Some definitions are in order as usual before plunging into this abstract:
What the heck is drosophila melansogaster? Fruit fly!
Drosophila melanogaster (Greek for dark-bellied dew lover : δρόσος = dew, φίλος = intimate friend, lover, μέλας = dark-coloured, γαστήρ = belly) is a species of Diptera, or the order of flies, in the family Drosophilidae. The species is commonly known as the common fruit fly or vinegar fly. Starting from Charles W. Woodworth, this species is one of the most commonly used model organisms in biology, including studies in genetics, physiology, microbial pathogenesis and life history evolution because they are easy to take care of, breed quickly, and lay many eggs.
You might ask why I reprinted this after reading it so let me tell you why up front. As you know from previous work and studies that have been reprinted here, there have been nore than enough questions raised about whether in fact the current alleged non toxic chromium 3 is nothing more than chromium 6 (Toxic form) oxidized to chromium 3. One example of this can be found in its entirety at this link: http://www.mydepuyhiprecall.com/2011/03/mechanisms-of-chromium-toxicity.html
There is good evidence from the clinic and the laboratory that Cr[VI] is the ion responsible for most of the toxic actions, although much of the underlying molecular damage may be due to its intracellular reduction to the even more highly reactive and short-lived chemical species Cr[III] and Cr[V]. Exposure to Cr[VI] can result in various point mutations in DNA and to chromosomal damage, as well as to oxidative changes in proteins and to adduct formation. The relative importance of these effects of chromium ions and of the free oxidising radicals they may generate in the body in causing tumours and allergic sensitisation remain to be demonstrated. Biochemical studies of the DNA-damaging effects and of the pathogenesis of the allergic reactions to chromium ions have not kept up with advances in understanding of the molecular basis of the effects of other carcinogens and allergens.
Another definition is in order as well prior to reading this doc:
DNA repair refers to a collection of processes by which a cell identifies and corrects damage to the DNA molecules that encode its genome. In human cells, both normal metabolic activities and environmental factors such as UV light and radiation can cause DNA damage, resulting in as many as 1 million individual molecular lesions per cell per day. Many of these lesions cause structural damage to the DNA molecule and can alter or eliminate the cell's ability to transcribe the gene that the affected DNA encodes. Other lesions induce potentially harmful mutations in the cell's genome, which affect the survival of its daughter cells after it undergoes mitosis. As a consequence, the DNA repair process is constantly active as it responds to damage in the DNA structure. When normal repair processes fail, and when cellular apoptosis does not occur, irreparable DNA damage may occur, including double-strand breaks and DNA crosslinkages.
The rate of DNA repair is dependent on many factors, including the cell type, the age of the cell, and the extracellular environment. A cell that has accumulated a large amount of DNA damage, or one that no longer effectively repairs damage incurred to its DNA, can enter one of three possible states:
- an irreversible state of dormancy, known as senescence
- cell suicide, also known as apoptosis or programmed cell death
- unregulated cell division, which can lead to the formation of a tumor that is cancerous
ok here you go!