Evaluation of thiol/disulphide and oxidant-antioxidant status of dairy cows in periparturient and post-partum period.

BACKGROUND: Thiol/disulphide homeostasis (TDH) has a critical role in many cellular activities such as antioxidant protection. Alterations of oxidative stress in the transition period play an important role in development of some diseases and disorders in dairy cows. OBJECTIVES: The purpose of this study is to assess the total antioxidant status (TAS), total oxidant status (TOS), oxidative stress index (OSI), total thiol, native thiol, disulphide and lipid profile in Simmental and Montofon dairy cows (aged 2-3) before and after calving. METHODS: Blood samples were collected 233-280 days of pregnancy and the 30 days of post-partum. Serum total thiol, native thiol and disulphide levels were determined as well as TAS, TOS and paraoxonase-1 (PON-1) levels were measured using colorimetric assays. Triglycerides (TG), total cholesterol, HDL cholesterol and LDL cholesterol levels were measured with an automatic analyser. RESULTS: Total thiol (p = 0.038) and disulphide (p = 0.015) levels were higher after calving compare to pregnancy in Montofon. TAS was found lower (p < 0.001), and OSI was higher in both breeds (Montofon p = 0.012, Simmental p = 0.028) after calving than in pregnancy. When compared between pregnancy and after calving levels in the same breed, HDL was found to be higher after calving (p < 0.001) and TG was lower after calving (p = 0.020) in Montofon. PON (p = 0.090), HDL (p < 0.001) and cholesterol levels were found higher (p < 0.001) and TG level was lower (p < 0.001) after calving in Simmental. CONCLUSIONS: According to our results, we observed different responses between two breeds before and after calving. There are few studies about TDH in animal research, and this is the first study in the literature that evaluates the TDH along with oxidative stress and lipid profiles in dairy cows in the periparturient and post-partum period.

Deteriorated thiol-disulphide and oxidized-reduced glutathione status in blood in Alzheimer's disease.

BACKGROUND: Alzheimer's disease (AD) is a steadily advancing neurodegenerative condition, the occurrence and prevalence of which are on the rise in various populations. Suspected factors contributing to its development encompass the buildup of amyloid ß (Aß) plaques, the formation of neurofibrillary tangles induced by tau proteins, and heightened oxidative stress. In this study, we aimed to evaluate intra-cellular glutathione status and extracellular thiol-disulphide status in patients with AD. METHODS: Adult patients (>60 years old) diagnosed with AD based on DSM-IV diagnostic criteria were included in the study. Patients were divided into 3 groups as mild, moderate and severe according to Mini Mental Status Examination (MMSE) and clinical findings. Extracellular thiol-disulfide and intracellular oxidized-reduced glutathione status parameters for patient and control groups were analyzed before and after reduction procedures by using reaction of thiol groups with DTNB. RESULTS: The reduced forms of both balances (native thiol (NT) and reduced glutathione (GSH)) were significantly lower in the patient group than the control group (p = 0.031 and <0.001, respectively), while oxidized forms (disulphide (SS) and oxidized glutathione (GSSG)) and SS/NT and GSSG/GSH percent ratios were significantly higher (p < 0.05 for all). The disease duration and oxidative stress were significantly higher in the severe group of AD. There was a shift in intracellular and extracellular thiol balances towards the oxidized side, along with correlations between MMSE and these balances (rho = -0.412 for SS/NT and rho = -0.488 for GSSG/GSH), with GSSG/GSH identified as a significant predictive factor (odds ratio (95 % confidence interval): 1.352 (1.136-1.610) for the moderate group and 1.829 (1.451-2.305) for the severe group. CONCLUSIONS: These findings suggest that blood redox balance is disrupted in AD.

Serum and Follicular Fluid Thiol/Disulfide Homeostasis in Diminished Ovarian Reserve Patients Undergoing In Vitro Fertilization/Intracytoplasmic Sperm Injection Treatment.

INTRODUCTION: The etiologies of diminished ovarian reserve (DOR) are still poorly understood, and many factors such as age, autoimmunity, genetics, idiopathicity, iatrogenesis, and oxidative stress (OS) play a role. Oxidative cellular damage increases following reactive oxygen species (ROS)-induced aging. This is the first study to evaluate the serum and follicular fluid (FF) thiol/disulfide homeostasis in patients under 35 years of age with DOR undergoing in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI). METHODS: In this study, DOR was defined by the Poseidon criteria, and Poseidon group 3 women were selected as the study group (n = 40). The control group was composed of patients with the diagnosis of mild-moderate male factor infertility (n = 30). RESULTS: The FF and serum native and total thiol levels, the markers of the antioxidant system, were significantly decreased in the DOR group compared with the control group (p = 0.021) (p = 0.037) (p = 0.029) (p = 0.04). On the other hand, we found no significant differences in the oxidant parameters between the groups (p > 0.05). CONCLUSIONS: An intrinsic deficiency of antioxidants can play an important role in the etiology of DOR. The dietary addition of antioxidants could be beneficial in DOR patients.

Evaluation of Oxidative Stress by Thiol/Disulphide Homeostasis in Patients with Mycosis Fungoides: A Prospective Double-Centre Study.

Background: Mycosis fungoides (MF) is the most common cutaneous T-cell lymphoma with unknown etiopathogenesis. Oxidant and antioxidant balance is important for cell function and normal metabolism. An imbalance between pro-oxidants and antioxidants causes oxidative stress. A recent focus has been on thiol/disulphide homeostasis as a novel marker of oxidative stress. Aims and Objectives: This study aimed to evaluate the role of oxidative stress in MF by analysing thiol/disulphide homeostasis. Materials and Methods: A total of 103 patients (48 female, 55 male) and a control group of 120 healthy individuals (48 female, 72 male) from two tertiary care hospitals were included in our study. Serum native thiol, total thiol and disulphide levels were evaluated using novel method developed by Erel and Neeliolu. Results: Native thiol levels were 340.30 ± 87.44 in the patient group and 401.62 ± 69.45 in the control group. Total thiol value was 374.17 ± 87.78 in the patient group and 428.54 ± 70.05 in the control group. Native thiol and total thiol levels were significantly lower in the patient group compared to the control group (P < 0.001 and P < 0.001). The disulphide value was 16.93 ± 6.46 in the patient group and 13.46 ± 5.06 in the control group. Disulphide levels were found to be significantly higher in the patient group compared to the control group (P < 0.001). Conclusions: In our study, thiol/disulphide balance shifted towards disulphide which indicates the presence of oxidative stress especially in the early stage while 93.2% of our patients had early-stage MF. We think that this may have pathogenetic and prognostic significance.

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.

Is there a relationship between dynamic thiol/disulfide homeostasis and osteoarthritis progression?

We aim to determine serum dynamic thiol/disulphide homeostasis with novel methods in early-stage osteoarthritis and late-stage osteoarthritis patients and investigated whether it was associated with the progression of osteoarthritis risk or not. One hundred eighteen patients were included in this prospective study. Osteoarthritis patients were divided into five stages, according to the Kellgren-Lawrence scale. Dynamic thiol/disulphide homeostasis was determined with a novel spectrophotometric method. Late-stage osteoarthritis patients had significantly lower levels of native and total thiol than the patients of early-stage osteoarthritis. Disulphide, index-1, index-2 levels, and WOMAC score of late-stage osteoarthritis patients were significantly higher than the ones belonging to patients of early-stage osteoarthritis. Decreased native thiol and total thiol levels and increased WOMAC score and disulphide levels were independently associated with increased risk of late-stage osteoarthritis. We suggest that both WOMAC score and dynamic thiol/disulphide homeostasis may be implicated in the pathogenesis and progression of osteoarthritis. We also recommend that dynamic thiol/disulphide homeostasis may have clinical utility as possible markers of differential diagnosis of early-stage and late-stage osteoarthritis.

Dynamic thiol disulphide homeostasis in patients with surfer's eye: a case-control study.

PURPOSE: The role of oxidative stress in the pathogenesis of pterygium is still unclear. However, abnormal thiol disulfide homeostasis levels are involved in the pathogenesis of various systemic or ocular diseases. We aim to analyze dynamic thiol disulphide homeostasis in patients suffering from conjunctival pterygium using a contemporary technique. METHODS: Thirty-eight subjects suffering from pterygium and 35 age-gender matched healthy volunteers were recruited for the study. For each case, total thiol, disulfide and native thiol levels in blood were obtained. Additionally, the ratio of disulfide over total thiol, native thiol over total thiol and disulfide over native thiol were computed. RESULTS: The level of median native thiol was lower in pterygium group (318.2 µmol/L vs. 333.4 µmol/L) and median disulfide was slightly higher in pterygium group (24.3 µmol/L vs. 22.8 µmol/L) compared to control group. Both disulfide over total thiol and disulfide over native thiol ratios were higher in pterygium group, ratio of native thiol over total thiol was found to be higher in control group. Nevertheless, none of those differences were statistically significant at 95% confidence level. Notably, correlation test pointed to a negative correlation both between pterygium grade and native thiol and between total thiol and pterygium grade in pterygium group (P = 0.03 and 0.02, respectively). CONCLUSION: A negative correlation hinting that slightly weakened dynamic thiol disulphide homeostasis in subjects with pterygium, a local ocular disease. Further studies with larger sample sizes may shed light on this potential relationship and justify systemic antioxidant therapies in these cases.

The relationship between thiol-disulfide balance and idiopathic sudden sensorineural hearing loss.

INTRODUCTION: Impaired cochlear perfusion is a major etiological factor in idiopathic sudden sensorineural hearing loss. Oxidative stress has been shown to be a risk factor for oxidative damage. OBJECTIVES: We investigated the role of oxidative stress in idiopathic sudden sensorineural hearing loss by comparing serum levels of oxidant and antioxidant molecules including thiol/disulfide homeostasis paraoxonase, stimulated thiol/disulfide homeostasis paraoxonase, arylesterase, ceruloplasmin and myeloperoxidase in patients who did and did not recover after treatment. METHODS: The amount of dynamic disulfide was calculated by determining half of the difference between the total thiols and native thiols. After the determination of native, total thiol, and disulfide amounts, the disulfide/total thiol percent ratio, native thiol/total thiol ratio and disulfide/native thiol percent ratio were calculated and then compared between the two groups. Additionally, clinical relationship between audiological recovery and native thiol, disulfide, disulfide/native thiol percent ratio, and disulfide/total thiol percent ratio levels was investigated. Blood samples were also analyzed for the assessment of thiol/disulfide homeostasis paraoxonase, stimulated thiol/disulfide homeostasis paraoxonase, arylesterase, ceruloplasmin, and myeloperoxidase levels. RESULTS: A significant difference was found between the two groups with regard to total oxidant status disulfide, disulfide/native thiol percent ratio, disulfide/total thiol percent ratio, and native thiol/total thiol ratio levels (p =  0.001, p =  0.001, p =  0.001, p =  0.003, p =  0.001, p =  0.002, respectively). However, no significant difference was found between the two groups with regard to thiol/disulfide homeostasis paraoxonase, stimulated thiol/disulfide homeostasis paraoxonase, ceruloplasmin, and myeloperoxidase levels (p >  0.05 for all). CONCLUSION: The results supported the common hypothesis that vascular pathologies are the primary cause of idiopathic sudden sensorineural hearing loss and that other etiological factors ultimately result in vascular pathologies. The oxidant-antioxidant and thiol-disulfide balances were impaired in the idiopathic sudden sensorineural hearing loss group.

Dynamic thiol/disulphide homeostasis and ischemic modified albumin levels in isolated oligohydramnios.

OBJECTIVE: Oligohydramnios is defined as amniotic fluid index in ultrasonographic measurement is less than 5 percentile according to gestational age, the amniotic fluid volume is ≤ 5 cm, or if the single deepest dial is < 2 cm. The condition of oligohydramnios that not with fetal structural/chromosomal abnormalities, intrauterine growth retardation, intrauterine infection and maternal disease is described as isolated oligohydramnios (IO). The aim of this study is to examine whether oxidative stress and reactive oxygen species (ROS) have a place in the pathophysiology of IO. MATERIALS AND METHODS: In this prospective case-control study, a total of 126 participants were included. The patient group consisted of 65 patients who were diagnosed IO, and the control group consisted of 61 healthy normal pregnants. Native thiol (-SH), total thiol (-SH + -SS), dynamic disulfide (-SS), IMA values from maternal serum were measured and compared between groups. RESULTS: Maternal serum -SH and -SH + -SS values were significantly lower in the IO group than in the control group (409.47 ± 55.36 µmol/L vs. 437.40 ± 48.68 µmol/L, p = 0.03 and 457.40 ± 63.01 µmol/L vs. 484.59 ± 52.75 µmol/L, p = 0.01). In the IO group when -SS/-SH and -SS/-SH + -SS ratio was found to be statistically significantly higher than control group (5.84 ± 1.1 vs 5.41 ± 0.71, p = 0.01 and 5.2 ± 0.88 vs 4.8 ± 0.58, p = 0.01), -SH/-SH + -SS ratio was significantly lower (89.56 ± 1.7 vs 90.24 ± 1.16, p = 0.01). There was no significant difference in terms of -SS value (p = 0.66). IMA value was significantly higher in the IO group than control group (0.76 ± 0.10 ABSU vs 0.68 ± 0.06, p < 0.01). It is seen as a result of ROC analysis that -SH, -SH + -SS, -SS/-SH, -SS/-SH + -SS, -SH/-SH + -SS and IMA values have a diagnostic value for IO (p < 0.05). CONCLUSION: The thiol/disulfide balance shifted towards oxidative stress in IO compared to control group. So oxidative stress and ROS have a place in the pathophysiology of IO.

Thiol/disulfide homeostasis impaired in patients with primary Sjögren's syndrome.

BACKGROUND: Primary Sjögren's syndrome (pSS) is a disease associated with the overexpression of proinflammatory cytokines, and oxidative stress is one of the factors responsible for its etiopathogenesis. This study aimed to investigate the thiol/disulphide homeostasis in pSS patients. METHODS: The study included 68 pSS patients and 69 healthy controls. Thiol/disulphide homeostasis (total thiol, native thiol, and disulphide levels) was measured using the automatic spectrophotometric method developed by Erel and Neselioglu, and the results of the 2 groups were compared. RESULTS: The gender and age distributions of the pSS and control groups were similar (P = 0.988 and P = 0.065). Total thiol and native thiol levels were lower in the pSS group than in the control group (470.08 ± 33.65 µmol/L vs. 528.21 ± 44.99 µmol/L, P < 0.001, and 439.14 ± 30.67 µmol/L vs. 497.56 ± 46.70 µmol/L, P < 0.001, respectively). There were no differences in disulphide levels between groups [17.00 (range 0.70-217.0) µmol/L vs. 14.95 (range 2.10-40.10) µmol/L, P = 0.195]. CONCLUSIONS: It was concluded that the thiol/disulphide balance shifted towards disulphide in patients with pSS.

Plasma thiol/disulphide homeostasis changes in patients with restless legs syndrome.

OBJECTIVES: Restless legs syndrome (RLS) is a common neurological condition. Oxidative stress plays an important role in its pathogenesis. Thiol-disulphide homeostasis (TDH) is a new biomarker of oxidative stress. We studied plasma TDH to determine whether TDH could be used as a new biomarker for RLS and evaluated correlations between TDH and various disease severity rating scales. METHODS: A total of 25 RLS patients and 25 healthy controls were included into the study. TDH status was determined using an automated spectrophotometric analysis method and correlations were analyzed between the TDH status and various disease rating scales in the RLS patients. RESULTS: Plasma total (401±27 µmol/L) and native thiol (354±30 µmol/L) levels were significantly lower, but disulphide level (24±6 µmol/L) was significantly (<0.0001) higher in the RLS patients compared to the controls (455±36, 424±37, 15±5 µmol/L, respectively). The disulphide/native thiol and disulphide/total thiol ratios increased, in contrast, native thiol/total thiol ratio decreased significantly in the RLS patients compared to the healthy controls (<0.0001). The disulphide levels correlated positively with age and various rating scores of the RLS patients. International Restless Legs Syndrome Study Group (IRLSSG) rating score and age correlated negatively with the total and native thiol levels. CONCLUSIONS: Our findings indicate increased oxidative stress in the RLS patients reflected by decreased native and total thiol, and increased disulphide levels and positive correlations between the disulphide levels and various rating scores. We suggest dynamic TDH status to be used as a novel biomarker for the diagnosis and follow-up of the RLS patients.

A useful and sensitive marker in the prediction of COVID-19 and disease severity: Thiol.

Thiol-disulphide homeostasis (TDH) is a new parameter indicating oxidative stress that plays a role in the pathogenesis of various clinical disorders. Our study planned to investigate TDH in COVID-19 patients. Age and gender-matched healthy subjects (n = 70) and COVID-19 patients (n = 144) were included in the study. In addition to the routine laboratory parameters of the groups, their native thiol (NT), total thiol (TT) and disulphide levels were measured. Primarily, we compared COVID-19 patients to the healthy control group for inflammatory parameters, NT, TT and disulphide levels. Then, COVID-19 patients were divided into two groups according to the severity of the disease as mild to moderate and severe COVID-19, and the three groups were compared with each other. Predictive value of thiol parameters in the diagnosis of COVID-19 and in the determining its severity, and its correlation with presence and duration of symptoms were investigated. Severe COVID-19 patients had lower NT and TT levels compared with healthy controls and mild to moderate patients (P < 0.001 for both). The results of ROC analysis show that the greatest AUC was IL-6 and NT (AUC = 0.97, AUC = 0.96, respectively) between control and COVID-19 patients, while it was CRP and NT (AUC = 0.85, AUC = 0.83) between mild to moderate and severe patients. A negative correlation was found between duration of symptoms of dyspnoea, cough, fever, and sore throat and NT (r = -0.45, P = 0.017, r = -0.418, P < 0.001, r = -0.131, P = 0.084, r = -0.452, P = 0.040, respectively). NT and TT levels have a strong predictive value in the diagnosis of COVID-19 and in determining disease severity. Our results support that changing TDH parameters appears to have an important role in disease pathogenesis and it can be used in clinical management of patients.

Analysis of thiol/disulphide homeostasis and oxidant-antioxidant status as a result of exposure to radio-frequency electromagnetic fields.

The aim of the current study is to investigate the effect of daily long-term radio-frequency electromagnetic field (RF-EMFs) exposure on thiol/disulphide homeostasis and oxidant-antioxidant status in the serum of rats. Fourteen male Sprague Dawley rats were divided into two equal groups (n = 7). They were grouped as group 1 (sham-control) and group 2 (2100 MHz exposed). Group 2 rats were exposed to GSM-like signals for 5 h/day, 7 days per week for 14 days. In serum of blood samples, the native, total and native/total thiol levels and antioxidant-oxidant parameters were analyzed. The study revealed that the mean serum total thiol levels of GSM exposure group was rather higher than sham-control group (p = 0,219); the mean serum native thiol levels of GSM exposure group was rather higher than sham-control group (p = 0,416), and the mean serum disulphide levels of GSM exposure group was rather higher than sham-control group (p = 0,566). On the other hand, the mean serum total antioxidant status (TAS), total oxidant status (TOS) and oxidative stress index (OSI) of GSM exposure group were higher than sham-control group. There are no data in the literature, that examine the effects of RF-EMFs on thiol/disulphide homeostasis. The results of this study, indicate that RF-EMFs did not cause oxidative stress and statistically changes in thiol/disulphide homeostasis. More sample sizes and longer-term exposures are needed to confirm the results of this study.

Dynamic Thiol/Disulphide Homeostasis in Acute Urticaria.

BACKGROUND: Urticaria is an unknown, sudden, and itchy skin disease that is recognized with redness, swelling, and is sometimes seen with angioedema. It is classified as acute or chronic, depending on the duration of symptoms. Thiols in plasma are powerful antioxidants that physiologically eliminate free radicals. The mostly and rapidly affected proteins are thiols that contain the sulfhydryl group. In the present study, the thiol/disulfide homeostasis was investigated as a brand new indicator of oxidative stress in patients who had acute urticaria and presented to the emergency department. OBJECTIVE: In the present study, the thiol/disulfide homeostasis, ischemia-modified albumin (IMA), and and neutrophil lymphocyte ratio (N/L ratio) were investigated in the etiopathogenesis of acute urticaria. MATERIAL AND METHOD: A total of 37 patients and 40 healthy volunteers were included in the study. Thiol/disulfide homeostasis (TDH) [total thiol-native thiol/disulfide changes] was measured in both groups (patient group and control group) using a brand novel method developed by Erel and Neselioglu. Half of the difference between total thiol and native thiol concentrations gives the amount of disulfide bond. RESULTS: Total thiol and native thiol levels in blood were found to be low. The levels of total thiol (P = 0.218) and native thiol (P = 0,001) were significantly lower in patients with acute urticaria than in the control group. At the same time, the level of disulfide was significantly higher in the patient group than in the control group (P = <0.001). The level of IMA was higher in the patient group than in the control group (P < 0.001). CONCLUSION: While total thiol and native thiol are low in acute urticaria, the levels of disulfide and IMA are high.

Dynamic thiol/disulphide homeostasis metrics as a risk factor for peripheral arterial disease.

OBJECTIVE: To examine dynamic thiol/disulphide homeostasis metrics as a novel risk factor of oxidative stress in patients with peripheral arterial disease. METHODS: One hundred patients with lower extremity peripheral arterial disease (a study group) and 100 control subjects were included in this prospective case-control study. Participants' baseline clinical characteristics and laboratory data including some oxidant/antioxidant status parameters such as albumin, ferroxidase and myeloperoxidase, and thiol/disulphide homeostasis parameters such as native thiol, total thiol and disulphide, as well as native thiol/total thiol, disulphide/native thiol and disulphide/total thiol ratios were all recorded and then compared between the groups. RESULTS: Mean albumin and ferroxidase, and median myeloperoxidase levels were found to be significantly higher in patients with the peripheral arterial disease than in control group (p = 0.045, p = 0.000 and p = 0.000, respectively). Mean native thiol and total thiol, and median disulphide levels were found to be significantly lower in the study group as compared with the control group (p = 0.000, p = 0.000 and p = 0.037, respectively). According to the results of logistic regression analysis, systolic blood pressure, ferroxidase and myeloperoxidase levels were detected to be the independent predictors of peripheral arterial disease. CONCLUSION: Our report is the first one in the literature investigating dynamic thiol/disulphide homeostasis metrics as a novel risk factor of oxidative stress in peripheral arterial disease. Dynamic thiol/disulphide homeostasis metrics may be used as a valuable risk factor of oxidative stress in patients with the peripheral arterial disease since it is readily available, easily calculated and relatively cheap.

Increased oxidative stress is associated with thiol/disulphide homeostasis in clomiphene citrate resistant polycystic ovary syndrome.

The purpose of this study was to evaluate the relation CC resistant PCOS and the thiol/disulphide homeostasis, used as a marker of OS, by measuring that exchange using a novel technique. Sixty women patients admitted to the infertility clinic were evaluated. The patients were divided into two groups. Group 1 comprised 30 infertile PCOS patients with CC resistance; Group 2 was the control group comprising 30 infertile PCOS patients with CC sensitivity. Serum total thiol (p = .024), native thiol (p = .0052), disulphide (p = .003), index 1 (p = .001), index 2 (p = .001) and index 3 (p = .001), HOMA-IR (p < .001) and free testosterone (p < .001) were statistically significant. The independent variables BMI and age effects were adjusted according to the logistic regression method with groups. Significant differences were observed between the two groups in the levels of native thiol (p* = .0042), total thiol (p* = .024), disulphide (p* = .0003), index 1 (p* = .0001) index 2 (p*= .0001), index 3 (p* = .0001), HOMA-IR (p* = .0044), insulin (p*= .032) and free testosterone (p* = .0001) values. The thiol/disulphide homeostasis viewed in favour of OS. Like a reflection of OS in the follicular endocrine microenvironment may be linked with increased thiol/disulphide homeostasis, free testosterone, insulin and HOMA-IR levels.Impact statementWhat is already known about this subject? In previous studies, thiol/disulphide homeostasis was compared between PCOS and control groups. In this study, serum thiol/disulphide homeostasis was measured in infertile PCOS patients resistant to CC for the first time.What do the results of this study add? Disulphide concentrations were significantly higher in patients with CC resistant patients thanthe control group. This shows us that more OS occurs in the CC-resistant group.What are the implications of these findings for clinical practice and further research? Thiol/disulphide homeostasis will be a guide for PCOS management in patients with CC-resistant PCOS.

Prognostic value of thiol/disulfide homeostasis in symptomatic patients with heart failure.

We aimed to examine the role of thiol/disulphide homeostasis (TDH) in heart failure and its stages and the prognosis of heart failure. A total of 140 subjects were included in the study. Total and native thiol levels were higher in the control group compared to the patient groups (p < .001). While the average disulphide/total thiol ratio was similar in groups 1 and 2, it was found to be significantly lower in the control group compared to other groups and significantly higher in group 3 compared to other groups (p < .05). Mean native thiol and total thiol levels were found lower in patients with mortality compared to surviving patients (p < .001). In ROC curve analysis, it was determined that the total thiol level had 81.8% sensitivity and 83.1% specificity, and native thiol level had 81.8% sensitivity and 84.3% specificity. We found that TDH was impaired in favour of disulphide in cases of heart failure.

Dynamic thiol/disulphide homeostasis in patients with hypertrophic cardiomyopathy.

BACKGROUND: In addition to the genetic complexity of hypertrophic cardiomyopathy (HCM), there must be other disease-modifying factors that contribute to its highly variable clinical and phenotypic expression. The authors aimed to investigate serum thiol/disulphide homeostasis as a proxy for oxidative stress using a novel automated assay in patients with HCM. METHODS: This cross-sectional study was conducted on 119 patients with HCM and 52 without HCM. The methods used to measure dynamic thiol/disulphide homeostasis as calorimetric and duplex quantities were developed in 2014. RESULTS: Median serum native thiol levels were significantly lower in patients with HCM than in those without (312.5 µmol/L [285-370 µmol/L] vs 421 µmol/L [349-469.5 µmol/L]; p < 0.001). Serum total thiol levels and disulphide levels were considerably lower than those in the control group ([844.68 ± 195.99 µmol/L vs 1158.92 ± 243.97 µmol/L; p < 0.001], [259.13 ± 65.66 µmol/L vs 375.02 ± 79.99 µmol/L; p < 0.001], respectively). Serum disulphide/native thiol ratios and disulphide/total thiol ratios were significantly lower in HCM patients than in controls (0.80 ± 0.09 vs 0.92 ± 0.05; p < 0.001 and 0.31 [0.30-0.32] vs 0.32 [0.32-0.33]; p < 0.001). Finally, reduced thiol ratios were higher and oxidized thiol ratios were significantly lower in patients with HCM than in controls. CONCLUSIONS: Despite the fact that antioxidant capacity was impaired, the extracellular environment remained in a reducing state by keeping serum disulphide/native thiol ratios low. Therefore, the authors speculate that HCM may behave similarly to tumours with respect to serum thiol-disulphide levels.

Is Thiol/Disulphide homeostasis important in prostate cancer diagnosis? / Es importante la homeostasis del Tiol/Disulfito en el diagnóstico del cáncer de próstata?

OBJECTIVES: To assess the relationship between prostate cancer and thiol/disulphide homeostasisas an important indicator of oxidative stress. METHODS: After ethics committee approval (546/2015); 388 patients aged between 46-75 years who underwent transrectal ultrasound guided prostatebiopsy in three different centers between July 2015-2016 owing to serum prostate specific antigen (PSA) levels ≥2.5 ng/ml and/or abnormal digital rectal examination were involved in this study. The plasma levels of thiol/disulphide homeostasis parameters were compared in patients with and without prostate cancer. RESULTS: The mean age of the patients was 62.9±7 years. In patients with prostate cancer (n=130, 33.5% ) the mean plasma levels of native thiol and total thiol were lower (332.9 vs 362.1 µmol/L and 363 vs 392.6 µmol/L, p=0.001). Plasma disulphide levels were not statistically different between the groups (15 vs 15.3 µmol/L, p=0.936). In prostate cancer group; patients with Gleason score ≥7 had lower plasma native thiol levels than patients with Gleason score<7 (321.3  vs 342.6 µmol/L, p=0.029) while there were no significant differences in total thiol and disulphide levels (352.3 vs 371.9 µmol/L, ptotal Thiol =0.064 and 15.5 vs 14.6 µmol/L, pdisulphide =0.933). CONCLUSIONS: Lower plasma levels of thiol in patients with prostate cancer and high Gleason score is an oteworthy result. We believe that our results should be supported by further studies.

OBJETIVOS: Establecer la relación entre cáncer de próstata y la homeostasis del tiol/disulfito como un importante indicador de estrés oxidativo.MÉTODOS: Con la aprobacion del comité ético (546/2015), 388 pacientes entre 46 y 75 años que recibieron una biopsia transrectal prostática ecoguiada en diferentes centros entre julio 2015 y 2016 por un PSA superior a 2,5 ng/ml o tacto rectal anómalo, fueron incluidos en este estudio. Los niveles plasmáticos de la homeostasis de tiol/disulfito se compararon en pacientes con y sin cáncer de próstata. RESULTADOS: La edad media de los pacientes fue de 62,9 =/- 7 años. En pacientes con cáncer de próstata (n=130, 33,5%) el nivel plasmático de tiol nativo y tiol total fue menor (332,9 vs 362,1 µmol/L y 363 vs 392,6 µmol/L, p=0,001). Los niveles de disulfito en plasma no fueron estadísticamente diferentes entre los grupos (15 vs 15,3 µmol/L, p=0,936). En el grupo con cáncer de próstata; pacientes con Gleason 7 o más tuvieron niveles menores de tiol nativo en relación a los pacientes con Gleason menor de 7 (321,3 vs 342,6 µmol/L, p=0,029), mientras no hubo diferencias en eltiol total y los disulfitos (352,3 vs 371,9 µmol/L, ptotaltiol =0,064 y 15,5 vs 14,6 µmol/L, pdisulfito =0,933). CONCLUSIONES: Niveles bajos de tiol en pacientes con cáncer de próstata y Gleason alto es un resultado notable. Creemos que nuestros resultados deberian tenerse en cuenta para otros estudios.

The evaluation of thiol/disulphide homeostasis in recurrent aphthous stomatitis.

The objective of our study was to determine thiol/disulphide homeostasis in recurrent aphtous stomatitis (RAS) patients. A prospective monocentric study was designed. Forty-three recurrent aphtous stomatitis patients and 43 healthy subjects were included to study. Venous blood samples collected and assessed with novel automatic system. Results compared statistically. Disulphide levels were found significantly higher in RAS patients than control group. There was no significant difference between native thiol and total thiol levels. Thiol/disulphide homeostasis is impaired in RAS patients in favor of disulphide levels compared with control group. To the best of our knowledge, the present study is the first examination on the correlation between thiol and disulfide homeostasis in patients with RAS.