Influence du statut calcique et en vitamine D sur l'homéostasie calcique : répercussion sur le calcium intracellulaire et sur l'os

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal

CFTR Depletion Results in Changes in Fatty Acid Composition and Promotes Lipogenesis in Intestinal Caco 2/15 Cells

Abnormal fatty acid composition (FA) in plasma and tissue lipids frequently occurs in homozygous and even in heterozygous carriers of cystic fibrosis transmembrane conductance regulator (CFTR) mutations. The mechanism(s) underlying these abnormalities remained, however, poorly understood despite the potentially CFTR contributing role.The aim of the present study was to investigate the impact of CFTR depletion on FA uptake, composition and metabolism using the intestinal Caco-2/15 cell line. shRNA-mediated cftr gene silencing induced qualitative and quantitative modifications in FA composition in differentiated enterocytes as determined by gas-liquid chromatography. With the cftr gene disruption, there was a 1,5 fold increase in the total FA amount, largely attributable to monounsaturated and saturated FA compared to controls. The activity of delta-7 desaturase, estimated by the 16:1(n-7)/16:0, was significantly higher in knockdown cells and consistent with the striking elevation of the n-7 FA family. When incubated with [14C]-oleic acid, CFTR-depleted cells were capable of quick incorporation and export to the medium concomitantly with the high protein expression of L-FABP known to promote intracellular FA trafficking. Accordingly, lipoprotein vehicles (CM, VLDL, LDL and HDL), isolated from CFTR knockdown cells, exhibited higher levels of radiolabeled FA. Moreover, in the presence of [14C]-acetate, knockdown cells exhibited enhanced secretion of newly synthesized phospholipids, triglycerides, cholesteryl esters and free FA, thereby suggesting a stimulation of the lipogenic pathway. Conformably, gene expression of SREBP-1c, a key lipogenic transcription factor, was increased while protein expression of the phosphorylated and inactive form of acetylCoA carboxylase was reduced, confirming lipogenesis induction. Finally, CFTR-depleted cells exhibited lower gene expression of transcription factors (PPARalpha, LXRalpha, LXRbeta and RXRalpha).Collectively, our results indicate that CFTR depletion may disrupt FA homeostasis in intestinal cells through alterations in FA uptake and transport combined with stimulation of lipogenesis that occurs by an LXR/RXR-independent mechanism. These findings exclude a contributing role of CFTR in CF-associated fat malabsorption

Emergencia del pensamiento algebraico en preescolar: estrategias de alumnos en relación con el concepto de equivalencia matemática

En este artículo presentaremos los resultados de un estudio de investigación colaborativa realizado en Ontario, Canadá. El objetivo era caracterizar las estrategias de los alumnos de preescolar asociadas a un pensamiento algebraico con respecto a la noción de equivalencia matemática. Para esto, propusimos dos tareas a 36 estudiantes de tres clases y analizamos sus estrategias. Nuestros resultados destacan 14 estrategias utilizadas por los estudiantes para trabajar con el concepto de equivalencia; entre estas, tres facilitarían el establecimiento de un razonamiento asociado con un pensamiento algebraico. Nuestra investigación muestra que los niños pueden razonar sobre la noción de equivalencia en un sentido relacional, y esto desde el preescolar, mucho antes de que se introduzca el álgebra formal

Emergencia del pensamiento algebraico en preescolar: estrategias de alumnos en relación con el concepto de equivalencia matemática

En este artículo presentaremos los resultados de un estudio de investigación colaborativa realizado en Ontario, Canadá. El objetivo era caracterizar las estrategias de los alumnos de preescolar asociadas a un pensamiento algebraico con respecto a la noción de equivalencia matemática. Para esto, propusimos dos tareas a 36 estudiantes de tres clases y analizamos sus estrategias. Nuestros resultados destacan 14 estrategias utilizadas por los estudiantes para trabajar con el concepto de equivalencia; entre estas, tres facilitarían el establecimiento de un razonamiento asociado con un pensamiento algebraico. Nuestra investigación muestra que los niños pueden razonar sobre la noción de equivalencia en un sentido relacional, y esto desde el preescolar, mucho antes de que se introduzca el álgebra formal

Emergencia del pensamiento algebraico en preescolar: estrategias de alumnos en relación con el concepto de equivalencia matemática

In this article, we present the results of a collaborative research conducted in Ontario. The objective of the study was to characterize preschool students’ algebraic thinking strategies concerning the notion of mathematical equivalence. To do so, we proposed two tasks to 36 students from three different classes and analyzed their strategies. Our results highlight 14 strategies used by students to work with the concept of equivalence; within these, three facilitated reasoning associated to algebraic thinking. Our research demonstrates that preschool children can reason on the notion of equivalence in a relational manner well before algebra is formally introduced.En este artículo presentaremos los resultados de un estudio de investigación colaborativa realizado en Ontario, Canadá. El objetivo era caracterizar las estrategias de los alumnos de preescolar asociadas a un pensamiento algebraico con respecto a la noción de equivalencia matemática. Para esto, propusimos dos tareas a 36 estudiantes de tres clases y analizamos sus estrategias. Nuestros resultados destacan 14 estrategias utilizadas por los estudiantes para trabajar con el concepto de equivalencia; entre estas, tres facilitarían el establecimiento de un razonamiento asociado con un pensamiento algebraico. Nuestra investigación muestra que los niños pueden razonar sobre la noción de equivalencia en un sentido relacional, y esto desde el preescolar, mucho antes de que se introduzca el álgebra formal

Communicating science in the digital and social media ecosystem : scoping review and typology of strategies used by health scientists

Background: The public's understanding of science can be influential in a wide range of areas related to public health, including policy making and self-care. Through the digital and social media ecosystem, health scientists play a growing role in public science communication (SC). Objective: This review aimed to (1) synthesize the literature on SC initiated by health scientists targeting the public in the digital and social media ecosystem and (2) describe the SC strategies and communication channels used. Methods: This scoping review was based on the Joanna Briggs Institute Methodological Framework. A systematic search was performed in 6 databases (January 2000 to April 2018). Title and abstract screening, full-text review, data charting, and critical appraisal were performed independently by two review authors. Data regarding included studies and communication channels were synthesized descriptively. A typology of SC strategies was developed using a qualitative and inductive method of data synthesis. Results: Among 960 unique publications identified, 18 met inclusion criteria. A third of publications scored good quality (6/18, 33%), half scored moderate quality (9/18, 50%), and less than a fifth scored low quality (3/18, 16%). Overall, 75 SC strategies used by health scientists were identified. These were grouped into 9 types: content, credibility, engagement, intention, linguistics, planification, presentation, social exchange, and statistics. A total of 5 types of communication channels were identified: social networking platforms (eg, Twitter), content-sharing platforms (eg, YouTube), digital research communities (eg, ResearchGate), personal blogs and websites (eg, WordPress), and social news aggregation and discussion platforms (eg, Reddit). Conclusions: Evidence suggests that multiple types of SC strategies and communication channels are used by health scientists concurrently. Few empirical studies have been conducted on SC by health scientists in the digital and social media ecosystem. Future studies should examine the appropriateness and effectiveness of SC strategies for improving public health-related outcomes and identify the barriers, facilitators, and ethical considerations inherent to the involvement of health scientists in the digital and social media ecosystem

Vitamin D in the prevention of exacerbations of asthma in preschoolers (DIVA): Protocol for a multicentre randomised placebo-controlled triple-blind trial

Introduction Preschoolers have the highest rate of emergency visits and hospitalisations for asthma exacerbations of all age groups, with most triggered by upper respiratory tract infections (URTIs) and occurring in the fall or winter. Vitamin D insufficiency is highly prevalent in Canadian preschoolers with recurrent asthma exacerbations, particularly in winter. It is associated with more URTIs and, in patients with asthma, more oral corticosteroid (OCS) use. Although evidence suggests that vitamin D supplements significantly decrease URTIs and asthma exacerbations requiring OCS, there is insufficient data in preschoolers. This study aims to determine the impact of vitamin D 3 supplementation on exacerbations requiring OCS, in preschoolers with recurrent URTI-induced asthma exacerbations. Methods and analysis This is a phase III, randomised, triple-blind, placebo-controlled, parallel-group multicentre trial of vitamin D 3 supplementation in children aged 1-5 years, with asthma triggered by URTIs and a recent history of frequent URTIs and OCS use. Children (n=865) will be recruited in the fall and early winter and followed for 7 months. They will be randomised to either the (1) intervention: two oral boluses of 100 000 international unit (IU) vitamin D 3 (3.5 months apart) with 400 IU vitamin D 3 daily; or (2) control: identical placebo boluses with daily placebo. The primary outcome is the number of exacerbations requiring OCS per child, documented by medical and pharmacy records. Secondary outcomes include number of laboratory-confirmed viral URTIs, exacerbation duration and severity, parent functional status, healthcare use, treatment deintensification, cost and safety. Ethics and dissemination This study has received ethical approval from all sites. Results will be disseminated via international conferences and manuscripts targeting paediatricians and respirologists, and to families of asthmatic children via our Quebec parents-partners outreach programme. If proven effective, findings may markedly influence the management of URTI-induced asthma in high-morbidity preschoolers and could be directly implemented into practice with an update to clinical guidelines. Trial registration number NCT03365687

Effects of implementation strategies on nursing practice and patient outcomes : a comprehensive systematic review and meta-analysis

Acknowledgements The authors wish to acknowledge the contribution of Jérémie Blondin for the development of search strategies and the search in bibliographical databases. We thank Ariane Ballard for contributing to study selection. We thank the individuals who responded to requests for additional data, including Jens Abraham, Patrick Akande, Marvin J. Bittner, Ian Blanco Mavillard, Nicolle P. G. Boumans, Marian C. Brady, Diane L. Carroll, Andrea Chaplin, Lorena Charrier, Francine M. Cheater, Lynn Chenoweth, Yeu-Hui Chuang, Lorenzo Cohen, Kelly Jo Cone, Susan Cortez, J. Randall Curtis, Barbara Davies, Tina Day, Marlies de Rond, Dennis de Ruijter, Helen Edwards, Mohamed Elzeky, Ruth Engelberg, David Evans, Valeria Fabre, Tobias Filmer, Christopher R. Friese, Marjorie Funk, Matthew Bidwell Goetz, Salla Grommi, Mary Beth Happ, Michael Hendryx, Manuela Hödl, Anita Huis, Alison Hutchinson, Yueh-Juan Hwu, Ali Khani Jeihooni, Céleste Johnston, Eileen F. S. Kaner, Zahra Karimian, Kristina H. Karvinen, Sedigheh Khanjari, Mahnaz Khatiban, Serena Koh, Sascha Köpke, Ruth Kleinpell, Una Kyriacos, Jan van Lieshout, Li-Chan Lin, Elizabeth Manias, Edward R. Marcantonio, Gabriele Meyer, Sandy Middleton, Tatsuya Morita, Janneke Noordman, Mary Patricia Nowalk, Jane Ogden, Christine Paul, James A. Rankin, Marilyn Rantz, Susan M. Ray, Staci S. Reynolds, Young Sook Roh, Jeffrey M. Rothschild, Reza Sadeghi, Trygve Johannes Lereim Sævareid, Parvin Mangolian Shahrbabaki, Davide Sisti, Wilma ten Ham-Baoyi, Sousan Valizadeh, Maritta Välimäki, Ayse Kacaroglu Vicdan, Thomas von Lengerke, Laura Wagner, Timothy Walsh, Marcia Weaver, Chistopher Weir, and Carla Zotti.Peer reviewe