are tiny strings of protein. The name is derived from Proteinaceous
Infectious Particle. Although they cannot be
classified as truly "living", they are infectious agents consisting
entirely of protein without any nucleic acid. Like many
complex organic molecules, their structure is chiral (right or left-handed)
and while left- handed molecules are harmless, the right-handed molecule
is potentially highly dangerous as well as being infectious.
are noted for causing brain degeneration - new-form Creutzfeldt-Jakob
Disease (CJD) in humans. This is believed to derive from Bovine
Spongiform Encephalopathy (BSE) - "Mad
Cow Disease" - which devastated the United Kingdom's
cattle herds in the 1980's and still poses a risk. The Sheep
disease "Scrapie" is another form of prion disease and it is possible
that BSE originally derived from it.
more information visit UK
Government, Ministry of Agriculture BSE Information Site. and
the Official Mad Cow Disease Home
are outside the area of study considered on this site.