Assessing the antioxidative status in critically ill patients

Vanin1 (VNN1) in chronic diseases: Future directions for targeted therapy

Vanin1 (VNN1) is an exogenous enzyme with pantetheinase activity that mainly exerts physiological functions through enzyme catalysis products, including pantothenic acid and cysteamine. In recent years, the crosstalk between VNN1 and metabolism and oxidative stress has attracted much attention. As a result of the ability of VNN1 to affect multiple metabolic pathways and oxidative stress to exacerbate or alleviate pathological processes, it has become a key component of disease progression. This review discusses the functions of VNN1 in glucolipid metabolism, cysteamine metabolism, and glutathione metabolism to provide perspectives on VNN1-targeted therapy for chronic diseases.

Real-time monitoring of vitamin C levels in trauma patients by electron-spin resonance spectrometry

BACKGROUND

In critically ill patients, healthy vitamin C levels are important to avoid an imbalance in reactive oxygen species. To achieve this, oxidative stress levels in emergency patients need to be accurately measured in real-time. However, normally, reactive oxygen/nitrogen species are short-lived, rendering measurement difficult; moreover, measurement of relatively stable antioxidants and other oxidative stress markers in real-time is challenging. Therefore, we used electron-spin resonance spectrometry (ESR) to assess vitamin C levels, clarify their relationship with patients' severity, and establish more effective vitamin C therapy in critically ill patients.

METHODS

We studied 103 severely ill emergency patients and 15 healthy volunteers. Vitamin C radical (VCR/dimethyl sulfoxide [DMSO]) values were analyzed in arterial blood samples by ESR at admission and once daily thereafter during the acute recovery phase. Severity scores were calculated. The relationship between these scores and VCR/DMSO values and chronological changes in VCR/DMSO values were analyzed.

RESULTS

Serum VCR/DMSO values were significantly lower in critically ill patients than in healthy volunteers (0.264 ± 0.014 vs. 0.935 ± 0.052, p < 0.05), particularly in the severe trauma group and the cardiopulmonary arrest/post-cardiac arrest syndrome group. VCR/DMSO values and various severity scores did not correlate at admission; however, they correlated with SOFA scores from days 2-6. VCR/DMSO values remained low from the first measurement day through Day 6 of illness.

CONCLUSIONS

Vitamin C levels were low at admission, remained low with conventional nutritional support, and did not correlate with the initial patient's severity; however, they correlated with patients' severity after admission. Some patients had normal vitamin C levels. Therefore, vitamin C levels should be measured in real-time and supplemented if they are below normal levels.

TRIAL REGISTRATION

Retrospectively registered.

Factors Associated with Interruptions of Enteral Nutrition and the Impact on Macro- and Micronutrient Deficits in ICU Patients

BACKGROUND AND AIM

Feeding interruptions in critical care patients are often unjustified. We aimed to determine the causes, duration, and frequency of enteral nutrition interruptions (ENIs) and to assess macronutrients and antioxidant deficits according to European Society of Parenteral Enteral Nutrition (ESPEN) guidelines.

METHODS

We prospectively enrolled Intensive Care Unit (ICU) patients admitted for more than 48 h with an inability to orally eat from April to December 2019. The type of enteral nutrition, the number of calories administered, the time of feeding initiation, the reasons for delaying feeding, and the causes for ENI were recorded.

RESULTS

81 patients were enrolled, with a median duration of ENIs of 5.2 (3.4-7.4) hours/day. Gastric residual volume (GRV) monitoring-a highly controversial practice-was the most common cause of ENI (median duration 3 (2.3-3) hours/day). The mean energy intake was 1037 ± 281 kcal/day, while 60.5% of patients covered less than 65% of the total energy needs (1751 ± 295 kcal/day, according to mean Body Mass Index (BMI)). The median daily protein intake did not exceed 0.43 ± 0.3 gr/kg/day of the actual body weight (BW), whereas ESPEN recommends 1.3 gr/kg/day for adjusted BW (p < 0.001). The average administration of micronutrients and antioxidants (arginine, selenium, zinc, vitamins) was significantly less than the dietary reference intake (p < 0.01).

CONCLUSION

ENIs lead to substantial caloric, protein, and antioxidant deficits.

The effects of selenium supplementation on inflammatory markers in critically ill patients

Abstract

Low serum selenium (Se) levels have been shown in critical illness, which is associated with poor clinical outcomes and a higher mortality rate. Se plays an important role in inflammation and oxidative stress. Since the overproduction of inflammatory cytokines and increased oxidative stress is a major component of critical illnesses, its supplementation has been demonstrated to have promising effects on critically ill patients. This study aims to review the evidence regarding the effects of Se supplementation on inflammatory and oxidative markers in critically ill patients. The literature review highlights alterations of inflammatory markers, including procalcitonin, leukocyte count, albumin, prealbumin, C-reactive protein (CRP), inflammatory cytokines, and cholesterol following Se supplementation in critically ill patients. Besides, the antioxidant properties of Se due to its presence in the structure of several selenoenzymes have been reported.

Article highlights

Low serum Se level have been shown in critical illness, which is associated with poor clinical outcome and higher mortality rate.

Se plays an important role in inflammation and oxidative stress.

Se supplementation can have promising effects by alterations of inflammatory markers and its antioxidant properties for critically ill patients.

Dietary diversity, diet quality, and oxidative stress in older adults

This cross-sectional study aimed to explore the relationship between diet quality, dietary diversity, and oxidative stress levels in older adults in parts of the Ningxia Hui Autonomous Region in northwestern China. A total of 335 participants voluntarily participated in the study from April to July 2021. Laboratory tests and questionnaires were used to obtain general characteristics, dietary conditions, and indicators of oxidative stress. The dietary diversity scores of the participants were 5.20±1.39, the diet quality indices were 56.91±11.14, and most had poor diet quality. The levels of the oxidative stress markers malondialdehyde, superoxide dismutase, 8-iso-prostaglandin F2α, and total antioxidant capacity were 4.77±1.77, 40.33±9.85, 763.10±245.41, and 1.02±0.14, respectively. The results showed that the diet quality scores of participants were related to dietary diversity and whether the scores passed or not was significantly related to total antioxidant capacity.

Carotenoids in Human SkinIn Vivo: Antioxidant and Photo-Protectant Role against External and Internal Stressors

The antioxidant system of the human body plays a crucial role in maintaining redox homeostasis and has an important protective function. Carotenoids have pronounced antioxidant properties in the neutralization of free radicals. In human skin, carotenoids have a high concentration in the stratum corneum (SC)-the horny outermost layer of the epidermis, where they accumulate within lipid lamellae. Resonance Raman spectroscopy and diffuse reflectance spectroscopy are optical methods that are used to non-invasively determine the carotenoid concentration in the human SC in vivo. It was shown by electron paramagnetic resonance spectroscopy that carotenoids support the entire antioxidant status of the human SC in vivo by neutralizing free radicals and thus, counteracting the development of oxidative stress. This review is devoted to assembling the kinetics of the carotenoids in the human SC in vivo using non-invasive optical and spectroscopic methods. Factors contributing to the changes of the carotenoid concentration in the human SC and their influence on the antioxidant status of the SC in vivo are summarized. The effect of chemotherapy on the carotenoid concentration of the SC in cancer patients is presented. A potential antioxidant-based pathomechanism of chemotherapy-induced hand-foot syndrome and a method to reduce its frequency and severity are discussed.

Citrus reticulata Blanco peel extract ameliorates hepatic steatosis, oxidative stress and inflammation in HF and MCD diet-induced NASH C57BL/6 J mice

Excessive lipid deposition, oxidative stress and inflammation in liver tissues are regarded as crucial inducers of nonalcoholic steatohepatitis (NASH), which is the most frequent chronic liver disease and closely related to obesity and insulin resistance. In this work, the preventive and therapeutic effects of Citrus reticulata Blanco (Jizigan) peel extract (JZE) on NASH induced by high fat (HF) diet and methionine choline-deficient (MCD) diet in C57BL/6 mice were investigated. We found that daily supplementation of JZE with an HF diet effectively ameliorated glucose tolerance and insulin resistance. In addition, the key indexes of lipid profiles, oxidative stress, hepatic steatosis and inflammatory factors were also ameliorated in both NASH mouse models. Furthermore, JZE treatment activated nuclear factor erythroid-2-related factor 2 (Nrf2) in the livers of diet- induced NASH mice. Our study suggests that JZE might alleviate NASH via the activation of Nrf2 signaling and that citrus Jizigan could be used as a dietary therapy for NASH and related metabolic syndrome.

Reduced FXR Target Gene Expression in Copper-Laden Livers of COMMD1-Deficient Dogs

Wilson’s disease (WD), an autosomal recessive disorder, results in copper accumulation in the liver as a consequence of mutations in the gene ATPase copper transporting beta (ATP7B). The disease is characterized by chronic hepatitis, eventually resulting in liver cirrhosis. Recent studies have shown that dysregulation of nuclear receptors (NR) by high hepatic copper levels is an important event in the pathogenesis of liver disease in WD. Intracellular trafficking of ATP7B is mediated by COMMD1 and, in Bedlington terriers, a mutation in the COMMD1 gene results in high hepatic copper levels. Here, we demonstrate a reduced Farnesoid X nuclear receptor (FXR)-activity in liver biopsies of COMMD1-deficient dogs with copper toxicosis, a unique large animal model of WD. FXR-induced target genes, small heterodimer partner (SHP), and apolipoprotein E (ApoE) were down-regulated in liver samples from COMMD1-deficient dogs with hepatic copper accumulation. In contrast, the relative mRNA levels of the two CYP-enzymes (reduced by FXR activity) was similar in both groups. These data are in line with the previously observed reduced FXR activity in livers of ATP7B−/− mice and WD patients. Therefore, these data further corroborate on the importance of the COMMD1-deficient dogs as a large animal model for WD.

Antioxidant supplementation during illness in dogs: effect on oxidative stress and outcome, an exploratory study

OBJECTIVES

To assess whether combination antioxidant supplementation for 30 days in systemically ill dogs alters antioxidant status, degree of lipid peroxidation, clinical score and survival.

MATERIALS AND METHODS

Forty client-owned systemically-ill hospitalised dogs were eligible for inclusion. Dogs were randomised to no supplementation (NS; n=19) or supplementation with N-acetylcysteine/S-adenosylmethionine/silybin and vitamin E (AS; n=20) for 30 days. Clinical score and oxidative biomarkers including glutathione, cysteine, vitamin E, selenium and urine isoprostanes/creatinine (F₂ -IsoPs/Cr) were determined on days 0 and 30. Glutathione, cysteine, vitamin E and urine F₂ -IsoPs/Cr were quantified by high-performance liquid chromatography, and selenium concentrations determined using atomic absorption spectroscopy.

RESULTS

Thirty-two dogs completed the study (NS, n=16; AS, n=16). Vitamin E concentrations were significantly greater in the supplemented compared to the non-supplemented group. No other markers of oxidative stress significantly changed with supplementation. There was no difference in Day 30 clinical scores or survival between the two groups.

CLINICAL SIGNIFICANCE

In this population of systemically-ill hospitalised dogs, combination antioxidant supplementation did not alter redox state or clinical outcome.

Rapid decreases of key antioxidant molecules in critically ill patients: A personalized approach

BACKGROUND & AIMS

Oxidative stress is regarded a key component of critical illness and has been associated with poor prognosis in Intensive Care Unit (ICU) patients. Diverse antioxidant treatments have been applied to combat oxidative stress in ICU, yet the results were typically disappointing. An explanation for this failure is that all studies utilized antioxidants indiscriminately and did not take into account the antioxidant profile of the patients. The aim of the present study was to investigate whether critically ill patients experience different insufficiencies in three major antioxidants with a "recycling" redox relationship (vitamin C, vitamin E and glutathione) and in the central reductant molecule of many enzymatic antioxidants (NADPH).

METHODS

Sixty mechanically-ventilated adult medical critically ill patients (age: 63.5 ± 17.1; APACHE II score: 21.2 ± 7.4; Glasgow Coma Scale: 6.2 ± 1.9) were enrolled in the study, while 20 healthy age-matched volunteers served as control group. The antioxidant profile and the level of systemic oxidative stress (F₂-isoprostanes) were measured at ICU admission and at days 1 and 7.

RESULTS

The majority of the ICU patients developed rapid and severe antioxidant insufficiencies (by exhibiting less than 50% of the control values) in one (22/60), two (7/60) or three (2/60) of the antioxidants measured, despite the almost similar levels of oxidative stress.

CONCLUSIONS

The wide heterogeneity in antioxidant decreases in response to ICU stay highlights the importance of patient stratification when planning to apply antioxidant treatments and indicates that the successful delivery of personalized clinical nutrition may depend on our ability to identify "responsive" phenotypes.

Comet assay and its use for evaluating oxidative DNA damage in some pathological states

The comet assay, or single-cell gel electrophoresis (SCGE), is a sensitive, rapid, relatively simple and inexpensive method for detecting DNA strand breaks in individual cells. It is used in a broad variety of applications and as a tool to investigate DNA damage and repair. The sensitivity and specificity of the assay are greatly enhanced if the DNA incubated with an enzyme, whichrecognizes a specific kind of DNA damage. This damage induced by oxidative stress plays a pivotal role in many diseases and in aging. This article is a critical review of the possible application of the comet assay in some pathological states in clinical practice. Most of the studies relate to evaluating the response of an organism to chemotherapy or radiotherapy with statistically significant evidence of DNA damage in patients. Other useful applications have been demonstrated for patients with heart or neurodegenerative diseases. Only a few studies have been published on the use of this method in critically ill patients, although its use would be appropriate. There are also other scenarios where the comet assay could prove to be very useful in the future, such as in predicting the likelihood of certain pathological conditions.

Oxidative stress, caloric intake and outcomes of critically ill patients

BACKGROUND

The aim of this study was to investigate the patterns of oxidative stress in critically ill patients and the association with caloric intake and outcomes.

METHODS

In this pre-planned sub-study of the PermiT (Permissive Underfeeding versus Target Enteral Feeding in Adult Critically Ill Patients Trial- ISRCTN68144998), we included patients expected to stay in the ICU for ≥14 days. Serum samples were collected on days 1, 3, 5, 7 and 14 of enrollment. We measured total anti-oxidant capacity (TAC), protein carbonyl concentration (a measure of protein oxidation) and 8-hydroxy-7,8-dihydro-2'-deoxyguanosine (8-OHdG) (a measure of DNA oxidation). We used principal component analysis (PCA) and hierarchical cluster analysis (HCA) to group patients according to oxidative stress.

RESULTS

Principal component analysis identified 2 components that were responsible for 79% of the total variance, and cluster analysis grouped patients in three statistically distinct clusters. Majority of patients 78.6% (44/55) were included in cluster 1 with lowest TAC, protein carbonyl and 8-OHdG levels and cluster 2 which accounted for 16.1% (9/55) of patients had the highest levels of TAC and intermediate levels of protein carbonyl levels. Cluster 3 patients 5.4% (3/56) had the highest protein carbonyl levels. Incident renal replacement therapy was highest in cluster 2 (4/8, 50.0%), compared to cluster 1 (4/42, 9.5%) and cluster 3 (1/3, 33.3%, p 0.01). When adjusted to oxidative stress cluster membership, permissive underfeeding was not associated with 90-day mortality (adjusted odds ratio, aOR 1.37, 95% CI 0.36, 5.25, p 0.64) but was associated significantly with lower incident renal replacement therapy (aOR 0.02, 95% CI < 0.001, 0.57, p 0.02).

CONCLUSIONS

There are different distinct patterns of oxidative stress in critically ill patients. Incident renal replacement therapy was different among the three clusters. Our data suggest a protective effect of permissive underfeeding on incident renal replacement therapy that may differ by clusters of oxidative stress.

Location-dependent effects of trauma on oxidative stress in humans

Though circulating antioxidant capacity in plasma is homeostatically regulated, it is not known whether acute stressors (i.e. trauma) affecting different anatomical locations could have quantitatively different impacts. For this reason, we evaluated the relationship between the anatomical location of trauma and plasma total antioxidant capacity (TAC) in a prospective study, where the anatomical locations of trauma in polytraumatic patients (n = 66) were categorized as primary affecting the brain -traumatic brain injury (TBI)-, thorax, abdomen and pelvis or extremities. We measured the following: plasma TAC by 2 independent methods, the contribution of selected antioxidant molecules (uric acid, bilirubin and albumin) to these values and changes after 1 week of progression. Surprisingly, TBI lowered TAC (919 ± 335 μM Trolox equivalents (TE)) in comparison with other groups (thoracic trauma 1187 ± 270 μM TE; extremities 1025 ± 276 μM TE; p = 0.004). The latter 2 presented higher hypoxia (PaO₂/FiO₂ 272 ± 87 mmHg) and hemodynamic instability (inotrope use required in 54.5%) as well. Temporal changes in TAC are also dependent on anatomical location, as thoracic and extremity trauma patients’ TAC values decreased (1187 ± 270 to 1045 ± 263 μM TE; 1025 ± 276 to 918 ± 331 μM TE) after 1 week (p < 0.01), while in TBI these values increased (919 ± 335 to 961 ± 465 μM TE). Our results show that the response of plasma antioxidant capacity in trauma patients is strongly dependent on time after trauma and location, with TBI failing to induce such a response.

Vitamin C to Improve Organ Dysfunction in Cardiac Surgery Patients-Review and Pragmatic Approach

The pleiotropic biochemical and antioxidant functions of vitamin C have sparked recent interest in its application in intensive care. Vitamin C protects important organ systems (cardiovascular, neurologic and renal systems) during inflammation and oxidative stress. It also influences coagulation and inflammation; its application might prevent organ damage. The current evidence of vitamin C's effect on pathophysiological reactions during various acute stress events (such as sepsis, shock, trauma, burn and ischemia-reperfusion injury) questions whether the application of vitamin C might be especially beneficial for cardiac surgery patients who are routinely exposed to ischemia/reperfusion and subsequent inflammation, systematically affecting different organ systems. This review covers current knowledge about the role of vitamin C in cardiac surgery patients with focus on its influence on organ dysfunctions. The relationships between vitamin C and clinical health outcomes are reviewed with special emphasis on its application in cardiac surgery. Additionally, this review pragmatically discusses evidence on the administration of vitamin C in every day clinical practice, tackling the issues of safety, monitoring, dosage, and appropriate application strategy.

The tri-peptide GHK-Cu complex ameliorates lipopolysaccharide-induced acute lung injury in mice

The tripeptide-copper complex glycyl-l-histidyl-l-lysine-Cu (II) (GHK-Cu) is involved in wound healing and tissue remodeling. Although GHK-Cu exhibits anti-aging and tissue renewing properties, its roles in acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) are still unknown. Therefore, we examined the effects of GHK-Cu in lipopolysaccharide (LPS)-induced RAW 264.7 macrophages in vitro and ALI in mice in vivo. GHK-Cu treatment reduced reactive oxygen species (ROS) production, increased superoxide dismutase (SOD) activity while decreased TNF-α and IL-6 production through the suppression of NF-κB p65 and p38 MAPK signaling in vitro and in vivo model of ALI. Moreover, GHK-Cu attenuated LPS-induced lung histological alterations, suppressed the infiltration of inflammatory cells into the lung parenchyma in LPS-induced ALI in mice. Taken together, these findings demonstrate that GHK-Cu possesses a protective effect in LPS-induced ALI by inhibiting excessive inflammatory responses; accordingly it may represent a novel therapeutic approach for ALI/ARDS.

Prognostic value of HMGB1 and oxidative stress markers in multiple trauma patients: A single-centre prospective study

Serious multiple traumatic injuries may rapidly become fatal or be complicated by a life-threatening sequelae leading to a significant increase of the mortality rate. Trauma scoring systems are used to evaluate the critical status of the patient and recently many different biomarkers have been taken into account to better estimate the potential clinical outcome. The aim of the present study is to analyse the expression pattern of high-mobility group box-1 (HMGB1), oxidative stress markers and nuclear factor erythroid 2-related (Nrf2) in critically ill traumatic patients (at hospital admittance and after 6 and 24 h), in order to find out their potential role as early post-traumatic predictors markers. Forty-seven patients admitted for multiple trauma and 15 healthy participants were prospectively recruited. Eight patients (17%) died within 92 h of admission; this subgroup of patients presented the highest severity scores and their HMGB1 expression levels were significantly correlated with ISS, whereas patients with higher ISS exhibited higher levels of HMGB1 (P <0.001). Our study suggests the role of HMGB1 as a predictive biomarker of outcome in injured patients and hypothesizes the protective role of Nrf2 in bringing down the oxidative stress and HMGB1 release; measuring HMGB1 in combination with Nrf2 might represent a potentially useful tool in the early detection of post-trauma complications.

A pilot clinical trial of the effects of coenzyme Q10 on chronic tinnitus aurium

OBJECTIVE: To determine the short-term effects of coenzyme Q10 (CoQ10) on the antioxidative status and tinnitus expression in patients with chronic tinnitus aurium.

STUDY DESIGN: A 16-week prospective nonrandomized clinical trial (n = 20). Tinnitus and Short Form-36 Questionnaires (TQ/SF-36) were evaluated together with the plasma concentrations of CoQ10, malondialdehyde, and the total antioxidant status.

RESULTS: The mean plasma CoQ10 concentration rose under external CoQ10 supply and remained elevated after medication stopped without overall effects on the tinnitus score. However, in a subgroup of 7 patients with low initial plasma CoQ10 concentration and significant increase in the plasma CoQ10 level, a clear decrease in the TQ score was observed.

CONCLUSION: In patients with a low plasma CoQ10 concentration, CoQ10 supply may decrease the tinnitus expression.

SIGNIFICANCE: This is the first study to examine the effect of CoQ10 in chronic tinnitus aurium.

© 2007 American Academy of Otolaryngology-Head and Neck Surgery Foundation. All rights reserved.

Xenon triggers pro-inflammatory effects and suppresses the anti-inflammatory response compared to sevoflurane in patients undergoing cardiac surgery

Introduction

Cardiac surgery encompasses various stimuli that trigger pro-inflammatory mediators, reactive oxygen species and mobilization of leucocytes. The aim of this study was to evaluate the effect of xenon on the inflammatory response during cardiac surgery.

Methods

This randomized trial enrolled 30 patients who underwent elective on-pump coronary-artery bypass grafting in balanced anaesthesia of either xenon or sevoflurane. For this secondary analysis, blood samples were drawn prior to the operation, intra-operatively and on the first post-operative day to measure the pro- and anti-inflammatory cytokines interleukin-6 (IL-6), interleukin-8/C-X-C motif ligand 8 (IL-8/CXCL8), and interleukin-10 (IL-10). Chemokines such as C-X-C motif ligand 12/ stromal cell-derived factor-1α (CXCL12/SDF-1α) and macrophage migration inhibitory factor (MIF) were measured to characterize xenon’s perioperative inflammatory profile and its impact on migration of peripheral blood mononuclear cells (PBMC).

Results

Xenon enhanced the postoperative increase of IL-6 compared to sevoflurane (Xenon: 90.7 versus sevoflurane: 33.7 pg/ml; p = 0.035) and attenuated the increase of IL-10 (Xenon: 127.9 versus sevoflurane: 548.3 pg/ml; p = 0.028). Both groups demonstrated a comparable intraoperative increase of oxidative stress (intra-OP: p = 0.29; post-OP: p = 0.65). While both groups showed an intraoperative increase of the cardioprotective mediators MIF and CXCL12/SDF-1α, only MIF levels decreased in the xenon group on the first postoperative day (50.0 ng/ml compared to 23.3 ng/ml; p = 0.012), whereas it remained elevated after sevoflurane anaesthesia (58.3 ng/ml to 53.6 ng/ml). Effects of patients’ serum on chemotactic migration of peripheral mononuclear blood cells taken from healthy volunteers indicated a tendency towards enhanced migration after sevoflurane anaesthesia (p = 0.07).

Conclusions

Compared to sevoflurane, balanced xenon anaesthesia triggers pro-inflammatory effects and suppresses the anti-inflammatory response in cardiac surgery patients even though the clinical significance remains unknown.

Trial registration

This clinical trial was approved by the European Medicines Agency (EudraCT-number: 2010-023942-63) and at ClinicalTrials.gov (NCT01285271; first received: January 24, 2011).

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-015-1082-7) contains supplementary material, which is available to authorized users.

Exogenous Carbon Monoxide Decreases Sepsis-Induced Acute Kidney Injury and Inhibits NLRP3 Inflammasome Activation in Rats

Carbon monoxide (CO) has shown various physiological effects including anti-inflammatory activity in several diseases, whereas the therapeutic efficacy of CO on sepsis-induced acute kidney injury (AKI) has not been reported as of yet. The purpose of the present study was to explore the effects of exogenous CO on sepsis-induced AKI and nucleotide-binding domain-like receptor protein 3 (NLRP3) inflammasome activation in rats. Male rats were subjected to cecal ligation and puncture (CLP) to induce sepsis and AKI. Exogenous CO delivered from CO-releasing molecule 2 (CORM-2) was used intraperitoneally as intervention after CLP surgery. Therapeutic effects of CORM-2 on sepsis-induced AKI were assessed by measuring serum creatinine (Scr) and blood urea nitrogen (BUN), kidney histology scores, apoptotic cell scores, oxidative stress, levels of cytokines TNF-α and IL-1β, and NLRP3 inflammasome expression. CORM-2 treatment protected against the sepsis-induced AKI as evidenced by reducing serum Scr/BUN levels, apoptotic cells scores, increasing survival rates, and decreasing renal histology scores. Furthermore, treatment with CORM-2 significantly reduced TNF-α and IL-1β levels and oxidative stress. Moreover, CORM-2 treatment significantly decreased NLRP3 inflammasome protein expressions. Our study provided evidence that CORM-2 treatment protected against sepsis-induced AKI and inhibited NLRP3 inflammasome activation, and suggested that CORM-2 could be a potential therapeutic candidate for treating sepsis-induced AKI.

Hypoxia inhibits semicarbazide-sensitive amine oxidase activity in adipocytes

Semicarbazide-sensitive amine oxidase (SSAO), an enzyme highly expressed on adipocyte plasma membranes, converts primary amines into aldehydes, ammonium and hydrogen peroxide, and is likely involved in endothelial damage during the course of diabetes and obesity. We investigated whether in vitro, adipocyte SSAO was modulated under hypoxic conditions that is present in adipose tissue from obese or intensive care unit. Physical or pharmacological hypoxia decreased SSAO activity in murine adipocytes and human adipose tissue explants, while enzyme expression was preserved. This effect was time-, dose-dependent and reversible. This down-regulation was confirmed in vivo in subcutaneous adipose tissue from a rat model of hypoxia. Hypoxia-induced suppression in SSAO activity was independent of the HIF-1-α pathway or of oxidative stress, but was partially antagonized by medium acidification. Hypoxia-induced down-regulation of SSAO activity could represent an adaptive mechanism to lower toxic molecules production, and may thus protect from tissue injury during these harmful conditions.

Anti-inflammatory effects of Reduning Injection on lipopolysaccharide-induced acute lung injury of rats

Objective

To evaluate the protective effects of Reduning Injection (热毒宁注射液, RDN), a patent Chinese medicine, on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in rats and its underlying mechanisms of action.

Methods

Sixty male Sprague-Dawley rats were randomly divided into 6 groups, including normal control, model, dexamethasone (DEX, 5 mg/kg), RDN-H (720 mg/kg), RDN-M (360 mg/kg) and RDN-L (180 mg/kg) groups, with 10 rats in each group. Rats were challenged with intravenous injection of LPS 1 h after intraperitoneal treatment with RDN or DEX. At 6 h after LPS challenge, lung tissues and bronchoalveolar lavage fluid (BALF) were collected, and the number of inflammatory cells was determined. The right lungs were collected for histopathologic examination, measurement of gene and protein expressions, superoxide dismutase (SOD) and myeloperoxidase (MPO) activities.

Results

In vivo pretreatment of RDN (360, 720 mg/kg) significantly reduced the weight of wet to dry (W/D) ratio of lung, protein content in BALF, and led to remarkable attenuation of LPS-induced histopathological changes in the lungs. Meanwhile, RDN enormously decreased BALF total inflammatory cells, especially neutrophil and macrophage cell numbers. Moreover, RDN increased SOD activity, inhibited MPO activity, alleviated LPS-induced tumor neurosis factor-α (TNF-α) and inducible nitric oxide synthase (iNOS) expression in lung tissues. Furthermore, RDN (720 mg/kg) efficiently weakened nuclear factorkappa B (NF-κB) gene and protein expression.

Conclusion

Anti-inflammatory effects of RDN was demonstrated to be preventing pulmonary neutrophil infiltration, lowering MPO activity, TNF-α and iNOS gene expression by inhibiting NF-κB activity in LPS-induced ALI.

Oxidative stress status in patients with acute urticaria

BACKGROUND

The conflicting information related to oxidative stress status in patients with chronic idiopathic urticaria has been reported in several studies. However, the association between acute urticaria (AU) and oxidative stress has not been investigated exhaustively.

OBJECTIVES

To evaluate the role of the oxidative stress in the patients with AU by determining the oxidant/antioxidant activity in AU and to establish its clinical significance.

METHODS

About 50 patients with AU, (10 males, 40 females) and 30 unrelated healthy controls (4 males, 26 females) were enrolled into the study. The activity of the antioxidant enzymes copper-zinc superoxide dismutase (Cu-Zn-SOD), glutathione peroxidase (GSH-Px) and catalase, and the levels of malondialdehyde (MDA), serum NO and protein carbonyls levels in the plasma were measured spectrophotometrically at samples.

RESULTS

A statistically significant increase was observed in serum Cu-ZnSOD activities of the patients when compared with that of the controls (p < 0.001), while a statistically significant decrease was observed in GSH-Px activities of the patients according to the controls (p = 0.002). Serum MDA and NO levels were significantly higher in patients with AU when compared with control group (p < 0.001 for both of them). The levels of protein carbonyls were significantly lower in patients with AU when compared with control group (p < 0.001).

CONCLUSION

It seems there is an oxidative burden in the patients with AU. Cutaneous oxidative stress may play a role in pathogenesis of the disease.

Immunonutrition improves functional capacities in head and neck and esophageal cancer patients undergoing radiochemotherapy: a randomized clinical trial

BACKGROUND & AIMS

Malnutrition is frequent in head and neck (HN) and esophageal cancer patients and aggravated by radiochemotherapy (RCT), increasing morbi-mortality and treatment toxicity. Our goal was to investigate the effect of immunonutrition consisting of an arginine, omega-3 fatty acid, nucleotides-enriched diet on nutritional status, and functional capacity in HN or esophageal cancer patients undergoing RCT.

METHODS

37 patients were randomized in a double-blind clinical trial. 5 days before and until the end of RCT (5-7 weeks), they received either an Immunomodulating Enteral Nutrition (IEN) or an isonitrogenous, isoenergetic Standard Enteral Nutrition (SEN). Anthropometrical parameters, nutritional risk index (NRI), serum albumin, plasma antioxidant capacity, and functional capacity were recorded between the beginning and the end of RCT.

RESULTS

A significant gain in total body weight (+2.1 ± 3.1 kg) was observed in IEN patients. Albuminemia and NRI were improved concomitantly in IEN malnourished patients. Plasma antioxidant capacity was improved (+100 ± 13 μM EqTrolox) in IEN patients. Functional capacity measured by WHO Performance Status and Karnofsky index was maintained in IEN patients but significantly reduced in SEN patients.

CONCLUSIONS

These preliminary data show that immunonutrition could improve the nutritional status together with functional capacity in HN and esophageal cancer patients undergoing RCT.

CLINICAL TRIAL REGISTRATION

This clinical trial promoted by the University Hospital Center of Clermont-Ferrand has been registered at ClinicalTrial.gov website under the following reference: NCT00333099.

Oxidative status in ICU patients with septic shock

The aim of this pilot study was to investigate variability of oxidative stress during sepsis evolution. ICU patients with the diagnosis of septic shock were included. Thiobarbituric-acid reactive substances, total antioxidant capacity, protein carbonyls in plasma, reduced, oxidized glutathione and catalase activity in erythrocyte lysate were assessed in the 1st, 3rd, 5th and 8th day after sepsis appearance. A total of 17 patients were divided in two groups: survivors (n=7) and non-survivors (n=10). APACHE II was 11.5 ± 5.4 and 19.9 ± 4.97 in survivors and non-survivors respectively (p=0.005), while mean age and SOFA score at sepsis diagnosis, were similar between the two groups. GSH levels, catalase activity and protein carbonyls presented significant different course in time between survivors and non-survivors (p<0.05). Catalase activity was significantly higher in survivors (238.8 ± 51.5) than non-survivors (166.4 ± 40.2; p=0.005), while protein carbonyls levels were significantly lower in survivors (0.32 ± 0.09) than non-survivors (0.48 ± 0.16; p=0.036) on the 1st day. Yet, non-survivors exhibited a declining course in GSH levels during time, while GSH levels were maintained in survivors. Conclusively, a longstanding antioxidant deficiency in non-surviving patients was noted. This phenomenon was clearly prominent in patients' erythrocytes.

Effect of N-acetylcysteine supplementation on intracellular glutathione, urine isoprostanes, clinical score, and survival in hospitalized ill dogs

BACKGROUND

Antioxidant depletion and lipid peroxidation have been correlated with disease severity and associated with poor outcomes.

HYPOTHESIS/OBJECTIVES

Supplementing dogs with N-acetylcysteine (NAC) during the first 48 hours of hospitalization will increase cysteine, normalize glutathione concentrations, and decrease the degree of lipid peroxidation associated with illness.

ANIMALS

Sixty systemically ill hospitalized client-owned dogs and 14 healthy control dogs.

METHODS

Randomized investigator-blinded, placebo-controlled prospective study. Dogs were randomized to treatment with NAC (n = 30) versus placebo (n = 30). Antioxidants, urine 8-isoprostane/creatinine (IP/Cr), and clinical score were determined before and after treatment with NAC. Glutathione, cysteine, and vitamin E concentrations were quantified using high-performance liquid chromatography. Atomic absorption spectroscopy and enzyme-linked immunosorbent assays were used to quantify selenium and isoprostane concentrations, respectively.

RESULTS

Ill dogs had significantly lower vitamin E concentrations (27 versus 55 μg/mL; P = .0005) as well as elevated IP/Cr ratios (872 versus 399 pg/mg; P = .0007) versus healthy dogs. NAC supplementation significantly increased plasma cysteine (8.67 versus 15.1 μM; P < .0001) while maintaining glutathione concentrations. Dogs in the placebo group experienced a statistically significant decrease in glutathione concentrations (1.49 versus 1.44 mM; P = .0463). Illness severity and survival were unchanged after short duration NAC supplementation.

CONCLUSIONS

Ill dogs experience systemic oxidative stress. Supplementation with NAC during the first 48 hours of hospitalization stabilized erythrocyte glutathione concentrations. The clinical impact of this supplementation and glutathione concentration stabilization was undetermined.

Altered activities of antioxidant enzymes in patients with metabolic syndrome

OBJECTIVE

In the pathogenesis of the metabolic syndrome (MetS), an increase of oxidative stress could play an important role which is closely linked with insulin resistance, endothelial dysfunction, and chronic inflammation. The aim of our study was to assess several parameters of the antioxidant status in MetS.

METHODS

40 subjects with MetS and 40 age- and sex-matched volunteers without MetS were examined for activities of superoxide dismutase (CuZnSOD), catalase (CAT), glutathione peroxidase 1 (GPX1), glutathione reductase (GR), paraoxonase1 (PON1), concentrations of reduced glutathione (GSH), and conjugated dienes in low-density lipoprotein (CD-LDL).

RESULTS

Subjects with MetS had higher activities of CuZnSOD (p < 0.05) and GR (p < 0.001), higher concentrations of CD-LDL (p < 0.001), lower activities of CAT (p < 0.05) and PON1 (p < 0.05), and lower concentrations of GSH (p < 0.05), as compared with controls. Activity of GPX1 was not significantly changed.

CONCLUSIONS

Our results implicated an increased oxidative stress in MetS and a decreased antioxidative defense that correlated with some laboratory (triglycerides, high-density lipoprotein cholesterol (HDL-C)) and clinical (waist circumference, blood pressure) components of MetS.

Licochalcone a inhibits lipopolysaccharide-induced inflammatory response in vitro and in vivo

Licochalcone A (Lico A), a flavonoid found in licorice root (Glycyrrhiza glabra), is known for its antimicrobial activity and its reported ability to inhibit cancer cell proliferation. In the present study, we found that Lico A exerted potent anti-inflammatory effects in in vitro and in vivo models induced by lipopolysaccharide (LPS). The concentrations of TNF-α, interleukin (IL)-6, and IL-1β in the culture supernatants of RAW 264.7 cells were determined at different time points following LPS administration. LPS (0.5 mg/kg) was instilled intranasally (i.n.) in phosphate-buffered saline to induce acute lung injury, and 24 h after LPS was given, bronchoalveolar lavage fluid was obtained to measure pro-inflammatory mediator and total cell counts. The phosphorylation of mitogen-activated protein kinases (MAPKs) and nuclear factor-κB (NF-κB) p65 protein was analyzed by Western blotting. Our results showed that Lico A significantly reduced the amount of inflammatory cells, the lung wet-to-dry weight (W/D) ratio, protein leakage, and myeloperoxidase activity and enhances oxidase dimutase activity in mice with LPS-induced acute lung injury (ALI). Enzyme-linked immunosorbent assay results indicated that Lico A can significantly down-regulate TNF-α, IL-6, and IL-1β levels in vitro and in vivo, and treatment with Lico A significantly attenuated alveolar wall thickening, alveolar hemorrhage, interstitial edema, and inflammatory cells infiltration in mice with ALI. In addition, we further demonstrated that Lico A exerts an anti-inflammation effect in an in vivo model of acute lung injury through suppression of NF-κB activation and p38/ERK MAPK signaling in a dose-dependent manner.

Role of Oxidative Stress in the Clinical Outcome of Patients with Multiple Blunt Trauma

OBJECTIVE: This prospective study evaluated serum total oxidant status (TOS), total antioxidant status (TAS) and oxidative stress index (OSI), along with the Revised Trauma Score (RTS) and Injury Severity Score (ISS), as predictors of clinical outcome in the early post-traumatic period in patients with multiple blunt trauma (MBT). METHODS: The study included 52 patients admitted to the emergency department with MBT and 40 age-and sex-matched healthy control subjects. RESULTS: The overall MBT patient mortality was 32.7% (17/52). There was no significant association between age and mortality in MBT patients, but there was a negative correlation between mortality and RTS, and a positive correlation between mortality and ISS. TOS levels were significantly higher in nonsurvivors compared with survivors. There was no correlation between TAS or OSI and survival. ISS and RTS showed positive and negative correlations with TOS level, respectively, but neither was significantly related to TAS or OSI. CONCLUSIONS: These findings suggest that TOS, as an early oxidative stress biomarker, may be an objective alternative criterion to the ISS and RTS for managing patients with MBT during the early period following traumatic injury.

Burn and smoke injury activates poly(ADP-ribose)polymerase in circulating leukocytes

The nuclear enzyme poly(ADP-ribose)polymerase (PARP) plays a significant role in the pathogenesis of various forms of critical illness. DNA strand breaks induced by oxidative and nitrative stress trigger the activation of PARP, and PARP, in turn, mediates cell death and promotes proinflammatory responses. Until recently, most studies focused on the role of PARP in solid organs such as heart, liver, and kidney. We investigated the effect of burn and smoke inhalation on the levels of poly(ADP-ribosylated) proteins in circulating sheep leukocytes ex vivo. Adult female merino sheep were subjected to burn injury (2× 20% each flank, 3 degrees) and smoke inhalation injury (insufflated with a total of 48 breaths of cotton smoke) under deep anesthesia. Arterial and venous blood was collected at baseline, immediately after the injury and 1 to 24 h after the injury. Leukocytes were isolated with the Histopaque method. The levels of poly(ADP-ribosyl)ated proteins were determined by Western blotting. The amount of reactive oxygen species was quantified by the OxyBlot method. To examine whether PARP activation continues to increase ex vivo in the leukocytes, blood samples were incubated at room temperature or at 37°C for 3 h with or without the PARP inhibitor PJ34. To investigate whether the plasma of burn/smoke animals may trigger PARP activation, burn/smoke plasma was incubated with control leukocytes in vitro. The results show that burn and smoke injury induced a marked PARP activation in circulating leukocytes. The activity was the highest immediately after injury and at 1 h and decreased gradually over time. Incubation of whole blood at 37°C for 3 h significantly increased poly(ADP-ribose) levels, indicative of the presence of an ongoing cell activation process. In conclusion, PARP activity is elevated in leukocytes after burn and smoke inhalation injury, and the response parallels the time course of reactive oxygen species generation in these cells.

Cell death in the maintenance and abrogation of tolerance: the five Ws of dying cells

The mammalian immune system continually faces death in the form of its own dead and dying cells that arise during normal tissue turnover, infections, cellular damage, and cancer. Complex decisions must then be made that will permit a protective response to pathogens, while at the same time destroying tumors but not attacking vital systems of the host that could lead to autoimmunity. By using an investigative technique termed the five Ws (who, what, when, where, and why), we will examine how the immune system responds to antigens generated via cell death. This analysis will give us a better understanding of the molecular differences fundamental to tolerogenic or immunogenic cell death, the cells that sense and react to the dead cells, and the consequences of these fundamental elements on the maintenance or abrogation of tolerance.

Antioxidant therapy in acute pancreatitis: experimental and clinical evidence

SIGNIFICANCE

Oxidative stress plays an important role in the pathogenesis of both acute and chronic pancreatitis. Although its impact is well investigated and has been studied clinically in chronic pancreatitis, it is less well defined for acute pancreatitis.

RECENT ADVANCES

Pathophysiological aspects of oxidative stress in acute pancreatitis have shown that reactive oxidative species (ROS) participate in the inflammatory cascade, and mediate inflammatory cell adhesion and consecutive tissue damage. Furthermore, ROS are involved in the generation of pain as another important clinical feature of patients suffering from acute pancreatitis.

CRITICAL ISSUES

Despite sufficient basic and experimental knowledge and evidence, the step from bench to bedside has not been successfully performed. Only a limited number of clinical studies are available that can give convincing evidence for the use of antioxidants in the clinical setting of acute pancreatitis.

FUTURE DIRECTIONS

Future studies are required to evaluate potential benefits of antioxidative substances to attenuate the severity of acute pancreatitis. Special focus should be put on the aspect of pain generation and the progression from mild to severe acute pancreatitis in the clinical setting.

Oxidative Stress in Critically Ill Children with Sepsis

Sepsis is one of the leading causes of death in critically ill patients in the intensive care unit. Sepsis accounts for significant morbidity and mortality in critically ill children as well. The pathophysiology of sepsis is characterized by a complex systemic inflammatory response, endothelial dysfunction, and alterations in the coagulation system, which lead to perturbations in the delivery of oxygen and metabolic substrates to the tissues, end-organ dysfunction, and ultimately death. Oxidative stress plays a crucial role as both a promoter and mediator of the systemic inflammatory response, suggesting potential targets for the treatment of critically ill children with the sepsis syndrome. Herein, we will provide a brief review of the role of oxidative and nitrosative stress in the pathophysiology of sepsis.

Determination of the antioxidative capacity of the skin in vivo using resonance Raman and electron paramagnetic resonance spectroscopy

BACKGROUND

Non-invasive measurements are of major interest for investigating the effects of stress, nutrition, diseases or pharmaceuticals on the antioxidative capacity of the human skin. However, only a few non-invasive methods are available.

MATERIAL AND METHODS

The resonance Raman spectroscopy is well established to monitor carotenoids in the skin, but correlations with other antioxidants have not yet been described. Electron paramagnetic resonance spectroscopy used for measurements of free radicals has already been used elsewhere to investigate the reduction of applied long-living nitroxide radicals, caused by skin antioxidants and UV irradiation, but only a single or up to four volunteers were included in these studies. Therefore, in this study, the two methods were applied in parallel on 17 volunteers, and the rate constant of the nitroxide decrease was correlated with the cutaneous carotenoid concentration.

RESULTS AND DISCUSSION

A correlation with R = 0.65 was found, supporting the thesis that different antioxidants protect each other and build an antioxidative network in the skin. The results also give first indications that the carotenoids serve as marker substances for the antioxidative capacity, if the nutrition is well balanced.

The effects of aging on pulmonary oxidative damage, protein nitration, and extracellular superoxide dismutase down-regulation during systemic inflammation

Systemic inflammatory response syndrome (SIRS), a serious clinical condition characterized by whole-body inflammation, is particularly threatening for elderly patients, who suffer much higher mortality rates than the young. A major pathological consequence of SIRS is acute lung injury caused by neutrophil-mediated oxidative damage. Previously, we reported an increase in protein tyrosine nitration (a marker of oxidative/nitrosative damage) and a decrease in the antioxidant enzyme extracellular superoxide dismutase (EC-SOD) in the lungs of young mice during endotoxemia-induced SIRS. Here we demonstrate that during endotoxemia, down-regulation of EC-SOD is significantly more profound and prolonged, whereas up-regulation of iNOS is augmented, in aged compared to young mice. Aged mice also showed 2.5-fold higher protein nitration levels, compared to young mice, with particularly strong nitration in the pulmonary vascular endothelium during SIRS. Additionally, by two-dimensional gel electrophoresis, Western blotting, and mass spectrometry, we identified proteins that show increased tyrosine nitration in age- and SIRS-dependent manners; these proteins (profilin-1, transgelin-2, LASP 1, tropomyosin, and myosin) include components of the actin cytoskeleton responsible for maintaining pulmonary vascular permeability. Reduced EC-SOD in combination with increased oxidative/nitrosative damage and altered cytoskeletal protein function due to tyrosine nitration may contribute to augmented lung injury in the aged with SIRS.

The role of advanced oxidation protein products in intensive care unit patients with acute kidney injury

INTRODUCTION

Oxidative stress (OS) is an imbalance between the production of oxidizing chemical species and the antioxidant defense. It is known that OS increases in critically ill patients with acute kidney injury (AKI). Measurement of advanced oxidation protein products (AOPPs) has been found to be a simple tool for monitoring OS.

AIMS

The aims of this study were to evaluate OS in intensive care unit (ICU) patients by AOPP levels and compare its levels between patients with and without AKI; we also wanted to assess the ability of AOPP to predict the development of AKI in this population. PATIENTS, MATERIAL, AND METHODS: We performed a prospective cohort study to compare AOPP levels between critically ill AKI (as defined by Risk-Injury-Failure-Loss-End Stage Renal Disease [RIFLE] criteria) and non-AKI patients. Blood samples were collected from all consecutively admitted patients upon arrival to ICU and daily for up to 4 days. We collected 234 blood samples from 86 adult medical and surgical ICU patients. The levels of AOPP were determined in the plasma and measured by spectrophotometry at 340 nm and compared between non-AKI (n = 71) and AKI patients (n = 15). We further subdivided the AKI patients according to severity of AKI (worst RIFLE class attained in ICU).

RESULTS

Among the 86 patients, 15 (17.44%) developed AKI during their stay in ICU, whereas 71 patients (82.56%) did not. Among the AKI patients, 5 had AKI on ICU admission, whereas 10 developed it later. The levels of AOPP were significantly higher among AKI patients compared with non-AKI patients (153.8 ± 117.8 versus 129.0 ± 114.9 μmol/L, respectively; P = .034). Patients with the most severe AKI (RIFLE class Failure) had markedly elevated AOPP levels compared with RIFLE class Risk and Injury patients (P = .012). Area under the curve of receiver operating characteristic for prediction of AKI within 48 hours after first blood sample collection was 0.5835 (P = not significant).

CONCLUSIONS

This is the first study to explore the relationship between severity of AKI and AOPP. In our adult ICU population, AOPP levels were higher in AKI compared with non-AKI critically ill patients. On the other hand, AOPP levels were not found to be a useful biomarker for AKI, as it was unable to identify patients who developed AKI within 24, 48, 76, and 96 hours.

Preventive effects of valnemulin on lipopolysaccharide-induced acute lung injury in mice

Valnemulin reportedly regulates inflammatory responses in addition to its in vitro antibacterial activity. In this study, we established a mouse model of lipopolysaccharide (LPS)-induced inflammatory lung injury and investigated the effect of valnemulin (100 mg/kg) on acute lung injury (ALI) 8 h after LPS challenge. We prepared bronchoalveolar lavage fluid (BALF) for measuring protein concentrations, cytokine levels, and superoxidase dismutase (SOD) activity, and collected lungs for assaying wet-to-dry weight (W/D) ratios, myeloperoxidase (MPO) activity, cytokine mRNA expression, and histological change. We found that the pre-administration of valnemulin significantly decreases the W/D ratio of lungs, protein concentrations, and the number of total cells, neutrophils, macrophages, and leukomonocytes, and histologic analysis indicates that valnemulin significantly attenuates tissue injury. Furthermore, valnemulin significantly increases LPS-induced SOD activity in BALF and decreases lung MPO activity as well. In addition, valnemulin also inhibits the production of tumor necrosis factor-alpha, interleukin-6, and interleukin-1beta, which is consistent with mRNA expression in lung. The results showed that valnemulin had a protective effect on LPS-induced ALI in mice.

Injury severity and serum amyloid A correlate with plasma oxidation-reduction potential in multi-trauma patients: a retrospective analysis

Background

In critical injury, the occurrence of increased oxidative stress or a reduced antioxidant status has been observed. The purpose of this study was to correlate the degree of oxidative stress, by measuring the oxidation-reduction potential (ORP) of plasma in the critically injured, with injury severity and serum amyloid A (SAA) levels.

Methods

A total of 140 subjects were included in this retrospective study comprising 3 groups: healthy volunteers (N = 21), mild to moderate trauma (ISS < 16, N = 41), and severe trauma (ISS ≥ 16, N = 78). For the trauma groups, plasma was collected on an almost daily basis during the course of hospitalization. ORP analysis was performed using a microelectrode, and ORP maxima were recorded for the trauma groups. SAA, a sensitive marker of inflammation in critical injury, was measured by liquid chromatography/mass spectrometry.

Results

ORP maxima were reached on day 3 (± 0.4 SEM) and day 5 (± 0.5 SEM) for the ISS < 16 and ISS ≥ 16 groups, respectively. ORP maxima were significantly higher in the ISS < 16 (-14.5 mV ± 2.5 SEM) and ISS ≥ 16 groups (-1.1 mV ± 2.3 SEM) compared to controls (-34.2 mV ± 2.6 SEM). Also, ORP maxima were significantly different between the trauma groups. SAA was significantly elevated in the ISS ≥ 16 group on the ORP maxima day compared to controls and the ISS < 16 group.

Conclusion

The results suggest the presence of an oxidative environment in the plasma of the critically injured as measured by ORP. More importantly, ORP can differentiate the degree of oxidative stress based on the severity of the trauma and degree of inflammation.

Regulation of pentraxin-3 by antioxidants

BACKGROUND

Pentraxin-3 (PTX3) may be a useful biomarker in sepsis, but its regulatory mechanisms are still unclear. Oxidative stress is well defined in patients with sepsis and has a role in regulation of inflammatory pathways which may include PTX3. We undertook an in vitro study of the effect of antioxidants on regulation of PTX3 in endothelial cells combined with a prospective observational pilot study of PTX3 in relation to markers of antioxidant capacity and oxidative stress in patients with sepsis.

METHODS

Human endothelial cells were cultured with lipopolysaccharide 2 microg ml(-1), peptidoglycan G 20 microg ml(-1), tumour necrosis factor (TNF) alpha 10 ng ml(-1), interleukin-1 (IL-1) beta 20 ng ml(-1), or killed Candida albicans yeast cells plus either N-acetylcysteine (NAC) 25 mM, trolox 100 mM, or idebenone 1 microM. Plasma samples were obtained from 15 patients with sepsis and 11 healthy volunteers.

RESULTS

PTX3 levels in plasma were higher in patients with sepsis than in healthy people [26 (1-202) ng ml(-1) compared with 6 (1-12) ng ml(-1), P=0.01]. Antioxidant capacity was lower in patients with sepsis than healthy controls [0.99 (0.1-1.7) mM compared with 2.2 (1.3-3.3) mM, P=0.01]. In patients with sepsis, lipid hydroperoxide levels were 3.32 (0.3-10.6) nM and undetectable in controls. We found no relationship between PTX3 and antioxidant capacity or lipid hydroperoxides. Cell expression of PTX3 increased with all inflammatory stimulants but was highest in cells treated with TNFalpha plus IL-1beta. PTX3 concentrations were lower in cells co-treated with antioxidants (all P<0.05), associated with lower nuclear factor kappaB expression for NAC and trolox (P<0.05).

CONCLUSIONS

PTX3 expression is down-regulated in vitro by antioxidants. Plasma levels of PTX3 are elevated in sepsis but seem to be unrelated to markers of oxidant stress or antioxidant capacity.

The effect of storage on the accumulation of oxidative biomarkers in donated packed red blood cells

BACKGROUND

Transfusion-related acute lung injury (TRALI) is a life-threatening condition characterized by oxidative stress. Longer storage times of packed red blood cells (PRBC) and other blood products have been implicated with an increased risk in developing TRALI in transfused patients.

METHODS

A total of 10 units of blood containing PRBC stored in citrate-phosphate-dextrose buffer at 4 degrees C were included in the study. At Bonfils Blood Center (Denver, CO), samples were collected on storage day 1 and day 42. Samples were immediately centrifuged, and the supernatants were collected and stored at -80 degrees C until further analysis. Oxidation-reduction potential and protein oxidation were measured in both the day 1 and day 42 samples.

RESULTS

Oxidation-reduction potential significantly increased (p < 0.05) in the day 42 sample (98.1 mV +/- 21.9 SD) versus the day 1 sample (62.6 mV +/- 21.5 SD). The oxidation of human serum albumin increased by 63.6% during the storage time. Other serum proteins such as apolipoprotein A1 and transthyretin demonstrated similar increases in oxidation. Also, proteins with a cleaved C-terminal amino acid were observed indicating the presence of carboxypeptidase activity, a marker of inflammation.

CONCLUSIONS

The presence of an oxidative environment in transfused PRBC increases with storage time. This could partially explain the increased risk of developing TRALI related to the transfusion of older blood products.

Protective effects of edaravone on rats with severe acute pancreatitis

AIM: To investigate the therapeutic effects and mechanism of edaravone on rats with severe acute pancreatitis (SAP) induced by L-arginine.

METHODS: A total of 60 rats were randomly and equally divided into three groups, namely control group, SAP model group and edaravone treatment group (n = 20). A SAP model was established by injecting intraperitoneally with L-arginine at a dose of 2.5 g/kg twice at an interval of 1 h, and injecting intravenously with edaravone 3 mg/kg, bid × 3 d (edaravone treatment group). The characteristics and volume of ascites, the pathological changes of pancreatic tissue and the serum levels of amylase (AMY), tumor necrosis factor-α (TNF-α), interleukin (IL)-6 and the contents of malonaldehyde (MDA), superoxide dismutase (SOD), glutathione (GSH) in pancreatic tissue of rats and prognosis were compared after 72 h following administration of L-arginine.

RESULTS: Compared with control group, 72 h after administration of L-arginine, SAP model group showed typical histopathological changes of SAP, elevated the volume of ascites (5.16 ± 1.52 vs 0.50 ± 0.10, P < 0.01), and significantly higher serum levels of AMY, TNF-α, IL-6 and content of MDA of pancreatic tissue (8967.5 ± 298.4 vs 720.1 ± 119.7I; 103.98 ± 10.56 vs 41.59 ± 3.79; 548.57 ± 10.45 vs 198.34 ± 2.10; 35.6 ± 3.8 vs 7.9 ± 2.2, all P < 0.01), and lower GSH and SOD in pancreatic tissue (7.2 ± 0.6 vs 17.1 ± 2.1; 7300 ± 1800 vs 28 400 ± 2700, both P < 0.01). Compared with SAP model group, 72 h after administration of L-arginine, significantly alleviated pathological lesions of SAP, decreased volume of ascites (4.05 ± 1.22 vs 53.16 ± 1.52, P < 0.05), lower pathological scores (P < 0.05), lower serum levels of AMY, TNF-α, IL-6 and MDA in pancreatic tissue (7809.5 ± 158.3 vs 8967.5 ± 298.4; 79.80 ± 14.23 vs 103.98 ± 10.56; 467 ± 6.64 vs548.57 ± 10.45; 29.1 ± 2.6 vs 35.6 ± 3.8, all P < 0.05), and higher GSH and SOD in pancreatic tissue were observed in edaravone treatment group (8.7 ± 1.3 vs 7.2 ± 0.6; 114 000 ± 27 000 vs 7300 ± 1800, both P < 0.05).

CONCLUSION: Edaravone can scavenge oxygen-derived free radicals, upgrade the contents of SOD and GSH in pancreatic tissue, decrease the serum levels of proinflammatory cytokines and, ameliorate the pathological lesions of pancreatic tissue in rats, and has a possibility of decreasing death rate.

Antioxidant enriched enteral nutrition and oxidative stress after major gastrointestinal tract surgery

AIM: To investigate the effects of an enteral supple-ment containing antioxidants on circulating levels of antioxidants and indicators of oxidative stress after major gastrointestinal surgery.

METHODS: Twenty-one patients undergoing major upper gastrointestinal tract surgery were randomised in a single centre, open label study on the effect of postoperative enteral nutrition supplemented with antioxidants. The effect on circulating levels of antioxidants and indicators of oxidative stress, such as F2-isoprostane, was studied.

RESULTS: The antioxidant enteral supplement showed no adverse effects and was well tolerated. After surgery a decrease in the circulating levels of antioxidant parameters was observed. Only selenium and glutamine levels were restored to pre-operative values one week after surgery. F2-isoprostane increased in the first three postoperative days only in the antioxidant supplemented group. Lipopolysaccharide binding protein (LBP) levels decreased faster in the antioxidant group after surgery.

CONCLUSION: Despite lower antioxidant levels there was no increase in the circulating markers of oxidative stress on the first day after major abdominal surgery. The rise in F2-isoprostane in patients receiving the antioxidant supplement may be related to the conversion of antioxidants to oxidants which raises questions on antioxidant supplementation. Module AOX restored the postoperative decrease in selenium levels. The rapid decrease in LBP levels in the antioxidant group suggests a possible protective effect on gut wall integrity. Further studies are needed on the role of oxidative stress on outcome and the use of antioxidants in patients undergoing major abdominal surgery.