Atherosclerosis assessment and rheumatoid arthritis.

BACKGROUND AND AIM: Rheumatoid arthritis is associated with increased morbidity and mortality due to atherosclerotic cardiovascular diseases. Lipoprotein-associated phospholipase A2 (Lp-PLA2) is an enzyme of phospholipase A2; it plays an important role in inflammation and atherosclerosis. Herein we aimed to investigate whether Lp-PLA2 activity is associated with atherosclerosis in patients with rheumatoid arthritis and compare the Lp-PLA2 activity with carotid intima media thickness (CIMT). PATIENTS AND METHODS: 25 patients with rheumatoid arthritis and 40 controls (20 patients with type 2 diabetes mellitus [DM] and 20 healthy controls) were included in the study. Frozen serum samples were used for analyzing Lp-PLA2 activity. Disease activity was calculated with DAS28 (Disease Activity Score 28) in the rheumatoid arthritis group. The mean CIMT was calculated in all participants. RESULTS: Lp-PLA2 activity was significantly higher in the DM group (p = 0.006) and LDL (Low density cholesterol levels) were lower in rheumatoid arthritis and healthy control groups compared with diabetics (p = 0.001 and p = 0.029, respectively). The mean CIMT was significantly higher in patients with type 2 DM (p = 0.047). CONCLUSION: Lp-PLA2 activity was not increased in the rheumatoid arthritis group when compared with healthy controls and the DM group. This result may be associated with low disease activity scores in patients with rheumatoid arthritis.

Thyroid autoimmunity in patients with Familial Mediterranean Fever: preliminary results.

AIM: We investigated whether there was a significant increase in thyroid autoimmunity in patients with Familial Mediterranean fever (FMF). PATIENTS AND METHODS: In total, 220 patients, consisting of 42 with FMF, 75 with rheumatoid arthritis (RA), and 103 healthy controls, were enrolled. Serum thyroid-stimulating hormone (TSH), free triiodothyronine (fT3), free thyroxine (fT4), and thyroid autoantibodies (anti-thyroid peroxidase and anti-thyroglobulin) were measured in all participants. RESULTS: After adjustment for age, gender, and smoking status, statistically significant differences between serum levels of anti-thyroglobulin antibody, anti-thyroid peroxidase antibody, and fT3 were found between the groups (all p < 0.001). Serum TSH level did not differ between the groups (p > 0.05). The frequency of autoimmune thyroiditis in FMF group is higher than control group. However, this difference did not reached the level of statistical significance (p > 0.05). CONCLUSIONS: Although statistically not significant, thyroid autoimmunity was observed more frequently in patients with FMF than in healthy controls. Thyroid autoantibodies were significantly higher in patients with FMF. Studies with greater number of patients are required for evaluating the frequency of the autoimmune thyroiditis in patients with FMF.

Effect of exercise on appetite-regulating hormones in overweight women.

Over the past decade, our knowledge of how homeostatic systems regulate food intake and body weight has increased with the discovery of circulating peptides such as leptin, acyl ghrelin, des-acyl ghrelin and obestatin. These hormones regulate the appetite and food intake by sending signals to the brain regarding the body's nutritional status. The purpose of this study was to investigate the response of appetite-regulating hormones to exercise. Nine overweight women undertook two 2 h trials in a randomized crossover design. In the exercise trial, subjects ran for 60 min at 50% of maximal oxygen uptake followed by a 60 min rest period. In the control trial, subjects rested for 2 h. Obestatin, acyl ghrelin, des-acyl ghrelin and leptin concentrations were measured at baseline and at 20, 40, 60, 90 and 120 min after baseline. A two-way ANOVA revealed a significant (P < 0.05) interaction effect for leptin and acyl ghrelin. However, changes in obestatin and des-acyl ghrelin concentration were statistically insignificant (P > 0.05). The data indicated that although acute treadmill exercise resulted in a significant change in acyl ghrelin and leptin levels, it had no effect on plasma obestatin and des-acyl ghrelin levels.

Nitrite/nitrate and malondialdehyde levels in nasal polyp.

The aim of this study was to examine the pathophysiological role of NO (nitric oxide) and MDA (malondialdehyde) in tissue in patients with nasal polyposis. We measured nitrite/nitrate (Nitrite/Nitrate; NO2-/NO3-) and MDA in tissue and plasma of NP patients (n=20) and controls (n=20). MDA level expressed as the concentration of substances reacting to thiobarbituric acid and production of NO (concentration of nitrite/nitrate in plasma) by the Griess reaction were determined. The level of NO2- and NO3- in tissue are higher than that of the normal tissue (p<0.05). The level of MDA in tissue are higher than that of the normal tissue (p<0.05). The level of NO2- and NO3- in plasma of two groups are similar (p>0.05). The level of MDA in plasma is higher than that in the normal controls (p<0.05). The change in NO2-/NO3- and MDA levels of nasal polyp patients was demonstrated. Further studies are required concerning the significance of changes in lipid peroxidation and nitrite levels in pathogenesis of nasal polyp.

The effect of the sulfonylurea glyburide on glutathione-S-transferase and glucose-6-phosphate dehydrogenase in streptozotocin-induced diabetic rat liver.

Free radical-induced lipid peroxidation has been associated with numerous disease processes including diabetes mellitus. Glutathione-S-transferase (GST) catalyses the conjugation of glutathione with a variety of organic peroxides to form more water-soluble compounds. Glucose-6-phosphate dehydrogenase (G6PDH) is essential to control intracellular reductive potential by increasing glutathione intracellular levels, which in turn decrease the amount of reactive oxygen species. Glyburide decreases glucose production and enhances insulin action in liver. The aim of this study was to examine the effects of glyburide on the antioxidant enzyme activities in the liver tissue of diabetic rat. We investigated the activities of GST and G6PDH in the liver of both control and streptozotocin-induced diabetic rats. Forty male albino rats were included in this study. Liver GST and G6PDH activities decreased significantly in five-week diabetic rats (p<0.001 and p<0.001 respectively) compared to controls and glyburide therapy restored these activities (p<0.001 for GST and p<0.001 for G6PDH). Elevations of hepatic antioxidant enzymes with glyburide administration suggest that glyburide may directly alter hepatic enzyme activities.

The effects of the sulfonylurea glyburide on glutathione peroxidase, superoxide dismutase and catalase activities in the heart tissue of streptozotocin-induced diabetic rat.

Oxygen free radicals have been suggested to be a contributory factor in diabetes complications. The aim of this study was to examine the effects of glyburide on the antioxidant enzyme activities in the heart tissue of diabetic rats. We investigated the activities of antioxidant enzymes (superoxide dismutase, catalase and glutathione peroxidase) in the hearts of both control and streptozotocin-induced diabetic rats. In the heart of diabetic rats, the activity of total superoxide dismutase decreased significantly (p < 0.005), whereas the activity of catalase and glutathione peroxidase increased to a large extent (p < 0.0001 and p = 0.05, respectively) at the end of the fourth week compared with the control group. Glyburide treatment of diabetic rats for 4 weeks corrected the changes observed in diabetic heart. In addition, blood glucose levels of untreated diabetic rats decreased following the glyburide treatment. These results demonstrate that the sulfonylurea glyburide is capable of exerting direct insulin-like effect on heart superoxide dismutase, catalase and glutathione peroxidase activities of diabetic rats in vivo.

Matrix metalloproteinase-9 in broncho-alveolar lavage fluid of patients with non-small cell lung cancer.

AIM: To evaluate concentration of MMP-9 in blood plasma and broncho-alveolar lavage fluid (BALF) from patients with non-small cell lung cancer (NSCLC). METHODS: Blood plasma from 40 NSCLC patients and 40 healthy donors was collected and concentrations of blood plasma and BALF MMP-9 were measured using ELISA. Correlation between MMP-9 level and gender, histological type of tumor and stage of disease was analyzed. RESULTS: Levels of blood plasma MMP-9 were significantly higher in NSCLC patients (p < 0.0001) then in control group, and were especially high in patients with stage IV of disease (stage I vs stage IV - p < 0.005, stage II vs stage IV - p < 0.01, stage III vs stage IV - p < 0.01). Also, stage IV of NSCLC was characterized by the highest level of BALF MMP-9 (stage I vs stage IV - p < 0.002, stage II vs stage IV p < 0.002, and stage III vs stage IV p < 0.007). Correlation between blood plasma and BALF MMP-9 levels and gender or histological type of tumor was insignificant. CONCLUSION: Our data revealed significant correlation between tumor stage and BALF and plasma MMP-9 levels in NSCLC patients.

The effect of the sulfonylurea glyburide on nitric oxide in streptozotocin-induced diabetic rat.

1. The interaction between nitric oxide (NO) and superoxide anions has received a great deal of attention. Because NO is rapidly inactivated by superoxide anions, it has been suggested that an enhanced formation of this radical may be involved in the accelerated breakdown of NO. 2. In the present study, we administrated glyburide (glibenclamide) to Streptozotocin-induced diabetic rats and determined the effect of such treatment on serum nitrite+nitrate levels. Serum nitrite+nitrate levels were reduced in diabetic animals (P<0.001). Administration of glyburide to diabetic rats reversed the diabetes-induced changes, suggesting that glyburide may directly increase serum nitrite+nitrate levels.

Nitric oxide biosynthesis and malondialdehyde levels in advanced breast cancer.

BACKGROUND: Nitric oxide (NO) is a free oxygen radical studied in many tissues. Its tumour killing structure is shown especially by macrophages. The end products of NO are nitrite and nitrate. Their plasma levels are used biochemically to determine nitric oxide synthase (NOS) activity. The proliferative capacity of cancer cells accompanies the alteration in oxidant-anti-oxidant status. The risk of breast cancer is decreased in association with an increased level of polyunsaturated fatty acids in the erythrocyte membranes. The more the anti-oxidant capacity increases, the more the transformed cells grow. Malondialdehyde (MDA) is a lipid peroxidation marker, and low plasma levels of MDA are associated with advanced stages of breast cancer. METHODS: In the present study, the alteration of serum plasma levels of nitrate, nitrite and MDA were determined in patients with stage IIIB breast cancer and controls. RESULTS: It was found that products of NO biosynthesis were higher and plasma MDA levels were lower in patients with breast cancer. CONCLUSIONS: It can be stated that in advanced breast cancer, the NO radical production is increased while the lipid metabolism is altered, and these changes can be related to an alteration in oxidant-anti-oxidant status.