Publications

[the ola major histocompatibility complex of sheep. genetic frequencies compared in prélpe sheep with and without scrapie].	the ola genic frequencies were studied in both normal "préalpe" sheep and those affected with scrapie. in the non-affected sheep of contaminated flocks, frequencies were generally decreased, compared with frequencies of the same factors in sick sheep or in non-infected controls. three ola-a genes significantly decreased; at this locus, results in "préalpe" and "ile-de-france" sheep were inversed. this observation excludes ola genes being involved in pathogeny or resistance to the disease, but su ...	1984	6430472
occurrence of ovine scrapie in japan: clinical and histological findings in mice inoculated with brain homogenates of an affected sheep.		1984	6441054
the reticuloendothelial system in scrapie pathogenesis.	a single injection of 1 mg dextran sulphate 500 per mouse considerably prolonged incubation times and produced survivors, even when given 3 days after intravenous or intraperitoneal scrapie infection. since this compound could be detected in mononuclear phagocytes of spleen and lymph nodes for up to 7 months, it is suggested that it impairs a particular step in the infectious process in these cells of the lymphoreticular system. blockage of the reticuloendothelial system by trypan blue and silic ...	1984	6198455
characterization of lipids in membrane vesicles from scrapie-infected hamster brain.	the lipid compositions of membrane vesicles from scrapie-infected and uninfected hamster brains were examined before and after detergent extraction. no differences were observed in polar lipids, glycolipids, gangliosides or neutral lipids examined by thin-layer chromatography. analysis of detergent-extracted cscl gradient fractions with high scrapie infectivity failed to reveal any glycerolphosphatides, although neutral lipids were demonstrated. the major neutral lipid associated with detergent- ...	1985	3920350
[prion antibodies and structure analysis clarify questions about atypical viruses. prion structure under the electron microscope].		1985	3920456
retinal degeneration in experimental scrapie after intraperitoneal or subcutaneous inoculation of hamsters.	hamsters injected intraperitoneally or subcutaneously with the scrapie agent developed photoreceptor degeneration. the degree of degeneration did not correlate well with infectivity titers of retinal tissue or stage of clinical encephalopathy, and was not as great as seen in intracerebrally injected animals. we conclude that retinal degeneration is universal in hamsters experimentally inoculated with the scrapie agent regardless of the route of inoculation.	1985	3921398
"slow infections"--a challenge to traditional concepts.		1985	3934107
specific proteins associated with creutzfeldt-jakob disease and scrapie share antigenic and carbohydrate determinants.	small amounts of brain tissue (2 g) infected with creutzfeldt-jakob disease (cjd) can be fractionated by using a simple 1-day method that includes lysis with n-lauroylsarcosine. unique fibrils have been identified previously in scrapie- and cjd-infected tissue. these fibrils were abundant in final fractions. preparations from human cjd autopsy material and from experimental hamster and guinea pig cjd all displayed readily identifiable fibrils that were not seen in control preparations. thus, the ...	1985	2408277
characterization of nucleic acids in membrane vesicles from scrapie-infected hamster brain.	this study reports the partial characterization of nucleic acids present in gradient fractions enriched for large membrane vesicles from scrapie-infected and uninfected hamster brains. labeling of phenol-extracted nucleic acids at the 3' or 5' ends revealed abundant amounts of low-molecular-weight rna and little or no dna. these nucleic acids survived nuclease treatment of membrane vesicles but were sensitive to rnase after phenol extraction. analysis of 5'-end-labeled nucleic acids by one- and ...	1985	2409296
isonicotinic hydrazide causes seizures in scrapie-infected hamsters with shorter latency than in control animals: a possible gabaergic defect.	isonicotinic hydrazide, a drug that decreases the level of gaba, when injected subcutaneously in control and scrapie-infected hamsters induced tonic-clonic seizures in scrapie hamsters significantly earlier (p less than 0.0001) than in control animals. this suggests depression of the gabaergic system in scrapie-infected hamsters. to determine whether this lesion is pre or postsynaptic we measured the level of gaba, glutamate, cgmp and camp and the gaba-benzodiazepine receptor complex.	1985	2857587
evidence that transmissible mink encephalopathy agent is biologically inactive in mice.	transmissible mink encephalopathy (tme) is probably a form of the sheep disease, scrapie, introduced by accidentally feeding mink with scrapie-infected sheep tissues. although no successful transmissions of tme to mice have been achieved previous work has involved various limitations. to maximize the possibility of transmission, 176 mice, representing 14 different genotypes mostly not previously tested with tme, were injected with tme-infected mink brain from three sources with different histori ...	1986	2940470
[light and electron microscopic observations of sheep scrapie].	two suffolk sheep diagnosed as scrapie clinically and epidemiologically were investigated light and electron microscopically. they were female and four years four months of age. spongiform lesions were found in the gray and white matter of midbrain, pons, medulla oblongata, spinal cord and the cerebellar white matter as well as the cerebral gray and white matter. ultrastructurally, the spongiform lesions were shown to be caused by vacuolation in neuronal perikarya, vacuolation and/or swelling of ...	1986	3768187
immunostaining of scrapie cerebral amyloid plaques with antisera raised to scrapie-associated fibrils (saf).	brain sections from 16 different mouse scrapie models were immunostained with antisera to scrapie-associated fibrils (saf) from three experimental scrapie sources (hamster 263k, mouse me7 and mouse 22l). these models involved seven strains of scrapie injected intracerebrally or intraperitoneally into a range of inbred mouse strains, producing a wide variety of neuropathological changes. the only brain structures which were positively immunostained were amyloid plaque cores in those models in whi ...	1988	3221978
bovine spongiform encephalopathy: time to take scrapie seriously.		1988	3394240
polyclonal increase in certain igg subclasses in mice persistently infected with the 87v strain of scrapie.	eight different combinations of seven strains of scrapie agent and the three known sinc genotypes of mice were screened for changes in the concentration of igg in serum. a single radial immunodiffusion assay was used to measure igg throughout the incubation period which in different models ranged from an average of 125 days to longer than the maximum observation period of about 600 days. the only major changes occurred with the 87v strain of scrapie injected intracerebrally (i.c.) or intraperito ...	1989	2507597
bovine spongiform encephalopathy: a scrapie-like disease of british cattle.	scrapie is a cns degenerative infection of sheep and goats, which is invariably fatal after incubation periods of several months to years. related disorders are found naturally in man and other species. there is a impairment of protein catabolism in scrapie and related diseases which leads to the accumulation of sparingly-soluble protein deposits in brain. these protein aggregates may share with the amyloid of alzheimer's disease (ad) some common stage in the biochemical pathways of their format ...	1989	2574875
classic genetics of scrapie.	many years ago, observations of natural scrapie revealed differences in clinical manifestations and in the areas of the brain that showed the most intense histopathological changes. in experimental work with scrapie in mice two fundamental points were established in early studies: (1) a mouse gene, termed sinc for scrapie incubation, affects the length of the incubation period. (2) in a single strain of mice, incubation periods of different "strains" of scrapie can differ by as much as 3-4 fold, ...	1989	2690115
scrapie and the sheep mhc: claims of linkage refuted.		1989	2731967
scrapie prion proteins accumulate in the cytoplasm of persistently infected cultured cells.	the cellular prion protein (prpc) is a sialoglycoprotein anchored to the external surface of cells by a glycosyl phosphatidylinositol moiety. during scrapie, an abnormal prp isoform designated prpsc accumulates, and much evidence argues that it is a major and necessary component of the infectious prion. based on the resistance of native prpsc to proteolysis and to digestion with phosphatidylinositol-specific phospholipase c as well as the enhancement of prpsc immunoreactivity after denaturation, ...	1990	1693623
experimental transmission of scrapie to cattle.		1990	1971338
detection of bovine spongiform encephalopathy in the united kingdom.		1990	1971813
structure of scrapie-associated protein and its relation to infectivity.		1990	1971816
[the biology of prions, a response to the enigma of spongiform encephalopathies of sheep and humans].	prions are small proteinaceous infectious particles without nucleic acids. the prion protein arise from a cellular protein by a post-transduction event and constitute amyloid deposits. prions are the agent of animal and human spongiform encephalopathies which evolve on simultaneous infectious and genetic dependence in the absence of a detectable immune response.	1990	2094563
proceedings of an international roundtable on bovine spongiform encephalopathy.		1990	2189852
bovine spongiform encephalopathy--a new disease transmissable to humans?	current concerns about the cattle disease bovine spongiform encephalopathy do not appear to take cognisance of the parallel with scrapie, the similar/identical disease of sheep/goats. this has existed for 200 years, and clearly involved a longstanding consumption of meat/offal from affected animals, but apparently without consequential human disease. a summary is given of the characteristics of the human and animal spongiform encephalopathy diseases and their causative agents. the conclusion of ...	1990	2233424
a questionnaire survey of the prevalence of scrapie in sheep in britain.	an anonymous, self-administered questionnaire has been used in two independent surveys to try to determine the prevalence of scrapie in the national sheep flock. the disease was recorded in 35 counties in england and wales. about a third (26.5 and 37.3 percent) of respondents owning 100 or more sheep indicated that they had seen sheep with scrapie in their flocks. the incidences of clinical cases recorded in affected flocks in the two surveys were 0.5 and 1.1 cases/100 ewes/year. at present ther ...	1990	2260251
tainted feed, mad cows. could a british cattle disease infect u.s. herds?		1990	2333492
the scrapie control program in the united states.		1990	2347767
the unexpected export?		1990	2348869
link between scrapie and bse?		1990	2366871
some problems of diagnosis of the spongiform encephalopathies in ruminants.	the difficulties of a positive diagnosis in the spongiform encephalopathies based only on epidemiological and clinical data are briefly reviewed. however, in b.s.e. as in scrapie, the epidemiology and the clinical data may frequently suggest these diseases. the main diseases which must be taken into account in the differential diagnosis of both spongiform encephalopathies are discussed and the criteria of the differential diagnosis are tabulated.	1991	1761111
genetic and environmental factors determining the development of creutzfeldt-jakob disease in libyan jews.	the cluster of creutzfeldt-jakob disease (cjd) among jews of libyan origin is one of the largest in the world. a number of hypotheses have been proposed to account for this cluster, the most prevalent but unsubstantiated hypothesis being that a transmissible agent was ingested in the form of scrapie-infected sheep brains. it has, however, been shown that a modified host protein encoded by the gene specifying the scrapie amyloid precursor is critically involved in the pathogenesis of transmissibl ...	1991	1798423
natural transmission and genetic control of susceptibility of sheep to scrapie.		1991	1810708
epidemiological and experimental studies on a new incident of transmissible mink encephalopathy.	epidemiological investigation of a new incident of transmissible mink encephalopathy (tme) in stetsonville, wisconsin, u.s.a. in 1985 revealed that the mink rancher had never fed sheep products to his mink but did feed them large amounts of products from fallen or sick dairy cattle. to investigate the possibility that this occurrence of tme may have resulted from exposure to infected cattle, two holstein bull calves were injected intracerebrally with mink brain from the stetsonville ranch. each ...	1991	1826023
diagnosis of scrapie.		1991	1859542
naturally occurring scrapie-like spongiform encephalopathy in five domestic cats.	naturally occurring transmissible spongiform encephalopathies have been recognised in sheep, man, mink, captive deer and cattle. recently a similar disease was reported in a domestic cat. this paper describes the clinical and pathological findings in five cats with similar signs, including further observations on the original case. all the cats had a progressive, neurological disease involving locomotor disturbances, abnormal behaviour and, in most cases, altered sensory responses. histopatholog ...	1991	1957458
molecular biology and pathology of scrapie and the prion diseases of humans.	scrapie and bovine spongiform encephalopathy of animals and creutzfeldt-jakob and gerstmann-sträussler-scheinker diseases of humans are transmissible and genetic neurodegenerative diseases caused by prions. infectious prion particles are composed largely, if not entirely, of an abnormal isoform of the prion protein which is encoded by a chromosomal gene. an as yet unidentified post-translational process converts the cellular prion protein into an abnormal isoform. scrapie neuropathology, incubat ...	1991	1669719
bovine spongiform encephalopathy: a neuropathological perspective.	the occurrence of bovine spongiform encephalopathy (bse), recognition that it is a new scrapie-like disease epidemic in domestic cattle in the united kingdom and concern of a remote zoonotic potential has, in four years, produced a plethora of documented information. while much of this information has been communicated outwith the scientific literature, this review attempts to summarise, from a neuropathological viewpoint, the main findings to emerge. the initial studies established the nosologi ...	1991	1688299
[prion encephalopathies].	spongiform encephalopathies, also called prion encephalopathies, are characterized, in human as well as in animals, by (1) their clinical picture which indicates strict localisation in central nervous system, (2) their histological aspect: spongiform degeneration and neuronal loss, and (3) their transmissibility in the same animal species but also from man to animal. the nature of the pathogenic agent is still debated. this agent could be one isoform of the prion protein which, probably because ...	1992	1288542
immunoreactivity to ubiquitin-protein conjugates is present early in the disease process in the brains of scrapie-infected mice.	brains from mice infected with either the 87v or the me7 strains of mouse-passaged sheep scrapie were taken at stages during the disease process and immunostained to show the localization of ubiquitin-protein conjugates. in both models, conjugates were seen as fine, dot-like structures; as coarser, granular lesions within or adjacent to neurones; and in areas surrounding plaques. the dot-like structures were visible at 28 days post-me7 infection and at 55 days in 87v-infected mice. in both model ...	1992	1334140
a specific rflp type associated with the occurrence of sheep scrapie in japan.	we have investigated restriction fragment length polymorphism (rflp) on the prp gene and the frequencies of rflp patterns in 35 healthy suffolk sheep randomly collected. according to the combinations of prp encoding dna fragments generated by restriction enzymes eco ri and hind iii, the rflp patterns were classified into six types and designated as types i to vi. the frequencies of these types were as follows: i, 8.6%; ii, 11.4%; iii, 17.6%; iv, 11.4%; v, 28.6%; and vi, 22.9%. in 10 sheep diagno ...	1992	1360795
hidden amyloidoses.	the pathogenesis as well as the genetic disposition to develop clinical symptoms in transmissible spongiform encephalopathies (e.g. creutzfeldt-jakob disease, scrapie, bovine spongiform encephalopathy) relate these diseases to classical noninfectious amyloidoses (familial amyloidotic polyneuropathy as an example) and to alzheimer's disease. this is not obvious to the nonexpert at first glance. this communication tries to elucidate this association, to reveal which immunochemical techniques have ...	1992	1364008
bovine spongiform encephalopathy (bse): a stimulus to wider research.	the severity of the epidemic of bovine spongiform encephalopathy which is currently afflicting cattle in the british isles has stimulated a considerable research effort, much of which is directed toward understanding the aetiology and pathogenesis of the bovine disease. however, a significant thrust has also been orchestrated to address more fundamental issues such as the nature of the uncharacterized causal agents of the wider range of unusual animal and human diseases which share similar chara ...	1992	1364085
molecular cloning of a mink prion protein gene.	transmissible mink encephalopathy (tme) is a rare disease which is presumably transmitted to ranch-raised mink from scrapie-infected sheep offal or bovine spongiform encephalopathy-infected cattle products. although the infectious agent of tme has not been isolated, there is circumstantial evidence that tme is caused by prions. the experimental host range of tme includes sheep, cattle, monkeys and hamsters. however, tme has never been transmitted to mice. since experiments in transgenic animals ...	1992	1383401
analysis of cerebrospinal fluid from field cases of some common ovine neurological diseases.	analysis of cerebrospinal fluid (csf) samples from normal sheep and from cases of some common neurological diseases revealed a significant increase (p less than 0.05) in the group mean csf protein concentration for meningitis, listeriosis and spinal abscess but not for scrapie, spinal injury, ovine pregnancy toxaemia or polioencephalomalacia. the csf white blood cell count (wbc) was significantly increased (p less than 0.05) in the meningitis group and in those cases of listeriosis which failed ...	1992	1551009
purification of non-infectious ganglioside preparations from scrapie-infected brain tissue.	the extraction and purification of gangliosides from brains of animals infected with the scrapie agent was evaluated by scaling-down a large-scale procedure currently used with bovine brains. inactivation experiments employed hamster brains infected with the 263 k strain of scrapie. residual infectivity was determined at different points of the procedure and in the final preparation by an in vivo animal bioassay. the efficacy of single steps, which included chemicals or physical techniques known ...	1992	1571012
scrapie: a clinical assessment.		1992	1604786
[spongiform encephalopathies with special reference to bovine spongiform encephalopathy].	in switzerland bovine spongiform encephalopathy (bse) was detected for the first time in november 1990. it is a transmissible disease of the central nervous system similar to creutzfeldt-jakob disease (cjd), gerstmann-sträussler-scheinker syndrome (gss) and kuru in man, and, in animals, scrapie in sheep and goats, chronic wasting disease (cwd) in captive mule deer and elk of north america and transmissible mink encephalopathy (tme) of farm reared mink. the infectious agent of the spongiform ence ...	1992	1615298
studies on a species-specific epitope in murine, ovine and bovine prion protein.	transmissible spongiform encephalopathies are fatal neurodegenerative disorders which are linked to abnormal isoforms of the prion protein (prp), which is expressed in different cells of various mammalian species. susceptibility to disease and reduced transmission rates upon the first passage to another species are thought to be a result of functional and biochemical differences of the prp as a consequence of amino acid sequence among species. in 1985 an epidemic of bovine spongiform encephalopa ...	1993	7687651
hungary remains free of scrapie and bovine spongiform encephalopathy (bse).	brains from 44 sheep and 43 cattle with cns clinical signs not due to rabies virus infection were collected from diagnostic institutes throughout hungary. the brains were examined for histological lesions diagnostic of scrapie/bovine spongiform encephalopathy (bse) and all were found to be negative. these findings confirm that hungary remains free of scrapie and bse.	1993	8017235
human prion diseases (spongiform encephalopathies).	prion diseases (spongiform encephalopathies) in humans are creutzfeldt-jakob disease (cjd), gerstmann-sträussler-scheinker syndrome (gss), and kuru. clinically, they are characterized by an inexorably progressing neurological illness with dementia and ataxia as the most prominent signs. the classical neuropathological changes are limited to the central nervous system and consist of spongiform degeneration, amyloid plaques, astrocytic gliosis, and nerve cell loss. the human spongiform encephalopa ...	1993	8219808
scrapie control in the united states.		1993	8236771
bovine spongiform encephalopathy.		1993	8288469
risk analysis and the importation of animals and animal products.	importation of animals or animal products cannot take place without some element of risk. risk analysis is a blend of art and science and is a tool intended to provide decision-makers with an objective, repeatable and defensible assessment of the risks posed by a particular import proposal. risk analysis comprises risk identification, risk assessment, risk management and risk communication. examples are presented of risk analysis involving anthrax in green hides, slow virus diseases and sheep em ...	1993	8312612
french autochthonous scrapied sheep without the 136val prp polymorphism.		1993	8104061
inactivation of se agents.	the transmissible agents of the spongiform encephalopathies are relatively resistant to inactivation, and accidental transmission has occurred in animals and man. rigorous chemical or physical procedures are required to achieve decontamination, and their effectiveness can only be determined by bioassay in animals. the best-defined model is scrapie in mice or hamsters, and this has been used in many of the studies to establish practical inactivation procedures. although a number of techniques had ...	1993	8137130
detection of apoptosis induced dna cleavage in scrapie-infected sheep brain.	the pathogenesis and molecular basis of nerve cell death which accompanies scrapie infections in sheep are not well understood. degeneration of neurons in culture caused by prion protein fragments has recently been reported to be consistent with mechanisms of cell death by apoptosis or programmed cell death. apoptosis activation during prion-related encephalopathies has not yet been established in vivo. we report here the detection of dna damage consistent with apoptosis in the brain cells of sh ...	1994	8138146
prp genotypes and the sip gene in cheviot sheep form the basis for scrapie strain typing in sheep.		1994	8030950
bse awareness programme in tasmania.		1994	8059517
endosome-lysosomes and neurodegeneration.	a number of the major human and animal neurodegenerative diseases, such as alzheimer's disease and sheep scrapie, are characterised by deposits of amyloid, arising through incomplete breakdown of membrane proteins. although our knowledge concerning these diseases is increasing, they remain largely untreatable. recently, attention has focussed on the mechanisms of production of different types of amyloid and the likely involvement within cells of acid compartments called endosome-lysosomes. these ...	1994	7858158
structure and polymorphism of the mouse prion protein gene.	missense mutations in the prion protein (prp) gene, overexpression of the cellular isoform of prp (prpc), and infection with prions containing the scrapie isoform of prp (prpsc) all cause neurodegenerative disease. to understand better the physiology and expression of prpc, we retrieved mouse prp gene (prn-p) yeast artificial chromosome (yac), cosmid, phage, and cdna clones. physical mapping positions prn-p approximately 300 kb from ecotropic virus integration site number 4 (evi-4), compatible w ...	1994	7912827
identification of five allelic variants of the sheep prp gene and their association with natural scrapie.	scrapie is a fatal neurodegenerative disease of sheep that belongs to the group of prion diseases found in humans and animals. the host encoded prion protein (prp) plays a central role in the disease process. in the prp genes of man, mice and sheep, polymorphisms have been found that are associated with disease susceptibility and pathogenesis. we have used denaturing gradient gel electrophoresis (dgge) to detect polymorphisms in the sheep prp gene. in addition to the already described polymorphi ...	1995	7897344
comparative study of electron microscopical techniques for the detection of scrapie-associated fibrils.	samples of cervical spinal cord and four anatomical regions of the brains of 12 sheep with natural scrapie and six control sheep were examined by electron microscopy, after the tissues had been stored at 4 degrees c and -20 degrees c. the tissues were tested for the presence of scrapie-associated fibrils by a centrifugal extraction technique and by a touch-grid technique. the touch-grid technique was no better than the centrifugal extraction technique for the detection of fibrils. structures whi ...	1995	8588101
[scrapie in sheep and transmissible encephalopathy of the mink].	scrapie in sheep and goat is the prototype of the group of the transmissible spongiform encephalopathies which affect man and some animal species, notably other ruminants with bovine spongiform encephalopathy (bse) and chronic wasting disease of wild ruminants. transmissible mink encephalopathy (tme) is a rare disease of ranch-raised mink caused by exposure to a contaminated food ingredient in the ration scrapie, unrecognised bse-like disease...). there is clinical and pathological similarities ...	1995	7777384
seac reports on transmissible spongiform encephalopathies.		1995	7793019
western blot mapping of disease-specific amyloid in various animal species and humans with transmissible spongiform encephalopathies using a high-yield purification method.	saf-protein, an amyloid, is the main constituent of scrapie-associated fibrils (saf) and a specific marker for transmissible spongiform encephalopathies (tse). using an improved extraction method and western blot detection, the disease-specific amyloid was found in various parts of the central nervous system of hamsters orally infected with scrapie, of squirrel monkeys orally infected with kuru, sporadic creutzfeldt-jakob disease (cjd) and scrapie, of human patients with sporadic cjd, of a sheep ...	1995	7595360
a cellular form of prion protein (prpc) exists in many non-neuronal tissues of sheep.	a cellular form of the prion protein (prpc) is thought to be a substrate for an abnormal isoform of th eprion protein (prpsc) in scrapie. prpc is abundant in tissues of the central nervous system, but little is known about the distribution of prpc in non-neuronal tissues of sheep, the natural host of scrapie. this study investigated the tissue distribution of prpc in sheep. although prpc was abundant in neuronal tissues, it was detected in non-neuronal tissues such as spleen, lymph node, lung, h ...	1995	7595362
intracerebral distribution of infectious amyloid protein in spongiform encephalopathy.	we studied the regional distribution of infectious amyloid protein by western immunoblots of brain tissue extracts from 37 patients with different forms of spongiform encephalopathy, i.e., 16 sporadic cases, 18 familial cases with a variety of mutations, and 3 iatrogenic cases. in sporadic and familial creutzfeldt-jakob disease, amyloid protein concentrations were usually highest in the frontotemporal regions of the cerebral cortex, whereas iatrogenic creutzfeldt-jakob disease and gerstmann-strä ...	1995	7654073
[prion diseases. review of the literature on the light of two case reports of creutzfeldt-jakob disease].	during the last ten years the diseases scrapie in sheep and bovine spongiform encephalopathy (or mad cow disease) in cattle have received increased attention. through the 1960s it became apparent that scrapie in sheep and kuru and later creutzfeldt-jakob disease in man were infectious diseases. during the last decade the appearance of mad cow disease in great britain has increased the fear that humans can develop creutzfeldt-jakob disease through their food. a special characteristic of the infec ...	1996	8658476
strain specific and common pathogenic events in murine models of scrapie and bovine spongiform encephalopathy.	the development of transmissible spongiform encephalopathies in experimental models depends on two major factors: the intracerebral accumulation of an abnormal, protease-resistant isoform of prp (prpres), which is a host protein mainly expressed in neurons; and the existence of different strains of agent. in order to make a distinction between pathogenic mechanisms depending upon the accumulation of host-derived prpres and the strain-specific effects, we quantified and compared the sequence of m ...	1996	8758005
protease-resistant prp deposition in brain and non-central nervous system tissues of a murine model of bovine spongiform encephalopathy.	infectivity within the central nervous system has been demonstrated by the transmission of bovine spongiform encephalopathy (bse) from affected cattle to inbred laboratory mice. sedimentable, protease-resistant prp (prpsc) has also been extracted from bse-affected cattle brain. both infectivity and prpsc have been reported in the lymphoreticular tissues of sheep and mice clinically and preclinically affected with scrapie. neither infectivity nor prpsc has yet been detected in non-neural tissues ...	1996	8760446
observations on the transmission of scrapie in experiments using embryo transfer.	this investigation studied the maternal transmission of scrapie in sheep by using embryo transfer to examine the viability of highly susceptible offspring derived from scrapie-affected and uninfected donors. the study also examined the effect of washing the embryos. scrapie occurred in both washed and unwashed embryo-derived sip sasa progeny from both groups of donor ewes. as a result, the earlier observation that scrapie might pass via the unwashed embryo to develop as disease in adult sheep ha ...	1996	8795182
spongiform encephalopathies: still many unanswered questions.		1996	8795492
endosome-lysosomes, ubiquitin and neurodegeneration.	before the advent of ubiquitin immunochemistry and immunogold electron microscopy, there was no known intracellular molecular commonality between neurodegenerative diseases. the application of antibodies which primarily detect ubiquitin protein conjugates has shown that all of the human and animal idiopathic and transmissible chronic neurodegenerative diseases, (including alzheimer's disease (ad), lewy body disease (lbd), amyotrophic lateral sclerosis (als), creutzfeldt-jakob disease (cjd) and s ...	1996	8861020
prp genotype contributes to determining survival times of sheep with natural scrapie.	several allelic variants of the sheep prp gene are associated with scrapie susceptibility. however, it is not known whether, and to what extent, the prp genotype contributes to determining survival times of scrapie sheep. we therefore determined the prp genotype and life spans of over 50 flemish and swifter sheep within a single scrapie-affected flock. eighty-three per cent of the scrapie sheep were homozygous for the prp(vq) allele (polymorphic amino acids at codons 136 and 171 are indicated) a ...	1996	8887505
improvement of prpsc-detection in mouse spleen early at the preclinical stage of scrapie with collagenase-completed tissue homogenization and sarkosyl-nacl extraction of prpsc.	scrapie in sheep has recently become again a target of control measures and eradication programs. crucial for the effectiveness of these measures is the detection of infected sheep during the long and potentially hazardous incubation period. however, routine-diagnosis is mostly limited to clinical examinations when disease becomes apparent, and to postmortem investigations. through the detection of the scrapie-specific isoform of the prion protein (prpsc) by western blot in the spleen and lymph ...	1996	8920821
transmissible spongiform encephalopathies (tse): minimizing the risk of transmission by biological/biopharmaceutical products: an industry perspective.	several guidelines and recommendations have been published on assessing the potential risk of a biological product being contaminated with an agent causing a transmissible spongiform encephalopathy (tse). basic principles which can be used during the manufacturing of biological products to minimize the risk of transmission of tse agents include the following: (i) obtaining animals, tissues or animal-derived raw materials from countries in which the relevant tse agent is reported to be absent; (i ...	1996	9119148
creutzfeldt-jakob disease and bovine spongiform encephalopathy. aetiology of scrapie in certain circumstances is not evidence against another aetiology in different circumstances.		1996	8563543
[prion diseases and a new variant of creutzfeldt-jakob disease].	the causal link of a new variant of cjd (v-cjd) with bovine spongiform encephalopathy (bse) has led to world-wide panic. bse emerged in 1986 through dietary products contaminated with scrapie pathogen, bse case reports increased in number up to 37,000/year in 1993, then declined in 1994 when the first case of v-cjd emerged. there is a 3-year gap between the emergence of bse and the introduction of a ban on the use of specified bovine offal in human food. people might have consumed dietary produc ...	1996	9128415
prp genotypes and experimental scrapie in orally inoculated suffolk sheep in the united states.	one-hundred and three unites states suffolk sheep were inoculated orally with a scrapie agent preparation and monitored for clinical disease and histopathological lesions characteristic of scrapie. a retrospective study of the polymorphisms at codon 171 of the prion protein (prp) gene was performed on these sheep. all 63 sheep that developed scrapie during the observation period were homozygous for the glutamine 171 (171-qq) prp allele. twelve 171-qq sheep failed to develop disease. all 5 sheep ...	1997	9129673
[prion disease in animals and experimental prion disease].		1997	9282362
syrian hamster prion protein (prp(c)) is expressed in photoreceptor cells of the adult retina.	prp(c), the cellular isoform of the prion protein (prp) serves as a precursor to abnormal prp isoforms which accumulate in diseases such as scrapie in sheep, and creutzfeldt-jakob disease in humans. since prions can replicate in photoreceptors we surmised that prp(c) must be expressed in these cells. accordingly, monoclonal antisera directed against two epitopes of hamster prp(c) produced retinal immunostaining in hamsters, and in mice bearing a hamster prp transgene. immunostaining was most pro ...	1997	9347934
[molecular pathogenesis of spongiform encephalopathy].		1997	9489393
bse: can we predict the future?	prion diseases are transmissible neurodegenerative disorders of humans and animals. the prion protein (prpc) gene is expressed to some extent in many cell types but principally in neurons. normal prpc may contribute in the protection of neurons and are protease sensitive. abnormal prions consist of a post-translationally modified form of prp, prpsc, which is partly protease resistant. prpsc is a protein with high resistance to inactivation by irradiation, heat and harsh chemical treatments. it i ...	1997	9581370
biochemical typing of scrapie strains.		1997	9121579
prion protein and the transmissible spongiform encephalopathies.	transmissible spongiform encephalopathies (tses) are fatal neurodegenerative diseases that occur in a wide variety of mammals. in humans, tse diseases include kuru, sporadic and iatrogenic creutzfeldt-jakob disease (cjd), gerstmann-sträussler-scheinker syndrome (gss), and fatal familial insomnia (ffi). so far, tse diseases occur only rarely in humans; however, scrapie is a widespread problem in sheep, and the recent epidemic of bovine spongiform encephalopathy (bse or mad cow disease) has seriou ...	1997	17708907
an antibody raised against a conserved sequence of the prion protein recognizes pathological isoforms in human and animal prion diseases, including creutzfeldt-jakob disease and bovine spongiform encephalopathy.	antibodies to the prion protein (prp) have been critical to the neuropathological and biochemical characterization of prp-related degenerative diseases in humans and animals. although prp is highly conserved evolutionarily, there is some sequence divergence among species; as a consequence, anti-prp antibodies have a wide spectrum of reactivity (from strong immunopositivity to lack of reactivity) when challenged with prp from diverse species. we have produced an antibody (anti-prp95-108) raised a ...	1998	9626045
scrapie.	scrapie and other transmissible spongiform encephalopathies (tses) are characterized by similar pathology, biochemistry and genetics. the prp protein and its conversion to the disease-related isoform, prpsc, are crucial for the development of all tses. although scrapie is more often studied in laboratory rodents, it is not a natural disease of these animals, and much can be learned from the normal hosts, sheep. disease incidence is linked to polymorphisms and mutations of the prp gene. the compl ...	1998	9718582
urodynamic parameters in scrapie-affected ewes and their modifications in the course of the disease.	the aim of this study was to determine the urological abnormalities linked to spontaneous spongiform encephalopathy and their occurrence in the course of the disease. the animals used in this were 11 healthy and 20 scrapie-affected ewes. the scrapie-affected ewes were studied at a rate of once a month (1 to 5 measures; mean, 2.55) until they died. urodynamic explorations were performed. the bladder activity was explored using cystometry. the urethral activity was measured during cystometry and d ...	1998	9776019
complete genomic sequence and analysis of the prion protein gene region from three mammalian species.	the prion protein (prp), first identified in scrapie-infected rodents, is encoded by a single exon of a single-copy chromosomal gene. in addition to the protein-coding exon, prp genes in mammals contain one or two 5'-noncoding exons. to learn more about the genomic organization of regions surrounding the prp exons, we sequenced 10(5) bp of dna from clones containing human, sheep, and mouse prp genes isolated in cosmids or lambda phage. our findings are as follows: (1) although the human prp tran ...	1998	9799790
a mathematical model of the dynamics of scrapie in a sheep flock.	a mathematical model is developed for the dynamics of an outbreak of scrapie in a single sheep flock with the aim of assisting the interpretation of field data. the model incorporates age structure of the sheep population, both horizontal and vertical transmission, genetic predisposition to infection, variable initial load of the infectious agent, and increasing infection load during an incubation period of the same order as sheep life expectancy. this leads to system of partial differential equ ...	1998	9825634
bovine spongiform encephalopathy: current status and possible impacts.	bovine spongiform encephalopathy is an apparently new disease; first recognized in 1985, its pathological distinction was first reported in 1986. bovine spongiform encephalopathy is a member of a group of transmissible encephalopathies that includes scrapie in sheep and creutzfeldt-jakob disease in humans. early indications of its epidemiology suggested that the disease was transmitted via cattle feed containing meat and bone meals from previously infected animals. the tissues most likely to con ...	1998	9839244
the shortest known prion protein gene allele occurs in goats, has only three octapeptide repeats and is non-pathogenic.	the prion protein (prp) gene modulates the incidence and incubation periods of transmissible spongiform encephalopathies of sheep, goats, mice and man. here, a new caprine prp allele encoding the shortest naturally occurring prp protein so far described is reported. this variant contains only three instead of the usual five copies of a short peptide repeat [pro-gln/his-gly-gly-gly-(gly)-trpgly-gln] characteristic of prp, with an additional trp to gly substitution in codon 102. fifteen out of 111 ...	1998	9880037
comparison of scrapie-associated fibril detection and western immunoblotting for the diagnosis of natural ovine scrapie.	detergent- and proteinase k-treated extracts of grey matter were prepared from four regions of the brains of 106 sheep with scrapie, diagnosed clinically and by the demonstration of spongiform encephalopathy. the extracts were examined by electron microscopy for the presence of scrapie-associated fibrils and by western immunoblotting for the disease-specific abnormal prion protein (prpsc). as a diagnostic method, western immunoblotting proved to be more sensitive than electron microscopy, the de ...	1998	9500237
melatonin and prolactin secretion profile in naturally occurring scrapie in ewe.	the 24 hr pattern of melatonin secretion was determined in scrapie-affected ewes during the clinical course of the disease. the melatonin response to a night interruption by a 1 hr period of illumination was also measured. fourteen ewes (seven control and seven scrapie-affected ewes) were subjected to artificial short days (9l:15d). four 24 hr blood sampling sessions separated by about 10 days were performed. ewes were sacrificed when clinical signs had progressed to irreversible recumbency and ...	1998	9510437
synthetic peptide vaccines yield monoclonal antibodies to cellular and pathological prion proteins of ruminants.	transmissible spongiform encephalopathies are closely linked to the accumulation of a pathological isoform of a host-encoded prion protein (prp(c)), designated prp(sc). in an attempt to generate mono- and polyclonal antibodies to ruminant prp, 32 mice were vaccinated with peptide vaccines which were synthesized according to the amino acid sequence of ovine prp. by this approach five prp-reactive polyclonal antisera directed against four different domains of the protein were stimulated. splenocyt ...	1998	9568991
an immunological approach to prion diseases.	ovine scrapie and bovine spongiform encephalopathy are genetic diseases, presenting probably autoimmunity transmissible by the oral route. the absence of immune response in prion diseases indicates a tolerant state for prp(c) and prp(sc). the tolerant state against these diseases should be overcome before immunizing animals. we suggest that an early diagnosis may be possible using polyclonal and monoclonal antibodies specific for either ovine or bovine prp(sc). such reagents could be obtained by ...	1998	9488187
astrocytosis and proliferating cell nuclear antigen expression in brains of scrapie-infected hamsters.	scrapie is a neurodegenerative disease in sheep and goats. neuropathological examination shows astrocytosis. one issue is whether the astrocytosis seen in scrapie is a function of an increase in reactivity of individual cells, or whether there is actual replication of astrocytes. we used double-label immunohistochemistry for proliferating cell nuclear antigen (pcna) and for glial fibrillary acidic protein (gfap) to determine the mitotic state of cells and to confirm their identity as astrocytes. ...	1998	10344795
scrapie-associated prion protein in the gastrointestinal tract of sheep with natural scrapie.	the scrapie-associated prion protein (prpsc), which is closely associated with scrapie infectivity, accumulates in the brain and lymphoid tissues of sheep with natural scrapie. the most probable portal of entry of the scrapie agent in sheep is the alimentary tract; little attention, however, has been paid to the gastro-intestinal tract in scrapie research. in this study, we examined the presence and distribution of prpsc within the gastro-intestinal tract of sheep with natural scrapie and scrapi ...	1999	10373293
risk of transmission of bovine spongiform encephalopathy to humans in the united states: report of the council on scientific affairs. american medical association.	the risk of possible transmission of bovine spongiform encephalopathy (bse) in the united states is a substantial public health concern.	1999	10386559