Cédric Lavigne, Essai sur la planification agraire au Moyen Âge : les paysages neufs de la Gascogne médiévale (xiiie-xive siècles)

Les bastides exercent une véritable attraction sur les historiens. Les travaux de Charles Higounet sur la Gascogne et, plus récemment, ceux de Benoît Cuisente en témoignent. À leur suite, Cédric Lavigne, dont cet ouvrage couronne une thèse de iiie cycle en histoire médiévale (Université de Bordeaux iii), s'est engagé dans cette voie. La campagne entourant les bastides mérite plus d'attention avec l'idée que l'auteur présuppose, en effet, qu'à l'occasion de la fondation des bastides (au milieu..

Isolation of mineralizing Nestin+ Nkx6.1+ vascular muscular cells from the adult human spinal cord

<p>Abstract</p> <p>Background</p> <p>The adult central nervous system (CNS) contains different populations of immature cells that could possibly be used to repair brain and spinal cord lesions. The diversity and the properties of these cells in the human adult CNS remain to be fully explored. We previously isolated Nestin⁺Sox2⁺neural multipotential cells from the adult human spinal cord using the neurosphere method (i.e. non adherent conditions and defined medium).</p> <p>Results</p> <p>Here we report the isolation and long term propagation of another population of Nestin⁺cells from this tissue using adherent culture conditions and serum. QPCR and immunofluorescence indicated that these cells had mesenchymal features as evidenced by the expression of Snai2 and Twist1 and lack of expression of neural markers such as Sox2, Olig2 or GFAP. Indeed, these cells expressed markers typical of smooth muscle vascular cells such as Calponin, Caldesmone and Acta2 (Smooth muscle actin). These cells could not differentiate into chondrocytes, adipocytes, neuronal and glial cells, however they readily mineralized when placed in osteogenic conditions. Further characterization allowed us to identify the Nkx6.1 transcription factor as a marker for these cells. Nkx6.1 was expressed in vivo by CNS vascular muscular cells located in the parenchyma and the meninges.</p> <p>Conclusion</p> <p>Smooth muscle cells expressing Nestin and Nkx6.1 is the main cell population derived from culturing human spinal cord cells in adherent conditions with serum. Mineralization of these cells in vitro could represent a valuable model for studying calcifications of CNS vessels which are observed in pathological situations or as part of the normal aging. In addition, long term propagation of these cells will allow the study of their interaction with other CNS cells and their implication in scar formation during spinal cord injury.</p

The etiopathogenesis of diffuse low-grade gliomas

International audienceThe origins of diffuse low-grade gliomas (DLGG) are unknown. Beyond some limited data on their temporal and cellular origins, the mechanisms and risk factors involved are poorly known. First, based on strong relationships between DLGG development and the eloquence of brain regions frequently invaded by these tumors, we propose a "functional theory" to explain the origin of DLGG. Second, the biological pathways involved in DLGG genesis may differ according to tumor location (anatomo-molecular correlations). The cellular and molecular mechanisms of such "molecular theory" will be reviewed. Third, the geographical distribution of diffuse WHO grade II-III gliomas within populations is heterogeneous, suggesting possible environmental risk factors. We will discuss this "environmental theory". Finally, we will summarize the current knowledge on genetic susceptibility in gliomas ("genetic predisposition theory"). These crucial issues illustrate the close relationships between the pathophysiology of gliomagenesis, the anatomo-functional organization of the brain, and personalized management of DLGG patients

Epidemiology for primary brain tumors: a nationwide population-based study

International audiencePrimary central nervous system tumors (PCNST) are rare tumors responsible for high mortality and morbidity. Their epidemiology is poorly known, and clinical data are scarcely analyzed at a national level. In this study, we aimed at providing descriptive epidemiological data and incidence rates for all histological subtypes of PCNST according to the WHO classification. We conducted a nationwide population-based study of all newly diagnosed and histologically confirmed PCNST in France, between 2006 and 2011. A total of 57,816 patients were included: male 46.4%, median age at diagnosis 56 years old (range 0-99). For all newly diagnosed PCNST with histological confirmation the crude incidence rate was 15.5/105 per 100,000 person-years. To enable international comparisons, standardized rates were calculated: 14.1/105 (population of reference: USA), 14.5/105 (population of reference: Europe), and 12.0/105 (population of reference: world). 23.4% of samples were cryopreserved. Resection was performed in 79.1% of cases. Results are detailed (incidence rate, sex ratio, median age at diagnosis, number of cryopreserved samples, and type of surgery) for each of the 143 histological subtypes of PCNST, including all rare tumors. For example, incidence rates (population of reference: USA) were 0.018/105 for anaplastic gangliogliomas, 0.054/105 for malignant meningiomas, and 0.036/105 for hemangiopericytomas. Our study is the first to describe incidence rates and epidemiological data for all histological subtypes of PCNST, including rare tumors, at a national level. Its methodology ensures the exhaustiveness of the data collection for histologically-proven cases. Histological population-based studies have many perspectives in the field of clinical epidemiology and research

Erratum to: Epidemiology for primary brain tumors: a nationwide population-based study

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SLUG and Truncated TAL1 Reduce Glioblastoma Stem Cell Growth Downstream of Notch1 and Define Distinct Vascular Subpopulations in Glioblastoma Multiforme

International audienceGlioblastomas (GBM) are high-grade brain tumors, containing cells with distinct phenotypes and tumorigenic potentials, notably aggressive and treatment-resistant multipotent glioblastoma stem cells (GSC). The molecular mechanisms controlling GSC plasticity and growth have only partly been elucidated. Contact with endothelial cells and the Notch1 pathway control GSC proliferation and fate. We used three GSC cultures and glioma resections to examine the expression, regulation, and role of two transcription factors, SLUG (SNAI2) and TAL1 (SCL), involved in epithelial to mesenchymal transition (EMT), hematopoiesis, vascular identity, and treatment resistance in various cancers. In vitro, SLUG and a truncated isoform of TAL1 (TAL1-PP22) were strongly upregulated upon Notch1 activation in GSC, together with LMO2, a known cofactor of TAL1, which formed a complex with truncated TAL1. SLUG was also upregulated by TGF-β1 treatment and by co-culture with endothelial cells. In patient samples, the full-length isoform TAL1-PP42 was expressed in all glioma grades. In contrast, SLUG and truncated TAL1 were preferentially overexpressed in GBMs. SLUG and TAL1 are expressed in the tumor microenvironment by perivascular and endothelial cells, respectively, and to a minor extent, by a fraction of epidermal growth factor receptor (EGFR) -amplified GBM cells. Mechanistically, both SLUG and truncated TAL1 reduced GSC growth after their respective overexpression. Collectively, this study provides new evidence for the role of SLUG and TAL1 in regulating GSC plasticity and growth

An epidemiology report for primary central nervous system tumors in adolescents and young adults: a nationwide population-based study in France, 2008–2013

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Characterisation of tumour microenvironment and immune checkpoints in primary central nervous system diffuse large B cell lymphomas

International audiencePrimary central nervous system diffuse large B cell lymphoma (PCNS-DLBCL) is a rare and aggressive entity of diffuse large B cell lymphoma (DLBCL). Elements of the tumour microenvironment (TME) including tumour-infiltrating lymphocytes (TILs) and tumour-associated macrophages (TAMs) have been associated with survival in DLBCL but their composition and prognostic impact in PCNS-DLBCL are unknown. Programmed cell death-1 (PD1)/programmed death-ligand 1 (PD-L1) immune checkpoint may represent a therapeutic option. Here, we aimed to characterise PD1/PDL1 immune checkpoints and the composition of the TME in PCNS-DLBCL. We collected tumour tissue and clinical data from 57 PCNS-DLBCL and used immunohistochemistry to examine TAMs (CD68, CD163), TILs (CD3, CD4, CD8, PD1) and tumour B cells (PAX5/PDL1 double stains, PDL1). The PDL1 gene was evaluated by fluorescence in situ hybridization (FISH). PAX5/PDL1 identified PDL1 expression by tumour B cells in 10/57 cases (17.5%). PDL1 gene translocation was a recurrent cytogenetic alteration in PNCS-DLBCL (8/47.17%) and was correlated with PDL1 positive expression in tumour B cells. The TME consisted predominantly of CD163 (+) M2 TAMs and CD8 (+) TILs. Most TAMs expressed PDL1 and most TILs expressed PD1. The density of TAMs and TILs did not associate with outcome. We showed that expression of PD1 on TILs and PDL1 on TAMs, but not the expression of PDL1 on tumour B cells was correlated with better prognosis. These findings support a significant role of TME composition and PD1/PDL1 crosstalk in PCNS-DLBCL pathogenesis and bring new insights to the targeted therapy of this aggressive lymphoma