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Dive into the research topics where Cem Kalayci is active.

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Featured researches published by Cem Kalayci.


European Journal of Clinical Investigation | 2010

Increased serum FGF21 levels in patients with nonalcoholic fatty liver disease

Yusuf Yilmaz; Fatih Eren; Oya Yonal; Ramazan Kurt; Bilge Aktas; Cigdem Ataizi Celikel; Osman Ozdogan; Nese Imeryuz; Cem Kalayci; Erol Avsar

Eur J Clin Invest 2010; 40 (10): 887–892


Scandinavian Journal of Gastroenterology | 2011

Serum levels of omentin, chemerin and adipsin in patients with biopsy-proven nonalcoholic fatty liver disease

Yusuf Yilmaz; Oya Yonal; Ramazan Kurt; Yesim Ozen Alahdab; Fatih Eren; Osman Ozdogan; Cigdem Ataizi Celikel; Nese Imeryuz; Cem Kalayci; Erol Avsar

Abstract Objective. The novel adipokines omentin, chemerin, and adipsin are associated with insulin resistance and the components of the metabolic syndrome. We assayed circulating levels of these molecules and examined their association with clinical, biochemical, and histological phenotypes in patients with nonalcoholic fatty liver disease (NAFLD). Material and methods. Serum levels of omentin, chemerin, and adipsin were assayed by enzyme-linked immunosorbent assay in 99 patients with biopsy-proven NAFLD and 75 control subjects. We analyzed associations between adipokines and the characteristics of patients with NAFLD using multivariable linear regression models. Results. Adipsin levels did not differ between patients and controls, whereas both omentin and chemerin levels were significantly higher in patients with biopsy-proven NAFLD than in controls (both p values <0.001). Serum omentin levels were significantly associated with C-reactive protein (r = 0.29, p < 0.01) and the degree of hepatocyte ballooning (r = 0.27, p < 0.01), whereas chemerin showed a modest association with liver fibrosis (r = 0.22, p = 0.04). After stepwise linear regression analysis adjusting for potential confounders, serum omentin levels retained their independent significance as a predictor of hepatocyte ballooning in patients with NAFLD (β = 1.42; t = 2.79, p < 0.01). Conclusions. Our results suggest that serum omentin levels are raised in patients with NAFLD regardless of potential confounders and represent an independent predictor of hepatocyte ballooning.


Journal of Clinical Gastroenterology | 2004

Prevalence of Hepatic Granulomas in Chronic Hepatitis B

Veysel Tahan; Resat Ozaras; Nadir Lacevic; Ercan Ozden; Mucahit Yemisen; Osman Ozdogan; Ali Mert; Fehmi Tabak; Erol Avsar; Cigdem Ataizi Celikel; Gulsen Ozbay; Cem Kalayci; Hakan Senturk; Nurdan Tozun

An increasing frequency of hepatic granulomas, up to 10%, in chronic hepatitis C patients is reported, and their presence is considered to be a predictor of treatment success. However, there is only one prevalence study on granuloma in chronic hepatitis B, and its significance for treatment outcome is unknown. We aimed to determine the prevalence of hepatic granulomas in a larger group of chronic hepatitis B patients and to compare their presence with the response to interferon therapy. Biopsy specimens of chronic hepatitis B patients were reevaluated for the presence of hepatic granulomas. All patients with hepatic granuloma were screened for other granulomatous diseases by tuberculin skin test, chest X-ray and computed tomography, venereal disease research laboratory, Brucella agglutination tests, and exposure to hepatotoxic agents. We screened 663 cases of chronic hepatitis B. Hepatic granulomas were found in 10 cases (1.5%). The granulomas could not be ascribed to any other reason. Of the 10 patients with hepatic granulomas, 4 responded to interferon therapy, 2 dropped out, and 4 were nonresponders. We conclude that hepatic granuloma is a rare finding in chronic hepatitis B and its presence does not seem to predict the response to interferon therapy.


Metabolism-clinical and Experimental | 2010

Microalbuminuria in nondiabetic patients with nonalcoholic fatty liver disease: association with liver fibrosis.

Yusuf Yilmaz; Yesim Ozen Alahdab; Oya Yonal; Ramazan Kurt; Alla Eldeen Kedrah; Cigdem Ataizi Celikel; Osman Ozdogan; Deniz Güney Duman; Nese Imeryuz; Erol Avsar; Cem Kalayci

Recent evidence has suggested an association between microalbuminuria and ultrasound-diagnosed nonalcoholic fatty liver disease (NAFLD) in patients with diabetes and prediabetes. However, few data are available on the occurrence of microalbuminuria in nondiabetic subjects with histologically proven NAFLD. We thus evaluated the relationships between microalbuminuria and liver histology in a hospital-based sample of 87 adults with biopsy-proven NAFLD from Turkey. An albumin excretion rate less than 30 mg/d was considered within the reference range, whereas an albumin excretion rate from 30 to 300 mg/d was considered to indicate microalbuminuria. Compared with those without microalbuminuria (n = 73), NAFLD patients with microalbuminuria (n = 14) had significantly higher homeostasis model assessment of insulin resistance values (3.9 +/- 1.3 vs 5.8 +/- 3.7, P < .001). There were no differences in the prevalence of microalbuminuria in patients with definite nonalcoholic steatohepatitis, borderline nonalcoholic steatohepatitis, and simple fatty liver. In the entire study cohort, mean fibrosis scores were significantly higher in patients with microalbuminuria than in those without (1.27 +/- 0.26 vs 0. 80 +/- 0.11, P < .05). This difference persisted after adjustment for potential confounders. These results indicate the presence of a significant association between the severity of insulin resistance and microalbuminuria in patients with NAFLD. In addition, microalbuminuria may identify NAFLD patients with higher fibrosis scores.


Atherosclerosis | 2010

Coronary flow reserve is impaired in patients with nonalcoholic fatty liver disease: Association with liver fibrosis

Yusuf Yilmaz; Ramazan Kurt; Oya Yonal; Nihat Polat; Cigdem Ataizi Celikel; Ahmet Gurdal; Huseyin Oflaz; Osman Ozdogan; Nese Imeryuz; Cem Kalayci; Erol Avsar

BACKGROUND Nonalcoholic fatty liver disease (NAFLD) is associated with an increased risk of cardiovascular disease. Coronary flow reserve (CFR) is widely used to examine the integrity of coronary microvascular circulation. We evaluated the prevalence of impaired CFR in patients with biopsy-proven NAFLD. We also investigated the independent clinical, biochemical, and liver histology predictors of CFR in the setting of NAFLD. METHODS Fifty-nine consecutive patients with NAFLD and 77 age- and gender-matched controls were evaluated. CFR recordings were performed by transthoracic Doppler harmonic echocardiography. CFR>or=2.0 was considered normal. RESULTS CFR was significantly lower in patients with NAFLD than in controls (2.11+/-0.45 vs. 2.52+/-0.62, P<0.001). An impaired CFR (i.e. <2) was found in 25 NAFLD patients (42.4%) whereas all controls had normal CFR values (P<0.001). A stepwise linear regression analysis in NAFLD patients identified liver fibrosis scores as the only independent predictor of CFR values (beta=-0.60; t=-2.44, P=0.021). CONCLUSION Our findings indicate that in patients with biopsy-proven NAFLD: (a) an abnormal CFR is found in approximately 42.4% of cases, and (b) liver fibrosis scores are an independent predictor of depressed CFR.


Metabolism-clinical and Experimental | 2011

Serum levels of vaspin, obestatin, and apelin-36 in patients with nonalcoholic fatty liver disease.

Bilge Aktas; Yusuf Yilmaz; Fatih Eren; Oya Yonal; Ramazan Kurt; Yesim Ozen Alahdab; Cigdem Ataizi Celikel; Osman Ozdogan; Nese Imeryuz; Cem Kalayci; Erol Avsar

The novel adipokines vaspin, obestatin, and apelin-36 are associated with insulin resistance and the components of the metabolic syndrome. We assayed circulating levels of these molecules and examined their association with clinical, biochemical, and histologic phenotypes in patients with nonalcoholic fatty liver disease (NAFLD). Serum levels of vaspin, obestatin, and apelin-36 were assayed by enzyme-linked immunosorbent assay in 91 patients with biopsy-proven NAFLD and 81 controls. We analyzed associations between adipokines and the characteristics of patients with NAFLD using multivariable linear regression models. Univariable analysis showed that concentrations of vaspin and apelin-36 were significantly higher in patients with NAFLD than in controls, whereas no differences in obestatin levels were found. Serum vaspin levels showed a statistically significant association with C-reactive protein (r = 0.378, P < .001) and liver fibrosis scores (r = 0.401, P < .001), whereas apelin-36 levels showed a modest association with homeostasis model assessment of insulin resistance (r = 0.204, P < .01). After stepwise linear regression analysis, serum vaspin levels were the only independent predictor of liver fibrosis scores in patients with NAFLD (β = 0.37, t = 3.99, P < .01). Serum vaspin levels are raised in patients with NAFLD regardless of potential confounders and represent an independent predictor of liver fibrosis scores. These findings support further investigation of this novel adipokine in metabolic liver diseases.


Annals of Clinical Biochemistry | 2010

Serum fetuin A/α2HS-glycoprotein levels in patients with non-alcoholic fatty liver disease: relation with liver fibrosis

Yusuf Yilmaz; Oya Yonal; Ramazan Kurt; Ferda Ari; Arzu Yilmaztepe Oral; Cigdem Ataizi Celikel; Seniz Korkmaz; Engin Ulukaya; Osman Ozdogan; Nese Imeryuz; Erol Avsar; Cem Kalayci

Background Serum concentrations of fetuin A/α2HS-glycoprotein (AHSG) have been linked to human metabolic alterations and can serve as an indicator of liver cell function. We assayed serum levels of AHSG in patients with non-alcoholic fatty liver disease (NAFLD), a hepatic manifestation of the metabolic syndrome, and examined their association with clinical, biochemical and histological phenotypes. Methods Serum AHSG levels were determined by enzyme linked immunosorbent assay in 99 patients with biopsy-proven NAFLD and 75 age- and gender-matched controls. Results Serum AHSG levels were significantly higher in patients with NAFLD (940 ± 120 μg/mL) compared with healthy controls (800 ± 130 μg/mL, Students t test, P < 0.001). Bivariate analyses (Spearmans rank correlation) in patients with NAFLD showed a statistically significant association between AHSG levels and insulin resistance as assessed by the HOMA (homeostasis model assessment) index (r = 0.31, P < 0.01) and the liver fibrosis score index (r = 0.36, P < 0.001). The association between AHSG and fibrosis remained statistically significant even after adjustment for potential confounders, including the HOMA index ([beta] = 1.65, t = 2.38, P < 0.05). Conclusion Serum AHSG levels are significantly increased in adult patients with biopsy-proven NAFLD and are associated with insulin resistance. Importantly, our pilot data indicate that serum AHSG levels may identify NAFLD patients with higher fibrosis scores.


BMC Gastroenterology | 2004

Botulinum toxin injection versus lateral internal sphincterotomy in the treatment of chronic anal fissure: a non-randomized controlled trial

Adnan Giral; Kemal Memişoğlu; Yücel Gültekin; Nese Imeryuz; Cem Kalayci; Nefise B. Ulusoy; Nurdan Tozun

BackgroundAlthough lateral internal sphincterotomy is the gold-standard treatment for chronic anal fissure, intrasphincteric injection of botulinum toxin seems to be a reliable new option. The aim of this non-randomized study is to compare the effect of lateral internal sphincterotomy and botulinum toxin injection treatments on the outcome and reduction of anal sphincter pressures in patients with chronic anal fissure.MethodsPatients with chronic anal fissure were treated with either botulinum toxin injection or lateral internal sphincterotomy by their own choice. Maximal resting pressure and maximal squeeze pressure measurements were performed before and 2 weeks after treatments by anal manometry. Patients were followed for fissure relapse during 14 months.ResultsTwenty-one consecutive outpatients with posterior chronic anal fissure were enrolled. Eleven patients underwent surgery and ten patients received botulinum toxin injection treatment. Before the treatment, anal pressures were found to be similar in both groups. After the treatment, the maximal resting pressures were reduced from 104 ± 22 mmHg to 86 ± 15 mmHg in the surgery group (p < 0.05) and from 101 ± 23 mmHg to 83 ± 24 mmHg in the botulinum toxin group (p < 0.05). The mean maximal squeeze pressures were reduced from 70 ± 27 mmHg to 61 ± 32 mmHg (p > 0.05) in the surgery group, and from 117 ± 62 mmHg to 76 ± 34 (p < 0.01) in the botulinum toxin group. The fissures were healed in 70 percent of patients in the botulinum group and 82 percent in the surgery group (p > 0.05). There were no relapses during the 14 months of follow up.ConclusionLateral internal sphincterotomy and botulinum toxin injection treatments both seem to be equally effective in the treatment of chronic anal fissure.


European Journal of Clinical Investigation | 2012

Characterization of nonalcoholic fatty liver disease unrelated to the metabolic syndrome

Yusuf Yilmaz; Ebubekir Senates; Talat Ayyildiz; Yasar Colak; Ilyas Tuncer; Ayşe Oya Kurdaş Övünç; Enver Dolar; Cem Kalayci

Eur J Clin Invest 2012; 42 (4): 411–418


Antimicrobial Agents and Chemotherapy | 2007

Pegylated interferon alfa-2b monotherapy and pegylated interferon alfa-2b plus lamivudine combination therapy for patients with hepatitis b virus e antigen-negative chronic hepatitis b

Sabahattin Kaymakoglu; Dilek Oguz; Gurden Gur; Selim Gurel; Ethem Tankurt; Galip Ersoz; Seren Ozenirler; Cem Kalayci; Sule Poturoglu; Yilmaz Cakaloglu; Atilla Ökten

ABSTRACT Forty-eight hepatitis B virus (HBV) E antigen-negative chronic hepatitis B patients received pegylated interferon alfa-2b either alone or with lamivudine for 48 weeks and were followed for an additional 24 weeks. At the end of follow-up, virological response rates (HBV DNA levels of <400 copies/ml) were similar in the monotherapy (24%) and combination therapy (26%) groups.

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