Performance Evaluation of Urine Osmolality Measurement on Sysmex UF-5000 and the Effect of Molecules and Particles in Urine.

BACKGROUND: Urine osmolality determines the concentration ability of the kidney. Therefore, it is used to assess the body's hydration status, electrolyte levels, and acid-base disturbances. We aimed to evaluate the analytical performance of osmolality measurement of the Sysmex UF-5000 (UF-5000), to examine the effect of different molecules and particles in the urine on the osmolality measurement. METHODS: Complete urinalysis and conductivity-based osmolality analysis with UF-5000 and osmolality analysis with Advanced® Model 3320 Micro-Osmometer (AI-3320) by freezing point reduction method were performed in the urine samples. Samples were grouped as negative, glucosuria, proteinuria, hematuria, pyuria, crystalluria, and urobilinogen. RESULTS: Total impressions were calculated as < 5% and accuracy values were < 1.66% in both analyzers. The regression equation was found to be y = -12.54 + 0.956x and the relative difference between the analyzers was 8.7% in 586 samples. When patients with Glucose > 2+ were excluded the regression equation of 507 samples was found as y = 5.10 + 0.948x and the relative difference was 4.6%. The percentages of samples with a difference greater than the allowable difference were 18.8%, 11.6%, 35.9%, 13.7%, 18.7%, and < 12.2% in all samples, all samples without glucosuria > 2+, glucosuria, glucosuria < 3+, proteinuria, and other subgroups, respectively. CONCLUSIONS: Considering the good accessibility of the automated routine complete urine analyzer, UF-5000 can be considered to determine whether urine osmolality is within reference or should be measured by methods based on colligative properties. Thus, referral of patients to a clinic that uses the colligative measurement method may be used more effectively.

Protective and therapeutic effects of okra seed in acute nontraumatic brain injury.

AIM: The purpose of this study was to examine the protective and therapeutic effects of okra (Abelmoschus esculentus [AE]) seed extract, with its known antioxidant, immunomodulatory, and anti-inflammatory properties, in an acetaminophen (paracetamol, N-acetyl- para-aminophenol)-induced model of hepatotoxicity and subsequent acute non-traumatic brain damage. MATERIAL AND METHOD: Forty male Wistar rats were randomly divided into five equal groups, control, paracetamol (P), okra seed extract (AE), okra seed extract + paracetamol (P + AE), and okra seed extract + paracetamol + N-acetyl cysteine (NAC) (P + AE + N). AE was administered by oral gavage through a gastric tube at 600 mg/kg/day for seven days. On the eighth day of the procedure, a single 1 g/kg dose of paracetamol and 300 mg/kg NAC were injected via the intraperitoneal route 1.5 h after AE administration. Rat tissue specimens were subsequently subjected to biochemical and histopathological analyses. Levels of markers such as S100 calcium-binding protein B (S100B), neuron-specific enolase (NSE), and matrix membrane metalloproteinase-9 (MMP-9) were investigated from rat serum specimens. Malondialdehyde (MDA) and superoxide dismutase (SOD) were also measured to determine oxidant-antioxidant status. RESULTS: S100B, NSE, MMP-9, MDA levels, and SOD enzyme activities were examined using biochemical methods. MDA levels were significantly lower in the P + AE group and MMP-9 levels in the AE, P + AE, and P + AE + N groups compared to the P group. Histopathological examination results supported the biochemical findings. CONCLUSION: Okra seed extract exhibits a protective and therapeutic effect against non-traumatic brain damage resulting from acute paracetamol intoxication. We think that this benefit of AE derives from its antioxidant property.

Dynamic thiol-disulfide homeostasis as an oxidative stress marker in ankylosing spondylitis and undifferentiated spondyloarthropathy.

Background/aim: Seronegative spondyloarthropathies (SpA) are a group of chronic diseases characterized by axial inflammation, oligoarthritis, and enthesitis. Oxidative stress may contribute to a wide range of rheumatologic diseases, including SpA. This prospective case-control study was designed to compare thiol-disulfide levels as a marker of oxidative stress between SpA patients and healthy controls. Materials and methods: A total of 144 patients diagnosed with undifferentiated spondyloarthropathy (USpA, n = 97) or ankylosing spondylitis (AS, n = 47) were included along with 80 healthy controls. Serum native thiol (NT), total thiol (TT), and disulfide (D) levels were measured using the fully automated Erel method. The ratios NT/TT, D/TT, and D/NT were calculated. Thiol-disulfide levels were compared between the SpA groups and the healthy controls. Results: The NT and NT/TT ratios were found to be significantly lower in the SpA group (p < 0.001). The disulfide, D/NT, and D/TT ratios were found to be significantly higher in the SpA group (p < 0.001). In pairwise comparisons between the SpA subgroups, the NT and TT levels were lower in the USpA group than in the AS group (p = 0.021), but serum disulfide levels were higher in the USpA group than in the AS group (p = 0.004). Among the patients with SpA, the group taking antitumor necrosis factor (anti-TNF) had lower TT measurements compared to the group taking conventional disease modifying antirheumatic drugs (DMARD) (p = 0.039). Conclusion: The thiol-disulfide balance is disturbed in favor of disulfide in SpA patients compared to healthy volunteers. Native and total thiol measurements correlate with acute phase reactants and might be used to monitor disease activity. Anti-TNF therapy might control the oxidative degenerative process better than the conventional DMARD in SpA patients.

C-Reactive Protein to Albumin Ratio in Patients with Prediabetes and Diabetes Mellitus: HbA1c and Inflammation.

BACKGROUND: Inflammation has a significant status in both the pathogenesis and complications of diabetes mellitus (DM). The aim of this study is to compare the C-reactive protein (CRP) to albumin ratio (CAR) values in controlled DM, uncontrolled DM, prediabetes groups grouped by HbA1c as well as in a group of healthy individuals. METHODS: In this retrospective study, 6,993 DM patients, 770 prediabetes patients, and 1,340 healthy individuals were included. According to their HbA1c levels, DM patients were divided into two groups as controlled DM (HbAlc < 6.5%, n = 4,115) and uncontrolled DM (HbAlc ≥ 6.5%, n = 2,878). RESULTS: The CRP and CAR levels were significantly higher in the DM and prediabetes group than in the control group (p < 0.05, for both). Albumin levels were significantly lower in the DM group than in both the prediabetes and control groups (p < 0.05, for both). In the uncontrolled DM group, CRP and CAR values were found to be significantly higher than the control and controlled DM groups, while albumin values were significantly lower than the control group, prediabetes group, and controlled DM group (p < 0.05, for all). CONCLUSIONS: It is thought that CAR, a liver related inflammatory marker, can be applied as an inflammation marker in both prediabetes, determined by HbA1c, and patients diagnosed with DM. Further prospective studies will better demonstrate the utility of CAR values as an inflammatory marker in DM and prediabetes.

Analytical Performance Evaluation of Siemens Sysmex CS-2500 and Sekisui CP-3000.

BACKGROUND: Automatic coagulation analyzers have been used in the last 50 years and have been developed considerably. Newly developed tests and methods cannot be conducted in routine laboratories without evaluating their performance. Therefore, their performance must be evaluated and approved before being used routinely. The aim of this study is to evaluate the analytical performance of Sysmex Coagulation System-2500 (CS-2500) and Sekisui CP-3000 automatic coagulation analyzer (CP-3000). METHODS: For APTT, PT, and D-dimer tests, reference range verification study, a method comparison study was performed in both analyzers in accordance with CLSI protocols, and precision and accuracy were evaluated using internal and external quality control samples. In the evaluation of precision and accuracy, CV% and bias% values were calculated. Bland-Altman, Passing-Bablok regression analysis, and correlation coefficient were used in the comparison study. RESULTS: The CV% values calculated for APTT and PT in both analyzers were found to be below the CLSI recommendation of 5%. D-dimer test results meet the quality criteria recommended by CLSI. Accuracy for both analyzers was within the acceptable limits. The reference ranges recommended by the manufacturer have been veryfied. Regression equations for APTT, PT, and D-dimer are y = -3.313 + 1.188x, y = -0.0399 + 1.048x, and y = 0.155 + 0.655x, respectively, and r values were 0.904, 0.978, and 0.974, respectively. CONCLUSIONS: CS-2500 and CP-3000 analyzers are suitable for laboratory use for routine coagulation. Since the CP-3000 device is newly used in our country, it needs to be supported by more comparison studies.

How do thiol disulfide balance and copper-ceruloplasmin levels change in women using copper intrauterine devices?

ObjectivesWe aimed to examine the change in plasma copper (Cu) level and copper transport proteins level before inserting Cu-IUD and after one menstrual cycle and to show the effect of this change on the thiol disulfide balance in women using copper-containing intrauterine device (Cu-IUD).MethodThirty-three reproductive women who admitted to the gynecology clinic and inserted Cu-IUD were examined in this study. Thiol-disulfide homeostasis, plasma Cu and ceruloplasmin levels and ceruloplasmin ferroxidase activity were measured using the blood samples collected just before inserting Cu-IUD and after one menstrual cycle.ResultsPlasma copper level (p = 0.006), ceruloplasmin (p < 0.001), Ceruloplasmin Ferroxidase (p = 0.005), thiol disulfide homeostasis parameters; native thiol (NT) (p = 0.004), and total thiol (p = 0.003) levels increased significantly.ConclusionAfter one menstrual cycle in women inserted intrauterine Cu-IUD for contraception, plasma levels of Cu, which is the oxidant molecule, increased significantly. Both plasma ceruloplasmin level and ceruloplasmin ferroxidase activity increased due to elevated Cu levels. This increased oxidant status in the acute period was balanced by the increase in the native thiol level.

The evaluation of maternal systemic thiol/disulphide homeostasis for the short-term prediction of preterm birth in women with threatened preterm labour: a pilot study.

The aim of this study was to investigate maternal systemic thiol/disulphide homeostasis (TDH) for the short-term prediction of preterm birth in women with threatened preterm labour (TPL). This prospective study included 75 pregnant women whose pregnancies were complicated by TPL. Thirty-seven of them delivered within 7 days and 38 of them delivered beyond 7 days. Maternal serum samples were collected at the day of diagnosis and the TDH was measured. The maternal disulphide level was significantly higher in pregnant women who delivered within 7 days (25.0 ± 9.8 µmol/L vs 19.4 ± 9.8 µmol/L, p: .015). The threshold value of 22.1 µmol/L for maternal disulphide level predicted delivery within 7 days with 62.2% sensitivity and 60.5% specificity (area under curve 0.651, confidence interval 0.53-0.78). The likelihood ratios for short cervix (≤25 mm) and maternal disulphide level (≥22 µmol/L) to predict delivery within 7 days was found to be 8.7 and 7.3, respectively. The likelihood ratio of combining two tests to predict delivery within 7 days was found to be 11.4. The maternal TDH, which is an indicator of oxidative stress status in maternal compartment, is disturbed in TPL cases who delivered within 7 days. Elevated maternal disulphide level along with cervical length screening predicts a short latency period in pregnancies with TPL. IMPACT STATEMENTWhat is already known on this subject? Spontaneous preterm delivery is one of the major complication of pregnancy and the common cause of neonatal morbidity and mortality. Threatened preterm labour (TPL) is also a frequent complaint in obstetric emergency care units in all around the world. Triaging women with TPL is mandatory for planning further management therapies, since the most of them will eventually deliver at term. Only the measurement of cervical length in symptomatic women has moderate accuracy in predicting preterm delivery. Short cervix is described as an independent predictor of preterm delivery in women with TPL, its predictive accuracy as a single measurement is relatively limited. On this account, several potential markers like foetal fibronectin in the cervicovaginal fluid, salivary oestriol, prolactin in vaginal discharge, maternal serum calponin and interleukin-6 in the amniotic fluid were examined to predict preterm delivery in previous studies. However, none of them represented an excessive predictive accuracy like high sensitivity, PPV or NPV.What do the results of this study add? We report a method which has higher diagnostic and predictive performance to identifying TPL women with high risk of preterm delivery. According to the current literature, there are accumulated data about the correlation between oxidative stress (OS) and preterm delivery regardless of the amniotic membrane status. However, it is still debated whether OS is a trigger or a consequence of preterm delivery. Our study provides evidence for the first time that maternal serum thiol/disulphide homeostasis, which is an indicator of OS in maternal compartment, is disturbed in TPL cases who delivered within 7 days. The high disulphide level in maternal serum, along with cervical length measurement (short cervix) accurately predicts a short latency period in TPL cases.What are the implications of these findings for clinical practice and/or further research? This novel test combination (maternal serum disulphide level and cervical length measurement) could be used clinically to triage pregnant women presenting with TPL, avoiding overtreatment, unnecessary hospitalisations and increased medical costs. The future research would be addressed on reducing maternal OS by using new antioxidant treatment strategies to improve perinatal and long-term childhood outcomes.

Evaluation of dysfunctional high-density lipoprotein levels with myeloperoxidase/paraoxonase-1 ratio in rheumatoid arthritis.

BACKGROUND: The aim of this study is to evaluate dysfunctional high-density lipoprotein cholesterol (HDL) by measuring myeloperoxidase (MPO)/paraoxonase 1 (PON1) ratio in patients with rheumatoid arthritis (RA) and to investigate the relationship between dysfunctional HDL and cardiovascular disease (CVD) in RA patients. METHODS: Sixty-seven healthy individuals and 130 RA patients were included in the study. Routine lipid panels (triglyceride (TG), low-density lipoprotein cholesterol (LDL), HDL, total cholesterol (TC), PON1 and MPO levels were measured. Disease activity scores-28 (DAS28) of RA patients were calculated. Cardiological examination records of the patients were assessed to detect patients who also have CVD. RESULTS: There were no significant differences between RA and control groups in routine lipid profiles (P > .05 for all). MPO/PON1 ratios were significantly elevated in the RA group compared with the control group (P < .001). MPO/PON1 ratios were higher in RA patients with CVD history compared with those without CVD (P < .05). MPO/PON1 ratios were correlated with DAS28 scores (rho: 0.357, P < .001). CONCLUSION: HDL dysfunction determined by the MPO/PON1 ratio may be associated with the pathophysiology of increased CVD in RA. Thus, evaluating dysfunctional HDL levels by measuring the MPO/PON1 ratio in RA patients may allow more detailed patient follow-up, as well as the reduction of CVD events in RA patients with therapeutic agents aiming to increase the functional properties of HDL by decreasing this ratio.

Dynamic Thiol/Disulphide Homeostasis as Oxidative Stress Marker in Ankylosing Spondylitis and Undifferentiated Spondyloarthropathy.

AIM: Seronegative spondyloarthropathies (SpA) are a group of chronic diseases, characterized by axial inflammation, oligoarthritis, and enthesitis. Oxidative stress may contribute to a wide range of diseases such as rheumatologic diseases including SpA. This prospective case-control study was designed to compare the thiol-disulfide levels as a marker of oxidative stress in SpA patients with healthy controls. METHODS: A total of 144 patients who were diagnosed as undifferentiated spondyloarthropathy (UspA, n=97), ankylosing spondylitis (AS, n=47), and 80 healthy controls were included. Serum native thiol (NT), total thiol (TT), disulfide (D) levels were measured with the fully automated Erel?s method. NT/TT, D/TT, and D/NT ratios were calculated. Thiol-disulfide levels were compared between SpA groups and healthy controls. RESULTS: NT and NT/TT ratios were found to be significantly lower in the SpA group. (p<0.001). Disulfide, D/NT, and D/TT ratios were found to be significantly higher in the SpA group (p <0.001 for each comparison). In pairwise comparisons between SpA subgroups, NT and TT levels were lower in USpA group compared to AS group (P=0.021). Serum disulfide levels were higher in USpA group compared to AS group (P=0,004). Anti-tumor necrosis factor (Anti-TNF) group had lower TT measurements compared to the classical disease-modifying anti-rheumatic drugs (cDMARD) group in patients with SpA (P=0.039). CONCLUSION: Thiol-disulfide balance is disturbed in favor of disulfide in SpAs patients compared to healthy volunteers. Native and total thiol measurements correlate with acute phase reactants and might be used to monitor disease activity. Anti-TNF therapy might control the oxidative degenerative process better than the classical DMARD in SpA patients.

The impact of oxytocin on thiol/disulphide and malonyldialdehyde/glutathione homeostasis in stressed rats.

We aimed to investigate the impact of oxytocin on serum thiol/disulphide and malonylyldialdehyde (MDA)/glutathione balance under acute stress (AS) and chronic stress (CS) exposure in rats. Animals were allocated into control (C), AS and CS groups, then the groups subdivided as intranasal oxytocin or saline applied groups, randomly. Animals in the AS or CS groups were exposed to combined cold-immobilisation stress. Salivary corticosterone levels and elevated plus maze (EPM) scores were used to assess stress response. MDA, glutathione, thiol-disulphide levels were measured in the serum samples. Oxytocin treatment attenuated stress response regardless of the stress duration verified by lower corticosterone level and favorable profile in EPM parameters measured. Furthermore, oxytocin modulated oxidant profile suggesting lowered oxidant stress with decreased serum MDA/glutathione and disulfide/native thiol ratios. Oxytocin improves the response of organism to stress via both its anxiolytic and antioxidant effects. That's why it can be considered as a protective measure to employ methods to increase endogenous oxytocin and/or to apply exogenous oxytocin to prevent stress-induced increase in oxidant stress, which plays a pivotal role in the pathogenesis of various stress-related diseases.

Dynamic thiol/disulfide homeostasis in patients with lichen planus.

OBJECTIVE: Lichen planus (LP) is an autoimmune inflammatory disease of the mucocutaneous tissue, whose exact pathological course remains unclear. Abnormal thiol/disulfide homeostasis has been postulated to be responsible for a number of diseases predominated by chronic inflammation. To be able to contribute complicated and unclear pathogenesis of LP, we aimed to investigate dynamic thiol/disulfide homeostasis in patients with LP, using an original automated method developed by Erel and Neselioglu in this study. METHODS: The study group consisted of 81 unrelated patients with LP and 80 unrelated healthy controls with no LP lesions in their personal history or on clinical examination. Thiol/disulphide homeostasis tests have been measured with a novel automatic spectrophotometric method developed and the results have been compared statistically. RESULTS: Native thiol and total thiol levels were found as significantly higher in patients with LP than the control group (P = 0.026 and 0.035, respectively). There was no significant difference between the disulfide levels of the patients with LP and the control group. CONCLUSIONS: We provide evidence that that thiol/disulphide homeostasis impaired in favor of thiol levels in LP patients compared to the control group based on the data of our study. To the best of our knowledge, the present study is the first examination on the correlation between thiol and disulfide homeostasis in patients with LP.

Serum endocan level and diastolic functions in the case of lead exposure

Background/aim: Lead can cause morphological and functional changes in heart, and inflammation and endothelial dysfunction in vasculature. Endocan, as a novel indicator of endothelial dysfunction, has been used for cardiovascular diseases. This study investigated the relationship between lead exposure, endocan levels, and diastolic functions. Materials and methods: A total of 51 lead-exposed workers without a known cardiovascular disease or risk factors and 54 healthy controls were enrolled. All participants underwent transthoracic echocardiography. Blood lead and serum endocan levels were analyzed. Results: Baseline demographic and clinical characteristics were found to be similar between groups. Median blood lead (32 vs 1.5 µg/dL, P < 0.001) and serum endocan levels (67 vs 57.1 pg/mL, P = 0.02) were significantly higher in the lead-exposed group. Serum endocan level showed a positive correlation with blood lead levels (r = 0.404, P = 0.003) in lead-exposed workers. Serum endocan level was an independent risk factor for increased E/E' ratio (ß = 0.704, P = 0.002) and left atrial volume index (ß = 1.158, P = 0.011) and higher level of lead in blood was an independent risk factor for increased E wave (ß = 8.004, P = 0.022) in lead-exposed workers. Conclusion: Worsened diastolic functions may be seen in the course of lead exposure. Due to sharing a similar mechanism, a higher serum level of endocan may be a valuable laboratory clue for impaired diastolic function in this population.

Evaluation of the level of dynamic thiol/disulphide homeostasis in adolescent patients with newly diagnosed primary hypertension.

BACKGROUND: Thiol/disulphide homeostasis plays a critical role in numerous intracellular enzymatic pathways including antioxidant defense and detoxification. This study was designed to investigate the impact of thiol/disulfide homeostasis in adolescent patients with recently diagnosed primary hypertension (HT) using a novel and automated method. METHODS: Native thiol/disulphide levels were measured by a novel spectrophotometric method (Cobasc 501, Roche Diagnostics, Mannheim, Germany) in 30 patients with primary HT together with 30 healthy controls. RESULTS: The levels of native thiol, total thiol, and native thiol/total thiol ratios were significantly lower, while the disulphide level, disulphide/native thiol, and disulphide/total thiol ratios were significantly higher in patients with primary HT compared with the control group. There were significant positive correlations between 24-h mean systolic and diastolic blood pressure and disulphide levels, disulphide/native thiol, and disulphide/total thiol ratios. A multiple linear regression model showed that a disulphide/native thiol ratio above 5 and family history of HT are independent predictors of HT. CONCLUSIONS: Our study showed that dynamic thiol/disulphide homeostasis shifted towards disulphide formation in adolescent patients with primary HT. Understanding the role of thiol/disulfide homeostasis in primary HT might provide new therapeutic intervention strategies for patients.

Publisher Correction: Evaluation of the level of dynamic thiol/disulphide homeostasis in adolescent patients with newly diagnosed primary hypertension.

Owing to an error in typesetting, the name of the author Atilla Halil Elhan was rendered wrongly. The original publication has now been corrected in this respect.

Does thiol-disulphide balance show oxidative stress in different MEFV mutations?

Many studies have shown that oxidative stress levels increase in patients with Familial Mediterranean Fever (FMF). Thiols are a class of compounds that include a sulfhydryl group (-SH) and can react with free oxygen radicals to protect tissues. We aimed to investigate thiol-disulphide homeostatic status in FMF patients and examined the effect of different mutations in the MEFV gene on the thiol-disulphide balance. We investigated thiol-disulphide parameters in patients with FMF and healthy controls. To determine the differential effect of MEFV gene mutations on thiol-disulphide balance, subjects were divided into five groups based on homozygous or compound heterozygous exon 10 and nonexon 10 mutations. Tests of thiol-disulphide homeostasis were conducted using the automated spectrophotometric method. Patients with FMF had significantly lower native thiol [433.8 µmol/l (243.3-536.4) vs. 484.1 µmol/L (340.2-612.3), p  < 0.001], total thiol levels [459.7 µmol/L (281.3-575.4) vs. 529.9 µmol/L (363-669.5), p < 0.001], and disulphide levels [14.0 µmol/l (2.7-33.3) vs. 24.4 µmol/l (7.2-36.6), p < 0.001] compared to the control group. Moreover, disulphide/native thiol (3.4 ± 1.7 vs. 4.7 ± 1.3, p < 0.001) and disulphide/total thiol (3.1 ± 1.4 vs. 4.3 ± 1.0 p < 0.001) were also detected lower in the FMF group compared to the control group. But the native thiol/total thiol ratios (93.6 ± 2.9 vs. 91.3 ± 2.1, p < 0.001) were higher in the FMF group. There was no significant difference between the native thiol, total thiol, and disulphide levels of individuals with nonexon 10 homozygous or compound heterozygous (Group 1), nonexon 10-exon 10 compound heterozygous (Group 2), exon 10 homozygous or compound heterozygous (Group 3), and heterozygous (Group 4) mutations. However, these parameters significantly differed from those of the healthy control group. Since no differences were found in our study between thiol and disulfide levels of Groups 1, 2 and 3, we believe that this rate cannot be shown as an indicator of oxidative damage in different mutations of FMFs. To the best of our knowledge, this study is the first study that demonstrates the effect of different FMF mutations on the thiol-disulphide balance.

The Impact of Repetitive Transcranial Magnetic Stimulation on Oxidative Stress in Subjects With Medication-Resistant Depression.

OBJECTIVES: Recent studies have shown that oxidative stress is involved in the neurobiology of depression. We investigated the effects of repetitive transcranial magnetic stimulation (rTMS) on a novel oxidative stress marker, thiol-disulfide homeostasis, in subjects with medication-resistant major depression (MRD). METHODS: Twenty-six subjects with MRD underwent 15 rTMS sessions. Sociodemographic and baseline and post-rTMS Montgomery-Asberg Depression Rating Scale (MADRS) data were collected. Serum levels of native thiol, total thiol, and disulfide and their pairwise ratios were measured in baseline and post-rTMS blood samples. RESULTS: Serum levels of native and total thiol were significantly decreased after rTMS treatment (P < 0.05). Serum levels of thiol-disulfide and their ratios did not significantly differ (P > 0.05) between rTMS treatment responders (>50% reduction in MADRS score, n = 11) and rTMS treatment nonresponders (n = 15). The percentage MADRS score changes did not correlate with the changes in the levels of serum thiol-disulfide from baseline to post-rTMS treatment in any subject (P > 0.05). CONCLUSIONS: Our results showed that rTMS treatment was effective in subjects with MRD and was associated with changes in serum thiol levels regardless of improvement in depression severity. Thus, the results did not support a possible therapeutic relationship between rTMS and thiol-disulfide homeostasis in subjects with MRD.

Thiol/disulphide homeostasis in schizophrenia patients with positive symptoms.

INTRODUCTION: This study aims to investigate the dynamic thiol/disulphincide homeostasis in patients with schizophrenia who have positive psychotic indications. MATERIALS AND METHODS: Forty-four patients (26 males, 18 females; mean age = 34.40 ± 8.98 years) accepted at the Department of Psychiatry of the Ankara Numune Training and Research Hospital and 33 healthy controls (15 males, 18 females; mean age of 30.30 ± 8.48 years) were included in the study. Serum native thiol and total thiol were measured with a novel colorimetric, automated method. The disulfide levels and disulfide/native thiol ratios were also calculated from these measured parameters. RESULTS: Serum native thiol and the total thiol concentration were significantly lower in schizophrenia compared with the control group (p < .05). Disulphide levels and disulfide/native thiol ratios were significantly higher in schizophrenia compared with the control group (p < .05). When the patients were divided into two groups according to those who used medication and those who did not for the last two months, it was found to be significantly higher in those who used disulfide and disulfide/native thiol medication than those who did not use medication. CONCLUSION: The disulfide/native thiol ratio in patients with schizophrenia who have been using medication for the last 2 months has been found to be significantly higher than controls who have not been using medication, may be indicating that the level of native thiol does not increase in a correlation as high as the increase in disulfide levels. It demonstrates that thiol/disulfide equilibrium has shifted towards the disulfide. The excess disulfide amounts might associated with both disease itself and the using medication.

Dynamic Thiol/Disulphide Homeostasis in Children and Adolescents with Non-Autoimmune Subclinical Hypothyroidism.

OBJECTIVE: To evaluate the thiol/disulphide homeostasis in children with non-autoimmune subclinical hypothyroidism (SHT). SUBJECTS AND METHODS: Thiol/disulphide homeosta sis, involving native thiol (SH), disulphide (SS), and total thiol (SS + SH), was evaluated in 60 children and adolescents who were negative for thyroid auto-antibodies (anti-thyroid peroxidase, anti-thyroglobulin) and had a thyroid-stimulating hormone (TSH) value of > 5 mIU/L, and in 40 sex- and age-matched healthy control subjects who were negative for thyroid autoantibodies and had normal TSH levels. Lipid profiles and urine iodine levels were also determined. RESULTS: SH (466 ± 32.8 vs. 462 ± 32.1 µmol/L p = 0.59), SH + SS (508 ± 34.0 vs. 506 ± 32.7 µmol/L, p = 0.81), SS (21 ± 5.5 vs. 22 ± 5.8 µmol/L, p = 0.41), SS/SH (4.5 ± 1.2 vs. 4.8 ± 1.3%, p = 0.36), SS/SH + SS (4.1 ± 1.0 vs. 4.3 ± 1.1%, p = 0.36) and SH/SH + SS (91 ± 2.1 vs. 91 ± 2.1%, p = 0.31) levels were similar in children with SHT and control subjects (p > 0.05). There was no difference between total cholesterol, triglyceride, and low-density lipoprotein levels in SHT patients and controls. No difference was detected between the patients with or without iodine deficiency in the SHT group in terms of thiol/disulphide homeostasis parameters. CONCLUSION: The status of dynamic thiol/disulphide homeostasis did not change in children and adolescents with non-autoimmune SHT. Future studies are needed for the evaluation of oxidative stress in patients with long-standing non-autoimmune SHT.

A new potential biomarker in early diagnosis of firefighter lung function impairment: dynamic thiol/disulphide homeostasis.

OBJECTIVES: The aim of this study was to investigate the associations between urinary arsenic, oxidative stress, assessed by thiol/disulphide homeostasis, and lung diseases in firefighters. METHODS: The study conducted among the municipality-based male firefighters (n = 100) who were admitted to occupational diseases clinic for periodic medical examination. The control group consisted of non-exposed male office workers (n = 50). Urinary arsenic levels, thiol/disulphide homeostasis parameters of participants were determined. Also, lung diseases were assessed by chest X-ray and pulmonary function tests. RESULTS: The mean age and work year did not differ in the study and control group. The median urinary arsenic concentration of firefighters was significantly higher than in the control group: 15.65 (2.5-246) µg/L and 3 (0.10-6) µg/L, respectively (p < 0.001). The parameters of pulmonary function tests (PFT) FVC (%), FEV1 (%), FEV1/FVC ratio and FEF 25-75 (%) were all significantly lower in firefighters compared to controls. A significant increase in mean serum disulphide concentration (17.10 ± 8.31 µmol/L vs. 7.48 ± 5.91) (Fig. 1) and disulphide/native thiol % ratio: 3.63 (0.53-11.43) vs. 1.51 (0.03-7.65) (p < 0.001) were found between exposed group and controls. The Spearman's correlation analysis revealed a positive correlation between urinary arsenic and disulphide (r = 0.422, p < 0.001), disulphide/native thiol % ratio (r = 0.409, p < 0.001). Nevertheless, urinary arsenic correlated negatively with all PFT parameters including FVC (%), FEV1 (%), FEV1/FVC and FEF 25-75 (%) (p < 0.001). CONCLUSION: We showed the arsenic-induced oxidative stress in firefighters with impairments of several lung functions determined by thiol/disulphide homeostasis using a novel method.

Dynamic thiol/disulfide homeostasis in children with attention deficit hyperactivity disorder and its relation with disease subtypes.

BACKGROUND: The aim of this study was to evaluate a novel oxidative stress marker (thiol/disulfide homeostasis) in attention deficit hyperactivity disorder (ADHD) children for the first time in literature. METHODS: Ninety children with ADHD diagnosed according to DSM-V and as control group, 65 healthy children were included to the study. Native thiol, total thiol, disulfide, disulfide/native thiol, disulfide/total thiol were compared between the groups. RESULTS: Total and native thiol levels were significantly higher whereas the disulfide/native thiol ratios were significantly lower in children with ADHD. ADHD combined type appeared to have higher disulfide, disulfide/native thiol and disulfide/total thiol ratios compared to other subtypes. Disulfide levels of the males with ADHD were significantly higher than those of the females with ADHD. CONCLUSION: This study suggests that thiol/disulfide homeostasis is abnormal in children with ADHD. It may be used as a novel OS marker in ADHD children because it is easy, practical, fully automated and relatively inexpensive.