Browsing by Author "Gursoy, Tulay"

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Alterations in Oxidative Stress Markers in Laryngeal Carcinoma Patients
(Lippincott Williams & Wilkins, 2018) Bozan, Nazim; Demir, Halit; Gursoy, Tulay; Ozkan, Huseyin; Duzenli, Ufuk; Sankaya, Eren; Cankaya, Hakan
Background: Data describing how laryngeal cancer affects oxidative stress markers and antioxidants are limited. This study investigated serum antioxidant enzyme activities and oxidative stress markers before and after laryngectomies in patients with laryngeal cancer. Methods: A total of 29 patients with laryngeal cancer and 25 healthy control subjects were enrolled. Serum malondialdehyde (MDA) levels and superoxide dismutase (SOD), glutathione peroxidase (GSHPx), catalase (CAT), paraoxonase (PON), and arylesterase activities were measured spectrophotometrically. Blood samples were obtained from each patient just before surgery and 1 month after a laryngectomy. Results: The serum PON, arylesterase, CAT, SOD, and GSHPx activities were significantly decreased (all p < 0.001) and serum MDA levels were significantly increased (p < 0.001) in patients with laryngeal cancer, compared with control subjects. In laryngeal cancer patients, the serum GSHPx and arylesterase activity levels increased significantly following laryngectomies (both p < 0.001), whereas the MDA levels decreased significantly (p = 0.007). Conclusion: In patients with laryngeal cancer, the oxidant/antioxidant balance shifted toward oxidative stress. In addition, following laryngectomies, laryngeal cancer patients had increases in serum antioxidant enzyme activities and decreases in oxidative stress markers. Copyright (C) 2018, the Chinese Medical Association. Published by Elsevier Taiwan LLC.
Heavy Metal Exposure of Workers Working at Petroleum Products Filling Stations and Its Effects on Oxidative Stress
(Parlar Scientific Publications (p S P), 2020) Atasoy, Nurhayat; Komuroglu, Ahmet Ufuk; Yucel, Ufuk Mercan; Kul, Ali Riza; Gursoy, Tulay
Petroleum products increase oxidative stress and inflammation due to its particulate content. This study aims to determine the levels of heavy metals (zinc, lead, cadmium, chromium) and to measure level of reduced glutathione and enzyme activity of superoxide dismutase in serum and hair specimens of workers (n=50, research group) employed in petroleum products filling stations in Van province. The control group (n=25) was selected working in the office and compared with the research group. Heavy metal levels in hair and serum specimens were determined by using the inductively matched plasma optical emission spectrometry instrument and serum enzyme levels were determined by using spectrophotometric methods. Zinc, lead, cadmium and chromium metal levels were higher in the research group than healthy controls. In addition, reduced glutathione level and superoxide dismutase enzyme activity decreased due to metal exposure and oxidative stress occurred in the research group. Smoking contributed to the exposure of amount of the metals. In research group, positive correlations were found between metal exposures and life span/term of employment. In addition, with the increased life span and term of employment, metal exposure increased and antioxidant enzyme levels decreased. This study shows that workers employed in stations are exposed to heavy metal toxicity and cause oxidative stress.
Investigation of Levels of Oxidative Stress and Antioxidant Enzymes in Colon Cancers
(derman Medical Publ, 2017) Dusak, Ahmet; Atasoy, Nurhayat; Demir, Halit; Dogan, Erkan; Gursoy, Tulay; Sarikaya, Eren
Aim: Free radicals play a key role in the development of degenerative diseases, none the less, effects of harmful reactive species can be controlled by natural defense mechanisms in the body. In this study, we aimed to investigate enzyme activities of superoxide dismutase (SOD), glutathione (GSH) reductase, glutathione peroxidase (GSH-Px), and malondialdehyde (MDA) in blood serum samples of patients with colon cancer. Material and Method: This retrospective study included patients diagnosed with colon cancer (n=25) and age-and sex-matched healthy individuals as the control group (n=25). Serum levels of SOD, GSH, GSH-Px, and MDA were analyzed using the spectrophotometric method. Results: Enzyme levels of SOD, GSH, GSH-Px, and MDA were found to be statistically significantly (p< 0.05), compared to the control group. There was a significant increase in the MDA levels (p< 0.05), whereas the SOD, GSH, and GSH-Px levels decreased in the patients with colon cancer, compared to the control group (p< 0.05). MDA levels were significantly higher in the patients with colon cancer, while antioxidant enzymes including SOD, GSH, and GSH-Px activities were significantly lower in these patients, compared to the control group (p< 0.05). Discussion: Our study, for the first time, suggests a relationship between colon cancer, oxidative stress, and antioxidant parameters. This is also the first study to investigate the levels of oxidative stress levels and antioxidant enzymes such as SOD, GSH, and GSH-Px activities in the literature. Also, decreased GSH-Px activity may increase MDA production, suggesting that serum SOD, GSH, GSH-Px and MDA levels can affect the etiopathogenesis of colon cancer.
A Molecularly Imprinted Cotton Fabric for Rapid, Selective and Sensitive Determination of Carbendazim in Orange Juice
(Academic Press inc Elsevier Science, 2024) Zengin, Adem; Toptas, Yeliz; Bilici, Mustafa; Gursoy, Tulay
Carbendazim is a type of benzimidazole fungicide commonly used to protect agricultural crops. It has high chemical stability and a long degradation half-life, which increases the potential for environmental accumulation. Herein, carbendazim-imprinted cotton fabric (MIPCF) was fabricated for the selective and sensitive detection of carbendazim in orange juice samples using spectrofluorimetry. The imprinted cotton fabrics were characterized using a variety of surface characterization techniques, and the results revealed the grafting of a polymer layer onto the cotton fabric. Furthermore, the MIPCF had a high adsorption capacity of 96.9 mg/g and an imprinting factor of 4.36. Importantly, MIPCF demonstrated satisfactory regeneration capability, enduring up to ten regeneration cycles without significantly reducing its initial adsorption capacity. The proposed method had excellent linearity with a correlation coefficient of 0.999 and a limit of detection of 1.12 mu g/L for carbendazim in orange juice samples. The proposed method exhibited acceptable recovery ranges (99.2-100 %) accompanied by lower inter-day and intra-day precisions. It is inferred that the proposed method offers a promising alternative for quantifying fungicides compared to conventional spectroscopic or chromatographic techniques.