(DOWNLOAD) "Increased Concentrations of Prostate-Specific Antigen in Maternal Serum from Pregnancies Affected by Fetal Down Syndrome (Enzymes and Protein Markers)" by Clinical Chemistry ~ Book PDF Kindle ePub Free
eBook details
- Title: Increased Concentrations of Prostate-Specific Antigen in Maternal Serum from Pregnancies Affected by Fetal Down Syndrome (Enzymes and Protein Markers)
- Author : Clinical Chemistry
- Release Date : January 01, 1998
- Genre: Chemistry,Books,Science & Nature,
- Pages : * pages
- Size : 202 KB
Description
Down syndrome (trisomy 21) is one of the most common causes of mental retardation in the industrialized world, with a birth prevalence of 1 in 700. The prenatal identification of fetuses with Down syndrome by maternal serum screening has become a part of routine obstetrical care. In prenatal screening, maternal serum concentrations of secretory products of the fetoplacental unit in combination with maternal age are used to determine a woman's risk of having a fetus affected with Down syndrome. On average, second-trimester concentrations of alpha-fetoprotein (AFP)[4] and unconjugated estriol (uE3) are low, and concentrations of human chorionic gonadotropin (hCG) and its free (3-subunit are high in Down syndrome pregnancy [1-4]. Use of various combinations of these markers results in a detection rate of 55-75% at a 5% false-positive rate [5, 6]. Efforts are being made to improve prenatal screening; the addition of maternal serum inhibin A, for example, has been found to increase detection by 7-22% [7,8]. Prostate-specific antigen (PSA), although conventionally considered a specific marker for prostate epithelial cells [9], recently has been measured in female tissue extracts and fluids by an ultrasensitive assay [10-12]. Serum PSA concentrations are higher in pregnant women than in healthy nonpregnant women, and amniotic fluid PSA concentrations increase between gestational weeks 11 and 21 [13,14]. These data are consistent with a potential role of PSA in fetal growth. Although a placental origin of PSA during pregnancy has not yet been investigated, possible sources of maternal serum PSA may include diffusion from amniotic fluid, production by the periurethral glands [15-17], and secretion from breast tissue in response to steroid stimulation during pregnancy [18].