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Featured researches published by Ayhan Zengi.


Experimental and Clinical Endocrinology & Diabetes | 2008

Oxidative Stress Markers in Young Patients with Polycystic Ovary Syndrome, The Relationship between Insulin Resistances

Muammer Karadeniz; Mehmet Erdogan; Sadik Tamsel; Ayhan Zengi; Gülinnaz Alper; Osman Caglayan; Fusun Saygili; Candeger Yilmaz

OBJECTIVE Polycystic ovary syndrome is a syndrome of ovarian dysfunction. Oxidative stress, inflammation and endothelial cell activation are thought to play concomitant roles in the pathogenesis of the above diseases particularly in the development of atherosclerotic lesions. RESEARCH DESIGN AND METHODS We studied 58 polycystic ovary syndrome patients and age-matched 25 healthy controls consisting of women that have regular, ovulatory cycles and normal androgen levels. Homeostasis Model Assessment-Insulin Resistance for this study was taken as 1.75 that is the upper level of confidence interval of %95 of the mean of the healthy group. PCOS patients were divided into two groups as for below the cut-off level (<1.75) and above the cut-off level (> or =1.75). hs-CRP, fibrinogen, malondialdehyde, nitric oxide and disulfide level results were compared both in PCOS and control groups. RESULTS In this study, sensitive CRP was found to be statical significantly higher in polycystic ovary syndrome groups whose Homeostasis Model Assessment-Insulin Resistance were > or =1.75 and <1.75 when compared to the control group. But, no significantly correlation was determined between malondialdehyde, nitric oxide and disulfide levels and CRP elevation. CONCLUSIONS In our study, because those participants were young and non- obese patients with PCOS, malondialdehyde, nitric oxide and disulfide levels and Carotid Artery Intima-Media Thickness measurements as a pre-indicator of cardiovascular disease were not found to be different from those of the controls.


Experimental and Clinical Endocrinology & Diabetes | 2011

Increased oxidative DNA damage in lean normoglycemic offspring of type 2 diabetic patients.

Ayhan Zengi; G. Ercan; O. Caglayan; S. Tamsel; Muammer Karadeniz; I. Simsir; E. Harman; C. Kahraman; M. Orman; Sevki Cetinkalp; G. Ozgen

OBJECTIVE Several studies have shown increased oxidative stress in patients with pre-diabetes and newly diagnosed Type 2 diabetes mellitus (T2DM). It has been proposed that oxidative stress initiates insulin resistance in genetically predisposed individuals. The aim of this study was to evaluate the markers of oxidative stress in the offspring of patients with T2DM. MATERIAL AND METHODS We examined 60 lean normoglycemic offspring of Type 2 diabetics, and 52 age, sex and body mass index matched subjects without family history of T2DM as controls. Anthropometric, biochemical and carotid intima media thickness (IMT) measurements and oral glucose tolerance test (OGTT) were performed. Erythrocyte superoxide dismutase and glutathione peroxidase activities, serum nitric oxide, plasma total sulfhydryl (tSH) groups, plasma total antioxidant status, plasma malondialdehyde and serum 8-hydroxydeoxy-guanosine (8-OHdG) levels were compared between 2 groups. RESULTS 2 groups were similar for the measurements of anthropometric, blood pressure, lipids, fasting glucose, HOMA-IR and carotid IMT. Glucose levels during OGTT were significantly higher in the offspring of Type 2 diabetics than controls (p=0.035). The offspring of Type 2 diabetics showed a significant increase in serum 8-OHdG level (p=0.005) and plasma tSH groups (p=0.032) when compared to the controls. Significant differences were not obtained in other oxidative stress marker levels between 2 groups. CONCLUSION Main finding of our study was the presence of increased oxidative DNA damage in lean normoglycemic offspring of Type 2 diabetic patients. There is a need for further clinical studies in order to explain whether oxidative stress is present in genetically predisposed subjects and induces the insulin resistance.


Journal of Assisted Reproduction and Genetics | 2009

Apolipoprotein E gene polymorphism and polycystic ovary syndrome patients in Western Anatolia, Turkey

Sevki Cetinkalp; Muammer Karadeniz; Mehmet Erdogan; Ayhan Zengi; Vildan Bozok Çetintaş; Asli Tetik; Zuhal Eroglu; Buket Kosova; A. Gökhan Özgen; Fusun Saygili; Candeger Yilmaz

PurposeDyslipidemia, cardiovascular disease and hypertension are more frequently seen in patients with PCOS than in normal patients. We aimed at evaluating the distribution of Apo E alleles that can influence cardiovascular risk of the PCOS patients and control subjects.MethodsIn this study, 129 young women with PCOS and 91 healthy women were included. In all subjects we performed hormonal, biochemical and Apo E genetic analysis.ResultsThe Apo E3 allele was found at a significantly higher frequency in the PCOS patient group compared with the control group. The Apo E2 allele was found at a significantly higher frequency in the control group compared with the patient group with PCOS.ConclusionsAlthough there were genotype and allele differences between control and patient groups in this study, no statistically significant change was determined in lipid and other cardiovascular risk factors in connection with allele and genotype.


International Journal of Immunogenetics | 2008

Polymorphism of the interleukin‐10 gene in polycystic ovary syndrome

Muammer Karadeniz; Mehmet Erdogan; Ayhan Zengi; Sadik Tamsel; Afig Berdeli; Fusun Saygili; Candeger Yilmaz

Interleukin (IL)‐10 is a major anti‐inflammatory cytokine that has been associated with obesity and type 2 diabetes. We aimed to evaluate the IL‐10 gene polymorphisms in polycystic ovary syndrome (PCOS) and control subjects. Ninety‐one young women with PCOS and 74 healthy control women were included in our study. All subjects underwent venous blood drawing for complete hormonal assays, lipid profile, glucose, insulin and IL‐10 gene polymorphism genetic analysis and carotid intimae media thickness (CIMT) were measured. The genotype and allele frequencies showed similar ratios between both the control and the patient group. The AA and AG genotypes in IL‐10 polymorphism seemed to be relatively high, but statistically no significant difference has been detected in GG genotype. Our results show that IL‐10 gene polymorphism of PCOS patients has no effect on inflammatory markers, metabolic parameters (fasting insulin, fasting glucose, HOMA‐IR), carotid intimae media thickness and Ferriman‐ Gallwey scoring. These data will be different in PCOS patients with different ethnical origin.


Journal of Endocrinological Investigation | 2009

The relation of adiponectin and tumor necrosis factor α levels between endothelial nitric oxide synthase, angiotensin-converting enzyme, transforming growth factor β, and tumor necrosis factor α gene polymorphism in adrenal incidentalomas

E. Harman; Muammer Karadeniz; C. Biray; Ayhan Zengi; Sevki Cetinkalp; A. G. Ozgen; Fusun Saygili; Afig Berdeli; Cumhur Gunduz; C. Yilmaz

Objective: The aim of our study was to demonstrate demographic characteristics, presence of inflammatory markers, distribution of angiotensin-converting enzyme (ACE), tumor necrosis factor (TNF), endothelial nitric oxide synthase (eNOS) genotypes and relations among these parameters in these patients and control subjects. Research design and methods: Study samples were collected from 50 patients with adrenal mass and 30 control groups. The eNOS, ACE, TNF-α, transforming growth factor (TGF)-β genes polymorphisms, TNF-α, adiponectin levels were analysed in 50 unrelated Turkish patients with a diagnosis of adrenal incidentaloma (AI). Results: There was statistically significant difference between TNF-α levels of patient and controls (p=0.048). We have not detected the connection between TGF-β, TNF-α, ACE, eNOS gene polymorphism with serum TNF-α and adiponectin levels. In this study, we demonstrated that there were significant differences for ACE genotypes in the patients when compared to the controls (p<0.05). The percentages of the ID, DD, II genotypes for ACE gene polymorphism in the patients group were 30.0, 13.0, 7.0%, respectively. Conclusions: According to different cases of eNOS, TGF-β, ACE, and TNF-α gene genotypes; no statistical significant difference was found between basal cortisol, ACTH, DHEAS, metanephrine, renin, aldosterone, normetanephrine, 17-hydroxyprogesterone, 1 mg low-dose dexamethasone suppression test-cortisol response and AI size. In this study, I/D genotype was determined to be statistically higher in ACE gene in patients with AI (p=0.014).


Anatolian Journal of Cardiology | 2017

Polymorphisms of lipid metabolism enzyme-coding genes in patients with diabetic dyslipidemia

Aslı Tetik Vardarlı; Ece Harman; Vildan Bozok Çetintaş; Meral Kayikcioglu; Egemen Vardarlı; Ayhan Zengi; Ali Şahin Küçükaslan; Zuhal Eroglu

Objective: The polymorphisms/mutations of genes encoding proteins and enzymes involved in lipoprotein metabolism play important roles in the development of diabetic dyslipidemia. The aim of our study was to investigate the effects of LPL (rs320), LIPC (rs2070895), SCARB1 (rs5888), LCAT (rs2292318), CETP (rs708272), ADIPOQ (rs1501299), RETN (rs3745367), PON1 (rs662), and MNSOD (rs4880) gene polymorphisms on lipid metabolism and diabetic dyslipidemia. Methods: This case-control study included 217 patients with diabetic dyslipidemia and 212 healthy age- and gender-matched individuals. Genomic DNA isolation was performed from blood samples, and genotype analysis was performed using melting curve analysis on a LightCycler® 480 Instrument. The chi-square test was used to compare genotype distribution and allele frequencies between the groups. Results: Significant associations were observed between LPL (rs320) (p<0.001), LIPC (rs2070895) (p<0.001), SCARB1 (rs5888) (p<0.001), LCAT (rs2292318) (p<0.001), CETP (rs708272) (p<0.001), ADIPOQ (rs1501299) (p=0.01), RETN (rs3745367) (p<0.001), and MNSOD (rs4880) (p<0.001) polymorphisms and diabetic dyslipidemia. However, no association was observed between PON1 (rs662) polymorphisms and diabetic dyslipidemia (p=0.611). Conclusion: LPL (rs320), LIPC (rs2070895), SCARB1 (rs5888), LCAT (rs2292318), CETP (rs708272), ADIPOQ (rs1501299), RETN (rs3745367), and MNSOD (rs4880) polymorphisms play an important role in basic molecular metabolism in diabetic dyslipidemia. Therefore, these polymorphisms may be used as a predictive marker for diabetic dyslipidemia in high-risk patients. (Anatol J Cardiol 2017; 17: 313-21)


Genetic Testing and Molecular Biomarkers | 2013

Is there any association between the Ser326Cys polymorphism of the 8-oxoguanine glycosylase 1 (OGG1) gene and risk of colon polyp and abnormal glucose tolerance in acromegaly patients?

Ayhan Zengi; Muammer Karadeniz; Vildan Bozok Çetintaş; Ece Harman; Asli Tetik; Mehmet Orman; Zuhal Eroglu; Sevki Cetinkalp; A. G. Ozgen; Fusun Saygili; Candeger Yilmaz

AIM Evidence arising from experimental studies indicates an association between increased levels of the growth hormone/insulin-like growth factor 1 and oxidative stress. The association of the Ser326Cys polymorphism in the 8-oxoguanine glycosylase (OGG1) gene with a colon carcinoma and diabetes mellitus has been examined. The aim of the study was to compare the genotypic distribution of OGG1 Ser326Cys between acromegaly patients and nonacromegalic subjects and to explore whether this polymorphism is associated with a colon polyp risk and abnormal glucose tolerance. METHODS We examined 98 acromegaly patients, and 99 healthy subjects who can be compared in terms of age and gender. All participants were evaluated by anthropometric and biochemical measurements. Also, a 75-g oral glucose test and colonoscopy was applied to the patients. Genomic DNA was isolated from peripheral blood leucocytes and the genotype was assessed by melting temperature analyses after using a real-time polymerase chain reaction protocol. RESULTS Colon polyps were detected in 13 (30.2%) of 43 patients who underwent the colonoscopy. Except for diastolic blood pressure, clinical and biochemical characteristics were similar between the patients diagnosed with and without a colon polyp. A higher proportion of acromegaly patients had the Ser326Ser genotype when compared to the control group (p=0.007). Genotypes were similar between the patients with a normal glucose tolerance and an abnormal glucose tolerance (p=0.774). The frequency of the Cys allele was significantly higher in patients with polyps than those without a polyp (38.5% vs. 18.3%) (p=0.029). CONCLUSION Our results suggest that the Cys allele may influence the colon polyp risk in acromegaly patients. Large-scale studies with acromegaly patients are required to show whether being a carrier of the Cys allele is associated with the risk of a colorectal polyp.


Gynecological Endocrinology | 2012

Miscarriage, and TNF-α and osteopontin relationship in women patients with Hashimoto’s thyroiditis

Ece Harman; Muammer Karadeniz; Cigir Biray Avci; Ayhan Zengi; Mehmet Erdogan; Murat Yalcin; Sevki Cetinkalp; Ozgen Ahmet Gokhan; Cumhur Gunduz; Fusun Saygili; Candeger Yilmaz

Objective: Infertility and reproductive impairment can be compromised by abnormalities in both endocrine and immune system. TNF-α promotes apoptotic cell death in fetal membrane tissues and pro-inflammatory, proapoptotic, and procoagulant properties of TNF-α probably contribute to widely accepted abortogenic profile of this cytokine. The aim of this study was to assess the alteration in the levels of TSH, FT3, FT4, TNF-α, osteopontin in pregnant and controls. Methods: Study subjects were 28 pregnant women, 28 non-pregnant women, and 28 healthy controls. All subjects underwent venous blood drawing for levels of TNF-α, osteopontin, and also hormonal assays including the levels of anti-TPO, anti-TG antibodies, TSH, FT3, FT4. Results: Both patient and control groups are similar in terms of age. Pregnancy age in conceived patients is 23.64 ± 2.040. No statistically meaningful relation was found in correlation analysis between TNF-α and osteopontin among the groups (p = 0.963). Anti-thyroglobuline antibody and anti-microsomal antibody levels were found to be higher in patients with non-pregnant patients with Hashimoto thyroiditis than the control group (p < 0.001). No statistically meaningful relation was found in terms of TNF-α (p = 0.66) and osteopontin serum levels (p = 0.50) in patient groups with or without miscarriage history. Conclusions: In our study, no statistically meaningful relation was found in terms of TNF-α and osteopontin serum levels in patient groups with and without miscarriage history.


Endocrine | 2010

Methylenetetrahydrofolate reductase C677T gene polymorphism in turkish patients with polycystic ovary syndrome

Muammer Karadeniz; Mehmet Erdogan; Ayhan Zengi; Zuhal Eroglu; Sadik Tamsel; Murat Olukman; Fusun Saygili; Candeger Yilmaz


Endocrine Journal | 2008

Does Chernobyl Accident Have Any Effect on Thyroid Cancers in Turkey? a Retrospective Review of Thyroid Cancers from 1982 to 2006

Ayhan Zengi; Muammer Karadeniz; Mehmet Erdogan; A. G. Ozgen; Fusun Saygili; Candeger Yilmaz; Taylan Kabalak

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