Carina Majaesic

Reduced risk of physician-diagnosed asthma among children dwelling in a farming environment.

Background and objective:  Living in a farm environment has been reported to be associated with lower prevalence of asthma, based on the results of cross‐sectional studies. The objective of this longitudinal study was to determine whether living in a farm environment is associated with lower incidence of asthma among children.

Predictors for wheezing phenotypes in the first decade of life

Background and objective:  This study examined prenatal, perinatal and early childhood predictors of wheezing phenotypes in the first decade of life.

Prevalence of asthma and risk factors for asthma-like symptoms in Aboriginal and non-Aboriginal children in the northern territories of Canada

BACKGROUND Few studies have investigated the prevalence and risk factors of asthma in Canadian Aboriginal children. OBJECTIVE To determine the prevalence of asthma and asthma-like symptoms, as well as the risk factors for asthma-like symptoms, in Aboriginal and non-Aboriginal children living in the northern territories of Canada. METHODS Data on 2404 children, aged between 0 and 11 years, who participated in the North component of the National Longitudinal Survey of Children and Youth were used in the present study. A child was considered to have an asthma-like symptom if there was a report of ever having had asthma, asthma attacks or wheeze in the past 12 months. RESULTS After excluding 59 children with missing information about race, 1399 children (59.7%) were of Aboriginal ancestry. The prevalence of asthma was significantly lower (P<0.05) in Aboriginal children (5.7%) than non-Aboriginal children (10.0%), while the prevalence of wheeze was similar between Aboriginal (15.0%) and non-Aboriginal (14.5%) children. In Aboriginal children, infants and toddlers had a significantly greater prevalence of asthma-like symptoms (30.0%) than preschool-aged children (21.5%) and school-aged children (11.5%). Childhood allergy and a mothers daily smoking habit were significant risk factors for asthma-like symptoms in both Aboriginal and non-Aboriginal children. In addition, infants and toddlers were at increased risk of asthma-like symptoms in Aboriginal children. In analyses restricted to specific outcomes, a mothers daily smoking habit was a significant risk factor for current wheeze in Aboriginal children and for ever having had asthma in non-Aboriginal children. CONCLUSIONS Asthma prevalence appears to be lower in Aboriginal children than in non-Aboriginal children. The association between daily maternal smoking and asthma-like symptoms, which has been mainly reported for children living in urban areas, was observed in Aboriginal and non-Aboriginal children living in northern and remote communities in Canada.

Tryptophan catabolites regulate mucosal sensitization to ovalbumin in respiratory airways

Background:  Indoleamine 2,3 dioxygenase (IDO), the rate‐limiting enzyme in tryptophan catabolism, is important in generating tolerance at the foetal–maternal interface. Studies using 1‐methyl‐tryptophan (1‐MT), the specific inhibitor of IDO, showed that this enzyme is important in interferon‐gamma (IFN‐γ)‐dependent inhibition of allergic inflammation in the respiratory airway during immunotherapy.

A child's asthma quality of life rating does not significantly influence management of their asthma.

Children of parents who perceive their children have increased asthma severity use more medical services and reliever medication.

Cyclin-dependent kinase 5 regulates degranulation in human eosinophils.

Degranulation from eosinophils in response to secretagogue stimulation is a regulated process that involves exocytosis of granule proteins through specific signalling pathways. One potential pathway is dependent on cyclin‐dependent kinase 5 (Cdk5) and its effector molecules, p35 and p39, which play a central role in neuronal cell exocytosis by phosphorylating Munc18, a regulator of SNARE binding. Emerging evidence suggests a role for Cdk5 in exocytosis in immune cells, although its role in eosinophils is not known. We sought to examine the expression of Cdk5 and its activators in human eosinophils, and to assess the role of Cdk5 in eosinophil degranulation. We used freshly isolated human eosinophils and analysed the expression of Cdk5, p35, p39 and Munc18c by Western blot, RT‐PCR, flow cytometry and immunoprecipitation. Cdk5 kinase activity was determined following eosinophil activation. Cdk5 inhibitors were used (roscovitine, AT7519 and small interfering RNA) to determine its role in eosinophil peroxidase (EPX) secretion. Cdk5 was expressed in association with Munc18c, p35 and p39, and phosphorylated following human eosinophil activation with eotaxin/CCL11, platelet‐activating factor, and secretory IgA‐Sepharose. Cdk5 inhibitors (roscovitine, AT7519) reduced EPX release when cells were stimulated by PMA or secretory IgA. In assays using small interfering RNA knock‐down of Cdk5 expression in human eosinophils, we observed inhibition of EPX release. Our findings suggest that in activated eosinophils, Cdk5 is phosphorylated and binds to Munc18c, resulting in Munc18c release from syntaxin‐4, allowing SNARE binding and vesicle fusion, with subsequent eosinophil degranulation. Our work identifies a novel role for Cdk5 in eosinophil mediator release by agonist‐induced degranulation.

Internet-Based Asthma Education -- A Novel Approach to Compliance: A case Report

Asthma costs Canadians over 1.2 billion dollars per annum and, despite advances, many asthmatic patients still have poor control. An action plan, symptom diary and measurement of peak expiratory flow have been shown to improve clinical outcomes. Effective educational interventions are an important component of good care. However, many rural sites lack not only access to education but physician care as well. It is reasonable, therefore, that an Internet-based asthma management program may be used as an approach. In the present case report, a novel approach that may increase access in these poorly serviced areas is presented. In an Internet-based asthma management program, patients are reviewed by a physician, receive education and are given a unique password that provides program access. Patients record symptoms and peak expiratory flow rates. The present case report shows that a patient can be assisted through an exacerbation, thus averting emergency intervention and stabilizing control, even when travelling on another continent.

Changes to a pediatric sleep disordered breathing clinic improve wait-times and clinic efficiency.

Recognition of the impact of sleep disordered breathing (SDB) on health has increased referrals in pediatric respiratory medicine with a concomitant increase in wait‐times.

Three-Dimensional Modeled Custom-made Noninvasive Positive Pressure Ventilation Masks in an Infant

Three-Dimensional Modeled Custom-made Noninvasive Positive Pressure Ventilation Masks in an Infant Allison Carroll, Israel Amirav, Roger Marchand, Deb Olmstead, Heather Logan, Andrew Grosvenor, Carina Majaesic, Joanna MacLean, and Piush J. Mandhane Division of Pediatric Pulmonology, Department of Mechanical Engineering, and Institute of Reconstructive Sciences in Medicine, University of Alberta, Edmonton, Alberta, Canada

A pilot trial on the treatment of gastroesophageal reflux-related cough in infants.

BACKGROUND Diagnosing asthma in infancy is largely made on the basis of the symptoms of cough and wheeze. A similar presentation can be seen in neurologically normal infants with excessive gastroesophageal reflux (GER). There are no randomized placebo controlled studies in infants using proton pump inhibitors (PPI) alone or in addition to prokinetic agents. OBJECTIVES The primary objective was to confirm the presence of excessive GER in a population of infants that also had respiratory symptoms suggestive of asthma. Second, in a randomized placebo-controlled fashion, we determined whether treatment of GER with bethanacol and omeprazole could improve these respiratory symptoms. METHODS Infants (n=22) with a history of chronic cough and wheeze were enrolled, if they had evidence of GER by history and an abnormal pH probe or gastric emptying scan. Infants were randomly allocated to four treatment groups: placebo/placebo (PP), omeprazole plus bethanacol (OB), omeprazole/placebo (OP), bethanacol/placebo (BP). Evaluations by clinic questionnaire and exam, home diary, and pH probe data were done before, after study-medication and after open label of OB. RESULTS Nineteen children were studied. PP did not affect GER or respiratory symptoms, and did not decrease GER measured by pH probe. In contrast, OB decreased GER as measured by pH probe indices and parental assessment. In association, OB significantly decreased daytime coughing and improved respiratory scores. No adverse effects were reported. CONCLUSIONS In infants with a clinical presentation suggestive of chronic GER-related cough, the use of omeprazole and bethanacol appears to be viable therapeutic option.