Lisa Giovannini-Chami

Control of vertebrate multiciliogenesis by miR-449 through direct repression of the Delta/Notch pathway

Multiciliated cells lining the surface of some vertebrate epithelia are essential for various physiological processes, such as airway cleansing. However, the mechanisms governing motile cilia biosynthesis remain poorly elucidated. We identify miR-449 microRNAs as evolutionarily conserved key regulators of vertebrate multiciliogenesis. In human airway epithelium and Xenopus laevis embryonic epidermis, miR-449 microRNAs strongly accumulated in multiciliated cells. In both models, we show that miR-449 microRNAs promote centriole multiplication and multiciliogenesis by directly repressing the Delta/Notch pathway. We established Notch1 and its ligand Delta-like 1(DLL1) as miR-449 bona fide targets. Human DLL1 and NOTCH1 protein levels were lower in multiciliated cells than in surrounding cells, decreased after miR-449 overexpression and increased after miR-449 inhibition. In frog, miR-449 silencing led to increased Dll1 expression. Consistently, overexpression of Dll1 mRNA lacking miR-449 target sites repressed multiciliogenesis, whereas both Dll1 and Notch1 knockdown rescued multiciliogenesis in miR-449-deficient cells. Antisense-mediated protection of miR-449-binding sites of endogenous human Notch1 or frog Dll1 strongly repressed multiciliogenesis. Our results unravel a conserved mechanism whereby Notch signalling must undergo miR-449-mediated inhibition to permit differentiation of ciliated cell progenitors.

Distinct epithelial gene expression phenotypes in childhood respiratory allergy.

Epithelial cell contribution to the natural history of childhood allergic respiratory disease remains poorly understood. Our aims were to identify epithelial pathways that are dysregulated in different phenotypes of respiratory allergy. We established gene expression signatures of nasal brushings from children with dust mite-allergic rhinitis, associated or not associated with controlled or uncontrolled asthma. Supervised learning and unsupervised clustering were used to predict the different subgroups of patients and define altered signalling pathways. These profiles were compared with those of primary cultures of human nasal epithelial cells stimulated with either interleukin (IL)-4, IL-13, interferon (IFN)-&agr;, IFN-&bgr; or IFN-&ggr;, or during in vitro differentiation. A supervised method discriminated children with allergic rhinitis from healthy controls (prediction accuracy 91%), based on 61 transcripts, including 21 T-helper cell (Th) type 2-responsive genes. This method was then applied to predict children with controlled or uncontrolled asthma (prediction accuracy 75%), based on 41 transcripts: nine of them, which were down-regulated in uncontrolled asthma, are directly linked to IFN. This group also included GSDML, which is genetically associated with asthma. Our data revealed a Th2-driven epithelial phenotype common to all children with dust mite allergic rhinitis. It highlights the influence of epithelially expressed molecules on the control of asthma, in association with atopy and impaired viral response.

Sleep disordered breathing in patients with Prader–Willi syndrome: A multicenter study

Sleep disordered breathing (SDB) is common in patients with Prader–Willi syndrome (PWS) and systematic screening is recommended, especially before growth hormone treatment. The aim of the study was to describe the baseline SDB and therapeutic interventions in a large cohort of patients.

Immediate contact urticaria caused by hydrolysed wheat proteins in a child via maternal skin contact sensitization.

Conflicts of interest: The authors have declared no conflicts. device (Stallergenes , Antony, France), and commercially prepared extracts (Stallergenes ), moisturizing cream (Yves Rocher , La Gacilly, France) and its 26 components provided by the manufacturer (Yves Rocher ). Control tests for prick tests were performed with histamine (positive control) and normal saline (negative control). Wheal diameters were measured 15 min after the skin test was applied, and were reported as mean wheal diameter. A prick test wheal diameter at least 3 mm larger than the negative control was considered to be positive. Multiple sensitization to mustard (6 mm), pistachios (23 mm), cashew (15 mm), chestnut (6 mm) and pine nuts (6 mm) was found. A positive response was observed with the moisturizing cream (11 mm), and positive responses were also observed with the macadamia nuts (6 mm) and the commercial hydrolysed wheat protein (4 mm), which were listed in the cream’s composition. Secondary prick tests with 26 components of the cream confirmed the responsibility of hydrolysed wheat

Eosinophilic pneumonias in children: A review of the epidemiology, diagnosis, and treatment.

Pediatric eosinophilic pneumonias (EPs) are characterized by a significant infiltration of the alveolar spaces and lung interstitium by eosinophils, with conservation of the lung structure. In developed countries, EPs constitute exceptional entities in pediatric care. Clinical symptoms may be transient (Löffler syndrome), acute (<1 month and mostly <7 days), or chronic (>1 month). Diagnosis relies on demonstration of alveolar eosinophilia on bronchoalveolar lavage, whether or not associated with blood eosinophilia. EPs are a heterogeneous group of disorders divided into: (i) secondary forms (seen mainly in parasitic infections, allergic bronchopulmonary aspergillosis, and drug reactions); and (ii) primary forms (eosinophilic granulomatosis with polyangiitis, hypereosinophilic syndrome, idiopathic chronic eosinophilic pneumonia, and idiopathic acute eosinophilic pneumonia). Despite their rarity, the etiological approach to EP must be well‐defined as some causes can be rapidly life‐threatening without initiation of the proper treatment. This approach (i) eliminates secondary forms, with comprehensive history taking and minimal biological assessment, (ii) is oriented in primary forms by the acute or chronic setting, and the existence of extrapulmonary symptoms. Treatment of primary forms has traditionally relied on corticosteroids, usually with a dramatic response. Specific treatments or the adjunction of corticosteroid‐sparing treatment or immunosuppressors are currently being evaluated in order to improve the prognosis and the side effects associated with corticosteroid treatment in a pediatric setting. Pediatr Pulmonol. 2016;51:203–216.

Idiopathic eosinophilic pneumonia in children: the French experience

BackgroundIdiopathic eosinophilic pneumonia is extremely rare in children and adults. We present herein the first series describing the specificities of idiopathic chronic (ICEP) and acute (IAEP) eosinophilic pneumonia in children.MethodsWe retrospectively analyzed all cases of ICEP and IAEP in children that were retrieved from French Reference Centers for rare pediatric lung diseases.ResultsFive cases of pediatric ICEP were identified. Corticosteroid or immunosuppressive therapy dramatically improved the outcome in three cases. The remaining two cases had a persistent interstitial pattern with progressive development of cystic airspace lesions. Three cases of IAEP in adolescents were reported, with one requiring four days of extracorporeal membrane oxygenation.ConclusionICEP is a rare disease with a polymorphic clinical presentation in children. We identified patients with persistent interstitial patterns progressing to cystic airspace regions, for which the boundaries with idiopathic interstitial pneumonias are difficult to establish. We therefore propose a specific pediatric definition and classification algorithm. IAEP in children remains an inflammatory reaction of the lung to an acute toxic exposure, mainly tobacco, as in adults. International studies are required to comprehensively assess the various clinical forms of the disease as well as the appropriate therapeutic regimens.

Evaluation of the Bladder Stimulation Technique to Collect Midstream Urine in Infants in a Pediatric Emergency Department

Objective Midstream clean-catch urine is an accepted method to diagnose urinary tract infection but is impracticable in infants before potty training. We tested the bladder stimulation technique to obtain a clean-catch urine sample in infants. Materials and methods We included 142 infants under walking age who required a urine sample in a cross- sectional study carried out during a 3-months period, from September to November 2014, in the emergency department of the University Children’s Hospital of Nice (France). A technique based on bladder stimulation and lumbar stimulation maneuvers, with at least two attempts, was tested by four trained physicians. The success rate and time to obtain urine sample within 3 minutes were evaluated. Discomfort (EVENDOL score ≥4/15) was measured. We estimated the risk factors in the failure of the technique. Chi-square test or Fisher’s exact test were used to compare frequencies. T-test and Wilcoxon test were used to compare quantitative data according to the normality of the distribution. Risk factors for failure of the technique were evaluated using a multivariate logistic regression model. Results We obtained midstream clean-catch urine in 55.6% of infants with a median time of 52.0 s (10.0; 110.0). The success rate decreased with age from 88.9% (newborn) to 28.6% (>1 y) (p = 0.0001) and with weight, from 85.7% (<4kg) to 28.6% (>10kg) (p = 0.0004). The success rate was 60.8% for infants without discomfort (p<0.0001). Heavy weight and discomfort were associated with failure, with adjusted ORs of 1.47 [1.04–2.31] and 6.65 [2.85–15.54], respectively. Conclusion Bladder stimulation seems to be efficient in obtaining midstream urine with a moderate success rate in our study sample. This could be an alternative technique for infants before potty training but further randomized multicenter studies are needed to validate this procedure.

Work of breathing to optimize noninvasive ventilation in bronchiolitis obliterans

Dear Editor, Bronchiolitis obliterans (BO) is a rare form of chronic obstructive pulmonary disease secondary to an insult to the terminal airway, resulting in a narrowing and/or complete obliteration of the small airways [1]. We report here the results of analysis of the work of breathing and respiratory mechanics in an infant with severe BO after respiratory syncytial (RSV) infection [2] and show its usefulness to optimize noninvasive positive pressure ventilation (NPPV). E.H. was a 28-month-old premature boy (35 weeks gestational age, 2,260 g), 10 kg weight who presented mild respiratory distress at birth. He was re-admitted at day 24 of life for severe RSV bronchiolitis with respiratory failure persisting after 11 days of invasive ventilation. Because of persistent daytime hypercapnia (PaCO2 *70 mmHg with levels up to 123 mmHg during exacerbations) despite medical treatment with methylprednisolone pulses, he was started on NPPV at 1 year of age. PaCO2 fell to 55 mmHg during NPPV but remained at 73 mmHg during spontaneous breathing with oxygen. The change of the ventilator VPAP IV ST (Resmed) for the Trilogy 100 (Philips Respironics, Carquefou, France) with the AVAPS mode [inspiratory pressure (IPAP) 10–13 cmH2O, expiratory pressure (EPAP) 4 cmH2O, tidal volume (VT) 120 ml, inspiratory flow trigger most sensitive (1 L/min), expiratory flow trigger at 60% of maximal inspiratory flow] with a single circuit and a nasal mask with a manufacturer leak (MiniMe mask; SleepNet Corp., New Hampshire, USA) was not associated with an improvement in gas exchange and clinical status. He was therefore referred to our unit to optimize NPPV. During spontaneous breathing, oesophageal (Poes) and transdiaphragmatic pressure (Pdi) swings were increased sevento eight-fold (*40 cmH2O, normal *5 cmH2O), inspiratory time (Ti) exceeded the expiratory time (Te) (Ti/Ttot 0.60), and expiration was active [positive gastric pressure (Pgas) swing during expiration], with an intrinsic positive end-expiratory pressure (PEEPi 14 and 17 cmH2O) (Fig. 1).

Impact of MicroRNA in Normal and Pathological Respiratory Epithelia

Extensive sequencing efforts, combined with ad hoc bioinformatics developments, have now led to the identification of 1222 distinct miRNAs in human (derived from 1368 distinct genomic loci) and of many miRNAs in other multicellular organisms. The present chapter is aimed at describing a general experimental strategy to identify specific miRNA expression profiles and to highlight the functional networks operating between them and their mRNA targets, including several miRNAs deregulated in cystic fibrosis and during differentiation of airway epithelial cells.

Development of Reliable and Validated Tools to Evaluate Technical Resuscitation Skills in a Pediatric Simulation Setting: Resuscitation and Emergency Simulation Checklist for Assessment in Pediatrics

Objectives To develop a reliable and validated tool to evaluate technical resuscitation skills in a pediatric simulation setting. Study design Four Resuscitation and Emergency Simulation Checklist for Assessment in Pediatrics (RESCAPE) evaluation tools were created, following international guidelines: intraosseous needle insertion, bag mask ventilation, endotracheal intubation, and cardiac massage. We applied a modified Delphi methodology evaluation to binary rating items. Reliability was assessed comparing the ratings of 2 observers (1 in real time and 1 after a video‐recorded review). The tools were assessed for content, construct, and criterion validity, and for sensitivity to change. Results Inter‐rater reliability, evaluated with Cohen kappa coefficients, was perfect or near‐perfect (>0.8) for 92.5% of items and each Cronbach alpha coefficient was ≥0.91. Principal component analyses showed that all 4 tools were unidimensional. Significant increases in median scores with increasing levels of medical expertise were demonstrated for RESCAPE‐intraosseous needle insertion (P = .0002), RESCAPE‐bag mask ventilation (P = .0002), RESCAPE‐endotracheal intubation (P = .0001), and RESCAPE‐cardiac massage (P = .0037). Significantly increased median scores over time were also demonstrated during a simulation‐based educational program. Conclusions RESCAPE tools are reliable and validated tools for the evaluation of technical resuscitation skills in pediatric settings during simulation‐based educational programs. They might also be used for medical practice performance evaluations.