Objectives: Calculation of biological variation (BV) components is very important in evaluating whether a test result is clinically significant. The aim of this study is to analyze BV components for copper, zinc and selenium in a cohort of healthy Turkish participants. Methods: A total of 10 serum samples were collected from each of the 15 healthy individuals (nine female, six male), once a week, during 10 weeks. Copper, zinc and selenium levels were analyzed by atomic absorption spectrometer. BV parameters were calculated with the approach suggested by Fraser. Results: Analytical variation (CV _A ), within-subject BV (CV _I ), between-subject BV (CV _G ) values were 8.4, 7.1 and 4.3 for copper; 4.2, 9.1 and 13.7 for zinc; 7.6, 2.5 and 6.9 for selenium, respectively. Reference change values (RCV) were 30.46, 27.56 and 22.16% for copper, zinc and selenium, respectively. The index of individuality (II) values were 1.65, 0.66 and 0.36 for copper, zinc and selenium, respectively. Conclusions: According to the results of this study, traditional reference intervals can be used for copper but we do not recommend using it for zinc and selenium. We think that it would be more accurate to use RCV value for zinc and selenium in terms of following significant changes in recurrent results of a patient.

OBJECTIVE: Substance use disorder (SUD) is a critical public health problem. The use of methamphetamine is increasing daily worldwide. The aetiology of SUD is related to numerous factors that have not been fully elucidated. It is known that there are some changes in oxidative stress in substance use disorder. However, to the best of our knowledge, there is no study showing changes in thiol/disulphide homeostasis (TDH) in methamphetamine use disorder (MUD). METHODS: Forty-four male patients with MUD and forty-five healthy male controls were included in the study. Only patients who had used methamphetamine in the last three months were included. Blood samples were taken from the patients one day after hospitalization and after detoxification for measurement of the thiol/disulphide level. RESULTS: The levels of native thiol, total thiol, and disulphide in the MUD group were significantly higher than in the control group. At the end of the detoxification period, the levels of native thiol and total thiol did not change significantly, but an increase in the disulphide level was observed. CONCLUSION: The results of our study show that there was a shift in the disulphide direction in the TDH, which is an indicator of oxidative stress in the patient group, and this shift continued after the detoxification period of between 5 and 21 days. There is no other study in the literature evaluating TDH in patients with MUD. Therefore, our study is important for clarifying the aetiopathogenesis of SUD.

Objective Thyroid hormones are known to affect the biosynthesis and degradation of antioxidant compounds, suggesting a possible link between hypothyroidism and oxidative stress. However, there is no clear consensus in the literature regarding this association. The aim of this study was to evaluate oxidative stress markers (extracellular thiol-disulfide homeostasis and intracellular glutathione homeostasis) in patients with hypothyroidism due to autoimmune (Hashimoto’s thyroiditis) or nonautoimmune thyroid disease rendered euthyroid after levothyroxine replacement. Subjects and methods The study included 116 patients [...] ABSTRACT Objective Thyroid hormones are known to affect the biosynthesis and degradation of antioxidant compounds, suggesting a possible link between hypothyroidism and oxidative stress. However, there is no clear consensus in the literature regarding this association. The aim of this study was to evaluate oxidative stress markers (extracellular thiol-disulfide homeostasis and intracellular glutathione homeostasis) in patients with hypothyroidism due to autoimmune (Hashimoto’s thyroiditis) or nonautoimmune thyroid disease rendered euthyroid after levothyroxine replacement. Subjects and methods The study included 116 patients

Background: Glutathione, along with its related enzymes, constitutes a key antioxidant defense mechanism against oxidative stress and cancer formation in the body. Among urological malignancies, bladder cancer ranks second following prostate cancer. Oxidative stress has significant involvement in the development and prognosis of bladder cancer. This investigation aimed to examine the impact of glutathione on prognosis in patients with non-muscle-invasive bladder cancer. Methods: This study included 98 patients with high grade non-muscle-invasive bladder cancer who had undergone intravesical Bacillus Calmette–Guérin therapy and 30 healthy controls with no history of uroepithelial carcinoma of the bladder. The patients with bladder cancer were evaluated in three subgroups. Group 1 consisted of 41 patients who did not experience recurrence during follow-up, Group 2 included 28 patients who had recurrent tumors, and Group 3 consisted of 29 patients who progressed to muscle-invasive stages. Blood samples were collected from all participants. Blood levels of reduced, oxidized, and total glutathione were measured spectrophotometrically. Results: Reduced glutathione levels significantly differed among the groups (p < 0.001), attributed to the control group exhibiting higher reduced glutathione levels compared with Groups 1, 2, and 3 (p < 0.001). There were no significant differences in reduced glutathione levels between Groups 1 and 2, Groups 1 and 3, or Groups 2 and 3 (p > 0.05). Total glutathione levels varied significantly among the groups (p < 0.001), with the control group having higher levels than Groups 1, 2, and 3 (p < 0.001). No significant differences were detected between any of the paired patient groups in terms of total glutathione levels (p > 0.05). Regarding oxidized glutathione levels, the difference was statistically significant (p < 0.001), with the control group showing lower levels than the remaining three groups (p < 0.001). Paired comparisons revealed no significant differences in oxidized glutathione levels (p > 0.05). Conclusions: This study revealed that glutathione had an effect on the emergence of bladder cancer but did not affect its prognosis. Nevertheless, we recommend that future studies with larger bladder cancer patient cohorts should be conducted to comprehensively determine the impact of glutathione on the prognosis of this cancer.

Background: The aim of this study is to investigate the myeloperoxidase/paraoxonase ratio which indicates dysfunction of high-density lipoprotein in various types of lymphoma characterized by abnormal lipid metabolism, oxidative stress, and inflammation. Methods: Thirty lymphoma patients and 30 healthy subjects were enrolled in this study. Serum myeloperoxidase, paraoxonase, arylesterase, lipid hydroperoxide and routine biochemistry tests levels were measured on an automated analyzer. The diagnosis of lymphoma patients was made according to the histological examination of the biopsy material. Results: Compared with healthy control group; the albumin, arylesterase, high-density lipoprotein, thiol, and Hemoglobin levels were significantly lower while myeloperoxidase / paraoxonase, myeloperoxidase/arylesterase, and lipid hydroperoxide levels were significantly higher, in patients with lymphoma. Also, lipid hydroperoxide level was significantly correlated with myeloperoxidase / paraoxonase and myeloperoxidase / arylesterase (r= 0.330, p=0.046; r= 0.588, p< 0.001, respectively). Conclusions: We think that dysfunctional high-density lipoprotein is an important factor in the inflammatory process, atherosclerosis, oxidative stress, and impaired lipid metabolism that can be observed in patients with lymphoma. We believe that in the future the myeloperoxidase/paraoxonase ratio can be used as a treatment criterion to prevent diseases that cause dysfunctional high-density lipoprotein.