Evaluation of maternal serum thiol and ischemia-modified albumin levels in cases of placenta previa: A case-control study in a tertiary center.

AIM: We aim to compare the maternal serum thiol and ischemia-modified albumin (IMA) levels between pregnant women with placenta previa and those with uncomplicated pregnancies and to determine whether changes in these levels were useful in predicting cases of abnormally invasive placenta (AIP). METHODS: Fifty-five pregnant women diagnosed with placenta previa according to the diagnostic criteria (case group) were compared to 100 women with uncomplicated pregnancies of similar demographic characteristics (control group). The patients with placenta previa were further divided into two subgroups: AIP (n = 20) and placenta previa without invasion (n = 35). The maternal serum native thiol, total thiol, disulfide, and IMA levels of the groups were evaluated. RESULTS: The native thiol, total thiol, and IMA values were significantly lower in the case group than in the control group (p < 0.001). The disulfide values were similar between the study and control groups (p = 0.488). When the AIP and placenta previa without invasion groups were compared, the levels of native thiol, total thiol, disulfide, and IMA were similar (p > 0.05). CONCLUSIONS: Maternal serum thiol and IMA levels were lower in placenta previa cases compared to the control group. However, these parameters were not useful in predicting AIP cases.

Evaluation of IL-10, IFN-γ, and thiol-disulfide homeostasis in patients with drug-resistant epilepsy.

AIM: This study compared dynamic thiol-disulfide homeostasis (an oxidative stress marker), anti-inflammatory interleukin-10 (IL-10) levels, and proinflammatory interferon gamma (IFN-γ) levels in drug-resistant epilepsy patients with those in patients with well-controlled epilepsy and healthy controls. METHOD: This prospective cross-sectional study enrolled 89 people: 27 with drug-resistant epilepsy, 30 with well-controlled epilepsy, and 32 healthy controls matched in demographic characteristics. RESULTS: The mean serum IL-10 levels were significantly lower and the mean serum IFN-γ levels significantly higher in the drug-resistant epilepsy patients compared to the well-controlled epilepsy and healthy control groups. The mean serum native thiol (SH) and total thiol (TT) levels were significantly lower, and the disulfide (SS) levels were significantly higher in the drug-resistant group than in the other two groups. CONCLUSIONS: The significant differences in thiol-disulfide homeostasis and IL-10 and IFN-γ levels in the drug-resistant epilepsy group suggest that these markers indicate a poor prognosis in epilepsy.

An Evaluation of Oxidative Stress With Thiol/Disulfide Homeostasis in Patients With Persistent Allergic Rhinitis.

BACKGROUND: We evaluated the efficacy of medical treatment on thiol-disulfide balance despite ongoing allergic stimulation. METHODS: The research design was a prospective observational study that included 35 persistent allergic rhinitis (AR) patients. All patients who were diagnosed with persistent AR were included. A skin prick test was applied to all patients, and the Sino-nasal Outcome Test-22 was used to evaluate sinonasal symptoms. Thiol/disulfide homeostasis balance parameters were measured using a novel automatic and spectrophotometric method and compared statistically. Serum total thiol (TT), native thiol (SH), disulphide (SS), disulphide/native thiol (SS/SH), disulphide/total thiol (SS/TT), and native thiol/total thiol (SH/TT) ratios were measured after the second month of the treatment. RESULTS: The 35 patients included 20 (58%) females and 15 (42%) males. The mean age of the patients was 33.17 ± 9.9 years. Disulphide, SS/SH, and SS/TT ratios decreased significantly after the treatment (P < .05), while SH and SH/TT increased significantly (P < .05). The mean SH measurement increased significantly in the second month (P = .001), but TT mean measurements showed no difference after the treatment (P = .058). The mean SS measurements, on the other hand, decreased significantly in the second month (P = .003). CONCLUSION: Thiol/disulfide homeostasis may be used as a marker to evaluate the efficacy of persistent AR treatments. After the treatment, the increase in SH levels suggested the decrease in oxidative stress, even though allergen exposure continued.

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.

Alteration of serum biomarkers in patients with hypertrophic cardiomyopathy with and without atrial fibrillation.

Aim: We sought to determine the relationship between presence of atrial fibrillation (AF) and serum biomarkers, including native thiol (antioxidant), disulphide/native thiol ratio, Hs-CRP and high-sensitivity Troponin-I (Hs-TnI) in hypertrophic cardiomyopathy (HCM). Materials & methods: We enrolled consecutive 121 HCM outpatients without AF and 40 HCM outpatients with AF. A 12-lead electrocardiogram, transthoracic echocardiography and 24/48-h ambulatory rhythm monitoring were performed for all patients. Fasting venous blood samples were taken from all study patients to measure serum thiol-disulphide homeostasis, Hs-CRP and Hs-TnI. Results: Serum-native thiol was lower and disulphide/native thiol ratio was more oxidized in HCM patients with AF (p < 0.001). Also, HCM patients with AF had higher Hs-TnI and Hs-CRP than no-AF HCM patients. Disulphide/native thiol ratio, serum-native thiol, age, NYHA functional class≥III, and advanced diastolic dysfunction were independently associated with the presence of AF in HCM. Conclusion: In addition to clinical and echocardiographic findings, oxidative stress is also associated with AF in HCM patients.

Effects of antiviral drug therapy on dynamic thiol/disulphide homeostasis and nitric oxide levels in COVID-19 patients.

The novel coronavirus disease 2019 (COVID-19) has led to a serious global pandemic. Although an oxidative stress imbalance occurs in COVID-19 patients, the contributions of thiol/disulphide homeostasis and nitric oxide (NO) generation to the pathogenesis of COVID-19 have been poorly identified. Therefore, the aim of this study was to evaluate the effects of antiviral drug therapy on the serum dynamics of thiol/disulphide homeostasis and NO levels in COVID-19 patients. A total of 50 adult patients with COVID-19 and 43 sex-matched healthy control subjects were enrolled in this prospective study. Venous blood samples were collected immediately on admission to the hospital within 24 h after the diagnosis (pre-treatment) and at the 15th day of drug therapy (post-treatment). Serum native thiol and total thiol levels were measured, and the amounts of dynamic disulphide bonds and related ratios were calculated. The average pre-treatment total and native thiol levels were significantly lower than the post-treatment values (P < 0.001 for all). We observed no significant changes in disulphide levels or disulphide/total thiol, disulphide/native thiol, or native thiol/total thiol ratios between pre- and post-treatments. There was also a significant increase in serum NO levels in the pre-treatment values when compared to control (P < 0.001) and post-treatment measurements (P < 0.01). Our results strongly suggest that thiol/disulphide homeostasis and nitrosative stress can contribute to the pathogenesis of COVID-19. This study was the first to show that antiviral drug therapy can prevent the depletion in serum thiol levels and decrease serum NO levels in COVID-19 patients.

Plasma thiol and disulphide levels and their relationship with left ventricular systolic functions: A propensity score matching analysis.

OBJECTIVE: Left ventricular (LV) systolic function measured through LV ejection fraction (LVEF) has prognostic implications in patients with cardiac and non-cardiac conditions. The balance of thiol and disulphide levels reflects oxidative status in the body. In this study, we aimed to investigate the relationship between plasma thiol and disulphide levels, and LVEF calculated by transthoracic echocardiography (TTE). METHODS: This retrospective study included 1,048 patients referred for TTE examination and biochemical analyses, including plasma thiol and disulphide levels. After the application of exclusion criteria, the remaining 611 patients were included in the statistical analysis. Patients were classified into two groups, namely normal LVEF (n-LVEF) (n=446) and low LVEF (l-LVEF) (n=165) according to a cut-off level of LVEF 50%. To reduce sample selection bias and adjust for the influence of differences in patient characteristics on LVEF and oxidative status, 1: 1 propensity score matching analysis was applied. RESULTS: Propensity score matching analysis yielded 125 patients in both groups with comparable demographics, medications, and blood parameters. Native thiol and total thiol levels were lower in l-LVEF patients than in n-LVEF patients (p<0.001 for both), whereas disulphide levels were higher in l-LVEF group (p=0.008). Native thiol (r=0.384, p<0.001), total thiol (r=0.35, p<0.001), and disulphide levels (r=-0.129, p=0.004) significantly correlated with LVEF. CONCLUSION: Plasma thiol levels decrease and disulphide levels increase suggesting the presence of oxidative stress in patients with l-LVEF. Significant correlation between oxidative stress and LVEF sheds light about the possible pathogenetic role of thiol and disulphide in heart failure.

Thiol-disulfide homeostasis and ischemia-modified albumin as a marker of oxidative stress in patients with sarcopenia.

AIM: Sarcopenia is characterized by progressive and generalized loss of skeletal muscle mass and strength. Chronic inflammatory conditions and increased oxidative stress are in the pathogenesis of sarcopenia. Our aim was to evaluate the relationship between sarcopenia and thiol-disulfide homeostasis and ischemia-modified albumin levels as an oxidative stress marker. METHODS: Patients aged ≥65 years were recruited in this study. Sarcopenia was diagnosed according to the European Working Group on Sarcopenia in Older People criterion. Total thiol, native thiol, disulfide and ischemia-modified albumin levels were measures according to clinical and laboratory features. Patients were divided into two groups according to their sarcopenia presence; thiol-disulfide homeostasis and ischemia-modified albumin levels were evaluated between these groups. RESULTS: Overall, 94 patients were analyzed. The mean age was 75.0 ± 6.71 years. A total of 39% of the patients were diagnosed as probable sarcopenia, 3.2% had sarcopenia, 6.4% had severe sarcopenia and 51.1% were diagnosed as normal. The levels of native thiol, total thiol, disulfide level and disulfide-native thiol, native thiol-total thiol and disulfide-total thiol ratios were similar in patients with sarcopenia when compared with the control group. In addition, there were no differences between albumin and ischemia-modified albumin levels. In univariate regression analysis, handgrip strength was found to be an independent predictor of native thiol and total thiol, and disulfide levels. CONCLUSION: This is the first study in the literature that evaluates the thiol-disulfide homeostasis and ischemia-modified albumin levels in sarcopenic older patients. Long-term studies are warranted to confirm the relationship between oxidative stress markers and sarcopenia. Geriatr Gerontol Int 2021; 21: 584-589.

Erythrocyte reduced/oxidized glutathione and serum thiol/disulfide homeostasis in patients with rheumatoid arthritis.

BACKGROUND: Chronic inflammation and oxidative stress are the most known mechanisms in Rheumatoid Arthritis (RA) pathophysiology, which is still not fully elucidated. In this study, we evaluated oxidative status by determining intracellular reduced/oxidized glutathione (GSH/GSSG) homeostasis and serum thiol/disulfide (SH/SS) homeostasis in RA patients. METHODS: A total of 152 RA patient and 89 healthy controls were included in the study. RA patients were subdivided according to disease activity score-28 (DAS-28) as active RA and remission RA. Intracellular GSH/GSSG and serum SH/SS homeostasis parameters were analyzed. RESULTS: Median (1st-3rd quartile values) SS/SH and GSSG/GSH percent ratio levels were significantly higher in RA patients (6.94 (6.02-8.54) and 69.8 (44.05-85.29); respectively) compared to controls (4.62 (4.15-5.46) and 34.9 (22.43-62.2); respectively) (p < 0.05 for all). SS/SH and GSSG/GSH percent ratio levels were significantly higher in active RA patients when compared to remission RA patients and controls (p < 0.05 for all). SS/SH and GSSG/GSH percent ratios were significantly increased in remission RA group compared to controls (p < 0.05 for all). DAS28 scores were positively correlated with SS/SH and GSSG/GSH percent ratios (rho = 0.259 and 0.296; respectively). CONCLUSIONS: These findings suggest that active intracellular and extracellular thiol group oxidation process might play a role in RA pathogenesis and further work in these areas may be warranted to show potential value of evaluating intracellular GSSG/GSH and serum SH/SS balances together in disease monitoring.

Comparison of serum human Klotho levels and thiol/disulfide homeostasis in women with polycystic ovary syndrome and in healthy women.

OBJECTIVES: Women with polycystic ovary syndrome (PCOS) have an increased cardiometabolic risk. Similarly, it was previously shown that atherosclerotic and cardiovascular risk is increased in the general population with lower serum Klotho levels. The aim of this study was to investigate the lotho and thiol/disulfide levels in women with non-obese PCOS compared to healthy controls and also to investigate the relationship of serum Klotho and thiol/disulfide homeostasis with cardiometabolic risk factors. MATERIALS AND METHODS: In this prospective case control study, human serum alpha Klotho levels and thiol/disulfide homeostasis of women with PCOS aged between 19-33 were compared to their age and BMI matched non - PCOS healthy controls. In addition, the correlation of these molecules with other metabolic markers/measurements were also investigated. RESULTS: Metabolic parameters such as mean waist circumference, lipid accumulation product, visceral adiposity index, fasting insulin, homeostasis model assessment of insulin resistance and triglyceride values were higher in the PCOS group (p = 0.038, p = 0.008, p = 0.001, p = 0.001, p = 0.002 and p = 0.002, respectively) compared to controls. However, mean serum Klotho and native thiol levels (respectively p < 0.0001 and p = 0.038) were lower compared to controls. Correlation analysis revealed that serum Klotho levels were negatively correlated with BMI, waist circumference, disulphide/total thiol, disulphide/native thiol, HOMA-IR and LAP-index. CONCLUSIONS: Findings of decreased serum Klotho and native thiol values of the PCOS group compared to controls and the negative correlation of serum Klotho levels with metabolic markers supports the idea that decreased Klotho may be another mechanism by which cardiovascular risk is increased in women with PCOS.

An investigation into the clinical efficacy of thiol/disulfide hemostasis and ischemia-modified albumin in cases of gallbladder perforation.

BACKGROUND: In the presence of advanced age and comorbidities, patients with gallstones may face gangrenous and perforated cholecystitis during their follow-up. In the literature, dynamic thiol/disulfide homeostasis has been shown to play an important role in detoxification, antioxidant protection, regulation of enzymatic reactions, and apoptosis and cellular signaling mechanisms. In this study, we aimed to evaluate the efficacy of IMA and thiol/disulfide homeostasis in the preoperative diagnosis of patients with cholelithiasis, acute/chronic cholecystitis, and perforated gallbladder. METHODS: Sixty-six patients that presented to the General Surgery Clinic of Ankara City Hospital for a cholecystectomy operation between February 2019 and May 2020 were included in this study. The patients were divided into three groups depending on the condition for which they were scheduled for surgery: cholelithiasis, cholecystitis, and perforated gallbladder. The demographic data, history of cholecystitis, chronic disease, white blood cell (WBC), amylase, lipase and liver function tests (AST and ALT) were recorded before the operation. Gallbladder appearance was evaluated using hepatobiliary ultrasonography. The duration of surgery, pericholecystic adhesions, hospital stay, body mass index (BMI), postoperative complications, and pathology results of specimens were recorded. In addition, thiol/disulfide and IMA values were analyzed in the blood samples taken from the patients preoperatively. RESULTS: The mean native thiol and total thiol values of the patients with an adhesion score of 0 were significantly higher than those with an adhesion score value of 1, 2 or 3. In addition, the disulfide, disulfide/native thiol, native thiol/total thiol and IMA values of the cases with an adhesion score of 2 or 3 were significantly higher than those with an adhesion score of 0. The native thiol and total thiol averages of the patients with normal cholecystectomy were higher than the others. The disulfide, native thiol/total thiol and IMA averages of those who underwent cholecystectomy due to a perforated gallbladder were also higher than the other groups. The mean preoperative WBC of the patients who underwent cholecystectomy due to a perforated gallbladder was also significantly higher than the other groups. Lastly, the native thiol and total thiol values had a statistically significant negative correlation with age, operation time, and hospital stay, and a statistically significant positive relationship with BMI. CONCLUSION: We consider that in the preoperative diagnosis of the perforated gallbladder, the evaluation of thiol/disulfide hemostasis and IMA parameters can be used as an effective and reliable method to predict intraoperative difficulties.

Relationship between thiol, disulphide volume and contrast-induced nephropathy in acute coronary syndrome patients treated with percutaneous coronary intervention.

BACKGROUND: This study aimed to evaluate thiol disulphide volume for the risk of contrast-induced nephropathy (CIN) in patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI). METHODS: A total of 638 patients with ACS were enrolled in the study. CIN was defined as an increase in serum creatinine level of ≥0.5 mg/dL or ≥25% above baseline within 72 h after the procedure. Patients were divided into two groups: patients with and without CIN. Demographics, clinical risk factors, angiographic and laboratory parameters, CIN incidence, thiol, disulphide, and CHA2DS2-VASc score were compared between the two groups. RESULTS: Native thiol, total thiol, and disulphide at baseline were significantly lower in patients who developed CIN compared to those who did not. Also, the CHA2DS2-VASc score was found to be higher in patients with CIN than those without CIN. In receiver operating characteristic analysis showed that at a cutoff of <342.1, the value of native thiol exhibited 82% sensitivity and 80% specificity for detecting CIN. Total thiol< 383.1 calculated on admission had an 80% sensitivity and 80% specificity in predicting CIN. CONCLUSION: Our study suggested that the thiol disulphide volume on admission was independently associated with the development of CIN after PCI in patients with ACS.

Analysis of the Soil Fumigant, Dimethyl Disulfide, in Swine Blood by Dynamic Headspace Gas Chromatography-Mass Spectroscopy.

Plant parasites and soilborne pathogens directly reduce the overall yield of crops, vegetables, and fruits, negatively impacting the market demand for these products and their net profitability. While preplant soil fumigation helps maintain the consistent production quality of high-value cash crops, most soil fumigants are toxic to off-target species, including humans. Dimethyl disulfide (DMDS) has recently been introduced as a relatively low toxicity soil fumigant. Although DMDS exhibits low toxicity compared to other soil fumigants, it is volatile and exposure can cause eye, nasal, and upper respiratory tract irritation, skin irritation, nausea, dizziness, headache, and fatigue. While there is one analysis method available for DMDS from biological matrices, it has significant disadvantages. Hence, in this study, a dynamic headspace gas chromatography-mass spectroscopy (DHS-GC-MS) method was developed for the analysis of DMDS in swine whole blood. This method is highly sensitive and requires only three steps: 1) acid denaturation, 2) addition of internal standard, and 3) DHS-GC-MS analysis. The method produced a wide linear range from 0.1 - 200 µM with an excellent limit of detection of 30 nM. Intra- and interassay accuracy (100±14% and 100±11%, respectively) and precision (<5% and <6% relative standard deviation, respectively) were also excellent. The method worked well to quantify the DMDS levels in the blood of dimethyl trisulfide (DMTS)-treated swine (i.e., DMDS is a byproduct of DMTS treatment) with no interfering substances at or around the retention time of DMDS (i.e., 2.7 min). This simple, rapid, and extremely sensitive method can be used for the quantification of DMDS levels in blood to verify exposure to DMDS or to monitor levels of DMDS following DMTS treatment (e.g., for cyanide poisoning).

Impaired Thiol/Disulfide Homeostasis in Children Diagnosed with Autism: A Case-Control Study.

Although genetic factors occupy an important place in the development of autism spectrum disorder (ASD), oxidative stress and exposure to environmental toxicants have also been linked to the condition. The aim of this study was to examine dynamic thiol/disulfide homeostasis in children diagnosed with ASD. Forty-eight children aged 3-12 years diagnosed with ASD and 40 age- and sex-matched healthy children were included in the study. A sociodemographic data form was completed for all the cases, and the Childhood Autism Rating Scale (CARS) was applied to the patients. Thiol/disulfide parameters in serum were measured in all cases and compared between the two groups. Mean native thiol, total thiol concentrations (µmol/L), and median reduced thiol ratios were significantly lower in the ASD group than in the control group (p = 0.001 for all). Median disulfide concentrations (µmol/L), redox potential, and median oxidized thiol ratios were significantly higher in the ASD group than in the control group (p = 0.001, p = 0.001, and p = 0.001, respectively). ROC analysis revealed that area under the curve (AUC) values with "excellent discriminatory potential," for native thiol, total thiol, the reduced thiol ration, the oxidized thiol ratio, and redox potential and with "acceptable discriminatory potential" for disulfide were significantly capable of differentiating individuals with ASD from healthy individuals. No correlation was determined between the severity of autism and laboratory parameters. Impaired dynamic thiol/disulfide homeostasis was observed in children with ASD, suggesting that dynamic thiol/disulfide homeostasis in serum may be of diagnostic value in autism.

Urotensin-II, oxidative stress, and inflammation increase in hypertensive and resistant hypertensive patients.

Objective: Hypertension is a multi-factorial process prevalent in developed as well as in developing countries. Urotensin-II, different antioxidants, free radicals, and inflammatory biomarkers play an essential role in the cardiovascular system. The aim of this study is to investigate Urotensin-II, oxidative stress, and inflammation markers in normotensive, hypertensive, and resistant hypertensive patients. Methods: Fifty resistance hypertensive (rHT) patients, 50 hypertensive patients, and 50 age gender matched normotensive controls (NT-control) were enrolled. Urotensin-II (UII), total oxidant status (TOS), total antioxidant status (TAS), native thiol (NT), total thiol (TT), disulfide (DIS), interleukin 1 beta (IL1ß), interleukin 6 (IL6), tumor necrosis factor-alpha (TNFα), high sensitive c reactive protein (hsCRP), high-density lipoprotein (HDL) low-density lipoprotein (LDL), and total cholesterol (TC) were evaluated. Results: Serum levels of UII, IL1ß, IL6, TNFα, DIS, TOS, and OSI were found higher in rHT and HT as compared to NT-control (p < .001). On the contrary, serum levels of TT, TAS, and NT were lower in rHT and HT as compared to NT-control (p < .001). While TC, hsCRP, TOS, OSI, UII, IL1ß, IL6, and TNFα levels increase from HT to rHT group (p < .001); TAS and NT levels decrease from HT to rHT group (p < .001). Conclusions: UII levels, oxidative stress, and inflammation are higher in rHT and HT, while antioxidants and thiol levels are lower than the NT-control. Our study clearly showed that rHT and HT are more susceptible to impaired states of antioxidants, oxidative stress, and free radicals.

An Investigation of the Dynamic Thiol/Disulfide Homeostasis, As a Novel Oxidative Stress Plasma Biomarker, in Children With Autism Spectrum Disorders.

We aimed to investigate the role of impaired oxidant-antioxidant homeostasis on the etiopathogenesis of autism with a novel oxidative stress (OS) marker, dynamic thiol/disulfide homeostasis (DTDH), and relationship between the symptom severity and markers. A total of 60 children with ASD aged 3-10 years and 54 unaffected children were investigated for the plasma DTDH parameters. A sociodemographic-data form, K-SADS-PL, Childhood Autism Rating Scale, Abnormal Behavior Checklist, Autism Behavior Checklist, and a developmentally appropriate IQ test were administered to all participants. Distortion of DTDH to the OS-side in the autism group was determined with lower plasma levels of native and total thiol, in contrast to a higher disulfide and thiol oxidation-reduction ratio. However, biomarkers had no correlation with the symptom severity of autism. Cutoff values for each parameter on the ROC curve might be useful to predict ASD and each DTDH biomarker was detected as an independent predictor of ASD. The present study demonstrated a disturbed redox status and absence of an expected compensatory increase in antioxidant response in a pediatric sample of ASD by measuring dynamic oxidation/reduction shifts with a novel, practical and reproducible analytical technique, and contributes to data regarding oxidative hypothesis on autism and raises the question of the place of antioxidants in autism treatment. Our results may suggest predictive usefulness of the plasma DTDH biomarkers in ASD, despite the study being conducted with a modestly small sample size that makes further research with a larger replication sample necessary to substantiate the findings. LAY SUMMARY: Dynamic thiol/disulfide homeostasis is a novel plasma marker used to determine the oxidative stress which is a natural result of disequilibrium between the oxidants and antioxidants in the human body. There is increasing interest regarding a central biological linking role of oxidative stress among the other etiological factors of autism. Our findings on the disturbed plasma dynamic thiol/disulfide homeostasis in children with autism and the absence of an expected antioxidant response against increased oxidative stress supports the data concerning the role of oxidative stress on the etiology of autism and the need of further research on the place of antioxidants in autism treatment.

Dynamic thiol/disulfide homeostasis as oxidative stress marker in diabetic ketoacidosis

Background/aim: The aim of present study was to investigate the dynamic thiol/disulfide homeostasis as oxidative stress marker in diabetic ketoacidosis (DKA). Materials and methods: A total of 77 participants consisting of 32 patients with DKA and 45 healthy volunteers were included in the study. Thiol/disulfide homeostasis (TDH) [total thiol-native thiol/disulfide changes] were measured in both groups (patient group and control group) using a brand new 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, native thiol, and disulfide levels in blood were found to be low. The levels of total thiol (P < 0.001) and native thiol (P < 0.001 ) were significantly lower in patients with DKA than in the control group. At the same time, the level of disulfide was nonsignificantly lower in the patient group than the control group (P = 0.388). The level of IMA was higher in the patient group than in the control group (P < 0.001). Conclusion: The total thiol, native thiol, and disulfide levels in DKA decrease in favor of oxidative stress.

Thiol/disulfide homeostasis in retinitis pigmentosa patients.

PURPOSE: This research is aimed at determination of total oxidant status, total antioxidant status, serum thiol-disulfide, catalase, albumin, ischemia-modified albumin, and ceruloplasmin in patients suffering from retinitis pigmentosa and drawing a comparison with these parameters determined from healthy controls. METHODS: The study involved 35 patients of retinitis pigmentosa and 33 controls who were healthy individuals of comparable gender and age. Native thiol, total thiol, disulfide concentration, disulfide/native thiol, disulfide/total thiol, native thiol/total thiol ratios, total oxidant status, total antioxidant status, catalase, ceruloplasmin, albumin, and ischemia-modified albumin were determined from peripheral blood samples and comparison was drawn between the measurements of retinitis pigmentosa and controls. RESULTS: The two groups were similar in gender and age distributions. It was found that retinitis pigmentosa group demonstrated greater total oxidant status, ischemia-modified albumin, and disulfide concentrations as compared to controls (p < 0.001). However, total antioxidant status, catalase, native thiol, total thiol, albumin, and ceruloplasmin of the two groups did not show statistically significant difference (p > 0.05). Moreover, disulfide/total thiol and disulfide/native thiol ratios of the retinitis pigmentosa group were significantly greater in comparison to controls (p < 0.05). CONCLUSION: The researchers reached the conclusion that thiol oxidation in retinitis pigmentosa patients caused the dynamic thiol/disulfide homeostasis to shift toward the generation of disulfide. This is a novel research that involves analysis of thiol/disulfide homeostasis in retinitis pigmentosa patients using a novel automated assay. The researchers identified the cause for persistent oxidative stress and damage reported in retinitis pigmentosa patients. Still, future research is required for analysis of progression of antioxidant-oxidant state through various retinitis pigmentosa stages.

A SERS quenching method for the sensitive determination of insulin.

In this work, we utilise the disulphide bond structure of insulin and a new benzothiazole Raman probe for the detection of human insulin using surface-enhanced Raman spectroscopy (SERS). The disulphide bond structure of the insulin was reduced to generate free sulfhydryl terminal groups. When reacted with benzothiazole-functionalised gold nanoparticles, the reduced protein desorbs the Raman probe and causes its Raman signal intensity to quench. Using this approach, insulin was quantified in the concentration range of 1 × 10-14 -1 × 10-8 M by SERS quenching. The limit of quantification of insulin by the SERS quenching method was found to be 1 × 10-14 M (0.01 pM or 58 pg/L), which satisfies the requirements for monitoring its blood concentration in patients. Because many proteins and peptides have disulphide bonds in their molecular structures, the new SERS quenching method has a strong potential for the rapid determination of ultralow concentrations of proteins in formulations and biological fluids.

Efficacy of Thiol Disulfide Homeostasis and Ischemia Modified Albumin Values in Estimating the Degree of Difficulty for Laparoscopic Cholecystectomy.

AIM: The aim of this study was to investigate the efficacy of thiol disulfide homeostasis and Ischemia Modified Albumin (IMA) values in predicting the technical difficulties that might be encountered during laparoscopic cholecystectomy. MATERIALS AND METHODS: The study included 65 patients who underwent laparoscopic cholecystectomy due to cholelithiasis at the General Surgery Clinic of Ankara Numune Training and Research Hospital. All patients' demographic data, previous history of cholecystitis, a history of chronic illness, preoperative white blood count (WBC), liver function tests (AST, ALT), amylase and lipase levels, intra-operative adhesion score, the ultrasonographic appearance of gall bladder, duration of hospital stay, duration of operation, thiol disulfide and IMA values were evaluated. RESULTS: Native thiol and total thiol averages were higher in patients without a history of cholecystitis, and on the other hand, disulfide, disulfide/native thiol rate, disulfide/total thiol rate, native thiol/total thiol rate and IMA averages were higher in patients with a history of cholecystitis. While there was a statistically significant negative correlation between native and total thiol values and age, duration of surgery and duration of hospital stay; IMA, disulfide, disulfide/Total thiol, Native/Total thiol and disulfide/Native thiol rates were higher in older patients with a longer duration of surgery and hospital stay. In addition, preoperative IMA, disulfide, disulfide/Total thiol, Native/Total thiol and disulfide/Native thiol were observed to increase as the degree of intraoperative pericholecystic adhesion increased. CONCLUSION: We believe that the evaluation of thiol disulfide homeostasis and IMA parameters prior to laparoscopic cholecystectomy can be used as an effective method for predicting intraoperative difficulties.