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

Mechanochemical synthesis of diimide based electron acceptors for organic photovoltaics applications

It has been predicted that solar energy will play a key role in solving the serious environmental problems that face our planet. The pursuit of clean, renewable, cost-effective, and high-performance organic photovoltaic (OPV) technologies has attracted considerable efforts from both academia and industry. Some of the most promising materials for OPVs are those based on systems such as naphthalene diimide (NDI), or perylene diimide (PDI). These structures are known to be excellent electron acceptor species for organic electronic applications because of their strong light absorption and chemical stability. However, the efficient synthesis of these compounds is hindered by poor yields and the need for harsh solvent-based conditions, especially for their brominated derivatives. This report details our efforts towards synthesising these high value compounds in a more environmentally friendly way using solvent free mechanochemistry in a ball mill. With these molecules synthesised, our long-term goal is to study their solid-state polymerisation resulting in an environmentally benign synthesis of materials suitable for the next generation of organic solar cells

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

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

Biotelemetric Monitoring of Brain Neurochemistry in Conscious Rats Using Microsensors and Biosensors

In this study we present the real-time monitoring of three key brain neurochemical species in conscious rats using implantable amperometric electrodes interfaced to a biotelemetric device. The new system, derived from a previous design, was coupled with carbon-based microsensors and a platinum-based biosensor for the detection of ascorbic acid (AA), O2 and glucose in the striatum of untethered, freely-moving rats. The miniaturized device consisted of a single-supply sensor driver, a current-to-voltage converter, a microcontroller and a miniaturized data transmitter. The redox currents were digitized to digital values by means of an analog-to-digital converter integrated in a peripheral interface controller (PIC), and sent to a personal computer by means of a miniaturized AM transmitter. The electronics were calibrated and tested in vitro under different experimental conditions and exhibited high stability, low power consumption and good linear response in the nanoampere current range. The in-vivo results confirmed previously published observations on striatal AA, oxygen and glucose dynamics recorded in tethered rats. This approach, based on simple and inexpensive components, could be used as a rapid and reliable model for studying the effects of different drugs on brain neurochemical systems