Angiogenic Factors Stimulate Growth of Adult Neural Stem Cells

The ability to grow a uniform cell type from the adult central nervous system (CNS) is valuable for developing cell therapies and new strategies for drug discovery. The adult mammalian brain is a source of neural stem cells (NSC) found in both neurogenic and non-neurogenic zones but difficulties in culturing these hinders their use as research tools.Here we show that NSCs can be efficiently grown in adherent cell cultures when angiogenic signals are included in the medium. These signals include both anti-angiogenic factors (the soluble form of the Notch receptor ligand, Dll4) and pro-angiogenic factors (the Tie-2 receptor ligand, Angiopoietin 2). These treatments support the self renewal state of cultured NSCs and expression of the transcription factor Hes3, which also identifies the cancer stem cell population in human tumors. In an organotypic slice model, angiogenic factors maintain vascular structure and increase the density of dopamine neuron processes.We demonstrate new properties of adult NSCs and a method to generate efficient adult NSC cultures from various central nervous system areas. These findings will help establish cellular models relevant to cancer and regeneration

A pH-and Metal-Actuated Molecular Shuttle in Water

International audienceThe structure of the Viologen-Phenylene-Imidazole (VPI) guest, previously shown to be bound by cucurbit[7]uril (CB[7]) with binding modes depending on pH and silver ions, has been extended by adding hydrophobic groups on the two extremities of VPI before investigations of CB[7] binding by NMR, ITC, X-ray diffraction, UV-vis and fluorescence spectroscopies. With an imidazole station extended by a naphthalene group (VPI-N), binding modes of CB[7] are similar to those previously observed. However, with the viologen extended by a tolyl group (T-VPI), CB[7] preferentially sits on station T, shuttling between the T and P stations at acid pH or after Ag + addition. The CB[7]•T-VPI complex thus behaves as a metal-actuated thermodynamic stop-and-go molecular shuttle featured by fast and autonomous ring translocation between two stations and a continuum for fractional station occupancy solely and easily controlled by Ag + concentration

PenBase, the shrimp antimicrobial peptide penaeidin database: Sequence-based classification and recommended nomenclature

International audienc

En direct avec les scientifiques: 150 questions sur l'océan et le climat

Ce livre est le témoin vivant d un échange riche et unique entre 16 scientifiques et le grand public. Le changement climatique, en partie dû aux activités humaines, affecte l océan, régulateur important du climat. Les effets s observent déjà à l'échelle du monde : fonte des glaces continentales et océaniques, montée des eaux, acidification de l'océan... et leur impact sur les sociétés humaines s accentuera dans le demi-siècle à venir. Il nous faut anticiper et pour nous adapter, mieux connaître l océan et son rôle dans le climat, trouver des solutions applicables et acceptables par les populations. C est à cette relation étroite et fragile entre le climat, l océan et les hommes que s est intéressée l exposition qui a eu lieu à la Cité des sciences entre le 6 avril 2011 et fin juin 2012. Expérience séduisante, une borne permettait aux visiteurs de tous âges de poser leurs questions, auxquelles 16 scientifiques ont répondu en fonction de leur domaine d expertise. " Comment se forment les vagues ? ", " Les ours polaires survivront-ils au réchauffement climatique ? ", " C est quoi un tsunami ? ", " Venise sera-t-elle un jour sous l eau ? ", " L évolution actuelle du climat est-elle irréversible ? ", " Les changements climatiques vont-ils provoquer des guerres ? ", " Quelle est la mer la plus polluée ? ", " Combien y a-t-il de CO2 dans la mer ? "... En tout, 150 questions et leurs réponses accessibles et ludiques. L ouvrage, mine d informations à la mise en pages graphique et aérée, a été conçu pour que le lecteur s y oriente le plus librement possible, s y promène à son gré selon ses propres interrogations, car chaque réponse peut se lire indépendamment des autres

Whole-body MR imaging in suspected physical child abuse: comparison with skeletal survey and bone scintigraphy findings from the PEDIMA prospective multicentre study

International audienceObjectives: To assess the contribution of whole-body magnetic resonance imaging (WBMRI) and bone scintigraphy (BS) in addition to skeletal survey (SS) in detecting traumatic bone lesions and soft-tissue injuries in suspected child abuse.Methods: In this prospective, multicentre, diagnostic accuracy study, children less than 3 years of age with suspected physical abuse were recruited. Each child underwent SS, BS and WBMRI. A blinded first review was performed in consensus by five paediatric radiologists and three nuclear medicine physicians. A second review investigated discrepancies reported between the modalities using a consensus result of all modalities as the reference standard. We calculated the sensitivity, specificity and corresponding 95% confidence interval for each imaging modality (SS, WBMRI and BS) and for the combinations [SS + WBMRI] and [SS + BS].Results: One hundred seventy children were included of which sixty-four had at least one lesion. In total, 146 lesions were included. The sensitivity and specificity of each examination were, respectively, as follows: 88.4% [95% CI, 82.0-93.1] and 99.7% [95% CI, 99.5-99.8] for the SS, 69.9% [95% CI, 61.7-77.2] and 99.5% [95% CI, 99.2-99.7] for WBMRI and 54.8% [95% CI, 46.4-63.0] and 99.7% [95% CI, 99.5-99.9] for BS. Sensitivity and specificity were, respectively, 95.9% [95% CI, 91.3-98.5] and 99.2% [95% CI, 98.9-99.4] for the combination SS + WBMRI and 95.2% [95% CI, 90.4-98.1] and 99.4% [95% CI, 99.2-99.6] for the combination SS + BS, with no statistically significant difference between them.Conclusion: SS was the most sensitive independent imaging modality; however, the additional combination of either WBMRI or BS examinations offered an increased accuracy.Key points: • SS in suspected infant abuse was the most sensitive independent imaging modality in this study, especially for detecting metaphyseal and rib lesions, and remains essential for evaluation. • The combination of either SS + BS or SS + WBMRI provides greater accuracy in diagnosing occult and equivocal bone injuries in the difficult setting of child abuse. • WBMRI is a free-radiation technique that allows additional diagnosis of soft-tissue and visceral injuries