L'auto-efficacité et le stage d'enseignement : le cas du candidat anglophone en enseignement du français langue seconde au secondaire en Ontario

L'étude rapportée dans ce mémoire portait sur l'auto-efficacité de candidats ontariens anglophones ayant complété un stage en enseignement du français langue seconde au niveau secondaire dans le cadre de leur formation universitaire. Après avoir établi le niveau d'auto-efficacité des candidats, nous avons tenté de cerner quelles expériences semblaient être en lien avec le niveau d'auto-efficacité exprimé par ces candidats. Neuf finissants de l'Université de Toronto ont rempli une version modifiée du Teachers' Sense of Efficacy Scale (Tschannen-Moran & Woolfolk Hoy, 2001) ainsi qu'un questionnaire sur les sources d'auto-efficacité. Étant donné le nombre restreint de participants et les scores d'auto-efficacité constamment élevés (moyenne 7.38, écart-type 0.61), nous n'avons pas été en mesure de faire des généralisations sur l'impact des différentes sources d'auto-efficacité étudiées. Toutefois, les résultats semblent indiquer que les circonstances de stage spécifiques à chaque candidat jouent un rôle important dans le développement de leurs croyances.The study reported in this paper dealt with the self-efficacy of Anglophone teacher candidates in Ontario who had completed a teaching practicum in French as a Second Language (FSL) during their university training. After establishing candidates' self-efficacy levels, the researcher attempted to determine which experiences seemed to be linked to candidates' self-efficacy levels. Nine University of Toronto teacher candidates completed a modified version of the Teachers' Sense of Efficacy Scale (Tschannen-Moran & Woolfolk Hoy, 2001) in addition to a questionnaire on sources of self-efficacy. Given the limited number of participants and their consistently high self-efficacy scores (mean 7.38, standard deviation 0.61), the researcher was not in a position to make generalisations as to the impact of the various sources of self-efficacy studied. However, the findings do seem to indicate that the particular circumstances in each teacher candidate's practicum play an important role in the development of their beliefs

The impact of age on prevalence of positive skin prick tests and specific IgE tests

SummaryAging is associated with modifications of the immune system, defined as immunosenescence. This could contribute to a reduced prevalence of allergic disease in the elderly population. In this regard, atopy has rarely been considered in the clinical assessment of the geriatric respiratory patient. This article is a review of the available literature assessing the impact of age on atopy. In the majority of papers, we found a lower prevalence of atopy in the most advanced ages, both in healthy subjects and in individuals affected by allergic respiratory diseases. Unfortunately, no large, longitudinal studies performed in the general population have been conducted to further explore this observation. Although available data seem to favor the decline of allergen sensitization with age, the prevalence of allergic sensitizations in the elderly population with respiratory symptoms is substantial enough to warrant evaluation of the atopic condition. From a clinical perspective, allergic reactions in older adults can have the same or even worse manifestations compared to young people. For this reasons, the evaluation of the atopic condition also in the geriatric patient is recommended. Thus, the role of atopy as it pertains to the diagnosis, therapy (adoption of preventive measure such as removal of environmental allergen or immunotherapy), and prognosis (influence on morbidity and mortality) of chronic respiratory illnesses in the elderly is addressed

Effects of exercise training on airway responsiveness and airway cells in healthy subjects

J Appl Physiol. 2010 Aug;109(2):288-94. Epub 2010 Jun 10. Effects of exercise training on airway responsiveness and airway cells in healthy subjects. Scichilone N, Morici G, Zangla D, Chimenti L, Dav\uec E, Reitano S, Patern\uf2 A, Santagata R, Togias A, Bellia V, Bonsignore MR. SourceDept. of Internal Medicine, Div. of Pulmonology (DIBIMIS Univ. of Palermo, "Villa Sofia-Cervello" Hospital, Via Trabucco 180, 90146 Palermo, Italy. [email protected] Abstract Airway responsiveness to methacholine (Mch) in the absence of deep inspirations (DIs) is lower in athletes compared with sedentary individuals. In this prospective study, we tested the hypothesis that a training exercise program reduces the bronchoconstrictive effect of Mch. Ten healthy sedentary subjects (M/F: 3/7; mean + or - SD age: 22 + or - 3 yr) entered a 10-wk indoor rowing exercise program on rowing ergometer and underwent Mch bronchoprovocation in the absence of DIs at baseline, at weeks 5 and 10, as well as 4-6 wk after the training program was completed. Exercise-induced changes on airway cells and markers of airway inflammation were also assessed by sputum induction and venous blood samples. Mean power output during the 1,000 m test was 169 + or - 49 W/stroke at baseline, 174 + or - 49 W/stroke at 5 wk, and 200 + or - 60 W/stroke at 10 wk of training (P < 0.05). The median Mch dose used at baseline was 50 mg/ml (range 25-75 mg/ml) and remained constant per study design. At the pretraining evaluation, the percent reduction in the primary outcome, the inspiratory vital capacity (IVC) after inhalation of Mch in the absence of DIs was 31 +/- 13%; at week 5, the Mch-induced reduction in IVC was 22 + or - 19%, P = 0.01, and it further decreased to 15 + or - 11% at week 10 (P = 0.0008). The percent fall in IVC 4-6 wk after the end of training was 15 + or - 11% (P = 0.87 vs. end of training). Changes in airway cells were not associated with changes in airway responsiveness. Our data show that a course of exercise training can attenuate airway responsiveness against Mch inhaled in the absence of DIs in healthy subjects and suggest that a sedentary lifestyle may favor development of airways hyperresponsiveness. Comment in J Appl Physiol. 2010 Aug;109(2):267-8. PMID:20538849[PubMed - in process

Longitudinal data reveal strong genetic and weak non-genetic components of ethnicity-dependent blood DNA methylation levels

Epigenetic architecture is influenced by genetic and environmental factors, but little is known about their relative contributions or longitudinal dynamics. Here, we studied DNA methylation (DNAm) at over 750,000 CpG sites in mononuclear blood cells collected at birth and age 7 from 196 children of primarily self-reported Black and Hispanic ethnicities to study race-associated DNAm patterns. We developed a novel Bayesian method for high-dimensional longitudinal data and showed that race-associated DNAm patterns at birth and age 7 are nearly identical. Additionally, we estimated that up to 51% of all self-reported race-associated CpGs had race-dependent DNAm levels that were mediated through local genotype and, quite surprisingly, found that genetic factors explained an overwhelming majority of the variation in DNAm levels at other, previously identified, environmentally-associated CpGs. These results indicate that race-associated blood DNAm patterns in particular, and blood DNAm levels in general, are primarily driven by genetic factors, and are not as sensitive to environmental exposures as previously suggested, at least during the first 7 years of life

Epithelial-Associated Inflammatory Pathways Underlie Residual Asthma Exacerbations in Urban Children Treated with Mepolizumab Therapy

Rationale: Identification of airway inflammatory pathways in asthma has proven essential to understanding mechanisms of disease and has led to effective personalized treatment with biologic therapies. However, relatively little is known about patterns of airway inflammation at the time of respiratory illnesses and how such patterns relate to responsiveness to biologic therapies. Methods: The MUPPITS-1 (n=106) and MUPPITS-2 (n=290) studies investigated asthma exacerbations in urban children with exacerbation-prone asthma and ≥150/microliter blood eosinophils. Children in both studies received guidelines-based asthma care; in MUPPITS-2, participants were additionally randomized (1:1) to placebo or mepolizumab. Nasal lavage samples were collected during respiratory illnesses for RNA-sequencing and analyzed by modular analysis to assess genome-wide expression patterns associated with exacerbation illnesses. Results: Among 284 illnesses, exacerbations that occurred in the absence of mepolizumab therapy showed significantly higher upregulation of eosinophil associated inflammatory pathways (fold change values [FC]=1.27-1.43, p-values\u3c0.05), including a Type-2 inflammation module composed of eosinophil, mast cell, and IL-13 response genes. In contrast, exacerbations that occurred while on mepolizumab therapy showed significantly higher upregulation of several epithelial inflammatory pathways (FC=1.36-1.64, p-values\u3c0.05) including TGF-β/Smad3 signaling, extracellular matrix production, and epidermal growth factor receptor signaling. Conclusions: These results indicate that novel inflammatory pathways, likely originating from the airway epithelium and distinct from Type-2 or eosinophilic inflammation, drive residual exacerbations that occur in children treated with mepolizumab therapy added to guideline-based care. These findings identify likely mechanisms of persistent disease expression in these children despite significant depletion of eosinophils and can identify novel treatment targets for future studies

Efficacy of the Enquiring About Tolerance (EAT) study among infants at high risk of developing food allergy.

BACKGROUND: The Enquiring About Tolerance (EAT) study was a randomized trial of the early introduction of allergenic solids into the infant diet from 3 months of age. The intervention effect did not reach statistical significance in the intention-to-treat analysis of the primary outcome. OBJECTIVE: We sought to determine whether infants at high risk of developing a food allergy benefited from early introduction. METHODS: A secondary intention-to-treat analysis was performed of 3 groups: nonwhite infants; infants with visible eczema at enrollment, with severity determined by SCORAD; and infants with enrollment food sensitization (specific IgE ≥0.1 kU/L). RESULTS: Among infants with sensitization to 1 or more foods at enrollment (≥0.1 kU/L), early introduction group (EIG) infants developed significantly less food allergy to 1 or more foods than standard introduction group (SIG) infants (SIG, 34.2%; EIG, 19.2%; P = .03), and among infants with sensitization to egg at enrollment, EIG infants developed less egg allergy (SIG, 48.6%; EIG, 20.0%; P = .01). Similarly, among infants with moderate SCORAD (15-<40) at enrollment, EIG infants developed significantly less food allergy to 1 or more foods (SIG, 46.7%; EIG, 22.6%; P = .048) and less egg allergy (SIG, 43.3%; EIG, 16.1%; P = .02). CONCLUSION: Early introduction was effective in preventing the development of food allergy in specific groups of infants at high risk of developing food allergy: those sensitized to egg or to any food at enrollment and those with eczema of increasing severity at enrollment. This efficacy occurred despite low adherence to the early introduction regimen. This has significant implications for the new national infant feeding recommendations that are emerging around the world

Mepolizumab Alters Regulation of Airway Type-2 Inflammation in Urban Children with Asthma by Disrupting Eosinophil Gene Expression but Enhancing Mast Cell and Epithelial Pathways

Rationale: Mepolizumab (anti-IL5) reduces asthma exacerbations in urban children. We previously utilized nasal transcriptomics to identify inflammatory pathways (gene co-expression modules) associated with exacerbations despite this therapy. To understand mepolizumab’s precise impact on these pathways, we assess gene co-expression and loss of correlation, “decoherence,” using differential co-expression network analyses. Methods: 290 urban children (6-17 years) with exacerbation-prone asthma and blood eosinophils ≥150/microliter were randomized (1:1) to q4 week placebo or mepolizumab injections added to guideline-based care for 52 weeks. Nasal lavage samples were collected before and during treatment for RNA-sequencing. Differential co-expression of gene networks was evaluated to assess interactions and regulatory aspects of type-2 and eosinophilic airway inflammation. Results: Mepolizumab, but not placebo, significantly reduced the overall expression of an established type-2 inflammation gene co-expression module (fold change=0.77, p=0.002) enriched for eosinophil, mast cell, and epithelial IL-13 response genes (242 genes). Mepolizumab uncoupled co-expression of genes in this pathway. During mepolizumab, but not placebo treatment, there was significant loss of correlation among eosinophil-specific genes including RNASE2 (EDN), RNASE3 (ECP), CLC, SIGLEC8, and IL5RA contrasting a reciprocal increase in correlation among mast cell-specific genes (TPSAB1, CPA3, FCER1A), T2 cytokines (IL4, IL5, and IL13), and POSTN. Conclusions: These results suggest mepolizumab disrupts the regulatory interactions of gene co-expression among airway eosinophils, mast cells and epithelium by interrupting transcription regulation in eosinophils with enhancement in mast cell and epithelial inflammation. This paradoxical effect may contribute to an incomplete reduction of asthma exacerbations and demonstrates how differential co-expression network analyses can identify targets for more precise therapies

Down-Modulation of Cockroach (CR) Allergen-specific Th2 Cell Responses Following Subcutaneous German Cockroach Allergen Immunotherapy (SCIT)

Rationale: The responses of T cells to subcutaneous allergen immunotherapy (SCIT) are not fully elucidated. We conducted a functional immunological evaluation of cockroach (CR) allergen-specific CD4+ T cell reactivity in the double-blinded, placebo-controlled, multi-center CRITICAL study. Methods: Participants (8-17 years of age) with mild to moderate, well-controlled asthma received 12 months of maintenance dosing of CR SCIT (n=20) or placebo (n=26). Peripheral blood mononuclear cells (PBMC) were isolated prior to, and after 12 months of therapy. CD4+ T cell responses at baseline and after treatment were assessed using overlapping peptide pools derived from 11 well-defined CR allergens and intracellular cytokine staining for IL-4, IFNg, and IL-10 production. T cell responses were further evaluated in terms of magnitude, cytokine polarization, and allergen immunodominance. Results: Significant down-modulation of the total magnitude of CD4+ T cell responses was observed with SCIT but not placebo, with a significant change between groups (-4.46±0.82 vs. −1.81±0.72, respectively, p = 0.020). Responses were driven by a decrease in IL-4 (-4.87±0.86 vs. −1.09±0.75, p = 0.002) with unaltered IFNg and IL-10 production, reflecting a shift towards a Th1 polarization profile (1.35±0.58 vs. −0.37±0.50, in SCIT and placebo respectively, p = 0.031). The largest effects were observed against the allergens Bla g 5 and Bla g 9, which are dominantly recognized, suggesting that dominant responses are susceptible to modulation. Conclusions: Our results demonstrate a significant down-regulation of CR-specific Th2 cell responses in urban children with asthma who received SCIT, compared with those who received placebo

Meta-analysis of genome-wide association studies of asthma in ethnically diverse North American populations.

Asthma is a common disease with a complex risk architecture including both genetic and environmental factors. We performed a meta-analysis of North American genome-wide association studies of asthma in 5,416 individuals with asthma (cases) including individuals of European American, African American or African Caribbean, and Latino ancestry, with replication in an additional 12,649 individuals from the same ethnic groups. We identified five susceptibility loci. Four were at previously reported loci on 17q21, near IL1RL1, TSLP and IL33, but we report for the first time, to our knowledge, that these loci are associated with asthma risk in three ethnic groups. In addition, we identified a new asthma susceptibility locus at PYHIN1, with the association being specific to individuals of African descent (P = 3.9 × 10(-9)). These results suggest that some asthma susceptibility loci are robust to differences in ancestry when sufficiently large samples sizes are investigated, and that ancestry-specific associations also contribute to the complex genetic architecture of asthma