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Öğe Adiponectin and insulin resistance in obesity-related diseases(Sage Publications Ltd, 2008) Ebinc, H.; Ozkurt, Z. N.; Ebin, F. A.; Yilmaz, M.; Caglayan, O.The relationship between insulin resistance and serum adiponectin levels in 400 subjects with different obesity-related diseases was studied. Lean subjects with body mass index (BMI) < 25 kg/m(2) were placed in one group and the other five groups of overweight/obese subjects with BMI >= 25 kg/m(2) were grouped according to disease profile. The homeostasis model assessment insulin resistance (HOMA-IR) index and adiponectin levels were similar in the lean, metabolically normal (MNO) and hypertensive groups, but were different when the dyslipidaemic group was compared with the lean and MNO groups. The type 2 diabetic (DMO) and hypertensive, type 2 diabetic (DMHTO) groups were significantly different from other groups with respect to HOMA-IR index and adiponectin levels. Adiponectin levels were lower in the DMHTO than the DMO group. In multiple regression analysis, adiponectin levels correlated with group categorization independently of age, sex, BMI and HOMA-IR. Hypoadiponectinaemia may play a role in the development of complications of obesity.Öğe Antenna-type radiofrequency generator in nanoparticle-mediated hyperthermia(Royal Soc Chemistry, 2016) Nasseri, B.; Yilmaz, M.; Turk, M.; Kocum, I. C.; Piskin, E.Induction of hyperthermia using nanoparticles with specific magnetic, electrical, acoustic, optical or thermal properties is a potential alternative to conventional thermal ablation in cancer therapy. In this study, for the first time we employed an antenna-type radiofrequency (RF) generator as the energy source and as a proof of concept the effects of nanoparticles of varying structures and sizes, such as super-paramagnetic iron oxide nanoparticles (SPIONs), gold-coated superparamagnetic iron oxide nanoparticles (Au@SPIONs), spherical gold nanoparticles (AuNPs), and gold nanorods (AuNRs) on RF hyperthermia were examined to determine hyperthermia efficiency of the antenna-type RF generator. In preliminary experiments, RF was applied at varying powers to various nanoparticle solutions. In all cases, temperature rises due to exposure of RF radiation to nanoparticles were captured by using an infrared thermal camera. This procedure was applied to in vitro tests of fibroblast (L-929) and breast cancer (MCF-7) cell lines. Cell viability, apoptosis and necrosis were evaluated in both cell lines to comprehensively determine cell toxicity. Due to their particle size and chemical nature, SPIONs, in the case of highest RF power and nanoparticle concentration, resulted in the lowest cell viability and highest levels of apoptosis and necrosis.Öğe CA 72-4 levels in patients with type 2 diabetes mellitus(Wiley, 2010) Demirci, H.; Erdamar, H.; Karakoc, A.; Akturk, M.; Yilmaz, M.; Arslan, M.Objective: CA 72-4 is one of the blood group carbohydrate antigens which can be used as a tumour marker in ovarian, pancreatic and gastrointestinal carcinomas. It can also be elevated in various benign conditions including pancreatitis. Diabetes mellitus is a chronic disorder related with the pancreas. In this study, we investigated CA 72-4 levels in patients with type 2 diabetes and its relation to the metabolic status. Methods: Sixty-nine patients with type 2 diabetes mellitus (female/male = 40/29) and 60 healthy subjects (female/male = 35/25) participated in this study. The levels of serum CA 72-4 were measured and faecal occult blood tests (following 3 days of white diet were obtained for three consecutive days) were performed in all patients. Patients had a pathological finding for any of these two parameters were further investigated with upper gastrointestinal endoscopy, colonoscopy and computerised tomography. Results: The mean levels of CA 72-4 was 1.89 +/- 2.61 U/ml in the study group and 1.4 +/- 0.98 U/ml in the control group (p > 0.05). There was no association between CA 72-4 levels and age and sex of the patients, duration of diabetes, body mass index, biochemical indicators of metabolic control (the levels of HbA(1c), fasting and postprandial glucose, serum lipids), the presence of microvascular complications (retinopathy, nephropathy, neuropathy) or treatment modalities. Conclusions: Elevated levels of CA 72-4 in diabetic patients are not related to diabetes and it should be interpreted as evaluated in a non-diabetic patient.Öğe Calpain 10 gene single-nucleotide 44 polymorphism may have an influence on clinical and metabolic features in patients with polycystic ovary syndrome(Springer, 2009) Yilmaz, M.; Yurtcu, E.; Demirci, H.; Ergün, M. A.; Ersoy, R.; Karakoç, A.; Arslan, M.Aim: This study was designed in order to examine the relationship between Calpain 10 [single-nucleotide polymorphism (SNP) 19,43,44,63] gene polymorphisms and clinical and hormonal characteristics in women with polycystic ovary syndrome (PCOS). Materials and methods: One hundred and seven patients with PCOS and 114 healthy subjects were included in this study. Serum levels of sex steroids were measured for each individual. Insulin resistance (IR) was evaluated by the homeostasis model assessment (HOMA) and quantitative insulin-sensitivity check index (QUICKI) methods. Insulin and glucose responses to the oral glucose tolerance test (OGTT) were analyzed by calculating the areas under the curve for insulin (AUCI) and glucose by the trapezoidal methods. We used PCR and restriction fragment length polymorphism technique to examine Calpain 10 SNP 19, 43, 44, and 63 polymorphisms. Results: Allele distribution of Calpain 10 SNP 44 gene polymorphism was observed as significantly different between the groups. Calpain 10 SNP 44 TC genotype was found to be increased in PCOS subjects (69.15%) compared to the control subjects (50%). However, when compared to control subjects, patients with PCOS had similar Calpain 10 SNP 19, Calpain 10 SNP 43, and SNP 63 gene polymorphisms. When compared with normal Calpain 10 gene SNP 44 allele in PCOS subjects, subjects with PCOS having Calpain 10 gene SNP 44 allele polymorphism had higher free testosterone, androstenedione, DHEA-S, and fasting insulin levels. Also, PCOS women with Calpain 10 gene SNP 44 allele polymorphism had high Ferriman-Gallwey (F-G) score, acne, prevalence of menstrual disturbances, waist-hip ratio, HOMA-IR, AUCI levels and low QUICKI levels. Conclusion: The findings show that Calpain 10 gene SNP 44 allele polymorphism may have a role in PCOS pathogenesis. However, larger-scale studies are needed in this field.Öğe The effects of rosiglitazone on insulin resistance and oxidative stress in non-obese patients with polycystic ovary syndrome(Elsevier Science Bv, 2005) Bukan, N.; Yilmaz, M.; Ayvaz, G.; Karakoç, A.; Toruner, F.; Çakir, N.; Arslan, M.…Öğe Effects of sympatholytic therapy with moxonidine on serum adiponectin levels in hypertensive women(Sage Publications Ltd, 2008) Ebinc, H.; Ozkurt, Z. N.; Ebin, F. A.; Ucardag, D.; Caglayan, O.; Yilmaz, M.We examined whether moxonidine influences lipid profile, insulin resistance, adiponectin levels, renal function and microalbuminuria in women with essential hypertension in a study of SS non-diabetic hypertensive patients and 53 normotensive women. Hypertensive patients received moxonidine for 12 weeks. At baseline the hypertensive group had significantly higher mean blood pressure, low-density lipoprotein cholesterol, triglycerides, total cholesterol, fasting glucose, urinary albumin excretion and homeostasis model assessment of insulin resistance (HOMA-IR), together with significantly lower mean high-density lipoprotein cholesterol, creatinine clearance and serum adiponectin than the normotensive group. Moxonidine significantly decreased blood pressure, fasting glucose, triglycerides, total cholesterol, HOMA-IR and albumin excretion, but significantly increased serum adiponectin. The change in adiponectin level was negatively correlated with the change in HOMA-IR. Moxonidine treatment may improve unfavourable metabolic status related to insulin resistance by increasing adiponectin levels in patients with essential hypertension. Since it can improve adiponectin levels, it may be used in the antihypertensive treatment of patients at high risk of diabetes and cardiovascular disease.Öğe Helicobacter pylori seropositivity and atherosclerosis risk factors(Karger, 2004) Köksal, A.; Ekmekci, Y.; Karadeniz, Y.; Köklü, S.; Apan, T.; Yilmaz, M.; Yildiz, A.Certain viral and bacterial infections may contribute to the initiation and progression of atherosclerosis. The aim of this study is to determine whether Helicobacter pylori ( HP) seropositivity contributes to conventional atherosclerosis risk factors in the development of an early sign of atherosclerosis: intima-media thickness (IMT) of the carotid artery. Eighty-four patients who had at least two conventional atherosclerosis risk factors and a control group of 50 patients having no risk factors for atherosclerosis were enrolled in the study. None of the patients had ever received HP eradication treatment. HP IgG antibodies were determined by enzyme-linked immunosorbent assay. Carotid artery IMT was measured 1 cm before the carotid bifurcation. Seventy-five percent of the study group was HP seropositive. HP seropositive ( n = 64) and seronegative ( n = 21) groups were identical in terms of sex distribution, smoking pattern, mean age, hemoglobin, leukocyte, platelet, C-reactive protein, erythrocyte sedimentation rate, glucose, cholesterol, triglyceride, low-density lipoprotein, high-density lipoprotein, systolic blood pressure and diastolic blood pressure levels. There was no significant difference between the mean carotid IMT of HP seropositive (0.8 +/- 0.3 mm) and negative ( 0.8 +/- 8 0.3 mm) patients in the study group. Similar to the study group, there was no statistically significant difference between mean carotid IMT of HP seropositive (0.56 +/- 0.19 mm) and negative patients (0.67 +/- 0.13 mm) in the control group ( p = 0.2). Future studies concerning virulent strains are needed to determine the probable role of HP in atherosclerosis. Copyright (C) 2004 S. Karger AG, Basel.Öğe Immobilization of a thermostable α-amylase onto reactive membranes: kinetics characterization and application to continuous starch hydrolysis(Elsevier Sci Ltd, 2004) Bayramoğlu, G.; Yilmaz, M.; Arica, M.Y.Epoxy groups containing porous membranes were prepared by UV-initiated photopolymerisation of hydroxyethylmethacrylate (HEMA) and glycidyl methacrylate (GMA). Epoxy supports could provide multipoint covalent attachment of enzymes, therefore, to stabilize their three-dimensional structure. alpha-Amylase was immobilized onto the poly(HEMA-GMA-1-3) membranes by means of the amide linkage formation between the amino groups of alpha-amylase and the epoxy groups of the support. The alpha-amylase immobilization capacity of the membranes was increased as the GMA ratio increased in the membrane structure. The retained activity of the immobilized alpha-amylase was 76% with poly(HEMA-GMA-2) membrane. The decrease in activity of the immobilized a-amylase could be considered to be due to reduced conformational flexibility of the immobilized alpha-amylase molecules for binding its large substrate, starch, as a result of the covalent immobilization. The immobilized alpha-amylase has more resistance to temperature inactivation than that of the free form. The optimum pH value of alpha-amylase was not affected by the immobilization reaction, but the pH profile was broadened for the immobilized enzyme. Kinetic parameters were determined for immobilized alpha-amylase as well as for the free enzyme. The values of the Michaelis constant K-m of alpha-amylase, were significantly larger (ca. 2.3 times) upon immobilization, indicating decreased affinity of the enzyme for its substrate, whereas V-max was smaller for immobilized a-amylase. In a 120 h continuous operation at 35 degreesC only 4% of immobilized alpha-amylase activity was lost. The operational inactivation rate constant (k(opi)) of the immobilized a-amylase with 2% starch was 8.06x 10(-6) min(-1). (C) 2003 Elsevier Ltd. All rights reserved.Öğe The role of fibroblast growth factor antisense in modulation of affective behaviour(Elsevier Science Bv, 2013) Eren-Kocak, E.; Yilmaz, M.; Basar, K.; Ayhan, Y.; Ozdemir, H.; Sen, Z. D.…Öğe Spallation neutron emission spectra in medium and heavy target nuclei by a proton beam up to 140 MeV energy(Pergamon-Elsevier Science Ltd, 2009) Kaplan, A.; Tel, E.; Aydin, E. G.; Aydin, A.; Yilmaz, M.In this study, neutron-emission spectra produced by (pxn) reactions for some spallation neutron target nuclei such as (65)Cu, (204.206.207.208)Pb, (209)Bi, (232)Th and (238)U have been calculated by a proton beam up to 140 MeV. Multiple pre-equilibrium mean free path constants from internal transition for (204,208)Pb (p, xn) neutron emission spectra have been investigated. In the calculations, pre-equilibrium effects were calculated by using new evaluated hybrid model and geometry dependent hybrid model, full exciton model and cascade exciton model. The reaction equilibrium component was calculated by Weisskopf-Evving model. The obtained results have been discussed and compared with the available experimental data and found agreement with each other. (C) 2009 Elsevier Ltd. All rights reserved.Öğe Synthesis and characterization of poly(glycerol-co-sebacate-co-epsilon-caprolactone) elastomers(Wiley-Blackwell, 2016) Aydin, H. M.; Salimi, K.; Yilmaz, M.; Turk, M.; Rzayev, Z. M. O.; Piskin, E.In this study, poly(glycerol-co-sebacate-co-epsilon-caprolactone) (PGSCL) elastomers were synthesized for the first time from the respective monomers. The structural analysis of PGSCL elastomers by nuclear magnetic resonance (H-1-NMR) and Fourier transform infrared spectroscopy (FTIR) revealed that the elastomers have a high number of hydrogen bonds and crosslinks. X-ray diffraction (XRD) and thermal analysis indicated an amorphous state. Differential scanning calorimetry (DSC) analysis showed that the elastomers has a glass transition temperature (T-g) of -36.96 degrees C. The Young's modulus and compression strength values were calculated as 46.08MPa and 3.192MPa, respectively. Calculations based on acid number and end groups analysis revealed a number average molecular weight of 148.15kDa. Even though the foaming studies conducted by using supercritical CO2 resulted in a porous structure; the obtained morphology tended to disappear after 48h, leaving small cracks on the surface. This phenomenon was interpreted as an indication of self-healing due to the high number of hydrogen bonds. The PGSCL elastomers synthesized in this study are flexible, robust to compression forces and have self-healing capacity. Thanks to good biocompatibility and poor cell-adhesion properties, the elastomers may find diverse applications where a postoperative adhesion barrier is required. Copyright (c) 2013 John Wiley & Sons, Ltd.
