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Biomedical subjects

Ozcan Erel

Publications and source records attributed to Ozcan Erel.

At least 19 recordsLinked to original sources
PubMed2006

Serum paraoxonase-1 activity in Helicobacter pylori infected subjects.

Previous studies have suggested that Helicobacter pylori (H. pylori) infection may play an important role in the process of atherosclerosis. The objective of this study was to investigate serum paraoxonase and arylesterase activities, and lipid hydroperoxide (LOOH) and total thiol (SH) levels along with lipid parameters in H. pylori infected subjects. Fifty-six H. pylori positive subjects and 43 H. pylori negative subjects were enrolled. Serum paraoxonase and arylesterase activities were measured spectrophotometrically. LOOH levels were measured by FOX-2 assay. Serum SH levels, paraoxonase and arylesterase activities were significantly lower in H. pylori positive group than H. pylori negative group (all p<0.05), while LOOH levels were significantly higher (p<0.05). In H. pylori positive subjects, serum LOOH levels were correlated with SH levels (r=-0.247, p<0.05), serum paraoxonase (r=-0.432, p<0.05) and arylesterase activities (r=-0.404, p<0.001), and triglyceride (r=0.305, p<0.05), total cholesterol (r=0.568, p<0.05), high-density lipoprotein-cholesterol (HDL-C) (r=-0.300, p<0.05) and low-density lipoprotein-cholesterol (LDL-C) (r=0.577, p<0.05) levels. Serum paraoxonase and arylesterase activities were also correlated with HDL-C levels (r=0.221, p<0.05 and r=0.291, p<0.05, respectively), while no correlation was observed with triglyceride, total cholesterol and LDL-C levels (both p>0.05). In conclusion, paraoxonase and arylesterase activities decrease significantly in H. pylori infected subjects. Lower serum paraoxonase-1 (PON1) activity seems to be related to decrease in HDL-C and, in part, to increased oxidative stress and inflammatory condition induced by H. pylori infection. Measurement of serum PON1 activity may help in the early identification of H. pylori infected subjects with increased risk of atherosclerotic disease.

Adult↗
PubMed2006

Insulin resistance in H pylori infection and its association with oxidative stress.

AIM: To determine the insulin resistance (IR) and oxidative status in H pylori infection and to find out if there is any relationship between these parameters and insulin resistance. METHODS: Fifty-five H pylori positive and 48 H pylori negative patients were enrolled. The homeostasis model assessment (HOMA) was used to assess insulin resistance. Serum total antioxidant capacity (TAC), total oxidant status (TOS) and oxidative stress index (OSI) were determined in all subjects. RESULTS: The total antioxidant capacity was significantly lower in H pylori positive group than in H pylori negative group (1.36 +/- 0.33 and 1.70 +/- 0.50, respectively; P < 0.001), while the total oxidant status and oxidative stress index were significantly higher in H pylori positive group than in H pylori negative group (6.79 +/- 3.40 and 5.08 +/- 0.95, and 5.42 +/- 3.40 and 3.10 +/- 0.92, respectively; P < 0.001). Insulin resistance was significantly higher in H pylori positive group than in H pylori negative group (6.92 +/- 3.86 and 3.61 +/- 1.67, respectively; P < 0.001). Insulin resistance was found to be significantly correlated with total antioxidant capacity (r = -0.251, P < 0.05), total oxidant status (r = 0.365, P < 0.05), and oxidative stress index (r = 0.267, P < 0.05). CONCLUSION: Insulin resistance seems to be associated with increased oxidative stress in H pylori infection. Further studies are needed to clarify the mechanisms underlying this association and elucidate the effect of adding antioxidant vitamins to H pylori eradication therapy on insulin resistance during H pylori infection.

Adult↗
PubMed2006

Increased oxidative stress and its relation with collagen metabolism in knee osteoarthritis.

The purpose of this study was to determine serum oxidative/antioxidative status in patients with knee osteoarthritis and its relation with prolidase activity, which plays an important role in collagen metabolism. Serum antioxidative status was evaluated by measuring total antioxidant capacity (TAC), thiol level and catalase enzyme activity in patients with osteoarthritis and in healthy controls. Serum oxidative status was evaluated by measuring total peroxide (TP) and lipid hydroperoxide. Oxidative stress index (OSI) was calculated. Prolidase enzyme activity was measured to investigate the collagen metabolism. Serum TAC, thiol level, catalase activity and prolidase activity were significantly lower in patients than in controls (P < 0.001, for all). In contrast, TP, lipid hydroperoxide and OSI values were significantly higher in patients than in controls (P < 0.001 for all). Further, prolidase activity was negatively correlated with TP and OSI, and positively correlated with TAC. The present results indicate that the oxidant parameters increased and antioxidant parameters decreased in patients with osteoarthritis; therefore, these patients may be exposed to a potent oxidative stress. Decreased collagen metabolism may be related with oxidative stress, which has a role in the ethiopathogenesis and/or in the progression of the disease.

Antioxidants↗
PubMed2006

Paraoxonase-1 activity as a marker of atherosclerosis is not associated with low bone mineral density in healthy postmenopausal women.

The aging process is associated with an increasing prevalence of osteoporosis and atherosclerosis, but it is uncertain if these two conditions are interrelated. Serum paraoxonase-1 (PON1) is a high-density lipoprotein (HDL) associated enzyme that has been implicated in the pathogenesis of atherosclerosis. Our aims of the study were to investigate (1) serum paraoxonase and arylesterase activities and, lipid hydroperoxide (LOOH) levels in healthy postmenopausal women and (2) whether there were any associations between these enzyme activities and bone mineral density (BMD). A total of 97 generally healthy postmenopausal women were enrolled in the study. BMD was measured at lumbar spine (LS) and femoral neck (FN) with dual energy X-ray absorptiometry. Serum paraoxonase and arylesterase activities were measured spectrophotometrically. LOOH levels were measured by iodometric assay. In this population, 50 (51%) women had BMD T scores < -2.5 at the LS and/or FN defined as osteoporosis and 47 (49%) of them had normal BMDs. Serum paraoxonase, arylesterase, and LOOH activities were not significantly different between osteoporotic and nonosteoporotic postmenopausal women. There were also no correlations between paraoxonase, arylesterase, LOOH activities, and LS BMD and FN BMD. We conclude that there may be not good evidence to support a direct relationship between osteoporosis and atherosclerosis in these subjects. However, prospective studies with larger groups are needed to investigate this issue further.

Absorptiometry, Photon↗
PubMed2006

Serum prolidase activity and oxidative status in Helicobacter pylori infection.

OBJECTIVES: During the course of Helicobacter pylori infection, increased oxidative stress plays an important role in the pathogenesis of gastroduodenal mucosal inflammation, which can cause gastric mucosal atrophy that characterized by the replacement of the gastric mucosal glands by collagen fibers. In the present study, we aimed to determine serum prolidase activity and oxidative status, and to find out if there is any association between serum prolidase activity and oxidative status in H. pylori infection. DESIGN AND METHODS: Forty H. pylori-positive and 32 H. pylori-negative subjects were enrolled. Serum prolidase activity was measured spectrophotometrically. Oxidative status was determined using total antioxidant capacity and total oxidant status measurement and calculation of oxidative stress index. RESULTS: Total antioxidant capacity level was lower in H. pylori-positive group than H. pylori-negative group (p<0.001), whereas total oxidant status, oxidative stress index and prolidase activity were higher (all p<0.05). Significant correlation was observed between serum prolidase activity, and total antioxidant capacity, total oxidant status and oxidative stress index (p<0.01, r=-0.367; p<0.05, r=0.283; p<0.01, r=0.379; respectively) in H. pylori-positive subjects. CONCLUSION: H. pylori infection may be associated with increased oxidative stress and increased serum prolidase activity. Increased oxidative stress seems to be associated with increased serum prolidase activity and this association may help to provide a better understanding about the pathogenesis of H. pylori infection.

Adult↗
PubMed2006

Lymphocyte DNA damage and oxidative stress in patients with iron deficiency anemia.

Oxidant stress has been shown to play an important role in the pathogenesis of iron deficiency anemia. The aim of this study was to investigate the association between lymphocyte DNA damage, total antioxidant capacity and the degree of anemia in patients with iron deficiency anemia. Twenty-two female with iron deficiency anemia and 22 healthy females were enrolled in the study. Peripheral DNA damage was assessed using alkaline comet assay and plasma total antioxidant capacity was determined using an automated measurement method. Lymphocyte DNA damage of patients with iron deficiency anemia was significantly higher than controls (p<0.05), while total antioxidant capacity was significantly lower (p<0.001). While there was a positive correlation between total antioxidant capacity and hemoglobin levels (r=0.706, p<0.001), both total antioxidant capacity and hemoglobin levels were negatively correlated with DNA damage (r=-0.330, p<0.05 and r=-0.323, p<0.05, respectively). In conclusion, both oxidative stress and DNA damage are increased in IDA patients. Increased oxidative stress seems as an important factor that inducing DNA damage in those IDA patients. The relationships of oxidative stress and DNA damage with the severity of anemia suggest that both oxidative stress and DNA damage may, in part, have a role in the pathogenesis of IDA.

Adult↗
PubMed2006

Oxidative stress in hepatitis C infected end-stage renal disease subjects.

BACKGROUND: Both uremia and hepatitis C infection is associated with increased oxidative stress. In the present study, we aimed to find out whether hepatitis C infection has any impact on oxidative stress in hemodialysis subjects. METHODS: Sixteen hepatitis C (+) hemodialysis subjects, 24 hepatitis C negative hemodialysis subjects and 24 healthy subjects were included. Total antioxidant capacity, total peroxide level and oxidative stress index were determined in all subjects. RESULTS: Total antioxidant capacity was significantly higher in controls than hemodialysis subjects with or without hepatitis C infection (all p < 0.05/3), while total peroxide level and oxidative stress index were significantly lower (all p < 0.05/3). Hepatitis C (-) hemodialysis subjects had higher total antioxidant capacity compared to hepatitis C (+) hemodialysis subjects (all p < 0.05/3). Total peroxide level and oxidative stress index was comparable between hemodialysis subjects with or without hepatitis C infection (p > 0.05/3). CONCLUSION: Oxidative stress is increased in both hepatitis C (+) and hepatitis C (-) hemodialysis subjects. However, hepatitis C infection seems to not cause any additional increase in oxidative stress in hemodialysis subjects and it may be partly due to protective effect of dialysis treatment on hepatitis C infection.

Adult↗
PubMed2006

Influence of oxidative stress on the development of collateral circulation in total coronary occlusions.

OBJECTIVES: The purpose of this study was to investigate whether the levels of total antioxidant capacity (TAC), total peroxide and oxidative stress index (OSI) are associated with the development of collaterals in total coronary occlusions. DESIGN AND METHODS: Our study group contained 176 consecutive men patients with single-vessel TCO, 94 of whom had poorly developed coronary collateral, while 82 had well-developed coronary collateral. TAC and total peroxide concentration were measured of plasma. The ratio of TAC to total peroxide was accepted as an indicator of oxidative stress. RESULTS: The values of total peroxide and OSI in the Group I were significantly lower than that in Group II (p<0.001, for both). TAC levels were significantly higher in patients with poorly developed collaterals than in well-developed collateral group (p<0.001). OSI values were also significantly different among the Rentrop class-0, -1, -2 and -3 (ANOVA p<0.001). We found significant correlations between collaterals score and TAC, total peroxide and OSI levels (p<0.001 for all). In multiple linear regression analysis, total peroxide and OSI were independent predictors of collaterals score (p=0.006 and p<0.001 respectively). CONCLUSION: This study clearly demonstrates that the level of OSI is independently and positively associated with the presence of collateral circulation in total coronary occlusion patients.

Antioxidants↗
PubMed2006

Assessment of paraoxonase and arylesterase activities in patients with iron deficiency anemia.

Paraoxonase-1 (PON1) is a high-density lipoprotein (HDL) associated enzyme with three activities which are paraoxonase, arylesterase and dyazoxonase. We aimed to determine serum (a) paraoxonase and arylesterase activities and, lipid hydroperoxide (LOOH) levels in patients with iron deficiency anemia (IDA) (b) whether there is an association between the development of atherosclerosis and paraoxonase/arylesterase activities in patients with IDA. Twenty-five female with IDA and 22 healthy female as control were enrolled in the study. Serum basal/salt-stimulated paraoxonase and arylesterase activities were measured spectrophotometrically. LOOH levels were measured by ferrous oxidation with xylenol orange assay. Basal/salt-stimulated paraoxonase and arylesterase activities were significantly lower in patients with IDA than controls (p<0.001; for all), while LOOH levels were significantly higher (p<0.001). Our results show that paraoxonase and arylesterase activities, which have antiatherogenic capability, are decreased in patients with IDA. Reduced paraoxonase and arylesterase activities may play a role in pathogenesis of atherosclerosis through increased susceptibility to lipid peroxidation in patients with IDA.

Adult↗
PubMed2006

Breast milk provides better antioxidant power than does formula.

OBJECTIVE: We examined the effect of breast milk on plasma total antioxidant capacity (TAC), total peroxide (TP), and oxidative stress index (OSI), which are biomarkers of oxidative status. METHODS: Fifty-four healthy term infants 3 to 6 mo of age were fed breast milk or a cow's milk modified formula. Plasma TAC, vitamin C, albumin, bilirubin, and uric acid levels were measured as indexes of antioxidative markers. Plasma TP levels were measured as an oxidative stress marker. The OSI was calculated to assess oxidative status. RESULTS: No significant differences were observed between groups with respect to growth or anthropometric measurements. Plasma uric acid, total protein, and albumin concentrations were slightly higher in the breast-fed group than in the formula-fed group. There was a positive correlation between infant's age and serum albumin levels; between TAC and plasma uric acid, albumin, and total bilirubin; and between plasma iron and TP levels in both groups (r > 0.256, P < 0.05). In addition, there was a negative correlation between plasma iron and TAC (r = -0.267, P = 0.01). Plasma TAC and vitamin C levels were significantly higher in the breast-fed group than in the formula-fed group (P < 0.05). Plasma TP levels and the OSI were higher in the formula-fed group than those in the breast-fed group (P < 0.05). CONCLUSIONS: Our data suggest that breast milk provides better antioxidant power than does formula.

Antioxidants↗
PubMed2006

High frequency of maternal vitamin B12 deficiency as an important cause of infantile vitamin B12 deficiency in Sanliurfa province of Turkey.

BACKGROUND: Vitamin B12 deficiency in infancy may cause failure to thrive, severe neurological disorders and megaloblastic pancytopenia. It is well known that infants born with deficient vitamin B12 storage have increased the risk of vitamin B12 deficiency. Vitamin B12 deficiency is more prevalent in infancy in Sanliurfa province (at the southeast region of Turkey). AIM OF THE STUDY: The aim of this study was to determine the frequencies of vitamin B12, folic acid and iron deficiencies in pregnants and their babies at birth and to what extend the mothers' deficiency becomes effective on babies' deficiencies. METHODS: The study groups were constituted by 180 pregnant women and their single and term babies. Venous blood samples of pregnants were obtained 1-3 h before delivery and babies' cord bloods were collected at birth. Vitamin B12 and folic acid levels were measured with electro chemiluminiscence method; serum iron and iron binding capacities were measured by colorimetric method and complete blood counts were performed by automatic blood counter. RESULTS: Mean vitamin B12 levels in maternal and cord blood serum were 130 +/- 61.7 pg/ml and 207 +/- 141 pg/ml; mean folic acid levels were 8.91 +/- 6.46 ng/ml and 17.8 +/- 11.8 ng/ml; mean serum iron levels were 56.9 +/- 37.5 microg/dl and 147 +/- 43.2 microg/dl; and mean transferrin saturations were 11.8 +/- 8% and 65.6 +/- 24%, respectively. There were vitamin B12 deficiency (<160 pg/ml) in 72% of the mothers and 41% of the babies, and severe deficiency (<120 pg/ml) in 48% of the mothers and 23% of the babies. Folic acid deficiency was found in 12% of the mothers, but was not found in the babies. There were iron deficiency in 62% of the mothers and 1% of the babies. There were statistically significant correlation between maternal and cord blood serum vitamin B12 levels (r = 0.395, P < 0.001) and folic acid levels (r = 0.227, P = 0.017), while there were no correlation between maternal and cord blood iron levels and transferrin saturations. CONCLUSION: The study results showed that vitamin B12 deficiency is prevalent in pregnants in this region and that 41% of infants have born with deficient vitamin B12 storages. Therefore, prophylactic use of vitamin B12 by pregnant women in Sanliurfa and other poor communities could have considerable benefits to prevent vitamin B12 deficiency and its complications in infants.

Adult↗
PubMed2006

Total antioxidant/oxidant status in meningism and meningitis.

The objective of this study was to investigate the antioxidant/oxidant status of serum and cerebrospinal fluid in children with meningismus and acute bacterial meningitis. Twenty-three children (age range, 0.75 to 9 years) with fever and meningeal signs that required analysis of the cerebrospinal fluid, but no cytologic or biochemical evidence of meningitis in their serum and cerebrospinal fluid, constituted the meningismus group. Thirty-one children (age range, 0.5 to 10 years) with acute bacterial meningitis constituted the meningitis group. Twenty-nine healthy children (age range, 0.5 to 11 years) were recruited as control subjects. Antioxidant status (ascorbic acid, albumin, thiol, uric acid, total bilirubin, total antioxidant capacity, catalase and ceruloplasmin concentrations) and oxidant status (lipid hydroperoxide and total oxidant status) were measured. The serum antioxidant status was lower, and oxidant status levels higher in both meningitis and meningismus subjects than in the control children (P < 0.001). Cerebrospinal fluid oxidant status was lower in the meningitis group than in the meningismus group (P < 0.05). These results indicate that serum antioxidant status was lower, and serum oxidant status was higher in children in the meningismus and meningitis groups, whereas cerebrospinal fluid oxidant status was higher in the meningismus group than in the meningitis group.

Acute Disease↗
PubMed2006

Oxidative and antioxidative status in the testes of rats with acute epididymitis.

INTRODUCTION: Epididymitis is an inflammation or infection of the epididymis, a convoluted duct that lies on the posterior surface of the testicle. Oxidative stress due to excessive production of reactive oxygen species in epididymitis, impaired antioxidant defense mechanisms, or both, precipitates a range of pathologies that are currently believed to negatively affect the male reproductive function. How oxidative stress affects the testes is still unknown. We aimed to investigate the oxidative and antioxidative status of testes of rats with unilateral acute Escherichia coli epididymitis. METHODS: The study included 36 male Wistar albino rats which were divided into three groups. In the epididymitis group (n = 12), an E. coli suspension was injected into the right ductus deferens of rats, and the same amount of saline was injected in the saline groups (n = 12). No surgery was performed in the control group (n = 12) for baseline values. Rats were sacrificed after 24 h and the epididymis and testes removed. The infection was confirmed by histopathologic evaluation and microbiological tests. The oxidative status of testes was evaluated by measuring myeloperoxidase (MPO) activity, and antioxidative status was evaluated by measuring total antioxidant response (TAR) and total antioxidant capacity levels (TAC). RESULTS: MPO activity in both the ipsilateral and contralateral testes of the epididymitis group was significantly higher than those of the saline and control groups (p < 0.05). The TAR and TAC levels in both testes were also significantly elevated in the epididymitis group versus the two other groups (p < 0.05). CONCLUSIONS: Acute epididymitis causes an increase of oxidative stress in the ipsilateral and contralateral testes, but this condition is strived for to tolerate the increase of endogenous antioxidants.

Acute Disease↗
PubMed2006

Decrease of total antioxidant capacity during coronary artery bypass surgery.

OBJECTIVE: Cardiac surgery induces an oxidative stress, which may lead to impairment of cardiac function. In this study, we aimed to measure the changes of oxidative and antioxidative status of patients undergoing coronary artery bypass surgery (CABG). MATERIALS AND METHODS: We studied 79 patients who underwent CABG with and without cardiopulmonary bypass (CPB). Of the 79 patients, 39 had CPB and 40 did not. Blood samples were drawn before, during, and after the surgery. Antioxidant status was evaluated by measuring total antioxidant capacity (TAC), and oxidative status was evaluated by measuring total peroxide (TP) levels and oxidative stress index (OSI). RESULTS: TP and OSI levels increased, while TAC decreased progressively after the beginning of surgery, for all patients. There were negative correlations between TAC levels and aortic cross-clamping period and anastomosis time ( r = -0.553, p < 0.001 and r = -0.500, p < 0.001, respectively). In addition, there was a positive correlation between TAC and ejection fraction (r = 0.647, p < 0.001). CONCLUSIONS: During CABG, oxidant and OSI levels significantly increase and TAC significantly decreases. This situation is influenced by long CPB and anastomosis time, and also by low ventricular ejection fraction. We concluded that the patients who undergo CABG are exposed to potent oxidative stress that impairs their TAC. We speculate that supplementation with antioxidant vitamins such as vitamins C and E may be beneficial for patients undergoing CABG.

Antioxidants↗