Validation d'une méthode qualitative d'estimation de l'influence de la météorologie sur le bruit

We first propose a simple method for helping the acoustician to estimate the effects of meteorological conditions on noise propagation, at least qualitatively. This method is based on a double-entry grid that only requires simple meteorological observations. We then compare the qualitative estimations given by the grid to the results of an outdoor experiment. Human evaluation of climatic conditions is shown to be satisfactory for a qualitative estimation of their effects on noise measurements

Beta-N-methylamino-L-alanine (BMAA) and isomers : distribution in different food web compartments of Thau lagoon, French Mediterranean Sea

The neurotoxin BMAA (beta-N-methylamino-L-alanine) and its isomer DAB (2,4-diaminobutyric acid) have been detected in seafood worldwide, including in Thau lagoon (French Mediterranean Sea). A cluster of amyotrophic lateral sclerosis (ALS), a neurodegenerative disease associated with BMAA, has also been observed in this region. Mussels, periphyton (i.e. biofilms attached to mussels) and plankton were sampled between July 2013 and October 2014, and analyzed using HILIC-MS/MS. BMAA, DAB and AEG (N-(2-aminoethyl)glycine) were found in almost all the samples of the lagoon. BMAA and DAB were present at 0.58 and 0.83, 2.6 and 33, 4.0 and 7.2 mu g g(-1) dry weight in plankton collected with nets, periphyton and mussels, respectively. Synechococcus sp., Ostreococcus tauri, Alexandrium catenella and eight species of diatoms were cultured and screened for BMAA and analogs. While Synechococcus sp., O. tauri and A. catenella did not produce BMAA under our culture conditions, four diatoms species contained both BMAA and DAB. Hence, diatoms may be a source of BMAA for mussels. Unlike other toxins produced by microalgae, BMAA and DAB were detected in significant amounts in tissues other than digestive glands in mussels

Aza-capped cyclodextrins for intra-cavity metal complexation

International audienceAza-capped, methylated cyclodextrins (CDs) were obtained in high yields by reacting the soft nitrogen nucleophile 2-nitrobenzenesulfonamide with either A, B-dimesylated CDs in basic media or their diol analogues under Mitsunobu reaction conditions followed by deprotection with thiophenol. A methyl pyridine substituent was grafted on the N atom of these secondary amines. When built on an alpha-CD scaffold, the resulting tertiary amine no longer undergoes nitrogen inversion at room temperature and behaves as a confining ligand, opening the way to intra-cavity metal complexation and promoting the formation of supramolecular helices

Cytomegalovirus prophylaxis with intravenous polyvalent immunoglobulin in high-risk renal transplant recipients.

International audienceCytomegalovirus (CMV) seronegative renal allograft recipients (R-), particularly those with a graft from a CMV-seropositive donor (D+), are at high risk for primary CMV infection. CMV resistance to antiviral oral therapy is an emerging problem in renal transplantation, prompting development of new prophylactic strategies. We retrospectively studied the 1-year posttransplantation incidence of CMV infection in high-risk renal transplant recipients, in whom polyvalent intravenous immunoglobulins (IVIg) were used as prophylaxis. Forty R- patients received immunoprophylaxis by polyvalent IVIg (0.25 g/kg weekly for 8 weeks, starting on the operative day). CMV serological tests remained negative in eight patients (20%). Eight patients (20%) had asymptomatic CMV infection while 24 (60%) developed CMV syndrome and were treated with gancyclovir (10 mg/kg/day intravenously for 3 weeks). None had CMV disease or opportunistic infection. Six patients (15%) had biopsy-proven acute rejection, which followed CMV syndrome in three cases. One-year renal allograft and patient survivals were 95% and 97.5%, respectively. Mean serum creatinine level was 124 +/- 33 micromol/L at 1 year. Clinical tolerance of IVIg was excellent, without any episode of acute renal failure. Polyvalent IVIg provides effective prophylaxis in renal transplant recipients at high risk for CMV infection and is associated with excellent 1-year allograft survival. Because of their immunomodulatory functions, IVIg may have a beneficial effect on the incidence of acute and chronic rejection and allograft survival. A randomized prospective study is required to evaluate long-term effects of CMV prophylaxis with polyvalent IVIg compared to antiviral agents in renal transplant recipients

The role of basophils as innate immune regulatory cells in allergy and immunotherapy

Basophils are circulating cells that are associated quite exclusively with allergy response and hypersensitivity reactions but their role in the immune network might be much more intriguing and complex than previously expected. The feasibility of testing their biology in vitro for allergy research and diagnosis, due fundamentally to their quite easy availability in the peripheral blood, made them the major source for assessing allergy in the laboratory assay, when yet many further cells such as mast cells and eosinophils are much more involved as effector cells in allergy than circulating basophils. Interestingly, basophil numbers change rarely in peripheral blood during an atopic response, while we might yet observe an increase in eosinophils and modification in the biology of mast cells in the tissue during an hypersensitivity response. Furthermore, the fact that basophils are very scanty in numbers suggests that they should mainly serve as regulatory cells in immunity, rather than effector leukocytes, as still believed by the majority of physicians. In this review we will try to describe and elucidate the possible role of these cells, known as "innate IL4-producing cells" in the immune regulation of allergy and their function in allergen immunotherapy