Fatma Ozyalin

Serum leptin, resistin, and lipid levels in patients with end stage renal failure with regard to dialysis modality.

Little information is available on the relationship between serum resistin levels and other adipokines with serum lipid levels and insulin resistance in uremic patients under different dialysis modalities. Methods. This study investigated the effects of dialysis modality on serum leptin, adiponectin, resistin, interleukin 6 (IL-6), and tumor necrosis factor (TNF) α levels in age, sex, and total adipose tissue mass (TATM); matched 30 hemodialysis (HD) patients, 30 continuous peritoneal dialysis (CAPD) patients, and 30 healthy controls; and evaluated the relationship between these adipokines and dyslipidemia and insulin resistance. Results. Serum resistin, adiponectin, IL-6, TNF-α, and high sensitive C reactive protein (hsCRP) levels were significantly increased in dialysis patients compared to controls (p < 0.05). In CAPD patients, serum leptin, resistin, triglycerides, and total cholesterol levels were higher than those in HD patients (p < 0.05). Leptin levels were positively correlated with TATM, serum triglycerides, total cholesterol, and low density lipoprotein (LDLc) levels in both dialysis groups. Resistin levels were found to positively correlate with TATM and triglycerides in CAPD patients. No relationship was found between the homeostasis model assessment-insulin resistance index (HOMA-IR) and adipokines studied. Conclusion. Serum leptin, resistin, triglycerides, and total cholesterol levels were higher in CAPD patients. Leptin levels were positively correlated with TATM, serum triglycerides, total cholesterol, and LDLc levels in dialysis patients. Resistin levels were positively correlated with TATM and triglycerides in CAPD patients. Glucose load during CAPD may be an important factor in increased in leptin, resistin, triglycerides, and total cholesterol levels in CAPD patients. These results highlight the importance of leptin and resistin as determinants of dyslipidemia, especially in CAPD patients.

Urinary Neutrophil Gelatinase-Associated Lipocalin as an Early Biomarker for Prediction of Acute Kidney Injury in Preterm Infants

BACKGROUND Our aims are to determine whether the urinary neutrophil gelatinase-associated lipocalin (uNGAL) can predict acute kidney injury (AKI) development in nonseptic and nonasphyxiated but critically ill preterm infants. METHODS Fifty preterm infants, gestational age (GA) between 28 and 34 weeks, were included in this case control study. Blood and urine samples were taken for blood urea nitrogen, serum creatinine, and uNGAL on postnatal (PN) days 1 and 7. uNGAL levels were measured by enzyme-linked immunoassay. Clinical and laboratory characteristics of the AKI group were compared with the non-AKI group. RESULTS AKI was diagnosed in six infants during the first week. The median uNGAL levels were significantly higher in the preterm infants with AKI than those of the controls on PN days 1 and 7 (p = 0.006 and p = 0.023, respectively). Backward stepwise logistic regression analysis identified that 5-minute Apgar score and uNGAL levels were significantly associated with the development of AKI, even after controlling for GA, birth weight, gender, and 1-minute Apgar score in nonseptic and nonasphyxiated but critically ill preterm infants. CONCLUSIONS uNGAL can be useful as a predictive marker of AKI in nonseptic and nonasphyxiated but critically ill preterm infants.

Ameliorative Effects of Resveratrol on Acute Ovarian Toxicity Induced by Total Body Irradiation in Young Adult Rats

OBJECTIVE The purpose of this study was to investigate the ovarian protective effects of resveratrol in rats exposed to total body irradiation. DESIGN Experimental study. SETTINGS University hospital. PARTICIPANTS AND INTERVENTIONS Thirty female rats were randomized into four groups: (1) control group (n = 7); (2) low-dose (10 mg/kg) resveratrol group (n = 8); (3) high-dose (100 mg/kg) resveratrol group (n =7); and (4) sham irradiation group (n = 8). The drugs were administered intraperitoneally as single doses, and the rats were exposed to total body radiation 24 h after the treatment. The animals were sacrificed the following day, and their ovaries were excised for histopathological and biochemical analysis. MAIN OUTCOME MEASURES The ovarian follicle counts were calculated, and irradiation-dependent ovarian damage and tissue levels of antioxidant enzymes were evaluated. RESULTS Group 2 and Group 3 showed significantly higher numbers of total follicle counts compared with Group 1 (P < 0.01). The low-dose resveratrol treatment was associated with significantly higher numbers of primary follicles than the high-dose group. The tissue activities of glutathione peroxidase (GsH-Px) and catalase (CAT) were significantly elevated in the resveratrol-treated animals. Evaluation of ovarian histology revealed no remarkable changes in fibrosis and leucocyte infiltration among the resveratrol-treated and control rats; however, vascularity was significantly reduced in the high-dose group (P = 0.014). CONCLUSION Resveratrol attenuated irradiation-dependent ovarian damage, suggesting that this natural antioxidant is effective in reducing the follicle loss induced by ionizing radiation.

The effects of intracerebroventricular infusion of irisin on feeding behaviour in rats

Irisin, a novel exercise-induced myokine, has attracted attention with its effects on energy metabolism. This study was conducted to determine the possible effects of irisin on nutritional behaviour. In this study, 40 male Wistar Albino rats were separated into 4 groups (n=10 for each group). Osmotic mini-pumps were connected to metal cannulas implanted to lateral ventricle; and artificial cerebrospinal fluid (vehicle), and 10 and 100nM of irisin was infused for 7days. The daily food and water consumptions and body weights of rats were followed up. After the infusion, the animals were killed, and the hypothalamus and blood samples were collected. NPY, POMC, and UCP2 mRNA levels in the hypothalamus were examined by RT-PCR. In serum, leptin and ghrelin levels as well as the levels of metabolic parameters were measured by using ELISA. It was determined that irisin administration increased the daily food consumption (p<0.05), without causing significant changes in water consumption and body weight. Irisin also caused increases in ghrelin level in circulation and NPY and UCP2 mRNA levels in the hypothalamus, whereas it decreased the leptin level in circulation and POMC mRNA levels in the hypothalamus (p<0.05). Otherwise, irisin caused decrease in LDL, triglycerides and cholesterol levels, while increasing HDL and glucose levels (p<0.05). Results indicates that long-term irisin treatment increases food intake without increasing body weight associated with increased ghrelin, NPY and UCP2 mRNAs, and decreased leptin and POMC mRNA in the hypothalamus.

Endothelial nitric oxide synthase levels and their response to exercise in patients with slow coronary flow

Summary Background Endothelial dysfunction plays a key role in the aetiopathogenesis of slow coronary flow (SCF) even if there is no obstructive epicardial lesion. Reduced plasma levels of endothelial nitric oxide synthase (eNOS) are an important indicator of endothelial dysfunction. We aimed to determine plasma levels of eNOS and their relationship with exercise in patients with SCF. Methods Twenty-two patients with SCF in at least one coronary artery and 17 healthy individuals were included in this study. The TIMI frame count method was used to determine SCF. Plasma levels of eNOS before and after effort were determined in the patient and control groups. Results Basal eNOS levels in the patient group were lower than in the control group (p = 0.040), and plasma eNOS levels after exercise decreased more significantly in the patient group compared to the control group (p = 0.002). Median decreases of eNOS in response to exercise were higher in the SCF group than in the control group (p < 0.001), and the decrease observed in the control group was not statistically significant (p = 0.35). There were significantly negative correlations between TIMI frame count and plasma levels of eNOS at baseline and after exercise (r = –0.51, p = 0.015, r = –0.58, p = 0.005, respectively). Moreover, there was also a positive correlation between the rate–pressure product and plasma levels of eNOS after exercise in patients with SCF (r = 0.494, p = 0.019). Conclusion Our findings indicate an important pathophysiological relationship between the severity of SCF in which endothelial dysfunction plays a role in its pathogenesis and the level of circulating plasma levels of eNOS.

Independent predictors of cardiovascular risk in polycystic ovarian syndrome

We aimed to determine the independent predictors of cardiovascular risk in polycystic ovarian syndrome (PCOS). Ninety-one PCOS and 51 control patients were enrolled to our prospective cross sectional case–control study. In early follicular phase hormonal and lipid profile, fasting insulin and CRP (hs-CRP) levels and glucose levels on fasting and 2 h after the 75 g glucose intake were determined. Insulin resistance (IR) was evaluated with homeostasis model assessment and free testosterone was determined with free androgen index. PCOS was found to be associated with dyslipidemia, hyperandrogenism, IR and sub-clinical inflammation. The prevalence of overweight–obesity (41.8% vs. 25.5%, p = 0.038), IR (42.9% vs. 23.5%, p = 0.035) and glucose intolerance (15.38% vs. 1.96%, p = 0.043) were significantly higher in PCOS compared to control group. Independent predictors of the risk of elevated hs-CRP level were PCOS status (OR = 5, 95% CI: 1.55–16.14, p = 0.007) and high BMI (OR = 4.2, 95% CI: 1.2−14.2, p = 0.022) and high BMI (OR = 1.2, 95% CI: 1.05−1.4, p = 0.007) and of TC/HDL ratio was high BMI (OR = 1.21, 95% CI: 1.05–1.4, p = 0.009) and increasing age (OR = 1.11, 95% CI: 1.01–1.2, p = 0.04). The presence of PCOS, independent from obesity and IR, is the strongest predictor of elevated hs-CRP level. Obesity and advanced age further increases the cardiovascular risk in PCOS.

NGAL and NT-proBNP levels in diabetic patients with macroproteinuria

Abstract Background: In patients with heart failure plasma N-terminal pro-brain natriuretic peptide (NT-proBNP) levels are correlated to urine neutrophil gelatinase-associated lipocalin (NGAL) levels. We prospectively evaluated the relationship among glomerular filtration rate (eGFR), urine albumin-to-creatinine ratio (ACR), urine and serum NGAL and NT-proBNP levels in 20 type II diabetic patients with macroalbuminuria at 4-month intervals. Results: Compared with 20 age, gender-matched healthy controls, diabetic patients had higher urine and serum NGAL, serum NT-proBNP and lower eGFR. The eGFR of the patients at the baseline, the 4th and the 8th month were 29.6 ± 12.0, 27.8 ± 13.7 and 22.9 ± 10.4 mL/min/1.73 m2, respectively. No significant change in urine NGAL levels was detected (p > 0.05), whereas there were significant increases in NT-proBNP, serum NGAL and urine ACR and significant decrease in eGFR as the study progressed (p < 0.05). Both the baseline and the 4th month urine ACR were positively correlated to NT-proBNP levels measured at the same periods (r: 0.451; p: 0.046; r: 0.489; p: 0.029 respectively). In all measurements, urine ACR was negatively correlated to serum albumin levels measured at the same periods (r: −0.792; p: 0.000; r: −0.716; p: 0.000; r: −0.531; p: 0.016 respectively). None of eGFR measurements was correlated with NT-proBNP (p > 0.05). Neither serum NGAL nor urinary NGAL levels are associated with NT-proBNP (p > 0.05). Conclusion: Our findings show an association between NT-proBNP and proteinuria in type II diabetic patients with macroalbuminuria but not with serum and urine NGAL.

Effects of apelin on reproductive functions: relationship with feeding behavior and energy metabolism

Abstract Apelin is an adipose tissue derived peptidergic hormone. In this study, 40 male Sprague–Dawley rats were used (four groups; n = 10). Apelin-13 at three different dosages (1, 5 and 50 μg/kg) was given intraperitoneally while the control group received vehicle the same route for a period of 14 days. In results, apelin-13 caused significant decreases in serum testosterone, luteinizing hormone and follicle-stimulating hormone levels (p < 0.05). Administration of apelin-13 significantly increased body weights, food intake, serum low-density lipoprotein and total cholesterol levels (p < 0.05), but caused significant decreases in high-density lipoprotein levels (p < 0.05). Serum glucose and triglyceride levels were not significantly altered by apelin-13 administration. Significant decreases in both uncoupling protein (UCP)-1 levels in the white and brown adipose tissues and UCP-3 levels in the biceps muscle (p < 0.05) were noted. The findings of the study suggest that apelin-13 may not only lead to obesity by increasing body weight but also cause infertility by suppressing reproductive hormones.

Resveratrol reduces light and electron microscopic changes in acetaminophen-induced hepatotoxicity in rats: Role of iNOS expression

ABSTRACT Introduction: Hepatotoxicity is a major complication of acetaminophen (APAP), a widely used analgesic and antipyretic drug. Resveratrol (RSV) is a naturally occurring diphenol and it has anticancer, antioxidant, and anti-inflammatory properties. Objectives: In this study, the beneficial effects of RSV on APAP-induced hepatotoxicity was investigated in rats. Materials and methods: Group 1: Ethanol, Group 2: Saline, Group 3: RSV (10 mg/kg/ip), Group 4: APAP (1000 mg/kg/ip/single dose), Group 5: APAP+RSV (20 min after administration of APAP). The rats were sacrificed 24 h after administration of APAP. Light and electron microscopic changes were evaluated. Levels of malondialdehyde (MDA) and glutathione (GSH), catalase (CAT), and superoxide dismutase (SOD) activities were determined in liver tissue. Results: Rats of the ethanol, saline, and RSV groups did not present any histopathological alterations. In the APAP group, we observed vascular congestion, necrosis, inflammation, sinusoidal dilatation, and loss of glycogen content. In the APAP+RSV group, these changes were markedly reduced. iNOS immunostaining showed very weak positive stained hepatocytes the sections of control, saline, and RSV groups. However, in the APAP group, iNOS immunostaining was most evident in pericentral hepatocytes. In the same areas in APAP+RSV group, intensity of iNOS immunostaining decreased. A significant increase in MDA and decreases in GSH level, CAT, and SOD activity indicated that APAP-induced hepatotoxicity was mediated through oxidative stress. Significant beneficial changes were noted in tissue oxidative stress indicators in rats treated with RSV. Conclusion: These biochemical, histopathological, and ultrastructural findings revealed that RSV reduced the severity of APAP-induced alterations in liver.

Central irisin administration suppresses thyroid hormone production but increases energy consumption in rats

Irisin, which is secreted from the skeletal muscle in response to physical exercise and defined as a thermogenic peptide, may play an important role in energy metabolism. Thyroid hormones, which are one of the other influential factors on the metabolic status, increase heat production and are the main regulators of energy metabolism. This study was conducted to determine the possible effects of irisin administration on thyroid hormones. Forty adult male Wistar albino rats were used in the study. The rats were equally divided into 4 groups (n = 10). The brain infusion kit was implanted in the groups, and irisin (or solvent as control) was centrally administered to the rats via osmotic mini pumps for 7 days. During the experiment, food consumption, body weights, and body temperatures of the animals were recorded. Food intake was significantly increased in the groups treated with irisin (p < 0.05), but their body weights were not changed. Hypothalamic TRH gene expression, serum TSH, fT3, and fT4 levels were significantly lower in the groups treated with irisin as compared to the naive and control groups (p < 0.05). In addition, irisin increased UCP1 mRNA expression in white and brown adipose tissue and UCP3 mRNA expression in muscle tissue in rats and also raised their body temperature (p < 0.05). Consequently, although central irisin administration has inhibitory effects on the hypothalamic-pituitary-thyroid axis, it seems to be an important agent in the regulation of food intake and energy metabolism.