Perceptions of asthma and exercise in adolescents with and without asthma.

OBJECTIVE: To elicit the views of adolescents, with and without asthma, about exercise and asthma, and the perceived benefits of and barriers to participation. The adolescent views elicited would subsequently inform the design of a high-intensity exercise intervention to improve asthma control. METHODS: Fifty-four adolescents (age 13.1 ± 0.9 years; 26 with asthma) participated in twelve semi-structured group interviews. Questions were structured around knowledge, attitudes and beliefs towards asthma and its impact on exercise participation and lifestyle. The interviews were transcribed verbatim, thematically analysed and presented via diagrams of emergent themes. Ethical approval was granted by the institutional research ethics committee. RESULTS: Fear of an asthma attack emerged as the main barrier to exercise, with many adolescents with asthma withdrawing from exercise as a coping strategy; many healthy adolescents perceived this withdrawal as laziness or an excuse. Despite this, the majority (81%) of adolescents with asthma reported exercise to be their most enjoyable activity. Adolescents suggested incorporating mixed activities, such as team games (e.g., rounders, football, netball), for future interventions to ensure adherence. CONCLUSIONS: Whilst exercise is important in the management of asthma, the tendency of those with asthma to withdraw from exercise to avoid adverse events could be addressed through a games-based high-intensity exercise intervention. Furthermore, educating all adolescents on asthma could simultaneously reduce stigmatisation and enhance exercise engagement.

Which intravenous bronchodilators are being administered to children presenting with acute severe wheeze in the UK and Ireland?

During a prospective 10-week assessment period, 3238 children aged 1-16 years presented with acute wheeze to Paediatric Emergency Research in the UK and Ireland centres. 110 (3.3%) received intravenous bronchodilators. Intravenous magnesium sulfate (MgSO4) was used in 67 (60.9%), salbutamol in 61 (55.5%) and aminophylline in 52 (47.3%) of cases. In 35 cases (31.8%), two drugs were used together, and in 18 cases (16.4%), all three drugs were administered. When used sequentially the most common order was salbutamol, then MgSO4, then aminophylline. Overall, 30 different intravenous treatment regimens were used varying in drugs, dose, rate and duration.

The viral aetiology of croup and recurrent croup.

BACKGROUND: Historically croup was subdivided into classic "viral" croup with associated viral upper respiratory tract infections, and recurrent or spasmodic croup where asthma and allergies were thought more important. METHODS: All children admitted to the University Hospital of Wales with croup in 2003 were eligible. Baseline demographics including croup score were recorded and per-nasal swabs taken for virus detection by RT-PCR. Recurrent croup was defined as at least one other admission for croup in the preceding or following 3 years. RESULTS: Sixty (29.4%) children entered the study, and a viral pathogen was detected in 41 (68%). There was no significant difference in the rate of virus detection between those with single episode croup and recurrent croup. CONCLUSIONS: The aetiologies of viral and recurrent croup appear similar.

A sweat test centered protocol for the disclosure and diagnosis of cystic fibrosis in a newborn screening program.

We describe the development of a sweat test centered protocol for disclosure and diagnosis of Cystic Fibrosis. Our protocol aims to identify infants early, minimizes the time of uncertainty for the parents, and yet gives them time to begin to come to terms with the possibility of diagnosis. Over a 9-year period 295,247 newborn infants were screened for CF in Wales, of whom 121 infants were diagnosed as having CF. During this period there were four false negatives (3.3%). Parental satisfaction with the process appears very high 6 months after disclosure.

Asthma prevalence in 1973, 1988 and 2003.

BACKGROUND: A study was undertaken to see whether the prevalence of asthma has changed since a survey was conducted in 1988, using the same methods that showed an increase during the previous 15 years. METHODS: A survey of 12 year old children was conducted in schools in South Wales where surveys had taken place in 1973 and 1988. The survey comprised a parentally completed questionnaire and an exercise challenge test, performed when no bronchodilator had been recently used. RESULTS: In 1973, 1988, and 2003, questionnaires were obtained for 817, 965 and 1148 children, respectively; the exercise test was performed by 812, 960 and 1019 children, respectively. The prevalence of reported wheeze in the last year rose during each 15 year period (9.8%, 15.2%, 19.7%), with an even steeper rise in reported asthma ever (5.5%, 12.0%, 27.3%). There was a continued increase in wheeze attributed to running, in terms of all children (5.8%, 10.5%, 16.0%) and also as the proportion of those with a history of wheeze (34.1%, 47.0%, 57.3%). The use of inhaled corticosteroids (not available in 1973) increased fourfold between 1988 and 2003. The prevalence of exercise induced bronchoconstriction rose between 1973 and 1988 but had declined by 2003. CONCLUSIONS: The rise in the prevalence of asthmatic symptoms has continued since 1988. This appears to conflict with a reported recent decline, unless asthma prevalence peaked in the 1990s. The decline in exercise induced bronchoconstriction is probably attributable to better control of the disease as more children are now using inhaled corticosteroids as preventive treatment.

Reduced iC3b-mediated phagocytotic capacity of pulmonary neutrophils in cystic fibrosis.

Cystic fibrosis (CF) is characterized by a neutrophil-dominated chronic inflammation of the airways with persistent infections. In order to investigate whether neutrophils contribute to an inadequacy in the pulmonary defence mechanism, the phagocytic activity of pulmonary and peripheral blood neutrophils from CF and non-CF respiratory patients were compared. Neutrophils were isolated from both the blood and bronchoalveolar lavage fluid of 21 patients with CF (12 male, 9 female; mean age 7.5 years, range 0.25-16.4 years) and 17 non-CF subjects (9 male, 8 female; mean age 5.4 years, range 0.2-13.1 years). The ex vivo phagocytic rate of normal pulmonary neutrophils to internalize zymosan particles opsonized with iC3b was faster than that of circulating neutrophils (P < 0.05), but the maximum capacity (9 particles/cell) was similar. In contrast, pulmonary neutrophils from patients with CF had a lower phagocytic capacity than circulating neutrophils either from the same patients or from normal subjects. This deficiency could not be attributed to (i) the cell surface density of CR3 (CD18/CD11b) receptors, which were not significantly different between the other groups (ii) the signalling ability of the CR3 receptors, using cytosolic free Ca(2+) signalling as the receptor activity read-out or (iii) a decrease in cellular ATP concentration. As CFTR was not detectable on neutrophils from any source by either histochemistry or Western blotting, it was concluded that the reduced phagocytic capacity was not the direct result of a CFTR mutation, but was attributed to a failure of neutrophil phagocytic priming during translocation into the CF lung.

Sildenafil (Viagra) corrects DeltaF508-CFTR location in nasal epithelial cells from patients with cystic fibrosis.

BACKGROUND: Most patients with cystic fibrosis (CF) have a DeltaF508 mutation resulting in abnormal retention of mutant gene protein (DeltaF508-CFTR) within the cell. This study was undertaken to investigate DeltaF508-CFTR trafficking in native cells from patients with CF with the aim of discovering pharmacological agents that can move DeltaF508-CFTR to its correct location in the apical cell membrane. METHOD: Nasal epithelial cells were obtained by brushing from individuals with CF. CFTR location was determined using immunofluorescence and confocal imaging in untreated cells and cells treated with sildenafil. The effect of sildenafil treatment on CFTR chloride transport function was measured in CF15 cells using an iodide efflux assay. RESULTS: In most untreated CF cells DeltaF508-CFTR was mislocalised within the cell at a site close to the nucleus. Exposure of cells to sildenafil (2 hours at 37 degrees C) resulted in recruitment of DeltaF508-CFTR to the apical membrane and the appearance of chloride transport activity. Sildenafil also increased DeltaF508-CFTR trafficking in cells from individuals with CF with a single copy DeltaF508 (DeltaF508/4016ins) or with a newly described CF trafficking mutation (R1283M). CONCLUSIONS: The findings provide proof of principle for sildenafil as a DeltaF508-CFTR trafficking drug and give encouragement for future testing of sildenafil and related PDE5 inhibitors in patients with CF.

The effect of asthma and its treatment on growth.

Asthma has little, if any, significant effect on attained adult height. Untreated asthma results in a delay of puberty by approximately 1.3 years, and pubertal delay is likely to explain the majority of apparent growth failure in asthmatics. All currently available inhaled corticosteroids (ICS) result in growth suppression at conventional doses (400 microg/day of beclomethasone dipropionate equivalent), but the growth suppressive effects are relatively short lived, after which growth reverts to pretreatment levels. Younger, prepubertal children, appear more sensitive to the growth suppressive effects of ICS. Asthmatic children receiving conventional doses of ICS (400 microg/day of BDP equivalent) will attain an adult height indistinguishable from their predicted adult height (based on their mid parental height), and no different from non-asthmatics. Adult height could possibly be decreased in severe asthmatics, but this is unlikely to be greater than a 1.2 cm decrement. Recent longitudinal studies offer reassurance that at conventional doses ICS do not have significant long term effects on growth, and that their benefits consistently outweigh their side effects.

Effect of a microaerosol filter on spirometry in children with cystic fibrosis.

AIM: To measure the effect of an in-line microaerosol filter on spirometric values in cystic fibrosis (CF). METHODS: Twenty-six subjects with CF undertook a randomized, open, cross-over comparison of spirometry with and without an in-line filter. RESULTS: The filter had no significant effect on spirometric parameters nor was there any order effect. Measurement error was unrelated to the magnitude of the measurement. CONCLUSION: In-line microaerosol filters do not affect spirometric values or variability in children with CF.