Browsing by Author "Valenzuela, GJ"

Now showing 1 - 4 of 4
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    Bile acids increase response and expression of human myometrial oxytocin receptor
    (MOSBY, INC, 2003) Germain, AM; Kato, S; Carvajal, JA; Valenzuela, GJ; Valdes, GL; Glasinovic, JC
    OBJECTIVE: We tested the hypothesis that during intrahepatic cholestasis of pregnancy bile acids activate the myometrial oxytocin receptor pathway.
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    Effect of constant light on fetal and maternal prolactin rhythms in sheep
    (1996) Parraguez, VH; Valenzuela, GJ; Vergara, M; Ducsay, CA; Yellon, SM; SeronFerre, M
    A 24-h rhythm of plasma PRL is present in fetal sheep. This rhythm is synchronized to an environmental clue (zeitgeber). We determined whether the light-dark cycle (L:D) is a zeitgeber for the fetal PRL rhythm and, if so, whether the mother might convey this zeitgeber to the fetus. We kept nine ewes (twin pregnancies) in constant light (L:L) and five ewes (singleton) in 14:10 L:D from 110 days gestation. Fetuses and mothers were catheterized at 119 days gestation. Blood samples were taken hourly for 24 h after 16 days under L:L or L:D. A mean 24-h rhythm of PRL was found (by RIA) in fetuses under L:D, but not in those under L:L. However, fetuses under L:L showed individual 24-h PRL rhythms (cosinor analysis) whose acrophases were distributed around the clock. Nonsynchronized rhythms persisted after 23 and 30 days of L:L. Acrophases of PRL rhythms within a set of twins were closer than those between sets, suggesting that twins were responding to a common signal. These findings indicate that the L:D cycle is a zeitgeber for the PRL rhythm in fetal sheep and suggest that the mother might convey the zeitgeber.
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    Preterm labor: Placental pathology and clinical correlation
    (LIPPINCOTT WILLIAMS & WILKINS, 1999) Germain, AM; Carvajal, J; Sanchez, M; Valenzuela, GJ; Tsunekawa, H; Chuaqui, B
    Objective: To determine the relevance of ischemia in the incidence of preterm labor. A second objective was to document perinatal outcomes for patients with preterm labor classified according to its clinical, functional, and pathologic characteristics (infectious, ischemic, mixed, or idiopathic).
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    Twenty-four-hour pattern of cortisol in the human fetus at term
    (2001) Serón-Ferré, M; Riffo, R; Valenzuela, GJ; Germain, AM
    OBJECTIVES: Indirect evidence suggests that adrenal steroid production in the human fetus may have a circadian rhythm. To assess whether there is a 24-hour rhythm of fetal cortisol in the human fetus, we investigated the relationship between fetal and maternal cortisol and cortisone concentrations in maternal, umbilical arterial, and umbilical venous blood samples over a 24-hour period.