Transmissible spongiform encephalopathies(TSEs)are a group of progressive and ultimately fatal neurologic diseases of man and animals,all resulting from the propagated misfolding of the host's normal cellular prio...Transmissible spongiform encephalopathies(TSEs)are a group of progressive and ultimately fatal neurologic diseases of man and animals,all resulting from the propagated misfolding of the host's normal cellular prion protein.These diseases can be spontaneous,heritable,anthropogenic/iatrogenic,or in some cases horizontally transmissible,and include such notable TSEs as bovine spongiform encephalopathy(BSE)of cattle and chronic wasting disease(CWD)of cervids.Although they are both unequivocally protein misfolding disorders,they differ markedly in their pathogenesis,transmissibility,and zoonotic potential.While the BSE epidemic has largely abated over the past three decades following global feed bans on ruminant meat and bone meal,CWD,which is readily transmitted through various forms of excreta,has rapidly expanded from its original endemic zone to encompass much of North America,along with recently identified foci in Scandinavia.Most importantly,although the classical form of BSE has proven transmissible to humans consuming contaminated beef or beef products,so far there have been no conclusive reports on the zoonotic transmission of cWD to humans.The underlying basis for these differences-whether host or agent directed-are not well understood,though may be due to inherent differences in the three-dimensional structure of the misfolded BSE or CWD prion proteins or the expression levels and tissue distribution of respective cellular prion proteins.With the uncontrolled geographic spread of CWD,it is imperative that we improve our understanding of the factors governing prion disease pathogenesis,transmission,and zoonotic potential.展开更多
Transmissible spongiform encephalopathies （TSEs）, also known as prion diseases, are a group of fatal neurodegenerative diseases detected in a wide range of mammalian species. The ＂protein-only＂ hypothesis of TSE s...Transmissible spongiform encephalopathies （TSEs）, also known as prion diseases, are a group of fatal neurodegenerative diseases detected in a wide range of mammalian species. The ＂protein-only＂ hypothesis of TSE suggests that prions are transmissible particles devoid of nucleic acid and the primary pathogenic event is thought to be the conversion of cellular prion protein （PrPc） into the disease-associated isoform （prpSc）. According to susceptibility to TSEs, animals can be classified into susceptible species and low susceptibility species. In this review we focus on several species with low susceptibility to TSEs： dogs, rabbits, horses and buffaloes. We summarize recent studies into the characteristics of low susceptibility regarding protein structure, and biochemical and genetic properties.展开更多
This paper examines the U.S. meat demand impacts of the announced outbreaks of bovine spongiform encephalopathy（BSE） and avian influenza（AI）. Findings indicate that beef and chicken demand was negatively affected ...This paper examines the U.S. meat demand impacts of the announced outbreaks of bovine spongiform encephalopathy（BSE） and avian influenza（AI）. Findings indicate that beef and chicken demand was negatively affected by BSE and AI disease outbreaks. Specifically, in the short run, U.S. consumers shift demand due to both outbreaks but more so due to domestic disease outbreaks than for outbreaks occurring overseas-the impact of U.S. AI outbreaks is about 0.5% for beef and the impact of U.S. BSE cases is around –0.42% for beef and 0.4% for pork, respectively. Regarding the BSE shock on meat demand, there is a high rate of beef demand adjusted from disturbance to the long-run equilibrium and a lower adjustment rate for chicken demand because of the repeated outbreaks of AI worldwide. In the long run, information related to severe, persistently recurring overseas animal disease outbreaks changes U.S. consumers＇ meat consumption patterns. Although effects of animal diseases on U.S. meat demand were statistically significant, the magnitudes were small-the impact of WHO reported human death numbers for AI is 0.005% for beef, –0.002% for pork, and –0.006% for chicken and the impact of U.S. BSE cases is 1.1% for pork and –0.7% for chicken.展开更多
The rapid detection of infectivity of several agents that cause Creutzfeldt-Jakob disease has previously been achieved by assaying for deposits of abnormal prion protein (PrPSc) in follicular dendritic cells in the sp...The rapid detection of infectivity of several agents that cause Creutzfeldt-Jakob disease has previously been achieved by assaying for deposits of abnormal prion protein (PrPSc) in follicular dendritic cells in the spleens of transgenic mice carrying the human prion protein gene. In this study, transgenic mice expressing the bovine prion protein were inoculated intraperitoneally with classical (C-type) or atypical L-type bovine spongiform encephalopathies (BSE). Proteinase-resistant PrPSc were detected in the spleens of all transgenic mice at 75 days after inoculation with both types of BSE. Infectivity in PrPSc-positive spleens of the transgenic mice revealed that prions of C- and L-type BSE replicated. These results suggest that bioassay system by the transgenic mice could be useful for the rapid detection of BSE infectivity with discriminating between C- and L-type BSEs.展开更多
Objective: To study the CT and MR imaging features of spongiform leukoencephalopathy after heroin vapor inhalation. Method,: The CT and MR imaging features and pathologic findings of 13 patients with heroin-induced sp...Objective: To study the CT and MR imaging features of spongiform leukoencephalopathy after heroin vapor inhalation. Method,: The CT and MR imaging features and pathologic findings of 13 patients with heroin-induced spongiform leukoencephalopathy were analyzed. Results: CT scanning and MRI of all the patients showed diffuse, symmetric lesion in the cerebellar and cerebral white matter, and the cerebellum was invariably involved in all cases. Symmetric round or butterfly-like lesions lateral to the midline of the cerebellum with clear border was the most distinct feature in CT and MRI examination. The lesions were not found in the anterior limbs of the internal capsules. CT scanning showed low-density changes while MRI TIWI imaging presented low-signal and T2WI high-signal lesions without space-occupying mass. The pathologic findings showed spongiform degeneration of the white matter in the central nervous system, but necrotic lesions were not observed. Conclusions: Spongiform leukoencephalopathy should be considered when acute. cerebellar signs are present in patients who admitted a history of heroin inhalation. The CT and MRI manifestation of this disease is typical and the diagnosis can thus be made.展开更多
Owing to the high oxygen-respiration in the brain of mammals, oxidative damage to prion protein hasbeen suggested to be an additional factor. A large body of intriguing features of scrapie and prion diseases haveprovi...Owing to the high oxygen-respiration in the brain of mammals, oxidative damage to prion protein hasbeen suggested to be an additional factor. A large body of intriguing features of scrapie and prion diseases haveprovided multiple lines of indirect chemistry evidence, suggesting that the infectious agents may be putative forms ofsequence-specific prion radicals (SSPR) and/or their immediate precursors in the transmissible spongiform encepha-lopathies (TSE). Here a molecular mechanism corresponding to the self-replication of scrapie protein mediated byprion free-radical processes, consonant with "protein-only" hypotheses is proposed. This new theory may not onlyaid our understanding of the occurrence of prions, but also provides new insight into the possible chemistry principlesunderlying the neurodegenerative disorders. It is anticipated that future studies based on this suggestion and chem-istry principles of genetic diseases may allow us to determine an effective approach to stop mad cow disease and itshuman version, new variant of Creutzfeldt-Jakob disease (v CJD).展开更多
Objective To elucidate the imaging characteristics of spongiform leukoencephalopathy induced by heroin and the diagnostic value of MRI examination.Methods Eleven cases of heroin addiction were examined by MRI.The sequ...Objective To elucidate the imaging characteristics of spongiform leukoencephalopathy induced by heroin and the diagnostic value of MRI examination.Methods Eleven cases of heroin addiction were examined by MRI.The sequences included T1-weighted imaging(T1WI),T2-weighted imaging(T2WI)and fast fluid-attenuated inversion recovery pulse sequence(Flair).Results Bilateral symmetrical lesions were located in the white matter of the cerebrum and cerebellum,the internal capsule in all cases,and the callosum in 6 cases.Elliptical lesions in the mesencephalon were found in two cases.These lesions were shown as hypointense signals on T1WI and hyperintense signals on T2WI and Flair's imaging.Cerebellar white matter suffered more severely,but the dentate nuclei were not invaded.Conclusion Heroin-induced spongiform leukoencephalopathy has characteristic patterns in MRI,which are very specific to this form of the disease.展开更多
基金funded in part by the Center on Emerging and Zoonotic Infectious Diseases(CEZID)of the National Institutes of General Medical Sciences underaward number P20GM130448.
文摘Transmissible spongiform encephalopathies(TSEs)are a group of progressive and ultimately fatal neurologic diseases of man and animals,all resulting from the propagated misfolding of the host's normal cellular prion protein.These diseases can be spontaneous,heritable,anthropogenic/iatrogenic,or in some cases horizontally transmissible,and include such notable TSEs as bovine spongiform encephalopathy(BSE)of cattle and chronic wasting disease(CWD)of cervids.Although they are both unequivocally protein misfolding disorders,they differ markedly in their pathogenesis,transmissibility,and zoonotic potential.While the BSE epidemic has largely abated over the past three decades following global feed bans on ruminant meat and bone meal,CWD,which is readily transmitted through various forms of excreta,has rapidly expanded from its original endemic zone to encompass much of North America,along with recently identified foci in Scandinavia.Most importantly,although the classical form of BSE has proven transmissible to humans consuming contaminated beef or beef products,so far there have been no conclusive reports on the zoonotic transmission of cWD to humans.The underlying basis for these differences-whether host or agent directed-are not well understood,though may be due to inherent differences in the three-dimensional structure of the misfolded BSE or CWD prion proteins or the expression levels and tissue distribution of respective cellular prion proteins.With the uncontrolled geographic spread of CWD,it is imperative that we improve our understanding of the factors governing prion disease pathogenesis,transmission,and zoonotic potential.
基金supported by the National Natural Science Foundation of China(31060302 and 31260032)the Transgene Special Project of the Ministry of Agriculture of China(2011ZX08009-003-006)the Natural Science Foundation of Yunnan Province(2010CD010)
文摘Transmissible spongiform encephalopathies （TSEs）, also known as prion diseases, are a group of fatal neurodegenerative diseases detected in a wide range of mammalian species. The ＂protein-only＂ hypothesis of TSE suggests that prions are transmissible particles devoid of nucleic acid and the primary pathogenic event is thought to be the conversion of cellular prion protein （PrPc） into the disease-associated isoform （prpSc）. According to susceptibility to TSEs, animals can be classified into susceptible species and low susceptibility species. In this review we focus on several species with low susceptibility to TSEs： dogs, rabbits, horses and buffaloes. We summarize recent studies into the characteristics of low susceptibility regarding protein structure, and biochemical and genetic properties.
文摘This paper examines the U.S. meat demand impacts of the announced outbreaks of bovine spongiform encephalopathy（BSE） and avian influenza（AI）. Findings indicate that beef and chicken demand was negatively affected by BSE and AI disease outbreaks. Specifically, in the short run, U.S. consumers shift demand due to both outbreaks but more so due to domestic disease outbreaks than for outbreaks occurring overseas-the impact of U.S. AI outbreaks is about 0.5% for beef and the impact of U.S. BSE cases is around –0.42% for beef and 0.4% for pork, respectively. Regarding the BSE shock on meat demand, there is a high rate of beef demand adjusted from disturbance to the long-run equilibrium and a lower adjustment rate for chicken demand because of the repeated outbreaks of AI worldwide. In the long run, information related to severe, persistently recurring overseas animal disease outbreaks changes U.S. consumers＇ meat consumption patterns. Although effects of animal diseases on U.S. meat demand were statistically significant, the magnitudes were small-the impact of WHO reported human death numbers for AI is 0.005% for beef, –0.002% for pork, and –0.006% for chicken and the impact of U.S. BSE cases is 1.1% for pork and –0.7% for chicken.
文摘The rapid detection of infectivity of several agents that cause Creutzfeldt-Jakob disease has previously been achieved by assaying for deposits of abnormal prion protein (PrPSc) in follicular dendritic cells in the spleens of transgenic mice carrying the human prion protein gene. In this study, transgenic mice expressing the bovine prion protein were inoculated intraperitoneally with classical (C-type) or atypical L-type bovine spongiform encephalopathies (BSE). Proteinase-resistant PrPSc were detected in the spleens of all transgenic mice at 75 days after inoculation with both types of BSE. Infectivity in PrPSc-positive spleens of the transgenic mice revealed that prions of C- and L-type BSE replicated. These results suggest that bioassay system by the transgenic mice could be useful for the rapid detection of BSE infectivity with discriminating between C- and L-type BSEs.
文摘Objective: To study the CT and MR imaging features of spongiform leukoencephalopathy after heroin vapor inhalation. Method,: The CT and MR imaging features and pathologic findings of 13 patients with heroin-induced spongiform leukoencephalopathy were analyzed. Results: CT scanning and MRI of all the patients showed diffuse, symmetric lesion in the cerebellar and cerebral white matter, and the cerebellum was invariably involved in all cases. Symmetric round or butterfly-like lesions lateral to the midline of the cerebellum with clear border was the most distinct feature in CT and MRI examination. The lesions were not found in the anterior limbs of the internal capsules. CT scanning showed low-density changes while MRI TIWI imaging presented low-signal and T2WI high-signal lesions without space-occupying mass. The pathologic findings showed spongiform degeneration of the white matter in the central nervous system, but necrotic lesions were not observed. Conclusions: Spongiform leukoencephalopathy should be considered when acute. cerebellar signs are present in patients who admitted a history of heroin inhalation. The CT and MRI manifestation of this disease is typical and the diagnosis can thus be made.
基金Supported partly by the National Natural Science Foundation of China(No.20042002)and the Ministry of Science and Technology of China
文摘Owing to the high oxygen-respiration in the brain of mammals, oxidative damage to prion protein hasbeen suggested to be an additional factor. A large body of intriguing features of scrapie and prion diseases haveprovided multiple lines of indirect chemistry evidence, suggesting that the infectious agents may be putative forms ofsequence-specific prion radicals (SSPR) and/or their immediate precursors in the transmissible spongiform encepha-lopathies (TSE). Here a molecular mechanism corresponding to the self-replication of scrapie protein mediated byprion free-radical processes, consonant with "protein-only" hypotheses is proposed. This new theory may not onlyaid our understanding of the occurrence of prions, but also provides new insight into the possible chemistry principlesunderlying the neurodegenerative disorders. It is anticipated that future studies based on this suggestion and chem-istry principles of genetic diseases may allow us to determine an effective approach to stop mad cow disease and itshuman version, new variant of Creutzfeldt-Jakob disease (v CJD).
文摘Objective To elucidate the imaging characteristics of spongiform leukoencephalopathy induced by heroin and the diagnostic value of MRI examination.Methods Eleven cases of heroin addiction were examined by MRI.The sequences included T1-weighted imaging(T1WI),T2-weighted imaging(T2WI)and fast fluid-attenuated inversion recovery pulse sequence(Flair).Results Bilateral symmetrical lesions were located in the white matter of the cerebrum and cerebellum,the internal capsule in all cases,and the callosum in 6 cases.Elliptical lesions in the mesencephalon were found in two cases.These lesions were shown as hypointense signals on T1WI and hyperintense signals on T2WI and Flair's imaging.Cerebellar white matter suffered more severely,but the dentate nuclei were not invaded.Conclusion Heroin-induced spongiform leukoencephalopathy has characteristic patterns in MRI,which are very specific to this form of the disease.
