Oxidative stress in kidney disease patients

Patients with chronic kidney disease are exposed to oxidative stress (OS) that contributes to deterioration of health. Decrease in renal excretory capacity contributes to the accumulation of pro-oxidative substances that are detrimental not only to kidney but to the whole organism including the cardiovascular system. Components of antioxidant system play an important role in the elimination of the OS. The monitoring of antioxidant levels and products of oxidative damage in these patients and the correct interpretation of relationship between these markers and the function of kidney and other organs may contribute to the more effective treatment and health improvement of the patients.     

Oxidative stress in severe dengue viral infection: association of thrombocytopenia with lipid peroxidation

Oxidative stress in viral infections has been suggested. The study was carried out to assess the oxidative stress in the different clinical spectrums of dengue infection and to evaluate if thrombocytopenia is associated with lipid and protein oxidative injury. Twenty-seven dengue fever (DF), 32 dengue hemorrhagic fever (DHF) and 21 dengue shock syndrome (DSS) cases were studied at 3, 5 and 7 days of illness. Sixty-three healthy subjects were selected as controls. Serum protein carbonyls (PCOs), malendialdehyde (MDA) and total antioxidant status (TAS) were estimated in blood. Dengue infected individuals had significantly high levels of PCOs and MDA on the three days tested in comparison to controls. In DF cases, no significant changes in the levels of MDA and PCOs were found in course of time. However, among DHF and DSS, significant increase in MDA levels was found in the fifth and seventh day samples in comparison to their respective third day sample (P < 0.05). Using one way ANOVA, high PCOs levels were found in DSS in comparison to DF and DHF cases on all the three days tested (P < 0.001). TAS levels were found to be low among DSS on days 5 and 7 and day 7 in DHF when compared with DF cases. Correlation analysis between MDA and hematocrit revealed a significant positive association between them in DHF and DSS on day 5 (DHF r = 0.372; p = 0.024 and DSS r = 0.535; p = 0.0-01) and day 7 (DHF r = 0.412; p = 0.003 and DSS r = 0.765; p < 0.0001). There was an important negative correlation between platelet count and plasma lipid peroxidation levels among DHF and DSS on all three days tested [day 3 (DHF r = -0.392; p = 0.012 and DSS r = -0.453; p = 0.004), day 5 (DHF r = -0.592; p < 0.001 and DSS r = -0.581; p < 0.001) and day 7 (DHF r = -0.418; p = 0.001 and DSS r = -0.515; p = 0.002)]. This study concludes that an increase in oxidative stress was found in dengue viral infection. The level of oxidative stress was maximal in DSS followed by DHF and its severity was minimal in DF. The thrombocytopenia of dengue infection was associated with the extent of lipid peroxidation. Future studies might be carried out to find the role of oxidative damage in the ethiopathogenesis of thrombocytopenia and vascular leakage in dengue infection.     

Oxidative stress in severe dengue viral infection: Association of thrombocytopenia with lipid peroxidation

Oxidative stress in viral infections has been suggested. The study was carried out to assess the oxidative stress in the different clinical spectrums of dengue infection and to evaluate if thrombocytopenia is associated with lipid and protein oxidative injury. Twenty-seven dengue fever (DF), 32 dengue hemorrhagic fever (DHF) and 21 dengue shock syndrome (DSS) cases were studied at 3, 5 and 7 days of illness. Sixty-three healthy subjects were selected as controls. Serum protein carbonyls (PCOs), malendialdehyde (MDA) and total antioxidant status (TAS) were estimated in blood. Dengue infected individuals had significantly high levels of PCOs and MDA on the three days tested in comparison to controls. In DF cases, no significant changes in the levels of MDA and PCOs were found in course of time. However, among DHF and DSS, significant increase in MDA levels was found in the fifth and seventh day samples in comparison to their respective third day sample (P < 0.05). Using one way ANOVA, high PCOs levels were found in DSS in comparison to DF and DHF cases on all the three days tested (P < 0.001). TAS levels were found to be low among DSS on days 5 and 7 and day 7 in DHF when compared with DF cases. Correlation analysis between MDA and hematocrit revealed a significant positive association between them in DHF and DSS on day 5 (DHF r = 0.372; p = 0.024 and DSS r = 0.535; p = 0.0–01) and day 7 (DHF r = 0.412; p = 0.003 and DSS r = 0.765; p < 0.0001). There was an important negative correlation between platelet count and plasma lipid peroxidation levels among DHF and DSS on all three days tested [day 3 (DHF r = ?0.392; p = 0.012 and DSS r = ?0.453; p = 0.004), day 5 (DHF r = ?0.592; p < 0.001 and DSS r = ?0.581; p < 0.001) and day 7 (DHF r = ?0.418; p = 0.001 and DSS r = ?0.515; p = 0.002)]. This study concludes that an increase in oxidative stress was found in dengue viral infection. The level of oxidative stress was maximal in DSS followed by DHF and its severity was minimal in DF. The thrombocytopenia of dengue infection was associated with the extent of lipid peroxidation. Future studies might be carried out to find the role of oxidative damage in the ethiopathogenesis of thrombocytopenia and vascular leakage in dengue infection.     

Acute respiratory failure in adult patients with dengue virus infection

To investigate clinical course and outcome of dengue with acute respiratory failure (ARF), and to identify related risk factors for acquiring ARF in dengue, we retrospectively studied 11 dengue patients with ARF. From June to December 2002, a total of 606 adult patients were diagnosed as having dengue. Eleven (1.8%) of 606 dengue patients had complications of ARF. The main causes of ARF were sepsis (n = 6, 54.5%) and upper gastrointestinal (UGI) bleeding (n = 3, 27.3%). The mortality rate was 72.7% (n = 8). Additionally, univariate analysis showed that age, dyspnea, cough, prothrombin time, activated partial thromboplastin time, aspartate aminotransferase, alanine aminotransferase, blood urea nitrogen, creatinine, albumin, renal insufficiency, acute renal failure, acute hepatic failure, UGI bleeding, and combination bacterial infection were significantly predictive variables associated with dengue patients with ARF.     

Oxidative stress in patients with acute heart failure

Oxidative stress (OS) is a keystone in the pathology of the ischemia reperfusion sequence (acute coronary syndromes, cardiac surgery, transplantation). In heart failure, the implication of OS is less understood. This study was intended to evaluate OS in acute heart failure. Criteria for inclusion were consecutive patients hospitalized in our cardiology department for a first pulmonary edema that revealed a dilated cardiomyopathy (DCM). Exclusion criteria included known cardiomyopathy, smoker, acute coronary syndrome, and treatment with angiotensin converting enzyme inhibitors (ACEI) or angiotensin II receptor blockers (ARAII). OS was evaluated in blood samples: thiobarbituric acid-reactive substances (TBARS), total antioxidant status (TAS), plasma alpha-tocopherol, vitamin A, and beta-carotene. Standard biochemical parameters including CRP, fibrinogen, lipid, and creatinine were assayed. Ten patients (80% men, mean age 55.3 +/- 7.9 years) were included and followed during a 6 month period. The etiologies of DCM were alcohol (n = 3), anti-cancer drugs (n = 2), valvulopathies (n = 2), or idiopathic (n = 3). In acute heart failure, TBARS were elevated (1.69 micromol/L; normal value 0.6-4.2 micromol/L) and TAS status was decreased (0.96 mmol/L; normal value 1.3-1.9 pmol/L). OS was more important when patients had atrial or ventricular arrhythmia. Nevertheless, liposoluble antioxidant parameters (beta-carotene, vitamin A, alpha-tocopherol) had a usual value. At the term of the follow-up, patients returned to a stable condition, OS markers revealed normal values, and every Holter ECG showed no supraventricular or ventricular arrhythmias. In acute heart failure, oxygen-free radicals are increased. We thus hypothetized that a modification in OS could be responsible for arrhythmias and complications of acute heart failure.     

Oxidative stress analysis in patients on hemodiafiltration on-line

Patients with chronic renal disease have a very high mortality due to cardiovascular disease. However, the traditional risk factors are not the only one explanation. Nowadays, there are new risk factors becoming, and one of these is the oxidative stress. Besides today we know that when these patients receive haemodialysis are being exposed to an additional oxidative stress. The aim of this study was to measure and to compare the degree of oxidative stress in two groups of patients on different dialysis techniques: a) On-Line Haemodiafiltration three times / week (OL-HDF). b) Daily Om-Line haemodiafiltration ( six times / week ) ( dOL-HDF) We studied 9 patients with chronic renal disease stage 5 on hemodialysis. They all were men, with a medium age of 72,5 +/- 6 years. Five patients were on dOL-HDFand four on tOL-HDF. Glutathione (GSH) concentration of patients on dOL-HDF before dialysis was 742+/- 153 nmol/ml and post-dialysis de 878+/- 223. Blood GSSG concentration before and after dialysis was 34+/- 14 nmol/ml y 137+/- 74 nmol/ml (p< 0,03). GSSG/GSH ratio pre-dialysis was 58+/-10 and post-dialysis 169+/-65 ( p < 0,03). In OL-HDF group GSSG concentration and the ratio GSSG/GSH also increased in a significative way from 99+/-45 nmol/ml to 179+/-66 nmol/ml, and from 161+/- 99 to 337+/-143 ( p<0,05). We also found differences in pCR concentrations between both groups; 3+/-1,4 g/l in dOL-HDF and 8,75+/-5,8 g/l in HDF OL. (p< 0,05). We did not find differences between xatine-oxidase activity before and after hemodialysis and between groups. In conclusion, patient with terminal chronic renal disease on OL-HDF receive an additional load of oxidative stress, as the increase in GSSG/GSH ratio in both groups shows. However patients on dHDF-OL shows low ratios GSSG/GSH post-hemodialysis and low pCR concentrations, and maybe this could be explained because daily on line haemodiafiltration improves purification of inflammatory mediators. Clue words: Hemodialysis, oxidative stress, glutathione, gssg/gsh ratio, xantine oxidasa.     

Oxidative stress in blood platelets from schizophrenic patients

Oxidative stress in blood platelets is observed in various diseases, including neuropsychiatric disorders. The aim of our study was to evaluate oxidative stress in blood platelets from patients with schizophrenic disorders by measuring the activity of the platelet antioxidative enzyme, superoxide dismutase (SOD), concomitant with the level of thiobarbituric acid reactive species (TBARS). In blood platelets obtained from schizophrenic patients (with paranoid schizophrenia according to DSM-IV criteria) and from healthy volunteers the level of reactive oxygen species was also measured via chemiluminescence. In resting blood platelets from schizophrenic patients the chemiluminescence was higher than in platelets from control subjects (P?<?0.05), but in thrombin-activated platelets an increase (about 53%) of chemiluminescence was observed, however this increase was lower than in thrombin-stimulated platelets from healthy subjects (101.5%). The results indicate that in platelets from schizophrenic patients generation of reactive oxygen species is enhanced. Moreover, we observed that SOD activity in blood platelets from schizophrenic patients was significantly lower than in control platelets and that a correlation exists between increased lipid peroxidation and inhibition of the activity of this antioxidative enzyme in schizophrenic platelets.     

Oxidative stress in blood platelets from schizophrenic patients

Oxidative stress in blood platelets is observed in various diseases, including neuropsychiatric disorders. The aim of our study was to evaluate oxidative stress in blood platelets from patients with schizophrenic disorders by measuring the activity of the platelet antioxidative enzyme, superoxide dismutase (SOD), concomitant with the level of thiobarbituric acid reactive species (TBARS). In blood platelets obtained from schizophrenic patients (with paranoid schizophrenia according to DSM-IV criteria) and from healthy volunteers the level of reactive oxygen species was also measured via chemiluminescence. In resting blood platelets from schizophrenic patients the chemiluminescence was higher than in platelets from control subjects (P < 0.05), but in thrombin-activated platelets an increase (about 53%) of chemiluminescence was observed, however this increase was lower than in thrombin-stimulated platelets from healthy subjects (101.5%). The results indicate that in platelets from schizophrenic patients generation of reactive oxygen species is enhanced. Moreover, we observed that SOD activity in blood platelets from schizophrenic patients was significantly lower than in control platelets and that a correlation exists between increased lipid peroxidation and inhibition of the activity of this antioxidative enzyme in schizophrenic platelets.     

Oxidative stress induced changes in plasma protein can be a predictor of imminent severe dengue infection

OBJECTIVES: Oxidative stress in dengue viral infection has been suggested and severity of it was found to be associated with progress of illness. Hence assessing oxidative stress mediated changes in plasma proteins can be an early biomarker for prediction of severe dengue infection. DESIGN AND METHODS: Thirty two dengue hemorrhagic fever (DHF), 21 dengue shock syndrome (DSS), 27 dengue fever (DF) and 63 age and sex matched controls, were included in this study. Blood samples were collected on the 3rd day of fever. Protein carbonylation (PCOs) and protein-bound sulphydryl (PBSH) group levels were determined by spectrophotometric method and analyzed as predictor of dengue hemorrhagic fever and dengue shock syndrome. RESULTS: About 80-84% of cases presented with no signs of DHF/DSS at the time of sampling. Dengue infected individuals had significantly elevated PCOs and low PBSH group levels than the controls. Using one-way ANOVA we found a significant difference with high PCOs and low PBSH group levels between DHF and DSS when compared with DF (P<0.001). However, no difference was observed in PBSH group levels between DHF and DSS. A significant difference in PCOs to PBSH ratio was observed among DF, DHF and DSS (P<0.001). Linear regression analysis revealed that duration of hospitalization is dependent on PCOs and PBSH group levels. Receiver operator curve (ROC) analysis indicated that 5.22nmol/mg protein PCOs; 1.08 PCOs to PBSH group levels ratio were optimal cutoff value for predicting DHF with sensitivity and specificity of 87.5% and 74.1%; 96.9% and 81.5%, respectively. For DSS prediction, 6.13 nmol/mg protein PCOs; 1.16 PCOs to PBSH group levels ratio were found as effective cutoff with sensitivity and specificity of 81% and 71.9%; 95.2% and 56.2%, respectively. CONCLUSION: Oxidative stress has been observed to develop since early days of onset of dengue infection. Plasma PCOs, PCOs to PBSH group ratio were found to very well predict DHF/DSS.     

Oxidative stress contributes to sex differences in blood pressure in adult growth-restricted offspring

Numerous experimental studies suggest that oxidative stress contributes to the pathophysiology of hypertension and, importantly, that oxidative stress plays a more definitive role in mediating hypertension in males than in females. Intrauterine growth restriction induced by reduced uterine perfusion initiated at day 14 of gestation in the rat programs hypertension in adult male growth-restricted offspring; yet, female growth-restricted offspring are normotensive. The mechanisms mediating sex differences in blood pressure in adult growth-restricted offspring are not clear. Thus, this study tested the hypothesis that sex-specific differences in renal oxidative stress contribute to the regulation of blood pressure in adult growth-restricted offspring. A significant increase in blood pressure measured by telemetry in male growth-restricted offspring (P<0.05) was associated with a marked increase in renal markers of oxidative stress (P<0.05). Chronic treatment with the antioxidant Tempol had no effect on blood pressure in male control offspring, but it normalized blood pressure (P<0.05) and renal markers of oxidative stress (P<0.05) in male growth-restricted offspring relative to male control offspring. Renal markers of oxidative stress were not elevated in female growth-restricted offspring; however, renal activity of the antioxidant catalase was significantly elevated relative to female control offspring (P<0.05). Chronic treatment with Tempol did not significantly alter oxidative stress or blood pressure measured by telemetry in female offspring. Thus, these data suggest that sex differences in renal oxidative stress and antioxidant activity are present in adult growth-restricted offspring and that oxidative stress may play a more important role in modulating blood pressure in male but not female growth-restricted offspring.     

Oxidative stress in blood of patients with alcohol-related pancreatitis

To determine the possible role of oxidative stress in alcoholic pancreatitis, the authors measured the ability of blood neutrophils of 22 patients with acute and 20 patients with chronic alcoholic pancreatitis to produce superoxide anion (O2-) and hydrogen peroxide (H2O2), spontaneously and after in vitro stimulation with phorbol ester and compared it with that of neutrophils isolated from the blood of 16 healthy controls. In addition, they measured serum activities of superoxide dismutase, catalase, and the serum concentration of glutathione peroxidase (GPx). Phorbol ester-induced O2- and H2O2 production in neutrophils of patients with acute and chronic pancreatitis was greater than in controls, but these differences, except of superoxide anion production by neutrophils of patients with chronic pancreatitis, were not statistically significant because of large individual differences. Spontaneous resting production of O2- and H2O2 by neutrophils of patients with chronic pancreatitis was significantly greater than in the controls. Superoxide dismutase and catalase activity was greater in sera of both groups of patients with acute and chronic alcoholic pancreatitis than in controls, but GPx concentration was significantly less in the sera of patients with chronic pancreatitis. Impaired GPx production and increased production of O2- and H2O2 by neutrophils may result in increased lipid peroxidation and could play a role in the pathogenesis of chronic alcoholic pancreatitis.     

Oxidative stress in patients with obstructive sleep apnea syndrome

Purpose

We aimed to investigate whether systemic oxidative stress is increased in patients with obstructive sleep apnea syndrome (OSAS).

Methods

A total of 18 patients with severe OSAS and 13 controls were included in the study. Inclusion criteria for OSAS patients were: snoring and apnea–hypopnea index (AHI) of >30 in full polysomnography, no previous treatment for OSAS, non-smoking status, and a medical history of being free of comorbidities known to increase oxidative stress. Controls were recruited among subjects assessed for snoring in the Sleep Laboratory Department if they had AHI<5. At baseline, patients were evaluated by the Epworth Sleepiness Scale and underwent spirometry, echocardiography, and full polysomnographic study. Blood samples were collected for evaluation of oxidative stress biomarkers [protein carbonyls, reduced (GSH) and oxidized (GSSG) glutathione, 8-isoprostane, thiobarbituric acid-reactive substances (TBARS), catalase activity, Cu–Zn superoxide dysmutase (SOD), total antioxidant capacity (TAC)] before and on the morning following polysomnography.

Results

The overnight (morning–night) change (%) of GSH/GSSG ratio and GSH was significantly different between OSAS and controls (p?=?0.03 and p?=?0.048, respectively). Plasma protein carbonyls, erythrocyte catalase activity, 8-isoprostane, SOD, TBARS, and TAC plasma values were not different between OSAS and controls (p?>?0.05). No significant correlation was found between changes in the levels of biomarkers and AHI, arousal, or desaturation index.

Conclusion

The present prospective investigation in a population free of comorbidities or factors which may increase systemic oxidative stress provides evidence that obstructive sleep apnea per se might be associated with increased oxidative burden possibly via GSH/GSSG pathway.     

Oxidative stress status in patients with chronic idiopathic urticaria

AimThe controversial data related to oxidative stress status in patients with chronic idiopathic urticaria (CIU) have been reported. Therefore, the present study was aimed to contribute to this debate by determining oxidative stress markers along with some trace element levels in patients with CIU.MethodsTwenty-five patients with CIU (10 males, 15 females) and 36 healthy controls were enrolled into the study. Erythrocyte lipid peroxidation status, scavenger enzyme activities and trace element levels were determined.ResultsWhile erythrocyte MDA levels, erythrocyte GSH- Px activities and erythrocyte Zn levels showed no differences between the patient and control groups, a statistically significant decrease and increase were observed in erythrocyte CuZn-SOD activities and Cu levels, respectively, in the CIU patients when compared to those of the controls (p < 0.001 for both of them).ConclusionIn conclusion, an oxidative burden which can be relieved by some preserved antioxidant mechanisms seems to be present in patients with CIU even if they are clinically stable and it may probably have a role in the pathogenesis.     

Oxidative stress in erythrocytes from patients with rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune disease characterized by chronic inflammation. It has been suggested that the level of reactive oxygen species (ROS) in patients with RA is higher than in healthy subjects. The aim of the present study was to investigate the level of the lipid peroxidation, antioxidant enzyme activities (CAT, SOD, GSH-Px), level of the –SH groups and GSH and Na⁺K⁺ ATPase activity in erythrocytes from patients with RA. There are no significant differences in CAT and GSH-Px activities. SOD activity is lower in RA patients than in the control group. Increase in the lipid peroxidation is observed in RA patients. Levels of the GHS and –SH groups are significantly lower in RA patients than in the control groups. Total ATPase and Na⁺K⁺ ATPase activities decrease in RA patients.     

Oxidative stress in aldosteronism

Congestive heart failure (CHF) is more than a failing heart and salt-avid state. Also present is a systemic illness which features oxidative stress in diverse tissues, a proinflammatory phenotype, and a wasting of soft tissue and bone. Reactive oxygen and nitrogen species contribute to this illness and the progressive nature of CHF. Aldosteronism, an integral component of the neurohormonal profile found in CHF, plays a permissive role in leading to an altered redox state. Because of augmented urinary and fecal excretion of Ca(2+) and Mg(2+) and consequent decline in plasma-ionized [Ca(2+)](o) and [Mg(2+)](o) that accompanies aldosteronism, parathyroid glands release parathyroid hormone (PTH) in an attempt to restore Ca(2+) and Mg(2+) homeostasis; this includes bone resorption. However, PTH-mediated intracellular Ca(2+) overloading, considered a Ca(2+) paradox, leads to oxidative stress. This can be prevented by: spironolactone, an aldosterone receptor antagonist that rescues urinary and fecal cation losses; parathyroidectomy; amlodipine, a Ca(2+) channel blocker; N-acetylcysteine, an antioxidant. In addition to the role played by aldosteronism in the appearance of secondary hyperparathyroidism is the chronic use of a loop diuretic, which further enhances urinary Ca(2+) and Mg(2+) excretion, and reduced Ca(2+) stores associated with hypovitaminosis D. This broader perspective of CHF and the ever increasing clinical relevance of divalent cations and oxidative stress raise the question of their potential management with macro- and micronutrients. An emerging body of evidence suggests the nutritional management of CHF offers an approach that will be complementary to today's pharmaceutical-based strategies.     

Oxidative stress in hypertension

Several experimental and clinical evidences have linked an enhanced production of reactive oxygen species (ROS) to certain diseases of the cardiovascular system including hypertension and diabetes. However, it has never been clearly established whether the enhanced oxidative stress observed in those conditions is primary or secondary to the pathological process. Our experimental studies have permitted to demonstrate that ROS, mainly through the production of superoxide anion, can cause important alterations in the cellular signal transduction systems characterized by an enhanced production of inositol triphosphate and a reduced production of cyclic GMP in cultured vascular smooth muscle cells (SMC), thus favouring the vasoconstriction. Since those effects were found to be increased in SMC from spontaneously hypertensive rats (SHR), this suggested a greater sensitivity of the vascular tissue of SHR to the oxidative stress. Moreover, we also have observed an increased production of superoxide anion in the aorta of rats made hypertensive according to the SHR, glucose or angiotensin-induced and DOCA-salt models during the development of hypertension. Since the superoxide anion production could be correlated with the level of blood pressure and since the development of hypertension could be either totally prevented or markedly attenuated by chronic treatment with potent antioxidative therapies such as alpha lipoic acid or aspirin, this suggested a major contribution of vascular superoxide anion production in the development of hypertension in those models. Moreover, the development of insulin resistance, which is associated to the model of glucose-induced hypertension, was also found to be prevented by chronic antioxidant therapies, thus suggesting that oxidative stress plays an important role as well in the development of insulin resistance and type 2 diabetes. In conclusion, it appears that oxidative stress may constitute a major pathogenic factor in the development of hypertension and type 2 diabetes. Moreover, our studies suggest that the chronic treatment with appropriate antioxidative therapies could prevent the development of hypertension and diabetes as well as their complications in various experimental models of hypertension.     

Oxidative stress in non-insulin-dependent diabetes mellitus (NIDDM) patients

Diabetes mellitus is a metabolic disorder characterized by hyperglycemia. The oxidative stress in diabetes was greatly increased due to prolonged exposure to hyperglycemia and impairment of oxidant/antioxidant equilibrium. Proteins and lipids are among the prime targets for oxidative stress. In the present study, the oxidative stress was evaluated in 55 diabetic patients and 40 healthy subjects by measuring the levels of protein oxidation, lipid peroxidation and some enzymatic and nonenzymatic antioxidants. The oxidative products of protein (PCG) and lipid peroxidation (MDA) and nitric oxide levels in plasma of NIDDM patients were significantly increased. However, the levels of enzymatic (GPx, SOD, catalase in RBC) and nonenzymatic (β-carotene, retinol, vitamin C & E and uric acid) antioxidants of RBC showed a significant decrease in NIDDM patients compared to normal subjects. Serum protein analysis by polyacrylamide gel electrophoresis (PAGE) showed the significant difference in the ceruloplasmin, transferrin, albumin, retinal binding protein, etc. in diabetic patients compared to healthy controls. In conclusion, the results suggest that increased protein oxidation, lipid peroxidation and NO levels, decreases the levels of enzymatic and nonenzymatic antioxidants and playing a major role in diabetic complications.     

Oxidative stress and thyroid hormones in patients with liver diseases

BackgroundThe liver metabolizes the thyroid hormones and regulates their systemic endocrine effects so liver disease could affect thyroid hormone metabolism. Oxidative stress could play a role in the pathogenesis and progression of liver diseases. The objective of this study was to investigate serum levels of oxidative stress and antioxidant in liver diseases as prognostic markers and know the importance of these antioxidants level in relation to thyroid hormones.MethodsSerum nitric oxide (NO), malondialdehyde (MDA) and triiodothyronine (T₃), thyroxine (T₄), thyroid stimulating hormone (TSH), apolipoprotein-1 (APOA1) levels and erythrocyte reduced glutathione (GSH) level and glutathione peroxidase (GSHPx) and glutathione reductase (GR) activities were determined in 20 control subjects, 13 patients with non-alcoholic steatohepatitis (NASH), 18 patients with chronic HCV, 17 patients with compensated cirrhotic HCV and 42 patients with decompensated cirrhotic HCV.ResultsCirrhotic patients with HCV had higher NO and MDA levels while lower T₃ and erythrocyte GSH levels, and GSHPx activity than the chronic. Serum T₃ showed negative correlation with serum NO and MDA whereas positive correlation with APOA1, GSH, and GSHPx in cirrhotic patients with HCV.ConclusionThe measurement of the total T₃, NO, MDA, GSH reduced and GSHPx as biomarkers for liver diseases might be a beneficial tool, helping in monitoring the state of liver disease patients.     

Oxidative stress is exacerbated in diabetic patients during cardiopulmonary bypass

Circulation on blood extracorporeally through plastic tubing activates several pathways including systemic inflammation and oxidative stress. These phenomena are suspected to participate to neurological and cardiovascular side effects observed in the patients under cardiopulmonary bypass (CPB). A direct relationship, in diabetic patients, between hyperglycemia and morbidity and mortality has been established. However, it is still unclear whether perioperative hyperglycemia has a direct effect on adverse events in cardiac surgery. The purpose of this study was to determine the influence of hyperglycemia on inflammation and oxidative stress in patients under CPB during cardiac surgery. MATERIAL AND METHODS: Control patients (n=17) and diabetic (type 2) patients (n=13) were included in this study. Blood samples were drawn before, during and after the CPB. Oxidative stress was evaluated in the plasma by direct and indirect approaches. Direct detection of ascorbyl radicals was assessed by electron spin resonance spectroscopy. An index: ascorbyl radical/vitamin C ratio is an indicator of the degree of oxidative stress taking place in the plasma. Oxygen radical absorbing capacity (ORAC) values were used as measurement of antioxidant capacity of the plasma. To determine inflammation profile of patients, we measure the evolution of plasma concentration of interleukin 8 (IL-8). RESULTS: During cross clamping and post-CPB, the index ascorbyl radical/vitamin C is increased; the value of the index is more significant in diabetic patients. Concomitantly, ORAC values decreased in all the patients during cross clamping (p<0.05). Results concerning inflammatory index showed that IL-8 levels increased during the CPB. CONCLUSION: In conclusion, the current study indicates that a systemic oxidative stress occurs during CPB and post-CPB periods and that in patients with type 2 diabetes mellitus, the systemic oxidative stress was increased.