201
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Thangathurai D, Roffey P, Mogos M, Riad M, Bohorguez A. Mediastinal haemorrhage mimicking tamponade during en-bloc oesophagectomy. Eur J Anaesthesiol 2005; 22:555-6. [PMID: 16045149 DOI: 10.1017/s0265021505240942] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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202
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Johnson RT, Gonzalez RG, Frosch MP. Case records of the Massachusetts General Hospital. Case 27-2005. An 80-year-old man with fatigue, unsteady gait, and confusion. N Engl J Med 2005; 353:1042-50. [PMID: 16148290 DOI: 10.1056/nejmcpc059024] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Richard T Johnson
- Department of Neurology, Microbiology, and Neuroscience, Johns Hopkins University School of Medicine and Bloomberg School of Public Health, Baltimore, USA
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203
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Cepek L, Steinacker P, Mollenhauer B, Wiese B, Ciesielczyk B, Bibl M, Wiltfang J, Zerr I, Schulz-Schaeffer W, Kretzschmar HA, Poser S, Otto M. Follow-up investigations of tau protein and S-100B levels in cerebrospinal fluid of patients with Creutzfeldt-Jakob disease. Dement Geriatr Cogn Disord 2005; 19:376-82. [PMID: 15802913 DOI: 10.1159/000084708] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/01/2004] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND S-100B and tau protein have a high differential diagnostic potential for the diagnosis of Creutzfeldt-Jakob disease (CJD). So far there has been only limited information available about the dynamics of these parameters in the cerebrospinal fluid (CSF). However, there is a special interest in finding biochemical markers to monitor disease progression for differential diagnosis and treatment. PATIENTS AND METHODS We analyzed CSF of 45 patients with CJD and of 45 patients with other neurological diseases for tau protein and S-100B in a follow-up setting. All diagnoses of CJD were later neuropathologically verified. A ratio between tau protein differences and the time between lumbar puncture was calculated. The same was done for S-100B. RESULTS Tau protein levels of 34 cases were above the cut-off level for CJD (>1,300 pg/ml) in the first CSF sample. In 7 of 11 patients with lower tau levels in the first CSF sample, tau levels rose. The above-mentioned ratio was significantly higher in the CJD group than in the group with other neurological diseases. Similar results were obtained for S-100B. CONCLUSION We conclude that follow-up investigations and calculation of ratios is a useful tool in the differential diagnosis of CJD. Variations in this pattern were observed in single cases.
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Affiliation(s)
- Lukas Cepek
- Department of Neurology, University of Gottingen, Gottingen, Germany
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204
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Pauli G. Tissue Safety in View of CJD and Variant CJD. Cell Tissue Bank 2005; 6:191-200. [PMID: 16151959 DOI: 10.1007/s10561-005-0336-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2005] [Accepted: 06/23/2005] [Indexed: 11/30/2022]
Abstract
Epidemiological studies on human transmissible spongiform encephalopathies (Creutzfeldt-Jakob Disease, CJD) have shown that the agent could be transmitted by highly infectious tissues like brain, spinal cord or retina and medicinal products derived from these tissues (i.e. human growth hormone, dura mater). A few cases of transmission of CJD by neurosurgical instruments have been reported. The transmission of the agent of variant CJD, which is suspected to be transmitted by BSE-contaminated food, by blood transfusion implies that in contrast to the agent of classical CJD this agent can also be transmitted by organs and tissues other than nerve tissues. Health authorities have implemented guidelines to reduce the risk of transmission of human and animal TSE by human and veterinary medicinal products. The high resistance of TSE agents against physical or chemical treatment hamper the development of highly efficient inactivation steps in the production of medicinal products. Donor selection is considered as an efficient measure to reduce the risk of TSE transmission. However, the development of rapid, sensitive and specific diagnostic test systems is urgently required to test blood, organs and tissue of donors.
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Affiliation(s)
- Georg Pauli
- Center for Biological Safety, Robert Koch-Institut, Nordufer 20, 13353 Berlin, Germany.
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205
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Abstract
Prions are infectious pathogens principally composed of abnormal forms of a protein encoded in the host genome. They cause lethal neurodegenerative conditions including CJD, GSS, and kuru in humans and scrapie and bovine spongiform encephalopathy in domestic animals. Remarkably, distinct strains of prions occur despite absence of an agent-specific genome: misfolded proteins themselves may encode strain diversity--with wide implications in biology. The arrival of variant CJD, and the experimental confirmation that it is caused by infection with BSE-like prions, has focussed research on early diagnosis and treatment. Recent advances lead to considerable optimism that effective human therapies may now be developed. While several drugs have been tried in small numbers of patients, there is no clear evidence of efficacy of any agent and controlled clinical trials are urgently needed. Importantly, there is increasing recognition that fundamental processes involved in prion propagation--seeded aggregation of misfolded host proteins--are of far wider significance, not least in understanding the commoner neurodegenerative diseases that pose such a major and increasing challenge for healthcare in an ageing population.
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Affiliation(s)
- J Collinge
- MRC Prion Unit and National Prion Clinic, Institute of Neurology and National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK.
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206
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Bannon L, Brimacombe J, Nixon T, Keller C. Repeat autoclaving does not remove protein deposits from the classic laryngeal mask airway. Eur J Anaesthesiol 2005; 22:515-7. [PMID: 16045140 DOI: 10.1017/s0265021505000888] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
INTRODUCTION We tested the hypothesis that repeated autoclaving removes protein deposits from the classic laryngeal mask airway (LMA). METHODS Twenty previously used LMAs were hand washed, machine washed, dried, autoclaved and randomly allocated into four equal-sized groups for repeat autoclaving on 0 (control), 1, 2 and 3 occasions. After the final autoclave cycle, the LMAs were immersed in a protein-staining solution, rinsed, dried and a high-resolution digital image taken of the dorsal and ventral surfaces. The severity of staining was scored by two blinded observers. RESULTS All LMAs were stained. There was no reduction in staining with repeat autoclaving. CONCLUSIONS Repeat autoclaving does not remove protein deposits from the LMA.
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Affiliation(s)
- L Bannon
- Cairns Base Hospital, Department of Anaesthesia and Intensive Care, Australia
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207
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Hirsch N, Beckett A, Collinge J, Scaravilli F, Tabrizi S, Berry S. Lymphocyte contamination of laryngoscope blades - a possible vector for transmission of variant Creutzfeldt-Jakob disease. Anaesthesia 2005; 60:664-7. [PMID: 15960716 DOI: 10.1111/j.1365-2044.2005.04221.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Variant Creutzfeldt-Jakob disease (vCJD) is associated with extensive prion infection of lymphoreticular tissues during the prolonged asymptomatic incubation period. Instruments exposed to infected tissues of preclinically infected individuals during medical or surgical procedures represent a potential risk of iatrogenic transmission of vCJD prions. We assessed the frequency of contamination with lymphoid tissue of single-use laryngoscope blades used for tracheal intubation for general anaesthesia. Using a cyto-centrifugation technique, lymphocytes were detected from 30% of laryngoscope blades studied. As prions resist routine sterilisation procedures, the use of non-disposable laryngoscope blades poses a risk of transmitting vCJD from patient to patient. The use of such instruments should be abandoned and disposable alternatives used.
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Affiliation(s)
- N Hirsch
- Department of Neuroanaesthesia, The National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK.
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208
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Abstract
Several prion disease-related human health risks from an exogenous source can be identified in the United States, including the iatrogenic transmission of Creutzfeldt-Jakob disease (CJD), the possible occurrence of variant CJD (vCJD), and potential zoonotic transmission of chronic wasting disease (CWD). Although cross-species transmission of prion diseases seems to be limited by an apparent "species barrier," the occurrence of bovine spongiform encephalopathy (BSE) and its transmission to humans indicate that animal prion diseases can pose a significant public health risk. Recent reports of secondary person-to-person spread of vCJD via blood products and detection of vCJD transmission in a patient heterozygous at codon 129 further illustrate the potential public health impacts of BSE.
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Affiliation(s)
- Ermias D Belay
- Division of Viral and Rickettsial Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA.
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209
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Olsen SB, Sheikh A, Peck D, Darzi A. Variant Creutzfeldt-Jakob disease: a cause for concern. Review of the evidence for risk of transmission through abdominal lymphoreticular tissue surgery. Surg Endosc 2005; 19:747-50. [PMID: 15868249 DOI: 10.1007/s00464-004-9205-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2004] [Accepted: 11/13/2004] [Indexed: 10/25/2022]
Abstract
BACKGROUND Concern has long existed regarding the possible iatrogenic spread of variant Creutzfeldt-Jakob disease (v-CJD) through surgery. This had been fueled by recent reports of bovine spongiform encephalopathy in U.S. cattle and the first probable case of blood transmission of v-CJD in the UK. METHODS Systematic review of experimental and nonexperimental studies. Studies identified from searches of Medline, Embase, Cochrane Library, Science Citation Index medical databases, searching bibliographies of retrieved papers, and personal communication with international experts in the field. RESULTS Six articles satisfied our search criteria. Evidence stems from case reports, case series, and cross-sectional studies. There are no published cases of surgically transmitted v-CJD. CONCLUSION We found evidence of v-CJD prion agents in the spleen, appendix, rectum, and adrenal glands of affected patients and evidence of v-CJD prion in the appendix of patients in the preclinical stage of the disease. The risk of transmission of v-CJD prion during abdominal surgery is currently unquantifiable.
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Affiliation(s)
- S B Olsen
- Department of Surgical Technology and Oncology, Imperial College of Science, Technology and Medicine, St. Mary's Hospital, London W2 1NY, United Kingdom.
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210
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Halliday S, Houston F, Hunter N. Expression of PrPC on cellular components of sheep blood. J Gen Virol 2005; 86:1571-1579. [PMID: 15831971 DOI: 10.1099/vir.0.80561-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
PrPC, a glycosylphosphatidylinositol-linked glycoprotein, plays a central role in the pathogenesis of transmissible spongiform encephalopathies (TSEs), undergoing a conformational alteration to the disease-associated isoform, commonly designated PrPSc. PrPC is expressed in many tissues other than the nervous system, although its precise function(s) remains unclear. It has previously been demonstrated that TSEs can be transmitted by blood transfusion in sheep. The aim of this work was to identify which components of blood carried the infection. As an initial step, the distribution of PrPC on cellular components of sheep blood was examined to identify potential targets for infection. Cell-surface expression of PrPC was found only on peripheral blood mononuclear cells (PBMCs); however, platelets also contained significant amounts of intracellular PrPC. The level of PrPC expressed on the cell surface of PBMCs was influenced by PrP genotype, with the highest levels found in scrapie-susceptible VRQ/VRQ sheep and the lowest levels in scrapie-resistant ARR/ARR sheep. In susceptible sheep, PrPC was expressed at varying levels on all major subsets of PBMCs, with the highest levels on the CD21+ subset of B cells, and PrP expression was upregulated dramatically on CD21+ B cells in some scrapie-infected sheep.
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Affiliation(s)
- S Halliday
- Institute for Animal Health, Compton, Newbury, Berkshire RG20 7NN, UK
| | - F Houston
- Institute for Animal Health, Compton, Newbury, Berkshire RG20 7NN, UK
| | - N Hunter
- Institute for Animal Health, Compton, Newbury, Berkshire RG20 7NN, UK
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211
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Abstract
PURPOSE OF REVIEW Prion diseases are transmissible fatal neurodegenerative disorders in which infectivity is associated with the accumulation of PrP(Sc), a disease-related isoform of normal cellular prion protein. The recent emergence of variant Creutzfeldt-Jakob disease has led to major public health concerns, and the need for the development of effective treatments. As PrP(Sc) is associated both with pathology and infectivity, therapeutic approaches to date have largely aimed at preventing its accumulation, but this strategy has produced only modest results in animal models. The link between PrP(Sc) and neurotoxicity is unclear, and alternative pathological processes need to be considered. Here we focus on the latest progress in therapeutic strategies and potential mechanisms of prion neurotoxicity. RECENT FINDINGS Passive immunisation with anti-prion protein antibodies prevents peripheral prion replication and blocks progression to clinical disease in peripherally infected mice. A new approach, in which neuronal cellular prion protein is depleted in mice with established neuroinvasive prion infection, prevents the onset of clinical disease, blocks neuronal cell loss and reverses early spongiform pathology. This dramatic protective effect occurs despite the continued build-up of extraneuronal PrP(Sc) and continued replication of prion infectivity, effectively producing a sub-clinical state. SUMMARY New insights into the mechanisms of neurotoxicity in prion diseases support the concept that PrP(Sc) itself is not directly neurotoxic. They suggest that neuronal prion propagation results in the production of a toxic intermediate or depletion of a key constituent. Prevention of the formation of such a species rather than PrP(Sc) accumulation itself is a clear target for prion therapeutics.
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Affiliation(s)
- Giovanna Mallucci
- MRC Prion Unit and Department of Neurodegenerative Disease, Institute of Neurology, National Hospital for Neurology and Neurosurgery, London WC1N 3BG, UK
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212
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Armstrong RA, Cairns NJ, Ironside JW, Lantos PL. Size frequency distribution of prion protein (PrP) aggregates in variant Creutzfeldt-Jakob disease (vCJD). J Neural Transm (Vienna) 2005; 112:1565-73. [PMID: 15785857 DOI: 10.1007/s00702-005-0296-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2004] [Accepted: 02/19/2005] [Indexed: 10/25/2022]
Abstract
The frequency distribution of aggregate size of the diffuse and florid-type prion protein (PrP) plaques was studied in various brain regions in cases of variant Creutzfeldt-Jakob disease (vCJD). The size distributions were unimodal and positively skewed and resembled those of beta-amyloid (A beta) deposits in Alzheimer's disease (AD) and Down's syndrome (DS). The frequency distributions of the PrP aggregates were log-normal in shape, but there were deviations from the expected number of plaques in specific size classes. More diffuse plaques were observed in the modal size class and fewer in the larger size classes than expected and more florid plaques were present in the larger size classes compared with the log-normal model. It was concluded that the growth of the PrP aggregates in vCJD does not strictly follow a log-normal model, diffuse plaques growing to within a more restricted size range and florid plaques to larger sizes than predicted.
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Affiliation(s)
- R A Armstrong
- Vision Sciences, Aston University, Birmingham, United Kingdom. R.A,
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213
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Khalili-Shirazi A, Quaratino S, Londei M, Summers L, Tayebi M, Clarke AR, Hawke SH, Jackson GS, Collinge J. Protein conformation significantly influences immune responses to prion protein. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2005; 174:3256-63. [PMID: 15749856 DOI: 10.4049/jimmunol.174.6.3256] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In prion diseases, such as variant Creutzfeldt-Jakob disease normal cellular prion protein (PrPC), a largely alpha-helical structure is converted to an abnormal conformational isoform (PrPSc) that shows an increase in beta-sheet content. Similarly, the recombinant form of PrPC (ralpha-PrP) can be converted to a conformation dominated by beta-sheet (rbeta-PrP) by reduction and mild acidification in vitro, a process that may mimic in vivo conversion following PrPC internalization during recycling. Despite PrPSc accumulation and prion propagation in the lymphoreticular system before detectable neuroinvasion, no Ab response to PrP has been detected, probably due to immune tolerance. To investigate how the immune system may respond to alpha- and beta-PrP, we immunized Prnp(0/0) mice that are not tolerant of PrP with ralpha-PrP and rbeta-PrP. In this study, we show that although T cells stimulated by these differently folded conformers PrP recognize similar immunodominant epitopes (residues 111-130 and 191-210) the cytokine profile in response to ralpha- and rbeta-PrP was different. Challenge with ralpha-PrP elicited a strong response of IL-5 and IL-10, whereas rbeta-PrP led to an early increased production of IFN-gamma. In addition, immunization with ralpha-PrP led to production of predominantly IgG1 isotype Ab in the sera, whereas after immunization with rbeta-PrP, IgG2b was significantly produced. Thus, both humoral and cellular responses to these differently folded isoforms of the same protein are different, indicating a possible involvement of Th1 and Th2 pathway activation. These differences may be exploitable diagnostically and therapeutically for prion diseases, such as variant Creutzfeldt-Jakob disease.
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Affiliation(s)
- Azadeh Khalili-Shirazi
- Department of Neurodegenerative Disease, Institute of Neurology, University College London, London, United Kingdom
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214
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Mohan J, Bruce ME, Mabbott NA. Follicular dendritic cell dedifferentiation reduces scrapie susceptibility following inoculation via the skin. Immunology 2005; 114:225-34. [PMID: 15667567 PMCID: PMC1782078 DOI: 10.1111/j.1365-2567.2004.02074.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Transmissible spongiform encephalopathies (TSEs) are a group of subacute infectious neurodegenerative diseases that are characterized by the accumulation in affected tissues of PrP(Sc), an abnormal isoform of the host prion protein (PrPc). Following peripheral exposure, TSE infectivity and PrP(Sc) usually accumulate in lymphoid tissues prior to neuroinvasion. Studies in mice have shown that exposure through scarified skin is an effective means of TSE transmission. Following inoculation via the skin, a functional immune system is critical for the transmission of TSEs to the brain, but until now, it has not been known which components of the immune system are required for efficient neuroinvasion. Temporary dedifferentiation of follicular dendritic cells (FDCs) by treatment with an inhibitor of the lymphotoxin-beta receptor signalling pathway (LTbetaR-Ig) 3 days before or 14 days after inoculation via the skin, blocked the early accumulation of PrP(Sc) and TSE infectivity within the draining lymph node. Furthermore, in the temporary absence of FDCs before inoculation, disease susceptibility was reduced and survival time significantly extended. Treatment with LTbetaR-Ig 14 days after TSE inoculation also significantly extended the disease incubation period. However, treatment 42 days after inoculation did not affect disease susceptibility or survival time, suggesting that the infection may have already have spread to the nervous system. Together these data show that FDCs are essential for the accumulation of PrP(Sc) and infectivity within lymphoid tissues and subsequent neuroinvasion following TSE exposure via the skin.
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Affiliation(s)
- Joanne Mohan
- Institute for Animal Health, Ogston Building, Edinburgh, United Kingdom
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215
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216
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Féraudet C, Morel N, Simon S, Volland H, Frobert Y, Créminon C, Vilette D, Lehmann S, Grassi J. Screening of 145 Anti-PrP Monoclonal Antibodies for Their Capacity to Inhibit PrPSc Replication in Infected Cells. J Biol Chem 2005; 280:11247-58. [PMID: 15618225 DOI: 10.1074/jbc.m407006200] [Citation(s) in RCA: 254] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Prion diseases are transmissible neurodegenerative disorders affecting humans and animals for which no therapeutic or prophylactic regimens exist. During the last three years several studies have shown that anti-PrP monoclonal antibodies (mAbs) can antagonize prion propagation in vitro and in vivo, but the mechanisms of inhibition are not known so far. To identify the most powerful mAbs and characterize more precisely the therapeutic effect of anti-PrP antibodies, we have screened 145 different mAbs produced in our laboratory for their capacity to cure cells constitutively expressing PrPSc. Our results confirm for a very large series of antibodies that mAbs recognizing cell-surface native PrPc can efficiently clean and definitively cure infected cells. Antibodies having a cleaning effect are directed against linear epitopes located in at least four different regions of PrP, suggesting an epitope-independent inhibition mechanism. The consequence of antibody binding is the sequestration of PrPc at the cell surface, an increase of PrPc levels recovered in cell culture medium, and an internalization of antibodies. Taken together these data suggest that the cleaning process is more likely due to a global effect on the PrP trafficking and/or transconformation process. Two antibodies, Sha31 and BAR236, show an IC50 of 0.6 nM, thus appearing 10-fold more efficient than previous antibodies described in the literature. Finally, five co-treatments were also tested, and only one of them, described previously (SAF34 + SAF61), lowered PrPSc levels in the cells synergistically.
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Affiliation(s)
- Cécile Féraudet
- Commissariat à l'Energie Atomique (CEA), Service de Pharmacologie et d'Immunologie, CEA/Saclay, 91191 Gif sur Yvette, France
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217
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Jackson GS, McKintosh E, Flechsig E, Prodromidou K, Hirsch P, Linehan J, Brandner S, Clarke AR, Weissmann C, Collinge J. An enzyme-detergent method for effective prion decontamination of surgical steel. J Gen Virol 2005; 86:869-878. [PMID: 15722550 DOI: 10.1099/vir.0.80484-0] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Prions, transmissible agents that cause Creutzfeldt-Jakob disease (CJD) and other prion diseases, are known to resist conventional sterilization procedures. Iatrogenic transmission of classical CJD via neurosurgical instruments is well documented and the involvement of lymphoreticular tissues in variant CJD (vCJD), together with the unknown population prevalence of asymptomatic vCJD infection, has led to concerns about transmission from a wide range of surgical procedures. To address this problem, conditions were sought that destroy PrP(Sc) from vCJD-infected human tissue and eradicate RML prion infectivity adsorbed onto surgical steel. Seven proteolytic enzymes were evaluated individually and in pairs at a range of temperatures and pH values and the additional effects of detergents, lipases and metal ions were assessed. A combination of proteinase K and Pronase, in conjunction with SDS, was shown to degrade PrP(Sc) material from highly concentrated vCJD-infected brain preparations to a level below detection. When RML prion-infected wires were exposed to the same enzymic treatment, intracerebral bioassay in highly susceptible hosts showed virtually no infectivity. The prion-degrading reagents identified in this study are readily available, inexpensive, non-corrosive to instruments, non-hazardous to staff and compatible with current equipment and procedures used in hospital sterilization units.
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Affiliation(s)
- Graham S Jackson
- MRC Prion Unit, Department of Neurodegenerative Disease, Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK
| | - Edward McKintosh
- MRC Prion Unit, Department of Neurodegenerative Disease, Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK
| | - Eckhard Flechsig
- MRC Prion Unit, Department of Neurodegenerative Disease, Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK
| | - Kanella Prodromidou
- MRC Prion Unit, Department of Neurodegenerative Disease, Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK
| | - Petra Hirsch
- MRC Prion Unit, Department of Neurodegenerative Disease, Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK
| | - Jackie Linehan
- MRC Prion Unit, Department of Neurodegenerative Disease, Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK
| | - Sebastian Brandner
- MRC Prion Unit, Department of Neurodegenerative Disease, Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK
| | - Anthony R Clarke
- MRC Prion Unit, Department of Neurodegenerative Disease, Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK
| | - Charles Weissmann
- MRC Prion Unit, Department of Neurodegenerative Disease, Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK
| | - John Collinge
- MRC Prion Unit, Department of Neurodegenerative Disease, Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK
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218
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Vu T, Harris A, Gospodarevskaya E. Improved infection control in the prevention of variant Creutzfeldt-Jakob disease in Australia: costs and benefits. Aust N Z J Public Health 2005; 28:561-8. [PMID: 15707207 DOI: 10.1111/j.1467-842x.2004.tb00048.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
OBJECTIVE To evaluate the costs and benefits of infection control strategies to prevent the transmission of variant Creutzfeldt-Jakob disease (vCJD) in ophthalmic surgery in Australia. METHODS The reduction in the risk of iatrogenic transmission of vCJD from feasible infection control strategies was calculated using decision analytic models. A static model calculated the direct secondary transmission for surgical eye procedures, and a simple dynamic model estimated the change in the risk of a subsequent sustained epidemic over the longer term. The expected number of vCJD infections, their cost of care and years of life lost and the estimated cost of strategies included the direct costs of infection control measures were calculated taking a health system perspective. RESULTS The dynamic model (Markov process) predicted that from a hypothetical pool of as many as 100 primary vCJD cases there would be less than five iatrogenic infections in the next 30 years. If there are fewer than five primary cases the model predicted no secondary cases of vCJD. The costs of providing care for a vCJD case is estimated to be about $50,000, subject to considerable uncertainty. The minimum cost for using a partial infection control strategy to prevent an iatrogenic infection is likely to be in the order of several millions of dollars. CONCLUSIONS Substantial public health investment would need to be made in order to reduce a low risk of iatrogenic transmission of vCJD. Given the likely number of cases of iatrogenic infection, and the order of magnitude of the costs of caring for cases of vCJD, it may be difficult to justify the high cost of risk reduction strategies.
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Affiliation(s)
- Trang Vu
- Centre for Health Economics, Monash University, Victoria
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219
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Mohan J, Bruce ME, Mabbott NA. Neuroinvasion by scrapie following inoculation via the skin is independent of migratory Langerhans cells. J Virol 2005; 79:1888-97. [PMID: 15650212 PMCID: PMC544109 DOI: 10.1128/jvi.79.3.1888-1897.2005] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Many natural transmissible spongiform encephalopathy (TSE) infections are likely to be acquired peripherally, and studies in mice show that skin scarification is an effective means of scrapie transmission. After peripheral exposure, TSE agents usually accumulate in lymphoid tissues before spreading to the brain. The mechanisms of TSE transport to lymphoid tissues are not known. Langerhans cells (LCs) reside in the epidermis and migrate to the draining lymph node after encountering antigen. To investigate the potential role of LCs in scrapie transportation from the skin, we utilized mouse models in which their migration was blocked either due to CD40 ligand deficiency (CD40L-/- mice) or after caspase-1 inhibition. We show that the early accumulation of scrapie infectivity in the draining lymph node and subsequent neuroinvasion was not impaired in mice with blocked LC migration. Thus, LCs are not involved in TSE transport from the skin. After intracerebral inoculation with scrapie, wild-type mice and CD40L-/- mice develop clinical disease with similar incubation periods. However, after inoculation via skin scarification CD40L-/- mice develop disease significantly earlier than do wild-type mice. The shorter incubation period in CD40L-/- mice is unexpected and suggests that a CD40L-dependent mechanism is involved in impeding scrapie pathogenesis. In vitro studies demonstrated that LCs have the potential to acquire and degrade protease-resistant prion protein, which is thought to be a component of the infectious agent. Taken together, these data suggest that LCs are not involved in scrapie transport to draining lymphoid tissues but might have the potential to degrade scrapie in the skin.
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Affiliation(s)
- Joanne Mohan
- Neuropathogenesis Unit, Institute for Animal Health, Ogston Bldg., West Mains Rd., Edinburgh EH9 3JF, United Kingdom
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220
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Abstract
Prions--pathogens that are lethal to humans and other animals--are thought to be conformational isomers of the cellular prion protein. Their unique biology, and the potential for a wider pathobiological significance of prion-like mechanisms, has motivated much research into understanding prion neurodegeneration. Moreover, concerns that extensive dietary exposure to bovine spongiform encephalopathy (BSE) prions might have infected many individuals--who might eventually develop its human counterpart, variant Creutzfeldt-Jakob disease (vCJD)--has focused much interest on therapeutics. The challenge of interrupting this aggressive, diffuse and uniformly fatal neurodegenerative process is daunting. However, the recent finding that the onset of clinical disease in established neuroinvasive prion infection in a mouse model can be halted and early pathology reversed is a source for considerable optimism. A therapeutic focus on the cellular prion protein, rather than prions themselves, which might not be directly neurotoxic, is suggested.
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Affiliation(s)
- Giovanna Mallucci
- Medical Research Council Prion Unit and Department of Neurodegenerative Disease, Institute of Neurology, University College London, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
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221
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Hafezparast M, Brandner S, Linehan J, Martin JE, Collinge J, Fisher EMC. Prion disease incubation time is not affected in mice heterozygous for a dynein mutation. Biochem Biophys Res Commun 2005; 326:18-22. [PMID: 15567146 DOI: 10.1016/j.bbrc.2004.10.206] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2004] [Indexed: 11/13/2022]
Abstract
A mechanism for transmission of the infectious prions from the peripheral nerve ends to the central nervous system is thought to involve neuronal anterograde and retrograde transport systems. Cytoplasmic dynein is the major retrograde transport molecular motor whose function is impaired in the Legs at odd angles (Loa) mouse due to a point mutation in the cytoplasmic dynein heavy chain subunit. Loa is a dominant trait which causes neurodegeneration and progressive motor function deficit in the heterozygotes. To investigate the role of cytoplasmic dynein in the transmission of prions within neurons, we inoculated heterozygous Loa and wild type littermates with mouse-adapted scrapie prions intracerebrally and intraperitonially, and determined the incubation period to onset of clinical prion disease. Our data indicate that the dynein mutation in the heterozygous state does not affect prion disease incubation time or its neuropathology in Loa mice.
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Affiliation(s)
- Majid Hafezparast
- Department of Neurodegenerative Disease, Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK.
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222
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Abstract
Devising approaches to the therapy of transmissible spongiform encephalopathies, or prion diseases, is beset by many difficulties. For one, the nature of the infectious agent, the prion, is understood only in outline, and its composition, structure, and mode of replication are still shrouded in mystery. In addition, the mechanism of pathogenesis is not well understood. Because clinical disease affects mainly the brain parenchyme, therapeutic agents must be able to traverse the brain-blood barrier (BBB) or have to be introduced directly into the cerebrospinal fluid or brain tissue. And finally, because the disease is usually recognized only after onset of severe clinical symptoms, the question arises as to whether the neurodegenerative processes can be reversed to any extent after a successful eradication of the agent.
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Affiliation(s)
- Charles Weissmann
- Department of Neurodegenerative Disease/MRC Prion Unit, Institute of Neurology, Queen Square, London WC1N 3BG, UK.
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223
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Abstract
The germinal centre is a dynamic microenvironment where antigen-activated B cells rapidly expand and differentiate, generating plasma cells and memory B cells. These cellular events are accompanied by dramatic changes in the antibody molecules that undergo somatic hypermutation and isotype switching. Follicular dendritic cells (FDCs) are the stromal cells located in the germinal centre. Although the capacity of FDCs to present antigen to B cells through antigen-antibody complexes has been recognized for many years, additional critical functions of FDCs have only recently been recognized. FDCs prevent apoptosis of germinal centre B cells and stimulate cellular interaction and proliferation. Here, we review the FDC signalling molecules that have recently been identified, some of which offer potential therapeutic targets for autoimmune diseases and B-cell lymphomas.
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Affiliation(s)
- Chan-Sik Park
- Laboratory of Cellular Immunology, 1516 Jefferson Highway, Ochsner Clinic Foundation, New Orleans, LA 70121, USA
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224
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Somerville RA, Hamilton S, Fernie K. Transmissible spongiform encephalopathy strain, PrP genotype and brain region all affect the degree of glycosylation of PrPSc. J Gen Virol 2005; 86:241-246. [PMID: 15604453 DOI: 10.1099/vir.0.80251-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Transmissible spongiform encephalopathies (TSEs), sometimes known as prion diseases, are caused by an infectious agent whose molecular properties have not been determined. Traditionally, different strains of TSE diseases are characterized by a series of phenotypic properties after passage in experimental animals. More recently it has been recognized that diversity in the degree to which an abnormal form of the host protein PrP, denoted PrPSc, is glycosylated and the migration of aglycosyl forms of PrPSc on immunoblots may have some differential diagnostic potential. It has been recognized that these factors are affected by the strain of TSE agent but also by other factors, e.g. location within the brain. This study shows in some cases, but not others, that host PrP genotype has a major influence on the degree of PrPSc glycosylation and migration on gels and provides further evidence of the effect of brain location. Accordingly both the degree of glycosylation and the apparent molecular mass of PrPSc may be of some value for differential diagnosis between TSE strains, but only when host effects are taken into account. Furthermore, the data inform the debate about how these differences arise, and favour hypotheses proposing that TSE agents affect glycosylation of PrP during its biosynthesis.
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Affiliation(s)
- Robert A Somerville
- Neuropathogenesis Unit, Institute for Animal Health, West Mains Road, Edinburgh EH9 3JF, UK
| | - Scott Hamilton
- Neuropathogenesis Unit, Institute for Animal Health, West Mains Road, Edinburgh EH9 3JF, UK
| | - Karen Fernie
- Neuropathogenesis Unit, Institute for Animal Health, West Mains Road, Edinburgh EH9 3JF, UK
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225
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Unterberger U, Voigtländer T, Budka H. Pathogenesis of prion diseases. Acta Neuropathol 2005; 109:32-48. [PMID: 15645262 DOI: 10.1007/s00401-004-0953-9] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2004] [Accepted: 10/18/2004] [Indexed: 11/28/2022]
Abstract
Prion diseases are rare neurological disorders that may be of genetic or infectious origin, but most frequently occur sporadically in humans. Their outcome is invariably fatal. As the responsible pathogen, prions have been implicated. Prions are considered to be infectious particles that represent mainly, if not solely, an abnormal, protease-resistant isoform of a cellular protein, the prion protein or PrP(C). As in other neurodegenerative diseases, aggregates of misfolded protein conformers are deposited in the CNS of affected individuals. Pathogenesis of prion diseases comprises mainly two equally important, albeit essentially distinct, topics: first, the mode, spread, and amplification of infectivity in acquired disease, designated as peripheral pathogenesis. In this field, significant advances have implicated an essential role of lymphoid tissues for peripheral prion replication, before a likely neural spread to the CNS. The second is the central pathogenesis, dealing, in addition to spread and replication of prions within the CNS, with the mechanisms of nerve cell damage and death. Although important roles for microglial neurotoxicity, oxidative stress, and complement activation have been identified, we are far from complete understanding, and therapeutic applications in prion diseases still need to be developed.
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226
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227
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Kim TY, Kim YS, Kim JK, Shon HJ, Lee YH, Kang CB, Park JS, Kang KS, Lee YS. Risk Analysis of Bovine Spongiform Encephalopathy in Korea. J Vet Med Sci 2005; 67:743-52. [PMID: 16141660 DOI: 10.1292/jvms.67.743] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The occurrence of Bovine Spongiform Encephalopathy (BSE, so called mad cow diseases) that was first identified in England in 1986 was considered as being limited to only European countries, including England. However, the outbreak in Asia as well as North America since 2001 has amplified the fear that there isn't any nation in the world that is a safe area. In order to assess the risk of BSE outbreak in each country, the Office International des Epizooties (OIE) and EU have respectively established criteria, where OIE has set 5 levels and EU has set 4 levels. The Scientific Steering Committee (SSC) of the European Commission conducted a Geographical BSE Risk(GBR) assessment for 64 nations, such as the United States, etc., as of April 29, 2003. However, as of July 1, 2005, the duty of GBR assessment is expected to be transferred to a newly established body called EFSA (European Food Safety Authority, located in Parma, Italy). As Korea has not undergone a GBR assessment up to now, this study analyzed the risk of BSE outbreak in Korea by reviewing BSE prevention measures, etc., that have been put in place. This study shall be a barometer for estimating the GBR assessment level of Korea.
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Affiliation(s)
- Tae-Yung Kim
- Animal Health Division Ministry of Agriculture & Forestry, Kwacheon, Korea
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228
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Veber B. [From a policy of maximal security to a policy of health care equality]. ANNALES FRANCAISES D'ANESTHESIE ET DE REANIMATION 2004; 23:1129-30. [PMID: 15589350 DOI: 10.1016/j.annfar.2004.10.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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229
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Foster PR, Griffin BD, Bienek C, McIntosh RV, MacGregor IR, Somerville RA, Steele PJ, Reichl HE. Distribution of a bovine spongiform encephalopathy-derived agent over ion-exchange chromatography used in the preparation of concentrates of fibrinogen and factor VIII. Vox Sang 2004; 86:92-9. [PMID: 15023177 DOI: 10.1111/j.0042-9007.2004.00403.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND AND OBJECTIVES The risk of haemophiliacs contracting variant Creutzfeldt-Jakob disease (vCJD) via treatment with factor VIII concentrates is not known. Therefore, in order to determine the extent to which the vCJD agent might be removed during the preparation of factor VIII concentrate, the partitioning of a bovine spongiform encephalopathy (BSE)-derived agent was measured over the main purification step used to prepare the Scottish National Blood Transfusion Service high-purity factor VIII concentrate (Liberate). MATERIALS AND METHODS Murine-passaged BSE (strain 301V), in the form of a microsomal fraction prepared from infected brain, was used to 'spike' a solution of factor VIII of intermediate purity. The 'spiked' starting material was subjected to solvent-detergent treatment and then to anion-exchange chromatography with Toyopearl DEAE-650M. All fractions were tested for 301V infectivity using a murine bioassay, including the procedures used to clean the ion-exchange media after use. RESULTS BSE 301V infectivity was reduced by 2.9 log(10) in the fibrinogen fraction and by 2.7 log(10) in the factor VIII fraction. Over 99% of the added 301V infectivity remained bound to the ion-exchange column after elution of factor VIII. A large quantity of infectivity was subsequently removed by washing the ion-exchange media with 2 m NaCl. No further BSE 301V infectivity was detected in column eluates after treatment with 0.1 m NaOH or a second wash with 2 m NaCl. CONCLUSIONS Results using a BSE-derived agent suggest that vCJD infectivity would be substantially removed by the ion-exchange process used in the preparation of fibrinogen and factor VIII concentrate. Although 301V infectivity remained bound to the ion-exchange matrix following elution of factor VIII, this appeared to be eliminated by the procedure used for cleaning the ion-exchange media after each use.
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Affiliation(s)
- P R Foster
- Scottish National Blood Transfusion Service, Edinburgh, UK.
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230
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Yakovleva O, Janiak A, McKenzie C, McShane L, Brown P, Cervenakova L. Effect of protease treatment on plasma infectivity in variant Creutzfeldt-Jakob disease mice. Transfusion 2004; 44:1700-5. [PMID: 15584983 DOI: 10.1111/j.0041-1132.2004.04198.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND The emergence of variant Creutzfeldt-Jakob disease (vCJD) and of a probable transmission of the disease through blood transfusion from a presymptomatic case has underlined the need for a reliable, sensitive, and specific screening test. This study was initiated to explain why attempts to identify protease-resistant prion protein (PrPres) following treatment with proteinase K (PK) in blood or blood components have so far failed. STUDY DESIGN AND METHODS RIII mice were inoculated intracerebrally (i.c.) with vCJD agent. As soon as some mice became ill, blood from all mice was collected, pooled, and separated into components. Aliquots of plasma were treated with either 100 and 500 microg per mL PK or left untreated. Samples were analyzed for total protein and for PrPres by Western blot with 6H4 antibodies. Infectivity in PK-treated and untreated samples was bioassayed by i.c. inoculation into healthy mice. RESULTS Estimated infectivity in untreated control plasma was 20.6 IU per mL. Treatment of plasma with 100 or 500 microg per mL PK resulted in estimated infectivity levels of 8.4 and 5.2 IU per mL, respectively. Coomassie staining revealed substantial changes in the protein profile after PK treatment, with massive degradation of proteins at 500 microg per mL PK. No PrPres was detected in plasma samples by Western blotting. CONCLUSION Infectivity in plasma of vCJD-infected mice showed a trend toward reduction following enzymatic treatment with increasing doses of PK, possibly because of activity against proteolysis-sensitive isoforms of abnormal prion protein. It is concluded that the use of PK in protocols for the detection of PrPres may decrease the sensitivity of blood-based assays.
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Affiliation(s)
- Oksana Yakovleva
- Jerome H. Holland Laboratory for the Biomedical Sciences, American Red Cross, Rockville, Maryland 20855, USA
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231
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Spraker TR, Balachandran A, Zhuang D, O'Rourke KI. Variable patterns of distribution of PrP(CWD) in the obex and cranial lymphoid tissues of Rocky Mountain elk (Cervus elaphus nelsoni) with subclinical chronic wasting disease. Vet Rec 2004; 155:295-302. [PMID: 15478500 DOI: 10.1136/vr.155.10.295] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Sections of medulla oblongata, taken at the level of the obex, palatine tonsil and medial retropharyngeal lymph node from 10,269 captive Rocky Mountain elk (Cervus elaphus nelsoni), were examined by immunohistochemical staining with monoclonal antibody for the prion protein associated with the transmissible spongiform encephalopathy of cervids, chronic wasting disease (PrP(CWD)). The protein was detected in 226 of them. On the basis of the anatomical location of the deposits in the brainstem of 183 elk, four distinct patterns of distribution of PrP(CWD) within the parasympathetic region of the dorsal motor nucleus of the vagus nerve and the adjacent nuclei were observed. Mild gross lesions of chronic wasting disease (serous atrophy of fat) were observed in only three elk, all with spongiform degeneration; the other elk were considered to be in the preclinical stage of the disease. In contrast with the relatively predictable distribution of prion protein (PrP) in the brain and cranial nodes of sheep and mule deer, the distribution of PrP(CWD) in the brain and nodes of the elk was more variable and unrelated to their PrP genotype. One hundred and fifty-five of the 226 positive elk had deposits of PrP(CWD) in the brainstem and lymphoid tissues, 43 had deposits only in the lymphoid tissue and 28 had deposits only in the brainstem.
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Affiliation(s)
- T R Spraker
- Colorado State University, Fort Collins, CO, USA
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232
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Marcos Z, Pffeifer K, Bodegas ME, Sesma MP, Guembe L. Cellular prion protein is expressed in a subset of neuroendocrine cells of the rat gastrointestinal tract. J Histochem Cytochem 2004; 52:1357-65. [PMID: 15385582 DOI: 10.1177/002215540405201012] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Prion diseases are believed to develop from the conformational change of normal cellular prion protein (PrPc) to a pathogenic isoform (PrPsc). PrPc is present in both the central nervous system and many peripheral tissues, although protein concentration is significantly lower in non-neuronal tissues. PrPc expression is essential for internalization and replication of the infectious agent. Several works have pointed to the gastrointestinal (GI) tract as the principal site of entry of PrPsc, but how passage through the GI mucosa occurs is not yet known. Here we studied PrPc expression using Western blot, RT-PCR, and immunohistochemistry in rat GI tract. PrPc mRNA and protein were detected in corpus, antrum, duodenum, and colon. Immunoreactivity was found in scattered cells of the GI epithelium. With double immunofluorescence, these cells have been identified as neuroendocrine cells. PrPc immunostaining was found in subsets of histamine, somatostatin (Som), ghrelin, gastrin (G), and serotonin (5HT) cells in stomach. In small and large bowel, PrPc cells co-localized with subpopulations of 5HT-, Som-, G-, and peptide YY-immunolabeled cells. Our results provide evidence for a possible and important role of endocrine cells in the internalization of PrPsc from gut lumen.
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Affiliation(s)
- Zuberoa Marcos
- Department of Histology and Pathology, University of Navarra, 31008 Pamplona, Spain
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233
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Abstract
Prion diseases are among the most intriguing infectious diseases and are associated with unconventional proteinaceous infectious agents known as prions. Prions seem to lack nucleic acid and propagate by transmission of protein misfolding. The nature of prions and their unique mode of transmission present challenges for early diagnosis of prion diseases. In this article, state-of-the-art prion diagnostic techniques, together with the new strategies that are being used to develop sensitive, early and non-invasive diagnoses for these diseases are reviewed.
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Affiliation(s)
- Claudio Soto
- Department of Neurology, University of Texas Medical Branch, 301 University Boulevard, Galveston, Texas 77555-0646, USA.
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234
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Ritchie DL, Head MW, Ironside JW. Advances in the detection of prion protein in peripheral tissues of variant Creutzfeldt-Jakob disease patients using paraffin-embedded tissue blotting. Neuropathol Appl Neurobiol 2004; 30:360-8. [PMID: 15305981 DOI: 10.1111/j.1365-2990.2003.00544.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The accumulation of PrP(Sc), an abnormal and disease-associated form of the normal prion protein (PrP(c)), within the central nervous system (CNS) is a key pathological feature of Creutzfeldt-Jakob disease (CJD). Following limited proteolytic digestion of PrP(Sc), the detection of PrP(res) within lymphoid tissues is a unique characteristic of variant CJD in comparison with other human prion diseases, raising fears of an increased risk of iatrogenic spread. Because levels of PrP(res) in lymphoid tissues are lower than those found in CNS tissue, there is concern that other peripheral tissues may harbour infectivity at levels that current detection systems cannot demonstrate PrP(res). We have modified the paraffin-embedded tissue blot (PET blot), a technique combining immunohistochemistry (IHC), histoblot and Western blotting, for the detection of PrP(res) in paraffin sections in peripheral tissues in variant CJD. Five cases of variant CJD were examined, using a panel of anti-PrP antibodies. In each of these five cases, spleen, tonsil, lymph nodes and dorsal root ganglia showed an increase in the sensitivity and specificity of labelling using the PET blot when compared with optimized PrP(res) IHC methods. Control cases showed no evidence of PrP accumulation in either peripheral or CNS tissues. Autopsy and biopsy brain material from sporadic CJD cases also showed an increased sensitivity of PrP(res) detection with the PET blot, confirming its value as an important diagnostic and research tool in human prion diseases.
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Affiliation(s)
- D L Ritchie
- National Creutzfeldt-Jakob Disease Surveillance Unit, School of Clinical and Molecular Medicine, University of Edinburgh, Western General Hospital, Edinburgh, UK.
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235
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Frosh A, Smith LC, Jackson CJ, Linehan JM, Brandner S, Wadsworth JDF, Collinge J. Analysis of 2000 consecutive UK tonsillectomy specimens for disease-related prion protein. Lancet 2004; 364:1260-2. [PMID: 15464187 DOI: 10.1016/s0140-6736(04)17143-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Variant Creutzfeldt-Jakob disease (CJD) is thought to be caused by dietary or other exposure to bovine spongiform encephalopathy (BSE) prions. The prevalence of preclinical or subclinical prion infection in the UK is currently unknown. Since clinical variant CJD is uniformly associated with tonsillar prion infection, we screened 2000 anonymous surgical tonsillectomy specimens for disease-associated prion protein. Analysis by both high sensitivity immunoblotting and immunohistochemistry detected no positive cases. However, this negative result cannot provide reassurance that relevant community infection is unlikely because of the fairly small sample size, demographic and age-related factors, and unknown test sensitivity during the prolonged incubation period. Nevertheless, our findings establish a protocol for prevalence screening on a national scale.
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Affiliation(s)
- Adam Frosh
- MRC Prion Unit and Department of Neurodegenerative Disease, Institute of Neurology, University College, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
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236
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Abstract
The complement system is an essential component of the innate immune system that aids the recognition and destruction of pathogens. Despite the potent cytolytic activity of this system, some pathogens have turned interactions with complement to their advantage. Transmissible spongiform encephalopathies (TSEs), or prion diseases, also seem to use the complement system to facilitate target cell infection in lymphoid tissues. TSEs are associated with the accumulation of disease-specific prion protein in the brain, which is accompanied by progressive neurodegeneration. Unregulated activation of complement can cause host tissue damage, as observed in some neurodegenerative disorders, and active complement components have been detected in the brains of hosts with TSEs. Whether complement inhibitors will be useful to treat TSEs remains to be determined.
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Affiliation(s)
- Neil A Mabbott
- Institute for Animal Health, Neuropathogenesis Unit, Ogston Building, West Mains Road, Edinburgh EH9 3JF, UK.
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237
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Ironside JW, Head MW. Variant Creutzfeldt-Jakob disease: risk of transmission by blood and blood products. Haemophilia 2004; 10 Suppl 4:64-9. [PMID: 15479374 DOI: 10.1111/j.1365-2516.2004.00982.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Variant Creutzfeldt-Jakob disease (CJD) is a novel acquired human prion disease apparently resulting from exposure to the bovine spongiform encephalopathy (BSE) agent. Variant CJD differs from other human prion diseases in that the disease-associated form of the prion protein and infectivity are readily detectable in lymphoid tissues throughout the body. Lymphoid tissues and lymphocytes are implicated in the peripheral pathogenesis of prion diseases (where infectivity may be detected during the preclinical phase of the illness), giving rise to concerns that blood and blood products may also contain infectious particles, representing a possible source of iatrogenic spread of variant CJD. This concern has been reinforced following the experimental transmission of BSE in a sheep model by transfusion of blood and buffy coat from animals in the preclinical phase of the illness, and the recent identification of a UK case of variant CJD in a patient who had received packed red blood cells that had been donated by an individual who subsequently died from variant CJD. Studies in animal models suggest that most prion infectivity in blood may be cell-associated, with lower levels in the plasma, and there is evidence to suggest that any infectivity present may be reduced during the process of plasma fractionation. However, the possibility that plasma or blood products could transmit the disease cannot be excluded. Further studies are required to develop more sensitive means to detect disease-associated prion protein in blood; such techniques could be employed for screening purposes to reduce exposure to contaminated products and to assist with risk management in potentially exposed individuals.
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Affiliation(s)
- J W Ironside
- National Creutzfeldt-Jakob Disease Surveillance Unit, Edinburgh, UK.
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238
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Tropitzsch A, Zenner HP. [Decontamination and sterilization of surgical instruments in suspected Creutzfeldt-Jakob disease. Are we converting to the recommendations by the Robert Koch Institute?]. HNO 2004; 52:871-4. [PMID: 15309323 DOI: 10.1007/s00106-004-1151-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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239
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Healy CM, Kearns HPO, Coulter WA, Stevenson M, Burke FJT. Autoclave use in dental practice in the Republic of Ireland. Int Dent J 2004; 54:182-6. [PMID: 15335087 DOI: 10.1111/j.1875-595x.2004.tb00278.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
AIMS To assess by postal questionnaire, cross-infection control methods, especially sterilisation procedures, of 700 general dental practitioners in the Republic of Ireland, and to biologically monitor steam pressure sterilisers or autoclaves in their practices. MAIN OUTCOME MEASURES Methods of instrument cleaning and sterilisation, autoclave efficacy. RESULTS A response rate of 40% with all, except one practitioner, using steam sterilisation. 49% also reported the use of chemical sterilisation with a quarter of these using glutaraldehyde. However, instrument soaking time varied greatly from 2.5 minutes to 74 hours. Methods of instrument cleaning prior to autoclaving were as follows: scrubbing by hand 41.5%, ultrasonic cleaning 7.0%, combination of both 50%. 52.9% of the respondents did not autoclave their dental handpieces and only 44.7% disinfected impressions before sending them to the laboratory. The autoclaves of thirty practitioners (11.3%) did not pass the initial biological test. Following counselling about possible causes of failure, four autoclaves (1.5%) failed a repeat biological test. However, seven practitioners did not return the repeat biological test. CONCLUSIONS Some aspects of recommended cross-infection control procedures are well adhered to, e.g. instrument cleaning, but further education is required in certain key areas, in particular the use of chemical sterilisation, dental handpiece autoclaving and impression disinfection. There is also a need to increase awareness of the importance of routine autoclave servicing and calibration, along with validation and monitoring.
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Affiliation(s)
- C M Healy
- Department of Oral Surgery, Oral Medicine and Oral Pathology, Dublin Dental School and Hospital, Lincoln Place, Dublin 2, Ireland.
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240
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Mohan J, Brown KL, Farquhar CF, Bruce ME, Mabbott NA. Scrapie transmission following exposure through the skin is dependent on follicular dendritic cells in lymphoid tissues. J Dermatol Sci 2004; 35:101-11. [PMID: 15265522 DOI: 10.1016/j.jdermsci.2004.05.005] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2004] [Revised: 04/22/2004] [Accepted: 05/12/2004] [Indexed: 11/21/2022]
Abstract
BACKGROUND Transmissible spongiform encephalopathies (TSEs) are chronic infectious neurodegenerative diseases that are characterized by the accumulation in affected tissues of PrP(Sc), an abnormal isoform of the host prion protein (PrP(c)). Following peripheral exposure, PrP(Sc) usually accumulates on follicular dendritic cells (FDCS) in lymphoid tissues before neuroinvasion. Studies in mice have shown that TSE exposure through scarified skin is an effective means of transmission. Following inoculation via the skin, a functional immune system is critical for the transmission of scrapie to the brain as severe combined immunodeficiency (SCID) mice are refractory to infection. Until now, it was not known which components of the immune system are required for efficient scrapie neuroinvasion following skin scarification. OBJECTIVE To determine which cells are critical for the transmission of scrapie to the brain following inoculation via the skin. METHODS A chimeric mouse model was used, which had a mismatch in PrP(c) expression between FDCs and other bone marrow-derived cells within lymphoid tissues. These chimeric mice were challenged with scrapie by skin scarification to allow the separate roles of FDCs and lymphocytes in peripheral scrapie pathogenesis to be determined. RESULTS We show that mature FDCs are essential for the accumulation of scrapie within lymphoid tissues and the subsequent transmission of infection to the brain following TSE exposure by this route. Furthermore, we show that the accumulation of PrP(Sc) and infectivity in the spleen is independent of PrP expression by lymphocytes or other bone marrow-derived cells. CONCLUSION Following inoculation with scrapie by skin scarification, replication in the spleen and subsequent neuroinvasion is critically dependent upon mature FDCs.
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Affiliation(s)
- Joanne Mohan
- Institute for Animal Health, Ogston Building, West Mains Road, Edinburgh EH9 3JF, UK
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241
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Germain JL, Rezzoug A, Cargeac A, Morazin F, Montravers P. [Disposable material for tracheal intubation: pilot study using Penlon Crystal blades and Penlon Lary Gard sheaths]. ANNALES FRANCAISES D'ANESTHESIE ET DE REANIMATION 2004; 23:799-803. [PMID: 15345251 DOI: 10.1016/j.annfar.2004.05.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2003] [Accepted: 05/17/2004] [Indexed: 04/30/2023]
Abstract
OBJECTIVE The risk of cross infection due to non-conventional infectious agents has led to the development of single-use disposable medical material. For laryngoscopy, two attitudes have been proposed: the use of disposable blades or disposable translucide cover sheaths with steel blades. Practice studies assessing the quality of these devices are scarce, leaving the physician to his own experience. STUDY DESIGN Open pilot study assessing satisfaction of the users during tracheal intubation. PATIENTS AND METHODS Hundred patients of general surgery requiring tracheal intubation underwent laryngoscopy in routine condition with disposable blades (Penlon Crystal) or disposable cover sheaths (Penlon Lary Gard) with steel blades. The users gave a general appreciation of the device and specific comments on the easiness of insertion of the blade, intensity of light and its focus, quality of glottic exposure, easiness of tracheal tube insertion, and solidity of the device. RESULTS With both devices, intubation was impossible in 6% of the patients. The users considered that intubation was performed in comfortable conditions with both devices. Dim light was noticed with Crystal blade. CONCLUSION In case of use of disposable material, both devices seem to be close in terms of quality of intubation.
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Affiliation(s)
- J L Germain
- Département d'anesthésie-réanimation, CHU Jean-Verdier, AP-HP, avenue du 14-Juillet, 93143 Bondy cedex, France
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242
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Smith AJ, Russell DI, Greene J, Lowman A, Ironside JW. Presentation of a case of variant CJD in general dental practice. Br Dent J 2004; 197:75-6. [PMID: 15272338 DOI: 10.1038/sj.bdj.4811468] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2003] [Accepted: 01/16/2004] [Indexed: 11/08/2022]
Abstract
This case report describes the initial presentation of variant CJD to a general dental practitioner. The case highlights the importance of prompt referral of patients presenting with a history of atypical facial symptoms.
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Affiliation(s)
- A J Smith
- Infection Research Group, Glasgow Dental Hospital & School, Scotland.
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243
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Mulcahy ER, Bartz JC, Kincaid AE, Bessen RA. Prion infection of skeletal muscle cells and papillae in the tongue. J Virol 2004; 78:6792-8. [PMID: 15194754 PMCID: PMC421640 DOI: 10.1128/jvi.78.13.6792-6798.2004] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The presence of the prion agent in skeletal muscle is thought to be due to the infection of nerve fibers located within the muscle. We report here that the pathological isoform of the prion protein, PrP(Sc), accumulates within skeletal muscle cells, in addition to axons, in the tongue of hamsters following intralingual and intracerebral inoculation of the HY strain of the transmissible mink encephalopathy agent. Localization of PrP(Sc) to the neuromuscular junction suggests that this synapse is a site for prion agent spread between motor axon terminals and muscle cells. Following intracerebral inoculation, the majority of PrP(Sc) in the tongue was found in the lamina propria, where it was associated with sensory nerve fibers in the core of the lingual papillae. PrP(Sc) staining was also identified in the stratified squamous epithelium of the lingual mucosa. These findings indicate that prion infection of skeletal muscle cells and the epithelial layer in the tongue can be established following the spread of the prion agent from nerve terminals and/or axons that innervate the tongue. Our data suggest that ingestion of meat products containing prion-infected tongue could result in human exposure to the prion agent, while sloughing of prion-infected epithelial cells at the mucosal surface of the tongue could be a mechanism for prion agent shedding and subsequent prion transmission in animals.
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Affiliation(s)
- Ellyn R Mulcahy
- Department of Medical Microbiology and Immunology, Creighton University, Omaha, NE, USA
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244
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Hosszu LLP, Jackson GS, Trevitt CR, Jones S, Batchelor M, Bhelt D, Prodromidou K, Clarke AR, Waltho JP, Collinge J. The residue 129 polymorphism in human prion protein does not confer susceptibility to Creutzfeldt-Jakob disease by altering the structure or global stability of PrPC. J Biol Chem 2004; 279:28515-21. [PMID: 15123682 DOI: 10.1074/jbc.m313762200] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
There are two common forms of prion protein (PrP) in humans, with either methionine or valine at position 129. This polymorphism is a powerful determinant of the genetic susceptibility of humans toward both sporadic and acquired forms of prion disease and restricts propagation of particular prion strains. Despite its key role, we have no information on the effect of this mutation on the structure, stability, folding, and dynamics of the cellular form of PrP (PrP(C)). Here, we show that the mutation has no measurable effect on the folding, dynamics, and stability of PrP(C). Our data indicate that the 129M/V polymorphism does not affect prion propagation through its effect on PrP(C); rather, its influence is likely to be downstream in the disease mechanism. We infer that the M/V effect is mediated through the conformation or stability of disease-related PrP (PrP(Sc)) or intermediates or on the kinetics of their formation.
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Affiliation(s)
- Laszlo L P Hosszu
- Medical Research Council Prion Unit, Department of Neurodegenerative Disease, Institute of Neurology, University College London, Queen Square, London WC1N 3BG, United Kingdom
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245
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Janka J, Maldarelli F. Prion diseases: Update on mad cow disease, variant creutzfeldt-jakob disease, and the transmissible spongiform encephalopathies. Curr Infect Dis Rep 2004; 6:305-315. [PMID: 15265460 DOI: 10.1007/s11908-004-0053-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Transmissible spongiform encephalopathies (TSEs) are a group of progressive, fatal neurodegenerative disorders that share a common spongiform histopathology. TSEs may be transmitted in a sporadic, familial, iatrogenic, or zoonotic fashion. The putative infectious agent of TSE, the prion, represents a novel paradigm of infectious disease with disease transmission in the absence of nucleic acid. Several small but spectacular epidemics of TSEs in man have prompted widespread public health and food safety concerns. Although TSEs affect a comparatively small number of individuals, prion research has revealed fascinating insights of direct relevance to common illnesses. This paper reviews recent advances that have shed new light on the nature of prions and TSEs.
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Affiliation(s)
- Jacqueline Janka
- NCI, National Institutes of Health, Building 10, Room 12S245, Bethesda, MD 20892, USA.
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246
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Abstract
Bovine Spongiform Encephalopathy was discovered in 1986 in the United Kingdom and relatively rapidly spread into its trading partners in Europe via contaminated cattle feed supplements. The practice of using the discarded bovine carcass as cattle feed supplements led to the recycling of the prion agent and the consequent generation of new point source epidemics in the recipient countries. The advent of rapid diagnostic tests and more widespread testing has led to the identification of BSE in countries not previously reporting cases and the recognition of larger numbers of infections in countries previously only reporting clinical cases. The recognition of the wider spread of BSE and the 1996 recognition of vCJD as a human disease caused by consumption of BSE agent led to international concerns regarding the threat to human health and the demand for stricter controls on human food derived from cattle. Major shifts in food safety policy have occurred as a direct result. The recommendation that risk assessments for BSE infectivity and human exposure pathways be conducted rather than reliance upon rates and simple enumeration of BSE cases is one of the most prominent changes in the basis of policy regarding human health. The movement of BSE into human populations has a wider impact than seen in food safety--surgical procedures, blood, cells, tissues and organ donation programs are all affected. The World Health Organization has recommended that 'the eradication of BSE must remain the principle public health objective of national and international animal health control authorities'. The opinions expressed in this chapter are those of the author and do not necessarily reflect the views of Health Canada. This review was written while the author was employed at the WHO.
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Affiliation(s)
- M N Ricketts
- Health Canada, Tunney's Pasture 0601E2, Building 6, Ottawa, Ontario K1A 0L2, Canada.
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Schreiber GB, Sanchez AM, Garratty G, Nass CC, Tu Y, Busch MP. Mammalian brain consumption by blood donors in the United States: brains today, deferred tomorrow? Transfusion 2004; 44:667-74. [PMID: 15104646 DOI: 10.1111/j.1537-2995.2004.03114.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Theoretical concerns of possible variant CJD (vCJD) transmission by transfusion have led to deferral of US donors potentially exposed to the bovine spongiform encephalopathy agent. Although the efficacy of these policies is unknown, impact on blood collections has been substantial. Under the precautionary principle, deferral of donors consuming bovine (or other mam-malian) brains, possibly contaminated with the vCJD agent, might be considered. Blood donors were surveyed to determine lifetime mammalian brain consumption. STUDY DESIGN AND METHODS The Retrovirus Epidemiology Donor Study (REDS) conducted an anonymous mail survey of 92,581 donors from eight US blood centers. RESULTS Responses were received from 52,650 donors (57%). Of these, 6.4 percent reported lifetime brain consumption; bovine (3.6%) and hog brains (1.7%) were the most common. Bovine brain consumption varied fourfold by center (1.7-7.0%) and was highest among male (4.5%), older (age 55+, 6.5%), foreign-born (9.2%), Asian (7.2%), and Hispanic (8.6%) donors. Among bovine brain consumers, 67 percent engaged in the practice 4 times or less, 79 percent were repeat donors, and 61 percent reported giving at least 11 donations in the past 10 years. CONCLUSION Following the precautionary principle, further steps to reduce the theoretical vCJD risk could include deferring donors who eat bovine (or other mammalian) brains. The impact of such a policy would not be trivial, especially in areas with older, foreign-born, Asian, or Hispanic donors. Cautious implementation and periodic evaluation of deferral policies is warranted.
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Abstract
Young onset dementia is a challenging clinical problem with potentially devastating medical and social consequences. The differential diagnosis is wide, and includes a number of rare sporadic and hereditary diseases. However, accurate diagnosis is often possible, and all patients should be thoroughly investigated to identify treatable processes. This review presents an approach to the diagnosis, investigation, and management of patients with young onset dementia, with particular reference to common and treatable causes.
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Affiliation(s)
- E L Sampson
- Dementia Research Group, Institute of Neurology, University College London, London, UK
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Hilton DA, Sutak J, Smith MEF, Penney M, Conyers L, Edwards P, McCardle L, Ritchie D, Head MW, Wiley CA, Ironside JW. Specificity of lymphoreticular accumulation of prion protein for variant Creutzfeldt-Jakob disease. J Clin Pathol 2004; 57:300-2. [PMID: 14990604 PMCID: PMC1770247 DOI: 10.1136/jcp.2003.012278] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND Immunocytochemical accumulation of prion protein (PrP) in lymphoid tissues is a feature of variant Creutzfeldt-Jakob disease (vCJD) that has been used both to aid in the diagnosis of patients and as a basis of large scale screening studies to assess the prevalence of preclinical disease in the UK. However, the specificity of this approach is unknown. AIM To assess the specificity of lymphoreticular accumulation of PrP for vCJD by examining a range of human diseases. METHODS Paraffin wax embedded lymphoreticular tissues from patients with several reactive conditions (58 cases), tumours (27 cases), vCJD (54 cases), and other human prion diseases (56 cases) were assessed. PrP accumulation was assessed by immunocytochemistry using two different monoclonal anti-PrP antibodies and a sensitive detection system. RESULTS All cases of vCJD showed widespread lymphoreticular accumulation of PrP; however, this was not seen in the other conditions examined. CONCLUSION Lymphoreticular accumulation of PrP, as assessed by immunocytochemistry, appears to be a highly specific feature of vCJD.
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Affiliation(s)
- D A Hilton
- Department of Histopathology, Derriford Hospital, Plymouth PL6 8DH, UK
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250
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