"Seul Dieu Nous Protège": Migration et environnement en République démocratique du Congo

Même si l’importance de l’impact des changements environnementaux sur la migration interne en République démocratique du Congo a récemment commencé à recevoir plus d’attention, jusqu’à présent aucune étude n’a encore examiné ce sujet de manière empirique. Ce rapport constitue la première étude de ce type sur les liens entre dégradations de l’environnement et déplacements de populations menée à l’échelle du pays. La recherche met en relief le lien très fort existant entre crises économiques, exploitation anarchique des ressources et dégradations de l’environnement, ainsi que l’assistance insuffisante offerte aux populations touchées par ces dégradations. D’où l’objectif indispensable d’assurer à la fois une meilleure gestion des flux migratoires et une meilleure protection de l’environnement dans le pays

Increased Vascular Permeability in the Bone Marrow Microenvironment Contributes to Disease Progression and Drug Response in Acute Myeloid Leukemia

D.P. was supported by a non-clinical research fellowship from EHA. This work was supported by The Francis Crick Institute, which receives its core funding from Cancer Research UK (FC001045), The UK Medical Research Council (FC001045), and the Welcome Trust (FC001045)

Different Motile Behaviors of Human Hematopoietic Stem versus Progenitor Cells at the Osteoblastic Niche

Despite advances in our understanding of interactions between mouse hematopoietic stem cells (HSCs) and their niche, little is known about communication between human HSCs and the microenvironment. Using a xenotransplantation model and intravital imaging, we demonstrate that human HSCs display distinct motile behaviors to their hematopoietic progenitor cell (HPC) counterparts, and the same pattern can be found between mouse HSCs and HPCs. HSCs become significantly less motile after transplantation, while progenitor cells remain motile. We show that human HSCs take longer to find their niche than previously expected and suggest that the niche be defined as the position where HSCs stop moving. Intravital imaging is the only technique to determine where in the bone marrow stem cells stop moving, and future analyses should focus on the environment surrounding the HSC at this point

Le réseau des Centres de Ressources Biologiques (CRB) et tumorothèques de l'agglomération marseillaise

L'objectif de cette communication est de décrire les aspects actuels et en devenir du fonctionnement du réseau des Centres de Ressources Biologiques et Tumorothèques (CRB) de l'agglomération marseillaise. Ce réseau s'est constitué depuis l'année 2001 en intégrant des acteurs marseillais engagés depuis plusieurs années dans une politique de cryopréservation de tissus et de cellules d'origine humaine à des fins de recherche. Les collections constituées ne sont pas exclusivement des collections de matériel tumoral, mais les deux tumorothèques du Centre Régional de Lutte Contre le Cancer et du Centre Hospitalier et Universitaire hébergent une part importante des collections du réseau. Le travail mené en communa conduit à la reconnaissance et au financement de ce réseau par l'Inserm dans le cadre des appels d'offre « Collections 2003 ». Le réseau travaille à la définition d'une politique scientifique complémentaire entre les établissements, à un partage des pratiques professionnelles pour les aspects logistiques et informatiques, à la mise en place d'une politique commune d'assurance de la qualité, et à la construction d'un catalogue commun des ressources, l'ensemble de ces efforts ayant pour but de mettre progressivement en conformité les banques de tissus et cellules avec les règles de l'Organisation de Coopération et de Développement Économique (OCDE) qui définissent les CRB

Frequency and Dynamics of Leukemia-Initiating Cells during Short-term Ex Vivo Culture Informs Outcomes in Acute Myeloid Leukemia Patients

Acute myeloid leukemia (AML) is sustained by a subpopulation of rare leukemia-initiating cells (LIC) detected in the xenograft assay by their capacity to self-renew and to generate non-LICs in vivo. The xenotransplantation model captures functional properties of LICs that have clinical prognostic value. However, the long duration of this in vivo assay has hampered its use as a prognostic tool. Here, we show, using an ex vivo coculture system, that intermediate and poor risk AML patient samples at diagnosis have a 5 to 7 times higher frequency of leukemic long-term culture-initiating cells (L-LTC-IC) compared with the good risk group. We defined a fluorescence dilution factor (FDF) parameter that monitors sample proliferation over 1 week and established a strong correlation of this parameter with the L-LTC-IC frequency. A higher FDF was found for poor prognostic AMLs or for samples capable of engrafting NSG mice compared with good risk AMLs or nonengrafters. Importantly, FDF could classify normal karyotype intermediate risk patients into two groups with a significant difference in their overall survival, thus making this nongenetic and non-in vivo approach a new clinically relevant tool for better diagnosis of AML patients.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

A tool to predict progression of non-alcoholic fatty liver disease in severely obese patients

International audienceBackground & AimsSeverely obese patients are a growing population at risk of non-alcoholic fatty liver disease (NAFLD). Considering the increasing burden, a predictive tool of NAFLD progression would be of interest. Our objective was to provide a tool allowing general practitioners to identify and refer the patients most at risk, and specialists to estimate disease progression and adapt the therapeutic strategy.MethodsThis predictive tool is based on a Markov model simulating steatosis, fibrosis and non-alcoholic steatohepatitis (NASH) evolution. This model was developped from data of 1801 severely obese, bariatric surgery candidates, with histological assessment, integrating duration of exposure to risk factors. It is then able to predict current disease severity in the absence of assessment, and future cirrhosis risk based on current stage.ResultsThe model quantifies the impact of sex, body-mass index at 20, diabetes, age of overweight onset, on progression. For example, for 40-year-old severely obese patients seen by the general practitioners: (a) non-diabetic woman overweight at 20, and (b) diabetic man overweight at 10, without disease assessment, the model predicts their current risk to have NASH or F3-F4: for (a) 5.7% and 0.6%, for (b) 16.1% and 10.0% respectively. If those patients have been diagnosed F2 by the specialist, the model predicts the 5-year cirrhosis risk: 1.8% in the absence of NASH and 6.0% in its presence for (a), 10.3% and 26.7% respectively, for (b).ConclusionsThis model provides a decision-making tool to predict the risk of liver disease that could help manage severely obese patients