Tevfik Gulyasar
Trakya University
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Featured researches published by Tevfik Gulyasar.
Biological Trace Element Research | 2007
Ali Riza Kiziler; Birsen Aydemir; Ilhan Onaran; Bulent Alici; Hamdi Özkara; Tevfik Gulyasar; Mehmet Can Akyolcu
We measured the levels of malondialdehyde (MDA), protein carbonyls, glutathione S-transferase (GST) and reducte glutathione (GSH) in seminal plasma and spermatozoa from 95 subjects including 50 infertile patients to evaluate the association between oxidative stress and damage and the components of the anti-oxidant defenses in seminal plasma and spermatozoa of infertile subjects and concentrations of cadmium (Cd) and lead (Pb) in the blood and seminal plasma because of tobacco smoke exposure. The reactive oxygen species (ROS) in spermatozoa were also evaluated by luminol (5-amino-2,3-dihydro-1,4-phthalazinedione)-enhanced chemiluminescence assay. The sperm count, motility, and morphology in the smokers infertile group were found to be lower than those in the fertile male group and nonsmokers infertile group (p < 0.001). Concentrations of Cd, Pb, MDA, protein carbonyls, and ROS levels in the smokers infertile group were significantly higher than those in the fertile male and nonsmokers infertile male groups (p < 0.001). However, GSH levels and GST activities were decreased in the smokers infertile male group than those in the fertile male and nonsmokers infertile male groups (p < 0.001). The results indicate that smoking could affect semen quality and oxidative lipid and protein damage in human spermatozoa. From Pearson correlation analysis, positive correlations were demonstrated between the seminal plasma Cd and seminal plasma protein carbonyls and between seminal plasma Pb and spermatozoa ROS levels in smokers of the subfertile group, while there was a significant positive correlation between blood Cd and ROS levels in smokers of the fertile group. There was also a significant negative correlation of the Cd level of the blood and GSH levels of the sperm and seminal plasma. These findings suggest that cigarette smoking enhances the levels of Cd and Pb in seminal plasma and blood and the extent of oxidative damage associated with a decrease in components of the anti-oxidant defenses in the sperm of infertile males.
Biological Trace Element Research | 2015
Ali Riza Kiziler; Birsen Aydemir; Savas Guzel; Cenk Murat Yazici; Tevfik Gulyasar; Ercan Malkoc; Ayse Acar
Increased oxidative damage has been suggested to play an important role in the spermatogenesis and sperm function changes in patients with varicocele. However, changes in levels of nitric oxide (NO), asymmetric dimethylarginine (ADMA), malondialdehyde (MDA), iron (Fe), zinc (Zn) and copper (Cu) in blood and seminal plasma, and semen quality, are unknown. The aim of this study was to investigate the NO, ADMA, Fe, Cu, Zn and MDA levels from seminal plasma and peripheral and spermatic vein blood samples of patients with varicocele before and after varicocelectomy. In this before and after comparative study, 29 consecutive patients attending a training hospital in Tekirdag, Turkey, were recruited. MDA and NO levels were determined by spectrophotometric methods. The levels of ADMA were determined by enzyme-linked immunosorbent assay method. Trace element level was determined by atomic absorption spectrophotometric method. The levels of MDA in the seminal plasma and peripheral and spermatic vein samples were observed to decrease significantly in the comparison of before and after phases of the study group (p = 0.022, p = 0.001 and p = 0.034, respectively). Also, the levels of NO in the seminal plasma and spermatic vein samples decreased significantly in the comparison of before and after phases of the study group (p = 0.025 and p = 0.001, respectively), while the levels of ADMA in seminal plasma and spermatic vein samples increased significantly in the comparison of before and after phases of the study group (p = 0.003 and p = 0.001, respectively). There were no significant differences in the levels of trace elements and sperm count (p > 0.05). Oxidative stress is significantly higher in the spermatic vein and seminal plasma samples of patients with varicocele before varicocelectomy. In conclusion, these events may be evaluated accordingly for the potentially beneficial treatment methods.
Nigerian Journal of Clinical Practice | 2018
Savas Guzel; Fatma Behice Serinkan Cinemre; Eda Celik Guzel; Volkan Küçükyalçin; Ali Riza Kiziler; C Cavusoglu; Tevfik Gulyasar; Hakan Cinemre; Birsen Aydemir
Background and Objectives: Hypertension (HT) is one of the risk factors associated with atherosclerosis. Midkine (MK) plays a role as a growth factor in various biologic and pathologic events. In some reports, MK expression has been shown to be linked with vascular smooth muscle proliferation and neo-angiogenesis in atherosclerotic vessels. The aim was to research relationship of MK serum levels with some atherosclerotic risk factors in hypertensive patients. Methodology: This study examined 60 patients with essential HT and 30 healthy controls. Serum biochemistry, including lipid profile, MK, Vitamin B12, C-reactive protein, zinc and copper levels were obtained. Results: MK levels of the HT patients were significantly higher than the control group (24.8 ± 6.8 ng/mL vs. 18.39 ± 5.6 ng/mL, respectively, P < 0.01). Lipid profile parameters such as total cholesterol, triglyceride, low-density lipoprotein (LDL) were also significantly higher in HT patients (P < 0.021, P < 0.01, and P < 0.01, respectively). Zinc levels were 179.13 ± 34.06 μg/dL and 172.55 ± 45.47μg/dL in the HT and control group, respectively. Serum MK levels were positively correlated with diastolic (r = 0.288, P < 0.05) and systolic blood pressures (r = 0.390, P < 0.002), and also with serum total cholesterol (r = 0.406, P < 0.002) and LDL cholesterol (r = 0.318, P < 0.015) levels. Furthermore MK was also negatively correlated with zinc and Vitamin B12levels (r = −0.298, P < 0.023, r = −0.334, P < 0.027, respectively). Conclusion: This study has demonstrated an important association between increased serum MK levels and risk factors of atherosclerosis such as HT, increased total and LDL cholesterol.
Biotechnology & Biotechnological Equipment | 2018
Arzu Ay; Nevra Alkanli; Tammam Sipahi; Tevfik Gulyasar; Sedat Ustundag; Sibel Guldiken; Necdet Sut
ABSTRACT The aim of this study was to investigate the relationship between MTHFR, IRS and CALCA gene polymorphisms and development of diabetic nephropathy (DN) in patients with type 2 diabetes mellitus (DM). Our study included 93 patients with type 2 DM diagnosed as having nephropathy and 95 controls diagnosed with type 2 DM without development of DN. Polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) were used to determine the genotype distributions of MTHFR, IRS and CALCA gene polymorphisms. The results showed no statistically significant difference between DN patients and type 2 DM controls in terms of genotype distributions of MTHFR (C677T, A1298C), IRS (IRS-1 Gly972Arg, IRS-2 Gly1057Asp) and CALCA T692C gene polymorphisms (p > 0.05). However, in terms of allele frequencies for the MTHFR A1298C gene, the frequency of the C allele was significantly higher in the DN patients compared to the controls (p < 0.05). In the IRS-2 Gly1057Asp gene polymorphism, the G allele frequency was significantly higher in the DN patients than in the type 2 DM controls (p < 0.05). In the DN group, the individuals with one or less mutant alleles were significantly more than in the control group in terms of the IRS-2 Gly1057Asp gene polymorphism (p < 0.05). The C allele frequency for the MTHFR A1298C gene polymorphism and the G allele frequency for the IRS-2 Gly1057Asp gene polymorphism were indicated to be potential a genetic risk factor for the development of DN in patients with type 2 DM who developed DN.
Biological Trace Element Research | 2008
Ali Riza Kiziler; Birsen Aydemir; Tevfik Gulyasar; Ethem Unal; Pembegul Gunes
Biological Trace Element Research | 2011
Osman Celbis; Yunus Karakoc; Bora Ozdemir; Tevfik Gulyasar; Suat Cakina
Biological Trace Element Research | 2011
Yunus Karakoc; Mehmet Seyfi Buruk; Burak Aktan; Ramazan Kirvar; Songul Erdogan; Mehmet Akif Sahbaz; Sevket Aksoy; Tevfik Gulyasar
Indian Journal of Biochemistry & Biophysics | 2013
Suat Cakina; Tevfik Gulyasar; Alaattin Özen; Tammam Sipahi; Zafer Kocak; Seralp Sener
Trace Elements and Electrolytes | 2018
Fatma Behice Serinkan Cinemre; Hakan Cinemre; Elif Erdoğan; Nilgün Dilaveroğlu; Abdullah Tuten; Baris Kaya; Nevin Yilmaz; Tevfik Gulyasar; Mustafa Yıldız; Nurten Bahtiyar; Ali Riza Kiziler; Birsen Aydemir
Trace Elements and Electrolytes | 2018
F. Behice Cinemre; Hakan Cinemre; Ayşe Yücel; Sevgin Değirmencioğlu; Abdullah Tuten; M. Aytaç Yüksel; Nevin Yılmaz; Tevfik Gulyasar; Mustafa Yıldız; Nurten Bahtiyar; Ali Rıza Kızıler; Birsen Aydemir