Serum paraoxonase activity, total thiols levels, and oxidative status in patients with acute brucellosis

Oxidant and antioxidant balance in children with bacteremia

BACKGROUND

There is a crucial balance between oxidant and antioxidant defense mechanisms. We aimed to evaluate the role of the balance of these systems in children with bloodstream infection.

METHODS

We analyzed prospectively oxidant and antioxidant stress parameters from serum samples of children with BSI besides demographic and clinical data of children. Serum levels of the total antioxidant status (TAS), total oxidant status (TOS), albumin, plasma thiol, disulphide, catalase (CAT), myeloperoxidase (MPO), ischemia-modified albumin (IMA) levels, ferroxidase and arylesterase (ARES) activity were evaluated in both patients and healthy controls.

RESULTS

A total of 113 children were evaluated, 50 of them had bacteremia and the remaining 63 were healthy subjects. The median TOS values were 18.5 µmol H2O2/L and 13.1 µmol H2O2/L in patient and control groups, respectively with a statistically significant difference between groups. The mean serum IMA levels were 0.8±0.1 absorbance unit (ABSU) in patients and 0.5±0.09 ABSU in control, the difference between groups was statistically significant. The native thiol, total thiol levels and the disulphide levels were significantly lower in the patient group as compared with the control group. The myeloperoxidase level was 136 U/L in patients and 107 in controls with a statistically significant difference between groups.

CONCLUSIONS

TOS, IMA, MPO, and particularly plasma thiols seem good candidates for accurate diagnosis of bacteremia in children.

Investigation of serum ischemic-modified albumin, galectin-3, paraoxonase-1, and myeloperoxidase activity levels in patients with acute brucellosis

OBJECTIVES

Infection remains current as an important discussion topic in the etiological factors of atherosclerosis. Ischemic-modified albumin (IMA), galectin-3 (gal-3), paraoxonase-1 (PON-1), and myeloperoxidase (MPO) are biomolecules that play an important role in the pathogenesis of atherosclerosis. Our aim is to investigate serum IMA, gal-3, PON-1, and MPO activity in acute brucellosis infection.

MATERIALS AND METHODS

Forty patients with acute brucellosis and 40 healthy individuals were included in the study. Serum IMA, gal-3, PON-1, and MPO activity were analyzed by the ELISA method.

RESULTS

In acute brucellosis infection, serum gal-3, IMA, and MPO activities were found to be significantly increased compared to the control group, and PON-1 activity was found to be significantly decreased compared to the control group (p < 0.001). There was a positive correlation between serum IMA, and MPO activity (r = 0.707 p = 0.000) and a negative correlation (r = -0.943, p = 0.000) between PON-1 activity. There was a positive correlation between serum gal-3 and MPO activity (r = 0.683, p = 0.000) and IMA level (r = 0.927, p = 0.000) and a negative correlation between PON-1 activity (r = -0.951, p = 0.000).Conclusion, it was found that serum gal-3, IMA levels and MPO activity increased, while PON-1 activity decreased. These results showed that the oxidant-anti-oxidant balance is impaired in acute brucellosis infection. In addition, these results indicate that brucella infection may be increase the risk of atherosclerosis. Further studies are needed to support our findings.

Value of thiol and ischemia modified albumin (IMA) in predicting mortality in serious COVID-19 pneumonia

Background/aim

Viral infections of the respiratory tract are generally related to many factors such as excessive production of cytokines, inflammation, cellular death, redox imbalance or oxidative stress. The aim of this study was to determine the serum levels of thiol and IMA in patients with severe COVID-19 pneumonia to evaluate oxidative stress.

Study design

This was a prospective, sectional cohort study conducted at a pandemics hospital between 01.01.2022 and 01.02.2022.

Methods

A total of 153 patients who had been confirmed with severe COVID-19 pneumonia in the emergency unit were prospectively analyzed. The control group was formed by 50 healthy volunteers with similar age and no chronic disease history. Thiol and IMA levels were statistically compared both in the patient and the control groups, and within the patient groups (survived and non-survival).

Results

While 96 out of 153 patients had survived, 57 patients had non-survival. There was a statistically significant distinction between the survived and non-survival patients with regard to Thiol and IMA levels (p < 0.001). The thiol levels in the patient group were significantly lower compared to the control group, and the IMA levels were significantly higher (p < 0.001). The sensitivity, specificity and NPV were 70.2%, 86.5% and 83% when thiol cut-off value was ≤345.2 μmol/L (AUC: 0.886, p < 0.001). The sensitivity, specificity and NPV were 70.2%, 85.4% and 82.8% when the IMA cut-off was >302.9 ABSU (AUC: 0.875, p < 0.001).

Conclusions

Our results demonstrate that thiol and IMA levels may be used as bioindicators for risk classification and mortality in patients with serious COVID-19 pneumonia.

Oxidant and antioxidant balance in patients with COVID-19

BACKGROUND

A crucial balance exists between oxidant and antioxidant mechanisms in the functional immune system. We aimed to evaluate the contributions of balance between these systems to coronavirus disease 2019 (COVID-19), a devastating pandemic caused by viral infection.

METHOD

We analyzed serum oxidant and antioxidant stress parameters according to the clinical and demographic characteristics of children and adults with COVID-19 and compared them against the values of healthy controls. Serum native thiol (NT), total thiol (TT), disulfide, total antioxidant status, total oxidant status, and ischemia-modified albumin levels were evaluated and compared between groups.

RESULTS

A total of 79 children and 74 adults were evaluated in the present study, including 46 children and 40 adults with COVID-19, 33 healthy children, and 34 healthy adults. TT, NT, and disulfide levels were significantly lower in the adult COVID-19 group than in all other groups (p = .001, p = .001, and p = .005, respectively). Additionally, TT and NT levels were significantly lower in both pediatric and adult COVID-19 cases with severe disease course than mild/moderate course. TT and NT levels were identified as predictors for the diagnosis of the adult COVID-19 cases and as independent predictors for disease severity in both children and adults with COVID-19.

CONCLUSION

Parameters that reveal the oxidant and antioxidant capacity, including TT and NT, appear to be good candidates for the accurate prediction of the clinical course among patients with COVID-19.

Oxidant and Antioxidant Balance in Children with Community-Acquired Pneumonia

Objective The balance between oxidant and antioxidant defense mechanisms is crucial. In this article, we aimed to evaluate the role of this balance in community-acquired pneumonia (CAP) in children.

Methods We analyzed serum oxidant and antioxidant stress parameters according to the clinical and demographic data of children with CAP and compared them with healthy controls. Serum total antioxidant status (TAS) and total oxidant status (TOS) were evaluated and compared between the groups, along with levels of ischemia-modified albumin (IMA), antioxidant enzymes, nonenzymatic antioxidant factors, and plasma thiol.

Results Of 160 children evaluated, 106 had CAP (54 outpatients and 52 inpatients), and the other 54 were healthy (control group). Total thiol and native thiol levels were significantly lower in the inpatient group compared with the outpatient group (p = 0.004 and p = 0.005, respectively). Serum IMA differed significantly among the groups (p = 0.001), with inpatients showing the highest level. A positive correlation was found between serum IMA and C-reactive protein levels in patients with pneumonia (r = 0.351; p = 0.001).

Conclusion Parameters that provide information about antioxidant capacity may be useful in the diagnosis and prognosis of pneumonia. Our results suggest that plasma thiol levels and IMA may be good candidate biomarkers to predict hospitalization for CAP in children.

Spectrophotometric assays for evaluation of Reactive Oxygen Species (ROS) in serum: general concepts and applications in dogs and humans

Reactive oxygen species (ROS) are reactive compounds derived from oxygen. In biological systems, an excessive amount of ROS can cause oxidative damage to biological macromolecules being involved in different diseases. Several assays have been developed in the last 30 years for ROS evaluation. The objective of this article will be to provide an update about the spectrophotometric methods currently used in the assessment of ROS in serum. The chemical basis of four different techniques will be reviewed, and examples of their possible applications will be provided. A particular emphasis about the practical applications of these assays in the dog will be made, but selected information about their use in humans will also be presented for comparative purposes, following a One-Health approach. The information about the spectrophotometric assays presented in this paper should be interpreted with caution once limited information about them is available yet, and further studies should be performed to clarify what they measure and their clinical application. Ideally, when applied to evaluate a sample's oxidative status, they should be incorporated in a panel of analytes where other oxidants, antioxidants, and biomarkers of inflammation were also included.

A useful and sensitive marker in the prediction of COVID-19 and disease severity: Thiol

Thiol-disulphide homeostasis (TDH) is a new parameter indicating oxidative stress that plays a role in the pathogenesis of various clinical disorders. Our study planned to investigate TDH in COVID-19 patients. Age and gender-matched healthy subjects (n = 70) and COVID-19 patients (n = 144) were included in the study. In addition to the routine laboratory parameters of the groups, their native thiol (NT), total thiol (TT) and disulphide levels were measured. Primarily, we compared COVID-19 patients to the healthy control group for inflammatory parameters, NT, TT and disulphide levels. Then, COVID-19 patients were divided into two groups according to the severity of the disease as mild to moderate and severe COVID-19, and the three groups were compared with each other. Predictive value of thiol parameters in the diagnosis of COVID-19 and in the determining its severity, and its correlation with presence and duration of symptoms were investigated. Severe COVID-19 patients had lower NT and TT levels compared with healthy controls and mild to moderate patients (P < 0.001 for both). The results of ROC analysis show that the greatest AUC was IL-6 and NT (AUC = 0.97, AUC = 0.96, respectively) between control and COVID-19 patients, while it was CRP and NT (AUC = 0.85, AUC = 0.83) between mild to moderate and severe patients. A negative correlation was found between duration of symptoms of dyspnoea, cough, fever, and sore throat and NT (r = -0.45, P = 0.017, r = -0.418, P < 0.001, r = -0.131, P = 0.084, r = -0.452, P = 0.040, respectively). NT and TT levels have a strong predictive value in the diagnosis of COVID-19 and in determining disease severity. Our results support that changing TDH parameters appears to have an important role in disease pathogenesis and it can be used in clinical management of patients.

The role of thiol-disulfide homeostasis in neonatal sepsis

BACKGROUND AND AIM

The thiol-disulfide homeostasis is essential for the body to maintain effective antioxidant defense mechanisms. We aimed to show the relationship between sepsis and thiol-disulfide homeostasis in newborns.

MATERIALS AND METHODS

In this prospective study, 66 newborns with sepsis (group 1) and 51 healthy controls (group 2) were included. In group 1, 53 newborns were diagnosed as clinical sepsis (group 1a) and 13 as definite sepsis (group 1b). The study has two time points; the day of diagnosis (step 1) and three days after the treatment (step 2). At step 1, group 1 and group 2 were compared for thiol-disulfide homeostasis as well as inflammatory markers. At step 2, the same laboratory tests were repeated only in group 1.

RESULTS

At step 1, the levels of C-reactive protein (CRP) and interleukin-6 (IL-6) were higher, while native thiol and total thiol levels were lower in group 1 compared to controls. Serum disulfide/total thiol ratio was also significantly higher in group 1. When analyzed for subgroups of group 1, demonstration of microorganism did not affect the serum thiol levels. Within group 1, at step 2, although CRP and IL-6 levels were significantly lowered compared to step 1, we did not observe significant changes in thiol-disulfide parameters.

CONCLUSIONS

The thiol-disulfide homeostasis may have a role in the pathogenesis of sepsis in newborns. The related parameters might be new markers for the diagnosis of sepsis in newborn patients. Further studies are needed to define the role of thiol-disulfide homeostasis in the course of neonatal sepsis.

Associations of lipoprotein subclasses and oxidative stress status in pulmonary and pulmonary plus extrapulmonary sarcoidosis

Background: Sarcoidosis is an inflammatory disease with pulmonary and extrapulmonary manifestations. In such pathologic conditions, increased oxidative stress and rearrangement of high-density lipoprotein (HDL) and low-density lipoprotein (LDL) may occur. Objective: This study evaluated association of oxidative stress and lipoprotein subclasses in severe forms of pulmonary and pulmonary plus extrapulmonary sarcoidosis. Methods: Lipid parameters, LDL and HDL subclass distributions, high-sensitivity C-reactive protein (hsCRP), serum amyloid A (SAA), paraoxonase 1 (PON1), malondialdehyde (MDA), total-oxidant status (TOS), sulfhydryl (SH) groups, pro-oxidant anti-oxidant balance (PAB) were determined in 77 patients (53 isolated pulmonary and 24 pulmonary plus extrapulmonary) and 139 controls. Results: Both pulmonary and extrapulmonary sarcoidosis patients had significantly higher levels of triglycerides and TOS (P<0.05) and more LDL II, LDL III, LDL IVA particles (P<0.01), but lower HDL size, SH groups (P<0.001), PON1 activity and less LDL I subclasses (P<0.05) than controls. In isolated pulmonary disease, HDL-cholesterol (P<0.01) was significantly lower whereas proportions of HDL 3a and PAB were significantly higher (P<0.05) when compared with the control group. PON1 was significantly higher in pulmonary than in combined pulmonary-extrapulmonary disease (P<0.05). In pulmonary sarcoidosis, TOS and PON1 correlated significantly with small-sized HDL particles (P<0.05). Conclusions: Both patient groups were characterized by adverse lipoprotein profile and elevated oxidative stress. In isolated pulmonary group significant associations of oxidative stress and HDL particles distribution was demonstrated. Pulmonary sarcoidosis was associated with higher PON1 activity and rearrangement of LDL particles did not depend on disease localization. (Sarcoidosis Vasc Diffuse Lung Dis 2018; 35: 198-205).

Impaired Thiol-Disulfide Balance in Acute Brucellosis

The objective of this study was to examine a novel profile: thiol-disulfide homeostasis in acute brucellosis. The study included 90 patients with acute brucellosis, and 27 healthy controls. Thiol-disulfide profile tests were analyzed by a recently developed method, and ceruloplasmin levels were determined. Native thiol levels were 256.72 ± 48.20 μmol/L in the acute brucellosis group and 461.13 ± 45.37 μmol/L in the healthy group, and total thiol levels were 298.58 ± 51.78 μmol/L in the acute brucellosis group and 504.83 ± 51.05 μmol/L in the healthy group (p < 0.001, for both). The disulfide/native thiol ratios and disulfide/total thiol ratios were significantly higher, and native thiol/total thiol ratios were significantly lower in patients with acute brucellosis than in the healthy controls (p < 0.001, for all ratios). There were either positive or negative relationships between ceruloplasmin levels and thiol-disulfide parameters. The thiol-disulfide homeostasis was impaired in acute brucellosis. The strong associations between thiol-disulfide parameters and a positive acute-phase reactant reflected the disruption of the balance between the antioxidant and oxidant systems. Since thiol groups act as anti-inflammatory mediators, the alteration in the thiol-disulfide homeostasis may be involved in brucellosis.

Assessment of gold nanoparticle effects in a marine teleost (Sparus aurata) using molecular and biochemical biomarkers

Gold nanoparticles (AuNP) are increasingly employed in a variety of applications and are likely to be increasing in the environment, posing a potential emerging environmental threat. Information on possible hazardous effects of engineered nanoparticles is urgently required to ensure human and environmental safety and promote the safe use of novel nanotechnologies. Nevertheless, there is a lack of comprehensive knowledge on AuNP effects in marine species. The present study aimed to assess AuNP effects in a marine teleost, Sparus aurata, by combining endpoints at different biological levels (molecular and biochemical). For that purpose, fish were exposed via water for 96h to 4, 80 and 1600μgL(-1) of AuNP (∼40nm) coated with citrate or polyvinylpyrrolidone (PVP). Results revealed a significant impact of AuNP-PVP in the hepatic expression of antioxidant, immune and apoptosis related genes. Total oxidative status was increased in plasma after exposure to the lowest concentration of AuNP-PVP, although without altering the total antioxidant capacity. Furthermore, AuNP did not induce significant damage in the liver since the activity of neither hepatic indicator (aspartate aminotransferase and alkaline phosphatase) increased. Overall, the present study demonstrated that AuNP, even with a biocompatible coating is able to alter oxidative status and expression of relevant target genes in marine fish. Another important finding is that effects are mainly induced by the lowest and intermediate concentrations of the PVP coated AuNP revealing the importance of different coatings.

Alteration of thiol-disulphide homeostasis in acute tonsillopharyngitis

OBJECTIVE

Thiol-disulphide homeostasis (TDH) has a critical role in various clinical disorders. We aimed to assess the association of TDH with acute tonsillopharyngitis (AT) in children.

METHODS

This study included 94 (73 viral and 21 bacterial) tonsillopharyngitis patients and 88 control children. Their native thiol, total thiol, and disulphide levels were measured.

RESULTS

Viral and bacterial tonsillopharyngitis patients had lower native thiol levels compared with healthy children (P < 0.001 and P = 0.008, respectively). Both groups had lower total thiol levels compared with control children (P = 0.002 for viral, P = 0.011 for bacterial). The disulphide levels were lower in bacterial than in viral tonsillopharyngitis patients (P = 0.04), and there was a significant difference between viral tonsillopharyngitis patients and the control group (P < 0.001). The native/total thiol ratio in each patient group was lower than in the control group (P < 0.001 for viral, P = 0.017 for bacterial). The disulphide/native thiol and disulphide/total thiol ratios were significantly higher in viral (P < 0.001 for both) and bacterial tonsillopharyngitis patients (P = 0.017 for both) than in healthy children. In all patients, a correlation was found between the levels of C-reactive protein (CRP) and native thiol (r = -0.211, P = 0.04), CRP and total thiol (r = -0.217, P = 0.036), white blood cell (WBC) and native thiol (r = -0.228, P = 0.002), WBC and total thiol (r = -0.191, P = 0.01), and WBC and disulphide (r = 0.160, P = 0.03).

DISCUSSION

TDH is altered in AT in children. The alteration is more prominent in viral than in bacterial tonsillopharyngitis.

The common variant Q192R at the paraoxonase 1 (PON1) gene and its activity are responsible for a portion of the altered antioxidant status in type 2 diabetes

In this study, we investigated the effects of paraoxonase 1 (PON1) activities and the variant PON1-Q192R on the ferric reducing ability of plasma (FRAP) and total thiol. In addition, we examined the distribution of genotypes of this variant and the relationship of the genotypes with age in patients with type 2 diabetes (T2D). A total of 115 patients with T2D were enrolled in this study. Paraoxonase activity (PON-para) and arylesterase activity (PON-aryl) were determined using spectrophotometric assays. The distribution of the Q192R genotypes was determined by the double substrate method. The antioxidant status was evaluated by determining FRAP and total thiol. The frequencies of Q and R allozyme were 0.78 and 0.22, respectively. The multivariate analysis identified a significant association between the variables PON1-Q192R (Wilks' λ = 0.85, P = 0.002) and PON-aryl (Wilks' λ = 0.896, P = 0.017), with FRAP and total thiol. The significant difference observed for PON1-Q192R and PON-aryl is primarily due to the changes in FRAP levels (η(2 )= 0.127, P = 0.002 for PON1-Q192R; η(2 )= 0.083, P = 0.011 for PON-aryl). The interaction PON1-Q192R-PON-aryl increased the effect sizes from 8 to 19% for FRAP. Only in R-carrying genotypes, there were significant correlations between both PON-para/HDL (r = -0.574, P < 0.001) and PON-aryl/HDL (r = -0.577, P < 0.001) with age. Our data suggest that the variant PON1-Q192R and PON1 activity, particularly PON-aryl, influenced the antioxidant status in T2D. The interaction of this variant and PON1 activity increased the effect size on the antioxidant capacity. Moreover, the presence of the R allozyme may potentiate the effects of age on susceptibility to cardiovascular diseases in T2D.

The Role of Oxidative Damage in the Pathogenesis and Progression of Alzheimer's Disease and Vascular Dementia

Oxidative stress (OS) has been demonstrated to be involved in the pathogenesis of the two major types of dementia: Alzheimer's disease (AD) and vascular dementia (VaD). Evidence of OS and OS-related damage in AD is largely reported in the literature. Moreover, OS is not only linked to VaD, but also to all its risk factors. Several researches have been conducted in order to investigate whether antioxidant therapy exerts a role in the prevention and treatment of AD and VaD. Another research field is that pertaining to the heat shock proteins (Hsp_s), that has provided promising findings. However, the role of OS antioxidant defence system and more generally stress responses is very complex. Hence, research on this topic should be improved in order to reach further knowledge and discover new therapeutic strategies to face a disorder with such a high burden which is dementia.