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Biomedical subjects

F R Moya

Publications and source records attributed to F R Moya.

33 records · Page 2Linked to original sources
PubMed1993

Erythropoietin in human fetuses with immune hemolytic anemia and hydrops fetalis.

OBJECTIVE: To determine whether plasma erythropoietin is increased in fetuses with anemia due to Rh isoimmunization. METHODS: Hemoglobin and erythropoietin were measured in samples obtained by funipuncture from 15 fetuses with Rh isoimmunization (gestational age 26.2 +/- 5.0 weeks, mean +/- standard deviation) and from 13 control fetuses (23.1 +/- 6.7 weeks). Hemoglobin and erythropoietin also were determined in umbilical cord blood collected at birth from 20 term fetuses delivered by elective cesarean. RESULTS: Fetuses with Rh isoimmunization had lower hemoglobin and higher plasma erythropoietin measurements than mid-gestation controls (6.1 +/- 3.9 versus 10.7 +/- 1.5 g/dL and 105.5 +/- 168.1 versus 12.5 +/- 3.1 mU/mL, P < .05, respectively). Hemoglobin and plasma erythropoietin increased with gestational age in control fetuses. There was an inverse association between hemoglobin and plasma erythropoietin in control and Rh-isoimmunized fetuses (r = -0.56, P < .005). Using multiple linear regression, hemoglobin and gestational age were associated independently with plasma erythropoietin (overall F2,25 = 12.3, multiple r2 = 0.49, P < .001). Despite marked decreases in hemoglobin, fetuses below 24 weeks' gestation had minimal increases in plasma erythropoietin compared to fetuses above that gestational age. Mildly anemic Rh-isoimmunized fetuses (hemoglobin 11.6 +/- 2.0 g/dL) delivered vaginally had significantly higher erythropoietin levels in umbilical cord plasma than Rh-isoimmunized fetuses with comparable hemoglobin (10.9 +/- 3.5 g/dL) delivered by elective cesarean without labor (1246 +/- 856 versus 106 +/- 66 mU/mL, respectively, P < .05). CONCLUSION: Fetuses with anemia at mid to late gestation respond with increases in plasma erythropoietin, but these changes are substantially attenuated before 24 weeks' gestation.

Anemia, Hemolytic, Autoimmune↗
PubMed1992

Respiratory disease in very-low-birthweight infants after prenatal thyrotropin-releasing hormone and glucocorticoid. TRH Study Group.

Although prenatal glucocorticoid treatment reduces neonatal respiratory morbidity, respiratory distress syndrome and chronic lung disease (CLD) develop in many very-low-birthweight infants despite therapy. To investigate the effect of additional prenatal treatment with thyrotropin-releasing hormone (TRH), we did a multicentre, blinded, randomised trial. 404 women with threatened preterm delivery at less than 32 weeks' gestation received betamethasone plus TRH (4 doses of 400 micrograms 8-hourly) or betamethasone plus placebo. 103 infants who were fully treated and of less than 1500 g birthweight were evaluated during the neonatal period. TRH treatment (55 infants) did not affect the total incidence of respiratory distress syndrome (47% vs 58% in controls) or of severe respiratory distress syndrome (13% vs 25% in controls, p = 0.11). CLD (defined as requirement for supplemental oxygen at 28 days after birth) developed in significantly fewer TRH-treated infants (18% vs 44% of controls, p less than 0.01). The unadjusted relative risk of CLD with TRH therapy was 0.40 (95% CI 0.26-0.80, p less than 0.05), and this was not materially changed after adjustment for potentially modifying variables. There were significantly fewer adverse outcomes, defined as death or continuing oxygen requirement, in the TRH group than in the steroid-alone group both at 28 days and when infants reached 36 weeks' postconceptional age. The incidence of other complications of prematurity was similar in the two groups. Prenatal TRH reduces the incidence of chronic lung disease among betamethasone-treated infants.

Betamethasone↗
PubMed1992

Plasma thyroid hormones and prolactin in premature infants and their mothers after prenatal treatment with thyrotropin-releasing hormone.

We assayed TSH, triiodothyronine, free thyroxine, and prolactin (PRL) in plasma of women and infants participating in a trial of prenatal thyrotropin-releasing hormone (TRH) treatment for prevention of newborn lung disease. Women in labor at 26-34 wk of gestation received 400 micrograms of TRH i.v. every 8 h (one to four doses) plus 12 mg betamethasone (one or two doses); controls received saline plus betamethasone. Mean cord concentrations in control infants were TSH 9.7 mU/L, triiodothyronine 0.6 nmol/L (40.2 ng/dL), free thyroxine 14.4 pmol/L (1.13 ng/dL), and PRL 67.6 micrograms/L. TRH increased maternal plasma TSH by 100% at 2-4 h after treatment and decreased levels by 28-34% at 5-36 h. In cord blood of treated infants delivered at 2-6 h, TSH, triiodothyronine, and PRL were all increased about 2-fold versus control, and free thyroxine was increased 19%; the response was similar after one, two, three, or four doses of TRH. In treated infants delivered at 13-36 h, cord TSH and triiodothyronine levels were decreased 62 and 54%, respectively, and all thyroid hormones were lower after birth at 2 h of age versus control. We conclude that prenatal TRH administration increases thyroid hormones and PRL in preterm fetuses to levels similar to those normally occurring at term. Pituitary-thyroid function is transiently suppressed after treatment to a greater extent in fetus than mother, and infants born during the early phase of suppression do not have the normal postnatal surge in thyroid hormones.

Betamethasone↗
PubMed1992

Effects of betamethasone and thyroid hormone on fetal rat lung maturation in vivo.

We studied the effect of maternal administration at various intervals of betamethasone, triiodothyronine (T3), or both, on fetal rat lung maturation. T3 alone did not enhance choline incorporation to phosphatidylcholine by 20-day fetal lung explants, or morphometric lung maturation. Betamethasone, and betamethasone plus T3, increased both of those parameters over control and T3 values. However, addition of T3 offered no advantage over administration of betamethasone alone. Significant enhancement of morphometric lung maturation was already present after only 24 h of exposure to beta-methasone, or to the combination of hormones. However, choline incorporation to phosphatidylcholine only increased significantly by 36 h of exposure to betamethasone with or without T3.

Animals↗
PubMed1990

Atrial natriuretic factor in hydrops fetalis caused by Rh isoimmunisation.

Plasma concentrations of atrial natriuretic factor were determined by radioimmunoassay in 16 human fetuses of between 19 and 38 weeks' gestation. Fifteen fetuses had varying degrees of anaemia as a result of Rh isoimmunisation, and one fetus was normal. Eight fetuses had ultrasonographic evidence of severe hydrops fetalis and an additional three fetuses had mild hydrops. Severely hydropic fetuses were more anaemic and immature than those with mild or no hydrops. Among fetuses from which samples were taken before in utero transfusion, concentrations of atrial natriuretic factor were higher in those with severe hydrops than in the other groups. An inverse relationship between the haemoglobin concentration and that of atrial natriuretic factor was found. In four fetuses in which severe hydrops resolved after intravascular transfusions in utero, there were significant decreases in plasma atrial natriuretic factor concentrations; in the fifth fetus the decrease was less pronounced. Raised concentrations of atrial natriuretic factor in fetuses with severe anaemia and hydrops may be the result of atrial natriuretic factor release induced by hypoxia.

Atrial Natriuretic Factor↗
PubMed1989

Survival of infants with persistent pulmonary hypertension without extracorporeal membrane oxygenation.

A retrospective evaluation was performed of the survival after conservative therapy of infants with persistent pulmonary hypertension who met the published criteria of Bartlett et al (Pediatrics. 1985;76:479-487) or Short et al (Clinics in Perinatology. 1987;14:737-748) for extracorporeal membrane oxygenation (ECMO) therapy. An 80% to 90% mortality rate can be predicted with these criteria, which are based on historical data, if ECMO is not used. The records of infants with the diagnosis of persistent pulmonary hypertension, weighing greater than 2 kg at birth and who were treated during two time periods, January 1980 to December 1981 [23 patients] and January 1986 to December 1988 [17 patients], were reviewed. During the earlier period, hyperventilation was the mainstay of our therapy, whereas during the later period, a more conservative approach (avoidance of hyperventilation) was adopted. In 1980 to 1981, 1 of the 6 patients (17%) who were eligible for ECMO by criteria of Bartlett et al survived, which is consistent with the published data. However, in 1986 to 1988, 9 of 10 ECMO-eligible patients (90%) survived (P less than .02). The corresponding survival figures using the alveolar-arterial oxygen difference criteria of Short et al were 0 of 5 survivors (0%) in 1980 to 1981 and 8 of 9 (89%) in 1986 to 1988 (P less than .006). These data indicate that approximately 90% of patients who are candidates for ECMO now survive in our institution without the use of that therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Birth Weight↗
PubMed1988

The reversal of hydrops fetalis by intravascular intrauterine transfusion in severe isoimmune fetal anemia.

Seventy-two intrauterine intravascular transfusions were performed on 26 patients with severe erythroblastosis fetalis. Twenty of the 26 fetuses were hydropic at the time of referral. Of the 20 hydropic fetuses, 16 (80%) survived. Hydrops was completely reversed in 13 of the 16 fetuses (81%). Total protein of less than 3 gm/dl, albumin less than 2 gm/dl, and a hematocrit level of less than 15% were associated with hydrops fetalis. After hydrops was reversed, total protein greater than 3 gm/dl, albumin greater than 2 gm/dl, along with a sustained hematocrit level of greater than 15%, were found. Only three neonates were born with minimal ascites, two of whom had had intraperitoneal transfusions before intravascular treatments. There were 21 survivors of the total group, giving an overall survival rate of 82%. There was one neonatal death from severe respiratory distress syndrome. Thirty-eight percent of the neonates did not require exchange transfusions in the newborn period. Intrauterine intravascular transfusions appear to be an effective mode of therapy in severe erythroblastosis fetalis and not only increase survival rates but also decrease neonatal morbidity and mortality.

Adult↗
PubMed1988

Late closure of the ductus arteriosus using indomethacin in the preterm infant.

Several studies have shown a lack of effect of indomethacin therapy for the closure of a patent ductus arteriosus (PDA) in premature infants over 14 days of postnatal age. In this report we describe two cases in which a hemodynamically significant PDA was closed with indomethacin in preterm infants over 20 days of age. The response to indomethacin may be more related to postconceptual age than to actual postnatal age. We suggest that intravenous indomethacin therapy should be attempted before surgical ligation is performed in those premature infants under 34 weeks postconceptual age who have a hemodynamically significant patent ductus arteriosus.

Ductus Arteriosus, Patent↗
PubMed1988

Prevention of respiratory distress syndrome.

RDS continues to be a major problem for premature infants despite a better understanding of its pathophysiology and of ways to try to prevent it. To date, prenatal administration of glucocorticoids has been the most widely used method of accelerating fetal lung development. However, several limitations of this therapy have prompted the search for alternative approaches. Most efforts have focused on the potential use of combined hormonal therapy with glucocorticoids and either thyroid hormones or TRH. The easy transplacental passage of the latter tends to favor its use. The use of hormonal therapy prenatally and surfactant administration at birth appears currently to be the best approach to prevent RDS. The greatest benefit would clearly come from the prevention of prematurity (Fig 1), but this has not proved to be an easy task.

Adrenal Cortex Hormones↗
PubMed1987

Betamethasone increases pulmonary compliance in part by surfactant-independent mechanisms in preterm rabbits.

Antenatal exposure to corticosteroids is known to increase the pulmonary compliance of preterm animals. We wished to determine whether this was due solely to alteration in lung surfactant content. Rabbit does were injected with either vehicle alone or betamethasone on days 25 and 26 of gestation. Fetuses were delivered at 27 days and given either 50% lactated Ringer's or intratracheal natural surfactant prior to their first breath. Fetuses were mechanically ventilated at a tidal volume of 12 ml/kg for 60 min with periodic compliance measurements. Following ventilation an alveolar lavage was collected for phosphatidylcholine determination. Some fetuses did not undergo ventilation but had saline compliance studies instead. Fetuses given intratracheal surfactant had a higher dynamic compliance than fetuses exposed to antenatal corticosteroids (0.55 +/- 0.01 versus 0.48 +/- 0.02 ml/cm H2O/kg, respectively). Fetuses exposed to antenatal corticosteroids and given intratracheal surfactant had a dynamic compliance (0.66 +/- 0.02) that was greater than those exposed to either single therapy. This was found despite an alveolar surfactant content equal to that in fetuses receiving intratracheal surfactant alone. Saline compliance at birth was significantly greater for fetuses exposed antenatally to steroids. These data imply the existence of a nonsurfactant mechanism by which antenatal corticosteroids increase fetal pulmonary compliance.

Animals↗
PubMed1987

Severe fetomaternal hemorrhage. A report of four cases.

Four cases of severe fetomaternal hemorrhage (FMH) presented with severe anemia and signs of circulatory failure. One of the patients developed the syndrome of persistent fetal circulation. The diagnosis of FMH was confirmed in all using Kleihauer-Betke tests, which demonstrated abundant fetal erythrocytes in the maternal circulation. Three infants survived after prompt volume replacement and correction of anemia. The only fatality was related to an underlying chromosomal disorder. The majority of reported neonatal deaths due to FMH have occurred when shock was the presenting manifestation.

Adult↗
PubMed1985

Influence of theophylline on fetal rat lung phosphatidylcholine synthesis in vivo.

In an attempt to resolve conflicting reports on the effectiveness of theophylline in stimulating fetal lung surfactant production in vivo, we examined the influence of theophylline on fetal rat lung phosphatidylcholine synthesis. Intraperitoneal administration of theophylline to the pregnant rat produced elevated serum levels in both mother and fetus. The fetal:maternal ratio was 0.85:0.90. Doses of theophylline ranging between 5 and 180 mg/kg/day resulted in no increase in the rate of incorporation of choline into phosphatidylcholine or its disaturated species. There was also no increase in the lung tissue concentration of these phospholipids. Theophylline does not appear to stimulate fetal rat lung phosphatidylcholine synthesis at nontoxic serum levels.

Animals↗
PubMed1984

Fetal-neonatal uremia in advanced maternal diabetes.

A symmetrically growth retarded premature infant was born to a mother with advanced diabetic nephropathy, chronic renal failure, and hypertension, and managed with aggressive medical therapy without the use of dialysis. The neonatal course was uncomplicated, except for cord blood creatinine and BUN concentrations of 4.7 mg/dl and 116 mg/dl, respectively, that fell to 1.1 mg/dl and 44 mg/dl by 2 days of age. Strict glucose control, careful management of the metabolic abnormalities of uremia, and periodic surveillance of fetal well-being led to a successful pregnancy.

Cesarean Section↗
PubMed1984

Amniotic fluid arborization: effect of blood, meconium, and pH alterations.

The effects of blood and meconium at various dilutions and pH alterations on the fern test were evaluated in an in vitro study. Thirty-six specimens of amniotic fluid across gestational ages (16 to 42 weeks) were tested. The fern test was unaffected by meconium at any concentration and by blood at dilutions of 1:10 or greater. When blood and amniotic fluid were mixed in equal amounts, ferning was not present. Arborization of amniotic fluid was unaffected by pH alterations. These findings support the clinical usefulness of the fern test for the determination of ruptured membranes, even in the presence of blood or meconium contamination, and of pH alterations.

Amniotic Fluid↗