Maturation and development of fetal pig intestinal tissue in immunodeficient mice

Purpose: This study aimed to compare the degree of maturation and development of fetal pig segmental intestinal tissue with that of spheroids created by in-vitro reaggregation of dissociated fetal intestinal cells after transplantation into immunodeficient mice. Methods: Fetal pig small intestines were transplanted as segmental grafts into the omentum and subrenal capsules of immunodeficient mice or enzymatically treated to generate single cells. Spheroids made by in-vitro reaggregation of these cells were transplanted into the subrenal capsules of immunodeficient mice. The segmental grafts and spheroids were harvested four and eight weeks after transplantation, and the structural maturity and in-vivo development of these specimens were histologically evaluated. Results: The spheroids were engrafted and supplied blood vessels from the host mice, but an intestinal layered structure was not clearly observed, and there was almost no change in size. On the other hand, the segmental grafts formed deep crypts in the mucus membrane, the inner circular layer, and outer longitudinal muscles. The crypts of the transplanted grafts harvested at eight weeks were much deeper, and the smooth muscle layer and the enteric nervous system were more mature than those of grafts harvested at the fourth week, although the intestinal peristaltic wave was not observed. Conclusions: Spheroids created from fetal small intestinal cells could not form layered structures or mature sufficiently. Conversely, segmental tissues structurally matured and developed after in-vivo transplantation and are therefore potential grafts for transplantation.

One percent of the clinical dose used for antenatal steroid therapy is sufficient to induce lung maturation when administered directly to the preterm ovine fetus.

Antenatal steroids (ANSs) are routinely administered to women judged to be at imminent risk of preterm delivery. Their principal benefit is precocious functional maturation of the preterm fetal lung. Current dosing regimens expose the mother and fetus to high steroid levels that may be unnecessary, increasing the potential risks of disruption to the maternal and fetal hypothalamic-pituitary-adrenal (HPA) axis and glucose regulation, alterations in placental function, and reduced fetal growth. Using a sheep model of pregnancy, we tested the hypothesis that direct fetal administration of an ultra-low dose course of betamethasone phosphate (∼0.33 mg) would be sufficient to elicit functional maturation of the fetal lung. A jugular catheter was installed in singleton ovine fetuses at 122-day gestation under general anesthesia. Animals were randomized to receive either: 1) fetal intravenous betamethasone phosphate to target fetal plasma betamethasone mean levels of 2 ng/mL for 26 h (fetal treatment group; n = 16); 2) fetal intravenous saline for 26 h and two maternal intramuscular injections of 0.25 mg/kg betamethasone phosphate + betamethasone acetate, simulating a standard clinical treatment (maternal treatment group; n = 12); or 3) fetal intravenous saline only for 26 h (negative control group; n = 10). Fetuses were delivered 48 h after surgery, ventilated for 30 min to allow the collection of lung function and physiological data, and euthanized. Quantitative PCR and Western blots were used to assess markers of lung maturation. The average total betamethasone phosphate dose for the fetal treatment group was 1% (0.3 mg) of the maternal treatment group (31-mg betamethasone phosphate + betamethasone acetate). At 30 min of ventilation, arterial [Formula: see text], pH, heart rate, and ventilation efficacy index (VEI) were significantly (P < 0.05) and equivalently improved in both the fetal treatment group and maternal treatment group, relative to the negative control group. Similarly, SP-A, SP-C, and AQ-5 mRNA expression was significantly higher in both the fetal treatment group and maternal treatment group, relative to negative control. Maternal steroid administration was not required to generate preterm fetal lung maturation in sheep. Using a low dose and targeting steroid treatments directly to the fetus has the potential to significantly reduce maternal exposures, while simultaneously reducing the potential risk of adverse outcomes associated with current clinical dosing regimens.

Thyroid Hormone Deficiency Suppresses Fetal Pituitary-Adrenal Function Near Term: Implications for the Control of Fetal Maturation and Parturition.

Background: The fetal hypothalamic-pituitary-adrenal (HPA) axis plays a key role in the control of parturition and maturation of organ systems in preparation for birth. In hypothyroid fetuses, gestational length may be prolonged and maturational processes delayed. The extent to which the effects of thyroid hormone deficiency in utero on the timing of fetal maturation and parturition are mediated by changes to the structure and function of the fetal HPA axis is unknown. Methods: In twin sheep pregnancies where one fetus was thyroidectomized and the other sham-operated, this study investigated the effect of hypothyroidism on circulating concentrations of adrenocorticotrophic hormone (ACTH) and cortisol, and the structure and secretory capacity of the anterior pituitary and adrenal glands. The relative population of pituitary corticotrophs and the masses of the adrenal zones were assessed by immunohistochemical and stereological techniques. Adrenal mRNA abundances of key steroidogenic enzymes and growth factors were examined by quantitative polymerase chain reaction. Results: Hypothyroidism in utero reduced plasma concentrations of ACTH and cortisol. In thyroid-deficient fetuses, the mass of corticotrophs in the anterior pituitary gland was unexpectedly increased, while the mass of the zona fasciculata and its proportion of the adrenal gland were decreased. These structural changes were associated with lower adrenocortical mRNA abundances of insulin-like growth factor (IGF)-I and its receptor, and key steroidogenic enzymes responsible for glucocorticoid synthesis. The relative mass of the adrenal medulla and its proportion of the adrenal gland were increased by thyroid hormone deficiency in utero, without any change in expression of phenylethanolamine N-methyltransferase or the IGF system. Conclusions: Thyroid hormones are important regulators of the structure and secretory capacity of the pituitary-adrenal axis before birth. In hypothyroid fetuses, low plasma cortisol may be due to impaired adrenocortical growth and steroidogenic enzyme expression, secondary to low circulating ACTH concentration. Greater corticotroph population in the anterior pituitary gland of the hypothyroid fetus indicates compensatory cell proliferation and that there may be abnormal corticotroph capacity for ACTH synthesis and/or impaired hypothalamic input. Suppression of the development of the fetal HPA axis by thyroid hormone deficiency may contribute to the delay in fetal maturation and delivery observed in hypothyroid offspring.

Ultrasonographic analysis of fetal gastrointestinal motility during the peripartum period in the dog.

The aim of this study was to investigate fetal gastrointestinal motility (FGM) of dogs using ultrasonic imaging and its association with vaginal and rectal temperature, serum progesterone concentrations and fetal heart rate. Pregnant bitches were examined after day 54 of gestation and there were determinations of vaginal and rectal temperature and serum progesterone concentrations. The fetal abdomen was evaluated for 30 s using longitudinal and transversal assessments, and FGM was scored as 0 (no peristalsis) or 1 (evident peristalsis). Number of fetuses with a 1 or 0 score were determined for each bitch (number and the percentage of fetuses with FGM). A total of 135 FGM measurements were recorded. There was FGM in 0/3, 0/6, 1/6 (16.7 %), 3/20 (15 %), 5/18 (27.3 %), 18/28 (64.3 %), 12/17 (70.6 %), 14/22 (63.6 %), 6/9 (66.7 %), 4/6 (66.7 %) fetuses from day -9 until 0 preceding parturition, respectively. In the last 5 days before parturition, 63.3 % of fetuses had FGM. Vaginal and rectal temperature were strongly and positively correlated (P < 0.001). Vaginal temperature was positively correlated with progesterone concentrations and fetal heart rate (P < 0.01), and there was a small negative correlation with FGM (r = -0.331, P < 0.05). Due to ease of data collection, the assessment of FGM is a valuable procedure for evaluation of fetal maturity in dogs. Vaginal and rectal temperatures are reliable variables to be assessed during the last week of pregnancy for estimating the time of parturition.

Ecografía doppler de la arteria pulmonar como indicador de madurez pulmonar fetal, Cuenca ­ Ecuador / Doppler ultrasound of the pulmonary artery as fetal lung maturity indicator, Cuenca - Ecuador

Introducción: la flujometría de la arteria pulmonar en fetos sanos puede ser un estudio predictor de la madurez pulmonar, lo que conlleva a un impacto en la disminución de la mortalidad perinatal.Objetivo: establecer el índice de tiempo de aceleración/tiempo de eyección de la arteria pulmonar (TA/TE) como un indicador de madurez pulmonar fetal en gestantes entre 26 y 40 semanas de gestación (SG), usuarias del Hospital Especializado Fundación Humanitaria Pablo Jaramillo Crespo, periodo 2017.Métodos: estudio de validación de prueba diagnóstica. Se evaluó la flujometría de la arteria pulmonar por ecografía doppler en 300 fetos sanos de gestantes entre 15 y 45 años de edad. Para la recolección de datos se utilizó encuestas y para la determinación de la validez se usó los estadísticos sensibilidad (S), especificidad (E), valor predictivo positivo (VPP) y valor predictivo negativo (VPN). Resultados: el valor del índice TA/TE de la arteria pulmonar fue 0.216 para las gestantes entre 26-28 SG; de 0.253 entre 29-31 SG; de 0.279 entre 32-34 SG; de 0.315 para las gestantes entre 35-37 SG y de 0.349 entre 38-40 SG. Las 37 SG en punto de corte fue de 0.320; el área ROC fue 0.98 con una S: 95.2%, E: 97.2%. VPP 93.0% y VPN 98.1%.Conclusiones: el índice TA/TE de la arteria pulmonar demostró correlación con la edad gestacional. Un índice TA/TE de 0.320, como punto de corte, predice madurez pulmonar fetal (AU);

Introduction: pulmonary artery flow metric in healthy fetuses can be a predictive study of lung maturity, which leads to an impact on the decrease in perinatal mortality.Objective: to establish the ratio of pulmonary artery acceleration time to ejection time (AT/ET) as an indicator of fetal lung maturity in pregnant women from 26 to 40 weeks of gestation (WG), users of the "Hospital Especializado Fundación Humanitaria Pablo Jaramillo Crespo", period 2017.Methods: A validity study of diagnostic tests was carried out. Pulmonary artery flow metric was evaluated by Doppler ultrasound in 300 healthy fetuses of pregnant women between 15 to 45 years old. Surveys were used to collect data. Sensitivity (S), specificity (E), positive predictive value (PPV) and negative predictive value (NPV) were used to determine validity.Results: the value of the TA / TE index of the pulmonary artery was 0.216 for pregnant women between 26-28 WG; of 0.253 between 29-31 WG; 0.279 between 32-34 WG; 0.315 for pregnant women between 35-37 WG and 0.349 between 38-40 WG. The 37 WG at the cut-off point was 0.320; the ROC area was 0.98 with a S: 95.2%, E: 97.2%. The PPV 93.0% and NPV 98.1%.Conclusions: the AT/ET ratio of pulmonary artery showed correlation with gestational age. An AT/ET ratio of 0.320, as a cut-off point, predicts fetal lung maturity (AU);

Variability in the efficacy of a standardized antenatal steroid treatment was independent of maternal or fetal plasma drug levels: evidence from a sheep model of pregnancy.

BACKGROUND: Administration of antenatal steroids is standard of care for women assessed to be at imminent risk of preterm delivery. There is a marked variation in antenatal steroid dosing strategy, selection for treatment criteria, and agent choice worldwide. This, combined with very limited optimization of antenatal steroid use per se, means that treatment efficacy is highly variable, and the rate of respiratory distress syndrome is decreased to perhaps as low as 40%. In some cases, antenatal steroid use is associated with limited benefit and potential harm. OBJECTIVE: We hypothesized that individual differences in maternofetal steroid exposure would contribute to observed variability in antenatal steroid treatment efficacy. Using a chronically catheterized sheep model of pregnancy, we aimed to explore the relationship between maternofetal steroid exposure and antenatal steroid treatment efficacy as determined by functional lung maturation in preterm lambs undergoing ventilation. STUDY DESIGN: Ewes carrying a single fetus underwent surgery to catheterize a fetal and maternal jugular vein at 119 days' gestation. Animals recovered for 24 hours before being randomized to either (1) a single maternal intramuscular injection of 2 mL saline (negative control group, n=10) or (2) a single maternal intramuscular injection of 0.25 mg/kg betamethasone phosphate plus acetate (antenatal steroid group, n=20). Serial maternal and fetal plasma samples were collected from each animal after 48 hours before fetuses were delivered and ventilated for 30 minutes. Total and free plasma betamethasone concentration was measured by mass spectrometry. Fetal lung tissue was collected for analysis using quantitative polymerase chain reaction. RESULTS: One animal from the control group and one animal from the antenatal steroid group did not complete their treatment protocol and were removed from analyses. Animals in the antenatal steroid group were divided into a responder subgroup (n=12/19) and a nonresponder subgroup (n=7/19) using a cutoff of partial pressure of arterial CO2 at 30-minute ventilation within 2 standard deviations of the mean value from saline-treated negative control group animals. Although antenatal steroid improved fetal lung maturation in the undivided antenatal steroid group and in the responder subgroup both physiologically (blood gas- and ventilation-related data) and biochemically (messenger ribonucleic acid expression related to fetal lung maturation), these values did not improve relative to saline-treated control group animals in the antenatal steroid nonresponder subgroup. No differences in betamethasone distribution, clearance, or protein binding were identified between the antenatal steroid responder and nonresponder subgroups. CONCLUSION: This study correlated individual maternofetal steroid exposures with preterm lung maturation as determined by pulmonary ventilation. Herein, approximately 40% of preterm lambs exposed to antenatal steroids had lung maturation that was not significantly different to saline-treated control group animals. These nonresponsive animals received maternal and fetal betamethasone exposures identical to animals that had a significant improvement in functional lung maturation. These data suggest that the efficacy of antenatal steroid therapy is not solely determined by maternofetal drug levels and that individual fetal or maternal factors may play a role in determining treatment outcomes in response to glucocorticoid signaling.

Bronchopulmonary dysplasia: Pathophysiology and potential anti-inflammatory therapies.

Inflammation of the preterm lungs is key to the pathogenesis of bronchopulmonary dysplasia (BPD), whether it arises as a consequence of intrauterine inflammation or postnatal respiratory management. This review explores steroidal and non-steroidal therapies for reducing neonatal pulmonary inflammation, aimed at treating or preventing BPD.

Early onset children's interstitial lung diseases: Discrete entities or manifestations of pulmonary dysmaturity?

Interstitial lung diseases in children (chILD) are rare and diverse. The current classifications include a group of early onset chILD specific to infancy, namely neuro-endocrine cell hyperplasia of infancy (NEHI), pulmonary interstitial glycogenosis (PIG) and the alveolar capillary-congenital acinar dysplasia (ACD-CAD) spectrum, as well as alveolar growth disorders. NEHI and PIG cells are seen in the normal developing foetal lung. We hypothesise that these conditions are in fact overlapping manifestations of pulmonary dysmaturity, respectively of airway, mesenchymal and vascular elements, rather than discrete clinical conditions in their own right. Clinically, these present as respiratory distress in early life. Mild cases rightly never undergo lung biopsy, and for these the clinical description 'persistent tachypnoea of infancy' has been proposed. In terms of pathology, we reviewed current literature, which showed that NEHI cells decline with age, and are not specific to NEHI, which we confirmed by unpublished re-analysis of a second dataset. Furthermore, specific genetic disorders which affect pulmonary maturation lead to a histological picture indistinguishable from NEHI. PIG and ACD-CAD are also associated with pulmonary growth disorders, and manifestations of PIG and NEHI may be present in the same child. We conclude that, contrary to current classifications, NEHI, PIG, and ACD-CAD should be considered as overlapping manifestations of pulmonary dysmaturation, frequently associated with disorders of alveolar growth, rather than as separate conditions. Identification of one of these patterns should be the start, not the end of the diagnostic journey, and underlying in particular genetic causes should be sought.

Characterization of a reversible thermally-actuated polymer-valve: A potential dynamic treatment for congenital diaphragmatic hernia.

BACKGROUND: Congenital diaphragmatic hernia (CDH) is a fetal defect comprising an incomplete diaphragm and the herniation of abdominal organs into the chest cavity that interfere with fetal pulmonary development. Though the most promising treatment for CDH is via interventional fetoscopic tracheal occlusion (TO) surgery in-utero, it has produced mixed results due to the static nature of the inserted occlusion. We hypothesize that a suitable noninvasively-actuatable, cyclic-release tracheal occlusion device can be developed to enable dynamic tracheal occlusion (dTO) implementation. OBJECTIVE: To conduct an in-vitro proof-of-concept investigation of the construction of thermo-responsive polymer valves designed for targeted activation within a physiologically realizable temperature range as a first step towards potential development of a noninvasively-actuatable implantable device to facilitate dynamic tracheal occlusion (dTO) therapy. METHODS: Six thermo-responsive polymer valves, with a critical solution temperature slightly higher than normal physiological body temperature of 37°C, were fabricated using a copolymer of n-isopropylacrylamide (NIPAM) and dimethylacrylamide (DMAA). Three of the valves underwent ethylene oxide (EtO) sterilization while the other three served as controls for EtO-processing compatibility testing. Thermal response actuation of the valves and their steady-state flow performances were evaluated using water and caprine amniotic fluid. RESULTS: All six valves consisting of 0.3-mole fraction of DMAA were tested for thermal actuation of caprine amniotic fluid flow at temperatures ranging from 30-44°C. They all exhibited initiation of valve actuation opening at ~40°C with full completion at ~44°C. The overall average coefficient of variation (CV) for the day-to-day flow performance of the valves tested was less than 12%. Based on a Student t-test, there was no significant difference in the operational characteristics for the EtO processed versus the non-EtO processed valves tested. CONCLUSIONS: We successfully fabricated and demonstrated physiological realizable temperature range operation of thermo-responsive polymer valves in-vitro and their suitability for standard EtO sterilization processing, a prerequisite for future in-vivo surgical implantation testing.

No. 364-Antenatal Corticosteroid Therapy for Improving Neonatal Outcomes.

OBJECTIVE: To assess the benefits and risks of antenatal corticosteroid therapy for women at risk of preterm birth or undergoing pre-labour Caesarean section at term and to make recommendations for improving neonatal and long-term outcomes. OPTIONS: To administer or withhold antenatal corticosteroid therapy for women at high risk of preterm birth or women undergoing pre-labour Caesarean section at term. OUTCOMES: Perinatal morbidity, including respiratory distress syndrome, intraventricular hemorrhage, bronchopulmonary dysplasia, infection, hypoglycemia, somatic and brain growth, and neurodevelopment; perinatal mortality; and maternal morbidity, including infection and adrenal suppression. INTENDED USERS: Maternity care providers including midwives, family physicians, and obstetricians. TARGET POPULATION: Pregnant women. EVIDENCE: Medline, PubMed, Embase, and the Cochrane Library were searched from inception to September 2017. Medical Subject Heading (MeSH) terms and key words related to pregnancy, prematurity, corticosteroids, and perinatal and neonatal mortality and morbidity were used. Statements from professional organizations including that of the National Institutes of Health, the American College of Obstetricians and Gynecologists, the Society for Maternal Fetal Medicine, the Royal College of Obstetricians and Gynaecologists, and the Canadian Pediatric Society were reviewed for additional references. Randomized controlled trials conducted in pregnant women evaluating antenatal corticosteroid therapy and previous systematic reviews on the topic were eligible. Evidence from systematic reviews of non-experimental (cohort) studies was also eligible. VALIDATION METHODS: This Committee Opinion has been reviewed and approved by the Maternal-Fetal Medicine Committee of the SOGC and approved by SOGC Council. BENEFITS, HARMS, AND/OR COSTS: A course of antenatal corticosteroid therapy administered within 7 days of delivery significantly reduces perinatal morbidity/mortality associated with preterm birth between 24 + 0 and 34 + 6 weeks gestation. When antenatal corticosteroid therapy is given more than 7 days prior to delivery or after 34 + 6 weeks gestation, the adverse effects may outweigh the benefits. Evidence on long-term effects is scarce, and potential neurodevelopment harms are unquantified in cases of late preterm, term, and repeated exposure to antenatal corticosteroid therapy. GUIDELINE UPDATE: Evidence will be reviewed 5 years after publication to evaluate the need for a complete or partial update of the guideline. If important evidence is published prior to the 5-year time point, an update will be issued to reflect new knowledge and recommendations. SPONSORS: The guideline was developed with resources provided by the Society of Obstetricians and Gynaecologists of Canada with support from the Canadian Institutes of Health Research (APR-126338). SUMMARY STATEMENTS: RECOMMENDATIONS: Gestational Age Considerations Agents, Dosage, Regimen, and Target Timing Subpopulations and Special Consideration.

Estudio Descriptivo: Variación del Índice de Tiempo de Aceleración/Tiempo de Eyección Sistólico del Tronco de la Arteria Pulmonar por Efecto de Maduración Pulmonar con Corticoides en Fetos Prematuros. Clínica Humanitaria. Cuenca ­ Ecuador, 2016 / Descriptive Research: Variation of Acceleration Time/Ejection Time Index of the Trunk of the Pulmonary Arteries Due to the Lung Maturation Effect of Corticosteroids on Preterm Fetus. Clínica Humanitaria, 2016

INTRODUCCIÓN: El nacimiento prematuro representa un problema de salud pública importante a nivel mundial y en especial en países en vías de desarrollo. En el Ecuador, en el año 2014, la tasa de mortalidad infantil fue de 8.35 defunciones infantiles por cada 1 000 nacimientos y las principales causas de mortalidad infantil fueron la dificultad respiratoria del recién nacido y los trastornos con duración corta de la gestación. MÉTODOS: El presente es un estudio observacional, descriptivo y longitudinal, realizado con una muestra censal o por conveniencia de 36 mujeres que cursaron entre 24 y 34 semanas de gestación con feto único vivo, riesgo de parto pretérmino e indicación de maduración pulmonar con corticoides. Se recogió información de flujometría fetal para determinar el efecto del uso de corticoides para maduración pulmonar. Se realizaron pruebas de normalidad Shapiro-Wilk en los resultados obtenidos antes y después de la maduración pulmonar. Para el procesamiento de los datos se utilizaron los programas Microsoft Excel® y SPSS® v.20. RESULTADOS: La edad media de este grupo fue de 25.64 años, las media de semanas de gestación fue de 31.2. La patología más frecuente fue amenaza de parto pretérmino con un 72 %, seguida de ruptura prematura pretérmino de membranas con un 13.9 %. Existió una diferencia estadísticamente significativa entre los valores de los índices Tiempo de Acelereción / Tiempo de Eyección antes y después de la maduración pulmonar (0.272 ms y 0.310 ms, respectivamente; P < 0.0001). CONCLUSIONES: La comparación de las medias de los índices Tiempo de Acelereción / Tiempo de Eyección del tronco de la arteria pulmonar pre y post maduración pulmonar con corticoides evidenció una diferencia significativa importante. Los hallazgos sugieren que la maduración pulmonar con corticoides es eficaz para mejorar el flujo de arteria pulmonar en fetos prematuros.

BACKGROUND: Premature birth represents an important public health problem worldwide and especially in developing countries. In Ecuador (2014), the infant mortality rate reached 8.35 deaths per 1 000 births and their main causes were newborns respiratory distress and gestation period short-term disorders. METHODS: This is an observational longitudinal descriptive research; it was performed in a convenience sample that included 26 singlet on pregnant women between 24 and 34 weeks of gestation. They also were on risk of preterm delivery and had indication of lung maturation with corticosteroids. Information of the fetal pulmonary arteries flow was collected to determine the effect of corticosteroids in pulmonary maturation. RESULTS: Mean age was 25.64 years and had an average gestation of 31.2 weeks. Most common diseases were preterm labor threat (72 %) and premature rupture of membranes (13.9 %). There was a statistically significant difference between the values of Acceleration Time / Ejection Time indexes before and after lung maturation (0.272 ms vs. 0.310 ms respectively; P < 0.0001). CONCLUSIONS: Comparison of Acceleration Time / Ejection Time indexes from the trunk of the pulmonary arteries before and after lung maturation evidenced an important significant difference. The findings suggest that pulmonary maturation with corticosteroids is effective to improve the pulmonary arteries flow of preterm fetus.

hPSC-derived lung and intestinal organoids as models of human fetal tissue.

In vitro human pluripotent stem cell (hPSC) derived tissues are excellent models to study certain aspects of normal human development. Current research in the field of hPSC derived tissues reveals these models to be inherently fetal-like on both a morphological and gene expression level. In this review we briefly discuss current methods for differentiating lung and intestinal tissue from hPSCs into individual 3-dimensional units called organoids. We discuss how these methods mirror what is known about in vivo signaling pathways of the developing embryo. Additionally, we will review how the inherent immaturity of these models lends them to be particularly valuable in the study of immature human tissues in the clinical setting of premature birth. Human lung organoids (HLOs) and human intestinal organoids (HIOs) not only model normal development, but can also be utilized to study several important diseases of prematurity such as respiratory distress syndrome (RDS), bronchopulmonary dysplasia (BPD), and necrotizing enterocolitis (NEC).

The extracellular calcium-sensing receptor regulates human fetal lung development via CFTR.

Optimal fetal lung growth requires anion-driven fluid secretion into the lumen of the developing organ. The fetus is hypercalcemic compared to the mother and here we show that in the developing human lung this hypercalcaemia acts on the extracellular calcium-sensing receptor, CaSR, to promote fluid-driven lung expansion through activation of the cystic fibrosis transmembrane conductance regulator, CFTR. Several chloride channels including TMEM16, bestrophin, CFTR, CLCN2 and CLCA1, are also expressed in the developing human fetal lung at gestational stages when CaSR expression is maximal. Measurements of Cl(-)-driven fluid secretion in organ explant cultures show that pharmacological CaSR activation by calcimimetics stimulates lung fluid secretion through CFTR, an effect which in humans, but not mice, was also mimicked by fetal hypercalcemic conditions, demonstrating that the physiological relevance of such a mechanism appears to be species-specific. Calcimimetics promote CFTR opening by activating adenylate cyclase and we show that Ca(2+)-stimulated type I adenylate cyclase is expressed in the developing human lung. Together, these observations suggest that physiological fetal hypercalcemia, acting on the CaSR, promotes human fetal lung development via cAMP-dependent opening of CFTR. Disturbances in this process would be expected to permanently impact lung structure and might predispose to certain postnatal respiratory diseases.

Structural and molecular regulation of lung maturation by intratracheal vascular endothelial growth factor administration in the normally grown and placentally restricted fetus.

Inhibition of hypoxia signalling leads to respiratory distress syndrome (RDS), whereas administration of vascular endothelial growth factor (VEGF), the most widely characterized hypoxia responsive factor, protects from RDS. In the lung of the chronically hypoxaemic placentally restricted (PR) fetus, there is altered regulation of hypoxia signalling. This leads to reduced surfactant maturation in late gestation and provides evidence for the increased risk of RDS in growth restricted neonates at birth. We evaluated the effect of recombinant human VEGF administration with respect to bypassing the endogenous regulation of hypoxia signalling in the lung of the normally grown and PR sheep fetus. There was no effect of VEGF administration on fetal blood pressure or fetal breathing movements. We examined the effect on the expression of genes regulating VEGF signalling (FLT1 and KDR), angiogenesis (ANGPT1, AQP1, ADM), alveolarization (MMP2, MMP9, TIMP1, COL1A1, ELN), proliferation (IGF1, IGF2, IGF1R, MKI67, PCNA), inflammation (CCL2, CCL4, IL1B, TNFA, TGFB1, IL10) and surfactant maturation (SFTP-A, SFTP-B, SFTP-C, SFTP-D, PCYT1A, LPCAT, LAMP3, ABCA3). Despite the effects of PR on the expression of genes regulating airway remodelling, inflammatory signalling and surfactant maturation, there were very few effects of VEGF administration on gene expression in the lung of both the normally grown and PR fetus. There were, however, positive effects of VEGF administration on percentage tissue, air space and numerical density of SFTP-B positive alveolar epithelial cells in fetal lung tissue. These results provide evidence for the stimulatory effects of VEGF administration on structural maturation in the lung of both the normally grown and PR fetus.

Prenatal interventions to prevent bronchopulmonary dysplasia in animal models: a systematic review.

OBJECTIVE: The objective of this study is to identify and systematically review in vivo animal studies on antenatal medical interventions to prevent bronchopulmonary dysplasia. METHODS: An automated literature search was conducted using MEDLINE (Pubmed) and Embase including all studies using Medical Subject Headings (MeSH) and keywords following a step-by-step approach. All in vivo prenatal intervention studies in animal models mimicking key aspects of the pathophysiology of bronchopulmonary dysplasia were included. In view of relevance of the findings, an additional criterion was that outcomes at 48 h of life or beyond were available. The PRISMA statement concerning systemic reviews was applied and a quality checklist developed by the CAMARADES group was used. RESULTS: In total, 518 abstracts were identified yet only eight studies were eligible for further analysis. Four studies involved administration of glucocorticoids, the other studies described therapy with epidermal growth factor, interleukin 1b, beta-naphthoflavone, or vitamin D. Outcomes were survival, pulmonary histology, lung function, and/or biochemical analysis. CONCLUSIONS: Though many in vivo experimental studies in animal models for bronchopulmonary dysplasia have been done, only few have looked into the effect of prenatal interventions and measured outcomes after at least 48 h of life. Most involve the use of antenatal glucocorticoids, although still only four.

Lung maturity in esophageal atresia: Experimental and clinical study.

INTRODUCTION: Esophageal atresia and tracheoesophageal fistula (EA-TEF) survivors suffer respiratory morbidity of unclear pathogenesis. Defective lung morphogenesis has been described in the rat model. This study examined fetal lung growth and maturity in rats and patients with EA-TEF. METHODS: Pregnant rats received either adriamycin or vehicle. Control and adriamycin-exposed lungs, with and without EA-TEF, were weighed and processed for RT-PCR, DNA quantification, immunofluorescence and immunoblot analysis of TTF1, VEGF, Sp-B, and α-sma. Twenty human lungs were also processed for immunofluorescence and Alcian-blue staining. RESULTS: Lungs from fetuses with EA-TEF (E21) showed decreased total DNA; FGF7 and TTF1 mRNA expressions were upregulated at E15 and E18, respectively. Protein expression and immunofluorescent distribution of maturity markers were similar. Lungs from stillborns with EA-TEF showed decreased epithelial expression of Sp-B and VEGF whereas those from newborns tended to have less Sp-B and more VEGF and mucous glands. DISCUSSION: The lungs of rats with EA-TEF were hypoplastic but achieved near-normal maturity. Stillborns with EA-TEF exhibited an apparently disturbed differentiation of the airway epithelium. Newborns with EA-TEF demonstrated subtle differences in the expression of differentiation markers, and increased number of mucous glands that could influence postnatal respiratory adaptation and explain some respiratory symptoms of EA-TEF survivors.

Perfil ecográfico de madurez pulmonar fetal: quince años de experiencia en el Hospital Nacional Arzobispo Loayza / Sonographic fetal lung maturity profile: fifteen years of experience in the National Hospital Loayza Archbishop

Evaluar la capacidad predictiva del Perfil de Madurez Pulmonar Fetal Ecográfico en comparación con el Test de Clements para predecir de manera confiable la Madurez Fetal, evitando las potenciales complicaciones de la amniocentesis, y las limitaciones que hay en nuestro medio para el uso de marcadores bioquímicos de predicción de madurez fetal, como el test de la Lecitina/Esfingomielina, entre otros. Material y Métodos: estudio descriptivo, prospectivo de evaluación de parámetros diagnósticos para determinar la madurez pulmonar fetal usando como procedimientos la ecografía y la amniocentesis, y comparándolo con el resultado perinatal como patrón de oro. Se estudió 1200 gestantes hospitalizadas en el Servicio de alto riesgo obstétrico del Hospital Arzobispo Loayza desde Diciembre 1995 a Diciembre 2010 a quienes se les realizó el perfil de madurez pulmonar ecográfico (PEMPEI con cinco parámetros: Grado de madurez placentaria, patrón intestinal, relación pulmón-hígado, epifisis femoral distal, y edad gestacional compuesta por biometría múltiple. A todas se les realizó amniocentesis para determinar test de elements (tres tubos) en líquido amniótico. Se evaluó el resultado perinatal al terminar la gestación por indicación obstétrica a más tardar antes de las 48 horas de realizadas las pruebas. Resultados: Se obtuvieron 1251 RN, ya que hubo 50 embarazos múltiples. El diagnóstico más frecuente fue preeclampsia, la EG por Capurro en promedio fue 34.4 + 1.6 semanas (rango de 27 a 36 semanas), el peso de los RN en promedio fue de 21364 580 gr (rango de 1050 a 2840 gr). En total 80 RN presentaron Enfermedad de Membrana Hialina, diagnosticadas por criterie clínicos y radiológicos. La predicción de resultados tanto para el PEMPE, y el test de Clements fueron respectivamente: especificidad (97.35%, 85.74%), sensibilidad (86.25%, 75.0%), valor predictivo negativo (69.0%, 26.43%), valor predictive positivo (99.04%, 98.04%)...

To evaluate the predictive capacity of Sonographic Fetal Lung Maturity Profile compared to the Clements test to reliably predict the Fetal Maturity, avoiding potential complications of amniocentesis, and constraints that exist in oui environment for the use of markers prediction biochemical fetal maturity test as lecithin / sphingomyelin among others. Material and Methods: Descriptive, prospective study evaluating diagnostic parameters to determine fetal lung maturitn using ultrasound and amniocentesis procedures, and comparing perinatal outcome as the gold standard. 1200 pregnanii women hospitalized with high obstetric risk at Hospital Nacional Arzobispo Loayza from December 1995 to December 2011 were studied. They underwent sonographic profile of lung maturity with five parameters; liver, distal femoral epiphysis, anci gestational age composed of multiple biometrics. All had an amniocentesis test to determine clement test in amniotic fluic( (three tubes). lf, by obstetric indication, pregnancy was ended within 48 hours of testing, perinatal outcome was evaluatedi Results: 1251 newborns were studied, as there were 50 multiple pregnancies. The most common diagnosis was preeclampsiar Average gestational age by Capurro was 34.4 + 1.6 weeks (range 27-36 weeks), the weight of the newborns, in average, waii 2136 + 580 gr (range 1050-2840 g). In total 80 newborns presented Hyaline Membrane Disease, diagnosed by clinical ans' radiological criteria. The prediction results for both sonographic fetal lung maturity and Clements test were: specificitir (97.35%, 85.74%), sensitivity (86.25%, 75.0%), negative (69.0%, 26.43%) predictive value, positive predictive value (99.041( 98.04%) respectively...

Cystatin C in newborns: a promising renal biomarker in search for standardization and validation.

OBJECTIVE: Neonatologists still commonly use creatinine as a proxy for renal clearance, despite issues related to neonatal (patho)physiology and methodology (assay variability). Cystatin C (CysC) has been suggested to be a more reliable biomarker, but assay related differences have also been reported in children and adults. We are unaware of any review on the assay related impact on CysC reference values in newborns. METHODS: A structured literature search was performed on published CysC values in (pre)term neonates. RESULTS: The extensive range (>5-fold) in serum CysC observations in neonates in part relates to the fact that CysC concentrations are higher at birth with subsequent decrease and that CysC concentrations are higher in preterm compared to term neonates. The CysC assay matters while disease characteristics also affect CysC values, but not always in the predicted direction. CONCLUSIONS: Similar to creatinine, the extensive CysC range in neonates is only in part explained by renal (patho)physiology. Its applicability in neonatal medicine can be further improved by use of assay specific reference values, adapted to neonatal renal physiology (e.g. weight, age) and should be compared to a gold standard such as inulin clearance.