Évaluation de l’impact du rejet des déchets phosphates dans la mer sur la biodiversité marine dans trois localités côtières au Togo à partir des biomarqueurs du stress oxydatif chez Sphyraena barracuda (HECKEL, 1843)

La pollution due aux rejets des déchets phosphatés à Kpémé par la Société Nouvelle des Phosphates du Togo (SNPT), concerne aussi les zones environnantes. Nous avons voulu dans ce travail déterminer l’impact de cette pollution dans ces zones sur la biodiversité marine. Les teneurs en métaux lourds toxiques (Cd et Pb) dans les organes de poissons à Gbodjomé (zone de référence), Agbodrafo, Goumoukopé et Aného sont déterminées par spectrophotométrie d’absorption atomique à la flamme ; de même que certains biomarqueurs du stress oxydatif. Dans l’ensemble, les résultats ont montré une altération des enzymes antioxydantes, du système de la glutathion et une induction de la peroxydation lipidique due à la présence du Cd et du Pb qui provoquent un stress oxydatif chez les poissons, et donc chez les espèces de la biodiversité marine de la côte togolaise des zones concernées. Les résultats de la présente étude indiquent que les zones environnantes sont touchées par le rejet des déchets à Kpémé et les impacts sur la biodiversité marine diminuent au fur et à mesure qu’on s’éloigne des sites de rejets vers l’aval à cause du sens d’écoulement de la mer. Aussi, peut-on déduire que les biomarqueurs du stress oxydatif sont des indicateurs de la pollution aquatique.Mots clés: Déchets phosphatés, pollution, Cd, Pb, bioaccumulatio

Developing cardiac and skeletal muscle share fast-skeletal myosin heavy chain and cardiac troponin-I expression

Skeletal muscle derived stem cells (MDSCs) transplanted into injured myocardium can differentiate into fast skeletal muscle specific myosin heavy chain (sk-fMHC) and cardiac specific troponin-I (cTn-I) positive cells sustaining recipient myocardial function. We have recently found that MDSCs differentiate into a cardiomyocyte phenotype within a three-dimensional gel bioreactor. It is generally accepted that terminally differentiated myocardium or skeletal muscle only express cTn-I or sk-fMHC, respectively. Studies have shown the presence of non-cardiac muscle proteins in the developing myocardium or cardiac proteins in pathological skeletal muscle. In the current study, we tested the hypothesis that normal developing myocardium and skeletal muscle transiently share both sk-fMHC and cTn-I proteins. Immunohistochemistry, western blot, and RT-PCR analyses were carried out in embryonic day 13 (ED13) and 20 (ED20), neonatal day 0 (ND0) and 4 (ND4), postnatal day 10 (PND10), and 8 week-old adult female Lewis rat ventricular myocardium and gastrocnemius muscle. Confocal laser microscopy revealed that sk-fMHC was expressed as a typical striated muscle pattern within ED13 ventricular myocardium, and the striated sk-fMHC expression was lost by ND4 and became negative in adult myocardium. cTn-I was not expressed as a typical striated muscle pattern throughout the myocardium until PND10. Western blot and RT-PCR analyses revealed that gene and protein expression patterns of cardiac and skeletal muscle transcription factors and sk-fMHC within ventricular myocardium and skeletal muscle were similar at ED20, and the expression patterns became cardiac or skeletal muscle specific during postnatal development. These findings provide new insight into cardiac muscle development and highlight previously unknown common developmental features of cardiac and skeletal muscle. © 2012 Clause et al

Circulating Angiopoietin-2 as a Biomarker in ANCA-Associated Vasculitis

The endothelial-specific Angiopoietin-Tie2 ligand-receptor system is an important regulator of endothelial activation. Binding of angiopoietin-2 (Ang-2) to Tie2 receptor renders the endothelial barrier responsive to pro-inflammatory cytokines. We previously showed that circulating Ang-2 correlated with disease severity in a small cohort of critically ill patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated glomerulonephritis. The current study reassessed Ang-2 as a biomarker of disease activity and relapse in AAV. Circulating Ang-2 was measured in 162 patients with severe AAV (BVAS/WG≥3, with or without glomerulonephritis) in a clinical trial. Ang-2 levels during active AAV were compared to levels in the same patients during remission (BVAS/WG = 0). Levels in clinical subsets of AAV were compared, and association with future disease course was assessed. Ang-2 levels were elevated in severe disease (median 3.0 ng/ml, interquartile range 1.9–4.4) compared to healthy controls (1.2, 0.9–1.5). However, they did not reliably decline with successful treatment (median 2.6 ng/ml, interquartile range 1.9–3.8, median change −0.1). Ang-2 correlated weakly with BVAS/WG score (r = 0.17), moderately with markers of systemic inflammation (r = 0.25–0.41), and inversely with renal function (r = −0.36). Levels were higher in patients with glomerulonephritis, but levels adjusted for renal dysfunction were no different in patients with or without glomerulonephritis. Levels were higher in patients with newly diagnosed AAV and lower in patients in whom treatment had recently been started. Ang-2 levels during active disease did not predict response to treatment, and Ang-2 levels in remission did not predict time to flare. Thus, Ang-2 appears to have limited practical value in AAV as a biomarker of disease activity at time of measurement or for predicting future activity

In Vitro Cell Models for Ophthalmic Drug Development Applications

© Sara Shafaie et al. 2016; Published by Mary Ann Liebert, Inc. This Open Access article is distributed under the terms of the Creative Commons License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited.Tissue engineering is a rapidly expanding field that aims to establish feasible techniques to fabricate biologically equivalent replacements for diseased and damaged tissues/organs. Emerging from this prospect is the development of in vitro representations of organs for drug toxicity assessment. Due to the ever-increasing interest in ocular drug delivery as a route for administration as well as the rise of new ophthalmic therapeutics, there is a demand for physiologically accurate in vitro models of the eye to assess drug delivery and safety of new ocular medicines. This review summarizes current existing ocular models and highlights the important factors and limitations that need to be considered during their use.Peer reviewe

Comprehensive Molecular Characterization of Pheochromocytoma and Paraganglioma

SummaryWe report a comprehensive molecular characterization of pheochromocytomas and paragangliomas (PCCs/PGLs), a rare tumor type. Multi-platform integration revealed that PCCs/PGLs are driven by diverse alterations affecting multiple genes and pathways. Pathogenic germline mutations occurred in eight PCC/PGL susceptibility genes. We identified CSDE1 as a somatically mutated driver gene, complementing four known drivers (HRAS, RET, EPAS1, and NF1). We also discovered fusion genes in PCCs/PGLs, involving MAML3, BRAF, NGFR, and NF1. Integrated analysis classified PCCs/PGLs into four molecularly defined groups: a kinase signaling subtype, a pseudohypoxia subtype, a Wnt-altered subtype, driven by MAML3 and CSDE1, and a cortical admixture subtype. Correlates of metastatic PCCs/PGLs included the MAML3 fusion gene. This integrated molecular characterization provides a comprehensive foundation for developing PCC/PGL precision medicine

Evaluation du potentiel bioprotecteur des champignons mycorhiziens arbusculaires contre les nematodes phytoparasites et les insectes ravageurs du riz au Togo

Les insectes et les nématodes constituent une entrave à la production du riz. L'utilisation des Champignons Mycorhiziens Arbusculaires (CMA) serait une option non seulement de gestion efficiente de la fertilité des sols mais aussi de contrôle de ces ravageurs. Le but de cette étude a été donc de tester l'efficacité des CMA sur la réduction de la densité des nématodes et sur la dynamique des insectes ravageurs du riz. L'expérience a consisté à inoculer sur sol stérilisé des semences de riz en pépinière avec quatre souches de CMA (Acaulospora spinosa, Ben 10, Glomus mosseae et de G. hoï) testées à trois doses d’inoculation (7,82 x 105; 3,91 x 105 et 1,96 x 105 spores/ha). Les plants non fertilisés et non mycorhizés (témoin absolu) et les plants fertilisés aux engrais chimique NPK 15 15 15 et Urée 46% N à la dose recommandée de 200 kg/ha et 100 kg/ha (témoin relatif), ont servi de témoins. Les résultats ont montré des corrélations négatives significatives entre la fréquence de mycorhization et la production de panicules non fertiles et une corrélation négative entre l’intensité de mycorhization des racines et la densité de nématodes aussi bien dans les racines que dans le sol. La symbiose mycorhizienne entre les CMA et les plants de riz n'ont pas empêché les insectes d'infester les plants mycorhizés. Toutefois l‘incidence des attaques des insectes a été significativement réduite sur les plants inoculés comparés aux plants sans mycorhizes ni engrais chimique. Les mycorhizes auraient permis en effet aux plants mycorhizés de mieux tolérer les attaques des insectes ravageurs comparés aux plants témoins.Il ressort de cette étude que les CMA seraient une bonne alternative aux nématicides et insecticides chimiques de synthèse dans la gestion des ravageurs en production rizicole. Les résultats sont discutés dans un esprit de l’utilisation des Champignons Mycorhiziens Arbusculaires comme stratégie de gestion écologique durable des bioagresseurs des cultures.Mots clés: Riz, champignons mycorhiziens arbusculaires, insectes ravageurs, nématodes phytoparasites, gestion écologique durableEnglish Title: Evaluation of the bioprotection potential of mycorrhizal arbuscular fungi against plant parasitic nematodes and insect pests of rice in TogoEnglish AbstractInsects and nematodes are an impediment to rice production. The use of Arbuscular Mycorrhizal Fungus (AMF) would be an option not only for the efficient management of soil fertility but also for the control of insect pests and plant parasitic nematodes. The aim of this study was to test the effectiveness of AMF in reducing nematode density and the insect pest damages. The experiment consisted in inoculating rice seeds on sterilized soil in nursery with four strains of AMF (Acaulospora spinosa, Ben 10, Glomus mosseae and G. hoï) tested at three spore concentrations (7,82 x 105 spores, 3.91 x 105 spores and 1.96 x 105 spores/ha). Plots planted with non-inoculated rice seedling that did not received any fertilizer (absolute control) and plots with plant fertilized with NPK 15 15 15 and Urea 46% N at the recommended rate of 200kg/ha and 100kg/ha, were used as controls. The results showed significant negative correlations between the frequency of mycorhization and non-fertile panicle production, and a negative correlation between root mycorrhizal intensity and nematode density both in the roots and soil. The mycorrhizal symbiosis between tested AMF and rice plants did not prevent insects from infesting inoculated plants. However, incidence of insect attack was significantly lower in inoculated plants compared to plants without AMF or chemical fertilizer. The AMF might have allowed inoculated plants to more tolerate the attacks of insect pests compared to non-inoculated one.It appears from this study that AMF could be a good alternative to synthetic nematicides and chemical insecticides in pest management in rice production. The results are discussed in the terms of using Arbuscular Mycorrhizal Fungi as a strategy for sustainable ecological management of crop pests.Keywords: Rice, Arbuscular Mycorrhizal Fungi, insect pests, plant parasitic nematodes, sustainable ecological managemen

Brevetoxin derivatives that inhibit toxin activity

Background: The brevetoxins are marine neurotoxins that interfere with the normal functions of the voltage-gated Na + channel. We have identified two brevetoxin derivatives that do not exhibit pharmacological properties typical of the brevetoxins and that function as brevetoxin antagonists. Results: PbTx-3 and benzoyl-PbTx-3 elicited Na + channel openings during steady-state depolarizations; however, two PbTx-3 derivatives retained their ability to bind to the receptor, but did not elicit Na + channel openings. α-Naphthoyl-PbTx-3 acted as a PbTx-3 antagonist but did not affect Na + channels that were not exposed to PbTx-3. β-Naphthoyl-PbTx-3 reduced openings of Na + channels that were not exposed to PbTx-3. Conclusions: Some modifications to the brevetoxin molecule do not alter either the binding properties or the activity of these toxins. Larger modifications to the K-ring sidechain do not interfere with binding but have profound effects on their pharmacological properties. This implies a critical function for the K-ring sidechain of the native toxin