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Biomedical subjects

M Hallman

Publications and source records attributed to M Hallman.

At least 91 records · Page 5Linked to original sources
PubMed1993

The effect of antenatal dexamethasone administration on the fetal and neonatal ductus arteriosus. A randomized double-blind study.

OBJECTIVE: To determine whether antenatal dexamethasone sodium phosphate administration constricts the fetal ductus arteriosus or improves spontaneous closure of the ductus in premature infants. DESIGN: A randomized double-blind study. SETTING: University hospital of Helsinki, Finland. PARTICIPANTS: Sixty-one pregnant women with threatened preterm delivery between 24 and 31.9 weeks' gestation and 57 of their offspring (28 in the dexamethasone and 29 in the placebo group), born at 24 to 34.9 weeks' gestation, were studied using Doppler echocardiography. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Between the dexamethasone and placebo groups, there were no significant differences in systolic or diastolic flow velocity values in the fetal ductus arteriosus. Of the 29 infants with respiratory distress syndrome, 26 (90%) had hemodynamically significant patent ductus arteriosus and received indomethacin sodium: 12 (92%) of 13 dexamethasone-treated infants and 14 (88%) of 16 placebo-treated infants. One placebo-treated infant was ligated. Of the 28 infants without respiratory distress syndrome, only four (14%) had hemodynamically significant patent ductus arteriosus. In infants born at or before 30 weeks' gestation, spontaneous closure of the ductus occurred more frequently after administration of prenatal dexamethasone (in six of 17 infants; 35%) than placebo (in none of 10 infants; P < .05). CONCLUSIONS: Our data indicate that antenatal dexamethasone administration had no constrictive effect on the ductus arteriosus of the fetus between 24 and 31 weeks' gestation. However, antenatal dexamethasone had a beneficial effect on ductal closure in very premature infants.

Adult↗
PubMed1993

Transforming growth factor-beta 2 prevents preterm delivery induced by interleukin-1 alpha and tumor necrosis factor-alpha in the rabbit.

OBJECTIVES: The purpose of the study was to determine whether preterm parturition in the rabbit can be induced by intraamniotic injection of proinflammatory cytokines, interleukin-1 alpha and tumor necrosis factor-alpha, and whether transforming growth factor-beta 2, an inhibitor of the cytokine-induced prostaglandin synthesis, modifies the effect of these cytokines. STUDY DESIGN: New Zealand White rabbits were injected in each amniotic cavity on day 24 of gestation with one of the following: a combination of interleukin-1 alpha (150 ng) and tumor necrosis factor-alpha (1.25 micrograms), 50 ng of transforming growth factor-beta 2 concomitantly with interleukin-1 alpha and tumor necrosis factor-alpha, or vehicle. In the first study the animals were observed for signs of delivery until day 29 of gestation. In the second study the effect of transforming growth factor-beta 2 (50 ng/fetus) on the rate of premature delivery was evaluated. In the third study the concentrations of prostaglandin E2 and 13,14-dihydro-15-keto-prostaglandin F2 alpha were measured in the amniotic fluid on day 27 of gestation. The statistics used were Fisher's exact test, the chi 2 test, and the Mann-Whitney U test. RESULTS: Altogether 61 of 191 fetuses (32%) were born prematurely in the interleukin-1 alpha-tumor necrosis factor-alpha group, whereas only two of 161 fetuses (1.2%) (p = 0.0001) and one of 159 (0.6%) (p = 0.0001) were born prematurely in the interleukin-1 alpha-tumor necrosis factor-alpha-transforming growth factor-beta 2 group and in the control group, respectively. Of the 23 animals injected with interleukin-1 alpha and tumor necrosis factor-alpha, six (26%) delivered all of their fetuses prematurely versus none in the other groups (p = 0.02). None of the 88 fetuses in the transforming growth factor-beta 2 group were born prematurely. The prostaglandin E2 concentrations in the amniotic fluids were higher in the interleukin-1 alpha-tumor necrosis factor-alpha group than in the interleukin-1 alpha-tumor necrosis factor-alpha-transforming growth factor-beta 2 group (p = 0.05) or in the control group (p = 0.02). CONCLUSIONS: Preterm parturition can be provoked in the rabbit by intraamniotic injections of interleukin-1 alpha and tumor necrosis factor-alpha. Transforming growth factor-beta 2 prevents the cytokine-induced increase in premature delivery.

Amniotic Fluid↗
PubMed1993

Outcome at twelve months of adjusted age in very low birth weight infants with lung immaturity: a randomized, placebo-controlled trial of human surfactant.

We compared the neurodevelopmental outcome of extremely premature, surfactant-deficient infants who received either prophylactic surfactant at birth, "rescue" surfactant after the clinical diagnosis of respiratory distress syndrome was established, or placebo. Infants studied were participants in a randomized, bicenter (San Diego, Calif., and Helsinki, Finland), controlled trial of human surfactant therapy. One hundred fifty infants (prophylaxis group, 63 infants; rescue group, 57; placebo group, 30) were prospectively enrolled at 38 weeks of gestational age. There were no neonatal intergroup differences in the incidence or severity of sonographic central nervous system abnormality or retinopathy. One hundred forty-five infants were alive at 1 year of adjusted age, at which time growth, neurosensory, and neurologic outcome were similar in all three treatment groups at both centers. Cerebral palsy occurred in 20% overall. Five infants (3.5%) were functionally blind. However, infants treated at birth had lower mean mental and motor scores on the Bayley Scales of Infant Development compared with those of infants rescued with surfactant after the onset of respiratory distress syndrome (Mental Development Index: 78 vs 96, p = 0.02; Psychomotor Development Index: 73 vs 87, p = 0.04). Chronic lung disease occurred more frequently in the prophylactically treated group and contributed to the subjects' neurologic and developmental morbidity. Because prophylactic surfactant treatment offered no neurodevelopmental advantage and may contribute to poorer outcome, we currently recommend early surfactant replacement only for those infants who have postnatal evidence of respiratory distress syndrome.

Brain↗
PubMed1993

Corticotropin-releasing hormone and cortisol in cord plasma in relation to gestational age, labor, and fetal distress.

Concentration of corticotropin-releasing hormone (CRH) has earlier been found to increase greatly in maternal plasma during the last trimester of normal pregnancy and even more in preeclampsia. This CRH is thought to be of placental origin, and it may stimulate maternal or fetal pituitary adrenal axis. We studied CRH in umbilical cord venous plasma in relation to gestation, labor, and fetal distress. There was a great maternal-to-fetal concentration difference in plasma CRH levels, a hundredfold at term pregnancy, suggesting that the placenta releases CRH mainly into the maternal rather than into the fetal circulation. Length of gestation or the mode of delivery did not affect CRH levels in cord plasma. Cord CRH levels were higher (median, 24.1, range, 14.2 to 67 pmol/liter) in six preterm infants with chronic fetal distress, born to mothers with severe preeclampsia and in nine infants born after premature rupture of membranes (median, 17.0, range, 7.65 to 53 pmol/liter), than in 12 preterm control infants born after uncomplicated pregnancy (median, 6.3 range, 1.0 to 27.5 pmol/liter). No significant correlation was found between CRH and cortisol levels in cord plasma. Increased cortisol levels in cord plasma were associated with spontaneous vaginal delivery but not with chronic fetal distress. These findings demonstrated that placental release of CRH into the fetal circulation may be increased in pregnancy complications with chronic fetal distress but failed to prove any relationship between placental CRH and fetal adrenal function.

Corticotropin-Releasing Hormone↗
PubMed1993

Value of absent or retrograde end-diastolic flow in fetal aorta and umbilical artery as a predictor of perinatal outcome in pregnancy-induced hypertension.

There is insufficient data on the value of absent or retrograde end-diastolic flow (AREDF) in the fetal umbilical artery, descending aorta and aortic arch to predict perinatal outcome. In this prospective investigation, 65 pregnant women between 24 and 34 weeks' gestation with pregnancy-induced hypertension were studied by color Doppler echocardiography. Pregnancies leading to birth at or before 34.0 gestational weeks (23 with and 19 without AREDF) were included in the outcome analysis. Fetuses with AREDF were delivered at earlier gestational ages (p = 0.006). They had a higher incidence of gastrointestinal complications (p = 0.01), bronchopulmonary dysplasia (p = 0.03), intraventricular hemorrhage (p = 0.03) and vascular hypotension (p = 0.03) than those without AREDF. The presence of AREDF was associated with a mortality rate of 30%, whereas in fetuses without AREDF there was no mortality (p = 0.01). Using logistic regression and taking into consideration various perinatal factors, the presence of AREDF (p = 0.03) and early gestational age (p = 0.0001) were associated with serious neonatal diseases or death. A reverse diastolic flow in the aortic isthmus was registered in five fetuses; three died during the perinatal period and one was severely damaged. According to our results, AREDF, particularly with the appearance of reverse diastolic flow in the isthmus of the aortic arch, is a predictor of poor neonatal outcome.

Adult↗
PubMed1993

Association between neonatal care practices and efficacy of exogenous human surfactant: results of a bicenter randomized trial.

The purpose of this study was to analyze the impact of neonatal care practices on the efficacy of exogenous human surfactant. Two hundred newborns (gestational age 24.0 to 29.9 weeks, lecithin-sphingomyelin ratio less than 2 or absent phosphatidylglycerol, and requirement of mechanical ventilation at birth) participated in a randomized bicenter trial of human surfactant substitution. In only one of the two sites (site 2) surfactant substitution decreased the severity of respiratory failure and increased neonatal survival without bronchopulmonary dysplasia. For analysis of three-way association, continuous variables describing patient characteristics and treatment were dichotomized at the median. The following variables were significantly associated with good outcome in site 1 and 2 and with surfactant substitution in site 2: low oxygen requirement during first three neonatal days, low mean airway pressure during second and third day, low PaCO2 during first two neonatal days, and no ligation of ductus arteriosus. Low fluid intake during the first three days and low colloid intake during the first two days of life were associated with good outcome in both sites. The ratio between mean airway pressure and the oxygen requirement was higher in site 2 than in site 1 during the first day of life. Fluid intake and ventilatory management may influence the efficacy of exogenous surfactant.

Humans↗
PubMed1992

Inositol supplementation in premature infants with respiratory distress syndrome.

BACKGROUND: Inositol influences cellular function and organ maturation. Feeding premature infants inositol-rich breast milk increases their serum inositol concentrations. Whether inositol supplementation benefits infants receiving fluids for parenteral nutrition, which are inositol-free, is not known. METHODS: We carried out a placebo-controlled, randomized, double-blind trial to determine the effects of administering inositol (80 mg per kilogram of body weight per day) during the first five days of life to 221 infants with respiratory distress syndrome who were receiving parenteral nutrition (gestational age, 24 to 32 weeks; birth weight, less than 2000 g). All the infants were treated with mechanical ventilation and some with surfactant as well. The primary end point was survival at 28 days without bronchopulmonary dysplasia. RESULTS: The 114 patients given inositol had significantly lower mean requirements for inspiratory oxygen (P less than 0.01) and mean airway pressure (P less than 0.05) from the 12th through the 144th hour of life than did the 107 infants given placebo. Eighty-one infants given inositol and 51 given placebo survived without bronchopulmonary dysplasia (71 vs. 55 percent; P = 0.005). In the 65 infants given surfactant, however, inositol had no effect on the degree of respiratory failure. Thirteen infants given inositol and 21 given placebo had retinopathy of prematurity (13 vs. 26 percent; P = 0.022); none of the infants given inositol had stage 4 disease, whereas 7 of those given placebo did (0 vs. 9 percent; P = 0.012). Among the infants given placebo, those who had poor outcomes (death, bronchopulmonary dysplasia, or stage 4 retinopathy of prematurity) had lower serum inositol concentrations during days 2 through 7 than those who had good outcomes (P less than 0.01). CONCLUSIONS: The administration of inositol to premature infants with respiratory distress syndrome who are receiving parenteral nutrition during the first week of life is associated with increased survival without bronchopulmonary dysplasia and with a decreased incidence of retinopathy of prematurity.

Bronchopulmonary Dysplasia↗
PubMed1992

Free radical activity during development of insulin-dependent diabetes mellitus in the rat.

Free radical-induced lipid peroxidation was quantified by measuring expired pentane from diabetic prone BB Wistar rats of 45-90 d of age. Insulin-dependent diabetes mellitus was manifest at the age of 71 +/- 8 d. Expired pentane increased from 2.1 +/- 0.7 to 5.0 +/- 3.0 pmol/100g/min (p less than 0.01) at manifestation of the disease and remained high throughout the test period. In healthy age-matched control rats it persisted low. In rats made diabetic with streptozotocin, expired pentane remained low. The changes in expired pentane suggest that the development of endogenous insulin-dependent diabetes mellitus in BB rats is associated with increased free radical activity. This is not due to hyperglycemia or ketosis per se, and reflects a fundamental difference in the free radical activity between the spontaneously diabetic BB rats and the disease produced by streptozotocin. Development of spontaneous insulin-dependent diabetes in BB rats is associated with increased free radical activity that persists after the manifestation of the disease.

Animals↗
PubMed1992

Transforming growth factor-beta opposes the stimulatory effects of interleukin-1 and tumor necrosis factor on amnion cell prostaglandin E2 production: implication for preterm labor.

OBJECTIVE: In preterm labor increased concentrations of interleukin-1 and tumor necrosis factor are present in amniotic fluid. These cytokines may promote labor by stimulating the production of prostaglandins by intrauterine tissues. In many biologic processes, transforming growth factor-beta modifies the actions of cytokines. We studied the effect of transforming growth factor-beta on the cytokine-induced prostaglandin E2 production by amnion cells. STUDY DESIGN: Human amnion cells in monolayer culture were treated with interleukin-1, tumor necrosis factor, or vehicle in the presence or absence of transforming growth factor-beta. The prostaglandin E2 production was measured. RESULTS: Transforming growth factor-beta decreased the interleukin-1- or tumor necrosis factor-induced prostaglandin E2 production by 70% to 80% and the basal prostaglandin E2 synthesis by 27%. The synergistic stimulation of prostaglandin E2 production by the combination of interleukin-1 with tumor necrosis factor was inhibited by 80% in cells treated with transforming growth factor-beta. Transforming growth factor-beta 1, -beta 2, and -beta 1,2 were equipotent. CONCLUSION: Transforming growth factor-beta suppresses the cytokine-induced prostaglandin E2 production by amnion cells and may be an important factor in maintaining pregnancy in the face of labor-promoting cytokines.

Amnion↗
PubMed1992

Premature rupture of the membranes: effect of penicillin prophylaxis and long-term outcome of the children.

To assess the value of prophylaxis with penicillin in women with premature rupture of membranes (PROM) and the long-term outcome of children born after prolonged PROM, we studied 221 women with this condition. Penicillin (5 mu twice, 6 hours apart) was given intravenously to 50 women and placebo to 51 women, whereas 76 comparable patients were treated without penicillin or placebo. The time interval between PROM and delivery ranged from 14 hours to 56 days. Chorioamnionitis occurred more frequently (p less than 0.05) among patients with placebo (14%) than among those treated with penicillin (2%). One puerperal endometritis appeared in the placebo group compared with none in the penicillin group. One newborn (1.7%) born to a mother with placebo prophylaxis developed septicemia, compared with none in the penicillin group. The outcomes of pregnancies complicated with PROM treated without penicillin or placebo were comparable with those in the placebo group. In addition, we compared somatic and psychomotor development of 159 children born to mothers with prolonged PROM (more than 12 hours; mean, 5.6 days; range, 14 to 1344 hours) with those of 43 children born at similar gestational age within 5 hours after PROM. No pulmonary sequelae could be linked to the long time period between PROM and delivery, but infants born soon after PROM more often (p less than 0.05) had cerebral palsy (8 of 43, 18.6%) than did infants born after prolonged PROM (7 of 159; 4.4%). We conclude that, in cases with PROM, penicillin prophylaxis decreases maternal and neonatal infectious morbidity and that the long interval between PROM and delivery does not impair the long-term outcome for these children.

Adult↗
PubMed1991

The effects of indomethacin and a beta-sympathomimetic agent on the fetal ductus arteriosus during treatment of premature labor: a randomized double-blind study.

To study the effect of maternal indomethacin or nylidrine hydrochloride treatment on the fetus ductus arteriosus and the pulmonary artery, 27 women with threatened preterm labor between 24 and 34 weeks' gestation were studied by echocardiography. Fourteen women were treated with indomethacin and 13 with nylidrin. Both systolic and diastolic velocities in the ductus increased after administration of indomethacin indicating constriction in nine fetuses, and exceeded the corresponding velocities in the fetuses of the nylidrin group (p = 0.001). However, there were no changes in pulmonary artery flow velocities (p greater than 0.5). In the indomethacin group, there was a significant linear positive relationship between the gestational age and the change in ductal flow velocity. Three of the nine patients with ductal constriction also had tricuspid regurgitation. These findings indicate that indomethacin, not nylidrin, causes transient constriction of the ductus arteriosus and the constrictive response increases with the gestational age. We recommend echocardiographic surveillance of fetal hemodynamics when prostaglandin synthesis inhibitors are used in the treatment of spontaneous preterm labor.

Blood Flow Velocity↗
PubMed1991

Synergistic stimulation of amnion cell prostaglandin E2 synthesis by interleukin-1, tumor necrosis factor and products from activated human granulocytes.

We examined the interactions between supernatant from FMLP-activated human granulocytes, recombinant interleukin-1 (IL-1) and recombinant tumor necrosis factor (TNF) in the stimulation of prostaglandin E2 (PGE2) production by human amnion cells. Amnion cells from elective term cesarian sections were cultured in monolayer culture. Human granulocytes were activated with FMLP and centrifuged to obtained cell-free supernatant. Amnion cells were treated with granulocyte supernatant, IL-1 alpha, IL-1 beta, TNF-alpha, TNF-beta, or different combinations of these. Each of the stimulators alone enhanced the PGE2 production 5- to 27-fold. Granulocyte supernatant was synergistic with each of the cytokines. The combinations of IL-1 alpha or IL-1 beta with either TNF-alpha or TNF-beta caused a synergistic stimulation of amnion cell PGE2 production as well, whereas the combinations of IL-1 alpha with IL-1 beta or of TNF-alpha with TNF-beta were not synergistic. Furthermore, granulocyte supernatant was synergistic with the combination of IL-1 and TNF, resulting in a more than 150-fold stimulation of PGE2 production. Indomethacin completely suppressed these effects. We propose that granulocyte products acting together with IL-1 and TNF enhance PGE2 synthesis during inflammation, and serve as signals for the initiation of preterm labor in the setting of intra-amniotic infection.

Amnion↗
PubMed1991

A product of activated human granulocytes stimulates prostaglandin E2 synthesis in human amnion cells.

Cell-free supernatant from formylmethionyl-leucyl-phenylalanine (fMLP)-activated granulocytes causes a time- and concentration-dependent stimulation of prostaglandin E2 (PGE2) production in amnion cells. PGE2 concentration in the culture medium after 36 h treatment with granulocyte supernatant (from 40 x 10(6) granulocytes/ml of amnion cell medium), 1.49 +/- 0.71 pg/ng DNA (n = 13), was significantly higher (p = 0.0015) than in control cells (0.33 +/- 0.23 pg/ng DNA, n = 13). Indomethacin abolished this stimulation. Granulocyte supernatant and human epidermal growth factor (hEGF) had an additive effect on amnion cell PGE2 production. Catalase, superoxide dismutase (SOD), protease inhibitors or the platelet-activating factor (PAF) antagonist L-659,989 had no effect. Actinomycin D, cycloheximide and mepacrine reduced the PGE2 production. The phospholipase A2 activity present in granulocyte supernatants was resistant to heating, whereas heating decreased their PGE2-stimulating activity by 92%. Exogenous phospholipase A2 had no effect on PGE2 synthesis. The granulocyte product could be precipitated with ammonium sulphate. On gel filtration of supernatant, two peaks of PGE2-synthesis stimulating activity were obtained (molecular weights 12,000 and 60,000). This data serve to explain the association of chorioamnionitis with preterm labor: activated granulocytes release a protein(s) that induces prostaglandin production in amnion cells, and thus promote labor.

Amnion↗
PubMed1991

Randomized, placebo-controlled trial of human surfactant given at birth versus rescue administration in very low birth weight infants with lung immaturity.

A randomized, placebo-controlled trial of human surfactant given intratracheally at birth (prophylactic) versus rescue administration after the onset of severe respiratory distress syndrome (RDS) was conducted among preterm infants born at 24 to 29 weeks of gestation. Singleton fetuses were randomly assigned to receive (1) placebo (air), (2) prophylactic surfactant treatment, or (3) rescue surfactant treatment; infants of multiple births received either (1) prophylactic or (2) rescue treatment. Of 282 potentially eligible fetuses, 246 infants received treatments at birth and 200 infants had RDS. Outcomes are presented both as an intention-to-treat analysis (including infants who met exclusion criteria at or after birth) and as a full treatment protocol analysis for those infants with RDS and likely to benefit from surfactant. Preterm infants (mean 1.0 kg birth weight, 27 to 28 weeks of gestational age) randomly assigned to receive prophylactic treatment received surfactant soon after birth; those assigned to receive rescue surfactant had instillation at a mean age of 220 minutes if the lecithin-sphingomyelin ratio was less than or equal to 2.0 and no phosphatidylglycerol was detected in either amniotic fluid or initial airway aspirate, oxygen requirements were a fraction of inspired oxygen of greater than 0.5, and mean airway pressure was greater than or equal to 7 cm H2O from 2 to 12 hours after birth. Up to four treatment doses (or air) were permitted within 48 hours; approximately 60% of surfactant-treated infants required two or more doses. Surfactant-treated infants had significantly less pulmonary interstitial emphysema than placebo-treated infants (p = 0.02), but there were no other significant differences in mortality rates or morbidity. Indexes of oxygenation and ventilation were improved in surfactant recipients during the first 24 hours. An intention-to-treat analysis found no significant differences between infants given placebo and surfactant-treated infants or between prophylactic- and rescue-treated infants; an improved total mortality rate (p = 0.002) was found among surfactant-treated infants in Helsinki but not in San Diego. Among infants with RDS, the total mortality rate was significantly improved (p = 0.004) with surfactant treatment but not the proportion alive and without bronchopulmonary dysplasia at 28 days (p = 0.052), or the proportion alive and without bronchopulmonary dysplasia at 38 weeks of postconceptional age (p = 0.18) to adjust for differences in prematurity. Deaths caused by RDS or bronchopulmonary dysplasia were significantly reduced among surfactant recipients (p = 0.0001). Neither among singletons nor among multiple-birth infants was there a selective advantage to prophylactic versus rescue treatment.(ABSTRACT TRUNCATED AT 400 WORDS)

Bronchopulmonary Dysplasia↗
PubMed1991

Immunogenicity of surfactant. I. Human alveolar surfactant.

The immunogenicity of lung surfactant derived from amniotic fluid has been well established. We have set out to examine the antigenic similarity of human surfactant to non-human alveolar surfactants currently being used therapeutically in clinical trials with neonatal respiratory distress syndrome. To this end, we raised a series of eight monoclonal antibodies in rats directed to human surfactant (H1 to H8). All antibodies bound human surfactant as measured by ELISA. Four of these monoclonal antibodies bound surfactant components by Western blot analysis: all bound a 9-10-kD species. In addition, one antibody (H2) bound a protein of 16 kD, one (H8) a 6-kD protein, and one (H6) a 30-kD protein. When mixed with surfactant, three antibodies, H4, H7 and H8, profoundly altered surfactant activity in vitro in the pulsating bubble surfactometer. Three other antibodies, H1, H2, and H5 moderately inhibited surfactant's surface activity. We also examined the cross-reactivity of these monoclonal antibodies with bovine (CLSE) and porcine (Curosurf) surfactants. By Western blot analysis, only H6 bound these heterologous surfactants. Other antibodies did so by ELISA. However, functional assays indicated that antibodies H7, H8 and H4 all greatly inhibited CLSE surface activity in vitro. Five antibodies (H1-H4 and H8) inhibited Curosurf function. Thus, human surfactant species, especially low molecular weight species, are highly antigenic. Antibodies to alveolar surfactants may inhibit surfactant function in vitro. As indicated by Western blot and cross-inhibition data, human lower molecular weight surfactants share epitopes with proteins from therapeutically important porcine and bovine surfactants. The potential importance of these findings to treatment of neonatal respiratory distress syndrome with heterologous surfactants is discussed.

Amniotic Fluid↗