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Öğe Cisplatin-induced acute renal failure is ameliorated by erdosteine in a dose-dependent manner(Wiley, 2004) Özyurt, H; Yildirim, Z; Kotuk, M; Yilmaz, HR; Yagmurca, M; Iraz, M; Sögüt, SThe aim of this study was to investigate the optimum dosage of erdosteine to ameliorate cisplatin-induced nephrotoxicity. Three different doses of erdosteine at 25, 50 and 75 mg kg(-1) were studied in rats. Intraperitoneal administration of 7 mg kg(-1) cisplatin led to acute renal failure, as indicated by kidney histology and increases in plasma creatinine and blood urea nitrogen (BUN) levels. At 5 days after cisplatin injection the BUN level was increased significantly from 15.1 +/- 4.3 to 126.7 +/- 152.6 mg dl(-1) and plasma creatinine levels increased from 0.37 +/- 0.005 to 1.68 +/- 1.9 mg dl(-1). When the rats were administered 50 and 75 mg kg(-1) erdosteine 24 h before cisplatin injection that was continued until sacrifice (total of 6 days), the BUN and creatinine levels remained similar to control levels and the grade of histology was similar. Erdosteine at doses of 50 and 75 mg kg(-1) ameliorates cisplatin-induced renal failure. The optimum dose of erdosteine may be 50 mg kg(-1) in this study. Copyright 2004 John Wiley Sons, Ltd.Öğe The effects of erdosteine on the activities of some metabolic enzymes during cisplatin-induced nephrotoxicity in rats(Academic Press Ltd- Elsevier Science Ltd, 2004) Yilmaz, HR; Iraz, M; Sogut, S; Ozyurt, H; Yildirim, Z; Akyol, O; Gergerlioglu, SCisplatin is one of the widely used chemothrapeutic agents. One of the major side effects of the drug is renal toxicity. The aims of the presented study was (1) to investigate the effect of cisplatin on some renal metabolic enzyme activities such as hexokinase (HK), glucose-6-phosphate dehydrogenase (G6PD), lactate dehydrogenase (LDH), and malate dehydrogenase (MDH) in an experimental model of acute renal failure and (2) to examine the protective role of erdosteine, an expectorant agent which has also antioxidant properties on cisplatin-induced nephrotoxicity and the enzyme activities mentioned above. Female Wistar albino rats were divided into three groups: sham operation group (n = 6). cisplatin group (n = 9), erdostein + cisplatin group (n = 8). All the chemicals used were applied intraperitoneally. Hexokinase, G6PD, LDH, and MDH activities were determined in the kidney supernatant at the end of the surgical procedures. Spectrophotometric methods were used to determine the activities of above-mentioned enzymes in the kidney tissue. Hexokinase and G6PD activities were found to be increased in cisplatin group compared to control group. G6PD activities were found to be decreased in erdosteine + cisplatin group compared to cisplatin group. There were minimal changes in LDH and MDH activities of the two study groups compared with the control group. The results obtained suggested that the glucose metabolizing metabolic pathways of renal tissue were partially affected from cisplatin toxicity and erdosteine have some protective effects on these enzyme activities. (C) 2004 Elsevier Ltd. All rights reserved.Öğe Factors affecting the adsorption of buchnericin LB, a bacteriocin produced by Lactocobacillus buchneri(Urban & Fischer Verlag, 2002) Yildirim, Z; Avsar, YK; Yildirim, MBuchnericin-LB adsorbs to gram-positive but not to gram-negative bacteria. The tested gram-positive bacteria were species of Lactobacillus, Pediococcus, Leuconostoc, Enterococcus, Lactococcus, Listeria, Bacillus, Staphylococcus; gram-negative bacteria belonged to the genera Salmonella, Escherichia, Yersinia and Pseudomonas. Buchnericin-LB adsorption depended on pH but not on time and temperature. Also some anions of salts and lipoteichoic acid reduced or inhibited its adsorption. Treatment of cells and cell walls of sensitive bacteria with detergents, organic solvents or enzymes did not affect subsequent binding of buchnericin-LB. Treatment with buchnericin-LB caused sensitive cells to lose high amounts of intracellular K+ ions and UV-absorbing materials and became more permeable to o-nitrophenol-beta-D-galactopyranoside. Buchnericin-LB (640-2560 AU/ml) decreased the colony forming units (99%) and absorbance values of Listeria monocytogenes and Bacillus cereus. These results indicate that the mode of action of buchnericin-LB is bactericidal and its lethal effect is very rapid.Öğe Inhibitory effect of caffeic acid phenethyl ester on bleomycine-induced lung fibrosis in rats(Elsevier, 2004) Özyurt, H; Sögüt, S; Yildirim, Z; Kart, L; Iraz, M; Armutçu, F; Temel, IBackground: Pulmonary fibrosis (PF) induced by anticancerogenic bleomycin (BLM) is one of the more common side effects encountered during cancer treatment. It has been suggested in the last decades that the main responsible agent in PF is reactive oxygen species which were generated also in normal physiological conditions in the human body. In this experimental study, we investigated the preventive or attenuating effects of caffeic acid phenethyl ester (CAPE) that has been demonstrated to have anti-inflammatory, cytocytatic, anti cancerogenic, antiprolipherative and antioxidant effects on BLM-induced PF. Methods: Thirty-six Sprague-Dawley rats were divided randomly into four groups as sham operation, BLM, BLM + vitamin E (vit E), and BLM + CAPE groups. BLM (7.5 mg/kg, single dose) was applied intratracheally, and CAPE and vit E intraperitoneally in the appropriate groups. At the end of the fibrosis processes, lung tissues were removed and the levels of tissues hydroxyproline (OH-proline), malondialdehyde (MDA) and NO as well as the activities of superoxide dismutase (SOD), catalase (CAT) and myeloperoxidase (MPO) were determined. Also, the weights of the rats were recorded at 7th and 14th days of the experiments. Results: BLM application to the rats resulted in a significant increase in the OH-proline level as compared to the controls. Administration of CAPE and vit E led to the remarkable reduction of total lung OH-proline levels compared to the rats treated with BLM alone (p < 0.0001). There were a decreases in antioxidant enzyme (SOD and CAT) activities while an increase in MPO activity in BLM group was found vs. the control group (p < 0.0001). CAPE had a regulator effect on these parameters: the increase in CAT and SOD activities and the decrease in MPO activity were seen after CAPE application. NO, MDA and OH-proline levels were increased in BLM group vs. the control group. CAPE was more effective in decreasing the tissue levels of NO, MDA and OH-proline than vit E. MPO activity, as a good marker of neutrophil sequestration to the tissues, in the BLM group was decreased by CAPE approximately to the control group. Conclusion: We suggest that CAPE is more effective on the prevention of BLM-induced fibrosis via antioxidant and free radical scavenger properties than vit E at the doses used in the present study. CAPE has some attenuating effects on BLM-induced PF affecting both oxidant and antioxidant systems as well as neutrophils sequestration. (C) 2003 Elsevier B.V. All rights reserved.Öğe Use of retentate powder in the production of white-brined cheese by the direct recombination system. 1. Effect of different protein levels an the ripening behaviour(A V A Agrarverlag, 2001) Avsar, YK; Yildirim, M; Yildirim, ZIn this study, a white-brined cheese with different protein content (similar to 12.5, 14.0, 15.5 or 17.0%) but the same total solids (similar to 40%) was produced by the direct recombination system, using retentate powder, skim-milk powder and anhydrous milk fat. For cheese-making, cheese milk composition was adjusted to the equivalent to that of cheese. During a 30 day of ripening period, changes in the gross composition, nitrogen fractions and ripening indices of cheese samples were monitored at 10 day intervals. It was found that there was no significant effect of the protein level on the final composition of the experimental cheese although a fluctuation in the composition of the cheese samples was observed during the early days of ripening. Results also showed that it was possible to produce a white-brined cheese with a defined composition. Owing to the limited syneresis and the use of milk powders, considerable amounts of whey protein nitrogen (0.17 to 0.26%) and lactose (1.6 to 5.9%) were retained in the experimental cheese at the end of the ripening. For this reason, whey proteins should be excluded in the calculation of ripening degree. In addition. increasing the protein content appeared to hinder the proteolysis.Öğe Use of retentate powder in the production of white-brined cheese by the direct recombination system. 2. Effect of different protein levels on the rheological properties(Volkswirtschaftlicher Verlag, 2002) Avsar, YK; Yildirim, Z; Yildirim, MIn this study, the effect of protein contents on the textural properties of white-brined cheese produced by the direct recombination system (DRS) using retentate powder was investigated. The total solids and fat content of cheese was kept same, but the samples differed in protein content (12.5, 14.0, 15.5 and 17.0%, respectively). A compression test was applied and elasticity modulus, yield stress and yield strain were obtained from force-time curves. Samples were analysed for a period of 30 d at 10 d intervals. Increasing the protein content up to a certain level (14.0%) increased the elasticity modulus and yield stress. However, beyond that level (i.e. 15.5 and 17.0%) no effect of additional protein was observed suggesting that after a critical level is reached the additional protein increased the viscous component of the cheese rather than the elastic one. Unlike the other parameters, the protein levels did not affect the yield strain since this parameter is closely related to pH and proteolysis. Yield stress and yield strain values decreased, and the cheese samples became considerably shorter during maturation as an indication of breakdown of the bonds holding the structure.
