Medical Dictionary Definitions A-Z List
Medical Dictionary Definitions A - Z - «P»:
Pregnancy-associated plasma protein A
Pregnancy-associated plasma protein A: Abbreviated as PAPPA or PAPP-A. A large zinc-binding protein that acts as an enzyme, specifically a metallopeptidase. The gene for PAPPA is in chromosome band 9q33.1. PAPPA has been used in prenatal genetic screening and studies of atherosclerosis. Women with l...
Pregnant: The state of carrying a developing fetus within the body.
The word "pregnant" comes from the Latin pre- meaning before + (g)natus meaning birth = before (giving) birth. The word "prenatal" has exactly the same origin....
Prehypertension: A systolic pressure of 120 to 139 mm Hg or a diastolic pressure of between 80 and 89 mm Hg. Prehypertension is a precursor to chronic high blood pressure. Lifestyle changes are therefore recommended for anyone with prehypertension....
Preleukemia: A condition in which the bone marrow
does not produce enough blood cells. This condition may progress to
become acute leukemia. Preleukemia also is called myelodysplastic
syndrome or smoldering leukemia....
Prelingual: Before the development of speech and language. "She showed that in prelingually deaf people (that is, those who had been born deaf or become deaf before the age of two or so), the auditory parts of the brain had not degenerated or atrophied." (From The Mind's Eye, by Oliver Sacks, The Ne...
Premacular fibrosis: See: Macular pucker....
Pertaining to tissue that is not yet malignant, but is poised to become malignant. Appropriate clinical and laboratory studies are designed to detect premalignant tissue while it is still in a premalignant stages. A large battery of techniques are generally available to remove or kil...
Premature baby: A baby born before 37 weeks of gestation have passed. Historically, the definition of prematurity was 2500 grams (about 5 1/2 pounds) or less at birth. The current World Health Organization definition of prematurity is a baby born before 37 weeks of gestation, counting from the first...
Premature beat: See: Extrasystole....
Premature birth: A birth that takes place before 37 weeks of gestation have passed. Historically, the definition of prematurity was 2500 grams (about 5 1/2 pounds) or less at birth. The current World Health Organization definition of prematurity is a baby born before 37 weeks of gestation, counting ...
Premature contraction: See: Extrasystole....
Premature contraction of the heart
Premature contraction of the
heart: When a single
heartbeat occurs earlier than normal. This phenomenon can be within normal limits or
represent a medically significant arrhythmia. ...
Premature ejaculation: Premature ejaculation is ejecting semen from the penis, usually accompanied by orgasm occurring sooner than a man wishes during sexual activity. Premature ejaculation is
characterized by a lack of voluntary control over ejaculation that interferes with optimal sexual or psyc...
Premature systole: See: Extrasystole....