Development of a severity scale to assess chronic lung disease after extremely preterm birth.

Objective: Chronic lung disease of prematurity (CLDP) is a frequent complication of prematurity. We aimed to identify what clinicians believe are the most important factors determining the severity of CLDP in extremely preterm infants (<28 weeks gestational age) after discharge from the neonatal intensive care unit (NICU) through 12 months corrected age (CA), and to evaluate how these factors should be weighted for scoring, to develop a CLDP severity scale.

Study Design: Clinicians completed a three-round online survey utilizing Delphi methodology.

A genome-wide association study identifies only two ancestry specific variants associated with spontaneous preterm birth.

Preterm birth (PTB), or the delivery prior to 37 weeks of gestation, is a significant cause of infant morbidity and mortality. Although twin studies estimate that maternal genetic contributions account for approximately 30% of the incidence of PTB, and other studies reported fetal gene polymorphism association, to date no consistent associations have been identified. In this study, we performed the largest reported genome-wide association study analysis on 1,349 cases of PTB and 12,595 ancestry-matched controls from the focusing on genomic fetal signals.

The genetic predisposition to bronchopulmonary dysplasia.

Purpose Of Review: Bronchopulmonary dysplasia (BPD) is a prevalent chronic lung disease in premature infants. Twin studies have shown strong heritability underlying this disease; however, the genetic architecture of BPD remains unclear.

Recent Findings: A number of studies employed different approaches to characterize the genetic aberrations associated with BPD, including candidate gene studies, genome-wide association studies, exome sequencing, integrative omics analysis, and pathway analysis.

Maternal Asthma, Preterm Birth, and Risk of Bronchopulmonary Dysplasia.

Objective: To study the relationship between maternal asthma and the development of bronchopulmonary dysplasia (BPD).

Study Design: Using a large population-based California cohort, we investigated associations between maternal asthma and preterm birth subtype, as well as maternal asthma and BPD. We used data from 2007-2010 maternal delivery discharge records of 2 009 511 pregnancies and International Classification of Diseases, Ninth Revision codes.

Determinants of chronic lung disease severity in the first year of life; A population based study.

Objectives: First, create a clinical severity score for patients with chronic lung disease of infancy (CLDi) following neonatal intensive care unit (NICU) stay. Second, using California wide population-based data, identify factors associated with clinical severity of CLDi at 4-9 months corrected gestational age (CGA).

Study Design: Pediatric pulmonologists ranked and weighted eight factors reflecting clinical severity of CLDi.

Hospital variation and risk factors for bronchopulmonary dysplasia in a population-based cohort.

Importance: Bronchopulmonary dysplasia (BPD) remains a serious morbidity in very low-birth-weight (VLBW) infants (<1500 g). Deregionalization of neonatal care has resulted in an increasing number of VLBW infants treated in community hospitals with unknown impact on the development of BPD.

Objective: To identify individual risk factors for BPD development and hospital variation of BPD rates across all levels of neonatal intensive care units (NICUs) within the California Perinatal Quality Care Collaborative.

Combined elevated midpregnancy tumor necrosis factor alpha and hyperlipidemia in pregnancies resulting in early preterm birth.

Objective: The objective of the study was to determine whether pregnancies resulting in early preterm birth (PTB) (<30 weeks) were more likely than term pregnancies to have elevated midtrimester serum tumor necrosis factor alpha (TNF-α) levels combined with lipid patterns suggestive of hyperlipidemia.

Study Design: In 2 nested case-control samples drawn from California and Iowa cohorts, we examined the frequency of elevated midpregnancy serum TNF-α levels (in the fourth quartile [4Q]) and lipid patterns suggestive of hyperlipidemia (eg, total cholesterol, low-density-lipoproteins, or triglycerides in the 4Q, high-density lipoproteins in the first quartile) (considered independently and by co-occurrence) in pregnancies resulting in early PTB compared with those resulting in term birth (n = 108 in California and n = 734 in Iowa). Odds ratios (ORs) and 95% confidence intervals (CIs) estimated in logistic regression models were used for comparisons.

High quality genome-wide genotyping from archived dried blood spots without DNA amplification.

Spots of blood are routinely collected from newborn babies onto filter paper called Guthrie cards and used to screen for metabolic and genetic disorders. The archived dried blood spots are an important and precious resource for genomic research. Whole genome amplification of dried blood spot DNA has been used to provide DNA for genome-wide SNP genotyping.

Progress in understanding the genetics of bronchopulmonary dysplasia.

Bronchopulmonary dysplasia (BPD) is the most common chronic lung disease in infants. Its treatment imposes considerable healthcare burden and costs in the perinatal and early childhood period and patients are usually left with lifelong deficits in lung function. Evidence exists for different pathophysiologic pathways that can promote the structural changes that characterize BPD, including the impairment in alveolarization; however, there is increasing interest regarding heritable factors that may predispose very low birth weight infants to BPD.

Association of early-preterm birth with abnormal levels of routinely collected first- and second-trimester biomarkers.

Objective: The purpose of this study was to examine the relationship between typically measured prenatal screening biomarkers and early-preterm birth in euploid pregnancies.

Study Design: The study included 345 early-preterm cases (<30 weeks of gestation) and 1725 control subjects who were drawn from a population-based sample of California pregnancies who had both first- and second-trimester screening results. Logistic regression analyses were used to compare patterns of biomarkers in cases and control subjects and to develop predictive models.

Lung-derived soluble mediators are pathogenic in ventilator-induced lung injury.

Ventilator-induced lung injury (VILI) due to high tidal volume (V(T)) is associated with increased levels of circulating factors that may contribute to, or be markers of, injury. This study investigated if exclusively lung-derived circulating factors produced during high V(T) ventilation can cause or worsen VILI. In isolated perfused mouse lungs, recirculation of perfusate worsened injury (compliance impairment, microvascular permeability, edema) induced by high V(T).

NHLBI training workshop report: The vanishing pediatric pulmonary investigator and recommendations for recovery.

The adequacy of the pipeline of advanced pulmonary fellows to supply appropriately trained and committed researchers to enter academic careers was the major topic of a recently held National Heart Lung and Blood Institute NHLBI Workshop: Respiratory Medicine-Related Research Training for Adult and Pediatric Fellows. The special challenges and opportunities for the academic pediatric pulmonary trainee were discussed as part of this workshop and are discussed as a companion paper to the report by the full workshop. Surveys were conducted of pediatric chairs of academic departments and pediatric pulmonary training directors in the United States to examine the current status and opportunities for the pediatric pulmonary trainee.

Long-term terbutaline exposure stimulates alpha1-Na+-K+-ATPase expression at posttranscriptional level in rat fetal distal lung epithelial cells.

Transepithelial Na(+) transport through epithelial Na(+) channels (ENaC) on the apical membrane and Na(+)-K(+)-ATPase activity on the basolateral membrane of distal lung epithelial cells are critical for alveolar fluid clearance. Acute exposure to beta-adrenergic agonists stimulates lung fluid clearance by increasing Na(+) transport. We investigated the effects of chronic exposure to the beta(2)-adrenergic agonist terbutaline on the transepithelial Na(+) transport in rat fetal distal lung epithelia (FDLE).

NHLBI training workshop report: the vanishing pediatric pulmonary investigator and recommendations for recovery.

The adequacy of the pipeline of advanced pulmonary fellows to supply appropriately trained and committed researchers to enter academic careers was the major topic of a recently held National Heart Lung and Blood Institute NHLBI Workshop: Respiratory Medicine-Related Research Training for Adult and Pediatric Fellows. The special challenges and opportunities for the academic pediatric pulmonary trainee were discussed as part of this workshop and are presented as a companion article to the report by the full workshop. Surveys were conducted of pediatric chairs of academic departments and pediatric pulmonary training directors in the United States to examine the current status and opportunities for the pediatric pulmonary trainee.

Protease-activated receptor (Par)1 alters bioelectric properties of distal lung epithelia without compromising barrier function.

Proteinases contribute to the pathogenesis of various lung diseases, partly through activating cell surface receptors by limited proteolytic cleavage. The authors provide evidence that in primary cultures of distal lung epithelia, basolateral protease-activated receptor 1 activation rapidly reduces transepithelial resistance but does not alter paracellular permeability to small uncharged solutes. Changes in transepithelial resistance were partially blocked by ion transport inhibitors and were completely blocked by placing cells in low chloride buffer.

Glucocorticoid-mediated repression of REDD1 mRNA expression in rat fetal distal lung epithelial cells.

REDD1 (Regulated in Development and DNA Damage-1) is a stress-response gene that represses mammalian target of rapamycin (mTOR) thus decreasing protein synthesis. In contrast to studies using cell lines and adult alveolar type II (ATII) cells, we find that REDD1 mRNA levels did not increase in rat fetal distal lung epithelia (FDLE) or fetal lung fibroblasts grown in primary cultures and then exposed to 3% O2. REDD1 mRNA expression was repressed by dexamethasone (DEX) in FDLE and ATII, but induced by DEX in fibroblasts.

Pulmonary neuroendocrine cell-secreted factors may alter fetal lung liquid clearance.

The neuroendocrine system is most active at birth and may play a role in the transition from fetal to postnatal life, in particular in the lungs' transition from fluid secretion to fluid absorption. Pulmonary neuroendocrine cells do release dopamine (DA), serotonin, and gastrin-releasing peptide but their effects on lung ion and fluid transport are poorly understood. Therefore, we studied their effects on fetal distal lung explants and primary cultures of fetal distal lung epithelium (FDLE).

Global and gene-specific translational regulation in rat lung development.

During the peripartum period, the lung must respond to dramatic changes in circulating hormones, nutritional factors, and physiologic signals during its transition to becoming the organ of gas exchange. Protein synthesis consumes a significant proportion of metabolic resources and is inhibited by many environmental stresses. We hypothesized that translational control mechanisms play a role in the perinatal lung.

Visualizing water clearance in the lung with MRI.

Current indirect measurements of alveolar fluid clearance (AFC) suggest that the rate of fluid clearance correlates with morbidity and mortality in patients with pulmonary edema. In a traditional AFC-measurement, fluid laced with a tracer macromolecule is instilled into the lung and thereafter repeated samples of the instilled fluid are extracted from the lung's fluid-filled airspaces. The change in concentration of the tracer molecule indicates the AFC-rate.

Amiloride-insensitive Na+ and fluid absorption in the mammalian distal lung.

The ability of the distal lung epithelia to actively transport Na+, with Cl- and water following, from the alveolar spaces inversely correlates with morbidity and mortality of infants, children, and adults with alveolar pulmonary edema. It is now recognized, in contrast to many other Na+ transporting epithelia, that at least half of this active transport is not sensitive to amiloride, which inhibits the epithelial Na+ channel. This paper reviews amiloride-insensitive Na+ and fluid transport in the mammalian distal lung unit under basal conditions and speculates on potential explanations for this amiloride-insensitive transport.