Mehmet Tosun
Abant Izzet Baysal University
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Featured researches published by Mehmet Tosun.
Pediatrics International | 2014
Sevil Bilir Goksugur; Ali Evren Tufan; Murat Semiz; Cemalettin Gunes; Mervan Bekdas; Mehmet Tosun; Fatih Demircioglu
Attention‐deficit–hyperactivity disorder (ADHD), one of the most common psychiatric disorders of childhood, has an early onset, affecting 2–18% of children worldwide. The etiopathogenesis of ADHD is obscure. In recent studies, a low level of vitamin D has been found in association with many disorders as well as in neuropsychiatric diseases. The aim of this study was therefore to investigate serum vitamin D level in pediatric ADHD patients.
Kidney & Blood Pressure Research | 2012
Aytekin Alcelik; Mehmet Tosun; Mehmet Fatih Özlü; Mustafa Eroglu; Gulali Aktas; Eray Kemahli; Haluk Savli; Mehmet Yazici
Introduction: Cardiovascular disease is the leading cause of morbidity and mortality in hemodialysis patients. Therefore, evaluation and prevention of cardiovascular diseases in end-stage renal disease (ESRD) patients are very important. The plasma level of omentin was found to be associated with different conditions such as insulin resistance. It is one of the novel adipokines synthesized mainly in the visceral adipose tissue. In this study, we aimed to investigate the level of omentin in patients with ESRD receiving hemodialysis. Methods: The study population consisted of 59 adult chronic hemodialysis patients (30 women and 29 men) and age-matched control subjects were selected from apparently healthy subjects (28 participants; 14 women and 14 men). Blood samples were obtained before the dialysis session. Omentin concentrations were determined by using enzyme-linked immunosorbent assay. Results: Plasma levels of omentin were found to be markedly higher in ESRD patients (606.6 ± 313.0 ng/ml) than in the control group (357.5 ± 147.4 ng/ml; p < 0.0001). Also, serum omentin levels were found to be correlated with creatinine (r = 0.333, p = 0.002). Conclusions: Omentin levels were found to be elevated in patients with ESRD receiving hemodialysis. To the best of our knowledge, this is the first clinical study that demonstrated the association between omentin and ESRD.
International Journal of Rheumatic Diseases | 2010
Erhan Capkin; Hasim Cakirbay; Murat Karkucak; Murat Topbas; Münevver Serdaroğlu; Mustafa Güler; Mehmet Tosun
Aim: The aim of this study was to estimate the prevalence of rheumatoid arthritis (RA) in the eastern Black Sea region of Turkey.
British Journal of Ophthalmology | 2012
Mehmet Tosun; Mesut Erdurmus; Guler Bugdayci; Serdal Çelebi; Aytekin Alcelik
Objective Asymmetric dimethyl arginine (ADMA) is the major endogenous inhibitor of nitric oxide synthase. ADMA is related to endothelial dysfunction and is an independent cardiovascular risk factor. This study aimed to evaluate the concentration of ADMA in aqueous humour and serum samples of patients with pseudoexfoliation (PEX) syndrome. Materials and Methods 21 cataract patients with PEX syndrome (PEX group) and 18 cataract patients without PEX syndrome (control group) were enrolled in the study. ADMA was measured in the aqueous humour and serum of the PEX and control groups. ELISA was used to determine the ADMA concentration. Results Mean aqueous humour ADMA concentration in the PEX group was 0.39±0.07 μmol/l and in the control group was 0.34±0.06 μmol/l. Mean serum ADMA concentration in the PEX group was 0.56±0.21 μmol/l and in the control group was 0.44±0.12 μmol/l. ADMA concentration of aqueous humour in the PEX group was significantly higher than the control group (p=0.026). Similarly, ADMA concentration of serum in the PEX group was significantly higher than the control group (p=0.039). Conclusions The findings of the present study could suggest that ADMA might play a role in the aetiopathogenesis of PEX syndrome. Higher aqueous and serum levels of ADMA might be potential evidence of endothelial dysfunction in PEX syndrome.
Cardiology Journal | 2012
Serkan Öztürk; Oguz Dikbas; Mehmet Ozyasar; Selim Ayhan; Fatih Ozlu; Davut Baltaci; Alim Erdem; Aytekin Alcelik; Mehmet Tosun; Mehmet Yazici
Background: The aim of this study was to investigate left atrial (LA) mechanical functions, atrial electromechanical delay and P wave dispersion in hypothyroid patients. Methods: Thirty-four patients with overt hypothyroid and thirty controls were included. A diagnosis of overt hypothyroid was reached with increased serum TSH and decreased free T4 (fT4) levels. LA volumes were measured using the biplane area length method and LA active and passive emptying volumes and fraction were calculated. Intra- and interatrial electromechanical delay (EMD) were measured by tissue Doppler imaging (TDI). P wave dispersion was calculated by 12 lead electrocardiograms. Results: LA diameter were significantly higher in patients with overt hypothyroid (p = 0.021). LA passive emptying volume and LA passive emptying fraction were significantly decreased with hypothyroid patients (p = 0.002 and p Conclusions: This study showed that impaired LA mechanical and electromechanical function in hypothyroid patients. TSH and T4 were independent determinant of interatrial EMD and LA active emptying fraction.
The Anatolian journal of cardiology | 2012
Mehmet Fatih Özlü; Serkan Öztürk; Suzi Selim Ayhan; Mehmet Tosun; Aytekin Alcelik; Alim Erdem; Mehmet Yazici
OBJECTIVE Platelets play an important role in both initiation and propagation of acute coronary syndromes. We sought to evaluate the predictive value of mean platelet volume (MPV) in young patients with non-ST-segment elevation acute coronary syndromes (NSTE-ACS). METHODS This is a retrospective observational study; evaluating the MPV values of 79 NSTE-ACS patients aged under 45 years and 45 control subjects having normal coronary anatomy. NSTE-ACS group was composed of 41 non-ST elevation myocardial infarction (NSTEMI) and 38 unstable angina pectoris (USAP) patients. MPV was measured using an automated hematologic analyzer called Coulter counter. The predictive value of MPV was evaluated using logistic regression analysis and comparison of MPV between NSTE-ACS and control groups was performed by Mann-Whitney U test. RESULTS The MPV was found to be significantly higher in the NSTE-ACS compared with control group (8.49±1.22 versus 7.78±0.65 fL, p=0.001). In logistic regression analysis, MPV was found to be an independent predictor of NSTE-ACS (OR=3.1, 95% CI 1.2-8.2, p=0.022). The MPV values of NSTEMI group were not significantly different from USAP group (8.78±1.38 versus 8.17±0.95 fL, p=0.66). Similarly, the MPV values of the 3 groups (Control, USAP and NSTEMI) were found to be significantly different (7.78±0.65, 8.18±0.95, 8.78±1.38 fL respectively, p=0.001). CONCLUSION In conclusion, MPV was found to be elevated in NSTE-ACS patients compared with control subjects in young population. In addition, increased MPV was established to be an independent predictor of NSTE-ACS.
Cardiology Journal | 2012
Serkan Öztürk; Aytekin Alcelik; Mehmet Ozyasar; Oguz Dikbas; Selim Ayhan; Fatih Ozlu; Alim Erdem; Mehmet Tosun; Davut Baltaci; Mehmet Yazici
BACKGROUND The heart was very sensitive to fluctuating thyroid hormone levels. To assess intra-left ventricular (LV) systolic asynchrony in patients with subclinical thyroid dysfunction. METHODS Fifty patients with subclinical hypothyroidism and 40 controls were included. A diagnosis of subclinical hypothyroidism was reached with increased TSH and normal free T4. All subjects were evaluated by echocardiography. Evaluation of intra-LV systolic asynchrony was performed by tissue synchronization imaging (TSI), and four TSI parameters of systolic asynchrony were calculated. LV asynchrony was defined by these parameters. RESULTS All of the groups were similar in terms of demographic findings and conventional and Doppler echocardiograpic parameters except peak systolic velocity and early diastolic velocity. LV systolic asynchrony parameters of TSI including; standard deviation of Ts of the 12 LV segments (Ts-SD-12), maximal difference in Ts between any 2 of the 12 LV segments (Ts-12), standard deviation of TS of the 6 basal LV segments (Ts-SD-6), maximal difference in Ts between any of the 6 basal LV segments (Ts-6) were significantly lengthened in patients with subclinical hypothyroidism than controls (p <0.001, p < 0.001, p < 0.001 and p < 0.001, respectively). The prevalence of LV asynchrony was significantly higher in patients with subclinical hypothyroidism than control. CONCLUSIONS Patients with subclinical hypothyroidism present evidence of LV asynchrony by TSI. LV systolic asynchrony could be a warning sign of the early stage in cardiac systolic dysfunction in subclinical hypothyroid patients.
Experimental and Clinical Endocrinology & Diabetes | 2014
Gulali Aktas; Aytekin Alcelik; T. Ozlu; Mehmet Tosun; Buket Kin Tekce; Haluk Savli; Hikmet Tekce; Oguz Dikbas
AIMS Omentin is a new adipokine secreted mainly from visceral adipose tissue. Serum omentin is found to be reduced in patients with impaired glucose tolerance, type 2 diabetes mellitus, obesity and insulin resistant states. Despite the fact that pregnancy is also characterized with hyperinsulinemia, literature is lacking about data of omentin levels and its association with insulin resistance in pregnant women. We aimed to evaluate the association of omentin levels and insulin resistance in pregnant women and to compare these levels with those of non-pregnant, non-diabetic women. METHODS Uncomplicated pregnant women who admit to our outpatient clinics for routine follow-up were included in the study group. Non-pregnant women without diabetes mellitus were served as control group. Fasting glucose, insulin, omentin levels and HOMA IR were recorded. SPSS 15.0 for Windows was used for statistical analysis. RESULTS There were 36 pregnant women in the study group and 37 healthy, non-pregnant women in the control group. Serum omentin and fasting glucose levels were significantly decreased and fasting insulin was significantly increased in the study group compared to control group. CONCLUSION Omentin might be an indicator of insulin resistance in pregnant women. Larger prospective studies are needed to claim whether omentin can have a clinical use for diagnosis of gestational diabetes mellitus.
Acta Chirurgica Belgica | 2013
Arif Duran; Hulya Ozturk; Elçin Hakan Terzi; Mehmet Tosun; T. Ocak; A. Kühner
Abstract Objective : Ischemia-reperfusion (I-R) injury of the intestine is a significant problem because the initial damage caused by ischemia is exacerbated by reperfusion. In this study, we examined the protective effect of montelukast against I-R-induced intestinal tissue damage. Materials and methods : Eight-week-old male Sprague-Dawley rats were randomly divided into three treatment groups: a sham-operated group, a group receiving I-R, and a group receiving I-R plus montelukast (I-R/M). Tissue samples were evaluated and scored histologically. The blood levels of malondialdehyde (MDA), myeloperoxidase (MPO), glutathione (GSH), and cardiotrophin-1 (CT-1) were measured. Results : In the I-R group, the histological score and the levels of serum MDA and MPO were increased compared with those in the control group. In the I-R/M group, the histological score and serum MDA and MPO levels were significantly decreased compared with those in the I-R group. Additionally, compared with the IR group, the I-R/M group had increased serum GSH and CT-1 levels and a decreased intestinal injury score. Ileal sections from the I-R/M group showed minimal alterations, characterized by moderate lifting of the epithelial layer from the lamina propria, and few apoptotic enterocytes were observed compare with the number in the I-R group. Conclusion : The findings of the present study demonstrated that montelukast can protect I-R-induced intestinal damage in rats.
Cardiology Journal | 2015
Serkan Ordu; Bekir Serhat Yildiz; Yusuf Izzettin Alihanoglu; Aybars Ozsoy; Mehmet Tosun; Harun Evrengul; Havane Asuman Kaftan; Hakan Ozhan
BACKGROUND Heart rate (HR) reduction is associated with improved outcomes in patients with heart failure (HF) and biomarkers can be a valuable diagnostic tool in HF management. The primary aim of our study was to evaluate the short-term (6 months) effect of ivabradine on N-terminal pro B-type natriuretic peptide (NT-proBNP), CA-125, and cystatin-C values in systolic HF outpatients, and secondary aim was to determine the relationship between baseline HR and the NT-proBNP, CA-125, cystatin-C, and clinical status variation with ivabradine therapy. METHODS Ninety-eight patients (mean age: 65.81 ± 10.20 years; 33 men), left ventricular ejection fraction < 35% with Simpson method, New York Heart Association (NYHA) class II-III, sinus rhythm and resting HR > 70/min, optimally treated before the study were included. Among them, two matched groups were formed: the ivabradine group and the control group. Patients received ivabradine with an average (range of 10-15) mg/day during 6 months of follow-up. Blood samples for NT-proBNP, CA-125, and cystatin-C were taken at baseline and at the end of a 6-month follow-up in both groups. RESULTS There was a significant decrease in NYHA class in the ivabradine group (2.67 ± ± 0.47 vs. 1.85 ± 0.61, p < 0.001). When ivabradine and control groups were compared, a significant difference was also found in NHYA class 6 months later (p = 0.013). A significant decrease was found in HR in the ivabradine and control groups (84.10 ± 8.76 vs. 68.36 ± ± 8.32 bpm, p = 0.001; 84.51 ± 10 vs. 80.40 ± 8.3 bpm, p = 0.001). When both groups were compared, a significant difference was also found in HR after 6 months (p = 0.001). A significant decrease was found in cystatin-C (2.10 ± 0.73 vs. 1.50 ± 0.44 mg/L, p < 0.001), CA-125 (30.09 ± 21.08 vs. 13.22 ± 8.51 U/mL, p < 0.001), and NT-proBNP (1,353.02 ± 1,453.77 vs. 717.81 ± 834.76 pg/mL, p < 0.001) in the ivabradine group. When ivabradine and control groups were compared after 6 months, a significant decrease was found in all HF parameters (respectively; cystatin-C: p = 0.001, CA-125: p = 0.001, NT-proBNP: p = 0.001). Creatinine level was significantly decreased and glomerular filtration rate (GFR) was significantly increased in the ivabradine group (1.02 ± 0.26 vs. 0.86 ± 0.17, creatinine: p = 0.001; 79.26 ± 18.58 vs. 92.48 ± 19.88, GFR: p = 0.001). There was no significant correlation between NYHA classes (before and after ivabradine therapy) and biochemical markers, or HR. CONCLUSIONS In the outpatients with systolic HF, persistent resting HF > 70/min with optimal medical therapy, the NT-proBNP, CA-125, and cystatin-C reductions were obtained with ivabradine treatment. Measurement of NT-proBNP, CA-125, and cystatin-C may prove to be useful in biomarker panels evaluating ivabradine therapy response in HF patients.