Ultrastructural Characterization of Genetic Diffuse Lung Diseases in Infants and Children: A Cohort Study and Review

Pediatric diffuse lung diseases are rare disorders with an onset in the neonatal period or in infancy, characterized by chronic respiratory symptoms and diffuse interstitial changes on imaging studies. Genetic disorders of surfactant homeostasis represent the main etiology. Surfactant protein B and ABCA3 deficiencies typically cause neonatal respiratory failure, which is often lethal within a few weeks or months. Although heterozygous ABCA3 mutation carriers are mostly asymptomatic, there is growing evidence that monoallelic mutations may affect surfactant homeostasis. Surfactant protein C mutations are dominant or sporadic disorders leading to a broad spectrum of manifestations from neonatal respiratory distress syndrome to adult pulmonary fibrosis. The authors performed pathology and ultrastructural studies in 12 infants who underwent clinical lung biopsy. One carried a heterozygous SP-B mutation, 3 carried SP-C mutations, and 7 carried ABCA3 mutations (5 biallelic and 2 monoallelic). Optical microscopy made it possible to distinguish between surfactant-related disorders and other forms. One of the ABCA3 monoallelic carriers had morphological features of alveolar capillary dysplasia, a genetic disorder of lung alveolar, and vascular development. One patient showed no surfactant-related anomalies but had pulmonary interstitial glycogenosis, a developmental disorder of unknown origin. Electron microscopy revealed specific lamellar bodies anomalies in all SP-B, SP-C, and ABCA3 deficiency cases. In addition, the authors showed that heterozygous ABCA3 mutation carriers have an intermediate ultrastructural phenotype between homozygous carriers and normal subjects. Lung biopsy is an essential diagnostic procedure in unexplained diffuse lung disorders, and electron microscopy should be performed systematically, since it may reveal specific alterations in genetic disorders of surfactant homeostasis

Congenital self-healing reticulohistiocytosis in a newborn: unusual oral and cutaneous manifestations

Abstract Background Congenital self-healing reticulohistiocytosis (CSHRH), also called Hashimoto-Pritzker disease, is a rare and benign variant of Langerhans cell histiocytosis, characterized by cutaneous lesions without extracutaneous involvement. Case presentation We present a case of CSHRH with diffuse skin lesions and erosions in the oral mucosa, present since birth and lasting for 2 months, and we perform a review of the literature on Pubmed in the last 10 years. Conclusions Our case confirm that lesions on oral mucosa, actually underestimated, may be present in patients with CSHRH. Patients affected by CSHRH require a close follow-up until the first years of life, due to the unpredictable course of Langerhans cell histiocytosis, in order to avoid missing diagnosis of more aggressive types of this disorder

Nasal high-frequency oscillatory ventilation and CO2 removal: A randomized controlled crossover trial

Objective: To compare short-term application of nasal high-frequency oscillatory ventilation (nHFOV) with nasal continuous positive airway pressure (nCPAP). Working Hypothesis: nHFOV improves CO2 removal with respect to nCPAP in preterm infants needing noninvasive respiratory support and persistent oxygen supply after the first 72 h of life. Study Design: Multicenter non-blinded prospective randomized crossover study. Patient Selection: Thirty premature infants from eight tertiary neonatal intensive care units, of mean \ub1 SD 26.4 \ub1 1.8 weeks of gestational age and 921 \ub1 177 g of birth weight. Methodology: Infants were randomly allocated in a 1:1 ratio to receive a starting treatment mode of either nCPAP or nHFOV delivered by the ventilator CNO (Medin, Germany), using short binasal prongs of appropriate size. A crossover design with four 1-h treatment periods was used, such that each infant received both treatments twice. The primary outcome was the mean transcutaneous partial pressure of CO2 (TcCO2) value during the 2-h cumulative period of nHFOV compared with the 2-h cumulative period of nCPAP. Results: Significantly lower TcCO2 values were observed during nHFOV compared with nCPAP: 47.5 \ub1 7.6 versus 49.9 \ub1 7.2 mmHg, respectively, P = 0.0007. A different TcCO2 behavior was found according to the random sequence: in patients starting on nCPAP, TcCO2 significantly decreased from 50.0 \ub1 8.0 to 46.6 \ub1 7.5 mmHg during nHFOV (P = 0.001). In patients starting on nHFOV, TcCO2 slightly increased from 48.5 \ub1 7.8 to 49.9 \ub1 6.7 mmHg during nCPAP (P = 0.13). Conclusions: nHFOV delivered through nasal prongs is more effective than nCPAP in improving the elimination of CO2

Phenotype characterisation of mutation and deletion carriers with neonatal and paediatric pulmonary hypertension.

Rare variants in the T-box transcription factor 4 gene () have recently been recognised as an emerging cause of paediatric pulmonary hypertension (PH). Their pathophysiology and contribution to persistent pulmonary hypertension in neonates (PPHN) are unknown. We sought to define the spectrum of clinical manifestations and histopathology associated with variants in neonates and children with PH.We assessed clinical data and lung tissue in 19 children with PH, including PPHN, carrying rare variants identified by next-generation sequencing and copy number variation arrays.Variants included six 17q23 deletions encompassing the entire locus and neighbouring genes, and 12 likely damaging mutations. 10 infants presented with neonatal hypoxic respiratory failure and PPHN, and were subsequently discharged home. PH was diagnosed later in infancy or childhood. Three children died and two required lung transplantation. Associated anomalies included patent ductus arteriosus, septal defects, foot anomalies and developmental disability, the latter with a higher prevalence in deletion carriers. Histology in seven infants showed abnormal distal lung development and pulmonary hypertensive remodelling. mutations and 17q23 deletions underlie a new form of developmental lung disease manifesting with severe, often biphasic PH at birth and/or later in infancy and childhood, often associated with skeletal anomalies, cardiac defects, neurodevelopmental disability and other anomalies

Timing of Symptoms of Early-Onset Sepsis after Intrapartum Antibiotic Prophylaxis: Can It Inform the Neonatal Management?

The effectiveness of “inadequate” intrapartum antibiotic prophylaxis (IAP administered E. coli culture-confirmed EOS cases. IAP was defined “active” when the pathogen yielded in cultures was susceptible. We identified 263 EOS cases (GBS = 191; E. coli = 72). Among GBS EOS, 25% had received IAP (always active when beta-lactams were administered). Most IAP-exposed neonates with GBS were symptomatic at birth (67%) or remained asymptomatic (25%), regardless of IAP duration. Among E. coli EOS, 60% were IAP-exposed. However, IAP was active in only 8% of cases, and these newborns remained asymptomatic or presented with symptoms prior to 6 h of life. In contrast, most newborns exposed to an “inactive” IAP (52%) developed symptoms from 1 to >48 h of life. The key element to define IAP “adequate” seems the pathogen’s antimicrobial susceptibility rather than its duration. Newborns exposed to an active antimicrobial (as frequently occurs with GBS infections), who remain asymptomatic in the first 6 h of life, are likely uninfected. Because E. coli isolates are often unsusceptible to beta-lactam antibiotics, IAP-exposed neonates frequently develop symptoms of EOS after birth, up to 48 h of life and beyond

Age-dependent Accumulation of Soluble Amyloid β (Aβ) Oligomers Reverses the Neuroprotective Effect of Soluble Amyloid Precursor Protein-α (sAPPα) by Modulating Phosphatidylinositol 3-Kinase (PI3K)/Akt-GSK-3β Pathway in Alzheimer Mouse Model*

Neurotrophins, activating the PI3K/Akt signaling pathway, control neuronal survival and plasticity. Alterations in NGF, BDNF, IGF-1, or insulin signaling are implicated in the pathogenesis of Alzheimer disease. We have previously characterized a bigenic PS1×APP transgenic mouse displaying early hippocampal Aβ deposition (3 to 4 months) but late (17 to 18 months) neurodegeneration of pyramidal cells, paralleled to the accumulation of soluble Aβ oligomers. We hypothesized that PI3K/Akt/GSK-3β signaling pathway could be involved in this apparent age-dependent neuroprotective/neurodegenerative status. In fact, our data demonstrated that, as compared with age-matched nontransgenic controls, the Ser-9 phosphorylation of GSK-3β was increased in the 6-month PS1×APP hippocampus, whereas in aged PS1×APP animals (18 months), GSK-3β phosphorylation levels displayed a marked decrease. Using N2a and primary neuronal cell cultures, we demonstrated that soluble amyloid precursor protein-α (sAPPα), the predominant APP-derived fragment in young PS1×APP mice, acting through IGF-1 and/or insulin receptors, activated the PI3K/Akt pathway, phosphorylated the GSK-3β activity, and in consequence, exerted a neuroprotective action. On the contrary, several oligomeric Aβ forms, present in the soluble fractions of aged PS1×APP mice, inhibited the induced phosphorylation of Akt/GSK-3β and decreased the neuronal survival. Furthermore, synthetic Aβ oligomers blocked the effect mediated by different neurotrophins (NGF, BDNF, insulin, and IGF-1) and sAPPα, displaying high selectivity for NGF. In conclusion, the age-dependent appearance of APP-derived soluble factors modulated the PI3K/Akt/GSK-3β signaling pathway through the major neurotrophin receptors. sAPPα stimulated and Aβ oligomers blocked the prosurvival signaling. Our data might provide insights into the selective vulnerability of specific neuronal groups in Alzheimer disease