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Chauhan A, Lalor T, Watson S, Adams D, Farrah TE, Anand A, Kimmitt R, Mills NL, Webb DJ, Dhaun N, Kalla R, Adams A, Vatn S, Bonfliglio F, Nimmo E, Kennedy N, Ventham N, Vatn M, Ricanek P, Halfvarson J, Soderhollm J, Pierik M, Torkvist L, Gomollon F, Gut I, Jahnsen J, Satsangi J, Body R, Almashali M, McDowell G, Taylor P, Lacey A, Rees A, Dayan C, Lazarus J, Nelson S, Okosieme O, Corcoran D, Young R, Ciadella P, McCartney P, Bajrangee A, Hennigan B, Collison D, Carrick D, Shaukat A, Good R, Watkins S, McEntegart M, Watt J, Welsh P, Sattar N, McConnachie A, Oldroyd K, Berry C, Parks T, Auckland K, Mentzer AJ, Kado J, Mirabel MM, Kauwe JK, Robson KJ, Mittal B, Steer AC, Hill AVS, Akbar M, Forrester M, Virlan AT, Gilmour A, Wallace C, Paterson C, Reid D, Siebert S, Porter D, Liversidge J, McInnes I, Goodyear C, Athwal V, Pritchett J, Zaitoun A, Irving W, Guha IN, Hanley NA, Hanley KP, Briggs T, Reynolds J, Rice G, Bondet V, Bruce E, Crow Y, Duffy D, Parker B, Bruce I, Martin K, Pritchett J, Aoibheann Mullan M, Llewellyn J, Athwal V, Zeef L, Farrow S, Streuli C, Henderson N, Friedman S, Hanley N, Hanley KP. Scientific Business Abstracts of the 112th Annual Meeting of the Association of Physicians of Great Britain and Ireland. QJM 2018; 111:920-924. [PMID: 31222346 DOI: 10.1093/qjmed/hcy193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
| | - T Lalor
- From the University of Birmingham
| | - S Watson
- From the University of Birmingham
| | - D Adams
- From the University of Birmingham
| | - T E Farrah
- From the University/British Heart Foundation Centre of Research Excellence, University of Edinburgh
| | - A Anand
- From the University/British Heart Foundation Centre of Research Excellence, University of Edinburgh
| | - R Kimmitt
- From the University/British Heart Foundation Centre of Research Excellence, University of Edinburgh
| | - N L Mills
- From the University/British Heart Foundation Centre of Research Excellence, University of Edinburgh
| | - D J Webb
- From the University/British Heart Foundation Centre of Research Excellence, University of Edinburgh
| | - N Dhaun
- From the University/British Heart Foundation Centre of Research Excellence, University of Edinburgh
| | - R Kalla
- From the University of Edinburgh
| | - A Adams
- From the University of Edinburgh
| | - S Vatn
- Akerhshus University Hospital
| | | | - E Nimmo
- From the University of Edinburgh
| | | | | | | | | | | | | | - M Pierik
- Maastricht University Medical Centre
| | | | | | | | | | | | - R Body
- From the University of Manchester
| | - M Almashali
- Manchester University Hospitals Foundation NHS Trust
| | | | | | | | - A Rees
- From the Cardiff University
| | | | | | | | | | - D Corcoran
- From the British Heart Foundation (BHF), Glasgow Cardiovascular Research Centre, University of Glasgow
| | - R Young
- Robertson Centre for Biostatistics, University of Glasgow
| | - P Ciadella
- West of Scotland Heart and Lung Centre, Golden Jubilee National Hospital
| | - P McCartney
- From the British Heart Foundation (BHF), Glasgow Cardiovascular Research Centre, University of Glasgow
| | - A Bajrangee
- West of Scotland Heart and Lung Centre, Golden Jubilee National Hospital
| | - B Hennigan
- West of Scotland Heart and Lung Centre, Golden Jubilee National Hospital
| | - D Collison
- West of Scotland Heart and Lung Centre, Golden Jubilee National Hospital
| | - D Carrick
- West of Scotland Heart and Lung Centre, Golden Jubilee National Hospital
| | - A Shaukat
- West of Scotland Heart and Lung Centre, Golden Jubilee National Hospital
| | - R Good
- West of Scotland Heart and Lung Centre, Golden Jubilee National Hospital
| | - S Watkins
- West of Scotland Heart and Lung Centre, Golden Jubilee National Hospital
| | - M McEntegart
- West of Scotland Heart and Lung Centre, Golden Jubilee National Hospital
| | - J Watt
- West of Scotland Heart and Lung Centre, Golden Jubilee National Hospital
| | - P Welsh
- From the British Heart Foundation (BHF), Glasgow Cardiovascular Research Centre, University of Glasgow
| | - N Sattar
- From the British Heart Foundation (BHF), Glasgow Cardiovascular Research Centre, University of Glasgow
| | - A McConnachie
- Robertson Centre for Biostatistics, University of Glasgow
| | - K Oldroyd
- West of Scotland Heart and Lung Centre, Golden Jubilee National Hospital
| | - C Berry
- From the British Heart Foundation (BHF), Glasgow Cardiovascular Research Centre, University of Glasgow
| | - T Parks
- From the London School of Hygiene and Tropical Medicine
- University of Oxford
| | | | | | - J Kado
- Fiji Islands Ministry of Health and Medical Services
| | - M M Mirabel
- French National Institute of Health and Medical Research
| | | | | | - B Mittal
- Babasaheb Bhimrao Ambedkar University
| | - A C Steer
- Murdoch Children's Research Institute
| | | | - M Akbar
- From the Institute of Infection, Immunity & Inflammation, University of Glasgow
| | - M Forrester
- Division of Applied Medicine, School of Medicine and Dentistry, University of Aberdeen
| | - A T Virlan
- From the Institute of Infection, Immunity & Inflammation, University of Glasgow
| | - A Gilmour
- From the Institute of Infection, Immunity & Inflammation, University of Glasgow
| | - C Wallace
- Division of Applied Medicine, School of Medicine and Dentistry, University of Aberdeen
| | - C Paterson
- From the Institute of Infection, Immunity & Inflammation, University of Glasgow
| | - D Reid
- Division of Applied Medicine, School of Medicine and Dentistry, University of Aberdeen
| | - S Siebert
- From the Institute of Infection, Immunity & Inflammation, University of Glasgow
| | - D Porter
- From the Institute of Infection, Immunity & Inflammation, University of Glasgow
| | - J Liversidge
- Division of Applied Medicine, School of Medicine and Dentistry, University of Aberdeen
| | - I McInnes
- From the Institute of Infection, Immunity & Inflammation, University of Glasgow
| | - C Goodyear
- From the Institute of Infection, Immunity & Inflammation, University of Glasgow
| | - V Athwal
- From the Manchester University Foundation NHS Trust
- University of Manchester
| | | | | | | | | | - N A Hanley
- From the Manchester University Foundation NHS Trust
- University of Manchester
| | | | - T Briggs
- From the Manchester Centre of Genomic Medicine, University of Manchester
| | - J Reynolds
- Division of Musculoskeletal & Dermatological Sciences, University of Manchester
| | - G Rice
- From the Manchester Centre of Genomic Medicine, University of Manchester
| | - V Bondet
- Immunobiology of Dendritic Cells, Institut Pasteur
| | - E Bruce
- Division of Musculoskeletal & Dermatological Sciences, University of Manchester
| | - Y Crow
- Laboratory of Neurogenetics and Neuroinflammation, INSERM UMR1163, Institut Imagine
| | - D Duffy
- Immunobiology of Dendritic Cells, Institut Pasteur
| | - B Parker
- Division of Musculoskeletal & Dermatological Sciences, University of Manchester
| | - I Bruce
- Division of Musculoskeletal & Dermatological Sciences, University of Manchester
| | - K Martin
- From the University of Manchester
| | | | | | | | - V Athwal
- From the University of Manchester
| | - L Zeef
- From the University of Manchester
| | - S Farrow
- From the University of Manchester
- Respiratory Therapy Area, GlaxoSmithKline
| | | | | | | | - N Hanley
- From the University of Manchester
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2
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Posth C, Nägele K, Colleran H, Valentin F, Bedford S, Kami KW, Shing R, Buckley H, Kinaston R, Walworth M, Clark GR, Reepmeyer C, Flexner J, Maric T, Moser J, Gresky J, Kiko L, Robson KJ, Auckland K, Oppenheimer SJ, Hill AVS, Mentzer AJ, Zech J, Petchey F, Roberts P, Jeong C, Gray RD, Krause J, Powell A. Language continuity despite population replacement in Remote Oceania. Nat Ecol Evol 2018; 2:731-740. [PMID: 29487365 PMCID: PMC5868730 DOI: 10.1038/s41559-018-0498-2] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 02/12/2018] [Indexed: 01/01/2023]
Abstract
Recent genomic analyses show that the earliest peoples reaching Remote Oceania-associated with Austronesian-speaking Lapita culture-were almost completely East Asian, without detectable Papuan ancestry. However, Papuan-related genetic ancestry is found across present-day Pacific populations, indicating that peoples from Near Oceania have played a significant, but largely unknown, ancestral role. Here, new genome-wide data from 19 ancient South Pacific individuals provide direct evidence of a so-far undescribed Papuan expansion into Remote Oceania starting ~2,500 yr BP, far earlier than previously estimated and supporting a model from historical linguistics. New genome-wide data from 27 contemporary ni-Vanuatu demonstrate a subsequent and almost complete replacement of Lapita-Austronesian by Near Oceanian ancestry. Despite this massive demographic change, incoming Papuan languages did not replace Austronesian languages. Population replacement with language continuity is extremely rare-if not unprecedented-in human history. Our analyses show that rather than one large-scale event, the process was incremental and complex, with repeated migrations and sex-biased admixture with peoples from the Bismarck Archipelago.
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Affiliation(s)
- Cosimo Posth
- Department of Archaeogenetics, Max Planck Institute for the Science of Human History, Jena, Germany.
| | - Kathrin Nägele
- Department of Archaeogenetics, Max Planck Institute for the Science of Human History, Jena, Germany
| | - Heidi Colleran
- Department of Linguistic and Cultural Evolution, Max Planck Institute for the Science of Human History, Jena, Germany.
| | - Frédérique Valentin
- Maison de l'Archéologie et de l'Ethnologie, CNRS, UMR 7041, Nanterre, France
| | - Stuart Bedford
- Department of Linguistic and Cultural Evolution, Max Planck Institute for the Science of Human History, Jena, Germany
- School of Culture, History and Language, College of Asia and the Pacific, Australian National University, Canberra, Australian Capital Territory, Australia
| | - Kaitip W Kami
- Department of Linguistic and Cultural Evolution, Max Planck Institute for the Science of Human History, Jena, Germany
- Vanuatu Cultural Centre, Port-Vila, Vanuatu
| | | | - Hallie Buckley
- Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Rebecca Kinaston
- Department of Archaeogenetics, Max Planck Institute for the Science of Human History, Jena, Germany
- Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Mary Walworth
- Department of Linguistic and Cultural Evolution, Max Planck Institute for the Science of Human History, Jena, Germany
| | - Geoffrey R Clark
- Archaeology and Natural History, College of Asia and the Pacific, Australian National University, Canberra, Australian Capital Territory, Australia
| | - Christian Reepmeyer
- College of Arts, Society and Education, James Cook University, Cairns, Queensland, Australia
| | - James Flexner
- Department of Archaeology, University of Sydney, Sydney, New South Wales, Australia
| | - Tamara Maric
- Service de la Culture et du Patrimoine, Punaauia, Tahiti, French Polynesia
| | - Johannes Moser
- Commission for Archaeology of Non-European Cultures, German Archaeological Institute, Bonn, Germany
| | - Julia Gresky
- Department of Natural Sciences, German Archaeological Institute, Berlin, Germany
| | - Lawrence Kiko
- Solomon Islands National Museum, Honiara, Solomon Islands
| | - Kathryn J Robson
- MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Kathryn Auckland
- Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | | | - Adrian V S Hill
- Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | | | - Jana Zech
- Department of Archaeology, Max Planck Institute for the Science of Human History, Jena, Germany
| | - Fiona Petchey
- Waikato Radiocarbon Dating Laboratory, The University of Waikato , Hamilton, New Zealand
| | - Patrick Roberts
- Department of Archaeology, Max Planck Institute for the Science of Human History, Jena, Germany
| | - Choongwon Jeong
- Department of Archaeogenetics, Max Planck Institute for the Science of Human History, Jena, Germany
| | - Russell D Gray
- Department of Linguistic and Cultural Evolution, Max Planck Institute for the Science of Human History, Jena, Germany
| | - Johannes Krause
- Department of Archaeogenetics, Max Planck Institute for the Science of Human History, Jena, Germany.
| | - Adam Powell
- Department of Archaeogenetics, Max Planck Institute for the Science of Human History, Jena, Germany.
- Department of Linguistic and Cultural Evolution, Max Planck Institute for the Science of Human History, Jena, Germany.
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3
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Parks T, Mirabel MM, Kado J, Auckland K, Nowak J, Rautanen A, Mentzer AJ, Marijon E, Jouven X, Perman ML, Cua T, Kauwe JK, Allen JB, Taylor H, Robson KJ, Deane CM, Steer AC, Hill AVS. Association between a common immunoglobulin heavy chain allele and rheumatic heart disease risk in Oceania. Nat Commun 2017; 8:14946. [PMID: 28492228 PMCID: PMC5437274 DOI: 10.1038/ncomms14946] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Accepted: 02/15/2017] [Indexed: 12/19/2022] Open
Abstract
The indigenous populations of the South Pacific experience a high burden of rheumatic heart disease (RHD). Here we report a genome-wide association study (GWAS) of RHD susceptibility in 2,852 individuals recruited in eight Oceanian countries. Stratifying by ancestry, we analysed genotyped and imputed variants in Melanesians (607 cases and 1,229 controls) before follow-up of suggestive loci in three further ancestral groups: Polynesians, South Asians and Mixed or other populations (totalling 399 cases and 617 controls). We identify a novel susceptibility signal in the immunoglobulin heavy chain (IGH) locus centring on a haplotype of nonsynonymous variants in the IGHV4-61 gene segment corresponding to the IGHV4-61*02 allele. We show each copy of IGHV4-61*02 is associated with a 1.4-fold increase in the risk of RHD (odds ratio 1.43, 95% confidence intervals 1.27–1.61, P=4.1 × 10−9). These findings provide new insight into the role of germline variation in the IGH locus in disease susceptibility. Rheumatic heart disease (RHD) is a chronic auto-inflammatory reaction to group A streptococcal infection, and frequently occurs in individuals from the South Pacific. This study finds a novel association between an immunoglobulin heavy chain allele and risk of RHD in Pacific Islanders and South Asians.
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Affiliation(s)
- Tom Parks
- Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Mariana M Mirabel
- Paris Centre de Recherche Cardiovasculaire, Institut National de la Santé et de la Recherche Médicale, Hôpital Européen Georges Pompidou, 56, rue Leblanc, 75908 Paris, France
| | - Joseph Kado
- Department of Paediatrics, Ministry of Health and Medical Services, Colonial War Memorial Hospital, Brown Street, Suva, Fiji.,College of Medicine, Nursing &Health Sciences, Fiji National University, Brown Street, Suva, Fiji
| | - Kathryn Auckland
- Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Jaroslaw Nowak
- Department of Statistics, University of Oxford, Peter Medawar Building for Pathogen Research, Oxford OX1 3S, UK
| | - Anna Rautanen
- Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Alexander J Mentzer
- Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Eloi Marijon
- Paris Centre de Recherche Cardiovasculaire, Institut National de la Santé et de la Recherche Médicale, Hôpital Européen Georges Pompidou, 56, rue Leblanc, 75908 Paris, France.,Faculté de Médecine Paris Descartes, Université Paris Descartes, 15, rue de l'école de medicine, 75006 Paris, France
| | - Xavier Jouven
- Paris Centre de Recherche Cardiovasculaire, Institut National de la Santé et de la Recherche Médicale, Hôpital Européen Georges Pompidou, 56, rue Leblanc, 75908 Paris, France.,Faculté de Médecine Paris Descartes, Université Paris Descartes, 15, rue de l'école de medicine, 75006 Paris, France
| | - Mai Ling Perman
- College of Medicine, Nursing &Health Sciences, Fiji National University, Brown Street, Suva, Fiji
| | - Tuliana Cua
- Rheumatic Heart Disease Control Programme, Ministry of Health and Medical Services, Colonial War Memorial Hospital, Brown Street, Suva, Fiji
| | - John K Kauwe
- College of Life Sciences, Brigham Young University, 4146 Life Sciences Building, Provo, Utah 84602, USA
| | - John B Allen
- College of Life Sciences, Brigham Young University, 4146 Life Sciences Building, Provo, Utah 84602, USA
| | - Henry Taylor
- Rheumatic Heart Disease Control Programme, Samoa Ministry of Health, Moto'otua, Ifiifi Street, Apia, Samoa
| | - Kathryn J Robson
- MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DS, UK
| | - Charlotte M Deane
- Department of Statistics, University of Oxford, Peter Medawar Building for Pathogen Research, Oxford OX1 3S, UK
| | - Andrew C Steer
- Centre for International Child Health, University of Melbourne, 50 Flemington Road, Parkville, Melbourne Victoria 3052, Australia.,Murdoch Children's Research Institute, 50 Flemington Road, Parkville, Melbourne, Victoria 3052, Australia
| | - Adrian V S Hill
- Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
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4
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Kotre CJ, Robson KJ. Phase-contrast and magnification radiography at diagnostic X-ray energies using a pseudo-microfocus X-ray source. Br J Radiol 2014; 87:20130734. [PMID: 24779409 DOI: 10.1259/bjr.20130734] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE To investigate the use of conventional diagnostic X-ray tubes for applications in which specialist microfocus sources are normally required. METHODS A conventional diagnostic X-ray tube was used in conjunction with a range of apertures to investigate improvements in spatial resolution using a line-pairs test object. Phase-contrast effects were investigated by varying source-to-object and object-to-receptor distances using a 2-French catheter as a clinically realistic test object. RESULTS For magnification radiography using a computed radiography receptor and conventional X-ray tube with a 1-mm nominal focus size, the limiting spatial resolution was improved from 3.55 line-pairs per millimetre, for a conventional contact image, to 5.6 line-pairs per millimetre, for a ×2 magnified view with a 250-µm aperture. For inline phase-contrast radiography, phase contrast enhancement of a 2-French catheter was demonstrated, and the expected trends with variations in source-to-object and object-to-receptor distances were found. Images of a neonatal phantom demonstrated a subtle improvement in visibility of a superimposed 1-French catheter simulating a percutaneously inserted central catheter for no increase in patient radiation dose. CONCLUSION Spatial resolution improvement and visible phase contrast can be produced in clinically relevant objects using a pseudo-microfocus geometry at X-ray energies in the normal diagnostic range, using conventional diagnostic X-ray tubes and image receptors. The disadvantages of the proposal are the large distances required to produce phase contrast and limitations imposed by the resulting tube loading. ADVANCES IN KNOWLEDGE It is possible to use conventional diagnostic X-ray equipment in applications that normally require microfocus X-ray sources. This presents some possibilities for clinical applications.
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Affiliation(s)
- C J Kotre
- 1 Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester, UK
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5
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Abstract
Breast imaging in the UK is currently undergoing a major change, with the widespread implementation of full-field digital mammography (FFDM) equipment. This article looks at some of the advanced imaging techniques that have become possible following the development of FFDM units. These techniques may prove to be useful additions to standard mammography for some groups of women.
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Affiliation(s)
- K J Robson
- Regional Medical Physics Department, Freeman Hospital, Newcastle upon Tyne NE7 7DN, UK.
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6
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Flanagan KL, Plebanski M, Odhiambo K, Sheu E, Mwangi T, Gelder C, Hart K, Kortok M, Lowe B, Robson KJ, Marsh K, Hill AVS. Cellular reactivity to the p. Falciparum protein trap in adult kenyans: novel epitopes, complex cytokine patterns, and the impact of natural antigenic variation. Am J Trop Med Hyg 2006; 74:367-75. [PMID: 16525093] [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] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/07/2023] Open
Abstract
Malaria vaccines based on thrombospondin-related adhesive protein of Plasmodium falciparum (Pf TRAP) are currently undergoing clinical trials in humans. This study was designed to investigate naturally acquired cellular immunity to Pf TRAP in adults from a target population for future trials of TRAP-based vaccines in Kilifi, Kenya. We first tested reactivity to a panel of 53 peptides spanning Pf TRAP and identified 26 novel T-cell epitopes. A panel of naturally occurring polymorphic variant epitope peptides were made to the most commonly recognized epitope regions and tested for ability to elicit IFN-gamma, IL-4, and IL-10 production. These data provide for the first time a complex cytokine matrix mapping naturally induced T-cell responses to TRAP and suggest that T-cell responses boosted by vaccination with Pf TRAP could stimulate the release of competing pro- and anti-inflammatory cytokines. They further define polymorphic variants able to boost specific Th1, Th2, and possibly Tr1 reactivity.
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Affiliation(s)
- Katie L Flanagan
- Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Headington, Oxford, United Kingdom.
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7
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Zaahl MG, Merryweather-Clarke AT, Kotze MJ, van der Merwe S, Warnich L, Robson KJ. Gene symbol: DCYTB/CYBRD1. Disease: primary iron overload. Hum Genet 2005; 118:546. [PMID: 16521301] [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: 05/07/2023]
Affiliation(s)
- M G Zaahl
- Department of Genetics, University of Stellenbosch, South Africa
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8
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Abstract
The increased use of soft-copy reporting introduces new concerns over the effect of viewing conditions on the observer's ability to report images. Owing to their lower luminance, electronic display screens may be more susceptible to poor viewing conditions than conventional viewing boxes and there is the potential for images to be displayed in locations not optimised for viewing radiographs. In the present work, the effects of sub-optimal viewing conditions on the observer's performance for images on an electronic display device are investigated. A test object was used to produce a computed radiography image containing a wide range of grey levels. The image was scored under quasi-ideal and sub-optimal conditions and the effect of changing the viewing conditions on the observer's performance determined. Basic photometric quantities were used to characterise the viewing conditions and the degradation in observer performance related to these quantities. The presence of structured reflection had a significant effect on the observer's ability to discern low-contrast objects. The study demonstrates the need for adequate viewing conditions especially when images are displayed on low luminance devices in sub-optimal conditions.
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Affiliation(s)
- K J Robson
- Regional Medical Physics Department, Newcastle General Hospital, Newcastle upon Tyne NE4 6BE, UK.
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9
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Abstract
An image restoration approach based on a Bayesian maximum entropy method (MEM) has been applied to a radiological image deconvolution problem, that of reduction of geometric blurring in magnification mammography. The aim of the work is to demonstrate an improvement in image spatial resolution in realistic noisy radiological images with no associated penalty in terms of reduction in the signal-to-noise ratio perceived by the observer. Images of the TORMAM mammographic image quality phantom were recorded using the standard magnification settings of 1.8 magnification/fine focus and also at 1.8 magnification/broad focus and 3.0 magnification/fine focus; the latter two arrangements would normally give rise to unacceptable geometric blurring. Measured point-spread functions were used in conjunction with the MEM image processing to de-blur these images. The results are presented as comparative images of phantom test features and as observer scores for the raw and processed images. Visualization of high resolution features and the total image scores for the test phantom were improved by the application of the MEM processing. It is argued that this successful demonstration of image de-blurring in noisy radiological images offers the possibility of weakening the link between focal spot size and geometric blurring in radiology, thus opening up new approaches to system optimization.
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Affiliation(s)
- A Jannetta
- School of Informatics, Northumbria University, Newcastle-upon-Tyne, NE1 8ST, UK
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10
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Kotre CJ, Charlton S, Robson KJ, Birch IP, Willis SP, Thornley M. Application of low dose rate pulsed fluoroscopy in cardiac pacing and electrophysiology: patient dose and image quality implications. Br J Radiol 2004; 77:597-9. [PMID: 15238407 DOI: 10.1259/bjr/54198101] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [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: 11/05/2022] Open
Abstract
The performance of a low dose rate pulsed fluoroscopy option and its successful application to cardiac pacing and electrophysiology is reported. Low dose rate 6.25 frames per second pulsed fluoroscopy was made available in two catheter laboratories at a specialist cardiac centre in February 2003, and was adopted as the standard imaging technique for cardiac pacing procedures. The image quality was found to be considerably poorer than conventional modern units, being very similar to that which would have been accepted as adequate performance 20 years ago, but at less than one-tenth of the dose rate. No problems with the clinical acceptance of this imaging mode for cardiac pacing and electrophysiology have been reported. The already low median patient dose-area product for pacing at this cardiac centre was further reduced by 50% with the introduction of this fluoroscopy option.
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Affiliation(s)
- C J Kotre
- Regional Medical Physics Department, Newcastle General Hospital, Newcastle-upon-Tyne NE7 7DN, UK
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11
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Smith D, Lehmann DJ, Combrinck M, Warden DR, Wimhurst VL, Livesey KJ, Merryweather-Clarke AT, Robson KJ. P4-100 Interaction between the C2 allele of transferrin and the C282Y allele of the haemochromatosis gene (HFE) as risk factors for Alzheimer's disease. Neurobiol Aging 2004. [DOI: 10.1016/s0197-4580(04)81658-0] [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: 10/26/2022]
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12
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Abstract
Maintaining the correct iron balance is crucial to good health. Disorders of iron homeostasis have a global distribution. As iron is not actively excreted by the body, understanding the role of proteins involved in regulating iron uptake is essential to our understanding of disease involving iron homeostasis. Over the past 10 years, major advances have been made in understanding the genetics of iron metabolism and this has led to identification of a number of new proteins, including hepcidin, involved in iron homeostasis.
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Affiliation(s)
- K J Robson
- Weatherall Institute of Molecular Medicine, MRC Molecular Haematology Unit, John Radcliffe Hospital, Oxford, OX3 9DS, UK.
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13
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Kotre CJ, Birch IP, Robson KJ. Short communication: anomalous image quality phantom scores in magnification mammography: evidence of phase contrast enhancement. Br J Radiol 2002; 75:170-3. [PMID: 11893641 DOI: 10.1259/bjr.75.890.750170] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [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: 11/05/2022] Open
Abstract
Anomalously high image quality scores were noted for images of the Leeds TORMAM phantom obtained using magnification mammography. Comparison of optical density profiles of fibre features in the images with non-magnified images and images previously obtained using an in-line phase contrast geometry showed the presence of phase contrast enhancement in the magnification images. The effect on the phantom score is particularly marked for this design of phantom owing to its use of fibres, which tend to enhance well. A large proportion of the phantom score is associated with fibrous features. It is concluded that direct comparison of TORMAM phantom scores from magnified images with those from non-magnified images is not valid due to the different balance of physical mechanisms forming the two kinds of image.
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Affiliation(s)
- C J Kotre
- Regional Medical Physics Department, Newcastle General Hospital, Newcastle-upon-Tyne NE4 6BE, UK
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14
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Schneider J, Langermans JA, Gilbert SC, Blanchard TJ, Twigg S, Naitza S, Hannan CM, Aidoo M, Crisanti A, Robson KJ, Smith GL, Hill AV, Thomas AW. A prime-boost immunisation regimen using DNA followed by recombinant modified vaccinia virus Ankara induces strong cellular immune responses against the Plasmodium falciparum TRAP antigen in chimpanzees. Vaccine 2001; 19:4595-602. [PMID: 11535306 DOI: 10.1016/s0264-410x(01)00260-2] [Citation(s) in RCA: 51] [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: 01/11/2023]
Abstract
Two chimpanzees were vaccinated intramuscularly against malaria using plasmid DNA expressing the pre-erythrocytic antigens thrombospondin related adhesion protein (PfTRAP) and liver stage specific antigen-1 (PfLSA-1) of Plasmodium falciparum together with GM-CSF protein. A recombinant modified vaccinia virus Ankara (MVA) expressing PfTRAP was injected intramuscularly 6 weeks later to boost the immune response. This sequence of antigen delivery induced a specific and long-lasting T cell and antibody response to PfTRAP as detected by ELISPOT assay and ELISA. Antibody responses were detected after four DNA injections, and were boosted by injection of recombinant MVA expressing PfTRAP. Interferon-gamma secreting antigen-specific T cells were detected in both animals, but only after boosting with recombinant MVA. By screening a panel of PfTRAP-derived peptides, an epitope was identified that was recognized by cytotoxic T lymphocytes in one of the chimpanzees studied. T cells specific for this epitope were present in PBMCs and liver-infiltrating lymphocytes at a frequency of between 1 in 200 and 1 in 500. The high immunogenicity of this prime-boost regimen in chimpanzees supports further assessment of this delivery strategy for the induction of protection against P. falciparum malaria in humans.
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MESH Headings
- Animals
- Antibodies, Protozoan/biosynthesis
- Antigens, Protozoan/genetics
- Antigens, Protozoan/immunology
- COS Cells
- Chick Embryo
- Chlorocebus aethiops
- DNA, Protozoan/genetics
- Enzyme-Linked Immunosorbent Assay
- Epitopes/immunology
- Fibroblasts/virology
- Genetic Vectors/genetics
- Granulocyte-Macrophage Colony-Stimulating Factor/pharmacology
- Humans
- Immunity, Cellular
- Immunization Schedule
- Immunization, Secondary
- Leukocytes, Mononuclear/immunology
- Malaria Vaccines/administration & dosage
- Malaria Vaccines/immunology
- Male
- Pan troglodytes
- Plasmodium falciparum/immunology
- Protozoan Proteins/genetics
- Protozoan Proteins/immunology
- Recombinant Proteins/pharmacology
- T-Lymphocytes, Cytotoxic/immunology
- Transfection
- Vaccines, DNA/administration & dosage
- Vaccines, DNA/immunology
- Vaccinia virus/genetics
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Affiliation(s)
- J Schneider
- Molecular Immunology Group, Institute of Molecular Medicine, Nuffield Department of Medicine, University of Oxford, John Radcliffe Hospital, OX3 9DU, Oxford, UK.
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15
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Abstract
A method of identifying the dose per image when quantum mottle no longer dominates the image statistics is presented as a first step towards quantitative optimization in native and subtracted digital fluorography. The method is based on measurements of threshold contrast over a range of receptor doses and the application of a simple model of the threshold contrast detection task to estimate the magnitude of system noise sources. The point at which system and quantum noise sources are equal in magnitude is proposed as the practical upper limit for dose per image. The method is applied to a typical digital fluorography system and the results are placed into the context of the range of dose per image values found from a regional survey of digital fluorography units. While there is broad agreement between the dose per image values in the survey with values predicted from the experimental method, the considerable spread in survey doses suggests there are instances where the use of a high dose per image is unjustified.
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Affiliation(s)
- N W Marshall
- Regional Medical Physics Department, Newcastle General Hospital, Newcastle upon Tyne, UK
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16
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Abstract
In the National Health Service Breast Screening Programme, regular assessment of the mean glandular doses received by a group of women is recognized as an important part of a quality assurance programme. The use of different tube voltages, to improve the beam penetration for thick or dense breasts, and of X-ray units with programmable exposure modes, requires a large number of measurements to ensure that all the values of tube output and half value layer required for the dose calculations are available. In this work, a computer model is used to produce data that allow the calculation of tube output and half value layer for the range of clinically encountered conditions from measurements routinely obtained during quality assurance tests. The data are given as a series of equations and parameters, enabling the calculations to be easily incorporated into a dose calculation spreadsheet. The results of an experimental verification of the model are presented, showing good agreement between the measured and predicted values of half value layer and tube output for a range of combinations of target, filter and tube voltage.
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Affiliation(s)
- K J Robson
- Regional Medical Physics Department, Newcastle General Hospital, Westgate Road, Newcastle upon Tyne NE4 6BE, UK
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17
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Abstract
Hereditary hemochromatosis (HH) is a common autosomal recessive disorder of iron metabolism. Iron absorption from the gut is inappropriately high, resulting in increasing iron overload. The hemochromatosis gene (HFE) was identified in 1996 by extensive positional cloning by many groups over a period of about 20 years. Two missense mutations were identified. Homozygosity for one of these, a substitution of a tyrosine for a conserved cysteine (C282Y), has now clearly been shown to be associated with HH in 60-100% of patients. The role of the second mutation, the substitution of an aspartic acid for a histidine (H63D), is not so clear but compound heterozygotes for both these mutations have a significant risk of developing HH. Here we review other putative mutations in the HFE gene and document a number of diallelic polymorphisms in HFE introns.
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Affiliation(s)
- J J Pointon
- MRC Molecular Haematology Unit, Institute Molecular Medicine, Headington, Oxford, UK.
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18
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Abstract
Hereditary hemochromatosis (HH) is a common autosomal recessive disorder causing inappropriate dietary iron absorption that affects North Europeans. HH is associated with the C282Y mutation of the HFE gene, and the H63D mutation to a lesser degree. Both mutations are abundant in Europe, with H63D also appearing in North Africa, the Middle East, and Asia. Emigration from Europe over the past 500 years has introduced C282Y and H63D to America, Australia, New Zealand, and South Africa in an essentially predictable fashion. The distinctive characteristics of the population genetics of HH are the confined racial distribution and high frequency in North European peoples. C282Y frequencies in North Europeans are typically between 5% and 10%, with homozygotes accounting for between 1/100 and 1/400 of these populations. The scarcity of the C282Y mutation in other populations accounts for the lack of HH in non-Europeans.
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19
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Abstract
The gene for hemochromatosis was identified in 1996 and two mutations were found. Homozygosity for one of these, C282Y, is associated with hemochromatosis in a high percentage of patients. Genetic analysis of patient DNA is, therefore, a very useful tool to aid and confirm diagnosis and to screen asymptomatic relatives of patients to identify those at risk of developing this common, easily treated disease.
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Affiliation(s)
- J J Pointon
- MRC Molecular Haematology Unit, Institute Molecular Medicine, Headington, Oxford, UK.
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20
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Abstract
We report a syndrome in a middle-aged woman characterized by tender erythematous plaques with histologic evidence of dramatic dermal vessel occlusion. These cutaneous findings occurred in association with progressive inferior vena cava and portal vein thrombosis while on coumarin anticoagulation, following hepatic transplantation for Budd-Chiari syndrome. The material occluding dermal vessels was proven by immunohistochemical staining to be platelet plugs. These findings led to the diagnosis of an underlying myeloproliferative disorder explaining both her cutaneous and liver abnormalities and institution of appropriate platelet directed anticoagulation with aspirin.
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Affiliation(s)
- M S Stone
- Departments of Dermatology and Pathology, University of Iowa College of Medicine, Iowa City, Iowa, USA
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21
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Robson KJ, Cunningham NM, Kruzan KL, Patel DS, Kreiter CD, O'Donnell MJ, Arpey CJ. Pulsed-dye laser versus conventional therapy in the treatment of warts: a prospective randomized trial. J Am Acad Dermatol 2000; 43:275-80. [PMID: 10906651 DOI: 10.1067/mjd.2000.106365] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.2] [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
BACKGROUND The clinical management of verrucae vulgaris is often challenging, and no ideal treatment currently exists. Early studies suggested that pulsed-dye laser (PDL) therapy might be highly effective in the treatment of verrucae, although more recent reports have been less optimistic. Previous studies have been retrospective or have consisted of a series of patients treated with PDL alone. OBJECTIVE Our objective was to prospectively evaluate the efficacy of PDL therapy versus conventional therapy with liquid nitrogen cryotherapy or cantharidin in the treatment of warts. METHODS Forty healthy adult patients with verrucae were randomized to receive either PDL (585 nm) therapy or conventional therapy. All enrollees also performed home therapy. Patients were eligible for up to 4 treatment sessions at 1-month intervals. Warts were individually counted and measured at the time of each treatment session. Complete response was defined as complete absence of verrucae with the presence of dermatoglyphics, and partial response was defined as a 50% or greater reduction in wart size. RESULTS A total of 194 warts were evaluated by the conclusion of the study. Complete response was noted in an average of 70% of the warts treated with conventional therapy and in 66% of those in the PDL group; this was statistically insignificant. Partial response was observed in an average of 82% of the warts in patients treated with conventional therapy and 87% in the PDL group. Verruca vulgaris responded more readily than verruca plantaris in both treatment groups. The mean number of treatments to achieve success was similar in both groups. CONCLUSION The PDL is an efficacious form of therapy for verrucae, as is conventional therapy. PDL therapy should be considered among the better established approaches in the treatment of warts, although data from this trial suggest that this approach is probably not superior.
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Affiliation(s)
- K J Robson
- Department of Dermatology and the Office of Consultation and Research in Medical Education, University of Iowa Hospitals and Clinics, Iowa City 52242, USA
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22
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Merryweather-Clarke AT, Simonsen H, Shearman JD, Pointon JJ, Nørgaard-Pedersen B, Robson KJ. A retrospective anonymous pilot study in screening newborns for HFE mutations in Scandinavian populations. Hum Mutat 2000; 13:154-9. [PMID: 10094552 DOI: 10.1002/(sici)1098-1004(1999)13:2<154::aid-humu8>3.0.co;2-e] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [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: 01/06/2023]
Abstract
We have retrospectively analyzed 837 random anonymized dried blood spot (DBS) samples from neonatal screening programs in Scandinavia for mutations in HFE, the candidate gene for hemochromatosis. We have found C282Y allele frequencies of 2.3% (+2.0%) (-1.3%) in Greenland, 4.5%+/-1.9% in Iceland, 5.1%+/-2.3% in the Faeroe Islands, and 8.2%+/-2.7% in Denmark. The high prevalence of HFE mutations in Denmark suggests that population screening for the C282Y mutation could be highly advantageous in terms of preventive health care. Long-term follow-up evaluation of C282Y homozygotes and H63D/C282Y compound heterozygotes will give an indication of the penetrance of the mutations.
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23
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Merryweather-Clarke AT, Pointon JJ, Shearman JD, Robson KJ, Jouanolle AM, Mosser A, David V, Le Gall JY, Halsall DJ, Elsey TS, Kelly A, Cox TM, Clare M, Bomford A, Vandwalle JL, Rochette J, Borot N, Coppin H, Roth MP, Ryan E, Crowe J, Totaro A, Gasparini P, Roetto A, Walker AP. Polymorphism in intron 4 of HFE does not compromise haemochromatosis mutation results. The European Haemochromatosis Consortium. Nat Genet 1999; 23:271. [PMID: 10545942 DOI: 10.1038/15452] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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24
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Wengelnik K, Spaccapelo R, Naitza S, Robson KJ, Janse CJ, Bistoni F, Waters AP, Crisanti A. The A-domain and the thrombospondin-related motif of Plasmodium falciparum TRAP are implicated in the invasion process of mosquito salivary glands. EMBO J 1999; 18:5195-204. [PMID: 10508153 PMCID: PMC1171590 DOI: 10.1093/emboj/18.19.5195] [Citation(s) in RCA: 114] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Sporozoites from all Plasmodium species analysed so far express the thrombospondin-related adhesive protein (TRAP), which contains two distinct adhesive domains. These domains share sequence and structural homology with von Willebrand factor type A-domain and the type I repeat of human thrombospondin (TSP). Increasing experimental evidence indicates that the adhesive domains bind to vertebrate host ligands and that TRAP is involved, through an as yet unknown mechanism, in the process of sporozoite motility and invasion of both mosquito salivary gland and host hepatocytes. We have generated transgenic P.berghei parasites in which the endogenous TRAP gene has been replaced by either P.falciparum TRAP (PfTRAP) or mutated versions of PfTRAP carrying amino acid substitutions or deletions in the adhesive domains. Plasmodium berghei sporozoites carrying the PfTRAP gene develop normally, are motile, invade mosquito salivary glands and infect the vertebrate host. A substitution in a conserved residue of the A-domain or a deletion in the TSP motif of PfTRAP impairs the sporozoites' ability to invade mosquito salivary glands. Notably, midgut sporozoites from these transgenic parasites are still able to infect mice. Midgut sporozoites carrying a mutation in the A-domain of PfTRAP are motile, while no gliding motility could be detected in sporozoites with a TSP motif deletion.
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Affiliation(s)
- K Wengelnik
- Imperial College of Science, Technology and Medicine, Department of Biology, Imperial College Road, London SW7 2AZ
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25
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Dolo A, Modiano D, Doumbo O, Bosman A, Sidibé T, Keita MM, Naitza S, Robson KJ, Crisanti A. Thrombospondin related adhesive protein (TRAP), a potential malaria vaccine candidate. Parassitologia 1999; 41:425-8. [PMID: 10697897] [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] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
We have investigated whether naturally induced immunity to Plasmodium falciparum thrombospondin related adhesive protein contributes to protection against malaria in humans. We have carried out a case control study in children living in an endemic region of West Africa to reveal associations between PfTRAP seroprevalence and the risk of cerebral malaria. Sera collected from the case and control groups were analysed by ELISA to compare their serum reactivity against PfTRAP, the circumsporozoite protein and the merozoite surface protein 1. Children with uncomplicated malaria had a significantly higher PfTRAP seroprevalence when compared to children with cerebral malaria. The risk of developing cerebral malaria appeared to depend on the reciprocal relationship between sporozoite inoculation rates and humoral immunity against PfTRAP. Our results suggest that naturally induced humoral immunity against PfTRAP contributes to the development of protection against severe malaria. Experimentally induced immunity against TRAP in different rodent models has consistently proven to elicit a high degree of protection against malaria. This together with the functional properties of TRAP and data describing CD4 and CD8 epitopes for PfTRAP indicate that this molecule could increase the protective efficiency of available sporozoite malaria vaccines.
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Affiliation(s)
- A Dolo
- Départment d'Epidémiologie des Affections Parasitaires, Ecole Nationale de Médecine, de Pharmacie et d'Odonto-Stomatologie, Bamako, Mali
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26
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Abstract
Mutations in the haemochromatosis (HFE) gene cause most of the cases of hereditary haemochromatosis among people of Northern European ancestry while remaining a rare cause of iron overload among indigenous persons of the Asia-Pacific region. Advances in understanding of the role of the HFE protein product and other recently cloned iron transporters signify an exciting period, as previously unknown components of the iron metabolism pathway are revealed one by one. Epidemiological studies have shown that this gene is more widespread than its phenotypic expression would suggest and that the heterozygous state may be implicated in the expression of other diseases of the liver such as porphyria cutanea tarda, hepatitis C virus infection and non-alcoholic steatohepatitis. The diagnosis, management and ethical implications for clinical practice in the aftermath of this discovery are discussed.
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Affiliation(s)
- M Mortimore
- Clinical Sciences Unit, The Queensland Institute of Medical Research, Brisbane, Australia
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27
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Kotre CJ, Robson KJ, Simpson W. Improving the visibility of radio-opaque markers in mammography. Br J Radiol 1999; 72:799-801. [PMID: 10624347 DOI: 10.1259/bjr.72.860.10624347] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Owing to the high mean film optical densities used in breast screening mammography, and the very high maximum optical densities that can be obtained using modern mammographic film, it is often found that for larger exposures the nominally radio-opaque markers used to identify views, left and right etc., cannot be seen using a normal illuminator. A simple solution to this problem is to back the radio-opaque markers with a thin metal filter chosen to keep the marker information visible over a wide range of exposures. A convenient material for this is copper foil in the form of self-adhesive tape. The improvement in marker contrast produced by this modification is illustrated using point optical density measurements on marked test films produced at the extremes of the mammographic exposure range.
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Affiliation(s)
- C J Kotre
- Regional Medical Physics Department, Newcastle General Hospital, Newcastle-upon-Tyne, UK
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28
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Flanagan KL, Plebanski M, Akinwunmi P, Lee EA, Reece WH, Robson KJ, Hill AV, Pinder M. Broadly distributed T cell reactivity, with no immunodominant loci, to the pre-erythrocytic antigen thrombospondin-related adhesive protein of Plasmodium falciparum in West Africans. Eur J Immunol 1999; 29:1943-54. [PMID: 10382757 DOI: 10.1002/(sici)1521-4141(199906)29:06<1943::aid-immu1943>3.0.co;2-1] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Protective immunity to malaria has been achieved in human volunteers utilizing the pre-erythrocytic Plasmodium falciparum antigen, the circumsporozoite protein (CS). However, T cell reactivity to CS is focused on several highly polymorphic T cell epitope regions, potentially limiting the efficacy of any vaccine to specific malaria strains. Another important pre-erythrocytic malaria antigen, the thrombospondin-related adhesive protein (TRAP), can induce protection in animal models of malaria, but knowledge of human T cell responses is limited to the identification of CD8 T cell epitopes, with no CD4 epitopes identified to date. This comprehensive study assessed reactivity to overlapping peptides spanning almost the whole of P. falciparum TRAP (PfTRAP), as well as peptides selected on the basis of HLA class II-binding motifs. A total of 50 naturally exposed Gambian adults were assessed to define 26 T cell epitopes in PfTRAP capable of inducing rapid IFN-gamma or IL-4 production, as assessed by enzyme-linked immunospot assays. In contrast to the CS protein, this reactivity was broadly distributed along the length of TRAP. Moreover, of the 26 epitopes identified, 10 were found to be conserved in West Africa.
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Affiliation(s)
- K L Flanagan
- Institute of Molecular Medicine, Nuffield Department of Medicine, John Radcliffe Hospital, Oxford, GB
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29
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Rochette J, Pointon JJ, Fisher CA, Perera G, Arambepola M, Arichchi DS, De Silva S, Vandwalle JL, Monti JP, Old JM, Merryweather-Clarke AT, Weatherall DJ, Robson KJ. Multicentric origin of hemochromatosis gene (HFE) mutations. Am J Hum Genet 1999; 64:1056-62. [PMID: 10090890 PMCID: PMC1377829 DOI: 10.1086/302318] [Citation(s) in RCA: 116] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Genetic hemochromatosis (GH) is believed to be a disease restricted to those of European ancestry. In northwestern Europe, >80% of GH patients are homozygous for one mutation, the substitution of tyrosine for cysteine at position 282 (C282Y) in the unprocessed protein. In a proportion of GH patients, two mutations are present, C282Y and H63D. The clinical significance of this second mutation is such that it appears to predispose 1%-2% of compound heterozygotes to expression of the disease. The distribution of the two mutations differ, C282Y being limited to those of northwestern European ancestry and H63D being found at allele frequencies>5%, in Europe, in countries bordering the Mediterranean, in the Middle East, and in the Indian subcontinent. The C282Y mutation occurs on a haplotype that extends </=6 Mb, suggesting that this mutation has arisen during the past 2,000 years. The H63D mutation is older and does not occur on such a large extended haplotype, the haplotype in this case extending </=700 kb. Here we report the finding of the H63D and C282Y mutations on new haplotypes. In Sri Lanka we have found H63D on three new haplotypes and have found C282Y on one new haplotype, demonstrating that these mutations have arisen independently on this island. These results suggest that the HFE gene has been the subject of selection pressure. These selection pressures could be due to infectious diseases, environmental conditions, or other genetic disorders such as anemia.
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Affiliation(s)
- J Rochette
- Génétique Médicale et Lab des Biomolecules, Université Jules Verne de Picardie, Amiens, France
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30
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Naitza S, Spano F, Robson KJ, Crisanti A. The Thrombospondin-related Protein Family of Apicomplexan Parasites: The Gears of the Cell Invasion Machinery. ACTA ACUST UNITED AC 1998; 14:479-84. [PMID: 17040860 DOI: 10.1016/s0169-4758(98)01346-5] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
A number of severe diseases of medical and veterinary importance are caused by parasites of the phylum Apicomplexa. These parasites invade host cells using similar subcellular structures, organelles and molecular species. Proteins containing one or more copies of the type I repeat of human platelet thrombospondin (TSP1), are crucial components of both locomotion and invasion machinery. Members of this family have been identified in Eimeria tenella, E. maxima, Toxoplasma gondii, Cryptosporidium parvum and in all Plasmodium species so far analysed. Here, Andrea Crisanti and colleagues discuss the structure, localization and current understanding of the function of TSP family members in the invasion of target cells by apicomplexan parasites.
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Affiliation(s)
- S Naitza
- Imperial College, Department of Biology, Prince Consort Road, London, UK SW7 2BB
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31
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Abstract
BACKGROUND Keratoacanthoma is a common cutaneous neoplasm, although the persistent form is less common and often more difficult to manage. Multiple treatment approaches have been attempted with variable efficacy. Establishing the diagnosis and selecting a treatment plan for persistent keratoacanthoma is often challenging. OBJECTIVE Our purpose is to describe the difficulty one may encounter in the diagnosis and treatment of persistent keratoacanthoma. Hopefully, review of this clinical conundrum may facilitate the management of the reader's future patients. METHODS We describe a case of persistent keratoacanthoma where the diagnosis was initially elusive and the management challenging. Our thought process during each stage of diagnosis and management is described in the form of "issues" with references to the appropriate literature. RESULTS After several diagnostic and therapeutic interventions, successful treatment was achieved with administration of oral isotretinoin. Long-term remission continued as the dosage was tapered. CONCLUSION Persistent keratoacanthoma may be challenging to diagnose and manage, presenting a clinical conundrum. Careful review of the clinicopathologic presentation and an understanding of the various treatment options may result in a successful outcome.
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MESH Headings
- Administration, Oral
- Chemotherapy, Adjuvant
- Combined Modality Therapy
- Dermatologic Surgical Procedures
- Humans
- Isotretinoin/administration & dosage
- Keratoacanthoma/diagnosis
- Keratoacanthoma/drug therapy
- Keratoacanthoma/pathology
- Keratoacanthoma/surgery
- Male
- Middle Aged
- Neoplasm Recurrence, Local/diagnosis
- Neoplasm Recurrence, Local/drug therapy
- Neoplasm Recurrence, Local/pathology
- Neoplasm Recurrence, Local/surgery
- Neoplasms, Multiple Primary/diagnosis
- Neoplasms, Multiple Primary/drug therapy
- Neoplasms, Multiple Primary/pathology
- Neoplasms, Multiple Primary/surgery
- Skin/pathology
- Skin Neoplasms/diagnosis
- Skin Neoplasms/drug therapy
- Skin Neoplasms/pathology
- Skin Neoplasms/surgery
- Treatment Outcome
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Affiliation(s)
- G C Canas
- Department of Dermatology, University of Iowa Hospitals, Iowa City 52242
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32
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Abstract
Many aspects of dermatologic diagnosis are either of importance or interest to the nondermatologist, and there are many excellent textbooks available for guidance. This article focuses on four categories of conditions that are the source of frequent queries from the primary care setting: (1) common skin diseases that frequently mimic systemic illness, (2) common skin diseases that have important systemic associations, (3) common systemic diseases that have prominent cutaneous findings, and (4) the seldom seen but frequently raised concerns regarding cutaneous signs of internal malignancy.
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Affiliation(s)
- K J Robson
- Department of Dermatology, University of Iowa College of Medicine, Iowa City, USA
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33
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Pointon JJ, Stone C, Shearman JD, Merryweather-Clarke AT, Rosenberg WM, Robson KJ. More microsatellite markers around D6S105. Mol Cell Probes 1998; 12:181-4. [PMID: 9664581 DOI: 10.1006/mcpr.1998.0162] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- J J Pointon
- MRC Molecular Haematology Unit, Institute of Molecular Medicine, Headington, Oxford, UK
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34
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Merryweather-Clarke AT, Worwood M, Parkinson L, Mattock C, Pointon JJ, Shearman JD, Robson KJ. The effect of HFE mutations on serum ferritin and transferrin saturation in the Jersey population. Br J Haematol 1998; 101:369-73. [PMID: 9609537 DOI: 10.1046/j.1365-2141.1998.00736.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.3] [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
High frequencies of the haemochromatosis-related HFE C282Y mutation have been reported in North European populations, in which a high proportion of patients with the disease are homozygotes. However, the degree of penetrance of this genotype is unknown. We determined the HFE C282Y and H63D genotypes of 411 consenting volunteer blood donors on Jersey, and the serum ferritin and transferrin saturation levels of 204 of these volunteers. The C282Y allele frequency was found to be 8.3% in 822 chromosomes, indicating a homozygote frequency of 1/145. Consistent with this, four C282Y homozygotes were detected in 411 volunteers. As there are only 18 patients presently receiving treatment for haemochromatosis on Jersey, out of a total population of about 85000, there is a large discrepancy between the number of haemochromatosis patients and the number of C282Y homozygotes in this population. In a preliminary study of 204 consenting volunteers we found a correlation between transferrin saturation and HFE H63D/ C282Y genotype (P=0.017) and between serum ferritin and genotype (P = 0.056). We also observed elevated values of transferrin saturation in the two C282Y homozygotes assayed. These results suggest that a large proportion of the many undetected C282Y homozygotes on Jersey and in similar populations could be in the preclinical stages of haemochromatosis, and warrant investigation. However, there may be a wide variation in the expression of the condition, and a more extensive study of the level of disease penetrance encompassing a large number of hitherto undetected C282Y homozygotes is therefore imperative.
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Affiliation(s)
- A T Merryweather-Clarke
- MRC Molecular Haematology Unit, Institute of Molecular Medicine, John Radcliffe Hospital, Headington, Oxford
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35
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Merryweather-Clarke AT, Shearman JD, Robson KJ, Pointon JJ, Liu YT, Bomford A, Dooley J, Walker AP, Worwood M. Hemochromatosis-related mutation detection. Blood 1998; 91:2620-1. [PMID: 9516166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
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36
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Schneider J, Gilbert SC, Blanchard TJ, Hanke T, Robson KJ, Hannan CM, Becker M, Sinden R, Smith GL, Hill AV. Enhanced immunogenicity for CD8+ T cell induction and complete protective efficacy of malaria DNA vaccination by boosting with modified vaccinia virus Ankara. Nat Med 1998; 4:397-402. [PMID: 9546783 DOI: 10.1038/nm0498-397] [Citation(s) in RCA: 516] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Immunization with irradiated sporozoites can protect against malaria infection and intensive efforts are aimed at reproducing this effect with subunit vaccines. A particular sequence of subunit immunization with pre-erythrocytic antigens of Plasmodium berghei, consisting of single dose priming with plasmid DNA followed by a single boost with a recombinant modified vaccinia virus Ankara (MVA) expressing the same antigen, induced unprecedented complete protection against P. berghei sporozoite challenge in two strains of mice. Protection was associated with very high levels of splenic peptide-specific interferon-gamma-secreting CD8+ T cells and was abrogated when the order of immunization was reversed. DNA priming followed by MVA boosting may provide a general immunization regime for induction of high levels of CD8+ T cells.
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Affiliation(s)
- J Schneider
- Institute of Molecular Medicine, Nuffield Department of Medicine, University of Oxford, John Radcliffe Hospital, UK.
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37
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Shearman JD, Pointon JJ, Merryweather-Clarke AT, Stone C, Horsley SW, Kearney L, Rosenberg WM, Robson KJ. Rapid mapping of markers applying vectorette technology to YAC fragmentation allows easy assembly of a high-density STS bacterial clone contig spanning the markers D6S1260-D6S1918. Mamm Genome 1998; 9:220-5. [PMID: 9501306 DOI: 10.1007/s003359900729] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
We have generated a detailed physical map of the 6p21.3/p22.1 boundary, using a combination of yeast artificial chromosome (YAC) fragmentation and high-resolution sequence tagged site (STS) content mapping. YACs from the CEPH, St. Louis, and ICRF libraries have been used to construct a 4.5-Mb contig spanning the markers D6S306 to D6S1571. YAC insert sizes were determined by pulsed field gel electrophoresis (PFGE). Chimerism of YACs was determined by fluorescent in situ hybridization (FISH), and their integrity was determined by fingerprinting with Alu-PCR. We have identified 10 new CA repeat loci in this region as well as over 50 novel STSs, several tRNA genes, a new histone H2B gene and the phospholipase D gene. Using these new markers, we have rapidly generated a bacterial clone contig of over 250 kb, spanning the markers D6S1260 to D6S1918 (WI-3111) with STSs spaced on average every 6 kb.
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Affiliation(s)
- J D Shearman
- MRC Molecular Haematology Unit, Institute of Molecular Medicine, Headington, Oxford, UK
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38
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Stone MS, Robson KJ, LeBoit PE. Subacute radiation dermatitis from fluoroscopy during coronary artery stenting: evidence for cytotoxic lymphocyte mediated apoptosis. J Am Acad Dermatol 1998; 38:333-6. [PMID: 9486710 DOI: 10.1016/s0190-9622(98)70577-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [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]
Abstract
A patient with fluoroscopy-induced subacute radiation dermatitis is described. Her biopsy specimen showed vacuolar change and necrotic keratinocytes with lymphocytes in direct apposition, or "satellitosis". Lymphocytes in the dermis and infiltrating the epidermis were predominantly CD8+ and a number of the lymphocytes stained for TIA-1, a cytotoxic granule protein in T-cells and natural killer cells, that appears to be involved in the induction of apoptosis. Our findings suggest cytotoxic lymphocyte mediated apoptosis is involved in the pathogenesis of subacute radiation dermatitis.
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Affiliation(s)
- M S Stone
- Department of Dermatology, University of Iowa College of Medicine, Iowa City, USA
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39
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Robson KJ, Dolo A, Hackford IR, Doumbo O, Richards MB, Keita MM, Sidibe T, Bosman A, Modiano D, Crisanti A. Natural polymorphism in the thrombospondin-related adhesive protein of Plasmodium falciparum. Am J Trop Med Hyg 1998; 58:81-9. [PMID: 9452297 DOI: 10.4269/ajtmh.1998.58.81] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [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
We have developed a typing system using natural sequence variation in the thrombospondin-related adhesive protein (TRAP) gene of Plasmodium falciparum. This method permits a haplotype to be assigned to any particular TRAP gene. We have applied this method to a hospital-based, case control-study in Mali. Previous sequence variation and conservation in TRAP has been confirmed. Particular TRAP haplotypes can be used as geographic hallmarks. Because of the high level of conflict between characters, we have examined the phylogenetic relationships between parasites using a network approach. Having received patient samples from urban and periurban areas of Bamako, the majority of haplotypes were closely related and distinct from TRAP sequences present in other continents. This suggests that the structure of TRAP can only tolerate a limited number of sequence variations to preserve its function but that this is sufficient to allow the parasite to evade the host's immune system until a long-lived immune response can be maintained. It may also reflect host genetics in that certain variants may escape the host immune response more efficiently than others. For vaccine design, sequences from the major regional variants may need to be considered in the production of effective subunit vaccines.
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Affiliation(s)
- K J Robson
- Medical Research Council Molecular Haematology Unit, Institute of Molecular Medicine, University of Oxford, Headington, United Kingdom
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40
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Worwood M, Raha Chowdhury R, Robson KJ, Pointon J, Shearman JD, Darke C. The HLA A1-B8 haplotype extends 6 Mb beyond HLA-A: associations between HLA-A, B, F and 15 microsatellite markers. Tissue Antigens 1997; 50:521-6. [PMID: 9389327 DOI: 10.1111/j.1399-0039.1997.tb02908.x] [Citation(s) in RCA: 24] [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] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Allele frequencies for HLA-A, B and F and 15 microsatellite markers located from 100 kb telomeric to HLA-A to 6 Mb telomeric have been determined in a group of 60 blood donors. Linkage disequilibrium analysis revealed significant haplotype associations even after correction for the number of comparisons made. The HLA-A1, B8 haplotype extends as far as D6S276 (6.0 Mb telomeric to HLA-A). It is important to realize that this common haplotype extends beyond the HLA region, especially when evaluating haplotype associations with particular disorders.
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Affiliation(s)
- M Worwood
- Department of Haematology, University of Wales College of Medicine, Cardiff, United Kingdom.
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41
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Abstract
We describe the rapid single-step detection, by mutagenically separated polymerase chain reaction (MS-PCR), of the HLE C282Y mutation, for which > 90% of haemochromatosis patients in the U.K. are homozygous. In addition to using purified DNA as a template, whole blood and lysed buccal cell extracts from mouthwash samples can be used. Therefore sample collection may be non-invasive and purification steps kept to a minimum.
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Affiliation(s)
- A T Merryweather-Clarke
- MRC Unit of Molecular Haematology, Institute of Molecular Medicine, John Radcliffe Hospital, Oxford
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42
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Sultan AA, Thathy V, Frevert U, Robson KJ, Crisanti A, Nussenzweig V, Nussenzweig RS, Ménard R. TRAP is necessary for gliding motility and infectivity of plasmodium sporozoites. Cell 1997; 90:511-22. [PMID: 9267031 DOI: 10.1016/s0092-8674(00)80511-5] [Citation(s) in RCA: 458] [Impact Index Per Article: 17.0] [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: 02/05/2023]
Abstract
Many protozoans of the phylum Apicomplexa are invasive parasites that exhibit a substrate-dependent gliding motility. Plasmodium (malaria) sporozoites, the stage of the parasite that invades the salivary glands of the mosquito vector and the liver of the vertebrate host, express a surface protein called thrombospondin-related anonymous protein (TRAP) that has homologs in other Apicomplexa. By gene targeting in a rodent Plasmodium, we demonstrate that TRAP is critical for sporozoite infection of the mosquito salivary glands and the rat liver, and is essential for sporozoite gliding motility in vitro. This suggests that in Plasmodium sporozoites, and likely in other Apicomplexa, gliding locomotion and cell invasion have a common molecular basis.
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Affiliation(s)
- A A Sultan
- Department of Pathology, Kaplan Cancer Center, New York University Medical Center, New York 10016, USA
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43
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44
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Aidoo M, Lalvani A, Whittle HC, Hill AV, Robson KJ. Recombinant vaccinia viruses for the characterization of Plasmodium falciparum-specific cytotoxic T lymphocytes: recognition of processed antigen despite limited re-stimulation efficacy. Int Immunol 1997; 9:731-7. [PMID: 9184918 DOI: 10.1093/intimm/9.5.731] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Cytotoxic T lymphocytes (CTL) have been implicated in immunity to Plasmodium falciparum infection and disease. We have previously described the use of peptides to define malaria-specific CTL epitopes. To determine whether these peptide epitopes are processed intracellularly from the whole antigen we have developed recombinant vaccinia viruses (rVV) expressing three malaria antigens: thrombospondin-related adhesive protein (TRAP), Pfs16 and the C-terminal half of liver-stage antigen (LSA)-1. Target cells infected with recombinant viruses were lysed by malaria-specific CTL from semi-immune African donors. We also tested the ability of cells infected with these recombinant vaccinia viruses to re-stimulate malaria-specific CTL in peripheral blood lymphocytes from malaria immune adults. Two other pox virus recombinants, NYVAC, an attenuated vaccinia virus, and ALVAC, a canarypox virus, both expressing malaria antigens were also evaluated for their ability to stimulate malaria-specific CTL in contrast to peptide, none of these viruses successfully re-stimulated CTL from the peripheral blood lymphocytes of semi-immune donors. The ability of human CTL from naturally exposed individuals to recognize processed antigen supports the relevance of these cells in protective immunity to malaria.
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MESH Headings
- Adult
- Animals
- Antigen Presentation
- Antigens, Protozoan/biosynthesis
- Antigens, Protozoan/metabolism
- Epitopes, T-Lymphocyte/immunology
- Humans
- Immunization, Secondary
- Lymphocyte Activation
- Malaria, Falciparum/immunology
- Malaria, Falciparum/virology
- Plasmodium falciparum/immunology
- Recombination, Genetic
- T-Lymphocytes, Cytotoxic/immunology
- T-Lymphocytes, Cytotoxic/parasitology
- T-Lymphocytes, Cytotoxic/virology
- Vaccinia virus/genetics
- Vaccinia virus/immunology
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Affiliation(s)
- M Aidoo
- Nuffield Department of Medicine, University of Oxford, John Radcliffe Hospital, Headington, UK
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45
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Abstract
Haemochromatosis is a genetic disease associated with progressive iron overload, and is common among populations of northern European origin. HLA-H is a recently reported candidate gene for this condition. Two mutations have been identified, a substitution of cysteine for tyrosine at amino acid 282 (C282Y, nucleotide 845) and of histidine for aspartate at amino acid 63 (H63D, nucleotide 187). Over 90% of UK haemochromatosis patients are homozygous for the C282Y mutation. We have examined 5956 chromosomes (2978 people) for the presence of HLA-H C282Y and H63D by PCR followed by restriction enzyme analysis. We have found world wide allele frequencies of 1.9% for C282Y and 8.1% for H63D. The highest frequencies were 10% for C282Y in 90 Irish chromosomes and 30.4% for H63D in 56 Basque chromosomes. C282Y was most frequent in northern European populations and absent from 1042 African chromosomes, 484 Asian chromosomes, and 644 Australasian chromosomes. The distribution of the C282Y mutation coincides with that of populations in which haemochromatosis has been reported and is consistent with the theory of a north European origin for the mutation. The H63D polymorphism is more widely distributed and its connection with haemochromatosis remains unclear.
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46
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Robson KJ, Shearman JD, Merryweather-Clarke AT, Pointon JJ, Rosenberg WM, Walker AP, Dooley JS, Bomford A, Raha-Chowdhury R, Worwood M. Haemochromatosis: a gene at last? J Med Genet 1997; 34:148-51. [PMID: 9039993 PMCID: PMC1050870 DOI: 10.1136/jmg.34.2.148] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [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]
Affiliation(s)
- K J Robson
- MRC Molecular Haematology Unit, Institute of Molecular Medicine, John Radcliffe Hospital, Oxford, UK
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47
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Robson KJ, Naitza S, Barker G, Sinden RE, Crisanti A. Cloning and expression of the thrombospondin related adhesive protein gene of Plasmodium berghei. Mol Biochem Parasitol 1997; 84:1-12. [PMID: 9041516 DOI: 10.1016/s0166-6851(96)02774-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [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
Sporozoite recognition of host cells is a key step in the life-cycle of malaria parasites. Two sporozoite proteins have so far been characterized in some detail, the circumsporozoite protein (CS) and thrombospondin related adhesive protein (TRAP). We report here the cloning and expression of the TRAP gene homologue from Plasmodium berghei, PbTRAP. The PbTRAP gene encodes a protein of 606 amino acids having a deduced molecular mass of 66 kDa. The overall structure is clearly that of the TRAP family having a signal sequence followed by an integrin A domain, a sulphatide binding motif, followed by a proline based repeat before a transmembrane domain and helical cytoplasmic tail. The observed molecular mass is almost 50% larger than expected, this can be explained almost entirely by the abnormal behaviour in SDS-PAGE of the proline based repeat. As would be expected PbTRAP shows greatest similarity with the P. yoelli TRAP homologue sporozoite surface protein 2 (SSP2) than with PfTRAP, the TRAP gene from P. falciparum. The pattern of expression is similar to that of SSP2.
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Affiliation(s)
- K J Robson
- MRC Molecular Haematology Unit, John Radcliffe Hospital, Headington, Oxford, United Kingdom
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48
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Li JL, Robson KJ, Chen JL, Targett GA, Baker DA. Pfmrk, a MO15-related protein kinase from Plasmodium falciparum. Gene cloning, sequence, stage-specific expression and chromosome localization. Eur J Biochem 1996; 241:805-13. [PMID: 8944769 DOI: 10.1111/j.1432-1033.1996.00805.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Cyclin-dependent kinases (Cdks) play a central role in the regulation of the eukaryotic cell cycle. A novel gene encoding a Cdk-like protein, Pfmrk, has been isolated from the human malaria parasite Plasmodium falciparum. The gene has no introns and comprises an open reading frame encoding a protein of 324 amino acids with a predicted molecular mass of 38 kDa. Database searches revealed a striking similarity to the Cdk subfamily with the highest similarity to human MO15 (Cdk7). The overall sequence of Pfmrk shares 62% similarity and 46% identity with human MO15, in comparison to the 49-58% similarity and 34-43% identity with other human Cdks. Pfmrk contains two unique inserts: one consisting of 5 amino acids just before the cyclin-binding motif and the other composed of 13 amino acids within the T-loop equivalent region. Southern blots of genomic DNA digests and chromosomal separations showed that Pfmrk is a single-copy gene conserved between several parasite strains and is located on chromosome 10. A 2500-nucleotide transcript of this gene is expressed predominantly in the sexual blood stages (gametocytes), suggesting that Pfmrk may be involved in sexual stage development.
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Affiliation(s)
- J L Li
- Department of Medical Parasitology, London School of Hygiene and Tropical Medicine, UK
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49
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Robson KJ, Kotre CJ, Faulkner K. An experimental investigation of the effect of light-box luminance on the detection of low contrast objects in mammography. Br J Radiol 1996; 69:153-9. [PMID: 8785644 DOI: 10.1259/0007-1285-69-818-153] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [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: 02/02/2023] Open
Abstract
It has been hypothesized that light-box luminance is an important factor in the detection of objects on radiographs. In this work, existing psychophysical data relating to the measurement of visual thresholds at various scene luminance levels are applied to the problem of the observation of radiographs on a light-box. These data suggest that for a given stimulus size, the threshold contrast varies little over several orders of magnitude of scene luminance. In a series of contrast detail experiments performed over a wide range of light-box luminances it has been demonstrated that the detection of low contrast objects on mammographic film is dominated by external noise, that is noise on the film, rather than the internal visual noise of the observer. It is therefore suggested that in mammography it is inappropriate to base recommendations for optimal values of light-box luminance on psychophysical studies of visual noise. It has been shown that commonly used light-box luminances are suitable for viewing mammograms at the higher average optical densities now being recommended, provided that precautions are taken to avoid glare and reflection.
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Affiliation(s)
- K J Robson
- Regional Medical Physics Department, Newcastle General Hospital, Newcastle upon Tyne UK
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50
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Raha-Chowdhury R, Bowen DJ, Stone C, Pointon JJ, Terwilliger JD, Shearman JD, Robson KJ, Bomford A, Worwood M. New polymorphic microsatellite markers place the haemochromatosis gene telomeric to D6S105. Hum Mol Genet 1995; 4:1869-74. [PMID: 8595409 DOI: 10.1093/hmg/4.10.1869] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The haemochromatosis gene (HFE) is linked to both HLA-A and D6S105 on the short arm of chromosome 6 but these markers are separated by approximately 2 Mb of DNA. Most chromosomes carrying HFE have a common haplotype which extends from HLA-A to D6S105 and includes HLA-F. To localise the gene more precisely we have examined 10 microsatellite markers extending over a genetic distance of approximately 5 cM from D6S265 (within 100 kb of HLA-A on the centromeric side) to D6S299 (telomeric). The order of markers is D6S265, HLA-F, D6S258, D6S306, CS3, D6S105, D6S464, CS5, D6S461 and D6S299. We confirm that haemochromatosis appears to originate from a founder mutation which has multiplied in the population through successive generations. This mutation is associated with the haplotype D6S306-5, CS3-3, D6S105-8, D6S464-9 and CS5-4 which is found on approximately 70% of HFE chromosomes. We have applied a new and powerful, likelihood analysis for linkage disequilibrium. The maximum value of lambda (proportion of total possible association between a marker and disease) is 0.74 for marker CS5 (allele 4). A multipoint analysis also gives a maximum likelihood near marker CS5. We conclude that the HFE gene is likely to be located telomeric of D6S105 and close to CS5.
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Affiliation(s)
- R Raha-Chowdhury
- Department of Haematology, University of Wales College of Medicine, Cardiff, UK
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