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Santos A C AC Department of Anesthesiology, Obstetrics and Gynecology, Albert Einstein College of Medicine/Montefiore Medical Center, Bronx, New York, - - 1997
The preterm fetal lamb that is exposed to clinically relevant plasma concentrations of lidocaine loses its cardiovascular adaptations to asphyxia, and its condition deteriorates further. Nitric oxide (NO) is an important regulator of vascular tone, and local anesthetics are known to inhibit endothelium-dependent vasodilation. The purpose of the present study ...
Moore J M - - 1997
A noninvasive perfusion method for the recovery of maternal placental (intervillous) blood for use in immunologic assays is described. 60% of the perfused blood samples tested for fetal red blood cell (RBC) contamination were found to be pure maternal blood; in the remainder, fetal RBC contamination, with a single exception, ...
Gruslin-Giroux A - - 1997
OBJECTIVE: Our purpose was to determine whether the restoration of fetal red blood cell mass after acute hemorrhage of 40% of the fetal blood volume is related to fetal plasma iron concentration. STUDY DESIGN: Ten chronically catheterized ovine fetuses were monitored for 10 days beginning at 125 +/- 1 (SE) ...
van Gemert M J - - 1997
OBJECTIVE: To propose a classification of twin-twin transfusion syndrome based upon three categories of placental anastomotic patterns. STUDY DESIGN: A mathematical model developed to compute fetal blood volume in monochorionic twins combines fetoplacental circulation with net fetofetal transfusion along placental anastomoses. We included (1) unequal cotyledonic sharing, assuming that smaller ...
Dowell R T - - 1997
The present studies were conducted to develop experimental methods for obtaining cardiovascular measurements in conscious, pregnant rats. Methods were then used to establish key quantitative measurements of (a) placental and fetal development, (b) maternal hemodynamics and (c) uteroplacental blood flow throughout gestation. A progressive and significant enhancement in fetal weight ...
Champsaur G - - 1997
OBJECTIVE: This study was initiated to test the hypothesis that fetal hemodynamic changes observed under pulsatile flow bypass might be related to the release of endothelium-derived relaxing factor through oscillating shear stress. METHODS: Normothermic bypass was instituted in utero in 21 preterm fetal lambs for a 1-hour period through the ...
Barrett J F - - 1997
This study investigates the hypothesis that following an intrauterine, intravascular transfusion (IVT), one of the physiologic adaptations might be an increase in the fetal urine production. The hourly fetal urine production rate (HFUPR) was measured for the first hour following 12 transfusions and for 24 h following 5 transfusions in ...
Estella N M - - 1997
BACKGROUND: Placenta percreta can create life-threatening hemorrhage at the time of delivery. The additional challenge of patient refusal of blood transfusion for religious reasons requires the use of comprehensive blood-conserving strategies. CASE: A Jehovah's Witness with two previous cesarean deliveries and a placenta previa was diagnosed antenatally as having placenta ...
Dubiel M - - 1997
The aim of this study was semiquantitative evaluation of tissue blood flow in the fetal lung before and after administration of betamethasone. This was carried out by means of computer analysis of ultrasound Doppler signals obtained by the color Doppler energy (CDE) technique. CDE signals were recorded in 20 singleton ...
van Bel F - - 1997
Nitric oxide (NO) influences cerebral vascular tone both in the normal fetus and in the hypoxemic fetus, but during postnatal life this regulating role of NO seems less prominent. It is therefore possible that under conditions when arterial oxygen content is at postnatal levels NO exerts no action on smooth ...
Carlan S J - - 1997
The objective of this paper is to determine the effect of maternal blood contamination on the TDx-FLM II assay for fetal lung maturation. Thirty-one samples of amnionic fluid (AF) collected from gestations > 28 weeks were assayed for AF surfactant-to-albumin ratio using the TDx-FLM II assay. Maternal blood was added ...
Itoh S - - 1997
The purpose of this study was to assess the effects of changes in fetal PaCO2 on circulatory functions without maternal influences. In 5 goat fetuses that were incubated using an extrauterine incubation system with arteriovenous extracorporeal membrane oxygenation, fetal carotid arterial blood flow, heart rate, mean blood pressure, and serum ...
Ogur G - - 1997
This study aimed to set up a practical lab-side approach to discriminate fetal from maternal blood in samples obtained by cordocentesis. To determine the fetal origin of the blood, a modified Apt test was applied to 30 cases of prenatal diagnosis. A change of colour of the fetal and adult ...
Tan W - - 1997
We have developed a method for measuring regional blood flow by means of fluorescent microspheres in all organs and tissues of the fetal lamb, including brain, heart, lung, liver, gut, spleen, kidney, adrenal, brown fat, skin, muscle, bone, and placenta. Five different fluorescent-labeled microspheres were used: blue (B), yellow-green (Y), ...
Sohda S - - 1997
The purpose of this study was to determine the proportion of fetal nucleated red blood cells (NRBCs) among enriched NRBCs and to evaluate the effectiveness of enriching NRBCs in maternal blood using fluorescence-activated cell sorting (FACS) to separate NRBCs. The origin of enriched NRBCs was determined using fluorescence in situ ...
Meekins J W - - 1997
During the first trimester in normal human pregnancy, endovascular trophoblast migrate along the decidual spiral arteries and invade their walls to produce physiological change. There is controversy as to whether invading trophoblast plug the arteries and prevent blood flow into the intervillous space. Using light microscopy, placental bed sections from ...
Egberts J - - 1997
OBJECTIVE: To determine the proportional reduction per day in the number of fetal and donor red blood cells from the fetal circulation after intrauterine intravascular transfusions. DESIGN: A retrospective study of 302 transfusions in 101 fetuses. SETTING: The Department of Obstetrics and Gynaecology of the University Medical Centre Leiden, The ...
Abzug M J - - 1997
Maternal factors that might impair the integrity of the late gestation placental barrier to enteroviruses were evaluated. Mice were inoculated with Theiler's murine encephalomyelitis virus (TMEV) on day 10-13 of gestation and sacrificed on day 16-18. Placentas and fetuses from dams with advanced age, forced daily swimming, short-term clamping of ...
Hedriana H L - - 1997
OBJECTIVES: To determine whether physiological increases in fetal plasma arginine vasopressin (AVP) concentration alter blood flow rates to the ovine chorion, amnion or placenta, and to determine whether these AVP-induced changes in flow are dependent on gestational age. METHODS: Colored microspheres (15.10 +/- 0.02 microns (standard deviation) were infused into ...
Rebello C M - - 1997
We evaluated postnatal lung function and intravascular albumin loss to tissues of 123-days-gestation preterm surfactant-treated and ventilated lambs 15 h after direct fetal (n = 8) or maternal (n = 9) betamethasone treatment or saline placebo (n = 9). The betamethasone-treated groups had similar increases in dynamic compliances, ventilatory efficiency ...
Gagnon R - - 1997
The purpose of this study was to determine the endocrine and circulatory responses of the ovine fetus, near term, to sustained hypoxemic stress superimposed on chronic hypoxemia. Fetal sheep were chronically embolized (n = 7) for 10 days between 0.84 and 0.91 of gestation via the descending aorta until arterial ...
Kalache K D - - 1997
Our aim was to determine if it was technically possible to assess fetal tracheal fluid flow during fetal breathing movements, and to compare the data obtained with those recorded in the fetal nasopharynx. Tracheal and nasal fluid flow was analyzed in ten uncomplicated pregnancies, the gestational age ranging between 28 ...
Blea C W - - 1997
OBJECTIVE: Our purpose was to determine whether the fetal acidosis and hypoxia previously demonstrated in animal models with maternal nifedipine infusion is the result of a decrease in uteroplacental or fetoplacental blood flow and whether this effect is exacerbated by a higher drug concentration and duration of infusion. STUDY DESIGN: ...
Macpherson M L - - 1997
OBJECTIVE: To compare effects of 3 oxytocin-based induction techniques on fetal and neonatal foals. DESIGN: Prospective randomized controlled trial. ANIMALS: 16 pregnant mares. PROCEDURE: Parturition was induced in mares by use of 3 treatments: group 1, 75 U of oxytocin, IM; group 2, 15 U of oxytocin, IM, q 15 ...
Hanson M A - - 1997
Fetal well-being depends on the level of oxygenation in vital organs such as the heart and brain. In this review, we discuss the physiological parameters which underlie the use of pulse oximetry to evaluate fetal conditions intrapartum. Whilst the measurement of haemoglobin oxygen saturation (SaO2) depends on partial pressure of ...
Bootstaylor B S - - 1997
OBJECTIVES: We previously demonstrated effective tocolysis with nitroglycerin in laboring sheep. In this study we evaluated maternal and fetal circulatory effects of nitroglycerin. STUDY DESIGN: Vascular catheters and an umbilical Doppler flow transducer were placed in eight ewes. Nitroglycerin was infused maternally over 30 minutes at 1.5, 2.5, 5.0, and ...
Butterwegge M - - 1997
The aim of the study is to assess the continuous monitoring of fetal blood oxygen saturation (SpO2) during labour using a fetal pulse oximeter in cases of abnormal fetal heart rate (FHR). To determine whether pulse oximetry has the potential to replace scalp blood pH sampling in infants with abnormal ...
Izumi A - - 1997
OBJECTIVE: To evaluate the accuracy of a new pulse oximeter in estimating the oxyhemoglobin (O2Hb) concentration in fetal arterial blood (SaO2) with either a high concentration of hemoglobin F (HbF) or a low concentration of O2Hb during labor. PATIENTS AND METHODS: Fetal forehead arterial oxygenation was determined in 44 fetuses ...
Fisher R A - - 1997
The purpose of this study was to determine the genetic origin of a series of seven diploid hydatidiform moles with fetal red blood cells in the molar villi, normally a characteristic feature of triploid, partial hydatidiform moles. DNA was prepared from formalin-fixed, paraffin-embedded blocks of molar tissue and blood from ...
Lim T H - - 1997
The effects of extracts of Bufo marinus toad skin toxin on human isolated umbilical arterial rings and the fetal vessels of perfused placentae were examined and compared with those of ouabain, an inhibitor of Na+/K(+)-ATPase. Umbilical artery rings and fetal vessels of the perfused placenta responded to extracts, or ouabain, ...
Giroux M - - 1997
The placental transfer of three opioids used in peridural analgesia, fentanyl, alfentanil and sufentanil, and two reference substances, antipyrine and *H2O, was determined ex vivo in the human placental cotyledon system. (1) In the first set of experiments, the infusion rates were constant and fixed at physiological flow rates. Under ...
Giles W - - 1997
OBJECTIVE: To evaluate the effect of nitric oxide synthase activity inhibition on the fetal lamb umbilical artery flow velocity waveform. METHODS: Five pregnant Corriedale cross ewes were operated on at 125-130 days' gestation. Fetal and maternal vascular catheters were inserted along with a Doppler flow meter cuff on the fetal ...
de Haan H H - - 1997
OBJECTIVE: Our purpose was to investigate (1) the safety of fetal magnesium sulfate treatment and (2) possible beneficial effects on the brain during perinatal asphyxia. STUDY DESIGN: In 20 chronically instrumented fetal lambs (gestational age 125.8 +/- 3.5 days) four total umbilical cord occlusions for 5 minutes were repeated at ...
Ries M - - 1997
The blood fibrinolytic system essentially consists of proteolytic enzyme activation processes leading to the formation of the fibrin-degrading enzyme plasmin. It is thus the counterpart of the blood coagulation system. It differs physiologically in newborns compared with adults. In newborns, the plasma levels of plasminogen, the inactive plasmin precursor, are ...
McCrabb G J - - 1997
Our aim was to determine the effects of 12 h of hypoxaemia on cerebral blood flow (CBF) and cerebral O2 delivery in ovine fetuses at 0.6 gestation. During fetal hypoxaemia, induced by reduced uterine blood flow, fetal SaO2 and PaO2 were reduced (p < 0.01) from control values of 77.0 ...
Pooh R K - - 1996
Using transvaginal B-mode sonography combined with power Doppler flow mapping on a total of 65 fetuses between 12 and 30 weeks of gestation, fetal intracerebral arteries and veins and blood flow were demonstrated in the coronal and sagittal planes. Clear images of the fetal brain and intracerebral vascular flow were ...
Kaufmann P - - 1996
Placental fibrinoids are extracellularly deposited materials which are histologically glossy and acid staining, and can be found in every normal and pathological placenta at all stages of pregnancy. The amount of fibrinoid is, in general, independent of pregnancy outcome and fetal wellbeing. According to new findings, the classical histological term ...
Forestier F - - 1996
Fetal blood sampling is a widely used technique for both diagnostic and therapeutic purposes. However, despite the fact that examination of blood smears is a critical step in the study of a large variety of disorders, the place of fetal blood smears analysis has been overshadowed by more sophisticated diagnostic ...
Hasan S U - - 1996
To investigate the effects of lung distension and oxygenation on umbilical blood flow (UBF) and plasma prostaglandin E2 (PGE2) in relation to arousal and stimulation of breathing movements, we studied eight chronically instrumented, unanesthetized fetal sheep between 137 and 143 d of gestation. Electrocorticogram, electro-oculogram, nuchal and diaphragmatic electromyograms, arterial ...
Moraga F - - 1996
We compared blood oxygen affinity (P50) and hemoglobin concentration among fetal and maternal llamas and sheep, as respective examples of species native to high and low altitudes. P50, hemoglobin concentration and blood oxygen content were determined at sea level in 16 pregnant llamas, 6 pregnant sheep and their respective fetuses. ...
Stonestreet B S - - 1996
OBJECTIVES: Fetuses of diabetic women exhibit hypoxemia, elevated catecholamine concentrations at birth, and increased incidence of death. Our previous findings suggested that experimental fetal hyperinsulinemia results in a surge in catecholamines with cardiovascular changes supported by increased beta-adrenergic activity. The present experiments were designed to assess the contribution of alpha-adrenergic ...
Ley D - - 1996
Measurements of fetal aortic blood flow velocity and fetal growth were performed in 178 pregnancies. In 87 cases, the estimated fetal weight was > or = 2 SD below the gestational age-related mean of the population. Three fetuses died in utero. In 149 children (85%), a neurological examination was performed ...
Schneider T J - - 1996
OBJECTIVE: To determine placental transfer of ketanserin and to assess the effect of serotonin-2 receptor blockade by ketanserin on serotonin- and phenylephrine-induced vasoconstriction. STUDY DESIGN: Five chronically instrumented pregnant ewes at 120 days gestation were injected with 20 mg ketanserin i.v., and fetal and maternal arterial samples were obtained at ...
Sturgiss S N - - 1996
Previous reports have suggested that fetal blood sampling from the intrahepatic vein is not associated with significant fetal hepatic injury. We report a case of fetal liver necrosis occurring 24 h following blood sampling from the intrahepatic vein of a fetus with severe growth retardation at 34 weeks. The placenta ...
Clarke L - - 1996
We investigated the effect of a beta 3-adrenergic agonist, Zeneca D7114, on thermoregulation in near-term lambs delivered by cesarean section. Lambs were delivered into a cool ambient temperature of 15 degrees C, and between 60 and 80 min of life were given an oral dose of Zeneca D7114 (10 mg.kg ...
Reddy V M - - 1996
BACKGROUND: Progressive metabolic acidosis, hypoxia, and hypercarbia develop rapidly after fetal cardiac bypass mainly as a result of an increase in placental vascular resistance and a decrease in placental blood flow. A number of factors including fetal stress, priming substances, and extracorporeal surfaces have been identified as possible stimuli causing ...
Badalian S S - - 1996
Our aim was to identify patterns of fetal perinasal fluid flow, and to determine the relationship of pattern of flow to the diaphragmatic component of fetal breathing movements. Twenty-four fetuses were studied with the use of two ultrasound systems simultaneously. Continuous video-tape records of the color and spectral Doppler imaging ...
Walker V - - 1996
Severe birth asphyxia leads to a transient organic aciduria and increased hypoxanthine excretion. To investigate its origin and timing, we analyzed urine from 12 late gestation fetal sheep in utero subjected to moderately severe isocapnic hypoxia for 1 h. In six fetuses the carotid sinus nerves were cut to determine ...
Wachtel S S - - 1996
Fetal blood cells can be recovered from the maternal circulation by charge flow separation (CFS), a method that obviates the risks associated with amniocentesis and chorionic villus sampling. By CFS, we processed blood samples from 13 women carrying male fetuses, 2 carrying fetuses with trisomy 21, and 1 who had ...
Richardson B - - 1996
To determine the circulatory response of the preterm fetus to a sustained hypoxic insult, regional blood flow was measured (microsphere technique) in 12 unanesthetized fetal sheep (0.75 gestation) during a normoxic control period, after 1 h and 8 h of sustained hypoxemia, and after a 1-h recovery period. Associated endocrine ...
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