On a numerical construction of doubly stochastic matrices with prescribed eigenvalues

We study the inverse eigenvalue problem for finding doubly stochastic matrices with specified eigenvalues. By making use of a combination of Dykstra's algorithm and an alternating projection process onto a non-convex set, we derive hybrid algorithms for finding doubly stochastic matrices and symmetric doubly stochastic matrices with prescribed eigenvalues. Furthermore, we prove that the proposed algorithms converge and linear convergence is also proved. Numerical examples are presented to demonstrate the efficiency of our method.Comment: 16 page

Oxidative stress and anxiety: Relationship and cellular pathways

High O2 consumption, modest antioxidant defenses and a lipid-rich constitution make the brain highly vulnerable to redox imbalances. Oxidative damage in the brain causes nervous system impairment. Recently, oxidative stress has also been implicated in depression, anxiety disorders and high anxiety levels. The findings which establish a link between oxidative stress and pathological anxiety have inspired a number of other recent studies focusing on the link between oxidative status and normal anxiety and also on a possible causal relationship between cellular oxidative stress and emotional stress. This review examines the recent discoveries made on the link between oxidative status and normal anxiety levels and the putative role of oxidative stress in genesis of anxiety. We discuss the different opinions and questions that exist in the field and review the methodological approaches that are being used to determine a causal relationship between oxidative and emotional stress

BIOSORPTION OF METHYLENE BLUE FROM WASTE WATER USING LEBANESE CYMBOPOGON CITRATUS (CITRONNELLE)

The objective of this study was to investigate the possibility of using Lebanese Cymbopogon citratus stem as an alternative adsorbent for the removal of methylene blue from aqueous solutions. Different parameters such as the effect of initial concentration, pH, adsorbent dose, contact time and temperature were studied. Maximum adsorption capacity (61%) of MB was obtained at PH=6 an initial concentration 200 mg/L after 24h and at 25 ˚C. The adsorption isotherm was better described by a Freundlich model rather than a Langmiur model. Based on these results, it can be concluded that the stems of Cymbopogon citratus is effective as an alternative adsorbent for MB remediation in waste water

BIOSORPTION OF METHYLENE BLUE FROM WASTE WATER USING LEBANESE CYMBOPOGON CITRATUS (CITRONNELLE)

The objective of this study was to investigate the possibility of using Lebanese Cymbopogon citratus stem as an alternative adsorbent for the removal of methylene blue from aqueous solutions. Different parameters such as the effect of initial concentration, pH, adsorbent dose, contact time and temperature were studied. Maximum adsorption capacity (61%) of MB was obtained at PH=6 an initial concentration 200 mg/L after 24h and at 25 ˚C. The adsorption isotherm was better described by a Freundlich model rather than a Langmiur model. Based on these results, it can be concluded that the stems of Cymbopogon citratus is effective as an alternative adsorbent for MB remediation in waste water

VALPROIC ACID INDUCES APOPTOSIS AND INCREASES CXCR7 EXPRESSION IN EPITHELIAL OVARIAN CANCER CELL LINE SKOV-3.

Background: The chemokine receptor, CXCR7 is described to play a biologically relevant role in tumor growth and spread. Recently, it was reported that CXCR7 overexpression is associated with an unfavorable prognosis and metastatis of epithelial ovarian cancer (EOC). Aware that, several reports indicated that Histone deacetylases (HDACs) regulate the expression and activity of many proteins involved in both cancer initiation and progression, the aim of this work, was to study the effect of the HDAC inhibitor valproic acid (VPA) on the expression of CXCR7 as well as its impact on survival function in the epithelial ovarian cell line (SKOV-3). Methods: cells were cultured with varying concentrations of VPA (1, 2, 3, 4, 5 and 10 mM) for different durations (0, 12 h, 24 h and 48 h). Cell survival was assessed by Neutral red assay and by colony counting which being stained with crystal violet. CXCR7 expression was determined at mRNA level using quantitative real-time PCR (qRT-PCR) or at the protein level using western blotting. Results: VPA reduces cell survival of SKOV-3 cancer cells. The inhibition effect of VPA was dose and time-dependent. Exposure to VPA at concentrations above 2 mM at 24 h resulted in an increase expression of CXCR7 at both the mRNA and protein levels . Conclusion: These observations provide, for the first time, a better insight into the epigenetic mechanisms involved in regulating CXCR7 expression in EOC and will open new avenues for evaluating drugs that specifically stimulate the apoptosis of EOC with minimal unwanted side effect

Bioadsorption of Pb

Herein, the efficiency of Eucalyptus camaldulensis leaves as biosorbent for lead and copper was investigated. The particle size distribution was determined by Granulometric analysis and the functional groups were identified by FT-IR spectroscopy. The effects of contact time, pH and initial metal ions concentration were investigated. The experimental kinetic data were well fitted by the pseudo-second order kinetic model and Langmuir isotherm with a maximum adsorption capacity up to 71 mg g-1 and 37 mg g-1 for Cu2+ and Pb2+ respectively. The selectivity was examined in a binary ions solution where the adsorbent showed preference for lead over copper

VALPROIC ACID INDUCES APOPTOSIS AND INCREASES CXCR7 EXPRESSION IN EPITHELIAL OVARIAN CANCER CELL LINE SKOV-3.

Background: The chemokine receptor, CXCR7 is described to play a biologically relevant role in tumor growth and spread. Recently, it was reported that CXCR7 overexpression is associated with an unfavorable prognosis and metastatis of epithelial ovarian cancer (EOC). Aware that, several reports indicated that Histone deacetylases (HDACs) regulate the expression and activity of many proteins involved in both cancer initiation and progression, the aim of this work, was to study the effect of the HDAC inhibitor valproic acid (VPA) on the expression of CXCR7 as well as its impact on survival function in the epithelial ovarian cell line (SKOV-3). Methods: cells were cultured with varying concentrations of VPA (1, 2, 3, 4, 5 and 10 mM) for different durations (0, 12 h, 24 h and 48 h). Cell survival was assessed by Neutral red assay and by colony counting which being stained with crystal violet. CXCR7 expression was determined at mRNA level using quantitative real-time PCR (qRT-PCR) or at the protein level using western blotting. Results: VPA reduces cell survival of SKOV-3 cancer cells. The inhibition effect of VPA was dose and time-dependent. Exposure to VPA at concentrations above 2 mM at 24 h resulted in an increase expression of CXCR7 at both the mRNA and protein levels . Conclusion: These observations provide, for the first time, a better insight into the epigenetic mechanisms involved in regulating CXCR7 expression in EOC and will open new avenues for evaluating drugs that specifically stimulate the apoptosis of EOC with minimal unwanted side effect

L'anxiété trait et son lien avec l'expression des sous-unités des récepteurs (GABAA, 5-HT1A, µ-opioïdes et x1-adrénérgiques) et des marqueurs du stress oxydatif au niveau du SNC (neurones et cellules gliales) et au niveau périphérique (immunité cellulaire et humorale) : évaluation des effets de substances naturelles à potentiel cytoprotecteur

In this study, genes expression from four central receptors (GABAA, 5-HT1A, m-opioïdes and a1-adrenergic) involved in the modulation of anxiety was assessed. The impact of anxiety on the cellular and humoral immunity and on the oxidative status at the SNC (neurons and glial cells) and peripheral (lymphocytes, granulocytes and monocytes) level was highlighted. At the same time, the effect of anxiety coupled with an anxiogenic restraint stress, on the cellular and humoral immunity was also evaluated. Indeed, the high level of anxiety induced firstly, a significant depressive effect on cellular (total lymphocytes, TCD4+ and TCD8+) and humoral (IgA and IgE) immunity, and secondly, a significant increase of the level of intracellular reactive oxygen species (ROS) of neurons and glial cells in the cerebral cortex, the cerebellum and the hippocampus and in the peripheral blood granulocytes, monocytes and lymphocytes. In the same way, the anxiety coupled to acute and chronic restraint stress provoked, a depression of some parameters of cellular (total lymphocytes, TCD4+, TCD8+ and NK) and humoral (IgA, E and G) immunity, and a stimulation of others (granulocytes and monocytes). These works thus made it possible to validate scientifically the anxiogenic character of the model of restraint stress, to establish in a valid and reproducible way the bond and the correlation between the high level of anxiety in animals and their oxidative status inductive of a cytotoxicity as well as the role of the expression of coding genes of 4 receptors in the expression of this high anxiety and of a significant oxidative status at the level of the peripheral cells of the immune system and the neurons and glial cells at the central levelAu cours de cette étude, l expression des gènes codants de quatre sous types de récepteurs centraux (GABAA, 5-HT1A, m-opioïdes et a1-adrénergiques) impliqués dans la modulation de l anxiété a été évaluée. L impact de l anxiété trait sur les réponses immunitaires cellulaire et humorale et sur le niveau du statut oxydatif au niveau du SNC (neurones et cellules gliales) et au niveau périphérique (lymphocytes, granulocytes et monocytes) a été mis en évidence. En même temps, l effet de l anxiété trait couplée au modèle de stress expérimental anxiogène par contention, sur les réponses immunitaires cellulaire et humorale a été évalué. En effet, le niveau élevé d anxiété induit d une part, un effet dépressif significatif sur l immunité cellulaire (lymphocytes totaux, TCD4+ et TCD8+) et humorale (IgA et IgE) et d autre part, une augmentation significative du niveau intracellulaire des espèces réactives de l oxygène (ERO) des neurones et des cellules gliales au niveau du cortex cérébral, du cervelet et de l hippocampe et des granulocytes, des lymphocytes et des monocytes au niveau périphérique. De la même manière, l anxiété trait couplée au stress aigu et chronique par contention a provoqué une dépression de certains paramètres de l immunité cellulaire (lymphocytes totaux, TCD4+, TCD8+ et NK) et humorale (IgA, E et G) et une stimulation des autres paramètres (granulocytes et monocytes). Ces travaux ont permis ainsi de valider scientifiquement le caractère anxiogène du modèle du stress par contention, d établir de manière valide et reproductible le lien et la corrélation entre le niveau élevé d anxiété chez des animaux et leur statut oxydatif inducteur d une cytotoxicité ainsi que le rôle de l expression des gènes codants de 4 sous types de récepteurs dans l expression de cette anxiété élevée et d un statut oxydatif important au niveau des cellules périphériques du système immunitaire et des neurones et cellules gliales au niveau central

Trait anxiety and its relationship with the expression of receptors (GABAA, 5-HT1A, -opioïdes and a1-adrenergic) and markers of oxidative stress in CNS (neuros and glial cells) and in peripheral system (cellular and humoral immunity) : evaluation of the effets of natural substances with cyctoprotective potential

Au cours de cette étude, l expression des gènes codants de quatre sous types de récepteurs centraux (GABAA, 5-HT1A, m-opioïdes et a1-adrénergiques) impliqués dans la modulation de l anxiété a été évaluée. L impact de l anxiété trait sur les réponses immunitaires cellulaire et humorale et sur le niveau du statut oxydatif au niveau du SNC (neurones et cellules gliales) et au niveau périphérique (lymphocytes, granulocytes et monocytes) a été mis en évidence. En même temps, l effet de l anxiété trait couplée au modèle de stress expérimental anxiogène par contention, sur les réponses immunitaires cellulaire et humorale a été évalué. En effet, le niveau élevé d anxiété induit d une part, un effet dépressif significatif sur l immunité cellulaire (lymphocytes totaux, TCD4+ et TCD8+) et humorale (IgA et IgE) et d autre part, une augmentation significative du niveau intracellulaire des espèces réactives de l oxygène (ERO) des neurones et des cellules gliales au niveau du cortex cérébral, du cervelet et de l hippocampe et des granulocytes, des lymphocytes et des monocytes au niveau périphérique. De la même manière, l anxiété trait couplée au stress aigu et chronique par contention a provoqué une dépression de certains paramètres de l immunité cellulaire (lymphocytes totaux, TCD4+, TCD8+ et NK) et humorale (IgA, E et G) et une stimulation des autres paramètres (granulocytes et monocytes). Ces travaux ont permis ainsi de valider scientifiquement le caractère anxiogène du modèle du stress par contention, d établir de manière valide et reproductible le lien et la corrélation entre le niveau élevé d anxiété chez des animaux et leur statut oxydatif inducteur d une cytotoxicité ainsi que le rôle de l expression des gènes codants de 4 sous types de récepteurs dans l expression de cette anxiété élevée et d un statut oxydatif important au niveau des cellules périphériques du système immunitaire et des neurones et cellules gliales au niveau central.In this study, genes expression from four central receptors (GABAA, 5-HT1A, m-opioïdes and a1-adrenergic) involved in the modulation of anxiety was assessed. The impact of anxiety on the cellular and humoral immunity and on the oxidative status at the SNC (neurons and glial cells) and peripheral (lymphocytes, granulocytes and monocytes) level was highlighted. At the same time, the effect of anxiety coupled with an anxiogenic restraint stress, on the cellular and humoral immunity was also evaluated. Indeed, the high level of anxiety induced firstly, a significant depressive effect on cellular (total lymphocytes, TCD4+ and TCD8+) and humoral (IgA and IgE) immunity, and secondly, a significant increase of the level of intracellular reactive oxygen species (ROS) of neurons and glial cells in the cerebral cortex, the cerebellum and the hippocampus and in the peripheral blood granulocytes, monocytes and lymphocytes. In the same way, the anxiety coupled to acute and chronic restraint stress provoked, a depression of some parameters of cellular (total lymphocytes, TCD4+, TCD8+ and NK) and humoral (IgA, E and G) immunity, and a stimulation of others (granulocytes and monocytes). These works thus made it possible to validate scientifically the anxiogenic character of the model of restraint stress, to establish in a valid and reproducible way the bond and the correlation between the high level of anxiety in animals and their oxidative status inductive of a cytotoxicity as well as the role of the expression of coding genes of 4 receptors in the expression of this high anxiety and of a significant oxidative status at the level of the peripheral cells of the immune system and the neurons and glial cells at the central leve

Comparaison de la capacité de différenciation en cellules endothéliales, de deux types de cellules souches mésenchymateuses issues de la gelée de Wharton et de la moelle osseuse

The incidence of cardiovascular disease remains a major public health problem. Despite the development of endovascular therapies, surgical treatment is necessary for many patients. The low availability of natural vessels, autologous or not, and the mechanical and biological limits of artificial substitutes, led to the use of a new domain: vascular engineering. In recent years, the concept has emerged and evolved. He could afford to offer new types of synthetic vascular substitutes and / or biological, in particular through the use of stem cells, offering interesting perspectives in the field of vascular engineering. The purpose of this study was to obtain a reliable and reproducible protocol to generate functional endothelial cells (ECs) from mesenchymal stem cells (MSCs) derived from the umbilical cord Wharton's jelly (WJ) and bone marrow (BM). Nevertheless, their differentiation into vascular cells needs a culture surface functionalization; our group demonstrated the potential use of polyelectrolyte multilayer made of poly(allylamine hydrochloride): PAH, and poly(styrene sulfonate): PSS, in promoting cells adhesion, proliferation and differentiation. Cells were cultured on (PAH-PSS)4 films or collagen type I (used as control), in the presence of angiogenic growth factors. Cells differentiation into EC was followed through the expression of endothelial markers (PCR and western blot); cell functionality was checked through their ability to incorporate acetylated LDL (Low Density Lipoprotein), to produce NO (Nitric oxide) and to express the von Willebrand factor (vWF). After 14 days of stimulation, only WJ-MSCs were able to generate functional ECs demonstrating the potential of combining WJ-MSCs and (PAH-PSS)4 films in vascular tissue engineering fieldL'incidence des maladies cardiovasculaires d'origine athéromateuse constitue un problème majeur en santé publique et malgré le développement de techniques curatives endovasculaires, la chirurgie demeure nécessaire chez de nombreux patients. La faible disponibilité des vaisseaux naturels, autologues ou non, et les limites mécaniques et biologiques des substituts artificiels pour le remplacement des vaisseaux de petit calibre, imposent le recours à une nouvelle science : l'ingénierie vasculaire. Ce concept a émergé et évolué depuis quelques années. Il pourrait permettre de proposer de nouveaux types de substituts vasculaires synthétiques et/ou biologiques, en particulier grâce à l'utilisation de cellules souches, ouvrant d'intéressantes perspectives dans le domaine de l'ingénierie vasculaire. Le but de ce travail a été d'obtenir de manière fiable et reproductible des cellules à phénotype endothélial mature à partir de cellules souches mésenchymateuses (CSMs) issus de la gelée de Wharton (GW) du cordon ombilical et de la moelle osseuse (MO). Cependant, la différenciation de ces cellules nécessite une fonctionnalisation de la surface de culture, et notre groupe a démontré l'avantage des films multicouches de polyélectrolytes, constitués de PAH (hydrochlorure de poly(allylamine)) et de PSS (poly(styrène sulfonate)), sur l'adhésion, la prolifération et la différenciation cellulaire. Les cellules ont été cultivées sur films (PAH-PSS)4 ou sur collagène de type I (témoin), en présence de facteurs de croissance angiogéniques. La différenciation en cellules endothéliales (CEs) a été suivie par l'expression des marqueurs endothéliaux (PCR et western blot), et la fonctionnalité par leur capacité à incorporer les lipoprotéines acétylées (Ac-LDLs) ainsi que la capacité à produire du monoxyde d'azote et à exprimé le facteur von Willebrand (vWF). Après 14 jours de stimulation, seules les CSM-GWs étaient différenciées en CEs fonctionnelles démontrant l'intérêt de combiner l'utilisation des CSM-GWs et des films (PAH-PSS)4 dans le domaine de l'ingénierie vasculair