Metin Caner

Istanbul University, İstanbul, Istanbul, Turkey

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Publications (13)24.27 Total impact

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    ABSTRACT: Although hemorrhoids are one of the most common diseases in the world, the exact etiology underlying the development of hemorrhoids is not clear. Many different ointments are currently used to treat hemorrhoids; however, there is little evidence of the efficacy of these treatments to support their use. The aim of this study was to compare different herbal creams used for the treatment of hemorrhoids. Twenty-eight male Wistar albino rats, 6-8 weeks old and weighing 160-180 g, were used in this study as 1-control, 2-croton oil, 3-croton oil+fig leaves+artichoke leaves+walnut husks and 4-croton oil+fig leaves+artichoke leaves+walnut husks+horse chestnut fruit. After 3 days of croton oil application, rats were treated with 0.1 ml of cream or saline twice a day for 15 days by syringe. Tissue and blood samples were collected for histological, immunohistochemical and biochemical studies. Statistical significance was determined using one-way ANOVA followed by Tukey's multiple comparison tests. Croton oil administration resulted in severe inflammation. The third group showed partial improvement in inflammation; however, the greatest degree of improvement was seen in the fourth group, and some recovered areas were observed. Myeloperoxidase immunoreactivity was found to be decreased in the third and fourth groups compared to the second group. Additionally, biochemical analyses (Myeloperoxidase, Malondyaldehyde, nitrate/nitrite and nitrotyrosine levels and Superoxide Dismutase activity) were in agreement with the histological and immunohistochemical results. In conclusion, croton oil causes inflammation in the anal area and results in hemorrhoids. Treatment with our herbal hemorrhoid creams demonstrated anti-inflammatory and anti-oxidant effects in this model.
    The Chinese journal of physiology 10/2013; 56(5). · 1.28 Impact Factor
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    ABSTRACT: The effect of ezetimibe on blood lipids, oxidative stress, and fibrinolytic activity in hyperlipidemic patients was investigated after three months of therapy. Thirty hyperlipidemic patients were treated for twelve weeks with ezetimibe 10 mg/day. A healthy control group with matching age and gender was also included. Fasting blood glucose, lipid parameters, paraoxonase (PON1), protein carbonyl (PCO), oxidized LDL (oxLDL), 8-isoprostane (ISOPR), total antioxidant capacity (TAC) levels, tissue-type plasminogen activator (tPA), plasminogen activator inhibitor type-1 (PAI-1), and PAI-1/t-PA levels were evaluated. Ezetimibe therapy for twelve weeks led to changes in lipid profile in accordance with the literature. Fibrinolytic activity parameters, PAI-1/tPA and tPA-1 decreased, whereas PAI-1 levels did not change significantly. Antioxidant parameters, serum PON1 activity, and TAC levels increased significantly compared with the basal values. Oxidant parameters, oxLDL, ISOPR, and PCO (which is an indicator of oxidative protein damage) decreased significantly after therapy. Ezetimibe therapy has beneficial effects on fibrinolytic activity and homeostasis between oxidant and antioxidant activity in hyperlipidemic patients This may be through lowering lipid levels or other mechanisms such as decreasing insulin resistance and the pleiotropic effects of the drug.
    Southern medical journal 04/2010; 103(5):428-33. · 1.12 Impact Factor
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    ABSTRACT: Coenzyme Q10 is an important component of mitochondrial electron transport chain and antioxidant. Hyperthyroidism manifests hyperdynamic circulation with increased cardiac output, increased heart rate and decreased peripheral resistance. The heart is also under the oxidative stress in the hyperthyroidism. The aim of this study was to examine both how the coenzyme Q10 can affect heart ultrastructure in the hyperthyroidism and how the relationship between nitric oxide synthase (NOS) and heart damage and coenzyme Q10. Swiss Black C57 mice received 5 mg/kg L-thyroxine. Coenzyme Q10 (1.5 mg/kg) and L-thyroxine together was given to second group mice. Coenzyme Q10 and serum physiologic were applied to another two groups, respectively. All treatments were performed daily for 15 days by gavage. Free triiodothyronine and thyroxine were increased in two groups given L-thyroxine; thyroid-stimulating hormone level did not change. Hyperthyroid heart showed an increased endothelial NOS (eNOS) and inducible NOS (iNOS) immunoreactivity in the tissue. Coenzyme Q10 administration decreased these NOS immunoreactivities in the hyperthyroid animals. Cardiomyocytes of the hyperthyroid animals was characterized by abnormal shape and invaginated nuclei, and degenerative giant mitochondria. Desmosome plaques reduced in density. In hyperthyroid mice given coenzyme Q10, the structural disorganization and mitochondrial damage regressed. However, hearts of healthy mice given coenzyme Q10 displayed normal ultrastructure, except for increased mitochondria and some of them were partially damaged. Coenzyme Q10 increased the glycogen in the cardiomyocytes. In conclusion, coenzyme Q10 administration can prevent the ultrastructural disorganization and decrease the iNOS and eNOS increment in the hyperthyroid heart.
    The Chinese journal of physiology 11/2007; 50(5):217-24. · 1.28 Impact Factor
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    ABSTRACT: The present study was designed to determine whether artichoke (Cynara scolymus) exerts a protective effect on gonads of cadmium-treated rats and if there is a relationship between artichoke supplementation and nitric oxide (NO) formation in cells. Forty Wistar albino male rats, weighing an average of 90 g each, were equally divided into four groups receiving 1 mg/100 g cadmium chloride by injection (group 1), the same dose CdCl2 plus 3 mg/100 g artichoke extract (group 2), the same dose of artichoke extract (group 3), and male controls (group 4). Four additional groups, labeled 5-8, consisted of identically treated and control female rats. After 4 weeks of treatment, the animals were killed and their gonads were removed for histological examination. As expected, the seminiferous tubules and Leydig cells were damaged by cadmium. Ovarian tissue was not damaged to the same extent as testicular cells. Artichoke extract exerted a clear protective effect against Cd-induced testicular damage and lowered NO production to the same level of that in the control groups.
    Biological Trace Element Research 11/2007; 119(1):51-9. · 1.61 Impact Factor
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    ABSTRACT: Statins provide strong clinical benefits via reducing stroke deaths, and they are also considered for tumor reduction and chemo-sensitization. High dose atorvastatin in adults (80 mg daily, approx. 1 mg/kg) is proven to afford greater protection against cardiac deaths than does a standard lipid-lowering dose in coronary syndrome. For cancer trials, mega doses up to 30 mg/kg have been used for short term treatments but neither a high nor a mega-dose of atorvastatin has been tested for long term cardiac safety. This may be of special concern, since some animal studies showed deleterious effects of statins on cardiac tissue, which may be related with coenzymeQ (CoQ) depletion. We performed an electron microscopic analysis of rat hearts after low, high-or mega-dose atorvastatin therapy and with or without MNU (methyl-nitrosourea)-stress. MNU + daily high dose atorvastatin treatment for 13 months did not produce severe cardiac toxicity with CoQ. However, at mega doses (30 mg/kg) and with MNU, mitochondrial damage and myofibrillary disintegration was obvious. Strong proliferation of mitochondria under high dose atorvastatin therapy with CoQ may explain the lack of cardiotoxicity; and this finding seems to parallel recent data that statins induce HNF-4 and PPAR-alpha, both responsible for mitochondria-proliferation. Employment of statins for tumor chemo-sensitization at high-dosage and for long term treatments may require strategies to direct the mevalonate-entry differentially into cardiac and tumor cells and to develop a protocol analogous to folic acid salvage of methotrexate toxicity.
    Cell Biochemistry and Function 07/2007; 25(4):463-72. · 2.13 Impact Factor
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    ABSTRACT: Oxidative stress is thought to play a critical role in the pathogenesis of hypertension. Protein oxidation is defined here as the covalent modification of a protein induced either directly by reactive oxygen species or indirectly by reaction with secondary by-products of oxidative stress. The aim of our study was to evaluate the protein oxidation and to examine the function of the antioxidative system in sustained and white coat hypertensives (WCH) and compare with normotensives. This study was designed to investigate the protein oxidation parameters [protein carbonyls (PCOs)] in sustained hypertensives (17 males and 20 females) and WCH (18 males and 19 females). PCO and the endogenous antioxidant components protein thiol (P-SH), CuZn-superoxide dismutase (CuZn-SOD) and glutathione (GSH) were analysed using spectrophotometric and kinetic methods. Sustained hypertensive and WCH groups exhibited higher protein oxidation and lower P-SH, CuZn-SOD and GSH activities than normotensives. With regard to these parameters, there was no significant difference between sustained hypertensive and WCH groups. Blood pressure correlates positively with PCO groups and negatively with others. There exists an imbalance between oxidants and antioxidants in WCH because of the increase of oxidants associated with the decrease of antioxidant capacity. This may cause endothelial dysfunction just like in sustained hypertension. It may be necessary to add antioxidants to conventional antihypertensive therapy to balance the oxidative status in WCH.
    International Journal of Clinical Practice 01/2007; 60(12):1565-71. · 2.54 Impact Factor
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    ABSTRACT: Oxygen free radicals are important components involved in the pathophysiological processes observed during ischemia/reperfusion (I/R). This study was designed to assess the possible protective effect of montelukast, a selective antagonist of cysteinyl leukotriene receptor 1 (CysLT1), on renal I/R injury. Wistar albino rats were unilaterally nephrectomized and subjected to 45 min of renal pedicle occlusion followed by 6 h of reperfusion. Montelukast (10 mgkg(-1), i.p.) or saline was administered at 15 min prior to ischemia and immediately before the reperfusion period. At the end of the reperfusion period, following decapitation, kidney samples were taken for histological examination or for determination of renal malondialdehyde (MDA), an end product of lipid peroxidation; glutathione (GSH), a key antioxidant; and myeloperoxidase (MPO) activity, an index of tissue neutrophil infiltration. Formation of reactive oxygen species in renal tissue samples was monitored by using chemiluminescence (CL) technique with luminol and lucigenin probes. Creatinine, blood urea nitrogen and lactate dehydrogenase (LDH) activity were measured in the serum samples, while leukotriene B4, TNF-alpha, IL-beta, IL-6 and total antioxidant capacity (AOC) were assayed in plasma samples. Ischemia/reperfusion caused a significant decrease in renal GSH and plasma AOC, which was accompanied with significant increases in MDA level, MPO activity, and CL levels of the renal tissue concomitant with increased levels of the pro-inflammatory mediators, LDH activity, creatinine and BUN. On the other hand, montelukast treatment reversed all these biochemical indices as well as histopathological alterations induced by I/R. CysLT1 receptor antagonist montelukast reversed I/R-induced oxidant responses, improved microscopic damage and renal function. It seems likely that montelukast protects kidney tissue by inhibiting neutrophil infiltration, balancing oxidant-antioxidant status, and regulating the generation of inflammatory mediators.
    Pharmacological Research 08/2006; 54(1):65-71. · 3.98 Impact Factor
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    ABSTRACT: Upper respiratory tract (URT) involvement is rare in sarcoidosis. In this descriptive study, we retrospectively evaluated the clinical and demographic features of 12 (2.19%) patients with URT involvement out of the 546 sarcoidosis patients with follow-up visits at our center within the last 40-year period. Out of the 546 patients, 12 (2.19%) had upper respiratory tract involvement, 5 (0.91%) had laryngeal involvement, 4 (0.73%) had sinonasal tract involvement, 2 (0.36) patients had salivary gland involvement, and 1 patient had tonsillary involvement. The number of stage 0 subjects among other sarcoidosis patients was significantly lower than that among those with URT involvement. URT involvement is rarely diagnosed in patients with systemic sarcoidosis. The most common site for URT involvement among the Turkish population is the larynx, followed by the sinonasal tract. EBM rating: C-4.
    Otolaryngology Head and Neck Surgery 06/2006; 134(5):848-51. · 1.72 Impact Factor
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    ABSTRACT: Mediastinoscopy was performed for confirmation of the diagnosis in 68 patients who were suspected clinically and radiologically of having sarcoidosis. In 66 of 68 cases in which mediastioscopy was performed a diagnosis was attained. In 35 cases, endobronchial biopsy was performed by bronchoscopy. In only 5 of these (14.2 %) was the diagnosis of sarcoidosis confirmed. The sensitivity of mediastinoscopy was remarkably superior compared with that of endobronchial biopsy. No complication developed with either mediastinoscopy or endobronchial biopsy. In Turkey, mediastinoscopy without any complication costs about 650 USD while bronchoscopy and endobronchial biopsy cost about 150 USD. In our study in which we looked for a histological confirmation -- in the cases suspected of sarcoidosis -- mainly through mediastinoscopy and rarely through other methods (i.e., endobronchial biopsy in one case, skin biopsy in another), we did not come up with a different diagnosis. Therefore, patients suspected of having sarcoidosis should undergo a careful clinical, laboratory, and radiologic examination; they should be under continuous close observation; when necessary (e.g., skin and lip biopsy), the tissue diagnosis should be made by other methods, but if there is the possibility of a disease such as tuberculosis and lymphoma, mediastinoscopy should be performed. The diagnosis of stage 3 sarcoidosis is difficult. For diagnosis, sometimes videothoracoscopy or explorative thoracotomy may be necessary. However, in all our 3 cases with stage 3, we reached the diagnosis of sarcoidosis by the less invasive and less expensive method of mediastinoscopy. Despite our small number of cases, we believe that mediastinoscopy is a very important instrument for diagnosis of stage 3 sarcoidosis.
    The Thoracic and Cardiovascular Surgeon 05/2006; 54(3):198-201. · 1.08 Impact Factor
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    ABSTRACT: Cerebral tuberculoma is a rare entity and is one of the causes of intracerebral mass lesions. A rapid diagnosis based on pathological findings improves its prognosis. We describe two cases where the tuberculoma was located in the cavernous sinus and prepontine cistern, respectively. The first case was a 36-year-old man who was admitted with progressive headache, left ptosis and diplopia. Computed tomography showed a solid enhancing mass in the left cavernous sinus. Diagnosis of meningioma was proposed and a left pterional craniotomy was performed. Histopathological examination revealed granulomatous inflammation with areas of caseation necrosis. The second case was a 20-year-old man who presented with headache, new-onset strabismus, diplopia, malaise, weight loss and low-grade fever. The lesion mimicked an aggressive meningioma on imaging. The patient was operated for primary diagnosis of cerebral tumour. The histopathological examination of the excised lesion revealed a tuberculoma. Although the incidence of tuberculosis is decreasing, a high index of suspicion must be maintained for the diagnosis of intracranial masses in the presence of risk factors for tuberculosis.
    Singapore medical journal 01/2006; 46(12):731-3. · 0.63 Impact Factor
  • Pharmacological Research 01/2006; 54(1):65-71. · 3.98 Impact Factor
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    ABSTRACT: Nitric oxide (NO) is known to be a messenger molecule that plays an important role in physiological and pathological conditions. It is synthesized by an enzyme called nitric oxide synthase (NOS). Inducible NOS (iNOS), one of the three isomers of NOS, has both protective and toxic properties. In this study, the role of NO has been evaluated by gastrointestinal symptoms induced by orlistat which is used in obesity treatment. Orlistat was given to Wistar rats with and without iNOS inhibition. The effects of orlistat and inhibition of NOS were studied. Glucose, urea, alanine transaminase (ALT), and gamma glutamil transpeptidase (GGT) were descreased after short- and long- term orlistat applications. Dexamethasone increased level of these enzymes. Cholesterol and triglyceride were increased in all experimental groups than the controls. This increment was more severe in animals received orlistat and dexamethasone together. Small intestinal tissue also were researched histologically and NADPH-diaphorase (NADPH-d) histochemistrically. Orlistat caused histological damages in brush border membranes, connective tissues of villi, and lymphocyte migration also increased. Dexamethasone treatment prevented these damages partially while orlistat increased the NOS distribution in the tissue sections. Dexamethasone, which is an iNOS inhibitor, decreased NADPH-d histochemistry. There was a similiar NOS distribution both in the control and orlistat+dexamethasone group. Hence, we concluded that long- term trials with orlistat and similar drugs are needed.
    The Chinese journal of physiology 01/2006; 48(4):217-22. · 1.28 Impact Factor
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    ABSTRACT: A peripheral lymph node (PLN) 1 cm or greater was found in 79 of 546 sarcoidosis patients (14.5%) between 1972 and 2005. Seventy-two of the 79 sarcoidosis patients had a lymph node biopsy performed. Sixty-seven of these biopsy specimens were histologically diagnosed as sarcoidosis, whereas five patients had a reactive adenopathy. For patients with histological diagnosis of sarcoidosis, localizations of the biopsies were as follows: cervical (n=21), supraclavicular (n=20), inguinal (n=11), axillary (n=8), epitrochlear (n=5) and submandibular (n=2). At the time of biopsy, 12 patients had stage 0 disease, 37 patients had stage I disease, 14 patients had stage II disease and four patients had stage III disease. Skin involvement (16.4%) was the most frequently observed type of organ involvement in patients who had enlarged PLNs due to sarcoidosis. In the presence of an enlarged PLN in sarcoidosis, biopsy had a greater diagnostic value compared with other methods, as well as having a relatively low cost (approximately US$120) in Turkey. No procedure-related complications were observed. In conclusion, it is recommended that PLNs be thoroughly examined when sarcoidosis is suspected. If an enlarged PLN is found, biopsy should be routinely performed because it is an easy, convenient and practical method, with a low complication risk and a high sensitivity.
    Canadian respiratory journal: journal of the Canadian Thoracic Society 14(4):209-11. · 1.66 Impact Factor