Upstream Mediators of the Fas Apoptotic Transduction Pathway Are Defective in B-Chronic Lymphocytic Leukemia

International audienceData concerning the presence and the functionality of Fas receptor in malignant B-cells are controversial. We have analyzed Fas molecules on B-cells from patients with B-chronic lymphocytic leukemia (B-CLL) cells. We observed a large variability, both of percentage of Fas-positive cells and of intensity of Fas level. Fas triggering was inefficient in inducing apoptosis whatever the number of Fas-positive B-cells, the amount of Fas receptors. B-cells were also resistant to etoposide treatment, but able to undergo apoptosis after dexamethasone treatment. We suggest that the Fas apoptotic pathway is altered in B-CLL patients at the initial step(s) of apoptotic machinery

Mach-Zehnder interferometer based on femtosecond laser waveguide inscription

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Radiation-Response of Fiber Bragg Gratings at Low Temperatures

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No BCL-2 Protein over Expression but BCL-2/IgH Rearrangements in B Cells of Patients with Persistent Polyclonal B-Cell Lymphocytosis

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Ge- and Al-related point defects generated by gamma irradiation in nanostructured erbium-doped optical fiber preforms

International audienceErbium-doped amplifiers (EDFAs) are of special interest for space applications.In this environment, the ionizing radiations decrease the gain of these opticalamplifiers, due to the ionization of defects precursors, mainly linked to dopantsas Germanium (Ge), Aluminum (Al), or Phosphorus (P). The aim of this work isto study the influence of the Ge and Al relative concentration on the radiationresistance of different nanostructured fiber preforms, manufactured by ModifiedChemical Vapor Deposition (MCVD), in which various types of nanoparticles(Er@SiO2-NP, Al2O3-NP, and Er@Al2O3-NP) have been introduced in thesilica matrix. The radiation resistance of these fibers has been compared withthat of standard MCVD Er-doped preforms. All of them have been characterizedby optical absorption and Electronic Paramagnetic Resonance (EPR) spectroscopiesbefore and after irradiation with a total gamma dose of 5.9 kGy. EPRresults show that Al-related defects are not observed in fiber preforms with Geconcentrations higher than 4.4 wt%. We also demonstrated that NP technologycan limit the formation of Aluminum-Oxygen Hole Centers (AlOHCs), reducingthe Radiation-Induced Attenuation at the energy of interest for EDFAs