16 results on '"VALOIS, L."'
Search Results
2. Fast and Reproducible 96-Well Plate-Based Method for the Evaluation of the Antigerminative Potential of Plant Extracts and Phytotoxic Compounds.
- Author
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Flieller, G., Riffault-Valois, L., Bergaentzlé, M., and Ennahar, S.
- Published
- 2022
- Full Text
- View/download PDF
3. Do conventional and innovative medical schools recruit different students?
- Author
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MAHEUX, B., BÉLAND, F., PINEAULT, R., RIVEST, P., and VALOIS, L.
- Published
- 1989
- Full Text
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4. Complementary Strategies to Unlock Biosynthesis Gene Clusters Encoding Secondary Metabolites in the Filamentous Fungus Podospora anserina .
- Author
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Shen L, Roullier C, Porée FH, Gaslonde T, Riffault-Valois L, Grovel O, Ruprich-Robert G, and Chapeland-Leclerc F
- Abstract
The coprophilous ascomycete Podospora anserina is known to have a high potential to synthesize a wide array of secondary metabolites (SMs). However, to date, the characterization of SMs in this species, as in other filamentous fungal species, is far less than expected by the functional prediction through genome mining, likely due to the inactivity of most SMs biosynthesis gene clusters (BGCs) under standard conditions. In this work, our main objective was to compare the global strategies usually used to deregulate SM gene clusters in P. anserina , including the variation of culture conditions and the modification of the chromatin state either by genetic manipulation or by chemical treatment, and to show the complementarity of the approaches between them. In this way, we showed that the metabolomics-driven comparative analysis unveils the unexpected diversity of metabolic changes in P. anserina and that the integrated strategies have a mutual complementary effect on the expression of the fungal metabolome. Then, our results demonstrate that metabolite production is significantly influenced by varied cultivation states and epigenetic modifications. We believe that the strategy described in this study will facilitate the discovery of fungal metabolites of interest and will improve the ability to prioritize the production of specific fungal SMs with an optimized treatment.
- Published
- 2022
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5. Neurotrophic effects of Botulinum neurotoxin type A in hippocampal neurons involve activation of Rac1 by the non-catalytic heavy chain (HC C /A).
- Author
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Solabre Valois L, Shi VH, Bishop P, Zhu B, Nakamura Y, Wilkinson KA, and Henley JM
- Abstract
Botulinum neurotoxins (BoNTs) are extremely potent naturally occurring poisons that act by silencing neurotransmission. Intriguingly, in addition to preventing presynaptic vesicle fusion, BoNT serotype A (BoNT/A) can also promote axonal regeneration in preclinical models. Here we report that the non-toxic C-terminal region of the receptor-binding domain of heavy chain BoNT/A (HC
C /A) activates the small GTPase Rac1 and ERK pathway to potentiate axonal outgrowth, dendritic protrusion formation and synaptic vesicle release in hippocampal neurons. These data are consistent with HCC /A exerting neurotrophic properties, at least in part, independent of any BoNT catalytic activity or toxic effect., Competing Interests: LSV received a collaborative scholarship from Ipsen to fund his PhD. None of the workers at Ipsen participated in the design, performance or analysis of the experiments, or in writing the manuscript, but they did provide facilities and reagents necessary for completion of the work., (© 2021 The Authors.)- Published
- 2021
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6. Endocytosis, trafficking and exocytosis of intact full-length botulinum neurotoxin type a in cultured rat neurons.
- Author
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Solabre Valois L, Wilkinson KA, Nakamura Y, and Henley JM
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- Animals, Cells, Cultured, Endosomes metabolism, Membrane Microdomains metabolism, Rats, Wistar, Receptor, Fibroblast Growth Factor, Type 3 metabolism, Botulinum Toxins, Type A pharmacology, Endocytosis, Exocytosis, Neurons metabolism
- Abstract
Botulinum toxin A (BoNT/A) is a potent neurotoxin that acts primarily by silencing synaptic transmission by blocking neurotransmitter release. BoNT/A comprises a light chain (LC/A) intracellular protease and a heavy chain (HC/A) composed of a receptor binding domain (HC
C /A) and a translocation domain (HCN /A) that mediates cell entry. Following entry into the neuron, the disulphide bond linking the two peptide chains is reduced to release the LC/A. To gain better insight into the trafficking and fate of BoNT/A before dissociation we have used a catalytically inactive, non-toxic full-length BoNT/A(0) mutant. Our data confirm that BoNT/A(0) enters cortical neurons both in an activity-dependent manner and via a pathway dependent on fibroblast growth factor receptor 3 (Fgfr3) signalling. We demonstrate that both dynamin-dependent endocytosis and lipid rafts are involved in BoNT/A internalisation and that full-length BoNT/A(0) traffics to early endosomes. Furthermore, while a proportion of BoNT/A remains stable in neurons for 3 days, BoNT/A degradation is primarily mediated by the proteasome. Finally, we demonstrate that a fraction of the endocytosed full-length BoNT/A(0) is capable of exiting the cell to intoxicate other neurons. Together, our data shed new light on the entry routes, trafficking and degradation of BoNT/A, and confirm that trafficking properties previously described for the isolated HCC /A receptor binding domain of are also applicable to the intact, full-length toxin., Competing Interests: Declaration of Competing Interest Luis Solabre Valois was funded by a collaborative PhD scholarship from Ipsen and the University of Bristol. Ipsen provided BoNT/A(0) molecules, anti-BoNT/A antibodies and valuable intellectual interaction and advice., (Copyright © 2020 The Authors. Published by Elsevier B.V. All rights reserved.)- Published
- 2020
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7. Online acetylcholinesterase inhibition evaluation by high-performance liquid chromatography-mass spectrometry hyphenated with an immobilized enzyme reactor.
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Yuan Y, Zhao M, Riffault-Valois L, Ennahar S, Bergaentzlé M, and Marchioni E
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- Acetylcholine analysis, Acetylcholinesterase chemistry, Bioreactors, Galantamine analysis, Limit of Detection, Lycoris chemistry, Plant Extracts chemistry, Reproducibility of Results, Cholinesterase Inhibitors analysis, Chromatography, High Pressure Liquid methods, Enzymes, Immobilized analysis, Mass Spectrometry methods, Online Systems
- Abstract
A high-performance liquid chromatography-mass spectrometry technique hyphenated on-line with an immobilized enzyme reactor (IMER) was developed by the use of 3 known acetylcholinesterase (AChE) inhibitors (galanthamine, huperzine A and tacrine). This bioanalytical device allows qualitative comparison of the inhibitory strengths of AChE inhibitors. The AChE inhibitory strengths were evaluated and compared by the corresponding acetylcholine peak areas (mass signal) obtained after a chromatographic separation and the elution through the IMER. Only one injection of the analytes is needed to get this comparative analysis. This bioanalytical device was then applied to the extract of a natural plant, Lycoris radiata, which is known to contain AChE inhibitors such as galanthamine and lycoramine. Aside from the demonstration of the inhibitory activity of the two known AChE inhibitors, the AChE inhibitory activity of another compound (dihydro-latifaliumin C) was revealed. This is the first report describing the AChE inhibitory activity of this compound., (Copyright © 2019. Published by Elsevier B.V.)
- Published
- 2020
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8. Health risk associated with the oral consumption of "Chiniy-tref", a traditional medicinal preparation used in Martinique (French West Indies): Qualitative and quantitative analyses of aristolochic acids contained therein.
- Author
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Riffault-Valois L, Wattez C, Langrand J, Boucaud-Maitre D, Gaslonde T, Colas C, Nossin E, Blateau A, Michel S, and Cachet X
- Subjects
- Animals, Aristolochic Acids chemistry, Larva chemistry, Martinique, Toxins, Biological analysis, Toxins, Biological chemistry, Aristolochia chemistry, Aristolochic Acids analysis, Butterflies chemistry, Medicine, Traditional
- Abstract
"Chiniy-tref" (CT) is a traditional preparation used in folk medicine in Martinique Island (French West Indies) that is nowadays mainly taken orally to prevent or act against any "manifestation of evil". CT is easily prepared at home by macerating larvae of the endemic swallowtail Battus polydamas (ssp.) cebriones (Dalman, 1823), sometimes accompanied by a leaf of its host-plant Aristolochia trilobata L., in commercial rum. We have previously reported the detection of nephrotoxic and carcinogenic aristolochic acids (AAs) I and II in CT, leading the Regional Health Agency (ARS) of Martinique to issue an alert regarding the potential risks associated with its consumption in 2015. In order to complete the toxicity risk assessment for oral consumption of CT, a full qualitative analysis of AAs and their analogues (AAAs) was performed, as well as a quantitative determination of the major AAs, namely AAs I and II. The phytochemical profiling of AAAs present in CT, that also corresponds to that of B. polydamas cebriones larvae feeding on A. trilobata, has been established for the first time by ultra-high performance liquid chromatography/electrospray ionization quadrupole time of-flight tandem mass spectrometry. AAs I and II were quantified in a small panel of tinctures by using a validated UHPLC/UV method, allowing us to estimate the probable daily intakes of these toxins by CT consumers. The results proved the existence of a real risk of renal toxicity and carcinogenicity associated with the chronic oral consumption of CT in Martinique, and more generally of similar "snake bottles" throughout the Caribbean., (Copyright © 2019 Elsevier Ltd. All rights reserved.)
- Published
- 2019
- Full Text
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9. Elderly Latino community members make an educational video: an academic-community collaboration to promote memory evaluations.
- Author
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Neugroschl J, Sewell MC, Umpierre M, Rodriguez R, Meyers L, Kranes S, Aldrete C, Collazo A, Valois L, and Sano M
- Abstract
Objectives: To develop an educational video to reach elderly Latinos in order to improve understanding and encourage evaluation of cognitive changes by 1) using focus groups to identify dementia knowledge gaps, health communication preferences and trusted advisors for health concerns; 2) collaborating with elderly Latino community members to create a video; and 3) collecting survey data regarding community response to the video., Design: Grounded theory qualitative approach using focus groups; collaborative community based model to create the video and anonymous survey at community screenings., Setting: Community senior centers in East Harlem, New York., Participants: A team of low-income mono and bilingual elderly Latino community residents, researchers, clinicians, and a film professional., Measurements: Thematic analysis of focus group transcripts; three item survey., Results: A collaboratively produced video and initial assessment in 49 Latino elders that indicated the video had a positive effect on interest in obtaining a brief memory screening at outreach events (71%)., Conclusions: The project demonstrates the feasibility of this interdisciplinary partnership to create a culturally and linguistically sensitive video to promote service use concerning memory loss and cognitive evaluations among elderly Latinos. Initial survey results suggested a positive response and an increase in interest in memory screening.
- Published
- 2019
- Full Text
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10. Severity of manchineel fruit (Hippomane mancinella) poisoning: A retrospective case series of 97 patients from French Poison Control Centers.
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Boucaud-Maitre D, Cachet X, Bouzidi C, Riffault-Valois L, Dupuy C, Garnier R, and Langrand J
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- Adolescent, Adult, Aged, Female, Hippomane chemistry, Humans, Male, Middle Aged, Physostigmine analysis, Plant Poisoning diagnosis, Poison Control Centers, Retrospective Studies, Young Adult, Fruit poisoning, Hippomane poisoning, Plant Poisoning etiology
- Abstract
In this retrospective series of 97 cases of manchineel fruit ingestion reported to French Poison Control Centers between 2009 and 2017, we investigated cases of poisoning due to manchineel fruit (from the Hippomane mancinella tree). This fruit is known to be responsible for oropharyngeal and gastrointestinal tract lesions and possibly hypotension and bradycardia (previously attributed to the presence of physostigmine). The most commonly observed clinical signs were oropharyngeal pain, abdominal pain, diarrhea and oropharyngeal irritation. No major gastrointestinal tract lesions were observed in the five cases in which upper gastrointestinal (GI) endoscopy was performed. One case of laryngeal edema and one case of bradycardia were observed, but analysis of the harvested fruits did not confirm the presence of physostigmine. Ingestion of manchineel fruit can cause mild abdominal pain and digestive irritation, requiring medical attention. Rarely, when several fruits have been ingested, severe oropharyngeal injury or hemodynamic disorders may require otorhinolaryngological consultation or cardiac monitoring for several hours, respectively., (Copyright © 2019 Elsevier Ltd. All rights reserved.)
- Published
- 2019
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11. Clerodane furanoditerpenoids as the probable cause of toxic hepatitis induced by Tinospora crispa.
- Author
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Cachet X, Langrand J, Riffault-Valois L, Bouzidi C, Colas C, Dugay A, Michel S, and Boucaud-Maitre D
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- Chemical and Drug Induced Liver Injury blood, Chemical and Drug Induced Liver Injury diagnosis, Humans, Liver drug effects, Liver metabolism, Liver Function Tests, Male, Middle Aged, Plant Stems chemistry, Plant Stems toxicity, Tinospora chemistry, Chemical and Drug Induced Liver Injury etiology, Diterpenes, Clerodane toxicity, Plant Extracts adverse effects, Tinospora toxicity
- Abstract
Tinospora crispa is a popular traditional herbal plant commonly used throughout the world for treatment of various diseases, in particular type 2 diabetes mellitus. We report here a new case of toxic hepatitis in a 57-year old male patient in the French West Indies following the consumption of two aqueous extracts of fresh Tinospora crispa stems. It thus differs from two previously reported cases that concerned the chronic intake of powdered dry stems delivered in solid oral dosage forms (i.e. pellets and tablets). Liquid Chromatography-Diode Array Detection-Mass Spectrometry (LC/DAD/MS) analyses were performed on an aqueous extract of the offending sample that mimics the swallowed preparation. They revealed the presence of species-specific molecular marker borapetoside C (1) and thus enabled an unambiguous phytochemical identification. The exploration of tandem MS/MS data obtained by ultra-high performance liquid chromatography/electrospray ionization quadrupole time-of-flight mass spectrometry (UHPLC-ESI-QTOF-HRMS) allowed the identification of 17 additional cis-clerodane-type furanoditerpenoid lactones, analogues of 1. These results support the hypothesis that the mechanisms underlying hepatotoxicity of Tinospora crispa are the same as those encountered with furanoditerpenoids-containing plants such as Teucrium chamaedrys or Dioscorea bulbifera. In the context of type 2 diabetes treatment, we recommend that Tinospora crispa intake should be more closely monitored for signs of hepatotoxicity.
- Published
- 2018
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12. The transcription factor MEF2A plays a key role in the differentiation/maturation of rat neural stem cells into neurons.
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Zhu B, Carmichael RE, Solabre Valois L, Wilkinson KA, and Henley JM
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- Animals, Cells, Cultured, Gene Knockdown Techniques, Rats, Wistar, Cell Differentiation, MEF2 Transcription Factors metabolism, Neural Stem Cells cytology, Neural Stem Cells metabolism, Neurons cytology, Neurons metabolism
- Abstract
Neural stem cells (NSCs) are self-renewing multipotent stem cells that can be proliferated in vitro and differentiated into neuronal and/or glial lineages, making them an ideal model to study the processes involved in neuronal differentiation. Here we have used NSCs to investigate the role of the transcription factor MEF2A in neuronal differentiation and development in vitro. We show that although MEF2A is present in undifferentiated NSCs, following differentiation it is expressed at significantly higher levels in a subset of neuronal compared to non-neuronal cells. Furthermore, shRNA-mediated knockdown of MEF2A reduces the number of NSC-derived neurons compared to non-neuronal cells after differentiation. Together, these data indicate that MEF2A participates in neuronal differentiation/maturation from NSCs., (Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2018
- Full Text
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13. Characteristics of Dysphagia in Infants with Microcephaly Caused by Congenital Zika Virus Infection, Brazil, 2015.
- Author
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Leal MC, van der Linden V, Bezerra TP, de Valois L, Borges ACG, Antunes MMC, Brandt KG, Moura CX, Rodrigues LC, and Ximenes CR
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- Brazil epidemiology, Deglutition Disorders pathology, Female, Humans, Infant, Microcephaly epidemiology, Pregnancy, Pregnancy Complications, Infectious epidemiology, Zika Virus Infection epidemiology, Deglutition Disorders etiology, Microcephaly complications, Microcephaly virology, Pregnancy Complications, Infectious virology, Zika Virus Infection complications
- Abstract
We summarize the characteristics of dysphagia in 9 infants in Brazil with microcephaly caused by congenital Zika virus infection. The Schedule for Oral Motor Assessment, fiberoptic endoscopic evaluation of swallowing, and the videofluoroscopic swallowing study were used as noninstrumental and instrumental assessments. All infants had a degree of neurologic damage and showed abnormalities in the oral phase. Of the 9 infants, 8 lacked oral and upper respiratory tract sensitivity, leading to delays in initiation of the pharyngeal phase of swallowing. Those delays, combined with marked oral dysfunction, increased the risk for aspiration of food, particularly liquid foods. Dysphagia resulting from congenital Zika virus syndrome microcephaly can develop in infants >3 months of age and is severe.
- Published
- 2017
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14. Molecular Fingerprint Comparison of Closely Related Rose Varieties based on UHPLC-HRMS Analysis and Chemometrics.
- Author
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Riffault-Valois L, Blanchot L, Colas C, Destandau E, Pasquier L, André P, and Elfakir C
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- Metabolomics, Multivariate Analysis, Reproducibility of Results, Chromatography, High Pressure Liquid methods, Rosa chemistry, Spectrometry, Mass, Electrospray Ionization methods
- Abstract
Introduction: The "Jardin de Granville" modern rose variety not only combines the morphological properties of its two parental cultivars, but also possesses better agronomic characteristics (abundant blooms, strong growth and vitality, high resistance to common rose diseases). In addition, it shows remarkable biological properties such as a high ability to decrease inflammatory and oxidative stress on skin cells. That is why Parfums Christian Dior selected this rose variety to be an active ingredient in luxury cosmetics., Objectives: To identify the characteristic molecular signature of "Jardin de Granville" compared with its parents "Annapurna" and "John Clare", by the mean of a non-targeted metabolomic comparison., Material and Methods: Wood, flower and leaf hydro-alcoholic extracts were analysed by UHPLC-ESI-HRMS. The fingerprints were then submitted to unsupervised multivariate analyses involving principal component analysis (PCA) and hierarchical ascendant classification (HAC). Analysis of variance (ANOVA) was finally performed to highlight the significant differences in each group of organs., Results: The extracts were composed of phenolic compounds such as hydrolysable and condensed tannins and flavonol derivatives. Three groups of extracts were clustered as a function of the variety. The compounds overexpressed in "Jardin de Granville" variety were highlighted thanks to ANOVA test. Flower was the most discriminative organ with 15 overexpressed molecules. Auto MS/MS analyses led to their tentative identifications., Conclusion: The non-targeted metabolomic approach revealed the importance of tannins to discriminate close rose varieties. The overexpressed hydrolysable tannins characteristic of "Jardin de Granville" can be responsible for the antioxidant and anti-inflammatory properties of the rose cosmetic ingredients. Copyright © 2016 John Wiley & Sons, Ltd., (Copyright © 2016 John Wiley & Sons, Ltd.)
- Published
- 2017
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15. Collaborative transdisciplinary team approach for dementia care.
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Galvin JE, Valois L, and Zweig Y
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- Aged, Aged, 80 and over, Caregivers, Female, Humans, Male, Quality of Life, Alzheimer Disease nursing, Cooperative Behavior, Patient Care Planning
- Abstract
Alzheimer's disease (AD) has high economic impact and places significant burden on patients, caregivers, providers and healthcare delivery systems, fostering the need for an evaluation of alternative approaches to healthcare delivery for dementia. Collaborative care models are team-based, multicomponent interventions that provide a pragmatic strategy to deliver integrated healthcare to patients and families across a wide range of populations and clinical settings. Healthcare reform and national plans for AD goals to integrate quality care, health promotion and preventive services, and reduce the impact of disease on patients and families reinforcing the need for a system-level evaluation of how to best meet the needs of patients and families. We review collaborative care models for AD and offer evidence for improved patient- and family-centered outcomes, quality indicators of care and potential cost savings.
- Published
- 2014
- Full Text
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16. Characteristics of students recruited in different types of medical schools.
- Author
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Maheux B, Béland F, Pineault R, Rivest P, and Valois L
- Subjects
- Female, Humans, Male, Michigan, Educational Measurement, School Admission Criteria, Schools, Medical, Students, Medical psychology
- Published
- 1986
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