Biophysical and chemical stability of surfactant/budesonide and the pulmonary distribution following intra-tracheal administration.

Intra-tracheal instillation of budesonide using surfactant as a vehicle significantly decreased the incidence of bronchopulmonary dysplasia or death in preterm infants. The formularity of surfactant supplemented with budesonide and biophysical and chemical stability of the suspension has not been well reported. The aims are to investigate the biophysical and chemical stability of two surfactant preparations, Survanta and Curosurf, supplemented with budesonide. Biophysical property of the surface tension of Survanta and Survanta/budesonide suspension and of Curosurf and Curosurf/budesonide suspension was conducted by a pulsating bubble surfactometer and by a drop shape tensiometer. Chemical stability of Survanta/budesonide and of Curosurf/budesonide suspensions was tested by high-performance liquid chromatography analysis (HPLC). Pulmonary distribution of Survanta/18F-budesonide suspension was examined by a Nano/PET digital scan in rats. The Marangoni effect of Survanta, Curosurf, and budesonide was tested by digital high speed photography. For Survanta supplemented with budesonide, with a concentration ratio of ≥50, the surface tension-lowering activity was minimally affected. Similarly, the surface tension-lowering activity of Curosurf was not significantly affected by addition of budesonide, if the concentration ratio was ≥160. With these concentration ratios of both suspensions, HPLC analysis revealed no new compounds identified. Curosurf as compared to Survanta exhibited a significantly higher Marangoni effect. We conclude that with current dosage recommended for Survanta and Curosurf, both surfactant/budesonide suspensions are biophysically and chemically stable. Both surfactants can act as an effective vehicle for budesonide delivery.

Postnatal Steroids and Febrile Seizure Susceptibility in Preterm Children.

OBJECTIVE: To investigate risk factors, seizure characteristics, and outcomes of febrile seizure (FS) in children born very preterm. METHODS: This study used a prospective registry data set of 844 preterm infants (birth weight <1500 g and gestational age <32 weeks) admitted to NICUs from 2001 to 2009 in southern Taiwan. We investigated the prevalence, risks, seizure patterns, and outcomes of FS in children aged 5 years. RESULTS: Among 575 children (follow-up rate, 85.8%) followed up for 5 years, 35 (6.1%) developed FS. The FS and non-FS groups were comparable regarding their mean gestational age, birth weight, 5-minute Apgar score <6, and prenatal and postnatal complications. No difference was observed in the use of prenatal corticosteroids between the 2 groups. The FS group had a significantly higher rate of postnatal corticosteroid treatment than the non-FS group, even after adjusting for confounding factors (odds ratio, 5.4 [95% confidence interval, 1.9-15.8]; P = .006). No differences were observed in IQs or subsequent epilepsy rates between the 2 groups. Although no difference was observed in the age of FS onset or neurodevelopmental outcomes between the 2 groups, children with FS who received postnatal corticosteroid treatment had a significantly lower mean body temperature during the first FS attack compared with those who did not receive postnatal corticosteroid treatment (38.6 ± 0.4°C vs 39.2 ± 0.6°C; P = .034). CONCLUSIONS: Children born very preterm have a higher rate of FS, and postnatal corticosteroid treatment was associated with FS susceptibility in these children.

Effect of breast-feeding frequency on hyperbilirubinemia in breast-fed term neonate.

BACKGROUND: Hyperbilirubinemic neonates have significantly less bodyweight gain from nursery discharge to outpatient department (OPD) follow up. We tested the hypothesis that discharge instructions encouraging frequent breast-feeding given in the nursery would increase infant bodyweight gain and decrease the incidence of hyperbilirubinemia. METHODS: We enrolled consecutively live-born neonates who were discharged from the nursery and who received OPD follow up within the first 2 weeks of birth in 2011. The nursing staff discussed the discharge instructions with the parents at the time of nursery discharge. Parents were asked to fill in a nursing information form to record the frequency of breast-feeding and diaper change per day. RESULTS: Parents of 98 breast-fed term neonates provided complete nursing information forms. These 98 neonates were classified into two groups according to breast-feeding frequency, namely <8 times/day (63 neonates) and ≥8 times/day (35 neonates). A significant positive correlation between breast-feeding frequency and diaper change frequency per day indicated that the data were highly reliable. The gestational age, Apgar score, birthweight, and bodyweight at nursery discharge and at OPD were similar between the two groups. Neonates who were breast-fed ≥8 times/day had a significantly lower incidence of hyperbilirubinemia. CONCLUSIONS: Nursery discharge instructions that encouraged mothers to breast-feed their newborns frequently decreased the rate of hyperbilirubinemia in exclusively breast-fed term neonates.

Neonatal Hyperoxia Exposure Induces Kidney Fibrosis in Rats.

BACKGROUND: Human and animal studies have demonstrated that neonatal hyperoxia increases oxidative stress and adversely affects glomerular and tubular maturity. This study was undertaken to determine how exposure to neonatal hyperoxia affected kidney morphology and fibrosis and to elucidate the relationship between connective tissue growth factor (CTGF) and collagen expression in rat kidneys. METHODS: Sprague-Dawley rat pups were exposed to either hyperoxia or ambient air. The control groups were maintained in ambient air for 1 week and 3 weeks. The hyperoxia groups were exposed to >95% O2 for 1 week and subsequently placed in an environment of 60% O2 for an additional 2 weeks. The animals were euthanized on Postnatal Day 7 or 21 and the kidneys underwent histological analyses and oxidative stress and total collagen measurements. RESULTS: The rats reared in O2-enriched air exhibited significantly higher tubular injury scores (1.4 ± 0.5 vs. 0.7 ± 0.7 on Day 7; 1.4 ± 0.5 vs. 0.6 ± 0.5 on Day 21), a larger proportion of the cortex occupied by glomeruli (25.5 ± 4.1 vs. 21.3 ± 3.1% on Day 7; 20.1 ± 3.5 vs. 17.1 ± 1.7% on Day 21), larger glomerular sizes (84.7 ± 5.8 vs. 77.5 ± 6.1 µm on Day 7; 88.4 ± 2.9 vs. 84.9 ± 3.1 µm on Day 21), and higher total collagen content (54.1 ± 27.5 vs. 18.3 ± 6.3 µg/mg protein on Day 7; 397.4 ± 32.8 vs. 289.5 ± 80.0 µg/mg protein on Day 21) than did rats reared in ambient air. Immunohistochemical expressions of oxidative stress marker 8-hydroxy-2'-deoxyguanosine and CTGF immunoreactivities were significantly higher in the rats reared in O2-enriched air compared with the rats reared in ambient air on Postnatal Days 7 and 21. CONCLUSION: Neonatal hyperoxia exposure contributes to kidney fibrosis, which is probably caused by activated CTGF expression.

Effect of surfactant and budesonide on the pulmonary distribution of fluorescent dye in mice.

BACKGROUND: Surfactant is a useful vehicle for the intratracheal delivery of medicine to the distal lung. The aim of this study was to analyze the effect of intratracheal surfactant and budesonide instillation on the pulmonary distribution of fluorescent dye in mice. METHODS: Male athymic nude mice were assigned randomly as controls, fluorescent dye, fluorescent dye + surfactant (50 mg/kg), fluorescent dye + budesonide (0.25 mg/kg), and fluorescent dye + surfactant + budesonide groups. A total volume of 60 µL fluorescent solutions was intratracheally injected and followed by 60 µL of air. We photographed and measured fluorescence in the lungs, from the back, 15 minutes after intratracheal administration using an IVIS Xenogen imaging instrument. RESULTS: The fluorescent dye (1,1'-dioctadecyltetramethyl indotricarbocyanine iodide) was most strongly detected near the trachea and weakly detected in the lungs in mice administered with fluorescent solutions. Almost no fluorescence was seen in the lung region of control mice. Intratracheal administration of surfactant or budesonide increased fluorescent intensity compared with control mice. Combined administration of surfactant and budesonide further increased fluorescent intensity compared with mice given surfactant or budesonide alone. CONCLUSION: Surfactant and budesonide enhance the pulmonary distribution of fluorescent dye in mice.

Hypoxic/ischemic and infectious events have cumulative effects on the risk of cerebral palsy in very-low-birth-weight preterm infants.

BACKGROUND: Hypoxia/ischemia and inflammation are two major mechanisms for cerebral palsy (CP) in preterm infants. OBJECTIVE: To investigate whether hypoxia/ischemia- and infection-related events in the perinatal and neonatal periods had cumulative effects on CP risk in very-low-birth-weight (VLBW) premature infants. METHODS: From 1995 to 2005, 5,807 VLBW preterm infants admitted to Taiwan hospitals were enrolled. The cumulative effects of hypoxic/ischemic and infectious events during the perinatal and neonatal periods on CP risk at corrected age 24 months were analyzed. RESULTS: Of the 4,355 infants with 24-month follow-up, 457 (10.5%) had CP. The CP group had significantly higher incidences of hypoxia/ischemia-related events in the perinatal and neonatal periods, and sepsis in the neonatal period than the normal group. Three hypoxic/ischemic events, including birth cardiopulmonary resuscitation (OR 2.25; 95% CI 1.81-2.82), patent ductus arteriosus (PDA) ligation (2.94; 1.35-5.75) and chronic lung disease (3.14; 2.61-3.85) had the most significant contribution to CP. Relative to CP risk for infants with neither the three hypoxic/ischemic events nor sepsis, the CP odds increased 1.98-, 2.26- and 2.15-fold for infants with birth cardiopulmonary resuscitation, PDA ligation and chronic lung disease, respectively; while the combination with sepsis further increased the odds to 3.18-, 3.83- and 3.25-fold, respectively. Using the three hypoxic/ischemic events plus sepsis, CP rates were 10.0, 16.7, 26.7, 40.0 and 54.7% for infants with none, one, two, three and four events, respectively. CONCLUSIONS: Hypoxic/ischemic and infectious events across the perinatal and neonatal periods exerted cumulative effects on CP risk in VLBW premature infants.

Maternal nicotine exposure exacerbates neonatal hyperoxia-induced lung fibrosis in rats.

BACKGROUND: Maternal nicotine exposure increases lung collagen in fetal and newborn animals. Connective tissue growth factor (CTGF) plays a role in hyperoxia-induced pulmonary fibrosis. OBJECTIVE: To determine whether pre- and postnatal nicotine exposure can augment CTGF expression and postnatal hyperoxia-induced lung fibrosis. METHODS: Nicotine was administered to pregnant Sprague-Dawley rats at a dose of 6 mg/kg/day from gestational days 7-21 (prenatal nicotine-treated group) and gestational day 7 to postnatal day 14 (pre- and postnatal nicotine-treated group). A control group of pregnant dams was injected with an equal volume of saline. Within 12 h of birth, rats were exposed to room air or 1 week of >95% O2 and an additional 2 weeks of 60% O2 (3 weeks of hyperoxia). Lungs were taken for total collagen, CTGF expression and histological analyses. RESULTS: In each maternal treatment group, the rats reared in hyperoxia had a higher total collagen compared with rats reared in room air on postnatal days 7 and 21. Collagen content was significantly higher in rats born to pre- and postnatal nicotine-treated dams than rats born to saline-treated and prenatal nicotine-treated dams on postnatal days 7 and 21. Pre- and postnatal nicotine exposure and neonatal hyperoxia exposure increased CTGF expression on postnatal days 7 and 21. CONCLUSIONS: CTGF may be involved in the pathogenesis of lung fibrosis induced by maternal nicotine and neonatal hyperoxia, and maternal nicotine exposure exacerbates neonatal hyperoxia-induced lung fibrosis. These results are relevant to neonates who require supplemental oxygen and are exposed to the breast milk of smoking mothers during infancy.

Combined effects of maternal inflammation and neonatal hyperoxia on lung fibrosis and RAGE expression in newborn rats.

BACKGROUND: Receptors for advanced glycation end products (RAGE) have been implicated in fibrotic processes. We hypothesized that lung fibrosis induced by maternal lipopolysaccharide (LPS)-mediated inflammation and neonatal hyperoxia involves RAGE in newborn rats. METHODS: Pregnant Sprague-Dawley rats received intraperitoneal injections of LPS or normal saline (NS) on 20 and 21 d of gestation. The pups were reared in room air (RA) or an O2-enrich atmosphere (O2), creating the four study groups, NS + RA, NS + O2, LPS + RA, and LPS + O2. The O2 treatment was >95% O2 for 7 d, followed by 60% O2 for 14 d. RESULTS: Rat pups born to LPS-injected dams exhibited significantly higher lung interferon-γ and interleukin-1ß (IL-1ß) on postnatal day 7 than the pups born to NS-injected dams. Rat pups reared in hyperoxia expressed higher lung IL-10 on postnatal day 7, compared with the RA-reared pups. The LPS + O2 group had significantly higher total collagen and transforming growth factor-ß1 on postnatal days 7 and 21 than the NS+RA group. RAGE mRNA and sRAGE protein expression were significantly lower in the LPS + O2 group on postnatal day 7 than the NS+RA group. CONCLUSION: RAGE may be involved in the pathogenesis of lung fibrosis induced by maternal systemic inflammation and postnatal hyperoxia in rat neonates.

Oligohydramnios increases the risk of respiratory hospitalization in childhood: a population-based study.

BACKGROUND: Pulmonary hypoplasia is associated with reduced lung function in infancy. The aim of this study was to evaluate the hypothesis that children exposed to oligohydramnios display an increased risk of hospitalization for respiratory illness by using a population-based matched-cohort design. METHODS: We used three nationwide population-based data sets to identify 5,228 women who gave birth during 2004 to 2007 and were diagnosed with oligohydramnios during the third trimester of pregnancy. A cohort of 20,912 unaffected pregnant women was matched with these cases, according to neonatal sex and gestational age, maternal age and education, and level of prenatal care. Respiratory hospitalization and respiratory failure were defined using discharge diagnostic codes. RESULTS: Oligohydramnios-exposed children had an 8% higher incidence rate of respiratory hospitalization and an 80% higher incidence rate of respiratory failure, compared with children without oligohydramnios exposure. This risk remained after adjusting for all potential risk factors. Cox regression analyses indicated that the adjusted hazard ratios of respiratory hospitalization and respiratory failure were 1.07 (95% confidence interval (CI): 1.01-1.15; P = 0.030) and 2.20 (95% CI: 1.26-3.84; P = 0.005), respectively. CONCLUSION: Children exposed to oligohydramnios during the third trimester of pregnancy display an increased risk of hospitalization for respiratory illness.

Rho-kinase inhibitor Y-27632 attenuates pulmonary hypertension in hyperoxia-exposed newborn rats.

AIM: To test the hypothesis that neonatal hyperoxia induced pulmonary hypertension accompanied by increased Rho-kinase expression in rat lungs and that Rho-kinase inhibitor could attenuate right ventricular hypertrophy and pulmonary arterial remodeling. METHODS: Newborn rats were exposed to >95% O2 in the first week after birth, then to 60% O2 in the following 2 weeks. Control pups were exposed to room air over the same periods. The pups were injected with either Rho-kinase inhibitor Y-27632 (10 mg·kg(-1)·d(-1), ip) or vehicle from postnatal d 14 to 20. Lung and heart tissues were collected on postnatal d 7 and 21. Rho-kinase activity in lungs was measured using Western blotting and immunohistochemistry. The right ventricular hypertrophy and arterial medial wall thickness (MWT) were assessed morphologically. RESULTS: Rho-kinase activity in lungs was comparable between the hyperoxic and control pups on postnatal d 7, but it had a more than 2-fold increase in the hyperoxic pups on postnatal d 21. Moreover, the hyperoxic exposure induced structural features of pulmonary hypertension, as shown by the right ventricular hypertrophy and significantly increased arterial MWT. Administration with Y-27632 effectively blocked the hyperoxia-induced increase of Rho-kinase activity in lungs, and attenuated the right ventricular hypertrophy. CONCLUSION: Rho-kinase inhibitor may be a novel therapy for attenuating the hyperoxia-induced structural changes in pulmonary hypertension.

Effects of maternal retinoic acid administration on lung angiogenesis in oligohydramnios-exposed fetal rats.

BACKGROUND: All-trans retinoic acid (ATRA) induces in vitro angiogenesis and vascular endothelial growth factor (VEGF) secretion. Prenatal administration of vitamin A tends to increase the pulmonary and plasma levels of VEGF in the developing mouse. The aims of this study were to examine the effects of maternal retinoic acid treatment on lung VEGF expression and angiogenesis in oligohydramnios-exposed fetal rats. METHODS: On day 16 of gestation, pregnant Sprague-Dawley rats were randomly assigned to either the retinoic acid group (intragastric ATRA at 10 mg/kg body weight) or the vehicle group. We punctured each uterine sac to produce oligohydramnios, and fetuses in the opposite uterine horn served as controls. On day 21 of gestation, the fetuses were delivered by cesarean section. RESULTS: Rats exposed to oligohydramnios exhibited lower lung weights and lung/body weight ratios, and ATRA exhibited no effects on the body or lung weights of oligohydramnios-exposed rats. Lung microvessel density decreased in oligohydramnios-exposed rats of maternal vehicle-treated dams. Microvessel density was comparable between the oligohydramnios + retinoic acid group and the control + retinoic acid group. VEGF expression was comparable among control and oligohydramnios-exposed rats of maternal vehicle- or retinoic acid-treated dams. CONCLUSION: Maternal retinoic acid treatment did not increase lung VEGF expression or enhance lung development in oligohydramnios-exposed fetal rats. These results do not support the use of maternal retinoic acid to prevent oligohydramnios-induced pulmonary hypoplasia in the pseudoglandular stage.

Maternal nicotine effects on vascular endothelial growth factor expression and morphometry in rat lungs.

AIMS: Maternal smoking during pregnancy may impair pulmonary function in infants, and the exact mechanisms underlying these changes are unknown. We evaluated the effects of maternal nicotine exposure on lung VEGF expression and morphometry during the postnatal period in rats. METHODS AND RESULTS: Timed pregnant Sprague-Dawley rats were injected subcutaneously with nicotine at a dose of 2 mg/kg/day from Day 3 to Day 21 of gestation. A control group was injected with saline. Body weight, lung weight, and lung volume were comparable between control and nicotine-exposed rats. Plasma vascular endothelial growth factor (VEGF) levels and lung VEGF mRNA expression decreased with advancing age, and nicotine exposure insignificantly decreased plasma VEGF levels and lung VEGF mRNA expression, compared with the control rats during the study period. Nicotine exposure caused a significant decrease in vascular endothelial growth factor receptor (VEGFR)-2 mRNA expression, compared with the level of the control rats on Postnatal Day 1. On Postnatal Day 1, nicotine-exposed rats exhibited a significantly lower volume fraction of alveolar airspace and alveolar surface area and a significantly higher alveolar wall volume fraction than did the control rats. CONCLUSIONS: Maternal nicotine exposure during pregnancy decreases VEGF and VEGFR-2 mRNA expression and alters lung structure in the lungs of postnatal rats. Because angiogenesis is vital for alveolarization during normal lung development, these results suggest that decreased VEGF expression might be involved in the structural alterations of the developing lung after exposure to antenatal nicotine.