequences. To provide improved access to the data stored within the resource, we have developed a programmatic interface that provides access to the analysis results and associated sample metadata. Finally, we have integrated the results of a series of statistical analyses that provide estimations of diversity and sample comparisons.
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Affiliation(s)
- Alex L Mitchell
- EMBL-EBI European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK
- To whom correspondence should be addressed. Tel: +44 1223 494652; . Correspondence may also be addressed to Robert D. Finn. Tel: +44 1223 492678;
| | - Maxim Scheremetjew
- EMBL-EBI European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK
| | - Hubert Denise
- EMBL-EBI European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK
| | - Simon Potter
- EMBL-EBI European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK
| | - Aleksandra Tarkowska
- EMBL-EBI European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK
| | - Matloob Qureshi
- EMBL-EBI European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK
| | - Gustavo A Salazar
- EMBL-EBI European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK
| | - Sebastien Pesseat
- EMBL-EBI European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK
| | - Miguel A Boland
- EMBL-EBI European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK
| | - Fiona M I Hunter
- EMBL-EBI European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK
| | - Petra ten Hoopen
- EMBL-EBI European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK
| | - Blaise Alako
- EMBL-EBI European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK
| | - Clara Amid
- EMBL-EBI European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK
| | - Darren J Wilkinson
- School of Mathematics & Statistics, Newcastle University, Newcastle upon Tyne NE1 7RU, UK
| | - Thomas P Curtis
- School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne NE1 7RU, UK
| | - Guy Cochrane
- EMBL-EBI European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK
| | - Robert D Finn
- EMBL-EBI European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK
- To whom correspondence should be addressed. Tel: +44 1223 494652; . Correspondence may also be addressed to Robert D. Finn. Tel: +44 1223 492678;
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Hucka M, Bergmann FT, Chaouiya C, Dräger A, Hoops S, Keating SM, König M, Novère NL, Myers CJ, Olivier BG, Sahle S, Schaff JC, Sheriff R, Smith LP, Waltemath D, Wilkinson DJ, Zhang F. The Systems Biology Markup Language (SBML): Language Specification for Level 3 Version 2 Core Release 2. J Integr Bioinform 2019; 16:/j/jib.ahead-of-print/jib-2019-0021/jib-2019-0021.xml. [PMID: 31219795 PMCID: PMC6798823 DOI: 10.1515/jib-2019-0021] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Accepted: 05/20/2019] [Indexed: 11/15/2022] Open
Abstract
Computational models can help researchers to interpret data, understand biological functions, and make quantitative predictions. The Systems Biology Markup Language (SBML) is a file format for representing computational models in a declarative form that different software systems can exchange. SBML is oriented towards describing biological processes of the sort common in research on a number of topics, including metabolic pathways, cell signaling pathways, and many others. By supporting SBML as an input/output format, different tools can all operate on an identical representation of a model, removing opportunities for translation errors and assuring a common starting point for analyses and simulations. This document provides the specification for Release 2 of Version 2 of SBML Level 3 Core. The specification defines the data structures prescribed by SBML as well as their encoding in XML, the eXtensible Markup Language. Release 2 corrects some errors and clarifies some ambiguities discovered in Release 1. This specification also defines validation rules that determine the validity of an SBML document, and provides many examples of models in SBML form. Other materials and software are available from the SBML project website at http://sbml.org/.
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Affiliation(s)
- Michael Hucka
- California Institute of Technology, Pasadena, CA, USA
| | | | | | - Andreas Dräger
- Department of Computer Science, University of Tübingen, Tübingen, Germany.,Computational Systems Biology of Infection and Antimicrobial-Resistant Pathogens, Institute for Biomedical Informatics (IBMI), University of Tübingen, Tübingen, Germany.,German Center for Infection Research (DZIF), Tübingen, Germany
| | - Stefan Hoops
- Virginia Bioinformatics Institute, Blacksburg, VA, USA
| | | | | | | | | | | | - Sven Sahle
- University of Heidelberg, Heidelberg, Germany
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Wilkinson DJ, Hossain T, Limb MC, Phillips BE, Lund J, Williams JP, Brook MS, Cegielski J, Philp A, Ashcroft S, Rathmacher JA, Szewczyk NJ, Smith K, Atherton PJ. Impact of the calcium form of β-hydroxy-β-methylbutyrate upon human skeletal muscle protein metabolism. Clin Nutr 2018; 37:2068-2075. [PMID: 29097038 PMCID: PMC6295980 DOI: 10.1016/j.clnu.2017.09.024] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 09/24/2017] [Accepted: 09/29/2017] [Indexed: 12/20/2022]
Abstract
BACKGROUND & AIMS β-hydroxy-β-methylbutyrate (HMB) is purported as a key nutritional supplement for the preservation of muscle mass in health, disease and as an ergogenic aid in exercise. Of the two available forms of HMB (calcium (Ca-HMB) salt or free acid (FA-HMB)) - differences in plasma bioavailability have been reported. We previously reported that ∼3 g oral FA-HMB increased muscle protein synthesis (MPS) and reduced muscle protein breakdown (MPB). The objective of the present study was to quantify muscle protein metabolism responses to oral Ca-HMB. METHODS Eight healthy young males received a primed constant infusion of 1,2 13C2 leucine and 2H5 phenylalanine to assess MPS (by tracer incorporation in myofibrils) and MPB (via arterio-venous (A-V) dilution) at baseline and following provision of ∼3 g of Ca-HMB; muscle anabolic (MPS) and catabolic (MPB) signalling was assessed via immunoblotting. RESULTS Ca-HMB led a significant and rapid (<60 min) peak in plasma HMB concentrations (483.6 ± 14.2 μM, p < 0.0001). This rise in plasma HMB was accompanied by increases in MPS (PA: 0.046 ± 0.004%/h, CaHMB: 0.072 ± 0.004%/h, p < 0001) and suppressions in MPB (PA: 7.6 ± 1.2 μmol Phe per leg min-1, Ca-HMB: 5.2 ± 0.8 μmol Phe per leg min-1, p < 0.01). Increases in the phosphorylation of mTORc1 substrates i.e. p70S6K1 and RPS6 were also observed, with no changes detected in the MPB targets measured. CONCLUSIONS These findings support the pro-anabolic properties of HMB via mTORc1, and show that despite proposed differences in bioavailability, Ca-HMB provides a comparable stimulation to MPS and suppression of MPB, to FA-HMB, further supporting its use as a pharmaconutrient in the modulation of muscle mass.
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Affiliation(s)
- D J Wilkinson
- MRC-ARUK Centre for Musculoskeletal Ageing Research, National Institute for Health Research Nottingham Biomedical Research Centre, Clinical, Metabolic and Molecular Physiology, University of Nottingham, Royal Derby Hospital Centre, Derby, UK
| | - T Hossain
- MRC-ARUK Centre for Musculoskeletal Ageing Research, National Institute for Health Research Nottingham Biomedical Research Centre, Clinical, Metabolic and Molecular Physiology, University of Nottingham, Royal Derby Hospital Centre, Derby, UK
| | - M C Limb
- MRC-ARUK Centre for Musculoskeletal Ageing Research, National Institute for Health Research Nottingham Biomedical Research Centre, Clinical, Metabolic and Molecular Physiology, University of Nottingham, Royal Derby Hospital Centre, Derby, UK
| | - B E Phillips
- MRC-ARUK Centre for Musculoskeletal Ageing Research, National Institute for Health Research Nottingham Biomedical Research Centre, Clinical, Metabolic and Molecular Physiology, University of Nottingham, Royal Derby Hospital Centre, Derby, UK
| | - J Lund
- MRC-ARUK Centre for Musculoskeletal Ageing Research, National Institute for Health Research Nottingham Biomedical Research Centre, Clinical, Metabolic and Molecular Physiology, University of Nottingham, Royal Derby Hospital Centre, Derby, UK
| | - J P Williams
- MRC-ARUK Centre for Musculoskeletal Ageing Research, National Institute for Health Research Nottingham Biomedical Research Centre, Clinical, Metabolic and Molecular Physiology, University of Nottingham, Royal Derby Hospital Centre, Derby, UK
| | - M S Brook
- MRC-ARUK Centre for Musculoskeletal Ageing Research, National Institute for Health Research Nottingham Biomedical Research Centre, Clinical, Metabolic and Molecular Physiology, University of Nottingham, Royal Derby Hospital Centre, Derby, UK
| | - J Cegielski
- MRC-ARUK Centre for Musculoskeletal Ageing Research, National Institute for Health Research Nottingham Biomedical Research Centre, Clinical, Metabolic and Molecular Physiology, University of Nottingham, Royal Derby Hospital Centre, Derby, UK
| | - A Philp
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, UK
| | - S Ashcroft
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, UK
| | - J A Rathmacher
- Metabolic Technologies, Inc, Iowa State University Research Park, 2711 S. Loop Drive, Ste 4400, Ames, IA 50010, USA
| | - N J Szewczyk
- MRC-ARUK Centre for Musculoskeletal Ageing Research, National Institute for Health Research Nottingham Biomedical Research Centre, Clinical, Metabolic and Molecular Physiology, University of Nottingham, Royal Derby Hospital Centre, Derby, UK
| | - K Smith
- MRC-ARUK Centre for Musculoskeletal Ageing Research, National Institute for Health Research Nottingham Biomedical Research Centre, Clinical, Metabolic and Molecular Physiology, University of Nottingham, Royal Derby Hospital Centre, Derby, UK
| | - P J Atherton
- MRC-ARUK Centre for Musculoskeletal Ageing Research, National Institute for Health Research Nottingham Biomedical Research Centre, Clinical, Metabolic and Molecular Physiology, University of Nottingham, Royal Derby Hospital Centre, Derby, UK.
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11
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Din USU, Brook MS, Selby A, Quinlan J, Boereboom C, Abdulla H, Franchi M, Narici MV, Phillips BE, Williams JW, Rathmacher JA, Wilkinson DJ, Atherton PJ, Smith K. A double-blind placebo controlled trial into the impacts of HMB supplementation and exercise on free-living muscle protein synthesis, muscle mass and function, in older adults. Clin Nutr 2018; 38:2071-2078. [PMID: 30360984 PMCID: PMC6876270 DOI: 10.1016/j.clnu.2018.09.025] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 09/11/2018] [Accepted: 09/24/2018] [Indexed: 01/06/2023]
Abstract
Age-related sarcopenia and dynapenia are associated with frailty and metabolic diseases. Resistance exercise training (RET) adjuvant to evidence-based nutritional intervention(s) have been shown as mitigating strategies. Given that β-hydroxy-β-methyl-butyrate (HMB) supplementation during RET improves lean body mass in younger humans, and that we have shown that HMB acutely stimulates muscle protein synthesis (MPS) and inhibits breakdown; we hypothesized that chronic supplementation of HMB free acid (HMB-FA) would enhance MPS and muscle mass/function in response to RET in older people. We recruited 16 healthy older men (Placebo (PLA): 68.5 ± 1.0 y, HMB-FA: 67.8 ± 1.15 y) for a randomised double-blind-placebo controlled trial (HMB-FA 3 × 1 g/day vs. PLA) involving a 6-week unilateral progressive RET regime (6 × 8 repetitions, 75% 1-RM, 3 · wk−1). Deuterium oxide (D2O) dosing was performed over the first two weeks (0–2 wk) and last two weeks (4–6 wk) with bilateral vastus lateralis (VL) biopsies at 0–2 and 4–6 wk (each time 75 ± 2 min after a single bout of resistance exercise (RE)) for quantification of early and later MPS responses and post-RE myogenic gene expression. Thigh lean mass (TLM) was measured by DXA, VL thickness and architecture (fibre length and pennation angle) by ultrasound at 0/3/6 wk, and strength by knee extensor 1-RM testing and MVC by isokinetic dynamometry (approx. every 10 days). RET induced strength increases (1-RM) in the exercised leg of both groups (398 ± 22N to 499 ± 30N HMB-FA vs. 396 ± 29N to 510 ± 43N PLA (both P < 0.05)). In addition, maximal voluntary contraction (MVC) also increased (179 ± 12 Nm to 203 ± 12 Nm HMB-FA vs. 185 ± 10 Nm to 217 ± 11 Nm PLA (both P < 0.05); with no group differences. VL muscle thickness increased significantly in the exercised leg in both groups, with no group differences. TLM (by DXA) rose to significance only in the HMB-FA group (by 5.8%–5734 ± 245 g p = 0.015 vs. 3.0% to 5644 ± 323 g P = 0.06 in PLA). MPS remained unchanged in the untrained legs (UT) 0–2 weeks being 1.06 ± 0.08%.d−1 (HMB-FA) and 1.14 ± 0.09%.d−1 (PLA), the trained legs (T) exhibited increased MPS in the HMB-FA group only at 0–2-weeks (1.39 ± 0.10%.d−1, P < 0.05) compared with UT: but was not different at 4–6-weeks: 1.26 ± 0.05%.d−1. However, there were no significant differences in MPS between the HMB-FA and PLA groups at any given time point and no significant treatment interaction observed. We also observed significant inductions of c-Myc gene expression following each acute RE bout, with no group differences. Further, there were no changes in any other muscle atrophy/hypertrophy or myogenic transcription factor genes we measured. RET with adjuvant HMB-FA supplements in free-living healthy older men did not enhance muscle strength or mass greater than that of RET alone (PLA). That said, only HMB-FA increased TLM, supported by early increases in chronic MPS. As such, chronic HMB-FA supplementation may result in long term benefits in older males, however longer and larger studies may be needed to fully determine the potential effects of HMB-FA supplementation; translating to any functional benefit.
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Affiliation(s)
- U S U Din
- MRC-ARUK Centre for Musculoskeletal Ageing Research, Clinical, Metabolic and Molecular Physiology, University of Nottingham, Royal Derby Hospital Centre, Derby, UK
| | - M S Brook
- MRC-ARUK Centre for Musculoskeletal Ageing Research, Clinical, Metabolic and Molecular Physiology, University of Nottingham, Royal Derby Hospital Centre, Derby, UK; Nottingham NIHR BRC, UK
| | - A Selby
- MRC-ARUK Centre for Musculoskeletal Ageing Research, Clinical, Metabolic and Molecular Physiology, University of Nottingham, Royal Derby Hospital Centre, Derby, UK
| | - J Quinlan
- MRC-ARUK Centre for Musculoskeletal Ageing Research, Clinical, Metabolic and Molecular Physiology, University of Nottingham, Royal Derby Hospital Centre, Derby, UK
| | - C Boereboom
- MRC-ARUK Centre for Musculoskeletal Ageing Research, Clinical, Metabolic and Molecular Physiology, University of Nottingham, Royal Derby Hospital Centre, Derby, UK
| | - H Abdulla
- MRC-ARUK Centre for Musculoskeletal Ageing Research, Clinical, Metabolic and Molecular Physiology, University of Nottingham, Royal Derby Hospital Centre, Derby, UK
| | - M Franchi
- MRC-ARUK Centre for Musculoskeletal Ageing Research, Clinical, Metabolic and Molecular Physiology, University of Nottingham, Royal Derby Hospital Centre, Derby, UK
| | - M V Narici
- MRC-ARUK Centre for Musculoskeletal Ageing Research, Clinical, Metabolic and Molecular Physiology, University of Nottingham, Royal Derby Hospital Centre, Derby, UK
| | - B E Phillips
- MRC-ARUK Centre for Musculoskeletal Ageing Research, Clinical, Metabolic and Molecular Physiology, University of Nottingham, Royal Derby Hospital Centre, Derby, UK; Nottingham NIHR BRC, UK
| | - J W Williams
- MRC-ARUK Centre for Musculoskeletal Ageing Research, Clinical, Metabolic and Molecular Physiology, University of Nottingham, Royal Derby Hospital Centre, Derby, UK
| | - J A Rathmacher
- Metabolic Technologies, Inc, Iowa State University Research Park, 2711 S. Loop Drive, Ste 4400, Ames, IA, 50010, USA
| | - D J Wilkinson
- MRC-ARUK Centre for Musculoskeletal Ageing Research, Clinical, Metabolic and Molecular Physiology, University of Nottingham, Royal Derby Hospital Centre, Derby, UK; Nottingham NIHR BRC, UK
| | - P J Atherton
- MRC-ARUK Centre for Musculoskeletal Ageing Research, Clinical, Metabolic and Molecular Physiology, University of Nottingham, Royal Derby Hospital Centre, Derby, UK; Nottingham NIHR BRC, UK
| | - K Smith
- MRC-ARUK Centre for Musculoskeletal Ageing Research, Clinical, Metabolic and Molecular Physiology, University of Nottingham, Royal Derby Hospital Centre, Derby, UK; Nottingham NIHR BRC, UK.
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Hucka M, Bergmann FT, Dräger A, Hoops S, Keating SM, Le Novère N, Myers CJ, Olivier BG, Sahle S, Schaff JC, Smith LP, Waltemath D, Wilkinson DJ. The Systems Biology Markup Language (SBML): Language Specification for Level 3 Version 1 Core. J Integr Bioinform 2018. [PMCID: PMC6167037 DOI: 10.1515/jib-2017-0080] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Computational models can help researchers to interpret data, understand biological functions, and make quantitative predictions. The Systems Biology Markup Language (SBML) is a file format for representing computational models in a declarative form that different software systems can exchange. SBML is oriented towards describing biological processes of the sort common in research on a number of topics, including metabolic pathways, cell signaling pathways, and many others. By supporting SBML as an input/output format, different tools can all operate on an identical representation of a model, removing opportunities for translation errors and assuring a common starting point for analyses and simulations. This document provides the specification for Release 2 of Version 1 of SBML Level 3 Core. The specification defines the data structures prescribed by SBML, their encoding in XML (the eXtensible Markup Language), validation rules that determine the validity of an SBML document, and examples of models in SBML form. No design changes have been made to the description of models between Release 1 and Release 2; changes are restricted to the format of annotations, the correction of errata and the addition of clarifications. Other materials and software are available from the SBML project website at http://sbml.org/.
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Affiliation(s)
- Michael Hucka
- California Institute of Technology, Pasadena, CA, USA
| | | | - Andreas Dräger
- Applied Bioinformatics Group, Center for Bioinformatics Tübingen (ZBIT), University of Tübingen, Sand 14, Office # C320, 72076 Tübingen, Germany
| | - Stefan Hoops
- Biocomplexity Institute of Virginia Tech, Blacksburg, Va 24061, USA
| | - Sarah M. Keating
- European Bioinformatics Institute, Hinxton, Cambridge, United Kingdom of Great Britain and Northern Ireland
| | - Nicolas Le Novère
- Babraham Institute, Cambridge, Cambridgeshire, United Kingdom of Great Britain and Northern Ireland
| | | | | | - Sven Sahle
- University of Heidelberg, Heidelberg, Germany
| | | | | | | | - Darren J. Wilkinson
- Newcastle University, Newcastle, United Kingdom of Great Britain and Northern Ireland
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Oyebamiji OK, Wilkinson DJ, Jayathilake PG, Rushton SP, Bridgens B, Li B, Zuliani P. A Bayesian approach to modelling the impact of hydrodynamic shear stress on biofilm deformation. PLoS One 2018; 13:e0195484. [PMID: 29649240 PMCID: PMC5896950 DOI: 10.1371/journal.pone.0195484] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 03/24/2018] [Indexed: 11/18/2022] Open
Abstract
We investigate the feasibility of using a surrogate-based method to emulate the deformation and detachment behaviour of a biofilm in response to hydrodynamic shear stress. The influence of shear force, growth rate and viscoelastic parameters on the patterns of growth, structure and resulting shape of microbial biofilms was examined. We develop a statistical modelling approach to this problem, using combination of Bayesian Poisson regression and dynamic linear models for the emulation. We observe that the hydrodynamic shear force affects biofilm deformation in line with some literature. Sensitivity results also showed that the expected number of shear events, shear flow, yield coefficient for heterotrophic bacteria and extracellular polymeric substance (EPS) stiffness per unit EPS mass are the four principal mechanisms governing the bacteria detachment in this study. The sensitivity of the model parameters is temporally dynamic, emphasising the significance of conducting the sensitivity analysis across multiple time points. The surrogate models are shown to perform well, and produced ≈ 480 fold increase in computational efficiency. We conclude that a surrogate-based approach is effective, and resulting biofilm structure is determined primarily by a balance between bacteria growth, viscoelastic parameters and applied shear stress.
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Affiliation(s)
- Oluwole K. Oyebamiji
- School of Mathematics, Statistics and Physics, Newcastle University, Newcastle upon Tyne, NE1 7RU, United Kingdom
- * E-mail:
| | - Darren J. Wilkinson
- School of Mathematics, Statistics and Physics, Newcastle University, Newcastle upon Tyne, NE1 7RU, United Kingdom
| | | | - Steve P. Rushton
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, NE1 7RU, United Kingdom
| | - Ben Bridgens
- School of Engineering, Newcastle University, Newcastle upon Tyne, NE1 7RU, United Kingdom
| | - Bowen Li
- School of Computing Science, Newcastle University, Newcastle upon Tyne, NE4 5TG, United Kingdom
| | - Paolo Zuliani
- School of Computing Science, Newcastle University, Newcastle upon Tyne, NE4 5TG, United Kingdom
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14
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Hucka M, Bergmann FT, Dräger A, Hoops S, Keating SM, Le Novère N, Myers CJ, Olivier BG, Sahle S, Schaff JC, Smith LP, Waltemath D, Wilkinson DJ. The Systems Biology Markup Language (SBML): Language Specification for Level 3 Version 2 Core. J Integr Bioinform 2018. [PMID: 29522418 PMCID: PMC6167032 DOI: 10.1515/jib-2017-0081] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Computational models can help researchers to interpret data, understand biological functions, and make quantitative predictions. The Systems Biology Markup Language (SBML) is a file format for representing computational models in a declarative form that different software systems can exchange. SBML is oriented towards describing biological processes of the sort common in research on a number of topics, including metabolic pathways, cell signaling pathways, and many others. By supporting SBML as an input/output format, different tools can all operate on an identical representation of a model, removing opportunities for translation errors and assuring a common starting point for analyses and simulations. This document provides the specification for Version 2 of SBML Level 3 Core. The specification defines the data structures prescribed by SBML, their encoding in XML (the eXtensible Markup Language), validation rules that determine the validity of an SBML document, and examples of models in SBML form. The design of Version 2 differs from Version 1 principally in allowing new MathML constructs, making more child elements optional, and adding identifiers to all SBML elements instead of only selected elements. Other materials and software are available from the SBML project website at http://sbml.org/.
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Affiliation(s)
- Michael Hucka
- California Institute of Technology, Pasadena, CA, USA
| | | | - Andreas Dräger
- Applied Bioinformatics Group, Center for Bioinformatics Tübingen (ZBIT), University of Tübingen, Sand 14, Office # C320, 72076 Tübingen, Germany
| | - Stefan Hoops
- Biocomplexity Institute of Virginia Tech, Blacksburg, Va 24061, USA
| | - Sarah M Keating
- European Bioinformatics Institute, Hinxton, Cambridge, United Kingdom of Great Britain and Northern Ireland
| | - Nicolas Le Novère
- Babraham Institute, Cambridge, Cambridgeshire, United Kingdom of Great Britain and Northern Ireland
| | | | | | - Sven Sahle
- University of Heidelberg, Heidelberg, Germany
| | | | | | | | - Darren J Wilkinson
- Newcastle University, Newcastle, United Kingdom of Great Britain and Northern Ireland
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Paris JJ, Ahluwalia J, Cummings BM, Moreland MP, Wilkinson DJ. The Charlie Gard case: British and American approaches to court resolution of disputes over medical decisions. J Perinatol 2017; 37:1268-1271. [PMID: 29048408 PMCID: PMC5712473 DOI: 10.1038/jp.2017.138] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Accepted: 06/29/2017] [Indexed: 02/03/2023]
Affiliation(s)
- J J Paris
- Department of Bioethics, Boston College, Chestnut Hill, MA, USA
- Campion Hall, Oxford University, Oxford, UK
| | | | - B M Cummings
- Department of Pediatrics, Massachusetts General Hospital, Boston, MA, USA
| | - M P Moreland
- Villanova University School of Law, Villanova, PA, USA
| | - D J Wilkinson
- John Radcliffe Hospital, Oxford, UK
- Oxford Uehiro Center for Practical Ethics, University of Oxford, Oxford, UK
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16
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Brook MS, Wilkinson DJ, Mitchell WK, Lund JL, Phillips BE, Szewczyk NJ, Kainulainen H, Lensu S, Koch LG, Britton SL, Greenhaff PL, Smith K, Atherton PJ. A novel D 2O tracer method to quantify RNA turnover as a biomarker of de novo ribosomal biogenesis, in vitro, in animal models, and in human skeletal muscle. Am J Physiol Endocrinol Metab 2017; 313:E681-E689. [PMID: 28811296 PMCID: PMC5814597 DOI: 10.1152/ajpendo.00157.2017] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 08/10/2017] [Accepted: 08/14/2017] [Indexed: 11/22/2022]
Abstract
Current methods to quantify in vivo RNA dynamics are limited. Here, we developed a novel stable isotope (D2O) methodology to quantify RNA synthesis (i.e., ribosomal biogenesis) in cells, animal models, and humans. First, proliferating C2C12 cells were incubated in D2O-enriched media and myotubes ±50 ng/ml IGF-I. Second, rat quadriceps (untrained, n = 9; 7-wk interval-"like" training, n = 13) were collected after ~3-wk D2O (70 atom %) administration, with body-water enrichment monitored via blood sampling. Finally, 10 (23 ± 1 yr) men consumed 150-ml D2O followed by 50 ml/wk and undertook 6-wk resistance exercise (6 × 8 repetitions, 75% 1-repetition maximum 3/wk) with body-water enrichment monitored by saliva sampling and muscle biopsies (for determination of RNA synthesis) at 0, 3, and 6 wk. Ribose mole percent excess (r-MPE) from purine nucleotides was analyzed via GC-MS/MS. Proliferating C2C12 cell r-MPE exhibited a rise to plateau, whereas IGF-I increased myotube RNA from 76 ± 3 to 123 ± 3 ng/μl and r-MPE by 0.39 ± 0.1% (both P < 0.01). After 3 wk, rat quadriceps r-MPE had increased to 0.25 ± 0.01% (P < 0.01) and was greater with running exercise (0.36 ± 0.02%; P < 0.01). Human muscle r-MPE increased to 0.06 ± 0.01 and 0.13 ± 0.02% at 3/6 wk, respectively, equating to synthesis rates of ~0.8%/day, increasing with resistance exercise to 1.7 ± 0.3%/day (P < 0.01) and 1.2 ± 0.1%/day (P < 0.05) at 3/6 wk, respectively. Therefore, we have developed and physiologically validated a novel technique to explore ribosomal biogenesis in a multimodal fashion.
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Affiliation(s)
- M S Brook
- Medical Research Council-Arthritis Research UK Centre for Musculoskeletal Ageing Research, Clinical, Metabolic and Molecular Physiology, University of Nottingham, Royal Derby Hospital Centre, Derby, United Kingdom
| | - D J Wilkinson
- Medical Research Council-Arthritis Research UK Centre for Musculoskeletal Ageing Research, Clinical, Metabolic and Molecular Physiology, University of Nottingham, Royal Derby Hospital Centre, Derby, United Kingdom
| | - W K Mitchell
- Medical Research Council-Arthritis Research UK Centre for Musculoskeletal Ageing Research, Clinical, Metabolic and Molecular Physiology, University of Nottingham, Royal Derby Hospital Centre, Derby, United Kingdom
| | - J L Lund
- Medical Research Council-Arthritis Research UK Centre for Musculoskeletal Ageing Research, Clinical, Metabolic and Molecular Physiology, University of Nottingham, Royal Derby Hospital Centre, Derby, United Kingdom
| | - B E Phillips
- Medical Research Council-Arthritis Research UK Centre for Musculoskeletal Ageing Research, Clinical, Metabolic and Molecular Physiology, University of Nottingham, Royal Derby Hospital Centre, Derby, United Kingdom
| | - N J Szewczyk
- Medical Research Council-Arthritis Research UK Centre for Musculoskeletal Ageing Research, Clinical, Metabolic and Molecular Physiology, University of Nottingham, Royal Derby Hospital Centre, Derby, United Kingdom
| | - H Kainulainen
- Department of Biology of Physical Activity, University of Jyväskylä, Jyväskylä, Finland; and
| | - S Lensu
- Department of Biology of Physical Activity, University of Jyväskylä, Jyväskylä, Finland; and
| | - L G Koch
- Department of Anesthesiology, University of Michigan, Ann Arbor, Michigan
| | - S L Britton
- Department of Anesthesiology, University of Michigan, Ann Arbor, Michigan
| | - P L Greenhaff
- Medical Research Council-Arthritis Research UK Centre for Musculoskeletal Ageing Research, Clinical, Metabolic and Molecular Physiology, University of Nottingham, Royal Derby Hospital Centre, Derby, United Kingdom
| | - K Smith
- Medical Research Council-Arthritis Research UK Centre for Musculoskeletal Ageing Research, Clinical, Metabolic and Molecular Physiology, University of Nottingham, Royal Derby Hospital Centre, Derby, United Kingdom
| | - P J Atherton
- Medical Research Council-Arthritis Research UK Centre for Musculoskeletal Ageing Research, Clinical, Metabolic and Molecular Physiology, University of Nottingham, Royal Derby Hospital Centre, Derby, United Kingdom;
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17
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Lee C, Garbett A, Wilkinson DJ. A network epidemic model for online community commissioning data. Stat Comput 2017; 28:891-904. [PMID: 31983814 PMCID: PMC6953976 DOI: 10.1007/s11222-017-9770-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 07/26/2017] [Indexed: 06/10/2023]
Abstract
A statistical model assuming a preferential attachment network, which is generated by adding nodes sequentially according to a few simple rules, usually describes real-life networks better than a model assuming, for example, a Bernoulli random graph, in which any two nodes have the same probability of being connected, does. Therefore, to study the propagation of "infection" across a social network, we propose a network epidemic model by combining a stochastic epidemic model and a preferential attachment model. A simulation study based on the subsequent Markov Chain Monte Carlo algorithm reveals an identifiability issue with the model parameters. Finally, the network epidemic model is applied to a set of online commissioning data.
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Affiliation(s)
- Clement Lee
- School of Mathematics and Statistics, Newcastle University, Newcastle upon Tyne, UK
- Open Lab, Newcastle University, Newcastle upon Tyne, UK
| | | | - Darren J. Wilkinson
- School of Mathematics and Statistics, Newcastle University, Newcastle upon Tyne, UK
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18
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Bass JJ, Wilkinson DJ, Rankin D, Phillips BE, Szewczyk NJ, Smith K, Atherton PJ. An overview of technical considerations for Western blotting applications to physiological research. Scand J Med Sci Sports 2017; 27:4-25. [PMID: 27263489 PMCID: PMC5138151 DOI: 10.1111/sms.12702] [Citation(s) in RCA: 210] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/25/2016] [Indexed: 12/11/2022]
Abstract
The applications of Western/immunoblotting (WB) techniques have reached multiple layers of the scientific community and are now considered routine procedures in the field of physiology. This is none more so than in relation to skeletal muscle physiology (i.e., resolving the mechanisms underpinning adaptations to exercise). Indeed, the inclusion of WB data is now considered an essential aspect of many such physiological publications to provide mechanistic insight into regulatory processes. Despite this popularity, and due to the ubiquitous and relatively inexpensive availability of WB equipment, the quality of WB in publications and subsequent analysis and interpretation of the data can be variable, perhaps resulting in spurious conclusions. This may be due to poor laboratory technique and/or lack of comprehension of the critical steps involved in WB and what quality control procedures should be in place to ensure robust data generation. The present review aims to provide a detailed description and critique of WB procedures and technicalities, from sample collection through preparation, blotting and detection, to analysis of the data collected. We aim to provide the reader with improved expertise to critically conduct, evaluate, and troubleshoot the WB process, to produce reproducible and reliable blots.
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Affiliation(s)
- J J Bass
- MRC/ARUK Centre of Excellence for Musculoskeletal Ageing Research, School of Medicine, University of Nottingham, Derby, UK
| | - D J Wilkinson
- MRC/ARUK Centre of Excellence for Musculoskeletal Ageing Research, School of Medicine, University of Nottingham, Derby, UK
| | - D Rankin
- MRC/ARUK Centre of Excellence for Musculoskeletal Ageing Research, School of Medicine, University of Nottingham, Derby, UK
| | - B E Phillips
- MRC/ARUK Centre of Excellence for Musculoskeletal Ageing Research, School of Medicine, University of Nottingham, Derby, UK
| | - N J Szewczyk
- MRC/ARUK Centre of Excellence for Musculoskeletal Ageing Research, School of Medicine, University of Nottingham, Derby, UK
| | - K Smith
- MRC/ARUK Centre of Excellence for Musculoskeletal Ageing Research, School of Medicine, University of Nottingham, Derby, UK
| | - P J Atherton
- MRC/ARUK Centre of Excellence for Musculoskeletal Ageing Research, School of Medicine, University of Nottingham, Derby, UK
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Abstract
In this paper we consider the problem of parameter inference for Markov jump process (MJP) representations of stochastic kinetic models. Since transition probabilities are intractable for most processes of interest yet forward simulation is straightforward, Bayesian inference typically proceeds through computationally intensive methods such as (particle) MCMC. Such methods ostensibly require the ability to simulate trajectories from the conditioned jump process. When observations are highly informative, use of the forward simulator is likely to be inefficient and may even preclude an exact (simulation based) analysis. We therefore propose three methods for improving the efficiency of simulating conditioned jump processes. A conditioned hazard is derived based on an approximation to the jump process, and used to generate end-point conditioned trajectories for use inside an importance sampling algorithm. We also adapt a recently proposed sequential Monte Carlo scheme to our problem. Essentially, trajectories are reweighted at a set of intermediate time points, with more weight assigned to trajectories that are consistent with the next observation. We consider two implementations of this approach, based on two continuous approximations of the MJP. We compare these constructs for a simple tractable jump process before using them to perform inference for a Lotka-Volterra system. The best performing construct is used to infer the parameters governing a simple model of motility regulation in Bacillus subtilis.
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Abstract
Quantitative fitness analysis (QFA) is a high throughput experimental and computational methodology for measuring the growth of microbial populations. QFA screens can be used to compare the health of cell populations with and without a mutation in a query gene to infer genetic interaction strengths genomewide, examining thousands of separate genotypes. We introduce Bayesian hierarchical models of population growth rates and genetic interactions that better reflect QFA experimental design than current approaches. Our new approach models population dynamics and genetic interaction simultaneously, thereby avoiding passing information between models via a univariate fitness summary. Matching experimental structure more closely, Bayesian hierarchical approaches use data more efficiently and find new evidence for genes which interact with yeast telomeres within a published data set.
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21
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Hucka M, Bergmann FT, Dräger A, Hoops S, Keating SM, Le Novére N, Myers CJ, Olivier BG, Sahle S, Schaff JC, Smith LP, Waltemath D, Wilkinson DJ. Systems Biology Markup Language (SBML) Level 2 Version 5: Structures and Facilities for Model Definitions. J Integr Bioinform 2015; 12:271. [PMID: 26528569 PMCID: PMC5457286 DOI: 10.2390/biecoll-jib-2015-271] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Revised: 08/04/2015] [Accepted: 09/04/2015] [Indexed: 11/18/2022] Open
Abstract
Computational models can help researchers to interpret data, understand biological function, and make quantitative predictions. The Systems Biology Markup Language (SBML) is a file format for representing computational models in a declarative form that can be exchanged between different software systems. SBML is oriented towards describing biological processes of the sort common in research on a number of topics, including metabolic pathways, cell signaling pathways, and many others. By supporting SBML as an input/output format, different tools can all operate on an identical representation of a model, removing opportunities for translation errors and assuring a common starting point for analyses and simulations. This document provides the specification for Version 5 of SBML Level 2. The specification defines the data structures prescribed by SBML as well as their encoding in XML, the eXtensible Markup Language. This specification also defines validation rules that determine the validity of an SBML document, and provides many examples of models in SBML form. Other materials and software are available from the SBML project web site, http://sbml.org.
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Hucka M, Bergmann FT, Hoops S, Keating SM, Sahle S, Schaff JC, Smith LP, Wilkinson DJ. The Systems Biology Markup Language (SBML): Language Specification for Level 3 Version 1 Core. J Integr Bioinform 2015; 12:266. [PMID: 26528564 PMCID: PMC5451324 DOI: 10.2390/biecoll-jib-2015-266] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Revised: 08/03/2015] [Accepted: 09/04/2015] [Indexed: 11/18/2022] Open
Abstract
Computational models can help researchers to interpret data, understand biological function, and make quantitative predictions. The Systems Biology Markup Language (SBML) is a file format for representing computational models in a declarative form that can be exchanged between different software systems. SBML is oriented towards describing biological processes of the sort common in research on a number of topics, including metabolic pathways, cell signaling pathways, and many others. By supporting SBML as an input/output format, different tools can all operate on an identical representation of a model, removing opportunities for translation errors and assuring a common starting point for analyses and simulations. This document provides the specification for Version 1 of SBML Level 3 Core. The specification defines the data structures prescribed by SBML as well as their encoding in XML, the eXtensible Markup Language. This specification also defines validation rules that determine the validity of an SBML document, and provides many examples of models in SBML form. Other materials and software are available from the SBML project web site, http://sbml.org/.
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Green PA, Wilkinson DJ, Kenny SE. Gaps in neonatal demographics may impact on HES data: a plea for early allocation and communication of patient identifiers. Arch Dis Child Fetal Neonatal Ed 2015; 100:F467-8. [PMID: 26126842 DOI: 10.1136/archdischild-2015-308631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/09/2015] [Indexed: 11/03/2022]
Affiliation(s)
- P A Green
- University of Liverpool, Liverpool, UK Department of Paediatric Surgery, Alder Hey Children's Hospital NHS Foundation Trust, Liverpool, UK
| | - D J Wilkinson
- University of Liverpool, Liverpool, UK Department of Paediatric Surgery, Royal Manchester Children's Hospital, Manchester, UK
| | - S E Kenny
- University of Liverpool, Liverpool, UK Department of Paediatric Surgery, Alder Hey Children's Hospital NHS Foundation Trust, Liverpool, UK
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Narayanan S, Dubarry M, Lawless C, Banks AP, Wilkinson DJ, Whitehall SK, Lydall D. Quantitative Fitness Analysis Identifies exo1∆ and Other Suppressors or Enhancers of Telomere Defects in Schizosaccharomyces pombe. PLoS One 2015; 10:e0132240. [PMID: 26168240 PMCID: PMC4500466 DOI: 10.1371/journal.pone.0132240] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Accepted: 06/11/2015] [Indexed: 01/28/2023] Open
Abstract
Synthetic genetic array (SGA) has been successfully used to identify genetic interactions in S. cerevisiae and S. pombe. In S. pombe, SGA methods use either cycloheximide (C) or heat shock (HS) to select double mutants before measuring colony size as a surrogate for fitness. Quantitative Fitness Analysis (QFA) is a different method for determining fitness of microbial strains. In QFA, liquid cultures are spotted onto solid agar and growth curves determined for each spot by photography and model fitting. Here, we compared the two S. pombe SGA methods and found that the HS method was more reproducible for us. We also developed a QFA procedure for S. pombe. We used QFA to identify genetic interactions affecting two temperature sensitive, telomere associated query mutations (taz1Δ and pot1-1). We identify exo1∆ and other gene deletions as suppressors or enhancers of S. pombe telomere defects. Our study identifies known and novel gene deletions affecting the fitness of strains with telomere defects. The interactions we identify may be relevant in human cells.
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Affiliation(s)
- Siddharth Narayanan
- Institute for Cell & Molecular Biosciences, Newcastle University Medical School, Newcastle upon Tyne, NE2 4HH, United Kingdom
| | - Marion Dubarry
- Institute for Cell & Molecular Biosciences, Newcastle University Medical School, Newcastle upon Tyne, NE2 4HH, United Kingdom
| | - Conor Lawless
- Institute for Cell & Molecular Biosciences, Newcastle University Medical School, Newcastle upon Tyne, NE2 4HH, United Kingdom
| | - A. Peter Banks
- High Throughput Screening Facility, Newcastle Biomedicine, Newcastle University, Newcastle upon Tyne, NE2 4HH, United Kingdom
| | - Darren J. Wilkinson
- School of Mathematics & Statistics, Newcastle University, Newcastle upon Tyne, NE1 7RU, United Kingdom
| | - Simon K. Whitehall
- Institute for Cell & Molecular Biosciences, Newcastle University Medical School, Newcastle upon Tyne, NE2 4HH, United Kingdom
| | - David Lydall
- Institute for Cell & Molecular Biosciences, Newcastle University Medical School, Newcastle upon Tyne, NE2 4HH, United Kingdom
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Hucka M, Bergmann FT, Hoops S, Keating SM, Sahle S, Schaff JC, Smith LP, Wilkinson DJ. The Systems Biology Markup Language (SBML): Language Specification for Level 3 Version 1 Core. J Integr Bioinform 2015. [DOI: 10.1515/jib-2015-266] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Summary Computational models can help researchers to interpret data, understand biological function, and make quantitative predictions. The Systems Biology Markup Language (SBML) is a file format for representing computational models in a declarative form that can be exchanged between different software systems. SBML is oriented towards describing biological processes of the sort common in research on a number of topics, including metabolic pathways, cell signaling pathways, and many others. By supporting SBML as an input/output format, different tools can all operate on an identical representation of a model, removing opportunities for translation errors and assuring a common starting point for analyses and simulations. This document provides the specification for Version 1 of SBML Level 3 Core. The specification defines the data structures prescribed by SBML as well as their encoding in XML, the eXtensible Markup Language. This specification also defines validation rules that determine the validity of an SBML document, and provides many examples of models in SBML form. Other materials and software are available from the SBML project web site, http://sbml.org/.
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Affiliation(s)
- Michael Hucka
- 1California Institute of Technology, Pasadena, United States of America
| | - Frank T. Bergmann
- 2California Institute of Technology, Pasadena, United States of America
| | - Stefan Hoops
- 3Virginia Bioinformatics Institute, Blacksburg, United States of America
| | - Sarah M. Keating
- 2California Institute of Technology, Pasadena, United States of America
| | - Sven Sahle
- 4University of Heidelberg, Heidelberg, Germany
| | - James C. Schaff
- 5University of Connecticut, Storrs, United States of America
| | - Lucian P. Smith
- 6University of Washington, Seattle, United States of America
| | - Darren J. Wilkinson
- 7Newcastle University, Newcastle, United Kingdom of Great Britain and Northern Ireland
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Abstract
AbstractApproaches to Bayesian inference for problems with intractable likelihoods have become increasingly important in recent years. Approximate Bayesian computation (ABC) and “likelihood free” Markov chain Monte Carlo techniques are popular methods for tackling inference in these scenarios but such techniques are computationally expensive. In this paper we compare the two approaches to inference, with a particular focus on parameter inference for stochastic kinetic models, widely used in systems biology. Discrete time transition kernels for models of this type are intractable for all but the most trivial systems yet forward simulation is usually straightforward. We discuss the relative merits and drawbacks of each approach whilst considering the computational cost implications and efficiency of these techniques. In order to explore the properties of each approach we examine a range of observation regimes using two example models. We use a Lotka–Volterra predator–prey model to explore the impact of full or partial species observations using various time course observations under the assumption of known and unknown measurement error. Further investigation into the impact of observation error is then made using a Schlögl system, a test case which exhibits bi-modal state stability in some regions of parameter space.
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Jow H, Boys RJ, Wilkinson DJ. Bayesian identification of protein differential expression in multi-group isobaric labelled mass spectrometry data. Stat Appl Genet Mol Biol 2014; 13:531-51. [PMID: 25153608 DOI: 10.1515/sagmb-2012-0066] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
In this paper we develop a Bayesian statistical inference approach to the unified analysis of isobaric labelled MS/MS proteomic data across multiple experiments. An explicit probabilistic model of the log-intensity of the isobaric labels' reporter ions across multiple pre-defined groups and experiments is developed. This is then used to develop a full Bayesian statistical methodology for the identification of differentially expressed proteins, with respect to a control group, across multiple groups and experiments. This methodology is implemented and then evaluated on simulated data and on two model experimental datasets (for which the differentially expressed proteins are known) that use a TMT labelling protocol.
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Heydari J, Lawless C, Lydall DA, Wilkinson DJ. Fast Bayesian parameter estimation for stochastic logistic growth models. Biosystems 2014; 122:55-72. [PMID: 24906175 PMCID: PMC4169184 DOI: 10.1016/j.biosystems.2014.05.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Revised: 04/09/2014] [Accepted: 05/20/2014] [Indexed: 01/06/2023]
Abstract
The transition density of a stochastic, logistic population growth model with multiplicative intrinsic noise is analytically intractable. Inferring model parameter values by fitting such stochastic differential equation (SDE) models to data therefore requires relatively slow numerical simulation. Where such simulation is prohibitively slow, an alternative is to use model approximations which do have an analytically tractable transition density, enabling fast inference. We introduce two such approximations, with either multiplicative or additive intrinsic noise, each derived from the linear noise approximation (LNA) of a logistic growth SDE. After Bayesian inference we find that our fast LNA models, using Kalman filter recursion for computation of marginal likelihoods, give similar posterior distributions to slow, arbitrarily exact models. We also demonstrate that simulations from our LNA models better describe the characteristics of the stochastic logistic growth models than a related approach. Finally, we demonstrate that our LNA model with additive intrinsic noise and measurement error best describes an example set of longitudinal observations of microbial population size taken from a typical, genome-wide screening experiment.
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Brice HGT, Wilkinson DJ, Daly R, Tavernier G, Niven RM. M2 Bone mineral density changes in patients in the severe asthma clinic on oral corticosteroids. Thorax 2013. [DOI: 10.1136/thoraxjnl-2013-204457.412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Wilkinson DJ, Brice HGT, Holmes L, Fowler SJ, Niven R. S40 A comparison of asthmatic and non-asthmatic severe small airway disease. Thorax 2013. [DOI: 10.1136/thoraxjnl-2013-204457.47] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Evans MR, Grimm V, Johst K, Knuuttila T, de Langhe R, Lessells CM, Merz M, O'Malley MA, Orzack SH, Weisberg M, Wilkinson DJ, Wolkenhauer O, Benton TG. Do simple models lead to generality in ecology? Trends Ecol Evol 2013; 28:578-83. [PMID: 23827437 DOI: 10.1016/j.tree.2013.05.022] [Citation(s) in RCA: 127] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2012] [Revised: 05/26/2013] [Accepted: 05/31/2013] [Indexed: 11/26/2022]
Abstract
Modellers of biological, ecological, and environmental systems cannot take for granted the maxim 'simple means general means good'. We argue here that viewing simple models as the main way to achieve generality may be an obstacle to the progress of ecological research. We show how complex models can be both desirable and general, and how simple and complex models can be linked together to produce broad-scale and predictive understanding of biological systems.
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Affiliation(s)
- Matthew R Evans
- School of Biological and Chemical Sciences, Queen Mary, University of London, Mile End Road, London, E1 4NS, UK.
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Andrew EJ, Merchan S, Lawless C, Banks AP, Wilkinson DJ, Lydall D. Pentose phosphate pathway function affects tolerance to the G-quadruplex binder TMPyP4. PLoS One 2013; 8:e66242. [PMID: 23776642 PMCID: PMC3680382 DOI: 10.1371/journal.pone.0066242] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Accepted: 05/04/2013] [Indexed: 11/19/2022] Open
Abstract
G-quadruplexes form in guanine-rich regions of DNA and the presence of these structures at telomeres prevents the activity of telomerase in vitro. Ligands such as the cationic porphyrin TMPyP4 stabilise G-quadruplexes and are therefore under investigation for their potential use as anti-cancer drugs. In order to investigate the mechanism of action of TMPyP4 in vivo, we carried out a genome-wide screen in the budding yeast Saccharomyces cerevisiae. We found that deletion of key pentose phosphate pathway (PPP) genes increased the sensitivity of yeast to the presence of TMPyP4. The PPP plays an important role in the oxidative stress response and sensitivity to TMPyP4 also increased when genes involved in the oxidative stress response, CCS1 and YAP1, were deleted. For comparison we also report genome wide-screens using hydrogen peroxide, which causes oxidative stress, RHPS4, another G-quadruplex binder and hydroxyurea, an S phase poison. We found that a number of TMPyP4-sensitive strains are also sensitive to hydrogen peroxide in a genome-wide screen. Overall our results suggest that treatment with TMPyP4 results in light-dependent oxidative stress response in budding yeast, and that this, rather than G-quadruplex binding, is the major route to cytotoxicity. Our results have implications for the usefulness and mechanism of action of TMPyP4.
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Affiliation(s)
- Elizabeth J. Andrew
- Institute for Cell and Molecular Biosciences, Newcastle University Medical School, Newcastle Upon Tyne, United Kingdom
| | - Stephanie Merchan
- Institute for Cell and Molecular Biosciences, Newcastle University Medical School, Newcastle Upon Tyne, United Kingdom
| | - Conor Lawless
- Institute for Cell and Molecular Biosciences, Newcastle University Medical School, Newcastle Upon Tyne, United Kingdom
| | - A. Peter Banks
- Institute for Cell and Molecular Biosciences, Newcastle University Medical School, Newcastle Upon Tyne, United Kingdom
| | - Darren J. Wilkinson
- School of Mathematics and Statistics, Newcastle University, Newcastle Upon Tyne, United Kingdom
| | - David Lydall
- Institute for Cell and Molecular Biosciences, Newcastle University Medical School, Newcastle Upon Tyne, United Kingdom
- * E-mail:
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Wilkinson DJ, Hossain T, Hill DS, Phillips BE, Crossland H, Williams J, Loughna P, Churchward-Venne TA, Breen L, Phillips SM, Etheridge T, Rathmacher JA, Smith K, Szewczyk NJ, Atherton PJ. Effects of leucine and its metabolite β-hydroxy-β-methylbutyrate on human skeletal muscle protein metabolism. J Physiol 2013; 591:2911-23. [PMID: 23551944 PMCID: PMC3690694 DOI: 10.1113/jphysiol.2013.253203] [Citation(s) in RCA: 327] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Maintenance of skeletal muscle mass is contingent upon the dynamic equilibrium (fasted losses–fed gains) in protein turnover. Of all nutrients, the single amino acid leucine (Leu) possesses the most marked anabolic characteristics in acting as a trigger element for the initiation of protein synthesis. While the mechanisms by which Leu is ‘sensed’ have been the subject of great scrutiny, as a branched-chain amino acid, Leu can be catabolized within muscle, thus posing the possibility that metabolites of Leu could be involved in mediating the anabolic effect(s) of Leu. Our objective was to measure muscle protein anabolism in response to Leu and its metabolite HMB. Using [1,2-13C2]Leu and [2H5]phenylalanine tracers, and GC-MS/GC-C-IRMS we studied the effect of HMB or Leu alone on MPS (by tracer incorporation into myofibrils), and for HMB we also measured muscle proteolysis (by arteriovenous (A–V) dilution). Orally consumed 3.42 g free-acid (FA-HMB) HMB (providing 2.42 g of pure HMB) exhibited rapid bioavailability in plasma and muscle and, similarly to 3.42 g Leu, stimulated muscle protein synthesis (MPS; HMB +70%vs. Leu +110%). While HMB and Leu both increased anabolic signalling (mechanistic target of rapamycin; mTOR), this was more pronounced with Leu (i.e. p70S6K1 signalling ≤90 min vs. ≤30 min for HMB). HMB consumption also attenuated muscle protein breakdown (MPB; −57%) in an insulin-independent manner. We conclude that exogenous HMB induces acute muscle anabolism (increased MPS and reduced MPB) albeit perhaps via distinct, and/or additional mechanism(s) to Leu.
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Affiliation(s)
- D J Wilkinson
- Metabolic and Molecular Physiology Research Group, MRC-ARUK Centre of Excellence for Musculoskeletal Ageing Research, School of Graduate Entry Medicine and Health, Derby DE22 3DT, UK.
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Mc Auley MT, Wilkinson DJ, Jones JJL, Kirkwood TBL. A whole-body mathematical model of cholesterol metabolism and its age-associated dysregulation. BMC Syst Biol 2012; 6:130. [PMID: 23046614 PMCID: PMC3574035 DOI: 10.1186/1752-0509-6-130] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2012] [Accepted: 09/21/2012] [Indexed: 02/04/2023]
Abstract
BACKGROUND Global demographic changes have stimulated marked interest in the process of aging. There has been, and will continue to be, an unrelenting rise in the number of the oldest old ( >85 years of age). Together with an ageing population there comes an increase in the prevalence of age related disease. Of the diseases of ageing, cardiovascular disease (CVD) has by far the highest prevalence. It is regarded that a finely tuned lipid profile may help to prevent CVD as there is a long established relationship between alterations to lipid metabolism and CVD risk. In fact elevated plasma cholesterol, particularly Low Density Lipoprotein Cholesterol (LDL-C) has consistently stood out as a risk factor for having a cardiovascular event. Moreover it is widely acknowledged that LDL-C may rise with age in both sexes in a wide variety of groups. The aim of this work was to use a whole-body mathematical model to investigate why LDL-C rises with age, and to test the hypothesis that mechanistic changes to cholesterol absorption and LDL-C removal from the plasma are responsible for the rise. The whole-body mechanistic nature of the model differs from previous models of cholesterol metabolism which have either focused on intracellular cholesterol homeostasis or have concentrated on an isolated area of lipoprotein dynamics. The model integrates both current and previously published data relating to molecular biology, physiology, ageing and nutrition in an integrated fashion. RESULTS The model was used to test the hypothesis that alterations to the rate of cholesterol absorption and changes to the rate of removal of LDL-C from the plasma are integral to understanding why LDL-C rises with age. The model demonstrates that increasing the rate of intestinal cholesterol absorption from 50% to 80% by age 65 years can result in an increase of LDL-C by as much as 34 mg/dL in a hypothetical male subject. The model also shows that decreasing the rate of hepatic clearance of LDL-C gradually to 50% by age 65 years can result in an increase of LDL-C by as much as 116 mg/dL. CONCLUSIONS Our model clearly demonstrates that of the two putative mechanisms that have been implicated in the dysregulation of cholesterol metabolism with age, alterations to the removal rate of plasma LDL-C has the most significant impact on cholesterol metabolism and small changes to the number of hepatic LDL receptors can result in a significant rise in LDL-C. This first whole-body systems based model of cholesterol balance could potentially be used as a tool to further improve our understanding of whole-body cholesterol metabolism and its dysregulation with age. Furthermore, given further fine tuning the model may help to investigate potential dietary and lifestyle regimes that have the potential to mitigate the effects aging has on cholesterol metabolism.
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Affiliation(s)
- Mark T Mc Auley
- Campus for Ageing and Vitality, Newcastle University, Henry Wellcome Biogerontology Building, Newcastle upon Tyne, NE4 5PL, United Kingdom
| | - Darren J Wilkinson
- School of Mathematics & Statistics, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK
| | - Janette JL Jones
- Unilever R&D, Port Sunlight, Quarry Road East, Bebington, Wirral, CH63 3JW, UK
| | - Thomas BL Kirkwood
- Campus for Ageing and Vitality, Newcastle University, Henry Wellcome Biogerontology Building, Newcastle upon Tyne, NE4 5PL, United Kingdom
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Abstract
Motivation: Biological experiments give insight into networks of processes inside a cell, but are subject to error and uncertainty. However, due to the overlap between the large number of experiments reported in public databases it is possible to assess the chances of individual observations being correct. In order to do so, existing methods rely on high-quality ‘gold standard’ reference networks, but such reference networks are not always available. Results: We present a novel algorithm for computing the probability of network interactions that operates without gold standard reference data. We show that our algorithm outperforms existing gold standard-based methods. Finally, we apply the new algorithm to a large collection of genetic interaction and protein–protein interaction experiments. Availability: The integrated dataset and a reference implementation of the algorithm as a plug-in for the Ondex data integration framework are available for download at http://bio-nexus.ncl.ac.uk/projects/nogold/ Contact:darren.wilkinson@ncl.ac.uk Supplementary information:Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Jochen Weile
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
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36
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Golightly A, Wilkinson DJ. Bayesian parameter inference for stochastic biochemical network models using particle Markov chain Monte Carlo. Interface Focus 2011; 1:807-20. [PMID: 23226583 PMCID: PMC3262293 DOI: 10.1098/rsfs.2011.0047] [Citation(s) in RCA: 177] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2011] [Accepted: 09/06/2011] [Indexed: 11/12/2022] Open
Abstract
Computational systems biology is concerned with the development of detailed mechanistic models of biological processes. Such models are often stochastic and analytically intractable, containing uncertain parameters that must be estimated from time course data. In this article, we consider the task of inferring the parameters of a stochastic kinetic model defined as a Markov (jump) process. Inference for the parameters of complex nonlinear multivariate stochastic process models is a challenging problem, but we find here that algorithms based on particle Markov chain Monte Carlo turn out to be a very effective computationally intensive approach to the problem. Approximations to the inferential model based on stochastic differential equations (SDEs) are considered, as well as improvements to the inference scheme that exploit the SDE structure. We apply the methodology to a Lotka-Volterra system and a prokaryotic auto-regulatory network.
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Affiliation(s)
| | - Darren J. Wilkinson
- School of Mathematics and Statistics, Newcastle University, Merz Court, Newcastle upon Tyne NE1 7RU, UK
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Courtot M, Juty N, Knüpfer C, Waltemath D, Zhukova A, Dräger A, Dumontier M, Finney A, Golebiewski M, Hastings J, Hoops S, Keating S, Kell DB, Kerrien S, Lawson J, Lister A, Lu J, Machne R, Mendes P, Pocock M, Rodriguez N, Villeger A, Wilkinson DJ, Wimalaratne S, Laibe C, Hucka M, Le Novère N. Controlled vocabularies and semantics in systems biology. Mol Syst Biol 2011; 7:543. [PMID: 22027554 PMCID: PMC3261705 DOI: 10.1038/msb.2011.77] [Citation(s) in RCA: 214] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2011] [Accepted: 09/07/2011] [Indexed: 01/09/2023] Open
Abstract
The use of computational modeling to describe and analyze biological systems is at the heart of systems biology. This Perspective discusses the development and use of ontologies that are designed to add semantic information to computational models and simulations. The use of computational modeling to describe and analyze biological systems is at the heart of systems biology. Model structures, simulation descriptions and numerical results can be encoded in structured formats, but there is an increasing need to provide an additional semantic layer. Semantic information adds meaning to components of structured descriptions to help identify and interpret them unambiguously. Ontologies are one of the tools frequently used for this purpose. We describe here three ontologies created specifically to address the needs of the systems biology community. The Systems Biology Ontology (SBO) provides semantic information about the model components. The Kinetic Simulation Algorithm Ontology (KiSAO) supplies information about existing algorithms available for the simulation of systems biology models, their characterization and interrelationships. The Terminology for the Description of Dynamics (TEDDY) categorizes dynamical features of the simulation results and general systems behavior. The provision of semantic information extends a model's longevity and facilitates its reuse. It provides useful insight into the biology of modeled processes, and may be used to make informed decisions on subsequent simulation experiments.
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Milner P, Gillespie CS, Wilkinson DJ. Moment closure approximations for stochastic kinetic models with rational rate laws. Math Biosci 2011; 231:99-104. [PMID: 21338614 DOI: 10.1016/j.mbs.2011.02.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Revised: 01/27/2011] [Accepted: 02/11/2011] [Indexed: 11/29/2022]
Abstract
Stochastic models are often used when modelling chemical species that have low numbers of molecules. However, as these models become large, it can become computationally expensive to simulate even a single realisation of the system since even efficient simulation techniques have a high computational cost. One possible technique to approximate the stochastic system is moment closure. The moment closure approximation is used to provide analytic approximations to non-linear stochastic models. Until now, this approximation has only been applied to models with polynomial rate laws. In this paper we extend the moment closure method to cover models with rational rate laws.
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Affiliation(s)
- Peter Milner
- School of Mathematics & Statistics, Newcastle University, Newcastle upon Tyne, NE1 7RU, United Kingdom
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Wilkinson DJ, Thayyil S, Robertson NJ. Ethical and practical issues relating to the global use of therapeutic hypothermia for perinatal asphyxial encephalopathy. Arch Dis Child Fetal Neonatal Ed 2011; 96:F75-8. [PMID: 21068075 DOI: 10.1136/adc.2010.184689] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
In intensive care settings in the developed world, therapeutic hypothermia is established as a therapy for term infants with moderate to severe neonatal encephalopathy due to perinatal asphyxia. Several preclinical, pilot and clinical trials conducted in such settings over the last decade have demonstrated that this therapy is safe and effective. The greatest burden of birth asphyxia falls, however, in low- and middle-income countries; it is still unclear whether therapeutic hypothermia is safe and effective in this context. In this paper, the issues around treatments that may be proven safe and effective in the developed world and the caution needed in translating these into different settings and populations are explored. It is argued that there are strong scientific and ethical reasons supporting the conduct of rigorous, randomised controlled trials of therapeutic hypothermia in middle-income settings. There also needs to be substantial and sustainable improvements in all facets of antenatal care and in the basic level of newborn resuscitation in low income countries. This will reduce the burden of disease and allow health workers to determine rapidly which infants are most eligible for potential neuroprotection.
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Affiliation(s)
- D J Wilkinson
- The Ethox Centre, Department of Public Health and Primary Health Care, The University of Oxford, Headington, Oxford, UK.
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Lawless C, Wilkinson DJ, Young A, Addinall SG, Lydall DA. Colonyzer: automated quantification of micro-organism growth characteristics on solid agar. BMC Bioinformatics 2010; 11:287. [PMID: 20509870 PMCID: PMC2901369 DOI: 10.1186/1471-2105-11-287] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2009] [Accepted: 05/28/2010] [Indexed: 12/04/2022] Open
Abstract
Background High-throughput screens comparing growth rates of arrays of distinct micro-organism cultures on solid agar are useful, rapid methods of quantifying genetic interactions. Growth rate is an informative phenotype which can be estimated by measuring cell densities at one or more times after inoculation. Precise estimates can be made by inoculating cultures onto agar and capturing cell density frequently by plate-scanning or photography, especially throughout the exponential growth phase, and summarising growth with a simple dynamic model (e.g. the logistic growth model). In order to parametrize such a model, a robust image analysis tool capable of capturing a wide range of cell densities from plate photographs is required. Results Colonyzer is a collection of image analysis algorithms for automatic quantification of the size, granularity, colour and location of micro-organism cultures grown on solid agar. Colonyzer is uniquely sensitive to extremely low cell densities photographed after dilute liquid culture inoculation (spotting) due to image segmentation using a mixed Gaussian model for plate-wide thresholding based on pixel intensity. Colonyzer is robust to slight experimental imperfections and corrects for lighting gradients which would otherwise introduce spatial bias to cell density estimates without the need for imaging dummy plates. Colonyzer is general enough to quantify cultures growing in any rectangular array format, either growing after pinning with a dense inoculum or growing with the irregular morphology characteristic of spotted cultures. Colonyzer was developed using the open source packages: Python, RPy and the Python Imaging Library and its source code and documentation are available on SourceForge under GNU General Public License. Colonyzer is adaptable to suit specific requirements: e.g. automatic detection of cultures at irregular locations on streaked plates for robotic picking, or decreasing analysis time by disabling components such as lighting correction or colour measures. Conclusion Colonyzer can automatically quantify culture growth from large batches of captured images of microbial cultures grown during genome-wide scans over the wide range of cell densities observable after highly dilute liquid spot inoculation, as well as after more concentrated pinning inoculation. Colonyzer is open-source, allowing users to assess it, adapt it to particular research requirements and to contribute to its development.
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Affiliation(s)
- Conor Lawless
- Centre for Integrated Systems Biology of Ageing and Nutrition, Institute for Ageing and Health, Newcastle University, Campus for Ageing and Vitality, Newcastle-Upon-Tyne NE45PL, UK.
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Gillespie CS, Lei G, Boys RJ, Greenall A, Wilkinson DJ. Analysing time course microarray data using Bioconductor: a case study using yeast2 Affymetrix arrays. BMC Res Notes 2010; 3:81. [PMID: 20302631 PMCID: PMC2880961 DOI: 10.1186/1756-0500-3-81] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2009] [Accepted: 03/19/2010] [Indexed: 11/10/2022] Open
Abstract
Background Large scale microarray experiments are becoming increasingly routine, particularly those which track a number of different cell lines through time. This time-course information provides valuable insight into the dynamic mechanisms underlying the biological processes being observed. However, proper statistical analysis of time-course data requires the use of more sophisticated tools and complex statistical models. Findings Using the open source CRAN and Bioconductor repositories for R, we provide example analysis and protocol which illustrate a variety of methods that can be used to analyse time-course microarray data. In particular, we highlight how to construct appropriate contrasts to detect differentially expressed genes and how to generate plausible pathways from the data. A maintained version of the R commands can be found at http://www.mas.ncl.ac.uk/~ncsg3/microarray/. Conclusions CRAN and Bioconductor are stable repositories that provide a wide variety of appropriate statistical tools to analyse time course microarray data.
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Affiliation(s)
- Colin S Gillespie
- School of Mathematics & Statistics, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK.
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Wilkinson DJ, Kahane G, Horne M, Savulescu J. Functional neuroimaging and withdrawal of life-sustaining treatment from vegetative patients. J Med Ethics 2009; 35:508-511. [PMID: 19644010 PMCID: PMC2711351 DOI: 10.1136/jme.2008.029165] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2008] [Revised: 04/30/2009] [Accepted: 05/27/2009] [Indexed: 05/28/2023]
Abstract
Recent studies using functional magnetic resonance imaging of patients in a vegetative state have raised the possibility that such patients retain some degree of consciousness. In this paper, the ethical implications of such findings are outlined, in particular in relation to decisions about withdrawing life-sustaining treatment. It is sometimes assumed that if there is evidence of consciousness, treatment should not be withdrawn. But, paradoxically, the discovery of consciousness in very severely brain-damaged patients may provide more reason to let them die. Although functional neuroimaging is likely to play an increasing role in the assessment of patients in a vegetative state, caution is needed in the interpretation of neuroimaging findings.
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Affiliation(s)
- D J Wilkinson
- Oxford Uehiro Centre for Practical Ethics, University of Oxford, Oxford, UK.
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Abstract
In this article, we describe a Bayesian approach to the calibration of a stochastic computer model of chemical kinetics. As with many applications in the biological sciences, the data available to calibrate the model come from different sources. Furthermore, these data appear to provide somewhat conflicting information about the model parameters. We describe a modeling framework that allows us to synthesize this conflicting information and arrive at a consensus inference. In particular, we show how random effects can be incorporated into the model to account for between-individual heterogeneity that may be the source of the apparent conflict.
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Affiliation(s)
- D A Henderson
- School of Mathematics & Statistics, Newcastle University, Newcastle upon Tyne, NE1 7RU, U.K.
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McAuley MT, Kenny RA, Kirkwood TBL, Wilkinson DJ, Jones JJL, Miller VM. A mathematical model of aging-related and cortisol induced hippocampal dysfunction. BMC Neurosci 2009; 10:26. [PMID: 19320982 PMCID: PMC2680862 DOI: 10.1186/1471-2202-10-26] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2008] [Accepted: 03/25/2009] [Indexed: 11/23/2022] Open
Abstract
Background The hippocampus is essential for declarative memory synthesis and is a core pathological substrate for Alzheimer's disease (AD), the most common aging-related dementing disease. Acute increases in plasma cortisol are associated with transient hippocampal inhibition and retrograde amnesia, while chronic cortisol elevation is associated with hippocampal atrophy. Thus, cortisol levels could be monitored and managed in older people, to decrease their risk of AD type hippocampal dysfunction. We generated an in silicomodel of the chronic effects of elevated plasma cortisol on hippocampal activity and atrophy, using the systems biology mark-up language (SBML). We further challenged the model with biologically based interventions to ascertain if cortisol associated hippocampal dysfunction could be abrogated. Results The in silicoSBML model reflected the in vivoaging of the hippocampus and increased plasma cortisol and negative feedback to the hypothalamic pituitary axis. Aging induced a 12% decrease in hippocampus activity (HA), increased to 30% by acute and 40% by chronic elevations in cortisol. The biological intervention attenuated the cortisol associated decrease in HA by 2% in the acute cortisol simulation and by 8% in the chronic simulation. Conclusion Both acute and chronic elevations in cortisol secretion increased aging-associated hippocampal atrophy and a loss of HA in the model. We suggest that this first SMBL model, in tandem with in vitroand in vivostudies, may provide a backbone to further frame computational cortisol and brain aging models, which may help predict aging-related brain changes in vulnerable older people.
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Affiliation(s)
- Mark T McAuley
- Henry Wellcome Building, Biogerontology Building, Institute for Ageing and Health, Newcastle University, Newcastle Upon Tyne, England, NE4 6BE, UK.
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Henderson DA, Boys RJ, Krishnan KJ, Lawless C, Wilkinson DJ. Bayesian Emulation and Calibration of a Stochastic Computer Model of Mitochondrial DNA Deletions in Substantia Nigra Neurons. J Am Stat Assoc 2009. [DOI: 10.1198/jasa.2009.0005] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Greenall A, Lei G, Swan DC, James K, Wang L, Peters H, Wipat A, Wilkinson DJ, Lydall D. A genome wide analysis of the response to uncapped telomeres in budding yeast reveals a novel role for the NAD+ biosynthetic gene BNA2 in chromosome end protection. Genome Biol 2008; 9:R146. [PMID: 18828915 PMCID: PMC2760873 DOI: 10.1186/gb-2008-9-10-r146] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2008] [Revised: 09/23/2008] [Accepted: 10/01/2008] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Telomeres prevent the ends of eukaryotic chromosomes from being recognized as damaged DNA and protect against cancer and ageing. When telomere structure is perturbed, a co-ordinated series of events promote arrest of the cell cycle so that cells carrying damaged telomeres do not divide. In order to better understand the eukaryotic response to telomere damage, budding yeast strains harboring a temperature sensitive allele of an essential telomere capping gene (cdc13-1) were subjected to a transcriptomic study. RESULTS The genome-wide response to uncapped telomeres in yeast cdc13-1 strains, which have telomere capping defects at temperatures above approximately 27 degrees C, was determined. Telomere uncapping in cdc13-1 strains is associated with the differential expression of over 600 transcripts. Transcripts affecting responses to DNA damage and diverse environmental stresses were statistically over-represented. BNA2, required for the biosynthesis of NAD+, is highly and significantly up-regulated upon telomere uncapping in cdc13-1 strains. We find that deletion of BNA2 and NPT1, which is also involved in NAD+ synthesis, suppresses the temperature sensitivity of cdc13-1 strains, indicating that NAD+ metabolism may be linked to telomere end protection. CONCLUSIONS Our data support the hypothesis that the response to telomere uncapping is related to, but distinct from, the response to non-telomeric double-strand breaks. The induction of environmental stress responses may be a conserved feature of the eukaryotic response to telomere damage. BNA2, which is involved in NAD+ synthesis, plays previously unidentified roles in the cellular response to telomere uncapping.
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Affiliation(s)
- Amanda Greenall
- Aging Research Laboratories, Institute for Aging and Health, Newcastle University, Newcastle upon Tyne, NE4 5PL, UK
- Centre for Integrated Systems Biology of Aging and Nutrition, Newcastle University, Newcastle upon Tyne, NE4 5PL, UK
| | - Guiyuan Lei
- Centre for Integrated Systems Biology of Aging and Nutrition, Newcastle University, Newcastle upon Tyne, NE4 5PL, UK
- School of Mathematics & Statistics, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK
| | - Daniel C Swan
- Bioinformatics Support Unit, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Katherine James
- Centre for Integrated Systems Biology of Aging and Nutrition, Newcastle University, Newcastle upon Tyne, NE4 5PL, UK
- Institute of Human Genetics, International Centre for Life, Newcastle University, Newcastle upon Tyne, NE1 3BZ, UK
| | - Liming Wang
- School of Computing Science, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK
| | - Heiko Peters
- School of Computing Science, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK
| | - Anil Wipat
- Centre for Integrated Systems Biology of Aging and Nutrition, Newcastle University, Newcastle upon Tyne, NE4 5PL, UK
- Institute of Human Genetics, International Centre for Life, Newcastle University, Newcastle upon Tyne, NE1 3BZ, UK
| | - Darren J Wilkinson
- Centre for Integrated Systems Biology of Aging and Nutrition, Newcastle University, Newcastle upon Tyne, NE4 5PL, UK
- School of Mathematics & Statistics, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK
| | - David Lydall
- Aging Research Laboratories, Institute for Aging and Health, Newcastle University, Newcastle upon Tyne, NE4 5PL, UK
- Centre for Integrated Systems Biology of Aging and Nutrition, Newcastle University, Newcastle upon Tyne, NE4 5PL, UK
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
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Allen VM, Burton CH, Wilkinson DJ, Whyte RT, Harris JA, Howell M, Tinker DB. Evaluation of the performance of different cleaning treatments in reducing microbial contamination of poultry transport crates. Br Poult Sci 2008; 49:233-40. [PMID: 18568746 DOI: 10.1080/00071660802094206] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
1. The present systems for cleaning the plastic crates (drawers) used to transport live poultry to the processing plant are known to be inadequate for removing microbial contamination. 2. To investigate possible improvements, a mobile experimental rig was constructed and operated in the lairage of a poultry processing plant. The cleaning rig could simulate the conditions of commercial cleaning systems and utilise freshly emptied crates from the processing plant. 3. The aim of the study was to improve cleaning by enhancing the removal of adherent organic material on the crates and by reducing microbial contamination by at least 4 log(10) units. 4. Trials showed that the most effective treatments against Campylobacter were either (a) the combination of soaking at 55 degrees C, brushing for 90 s, washing for 15 s at 60 degrees C, followed by the application of disinfectant (Virkon S in this study) or (b) the use of ultrasound (4 kW) at 65 degrees C for 3 to 6 min, with or without mechanical brushing of crates. 5. Both of these treatments also achieved a 4 log(10) reduction or more in the counts of Enterobacteriaceae but were less effective in reducing aerobic plate counts. 6. It was noted that there was little correlation between the visual assessment of crate cleanliness and microbiological counts. 7. It was concluded that the demonstrated enhanced cleaning could contribute significantly to overall hygiene control in poultry meat production.
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Affiliation(s)
- V M Allen
- Department of Clinical Veterinary Science, University of Bristol, Langford, England.
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Abstract
OBJECTIVE The aim of this study was to measure pharyngeal pressures in preterm infants receiving high-flow nasal cannulae. STUDY DESIGN A total of 18 infants were studied (median gestational age 34 weeks, weight 1.619 kg). A catheter-tip pressure transducer was introduced into the nasopharynx. Flow was sequentially increased to a maximum of 8 l min(-1) and decreased to a minimum of 2 l min(-1). RESULT There was a strong association between pharyngeal pressure and both flow rate and infant weight (P<0.001, r (2)=0.61), but not mouth closure. This relationship could be expressed as pharyngeal pressure (cm H(2)O)=0.7+1.1 F (F=flow per kg in l min(-1) kg(-1)). CONCLUSION High-flow nasal cannulae at flow rates of 2 to 8 l min(-1) can lead to clinically significant elevations in pharyngeal pressure in preterm infants. Flow rate and weight but not mouth closure are important determinants of the pressure transmitted.
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Affiliation(s)
- D J Wilkinson
- Department of Paediatrics, Mercy Hospital for Women, Melbourne, VIC., Australia.
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Abstract
MOTIVATION Stochastic simulation is a very important tool for mathematical modelling. However, it is difficult to check the correctness of a stochastic simulator, since any two realizations from a single model will typically be different. RESULTS We have developed a test suite of stochastic models that have been solved either analytically or using numerical methods. This allows the accuracy of stochastic simulators to be tested against known results. The test suite is already being used by a number of stochastic simulator developers. AVAILABILITY The latest version of the test suite can be obtained from http://www.calibayes.ncl.ac.uk/Resources/dsmts/ and is licensed under GNU Lesser General Public License.
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Affiliation(s)
- Thomas W Evans
- Department of Mathematical Sciences, University of Liverpool, Liverpool, L69 7ZL, UK
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