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Gaffney J, Rieu R, France AK, Glynn AM, Brown K, Rooney C, Swan A, Kapacee Z, Brennan B, Dyker K, Noble D, Dixon L, Houghton F, Mandeville HC, Brennan SM, Gains J, Lim P, Thomson DD, McPartlin A, Pan S. Evaluation of Radiotherapy Dose and Survival Outcomes for Teenagers, and Young Adults with Nasopharyngeal Carcinoma in UK and Ireland. Int J Radiat Oncol Biol Phys 2023; 117:e582. [PMID: 37785767 DOI: 10.1016/j.ijrobp.2023.06.1924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
PURPOSE/OBJECTIVE(S) Nasopharyngeal carcinoma (NPC) follows a bimodal distribution with a smaller incidence peak in teenagers and young adults (TYAs). In TYAs, an over-whelming proportion are associated with Epstein-Barr virus (EBV). We have evaluated the variation in TYA NPC practice patterns across the UK and Ireland, along with survival outcomes. MATERIALS/METHODS We performed a multicenter, observational cohort study, of patients aged 13-25 years, with histologically confirmed NPC, treated between the years 2002-2022. An initial expression of interest was sent to selected centers treating H&N patients in the UK and Ireland. For analysis, patients were assessed based on total prescribed dose, with a cut off for low dose (LD) (≤61.2Gy) versus a high dose (HD)(>61.2Gy). RESULTS Ninety-five patients, from 9 centers, were eligible for inclusion. Patient demographics are shown in table1. At a median follow up of 45 months (IQR 23-111), 3-year overall survival (OS) was 98% (95% CI 93%-100%) with LD versus 91% (95% CI 83%-99%) with HD (Hazard ratio (HR) = 3.0; 95% CI 0.3-27, p = 0.3). 3-year progression free survival (PFS) was 84% (95% CI 71%-97%) with LD versus 83% (95% CI 72%-94%) with HD (HR 1.3; 95% CI 0.4-4.0, p = 0.6), and 5-year PFS was 84% (95% CI 71%-97%) with LD versus 83% (95% CI 72%-94%) with HD (HR 1.3; 95% CI 0.4-4.0, p = 0.6). Incidence of distant metastasis (DM) was 9.9%. 2 patients (6%) with T3-T4 tumors, treated with LD, had locoregional failure (LRF) compared to 1 patient (3%) treated with HD. CONCLUSION We have demonstrated excellent survival outcomes for the UK & Ireland TYA NPC patients. As the majority of cases in this age group have EBV+ NPC, with survival similar between LD and HD protocols, we propose that pediatric protocols, with lower radiotherapy doses should be considered for all TYA NPC, with the aim of reducing late effects. Additional analysis to better understand the impact of heterogeneity between both groups, including choice of protocol, induction and adjuvant treatment will follow this study. Prospective evaluation, as part of an international collaboration, is required to optimize the management strategy for this rare cohort of patients.
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Affiliation(s)
- J Gaffney
- The Christie NHS Foundation Trust, Manchester, United Kingdom
| | - R Rieu
- The Royal Marsden Hospital NHS Foundation Trust, London, United Kingdom; University College London Hospitals NHS Foundation Trust, London, United Kingdom
| | - A K France
- The Christie NHS Foundation Trust, Proton Clinical Outcomes Unit, Manchester, United Kingdom
| | - A M Glynn
- St.Luke's Radiation Oncology Network, Dublin, Ireland
| | - K Brown
- Belfast Health & Social Care Trust, Belfast, Belfast, Ireland
| | - C Rooney
- Belfast Health & Social Care Trust, Belfast, Belfast, Ireland
| | - A Swan
- Edinburgh Cancer Centre, Western General Hospital, Crewe Road South, Edinburgh, United Kingdom
| | - Z Kapacee
- Leeds Teaching Hospital NHS Trust, Leeds, UK, Leeds, United Kingdom
| | - B Brennan
- Royal Manchester Children's Hospital, Manchester, UK, Manchester, United Kingdom
| | - K Dyker
- Leeds Teaching Hospital NHS Trust, Leeds, UK, Leeds, United Kingdom
| | - D Noble
- Edinburgh Cancer Centre, Western General Hospital, Crewe Road South, Edinburgh, United Kingdom
| | - L Dixon
- Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, UK, Sheffield, United Kingdom
| | - F Houghton
- Belfast Health & Social Care Trust, Belfast, Belfast, Ireland
| | - H C Mandeville
- The Royal Marsden Hospital NHS Foundation Trust, London, United Kingdom
| | - S M Brennan
- St.Luke's Radiation Oncology Network, Dublin, Ireland
| | - J Gains
- University College London Hospitals NHS Foundation Trust, London, United Kingdom
| | - P Lim
- University College London Hospitals NHS Foundation Trust, London, United Kingdom
| | - D D Thomson
- The Christie NHS Foundation Trust, Manchester, United Kingdom
| | - A McPartlin
- Princess Margaret Cancer Centre, University Health Network, University of Toronto, Toronto, ON, Canada
| | - S Pan
- The Christie NHS Foundation Trust, Manchester, United Kingdom
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Rieu R, Prestwich RJ, Paterson C, Vohra S, Swan A, Noble D, Srinivasan D, Dixon L, Chiu K, Scott A, Mendes R, Khan S, Pilar A, Thompson A, Nutting CM, McPartlin A. A Multicenter Study of Clinician and Patient Reported Acute and Late Toxicity after Radical (Chemo)Radiotherapy for Non-Endemic Nasopharyngeal Cancer. Int J Radiat Oncol Biol Phys 2023; 117:e619. [PMID: 37785855 DOI: 10.1016/j.ijrobp.2023.06.2001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
PURPOSE/OBJECTIVE(S) Curative (chemo)radiotherapy ((CT)RT) for Nasopharyngeal cancers (NPC) achieves excellent disease control but is associated with significant late toxicities despite modern treatment delivery. Contemporary late toxicity data, including patient reported outcomes (PROs), is limited in the non-endemic population; we present a large contemporary series of toxicity outcomes and late PROs following treatment of non-endemic NPC. MATERIALS/METHODS Adult patients completing radical (CT)RT for primary NPC between February 2016 and 2020 at 7 large UK cancer centers were identified on institutional databases. Patients were excluded if they had prior head and neck cancer or prior therapeutic head and neck surgery (except neck dissection). Patients with an active other cancer were excluded from PRO assessment. Demographic, treatment, acute toxicity and outcome data were collected retrospectively from patient records. Disease-free patients were invited to complete an M.D. Anderson Dysphagia Index (MDADI) and University of Washington (UoW) Quality of Life (QoL) PROs questionnaires. RESULTS A total of 180 eligible patients were identified: 68% male, median age 54 years, 11% ≥70 years. EBV status was positive in 61% (unknown 12%). Patients had stage I (5%), II (22%), III (37%), IV (36%) disease; 95% were performance status ≤1 at baseline. Median follow-up was 31.2 months (range 0-68). A total of 54% received 70Gy in 33-35# and 43% received 65-66 Gy in 30-33#. 66% received induction and 65% received concurrent chemotherapy. 9.5% had residual disease at the first follow-up scan. Subsequent locoregional or distant recurrence occurred in 5% and 12% respectively. At last assessment, 84% patients were alive, 16% had died (of which 70% had active disease). Acute treatment toxicity included: 63% of patients required enteral support (median duration 98 days) with 9% a feeding tube at 1 year post treatment. 18% G3 dermatitis, 53% G3 mucositis. 82% requiring opioids and 40% admitted for symptom management. 90 patients completed the PROs (76% response rate) at a median of 37.8 months post treatment (Table 1). These demonstrate significant QoL detriment: 28% report significant pain, 24% require regular analgesia, and 59% report significant impact on daily activity. This was found to persist at different timepoints (not shown). CONCLUSION Excellent cancer survival outcomes are seen in a non-selected, non-endemic NPC population. However significant acute and late toxicity following radical treatment is identified which can profoundly negatively impact QoL in a relatively young cohort. This highlights the importance of ongoing efforts to reduce toxicity and supports the prospective evaluation of potential toxicity sparing technologies, such as proton beam radiotherapy.
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Affiliation(s)
- R Rieu
- The Royal Marsden Hospital NHS Foundation Trust, London, United Kingdom
| | - R J Prestwich
- Leeds Teaching Hospitals NHS Trust, Leeds, United Kingdom
| | - C Paterson
- Beatson West of Scotland Cancer Centre, Radiation Oncology Department, Glasgow, United Kingdom
| | - S Vohra
- Beaton West of Scotland Cancer Centre, Glasgow, United Kingdom
| | - A Swan
- Edinburgh Cancer Centre, Western General Hospital, Crewe Road South, Edinburgh, United Kingdom
| | - D Noble
- Edinburgh Cancer Centre, Western General Hospital, Crewe Road South, Edinburgh, United Kingdom
| | - D Srinivasan
- Western General Hospital, Edinburgh, United Kingdom
| | - L Dixon
- Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, UK, Sheffield, United Kingdom
| | - K Chiu
- Mount Vernon Cancer Centre, Department of Clinical Oncology, Northwood, United Kingdom
| | - A Scott
- Mount Vernon Hospital, Department of Clinical Oncology, Northwood, United Kingdom
| | - R Mendes
- University College London Hospital, London, United Kingdom
| | - S Khan
- University College London Hospital, London, United Kingdom
| | - A Pilar
- University College London Hospital, London, United Kingdom
| | - A Thompson
- North Middlesex University Hospital, Cambridge CB2 8AP, United Kingdom
| | - C M Nutting
- The Royal Marsden NHS Foundation Trust, London, United Kingdom
| | - A McPartlin
- Princess Margaret Cancer Centre, University Health Network, University of Toronto, Toronto, ON, Canada
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Noble D, Doyle E, Tramonti G, Law A, Sundaramurthy A, Brush J, Keanie J, Wood C, Drewell P, Keough W, McLaren D. PD-0809 4-year PSA to predict relapse risk after low dose rate brachytherapy for prostate cancer. Radiother Oncol 2021. [DOI: 10.1016/s0167-8140(21)07088-2] [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: 11/29/2022]
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Noble D, Harrison K, Shelley L, Bates A, Bailey J, Wilson M, Romanchikova M, Thomas S, Hoole A, Jadon R, Barnett G, Benson R, Jefferies S, Burnet N, Jena R. PO-0793: Does delivered OAR dose improve prediction of late toxicity in head & neck cancer patients? Radiother Oncol 2020. [DOI: 10.1016/s0167-8140(21)00810-0] [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: 11/25/2022]
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Bertholet J, Distefano G, Noble D, Bel A, VanLeeuwen R, Roggen T, Duchateau M, Thørnqvist S, Garibaldi C, Tilly N, Mollá RG, Bonaque J, Oelfke U, Aznar M, Heijmen B. PD-0311: Patterns of practice for adaptive and real-time radiation therapy part II: interfractional changes. Radiother Oncol 2020. [DOI: 10.1016/s0167-8140(21)00335-2] [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: 10/22/2022]
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Pellissier V, Schmucki R, Pe'er G, Aunins A, Brereton TM, Brotons L, Carnicer J, Chodkiewicz T, Chylarecki P, Del Moral JC, Escandell V, Evans D, Foppen R, Harpke A, Heliölä J, Herrando S, Kuussaari M, Kühn E, Lehikoinen A, Lindström Å, Moshøj CM, Musche M, Noble D, Oliver TH, Reif J, Richard D, Roy DB, Schweiger O, Settele J, Stefanescu C, Teufelbauer N, Touroult J, Trautmann S, van Strien AJ, van Swaay CAM, van Turnhout C, Vermouzek Z, Voříšek P, Jiguet F, Julliard R. Effects of Natura 2000 on nontarget bird and butterfly species based on citizen science data. Conserv Biol 2020; 34:666-676. [PMID: 31701577 DOI: 10.1111/cobi.13434] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 10/21/2019] [Accepted: 10/30/2019] [Indexed: 06/10/2023]
Abstract
The European Union's Natura 2000 (N2000) is among the largest international networks of protected areas. One of its aims is to secure the status of a predetermined set of (targeted) bird and butterfly species. However, nontarget species may also benefit from N2000. We evaluated how the terrestrial component of this network affects the abundance of nontargeted, more common bird and butterfly species based on data from long-term volunteer-based monitoring programs in 9602 sites for birds and 2001 sites for butterflies. In almost half of the 155 bird species assessed, and particularly among woodland specialists, abundance increased (slope estimates ranged from 0.101 [SD 0.042] to 3.51 [SD 1.30]) as the proportion of landscape covered by N2000 sites increased. This positive relationship existed for 27 of the 104 butterfly species (estimates ranged from 0.382 [SD 0.163] to 4.28 [SD 0.768]), although most butterflies were generalists. For most species, when land-cover covariates were accounted for these positive relationships were not evident, meaning land cover may be a determinant of positive effects of the N2000 network. The increase in abundance as N2000 coverage increased correlated with the specialization index for birds, but not for butterflies. Although the N2000 network supports high abundance of a large spectrum of species, the low number of specialist butterflies with a positive association with the N2000 network shows the need to improve the habitat quality of N2000 sites that could harbor open-land butterfly specialists. For a better understanding of the processes involved, we advocate for standardized collection of data at N2000 sites.
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Affiliation(s)
- V Pellissier
- Sorbonne Université, MNHN-CNRS-UPMC, UMR7204-CESCO, 43 rue Buffon, CP 135, Paris, 75005, France
- Section for Ecoinformatics & Biodiversity, Department of Bioscience, Aarhus University, Aarhus, DK 8000, Denmark
| | - R Schmucki
- Sorbonne Université, MNHN-CNRS-UPMC, UMR7204-CESCO, 43 rue Buffon, CP 135, Paris, 75005, France
- Centre de Synthèse et d'Analyse sur la Biodiversité, Immeuble Henri Poincaré, Domaine du Petit Arbois, Avenue Louis Philibert, Aix-en-Provence, 13857, France
- NERC Centre for Ecology & Hydrology, Wallingford, Oxfordshire, OX10 8EF, U.K
| | - G Pe'er
- German Centre for Integrative Biodiversity Research (iDiv), Halle-Jena-Leipzig, Deutscher Platz 5e, Leipzig, 04103, Germany
- Department Economics and Department Ecosystem Services, UFZ - Helmholtz Centre for Environmental Research, Permoserstr. 15, Leipzig, 04318, Germany
| | - A Aunins
- Faculty of Biology, University of Latvia, Jelgavas iela 1, Riga, LV-1004, Latvia
- Latvian Ornithological Society, Skolas iela 3, Riga, LV-1010, Latvia
| | - T M Brereton
- Butterfly Conservation, Manor Yard, East Lulworth, Wareham, Dorset, BH20 5QP, U.K
| | - L Brotons
- CSIC-CREAF, 08193 Cerdanyola del Vallès, Catalonia, Spain
- Catalan Ornithological Institute, Natural History Museum of Barcelona, Plaça Leonardo da Vinci 4-5, Barcelona, Catalonia, 08019, Spain
- InForest JRU (CEMFOR-CTFC), Solsona, Catalonia, 25280, Spain
| | - J Carnicer
- CSIC-CREAF, 08193 Cerdanyola del Vallès, Catalonia, Spain
- Department of Evolutionary Biology, Ecology, and Environmental Sciences, University of Barcelona, Catalonia, 08028, Spain
| | - T Chodkiewicz
- Museum and Institute of Zoology, Polish Academy of Sciences, Wilcza 64, Warszawa, 00-679, Poland
- Polish Society for the Protection of Birds (OTOP), ul. Odrowaza 24, Marki, 05-270, Poland
| | - P Chylarecki
- Museum and Institute of Zoology, Polish Academy of Sciences, Wilcza 64, Warszawa, 00-679, Poland
| | - J C Del Moral
- Sociedad Española de Ornitología (SEO/BirdLife), Melquíades Biencinto 34 ES-28053, Madrid, Spain
| | - V Escandell
- Sociedad Española de Ornitología (SEO/BirdLife), Melquíades Biencinto 34 ES-28053, Madrid, Spain
| | - D Evans
- European Topic Centre on Biological Diversity, 57 rue Cuvier, Paris, 75005, France
| | - R Foppen
- Sovon Dutch Centre for Field Ornithology, PO Box 6521, Nijmegen, 6503 GA, The Netherlands
| | - A Harpke
- Department of Community Ecology, UFZ - Helmholtz Centre for Environmental Research, Theodor-Lieser-Strasse 4, Halle/Saale, 06120, Germany
| | - J Heliölä
- Finnish Environment Institute (SYKE), Biodiversity Centre, P.O. Box 140, Helsinki, FI-00251, Finland
| | - S Herrando
- Catalan Ornithological Institute, Natural History Museum of Barcelona, Plaça Leonardo da Vinci 4-5, Barcelona, Catalonia, 08019, Spain
- InForest JRU (CEMFOR-CTFC), Solsona, Catalonia, 25280, Spain
| | - M Kuussaari
- Finnish Environment Institute (SYKE), Biodiversity Centre, P.O. Box 140, Helsinki, FI-00251, Finland
| | - E Kühn
- Department of Community Ecology, UFZ - Helmholtz Centre for Environmental Research, Theodor-Lieser-Strasse 4, Halle/Saale, 06120, Germany
| | - A Lehikoinen
- Finnish Museum of Natural History, University of Helsinki, P.O. Box 17, Helsinki, FI-00014, Finland
| | - Å Lindström
- Department of Biology, Biodiversity Unit, Lund University, Ecology Building, Lund, SE-223 62, Sweden
| | - C M Moshøj
- DOF-BirdLife Denmark, Vesterbrogade 140, Copenhagen V, DK-1620, Denmark
| | - M Musche
- Department of Community Ecology, UFZ - Helmholtz Centre for Environmental Research, Theodor-Lieser-Strasse 4, Halle/Saale, 06120, Germany
| | - D Noble
- BTO, The Nunnery, Thetford, Norfolk, IP24 2PU, U.K
| | - T H Oliver
- School of Biological Sciences, Harborne Building, Whiteknights Campus, University of Reading, Berkshire, RG6 6AS, U.K
| | - J Reif
- Institute for Environmental Studies, Faculty of Science, Charles University, Prague, Czech Republic
- Department of Zoology and Laboratory of Ornithology, Faculty of Science, Palacký University in Olomouc, 17. listopadu 50, Olomouc, 771 43, Czech Republic
| | - D Richard
- European Topic Centre on Biological Diversity, 57 rue Cuvier, Paris, 75005, France
| | - D B Roy
- NERC Centre for Ecology & Hydrology, Wallingford, Oxfordshire, OX10 8EF, U.K
| | - O Schweiger
- Department of Community Ecology, UFZ - Helmholtz Centre for Environmental Research, Theodor-Lieser-Strasse 4, Halle/Saale, 06120, Germany
| | - J Settele
- German Centre for Integrative Biodiversity Research (iDiv), Halle-Jena-Leipzig, Deutscher Platz 5e, Leipzig, 04103, Germany
- Department of Community Ecology, UFZ - Helmholtz Centre for Environmental Research, Theodor-Lieser-Strasse 4, Halle/Saale, 06120, Germany
| | - C Stefanescu
- CSIC-CREAF, 08193 Cerdanyola del Vallès, Catalonia, Spain
- Museu de Ciències Naturals de Granollers, Francesc Macià 51, Granollers, Catalonia, 08402, Spain
| | - N Teufelbauer
- BirdLife Austria, Museumplatz 1/10/8, Wien, A-1070, Austria
| | - J Touroult
- UMS 2006 PatriNat AFB, CNRS, MNHN; CP41, 36 rue Geoffroy Saint-Hilaire, Paris, 75005, France
| | - S Trautmann
- DDA, An den Speichern 6, Münster, 48157, Germany
| | | | - C A M van Swaay
- Dutch Butterfly Conservation and Butterfly Conservation Europe, P.O. Box 506 NL 6700 AM, Wageningen, The Netherlands
| | - C van Turnhout
- Sovon Dutch Centre for Field Ornithology, PO Box 6521, Nijmegen, 6503 GA, The Netherlands
- Department of Animal Ecology & Ecophysiology, Institute for Water and Wetland Research, Radboud University, P.O. Box 9010, Nijmegen, 6500 GL, The Netherlands
| | - Z Vermouzek
- Czech Society for Ornithology, Na Bělidle 252/34, Prague, CZ-150 00, Czech Republic
| | - P Voříšek
- Department of Zoology and Laboratory of Ornithology, Faculty of Science, Palacký University in Olomouc, 17. listopadu 50, Olomouc, 771 43, Czech Republic
- Czech Society for Ornithology, Na Bělidle 252/34, Prague, CZ-150 00, Czech Republic
| | - F Jiguet
- Sorbonne Université, MNHN-CNRS-UPMC, UMR7204-CESCO, 43 rue Buffon, CP 135, Paris, 75005, France
| | - R Julliard
- Sorbonne Université, MNHN-CNRS-UPMC, UMR7204-CESCO, 43 rue Buffon, CP 135, Paris, 75005, France
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Noble D, Harrison K, Hoole A, Wilson M, Thomas S, Bates A, Shelley L, Burnet N, Jena R. PO-0984 Univariate toxicity associations are stronger with delivered than planned dose in HNC patients. Radiother Oncol 2019. [DOI: 10.1016/s0167-8140(19)31404-5] [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: 11/27/2022]
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Wilson M, Lui J, Noble D, Royle G, Holloway S. EP-2074 Can we use Effective Depth for deformable image registration QA alongside the AAPM recommendations? Radiother Oncol 2019. [DOI: 10.1016/s0167-8140(19)32494-6] [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: 10/26/2022]
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Noble D, Harrison K, Wilson M, Hoole A, Thomas S, Burnet N, Jena R. PO-126 Predictors of dose differences to swallowing OARs in patients undergoing radiotherapy for HNC. Radiother Oncol 2019. [DOI: 10.1016/s0167-8140(19)30292-0] [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: 11/26/2022]
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Morgan C, Woodfield R, Noble D, Munang L, Rimer J. 134HOSPITAL AT HOME REDUCES EARLY READMISSION RATES FOR OLDER PEOPLE WITH EXACERBATION OF COPD. Age Ageing 2019. [DOI: 10.1093/ageing/afy208.01] [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: 11/14/2022] Open
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Houlahan JE, Currie DJ, Cottenie K, Cumming GS, Findlay CS, Fuhlendorf SD, Legendre P, Muldavin EH, Noble D, Russell R, Stevens RD, Willis TJ, Wondzell SM. Negative relationships between species richness and temporal variability are common but weak in natural systems. Ecology 2018; 99:2592-2604. [DOI: 10.1002/ecy.2514] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Revised: 08/29/2018] [Accepted: 07/05/2018] [Indexed: 01/10/2023]
Affiliation(s)
- J. E. Houlahan
- Biology Department University of New Brunswick at Saint John P.O. Box 5050 Saint John New Brunswick E2L 4L5 Canada
| | - D. J. Currie
- Ottawa Carleton Institute of Biology University Ottawa Ottawa Ontario K1N 6N5 Canada
| | - K. Cottenie
- Department of Integrative Biology University of Guelph Guelph Ontario N1G 2W1 Canada
| | - G. S. Cumming
- Department of Integrative Biology University of Guelph Guelph Ontario N1G 2W1 Canada
| | - C. S. Findlay
- ARC Centre of Excellence for Coral Reef Studies James Cook University Townsville Queensland 4811 Australia
| | - S. D. Fuhlendorf
- Department of Plant and Soil Science Oklahoma State University 368 AGH Stillwater Oklahoma 74078 USA
| | - P. Legendre
- Département de sciences biologiques Université de Montréal C.P. 6128, succursale Centre‐ville Montréal Quebec H3C 3J7 Canada
| | - E. H. Muldavin
- Biology Department University of New Mexico Albuquerque New Mexico 87131 USA
| | - D. Noble
- The National Centre for Ornithology The Nunnery British Trust for Ornithology Thetford Norfolk IP24 2PU United Kingdom
| | - R. Russell
- The Sandhill Institute for Complexity and Sustainability Grand Forks British Columbia V0H 1H0 Canada
| | - R. D. Stevens
- Department of Natural Resources Management Texas Tech University 007D Goddard Hall Lubbock Texas 79409 USA
| | - T. J. Willis
- Department of Environmental Science and Policy University of Southern Maine 309 Bailey Hall Portland Maine 04104 USA
| | - S. M. Wondzell
- Corvallis Forestry Sciences Laboratory, Pacific Northwest Research Station 3200 SW Jefferson Way Corvallis Oregon 97331 USA
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Laidley H, Noble D, Barnett G, Benson R, Jefferies S, Gemill J, Burnet N. Dose density of weekly cisplatin delivered concurrent with radiotherapy in head and neck cancer patients. Clin Oncol (R Coll Radiol) 2017. [DOI: 10.1016/j.clon.2017.04.016] [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: 10/19/2022]
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Noble D, Yeap P, Harrison K, Thomas S, Parker M, Burnet N. PO-0879: Differences between planned and delivered maximum spinal cord dose in Head &Neck cancer patients. Radiother Oncol 2017. [DOI: 10.1016/s0167-8140(17)31316-6] [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: 11/30/2022]
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Laidley H, Noble D, Barnett G, Jena R, Burnet N. EP-1040: Identifying risk factors for L’Hermitte’s syndrome after chemo-IMRT for head and neck cancer. Radiother Oncol 2017. [DOI: 10.1016/s0167-8140(17)31476-7] [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: 10/19/2022]
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Noble D, Scoffings D, Jefferies S, Williams M. OC-0560: FIESTA MRI to investigate CSF around lower cranial nerve roots; implications for radiotherapy planning. Radiother Oncol 2015. [DOI: 10.1016/s0167-8140(15)40555-9] [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: 10/23/2022]
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Abstract
While there is widespread consensus on the need both to change the prevailing research and development (R&D) paradigm and provide the community with an efficient way to personalize medicine, ecosystem stakeholders grapple with divergent conceptions about which quantitative approach should be preferred. The primary purpose of this position paper is to contrast these approaches. The second objective is to introduce a framework to bridge simulation outputs and patient outcomes, thus empowering the implementation of systems medicine.
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Affiliation(s)
| | - C Auffray
- European Institute for Systems Biology & Medicine, CNRS-UCBL-ENS, Université de Lyon France
| | - D Noble
- Department of Physiology, Anatomy & Genetics, University of Oxford Oxford, UK
| | - L Hood
- Institute for Systems Biology Seattle, Washington, USA
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Wray S, Burdyga T, Noble D, Noble K, Borysova L, Arrowsmith S. Progress in understanding electro-mechanical signalling in the myometrium. Acta Physiol (Oxf) 2015; 213:417-31. [PMID: 25439280 DOI: 10.1111/apha.12431] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Revised: 11/11/2014] [Accepted: 11/17/2014] [Indexed: 11/30/2022]
Abstract
In this review, we give a state-of-the-art account of uterine contractility, focussing on excitation-contraction (electro-mechanical) coupling (ECC). This will show how electrophysiological data and intracellular calcium measurements can be related to more modern techniques such as confocal microscopy and molecular biology, to advance our understanding of mechanical output and its modulation in the smooth muscle of the uterus, the myometrium. This new knowledge and understanding, for example concerning the role of the sarcoplasmic reticulum (SR), or stretch-activated K channels, when linked to biochemical and molecular pathways, provides a clearer and better informed basis for the development of new drugs and targets. These are urgently needed to combat dysfunctions in excitation-contraction coupling that are clinically challenging, such as preterm labour, slow to progress labours and post-partum haemorrhage. It remains the case that scientific progress still needs to be made in areas such as pacemaking and understanding interactions between the uterine environment and ion channel activity.
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Affiliation(s)
- S. Wray
- Department of Cellular and Molecular Physiology; Institute of Translational Medicine; University of Liverpool; Liverpool Women's Hospital; Liverpool UK
| | - T. Burdyga
- Department of Cellular and Molecular Physiology; Institute of Translational Medicine; University of Liverpool; Liverpool Women's Hospital; Liverpool UK
| | - D. Noble
- Department of Cellular and Molecular Physiology; Institute of Translational Medicine; University of Liverpool; Liverpool Women's Hospital; Liverpool UK
| | - K. Noble
- Department of Cellular and Molecular Physiology; Institute of Translational Medicine; University of Liverpool; Liverpool Women's Hospital; Liverpool UK
| | - L. Borysova
- Department of Cellular and Molecular Physiology; Institute of Translational Medicine; University of Liverpool; Liverpool Women's Hospital; Liverpool UK
| | - S. Arrowsmith
- Department of Cellular and Molecular Physiology; Institute of Translational Medicine; University of Liverpool; Liverpool Women's Hospital; Liverpool UK
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Shim EB, Hong SB, Lim KM, Leem CH, Youn CH, Pak HN, Earm YE, Noble D. New index for categorising cardiac reentrant wave: in silico evaluation. IET Syst Biol 2011; 5:317-23. [PMID: 22010758 DOI: 10.1049/iet-syb.2011.0019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Based on the similarity between a reentrant wave in cardiac tissue and a vortex in fluid dynamics, the authors hypothesised that a new non-dimensional index, like the Reynolds number in fluid dynamics, may play a critical role in categorising reentrant wave dynamics. Therefore the goal of the present study is to devise a new index to characterise electric wave conduction in cardiac tissue and examined whether this index can be used as a biomarker for categorising the reentrant wave pattern in cardiac tissue. Similar to the procedure used to derive the Reynolds number in fluid dynamics, the authors used a non-dimensionalisation technique to obtain the new index. Its usefulness was verified using a two-dimensional simulation model of electrical wave propagation in cardiac tissue. The simulation results showed that electrical waves in cardiac tissue move into an unstable region when the index exceeds a threshold value.
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Affiliation(s)
- E B Shim
- Department of Mechanical & Biomedical Engineering, Kangwon National University, Republic of Korea.
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Simpson W, Mutch W, Peake R, Croal B, Deans K, Rehan M, Noble D. 681 REDUCED SERUM CHOLESTEROL CONCENTRATION IN CRTITICALLY ILL PATIENTS PREDICTS REQUIREMENT FOR PARENTERAL NUTRITION. ATHEROSCLEROSIS SUPP 2011. [DOI: 10.1016/s1567-5688(11)70682-1] [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: 11/25/2022]
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Walton M, Woodward H, Van Staalduinen S, Lemer C, Greaves F, Noble D, Ellis B, Donaldson L, Barraclough B. Republished paper: The WHO patient safety curriculum guide for medical schools. Postgrad Med J 2011; 87:317-21. [DOI: 10.1136/pgmj.2009.036970rep] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [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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Walton M, Woodward H, Van Staalduinen S, Lemer C, Greaves F, Noble D, Ellis B, Donaldson L, Barraclough B. The WHO patient safety curriculum guide for medical schools. BMJ Qual Saf 2010; 19:542-6. [DOI: 10.1136/qshc.2009.036970] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [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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Abstract
1. The relation between the strength and duration of a just threshold stimulus (strength-duration curve) is analysed for an excitable membrane polarized uniformly and for an excitable cable polarized at one point.2. The effect on the strength-duration curve of non-linearity in the membrane current-voltage curve has been analysed. The strength-duration curve can be derived if the membrane current-voltage relation is independent of time. The effects of changes in the current-voltage curve with time due to the existence of a finite membrane activation time and membrane accommodation are analysed.3. The strength-duration curve for the Hodgkin-Huxley membrane equations (Hodgkin & Huxley, 1952) is compared to that of Hill's (1936) two-time constant model.4. The relation between membrane current-voltage curves and those for a point-polarized cable are derived for the steady-state condition. The cable properties tend to linearize the current-voltage curve and to sharpen the voltage threshold.5. The strength-duration curve for a point-polarized cable whose membrane obeys the Hodgkin-Huxley equations is computed numerically. There is an additional large effect on the cable strength-duration curve arising from the redistribution of charge during passage of a constant current; and the resulting strength-duration curve lies within the range of curves predicted by Hill's model.6. The conditions required for a constant charge threshold (Hodgkin & Rushton, 1946) are shown to be satisfied for short, intense stimuli applied to a cable at one point.7. The results are discussed with reference to the experimental studies available.
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Quigley M, Villamor P, Furlong K, Beavan J, Van Dissen R, Litchfield N, Stahl T, Duffy B, Bilderback E, Noble D, Barrell D, Jongens R, Cox S. Previously Unknown Fault Shakes New Zealand's South Island. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2010eo490001] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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26
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Abstract
Solutions have been computed for the point polarization of an infinite cable-like membrane obeying the equations used to reproduce the Purkinje fiber action potential (Noble, 1960, 1962a) in order to determine the conditions for initiating all-or-nothing repolarization during the action potential plateau. It was found that all-or-nothing repolarization would not be obtainable during the first half of the action potential in spite of the fact that the membrane current-voltage relations contain regions of negative conductance. At the point at which the all-or-nothing response is first obtained, the computed threshold is large and repolarization almost back to the resting potential would be required in order to initiate the response. The results are discussed in relation to the experimental evidence at present available on repolarization in heart muscle.
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Abstract
Computational models of cardiac electrophysiology are exemplar demonstrations of the integration of multiple data sets into a consistent biophysical framework. These models encapsulate physiological understanding to provide quantitative predictions of function. The combination or extension of existing models within a common framework allows integrative phenomena in larger systems to be investigated. This methodology is now routinely applied, as demonstrated by the increasing number of studies which use or extend previously developed models. In this study, we present a meta-analysis of this model re-use for two leading models of cardiac electrophysiology in the form of parameter inheritance trees, a sensitivity analysis and a comparison of the functional significance of the sodium potassium pump for defining restitution curves. These results indicate that even though the models aim to represent the same physiological system, both the sources of parameter values and the function of equivalent components are significantly different.
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Affiliation(s)
- S A Niederer
- University Computing Laboratory, University of Oxford, Oxford, UK
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Liau S, Cariati M, Noble D, Wilson C, Wishart G. An audit of local recurrence following breast conservation surgery with 5-mm target radial margin and 40-Gray breast radiotherapy for invasive breast cancer. Eur J Surg Oncol 2008. [DOI: 10.1016/j.ejso.2008.06.173] [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: 10/21/2022] Open
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29
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Ove R, Cavalieri R, Noble D. Variation of Neck Position with Image Guided Radiotherapy for Head and Neck Cancer. Int J Radiat Oncol Biol Phys 2008. [DOI: 10.1016/j.ijrobp.2008.06.1282] [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: 11/28/2022]
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O'Neil P, Noble D. An audit of perioperative staffing and complications during percutaneous and surgical tracheostomy insertion. Crit Care 2008. [PMCID: PMC4088706 DOI: 10.1186/cc6556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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31
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Noble D. Handbook of Drugs in Intensive Care: An A–Z Guide. Br J Anaesth 2007. [DOI: 10.1093/bja/aem282] [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: 11/13/2022] Open
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Houlahan JE, Currie DJ, Cottenie K, Cumming GS, Ernest SKM, Findlay CS, Fuhlendorf SD, Gaedke U, Legendre P, Magnuson JJ, McArdle BH, Muldavin EH, Noble D, Russell R, Stevens RD, Willis TJ, Woiwod IP, Wondzell SM. Compensatory dynamics are rare in natural ecological communities. Proc Natl Acad Sci U S A 2007; 104:3273-7. [PMID: 17360637 PMCID: PMC1805590 DOI: 10.1073/pnas.0603798104] [Citation(s) in RCA: 243] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2006] [Indexed: 11/18/2022] Open
Abstract
In population ecology, there has been a fundamental controversy about the relative importance of competition-driven (density-dependent) population regulation vs. abiotic influences such as temperature and precipitation. The same issue arises at the community level; are population sizes driven primarily by changes in the abundances of cooccurring competitors (i.e., compensatory dynamics), or do most species have a common response to environmental factors? Competitive interactions have had a central place in ecological theory, dating back to Gleason, Volterra, Hutchison and MacArthur, and, more recently, Hubbell's influential unified neutral theory of biodiversity and biogeography. If competitive interactions are important in driving year-to-year fluctuations in abundance, then changes in the abundance of one species should generally be accompanied by compensatory changes in the abundances of others. Thus, one necessary consequence of strong compensatory forces is that, on average, species within communities will covary negatively. Here we use measures of community covariance to assess the prevalence of negative covariance in 41 natural communities comprising different taxa at a range of spatial scales. We found that species in natural communities tended to covary positively rather than negatively, the opposite of what would be expected if compensatory dynamics were important. These findings suggest that abiotic factors such as temperature and precipitation are more important than competitive interactions in driving year-to-year fluctuations in species abundance within communities.
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Affiliation(s)
- J E Houlahan
- Department of Biology, University of New Brunswick, P.O. Box 5050, Saint John, NB, Canada E2L 4L5.
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Abstract
In pathological conditions, the exchanger may generate deleterious calcium entry. A drug that inhibited calcium entry, while still allowing transport of calcium out of the cell would then seem attractive. In fact, this is impossible for thermodynamic reasons. Inhibitors may appear to be more effective when the exchanger is operating in net calcium entry mode than in calcium exit mode. This is, however, always attributable to differences in conditions because there is strong internal sodium dependence of drug action on the exchanger. When the exchanger is operating near equilibrium, drug action is found to be equally effective in both directions.
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Affiliation(s)
- D Noble
- Department of Physiology, University of Oxford, Parks Road, Oxford, OX1 3PT, UK.
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Abstract
Late sodium current in cardiac cells is very small compared with the fast component, but as it flows throughout the action potential it may make a substantial contribution to sodium loading during each cardiac cycle. Late sodium current may contribute to triggering arrhythmia in two ways: by causing repolarisation failure (early after depolarisations); and by triggering late after depolarisations attributable to calcium oscillations in sodium-calcium overload conditions. Reduction of late sodium current would therefore be expected to have therapeutic benefits, particularly in disease states such as ischaemia in which sodium-calcium overload is a major feature.
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Affiliation(s)
- D Noble
- University Laboratory of Physiology, Parks Road, Oxford OX1 3PT, UK.
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35
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Noble D, Giles W. Cellular Na+ Homeostasis in the Mammalian Heart: Relationship to Altered Contractility, Rhythm Disturbances, and Defects in Myocyte Metabolism. J Cardiovasc Electrophysiol 2006; 17 Suppl 1:S1. [PMID: 16686663 DOI: 10.1111/j.1540-8167.2006.00438.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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36
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Noble D, Richards T, Mitchell D, Vaidya AC. Carpal tunnel syndrome following simultaneous kidney-pancreas transplant. Nephrol Dial Transplant 2005; 20:2552-3. [PMID: 16014346 DOI: 10.1093/ndt/gfh985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- D Noble
- Transplant Unit, Churchill Hospital, Oxford, UK
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Abstract
Understanding the logic of living systems requires knowledge of the mechanisms involved at the levels at which functionality is expressed. This information resides neither in the genome, nor even in the individual proteins that genes code for. No functionality is expressed at these levels. It emerges as the result of interactions between many proteins relating to each other in multiple cascades and in interaction with the cellular environment. There is therefore no alternative to copying nature and computing these interactions to determine the logic of healthy and diseased states. The rapid growth in biological databases, models of cells, tissues and organs and the development of powerful computing hardware and algorithms have made it possible to explore functionality in a quantitative manner all the way from the level of genes to the physiological function of whole organs and regulatory systems. I use models of the heart to demonstrate that we can now go all the way from individual genetic information (on mutations, for example) to exploring the consequences at a whole-organ level.
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Affiliation(s)
- D Noble
- University Laboratory of Physiology, Parks Road, Oxford OX1 3PT, UK.
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38
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Hinch R, Lindsay KA, Noble D, Rosenberg JR. The effects of static magnetic field on action potential propagation and excitation recovery in nerve. Progress in Biophysics and Molecular Biology 2005; 87:321-8. [PMID: 15556668 DOI: 10.1016/j.pbiomolbio.2004.08.013] [Citation(s) in RCA: 5] [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: 11/18/2022]
Abstract
Calculations using the Hodgkin-Huxley and one-dimensional cable equations have been performed to determine the expected sensitivity of conduction and refractoriness to changes in the time constant of sodium channel deactivation at negative potentials, as reported experimentally by Rosen (Bioelectromagnetics 24 (2003) 517) when voltage-gated sodium channels are exposed to a 125 mT static magnetic field. The predicted changes in speed of conduction and refractory period are very small.
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Affiliation(s)
- R Hinch
- Mathematical Institute, 24-29 St. Giles, Oxford, OX1 3LB, UK
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McVeigh A, Allen JI, Moore MN, Dyke P, Noble D. A carbon and nitrogen flux model of mussel digestive gland epithelial cells and their simulated response to pollutants. Mar Environ Res 2004; 58:821-827. [PMID: 15178119 DOI: 10.1016/j.marenvres.2004.03.099] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The mussel digestive gland epithelial cells provide a key interface between the organism and pollutants such as aromatic hydrocarbons. The simulation of their uptake and export mechanisms as well as an internal protein degradation pathway, and any subsequent disruption to any of them, has been undertaken. A computational model is described, which simulates the flow of carbon and nitrogen through a mussel's digestive cell. The model uses a compartmentalised view of the cell with inviolate 'pipelines' connecting each of the volume-variable partitions. Only the major physiological pathways relevant to the flow of either carbon or nitrogen or volume are modelled. Simulated response to hydrocarbon exposure is examined.
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Affiliation(s)
- A McVeigh
- Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth PL1 3DH, UK
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41
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Abstract
The experimental and clinical possibilities for studying cardiac arrhythmias in human ventricular myocardium are very limited. Therefore, the use of alternative methods such as computer simulations is of great importance. In this article we introduce a mathematical model of the action potential of human ventricular cells that, while including a high level of electrophysiological detail, is computationally cost-effective enough to be applied in large-scale spatial simulations for the study of reentrant arrhythmias. The model is based on recent experimental data on most of the major ionic currents: the fast sodium, L-type calcium, transient outward, rapid and slow delayed rectifier, and inward rectifier currents. The model includes a basic calcium dynamics, allowing for the realistic modeling of calcium transients, calcium current inactivation, and the contraction staircase. We are able to reproduce human epicardial, endocardial, and M cell action potentials and show that differences can be explained by differences in the transient outward and slow delayed rectifier currents. Our model reproduces the experimentally observed data on action potential duration restitution, which is an important characteristic for reentrant arrhythmias. The conduction velocity restitution of our model is broader than in other models and agrees better with available data. Finally, we model the dynamics of spiral wave rotation in a two-dimensional sheet of human ventricular tissue and show that the spiral wave follows a complex meandering pattern and has a period of 265 ms. We conclude that the proposed model reproduces a variety of electrophysiological behaviors and provides a basis for studies of reentrant arrhythmias in human ventricular tissue.
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Affiliation(s)
- K H W J ten Tusscher
- Department of Theoretical Biology, Utrecht University, 3584 CH Utrecht, The Netherlands.
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Markhasin VS, Solovyova O, Katsnelson LB, Protsenko Y, Kohl P, Noble D. Mechano-electric interactions in heterogeneous myocardium: development of fundamental experimental and theoretical models. Prog Biophys Mol Biol 2003; 82:207-20. [PMID: 12732280 DOI: 10.1016/s0079-6107(03)00017-8] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The heart is structurally and functionally a highly non-homogenous organ, yet its main function as a pump can only be achieved by the co-ordinated contraction of millions of ventricular cells. This apparent contradiction gives rise to the hypothesis that 'well-organised' inhomogeneity may be a pre-requisite for normal cardiac function. Here, we present a set of novel experimental and theoretical tools for the study of this concept. Heterogeneity, in its most condensed form, can be simulated using two individually controlled, mechanically interacting elements (duplex). We have developed and characterised three different types of duplexes: (i) biological duplex, consisting of two individually perfused biological samples (like thin papillary muscles or a trabeculae), (ii) virtual duplex, made-up of two interacting mathematical models of cardiac muscle, and (iii) hybrid duplex, containing a biological sample that interacts in real-time with a virtual muscle. In all three duplex types, in-series or in-parallel mechanical interaction of elements can be studied during externally isotonic, externally isometric, and auxotonic modes of contraction and relaxation. Duplex models, therefore, mimic (patho-)physiological mechano-electric interactions in heterogeneous myocardium at the multicellular level, and in an environment that allows one to control mechanical, electrical and pharmacological parameters. Results obtained using the duplex method show that: (i) contractile elements in heterogeneous myocardium are not 'independent' generators of tension/shortening, as their ino- and lusitropic characteristics change dynamically during mechanical interaction-potentially matching microscopic contractility to macroscopic demand, (ii) mechanical heterogeneity contributes differently to action potential duration (APD) changes, depending on whether mechanical coupling of elements is in-parallel or in-series, which may play a role in mechanical tuning of distant tissue regions, (iii) electro-mechanical activity of mechanically interacting contractile elements is affected by their activation sequence, which may optimise myocardial performance by smoothing intrinsic differences in APD. In conclusion, we present a novel set of tools for the experimental and theoretical investigation of cardiac mechano-electric interactions in healthy and/or diseased heterogeneous myocardium, which allows for the testing of previously inaccessible concepts.
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Affiliation(s)
- V S Markhasin
- Institute of Ecology and Genetics of Microorganisms, Ural Division of the Russian Academy of Sciences, 91, Pervomayskaya Street, 620219, Ekaterinburg, Russia.
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Bloomfield R, Noble D. Perioperative drug therapy: a neglected aspect of our practice? Minerva Anestesiol 2003; 69:325-9. [PMID: 12768160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Affiliation(s)
- R Bloomfield
- Department of Anaesthesia and Intensive Care Medicine, Aberdeen Royal Infirmary, Foresterhill, Aberdeen, UK
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44
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Abstract
Successful biological analysis requires that we understand the functional interactions between key components of cells, organs and systems, and how these interactions change in disease. This information resides neither in the genome nor in the individual proteins that genes encode. It lies at the level of protein interactions within the context of sub-cellular, cellular, tissue, organ and system structures. There is therefore no alternative to copying Nature and computing these interactions to determine the logic of healthy and diseased states. The rapid growth in biological databases, models of cells, tissues and organs, and the development of powerful computing hardware and algorithms have made it possible to explore functionality in a quantitative manner all the way from the level of genes to the physiological function of whole organs and regulatory systems. Systems biology of the 21st century is set to become highly quantitative, and therefore one of the most computer-intensive disciplines.
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Affiliation(s)
- D Noble
- University Laboratory of Physiology, Parks Road, University of Oxford, Oxford OX1 3PT, UK.
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45
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Avenell A, Noble D, Barr J, Engelhardt T. Selenium supplementation for critically ill adults. THE COCHRANE DATABASE OF SYSTEMATIC REVIEWS 2002. [DOI: 10.1002/14651858.cd003703] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Abstract
Stimulation of airway myocytes by contractile agents such as acetylcholine (ACh) activates a Ca2+-activated Cl- current (I(ClCa)) which may play a key role in calcium homeostasis of airway myocytes and hence in airway reactivity. The aim of the present study was to model I(ClCa) in airway smooth muscle cells using a computerised model previously designed for simulation of cardiac myocyte functioning. Modelling was based on a simple resistor-battery permeation model combined with multiple binding site activation by calcium. In order to validate the model, a combination of equations, used to mimic [Ca2+]i response to ACh stimulation, were incorporated into the model. The results indicate that the model developed in this article accounts for experimental recordings and electrophysiological characteristics of this current in airway smooth muscle cells, with parameter values consistent with those calculated from experimental data. Such a model may thus be used to predict I(ClCa) functioning, though additional experimental data from airway myocytes would be useful to more accurately determine some parameter values of the model.
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Affiliation(s)
- E Roux
- Laboratoire de Physiologie cellulaire respiratoire, EMI 9937, Université Victor, Segalen Bordeaux 2, France.
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47
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Abstract
The successful analysis of physiological processes requires quantitative understanding of the functional interactions between the key components of cells, organs and systems, and how these interactions change in disease states. This information does not reside in the genome, or even in the individual proteins that genes code for. There is therefore no alternative to copying nature and computing these interactions to determine the logic of healthy and diseased states. The rapid growth in biological databases, models of cells, tissues and organs, and in computing power has made it possible to explore functionality all the way from the level of genes to whole organs and systems. Examples are given of genetic modifications of the Na+ channel protein in the heart that predispose people to ventricular fibrillation, and of multiple target therapy in drug development. Complexity in biological systems also arises from tissue and organ geometry. This is illustrated using modelling of the whole heart.
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Affiliation(s)
- D Noble
- University Laboratory of Physiology, University of Oxford, UK
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48
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Abstract
INTRODUCTION Microalbuminuria is an accepted predictive marker for the early detection of renal disease and the identification of patients at high risk of developing complications of diabetes and hypertension. The Bayer Clinitek 50 is a urine chemistry point-of-care analyser for the semi-quantitative measurement of albumin and creatinine and calculation of albumin:creatinine ratio (ACR). METHOD Urine samples were obtained from 252 consecutive patients attending a city center diabetic clinic, and from 40 patients on admission to the ICU. Albumin and creatinine measurements were carried out using the Clinitek 50 and by the central laboratory. RESULTS The Clinitek 50 results agreed with the central laboratory results in 89% of the diabetic patient samples and 80% of the ICU patient samples. Excluding samples defined as normal by the Clinitek 50 (ACR<3.4 mg/mmol) would have resulted in an 80% reduction in samples sent to the lab for further quantification. The average length of stay in the group of ICU patients with normal ACR was significantly less than for those patients with an abnormal ACR (p<0.005). CONCLUSIONS The Clinitek 50 provides useful, immediate clinical information regarding the microalbuminuria status for use in the diabetic clinic setting or as a potential immediate risk management tool in intensive care.
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Affiliation(s)
- B L Croal
- Health Services Research Unit, University of Aberdeen, AB515JE, Aberdeen, UK.
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Mangoni ME, Fontanaud P, Noble PJ, Noble D, Benkemoun H, Nargeot J, Richard S. Facilitation of the L-type calcium current in rabbit sino-atrial cells: effect on cardiac automaticity. Cardiovasc Res 2000; 48:375-92. [PMID: 11090833 DOI: 10.1016/s0008-6363(00)00182-6] [Citation(s) in RCA: 21] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVE The L-type Ca(2+) current (I(Ca,L)) contributes to the generation and modulation of the pacemaker action potential (AP). We investigated facilitation of I(Ca,L) in sino-atrial cells. METHODS Facilitation was studied in regularly-beating cells isolated enzymatically from young albino rabbits (0.8-1 kg). We used the whole-cell patch-clamp technique to vary the frequency of the test depolarizations evoked at -10 mV or the conditioning diastolic membrane potential prior to the test pulse. RESULTS High frequencies (range 0.2-3.5 Hz) slowed the decay kinetics of I(Ca,L) evoked from a holding potential (HP) of -80 mV in 68% of cells resulting in a larger Ca(2+) influx during the test pulse. The amount of facilitation increased progressively between 0.2 and 3.0 Hz. When the frequency was changed from 0.1 to 1 Hz, the averaged increase in the time integral of I(Ca,L) was 27+/-7% (n=22). Application of conditioning voltages between -80 and -50 mV induced similar facilitation of I(Ca,L) in 73% of cells. The maximal increase of Ca(2+) entry occurred between -60 and -50 mV, and was on average 38+/-14% for conditioning prepulses of 5 s in duration (n=15). Numerical simulations of the pacemaker activity showed that facilitation of I(Ca,L) promotes stability of sino-atrial rate by enhancing Ca(2+) entry, thus establishing a negative feedback control against excessive heart rate slowing. CONCLUSION Facilitation of I(Ca,L) is present in rabbit sino-atrial cells. The underlying mechanism reflects modulation of I(Ca,L) decay kinetics by diastolic membrane potential and frequency of depolarization. This phenomenon may provide an important regulatory mechanism of sino-atrial automaticity.
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Affiliation(s)
- M E Mangoni
- UPR 1142 CNRS, Institut de Génétique Humaine, 141 rue de la Cardonille, Cedex 5, Montpellier, France
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Abstract
A tetrodotoxin-sensitive persistent sodium current, I(pNa), was found in guinea pig ventricular myocytes by whole-cell patch clamping. This current was characterized in cells derived from the basal left ventricular subendocardium, midmyocardium, and subepicardium. Midmyocardial cells show a statistically significant (P<0.05) smaller I(pNa) than subendocardial and subepicardial myocytes. There was no significant difference in I(pNa) current density between subepicardial and subendocardial cells. Computer modeling studies support a role of this current in the dispersion of action potential duration across the ventricular wall.
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Affiliation(s)
- B F Sakmann
- University Laboratory of Physiology, Department of Cardiovascular Medicine, John Radcliffe Hospital, Oxford, UK
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