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Featured researches published by Köksal Öner.


American Journal of Nephrology | 2005

Assessment of oxidative stress in the early posttransplant period: comparison of cyclosporine A and tacrolimus-based regimens.

Abdulgaffar Vural; Mahmut Ilker Yilmaz; Kayser Caglar; Ahmet Aydin; Alper Sonmez; Tayfun Eyileten; Cengizhan Acikel; Bülent Güleç; Orhan Kozak; Köksal Öner

Background: Oxidative stress is one of the leading causes of cardiovascular morbidity and mortality in chronic kidney disease. Although it is clear that many metabolic abnormalities improve, the effects of kidney transplantation on oxidative state are obscure. Methods: Twenty-three kidney transplant patients were included in the study. Eleven patients (mean age 27.9± 9.1 years) were treated with cyclosporine A (CsA) whereas 12 patients (mean age 22.4 ± 3.4 years) were treated with tacrolimus. Twenty-three healthy subjects served as controls. None of the patients or controls suffered from diabetes mellitus or an acute infection at the time of the study. Plasma malondialdehyde (MDA), plasma selenium (Se), erythrocyte glutathione peroxidase (GSH-Px), erythrocyte superoxide dismutase (SOD), erythrocyte Zn (EZn), and erythrocyte Cu (ECu) levels were studied before and in the 1st,3rd, 7th, 14th and 28th days after the transplantation. Results: The GSH-Px, SOD, ECu, EZn and selenium levels were lower and MDA levels were higher in patients than controls before transplantation (p < 0.001 for all). MDA levels decreased and SOD, GSH-Px, ECu, EZn levels increased in parallel to the decrement of serum creatinine levels following the renal transplantation. No difference was found among the patients regarding the treatment regime. Conclusion: The study data suggest that the improvement in oxidative state parameters begins at the first day of renal transplantation and continues at the 28th posttransplant day in living donor transplantations.


Transplantation | 2007

Endothelial dysfunction and fetuin A levels before and after kidney transplantation

Kayser Caglar; Mahmut Ilker Yilmaz; Mutlu Saglam; Erdinc Cakir; Selim Kilic; Tayfun Eyileten; Alper Sonmez; Yusuf Oguz; Köksal Öner; Fatih Ors; Abdulgaffar Vural; Mujdat Yenicesu

Background. Endothelial dysfunction (ED) has a major role in the cardiovascular outcome of patients with chronic kidney disease (CKD). The aim of this study was to investigate the relation between fetuin A levels and ED in kidney transplant recipients. Methods. Forty-two living donor kidney transplant recipients, 21 (11 male) on cyclosporine A and 21 (10 male) on tacrolimus-based regimes, were studied. Forty-two (21 male) healthy subjects were enrolled as controls. Fetuin A, highly sensitive C-reactive protein (hsCRP) levels, brachial artery endothelium-dependent vasodilatation (FMD), nitroglycerine mediated dilatation (NMD), and carotid intima-media thickness (CIMT) were measured before transplantation and on the 30th and 90th days posttransplant. Results. Pretransplantation serum fetuin A concentrations and FMD values of patients were significantly lower than those of the controls (P<0.001 for both). These were significantly increased in the 30th and 90th days posttransplantation There was a significant positive correlation between Fetuin A and FMD levels both before and after kidney transplantation (r=0.534, r=0.576; respectively, P<0.001 for both). Carotid intima-media thickness and hsCRP levels decreased after transplantation (P<0.001 for all). According to the regression analysis, fetuin A, intact parathyroid hormone, and hsCRP levels were the independent determinants of FMD. Conclusion. The results of the present study suggest that low serum fetuin A levels in CKD may contribute to impaired endothelial functions in CKD. Future studies should clarify the role of fetuin A levels in cardiovascular outcomes of CKD.


Anz Journal of Surgery | 2006

Lower extremity venous changes in pneumoperitoneum during laparoscopic surgery.

Bülent Güleç; Köksal Öner; Cengizhan Yigitler; Murat Kocaoglu; Yüksel Aydin; Mutlu Saglam

Background:  The effect of pneumoperitoneum on veins of the lower limbs related to the intra‐abdominal working pressures during laparoscopic cholecystectomy has not been thoroughly investigated. We tested the hypothesis that working pressures do not affect the venous haemodynamics in the lower limbs.


Transplantation Proceedings | 2008

Ischemia-Reperfusion Injury in the Liver During Renal Transplantation: Does Perfusion Solution Play Any Role?

Bülent Güleç; K. Coskun; Cengizhan Yigitler; Taner Yigit; A. Aydin; Köksal Öner

The effect of ischemia-reperfusion (I/R) injury within a transplanted kidney has not been reported on the liver as a remote organ. One hypothesis is that there is no difference between kidney perfusion solutions regarding antioxidants in liver after an I/R injury. We used four pigs with Ringers lactate (RL); four with university of Wisconsin (UW); and two in a control (C) group. A liver parenchymal biopsy was obtained before renal artery/vein solution clamping for 20 minutes. Either RL or UW solutions were infused through arterial cannulas for 20 minutes as previously described elsewhere. For the sham group, we used 0.9% NaCl. After reperfusion for 20 minutes, we obtained a second liver parenchymal biopsy. Measurements of superoxide dismutase (SOD), glutathione peroxidase (GP-x), and malondialdehyde (MDA) levels were compared using paired student t tests within groups and analysis of variance between groups. The results were expressed as mean values +/- SEM with P < .05 accepted as significant. Although GP-x, SOD, and MDA decreased after ischemia-perfusion-reperfusion injuries in all groups, except MDA in UW and SOD, and MDA in C groups; only the MDA for C was significant (P = .04) Comparing the groups, GP-x (P = .01) and MDA (P = .003) levels after ischemia-perfusion-reperfusion were significant while changes in SOD levels did not show any difference (P > .05). In a kidney transplantation model, the liver was affected during the ischemia-perfusion-reperfusion process as evidenced by antioxidant enzymes. The pathophysiology and clinical importance of this phenomenon requires further study. Comparing the perfusion solutions, no difference was found between RL and UW regarding their effects to decrease renal I/R injury on the liver in pigs.


Acta Chirurgica Belgica | 2005

Do we need to use subcutaneous suture for pilonidal sinus treated with excision and simple primary closure

Taner Yigit; Cengizhan Yigitler; Bülent Güleç; A. Ihsan Uzar; Tahir Özer; Köksal Öner

Abstract Objective : Pilonidal sinus (PS) is a chronic intermittent disease. There are numerous surgical treatment procedures that have been previously reported, yet none have been proved to be ideal. The main issues concerning the surgical treatment of PS are simplicity and cost-effectiveness. This study is designed to research the possibility of decreasing operation costs in the excision and simple primary closure technique of PS by omitting subcutaneous suture usage. Materials and methods : 152 male patients with chronic PS were included in the study. All patients were treated with excision and simple primary closure technique and randomized into two groups. Group-I (n = 74) received subcutaneous closure with 2/0 polyglactin sutures, but Group-II (n = 78) did not. Wound edges were re-approximated by using deep interrupted matress 0 no polypropylene sutures in both groups. Results : In Group-I; overall 7 (9.5%) early complications were noted; 2(2.7%) wounds broke down and 5 (6.7%) experienced superficial wound infections. Any late wound complications were noted. A total of 98 polypropylene and 104 polyglactin sutures were used. In Group-II; overall 5 (6.4%) early wound complications were noted; 3 (3.8%) had wound dehiscence and 2 (2.6%) developed superficial wound infections. Also, 1 (1.3%) late wound complication (wound dehiscence) occurred. Overall 104 polypropylene sutures were used. Conclusion : Excision and simple primary closure is a simple and cost effective surgical procedure in the treatment of PS. Omitting the use of subcutaneous sutures makes the procedure simpler and decreases the operation costs.


Journal of Trauma-injury Infection and Critical Care | 2003

Increased damage from rifle wounds of the chest caused by bullets striking commonly carried military equipment

Mehmet Dakak; Ali İhsan Uzar; Mutlu Saglam; Tahir Özer; Sedat Gürkök; Kunter Balkanli; Köksal Öner; Dervip Sen

BACKGROUND The purpose of this study was to investigate the fragmentation effect of the bullet that passes through the radio or ammunition magazine, which are essential pieces of equipment for a soldier, in thoracic gunshot injuries. METHODS Twelve adult pigs were used. The pigs were separated into three groups (each group contained four pigs). The first group was shot without any obstacle between muzzle and subject. The second group was shot through a cartridge magazine placed in front of the subjects thoracic cage. The third group was shot with a radio in front of the subjects thoracic cage. RESULTS It was observed that there was a large bullet entrance and fragmentation in the pigs that were shot with a radio or magazine placed over them, and there was no fragmentation in those that were shot without any obstacle. CONCLUSION Metal equipment that soldiers carry causes bullet fragmentation. Fragmented bullets may cause excessive tissue disruption of intrathoracic vital organs.


European Journal of Radiology Extra | 2003

Multiple myeloma of the breast: mammographic, ultrasonographic and magnetic resonance imaging features

Murat Kocaoglu; İbrahim Somuncu; Nail Bulakbasi; Cem Tayfun; Mustafa Tasar; Ömer Günhan; Köksal Öner

Abstract Although the incidence of extramedullary plasmacytoma of the breast is quite unusual, the exact recognition of this clinical problem is important in order to prevent unnecessary surgery. We present mammographic, sonographic and magnetic resonance imaging (MRI) characteristics of myeloma infiltration of the breast in a patient who had been treated for skeletal multiple myeloma.


World Journal of Surgery | 2001

Hypertonic Saline in Hydatid Disease

Cuneyt Kayaalp; Müjdat Balkan; Cenk Aydin; Taner Ozgurtas; Mehmet Tanyuksel; Vedat Kirimlioglu; Musa Akoglu; Köksal Öner; Mesut Pekcan


Radiation Medicine | 1997

Protective Effect of Vitamin A on Acute Radiation Injury in the Small Intestine

Murat Beyzadeoglu; Müjdat Balkan; Murat Demiriz; Hasan Tibet; Bahar Dirican; Köksal Öner; Yücel Pak


Transplantation Proceedings | 2006

Effects of perfusion solutions on kidney ischemia-reperfusion injury in pigs

Bülent Güleç; K. Coskun; Köksal Öner; A. Aydin; Cengizhan Yigitler; Orhan Kozak; Ali İhsan Uzar; I. Arslan

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Taner Yigit

Military Medical Academy

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Müjdat Balkan

Military Medical Academy

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Murat Durusu

Military Medical Academy

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Mehmet Dakak

Military Medical Academy

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Tahir Özer

Military Medical Academy

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Mutlu Saglam

Military Medical Academy

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