P. L. Ballard

Washington University in St. Louis

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Roberta A. Ballard

University of California, San Francisco

Scott A. Lorch

Children's Hospital of Philadelphia

Jeffrey D. Merrill

University of California, San Francisco

Christiana R. Farkouh

Children's Hospital of Philadelphia

Harry Ischiropoulos

Children's Hospital of Philadelphia

Benedict J. Canny

University of Adelaide

Juergen F. Schaefer

University of Tübingen

Mutlu Hayran

Hacettepe University

Licia Lugli

University of Modena and Reggio Emilia

Peter Bartmann

University Hospital Bonn

Cooperative Institutions

University of California, San Francisco

Children's Hospital of Philadelphia

University of Pennsylvania

University Children's Hospital Tübingen

Washington University in St. Louis

Women & Children's Hospital of Buffalo

Philadelphia University

Schneider Children's Hospital

Monash University

Harvard University

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Tracheal fluid in fetal lambs: spontaneous decrease prior to birth

Journal of Applied Physiology (1979)

Joseph A. Kitterman P. L. Ballard Judith A. Clements E. Joseph Mescher William H. Tooley

We studied tracheal fluid (TF) production in 14 fetal lambs: 6 controls, 6 receiving atropine on 1 or more of the last 7 days before birth, and 2 with bilateral section of the cervical vagosympathetic trunk. A cannula diverted all TF into an intrauterine bag; we collected TF intermittently and measured its volume. All ewes delivered spontaneously at 128-150 days' gestation. TF production decreased before birth in all fetuses except one control. TF production decreased before birth in all fetuses except one control. TF production did not correlate with fetal arterial blood gas tensions, hematocrit, or plasma proteins. In controls only, TF production correlated with fetal arterial pH (P less than 0.02); however, the pH range was small and the correlation has questionable physiological significance. For all fetuses, TF production during the 7 days before birth correlated inversely with the plasma cortisol concentration of 48 h previously (n = 36; r = -0.603; P less than 0.001). We conclude a) TF production in fetal lambs decreases before spontaneous term or preterm labor; b) this decrease is not affected by atropine or by section of the cervical vagosympathetic trunk; and c) the decrease in TF production may be related to increased secretion of cortisol.

10.1152/jappl.1979.47.5.985

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Citations (139)

Inhibitors of prostaglandin synthesis, tracheal fluid, and surfactant in fetal lambs

Journal of Applied Physiology (1981)

Joseph A. Kitterman G. C. Liggins Judith A. Clements Guilherme Campos C. H. Lee

To study their effects on tracheal fluid (TF) production and surfactant flux, we gave 12-h infusions of prostaglandin synthetase inhibitors (PGSI) on 16 occasions to 10 fetal lambs at gestational ages (GA) of 125--141 days. Results were similar with both sodium meclofenamate (13.9 +/- 3.4 mg.kg-1, 12 studies) and indomethacin (33.6 +/- 8.0 mg.kg-1, 4 studies). All studies were done at least 6 days after surgery and 4 days before spontaneous birth. During infusions of PGSI, there were no changes in fetal arterial blood pressure, pH, PaO2, PaCO2, TF production or its concentration of sodium, potassium, and chloride; calcium concentration in TF increased slightly. We expressed tracheal surfactant flux as micrograms.kg-1.h-1 of saturated phosphatidylcholine (SPC). If control SPC flux was less than 5 micrograms.kg-1.h-1 (10 studies at GA of 125--141 days), it did not change during infusion of PGSI; however, if control was greater than 5 micrograms.kg-1.h-1 (6 studies at GA 132--140 days), SPC flux decreased during the infusions in all studies. The results suggest that prostaglandins do not strongly influence TF production up to 4 days before birth and that prostaglandins are involved in the increased flux of surfactant which occurs in late gestation.

10.1152/jappl.1981.51.6.1562

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Citations (27)

ORIGINALES - Asociación entre el cortisol plasmático y la enfermedad pulmonar crónica en los recién nacidos pretérmino.

PEDIATRICS (2001)

Yue Ning Jeffrey D. Merrill Roberta A. Ballard P. L. Ballard Beverly A. Banks

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Acknowledgement to the Reviewers

Neonatology (2006)

Alberto Berardi Licia Lugli Fabrizio Ferrari Giancarlo Gargano Maria D’Apolito

Acknowledgement

10.1159/000097250

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Author Index Vol. 90, 2006

Neonatology (2006)

Alberto Berardi Licia Lugli Fabrizio M. Ferrari Giancarlo Gargano Maria D’Apolito

10.1159/000097251

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Contents Vol. 90, 2006

Neonatology (2006)

Alberto Berardi Licia Lugli Fabrizio Ferrari Giancarlo Gargano Maria D’Apolito

10.1159/000097253

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Citations (1)

165. Radioreceptor assay of natural and synthetic glucocorticoids in man

Journal of Steroid Biochemistry (1974)

John D. Baxter P. L. Ballard

10.1016/0022-4731(74)90310-0

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Stimulation of fetal rabbit lung development with maternal administration of 3 5 di methyl 3' isopropyl l thyronine

Clinical research (1980)

P. L. Ballard B J Benson Arlette Bréhier J. P. Carter Eugéne C. Jorgensen

Thyronine

Isopropyl

Rabbit (cipher)

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Effects of antenatal glucocorticoid administration on ductus arteriosus of preterm lambs

AJP Heart and Circulatory Physiology (1981)

Ronald I. Clyman Françoise Mauray C. Roman M. A. Heymann P. L. Ballard

We have previously shown that the incidence of patent ductus arteriosus (PDA) in premature infants whose mothers received prenatal glucocorticoid therapy was significantly lower than that of an untreated group. In addition, the incidence of respiratory distress syndrome was lower in the treated than in the untreated group. To determine whether glucocorticoids affect the ductus arteriosus itself, we studied the effects of a 48-h intravenous infusion of 1 mg/h hydrocortisone in prematurely born lambs (120-129 days, 0.84 gestation). Estimations of ductus patency were made on 1-h-old lambs by radioactive microsphere injections. We found that hydrocortisone infusions facilitate the closure of the ductus without altering the severity of respiratory distress in premature lambs. In the lamb, prostaglandin E2 (PGE2) inhibits the ability of the ductus to contract in response to O2. Because production of PGE2 has been shown to be inhibited by hydrocortisone in several isolated organ systems, we measured PGE2 plasma concentrations in treated and untreated animals. We found circulating PGE2 concentrations to be similar in the two groups; furthermore, release of PGE2 by isolated ductal rings in vitro was similar in treated and untreated animals. This contradicts the hypothesis that diminished PGE2 concentrations, either circulating or in the tissue, are the cause for ductus arteriosus closure in hydrocortisone-treated animals. However, hydrocortisone treatment decreases the sensitivity of the ductus arteriosus in vitro to the relaxing action of PGE2. These findings suggest that glucocorticoid treatment decreases the incidence of PDA in premature infants by affecting the interaction of PGE2 with ductal tissue.

Ductus arteriosus

10.1152/ajpheart.1981.241.3.h415

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Citations (59)

Urinary Metabolites of Oxidative Stress and Nitric Oxide in Preterm and Term Infants

Neonatology (2006)

Christiana R. Farkouh Jeffrey D. Merrill P. L. Ballard Roberta A. Ballard Harry Ischiropoulos

Many neonatal diseases have been associated with oxidative stress and altered nitric oxide status.To determine the effects of clinical interventions on the levels of urinary peroxides, a marker of oxidative stress, and urinary nitrate/nitrites, indices of nitric oxide production and metabolism, in the first 72 h of life in premature infants.A single, spot urine sample was collected from 82 premature and 20 healthy term infants within the first 72 h of life. The peroxide levels were quantified using a fluorometric method, and nitrate/nitrite levels were quantified by chemiluminescence.Premature infants had a median peroxide level of 10.0 micromol/mmol creatinine (Cr) (interquartile range 4.8-20.0 micromol/mmol Cr). These values were significantly higher than term infants (median 5.0 micromol/mmol Cr, interquartile range 2.7-10.0 micromol/mmol Cr). Urinary nitrate/nitrite levels were not significantly different between preterm (220.5 micromol/mmol Cr, interquartile range 161-287 micromol/mmol Cr) and healthy term infants (244 micromol/mmol Cr, interquartile range 194-316 micromol/mmol Cr). For urinary peroxides, infants on TPN had significantly higher urinary peroxide levels than infants who were not on TPN at the time of urine collection (p = 0.006). Administration of indomethacin was associated with lower levels of urinary nitrate/nitrites (p = 0.0003). Both effects remained significant after controlling for gestational age, degree of respiratory distress and day of urine collection.Monitoring the level of both peroxides and nitrate/nitrite may offer added information about the degree of oxidative stress experienced by a newborn but needs to account for clinical and therapeutic interventions.

Interquartile range

10.1159/000093633

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Citations (19)