| minerals | Native, inorganic or fossilised organic substances having a definite chemical composition and formed by inorganic reactions. They may occur as individual crystals or may be disseminated in some other mineral or rock. (12 Dec 1998) |
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| 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) |
| ultrasonography, prenatal | The visualization of tissues during pregnancy through recording of the echoes of ultrasonic waves directed into the body. The procedure may be applied with reference to the mother or the foetus and with reference to organs or the detection of maternal or foetal disease. (12 Dec 1998) |
| folic acid | <biochemistry> Pteridine derivative that is abundant in liver and green plants and is a growth factor for some bacteria. The biochemically active form is tetrahydrofolate (see folate). (12 Nov 1997) |
| folic acid antagonist | <pharmacology> A chemical which inhibits a cells capacity to use folic acid and so prevent cell division, for example methotrexate. See: chemotherapy. (12 Nov 1997) |
| folic acid antagonists | Inhibitors of the enzyme, dihydrofolate reductase (tetrahydrofolate dehydrogenase), which converts dihydrofolate (fh2) to tetrahydrofolate (fh4). They are frequently used in cancer chemotherapy. (12 Dec 1998) |
| folic acid conjugate | A folate with three molecules of glutamic acid (pteropterin) instead of one, or with seven (pteroylheptaglutamic acid or vitamin Bc conjugate). (05 Mar 2000) |
| folic acid deaminase | <enzyme> Chemotaxis regulating enzyme; splits folic acid into 6-hydroxymethylpterin and p-aminobenzoylglutamic acid Registry number: EC 3.5.4.- Synonym: folic acid inactivating enzyme, folic acid c9-n10 cleaving enzyme (26 Jun 1999) |
| folic acid deficiency | A nutritional condition produced by a deficiency of folic acid in the diet. Many plant and animal tissues contain folic acid, abundant in green leafy vegetables, yeast, liver, and mushrooms but destroyed by long-term cooking. Alcohol interferes with its intermediate metabolism and absorption. Folic acid deficiency may develop in long-term anticonvulsant therapy or with use of oral contraceptives. This deficiency causes anaemia, macrocytic anaemia, and megaloblastic anaemia. It is indistinguishable from vitamin b 12 deficiency in peripheral blood and bone marrow findings, but the neurologic lesions seen in b 12 deficiency do not occur. (merck manual, 16th ed) (12 Dec 1998) |
| folic acid deficiency anaemia | Anaemia due to deficiency of folic acid, characterised by large-sized red blood cells (macrocytosis) and presence of large nuclei in erythroid precursor cells (megaloblasts) in the bone marrow. (05 Mar 2000) |