| 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 |
| bovine spongiform encephalopathy (bse): the current situation and research. | bovine spongiform encephalopathy (bse), discovered in great britain in 1986, was to pose one of the most serious threats to the well-being of the british cattle industry this century. the disease is now established as a member of the group of diseases known as the sub-acute spongiform encephalopathies caused by unconventional, transmissible agents and which includes scrapie of sheep. it is from scrapie of sheep that it appears bse has resulted though it is possible bse may have existed in a sub- ... | 1991 | 1761112 |
| tubulovesicular structures in human and experimental creutzfeldt-jakob disease. | tubulovesicular structures (tvs) have been consistently observed in brain tissue of animals with transmissible spongiform encephalopathies such as natural and experimental scrapie, bovine spongiform encephalopathy, and experimental creutzfeldt-jakob disease (cjd). in this communication we demonstrate for the first time the presence of tvs in natural cjd. tvs were detected in all 3 cjd specimens. however, they were rare and were found only in one or two locations per grid. they were seen in diste ... | 1991 | 1761114 |
| experimental drug treatment of scrapie: a pathogenetic basis for rationale therapeutics. | pharmacological treatment with polyanions or amphotericin b in hamsters with experimental scrapie reveals that it is possible to delay the appearance of the disease only when the drug is given before the invasion of the agent into the clinical target areas of the brain. we suggest such early treatment may be possible for individuals at high risk of acquiring the disease, such as healthy mutation-positive relatives of patients with familial creutzfeldt-jakob disease or gerstmann-sträussler syndro ... | 1991 | 1761115 |
| the ultrastructural diversity of scrapie-associated fibrils isolated from experimental scrapie and creutzfeldt-jakob disease. | several different samples of scrapie-associated fibrils (saf) were extracted in identical fashion from the brains of golden syrian hamsters infected with the 263k strain of scrapie agent and nih swiss mice infected with the fujisaki strain of creutzfeldt-jakob disease (cjd) agent. based on a total of over 500 measurements in individual fibrils in different extracts, hamster fibrils were more abundant, thicker and had better defined substructure than mouse fibrils. hamster protofibrils were usual ... | 1991 | 1770176 |
| evidence for biological and structural diversity among scrapie strains. | | 1991 | 1725770 |
| ultrastructural studies of prions. | | 1991 | 1725771 |
| spiroplasmas and spongiform encephalopathies. | | 1992 | 1736068 |
| detection of scrapie-associated fibrils in scrapie in goats. | | 1991 | 1776227 |
| scrapie investigation. | | 1991 | 1776229 |
| comparison of bovine spongiform encephalopathy risk factors in the united states and great britain. | | 1991 | 1778735 |
| combination ultrafiltration and 6 m urea treatment of human growth hormone effectively minimizes risk from potential creutzfeldt-jakob disease virus contamination. | although genetically engineered human growth hormone (hgh) is now commercially available, native pituitary-derived hgh is still used by physicians in many countries for the treatment of hormone deficiency states. we describe a method using ultrafiltration and 6 m urea that reduced infectivity in human pituitary tissue that had been deliberately contaminated with scrapie virus (an animal analogue of human creutzfeldt-jakob disease virus) from an initial level of 10(9.7) infectious units to just 5 ... | 1991 | 1806470 |
| transmissible spongiform encephalopathies: scrapie, bse and related human disorders. | | 1991 | 1810706 |
| scrapie strain variation and its implications. | | 1991 | 1810707 |
| natural transmission and genetic control of susceptibility of sheep to scrapie. | | 1991 | 1810708 |
| the scrapie agent in vitro. | | 1991 | 1810709 |
| bovine spongiform encephalopathy. | | 1991 | 1810710 |
| evidence for intrinsic control of scrapie pathogenesis in the murine visual system. | using the optic nerve to route scrapie infection into the brain reduces the initial spread of the disease to well-defined neuronal relays, and simplifies the observation of cause and effect of agent transport, replication and degeneration of the nervous system. one drawback of intraocular targeting of infection is the relatively long incubation periods required to produce clinical disease. by using highly-enriched fractions of infectivity and two models of murine scrapie, we have found that this ... | 1991 | 1791991 |
| bovine spongiform encephalopathy: epidemiological studies on the origin. | the results of further epidemiological studies of bovine spongiform encephalopathy (bse) support the previous findings that the onset of exposure of the cattle population to a scrapie-like agent, sufficient to result in clinical disease, occurred in 1981/82. the onset of this exposure was related to the cessation, in all but two rendering plants, of the hydrocarbon solvent extraction of fat from meat and bone meal. a further possible explanation, related to the geographical variation in the repr ... | 1991 | 1823120 |
| 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 |
| inactivation of bse agent. | although there are no data reported yet for inactivation of bse agent it is reasonable in the interim, to draw upon existing data for other transmissible degenerative encephalopathies (tde), much of which derives from experiments with the scrapie agent. such studies suggest that no standard chemical or physical decontamination procedure will reliably inactivate the amount of scrapie/bse infectivity present in worst-case situations but high concentrations of sodium hypochlorite or sodium hydroxid ... | 1991 | 1794635 |
| 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 |
| [creutzfeldt-jakob syndrome--a disease of viral etiology and genetic pathogenesis: transmitted cerebral amyloidosis induced by viral infection]. | i summarized the newest data concerning the etiopathogenesis of slow virus disorders, mainly scrapie and creutzfeldt-jakob disease. while there is no doubt that prp plays a pivotal role in scrapie pathogenesis, the direct proof that it is also a part of, or the entire scrapie virus is still lacking. point mutations discovered in the human prp gene, prnp, may actually cause the disease or they may contribute only to the process of amyloid deposition similar to other cerebral amyloidoses. | 1991 | 1811184 |
| protease sensitivity and nuclease resistance of the scrapie agent propagated in vitro in neuroblastoma cells. | the scrapie agent has been propagated in vitro in mouse neuroblastoma cells. to further characterize the tissue culture-derived scrapie agent, we studied the effects of protease and nuclease digestion on the agent derived from these cells. the scrapie agent in these cells was found to be resistant to protease digestions for short times but was inactivated by prolonged digestion at high protease concentrations. in contrast, digestion with a variety of nucleases did not alter the agent titer. thes ... | 1991 | 1846182 |
| nucleoside diphosphatase (ndpase) activity associated with human beta-protein amyloid fibers. | nucleoside diphosphatase (ndpase) activity was studied by electron microscope cytochemistry in surgical specimens obtained from aged human cerebral cortices. the presence of ndpase activity on the surface of the microglial cells (mcs) and especially within the endoplasmic reticulum (er) cisternae that are filled with amyloid fibers and that are in continuity with the extracellular amyloid deposits in plaques suggests a possible role of this enzyme in final elaboration of amyloid protein. the clo ... | 1991 | 1851361 |
| an overview of bovine spongiform encephalopathy. | none of the diseases caused by the "unconventional slow viruses" is highly infectious in its natural host. transmission of infection to other species only occurs if the effective dose is high enough to overcome the species barrier. the current epidemic of bovine spongiform encephalopathy (bse) in the u.k. is believed to have been initiated by scrapie infection of cattle via contaminated meat and bone meal in concentrated feedstuffs. but the effective exposure was extremely low. subsequently the ... | 1991 | 1838995 |
| genetic aspects of amyloidosis. | | 1991 | 1839349 |
| localization of amyloidogenic proteins and sulfated glycosaminoglycans in nontransmissible and transmissible cerebral amyloidoses. | we report the localization of amyloid beta-protein and sulfated glycosaminoglycans in senile plaques and vascular amyloid deposits in brain tissues from patients with down's syndrome and alzheimer's disease, and in neurofibrillary tangles of these diseases and those of guamanian parkinsonism-dementia and amyotrophic lateral sclerosis. we also report the immunolocalization of scrapie amyloid in amyloid plaques containing glycosaminoglycans in kuru, creutzfeldt-jakob disease, and gerstmann-sträuss ... | 1991 | 1833944 |
| neuropathological changes in scrapie and alzheimer's disease are associated with increased expression of apolipoprotein e and cathepsin d in astrocytes. | with the rationale that the neuropathological similarities between scrapie and alzheimer's disease reflect convergent pathological mechanisms involving altered gene expression, we set out to identify molecular events involved in both processes, using scrapie as a model to study the time course of these changes. we differentially screened a cdna library constructed from scrapie-infected mice to identify mrnas that increase or decrease during disease and discovered in this way two mrnas that are i ... | 1991 | 1870200 |
| concerned about scrapie. | | 1991 | 1874660 |
| diagnosis of scrapie. | | 1991 | 1859542 |
| [spongiform encephalopathy in a red-necked ostrich (struthio camelus)]. | the paper describes anamnestic, macroscopic and microscopic findings in a female ostrich (struthio camelus), euthanatized because of central nervous and locomotion disorders. systemic arteriosclerotic lesions were combined with adiposis and signs of spongiform encephalopathy, localized in the brain stem and the medulla oblongata. aetiopathogenesis of the disease remains unknown. differential diagnosis is discussed and the disease compared to similar findings in mammals which suffered from bse/sc ... | 1991 | 1887441 |
| search for a putative scrapie genome in purified prion fractions reveals a paucity of nucleic acids. | scrapie can be transmitted by novel infectious pathogens termed prions. no evidence for a scrapie-specific nucleic acid has been detected to date. to investigate amounts, types and sizes of nucleic acid molecules associated with prions in purified preparations, aliquots were deproteinized, and the nucleic acids analysed by page and silver staining. digestion with nucleases and exposure to zn2+ prior to analysis substantially diminished the content of nucleic acids, but did not alter the prion ti ... | 1991 | 1899270 |
| variation in the characteristics of 10 mouse-passaged scrapie lines derived from five scrapie-positive sheep. | ten mouse-passaged scrapie lines were initiated from five sheep with clinical scrapie. of the lines, five were initiated and passaged exclusively in mice with the s7s7 genotype and the remaining five lines were initiated in mice with the p7p7 genotype, with two of these lines subsequently being passaged exclusively in p7p7 mice and two being passaged mainly in p7p7 mice. lines were passaged three or four times and two parameters were compared: incubation period and the induction of a weight incr ... | 1991 | 1899690 |
| genetics of prion infections. | although the infectious prions causing scrapie and several human transmissible neurodegenerative diseases resemble viruses in many respects, molecular and genetic analyses indicate that prions are fundamentally different from viruses in their structure and the mechanisms by which they cause disease. the only macromolecule that has been identified in infectious prion preparations is a disease-specific isoform of the prion protein, which is encoded by a host gene. a growing body of data supports t ... | 1991 | 1903568 |
| [scrapie, still always a puzzling infection]. | scrapie belongs to the spongiform encephalopathies in man and animals. the nature of the infectious agent, an "unconventional virus", has not been elucidated so far. the agent starts to replicate in lymphoid tissue, reaches high titers in the brain and induces the formation of amyloid in this organ. after trials to purify the agent, the infectivity proved to be associated with a protein, which has therefore been called "prion", and with rod-like structures from brain tissue (scrapie-associated f ... | 1991 | 1904658 |
| resistance of the me7 scrapie agent to peracetic acid. | mouse brain infected with the me7 strain of scrapie agent was exposed for 24 h to a range of concentrations of paa, either as fragments of intact brain or as supernates of homogenised brain. two % paa inactivated the infectivity in intact tissue but not in a supernate. none of the concentrations tested (up to 19%) was effective with supernates, and this was considered to result from the protection afforded by aggregation of infectivity-containing particles. | 1991 | 1904666 |
| [the formation of infectious scrapie-like structures in the persistence of the agent of amyotrophic leukospongiosis in a brain cell culture]. | electron microscopic analysis of specimens from guinea-pig brain cell cultures infected with amyotrophic leucospongiosis agent (belonging to "unconventional" viruses) revealed accumulation in the culture fluid of abnormal filamentous structures similar to scrapie-associated fibrils (saf) differing in morphology. most of these saf-like structures 10-15 nm in diameter contained helically wound protofilaments with a repeat at certain intervals (50-150 nm). when these structures were inoculated into ... | 1991 | 1907054 |
| impaired thermal inactivation of me7 scrapie agent in the presence of carbon. | | 1991 | 1909069 |
| natural scrapie: detection of fibrils in extracts from the central nervous system of sheep. | extracts from the cervical spinal cord and from the medulla, thalamus, cerebellum and cerebral cortex of the brains of 10 sheep, histopathologically confirmed as cases of scrapie, were examined by electron microscopy for the presence of scrapie-associated fibrils. characteristic fibrils were observed in all the extracts except for that from the thalamus of one sheep. no fibrils were found in any extracts from three control sheep. a comparison of these results with a similar study of 22 cases of ... | 1991 | 1909476 |
| scrapie in cyprus. | scrapie was first recorded in cyprus in 1985 in two flocks of sheep and subsequently the disease was diagnosed in dairy goats kept in mixed flocks with affected sheep. by 1989 scrapie had been diagnosed in 23 flocks. epidemiological data presented in the present study are essentially from clinicopathological investigations between 1985 and 1989. a total of 356 out of 957 sheep and 10 out of 30 goats examined from flocks in nicosia, larnaca and limassol districts showed histopathological lesions ... | 1991 | 1868319 |
| creutzfeldt-jakob disease and blood transfusion. | | 1991 | 1912871 |
| scrapie inoculation of mice: light and electron microscopy of the superior colliculi. | ultrastructural examination of the superior colliculi of mice intraocularly inoculated with the me7 strain of scrapie showed vacuolation early in the course of infection. brains were examined between 85-260 days after monocular inoculation with scrapie. the mean incubation period for the development of clinical disease was 302 days. vacuolation was seen initially in the contralateral superior colliculus and subsequently in the ipsilateral colliculus. in coded trials light microscopical vacuolati ... | 1991 | 1858484 |
| human gliomas and epileptic foci express high levels of a mrna related to rat testicular sulfated glycoprotein 2, a purported marker of cell death. | clone ptb16 has been isolated by differential screening of a human glioma cdna library. northern blot analysis has shown that ptb16 expression is several times (greater than 11-fold) higher in gliomas than in a primitive neuroectodermal tumor. this observation was supported by in situ hybridization and extended to nine other gliomas. expression was virtually absent in adenocarcinoma cells metastasized to brain. malignant gliomas showed stronger hybridization than benign gliomas, while blood capi ... | 1991 | 1924317 |
| sheep and goat health scheme. | | 1991 | 1926688 |
| [creutzfeldt-jakob disease and gerstmann-sträussler syndrome with reference to their differential diagnosis]. | differential diagnosis has quite often proved to be difficult between creutzfeldt-jakob disease (cjd) and gerstmann-straussler syndrome. clinical and morphological aspects as well as the pathological course and differential diagnosis of cjd and gerstmann-strüssler syndrome are discussed in some detail. slow influence can be morphologically diagnosed with reference to the overall pattern of individual alterations with inclusion of scrapie-associated fibrils. this morphological diagnosis can be ve ... | 1991 | 1911728 |
| measurement of the concentration of amphotericin b in brain tissue of scrapie-infected hamsters with a simple and sensitive method. | a simple, sensitive, and reproducible assay for the measurement of the amphotericin b concentration in tissue extracts was developed by using the fourth derivative of the absorption spectrum of amphotericin b between wavelengths of 330 and 430 nm. the amphotericin b concentration in spleen and brain was proportional to the total amount administered. the amphotericin b concentration in the brain was highly correlated with the increase in the mean incubation period of intracerebrally scrapie-infec ... | 1991 | 1929313 |
| a 'unified theory' of prion propagation. | there is now very persuasive evidence that the transmissible agent for spongiform encephalopathies such as scrapie, consists of a modified form of the normal host protein prpc, devoid of any nucleic acid. on the other hand, because there are many different strains of scrapie agent with distinct phenotypes which can be propagated in animals homozygous for the prpc gene, it has been suggested that a nucleic acid must be a component of the agent. can the two views be reconciled? | 1991 | 1876183 |
| [spongiform encephalopathies caused by slow viruses from the inorganic world?]. | | 1991 | 1937256 |
| increased multimeric mitochondrial dna in the brain of scrapie-infected hamsters. | we observed a marked increase in multimeric mitochondrial dna (mtdna) in brains of scrapie-infected hamsters compared with those of uninfected hamsters. homogenized brain tissue was subjected to subcellular fractionation to isolate scrapie-associated fibrils and tubulofilamentous structures. nucleic acids were extracted from the scrapie-associated fibril/tubulofilament fraction which also contained mitochondria. agarose gel electrophoresis revealed a band corresponding to the size of circular ha ... | 1991 | 1938303 |
| prions and prion proteins. | neurodegenerative diseases of animals and humans including scrapie, bovine spongiform encephalopathy, and creutzfeldt-jakob disease are caused by unusual infectious pathogens called prions. there is no evidence for a nucleic acid in the prion, but diverse experimental results indicate that a host-derived protein called prpsc is a component of the infectious particle. experiments with scrapie-infected cultured cells show that prpsc is derived from a normal cellular protein called prpc through an ... | 1991 | 1916104 |
| more on scrapie. | | 1991 | 1955355 |
| 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 |
| [bovine spongiform encephalopathy: a review]. | transmissible spongiform encephalopathies are a group of chronic, always fatal diseases affecting the central nervous system of humans and animals. they occur in all species and are probably caused by agents called prions. in this minireview, a first part provides an overview of the various disease forms, a second part is devoted to the molecular biology of transmissible spongiform encephalopathies, and a last part deals with the specific problems of the bovine spongiform encephalopathy. | 1991 | 1962178 |
| ultrastructure of the cells forming amyloid fibers in alzheimer disease and scrapie. | ultrastructural, three-dimensional reconstruction of cells surrounding the amyloid star in classical plaques in alzheimer disease (ad) and histochemical studies of the cells associated with the deposits of amyloid fibers in scrapie were carried out. these studies showed that in both diseases, the fibers appear within the smooth endoplasmic reticulum (er) and infoldings of cytoplasmic membranes of microglia/macrophages. additional information about the site of formation of the amyloid fibers deri ... | 1990 | 1963537 |
| neuronal autophagy in experimental scrapie. | in this study we report the formation of giant autophagic vacuoles (av) in neurons in experimental scrapie in hamsters. autophagy is an important step in the cellular turnover of proteins and organelles. it is known to occur in neurons under physiological as under pathological conditions. giant av, however, are seen very rarely only in pathological states. in our model av are much more numerous after intracerebral (i.c.) transmission of the scrapie agent than after the transmission via the intra ... | 1991 | 1927279 |
| virus-induced amyloidoses. | after a short introduction into the general concept of amyloidoses and the genetic disposition involved in these diseases, the genetic disposition for unconventional virus diseases (or transmissible spongiform encephalopathies) and the disease specific amyloid are described. experimental studies on the pathogenesis and the infectious agent suggest that scrapie and related diseases are virus-induced amyloidoses of the brain. | 1991 | 1930093 |
| normal and scrapie-associated forms of prion protein differ in their sensitivities to phospholipase and proteases in intact neuroblastoma cells. | previous studies have indicated that scrapie infection results in the accumulation of a proteinase k-resistant form of an endogenous brain protein generally referred to as prion protein (prp). the molecular nature of the scrapie-associated modification of prp accounting for proteinase k resistance is not known. as an approach to understanding the cellular events associated with the prp modification in brain tissue, we sought to identify proteinase k-resistant prp (prp-res) in scrapie-infected ne ... | 1990 | 1968104 |
| scrapie and cellular prion proteins differ in their kinetics of synthesis and topology in cultured cells. | both the cellular and scrapie isoforms of the prion protein (prp) designated prpc and prpsc are encoded by a single-copy chromosomal gene and appear to be translated from the same 2.1-kb mrna. prpc can be distinguished from prpsc by limited proteolysis under conditions where prpc is hydrolyzed and prpsc is resistant. we report here that prpc can be released from the surface of both normal-control and scrapie-infected murine neuroblastoma (n2a) cells by phosphatidylinositol-specific phospholipase ... | 1990 | 1968466 |
| analysis of linkage between scrapie incubation period and the prion protein gene in mice. | a single gene is known to have a predominant influence on scrapie incubation period in mice. in crosses between strains that give a short incubation period, such as nzw mice, and those which give a long incubation period, such as i/lnj mice, long incubation period was dominant using a chandler scrapie agent isolate. recently a close linkage was found between the incubation period gene and the prion protein (prp) structural gene in i/lnj mice crossed to nzw mice. because this linkage suggested an ... | 1990 | 1968507 |
| does the infective agent of scrapie replicate without nucleic acid? an assessment. | the dogma of a unique status for the scrapie agent falling outside the virological spectrum is critically examined in the light of the circumstances which gave rise to it, and it is concluded that such an extreme view cannot be justified. the dogma arose in the first place by a combination of inadequate methodology and the lack of comparable data from other systems. it has been sustained partly by the same factors, and partly by a general failure to understand the impact on all relevant investig ... | 1991 | 1943871 |
| stem loops in hiv and prion protein mrnas. | tat-dependent trans-activation in hiv requires presentation of a cuggg pentanucleotide at the end of a stem loop within the tar site of the viral long terminal repeat. a tandem repeat within the open reading frame of the prion protein (prp) mrna is able to form similar stem loop structures with which the hiv tat protein could interact, disturbing prp translation. self-amplification of such a disturbance has been suggested as the cause of the scrapie group of diseases, including the scrapie-like ... | 1990 | 1967310 |
| rapid detection of creutzfeldt-jakob disease and scrapie prion proteins. | creutzfeldt-jakob disease (cjd) and gerstmann-sträussler syndrome (gss) of humans as well as scrapie of animals are caused by prions. the scrapie prion protein isoform (prpsc) is the only macromolecule identified to date which is a component of the infectious prion particle. prpsc is converted to prp 27-30 by limited proteolysis while the cellular isoform, designated prpc, is completely digested under the same conditions. elisa studies demonstrated that native prp 27-30 bound to plastic surfaces ... | 1990 | 1967489 |
| cellular isoform of the scrapie agent protein participates in lymphocyte activation. | the scrapie agent protein (sp33-37 or prpsc) is the disease-associated isoform of a normal cellular membrane protein (cp33-37 or prpc) of unknown function. we report that normal human lymphocytes and lymphoid cell lines, but not erythrocytes or granulocytes, express prpc mrna and protein. prpc is detectable on the surface of lymphocytes; the surface immunoreactivity is sensitive to phosphatidylinositol-specific phospholipase c, indicating glycosyl-phosphatidylinositol membrane anchorage. lymphoc ... | 1990 | 1969332 |
| two alleles of a neural protein gene linked to scrapie in sheep. | sheep are the natural hosts of the pathogens that cause scrapie, an infectious degenerative disease of the central nervous system. scrapie-associated fibrils [and their major protein, prion protein (prp)] accumulate in the brains of all species affected by scrapie and related diseases. prp is encoded by a single gene that is linked to (and may be) the major gene controlling the incubation period of the various strains of scrapie pathogens. to investigate the role of prp in natural scrapie, we ha ... | 1990 | 1969635 |
| subcellular distribution and physicochemical properties of scrapie-associated precursor protein and relationship with scrapie agent. | we studied the biologic properties of hamster-adapted scrapie (strain 263k) and its relationship to the precursor protein of scrapie (prp33-35sc). the highest titer of infectious material and the greatest concentration of prp33-35sc were in the fractions containing microsomal and synaptosomal membranes. we found traces of infectivity in the absence of prp33-35sc associated with matrix protein. partitioning of membranes with neutral chloroform-methanol resulted in concentration of prp33-35sc and ... | 1990 | 1969124 |
| scrapie-associated precursor proteins: antigenic relationship between species and immunocytochemical localization in normal, scrapie, and creutzfeldt-jakob disease brains. | we describe the antigenic properties and detection of a normal isoform of scrapie-associated precursor protein (prp33-35c) in normal, and both normal and scrapie isoforms in scrapie- or creutzfeldt-jakob disease (cjd)-infected mouse, hamster, and human brains, using a variety of specific antibodies. polyclonal antibodies raised against mouse and hamster prp27-30 and against a synthetic peptide of the n-terminal sequence of this protein were used as immunologic probes. prp27-30 purified as a prim ... | 1990 | 1969126 |
| scrapie infectivity and prion protein are distributed in the same ph range in agarose isoelectric focusing. | we separated lysed synaptosomal-microsomal membrane fraction from scrapie-infected hamster brain in preparative agarose isoelectric focusing. we also studied the distribution of prp27-30 and scrapie infectivity in 13 regions of the gel in the range of ph 3.5 to 9.3. most of the infectivity remained in the trough, where it had been placed at the beginning of the electrophoresis, along with prp27-30. scrapie infectious particles that encountered the gel demonstrated charge heterogeneity and were d ... | 1990 | 1969125 |
| detection of bovine spongiform encephalopathy in the united kingdom. | | 1990 | 1971813 |
| scrapie isoform of scrapie-associated protein. | | 1990 | 1971814 |
| laboratory markers for detection of scrapie. | | 1990 | 1971815 |
| structure of scrapie-associated protein and its relation to infectivity. | | 1990 | 1971816 |
| attempts to detect evidence of scrapie-associated protein in bovine tissue-derived products. | | 1990 | 1971817 |
| presence of mitochondrial d-loop dna in scrapie-infected brain preparations enriched for the prion protein. | the prion preparation has, in recent years, been the focal point of scrapie research. the inability to identify agent-specific nucleic acids in this sample has led to the formulation of the infectious protein or prion hypothesis. in this study, we analyzed three different prion protein-enriched preparations and found all to contain significant amounts of mitochondrial nucleic acid. southern blot analyses indicated that they are enriched for a specific component of the mitochondrial genome, the s ... | 1990 | 1972202 |
| the mrna encoding the scrapie agent protein is present in a variety of non-neuronal cells. | prp 27-30, a unique protease-resistant protein associated with scrapie infectivity, derives from the proteolytic cleavage of a larger precursor encoded by a host gene. to identify sites of prp biosynthesis, in situ hybridization was done using cloned prp cdna as a probe. in rodent brain, prp mrna was expressed in neurons, ependymal cells, choroid plexus epithelium, astrocytes, pericytes, endothelial cells and meninges of both scrapie-infected and uninfected animals. prp mrna was also detected in ... | 1990 | 1972856 |
| bse in perspective. | | 1990 | 1971325 |
| differential release of cellular and scrapie prion proteins from cellular membranes by phosphatidylinositol-specific phospholipase c. | the abnormal isoform of the scrapie prion protein prpsc is both a host-derived protein and a component of the infectious agent causing scrapie. prpsc and the normal cellular isoform prpc have different physical properties that apparently arise from a posttranslational event. both prp isoforms are covalently modified at the carboxy terminus by a glycoinositol phospholipid. using preparations of dissociated cells derived from normal and scrapie-infected hamster brain tissue, we find that the major ... | 1990 | 1974460 |
| identification of cellular proteins binding to the scrapie prion protein. | the scrapie prion protein (prpsc) is an abnormal isoform of the cellular protein prpc. prpsc is found only in animals with scrapie or other prion diseases. the invariable association of prpsc with infectivity suggests that prpsc is a component of the infectious particle. in this study, we report the identification of two proteins from hamster brain of 45 and 110 kda (denoted prp ligands pli 45 and pli 110) which were able to bind to prp 27-30, the protease-resistant core of prpsc on ligand blots ... | 1990 | 1974464 |
| molecular mass, biochemical composition, and physicochemical behavior of the infectious form of the scrapie precursor protein monomer. | a highly purified fraction obtained from scrapie (263-k strain)-infected hamsters' brains by an alternative procedure without proteinase k treatment contained a protease-resistant form of the scrapie precursor protein (prpsc) and infectivity of 9.9 +/- 0.7 log ld50/ml. polyclonal antibodies produced against hamster scrapie amyloid protein (prp27-30) and used in a neutralization test diminished infectivity of the prpsc preparations by 1.6 log after intracerebral inoculation and by 1 log after int ... | 1990 | 1974720 |
| mutation in codon 200 of scrapie amyloid protein gene in two clusters of creutzfeldt-jakob disease in slovakia. | | 1990 | 1975028 |
| experimental transmission of scrapie to cattle. | | 1990 | 1971338 |
| differential glycosylation of the protein (prp) forming scrapie-associated fibrils. | prp is a glycoprotein found in normal brain. in brain affected by scrapie it forms scrapie-associated fibrils (saf). prp from saf shows considerable heterogeneity of size and charge on two-dimensional gels. it separates into six major regions, the three more acidic regions arising as a result of partial proteolytic degradation. the two more basic higher mr forms (mr 34,000 and 29,000) of prp can be reduced in apparent mr to a lower mr form (mr 25,000) with peptide-n-glycosidase f. in addition, a ... | 1990 | 1969925 |
| transgenetic studies implicate interactions between homologous prp isoforms in scrapie prion replication. | transgenic (tg) mice expressing both syrian hamster (ha) and mouse (mo) prion protein (prp) genes were used to probe the mechanism of scrapie prion replication. four tg lines expressing haprp exhibited distinct incubation times ranging from 48 to 277 days, which correlated inversely with haprp mrna and haprpc. bioassays of tg brain extracts showed that the prion inoculum dictates which prions are synthesized de novo. tg mice inoculated with ha prions had approximately 10(9) id50 units of ha prio ... | 1990 | 1977523 |
| ubiquitin conjugate immunoreactivity in the brains of scrapie infected mice. | sections of brain from normal mice or clinically-ill mice infected with either the 87v or the me7 strains of sheep scrapie were immunostained to show the localization of ubiquitin-protein conjugates or a specific marker of disease, the scrapie-associated fibril protein (prp). in both scrapie models immunoreactive ubiquitin-protein conjugates were seen in thread-like structures found throughout the neuropil, in inclusion bodies within vacuolated neurones, and in areas surrounding anti-prp positiv ... | 1990 | 1977900 |
| immunolocalization of heparan sulfate proteoglycans to the prion protein amyloid plaques of gerstmann-straussler syndrome, creutzfeldt-jakob disease and scrapie. | previous histochemical studies have demonstrated highly sulfated glycosaminoglycans (gags) localized to the amyloid plaques in the brains of humans and animals with prion diseases (snow et al., acta neuropathol 77:337, 1989). however, the identity of the specific class of proteoglycan/gag present was not known. the current investigation used immunocytochemical techniques to identify and localize heparan sulfate proteoglycans (hspgs) in human cases of gerstmann-straussler syndrome and creutzfeldt ... | 1990 | 1977959 |
| bovine spongiform encephalopathy. | | 1990 | 1978125 |
| acquisition of protease resistance by prion proteins in scrapie-infected cells does not require asparagine-linked glycosylation. | the scrapie and cellular isoforms of the prion protein (prpsc and prpc) differ strikingly in a number of their biochemical and metabolic properties. the structural features underlying these differences are unknown, but they are thought to result from a posttranslational process. both prp isoforms contain complex type oligosaccharides, raising the possibility that differences in the asparagine-linked glycosylation account for the properties that distinguish prpc and prpsc. scn2a and schab cells i ... | 1990 | 1978322 |
| identification of glycoinositol phospholipid linked and truncated forms of the scrapie prion protein. | analysis of carboxy-terminal peptides derived from endoproteinase lys-c digests of the scrapie isoform of the hamster prion protein revealed that the majority of the molecules are glycoinositol phospholipid linked through ethanolamine attached at serin-231. however, approximately 15% of prpsc had a carboxy-terminal peptide that ends at glycine-228. it is intriguing that this glycine is part of the prp sequence gly-arg-arg, which is an established target sequence for the proteolysis and release o ... | 1990 | 1980209 |
| spontaneous neurodegeneration in transgenic mice with mutant prion protein. | transgenic mice were created to assess genetic linkage between gerstmann-sträussler-scheinker syndrome and a leucine substitution at codon 102 of the human prion protein gene. spontaneous neurologic disease with spongiform degeneration and gliosis similar to that in mouse scrapie developed at a mean age of 166 days in 35 mice expressing mouse prion protein with the leucine substitution. thus, many of the clinical and pathological features of gerstmann-sträussler-scheinker syndrome are reproduced ... | 1990 | 1980379 |
| mutation in codon 200 of scrapie amyloid precursor gene linked to creutzfeldt-jakob disease in sephardic jews of libyan and non-libyan origin. | | 1990 | 1975415 |
| genetics of response to slow virus (prion) infection. | | 1990 | 1982401 |
| bovine spongiform encephalopathy: detection and quantitation of fibrils, fibril protein (prp) and vacuolation in brain. | bovine spongiform encephalopathy (bse) is a new disease of cattle which has considerable homology with scrapie, the archetype of the transmissible spongiform encephalopathies. abnormal brain fibrils, called scrapie associated fibrils (saf), are specific ultrastructural markers for these diseases. fibril detection was compared with histopathological diagnosis in the brains of 167 cattle; 157 clinically suspect bse and 10 clinically normal. fibrils were detected in samples of pooled brain regions ... | 1990 | 1976286 |
| nuclease treatment results in high specific purification of creutzfeldt-jakob disease infectivity with a density characteristic of nucleic acid-protein complexes. | representative preparations of partially purified creutzfeldt-jakob disease (cjd), including disaggregated density gradient fractions, were treated with a variety of nucleases. rnases as well as exhaustive digestions with micrococcal nuclease did not significantly diminish infectivity, but resulted in an approximately 7,000-fold specific purification of infectivity with respect to nucleic acid. protected nucleic acids included species of up to 2,000 bases in length. after nuclease treatment, inf ... | 1990 | 1974131 |
| intracellular accumulation of the cellular prion protein after mutagenesis of its asn-linked glycosylation sites. | the cellular isoform of the prion protein (prpc) is a sialoglycoprotein bound almost exclusively on the external surface of the plasma membrane by a glycosyl phosphatidylinositol anchor. the deduced amino acid sequence of syrian hamster prpc identifies two potential sites for the addition of asn-linked carbohydrates at amino acids 181-183 (asn-ile-thr) and 197-199 (asn-phe-thr). we have altered these sites by replacing the threonine residues with alanine and expressed the mutant proteins transie ... | 1990 | 1983782 |
| acceleration of scrapie in trisomy 16----diploid aggregation chimeras. | we studied the susceptibility to prion infection of the trisomy 16----diploid chimeric mouse, a putative model of down syndrome. when weanling chimeras were inoculated intracerebrally with scrapie prions, the time until appearance of the first symptoms of scrapie was reduced by 17 days (from a mean control time of 153 days) and the time to death was reduced by 30 days (from control time of 170 days). our results with trisomy 16 chimeras argue that the susceptibility to central nervous system deg ... | 1991 | 1996884 |
| inhibition of neutrophil functions by scrapie prion protein: description of some inhibitory properties. | the effect of scrapie prion protein (prp) either in the native or in the denatured form was studied on in vitro responses of human neutrophils. incubation of neutrophils with native prp caused an inhibition of their aggregation induced by cytochalasin b. moreover, the denatured form was in itself a strong aggregation inducer. when evaluating the effect on generation of neutrophil superoxide anion (o2) we found that neutrophils released o2 in response to the denatured from only but the native for ... | 1990 | 1983177 |
| molecular biology and genetics of prions--implications for sheep scrapie, "mad cows" and the bse epidemic. historical background. | | 1991 | 2029844 |
| alterations of arginase activity in scrapie-infected mice and in amyotrophic lateral sclerosis. | we followed the dynamics of arginase activity, the ultrastructural changes, and accumulation of the scrapie agent in the cns of scrapie-infected mice. the arginase activity has been shown to increase 5-fold within the first 3-4 months of the incubation period followed by subsequent fall at its end. the peak of increased arginase activity coincided with appearance of multilayer membranes, whereas the decrease of this activity was associated with the greatest development of status spongiosus, syna ... | 1990 | 1983181 |
| workshop on scrapie-related disease control. | | 1991 | 2065368 |
| scrapie in sheep and goats. | | 1990 | 2075694 |