Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| design and validation of a high-throughput assay to detect codon 146 polymorphisms in the caprine prion protein gene. | in sheep, scrapie susceptibility is so strongly associated with single nucleotide polymorphisms (snps) in the gene encoding the prion protein (prp) that this linkage constitutes the basis for selective breeding strategies directed toward controlling the disease. for goats, in contrast, the association between scrapie susceptibility/resistance and variations in the prp gene is far weaker, with only a few identified snps showing an influence on scrapie susceptibility. a recent survey of prp genoty ... | 2009 | 19559665 |
| role of adams in the ectodomain shedding and conformational conversion of the prion protein. | the cellular prion protein (prp(c)) is essential for the pathogenesis and transmission of prion diseases. prp(c) is bound to the plasma membrane via a glycosylphosphatidylinositol anchor, although a secreted, soluble form has also been identified. previously we reported that prp(c) is subject to ectodomain shedding from the membrane by zinc metalloproteinases with a similar inhibition profile to those involved in shedding the amyloid precursor protein. here we have used gain-of-function (overexp ... | 2009 | 19564338 |
| nor98 scrapie identified in the united states. | a distinct strain of scrapie identified in sheep of norway in 1998 has since been identified in numerous countries throughout europe. the disease is known as nor98 or nor98-like scrapie, among other names. distinctions between classic scrapie and nor98 scrapie are made based on histopathology and immunodiagnostic results. there are also differences in the epidemiology, typical signalment, and likelihood of clinical signs being observed. in addition, sheep that have genotypes associated with resi ... | 2009 | 19564493 |
| human variant creutzfeldt-jakob disease and sheep scrapie prp(res) detection using seeded conversion of recombinant prion protein. | the pathological isoform of the prion protein (prp(res)) can serve as a marker for prion diseases, but more practical tests are needed for preclinical diagnosis and sensitive detection of many prion infections. previously we showed that the quaking-induced conversion (quic) assay can detect sub-femtogram levels of prp(res) in scrapie-infected hamster brain tissue and distinguish cerebral spinal fluid (csf) samples from normal and scrapie-infected hamsters. we now report the adaptation of the qui ... | 2009 | 19570812 |
| journal club. a systems biologist ponders how disparate ideas can sometimes come together beautifully. | 2009 | 19661875 | |
| altered electroretinogram b-wave in a suffolk sheep experimentally infected with scrapie. | 2009 | 19666917 | |
| evaluating different prp genotype selection strategies for expected severity of scrapie outbreaks and genetic progress in performance in commercial sheep. | stochastic computer simulations were used for quantifying the effect of selecting on prion protein (prp) genotype on the risk of major outbreaks of classical scrapie and the rate of genetic progress in performance in commercial sheep populations already undergoing selection on performance. the risk of a major outbreak on a flock was measured by the basic reproduction ratio (r(0)). the effectiveness of different prp selection strategies for reducing the population risk was assessed by the percent ... | 2009 | 19577317 |
| sequence analysis of the prion protein gene in mongolian gazelles (procapra gutturosa). | prion diseases are a group of human and animal neurodegenerative conditions, which are caused by the deposition of an abnormal isoform prion protein (prpsc) encoded by a single copy prion protein gene (prnp). in sheep, genetic variations of prnp were found to be associated with the incubation period, susceptibility, and species barrier to the scrapie disease. we investigated the sequence and polymorphisms of the prion protein gene of mongolian gazelles (gprnp). gprnp gene sequence analysis of bl ... | 2009 | 19579063 |
| phosphorylation of prion protein at serine 43 induces prion protein conformational change. | the cause of the conformational change of normal cellular prion protein (prp) into its disease-associated form is unknown. posttranslational modifications, such as glycosylation, acetylation, s-nitrosylation, and phosphorylation, are known to induce protein conformational changes. here, we investigated whether phosphorylation could induce the conformational change of prp because prp contains several kinase motifs and has been found recently in the cytosol, in which kinases generally reside. neur ... | 2009 | 19587281 |
| prion protein detection via direct immuno-quantitative real-time pcr. | we describe a simple and robust assay for the quantitative detection of prions using immuno-quantitative real-time pcr (iq-rt-pcr) made possible by a direct conjugate of a prion-specific antibody (icsm35) and a synthetic 99-bp dna tail. the dna tail was engineered to include a single scrfi restriction site, which enabled subsequent quantification of restricted dna tails using real-time pcr. the assay was tested with scrapie prions bound to polyvinylidene difluoride membranes and to 96-well plate ... | 2009 | 19596031 |
| distinct structures of scrapie prion protein (prpsc)-seeded versus spontaneous recombinant prion protein fibrils revealed by hydrogen/deuterium exchange. | the detailed structures of prion disease-associated, partially protease-resistant forms of prion protein (e.g. prp(sc)) are largely unknown. prp(sc) appears to propagate itself by autocatalyzing the conformational conversion and oligomerization of normal prion protein (prp(c)). one manifestation of prp(sc) templating activity is its ability, in protein misfolding cyclic amplification reactions, to seed the conversion of recombinant prion protein (rprp) into aggregates that more closely resemble ... | 2009 | 19596861 |
| quantifying diversity losses due to selection for scrapie resistance in three endangered spanish sheep breeds using microsatellite information. | the effect of selection for scrapie resistance on genetic variability in three endangered spanish sheep breeds (colmenareña, mallorquina and rubia de el molar) was studied using two different criteria for quantifying contributions to genetic variability: (a) molecular coancestry or genetic identity; and (b) average number of alleles per locus or allelic richness. a total of 236 (81 colmenareña, 76 mallorquina and 79 rubia de el molar) individuals were genotyped for the prp gene and for 22 micros ... | 2009 | 19625092 |
| differential display detects host nucleic acid motifs altered in scrapie-infected brain. | the transmissible spongiform encephalopathies (tses) including scrapie have been attributed to an infectious protein or prion. infectivity is allied to conversion of the endogenous nucleic-acid-binding protein prp to an infectious modified form known as prp(sc). the protein-only theory does not easily explain the enigmatic properties of the agent including strain variation. it was previously suggested that a short nucleic acid, perhaps host-encoded, might contribute to the pathoetiology of the t ... | 2009 | 19631225 |
| antiprion action of new cyclodextrin analogues. | prion disorders are characterised by the accumulation of a misfolded isoform (prpsc) of the host encoded prion protein (prpc). this paper examines the antiprion potential of cyclodextrin (cd) analogues and it identifies sulphated-beta-cyclodextrin, with a half-maximal inhibitory concentration (ic50) of 2.4 microm, as having 31-fold greater antiprion activity than that previously reported for beta-cyclodextrin (betacd). | 2009 | 19631725 |
| detection of prpsc in blood from sheep infected with the scrapie and bovine spongiform encephalopathy agents. | the role of blood in the iatrogenic transmission of transmissible spongiform encephalopathy (tse) or prion disease has become an increasing concern since the reports of variant creutzfeldt-jakob disease (vcjd) transmission through blood transfusion from humans with subclinical infection. the development of highly sensitive rapid assays to screen for prion infection in blood is of high priority in order to facilitate the prevention of transmission via blood and blood products. in the present stud ... | 2009 | 19740979 |
| influence of adam10 on prion protein processing and scrapie infectiosity in vivo. | both the cellular prion protein (prp(c)) and the amyloid precursor protein (app) are physiologically subjected to complex proteolytic processing events. while for app the proteinases involved--alpha-, beta- and gamma-secretase--have been identified in vitro and in vivo, the cleavage of prp(c) by now has been linked only to the shedding activity of the metalloproteinase adam10 and/or adam17 in cell culture. here we show that neuronal overexpression of the alpha-secretase adam10 in mice reduces al ... | 2009 | 19632330 |
| transgenic mice expressing porcine prion protein resistant to classical scrapie but susceptible to sheep bovine spongiform encephalopathy and atypical scrapie. | how susceptible pigs are to infection with sheep prions is unknown. we show, through transmission experiments in transgenic mice expressing porcine prion protein (prp), that the susceptibility of this mouse model to bovine spongiform encephalopathy (bse) can be enhanced after its passage in arq sheep, indicating that the pathogenicity of the bse agent is modified after passage in sheep. transgenic mice expressing porcine prp were, nevertheless, completely resistant to infection with a broad pane ... | 2009 | 19751582 |
| the kuru infectious agent is a unique geographic isolate distinct from creutzfeldt-jakob disease and scrapie agents. | human sporadic creutzfeldt-jakob disease (scjd), endemic sheep scrapie, and epidemic bovine spongiform encephalopathy (bse) are caused by a related group of infectious agents. the new u.k. bse agent spread to many species, including humans, and clarifying the origin, specificity, virulence, and diversity of these agents is critical, particularly because infected humans do not develop disease for many years. as with viruses, transmissible spongiform encephalopathy (tse) agents can adapt to new sp ... | 2009 | 19633190 |
| [alternations of tau protein and its phosphorylated profiles in the experimental hamsters infected by scrapie agents 263k and 139a]. | in human prion diseases, phosphorylated-tau deposition has been described in a rare genetic form, gerstmann-straussler-scheinker disease, but is not considered part of the neuropathological picture of creutzfeldt-jakob disease. to investigate the possible changes of tau and phosphorylated tau (ser396/ser404) in transmissible spongiform encephalopathies (tses), the expressions and transcriptions of above biological factors in the brain tissues of 263k- and 139a-infected hamsters were evaluated by ... | 2009 | 19634763 |
| role of copper and manganese in prion disease progression. | the cellular prion protein (prp(c)), a copper binding protein has a primary role in the pathogenesis of in prion diseases. in these diseases alterations in the levels of copper and manganese have been described but how these alterations are involved in the pathogenesis is still unknown. here we analysed synaptosomes of scrapie infected mice and observed a significant reduction in the amount of copper and an increase of the manganese content at day 100 after infection. moreover a reduction of the ... | 2009 | 19635464 |
| evaluation of the possible transmission of bse and scrapie to gilthead sea bream (sparus aurata). | in transmissible spongiform encephalopathies (tses), a group of fatal neurodegenerative disorders affecting many species, the key event in disease pathogenesis is the accumulation of an abnormal conformational isoform (prp(sc)) of the host-encoded cellular prion protein (prp(c)). while the precise mechanism of the prp(c) to prp(sc) conversion is not understood, it is clear that host prp(c) expression is a prerequisite for effective infectious prion propagation. although there have been many stud ... | 2009 | 19636413 |
| proteomic profiling of prp27-30-enriched preparations extracted from the brain of hamsters with experimental scrapie. | transmissible spongiform encephalopathies (tses) are neurodegenerative disorders characterized by the accumulation in the cns of a pathological conformer (prp(tse)) of the host-encoded cellular prion protein (prp(c)). prp(tse) has a central role in the pathogenesis of the disease but other factors are likely involved in the pathological process. in this work we employed a multi-step proteomic approach for the identification of proteins that co-purify with the protease-resistant core of prp(tse) ... | 2009 | 19637240 |
| the role of the prion protein membrane anchor in prion infection. | normal cellular and abnormal disease-associated forms of prion protein (prp) contain a c-terminal glycophosphatidyl-inositol (gpi) membrane anchor. the importance of the gpi membrane anchor in prion diseases is unclear but there are data to suggest that it both is and is not required for abnormal prion protein formation and prion infection. utilizing an in vitro model of prion infection we have recently demonstrated that, while the gpi anchor is not essential for the formation of abnormal prion ... | 2009 | 19786843 |
| the unfolding of the prion protein sheds light on the mechanisms of prion susceptibility and species barrier. | prion diseases are a group of fatal neurodegenerative disorders that manifest as infectious, sporadic, or familial and are all associated with the misfolding of the prion protein (prp). disease-modulating polymorphisms in the prp amino acid sequence can make an individual more or less susceptible to infection. one example is the presence of arginine in place of glutamine at position 171 in sheep, which confers resistance to scrapie. to investigate whether the physical folding properties of prp a ... | 2009 | 19655812 |
| frequent missense and insertion/deletion polymorphisms in the ovine shadoo gene parallel species-specific variation in prp. | the cellular prion protein prp(c) is encoded by the prnp gene. this protein is expressed in the central nervous system (cns) and serves as a precursor to the misfolded prp(sc) isoform in prion diseases. the prototype prion disease is scrapie in sheep, and whereas prnp exhibits common missense polymorphisms for v136a, r154h and q171r in ovine populations, genetic variation in mouse prnp is limited. recently the cns glycoprotein shadoo (sho) has been shown to resemble prp(c) both in a central hydr ... | 2009 | 19657386 |
| [analysis of monoclonal antibody binding sites in ovine prion protein]. | binding sites of five monoclonal antibodies were obtained by reinforceable method of overlapping recombinant prion protein and synthetic peptide. overlapping peptides of prp core were expressed in escherichia coli by insertion of serial pcr amplicons of ovine prp gene fragments into pet32a. the expressed fusion peptides were then tested for the binding activity to prp monoclonal antibodies in western blotting. the binding sites of 5 monoclonal antibodies of ovine prp were located respectively as ... | 2009 | 19621573 |
| establishment of bovine prion peptide-based monoclonal antibodies for identifying bovine prion. | to obtain high titer monoclonal antibodies (mcabs) which can react with mammalian prion protein (prp), balb/c mice were immunized with bovine (bo) prp peptide (boprp 209-228 aa) coupled to keyhole limpet hemocyanin (klh). the hybridoma cell lines secreting monoclonal antibodies against the peptide were established by cell fusion and cloning. the obtained mcabs were applied to detect recombinant human, bovine and hamster prp, cellular prion protein (prp(c)) in normal bovine brain and pathogenic s ... | 2009 | 19727594 |
| prion metal interaction: is prion pathogenesis a cause or a consequence of metal imbalance? | functional role of cellular prion protein (prpc) has been hypothesized to be in metal homeostasis and providing cells with a superoxide dismutase (sod)-like activity to escape damage by reactive oxygen species (ros). prpc interacts with a range of divalent metal ions and undergoes cu2+ as well as zn2+-associated endocytosis, thereby maintaining homeostasis of these and other metal ions. conformational change to a beta-sheet rich, protease resistant entity, reminiscent of the disease-associated s ... | 2009 | 19660443 |
| the evaluation of exposure risks for natural transmission of scrapie within an infected flock. | although the epidemiology of scrapie has been broadly understood for many years, attempts to introduce voluntary or compulsory controls to eradicate the disease have frequently failed. lack of precision in defining the risk factors on farm has been one of the challenges to designing control strategies. this study attempted to define which parts of the annual flock management cycle represented the greatest risk of infection to naive lambs exposed to the farm environment at different times. | 2009 | 19818127 |
| st1859 reduces prion infectivity and increase survival in experimental scrapie. | on the basis of the structural homologies between st1859 (1[(2-hydroxy-1-naphtyl)methyl]-2-naphthol) and the anti-prion agents and its anti-amyloidogenic activity, we tested whether this molecule altered the biochemical properties of aggregates formed in vitro by synthetic prion peptides and affected prion infectivity in experimental scrapie. co-incubation of st1859 with the peptides prp 106-126 and prp 82-146 reduced their fibrillogenic capacity and their resistance to digestion with protease k ... | 2009 | 19685199 |
| high prevalence of scrapie in a dairy goat herd: tissue distribution of disease-associated prp and effect of prnp genotype and age. | following a severe outbreak of clinical scrapie in 2006-2007, a large dairy goat herd was culled and 200 animals were selected for post-mortem examinations in order to ascertain the prevalence of infection, the effect of age, breed and prnp genotype on the susceptibility to scrapie, the tissue distribution of diseaseassociated prp (prp(d)), and the comparative efficiency of different diagnostic methods. as determined by immunohistochemical (ihc) examinations with bar224 prp antibody, the prevale ... | 2009 | 19686637 |
| quantitative reverse-transcription polymerase chain reaction analysis of alzheimer's-associated genes in mouse scrapie. | prion and alzheimer's diseases are two apparently distinct disorders; however, the two proteinaceous species implicated in disease progression share a number of common features. in prion diseases a beta-rich conformer of the prion protein is the key molecule in the pathogenesis of prion disease, whereas in alzheimer's disease neurotoxicity is associated with the amyloid-beta peptide. these two molecules share common structural features and post-translational processing events and both undergo st ... | 2009 | 19697242 |
| p.asn176lys and p.met137thr dimorphisms of the prnp gene significantly decrease the susceptibility to classical scrapie in arq/arq sheep. | in this study, we investigated the susceptibility to scrapie of sarda breed sheep carrying the genotype arq/arq with additional polymorphisms at the prnp gene. to do this, we examined 256 scrapie-affected sheep and 320 flock-mate negative controls from 24 flocks. logistic regression analysis demonstrated that sheep carrying the arq/arq genotype with additional dimorphisms had lower risk of becoming scrapie affected when compared with those with arq/arq(wildtype) genotype. arq/arq genotypes that ... | 2009 | 19706028 |
| influence of prion strain on prion protein adsorption to soil in a competitive matrix. | it is likely that the soil environment serves as a stable reservoir of infectious chronic wasting disease (cwd) and scrapie prions, as well as a potential reservoir of bovine spongiform encephalopathy (bse, or "mad cow" disease). prion adsorption to soil may play an important role in prion mobility, proteolysis, and infectivity. differences in prp environmental fate are possible due to the strain- and species-dependent structure of prp(sc). kinetic and isothermal studies of prp adsorption to san ... | 2009 | 19708348 |
| analysis of protein levels of 24 cytokines in scrapie agent-infected brain and glial cell cultures from mice differing in prion protein expression levels. | activation of microglia and astroglia is seen in many neurodegenerative diseases including prion diseases. activated glial cells produce cytokines as a protective response against certain pathogens and as part of the host inflammatory response to brain damage. in addition, cytokines might also exacerbate tissue damage initiated by other processes. in the present work using multiplex assays to analyze protein levels of 24 cytokines in scrapie agent-infected c57bl/10 mouse brains, we observed elev ... | 2009 | 19710140 |
| prp expression, prpsc accumulation and innervation of splenic compartments in sheep experimentally infected with scrapie. | in prion disease, the peripheral expression of prp(c) is necessary for the transfer of infectivity to the central nervous system. the spleen is involved in neuroinvasion and neural dissemination in prion diseases but the nature of this involvement is not known. the present study undertook the investigation of the spatial relationship between sites of prp(sc) accumulation, localisation of nerve fibres and prp(c) expression in the tissue compartments of the spleen of scrapie-inoculated and control ... | 2009 | 19727393 |
| co-existence of scrapie prion protein types 1 and 2 in sporadic creutzfeldt-jakob disease: its effect on the phenotype and prion-type characteristics. | five phenotypically distinct subtypes have been identified in sporadic creutzfeldt-jakob disease (scjd), based on the methionine/valine polymorphic genotype of codon 129 of the prion protein (prp) gene and the presence of either one of the two protease k-resistant scrapie prion protein (prp(sc)) types identified as 1 and 2. the infrequent co-existence of both prp(sc) types in the same case has been known for a long time. recently, it has been reported, using type-specific antibodies, that the pr ... | 2009 | 19734292 |
| classical sheep scrapie in great britain: spatial analysis and identification of environmental and farm-related risk factors. | previous studies suggest that the spatial distribution of classical sheep scrapie in great britain is uneven and that certain flock characteristics may be associated with occurrence of the disease. however, the existence of areas of high and low disease-risk may also result from differences in the spatial distribution of environmental characteristics. in this study we explored the spatial pattern of classical scrapie in great britain between 2002 and 2005 and investigated the association between ... | 2009 | 19737376 |
| two adjacent nuclear factor-binding domains activate expression from the human prnp promoter. | the transmissible spongiform encephalopathies (tses) comprise a group of fatal degenerative neurological diseases in humans and other mammals. after infection, the cellular prion protein isoform prpc is converted to the pathological prpsc scrapie isoform. the continued conversion of prpc to prpsc requires de novo endogenous prp synthesis for disease progression. the human prion protein gene (prnp) promoter was therefore investigated to identify regulatory elements that could serve as targets for ... | 2009 | 19740434 |
| asymptomatic deer excrete infectious prions in faeces. | infectious prion diseases-scrapie of sheep and chronic wasting disease (cwd) of several species in the deer family-are transmitted naturally within affected host populations. although several possible sources of contagion have been identified in excretions and secretions from symptomatic animals, the biological importance of these sources in sustaining epidemics remains unclear. here we show that asymptomatic cwd-infected mule deer (odocoileus hemionus) excrete cwd prions in their faeces long be ... | 2009 | 19741608 |
| repetitive immunization enhances the susceptibility of mice to peripherally administered prions. | the susceptibility of humans and animals to prion infections is determined by the virulence of the infectious agent, by genetic modifiers, and by hitherto unknown host and environmental risk factors. while little is known about the latter two, the activation state of the immune system was surmised to influence prion susceptibility. here we administered prions to mice that were repeatedly immunized by two initial injections of cpg oligodeoxynucleotides followed by repeated injections of bovine se ... | 2009 | 19779609 |
| prp genotype: a flock-level risk factor for scrapie? | previous epidemiological studies of risk factors for classical scrapie at flock level have identified a variety of management and purchase related variables, along with increased flock size and, in some cases, breed effects. although known as a risk factor at the individual animal level, prp genotype frequencies at flock level have not yet been studied. in an unmatched case-control study, three measures of flock-level prion protein (prp) frequency estimates were investigated with respect to the ... | 2009 | 19783057 |
| the effects of host age on follicular dendritic cell status dramatically impair scrapie agent neuroinvasion in aged mice. | following peripheral exposure, many transmissible spongiform encephalopathy (tse) agents accumulate first in lymphoid tissues before spreading to the cns (termed neuroinvasion) where they cause neurodegeneration. early tse agent accumulation upon follicular dendritic cells (fdcs) in lymphoid follicles appears critical for efficient neuroinvasion. most clinical cases of variant creutzfeldt-jakob disease have occurred in young adults, although the reasons behind this apparent age-related susceptib ... | 2009 | 19786551 |
| glypican-1 mediates both prion protein lipid raft association and disease isoform formation. | in prion diseases, the cellular form of the prion protein, prp(c), undergoes a conformational conversion to the infectious isoform, prp(sc). prp(c) associates with lipid rafts through its glycosyl-phosphatidylinositol (gpi) anchor and a region in its n-terminal domain which also binds to heparan sulfate proteoglycans (hspgs). we show that heparin displaces prp(c) from rafts and promotes its endocytosis, suggesting that heparin competes with an endogenous raft-resident hspg for binding to prp(c). ... | 2009 | 19936054 |
| visual pathology in animal prion diseases. | prion diseases, also known as the transmissible spongiform encephalopathies (tses), are a group of slowly developing neurodegenerations occurring in human and animals. prion diseases can be transferred between animals, humans, from humans to animals, and from animals to humans. as a result, the central nervous system is attacked, resulting in microglia activation, astrocytosis, prion plaque deposition, and neuronal degeneration. prion also targets on the eye and brain visual system. in scrapie-i ... | 2009 | 19795355 |
| transmissibility of atypical scrapie in ovine transgenic mice: major effects of host prion protein expression and donor prion genotype. | atypical scrapie or nor98 has been identified as a transmissible spongiform encephalopathy (tse) that is clearly distinguishable from classical scrapie and bse, notably regarding the biochemical features of the protease-resistant prion protein prp(res) and the genetic factors involved in susceptibility to the disease. in this study we transmitted the disease from a series of 12 french atypical scrapie isolates in a transgenic mouse model (tgovprp4) overexpressing in the brain approximately 0.25, ... | 2009 | 19806224 |
| prion protein detection in serum using micromechanical resonator arrays. | prion proteins that have transformed from their normal cellular counterparts (prp(c)) into infectious form (prp(res)) are responsible for causing progressive neurodegenerative diseases in numerous species, such as bovine spongiform encephalopathy (bse) in cattle (also known as mad cow disease), scrapie in sheep, and creutzfeldt-jakob disease (cjd) in humans. due to a possible link between bse and cjd it is highly desirable to develop non-invasive and ante mortem tests for the detection of prion ... | 2009 | 19836525 |
| design, synthesis, and structure-activity relationship of indole-3-glyoxylamide libraries possessing highly potent activity in a cell line model of prion disease. | transmissible spongiform encephalopathies (tses) are a family of invariably fatal neurodegenerative disorders for which no effective curative therapy currently exists. we report here the synthesis of a library of indole-3-glyoxylamides and their evaluation as potential antiprion agents. a number of compounds demonstrated submicromolar activity in a cell line model of prion disease together with a defined structure-activity relationship, permitting the design of more potent compounds that effecte ... | 2009 | 19842664 |
| manganese enhances prion protein survival in model soils and increases prion infectivity to cells. | prion diseases are considered to be transmissible. the existence of sporadic forms of prion diseases such as scrapie implies an environmental source for the infectious agent. this would suggest that under certain conditions the prion protein, the accepted agent of transmission, can survive in the environment. we have developed a novel technique to extract the prion protein from soil matrices. previous studies have suggested that environmental manganese is a possible risk factor for prion disease ... | 2009 | 19844576 |
| adoptive transfer of t lymphocytes sensitized against the prion protein attenuates prion invasion in scrapie-infected mice. | there is to date no effective way of preventing or curing neurodegenerative diseases such as alzheimer disease or transmissible spongiform encephalopathies. the idea of treating those conditions by immunological approaches has progressively emerged over the last ten years. encouraging results have been reported in alzheimer disease and in peripheral forms of mouse prion diseases following passive injection of abs or active immunization against the peptides or proteins presumably at the origin of ... | 2009 | 19846876 |
| spatial distribution of the active surveillance of sheep scrapie in great britain: an exploratory analysis. | this paper explores the spatial distribution of sampling within the active surveillance of sheep scrapie in great britain. we investigated the geographic distribution of the birth holdings of sheep sampled for scrapie during 2002 - 2005, including samples taken in abattoir surveys (c. 83,100) and from sheep that died in the field ("fallen stock", c. 14,600). we mapped the birth holdings by county and calculated the sampling rate, defined as the proportion of the holdings in each county sampled b ... | 2009 | 19607705 |
| selective presynaptic degeneration in the synaptopathy associated with me7-induced hippocampal pathology. | intrahippocampal injection of the murine modified scrapie (me7) induces a model of prion disease in vivo. animals inoculated with me7 brain homogenate were compared to controls at 8, 12 and 21 weeks. the data show that the accumulation of misfolded prion (prp(sc)) coincided with selective reduction in presynaptic protein expression early in disease. this loss is independent of a change in the number of cell bodies in ca3 that provide the major presynaptic input to the stratum radiatum. electron ... | 2009 | 19362593 |
| characterization of a us sheep scrapie isolate with short incubation time. | scrapie is a naturally occurring fatal neurodegenerative disease of sheep and goats. susceptibility to the disease is partly dependent upon the genetic makeup of the host. in a previous study it was shown that sheep intracerebrally inoculated with us scrapie inoculum (no. 13-7) developed terminal disease within an average of 19 months. we have since produced an inoculum, no. x124 from pooled brains of us-origin sheep scrapie, that results in incubations nearly threefold shorter. the present stud ... | 2009 | 19605918 |
| two unusual bovine spongiform encephalopathy cases detected in great britain. | bovine spongiform encephalopathy (bse) was first identified in great britain (gb) in 1986 and was subsequently detected in many other countries, worldwide. a decade after the start of the bovine epidemic, the first cases of new variant creutzfeldt-jakob disease (vcjd) in humans were linked to probable ingestion of bse infected tissue, highlighting a new zoonotic disease. an abnormal protease-resistant protein (prp(res)) in a diseased subject, derived from a post-translational change of a normal ... | 2009 | 19497088 |
| reduction of prion infectivity and levels of scrapie prion protein by lithium aluminum hydride: implications for rna in prion diseases. | previous studies indicate that rna may be required for proteinase-resistant prion protein (prp) amplification and for infectious prion formation in vitro, suggesting that rna molecules may function as cellular cofactors for abnormal prp (prpsc) formation and become part of the structure of the infectious agent. to address this question, we used chemicals that can cleave phosphodiester bonds of rna and assessed their effects on the infectious agent. lithium aluminum hydride, a reducing agent that ... | 2009 | 19606066 |
| therapeutic interventions ameliorating prion disease. | of the many unresolved issues in relation to prion diseases, effective treatments remain an elusive exigency, although some progress has been made. this review describes disease-ameliorating therapeutic strategies reported to date in animal models of prion disease, as well as providing a brief overview of selected completed human treatment trials. included in vivo studies have been broadly dichotomized according to the time of introduction of the treatment in relation to animal inoculation and a ... | 2009 | 19622059 |
| state-of-the-art review of goat tse in the european union, with special emphasis on prnp genetics and epidemiology. | scrapie is a fatal, neurodegenerative disease of sheep and goats. it is also the earliest known member in the family of diseases classified as transmissible spongiform encephalopathies (tse) or prion diseases, which includes creutzfeldt-jakob disease in humans, bovine spongiform encephalopathy (bse), and chronic wasting disease in cervids. the recent revelation of naturally occurring bse in a goat has brought the issue of tse in goats to the attention of the public. in contrast to scrapie, bse p ... | 2009 | 19505422 |
| peptide nmhrypnq of the cellular prion protein (prp(c)) inhibits aggregation and is a potential key for understanding prion-prion interactions. | pathogenesis of transmissible spongiform encephalopathies is correlated with a conversion of the normal cellular form of the prion protein (prp(c)) into the abnormal isoform (scrapie form of prp). contact of the normal prp with its abnormal isoform, the scrapie form of prp, induces the transformation. knowledge of molecules that inhibit such contacts leads to an understanding of the mechanism of the aggregation, and these molecules may serve as leads for drugs against transmissible spongiform en ... | 2009 | 19607841 |
| neuroinvasion in sheep transmissible spongiform encephalopathies: the role of the haematogenous route. | it is generally believed that after oral exposure to transmissible spongiform encephalopathy (tse) agents, neuroinvasion occurs via the enteric nervous system (ens) and the autonomic nervous system. as a result, the dorsal motor nucleus of the vagus nerve is the initial point of disease-associated prion protein (prp(d)) accumulation in the brain. hypothesis and aim: if direct ens invasion following oral infection results in an early and specific brain targeting for prp(d) accumulation, such topo ... | 2009 | 19473292 |
| abnormal prion protein is associated with changes of plasma membranes and endocytosis in bovine spongiform encephalopathy (bse)-affected cattle brains. | transmissible spongiform encephalopathies (tses) or prion diseases are fatal neurodegenerative diseases of man and animals characterized by vacuolation and gliosis of neuropil and the accumulation of abnormal isoforms of a host protein known as prion protein (prp). it is widely assumed that the abnormal isoforms of prp (prp(d), disease-specific form of prp) are the proximate cause of neurodegeneration. | 2009 | 19473293 |
| reflections on a half-century in the field of transmissible spongiform encephalopathy. | the subject of transmissible spongiform encephalopathy may properly be said to have begun with the experimental transmission of scrapie by cuillé and chelle in 1936, although creutzfeldt and jakob had described the disease that bears their names in 1920-21. thirty more years passed before the human disease was also shown to be transmissible, in 1966, and the following half century has seen the field move from classical biology to molecular biology and genetics, and from 'slow virus' to host-enco ... | 2009 | 19618333 |
| shadoo (sprn) and prion disease incubation time in mice. | prion diseases are transmissible neurodegenerative disorders of mammalian species and include scrapie, bovine spongiform encephalopathy (bse), and variant creutzfeldt-jakob disease (vcjd). the prion protein (prp) plays a key role in the disease, with coding polymorphism in both human and mouse influencing disease susceptibility and incubation time, respectively. other genes are also thought to be important and a plausible candidate is sprn, which encodes the prp-like protein shadoo (sho). sho is ... | 2009 | 19513788 |
| immunohistochemical characterisation of classical scrapie neuropathology in sheep. | neuroinflammation elicited by prp(res) (resistant prion protein [prp]) deposits in the central nervous system (cns) has been shown to involve cellular and oxidative stress responses in bovine spongiform encephalopathy (bse) as well as in several murine models of transmissible spongiform encephalopathy (tse). additionally, deregulation of water homeostasis has been suggested to be a further component of the spongiform changes observed in tses. the aim of the present study was to characterize the ... | 2009 | 19515381 |
| genetic analysis of the sprn gene in ruminants reveals polymorphisms in the alanine-rich segment of shadoo protein. | prion diseases in ruminants, especially sheep scrapie, cannot be fully explained by prnp genetics, suggesting the influence of a second modulator gene. the sprn gene is a good candidate for this role. the sprn gene encodes the shadoo protein (sho) which has homology to the prnp gene encoding prion protein (prp). murine sho has a similar neuroprotective activity to prp and sprn gene variants are associated with human prion disease susceptibility. sprn gene sequences were obtained from 14 species ... | 2009 | 19515828 |
| variable levels of 37-kda/67-kda laminin receptor (rpsa) mrna in ovine tissues: potential contribution to the regulatory processes of prpsc propagation? | the 37-kda laminin receptor precursor/67-kda laminin receptor (lrp/lr, also known as ribosomal protein sa, rpsa) has been reported to be involved in cancer development and prion internalization. previous studies have shown that the lrp/lr is expressed in a wide variety of tissues. in particular, expression of lrp/lr mrna may be closely related to the degree of prp(sc) propagation. this study presents a detailed investigation of the lrp/lr mrna expression levels in eleven normal ovine tissues. us ... | 2009 | 19544211 |
| prion removal effect of a specific affinity ligand introduced into the manufacturing process of the pharmaceutical quality solvent/detergent (s/d)-treated plasma octaplaslg. | a new chromatographic step for the selective binding of abnormal prion protein (prp(sc)) was developed, and optimization for prp(sc) capture was achieved by binding to an affinity ligand attached to synthetic resin particles. this step was implemented into the manufacturing process of the solvent/detergent (s/d)-treated biopharmaceutical quality plasma octaplas to further improve the safety margin in terms of risk for variant creutzfeldt-jakob disease (vcjd) transmission. | 2009 | 19548963 |
| the cellular prion protein and its role in alzheimer disease. | the cellular prion protein (prp(c)) is a membrane-bound glycoprotein especially abundant in the central nervous system (cns). the scrapie prion protein (prp(sc,) also termed prions) is responsible of transmissible spongiform encephalopathies (tse), a group of neurodegenerative diseases which affect humans and other mammal species, although the presence of prp(c) is needed for the establishment and further evolution of prions. the present work compares the expression and localization of prp(c) be ... | 2009 | 19556894 |
| prion protein nmr structure from tammar wallaby (macropus eugenii) shows that the beta2-alpha2 loop is modulated by long-range sequence effects. | nmr structures are presented for the recombinant construct of residues 121-230 from the tammar wallaby (macropus eugenii) prion protein (prp) twprp(121-230) and for the variant mouse prps mprp[y225a,y226a](121-231) and mprp[v166a](121-231) at 20 degrees c and ph 4.5. all three proteins exhibit the same global architecture as seen in other recombinant prp(c)s (cellular isoforms of prp) and shown to prevail in natural bovine prp(c). special interest was focused on a loop that connects the beta2-st ... | 2009 | 19393664 |
| elimination capacity of a tse-model agent in the manufacturing process of alphanate/fanhdi, a human factor viii/vwf complex concentrate. | the variant creutzfeldt-jakob disease (vcjd) is a transmissible spongiform encephalopathy (tse), mainly present in the uk and is associated with the ingestion of bovine products affected with bovine spongiform encephalopathy. manufacturers of biological products must investigate the ability of their production processes to remove tse agents. we studied the purification steps in the manufacturing process of two fviii/vwf concentrates (alphanate) and fanhdi in their ability to eliminate an experim ... | 2009 | 19563480 |
| prnp haplotype distribution in moroccan goats. | susceptibility/resistance to scrapie in sheep and goats is influenced by host prion protein gene (prnp) genotype. in this study, we report the analysis of prion protein gene polymorphisms in 137 goats of two moroccan populations: d'man and chaouni. we found seven previously described amino acid polymorphisms at codons 37, 127, 137, 142, 154, 222 and 240, as well as three known silent mutations. in addition, we identified three new allelic variants: 101r and 139s in d'man goats and 145d in d'man ... | 2009 | 19397523 |
| distinct spatial activation of intrinsic and extrinsic apoptosis pathways in natural scrapie: association with prion-related lesions. | neurodegeneration and gliosis are the main neuropathological features of prion diseases. however, the molecular mechanisms involved in these processes remain unclear. several studies have demonstrated changes in the expression of apoptotic factors and inflammatory cytokines in animals with experimental infection. here we present the expression profiles of 15 genes implicated in the intrinsic and extrinsic apoptotic pathways in the central nervous systems of sheep naturally infected with scrapie. ... | 2009 | 19401142 |
| prion protein (prp) knock-out mice show altered iron metabolism: a functional role for prp in iron uptake and transport. | despite overwhelming evidence implicating the prion protein (prp) in prion disease pathogenesis, the normal function of this cell surface glycoprotein remains unclear. in previous reports we demonstrated that prp mediates cellular iron uptake and transport, and aggregation of prp to the disease causing prp-scrapie (prp(sc)) form results in imbalance of iron homeostasis in prion disease affected human and animal brains. here, we show that selective deletion of prp in transgenic mice (prp(ko)) alt ... | 2009 | 19568430 |
| a case-control study on the origin of atypical scrapie in sheep, france. | a matched case-control study (95 cases and 220 controls) was designed to study risk factors for atypical scrapie in sheep in france. we analyzed contacts with animals from other flocks, lambing and feeding practices, and exposure to toxic substances. data on the prnp genotype were collected for some case and control animals and included in a complementary analysis. sheep dairy farms had a higher risk for scrapie (odds ratio [or] 15.1, 95% confidence interval [ci] 3.3-69.7). lower risk was associ ... | 2009 | 19402956 |
| comparison of strategies for substantiating freedom from scrapie in a sheep flock. | the public health threat represented by a potential circulation of bovine spongiform encephalopathy agent in sheep population has led european animal health authorities to launch large screening and genetic selection programmes. if demonstrated, such a circulation would have dramatic economic consequences for sheep breeding sector. in this context, it is important to evaluate the feasibility of qualification procedures that would allow sheep breeders demonstrating their flock is free from scrapi ... | 2009 | 19405956 |
| prion disease development in slow wallerian degeneration (wld(s)) mice. | axon destruction represents one aspect of prion disease-associated neurodegeneration. we characterized here the scrapie infection of wld(s)-mice in comparison to wild-type c57bl/6 controls to determine whether mechanisms involved in wallerian degeneration contribute to disease development in this murine model system. the wld(s) mutation had neither an effect on survival times, nor on typical hallmarks of a prion infection like deposition of misfolded prp(sc) and glia activation. at the ultrastru ... | 2009 | 19429141 |
| surround optical fiber immunoassay (sofia): an ultra-sensitive assay for prion protein detection. | we describe the development of a new technology (sofia) and demonstrate its utility by establishing a sensitive and specific assay for prp(sc). sofia is a surround optical fiber immunoassay which is comprised of a set of specific monoclonal antibodies and comprehensive capture of high energy fluorescence emission. in its current format, this system is capable of detecting less than 10 attogram (ag) of hamster, sheep and deer recombinant prp. approximately 10 ag of prp(sc) from 263 k-infected ham ... | 2009 | 19442839 |
| interlaboratory trial on tse rapid tests for the control of the italian scrapie surveillance network. | scrapie, a neurodegenerative disease of sheep and goats and one of several transmissible spongiform encephalopathies (tses) has been subject to mandatory active surveillance in eu through rapid testing since 2002. regulation ec/999/2001 on tse surveillance requires that each member state's national reference laboratory for tse periodically verifies diagnostic standards and methods by comparative testing. in 2007 the italian reference centre carried out the first ring trial for classical scrapie ... | 2009 | 19457624 |
| blood chimerism confounds genetic relative susceptibility testing for classical scrapie in sheep. | classical scrapie disease is a transmissible spongiform encephalopathy of sheep that is enzootic in the united states. susceptibility of sheep to classical scrapie is linked to single nucleotide polymorphisms in the prion protein gene (prnp), forming the basis for genetic testing strategies used by national efforts to eradicate scrapie. such efforts are occasionally hampered by inconclusive results stemming from the detection of "complex" genotypes. naturally occurring cases of ovine chimerism a ... | 2009 | 19407081 |
| doxorubicin and congo red effectiveness on prion infectivity in golden syrian hamster. | the effect of doxorubicin and congo red on prion protein (prp) infectivity in experimental scrapie was studied to better understand the effect of these compounds in prion diseases and to establish whether a dose-response correlation exists for congo red. this was performed in order to test the effectiveness of compounds that may easily be used in human prion diseases. brain homogenate containing membrane bound prpsc monomers was used as inoculum and was previously incubated with doxorubicin 10(- ... | 2009 | 19596920 |
| hyperefficient prp sc amplification of mouse-adapted bse and scrapie strain by protein misfolding cyclic amplification technique. | abnormal forms of prion protein (prp(sc)) accumulate via structural conversion of normal prp (prp(c)) in the progression of transmissible spongiform encephalopathy. under cell-free conditions, the process can be efficiently replicated using in vitro prp(sc) amplification methods, including protein misfolding cyclic amplification. these methods enable ultrasensitive detection of prp(sc); however, there remain difficulties in utilizing them in practice. for example, to date, several rounds of prot ... | 2009 | 19459939 |
| effects of clioquinol on memory impairment and the neurochemical modifications induced by scrapie infection in golden hamsters. | prion protein (prp) is a glycoprotein expressed on the surface of neurons and glial cells. its pathological isoform (prp(res)) is protease resistant, and involved in the pathogenesis of a number of transmissible encephalopathies (tses). one common feature of neurodegenerative diseases, including tses, is oxidative stress, which may be responsible not only for the dysfunction or death of neuronal cells, but also cognitive deficits. clioquinol (5-chloro-7-iodo-8-quinolinol) chelates zinc and coppe ... | 2009 | 19463795 |
| detection of classical and atypical/nor98 scrapie by the paraffin-embedded tissue blot method. | the paraffin-embedded tissue (pet) blot method was used to investigate sections of the central nervous system and lymphatic tissues from 24 cases of classical scrapie and 25 cases of atypical/nor98 scrapie in sheep and four healthy control sheep. the pet blot detected deposits of prp(sc) in the brain tissue of all 49 sheep with scrapie but no prp(sc) labelling could be detected in the control sheep. by contrast, not all the atypical/nor98 scrapie cases were detectable by immunohistochemistry. th ... | 2009 | 19483208 |
| design of anti- and pro-aggregation variants to assess the effects of methionine oxidation in human prion protein. | prion disease is characterized by the alpha-->beta structural conversion of the cellular prion protein (prp(c)) into the misfolded and aggregated "scrapie" (prp(sc)) isoform. it has been speculated that methionine (met) oxidation in prp(c) may have a special role in this process, but has not been detailed and assigned individually to the 9 met residues of full-length, recombinant human prp(c) [rhprp(c)(23-231)]. to better understand this oxidative event in prp aggregation, the extent of periodat ... | 2009 | 19416900 |
| prions are secreted in milk from clinically normal scrapie-exposed sheep. | the potential spread of prion infectivity in secreta is a crucial concern for prion disease transmission. here, serial protein misfolding cyclic amplification (spmca) allowed the detection of prions in milk from clinically affected animals as well as scrapie-exposed sheep at least 20 months before clinical onset of disease, irrespective of the immunohistochemical detection of protease-resistant prp(sc) within lymphoreticular and central nervous system tissues. these data indicate the secretion o ... | 2009 | 19494004 |
| identification of an intracellular site of prion conversion. | prion diseases are fatal, neurodegenerative disorders in humans and animals and are characterized by the accumulation of an abnormally folded isoform of the cellular prion protein (prp(c)), denoted prp(sc), which represents the major component of infectious scrapie prions. characterization of the mechanism of conversion of prp(c) into prp(sc) and identification of the intracellular site where it occurs are among the most important questions in prion biology. despite numerous efforts, both of the ... | 2009 | 19424437 |
| identification of proteins co-purifying with scrapie infectivity. | prp(c), the cellular isoform of prion protein, is widely expressed in most tissues. despite its involvement in several bioprocesses it still has no apparent physiological role. during propagation of transmissible spongiform encephalopathies, prp(c) is converted to the pathological isoform, prp(sc), in a process believed to be mediated by unknown host factors. prp(sc) has altered biochemical properties and forms amyloid aggregates that display infectious characteristics. prp(sc) is also the major ... | 2009 | 19367687 |
| role of the lymphoreticular system in prion neuroinvasion from the oral and nasal mucosa. | prion neuroinvasion from peripheral tissues involves agent replication in the lymphoreticular system (lrs) prior to entry into the nervous system. this study investigated the role of the lrs in prion neuroinvasion from the oral and nasal mucosa in wild-type and immunodeficient mice and in hamsters infected with the hy and dy strains of the transmissible mink encephalopathy (tme) agent. following inoculation at neural sites, all hosts were susceptible to prion disease and had evidence of prion in ... | 2009 | 19369351 |
| the conversion of helix h2 to beta-sheet is accelerated in the monomer and dimer of the prion protein upon t183a mutation. | the conversion of the prion protein (prp) from its cellular form, prpc, to its pathogenic scrapie form, prpsc, is a key event in neurodegenerative transmissible spongiform encephalopathies such as creutzfeldt-jakob disease (cjd). prpc is characterized by three helices (h1-h3) and a small antiparallel beta-sheet. one working hypothesis for tse causation is that oligomeric forms of prp are the proximate neurotoxic agents. because these states are transient in character, current experimental studie ... | 2009 | 19371053 |
| burrowing: a sensitive behavioural assay, tested in five species of laboratory rodents. | in the burrowing test, mice or rats spontaneously empty a tube filled with food pellets, gravel or other substances. the test is extremely simple to perform, the apparatus is inexpensive and readily constructed. it exploits a natural rodent behaviour, provides quantitative data under controlled laboratory conditions, and has proved extremely sensitive to prion disease in mice (mus musculus), cytokines in rats (rattus norvegicus), lipopolysaccharide in mice and rats, strain differences and brain ... | 2009 | 19373978 |
| comparative prion disease gene expression profiling using the prion disease mimetic, cuprizone. | identification of genes expressed in response to prion infection may elucidate biomarkers for disease, identify factors involved in agent replication, mechanisms of neuropathology and therapeutic targets. although several groups have sought to identify gene expression changes specific to prion disease, expression profiles rife with cell population changes have consistently been identified. cuprizone, a neurotoxicant, qualitatively mimics the cell population changes observed in prion disease, res ... | 2009 | 19535908 |
| anti-prp mab 6d11 suppresses prp(sc) replication in prion infected myeloid precursor line fdc-p1/22l and in the lymphoreticular system in vivo. | the pathogenesis of prion diseases is related to conformational transformation of cellular prion protein (prp(c)) into a toxic, infectious, and self-replicating conformer termed prp(sc). following extracerebral inoculation, the replication of prp(sc) is confined for months to years to the lymporeticular system (lrs) before the secondary cns involvement results in occurrence of neurological symptoms. therefore, replication of prp(sc), in the early stage of infection can be targeted by therapeutic ... | 2009 | 19385058 |
| glycosylation-related gene expression profiling in the brain and spleen of scrapie-affected mouse. | a central event in the formation of infectious prions is the conformational change of a host-encoded glycoprotein, prp(c), into a pathogenic isoform, prp(sc). the molecular requirements for efficient prp conversion remain unknown. altered glycosylation has been linked to various pathologies and the n-glycans harbored by two prion protein isoforms are different. in order to search for glycosylation-related genes that could mark prion infection, we used a glycosylation-dedicated microarray that al ... | 2009 | 19386898 |
| accumulation and dissemination of prion protein in experimental sheep scrapie in the natural host. | in order to study the sites of uptake and mechanisms of dissemination of scrapie prions in the natural host under controlled conditions, lambs aged 14 days and homozygous for the vrq allele of the prp gene were infected by the oral route. infection occurred in all lambs with a remarkably short and highly consistent incubation period of approximately 6 months. challenge of lambs at approximately eight months of age resulted in disease in all animals, but with more variable incubation periods aver ... | 2009 | 19243608 |
| rapid folding of the prion protein captured by pressure-jump. | the conversion of the cellular form of the prion protein (prp(c)) to an altered disease state, generally denoted as scrapie isoform (prp(sc)), appears to be a crucial molecular event in prion diseases. the details of this conformational transition are not fully understood, but it is perceived that they are associated with misfolding of prp or its incapacity to maintain the native fold during its cell cycle. here we present a tryptophan mutant of prp (f198w), which has enhanced fluorescence sensi ... | 2009 | 19255752 |
| frequency and distribution of nerves in scrapie-affected and unaffected peyer's patches and lymph nodes. | transmission of sheep scrapie and some other prion diseases, including variant creutzfeldt-jakob disease of man, probably occurs via the oral route. a disease-associated variant of the host-coded prion protein (prp(d)) accumulates in germinal center follicles of lymphoid tissues, including peyer's patches of the gut, where it can be detected before its accumulation in the central nervous system. to investigate the potential role of lymphoid tissue nerves in neuroinvasion, we used immunohistochem ... | 2009 | 19261634 |
| ovine prnp untranslated region and promoter haplotype diversity. | the diversity and possible contribution of non-coding regions of the prion protein (prp) gene (prnp) to transmissible spongiform encephalopathy susceptibility and prp regulation are not fully known. this study defined ten ovine prnp promoters and five untranslated region (utr) haplotypes found in atypical and classical scrapie cases and healthy control sheep. a greater diversity of promoter and utr haplotypes was observed in conjunction with the arq prp allele (seven promoter and four utr haplot ... | 2009 | 19264598 |
| use of epidemiologic information in targeted surveillance for population inference. | epidemiologic information, including animal characteristics (e.g., observable risk factors or clinical signs) predisposing to animal disease, is frequently used for design of targeted surveillance systems, but this information is infrequently used for population inference. in this study, we report the evaluation of use of epidemiologic information for population inference in targeted surveillance in three animal disease scenarios. we adapted sampling theory using monte carlo methods to determine ... | 2009 | 19269705 |
| a new genotyping strategy for efficient scoring of closely positioned snps in the ovine prion protein gene. | amino-acid polymorphisms of the ovine prion protein have been known to influence susceptibility to scrapie for many years. recently, a role in both classical and atypical scrapie was assigned to new mutations, increasing the overall number of polymorphisms of interest for breeding plans. besides, the high number and density of polymorphisms in the prion protein gene (prp) and the presence of unusual mutations in some breeds hampers genotyping methods, making multiplexing difficult and sometimes ... | 2009 | 19272344 |
| [research progress on genetic diversity of sheep prnp and resistance breeding]. | prion protein (prp) is a pathogeny identified in recent years, which infects both mankind and other mammals. it has been proved that prp is a sole protein able to duplicate and propagate with itself. prp can express in many tissues and has important physiological functions in many species of animals. the conformation change of prp is the origin of transmissible spongiform encephalopathies (tses). it has been proved that the sheep genetic diversity of prion protein gene (prnp) is significantly as ... | 2009 | 19273420 |
| the number of octapeptide repeat affects the expression and conversion of prion protein. | the human prion protein (prp) has five copies of an octapeptide repeat (or). the mutant prp with 6-14 or causes the genetic form of creutzfeldt-jakob disease (cjd). to determine the influence of or on the conversion of prp, we examined the conversion efficiency of mouse mutant prp molecules with 1-16 or in scrapie-infected cells. the expression level of mutant prp and the glycoform ratio of the abnormal isoform of prp (prp(sc)) were affected by the number of or. the conversion efficiency was alm ... | 2009 | 19318088 |