AMMA information system: an efficient cross-disciplinary tool and a legacy for forthcoming projects

International audienceIn the framework of the African Monsoon Multidisciplinary Analyses (AMMA) programme, several tools have been developed in order to facilitate and speed up data and information exchange between researchers from different disciplines. The AMMA information system includes a multidisciplinary user-friendly distributed data management and distribution system, a reports and quick looks archive associated with a display website and scientific papers exchange systems. All the applications have been developed by several French institutions and fully duplicated in Niamey, Niger

Etude experimentale de la reponse d'une couche limite turbulente a des ondes acoustiques

SIGLEINIST T 71305 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

DNA double-strand breaks induced by mammographic screening procedures in human mammary epithelial cells

International audiencePurpose: To assess in vitro mammographic radiation-induced DNA damage in mammary epithelial cells from 30 patients with low (LR) or high (HR) family risk of breast cancer. Materials and methods: Spontaneous and radiation-induced DNA double-strand breaks (DSB) were quantifi ed by using immunofl uorescence of the phosphorylated H2AX histone ( γ H2AX) in diff erent conditions of mammography irradiation (2, 4, 2 2 mGy). Results: HR patients showed signifi cantly more spontaneous γ H2AX foci than LR patients ( p 0.014). A signifi cant dose-eff ect was observed, with an exacerbation in HR patients ( p 0.01). The dose repetition (2 2 mGy) provided more induced and more unrepaired DSB than 2 mGy and 4 mGy, and was exacerbated in HR ( p 0.006). Conclusions: This study highlights the existence of DSB induced by mammography and revealed by γ H2AX assay with two major radiobiological eff ects occurring: A low-dose eff ect, and a LOw and Repeated Dose (LORD) eff ect. All these eff ects were exacerbated in HR patients. These fi ndings may lead us to reevaluate the number of views performed in screening using a single view (oblique) in women whose mammographic benefi t has not properly been proved such as HR patients

Influence of Nucleoshuttling of the ATM Protein in the Healthy Tissues Response to Radiation Therapy: Toward a Molecular Classification of Human Radiosensitivity

International audiencePURPOSE: Whereas post-radiation therapy overreactions (OR) represent a clinical and societal issue, there is still no consensual radiobiological endpoint to predict clinical radiosensitivity. Since 2003, skin biopsy specimens have been collected from patients treated by radiation therapy against different tumor localizations and showing a wide range of OR. Here, we aimed to establish quantitative links between radiobiological factors and OR severity grades that would be relevant to radioresistant and genetic hyperradiosensitive cases. METHODS AND MATERIALS: Immunofluorescence experiments were performed on a collection of skin fibroblasts from 12 radioresistant, 5 hyperradiosensitive, and 100 OR patients irradiated at 2 Gy. The numbers of micronuclei, γH2AX, and pATM foci that reflect different steps of DNA double-strand breaks (DSB) recognition and repair were assessed from 10 minutes to 24 hours after irradiation and plotted against the severity grades established by the Common Terminology Criteria for Adverse Events and the Radiation Therapy Oncology Group. RESULTS: OR patients did not necessarily show a gross DSB repair defect but a systematic delay in the nucleoshuttling of the ATM protein required for complete DSB recognition. Among the radiobiological factors, the maximal number of pATM foci provided the best discrimination among OR patients and a significant correlation with each OR severity grade, independently of tumor localization and of the early or late nature of reactions. CONCLUSIONS: Our results are consistent with a general classification of human radiosensitivity based on 3 groups: radioresistance (group I); moderate radiosensitivity caused by delay of nucleoshuttling of ATM, which includes OR patients (group II); and hyperradiosensitivity caused by a gross DSB repair defect, which includes fatal cases (group III