Widespread genus of Gram negative aerobic bacilli found in the digestive tract of many vertebrates and on skin. Occasionally cause opportunistic infections.
Water-soluble copper phthalocyanin stain used to demonstrate acid mucopolysaccharides. By varying the ionic strength some differentiation of various types is possible.
Enzyme that mediates conversion of glucose to sorbitol and the rate-limiting enzyme in the polyol pathway. Altered activity of aldose reductase is thought to play a part in the ...
A steroid hormone produced by the adrenal cortex, that controls salt and water balance in the kidney.
Membrane-bounded storage granule within plant cells that usually contains protein. May be an aleuroplast or just a specialized vacuole.
A semi-autonomous organelle (plastid) within a plant cell that stores protein.
Genus of dinoflagellates that produce toxins associated with shellfish poisoning.
A non-taxonomic term used to group several phyla of the lower plants, including the Rhodophyta (red algae), Chlorophyta (green algae), Phaeophyta (brown algae), and ...
Salts of alginic acids, occurring in the cell walls of some algae. Commercially important in food processing, swabs, some filters, fire-retardants etc. Calcium alginates form ...
A process or set of rules by which a calculation or process can be carried out - usually referring to calculations that will be done by a computer.
Carbon compound in which the carbon chain is open (non-cyclic).
aliphatic amino acids
The naturally occurring amino acids with aliphatic side chains are glycine, alanine, valine, leucine and isoleucine.
Small portion. It is common practice to subdivide a precious solution of reagent into aliquots that are used when needed without handling the total sample.
Enzyme (EC 18.104.22.168) catalysing cleavage of inorganic phosphate nonspecifically from a wide variety of phosphate esters, and having a high (>8) pH optimum. Found in bacteria, ...
A nitrogenous base. Usually refers to biologically active (toxic) molecules, produced as allelochemicals by plants to deter grazing. Examples: ouabain, digitalis
Congenital absence of homogentisic acid oxidase, an enzyme that breaks down tyrosine and phenylalanine. Accumulation of homogentisic acid in homozygotes causes brown ...
A reagent that places an alkyl group, eg. propyl in place of a nucleophilic group in a molecule. Alkylating reagents include a number of cytotoxic drugs some of which react ...
Acute lymphoblastic leukaemia.
Of an action potential, meaning that action potentials once triggered are of a stereotyped size and shape, irrespective of the size of stimulus that triggered them.
Outgrowth from the ventral side of the hindgut in embryos of reptiles, birds and mammals. Serves the embryo as a store for nitrogenous waste and in chick embryos fuses with the ...
Peptide hormones produced by the corpora allata of insects that reversibly inhibit the production of juvenile hormone. Similar peptides are found in other phyla. ...
Different forms or variants of a gene found at the same place, or locus, on a chromosome. Assumed to arise by mutation.
The process whereby one or more loci on one of the chromosome sets in a diploid cell is inactivated (or destroyed) so that the locus or loci is (are) not expressed in that ...
Substances effecting allelopathic reactions. See allelopathy.
One of several alternative forms of a gene: commonly shortened to allele.
The deleterious interaction between two organisms or cell types that are allogeneic to each other (the term is often applied loosely to interactions between xenogeneic ...
Occurence of an allele in a population or an individual with a particular allele. The allelotype of a tumour, the expression of particular microsatellite markers or isoenzymes, ...
Allen video enhanced contrast
A method for enhancing microscopic images pioneered by R. D. Allen. The digitized image has the background (an out-of-focus image of the same microscopic ...
In an animal, a hypersensitivity response to some antigen that has previously elicited an immune response in the individual, producing a large and immediate immune response. ...
Genus that includes onions ( A. cepa ), leeks ( A. porrum ), and garlic ( A. sativum ).
Antibody raised in one member of a species that recognizes genetic determinants in other individuals of the same species. Common in multiparous women and ...
Individuals of a species differ in alleles (are allogeneic) and the antigenic differences will cause an immune response to allografts. The antigens concerned are often of the ...
Anything found at a site remote from that of its origin.
Two or more individuals (or strains) are stated to be allogeneic to one another when the genes at one or more loci are not identical in sequence in each organism. Allogenicity is ...
Grafts between two or more individuals allogeneic at one or more loci (usually with reference to histocompatibility loci). As opposed to autograft and xenograft.
Compound produced by one organism that affects, detrimentally, the behaviour of a member of another species. If the benefit is to the recipient the substance is referred to as a ...
Polyploid condition in which the contributing genomes are dissimilar. When the genomes are doubled fertility is restored and the organism is an amphidiploid. Common in plants but ...
(= 4-hydroxypyrazolo-(3,4-d) pyrimidine)
A xanthine oxidase inhibitor used in the treatment of gout.
One or more chromosomes that can be distinguished from autosomes by their morphology and behaviour. Synonyms: accessory chromosomes, heterochromosomes, sex chromosomes.
Of a binding site in a protein, usually an enzyme. The catalytic function of an enzyme may be modified by interaction with small molecules, not only at the active site, but also ...
Example of allopolyploidy in which the hybrid diploid genome (formed from two chromosome sets) doubles in chromosome number.
(= allotypic determinant)
The structural region of an antigen that distinguishes it from another allotype of that antigen.
Products of one or more alleles that can be detected as inherited variants of a particular molecule. Usually the usage is restricted to those immunoglobulins that can be ...
Used to produce diabetes mellitus in experimental animals. Destroys B cells in the pancreas by a mechanism involving superoxide production.
Variant of an enzyme coded by a different allele. See isoenzyme.
Baldness - can take various forms; alopecia areata in which hair loss is patchy, alopecia universalis in which loss is complete.
Large (725 kD) plasma antiprotease with very broad spectrum of inhibitory activity against all classes of proteases. Apparently works by trapping the ...
A protein of 100 kD normally found as a dimer and that may link actin filaments end-to-end with opposite polarity. Originally described in the Z-disc, now known ...
An endo-amylase enzyme that rapidly breaks down starch to dextrins.
See A cells of endocrine pancreas.
Proteins from the serum of vertebrate embryos, which probably fulfil the function of albumin in the mature organism. Found in both glycosylated and ...
A particular helical folding of the polypeptide backbone in protein molecules (both fibrous and globular), in which the carbonyl oxygens are all hydrogen-bonded to ...
Postsynaptic neurotoxins, many varieties of which are found in snake venoms. Two subclasses, short (four disulphides, 60-62 residues) and long (five disulphides ...
Anti-tumour factor (ribotoxin; 17 kD) from Aspergillus giganteus. Is generally cytotoxic and has high specificity as an RNAase, binding to the 28S rRNA. One of a ...
Protein that accumulates in the brain in Parkinson&’s disease particularly in Lewy bodies. Mutations in the gene are associated with some familial forms of Parkinsonism.
Genus of the Togaviridae family of RNA viruses. Sindbis and Semliki Forest viruses are the best known examples.
Commonest of the hereditary nephropathies. Associated with nerve deafness and variable ocular disorders. Seems to be due to a defect in basement membrane.
altered self hypothesis
The hypothesis that the T-cell receptor in MHC-mediated phenomena recognizes a syngeneic MHC Class I or Class II molecule after modification by a virus or certain chemicals. ...
alternative oxidase pathway
Pathway of mitochondrial electron transport in higher plants, particularly in fruits and seeds, that does not involve cytochrome oxidase and thus is resistant to cyanide.
Eukaryotic genes are composed of exons and introns, the latter being removed by RNA splicing before transcribed mRNA leaves the nucleus. Commonly, a single gene can encode ...
(1) Type II restriction endonuclease, isolated from Arthrobacter luteus. The recognition sequence is 5\'- AG/CT-3\'.
(2) Alu sequences are highly repetitive sequences found in ...
Macrophage found in lung and that can be obtained by lung lavage; responsible for clearance of inhaled particles and lung surfactant. Metabolism slightly different from ...
A presenile dementia characterized cellularly by the appearance of unusual helical protein filaments in nerve cells (neurofibrillary tangles), and by degeneration in cortical ...
A class of neuron of the middle layer of the retina, with processes parallel to the plane of the retina. They are thought to be involved in image processing.
(= a-, b-, g-amanitin)
Group of cyclic peptide toxins. The most toxic components of Amanita phalloides (Death cap toadstool). Specific inhibitors of RNA polymerase II in ...
Used as an antiviral agent (especially against influenza virus). Produces some symptomatic relief in Parkinsonism.
One of the three termination codons. Its sequence is UAG. See also ochre codon, opal codon.
Mexican axolotl (amphibian). A salamander that shows neoteny. The adult may retain the larval form, but can reproduce. The neotenous, aquatic axolotl will metamorphose into the ...
Columnar epithelial cells that secrete the enamel layer of teeth in mammals. Their apical surfaces are tapering (Tomes processes) and are embedded within the enamel matrix.
Extracellular matrix proteins (20 and 25 kD) of developing dental enamel; regulate form and size of hydroxyapatite crystallites during mineralisation. Hydrophobic and ...
One of a number of procedures used to test substances for likely ability to cause cancer that combines the use of animal tissue to generate active metabolites of the substance ...
A C-terminus consensus sequence, required for C-terminus amidation of peptides. Consensus is glycine, followed by 2 basic amino acids (arg or lys).
Drug that blocks sodium/proton antiport; used clinically as a potassium-sparing diuretic.
amino acid permease
A widely distributed group of large integral membrane proteins, required for the entry of amino acids into cells.
amino acid receptors
Ligand-gated ion channels with specific receptors for amino acid neurotransmitters. An extended protein superfamily that also includes subunits of the nicotinic acetylcholine ...
amino acid transmitters
Amino acids released as neurotransmitter substances from nerve terminals and acting on postsynaptic receptors eg. g -aminobutyric acid (GABA) and glycine that are fast ...
Organic acids carrying amino groups. The L-forms of about 20 common amino acids are the components from which proteins are made.
Monosaccharide in which an OH-group is replaced with an amino group; often acetylated. Common examples are D-galactosamine, D-glucosamine, neuraminic acid, muramic acid. Amino ...
Complex of an amino acid to its tRNA, formed by the action of aminoacyl tRNA synthetase. Requires ATP, which forms the linkage between the two molecules.
aminoacyl tRNA synthetases
Enzymes that attach an amino acid to its specific tRNA. An intermediate step is the formation of an activated amino acid complex with AMP; the AMP is released following ...
Group of antibiotics active against many aerobic Gram negative and some Gram positive bacteria. Composed of two or more amino sugars attached by a glycosidic linkage to a ...
Enzymes that remove the N-terminal amino acid from a protein or peptide.
A folic acid analogue and inhibitor of dihydrofolate reductase. A potent cytotoxic agent used in the treatment of acute leukaemia.
An unusual form of nuclear division, in which the nucleus simply constricts, rather like a cell, without chromosome condensation or spindle formation. Partitioning of daughter ...
Acute myeloblastic leukaemia.
(= atx A, B & C; ammodytin L)
Group II secretory phospholipases A2 (122 residues) found in the venom of Vipera ammodytes. Act specifically at peripheral nerve endings in the ...
Sampling of the fluid in the amniotic sac. In humans this is carried out, between the 12th and 16th week of pregnancy, by inserting a needle through the abdominal wall into the ...
Terrestrial vertebrates have embryos that develop in fluid-filled sacs formed by the outgrowth of the extra-embryonic ectoderm and mesoderm as projecting folds. These folds ...
Sac, enclosing the embryo of amniote vertebrates, that provides a fluid environment to prevent dehydration during development of land-based animals. See amnion.
Genus of protozoa, but also an imprecise name given to several types of free-living unicellular phagocytic organism. Giant forms (eg. Amoeba proteus ) may be up to 2mm long, ...
Phagocytic cells found circulating in the body cavity of coelomates (particularly annelids and molluscs), or crawling through the interstitial tissues of sponges. A fairly ...
Crawling movement of a cell brought about by the protrusion of pseudopods at the front of the cell (one or more may be seen in monopodial or polypodial amoebae, respectively). ...
(= adenosine monophosphate)
Unless otherwise specified, 5\'AMP, the nucleotide bearing a phosphate in ribose-O-phosphate ester linkage at position 5 of the ribose moiety. ...
(= 5&’-adenylyl imidodiphosphonate)
Non-hydrolysable analogue of ATP used in isolation of some motor proteins.
Synthetic agonist for metabotropic glutamate receptors.
Glutamate-operated ion channel. See excitatory amino acid receptor channels.
Drug of abuse that acts by increasing extraneuronal dopamine in midbrain. Thought to displace dopamine in synaptic vesicles, leading to increased synaptic levels.
Description of a pathway that functions not only in catabolism, but also to provide precursors for anabolic pathways.
Sexual reproduction resulting in an individual having two parents. Invariably the case in most animals, with the exception of a few hermaphrodite organisms, but not uncommon in ...
Of a molecule, having both hydrophobic and hydrophilic regions. Can apply equally to small molecules, such as phospholipids, and macromolecules such as proteins.