Recurrent aphthous ulcer (RAU) is an inflammatory condition of the oral mucosa characterized by painful, well-circumscribed, single or multiple round or ovoid ulcerations. The exact etiologic factor(s) of these ulcerations are not yet understood. The objective of this study was to evaluate inflammatory processes and free radical metabolism of 25 patients with RAUs compared to 25 healthy controls. The levels of malondialdehyde (MDA) and glutathione (GSH) were determined by high-performance liquid chromatography. Tumor necrosis factor-alpha (TNF-α), interleukin-2 (IL-2), IL-10, and IL-12 were determined by ELISA. Nitric oxide (NO), myeloperoxidase (MPO), total antioxidant status (TAS), and total oxidant status (TOS) levels were measured spectroscopically in serum. The levels of MDA, GSH, TNF-α, IL-2, IL-12, MPO, and TOS, and oxidative stress index (OSI) were higher, and the levels of NO, IL-10, and TAS were lower in patients with RAU than in controls. Statistical analysis showed that GSH, TNF-α, IL-2, IL-10, and OSI differed significantly in patients with RAU compared to controls. These parameters have important roles in oxidant/antioxidant defense.

We aimed to evaluate oxidative stress [8-hydroxydeoxyguanosine (8-OHdG), malondialdehyde (MDA)] endothelial damage [asymmetric dimethylarginine (ADMA)] and markers of cellular inflammation [interleukin 6 (IL-6), tumor necrosis factor-alpha (TNF-α), neopterin (NP) and high-sensitivity C-reactive protein (hsCRP)] in patients with diabetic nephropathy (DN) and non-diabetic nephropathy who were being administered hemodialysis treatment because of chronic renal failure. In determining 8-OHdG, IL-6 and TNF-α levels, Enzyme-Linked Immuno-Sorbent Assay method was used. Serum MDA, ADMA and NP levels were determined by using high performance liquid chromatography (HPLC). And hs-CRP values were measured with nephelometric method. Serum 8-OHdG and MDA levels were found statistically to have increased when compared with those of the control group in patients groups after dialysis. However, serum ADMA and neopterin levels were observed statistically to have decreased when compared with those of the control group in patients groups after dialysis. But, decreases on ADMA and neopterin levels are still much higher than those of control. IL-6 and TNF-α levels were found to have increased when compared with those of control group in patients groups before dialysis. The oxidative stress in patients with DN, who were being treated with hemodialysis due to chronic renal failure, was higher than that of non-DN patients who were being treated with hemodialysis. In contrast with this, inflammation occurring in non-DN patients was found to have been higher than that of in patients with DN.