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Dive into the research topics where Halit Demir is active.

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Featured researches published by Halit Demir.


Journal of International Medical Research | 2008

Catalase Activity, Serum Trace Element and Heavy Metal Concentrations, and Vitamin A, D and E Levels in Pre-eclampsia

Mertihan Kurdoglu; Recep Yildizhan; Ertan Adali; T Edirne; A Cebi; Halit Demir; İbrahim Yörük

Catalase (antioxidant enzyme) activity in erythrocytes and serum levels of trace elements (copper, iron, zinc), heavy metals (cadmium, cobalt) and vitamins A (retinol), D (cholecalciferol) and E (α-tocopherol) were measured in 145 subjects comprising 47 pre-eclamptic pregnant women (PE), 48 healthy pregnant women (HP) and 50 healthy non-pregnant controls (NP). Catalase, vitamins A, D and E and levels of cobalt were significantly lower in the PE group compared with the HP and NP groups, whereas levels of copper, iron and cadmium were significantly higher in the PE group than in the HP and NP groups. Levels of zinc were significantly lower in both the PE and HP groups compared with the NP group. This assessment of oxidant/antioxidant imbalance in pregnant women could be useful in the early identification of pre-eclampsia and antioxidant supplementation in the early weeks of gestation might be useful.


Biological Trace Element Research | 2011

The Correlation of Serum Trace Elements and Heavy Metals with Carotid Artery Atherosclerosis in Maintenance Hemodialysis Patients

Elif Ari; Yüksel Kaya; Halit Demir; Ebru Asicioglu; Sıddık Keskin

Changes in essential trace elements and heavy metals may affect the atherosclerotic state of patients on maintenance hemodialysis (HD). The aim of the study was to evaluate the relation between the serum levels of some trace elements and heavy metals (iron, zinc, manganese, copper, magnesium, cobalt, cadmium, lead, and copper/zinc ratio) and carotid artery intima–media thickness (CIMT) in HD patients. Fifty chronic HD patients without known atherosclerotic disease and 48 age- and sex-matched healthy individuals were included in the study. The serum levels of trace elements (iron, zinc, manganese, copper, and magnesium) and heavy metals (cobalt, cadmium, and lead) were measured by Atomic Adsorption Spectrophotometer (UNICAM-929). CIMT was assessed by carotid artery ultrasonography. The serum levels of iron, zinc, and manganese were lower; levels of copper, magnesium, cobalt, cadmium, lead, and copper/zinc ratio were higher in HD patients compared to controls. CIMT in HD patients were higher than the control group (0.64 ± 0.11 vs 0.42 ± 0.05, p < 0.001). There was a significant negative correlation between CIMT and serum levels of zinc (r = −0.70, p < 0.01), iron (r = −0.71, p < 0.01), and manganese (r = −0.47, p < 0.01), while there was a significant positive correlation between CIMT and serum levels of copper (r = 0.63, p < 0.01), magnesium (r = 0.77, p < 0.01), cobalt (r = 0.63, p < 0.01), cadmium (r = 0.48, p < 0.01), lead (r = 0.38, p < 0.01), and copper/zinc ratio (r = 0.68, p < 0.01). A linear regression analysis showed that serum levels of magnesium, cadmium, lead, and copper/zinc ratio were still significantly and positively correlated with CIMT. We propose that copper/zinc ratio, magnesium and toxic metals cadmium and lead are independent determinants of CIMT in maintenance HD patients without known atherosclerotic disease.


Biological Trace Element Research | 2006

Effect of black cumin (Nigella sativa) on heart rate, some hematological values, and pancreatic β-cell damage in cadmium-treated rats

Halit Demir; Mehmet Kanter; Omer Coskun; Yesim Hulya Uz; Ahmet Koc; Abdulmelik Yildiz

This study was designed to investigate the effect of Nigella sativa (NS) on the heart rate, some hematological values, and pancreatic β-cell damage in cadmium (Cd)-treated rats. The rats were randomly grouped into one of three experimental groups: Control, Cd treated, and Cd+NS treated. Each group contained 10 animals. The Cd-treated and Cd+NS-treated groups were injected subcutaneously daily with CdCl2 dissolved in isotonic NaCl in the amount of 2 mL/kg for 30 d, resulting in a dosage of 0.49 mg Cd/kg/d. The control group was injected with only isotonic NaCl (2 mL/kg/d) throughout the experiment (for 30 d). Three days prior to administration of CdCl2, the Cd+NS-treated group received the daily intraperitoneal (ip) injection of 2 mL/kg NS until the end of the study; animals in all three groups were fasted for 12 h and blood samples were taken for the determination of the glucose and insulin levels, red blood cell (RBC) and white blood cell (WBC) counts, packet cell volume (PCV), and hemoglobin (Hb) concentration. The heart rates of rats were also measured by a direct writing electrocardiograph before the blood withdrawals. It was found that NS treatment increased the lowered insulin levels, RBC and WBC counts, PCV, and neutrophil percentage in Cd-treated rats. However, the WBC count of Cd-treated rats with NS treatment was still lower than those of control values. NS treatment also decreased the elevated heart rate and glucose concentration of Cd-treated rats. Pancreatic tissues were also harvested from the sacrificed animals for morphological and immunohistochemical examinations. Cd exposure alone caused a degeneration, necrosis, and weak degranulation in the β-cells of the pancreatic islets. In Cd+NS-treated rats, increased staining of insulin and preservation of islet cells were apparent. It is concluded that NS treatment might decrease the Cd-treated disturbances on heart rate, some hematological values, and pancreatic β-cell.


Hemodialysis International | 2011

Oxidative DNA damage correlates with carotid artery atherosclerosis in hemodialysis patients.

Elif Ari; Yuksel Kaya; Halit Demir; Aysegul Cebi; Hamit Hakan Alp; Ebubekir Bakan; Dolunay Odabasi; Sıddık Keskin

Oxidative stress is accepted as a nonclassical cardiovascular risk factor in chronic renal failure patients. The aim of this study was to evaluate the relation between oxidative DNA damage (8‐hydroxy‐2′‐deoxyguanosine/deoxyguanosine [8‐OHdG/dG] ratio), oxidative stress biomarkers, antioxidant enzymes, and carotid artery intima‐media thickness (CIMT) in hemodialysis (HD) patients. Forty chronic HD patients without known atherosclerotic disease and 48 age‐ and sex‐matched healthy individuals were included in the study. Plasma malondialdehyde (MDA) levels and 8‐OHdG/dG ratio were determined as oxidative stress markers. Superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities were measured as antioxidants. CIMT was assessed by carotid artery ultrasonography. 8‐OHdG/dG ratios and MDA levels were higher; SOD and GPx activities were lower in HD patients compared to controls. HD patients had significantly higher CIMT compared to controls (0.61 ± 0.08 vs. 0.42 ± 0.05, p < 0.001). There was a significant positive correlation between CIMT and 8‐OHdG/dG ratio (r = 0.57, p < 0.01) and MDA levels (r = 0.41, p < 0.01), while there was a significant negative correlation between CIMT and SOD (r = −0.47, p < 0.01) and GPx levels (r = −0.62, p < 0.01). It is firstly demonstrated that CIMT is positively correlated with oxidative DNA damage in HD patients without known atherosclerotic disease.


Human & Experimental Toxicology | 2012

Serum trace elements and heavy metals in polycystic ovary syndrome

Zehra Kurdoglu; Mertihan Kurdoglu; Halit Demir; Hanim Guler Sahin

Objective: We aimed to investigate the serum levels of essential trace elements copper (Cu), zinc (Zn), manganese (Mn), magnesium (Mg) and heavy metals cadmium (Cd), cobalt (Co) and lead (Pb) in the patients with polycystic ovary syndrome (PCOS). Methods: A total of 65 (35 patients with PCOS and 30 healthy controls) women were included in the study. Serum Cu, Zn, Mn, Pb, Mg, Co and Cd levels were analyzed using atomic absorption spectrophotometric method. Results: Serum Cu and Zn levels were significantly higher, but Mn and Pb levels were lower in patients with PCOS compared with the healthy participants (p < 0.01). There was no difference between patients with PCOS and the controls with respect to the serum levels of Mg, Co and Cd. Conclusions: This is the first study investigating serum Cu, Zn, Mn, Pb, Co, Mg and Cd levels in the patients with PCOS. The serum levels of trace elements and heavy metals might change in patients with PCOS. The findings in this study should be investigated with further trials in order to obtain new insights into PCOS.


Asian Pacific Journal of Cancer Prevention | 2013

Levels of serum trace elements in renal cell carcinoma cases.

Necip Pirincci; Ilhan Gecit; Mustafa Güneş; Mehmet Kaba; Serhat Tanik; Mehmet Bilgehan Yuksel; Harun Arslan; Halit Demir

Trace elements which are essential components of biological structures may also be toxic when present at levels above the amounts required for biological function. In our study, trace element levels were measured with furnace atomic absorption spectrophotometry in 33 newly diagnosed renal cell carcinoma cases (preoperative) and 32 healthy controls. When compared with the control group, it was found that the levels of cadmium (Cd), lead (Pb) were higher and the levels of zinc (Zn), iron (Fe) and manganese (Mn) were lower in the patient group. These changes may be important in the formation of renal cell carcinoma, a question which should be explored with postoperative comparative studies.


Clinics | 2012

Serum adenosine deaminase, catalase and carbonic anhydrase activities in patients with bladder cancer

Necip Pirincci; Ilhan Gecit; Mustafa Güneş; Mehmet Bilgehan Yuksel; Mehmet Kaba; Serhat Tanik; Halit Demir; Mehmet Aslan

OBJECTIVES: The relationship between adenosine deaminase and various cancers has been investigated in several studies. However, serum adenosine deaminase activity and carbonic anhydrase and catalase activities in patients with bladder cancer have not previously been reported. Therefore, the aim of this study was to measure serum adenosine deaminase, carbonic anhydrase and catalase activities in patients with bladder cancer. MATERIALS AND METHODS: Forty patients with bladder cancer and 30 healthy controls were enrolled in the study. Serum adenosine deaminase, carbonic anhydrase and catalase activities were measured spectrophotometrically. RESULTS: Serum adenosine deaminase, carbonic anhydrase and catalase activities were significantly higher in patients with bladder cancer than controls (all significant, p<0.001). CONCLUSIONS: These markers might be a potentially important finding as an additional diagnostic biochemical tool for bladder cancer.


Redox Report | 2014

Serum paraoxonase-1 enzyme activities and oxidative stress levels in patients with esophageal squamous cell carcinoma

Abidin Sehitogullari; Mehmet Aslan; Fuat Sayır; Ali Kahraman; Halit Demir

Abstract Objectives Oxidative stress is well recognized to play a role in the pathogenesis of many diseases, including cancers. Paraoxonase-1 (PON1) is implicated in the elimination of carcinogenic lipid-soluble radicals produced by lipid peroxidation. Reports on PON1 activities in patients with cancer are conflicting. The aim of this study was to investigate serum antioxidant enzyme activities and oxidative stress levels in patients with esophageal squamous cell carcinoma (ESCC). Patients and methods Thirty-two patients with ESCC and 33 healthy controls were enrolled. Serum malondialdehyde (MDA) levels and superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), glutathione reductase (GR), paraoxonase, and arylesterase activities were measured spectrophotometrically. Results Serum paraoxonase, arylesterase, SOD, activities, GSH-Px, and GR activities were significantly lower in patients with ESCC than in controls (all, P < 0.05), whereas serum MDA levels were significantly higher (P < 0.05). Serum MDA levels were significantly correlated with paraoxonase (r = −0.572, P < 0.001) and arylesterase activities (r = −0.597, P < 0.001) in patients with ESCC. Conclusions This study indicated that ESCC is associated with increased oxidative stress and decreased antioxidant enzyme activities. Decreased serum PON1 enzyme activities may play a role in the progression and/or development of ESCC. Further studies are required to clarify these results.


Toxicology and Industrial Health | 2016

Serum prolidase activity, oxidative stress, and antioxidant enzyme levels in patients with renal cell carcinoma

Necip Pirincci; Mehmet Kaba; Ilhan Gecit; Mustafa Güneş; Mehmet Bilgehan Yuksel; Serhat Tanik; Ayşe Arslan; Halit Demir

Objectives: Prolidase is a member of the matrix metalloproteinase family. It plays a vital role in collagen turnover, matrix remodeling, and cell growth. Reactive oxygen species (ROS) have been implicated in the pathogenesis of various diseases, including cancers. Oxidative stress can cause tumor angiogenesis and may be carcinogenic. However, the relationship between antioxidant capacity and various cancers has been researched in several clinical trials. In our study, we aimed to identify serum prolidase activity, oxidative stress, and antioxidant enzyme levels in patients with renal tumors and to evaluate their relationships with each other. Materials and Methods: A total of 37 male patients with renal cell cancer and with a mean age of 56.28 ± 3.1 were included in the study. The control group comprising 36 male patients (mean age 56.31 ± 2.9) was randomly selected among the volunteers. Serum samples for measurement of superoxide dismutase (SOD), glutathione peroxidase (GSHPx), glutathione-S-transferase (GST), malondialdehyde (MDA), glutathione (GSH), and prolidase levels were kept at −20°C until they were used. Results: Serum prolidase activity and MDA levels were significantly higher in renal cancer patients than in controls (all, p < 0.05), while SOD, GSHPx, and GST levels were significantly lower (p < 0.05). Conclusion: Our results indicate that increased prolidase seems to be related to increased oxidative stress along with decreased antioxidant levels in renal cancer.


Toxicology and Industrial Health | 2013

Effect of levosimendan injection on oxidative stress of rat myocardium.

Halil Basel; Servet Kavak; Halit Demir; Ismail Meral; Hasan Ekim; Havva Bektas

This experiment was designed to investigate the effect of levosimendan injection on lipid peroxidation product malondialdehyde (MDA) and antioxidant glutathione (GSH) levels, and activities of antioxidant enzymes in myocardium of rats. Twenty male Wistar-albino rats were divided randomly into 2 study groups, each consisting of 10 rats. The animals in the first group were not treated with drug and served as control. It was found that the MDA and GSH levels decreased in levosimendan injected group. Superoxide dismutase, glutathione peroxidase, catalase and carbonic anhydrase enzyme activities were lower in levosimendan injected group than controls. It was concluded that lower tissue free radical level caused by levosimendan injection led to a lower antioxidant enzymes synthesis in the body and a decrease in the antioxidant enzyme activity and free radical scavenger level in myocardium of rat.

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Ilhan Gecit

Yüzüncü Yıl University

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Mehmet Aslan

Yüzüncü Yıl University

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Canan Demir

Yüzüncü Yıl University

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Necip Pirincci

Yüzüncü Yıl University

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Ismail Meral

Yüzüncü Yıl University

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Mustafa Güneş

Yüzüncü Yıl University

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Servet Kavak

Yüzüncü Yıl University

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Yüksel Kaya

Yüzüncü Yıl University

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Fuat Sayır

Yüzüncü Yıl University

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