Biomedical subjects

Hakim Celik

Publications and source records attributed to Hakim Celik.

17 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

Increased DNA damage and oxidative stress in patients with rheumatoid arthritis.

OBJECTIVES: Oxidative stress has been described as an important mechanism that underlies chronic inflammation in rheumatoid arthritis (RA). The aim of the study was to investigate the peripheral DNA damage, total antioxidant status (TAS), and total oxidative status (TOS) in patients with RA. DESIGN AND METHODS: The study population contained 25 patients with RA and 26 healthy controls. DNA damage was assessed by alkaline comet assay in peripheral lymphocyte, plasma levels of total antioxidant status (TAS) and total oxidative status (TOS) were determined, and OSI was calculated using a novel automated measurement method. Disease activity was evaluated by DAS-28 score. RESULTS: In RA patients, DNA damage was significantly higher than in controls (20.0+/-9.6 AU, 7.6+/-4.3 AU; p<0.001). Plasma TOS and OSI were higher in patients than in healthy controls (9.9+/-2.6 vs. 7.3+/-1.1, p<0.001; 1.04+/-0.4 vs. 0.7+/-0.1, p<0.001, respectively). Plasma TAS level in patients was lower than in healthy controls (0.9+/-0.7 vs. 1.01+/-0.7, p<0.001). DNA damage was correlated with TOS, OSI, and DAS-28 scores (r=0.682, p<0.001; r=0.753, p<0.001; r=0.519, p=0.008, respectively). CONCLUSIONS: The findings indicated that lymphocyte DNA damage level increases in patients with RA. Elevated DNA damage may be related with increased oxidative stress and decreased antioxidant capacity. However, the mechanism of this association, and whether it is direct or indirect, remains to be explored.

Adult↗

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

No increase in sperm DNA damage and seminal oxidative stress in patients with idiopathic infertility.

The most common cause of male infertility is idiopathic. Standard investigations reveal no abnormality in such cases. The aim of the study was to investigate the levels of sperm DNA damage and seminal oxidative stress and their relationships with idiopathic infertility. The study included 30 normozoospermic infertile men seeking infertility treatment and 20 fertile donors. Semen analysis was performed according to the World Health Organization guidelines. Sperm DNA damage was assessed by alkaline single cell gel electrophoresis (comet assay) after preparation with two-step discontinuous Percoll gradient. Seminal oxidative stress was measured by a novel automated method. DNA damage score, total antioxidant status (TAS), total oxidant status (TOS) and oxidative stress index (OSI) were not different in idiopathic infertile men compared with controls. No correlations were also found between DNA damage score and TAS, TOS levels and OSI in idiopathic infertile group. We did not find any relationship between sperm DNA damage and oxidative stress in normozoospermic infertile men. We think that the pathophysiology of idiopathic infertility cannot be explained by sperm DNA damage or seminal oxidative stress.

Comet Assay↗

PubMed2006

Does instant coffee prevent acute liver injury induced by carbon tetrachloride (CCl(4))?

OBJECTIVE: To investigate the protective effect of instant coffee (IC) on acute liver injury induced by CCl(4). METHODS: The study included 32 rats which were allocated to four groups: control (n: 8), CCl(4) (n: 8), CCl(4)+IC (n: 8) and IC (n: 8). Malondialdehyde, which is a lipid peroxidation product, and levels of antioxidant capacity were measured and histopathological data were compared. RESULTS: It was seen in the study that lipid peroxidation products that increased in the plasma and liver tissue of the CCl(4) group decreased by IC administration. There was an increase in the measured antioxidant parameters, which were total antioxidant capacity (TAOC), sulphydryl (SH) and ceruloplasmin levels. Histopathologically, it was found that inflammation and necrosis which increased in the group administered CCl(4) decreased significantly with IC administration, but there steatosis did not change. CONCLUSIONS: It was seen that IC had a protective role in acute liver injury induced by CCl(4), but did not affect steatosis.

Journal Article↗

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

Assessment of peripheral DNA damage by alkaline comet assay in maintenance hemodialysis subjects with hepatitis C infection.

Despite the high prevalence of hepatitis C infection among hemodialysis subjects, there is no information concerning the DNA damage of hepatitis C (+) hemodialysis subjects. We aimed to find out if there is any additional effect of hepatitis C infection on peripheral DNA damage in maintenance hemodialysis subjects. Fifteen hepatitis C (+) and 22 hepatitis C (-) hemodialysis subjects, 21 hepatitis C subjects without renal disease, and 22 healthy controls were enrolled. Peripheral DNA damage was assayed using alkaline comet assay. Median DNA damage levels of the study groups were as follows: hepatitis C (+) maintenance hemodialysis subjects, 88 (0-232); hepatitis C (-) maintenance hemodialysis subjects, 58 (0-228); hepatitis C (+) subjects without renal disease, 112 (44-252); controls, 26 (0-72). DNA damage level was significantly higher among hepatitis C (+) subjects without renal disease than hepatitis C (-) maintenance hemodialysis subjects and healthy controls (both p<0.05/6). Both maintenance hemodialysis subjects with and without HCV infection had significantly higher DNA damage level than healthy controls (both p<0.05/6). DNA damage level was comparable between hepatitis C (+) subjects without renal disease and HCV (+) hemodialysis subjects, and between hemodialysis subjects with and without hepatitis C infection (all p>0.05/6). Linear regression analysis revealed that hepatitis C infection was the only independent factor in predicting the peripheral DNA damage (p<0.05, beta=0.395). Each one of end-stage renal disease and hepatitis C infection significantly increases DNA damage level. However, in hemodialysis subjects, hepatitis C infection does not cause significant additional increase in DNA damage level, and it may be partly due to protective effect of hemodialysis on hepatitis C infection.

Adult↗

PubMed2006

Total antioxidant capacity and the severity of the pain in patients with fibromyalgia.

The purpose of the study was to determine the oxidative and antioxidative status of plasma in patients with fibromyalgia. Total antioxidant capacity (TAC) of plasma was significantly lower in patients with fibromyalgia (n = 20) than in healthy controls (n = 20) [1.5 (SD 0.3) and 1.9 (SD 0.3) mmol Trolox equiv./l, P = 0.001]. In contrast, the total peroxide level of plasma was significantly higher in patients than in healthy controls [37.4 (SD 6.7) and 33.0 (SD 2.7) micromol H2O2/l; P = 0.01]. The oxidative stress index (OSI) level was significantly higher in patients with fibromyalgia than in healthy controls [2.5 (SD 1.0) and 1.8 (SD 0.4); P = 0.007]. A significant negative correlation between visual analogue scale (VAS) and TAC level was determined (r = -0.79, P < 0.001). The present results indicate that patients with fibromyalgia are exposed to oxidative stress and this increased oxidative stress may play a role in the etiopathogenesis of the disease. Supplementation of antioxidant vitamins such as vitamins C and E to the therapy may be indicated.

Adult↗

PubMed2006

Effects of treadmill exercise test on oxidative/antioxidative parameters and DNA damage.

OBJECTIVE: We investigated the acute effects of treadmill exercise test (TET) on total peroxide, total antioxidant capacity (TAC), oxidative stress index (OSI) and DNA damage levels in voluntary and untrained healthy subjects. METHODS: A total of 113 untrained healthy subjects were included in the study. All subjects maintained a similar diet and physical activity for a week before the test. Blood samples were obtained before and after TET. Total peroxide, TAC, vitamin C and DNA damage were measured. The DNA damage was analyzed by using the Comet assay and OSI was calculated using total peroxide and TAC values. RESULTS: Treadmill exercise test leads to the increase of total peroxide (12 +/- 3 micromol H2O2/L to 14 +/- 3 micromol H2O2/L, p<0.001), OSI (0.72 +/- 0.18 AU to 0.81 +/- 0.22 AU, p<0.001), and to the decrease of TAC (1.78 +/- 0.16 mmol Trolox Eq./L to 1.72 +/- 0.15 mmol Trolox Eq./L, p<0.001) and vitamin C levels (98 +/- 4.2 micromol/L to 95 +/- 3.4 micromol/L, p<0.001). There was not significant difference in DNA damage. CONCLUSION: Our findings demonstrate that TET increases oxidants, decreases TAC and vitamin C namely, the balance shift towards oxidative side, but this stress is not enough to produce DNA damage.

Antioxidants↗

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↗

PubMed2005

Increased oxidative stress associated with the severity of the liver disease in various forms of hepatitis B virus infection.

BACKGROUND: Oxidative stress can be defined as an increase in oxidants and/or a decrease in antioxidant capacity. There is limited information about the oxidative status in subjects with hepatitis B virus infection. We aimed to evaluate the oxidative status in patients with various clinical forms of chronic hepatitis B infection. METHODS: Seventy-six patients with hepatitis B virus infection, in whom 33 with chronic hepatitis, 31 inactive carriers and 12 with cirrhosis, and 16 healthy subjects were enrolled. Total antioxidant response and total peroxide level measurement, and calculation of oxidative stress index were performed in all participants. RESULTS: Total antioxidant response was significantly lower in cirrhotics than inactive HbsAg carriers and controls (p = 0.008 and p = 0.008, respectively). Total peroxide level and oxidative stress index was significantly higher in cirrhotic (p < 0.001, both) and chronic hepatitis B subjects (p < 0.001, both) than inactive HbsAg carriers and controls. Total antioxidant response was comparable in chronic hepatitis B subjects, inactive HbsAg carriers and controls (both, p > 0.05/6). Total peroxide level and oxidative stress index were also comparable in inactive HBsAg carriers and controls (both, p > 0.05/6). Serum alanine amino transferase level was positively correlated with total peroxide level and oxidative stress index only in chronic hepatitis B subjects (p = 0.002, r = 0.519 and p = 0.008, r = 0.453, respectively). CONCLUSION: Oxidative stress occurs secondarily to increased total lipid peroxidation and inadequate total antioxidant response and is related to severity of the disease and replication status of virus in hepatitis B infection.

Adult↗

PubMed2005

Increased DNA damage and oxidative stress in patients with cutaneous leishmaniasis.

Cutaneous leishmaniasis (CL) is a chronic infectious and granulomatous disease caused by the Leishmania parasite that invades the skin. Reactive oxygen and nitrogen species (ROS and RNS) produced during an inflammatory response are an important part of host-defense strategies of organisms to kill the parasite. However, it is not well known whether these intermediates cause DNA damage in CL patients. We investigated the effect of Leishmania infection on basal levels of DNA strand breaks and on the oxidative/anti-oxidative status of patients with CL, and compared the data with those of healthy subjects. Twenty-five CL patients and 19 age- and sex-matched control subjects were enrolled in the study. We used the single-cell gel electrophoresis (also called comet assay) to measure DNA strand breaks in peripheral blood mononuclear leukocytes. Plasma protein carbonyl (PC), malondialdehyde (MDA) and total peroxide (TP) concentrations were measured to determine oxidative status and total anti-oxidative response (TAR) in plasma was measured to determine anti-oxidative status. The mean values of DNA damage and MDA and TP concentrations were significantly higher in CL patients than in the control group (p<0.001, p<0.01 and p<0.001, respectively). PC levels were also higher in patients, but this was not statistically significant (p>0.05). There was a significantly positive correlation between plasma MDA and DNA damage (r=0.524, p<0.01), and a negative correlation between TAR and TP levels (r=-0.790, p<0.001) in the patient group. These findings support the notion that ROS and RNS produced by the organism as a defense strategy may amplify the leishmanicidal activity in patients with CL. However, these intermediates not only cause the killing of the parasite but also induce oxidative damage in non-infected cells. Therefore, these patients must be treated urgently to counteract the oxidative DNA damage.

Adolescent↗

PubMed2005

Lymphocyte DNA damage in patients with acute coronary syndrome and its relationship with severity of acute coronary syndrome.

OBJECTIVE: The aim of this study was to investigate the association between lymphocyte DNA damage and acute coronary syndromes (ACS). METHODS: The study population contained 53 patients with ACS, 48 patients with stable angina and 35 voluntary healty subjects. DNA damage was assessed by alkaline comed assay in peripheral lymphocyte and plasma levels of total antioxidant capacity (TAC) were determined using a novel automated measurement method. RESULTS: In ACS patients, DNA damage was significantly higher than in patients with stable angina and control subjects (144+/-52 AU, 116+/-37, 68+/-34 AU; for three p<0.001, respectively). The TAC levels in patients with ACS were lower than the other groups (1.24+/-0.31 mmol Trolox equiv./l, 1.46+/-0.29 mmol Trolox equiv./l, p<0.05, respectively). DNA damage values in patients with acute miyocardial infarction were significantly higher than in patients with unstable angina (159.8+/-53.0 AU versus 131.8+/-48.4 AU; p<0.05, respectively). Lymphocyte DNA damage values in patients with ACS showed positive correlation with d-dimer (r=0.880, p<0.001) troponin I (r=538, p<0.001) and C-reactive protein (r=0.544, p<0.001) and negative correlation with TAC (r=-0.346, p=0.011). In multiple linear regression analysis, TAC (beta=-0.213, p=0.001) and d-dimer (beta=0.697, p<0.001) were independent predictors of DNA damage in patients with ACS. CONCLUSIONS: These findings indicate that lymphocyte DNA damage level increases in patients with ACS. Elevated DNA damage may be related with plaque instability and be useful for the identification of patients with acute coronary syndromes.

Adult↗