The relationship between adjuvant chemotherapy and thiol-disulfide compounds

Aim

Thiols are the organic compounds of the antioxidant system. There is limited data in the literature concerning chemotherapy (CT) in cancer and thiol balance. In this study, we aimed to evaluate the possible changes of thiol/disulfide levels with the recurrent CT cycles and type of cancer.

Materials and Methods

The 40 healthy individuals and 40 patients who had been newly diagnosed with early-stage breast, ovary and endometrium cancer receiving adjuvant CT. Blood samples were taken from all patients three times as basal and after the first and second CT sessions.

Results

We compared preadjuvant treatment levels of thiol and disulfide parameters in the patients group with the control group. The median of native thiol and total thiol was found to be higher in the control group than in the study group (P < 0.001). In addition, disulfide/native thiol and disulfide/total thiol rates were found to be higher in the patient group (P = 0.001). When we look at the comparison before and after CT in the patient group, disulfide/native thiol and disulfide/total thiol rates, which represent increased oxidative stress (OS) levels were found to be higher after CT than before CT measurement (P < 0.016).

Discussion

This is the first study, which has researched the relationship between cancer type and thiol compounds and changes of thiol compounds during CT therapy, by using the method designed by Erel and Neşelioğlu. In this study, we found that pre-CT thiol disulfide balance in cancer patients shifted toward disulfide direction and OS levels may increase after repetitive CT sessions.

Oxidative Stress Predicts Post-Surgery Complications in Gastrointestinal Cancer Patients

INTRODUCTION

An excessive perioperative inflammatory reaction can lead to more postoperative complications in patients treated for gastrointestinal cancers. It has been suggested that this inflammatory reaction leads to oxidative stress. The most important nonenzymatic antioxidants are serum free thiols. The purpose of this study was to evaluate whether high preoperative serum free thiol levels are associated with short-term clinical outcomes.

METHODS

Blood samples were drawn before, at the end of, and 1 and 2 days after surgery of a consecutive series of patients with gastrointestinal cancer. Serum free thiols were detected using a colorimetric detection method using Ellman's reagent. Short-term clinical outcomes were defined as 30-day complications (Clavien-Dindo ≥2) and length of hospital stay. Logistic regression was applied to examine the association between serum free thiol levels and short-term patient outcomes.

RESULTS

Eighty-one patients surgically treated for gastrointestinal cancer were included in the study. Median age was 68 (range 26-87) years, and 28% were female. Patients in the lowest tertile of preoperative serum free thiols had a threefold higher risk to develop postoperative complications (odds ratio [OR]: 3.4; 95% confidence interval [CI]:1.1-10.7) and a fourfold higher risk to have an increased length of stay in the hospital (OR 4.0; 95% CI 1.3-12.9) compared with patients in the highest tertile.

CONCLUSIONS

Patients with lower preoperative serum free thiol levels, indicating a decrease in extracellular antioxidant capacity and therefore an increase in systemic oxidative stress, are more likely to develop postoperative complications and show a longer in hospital stay than patients with higher serum free thiol levels.

Effects induced by a 50 Hz electromagnetic field and doxorubicin on Walker-256 carcinosarcoma growth and hepatic redox state in rats

We compare the effects of an extremely low-frequency electromagnetic field (EMF) with the chemotherapeutic agent doxorubicin (DOX) on tumor growth and the hepatic redox state in Walker-256 carcinosarcoma-bearing rats. Animals were divided into five groups with one control (no tumor) and four tumor-bearing groups: no treatment, DOX, DOX combined with EMF and EMF. While DOX and DOX + EMF provided greater inhibition of tumor growth, treatment with EMF alone resulted in some level of antitumor effect (p < .05). Superoxide dismutase, catalase activity and glutathione content were significantly decreased in the liver of tumor-bearing animals as compared with the control group (p < .05). The decreases in antioxidant defenses accompanied histological findings of suspected liver damage. However, hepatic levels of thiobarbituric acid reactive substances, an indicator of lipid peroxidation, were three times lower in EMF and DOX + EMF groups than in no treatment and DOX (p < .05). EMF and DOX + EMF showed significantly lower activity of serum ALT than DOX alone (p < .05). These results indicate that EMF treatment can inhibit tumor growth, causing less pronounced oxidative stress damage to the liver. Therefore, EMF can be used as a therapeutic strategy to influence the hepatic redox state and combat cancer with reduced side-effects.

Serum Thiol Levels and Thiol/Disulfide Homeostasis in Patients with Rheumatic Mitral Valve Disease and Healthy Subjects

Fundamento

A doença valvar mitral reumatismal (DVMR) é a apresentação mais comum das doenças cardíacas reumáticas (DCR). Os processos de inflamação e fibrose também têm papéis significativos em sua patogênese. Estudos recentes demonstram que os tióis e o tiol-dissulfeto são marcadores de stress oxidativo inéditos e promissores.

Objetivos

O objetivo deste estudo foi avaliar diferenças entre os níveis de tiol sérico e de tiol-dissulfeto em pacientes com DVMR e no grupo de controle.

Métodos

Noventa e dois pacientes com DVMR foram cadastrados no estudo. Cinquenta e quatro sujeitos saudáveis, e com correspondência de sexo e idade em relação ao grupo de estudo, também foram incluídos no estudo como um grupo de controle. Foram investigados os níveis de tiol nos pacientes com DVMR e o grupo de controle. Os p-valores menores que 0,05 foram considerados estatisticamente significativos.

Resultados

Os pacientes com DVMR apresentaram pressão sistólica da artéria pulmonar (PSAP) e níveis de diâmetro do átrio esquerdo (AE) mais altos que os do grupo de controle. Os níveis de tiol nativo (407±83 μmol/L vs. 297±65 μmol/L, p<0,001) e tiol total (442±82 μmol/L vs. 329±65 μmol/L, p<0,001) são mais altos no grupo de controle. Níveis de dissulfeto (16,7±4,9 μmol/L vs. 14,8±3,7 μmol/L, p=0,011) são mais altos no grupo de pacientes com DVMR. Foi identificada uma correlação positiva entre as razões dissulfeto/tiol nativo e dissulfeto/tiol total com PSAP, diâmetro de AE, e gravidade da EMi. A razão dissulfeto/tiol total é significativamente mais alta em pacientes com EMi grave que em pacientes com EMi leve a moderada.

Conclusões

Até onde se sabe, este é o único estudo que avaliou a homeostase tiol/dissulfeto como um preditor inédito, que está relacionado de forma mais próxima à DVMR e à gravidade da EMi.

Thiol-disulfide homeostasis: an integrated approach with biochemical and clinical aspects

Dynamic thiol-disulfide homeostasis (TDH) is a new area has begun to attract more scrutiny. Dynamic TDH is reversal of thiol oxidation in proteins and represents the status of thiols (-SH) and disulfides (-S-S-). Organic compounds containing the sulfhydryl group is called thiol, composed of sulfur and hydrogen atoms. Disulfides are the most important class of dynamic, redox responsive covalent bonds build in between two thiol groups. For many years, thiol levels were analyzed by several methods. During last years, measurements of disulfide levels have been analyzed by a novel automated method, developed by Erel and Neselioglu. In this method, addition to thiol (termed as native thiol) levels, disulfide levels were also measured and sum of native thiol and disulfide levels were termed as total thiol. Therefore, TDH was begun to be understood in organism. In healthy humans, TDH is maintained within a certain range. Dysregulated dynamic TDH has been implicated several disorders with unknown etiology. A growing body of evidence has demonstrated that the thiol-disulfide homeostasis is involved in variety diseases, such as diabetes mellitus, hypertension, nonsmall cell lung cancer, familial Mediterranean fever (FMF), inflammatory bowel diseases, occupational diseases, gestational diabetes mellitus and preeclampsia. These results may elucidate some pathogenic mechanism or may be a predictor indicating diagnostic clue, prognostic marker or therapeutic sign. In conclusion, protection of the thiol-disulfide homeostasis is of great importance for the human being. Evidence achieved so far has proposed that thiol-disulfide homeostasis is an important issue needs to elucidate wholly.

The role of thiol levels in predicting contrast-induced nephropathy in patients with ST-segment elevation myocardial infarction who underwent primary percutaneous coronary intervention

OBJECTIVE:

Contrast-induced nephropathy (CIN) is a common complication of diagnostic or interventional procedures that may arise from administration of intravascular contrast media. Recent studies have reported the thiol-disulfide ratio as a novel oxidative stress marker. Therefore, we investigated the role of thiol levels in predicting CIN in patients with ST-segment elevation myocardial infarction (STEMI) who had undergone primary percutaneous coronary intervention (PCI).

METHODS:

A total of 302 patients were enrolled in the study. CIN was defined as an increase in serum creatinine concentration ≥0.5 mg/dL compared with the admission value or a >25% relative rise during the first 48–72 hours after the procedure. To evaluate the relationship between thiol levels and CIN, the patients were divided into a CIN group and a non-CIN group.

RESULTS:

CIN occurred in 44 (15%) patients. Native thiol (274.8±84.7 μmol/L vs. 220.8±97.1 μmol/L, p=0.001) and total thiol (305.4±89.7 μmol/L vs. 260.1±102.1 μmol/L, p=0.009) levels were higher in patients within the non-CIN group. Disulfide (15.8±6.6 μmol/L vs. 19.6±8.4 μmol/L, p=0.002) levels, and mean disulfide/total thiol ratios (8.4±3.7 vs. 5.9±3.1, p=0.001) were higher in patients with CIN (+) group. In univariate analysis, the initial native thiol, total thiol, disulfide levels, and disulfide/total thiol ratio were found to have prognostic significance in the development of CIN. In the multivariate regression analysis, only the disulfide/total thiol ratio (OR=1.190; 95% CI: 1.090–1.300; p=0.001) was significantly and independently associated with CIN. The cutoff value of the disulfide/total thiol ratio to predict CIN on admission in patients with STEMI who underwent primary PCI was 7, with a sensitivity of 68.2% and a specificity of 79.8%.

CONCLUSION:

Our results suggest that thiol/disulfide homeostasis could be a good biochemical risk marker for CIN in STEMI patients who underwent primary PCI.

Feasibility and Reproducibility of Fetal Left Ventricular Twist Using Two-Dimensional Speckle-Tracking Analysis in a Japanese Population

In fetal echocardiography, conventional parameters for assessing cardiac function are limited because of limited echocardiographic windows or the fetus' position. We aimed to evaluate the feasibility and reproducibility of fetal left ventricular (LV) twist by two-dimensional, speckle-tracking echocardiography (2DSTE) in a Japanese population.We included 55 normal fetuses at gestational ages between 21 and 36 weeks. Subjects with adverse maternal health issues were excluded. LV twist was calculated as the net difference between LV basal and apical rotation at end-systole estimated with 2DSTE.We were able to analyze the 2DSTE images in 44 cases (80%). The mean (±SE) apical rotation, basal rotation, and LV twist were 7.88 ± 0.77, -3.68 ± 0.50, and 11.1 ± 0.75 degrees, respectively. We could not analyze 11 cases (20%) because of poor image quality due to fetal position in five cases (45.5%), failure to track the endocardium because of blurred images in five cases (45.5%), and failure to obtain images of the heart due to the presence of the placenta in front of the fetus in one case (9.1%). There were no significant differences in the demographic data between pregnant women in whom LV twist analysis was feasible and not feasible. The intra- and interobserver intraclass correlation coefficients were 0.67 and 0.64, respectively.LV twist analysis by 2DSTE in the fetus was feasible in a substantial population and may provide new insight into cardiac function during the prenatal period. On the other hand, its reproducibility was moderate and needs to be improved.

Assessment of Serum Ischemia-modified albumin, Prolidase and Thiol-Disulphide Levels in Subjects With Breast Cancer

Background: Oxidative damage is of great importance for patients with breast cancer. Thus, studies were performed to identify the relationship between breast cancer and oxidative stress biomarkers.

Objectives: In this study, our aim was to find out the oxidative and antioxidant status, serum thiol-disulphide levels in subjects with breast cancer.

Methods: This study was conducted between March and June 2018 with 82 control subjects (aged between 32-67 years) and 127 breast cancer patients (aged between 27-66 years) (p=0.058) in Selcuk University Faculty of Medicine, Konya, Turkey. Serum myeloperoxidase (MPO), catalase, prolidase were analyzed with kinetic spectrophotometric and thiol-disulphide, ischemia-modified albumin (IMA), ceruloplasmin were detected by colorimetric methods.

Results: Serum levels of catalase [199.3 (16.4-489.9) vs 81.6 (18.2-322.9) (kU/L)], MPO [124±28 vs 101±31 U/L], disulphide [25 (11-61) vs 18 (2-41) µmol/L], IMA [0.66 (0.31-3.30) vs 0.62 (0.19-1.31) absorbance unit (ABSU)] and prolidase levels [2217±538 vs 1456±401 U/L] were higher in patients than control subjects (For all p<0.001 except for IMA p=0.031). Native thiol [342±60 vs 391±52 µmol/L] and total thiol levels [396±56 vs 430±52 µmol/L] were lower in patients compared with the control group (For all p<0.001).

Conclusions: Levels of serum thiol/disulphide and prolidase might be reliable indicators for determining oxidative status in certain patient populations.

The effect of tinea versicolor on thiol/disulphide homeostasis

Introduction

Tinea versicolor is a superficial fungal infection caused by Malassezia spp. Malassezia spp. is a member of the normal human skin flora. It becomes a pathogen by transforming from the yeast form to the mycelium form. The oxidant/antioxidant homeostasis may be responsible for this. Thiol/disulphide homeostasis is a new marker indicating oxidative stress. This homeostasis is affected in many illnesses.

Aim

To investigate the thiol/disulphide homeostasis in patients with tinea versicolor.

Material and methods

Forty-two patients with tinea versicolor (median age: 36 years, min.–max.: 19–58) and 36 healthy controls (median age: 32 years, min.–max.: 18–60) were included in the trial. The levels of native thiol, disulphide, and total thiol were measured by an automated method in the patient and control groups. Disulphide/total thiol, disulphide/native thiol and native thiol/total thiol rates were calculated as percentage.

Results

For the patient group and the control group, the native thiol levels were found to be 464.32 ±51.48 mmol/l and 465.18 ±51.32 mmol/l, disulphide levels – 19.80 ±7.08 mmol/l and 21.27 ±8.90 mmol/l, total thiol levels – 503.92 ±53.65 mmol/l and 508.07 ±56.59 mmol/l, respectively. No statistical difference was detected between the two groups.

Conclusions

Thiol/disulphide homeostasis was not affected in tinea versicolor. According to our findings, oxidative stress seems to have no role in the pathogenesis of tinea versicolor.