Sonic hedgehog carried by microparticles prevents angiotensin II-induced hypertension and endothelial dysfunction in mice

Microparticles (MPs) are small fragments generated from the plasma membrane after cell stimulation. Among the candidate proteins harbored by MPs, we recently showed that morphogen Sonic hedgehog is present in MPs generated from activated/apoptotic human T lymphocytes and corrects endothelial injury through nitric oxide (NO) release (Agouni et al. FASEB J 2007). The present study further investigates whether MPs bearing Shh prevent angiotensin II (Ang II)-induced hypertension and endothelial dysfunction in mice. Male Swiss mice (6–8 week old) were subcutaneously implanted with osmotic minipumps delivering Ang II (0.5 mg/kg per day) or NaCl (0.9%, control group). Systolic blood pressure and heart rate were measured daily during 21 consecutive days using tail cuff plethysmography connected to a computerized system (LE 5002 # , BIOSEB). Mice were tained for 7 days. After 7 day of minipump implantation, mice received i.v. injections of MPs (10 μg/mL) or i.p. Sonic Hedgehog receptor antagonist cyclopamine (10 mg/kg per 2 days) during 1 week prior sacrifice. Thoracic aorta was removed, cleaned of connective tissue and cut in rings (3 mm length) and mounted in a myograph to study vascular reactivity. Ang II induced a significant rise in systolic blood pressure without affecting heart rate when compared to control mice. Interestingly, MPs alone did not modify both parameters but reversed Ang II-induced hypertension. Moreover, cyclopamine prevented the effects of MPs on Ang II-induced hypertension, suggesting the involvement of a Sonic Hedgehog-dependent mechanism. In the aorta, MPs alone slightly increased the sensitivity of endothelium-dependent relaxation to acetylcholine and completely reversed the impairment of acetylcholine-induced relaxation in aorta from Ang II-infused mice. The improvement of endothelial function induced by MPs was completely prevented by cyclopamine treatment. Moreover, measurement of NO production showed that MPs alone did not modify NO production in aorta, but significantly restored its decrease in Ang II-treated mice. Altogether, these results show that MPs bearing Sonic hedgehog prevent Ang II-induced hypertension and endothelial dysfunction in aorta through a mechanism associated with Sonic hedgehog-induced NO production. These MPs may represent a new therapeutic approach in cardiovascular diseases associated with decreased NO production

Etude de l’activité antioxydante des extraits des feuilles de Vitex doniana (Verbenacea)

L’objectif de la présente étude était d’évaluer l’activité antioxydante des extraits des feuilles de Vitex doniana par spectrophotométrie en utilisant les méthodes de piégeage des radicaux libres 2,2-diphényl-1- picryl-hydrazyle (DPPH•) et acide 2,2’-azino-bis-(3-éthylbenzothiazoline-6-sulfonique) (ABTS+•). Une extraction éthanolique des feuilles de Vitex doniana a été effectuée au Soxhlet. L’extrait sec recueilli a été redissout dans de l’eau puis fractionné en utilisant successivement de l’hexane, du dichlorométhane et de l’acétate d’éthyle. Les propriétés antioxydantes de l’extrait éthanolique et celles de ses différentes fractions ont été évaluées aux concentrations de 2,5 ; 10 ; 100 et 200 μg/mL. Les pourcentages d’inhibition (PI) expriment l’effet antioxydant mesuré. L’extrait éthanolique et ses différentes fractions ont présenté une activité de piégeage des deux radicaux libres. Lors des tests d’inhibition de l’absorbance du radical DPPH•, les PI ont varié de (18,15±0,01)% pour la fraction hexanique (2,5 μg/mL) à (92,45±0,01)% pour la fraction d’acétate d’éthyle (100 μg/mL). Avec le radical ABTS+•, les PI ont varié de (52,76±0,05)% pour la fraction hexanique (2,5 μg/mL) à (98,27±0,12)% pour la fraction d’acétate d’éthyle (100 μg/mL). Ainsi, l’extrait éthanolique des feuilles de Vitex doniana et ses différentes fractions possèdent un pouvoir antioxydant significatif.Mots clés : Activité antioxydante, DPPH, ABTS, Vitex doniana

Attenuation of allergic airways inflammation by an extract of Hymenocardia acida

Tracheal hyperresponsiveness, airway mucus production and bronchoalveolar inflammation are the major components of asthma. Here, we aim to investigate the role in the control of asthma of a bioactive plant extracted from Hymenocardia acida in a physiological and pathophysiological model. The effect of H. acida crude extract (HACE) on total cellular components of bronchoalveolar (BAL) fluids was performed on ovalbumin (OVA) and lipopolysaccaride (LPS)-challenged Swiss mice for induction of allergic asthma and airways inflammation, respectively. Mice were pretreated with 0.9% sodium chloride (NaCl), HACE (oral doses at 100 mg/kg/body weight) for a week and then by intranasal instillation with OVA (0.5 mg/ml) + aluminium hydroxyde (20 mg/ml), during three days after intraperitoneally sensitization or with LPS (0.4 mg/ml) for a day (OVA or LPS + HACE). The BAL cells were collected in a mixed solution (0.9% NaCl and 2.6 mm Ethylenediaminetetraacetic acid EDTA) one day after the last challenge and total cells were numbered in a Neubauer chamber. The HACE: (i) significantly inhibited the airways inflammation induced by a single intranasal instillation of LPS or allergic asthma on mice challenged with 3 consecutive days intranasal instillation of OVA in comparison to control mice only instilled with 0.9% sterile. NaCl : (ii) significantly impaired the increased levels of total cells in OVA and LPS-treated mice, without changing the basal cellularity after NaCl or HACE treatment; (iii) and significantly inhibitshydroxyl radicalsandsuperoxideanions production. Taken together, these results suggest that HACE exposure induces a marked reduction of cellular component in the BAL fluid, which is only partially lymphocytes dependent

Détermination du débit de filtration glomérulaire (DFG) au cours du diabète : Cockroft et Gault, MDRD ou CKD-EPI ?

Plusieurs paramètres peuvent être étudiés pour évaluer le rein. Parmi ceux-ci, le débit de filtration glomérulaire (DFG) a été déterminé avec les formules de Cockroft et Gault (CG), du Modification of Diet in Renal Disease (MDRD) et du Chronic Kidney Disease EPIdemiology Collaboration (CKD-EPI) et la formule la mieux adaptée pour le diabétique a été recherchée. Chez 59 diabétiques de type 1 (DT1) et 70 diabétiques de type 2 (DT2), le DFG a été déterminé avec les formules de CG, du MDRD et du CKD-EPI. Avec l’analyse statistique, les seuils de significativité ont été fixés pour p<0,05 ; T0α>1,96 et Z0α>1,96. Le MDRD est superposable au CKD-EPI chez les DT1 et DT2. Chez les DT1, le DFG moyen et la corrélation entre 1/créatininémie et DFG ne varient pas si CG ou CKD-EPI ; cependant, les sujets à DFG réduit (< 90 ml/min/1,73 m²) sont plus nombreux avec CG plutôt qu’avec CKD-EPI (66,10% vs 47,46% ; T0α=2,05). Chez les DT2, le DFG moyen et la proportion de sujets à DFG réduit sont indépendants de la formule utilisée, mais la corrélation entre 1/créatininémie et DFG est plus forte si CKD-EPI que CG (0,961 vs 0,632 ; Z0α=7,02). Ainsi, la formule la mieux adaptée pour la détermination du DFG serait CG chez les DT1 et CKD-EPI chez les DT2, sachant que CKD-EPI est équivalent à MDRD quel que soit le type de diabète.Mots clés : Cockroft et Gault - MDRD - CKD-EPI – débit de filtration glomérulaire (DFG) – diabète

Sonic Hedgehog Carried by Microparticles Corrects Angiotensin II-Induced Hypertension and Endothelial Dysfunction in Mice

Microparticles are small fragments of the plasma membrane generated after cell stimulation. We recently showed that Sonic hedgehog (Shh) is present in microparticles generated from activated/apoptotic human T lymphocytes and corrects endothelial injury through nitric oxide (NO) release. This study investigates whether microparticles bearing Shh correct angiotensin II-induced hypertension and endothelial dysfunction in mice. Male Swiss mice were implanted with osmotic minipumps delivering angiotensin II (0.5 mg/kg/day) or NaCl (0.9%). Systolic blood pressure and heart rate were measured daily during 21 days. After 7 day of minipump implantation, mice received i.v. injections of microparticles (10 µg/ml) or i.p. Shh receptor antagonist cyclopamine (10 mg/kg/2 days) during one week. Angiotensin II induced a significant rise in systolic blood pressure without affecting heart rate. Microparticles reversed angiotensin II-induced hypertension, and cyclopamine prevented the effects of microparticles. Microparticles completely corrected the impairment of acetylcholine- and flow-induced relaxation in vessels from angiotensin II-infused mice. The improvement of endothelial function induced by microparticles was completely prevented by cyclopamine treatment. Moreover, microparticles alone did not modify NO and O2. - production in aorta, but significantly increased NO and reduced O2. - productions in aorta from angiotensin II-treated mice, and these effects were blocked by cyclopamine. Altogether, these results show that microparticles bearing Shh correct angiotensin II-induced hypertension and endothelial dysfunction in aorta through a mechanism associated with Shh-induced NO production and reduction of oxidative stress. These microparticles may represent a new therapeutic approach in cardiovascular diseases associated with decreased NO production

Using systematic screening to increase integration of reproductive health services delivery in Senegal

This study tested the systematic screening technique to increase the integration of reproductive health services in Senegal. The study took place in four urban health posts in the city of Dakar and three rural health posts in the district of Kebemer. A before and after design tested the hypothesis that the use of the systematic screening tool would result in more services received per client visit. In Dakar, services per visit increased significantly by 20 percent, while in Kebemer, services per visit also increased significantly by 35 percent. The study also examined several techniques to improve provider compliance with the screening technique. The Senegal Ministry of Health has requested assistance in scaling up the strategy to other reproductive health service delivery points at district, regional, and national levels