Hyperglycaemia and apoptosis of microglial cells in human septic shock

International audienceIntroductionThe effect of hyperglycaemia on the brain cells of septic shock patients is unknown. The objective of this study was to evaluate the relationship between hyperglycaemia and apoptosis in the brains of septic shock patients.MethodsIn a prospective study of 17 patients who died from septic shock, hippocampal tissue was assessed for neuronal ischaemia, neuronal and microglial apoptosis, neuronal Glucose Transporter (GLUT) 4, endothelial inducible Nitric Oxide Synthase (iNOS), microglial GLUT5 expression, microglial and astrocyte activation. Blood glucose (BG) was recorded five times a day from ICU admission to death. Hyperglycaemia was defined as a BG 200 mg/dL g/l and the area under the BG curve (AUBGC) > 2 g/l was assessed.ResultsMedian BG over ICU stay was 2.2 g/l. Neuronal apoptosis was correlated with endothelial iNOS expression (rho = 0.68, P = 0.04), while microglial apoptosis was associated with AUBGC > 2 g/l (rho = 0.70; P = 0.002). Neuronal and microglial apoptosis correlated with each other (rho = 0.69, P = 0.006), but neither correlated with the duration of septic shock, nor with GLUT4 and 5 expression. Neuronal apoptosis and ischaemia tended to correlate with duration of hypotension.ConclusionsIn patients with septic shock, neuronal apoptosis is rather associated with iNOS expression and microglial apoptosis with hyperglycaemia, possibly because GLUT5 is not downregulated. These data provide a mechanistic basis for understanding the neuroprotective effects of glycemic control

Érosion hydraulique à l'interface entre deux couches de sols différents

International audienceContact erosion occurs at the interface of two different soil layers when particles of the finer layer are removed by the flow and transported through the pores of the coarser layer. Whenever this kind of internal erosion occurs in embankment dams, dykes or in their foundations, severe consequences are likely. As contact erosion may be seen as a type of surface erosion, river erosion models have been used by previous authors to model this phenomenon, mainly for contact between sand and gravel layers. Thanks to an specific experimental device, these results are extended to finer soils, broadly-graded, made of clays, silts and sands. The available data for contact erosion is sum-up, and the adequate laws for different situations are underlined. Then, the concept of erosion threshold, useful to evaluate dykes' safety, is discussed and linked with the erosion variability and evolution with time

Érosion de contact entre deux sols

[Departement_IRSTEA]Eaux [TR1_IRSTEA]RIVAGEInternational audienceIn Chapter 4, Rémi Béguin, Pierre Philippe, Yves-Henri Faure and Cyril Guidoux devote their attention to a still under-researched mechanism of erosion, but which can be found in numerous dikes: contact erosion between two types of soil. The description of the mechanisms that take place at grain level allows for a better understanding of the conditions under which they occur as well as of the kinetics of erosion. Finally, several possible scenarios that might lead to a failure of hydraulic structures are being suggested

Leaks detection of earthwork dam with geomembrane lining system by an active technique using optic fibers

International audienc

HI observations of loose galaxy groups

At Nançay, 21-cm H