Antibacterial and dermal toxicological profiles of ethyl acetate extract from Crassocephalum bauchiense (Hutch.) Milne-Redh (Asteraceae)

<p>Abstract</p> <p>Background</p> <p>The emergence in recent years of numerous resistant strains of pathogenic bacteria to a range of formerly efficient antibiotics constitutes a serious threat to public health. <it>Crassocephalum bauchiense</it>, a medicinal herb found in the West Region of Cameroon is used to treat gastrointestinal infections as well as liver disorders. The ethyl acetate extract from the leaves of <it>C. bauchiense </it>was evaluated for its antibacterial activity as well as acute and sub-acute toxicities.</p> <p>Methods</p> <p>The plant extract was prepared by maceration in ethyl acetate. Its phytochemical screening was done by standard methods. The broth microdilution method was used to evaluate the <it>in vitro </it>antibacterial activity. The <it>in vivo </it>antibacterial activity of a gel formulation (0.05, 1 and 2% w/v) of this extract was evaluated using a <it>Staphylococcus aureus</it>-induced dermatitis in a murine model. Selected haematological and biochemical parameters were used to evaluate the dermal sub-acute toxicity of the extract in rats.</p> <p>Results</p> <p>Phytochemical screening of the <it>C. bauchiense </it>extract revealed the presence of alkaloids, phenols, tannins and sterols. <it>In vitro </it>antibacterial activities were observed against all the tested microorganisms (MIC = 0.04-6.25 mg/ml). Formulated extract-gel (2% w/v) and gentamycin (reference drug) eradicated the microbial infection after five days of treatment. A single dermal dose of this extract up to 32 g/kg body weight (bw) did not produce any visible sign of toxicity. Also, daily dermal application of the <it>C. bauchiense </it>extract gel formulation for 28 days did not show any negative effect, instead some biochemical parameters such as alanine aminotransferase (ALT and AST), low density lipoprotein (LDL), high density lipoprotein (HDL) and triglycerides were significantly (p < 0.05) affected positively.</p> <p>Conclusion</p> <p>These results indicate that the <it>C. bauchiense </it>ethyl acetate extract can be used safely for the treatment of some bacterial infections.</p

Le retailing et ses environnements

National audienc

3D Ultrasound Elastography for Early Detection of Lesions. Evaluation on a Pressure Ulcer Mimicking Phantom

International audienceA pressure ulcer is a damaged tissue area induced by an unrelieved pressure compressing the tissue during a prolonged period of immobility. The lack of information and studies on the development of this pathology makes its prevention difficult. However, it is both acknowledged that lesions initiate in the deep muscular tissues before they expand to the skin, and that lesions are harder than healthy tissues. Elastography is therefore an interesting tool for an early detection of the pathology. A 3D strain estimation algorithm is presented and evaluated on a PVA-cryogel phantom, mimicking a pressure ulcer at an early stage

Effects of short-term normobaric hypoxia on haematology, muscle phenotypes and physical performance in highly trained athletes

This study aimed to determine the impact of short-term normobaric hypoxia on physiology and performance in highly trained athletes. Twelve (7 male and 5 female) athletes were randomly assigned into two groups and spent 8 h per night for two consecutive nights a week over 3 weeks under either short-term normobaric hypoxia (simulating 3636 m altitude, inspired O2= 13%) or in normobaric normoxia in a single-blind study. Following a 3 week washout period, athletes were then exposed to the other condition. Athletes were tested for maximal oxygen consumption and time to exhaustion on an electromagnetically braked cycle ergometer before and after each treatment in addition to being tested for anaerobic performance (Wingate test) on a modified Monark cycle ergometer. Blood samples were taken throughout the experiment and vastus lateralis muscle biopsies were taken before and after each treatment. Increases in red blood cell count, haematocrit, haemoglobin, platelet number and erythropoietin concentration were observed following short-term normobaric hypoxia. Except for a modest decrease in phosphofructokinase activity following short-term normobaric hypoxia, no changes were observed in muscle enzyme activities, buffer capacity, capillary density or morphology. No performance measures were changed following short-term normobaric hypoxia or normobaric normoxia. Although short-term normobaric hypoxia exposure increased levels of a number of haematological parameters, this was not associated with improved aerobic or anaerobic performance in highly trained athletes

On the potential of ultrasound elastography for pressure ulcer early detection.

International audiencePURPOSE: Pressure ulcers are areas of soft tissue breakdown induced by a sustained mechanical stress that damages the skin and underlying tissues. They represent a considerable burden to the society in terms of health care and cost. Yet, techniques for prevention and detection of pressure ulcers still remain very limited. In this article, the authors investigated the potential of ultrasound elastography for pressure ulcer early detection. Elastography is an imaging technique providing local information on biological tissue mechanical properties. It is relevant for pressure ulcer detection as this pathology is associated with a gradual stiffening of damaged tissues, beginning in the deeper tissues and progressing toward the skin surface. METHODS: A 2D ultrasound elastography method was proposed and its ability in terms of pressure ulcer detection was validated through numerical simulations and physical acquisitions on pressure ulcer mimicking phantoms. In vivo experiments on a rat model are also reported. A maintained pressure was applied on the animal thigh, with a view to generate a pressure ulcer, and ultrasound data were acquired and processed before and after application of this pressure. RESULTS: Numerical simulations demonstrated that a pressure ulcer can theoretically be detected at a very early stage with ultrasound elastography. Even when the ulcer region was characterized by a low stiffening (ratio of 1.8 relative to normal tissues), the corresponding elastogram clearly underlined the pathological area. This observation was confirmed by the results obtained on a physical phantom mimicking a pressure ulcer at an early stage. Computed elastograms showed strain differences between areas mimicking healthy and pathological tissues. Results corresponding to in vivo experiments revealed a difference in the way tissues behaved before and after the pressure was applied on the animal thigh, which strongly suggests the presence of a pathological area. CONCLUSIONS: Experiments demonstrated that ultrasound elastography is a promising technique for pressure ulcer detection, especially at an early stage of the pathology, when the disease is still visually undetectable. In the absence of any gold standard method, this is also a first step toward the development of a quantitative technique

Camus, l'artiste

Albert Camus se définissait comme artiste, plus que comme écrivain. Même s'il a exercé avec talent bien d'autres « métiers », c'est dans la création – qui passe pour lui par l'édification d'un langage – qu'il tente de faire son « métier d'homme » de la manière la plus accomplie. Il réfléchit sur l'art dès ses écrits de jeunesse et il n'interrompra jamais cette méditation. Elle prend la forme de commentaires théoriques sur les fonctions de l'art et sur la responsabilité de l'artiste, où l'exigence éthique est constamment présente. Elle mène aussi à une maturation secrète par laquelle s'approfondit sa vocation d'artiste. C'est ce rapport de Camus à l'art que nous avons voulu explorer : à son art, aux artistes, à d'autres arts en particulier, à l'art en général. Les contributions qui forment ce volume font appel à l'ensemble de l'œuvre de Camus, y compris des textes peu connus, dont elles dévoilent la pertinence ; leurs auteurs viennent de quatre continents et couvrent quatre générations de chercheurs – unis par la conviction que, sans que soient réduites les autres facettes de son expérience existentielle, la dimension esthétique est centrale dans l'être-au-monde de Camus. Ce livre intéressera, bien sûr, ceux qui veulent en apprendre davantage sur Albert Camus et en découvrir un pan méconnu, mais aussi ceux qui veulent approfondir la réflexion esthétique et la théorie sur l'art

Collaborations et réseaux

Les liens entre les concepts de « collaborations » et de « réseaux » sont étroits. Car si la collaboration peut avoir lieu hors d'un réseau, elle nous semble aussi (et surtout) être une dimension constitutive du réseau. Par exemple, les clients et les fournisseurs sont en relations, mais ils ne vont constituer un réseau que lorsqu'ils vont mettre en place une forme de collaboration entre eux. Plus généralement, il y a réseau lorsque la coordination entre les organisations ou les hommes qui les composent ne se fait pas uniquement par les prix comme le suppose la théorie économique standard. C'est en cela que cet ouvrage est ancré dans les sciences de gestion. Les réseaux seront donc caractérisés par la plus ou moins grande place accordée à la coordination hiérarchique ; elle peut être assez forte dans les réseaux de distribution ayant des magasins en propre, elle est plus faible dans les réseaux de franchise ou de sous-traitance, elle devient quasiment nulle dans les réseaux de PME. L'objectif de cet ouvrage collaboratif, écrit par vingt-sept enseignants-chercheurs de l'IGR- IAE de Rennes (université Rennes 1), est de faire découvrir le thème « collaborations et réseaux », sous ses différentes facettes, à un large public. Il se destine à un lectorat qui ne se restreint pas aux enseignants-chercheurs des universités, des IAE et des écoles de commerce. Il s'adresse également aux étudiants, aux dirigeants, aux cadres d'entreprise, et pourquoi pas aux curieux