Hikmet Kocak

Publications (12)21.12 Total impact

• Article: Urinary nerve growth factor in children with overactive bladder: A promising, noninvasive and objective biomarker.

  Tayfun Oktar, Taner Kocak, Yıldız Oner-Iyidogan, Selcuk Erdem, Muhammed Seyithanoglu, Orhan Ziylan, Hikmet Kocak
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  ABSTRACT: OBJECTIVE: This prospective study was designed to determine urinary nerve growth factor (NGF) levels in children with overactive bladder (OAB), and to evaluate whether this factor can be used as a biomarker for diagnosis and monitoring treatment outcome. PATIENTS AND METHODS: Urinary NGF levels were determined in 40 children with OAB and in a control group of 20 children with no urinary symptoms. Urine samples were collected from the patients prior to and at 3 and 6 months after the beginning of treatment. The total NGF levels (pg/mL) were further normalized to the concentration of urinary creatinine (NGF/Cr level). RESULTS: Overall, both NGF and NGF/Cr levels were significantly higher at the beginning of the study. Mean NGF levels were 30.75 ± 8.35 and 9.75 ± 2.11 pg/ml (p = 0.023) and mean NGF/Cr levels were 0.53 ± 0.14 and 0.16 ± 0.04 (p = 0.022) in patients and controls, respectively. After 6 months of therapy, the NGF/Cr level was significantly reduced to almost control levels (0.16 ± 0.02, p = 0.047). CONCLUSION: NGF and NGF/Cr levels were significantly higher in children with OAB than controls at initial evaluation. Furthermore, the NGF/Cr level was significantly reduced following 6 months of therapy. NGF and NGF/Cr levels show promise as reliable biomarkers for OAB diagnosis and to monitor therapy in the pediatric age group.
  Journal of pediatric urology 07/2012; · 1.38 Impact Factor
• Article: Serum asymmetric dimethylarginine and nitric oxide levels in obese postmenopausal women.

  Hikmet Kocak, Yıldız Oner-Iyidogan, Figen Gurdol, Pernur Oner, Deniz Esin
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  ABSTRACT: It has been reported that estrogen deficiency after menopause might cause a decrement in nitric oxide (NO) bioavailability by increasing the level of asymmetric dimethylarginine (ADMA), a major endogenous nitric oxide synthase inhibitor, thus leading to abnormalities in endothelial function. Because NO plays an important role on feeding behavior, ADMA may be involved in the pathogenesis of obesity, too. This cross-sectional study aimed to evaluate the relations of ADMA and NO with the obesity-linked peptides, such as ghrelin, leptin, and adiponectin in postmenopausal women free of hormone replacement therapy. Adiponectin, ghrelin, leptin, ADMA, and NO(x) (total nitrite/nitrate) were measured in 22 obese (BMI: 30-47 kg/m(2)) and 19 normal weight (BMI: 21.5-26 kg/m(2)) postmenopausal women.Anthropometric measurements (height, weight, BMI, waist, and hip circumferences) were recorded. Statistics were made by the Mann-Whitney U-test. Ghrelin and adiponectin levels were significantly lower (P<0.001), whereas ADMA and leptin levels were higher in obese women than in normal weight controls (P<0.01 and 0.001, respectively). BMI was correlated negatively with adiponectin and ghrelin and positively with ADMA and leptin levels. No correlation existed between ADMA and NO. Estrogen deficiency alone may not cause an increase in ADMA levels unless the women are prone to disturbances in energy homeostasis. In spite of the high ADMA levels, the unaltered NO levels in plasma may be owing to ongoing inflammatory conditions.
  Journal of Clinical Laboratory Analysis 01/2011; 25(3):174-8. · 1.38 Impact Factor
• Article: Appetite-regulating hormones in chronic kidney disease patients.

  Yildiz Oner-Iyidogan, Figen Gurdol, Hikmet Kocak, Pernur Oner, Pinar Cetinalp-Demircan, Yasar Caliskan, Taner Kocak, Aydin Turkmen
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  ABSTRACT: Inflammation and loss of appetite is the most common problem in patients with chronic kidney disease (CKD). This comparative cross-sectional study aimed to characterize the changes in circulating levels of ghrelin, obestatin, leptin, all of which have an effect on food intake, and proinflammatory cytokines interleukin (IL)-6 and tumor necrosis factor-alpha (TNF-α) in patients with CKD who were undergoing different treatments. Study participants included 36 patients who had undergone hemodialysis (body mass index [BMI]: 22.3 ± 4.17 kg/m(2)); 41 who had undergone peritoneal dialysis (BMI: 23.5 ± 3.10 kg/m(2)), 30 with early stage CKD (BMI: 24.4 ± 3.32 kg/m(2)), and 31 healthy subjects (24.3 ± 2.14 kg/m(2)). The patients with CKD were kept under a standard diet with restricted salt, potassium, and protein intake. Levels of leptin, acylated ghrelin, obestatin, TNF-α, and IL-6 were measured by commercially available enzyme-linked immunosorbent assay kits. Total nitrite/nitrate was analyzed using colorimetric assay kit. Significantly high leptin levels, accompanied by low acylated ghrelin levels, were observed in patients with CKD. Maintenance dialysis did not affect these levels. TNF-α and IL-6 levels were significantly higher in CKD patients than in healthy subjects, the highest being in dialysis patients. Obestatin levels were relatively low in patients who had undergone hemodialysis. Low acyl-ghrelin levels, accompanied with high levels of TNF-α and IL-6 may be involved in the loss of appetite and poor nutritional status in CKD patients.
  Journal of Renal Nutrition 12/2010; 21(4):316-21. · 1.57 Impact Factor
• Article: Dimethylarginines and inflammation markers in patients with chronic kidney disease undergoing dialysis.

  Yildiz Oner-Iyidogan, Pernur Oner, Hikmet Kocak, Figen Gurdol, Seldag Bekpinar, Yesim Unlucerci, Yasar Caliskan, Pinar Cetinalp-Demircan, Taner Kocak, Aydin Turkmen
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  ABSTRACT: The aim of this study was to investigate the pro-oxidant and proinflammatory biomarkers and their relationship with dimethylarginines (DMAs) in patients at various stages of chronic kidney disease (CKD). We studied 114 CKD patients, 36 were hemodialyzed, 41 peritoneal dialyzed and 37 nondialyzed (early stage) CKD patients. The control group consisted of 31 healthy subjects. Plasma levels of asymmetric dimethylarginine (ADMA), symmetric dimethylarginine (SDMA), L-arginine, nitric oxide (NO) and proinflammatory cytokines (TNF-alpha and IL-6) were determined, and their relationships with the degree of disease were evaluated. Both DMAs were at high levels in all CKD patients, whereas arginine concentrations were low in patients undergoing dialysis. Elevated TNF-alpha and IL-6 in CKD patients were indicative of ongoing chronic inflammatory state. A significant positive correlation between SDMA and creatinine suggests that plasma SDMA level may be an index for renal function.
  Clinical and Experimental Medicine 03/2009; 9(3):235-41. · 1.58 Impact Factor
• Article: The impact of intraoperative transit time flow measurement on the results of on-pump coronary surgery.

  Necip Becit, Bilgehan Erkut, Munacettin Ceviz, Yahya Unlu, Abdurrahim Colak, Hikmet Kocak
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  ABSTRACT: The purpose of this study is to evaluate the effect of detection of graft dysfunction by intraoperative transit time flow measurement (TTFM) on the surgical results of on-pump coronary artery bypass grafting. Two hundred patients undergoing on-pump isolate coronary artery bypass grafting via median sternotomy performed by the same surgical team were included into the study. TTFM was routinely performed for assessment of graft patency during operation after a transit time flow meter became available in our center in February 2006. The last 100 consecutive patients before this date formed the control group (Group A), and the first 100 consecutive patients after this date formed the study group (Group B). Interpretation of the values obtained using the TTFM in Group B patients has allowed us to reach a decision whether or not to revise a graft. Preoperative and postoperative variables of the two groups were compared. The clinical features of control and study groups were comparable. We assessed patency of 303 grafts using TTFM. Revision was required for nine grafts in nine patients based on unsatisfactory TTFM findings. Incidences of overall mortality (p<0.05), peri- or postoperative myocardial infarction (p<0.05) and intraaortic balloon pump insertion (p<0.05) were significantly lower in Group B than Group A. We believe that TTFM seems to be a crucial tool for deciding if a graft is well-functioning or not, and it allows for improvement of graft failure during operation. Our results suggest that detection of graft dysfunction intraoperatively by TTFM improves the surgical outcome.
  European Journal of Cardio-Thoracic Surgery 08/2007; 32(2):313-8. · 2.55 Impact Factor
• Article: Ventricular septal rupture and mitral regurgitation caused by trauma.

  Fuat Gündoğdu, Yekta Gurlertop, Sakir Arslan, Hikmet Kocak, Sule Karakelleoglu, Sebahattin Atesal
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  ABSTRACT: We present a young patient with traumatic septal rupture following traffic accident in whom transthoracic echocardiography allowed comprehensive noninvasive assessment of location and size of the septal defect and structure atrioventricular valve apparatus.
  Echocardiography 03/2007; 24(2):174-5. · 1.24 Impact Factor
• Article: The effect of surgical treatment for secundum atrial septal defect in patients more than 30 years old.

  Bilgehan Erkut, Necip Becit, Yahya Unlu, Munacettin Ceviz, Cevdet Ugur Kocogullari, Azman Ates, Bekir Sami Karapolat, Mehmet Ali Kaygin, Hikmet Kocak
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  ABSTRACT: We prospectively examined whether surgical treatment of secundum atrial septal defects in patients 30 years old improves their early- and mid-term clinical outcomes. Our clinical experience is reviewed to assess the importance of surgical management in elderly patients with atrial septal defect. We analyzed 41 patients older than 30 years of age who underwent surgical correction of a secundum atrial septal defect. To evaluate the effects of surgical treatment, we compared functional capacity, diuretic administration, rhythm status, and echocardiographic parameters of all patients before and after the operation. The median follow-up period was 4.2 years (range, 6 months-7 years). There were no operative deaths. Functional class in most of the patients improved after operation. Two patients reverted to normal sinus rhythm after the operation. There was only one new atrial fibrilation among patients in the postoperative term. Right atrial and right ventricular dimensions and pulmonary artery pressures were significantly decreased, and ejection fractions were significantly increased after the operation. The need for diuretic treatment was decreased after surgical repair. No residual intracardiac shunts were identified during follow-up. There were no cerebrovascular thromboembolic accidents in the early postoperative period. Surgical closure of atrial septal defects in patients over 30 years old can improve their clinical status and prevent right ventricular dilatation and insufficiency. The operation must be performed as soon as possible, even if the symptoms or the hemodynamic impact seem to be minimal.
  Heart Surgery Forum 02/2007; 10(5):E376-80. · 0.63 Impact Factor
• Article: Ventricular Septal Rupture and Mitral Regurgitation Caused by Trauma

  Fuat Gündoğdu M.D, Yekta Gurlertop, Sakir Arslan, Hikmet Kocak, Sule Karakelleoglu, Sebahattin Atesal
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  ABSTRACT: We present a young patient with traumatic septal rupture following traffic accident in whom transthoracic echocardiography allowed comprehensive noninvasive assessment of location and size of the septal defect and structure atrioventricular valve apparatus.
  Echocardiography 01/2007; 24(2):174 - 175. · 1.24 Impact Factor
• Source

  Available from: PubMed Central

  Article: Effects of ascorbic Acid, alpha-tocopherol and allopurinol on ischemia-reperfusion injury in rabbit skeletal muscle: an experimental study.

  Bilgehan Erkut, Ahmet Özyazıcıoğlu, Bekir Sami Karapolat, Cevdet Uğur Koçoğulları, Sait Keles, Azman Ateş, Cemal Gundogdu, Hikmet Kocak
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  ABSTRACT: Ischemia reperfusion injury to skeletal muscle, following an acute arterial occlusion is important cause of morbidity and mortality. The aim of the present study was to determine and evaluate the effects of ascorbic acide, alpha-tocopherol and allopurinol on ischemia reperfusion injury in rabbit skeletal muscle. Forty-eight New Zealand white rabbits, all male, weighing between 2.5 to 3.0 (mean 2.8) kg, were used in the study. They were separated into four groups. Group I was the control group without any drugs. The other groups were treatment groups (groups II, III, and IV). Group II rabbits administrated 50 mg/kg ascorbic acide and 100 mg/kg alpha-tocopherol 3 days prior to ischemia, group III rabbits received 50 mg/kg allopurinol 2 days prior to ischemia, and group IV rabbits were administrated both 50 mg/kg ascorbic acide, 100 mg/kg alpha-tocopherol 3 days prior to ischemia and 50 mg/kg allopurinol 2 days prior to ischemia. Two hours ischemia and 2 hours reperfusion were underwent to the treatment groups. At the end of the reperfusion periods, muscle samples were taken from rectus femoris muscle for determination of superoxide dismutase, catalase and glutathione peroxidase activities as antioxidant enzymes, and malondialdehyde as an indicator of lipid peroxidation and xanthine oxidase levels as source hydroxyl radical. Besides, histopathological changes (edema, inflammation, ring formation and splitting formation) were evaluated in the muscle specimens. In the treatment groups; superoxide dismutase (U/mgprotein), catalase (U/mgprotein), and glutathione peroxidase (U/mgprotein) levels increased, malondialdehyde (nmol/mgprotein) and xanthine oksidase (mU/mgprotein) levels decreased compared to control I ( p < 0.05). Increase of superoxide dismutase, catalase, and glutathione peroxidase levels were the highest and decrease of malondialdehyde and xanthine oxidase levels were the highest in group IV compared to groups II and III, but no significant as statistically. Also amount of cellular injury in group II, III, and IV were lower than group I. Antioxidant medication may help lowering ischemia reperfusion injury. In our study, all drug medications are shown to be able to have an effective role for preventing ischemia reperfusion injury. Moreover, ascorbic acide + alpha-tocopherol + allopurinol group (group IV) may have a beneficial effect to decrease the local and systemic damage due to ischemia-reperfusion injury.
  Drug Target Insights 01/2007; 2:249-58.
• Source

  Available from: Cevdet Kocogullari

  Article: Primary and secondary patency rates and complications of upper extremity arteriovenous fistulae created for hemodialysis.

  Azman Ates, Ahmet Ozyazicioglu, Ibrahim Yekeler, Münacettin Ceviz, Bilgehan Erkut, Sami Karapolat, Cevdet Ugur Koçogullari, Hikmet Kocak
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  ABSTRACT: The types of fistulae used and their complication rates are important for the hemodialysis patients. We aimed to compare retrospectively the primary and secondary patency rates and complications of upper extremity arteriovenous fistulae. Between 1984 and 2005, a total of 1,233 upper extremity arteriovenous fistulae were created in 920 patients. The mean age was 42 +/- 21 years. The fistulae were divided into the 3 groups; 588 radiocephalic, 205 brachiocephalic, and 127 were created by polytetrafluoroethylene graft. The fistulae types were evaluated with regard to their primary-secondary patency rates and complications. There was a significant difference with regard to development of thrombosis in radiocephalic group compared to other two groups, respectively, p = 0.0122, p = 0.0091. In brachiocephalic fistulae group, edema and steal phenomenon were statistically significant (p < 0.0001). The aneurysm formation was statistically significant in polytetrafluoroethylene fistulae graft group (p < 0.0001). During 6 months, 2 and 5 years period, while primary patency rate was higher in three fistulae types, in radiocephalic fistulae both primary and secondary fistulae patency rates were lower (p < 0.05). To create successful arteriovenous fistulae with long-term patency, appropriate veins of patients should be carefully preserved; thus initially a distal site should be preferred, and in case of failure the next fistulae should be created proximally. In case of failure of forearm fistulae, primary fistulae with autogenous veins should be tried at the upper arm first, and if this also fails, fistulae formation with synthetic grafts should be considered.
  The Tohoku Journal of Experimental Medicine 10/2006; 210(2):91-7. · 1.24 Impact Factor
• Article: One of the most frequent vascular diseases in northeastern of Turkey: Thromboangiitis obliterans or Buerger's disease (experience with 344 cases).

  Azman Ates, Ibrahim Yekeler, Münacettin Ceviz, Bilgehan Erkut, Mustafa Pac, Ahmet Basoglu, Hikmet Kocak
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  ABSTRACT: This is a retrospective clinical study on adult patients treated surgically for Buerger's disease in our region. In our clinic, 344 patients with Buerger's disease were surgically treated between 1980 and 2004. The major complaints included foot coldness in 312 (90.6%) patients, color changes in 290 (84.3%), rest pain in 160 (46.5%), claudication in 166 (48.2%) and necrotic ulcers in 185 (53.1%). Lumbar sympathectomy was made in 278 (80.2%) patients, thoracic sympathectomy in 7 (2.2%), thoracic and lumbar sympathectomy in 12 (3.6%), lumbar sympathectomy and femoropopliteal or femorotibial bypass in 30 (9%), and femoropopliteal or femorotibial bypass in 17 (5%). Color changes were improved in 230 (79.3%) patients, food coldness were decreased in 288 (92.3%) and rest pains were improved in 43 (26.8%). Intermittent claudications decreased in 132 of 166 patients. Necrotic ulcers healed in 30 of 185 patients. Amputation was made totally in 155 (53%) patients in 10 years. As a nonatherosclerotic, segmental, inflammatory disease, Buerger's disease is casually related to tobacco use. The main goal is to discontinue the use of tobacco. Sympathectomy may be helpful in healing the ulcers and decreasing the symptoms. Vascular reconstruction is rarely possible for patients with Buerger's disease due to segmental involvement and distal nature of the disease.
  International Journal of Cardiology 08/2006; 111(1):147-53. · 7.08 Impact Factor
• Article: Massive pulmonary embolism complicated by a patent foramen ovale with straddling thrombus: report of a case.

  Bilgehan Erkut, Hikmet Kocak, Necip Becit, Huseyin Senocak
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  ABSTRACT: We report a case of massive right pulmonary embolism with a patent foramen ovale and straddling thrombus, occurring a few days after cesarean section in a 31-year-old woman. Preoperatively, a mass was seen echocardiographically in four cardiac cavities. We performed emergency surgery because of the patient's acute hemodynamic deterioration. Intraoperatively, we found a thrombus entrapped in the patent foramen ovale. Most of the thrombus was floating in the right atrium and a long end was found in the left atrium, in addition to the pulmonary emboli. We removed the thrombus, closed the patent foramen ovale by direct suturing, and performed pulmonary embolectomy. Histological examination confirmed thrombi. Doppler examination of the venous system did not reveal any possible source of the thrombus. The patient is now well and free from recurrence of embolic disease 1 year after surgery. We review the literature on this relatively unusual thromboembolic disease.
  Surgery Today 02/2006; 36(6):528-33. · 1.22 Impact Factor