Free radicals stress

The cis-tmns lipid isomerization induced by thiols was tested in human monocytic leukemia cells, where free radical stress was induced by /-irradiation. These results offer the first evidence that tmns lipids can be formed in eukaryotic cells and confirm the damaging role of RS radicals to the integrity of cis lipid geometry. 

Sharma, M. and Buettner, G.R. Interaction of vitamin C and vitamin E during free radical stress in plasma an ESR study. Free Rad Biol. Med. 14, 649-653 (1993). 

FIGURE 4 Schematic degradation of HA under free radical stress (E. Hrabarova et. al., 2012). 

The effectiveness of antioxidant activity of 1, 4-dithioerythritol expressed as the radical scavenging capacity was studied by a rotational viscometry method [86]. L, 4-dithioerythritol widely accepted and used as an effective antioxidant in the field of enzyme and protein oxidation, is a new potential antioxidant standard exhibiting very good solubility in a variety of solvents. Fignre (8) describe effect of 1, 4-dithioerythri-tol on degradation of HA solntion nnder free radical stress [87]. 

Polyamides, like other macromolecules, degrade as a result of mechanical stress either in the melt phase, in solution, or in the soHd state (124). Degradation in the fluid state is usually detected via a change in viscosity or molecular weight distribution (125). However, in the soHd state it is possible to observe the free radicals formed as a result of polymer chains breaking under the appHed stress. If the polymer is protected from oxygen, then alkyl radicals can be observed (126). However, if the sample is exposed to air then the radicals react with oxygen in a manner similar to thermo- and photooxidation. These reactions lead to the formation of microcracks, embrittlement, and fracture, which can eventually result in failure of the fiber, film, or plastic article. 

Initiation. Free-radical initiators are produced by several processes. The high temperatures and shearing stresses required for compounding, extmsion, and molding of polymeric materials can produce alkyl radicals by homolytic chain cleavage. Oxidatively sensitive substrates can react directly with oxygen, particularly at elevated temperatures, to yield radicals. 

Essential for induction ofthe/Z-5 gene in inflammatory reactions is the binding site for nuclear factor kappa B (NF-kB). NF-kB responds to cytokines, stress, free radicals, ultraviolet irradiation, and bacterial, viral, or even parasitic antigens [2]. NF-kB stands for a family of subunits, which form homo-, and heterodimers. All NF-kB proteins share a highly conserved DNA-binding/dimerization domain called the Rel homology domain (RHD) consisting of two (3-strand core domains... 

Salo, D.C., Donovan, C.M., Davies, K.J, (1991). Hsp70 and other possible heat shock or oxidative stress proteins are induced in skeletal muscle, heart, and liver during exercise. Free Radic. Biol. Med 11,239-246. 

Price, A. Hendry, G. (1987). The significance of the tocopherols in stress survival in plants. In Free Radicals, Oxidant Stress and Drug Action, ed. C. Rice Evans, pp. 443-50. London Richelieu Press. 

Morphine and HlV-Tat increase nucrogUal-free radical production and oxidative stress possible role in cytokine regulation. J Neurochem 108 202-215... 

ROBERTS L J, MORROW J D (2000) Measurement of F2-isoprostanes as an index of oxidative stress in vivo, Free Radical Biology and Medicine, 28, 505-13. 

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