Transmissible spongiform encephalopathies TSEs

This working party considers the aspects of the manufacture and control of biotechnological and biological medicinal products and is also involved in the provision of scientific advice. Workshops on the applieation of assays for markers of transmissible spongiform encephalopathies (TSE) and on the potential risk of transmitting new variant Creutzfeld-Jakob disease (nv-CJD) through plasma-derived medicinal products have recently been held. 

Creutzfeldt-Jacob disease—Human form of transmissible spongiform encephalopathy (TSE), a brain disease in which nerve cells of the brain are destroyed. Seen under a microscope, the brain tissue of people with TSE resembles a sponge. 

Mad cow disease—Bovine spongiform encephalopathy, or BSE, the form of transmissible spongiform encephalopathy (TSE) found in cattle. It is thought to be spread by consumption of brain tissue and caused by proteins called prions. 

Transmissible spongiform encephalopathies (TSEs)—Brain diseases transmitted from one animal to another. Under a microscope, the brain tissue of animals and people with TSEs resembles a sponge. TSEs include variant Creutzfeldt-Jacob disease (vCJD) in humans, scrapie in sheep and goats, and bovine spongiform encephalopathy (BSE) in cows (mad cow disease). These diseases are spread by consumption of brain tissue and are thought to be caused by prions, a kind of protein. 

Currently, there are some concerns regarding Transmissible Spongiform Encephalopathies (TSE) via animal-derived excipients such as gelatin. TSEs are caused by prions that are extremely resistant to heat and normal sterilization processes. TSEs have a very long incubation time with no cure and include diseases such as the following ... 

During the preparation of the bovine bones used in the production of gelatin, specified risk materials that could contain Transmissible Spongiform Encephalopathies (TSEs) vectors are removed. TSE infectivity is not present in... 

In the past, there have been concerns over the transmissible spongiform encephalopathies (TSE) contamination of animal-derived products. However, in the light of current scientific knowledge, and irrespective of geographical origin, milk and milk derivatives are reported as unlikely to present any risk of TSE contamination TSE risk is negligible if the calf rennet is produced in accordance with regulations. ... 

It is important that the full history of the seed is known, including the nature of the culture media used to propagate the strain since isolation. If at all possible, media prepared from animal products should be avoided. If this is not practicable, media components must be from sources certified free of transmissible spongiform encephalopathy (TSE) agents. 

Certain brain diseases of humans and animals known as proteinopathies are associated with the accumulation of misfolded proteins both inside and around neurons [1], Alzheimer s disease in humans is by far the most common member of this group. The prion diseases, exemplified by Creutzfeldt-Jakob disease (CJD) in man, scrapie in small ruminants, and bovine spongiform encephalopathy (BSE) in cattle, constitute a peculiar sub-group within proteinopathies by being experimentally transmissible [2], Because of this feature, together with the sponge-like appearance of vacuoles in affected brain areas, prion diseases are also known as Transmissible Spongiform Encephalopathies (TSEs). 

Der Trab ist auch eine Krankheit der Schaafe, und ist ansteckend. Sie schleppen sich lange, verzehren sich nach und nach, und zuletzt miissen sie sterben. These sentences are taken from an article published in 1759 [1] and describe two hallmarks of prion diseases or transmissible spongiform encephalopathies (TSEs, summarized in Table 1) The formation and transmission of an infectious particle and the invariably fatal course of these diseases. More than 200 years later a landmark discovery paved the way to study the pathogenesis of prion diseases at a molecular level. Prusiner and colleagues reported the identification of a protease-resistant protein in brain extracts, which co-purified with the infectious scrapie agent [18]. After the N-terminal amino acid sequence of the proteinase K (PK)-resistant core of the prion protein (PrP 27-30) was published in 1984 [19], two... 

The odd properties of the infectious agents of the transmissible spongiform encephalopathies (TSE or prion diseases) evoked proposals that they might represent a distinct class of infectious agents (often called prions), which are proteinaceous and devoid of nucleic acid (Griffith, 1967 Prusiner, 1982 Bolton and Bendheim, 1988 Prusiner,... 

The prion protein PrP represents a central player in transmissible spongiform encephalopathies (TSEs), also known as prion diseases (for review see Lasmezas and Weiss, 2000)). The physiological role of the cellular isoform of PrP termed PrP is speculative so far (for review see (Weissmann, 1996)) and might involve control of circadian activity rhythms and sleep (Tobler et ai, 1996), maintenance of cerebellar Purkinje cell (Sakaguchi et al, 1996), and normal synaptic functions (Collinge et al., 1994 Fournier et al., 1995 Kitamoto et al., 1992). Because several reports do not describe any phenotype for PrP (Bueler et al, 1992 Lledo et al, 1996 Manson et al., 1994), the only proved role of prpc is its necessity for the development of TSEs (Bueler et al., 1993)... 

Kozak RW, Golker CF, Stadler P (1996) Transmissible spongiform encephalopathies (TSE) minimizing the risk of transmission by biological/biopharmaceutical products an industry perspective. Dev Biol Stand 88 257-264... 

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