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Glossary of TSE Related Scientific Terms


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Agent - the infectious element of a disease responsible for its transmission between cells, and from animal to animal. Usually recognisable as a virus or bacteria in other known diseases, but so far no such agent has been detected for TSE's and the theory is that a rogue protein, or Prion is responsible.
Alpha Helix - The spiraled twist that is thought to be the shape of the protein back-bone of a normal PrPc. It is thought that four arranged together make up the central structure.
Ataxia - the loss of coordination that an animal or human suffers due to neurological damage, a symptom of many wasting diseases of the brain and nerves.



Beta Sheet - A robust protein sheet formed in the PrPsc Prion by the joining up of a number of Beta Strands, providing a very robust structure for the Prion and making it nearly indestructible.
Beta Strand - The straight protein back-bone structure that is thought to be at the centre of PrPsc the mutated form of the natural PrPc protein.
Bioassay - The inoculation of tissues from one animal into the body of another. It is used to see (i)if the tissue carries the infective agent of a disease, or (ii)to see if the animal that is being inoculated is susceptible to the disease.
BSE - Bovine Spongiform Encephalopathy, the form of TSE found in cattle, also known as 'Mad cow disease'. For a more in-depth explanation of BSE see the 2nd half of this project.


Cellular culture - the practice of 'growing' individual or small groups of cells in a test tube. Could in future be used to grow cells and infect them with TSE's in order to develop and test drugs for their treatment.
CJD - Creutzfeld-Jakob disease, the most common of a small number of human TSE's, although still quite rare, it usually affects people in their old age, sixties and seventies. A new variation of it has been linked with BSE through a similarity in the Prion make-up and molecular signature (CJD2).


Electrophoresis - The method of separating and sorting proteins by drawing them through a fine gel using an electrical current, allowing them to be identified.


FSE - Feline Spongiform Encephalopathy - a TSE that appeared in 1990 and affects domestic cats. It is thought it occurred due to BSE infection in cat food.


Glycan - a chain of sugar molecules that is often used to distinguish between different variations of a protein (glycoform).
Glycoform - a classification of a protein by the glycan chains that are attached to it.
Glycoprotein - A protein that carries attached to it a number of glycans. The PrP protein has two such chains attached, and it is thought it is the difference in the glycan's make-up that separates the different strains of TSEs.


Horizontal transmission - see Lateral transmission.


Immunohistochemistry - the testing of samples of tissue from an animal for specific proteins by attaching specific antibodies to them, and then marking these antibodies with enzymes to which they are connected.
Immunolabeling - similar to Immunohistochemistry, except using a labeling substance other than an enzyme to mark out the antibodies.
Infective range - the range of species that a disease can infect.
Infective unit - IU - the minimal dosage of a TSE that is needed to transmit the disease from one animal to another of the same species.
Inoculate - to introduce a disease's infective agent into the body of another animal, either to study the effects of the disease, to see how effective it is in crossing the species barrier, or to produce antibodies against the disease by inoculating the patient with a deactivated version of the agent.
Inter-cerebral inoculation - inoculation of a substance directly into the brain of a subject by injection through the skull.


Kuru - a form of TSE that appeared in Papua New Guinea in the first half of this century. It was eventually found to be due to a practice of ritual cannibalism where dead tribal members were eaten as a mark of respect during the funeral feast, men getting the muscle and women and children being fed the poorer brain and guts. It is thought that originally a member of the tribe developed sporadic CJD, and that through cannibalism the disease was spread through the tribe, the bodies of those who died of the disease wee then also eaten, compounding the problem. The epidemic ceased after cannibalism was outlawed in 1956.


Lateral transmission - the passing of a disease from animal to animal, but not parent to offspring. Usually occurs when both animals are alive at the same time and one is exposed to the agent from the other. (see also vertical transmission)


MAFF - Ministry for Agriculture, Fisheries and Food in the UK
Maternal Transmission - see Vertical Transmission
Murine model - the use of mice as subjects to be infected with TSEs, allowing a model of the diseases effects to be created. (see also Transgenic mice).


Neuroanatomy - the anatomy of the Nervous system, brain, spinal chord, peripheral nerves etc.
Neurogenenic culture - a form of cellular culture in which nervous tissue is grow in a test tube so that it can be infected with a TSE, and the agent propagated.


Pathogenesis / Pathology - the damage caused to a tissue by a disease or injury, when the result of a TSE it usually manifests as a deterioration of the nervous tissue (Neuropathology).
Plaques - an unnatural accumulation of substances, TSEs lead to a build-up of protein blockages in the brain which is a classic post-mortem indicator (although other diseases can also have this affect).
Polymerisation - the joining together of many smaller particles to form a large chain. e.g. a PrPc joins onto the end of a PrPsc, is mutated, and as the process is repeated a PrPsc crystal is formed. This is thought to be the way in which Prions build up.
Prion - now widely thought to be the infectious agent of TSEs, they are built up from PrP proteins which are produced naturally in the body, which has been mutated by a TSE. The Prion has been internationally defined as "small proteinaceous infectious particles which resist inactivation by procedures that modify nucleic acids".
Proteinase - very enzymes that can between them break down just about any known protein, except for the disease causing PrPsc. (e.g. Proteinase K found in the body of many animal species and is the most versatile of the Proteinases)
PrP - a protein that is found naturally in the body it comes in a number of different forms:
  • PrPc (cellularPrP) which is made in small amounts in cells, especially in the nervous and lymphatic system.
  • PrPsc (PrPscrapie) the form of PrP that has been mutated by contact with the infective agent of a TSE.

  • Scrapie - the form of TSE that occurs in sheep and goats. It is the oldest known TSE, having been recognised for over two hundred years, it is thought to have originated in Spain and spread throughout the rest of Europe and the world through the trade of live animals, although it does not occur in either Australia or New Zealand.
    SEAC - Spongiform Encephalopathy Advisory Committee - A committee set up in 1989 to advise the British government on BSE and related matters
    Species barrier - a barrier between species of animals that hinders or prevents the passage of a disease between these species. For TSEs to cross the species barrier it appears that a much larger dose of the infectious agent is required.
    Strains - research shows that different forms of TSEs occur in different animals, each with slightly different characteristics to the other forms (e.g. BSE in cattle, Scrapie in sheep, CJD in humans). These different forms are referred to as strains. It is thought that the different strains are caused by slight differences in the glycan structure around the PrPc found in the various species that are affected by TSEs.


    Transgenic mice - these are mice that are used in research into various diseases and have been genetically engineered to carry a specific gene from another animal, injected into the fertilised ovum during gestation; there is quite a high failure rate though as this process is very difficult. Animals used for TSE research are given the PrP gene of another animal so that they will produce that animal's PrP protein instead of their own.
    TSE - Transmissible Spongiform Encephalopathy - a type of disease, split into many strains, which can be transmitted from one animal to another and causes changes in the brain of the sufferer that appear similar to a sponge, and causes pronounced and degenerating ataxia.


    Ultrastructure - The physical and chemical structure of PrP, including the way the proteins are shaped.


    Vertical transmission - the transmission of the illness from parents to offspring, not necessarily before birth.
    Virino - a small particle containing both protein and nucleic acid that could also be the infective agent of TSEs.


    ZSE - Zoological Spongiform Encephalopathy - A strain of TSE that was found in animals kept in certain British zoos that appeared during the early years of the BSE epidemic. In all it affected an Eland, a Nyala, an Arabian Oryx, a Kudu, a Gemsbok, a Cheetah, a Puma and an Ocelot, the infection is thought to have come from the same source as the original BSE agents.


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    The information on this website has not been updated since
    March 1997

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