Enzyme-linked Immunosorbent Assay (elisa): From 1 Different Sources
This is a sensitive method for measuring the quantity of a substance. An antibody to the substance is prepared along with an ENZYME which binds to the antibody and which can be accurately measured using colour changes that occur as a result of the chemical reaction.
Usually a protein made by the body to make chemical reactions take place at a faster rate or to cause a colour change in a laboratory test.... enzyme
See ENZYME-LINKED IMMUNOSORBENT ASSAY (ELISA).... elisa
An endonuclease ENZYME, extracted from BACTERIA, that is used to cut DNA into short segments – a process essential in GENETIC ENGINEERING.... restriction enzyme
The way in which a characteristic or an illness determined by the SEX CHROMOSOMES in an individual’s cells is passed on to the succeeding generation. Men have one X and one Y sex chromosome and women have two X chromosomes. Disorders that result from an abnormal number of sex chromosomes include KLINEFELTER’S SYNDROME, which affects only men, and TURNER’S SYNDROME, which affects mainly women. Recessive GENES on the X chromosome cause most other sex-linked characteristics; in women these may well be masked because one of their two X chromosomes carries a normal (dominant) gene. In men, who have just one X chromosome, no such masking occurs – so more men than women are affected by X-linked characteristics or diseases. (See also HEREDITY.)... sex-linked inheritance
Analysis or measurement of a substance to determine its presence or effects. Biological assays (bioassays) measure the responses of an animal or organ to particular substances. They can be used to assess the effects of a drug or to measure hormone levels. (See also immunoassay; radioimmunoassay.)... assay
A substance that converts angiotensin I to its active form, angiotensin. Drugs that reduce the action of this enzyme are known as ACE inhibitor drugs and are used in the treatment of hypertension and heart failure.... angiotensin converting enzyme
Sex-linked genetic disorders in which the abnormal gene or genes (the causative factors) are located on the X chromosome. Almost all affected people are males. Haemophilia, fragile X syndrome. and colour vision deficiency are examples.... x-linked disorders
(ELISA) a sensitive technique for measuring the amount of a substance. An antibody that will bind to the substance is produced; the amount of an easily measured enzyme that then binds to the antibody complex enables accurate measurement.... enzyme-linked immunosorbent assay
(PERT) a therapeutic approach using supplements of the digestive enzymes lipase, amylase, and protease (Creon, Pancrex), which are given when there is insufficient endogenous production of pancreatic enzymes: for example, to patients with pancreatic cancer or cystic fibrosis. The capsules must be taken with all meals and snacks to be effective. PERT treats the symptoms of *steatorrhoea.... pancreatic enzyme replacement therapy
a digestive enzyme that causes the breakdown of protein. See endopeptidase; exopeptidase.... proteolytic enzyme
adj. describing genes (or the characteristics controlled by them) that are carried on the sex chromosomes, usually the *X chromosome. The genes for certain disorders, such as *haemophilia, are carried on the X chromosome; these genes and disorders are described as X-linked. Since most of these sex-linked genes are *recessive, men are more likely to have the diseases since they have only one X chromosome; women can carry the genes but their harmful effects are usually masked by the dominant (normal) alleles on their second X chromosome.... sex-linked
see sex-linked.... x-linked disease
(XLP syndrome, Duncan’s disease) a hereditary disorder of the immune system caused by a defective *sex-linked gene carried on an *X chromosome. There is uncontrolled proliferation of B-*lymphocytes in response to infection by the Epstein-Barr virus, which can lead to fulminating hepatitis or lymphoma. This condition is due to a defect in a gene, SAP, which encodes a signalling molecule found in the cytoplasm of cells.... x-linked lymphoproliferative syndrome
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