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    Comparison of Open and Retroperitonoscopic Donor Nephrectomy in Terms of Lipid and Protein Peroxidation Responses
    (ELSEVIER SCIENCE INC, 2013) Dinckan, A.; Dinc, B.; Turkyilmaz, S.; Tekin, A.; Kocak, H.; Akbas, H.; Mesci, A.
    Background. This study was designed to compare donors who underwent open (ODN) versus retroperitonoscopic nephrectomy (RDN) in terms of intra-operative oxidative stress and recipients graft function in the early postoperative period. Methods. Among 40 patients who underwent donor nephrectomy, 23 were operated via an open method and 17 via retroperitonoscopic method. To analyze oxidative stress, we measured plasma levels of malondialdehyde (MDA), protein carbonyl, and protein sulfhydryl moieties in donor venous blood before induction of anesthesia and postoperatively at 0, 6, and 24 hours. The influence of oxidative stress on graft function was evaluated by means of the postoperative 5th day recipient creatinine and estimated glomerular filtration rate (eGFR) Modification of Diet in Renal Disease Formula (MDRD) to evaluate delayed graft function (DGF) status. Results. ODN patients showed significantly higher 24-hour mean levels of MDA, (6,139 +/- 1,854 vs 4,813 +/- 1,771 nmol/L; P =.01), protein carbonyl (366 +/- 64 vs 311 +/- 62 innol/L; P =.01) and protein sulfhydryl (468 +/- 110 vs 386 +/- 75 umol/L; P =.01) moieties compared with those RDN patients. However, ODN and RDN recipients were similar in terms of 5th day mean creatinine and eGFR (1.1 +/- 0.3 vs 1.4 +/- 0.8 mg/dL and 69.15 +/- 12.24 vs 56.31 +/- 25.2, respectively) and DGF status (4.4% [1/23] vs 5.9% [1/17], respectively). Conclusions. Although ODN donors were more prone to intra-operative oxidative stress than RDN donors, based on significantly higher levels of oxidative stress markers, this difference seems to not significantly influence recipients early graft function.
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    In vitro vasoactive effects of dexmedetomidine on isolated human umbilical arteries
    (COMENIUS UNIV, 2019) Arun, O.; Taylan, S. B.; Duman, I; Oc, B.; Yilmaz, S. A.; Tekin, A.; Celik, C.; Bariskaner H.; Celik J. B.
    OBJECTIVE: We aimed to investigate the vasoactive effects of dexmedetomidine on isolated human umbilical arteries and possible mechanisms involved. METHODS: Human umbilical artery strips were suspended in Krebs-Henseleit solution and dose-response curves were obtained for cumulative dexmedetomidine before and after incubation with different agents; propranolol, atropine, yohimbine, prazosin, indomethacin, verapamil. Effects of calcium on cumulative dexmedetomidine-induced contractions were also studied. RESULTS: Cumulative dexmedetomidine resulted in dose dependent contraction responses. Incubation with propranolol (Emax: 93.3 +/- 3.26 %), atropine (Emax: 92.0 +/- 6.54 %), or indomethacin (Emax: 94.25 +/- 2.62 %), did not attenuate dexmedetomidine-elicited contractions (p > 0.05). There were significant decreases in the contraction responses of cumulative dexmedetomidine with yohimbine (Emax: 12.1 +/- 11.9 %), prazosin (Emax: 28.8 +/- 4.6 %) and verapamil (Emax: 11.2 +/- 13.6 %) (p < 0.05). In Ca+2 free medium contraction responses to cumulative dexmedetomidine was insignificant (Emax: 5.20 +/- 3.42 %). Addition of cumulative calcium to the Ca+2 free medium resulted in concentration dependent increase in contractions (Emax: 64.83 +/- 37.7 %) (p < 0.05). CONCLUSION: Dexmedetomidine induces vasoconstriction in endothelial-free umbilical arteries via both, alpha(1)- and alpha(2)-adrenergic receptors and also extracellular Ca+2 concentrations play a major role. beta-adrenergic receptors, muscarinic cholinergic receptors, and inhibition of cyclooxygenase enzyme are not involved in this vasoconstriction (Fig. 3, Ref. 36). Text in PDF www.elis.sk.