Differential Regulation of the Production of Reactive Oxygen Species in Th1 Cytokine–Treated Thyroid Cells

BACKGROUND: Th1 cytokines exert pleiotropic effects in Hashimoto's thyroiditis. Previous studies reported a downregulation of thyroperoxidase and dual oxidase (DUOX) protein and mRNA expression in thyroid cells treated with Th1 cytokines. Although this effect is partially mediated by intracellular reactive oxygen species (ROS) and reactive nitrogen species, the nature and the source of the ROS involved are currently unknown. The aim of this study was to examine further the nature and source of the ROS produced in response to Th1 cytokines. METHODS: Two rat thyroid cell lines (PCCL3 and FRTL-5) and human thyrocytes were incubated with Th1 cytokines (interleukin [IL]-1α and interferon-γ) in the presence or absence of the Th2 cytokine IL-4, the nitric oxide synthase inhibitor N-nitroso-L-arginine methyl ester (L-NAME), or the synthetic antioxidant N-acetylcysteine. The nature and source of the intracellular and extracellular ROS produced were determined. RESULTS: A rapid increase in intracellular ROS was observed in cells incubated with Th1 cytokines. This increase was not caused by extracellular hydrogen peroxide (H2O2) produced by DUOX because both DUOX expression and extracellular H2O2 synthesis were decreased by Th1 cytokines. Confocal colocalization experiments showed that the Th1 cytokine-triggered ROS were not produced from mitochondria. Electron paramagnetic resonance investigations of PCCL3 cells indicated that the highly reactive hydroxyl radical was not involved in the response to Th1 cytokines. NOX2 mRNA expression was significantly increased in PCCL3 cells incubated with Th1 cytokines, as was the expression of the protein in the thyroid of Hashimoto's thyroiditis patients. NOX4 expression was by contrast unaffected. These results suggest that at least superoxide could be produced after exposure of thyroid cells to Th1 cytokines. The effects of L-NAME and IL-4, both of which partially or totally reverse Th1 cytokine-induced effects, on ROS release were also analyzed. L-NAME and IL-4 significantly reduced the Th1 cytokine-induced surge of intracellular ROS in PCCL3 and human thyroid cells. CONCLUSION: The data presented here reinforce the idea that ROS, other than extracellular H2O2 produced by DUOX, are released from NOX2 after exposure of thyroid cells to Th1 cytokines. ROS/reactive nitrogen species act as important, but as further explained, not exclusive intracellular mediators of Th1 cytokine-induced effects in thyroid cells

Les pratiques préventives en médecine générale: comparaison de trois échantillons de praticiens de première ligne.

info:eu-repo/semantics/publishe

A model for analysis, systemic planning and strategic synthesis for health science teaching in the Democratic Republic of the Congo: a vision for action.

BACKGROUND: The problem of training human resources in health is a real concern in public health in Central Africa. What can be changed in order to train more competent health professionals? This is of utmost importance in primary health care. METHODS: Taking into account the level of training of secondary-level nurses in the Democratic Republic of the Congo (DRC), a systemic approach, based on the PRECEDE PROCEED model of analysis, led to a better understanding of the educational determinants and of the factors favourable to a better match between training in health sciences and the expected competences of the health professionals. This article must be read on two complementary levels: one reading, focused on the methodological process, should allow our findings to be transferred to other problems (adaptation of a health promotion model to the educational sphere). The other reading, revolving around the specific theme and results, should provide a frame of reference and specific avenues for action to improve human resources in the health field (using the results of its application in health science teaching in the DRC). RESULTS: The results show that it is important to start this training with a global and integrated approach shared by all the actors. The strategies of action entail the need for an approach taking into account all the aspects, i.e. sociological, educational, medical and public health. CONCLUSIONS: The analysis of the results shows that one cannot bring any change without integrated strategies of action and a multidisciplinary approach that includes all the complex determinants of health behaviour, and to do it within the organization of local structures and institutions in the ministry of health in the DRC.JOURNAL ARTICLESCOPUS: ar.jinfo:eu-repo/semantics/publishe

Le management participatif :levier pour la formation des enseignants professionnels en sciences de santé

info:eu-repo/semantics/publishe

A model for analysis, systemic planning and strategic synthesis for health science teaching in the Democratic Republic of the Congo: a vision for action

Abstract Background The problem of training human resources in health is a real concern in public health in Central Africa. What can be changed in order to train more competent health professionals? This is of utmost importance in primary health care. Methods Taking into account the level of training of secondary-level nurses in the Democratic Republic of the Congo (DRC), a systemic approach, based on the PRECEDE PROCEED model of analysis, led to a better understanding of the educational determinants and of the factors favourable to a better match between training in health sciences and the expected competences of the health professionals. This article must be read on two complementary levels: one reading, focused on the methodological process, should allow our findings to be transferred to other problems (adaptation of a health promotion model to the educational sphere). The other reading, revolving around the specific theme and results, should provide a frame of reference and specific avenues for action to improve human resources in the health field (using the results of its application in health science teaching in the DRC). Results The results show that it is important to start this training with a global and integrated approach shared by all the actors. The strategies of action entail the need for an approach taking into account all the aspects, i.e. sociological, educational, medical and public health. Conclusions The analysis of the results shows that one cannot bring any change without integrated strategies of action and a multidisciplinary approach that includes all the complex determinants of health behaviour, and to do it within the organization of local structures and institutions in the ministry of health in the DRC.</p

Expression of adiponectin, chemerin and visfatin in plasma and different tissues during a laying season in turkeys

In mammals, adipose tissue is able to secrete various hormones called adipokines including adiponectin (ADP), chemerin (Chem) and visfatin (Visf) which are involved in controlling energy metabolism as well as reproductive functions. Visf receptor is still unknown whereas ADP and Chem mainly act through AdipoR1, AdipoR2 and CMKLR1 and GPR1 receptors, respectively. No studies have yet demonstrated the presence of these three adipokines in peripheral tissues, ovarian cells or turkey plasma. Here, we investigated the expression (mRNA and protein) of ADP, Chem, Visf and their receptors in peripheral tissues and ovarian cells (granulosa and theca cells) from hierarchical follicles. Furthermore, we determined the plasma profile of ADP, Visf and Chem at different physiological stages: start, peak and end of the laying period in Meleagris gallopavo turkeys. This data was correlated with the metabolic data (plasma glucose, triglycerides, cholesterol and phospholipids).Tissue and ovarian cells mRNA and protein expression levels were determined by RT-qPCR and immunoblot, respectively. Plasma adipokines were measured by chicken ELISA and immunoblotting.In turkeys, Chem is mainly expressed in the liver while ADP and Visf are mainly expressed in the abdominal adipose tissue and pectoral muscles,respectively. As in mammals, AdipoR1 and AdipoR2 expression levels (mRNA and protein) are highly present in muscle and liver, respectively, whereas the mRNA expression of CMKLR1 and GPR1 is ubiquitous. In ovarian cells, ADP, Visf, Chem and their receptors are more highly expressed in theca cells than in granulosa cells excepted for AdipoR1. Furthermore, we found that plasma levels of ADP, Chem and Visf were reduced at the end of the laying period compared to the start of this period. At the plasma levels, the levels of these adipokines are strongly negatively correlated with glucose and only plasma Chem is negatively correlated with cholesterol, triglycerides and phospholipids.In turkeys, ADP, Visf and Chem and their receptors are expressed in peripheral tissues and ovarian cells. Plasma concentration of ADP, Visf and Chem decrease at the end of laying period and only plasma Chem is negatively correlated with levels of cholesterol, triglycerides and phospholipids levels during the entire laying period

Première lumière de GRAVITY : une nouvelle ère pour l'interférométrie optique

International audienceWith the arrival of the second generation instrument GRAVITY, the Very Large Telescope Interferometer (VLTI) has entered a new era of optical interferometry. This instrument pushes the limits of accuracy and sensitivity by orders of magnitude. GRAVITY has achieved phase-referenced imaging at approximately milliarcsecond (mas) resolution and down to ~ 100-microarcsecond astrometry on objects that are several hundred times fainter than previously observable. The cutting-edge design presented in Eisenhauer et al. (2011) has become reality. This article sketches out the basic principles of the instrument design and illustrates its performance with key science results obtained during commissioning: phase-tracking on stars with K ~ 10 mag, phase-referenced interferometry of objects fainter than K ≳ 17 mag, minute-long coherent integrations, a visibility accuracy of better than 0.25 %, and spectro-differential phase and closure phase accuracy better than 0.5 degrees, corresponding to a differential astrometric precision of a few microarcseconds (μas).Avec l'arrivée de l'instrument de deuxième génération GRAVITY, qui repousse les limites de précision et de sensibilité en interférométrie optique de plusieurs ordres de magnitude, le très grand interféromètre de l'Observatoire Européen Austral (ESO/VLTI) est entré dans une nouvelle ère. GRAVITY a réalisé des images en référence de phase avec une résolution de l'ordre de la milli-seconde d'arc et des mesures astrométriques avec une précision atteignant 100 micro-secondes sur des objets plusieurs centaines de fois moins brillants qu'observable précédemment. Le concept de pointe, présenté dans [Eisenhauer, F. et al., The Messenger, 143, 16 (2011)] est devenu réalité. Cet article esquisse les principes de base de l'instrument et illustre ses performances avec les résultats scientifiques clé obtenus pendant les tests de mise en service : asservissement en phase sur des étoiles de magnitude K=10, imagerie en référence de phase sur des objets de magnitude supérieure à K=17, intégrations cohérentes de l'ordre de la minute, précision de mesure de visibilité inférieure à 0,25%, et précision de mesure sur les phases de clôture ou spectro-différentielles meilleure que 0,5 degrés, ce qui correspond à une précision astrométrique différentielle de quelques micro-arcsecondes

Première lumière de GRAVITY : interférométrie optique avec référence de phase pour le mode interférométrique du Très Grand Télescope européen

International audienceGRAVITY is a new instrument to coherently combine the light of the European Southern Observatory Very Large Telescope Interferometer to form a telescope with an equivalent 130 m diameter angular resolution and a collecting area of 200 m2. The instrument comprises fiber fed integrated optics beam combination, high resolution spectroscopy, built-in beam analysis and control, near-infrared wavefront sensing, phase-tracking, dual-beam operation, and laser metrology. GRAVITY opens up to optical/infrared interferometry the techniques of phase referenced imaging and narrow angle astrometry, in many aspects following the concepts of radio interferometry. This article gives an overview of GRAVITY and reports on the performance and the first astronomical observations during commissioning in 2015/16. We demonstrate phase-tracking on stars as faint as mK ≈ 10 mag, phase-referenced interferometry of objects fainter than mK ≈ 15 mag with a limiting magnitude of mK ≈ 17 mag, minute long coherent integrations, a visibility accuracy of better than 0.25%, and spectro-differential phase and closure phase accuracy better than 0.5°, corresponding to a differential astrometric precision of better than ten microarcseconds (μas). The dual-beam astrometry, measuring the phase difference of two objects with laser metrology, is still under commissioning. First observations show residuals as low as 50 μas when following objects over several months. We illustrate the instrument performance with the observations of archetypical objects for the different instrument modes. Examples include the  Galactic center supermassive black hole and its fast orbiting star S2 for phase referenced dual-beam observations and infrared wavefront sensing, the high mass X-ray binary BP Cru and the active galactic nucleus of PDS 456 for a few μas spectro-differential astrometry, the T Tauri star S CrA for a spectro-differential visibility analysis, ξ Tel and 24 Cap for high accuracy visibility observations, and η Car for interferometric imaging with GRAVITY.GRAVITY est un nouvel instrument permettant la recombinaison interférométrique des télescopes du VLT (Very Large Telescope) de l'ESO (European Southern Observatory) pour former un télescope avec une limite de résolution équivalente à un diamètre 130 m et une surface collectrice de 200 m². L'instrument inclut un dispositif en optique intégré alimenté par fibre pour recombinaison des faisceaux, un spectromètre à haute résolution, des dispositifs intégrés d'analyse et de contrôle, un analyse de surface d'onde en infrarouge (IR) proche, un suiveur de frange, un mode double champ et une métrologie laser. GRAVITY fait office de précurseur en introduisant en interférométrie optique/IR les techniques de référence de phase et d'astrométrie à faible champ, inspirées des concepts développés en radio-interférométrie. Cet article donne un aperçu de GRAVITY et rend compte des performances et des premières observations astronomiques lors de la mise en service en 2015/16. Nous démontrons le suivi de phase sur des étoiles aussi faible que mK ≈ 10 mag, l'interférométrie par référence de phase sur des objets plus faibles que mK ≈ 15 mag avec une magnitude limite de mK ≈ 17 mag, des intégrations cohérentes pendant une minute, une précision de mesure de visibilité meilleure que 0,25%, et une précision sur la mesure des phases différentielles spectrales ou des clôtures de phase meilleure que 0,5 °, correspondant à une précision astrométrique différentielle meilleure que dix microsecondes d'arc (μas). L'astrométrie à double champ, mesurant la différence de phase entre deux objets avec métrologie laser, est encore en cours de test. Les premières observations montrent des résidus aussi bas que 50 μas en suivant des objets sur plusieurs mois. Nous illustrons la performance de l'instrument avec les observations d'objets archétypiques pour les différents modes d'instrument. Les exemples comprennent le trou noir supermassif du centre galactique et son étoile S2 en orbite rapide pour les observations à double champ avec référence de phase et analyse de front d'onde IR, l'étoile binaire massive BP Cru à émission X et le noyau galactique actif de PDS 456 pour quelques cas de spectro-astrométrie différentielle avec quelques μas de précision, l'étoile S CrA (de type T Tauri) pour une analyse spectro-différentielle de visibilité, les étoiles ξ Tel et 24 Cap pour des observations de visibilité de haute précision, et η Car pour une imagerie interférométrique avec GRAVITY