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Featured researches published by Ercan Tuncel.


Journal of Endocrinological Investigation | 2010

The effect of vitamin D replacement therapy on insulin resistance and androgen levels in women with polycystic ovary syndrome

Hadi Selimoglu; Cevdet Duran; Sinem Kiyici; Canan Ersoy; Metin Guclu; Guven Ozkaya; Ercan Tuncel; Erdinc Erturk; Sazi Imamoglu

Insulin resistance (IR) is one of the common features of the polycystic ovary syndrome (PCOS), and recent studies indicate the possible role of vitamin D in the pathogenesis of IR and glucose metabolism. Aim of this study was aimed to determine the effect of vitamin D replacement therapy on glucose metabolism, insulin, and androgen levels in obese, insulin-resistant women with PCOS. Eleven women with PCOS were included in the study. Mean age of the patients was 23.6±5.7 yr, body mass index 33.9±5.1 kg/m2. Six patients (54.5%) had acantosis nigricans and 10 (90.9%) oligoamenorrhea. The mean Ferriman Gallwey score was 14.1 ±4.6. Only 2 women were within the normal limits of vitamin D levels as >20 ng/ml. Three weeks after the administration of the single dose of 300,000 units of vitamin D3 orally, 25-hydroxyvitamin D3 significantly increased from 16.9±16 ng/ml to 37.1 ±14.6 ng/ml (p: 0.027) and only 2 women were detected to have vitamin D3 levels <20 ng/ml. Although glucose and insulin levels were decreased non-significantly, homeostasis model assesment (HOMA)-IR significantly decreased from 4.41 ±1.38 to 3.67±1.48 (p: 0.043). No significant alterations were witnessed at the levels of DHEAS, total and free testosterone, androstenedione. No correlation was found between vitamin D with HOMA and other hormonal parameters. In conclusion, women with PCOS have mostly insufficient vitamin D levels, and vitamin D replacement therapy may have a benefical effect on IR in obese women with PCOS.


American Journal of Roentgenology | 2006

Value of Chemical Shift Subtraction MRI in Characterization of Adrenal Masses

Gursel Savci; Neslin Sahin; Semra Akgöz; Ercan Tuncel

OBJECTIVE The purpose of this study was to assess the advantages of the image subtraction technique in chemical shift MRI for the differentiation of adrenal adenomas from nonadenomas. SUBJECTS AND METHODS Thirty-five patients with 42 adrenal masses (eight metastases and 34 nonfunctioning adenomas) underwent chemical shift MRI using a double-echo fast low-angle shot sequence. Subsequently, opposed-phase chemical shift MR images were subtracted from in-phase images. The subtraction images were assessed quantitatively and qualitatively. For quantitative assessment, the signal intensity values of the adrenal masses were measured by one investigator with manually defined regions of interest. Qualitative assessment of the subtraction images was performed independently by two investigators, who reported their confidence in diagnosing adenomas versus nonadenomas based on signal intensity of the adrenal masses on subtraction images. RESULTS The mean signal intensities were significantly different between adenomas and metastases on subtraction images (213 vs 18; p < 0.0001). There was no overlap in signal intensities between adenomas and metastatic tumors. The accuracy in distinguishing adenomas from metastatic tumors was 100% if the cutoff value of the signal intensity selected was 36-106. Quantitative results corresponding to 100% specificity were also observed, with similar sensitivity. No difference in interpretation between the two investigators occurred. CONCLUSION Chemical shift subtraction MRI provides a high confidence level in distinguishing adrenal adenomas from adrenal metastases. The image subtraction technique also facilitates quantitative and qualitative evaluation of adrenal masses in chemical shift MRI.


European Radiology | 1998

Assessment of depth of myometrial invasion by endometrial carcinoma: comparison of T2-weighted SE and contrast-enhanced dynamic GRE MR imaging

Gursel Savci; T. Ozyaman; M. Tutar; T. Bilgin; O. Erol; Ercan Tuncel

A prospective study was undertaken to assess the value of both T2-weighted spin-echo (SE) and contrast-enhanced dynamic gradient-echo (GRE) sequences using MR imaging in differentiating the deep myometrial invasion from lower stages produced by endometrial carcinoma. For the correlation of MR findings with the histopathologic findings, patients who had no myometrial invasion (stage 1 a) and patients in whom tumors were confined to the superficial myometrium (stage 1 b) at pathologic examination were combined as lower stages. Twenty patients with endometrial carcinoma were studied using both techniques. The absence of any detectable tumor (stage 1 a) or the presence of a tumor confined to inner half of myometrium (stage 1 b) and extention of tumor to the outer half of myometrium (stage 1 c) were used as the diagnostic criteria. In pathologic examination of excised specimens, deep myometrial invasion was detected in 9 of 20 patients. The sensitivity, specificity, accuracy, positive predictive values (PPV) and negative predictive values (NPV) of T2-weighted SE in differentiating deep myometrial invasion from combined lower stages were 88, 91, 90, 88, and 91 %, respectively, whereas corresponding values for contrast-enhanced dynamic GRE sequences were 78, 100, 90, 100, and 85 %. Statistical difference between two sequences did not reach a significant level. We conclude that in cases of absence of visible junctional zone with SE sequence, contrast-enhanced dynamic GRE MR imaging may be helpful.


Mutation Research-genetic Toxicology and Environmental Mutagenesis | 2009

Evaluation of chromosome aberrations, sister chromatid exchange and micronuclei in patients with type-1 diabetes mellitus

Nilufer Cinkilic; Sinem Kiyici; Serap Celikler; Ozgur Vatan; Ozen Oz Gul; Ercan Tuncel

Oxidative stress-induced DNA damage seems to play a role in the pathogenesis of type-1 diabetes mellitus and its complications. Several in vitro assays have been used to measure the DNA damage produced by oxidative stress. In the present study, we aimed to investigate the frequency of sister chromatid exchange (SCE), chromosomal aberrations (CA) and micronuclei (MN) in type-1 diabetes mellitus patients compared with healthy controls. SCE, CA and MN tests were carried out with the blood-cell cultures from 35 type-1 diabetic patients and 15 healthy, age- and sex-matched control subjects. The mean age of the type-1 diabetic patients was 31.89 +/- 10.01 years, with a mean duration of the diabetes of 7.8 +/- 6.02 years. The mean level of HbA1c of the type-1 diabetic patients was 8.37+/-1.36%. Only three (8.5%) patients with type-1 diabetes mellitus had an HbA1c level below 7%. Patients with type-1 diabetes mellitus showed a higher frequency of SCE compared with controls (5.44 +/- 1.47 and 2.54 +/- 0.82, respectively, p < 0.001), but there was no significant correlation between the duration of diabetes, HbA1c and SCE. No significant difference was found in CA or MN frequency in type-1 diabetic patients compared with controls. In conclusion, these results suggest that type-1 diabetes mellitus is a condition with genomic instability characterized by an increased level of SCE. Hyperglycemia-induced oxidative stress may be the underlying factor of the increased SCE frequency.


Korean Journal of Radiology | 2010

Role of Duplex Power Doppler Ultrasound in Differentiation between Malignant and Benign Thyroid Nodules

Oktay Algin; Efnan Algin; Gokhan Gokalp; Gokhan Ocakoglu; Cuneyt Erdogan; Ozlem Saraydaroglu; Ercan Tuncel

Objective To evaluate the usage of duplex power Doppler ultrasound (PDUS) for the differentiation of benign and malignant thyroid nodules. Materials and Methods We prospectively examined 77 thyroid nodules in 60 patients undergoing ultrasound-guided fine needle aspiration biopsy (FNAB). Each nodule was described according to size, inner structure, borders, parenchymal echogenicity, peripheral halo formation, and the presence of calcification (B-mode ultrasound findings). Vascularity as determined by PDUS imaging was defined as non-vascular, peripheral, central, or of mixed type. For each nodule, the pulsatility index (PI) and resistive index (RI) values were obtained. Results of FNAB and surgical pathological examination (if available) were used as a proof of final diagnosis to categorize all nodules as benign or malignant. A receiver operating characteristic (ROC) curve analysis was performed to establish cut-off, sensitivity, and specificity values associated with RI-PI values. Results A significant relationship was observed between malignancy and irregular margins, microcalcifications, and hypoechogenicity on ultrasound examination (p < 0.05). The pattern of vascularity as determined by PDUS analysis was not a statistically significant criterion to suggest benign or malignant disease in this study (p > 0.05). The central, peripheral, and mean RI-PI values were higher in malignant nodules when compared to the other cytologies (p < 0.05). Conclusion Vascularity is not a useful parameter for distinguishing malignant from benign thyroid nodules. However, RI and PI values are useful in distinguishing malignant from benign thyroid nodules.


Diabetes Research and Clinical Practice | 2009

Effect of rosiglitazone, metformin and medical nutrition treatment on arterial stiffness, serum MMP-9 and MCP-1 levels in drug naive type 2 diabetic patients.

Sinem Kiyici; Canan Ersoy; Aysel Aydin Kaderli; Murat Fazlioglu; Ferah Budak; Cevdet Duran; Ozen Oz Gul; Deniz Sigirli; İbrahim Baran; Ercan Tuncel; Erdinc Erturk; Sazi Imamoglu

The aim of the study was to evaluate the long-term effect of rosiglitazone and metformin monotherapy with medical nutrition treatment (MNT) and of MNT alone on arterial stiffness, serum monocyte chemoattractant protein (MCP)-1 and matrix metalloproteinase (MMP)-9 in drug naive patients with type 2 diabetes mellitus. Fifty type 2 diabetic patients were randomized to receive rosiglitazone 4 mg/day (n=19) or metformin 850 mg/day (n=16) with MNT or MNT alone (n=15), for 52 weeks. Arterial stiffness was assessed by using large and small artery elasticity index (SAEI and LAEI, respectively). SAEI, LAEI, serum MCP-1 and MMP-9 levels were measured at baseline and following 52 weeks of treatment. SAEI was improved only in the rosiglitazone group, and the difference was still statistically significant when the three groups were compared (p=0.024). There were no differences in LAEI in inter- and intragroup comparisons at the end of the study. Serum MMP-9 levels were decreased in the metformin (-13.5+/-34.8%, p=0.02) and rosiglitazone (-27.2+/-51.0%, p=0.023) groups compared with baseline values, whereas no significant change was seen in serum MCP-1 levels. These results suggest that rosiglitazone monotherapy has favorable effects on arterial stiffness compared with metformin monotherapy independent of glycemic control.


European Radiology | 1997

Polyarteritis nodosa presenting with hemobilia and intestinal hemorrhage.

Gursel Savci; Mufit Parlak; Ercan Tuncel

Abstract Polyarteritis nodosa is a multisystem disease primarily involving the small and medium-sized vessels. Prognosis depends on the presence and severity of visceral involvement. Thrombosis and aneurysm formation commonly occur in kidney and gastrointestinal tract. Although hepatic involvement is also common, hepatic aneurysmal rupture with intrahepatic or perihepatic hematoma formation is infrequent. Hemobilia secondary to aneurysmal rupture is a very rare condition. We present a case of polyarteritis nodosa accompanied by hemobilia and intestinal hemorrhage secondary to hepatic and mesenteric aneurysmal rupture.


Metabolism-clinical and Experimental | 2010

Comparative effects of pioglitazone and rosiglitazone on plasma levels of soluble receptor for advanced glycation end products in type 2 diabetes mellitus patients

Ozen Oz Gul; Ercan Tuncel; Yusuf Yilmaz; Engin Ulukaya; Cuma Bulent Gul; Sinem Kiyici; Arzu Yilmaztepe Oral; Metin Guclu; Canan Ersoy; Sazi Imamoglu

Low levels of soluble receptor for advanced glycation end products (sRAGE) have been associated with the occurrence of vascular complications in patients with type 2 diabetes mellitus. Preliminary evidence has suggested that thiazolidinediones have the ability to modulate circulating levels of this molecule in the hyperglycemic milieu. The aim of this pilot study was to assess the differential effect of 2 different thiazolidinediones-pioglitazone and rosiglitazone-on plasma levels of sRAGE in type 2 diabetes mellitus patients. Sixty type 2 diabetes mellitus subjects were randomly assigned to receive pioglitazone (30 mg/d, n = 19), rosiglitazone (4 mg/d, n = 20), or placebo (medical nutrition therapy, n = 21) for 12 weeks. Changes in plasma glucose, glycosylated hemoglobin, insulin resistance (homeostasis model assessment), total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides, and sRAGE were evaluated at baseline and after 12 weeks. At 12 weeks, the pioglitazone (P < .001) group had a significant increase from baseline in sRAGE values that was not seen in the medical nutrition therapy and rosiglitazone groups. We conclude that, in type 2 diabetes mellitus patients, pioglitazone-but not rosiglitazone-significantly raised sRAGE, which may contribute to its antiatherogenic effects.


European Radiology | 1996

Solid and papillary epithelial neoplasm of the pancreas: CT and MR findings

Gursel Savci; S. Kilicturgay; Z. Sivri; Mufit Parlak; Ercan Tuncel

Solid and papillary epithelial neoplasm of the pancreas is a very rare low-grade malignant neoplasm with only 126 cases reported in the literature and seen mostly in young female patients. Surgical excision means cure in cases before malignant degeneration developed. Its characteristic findings are typical location in the tail of the pancreas, peripheral capsule formation, hypodensity on CT images, and hyperintense internal signal characteristics on T1-weighted MR images secondary to hemorrhage and accumulation of methemoglobine molecule. These findings are enough for the preoperative diagnosis that may lead to early surgery and cure. We present the CT and MR findings of this very rare neoplasm in a case report.


Experimental and Clinical Endocrinology & Diabetes | 2009

Total and acylated ghrelin levels in type 2 diabetic patients: similar levels observed after treatment with metformin, pioglitazone or diet therapy.

Sinem Kiyici; Canan Ersoy; O. Oz Gul; Emre Sarandol; M. Demirci; Ercan Tuncel; Deniz Sigirli; Erdinc Erturk; Sazi Imamoglu

Ghrelin, a potent gut-brain orexigenic peptide, has a role in stimulation of food intake and long-term regulation of body weight. Metformin and pioglitazone treatment have different effects on body weight. This discrepancy might be related with the effect of these two drugs on plasma ghrelin levels. We investigated the effect of these two drugs on post-prandial acylated and total ghrelin levels in patients with type 2 diabetes. Eleven patients treated with diet, 12 patients treated with 850 mg/day metformin monotherapy and 12 patients treated with 30 mg/day pioglitazone monotherapy for at least 6 months were enrolled in the study. Plasma acylated and total ghrelin levels were investigated at baseline and at the 60 (th), 120 (th), 180 (th), 240 (th) minutes after a mixed meal test. There were no differences between groups in any of baseline metabolic and anthropometric parameters, including acylated and total ghrelin levels. Acylated and total ghrelin concentrations were suppressed similarly after food consumption, and we could not determine any significant difference between the groups at any time interval. A prolonged postprandial suppression of acylated ghrelin concentrations was observed in the pioglitazone treatment group compared with baseline values. In conclusion, total and acylated ghrelin levels after a mixed meal test were similar in type 2 diabetic patients treated with metformin, pioglitazone or diet therapy alone. These results suggest that changes in body weight during metformin and pioglitazone treatment are not associated with plasma ghrelin levels.

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