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    Adenosine deaminase and 5 '-nucleotidase activities in saliva from patients with oral and laryngeal cancer
    (Wiley, 2005) Saracoğlu, Umut; Güven, Orhan; Durak, İlker
    Objective: The aim of this study was to evaluate saliva's activities of adenosine deaminase (ADA) and 5'-nucleotidase (5'-NT) enzymes and their utility as diagnostic and therapeutic markers in oral and laryngeal cancer. Materials and Methods: Pre- and post-operative saliva's activities of ADA and 5'-NT enzymes were measured in patients with squamous cell oral (n=10) and laryngeal cancer (n=17) and compared with control saliva samples (n=19). Results: The ADA was found to be lower in saliva of the patients with oral cancer compared with the laryngeal cancer and controls. However, no significant differences were found between pre- and post-operative values for both enzymes in the patient groups. We also could not find statistically significant differences between saliva's activities of 5'-NT in patients and control subjects. Conclusions: Low activity of ADA observed in saliva of the patients with oral cancer has been suggested as a compensatory mechanism against rapid purine and DNA metabolism in cancer cells. The current study does not support the hypothesis that saliva's activities of these enzymes may be used as additional diagnostic and prognostic cancer markers.
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    Peroxidation in muscle and liver tissues from fish in a contaminated river due to a petroleum refinery industry
    (Academic Press Inc Elsevier Science, 2005) Avcı, Aslıhan; Kaçmaz, Murat; Durak, İlker
    In this study, we aimed to investigate the possible effects of the wastewater water contamination of a petroleum industry on the oxidant/antioxidant status of muscle and liver tissues from fish in the Kizilirmak River, Kirikkale, Turkey. The antioxidant/oxidant parameters were analyzed in the muscle and liver tissues from fish in 10km of the river above and below the industry. Malondialdehyde (MDA) and susceptibility to oxidation (SO) values were measured in the liver and muscle tissues as indexes of oxidation, and antioxidant potential (AOP), superoxide dismutase (SOD), glutathion peroxidase (GSH-Px), and catalase(CAT) activities were measured as indexes of antioxidant status. There was significant oxidation in the muscle tissue of the fish obtained in the river downstream of the industry compared to those obtained upstream of the industry. Although there were no meaningful differences between the SOD and GSH-Px activities, the AOP value and CAT activities were found to be reduced in the muscle tissues from the fish obtained downstream. In the liver tissues, the SOD and GSH-Px activities were found to be increased in the fish obtained downstream but no differences were observed in the MDA, SO, AOP, and CAT values. Our results suggest that some contaminants from the petrochemical industry cause oxidation in fish muscle tissues by impairing the antioxidant system. However, because no peroxidation was observed in the liver tissue from the downstream fish, it is possible that liver tissues have a stronger antioxidant capacity than muscle. (C) 2003 Published by Elsevier Inc.