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Dive into the research topics where Zulfikar Polat is active.

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Featured researches published by Zulfikar Polat.


Endocrine | 2002

Effects of postmenopausal hormone replacement therapy on insulin resistance

Kenan Saglam; Zulfikar Polat; M. Ilker Yilmaz; Mustafa Gulec; Seda Banu Akinci

Postmenopausal hormone replacement therapy (HRT) protects women from the risk of cardiovascular system disease, osteoporosis, and dementia. There are conflicting reports about the effects of HRT on insulin resistance. The purpose of this study was to investigate the effects of HRT on insulin resistance with the hyperinsulinemic euglycemic clamp technique, the most sensitive technique measuring insulin resistance. Conjugated estrogen (0.625 mg/d) and medroxyprogesterone acetate (5 mg/d) were given to 15 postmenopausal women with insulin resistance. After 3 mo of HRT, the M value (total glucose consumption) increased 28% (p<0.001), low-density lipoprotein (LDL) cholesterol decreased 12.9% (p<0.044), high-density lipoprotein (HDL) cholesterol increased 17% (p<0.009), total cholesterol decreased 9.1% (p<0.016), and serum insulin decreased 33% (p<0.022) compared to baseline values before HRT was started. No significant changes in glucose, C-peptide, and triglyceride levels were observed. Whereas there were no differences regarding glucose, total cholesterol, LDL cholesterol, HDL cholesterol, and triglyceride levels between the insulin-resistant (n=15) and non-insulin-resistant women (n=24) (p>0.05), there were significant differences in M value, insulin, and C-peptide levels between these groups (p<0.05). We believe that HRT with this combination may protect postmenopausal women from coronary artery disease (CAD) through its beneficial effects on insulin resistance, hyperinsulinemia, and lipid levels, which are considered to be important factors in CAD pathogenesis.


European Journal of Internal Medicine | 2012

Comparison of levofloxacin-containing sequential and standard triple therapies for the eradication of Helicobacter pylori

Zulfikar Polat; Abdurrahman Kadayifci; Murat Kantarcioglu; Ayhan Ozcan; Ozdes Emer; Ahmet Uygun

BACKGROUND There is an important concern about the success of standard triple treatment for Helicobacter pylori (H. pylori) in recent years. Better eradication rates have been reported with sequential treatment in current studies. This study aimed to compare the success of a novel levofloxacin-containing sequential regimen with standard triple therapy. METHODS H. pylori-positive patients with non-ulcer dyspepsia were randomly allocated to one of the study groups. The patients on sequential arm were given esomeprazole 40 mg BID and amoxicillin 1g BID for the first week followed by esomeprazole 40 mg BID, levofloxacin 500 mg QD and metronidazole 500 mg TID for the second week. The patients on standard triple arm were given esomeprazole 40 mg BID, amoxicillin 1g BID and clarithromycin 500 mg BID for 2 weeks. Eradication was assessed by urea breath test on 6th weeks. RESULTS Seventy-five patients were enrolled in each group; 72 in sequential arm and 67 in standard arm completed the protocols. H. pylori eradication rate of per protocol was 90% in sequential versus 57% in standard treatment groups with a statistical significance (p<0.000). Both regimens were similarly well tolerated and side effects were comparable. Only one patient in sequential arm stopped the treatment because of side effects. CONCLUSION The levofloxacin-containing sequential therapy is a significantly better strategy than the standard triple treatment for H. pylori eradication. Standard triple treatment is no more effective for H. pylori in our population and levofloxacin-containing sequential regimen might be used as a first-line eradication option.


Helicobacter | 2011

A New Modified Concomitant Therapy for Helicobacter pylori Eradication in Turkey

Ahmet Burak Toros; Ali T. Ince; Besir Kesici; Mustafa Saglam; Zulfikar Polat; Ahmet Uygun

Background:  Helicobacter pylori eradication rates have tended to decrease recently, mostly due to antibiotic resistance. In the present study, our aim was to determine Hp eradication rate with the LAC plus tid metronidazole regimen and the secondary objective of this study was to identify an effective regimen for our population.


Disease Markers | 2011

Serum progranulin as an independent marker of liver fibrosis in patients with biopsy-proven nonalcoholic fatty liver disease

Yusuf Yilmaz; Fatih Eren; Oya Yonal; Zulfikar Polat; Mohammad Bacha; Ramazan Kurt; Oguzhan Ozturk; Erol Avsar

Background: Elevated progranulin levels are associated with visceral obesity, elevated plasma glucose, and dyslipidemia. Progranulin has not been previously investigated as a biomarker of nonalcoholic fatty liver disease (NAFLD). We sought to determine whether serum progranulin levels are altered in patients with biopsy-proven NAFLD and if they are associated with their clinical, biochemical, and histological characteristics. Subjects and methods: We measured serum progranulin levels in 95 patients with biopsy-proven NAFLD and 80 age- and sex-matched controls. The potential associations between progranulin and the characteristics of NAFLD patients were examined by multiple linear regression analysis. Results: Serum progranulin levels were significantly higher in NAFLD patients (34 ± 13 ng/mL) than in controls (28 ± 7 ng/mL, P < 0.001). In NAFLD patients, serum progranulin levels were associated with lipid levels and the degree of hepatic fibrosis. After adjustment for potential confounders, serum progranulin remained an independent predictor of the degree of hepatic fibrosis in NAFLD patients (β = 0.392; t =2.226, P < 0.01). Conclusions: Compared with controls, NAFLD patients have higher serum progranulin concentrations, which are closely associated with lipid values and the extent of hepatic fibrosis.


European Journal of Internal Medicine | 2015

The effect of fatty pancreas on serum glucose parameters in patients with nonalcoholic steatohepatitis

Ahmet Uygun; Abdurrahman Kadayifci; Hakan Demirci; Mutlu Saglam; Yusuf Serdar Sakin; Kadir Ozturk; Zulfikar Polat; Yildirim Karslioglu; Erol Bolu

OBJECTIVE Fatty pancreas (FP) is related to obesity, and may have some clinical implications on glucose metabolism. The frequency and importance of FP in patients with nonalcoholic steatohepatitis (NASH) are not clear. This study aimed to investigate: the frequency of FP in patients with NASH, and its effects on serum glucose parameters. METHODS FP was detected and graded by transabdominal ultrasonography (USG) in patients with biopsy-proven NASH and healthy controls. Body Mass Index and waist circumference were recorded, and serum lipids, fasting serum glucose, HbA1c, OGTT 2-h, insulin level, insulin resistance, type 2 diabetes mellitus (DM) and prediabetes rates were detected. RESULTS Eighty-four subjects with NASH and 35 healthy controls were enrolled in the study. There was no FP in 41 (48.8%) of the NASH patients according to the study criteria. Forty-three of the NASH patients and 5 of the controls had different grades of fat in their pancreas (51.2% vs. 14%, p=0.001). The HbA1c and OGTT 2-h results were significantly higher in NASH patients with FP compared to those without FP (p=0.003 and p=0.018). The rates of both prediabetes and DM were also found to be significantly increased in NASH patients with FP (p=0.004). The mean waist circumference was higher in patients with FP (p=0.027). Grade of FP by USG showed no effect on study parameters in subgroup analysis. CONCLUSION FP is common in patients with NASH and increases the rate of prediabetes and DM. The coexistence of both NASH and FP has a further impact on glucose metabolism and DM frequency.


Journal of Surgical Oncology | 2014

Long-term results of endoscopic resection for type I gastric neuroendocrine tumors

Ahmet Uygun; Abdurrahman Kadayifci; Zulfikar Polat; Kemalettin Yilmaz; Armagan Gunal; Hakan Demir; Sait Bagci

A number of different therapies, including endoscopic resection, have been suggested for the treatment of Type 1 gastric neuroendocrine tumors (NETs). The current study aimed to determine the long‐term efficacy of endoscopic resection for Type 1 gastric NETs.


Stem Cells International | 2014

The efficacy of mesenchymal stem cell transplantation in caustic esophagus injury: an experimental study.

Murat Kantarcioglu; Bahadir Caliskan; Hakan Demirci; Ozgur Karacalioglu; Murat Kekilli; Zulfikar Polat; Armagan Gunal; Melih Akinci; Cagri A. Uysal; Sami Eksert; Hasan Gurel; Gurkan Celebi; Ferit Avcu; Ali Ugur Ural; Sait Bagci

Introduction. Ingestion of corrosive substances may lead to stricture formation in esophagus as a late complication. Full thickness injury seems to exterminate tissue stem cells of esophagus. Mesenchymal stem cells (MSCs) can differentiate into specific cell lineages and have the capacity of homing in sites of injury. Aim and Methods. We aimed to investigate the efficacy of MSC transplantation, on prevention of esophageal damage and stricture formation after caustic esophagus injury in rats. 54 rats were allocated into four groups; 4 rats were sacrificed for MSC production. Group 1, untreated controls (n: 10). Group 2, membrane labeled MSCs-treated rats (n: 20). Group 3, biodistribution of fluorodeoxyglucose labeled MSCs via positron emission tomography (PET) imaging (n: 10). Group 4, sham operated (n: 10). Standard caustic esophageal burns were created and MSCs were transplanted 24 hours after. All rats were sacrificed at the 21st days. Results. PET scan images revealed the homing behavior of MSCs to the injury site. The histopathology damage score was not significantly different from controls. However, we demonstrated Dil labeled epithelial and muscle cells which were originating from transplanted MSCs. Conclusion. MSC transplantation after caustic esophageal injury may be a helpful treatment modality; however, probably repeated infusions are needed.


Helicobacter | 2012

Efficacy of a Modified Sequential Therapy Including Bismuth Subcitrate as First-Line Therapy to Eradicate Helicobacter pylori in a Turkish Population

Ahmet Uygun; A. Melih Ozel; Bulent Sivri; Zulfikar Polat; Halil Genc; Yusuf Serdar Sakin; Gurkan Celebi; Oya Uygur-Bayramicli; Cemal Nuri Erçin; Abdurrahman Kadayifci; Ozdes Emer; Armagan Gunal; Sait Bagci

Eradication rates of Helicobacter pylori with standard triple therapy are not satisfactory. Sequential therapy is an alternative method to overcome this problem.


Clinical Biochemistry | 2011

Serum galectin-3 levels in patients with nonalcoholic fatty liver disease

Yusuf Yilmaz; Fatih Eren; Ramazan Kurt; Oya Yonal; Zulfikar Polat; Ebubekir Senates; Mohammad Bacha; Nese Imeryuz

OBJECTIVES Galectin-3 might serve as a biomarker of human metabolic alterations. We measured serum levels of galectin-3 in patients with nonalcoholic fatty liver disease (NAFLD) and examined their association with clinical and histological phenotypes. DESIGN AND METHODS Serum levels of galectin-3 were assayed in 71 patients with biopsy-proven NAFLD and 39 controls. RESULTS Serum galectin-3 levels did not differ in patients with NAFLD (median 4.1 ng/mL; interquartile range: 1.5-5.5 ng/mL) compared with healthy controls (median 3.1 ng/mL; interquartile range: 0.8-7.5 ng/mL, P=0.93). Among patients with NAFLD, however, serum galectin-3 levels correlated significantly with BMI (r=0.267, P<0.05). This association persisted after adjustment for potential confounders (β=0.30; t=2.11, P<0.05). CONCLUSIONS Although galectin-3 was modestly associated with BMI, our results do not support the hypothesis that levels of this molecule are altered in patients with NAFLD.


European Journal of Gastroenterology & Hepatology | 2015

The degree of mucosal damage to the small intestine and serum immunoglobulin G4 levels correlate with celiac disease.

Hakan Demirci; Zulfikar Polat; Kadir Ozturk; Murat Kekilli; Murat Kantarcioglu; Fatih Sahiner; Ahmet Uygun; Sait Bagci

Background Celiac disease (CD) is an immune-mediated and chronic inflammatory enteropathy, triggered by the ingestion of gluten in genetically susceptible individuals. Immunoglobulin G4 (IgG4)-related diseases are a recently defined emerging clinical condition, characterized by increased serum IgG4 concentrations. The aim of this study was to investigate whether IgG4 levels correlate with the titers of intestinal antibodies and the degree of mucosal damage in CD patients. Materials and methods A total of 41 CD patients and 28 healthy controls were included in the study. All patients underwent a duodenal biopsy and were then diagnosed with the modified Marsh classification. Blood samples were obtained for IgG4 measurements. Serums were kept at −80°C until the analysis was carried out and plasma IgG4 levels were determined using an enzyme-linked immune sorbent assay method with a diagnostic cutoff value of 135 mg/dl. Results The mean age of the CD and the control group was 26.8±8.3 and 26.9±6.2 years, respectively. The mean IgG4 levels were significantly higher in CD patients (283.21±39.02 mg/dl) compared with the healthy control group (68.97±15.89 mg/dl, P<0.0001). In the CD group, 27/41 patients and in the control group, 4/28 patients had high IgG4 levels (>135 mg/dl, P<0.0001). A close correlation was found between the grade of mucosal damage, IgG4 levels, and antigliadin-IgA; the higher the grade Marsh score, the higher the measured IgG4 (P<0.05). Conclusion In our study, IgG4 levels of CD patients were higher than normal ranges whereas the results of the control group were within physiologic limits. We also showed for the first time that there was a correlation between IgG4 levels, autoantibody, and severity of mucosal damage. To the best of our knowledge, this is the first study to evaluate IgG4 levels and mucosal damage in CD patients.

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Ahmet Uygun

Military Medical Academy

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Sait Bagci

Military Medical Academy

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Hakan Demirci

Military Medical Academy

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Ahmet Tüzün

Military Medical Academy

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Mustafa Gulsen

Military Medical Academy

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Kadir Ozturk

Military Medical Academy

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