This study investigated the relationship between three respiratory support approaches on lung volume recruitment during the first 2 h of postnatal life in preterm lambs. We estimated changes in lung aeration, measuring respiratory resistance and reactance by oscillometry at 5 Hz. We also measured intratracheal pressure in subsets of lambs.
View Article and Find Full Text PDFAm J Physiol Lung Cell Mol Physiol
June 2024
Novel therapies are needed for bronchopulmonary dysplasia (BPD) because no effective treatment exists. Mesenchymal stromal cell extracellular vesicles (MSC-sEVs) have therapeutic efficacy in a mouse pup neonatal hyperoxia BPD model. We tested the hypothesis that MSC-sEVs will improve lung functional and structural development in mechanically ventilated preterm lambs.
View Article and Find Full Text PDFBackground: Nucleated red blood cells (NRBC) are very uncommon in the blood of children and adults, but small numbers are not rare in neonates on the day of birth. Elevated NRBC counts in neonates can be seen following erythropoietin dosing. Limited studies in human neonates suggest the time-interval between erythropoietin dosing and the first appearance of NRBC in the blood (the "NRBC emergence-time") is in excess of 24 hours.
View Article and Find Full Text PDFBackground: Low levels of insulin-like growth factor-1 (IGF-1) protein in preterm human infants are associated with bronchopulmonary dysplasia (BPD). We used our preterm lamb model of BPD to determine (1) dosage of recombinant human (rh) IGF-1 bound to binding protein-3 (IGFBP-3) to reach infant physiologic plasma levels; and (2) whether repletion of plasma IGF-1 improves pulmonary and cardiovascular outcomes.
Methods: Group 1: normal, unventilated lambs from 128 days gestation through postnatal age 5 months defined normal plasma levels of IGF-1.
Sustaining impactful research within the field of perinatal biology requires training and retention of the next generations of physician-scientists and basic-scientists. Professional societies such as the Perinatal Research Society (PRS) have a unique role to play in training and retention of perinatal biologists. Here we report outcomes for an innovative Young Investigator Training Workshop created for the PRS.
View Article and Find Full Text PDFRecent clinical studies have shown that traumatic brain injury is a significant risk factor for stroke. Motivated to better understand possible mechanisms of this association, we studied subfailure disruption of the intima in overstretched sheep cerebral arteries, as this has been implicated in the increased risk of stroke following blunt cerebrovascular injury. Middle cerebral arteries from four age groups (ranging from fetal to adult) were stretched axially to failure, and intimal disruption was captured with a video camera.
View Article and Find Full Text PDFBackground: Adults born preterm (< 37 weeks' gestation) exhibit altered cardiac growth and are susceptible to cardiac dysfunction. Sheep studies have shown that moderate preterm birth results in maladaptive structural remodelling of the cardiac ventricles. The aim of this study was to examine ventricular structure in lambs born at a greater severity of preterm birth and ventilated postnatally.
View Article and Find Full Text PDFInvasive mechanical ventilation (IMV) and exposure to oxygen-rich gas during early postnatal life are contributing factors for long-term pulmonary morbidities faced by survivors of preterm birth and bronchopulmonary dysplasia. The duration of IMV that leads to long-term pulmonary morbidities is unknown. We compared two durations of IMV (3 h vs.
View Article and Find Full Text PDFBackground: The brain of chronically ventilated preterm human infants is vulnerable to collateral damage during invasive mechanical ventilation (IMV). Damage is manifest, in part, by learning and memory impairments, which are hippocampal functions. A molecular regulator of hippocampal development is insulin-like growth factor 1 (IGF1).
View Article and Find Full Text PDFPulmonary angiogenesis is a key driver of alveolarization. Our prior studies showed that NF-κB promotes pulmonary angiogenesis during early alveolarization. However, the mechanisms regulating temporal-specific NF-κB activation in the pulmonary vasculature are unknown.
View Article and Find Full Text PDFDiffusion tensor imaging (DTI) is an MRI technique that can be used to map cardiomyocyte tracts and estimate local cardiomyocyte and sheetlet orientation within the heart. DTI measures diffusion distances of water molecules within the myocardium, where water diffusion generally occurs more freely along the long axis of cardiomyocytes and within the extracellular matrix, but is restricted by cell membranes such that transverse diffusion is limited. DTI can be undertaken in fixed hearts and it allows the three-dimensional mapping of the cardiac microarchitecture, including cardiomyocyte organization, within the whole heart.
View Article and Find Full Text PDFResearch within the anatomical sciences often relies on human cadaveric tissues. Without the good will of these donors who allow us to use their bodies to push forward our anatomical knowledge, most human anatomical research would come to a standstill. However, many research papers omit an acknowledgement to the donor cadavers or, as no current standardized versions exist, use language that is extremely varied.
View Article and Find Full Text PDFBackground: Dysregulated nitric oxide (NO) signaling contributes to chronic hypoxia (CH)-induced pulmonary hypertension (PH). NO signaling is improved and pulmonary vascular resistance (PVR) is reduced in CH piglets treated with the l-arginine-NO precursor, l-citrulline. We hypothesized that l-citrulline might cause structural changes in the pulmonary circulation that would contribute to the reduction in PVR and that the l-citrulline-induced structural changes would be accompanied by alterations in vascular endothelial growth factor (VEGF) signaling.
View Article and Find Full Text PDFA group of original papers is assembled for this thematic-papers issue on traditional Chinese medicine (TCM). The idea for a thematic-papers issue came from Associate Editor and Guest Editor, Jicheng Li. Jicheng's idea was to introduce concepts and studies of TCM to the editorial board of The Anatomical Record and the Journal's readership.
View Article and Find Full Text PDFObjectives: To assess the National Institute of Child Health and Human Development's Pediatric Critical Care Trauma Scientist Development Program national K12 program.
Design: Mixed-methods study.
Setting: Pediatric Critical Care Trauma Scientist Development Program participants from 2005 to 2018.