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Öğe Anti-oxidant status in relation to lipoproteins, leptin and pro-inflammatory cytokines in children with steroid-sensitive nephrotic syndrome(Blackwell Publishing Asia, 2004) Ece, A; Atamer, Y; Gürkan, F; Bilici, M; Koçyigit, YBackground: Reactive oxygen species and cytokines are reported to play a role in the proteinuria of nephrotic syndrome. The aim of this study was to investigate indirect evidence of oxidant activity together with leptin, lipoproteins and pro-inflammatory cytokines in children with steroid-sensitive nephrotic syndrome. Methods: A total of 40 children with steroid-sensitive nephrotic syndrome (20 with newly onset or relapse comprised group I and 20 in remission while receiving steroids comprised group II) and 20 sex and age matched healthy control children were included. The following indirect parameters of oxidant activity were determined: serum malondialdehyde, erythrocyte superoxide dismutase, catalase and whole-blood-reduced glutathione. Serum leptin, lipids and lipoproteins were also determined. Results: Similar glutathione, increased malondialdehyde levels and decreased superoxide dismutase and catalase activity were observed in group I patients compared with controls. There was no significant difference in these variables between group I and group II (P > 0.05). Tumour necrosis factor-alpha and interleukin-6 concentrations were similar in patients and controls. Concentrations of interleukin-1beta and interleukin-8 were higher in the active phase of nephrotics compared with controls (P < 0.05). Significant positive correlations were found between malondialdehyde and interleukin-1beta, interleukin-6, leptin and lipoprotein (a) (P < 0.05). There were significant negative correlations between anti-oxidants and leptin, lipoprotein (a) and several cytokines (P < 0.05). Conclusions: Changes in the concentrations of malondialdehyde, superoxide dismutase, catalase and glutathione are compatible with increased amounts of oxidation in steroid-sensitive nephrotic syndrome. Leptin and pro-inflammatory cytokines may be related to excessive protein permeability in nephrotic syndrome.Öğe Changes in serum levels of leptin, cytokines and lipoprotein in preeclamptic and normotensive pregnant women(Parthenon Publishing Group, 2004) Koçyigit, Y; Atamer, Y; Atamer, A; Tuzcu, A; Akkus, ZThe aim of this study was to investigate the changes in serum levels of leptin, cytokines and lipoproteins in women with pre-eclampsia and to evaluate their clinical significance in the pathogenesis of pre-eclampsia. We performed a prospective study involving 45 women with pre-eclampsia in the third trimester of pregnancy and 30 normotensive women in the third trimester of pregnancy. Serum level of leptin was measured by enzyme immunoassay using a Cayman chemical kit, Serum levels of tumor necrosis factor (TNF)-alpha, intertleukin (IL)-1beta, soluble IL-2 receptor (sIL-2R), IL-6 and IL-8 were measured by using a nonradioimmunoassay chemiluminescent method. Serum lipid concentrations were measured by an Abbott Aeroset (USA) autoanalyzer. Serum levels of apolipoprotein (Apo)A-I and ApoB were evaluated by nephelometrics assays. Differences between groups were evaluated with Student's unpaired t test and, when a variable was not normally distributed, the Mann-Whitney U test was used. The relationship between the variable was explored by the Pearson correlation test. Serum levels of leptin, TNF-alpha, IL-1beta, sIL-2R, IL-6 and IL-8 in the preeclamptic women were significantly higher than in normotensive women (p < 0.001). In the pre-eclamptic women serum levels of triglycerides, total cholesterol and low-density lipoprotein (LDL)-cholesterol were significantly increased (p < 0.001), while high-density lipoprotein (HDL)-cholesterol and Apo-A were significantly decreased compared to levels in normotensive pregnant women (p < 0.001). No significant differences were noted between the groups in Apo-? (p > 0.05). Serum levels of TNF-? were significantly correlated with the serum levels of IL-6, IL-8, triglycerides, sIL-2R, Apo-A and hematocrit in pre-eclamptic women (r = 0.418, p < 0.05 - r = 0.389, p < 0.01; r = 0.312, p < 0.05; r 0.318, p < 0.05; r 0.340, p < 0.05 and r = 0.41, p < 0,01, respectively). A negative correlation was seen between serum level of leptin and both IL-1? and Apo-A in pre-eclamptic women (r = 0.44, p < 0.05; r = 0.39, p < 0.05, respectively). Serum levels of IL-6 were also signficantly correlated with the serum levels of HDL-cholesterol, LDL-cholesterol and body mass index (BMI) in preeclamptic women (r = 0.40, p < 0.01; r = 0.568, p < 0. 0 1; r 0. 3 0, p < 0. 05, respectively). In addition, serum level of IL-8 were significantly correlated with the serum levels of HDL-cholesterol, total cholesterol and BMI in pre-eclamptic women (r = 0.368, p < 0.05; r = 0.513, p < 0.01 and r = 0.41, p < 0.01, respectively). We found that the pre-eclampsia associated with increases in serum levels of leptin, TNF-?, cytokines, triglycerides, total cholesterol and LDL-cholesterol was associated with a significant reduction in serum levels of HDL-cholesterol and Apo-A. These association may be due to the abnormal lipid metabolism and immune activation involved in the pathogenesis of this disease.Öğe Lipid peroxidation, antioxidant defense, status of trace metals and leptin levels in preeclampsia(Elsevier Sci Ireland Ltd, 2005) Atamer, Y; Koçyigit, Y; Yokus, B; Atamer, A; Erden, ACObjective: To investigate the changes in enzyme activities of erythrocyte superoxide dismutase (SOD), catalase, and placental glutathione peroxidase (GSH-Px), and analyze the levels of serum malondialdehyde (MDA), copper (Cu), zinc (Zn), selenium (Se), leptin and placental MDA and glutathione (GSH). Study Design: Cross-sectional prospective study consisting of 32 preeclamptic (PE) pregnant, 25 non-pregnant (NP) women, 28 healthy pregnant (HP) women. Levels of lipid peroxides in serum and placenta, and activities of SOD, catalase in erythrocyte and placental GSH level, placental GSH-Px activity were measured by spectrophotometric methods. Serum levels of Cu, Zn, Se measured by atomic absorption spectrophotometry. Serum levels of leptin was measured by enzyme immunoassay by using the Cayman chemical kit. One-way analysis of variance and post hoc Tukey-HSD test and Pearson correlation test were used for the statistical analyses. Results: Serum levels of MDA, Cu, Leptin were markedly higher (P < 0.001); and serum level of Se was markedly lower (P < 0.001) in PE women compared with HP women and NP women. Also, placental MDA level was higher (P < 0.001) and placental GSH-Px activity was lower in PE women compared with HP women. In preeclamptic women erythrocyte catalase activity was markedly increased (P < 0.001), while erythrocyte SOD activity was markedly decreased (P < 0.001) compared to HP women and NP women. Placental GSH level was decreased compared to HP women (P < 0.001). Serum level of Zn was markedly decreased compared to NP women (P < 0.001) but no significant difference was observed in PE pregnant when compared with HP women (P > 0.05). Placental MDA level in PE women had significant negative correlation with serum Se level (r = -0.353, P < 0.05). A negative correlation was found between erythrocyte catalase activity with birth weight (r = -0.528, P < 0.001). Also, there were a significant negative correlation between serum levels of Cu and Se in the preeclamptic women (r = -0.407, P < 0.05). Conclusion: Our data demonstrate that elevation of lipid peroxides together with impaired antioxidant defense mechanisms and status of trace metals and the presence of possible interrelationship and crosstalk between those parameters may be related at least partly to the pathogenesis of preeclampsia. Additionally, lipid peroxides and blood oxidative imbalance could be part of the cytotoxic mechanisms leading to endothelial cell injury. (c) 2004 Elsevier Ireland Ltd. All rights reserved.Öğe Oxidative stress, inflammation and early cardiovascular damage in children with chronic renal failure(Springer, 2006) Ece, A; Gürkan, F; Kervancioglu, M; Kocamaz, H; Günes, A; Atamer, Y; Selek, SThe relationship between inflammation, oxidant stress and cardiovascular damage in children with chronic renal failure (CRF) has not previously been investigated. The aim of this study was to investigate markers of oxidative stress, inflammation and early cardiovascular abnormalities. Therefore, erythrocyte superoxide dismutase (SOD) and catalase (CAT) activities; blood glutathione (GSH) and serum malondialdehyde (MDA) levels; C-reactive protein (CRP) and proinflammatory cytokines (IL-6, TNF-alpha,); and left ventricular masses (LVM) and intima media thicknesses (IMT) were measured in children with CRF. A total of 29 children with CRF (19 nondialysis, 10 peritoneal dialysis) were included. The control group consisted of 25 healthy subjects. CRF children had significantly increased IL-6, TNF-alpha, CRP and MDA concentrations and decreased SOD, CAT and GSH levels compared with controls (P < 0.05). Nondialysis and peritoneal dialysis subgroups had similar oxidative stress and inflammation biomarkers (P > 0.05). Erythrocyte CAT was positively correlated with CRP, TNF-alpha, and IL2-R in the study group. Positive correlations were found between cytokine concentrations, CRP and urea/creatinine levels. Significantly increased LVM and IMT values were found in CRF children (P < 0.05). In conclusion, increased oxidant stress and inflammation together with early cardiovascular damage were found in CRF children. Further studies with more patients are needed to verify these results.Öğe Paraoxonase, anti-oxidant response and oxidative stress in children with chronic renal failure(Springer, 2006) Ece, A; Atamer, Y; Gürkan, F; Davutoglu, M; Bilici, M; Tutanç, M; Günes, AIncreased oxidative stress is believed to contribute to an increased risk of cardiovascular disease in uraemia. In children with chronic renal failure (CRF), an anti-oxidant enzyme, paraoxonase (PON), that inhibits oxidation of LDL-cholesterol, has not been previously investigated. In this study we aimed to investigate PON activity, total anti-oxidant response (TAR), total peroxide (TPX), oxidative stress index (OSI) and some pro-oxidant cytokines in 29 children with CRF [mean age 10.2 +/- 3.5 years; 19 pre-dialysis, ten on continuous ambulatory peritoneal dialysis (CAPD)] and in 25 control subjects. Children with CRF had lower PON and TAR and higher TPX and OSI values than did controls (P<0.05). Except for lower TAR and serum albumin levels of the CAPD subgroup (P<0.05), other parameters were similar in non-dialysis and CAPD patients (P>0.05). Patients had significant positive correlation between TAR and serum albumin (P<0.05). Serum urea had significant positive correlation with TPX and OSI (P<0.05). Increased oxidative stress and decreased anti-oxidants measured by serum PON activity and TAR were found in children with CRF. We can hypothesize, on the basis of statistical correlations, that low levels of serum albumin and high levels of uraemic metabolites might be responsible for increased oxidative stress in children with CRF. Further studies with larger sample sizes are needed to verify these results.Öğe Paraoxonase, total antioxidant response, and peroxide levels in children with steroid-sensitive nephrotic syndrome(Springer, 2005) Ece, A; Atamer, Y; Gürkan, F; Davutoglu, M; Koçyigit, Y; Tutanç, MReactive oxygen species (ROS) are reported to play a role in inducing the proteinuria of nephrotic syndrome (NS). This study investigated paraoxonase (PON), total antioxidant response (TAR), and oxidant total peroxide together with serum proteins and lipoproteins in children with steroid-sensitive NS. The study included 40 children with steroid-sensitive NS (21 with acute-period NS in group I, 19 nonproteinuric while receiving steroids in group II) and 22 sex- and age-matched formerly nephrotic children in remission weaned from steroids (group III). The following parameters were determined: total peroxide, oxidative stress index (OSI), PON and TAR. Serum proteins and lipoproteins were also determined. Patients in the active phase of NS had significantly lower PON and TAR levels and higher OSI and total peroxide values than those in full remission; no differences were found in PON, TAR, or OSI values of groups I and II. Significant correlations were found between PON, TAR, and total peroxide. Serum total protein had a significantly positive correlation with PON and negative correlation with total peroxide in acute-period NS patients. Our results demonstrate greater oxidative stress and decreased antioxidants in the active phase of steroid-sensitive NS and while patients receive steroids than during full remission. Low-dose alternate-day steroids do not seem to decrease oxidative stress even while proteinuria ceases. Despite some conflicting data increased oxidation and/or decreased antioxidant response may be related to the pathogenesis of steroid-sensitive NS.Öğe Potential atherogenic roles of lipids, lipoprotein(a) and lipid peroxidation in preeclampsia(Taylor & Francis Ltd, 2005) Bayhan, GH; Koçyigit, Y; Atamer, A; Atamer, Y; Akkus, ZAims. To evaluate changes in lipid profile, serum levels of malondialdehyde (MDA) and lipoprotein(a) (Lp(a)) and placental MDA in preeclamptic women, and to evaluate the atherogenic role of these changes in the pathophysiology of preeclampsia. Method. A cross-sectional study was performed in 20 normal pregnant women, 25 women with mild preeclampsia and 28 women with severe preeclampsia in the third trimester. MDA, which is the endproduct of lipid peroxidation, was measured in placental tissue by the thiobarbituric acid (TBA) method of Ohkawa and colleagues and in serum by the TBA method of Asakawa and Matsushita. Serum lipid levels were measured by with an autoanalyzer, serum apolipoprotein (Apo) A-I and Apo B were measured by nephelometric assay and serum Lp(a) level using a nephelometric agglutination assay method. In preeclamptic and normal pregnant women, multiple comparisons between groups were performed by one-way analysis of variance supplemented with Tukey's HSD post hoc test. The association between placental and serum concentrations among groups was analyzed using the Pearson correlation test. Results. Serum levels of MDA, Lp(a), total cholesterol, triglycerides (TG), low-density lipoprotein cholesterol (LDL-C) and placental MDA were significantly higher, and high-density lipoprotein cholesterol (HDL-C) and Apo A-I levels were significantly lower, in severely preeclamptic and mildly preeclamptic women than in the normal pregnant women, but no difference was observed in Apo B among groups. Serum level of Lp(a) was positively correlated with body mass index in severely preeclamptic women (r = 0.489:, p = 0.008). A significant positive correlation was also found between serum level of MDA and systolic blood pressure in women with severe preeclampsia (r = 0.375, p = 0.049). Conclusions. Our findings suggest that high Lp(a), lipid peroxidation, LDL-C and TG, and low HDL-C and Apo A-I levels, are important risk factors for atherosclerosis among preeclamptic women.Öğe Relationship among serum selenium levels, lipid peroxidation, and acute bronchiolitis in infancy(Humana Press Inc, 2004) Gurkan, F; Atamer, Y; Ece, A; Kocyigit, Y; Tuzun, H; Mete, MThirty-four infants with acute bronchiolitis and 25 age-matched healthy controls were enrolled to investigate the possible relationship between serum malondialdehyde (MDA) and selenium (Se) levels and the occurrence and severity of acute bronchiolitis in children. Serum samples were taken for serum Se and MDA measurements, and the clinical score was assessed at admission. Blood was taken again from the children with bronchiolitis at 2 mo after discharge from the hospital. Mean serum MDA levels were significantly higher in patients with acute bronchiolitis than at the postbronchiolitis stage and the controls (4.2+/-2.5 nmol/L, 1.4+/-0.8 nmol/L, and 0.7+/-0.2 nmol/L, respectively [p<0.001]). Infants with bronchiolitis had lower mean serum Se levels at the acute stage than after 2 mo (31.7+/-28.9 mug/L versus 68.4+/-26.4 mug/L, p<0.05, respectively); both of which were significantly lower than the control group measurements (145.0+/-21.9 mug/L) (p<0.001). There was a negative correlation between serum MDA and Se levels in the patient group (r=-0.85, p<0.001). The age of the patient, child's immunization status, parental smoking habit, and family crowding index were not correlated with serum Se, MDA levels, or clinical score at admission. In conclusion, increased MDA levels and impaired Se status demonstrate the presence of possible relationship of these parameters with pathogenesis of acute bronchiolitis, and antioxidant supplementation with Se might be thought to supply a beneficial effect against bronchiolitis.Öğe The relationship between plasma levels of leptin and androgen in healthy and preeclamptic pregnant women(Blackwell Munksgaard, 2004) Atamer, Y; Erden, AC; Demir, B; Koçyigit, Y; Atamer, ABackground To clarify the role of leptin and androgens in the pathogenesis of preeclampsia, we wanted to assess role of maternal leptin in women with severe and mild preeclampsia and the effects of sex steroid hormones on leptin production. Methods. The groups consisted of 40 healthy pregnant women (HPW) as well as 55 pregnant women with severe preeclampsia (SPE) and 41 pregnant women with mild preeclampsia (MPE). No significant differences were observed between the three groups regarding age, gestational age and body mass index (BMI). Plasma leptin, total testosterone (T), estradiol (EA dehydroepiandrosterone sulfate (DHEAS) and androstenedione (A) levels were measured. Statistical analysis was achieved with one-way analysis of variance (ANOVA) followed by post hoc multiple comparisons with the Tukey honestly significant difference (HSD) test by using SPSS for Windows statistical computer program, and the Pearson's coefficient of correlation was calculated. Results. The plasma level of leptin was significantly increased in the SPE and MPE groups (p < 0.001), whereas the plasma level of T was significantly increased only in the SPE group (p < 0.001). However, there was no significant difference in plasma levels of DHEAS among the three groups (p < 0.05). The plasma level of A was significantly decreased in the MPE group (p < 0.05). There was no significant difference in the plasma level of E-2 in the MPE and SPE groups (p < 0.05). There was a significant positive correlation between the plasma levels of leptin and E-2 in the MPE group (r = 0.41, P < 0.001). Conclusion. We concluded that the elevated plasma levels of leptin and testosterone could contribute to the endothelial dysfunction involved in the pathogenesis of preeclampsia, and that estradiol might lead to an increase in the plasma levels of leptin.Öğe Serum leptin levels in asthmatic children treated with an inhaled corticosteroid(Amer Coll Allergy Asthma Immunology, 2004) Gurkan, F; Atamer, Y; Ece, A; Kocyigit, Y; Tuzun, H; Mete, NBackground: Recent observations suggest the presence of an interaction between leptin and the inflammatory system; however, there is no adequate knowledge about the role of leptin in atopic states such as asthma. Objectives: To evaluate the potential role of leptin in relation to bronchial asthma and inhaled corticosteroid therapy. Methods: Twenty-three children with mild-to-moderate, newly diagnosed asthma enrolled in this 2-period trial. The control group consisted of 20 age- and sex-matched children. Serum leptin levels were measured in patients at initiation and after 4 weeks of budesonide treatment and were compared with control group measurements. Results: Asthmatic children had higher mean +/- SD serum leptin levels at admission (19.3 +/- 5.1 ng/mL) than after budesonide treatment (10.6 +/- 1.6 ng/mL) and vs control group measurements (9.8 +/- 1.6 ng/mL) (P < .001). There was a significant correlation between serum leptin levels before and after budesonide treatment (r = 0.68; P = .007). Mean +/- SD body mass indices in patients and controls were 16.7 +/- 2.1 and 16.9 +/- 2.6 kg/m(2), respectively. Serum leptin levels did not correlate with body mass indices before budesonide treatment in the study group (r = -0.13; P = .65) but correlated well after budesonide treatment (r = 0.58; P = .009) and in the control group (r = 0.65; P = .008). Conclusions: The role of leptin elevation in children with asthma might be a regulatory mechanism rather than being etiologic, but a question may be raised whether it is possible that leptin may contribute to poor patient outcomes. Further research, both basic and clinical, is essential to explain the exact mechanism.Öğe Serum levels of leptin, insulin-like growth factor-I and insulin-like growth factor binding protein-3 in women with pre-eclampsia, and their relationship to insulin resistance(Parthenon Publishing Group, 2004) Kocyigit, Y; Bayhan, G; Atamer, A; Atamer, YThe present study was carried out to compare serum levels of leptin, insulin-like growth factor- I (IGF-I), insulin-like growth factor binding protein-3 (IGFBP-3), homeostasis model assessment-(pancreatic beta-cell function) (HOMA-(%B)) and homeostasis model assessment-(tissue insulin sensitivity) (HOMA-(%S)) in women with mild and severe pre-eclampsia and normotensive pregnant women; and to evaluate the possible relationships between these Parameters in the pathogenesis of pre-eclampsia. Seventy-three women were divided into three groups: group A consisted of 20 normotensive pregnant women (NPW); group B consisted of 25 women with mild pre-eclampsia (MPE); and group C consisted of 28 women with severe pre-eclampsia (SPE). Serum level of leptin was measured by enzyme immunoassay using a commercial kit. Serum levels of IGF-I and IGFBP-3 were measured with a two-site immunoradiometric assay. Serum level of insulin was measured by the electrochemiluminescence immunoassay method. HOMA used indices of pancreatic beta-cell function and tissue insulin sensitivity. Differences between groups were compared by one-way analyses of variance and the post hoc Tukey-HSD test fir multiple comparisons; however, when a variable was not normally distributed, the Mann-Whitney U test was used. Associations between variables were tested using Pearson's coefficient of correlation. Birth weight was significantly lower (p < 0.001) in the MPE and SPE groups than in the NPW group. Serum levels of leptin and insulin in women with SPE and MPE were significantly higher (p < 0.001) than in NPW. Serum levels of IGF-I and IGFBP-3 were significantly lower in women with SPE and MPE compared with NPW (p < 0.001). The mean HOMA- (%B) level in women with SPE and MPF was significantly higher than in NPW (p < 0.001), whereas the mean HOMA-(%S) level in women with SPE and MPF was significantly lower than in NPW (p < 0.001). In the SPE group, systolic blood pressure correlated significantly with serum levels of IGF-I and leptin (r = 0.375, p < 0.05 and r = 0.495, p < 0.01, respectively). A negative correlation between, mean HOMA-(%S) level and serum IGFBP-3 level was noted (r =-0.357, p < 0.05). There was a positive correlation between serum level of IGF-I and mean HOMA-(%B) level in mildly pre-eclamptic women (r = 0.541, p < 0.01). We conclude that pre-eclampsia is associated with insulin resistance; and that existing hyperinsulinemia and insulin resistance in women with pre-eclampsia seem not to correlate with leptin and birth weight, but may correlate positively with IGF-I and IGFBP-3. Therefore we think that hyperleptinemia, low IGF-I or IGFBP-3, and insulin resistance may contribute to the pathogenesis of pre-eclampsia.
