Oxygen burst

The differentiation effect of lycopene was associated with elevated expression of several differentiation-related proteins, such as cell surface antigen (CD14), oxygen burst oxidase and chemotactic peptide receptors (Amir et al., 1999). Recently, it has also been reported that lycopene was also able to stimulate the differentiation marker alkaline phosphatase activity in... 

Usually, there is a small oxygen burst due to greater oxygen solubility in methanol, followed by a short lag in oxygen uptake. Depending on the condition of the substrate and the amount of enzyme, a lag may not be observed. Next, a rapid linear portion is observed, usually followed by an eventual decrease as oxygen and substrate are depleted. 

The oxygen burst of monocytes induced by ambient air particles (with the exception of oil fly ash particles) was less than the response elicited by polymorphonuclear leucocytes (Prahalad etal. 1999). The luminol-enhanced chemiluminescence response of polymorphonuclear leucocytes separated from heparinised human blood was generally increased with all washed particles, with oil fly ash and one urban air particle showing statistically significant (P <0.05) differences between dHjO-washed and unwashed particles. The luminol-enhanced chemiluminescence activity in polymorphonuclear leucocytes induced in post particles... 

Chemiluminescence initiated 40 s after the approach of the quartz particle and the cell plainly shows an electron transfer as a primary reaction. Munder and Modolell (1987) increased the sensitivity of the method by a previous stimulation of the macrophages with zymosan inducing an oxygen burst. 

In contrast to ascorbic acid and a-tocopherol amidothionophosphates did not have any prooxidative effects as measured by oxygen consumption from buffer solutions containing the drug and cupric sulphate as a source of redox-active metal ions (Ti-ROSH et al. 1996). Amidothionophosphates reduced significantly and in a dose-dependent manner the oxygen burst in human neutrophils as measured by luminol-dependent luminescence, and they also markedly depressed the killing of human fibroblasts by mixtures of glucose oxidase and streptolysin S. The toxicity of these molecules was tested by intraperitoneal injection of doses up to 1000 mg/kg to white Sabra mice. No mortality was observed 30 d after administration of up to 500 mg/kg. 

Inhibition of the serum treated zymosan-stimulated superoxide anion generation from human blood mononuclear cells preincubated for 30 min or 60 min with 0.001 mM-0.1 mM chloroquine was time- and dose-dependent (Hurst et al. 1986). The drug could not markedly influence the oxygen burst induced by phorbol-myristate-acetate, A23187 or fluoride ion, excluding a significant ef-... 

A A glowing splint thrust into oxygen bursts into a bright flame. 

The product is considered nonhazardous for international transport purposes. However, it is an oxidizing agent sensitive to decomposition by water, direct sources of heat, catalysts, etc. Decomposition is accompanied by the Hberation of oxygen and heat which can support combustion and cause pressure bursts in confined spaces. Decomposition in the presence of organic material is rapid and highly exothermic. 

A further hazard exists when eompressed air jets are used to elean maehine eomponents in workplaees flying partieles have eaused injury and blindness. Cylinders may fail if over-pressurized or weakened by the applieation of heat. Liquefied gases, e.g. butane or propane, respond more rapidly to heat than the permanent gases sueh as nitrogen or oxygen. Cylinders are normally proteeted by pressure relief valves, fusible plugs or bursting dises. 

Polymorphonuclear leucocytes (PMNs) employ a system comprising myeloperoxidase, hydrogen peroxide, and a halide factor to kill microorganisms and tumour cells. This process is sometimes loosely called the respiratory burst , which refers to the sudden rise in oxygen consumption by the phagocytosing neutrophils that is independent of the mitochondrial electron transport chain. 

In addition to the well-characterized role of iron in catalysing redox interactions, other metallic contaminants, for example, nickel, may also contribute. In vivo toxicity studies have demonstrated the capacity of nickel particulate compounds to induce tumours following intraperitoneal injection (Pott etal., 1987). Such activity is proportional to their phagocytic uptake, and to the associated respiratory burst and generation of PMN-derived reactive oxygen metabolites (ROMs), a proposed pathogenic mechanism (Evans et al., 1992a). 

Inflammatory cell phenomenon are also contributors to lipid peroxidation. Activated neutrophils may adhere to damaged endothelium and amplify traumatic, ischaemic or ischaemia-reperfiision injury. Many cyclooxygenase products of the metabolism of atachidonic acid modulate the inflammatory responses of cells. Macrophages, neutrophils and microglia are important sources of reactive oxygen at the injury site. When activated, they produce a respiratory burst that is traced to activated nicotinamide adenine dinucleotide (NADPH/NADH) oxidase. 

The mammalian immune system protects the body from infection by many complex strategies. The most vigorous defense is performed by white blood cells known as granulocytes. These cells consume oxygen in response to microbial infections. This oxidative process, called the respiratory burst, has recently been proven to produce stabilized hvDOchlorite antimicrobials (bredominantlv bv neutroDhils) and stabilized... 

A leaking valve allowed butadiene to accumulate in a pipeline exposed to an inerting gas containing up to 2% of oxygen. Peroxide formed and initiated popcorn polymerisation which burst the pipeline. 

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