Mehmet Yalniz
Fırat University
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Featured researches published by Mehmet Yalniz.
Mediators of Inflammation | 2006
Huseyin Ataseven; Ibrahim Halil Bahcecioglu; Nalan Kuzu; Mehmet Yalniz; Selman Çelebi; Ahmet Erensoy; Bilal Ustundag
Background/Aim. Malnutrition, a common problem in liver cirrhosis and HCC, may readily deteriorate the clinical functions with resultant poor prognosis. Beside the hyper catabolic state frequently encountered in chronic liver disease and HCC, anorexia and reduced food intake also worsen the malnutrition. The recently discovered peptide hormone ghrelin acts as a counterpart of leptin in regulation of food intake and fat utilization. The aim of the present study was to investigate the ghrelin and leptin levels in cirrhosis and HCC due to hepatitis B and D viruses, and the association of ghrelin and leptin with TNF-α, IL-6 and the severity of the disease. Materials and methods. We measured serum ghrelin, leptin, TNF-α, and IL-6 levels using specific immunoassay in 45 patients (23 cirrhosis, 22 HCC) with HBV and/or HDV and in 25 control subjects. Results. In comparison to controls, serum ghrelin, TNF-α, and IL-6 levels were significantly higher in cirrhosis and HCC (P < .05), whereas serum leptin levels were found decreased (P < .05). There was a positive correlation between ghrelin and TNF-α, and a negative correlation between leptin and TNF-α (P < .05). Conclusion. In cirrhosis and HCC due to HBV or HDV, serum ghrelin levels were increased with a corresponding decrease in serum leptin concentrations, acting as a physiological counterpart of ghrelin. The increasing of ghrelin is more prominent in Child C cirrhosis and the level was correlated with TNF-α. The presence of nutritional and metabolic abnormalities, including malnutrition, in cirrhosis and HCC may, at least partly, elucidate high ghrelin and low leptin levels.
Journal of Gastroenterology and Hepatology | 2007
Mehmet Yalniz; Ibrahim Halil Bahcecioglu; Nalan Kuzu; Orhan Kursat Poyrazoglu; Ozgur Bulmus; Selman Çelebi; Bilal Ustundag; Ibrahim Hanefi Ozercan; Kazim Sahin
Background and Aim: The aim of the present study was to evaluate the preventive role of genistein, a phytoestrogen with a wide variety of pharmacological effects, in an experimental non‐alcoholic steatohepatitis (NASH) model.
Mediators of Inflammation | 2007
Nalan Kuzu; Kerem Metin; Adile Ferda Dagli; Fatih Akdemir; Cemal Orhan; Mehmet Yalniz; Ibrahim Hanifi Ozercan; Kazim Sahin; Ibrahim Halil Bahcecioglu
Aim. In the present study, we investigated the protective effect of genistein in experimental acute liver damage induced by CCl4. Method. Forty rats were equally allocated to 5 groups. The first group was designated as the control group (group 1). The second group was injected with intraperitoneal CCl4 for 3 days (group 2). The third group was injected with subcutaneous 1 mg/kg genistein for 4 days starting one day before CCl4 injection. The fourth group was injected with intraperitoneal CCl4 for 7 days. The fifth group was injected with subcutaneous 1 mg/kg genistein for 8 days starting one day before CCl4 injection. Plasma and liver tissue malondialdehyde (MDA) and liver glutathione levels, as well as AST and ALT levels were studied. A histopathological examination was conducted. Results. Liver tissue MDA levels were found significantly lower in group 3, in comparison to group 2 (P < .05). Liver tissue MDA level in group 5 was significantly lower than that in group 4 (P < .001). Liver tissue glutathione levels were higher in group 5 and 3, relative to groups 4 and 2, respectively (P > .05 for each). Inflammation and focal necrosis decreased in group 3, in comparison to group 2 (P < .001 for each). Inflammation and focal necrosis in group 5 was lower than that in group 4 (P < .001). Actin expression decreased significantly in group 5, relative to group 4 (P < .05). Conclusion. Genistein has anti-inflammatory and antinecrotic effects on experimental liver damage caused by CCl4. Genistein reduces liver damage by preventing lipid peroxidation and strengthening antioxidant systems.
International Journal of Clinical Practice | 2009
Orhan Kursat Poyrazoglu; Ibrahim Halil Bahcecioglu; Adile Ferda Dagli; Huseyin Ataseven; S. Celebi; Mehmet Yalniz
Objective: Heterotopic gastric mucosa (HGM) is found in the cervical oesophagus, just below the upper oesophageal sphincter, and has generally been overlooked by endoscopists. The objective of the present study is to determine endoscopic prevalence and histopathological and clinical characteristics of HGM and to classify patients according to their clinicopathological features.
Mediators of Inflammation | 2006
Mehmet Yalniz; Ibrahim Halil Bahcecioglu; Huseyin Ataseven; Bilal Ustundag; Fulya Ilhan; Orhan Kursat Poyrazoglu; Ahmet Erensoy
Adipokines and ghrelin play role in insulin resistance, the key pathophysiological abnormality in patients with nonalcoholic fatty liver diseases. In the present study, relationship between nonalcoholic steatohepatitis (NASH) and serum adipokine and ghrelin levels was investigated. Thirty seven patients with biopsy-proven NASH and 25 age- and sex-matched controls were enrolled. Ten of NASH patients (27%) had diabetes mellitus (n = 5) or impaired glucose tolerance (n = 5). Body mass index (BMI) was less than 30 kg/m2 in 67.6% of patients, while in the remaining 32.4% it was more than 30 kg/m2. Serum adiponectin, leptin, TNF-α, and ghrelin were determined. Serum leptin (15.49 ± 4.84 vs 10.31 ± 2.53) and TNF-α (12.1 ± 2.7 vs 10.31 ± 2.56) levels were significantly higher in the NASH group compared to in the control group (P < .001 for each). Nevertheless, adiponectin (11.1±2.1 vs 17.3±2.8) and ghrelin (6.46±1.1 vs 7.8±1.1) levels were lower in the NASH group than in the control group (P < .001 for each). Serum levels of the adipokines and ghrelin, however, were comparable in the subgroups of patients regardless of whether BMI was < 30 or > 30 or glucose tolerance was impaired or not (P > .05). Additionally, neither adipokines nor ghrelin was correlated with histopathological grade and stage (P > .05). In conclusion; there is a significant relationship between NASH and adipokines and ghrelin independent from BMI and status of the glucose metabolism. These cytokines that appear to have role in the pathogenesis of NASH, however, do not have any effect upon the severity of the histopathology.
Journal of Viral Hepatitis | 2011
Ibrahim Halil Bahcecioglu; Cem Aygun; Nevzat Gözel; O. K. Poyrazoglu; Y. Bulut; Mehmet Yalniz
Summary. Hepatitis delta virus (HDV) is a serious cause of liver‐related morbidity and mortality. Coexistent infection with HDV tends to aggravate the course of hepatitis B virus (HBV)‐associated liver disease. The aim of this study was to determine the prevalence of HDV infection among patients chronically infected with HBV in the Elazig region, which is in eastern Turkey. A group of 282 patients infected with chronic HBV were investigated for the study. Anti‐HDV seropositivity was evaluated in all patients. The anti‐HDV‐positive patients were further tested for HDV RNA. Severity of liver disease was assessed by liver biopsy. Regression analysis was used to determine the relationship between independent variables and HDV positivity. Of 282 chronic HBV patients, 192 were men (68.1%) and 90 were women (31.9%). The mean age was 43.8 ± 12.7 (between 18 and 73 years). Anti‐HDV was positive in 45.5% of the patients (128/282). Among the 128 anti‐HDV‐positive patients, 116 were checked for HDV RNA and 56.9% were found positive (66/116). Chronic HDV infection rate was therefore present in at least 23.4% of the whole study group (66/282). There were 83 patients with cirrhosis (29.4%) in the study group. Anti‐HDV seroprevalence and HDV RNA presence were higher in those with cirrhosis (61.4% and 42.2%, respectively). No significant relationship was found between anti‐HDV seropositivity and demographic factors such as age, sex and operation or transfusion history except family history. HDV‐RNA‐positive patients had significantly higher ALT and lower albumin levels when compared to HDV‐RNA‐negative patients. HDV‐RNA‐positive patients also had a significantly higher fibrosis stage. In conclusion, these findings demonstrated that HDV infection is endemic and still a serious problem in the Elazig region of eastern Turkey. HDV infection is significantly related to the family exposure and increases the risk of severe liver fibrosis in this region.
Journal of Digestive Diseases | 2008
Orhan Kursat Poyrazoglu; Mustafa Timurkaan; Mehmet Yalniz; Huseyin Ataseven; Muruvvet Dogukan; Ibrahim Halil Bahcecioglu
OBJECTIVE: To better identify which clinical, laboratory, radiological and invasive procedures were most useful in diagnosing tuberculous peritonitis and to assess the methods in order to reach the diagnosis in future cases.
Inflammation | 2012
Ulvi Demirel; Mehmet Yalniz; Cem Aygun; Cemal Orhan; Mehmet Tuzcu; Kazim Sahin; Ibrahim Hanifi Ozercan; Ibrahim Halil Bahcecioglu
Oxidative stress plays important role in the development of acute liver failure. In this study, we investigated effects of allopurinol (AP) upon thioacetamide (TAA)-induced liver injury and the potential mechanisms leading to amelioration in inflammation with AP treatment. Acute liver failure was induced by intraperitoneal administration of TAA (300 mg/kg/day for 2 days). Thirty-five rats were divided into five groups as control (group 1), TAA (group 2), TAA + 25AP (group 3), TAA + 50 AP (group 4), and TAA + 100AP (group 5). The number of animals in each group was seven. At the end of the study, histopathological, biochemical, and western blot analysis were done. TAA treatment significantly increased serum levels of aminotransferases, liver malondialdehyde (MDA), nuclear factor-kappa B (NF-қB ), activator protein-1 (AP-1), tumor necrosis factor-alpha (TNF-α), cyclooxygenase-2 (COX-2) and interleukin-6 (IL-6) levels, and the necro-inflammation scores. Nevertheless, nuclear factor E2-related factor-2 and heme oxygenase-1 (HO-1) expressions in the liver were decreased by TAA. AP treatment significantly lowered the serum levels of aminotransferases (P < 0.01) and liver MDA, NF-κB, AP-1, TNF-α, COX-2, and IL-6 expressions (P < 0.05). Moreover, AP restored the liver Nrf2 and HO-1 expressions and improved the necro-inflammation scores significantly. AP improves oxidative stress-induced liver damage by regulating cellular redox-sensitive transcriptor factors and expression of pro-inflammatory and antioxidant defense mechanisms. AP probably exerts these beneficiary features by its free radical scavenging ability in a dose-dependent manner.
Renal Failure | 2006
Orhan Kursat Poyrazoglu; Ayhan Dogukan; Mehmet Yalniz; Dilara Seckin; Ali lhsan Gunal
Objective. Atherosclerotic cardiovascular diseases caused by traditional and non-traditional risk factors are the most common cause of morbidity and mortality in hemodialysis patients. Recently, much interest has been focused on non-traditional factors, such as oxidative stress, inflammation, and endothelial dysfunction. Hemodialysis patients are not only exposed to oxidative stress but also to inflammation. Although anticoagulants are the most frequently used drugs in hemodialysis patients, their effect upon oxidative stress and inflammation in dialysis patients are still unknown. Methods. Thirty-three hemodialysis patients were randomized into three groups. Group 1 received standard heparin while group 2 received low molecular weight heparin during the dialysis therapy. Group 3 (control group) did not receive any anticoagulant agent. Investigators were blinded to the therapy. Serum concentrations of oxidative stress and inflammation markers, including C-reactive protein, tumor necrosis factor alpha, superoxide dismutase, and malondialdehyde, were measured before and after dialysis session. Results. The oxidative stress and inflammation markers were significantly increased in groups 1 and 3 (p < 0.05 for each) compared to their baseline values. In contrast, baseline and end-treatment values of the oxidative stress and inflammation markers were comparable in the group 2 (p > 0.05). Conclusion. These findings indicate that the type of anticoagulants may take a role in the acute effect of hemodialysis upon oxidative stress and inflammation markers. A comparison of the groups revealed that low molecular weight heparin decreased the oxidative stress and inflammation, whereas standard heparin increased the oxidative stress and inflammation. Low molecular weight heparin appears to have an additive benefit for hemodialysis patients.
International Journal of Clinical Practice | 2004
Ibrahim Halil Bahcecioglu; Mehmet Yalniz; Necip Ilhan; Huseyin Ataseven; Ibrahim Hanifi Ozercan
The aims of our study were to estimate serum levels of malondialdehyde (MDA), serum levels of vitamin A and alpha‐tocopherol as antioxidants and determine relationship of these with histopathologic severity in patients with non‐alcoholic steatohepatitis (NASH).