ACDP.
Advisory Committee on Dangerous Pathogens
ADAS
Agricultural Development and Advisory Service. This was a government
organization that provided cheap veterinary and agricultural advice to
farmers. The Thatcher Government decided that the farmers should pay higher
prices and that it should be privatized if possible. As a result it was
decreased in size dramatically.
Agent
The element that is able to transmit a disease. We are currently unsure what
the absolute agent is for a TSE (such as CJD). Some arguments suggest that
it is a virus (see Diringer) some that it is a virino (see Kimberlin or
Narang) and many that it is a prion (see Bolton or Prusiner).
Alzheimer's Disease
A specific disease associated with the breakdown of nervous tissue in the
brain, giving rise to a dementia in the patient. This seems to be one of the
most common conditions of older people in the Western world.
Amyloid
A chemical that builds up inside tissue in an amorphous way.
Amyloidogenesis
The production of amyloid
Amyloidosis
The build up of amyloid to a degree that it causes damage to the tissues or
action of those tissues in the body.
Astrocyte
One of the brain cells that supports the nervous tissue.
Astrocytosis
The spread of astrocytes into damaged tissue.
Ataxia
Loss of coordination by an animal with neurological damage.
Bioassay
The inoculation of tissue into another animal in order to see if it is
infective (if it is, the animal will develop disease). Multiple dilutions of
the inoculum will, if the dilutions are enough, get to the point that not
enough infection is present in the inoculum to cause disease. The lowest
amount of inoculum that will still transmit the disease is said to contain
one infective unit.
Birefringence
The appearance under the microscope of Congo red staining of amyloid.
BSE
Bovine spongiform encephalopathy
cDNA
the DNA of the chromosome i.e. chromosomal DNA.
cerebellum n.
- the largest part of the hindbrain, bulging back behind the pons and the
medulla oblongata and overhung by the occipital lobes of the cerebrum. Like
the cerebrum, it has an outer gray cortex and a core of white matter. Three
broad bands of nerve fibers - the inferior, middle, and superior
cerebellar peduncles
connect it to the medulla, the pons, and the midbrain, respectively. It has
two hemispheres, one on each side of the central region (the vermis), and
its surface is thrown into thin folds called folia. Within lie four pairs of
nuclei.
The cerebellum is essential for the maintenance of muscle tone, balance, and
the synchronization of activity in groups of muscles under voluntary
control, converting muscular contractions into smooth coordinated movement.
It does not, however, initiate movement and plays no part in the perception
of conscious sensations or in intelligence. -cerebellar adj.
cerebellar ataxia n.
clumsiness of willed movements. The patient staggers when walking; he cannot
pronounce words properly and has *nystagmus.
Cellular culture
The culture of individual cells in a test-tube. Some of these can be
infected with a TSE agent and these cultures can then be used to see if a
drug may work against the agent
Chronic wasting disease
(of deer)
A disease found at Fort Worth Zoo only in deer and elk.
Crystalloids
The build up of PrP in a crystal form in such a way as to induce the
production of PrPsc from PrPc.
Clinicopathological
correlations
The association between the damage that appears to the brain under the
microscope and the damage that appears to have happened to the activity of
the brain.
CNS
Central nervous system..
Congo red
A specific dye that is used to stain amyloid but has also been found to
inhibit the build up of PrP in infected tissue in culture.
Congophilic
Material in histological sections that becomes stained by Congo red.
Creutzfeldt-Jakob Disease
A TSE that gives rise to a pre-senile dementia in human.
CSF
Cerebrospinal fluid
CVL
Central Veterinary Laboratory
dementia n.
a chronic or persistent disorder of the mental processes due to organic
brain disease. It is marked by memory disorders, changes in personality,
deterioration in personal care, impaired reasoning ability, and
disorientation. Presenile dementia occurs in young or middle-aged people.
The term is sometimes reserved for Alzheimer's disease and Pick's disease,
but it is important to distinguish these conditions from those brain
diseases for which curative treatment may be available.
DNA
Deoxyribonucleic acid. The chemical that carries the genome in the
chromosome of animals, plants and some viruses.
DoH
Department of Health, UK
Dominant
The extent to which a gene is expressed; dominant indicates that it is
expressed a lot.
Downer cows
Cattle that show neurological problems (an American term)
dysarthia n.
a speech disorder in which the pronunciation is unclear although the
linguistic content and meaning are normal.
dysphagia n.
condition in which the action of swallowing is either difficult to perform,
painful (see odynophigia), or in which swallowed material seems to be held
up in its passage to the stomach. It is caused by painful conditions of the
mouth and throat, obstruction of the pharynx or esophagus by diseases of the
wall or pressure from outside, or by abnormalities of muscular activity of
the pharynx or esophagus.
EEG
Electroencephalogram
Electrophoresis
The drawing of a mixture of proteins through a fine gel by an electric
current. This separates the proteins so that they can be identified.
Epidemiology
The changes in the numbers of cases of disease in relation to time and
space.
Episome
A part of a gene.
Esophagitis n.
inflammation of the esophagus (gullet). Symptoms include heartburn,
regurgitation of bitter fluid, and sometimes difficulty in swallowing. It
may be caused by hernia, fungus infection or virus infection.
EU
European Union.
Famillial Fatal Insomnia
A clinical disease found in humans that has been found to be a TSE and is
due to a specific change found in the prion protein.
Freidreich's ataxia n.
an inherited disorder appearing first in adolescence. It has the features of
cerebellar ataxia, together with spasticity of the limbs.
Frontal lobe n.
portion of the brain containing the motor cortex responsible for control of
voluntary movement.
FSE
Feline spongiform encephalopathy
Genome
The total make-up of the genes for an infective agent (or any other life).
Genotype
The types of the genes of an organism.
Gertmann-Straussler-Scheinker
A familial TSE found in humans and associated with a specific change in the
PrP gene.
Glycoform
A type of protein with a specific type of glycoprotein attached. i.e. two
proteins would be of the same glycoform if they carried the same
glycoprotein. This was important in that Dealler's hypothesis that the
strain of prion disease depended on the glycan chain was shown to some
degree by Collinge et al in 1996 and that this inferred that treatment was
possible.
Glycoprotein
A protein that carries attached to it some chains of sugars (glycans). PrP
carries two of these chains and it has been suggested that it is different
chains that actually separate the strains of TSEs.
Glycosylated
With a carbohydrate added.
Iatrogenic cases
These are the cases of CJD that appear as a result of medical activity
inoculating the disease into the patient. e.g. growth hormone inoculations,
corneal transplants, dura mater grafts and various surgical procedures.
HPLC
a method of separating molecules using liquid chromatography
Immunoblotting
The removal of specific proteins onto a filter paper, and then testing the
paper for the protein. This is a way of purifying and being sure of what is
found.
Immunohistochemistry
The testing of sections of tissue for specific proteins by attaching them
with specific antibodies, and then looking for the antibodies through the
enzymes to which they were connected.
Immunolabelling
The testing of sections of tissue (or electron microscopy samples) by
attaching antibodies to specific proteins in the tissue. The antibodies may
have further labels attached to them and it is these that act as the labels.
Immunostaining
As in immunohistochemistry but using a dye as the indicator.
Infective range
The range of animals that a disease can infect.
Infective Unit
This is the minimum amount needed to transmit a TSE from one animal to
another of the SAME species.
Inversely related
One item affects another so that when one increases the other drops.
Kuru
A disease found in the Fore tribe in New Guinea, and due to the eating of
human infected tissue by members of a tribe. In general the women ate brain
tissue rather than the men and so it was the women and children that died
relatively rapidly of the disease.
Lateral (or horizontal)
transmission
transmission of a disease from one animal to another except from the parent
to the offspring. Generally this is the transmission between two animals
alive at the same time and for one to be exposed to the agent from the
other.
MAFF
Ministry of agriculture fisheries and food in the UK.
Maternal transmission
The transmission of disease from the mother to the offspring (not
necessarily before birth).
MBM
Meat and bone meal.
Microglia
immune cells from inside the CNS
Murine models
models of disease, using mice as the animal being infected.
Myoclonic jerks n.
Occasional jerks which occur between seizures in patients with idiopathic
*epilepsy
myoclonus n.
a sudden spasm of the muscles typically lifting and flexing the arms.
Occasional myoclonic jerks occur between seizures in patients with
idiopathic *epilepsy, and myoclonus is a major feature of some progressive
neurological illnesses with extensive degeneration of brain cells. myoclonic
adj.
Neuroanatomy
The anatomy of the brain, spinal cord and peripheral nervous system.
Neurogenenic culture
The growth of nervous tissue in the test tube for the growth of the TSE
agent in the tissue.
Neurogenesis
The production of new nervous tissue.
Nystagmoid jerks n.
Jerking movements which sometimes occur in normal people when tired and when
there is an exaggerated movement of the eyes. They do not imply disease.
nystagmus n.
rapid involuntary movements of the eyes that may be from side to side, up
and down, or rotatory. Nystagmus may be congenital and associated with poor
sight; it also occurs in disorders of the part of the brain responsible for
eye movements and their coordination and in disorders of the organ of
balance in the ear or the associated parts of the brain. Optokinetic
nystagmus occurs in normal people when they try to look at a succession of
objects moving quickly across their line of sight. Jerking movements
sometimes occur in normal people when tired and when there is an exaggerated
movement of the eyes. These are called nystagmoid jerks and they do not
imply disease.
odynophagia
n.
a sensation of pain behind the sternum as food or fluid is swallowed;
particularly, the burning sensation experienced by patients with
*esophagitis when hot, spicy, or alcoholic liquid is swallowed.
Optokinetic nystagmus
n. rapid involuntary movements of the eyes that may be from side to side, up
and down, or rotatory and occur in normal people when they try to look at a
succession of objects moving quickly across their line of sight.
OTM
Over thirty months. See TMR.
PAGE
polyacrylamide gel electrophoresis to separate molecules.
Parenteral
Inoculation into the body (not by mouth)
Passage
The inoculation of an infection into an animal and then harvesting the
infective agent from the animal.
Pathogenesis
The production of damage (pathology) in a tissue.
PCR
Polymerase chain reaction. A method use to make multiple copies of DNA.
Peripheral
This generally refers to the ingestion or inoculation of material into an
animal outside the central nervous system.
Phenotype
The effect made on the organism by the genes that it carries. Some genes
(see genotype) may have no effect.
Pick's disease
n. a rare cause of dementia in middle-aged people. The damage is mainly in
the *frontal and *temporal lobes of the brain, in contrast with the diffuse
degeneration of *Alzheimer's disease.
Plaques
The proteinaceous elements that may build up in brain tissue as a result of
infection. They may, however, be found in other diseases apart from a TSE.
Polymerisation
This is the way that prions may be thought to build up. i.e. by one PrPc
joining onto the end of a PrPsc crystal.
Precursor
The chemical element that changes due to enzymatic or physical pressure.
Prefrontal lobe
n. portion of the brain concerned with behavior, learning, judgment and
personality.
Presenile dementia
n.
dementia which occurs in young or middle-aged people. The term is sometimes
reserved for Alzheimer's disease and Pick's disease.
Prion
This is the protein that makes up the infectious agent claimed by a large
number of groups now to be the infectious particle that transmits the
disease from one cell to another and from one animal to another. It is made
from the normal protein PrPc (the c stands for chromosomal) that is produced
in small quantities on many cells and especially the lymphoid and nervous
tissue cells.
Prion rods
The microscopic rods that appear when prions, that have been broken up with
proteinase K but then allowed to come back together into crystalline forms.
Promoter
A chemical agent that causes the expression of a gene or the change in the
way that it acts.
Protease K
This is the enzyme that breaks down proteins very powerfully...but the
protein that is found in an infected cell is, for some reason not broken
down by the enzyme.
PrP
The prion protein. It can exist in various forms. One is called PrPc and is
the normal type of the protein that is found in a cell (i.e. chromosomal
PrP). One is called PrPsc (or PrPscrapie) that is found in the infected
cells. It may be called PrP-res, indicating that it is difficult to break
down with proteinases. PrP27-30 is the name of the prion protein after it
has been broken up by protease K.
RNA
Ribonucleic acid. Often found in viruses as the nucleic acid that caries the
genome of the agent.
Romberg's sign n.
evidence of a sensory disorder affecting those nerves that transmit
information to the brain about the position of the limbs and joints and the
tension in the muscles. The patient is asked to stand upright. Romberg's
sign is positive if he maintains his posture when his eyes are open but
sways and falls when his eyes are closed.
SAF
Scrapie associated fibrils. These are the fine structures, seen under the
electron microscope that are only found in brains of TSEs. It has been
suggested that they are the infective agents themselves, as infectivity can
be filtered out with a filter small enough to stop the SAF.
SBO
Specified bovine offals. These were the offals of any cow that were thought
to represent a risk to the population. Introduced in 1989. Thymus, brain,
spinal cord, gut (below duodenum), spleen, tonsils.
SBM
Specified bovine materials. These were the parts of a slaughtered cow that
were not considered acceptable for human consumption as of around December
1995. The name was changed from SBO because some of the new materials were
not offals.
Scrapie
The TSE of sheep or goats.
SDS
The compound used in solvents and to attach to proteins (and hence allow
them to be electrophoretically separated).
SEs
Spongiform encephalopathy.
SEAC
Spongiform encephalopathy advisory committee. Tyrrell committee. UK
SERC
Spongiform encephalopathy research campaign. UK
Species barrier
There appears to be needed much greater a quantity of infectivity to pass a
TSE from one species to another rather to a species that is the same as the
one from which the sample has come.
Sporadic cases
The cases of CJD (or perhaps other TSEs) that are apparently not associated
with a change in the gene of the person developing the disease and not
associated with the inoculation of infective material.
Strains
It appears that some forms of a TSE in a
specific animal may have different characteristics from other forms. These
are known as separate strains.
Sulphated-glycan
inhibition
The chemicals that have been found to prevent infectivity of inoculated
agent.
Syphilis,
Tertiary symptoms - n. In the tertiary stage of syphilis, brain damage can
cause neurosyphilis resulting in *tabes dorsalis, blindness and general
paralysis of the insane.
TMR
Thirty Month Rule. The rule introduced in April 1996 by the demand of the
farmers in the UK (stated as unnecessary by MAFF) that cattle over 30 months
of age should not be used for human food.
tabes dorslis (locomotor
ataxia) n.
a form of neurosyphilis occurring 5-20 years after the original venereal
infection. The infecting organisms progressively destroy the sensory nerves.
Severe stabbing pains in the legs and trunk, an unsteady gait, and loss of
bladder control are common. Some patients have blurred vision caused by
damage to the optic nerves. Penicillin is used to arrest the progression of
this illness. See also syphilis, general paralysis of the insane.
Temporal lobe n.
portion of the brain concerned with appreciation of sound and spoken
language.
Transgenic mice.
These are mice carrying a specific gene from another animal. There may be
more than one copy of the gene (for instance, in many transgenic mice
containing the human PrP gene there may be over 20 copies) and may actually
replace the gene that is there normally. The gene is unlikely to be at the
same site as the normal gene in the animal chromosome. To insert the gene
requires the DNA to be inserted into the fertilized ovum of the animal and
hence is very difficult indeed, with many failures.
Transmissible Mink
Encephalopathy
or TME. This is the TSE of mink and has been known for around 30 years,
particularly in the mink farms of the USA.
Transmissible Spongiform
Encephalopathy
A disease that can be transmitted from one animal to another and will
produce changes in the brain that are appear similarly to a sponge (i.e.
some of the cells are clear when seen down the microscope)
Tubulofilamentous
particles
The particles seen under the electron microscope that may be associated with
infectivity.
Ultrastructure
The physical and chemical structure of the amyloid or PrP. Often this
includes the way in which the proteins are shaped.
Vertical transmission
The transmission of an illness from the parent(s) to the offspring.
Virino
A small item that may be the infective agent of a TSE. It contains protein
and nucleic acid.
Viroids
Small virus-like particles. A term used often in TSE to get around the fact
that the infective agent is not yet known.
Virus
A infective agent with a specific structure and able to cause its own
multiplication after infection of specific cell.
