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Effect of dynamic position changes during colonoscope withdrawal: a meta-analysis of randomized controlled trials. Surg Endosc 2020; 35:1171-1181. [PMID: 32128607 DOI: 10.1007/s00464-020-07483-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 02/26/2020] [Indexed: 01/14/2023]
Abstract
BACKGROUND Colonoscopies are considered to be the primary screening test and gold standard test for colorectal cancer. Position changes during colonoscope withdrawal are believed to be associated with an increased adenoma detection rate (ADR) and polyp detection rate (PDR). However, previous results conflicted, and this study aimed to elucidate the effectiveness of dynamic position changes during colonoscope withdrawal. METHODS The relevant publications were identified by searching the medical databases. The primary outcomes were the ADR and PDR, which were pooled and analyzed. The secondary outcome was the withdrawal time. The studies that supplied the ADR and PDR for different segments of the colon were separated into subgroup analyses. RESULTS Five randomized controlled trials were eligible for analysis. The total ADR was higher with dynamic position changes than with a static position (odds ratio, [OR] 1.34; 95% confidence interval [CI] 1.13-1.59; p < 0.001), with low evidence of between-study heterogeneity (I2 = 0%). Although the total PDR was slightly higher with dynamic position changes than with a static position (OR 1.23; 95% CI 0.88-1.73), there difference was not statistically significant (p = 0.22). The withdrawal time was only increased by 0.47 min (95% CI - 0.11 to 1.06) with dynamic position changes, without statistical significance (p = 0.11). The subgroup analysis showed that the ADR and PDR for the transverse colon were higher with dynamic position changes, with pooled estimates of ADR (OR 1.72; 95% CI 1.02-2.88; p = 0.04) and PDR (OR 1.79; 95% CI 1.08-2.96; p = 0.02). CONCLUSION Dynamic position changes during colonoscope withdrawal increased the total ADR; however, no obvious increase was found in the total PDR. The withdrawal time was not significantly prolonged with dynamic position changes. Subgroup analysis showed that the ADR and PDR in the transverse colon were obviously improved with dynamic position changes.
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Rossi M, Baiardi S, Parchi P. Understanding Prion Strains: Evidence from Studies of the Disease Forms Affecting Humans. Viruses 2019; 11:E309. [PMID: 30934971 PMCID: PMC6520670 DOI: 10.3390/v11040309] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2019] [Revised: 03/25/2019] [Accepted: 03/26/2019] [Indexed: 12/11/2022] Open
Abstract
Prion diseases are a unique group of rare neurodegenerative disorders characterized by tissue deposition of heterogeneous aggregates of abnormally folded protease-resistant prion protein (PrPSc), a broad spectrum of disease phenotypes and a variable efficiency of disease propagation in vivo. The dominant clinicopathological phenotypes of human prion disease include Creutzfeldt⁻Jakob disease, fatal insomnia, variably protease-sensitive prionopathy, and Gerstmann⁻Sträussler⁻Scheinker disease. Prion disease propagation into susceptible hosts led to the isolation and characterization of prion strains, initially operatively defined as "isolates" causing diseases with distinctive characteristics, such as the incubation period, the pattern of PrPSc distribution, and the regional severity of neuropathological changes after injection into syngeneic hosts. More recently, the structural basis of prion strains has been linked to amyloid polymorphs (i.e., variant amyloid protein conformations) and the concept extended to all protein amyloids showing polymorphic structures and some evidence of in vivo or in vitro propagation by seeding. Despite the significant advances, however, the link between amyloid structure and disease is not understood in many instances. Here we reviewed the most significant contributions of human prion disease studies to current knowledge of the molecular basis of phenotypic variability and the prion strain phenomenon and underlined the unsolved issues from the human disease perspective.
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Affiliation(s)
- Marcello Rossi
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), University of Bologna, Bologna 40138, Italy.
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna 40139, Italy.
| | - Simone Baiardi
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna 40123, Italy.
| | - Piero Parchi
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna 40139, Italy.
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), University of Bologna, Bologna 40138, Italy.
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Joiner S, Asante EA, Linehan JM, Brock L, Brandner S, Bellworthy SJ, Simmons MM, Hope J, Collinge J, Wadsworth JDF. Experimental sheep BSE prions generate the vCJD phenotype when serially passaged in transgenic mice expressing human prion protein. J Neurol Sci 2017; 386:4-11. [PMID: 29406965 PMCID: PMC5946165 DOI: 10.1016/j.jns.2017.12.038] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 12/01/2017] [Accepted: 12/28/2017] [Indexed: 11/02/2022]
Abstract
The epizootic prion disease of cattle, bovine spongiform encephalopathy (BSE), causes variant Creutzfeldt-Jakob disease (vCJD) in humans following dietary exposure. While it is assumed that all cases of vCJD attributed to a dietary aetiology are related to cattle BSE, sheep and goats are susceptible to experimental oral challenge with cattle BSE prions and farmed animals in the UK were undoubtedly exposed to BSE-contaminated meat and bone meal during the late 1980s and early 1990s. Although no natural field cases of sheep BSE have been identified, it cannot be excluded that some BSE-infected sheep might have entered the European human food chain. Evaluation of the zoonotic potential of sheep BSE prions has been addressed by examining the transmission properties of experimental brain isolates in transgenic mice that express human prion protein, however to-date there have been relatively few studies. Here we report that serial passage of experimental sheep BSE prions in transgenic mice expressing human prion protein with methionine at residue 129 produces the vCJD phenotype that mirrors that seen when the same mice are challenged with vCJD prions from patient brain. These findings are congruent with those reported previously by another laboratory, and thereby strongly reinforce the view that sheep BSE prions could have acted as a causal agent of vCJD within Europe.
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Affiliation(s)
- Susan Joiner
- MRC Prion Unit at UCL, UCL Institute of Prion Diseases, London, UK
| | | | | | - Lara Brock
- MRC Prion Unit at UCL, UCL Institute of Prion Diseases, London, UK
| | | | | | | | - James Hope
- Animal and Plant Health Agency, Addlestone, Surrey, UK
| | - John Collinge
- MRC Prion Unit at UCL, UCL Institute of Prion Diseases, London, UK
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4
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Ellett LJ, Lawson VA. Preparation and Immunostaining of the Myenteric Plexus of Prion-Infected Mice. Methods Mol Biol 2017; 1658:285-292. [PMID: 28861796 DOI: 10.1007/978-1-4939-7244-9_19] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Intracerebral inoculation of mice with the M1000 strain of mouse-adapted human prions results in the consistent accumulation of PrPSc in the ileum of the gastrointestinal tract (GIT) of mice with clinical signs of prion disease. The accumulation of PrPSc in the ileum is accompanied by caspase activation and loss of immunoreactivity in subpopulations of neurons in the enteric nervous system. This suggests that like neurons in the central nervous system, cells in the enteric nervous system are also susceptible to prion-induced toxicity. In this chapter we describe the immunostaining of cells in myenteric plexus preparations of whole mounts prepared from the gastrointestinal tract of prion-infected mice.
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Affiliation(s)
- Laura J Ellett
- Department of Pathology, The University of Melbourne, Medical Building, Parkville, VIC, 3010, Australia
| | - Victoria A Lawson
- Department of Pathology, The University of Melbourne, Medical Building, Parkville, VIC, 3010, Australia.
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5
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Transmissible Spongiform Encephalopathies of Humans and Animals. Infect Dis (Lond) 2017. [DOI: 10.1016/b978-0-7020-6285-8.00023-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Wadsworth JDF, Adamson G, Joiner S, Brock L, Powell C, Linehan JM, Beck JA, Brandner S, Mead S, Collinge J. Methods for Molecular Diagnosis of Human Prion Disease. Methods Mol Biol 2017; 1658:311-346. [PMID: 28861799 DOI: 10.1007/978-1-4939-7244-9_22] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Human prion diseases are associated with a range of clinical presentations, and they are classified by both clinicopathological syndrome and etiology, with subclassification according to molecular criteria. Here, we describe updated procedures that are currently used within the MRC Prion Unit at UCL to determine a molecular diagnosis of human prion disease. Sequencing of the PRNP open reading frame to establish the presence of pathogenic mutations is described, together with detailed methods for immunoblot or immunohistochemical determination of the presence of abnormal prion protein in the brain or peripheral tissues.
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Affiliation(s)
- Jonathan D F Wadsworth
- MRC Prion Unit at UCL, UCL Institute of Prion Diseases, Queen Square, London, WC1N 3BG, UK.
| | - Gary Adamson
- MRC Prion Unit at UCL, UCL Institute of Prion Diseases, Queen Square, London, WC1N 3BG, UK
| | - Susan Joiner
- MRC Prion Unit at UCL, UCL Institute of Prion Diseases, Queen Square, London, WC1N 3BG, UK
| | - Lara Brock
- MRC Prion Unit at UCL, UCL Institute of Prion Diseases, Queen Square, London, WC1N 3BG, UK
| | - Caroline Powell
- MRC Prion Unit at UCL, UCL Institute of Prion Diseases, Queen Square, London, WC1N 3BG, UK
| | - Jacqueline M Linehan
- MRC Prion Unit at UCL, UCL Institute of Prion Diseases, Queen Square, London, WC1N 3BG, UK
| | - Jonathan A Beck
- MRC Prion Unit at UCL, UCL Institute of Prion Diseases, Queen Square, London, WC1N 3BG, UK
| | - Sebastian Brandner
- MRC Prion Unit at UCL, UCL Institute of Prion Diseases, Queen Square, London, WC1N 3BG, UK
| | - Simon Mead
- MRC Prion Unit at UCL, UCL Institute of Prion Diseases, Queen Square, London, WC1N 3BG, UK
| | - John Collinge
- MRC Prion Unit at UCL, UCL Institute of Prion Diseases, Queen Square, London, WC1N 3BG, UK
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Bradford BM, Piccardo P, Ironside JW, Mabbott NA. Human prion diseases and the risk of their transmission during anatomical dissection. Clin Anat 2014; 27:821-32. [PMID: 24740900 DOI: 10.1002/ca.22403] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Accepted: 04/01/2014] [Indexed: 01/09/2023]
Abstract
Prion diseases (or transmissible spongiform encephalopathies) are a unique group of fatal progressive neurodegenerative diseases of the central nervous system. The infectious agent is hypothesized to consist solely of a highly protease-resistant misfolded isoform of the host prion protein. Prions display a remarkable degree of resistance to chemical and physical decontamination. Many common forms of decontamination or neutralization used in infection control are ineffective against prions, except chaotropic agents that specifically disrupt proteins. Human cadaveric prosection or dissection for the purposes of teaching and demonstration of human anatomy has a distinguished history and remains one of the fundamentals of medical education. Iatrogenic transmission of human prion diseases has been demonstrated from the inoculation or implantation of human tissues. Therefore, although the incidence of human prion diseases is rare, restrictions exist upon the use of tissues from patients reported with dementia, specifically the brain and other central nervous system material. A current concern is the potential for asymptomatic variant Creutzfeldt-Jakob disease transmission within the UK population. Therefore, despite the preventative measures, the transmission of prion disease through human tissues remains a potential risk to those working with these materials. In this review, we aim to summarize the current knowledge on human prion disease relevant to those working with human tissues in the context of anatomical dissection.
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Affiliation(s)
- Barry M Bradford
- The Roslin Institute and R(D)SVS The University of Edinburgh, Midlothian EH25 9RG, United Kingdom
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Affiliation(s)
- V. Beringue
- UR892 Virologie et Immunologie Moléculaires Centre de Recherche de Jouy-en-Josas F-78352 Jouy-en-Josas, France
| | - O. Andreoletti
- UMR INRA ENVT 1225, Interactions Hôtes Agents Pathogènes, Ecole Nationale Vétérinaire de Toulouse, 23 Chemin des Capelles 31076 Toulouse, France
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Jackson GS, Mead S, Collinge J. Developing early diagnostics for prion diseases. Neurodegener Dis Manag 2013. [DOI: 10.2217/nmt.12.76] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
SUMMARY The diagnosis of prion disease is typically made late in the clinical course, by which time patients are in an advanced state of neurological decline. This is despite the presence of pathology in many tissues, particularly those of the lymphoreticular and central nervous systems. The recent description of an effective blood assay for variant Creutzfeldt-Jakob disease clearly demonstrates the potential for routine pre-mortem diagnosis, although further progress is required for the detection of sporadic forms of the disease.
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Affiliation(s)
- Graham S Jackson
- MRC Prion Unit, Department of Neurodegenerative Disease, University College London Institute of Neurology, Queen Square, London, WC1N 3BG, UK
| | - Simon Mead
- MRC Prion Unit, Department of Neurodegenerative Disease, University College London Institute of Neurology, Queen Square, London, WC1N 3BG, UK
- National Prion Clinic, National Hospital for Neurology & Neurosurgery, Queen Square, London, WC1N 3BG, UK
| | - John Collinge
- MRC Prion Unit, Department of Neurodegenerative Disease, University College London Institute of Neurology, Queen Square, London, WC1N 3BG, UK
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Kirby E, Dickinson J, Vassey M, Dennis M, Cornwall M, McLeod N, Smith A, Marsh PD, Walker JT, Sutton JM, Raven NDH. Bioassay studies support the potential for iatrogenic transmission of variant Creutzfeldt Jakob Disease through dental procedures. PLoS One 2012; 7:e49850. [PMID: 23226225 PMCID: PMC3511499 DOI: 10.1371/journal.pone.0049850] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2012] [Accepted: 10/15/2012] [Indexed: 11/18/2022] Open
Abstract
Background Evidence is required to quantify the potential risks of transmission of variant Creutzfeldt Jakob (vCJD) through dental procedures. Studies, using animal models relevant to vCJD, were performed to address two questions. Firstly, whether oral tissues could become infectious following dietary exposure to BSE? Secondly, would a vCJD-contaminated dental instrument be able to transmit disease to another patient? Methods BSE-301V was used as a clinically relevant model for vCJD. VM-mice were challenged by injection of infected brain homogenate into the small intestine (Q1) or by five minute contact between a deliberately-contaminated dental file and the gingival margin (Q2). Ten tissues were collected from groups of challenged mice at three or four weekly intervals, respectively. Each tissue was pooled, homogenised and bioassayed in indicator mice. Findings Challenge via the small intestine gave a transmission rate of 100% (mean incubation 157±17 days). Infectivity was found in both dental pulp and the gingival margin within 3 weeks of challenge and was observed in all tissues tested within the oral cavity before the appearance of clinical symptoms. Following exposure to deliberately contaminated dental files, 97% of mice developed clinical disease (mean incubation 234±33 days). Interpretation Infectivity was higher than expected, in a wider range of oral tissues, than was allowed for in previous risk assessments. Disease was transmitted following transient exposure of the gingiva to a contaminated dental file. These observations provide evidence that dental procedures could be a route of cross-infection for vCJD and support the enforcement of single-use for certain dental instruments.
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Affiliation(s)
- Elizabeth Kirby
- Health Protection Agency - Porton Down, Salisbury, Wiltshire, United Kingdom
| | - Joanne Dickinson
- Health Protection Agency - Porton Down, Salisbury, Wiltshire, United Kingdom
| | - Matthew Vassey
- Health Protection Agency - Porton Down, Salisbury, Wiltshire, United Kingdom
| | - Mike Dennis
- Health Protection Agency - Porton Down, Salisbury, Wiltshire, United Kingdom
| | - Mark Cornwall
- Health Protection Agency - Porton Down, Salisbury, Wiltshire, United Kingdom
| | - Neil McLeod
- Health Protection Agency - Porton Down, Salisbury, Wiltshire, United Kingdom
| | - Andrew Smith
- College of Medical, Veterinary & Life Sciences, Glasgow Dental Hospital & School, University of Glasgow, Glasgow, United Kingdom
| | - Philip D. Marsh
- Health Protection Agency - Porton Down, Salisbury, Wiltshire, United Kingdom
- Leeds Dental Institute, Leeds, West Yorkshire, United Kingdom
| | - James T. Walker
- Health Protection Agency - Porton Down, Salisbury, Wiltshire, United Kingdom
| | - J. Mark Sutton
- Health Protection Agency - Porton Down, Salisbury, Wiltshire, United Kingdom
- * E-mail:
| | - Neil D. H. Raven
- Health Protection Agency - Porton Down, Salisbury, Wiltshire, United Kingdom
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11
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Edgeworth JA, Farmer M, Sicilia A, Tavares P, Beck J, Campbell T, Lowe J, Mead S, Rudge P, Collinge J, Jackson GS. Detection of prion infection in variant Creutzfeldt-Jakob disease: a blood-based assay. Lancet 2011; 377:487-93. [PMID: 21295339 DOI: 10.1016/s0140-6736(10)62308-2] [Citation(s) in RCA: 133] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND Variant Creutzfeldt-Jakob disease (vCJD) is a fatal neurodegenerative disorder originating from exposure to bovine-spongiform-encephalopathy-like prions. Prion infections are associated with long and clinically silent incubations. The number of asymptomatic individuals with vCJD prion infection is unknown, posing risk to others via blood transfusion, blood products, organ or tissue grafts, and contaminated medical instruments. We aimed to establish the sensitivity and specificity of a blood-based assay for detection of vCJD prion infection. METHODS We developed a solid-state binding matrix to capture and concentrate disease-associated prion proteins and coupled this method to direct immunodetection of surface-bound material. Quantitative assay sensitivity was assessed with a serial dilution series of 10⁻⁷ to 10⁻¹⁰ of vCJD prion-infected brain homogenate into whole human blood, with a baseline control of normal human brain homogenate in whole blood (10⁻⁶). To establish the sensitivity and specificity of the assay for detection of endogenous vCJD, we analysed a masked panel of 190 whole blood samples from 21 patients with vCJD, 27 with sporadic CJD, 42 with other neurological diseases, and 100 normal controls. Samples were masked and numbered by individuals independent of the assay and analysis. Each sample was tested twice in independent assay runs; only samples that were reactive in both runs were scored as positive overall. FINDINGS We were able to distinguish a 10⁻¹⁰ dilution of exogenous vCJD prion-infected brain from a 10⁻⁶ dilution of normal brain (mean chemiluminescent signal, 1·3×10⁵ [SD 1·1×10⁴] for vCJD vs 9·9×10⁴ [4·5×10³] for normal brain; p<0·0001)—an assay sensitivity that was orders of magnitude higher than any previously reported. 15 samples in the masked panel were scored as positive. All 15 samples were from patients with vCJD, showing an assay sensitivity for vCJD of 71·4% (95% CI 47·8–88·7) and a specificity of 100% (95% CIs between 97·8% and 100%). INTERPRETATION These initial studies provide a prototype blood test for diagnosis of vCJD in symptomatic individuals, which could allow development of large-scale screening tests for asymptomatic vCJD prion infection. FUNDING UK Medical Research Council.
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Affiliation(s)
- Julie Ann Edgeworth
- MRC Prion Unit, Department of Neurodegenerative Disease, UCL Institute of Neurology, London, UK
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Wadsworth JDF, Collinge J. Molecular pathology of human prion disease. Acta Neuropathol 2011; 121:69-77. [PMID: 20694796 PMCID: PMC3015177 DOI: 10.1007/s00401-010-0735-5] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2010] [Revised: 07/29/2010] [Accepted: 07/30/2010] [Indexed: 11/28/2022]
Abstract
Human prion diseases are associated with a range of clinical presentations and are classified by both clinicopathological syndrome and aetiology with sub-classification according to molecular criteria. Considerable experimental evidence suggests that phenotypic diversity in human prion disease relates in significant part to the existence of distinct human prion strains encoded by abnormal PrP isoforms with differing physicochemical properties. To date, however, the conformational repertoire of pathological isoforms of wild-type human PrP and the various forms of mutant human PrP has not been fully defined. Efforts to produce a unified international classification of human prion disease are still ongoing. The ability of genetic background to influence prion strain selection together with knowledge of numerous other factors that may influence clinical and neuropathological presentation strongly emphasises the requirement to identify distinct human prion strains in appropriate transgenic models, where host genetic variability and other modifiers of phenotype are removed. Defining how many human prion strains exist allied with transgenic modelling of potentially zoonotic prion strains will inform on how many human infections may have an animal origin. Understanding these relationships will have direct translation to protecting public health.
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Affiliation(s)
- Jonathan D. F. Wadsworth
- MRC Prion Unit, Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG UK
| | - John Collinge
- MRC Prion Unit, Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG UK
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Wadsworth JDF, Dalmau-Mena I, Joiner S, Linehan JM, O'Malley C, Powell C, Brandner S, Asante EA, Ironside JW, Hilton DA, Collinge J. Effect of fixation on brain and lymphoreticular vCJD prions and bioassay of key positive specimens from a retrospective vCJD prevalence study. J Pathol 2010; 223:511-8. [PMID: 21294124 DOI: 10.1002/path.2821] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Revised: 10/21/2010] [Accepted: 11/06/2010] [Indexed: 11/11/2022]
Abstract
Anonymous screening of lymphoreticular tissues removed during routine surgery has been applied to estimate the UK population prevalence of asymptomatic vCJD prion infection. The retrospective study of Hilton et al (J Pathol 2004; 203: 733-739) found accumulation of abnormal prion protein in three formalin-fixed appendix specimens. This led to an estimated UK prevalence of vCJD infection of ∼1 in 4000, which remains the key evidence supporting current risk reduction measures to reduce iatrogenic transmission of vCJD prions in the UK. Confirmatory testing of these positives has been hampered by the inability to perform immunoblotting of formalin-fixed tissue. Animal transmission studies offer the potential for 'gold standard' confirmatory testing but are limited by both transmission barrier effects and known effects of fixation on scrapie prion titre in experimental models. Here we report the effects of fixation on brain and lymphoreticular human vCJD prions and comparative bioassay of two of the three prevalence study formalin-fixed, paraffin-embedded (FFPE) appendix specimens using transgenic mice expressing human prion protein (PrP). While transgenic mice expressing human PrP 129M readily reported vCJD prion infection after inoculation with frozen vCJD brain or appendix, and also FFPE vCJD brain, no infectivity was detected in FFPE vCJD spleen. No prion transmission was observed from either of the FFPE appendix specimens. The absence of detectable infectivity in fixed, known positive vCJD lymphoreticular tissue precludes interpreting negative transmissions from vCJD prevalence study appendix specimens. In this context, the Hilton et al study should continue to inform risk assessment pending the outcome of larger-scale studies on discarded surgical tissues and autopsy samples.
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Affiliation(s)
- Jonathan D F Wadsworth
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
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Edgeworth JA, Sicilia A, Linehan J, Brandner S, Jackson GS, Collinge J. A standardized comparison of commercially available prion decontamination reagents using the Standard Steel-Binding Assay. J Gen Virol 2010; 92:718-26. [PMID: 21084494 PMCID: PMC3081234 DOI: 10.1099/vir.0.027201-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Prions are comprised principally of aggregates of a misfolded host protein and cause fatal transmissible neurodegenerative disorders of mammals, such as variant Creutzfeldt-Jakob disease in humans and bovine spongiform encephalopathy in cattle. Prions pose significant public health concerns through contamination of blood products and surgical instruments, and can resist conventional hospital sterilization methods. Prion infectivity binds avidly to surgical steel and can efficiently transfer infectivity to a suitable host, and much research has been performed to achieve effective prion decontamination of metal surfaces. Here, we exploit the highly sensitive Standard Steel-Binding Assay (SSBA) to perform a direct comparison of a variety of commercially available decontamination reagents marketed for the removal of prions, alongside conventional sterilization methods. We demonstrate that the efficacy of marketed prion decontamination reagents is highly variable and that the SSBA is able to rapidly evaluate current and future decontamination reagents.
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Affiliation(s)
- Julie Ann Edgeworth
- MRC Prion Unit, Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK
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de Marco MF, Linehan J, Gill ON, Clewley JP, Brandner S. Large-scale immunohistochemical examination for lymphoreticular prion protein in tonsil specimens collected in Britain. J Pathol 2010; 222:380-7. [DOI: 10.1002/path.2767] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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16
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Sandberg MK, Al-Doujaily H, Sigurdson CJ, Glatzel M, O'Malley C, Powell C, Asante EA, Linehan JM, Brandner S, Wadsworth JDF, Collinge J. Chronic wasting disease prions are not transmissible to transgenic mice overexpressing human prion protein. J Gen Virol 2010; 91:2651-7. [PMID: 20610667 PMCID: PMC3052602 DOI: 10.1099/vir.0.024380-0] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Chronic wasting disease (CWD) is a prion disease that affects free-ranging and captive cervids, including mule deer, white-tailed deer, Rocky Mountain elk and moose. CWD-infected cervids have been reported in 14 USA states, two Canadian provinces and in South Korea. The possibility of a zoonotic transmission of CWD prions via diet is of particular concern in North America where hunting of cervids is a popular sport. To investigate the potential public health risks posed by CWD prions, we have investigated whether intracerebral inoculation of brain and spinal cord from CWD-infected mule deer transmits prion infection to transgenic mice overexpressing human prion protein with methionine or valine at polymorphic residue 129. These transgenic mice have been utilized in extensive transmission studies of human and animal prion disease and are susceptible to BSE and vCJD prions, allowing comparison with CWD. Here, we show that these mice proved entirely resistant to infection with mule deer CWD prions arguing that the transmission barrier associated with this prion strain/host combination is greater than that observed with classical BSE prions. However, it is possible that CWD may be caused by multiple prion strains. Further studies will be required to evaluate the transmission properties of distinct cervid prion strains as they are characterized.
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Affiliation(s)
- Malin K Sandberg
- MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
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Howlin R, Khammo N, Secker T, McDonnell G, Keevil C. Application of a fluorescent dual stain to assess decontamination of tissue protein and prion amyloid from surgical stainless steel during simulated washer-disinfector cycles. J Hosp Infect 2010; 75:66-71. [DOI: 10.1016/j.jhin.2009.12.023] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2009] [Accepted: 12/24/2009] [Indexed: 10/19/2022]
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Rogez-Kreuz C, Yousfi R, Soufflet C, Quadrio I, Yan ZX, Huyot V, Aubenque C, Destrez P, Roth K, Roberts C, Favero M, Clayette P. Inactivation of animal and human prions by hydrogen peroxide gas plasma sterilization. Infect Control Hosp Epidemiol 2009; 30:769-77. [PMID: 19563265 DOI: 10.1086/598342] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Prions cause various transmissible spongiform encephalopathies. They are highly resistant to the chemical and physical decontamination and sterilization procedures routinely used in healthcare facilities. The decontamination procedures recommended for the inactivation of prions are often incompatible with the materials used in medical devices. In this study, we evaluated the use of low-temperature hydrogen peroxide gas plasma sterilization systems and other instrument-processing procedures for inactivating human and animal prions. We provide new data concerning the efficacy of hydrogen peroxide against prions from in vitro or in vivo tests, focusing on the following: the efficiency of hydrogen peroxide sterilization and possible interactions with enzymatic or alkaline detergents, differences in the efficiency of this treatment against different prion strains, and the influence of contaminating lipids. We found that gaseous hydrogen peroxide decreased the infectivity of prions and/or the level of the protease-resistant form of the prion protein on different surface materials. However, the efficiency of this treatment depended strongly on the concentration of hydrogen peroxide and the delivery system used in medical devices, because these effects were more pronounced for the new generation of Sterrad technology. The Sterrad NX sterilizer is 100% efficient (0% transmission and no protease-resistant form of the prion protein signal detected on the surface of the material for the mouse-adapted bovine spongiform encephalopathy 6PB1 strain and a variant Creutzfeldt-Jakob disease strain). Thus, gaseous or vaporized hydrogen peroxide efficiently inactivates prions on the surfaces of medical devices.
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Brandner S, Whitfield J, Boone K, Puwa A, O'Malley C, Linehan JM, Joiner S, Scaravilli F, Calder I, P Alpers M, Wadsworth JDF, Collinge J. Central and peripheral pathology of kuru: pathological analysis of a recent case and comparison with other forms of human prion disease. Philos Trans R Soc Lond B Biol Sci 2008; 363:3755-63. [PMID: 18849292 PMCID: PMC2581659 DOI: 10.1098/rstb.2008.0091] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
While the neuropathology of kuru is well defined, there are few data concerning the distribution of disease-related prion protein in peripheral tissues. Here we report the investigation of brain and peripheral tissues from a kuru patient who died in 2003. Neuropathological findings were compared with those seen in classical (sporadic and iatrogenic) Creutzfeldt–Jakob disease (CJD) and variant CJD (vCJD). The neuropathological findings of the kuru patient showed all the stereotypical changes that define kuru, with the occurrence of prominent PrP plaques throughout the brain. Lymphoreticular tissue showed no evidence of prion colonization, suggesting that the peripheral pathogenesis of kuru is similar to that seen in classical CJD rather than vCJD. These findings now strongly suggest that the characteristic peripheral pathogenesis of vCJD is determined by prion strain type alone rather than route of infection.
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Affiliation(s)
- Sebastian Brandner
- Department of Neurodegenerative Disease, MRC Prion Unit, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London, UK
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Kuru prions and sporadic Creutzfeldt-Jakob disease prions have equivalent transmission properties in transgenic and wild-type mice. Proc Natl Acad Sci U S A 2008; 105:3885-90. [PMID: 18316717 DOI: 10.1073/pnas.0800190105] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Kuru provides our principal experience of an epidemic human prion disease and primarily affected the Fore linguistic group of the Eastern Highlands of Papua New Guinea. Kuru was transmitted by the practice of consuming dead relatives as a mark of respect and mourning (transumption). To date, detailed information of the prion strain type propagated in kuru has been lacking. Here, we directly compare the transmission properties of kuru prions with sporadic, iatrogenic, and variant Creutzfeldt-Jakob disease (CJD) prions in Prnp-null transgenic mice expressing human prion protein and in wild-type mice. Molecular and neuropathological data from these transmissions show that kuru prions are distinct from variant CJD and have transmission properties equivalent to those of classical (sporadic) CJD prions. These findings are consistent with the hypothesis that kuru originated from chance consumption of an individual with sporadic CJD.
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Béringue V, Le Dur A, Tixador P, Reine F, Lepourry L, Perret-Liaudet A, Haïk S, Vilotte JL, Fontés M, Laude H. Prominent and persistent extraneural infection in human PrP transgenic mice infected with variant CJD. PLoS One 2008; 3:e1419. [PMID: 18183299 PMCID: PMC2171367 DOI: 10.1371/journal.pone.0001419] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2007] [Accepted: 12/17/2007] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The evolution of the variant Creutzfeldt-Jakob disease (vCJD) epidemic is hazardous to predict due to uncertainty in ascertaining the prevalence of infection and because the disease might remain asymptomatic or produce an alternate, sporadic-like phenotype. METHODOLOGY/PRINCIPAL FINDINGS Transgenic mice were produced that overexpress human prion protein with methionine at codon 129, the only allele found so far in vCJD-affected patients. These mice were infected with prions derived from variant and sporadic CJD (sCJD) cases by intracerebral or intraperitoneal route, and transmission efficiency and strain phenotype were analyzed in brain and spleen. We showed that i) the main features of vCJD infection in humans, including a prominent involvement of the lymphoid tissues compared to that in sCJD infection were faithfully reproduced in such mice; ii) transmission of vCJD agent by intracerebral route could lead to the propagation of either vCJD or sCJD-like prion in the brain, whereas vCJD prion was invariably propagated in the spleen, iii) after peripheral exposure, inefficient neuroinvasion was observed, resulting in an asymptomatic infection with life-long persistence of vCJD prion in the spleen at stable and elevated levels. CONCLUSION/SIGNIFICANCE Our findings emphasize the possibility that human-to-human transmission of vCJD might produce alternative neuropathological phenotypes and that lymphoid tissue examination of CJD cases classified as sporadic might reveal an infection by vCJD-type prions. They also provide evidence for the strong propensity of this agent to establish long-lasting, subclinical vCJD infection of lymphoreticular tissues, thus amplifying the risk for iatrogenic transmission.
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Affiliation(s)
- Vincent Béringue
- Institut Scientifique de Recherche Agronomique (INRA), UR892, Virologie Immunologie Moléculaires, Jouy-en-Josas, France
- * To whom correspondence should be addressed. E-mail: (HL); (VB)
| | - Annick Le Dur
- Institut Scientifique de Recherche Agronomique (INRA), UR892, Virologie Immunologie Moléculaires, Jouy-en-Josas, France
| | - Philippe Tixador
- Institut Scientifique de Recherche Agronomique (INRA), UR892, Virologie Immunologie Moléculaires, Jouy-en-Josas, France
| | - Fabienne Reine
- Institut Scientifique de Recherche Agronomique (INRA), UR892, Virologie Immunologie Moléculaires, Jouy-en-Josas, France
| | - Laurence Lepourry
- Institut Scientifique de Recherche Agronomique (INRA), UR339, Génétique Biochimique et Cytogénétique, Jouy-en-Josas, France
| | - Armand Perret-Liaudet
- Service de Neurobiologie, Centre de Biologie et Pathologie Est (CBPE), Groupement Hospitalier Est des Hôpitaux de Lyon, Bron, France
| | - Stéphane Haïk
- INSERM, Equipe Avenir, Maladies à Prions chez l'Homme, Paris, France
- Assistance Publique - Hôpitaux de Paris (AP-HP), Laboratoire de Neuropathologie R. Escourolle, Groupe Hospitalier Pitié- Salpétrière, Paris, France
| | - Jean-Luc Vilotte
- Institut Scientifique de Recherche Agronomique (INRA), UR339, Génétique Biochimique et Cytogénétique, Jouy-en-Josas, France
| | - Michel Fontés
- INSERM UMR 491-IPHM, Faculté de médecine de la Timone, Marseille, France
| | - Hubert Laude
- Institut Scientifique de Recherche Agronomique (INRA), UR892, Virologie Immunologie Moléculaires, Jouy-en-Josas, France
- * To whom correspondence should be addressed. E-mail: (HL); (VB)
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Wadsworth JDF, Powell C, Beck JA, Joiner S, Linehan JM, Brandner S, Mead S, Collinge J. Molecular diagnosis of human prion disease. Methods Mol Biol 2008; 459:197-227. [PMID: 18576157 DOI: 10.1007/978-1-59745-234-2_14] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Human prion diseases are associated with a range of clinical presentations, and they are classified by both clinicopathological syndrome and etiology, with subclassification according to molecular criteria. Here, we describe procedures that are used within the MRC Prion Unit to determine a molecular diagnosis of human prion disease. Sequencing of the PRNP open reading frame to establish the presence of pathogenic mutations is described, together with detailed methods for immunoblot or immunohistochemical determination of the presence of abnormal prion protein in brain or peripheral tissues.
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Glover DG, Pollard BJ, González L, Sisó S, Kennedy D, Jeffrey M. A non-invasive screen for infectivity in transmissible spongiform encephalopathies. Gut 2007; 56:1329-30. [PMID: 17698878 PMCID: PMC1954950 DOI: 10.1136/gut.2007.123141] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/08/2022]
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Powell N, Hayee BH, Yeoh DPK, Rowbotham DS, Saxena V, McNair A. Terminal ileal photography or biopsy to verify total colonoscopy: does the endoscope agree with the microscope? Gastrointest Endosc 2007; 66:320-5. [PMID: 17643707 DOI: 10.1016/j.gie.2007.02.039] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2006] [Accepted: 02/12/2007] [Indexed: 01/05/2023]
Abstract
BACKGROUND Various modalities exist to document the extent of colonoscopy, including a terminal ileum (TI) biopsy, which is considered the criterion standard by some authorities. A TI biopsy adds to procedure costs, is potentially hazardous, and the detection of pathology in routinely acquired biopsy specimens of a macroscopically normal TI is limited. A safer, less costly alternative for documenting total colonoscopy is desirable. OBJECTIVE To evaluate the effectiveness of TI photography as a means of documenting total colonoscopy. We also assessed the diagnostic yield of TI biopsies in patients with a macroscopically normal TI. DESIGN Prospective, observational study. SETTING District general hospital in the United Kingdom. PATIENTS A total of 232 unselected patients undergoing colonoscopy, TI intubation, photography, and biopsy. MAIN OUTCOME MEASUREMENTS Independent, experienced endoscopists were asked to state whether villi (and, therefore, TI entry) were "definitely," "probably," or "definitely not" depicted in TI photographs. This was compared with TI histology as a means of verifying total colonoscopy. The diagnostic yield of biopsy specimens from a macroscopically normal TI was determined. RESULTS Reviewers agreed that villi were "definitely present" in 93.8%, "probably present" in 5.9%, and "definitely not" present in 0.3% of cases, with excellent interobserver agreement (kappa value = 0.778, P < .0001). TI photographs "definitely" depicting villi (93.8%) did not differ significantly from histology confirming TI mucosa (96.1%, P = .285). Microscopic evidence of pathology was only detectable in 2.3% of patients with an endoscopically normal TI. CONCLUSIONS TI photography is an effective, safe, and cost-effective means of documenting total colonoscopy. Routine biopsy of a "normal" TI has a low diagnostic yield.
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Affiliation(s)
- Nick Powell
- Department of Gastroenterology, Queen Elizabeth Hospital, Woolwich, London, UK
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Wadsworth JDF, Collinge J. Update on human prion disease. Biochim Biophys Acta Mol Basis Dis 2007; 1772:598-609. [PMID: 17408929 DOI: 10.1016/j.bbadis.2007.02.010] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2006] [Accepted: 02/22/2007] [Indexed: 11/28/2022]
Abstract
The recognition that variant Creutzfeldt-Jakob disease (vCJD) is caused by the same prion strain as bovine spongiform encephalopathy in cattle has dramatically highlighted the need for a precise understanding of the molecular biology of human prion diseases. Detailed clinical, pathological and molecular data from a large number of human prion disease patients indicate that phenotypic diversity in human prion disease relates in part to the propagation of disease-related PrP isoforms with distinct physicochemical properties. Incubation periods of prion infection in humans can exceed 50 years and therefore it will be some years before the extent of any human vCJD epidemic can be predicted with confidence.
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Affiliation(s)
- Jonathan D F Wadsworth
- MRC Prion Unit and Department of Neurodegenerative Disease, Institute of Neurology, University College London, National Hospital for Neurology and Neurosurgery, Queen Square, London, UK
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26
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Abstract
Surveillance for infection by endoscopy for variant CJD and other human prion diseases
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Affiliation(s)
- M W Head
- National Creutzfeldt-Jakob Disease Surveillance Unit, School of Molecular and Clinical Medicine, University of Edinburgh, Western General Hospital, Edinburgh EH4 2XU, UK
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