1,721,038 research outputs found
Alveolar surfactant phosphatidylglycerol, disaturated phosphatidylcholine, and SP-B kinetics in infants and adults with stable isotopes tracers, and H+V-ATPase activity in B1 subunit knockout mice
Full text linkAlveolar surfactant is the key physiological structure that every mammal utilizes to live while breathing air. It is a mixture of proteins and lipids that lines the external part of the alveoli and allows a water-based organism to use air as source of oxygen. Disorders in surfactant’s metabolism are known to be involved in life-threatening diseases like the acute respiratory distress syndrome and cystic fibrosis. In this thesis we describe the kinetics of two main surfactant’s phospholipids (phosphatidylglycerol and disaturated-phosphatidylcholine) and of its specific protein B, in vivo in humans, all obtained with stable isotopes infusion protocols in children (phospholipids) and adults (protein SP-B). In the last part we tried to use the model of renal intercalated cells to approach the role of pH in the secretion of surfactant.Il surfattante alveolare è la struttura fisiologica che viene utilizzata da ogni mammifero per vivere e respirare in atmosfera. Si tratta di un complesso di proteine e lipidi che si trova nella parte esterna degli alveoli, dove svolge la sua funzione fisiologica permettendo lo scambio gassoso tra organismo (principalmente acquoso) e aria. Alterazioni del metabolismo del surfattante sono note in numerose e gravi malattie, come la sindrome da distress respiratorio e la fibrosi cistica. In questa tesi sono descritte le cinetiche di due principali fosfolipidi (fosfatidilglicerolo e fosfatidilcolina disatura) e di una proteina specifica del surfattante (SP-B), misurati in vivo nell’uomo attraverso l’infusione di isotopi stabili. Nell’ultima parte è descritto il tentativo di utilizzare il modello delle cellule intercalate del rene per studiare il ruolo delle variazioni di pH nella secrezione del surfattante
White matter injury and neurodevelopmental disabilities: A cross-disease (dis)connection
Full text linkProspective assessment of early developmental markers and their association with neuropsychological impairment
Full text linkChildren who experience adversities in the pre-perinatal period are at increased risk of developing impairment later in life, despite the absence of overt brain and neurological abnormalities. However, many of these children exhibit sequelae several years after a period of normal appearance. As a result, the need for reliable developmental assessments for the early detection of infants at high risk of adverse neurodevelopmental outcomes has emerged. The Griffiths Mental Developmental Scales have a promising but poorly explored prognostic ability. This longitudinal study evaluated the predictive power of the Griffiths Mental Developmental Scales at 12 and 24 months on the cognitive and neuropsychological profile at 6 years of age in a sample of 70 children with a history of prematurity or perinatal asphyxia but without brain and neurological abnormalities. We found that the Griffiths Mental Developmental Scales at 24 months had good predictive ability on the intelligence quotient at 6 years and the capacity to predict some neuropsychological performances. On the other hand, the Griffiths Mental Developmental Scale at 12 months was not associated with the performance at 6 years or 24 months. Conclusion: Data on brain development converge to indicate that the first two years of age represent a critical stage of development, particularly for children experiencing mild pre-perinatal adversities who are thought to exhibit white matter dysmaturity. For this reason, this age is crucial for identifying which children are at major risk, leaving enough time to intervene before overt deficits become apparent. Brain development in the first 2 years could explain the limited reliability of early neurodevelopmental testing.What is Known:& BULL; Pre-perinatal adversities increase the risk of developing neurodevelopmental disorders.& BULL; The predictive ability of the Griffith scale is poorly explored in low-grade conditions.What is New:& BULL; The predictive ability of the Griffith scale has been investigated in low-risk children.& BULL; A complete neuropsychological profile could offer a more accurate prediction than the intellectual quotient
Neonatal Respiratory Diseases in the Newborn Infant: Novel Insights from Stable Isotope Tracer Studies
No full textRespiratory distress syndrome is a common problem in preterm infants and the etiology is multifactorial. Lung underdevelopment, lung hypoplasia, abnormal lung water metabolism, inflammation, and pulmonary surfactant deficiency or disfunction play a variable role in the pathogenesis of respiratory distress syndrome. High-quality exogenous surfactant replacement studies and studies on surfactant metabolism are available; however, the contribution of surfactant deficiency, alteration or dysfunction in selected neonatal lung conditions is not fully understood. In this article, we describe a series of studies made by applying stable isotope tracers to the study of surfactant metabolism and lung water. In a first set of studies, which we call 'endogenous studies', using stable isotope-labelled intravenous surfactant precursors, we showed the feasibility of measuring surfactant synthesis and kinetics in infants using several metabolic precursors including plasma glucose, plasma fatty acids and body water. In a second set of studies, named 'exogenous studies', using stable isotope-labelled phosphatidylcholine tracer given endotracheally, we could estimate surfactant disaturated phosphatidylcholine pool size and half-life. Very recent studies are focusing on lung water and on the endogenous biosynthesis of the surfactant-specific proteins. Information obtained from these studies in infants will help to better tailor exogenous surfactant treatment in neonatal lung diseases
Alternative techniques of right ventricular outflow tract reconstruction for surgical repair of truncus arteriosus
No full textOBJECTIVES: This study aimed to evaluate the outcomes and feasibility of different techniques of reconstruction of the right ventricular outflow tract (RVOT) in surgical repair of truncus arteriosus. METHODS: We retrospectively reviewed all consecutive patients with truncus arteriosus who underwent successful surgical repair in our centre between 1994 and 2017. We analysed late results according to the type of RVOT repair. RESULTS: We collected data from 29 survivors after truncus arteriosus repair. Six (20%) of them were affected by DiGeorge syndrome. The RVOT reconstruction was achieved using a valved conduit in 58.6%, while a direct right ventricle-pulmonary artery (RV-PA) anastomosis, with or without the interposition of the left atrial appendage, was performed in the remaining. At a median follow-up time of 7.9 years (interquartile range 1.8-13.1), 6 patients (3 affected by DiGeorge syndrome) died. Between the 2 groups, there were no differences in terms of the late mortality and onset of adverse events. However, the use of a conduit seemed more prone to reintervention and onset of adverse events. CONCLUSIONS: Different RVOT reconstruction techniques are safe and have similar late outcomes. However, use of a direct RV-PA anastomosis and left atrial appendage interposition may reduce the need for reoperation in the long term
Social Skills and Psychopathology are associated with Autonomic Function in children: a full robust Bayesian approach for a small sample size, data rich study
Full text linkLong-term experience with the one-and-a-half ventricle repair for simple and complex congenital heart defects
No full textThe one-and-a-half ventricle repair (1.5VR) is a surgical alternative to Fontan circulation or high-risk biventricular repair in patients with complex congenital heart disease (CHD) with a hypoplastic right ventricle (RV). We report our 25 years of experience to evaluate whether the degree of anatomical complexity of the CHD can affect long-term outcomes
Neonatal spectral EEG is prognostic of cognitive abilities at school age in premature infants without overt brain damage
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