43 research outputs found
Mise au point de la quantification dâun marqueur prĂ©coce de stress cellulaire chez les larves aquatiques de Cloeon dipterum (Ephemeroptera, Baetidae) collectĂ©es en rĂ©gion MĂ©diterranĂ©enne
National audienceThe aim of this study is to calibrate a biomarker of cellular stress, the heat shock protein (HSP70) induction, in aquatic invertebrates collected in a little Mediterranean run-off, as a tool for early ecological risk assessment. Larvae of the Ephemeroptera Cloeon dipterum (L., 1761), present all over the year and in a suitable amount, are chosen as biological model. The development of the biomarker quantification allows choosing the stage 5 and older larvae for this calibration. As the larvae are obtained in absence of natural thermal stress and from a run-off where sediment pollutant concentrations do not exceed the threshold above which adverse effects frequently occurred, the « Consensus-based PEC » (Probable Effect Concentration) (Mac Donald et al., 2000), the measured HSP70 concentrations reflect a basal level.Lâobjectif de cette Ă©tude est de calibrer un biomarqueur de stress cellulaire, lâinduction des protĂ©ines de choc thermique HSP70, chez des invertĂ©brĂ©s aquatiques prĂ©levĂ©s dans une roubine mĂ©diterranĂ©enne, pour une utilisation comme outil de diagnostic prĂ©coce du risque Ă©cologique. Les premiers prĂ©lĂšvements permettent de retenir les larves de lâĂ©phĂ©mĂ©roptĂšre Cloeon dipterum (L., 1761) comme modĂšle dâĂ©tude car elles sont les seules Ă y ĂȘtre prĂ©sentes toute lâannĂ©e et en quantitĂ© suffisante. La mise au point de la quantification du biomarqueur permet de sĂ©lectionner les larves de stade 5 et au-delĂ pour cette calibration. Les taux de HSP70 mesurĂ©s correspondent Ă des concentrations basales car obtenues chez des larves en absence de stress thermique naturel et dans un milieu oĂč les polluants ne dĂ©passent pas le « PEC » (Probable Effect Concentration), seuil au dessus duquel il est probable dâobserver des effets toxiques (Mac Donald et al., 2000)
Remote Radical Trifluoromethylation: A Unified Approach to the Selective Synthesis of Îł-Trifluoromethyl α,ÎČ-Unsaturated Carbonyl Compounds
International audienc
Organic Pollution and Genotoxicity of Sediments of the Palun Marshes (Berre Lagoon, France)
International audienceThe impact of industrial, rural, and urban activities on two runnels (B1, B2, and B3 from Beausset runnel and V1 and V2 from Vallat du Ceinturon runnel) located in the Palun marshes (Berre lagoon, France) was evaluated by analyzing 16 polycyclic aromatic hydrocarbons (PAHs), 1ânitropyrene (1âNP), 1âaminopyrene (1âAP), and six pesticides in sediment samples. The mutagenicity was assessed with the Salmonella mutagenicity test using tester strains TA98+S9 Mix and YG1041 ± S9 Mix. The clastogenicity was evaluated with the micronucleus assay on Chinese Ovarian cells ± S9 Mix. A gradient of PAHs concentrations was observed from B1 (3359 ÎŒg kg â1 dry weight [dw]), close to industrial zones, to V2 (497 ÎŒg kg â1 dw), away from the source of pollution. Similar gradient was noted for 1âAP (from B1: 11.8 ÎŒg kg â1 dw to V2: 0.6 ÎŒg kg â1 dw). However, this trend was not observed in 1âNP concentrations (concentrations ranged from 1.2 ÎŒg kg â1 dw [V1] to 0.4 ÎŒg kg â1 dw [B1]). Pesticides were detected in all samples. Diazinon and dieldrin were found in high concentrations in B1 extracts (74.5 and 39.9 ÎŒg.kg â1 dw, respectively). All the sediments except V2 were mutagenic with strain TA98+S9 Mix. The mutagenicity was linked to the presence of PAHs (V1), nitroarenes (B1 and B3) and aromatic amines (B2). All sediments were clastogenic with and without S9 Mix except V1 extract, which was negative without S9 Mix. Overall, the two runnels in the Palun marshes were found to be polluted by many organic compounds that originate from direct human activities and pose a significant genotoxic risk
Outils décisionnels dans la gestion des pollutions accidentelles des cours d'eau : vers des solutions écologiquement durables
National audienceIndustries regularly interface with natural environment. The natural environment is often impacted when accidental industrial pollution occurs. Classical procedure makes use of physico-chemical analyses to state the pollution of the environment. However, diagnosis on the living is often neglected in this inventory. The authors suggest an approach adapted to rivers to identify the impacts on the living. This approach may be a decisional tool for field operationals and a first step towards rehabilitation or ecological restoration of environment.L'interface milieu naturel-industrie est une constante dans l'occupation des sols. Lorsqu'un accident d'origine industrielle survient, ce milieu naturel est souvent largement impacté. Les procédures qui se mettent en place font appel à des analyses physico-chimiques pour faire l'état de la pollution du milieu, mais le diagnostic sur le vivant est souvent négligé. Les auteurs proposent une démarche adaptée aux cours d'eau pour le diagnostic des impacts sur le vivant, qui peut s'avérer un outil décisionnel pour les acteurs de terrain en vue d'une réhabilitation ou d'une restauration écologique du milieu
Aminoimidazo[1,2-a]pyridines: regioselective synthesis of substituted imidazonaphthyridines, azacarbolines and cyclazines
International audienc
Variable behavior of iPSCs derived from CML patients for response to TKI and hematopoietic differentiation.
Chronic myeloid leukemia disease (CML) found effective therapy by treating patients with tyrosine kinase inhibitors (TKI), which suppress the BCR-ABL1 oncogene activity. However, the majority of patients achieving remission with TKI still have molecular evidences of disease persistence. Various mechanisms have been proposed to explain the disease persistence and recurrence. One of the hypotheses is that the primitive leukemic stem cells (LSCs) can survive in the presence of TKI. Understanding the mechanisms leading to TKI resistance of the LSCs in CML is a critical issue but is limited by availability of cells from patients. We generated induced pluripotent stem cells (iPSCs) derived from CD34âș blood cells isolated from CML patients (CML-iPSCs) as a model for studying LSCs survival in the presence of TKI and the mechanisms supporting TKI resistance. Interestingly, CML-iPSCs resisted to TKI treatment and their survival did not depend on BCR-ABL1, as for primitive LSCs. Induction of hematopoietic differentiation of CML-iPSC clones was reduced compared to normal clones. Hematopoietic progenitors obtained from iPSCs partially recovered TKI sensitivity. Notably, different CML-iPSCs obtained from the same CML patients were heterogeneous, in terms of BCR-ABL1 level and proliferation. Thus, several clones of CML-iPSCs are a powerful model to decipher all the mechanisms leading to LSC survival following TKI therapy and are a promising tool for testing new therapeutic agents
Ăthique et Ă©ducation
L'entrĂ©e dans le XXIe siĂšcle a recentrĂ© le systĂšme Ă©ducatif français sur des prĂ©occupations Ă©thiques. Le contexte contraint en effet l'Ă©cole Ă se poser certaines questions allant de l'Ă©thique professionnelle Ă l'Ă©ducation morale des Ă©lĂšves. Le philosophe Eirick Prairat fut l'un des premiers Ă nous alerter sur la nĂ©cessaire actualitĂ© de ces interrogations. De l'Ă©volution des pratiques rĂ©glementaires de sanction Ă la reprise du chantier sur l'autoritĂ© Ă©ducative, Prairat s'est trouvĂ© au cĆur des grands enjeux qui agitent la rĂ©flexion sur l'Ă©cole de la RĂ©publique. C'est avec le prestige que lui confĂšre son titre de membre de l'Institut universitaire de France qu'il s'adresse aux acteurs de l'enseignement depuis plusieurs annĂ©es. Cet ouvrage prĂ©sente une Ă©tude des thĂšses principales de Prairat, par ceux qui le lisent. Une sĂ©rie de chapitres rĂ©partis en quatre grandes parties thĂ©matiques sont ici regroupĂ©s, afin d'accompagner ceux qui souhaitent entrer dans une philosophie qui entend se confronter aux questions vives
Amendements sur les articles du titre II du projet de décret sur la constitution civile du clergé, lors de la séance du 14 juin 1790
Saint-Esteven Jean-Louis-Xavier de, SieyÚs Emmanuel-Joseph, Bouche Charles-François, Gouttes Jean-Louis, Martineau Louis-Simon, Grégoire Baptiste Henri, Abbé, Prieur (de la Marne), Dumouchel Jean-Baptiste, Sillery Charles Alexis Brulart, marquis de, Moreau Etienne-Vincent, Mougins de Roquefort Antoine-Boniface, Fréteau de Saint-Just Emmanuel. Amendements sur les articles du titre II du projet de décret sur la constitution civile du clergé, lors de la séance du 14 juin 1790. In: Archives Parlementaires de 1787 à 1860 - PremiÚre série (1787-1799) Tome XVI - Du 31 mai au 8 juillet 1790. Paris : Librairie Administrative P. Dupont, 1883. pp. 215-216