A study of the content of some general science textbooks for grade nine

Thesis (Ed. M.)--Boston University, 194

L'avenir prometteur de l'apprentissage par problèmes en Soins infirmiers /

Bibliogr

5-Hydroxymethylcytosine Is Not Present in Appreciable Quantities in Arabidopsis DNA

5-Hydroxymethylcytosine (5-hmC) is an intermediate in active demethylation in metazoans, as well as a potentially stable epigenetic mark. Previous reports investigating 5-hydroxymethylcytosine in plants have reached conflicting conclusions. We systematically investigated whether 5-hmC is present in plant DNA using a range of methods. Using the model organism Arabidopsis thaliana, in addition to other plant species, we assayed the amount or distribution of 5-hydroxymethylcytosine by thin-layer chromatography, immunoprecipitation-chip, ELISA, enzymatic radiolabeling, and mass spectrometry. The failure to observe 5-hydroxymethylcytosine by thin-layer chromatography established an upper bound for the possible fraction of the nucleotide in plant DNA. Antibody-based methods suggested that there were low levels of 5-hmC in plant DNA, but these experiments were potentially confounded by cross-reactivity with the abundant base 5-methylcytosine. Enzymatic radiolabeling and mass spectrometry, the most sensitive methods for detection that we used, failed to detect 5-hydroxymethylcytosine in A. thaliana genomic DNA isolated from a number of different tissue types and genetic backgrounds. Taken together, our results led us to conclude that 5-hmC is not present in biologically relevant quantities within plant genomic DNA.National Science Foundation (U.S.). Graduate Research Fellowship Progra

Continuum de prévention des blessures sportives chez les jeunes athlètes, en collaboration avec les Jeux du Québec 2014

Travail d'intégration présenté à la Faculté de médecine en vue de l’obtention du grade de maîtrise en physiothérapieIntroduction/problématique : La participation des jeunes aux sports est en ascension constante depuis plusieurs années. C’est pourquoi l’équipe médicale des Jeux du Québec de Longueuil 2014 nous a consultés pour approfondir le système de surveillance actuel et les moyens pour prévenir les blessures. Objectifs : Définir les blessures les plus fréquentes dans les différentes disciplines des Jeux. Établir les composantes d’un système de surveillance adapté aux événements sportifs. Informer les athlètes, entraîneurs et parents sur la prévention des blessures. Stratégie méthodologique : Recension de la littérature dans les bases de données PubMed, Medline, Cinhal, Psychinfo. Résultats : Nous avons élaboré des fiches sur les blessures les plus fréquentes dans les sports chez les jeunes. Également, une définition du mot blessure a été conçue et a permis la création d’une grille d’intervention sur le terrain. Nous avons établi des lignes directrices sur les différentes modalités de prévention en physiothérapie pour la tendinopathie à l’épaule et l’entorse à la cheville chez les jeunes. Aussi, des recommandations sur les comportements à adopter chez les parents afin de diminuer le risque de blessures ont été proposées. Conclusion : Il est nécessaire que chaque personne impliquée auprès des athlètes agisse vers un même but : la prévention. Donc, nous recommandons aux Jeux du Québec d’effectuer une collecte de données à partir de la grille basée sur l’épidémiologie pour assurer un meilleur suivi des blessures. De plus, des recommandations sur la prévention seront mises sur le site Internet des Jeux

Skeletal muscle transcriptional coactivator PGC-1alpha mediates mitochondrial, but not metabolic, changes during calorie restriction

Calorie restriction (CR) is a dietary intervention that extends lifespan and healthspan in a variety of organisms. CR improves mitochondrial energy production, fuel oxidation, and reactive oxygen species (ROS) scavenging in skeletal muscle and other tissues, and these processes are thought to be critical to the benefits of CR. PGC-1alpha is a transcriptional coactivator that regulates mitochondrial function and is induced by CR. Consequently, many of the mitochondrial and metabolic benefits of CR are attributed to increased PGC-1alpha activity. To test this model, we examined the metabolic and mitochondrial response to CR in mice lacking skeletal muscle PGC-1alpha (MKO). Surprisingly, MKO mice demonstrated a normal improvement in glucose homeostasis in response to CR, indicating that skeletal muscle PGC-1alpha is dispensable for the whole-body benefits of CR. In contrast, gene expression profiling and electron microscopy (EM) demonstrated that PGC-1alpha is required for the full CR-induced increases in mitochondrial gene expression and mitochondrial density in skeletal muscle. These results demonstrate that PGC-1alpha is a major regulator of the mitochondrial response to CR in skeletal muscle, but surprisingly show that neither PGC-1alpha nor mitochondrial biogenesis in skeletal muscle are required for the whole-body metabolic benefits of CR

Identifying the metabolomic fingerprint of high and low flavonoid consumers

High flavonoid consumption can improve vascular health. Exploring flavonoid–metabolome relationships in population-based settings is challenging, as: (i) there are numerous confounders of the flavonoid–metabolome relationship; and (ii) the set of dependent metabolite variables are inter-related, highly variable and multidimensional. The Metabolite Fingerprint Score has been developed as a means of approaching such data. This study aims to compare its performance with that of more traditional methods, in identifying the metabolomic fingerprint of high and low flavonoid consumers. This study did not aim to identify biomarkers of intake, but rather to explore how systemic metabolism differs in high and low flavonoid consumers. Using liquid chromatography–tandem MS, 174 circulating plasma metabolites were profiled in 584 men and women who had complete flavonoid intake assessment. Participants were randomised to one of two datasets: (a) training dataset, to determine the models for the discrimination variables (n 399); and (b) validation dataset, to test the capacity of the variables to differentiate higher from lower total flavonoid consumers (n 185). The stepwise and full canonical variables did not discriminate in the validation dataset. The Metabolite Fingerprint Score successfully identified a unique pattern of metabolites that discriminated high from low flavonoid consumers in the validation dataset in a multivariate-adjusted setting, and provides insight into the relationship of flavonoids with systemic lipid metabolism. Given increasing use of metabolomics data in dietary association studies, and the difficulty in validating findings using untargeted metabolomics, this paper is of timely importance to the field of nutrition. However, further validation studies are required

Knockdown of Malic Enzyme 2 Suppresses Lung Tumor Growth, Induces Differentiation and Impacts PI3K/AKT Signaling

Mitochondrial malic enzyme 2 (ME2) catalyzes the oxidative decarboxylation of malate to yield CO2 and pyruvate, with concomitant reduction of dinucleotide cofactor NAD+ or NADP+. We find that ME2 is highly expressed in many solid tumors. In the A549 non-small cell lung cancer (NSCLC) cell line, ME2 depletion inhibits cell proliferation and induces cell death and differentiation, accompanied by increased reactive oxygen species (ROS) and NADP+/NADPH ratio, a drop in ATP, and increased sensitivity to cisplatin. ME2 knockdown impacts phosphoinositide-dependent protein kinase 1 (PDK1) and phosphatase and tensin homolog (PTEN) expression, leading to AKT inhibition. Depletion of ME2 leads to malate accumulation and pyruvate decrease, and exogenous cell permeable dimethyl-malate (DMM) mimics the ME2 knockdown phenotype. Both ME2 knockdown and DMM treatment reduce A549 cell growth in vivo. Collectively, our data suggest that ME2 is a potential target for cancer therapy

Ornithine decarboxylase supports ILC3 responses in infectious and autoimmune colitis through positive regulation of IL-22 transcription

Group 3 innate lymphoid cells (ILC3s) are RORγ