Volume 2: Science
Glossary of scientific and other terms

Some definitions in this glossary are quoted directly from another source. These sources, abbreviated in the glossary, are listed below.

Words in bold refer to other words also defined in this glossary.
ABRC	Advisory Board for the Research Councils.
ACARD	Advisory Council for Applied Research and Development.
Acetylethyleneimine	A solvent capable of inactivating viruses.
Acinetobacter calcoaceticus	A common bacterium found in large quantities in the soil, sewage and water supplies. Proposed in the autoimmune theory as a possible cause of BSE.
ACOST	Advisory Council on Science and Technology.
AD	Alzheimer's disease.
ADAS	Agricultural Development and Advisory Service.
Adjuvant	A substance enhancing the immune response to an antigen.
Aetiology	Study of the causes or origin of disease.
AFRC	Agricultural and Food Research Council.
Agalactia	Partial or complete absence of milk, or milk flow, from the udder. (BMD)
Agent	A substance or organism that exerts some effect, eg, of disease. The term has a long-standing use in TSE research as being a neutral one which avoids terms used for common pathogens.
AI	Artificial insemination.
Aliquot	A portion of a larger whole.
Alleles	Any of the alternative forms of a gene that may occur at a given gene locus.
Alpha ()-helix	A rod-like structure within proteins, formed when the chain of amino acids forming the protein turns regularly around itself. Alpha-helices and beta ()-sheets are major determinants of protein structure.
Alzheimer's disease (AD)	A degenerative disease of the central nervous system characterised especially by premature senile mental deterioration.
Amino acid	The building blocks of proteins, linked together by chemical bonds. Amino acids contain carbon, hydrogen and oxygen, together with an amine group (NH2). The quality of a protein, in terms of its value as an animal feed, depends upon its content of essential amino acids. There are 20 amino acids, including lysine, methionine, tryptophan, leucine, isoleucine, phenylalanine, threonine, histidine, valine, and arginine. (BVD)
Amphotericin B	An antifungal antibiotic obtained from the soil dwelling bacterium Streptomyces nodosus, used to treat systemic fungal infections.
Amyloid	A substance consisting of protein, in combination with polysaccharides, that is deposited in some animal organs and tissues under abnormal conditions.
Amyloid plaques	Areas of accumulated amyloid in the brain.
Ante-mortem	Before slaughter (literally before death).
Anthelmintic	See antihelminthic.
Anthracycline	Category of chemical derivatives which are known to bind to amyloid fibrils.
Antibody	Substance in the blood which destroys or neutralises antigens. (BMD) Antibodies belong to the globulin family of proteins.
Antigen	A substance which causes the formation of antibodies, ie, provokes an immune response. Antigens are usually proteins that are foreign to the body.
Antihelminthic	A substance used to treat parasitic worms.
Antioxidant	A substance that prevents or inhibits oxidation. (COD)
Aprotonin	An antifibrinolytic agent.
ARC	Agricultural Research Council (later the AFRC, from 1984.
Astrocytosis	Proliferation of specialised cells (astrocytes), in response to damage. Astrocytes are found in the central nervous system and support the function of neurons.
Ataxia	Inability to coordinate voluntary muscular movement.
Attack rate	The number of animals in an experimental group which succumb to a disease after exposure of the group to an infectious agent.
Autoimmune disease	Disease that results from an immune system response against self-antigens. They result from the breakdown of the normal mechanisms of self-tolerance. These diseases include rheumatoid arthritis and diabetes mellitus.
Autonomic nervous system	A part of the vertebrate nervous system that innervates smooth and cardiac muscle and glandular tissues and governs involuntary actions. (For example, it innervates the gastrointestinal system.)
Autosomal	Pertaining to a chromosome other than a sex chromosome.
BABs	Cattle Born After the ruminant feed Ban in July 1988 that have been confirmed as having BSE.
Bases	Chemical components of nucleic acids (adenine, cytosine, guanine and thymine in DNA; adenine, cytosine, guanine and uracil in RNA). The bases are capable of interacting with one another to form base pairs, adenine with thymine (uracil in RNA) and cytosine with guanine. In DNA, pairing by bases on opposite strands of the double helix links the two strands. Together with the sugar and phosphate molecules that form the backbone of nucleic acid, bases are termed nucleotides, three of which constitute a codon. See Figure 1.1.
Batch rendering	The traditional method of rendering whereby discrete quantities of raw animal by-products are cooked/dried in a closed vessel, either under pressure or, more normally, under atmospheric conditions. Batch rendering has been largely replaced by continuous rendering.
BBSRC	Biotechnology and Biological Sciences Research Council.
Beta ()-sheet	A rigid structure within proteins, formed when the chains of amino acids forming the protein fold back on themselves. Together with -helices, -sheets are major determinants of protein structure.
Bioassay	Test for disease using a live animal; in the case of BSE susceptible mice are currently used.
Biopsy (as brain biopsy)	A minor operative procedure to obtain a piece of brain tissue, which is looked at under the microscope and may give a diagnosis in some patients with neurological brain disorders.
Bivalent	A pair of homologous chromosomes, which come together before the first meiotic division.
Blastocyst	A mammalian embryo at the early stage of development at which some differentiation of cells has occurred.
Bovine	Of, relating to, or resembling members of the Bovidae group of animals; ie, cattle.
BSE	Bovine Spongiform Encephalopathy, a slowly progressive and ultimately fatal neurological disorder of adult cattle. See also TSE.
BSEP	Biology of the Spongiform Encephalopathies Programme.
Buffy coat	The thin yellow-white layer of white blood cells on top of the mass of red cells when whole blood is centrifuged.
Cadaver	A dead body.
Carditis	Inflammation of the heart.
Catalyse	To cause or accelerate a chemical reaction. A substance which does so does not undergo any chemical change itself, but causes or accelerates change in another substance.
Catechol sulphate	One of three urine metabolites whose concentrations were investigated for use in BSE diagnosis.
Cell culture	Cultivation of living cells in prepared nutrient media.
Cells	The smallest structural and functional unit of an organism, consisting of cytoplasm and a nucleus enclosed in a membrane. (COD) Cells can function cooperatively as part of a tissue or organ, or independently as free living organisms.
Central nervous system (CNS)	Pertaining to the brain, cranial nerves and spinal cord. It does not include peripheral nerves.
Cerebellar syndrome	A disorder affecting the functioning of the cerebellum.
Cerebellum	A large, dorsally projecting part of the brain concerned with the coordination of muscles and the maintenance of bodily equilibrium.
Cerebral hemispheres (together forming the cerebrum)	The main part of the brain. It consists of two hemispheres separated by a deep cleft, and is concerned with memory, initiative, volition, intelligence, perception, voluntary movement and emotion. (BVD)
Cervical	Of, or relating to the neck. (COD)
Cheviot	Breed of hardy, hornless, relatively small sheep that are a source of quality mutton and have their origin in the Cheviot hills.
Chloroform	A colourless, volatile, heavy toxic liquid (CHCl3), with an ether odour used especially as a solvent or as a veterinary anaesthetic.
Chromatid	Each of the two thread-like strands into which a chromosome divides during cell division. (COD)
Chromosome	A thread-like structure of nucleic acids and associated proteins found in the nuclei of most living cells, carrying genetic information. There are 46 chromosomes (23 pairs) in each human cell nucleus. The chromosome is made up of many genes, which are made of codons, which are each made of three nucleotides.
CJD	Creutzfeldt-Jakob Disease, a human transmissible spongiform encephalopathy. See also TSE.
CJDSU	National CJD Surveillance Unit.
CMO	Chief Medical Officer.
CNS	Central nervous system.
Codon	A sequence of three successive nucleotides in nucleic acid which specifies a particular amino acid or signal sequence.
Cohort study	Maternal transmission study conducted by MAFF. A cohort is a group of animals of the same species, identified by a common characteristic, which are studied over a period of time as part of a scientific or medical investigation.
Collagen	The main structural protein found in animal connective tissue, yielding gelatine when boiled.
Colostrum	The first type of milk secreted by a mammal, for the first three to four days after birth. Contains high levels of protein, vitamins, antibodies, etc.
Compound feedstuff (or feeding stuff)	A mixture of products of vegetable or animal origin in their natural state, fresh or preserved, or products derived from an industrial processing thereof, or organic or inorganic substances whether or not containing additives, for oral animal feeding in the form of complete feedstuffs.
Conformation	The three-dimensional arrangement of side groups on a molecule such as a protein. The conformation of a protein determines its accessibility to proteases.
Conformer	A protein of particular conformation.
Conjugate	To unite or combine with.
Continuous rendering	A method of rendering whereby raw animal by-products are fed into a continuous cooking/drying process. Now the most dominant process worldwide. Manufacturing systems include: Stork Duke Cookers, Stord Bartz Driers, Carver-Greenfield Systems, and Protech Systems.Cf. batch rendering.
Co-translational event	The modification of a protein during its synthesis (translation from mRNA), such as glycosylation or phosphorylation.
Crossing-over	A process whereby parts of maternal and paternal chromosomes are exchanged, resulting in a 'shuffling' of alleles.
CSA	Chief Scientific Adviser.
CSF	Cerebrospinal fluid: the fluid within the brain cavities and bathing its surface and that of the spinal cord.
CSG	Chief Scientist's Group, MAFF
CSL	Central Science Laboratory.
CSP	Council for Scientific Policy.
CVL	Central Veterinary Laboratory, Weybridge, Surrey.
CVO	Chief Veterinary Officer.
CWD	Chronic Wasting Disease, a transmissible spongiform encephalopathy in mule deer and elk. See also TSE.
Cytoplasm	The main body of a cell.
Cytotoxic	Descriptive of substances that are directly toxic to cells, preventing their reproduction or growth.
Daltons	A unit of mass for expressing masses of atoms, molecules, or nuclear particles. It is equal to 1/12 the mass of a single atom of the most abundant form of carbon, carbon-12.
Degradation	The 'unmaking' or dismantling of a protein.
Dementia	A condition of deteriorated mentality often with emotional apathy.
Derris	A preparation of derris roots and stems used as an insecticide.
DES	Department of Education and Science.
Dextran sulphate	A specific carbohydrate known to be active against viruses.
DH	Department of Health (until July 1988, the DHSS).
Diisopropylfluorophosphate	An OP compound.
Diploid	A cell with a full set of genetic material, consisting of chromosomes in homologous pairs and thus having two copies of each gene. A diploid cell has one chromosome from each parental set.
Disulphide bond	Bond between two sulphur-containing amino acids in a folded protein chain. These bonds stabilise the three-dimensional structure of extracellular proteins, and can be broken and reformed by chemical reaction.
DNA	Deoxyribonucleic acid. See nucleic acid.
Dominance	The property of one of a pair of alleles or traits that suppresses expression of the other in the heterozygous condition.
Dominant hemimelia (Dh)	An inherited disorder resulting in abnormal forearms or hands.
Dopamine	A precursor of noradrenaline, a hormone responsible for transmission in the sympathetic nervous system and in some parts of the central nervous system. Dopamine occurs especially as a neurotransmitter in the brain.
Dorsal root ganglia	Swellings on the dorsal roots of spinal nerves . . . they contain the cell bodies of sensory neurons. (BMD)
Dose-response curve	A graph to show the relation between the dose of a foreign substance and the degree of response it produces, as measured by the percentage of the exposed population showing a defined effect. (IPCS)
Double helix	The molecular structure of DNA, in which two strands of DNA, joined together by a base pairing, coil around one another. See Figure 1.1.
Downer cows	Refers to the clinical manifestation of being unable to rise. This is a common occurrence, usually around parturition, and can result from a variety of causes, including neurological disease. It has been proposed that a proportion of cases are in fact cases of BSE.
DTI	Department of Trade and Industry.
Dura mater	The outermost and strongest of the three membranes, or meninges, which envelop the brain and spinal cord. (BMD)