8 research outputs found
L'Ă©cole dehors
National audienceCe chapitre présente plusieurs initiatives d'école au dehors ainsi que quelques fondements
Ătude rĂ©trospective sur lâintĂ©rĂȘt de lâimagerie 3D dans lâĂ©valuation de la suture mĂ©sio-palatine
LâĂ©tude de la suture mĂ©so-palatine (SMP) prĂ©sente un intĂ©rĂȘt majeur dans le traitement orthodontique des patients prĂ©sentant une endomaxillie. Sa classification selon Angieleri et al. et grĂące Ă lâimagerie en trois dimensions pourrait nous aider pour choisir la bonne technique de disjonction : chirurgicale ou orthopĂ©dique. Nous avons rĂ©alisĂ© une Ă©tude rĂ©trospective bicentrique avec une lecture en double aveugle sur des images de cone-beam obtenues entre 2017 et 2022. Lâinclusion de 57 patients de 11 Ă 15 ans nous a permis de montrer que la SMP a plus tendance Ă ĂȘtre fermĂ©e chez les 14 15 ans que chez les 11 13 ans. Cependant des cas avec une SMP ouverte sont retrouvĂ©s dans toutes les tranches dâĂąge. Le sexe ne semble pas ĂȘtre un facteur dĂ©terminant sur la SMP.
La SMP étant parfois ouverte tardivement un cone-beam avant disjonction permettrait de choisir de maniÚre individuelle la technique la plus appropriée
Multiscattering-enhanced absorbance to enable the sensitive analysis of extremely diluted biological samples: Determination of oxidative potential in exhaled air
Direct determination of the oxidative potential in exhaled air (OPEA) as a biological indicator of the redox balance status in airways requires an extremely sensitive sensing approach to counterbalance the high dilution of the exhaled air matrix. In opposite to standard colorimetric assays based on Beer-Lambert Law, the use of simple multiscattering-enhanced absorbance (MEA) strategy results in an improved photonic sensing system. Based on this strategy and using the ferrous-xylenol orange assay, analytical performances allowing the detection of 3 âpmol of H2O2 could be obtained. The comparative analysis of photometric configurations â standard vs MEA â highlights the large absorbance gain obtained for tiny H2O2 amounts â from 0 to 30 âpmol â whereas similar sensing trends are observed at higher concentration range. The automated introduction of exhaled air sample into the reaction compartment via needle-impinger coupled with the MEA-based photonic cell enables ultrasensitive determination of OPEA in short time (<5 âmin). A pilot study conducted on healthy subjects (n â= â22) and chronic obstructive pulmonary disease (COPD) patients (n â= â23) volunteers shows a significant increase of the OPEA for COPD versus controls and strong negative correlation between OPEA and spirometry parameters (Tiffeneau index: FEV1/FVC) for ex-/non-smokers. Application perspectives to assess inflammatory episodes in obstructive lung diseases are thus made possible using this sensing approach
Tuning of the enzyme ratio in a neutral redox convergent cascade: A key approach for an efficient oneâpot/twoâstep biocatalytic wholeâcell system
International audienceThe efficiency of a versatile in vivo cascade involving a promiscuous alcohol dehydrogenase, obtained from a biodiversity search, and a Baeyer-Villiger monooxygenase was enhanced by the independent control of the production level of each enzyme to produce -caprolactone and 3,4dihydrocoumarin. This goal was achieved by adjusting the copy number per cell of E. coli plasmids. We started from the observation that this number generally correlates with the amount of produced enzyme and demonstrated that an in vivo multi-enzymatic system can be improved by the judicious choice of plasmid, the lower activity of the enzyme that drives the limiting step being counterbalanced by a higher concentration. Using a preconception-free approach to the choice of the plasmid type, we observed positive and negative synergetic effects, sometimes unexpected and depending on the enzyme and plasmid combinations. Experimental optimization of the culture conditions allowed us to obtain a complete conversion of cyclohexanol (16 mM) and 1-indanol (7.5 mM) at a 0.5-L scale. The yield for the conversion of cyclohexanol was 80% (0.7 g -caprolactone, for a productivity of 244 mg. L-1 .h-1) and that for 1-indanol 60% (0.3 g 3,4-dihydrocoumarin, for a productivity of 140 mg. L-1 .h-1)
The environmental carcinogen benzo[a]pyrene induces a Warburg-like metabolic reprogramming dependent on NHE1 and associated with cell survival
International audienceCancer cells display alterations in many cellular processes. One core hallmark of cancer is the Warburg effect which is a glycolytic reprogramming that allows cells to survive and proliferate. Although the contributions of environmental contaminants to cancer development are widely accepted, the underlying mechanisms have to be clarified. Benzo[a]pyrene (B[a]P), the prototype of polycyclic aromatic hydrocarbons, exhibits genotoxic and carcinogenic effects, and it is a human carcinogen according to the International Agency for Research on Cancer. In addition to triggering apoptotic signals, B[a]P may induce survival signals, both of which are likely to be involved in cancer promotion. We previously suggested that B[a]P-induced mitochondrial dysfunctions, especially membrane hyperpolarization, might trigger cell survival signaling in rat hepatic epithelial F258 cells. Here, we further characterized these dysfunctions by focusing on energy metabolism. We found that B[a]P promoted a metabolic reprogramming. Cell respiration decreased and lactate production increased. These changes were associated with alterations in the tricarboxylic acid cycle which likely involve a dysfunction of the mitochondrial complex II. The glycolytic shift relied on activation of the Na+/H+ exchanger 1 (NHE1) and appeared to be a key feature in B[a]P-induced cell survival related to changes in cell phenotype (epithelial-to-mesenchymal transition and cell migration)
Repérage des expositions professionnelles au cours des hémopathies lymphoïdes : programme Rhelypro
International audienceIntroductionLes lymphomes non hodgkiniens (LNH), les myĂ©lomes multiples (MM) et les leucĂ©mies lymphoĂŻdes chroniques (LLC), hĂ©mopathies malignes dĂ©rivĂ©es de la lignĂ©e lymphoĂŻde, sont des maladies frĂ©quentes et dont lâincidence est en augmentation. Ces affections sont possiblement en rapport avec une exposition environnementale et/ou professionnelle, avec de nombreux agents Ă©tiologiques suspectĂ©s.Le programme Rhelypro, soutenu par lâAnses, a pour but le repĂ©rage des expositions professionnelles aux cancĂ©rogĂšnes considĂ©rĂ©s comme certains ou probables aprĂšs analyse des donnĂ©es de la littĂ©rature chez tous les patients ayant un diagnostic incident de LNH, MM, LLC, Ă partir dâun questionnaire spĂ©cifique mis en place pour ce programme.MĂ©thodeIl sâagit dâune Ă©tude multicentrique incluant 7 centres de consultation de pathologies professionnelles de CrĂ©teil, Paris - F.-Widal, Bordeaux, Caen, Lille, Toulouse, de juillet 2017 Ă avril 2019. Tous les cas incidents de LNH, MM et LLC, ont bĂ©nĂ©ficiĂ© dâun questionnaire de repĂ©rage Ă©laborĂ© collectivement par les Ă©quipes de pathologies professionnelles impliquĂ©es, et permettant de lister les principales situations dâexposition aux agents cancĂ©rogĂšnes probables ou certains du Centre international de recherche sur le cancer (CIRC) pour lesquels un excĂšs de LNH, MM ou LLC a Ă©tĂ© rapportĂ©. Un questionnaire professionnel classique Ă©tait ensuite utilisĂ©, suivie dâune expertise en pathologie professionnelle. LâacceptabilitĂ© du questionnaire par les patients, le nombre de sujets faisant lâobjet dâune proposition de dĂ©claration de maladie professionnelle et lâidentification du type de secteurs dâactivitĂ©s et de postes de travail concernĂ©s pour chaque nuisance ont Ă©tĂ© Ă©valuĂ©s.RĂ©sultatsLa population dâĂ©tude est constituĂ©e de 205 patients avec un Ăąge moyen de 60 ans. Les 3 nuisances les plus souvent retenues sont les solvants organiques (hors trichloroĂ©thylĂšne, benzĂšne et dichloromĂ©thane), le benzĂšne et les pesticides. Des expositions professionnelles ont Ă©tĂ© retenues pour 21 % des sujets dâaprĂšs lâexpertise finale et ont conduit Ă proposer une demande de reconnaissance de maladie professionnelle. La sensibilitĂ© du questionnaire de repĂ©rage Ă©tait de 92 % et sa spĂ©cificitĂ© de 83 % par rapport au questionnaire de pathologie professionnelle suivi dâexpertise.ConclusionLe questionnaire de repĂ©rage proposĂ© paraĂźt avoir des performances (sensibilitĂ©, spĂ©cificitĂ©) satisfaisantes, incitant Ă lâutiliser dans les services dâhĂ©matologie en routine pour les cas incidents de LNH. En cas de rĂ©ponse positive, une expertise complĂ©mentaire peut ĂȘtre proposĂ©e en pathologie professionnelle dans le cadre du RĂ©seau national de vigilance et de prĂ©vention des pathologies professionnelles