Biomonitoring of the genotoxic potential of aqueous extracts of soils and bottom ash resulting from municipal solid waste incineration, using the comet and micronucleus tests on amphibian (Xenopus laevis) larvae and bacterial assays (MutatoxR and Ames tests)

The management of contaminated soils and wastes is a matter of considerable human concern. The present study evaluates the genotoxic potential of aqueous extracts of two soils (leachates) and of bottom ash resulting from municipal solid waste incineration (MSWIBA percolate), using amphibian larvae (Xenopus laevis). Soil A was contaminated by residues of solvents and metals and Soil B by polycyclic aromatic hydrocarbons and metals. MSWIBA was predominantly contaminated by metals. Two genotoxic endpoints were analysed in circulating erythrocytes taken from larvae: clastogenic and/or aneugenic effects (micronucleus induction) after 12 days of exposure and DNA-strand-breaking potency (comet assay) after 1 and 12 days of exposure. In addition, in vitro bacterial assays (MutatoxR and Ames tests) were carried out and the results were compared with those of the amphibian test. Physicochemical analyses were also taken into account. Results obtained with the amphibians established the genotoxicity of the aqueous extracts and the comet assay revealed that they were genotoxic from the first day of exposure. The latter test could thus be considered as a genotoxicity-screening tool. Although genotoxicity persisted after 12 days’ exposure, DNA damage decreased overall between days 1 and 12 in the MSWIBA percolate, in contrast to the soil leachates. Bacterial tests detected genotoxicity only for the leachate of soil A (Mutatox). The results confirm the ecotoxicological relevance of the amphibian model and underscore the importance of bioassays, as a complement to physicochemical data, for risk evaluation

Labeling of human erythrocyte membrane proteins by photoactivatable radioiodinated phosphatidylcholine and phosphatidylserine A search for the aminophospholipid translocase

AbstractWe have synthesized radioiodinated photoactivatable phosphatidylcholine (125-N3-PC) and phosphatidylserine (125I-N3-PS). After incubation with red blood cells in the dark, the labeled PC could be extracted but not the corresponding PS molecule, indicating that the latter was transported by the aminophospholipid translocase, but not the former. When irradiated immediately after incorporation, N3-PS, but not N3-PC, partially blocked subsequent translocation of spin-labeled aminophospholipids. Analysis of probe distribution by SDSpolyacrylamide gel electrophoresis revealed that 125I-N3-PS labeled seven membrane bound components with molecular masses between 140 and 27 kDa: one (or several) of these components should correspond to the aminophospholipid translocase

La santé des seniors selon leur origine sociale et la longévité de leurs parents.

Les descendants des cadres dirigeants et professions intellectuelles ont-ils une meilleure santé que les descendants d’ouvriers ? Est-ce que la longévité des parents infl uence l’état de santé à l’âge adulte ? Ces deux questions interrogent l’existence d’inégalités des chances en santé. La première question a déjà fait l’objet de travaux de recherche : l’infl uence du milieu social d’origine résulterait à la fois d’un effet direct des conditions de vie dans l’enfance sur la santé à l’âge adulte et d’un effet indirect passant par l’infl uence du milieu d’origine sur le statut socioéconomique du descendant. La seconde, qui concerne une transmission de la santé entre les générations a été peu explorée. Cependant, une infl uence directe de l’état de santé des parents sur celui de leurs enfants devenus adultes peut être envisagée du fait non seulement d’un patrimoine génétique commun mais aussi de préférences similaires pour la santé et d’une reproduction des comportements liés à la santé. À partir des données de l’enquête Share, cette recherche étudie, pour la première fois en France, le rôle de la profession des deux parents et de leur état de santé, sur celui de leurs descendants à l’âge adulte, en contrôlant pour les caractéristiques socioéconomiques de ceux-ci. La comparaison des distributions de santé des seniors selon le milieu social d’origine et la longévité des ascendants directs témoignent de l’existence d’inégalités des chances en santé chez les seniors. Au-delà de son association avec la situation sociale actuelle de l’individu, l’état de santé à l’âge adulte est directement infl uencé par le statut socioéconomique de la mère, le statut socioéconomique du père ayant au contraire une infl uence indirecte passant par la détermination du statut socioéconomique de l’enfant. Une transmission intergénérationnelle de la santé est également observée : la longévité relative du père et en particulier son statut vital infl uence la santé à l’âge adulte.Intergenerational transmission; Economie de la santé; Seniors; Origine sociale; Statistiques;

Origine sociale et état de santé des parents : Quelle influence sur l’état de santé à l’âge adulte ?.

Parmi les facteurs explicatifs proposés pour expliquer les inégalités sociales de santé, la littérature épidémiologique a récemment mis en avant l’influence du milieu social d’origine sur l’état de santé à l’âge adulte, cette influence résultant à la fois d’un effet direct des conditions de vie dans l’enfance sur la santé (latency model) et d’un effet indirect passant par l’influence du milieu d’origine sur le statut socioéconomique de l’enfant (pathway model). Par ailleurs, on peut supposer une influence directe de l’état de santé des parents sur celui des enfants, s’expliquant non seulement par un patrimoine génétique commun mais aussi par une transmission des comportements liés à la santé. A partir d’une exploitation de l‘enquête SHARE, cette recherche propose d’explorer ces trois modèles, pour la première fois en France, en étudiant le rôle de la profession des deux parents et de leur état de santé, sur l’état de santé d’un individu à l’âge adulte, contrôlé par son statut socioéconomique. Les résultats montrent que l’état de santé à l’âge adulte, au-delà de son association avec la situation sociale actuelle de l’individu, n’est pas indépendant de l’origine sociale ni de l’état de santé des parents. La santé à l’âge adulte semble être directement influencée par le statut socioéconomique de la mère et l’état de santé des deux parents, le statut socioéconomique du père ayant au contraire une influence indirecte passant par la détermination du statut socioéconomique de l’enfant. Ces résultats suggèrent ainsi l’existence en France d’une inégalité des chances en matière de santé.Egalités des chances; inégalités de santé; transmission intergénérationnelle; early life hypothesis;

Functional significance of genotoxicity in fish germ cells

The aquatic environment is becoming increasingly contaminated by pollutants having a genotoxic potential towards organisms and in particular in fish. Such genotoxins are prone to affect directly offspring or indirectly through the reproductive process. All this could influence recruitment rate and hence the population dynamics. However, assessment of the ecological risks associated with environmental genotoxic exposure is usually based on individual responses. Thus, there is a need for a better understanding of the long term and population level implications of genotoxic insults in fish. While low levels of DNA damage in somatic cells and oocytes can be efficiently repaired, mature sperm cells, i.e. spermatozoa, are susceptible to accumulate damage due to their lack of repair capacity. The present work aims to track the transfer of toxic effects across generations by studying the link between the level of DNA damage in fish sperm, and the rate of development abnormalities measured in the offspring after parental exposure to the model genotoxicant MMS. Three different fish species were chosen based either on their ecological importance or on their reproduction behavior, respectively brown trout (Salmo trutta), Arctic charr (Salvelinus alpinus) and threespine stickleback (Gasterosteus aculeatus). Results show a significant increase in sperm DNA damage measured with the comet assay in exposed organisms. This damage did not impact on fertilization success but led further to a significant increase in embryo abnormality rate at early embryonic and late larval stages, and further delayed growth in exposed group compared to the control

Ecotoxicological risk assessment linked to infilling quarries with treated dredged seaport sediments

International audienceThe dredged sediments of polluted seaports now raise complex management problems since it is no longer possible to discharge them into the sea. This results in the need to manage them on land, raising other types of technical, economic and environmental problems. Regarding the technical and economic dimensions, traditional waste treatment methods have proved to be poorly adapted, due to very high costs and low absorbable volumes. In this context, filling quarries in coastal areas with treated sediments could represent an interesting alternative for these materials. Nevertheless, for the environmental dimension, it is necessary to demonstrate that this possibility is harmless to inland ecosystems. Consequently, a specific ecotoxicological risk assessment methodology has been formulated and tested on three sediments taken from seaboards of France, in view to providing an operational and usable tool for the prior validation of any operation to fill quarries with treated seaport sediments. This method incorporates the formulation of a global conceptual model of the scenario studied and the definition of protocols for each of its steps: the characterisation of exposures (based on a simulation of sediment deposit), the characterisation of effects (via the study of sediments ecotoxicity), and the final ecotoxicological risk assessment performed as a calculation of a risk quotient. It includes the implementation in parallel of two types of complementary approach: the "substances" approach derived from the European methodology for assessing new substances placed on the market, and the "matrix" approach which is similar to methods developed in France to assess ecological risks in other domains (waste management, polluted site management, ...). The application of this dual approach to the three sediments tested led to conclude with reliability that the project to deposit sediments "1" and "2" presented a low risk for the peripheral aquatic ecosystems while sediment "3" presented a high risk

Protein 4.1B Contributes to the Organization of Peripheral Myelinated Axons

Neurons are characterized by extremely long axons. This exceptional cell shape is likely to depend on multiple factors including interactions between the cytoskeleton and membrane proteins. In many cell types, members of the protein 4.1 family play an important role in tethering the cortical actin-spectrin cytoskeleton to the plasma membrane. Protein 4.1B is localized in myelinated axons, enriched in paranodal and juxtaparanodal regions, and also all along the internodes, but not at nodes of Ranvier where are localized the voltage-dependent sodium channels responsible for action potential propagation. To shed light on the role of protein 4.1B in the general organization of myelinated peripheral axons, we studied 4.1B knockout mice. These mice displayed a mildly impaired gait and motility. Whereas nodes were unaffected, the distribution of Caspr/paranodin, which anchors 4.1B to the membrane, was disorganized in paranodal regions and its levels were decreased. In juxtaparanodes, the enrichment of Caspr2, which also interacts with 4.1B, and of the associated TAG-1 and Kv1.1, was absent in mutant mice, whereas their levels were unaltered. Ultrastructural abnormalities were observed both at paranodes and juxtaparanodes. Axon calibers were slightly diminished in phrenic nerves and preterminal motor axons were dysmorphic in skeletal muscle. βII spectrin enrichment was decreased along the axolemma. Electrophysiological recordings at 3 post-natal weeks showed the occurrence of spontaneous and evoked repetitive activity indicating neuronal hyperexcitability, without change in conduction velocity. Thus, our results show that in myelinated axons 4.1B contributes to the stabilization of membrane proteins at paranodes, to the clustering of juxtaparanodal proteins, and to the regulation of the internodal axon caliber

Synthesis of the metastable α-Al1.8Fe0.2O3 solid solution from precursors prepared by combustion

The aim of the paper is to synthesise α-Al1.8Fe0.2O3 solid solutions from precursors prepared by the nitrate/fuel combustion synthesis route, using either citric acid or urea, or a mixture of both as the fuel, and different fuel/nitrates ratios. In a first part, global reactions are proposed for each synthesis, which are useful to explain the differences in powder volume, morphology, crystallisation state and specific surface area reported in the second part of the study. In a third part, the powders were further calcined at 1100 °C in order to obtain the corundum form. A combination of Mössbauer spectroscopy, XRD and specific surface area measurements revealed that only the powders prepared with Φe = 2 are the desired monophased α-Al1.8Fe0.2O3 solid solutions

Constraints on anomalous QGC's in e+e−e^{+}e^{-} interactions from 183 to 209 GeV

The acoplanar photon pairs produced in the reaction e(+) e(-) - → vvyy are analysed in the 700 pb(-1) of data collected by the ALEPH detector at centre-of-mass energies between 183 and 209 GeV. No deviation from the Standard Model predictions is seen in any of the distributions examined. The resulting 95% C.L. limits set on anomalous QGCs, a(0)(Z), a(c)(Z), a(0)(W) and a(c)(W), are -0.012 lt a(0)(Z)/Lambda(2) lt +0.019 GeV-2, -0.041 lt a(c)(Z)/Lambda(2) lt +0.044 GeV-2, -0.060 lt a(0)(W)/Lambda(2) lt +0.055 GeV-2, -0.099 lt a(c)(W)/Lambda(2) lt +0.093 GeV-2, where Lambda is the energy scale of the new physics responsible for the anomalous couplings

Absolute mass lower limit for the lightest neutralino of the MSSM from e+e−e^{+}e^{-} data at s\sqrt{s} up to 209 GeV

Charginos and neutralinos are searched for in the data collected by the ALEPH experiment at LEP for centre-of-mass energies up to 209 GeV. The negative result of these searches is combined with those from searches for sleptons and Higgs bosons to derive an absolute lower limit of 43.1 GeV/c(2) on the mass of the lightest supersymmetric particle (LSP), assumed to be the,lightest neutralino. This limit is obtained in the framework of the MSSM with R-parity conservation and with gaugino and sfermion mass unification at the GUT scale and assuming no mixing in the stau sector. The LSP limit degrades only slightly to 42.4 GeV/c(2) if stau mixing is considered. Within the more constrained framework of minimal supergravity, the limit is 50 GeV/c(2)