Carbon nanotubes induce inflammation but decrease the production of reactive oxygen species in lung

With the rapid spread of carbon nanotubes (CNTs) applications, the respiratory toxicity of these compounds has attracted the attention of many scientists. Several studies have reported that after lung administration, CNTs could induce granuloma, fibrosis, or inflammation. By comparison with the mechanisms involved with other toxic particles such as asbestos, this effect could be attributed to an increase of oxidative stress. The aim of the present work was to test this hypothesis in vivo. Mice were intranasally instilled with 1.5 mg/kg of double walled carbon nanotubes (DWCNTs). Six, 24, or 48 h after administration, inflammation and localisation of DWCNTs in lungs were microscopically observed. Local oxidative perturbations were investigated using ESR spin trapping experiments, and systemic inflammation was assessed by measuring the plasma concentration of cytokines TNF-α, IL-1α, IL-1β, IL-6, IGF-1, Leptin, G-CSF, and VEGF. Examination of lungs and the elevation of proinflammatory cytokines in the plasma (Leptin and IL-6 at 6 h) confirmed the induction of an inflammatory reaction. This inflammatory reaction was accompanied by a decrease in the local oxidative stress. This effect could be attributed to the scavenger capability of pure CNTs

Chronic Electromagnetic Exposure at Occupational Safety Level Does Not Affect the Metabolic Profile nor Cornea Healing after LASIK Surgery

LASIK eye surgery has become a very common practice for myopic people, especially those in the military. Sometimes undertaken by people who need to keep a specific medical aptitude, this surgery could be performed in secret from the hierarchy and from the institute medical staff. However, even though the eyes have been previously described as one of the most sensitive organs to electromagnetic fields in the human body, no data exist on the potential deleterious effects of electromagnetic fields on the healing eye. The consequences of chronic long-lasting radar exposures at power density, in accordance with the occupational safety standards (9.71 GHz, 50 W/m2), were investigated on cornea healing. The metabolic and clinical statuses after experimental LASIK keratotomy were assessed on the different eye segments in a New Zealand rabbit model. The analysis methods were performed after 5 months of exposure (1 hour/day, 3 times/week). Neither clinical or histological examinations, nor experimental data, such as light scattering, 1H-NMR HRMAS metabolomics, 13C-NMR spectra of lipidic extracts, and antioxidant status, evidenced significant modifications. It was concluded that withdrawing the medical aptitude of people working in electromagnetic field environments (i.e., radar operators in the navy) after eye surgery was not justified

Lexis, Journal in English Lexicology, issue 23, The Phonology-Lexicology interface

This issue of Lexis aims to explore some of the ways in which the strong, even consubstantial, link between lexicology and phonology manifests itself

Introduction: The Phonology-Lexicon Interface

International audienc

À la frontière onde-lumière

Grâce aux technologies THz (térahertz), il est d’ores et déjà possible de fabriquer des systèmes d’imagerie et il est indéniable que l’arrivée prochaine de sources facilement transportables va révolutionner les techniques de détection à distance. Dans le domaine de la santé, l’apport de cette technologie conduit à un degré de finesse inégalé jusqu’à maintenant dans l’analyse de molécules. Les applications biologiques et médicales, notamment en dentisterie et en dermatologie, sont en cours de développement. Cependant, il ne faut pas pour autant négliger l’étude des répercussions sanitaires des ondes THz ; un champ d’investigation est ainsi ouvert et les premiers résultats dans ce domaine sont maintenant disponibles

Study of Alkylglycerol Containing Shark Liver Oil: A Physico Chemical Support for Biological Effect?

Shark liver oil (SLO), is used in natural medicine as immunity stimulant, cardiovascular protector and anti ageing reagent. These properties were related with the high amounts of alkylglycerols (22%) obtained from Greenland shark liver. After a control of the mean SLO composition by NMR and MS, surface and membrane interactions and antioxidant properties were investigated using NMR, ESR and ST measurements and the in vitro consequences on erythrocytes and cells were studied. An estimation of the composition of this extract was performed. Moreover, SLO was found not haemolytic (A concentration inducing 50% haemolysis, HC 50 could not be reached) and superficial tension measurements revealed slight tension active properties. The 31 P and 2 H-NMR and ESR studies of phospholipid dispersions (dimyristoyl phosphatidyl cholin, DMPC) in the presence of SLO showed a significant increase in membrane fluidity at low temperature (below phase transition temperature) predominantly observed at the surface level. The anti oxidant activity was also confirmed, similar as that observed for vitamin E

2,3-Diarylimidazo[1,2-a]pyridines as potential inhibitors of UV-induced keratinocytes apoptosis: synthesis, pharmacological properties and interactions with model membranes and oligonucleotides by NMR.

International audienceFour 2,3-diarylimidazo[1,2-a]pyridines (I, 1a-c) were synthesized as inhibitors of UV-induced apoptosis and showed quite different properties. First, only the pyridinyl derivative I showed protection in molt cells. From the supposed intracellular target, phospholipid membrane models were studied by (1)H, (2)H and (31)P NMR spectroscopy. All these molecules can incorporate the membrane bilayer of small unilamellar vesicles of lecithin (SUV). However, I is clearly closed to the external polar head of the lipids, and is relatively mobile in the layer. Conversely, the other molecules are strongly immobilized in the deep part of the external layer. (31)P solid-state NMR spectra recorded on phospholipid dispersions (multilayers vesicles (MLV)) completely excluded any detergent effect or any modification of temperature transition. The only structural or dynamic effect observed was a homogeneous, but limited, reduction in the chemical shift anisotropy in the presence of I, in agreement with its superficial location. (2)H NMR experiment performed on the same model using perdeuterated phospholipids showed no significant fluidity reduction at the level of terminal CD(3) groups in the presence of 1a-c, according to their deep location. Finally, their interactions with synthetic oligonucleotide, d(CGATCG)(2) was studied showing non specific interactions of 1a on the external GC pair, while no interaction was observed with the other derivatives