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Biomedical subjects

C Delacourt

Publications and source records attributed to C Delacourt.

At least 19 recordsLinked to original sources

[Inflammation and cystic fibrosis].

Lung inflammation plays a pivotal role in the pathogenesis of airway disease in cystic fibrosis (CF). Inflammation occurs very early and can be identified in very young infants. Inflammatory response is also more intense in CF than in non-CF airway inflammatory diseases. Among the different cell types involved in the airway inflammation, neutrophils are recognized to play a central role by releasing proinflammatory mediators, such as reactive oxygen species and proteolytic enzymes. Whether inflammation arises independently from infection remains debated. While infection was demonstrated to clearly amplify the inflammation, several studies argue for the possibility of an intrinsic inflammation. Finally, there is also evidence that the severity of pulmonary disease is linked to other genetic factors outside the CFTR gene locus, involved in host defence and inflammation.

Cystic Fibrosis↗

Comparison of the efficacy and safety of nebulized beclometasone dipropionate and budesonide in severe persistent childhood asthma.

Inhaled steroids are recommended for long-term control of asthma, but their use may be limited in young children because of difficulties in using the associated inhaler device. The use of nebulizers may help to overcome this issue, without compromising therapeutic efficacy or safety. This 14-week, multicentre, randomized, controlled, open-label, parallel-group study compared the efficacy and safety of nebulized corticosteroids in paediatric patients (aged 6 months to 6 years) with severe persistent asthma. Beclometasone dipropionate (BDP) 800 microgday(-1) suspension for nebulization and budesonide (BUD) 750 microg day(-1) given by nebulization in a twice-daily regimen, and when used in addition to the usual maintenance therapy, resulted in comparable clinical efficacy across all parameters. The primary efficacy endpoint was the number of patients who did not experience any major exacerbation, this being 40.4% and 51.7% in the BDP and BUD groups respectively in the ITT population (P = 0.28), and the mean number of global exacerbations (major plus minor) decreased respectively by -37.5% in the BDP group and -23.3% in the BUD group. Both treatments were also associated with marked reductions in the number of nights with wheezing and the number of days of oral steroid use. Moreover, the two treatment groups had a similar adverse-event incidence and profile. Only 11 adverse events were reported, and no serious adverse events were related to treatment. Urinary cortisol and the time course of height and weight were unaffected by both treatments, and BDP was confirmed to have a neutral effect on bone metabolism. In conclusion, this study demonstrates that both BDP 800 microg day(-1) suspension for nebulization and BUD 750 microgday(-1) administered by nebulization are effective, with an acceptable safety profile, for treatment of severe persistent asthma in infants and young children.

Administration, Inhalation↗

[Normal and abnormal alveolar development].

INTRODUCTION: Alveolar growth predominantly occurs post-natally and is characterised by the multiplication of alveoli, the thinning of inter-alveolar walls, and the maturation of capillary vessels. STATE OF THE ART: Alveolar growth is controlled by numerous factors whose interactions remain poorly understood. Many phenomena can interfere with normal alveolar growth resulting in abnormal development and a reduction in alveolar surface. This is especially the case in premature human neonates, whose lungs are structurally and functionally immature. Oxygen therapy, mechanical ventilation, and airway inflammation may induce alveolar growth disorders in these children, resulting in the development of bronchopulmonary dysplasia. PERSPECTIVES AND CONCLUSIONS: Further studies are needed to improve our knowledge about alveolar growth regulatory mechanisms so that better strategies can be developed to prevent these respiratory complications in premature neonates.

Bronchopulmonary Dysplasia↗

[Detection of exercise-induced bronchospasm in sixth-grade students: impact of health education].

UNLABELLED: Underdiagnosis of asthma is frequent in children and may be improved by the development of school-based health programs. MATERIAL AND METHODS: We developed an educational program in 11-year-old schoolchildren who participated in a screening test for exercise-induced asthma (EIA). All children were given an asthma questionnaire before and after two educational sessions. RESULTS: Mean score for asthma knowledge quiz increased from 63 to 85% (p < 0.001). Thirty-six children (3.7%) were initially considered as asthmatic and showed better responses than non-asthmatic children. Peak expiratory flow (PEF) was measured before and after an outside running exercise. A fall in PEF of at least 15% was considered an abnormal result. Seventy-height children (8%) had a decrease in PEF, including 65 children initially not recognized as asthmatic. For these latter, a medical evaluation was recommended to parents. Only 28 of these children gave informations on follow-up: 19 had lung function tests, two received a treatment without preliminary function test, and seven had neither lung function test nor treatment. Among the children who realized lung function tests, five had criteria for airway obstruction at baseline, and ten had significant bronchial hyperreactivity. CONCLUSIONS: However, a new screening test revealed that only a small minority of children initially not recognized as asthmatic but having decreased their PEF, were consequently considered as asthmatic by their practitioner, even in case of positive lung function test.

Adolescent↗

[From bronchiolitis to asthma].

Relationships between lower respiratory diseases with wheezing during infancy and asthma at school-age remain debatted. Indeed, although epidemiologic studies show that wheezy infants most often become asymptomatic before entry to school, they also demonstrate that severe bronchiolitis during infancy is a significant risk factor for persistence of wheezing episodes at school-age. One of the most important factors demonstrated to enhance the risk for persistence of asthma is an early allergic sensitization.

Asthma↗

[Skin tests for trophallergens and asthma].

The place of trophallergens in the allergy investigation of asthmatic children is controversial. Asthma is only rarely the isolated manifestation of food allergy. The clinical history is essential for research of the associated signs that reveal a food allergy. In the absence of these associated signs, the presence of a positive test for trophallergens only rarely reflects a true food allergy, of which the presence can only be assured by a double blind oral provocation test. In addition, in nurslings, the presence of a positive skin test to a trophallergen indicates atopy in the infant, but is only a mediocre predictive factor of eventual asthma, in the absence of an associated clinical allergy.

Allergens↗

Relationship between bronchial responsiveness and clinical evolution in infants who wheeze: a four-year prospective study.

Recurrent illness involving wheezing during the first years of life is transient in most children. The role of bronchial hyperresponsiveness as a factor influencing the persistence of wheezing from infancy to school age remains unknown. In a prospective study we investigated whether infants who wheezed and subsequently developed persistent asthma differed from infants who wheezed and later became asymptomatic either in the initial degree of bronchial hyperresponsiveness or in the persistence of bronchial hyperresponsiveness with age. One hundred and twenty-nine infants with three or more wheezing episodes before 2 yr of age were followed during 4 yr with a clinical evaluation and a methacholine challenge performed every 6 mo until the child was 4 yr old and once per year thereafter. The clinical score significantly improved with time in most children. The proportion of children with persistent wheezing after 2 and 4 yr of follow-up was only 31% and 20%, respectively. Persistent wheezers had significantly lower VmaxFRC values at initial evaluation and higher SRaw values at the end of follow-up than infants who became asymptomatic. We used transcutaneous oxygen tension (PtcO(2)) to measure the response to methacholine. No significant difference in PD(15) PtcO(2) between groups with subsequently different clinical progression was observed at initial evaluation. Bronchial hyperresponsiveness persisted 4 yr later in all children but children with persistent wheezing showed significantly lower PD(15) PtcO(2) values than children who became asymptomatic, as early as 30 mo of age. However, an acceptable early PD(15) PtcO(2) cut-off point predictive for subsequent clinical progression could not be identified. The level of bronchial hyperresponsiveness in infants who wheezed was not predictive of the persistence of asthma 4 yr later.

Asthma↗

Comparison of the forced oscillation technique and the interrupter technique for assessing airway obstruction and its reversibility in children.

The forced oscillation technique (FOT) and interrupter technique are particularly attractive for pediatric use as they require only passive cooperation from the patient. We compared the sensitivity and specificity of these methods for detecting airway obstruction and its reversibility in 118 children (3-16 yr) with asthma or chronic nocturnal cough. FOT (R(0) and R(16)) and interruption (Rint) parameters were measured at baseline and after bronchodilator inhalation (n = 94). Rint was significantly lower than R(0), especially in children with high baseline values. Baseline parameters were normalized for height and weight [R(SD)]. In children able to perform forced expiratory maneuvers (n = 93), the best discrimination between those with baseline FEV(1) < 80% or > or = 80% of predicted values was obtained with R(0)(SD). At a specificity of 80%, R(0)(SD) yielded 66% sensitivity, whereas Rint(SD) yielded only 33% sensitivity. Similarly, postbronchodilator changes in R(0)(SD) [DeltaR(0)(SD)] yielded the best discrimination between children with and without significant reversibility in FEV(1). At a specificity of 80%, DeltaR(0)(SD) yielded 67% sensitivity and DeltaRint(SD) yielded 58% sensitivity. In children unable to perform forced expiratory maneuvers (n = 25), FOT, contrary to the interrupter technique, clearly identified a subgroup of young children with high resistance values at baseline, which returned to normal after bronchodilation. We conclude that, in asthmatic children over 3 yr old, FOT measurements provide a more reliable evaluation of bronchial obstruction and its reversibility compared with the interrupter technique, especially in young children with high baseline values.

Adolescent↗

[Physiopathology of the cough].

Cough is initiated from organs innervated by the vagus nerve. The larynx and the lower airways are the main sites involved in cough initiation. Cough is mainly triggered by mechanical stimuli, especially at the laryngeal level, and also by inflammatory stimuli and chemical irritants. Two receptor types are involved in the cough reflex: the irritant receptors (IR) and the C fibers. IR are directly involved in cough initiation whereas stimulated C fibers act essentially through tachykinin release, which in turn activates IR. Cough in asthma was initially thought to be related to the bronchospasm reflex, but seems in fact mainly due to airway inflammation.

Bronchial Spasm↗

Diagnostic techniques in paediatric tuberculosis.

Accurate diagnosis of tuberculosis (TB) in children is crucial to provide effective treatment and to identify the undiagnosed adult who probably infected the child. The diagnosis of tuberculosis in children is often based only on epidemiologic, clinical, and radiographic findings. Fibre-optic bronchoscopy may also be helpful but the recovery of tuberculous bacilli, which establishes the diagnosis, is difficult in children. Rapid diagnostic tests such as direct amplification and serological tests have been developed to improve early diagnosis. Their sensitivity is higher than that of conventional mycobacterial culture in most paediatric studies.

Adolescent↗

Use of the forced oscillation technique to assess airway obstruction and reversibility in children.

The forced oscillation technique (FOT) is particularly attractive in a pediatric setting as it requires only passive cooperation from the child. We assessed the sensitivity and specificity of this method for detecting airway obstruction and its reversibility in 313 children (3 to 16 yr of age) with asthma or chronic nocturnal cough. Baseline and post-bronchodilator (n = 251) resistance were measured (R(0)) with the FOT. Baseline R(0) was normalized for height and weight [R(0)(SD)]. In children able to perform forced expiratory maneuvers (n = 181), R(0)(SD) was independently correlated with FEV(1) (p < 0.02) and maximal expiratory flow at 50% (MEF(50)) (p < 0.004). The optimal R(0)(SD) cutoff value given by receiver operating characteristic (ROC) curves to discriminate between children with baseline FEV(1) < 80% or >/= 80% of predicted values yielded 84% sensitivity and 73% specificity. Post-bronchodilator changes in R(0)(SD) [DeltaR(0)(SD)] were mostly correlated to changes in MEF(50). The optimal DeltaR(0)(SD) cutoff value to discriminate between children with the presence or absence of significant reversibility in FEV(1) yielded 69% sensitivity and 78% specificity. In children unable to perform forced expiratory maneuvers (n = 132), this DeltaR(0)(SD) cutoff clearly identified a subgroup of young children with high R(0) values at baseline, that returned to normal after bronchodilation. We conclude that FOT measurements allow reliable evaluation of bronchial obstruction and its reversibility in asthmatic children over 3 yr old.

Administration, Inhalation↗