Clastogenic Factors as Potential Biomarkers of Increased Superoxide Production

The formation of clastogenic factors (CF) and their damaging effects are mediated by superoxide, since superoxide dismutase is regularly protective. CF are produced via superoxide and stimulate the production of superoxide by monocytes and neutrophils. This results in a selfsustaining and longlasting process of clastogenesis, which may exceed the DNA repair system and ultimately lead to cancer (Emerit, 1994). An increased cancer risk is indeed observed in conditions accompanied by CF formation. These include irradiated persons, patients with chronic inflammatory diseases, HIV-infected persons and the chromosomal breakage syndromes ataxia telangiectasia, Bloom’s syndrome and Fanconi’s anemia. Biochemical analysis has identified lipid peroxidation products, arachidonic acid metabolites, nucleotides of inosine and cytokines, in particular tumor necrosis factor alpha, as the clastogenic and also superoxide stimulating components of CF. Due to their chromosome damaging effects, these oxidants can be detected with classical cytogenetic techniques. Their synergistic action renders the CF-test particularly sensitive for the detection of a pro-oxidant state. Correlations were observed between CF and other biomarkers of oxidative stress such as decreases in total plasma thiols or increases in TBARS or chemiluminescence. Correlations between CF and disease activity, between CF and radiation exposure, suggest the study of CF for monitoring these conditions. CF may also be useful as biochemical markers and intermediate endpoints for the evaluation of promising antioxidant drugs

Affordances et matérialité dans les publications fantômes sur Facebook

Les affordances de certaines formes technolangagières (Paveau 2012) interrogent le rapport à la matérialité des énoncés tels qu’ils apparaissent dans les environnements numériques. C’est le cas de ce que nous appelons les « publications fantômes » sur Facebook. Énoncés translucides qui n’existent que pour l’utilisateur tant qu’il n’a pas cliqué sur le bouton « publier ». Cet article proposera une définition des publications fantômes s’appuyant sur une typologie diachronique réunie à partir d’un micro-corpus constitué depuis leur apparition sur le site en 2015. Cette typologie nous permettra de considérer l’augmentation des affordances et leur utilisation stratégique par Facebook.Affordances of technolanguage forms (Paveau 2012) question the relation to the materiality of statements as they appear in digital environments. This is the case of what we call "ghost publications" on Facebook. Translucent statements that only exist for the user as long as they have not clicked on the "publish" button. This article will propose a definition of the ghost publications based on a diachronic typology from a micro-corpus constituted since their appearance on the site in 2015. This typology will allow us to consider the increase of the affordances and their strategic use by Facebook

Neuroprotective activity of Hypericum perforatum and its major components

Hypericum perforatum is a perennial plant, with worldwide distribution, commonly known as St. Johns wort. It has been used for centuries in traditional medicine for the treatment of several disorders, such as minor burns, anxiety, and mild to moderate depression. In the past years, its antidepressant properties have been extensively studied. Despite that, other H. perforatum biological activities, as its neuroprotective properties have also been evaluated. The present review aims to provide a comprehensive summary of the main biologically active compounds of H. perforatum, as for its chemistry, pharmacological activities, drug interactions and adverse reactions and gather scattered information about its neuroprotective abilities. As for this, it has been demonstrated that H. perforatum extracts and several of its major molecular components have the ability to protect against toxic insults, either directly, through neuroprotective mechanisms, or indirectly, through is antioxidant properties. H. perforatum has therefore the potential to become an effective neuroprotective therapeutic agent, despite further studies that need to be carried out.This work was supported by Fundacao para a Ciencia e Tecnologia (FCT), projects PTDC/AGR-ALI/105169/2008, PEst-OE/AGR/UI4033/2014. AO was supported by Escola Superior de Tecnologia da Saude do Porto and Instituto Politecnico do Porto (Programa de Formacao Avancada de Docentes).info:eu-repo/semantics/publishedVersio

Cerium Oxide Nanoparticles Protect Cardiac Progenitor Cells from Oxidative Stress

Cardiac progenitor cells (CPCs) are a promising autologous source of cells for cardiac regenerative medicine. However, CPC culture in vitro requires the presence of microenvironmental conditions (a complex array of bioactive substance concentration, mechanostructural factors, and physicochemical factors) closely mimicking the natural cell surrounding in vivo, including the capability to uphold reactive oxygen species (ROS) within physiological levels in vitro. Cerium oxide nanoparticles (nanoceria) are redox-active and could represent a potent tool to control the oxidative stress in isolated CPCs. Here, we report that 24 h exposure to 5, 10, and 50 !g/mL of nanoceria did not a!ect cell growth and function in cardiac progenitor cells, while being able to protect CPCs from H2O2-induced cytotoxicity for at least 7 days, indicating that nanoceria in an e!ective antioxidant. Therefore, these "ndings con"rm the great potential of nanoceria for controlling ROS-induced cell damage

Estrategia de educación en desarrollo sustentable para el nivel medio superior tecnológico en México

A partir del análisis de la incorporación de contenidos de temática ambiental en los planes y programas de estudio del bachillerato tecnológico, así como de la verificación de contenidos ambientales abordados en el aula, y la observación del grado de preocupación ambiental mostrado por los estudiantes y profesores del Centro de Estudios Tecnológicos del Mar No. 27, en Puerto Vicente, Guerrero, México, se presenta una estrategia educativa de formación para el desarrollo sustentable aplicable al nivel medio superior, bajo el esquema de la reforma educativa implantada recientemente. La propuesta se compone de tres áreas: pedagógica-curricular; organizativa y administrativa; y comunitaria y de participación social. La falta de una estructura curricular, que permita la inserción educativa del desarrollo sustentable, suscribe la propuesta de su abordaje en el desarrollo de competencias ambientales situadas, con apoyo en la elección, organización y solución de problemáticas ambientales cercanas a la vida cotidiana del estudiante y su desagregación para su tratamiento en clase en: situaciones ambientales sociales, situaciones ambientales económicas y situaciones ambientales naturales

Aging and Gene Expression in the Primate Brain

It is well established that gene expression levels in many organisms change during the aging process, and the advent of DNA microarrays has allowed genome-wide patterns of transcriptional changes associated with aging to be studied in both model organisms and various human tissues. Understanding the effects of aging on gene expression in the human brain is of particular interest, because of its relation to both normal and pathological neurodegeneration. Here we show that human cerebral cortex, human cerebellum, and chimpanzee cortex each undergo different patterns of age-related gene expression alterations. In humans, many more genes undergo consistent expression changes in the cortex than in the cerebellum; in chimpanzees, many genes change expression with age in cortex, but the pattern of changes in expression bears almost no resemblance to that of human cortex. These results demonstrate the diversity of aging patterns present within the human brain, as well as how rapidly genome-wide patterns of aging can evolve between species; they may also have implications for the oxidative free radical theory of aging, and help to improve our understanding of human neurodegenerative diseases

Antioxidant Effects of the Ethanol Extract from Flower of Camellia japonica via Scavenging of Reactive Oxygen Species and Induction of Antioxidant Enzymes

The aim of this study was to investigate the antioxidant properties of the ethanol extract of the flower of Camellia japonica (Camellia extract). Camellia extract exhibited 1,1-diphenyl-2-picrylhydrazyl radical and intracellular reactive oxygen species (ROS) scavenging activity in human HaCaT keratinocytes. In addition, Camellia extract scavenged superoxide anion generated by xanthine/xanthine oxidase and hydroxyl radical generated by the Fenton reaction (FeSO4 + H2O2) in a cell-free system, which was detected by electron spin resonance spectrometry. Furthermore, Camellia extract increased the protein expressions and activity of cellular antioxidant enzymes, such as superoxide dismutase, catalase and glutathione peroxidase. These results suggest that Camellia extract exhibits antioxidant properties by scavenging ROS and enhancing antioxidant enzymes. Camellia extract contained quercetin, quercetin-3-O-glucoside, quercitrin and kaempferol, which are antioxidant compounds