Reactive oxygen spedes

Pulskamp, K., Diabate, S., and Krug, H.F. (2007) Carbon nanotubes show no sign of acute toxidty but induce intracellular reactive oxygen spedes in dependence on contaminants. Toxicology Letters, 168 (1), 58-74. 

Keller, J.N., Hanni, K.B., Markesbery, W.R., 1999, Oxidized low-density hpoprotein induces neuronal death impheations for calcium, reactive oxygen spedes, and caspases, Neurochem, 72 2601-2609. 

Ko, S., Kwok, T.T., Eung, K.P., Choy, Y.M., Lee, C.Y., and Kong, S.K., 2000, Slow rise of Ca2-l- and slow release of reactive oxygen spedes are two cross-talked events important in tumour necrosis factor-alpha-mediated apoptosis. Free Radio. Res. 33 295-304. 

Figure 1. The free energy of different reactive oxygen spedes [7],...

Penning, T.M., Ohnishi, S.T., Ohnishi, T., and Harvey, R.G. (1996) Generation of reactive oxygen spedes during the enzymatic oxidation of polycyclic aromatic hydrocarbon trans-dihydrodiols catalyzed by dihydrodiol dehydrogenase. Chem. Res. Toxicol, 9, 84-92. 

In addition to the differing affinity of metals towards DNA, the steric structure of DNA bases is crucially important in all reactions with metals. In addition, an indirect mechanism of interaction with DNA is that of reactive oxygen spedes (ROS) and free radical generation, as well as depurina-tion which, in the cell, is detectable as alkali-labile sites. The existence of apurinic sites eventually can lead to strand breaks via cleavage of AP endonucleases. 

Reactive Oxygen Species Reactive intermediate oxygen spedes including both radicals and non-radicals. These substances are constantly formed in the human body and have been shown to kill bacteria and inactivate proteins, and have been impHcated in a number of diseases. Sdentific data exist that Hnk the reactive oxygen spedes produced by inflammatory phagocytes to cancer development. [NIH]... 

HSCs need hypoxic niche to proted them from oxidative stress because reactive oxygen spedes induce p38-MAPK-mediated proliferation leading to HSC exhaustion [105]. Some CSCs may also be concealed in hypoxic microenvironments, which are common in solid tumors. Given that hypoxia seems to be important in maintaining CSCs, this provides an opportunity for tumor-selective therapy. Hypoxia-inducible factor 1 (HIF-1) is stabilized under hypoxic conditions and promotes survival of cancer cells in hypoxic niches, so several strategies to inactivate HIF-1 are currently under investigation at the preclinical level [106,107]. 

Activation of the promutagen/carcinogen benzo[a]p)rrene by reactive oxygen spedes/Uver P-450 (S-9) fraction and reaction of benzo[a]pyrene epoxydiol with DNA. GSH = glutathione, DNA = deoxyribonucleic acids, X = a general nucleophile not specifically explicated. 

In Rat2 fibroblasts silica particles stimulated intracellular reactive oxygen spedes generation, evidenced by 2 ,7 -dichlorofiuorecein oxidation (Cho et al. 1999). The time course of elevation of the in-... 

Methionine can be oxidised by reactive oxygen spedes, fatty acid hydroperoxides and oxidised polyphenols. The primary oxidation product, methionine sulfoxide (free or bound in proteins), is a frequent component of various proteins. The contents of methionine sulfoxide in protein sources used for foods and feeds usually vary from 0 to 30% of the total methionine content (e.g. up to 11% methionine sulfoxide apparently occurs in milk powder, 13% in lean beef, 16-28% in wheat gluten and 50% in orange juice). It is fuUy available as a source of methionine as it can be reduced back to methionine by sulfoxide reductases, but the final oxidation product, methionine sulfone, is unavailable as a source of methionine (Figure 2.34). The oxidation of the methyl group to... 

Bartges, J.W., Kirk, C. and Lane, F. (2004) The natural activines of cells, the role of reactive oxygen spedes, and their relation to antioxidants, nuttaceuticals, botanicals, and other biologic therapies. Veterinary Clinics of North America Small Animal Practice,... 

---