Prenatal per- and polyfluoroalkyl substances (PFAS) and maternal oxidative stress: Evidence from the LIFECODES study

BACKGROUND

Per- and polyfluoroalkyl substances (PFAS) are synthetic chemicals linked to adverse pregnancy outcomes. Although their underlying biological mechanisms are not fully understood, evidence suggests PFAS may disrupt endocrine functions and contribute to oxidative stress (OS) and inflammation.

OBJECTIVE

We examined associations between early pregnancy PFAS exposure and OS biomarkers, exploring potential effect modifications by fetal sex and maternal race.

METHODS

We used data from 469 LIFECODES participants with measured plasma PFAS (median 10 weeks gestation) and repeated measures (median 10, 18, 26, and 35 weeks gestation) of urinary OS biomarkers [8-iso-prostaglandin-F2α (8-isoprostane) and 8-hydroxydeoxyguanosine (8-OHdG)]. Protein damage biomarkers (chlorotyrosine, dityrosine, and nitrotyrosine) were additionally measured in plasma from a subset (N = 167) during the third visit. Associations between each PFAS and OS biomarkers were examined using linear mixed-effects models and multivariable linear regressions, adjusting for potential confounders, including maternal age, race, education level, pre-pregnancy BMI, insurance status, and parity. Effect modifications were evaluated by including an interaction term between each PFAS and fetal sex or maternal race in the models.

RESULTS

We observed significant positive associations between PFOS and 8-isoprostane, with a 9.68% increase in 8-isoprostane levels (95% CI: 0.10%, 20.18%) per interquartile range increase in PFOS. In contrast, PFUA was negatively associated [9.32% (95% CI: -17.68%, -0.11%)], while there were suggestive positive associations for MPAH and PFOA with 8-isoprostane. The associations of several PFAS with 8-OHdG varied by fetal sex, showing generally positive trends in women who delivered females, but negative or null in those who delivered males. No significant effect modification by maternal race was observed.

CONCLUSIONS

This study provides evidence linking PFAS exposure to OS during pregnancy, with potential sex-specific effects of certain PFAS on 8-OHdG. Further research should explore additional OS/inflammatory biomarkers and assess the modifying effects of dietary and behavioral patterns across diverse populations.

The effects of exercise and diet on oxidative stress and telomere length in breast cancer survivors

PURPOSE

Cancer and its treatments accelerate biological aging. This analysis tested the hypothesis that exercise and diet reduce oxidative stress and prevent telomere shortening in breast cancer survivors.

METHODS

In a 2 × 2 factorial design, 342 breast cancer survivors who were insufficiently physically active and had overweight or obesity at enrollment were randomized to one of four treatment groups for 52 weeks: control, exercise alone, diet alone, or exercise plus diet. The endpoints of this analysis were the change from baseline to week 52 in 8-iso-prostaglandin F2α (8-iso-PGF2α) and lymphocyte telomere length.

RESULTS

Baseline telomere length was shorter than age-adjusted normative values (median difference: - 1.8 kilobases; 95% CI - 2.4, - 1.1); equivalent to 21 years (95% CI 17, 25) of accelerated chronological aging. Compared to control, exercise alone did not change 8-iso-PGF2α [9.9%; 95% confidence interval (CI) - 1.0, 20.8] or telomere length (13.8%; 95% CI - 15.6, 43.3). Compared to control, diet alone was associated with reduced 8-iso-PGF2α (- 10.5%; 95% CI - 19.5, - 1.5) but did not change telomere length (12.1%; 95% CI - 17.2, 41.3). Compared to control, exercise plus diet was associated with reduced 8-iso-PGF2α (- 9.8%; 95% CI - 18.7, - 0.9) but did not change telomere length (- 8.5%; 95% CI - 32.1, 15.2). Change in 8-iso-PGF2α did not correlate with change in telomere length (r = 0.07; 95% CI - 0.07, 0.20).

CONCLUSION

In breast cancer survivors, diet alone or exercise plus diet were associated with reduced oxidative stress but did not change telomere length. This analysis may inform future trials that aim to optimize healthy aging in cancer survivors.

Effects of Date Palm Pollen Supplementations on The Expression of PRDX1 and PRDX6 Genes in Infertile Men: A Controlled Clinical Trial

BACKGROUND

Accumulating evidences suggest that date palm pollen (DPP) induces antioxidant activity and improves semen parameters in male rats. However, there is a few scientific evidences in support of the DPP effects on human male fertility. Hence, the effect of oral consumption of DPP on sperm parameters and expression pattern of Peroxiredoxin- 1 (PRDX1) and Peroxiredoxin-6 (PRDX6) genes was evaluated in men with infertility.

MATERIALS AND METHODS

The current controlled clinical trial included 40 men with infertility (DPP group) and 10 normospermic fertile men as controls. The DPP group received gelatinous capsules of DPP (400 mg/kg) for 74 days. Semen sampling was done before and after treatment in the both groups. Semen analysis and 8-isoprostane concentration assessments were performed by computer-assisted sperm analysis and ELISA methods, respectively. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) assays were employed to explore expression of PRDX1 and PRDX6 genes.

RESULTS

DPP consumption significantly improved semen volume (P=0.030), count (P<0.001) and morphology of sperm (P=0.023). Concentration of 8-isoprostane was significantly decreased after intervention in the DPP group (P<0.001). DPP consumption led to a significant elevation in the expression of PRDX1 and PRDX6 genes (P<0.001). Elevated gene expression of PRDX6 and PRDX1 was positively correlated with improved parameters of sperm including count, volume, motility and morphology.

CONCLUSION

Taken together, DPP seems to promote sperm quality through a decrease in reactive oxygen species (ROS) by increasing expression of antioxidant genes. Further large-scale studies are required to challenge this hypothesis (registration number: IRCT2015021221014N2).

Impact of modernization on oxidative stress among indigenous populations in northern Laos

OBJECTIVES

To explore the impact of modernization on oxidative stress during a momentous health transition process, we investigated differences in oxidative stress among the indigenous populations of villages in northern Laos with different levels of modernization.

METHODS

We conducted a cross-sectional study of 380 adults in three villages with different levels of modernization. Three biomarkers related to oxidative stress were measured: urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) and 8-isoprostane concentrations (both measured by liquid chromatography-tandem mass spectrometry), and blood telomere length (measured with qPCR). We examined associations between village-level modernization and oxidative stress-related biomarkers in a multilevel analysis including a random effect and covariates.

RESULTS

The geometric means of urinary 8-OHdG and 8-isoprostane concentrations were 2.92 and 0.700 μg/g creatinine, respectively, in our study population. Higher urinary 8-OHdG concentrations and shorter telomeres were observed in participants from the more modernized villages, whereas urinary 8-isoprostane concentrations did not differ significantly among villages.

CONCLUSIONS

Our findings imply that modernization-induced changes in lifestyle may increase oxidative DNA damage. Baseline levels of oxidative lipid damage are expected to be high in the indigenous populations of northern Laos. Assessments of oxidative stress may provide valuable insights into the mechanisms of health transition in specific populations.

Maternal Diet Quality and the Health Status of Newborns

The maternal diet during pregnancy affects neonatal health status. The objective of this study was to assess the nutritional quality of the maternal diet, and its contamination by persistent organic pollutants (POPs), in pregnant women living in two areas of the Czech Republic with different levels of air pollution, and subsequently to assess the relationship of these two factors with birth weight and neonatal oxidative stress. To determine the level of oxidative stress, 8-isoprostane concentrations in umbilical cord plasma were measured. The overall nutritional quality of the maternal diet was not optimal. Of the nutritional factors, protein intake proved to be the most significant showing a positive relationship with birth weight, and a negative relationship with the oxidative stress of newborns. Dietary contamination by persistent organic pollutants was low and showed no statistically significant relationship with birth weight. Only one of the 67 analyzed POPs, namely the insecticide dichlorodiphenyltrichloroethane (DDT), showed a statistically significant positive relationship with the level of neonatal oxidative stress.

Effects of Oxidative Damage during Ruesi Dadton Exercise in Mild Cognitive Impairment: Randomized Controlled Trial

This study aimed to investigate the effect of biomarkers of oxidative stress (OS) in 8-isoprostane (8-iso) and 8-hydroxy-2'-deoxyguanosine (8-OH-dG) on mild cognitive impairment (MCI) during a 12-week Ruesi Dadton (RD) exercise. A total of 274 enrolled participants were classified into blocks based on age and formal educational years, and randomly assigned into two groups: RD and control (CON). The participants' cognitive functions were tested using Mini-Mental State Examination and Montreal Cognitive Assessment (MoCA) scores to screen for MCI. Urine samples of approximately 30 mL were collected from both groups pre- and post-intervention. All participants signed consent forms before participating in the program. Participants in the RD group were instructed to perform 15 postures of RD exercise in 60 min, three times a week for 12 weeks. A 2 × 2 (group × time) repeated multivariate analysis, with MoCA score, 8-iso, and 8-OH-dG as covariates, was performed to analyze the between-subject differences across group [V = 0.143, F(2,60) = 5.020, p = 0.010, d = 0.209] and within-subject differences across interaction between group [V = 0.143, F(2,60) = 5.020, p = 0.010, d = 0.408]. There were significant differences from univariate data regarding both 8-iso (F1,61 = 10.081, P = 0.002, d = 0.406) and 8-OH-dG (F(1,61) = 5.965, P = 0.018, d = 0.312) levels. Moreover, results from both biomarkers in the RD group revealed significant improvements in 8-iso (p < 0.001) and 8-OH-dG (p = 0.003), whereas there were no improvements in the CON group. In conclusion, RD decreased biomarkers of OS during 12 weeks of RD exercise in MCI. These results indicate that in MCI, RD could improve lipid peroxidation and DNA oxidation by 8-iso and 8-OH-dG, respectively.

Unmasking the Confounder: The Inherent Physiologic Variability of Swine During an Automated Experimental Model of Ischemia-Reperfusion Injury

BACKGROUND

We sought to determine the magnitude of the inherent inter-animal physiologic variability by automating a porcine Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) protocol to minimize external influences that might alter physiology and confound experimental results.

METHODS

Swine (n = 42) underwent a controlled 30% blood volume hemorrhage followed by 30 minutes of REBOA (ie, ischemic phase). The animals were weaned from REBOA autonomously over 15 minutes, beginning the reperfusion phase, while continuing to provide partial flow balloon support to maintain a target proximal mean arterial pressure (pMAP) of 65 mmHg. Simultaneously, shed blood was re-transfused as part of the resuscitation efforts. Physiologic data were continuously recorded, and serum samples were serially collected. Baseline characteristics, variance in vital signs, and 8-isoprostane levels were quantified during hemorrhage, REBOA, and reperfusion phases.

RESULTS

There was no significant difference in baseline physiology across animals (P > .05). Hemodynamic variability was highest for pMAP during the ischemic phase (P = .001) and for distal mean arterial pressure (dMAP) during the weaning/reperfusion phase (P = .001). The latter finding indicated the variable physiologic response to ischemia-reperfusion injury, as the automated balloon support required by each animal to maintain pMAP was highly variable. Circulating 8-isoprostane variance was significantly higher following the start of reperfusion compared to baseline levels (P = .001).

DISCUSSION

Despite subjecting animals to a highly consistent ischemia-reperfusion injury through automation, we noted significant variability in the hemodynamic and biochemical response. These findings illustrate the inherent physiologic variability and potential limitations of porcine large animal models for the study of shock.

Effect of metformin on reducing platelet dysfunction in gestational diabetes mellitus: a randomized controlled trial

OBJECTIVES

To evaluate the effect of metformin in improving platelet dysfunction in women with gestational diabetes mellitus (GDM).

PATIENTS AND METHODS

A randomized controlled trial was conducted on pregnant women diagnosed with GDM. Singleton low-risk pregnancies meeting the inclusion criteria were randomly allocated at 27-31 weeks to receive metformin and placebo through the rest of pregnancy. Thirty-seven and 39 cases were recruited into the metformin group and the placebo group, respectively. MPVs, P-selectin, and 8-isoprostane levels were determined at the time of allocation and 6 weeks after treatment. Obstetric and neonatal outcomes were also assessed.

RESULTS

Most baseline characteristics of the two groups were comparable. The levels of P-selectin after 6 weeks of treatment were significantly higher in the metformin group (68.9 ± 14.4 vs 60.6 ± 11.3; P-value = 0.006), indicating more platelet activation. All of the obstetric and neonatal outcomes were comparable except that birth weight was significantly lower in the metformin group (3018 ± 364 g vs 3204 ± 393 g; P-value = 0.037).

CONCLUSION

Metformin, in addition to diet and lifestyle modifications, does not improve or worsen oxidative stress and platelet dysfunction in women with GDM. Nevertheless, metformin significantly reduces fetal weight in women with GDM, theoretically preventing macrosomia.

Isoprostane-8 and GDF-15 as novel markers of post-PE syndrome: Relation with prothrombotic factors

BACKGROUND

Post-pulmonary embolism (PE) syndrome occurs in up to 50% of PE patients. The pathophysiology of this syndrome is obscure.

OBJECTIVE

We investigated whether enhanced oxidative stress and prothrombotic state may be involved in post-PE syndrome.

METHODS

We studied 101 normotensive noncancer PE patients (aged 56.5 ± 13.9 years) on admission, after 5-7 days and after a 3-month anticoagulation, mostly with rivaroxaban. A marker of oxidative stress, 8-isoprostane, endogenous thrombin potential, fibrinolysis proteins, clot lysis time (CLT) and fibrin clot permeability (K_s ), along with PE biomarkers, were determined.

RESULTS

Patients who developed the post-PE syndrome (n = 31, 30.7%) had at baseline 77.6% higher N-terminal brain natriuretic propeptide and 46.8% higher growth differentiation factor 15, along with 14.1% longer CLT associated with 34.4% higher plasminogen activator inhibitor-1 as compared to subjects without post-PE syndrome (all P < .05). After 5-7 days, only hypofibrinolysis was noted in post-PE syndrome patients. When measured at 3 months, prolonged CLT and reduced K_s were observed in post-PE syndrome patients, accompanied by 23.8% higher growth differentiation factor 15 and 35.8% higher plasminogen activator inhibitor-1 (all P < .05). 8-isoprostane levels ≥108 pg/ml (odds ratio=4.36; 95% confidence interval 1.63-12.27) and growth differentiation factor 15 ≥ 1529 pg/ml (odds ratio=3.89; 95% confidence interval 1.29-12.16) measured at 3 months were associated with higher risk of developing post-PE syndrome.

CONCLUSIONS

Enhanced oxidative stress and prothrombotic fibrin clot properties could be involved in the pathogenesis of the post-PE syndrome. Elevated growth differentiation factor 15 assessed at 3 months might be a new biomarker of this syndrome.

A Novel UHPLC-MS/MS Method for Measuring 8-iso-Prostaglandin F2α in Bronchoalveolar Lavage Fluid

In August 2019, the Centers for Disease Control and Prevention (CDC) received the first reports of lung injuries that were eventually termed e-cigarette, or vaping, product use–associated lung injury (EVALI). As part of the investigation, CDC laboratories rapidly developed assays for analyzing substances in bronchoalveolar lavage (BAL) fluid collected from EVALI case patients. This report describes the development and validation of a high-throughput isotope dilution UHPLC-MS/MS method for measuring a major oxidative stress biomarker, 8-iso-prostaglandin F_2α (8-isoprostane), in BAL fluid samples. The method showed good sensitivity, 17.6 pg/ml LOD, and requires only 50 μl of sample volume. The method had high throughput with an analytical run time of 11 min. The within-day and between-day coefficient of variation (CV) were below 2%. Accuracy, calculated from spiked recovery, at three spiking levels, ranged from 95.5–101.8%. This novel UHPLC-MS/MS method characterizes oxidative stress in lung epithelial tissue and thus helps to elucidate potential pathologic processes.

Inhaled corticosteroids' effects on biomarkers in exhaled breath condensate and blood in patients newly diagnosed with asthma who smoke

OBJECTIVE

Exposure to cigarette smoke complicates the treatment and management of asthma through a variety of inflammatory effects. This study aimed to investigate the differences between newly diagnosed cases of asthma in smokers and nonsmokers in terms of localized and systemic biomarkers following treatment with inhaled corticosteroids (ICS) or ICS in combination with a long-acting β2 agonist (LABA).

METHODS

Specimens of exhaled breath condensate (EBC) from newly diagnosed patients with asthma were used to quantify inflammation in the airways, while blood samples were used to assess systemic inflammation. In both samples, the levels of IL-6, LTB4, LTD4, and 8-isoprostane were measured and these were repeated after 3 months of treatment with ICS or ICS + LABA.

RESULTS

Of the 20 patients, 10 (50%) were nonsmokers with asthma (NSA) and 10 (50%) smokers with asthma (SA). There was no statistically significant difference in the blood or EBC levels of IL-6, LTB4, LTD4, or 8-isoprostane between the groups prior to treatment. Only the decrease in 8-isoprostane level in the EBC samples was found to be significantly greater in the NSA group after treatment (for smokers, the change was 2.91 ± 23.22, while for nonsmokers it was -22.72 ± 33.12, p = 0.022). Post-treatment asthma control was significantly better in the NSA group (p = 0.033).

CONCLUSION

Monitoring the alterations in 8-isoprostane levels in EBC in patients with asthma who smoke may be helpful in deciding on therapeutic management and switching treatments. Asthma control was better in nonsmokers than in smokers.

Oxidative Stress Markers and Antioxidant Enzymes in Children and Adolescents with Depressive Disorder and Impact of Omega-3 Fatty Acids in Randomised Clinical Trial

Oxidative stress (OS) is thought to play a role in mental disorders. However, it is not clear whether the OS is the cause or consequence of the disorder. We investigated markers of oxidative stress (8-isoprostane (8-IsoP-U), lipoperoxides (LP), advanced oxidation protein products (AOPP) and nitrotyrosine (NT)) and antioxidant protection (Trolox equivalent antioxidant capacity (TEAC), activities of superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) in 60 paediatric and adolescent patients with depressive disorder (DD) compared to healthy controls. The patients were divided into two groups (1:1). One group received an emulsion of omega-3 fatty acid (FA), and the other group an emulsion of sunflower oil with omega-6 FA for 12 weeks. The levels of 8-IsoP-U, AOPP and NT were increased, and GPx activity was decreased in patients compared to the controls. We found a significant positive correlation of the Children’s Depression Inventory score with NT and a negative correlation with TEAC, SOD and GPx. NT correlated positively with the baseline omega-6/omega-3 FA ratio and a negatively with SOD. A supplementation with omega-3 FA, but not with omega-6 FA, decreased 8-IsoP-U, AOPP, NT levels and increased TEAC and SOD activity. Our results suggest that NT may play a role in the pathophysiology of DD, while elevated isoprostane is likely caused by the high omega-6/omega-3 FA ratio. Omega-3 FA supplementation reduces oxidative stress in patients with DD. This study was registered with the ISRCTN registry (ISRCTN81655012).

Oxidative biomarkers of exhaled breath condensate in adults exposed to traffic-related air pollution: a case-control study

Traffic-related air pollution exposure (TRAP) is a major public health problem. The effects of TRAP exposure on the oxidative biomarkers of exhaled breath condensate (EBC) of adults are seldom studied. We compared the oxidative EBC biomarkers in a group of individuals exposed to TRAP with those of individuals unexposed to TRAP. We conducted a case-control study in Bhopal City (Madhya Pradesh, India). Adults with a history of exposure to TRAP were enrolled as cases and adults with less exposure to TRAP were used as a control. Based on respiratory symptoms and smoking habits, study subjects were stratified into six subgroups. EBC was collected by TURBO14 (Medivac SRL, Italy) at -5 °C. The EBC pH was measured after gas standardization with argon. EBC hydrogen peroxide (H₂O₂), cystenine leukotrienes (Cys-LTs), 8-isoprostane were measured by commercial ELISA kit. A total of 250 consecutive adult (male: 194) subjects were recruited. Among them, 133 were TRAP-exposed (male: 128) and 117 were non-TRAP-exposed (male: 66). The respiratory symptoms between TRAP-exposed and non-TRAP-exposed subjects were not different. The post-gas standardized EBC pH (median: 7.72; interquartile range (IQR): 7.15-7.94 vs. median: 7.60, IQR: 6.72-7.87;p= 0.09) and EBC H₂O₂(median: 2.20µmol l^-1; IQR: 1.46-3.51 vs. median: 1.99, IQR: 1.41-3.10;p= 0.29) in TRAP-exposed subjects were statistically not different from the non-TRAP-exposed subjects. The EBC Cys-LTs (median: 69.81; IQR: 57.0-83.38 vs. median: 47.21 pg ml^-1; IQR: 39.90-54.87,p< 0.001) and EBC 8-isoprostane (median: 12.55 pg ml^-1; IQR: 5.51-18.09 vs. median: 7.12; IQR: 4.60-16.04,p= 0.026) in TRAP-exposed subjects were higher compared to those in non-TRAP-exposed subjects. The subgroup analysis showed that TRAP-exposed subjects, irrespective of their smoking habits and respiratory symptoms, had higher EBC Cys-LTs compared to the non-TRAP-exposed subjects. TRAP exposure increases oxidative biomarkers of the EBC in adults.

Use of a Highly Antioxidant Diet in the Regulation of Adipose Tissue Secretion in Patients after the BIB Procedure

Obesity is a global problem. The secretory activity of adipose tissue causes inflammation and disturbs metabolic parameters. Low-invasive bariatric procedures are an alternative to surgical treatment, especially in individuals who do not qualify for surgery or in whom conservative treatment does not bring the expected results. The diets designed for bariatric patients contained an increased proportion of bioflavonoids. The dietary components were carefully selected to provide anti-inflammatory effects. The experimental diets showed an antioxidant capacity (TEAC) of 433–969 µM TE/100 g or 100 mL, reducing ability (FRAP) of 13–58 µM TE/100 g or 100 mL, and total polyphenol content of 80–250 mg catechins/100 g or 100 mL. Lower levels of adipocytokines were obtained in the blood of patients following the diet. The results of the present study showed the participation of some adipocytokines in the regulation of energy homeostasis, lipid metabolism, glucose level, blood pressure and inflammation. Diet therapy should yield positive results in the long term, with the possibility of using immune modulation in personalized therapy for metabolic syndrome.

Isoprostane-8 in the exhaled breath condensate: Could it represent a noninvasive strategic tool for primary ciliary dyskinesia diagnosis and management?

Background and Objectives:

Exhaled breath condensate (EBC) represents a potential diagnostic tool for Primary Ciliary Diskinesia (PCD). An increased oxidative stress is present in the airways of children affected and many neutrophil chemoattractants and markers of oxidative stress can be involved. The aim of the study is to evaluate leukotriene B4 (LTB-4), interleukin 8 (IL-8), 8-isoprostane (8-IP) concentration in PCD subjects, investigating their potential role as non-invasive markers of inflammation for the diagnosis and management of PCD.

Methods:

Cross-sectional study. 43 patients were enrolled in the study and divided in two groups: PCD (27) and healthy subjects (16). Physical examination, lung function test, nFeNO measurement and EBC collection were performed in all subjects.

Results:

PCD subjects showed an EBC 8-IP concentration significantly higher than the control group (median value: 11.9 pg/ml; IQR, 5.5–24.0 vs. median, 6.7 pg/ml; IQR, 2.5–11.3, p-value of Wilcoxon rank-sum test 0.0436). LTB4 EBC concentration did not differ between the two group (median, 4.3 pg/ml; IQR, 3.0–8.8 vs. 7.5 pg/ml; IQR, 3.0–9.5; P=0.4901). No significant correlation was found between FEV1 and EBC 8-IP (r=-0.10, P=0.6314) or LTB4 concentration (r=0.03, P=0.8888) in PCD subjects. No significant correlation was found between nFeNO and EBC 8-IP (r=-0.31, P=0.1385) or LTB4 (r=0.04, P=0.8565) in PCD subjects.

Conclusions:

EBC 8-IP levels are significantly increased in PCD subjects, highlighting the role of oxidative stress in airway inflammation. It could have a potential role as a non-invasive marker of inflammation for the diagnosis and management of PCD, although a therapeutic application of this evidence seems far.

Rapid Liquid Chromatography-Tandem Mass Spectrometry Analysis of Two Urinary Oxidative Stress Biomarkers: 8-oxodG and 8-isoprostane

Human biomonitoring of oxidative stress relies on urinary effect biomarkers such as 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), and 8-iso-prostaglandin F2α (8-isoprostane); however, their levels reported for similar populations are inconsistent in the scientific literature. One of the reasons is the multitude of analytical methods with varying degrees of selectivity used to quantify these biomarkers. Single-analyte methods are often used, requiring multiple injections that increase both time and cost. We developed a rapid ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method to quantify both urinary biomarkers simultaneously. A reversed-phase column using a gradient consisting of 0.1% acetic acid in water and 0.1% acetic acid in methanol/acetonitrile (70:30) was used for separation. The MS detection was by positive (8-oxodG) and negative (8-isoprostane) ion-mode by multiple reaction monitoring. Very low limit of detection (<20 pg/mL), excellent linearity (R2 > 0.999), accuracy (near 100%), and precision (CV < 10%) both for intra-day and inter-day experiments were achieved, as well as high recovery rates (>91%). Matrix effects were observed but were compensated by using internal standards. Our newly developed method is applicable for biomonitoring studies as well as large epidemiological studies investigating the effect of oxidative damage, as it requires only minimal clean up using solid phase extraction.

The Role of Alcohol Metabolism in the Pathology of Alcohol Hangover

The limited number of available studies that examined the pathology of alcohol hangover focused on biomarkers of alcohol metabolism, oxidative stress and the inflammatory response to alcohol as potentially important determinants of hangover severity. The available literature on alcohol metabolism and oxidative stress is reviewed in this article. The current body of evidence suggests a direct relationship between blood ethanol concentration and hangover severity, whereas this association is not significant for acetaldehyde. The rate of alcohol metabolism seems to be an important determinant of hangover severity. That is, fast elimination of ethanol is associated with experiencing less severe hangovers. An explanation for this observation may be the fact that ethanol-in contrast to acetaldehyde-is capable of crossing the blood-brain barrier. With slower ethanol metabolism, more ethanol is able to reach the brain and elicit hangover symptoms. Hangover severity was also significantly associated with biomarkers of oxidative stress. More oxidative stress in the first hours after alcohol consumption was associated with less severe next-day hangovers (i.e., a significant negative correlation was found between hangover severity and malondialdehyde). On the contrary, more oxidative stress at a later stage after alcohol consumption was associated with having more severe next-day hangovers (i.e., a significant positive correlation was found between hangover severity and 8-isoprostane). In conclusion, assessment of biomarkers of alcohol metabolism suggests that fast elimination of ethanol is associated with experiencing less severe hangovers. More research is needed to further examine the complex interrelationship between alcohol metabolism, the role of acetaldehyde and oxidative stress and antioxidants, and the pathology of the alcohol hangover.

The Inflammatory Response to Alcohol Consumption and Its Role in the Pathology of Alcohol Hangover

An increasing number of studies are focusing on the inflammatory response to alcohol as a potentially important determinant of hangover severity. In this article, data from two studies were re-evaluated to investigate the relationship between hangover severity and relevant biomarkers of alcohol metabolism, oxidative stress and the inflammatory response to alcohol. Hangover severity was significantly and positively correlated with blood concentrations of biomarkers of the inflammatory response to alcohol, in particular, Interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α) and C-reactive protein (CRP). At 4 h after alcohol consumption, blood ethanol concentration (but not acetaldehyde) was significantly and positively associated with elevated levels of IL-6, suggesting a direct inflammatory effect of ethanol. In addition, biomarkers of oxidative stress, i.e., malondialdehyde and 8-isoprostrane, were significantly correlated with hangover severity, suggesting that oxidative stress also contributes to the inflammatory response. The timing of the assessments suggests initial slow elimination of ethanol in the first hours after alcohol consumption. As a consequence, more ethanol is present in the second half of the night and the next morning, which will elicit more oxidative stress and a more profound inflammatory response. Together, these processes result in more severe hangovers.

Reference Ranges of 8-Isoprostane Concentrations in Exhaled Breath Condensate (EBC): A Systematic Review and Meta-Analysis

Isoprostanes are physiopathologic mediators of oxidative stress, resulting in lipid peroxidation. 8-isoprostane seems particularly useful for measuring oxidative stress damage. However, no reference range values are available for 8-isoprosante in exhaled breath condensate (EBC) of healthy adults, enabling its meaningful interpretation as a biomarker. We conducted this systematic review and meta-analysis according to the protocol following PROSPERO (CRD42020146623). After searching and analyzing the literature, we included 86 studies. After their qualitative synthesis and risk of bias assessment, 52 studies were included in meta-analysis. The latter focused on studies using immunological analytical methods and investigated how the concentrations of 8-isoprostane differ based on gender. We found that gender had no significant effect in 8-isoprostane concentration. Among other studied factors, such as individual characteristics and factors related to EBC collection, only the device used for EBC collection significantly affected measured 8-isoprostane concentrations. However, adjustment for the factors related to EBC collection, yielded uncertainty whether this effect is due to the device itself or to the other factors. Given this uncertainty, we estimated the reference range values of 8-isoprostane stratified by gender and EBC collection device. A better standardization of EBC collection seems necessary; as well more studies using chemical analytical methods to extend this investigation.

Assessment of ventilator-associated pneumonia by combining 8-isoprostane and nitric oxide levels in exhaled breath condensate with the clinical pulmonary infection score

Objective

To investigate the effectiveness of combining the 8-isoprostane and nitric oxide (NO) levels in exhaled breath condensate (EBC) with the clinical pulmonary infection score (CPIS) to assess ventilator-associated pneumonia (VAP) in patients on mechanical ventilation.

Methods

Thirty-two patients with VAP served as the observation group and 32 patients without VAP served as the control group. The correlations of 8-isoprostane and NO levels in EBC with CPIS, chest X-ray score, oxygenation index, and lung injury score (LIS) were analyzed. The area under the curve (AUC) was compared with experimental data using the receiver operating characteristic curve (ROC) to predict VAP.

Results

The 8-isoprostane and NO levels in EBC of VAP patients on mechanical ventilation were positively correlated with CPIS, chest X-ray score, and LIS, but negatively correlated with oxygenation index. The AUC of simplified CPIS combined with 8-isoprostane and NO levels in EBC for predicting VAP was 0.914, which suggests that this is a highly effective for making a diagnosis.

Conclusions

The simplified CPIS combined with the 8-isoprostane and NO levels in EBC of patients on mechanical ventilation is effective for evaluating and diagnosing VAP. 8-Isoprostane and NO levels in EBC could be used as biomarkers to evaluate VAP.

Urinary 8-isoprostane as a biomarker for oxidative stress. A systematic review and meta-analysis

Oxidative stress is defined as an imbalance between the production and elimination of reactive oxygen species (ROS) are associated with various inflammation-related human disease. ROS can oxidize lipids, which subsequently undergo fragmentation to produce F2-isoprostanes (F2-IsoPs). Eight-isoprostane is one of the most extensively studied F2-IsoPs and the most commonly used biomarker for the assessment of oxidative stress in human studies. This urinary biomarker is quantified using either chemical or immunological techniques. A "physiological" range for 8-isoprostanes is needed to use this biomarker as a measure of excess oxidative stress originating from occupational exposures. However, ranges reported in the literature are inconsistent. We designed a standardized protocol of a systematic review and meta-analysis to assess baseline values for 8-isoprostane concentrations in urine of healthy adults and identify determinants of their inter- and intra-individual variability. We searched PubMed from journal inception and up to April 2019, and screened articles for studies containing F2-IsoPs concentrations in urine for healthy adult participants. We grouped studies in three biomarker groups: "8-isoprostane", "Isoprostanes" "15- F2t-Isoprostane". We computed geometric mean (GM) and geometric standard deviation (GSD) as the basis for the meta-analysis. Of the initial 1849 articles retrieved, 63 studies were included and 107 subgroups within these study populations were identified. We stratified the subgroups analyzed with the chemical methods by body mass index (BMI) reported. We provide pooled GM values for urinary 8-isoprostane concentrations in healthy adults, separately for chemical and immunological analysis in this review. The interquartile range (IQR) in subgroups with a mean BMI below 25 measured using chemical methods was 0.18 to 0.40 μg/g creatinine. We show that there is a significant positive association between BMI and urinary 8-isoprostane concentrations. We recommend adjusting urinary 8-isoprostane concentrations in spot urine with creatinine, quantifying 8-isoprostane with chemical analytical methods, and reporting results as median and quartiles. This will help in comparing results across studies.

An exploratory analysis of urinary organophosphate ester metabolites and oxidative stress among pregnant women in Puerto Rico

BACKGROUND

Organophosphate esters (OPEs) are used as flame retardants and plasticizers. Oxidative stress, the imbalance of reactive oxygen species and antioxidants, measured prenatally has been associated with adverse birth outcomes including preeclampsia and preterm birth. We are the first study to investigate the relationship between OPEs and oxidative stress among pregnant women.

METHODS

Pregnant women 18-40 yrs. were recruited in Northern Puerto Rico (n = 47) between 2011 and 2015. OPE concentrations of: bis(2-chloroethyl) phosphate (BCEtP), bis(1-chloro-2-propyl) phosphate (BCPP), bis(1,3-dichloro-2-propyl) phosphate (BDCPP), dibutyl phosphate (DNBP), and diphenyl phosphate (DPHP) and biomarkers for oxidative stress, 8-hydroxy-2'-deoxyguanosine (8-OHdG) and 8-isoprostane were measured in urine up to three times during pregnancy. Associations between oxidative stress biomarkers and OPEs were assessed using linear mixed models adjusted for specific gravity, age, BMI, and income.

RESULTS

Metabolites BCEtP, BDCPP, and DPHP were frequently detected (>97%). OPE metabolite concentrations remained stable over time (Intraclass correlation coefficients (ICCs): 0.51-0.60). Metabolites BCEtP, BCPP, and DPHP were associated with an increase in 8-isoprostane and OHdG. An interquartile range (IQR) increase in BDCPP was associated with a 21% increase in 8-isoprostane (p < 0.01), while and IQR increase in DPHP and BCPP was associated with a 12% increase (p = 0.04, p = 0.08, respectively). IQR increases in BDCPP and DPHP were also associated with an 18 and 19% increase in OHdG, respectively (p < 0.01).

CONCLUSION

OPE metabolites were frequently detected and our results suggest that exposure to OPEs is associated with higher levels of oxidative stress. Further investigation into these relationships and birth outcomes is warranted.

Maternal serum nitrotyrosine, 8-isoprostane and total antioxidant capacity levels in pre-gestational or gestational diabetes mellitus

OBJECTIVE

To evaluate serum concentration of 8-isoprostane, nitrotyrosine (NT), and total antioxidant capacity (TAC) in pregnant women with diabetes mellitus (DM) considering preconception planning and method of diabetes correction in 11-14 and 30-34 weeks.

MATERIALS AND METHODS

The study included 130 women: T1DM (n = 40), T2DM (n = 35), gestational diabetes (GDM, n = 40) and the control group (n = 15). The serum concentrations of NT, 8-isoprostane, and TAC were measured by ELISA methods.

RESULTS

Elevated 8-isoprostane levels were observed in all patients with DM, but this biomarker's maximum values have been seen in T1DM and T2DM on insulin groups. A similar tendency was observed for the concentration of NT in both the 1st and 3rd trimesters. TAC levels showed a statistically relevant decrease in all DM groups compared to the control. The correlation analysis showed a direct correlation between HbA1c and serum 8-isoprostane levels in the 1st (r = .27) and 3rd (r = .3) pregnancy trimesters as well as inverse correlation with TAC level (r = -.48). Direct (NT, 8-isoprostane) and inverse correlations (TAC) were fixated for this biomarker concentration and preeclampsia rates.

CONCLUSION

DM in pregnancy is related to oxidative stress activation, which might lead to the development of adverse perinatal outcomes.

Three Day Environmental Exposure May Trigger Oxidative Stress Development and Provoke Adaptive Response Resulting in Altered Antioxidant Activity

BACKGROUND

We aimed to investigate the polluted working environment triggers oxidative stress and alter enzymatic antioxidant activity by a short-term interval.

METHODS

The experimental study, performed in 2014, involved 94 workers from the Velenje Coalmine in Slovenia, arranged into three groups according to a number of consecutive working days in a mineshaft, supported by a control group. Levels of the antioxidant enzymes (GPx, CAT, SOD) together with TAC (the combined effect of all antioxidants) and 8-isoprostane (a biological marker of oxidative stress/damage) were measured in human plasma.

RESULTS

Workers occupationally exposed for three consecutive working days had significantly increased 8-isoprostane biomarker, a parameter of oxidative stress (P<0.001). The antioxidant levels of TAC (P<0.001), CAT (P<0.001) and SOD (P<0.001) were all significantly decreased compared to a control group.

CONCLUSION

Workers in polluted working environment had significantly increased oxidative stress and altered antioxidant activity already on a third consecutive working day.

Association of Isoprostanes-Related Oxidative Stress with Vulnerability of Culprit Lesions in Diabetic Patients with Acute Coronary Syndrome

Urinary excretion of 8-iso-prostaglandin F_2α (8-iso-PGF_2α), a reliable biomarker for enhanced oxidant stress in vivo, has been described in association with diabetes and coronary heart disease. The aim of this study was to evaluate the relationship between urinary 8-iso-PGF_2α levels and the characteristics of coronary culprit lesion in diabetic patients with acute coronary syndrome (ACS). A total of 79 diabetic patients with ACS were included. iMAP intravascular ultrasound (iMAP-IVUS) was performed to evaluate the characteristics of culprit plaques. Fasting urinary 8-iso-PGF_2α level was measured and corrected by creatinine clearance. iMAP-IVUS data showed culprit plaques in high urinary 8-iso-PGF_2α level patients had a greater percentage of necrotic core and less fibrous components. High urinary 8-iso-PGF_2α levels were correlated with increased necrotic plaque components (r = 0.325, P = 0.003). Meanwhile, the presence of thin-capped fibroatheroma (50.0% versus 11.5%, P = 0.003), ruptured plaques (30.8% versus 7.7%, P = 0.035), and thrombus (38.5% versus 7.7%, P = 0.008) were significantly more frequent in the upper tertile of urinary 8-iso-PGF_2α levels than in the low tertile. Multivariate analysis showed high levels of urinary 8-iso-PGF_2α (OR 4.240, P = 0.007) was independently associated with the presence of vulnerable culprit plaque in diabetic ACS patients. Urinary 8-iso-PGF_2α also displayed a significant value in predicting vulnerable plaques in diabetic patients with ACS by constructing the receiver-operating characteristic (ROC) curve (Area under the ROC curve: 0.713, P = 0.001). Urinary 8-iso-PGF_2α levels are associated with the vulnerability of the coronary culprit lesion in diabetic patients with ACS and may provide additional information for risk assessment in suspected vulnerable patients.

Changes in oxidative stress levels during two weeks of smoking cessation treatment and their association with nutritional characteristics in Japanese smokers

Although several experimental studies have reported that oxidative stress levels decrease during smoking cessation, how they change among general smokers has yet to be completely elucidated. In the present study, a total of 23 smokers who underwent smoking cessation treatment were observed for two-week changes in their levels of 8-OHdG and 8-isoprostane. Physical and nutritional characteristics were measured at the initial patient visit, and casual urine samples were collected at the initial visit and at a follow-up visit two weeks later. Oxidative stress was measured by a high performance liquid chromatography electrochemical detector, and the two-week difference in the levels of oxidative stress was assessed according to demographic and nutrient factors. Neither the urinary level of 8-OHdG nor that of 8-isoprostane decreased, although the cotinine level was decreased at two weeks. A Two-way repeated ANOVA revealed a significant interaction for fat intake by time for the change in the 8-OHdG level (P=0.03) and significant interactions for α-tocopherol intake (P=0.03), iron intake, and carbohydrate intake (P=0.03), all of which were time-dependent for the change in the 8-isoprostane level. The 8-OHdG level decreased among smokers with a high fat intake and was increased with a low fat intake. The 8-isoprostane levels were decreased among smokers with a high carbohydrate intake and increased with a low carbohydrate intake, decreased with a low iron intake and increased with a high iron intake and decreased with a low α-tocopherol intake and increased with a high α-tocopherol intake. Although the present study failed to observe a decrease in oxidative stress levels during the two-week smoking cessation period, we hypothesize that the intake levels of specific nutrients when initiating smoking cessation treatment may predict any subsequent changes in the oxidative stress levels.

The associations of DNA methylation alterations in oxidative stress-related genes with cancer incidence and mortality outcomes: a population-based cohort study

Background

Reactive oxygen species may be involved in epigenetic gene activation or silencing. We aimed to identify CpG sites, at which DNA methylation is related to urinary 8-isoprostane levels (biomarker of lipid peroxidation) and cancer or mortality outcomes. This investigation was based on a German, population-based cohort with linkage to cancer and mortality registry data (2000–2016).

Results

Blood DNA methylation in promoter regions of 519 genes, known to be involved in pathways from oxidative stress (OS) to cancer, was obtained at the cohort's baseline examination. Inverse associations of DNA methylation at cg25365794 (ALOXE3) and cg08862778 (MTOR) with 8-isoprostane levels were observed in a derivation set (n = 1000) and validated in two independent subsets of the cohort (n = 548 and n = 741). Multivariate regression models were used to evaluate the associations of DNA methylation at the two CpG sites with lung, colorectal, prostate, breast, and overall cancer incidence as well as CVD, cancer, and all-cause mortality. DNA methylation at cg25365794 (ALOXE3) was inversely associated with lung and prostate cancer incidence. DNA methylation at cg08862778 (MTOR) was associated with a 43% lower breast cancer incidence in the top vs. bottom tertile.

Conclusion

The finding for ALOXE3 may not be causal. As ALOXE3 is mainly expressed in skin tissue, the observed association might reflect the fact that both DNA methylation at the ALOXE3 gene and urinary 8-isoprostane concentrations depend on the level of OS in tissues. Contrarily, the finding for the MTOR gene and breast cancer is biologically plausible because the MTOR protein plays an important role in PI3K/Akt signaling, which is a pathway related to cancer development and cell senescence.

Electronic supplementary material

The online version of this article (10.1186/s13148-018-0604-y) contains supplementary material, which is available to authorized users.

Urinary 8-iso-prostaglandin F2α as a risk marker for the vulnerability of culprit plaque in diabetic patients with stable coronary artery disease

We evaluated the association of urinary excretion of 8-iso-prostaglandin F_2α (8-iso-PGF_2α) with the vulnerability of culprit lesions in 156 age- and sex-matched diabetic stable coronary artery disease (CAD) patients with or without thin-capped fibroatheroma (TCFA) identified by iMAP intravascular ultrasound. Fasting urinary 8-iso-PGF_2α level was measured and corrected by creatinine clearance. Compared to non-TCFA group, patients with TCFA had higher urinary 8-iso-PGF_2α levels [114.6 (71.1, 181.5) vs. 83.0 (63.2, 138.2) pmol/mmolCr, P = 0.012]. Urinary 8-iso-PGF_2α level was positively correlated with percent necrotic volume of culprit lesion (r = 0.218, P = 0.006). High urinary 8-iso-PGF_2α level (OR 2.941, P = 0.009) was independently associated with the presence of TCFA and displayed a significant value in predicting TCFA plaques in study patients. The current study indicated that urinary 8-iso-PGF_2α may be an important surrogate marker for the vulnerability of culprit lesion in diabetic patients with CAD.

The Association of Childhood Maltreatment With Lipid Peroxidation and DNA Damage in Postpartum Women

Childhood maltreatment (CM) is associated with an increased risk for the development of psychiatric and somatic disorders in later life. A potential link could be oxidative stress, which is defined as the imbalance between the amount of reactive oxygen species (ROS) and the neutralizing capacity of anti-oxidative defense systems. However, the findings linking CM with oxidative stress have been inconsistent so far. In this study, we aimed to further explore this association by investigating biological markers of DNA and lipid damage due to oxidation in a comprehensive approach over two study cohorts of postpartum women (study cohort I and study cohort II). The severity of CM experiences (maltreatment load) was assessed in both studies using the Childhood Trauma Questionnaire. In study cohort I (N = 30), we investigated whether CM was associated with higher levels of structural DNA damage in peripheral blood mononuclear cells (PBMC) by two methods that are highly sensitive for detecting nuclear DNA strand breaks (comet assay and γH2AX staining). In study cohort II (N = 117), we then assessed in a larger cohort, that was specifically controlled for potential confounders for oxidative stress measurements, two established serum and plasma biomarkers of oxidative stress, one representing oxidative DNA and RNA damage (8-hydroxy-2'-deoxyguanosine and 8-hydroxyguanosine; 8-OH(d)G) and the other representing lipid peroxidation (8-isoprostane). In study cohort I, the analyses revealed no significant main effects of maltreatment load on cellular measures of nuclear DNA damage. The analyses of peripheral oxidative stress biomarkers in study cohort II revealed a significant main effect of maltreatment load on free 8-isoprostane plasma levels, but not on total 8-isprostane plasma levels and 8-OH(d)G serum levels. Taken together, by combining different methods and two study cohorts, we found no indications for higher oxidative DNA damages with higher maltreatment load in postpartum women. Further research is needed to investigate whether this increase in free 8-isoprostane is a marker for oxidative stress or whether it is instead functionally involved in ROS-related signaling pathways that potentially regulate inflammatory processes following a history of CM.

Expression of Hif-1α, Nf-κb, and Vegf Genes in the Liver and Blood Serum Levels of HIF-1α, Erythropoietin, VEGF, TGF-β, 8-Isoprostane, and Corticosterone in Wistar Rats with High and Low Resistance to Hypoxia

We studied the expression of Hif-1α, Nf-κb, and Vegf genes in the liver and serum levels of HIF-1α, erythropoietin, VEGF, TGF-β, 8-isoprostane, and corticosterone in Wistar rats with different resistance to hypoxia in 5 and 90 min after acute exposure to hypobaric hypoxia. In 5 min after hypoxic exposure, Hif-1α expression in the liver and serum levels of erythropoietin, VEGF, and TGF-β in high-resistant rats were higher than in low-resistant animals. In highresistant rats, the increment in expression of Nf-κb gene responsible for the control over the inflammatory processes was more pronounced than in low-resistant animals. In 90 min after hypoxic exposure, the serum levels of HIF-1α, erythropoietin, VEGF, and TGF-β returned to normal in high-resistant rats, while in low-resistant animals, an increase in 8-isoprostane and TGF-β concentrations was observed. The rats with different resistance to hypoxia were characterized by different changes in biomolecular parameters determining predilection to inflammatory diseases.

Aprotinin Impacts 8-Isoprostane after Coronary Artery Bypass Grafting

BACKGROUND AND AIMS:

The lungs participate in the modulation of the circulating inflammatory factors induced by coronary artery bypass grafting. We investigated whether aprotinin-which has been suggested to interact with inflammation-influences lung passage of key inflammatory factors after coronary artery bypass grafting.

MATERIAL AND METHODS:

A total of 40 patients undergoing coronary artery bypass grafting were randomized into four groups according to aprotinin dose: (1) high dose, (2) early low dose, (3) late low dose, and (4) without aprotinin. Pulmonary artery and radial artery blood samples were collected for the evaluation of calculated lung passage (pulmonary artery/radial artery) of the pro-inflammatory factors interleukin 6 and interleukin 8, 8-isoprostane, myeloperoxidase and the anti-inflammatory interleukin 10 immediately after induction of anesthesia (T1), 1 min after releasing aortic cross clamp (T2), 15 min after releasing aortic cross clamp (T3), 1 h after releasing aortic cross clamp (T4), and 20 h after releasing aortic cross clamp (T5).

RESULTS:

Pulmonary artery/radial artery 8-isoprostane increased in patients with high aprotinin dose as compared with lower doses (1.1 range 0.97 vs 0.9 range 1.39, p = 0.001). The main effect comparing high aprotinin dose with lower doses was significant (F(1, 38) = 7.338, p = 0.01, partial eta squared = 0.16) further supporting difference in the effectiveness of high aprotinin dose for pulmonary artery/radial artery 8-isoprostane.

CONCLUSION:

According to the pulmonary artery/radial artery equation, the impact of aprotinin on 8-isoprostane after coronary artery bypass grafting is dose dependent. Aprotinin may aid the lung passage of circulating factors toward a beneficial anti-inflammatory milieu.

Sleep duration, nightshift work, and the timing of meals and urinary levels of 8-isoprostane and 6-sulfatoxymelatonin in Japanese women

It has been hypothesized that disruption of circadian rhythms affects human health. Shift work and sleep deprivation are thought to disrupt the normal light-dark cycle, although the disruption due to shiftwork may be dependent on sleep deprivation. Both conditions have been suggested to be associated with an increased risk of cardiometabolic disorders. Non-photic environmental factors, such as the timing of eating, are also thought to regulate circadian rhythm and thus, may have effects on health, but the evidence from human studies is scarce. Oxidative stress is a risk factor of cardiometabolic disorders. Some laboratory studies suggest an involvement of circadian clock genes in the regulation of the redox system. The present study aimed to examine the association of sleeping habits, nightshift work, and the timing of meals with urinary levels of 8-isoprostane, a marker of oxidative stress, and 6-sulfatoxymelatonin, the principal metabolite of melatonin. Study subjects were 542 women who had previously attended a breast cancer mass screening in a community in Japan. Information on bedtimes and wake-up times, history of nightshift work, and the timing of meals was obtained by a self-administered questionnaire. The 8-isoprostane and 6-sulfatoxymelatonin were measured using the first morning void of urine and expressed per mg of creatinine. The geometric mean of 8-isoprostane levels was 12.1% higher in women with ≤6 hours of sleep than that in those with >8 hours of sleep on weekdays, and longer sleep duration on weekdays was significantly associated with lower urinary levels of 8-isoprostane after controlling for covariates (p for trend = 0.04). Women who were currently working the nightshift had a 33.3% higher geometric mean of 8-isoprostane levels than those who were not working nightshift (p = 0.03). Urinary 6-sulfatoxymelatonin levels were unrelated to sleep habits or nightshift work. Women who ate breakfast at irregular times had a 19.8% higher geometric mean of 8-isoprostane levels than those who ate breakfast at a regular time or who did not eat (p = 0.02). Women who ate nighttime snacks at irregular times had a 16.2% higher geometric mean of 8-isoprostane levels than those who did not eat nighttime snacks or who ate nighttime snacks at a regular time (p = 0.003). Among women who ate dinner at a regular time, earlier times for dinner were associated with higher 8-isoprostane and 6-sulfatoxymelatonin levels (p values for trends were 0.01 and 0.02, respectively). However, the times of dinner and nighttime snack are overlapping, and the time of last meal of the day was not associated with 8-isoprostane and 6-sulfatoxymelatonin levels. The time of breakfast or lunch was not associated with these biomarkers among women who ate the meal at regular times. Disturbing the rhythmicity of daily life may be associated with oxidative stress.

Epigenetic memory of oxidative stress: does nephrilin exert its protective effects via Rac1?

Aim

Nephrilin peptide, a designed inhibitor of Rictor complex (mTORC2), exerts pleiotropic protective effects in metabolic, xenobiotic and traumatic stress models. Stress can generate enduring epigenetic changes in gene function. In this work we examine the possibility that nephrilin treatment protects against acute and enduring global changes in oxidative metabolism, with a focus on the Rictor-complex-mediated activation of Rac1, a subunit of NADPH oxidase (Nox) via PKCs, Prex1 and p66shc.

Methods

Given the wide range of animal models in which nephrilin peptide has previously demonstrated effectiveness in vivo, we chose three different experimental systems for this investigation: dermal fibroblasts, renal proximal tubule epithelial cells (PTECs), and kidney tissue and urine from an animal model of burn trauma in which nephrilin was previously shown to prevent loss of kidney function.

Results

(1) Nephrilin protects dermal fibroblasts from loss of viability and collagen synthesis after ultraviolet A (UV-A) or H₂O₂ insult. (2) Nephrilin reduces reactive oxygen species (ROS) formation by H₂O₂–treated (PTECs) with or without nicotine pretreatment. Using RNA arrays and pathway analysis we demonstrate that nicotine and H₂O₂-treated PTECs specifically induced Rac1 gene networks in these cells. (3) Using kidney tissue and urine from the burn trauma model we demonstrate significant elevations of [a] 8-aminoprostane in urine; [b] kidney tissue histone modification and DNA methylation; and [c] post-transcriptional phosphorylation events consistent with Rac1 activation in kidney tissue.

Conclusion

Nephrilin protects against oxidative stress, possibly by modulating the activation of Rac1.

Suplatast tosilate protects the lung against hyperoxic lung injury by scavenging hydroxyl radicals

Prolonged exposure to hyperoxia produces extraordinary amounts of reactive oxygen species (ROS) in the lung and causes hyperoxic lung injury. Although supraphysiological oxygen is routinely administered for the management of respiratory failure, there is no effective strategy to prevent hyperoxic lung injury. In our previous study, we showed that suplatast tosilate, an asthma drug that inhibits T helper 2 (Th2) cytokines, ameliorated bleomycin-induced lung injury and fibrosis through Th2-independent mechanisms. Because bleomycin also generates ROS, we hypothesized that suplatast tosilate might have antioxidant activity and protect the lung against hyperoxic lung injury. To test this hypothesis, mice exposed to hyperoxia were given suplatast tosilate through drinking water. Treatment with suplatast tosilate significantly prolonged mouse survival, reduced the increases in the numbers of inflammatory cells, levels of the pro-inflammatory cytokines/chemokines IL-6 and MCP-1, and protein in bronchoalveolar lavage fluid, and ameliorated lung injury in histological assessment. Suplatast tosilate treatment also significantly inhibited hyperoxia-induced elevations in the levels of 8-hydroxydeoxyguanosine, a marker of oxidative DNA damage, in bronchoalveolar lavage fluid and 8-isoprostane, a marker of lipid peroxidation, in lung tissue. This finding suggests that suplatast tosilate exerts an antioxidant activity in vivo. In addition, we investigated whether suplatast tosilate has a scavenging effect on hydroxyl radical, the most reactive and harmful ROS, using electron paramagnetic resonance spin-trapping. Suplatast tosilate was shown to scavenge hydroxyl radicals in a dose-dependent manner, and its reaction rate constant with hydroxyl radical was calculated as 2.6×10¹¹M^-1S^-1, which is faster than that of several well-established antioxidants, such as ascorbate, glutathione, and cysteine. These results suggest that suplatast tosilate protects the lung against hyperoxic lung injury by decreasing the degree of oxidative stress induced by ROS, particularly by scavenging hydroxyl radicals. Suplatast tosilate might become a potential therapeutic for hyperoxic lung injury.

Increased Oxidative Stress Markers in Cerebrospinal Fluid from Healthy Subjects with Parkinson's Disease-Associated LRRK2 Gene Mutations

Mutations in the leucine-rich repeat kinase 2 (LRRK2) gene are the most frequent cause of inherited Parkinson’s disease (PD). The most common PD-associated LRRK2 mutation, G2019S, induces increased production of reactive oxygen species in vitro. We therefore hypothesized that individuals with PD-associated LRRK2 mutations might have increased concentrations of oxidative stress markers and/or decreased total antioxidant capacity (TAC) in their cerebrospinal fluid (CSF). We measured two oxidative stress markers, namely 8-hydroxy-2′-deoxyguanosine (8-OHdG) and 8-isoprostane (8-ISO), and TAC in CSF from LRRK2 mutation-bearing PD patients (LRRK2 PD = 19), sporadic PD patients (sPD = 31), and healthy control subjects with or without these mutations (LRRK2 CTL = 30, CTL = 27). 8-OHdG and 8-ISO levels were increased in LRRK2 CTL subjects, while TAC was similar between groups. 8-ISO was negatively correlated, and TAC was positively correlated, with Montreal Cognitive Assessment scores in LRRK2 PD, LRRK2 CTL, and CTL subjects. Correlations in both groups of PD patients between the two oxidative stress markers and Unified Parkinson Disease Rating Scale Total scores were weak, while TAC was negatively correlated with these scores. These findings suggest that oxidative stress may be increased in the CNS in healthy individuals with PD-associated LRRK2 mutations. Further, TAC may decrease in the CNS with the progression of PD, and when cognitive impairment is present regardless of the presence or absence of PD.

Validation of Analytical Methods for Plasma Total Antioxidant Capacity by Comparing with Urinary 8-Isoprostane Level

Although several analytical methods for measuring total antioxidant capacity (TAC) have been applied to biological samples, there were often dissimilar results due to the different principles of methods applied. Thus, this study aimed to validate four conventional analytical methods for measuring plasma TAC, including the ABTS assay, DPPH assay, FRAP assay, and ORAC assay, by comparing with urinary 8-isoprostane concentration. In addition, TAC results were compared with antioxidant enzyme activities including superoxide dismutase (SOD) and glutathione peroxidase in erythrocyte, and catalase in plasma. Plasma TAC measure by ABTS assay was strongly correlated with the result by FRAP assay. Plasma TAC by FRAP and ORAC assays were negatively correlated with erythrocyte SOD activity. The agreement among the four TAC assay methods and 8-isoprostane was determined using 95% prediction limits of linear regression, expressed as the mean of 8-isoprostane ± 95% prediction limits. The ABTS method better agreed with 8-isoprostane than the other methods, demonstrating narrow prediction of limits. Furthermore, only plasma TAC determined by the ABTS assay was inversely correlated with urinary 8-isoprostane (r = -0.35, p < 0.05). In summary, the ABTS assay would be an appropriate method to measure overall plasma antioxidant capacity and predict the body's antioxidant status.

Prenatal phthalate exposure and 8-isoprostane among Mexican-American children with high prevalence of obesity

Oxidative stress has been linked to many obesity-related conditions among children including cardiovascular disease, diabetes mellitus and hypertension. Exposure to environmental chemicals such as phthalates, ubiquitously found in humans, may also generate reactive oxygen species and subsequent oxidative stress. We examined longitudinal changes of 8-isoprostane urinary concentrations, a validated biomarker of oxidative stress, and associations with maternal prenatal urinary concentrations of phthalate metabolites for 258 children at 5, 9 and 14 years of age participating in a birth cohort residing in an agricultural area in California. Phthalates are endocrine disruptors, and in utero exposure has been also linked to altered lipid metabolism, as well as adverse birth and neurodevelopmental outcomes. We found that median creatinine-corrected 8-isoprostane concentrations remained constant across all age groups and did not differ by sex. Total cholesterol, systolic and diastolic blood pressure were positively associated with 8-isoprostane in 14-year-old children. No associations were observed between 8-isoprostane and body mass index (BMI), BMI Z-score or waist circumference at any age. Concentrations of three metabolites of high molecular weight phthalates measured at 13 weeks of gestation (monobenzyl, monocarboxyoctyl and monocarboxynonyl phthalates) were negatively associated with 8-isoprostane concentrations among 9-year olds. However, at 14 years of age, isoprostane concentrations were positively associated with two other metabolites (mono(2-ethylhexyl) and mono(2-ethyl-5-carboxypentyl) phthalates) measured in early pregnancy. Longitudinal data on 8-isoprostane in this pediatric population with a high prevalence of obesity provides new insight on certain potential cardiometabolic risks of prenatal exposure to phthalates.

Differential BPA levels in sewage wastewater effluents from metro Detroit communities

The endocrine disruptor Bisphenol A (BPA) is ubiquitous in both aquatic and surface sediment environments because it is continuously released into sewage wastewater effluent. The measurement of BPA at wastewater treatment plants is rarely performed even though the United States Environmental Protection Agency (EPA) states that current levels of environmental BPA could be a threat to aquatic organisms. Therefore, the aims of this study were to measure BPA levels in sewage wastewater at different collection points over a 1-year period and to compare the levels of BPA to 8-isoprostane, a human derived fatty acid, found in sewage wastewater. We analyzed pre-treated sewage samples collected from three source points located in different communities in the metropolitan Detroit area provided by the Detroit Water and Sewerage Department. Human urine samples were also used in the study. BPA and 8-isoprostane were measured using ELISA kits from Detroit R&D, Inc. BPA levels from the same collection point oscillated more than 10-fold over 1 year. Also, BPA levels fluctuated differentially at each collection point. Highly fluctuating BPA values were confirmed by LC/MS/MS. The concentration of BPA in sewage wastewater was ~100-fold higher than the concentration of 8-isoprostane, while urinary concentration was ~20-fold higher. Thus, BPA levels discharged into the sewage network vary among communities, and differences are also observed within communities over time. The difference in BPA and 8-isoprostane levels suggest that most of the BPA discharged to sewage wastewater might be derived from industries rather than from human urine. Therefore, the continuous monitoring of BPA could account for a better regulation of BPA release into a sewage network.

Serum 8-isoprostane levels and paraoxonase 1 activity in patients with stage I multiple myeloma

OBJECTIVE

Multiple myeloma (MM) is a plasma cell malignancy comprising 15% of hematological malignancies. Many studies have assessed the relationship between free radicals and tumor progression or cancer risk. We aimed to evaluate the antioxidant activity of paraoxonase 1 (PON1), arylesterase (ARE), and 8-isoprostane in patients with stage I MM.

MATERIALS AND METHODS

Spectrophotometric assays of serum PON1 and ARE activities in addition to serum 8-isoprostane level were performed in 34 patients newly diagnosed with stage I MM as compared to 35 age- and sex-matched individuals who comprised the healthy control group.

RESULTS

A significant reduction was found in the activities of PON1 and ARE (for both, P < 0.001) in the patient group. The ratio of PON1/high-density lipoprotein was significantly lower in the MM patient group than in the control group (P < 0.001), while 8-isoprostane levels compared with the control group were significantly higher (P < 0.001), observations that may indicate an increase in oxidative stress in stage I MM patients.

CONCLUSION

A decrease in PON1 activity and increase in 8-isoprostane serum activities in patients may indicate the importance of lipid peroxidation in MM disease. Oxidative stress and especially lipid peroxidation could reduce the antioxidant activity of PON1 and ARE in MM patients and could be considered as factors in the pathogenesis of MM disease.

Cysteinyl leukotriene correlated with 8-isoprostane levels as predictive biomarkers for sensory dysfunction in autism

Background

Autism is a neurodevelopmental disorder that clinically presented as cognitive deficits, social impairments and sensory dysfunction. An increasing body of evidence has shown that oxidative stress and inflammation are involved in the pathophysiology of autism. Recording biomarkers as measure of the severity of autistic features might help in understanding the pathophysiology of autism.

Methods

This study investigates the plasma levels of 8-isoprostane and Cysteinyl leukotrienes (CysLTs) in 44 autistic children and 40 healthy controls. The recruited autistic patients were assessed for behavior, cognitive and sensory deficits by using different autism severity rating scales, including the Childhood Autism Rating Scales (CARS), Social responsiveness scale (SRS) and Short Sensory Profile (SSP). Receiver Operating Characteristics analysis (ROC) of the obtained data was performed to measure the predictive value of 8-isoprostane and Cysteinyl leukotrienes (CysLTs) as oxidative stress- related parameters. Pearson’s correlations between the measured parameters was also performed.

Results

The concentrations of 8-isoprostane and CysLTs in autistic patients were significantly higher than those in controls. While cognitive and social impairments did not show any significant differences, the SSP results were strongly correlated with the levels of both of the biomarkers assessed. However, autistic children showed improvements in oxidative stress status (as determined by 8-isoprostane levels) at increasing ages.

Conclusion

This study indicates that 8-isoprostane and CysLTs can be used as markers for the early recognition of autistic patients through sensory deficits phenotypes which might help early intervention.

Age-Related Decrease in Heat Shock 70-kDa Protein 8 in Cerebrospinal Fluid Is Associated with Increased Oxidative Stress

Age-associated declines in protein homeostasis mechanisms (“proteostasis”) are thought to contribute to age-related neurodegenerative disorders. The increased oxidative stress which occurs with aging can activate a key proteostatic process, chaperone-mediated autophagy. This study investigated age-related alteration in cerebrospinal fluid (CSF) concentrations of heat shock 70-kDa protein 8 (HSPA8), a molecular chaperone involved in proteostatic mechanisms including chaperone-mediated autophagy, and its associations with indicators of oxidative stress (8-hydroxy-2′-deoxyguanosine [8-OHdG] and 8-isoprostane) and total anti-oxidant capacity. We examined correlations between age, HSPA8, 8-OHdG, 8-isoprostane, and total antioxidant capacity (TAC) in CSF samples from 34 healthy subjects ranging from 20 to 75 years of age. Age was negatively associated with HSPA8 (ρ = –0.47; p = 0.005). An age-related increase in oxidative stress was indicated by a positive association between age and 8-OHdG (ρ = 0.61; p = 0.0001). HSPA8 was moderately negatively associated with 8-OHdG (ρ = –0.58; p = 0.0004). Age and HSPA8 were weakly associated with 8-isoprostane and TAC (range of ρ values: –0.15 to 0.16). Our findings in this exploratory study suggest that during healthy aging, CSF HSPA8 may decrease, perhaps due in part to an increase in oxidative stress. Our results also suggest that 8-OHdG may be more sensitive than 8-isoprostane for measuring oxidative stress in CSF. Further studies are indicated to determine if our findings can be replicated with a larger cohort, and if the age-related decrease in HSPA8 in CSF is reflected by a similar change in the brain.

The effects of genistein supplementation on fructose induced insulin resistance, oxidative stress and inflammation

AIMS

This experimental study was designed to investigate the effects of 10weeks genistein administration on oxidative stress and inflammation in serum and liver of rats fed with fructose.

MAIN METHODS

6-8weeks old, 40 male Sprague-Dawley rats were included. Group 1 (control) was fed with standard chow food and 100μl/kg/day/rat dimethyl sulfoxide (DMSO) administered subcutaneously; group 2 (genistein) with standard chow food and 0.25mg/kg/day/rat genistein; group 3 (fructose) with standard chow food and drinking water 20% fructose, group 4 (fructose+genistein) with standard chow food, drinking water with 20% fructose and 0.25mg/kg/day/rat genistein. TNF-α, IL-6, visfatin as inflammatory markers and 8-isoprostane as a oxidative stress marker were measured by ELISA, glucose, triglyceride, total cholesterol, LDL-cholesterol and HDL-cholesterol by enzymatic colorimetric method, AST and ALT by kinetic UV method.

KEY FINDINGS

Significantly high 8-isoprostane levels in serum (p<0.001) and liver (p<0.05) in group 3 compared to control group indicate that presence of oxidative stress. Significantly high TNF-α and IL-6 levels in serum (p<0.05) and liver (p<0.01) and visfatin levels in serum (p<0.001) of group 3 indicate inflammation accompanying insulin resistance and oxidative stress. Genistein administration to fructose group causes a significant decrease in HOMA-IR (p<0.001) and LDLC (p<0.05) level. Significantly lower serum 8-isoprostane (p<0.01) level indicates the antioxidant effect of genistein and significantly lower liver TNF-α (p<0.01), serum, liver IL-6(p<0.01) and serum visfatin (p<0.01) levels reflect the antiinflammatory effects of genistein.

SIGNIFICANCE

Genistein administration to rats fed with fructose causes an ameliorating effect on HOMA-IR values and lipid status markers in addition to its antioxidant and antiinflammatory effects.

Dynamics of urinary oxidative stress biomarkers: 8-hydroxy-2'-deoxyguanosine and 8-isoprostane in uterine leiomyomas

BACKGROUND

Perturbations of antioxidant levels and lipid peroxidation, but not oxidative DNA damage as a biomarker of oxidative stress have been reported in uterine myoma patients.

AIMS

The study aimed at examining the patterns and influence of oxidative stress/damage biomarkers, 8-isoprostane (8-IP) and 8-hydroxy-2'-deoxyguanosine (8OHdG), on the ovulatory and luteal phases of normal and fibroid women.

SETTINGS AND DESIGN

Twenty women diagnosed of fibroids (1-5 years) and 20 nonfibroid women were age-matched. Selection was randomly done at the National Obstetrics and Gynaecology Department.

SUBJECTS AND METHODS

Three successive samples of urine were taken at 8:00 am on the 14(th), 18(th), and 21(st) days of the menstrual cycle. Mid-stream urine was collected from subjects, after they had cleaned genitals. The samples were kept in an ice chest, transported to the laboratory, and stored at - 70°C until the time of analysis. Samples were analyzed by ELISA technique using commercial kits for 8OHdG and 8-IP. Results were calculated using a computer program.

STATISTICAL ANALYSIS USED

Statistical Package for Social Sciences, version 20.0, was used for data management and statistical analysis. The results were expressed as mean ± standard deviation. Differences in continuous data were compared using Student's t-test (two groups) and one-way ANOVA (three or more groups) followed by Bonferroni post hoc test. Relationship between variables was ascertained by Spearman's correlation coefficient. All results were considered significant at 5% level of probability.

RESULTS

Significant differences were observed between day 14 and day 21 in control and test groups' estrogen levels (P = 0.0047 and P = 0.004, respectively). Significant progesterone differences were observed between control and test groups on the same days (P = 0.002 and P = 0.001, respectively). A positive correlation was observed between day 21 estrogen and progesterone levels (P = 0.0003) of the control group. Test group had higher levels of 8-IP and 8OHdG than control groups on day 21, with 8OHdG at maximum in the test group but minimum in the control group. The influence of 8OHdG was seen by a negative correlation with estrogen and progesterone on day 21 (P = 0.0002) and a positive correlation between 8OHdG and 8-IP on the same day in the test group. Finally, there was a positive correlation between 8-IP and 8OHdG on day 14, but a negative correlation on day 21 (P = 0.0016).

CONCLUSIONS

Oxidative damage was absent in the control group but was very much present in the test group on day 14 and day 21 with progesterone and estrogen acting in concert with oxidative damage biomarkers. An inverse pattern of biomarkers was observed between control and fibroid groups. Oxidative stress biomarkers influenced hormonal levels and pattern of the fibroid group.

The onset of lipid peroxidation in rheumatoid arthritis: consequences and monitoring

Several epidemiological studies propose the association of rheumatoid arthritis (RA) with oxidative stress. The aim of this study was to estimate the possible onset of systemic lipid peroxidation in RA patients and its relevance for pathophysiology and monitoring of RA. Seventy-three patients with RA and 73 healthy subjects were included in the study. Lipid peroxidation was estimated by the measurement of 4-hydroxynonenal (4-HNE), 4-hydroxyhexenal, malondialdehyde, acrolein, crotonaldehyde, 4-oxononenal, and isoprostanes (8-isoPGF(2α)) levels. Cytosolic phospholipase A(2) (cPLA(2)), platelet-activating factor acetylhydrolase (PAF-AH) and glutathione peroxidase (GSH-Px) activities and vitamin E levels were also determined. In parallel, the plasma levels of phospholipid arachidonic acid (AA), linoleic acid (LA), and 4-HNE-protein adducts were monitored. Plasma of RA patients had increased vitamin E levels, but decreased GSH-Px activity and phospholipid AA and LA levels when compared to levels of the healthy subjects. The levels of aldehydes were significantly increased in the plasma of the RA patients and even more in urine. Significant increases in HNE-modified protein adducts was observed for the first time in plasma of RA patients, while the activities of PAF-AH and cPLA(2) were decreased. The 8-isoPGF(2α) levels were 9-fold higher in plasma and 3-fold higher in urine of RA patients and were related to the severity of disease. The levels of lipid peroxidation products in plasma and in urine suggest the relationship between lipid peroxidation and the development of RA. Additionally, urine 8-isoPGF(2α), plasma 4-HNE and 4-HNE-protein adducts appear to be convenient biomarkers to monitor progression of this autoimmune disease.

Sex-specific effect of antenatal betamethasone exposure on renal oxidative stress induced by angiotensins in adult sheep

Prenatal glucocorticoid administration in clinically relevant doses reduces nephron number and renal function in adulthood and is associated with hypertension. Nephron loss in early life may predispose the kidney to other insults later but whether sex influences increases in renal susceptibility is unclear. Therefore, we determined, in male and female adult sheep, whether antenatal glucocorticoid (betamethasone) exposure increased 8-isoprostane (marker of oxidative stress) and protein excretion after acute nephron reduction and intrarenal infusions of angiotensin peptides. We also examined whether renal proximal tubule cells (PTCs) could contribute to alterations in 8-isoprostane excretion in a sex-specific fashion. In vivo, ANG II significantly increased 8-isoprostane excretion by 49% and protein excretion by 44% in male betamethasone- but not in female betamethasone- or vehicle-treated sheep. ANG-(1-7) decreased 8-isoprostane excretion but did not affect protein excretion in either group. In vitro, ANG II stimulated 8-isoprostane release from PTCs of male but not female betamethasone-treated sheep. Male betamethasone-exposed sheep had increased p47 phox abundance in the renal cortex while superoxide dismutase (SOD) activity was increased only in females. We conclude that antenatal glucocorticoid exposure enhances the susceptibility of the kidney to oxidative stress induced by ANG II in a sex-specific fashion and the renal proximal tubule is one target of the sex-specific effects of antenatal steroids. ANG-(1-7) may mitigate the impact of prenatal glucocorticoids on the kidney. P47 phox activation may be responsible for the increased oxidative stress and proteinuria in males. The protection from renal oxidative stress in females is associated with increased SOD activity.

8-Isoprostane in exhaled breath condensate of patients with non-small cell lung cancer: the effect of chemotherapy

AIM

The aim of the study was to evaluate the exhaled breath condensate (EBC) levels of a valid oxidative stress marker, 8-isoprostane, before and after chemotherapy, in patients with non small cell lung cancer (NSCLC) in correlation with the extent of the disease and response to treatment.

PATIENTS AND METHODS

Forty-five patients with inoperable NSCLC were initially enrolled in the study. Twenty-nine of them were finally evaluated in regards to 8-isoprostane levels in EBC before and after chemotherapy.

RESULTS

8-Isoprostane levels were significantly lower after chemotherapy (p=0.014). Further analysis showed that the differences were mainly attributed: a) to the extent of the disease, with patients diagnosed with up to locally advanced disease (stages IB-IIIB) having significantly lower EBC 8-isoprostane levels post-chemotherapy (p=0.031); and b) to the response to treatment, with patients evaluated with partial response to treatment having significantly lower EBC 8-isoprostane levels post-chemotherapy (p=0.02).

CONCLUSION

In this prospective study, we showed that 8-isoprostane might represent a biomarker in NSCLC, reflecting both response to chemotherapy, as well as the extent of the disease.

Maternal plasma levels of interleukin-6, C-reactive protein, vitamins C, E and A, 8-isoprostane and oxidative status in women with preterm premature rupture of membranes

OBJECTIVE

Preterm premature rupture of membranes (PPROM) is associated with significant maternal and perinatal morbidity. This study examined maternal oxidative stress in PPROM.

METHODS

This was a prospective cross-sectional study conducted in a university hospital. A total of 72 pregnant women were recruited into two groups, those with PPROM (38 cases) and those without PPROM (34 controls) matched for gestational age. Plasma interleukin-6, C-reactive protein, vitamins C, E and A, 8-isoprostane, total oxidant status (TOS) and antioxidant status (TAS) were determined for all study participants and the data were compared between the PPROM and control groups.

RESULTS

Both case and control groups were comparably matched in age, parity, gestational age and smoking status. There was a significant association between low 8-isoprostane, low vitamin C and high total oxidant status and the occurrence of PPROM (p < 0.001).

CONCLUSIONS

Plasma vitamin C and 8-isoprostane levels were lower and TOS higher in women with PPROM. Further research is needed to identify robust biological markers for the prevention and also prognosis of PPROM.

Pyruvate-enriched resuscitation: metabolic support of post-ischemic hindlimb muscle in hypovolemic goats

Tourniquet-imposed ischemia-reperfusion of extremities generates reactive oxygen and nitrogen species (RONS), which can disrupt intermediary metabolism and ATP production. This study tested the hypothesis that fluid resuscitation with pyruvate, a natural antioxidant and metabolic fuel, ameliorates the deleterious effects of ischemia-reperfusion on intermediary metabolism in skeletal muscle. Anesthetized male goats (∼25 kg) were bled to a mean arterial pressure of 48 ± 1 mmHg and then subjected to 90 min hindlimb ischemia with a tourniquet and femoral crossclamp, followed by 4-h reperfusion. Lactated Ringers (LR) or pyruvate Ringers (PR) was infused intravenous for 90 min, from 30 min ischemia to 30 min reperfusion, to deliver 0.05 mmol kg(-1) min(-1) lactate or pyruvate. Time controls (TC) underwent neither hemorrhage nor hindlimb ischemia. Lipid peroxidation product 8-isoprostane, RONS-sensitive aconitase and creatine kinase activities, antioxidant superoxide dismutase activity, and phosphocreatine phosphorylation potential ([PCr]/[{Cr}{P(i)}]), an index of tissue energy state, were measured in reperfused gastrocnemius at 90 min resuscitation (n = 6 all groups) and 3.5 h post-resuscitation (n = 8 TC, 9 LR, 10 PR). PR more effectively than LR suppressed 8-isoprostane formation, prevented inactivation of aconitase and creatine kinase, doubled superoxide dismutase activity, and augmented [PCr]/([Cr][P(i)]). Pyruvate-enriched Ringer's is metabolically superior to Ringer's lactate for fluid resuscitation of tourniqueted muscle.

Depression Correlates with Increased Plasma Levels of Inflammatory Cytokines and a Dysregulated Oxidant/Antioxidant Balance in HIV-1-Infected Subjects Undergoing Antiretroviral Therapy

OBJECTIVE

Depression is the most common psychiatric diagnosis in the HIV/AIDS population and represents a risk factor for disease progression. Since HIV-1 infection is characterized by immunologic and metabolic disturbances, we want to study the effects of depression on different components related to pro-inflammatory and oxidative stress markers. We hypothesize that depression will lead to increased pro-inflammatory cytokine levels and altered antioxidant/oxidant balance.

METHODS

We included males and females who were ≥21 years of age, whose HIV-1 sero-status was confirmed by Western Blot, and who were currently undergoing antiretroviral treatment. Patients completed the participation consent form, a socio-demographic survey, and the Patient Health Questionnaire-9 (PHQ-9) for depression assessment. We isolated the plasma from participants' blood samples for viral load analysis (RT-PCR), T-cell counts (flow cytometry), and hematological parameters. A cytokine magnetic bead panel was used to measure interleukin-15 (IL-15), interferon gamma-induced protein 10 (IP-10), IL-12 and granulocyte colony-stimulating factor (G-CSF) levels. We also performed assays to determine the antioxidant activity of superoxide dismutase (SOD) and catalase and to measure the lipid peroxidation levels using malondialdehyde (MDA) and 8-isoprostane assays. Statistical comparisons and correlations at 5% level of significance were determined.

RESULTS

Our results show that subjects with mild/moderate to severe depression as assessed by PHQ-9 had a significantly decreased adherence to anti-retroviral treatment. Subjects with depression also had significantly lower levels of white blood cells (WBC) and platelets (PLT) than did the non-depressed group. The HIV⁺ subjects with depression had increased levels of IL-15, IP-10, IL-12 p40/p70 and G-CSF compared to their non-depressed counterparts. The latter had increased MDA and 8-isoprostane levels.

CONCLUSIONS

Our results suggest that HIV⁺ subjects with depressive symptoms have higher levels of inflammation and altered oxidant/antioxidant balance. Although the groups were small, this study strengthens the hypothesis that alterations in cytokines are associated with the mechanisms underlying depression symptoms.

Exhaled breath 8-isoprostane as a marker of asthma severity

INTRODUCTION

Oxidative stress is a non-specific feature of airway inflammation in asthmatics. 8-Isoprostane (8-IP), a prostaglandin-F(2α) isomer, is a relatively new marker of oxidative stress and may be measured in exhaled breath condensate (EBC) of patients with asthma. This research study aimed to evaluate the usefulness of EBC 8-IP as a marker of severity and control of severe adult asthma.

MATERIAL AND METHODS

Twenty-seven severe, never-smoking asthmatics were studied. According to positive or negative reversibility testing, this group was subdivided into reversible and irreversible asthma groups. All participants were observed for 8 weeks during which they completed daily diary observations including day and night symptoms, number of awakenings, peak expiratory flow (PEF) variability, daily rescue medication usage and oral steroids consumption. They attended the clinic 3 times and on these occasions spirometry assessments, EBC collection and asthma control tests (ACT) were done. Two control groups were included: 11 healthy never-smokers and 16 newly diagnosed and never-treated, non-smoking mild asthmatics.

RESULTS

There were no statistically significant differences between severe asthma and healthy control or never-treated asthma groups in concentrations of EBC 8-IP (median and interquartile range: 4.67; 2.50-27.92 vs. 6.93; 2.5-12.98 vs. 3.80; 2.50-10.73, respectively). No correlations were found between EBC 8-IP and asthma control parameters, such as ACT results, night and day symptoms, consumption of rescue medication, percentage of days free of oral steroids, PEF diurnal variation, lung function test results, forced expiratory volume in the 1 s reversibility, and markers of systemic inflammation.

CONCLUSIONS

Our study results suggest that EBC 8-IP measurements are not useful for asthma monitoring.