antiviral compound effective against experimental scrapie. 197989602
evidence for the low molecular weight nature of scrapie agent. 1979107457
[discovery of viroids and possible relationship with human and veterinary medicine].the researches of diener and co-workers and those of the semancik's group, have recently established that some plant diseases, such as potato spindle tuber, citrus exocortis disease and chrysanthemum stunt, are caused by a new class of pathogens, named viroids. these are the smallest known agents (they are smaller than viruses) having a molecular weight of ca 10(5) daltons, and composed of a highly structured rna, rich in guanine-cytosine base pairs without a capsid. little is known about the or ...1975132907
newer knowledge in comparative virology--its contribution to human health other comparative sciences, and despite its recent beginning comparative virology has already contributed useful applications and observations to human health research. teachings derived from the study of marek's disease found application in that of burkitt's lymphoma, and may lead to a possible vaccine against the human disease. equally useful information came from the study of canine distemper in the development of a chorio-allantoic membrane attenuated measles vaccine, and in our knowled ...1975167504
slow viral infections. 1979231926
scrapie: a point of view. 1977275684
scrapie- the risks in perspective. 1977276740
scrapie scruples. 1978278924
sedimentation properties of the scrapie agent.the sedimentation behavior of the scrapie agent in homogenates of spleen from infected mice has been determined. approximately 90% of the scrapie agent was sedimented at an omega2t value of 3 x 10(10) rad2/sec in a fixed-angle rotor. sedimentation of the agent was not substantially affected by sonication or by treatment with the detergent sodium deoxycholate. the sedimentation profiles of the scrapie agent were similar to those observed for free polyribosomes, but differed from those exhibited b ...1977412193
[naked deoxyribonucleic acid viroids as the causative agents of neuropathies?]. 1979431739
immunoglobulin g concentrations in the sera of herdwick sheep with natural scrapie. 1979528692
virus-like particles from both control and scrapie-affected mouse brain. 1977559944
pathogenesis of mouse scrapie: effect of route of inoculation on infectivity titres and dose-response curves. 1978563870
genetic markers in herdwick sheep: no correlation with succeptibility or resistance to experimental scrapie.genetic markers were studied in herdwick sheep, bred at compton, with special reference to genetically selected lines which differ in susceptibility or resistance to experimentally produced scrapie. there were no correlations between susceptibility to the disease and albumin, pre-albumin, esterase and haemoglobin phenotypes, and between reduced glutathione levels and alpha-mannosidase isoenzymes, the latter possibly representing a previously undescribed genetic marker in sheep.1977606000
nucleic acids associated with detergent-treated synaptosomal plasma membranes from normal and scrapie-infected mouse brain. 1976828592
[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 ...19921288542
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 ...19921334140
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 ...19921360795
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 ...19921364008
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 ...19921364085
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 ...19921383401
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 ...19921551009
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 ...19921571012
scrapie: a clinical assessment. 19921604786
[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 ...19921615298
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 ...19911669719
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 ...19911688299
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, ...19901693623
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.19911761111
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 ...19911798423
natural transmission and genetic control of susceptibility of sheep to scrapie. 19911810708
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 ...19911826023
diagnosis of scrapie. 19911859542
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 ...19911957458
experimental transmission of scrapie to cattle. 19901971338
detection of bovine spongiform encephalopathy in the united kingdom. 19901971813
structure of scrapie-associated protein and its relation to infectivity. 19901971816
[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.19902094563
proceedings of an international roundtable on bovine spongiform encephalopathy. 19902189852
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 ...19902233424
a questionnaire survey of the prevalence of scrapie in sheep in 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 ...19902260251
tainted feed, mad cows. could a british cattle disease infect u.s. herds? 19902333492
the scrapie control program in the united states. 19902347767
the unexpected export? 19902348869
link between scrapie and bse? 19902366871
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 ...19852408277
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 ...19852409296
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 ...19892507597
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 ...19892574875
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, ...19892690115
scrapie and the sheep mhc: claims of linkage refuted. 19892731967
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.19852857587
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 ...19862940470
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 ...19883221978
bovine spongiform encephalopathy: time to take scrapie seriously. 19883394240
[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 ...19863768187
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- ...19853920350
[prion antibodies and structure analysis clarify questions about atypical viruses. prion structure under the electron microscope]. 19853920456
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.19853921398
"slow infections"--a challenge to traditional concepts. 19853934107
histopathological similarities between scrapie and cuprizone toxicity in mice. 19714101034
drinking behaviour in scrapie. 19714101464
susceptibility of mink to sheep scrapie.a progressive, fatal spongiform polioencephalopathy was induced in mink intracerebrally inoculated with a suspension of brain from a suffolk sheep with naturally acquired scrapie. the clinical signs and pathological lesions of the experimental disease were indistinguishable from transmissible mink encephalopathy, a disease of undetermined origin that occurs in mink.19714102123
an electron microscopic study of the scrapie mouse and rat: further observations on virus-like particles with ruthenium red and lanthanum nitrate as a possible trace and negative stain. 19744141754
the relative susceptibility of sheep, goats and mice to two types of the goat scrapie agent. 19664163198
transmission of kuru to mice. 19684171608
the occurrence of nerve fiber degeneration in brains of mice inoculated with scrapie. 19694185636
scrapie and transmissible mink encephalopathy: search for infectious nucleic acid.brain preparations from animals with scrapie or transmissible mink encephalopathy were phenol extracted and examined for the presence of pathogenic nucleic acid. animals inoculated with various extracts remained healthy, and analysis on 2.6 to 5% polyacrylamide gels failed to detect a difference in extractable rna species between infected and normal mink brain.19744207527
maternal and lateral transmission of scrapie in sheep. 19744212154
slow virus diseases of the central nervous system. 19744213582
pathology of choroid plexus in spontaneous immune complex disease and chronic viral infections. 19744276256
congenital rubella: the significance of virus persistence. 19684304589
effects of antilymphocytic serum on host responses to infectious agents. 19704312737
[visna virus-like particles in cultures of choroid plexus cells of a goat with symptoms of visna infection]. 19744363195
further observations on the production of scrapie in sheep by oral dosing with foetal membranes from scrapie-affected sheep. 19744425935
a new hypothalamic pathway to the median eminence containing neurophysin and its hypertrophy in sheep with natural scrapie. 19734571633
no mouse pmn leukocyte depression after inoculation with brain tissue from multiple sclerosis or spongiform encephalopathies. 19744589575
scrapie: a prototype slow infection. 19724622954
changes in drinking and feeding habits of mice with experimental scrapie. 19724630696
unsuccessful attempts to produce disease with tissues from mice fed on a diet containing cuprizone. 19734736048
clinical and histological recovery from the scrapie-like spongiform encephalopathy produced in mice by feeding them with cuprizone. 19734737068
replication of the factor in scrapie material that causes a decrease in polymorphonuclear neutrophils. 19734737373
a cytological study of the karyotype of spleen cells from scrapie-affected chinese hamsters. 19734738622
naturally-occurring scrapie in goats. 19744859427
viruses and autoimmune diseases in animals other than man. 19714937605
scrapie in immunologically deficient mice. 19714940428
chronic viral infections of the central nervous system. 19714940819
altered plasma membranes in experimental scrapie. 19714942441
multiple sclerosis and scrapie. 19654956117
pathogenesis of scrapie virus infection in the mouse. 19674961240
some factors controlling the incidence of scrapie in cheviot sheep injected with a cheviot-passaged scrapie agent. 19684970193
slow, latent and temperate virus infections of the central nervous system. 19684978852
a comparison of some biological characteristics of the mouse-passaged scrapie agents, 22a and me7. 19694978935
[isolation and identification of maedi--visna virus from a german sheep herd]. 19704992952
transmission and characterization of the agents of spongiform virus encephalopathies: kuru, creutzfeldt-jakob disease, scrapie and mink encephalopathy. 19715000225
[human and animal neuropathology and the slow and latent viruses]. 19715003725
inoculation of voles, chinese hamsters, gerbils and guinea-pigs with scrapie brain material. 19725065061
[new observations on the occurrence of a rna-dependent dna-polymerase]. 19715102738
brain cell cultures from mice affected with scrapie or fed with cuprizone. 19715107104
scrapie--eradication and field trial study of the natural disease. 19695392186
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