Ahsen Yilmaz

Effect of CPAP on New Endothelial Dysfunction Marker, Endocan, in People With Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is associated with increased cardiovascular (CV) morbidity and mortality. Endocan is a surrogate endothelial dysfunction marker that may be associated with CV risk factors. In this study, we tested whether serum endocan is a biomarker for OSA. Serum endocan levels were measured at baseline in 40 patients with OSA and 40 healthy controls and after 3 months of continuous positive airway pressure (CPAP) treatment in the patients with OSA. All participants were evaluated by full polysomnography. Flow-mediated dilatation (FMD) and carotid intima media thickness (cIMT) were measured in all participants. Endocan levels were significantly higher in patients with OSA than in healthy controls. After adjusting confounders, endocan was a good predictor of OSA. Endocan levels correlated with OSA severity (measured by the apnea–hypopnea index [AHI]). After 3 months of CPAP treatment, endocan levels significantly decreased. Endocan levels were significantly and independently correlated with cIMT and FMD after multiple adjustments. The cIMT and FMD also had significant and independent correlation with AHI. Endocan might be a useful marker for the predisposition of patients with OSA to premature vascular disease.

The Effects of Quercetin on Acute Lung Injury and Biomarkers of Inflammation and Oxidative Stress in the Rat Model of Sepsis

Experimental studies indicate that sepsis causes remote organ injury although the molecular mechanism has not been clearly defined. In this report, the role of oxidative damage, and inflammation on lung injury, following sepsis model by cecal ligation and puncture, and the effects of quercetin, antioxidant, and anti-inflammatory flavonoid, in the lung tissue were investigated. In the present study, we found that administration of single-dose quercetin before cecal ligation and puncture procedure, while markedly diminishing the levels of YKL-40 and oxidant molecules (xanthine oxidase (XO), nitric oxide (NO), and malondialdehyde (MDA)), increases the antioxidant enzymes levels. Quercetin is beneficial to acute lung injury by decreasing the levels of oxidative stress markers and increasing the antioxidant enzyme activities. Quercetin also causes a decrease in the serum levels of YKL-40 and periostin in the oxidative lung injury induced by the experimental sepsis model.

The role of oxidants and reactive nitrogen species in irritable bowel syndrome: A potential etiological explanation

Background The aim of this study was to evaluate the plasma concentrations of malondialdehyde (MDA) and nitric oxide (NO) and the plasma activities of oxidant and antioxidant enzymes in patients with IBS. Material/Methods A total of 36 patients with IBS were included in the study. Thirty-five healthy subjects were selected to form the control group. Superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), xanthine oxidase (XO), adenosine deaminase (AD) activities, and malondialdehyde (MDA) and nitric oxide (NO) concentrations were studied in the serum samples of all patients and controls. Results Plasma XO and AD activities, and MDA and NO concentrations were significantly higher in IBS patients than in controls. The SOD, CAT, and GSH-Px activities in the serum of patients with IBS were significantly lower than that of controls. Conclusions These results suggest that lipid peroxidation and alterations in the oxidant-antioxidant enzymatic system may play a role in the pathogenesis of IBS. Increased lipid peroxidation in IBS may be related to an increase in NO level and XO activity and a decrease in antioxidant enzymes activities. In addition, increased AD activity may have a role in immunological changes of IBS patients.

The Effects of Ferulic Acid Against Oxidative Stress and Inflammation in Formaldehyde-Induced Hepatotoxicity

This study was designed to elucidate the protective effects of ferulic acid (FA) on formaldehyde-induced hepatotoxicity by measuring some routine biochemical parameters, cytokine levels, and oxidative stress-related parameters in addition to YKL-40 in male Wistar albino rats. Tissue superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) activities, and tissue malondialdehyde (MDA) levels were measured. Also, serum YKL-40, TNF-α, IL-6, IL-1β, IL-8, total protein, albumin, total bilirubin concentrations, and AST, ALT, ALP, and LDH activities were measured. Histological specimens were examined in light microscopy. Formaldehyde significantly increased tissue MDA, and serum cytokine levels and also decreased activities of antioxidant enzymes. FA treatment decreased MDA and cytokine levels and increased activities of antioxidant enzymes. FA also alleviated degeneration due to formaldehyde toxicity. We suggested that FA can be used as a promising hepatoprotective agent against formaldehyde toxicity because of the obvious beneficial effects on oxidative stress parameters.

The effects of melatonin on liver functions in arsenic-induced liver damage

OBJECTIVE Arsenic exposure is increasing in communities due to environmental pollution and industrial development. Arsenic is toxic to organ systems because it causes oxidative stress, enzymatic inhibition, and damage to protein structures. The liver, for example, is an organ that may be damaged by arsenic, and this damage may cause various clinical conditions like hepatic failure or cancer. Melatonin is a hormone that acts like an antioxidant, an anti-inflammatory agent, and a cytoprotective agent. In this study, we aimed to evaluate melatonins protective effects on livers damaged by arsenic toxicity. MATERIALS AND METHODS Twenty-four Sprague-Dawley male rats were classified into three groups: a control group, an arsenic applied group, and an arsenic plus 10 mg/kg melatonin applied group. At the end of the fifteen-day experiment, the rats were sacrificed. Albumin, interleukin-6 (IL-6), total protein, alanine transaminase, aspartate transaminase, macrophage migration inhibitory factor, and monocyte chemotactic protein-1 measurements were obtained. RESULTS In rats with liver damage due to arsenic exposure, melatonin administration significantly decreased the levels of IL-6, macrophage migration inhibitory factor, and monocyte chemotactic protein-1 (p<0.001, p=0.02 and p=0.04, respectively). CONCLUSION After evaluating liver enzymes and inflammatory markers, this study determined that melatonin exposure improves liver tissue damage caused by arsenic exposure, with the degree of improvement varying based on the levels of arsenic exposure.

Evaluation of Red Cell Distribution Width (RDW) in Diabetic Nephropathy Patients

Received: 4.4.2016 Accepted: 16.5.2016 1Namık Kemal University, School of Medicine, Internal Medicine Department 2Ministry of Health Tekirdag State Hospital, Endocrinology and Metabolism Clinics 3Ministry of Health Istanbul Goztepe Education and Training Hospital, Endocrinology and Metabolism Clinics 4Namık Kemal University, School of Medicine, Biochemistry Department yazışma adresi: Bülent Bilir, Namık Kemal University, School of Medicine, Internal Medicine Department, Tekirdag e-mail: bulentbilir@yahoo.com GİRİŞ