Publications by authors named "Audrey Pierre"

2 Publications

  • Page 1 of 1

Effectiveness of school-based dental sealant programs among children from low-income backgrounds: a pragmatic randomized clinical trial with a follow-up of 3 years.

Community Dent Oral Epidemiol 2016 10 28;44(5):504-11. Epub 2016 Jun 28.

Department of Dentistry at Jewish General Hospital, Montreal, QC, Canada.

Aim: A split-mouth randomized clinical trial was carried out to assess the effectiveness of a school-based dental sealant (SBDS) program for French children from low-income backgrounds within 3 years of follow-up. The secondary objectives were to determine the risk factors for the occurrence of new carious lesions (ICDAS 3-6) on first permanent molars, to evaluate the effectiveness of the program according to risk factors and to assess sealant retention.

Methods: The study included 276 6- to 7-year old pupils (457 pairs of first permanent molars) from Nice. The sealing was performed in first- or second-grade children. The first permanent molars were randomized into two groups: One received resin-based sealant and the other formed a nontreatment group. Carious lesions ICDAS 3-6 on permanent and primary teeth, visible plaque, streptococcus mutans and/or lactobacillus counts were recorded at baseline to assess individual caries risk (ICR). The putative confounders recorded at baseline were sex, grade level, and characteristics of first permanent molars. An intent-to-treat analysis was performed, where the study outcome was the occurrence of new carious lesions within 3 years of follow-up. Univariate and multivariate Cox proportional hazards models (hazard risk, HR) using the procedure PHREG with the option of Covsandwich were performed in SAS to assess the effectiveness of the SBDS program.

Results: At 3 years of follow-up, 228 children (378 tooth pairs) remained in the analysis. The survival analysis showed that first permanent molars that received sealants had 67% (adjusted HR: 0.33; 95% CI: 0.24-0.46) less risk of developing new carious lesions during all the follow-up than molars without sealant. In addition, children with carious lesions ICDAS 3-6 on permanent and primary teeth, that is, high ICR, had three times the risk of having a new carious lesion than others without, independently of the sealant treatment (adjusted HR: 3.00; 95% CI: 1.55-5.75). Effectiveness of the SBDS program at 3 years of follow-up depended on the presence of carious lesions ICDAS 3-6 (HR in 173 children with carious lesions: 0.32; 95% CI: 0.23-0.46) at baseline (HR in 103 children without carious lesions: 0.42; 95% CI: 0.16-1.12). Finally, the overall retention rate was 32.3%.

Conclusion: The effectiveness of the SBDS program was demonstrated in low socioeconomic areas. Selection of schoolchildren according to the presence of carious lesions ICDAS 3-6 should be considered in a SBDS program.
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October 2016

EphA4 is Involved in Sleep Regulation but Not in the Electrophysiological Response to Sleep Deprivation.

Sleep 2016 Mar 1;39(3):613-24. Epub 2016 Mar 1.

Center for Advanced Research in Sleep Medicine and Research Center, Hôpital du Sacré-Coeur de Montréal, Montreal, QC, Canada.

Study Objectives: Optimal sleep is ensured by the interaction of circadian and homeostatic processes. Although synaptic plasticity seems to contribute to both processes, the specific players involved are not well understood. The EphA4 tyrosine kinase receptor is a cell adhesion protein regulating synaptic plasticity. We investigated the role of EphA4 in sleep regulation using electrocorticography in mice lacking EphA4 and gene expression measurements.

Methods: EphA4 knockout (KO) mice, Clock(Δ19/Δ19) mutant mice and littermates, C57BL/6J and CD-1 mice, and Sprague-Dawley rats were studied under a 12 h light: 12 h dark cycle, under undisturbed conditions or 6 h sleep deprivation (SLD), and submitted to a 48 h electrophysiological recording and/or brain sampling at different time of day.

Results: EphA4 KO mice showed less rapid eye movement sleep (REMS), enhanced duration of individual bouts of wakefulness and nonrapid eye movement sleep (NREMS) during the light period, and a blunted daily rhythm of NREMS sigma activity. The NREMS delta activity response to SLD was unchanged in EphA4 KO mice. However, SLD increased EphA4 expression in the thalamic/hypothalamic region in C57BL/6J mice. We further show the presence of E-boxes in the promoter region of EphA4, a lower expression of EphA4 in Clock mutant mice, a rhythmic expression of EphA4 ligands in several brain areas, expression of EphA4 in the suprachiasmatic nuclei of the hypothalamus (SCN), and finally an unchanged number of cells expressing Vip, Grp and Avp in the SCN of EphA4 KO mice.

Conclusions: Our results suggest that EphA4 is involved in circadian sleep regulation.
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March 2016