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[properties of the causative agent of creutzfeldt-jakob disease; current insights into the pathogenesis of dementia]. 19853897875
[prions--the pathogens causing slow infections]. 19853900951
virogenes in scrapie and creutzfeldt-jakob disease. 19853906122
sheep consumption: a possible source of spongiform encephalopathy in humans.a fatal spongiform encephalopathy of sheep and goats (scrapie) shares many characteristics with creutzfeldt-jakob disease (cjd), a similar dementing illness of humans. to investigate the possibility that cjd is acquired by ingestion of contaminated sheep products, we collected information on production, slaughtering practices, and marketing of sheep in pennsylvania. the study revealed that sheep were usually marketed before central nervous system signs of scrapie are expected to appear; breeds k ...19853915057
prions--infectious pathogens causing the spongiform encephalopathies.the novel properties of the scrapie and creutzfeldt-jakob disease (cjd) transmissible agents readily distinguish them from viruses and viroids; thus, they have been labeled "prions". the scrapie prion contains a protein(s) which is required for infectivity; recently a 27,000 to 30,000 mw protein which purifies with the prion has been identified. the similarities between the scrapie and cjd agents suggest that cjd is also caused by a prion. recent studies show that the time courses of both scrapi ...19853915974
creutzfeldt-jakob disease prion proteins in human brains.creutzfeldt-jakob disease is caused by a slow infectious pathogen, or prion. we found that purified fractions from the brains of two patients with creutzfeldt-jakob disease contained protease-resistant proteins ranging in apparent molecular weight from 10,000 to 50,000. these proteins reacted with antibodies raised against the scrapie prion protein prp 27-30. rod-shaped particles were found in the brain tissue of the patients that were similar to those isolated from rodents with either scrapie o ...19853917302
scrapie prp 27-30 is a sialoglycoprotein.the major scrapie prion protein, designated prp 27-30, exhibited both charge and size heterogeneity after purification from infected hamster brains. eight or more discrete charge isomers of prp 27-30 with isoelectric points ranging from approximately ph 4.6 to 7.9 were found by using non-equilibrium ph gradient electrophoresis in the first dimension followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis in the second dimension. the charge isomers were detected by silver staining a ...19853918176
competition between strains of scrapie depends on the blocking agent being infectious.compton white mice (sincs7) were injected twice intraperitoneally, first with the 22a strain of scrapie agent (in brain homogenates) and then, after 105 days, with the 22c strain. incubation periods were calculated from the time of the first injection. the experiment was designed so that, with no interaction between strains, the second strain (22c) should have produced cases about 300-350 days after the first injection, depending on the dose of 22c. this was well before the limit of 470 days set ...19853920169
inactivation of the scrapie agent by ultraviolet irradiation in the presence of chlorpromazine.the sensitivity of the scrapie agent to u.v. inactivation was found to be related to the purity of the tissue preparation. scrapie infectivity associated with membrane vesicles was unaffected when irradiated with 10(4) j/m2. irradiation of more highly purified preparations from detergent-extracted cscl gradient fractions reduced scrapie infectivity from 10(7.8) log10 ld50 per ml to as low as 10(4.5). sensitivity of membrane-associated scrapie infectivity to inactivation by u.v. irradiation could ...19853920348
characterization of proteins in membrane vesicles from scrapie-infected hamster brain.previous studies have shown that the scrapie agent is highly membrane-associated. we examined the protein composition of gradient fractions enriched for large membrane vesicles prepared from scrapie-infected and uninfected hamster brain using various methods to extract membrane proteins. we also examined proteins in detergent-extracted membrane vesicles fractionated on cscl gradients. no qualitative differences in protein composition were seen comparing scrapie-infected and uninfected samples by ...19853920349
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
focusing on the nature of the scrapie agent. 19853921259
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
genetic control of amyloid plaque production and incubation period in scrapie-infected mice.the extent of amyloid plaque production was investigated in three inbred mouse strains carrying the p7 allele of the scrapie incubation (sinc) gene (vm, im and mb). with either me7 or 87v scrapie, many more plaques were seen in the mb strain than in vm or im mice. a backcrossing experiment using 87v suggested the involvement of more than one gene. within this backcrossing experiment there was a positive correlation between mean plaque count and mean incubation period for the various strains and ...19853921669
identification of prion amyloid filaments in scrapie-infected brain.extracellular collections of abnormal filaments composed of prion proteins have been identified in the brains of scrapie-infected hamsters using immunoelectron microscopy. some of the filaments were 1500 nm in length; generally, they exhibited a uniform diameter of 16 nm. rarely, the filaments had a twisted appearance, raising the possibility that they are flattened cylinders or are composed of helically wound protofilaments. the prion filaments possess the same diameter and limited twisting as ...19853922627
antibodies to the scrapie protein decorate prion rods.scrapie is a degenerative, transmissible neurologic disease of sheep and goats which occurs in the absence of any detectable host immune response. antibodies to the scrapie agent have been produced after immunization of rabbits with either scrapie prions or the prion protein, prp 27-30, purified from infected hamster brain. immunoreactivity of the antisera was assessed by dot and western immunoblots with purified prions and prp 27-30. antibodies raised against infectious prions were more immunor ...19853923112
scrapie. persistently puzzling prions. 19853923360
identification of scrapie prion protein-specific mrna in scrapie-infected and uninfected brain.to date no nucleic acid has been found in the purified infectious agent which causes the spongiform encephalopathy known as scrapie. in an attempt to identify a unique scrapie virus-associated messenger rna in tissues of infected animals, we have synthesized an oligonucleotide probe complementary to the mrna sequence corresponding to the amino-acid sequence of the prion protein, prp27-30 (ref. 1). we report here that, with this probe, a complementary dna clone representing prp27-30 was obtained ...19853923361
the 200- and 150-kda neurofilament proteins react with igg autoantibodies from chimpanzees with kuru or creutzfeldt-jakob disease; a 62-kda neurofilament-associated protein reacts with sera from sheep with natural scrapie.sera from 46 chimpanzees with spongiform encephalopathy (18 kuru, 28 creutzfeldt-jakob disease) and sera from 12 sheep with natural scrapie were tested for reactivity with immunoblots of neurofilament preparations obtained from mouse brain. the sera from the chimpanzees reacted mainly with the 200- and 150-kda proteins of the neurofilament triplet and less frequently with the 70-kda component of the triplet and with a 62-kda neurofilament-associated protein. in contrast, the sera of sheep with n ...19853923483
effects of in vitro infection of mouse glial and neuroblastoma cells with the scrapie agent.mouse glial and neuroblastoma cells were infected with the mouse adapted strains c506 and 139a of scrapie agent. lysates of the in vitro infected cells (from the 3rd to the 16th passage) intracerebrally inoculated into cd-1 mice, caused the development of a neurological disease, with characteristic signs of scrapie. morphological changes in scrapie-infected neural cells were observed after about fifteen in vitro passages. in liquid medium, the cloning efficiency of these cells increased. they ac ...19853925869
nature of the scrapie agent: current status of facts and hypotheses. 19853926950
biochemical differences among scrapie-associated fibrils support the biological diversity of scrapie agents.scrapie-associated fibrils (saf) were isolated and purified from animals infected with three different scrapie agents: me7 and 139a in mice, and 263k in hamsters. mouse me7 and 139a saf differed from hamster 263k saf in morphology, sedimentation rate and protein composition. saf from the three scrapie agents were distinguishable from each other by their sensitivity to proteinase k digestion. saf copurified with infectivity in both the hamster and mouse systems. saf appear to be a unique class of ...19853926951
transmission of scrapie in hamsters.hamsters developed scrapie 100-160 days after eating either scrapie-infected hamsters or infected brain. the clinical signs and neuropathology of scrapie transmitted by cannibalism were identical to those observed after intracerebral or intraperitoneal inoculation of the agent. oral transmission of scrapie appears to be extremely inefficient. cannibalism requires a dose of the scrapie agent of approximately 10(9) times greater than that needed to produce the disease by intracerebral injection fo ...19853930630
characterization of scrapie agent isolated from sheep in japan.a pathogenic agent isolated in mice from the brain of a sheep affected by scrapie-like disease was characterized. the incubation period of the disease in the primary transmission from the sheep to mice was longer than in the secondary and the tertiary transmission in the same strain of mice. progressive dilution of the inoculum caused prolongation of the incubation period. the infectivity of the agent in a 10% brain homogenate persisted, but decreased about 10(3) to 10(4) times after heating at ...19853930925
scrapie agent unlike viruses in size and susceptibility to inactivation by ionizing or ultraviolet radiation. 19853932887
"slow infections"--a challenge to traditional concepts. 19853934107
agent replication dynamics in a long incubation period model of mouse scrapie.the dynamics of scrapie agent replication in brain and spleen following intracerebral or intraperitoneal infection were investigated in a model with particularly long incubation periods [im mice (sincp7) infected with 87v scrapie]. in contrast to other mouse scrapie models previously investigated, there was no delay in onset of replication ('zero phase') in spleen using either route of infection, for both routes infectivity levels reached a plateau in spleen, which was maintained for at least 25 ...19853934338
failure to detect scrapie virus in sheep at slaughter in a highly endemic region of france.a study was carried out in a sheep slaughterhouse located in a region of france where scrapie has been endemic for several decades. neuropathological examination of 63 randomly selected lambs and adult sheep revealed no scrapie-related abnormalities, and inoculation of mice with brain, tonsil, lateropharyngeal ganglia, and intestine from the same animals did not transmit scrapie. the failure to detect any evidence of scrapie infection in commercially-bred sheep, the absence of an increased morta ...19853939516
scrapie and creutzfeldt-jakob disease prions.scrapie and creutzfeldt-jakob disease are caused by prions which can be distinguished from both viruses and viroids. aggregates of prions are ultrastructurally and histochemically identical to amyloid. extracellular collections of prions form amyloid plaques within scrapie-infected brain. prion amyloid plaques seem analogous to viral inclusion bodies in that they are composed of causative pathogens and are not merely a consequence of the disease.19853940147
brain tumours in mice, with particular reference to astrocytoma.in a survey of 75,000 brains from 23 inbred mouse strains studied during research work on scrapie, astrocytoma was by far the commonest neuroectodermal tumour. it occurred in vm and brvr mice at a 1% incidence, but was virtually absent from other strains. in vm mice it occurred nearly twice as often in males as in females, sometimes causing neurological signs of circling, depression or spinal paralysis, but more often showing no clinical effects and being discovered only during routine neuropath ...19863957158
lectin histochemistry of scrapie amyloid plaques.peroxidase-labeled lectins were used for detection of specific monosaccharide residues in amyloid plaques in brains of scrapie-infected mice. the lectins tested recognize the following residues: beta-d-galactosyl (ricinus communis agglutinin 120, rca-1), alpha-d-galactosyl and alpha-d-galactopyranoside (bandeirea simplicifolia aggl., bsa), alpha-d-mannosyl and alpha-d-glucosyl (concanavalin a, con a), n-acetylglucosaminyl and sialyl (wheat germ aggl., wga), sialoglycoconjugates (limulus polyphem ...19863962600
electroencephalogram and evoked potentials in naturally occurring scrapie in sheep.electroencephalogram (eeg), brain stem auditory-evoked potential, and flash visual-evoked potential recordings were taken from healthy sheep and from 3 sheep with scrapie, a cns slow virus infection. the eeg changes included semi-periodic, polyphasic, high-voltage sharp waves (bilaterally synchronous and symmetric in all channels), and a cyclic alternating pattern consisting of a high-voltage low-frequency phase, followed by a low-voltage high-frequency phase. the high-voltage phase occurred wit ...19863963585
sheep major histocompatibility complex ola: gene frequencies in two french breeds with scrapie. evidence for a linkage between ola and resistance or susceptibility to the disease.gene frequencies of 13 sheep lymphocyte factors (11 factors controlled by the sheep ola complex including three closely linked loci, and two factors by two minor loci) were compared in 189 sheep of two breeds: a. infected with scrapie, b. healthy in a contaminated environment, and c., normal. in a and c, ola gene frequencies were similar. in healthy sheep in a contaminated environment (b), some ola gene frequencies were higher in one breed and lower in the other. in each breed, three antigens ha ...19853980051
selection of swaledale sheep of reduced susceptibility to experimental scrapie.a flock of 294 swaledale sheep was injected with brain tissue from different sources so as to include strains of natural scrapie currently affecting the swaledale breed. discounting intercurrent deaths, 85 per cent of the flock developed clinical scrapie within an observation period of 2557 days (seven years). scrapie cases fell into distinct early and late groups, occurring at (mean +/- sem) 287 +/- 7 days and 1207 +/- 38 days after injection, respectively. breeding groups were formed from the ...19853984198
[short review on the causative agent of scrapie]. 19854014987
asymmetry of retinal lesions in experimental scrapie after intracerebral inoculation of hamsters.hamsters injected into the right cerebral hemisphere with the scrapie agent developed retinal lesions to a greater extent in the contralateral than in the ipsilateral eye. this asymmetry was evident during the incubation period as well as during the clinical encephalopathy. the results explain much of the variation in the degree of retinal disease seen earlier at specific times after inoculation. moreover, they strengthen the hypothesis that scrapie spreads via neurons.19854038487
serotoninergic system in scrapie-infected hamsters.hamsters inoculated with scrapie virus show a dramatic hypersensitivity to serotoninergic drugs, developing a behavioral syndrome not unlike that obtained with pharmacologically induced lesions of the raphe nuclei. in an attempt to explain the state of hypersensitivity and to determine whether or not serotoninergic neurons were targets of the scrapie virus, pre- and postsynaptic serotoninergic sites were studied in the cerebral cortices of scrapie-infected and sham-inoculated hamsters. [3h]imipr ...19854038735
brain glutamate decarboxylase and cholinergic enzyme activities in scrapie.c57bl/6j mice, age 6-8 weeks were inoculated intracerebrally with brain homogenate from mice previously infected with the 139a strain of scrapie; control mice were identically treated with brain homogenate from non-infected normal mice. the activities of choline acetyltransferase (cat), acetyl cholinesterase (ache), and glutamic acid decarboxylase (gad) were determined in the forebrain and hindbrain of these animals after 67, 126 and 151 days post-inoculation. there were no significant differenc ...19854039359
pathogenesis of mouse scrapie: dynamics of vacuolation in brain and spinal cord after intraperitoneal infection.at the late clinical stage of scrapie in mice, the severity and distribution of vacuolation in the brain (the lesion profile) is largely determined by the strain of agent and the genotype of the mouse: under controlled conditions, lesion profiles can be used to distinguish between scrapie strains. this paper describes the sequential development of lesions in brain at much earlier times and includes a study of spinal cord. mice (cw) were infected intraperitoneally with 139a scrapie. grey matter v ...19854041016
targeting of scrapie lesions and spread of agent via the retino-tectal projection.scrapie infectivity and degenerative vacuolation was initially localized within the contralateral superior colliculus following intraocular injection. the time course of these events was prolonged. with the me7 strain of scrapie in sincs7 genotype mice, infectivity began to rise in the superior colliculus from about 70 days, followed by the earliest asymmetrical lesions there from 120 days, with death occurring at about 250 days, at which time vacuolar degeneration was widespread in the brain. w ...19854052769
neuronal origin of a cerebral amyloid: neurofibrillary tangles of alzheimer's disease contain the same protein as the amyloid of plaque cores and blood vessels.the protein component of alzheimer's disease amyloid [neurofibrillary tangles (nft), amyloid plaque core and congophilic angiopathy] is an aggregated polypeptide with a subunit mass of 4 kd (the a4 monomer). based on the degree of n-terminal heterogeneity, the amyloid is first deposited in the neuron, and later in the extracellular space. using antisera raised against synthetic peptides, we show that the n terminus of a4 (residues 1-11) contains an epitope for neurofibrillary tangles, and the in ...19854065091
effect of prior treatment with thioglycolate on the incubation period of intraperitoneally injected scrapie.injection of mice with thioglycolate 5 days prior to intraperitoneal injection of scrapie brain homogenate led to a statistically significant increase in scrapie incubation periods. this was seen with two different scrapie strains (me7 and 139a), in different mouse strains (c57bl/6j and compton white), and at several dilutions of the scrapie inoculum.19854066255
absence of autoantibodies against neurofilament proteins in the sera of scrapie infected mice.autoantibodies against neurofilament proteins were not detected in any of the sera from the following scrapie infected mice: 19 mice infected with scrapie agent 139a in pre-clinical stage, 32 histologically confirmed scrapie mice and other 12 clinical scrapie mice infected with various strains. the test sera were assayed against acetone-fixed central neuron cultures from fetal mice by indirect immunofluorescence and immunoperoxidase techniques. the negative result suggests that autoantibodies ag ...19854071543
experimental transmission of scrapie to voles and chinese hamsters. 19714099889
early reduction of drinking in mice with scrapie. 19714100232
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
slow infections of the central nervous system. i. 19714102745
slow infections of the central nervous system. ii. 19714105437
scrapie. 19724110651
scrapie in young mice. 19724110680
scrapie: an inefective peptide? 19724111222
scrapie-induced changes in the percentage of polymorphonuclear neutrophils in mouse peripheral blood.a decrease in the percentage of polymorphonuclear neutrophils (pmn) in the peripheral blood of mice appeared 3 days after intracerebral (ic) inoculation with scrapie mouse brain homogenate. mice inoculated ic with normal mouse brain had pmn percentages similar to those found for uninoculated mice. this difference between normal and scrapie-inoculated mice continued throughout the preclinical phase of the disease. in the clinical phase of the disease, the percentage of pmn was either higher or lo ...19724118048
argyrophilic plaques in mice inoculated with scrapie from particular sources. 19734120692
inhibition of rna slow viruses by thiosemicarbazones. 19734122206
scrapie. 19724125191
[disseminated sclerosis and slow virus diseases (author's transl)]. 19734127809
emergence of new antigens in ageing tissues. 19734129994
a rapid immunologic test for scrapie in sheep. 19744132111
ruthenium red and lanthanum nitrate a possible tracer and negative stain for scrapie "particles"? 19744140674
editorial: kuru, creutzfeldt-jakob, and scrapie. 19744140986
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
higher frequency of a protein band in the cerebrospinal fluid from scrapie mice. 19734141787
animal health. 19734148822
accumulations of fat in the brains of mice affected with scrapie. 19664161782
the relative susceptibility of sheep, goats and mice to two types of the goat scrapie agent. 19664163198
adult coeliac disease and neuropathy. 19674164316
scrapie in the rat: an electron-microscope study. i. amyloid bodies and deposits. 19674167043
the scrapie agent. 19674167102
scrapie in the rat: an electron-microscopic study. ii. glial inclusions. 19674169322
nucleotide-sugar enzymes in scrapie. 19684169997
transmission of kuru to mice. 19684171608
the infective process in scrapie. 19684175093
further observations on histochemical changes in scrapie mouse brain. comparison with experimental viral encephalitides. 19684176222
immunological responsiveness of scrapie infected mice. 19694180790
immune processes and infectious factors in central nervous system disease. 19694183762
the occurrence of nerve fiber degeneration in brains of mice inoculated with scrapie. 19694185636
immunofluorescence and cytochemical studies of visna virus in cell culture.sequential morphological changes occurring in sheep choroid plexus cells infected with visna virus were studied by direct immunofluorescence, acridine orange, and hematoxylin and eosin staining methods. specific immunofluorescence was first detected in the perinuclear cytoplasm of solitary cells 24 hr after infection. as the infection progressed, viral antigen appeared in an increasing number of cells, and rounded globular cells with long slender processes harboring intense fluorescence were see ...19674192872
sheep, minks, savages and presenile dementia. the story of slow viruses. 19684195904
amyloidosis, alzheimer's disease, and ageing. 19704196010
[creutzfeldt-jakob's disease. a human spongiform viral encephalopathy]. 19734196163
virus-like particles in natural scrapie of the sheep. 19734196559
transmissible mink encephalopathy: studies on the peripheral lymphocyte.circulating lymphocytes from mink with transmissible mink encephalopathy were studied for the presence of virus particles and for infectivity. electron microscope examination of phytohemagglutinin-stimulated lymphocyte cultures revealed no evidence of virus-like particles. circulating lymphocytes were also found to be noninfectious when the transmissible agent could be demonstrated in intact lymphoid organs in infected mink. a lymphopenia was detected in affected mink during the late clinical st ...19734197388
multiplicity of scrapie virus in infected mouse spleen cells in vivo.subpopulations of spleen cells from scrapie virus-infected mice were used to determine the average virus content of infected cells in vivo at a time when virus was rapidly increasing in titer in lymphoreticular tissues. comparison of the mean lethal doses of lysed to intact cells indicated averages of 2 to 6 infectious units per infected cell. in another experiment, preparations of cytoplasmic nucleic acids extracted from spleen cells of infected mice had no detectable infectivity, which suggest ...19734197750
experimental subacute spongiform virus encephalopathies in primates and other laboratory animals.the host range of subacute spongiform virus encephalopathies is described. the asymptomatic incubation period and the duration of the illnesses in various species of animal hosts is discussed along with information on additional species of old world and new world monkeys and the domestic cat, which have been shown to be susceptible to subacute spongiform virus encephalopathies.19734199733
differences in access into the central nervous system of me7 scrapie agent from two strains of mice. 19734199906
scrapie in mice. some effects on the brain lesion profile of me7 agent due to genotype of donor, route of injection and genotype of recipient. 19734199907
scrapie in mice. agent-strain differences in the distribution and intensity of grey matter vacuolation. 19734199908
altered response to scrapie tissues in neurological disease. possible evidence for an antigen associated with reactive astrocytes. 19734200639
failure to demonstrate a humoral immune response to scrapie infection in mice. 19734200779
immunological reactions in scrapie: the basis of a rapid titration method. 19734204065
[latest achievements in the study of subacute spongious encephalopathies]. 19734204259
course of experimental scrapie virus infection in the goat. 19744207308
depression of polymorph counts by various scrapie agents. 19744207411
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
ultrastructural observations on scrapie in the gerbil. 19734209188
similarities between the scrapie agent and the agent of the potato spindle tuber disease. 19734209370
viral and non-viral properties of the scrapie agent. 19734209651
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