Publications

TitleAbstractYear(sorted descending)
Filter
PMID
Filter
conserved properties of human and bovine prion strains on transmission to guinea pigs.the first transmissions of human prion diseases to rodents used guinea pigs (gps, cavia porcellus). later, transgenic mice expressing human or chimeric human/mouse prp replaced gps, but the small size of the mouse limits some investigations. to investigate the fidelity of strain-specific prion transmission to gps, we inoculated 'type 1' and 'type 2' prion strains into gps, and we measured the incubation times and determined the strain-specified size of the unglycosylated, protease-resistant (r) ...201121727894
mutation directional selection sheds light on prion pathogenesis.as mutations in the prnp gene account for human hereditary prion diseases (prds), it is crucial to elucidating how these mutations affect the central pathogenic conformational transition of normal cellular prion protein (prp(c)) to abnormal scrapie isoform (prp(sc)). many studies proposed that these pathogenic mutations may make prp more susceptible to conformational change through altering its structure stability. by evaluating the most recent observations regarding pathogenic mutations, it was ...201121679685
analysis of nucleic acid chaperoning by the prion protein and its inhibition by oligonucleotides.prion diseases are unique neurodegenerative illnesses associated with the conversion of the cellular prion protein (prp(c)) into the aggregated misfolded scrapie isoform, named prp(sc). recent studies on the physiological role of prp(c) revealed that this protein has probably multiple functions, notably in cell-cell adhesion and signal transduction, and in assisting nucleic acid folding. in fact, in vitro findings indicated that the human prp (huprp) possesses nucleic acid binding and annealing ...201121737432
transcriptional profiling of peripheral lymphoid tissue reveals genes and networks linked to ssbp/1 scrapie pathology in sheep.transmissible spongiform encephalopathies (tses) are slow and progressive neurodegenerative diseases of humans and animals. the major target organ for all tses is the brain but some tse agents are associated with prior accumulation within the peripheral lymphoid system. many studies have examined the effects of scrapie infection on the expression of central nervous system (cns) genes, but this study examines the progression of scrapie pathology in the peripheral lymphoid system and how scrapie i ...201121684093
prion disease detection, pmca kinetics, and igg in urine from sheep naturally/experimentally infected with scrapie and deer with preclinical/clinical chronic wasting disease.prion diseases, also known as transmissible spongiform encephalopathies, are fatal neurodegenerative disorders. low levels of infectious agent and limited, infrequent success of disease transmissibility and prp(sc) detection have been reported with urine from experimentally infected clinical cervids and rodents. we report the detection of prion disease-associated seeding activity (pasa) in urine from naturally and orally infected sheep with clinical scrapie agent and orally infected preclinical ...201121715495
common structural traits across pathogenic mutants of the human prion protein and their implications for familial prion diseases.human (hu) familial prion diseases are associated with about 40 point mutations of the gene coding for the prion protein (prp). most of the variants associated with these mutations are located in the globular domain of the protein. we performed 50-áns of molecular dynamics for each of these mutants to investigate their structure in aqueous solution. overall, 1.6-á++s of molecular dynamics data is presented. the calculations are based on the amber(parm99) force field, which has been shown to repr ...201121689662
assessment of the genetic susceptibility of sheep to scrapie by protein misfolding cyclic amplification and comparison with experimental scrapie transmission studies.the susceptibility of sheep to scrapie is influenced mainly by the prion protein polymorphisms a136v, r154h, and q171r/h. here we analyzed the ability of protein misfolding cyclic amplification (pmca) to model the genetic susceptibility of sheep to scrapie. for this purpose, we studied the efficiency of brain homogenates from sheep with different prp genotypes to support prp(sc) amplification by pmca using an arq/arq scrapie inoculum. the results were then compared with those obtained in vivo us ...201121680531
real-time quaking-induced conversion: a highly sensitive assay for prion detection.we recently developed a new in vitro amplification technology, designated "real-time quaking-induced conversion (rt-quic)", for detection of the abnormal form of prion protein (prpsc) in easily accessible specimens such as cerebrospinal fluid (csf). after assessment of more than 200 csf specimens from japanese and australian patients, we found no instance of a false positive, and more than 80% accuracy for the correct diagnosis of sporadic creutzfeldt-jakob disease (scjd). furthermore, the rt-qu ...201121778820
Bee venom phospholipase A2 prevents prion peptide induced-cell death in neuronal cells.Bee venom phospholipase A2 (bvPLA2) is a prototypic group-áIII enzyme which consists of unique N-terminal and C-terminal domains and a central secretory PLA2 (sPLA2) domain. This sPLA2 domain is highly homologous with human group-áIII sPLA2. Current evidence suggests that group-áIII sPLA2 may affect some neuronal functions, such as neuritogenesis, neurotransmitter release and neuronal survival. The prion diseases are neurodegenerative disorders characterized by the conversion of the normal cellu ...201121701769
Accumulation and aberrant composition of cholesteryl esters in Scrapie-infected N2a cells and C57BL/6 mouse brains.ABSTRACT:201121816038
Molecular cloning and polymorphism analysis of the prion protein gene in Tan sheep of Ningxia, China.The resistance or susceptibility of sheep to scrapie is associated with polymorphisms of the prion protein gene (PRNP), particularly, single nucleotide polymorphisms (SNPs) in amino acid positions 136, 154 and 171. The prion protein (PrP) gene sequence and the deduced amino acid alignment of prion protein in Tan sheep, a local Chinese sheep breed traditionally raised in Ningxia, northwestern China, were determined and variability of the PrP amino acids sequence was analyzed in this study. The Pr ...201121722718
PRNP haplotype and genotype frequencies in Brazilian sheep: Issues for conservation and breeding programs.Polymorphisms of PRNP gene have been strongly correlated to the susceptibility/resistance to scrapie in sheep. Variants at the coding positions 136, 154 and 171 have been the most frequently associated to susceptibility to classical scrapie. The aim of this study was to estimate PRNP haplotype and genotype frequencies in a sample of 1400 sheep from 13 different breeds that are representative of the main production regions in Brazil. A total of four different alleles (ARR, ARQ, AHQ and VRQ) and n ...201121816449
isolation of prion with bse properties from farmed goat.transmissible spongiform encephalopathies are fatal neurodegenerative diseases that include variant creutzfeldt-jakob disease in humans, scrapie in small ruminants, and bovine spongiform encephalopathy (bse) in cattle. scrapie is not considered a public health risk, but bse has been linked to variant creutzfeldt-jakob disease. small ruminants are susceptible to bse, and in 2005 bse was identified in a farmed goat in france. we confirm another bse case in a goat in which scrapie was originally di ...201122172149
th2-polarised prp-specific transgenic t-cells confer partial protection against murine scrapie.several hurdles must be overcome in order to achieve efficient and safe immunotherapy against conformational neurodegenerative diseases. in prion diseases, the main difficulty is that the prion protein is tolerated as a self protein, which prevents powerful immune responses. passive antibody therapy is effective only during early, asymptomatic disease, well before diagnosis is made. if efficient immunotherapy of prion diseases is to be achieved, it is crucial to understand precisely how immune t ...201121909267
ten years of bse surveillance in italy: neuropathological findings in clinically suspected cases.between 2001 and 2010, 244 clinically suspected cases of bovine spongiform encephalopathy (bse) were reported in italy. this report summarizes the neuropathological findings in cattle displaying clinical signs consistent with a diagnosis of bse. all animal specimens were submitted for confirmatory testing; samples testing negative underwent neuropathological examination to establish the differential diagnosis. immunohistochemistry for scrapie prion protein (prpsc) at the level of frontal cortex ...201122083104
effect of prp genotype and route of inoculation on the ability of discriminatory western blot to distinguish scrapie from sheep bovine spongiform encephalopathy.procedures for discriminating scrapie from bovine spongiform encephalopathy (bse) in sheep are relevant to ascertain whether bse has entered the sheep population. this study was aimed at investigating whether the suitability of an official eu discriminative method is affected by the sheep prp genotype and route of infection.201121994325
styryl-based and tricyclic compounds as potential anti-prion agents.prion diseases currently have no effective therapy. these illnesses affect both animal and human populations, and are characterized by the conformational change of a normal self protein prp(c) (c for cellular) to a pathological and infectious conformer, prp(sc) (sc for scrapie). we used a well characterized tissue culture model of prion infection, where mouse neuroblastoma cells (n2a) were infected with 22l prp(sc), to screen compounds for anti-prion activity. in a prior study we designed a libr ...201121931860
Paraffin-embedded tissue blot as a sensitive method for discrimination between classical scrapie and experimental bovine spongiform encephalopathy in sheep.The paraffin-embedded tissue (PET) blot was modified for use as a tool to differentiate between classical scrapie and experimental bovine spongiform encephalopathy (BSE) in sheep. Medulla (obex) from 21 cases of classical scrapie and 6 cases of experimental ovine BSE were used to develop the method such that it can be used as a tool to differentiate between BSE and scrapie in the same way that differential immunohistochemistry (IHC) has been used previously. The differential PET blot successfull ...201121908277
BSE: where are we now? 201121965237
propagation of ovine prions from "poor" transmitter scrapie isolates in ovine prp transgenic mice.ovine prion strains have typically been identified by their transmission properties, which include incubation time and lesion profile, in wild type mice. the existence of scrapie isolates that do not propagate in wild type mice, defined here as "poor" transmitters, are problematic for conventional prion strain typing studies as no incubation time or neuropathology can be recorded. this may arise because of the presence of an ovine prion strain within the original inoculum that does not normally ...201122120785
role of cyclophilin a from brains of prion-infected mice in stimulation of cytokine release by microglia and astroglia in vitro.prion diseases or transmissible spongiform encephalopathy (tse) diseases are typically characterized by deposition of abnormally folded partially protease-resistant host-derived prion protein (prpres), which is associated with activated glia and increased release of cytokines. this neuroinflammatory response may play a role in tse pathogenesis. we previously reported that brain homogenates from prion-infected mice induced cytokine protein release in primary astroglial and microglial cell culture ...201122179611
The structural stability of wild-type horse prion protein.Prion diseases (e.g. Creutzfeldt-Jakob disease (CJD), variant CJD (vCJD), Gerstmann-Straussler-Scheinker syndrome (GSS), Fatal Familial Insomnia (FFI) and Kuru in humans, scrapie in sheep, bovine spongiform encephalopathy (BSE or 'mad-cow' disease) and chronic wasting disease (CWD) in cattles) are invariably fatal and highly infectious neurodegenerative diseases affecting humans and animals. However, by now there have not been some effective therapeutic approaches or medications to treat all the ...201121875155
Inactivation of template-directed misfolding of infectious prion protein by ozone.Misfolded prions (PrP(Sc)) are well known for their resistance to conventional decontamination processes. The potential risk of contamination of the water environment, as a result of disposal of specified risk materials (SRM), has raised public concerns. Ozone is commonly utilized in the water industry for inactivation of microbial contaminants and was tested in this study for its ability to inactivate prions (263K hamster scrapie = PrP(Sc)). Treatment variables included initial ozone dose (7.6- ...201122138993
transcriptional modulation in a leukocyte-depleted splenic cell population during prion disease.prion replication in the periphery precedes neuroinvasion in many experimental rodent scrapie models, and in natural sheep scrapie and chronic wasting disease (cwd) in cervids. prions propagate in the germinal centers of secondary lymphoid organs and are strongly associated with follicular dendritic cells (fdc) and possibly circulating dendritic cells and macrophages. given the importance of lymphoid organs in prion disease transmission and pathogenesis, gene expression studies may reveal host f ...201122043911
prion protein self-interaction in prion disease therapy approaches.transmissible spongiform encephalopathies (tses) or prion diseases are unique disorders that are not caused by infectious micro-organisms (bacteria or fungi), viruses or parasites, but rather seem to be the result of an infectious protein. tses are comprised of fatal neurodegenerative disorders affecting both human and animals. prion diseases cause sponge-like degeneration of neuronal tissue and include (among others) creutzfeldt-jacob disease in humans, bovine spongiform encephalopathy (bse) in ...201122029882
removal of prion infectivity by affinity ligand chromatography during octaplaslg(®) manufacturing - results from animal bioassay studies.background  octaplaslg(®) is a 2nd-generation virus inactivated pooled plasma for infusion. prions are removed by the principle of chromatography, utilizing an affinity ligand gel (lg) developed for binding of prion proteins and their infectivity. the goal of this study was to verify, using the gold standard animal bioassay system, whether or not prion infectivity can be removed by the lg affinity step under conditions used in the routine manufacturing process. materials and methods  aliquots o ...201122070802
Mechanisms of prion disease progression: a chemical reaction network approach.Fatal neurodegenerative diseases such as bovine spongiform encephalopathy in cattle, scrapie in sheep and Creutzfeldt-Jakob disease in humans are caused by prions. Prion is a protein encoded by a normal cellular gene. The cellular form of the prion, namely PrP(C), is benign but can be converted into a disease-causing form (named scrapie), PrP(Sc), by a conformational change from -helix to -sheets. Prions replicate by this conformational change; that is, PrP(Sc) interacts with PrP(C) producing a ...201122129030
Methodology Adaptation of a low-cost medium-throughput genotyping system for ovine prion protein gene polymorphims associated with scrapie.Resistance and susceptibility to scrapie in sheep have been associated with SNPs located at codons 136, 154 and 171 of the prion protein (PRNP) gene. Many countries have sheep breeding programs selecting for resistance to scrapie based on the genotyping of these SNPs. We adapted a fast and robust method for genotyping sheep flocks for these polymorphisms, with reduced costs. Ninety-six samples were genotyped using an adapted SNaPshot PRNP assay, and the results were checked by resequencin ...201122194174
there is no safe dose of prions.understanding the circumstances under which exposure to transmissible spongiform encephalopathies (tses) leads to infection is important for managing risks to public health. based upon ideas in toxicology and radiology, it is plausible that exposure to harmful agents, including tses, is completely safe if the dose is low enough. however, the existence of a threshold, below which infection probability is zero has never been demonstrated experimentally. here we explore this question by combining d ...201121858197
differentiating ovine bse from ch1641 scrapie by serial protein misfolding cyclic amplification.whilst ovine bse displays distinct pathological characteristics to ovine ch1641-like scrapie upon passage in rodents, they have very similar molecular phenotypes. as such, the in vitro differentiation of these strains in routine surveillance programmes presents a significant diagnostic challenge. in this study, using serial protein-misfolding cyclic amplification (spmca), ovine bse was readily amplified in vitro in brain substrates from sheep with v(136)r(154)q(171)/v(136)r(154)q(171) or ahq/ahq ...201121987099
molecular interaction of tppp with prp antagonized the cytoprp-induced disruption of microtubule structures and cytotoxicity.tubulin polymerization promoting protein/p25 (tppp/p25), known as a microtubule-associated protein (map), is a brain-specific unstructured protein with a physiological function of stabilizing cellular microtubular ultrastructures. whether tppp involves in the normal functions of prp or the pathogenesis of prion disease remains unknown. here, we proposed the data that tppp formed molecular complex with prp. we also investigated its influence on the aggregation of prp and fibrillization of prp106- ...201121857997
changes induced by natural scrapie in the calretinin-immunopositive cells and fibres of the sheep cerebellar cortex.calretinin (cr)-immunopositive cells and fibres in the cerebellar cortex (vermal archicerebellum and neocerebellum) of scrapie-affected, arq/arq, rasa aragonesa breed sheep were studied in comparison with healthy, young and aged, arq/arq, rasa aragonesa animals and with manchega breed sheep. the scrapie-affected sheep showed signs of both cellular involution and hypertrophic/hyperimmunoreactive responses in all neuronal subtypes; the distribution of the neuronal subtypes in the archi- and neocer ...201122116659
prionemia and leuco-platelet associated infectivity in sheep tse models.the dynamics of the circulation and distribution of transmissible spongiform encephalopathy (tse) agents in the blood of infected individuals remain largely unknown. this clearly limits the understanding of role of blood in tse pathogenesis and the development of reliable tse blood detection assay.using two distinct sheep scrapie models and blood transfusion, this work demonstrates the occurrence of a very early and persistent prionemia. this ability to transmit disease by blood transfusion was ...201122156536
strain specific resistance to murine scrapie associated with a naturally occurring human prion protein polymorphism at residue 171.transmissible spongiform encephalopathies (tse) or prion diseases are neurodegenerative disorders associated with conversion of normal host prion protein (prp) to a misfolded, protease-resistant form (prpres). genetic variations of prion protein in humans and animals can alter susceptibility to both familial and infectious prion diseases. the n171s prp polymorphism is found mainly in humans of african descent, but its low incidence has precluded study of its possible influence on prion disease. ...201121980292
age, scrapie status, prp genotype and follicular dendritic cells in ovine ileal peyer's patches.follicular dendritic cells (fdcs) residing within ileal peyer's patches (pps) are of crucial relevance for sheep scrapie early pathogenesis and subsequent scrapie prion neuroinvasion. in this study, ileal pp follicles were significantly more numerous in lambs than in adult sarda breed sheep, with significant differences being also found in lymphoid follicle area, perimeter and fdc density. furthermore, prpd deposition within ileal pps and host's prp genotype did not significantly influence these ...201121962485
comparison of nanofiltration efficacy in reducing infectivity of centrifuged versus ultracentrifuged 263k scrapie-infected brain homogenates in "spiked" albumin solutions.background: the safety of plasma-derived products is of concern for possible transmission of variant creutzfeldt-jakob disease. the absence of validated screening tests requires the use of procedures to remove or inactivate prions during the manufacture of plasma-derived products to minimize the risk of transmission. these procedures need proper validation studies based on spiking human plasma or intermediate fractions of plasma fractionation with prions in a form as close as possible to that pr ...201122082124
tunneling-nanotube: a new way of cell-cell communication.tunneling-nanotubes (tnts) are a kind of cell-cell communication when cells are under stress. we hypothesize that insulted cells use tnts as a highway to transfer materials and energy to healthy cells. tnts transfer cellular compartments, such as endoplasmic reticulum (er), mitochondria, golgi and endosomes. some cytotoxic particles, such as intracellular and extracellular amyloid β (aβ), scrapie prion protein (prp(sc)) and human immunodeficiency virus (hiv)-1, are suggested to transfer with tnt ...201121980570
na+/k+-atpase is present in scrapie-associated fibrils, modulates prp misfolding in vitro and links prp function and dysfunction.transmissible spongiform encephalopathies are characterised by widespread deposition of fibrillar and/or plaque-like forms of the prion protein. these aggregated forms are produced by misfolding of the normal prion protein, prp(c), to the disease-associated form, prp(sc), through mechanisms that remain elusive but which require either direct or indirect interaction between prp(c) and prp(sc) isoforms. a wealth of evidence implicates other non-prp molecules as active participants in the misfoldin ...201122073199
Use of Murine Bioassay to Resolve Ovine Transmissible Spongiform Encephalopathy Cases Showing a Bovine Spongiform Encephalopathy Molecular Profile.Two cases of unusual transmissible spongiform encephalopathy (TSE) were diagnosed on the same farm in ARQ/ARQ PrP sheep showing attributes of both bovine spongiform encephalopathy (BSE) and scrapie. These cases, UK-1 and UK-2, were investigated further by transmissions to wild-type and ovine transgenic mice. Lesion profiles (LP) on primary isolation and subpassage, incubation period (IP) of disease, PrP(Sc) immunohistochemical (IHC) deposition pattern and Western blot profiles were used to char ...201121919992
Change in the characteristics of ferritin induces iron imbalance in prion disease affected brains.Prion disease associated neurotoxicity is mainly attributed to PrP-scrapie (PrP(Sc)), the disease associated isoform of a normal protein, the prion protein (PrP(C)). Participation of other proteins and processes is suspected, but their identity and contribution to the pathogenic process is unclear. Emerging evidence implicates imbalance of brain iron homeostasis as a significant cause of prion disease-associated neurotoxicity. The underlying cause of this change, however, remains unclear. We dem ...201122182691
Hypoxia-inducible factor-1 alpha regulates prion protein expression to protect against neuron cell damage.The human prion protein fragment, PrP (106-126), may contain a majority of the pathological features associated with the infectious scrapie isoform of PrP, known as PrP(Sc). Based on our previous findings that hypoxia protects neuronal cells from PrP (106-126)-induced apoptosis and increases cellular prion protein (PrP(C)) expression, we hypothesized that hypoxia-related genes, including hypoxia-inducible factor-1 alpha (HIF-1a), may regulate PrP(C) expression and that these genes may be involve ...201122036844
Proteinase K-resistant material in ARR/VRQ sheep brain affected with classical scrapie is composed mainly of VRQ prion protein.Classical scrapie is a prion disease in sheep and goats. In sheep, susceptibility to disease is genetically influenced by single amino acid substitutions. Genetic breeding programs aimed at enrichment of arginine-171 (171R) prion protein (PrP), the so-called ARR allele, in the sheep population have been demonstrated to be effective in reducing the occurrence of classical scrapie in the field. Understanding the molecular basis for this reduced prevalence would serve the assessment of ARR adaptati ...201121917981
A suitable duplex PCR for ovine embryo sex and genotype of PrnP gene determination for MOET-based selection programmes.The objective of this study was to test the suitability of a duplex PCR assay for sex and scrapie resistance genotype determination in fresh embryos. Duplex PCR amplified a repetitive and specific fragment of Y chromosome, used for sex diagnosis, and a PrnP fragment. PrnP codons 134 and 156, and codon 171 were genotyped by restriction fragment length polymorphisms and allele-specific PCR, respectively, after re-amplification of PrnP fragment. The specificity of the method was first assessed by t ...201121851426
a naturally occurring c-terminal fragment of the prion protein (prp) delays disease and acts as a dominant-negative inhibitor of prpsc formation.the cellular prion protein (prp(c)) undergoes constitutive proteolytic cleavage between residues 111/112 to yield a soluble n-terminal fragment (n1) and a membrane-anchored c-terminal fragment (c1). the c1 fragment represents the major proteolytic fragment of prp(c) in brain and several cell types. to explore the role of c1 in prion disease, we generated tg(c1) transgenic mice expressing this fragment (prp(δ23-111)) in the presence and absence of endogenous prp. in contrast to several other n-te ...201122025612
molecular typing of protease-resistant prion protein in transmissible spongiform encephalopathies of small ruminants, france, 2002-2009.the agent that causes bovine spongiform encephalopathy (bse) may be infecting small ruminants, which could have serious implications for human health. to distinguish bse from scrapie and to examine the molecular characteristics of the protease-resistant prion protein (prp(res)), we used a specifically designed western blot method to test isolates from 648 sheep and 53 goats. during 2002-2009, classical non-nor98 transmissible spongiform encephalopathy had been confirmed among ≈1.7 million small ...201121192855
understanding the neurospecificity of prion protein signaling.the cellular prion protein prp(c) is the normal counterpart of the scrapie prion protein prp(sc), the main component of the infectious agent of transmissible spongiform encephalopathies (tses). it is a ubiquitous cell-surface glycoprotein, abundantly expressed in neurons, which constitute the targets of tse pathogenesis. the presence of prp(c) at the surface of neurons is an absolute requirement for the development of prion diseases and corruption of prp(c) function(s) within an infectious conte ...201121196165
biological properties of the prp-like shadoo protein.the sprn gene encodes the shadoo glycoprotein (sho), a central nervous system-expressed member of the prion protein superfamily. sho has similarity to two features within prpc's natively unstructured n-terminus, a hydrophobic domain and tandem repeats with positively charged residues. indeed, scrutiny of sho's biochemical properties in uninfected cells has revealed overlaps with the properties of prpc, these including shared protein binding partners. sprn is conserved in mammals, as is the prion ...201121196244
spiroplasma found in the eyes of scrapie affected sheep.scrapie, a transmissible spongiform encephalopathy (tse) occurring naturally in sheep, characteristically shows a severe retinopathy that is well developed in the terminal phases of the disease. in this study, we set out to demonstrate similar retinal changes in our ruminant spiroplasmosis tse model.201121199275
demographic characteristics of scrapie-affected holdings identified by active and passive surveillance schemes in great britain: 2002-2005.several surveillance techniques have been used to quantify the prevalence of both classical and atypical scrapie in british sheep, namely the recording of clinical suspects (rc) and the testing of animals slaughtered at abattoir (as) or reported as fallen stock (fs). any estimate of prevalence based on a particular source is likely to have been affected by demographic differences in the populations sampled. in this study, the demographic characteristics of scrapie-affected holdings detected by e ...201120056463
gene expression analysis in distinct regions of the central nervous system during the development of ssbp/1 sheep scrapie.rodent scrapie models have been exploited to define the molecular basis for the progression of neuropathological changes in tse diseases. we aim to assess whether cns gene expression changes consistently observed in mouse models are of generic relevance, for example to natural tse diseases, or are tse strain, host species or brain region specific. six genes, representing distinct physiological pathways and showing consistent changes in expression levels with disease progression in murine scrapie ...201120576367
cellular and sub-cellular pathology of animal prion diseases: relationship between morphological changes, accumulation of abnormal prion protein and clinical disease.the transmissible spongiform encephalopathies (tses) or prion diseases of animals are characterised by cns spongiform change, gliosis and the accumulation of disease-associated forms of prion protein (prp(d)). particularly in ruminant prion diseases, a wide range of morphological types of prp(d) depositions are found in association with neurons and glia. when light microscopic patterns of prp(d) accumulations are correlated with sub-cellular structure, intracellular prp(d) co-localises with lyso ...201120532540
glypican-1 facilitates prion conversion in lipid rafts.the conformational conversion of the cellular prion protein (prp(c)) to the infectious form (prp(sc)) is the critical step in the pathogenesis of prion diseases such as creutzfeldt-jakob disease in humans and scrapie in sheep. cholesterol-rich lipid rafts play a key role in the conversion of prp(c) to prp(sc) and other cellular components have been identified as important cofactors to trigger, enhance, or accelerate prion formation. amongst these heparan sulphate proteoglycans (hspgs) and their ...201120681952
an assessment of the efficiency of prpsc detection in rectal mucosa and third-eyelid biopsies from animals infected with scrapie.in classical scrapie, detection of prpsc on lymphoreticular system is used for the in vivo and post mortem diagnosis of the disease. however, the sensitivity of this methodology is not well characterised because the magnitude and duration of lymphoid tissue involvement can vary considerably. the aim of the present study was to evaluate the efficiency of detecting prpsc in rectal mucosa and third-eyelid biopsies. a total of 474 genetically susceptible sheep and 24 goats from three scrapie infecte ...201120685048
pruritus in familial creutzfeldt-jakob disease: a common symptom associated with central nervous system pathology.pruritus, a common feature of animal prion diseases such as scrapie, is rarely reported in humans with creutzfeldt-jakob disease (cjd), and its anatomical background is not well defined. the present study was undertaken to carry out a methodical prospective search for the prevalence of pruritus in cjd patients and investigate its anatomical substrate by mri. the study group included consecutive familial and sporadic cjd patients carrying the e200k prnp mutation followed up in a longitudinal pros ...201120725737
cytosolic prp induces apoptosis of cell by disrupting microtubule assembly.prion protein (prp) is able to bind with tubulin and to interfere with the formation of microtubule. to investigate the influence of accumulation of cytosolic prp in cytoplasm on microtubule, plasmid pcdna3.1-prp23-230 expressing human prp23-230 was introduced into hela cells. immunoprecipitation assays identified the molecular interaction between cytosolic prp and cellular tubulin. confocal microscopy showed the co-localization of the expressed cytosolic prp with tubulin in cytoplasm. immunoflu ...201120838930
expression and knockdown of cellular prion protein (prpc) in differentiating mouse embryonic stem cells.the mammalian cellular prion protein (prp(c)) is a highly conserved glycoprotein that may undergo conversion into a conformationally altered isoform (scrapie prion protein or prp(sc)), widely believed to be the pathogenic agent of transmissible spongiform encephalopathies (tses). although much is known about pathogenic prp conversion and its role in tses, the normal function of prp(c) is poorly understood. given the abundant expression of prp(c) in the developing mammalian cns and the spatial as ...201120926176
hsp70 binds to prpc in the process of prpc release via exosomes from thp-1 monocytes.prpc (cellular prion protein) is a gpi (glycophosphatidylinositol)-anchored protein present on the surface of a number of peripheral blood cells. prpc must be present for the generation and propagation of pathogenic conformer [prpsc (scrapie prion protein)], which is a conformational conversion form of prpc and has a central role in transmissible spongiform encephalopathies. it is important to determine the transportation mechanism of normal prpc between cells. exosomes are membrane vesicles rel ...201120964628
polymorphism of prion protein gene in sheep of inner mongolian, china.susceptibility to natural scrapie in sheep is associated with polymorphisms at codons 136, 154 and 171 of the prion protein (prp) gene. to assess the risk of scrapie in sheep raised in china, dna from 30 sheep of two breeds was isolated, amplified and sequenced for the prp gene. the ovine prp gene was found to be highly homogenous. the genotype associated with high susceptibility to scrapie (vrq) was absent, whereas that associated with the resistance (arr) was present in 6.7% of sheep examined. ...201121063762
a partially folded state of ovalbumin at low ph tends to aggregate.at ph 2, ovalbumin retains native-like secondary structure as seen by far-uv cd and ftir, but lacks well-defined tertiary structure as seen by the fluorescence and near-uv cd spectra. addition of 20 mm trifluoroacetic acid (tfa) or 30 mm trichloroacetic acid (tca) on acid-induced state results in protein aggregation. this aggregated state possesses extensive β-sheet structure as revealed by far-uv cd and ftir spectroscopy. furthermore, the aggregates exhibit decreased ans fluorescence and increa ...201120703954
alimentary prion infections: touchdown in the intestine.neurodegenerative diseases are caused by proteinaceous aggregates, usually consisting of misfolded proteins which are often typified by a high proportion of β-sheets, which accumulate in the central nervous system. these diseases, including morbus alzheimer, parkinson disease and transmissible spongiform encephalopathies (tses)--also termed prion disorders--afflict a substantial proportion of the human population and as such the etiology and pathogenesis of these diseases has been the focus of m ...201121150306
structure-activity relationship refinement and further assessment of indole-3-glyoxylamides as a lead series against prion disease.structure-activity relationships within the indole-3-glyoxylamide series of antiprion agents have been explored further, resulting in discovery of several new compounds demonstrating excellent activity in a cell line model of prion disease (ec₅₀ <10 nm). after examining a range of substituents at the para-position of the n-phenylglyoxylamide moiety, five-membered heterocycles containing at least two heteroatoms were found to be optimal for the antiprion effect. a number of modifications were mad ...201121154498
extraneural manifestations of prion infection in gpi-anchorless transgenic mice.earlier studies indicated that transgenic (tg) mice engineered to express prion protein (prp) lacking the glycophosphatidylinositol (gpi⁻/⁻) membrane anchor formed abnormal proteinase-resistant prion (prpsc) amyloid deposits in their brains and hearts when infected with the rml strain of murine scrapie. in contrast, rml scrapie infection of normal mice with a gpi-anchored prp did not deposit amyloid with prpsc in the brain or the heart. here we report that scrapie-infected gpi⁻/⁻ prp tg mice als ...201121227476
glycosylphosphatidylinositol anchor-dependent stimulation pathway required for generation of baculovirus-derived recombinant scrapie prion protein.the pathogenic isoform (prp(sc)) of the host-encoded cellular prion protein (prp(c)) is considered to be an infectious agent of transmissible spongiform encephalopathy (tse). the detailed mechanism by which the prp(sc) seed catalyzes the structural conversion of endogenous prp(c) into nascent prp(sc) in vivo still remains unclear. recent studies reveal that bacterially derived recombinant prp (recprp) can be used as a substrate for the in vitro generation of protease-resistant recprp (recprp(res ...201121228241
comparison of brain prpd distribution in ovine bse and scrapie.scrapie and bovine spongiform encephalopathy (bse) are both prion diseases affecting ruminants, and these diseases do not share the same public health concerns. surveillance of the bse agent in small ruminants has been a great challenge, and the recent identification of diverse prion diseases in ruminants has led to the development of new methods for strain typing. in our study, using immunohistochemistry (ihc), we assessed the distribution of prp(d) in the brains of 2 experimentally bse-infecte ...201121245284
aerosols transmit prions to immunocompetent and immunodeficient mice.prions, the agents causing transmissible spongiform encephalopathies, colonize the brain of hosts after oral, parenteral, intralingual, or even transdermal uptake. however, prions are not generally considered to be airborne. here we report that inbred and crossbred wild-type mice, as well as tga20 transgenic mice overexpressing prp(c), efficiently develop scrapie upon exposure to aerosolized prions. nse-prp transgenic mice, which express prp(c) selectively in neurons, were also susceptible to ai ...201121249178
comparative performance of three tse rapid tests for surveillance in healthy sheep affected by scrapie.rapid tests specific for sheep and goats became part of european union-wide active scrapie surveillance in 2006. performance of three approved tse rapid tests for the detection of sheep infected with scrapie in field cases in the pre-clinical stage of the disease was compared. the medulla oblongata of 969 asymptomatic sheep of various genotype and breed aged over 18 months from 23 italian flocks affected with scrapie, were tested by the bio-rad tesee sheep/goat (a), the idexx herdchek bse-scrapi ...201121256871
emergence of multiple prion strains from single isolates of ovine scrapie.the infectious agent associated with prion diseases such as ovine scrapie shows strain diversity. ovine prion strains have typically been identified by their transmission properties in wild-type mice. however, strain typing of ovine scrapie isolates in wild-type mice may not reveal properties of the infectious prion agent as they exist in the original host. this could be circumvented if ovine scrapie isolates are passaged in ovine prion protein (prp)-transgenic mice. this study used incubation t ...201121270287
fundamentals of prions and their inactivation (review).prion is an infectious particle composed of an abnormal isoform of the prion protein (prpsc) and causes prion diseases such as bovine spongiform encephalopathy (bse), creutzfeldt-jakob disease (cjd) and scrapie. host cells express cellular prion protein (prpc), which plays roles in normal functions such as anti-oxidative stress. prpsc is derived from prpc and produced by conformational conversion. prion is notorious as a resistant pathogen, being difficult to inactivate with conventional sterili ...201121271212
sparse prp(sc) accumulation in the placentas of goats with naturally acquired scrapie.domestic goats (capra hircus) are a natural and experimental host of scrapie and bovine spongiform encephalopathy, the transmissible spongiform encephalopathies (tse) of sheep and cattle. goats are also susceptible to experimental infection with the agents of tses of deer and elk (chronic wasting disease) and humans (creutzfeldt jakob disease). distribution of prpsc, the abnormal prion protein, is similar in the tissues of scrapie-infected sheep and goats but no data are available on the potenti ...201121284878
utility of mass spectrometry in the diagnosis of prion diseases.we developed a sensitive mass spectrometry-based method of quantitating the prions present in a variety of mammalian species. calibration curves relating the area ratios of the integrated mrm signals from selected analyte peptides and their oxidized analogues to their homologous stable isotope labeled internal standards were prepared. the limit of detection (lod) and limit of quantitation (loq) for the synthetic peptides from human, sheep, deer, cow, and mouse prp were determined to be below 100 ...201121288014
transmission of classical scrapie to wild-type mice: the influence of the ovine prp sequence on lesion profiles.susceptibility of sheep to classical scrapie is determined by polymorphisms in the coding region of the prion protein gene (prnp), mainly at codons 136, 154 and 171. it has recently been shown that lesion profiles from classical field scrapie isolates that transmitted to riii mice can be classified into different groups. there was also strong, but not absolute, association between the different groups and codon 136. here, we examine the hypothesis that additional polymorphisms in the open readin ...201121293966
in situ photodegradation of incorporated polyanion does not alter prion infectivity.single-stranded polyanions =40 bases in length facilitate the formation of hamster scrapie prions in vitro, and polyanions co-localize with prp(sc) aggregates in vivo. to test the hypothesis that intact polyanionic molecules might serve as a structural backbone essential for maintaining the infectious conformation(s) of prp(sc), we produced synthetic prions using a photocleavable, 100-base oligonucleotide (pc-oligo). in serial protein misfolding cyclic amplification (spmca) reactions using purif ...201121304885
breeding with resistant rams leads to rapid control of classical scrapie in affected sheep flocks.abstract: susceptibility to scrapie, a transmissible spongiform encephalopathy in sheep, is modulated by the genetic make-up of the sheep. scrapie control policies, based on selecting animals of resistant genotype for breeding, have recently been adopted by the netherlands and other european countries. here we assess the effectiveness of a breeding programme based on selecting rams of resistant genotype to obtain outbreak control in classical scrapie-affected sheep flocks under field conditions. ...201121314971
changes in hsp gene and protein expression in natural scrapie with brain damage.abstract: heat shock proteins (hsp) perform cytoprotective functions such as apoptosis regulation and inflammatory response control. these proteins can also be secreted to the extracellular medium, acting as inflammatory mediators, and their chaperone activity permits correct folding of proteins and avoids the aggregation of anomalous isoforms. several studies have proposed the implication of hsp in prion diseases. we analysed the gene expression and protein distribution of different members of ...201121314976
expression patterns of prion protein gene in differential genotypes sheep: quantification using molecular beacon real-time rt-pcr.determination of the transcription level of cellular prion protein (prp(c)) is essential for understanding its role in organisms and revealing mechanism of susceptibility and resistance to scrapie. however, the expression of prion protein (prp) mrna in sheep has not been quantified in great detail in digestive tract which is important during scrapie spread through oral route. herein, we report on measurement of sheep prp mrna using absolute quantitative real-time rt-pcr. total rna was isolated f ...201121318242
effects of polymorphisms in ovine and caprine prion protein alleles on cell-free conversion.abstract: in sheep polymorphisms of the prion gene (prnp) at the codons 136, 154 and 171 strongly influence the susceptibility to scrapie and bovine spongiform encephalopathy (bse) infections. in goats a number of other gene polymorphisms were found which are suspected to trigger similar effects. however, no strong correlation between polymorphisms and tse susceptibility in goats has yet been obtained from epidemiological studies and only a low number of experimental challenge data are available ...201121324112
the impact of the genotype on the prevalence of classical scrapie at population level.abstract: total number and genotypes of animals in holdings selected for the genotype & cull option in the compulsory scrapie flock scheme (csfs) in great britain were extracted from the national scrapie plan data warehouse. the association between various genotype-related measures and scrapie prevalence infection was tested using zero-inflated negative binomial models with the counts of positive cases as dependent variable, and country, number of flocks in the scheme, flock size, surveillance s ...201121324113
prpsc spreading patterns in the brain of sheep linked to different prion types.abstract: scrapie in sheep and goats has been known for more than 250 years and belongs nowadays to the so-called prion diseases that also include e.g. bovine spongiform encephalopathy in cattle (bse) and creutzfeldt-jakob disease in humans. according to the prion hypothesis, the pathological isoform (prpsc) of the cellular prion protein (prpc) comprises the essential, if not exclusive, component of the transmissible agent. currently, two types of scrapie disease are known - classical and atypic ...201121324114
normal modes of prion proteins: from native to infectious particle.prion proteins (prp) are the infectious agent in transmissible spongiform encephalopathies (i.e., mad cow disease). to be infectious, prion proteins must undergo a conformational change involving a decrease in a-helical content along with an increase in ß-strand content. this conformational change was evaluated by means of elastic normal modes. elastic normal modes show a diminution of two a-helices by one and two residues, as well as an extension of two ß-strands by three residues each, which c ...201121338080
subcellular localization of peptidylarginine deiminase 2 and citrullinated proteins in brains of scrapie-infected mice: nuclear localization of pad2 and membrane fraction-enriched citrullinated proteins.peptidylarginine deiminase (pad) and citrullinated proteins have emerged as key molecules in various human diseases, but detailed subcellular localizations of pad2 and citrullinated proteins are poorly mapped in brain under normal and pathologic conditions. we performed subcellular fractionation and electron microscopic analysis using brains of normal and scrapie-infected mice. peptidylarginine deiminase 2 was abundantly present in cytosol and weakly in microsomal and mitochondrial fractions and ...201121343880
prion diseases of yeast: amyloid structure and biology.prion "variants" or "strains" are prions with the identical protein sequence, but different characteristics of the prion infection: e.g. different incubation periods for scrapie strains or different phenotype intensities for yeast prion variants. we have shown that infectious amyloids of the yeast prions [psi+], [ure3] and [pin+] each have an in-register parallel ß-sheet architecture. moreover, we have pointed out that this amyloid architecture can explain how one protein can faithfully transmit ...201121345375
biological effects and use of prpsc- and prp-specific antibodies generated by immunization with purified full-length native mouse prions.the prion agent is the infectious particle causing spongiform encephalopathies in animals and humans and is thought to consist of an altered conformation (prp(sc)) of the normal and ubiquitous prion protein prp(c). the interaction of the prion agent with the immune system, particularly the humoral immune response, has remained unresolved. here we investigated the immunogenicity of full-length native and infectious prions, as well as the specific biological effects of the resulting monoclonal ant ...201121345946
atypical/nor98 scrapie infectivity in sheep peripheral tissues.atypical/nor98 scrapie was first identified in 1998 in norway. it is now considered as a worldwide disease of small ruminants and currently represents a significant part of the detected transmissible spongiform encephalopathies (tse) cases in europe. atypical/nor98 scrapie cases were reported in arr/arr sheep, which are highly resistant to bse and other small ruminants tse agents. the biology and pathogenesis of the atypical/nor98 scrapie agent in its natural host is still poorly understood. how ...201121347349
highly efficient protein misfolding cyclic amplification.protein misfolding cyclic amplification (pmca) provides faithful replication of mammalian prions in vitro and has numerous applications in prion research. however, the low efficiency of conversion of prp(c) into prp(sc) in pmca limits the applicability of pmca for many uses including structural studies of infectious prions. it also implies that only a small sub-fraction of prp(c) may be available for conversion. here we show that the yield, rate, and robustness of prion conversion and the sensit ...201121347353
prion propagation and toxicity in vivo occur in two distinct mechanistic phases.mammalian prions cause fatal neurodegenerative conditions including creutzfeldt-jakob disease in humans and scrapie and bovine spongiform encephalopathy in animals. prion infections are typically associated with remarkably prolonged but highly consistent incubation periods followed by a rapid clinical phase. the relationship between prion propagation, generation of neurotoxic species and clinical onset has remained obscure. prion incubation periods in experimental animals are known to vary inver ...201121350487
features of follicular dendritic cells in ovine pharyngeal tonsil: an in vivo and in vitro study in the context of scrapie pathogenesis.although the alimentary tract has been suggested as the most likely portal of entry in natural scrapie, a growing amount of data indicates that the respiratory system and more specifically the pharyngeal tonsils serve as a natural portal of entry for scrapie. this study describes for the first time the broad cell populations in the lymphoid compartment of pharyngeal tonsils and more specifically inside the lymphoid follicles where the scrapie agent accumulates during the period of latency. folli ...201121353313
sc237 hamster prpsc and sc237-derived mouse prpsc generated by interspecies in vitro amplification exhibit distinct pathological and biochemical properties in tga20 transgenic mice.prions are the infectious agents responsible for transmissible spongiform encephalopathy, and are primarily composed of the pathogenic form (prp(sc)) of the host-encoded prion protein (prp(c)). recent studies have revealed that protein misfolding cyclic amplification (pmca), a highly sensitive method for prp(sc) detection, can overcome the species barrier in several xenogeneic combinations of prp(sc) seed and prp(c) substrate. although these findings provide valuable insight into the origin and ...201121362027
survival of infectious prions in class b biosolids.this study developed a method for extracting infectious prions from class b biosolids and subsequently evaluated the survival of infectious prions under the influence of mesophilic (37-¦c) and thermophilic (60-¦c) temperatures in class b biosolids. unlike other studies, this study utilized a scrapie cell assay to determine infectivity and quantity of infectious prions. the best method for extraction was exposing the biosolids to 4 m urea at 80-¦c for 10 minutes followed by a membrane centrifugat ...201121391030
[active surveillance for scrapie in the netherlands: effect of a breeding programme on the prevalence of scrapie in sheep (2002-2010)?].the susceptibility of sheep to scrapie is modulated by the prion protein (prp) genotype of the animal. an ambitious voluntary scrapie control programme was started in the netherlands in 1998, based on selection of rams with thearr/arr genotype for breeding. this programme was followed by an obligatory programme in 2004; the programme has been voluntary since 2007. we monitored the prevalence of prp genotype frequencies and the prevalence of scrapie in the dutch sheep population between 2002 and ...201121404540
a study on the analytical sensitivity of 6 bse tests used by the canadian bse reference laboratory.bovine spongiform encephalopathy (bse) surveillance programs have been employed in numerous countries to monitor bse prevalence and to protect animal and human health. since 1999, the european commission (ec) authorized the evaluation and approval of 20 molecular based tests for the rapid detection of the pathological prion protein (prp(sc)) in bse infection. the diagnostic sensitivity, convenience, and speed of these tests have made molecular diagnostics the preferred method for bse surveillanc ...201121412419
hybrid lipoic acid derivatives to attack prion disease on multiple fronts. 201121412985
synthesis, structural characterization, formation constants and in vitro cytotoxicity of phenanthroline and imidazolidine-2-thione copper(ii) complexes.the synthesis, crystal structures, physicochemical properties and complex formation constants of [cu(phen)(2)(l)](clo(4))(2) complexes, where phen is 1,10-ortho-phenanthroline and l is a series of substituted imidazolidine-2-thione, have been studied. single crystal x-ray diffraction revealed a distorted trigonal-bipyramidal geometry for all the molecules. the complex formation constants were determined in nonaqueous media by spectrophotometric measurements. testing copper(ii) complexes in mouse ...201121421120
replication efficiency of soil-bound prions varies with soil type.prion sorption to soil is thought to play an important role in the transmission of scrapie and chronic wasting disease (cwd) via the environment. sorption of prp to soil and soil minerals is influenced by the strain and species of prp(sc) and by soil characteristics. however, the ability of soil-bound prions to convert prp(c) to prp(sc) under these wide-ranging conditions remains poorly understood. we developed a semiquantitative protein misfolding cyclic amplification (pmca) protocol to evaluat ...201121430062
blocking of fcr suppresses the intestinal invasion of scrapie agents.prion diseases are a family of neurodegenerative zoonotic foodborne disorders. although prions can be transmitted orally, the mechanism by which prions are incorporated into the intestine remains unclear. our previous studies have shown that an abnormal isoform of prion protein (prp(sc)), which is the main component of prions, was efficiently incorporated into the intestine in suckling mice but not in weaned mice. furthermore, suckling scid mice lacking maternal antibodies showed decreased uptak ...201121437246
the cellular prion protein mediates neurotoxic signalling of ß-sheet-rich conformers independent of prion replication.formation of aberrant protein conformers is a common pathological denominator of different neurodegenerative disorders, such as alzheimer's disease or prion diseases. moreover, increasing evidence indicates that soluble oligomers are associated with early pathological alterations and that oligomeric assemblies of different disease-associated proteins may share common structural features. previous studies revealed that toxic effects of the scrapie prion protein (prp(sc)), a ß-sheet-rich isoform o ...201121441896
deduction of the evaluation limit and termination timing of multi-round protein misfolding cyclic amplification from a titration curve.in this study, the efficacy of disinfectants in reducing the partially protease-resistant isoform of prion protein was evaluated by a multi-round protein misfolding cyclic amplification (pmca) technique. hamster brains infected with scrapie-derived strain 263k were homogenized, treated under inactivating or mock conditions, and subjected to multi-round pmca. four sets of serial 10-fold dilutions of mock-treated samples were analyzed. although considerable variability was observed in the signal p ...201121443616
distinct proteinase k-resistant prion protein fragment in goats with no signs of disease in a classical scrapie outbreak.considerable efforts have been directed toward the identification of small-ruminant prion diseases, i.e., classical and atypical scrapie as well as bovine spongiform encephalopathy (bse). here we report the in-depth molecular analysis of the proteinase k-resistant prion protein core fragment (prp(res)) in a highly scrapie-affected goat flock in greece. the prp(res) profile by western immunoblotting in most animals was that of classical scrapie in sheep. however, in a series of clinically healthy ...201121450953
overexpression of shadoo protein in transgenic mice does not impact the pathogenesis of scrapie.shadoo is a glycoprotein expressed in the adult brain that is an interacting protein of prion protein; however, its function remains to be determined. to elucidate its role in prion pathogenesis, we generated transgenic mice overexpressing wild-type (wt) shadoo driven by the murine prp promoter. expression of the murine sprn transgene significantly increased brain shadoo protein levels in all three mouse lines generated. following infection with mouse-adapted scrapie strain 22l, all transgenic m ...201121458534
investigation of the effects of experimental autolysis on the detection of abnormal prion protein in lymphoid and central nervous system tissues from elk and sheep using the western blotting method.tissues unsuitable for standard immunohistochemical and histopathological examinations for chronic wasting disease (cwd) in cervids and for scrapie in sheep are frequently submitted for testing. this study investigated the effects of experimental autolysis on the detection of abnormal prion protein (prpsc) in lymphoid and central nervous system (cns) tissues from elk and sheep. the prpsc was detected using a western blotting (wb) test following prpsc enrichment using sodium phosphotungstic acid ...201121461199
molecular dynamics studies on the structural stability of wild-type dog prion protein.prion diseases such as creutzfeldt-jakob disease, variant creutzfeldt-jakob diseases, gerstmann-sträussler-scheinker syndrome, fatal familial insomnia, kuru in humans, scrapie in sheep, bovine spongiform encephalopathy (or 'mad-cow' disease) and chronic wasting disease in cattle are invariably fatal and highly infectious neurodegenerative diseases affecting humans and animals. however, by now there have not been some effective therapeutic approaches to treat all these prion diseases. in 2008, ca ...201121469747
Refresh
firstprev
12345678910...
nextlast
Displaying items 101 - 200 of 4534