128 research outputs found
Assessment of the Central Effects of Natural Uranium via Behavioural Performances and the Cerebrospinal Fluid Metabolome
International audienceNatural uranium (NU), a component of the earth's crust, is not only a heavy metal but also an alpha particle emitter, with chemical and radiological toxicity. Populations may therefore be chronically exposed to NU through drinking water and food. Since the central nervous system is known to be sensitive to pollutants during its development, we assessed the effects on the behaviour and the cerebrospinal fluid (CSF) metabolome of rats exposed for 9 months from birth to NU via lactation and drinking water (1.5, 10, or 40 mgâ
L â1 for male rats and 40 mgâ
L â1 for female rats). Medium-term memory decreased in comparison to controls in male rats exposed to 1.5, 10, or 40 mgâ
L â1 NU. In male rats, spatial working memory and anxiety-and depressive-like behaviour were only altered by exposure to 40 mgâ
L â1 NU and any significant effect was observed on locomotor activity. In female rats exposed to NU, only locomotor activity was significantly increased in comparison with controls. LC-MS metabolomics of CSF discriminated the fingerprints of the male and/or female NU-exposed and control groups. This study suggests that exposure to environmental doses of NU from development to adulthood can have an impact on rat brain function
Role of oxygen exposure on the differentiation of human induced pluripotent stem cells in 2D and 3D cardiac organoids
Introduction Human induced pluripotent stem cells (hiPSC) have the ability to differentiate theoritically into any cell type. The development of organoid systems exhibiting the essential features of human organ such as liver and heart is of high interest. Optimizing the culture conditions to obtain the highest cardiac organoids efficacy is crucial. In fact, cardiac differentiation protocols have been established by essentially focusing on specific growth factors on hiPSC differentiation efficiency. However, the optimal environmental factors such as the optimal oxygen exposure to obtain cardiac myocytes in network are still unclear. The mesoderm germ layer differentiation is known to be enhanced by low oxygen exposure. Yet, the effect of low oxygen exposure on the molecular and functional maturity of the hiPSC-derived cardiomyocytes remains unexplored. Aims We aimed here at comparing the molecular and functional consequences of low (5% O2 or LOE) and high oxygen exposure (21% O2 or HOE) on cardiac differentiation of hiPSCs in 2D monolayer and 3D organoids protocols. Methods hiPSC-CMs were differentiated through both the 2D (monolayer) and 3D (embryoid body) protocols using several lines. Cardiac marker expression and cell morphology were assessed using qRT-PCR and immunofluorescence. The mitochondrial localization and metabolic properties were evaluated by high-resolution respirometry and mitochondrial staining. The intracellular Ca2+ handling and contractile properties were also monitored using confocal fluorescent microscopy and atomic force microscopy. Results Our results indicated that the 2D cardiac monolayer can only be differentiated in HOE. The 3D cardiac organoids containing hiPSC-CMs in LOE exhibited higher cardiac markers expression such as troponin T (TnTc), RyR2, Serca2a, alpha and beta heavy myosin chains. Moreover, we found enhanced contractile force, hypertrophy and steadier SR Ca2+ release reflected by a more regular spontaneous Ca2+ transients associated with a higher maximal amplitude and lower spontaneous Ca2+ events revealing a better SR Ca2+ handling in LOE. Similar beat rate, preserved distribution of mitochondria and similar oxygen consumption by the mitochondrial respiratory chain complexes were also observed. Conclusions Our results brought evidences that LOE is moderately beneficial for the 3D cardiac organoids with hPSC-CMs exhibiting further maturity. In contrast, the 2D cardiac monolayers strictly require HOE.Introduction Human induced pluripotent stem cells (hiPSC) have the ability to differentiate theoritically into any cell type. The development of organoid systems exhibiting the essential features of human organ such as liver and heart is of high interest. Optimizing the culture conditions to obtain the highest cardiac organoids efficacy is crucial. In fact, cardiac differentiation protocols have been established by essentially focusing on specific growth factors on hiPSC differentiation efficiency. However, the optimal environmental factors such as the optimal oxygen exposure to obtain cardiac myocytes in network are still unclear. The mesoderm germ layer differentiation is known to be enhanced by low oxygen exposure. Yet, the effect of low oxygen exposure on the molecular and functional maturity of the hiPSC-derived cardiomyocytes remains unexplored. Aims We aimed here at comparing the molecular and functional consequences of low (5% O2 or LOE) and high oxygen exposure (21% O2 or HOE) on cardiac differentiation of hiPSCs in 2D monolayer and 3D organoids protocols. Methods hiPSC-CMs were differentiated through both the 2D (monolayer) and 3D (embryoid body) protocols using several lines. Cardiac marker expression and cell morphology were assessed using qRT-PCR and immunofluorescence. The mitochondrial localization and metabolic properties were evaluated by high-resolution respirometry and mitochondrial staining. The intracellular Ca2+ handling and contractile properties were also monitored using confocal fluorescent microscopy and atomic force microscopy. Results Our results indicated that the 2D cardiac monolayer can only be differentiated in HOE. The 3D cardiac organoids containing hiPSC-CMs in LOE exhibited higher cardiac markers expression such as troponin T (TnTc), RyR2, Serca2a, alpha and beta heavy myosin chains. Moreover, we found enhanced contractile force, hypertrophy and steadier SR Ca2+ release reflected by a more regular spontaneous Ca2+ transients associated with a higher maximal amplitude and lower spontaneous Ca2+ events revealing a better SR Ca2+ handling in LOE. Similar beat rate, preserved distribution of mitochondria and similar oxygen consumption by the mitochondrial respiratory chain complexes were also observed. Conclusions Our results brought evidences that LOE is moderately beneficial for the 3D cardiac organoids with hPSC-CMs exhibiting further maturity. In contrast, the 2D cardiac monolayers strictly require HOE
Biomethane potential of industrial paper wastes and investigation of the methanogenic communities involved
Bio-indicateurs potentiels d'atteinte multi-organe : application au cas des victimes d'irradiation accidentelles
Accidental irradiations induce a complex pathological situation, difficult to assess and to treat. However, recent results describing new biological indicators of radiation-induced damages such as Flt3-ligand, citrulline and oxysterol concentration in the plasma, together with results obtained in large animal models of high dose irradiation, allowed a better understanding of pathophysiological mechanisms induced by uncontrolled irradiations. This conducted to leave the classical paradigm of the acute radiation syndrome, described as the association of three individual syndromes, the hematopoietic syndrome, the gastro-intestinal syndrome and the cerebrovascular syndrome, in favour of a multiple organ dysfunction syndrome, with the implication of other organs and systems. Follow-up of victims from two recent radiation accidents brings a confirmation of the usefulness of the newly described biological indicators, and also a partial confirmation of this new concept of a multiple organ dysfunction syndrome. © 2009 Elsevier Masson SAS. All rights reserved.Les irradiations accidentelles conduisent Ă des situations pathologiques complexes, difficiles Ă Ă©valuer et Ă traiter. Cependant, des rĂ©sultats rĂ©cents ont permis de dĂ©finir de nouveaux bio-indicateurs de dommages radio-induits comme le Flt3-ligand, la citrulline ou les oxystĂ©rols plasmatiques. Par ailleurs, des Ă©tudes sur des modĂšles animaux ont permis une Ă©volution de la comprĂ©hension des mĂ©canismes physiopathologiques des irradiations complexes Ă forte dose. Cette Ă©volution conduit Ă abandonner le concept de syndrome aigu dâirradiation comme Ă©tant une association de trois syndromes bien individualisĂ©s, le syndrome hĂ©matopoĂŻĂ©tique, le syndrome gastro-intestinal et le syndrome cĂ©rĂ©brovasculaire au profit dâun concept de syndrome de dysfonctionnement multi-organes, avec lâimplication dâautres systĂšmes physiologiques. Le suivi des victimes de deux accidents dâirradiation rĂ©cents a permis de confirmer la validitĂ© des nouveaux bio-indicateurs utilisĂ©s, mais a apportĂ© aussi un dĂ©but de confirmation de ce concept de syndrome de dysfonctionnement multi-organes induit par une irradiation accidentelle
An Adaptive QoEâBased Network Interface Selection for Multiâhomed eHealth Devices
International audienceConventional network control mechanisms are no longer suitable for Internet of Things (IoT) because they donât allow scalability with a guarantee of Quality of Experience (QoE) especially when it comes to the health sector characterized by its real time and critical life aspects. Thatâs why we need to think differently about control. One aspect consists of improving the network accessibility by considering Multi-homed terminals using multiple network access points simultaneously. In this paper we present a new Q-Learning-based adaptive network interface selection approach. Experimental results show that the proposed approach involve QoE compared to a simple linear programming approach. abstract environment
Uranium appauvri: Perturbateur métabolique?
The presence of uranium in the environment can lead to long-term contamination of the food chain and of water intended for human consumption and thus raises many questions about the scientific and societal consequences of this exposure on population health. Although the biological effects of chronic low-level exposure are poorly understood, results of various recent studies show that contamination by depleted uranium (DU) induces subtle but significant biological effects at the molecular level in organs including the brain, liver, kidneys and testicles. For the first time, it has been demonstrated that DU induces effects on several metabolic pathways, including those metabolising vitamin D, cholesterol, steroid hormones, acetylcholine and xenobiotics. This evidence strongly suggests that DU might well interfere with many metabolic pathways. It might thus contribute, together with other man-made substances in the environment, to increased health risks in some regions.AnnĂ©e de parution : 2011 La prĂ©sence dâuranium dans lâenvironnement peut conduire Ă long terme Ă une contamination de la chaĂźne alimentaire et/ou des eaux destinĂ©es Ă la consommation humaine, soulevant alors de nombreuses interrogations scientifiques et sociĂ©tales quant aux consĂ©quences de cette exposition sur la santĂ© des populations. Les effets biologiques dâune exposition chronique Ă de faibles niveaux sont peu connus. Cependant, les rĂ©sultats de diffĂ©rentes Ă©tudes rĂ©centes montrent que ce type de contamination Ă lâuranium appauvri induirait des effets biologiques de types molĂ©culaires subtils, mais significatifs, dans des organes tels que le cerveau, le foie, les reins et les testicules. La grande nouveautĂ© dans les effets induits aprĂšs contamination interne par lâuranium est la mise en Ă©vidence dâeffets sur un certain nombre de mĂ©tabolismes majeurs de lâorganisme comme le mĂ©tabolisme de la vitamine D, du cholestĂ©rol, des hormones stĂ©roĂŻdiennes, de lâacĂ©tylcholine et des xĂ©nobiotiques. Ces donnĂ©es scientifiques suggĂšrent fortement que lâuranium est susceptible dâinterfĂ©rer avec de nombreuses voies mĂ©taboliques. Ainsi, il pourrait contribuer, avec dâautres substances artificielles prĂ©sentes dans lâenvironnement, Ă lâaugmentation des risques sanitaires dans certaines rĂ©gions du globe
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