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Featured researches published by Eyüp Hazan.


Cancer Letters | 1997

Determination of glutathione, glutathione reductase, glutathione peroxidase and glutathione S-transferase levels in human lung cancer tissues

Nurten Saydam; A. Kirb; Ö. Demir; Eyüp Hazan; Öztekin Oto; O. Saydam; Gül Güner

This study was performed to elucidate the lung glutathione-related defense potential in tumoral tissues. Reduced (GSH) and oxidized (GSSG) glutathione, glutathione reductase (GR), selenium-dependent (SeGPx) and total glutathione peroxidase (tGPx), and glutathione S-transferase (GST) activities in 38 tumoral lung tissues and 17 normal lung tissues were determined to obtain a comprehensive profile of the lung glutathione and glutathione-related enzymes in cancer. The enzyme levels in tumoral tissues (n = 38) were found to be significantly higher (P < 0.05) than those in normal tissues (n = 17). Reduced glutathione levels, and not oxidized glutathione levels, were found to be higher in normal tissues than those in tumoral tissues. We found no statistically significant difference between the adenocarcinoma and squamous cell carcinoma groups for any of the parameters studied.


Cancer Letters | 1996

Evaluation of some antioxidant enzymes in lung carcinoma tissue

Gül Güner; Hüray İşlekel; Öxtekin Oto; Eyüp Hazan; Ünal Açikel

This investigation was effected to determine the levels of the two antioxidant enzymes, superoxide dismutase (SOD) (EC 1.15.1.1) and catalase (CAT) (EC 1.11.1.6) in lung cancerous tissues and to compare with normal lung tissue in order to evaluate the antioxidant status in lung cancer. Fifteen lung carcinoma tissue samples and the normal counterparts from the same cases were homogenized and the cytosols obtained by ultracentrifugation (100,000 x g). SOD was assayed using a modification of the indirect nitroblue tetrazolium assay method, while CAT was measured by a spectrophotometric method. The data obtained are as follows: 1.42 +/- 0.24 U/mg protein (means +/- SEM) of SOD in lung cancer and 3.13 +/- 0.51 U/mg protein in normal lung tissue and 33.53 +/- 6.09 U/mg protein of CAT in lung cancer and 71.33 +/- 14.38 in normal lung tissue. The differences were found to be significant at the level of P < 0.01 for both enzymes. These low levels of the antioxidant enzymes in lung cancerous tissues can lead to elevated levels of reactive oxygen metabolites, resulting in damage to the key subcellular structures such as DNA, cell membranes, and other vital cellular components.


Urologia Internationalis | 2011

The Beneficial Effects of Tadalafil on Renal Ischemia-Reperfusion Injury in Rats

Mehmet Guzeloglu; Fatih Rüştü Yalçinkaya; Soner Atmaca; Alper Bagriyanik; Suleyman Oktar; Oguz Yuksel; Iyad Fansa; Eyüp Hazan

Acute renal failure due to ischemia-reperfusion (I/R) injury is a common complication in cardiovascular surgery. We determined the influence of tadalafil on renal injury in a renal I/R model in rats. For this purpose, 21 male Wistar albino rats were separated into 3 groups: sham, placebo and tadalafil. A right nephrectomy was performed, and the left renal pedicles were occluded for 60 min and reperfused for 60 min in the placebo and tadalafil groups. A single dose of tadalafil (10 mg/kg) through an orogastric tube was administered to the tadalafil group. Tubular atrophy with acute inflammation in renal histology, total oxidant status (TOS) and total antioxidant status (TAS) were determined in tissue homogenates. Compared to the tadalafil group, tubular atrophy and acute inflammation was significant in the placebo group. TAS levels were significantly higher in the tadalafil group compared to the placebo (p = 0.01) and sham groups (p = 0.04). While TOS levels were significantly higher in the placebo group (p = 0.03), tadalafil did not significantly alter the TOS levels. The beneficial effects of tadalafil can be attributed to its protective effects on renal tubular cells and inhibition of leukocyte infiltration in renal tissue. We think that tadalafil treatment has an important role in reducing renal injury resulting from renal I/R.


International Journal of Cardiac Imaging | 2000

Chylous ascites due to constrictive pericarditis.

Sema Güneri; Cem Nazli; Ozan Kinay; Önder Kirimli; Cem Mermut; Eyüp Hazan

Chylous ascites due to constrictive pericarditis is an extremely rare clinical entity, possibly caused by the augmented lymph production and high impedance to lymph drainage due to central venous hypertension. The authors describe a patient with chylous ascites caused by constrictive pericarditis in the absence of lymphatic obstruction. Cardiac catheterization is essential for the confirmation of accurate diagnosis of constrictive pericarditis. Magnetic resonance imaging of the heart is also very helpful in the diagnosis. The patient was symptom free and his ascites and edema completely resolved after pericardiectomy.


Angiology | 1997

Cervical Aortic Arch A Case Report

Ünal Açikel; Baran Ugurlu; Eyüp Hazan; Ergun Salman

Cervical aortic arch is a rare type of aortic arch anomaly that is presumed to result from persistence of the third aortic arch and regression of the normal fourth arch. Most of the patients with this anomaly are asymptomatic, but symptoms of dysphagia and respira tory distress due to the compression by the vascular ring have been reported. Other findings such as a supraclavicular pulsatile mass, blood pressure discrepancies between the upper limbs, and loss of femoral or opposite-upper-limb pulses with compression of the cervical mass may also be present. In this article a twenty-two-year-old woman with symptomatic cervical aortic arch is presented. The patient had a left cervical pulsatile mass and elevated blood pressure on her right upper limb and was treated surgically with reanastomosis of the aorta.


The Anatolian journal of cardiology | 2011

The effects of zoledronic acid on neointimal hyperplasia: a rabbit carotid anastomosis model.

Mehmet Guzeloglu; Mehmet Gül; Buket Reel; Ismail Yurekli; Koray Aykut; Eyüp Hazan

OBJECTIVE The aim of the present study was to investigate the effect of zoledronic acid (ZA), as a matrix metalloproteinase inhibitor, on neointimal hyperplasia in rabbit carotid anastomosis model. METHODS New Zealand male rabbits were divided into two groups as placebo and treatment groups in this experimental study. After anesthesia, the right carotid artery of each rabbit was end-to-end anastomosed with an 8/0 polypropylene suture. Left carotid artery was kept as control without any operation. Placebo group (n=6) received phosphate buffered saline (PBS) (0.5mL/kg/day/s.c.) for 28 days postoperatively, whereas ZA group (n=6) received ZA (100 µg/kg/day/s.c.) for the same period. After sacrification, the anastomosed and control arteries were isolated. Morphometric and immunohistochemical examinations were performed. Statistical analyses of morphometric and immunohistochemical data were performed using two-way ANOVA and Chi-square test respectively. RESULTS In PBS group, vascular injury in the anastomosed artery significantly increased the intimal area (anastomosed: 112.51±61.18 µm(2)*1000 vs. control: 22.62±4.26 µm(2)*1000, p<0.01) and intima/media index (anastomosed: 0.347±0.29 vs. control: 0.075±0.01, p<0.05) compared to control artery. ZA significantly reduced the intimal area (39.29±18.21 µm(2)*1000 , p<0.01) and intima/media index (0.112±0.07, p<0.05) compared to PBS group. Additionally, α-smooth muscle actin immunopositivity was found significantly decreased in anastomosed arteries from ZA group (ZA: 2.33±0.52 vs. PBS: 3.50±0.5, p<0.05). Moreover, intensive gelatinase (MMP-2 and MMP-9) immunoreactivities were clearly seen in anastomosed arteries compared to control arteries from PBS group. ZA apparently decreased immunopositivities for gelatinases in anastomosed arteries. CONCLUSION ZA might be a promising agent for prevention of neointimal hyperplasia, which is the most significant cause of graft failures in late postoperative period.


Asian Cardiovascular and Thoracic Annals | 2000

Stroke and Myxoma

Baran Ugurlu; Öztekin Oto; Hüseyin Okutan; Kürşat Kutluk; Erdem Silistreli; Nejat Sariosmanoglu; Eyüp Hazan; Aydanur Kargi

Cardiac myxoma was detected by transthoracic echocardiography in 8 patients (aged 11 to 64 years) who were admitted between 1991 and 1999 with stroke or transient ischemic attacks, representing 80% of the total myxoma cases treated in this period. All patients underwent surgery and the myxomas were successfully removed. There were no recurrences during a mean follow-up of 3.1 years. In the presence of unexplained transient ischemic attack, cerebral infarction, or syncope, this relatively rare cardiac lesion should be suspected and investigated by transthoracic echocardiography.


The Annals of Thoracic Surgery | 2002

Pleural flap for treating perigraft leak after a modified blalock-taussig shunt

Baran Ugurlu; Osman Nejat Sarıosmanoğlu; Sadik Kivanc Metin; Eyüp Hazan; Öztekin Oto

Plasa oozing through the graft after a modified Blalock-Taussig shunt is a troublesome complication. We encountered a massive leak following a modified Blalock-Taussig shunt in a 2 1/2 year-old-girl which required reexploration. The leak was treated by wrapping the polytetrafluoroethylene shunt with the parietal pleura flap harvested from the adjacent chest wall. The patient had an uneventful recovery. Covering of the polytetrafluoroethylene shunt with parietal pleura appears to stop plasma leak through the graft following a modified Blalock-Taussig shunt.


Journal of International Medical Research | 2008

Insulin—Blood Cardioplegia Decreases Matrix Metalloproteinase Activity in Ischaemia-reperfusion Injury during Coronary Artery Bypass Surgery

Hüdai Çatalyürek; G Oktay; M Guzeloglu; Z Çavdar; Ünal Açikel; Erdem Silistreli; Eyüp Hazan

Reperfusion of myocardium during coronary bypass activates matrix metalloproteinases (MMPs) with changes occurring in the levels of tissue inhibitors of metalloproteinases (TIMPs) in the myocardium. This study investigated the effects of insulin-blood cardioplegia on MMP activity and TIMP levels during reperfusion. Non-diabetic patients undergoing coronary artery bypass graft with cardiopulmonary bypass were randomized into a control group (n = 12) or an insulin group (n = 12). Blood cardioplegia was used for both groups; insulin and glucose were added to the insulin group. Blood samples were obtained from the coronary sinus just before aortic cross clamping and after 1 and 30 min of reperfusion. Plasma proenzyme MMPs (proMMP-2 and −9) and TIMPs (TIMP-1 and TIMP-2) levels were measured. There were no differences between groups for MMP-2 and TIMP-2 levels. However, insulin diminished proMMP-9 activation, although some still occurred. TIMP-1 consumption lessened during reperfusion which, we conclude, was as a result of the diminished MMP activation. This is the first open heart surgery study in which diminished MMP activation was achieved via a metabolic change.


Fundamental & Clinical Pharmacology | 2007

Vasorelaxant effect of iloprost on isolated human internal mammary artery

M.O. Serbest; B.C. Soner; O.N. Sariosmanoglu; S. Kalkan; B. Ugurlu; Eyüp Hazan; Öztekin Oto

In this study, vasodilator effect of iloprost on KCl‐induced contraction in human internal mammary artery (IMA) was studied and compared with other vasodilators papaverin and diltiazem. Ring segments of IMA were studied in organ baths for measurement of isometric tension. After the tissues has reached their baseline tension, precontraction was induced by 100 mm KCl and cumulative concentration–relaxation was measured by the application of iloprost (10−9–10−6 m), papaverine (10−5–10−4 m), diltiazem (10−9–10−4 m) or ethanol; a solvent for iloprost; alone. The maximal relaxation of IMA segments to iloprost was 13.5 ± 2.2%. Iloprost caused significantly limited relaxation when compared with papaverin (106.0 ± 2.9%) and diltiazem (93.6 ± 2.5%) (P < 0.001). Papaverin produced the greatest maximal relaxation to KCl‐induced contraction of IMA. The potency of iloprost (−log EC50 = 6.59 ± 0.19) was significantly higher than those of papaverine (−log EC50 = 4.21 ± 0.11) and diltiazem (−log EC50 = 5.63 ± 0.06) (P < 0.001). In addition, −log EC50 of diltiazem was significantly greater than papaverin (P < 0.001). Iloprost appears to be more potent than those of papaverine and diltiazem but it was inefficient in maximal inhibition on KCl‐induced contraction. Iloprost may have little benefit in KCl‐related vasoconstriction on human IMA segments.

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Öztekin Oto

Dokuz Eylül University

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Baran Ugurlu

Dokuz Eylül University

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