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	Reactive oxygen species - Wikipedia, the free encyclopedia
		Reactive oxygen species (ROS) include oxygen ions, free radicals and peroxides both inorganic and organic.
		They are generally very small molecules and are highly reactive due to the presence of unpaired valence shell electrons.
		Reactive oxygen species are implicated in cellular activity to a variety of inflammatory responses including cardiovascular disease.
	en.wikipedia.org /wiki/Reactive_oxygen_species (453 words)

	Journal of Carcinogenesis \| Full text \| Reactive oxygen species: role in the development of cancer and various chronic ...
		Oxygen derived species such as superoxide radical, hydrogen peroxide, singlet oxygen and hydroxyl radical are well known to be cytotoxic and have been implicated in the etiology of a wide array of human diseases, including cancer.
		Reactive oxygen species (ROS) are derived from the metabolism of molecular oxygen [3].
		The role of reactive oxygen species in cell growth regulation is complex, being cell specific and dependent upon the form of the oxidant as well as the concentration of the particular reactive oxygen species.
	www.carcinogenesis.com /content/5/1/14 (4693 words)

	News & Features: Thiols of cysteines and how organisms defend against reactive oxygen species
		Reactive oxygen species can damage cells in many ways: by inactivating proteins, damaging nucleic acids, and altering the fatty acids of lipids, which leads in turn to perturbations in membrane structure and function.
		It is postulated that tissue injury by these reactive oxygen species accumulates over a long period of time and plays roles in the aging process and the development of heart disease, diabetes, chronic inflammatory diseases, cancer, and several neurodegenerative diseases (Halliwell 1999).
		For ease of study in the laboratory, the stress responses are often provoked by the external addition of chemical oxidants that specifically elevate the levels of reactive oxygen species within cells, or by the use of mutant strains that disrupt the normal “homeostatic mechanisms” for removing reactive oxygen species or the damage they do.
	www.iscid.org /boards/ubb-get_topic-f-1-t-000194.html (854 words)

	Reactive Oxygen Species and Antioxidant Vitamins, The Linus Pauling Institute, Oregon State University
		In aerobic organisms like humans, oxygen is converted to water at the end of the respiratory chain in the mitochondria.
		Radicals usually are very reactive species, because electrons like to pair up to form stable two-electron bonds (a landmark discovery made many decades ago by Linus Pauling, culminating in his Nobel Prize in Chemistry in 1954).
		The recent, though as yet unconfirmed, evidence that excess iron intake may be linked to increased risk of heart disease and cancer may, in part, be explained by the role iron plays in the conversion of superoxide to hydroxyl radicals, resulting in oxidative damage to arteries and genes.
	lpi.oregonstate.edu /f-w97/reactive.html (1556 words)

	Speaking of Radicals Part II: Reactive Oxygen Species
		The oxygen molecule does not have an odd number of electrons, but it does have two "lone" electrons in separate orbitals and can be thought of as being two "odd" electrons.
		As we just discussed, the oxygen molecule is a di-radical, and thus it should be written as O2.., with the two dots representing lone non-paired electrons.
		In this case, although you could have the cigarette tar semiquinone radical reduce oxygen to make superoxide and superoxide then cause the reduction of ferric ions, it actually is the cigarette tar free radical itself that is the culprit.
	www.drpasswater.com /nutrition_library/pryor_part_2.html (1666 words)

	Invitrogen - Molecular Probes - Section 18.2 - Generating and Detecting Reactive Oxygen Species
		Although there are no equilibrium sensors that continuously monitor the level of reactive oxygen species, this section discusses a number of probes that trap or otherwise react with singlet oxygen, hydroxyl radicals or superoxide.
		Singlet oxygen is responsible for much of the physiological damage caused by reactive oxygen species, including nucleic acid modification through selective reaction with deoxyguanosine.
		In the presence of singlet oxygen, however, it emits a green fluorescence similar to that of fluorescein (excitation/emission maxima ~504/525 nm).
	probes.invitrogen.com /handbook/sections/1802.html (7322 words)

	Generation of reactive oxygen species by the faecal matrix -- Owen et al. 46 (2): 225 -- Gut
		Reactive oxygen species are implicated in the aetiology of a range of human diseases and there is increasing interest in their
		of the inhibitory capacity of phytate on reactive oxygen species
		Chemiluminescence assay of mucosal reactive oxygen metabolites in inflammatory bowel disease.
	gut.bmjjournals.com /cgi/content/full/46/2/225 (4727 words)

	Reproductive Biology and Endocrinology \| Full text \| Reactive oxygen species and sperm cells
		On the other hand, low (physiological) levels of lipid peroxidation reflect the influence of reactive oxygen species (ROS) on sperm metabolism enhancing the ability of human spermatozoa to interact with zona pellucida [1].
		Reactive oxygen species therefore may have been implicated as an etiological factor of a very wide range of diseases [2-15].
		Concentration of dissolved oxygen is defined by oxygen electrode when measuring uptake of oxygen by carbon-centered radicals and during peroxide decomposition reactions.
	www.rbej.com /content/2/1/12 (4103 words)

	Reactive Oxygen Species Regulate Oxygen-sensitive Potassium Flux in Rainbow Trout Erythrocytes -- Bogdanova and ...
		of reactive oxygen species and not to the reaction of MPG with
		Bunn, H.F., and Poyton, R.O. Oxygen sensing and molecular adaptation to hypoxia.
		Duranteau, J., Chandel, N.S., Kulisz, A., Shao, Z.H., and Schumacker, P.T. Intracellular signaling by reactive oxygen species during hypoxia in cardiomyocytes.
	www.jgp.org /cgi/content/full/117/2/181 (5054 words)

	Reactive Oxygen Species
		It is the most reactive of them all; note how it differs from the hydroxyl ion (#4).
		Reactive oxygen species are formed by several different mechanisms:
		The transformed cells were returned to the patients, took up residence in their bone marrow, proliferated successfully, and improved their symptoms.
	home.comcast.net /~john.kimball1/BiologyPages/R/ROS.html (908 words)

	Reactive oxygen species and tendinopathy: do they matter? -- Bestwick and Maffulli 38 (6): 672 -- British Journal of ...
		Human fibroblasts release reactive oxygen species in response to interleukin-1 or tumour necrosis factor-alpha.
		Nishio E, Watanabe Y. The involvement of reactive oxygen species and arachidonic acid in alpha(1)-adrenoceptor-induced smooth muscle cell proliferation and migration.
		The contribution of reactive oxygen species to sarcopenia and muscle ageing.
	bjsm.bmj.com /cgi/content/full/38/6/672 (1495 words)

	Fluorescence Helps Measure Reactive Oxygen Species in Cigarette Smoke (Site not responding. Last check: 2007-10-10)
		The connection between smoking and these diseases is oxidative stress, a condition in which lipids, proteins and DNA are damaged by the reactive oxygen species, such as nitric dioxide and peroxyl radicals, that are found in cigarette smoke.
		To fully understand the effect that the reactive oxygen species have on smokers and to help find ways to reduce the harm caused by them, investigators must accurately measure their quantity within cigarette smoke.
		Unfortunately, this labor-intensive method is selectively reactive with some radicals and not sensitive at all to peroxyl radicals, which are the most prominent reactive species in cigarette smoke.
	www.photonics.com /content/spectra/2006/June/applications/82882.aspx (799 words)

	Free Radicals
		A prominent feature of radicals is that they have extremely high chemical reactivity, which explains not only their normal biological activities, but how they inflict damage on cells.
		Reactive oxygen species are also formed as necessary intermediates in a variety of enzyme reactions.
		Despite their beneficial activities, reactive oxygen species clearly can be toxic to cells.
	arbl.cvmbs.colostate.edu /hbooks/pathphys/misc_topics/radicals.html (1070 words)

	Reactive oxygen species are critical mediators of coronary collateral development in a canine model -- Gu et al. 285 ...
		Reactive oxygen species are critical mediators of coronary collateral development in a canine model -- Gu et al.
		Role of reactive oxygen species in bradykinin-induced mitogen-activated protein kinase and c-fos induction in vascular cells.
		The mechanism of cytoprotective action of lazaroids I: inhibition of reactive oxygen species formation and lethal cell injury during periods of energy depletion.
	ajpheart.physiology.org /cgi/content/full/285/4/H1582 (4568 words)

	REACTIVE OXYGEN SPECIES AND ELECTRON EXCITATION IN AQUEOUS SYSTEMS: TWO SIDES OF THE COIN (via CobWeb/3.1 ... (Site not responding. Last check: 2007-10-10)
		Alexander Gurwitsch was the first to consider and experimentally demonstrate the crucial role of oxygen and its reactive species in the emerging of mitogenetic radiation.
		Thus there is a serious contradiction between traditional views upon ROS as only deleterious chemical species and factual evidence of a demand for them of all the living organisms and of their highly specific regulatory action upon vital processes.
		Energy released in these reactions is used, as mentioned, as an activation energy for the specific biochemical processes, for the continuous pumping of the non-equilibrium state of inter- and intracellular structural components, while the structural patterns of ROS reactions determine biochemical and physiological rhythmic modes.
	www.biophotonen-online.de.cob-web.org:8888 /abstract/abs2000-18.htm (840 words)

	Contribution of Reactive Oxygen and Nitrogen Species to Particulate-Induced (Site not responding. Last check: 2007-10-10)
		These reactive species are formed as intermediates in mitochondrial electron transport systems and microsomal metabolism of endogenous compounds and xenobiotics, including drugs and environmental pollutants and various cytoplasmic sources.
		Third, under conditions of ischemia, decreased perfusion, low oxygen tension, or trauma, xanthine dehydrogenase, the innocuous form of the enzyme, is converted to xanthine oxidase, which uses xanthine and molecular oxygen to produce partially reduced oxygen species.
		Evidence for the involvement of reactive oxygen species in the pathogenesis of asbestos-induced injury is the upregulation of antioxidant enzyme gene expression and induction of antioxidant enzyme activity.
	www.ehponline.org /members/1998/Suppl-5/1157-1163zhu/zhu-full.html (5965 words)

	ScienceDaily: Reactive Oxygen Species Shown Essential For Development Of Inner Ear's Balance Machinery (Site not responding. Last check: 2007-10-10)
		Reactive Oxygen Generated By Nox1 Enzyme Triggers Angiogenesis (January 23, 2002) -- An enzyme called Nox1, which converts oxygen into "reactive oxygen," is a potent trigger of angiogenesis, according to research by scientists at Emory University School of Medicine and Harvard...
		Oxygen" Ed McCabe's follow-up to his best-seller Oxygen Therapies, and is the seminal work on the subject and encompasses its' entirety.
		The first edition of this workbook is regarded as a classic in its field, and was the first book to introduce trigger point therapy to the general public as a self-care tool for alleviating chronic...
	www.sciencedaily.com /releases/2006/01/060123164905.htm (1729 words)

	Reactive Oxygen Species and Aging: Evolving Questions -- Dugan and Quick 2005 (26): pe20 -- Science's SAGE KE
		Reactive Oxygen Species and Aging: Evolving Questions -- Dugan and Quick 2005 (26): pe20 -- Science's SAGE KE Jump to: Page Content, Section Navigation, Site Navigation, Site Search, Account Information, or Site Tools.
		Abstract: Over the past 50 years, reactive oxygen species (ROS) have been investigated as putative mediators of the process of aging.
		As specific genes and pathways that are involved with ROS homeostasis have been linked to aging in lower organisms, such as Caenorhabditis elegans and Drosophila, the questions of how ROS regulate aging in higher organisms, and whether they do so to the same extent as in lower organisms, have emerged.
	sageke.sciencemag.org /cgi/content/abstract/2005/26/pe20 (286 words)

	Superoxide/Reactive Oxygen Species Determination Kit - WPI
		Luminol reacts with superoxide and other reactive oxygen species resulting in a luminophore that has an emission peak at ~425 nm.
		The intensity of the chemiluminescence is proportional to the amount of superoxide or reactive oxygen species in the sample.
		When the other reactive oxygen species are mostly derived from superoxide, this assay provides an indirect measure of cellular superoxide production.
	www.superoxide-wpi.com (357 words)

	Audiology Online: Reactive Oxygen Species Shown Essential for Development of Inner Ear's Balance Machinery (Site not responding. Last check: 2007-10-10)
		Reactive oxygen species (ROS) are normally produced as a product of metabolism, and, as their name implies, they are highly reactive with surrounding biological components.
		The ability of ROS to damage DNA and other critical molecules underlies their reputation for causing deleterious cellular effects and their association with aging, carcinogenesis, and atherosclerosis.
		These findings indicate that reactive oxygen species produced at the right place at the right time can have a constructive developmental role, in contrast to their previously known toxic effects.
	www.audiologyonline.com /news/displaynews.asp?news_id=1993 (452 words)

	Oxidizing Free Radicals and Reactive Oxygen Species (ROS) (Site not responding. Last check: 2007-10-10)
		It is kinda a chain reaction as well, and a bit runaway unless natural antioxidants (including Microhydrin®) are present to donate electrons and satiate (and neutralize) the horny promiscuous ROS molecules.
		Rusting is a form of oxidation: oxygen or some other reactive species (atom, ion or molecule) steals an electron, changing the original substance.
		Blending is a rather violent action that whips milloins of tiny air (containing oxygen) bubbles into the substance, while also, at the same time destroying any integrity of the whole which protected the contents (the eggshell is gone, the fruit skin is removed, etc.), from the air (and oxygen).
	www.rawpaleodiet.org /ros-1.html (976 words)

	ScienceDaily: Anti-aging Hormone Reduces Reactive Oxygen Species
		Now, a new study shows that this protein acts by increasing the cell's ability to detoxify harmful reactive oxygen species.
		Polyphenol antioxidant -- A polyphenol antioxidant is a type of antioxidant characterized by the presence of several phenol functions.
		Radical (chemistry) -- In chemistry, radicals (often referred to as free radicals) are atomic or molecular species with unpaired electrons on an otherwise open shell configuration.
	www.sciencedaily.com /releases/2005/11/051104085003.htm (1804 words)

	Reactive oxygen species - Glossary Entry - Genetics Home Reference
		Molecules or ions formed by the incomplete one-electron reduction of oxygen.
		These reactive oxygen intermediates include singlet oxygen; superoxides; peroxides; hydroxyl radical; and hypochlorous acid.
		They contribute to the microbicidal activity of phagocytes, regulation of signal transduction and gene expression, and the oxidative damage to nucleic acids; proteins; and lipids.
	ghr.nlm.nih.gov /ghr/glossary/reactiveoxygenspecies (79 words)

	FAQs
		How many harmful reactive oxygen species exist in the body?
		There are 6 common harmful reactive oxygen or nitrogen species existing in the body.
		Halliwell, B. Reactive Oxygen Species in Living Systems - Source, Biochemistry, and Role in Human-Disease.
	www.brunswicklabs.com /harmful_species.shtml (199 words)

	Focus Issue: Reactive Oxygen Species--Friend or Foe? -- Gough 2006 (332): eg6 -- Science's STKE
		Summary: Science’s STKE focuses on the signaling pathways activated in response to pathological accumulation of reactive oxygen species (ROS), as well as on mechanisms by which cells have harnessed these reactive molecules as active participants in signaling that leads to a desirable cellular response.
		ROS are chemically reactive because they contain unpaired electrons and, depending on the location of their production and the molecules with which they interact, they can cause cellular damage or trigger specific signaling events.
		Indeed, kinases and phosphatases are now recognized as key molecules that can be modified by interaction with ROS, and the Protocol by Wu and Terada describes a method for detecting oxidatively modified protein tyrosine phosphatases.
	stke.sciencemag.org /cgi/content/abstract/stke.3322006eg6 (317 words)

	Fight Aging!: Aging and Reactive Oxygen Species, Some Science
		Via transhumantech, some pointers from researcher Joao Magalhaes on longevity and damaging reactive oxygen species (ROS, including the much maligned free radicals).
		Read the whole thing, but here's the bottom line from his point of view: This seems to support the idea that ROS are not just damaging compounds, but essential biological molecules used in a myriad of functions.
		Please note that comments incorporating ad hominem attacks, advertising and other forms of inappropriate behavior are likely to be deleted.
	www.fightaging.org /archives/000654.php (513 words)

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