Assessment of dynamic thiol-disulfide homeostasis in patients with lipoid proteinosis (Urbach-Wiethe syndrome)

SUMMARY OBJECTIVE: Lipoid proteinosis is a rare autosomal recessive genetic dermatological disease that occurs due to the accumulation of hyaline material in the skin and mucous membranes. This study aimed to investigate whether dynamic thiol-disulfide homeostasis is a new marker of oxidative stress in patients suffering from lipoid proteinosis. METHODS: The study group involved 17 patients with lipoid proteinosis and 17 healthy controls with same gender and age. Native thiol, total thiol, disulfide levels, and thiol-disulfide indexes were measured with the fully automated spectrophotometric method described by Erel and Neselioglu, and the results of the two groups were statistically analyzed. RESULTS: Serum total thiol and native thiol levels were significantly lower in lipoid proteinosis group compared to the control group (p=0.020 and p=0.014, respectively). The disulfide levels were found to be higher in lipoid proteinosis group, but there was no significant difference between two groups. CONCLUSIONS: Impaired dynamic thiol-disulfide homeostasis was observed in lipoid proteinosis patients, suggesting that thiol-disulfide homeostasis may have a role in the pathogenesis of this disease.

An evaluation of the relationship between vitamin D level and CTRP-9, tumor necrosis factor-alpha, thiol-disulfide hemostasis in women

SUMMARY OBJECTIVE: Many chronic diseases such as malignancy, cardiovascular diseases, endothelial dysfunction, and autoimmune diseases, which have been shown to be related to vitamin D in various studies; have similar relations with CTRP-9, TNFα, and thiol-disulfide hemostasis. We aimed to contribute to the literature by evaluating the relationship between CTRP-9, TNFα, and thiol-disulfide hemostasis and vitamin D levels, which we thought may have some effects on the pathogenesis of vitamin D deficiency. METHODS: In our study, 78 female volunteers older than 18 years were included. Volunteers were divided into three groups according to the reference values of vitamin D levels. Biochemical parameters, CTRP-9, TNFα, and thiol/disulfide hemostasis tests taken from all volunteers were studied. RESULTS: In this study, there was a significant difference in CTRP-9, TNFα, total thiol (TT), native thiol (NT), DIS (disulfide), TT/DIS, and NT/DIS levels in vitamin D groups (p<0.05). There was a significant negative correlation between vitamin D and TNFα and DIS, while a significant positive correlation was found with CTRP-9, TT, NT, TT/DIS, and NT/DIS (p<0.05). CONCLUSIONS: It was determined that vitamin D deficiency causes a significant decrease in CTRP-9 level and a significant increase in TNFα level, as well as an increase in thiol/disulfide hemostasis in favor of disulfide, which may be a risk factor for increased oxidative stress. We considered that these changes may play mediator roles for many chronic diseases and metabolic disorders that are increasing in frequency due to vitamin D deficiency.

The effect of continuous ventilation on thiol-disulphide homeostasis and albumin-adjusted ischemia-modified albumin during cardiopulmonary bypass

Abstract Objective: To investigate the effect of continuous lung ventilation with low tidal volume on oxidation parameters, such as thiol/disulphide homeostasis and albumin-adjusted ischemia-modified albumin (AAIMA), during cardiopulmonary bypass (CBP) in coronary artery bypass grafting (CABG). Methods: Seventy-four patients who underwent elective CABG with CPB were included in the study. Blood samples were taken in the preoperative period, 10 minutes after CPB, and six and 24 hours postoperatively. Patients were assigned to the continuous ventilation group (Group 1, n=37) and the non-ventilated group (Group 2, n=37). The clinical characteristics, thiol/disulphide homeostasis, ischemia-modified albumin (IMA), and AAIMA levels of the patients were compared. Results: A significant difference was found between the groups regarding native thiol, total thiol, and IMA levels at the postoperative 24th hour (P=0.030, P=0.031, and P=0.004, respectively). There was no difference between the groups in terms of AAIMA. AAIMA levels returned to preoperative levels in Groups 1 and 2, at the 6th and 24th postoperative hours, respectively. Length of hospital stay was significantly shorter in Group 1 (P<0.001) than in Group 2. Conclusion: Continuous ventilation during CPB caused an increase in native and total thiol levels, an earlier return of AAIMA levels, and shorter hospital stay. Continuous ventilation may reduce the negative effects of CPB on myocardium (Table 2, Figure 1, and Reference 31).

Dynamic thiol/disulfide homeostasis in patients with age-related macular degeneration / Homeostase dinâmica de tiol/dissulfureto em pacientes com degeneração macular relacionada à idade

ABSTRACT Purpose: We evaluated dynamic thiol/disulfide homeostasis (TDH), malondialdehyde (MDA) levels, and catalase (CAT) activity in patients with age-related macular degeneration (AMD). All analyzes were conducted on plasma samples. Methods: Thirty-two patients with AMD and 38 age-matched healthy controls were included. Native thiol, total thiol, and disulfide levels and TDH status were determined using a novel, automated assay. MDA levels and CAT activity were determined. Percentages were compared using the chi-squared test. The Student's t-test and Mann-Whitney U-test were used to compare quantitative variables. Results: Native thiol levels were significantly lower (p=0.004) in patients with AMD (272.02 ± 52.41 µmol/l) than in healthy individuals (307.82 ± 47.18 µmol/l), whereas disulfide levels were significantly higher (p<0.001) in patients with AMD than in controls (21.64 ± 5.59 vs. 14.48 ± 5.37 µmol/L). Dynamic TDH was also significantly lower (p<0.001) in patients with AMD than in controls (13.41 ± 4.3 vs. 25.41 ± 14.52 µmol/l). No significant differences were evident in total thiol or MDA levels. Mean CAT activity was significantly higher (p=0.043) in patients with AMD compared with controls (0.035 vs. 0.018 k/ml). Conclusions: The antioxidant/oxidant balance demonstrated by dynamic TDH is shifted to the oxidative side in patients with AMD.

RESUMO Objetivo: Avaliar a homeostase dinâmica de tiol/dissulfureto e os níveis de malon dialdeído (MDA) e catalase (CAT) em pacientes com degeneração macular relacionada à idade (DMRI). Todas as análises foram realizadas em amostras de plasma. Métodos: Foram incluídos 32 pacientes com degeneração macular relacionada à idade e 38 controles saudáveis de idade similar. Os níveis de tiol, tiol total, dissulfureto e estado de homeostase de tiol/dissulfureto foram determinados utilizando um novo ensaio automatizado. Os níveis de atividade de MDA e CAT foram também determinados. As porcentagens foram comparadas pelo teste do qui-quadrado. O teste t de Student e o teste U de Mann Whitney foram utilizados para comparar variáveis quantitativas. Resultados: Os níveis de tiol nativo foram significativamente menores (p=0,004) nos pacientes com degeneração macular relacionada à idade (272,02 ± 52,41 µmol/l) do que nos indivíduos saudáveis (307,82 ± 47,18 µmol/l), enquan to os dissulfetos foram significativamente maiores em pacientes com degeneração macular relacionada à idade (21,64 ± 5,59 µmol/l versus 14,48 ± 5,37 µmol/l, respectivamente, p<0,001). A homeostase dinâmica de tiol/dissulfureto também foi significativamente menor nos pacientes com degeneração macular re la cionada à idade (13,41 ± 4,3 µmol/l) versus os controles (versus 25,41 ± 14,52 µmol/l, p<0,001). Não foram observadas diferenças significativas nos níveis de tiol total ou MDA. A atividade média de CAT foi significativamente mais elevada (p=0,043) em doentes com degeneração macular relacionada à idade (0,035 k/ml vs. 0,018 k/ml). Conclusões: O equilíbrio antioxidante/oxidante demonstrado pela homeostase dinâmica de tiol/dissulfeto é deslocado para o lado oxidativo em pacientes com de generação macular relacionada à idade.

Oxidation of the albumin thiol to sulfenic acid and its implications in the intravascular compartment: [review]

Human serum albumin (HSA) is the most abundant protein in the intravascular compartment. It possesses a single thiol, Cys34, which constitutes ~80 percent of the total thiols in plasma. This thiol is able to scavenge plasma oxidants. A central intermediate in this potential antioxidant activity of human serum albumin is sulfenic acid (HSA-SOH). Work from our laboratories has demonstrated the formation of a relatively stable sulfenic acid in albumin through complementary spectrophotometric and mass spectrometric approaches. Recently, we have been able to obtain quantitative data that allowed us to measure the rate constants of sulfenic acid reactions with molecules of analytical and biological interest. Kinetic considerations led us to conclude that the most likely fate for sulfenic acid formed in the plasma environment is the reaction with low molecular weight thiols to form mixed disulfides, a reversible modification that is actually observed in ~25 percent of circulating albumin. Another possible fate for sulfenic acid is further oxidation to sulfinic and sulfonic acids. These irreversible modifications are also detected in the circulation. Oxidized forms of albumin are increased in different pathophysiological conditions and sulfenic acid lies in a mechanistic junction, relating oxidizing species to final thiol oxidation products.

Study on diallyi disulfide inhibiting the proliferation of human small cell lung cancer H446 cells / 中国医师杂志

Objective To investigate the effects of diallyl disulfide (DADS) on ceil proliferation in human small cell lung cancer H446 cells in vitro. Methods MTT assay was used to observe inhibitory effect of DADS on proliferation of H446 cells. Cell Proliferation in-hibition was measured by growth curve analysis, average doubling time, vitality detection and MT]" assay. Cell morphology was observed by inversion microscope and optics microscope. Cell apoptosis was analyzed by cell morphology observed under light microscope, flow cytometry (FCM). Results MTT assay showed that DADS from 4 to 60 μg/ml significantly inhibited t446 ceils and exhibited a dose-dependent and time-dependent model. After exposure to DADS, H446 cell average doubling time retarded from 25. 40 hours to 145. 64 hours( P＜0.05).Flow cytometry analysis revealed that the cell content of C0-phase declined, however, hypodiplod peak was increased, which means cell ap-optosis were induced by DADS. Conclusion DADS could significantly inhibit the proliferation of H446 cells and induce the apoptosis of H446 cell.