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Featured researches published by Hakim Celik.


BMC Infectious Diseases | 2005

Increased oxidative stress associated with the severity of the liver disease in various forms of hepatitis B virus infection

Cengiz Bolukbas; Fusun Filiz Bolukbas; Mehmet Aslan; Hakim Celik; Ozcan Erel

BackgroundOxidative stress can be defined as an increase in oxidants and/or a decrease in antioxidant capacity. There is limited information about the oxidative status in subjects with hepatitis B virus infection. We aimed to evaluate the oxidative status in patients with various clinical forms of chronic hepatitis B infection.MethodsSeventy-six patients with hepatitis B virus infection, in whom 33 with chronic hepatitis, 31 inactive carriers and 12 with cirrhosis, and 16 healthy subjects were enrolled. Total antioxidant response and total peroxide level measurement, and calculation of oxidative stress index were performed in all participants.ResultsTotal antioxidant response was significantly lower in cirrhotics than inactive HbsAg carriers and controls (p = 0.008 and p = 0.008, respectively). Total peroxide level and oxidative stress index was significantly higher in cirrhotic (p < 0.001, both) and chronic hepatitis B subjects (p < 0.001, both) than inactive HbsAg carriers and controls. Total antioxidant response was comparable in chronic hepatitis B subjects, inactive HbsAg carriers and controls (both, p > 0.05/6). Total peroxide level and oxidative stress index were also comparable in inactive HBsAg carriers and controls (both, p > 0.05/6). Serum alanine amino transferase level was positively correlated with total peroxide level and oxidative stress index only in chronic hepatitis B subjects (p = 0.002, r = 0.519 and p = 0.008, r = 0.453, respectively).ConclusionOxidative stress occurs secondarily to increased total lipid peroxidation and inadequate total antioxidant response and is related to severity of the disease and replication status of virus in hepatitis B infection.


Nutrition | 2010

Effect of pistachio diet on lipid parameters, endothelial function, inflammation, and oxidative status: A prospective study

Ibrahim Sari; Yasemin Baltaci; Cahit Bagci; Vedat Davutoglu; Ozcan Erel; Hakim Celik; Orhan Ozer; Nur Aksoy; Mehmet Aksoy

OBJECTIVE Recent studies have suggested that nuts have favorable effects beyond lipid lowering. We aimed to investigate effect of the Antep pistachio (Pistacia vera L.) on blood glucose, lipid parameters, endothelial function, inflammation, and oxidation in healthy young men living in a controlled environment. METHODS A Mediterranean diet was administered to normolipidemic 32 healthy young men (mean age 22 y, range 21-24) for 4 wk. After 4 wk, participants continued to receive the Mediterranean diet but pistachio was added for 4 wk by replacing the monounsaturated fat content constituting approximately 20% of daily caloric intake. Fasting blood samples and brachial endothelial function measurements were performed at baseline and after each diet. RESULTS Compared with the Mediterranean diet, the pistachio diet decreased glucose (P<0.001, -8.8+/-8.5%), low-density lipoprotein (P<0.001, -23.2+/-11.9%), total cholesterol (P<0.001, -21.2+/-9.9%), and triacylglycerol (P=0.008, -13.8+/-33.8%) significantly and high-density lipoprotein (P=0.069, -3.1+/-11.7%) non-significantly. Total cholesterol/high-density lipoprotein and low-density lipoprotein/high-density lipoprotein ratios decreased significantly (P<0.001 for both). The pistachio diet significantly improved endothelium-dependent vasodilation (P=0.002, 30% relative increase), decreased serum interleukin-6, total oxidant status, lipid hydroperoxide, and malondialdehyde and increased superoxide dismutase (P<0.001 for all), whereas there was no significant change in C-reactive protein and tumor necrosis factor-alpha levels. CONCLUSION In this trial, we demonstrated that a pistachio diet improved blood glucose level, endothelial function, and some indices of inflammation and oxidative status in healthy young men. These findings are in accordance with the idea that nuts, in particular pistachio nuts, have favorable effects beyond lipid lowering that deserve to be evaluated with prospective follow-up studies.


Progress in Neuro-psychopharmacology & Biological Psychiatry | 2008

Oxidative imbalance in obsessive compulsive disorder patients: A total evaluation of oxidant–antioxidant status

Salih Selek; Hasan Herken; Mahmut Bulut; Mehmet Fatih Ceylan; Hakim Celik; Haluk A. Savas; Ozcan Erel

OBJECTIVES Various psychological, social, genetic, biochemical, factors are to be involved in the etiology of OCD. Some molecules of free radicals are also found to play role in OCD. To the best of our knowledge, there has been no study, regarding the role of free radicals in the pathogenesis of OCD, from a general antioxidant aspect of view. Therefore, in this present cross-sectional study, we aimed to assess whether antioxidant-oxidant status is associated with OCD and can be used or not as a biological marker regarding that disorder. METHODS 37 OCD patients diagnosed according to DSM-IV and as control group forty healthy subjects were included to the study. Venous blood samples were collected once. The total oxidant status, antioxidant status and oxidative stress index of the plasma were measured using a novel automated colorimetric measurement method. RESULTS There was not a significant difference between only OCD and all patients in all measures (TOS: Z = - 1.453, p = 0.521; TAS: Z = - 0.151, p = 0.880; OSI: Z = - 0.679 p = 0.497). TAS levels were both higher than controls in only OCD groups and all patients (Z = - 5.538, p < 0.001 and Z = - 6.394, p < 0.001 respectively). TOS and OSI of both patient groups were significantly lower than controls (TOS: Z = - 5.131, p < 0.001; OSI: Z = - 5.105, p < 0.001 and TOS: Z = - 5.979, p < 0.001; OSI: Z = - 5.862, p < 0.001). In only OCD group, illness duration was correlated with TOS and OSI (r(0) = 0.44, p = 0.023, n = 26 and r(0) = 0.44, p = 0.026, n = 26 respectively) but not with TAS. CONCLUSION Our study found an overall oxidative imbalance shifted towards antioxidant side in OCD which may be due to either a rebound phenomenon or chronicity of the condition.


Redox Report | 2006

Total antioxidant capacity and the severity of the pain in patients with fibromyalgia

Özlem Altındağ; Hakim Celik

Abstract The purpose of the study was to determine the oxidative and antioxidative status of plasma in patients with fibromyalgia. Total antioxidant capacity (TAC) of plasma was significantly lower in patients with fibromyalgia (n = 20) than in healthy controls (n = 20) [1.5 (SD 0.3) and 1.9 (SD 0.3) mmol Trolox equiv./l, P = 0.001]. In contrast, the total peroxide level of plasma was significantly higher in patients than in healthy controls [37.4 (SD 6.7) and 33.0 (SD 2.7) μmol H2O2/l; P = 0.01]. The oxidative stress index (OSI) level was significantly higher in patients with fibromyalgia than in healthy controls [2.5 (SD 1.0) and 1.8 (SD 0.4); P = 0.007]. A significant negative correlation between visual analogue scale (VAS) and TAC level was determined (r = −0.79, P < 0.001). The present results indicate that patients with fibromyalgia are exposed to oxidative stress and this increased oxidative stress may play a role in the etiopathogenesis of the disease. Supplementation of antioxidant vitamins such as vitamins C and E to the therapy may be indicated.


Archives of Gynecology and Obstetrics | 2006

No increase in sperm DNA damage and seminal oxidative stress in patients with idiopathic infertility

Fatma Ferda Verit; Ayhan Verit; Halil Ciftci; Hakim Celik; Mete Koksal

The most common cause of male infertility is idiopathic. Standard investigations reveal no abnormality in such cases. The aim of the study was to investigate the levels of sperm DNA damage and seminal oxidative stress and their relationships with idiopathic infertility. The study included 30 normozoospermic infertile men seeking infertility treatment and 20 fertile donors. Semen analysis was performed according to the World Health Organization guidelines. Sperm DNA damage was assessed by alkaline single cell gel electrophoresis (comet assay) after preparation with two-step discontinuous Percoll gradient. Seminal oxidative stress was measured by a novel automated method. DNA damage score, total antioxidant status (TAS), total oxidant status (TOS) and oxidative stress index (OSI) were not different in idiopathic infertile men compared with controls. No correlations were also found between DNA damage score and TAS, TOS levels and OSI in idiopathic infertile group. We did not find any relationship between sperm DNA damage and oxidative stress in normozoospermic infertile men. We think that the pathophysiology of idiopathic infertility cannot be explained by sperm DNA damage or seminal oxidative stress.


European Journal of Endocrinology | 2010

Non-diabetic metabolic syndrome and obesity do not affect serum paraoxonase and arylesterase activities but do affect oxidative stress and inflammation

Suzan Tabur; Ayse Nur Torun; Tevfik Sabuncu; Mehmet Nuri Turan; Hakim Celik; Ali Rıza Ocak; Nurten Aksoy

OBJECTIVE Paraoxonase-1 (PON-1), which has PON and arylesterase activities, is a high-density lipoprotein (HDL)-bound antioxidant enzyme that inhibits atherosclerosis. Diabetes has been shown to have an impact on oxidative stress. The effect of metabolic syndrome (MetS) on oxidative stress and PON-1 has been shown before, and PON-1 has been found to be related with accelerated atherogenesis. This study aimed to determine the oxidative state and PON and arylesterase activities in non-diabetic MetS and non-MetS obese patients. DESIGN Thirty obese patients (3 M and 27 F) without MetS, 40 non-diabetic obese patients (3 M and 37 F) with MetS, and 30 controls (2 M and 28 F) were enrolled. METHODS A 75 g glucose tolerance test was performed. PON-1, PON, arylesterase, total antioxidant status (TAS), high-sensitive C-reactive protein (hsCRP), and metabolic parameters were analyzed. RESULTS PON and arylesterase activities were similar between the groups, while TAS was low in both MetS and obese groups compared to controls (P<0.01 and P<0.05 respectively). CRP was higher in the MetS group compared with the obese and control groups (P<0.01 and P<0.001 respectively). In both the obese and MetS groups, CRP showed a positive correlation with body mass index (BMI). TAS was negatively correlated with BMI, waist circumference, triglyceride levels, and systolic and diastolic blood pressures (P<0.001). CONCLUSIONS Oxidative stress is altered in non-diabetic MetS and non-MetS obese patients, but PON and arylesterase activities seem not to be affected. This result may be due to the absence of diabetes, the most severe form of altered carbohydrate metabolism.


Gynecologic Oncology | 2009

Serum paraoxonase and arylesterase activities in patients with epithelial ovarian cancer

Hakan Camuzcuoglu; Dagistan Tolga Arioz; Harun Toy; Sefa Kurt; Hakim Celik; Ozcan Erel

OBJECTIVE The HDL-associated paraoxonase and arylesterase activities play a role in decreasing oxidative stress, which is known to contribute to cancer development. The aim of this study was to evaluate serum paraoxonase and arylesterase activities and lipid hydroperoxide (LOOH) levels in patients with newly-diagnosed epithelial ovarian cancer. MATERIALS Serum paraoxonase and arylesterase activities, total free sulfhydryl (-SH) levels and LOOH levels were measured in patients with epithelial ovarian cancer (n=24) and controls (n=29). RESULTS Serum paraoxonase activity and arylesterase activity, as well as -SH levels were significantly lower (p=0.003, p<0.001 and p<0.001, respectively) in patients with epithelial ovarian cancer compared to controls, while LOOH levels were significantly higher (p<0.001). A significant inverse correlation was found between the stage, grade and CA-125 level of ovarian cancer and paraoxonase activity (rho=-0.630, p=0.001 and rho=-0.601, p=0.002 and rho=-0.436, p=0.033, respectively), arylesterase activity (rho=-0.601, p=0.002 and rho=-0.713, p<0.001 and rho=-0.580, p=0.003, respectively), and -SH levels (rho=-0.642, p=0.001 and rho=-0.637, p=0.001 and rho=-0.530, p=0.008, respectively). In contrast, there was a positive correlation between LOOH and the stage, grade and CA-125 level of ovarian cancer (rho=0.565, p=0.004 and rho=0.479, p=0.018 and rho=0.642, p=0.001). CONCLUSION Our results suggest that diminished paraoxonase and arylesterase activity, -SH levels and increased LOOH levels are associated with particular stage, grade and CA-125 level of ovarian cancer.


International Journal of Neuroscience | 2008

Role of Oxidative and Antioxidative Parameters in Etiopathogenesis and Prognosis of Panic Disorder

Mehmet Akif Ersoy; Salih Selek; Hakim Celik; Ozcan Erel; Mehmet Cemal Kaya; Haluk A. Savas; Hasan Herken

Free radicals have been implicated in some psychiatric disorders. This study aimed to investigate the role of oxidative and antioxidative parameters in etiopathogenesis and prognosis of panic disorder (PD), using novel methods for measurement of total oxidant and antioxidant statuses. Nineteen PD patients and 40 healthy subjects were recruited. Both total antioxidant status and oxidative stress index, and ceruloplasmin levels of PD patients were significantly higher in PD patients. Total oxidant status and oxidative stress index decreased after treatment. This study suggests an oxidative imbalance in PD and treatment can reverse overall oxidative imbalance.


Journal of Pineal Research | 2007

Melatonin protects from ischemia/reperfusion‐induced renal injury in rats: this effect is not mediated by proinflammatory cytokines

Zehra Kurcer; Elif Oguz; Hatice Ozbilge; Fusun Baba; Nurten Aksoy; Hakim Celik; Hale Cakir; Mehmet Rıza Gezen

Abstract:  The pathophysiologic mechanisms leading to acute ischemic renal failure are not completely understood. Melatonin, a compound with well‐known antioxidant properties, reduces IR‐induced renal injury. The purpose of the present study was to investigate the changes in levels of tumor necrosis factor (TNF)‐α, IL‐β, and IL‐6 in postischemic reperfused renal tissue, and to determine whether the protective effect of melatonin is related the modulation of the production of these inflammatory molecules. Male Wistar albino rats were unilaterally nephrectomized and subjected to 1 hr of renal pedicle occlusion followed by 2 hr or 24 hr of reperfusion. Melatonin (10 mg/kg, i.p.) or vehicle was administrated at 10 min prior to ischemia. After 24 hr of the reperfusion, following decapitation, kidney samples were taken both for histologic examination and for the determination of malondialdehyde (MDA), myeloperoxidase (MPO) activity, total antioxidant capacity (TAC), total oxidative stress (TOS), creatinine, and blood urea nitrogen (BUN). These were measured in serum samples. TNF‐α, IL‐β, and IL‐6 were measured in kidney samples after 2 hr of reperfusion. IR caused a significant increase in renal MDA, MPO, TOS, creatinine, and BUN while decrease TAC without any change in TNF‐α, IL‐β, and IL‐6 levels. Melatonin treatment reduced the biochemical indices without any change in the cytokine levels and ameliorated histopathologic alterations induced by IR. The protective effect of melatonin on IR‐induced renal injury is related to its antioxidant properties but not to proinflammatory cytokines.


Renal Failure | 2010

Protective Effects of Nigella sativa against Ischemia-Reperfusion Injury of Kidneys

Fahrettin Yildiz; Sacit Coban; Alpaslan Terzi; Murat Savas; Muharrem Bitiren; Hakim Celik; Nurten Aksoy

Background. Ischemia-reperfusion, commonly seen in the fields of trauma surgery and renal transplantation, is a major cause of acute kidney injury and is associated with significant morbidity and mortality. The protective effects of Nigella sativa against ischemia-perfusion damage to various organs have been previously documented. However, its protective effects on kidney tissue against ischemia-reperfusion injury are unclear. In this study, we aimed to examine the effect of Nigella sativa in modulating inflammation and apoptosis after renal I/R injury. Materials and methods. Thirty male Wistar-albino rats were divided into three groups: sham-operated, ischemia-reperfusion, and ischemia-reperfusion + Nigella sativa. Rats in the third group were given Nigella sativa 6 h prior to ischemia-reperfusion and at the beginning of reperfusion. All rats except those in the sham-operated group underwent 45 min of bilateral renal ischemia followed by 45 min of reperfusion. Blood samples and liver tissues were harvested from the rats, and then rats were sacrificed. Serum urea and creatinine levels were determined. Total antioxidant capacity (TAC), catalase (CAT), total oxidant status (TOS), oxidative stress index (OSI), and myeloperoxidase (MPO) in kidney tissue and blood were measured. Kidney tissue histopathology was also evaluated. Results. Nigella sativa was effective in reducing serum urea and creatinine levels as well as decreasing the tubular necrosis score. Nigella sativa treatment significantly reduced OSI and TOS levels and increased TAC levels in both kidney tissue and blood. Conclusion. The observed differences seem to demonstrate the protective effect of Nigella sativa against renal I/R injury in rat kidneys.

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Ozcan Erel

Yıldırım Beyazıt University

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