| beta-carotene | An antioxidant which protects cells against oxidation damage that can lead to cancer. Beta carotene is converted, as needed, to vitamin A. A yellow carotenoid pigment that gives a reddish colour to plants such as carrots and tomatoes. It is often used as a vitamin supplement because the liver can convert it into Vitamin A. Food sources of beta-carotene include vegetables such as carrots, sweet potatoes, spinach and other leafy green vegetables; and fruit such as cantaloupes and apricots. Excessive carotene in the diet can temporarily yellow the skin, a condition called carotenaemia, commonly seen in infants fed largely mushed carrots. (12 Dec 1998) |
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| beta-carotene 15,15'-dioxygenase | <enzyme> An enzyme catalyzing the reaction of beta-carotene plus O2 producing two retinals. Synonym: beta-carotene cleavage enzyme, carotenase, carotinase. (05 Mar 2000) |
| beta-carotene cleavage enzyme | <enzyme> An enzyme catalyzing the reaction of beta-carotene plus O2 producing two retinals. Synonym: beta-carotene cleavage enzyme, carotenase, carotinase. (05 Mar 2000) |
| beta-carotene hydroxylase | <enzyme> O2-dependent NADPH-dependent monooxygenase from erwinia herbicola; forms zeaxanthin; amino acid sequence has been determined; genbank m87280 Registry number: EC 1.14.13.- Synonym: beta-carotene monooxygenase, crtz gene product (26 Jun 1999) |
| carotene, beta | An antioxidant which protects cells against oxidation damage that can lead to cancer. Beta-carotene is converted, as needed, to vitamin A. Food sources of beta carotene include vegetables such as carrots, sweet potatoes, spinach and other leafy green vegetables; and fruit such as cantaloupes and apricots. Excessive carotene in the diet can temporarily yellow the skin, a condition called carotenaemia, commonly seen in infants fed largely mushed carrots. (12 Dec 1998) |
| plus | 1. <mathematics> More, required to be added; positive, as distinguished from negative; opposed to minus. 2. Hence, in a literary sense, additional; real; actual. "Success goes invariably with a certain plus or positive power." (Emerson) 3. <mathematics> Plus sign, the sign (+) which denotes addition, or a positive quantity. Origin: L, more; akin to Gr, and cf. Piu, Pleonasm. (11 Mar 1998) |
| plus lens | A converging lens. Synonym: plus lens. (05 Mar 2000) |
| plus strand | See: replicative form. (05 Mar 2000) |
| fluorescence plus Giemsa stain | <technique> A stain used to demonstrate sister chromatid exchange; cells are grown in 5-bromodeoxyuridine, followed by chromosome preparation, staining in Hoechst 33258, exposure to light, and staining in Giemsa; chromosomes exhibit a "harlequin" appearance. (05 Mar 2000) |
| prenatal | <obstetrics> Existing or occurring before birth, with reference to the foetus. Origin: L. Natalis = natal (18 Nov 1997) |
| prenatal care | Care provided the pregnant woman in order to prevent complications, and decrease the incidence of maternal and prenatal mortality. (12 Dec 1998) |
| prenatal diagnosis | Determination of the nature of a pathological condition or disease in the postimplantation embryo, foetus, or pregnant female before birth. (12 Dec 1998) |
| prenatal exposure delayed effects | Delayed effects on offspring of maternal or foetal prenatal exposure to drugs, radiation and other physical agents, manipulation, nutrition, stress, etc. (12 Dec 1998) |
| prenatal life | That interval of life between conception and birth; in humans, usually divided into embryonic and foetal periods. (05 Mar 2000) |
| prenatal screening | Screening for the detection of foetal disease, usually by ultrasound examination or by testing amniotic fluid obtained by amniocentesis. Other screening techniques include testing maternal serum and placental biopsy. (05 Mar 2000) |