Groups and bodies

ACDP

Advisory Committee on Dangerous Pathogens. Government Committee which regularly produces information regarding the handling of dangerous materials.

CVL

Central Veterinary Laboratory. The government laboratory which performs a substantial amount of research into BSE.

DoH

The UK Department of Health.

MAFF

Ministry of agriculture fisheries and food in the UK.

NPU

Neuropathogenesis Unit. A research unit with substantial experience of the investigation of scrapie, jointly funded by the Biotechnology and Biological Sciences Research Council and the Medical Research Council.

SEAC

Spongiform Encephalopathy Advisory Committee. Government formed committee consisting of independent experts in the field of spongiform encephalopathy.

Scientific and medical terms

Alzheimer's disease

The most common dementing illness of the elderly in the UK. The neuropathology of Alzheimer's is significantly different from that of CJD and the clinical course of the disease is normally of the order of several years.

Amyloid

A chemical struture which can accumulate in brain tissue as a result of a variety of different diseases. In CJD the amyloid is normally made-up of the prion protein.

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

Common cell type in the brain that supports the functions of the neurons.

Astrocytosis

The proliferation of astrocytes in brain tissue. This is a common finding in CJD neuropathology but it is not specific to this disease.

Ataxia

Inability to coordinate muscle control resulting in irregularity of movements.

Bioassay

The inoculation of an infective substance into another animal in order to see if the second animal develops the same disease. Different dilutions of tht infective substance are used to assess how infective the substance is.

BSE

Bovine spongiform encephalopathy (or mad cow disease).

Clinicopathological correalations

The similarites between the clinical symptoms of a patient and the pathological findings. For example, ataxia in a patient may relate directly to cerebellar degeneration when this part of the brain is examined under the microscope.

CNS

Central nervous system. General term used to described the brain and the spinal cord.

CJD

Creutzfeldt-Jakob disease. The most common human SE which is characterised by a rapidly progressive dementia. Identified in the 1920s through the work of Creutzfeldt and Jakob.

CSF

Cerebrospinal fluid. The clear fluid that surrounds the brain and spinal cord, filling the ventricles of the brain.

DNA

Deoxyribonuclic acid. The chemical that carries the genome in the chromosome of animals, plants and some viruses.

Dominant

The extent to which a gene is expressed; dominant indicates that it is expressed a lot.

Downer cows

A term used in the US to describe cattle that do not have the ability to stand, it has never been proven that any of these cows have BSE.

EEG

Electroencephalogram. The trace of electrical activity in the brain. In patients with CJD this can, but doesn't always, show characteristic signs.

Epidemiology

The study of distribution of cases of a disease.

FFI

Fatal Familial Insomnia. A genetic disease found in humans which does not have the pathological hallmark of the spongiform encephalopathies but is related to a genetic mutation of the prion protein gene.

FSE

Feline spongiform encephalopathy. A recently discovered SE of the domestic cat, thought to be related to the consumption of BSE material in cat food.

Gene

A unit of material which contains DNA and forms part of chromosome which is resposible for one function. Hence the genetic make-up of an individual determines their physical attributes.

Genetic Mutation

A chemical change in the genes of a cell which cause it to have a different function.

Genotype

The genetic make-up of an individual.

GSS

Gertmann-Straussler-Scheinker Disease. A familial SE found in humans and associated with a few specific mutations of the PrP gene.

Iatrogenic

A disorder with is caused by a medical treatment. In CJD a certain number of cases appear to have resulted from injections of infected growth hormone material.

Immunohistochemistry

Chemical techniques used to indentify the deposit of particular chemicals or proteins in tissue. Common used to locate prion protein in brain tissue from SE using an anti-PrP antibody.

Infectious Agent

The chemical organism that causes a particular disorder. Scientific opinion is divided about the biological nature of the agent that causes SEs. The two main theories are the Prion hypothesis and the Virus theory.

Kuru

A TSE found only in the Fore tribe in New Guinea most likely related to ritualistic cannabalism carried out amoung members of the tribe. Transmissibility of the disease has been established through the work of Gadjusek.

Locus

The position a gene occupies in the chromosome.

Maternal transmission

The transmission of disease from the mother to the offspring.

Microglia

Immune cells from inside the CNS

Murine models

models of disease, using mice as the animal being infected.

Myoclonus

Neuroanatomy

The anatomy of the brain, spinal cord and peripheral nervous system.

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.

Pathology

The study of disease infected tissue.

PCR

Polymerase chain reaction. A method used to make multiple copies of DNA. A stage used in the examination of a DNA sample to determine whether they have a genetic mutation or not.

Peripheral nervous systems

The nerves and sensory systems outwith the brain and spinal cord.

Phenotype

The effect made on the organism by the genes that it carries. Some genes (see genotype) may have no effect.

Plaques

The accumulation of protein that may build up in brain tissue as a result of infection.

Prion

PROteinaceous INfectious agent. The prion theory suggests that the infective agent of CJD (and the other TSEs) is only composed of a protein and does not contain nucleic acid which would be necessary if the agent was a conventional virius.

PrP

The prion protein. This is a normally occuring protein found on the surface of particular cell types - PrPC. The abnormal form PrPCJD (or PrPScrapie) accumulates in the disease brain and is thought to be the main (or only) consistuent of prions.

RNA

Ribonucleic acid. Often found in viruses as the nucleic acid that carries the genome of the agent.

SAF

Scrapie associated fibrils. These are the fine structures, seen under the electron microscope that are only found in brains of TSEs.

Scrapie

The TSE of sheep or goats.

SE

Spongiform encephalopathy.

Species barrier

The naturally occuring barrier between different species of animal which makes transfer of a disease from one to the other difficult.

Sporadic

Cases of CJD that occur at random throughout the world are categorised as sporadic if they have no genetic mutation or any known iatrogenic infection.

Strains

Different forms of the sheep TSE scrapie have been isolated by transmission to mice. These strains cause variations in the incubation period and pattern of pathology observed in the infected animal. As yet no strains of CJD have been identified.

TME

Transmissible mink encephalopathy. This is a SE of mink found in mink farms in the US. It was initial reported in the 1960s.

TSE

Transmissible spongiform encephalopathy. A disease that has the pathology characteristic

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 cells.