Gulden Baskol

Serum Paraoxonase 1 Activity and Lipid Peroxidation Levels in Patients with Age-Related Macular Degeneration

Our objective was to investigate antioxidant paraoxonase 1 (PON1) activity together with malondialdehyde (MDA) levels to evaluate oxidative stress in patients with age-related macular degeneration (AMD), an important cause of blindness in the elderly population. Serum PON1 activity and MDA levels were analyzed in 37 patients with AMD and compared with 29 healthy controls using a spectrophotometric method. Serum MDA levels were significantly higher in the patient group (2.76 ± 1.28 nmol/ml) than controls (1.00 ± 0.36 nmol/ml; p < 0.001), whereas PON1 activity was lower in the patient group (132.27 ± 63.39 U/l) than controls (312.13 ± 136.23 U/l; p < 0.001). There was a negative correlation between MDA and PON1 levels (r = –0.470, p < 0.001). We conclude that the observed increase in MDA levels may be related to decreased PON1 activity; the present data also demonstrated that an obvious negative correlation between PON1 activity and MDA levels exists in patients with AMD. PON1 is also an antioxidant agent, therefore effective antioxidant therapy to inhibit lipid peroxidation is necessary and agents to increase PON1 activity may be a therapeutic option in AMD.

Assessment of nitric oxide, advanced oxidation protein products, malondialdehyde, and thiol levels in patients with restless legs syndrome

OBJECTIVES We aimed to determine the importance of oxidative stress in the pathogenesis of restless legs syndrome (RLS) by quantification of advanced oxidation protein products and total thiol levels (as markers of oxidative protein damage), nitric oxide levels (as an antioxidant and endothelial function), and malondialdehyde levels (as a marker of lipid peroxidation) in patients with RLS. DESIGN AND METHODS A total of 22 patients with primary RLS were enrolled in the study and 20 age-and-gender-matched healthy subjects were enrolled as a control group. Serum nitric oxide, malondialdehyde, thiol levels, and plasma advanced oxidation protein products levels were determined by spectrophotometric methods. RESULTS Serum nitric oxide and thiol levels were lower in the patient group than in controls (p = 0.007 and p = 0.017, respectively). Plasma advanced oxidation protein products levels and serum malondialdehyde levels were found to be higher in patients with RLS than in controls (p = 0.017 and p = 0.008, respectively). Serum malondialdehyde level was found to be positively correlated with plasma advanced oxidation protein products levels (p = 0.039). Serum thiol level was found to be negatively correlated with plasma advanced oxidation protein products levels (p = 0.030). CONCLUSIONS Increased advanced oxidation protein products, malondialdehyde levels, and decreased thiol and nitric oxide levels, may suggest that patients with RLS are under oxidative stress. Although both lipid peroxidation and protein oxidation may have a role in atherosclerosis in RLS, those factors may be related to the pathogenesis of RLS.

Advanced Oxidation Protein Products : A Novel Marker of Oxidative Stress in Ulcerative Colitis

Background/Goals The etiology and pathogenesis of chronic inflammatory bowel diseases are still poorly understood. Oxidative stress takes place in the pathogenesis of ulcerative colitis (UC) and advanced oxidation protein products (AOPP) are accepted as a novel marker of oxidative stress. There are no data concerning whether AOPP may be used as a simple serum marker to assess the disease activity, predict severity of the disease course in UC. Study In this study, we determine the importance of neutrophil activation and the role of oxidative stress in the pathogenesis of UC, by quantification of AOPP and total thiol levels as markers of oxidative protein damage, malondialdehyde levels as a marker of lipid peroxidation, and myeloperoxidase activity as a marker of neutrophil activation in patients with UC. Results Serum levels of AOPP, thiol, myeloperoxidase activity, and malondialdehyde were found as increased in UC group compared with controls (P=0.004, 0.047, 0.001, and 0.001 respectively). Conclusions Our finding of increased levels of plasma AOPP levels supports the presence of oxidative stress and protein oxidation in UC and this marker may be used as a simple serum marker to assess disease activity, predict the severity of disease course, and perhaps response to therapy.

Micronucleus frequency in lymphocytes and 8-hydroxydeoxyguanosine level in plasma of women with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) has recently been linked with genomic instability and DNA damage. The aim of this study was to test genomic damage in women PCOS, using two different methods for assessing damage in both chromosome and base level. The study was performed on 36 newly diagnosed women with PCOS and 29 healthy women as controls. The micronucleus (MN) analysis used as a biomarker of chromosomal/DNA damage was performed in peripheral lymphocytes by cytokinesis-block method. 8-hydroxydeoxyguanosine (8-OHdG) levels used as a reliable marker of oxidative DNA damage were measured in plasma using an ELISA kit. We found that MN frequencies obtained from lymphocytes of the women with PCOS were significantly higher than those of controls (4.1 ± 1.0 vs. 2.1 ± 0.6, P = 0.001), whereas, no differences in 8-OHdG level were found between the patients with PCOS and controls (0.5 ± 0.3 vs. 0.5 ± 0.2, P = 0.858). These findings indicate that women with PCOS seem to have increased genomic instability, but do not appear to have oxidative DNA damage despite the increased oxidative stress associated with PCOS.

The role of serum zinc and other factors on the prevalence of muscle cramps in non-alcoholic cirrhotic patients

Background/Aims: To determine the prevalence of muscle cramps in patients with liver cirrhosis and to identify factors associated with their development, especially serum zinc. Method: One hundred cirrhotic patients and 85 healthy subjects were enrolled into the study. True muscle cramp was defined as at least 1 painful leg cramp either occurring at rest or strong enough to waken a patient from sleep, occurring at least once a week persisting for a period of greater than 1 year. Creatinine, calcium, magnesium, sodium, potassium, zinc, glucose, alanine aminotransferase, total bilirubin, and albumin levels were detected in sera. Prothrombine time was measured in cirrhotic patients. Presence or absence of ascite was determined by sonography. Results: True muscle cramps were significantly more common in patients with cirrhosis when compared with the control group (59% vs. 7.1%, respectively, P < 0.001). Cramp (+) cirrhotic patients had older age (49.54 ± 10.09 vs. 55.54 ± 7.90, respectively; p: 0.001) and higher Child-Pugh scores (7.56 ± 2.32 vs. 9.02 ± 2.55, respectively; p: 0.004) when compared with cramp (−) patients. None of the serum related factors such as creatinine, calcium, magnesium, sodium, potassium, zinc, glucose, alanine aminotransferase, total bilirubin, and albumin levels had any statistically significant contribution to the etiology. Conclusion: Muscle cramps are frequent complication of cirrhosis. Neither biochemical characteristics including decreased serum zinc levels nor the use of diuretics explained the greater prevalence of cramps in patients with cirrhosis. We conclude that the detrimental effect of cirrhosis on muscle fibers may be the major factor.

The role of advanced oxidation protein products and total thiols in diabetic retinopathy.

Purpose This study aimed to investigate the role of protein peroxidation by detecting the serum levels of advanced oxidation protein products (AOPP), a novel marker for the degree of oxidative damage to proteins, and total thiol as a marker of antioxidant status in diabetic patients with or without diabetic retinopathy (DR) and to compare the results with those of control subjects. Methods The study groups consisted of two separate subgroups: 1) 37 patients (14 male, 23 female) with noninsulin-dependent diabetes mellitus (NIDDM) showing diabetic retinopathy (DR) and 2) 20 patients with NIDDM and without any signs of DR (9 male, 11 female); 26 healthy non-diabetic control subjects (15 male, 11 female) were selected from the patients attending our department for refractive disorders. Venous blood samples of all participants were collected in the morning after an overnight fast, and serum samples stored at −70°C until assay for AOPP, and total thiol. Results AOPP levels were significantly higher in diabetic patients with (210.9±73.0 μmol/L) or without DR (222.7±94.4 μmol/L) when compared to those of controls (152.4±72.04 μmol/L) (p=0.004). Even though the difference was not statistically significant (p=0.095), total thiol levels in cases with DR (278.7±139.1 μmol/L) were lower than those without DR (334.0±129.4 μmol/L) and controls (353.2±145.6 μmol/L). Correlation tests did not reveal any association between these parameters and age, sex, or duration of DM. Conclusions The present study suggests that increased protein oxidation may contribute to the pathogenesis of DR.

Assessment of paraoxonase 1, xanthine oxidase and glutathione peroxidase activities, nitric oxide and thiol levels in women with polycystic ovary syndrome

Objective. To investigate whether there is any relation between oxidative stress and the antioxidant system in the development of polycystic ovary syndrome (PCOS) by measuring serum nitric oxide (NO) levels and xanthine oxidase (XO) activity (a generator of reactive oxygen species) and antioxidant status by measuring serum thiol levels and glutathione peroxidase (GSHPx) and paraoxonase 1 (PON1) activities. Design. Prospective case–control study. Setting. University hospital in Turkey. Sample. Thirty women with polycystic ovary syndrome and 20 age‐ and sex‐matched healthy control subjects were included. Methods. Serum XO, PON1 and GSHPx activity and NO and thiol levels were determined by spectrophotometric methods. Main outcome measures. Activity of serum XO, PON1 and GSH, as well as NO and thiol levels. Results. Serum XO activities were higher in women with PCOS than in the control women (p<0.001). The PON1 activity was lower in women with PCOS than in the control women (p<0.001). No significant difference was found between NO and thiol levels and GSHPx activities of women with PCOS and the control women (p>0.05). Serum PON1 activities were negatively correlated with serum XO activities and NO levels. Conclusion. Increased oxidant XO activity and decreased lipid antioxidant PON1 activity, along with the observed negative correlation between these parameters, suggests that women with PCOS are under oxidative stress and that there is XO‐mediated lipid peroxidation, which may be related to increased atherosclerosis seen in later life in such women.

Five days of ceftriaxone to treat culture negative neutrocytic ascites in cirrhotic patients.

The goal of this study is to establish whether 5 days of ceftriaxone treatment was sufficient to cure culture-negative neutrocytic ascites in cirrhotic patients. We studied 50 cirrhotic patients with culture-negative neutrocytic ascites. All were treated with ceftriaxone, 1.0 g IV, twice a day for 5 days. A control paracentesis was performed 48 hours after starting the therapy to assess response to the treatment. A total of 17 demographic, clinical, and laboratory variables were recorded in all cases on the day of diagnosis of CNNA. The mean age of the patients was 57.7 ± 13.2 years. Thirty-two patients were males and 18 females. The etiology of cirrhosis was hepatitis C virus in 20 patients (40%), hepatitis B virus in 16 patients (32%), cryptogenic in 13 patients (26%), and alcohol abuse in 1 patient (2%). Eighty percent of the patients were in Child–Pugh Class C. Resolution rate of culture-negative neutrocytic ascites on day 5 of treatment was 78%. Hospital mortality in cirrhotic patients with culture negative neutrocytic ascites was 4%. Statistical analysis showed that none of the 13 selected variables as covariates significantly related with the resolution of culture-negative neutrocytic ascites. Five days of ceftriaxone treatment is an adequate therapy for culture-negative neutrocytic ascites.

Changes in Central Corneal Thickness, Intraocular Pressure, and Oxidation/Antioxidation Parameters at High Altitude

BACKGROUND The authors aimed at investigating ophthalmological changes at high altitude and correlating this with blood oxidation/antioxidation parameters. METHODS There were 40 volunteers who participated in the study. Initial ophthalmological examinations were performed at 3543 ft (1080 m) and repeated on the following day after the participants climbed to an altitude of 9186 ft (2800 m) on Mt. Erciyes, Turkey. Venous blood samples were taken at both altitudes to evaluate total oxidative system (TOS) and antioxidative system (TAS) levels. RESULTS IOP-right eyes at 3543 ft (1080 m) was 13.23 +/- 0.43 mmHg and significantly increased to 14.45 +/- 0.56 mmHg at 9186 ft (2800 m). LOP-left eyes at 3543 ft (1080 m) was 13.50 +/- 0.44 mmHg and increased to 14.13 +/- 0.54 mmHg at 9186 ft (2800 m) (P = n.s.). Central corneal thickness (CCT) of the right eyes was 540.98 +/- 4.34 microm at 3543 ft (1080 m) and significantly increased to 549.73 +/- 4.59 microm at 9186 ft (2800 m). CCT of the left eyes was 542.13 +/- 29.01 microm at 3543 ft (1080 m) and significantly increased to 547.23 +/- 4.59 microm at 9186 ft (2800 m). Spherical equivalent refraction of right or left eyes did not show any significant changes. TOS at 3543 ft (1080 m) was 5.33 +/- 0.76 micromol H2O2 equiv/L and significantly increased to 7.55 +/- 0.82 micromol H2O2 equiv/L at 9186 ft (2800 m). TAS at 3543 ft (1080 m) was 2.45 +/- 0.12 micromol H2O2 equiv/L and decreased to 2.22 +/- 0.08 micromol H2O2 equiv/L (P = n.s.) at 9186 ft (2800 m). There was a positive correlation between TAS and LOP at 9186 ft (2800 m). CONCLUSION Increased CCT can be related to stromal edema caused by hypoxias effect on corneal endothelial function. Although TOS increased at high altitude, TAS did not show any parallel increase. Since this was nonacclimatized climbing, the antioxidant system could not have reached sufficient levels to counterbalance the observed oxidant stress.

Increased Chromosomal and Oxidative DNA Damage in Patients with Multinodular Goiter and Their Association with Cancer

Thyroid nodules are a common clinical problem worldwide. Although thyroid cancer accounts for a small percentage of thyroid nodules, the majority are benign. 8-Hydroxy-2′-deoxyguanosine (8-OHdG) levels are a marker of oxidative stress and play a key role in the initiation and development of a range of diseases and cancer types. This study evaluates cytokinesis-block micronucleus cytome (CBMN-cyt) assay parameters and plasma 8-OHdG levels and their association with thyroid nodule size and thyroid hormones in patients with multinodular goiter. The study included 32 patients with multinodular goiter and 18 age- and sex-matched healthy controls. CBMN-cyt assay parameters in peripheral blood lymphocytes of patients with multinodular goiter and controls were evaluated, and plasma 8-OHdG levels were measured. The micronucleus (MN) frequency (chromosomal DNA damage), apoptotic and necrotic cells (cytotoxicity), and plasma 8-OHdG levels (oxidative DNA damage) were significantly higher among patients with multinodular goiter. Our study is the first report of increased chromosomal and oxidative DNA damage in patients with multinodular goiter, which may predict an increased risk of thyroid cancer in these patients. MN frequency and plasma 8-OHdG levels may be markers of the carcinogenic potential of multinodular goiters and could be used for early detection of different cancer types, including thyroid cancer.