L-Glutamine therapy reduces endothelial adhesion of sickle red blood cells to human umbilical vein endothelial cells

BACKGROUND: We have previously demonstrated that therapy with orally administered L-glutamine improves nicotinamide adenosine dinucleotide (NAD) redox potential of sickle red blood cells (RBC). On further analysis of L-glutamine therapy for sickle cell anemia patients, the effect of L-glutamine on adhesion of sickle RBC to human umbilical vein endothelial cells (HUVEC) was examined. METHODS: The first part of the experiment was conducted with the blood samples of the 5 adult sickle cell anemia patients who had been on L-glutamine therapy for at least 4 weeks on a dosage of 30 grams per day compared to those of patient control group. In the second part of the experiment 6 patients with sickle cell anemia were studied longitudinally. Five of these patients were treated with oral L-glutamine 30 grams daily and one was observed without treatment as the control. t-test and paired t-test were used for determination of statistical significance in cross-sectional and longitudinal studies respectively. RESULTS: In the first study, the mean adhesion to endothelial cells with the autologous plasma incubated cells were 0.97 ± 0.45 for the treated group and 1.91 ± 0.53 for the nontreated group (p < 0.02). Similarly with lipopolysaccharide (LPS) incubated cells the mean adhesion to endothelial cells were 1.39 ± 0.33 for the treated group and 2.80 ± 0.47 for the untreated group (p < 0.001). With the longitudinal experiment, mean decrease in the adhesion to endothelial cells was 1.13 ± 0.21 (p < 0.001) for the 5 treated patients whereas the control patient had slight increase in the adhesion to endothelial cells. CONCLUSION: In these studies, oral L-glutamine administration consistently resulted in improvement of sickle RBC adhesion to HUVEC. These data suggest positive physiological effects of L-glutamine in sickle cell disease

Desferrioxamine decreases NAD redox potential of intact red blood cells: evidence for desferrioxamine as an inducer of oxidant stress in red blood cells

BACKGROUND: Desferrioxamine (DFO) is an important iron chelating agent. It has also been thought of as an agent with anti-oxidant potential as it chelates ferric iron in various parts of the body. However, there is evidence suggesting that it may paradoxically affect red blood cells (RBC) by inducing intracellular oxidant stress. To further understand the mechanism of DFO's interaction with RBC, we conducted a study to determine the effect of DFO upon RBC's redox status. METHODS: We examined NAD redox potential in intact RBC (N = 5) incubated with DFO. RBC were incubated with 6 mM DFO for 2 hours. RESULTS: Significant decreases in NAD redox potential were observed after incubation of RBC with 6 mM DFO. The mean decrease was 10.01 ± 1.98% (p < 0.0004). CONCLUSIONS: The data confirm the oxidant effect of DFO on RBC

Control of mitochondrial pH by uncoupling protein 4 in astrocytes promotes neuronal survival.

Brain activity is energetically costly and requires a steady and highly regulated flow of energy equivalents between neural cells. It is believed that a substantial share of cerebral glucose, the major source of energy of the brain, will preferentially be metabolized in astrocytes via aerobic glycolysis. The aim of this study was to evaluate whether uncoupling proteins (UCPs), located in the inner membrane of mitochondria, play a role in setting up the metabolic response pattern of astrocytes. UCPs are believed to mediate the transmembrane transfer of protons, resulting in the uncoupling of oxidative phosphorylation from ATP production. UCPs are therefore potentially important regulators of energy fluxes. The main UCP isoforms expressed in the brain are UCP2, UCP4, and UCP5. We examined in particular the role of UCP4 in neuron-astrocyte metabolic coupling and measured a range of functional metabolic parameters including mitochondrial electrical potential and pH, reactive oxygen species production, NAD/NADH ratio, ATP/ADP ratio, CO2 and lactate production, and oxygen consumption rate. In brief, we found that UCP4 regulates the intramitochondrial pH of astrocytes, which acidifies as a consequence of glutamate uptake, with the main consequence of reducing efficiency of mitochondrial ATP production. The diminished ATP production is effectively compensated by enhancement of glycolysis. This nonoxidative production of energy is not associated with deleterious H2O2 production. We show that astrocytes expressing more UCP4 produced more lactate, which is used as an energy source by neurons, and had the ability to enhance neuronal survival

Pour une théorie de la traduction (application au discours journalistique, français-arabe)

L'objectif de notre recherche est d'arriver à une réflexion théorique - qui se veut scientifique sur la traduction des textes d'actualité relevant de la presse écrite. Une telle réflexion se nourrissant d'une grande ambition d'analyser le processus de traduction dans toute sa richesse et sa complexité, de dégager les opération et les choix qu'effectue le traducteur consciemment ou inconsciemment afin de pouvoir extraire des principes qui soient utiles pour la formation des futurs traducteurs et qui leur fournissent de la materia prima les aidant à mener à bien leur tâche. D'où cette tentative de soulever la plupart des problèmes qui se posent, des questions qui doivent être soulevées. Aussi examinons-nous les grandes lignes, les principaux courants de pensée en traduction ; ce qui permettra de tracer l'évolution d'une telle pensée. Un fois que les grandes lignes de pensée en matière de traduction au vingtième siècle sont explorées, nous essayons de proposer un modèle décrivant les démarches du traducteur dans son passage d'un article rédigé dans une langue A à un autre article rédigé dans une langue B ; ce qui pourrait nous permettre de souligner également les problèmes d'ordre pratique entravant son accomplissement tels les problèmes de lexiques, de termes techniques, de structure syntaxique, de clichés, de stéréotypes, etc.The aim of our research is to get to a theorical approach, trying to be scientific, about the translation of current events texts in the written press.Such an approach is carried out by a complicated analyse process of translation in order to show all the operation and choices which the translator uses consciously and unconsciously, also to show some useful principals for the future translators providing them the materia prima to accomplish their task very well. In this respect, we try to raise some problems and to examine the principal currents of thought in translation which allow to trace the evolution of such a thought. When the rules of thought concerning the translation in the twentieth century will be examined, we try than to propose a model which describes the translator processes when he translates an article written in a language A to another article written in a language B. That could allow us also to indicate some problems that we can find in practice such as the problems of lexicons, of syntactic structure, of cliches and stereotypes.LYON2/BRON-BU (690292101) / SudocSudocFranceF

Effect of chloramphenicol and ethidium bromide on the level of ornithine carbamoyltransferase in Neurospora crassa.

The specific activity of the nuclear-gene-encoded, mitochondrial arginine biosynthetic enzyme ornithine carbamoyltransferase (EC 2.1.3.3) in Neurospora crassa was elevated in mycelia treated with chloramphenicol or ethidium bromide. The increase in specific activity was caused by an increase in the number of mature enzyme molecules rather than by the activation of a preexisting enzyme. Chloramphenicol and ethidium bromide appeared to act indirectly via arginine-mediated derepression. However, derepression did not appear to result from a drug-mediated decrease in the arginine pool