S: SDir – http://bit.do/eAveF (last access: 11 November 2018); MedicineNet.com – http://bit.do/eAveM (last access: 11 November 2018).
N: 1. – transmissible (adj): 1640s, from Latin transmiss-, stem of transmittere “send across, carry over” + –ible word-forming element making adjectives from verbs, borrowed in Middle English from Old French ible and directly from Latin adjective suffix –ibilis (properly –bilis).
– spongiform (adj): 1774, “resembling a sponge” from Latin spongia “sponge” + forma “form, shape”.
– encephalopathy (n): From “encephalo-“, before vowels encephal-, word-forming element meaning “brain, of the brain,” from combining form of medical Latin encephalon, from Greek enkephalos “the brain,” literally “within the head,” from en “in” + kephale “head;” + “-pathy” word-forming element meaning “feeling, suffering, emotion; disorder, disease,” from Latin -pathia, from Greek -patheia “act of suffering, feeling”.
- Abbreviation in use for “transmissible spongiform encephalopathy”: TSE.
- Frequent in plural: transmissible spongiform encephalopathies.
2. Transmissible spongiform encephalopathies are a number of progressive neurodegenerative disorders in animals and humans caused by “prions” a word that is derived from “proteinaceous o infectious particle”. These diseases are transmissible because they are capable of being transferred from one animal to another, spongiform because they cause the appearance of sponge-like holes in the brain of those affected, and encephalopathic because they are neurodegenerative diseases of the brain. Although these infections usually remain asymptomatic for years, the disease is always progressive and fatal once the clinical signs develop.
3. TSEs are thought to be acquired primarily by ingestion, although some prions may also enter the body by other routes. Prions occur mainly in the central nervous system (CNS) of TSE-infected animals, but they can also be found in lymphoid tissues, peripheral nerves and various organs, to a greater or lesser extent depending on the prion and host species. Studies of the scrapie agent and more limited studies of prions of human origin indicate that the agents are resistant to treatments that inactivate nucleic acids and viruses (alcohol, formalin, ionizing radiation, proteases, and nucleases) but that they are inactivated by treatments that disrupt proteins (autoclaving, phenol, detergents, and extremes of pH). Prusiner showed that infectivity colocalized with a protein and proposed the term prion “to denote a small proteinaceous infectious particle which is resistant to most procedures that modify nucleic acids”. The protease-resistant protein associated with disease (designated PrPres or PRPSc) proved to be an isoform of a protease-sensitive normal host cellular protein (designated PrPres or PrPC). In the pathologic process, PrPsen undergoes a post-translational conformational change to PrPres; this conformational change converts the protein from a predominantly alpha-helical structure into one with a large beta-sheet content. This protease-resistant isoform accumulates in neural cells, disrupting function and leading to vacuolization and cell death. Studies in transgenic mice indicate that mutations in the gene coding for PrP or overexpression of the gene can lead to spongiform changes. Mice lacking the PrP gene cannot be infected with scrapie, an observation unequivocally showing that PrP is necessary for the disease. Whether PrP is sufficient is unclear.
4. Cultural Interrelation: Kuru is a transmissible spongiform encephalopathy that became epidemic among the Fore and surrounding linguistic groups in Papua New Guinea, peaking in the late 1950s. It was transmitted during the transumption (endocannibalism) of dead family members at mortuary feasts. The transumption has long been stopped.
S: 1. OED – https://goo.gl/Z5vBAE, https://goo.gl/XNujw8, https://goo.gl/yx5Kkj (last access: 6 November 2018); MW- https://goo.gl/wwzd6y (last access: 6 November 2018); CFSPH – https://goo.gl/XBwfhR (last access: 6 November 2018). 2. IFT – https://goo.gl/u7UeFA (last access: 6 November 2018); CFSPH – https://goo.gl/RXJhY4 (last access: 6 November 2018). 3. CFSPH – https://goo.gl/XBwfhR (last access: 6 November 2018); NEJM – https://goo.gl/PwYA5H (last access: 6 November 2018). 4. UCL – https://goo.gl/q6ZNxG (last access: 6 November 2018).
SYN: transmissible subacute spongiform encephalopathy, TSSE, TSE, prion disease, subacute transmissible spongiform encephalopathy, subacute spongiform encephalopathy.
S: GDT – http://bit.do/eAvo9 (last access: 11 November 2018)
CR: bovine spongiform encephalopathy, Creutzfeldt-Jakob disease.