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.
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.
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.
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.
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)
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".
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.
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.
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 BSEagents.
