21 research outputs found
Dynamique des interconnexions des réseaux de transports rapides en Europe : devenir et diffusion spatiale d’un concept géographique
No full textTen years after being highlighted, the concept of trinomial of interconnection relating to integration of the transport systems in Europe deserves a development insofar as such the amount of research on the interconnection processes and the number of trinomial knew of multiple development. The article first of all reconsiders the nature of the conceptas a place of articulation of heterogeneous networks, its structural components and its essential elements of tionality, bases of distinction of the two types of trinomial, one complete and the other integral one. It then tries to understand the reasons of the emergence of such intermodal nodes, the factors of explanation concerning economic, territorial or institutional logics. But, in front of the extent of the field of research thus traversed by several teams and vis-a-vis the diversity of the studies undertaken on the topic of the interconnection, necessary realignments as well as the integration of the concept in a widened corpus are essential then. Passing finally from the local scale on a European scale, the author endeavours to peel the process of diffusion of this innovation, in his diachronic dimension and his spatial extension, using some maps, by identifying the elements of the process, by breaking up the forms of the propagation and by describing phenomena of barrier.Dix ans après avoir été mis en évidence, le concept de trinôme d'interconnexion relatif à l'intégration des réseaux de transport en Europe mérite une mise au point dans la mesure où tant les recherches sur l'interconnexion que le nombre de trinômes ont connu de multiples développements. L'article revient tout d'abord sur la nature du concept comme lieu d'articulation de réseaux hétérogènes, ses composantes structurelles et ses indispensables éléments de fonctionnalité, bases de distinction des deux types de trinômes, l'un complet et l'autre intégral. Il tente ensuite de comprendre les raisons de l'apparition de tels nœuds intermodaux, les facteurs d'explication relevant de logiques économiques, territoriales ou encore institutionnelles. Mais devant l'étendue du champ de recherche ainsi parcouru par plusieurs équipes et face à la diversité des études menées sur le thème de l'interconnexion, s'imposent alors de nécessaires recadrages et intégration du concept dans un corpus élargi. Passant enfin de l'échelle locale à l'échelle européenne, l'auteur s'attache à décortiquer le processus de diffusion de cette innovation, dans sa dimension diachronique et dans son extension spatiale, cartes à l'appui, en identifiant les éléments du processus, en décomposant les formes de la propagation et en décrivant des phénomènes de barrière.Varlet Jean. Dynamique des interconnexions des réseaux de transports rapides en Europe : devenir et diffusion spatiale d’un concept géographique. In: Flux, n°41, 2000. pp. 5-16
Friends and Symptom Dimensions in Patients with Psychosis: A Pooled Analysis
No full textPMCID: PMC3503760This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
ABCES ET EMPYEMES INTRACRANIENS CHEZ L’ENFANT OBSERVES A ABIDJAN (CÔTE D'IVOIRE) (CEREBRAL ABCESS AND INTRACRANIAL EMPYEMAS IN CHILDREN.)
No full textBACKGROUND Abcess and empyemas are frequent intracranial lesions in
children. OBJECTIVES : The authors report the clinicals, radiologicals
bacteriologicals and therapeuticals aspects of these intracranial
suppurations observed in Abidjan. METHOD A retrospective analysis has
been led in the neurosurgical department of university teaching
hospital of Yopougon on 5 years period (December' 93 to december' 98).
That study were based on 34 clinical observations on patients between 7
months and 15 years of age. RESULTS The authors reported 34 cases of
abscess and intracranial empyemas on children subdural empyemas cases
represented 44,1 %, abcess 20,5 % and the two lesions were associated
in 17,6 %. Bacteriological agents isolated on 12 patients were gram
positif cocci (3 cases) heamophilus (2 cases) flora mixed (2 cases) and
a combination of pseudomonas acinetobacter (1 cases). The predisposing
factors were ENT diseases. CONCLUSION : Intracranial subdural empyemas
are most common form of intracranial suppurations seen on child in our
unit. This study can be considered as a speech for the defense of the
use one cerebral abcess and intracranial empyemas surgical drainage via
burrhole. The author stress the interest of eradication of primary
source of the sepsis and the appropriate treatment of head trauma
ABCES ET EMPYEMES INTRACRANIENS CHEZ L’ENFANT OBSERVES A ABIDJAN (CÔTE D'IVOIRE) (CEREBRAL ABCESS AND INTRACRANIAL EMPYEMAS IN CHILDREN.)
No full textBACKGROUND Abcess and empyemas are frequent intracranial lesions in
children. OBJECTIVES : The authors report the clinicals, radiologicals
bacteriologicals and therapeuticals aspects of these intracranial
suppurations observed in Abidjan. METHOD A retrospective analysis has
been led in the neurosurgical department of university teaching
hospital of Yopougon on 5 years period (December' 93 to december' 98).
That study were based on 34 clinical observations on patients between 7
months and 15 years of age. RESULTS The authors reported 34 cases of
abscess and intracranial empyemas on children subdural empyemas cases
represented 44,1 %, abcess 20,5 % and the two lesions were associated
in 17,6 %. Bacteriological agents isolated on 12 patients were gram
positif cocci (3 cases) heamophilus (2 cases) flora mixed (2 cases) and
a combination of pseudomonas acinetobacter (1 cases). The predisposing
factors were ENT diseases. CONCLUSION : Intracranial subdural empyemas
are most common form of intracranial suppurations seen on child in our
unit. This study can be considered as a speech for the defense of the
use one cerebral abcess and intracranial empyemas surgical drainage via
burrhole. The author stress the interest of eradication of primary
source of the sepsis and the appropriate treatment of head trauma
ABCES ET EMPYEMES INTRACRANIENS CHEZ L’ENFANT OBSERVES A ABIDJAN (CÔTE D'IVOIRE) (CEREBRAL ABCESS AND INTRACRANIAL EMPYEMAS IN CHILDREN.)
No full textBACKGROUND Abcess and empyemas are frequent intracranial lesions in
children. OBJECTIVES : The authors report the clinicals, radiologicals
bacteriologicals and therapeuticals aspects of these intracranial
suppurations observed in Abidjan. METHOD A retrospective analysis has
been led in the neurosurgical department of university teaching
hospital of Yopougon on 5 years period (December' 93 to december' 98).
That study were based on 34 clinical observations on patients between 7
months and 15 years of age. RESULTS The authors reported 34 cases of
abscess and intracranial empyemas on children subdural empyemas cases
represented 44,1 %, abcess 20,5 % and the two lesions were associated
in 17,6 %. Bacteriological agents isolated on 12 patients were gram
positif cocci (3 cases) heamophilus (2 cases) flora mixed (2 cases) and
a combination of pseudomonas acinetobacter (1 cases). The predisposing
factors were ENT diseases. CONCLUSION : Intracranial subdural empyemas
are most common form of intracranial suppurations seen on child in our
unit. This study can be considered as a speech for the defense of the
use one cerebral abcess and intracranial empyemas surgical drainage via
burrhole. The author stress the interest of eradication of primary
source of the sepsis and the appropriate treatment of head trauma
Sonocrystallisation of ZIF-8 in water with high excess of ligand: Effects of frequency, power and sonication time
No full textA systematic study on the sonocrystallisation of ZIF-8 (zeolitic imidazolate framework-8) in a water-based system was investigated under different mixing speeds, ultrasound frequencies, calorimetric powers and sonication time. Regardless of the synthesis technique, pure crystals of ZIF-8 with high BET (Brunauer, Emmett and Teller) specific surface area (SSA) can be obtained in water after only 5 s. Furthermore, 5 s sonication produced even smaller crystals (~0.08 µm). The type of technique applied for producing the ZIF-8 crystals did not have any significant impact on crystallinity, purity and yield. Crystal morphology and size were affected by the use of ultrasound and mixing, obtaining nanoparticles with a more spherical shape than in silent condition (no ultrasound and mixing). However, no specific trends were observed with varying frequency, calorimetric power and mixing speed. Ultrasound and mixing may have an effect on the nucleation step, causing the fast production of nucleation centres. Furthermore, the BET SSA increased with increasing mixing speed. With ultrasound, the BET SSA is between the values obtained under silent condition and with mixing. A competition between micromixing and shockwaves has been proposed when sonication is used for ZIF-8 production. The former increases the BET SSA, while the latter could be responsible for porosity damage, causing a decrease of the surface area. © 2021 The Author(s
A driver role for GABA metabolism in controlling stem and proliferative cell state through GHB production in glioma
No full textInternational audienceCell populations with differing proliferative, stem-like and tumorigenic states co-exist in most tumors and especially malignant gliomas. Whether metabolic variations can drive this heterogeneity by controlling dynamic changes in cell states is unknown. Metabolite profiling of human adult glioblastoma stem-like cells upon loss of their tumorigenicity revealed a switch in the catabolism of the GABA neurotransmitter toward enhanced production and secretion of its by-product GHB (4-hydroxybutyrate).This switch was driven by succinic semialdehyde dehydrogenase (SSADH) downregulation. Enhancing GHB levels via SSADH downregulation or GHB supplementation triggered cell conversion into a less aggressive phenotypic state. GHB affected adult glioblastoma cells with varying molecular profiles, along with cells from pediatric pontine gliomas. In all cell types, GHB acted byinhibiting α-ketoglutarate-dependent Ten–eleven Translocations (TET) activity, resulting in decreased levels of the 5-hydroxymethylcytosine epigenetic mark. In patients, low SSADH expression was correlated with high GHB/α- ketoglutarate ratios, and distinguished weakly proliferative/ differentiated glioblastoma territories from proliferative/ non-differentiated territories. Our findings support an active participation of metabolic variations in the genesis of tumor heterogeneity
DIPG-43. CLINICAL AND MOLECULAR CHARACTERISTIC OF A NEW SUBTYPE OF DMG, H3K27-ALTERED WITH MAPK-ACTIVATING CO-DRIVER MUTATIONS
No full textInternational audienceDiffuse midline gliomas (DMG) represent a big challenge in neuro-oncology. These tumors occur more frequently in children and are presently incurable. They are characterized by a K27M substitution in H3.1 or H3.3 histone tail or the overexpression of EZHIP (EZH Inhibitory Protein). These three alterations induce a global loss of trimethylation in H3K27 with a specific epigenic and transcriptomic remodeling. The additional oncogenic events and the clinical behavior are also distinct according to the driver event. Based on these differences, the H3K27-altered DMG is now classified in 4 subtypes by the latest edition of the WHO Classification of CNS tumors. Even with this new subclassification, the H3.3K27M subgroup still appears heterogenous. Recent publications reported that rare patients presenting a co-occurrence of H3.3K27M with BRAF or FGFR1 alterations tend to have a better prognosis. To better study the role of these co-driver alterations that activate the mitogen activated protein kinase (MAPK) signaling, we assembled a large pediatric and adult cohort of H3K27-altered DMG comprising 25 new DMG patients mutated in FGFR1 or BRAFV600E and 37 previous cases from the literature. We performed a comprehensive histological, radiological, genomic, transcriptomic and DNA methylome analysis on this extended cohort. Interestingly, the results show clear differences with other DMG subtypes, including: specific DNA methylation profile, senescence signature, better overall survival (median around 3 years), older age at diagnosis, specific histological and radiological presentations with calcifications or more circumscribed tumors. Additionally, in specific cases, we show that the MAPK-activating mutation occurred subsequently to the histone H3K27M mutation. In conclusion, DMG, H3K27-altered harboring MAPK activating mutations represent a new subtype of DMG also frequent in adults, and deserve further attention with respect to specific therapeutic challenges
A driver role for GABA metabolism in controlling stem and proliferative cell state through GHB production in glioma
No full textCell populations with differing proliferative, stem-like and tumorigenic states co-exist in most tumors and especially malignant gliomas. Whether metabolic variations can drive this heterogeneity by controlling dynamic changes in cell states is unknown. Metabolite profiling of human adult glioblastoma stem-like cells upon loss of their tumorigenicity revealed a switch in the catabolism of the GABA neurotransmitter toward enhanced production and secretion of its by-product GHB (4-hydroxybutyrate). This switch was driven by succinic semialdehyde dehydrogenase (SSADH) downregulation. Enhancing GHB levels via SSADH downregulation or GHB supplementation triggered cell conversion into a less aggressive phenotypic state. GHB affected adult glioblastoma cells with varying molecular profiles, along with cells from pediatric pontine gliomas. In all cell types, GHB acted by inhibiting α-ketoglutarate-dependent Ten–eleven Translocations (TET) activity, resulting in decreased levels of the 5-hydroxymethylcytosine epigenetic mark. In patients, low SSADH expression was correlated with high GHB/α-ketoglutarate ratios, and distinguished weakly proliferative/differentiated glioblastoma territories from proliferative/non-differentiated territories. Our findings support an active participation of metabolic variations in the genesis of tumor heterogeneity. © 2016, The Author(s)
