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Bick D, Bishop J, Coleman T, Dean S, Edwards E, Frawley H, Gkini E, Hay-Smith J, Hemming K, Jones E, Oborn E, Pearson M, Salmon V, Webb S, MacArthur C. Antenatal preventative pelvic floor muscle exercise intervention led by midwives to reduce postnatal urinary incontinence (APPEAL): protocol for a feasibility and pilot cluster randomised controlled trial. Pilot Feasibility Stud 2022; 8:231. [PMID: 36273227 PMCID: PMC9588215 DOI: 10.1186/s40814-022-01185-y] [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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 10/11/2022] [Indexed: 11/11/2022] Open
Abstract
Background Antenatal pelvic floor muscle exercises (PFME) in women without prior urinary incontinence (UI) are effective in reducing postnatal UI; however, UK midwives often do not provide advice and information to women on undertaking PFME, with evidence that among women who do receive advice, many do not perform PFME. Methods The primary aim of this feasibility and pilot cluster randomised controlled trial is to provide a potential assessment of the feasibility of undertaking a future definitive trial of a midwifery-led antenatal intervention to support women to perform PFME in pregnancy and reduce UI postnatally. Community midwifery teams in participating NHS sites comprise trial clusters (n = 17). Midwives in teams randomised to the intervention will be trained on how to teach PFME to women and how to support them in undertaking PFME in pregnancy. Women whose community midwifery teams are allocated to control will receive standard antenatal care only. All pregnant women who give birth over a pre-selected sample month who receive antenatal care from participating community midwifery teams (clusters) will be sent a questionnaire at 10–12 weeks postpartum (around 1400–1500 women). Process evaluation data will include interviews with midwives to assess if the intervention could be implemented as planned. Interviews with women in both trial arms will explore their experiences of support from midwives to perform PFME during pregnancy. Data will be stored securely at the Universities of Birmingham and Exeter. Results will be disseminated through publications aimed at maternity service users, clinicians, and academics and inform a potential definitive trial of effectiveness. The West Midlands–Edgbaston Research Ethics Committee approved the study protocol. Discussion Trial outcomes will determine if criteria to progress to a definitive cluster trial are met. These include women’s questionnaire return rates, prevalence of UI, and other health outcomes as reported by women at 10–12 weeks postpartum. Progress to a definitive trial however is likely to be prevented in the UK context by new perinatal pelvic health service, although this may be possible elsewhere. Trial registration 10.1186/ISRCTN10833250. Registered 09/03/2020
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Affiliation(s)
- D Bick
- Warwick Clinical Trials Unit, Warwick Medical School, University of Warwick, Gibbet Hill, Coventry, CV4 7AL, UK.
| | - J Bishop
- University of Birmingham, Birmingham, UK
| | - T Coleman
- University of Leicester, Leicester, UK
| | - S Dean
- University of Exeter, Exeter, UK
| | - E Edwards
- Birmingham Women's and Children's Hospital, Birmingham, UK
| | - H Frawley
- University of Melbourne, Melbourne, Australia
| | - E Gkini
- University of Birmingham, Birmingham, UK
| | | | - K Hemming
- University of Birmingham, Birmingham, UK
| | - E Jones
- University of Birmingham, Birmingham, UK
| | - E Oborn
- University of Warwick, Coventry, UK
| | | | - V Salmon
- University of Exeter, Exeter, UK
| | - S Webb
- Royal College of Midwives, London, UK
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Bengough AG, Blancaflor EB, Brunner I, Comas LH, Freschet GT, Gessler A, Iversen CM, Janěcek Š, Kliměsová J, Lambers H, McCormack ML, Meier IC, Mommer L, Pagès L, Poorter H, Postma JA, Rewald B, Rose L, Roumet C, Ryser P, Salmon V, Scherer-Lorenzen M, Soudzilovskaia NA, Tharayil N, Valverde-Barrantes OJ, Weemstra M, Weigelt A, Wurzburger N, York LM, Zadworny M. Corrigendum. New Phytol 2022; 235:372. [PMID: 35478324 PMCID: PMC11062053 DOI: 10.1111/nph.18126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 03/28/2022] [Indexed: 06/14/2023]
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Euskirchen ES, Serbin SP, Carman TB, Fraterrigo JM, Genet H, Iversen CM, Salmon V, McGuire AD. Assessing dynamic vegetation model parameter uncertainty across Alaskan arctic tundra plant communities. Ecol Appl 2022; 32:e2499. [PMID: 34787932 PMCID: PMC9285828 DOI: 10.1002/eap.2499] [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] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 06/22/2021] [Accepted: 07/20/2021] [Indexed: 06/13/2023]
Abstract
As the Arctic region moves into uncharted territory under a warming climate, it is important to refine the terrestrial biosphere models (TBMs) that help us understand and predict change. One fundamental uncertainty in TBMs relates to model parameters, configuration variables internal to the model whose value can be estimated from data. We incorporate a version of the Terrestrial Ecosystem Model (TEM) developed for arctic ecosystems into the Predictive Ecosystem Analyzer (PEcAn) framework. PEcAn treats model parameters as probability distributions, estimates parameters based on a synthesis of available field data, and then quantifies both model sensitivity and uncertainty to a given parameter or suite of parameters. We examined how variation in 21 parameters in the equation for gross primary production influenced model sensitivity and uncertainty in terms of two carbon fluxes (net primary productivity and heterotrophic respiration) and two carbon (C) pools (vegetation C and soil C). We set up different parameterizations of TEM across a range of tundra types (tussock tundra, heath tundra, wet sedge tundra, and shrub tundra) in northern Alaska, along a latitudinal transect extending from the coastal plain near Utqiaġvik to the southern foothills of the Brooks Range, to the Seward Peninsula. TEM was most sensitive to parameters related to the temperature regulation of photosynthesis. Model uncertainty was mostly due to parameters related to leaf area, temperature regulation of photosynthesis, and the stomatal responses to ambient light conditions. Our analysis also showed that sensitivity and uncertainty to a given parameter varied spatially. At some sites, model sensitivity and uncertainty tended to be connected to a wider range of parameters, underlining the importance of assessing tundra community processes across environmental gradients or geographic locations. Generally, across sites, the flux of net primary productivity (NPP) and pool of vegetation C had about equal uncertainty, while heterotrophic respiration had higher uncertainty than the pool of soil C. Our study illustrates the complexity inherent in evaluating parameter uncertainty across highly heterogeneous arctic tundra plant communities. It also provides a framework for iteratively testing how newly collected field data related to key parameters may result in more effective forecasting of Arctic change.
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Affiliation(s)
| | - Shawn P. Serbin
- Terrestrial Ecosystem Science & Technology GroupEnvironmental Sciences DepartmentBrookhaven National LaboratoryUptonNew York11973USA
| | - Tobey B. Carman
- Institute of Arctic BiologyUniversity of Alaska FairbanksFairbanksAlaska99775USA
| | - Jennifer M. Fraterrigo
- Department of Natural Resources and Environmental SciencesUniversity of Illinois at Urbana‐ChampaignUrbanaIllinois61801USA
| | - Hélène Genet
- Institute of Arctic BiologyUniversity of Alaska FairbanksFairbanksAlaska99775USA
| | - Colleen M. Iversen
- Environmental Sciences Division and Climate Change Science InstituteOak Ridge National LaboratoryOak RidgeTennessee37831USA
| | - Verity Salmon
- Environmental Sciences Division and Climate Change Science InstituteOak Ridge National LaboratoryOak RidgeTennessee37831USA
| | - A. David McGuire
- Institute of Arctic BiologyUniversity of Alaska FairbanksFairbanksAlaska99775USA
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4
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Freschet GT, Pagès L, Iversen CM, Comas LH, Rewald B, Roumet C, Klimešová J, Zadworny M, Poorter H, Postma JA, Adams TS, Bagniewska‐Zadworna A, Bengough AG, Blancaflor EB, Brunner I, Cornelissen JHC, Garnier E, Gessler A, Hobbie SE, Meier IC, Mommer L, Picon‐Cochard C, Rose L, Ryser P, Scherer‐Lorenzen M, Soudzilovskaia NA, Stokes A, Sun T, Valverde‐Barrantes OJ, Weemstra M, Weigelt A, Wurzburger N, York LM, Batterman SA, Gomes de Moraes M, Janeček Š, Lambers H, Salmon V, Tharayil N, McCormack ML. A starting guide to root ecology: strengthening ecological concepts and standardising root classification, sampling, processing and trait measurements. New Phytol 2021; 232:973-1122. [PMID: 34608637 PMCID: PMC8518129 DOI: 10.1111/nph.17572] [Citation(s) in RCA: 89] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 03/22/2021] [Indexed: 05/17/2023]
Abstract
In the context of a recent massive increase in research on plant root functions and their impact on the environment, root ecologists currently face many important challenges to keep on generating cutting-edge, meaningful and integrated knowledge. Consideration of the below-ground components in plant and ecosystem studies has been consistently called for in recent decades, but methodology is disparate and sometimes inappropriate. This handbook, based on the collective effort of a large team of experts, will improve trait comparisons across studies and integration of information across databases by providing standardised methods and controlled vocabularies. It is meant to be used not only as starting point by students and scientists who desire working on below-ground ecosystems, but also by experts for consolidating and broadening their views on multiple aspects of root ecology. Beyond the classical compilation of measurement protocols, we have synthesised recommendations from the literature to provide key background knowledge useful for: (1) defining below-ground plant entities and giving keys for their meaningful dissection, classification and naming beyond the classical fine-root vs coarse-root approach; (2) considering the specificity of root research to produce sound laboratory and field data; (3) describing typical, but overlooked steps for studying roots (e.g. root handling, cleaning and storage); and (4) gathering metadata necessary for the interpretation of results and their reuse. Most importantly, all root traits have been introduced with some degree of ecological context that will be a foundation for understanding their ecological meaning, their typical use and uncertainties, and some methodological and conceptual perspectives for future research. Considering all of this, we urge readers not to solely extract protocol recommendations for trait measurements from this work, but to take a moment to read and reflect on the extensive information contained in this broader guide to root ecology, including sections I-VII and the many introductions to each section and root trait description. Finally, it is critical to understand that a major aim of this guide is to help break down barriers between the many subdisciplines of root ecology and ecophysiology, broaden researchers' views on the multiple aspects of root study and create favourable conditions for the inception of comprehensive experiments on the role of roots in plant and ecosystem functioning.
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Affiliation(s)
- Grégoire T. Freschet
- CEFEUniv Montpellier, CNRS, EPHE, IRD1919 route de MendeMontpellier34293France
- Station d’Ecologie Théorique et ExpérimentaleCNRS2 route du CNRS09200MoulisFrance
| | - Loïc Pagès
- UR 1115 PSHCentre PACA, site AgroparcINRAE84914Avignon cedex 9France
| | - Colleen M. Iversen
- Environmental Sciences Division and Climate Change Science InstituteOak Ridge National LaboratoryOak RidgeTN37831USA
| | - Louise H. Comas
- USDA‐ARS Water Management Research Unit2150 Centre Avenue, Bldg D, Suite 320Fort CollinsCO80526USA
| | - Boris Rewald
- Department of Forest and Soil SciencesUniversity of Natural Resources and Life SciencesVienna1190Austria
| | - Catherine Roumet
- CEFEUniv Montpellier, CNRS, EPHE, IRD1919 route de MendeMontpellier34293France
| | - Jitka Klimešová
- Department of Functional EcologyInstitute of Botany CASDukelska 13537901TrebonCzech Republic
| | - Marcin Zadworny
- Institute of DendrologyPolish Academy of SciencesParkowa 562‐035KórnikPoland
| | - Hendrik Poorter
- Plant Sciences (IBG‐2)Forschungszentrum Jülich GmbHD‐52425JülichGermany
- Department of Biological SciencesMacquarie UniversityNorth RydeNSW2109Australia
| | | | - Thomas S. Adams
- Department of Plant SciencesThe Pennsylvania State UniversityUniversity ParkPA16802USA
| | - Agnieszka Bagniewska‐Zadworna
- Department of General BotanyInstitute of Experimental BiologyFaculty of BiologyAdam Mickiewicz UniversityUniwersytetu Poznańskiego 661-614PoznańPoland
| | - A. Glyn Bengough
- The James Hutton InstituteInvergowrie, Dundee,DD2 5DAUK
- School of Science and EngineeringUniversity of DundeeDundee,DD1 4HNUK
| | | | - Ivano Brunner
- Forest Soils and BiogeochemistrySwiss Federal Research Institute WSLZürcherstr. 1118903BirmensdorfSwitzerland
| | - Johannes H. C. Cornelissen
- Department of Ecological ScienceFaculty of ScienceVrije Universiteit AmsterdamDe Boelelaan 1085Amsterdam1081 HVthe Netherlands
| | - Eric Garnier
- CEFEUniv Montpellier, CNRS, EPHE, IRD1919 route de MendeMontpellier34293France
| | - Arthur Gessler
- Forest DynamicsSwiss Federal Research Institute WSLZürcherstr. 1118903BirmensdorfSwitzerland
- Institute of Terrestrial EcosystemsETH Zurich8092ZurichSwitzerland
| | - Sarah E. Hobbie
- Department of Ecology, Evolution and BehaviorUniversity of MinnesotaSt PaulMN55108USA
| | - Ina C. Meier
- Functional Forest EcologyUniversity of HamburgHaidkrugsweg 122885BarsbütelGermany
| | - Liesje Mommer
- Plant Ecology and Nature Conservation GroupDepartment of Environmental SciencesWageningen University and ResearchPO Box 476700 AAWageningenthe Netherlands
| | | | - Laura Rose
- Station d’Ecologie Théorique et ExpérimentaleCNRS2 route du CNRS09200MoulisFrance
- Senckenberg Biodiversity and Climate Research Centre (BiK-F)Senckenberganlage 2560325Frankfurt am MainGermany
| | - Peter Ryser
- Laurentian University935 Ramsey Lake RoadSudburyONP3E 2C6Canada
| | | | - Nadejda A. Soudzilovskaia
- Environmental Biology DepartmentInstitute of Environmental SciencesCMLLeiden UniversityLeiden2300 RAthe Netherlands
| | - Alexia Stokes
- INRAEAMAPCIRAD, IRDCNRSUniversity of MontpellierMontpellier34000France
| | - Tao Sun
- Institute of Applied EcologyChinese Academy of SciencesShenyang110016China
| | - Oscar J. Valverde‐Barrantes
- International Center for Tropical BotanyDepartment of Biological SciencesFlorida International UniversityMiamiFL33199USA
| | - Monique Weemstra
- CEFEUniv Montpellier, CNRS, EPHE, IRD1919 route de MendeMontpellier34293France
| | - Alexandra Weigelt
- Systematic Botany and Functional BiodiversityInstitute of BiologyLeipzig UniversityJohannisallee 21-23Leipzig04103Germany
| | - Nina Wurzburger
- Odum School of EcologyUniversity of Georgia140 E. Green StreetAthensGA30602USA
| | - Larry M. York
- Biosciences Division and Center for Bioenergy InnovationOak Ridge National LaboratoryOak RidgeTN37831USA
| | - Sarah A. Batterman
- School of Geography and Priestley International Centre for ClimateUniversity of LeedsLeedsLS2 9JTUK
- Cary Institute of Ecosystem StudiesMillbrookNY12545USA
| | - Moemy Gomes de Moraes
- Department of BotanyInstitute of Biological SciencesFederal University of Goiás1974690-900Goiânia, GoiásBrazil
| | - Štěpán Janeček
- School of Biological SciencesThe University of Western Australia35 Stirling HighwayCrawley (Perth)WA 6009Australia
| | - Hans Lambers
- School of Biological SciencesThe University of Western AustraliaCrawley (Perth)WAAustralia
| | - Verity Salmon
- Environmental Sciences Division and Climate Change Science InstituteOak Ridge National LaboratoryOak RidgeTN37831USA
| | - Nishanth Tharayil
- Department of Plant and Environmental SciencesClemson UniversityClemsonSC29634USA
| | - M. Luke McCormack
- Center for Tree ScienceMorton Arboretum, 4100 Illinois Rt. 53LisleIL60532USA
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5
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Freschet GT, Pagès L, Iversen CM, Comas LH, Rewald B, Roumet C, Klimešová J, Zadworny M, Poorter H, Postma JA, Adams TS, Bagniewska-Zadworna A, Bengough AG, Blancaflor EB, Brunner I, Cornelissen JHC, Garnier E, Gessler A, Hobbie SE, Meier IC, Mommer L, Picon-Cochard C, Rose L, Ryser P, Scherer-Lorenzen M, Soudzilovskaia NA, Stokes A, Sun T, Valverde-Barrantes OJ, Weemstra M, Weigelt A, Wurzburger N, York LM, Batterman SA, Gomes de Moraes M, Janeček Š, Lambers H, Salmon V, Tharayil N, McCormack ML. A starting guide to root ecology: strengthening ecological concepts and standardising root classification, sampling, processing and trait measurements. New Phytol 2021. [PMID: 34608637 DOI: 10.1111/nph.17572.hal-03379708] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
In the context of a recent massive increase in research on plant root functions and their impact on the environment, root ecologists currently face many important challenges to keep on generating cutting-edge, meaningful and integrated knowledge. Consideration of the below-ground components in plant and ecosystem studies has been consistently called for in recent decades, but methodology is disparate and sometimes inappropriate. This handbook, based on the collective effort of a large team of experts, will improve trait comparisons across studies and integration of information across databases by providing standardised methods and controlled vocabularies. It is meant to be used not only as starting point by students and scientists who desire working on below-ground ecosystems, but also by experts for consolidating and broadening their views on multiple aspects of root ecology. Beyond the classical compilation of measurement protocols, we have synthesised recommendations from the literature to provide key background knowledge useful for: (1) defining below-ground plant entities and giving keys for their meaningful dissection, classification and naming beyond the classical fine-root vs coarse-root approach; (2) considering the specificity of root research to produce sound laboratory and field data; (3) describing typical, but overlooked steps for studying roots (e.g. root handling, cleaning and storage); and (4) gathering metadata necessary for the interpretation of results and their reuse. Most importantly, all root traits have been introduced with some degree of ecological context that will be a foundation for understanding their ecological meaning, their typical use and uncertainties, and some methodological and conceptual perspectives for future research. Considering all of this, we urge readers not to solely extract protocol recommendations for trait measurements from this work, but to take a moment to read and reflect on the extensive information contained in this broader guide to root ecology, including sections I-VII and the many introductions to each section and root trait description. Finally, it is critical to understand that a major aim of this guide is to help break down barriers between the many subdisciplines of root ecology and ecophysiology, broaden researchers' views on the multiple aspects of root study and create favourable conditions for the inception of comprehensive experiments on the role of roots in plant and ecosystem functioning.
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Affiliation(s)
- Grégoire T Freschet
- CEFE, Univ Montpellier, CNRS, EPHE, IRD, 1919 route de Mende, Montpellier, 34293, France
- Station d'Ecologie Théorique et Expérimentale, CNRS, 2 route du CNRS, 09200, Moulis, France
| | - Loïc Pagès
- UR 1115 PSH, Centre PACA, site Agroparc, INRAE, 84914, Avignon cedex 9, France
| | - Colleen M Iversen
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Louise H Comas
- USDA-ARS Water Management Research Unit, 2150 Centre Avenue, Bldg D, Suite 320, Fort Collins, CO, 80526, USA
| | - Boris Rewald
- Department of Forest and Soil Sciences, University of Natural Resources and Life Sciences, Vienna, 1190, Austria
| | - Catherine Roumet
- CEFE, Univ Montpellier, CNRS, EPHE, IRD, 1919 route de Mende, Montpellier, 34293, France
| | - Jitka Klimešová
- Department of Functional Ecology, Institute of Botany CAS, Dukelska 135, 37901, Trebon, Czech Republic
| | - Marcin Zadworny
- Institute of Dendrology, Polish Academy of Sciences, Parkowa 5, 62-035, Kórnik, Poland
| | - Hendrik Poorter
- Plant Sciences (IBG-2), Forschungszentrum Jülich GmbH, D-52425, Jülich, Germany
- Department of Biological Sciences, Macquarie University, North Ryde, NSW, 2109, Australia
| | - Johannes A Postma
- Plant Sciences (IBG-2), Forschungszentrum Jülich GmbH, D-52425, Jülich, Germany
| | - Thomas S Adams
- Department of Plant Sciences, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Agnieszka Bagniewska-Zadworna
- Department of General Botany, Institute of Experimental Biology, Faculty of Biology, Adam Mickiewicz University, Uniwersytetu Poznańskiego 6, 61-614, Poznań, Poland
| | - A Glyn Bengough
- The James Hutton Institute, Invergowrie, Dundee,, DD2 5DA, UK
- School of Science and Engineering, University of Dundee, Dundee,, DD1 4HN, UK
| | - Elison B Blancaflor
- Noble Research Institute, LLC, 2510 Sam Noble Parkway, Ardmore, OK, 73401, USA
| | - Ivano Brunner
- Forest Soils and Biogeochemistry, Swiss Federal Research Institute WSL, Zürcherstr. 111, 8903, Birmensdorf, Switzerland
| | - Johannes H C Cornelissen
- Department of Ecological Science, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1085, Amsterdam, 1081 HV, the Netherlands
| | - Eric Garnier
- CEFE, Univ Montpellier, CNRS, EPHE, IRD, 1919 route de Mende, Montpellier, 34293, France
| | - Arthur Gessler
- Forest Dynamics, Swiss Federal Research Institute WSL, Zürcherstr. 111, 8903, Birmensdorf, Switzerland
- Institute of Terrestrial Ecosystems, ETH Zurich, 8092, Zurich, Switzerland
| | - Sarah E Hobbie
- Department of Ecology, Evolution and Behavior, University of Minnesota, St Paul, MN, 55108, USA
| | - Ina C Meier
- Functional Forest Ecology, University of Hamburg, Haidkrugsweg 1, 22885, Barsbütel, Germany
| | - Liesje Mommer
- Plant Ecology and Nature Conservation Group, Department of Environmental Sciences, Wageningen University and Research, PO Box 47, 6700 AA, Wageningen, the Netherlands
| | | | - Laura Rose
- Station d'Ecologie Théorique et Expérimentale, CNRS, 2 route du CNRS, 09200, Moulis, France
- Senckenberg Biodiversity and Climate Research Centre (BiK-F), Senckenberganlage 25, 60325, Frankfurt am Main, Germany
| | - Peter Ryser
- Laurentian University, 935 Ramsey Lake Road, Sudbury, ON, P3E 2C6, Canada
| | | | - Nadejda A Soudzilovskaia
- Environmental Biology Department, Institute of Environmental Sciences, CML, Leiden University, Leiden, 2300 RA, the Netherlands
| | - Alexia Stokes
- INRAE, AMAP, CIRAD, IRD, CNRS, University of Montpellier, Montpellier, 34000, France
| | - Tao Sun
- Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China
| | - Oscar J Valverde-Barrantes
- International Center for Tropical Botany, Department of Biological Sciences, Florida International University, Miami, FL, 33199, USA
| | - Monique Weemstra
- CEFE, Univ Montpellier, CNRS, EPHE, IRD, 1919 route de Mende, Montpellier, 34293, France
| | - Alexandra Weigelt
- Systematic Botany and Functional Biodiversity, Institute of Biology, Leipzig University, Johannisallee 21-23, Leipzig, 04103, Germany
| | - Nina Wurzburger
- Odum School of Ecology, University of Georgia, 140 E. Green Street, Athens, GA, 30602, USA
| | - Larry M York
- Biosciences Division and Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Sarah A Batterman
- School of Geography and Priestley International Centre for Climate, University of Leeds, Leeds, LS2 9JT, UK
- Cary Institute of Ecosystem Studies, Millbrook, NY, 12545, USA
| | - Moemy Gomes de Moraes
- Department of Botany, Institute of Biological Sciences, Federal University of Goiás, 19, 74690-900, Goiânia, Goiás, Brazil
| | - Štěpán Janeček
- School of Biological Sciences, The University of Western Australia, 35 Stirling Highway, Crawley (Perth), WA 6009, Australia
| | - Hans Lambers
- School of Biological Sciences, The University of Western Australia, Crawley (Perth), WA, Australia
| | - Verity Salmon
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Nishanth Tharayil
- Department of Plant and Environmental Sciences, Clemson University, Clemson, SC, 29634, USA
| | - M Luke McCormack
- Center for Tree Science, Morton Arboretum, 4100 Illinois Rt. 53, Lisle, IL, 60532, USA
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Guillou-Camargo F, Ménoret V, Cantin E, Lopez O, Quintin N, Camisard E, Salmon V, Le Merdy JM, Santarelli G, Amy-Klein A, Pottie PE, Desruelle B, Chardonnet C. First industrial-grade coherent fiber link for optical frequency standard dissemination. Appl Opt 2018; 57:7203-7210. [PMID: 30182980 DOI: 10.1364/ao.57.007203] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 07/31/2018] [Indexed: 06/08/2023]
Abstract
We report on a fully bidirectional 680 km fiber link connecting two cities for which the equipment, the setup, and the characterization are managed for the first time by an industrial consortium. The link uses an active telecommunication fiber network with parallel data traffic and is equipped with three repeater laser stations and four remote double bidirectional erbium-doped fiber amplifiers. We report a short-term stability at 1 s integration time of 5.4×10-16 in 0.5 Hz bandwidth and a long-term stability of 1.7×10-20 at 65,000 s of integration time. The accuracy of the frequency transfer is evaluated as 3×10-20. No shift is observed within the statistical uncertainty. We show a continuous operation over five days with an uptime of 99.93%. This performance is comparable with the state-of-the-art coherent links established by National Metrology Institutes in Europe. It is a first step in the construction of an optical fiber network for metrology in France, which will give access to an ultrahigh performance frequency standard to a wide community of scientific users.
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Cullington HE, Bele D, Brinton JC, Cooper S, Daft M, Harding J, Hatton N, Humphries J, Lutman ME, Maddocks J, Maggs J, Millward K, O'Donoghue G, Patel S, Rajput K, Salmon V, Sear T, Speers A, Wheeler A, Wilson K. United Kingdom national paediatric bilateral project: Results of professional rating scales and parent questionnaires. Cochlear Implants Int 2017; 18:23-35. [PMID: 28098502 DOI: 10.1080/14670100.2016.1265189] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [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: 10/20/2022]
Abstract
OBJECTIVES This fourteen-centre project used professional rating scales and parent questionnaires to assess longitudinal outcomes in a large non-selected population of children receiving simultaneous and sequential bilateral cochlear implants. METHODS This was an observational non-randomized service evaluation. Data were collected at four time points: before bilateral cochlear implants or before the sequential implant, one year, two years, and three years after. The measures reported are Categories of Auditory Performance II (CAPII), Speech Intelligibility Rating (SIR), Bilateral Listening Skills Profile (BLSP) and Parent Outcome Profile (POP). RESULTS Thousand and one children aged from 8 months to almost 18 years were involved, although there were many missing data. In children receiving simultaneous implants after one, two, and three years respectively, median CAP scores were 4, 5, and 6; median SIR were 1, 2, and 3. Three years after receiving simultaneous bilateral cochlear implants, 61% of children were reported to understand conversation without lip-reading and 66% had intelligible speech if the listener concentrated hard. Auditory performance and speech intelligibility were significantly better in female children than males. Parents of children using sequential implants were generally positive about their child's well-being and behaviour since receiving the second device; those who were less positive about well-being changes also generally reported their children less willing to wear the second device. CONCLUSION Data from 78% of paediatric cochlear implant centres in the United Kingdom provide a real-world picture of outcomes of children with bilateral implants in the UK. This large reference data set can be used to identify children in the lower quartile for targeted intervention.
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Affiliation(s)
- H E Cullington
- a University of Southampton Auditory Implant Service , Southampton , UK
| | - D Bele
- a University of Southampton Auditory Implant Service , Southampton , UK
| | - J C Brinton
- a University of Southampton Auditory Implant Service , Southampton , UK
| | - S Cooper
- b St Thomas' Hospital Hearing Implant Centre , London , UK
| | - M Daft
- c Nottingham Auditory Implant Programme , Nottingham , UK
| | - J Harding
- d Cardiff Paediatric Cochlear Implant Programme , London , UK
| | - N Hatton
- e Emmeline Centre , Cambridge , UK
| | - J Humphries
- f The Oxford Cochlear Implant Programme , London , UK
| | - M E Lutman
- g Hearing and Balance Centre, University of Southampton , Southampton , UK
| | - J Maddocks
- h West of England Paediatric Hearing Implant Programme , Bristol , UK
| | - J Maggs
- i The Midlands Children's Hearing Implant Programme , Birmingham , UK
| | - K Millward
- j The Richard Ramsden Centre for Hearing Implants , Manchester , UK
| | - G O'Donoghue
- c Nottingham Auditory Implant Programme , Nottingham , UK
| | - S Patel
- k St George's Hospital Auditory Implant Service , London , UK
| | - K Rajput
- l Great Ormond Street Cochlear Implant Programme , London , UK
| | - V Salmon
- m North East Cochlear Implant Programme , Middlesbrough , UK
| | - T Sear
- n Royal National Throat Nose and Ear Cochlear Implant Programme , London , UK
| | - A Speers
- o Belfast Regional Cochlear Implant Centre , Belfast , UK
| | - A Wheeler
- n Royal National Throat Nose and Ear Cochlear Implant Programme , London , UK
| | - K Wilson
- b St Thomas' Hospital Hearing Implant Centre , London , UK
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8
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Cullington HE, Bele D, Brinton JC, Cooper S, Daft M, Harding J, Hatton N, Humphries J, Lutman ME, Maddocks J, Maggs J, Millward K, O'Donoghue G, Patel S, Rajput K, Salmon V, Sear T, Speers A, Wheeler A, Wilson K. United Kingdom national paediatric bilateral project: Demographics and results of localization and speech perception testing. Cochlear Implants Int 2016; 18:2-22. [PMID: 28010679 DOI: 10.1080/14670100.2016.1265055] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [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: 10/20/2022]
Abstract
OBJECTIVES To assess longitudinal outcomes in a large and varied population of children receiving bilateral cochlear implants both simultaneously and sequentially. METHODS This observational non-randomized service evaluation collected localization and speech recognition in noise data from simultaneously and sequentially implanted children at four time points: before bilateral cochlear implants or before the sequential implant, 1 year, 2 years, and 3 years after bilateral implants. No inclusion criteria were applied, so children with additional difficulties, cochleovestibular anomalies, varying educational placements, 23 different home languages, a full range of outcomes and varying device use were included. RESULTS 1001 children were included: 465 implanted simultaneously and 536 sequentially, representing just over 50% of children receiving bilateral implants in the UK in this period. In simultaneously implanted children the median age at implant was 2.1 years; 7% were implanted at less than 1 year of age. In sequentially implanted children the interval between implants ranged from 0.1 to 14.5 years. Children with simultaneous bilateral implants localized better than those with one implant. On average children receiving a second (sequential) cochlear implant showed improvement in localization and listening in background noise after 1 year of bilateral listening. The interval between sequential implants had no effect on localization improvement although a smaller interval gave more improvement in speech recognition in noise. Children with sequential implants on average were able to use their second device to obtain spatial release from masking after 2 years of bilateral listening. Although ranges were large, bilateral cochlear implants on average offered an improvement in localization and speech perception in noise over unilateral implants. CONCLUSION These data represent the diverse population of children with bilateral cochlear implants in the UK from 2010 to 2012. Predictions of outcomes for individual patients are not possible from these data. However, there are no indications to preclude children with long inter-implant interval having the chance of a second cochlear implant.
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Affiliation(s)
- H E Cullington
- a University of Southampton Auditory Implant Service , Highfield , Southampton SO17 1BJ , UK
| | - D Bele
- a University of Southampton Auditory Implant Service , Highfield , Southampton SO17 1BJ , UK
| | - J C Brinton
- a University of Southampton Auditory Implant Service , Highfield , Southampton SO17 1BJ , UK
| | - S Cooper
- b St. Thomas' Hospital Hearing Implant Centre , London , UK
| | - M Daft
- c Nottingham Auditory Implant Programme , Nottingham , UK
| | - J Harding
- d Cardiff Paediatric Cochlear Implant Programme , London , UK
| | - N Hatton
- e Emmeline Centre , Cambridge , UK
| | - J Humphries
- f The Oxford Cochlear Implant Programme , London , UK
| | - M E Lutman
- g Hearing and Balance Centre , University of Southampton , Southampton , UK
| | - J Maddocks
- h West of England Paediatric Hearing Implant Programme , Bristol , UK
| | - J Maggs
- i The Midlands Children's Hearing Implant Programme , Birmingham , UK
| | - K Millward
- j The Richard Ramsden Centre for Hearing Implants , Manchester , UK
| | - G O'Donoghue
- c Nottingham Auditory Implant Programme , Nottingham , UK
| | - S Patel
- k St George's Hospital Auditory Implant Service , London , UK
| | - K Rajput
- l Great Ormond Street Cochlear Implant Programme , London , UK
| | - V Salmon
- m North East Cochlear Implant Programme , Middlesbrough , UK
| | - T Sear
- n Royal National Throat Nose and Ear Cochlear Implant Programme , London , UK
| | - A Speers
- o Belfast Regional Cochlear Implant Centre , Belfast , UK
| | - A Wheeler
- n Royal National Throat Nose and Ear Cochlear Implant Programme , London , UK
| | - K Wilson
- b St. Thomas' Hospital Hearing Implant Centre , London , UK
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Salmon V, Hewlett S, Walsh N, Kirwan J, Morris M, Urban M, Cramp F. THU0639-HPR Acceptability of a Novel Physical Activity and Self-Management Intervention for Managing Fatigue in Rheumatoid Arthritis. Ann Rheum Dis 2015. [DOI: 10.1136/annrheumdis-2015-eular.2229] [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: 11/04/2022]
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Shaver GR, Rastetter EB, Salmon V, Street LE, van de Weg MJ, Rocha A, van Wijk MT, Williams M. Pan-Arctic modelling of net ecosystem exchange of CO2. Philos Trans R Soc Lond B Biol Sci 2013; 368:20120485. [PMID: 23836790 DOI: 10.1098/rstb.2012.0485] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [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: 11/12/2022] Open
Abstract
Net ecosystem exchange (NEE) of C varies greatly among Arctic ecosystems. Here, we show that approximately 75 per cent of this variation can be accounted for in a single regression model that predicts NEE as a function of leaf area index (LAI), air temperature and photosynthetically active radiation (PAR). The model was developed in concert with a survey of the light response of NEE in Arctic and subarctic tundras in Alaska, Greenland, Svalbard and Sweden. Model parametrizations based on data collected in one part of the Arctic can be used to predict NEE in other parts of the Arctic with accuracy similar to that of predictions based on data collected in the same site where NEE is predicted. The principal requirement for the dataset is that it should contain a sufficiently wide range of measurements of NEE at both high and low values of LAI, air temperature and PAR, to properly constrain the estimates of model parameters. Canopy N content can also be substituted for leaf area in predicting NEE, with equal or greater accuracy, but substitution of soil temperature for air temperature does not improve predictions. Overall, the results suggest a remarkable convergence in regulation of NEE in diverse ecosystem types throughout the Arctic.
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Affiliation(s)
- G R Shaver
- Ecosystems Center, Marine Biological Laboratory, Woods Hole, MA, USA.
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11
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Sallmann FR, Baveye-Descamps S, Pattus F, Salmon V, Branza N, Spik G, Legrand D. Porins OmpC and PhoE of Escherichia coli as specific cell-surface targets of human lactoferrin. Binding characteristics and biological effects. J Biol Chem 1999; 274:16107-14. [PMID: 10347162 DOI: 10.1074/jbc.274.23.16107] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The binding of lactoferrin, an iron-binding glycoprotein found in secretions and leukocytes, to the outer membrane of Gram-negative bacteria is a prerequisite to exert its bactericidal activity. It was proposed that porins, in addition to lipopolysaccharides, are responsible for this binding. We studied the interactions of human lactoferrin with the three major porins of Escherichia coli OmpC, OmpF, and PhoE. Binding experiments were performed on both purified porins and porin-deficient E. coli K12 isogenic mutants. We determined that lactoferrin binds to the purified native OmpC or PhoE trimer with molar ratios of 1.9 +/- 0.4 and 1.8 +/- 0.3 and Kd values of 39 +/- 18 and 103 +/- 15 nM, respectively, but not to OmpF. Furthermore, preferential binding of lactoferrin was observed on strains that express either OmpC or PhoE. It was also demonstrated that residues 1-5, 28-34, and 39-42 of lactoferrin interact with porins. Based on sequence comparisons, the involvement of lactoferrin amino acid residues and porin loops in the interactions is discussed. The relationships between binding and antibacterial activity of the protein were studied using E. coli mutants and planar lipid bilayers. Electrophysiological studies revealed that lactoferrin can act as a blocking agent for OmpC but not for PhoE or OmpF. However, a total inhibition of the growth was only observed for the PhoE-expressing strain (minimal inhibitory concentration of lactoferrin was 2.4 mg/ml). These data support the proposal that the antibacterial activity of lactoferrin may depend, at least in part, on its ability to bind to porins, thus modifying the stability and/or the permeability of the bacterial outer membrane.
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Affiliation(s)
- F R Sallmann
- Laboratoire de Chimie Biologique et Unité Mixte de Recherche 8576 du CNRS, Université des Sciences et Technologies de Lille, 59655 Villeneuve d'Ascq Cedex, France
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12
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Lannuzel A, Salmon V, Mével G, Malpote E, Rabier R, Caparros-Lefebvre D. [Epidemiology of stroke in Guadeloupe and role of sickle cell trait]. Rev Neurol (Paris) 1999; 155:351-6. [PMID: 10427598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
Sickle cell disease (homozygotes SS) is known as a risk factor for both ischemic and hemorrhagic stroke, but heterozygotes AS seem to be spared. We carried out a retrospective study to assess the main risk factors and the influence of hemoglobin abnormalities on stroke in Guadeloupe. The percentages of AS, AC, and AA on 295 patients admitted for stroke were compared to the prevalence obtained on 72,000 newborn babies. Ischemic, hemorrhagic stroke and stroke complications represented respectively 83 p. 100, 10 p. 100 and 7 p. 100. Seventy one per 100 of patients had hypertension and 19 p. 100 had an association of diabetes and hypertension. The percentage of heterozygotes AS was significantly lower in the group with ischemic stroke (4 p. 100) in comparison with controls (8.5 p. 100), while AS were more represented in hemorrhagic stroke (16 p. 100). The risk of hemorrhagic stroke was 10 fold higher in AS patients admitted for stroke and the risk of ischemic stroke was reduced by 15 fold. These data suggest that the sickle cell trait could be associated to red cell and/or endothelial specificities which could prevent for ischemic stroke. The influence of AS heterozygote on the occurrence of stroke needs to be examined in a longitudinal, prospective study.
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Affiliation(s)
- A Lannuzel
- Service de Neurologie, Centre Hospitalier Universitaire de Pointe-à-Pitre, Faculté Antilles-Guyane, Guadeloupe.
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Legrand D, van Berkel PH, Salmon V, van Veen HA, Slomianny MC, Nuijens JH, Spik G. Role of the first N-terminal basic cluster of human lactoferrin (R2R3R4R5) in the interactions with the Jurkat human lymphoblastic T-cells. Adv Exp Med Biol 1998; 443:49-55. [PMID: 9781342 DOI: 10.1007/978-1-4757-9068-9_6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
We previously characterized a receptor of Mr 105,000 for human lactoferrin (hLf) on Jurkat human lymphoblastic T-cells. To delineate the role of R2R3R4R5 of hLf in the interaction with cells, we studied the binding of hLf variants obtained either by tryptic proteolysis (hLf-2N, hLF-3N and hLf-4N) or by mutagenesis (rhLf-5N). Consecutive removal of N-terminal arginine residues from hLf progressively increased the binding affinity but decreased the number of binding sites on the cells. The binding parameters of bovine Lf and native hLf did not differ, whereas the binding parameters of murine Lf resembled those of rhLf-5N. Culture of Jurkat cells in the presence of chlorate, which inhibits sulfation, reduced the number of binding sites for both native hLf and hLf-3N but not for rhLf-5N indicating that the hLf binding sites include sulfated molecules. The results suggest that the interaction of hLf with about 80,000 binding sites per Jurkat cell, mainly sulfated molecules, is dependent on R2R3R4, but not on R5. Interaction with about 20,000 binding sites per cell, presumably the hLf receptor, does not require the first N-terminal basic cluster of hLf. We conclude that the deletion of R2-R5 from hLf may serve to modulate the nature of its binding to cells and thereby its effects on cellular physiology.
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Affiliation(s)
- D Legrand
- Laboratoire de Chimie Biologique, Université des Sciences et Technologies de Lille, Villeneuve d'Ascq, France
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Salmon V, Legrand D, Slomianny MC, el Yazidi I, Spik G, Gruber V, Bournat P, Olagnier B, Mison D, Theisen M, Mérot B. Production of human lactoferrin in transgenic tobacco plants. Protein Expr Purif 1998; 13:127-35. [PMID: 9631525 DOI: 10.1006/prep.1998.0886] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Production and characterization of human lactoferrin (hLf) in transgenic tobacco is reported. We have engineered two constructs containing either the native signal peptide from human lactoferrin or the signal peptide from sweet potato sporamin fused to human lactoferrin encoding cDNA. N-terminal sequences of rhLf purified from tobacco were identical to Lf from human milk for both constructs. The tobacco rhLf presents a molecular mass closely identical to native protein. Overall sugar composition shows the presence of plant specific xylose while sialic acid is absent. Binding parameters of the recombinant molecule to both Jurkat lymphoblastic T-cells or HT29-18-C1 enterocytes are similar to those of human lactoferrin isolated from milk.
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Affiliation(s)
- V Salmon
- Laboratoire de Chimie Biologique, Centre National de la Recherche Scientifique No. 111, Université des Sciences et Technologies de Lille, Villeneuve d'Ascq, France
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15
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Elass-Rochard E, Legrand D, Salmon V, Roseanu A, Trif M, Tobias PS, Mazurier J, Spik G. Lactoferrin inhibits the endotoxin interaction with CD14 by competition with the lipopolysaccharide-binding protein. Infect Immun 1998; 66:486-91. [PMID: 9453600 PMCID: PMC107932 DOI: 10.1128/iai.66.2.486-491.1998] [Citation(s) in RCA: 131] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Human lactoferrin (hLf), a glycoprotein released from neutrophil granules during inflammation, and the lipopolysaccharide (LPS)-binding protein (LBP), an acute-phase serum protein, are known to bind to the lipid A of LPS. The LPS-binding sites are located in the N-terminal regions of both proteins, at amino acid residues 28 to 34 of hLf and 91 to 108 of LBP. Both of these proteins modulate endotoxin activities, but they possess biologically antagonistic properties. In this study, we have investigated the competition between hLf and recombinant human LBP (rhLBP) for the binding of Escherichia coli 055:B5 LPS to the differentiated monocytic THP-1 cell line. Our studies revealed that hLf prevented the rhLBP-mediated binding of LPS to the CD14 receptor on cells. Maximal inhibition of LPS-cell interactions by hLf was raised when both hLf and rhLBP were simultaneously added to LPS or when hLf and LPS were mixed with cells 30 min prior to the incubation with rhLBP. However, when hLf was added 30 min after the interaction of rhLBP with LPS, the binding of the rhLPS-LBP complex to CD14 could not be reversed. These observations indicate that hLf competes with rhLBP for the LPS binding and therefore interferes with the interaction of LPS with CD14. Furthermore, experiments involving competitive binding of the rhLBP-LPS complex to cells with two recombinant mutated hLfs show that in addition to residues 28 to 34, another basic cluster which contains residues 1 to 5 of hLf competes for the binding to LPS. Basic sequences homologous to residues 28 to 34 of hLf were evidenced on LPS-binding proteins such as LBP, bactericidal/permeability-increasing protein, and Limulus anti-LPS factor.
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Affiliation(s)
- E Elass-Rochard
- Unité Mixte de Recherche de CNRS no. 111, Université des Sciences et Technologies de Lille, Villeneuve d'Ascq, France
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Legrand D, van Berkel PH, Salmon V, van Veen HA, Slomianny MC, Nuijens JH, Spik G. The N-terminal Arg2, Arg3 and Arg4 of human lactoferrin interact with sulphated molecules but not with the receptor present on Jurkat human lymphoblastic T-cells. Biochem J 1997; 327 ( Pt 3):841-6. [PMID: 9581564 PMCID: PMC1218865 DOI: 10.1042/bj3270841] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
We previously characterized a 105 kDa receptor for human lactoferrin (hLf) on Jurkat human lymphoblastic T-cells. To delineate the role of the basic cluster Arg2-Arg3-Arg4-Arg5 of hLf in the interaction with Jurkat cells, we isolated N-terminally deleted hLf species of molecular mass 80 kDa lacking two, three or four N-terminal residues (hLf-2N, hLf-3N and hLf-4N) from native hLf that had been treated with trypsin. Native hLf bound to 102000 sites on Jurkat cells with a dissociation constant (Kd) of 70 nM. Consecutive removal of N-terminal arginine residues from hLf progressively increased the binding affinity but decreased the number of binding sites on the cells. A recombinant hLF mutant lacking the first five N-terminal residues (rhLf-5N) bound to 17000 sites with a Kd of 12 nM. The binding parameters of bovine lactoferrin (Lf) and native hLf did not significantly differ, whereas the binding parameters of murine Lf (8000 sites; Kd 30 nM) resembled those of rhLf-5N. Culture of Jurkat cells in the presence of chlorate, which inhibits sulphation, decreased the number of binding sites for both native hLf and hLf-3N but not for rhLf-5N, indicating that the hLf-binding sites include sulphated molecules. We propose that the interaction of hLf with a large number of binding sites (approx. 80000 per cell) on Jurkat cells is dependent on Arg2-Arg3-Arg4, but not on Arg5. Interaction with approx. 20000 binding sites per cell, presumably the hLf receptor, does not require the first N-terminal basic cluster of hLf. Moreover, the affinity of hLf for the latter binding site is enhanced approx. 6-fold after removal of the first basic cluster. Thus N-terminal proteolysis of hLf in vivo might serve to modulate the nature of its binding to cells and thereby its effects on cellular physiology.
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Affiliation(s)
- D Legrand
- Laboratoire de Chimie Biologique et Unité Mixte de Recherche no. 111 du Centre National de la Recherche Scientifique, Université des Sciences et Technologies de Lille, 59655 Villeneuve d'Ascq cedex, France
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Salmon V, Legrand D, Georges B, Slomianny MC, Coddeville B, Spik G. Characterization of human lactoferrin produced in the baculovirus expression system. Protein Expr Purif 1997; 9:203-10. [PMID: 9056485 DOI: 10.1006/prep.1996.0687] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Lactoferrin, an iron-binding 80-kDa glycoprotein, is a major component of human milk whose structure is now well defined. The binding site of lactoferrin to the membrane receptor of lymphocyte has been located in the region 4-52, but the amino acids directly involved in the interaction have not been identified yet. To gain further insights into the structure-function relationships of the lactoferrin binding site, we first expressed the cDNA encoding human lactoferrin in the lepidoptera Spodoptera frugiperda cells (Sf9) using a recombinant baculovirus. The selected transformant secreted and N-glycosylated protein of 78 kDa which was immunoprecipitated by specific anti-lactoferrin antibodies. To confirm the structure and the function of the recombinant lactoferrin, the protein was purified by ion-exchange chromatography and its physical, biochemical, and biological properties were compared with those of the native protein. In particular, the N-terminal amino acid sequence and the iron-binding stability as a function of pH, of both proteins, were identical. The main difference concerns the glycosylation which leads to glycans of lower molecular masses as detected by the electrophoretic mobility of lactoferrin after N-glycosidase F treatment and matrix-assisted laser desorption ionization/time-of-flight mass spectrometry. Despite the different glycosylation features, the recombinant lactoferrin retained the binding property to the Jurkat human lymphoblastic T-cell line of the native lactoferrin. On the basis of these analyses, production of protein mutants generated by site-directed mutagenesis is now in process.
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Affiliation(s)
- V Salmon
- Laboratoire de Chimie Biologique, Centre National de la Recherche Scientifique, Université des Sciences et Technologies de Lille, Villeneuve, France
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Elass-Rochard E, Roseanu A, Legrand D, Trif M, Salmon V, Motas C, Montreuil J, Spik G. Lactoferrin-lipopolysaccharide interaction: involvement of the 28-34 loop region of human lactoferrin in the high-affinity binding to Escherichia coli 055B5 lipopolysaccharide. Biochem J 1995; 312 ( Pt 3):839-45. [PMID: 8554529 PMCID: PMC1136191 DOI: 10.1042/bj3120839] [Citation(s) in RCA: 173] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The ability of lactoferrin (Lf), an iron-binding glycoprotein that is also called lactotransferrin, to bind lipopolysaccharide (LPS) may be relevant to some of its biological properties. A knowledge of the LPS-binding site on Lf may help to explain the mechanism of its involvement in host defence. Our report reveals the presence of two Escherichia coli 055B5 LPS-binding sites on human Lf (hLf): a high-affinity binding site (Kd 3.6 +/- 1 nM) and a low-affinity binding site (Kd 390 +/- 20 nM). Bovine Lf (bLf), which shares about 70% amino acid sequence identity with hLf, exhibits the same behaviour towards LPS. Like hLf, bLf also contains a low- and a high-affinity LPS-binding site. The Kd value (4.5 +/- 2 nM) corresponding to the high-affinity binding site is similar to that obtained for hLf. Different LPS-binding sites for human serum transferrin have been suggested, as this protein, which is known to bind bacterial endotoxin, produced only 12% inhibition of hLf-LPS interaction. Binding and competitive binding experiments performed with the N-tryptic fragment (residues 4-283), the C-tryptic fragment (residues 284-692) and the N2-glycopeptide (residues 91-255) isolated from hLf have demonstrated that the high-affinity binding site is located in the N-terminal domain I of hLf, and the low-affinity binding site is present in the C-terminal lobe. The inhibition of hLf-LPS interaction by a synthetic octadecapeptide corresponding to residues 20-37 of hLf and lactoferricin B (residues 17-41), a proteolytic fragment from bLf, revealed the importance of the 28-34 loop region of hLf and the homologous region of bLf for LPS binding. Direct evidence that this amino acid sequence is involved in the high-affinity binding to LPS was demonstrated by assays carried out with EGS-loop hLf, a recombinant hLf mutated at residues 28-34.
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Affiliation(s)
- E Elass-Rochard
- Laboratoire de Chimie Biologique, Unité Mixte de Recherche du CNRS no. 111, Université des Sciences et Technologies de Lille, Villeneuve d'Ascq, France
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Legrand D, Salmon V, Coddeville B, Benaissa M, Plancke Y, Spik G. Structural determination of two N-linked glycans isolated from recombinant human lactoferrin expressed in BHK cells. FEBS Lett 1995; 365:57-60. [PMID: 7774715 DOI: 10.1016/0014-5793(95)00441-b] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A full-length cDNA coding for human lactoferrin was isolated from a mammary gland library and the recombinant protein was expressed in BHK cells as described by Stowell K. M. et al. [1991, Biochem. J. 276, 349-355]. Two N-linked glycans from purified recombinant lactoferrin were released by hydrazinolysis and analyzed by 400-MHz 1H-NMR spectroscopy. The identified structures corresponded to N-acetyllactosaminic biantennary glycans and were alpha-2,3-disialylated forms (80%) or alpha-2,3-monosialylated (20%) forms. Moreover, 70% of total glycans were alpha-1,6-fucosylated at the GlcNAc residue linked to asparagine. In regard to its glycan moiety, the recombinant glycoprotein is close to native lactoferrins from milk or leucocytes but shows specific structural features which should be taken into account prior to in vivo and in vitro biological studies.
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Affiliation(s)
- D Legrand
- Laboratoire de Chimie Biologique, UMR CNRS n.111, Université des Sciences et Technologies de Lille, Villeneuve d'Ascq, France
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Breuil J, Podglajen I, Collatz E, Salmon V, Dublanchet A. Selection in vitro de Bacteroides fragilis resistant a l'imipeneme (Imp-R). Med Mal Infect 1990. [DOI: 10.1016/s0399-077x(05)80076-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Salmon V. Ultrasonics. Theory and Application. G. L. Gooberman. Hart, New York, 1969. xii + 212 pp., illus. $12. Science 1969. [DOI: 10.1126/science.166.3910.1262] [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: 11/02/2022]
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