Accelerated kynurenine pathway downregulates immune activation in patients with axial spondyloarthritis.

Various studies reported that the kynurenine (Kyn) pathway plays a pivotal role in regulating the balance between activation and inhibition of the immune system. Proinflammatory cytokines can accelerate the Kyn pathway by altering indoleamine (2, 3)- dioxygenase (IDO) allosteric enzyme activity. Excessive cytokine release and immune system activation have essential roles in the pathogenesis of axial spondyloarthritis (axSpA). We aimed to investigate the relationship of the Kyn pathway with proinflammatory cytokines and with the severity of the disease in patients with axSpA. The study included 104 patients with axSpA and 54 healthy volunteers. The severity of the disease was determined by Bath Ankylosing Spondylitis Disease Activity Index (BASDAI). The Kyn pathway was evaluated by IDO activity calculated with Kyn/Tryptophan (Trp) ratio. Plasma Trp and Kyn concentrations were measured with tandem mass spectrometry. Serum IL 17/23 and IFN-γ concentrations were measured with ELISA. These groups were compared in terms of IDO, IL-17, IL-23, IFN-γ, and BASDAI. Plasma IDO activity was significantly increased, however, serum IL-17, IL-23, and IFN-γ levels were significantly decreased in patients compared to healthy volunteers. While IFN-γ was positively correlated with the severity of the disease (p = 0.02), it also had a significant inverse correlation with IDO activity (p < 0.001). However, these correlations are weak. As a result of this study, the Kyn pathway is accelerated and proinflammatory cytokine levels are decreased in patients with axSpA. All of these results with an indirect weak negative association between high IDO and low disease activity suggest that an accelerated Kyn pathway may limit the immune system activation in axSpA disease.

Renal tubular and glomerular estrogen receptor ß levels are lower in lupus nephritis than in familial Mediterranean fever-associated renal amyloidosis.

BACKGROUND: Estrogen has been thought to play an essential role in the disease pathogenesis of systemic lupus erythematosus, which is 9-10 times more prevalent in the female population. It has been shown that irregular estrogen/estrogen receptor signaling pathways may contribute to the pathophysiology of various renal diseases. In this study, we compared renal estrogen receptors between lupus nephritis, familial Mediterranean fever-associated renal amyloidosis, ANCA-associated nephritis, and intact kidney to investigate their role in the pathophysiology of renal diseases. METHODS: This study was designed as a retrospective cohort study. Thirty systemic lupus erythematosus patients with lupus nephritis, 12 familial Mediterranean fever amyloidosis and 10 ANCA-associated glomerulonephrites, and 14 individuals with normal renal histology were included in the study. RESULTS: Tubular estrogen receptor ß expression score was found to be significantly higher in the familial Mediterranean fever [5 (1-8)] group than in the lupus nephritis [0 (0-1)] (B = 1.385, OR = 3.996, CI %95 = 1.805-8.846, p = .001) and ANCA [4 (1-6.5)] (B = -1.431, OR = 0.239, CI 95% = 0.093-0.614, p = .003) groups. A significant correlation was found between serum creatinine values and tubular estrogen receptor ß expression score (OR = 0.565, CI 95% = 0.622-1.402, p < .0001). In ANCA-associated glomerulonephritis, a significant relationship was found between fibro cellular crescents in renal biopsy and glomerular estrogen receptor ß expression score (OR = 0.247, CI 95% = 0.11-0.999, p = .045) and tubular estrogen receptor ß expression score (OR = 0.282, CI 95% = -0.180-2.812, p = .026). CONCLUSIONS: This study showed that tubular estrogen receptor ß expression score was elevated in familial Mediterranean fever amyloidosis and correlated with serum creatinine levels and renal crescents.

Investigation of the effects of pneumatic tube transport system on routine biochemistry, hematology, and coagulation tests in Ankara City Hospital.

OBJECTIVES: Academics are far from a consensus regarding the effects of pneumatic tube system (PTS) delivery on sample integrity and laboratory test results. As for the reasons for conflicting opinions, each PTS is uniquely designed, sample tubes and patient characteristics differ among studies. This study aims to validate the PTS utilized in Ankara City Hospital for routine chemistry, coagulation, and hematology tests by comparing samples delivered via PTS and porter. METHODS: The study comprises 50 healthy volunteers. Blood samples were drawn into three biochemistry, two coagulation, and two hemogram tubes from each participant. Each of the duplicate samples was transferred to the emergency laboratory via Swiss log PTS (aka PTS-immediately) or by a porter. The last of the biochemistry tubes were delivered via the PTS, upon completion of coagulation of the blood (aka PTS-after). The results of the analysis in these groups were compared with multiple statistical analyses. RESULTS: The study did not reveal any correlation between the PTS and serum hemolysis index. There were statistically significant differences in several biochemistry tests. However, none of them reached the clinical significance threshold. Basophil and large unidentified cell (LUC) tests had poor correlations (r=0.47 and r=0.60; respectively) and reached clinical significance threshold (the average percentages of bias, 10.2%, and 15.4%, respectively). The remainder of the hematology and coagulation parameters did not reach clinical significance level either. CONCLUSIONS: The modern PTS validated in this study is safe for sample transportation for routine chemistry, coagulation, and hematology tests frequently requested in healthy individuals except for basophil and LUC.

Evaluation of periodontal status in different phenotypes of polycystic ovary syndrome in untreated patients of early reproductive age: A case-control study.

AIM: A few studies demonstrated an increased risk of periodontal disease in patients with polycystic ovary syndrome (PCOS). The aim of this study was to evaluate the periodontal status in women of reproductive age who were recently diagnosed with different phenotypes of PCOS. METHODS: This prospectively designed cross-sectional case-control study included 116 consecutive subjects with PCOS and 90 healthy volunteers, aged between 18 and 24, who were admitted to the gynecology polyclinic between April 2018 and December 2018. All subjects of PCOS diagnosed using the Rotterdam criteria were subdivided into four phenotypes based on clinical, biochemical and ultrasonographic parameters according to the guidelines of the National Institutes of Health. The same dentist investigated periodontal parameters including plaque index, gingival index, bleeding on probing (%), probing depth, clinical attachment loss and the decayed, missing, filled teeth index. RESULTS: Probing depth, a periodontal parameter, was higher in all sub-phenotypes of the PCOS group compared to the control group. There was no difference in other periodontal parameters. CONCLUSION: Periodontal probing depth, which is an important parameter in the diagnosis of periodontal diseases, was higher in all phenotypic subgroups of PCOS in early reproductive age.

Is otitis media with effusion associated with oxidative stress? Evaluation of thiol/disulfide homeostasis.

BACKGROUND: We evaluated the relationship between otitis media with effusion and thiol/disulfide homeostasis using a novel marker of oxidative stress. METHODS: The study group consisted of 30 patients (mean age 8.33 ±â€¯3.30 years) with bilateral otitis media with effusion admitted to our hospital. The control group consisted of 35 (mean age 7.40 ±â€¯3.97 years) age-, sex-, and body mass index-matched healthy subjects. Thiol/disulfide homeostasis was measured using a newly developed method. RESULTS: Native and total thiol levels were lower in the study than the control group (native thiols 421.37 ±â€¯72 µmol/L vs. 464.46 ±â€¯46.42 µmol/L, p < 0.05; total thiols 468.42 ±â€¯77.89 µmol/L vs. 501.32 ±â€¯50.30 µmol/L, respectively). Disulfide levels and the disulfide/native thiol and disulfide/total thiol ratios were higher in the study group (disulfides 23.56 ±â€¯4.68 µmol/L vs. 18.43 ±â€¯4.94 µmol/L; disulfide/native thiol ratio 5.65 ±â€¯1.05 vs. 3.97 ±â€¯1.03%; disulfide/total thiol ratio 5.06 ±â€¯0.83 vs. 3.66 ±â€¯0.88%, respectively). CONCLUSION: Oxidative stress may be the major cause of the increase in oxidized thiols in patients with bilateral otitis media with effusion, however, this relationship requires further investigation.

Thiol disulphide homeostasis in patients with acute myocardial infarction (AMI).

OBJECTIVE: To investigate novel oxidative stress marker thiol disulphide homeostasis in patients with acute myocardial infarction.. METHODS: The case-control study was conducted at Yildirim Beyazit University, Ankara, Turkey, between October 26, 2015 and January 26, 2016. It comprised patients of ST elevation myocardial infarction, and healthy individuals. Troponin levels, native thiol, total thiol, and disulphide were compared among the groups. Results: Of the 128 subjects, 98(76.5%) were patients and 30(23.43%) were controls. Disulphide levels were lower in the patients compared to the controls (p<0.001).As troponin levels increased, native thiol, total thiol and disulphide levels in patients decreased (p<0.05). RESULTS: Of the 128 subjects, 98(76.5%) were patients and 30(23.43%) were controls. Disulphide levels were lower in the patients compared to the controls (p<0.001).As troponin levels increased, native thiol, total thiol and disulphide levels in patients decreased (p<0.05). CONCLUSIONS: Native thiol and total thiol levels may be used as a novel oxidative stres marker in patients with acute myocardial infarction.

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

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

The effects of adding ischemic preconditioning during desflurane inhalation anesthesia or propofol total intravenous anesthesia on pneumoperitoneum-induced oxidative stress.

BACKGROUND: The aim of the study was to explore the differences in oxidative stress during anesthesia with desflurane/N2O or propofol/remifentanil in patients undergoing laparoscopic cholecystectomy and additionally to evaluate the differential effects of desflurane and propofol on ischemic preconditioning (IP). MATERIALS AND METHODS: One hundred patients were randomly allocated to four groups. For anesthesia maintenance, the inhalation group (Group I) and the inhalation plus IP group (Group IIP) received desflurane at an end-tidal concentration of 4-6 vol% in oxygen/N2O, and the TIVA group (Group T) and TIVA plus IP group (Group TIP) received infusions of propofol and remifentanil. In Groups IIP and TIP, IP was carried out by 10 min of pneumoperitoneum followed by 10 min of deflation. Preoperative and postoperative plasma total antioxidant status (TAS), total oxidant status (TOS), paraoxonase, stimulated paraoxonase, arylesterase, ceruloplasmin, and myeloperoxidase levels were analyzed; oxidative stress index (OSI) was calculated. RESULTS: When oxidative stress parameters were compared between groups, myeloperoxidase values in Group I were statistically significantly lower compared to Group TIP (p = .004 with Bonferroni's correction). There were no differences between preoperative and postoperative TAS, paraoxonase, stimulated paraoxonase, arylesterase, or ceruloplasmin levels (p > .05). In intragroup evaluations, postoperative paraoxonase and stimulated paraoxonase levels were found to be lower than preoperative values in Group TIP (p = .021 and .012, respectively). CONCLUSION: In laparoscopic cholecystectomy lasting less than 60 min, there were no differences in the measured oxidative stress parameters between maintenance of anesthesia by desflurane/N2O and propofol/remifentanil/N2O. The addition of 10 min IP administration during both anesthesia techniques did not result in additional changes in the analyzed oxidative stress.

Thiol/disulfide homeostasis in patients with idiopathic recurrent pregnancy loss assessed by a novel assay: Report of a preliminary study.

AIM: To evaluate the relationship between idiopathic recurrent pregnancy loss (RPL) and oxidative stress (OS) by means of thiol/disulfide homeostasis via a novel technique. METHODS: Thirty-nine pregnant women diagnosed with idiopathic RPL were compared with 50 healthy pregnant women without a history of abortion. Idiopathic RPL was defined as experiencing two or more consecutive miscarriages prior to 20 weeks of gestation with the presence of normal karyotypes of couple and/or abortus materials, negative maternal screening for anticardiolipin, anti ß 2 glycoprotein antibodies and lupus anticoagulant, normal thyroid stimulating hormone, prolactin and hemoglobin A1C levels and normal pelvic sonography and/or hysterosalpingography. A new and fully automated method was used to measure plasma native thiol, total thiol and disulfide levels, based on the reduction of dynamic disulfide bonds to functional thiol groups by sodium borohydrate. RESULTS: Women with idiopathic RPL had significantly lower plasma levels of native thiol (341.89 ± 50.0 µmol/L vs. 390.84 ± 38.5 µmol/L, P < 0.001) and total thiol (386.18 ± 51.7 µmol/L vs. 435.78 ± 42.3 µmol/L, P < 0.001). Disulfide/thiol and disulfide/total thiol ratios were significantly higher in the study group. The native thiol/total thiol ratio was significantly lower in patients with idiopathic RPL. No difference was measured in disulfide, albumin and total protein plasma levels. CONCLUSIONS: The main outcome of our study indicates a relation between idiopathic RPL and OS. More importantly, the new method used in our study proposes a promising, practical and daily applicable test for evaluating patients with idiopathic RPL.

Elevated Kynurenine Levels in Patients with Primary Sjögren's Syndrome.

OBJECTIVE: We aimed to investigate the plasma levels of tryptophan (Trp) and its metabolites in patients with primary Sjögren's syndrome (pSS). METHODS: The study included 34 pSS patients and 42 healthy individuals, and serum Trp and kynurenine (Kyn) concentrations were measured by liquid chromatography with tandem mass spectrometry. Trp degradation was predicted using the ratio of Kyn and Trp concentrations (Kyn/Trp). RESULTS: In our study, the mean serum Trp concentration was found to be considerably lower in the pSS group than in the control group (P = .001). The levels of Kyn (P = .019) and the Kyn/Trp ratio (P < .001) were significantly higher in the pSS group than in the control group. The Kyn/Trp ratio was negatively correlated with C-reactive protein (r = -0.369, P = .032). CONCLUSION: We found that Kyn pathway metabolism was altered in patients with pSS. This suggests that Trp metabolism may be closely linked to the disease pathogenesis of pSS.

Investigation of plasma thiol/disulfide balance in male patients with androgenetic alopecia.

BACKGROUND: Androgenetic alopecia (AGA) is the most common cause of hair loss in men. In addition to genetic and hormonal factors, oxidative stress (OS) is suggested as a factor in the etiology. AIM: In this study, we aimed to investigate the presence of OS due to thiol disulfide balance deterioration in male patients with AGA. MATERIALS AND METHODS: A total of 45 male AGA patients and 42 healthy male controls were included in the study. Native thiol, disulfide, and total thiol levels were assessed through automated spectrophotometry. The relationship between total protein, albumin, native thiol, disulfide, and total thiol levels in addition to demographic and clinical characteristics of the patients were examined. RESULTS: The mean age of the patients was 32.6 ± 10 years, and the median AGA duration in the patients was 3 years. There was no statistically significant difference in terms of native thiol, disulfide, total thiol levels, disulfide/total thiol, disulfide/native thiol, and native thiol/total thiol ratios between AGA patients and controls. Native thiol and total thiol levels negatively correlated with age and AGA duration, while disulfide levels only correlated with age.Albumin and native thiol levels were significantly lower in patients with low vitamin D levels (p = 0.040 and p = 0.021, respectively); however, total thiol and native thiol/total thiol ratio values were significantly higher. CONCLUSION: According to this study, thiol disulfide homeostasis is in balance in male patients with AGA. In patients with emotional stress and vitamin D deficiency, the balance appears to be shifted in favor of oxidative stress.

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.

The effect of low flow anesthesia with sevoflurane on oxidative status: A prospective, randomized study.

OBJECTIVES: To assess the impact of low-flow, mid-flow, and high-flow sevoflurane anesthesia on the oxidative state by measuring thiol/disulfide levels in patients undergoing surgery. METHODS: The study included 99 patients randomly assigned to 3 groups. In the low-flow anesthesia group, the fresh gas flow was diminished to 1 L.min-1 for anesthesia maintenance after 6 L.min-1 was administered for the first 10 minutes. In the mid-flow anesthesia group, fresh gas flow was applied as 2 L.min-1. In the high-flow anesthesia group, the fresh gas flow was administered as 4 L.min-1 throughout the operation. Blood samples were obtained before induction, at the 60th minute after induction, and at 2 hours postoperatively. Native thiol, total thiol, disulfide analyzed and disulfide/native thiol percentage, disulfide/total thiol percentage, and native thiol/total thiol percentage were calculated. RESULTS: Disulfide values in mid-flow and low-flow anesthesia were significantly lower at the 60th minute after induction compared to the high-flow anesthesia group. In the group evaluations, intraoperative native thiol levels in the high-flow group were found to be substantialy lower than preoperative values. CONCLUSION: It was sighted that low-flow anesthesia with sevoflurane prohibited oxidative damage. It was concluded that low flow anesthesia can be utilized safely in this respect.

Low rate of latent autoimmune diabetes in adults (LADA) in patients followed for type 2 diabetes: A single center's experience in Turkey.

OBJECTIVE: In this study, we aimed to determine the frequency of and the clinical and metabolic features of patients with latent autoimmune diabetes in adults (LADA) at a single center in Turkey. METHODS: Patients over 30 years of age diagnosed with type 2 diabetes who did not require insulin for a minimum of 6 months following diagnosis were included. Data from 324 patients (163 women; 161 men), with a mean age of 54.97 ± 7.53 years, were analyzed in the study. Levels of antibodies to glutamate decarboxylase (anti-GAD) were measured in all patients, and LADA was diagnosed in patients testing positive for anti-GAD antibodies. RESULTS: Anti-GAD positivity was identified in 5 patients (1.5%). Family history of diabetes, body mass index (BMI), age, sex distribution, insulin resistance, serum triglycerides, high-density lipoprotein, and low-density lipoprotein were similar in the LADA and type 2 diabetes patients. Median HbA1c was significantly higher (10.8% vs. 7.38%, p = 0.002) and fasting C-peptide was lower (0.75 ng/mL vs. 2.82 ng/mL, p = 0.009) in patients with LADA compared to in those with type 2 diabetes. Among the 5 patients with LADA, 4 were positive for antithyroid peroxidase antibodies. The median disease duration was relatively shorter among patients with LADA (4 years vs. 7 years, p = 0.105). CONCLUSION: We observed a LADA frequency of 1.5% among Turkish patients followed for type 2 diabetes. The presence of obesity and metabolic syndrome did not exclude LADA, and patients with LADA had worse glycemic control than patients with type 2 diabetes did.

The Predictive Value of First-trimester Thiol/Disulfide Homeostasis in Preeclampsia.

OBJECTIVE: To investigate the efficacy of first-trimester thiol/disulfide homeostasis (t/dh), a new oxidative stress marker, in predicting preeclampsia. STUDY DESIGN: Prospective cohort study. PLACE AND DURATION OF STUDY: Department of Obstetrics and Gynecology, University of Health Sciences, Zeynep Kamil Women and Children Diseases Training and Research Hospital, Istanbul, Turkey, Department of Obstetrics and Gynecology, Bursa Yüksek Ihtisas Training and Research Hospital, Bursa, Turkey, from March 2016 to February 2019. METHODOLOGY: In this multi-centre,serum samples of women with839 singleton pregnancies were collected between 11+0 to 13+6gestational weeks. A total of 215 singleton pregnant women were included in the study. The patient group consisted of 38 women, who were diagnosed with preeclampsia; while the control group consisted of 177 healthy pregnant women without any complication during pregnancy and after delivery. Totalthiol (TT) was estimated by the sum of existing thiol groups and reduced thiol groups (S-S and -SH). After the native thiols (-SH) and (TT) were determined, the disulfide (-SS) amounts, disulfide/total thiol percent ratios (-SS/-SH + -SS), disulfide/native thiol percent ratios (-SS/-SH), and native thiol/total thiol percent ratios (-SH/-SH + -SS) were calculated. RESULTS: There were no statistically significant differences between the groups in terms of[(-SH), (TT), (-SS), (-SS/-SH), (-SS/-SH + -SS), and (-SH/-SH + -SS)] six t/dh variables(p>0.05).The first-trimester body mass index (BMI) was statistically different between the two groups (p<0.001). In the receiver operating characteristic curve analysis, none of the concentrations of thiol levels and ratios was found to have a significant predictive value for preeclampsia. The BMI was a significant predictor for preeclampsia (area under curve: 0.749, p<0.001). CONCLUSION: Maternal serum t/dh at 11+0 to 13+6 weeks of gestation does not predict preeclampsia and t/dh may be the consequence rather than a cause in the pathogenesis of preeclampsia. Key Words: First-trimester, Preeclampsia, Sulfhydrylcompounds, Thiols.

Thiol/Disulphide Homeostasis, Ischemia Modified Albumin, and Ferroxidase as Oxidative Stress Markers in Women with Obesity with Insulin Resistance.

BACKGROUND: The purpose of the study was to determine oxidative stress-related plasma thiol/disulphide, ischemia-modified albumin (IMA) levels and ferroxidase activity among women with obesity in insulin-resistant and non-insulin-resistant groups in comparison with an overweight group. METHODS: We compared plasma thiol/disulphide, IMA levels, and ferroxidase activity between the study groups. We analyzed plasma thiol/disulphide homeostasis with a newly developed automated measurement method; IMA with Albumin Cobalt Binding Test and ferroxidase (ceruloplasmin) levels with an automated, colourimetric method. RESULTS: There were no significant differences between insulin-resistant and non-insulin-resistant women with obesity in terms of plasma native thiol, total thiol, disulphide, disulphide/native thiol ratio, disulphide/total thiol or native thiol/total thiol values. Ferroxidase activity was higher in insulin-resistant than in non-insulin-resistant women with obesity and higher in the total women with obesity group than in the overweight subjects (p<0.001, and p=0.014, respectively). IMA was lower in the insulin-resistant group than in the non-insulin-resistant group and overweight groups (p=0.011, and p=0.042, respectively). CONCLUSIONS: The significantly greater increase in ferroxidase activity in insulin-resistant subjects with obesity may reflect its role as a positive acute phase protein. These findings may be related to the pathogenesis of the disease. Changes in oxidative status occur in women with obesity, and partially in overweight subjects. The ferroxidase activity of ceruloplasmin plays a crucial role in iron homeostasis and lowers oxidative stress by reducing the detrimental effects of iron.

Research on the Balance of Thiol-Disulfide in Blood Serum in Women with Telogen Effluvium.

BACKGROUNDS: Telogen effluvium (TE) is the most common reason for hair loss in humans. Although the exact etiopathogenesis of TE has not been revealed clearly and completely, multifactorial etiologies are to be blamed. In recent years, since oxidative stress (OS) has been shown to play an important role in the etiopathogenesis of so many diseases, the effects of OS on several skin diseases are researched and analyzed. Thiols are antioxidant components that include sulfur group, and the balance of thiol-disulfide has an important role in the formation and prevention of OS. This balance is destroyed in many diseases and its effect on TE is not clearly understood yet. OBJECTIVES: In this study, we aimed to search the thiol-disulfide balance that could reveal OS in patients with TE. MATERIALS AND METHODS: Fifty-two patients with TE and control group of 46 persons were included in the study. Native thiol, disulfide, and total thiol levels were evaluated by a new, automatic spectrophotometric method. Disulfide/native thiol, disulfide/total thiol, and native thiol/total thiol rates were calculated. RESULTS: There was no statistical difference between TE patients and control group in terms of native thiol, disulfide, and total thiol levels. Thiol-disulfide balance was fixed and not affected in TE patients.

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.

Thiol/Disulfide Balance in Patients with Familial Hypercholesterolemia.

OBJECTIVE: Herein, we investigated the balance of thiol/disulfide, with the hypothesis that the balance between disulfides and thiols, which are natural antioxidants, might be disrupted in patients with familial hypercholesterolemia, which eventually leads to endothelial damage. METHODS: In this study, we evaluated 51 patients diagnosed with familial hypercholesterolemia and 81 healthy subjects. Blood samples were taken from the patients after a minimum of 12 hours of fasting; samples were immediately centrifuged, stored in Eppendorf tubes, and preserved at -80°C. RESULTS: This study found that thiol levels are significantly lower in patients with familial hypercholesterolemia, whereas disulfide levels are higher (independent of age, gender, and body mass index). This means that in such patients, the thiol/disulfide balance changes in favour of disulfide. CONCLUSIONS: In this study, we found that the thiol/disulfide balance in patients with familial hypercholesterolemia is disrupted in favour of disulfide.

Oxidative Status in Patients with Benign Paroxysmal Positional Vertigo.

OBJECTIVE: Benign paroxysmal positional vertigo (BPPV) is the most frequent peripheral vestibular disorder and is particularly seen among older patients suffering from vertigo. The brief vertigo attacks in and imbalance symptoms of BPPV are caused by freely floating otoconia within the semicircular canals. The aim of this prospective study was to evaluate the role of oxidative stress, using native thiol/disulfide (SH/SS) homeostasis as a novel indicator, in the etiology of BPPV. MATERIALS AND METHODS: The 62 participants in the study included 31 patients with BPPV and, as the control group, 31 healthy individuals without any cochleovestibular disorders. RESULTS: Patients with BPPV initially had significantly lower native SH levels and significantly lower SH/total thiol (TT) ratios, as well as significantly higher SS/SH and SS/TT ratios, than the healthy controls. After successful treatment of their vertigo, which was confirmed based on the results obtained from the second blood sample, patients with BPPV still had lower SH levels and SH/TT ratios and significantly higher SS/SH and SS/TT ratios than the healthy controls. CONCLUSION: Our results suggest a role of oxidative stress in the development of BPPV, through both calcium metabolism and the direct toxic effects of free oxygen radicals, including the triggering of apoptosis.