Hematological and biochemical parameters of premature kids of goats subjected to different dexamethasone protocols

ABSTRACT: Corticosteroid therapy has been used for ruminants to allow lung maturation and the birth of premature babies. However, when considering laboratory analyses of these animals, very little data is available regarding hematological and biochemical patterns, especially for premature goats, and the effects of corticotherapy on these parameters are unknown. In this context, the objective of this study was to evaluate the hematological and biochemical parameters during the first hours of life of premature kids from goats subjected to different dexamethasone protocols. For this, the goats were divided into four groups: group I, goats that received 20 mg of dexamethasone at 139 days of gestation; group II, 2 mg of dexamethasone from the 133rd to 136th day of gestation, 4 mg from the 137th to 139th, and 20 mg on the 140th; group III, 16 mg of dexamethasone from the 139th day, with repeated doses every 12 h until elective surgery; and group IV, goats that received 4, 8, 16, and 20 mg of dexamethasone at 137, 138, 139, and 140 days of gestation, respectively. Blood samples were obtained at birth (T0h) and after 1 (T1h), 12 (T12h), 24 (T24h), and 48 h (T48h) of life for hemogram and serum biochemistry assessment of urea, creatinine, total protein (PT), and gamma-glutamyltransferase (GGT). PT levels and GGT activity were lower at birth in all groups and rose after colostrum ingestion. The creatinine values for all the experimental groups did not differ between T0h and T1h; however, they decreased in the subsequent moments. Except for group I, urea concentrations were higher at T48h than at T1h. The red blood cell, hemoglobin, hematocrit, and mean corpuscular hemoglobin counts decreased over time. The total leukocyte count behaved differently in different experimental groups, and was influenced by the levels of dexamethasone, mainly due to the change in the counts of segmented neutrophils and lymphocytes. It was concluded that significant changes in the hematological and biochemical parameters occur in the first hours of life of premature kids, and that the treatment of goats with dexamethasone can affect these parameters in a dose-dependent manner.

Impact of antenatal glucocorticoid exposure on the activity of the stress system, cognition and behavior in 8 to 9-year-old children: a clinical cohort study

Objective: To determine stress-sensitivity and neurodevelopmental outcome in 8- to 9-year-old children following antenatal exposure to glucocorticoid (GC) prophylaxis for neonatal respiratory distress syndrome. Design: Clinical cohort study. Setting: University-based obstetric clinic in Central Germany. Population: 31 term or near-term born children whose mothers received single or multiple courses of betamethasone (BM) to induce fetal lung maturation in threatened preterm birth compared to 39 non-exposed children. Methods: Multi-system assessment of the individual stress response together with an analysis of cognitive, behavioral and electrocortical functioning. Main Outcome Measures: Activity of the hypothalamus-pituitary-adrenal axis (HPAA, primary outcome domain) and the autonomic nervous system (ANS, secondary outcome domain) including markers of heart rate variability (HRV). Additional endpoints were the cognitive performance (IQ) and attention-deficit/hyperactivity disorder (ADHD) core symptoms. Results: HPAA activity was not affected by antenatal GC-exposure. ANS activity in GC-exposed children shifted towards a higher parasympathetic tone reflected by a higher overall high-frequency band power of HRV (1313 vs. 762 msec2/Hz, p=0.03). BM-exposed children had lower cognitive performance (IQ 96.9 vs. 108.0, p<0.01) and a marginally higher ADHD score (FBB-ADHD scale 5.5 vs. 4.6 points, p=0.04). A monotonic dose-response relationship between GC-exposure and stress-induced activity of the ANS and IQ was estimated post-hoc. Conclusions: Antenatal exposure to supraphysiological concentrations of BM in the context of threatened preterm birth was associated with multidimensional changes in stress-sensitivity and neurodevelopment in later life. As these changes may be dose-dependent, antenatal GC prophylaxis should be used at the minimum effective dose after a careful risk-benefit assessment.

The administration of a pre-digested fat enriched formula prevents NEC-induced lung injury in mice

Necrotizing enterocolitis (NEC) is a devastating gastrointestinal disease of prematurity that typically develops after the administration of infant formula, suggesting a link between nutritional components and disease development. One of the most significant complications that develops in patients with NEC is severe lung injury. We have previously shown that the administration of a nutritional formula that is enriched in pre-digested triglycrides that do not require lipase action can significantly reduce the severity of NEC in a mouse model. We now hypothesize that this 'pre-digested fat system (PDF)' may reduce NEC-associated lung injury. In support of this hypothesis, we now show that rearing newborn mice on a nutritional formula based on the 'pre-digested fat (PDF) system’ promotes lung development, as evidenced by increased tight junctions and surfactant protein expression. Mice who were administered this 'PDF fat system’ were significantly less vulnerable to the development of NEC-induced lung inflammation, and the administration of the 'PDF fat system’ conferred lung protection. In seeking to define the mechanisms involved, the administration of the PDF system’ significantly enhanced lung maturation and reduced the production of reactive oxygen species (ROS). These findings suggest that the PDF system protects the development of NEC-induced lung injury through effects on lung maturation and reduced reactive oxygen species in the lung, and also increase lung maturation in non-NEC mice.

Extra-corporeal membrane oxygenation and emergency C-section for a pregnant COVID-19 positive patient

Introduction: Data on extra-corporeal membrane oxygenation (ECMO) therapy for pregnant patients with Coronavirus 2019 (COVID-19) infection are limited. Here we report a case of an emergency cesarean section performed while the COVID-19 positive mother was on ECMO support. Case report: A 36-year-old COVID-19 positive patient at 26 weeks gestational age presented with respiratory failure requiring extra-corporeal membrane oxygenation therapy. Nine days later fetal distress demanded an emergency C-section. After 5 weeks on ECMO, the patient was weaned off. Both mother and child were discharged. Discussion: The decision to perform an urgent C-section is one that requires meticulous thought from the attending team. Pulmonary maturation is key as pregnancy may need to be terminated at any time during ECMO. Conclusion: Data on ECMO support for pregnant patients with COVID-19 infection are scarce. Best results can be achieved ensuring adequate anticoagulation, meticulous choice of cannulas, continued fetal monitoring, early lung maturation, and precision timing of delivery.

Lung development and immune status under chronic LPS exposure in rat pups with and without CD26/DPP4 deficiency

Dipeptidyl-peptidase IV (CD26), a multifactorial integral type II protein, is expressed in the lungs during development and is involved in inflammation processes. We tested whether daily LPS administration influences the CD26-dependent retardation in morphological lung development and induces alterations in the immune status. Newborn Fischer rats with and without CD26 deficiency were nebulized with 1 µg LPS/2 ml NaCl for 10 min from days postpartum (dpp) 3 to 9. We used stereological methods and fluorescence activated cell sorting (FACS) to determine morphological lung maturation and alterations in the pulmonary leukocyte content on dpp 7, 10, and 14. Daily LPS application did not change the lung volume but resulted in a significant retardation of alveolarization in both substrains proved by significantly lower values of septal surface and volume as well as higher mean free distances in airspaces. Looking at the immune status after LPS exposure compared to controls, a significantly higher percentage of B lymphocytes and decrease of CD4+CD25+ T cells were found in both subtypes, on dpp7 a significantly higher percentage of CD4 T+ cells in CD26+ pups, and a significantly higher percentage of monocytes in CD26− pups. The percentage of T cells was significantly higher in the CD26-deficient group on each dpp. Thus, daily postnatal exposition to low doses of LPS for 1 week resulted in a delay in formation of secondary septa, which remained up to dpp 14 in CD26− pups. The retardation was accompanied by moderate parenchymal inflammation and CD26-dependent changes in the pulmonary immune cell composition.

Differentiation of mouse fetal lung alveolar progenitors in serum-free organotypic cultures

Lung epithelial progenitors differentiate into alveolar type 1 (AT1) and type 2 (AT2) cells. These cells form the air-blood interface and secrete surfactant, respectively, and are essential for lung maturation and function. Current protocols to derive and culture alveolar cells do not faithfully recapitulate the architecture of the distal lung, which influences cell fate patterns in vivo. Here, we report serum-free conditions that allow for growth and differentiation of mouse distal lung epithelial progenitors. We find that Collagen I promotes the differentiation of flattened, polarized AT1 cells. Using these organoids, we performed a chemical screen to investigate WNT signaling in epithelial differentiation. We identify an association between Casein Kinase activity and maintenance of an AT2 expression signature; Casein Kinase inhibition leads to an increase in AT1/progenitor cell ratio. These organoids provide a simplified model of alveolar differentiation and constitute a scalable screening platform to identify and analyze cell differentiation mechanisms.

Human epididymis protein 4 and fetal lung maturity

Objectives To document the maternal and fetal cord blood levels of human epididymis protein 4 (HE-4) in term and preterm newborns in order to investigate the possible physiological role of HE-4 in fetal lung development. Methods This cross-sectional study was conducted in a university-affiliated hospital between April 2018 and September 2018. The study population consisted of cesarean section (C-section) deliveries after 24 weeks of pregnancy. Both maternal and umbilical cord HE-4 levels (mHE-4 and uHE-4, respectively) were measured using chemiluminescent microparticle immunoassay. Amniotic fluid was sampled from each case to determine the lamellar body count (LBC) as the gold standard test for lung maturation. All the parameters, including the uHE-4 levels, were compared between the term delivery (≥37 weeks) (n=52) and preterm delivery (24–37th weeks) (n=30) groups. The best cut-off value of uHE-4 was calculated for fetal lung maturity. Results There were no statistically significant differences between the groups regarding the demographic data. The mHE-4 levels did not statistically significantly differ between the groups (p>0.05) whereas the uHE-4 level of the preterm newborns was significantly higher than that of the term newborns (p<0.05). There was a significant negative association between the uHE-4 level and LBC (r=−0.389; p<0.001). The uHE-4 level was the only statistically significant fetal parameter indicating fetal lung maturity confirmed by LBC. At a cut-off value of 281 pmol/L, uHE-4 had 96.8% sensitivity, 45% specificity, 84.5% positive predictive value, and 81.8% negative predictive value for fetal lung maturity. Conclusions Although the exact physiological role of HE-4 has not yet been elucidated, this preliminary study supports the idea that HE-4 plays a role in fetal lung maturation to some extent.

The Effect of Betamethasone Dosing Interval on Perinatal Outcomes: 12 Hours or 24 Hours Apart

Objective Antenatal steroids are commonly used to stimulate fetal lung maturation, particularly in pregnancies at risk of early preterm labor. This study aimed to compare the effects of administering betamethasone at a 12- versus 24-hour interval on perinatal outcomes. Study Design This retrospective study included 423 early preterm births from 26+0/7 to 33+6/7 weeks of gestation. Patients received betamethasone at either a 12- or 24-hour dosing interval. Results When all patients in each group were evaluated together, there was no statistically significant difference between both groups for complications of prematurity, including respiratory distress syndrome (RDS). When the two groups were divided by gestational age (GA), the 32+0/7 to 33+6/7-week group that received betamethasone at a 24-hour interval had statistically lower 1- and 5-minute APGAR scores (p = 0.06 and p = 0.02, respectively). They also had a greater need for neonatal intensive care unit (NICU), NICU length of stay, RDS, and need for surfactant (p = 0.20, p = 0.09, p = 0.27, and p = 0.23, respectively) than did the infants at 32+0/7 to 33+6/7 weeks, who received betamethasone at a 12-hour interval. In the group with GA between 28+0/7 and 29+6/7 weeks, the 1-minute APGAR score was lower (p = 0.22), and the durations of hospital stay, and mechanical ventilation were longer (p = 0.048, p = 0.21, respectively) in the 24-hour interval group. No statistically significant difference was observed for all parameters in other GA groups. Conclusion A 12-hour dosing interval for betamethasone appears to be more appropriate, as it results in a reduction in some neonatal complications and provides a short dose interval. Key Points

Development and Functional Characterization of Fetal Lung Organoids

Preterm infants frequently suffer from pulmonary complications due to a physiological and structural lung immaturity resulting in significant morbidity and mortality. Novel in vitro and in vivo models are required to study the underlying mechanisms of late lung maturation and to facilitate the development of new therapeutic strategies. Organoids recapitulate essential aspects of structural organization and possibly organ function, and can be used to model developmental and disease processes. We aimed at generating fetal lung organoids (LOs) and to functionally characterize this in vitro model in comparison to primary lung epithelial cells and lung explants ex vivo. LOs were generated with alveolar and endothelial cells from fetal rat lung tissue, using a Matrigel-gradient and air-liquid-interface culture conditions. Immunocytochemical analysis showed that the LOs consisted of polarized epithelial cell adhesion molecule (EpCAM)-positive cells with the apical membrane compartment facing the organoid lumen. Expression of the alveolar type 2 cell marker, RT2-70, and the Club cell marker, CC-10, were observed. Na+ transporter and surfactant protein mRNA expression were detected in the LOs. First time patch clamp analyses demonstrated the presence of several ion channels with specific electrophysiological properties, comparable to vital lung slices. Furthermore, the responsiveness of LOs to glucocorticoids was demonstrated. Finally, maturation of LOs induced by mesenchymal stem cells confirmed the convenience of the model to test and establish novel therapeutic strategies. The results showed that fetal LOs replicate key biological lung functions essential for lung maturation and therefore constitute a suitable in vitro model system to study lung development and related diseases.