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Publications (5)

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    [Show abstract] [Hide abstract] ABSTRACT: Although most general anaesthesia procedures are performed without any complications, volatile agents may have adverse effects on various living systems. This study aimed to compare the effects of desflurane and enflurane on liver function. 40 patients, who were in the ASA I-III risk groups and were planned to undergo head and neck surgery of at least three hours' duration, were randomly divided into two groups: the desflurane (Group D) and enflurane groups (Group E). Venous blood samples (5 ml) of the patients were obtained before anaesthesia induction, in the postoperative first hour and on the first and seventh days. The samples were centrifuged and then stored at -80 degrees Celsius until the determination of glutathione S-transferase (GST) levels. For maintenance of anaesthesia in Group D, desflurane (6 percent) was used, while in Group E, enflurane (1.2 percent) was used. GST levels were significantly higher in Group E in the postoperative first hour (p-value is 0.002), and on the first day (p-value is 0.025) and seventh day (p-value is 0.035), although there were no differences preoperatively (p-value is more than 0.05). When postoperative levels were compared with preoperative levels, the postoperative GST levels of Group E were significantly higher (first hour [p-value is 0.008], first day [p-value is 0.010], seventh day [p-value is 0.038]). Subclinical hepatic injury after anaesthesia continues to be an issue of interest, particularly with the development of new, more sensitive methods of measuring GST levels. The increase in GST concentration after anaesthesia is thought to be a result of reduced hepatic blood flow. This study has shown that desflurane has fewer effects than enflurane on liver function tests in lengthy operations of up to 330 minutes.
    Full-text available · Article · Feb 2009 · Singapore medical journal
  • [Show abstract] [Hide abstract] ABSTRACT: Methotrexate (MTX) is a folate antagonist used in treatment of several chronic inflammatory and neoplastic conditions. In this study, new MTX-like compounds that may-be potential anticancer agents were synthesized and their structures were determined by IR, UV, GC-MS, 1H NMR, and 13C NMR spectra. Also, in this study, a series structurally related to MTX or folate analogous compounds were evaluated whether they have inhibitory properties on the dihydrofolate reductase activity (DHFR).
    Article · Dec 2007 · Monatshefte fuer Chemie/Chemical Monthly
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    G Guz · E Oz · N Lortlar · [...] · C Karasu
    [Show abstract] [Hide abstract] ABSTRACT: Ischemia-reperfusion (I/R) injury is one of the most common causes of renal dysfunction. Taurine is an endogenous antioxidant and a membrane-stabilizing, intracellular, free beta-amino acid. It has been demonstrated to have protective effects against I/R injuries to tissues other than kidney. The aim of this study was to determine whether taurine has a beneficial role in renal I/R injury. Forty Wistar-Albino rats were allocated into four groups as follows: sham, taurine, I/R, and I/R+taurine. Taurine 7.5 mg/kg was given intra-peritoneally to rats in the groups taurine and I/R+taurine. Renal I/R was achieved by occluding the renal arteries bilaterally for 40 min, followed by 6 h of reperfusion. Immediately thereafter, blood was drawn and tissue samples were harvested to measure 1) serum levels of BUN and creatinine; 2) serum and/or tissue levels of malondialdehyde (MDA), glutathione (GSH), glucose 6-phosphate dehydrogenase (G-6PD), 6-phosphogluconate dehydrogenase (6-PGD) and glutathione reductase (GSH-red); 3) renal morphology; and 4) immunohistochemical staining for P-selectin. Taurine administration reduced I/R-induced increases in serum BUN and creatinine, and serum and tissue MDA levels (p<0.05). Additionally, taurine lessened the reductions in serum and tissue glutathione levels secondary to I/R (p<0.05). Taurine also attenuated histopathologic evidence of renal injury, and reduced I/R-induced P-selectin immunoreactivity (p<0.05). Overall, then, taurine administration appears to reduce the injurious effects of I/R on kidney.
    Full-text available · Article · Apr 2007 · Amino Acids
  • [Show abstract] [Hide abstract] ABSTRACT: To investigate the possible effects of repeated sevoflurane and desflurane anesthesia on hepatocellular system by evaluating the free radical metabolism, hepatocellular enzymes and histopatholgical changes in rats. Four groups of animals were studied. Sevoflurane 2% (v/v) and desflurane 6% (v/v) in air/O2 were administered to animals in group II (n=9) and III (n=9) respectively. 100% (v/v) O(2) was administered in group IV (n=9). Administration was done for 60 minutes over 3 days. Nine animals were allocated to control group (group I), superoxide dismutase (SOD), catalase (CAT), glutathion peroxidase (GSH-Px), glutathione-s-transferase (GST) and thiobarbituric acid reactive substances (TBARS) were studied. Also electron microscopy was performed. Catalase, SOD, GSH-Px, GST activities and TBARS levels were significantly higher in groups II and III than in group I (p<0.05). All parameters were significantly higher in groups II versus group IV (p<0.05). On the other hand, SOD, GSH-Px and GST activities were significantly elevated in group III than IV, but CAT activity and TBARS levels were not significantly. Catalase, SOD, GSH-Px, GST but not TBARS levels were significantly higher in groups II and III than in group IV (p<0.05). TBARS levels were higher in group III than in group IV, but this elevation was not statistically significant. CAT, SOD and GSH-Px activities were significantly higher in groups II than in group III (p<0.05). Although electron microscopy findings were similar for group II and III, we can conclude that sevoflurane might cause more cellular damage than desflurane by causing higher activation of free radical metabolising enzymes.
    Article · Jan 2007 · Molecular and Cellular Biochemistry
  • [Show abstract] [Hide abstract] ABSTRACT: Miscarriage (early pregnancy failure) is a pregnancy-related disease, the pathophysiology of which is still not completely understood. Lipid peroxidation and alterations in antioxidant enzyme activities may be of importance in the pathogenesis of this disorder. This study was planned to investigate the possible relation between free radical scavenging enzyme activities and lipid peroxidation levels in placenta tissues with miscarriage. Placental tissue samples were obtained from 21 patients who had miscarried and 25 normal pregnant women undergoing elective abortion as a control group. Total superoxide dismutase (T-SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) enzyme activities and levels of thiobarbituric acid reactive substances (TBARS), antioxidant potential (AOP), and nonenzymatic superoxide radical scavenger activity (NSSA) were measured in the placental tissues. GSH-Px, CAT activities, and TBARS levels were found to be significantly increased, while T-SOD and NSSA values decreased in patients with early pregnancy failure when compared with women undergoing elective abortion (control group). However, there were no significant differences in AOP levels between the groups. Our results reflect oxidative stress in placenta tissues of early pregnancy failure, as the oxidative processes seem to be counteracted by the physiologic activation of antioxidant enzymes such as CAT and GSH-Px. Moreover, a compensatory mechanism might be developed against possible oxidative damage in patients with miscarriage.
    Article · Aug 2006 · Journal of the Society for Gynecologic Investigation