Objective: The aim of this study was to evaluate the effects of oxidative stress on thiol-disulfide homeostasis caused by hypotensive anesthesia in mastoidectomy-tympanoplasty cases undergoing controlled hypotension. Methods: Fifty adult patients scheduled for mastoidectomy and tympanoplasty were included in the study. Anesthesia was induced with lidocaine, propofol, rocuronium, and remifentanil. The maintenance of anesthesia was continued with remifentanil infusion (target mean arterial pressure as 60-65 mmHg) along with 2% sevoflurane/40% O2/air mixture. Blood samples were taken 5 times at the t0 (before induction), t1 (intraoperatively after intubation), t2 (first hour) and t3 (second hour of the operation) and t4 (following recovery). Total thiol (TT) and Native Thiol (NT) levels were measured, and thus, Di-Sulphide (SS), Di-Sulphide/Native Thiol (SSNT), Di-Sulphide/Total Thiol (SSTT), and Native Thiol/ Total Thiol (NTTT) values were estimated. Results: During the operation, progressive decrease was observed in thiol levels of patients. There was a significant decrease in t3 thiol values when compared with t0 value. Thiol values were observed to have returned to baseline values after recovery from anesthesia (p>0.05). SS, SSNT and SSTT levels were found as increased in t1 blood samples, but increase in SSNT and SSTT levels was significant. Throughout the operation, values were observed to have dropped and reverted back to initial values. Conclusion: Since the measurement of thiol-disulfide blood values is able to show the instantaneous state of oxidative stress, it can be used in anesthesia practice in which every event occurs very quickly.
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Objective: Lumbar disc herniation (LDH) is a socio-economic burden. The physiopathology of the disease is not clarified completely. This study aimed to investigate the oxidation-reduction balance in LDH via serum thiol-disulfide and ischemia-modified albumin (IMA) levels. Materials and Methods: This prospective case-control study included 30 patients with LDH and a control group with 30 healthy volunteers. Blood samples were analyzed for total thiol (-SH+ -S-S-), native thiol (-SH), and IMA levels. Disulfide levels and native thiol/total thiol ratio were calculated. The results of the two groups were compared. Results: Native and total thiol levels were significantly higher in the LDH group than in the control group (p=0.007 and p=0.008, respectively). IMA levels were significantly higher in the LDH group than in the control group (p=0.000). The receiver operating characteristic curve demonstrated that the IMA value of 1.41 could predict the LDH with 80% sensitivity and 80% specificity (area under curve=0.888, confidence interval: 0.802- 0.974). Conclusion: LDH influences the thiol-disulfide balance, and increased IMA levels can predict LDH.
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Background/aim: Thiol status is a good reflector of the cellular redox and have vital roles in various cellular signaling pathways. The purpose of the study was to investigate thiol status in patients with SARS-CoV-2 infection. Materials and methods: A total of 587 subjects (517 patients/70 healthy controls) were enrolled in the study.The patients were categorized into the groups regarding to the severity of disease (mild, moderate, severe, and critical).Thiol status of all groups were compared. Results: The patients had significantly diminished thiol levels compared to controls. Thiol levels were gradually decreased as the severity of the disease increased. Logistic regression analyses identified that thiol concentrations were an independent risk factor for the disease severity in each phase (mild group OR 0.975, 95%CI 0.965-0.986; moderate group, OR 0.964, 95%CI 0.953-0.976; severe group OR 0.953, 95%CI 0.941-0.965; critical group OR 0.947, 95%CI 0.935-0.960).Thiol test exhibited the largest area under the curve at 0.949, with the highest sensitivity (98.6%) and specificity (80.4%). Conclusions: Depleted thiol status was observed in SARS-CoV-2 infection. Decline of the thiol levels by degrees while the severity of infection increased was closely related to the progression of the disease. This outcome highlights that thiols could be an impressible biomarker for predicting of the severity of COVID-19. Key words: COVID-19, inflammation, immune response, severity, thiol
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Objectives: A hypercoagulability status has been reported in SARS-CoV-2 infection. Beside their traditional roles, platelets are referred to as immune cells. The purpose of the study was to examine platelet activation and aggregation in COVID-19. Materials and Methods: This case-control study comprised 61 patients with SARS-CoV-2 infection and 18 healthy individuals. The patients were separated into groups with respect to the need for treatment in the intensive care unit (ICU). CD41, CD61, CD42a, and CD42b were determined as platelet activation markers, and platelet aggregation tests were analyzed in all groups. Results: Platelet CD41, CD61, CD42a, and CD42b expressions were significantly elevated in ICU patients compared to non-ICU patients and healthy donors. Patients in the ICU group had increased platelet aggregations than those in non-ICU patients and controls. Additionally, platelet activation and platelet function tests correlated with inflammatory and coagulation markers involving C‐reactive protein, Interleukin-6, neutrophil-to-lymphocyte ratio, platelet‐to‐lymphocyte ratio, monocyte to lymphocyte ratio, D-dimer, and fibrinogen concentrations. Conclusion: Enhanced platelet activity and faster platelet aggregation were observed in ICU COVID-19 patients. It is possible that platelet hyperreactivity may contribute to the progression of SARS-CoV-2 infection. The relationships between platelet activation and functions tests with inflammatory and coagulation markers show that systemic inflammation and cytokines may trigger the hypercoagulability in COVID-19 patients in ICU, or hyperactivated platelets could augment the inflammation.
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Objectives: Oxidative stress has a central role in metabolic disorders associated with high-carbohydrate, ani mal-based-protein diets, and excessive fat consumption. However, the molecular mechanisms of nutrition-mediated oxidative stress are complex and not fully understood. Dynamic thiol-disulfide homeostasis (DTDH) is the regulation of a balance between thiols and their oxidized forms, and includes the reversal of thiol oxidation in proteins. This study was an evaluation of DTDH and postprandial oxidative stress. Methods: A total of 86 participants (43 males and 43 females), were included in the study. Fasting and non-fasting blood samples were collected and the native thiol, total thiol, and disulfide parameters were analyzed. Statistical anal yses were performed using IBM SPSS Statistics for Windows, Version 22.0 (IBM Corp., Armonk, NY, USA). Results: The findings indicated that while the native thiol values were significantly lower in the postprandial samples, the disulfide values were significantly higher. There was no significant difference in the total thiol values. Conclusion: Examination of the DTDH revealed that the oxidative stress level increased following food intake. Protein thiols involved in antioxidant defense were oxidized and transformed into disulfides.
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Objectives: To study changes in dynamic thiol/disulfide homeostasis (TDH) in patients with acute aortic dissection (AAD).Materials and Methods: In our study, the medical records of patients who applied to Ankara Atatürk Training and Research Hospital between January 2015- January 2018 and were found to have AAD on computed tomography of the thorax were retrospectively reviewed. There were two groups in the study, one AAD group,and the other healthy volunteers' group. First, thiol and disulfide levels were determined with the spectrophotometric method defined by Erel and Neşelioğlu, natural thiol (NT), total thiol (TT), and disulfide (D) levels, and their ratios were calculated (index 1: D / NT, index 2: D / TT, index 3: NT / TT). We compared these two groups in terms of Oxidative stress parameters.Results: A total of 40 patients with AAD and 38 age-matched healthy volunteers were included in this study. There was no significant difference between the two groups in terms of gender and age (p=0.923, p=0.401, respectively). The AAD group had significantly lower natural thiol and total thiol (p<0.001), but disulfide levels were similar (p=0.360). Oxidative stress parameters were not statistically significant in terms of mortality.Conclusion: We found significantly lower thiol/disulfide homeostasis in patients with AAD, particularly native thiol and total thiol. We think that oxidative stress theory may play a role in the pathophysiology of AAD and oxidative stress parameters may guide the diagnosis.
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Objective: Thyroid hormone suppression treatment (THST) is an essential modality in treating differentiated thyroid cancer (DTC). This study aimed to evaluate thiol/disulfide homeostasis with a new method in patients on THST, which causes a state of subclinical hyperthyroidism. Material and Methods: Serum thyrotrophin (TSH), free triiodothyronine (fT3), free thyroxine (fT4), duration of disease, levothyroxine dose, and radioactive iodine (RAI) dose were evaluated along with native and total thiol and disulfide levels. Results: Data of 50 patients with DTC and 41 healthy subjects were analyzed. Though native thiol and total thiol were lower in patients with DTC, the difference was not statistically significant. Disulfide was found to be 18.25 μmol/L in DTC patients and 15.23 μmol/L in the control group. The ratios of native thiol to total thiol (N/T), disulfide to native thiol (D/N), and disulfide to total thiol (D/T) were similar in the 2 groups. Disulfide, D/N, and D/T were significantly higher, and N/T was lower in patients with overt thyrotoxicosis than patients with subclinical thyrotoxicosis and the control group. Disulfide, D/N, and D/T were both positively, and N/T was negatively correlated with fT4/fT3. Conclusion: Although the thiol/disulfide balance was maintained in patients with subclinical thyrotoxicosis, there was a shift of redox status toward disulfide in patients with overt thyrotoxicosis on THST. This suggests that the potency of oxidative stress is associated with the degree of thyrotoxicosis. Considering the potentially harmful effects of oxidative stress, overt thyrotoxicosis must be avoided in patients on THST.
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Objective: To investigate the potential role of thiol/disulphide homeostasis as a novel biomarker of oxidative stress in pa tients with diabetes and undergoing hemodialysis (HD) and its correlation with other oxidative stress markers. Materials and Methods: This study included 82 patients with end-stage renal disease undergoing HD for four hours, three times weekly for more than 24 months in the dialysis center. Of the 82 patients, 47 were non-diabetic and 35 were diabet ic. Blood samples were collected from the patients before and after the HD sessions. The thiol/disulfide pair tests were performed and total antioxidant status (TAS), total oxidant status (TOS), oxidative stress index (OSI), ischemia-modified albumin (IMA) levels, albumin levels, ceruloplasmin, catalase activity (CAT), and myeloperoxidase (MPO) activity were de termined in the serum. Results: The TAS values in all the patients, both diabetic and non-diabetic, decreased significantly after HD (p<0.001, p=0.003, and p<0.001; respectively). The TOS, albumin, native thiol (p=0.001, p=0.007, p=0.001, respectively), OSI, CAT, ceruloplasmin, IMA, MPO, and total thiol (p<0.001, p<0.001, p<0.001, p<0.001, p<0.001, and p<0.001, respectively) values increased significantly in all the patients after the HD session. The TOS, OSI, CAT, IMA, albumin, MPO, native thiol, and per centages of native/total thiol, ceruloplasmin, and total thiol values (p=0.002, p=0.002, p=0.002, p=0.001, p=0.008, p=0.001, p=0.001, p=0.003, p=0.023, and p<0.001; respectively) increased significantly in patients with diabetes after the HD session. Conclusion: In this study, we demonstrated the relationship between oxidative stress markers, which play a significant role in the pathogenesis of diabetes, and thiol/disulfide balance undergoing HD patients.
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Purpose: The aim of this study was to investigate the diagnostic value of ischemia modified albumin (IMA) in early non-ST elevation myocardial infarction (NSTEMI) patients diagnosed with high-sensitive cardiac troponin (hs-cTn)assays. Materials and Methods: In the first three hours of symptom onset, one hundred sixty-two patients without cardiovascular disease history admitted to our hospital with NSTEMI were enrolled between March 2018 and August 2019. The patients' IMA levels were compared with IMA levels of randomly selected, age and the sexmatched control group comprised of 61 subjects with normal coronary angiography results. Results: IMA levels of NSTEMI patients were higher than the control group. In receiver operating characteristic (ROC) curve analysis, a value equal or greater than 0.3855 ABSU has an 82% sensitivity and a 99.4% specificity for diagnosing NSTEMI (AUC: 0.962, 95% CI: 0.937 – 0.986,). In addition, ROC curve analysis revealed moderate predictive power for distinguishing three-vessel disease (cut-off value: 0.4290 ABSU, sensitivity 78.4% and specificity 56.3%, AUC: 0.696, 95% CI: 0.616 – 0.776,). IMA levels were positively correlated with Gensini scores of the patient group. Conclusion: Ischemia-modified albumin, when used alone, was very useful in distinguishing NSTEMI from non-ischemic controls. Besides, IMA levels were positively correlated with CAD severity.
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We planned this study to research the effect of freeze-thaw number and storage temperatures on the tests of thiol-disulfide homeostasis. Dynamic thiol-disulfide homeostasis has a crucial role in antioxidant defense reactions. Thiol disulfide homeostasis is detected in serum samples. To gauge the steadiness at different storage temperatures, sera stored at -20°C and -80°C for 1, 2, 3, 6, and 12 months. To work out the effect of the freeze-thaw cycle, sera were frozen at -80°C and subjected to ten freeze-thaw cycles at 24-hour intervals. According to our results, native thiol, total thiol, and disulfide levels in human serum samples were stable at -20°C for three months and at -80°C for 12 months. After the third month at -20°C, native thiol and total thiol levels decreased while disulfide levels increased. Additionally, as the number of freeze-thaw cycles increased, native thiol and total thiol levels decreased, and disulfide levels increased. Our results show that storage at -20°C and an increasing number of freezethaw processes affect thiols levels. To get the most accurate results, repeated freeze-thaw cycles should be avoided the maximum amount possible. Also, samples should be frozen at -80°C if long storage times are required.
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