[PSI+] is a prion (infectious protein) of Sup35p, a subunit of the translation termination factor, and [URE3] is a prion of Ure2p, a mediator of nitrogen catabolite repression. Here, we trace the history of these prions and describe the array of anti-prion systems in S. cerevisiae. These systems work together to block prion infection, prion generation, prion propagation, prion segregation, and the lethal (and near-lethal) effects of most variants of these prions. Each system lowers the appearance of prions 2- to 15-fold, but together, ribosome-associated chaperones, the Hsp104 disaggregase, and the Sup35p-binding Upf proteins lower the frequency of [PSI+] appearance by ~5000-fold. [PSI+] variants can be categorized by their sensitivity to the various anti-prion systems, with the majority of prion isolates sensitive to all three of the above-mentioned systems. Yeast prions have been used to screen for human anti-prion proteins, and five of the Bag protein family members each have such activity. We suggest that manipulation of human anti-prion systems may be useful in preventing or treating some of the many human amyloidoses currently found to be prions with the same amyloid architecture as the yeast prions.

This article explores the intriguing case of Kuru disease, a rare and fatal prion disease that once afflicted the Fore people of Papua New Guinea. Scientists are still perplexed as to the origins of Kuru because efforts to discover infectious agents like viruses have been ineffective. Initial research revealed similarities between Kuru and scrapie, a neurological disorder that affects sheep, suggesting potential similarities between the two diseases. In further research, experiments in which chimpanzee brain tissue from Kuru patients was implanted led to the development of Kuru-like symptoms in the animals, suggesting a transmissible component to the condition. Furthermore, data collected from epidemiological studies highlights a drop in Kuru transmission, especially after the Fore people stopped engaging in cannibalism, and the disease showed different incubation times that affected persons within particular age groups. Neuropathological tests in the infected brain tissue have found typical intracellular vacuoles, spongiform alterations, and amyloid plaques. According to studies, Kuru susceptibility has been linked genetically to particular PRNP gene variations. Kuru and other prion disorders have few effective treatments currently, underlining the vital need for early identification. Scientists have created sensitive detection techniques to stop the spread of prion diseases and looked into possible inhibitors. Hypochlorous acid, in particular, has shown potential in cleaning processes. Besides making great progress in understanding Kuru, there are still many unresolved issues surrounding its causes, transmission, and management. The terms "kuru disease," "human prion disease," "transmissible spongiform encephalopathies," and "Creutzfeldt-Jakob syndrome" were used to search the studies; papers unrelated to the review article were removed. Eighty-four articles are included in the review text to fully understand the complexities of this puzzling disease and its conse 2757 cureus Cureus Cureus Cureus Inc. PMC10838565 10838565 10838565 38313950 10.7759/cureus.51708 Kuru Disease: Bridging the Gap Between Prion Biology and Human Health Kothekar Himanshu 1 ✉ Chaudhary Kirti 1 Muacevic Alexander Adler John R 1 Anatomy, Jawaharlal Nehru Medical College, Datta Meghe Institute of Higher Education and Research, Wardha, IND ✉ Himanshu Kothekar hrkothekar@gmail.com ✉ Corresponding author. 5 1 2024 16 1 e51708 e51708 4 2 2024 Copyright © 2024, Kothekar et al. This is an open access article distributed under the terms of the Creative Commons Attribution License CC-BY 4.0., which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Abstract This article explores the intriguing case of Kuru disease, a rare and fatal prion disease that once afflicted the Fore people of Papua New Guinea. Scientists are still perplexed as to the origins of Kuru because efforts to discover infectious agents like viruses have been ineffective. Initial research revealed similarities between Kuru and scrapie, a neurological disorder that affects sheep, suggesting potential similarities between the two diseases. In further research, experiments in which chimpanzee brain tissue from Kuru patients was implanted led to the development of Kuru-like symptoms in the animals, suggesting a transmissible component to the condition. Furthermore, data collected from epidemiological studies highlights a drop in Kuru transmission, especially after the Fore people stopped engaging in cannibalism, and the disease showed different incubation times that affected persons within particular age groups. Besides making great progress in understanding Kuru, there are still many unresolved issues surrounding its causes, transmission, and management. The terms "kuru disease," "human prion disease," "transmissible spongiform Keywords: kuru treatment, creutzfeldt-jakob disease (cjd), transmissible spongiform encephalopathies, human prion disease, kuru disease status released display-pdf yes is-olf no is-manuscript no is-preprint no is-journal-matter no is-scanned no is-retracted no Received 2023 Aug 19; Accepted 2024 Jan 5; Collection date 2024 Jan. In 1955, Zigas learned about Kuru, and two years later, in DC. Gajdusek joined him. In the 2000s, He questioned Gajdusek about the origin of the theory that cannibalism may be used to disseminate Kuru. He stated in reply, "Even a drunken man would think that a disease common to cannibals could only have transmitted through consuming corpses". Gajdusek made this declaration around half a century following the discovery of Kuru. Lindenbaum and Glasse were the first to explicitly publish the theory that Kuru spreads through cannibalism [ 8 ]. Hypochlorous acid is a potentially useful disinfection treatment for hospitals in the fight against prions because it offers no risk to human health [ 84 ]. The treatment and diagnosis of Kuru disease are depicted below in Figure 5 . Figure 5 Treatment and diagnosis of Kuru disease CJD: Creutzfeldt-Jakob disease Conclusions The review looks into Kuru's complex etiology, underlining the difficulties in determining its etiological agents and making fascinating analogies with scrapie, a related neurological condition. Researchers now have a better grasp of the biology of the disease because of neuropathological investigations from past studies that identify unique abnormalities such as intracellular vacuoles, spongiform alterations, and amyloid plaques in the brain tissue of affected people. As a result of the Fore people's cannibalism being forbidden, epidemiological studies highlight a decrease in Kuru transmission. Additionally, the disease's epidemiology is complicated by its varied incubation periods and age-specific symptoms. Further genetic study reveals associations between particular PRNP gene variations and vulnerability to Kuru, illuminating the underlying genetic causes.

SUMMARYMany mammalian diseases appear to be caused primarily by the abnormal accumulation of self-propagating assemblies of specific host proteins such as Aβ and tau in Alzheimer's disease, α-synuclein (aSyn) in Parkinson's disease, and prion protein (PrP) in classical prion diseases. Most proteinopathies involve a prion-like spreading of the aggregates from localized sites of initiation within the host and, sometimes, between individuals. Often, the pathological assemblies take the form of amyloid fibrils, the cores of many of which have been solved by cryo-electron microscopy, revealing disease-specific, strain-like conformers of the given protein. Amyloids grow via seeded polymerization, a mechanism that is being widely exploited to develop ultrasensitive and specific amplification assays for pathological seeds as biomarkers. Such assays can aid fundamental research, diagnostics, prognostics, and clinical trials for multiple proteinopathies that have been challenging to diagnose and treat. Here, we review the structural biology, transmissibilities, spreading mechanisms, and detection of proteopathic aggregates as well as therapeutic approaches to limiting their accumulation.

Prion diseases are invariably fatal neurodegenerative diseases that affect some mammalian species, including humans. These diseases are caused by the misfolding of the cellular prion protein (PrPC) into a pathologic isoform (PrPSc). The prion protein is highly conserved across mammals. However, some species present lower susceptibility to prion diseases than others. This behavior is likely explained by the resistance of these animal species' prion proteins to acquire a pathological conformation. Therefore, the tertiary structure and interspecific variations encoded in the primary structure determine a PrP proneness to misfolding. For this reason, we studied the PRNP gene from a phylogenetic perspective, potentially unveiling evolutionary events related to prion diseases. We generated a database of mammalian PRNP sequences and constructed phylogenetic trees based on nucleotide sequence variations. We aligned 1146 PRNP gene sequences from 901 different mammalian species and built a PRNP gene-based phylogenetic tree. Classical phylogenetic orders tend to maintain their clustering in the PRNP gene tree. Nonetheless, the few differences found may shed some light on potential evolutionary constraints posed by prion disorders. Moreover, this phylogenetic study was combined with an in vitro misfolding study. Protein Misfolding Shaking Amplification (PMSA) was used to evaluate the tendency of many of these proteins to misfold. This comprehensive analysis spanned a wide range of mammalian prion protein sequences and included analysis of different variants with a focus on the human rs1799990 locus (c.385A > G, p.Met129Val). This variant, widely linked to prion disease susceptibility in humans, is explored in the context of its evolutionary origins. All in all, our PRNP gene-based tree, despite showing some topological differences with the reference species tree that could be in some cases related to prion disease susceptibility, is not significantly distinct. Indicating that the proneness of a PrP variant to misfold spontaneously has not shaped the evolution of this gene.

Across taxa, social animals inevitably encounter dying or dead conspecifics and respond in patterned ways, yet the mechanisms underlying these behaviors remain understudied. Bees offer a powerful comparative system for exploring the neuroethology of corpse-directed behaviors. Across the bee phylogeny, sociality has been gained and lost multiple times, resulting in species that range from solitary to highly eusocial. As nesting became increasingly communal, bees evolved diverse corpse-directed behaviors including avoidance, transport and removal, cannibalism, and burial. These behaviors are thought to mitigate pathogen and predation risks, influence resource allocation, and shape colony functioning. In this review, we synthesize findings on corpse-directed behaviors across bee species and social systems. We examine the emerging neurobiological, sensory, endocrine, molecular, and social mechanisms that support corpse detection and behavioral specialization. Lastly, we highlight key gaps in existing research and priorities for future work on the neurobiological and evolutionary foundations of corpse-directed behaviors.

Animal prion diseases are a group of neurodegenerative, transmissible and fatal disorders that affect several animal species. The causative agent called prion, is a misfolded isoform of normal cellular prion protein, which is found constitutively in cells with higher concentration in the central nervous system. In this review, we explored the sources of infection and different natural transmission routes of animal prion diseases in susceptible populations. Chronic wasting disease in cervids and scrapie in small ruminants are prion diseases capable of maintain themselves in susceptible populations through horizontal and vertical transmission. The other prion animal diseases can only be transmitted through food contaminated with prions. Bovine spongiform encephalopathy is the only animal prion disease considered zoonotic, however, due to its inability to transmit within a population, it could be controlled. The emergence of atypical cases of scrapie and bovine spongiform encephalopathy, even the recent report of prion disease in camels, demonstrates the importance to understand the transmission routes of prion diseases in order to take measures to control them and to assess the risks to human and animal health.

Prion diseases (PrDs) are a unique and fatal class of neurodegenerative disorders caused by misfolded proteinaceous infectious particles, or prions. While the pathogenic form was first documented in humans nearly a century ago, the global monitoring of PrDs only gained momentum after the "Mad Cow" epizootic and its human counterpart of the 1980s and 1990s. Currently, 34 countries track human prion cases annually, with over 27,000 cases. However, true prevalence estimates suggest significantly higher numbers, millions, highlighting the urgency of addressing these enigmatic diseases. Prions are exceptionally resilient, resisting conventional sterilization methods and persisting in environmental reservoirs, such as soil and plants, raising concerns about environmental and cross-species transmission, particularly with the growing prevalence of chronic wasting disease (CWD) in cervids. This review explores the history, pathogenesis, presence, public health implications, and novel innovations in studying and treatment of PrDs. Future priorities should include the development of faster, cost-effective diagnostic tools and systemic therapies to neutralize prions in affected individuals and mitigate environmental risks. Understanding and addressing the challenges posed by prions is critical for global health security in the wake of CWD.

A chronic, progressive, fatal central nervous system disease found mainly among the Fore and neighboring peoples of New Guinea, caused by a prion that probably resembles the scrapie agent of sheep, transmissible to nonhuman primates, and believed to be transmitted by ritual cannibalism.: #: #* kuru - Wiktionary, the free dictionary Jump to content From Wiktionary, the free dictionary See also: Kuru , kurů , kůru , kůrů , kūru , and ǁkuru Languages (27) English Ainu •  Ajië •  Bokar •  Czech •  Esperanto •  Fijian •  Finnish •  Guinea-Bissau Creole •  Japanese •  Javanese •  Kwama •  Latvian •  Lower Sorbian •  Māori •  Ngan'gityemerri •  Pitjantjatjara •  Polish •  Portuguese •  Quechua •  Rasawa •  Shona •  Slovak •  Tooro •  Tumbuka •  Turkish •  Yoruba Page categories English [ edit ] English Wikipedia has an article on: kuru (disease) Wikipedia Etymology [ edit ] From Fore kúru ( literally “ trembling, shivering ” ) . [ 1 ] [ 2 ] Perhaps eventually from Proto- Gorokan * kút (V) (“dangling, shaking”) if cognate with the reduplicated element of Yagaria gúli gúli hu- ( “ be loose, rattle ” ) . Pronunciation [ edit ] ( Australia ) IPA ( key ) :  /ˈkʉː.ɹʉː/ ( UK ) IPA ( key ) :  /ˈkʊ.ɹuː/ Audio ( Southern England ) : ( file ) Rhymes: ( UK ) -ʊɹu Noun [ edit ] kuru ( uncountable ) A chronic , progressive , fatal central nervous system disease found mainly among the Fore and neighboring peoples of New Guinea , caused by a prion that probably resembles the scrapie agent of sheep, transmissible to nonhuman primates, and believed to be transmitted by ritual cannibalism . Synonyms: laughing death , laughing sickness , Kuru disease 1999 , Matt Ridley , Genome , Harper Perennial, published 2004 , page 273 : By the late 1950s, kuru was the leading cause of death among Fore women, and it had killed so many that men outnumbered women by three to one. Translations [ edit ] central nervous system disease Chinese: Mandarin: 庫魯病  / 库鲁病 ( kùlǔbìng ) Esperanto: kuruo Finnish: kuru   (fi) French: kuru   (fr)   m German: Kuru   f Irish: kuru   m Portuguese: kuru   (pt)   m Russian: ку́ру   (ru)   f ( kúru ) References [ edit ] ^ Scott, Graham ( 1978 ), The Fore Language of Papua New Guinea , Pacific Linguistics, →DOI , →ISBN , pages 2, 6 ^ Zigas, V.; Gajdusek, D. C. Noun [ edit ] kuru definite accusative singular of kur Yoruba [ edit ] Etymology [ edit ] Possibly related to kūrū̀ Pronunciation [ edit ] IPA ( key ) :  /kú.ɾú/ Verb [ edit ] kúrú to be short Antonym: ga Derived terms [ edit ] kúkurú Retrieved from " https://en.wiktionary.org/w/index.php?title=kuru&oldid=91450788 " Categories : English terms borrowed from Fore English terms derived from Fore English 2-syllable words English terms with IPA pronunciation English terms with audio pronunciation Rhymes:English/ʊɹu Rhymes:English/ʊɹu/2 syllables English lemmas English nouns English uncountable nouns English terms with quotations en:Diseases Ainu terms with IPA pronunciation Ainu lemmas Ainu nouns Ajië lemmas Ajië verbs Bokar lemmas Bokar nouns Czech terms with IPA pronunciation Czech non-lemma forms Czech noun forms Esperanto 2-syllable words Esperanto terms with IPA pronunciation Esperanto terms with audio pronunciation Rhymes:Esperanto/uru Rhymes:Esperanto/uru/2 syllables Esperanto non-lemma forms Esperanto verb forms Fijian terms inherited from Proto-Oceanic Fijian terms derived from Proto-Oceanic Fijian terms inherited from Proto-Eastern Malayo-Polynesian Fijian terms derived from Proto-Eastern Malayo-Polynesian Fijian terms inherited from Proto-Central-Eastern Malayo-Polynesian Fijian terms derived from Proto-Central-Eastern Malayo-Polynesian Fijian terms inherited from Proto-Malayo-Polynesian Fijian terms derived from Proto-Malayo-Polynesian Fijian terms with IPA pronunciation Fijian lemmas Fijian verbs fj:Weather Fijian terms with usage examples Fijian nouns fj:Atmospheric phenomena fj:Sounds Finnish 2-syllable words Finnish terms with IPA pronunciation Rhymes:Finnish/uru Rhymes:Finnish/uru/2 syllables Finnish terms inherited from Proto-Finnic Finnish terms derived from Proto-Finnic Finnish terms derived from Proto-Finno-Ugric Finnish lemmas Finnish nouns fi:Geography Finnish valo-type nominals Finnish terms derived from English Finnish terms derived from Fore fi:Diseases Finnish uncountable nouns Guinea-Bissau Creole terms derived from Portuguese Guinea-Bissau Creole lemmas Guinea-Bissau Creole nouns Japanese non-lemma forms Japanese romanizations Javanese lemmas Javanese adjectives Kwama lemmas Kwama nouns Latvian non-lemma forms Latvian pronoun forms Latvian verb forms Lower Sorbian terms with IPA pronunciation Lower Sorbian non-lemma forms Lower Sorbian noun forms Māori terms with IPA pronunciation Māori terms inherited from Proto-Polynesian Māori terms derived from Proto-Polynesian Māori terms inherited from Proto-Oceanic Māori terms derived from Proto-Oceanic Māori terms inherited from Proto-Eastern Malayo-Polynesian Māori terms derived from Proto-Eastern Malayo-Polynesian Māori terms inherited from Proto-Central-Eastern Malayo-Polynesian Māori terms derived from Proto-Central-Eastern Malayo-Polynesian Māori terms inherited from Proto-Malayo-Polynesian Māori terms derived from Proto-Malayo-Polynesian Māori lemmas Māori nouns Māori terms with usage examples Māori terms inherited from Proto-Nuclear Polynesian Māori terms derived from Proto-Nuclear Polynesian Māori verbs mi:Mulberry family plants mi:Polynesian canoe plants mi:Tools Ngan'gityemerri lemmas Ngan'gityemerri nouns Pitjantjatjara lemmas Pitjantjatjara nouns Polish 2-syllable words Polish terms with IPA pronunciation Polish terms with audio pronunciation Rhymes:Polish/uru Rhymes:Polish/uru/2 syllables Polish non-lemma forms Polish noun forms Portuguese terms

By the end of this section, you will be able to do the following: Prions and viroids are pathogens (agents with the ability to cause disease) that have simpler structures than viruses but, in the case of prions, still can produce deadly diseases. Prions, so-called because they are proteinaceous, are infectious particles—smaller than viruses—that contain no nucleic acids (neither DNA nor RNA). Historically, the idea of an infectious agent that did not use nucleic acids was considered impossible, but pioneering work by Nobel Prize-winning biologist Stanley Prusiner has convinced the majority of biologists that such agents do indeed exist. Fatal neurodegenerative diseases, such as kuru in humans and bovine spongiform encephalopathy (BSE) in cattle (commonly known as “mad cow disease”) were shown to be transmitted by prions. The disease was spread by the consumption of meat, nervous tissue, or internal organs between members of the same species. Kuru, native to humans in Papua New Guinea, was spread from human to human via ritualistic cannibalism.

Other research by Stanley Prusiner and others led to the finding of proteins called prions that caused these disease and other similar diseases. Some people in the medical community, do not think that cannibalism was still practiced when Gajdusek did his research. Willam Arens, an anthropologist, says that Gajdusek never saw cannibalism himself.[3] Researchers who worked with the Fore in the 1950s say that cannibalism was stopped in 1948.[4] This was almost a decade before Gajdusek went to New Guinea. Many other researchers, including Robert Klitzman, S. Lindenbaum, R. Glasse, and researchers at the Papua New Guinea Institute of Medical Research have made reports that say that the cannibalism still happened. Gajdusek became head of the laboratories for virological and neurological research at the National Institutes of Health (NIH) in 1958. He was made a part of the National Academy of Sciences in 1974. Child molestation conviction During his trips in the South Pacific, Gajdusek had brought 56 children back to live with him in the United States. He gave them the chance to have high school and college education.

In many parasite-vector systems, alterations of the behaviour of the blood-sucking arthropods result in an increase of the transmission rate, but the underlying mechanisms are elucidated in only some systems. The more sluggish movements of the Trypanosoma rangeli-infected triatomine Rhodnius prolixus might increase the rate of predation by insectivorous mammals but also the transmission rate between the triatomines via cannibalism. Alterations of the feeding behaviour by which the number of attacks on hosts by blood-sucking arthropods can be increased seem to derive from two possible mechanisms. A competition for metabolites in the ingested blood induces an earlier starvation effect than in non-infected specimens and thus a new attempt by the insect to ingest blood. This may be relevant in T. cruzi-infected triatomines. Perhaps this is also the reason for the increased activity of ticks infected with the tick-borne encephalitis virus, resulting in a higher infection rate of ticks collected on humans than from the vegetation. The second, better elucidated mechanism is interference with the ingestion process, which causes a higher number of probings and low ingestion rates and is connected with disturbances of the digestive tract. Cells of the salivary glands are destroyed by the penetration of the parasites in Plasmodium-infected mosquitoes, T. rangeli-infected Rhodnius, and tsetse flies infected with salivarian Trypanosoma species. Some of the latter species attach to mechanoreceptive sensilla, which act as fluid flow meters and/or reduce the diameter of the foregut by a heavy colonization. This colonization effect is even more evident in several Leishmania-sandfly systems and in Yersinia pestis infection of the rat flea.

Prions(proteinaceous infectious particles) are responsible to subacute spongiform encephalopathies(SSE) in man and animals. Recent outbreak of bovine SSE(BSE), or mad cow disease in UK provoked concerns on its possible human hazards. A statement of the British Government in March 1996 upset the world, which was based on 10 cases of "new variant" form of Creutzfelds-Jakob disease(CJD). Prion diseases in animals are often epizootic and may be spread to different species through various routes including ingestion of contaminated meats. It is possible that mad cow disease cause a CJD-like malady in man through a dietary route. Human SSE include; 1) Classical CJD, which represents over 95% of the cases with SSE, dispersely sporadic in occurrence in 1 per million a year, with monotonously rising incidence rates with age, of which the origin of the prion is totally unknown. 2) Gerstmann-Sträusseler Scheinker's disease which is inherited dominantly due to various genetic variants of the prion. 3) Transmitted cases of CJD occurring due to the prion introduced through contaminated objects either directly to the brain or its coverings, or indirectly to the brain through peripheral organs. 4) Kuru occurring among the Fore people in Papua New Guinea, probably due to the prion spread by a dietary route in cannibalism. New variant CJD(vCJD) now totals 14 cases all observed in UK and is different from all of four, is encountered in a dispersely sporadic manner, is far younger at onset than classical cases, showing kuru-plaques. Prions from vCJD have physical-chemical properties similar to those the BSE. Countermeasures in Japan against human hazards of BSE include, 1) agent controls by means of quarantine and 2) host controls. Sofar no vCJD-like case is observed in Japan. An emergent surveillance for CJD was introduced by the Ministry of Health and Welfare in July 1996. It obtained a total of 2,637 answers form 4,027 departments of neurology, psychiatry, etc throughout the country and identified 766 cases including 51 familial cases, but no case with vCJD.

Prions (proteinaceous infectious particles) are responsible to subacute spongiform encephalopathies (SSE) in man and animals. Recent outbreak of bovine SSE (BSE), or mad cow disease in UK provoked concerns on its possible human hazards. A statement of the British Government in March 1996 upset the world, which was based on 10 cases of "new variant" form of Creutzfeldt-Jakob disease (CJD). Prion diseases in animals are often epizootic and may be spread to different species through various routes including ingestion of contaminated meats. It is possible that mad cow disease causes a CJD-like malady in man through a dietary route. human SSE include; 1) Classical CJD, which represents over 95% of the cases with SSE, dispersely sporadic in occurrence in 1 per million a year, with monotonously rising incidence rates with age, of which the origin of the prion is totally unknown. 2) Gerstmann-Sträussler-Scheinker's disease which is inherited dominantly due to various genetic variants of the prion. 3) Transmitted cases of CJD occurring due to the prion introduced through contaminated objects either directly to the brain or its coverings, or indirectly to the brain through peripheral organs. 4) Kuru occurring among the Fore people in Papua New Guinea, probably due to the prion spread by a dietary route in cannibalism. New variant CJD (vCJD) now totals 14 cases all observed in UK and is different from all of four, is encountered in a dispersely sporadic manner, is far younger at onset than classical cases, showing kuru-plaques. Prions from vCJD have physical-chemical properties similar to those from BSE. Countermeasures in Japan against human hazards of BSE include, 1) agent controls by means of quarantine, and 2) host controls. So far no vCJD-like case is observed in Japan. An emergent surveillance for CJD was introduced by the Ministry of Health and Welfare in July 1996. It obtained a total of 2,637 answers from 4,027 departments of neurology, psychiatry, etc throughout the country and identified 766 cases including 51 familial cases, but no case with vCJD.

The causal link of a new variant of CJD (v-CJD) with bovine spongiform encephalopathy (BSE) has led to world-wide panic. BSE emerged in 1986 through dietary products contaminated with scrapie pathogen, BSE case reports increased in number up to 37,000/year in 1993, then declined in 1994 when the first case of v-CJD emerged. There is a 3-year gap between the emergence of BSE and the introduction of a ban on the use of specified bovine offal in human food. People might have consumed dietary products contaminated with BSE pathogen for the period. Species barrier which has protected human from being transmitted with sheep scrapie pathogen might not work so well in cow-to-human transmission as in sheep-to-human. There are familial forms and sporadic forms of human prion diseases. The familial prion diseases are always related to prion protein (PrP) gene mutations. Sporadic forms of prion diseases are composed of sporadic CJD, iatrogenic CJD and kuru. Sporadic CJD occurs in elder people and shows cortical signs and periodic synchronous discharges (PSD) in short clinical course and pathologically spongiform degeneration and abnormal PrP deposition in synapse structures, but no amyloid plaque deposition in the brain is observed. Since the v-CJD patients had no mutations in PrP gene, v-CJD belongs to sporadic forms of prion diseases. v-CJD shows quite different clinicopathological features from those of sporadic CJD, rather shows similar features to iatrogenic CJD of pituitary hormone and kuru. These three diseases share several features, which are younger patient age, main clinical manifestation of cerebellar signs, negative or rare record of PSD, and PrP amyloid plaque deposition in the brain. The patients of v-CJD, however, had no history of exposure to iatrogenic factors and of cannibalism. Also they did not have a valine polymorphism at PrP codon 129 which is frequently observed in the patients with iatrogenic CJD and kuru. Thus, v-CJD is a quite novel entity in human prion diseases.