Fetal vascular responses to maternal nicardipine administration in the hypertensive ewe.

Calcium channel blockers such as nicardipine act as arterial vasodilators and are effective in the treatment of hypertension. Although they are also effective tocolytic agents, fetal effects have not been fully studied. Fifteen chronically catheterized near-term ewes were studied.

The effect of magnesium sulfate tocolysis on the fetal biophysical profile.

The biophysical profile has proved to be a valuable tool for the assessment of fetal well-being, independent of gestational age. Magnesium sulfate is commonly used as a tocolytic agent, yet relatively little is known about its effects on the biophysical activities of the fetus. To investigate the effects of magnesium sulfate on the biophysical profile, we performed serial studies on patients who received tocolytic therapy with this agent because of preterm labor.

The effect of continuous epidural analgesia on cesarean section for dystocia in nulliparous women.

Epidural analgesia in labor is generally accepted as safe and effective and therefore has become increasingly popular. However, little is known regarding the effect of epidural analgesia on the incidence of cesarean section for dystocia in nulliparous women. During the first 6 months of 1987 we studied 711 consecutive nulliparous women at term, with cephalic fetal presentations and spontaneous onset of labor.

Routine umbilical cord blood gas determinations?

Between 1986 and 1988, 1924 term nulliparous patients with spontaneous onset of labor were studied to assess the importance of obtaining umbilical cord blood gas levels on all deliveries. The umbilical cord arterial and venous pH values (expressed as mean +/- 2 SD) were 7.24 +/- 0.

Fetal placental vascular responses to prostacyclin after angiotensin II-induced vasoconstriction.

The vasodilator prostacyclin is produced by many fetal tissues and may serve to protect umbilical placental blood flow. We hypothesized that prostacyclin could reverse fetoplacental vasoconstriction produced by angiotensin II (ANG II). Studies were done in eight unanesthetized near-term ovine fetuses.

Conservation of local electric fields in the evolution of Cu,Zn superoxide dismutase.

The trend of the electric field and the value of the electric field flux, sensed by the superoxide substrate in the proximity of the active site, were found to be constant in three highly homologous Cu,Zn superoxide dismutases from ox, pig and sheep, which display large differences in net protein charge and distribution of electrically charged surface residues but very similar catalytic rate constants. The spatial relationship of charges on the protein surface apparently has been conserved during the evolution of this enzyme to create electrostatic facilitation of catalysis.

Fetal vascular responses to prostacyclin.

Prostacyclin is a potent vasodilator produced by both maternal and fetal tissues that dilates the umbilical placental vasculature in vitro. To test the hypothesis that prostacyclin dilates the fetal placental circulation in vivo, we measured blood flow by the radioactive microsphere technique in six unanesthetized near-term ovine fetuses before and during prostacyclin infusion. Fetal mean arterial pressure fell 15% from 35 +/- 3 to 31 +/- 3 mm Hg (p less than 0.

Fetoplacental vascular responses to prostacyclin after thromboxane-induced vasoconstriction.

The vasodilator prostacyclin is produced by fetal tissues and may serve to protect umbilical blood flow. We hypothesized that prostacyclin could reverse fetoplacental vasoconstriction produced by a thromboxane mimic (U-46619). Fetal regional blood flow was measured by the radioactive microsphere technique in six unanesthetized, near-term ovine fetuses.

Cervical incompetence and preterm labor.

The ability of the cervix to function as a competent sphincter to retain the fetoplacental unit in utero until term is dependent on a complex set of biochemical, biophysical, and environmental events. The understanding of these interactions is limited at present and requires that cervical incompetence be a diagnosis of exclusion. Currently, differentiation of cervical incompetence from preterm labor is a major problem.

Effects of high-dose oxytocin augmentation on umbilical cord blood gas values in primigravid women.

Active management of labor for term primigravid women with singleton, vertex presentations is associated with significant decreases in incidence of cesarean section and duration of labor, without adversely affecting major perinatal outcome variables. Concern has been expressed that high-dose oxytocin augmentation may increase the incidence of fetal compromise. With active management of labor, 43% of 1423 primigravid women received high-dose oxytocin augmentation during an 11-month period.

Is the activity-linked electrostatic gradient of bovine Cu, Zn superoxide dismutases conserved in homologous enzymes irrespective of the number and distribution of charges?

Electrostatic potential calculations have been performed on three different Cu, Zn superoxide dismutases (superoxide: superoxide oxidoreductase, EC 1.15. 1.

Arachidonic acid metabolites and the regulation of placental and other vascular tone during pregnancy.

The eicosanoids are ubiquitous metabolites of arachidonic acid that possess an array of biological actions including marked vasoactivity. They are produced in significant quantities by the fetus, chorion, amnion, placenta, and maternal vascular tissues, and they have many important functions in the development and maintenance of normal vascular tone in human gestation. Imbalances in the production of certain eicosanoids may lead to failure of appropriate fetal growth and development, as well as to certain maternal vasoconstrictive disorders, such as preeclampsia.

The role of arachidonic acid metabolites in preeclampsia.

Preeclampsia is characterized by imbalances in the production rates of several arachidonic acid metabolites. There is a considerable amount of evidence to indicate that PGI2 production is decreased in preeclampsia. PGI2 is a potent vasodilator, an inhibitor of platelet aggregation, and an inhibitor of uterine contractility.

An overview of hydramnios.

Hydramnios, defined as a volume of amniotic fluid in excess of 2,000 mL, is frequently diagnosed in contemporary obstetric practice by ultrasound. A pocket of amniotic fluid in excess of 8 cm X 1 cm is a satisfactory upper limit of normal volume using ultrasound. The etiology of hydramnios is not clear cut, but there is a significant 20% association with fetal anomaly.

Short-term antibiotic therapy with clindamycin phosphate in patients with malignant epithelial tumors: an immunological evaluation.

The authors evaluated the results of a study using clindamycin phosphate plus gentamicin in short-term therapy in patients with tumors submitted to surgery for removal of the primary lesion. Only 6.6% of these patients became infected, and these good results are most likely due to the synergic activity of clindamycin with the physiological immune response.

Placental vascular responses to leukotriene receptor antagonist FPL 55712.

We have previously shown that FPL 55712, a specific leukotriene receptor antagonist, potentiates estrogen induced uterine hyperemia in nonpregnant rabbits. We therefore chose to investigate the vascular responses of pregnant rabbits to leukotriene blockade. Nine unanesthetized animals carrying 46 viable fetuses were used in this study.

Bacteria causing false positive test for phosphatidylglycerol in amniotic fluid.

A case is reported in which phosphatidylglycerol was detected in a sample of vaginal pool amniotic fluid but absent in amniotic fluid obtained at amniocentesis. Bacteria contaminating the fluid are shown to be capable of phosphatidylglycerol production.

Ovine placental vascular response to the local application of prostacyclin.

Rankin et al. have shown that prostacyclin does not dilate the ovine placenta, yet Clark et al. have shown that retrograde infusion of prostacyclin dilates the uterine vasculature.

The effect of prostacyclin on angiotensin II-induced placental vasoconstriction.

Significant alterations in vascular responsiveness to angiotensin II have been documented during pregnancy. We have observed that prostacyclin, a potent vasodilating prostaglandin, does not dilate the ovine placental vasculature. However, we thought it might modulate the placental vasoconstriction produced by angiotensin II.

A new technique for the selective intra-arterial chemotherapy in advanced cancer of the head and neck.

A new technique of selective intracarotid infusion is reported. This method involves the common and external carotid subcutaneous transposition. The advantages of this method are described.

The effect of a leukotriene receptor antagonist, FPL 55712, on estrogen-induced uterine hyperemia in the nonpregnant rabbit.

Estrogen results in delayed uterine hyperemia. We postulate that the leukotrienes may be the mediators of the uterine vascular responses to estrogen. To test this hypothesis, we gave FPL 55712, a selective leukotriene antagonist, to estrogen-primed, nonpregnant rabbits and measured regional blood flows by the radioactive microsphere technique.

Maturational sequence of the visual system: serial measurements of visual evoked potential and electroretinogram in the healthy neonatal lamb.

The value of measurements of visual evoked potential (VEP) for neurological assessment of the adult is widely accepted. Its use for neonatal evaluation following birth asphyxia has been limited by our knowledge of developmental changes occurring in the newborn brain. VEPs and electroretinograms (ERGs) were simultaneously recorded from five healthy newborn lambs from birth until 30 days of life.

Measurement of visual evoked potential in the asphyctic fetus and during neonatal survival.

Visual evoked potentials were measured in eight exteriorized near-term fetal lambs prior to and during 8 minutes of asphyxia and during 1 hour of newborn survival. Four of the lambs were then extubated, and measurements were continued while the lambs were observed for behavior and gross motor function. Early in the asphyctic period, marked changes in the visual evoked potential occurred in association with a fall in Po2, whereas during the postexposure period the visual evoked potential appeared to recover independently of cardiovascular or arterial blood gas values.

Birth asphyxia. I. Measurement of visual evoked potential (VEP) in the healthy fetus and newborn lamb.

The visual evoked potential (VEP) of five healthy, near-term exteriorized fetal lambs was compared with the VEP obtained from the same animals during the first hour after ventilation. Characteristics of the individual wave components and their relationship to blood pressure, heart rate, and arterial blood gas measurements concomitantly obtained were examined. Results show that the VEP of the healthy fetus is a stable, reproducible signal consisting of four basic components, and that the latencies (msec) and the amplitude (mu V) of the individual components of the VEP are similar to those of the newborn.