Plasma levels of glutathione, alpha-tocopherol and lipid peroxides in polytraumatized patients; evidence for a stimulating effect of TNF alpha on glutathione synthesis

Peripheral IL-6 Levels but not Sarcopenia Are Predictive of 1-Year Mortality After Hip Fracture in Older Patients

BACKGROUND

Sarcopenic patients may have an increased risk of poor outcomes after a hip fracture. The objective of this study was to determine whether sarcopenia and a set of biomarkers were potential predictors of 1-year-mortality in older patients after a hip fracture.

METHODS

About 150 patients at least 80 years old were hospitalized for the surgical treatment of a hip fracture. The primary outcome measure was the death in the first year after the hip fracture. Sarcopenia was defined at baseline by having both low muscle mass (bioimpedance analysis) and handgrip and using the updated European Working Group on Sarcopenia in Older People (EWGSOP2) definition of probable sarcopenia. Janssen's (J) and Masanés (M) cutoff points were used to define low muscle mass.

RESULTS

Mortality 1 year after the hip fracture was 11.5%. In univariate analyses, baseline sarcopenia was not associated with mortality, using neither of the muscle mass cutoff points: 5.9% in sarcopenic (J) versus 12.4% in non-sarcopenic participants (p = .694) and 16% in sarcopenic (M) versus 9.6% in non-sarcopenic participants (p = .285). Probable sarcopenia (EWGSOP2) was not associated with mortality. Peripheral levels of IL-6 at baseline were significantly higher in the group of participants who died in the year after the hip fracture (17.14 ± 16.74 vs 11.42 ± 7.99 pg/mL, p = .026). TNF-α peripheral levels had a nonsignificant trend to be higher in participants who died. No other biomarker was associated with mortality.

CONCLUSIONS

Sarcopenia at baseline was not a predictor of 1-year mortality in older patients after a hip fracture. IL-6 was associated with a higher risk of mortality in these patients, regardless of sarcopenia status.

Model of Magnetic Particle Capture Under Physiological Flow Rates for Cytokine Removal During Cardiopulmonary Bypass

OBJECTIVE

The objective of this study is to design a physical model of a magnetic filtration system which can separate magnetic nanoparticle (MNP)-tagged cytokines from fluid at physiologically relevant flow rates employed during cardiopulmonary bypass (CPB) procedures.

METHODS

The Navier-Stokes equations for the pressure driven flow in the chamber and the quasistatic stray magnetic field produced by an array of permanent magnets were solved using finite element analysis in COMSOL Multiphysics for 2D and 3D representations of the flow chamber. Parameters affecting the drag and magnetic forces including flow chamber dimensions, high gradient magnet array configurations, and particle properties, were changed and evaluated for their effect on MNP capture.

RESULTS

Flow chamber dimensions which achieve appropriate flow conditions for CPB were identified, and magnetic force within the chamber decreased with increased chamber height. A magnetic "block" array produced the highest magnetic force within the chamber. Polymeric microparticles loaded with MNPs were shown to have increased particle capture with increased hydrodynamic diameter.

CONCLUSION

The model achieved a predicted efficiency up to 100% capture in a single-pass of fluid flowing at 1.75 L/min.

SIGNIFICANCE

This work is an important step in designing a magnetic flow chamber that can remove the magnetically tagged cytokines under high flow employed during CPB. Cytokines have been shown to stimulate the systemic inflammatory response (SIR) associated with CPB and are an established therapeutic target to mitigate the SIR. In the long term, this work aims to guide researchers in the more accurate design of magnetic separation systems.

Cysteine/Glutathione Deficiency: A Significant and Treatable Corollary of Disease

Glutathione (GSH) deficiency may play a pivotal role in a variety of apparently unrelated clinical conditions and diseases. Orally administered N-acetylcysteine (NAC), which replenishes the cysteine required for GSH synthesis, has been tested in a large number of randomized placebo-controlled trials involving these diseases and conditions. This chapter focused on developing a base of evidence suggesting that NAC administration improves disease by increasing cysteine and/or GSH in a variety of diseases, thereby implying a significant role for GSH deficiency in the clinical basis of many diseases. To develop this base of evidence, we systematically selected studies which considered the hypothesis that the therapeutic efficacy for NAC is an indication that cysteine and/or GSH deficiency is a pathophysiological part of the diseases studied. In this manner we focus this chapter on explaining the biological mechanisms of NAC therapy in a wide variety of disorders and demonstrate its ubiquitous role in improving disease that involves disrupted GSH and/or cysteine metabolism.

Predictors of recovery in moderate to severe traumatic brain injury

OBJECTIVE

Traumatic brain injury (TBI) is a significant cause of morbidity and mortality worldwide. Clinical outcomes in TBI are determined by the severity of injury, which is dependent on the primary and secondary brain injury processes. Whereas primary brain injury lesions are related to the site of impact, secondary brain injury results from physiological changes caused by oxidative stress and inflammatory responses that occur after the primary insult. The aim of this study was to identify important clinical and biomarker profiles that were predictive of recovery after moderate to severe TBI. A good functional outcome was defined as a Glasgow Outcome Scale (GOS) score of ≥ 4.

METHODS

This was a prospective study of patients with moderate to severe TBI managed at the Nelson Mandela Academic Hospital during the period between March 2014 and March 2016. Following admission and initial management, the patient demographic data (sex, age) and admission Glasgow Coma Scale score were recorded. Oxidative stress and inflammatory biomarkers in blood and CSF were sampled on days 1-7. On day 14, only blood was sampled for the same biomarkers. The primary outcome was the GOS score-due to its simplicity, the GOS was used to assess clinical outcomes at day 90. Because of difficulty in performing regular follow-up due to the vastness of the region, difficult terrain, and long travel distances, a 3-month follow-up period was used to avoid default.

RESULTS

Sixty-four patients with Glasgow Coma Scale scores of ≤ 12 were seen and managed. Among the 56 patients who survived, 42 showed significant recovery (GOS score ≥ 4) at 3 months. Important predictors of recovery included antioxidant activity in the CSF (superoxide dismutase and total antioxidant capacity).

CONCLUSIONS

Recovery after TBI was dependent on the resolution of oxidative stress imbalance.

Glutamine and glutathione at ICU admission in relation to outcome

Glutamine depletion is demonstrated to be an independent predictor of hospital mortality in ICU (intensive care unit) patients. Today glutamine supplementation is recommended to ICU patients on parenteral nutrition. In addition to glutamine, glutathione may be a limiting factor in ICU patients with MOF (multiple organ failure). To study the prevalence of glutamine and glutathione depletion an observational study was performed. The results were analysed in relation to mortality and the conventional predictors of mortality outcome, APACHE II (Acute Physiology and Chronic Health Evaluation II) and SOFA (Sequential Organ Failure Assessment). Consecutive patients admitted to the ICU at Karolinska University Hospital Huddinge were studied. Patient admission scoring of APACHE II and SOFA were registered as well as mortality up to 6 months. Plasma glutamine concentration and whole blood glutathione status at admittance were analysed. The admission plasma glutamine concentrations were totally independent of the conventional risk scoring at admittance, and a subnormal concentration was an independent predictor of mortality. In addition, glutathione redox status was also an independent mortality predictor, but here a normal ratio was the risk factor. In both cases the mortality risk was mainly confined to the post-ICU period. A low plasma concentration of glutamine at ICU admission is an independent risk factor for post-ICU mortality. The possible benefit of extending glutamine supplementation post-ICU should be evaluated prospectively.

Pivotal role of glutathione depletion in plasma-induced endothelial oxidative stress during sepsis

OBJECTIVE

Plasma from septic shock patients can induce production of reactive oxygen species (ROS) by human umbilical vein endothelial cells (HUVEC) in vitro. How endothelial cells defend themselves against ROS under increased oxidative stress has not yet been examined. This study investigates the antioxidant defenses of HUVEC exposed to plasma obtained from either septic shock patients or healthy volunteers.

DESIGN

Prospective, observational study.

SETTING

Medical intensive care unit in a university hospital.

PATIENTS

Twenty-five patients with septic shock and 10 healthy volunteers.

INTERVENTIONS

Blood samples were collected within the first 24 hrs of septic shock. In vitro HUVEC production of ROS was studied by spectrofluorimetry using 2',7'-dichlorodihydrofluorescein diacetate fluorescent dye. Reactive nitrogen species were also assessed. Intracellular reduced glutathione (GSH) levels were measured using monochlorobimane fluorescent dye. Activity of catalase and superoxide dismutase in HUVEC were also measured. Cell death was assessed using YOPRO fluorescent dye and the MTT assay.

MEASUREMENTS AND RESULTS

On admission, the septic shock population's mean age was 55 yrs old, the mean Sequential Organ Failure Assessment score was 12, mean simplified acute physiology score was 50, and intensive care unit mortality rate was 45%. Evaluation of HUVEC antioxidant defenses showed a significantly decreased GSH level, increased catalase activity, and unchanged superoxide dismutase activity. ROS levels and cell death were significantly reduced when cells were pretreated with N-acetylcysteine or GSH, but no changes in reactive nitrogen species were observed.

CONCLUSION

This study demonstrates that plasma-induced ROS production by HUVEC is associated with an intracellular decrease in reduced GSH. Both ROS levels and cell death decreased when N-acetylcysteine or GSH were added before exposing the cells to plasma. These data suggest a pivotal role of alterations in GSH in damage caused by sepsis-generated ROS in endothelial cell.

Pathophysiology of polytrauma

Immediate and early trauma deaths are determined by primary brain injuries, or significant blood loss (haemorrhagic shock), while late mortality is caused by secondary brain injuries and host defence failure. First hits (hypoxia, hypotension, organ and soft tissue injuries, fractures), as well as second hits (e.g. ischaemia/reperfusion injuries, compartment syndromes, operative interventions, infections), induce a host defence response. This is characterized by local and systemic release of pro-inflammatory cytokines, arachidonic acid metabolites, proteins of the contact phase and coagulation systems, complement factors and acute phase proteins, as well as hormonal mediators: it is defined as systemic inflammatory response syndrome (SIRS), according to clinical parameters. However, in parallel, anti-inflammatory mediators are produced (compensatory anti-inflammatory response syndrome (CARS). An imbalance of these dual immune responses seems to be responsible for organ dysfunction and increased susceptibility to infections. Endothelial cell damage, accumulation of leukocytes, disseminated intravascular coagulation (DIC) and microcirculatory disturbances lead finally to apoptosis and necrosis of parenchymal cells, with the development of multiple organ dysfunction syndrome (MODS), or multiple organ failure (MOF). Whereas most clinical trials with anti-inflammatory, anti-coagulant, or antioxidant strategies failed, the implementation of pre- and in-hospital trauma protocols and the principle of damage control procedures have reduced post-traumatic complications. However, the development of immunomonitoring will help in the selection of patients at risk of post-traumatic complications and, thereby, the choice of the most appropriate treatment protocols for severely injured patients.

Redox status of dogs with non-hodgkin lymphomas. An ESR study

Free radical and antioxidant parameters in healthy dogs (n=10) and dogs with non-Hodgkin lymphomas (n=11) were measured in blood and lymph node tissue samples before chemotherapy. Enzymatic and other biochemical measurements were performed. We found that (i) free radical concentrations based on ESR spectra of tissues correlated with higher proliferative character; (ii) lymphoma cases showed an impaired antioxidant status; (iii) tumors with low oxidative burst capacity and higher reduced/oxidized glutathione ratio responded better to chemotherapy; and (iv) affected blood and lymph nodes were under strong oxidative stress.

Assessing the antioxidative status in critically ill patients

PURPOSE OF REVIEW

Oxidative stress is caused by a higher production of reactive oxygen and reactive nitrogen species or a decrease in endogenous protective antioxidative capacity. In all types of critical illness, such as sepsis, trauma, burn injury, acute pancreatitis, liver injury, severe diabetes, acute respiratory distress syndrome, AIDS and kidney failure, the occurrence of increased oxidative stress or a reduced antioxidative status is described. Whereas in the past, reactive oxygen and reactive nitrogen species were mainly known as harmful agents, recent investigations have given a new insight into the (patho)physiological importance of these substances as powerful messenger molecules involved in gene regulation, thereby enabling the synthesis of cytokines or adhesion molecules necessary for defending inflammatory processes. As shown in this review, there are numerous possibilities for the quantification of oxidative stress.

RECENT FINDINGS

Several investigations showed a close association of single or multiple parameters, such as total antioxidative capacity, lipid peroxidation, vitamins C and E, the activation of nuclear factor kappa B, and respiratory burst, with the patient's outcome. However, no recommendation for a single parameter to be measured can be given because the assays described do not allow the definition of an overall "antioxidative status" for patients.

SUMMARY

The occurrence of oxidative stress in critically ill patients is associated with a poor prognosis. The measurement of a cluster of assays representative of the quantification of reactive species or of antioxidants may improve the usefulness of therapeutic intervention and increase knowledge of pathophysiological alterations.

Hepatic ischemia-reperfusion syndrome after partial liver resection (LR): hepatic venous oxygen saturation, enzyme pattern, reduced and oxidized glutathione, procalcitonin and interleukin-6

The hepatic ischemia-reperfusion syndrome was investigated in 28 patients undergoing elective partial liver resection with intraoperative occlusion of hepatic inflow (Pringle maneuver) using the technique of liver vein catheterization. Hepatic venous oxygen saturation (ShvO2) was monitored continuously up to 24 hours after surgery. Aspartate aminotransferase, glutamate dehydrogenase, gamma-glutamyl transpeptidase, pseudocholinesterase, alpha-glutathione S-transferase, reduced and oxidized glutathione, procalcitonine, and interleukin-6 were serially measured both before and after Pringle maneuver during the resection and postoperatively in arterial and/or hepatic venous blood. ShvO2 measurement demonstrated that peri- and postoperative management was suitable to maintain an optimal hepatic oxygen supply. As expected, we were able to demonstrate a typical enzyme pattern of postischemic liver injury. There was a distinct decrease of reduced glutathione levels both in arterial and hepatic venous plasma after LR accompanied by a strong increase in oxidized glutathione concentration during the phase of reperfusion. We observed increases in procalcitonin and interleukin-6 levels both in arterial and hepatic venous blood after declamping. Our data support the view that liver resection in man under conditions of inflow occlusion resulted in ischemic lesion of the liver (loss of glutathione synthesizing capacity with disturbance of protection against oxidative stress) and an additional impairment during reperfusion (liberation of reactive oxygen species, local and systemic inflammation reaction with cytokine production). Additionally, we found some evidence for the assumption that the liver has an export function for reduced glutathione into plasma in man.

Procalcitonin following elective partial liver resection--origin from the liver?

BACKGROUND

The origin of the inflammatory peptide procalcitonin (PCT) is still unknown. In the present study PCT concentrations in arterial and hepatic-venous blood were examined in patients undergoing elective partial liver resection (LR) using a fiberoptic pulmonary arterial catheter placed in a liver vein to obtain further information on the origin of PCT.

METHODS

In 28 patients (21 male/7 female; average age of 58.8+/-8.8 years) undergoing LR, arterial and hepatic venous PCT concentrations were measured during 24 h perioperatively. The parallel blood withdrawals occurred immediately before the Pringle maneuver (Hx), 2 min, 1, 2, 6, 12, and 24 h after Hx. Over the whole period, the oxygen saturation in hepatic venous blood (ShvO2) was monitored. PCT concentrations were assayed by immunoluminometry.

RESULTS

We observed a significant increase in PCT concentration already 6 h after Hx compared to the values before Hx. Twenty-four hours after Hx we found the highest plasma concentrations. It was conspicuous that hepatic venous PCT concentrations were always higher than the arterial ones (significantly from the 6th hour after Hx). There was no correlation between the courses of ShvO2 and PCT rise. A significant correlation was verified between Hx duration and PCT concentration measured 24 h after Hx both in the hepatic venous and arterial blood.

CONCLUSIONS

The results of our investigation can be interpreted as evidence that liver (or the hepatosplanchnicus?) is a source of PCT. The mechanism of PCT induction cannot be clarified by our study: whether the induction of PCT was caused by an endotoxin translocation during the impeded splanchnic outflow or by the direct surgery-induced lesion (hypoxia) of the liver remains unclear. However, the latter appears more probable because of the observed correlation between Hx duration and PCT concentration rise.

Reduced serum total reductive capacity in lethal severe trauma

BACKGROUND

Risk assessment is a prerequisite for effective treatment and triage in severe injury. A novel substrate-based assay to measure total reductive capacity (TORC) in serum was used to stratify risk of lethal outcome in severe trauma in a clinical trial.

METHODS

Serum of patients with severe trauma (Injury Severity Score > 19) was obtained at the accident site, at admission, and at regular intervals thereafter. TORC was determined and correlated to outcome. The TORC assay uses thiol-labeled arachidonic acid as substrate from which free thiols are released by reductive amino acids and the specific activity of phospholipase A2. Free thiols are coupled to monochrombimone, and the resulting fluorescence is proportional to TORC.

RESULTS

Eighteen patients with lethal severe trauma and 16 patients who survived were studied. Injury Severity Scores (lethal, 33 (29--43); survival, 31 (25--42); p = NS) and Polytrauma Scores (lethal, 25 [18--32]; survival, 26 [23--31], p = NS) were not significantly different. At the accident site, patients with a lethal course had significantly lower TORC than nonlethal cases (59.2 +/- 5.1 ng/mL vs. 89.5 +/- 6.7 ng/mL; p < 0.001). Values at admission were similar (lethal, 51.2 +/- 7 ng/mL; survival, 73.8 +/- 9 ng/mL; p < 0.01). At the accident site and at admission, TORC < 82.3 ng/mL was prognostic of lethal outcome (sensitivity, 88%; specificity, 65%/73% and 69%, respectively, for admission).

CONCLUSION

Serum reductive potential at the site of accident or at admission allows the stratification of trauma patients with respect to lethal outcome in severe trauma when severity scores fail to do so.

Erythrocyte deformability is a nitric oxide-mediated factor in decreased capillary density during sepsis

Erythrocyte deformability has been recognized as a determinant of microvascular perfusion. Because nitric oxide (NO) is implicated in the modulation of red blood cell (RBC) deformability and NO levels increase during sepsis, we tested the hypothesis that a NO-mediated decrease in RBC deformability contributes to decreased functional capillary density (CD) in remote organs. With the use of a peritonitis model of sepsis in the rat [cecal ligation and perforation (CLP)] and aminoguanidine (AG) to prevent increases in NO, we measured CD in skeletal muscle (intravital microscopy), mean erythrocyte membrane deformability (; micropipette aspiration), systemic NO production [plasma nitrite/nitrate (NO(x)) chemiluminescence], and NO accumulation in RBC [NO bound to hemoglobin (HbNO) detected by electron paramagnetic resonance spectroscopy]. In untreated CLP animals relative to sham, NO(x) increased 254% (P < 0.05), stopped flow capillaries increased 149% (P < 0.05), and decreased 12.7% (P < 0.05), with a subpopulation (5%) of RBC with deformabilities below the normal range. AG prevented increases in NO(x), accumulation of HbNO, and decreases in both and functional CD. We found no evidence of leukocyte plugging postcapillary venules. Our findings suggest that decreased functional CD during sepsis resulted from a NO-mediated decrease in erythrocyte deformability.

N-acetylcysteine replenishes glutathione in HIV infection

BACKGROUND

Glutathione (GSH) deficiency is common in HIV-infected individuals and is associated with impaired T cell function and impaired survival. N-acetylcysteine (NAC) is used to replenish GSH that has been depleted by acetaminophen overdose. Studies here test oral administration of NAC for safe and effective GSH replenishment in HIV infection.

DESIGN

Oral NAC administration in a randomized, 8-week double-blind, placebo-controlled trial followed by optional open-label drug for up to 24 weeks.

SUBJECTS

HIV-infected, low GSH, CD4 T cells < 500 micro L(-1), no active opportunistic infections or other debilitation; n = 81. Study conducted prior to introduction of protease inhibitors.

RESULTS

Whole blood GSH levels in NAC arm subjects significantly increased from 0.88 mM to 0.98 mM, bringing GSH levels in NAC-treated subjects to 89% of uninfected controls (P = 0.03). Baseline GSH levels in the placebo group (0.91) remained essentially the same during the 8 week placebo-controlled trial. T cell GSH, adjusted for CD4 T cell count and beta2-microglobulin levels, also increased in the NAC-treated subjects (P = 0.04). Adverse effects were minimal and not significantly associated with NAC ingestion.

CONCLUSION

NAC treatment for 8 weeks safely replenishes whole blood GSH and T cell GSH in HIV-infected individuals. Thus, NAC offers useful adjunct therapy to increase protection against oxidative stress, improve immune system function and increase detoxification of acetaminophen and other drugs. These findings suggest that NAC therapy could be valuable in other clinical situations in which GSH deficiency or oxidative stress plays a role in disease pathology, e.g. rheumatoid arthritis, Parkinson's disease, hepatitis, liver cirrhosis, septic shock and diabetes.

Lung glutathione and oxidative stress: implications in cigarette smoke-induced airway disease

Glutathione (GSH), a ubiquitous tripeptide thiol, is a vital intra- and extracellular protective antioxidant in the lungs. The rate-limiting enzyme in GSH synthesis is gamma-glutamylcysteine synthetase (gamma-GCS). The promoter (5'-flanking) region of the human gamma-GCS heavy and light subunits are regulated by activator protein-1 and antioxidant response elements. Both GSH and gamma-GCS expression are modulated by oxidants, phenolic antioxidants, and inflammatory and anti-inflammatory agents in lung cells. gamma-GCS is regulated at both the transcriptional and posttranscriptional levels. GSH plays a key role in maintaining oxidant-induced lung epithelial cell function and also in the control of proinflammatory processes. Alterations in alveolar and lung GSH metabolism are widely recognized as a central feature of many inflammatory lung diseases including chronic obstructive pulmonary disease (COPD). Cigarette smoking, the major factor in the pathogenesis of COPD, increases GSH in the lung epithelial lining fluid of chronic smokers, whereas in acute smoking, the levels are depleted. These changes in GSH may result from altered gene expression of gamma-GCS in the lungs. The mechanism of regulation of GSH in the epithelial lining fluid in the lungs of smokers and patients with COPD is not known. Knowledge of the mechanisms of GSH regulation in the lungs could lead to the development of novel therapies based on the pharmacological or genetic manipulation of the production of this important antioxidant in lung inflammation and injury. This review outlines 1) the regulation of cellular GSH levels and gamma-GCS expression under oxidative stress and 2) the evidence for lung oxidant stress and the potential role of GSH in the pathogenesis of COPD.

Inflammation and the regulation of glutathione level in lung epithelial cells

Inflammation is a highly complex biochemical protective response to cellular injury. If this process is continuously unchecked, it leads to chronic inflammation, a hallmark of various inflammatory lung diseases. Reactive oxygen intermediates generated by immune cells recruited to the sites of inflammation are a major cause of cell damage. Glutathione (GSH), is a vital intra- and extracellular protective antioxidant in the lungs. The rate-limiting enzyme in GSH synthesis is gamma-glutamylcysteine synthetase (gamma-GCS). Both GSH and gamma-GCS expression are modulated by oxidants, phenolic antioxidants, inflammatory, and anti-inflammatory agents in lung cells. GSH plays a key role in regulating oxidant-induced lung epithelial cell function and also in the control of pro-inflammatory processes. Alterations in the alveolar and lung GSH metabolism are widely recognized as a central feature of many inflammatory lung diseases. Oxidative processes have a fundamental role in lung inflammation through redox-sensitive transcription factors such as NF-kappaB and AP-1, which regulated the genes for pro-inflammatory mediators and protective antioxidant genes such as gamma-GCS. The critical balance between the induction of pro-inflammatory mediators and antioxidant genes in response to oxidative stress at the site of inflammation is not known. Knowledge of the mechanisms of GSH regulation in lung inflammation could lead to the development of novel therapies based on the pharmacological manipulation of the production of this important antioxidant in lung inflammation and injury. This review describes the potential role of GSH for lung oxidant stress, inflammation and injury.