101 research outputs found
Primary Care Physician Perceptions of Hearing Loss and Amplification: A Survey
The goal of this survey is to determine primary care physicians’ (PCP) views regarding hearing loss and hearing amplification. A questionnaire was created, using TypeForm©. Factors interrogated in the survey included structural aspects of the health care delivery system, presence of stigma among providers regarding hearing amplification, PCPs’ knowledge of hearing loss, the utility of amplification, official recommendations on screening and amplification, costs of hearing aids and risks of untreated hearing loss, and practitioners’ viewpoints and practice behaviors surrounding hearing loss and amplification. The survey instrument is comprised of four domains: 1) demographics, 2) knowledge of hearing loss and amplification, 3) preferences of hearing loss and amplification and 4) practice behaviors relating to hearing loss and amplification. Questions were created and collected from previous research studies of PCPs’ knowledge of hearing loss. The aim of this project is to contribute to our understanding of the relationship between PCP’s demographics, knowledge, preferences and practice behaviors in terms of hearing health care. Ultimately, the objective of this research is to help improve the hearing health of individuals who report hearing difficulties to PCPs in the first place, by encouraging better communication between PCPs and hearing health professionals for patients
Étude des effets d'une approche synthétique et multisensorielle de lecture sur la reconnaissance des mots et l'orthographe chez une élève ayant les caractéristiques d'une dyslexie mixte
Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal
Rôle de la somatostatine dans la plasticité synaptique des interneurones somatostatinergiques de l’hippocampe
Dans la région CA1 de l’hippocampe, une population d’interneurones exprimant la somatostatine (SOM-INs) est reconnue pour une potentialisation à long terme (PLT) dépendante des récepteurs métabotropes du glutamate de type 1a (mGluR1a) à leurs synapses excitatrices provenant des cellules pyramidales (CP). Il a récemment été démontré que cette PLT est induite par l’apprentissage contextuel lié à la peur, illustrant l’importance de cette PLT des SOM-INs dans l’apprentissage et la mémoire. Cependant, l’implication du neuropeptide somatostatine (SST) dans cette PLT demeure inconnue. Dans la présente étude, le rôle de la SST dans la PLT dépendante des mGluR1a a été étudié, tout comme, l’effet de la somatostatine-14 (SST-14) exogène aux synapses excitatrices des SOM-INs. Pour ce faire, des souris transgéniques exprimant la « enhanced yellow fluorescent protein » (eYFP) sous le contrôle du promoteur de la SST ont été utilisées. Des enregistrements électrophysiologiques jumelés à une approche pharmacologique ont été réalisés sur ces souris. Les résultats suggèrent que la SST-14 exogène engendre une PLT persistante grâce aux récepteurs à la somatostatine 1-5 (SST1-5), aux synapses excitatrices des SOM-INs, mais n’affecte pas les synapses des CP ou bien des interneurones exprimant la parvalbumine (PV-INs). Cette potentialisation induite par SST-14 était indépendante des récepteurs à l’acide N-méthyl-D-aspartique (NMDAR) et mGluR1a, dépendante de l’activité synaptique concomitante et inhibée par le blocage des récepteurs GABAA. De plus, la PLT dépendante des récepteurs mGluR1a a été affectée par l’inhibition des SST1-5 ou bien par un traitement avec de la cystéamine suggérant un rôle pour de la SST endogène dans cette PLT. Nos résultats suggèrent que la SST endogène pourrait contribuer à la PLT hébbienne aux synapses excitatrices des SOM-INs en contrôlant l’inhibition GABAA. La SST aurait alors un rôle dans la modulation de la plasticité à long terme des SOM-INs qui pourrait être important dans la mémoire dépendante de l’hippocampe.The CA1 region of the hippocampus includes a population of GABAergic interneurons expressing somatostatin (SOM-INs). This type of interneurons displays a long-term potentiation (LTP) dependant on type 1a metabotropic glutamate receptors (mGluR1a) at their excitatory synapses from pyramidal cells (PC). It was recently demonstrated that mGluR1a dependent LTP can be induce by contextual fear learning showing an important role of this LTP in learning and memory. However, the implication of the peptide somatostatin (SST) in this LTP remains unknown. In the present study, the role of SST in mGluR1 dependent LTP and the effect of exogenous somatostatin-14 (SST-14) onto excitatory synapses of SOM-INs were investigated. To do this, transgenic mice expressing enhanced yellow fluorescent protein (eYFP) under the control of the promoter of SST were used. Patch clamp recordings and pharmacological approaches were used with these mice. Results suggested that application of exogenous SST-14 induces a LTP through type 1-5 somatostatin receptors (SST1-5) of excitatory synapses of SOM-INs but does not affect synapses of PC or parvalbumin-expressing interneurons (PV-INs). This LTP induced by SST-14 was independent of N-methyl-D-aspartate receptor (NMDAR) and mGluR1a, activity dependent, and prevented by blocking GABAA receptors. Furthermore, mGluR1a dependent LTP was prevented by inhibition of SST1-5 and by depletion of SST by cysteamine treatment, suggesting a role of endogenous SST in LTP. Our results indicate that endogenous SST may contribute to Hebbian LTP at excitatory synapses by controlling GABAA inhibition. SST would then have a role in regulating SOM-INs LTP that may be important for hippocampus dependent memory processes
Divergent Reactivity of Thioalkynes in Lewis Acid Catalyzed Annulations with Donor-Acceptor Cyclopropanes
Efficient methods for the convergent synthesis of (poly) cyclic scaffolds are urgently needed in synthetic and medicinal chemistry. Herein, we describe new annulation reactions of thioalkynes with phthalimide-substituted donor-acceptor cyclopropanes, which gave access to highly substituted cyclopentenes and polycyclic ring systems. With silyl-thioalkynes, the Lewis acid catalyzed[3+2] annulation reaction with donor-acceptor cyclopropanes took place to afford 1-thio-cyclopenten-3-amines. On the other hand, an unprecedented polycyclic compound was formed with alkyl-thioalkynes through a reaction pathway directly involving the phthalimide group. The two transformations proceeded in good yields and tolerated a large variety of functional groups
Synthesis of (Carbo) nucleoside Analogues by [3+2] Annulation of Aminocyclopropanes
(Carbo) nucleoside derivatives constitute an important class of pharmaceuticals, yet there are only few convergent methods to access new analogues. Here, we report the first synthesis of thymine-, uracil-, and 5-fluorouracil-substituted diester donor-acceptor cyclopropanes and their use in the indium-and tin-catalyzed [3+2] annulations with aldehydes, ketones, and enol ethers. The obtained diester products could be easily decarboxylated and reduced to the corresponding alcohols. The method gives access to a broad range of new (carbo) nucleoside analogues in only four or five steps and will be highly useful for the synthesis of libraries of bioactive compounds
[4+2]-Annulations of Aminocyclobutanes
The first [4 + 2]-annulation between aminocyclobutanes and aldehydes to access tetrahydropyranyl amines is reported. With phthalimido cyclobutane dicarboxylates and aromatic aldehydes, tetrahydropyrans were obtained in 53-92% yield and 3:1-17:1 dr using scandium triflate or iron trichloride as catalyst. The use of thymine- or fluorouracil-substituted cyclobutanes gave direct access to six-membered ring nucleoside analogues. Finally, the [4 + 2]-annulation between aminocyclobutanes and enol ethers led to the corresponding cyclohexylamines
Taming Hypervalent Bonds and Strained Rings for Catalysis and Synthesis
Improving the synthesis of complex organic molecules is essential for progress in many fields such as medicine, agrochemicals or materials. Since 2007, our laboratory has been focusing on the development of non-classical bond disconnections based on the use of small, energy-loaded organic molecules: hypervalent iodine reagents and strained rings. In this overview article, we report our progress since 2011 in these areas. The use of cyclic hypervalent iodine reagents has been extended to the C2-selective alkynylation of indoles, the domino cyclization alkynylation of allenes, the alkynylation of thiols and the azidation of carbonyl compounds. Amino-substituted aminocyclopropanes and aminocyclobutanes were used in [3+2] and [4+2] annulations to access nitrogen-rich building blocks, including nucleoside analogues. The first example of dynamic kinetic [3+2] annulation of aminocyclopropanes with both enol ethers and aldehydes was also reported
1-Alkynyltriazenes as Functional Analogues of Ynamides
The chemical reactivity of 1-alkynyltriazenes has been investigated and is found to parallel the reactivity of ynamides. The similarity in reactivity of these two classes of compounds is demonstrated by addition reactions with acids, by cycloaddition reactions with ketenes, tetracyanoethene, and cyclopropanes, as well as by intramolecular cyclization reactions. The presence of reactive triazene groups in the products enables subsequent transformations. Overall, our results suggest that 1-alkynyltriazenes should become valuable reagents in synthetic organic chemistry
A comparative effectiveness study of the breaking the cycle and Maxxine Wright intervention programs for substance-involved mothers and their children: study protocol
Abstract Background Children of substance-involved mothers are at especially high risk for exposure to adverse childhood experiences (ACEs) and poor mental health and development. Early interventions that support mothers, children, and the mother-child relationship have the greatest potential to reduce exposure to early adversity and the mental health problems associated with these exposures. Currently, there is a lack of evidence from the real-world setting demonstrating effectiveness and return on investment for intervention programs that focus on the mother-child relationship in children of substance-involved mothers. Methods One hundred substance-involved pregnant and/or parenting women with children between the ages of 0–6 years old will be recruited through the Breaking the Cycle and Maxxine Wright intervention programs, in Toronto, Ontario, Canada and Surrey, British Columbia, Canada, respectively. Children’s socioemotional development and exposure to risk and protective factors, mothers’ mental health and history of ACEs, and mother-child relationship quality will be assessed in both intervention programs. Assessments will occur at three time points: pre-intervention, 12-, and 24-months after engagement in the intervention program. Discussion There is a pressing need to identify interventions that promote the mental health of infants and young children exposed to early adversity. Bringing together an inter-disciplinary research team and community partners, this study aligns with national strategies to establish strong evidence for infant mental health interventions that reduce child exposure to ACEs and support the mother-child relationship. This study was registered with clinicaltrials.gov (NCT05768815) on March 14, 2023
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