Etat de l'art / Sources
In this 2nd issue, you will find a new contribution dealing with the way to present a review of the literature. Supplementary exercises along with a bilingual version of the texts presented in the paper version are available in this online version.
On this site, you can also find the translation of the key expressions, two short videos corresponding to the topics covered in this issue and an audio file for the pronunciation of tricky words.
Dans ce nouveau numéro, vous trouverez une nouvelle contribution présentant la manière de faire une revue de la littérature. Des exercices complémentaires ainsi qu’une version bilingue des textes de la version papier sont disponibles dans cette version en ligne. Sur ce site, vous trouverez également la traduction des expressions essentielles, deux courtes vidéos correspondant aux thèmes abordés dans ce numéro et un fichier audio correspondant à la prononciation des mots difficiles.
I’ll be coming back to resveratrol shortly, but I’d like to begin by talking about the good and bad sides of oxygen .
Oxygen is vital for life in many species , including humans , but oxygen is a highly toxic substance and organisms that need oxygen to survive have developed ways to protect themselves from its harmful effects. One of the most widely used defence systems in the natural world is provided by the enzyme heme oxygenase 1 or HO-1.
The basic role of this enzyme is simply to break down heme to generate biliverdin, carbon monoxide and free iron . In doing this, HO-1 contributes to antioxidant defences.
In fact, as reported by Mc Cann et al. in 1987, the biliverdin generated in this reaction is rapidly converted to a powerful antioxidant, bilirubin, which is then converted back into biliverdin through interactions with reactive oxygen species, such as oxygen ions and peroxides. These ROS, which are mopped up, or more correctly, scavenged , in this reaction can cause considerable damage to cell structures.
Oxidative damage is a major factor in many human diseases, including cardiovascular disease and diabetes , but is also instrumental in various physiological functions. For example, low levels of reactive oxygen species are necessary for various biochemical processes including defence against pathogenic microorganisms , as shown by John Kendal and colleagues in 2002.
Cells thus need to control levels of ROS without eliminating them entirely .
HO-1 is thus a key player in antioxidant defences, and the expression of this enzyme is upregulated via the nuclear factor –erythroid-2 factor 2 or Nrf2 pathway, and certain phytochemicals , including resveratrol are known to upregulate HO-1 expression via this pathway. So, resveratrol can boost antioxidant defences.
Click on the orange words to hear how they are pronounced.
Cliquer sur les mots en orange pour entendre leur prononciation.
Click on the following links to watch two short videos :
Cliquer sur les liens suivants pour voir deux courtes vidéos :
*Professeurs d’anglais médical à l’université de Dijon
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