Impairment of thiol-disulfide homeostasis in preeclampsia

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 Fetal Serum Thiol/Disulfide Homeostasis and Ischemia-Modified Albumin Levels in Fetal Distress

Aim: We investigated the association of fetal serum thiol/disulfide homeostasis and ischemia-modified albumin (IMA) levels with fetal distress (FD). Methods: Umbilical cord blood for native thiol, total thiol, disulfide, albumin, and IMA analysis was obtained from 44 pregnant women over 34 weeks gestation undergoing cesarean section due to non-acute FD, and from 61 healthy pregnant women who underwent elective cesarean section Results: Native thiol and total thiol levels were significantly lower in the FD group (p = 0.02 and p = 0.014, respectively). Although disulfide/native thiol and disulfide/total thiol ratios were higher in the FD group, the difference was statistically insignificant (p = 0.805). The IMA levels were significantly higher in the FD group (p = 0.013). Conclusion: The thiol-disulfide homeostasis shifts toward the oxidant direction during the FD pathogenesis and the increased IMA levels may be the best indicator of an underlying non-acute ischemic condition.

Maternal Serum Levels of Zinc, Copper, and Thiols in Preeclampsia Patients: a Case-Control Study

Preeclampsia is one of the leading causes of maternal mortality-morbidity, and environmental factors act as the main driving force for the development of disease in genetically lean women. Trace element levels (zinc, copper) and thiol state (total, native thiol) may affect involved risk factors and play a role in the pathogenesis. The objective of our study is to assess trace element and thiol levels in patient and control groups. A total number of 88 pregnant women (in their third trimester) included 43 preeclampsia patients and 45 normotensive pregnant women as controls. The main findings of this study were the significantly elevated copper levels and decreased thiol levels (native and total thiols) in the patient group compared to controls (p < 0.05). Disulfide levels were not statistically different between the groups (p > 0.05). In patients, the predictive cutoff value of copper was 224 μg/dL and was 1.19 for the copper/native thiol ratio. Zinc levels were not statistically different between the two groups. Correlation analysis revealed no relationship between zinc-copper and zinc-total thiol levels in patients, while a positive correlation was evident in controls (zinc-copper, p < 0.05, r = 0.425, and zinc-total thiol levels, p < 0.05, r = 0.642). Patients had marginally high ALT and AST values in the normal range, and a significant difference was found between the two groups (p < 0.05). According to these results, elevated copper levels and decreased thiol levels may have a value for early prediction. The mechanisms that may be responsible for the altered element and thiol status have been discussed here in the context of oxidative stress.

The relationship between serum thiol levels and thiol/disulfide homeostasis in women with tubal ectopic pregnancy

OBJECTIVE

The aim of this study was to investigate the thiol/disulfide homeostasis in tubal ectopic pregnancies in terms of early diagnosis of the disease.

DESIGN

A prospective case-control study was carried out between June 2017-February 2018 in the Gynaecology Department of Umraniye Medical and Research Hospital.

MATERIALS AND METHODS

A total of 42 women with ectopic pregnancy were compared with 44 healthy women who have intrauterine first trimester pregnancies. The thiol/disulfide homeostasis is evaluated with the spectrophotometric measurement method that was recently developed by Erel&Neselioglu.

RESULTS

Disulfide/native thiol and disulfide/total thiol ratios were increased (p = 0.018 and p = 0.023 respectively), while native thiol/total thiol ratios and native thiol levels were decreased in tubal ectopic pregnancy group according to control group (p = 0.023). Between control and tubal ectopic pregnancy groups no differences were measured in disulfide levels (p = 0.350). The area under curve for native thiol and total thiol were 0.937 and 0.927, respectively. The optimum cut off value for native thiol was 379.95 μmol/l with a sensitivity of 90% and specificity of 81%. The optimum cut off value for total thiol was 432.5 μmol/l had 92% sensitivity and 79% specificity.

LIMITATIONS

In the study, whether intrauterine pregnancies resulted in miscarriage or delivery can be examined.

CONCLUSION

Increased disulfide/native thiol levels, disulfide/total-thiol ratio and decreased native/total thiol ratio were found to be significantly associated with the presence of tubal ectopic pregnancy which can be useful for the early diagnosis of the disease.

Measuring the status of maternal serum thiol/disulfide couples in the diagnosis and/or the determination of the severity of late-onset preeclampsia

OBJECTIVE

Preeclampsia (PrE) is a pregnancy-related disorder. PrE affects the health of the mother and/or the fetus binomial with short and/or long-term consequences. The role of oxidant/antioxidant molecules and aberrant maternal inflammation in PrE has been documented. However, the importance of antioxidant molecules such as thiols has been poorly documented. In this research, a possible link between serum thiols levels and the diagnosis/severity of late-onset PrE (L-PrE) was investigated.

MATERIALS AND METHODS

We examined maternal serum native thiols, disulfide, total thiols levels, and their ratios in pregnant women with (n = 51) and without L-PrE (n = 50). The levels of these three markers were measured using spectrophotometric assays and compared.

RESULTS

There were significant differences in terms of serum native and total thiols levels between patients with L-PrE and healthy pregnant women (p = .001, p = .008, respectively). Disulfide levels were not different in either group (p = 0.729). There was no difference between total thiols, native thiols, disulfide concentrations, and their ratios in patients with mild (23 patients) and severe (27 patients) preeclampsia in L-PrE (p ≥ .05). A significant discriminative role of native and total thiols for the presence of L-PrE, with cutoff values of 175.86 μmol/L and 296.73 μmol/L, respectively, were revealed in ROC curve analysis.

CONCLUSIONS

Lower concentrations of total/native thiols were linked with the development of L-PrE. However, there is still a need for more clinically useful biomarkers/molecules and management strategies in PrE.

Evaluation of thiol/disulfide homeostasis in patients with gestational diabetes mellitus

This study aimed to study the dynamic thiol/disulfide homeostasis in pregnant women with gestational diabetes mellitus (GDM). Forty-five pregnant women with GDM and 45 age-matched healthy pregnancies were included in this study. Thiol/disulfide homeostasis was measured using a commercial kit (Rel Assay Diagnostics). The patients with GDM had significantly higher disulfide concentrations than healthy pregnant patients (p = .001). Besides, the GDM group had significantly higher disulfide/total thiol, disüplhide/native thiol, and native thiol/total thiol ratio than healthy pregnant patients (p = .001, p = .001 and p = .001, respectively). The significantly higher concentrations of disulfide, disulfide/total thiol, disüplhide/native thiol, and native thiol/total thiol ratio in women with GDM could be considered as the increased oxidative stress.

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.

Protective Effects of Boron on Cyclophosphamide-Induced Bladder Damage and Oxidative Stress in Rats

This study aims to investigate protective effects of boron against cyclophosphamide-induced bladder toxicity that produces oxidative stress and leads to apoptosis of the cells. In total, 24 rats were divided into 4 equal groups. The control group received saline. The 2nd experimental group received 200 mg kg of cyclophosphamide i.p. on the 4th day while the 3rd group was given only boron (200 mg kg, i.p.) for 6 days. In the 4th group, boron was given for 6 days and cyclophosphamide (200 mg kg, i.p.) was administrated on the 4th day. Twenty-four hours after the last boron or cyclophosphamide administration, rats were sacrificed under anesthesia. Bladder tissues of rats were taken for histological and immunohistochemical (apoptotic markers such as caspase-3, bcl-2, and bax) and blood was taken for the biochemical (serum total thiol, serum natural thiol, serum thiol-disulfide) analysis. Transient epithelial thinning, edema, marked inflammatory reaction, and bleeding were observed in bladders of the group that received cyclophosphamide. Also, the activity of bax and caspase-3-positive cells increased while the number of bcl-2-positive cells decreased. In the same group, serum natural thiol and total thiol levels decreased while serum disulfide levels increased, which indicates oxidative stress. On the other hand, in the boron+cyclophosphamide group pretreatment with boron protected, the bladder tissue and the number of bcl-2-positive cells increased, and bax and caspase-3-positive cells decreased, showing antiapoptotic effects of boron against cyclophosphamide-induced toxicity. In parallel with the findings of this group, native thiol and total thiol levels increased and serum disulfide levels decreased pointing out to a decreased oxidative stress. Our results indicate that boron pretreatment significantly protects rat bladder against cyclophosphamide-induced bladder damage due to its antiapoptotic and antioxidant properties.

The role of oxidative stress on subclinical atherosclerosis in premature ovarian insufficiency and relationship with carotid intima-media thickness

Objective: We aimed to investigate the relationship between oxidative stress (OS) and subclinical atherosclerosis in patients with premature ovarian insufficiency (POI), by analyzing the dynamic thiol/disulfide homeostasis (TDH) parameters as an OS marker and carotid intima-media thickness (CIMT).Materials and methods: A total of 69 women, 34 with POI and 35 healthy controls were included in this prospective cross-sectional study. TDH parameters (plasma native thiol, total thiol, disulfide, disulfide/native thiol, native thiol/total thiol, and disulfide/total thiol ratios) and CIMT were measured and compared between the two groups.Results: In primary ovarian insufficiency group, native thiol (p=.009) and total thiol (p=.010) levels were significantly decreased, and CIMT values were significantly increased (p= <.001). CIMT values were negatively correlated with native thiol (r=-0.553, p=.001) and total thiol levels (r=-0.565, p=.001); and positively correlated with age (r = 0.457, p=.007), BMI (r = 0.408, p=.017), and total cholesterol (r = 0.605, p<.001) in POI group.Conclusions: Decreased native thiol and total thiol levels demonstrate the defective anti-oxidant mechanism in POI. Negative correlation between native thiol, total thiol levels, and CIMT means the presence of abnormal anti-oxidant mechanisms may play a role in the development of subclinical atherosclerosis in patients with POI. This is a novel report on the mechanism of subclinical atherosclerosis in women with POI, which needs to be supported with further studies evaluating the pathophysiology of OS.

The relationship between oxidative stress and preeclampsia. The serum ischemia-modified albumin levels and thiol/disulfide homeostasis

Objective

Preeclampsia (PE) is a dangerous complication of pregnancy and still a major cause of maternal-fetal morbidity and mortality. Its etiology remains largely unknown, but researchers have suggested oxidative stress-mediated inflammation for the same. The purpose of this study is to investigate the relationship between oxidative stress and PE as well as the usability of oxidative stress indicators such as serum ischemia-modified albumin (IMA) levels and thiol/disulfide balance in the prediction of PE.

Materials and Methods

The study included 47 pregnant women with PE and 57 healthy pregnant women. We measured their serum IMA, native thiol, total thiol, and disulfide levels. Additionally, we determined the optimal cutoff values via the receiver operating characteristic curve analysis.

Results

There were no differences between the two groups with respect to the maternal age, body mass index, gravida, and parity. The native and total thiol levels were found to be low when the disulfide and IMA levels were high in the patients with PE (p<0.05). When the IMA level was corrected by the albumin level (IMAR), the significant difference between the two groups disappeared. We also found that the native and total thiol concentrations were correlated with the systolic and diastolic blood pressures. The optimal cut-off values calculated for the prediction of PE were as follows: 178.45 µmol/L (with sensitivity of 72% and specificity of 83%) for native thiol, 232.55 µ mol/L (with a sensitivity of 75% and specificity of 85%) for total thiol, and 29.05 µmol/L (with sensitivity of 65% and specificity of 72%) for disulfide.

Conclusion

The balance of thiol/disulfide may play a role in the pathogenesis of PE and could be used as a biological marker for PE.

Water Immersion During the Labour and Effects on Oxidative Stress

Objective: The study aims to investigate maternal serum thiol/disulfide homeostasis and ischemia-modified albumin (IMA) levels of women who were submerged during labor. Material and methods: Sixty-four pregnant women were enrolled in this study. Thirty-four women were submerged during the first stage of labor and 30 women were not. Native thiol, total thiol, disulfide, albumin, IMA, disulfide/native thiol, disulfide/total thiol and native thiol/total thiol concentrations were measured and demographic data were obtained. Results: Cord blood pH, serum disulfide levels and (disulfide/total thiol) × 100 levels were significantly lower in the water immersion group (P < 0.01, P = 0.01 and P < 0.01, respectively). Native thiol, total thiol, albumin and IMA levels were higher in the water immersion group P < 0.01, P < 0.01, P = 0.001 and P < 0.01, respectively). Conclusion: Water immersion during the first stage of labor was found to be associated with deterioration of thiol-disulfide homeostasis with respect to antioxidant status while IMA levels were higher, suggesting an ischemic condition.

Thiol/Disulfide Homeostasis in Patients with Molar Pregnancies

Introduction: We aimed to investigate serum dynamic thiol and disulfide levels in patients with molar pregnancy (MP), and compare these concentrations with those of healthy pregnant women. Materials and Methods: Forty-one patients who were diagnosed with MP and 41 gestational age-matched healthy pregnant women were included in this prospective study. MP cases were separated in two groups as complete hydatidiform mole (CHM) and partial hydatidiform mole (PHM). Demographic features and thiol/disulfide homeostasis were recorded for each woman. Results: There was a significant correlation between the decrease in the total thiol and native thiol levels in MP patients. However, no significant difference was observed between CHM and PHM groups in terms of serum disulfide levels. Conclusion: OS is increased in MPs both in complete and partial moles, as determined by thiol/disulfide analysis.

Maternal and fetal thiol/disulfide homeostasis in fetal growth restriction

PURPOSE

To evaluate thiol/disulfide homeostasis in both maternal and fetal compartment in the presence of fetal growth restriction (FGR).

MATERIALS AND METHODS

A prospective case-control study was carried out in women with FGR (n: 40) or normally growing fetus (n: 40). FGR was defined as estimated fetal weight below the 10th percentile for the gestational age. Maternal serum and fetal cord blood samples were collected from all participants and native thiol-disulfide exchanges were examined with automated method enabling the measurement of both sides of thiol-disulfide balance.

RESULTS

Native thiol, total thiol and disulfide amounts were decreased in the maternal serum and fetal cord blood of babies born to women with FGR (p < .05). The most sensitive marker was maternal native thiol (82.5, 95% confidence interval, 67.22-92.66%), while the maternal total thiol had highest specificity value (77.5, 95% confidence interval, 61.55-89.16%).

CONCLUSIONS

Maternal and fetal serum thiol/disulfide profiles may use prediction of FGR severity and its neonatal outcome.

Maternal serum TXNDC5 levels and thiol/disulfide homeostasis in preeclamptic pregnancies

Objective: To investigate thiol/disulfide homeostasis (TDH) and thioredoxin domain-containing 5 (TXNDC5) level in early and late-onset preeclampsia.Material and methods: In this cross-sectional study, 24 pregnant women with early-onset preeclampsia and 26 pregnant women with late-onset preeclampsia were compared with 30 pregnant women with no obstetric complications. The serum TXNDC5 levels and thiol/disulfide homeostasis were measured.Results: Serum TXNDC5 levels were significantly higher in the early-onset and late-onset preeclampsia groups compared with the control group (p < .05). Native thiol and total thiol levels were significantly lower in the early-onset and late-onset preeclampsia groups than control group. The disulfide levels were found as significantly high in early preeclamptic patients compared to control group (p < .05). The highest levels of TXNDC5 and the lowest levels of native thiol and total thiol were found in early-onset preeclampsia group. No significant difference was found between the patients with early onset and late onset preeclampsia regarding TXNDC5 levels and thiol/disulfide homeostasis (p > .05).Conclusion: Serum TXNDC5 levels were significantly higher in patients with early-onset and late-onset preeclampsia. The dynamic thiol/disulfide homeostasis was impaired in favor of the oxidized state in patients with preeclampsia.

Thiol-disulfide homoestasis in pregnancies with fetal growth restriction

Aim: To investigate the role of dynamic thiol-disulfide homeostasis in preeclamptic and idiopathic fetal growth restricted (FGR) pregnancies. Material and method: In this prospective case-control study, a total of 110 singleton pregnancies with FGR (study group) (51 preeclamptic and 59 idiopathic FGR's cases) were compared with 68 healthy pregnant controls at the same gestational weeks (control group). For serum disulfide-thiol homeostasis, a newly used method described by Erel and Neselioglu was used. Results: Serum native thiol and total thiol levels were lower in FGR pregnancies (285.63 ± 55.92 µmol/L, 324.41 ± 44.18 µmol/L, respectively) than control group (324.41 ± 44.18 µmol/L, 362.98 ± 51.43 µmol/L, p < .001, p = .004, respectively). In subgroup analysis, only preeclamptic FGR's have lower native and total thiol levels (254.41 ± 59.55, 324.41 ± 44.18 µmol/L, respectively) compare to both idiopathic FGR's and control's. There was no difference in native and total thiol levels with idiopathic FGR's with controls. Idiopathic FGR's have higher levels of disulfide than preeclamptic FGR's (21.72 ± 17.72 versus 16.80 ± 11.20 µmol/L). The serum albumin and total protein levels were positively and spot urine protein/creatinine ratio, 24-h urine protein levels were negatively correlated with native thiol and total thiol levels. Conclusion: The balance of thiol-disulfide homeostasis was shifted and native and total thiol levels were decreased only in preeclamptic FGR pregnancies. The serum disulfide level was increased in idiopathic FGR pregnancies compare to preeclamptic FGR pregnancies which may be a sign of oxidative stress in idiopathic FGR pregnancies with normal thiol pool.

Serum ischemia modified albumin level and its relationship with the thiol/disulfide balance in placenta percreta patients

The pathogenesis of placenta percreta (PP) is not very well known. This study was designed to analyse the oxidative stress (OS), the thiol/disulphide balance, and ischaemia-modified albumin (IMA) the women with PP. The study included 38 pregnant women with PP and 40 similarly aged healthy pregnant women in their third trimester of gestation. We measured the IMA, native and total thiols, and disulphide concentrations in the maternal sera of all of the participating women. The IMA levels were higher and the native and total thiols were lower in the PP group than in the control group. However, there was no statistical significance with respect to the thiol/disulphide balance between the two groups. The results of this study suggest that an increase in the ischaemia and OS and a decrease in the antioxidant status may contribute to the pathogenesis of PP. Impact statement What is already known on this subject? Placenta percreta (PP) is a serious complication of pregnancy. Although there are several studies investigating the pathophysiological mechanism of PP, whether the pathology results from a lack of decidua or from the over-invasiveness of trophoblasts remains controversial. The pathology of PP is poorly understood. What do the results of this study add? This prospective study has shown an increased ischaemia modified albumin (IMA) and a decreased antioxidant capacity in the patients with placenta percreta. The results from 38 women with PP suggest that the serum concentrations of IMA and the oxidative stress parameters may be able to predict PP in cases of uncertainty. What are the implications of these findings for clinical practice and/or further research? The implication of these findings shed light on understanding the pathogenesis of PP for further research.

The Effect of the 50 g Glucose Challenge Test on The Thiol/Disulfide Homeostasis in Pregnancy

AIM

A 50 g glucose challenge test (GCT) is recommended for screening all pregnant women for gestational diabetes mellitus. In this study, the effect of GCT on the thiol/disulfide balance was investigated.

METHODS

One-hundred women that underwent a 50 g GCT at 24-28 weeks of gestation (63 positive and 37 negative results) were evaluated in terms of thiol/disulfide in serum samples at test hours 0 and 1.

RESULTS

Compared to the baseline values (hour 0), after the glucose load (hour 1), the thiol and native thiol/total thiol (p < 0.0001) of the GCT-positive women were reduced whereas the values of glucose, disulfide, disulfide/native thiol, disulfide/total thiol (p < 0.0001) and total thiol increased (p = 0.018).

CONCLUSION

In GCT-positive pregnant individuals, the glucose load increases oxidative stress by changing the thiol/disulfide homeostasis. Such an effect is not observed in healthy pregnancies.

Evaluation of dynamic thiol-disulfide homeostasis in very low-birth-weighted preterms

BACKGROUND

Thiols are organic compounds containing sulfhydryl groups which exert antioxidant effects via dynamic thiol-disulfide homeostasis. The shift towards disulfides indicates the presence of oxidative environment. Thiol-disulfide homeostasis has not been evaluated in neonates. We aimed to evaluate dynamic thiol-disulfide homeostasis in preterm infants.

METHODS

Preterm infants with birth weight less than 1500 g (25-32 weeks of gestation) were included. Infants with major congenital anomaly, perinatal asphyxia, twin to twin transfusion and infants who were mechanically ventilated and nil by mouth for more than 3 days or fed with formula, had intraventricular hemorrhage ≥ grade 2 or sepsis, received blood/blood product transfusion or inotrope treatment and developed bronchopulmonary dysplasia or retinopathy of prematurity (≥ stage 3), and died were excluded thereafter. Serum thiol-disulfide homeostasis was evaluated for three times: (Baseline, first week, third week). Serum native thiol, total thiol and disulfide were measured (µmol/Lt), disulfide:native thiol, disulfide:total thiol, and native thiol:total thiol ratios were calculated. Wilcoxon's test was used to analyze the significance of change in measurements. Baseline results were analyzed for gender and mode of delivery.

RESULTS

Eighty preterm infants [1255 (1080-1415) grams] were included. Baseline values were native thiol: 209.54 ± 41.83 µmol/L; total thiol: 251.70 ± 45.82 µmol/L; disulfide: 21.08 ± 7.43 µmol/Lt; disulfide:native thiol: 10.49 ± 4.62; disulfide:total thiol: 8.45 ± 2.93; native thiol:total thiol: 83.10 ± 5.87. Thiol levels increased in each measurement, disulfide and disulfide/thiol ratios increased in the first week, decreased in the third week, ratio of native/total thiol decreased in the first week, increased in the third week. No effect of gender or mode of delivery on baseline thiol-disulfide homeostasis was detected.

CONCLUSIONS

The shift in the thiol-disulfide equilibrium towards disulfides in the first week can be attributed to subjection of infants to many oxidative insults. Furthermore, the thiol predominance in the third week could be explained by the decrease in oxidative events and increase in feeding as a supply of antioxidants. This study, displaying the levels of the dynamic thiol-disulfide homeostasis in preterm infants without obvious risks for increased oxidative stress, may provide acceptable range for thiol-disulfide homeostasis in recovering preterm infants.

The change in serum Thiol/Disulphide homeostasis after transrectal ultrasound guided prostate biopsy

Objectives

The aim of this prospective clinical study was to investigate variations in a novel oxidative stress marker (thiol/disulphide homeostasis) in men who underwent transrectal ultrasound guided prostate biopsy (TRUSB).

Materials and Methods

A total of 22 men undergoing TRUSB of the prostate were enrolled in the study. Patients with abnormal digital rectal examination and/or total prostate specific antigen (PSA) over 4ng/mL underwent TRUSB with 12 cores. Serum samples were obtained before and just after the procedure to evaluate the possible changes in thiol/disulphide homeostasis. Mean age, total PSA and free PSA, prostate volume and histopathological data were also recorded.

Results

Mean age of the study population was 65.05±8.89 years. Significant decreases in native and total thiol levels were documented after the biopsy procedure. However, serum disulphide levels and disulphide/native thiol, disulphide/total thiol and native/total thiol ratios did not significantly change after TRUSB. No correlation was observed between oxidative parameters and total PSA and free PSA levels, prostate volume and histopathology of the prostate. However, mean patient age was significantly correlated with mean native and total thiol levels.

Conclusion

Significant decreases in serum native and total thiol levels related to the prostate biopsy procedure suggest that TRUSB causes acute oxidative stress in the human body. Since our trial is the first in the current literature to investigate these oxidative stress markers in urology practice, additional studies are warranted.

Investigation of serum thiol/disulphide homeostasis in patients with abortus imminens

AIM

The aim of our study is to compare serum thiol/disulphide homeostasis of women diagnosed with abortus imminens (AI) and healthy pregnant women, and to determine whether it has a role in the pathogenesis of the disease or not.

MATERIALS AND METHODS

A total of 100 pregnant women were included in the study. The study group consisted of 50 patients with AI whereas 50 healthy pregnant women were chosen as the control group. All of the patients in the two groups were matched for age, gestational age, and body mass index. Thiol/disulphide levels were analyzed with a newly developed automated spectrophotometric method.

RESULTS

We found significantly reduced levels of native thiol (SH) (370.2 ± 35.2 μmol/l versus 397.6 ± 29.3 μmol/l) and total thiol (406 ± 37.1 μmol/l versus 434.5 ± 29.9 μmol/l), in the sera of the study group compared to the control group (p < .001). But serum levels of disulphide (SS) were statistically insignificant between the two groups (17.9 ± 5.9 μmol/l versus 18.4 ± 4.9 μmol/l, p: .612). Similarly, no significant differences were observed between the two groups in terms of SS/SH, SS/total thiol and SH/total thiol ratios (all p > .05).

CONCLUSIONS

We found a decrease in thiol levels which have antioxidant properties in patients with AI. Decreased antioxidant level in the body is thought to play a role in the etiology of AI. In this regard, further studies are needed to elucidate the potential role of dynamic thiol/disulphide homeostasis in the pathogenesis of AI.

Thiol/disulfide homeostasis in postmenopausal osteoporosis

AIM

To evaluate the impact of postmenopausal osteoporosis on thiol/disulfide homeostasis.

MATERIALS AND METHODS

A total of 75 participants were divided into two groups: Group 1 (n = 40) was composed of healthy postmenopausal women, and group 2 (n = 35) was composed of women with postmenopausal osteoporosis. Clinical findings and thiol/disulfide homeostasis were compared between the two groups.

RESULTS

The disulfide/native thiol ratio was 8.6% ± 3.6 in group 1 and 12.7% ± 8.4 in group 2 (p = 0.04). The disulfide/native thiol percent ratio was significantly higher in group 2 after adjustment for the years since menopause and age (p < 0.05). The native thiol/total thiol percent ratio was 85.6% ± 4.8 in group 1 and 73.8% ± 24.9 in group 2 (p = 0.01). The native thiol/total thiol percent ratio was significantly lower in group 2 after adjustment for the years since menopause and age (p < 0.05).

CONCLUSION

Thiol/disulfide homeostasis shifted to the disulfide side independent of age and years since menopause in postmenopausal osteoporosis.

Immunology of hepatic diseases during pregnancy

The mother's immune system has to adapt to pregnancy accepting the semi-allograft fetus and preventing harmful effects to the developing child. Aberrations in feto-maternal immune adaptation may result in disease of the mother, such as liver injury. Five pregnancy-associated liver disorders have been described so far, however, little is known concerning immune alterations promoting the respective disease. These liver disorders are pre-eclampsia, hemolysis, elevated liver enzymes, low platelet count (HELLP), acute fatty liver, hyperemesis gravidarum, and intrahepatic cholestasis of pregnancy. On the other hand, pre-existing autoimmune liver injury of the mother can be affected by pregnancy. This review intends to summarize current knowledge linking feto-maternal immunology and liver inflammation with a special emphasis on novel potential biomarkers.