95 research outputs found

    708. Process Development of Lentiviral Vectors for Large Scale Production Using a HEK293 Producer Cell Line

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    Lentiviral vectors (LVs) are promising vectors for gene therapy. Most often, they are used to deliver a functional copy of a gene to sustainably replace a defective or missing gene. However, processes for LVs must be improved to increase the yield, facilitate the scale up and satisfy Health regulatory agencies. For these reasons, we have developed and optimized a LVs production process in serum-free medium using an inducible HEK293 producer cell line which possesses the capacity to grow in suspension culture. By adding two inducing molecules, (cumate and doxycycline) this cell line produces LVs pseudotyped with the protein G of the vesicular stomatitis virus without the need of any transfection. Our tested LV carried an expression cassette for GFP to facilitate LV quantification. To optimize the process, a design of experiment (DoE) was prepared which included the study of different culture media, high cell density production using six cell boosts commercially available and the addition of sodium butyrate, caffeine and valproic acid. We found that two cell boosts were outperforming the other cell boosts tested. At the present time, two commercial media (Hycell TransFx-H and SFM4TransFx-293 media) were our best candidates to maximize viral titer by achieving high cell density culture. In parallel, a LV carrying the cDNA for a shorter version of dystrophin (mini-dystrophin) was constructed. The truncated version of the dystrophin was produced by transient transfection in 293A cells and its presence was confirmed by western blot. We are planning to evaluate if the optimal conditions for the production of LV-GFP will be also applicable to LV-mini-dystrophin, a LV encoding a much longer transgene than GFP (0.7 kb vs 5.8 kb). This LV could be first evaluated for cell therapy in animal models and later, in patients suffering from Duchenne muscular dystrophy, where the dystrophin gene is defective and the protein is absent

    Supplementation with a Polyphenol-Rich Extract, TensLess® , Attenuates Delayed Onset Muscle Soreness and Improves Muscle Recovery from Damages After Eccentric Exercise.

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    High-intensity exercises are known to provoke delayed onset muscle soreness (DOMS). Delayed onset muscle soreness typically occurs within the first 24 h, peaks between 24 and 72 h, and can last as long as 5-7 days post-exercise. Delayed onset muscle soreness is a multifactorial process involving both mechanical and biochemical components, associated with clinical features that may limit range of motion, and athletes seek for effective recovery strategies to optimize future training sessions. TensLess® is a food supplement developed to help manage post-exercise recovery. The supplement has been investigated on 13 recreationally active athletes of both sex, during a randomized, double-blind, and crossover clinical investigation, including a 3-week washout period. The clinical investigation was based on the study of TensLess® effects for DOMS management and on the reduction of associated muscle damages following an eccentric exercise protocol. Supplementation with TensLess® induced significant decrease in DOMS perception (-33%; p = 0.008) as of the first 24 h; this was significantly correlated with a lowered release of muscle damage-associated biomarkers, namely myoglobin, creatinine, and creatine kinase, for the whole length of the recovery period. Taken together, these positive results clearly indicate that post-exercise supplementation with TensLess® may preserve myocytes and reduce soreness following eccentric exercise-induced damages, and, accordingly, significantly shorten muscle recovery.Actividad Física y Deport

    Supplementation with a Polyphenol-Rich Extract, PerfLoad®, Improves Physical Performance during High-Intensity Exercise: A Randomized, Double Blind, Crossover Trial.

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    Workout capacity is energy-production driven. To produce peak metabolic power outputs, the organism predominantly relies more on anaerobic metabolism, but this undoubtedly has a negative and limiting impact on muscle function and performance. The aim of the study was to evaluate if an innovative polyphenol-based food supplement, PerfLoad®, was able to improve metabolic homeostasis and physical performance during high-intensity exercises under anaerobic conditions. The effect of a supplementation has been investigated on fifteen recreationally-active male athletes during a randomized, double-blind and crossover clinical investigation. The Wingate test, an inducer of an unbalanced metabolism associated to oxidative stress, was used to assess maximum anaerobic power during a high-intensity exercise on a cycle ergometer. Supplementation with PerfLoad® correlated with a significant increase in total power output (5%), maximal peak power output (3.7%), and average power developed (5%), without inducing more fatigue or greater heart rate. Instead, oxidative homeostasis was stabilized in supplemented subjects. Such results demonstrated that PerfLoad® is a natural and efficient solution capable of, similarly to training benefits, helping athletes to improve their physical performance, while balancing their metabolism and reducing exercise-induced oxidative stress.Actividad Física y Deport

    Evaluation of novel HIV vaccine candidates using recombinant vesicular stomatitis virus vector produced in serum-free Vero cell cultures.

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    Acquired Immune Deficiency Syndrome (AIDS) in humans is a result of the destruction of the immune system caused by Human Immunodeficiency Virus (HIV) infection. This serious epidemic is still progressing world-wide. Despite advances in treatment, a safe and effective preventive HIV vaccine is desired to combat this disease, and to save millions of lives. However, such a vaccine is not available yet although extensive amounts of resources in research and development have been invested over three decades. In light of the recently approved Ebola virus disease vaccine based on a recombinant vesicular stomatitis virus (rVSV-ZEBOV), we present the results of our work on three novel VSV-vectored HIV vaccine candidates. We describe the design, rescue, production and purification method and evaluate their immunogenicity in mice prior to preclinical studies that will be performed in non-human primates. The production of each of the three candidate vaccines (rVSV-B6-NL4.3Env/SIVtm, rVSV-B6-NL4.3Env/Ebtm and rVSV-B6-A74Env(PN6)/SIVtm) was evaluated in small scale in Vero cells and it was found that production kinetics on Vero cells vary depending on the HIV gp surface protein used. Purified virus preparations complied with the WHO restrictions for the residual DNA and host cell protein contents. Finally, when administered to mice, all three rVSV-HIV vaccine candidates induced an HIV gp140-specific antibody response

    Honey, a Gift from Nature to Health and Beauty: A Review

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    Benefits of honey are contributed by the composition of its elements such as glucose, fructose, glucose oxidase, vitamins and phenolic compounds. For health, honey can be used to treat wounds due to the antibacterial activity conferred by the hydrogen peroxide produced by glucose oxidase in honey. Anti-inflammatory, anti-oxidant, deodorizing and tissue regeneration activities in honey also help in the wound healing process. It can also be an alternative sweetener for diabetic patients to ensure compliance to a healthy diet. Moreover, honey exerts several effects such as lowering low density lipids and increasing high density lipids, thus reducing risk of atherosclerosis. In terms of beauty, honey can be used on skin and hair. It moisturizes skin through its natural humectant properties contributed by high contents of fructose and glucose. Honey treats acne on the skin due to its antibacterial activity, anti-inflammatory action and tissue repair. The hair can benefit from honey in such a way that the hair has abundance, and becomes easier to comb. However, there have not been as many studies regarding the use of honey in skin in comparison to its use for health. Therefore, future studies on honey could research its use, action and benefits in both cosmetics and dermatology

    Natural environments, ancestral diets, and microbial ecology: is there a modern “paleo-deficit disorder”? Part I

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    Assessment of the stress corrosion cracking in a chloride medium of cables used in prestressed concrete structures by the acoustic emission technique

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    cited By 13International audienceIn this paper, two main types of corrosion, localized corrosion and stress corrosion cracking (SCC) of cables used in prestressed concrete structures, were characterized and identified by acoustic emission (AE) analysis using extracted AE parameters. A novel analysis of the AE parameters using the principal component analysis (PCA) was done to discriminate localized corrosion from SCC. First, K-mean was used as an unsupervised method, and then to validate the clustering analysis k-nearest neighbour was used as a supervised method. The correlations of the AE parameters including amplitude, counts, hits and time were also used to identify corrosion mechanisms. In addition, the corrosion process characteristics of each type were explained by applying the AE signal analysis (time-frequency). Experimental results show the ability of AE to evaluate a crack propagation rate of 10-7 m s-1 in a chloride medium. Microscopic examinations revealed a mixed mode of crack propagation, modes I (shear-like mechanism) and II (cleavage-like mechanism), characterized by a multi-terrace appearance on the fractured steel surface. © 2008 IOP Publishing Ltd

    Détection et suivi par EA de la fragilisation par l'hydrogène lors de la corrosion sous contrainte

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    Les méthodes de contrôle non destructif sont de plus en plus nombreuses et variées. La plupart d'entre elles ne permettent pas le contrôle en temps réel de l'évolution de la structure. À l'inverse de l'émission acoustique (EA). Grâce à la réception, par les capteurs placés sur la structure, d'ondes acoustiques émises par des défauts actifs, une détection et une localisation des défauts peuvent être réalisées. Naturellement, une méthode de contrôle non destructif doit être adaptée non seulement au type d'endommagement, mais aussi à la structure à surveiller. Les ouvrages d'art étudiés, dans le cadre de ce travail, sont les ponts en béton précontraint
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