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Objective The purposes of this study is to evaluate the variations of total antioxidant status (TAS) and total oxidant status (TOS) levels in the treatment process of carbon monoxide poisoning (COP) and to learn more about the pathophysiology of COP. Methods Between 2011 and 2012, 113 patients were admitted to our emergency department with acute COP, and 50 healthy volunteers were used as a control group in this study. Serum, plasma and erythrocyte components were prepared for all the COP patients on admission. They were repeated at the 90th and 180th minute of treatment. The samples were taken once from the control group. Serum oxidant/antioxidant status levels and carboxyhaemoglobin (COHb) were measured. Ratio of TOS to TAS, known as oxidative stress index (OSI) was calculated. Results No correlation was observed among age, gender, COHb level, with the levels of TAS, TOS, and OSI. Admission levels of TOS and OSI in patients with COP were higher than that observed at 90th minutes (p0.05). Conclusions Our results show that serum TOS and OSI levels increase in COP patients. Oxidative stress should play a role in the pathophysiology of COP. (Hong Kong j.emerg.med. 2013;20:352-358)

Toluene, an organic solvent used widely in the industry, is highly lipophilic and accumulates in the cell membrane impeding transport through it. Its metabolites cause oxygen radical formation that react with unsaturated fatty acids and proteins in erythrocytes leading to lipid peroxidation and protein breakdown. In this study, we aimed to investigate the membrane stabilizing and the oxidative stress—inducing effects of toluene in human erythrocytes. Measurements of osmotic fragility, mean corpuscular volume (MCV), oxidative stress parameters and antioxidant enzyme activities were performed simultaneously both in individuals exposed to toluene professionally (in vivo) and human erythrocytes treated with toluene (in vitro). To measure osmotic fragility, erythrocytes were placed in NaCl solutions at various concentrations (0.1% [blank], 0.38%, 0.40%, 0.42%, 0.44%, 0.46%, 0.48% and 1% [stock]). Percentage of haemolysis in each solution was calculated with respect to the 100% haemolysis in the blank solution. The erythrocyte packs prepared at the day of the above-mentioned measurements were kept at —80°C until the time for determination of malonyldialdehyde and protein carbonyl levels, and catalase (CAT) and glutathione peroxidase activities as indicators of oxidative stress. Toluene increased oxidative stress parameters significantly both in vivo and in vitro; it also caused a significant decrease in the activities of antioxidant enzymes. Osmotic fragility was altered only in the case of in vitro exposure. In conclusion, toluene exposure resulted in increased lipid peroxidation and protein damage both in vivo and in vitro. Although, it is natural to expect increased osmotic fragility due to oxidative properties of toluene, its membrane-stabilizing effect overcame the oxidative properties leading to decreased osmotic fragility or preventing its deterioration in vitro and in vivo toluene exposures, respectively, in the present study.

This study investigated changing levels of serum oxidant/antioxidant with chemotherapy and their relation to treatment in 34 Hodgkin's lymphoma patients. The patient population consisted of 19 males and 15 females. Mean age was 30.41 ± 12.08 years. All patients received the adriamycin, bleomycin, vincristine and dexamethasone (ABVD) treatment protocol. Blood samples were taken before treatment, and on days 1 and 7 during treatment for measurement of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), malondialdehyde (MDA), nitric oxide (NO) and enzyme activities. After ABVD treatment, mean free radical levels were increased and antioxidant levels were significantly decreased in the serum. ABVD treatment results in an increase of free radical levels and a decrease of antioxidant levels in the serum of patients with Hodgkin's lymphoma.