The Impact of MGMT Promoter Methylation and Temozolomide Treatment in Serbian Patients with Primary Glioblastoma.

Background and objective: Despite recent advances in treatment, glioblastoma (GBM) remains the most lethal and aggressive brain tumor. A continuous search for a reliable molecular marker establishes the methylation status of the O6-methylguanine-DNA methyltransferase (MGMT) gene promoter as a key prognostic factor in primary glioblastoma. The aim of our study was to screen Serbian patients with primary glioblastoma for an MGMT promoter hypermethylation and to evaluate its associations with overall survival (OS) and sensitivity to temozolomide (TMZ) treatment. Materials and methods: A cohort of 30 Serbian primary glioblastoma patients treated with radiation therapy and chemotherapy were analyzed for MGMT promoter methylation and correlated with clinical data. Results: MGMT methylation status was determined in 25 out of 30 primary glioblastomas by methylation-specific PCR (MSP). MGMT promoter hypermethylation was detected in 12 out of 25 patients (48%). The level of MGMT promoter methylation did not correlate with patients' gender (p = 0.409), age (p = 0.536), and OS (p = 0.394). Treatment with TMZ significantly prolonged the median survival of a patient (from 5 to 15 months; p < 0.001). Conclusions: Due to a small cohort of primary GBM patients, our study is not sufficient for definitive conclusions regarding the prognostic value of MGMT methylation for the Serbian population. Our preliminary data suggest a lack of association between MGMT promoter methylation and overall survival and a significant correlation of TMZ treatment with overall survival. Further population-based studies are needed to assess the prognostic value of the MGMT promoter methylation status for patients with primary glioblastoma.

The association of CAT-262C/T polymorphism with catalase activity and treatment response in juvenile idiopathic arthritis.

Oxidative stress is believed to be of great importance for both the etiology and the persistence of juvenile idiopathic arthritis (JIA). The aim of this study was to investigate the association of -262C/T polymorphism of the catalase (CAT) gene with JIA, as well as to evaluate whether this polymorphism can influence plasma CAT activity and outcome in JIA patients treated with etanercept. A total of 154 subjects (60 JIA patients and 94 healthy volunteers) were screened for CAT-262C/T gene polymorphism using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Plasma CAT activity was determined using the spectrophotometric method according to Goth, prior to and 12 months after anti-TNF (etanercept) therapy. Clinical outcome was assessed using the JIA ACR (American College of Rheumatology) response criteria. The genotype and allele frequency distributions of CAT-262C/T polymorphism in the patients were significantly different from those of the controls (p = 0.014, p = 0.006). The TT genotype (polymorphic homozygous) was associated with a 4.36-fold higher likelihood of having JIA (95% CI 1.545-12.323, p = 0.005) as compared to the CC genotype (wild-type). At month 12 of treatment, JIA patients, carriers of the CC genotype, showed significantly higher plasma CAT activity (p = 0.004) and achieved the JIA ACR 70 response more often (p = 0.003) than the patients, carriers of the CT/TT genotype. This is the first study implying the possible association of CAT-262C/T polymorphism with JIA. The results suggest the potential protective effect of the CC genotype, with regard to CAT activity and treatment outcome.

Vitamin D receptor gene polymorphism influences lipid profile in patients with juvenile idiopathic arthritis.

Vitamin D receptor (VDR) gene FokI (rs2228570) polymorphism was postulated to influence outcome of several inflammatory diseases. The aim of this study was to evaluate the influence of rs2228570 polymorphism on lipid profile and on outcome in patients with juvenile idiopathic arthritis (JIA) treated with etanercept. A total of 153 subjects (62 JIA patients and 91 controls) were screened for the rs2228570 using the PCR-RFLP method. Lipid profile (cholesterol, triacylglycerol, HDL-C, and LDL-C) was determined using standard biochemical analysis in controls, while in JIA patients, it was determined prior to and 12 months after anti-TNF (etanercept) therapy. Clinical outcome was assessed using the JIA-American College of Rheumatology (ACR) response criteria. There were significant differences in the distribution of genotypes (p = 0.024) and alleles (p = 0.006; OR = 2.222, 95% CI 1.136-4.348) of the rs2228570 between patients and controls. Etanercept treatment significantly increased HDL-C levels (p = 0.006) in JIA patients with FF genotype in comparison to baseline values. No significant differences were seen in JIA-ACR 30/50/70 responses at month 12 between FF and Ff/ff genotype carriers. This is the first study to demonstrate the protective effect of the VDR FokI FF genotype on lipid profile in JIA patients treated with etanercept. However, this has to be confirmed in a larger cohort of patients.

Oral supplementation with melatonin reduces oxidative damage and concentrations of inducible nitric oxide synthase, VEGF and matrix metalloproteinase 9 in the retina of rats with streptozotocin/nicotinamide induced pre-diabetes.

Hyperglycemia mediated oxidative stress and pro-angiogenic molecules such as vascular endothelial growth factor (VEGF) and matrix metalloproteinase 9 (MMP9) are considered important for diabetic retinopathy onset and progression. Melatonin is a pineal hormone that regulates circadian and seasonal rhythms and most likely is involved in regulating glucose metabolism. We aimed to evaluate the potential benefit of melatonin supplementation to the pre-diabetic retina by assessing melatonin effects on lipid peroxidation (thiobarbituric acid reactive substances, TBARS), protein oxidation (advanced oxidation protein products, AOPP) and concentrations of inducible nitric oxide synthase (iNOS), VEGF and MMP9 in the retina of rats with pre-diabetes. Pre-diabetes was induced by streptozotocin (45 mg/kg, i.p.) following nicotinamide injection (110 mg/kg, i.p.). Beside mild hyperglycemia, lower serum insulin, increased fructosamine and lower HDL cholesterol, the present study demonstrated decreased serum melatonin in pre-diabetic rats, as well as, increased concentration of retinal TBARS, AOPP, iNOS, VEGF, and MMP9. Oral supplementation with melatonin (85 µg/animal/day) caused melatonin and HDL cholesterol levels to rise in treated rats and reduced levels of fasting serum glucose and fructosamine. It also affected serum insulin and quantitative insulin sensitivity check index (QUICKI) in treated groups but had no significant effect on non-fasting glucose. Finally, supplementation with melatonin reduced concentrations of TBARS, AOPP, iNOS, VEGF, and MMP9 in significant level, thereby exerting an overall positive effect on oxidative stress and pro-angiogenic signaling in the pre-diabetic retina. Thus, oral melatonin might be considered in an early treatment or in the prevention of retinal changes associated with pre-diabetes.

Association of tumor necrosis factor-α (G-308A) genetic variant with matrix metalloproteinase-9 activity and joint destruction in early rheumatoid arthritis.

Matrix metalloproteinases (MMPs) are the key enzymes responsible for the joint destruction. Their activity is regulated by the level of proinflammatory cytokines. The aim of this study was to examine the impact of TNF-α G-308A polymorphism on MMP-9 levels in blood plasma (BP) and synovial fluid (SF) of patients with rheumatoid arthritis (RA) and their role in progression of joint destruction. One hundred thirty-four subjects were enrolled in this study. TNF-α G-308A polymorphism was determined using PCR-RFLP method. ELISA assay was used for the detection of MMP-9 activity in BP and SF. Joint damage was estimated by hands and feet radiography. Larsen score and annual changes in LS were used for quantitative evaluation of joint destruction and radiographic progression of disease. MMP-9 activity in BP and SF was significantly higher in RA compared to controls, as well as in SF of patients with erosive compared to nonerosive RA. Faster radiographic progression and increased MMP-9 activity in BP and SF were detected in the group A (GA or AA genotype carriers) compared to the group G (GG genotype carriers). However, statistical significance was revealed only for MMP-9 activity in SF (p < 0.05). MMP-9 activity in BP and SF is significantly higher in RA patients compared to patients with osteoarthritis. The presence of TNF-α-308A allele is associated with increased MMP-9 activity in SF of patients with early RA and may be a predictor of rapid radiographic progression of disease.

The Differences in the Cellular and Plasma Antioxidative Capacity Between Transient and Defined Focal Brain Ischemia: Does it Suggest Supporting Time-Dependent Neuroprotection Therapy?

There are many opened questions about the precocious role of oxidative stress in the physiopathology of the early stage of transitory ischemic attack (TIA) and defined focal brain ischemia, as well as about its correlation with clinical severity, short-lasting and clinical outcome prediction in these conditions. The study evaluates the values of glutathione (GSH), glutathione peroxidase, and superoxide dismutase (SOD) in hemolysates and total thiol content (-SH), advanced oxidation protein products (AOPP), SOD, and malondialdehyde (MDA) in plasma, in TIA and stroke patients in the early stage of their neurological onset. The results are interpreted in view of the potential relationship between tested parameters and clinical severity and clinical outcome prediction. Better hemolysates' and total antioxidant profile with higher values of AOPP were observed in TIA compared to stroke patients (p < 0.05). The stroke patients with initially better clinical presentation showed better antioxidant profile with lower values of AOPP (p < 0.05). In TIA patients, this was observed for GSH, -SH content, and AOPP (p < 0.05), which correlated with a short risk for stroke occurrence in this group (p < 0.01). Beyond MDA values, all tested parameters showed correlation with clinical outcome in stroke patients (p < 0.05). The measurement of oxidative stress in TIA and stroke patients would be important for identifying patients' subgroups which might receive supporting therapy providing better neurological recovery and clinical outcome. That approach might give us an additional view of a short-lasting risk of stroke occurrence after TIA, and its clinical outcome and prognosis.

Gene polymorphisms of tumor necrosis factor alpha and antioxidant enzymes in bronchial asthma.

BACKGROUND: Bronchial asthma is an inflammatory disease resulting from a combination of genetic and environmental factors. Single nucleotide polymorphisms in the regulatory regions of cytokine and antioxidant enzyme genes may affect cytokine production and enzyme activity, and thus play a contributory role in asthma pathogenesis. OBJECTIVES: The aim of this study was to examine the association of manganese superoxide dismutase (MnSOD) Ala16Val, catalase (CAT) A-21T and tumor necrosis factor alpha (TNF-α) G-308A polymorphisms with bronchial asthma. MATERIAL AND METHODS: A total of 79 patients with asthma and 95 healthy controls were screened for MnSOD Ala16Val, CAT A-21T and TNF-α G-308A polymorphisms using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. RESULTS: The results obtained showed significantly higher prevalence of the MnSOD ValVal genotype (χ2=14.463, df=2, p=0.001) and MnSOD 16Val allele (χ2=12.862, p=0.026, OR=0.451, 95% CI=0.291-0.699) in patients with asthma compared to controls. The genotype and allele frequencies distribution of CAT A-21T and TNF-α G-308A gene polymorphisms did not show differences between patients and controls. CONCLUSIONS: Our results show an association of MnSOD Ala16Val genetic polymorphism with asthma in a Serbian population and suggest a protective role of the MnSOD 16Ala allele.

Oxidative and Nitrosative Stress in Stable Renal Transplant Recipients with Respect to the Immunosuppression Protocol - Differences or Similarities?

BACKGROUND: The aim of the study was to evaluate parameters of oxidative and nitrosative stress as well as antioxidative parameters in a group of renal transplant recipients with stable graft function and no clinical signs of cardiovascular disease. We also aimed to determine the correlations among these parameters and to evaluate potential differences in all the biomarkers with regard to the immunosuppression protocol. METHODS: We enrolled 57 renal transplant recipients and 31 controls who were age and sex matched with the renal transplant recipients. All of the patients included in this study had post-renal transplant surgery at least 12 months earlier and were on standard immunosuppressive therapy. In this study, we determined thiobarbituric acid-reactive substances in plasma and red blood cells and advanced oxidation protein products, nitrosative stress parameters (asymmetric and symmetric dimethylarginine - ADMA and SDMA), and antioxidative parameters (total SH groups and catalase activity). RESULTS: The results of our study demonstrated that the levels of oxidative and nitrosative stress were significantly increased compared to the healthy population (p<0.01 except for plasma catalase activity p<0.05). Correlation analysis showed significant positive correlations between: ADMA and SDMA (p<0.01); ADMA and nitrates (p<0.05); SDMA and nitrates (p<0.05); between OS parameters in the experimental group; AOPP and SH groups (p<0.05) and TBARS in plasma and SH groups (p<0.01), SDMA and AOPP (p< 0.05); SDMA and TBARS in plasma (p<0.05); SDMA and SH groups (p<0.01); nitrates and SH groups (p<0.05). CONCLUSION: There was no significant difference in oxidative and nitrosative stress parameters with respect to the immunosuppressive protocol.

Glutathione homeostasis disruption of erythrocytes, but not glutathione peroxidase activity change, is closely accompanied with neurological and radiological scoring of acute CNS inflammation.

OBJECTIVES AND METHODS: The levels of glutathione (GSH) and glutathione peroxidase (GPx) activity were measured in the erythrocytes of 50 patients with clinically isolated syndrome of CNS (CIS) and 57 patients with relapsing remitting multiple sclerosis (RRMS). RESULTS: A decrease in GSH content and GPx activity showed significance in both study groups compared to the control values (p = 0.0025 and 0.007 for GSH and p = 0.005 and 0.003 for GPx, in CIS and RRMS patients, respectively). The depletions were more pronounced in RRMS than in CIS patients (p = 0.009 for GSH and p = 0.031 for GPx). The results significantly verify the negative correlations between GSH values and clinical severity (r = -0.513, p = 0.004), radiological findings (r = -0.351, p = 0.008) and disease duration (r = -0.412, p = 0.0025) in CIS patients. The same correlations were observed in RRMS patients between GSH values and clinical severity (r = -0.498, p = 0.004) and patients' radiological features (r = -0.454, p = 0.005). No correlations were observed between GSH values and other patient characteristics, or between GPx activity and all tested patient characteristics (p > 0.01). CONCLUSIONS: The results indicate that GSH content and GPx activity both decreased below the normal range and were accompanied with neuroinflammation, but although both might have great importance in neuroinflammation development, the data presented here confirm that only GSH might serve as a marker which is closely correlated with neurological and radiological scoring of acute CNS inflammation.

Crosstalk of inflammatory mediators and lipid parameters as early markers of renal dysfunction in stable renal transplant recipients with regard to immunosuppression.

BACKGROUND: Kidney transplantation is still the treatment of choice for end-stage renal disease, therefore it is important to establish all modifiable risk factors for initiation of renal dysfunction. MATERIAL/METHODS: We enrolled 73 renal transplant recipients, who were more than 12 months post-renal transplant surgery, had a stable graft function, had no clinically present cardiovascular disease, and were on standard immunosuppressive therapy. The concentrations of intracellular adhesion molecule-1 (ICAM-1), vascular adhesion molecule-1 (VCAM-1), CRP, lipids, and lipoproteins were measured. We used logistic regression to calculate non-adjusted, age, and multivariable-adjusted ORs and 95% confidence intervals for glomerular filtration rate, GFR <60 ml/min/1.73 m(2). RESULTS: Non-adjusted OR showed that there was a significant risk of reduced GFR in patients with total cholesterol higher than 5.19 mmol/L, LDL cholesterol ≥ 4.1 mmol/L, non- HDL ≥ 4.2 mmol/L, and higher VCAM-1 concentration. After adjustment for age and in multivariable model, OR showed a significant risk for reduced GFR in patients with total cholesterol ≥ 5.2 mmol/L, LDL ≥ 4.1 mmol/L, non-HDL ≥ 4.2 mmol/L, and higher VCAM-1 concentration. HDL, triglycerides, CRP, and lipoprotein ratios did not have any significance as predictors of renal dysfunction. There were no differences in all evaluated parameters between groups in regard to immunosuppressive therapy. CONCLUSIONS: Total cholesterol, LDL, non-HDL, and VCAM-1 are strong and independent predictors of renal dysfunction in stable renal transplant recipients. In contrast, HDL, CRP, triglycerides, and ICAM-1 did not seem to have any impact on renal dysfunction.

Suppression of the lipid peroxidation process in the CNS reduces neurological expression of experimentally induced autoimmune encephalomyelitis.

OBJECTIVE: Here we report the influence of malondialdehyde (MDA) as a measure of the lipid peroxidation process (LP), on multiple sclerosis (MS) pathogenesis and its neurological signs, during the treatment with aminoguanidine (AG) - a selective inducible nitric oxide synthase inhibitor and N-Acetyl cysteine (NAC) - an oxidative scavenger, in the experimental autoimmune encephalomyelitis (EAE), an animal model for studying MS. MATERIAL AND METHODS: Encephalomyelitis induction by the subcutaneous injection of myelin basic protein of bovine type, dissolved in phosphate buffered saline (PBS) emulsified in equal volume of the complete Freund's adjuvant (CFA), was described in detail in our earlier published papers. Each of animals was randomly assigned to seven groups - control (PBS), EAE, CFA, EAE + AG, AG, EAE + NAC and NAC group. In each animal, the development of neurological signs of EAE was scored, these results were published earlier. MDA was evaluated in the central nervous system (CNS) structure - cerebellums and spinal cords. RESULTS: The obtained results show that the AG and NAC treatment significantly reduces the MDA level in both examined tissues (p < 0.05) ameliorating at the same time EAE clinical signs (p < 0.05). CONCLUSIONS: Taking together our present and earlier findings we conclude that LP may provoke and promote MS, while blocking of this process results in amelioration of the clinical onset and disease activity. These results may be useful as a new insight into mechanisms and potential targets for therapeutic strategies in MS.

Tourniquet-induced ischemia-reperfusion injuries during extremity surgery at children's age: impact of anesthetic chemical structure.

OBJECTIVES: The aim of this study was to determine the relationship between the antioxidant profile of anesthetics and its relation to total antioxidant capacity (TAC) of plasma in children who underwent tourniquet-induced ischemia-reperfusion (IR) injury during extremity operations. METHODS: Children were randomized into three groups: general inhalational anesthesia with sevoflurane (group S), total intravenous anesthesia (TIVA) with propofol (group T), and regional anesthesia (group R). Venous blood samples were obtained before peripheral nerve block and induction of general anesthesia (baseline), 1 minute before tourniquet release (BTR), and 5 and 20 minutes after tourniquet release (ATR). Plasma TAC as well as antioxidant potential of propofol, thiopental, and bupivacaine were measured using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. RESULTS: Plasma TAC in group T was increased significantly at 20 minutes ATR in comparison with basal and BTR values, and also was significantly higher in comparison with plasma TAC in groups S and R measured at the same time point. The radical scavenging activity of anesthetics in vitro indicated that only propofol possessed a significant antioxidative activity in the reaction with DPPH radical in comparison with thiopental and bupivacaine. DISCUSSION: These data confirm that TIVA with propofol attenuates oxidative stress related to tourniquet-induced ischaemia-reperfusion injury in children.

Dexamethasone decreases the spermidine and spermine concentrations and polyamine oxidase activity in rat thymus.

BACKGROUND: Glucocorticoids (GCs) exert a wide range of anti-inflammatory, immunosuppressive, and antineoplastic activities. The aim of our investigation was to elucidate the effect of dexamethasone, a synthetic GC, on polyamine metabolism in the rat thymus. METHODS: Male albino Wistar rats, weighing 180-230 g, were divided into two groups: control and experimental. The experimental group received dexamethasone intraperitoneally for 3 days, in a daily dose of 4 mg/animal. The last dose of the hormone was applied on the 3rd day, 1 h before killing. The control group received 0.9% NaCl instead of the hormone. The animals were killed by decapitation. The thymus was removed quickly and rinsed with ice-cold saline. Polyamines were extracted using butanol. The amount of polyamines was investigated by electrophoresis. For the estimation of polyamine oxidase (PAO) activity, 10% water homogenate was prepared. RESULTS: Our results suggested that dexamethasone supplementation of experimental animals for 3 days significantly decreased the spermine (Sp) and spermidine (Spd) levels in rat thymus tissue (Sp Control, 362.56±25.33 nmol/g wet weight; Sp Exp. Group, 313.01±21.16 nmol/g wet weight; Spd Control, 673.81±30.95 nmol/g wet weight; Spd Exp. Group, 410.21±17.26 nmol/g wet weight). PAO activity significantly decreased under hormone influence in comparison with the control group (PAO Control, 0.449±0.121 U/mg prot.; PAO Exp. Group, 0.312±0.096 U/mg prot.). CONCLUSIONS: The decrease in polyamine amounts in the rat thymus is not due to the change in PAO activity.

Protective effects of glutathione and lipoic acid against cadmium-induced oxidative stress in rat's kidney.

Cadmium is a widespread, toxic industrial pollutant. The proximal tubule of the mammalian kidney is a major target of Cd-induced toxicity. We analyzed the effects of cadmium exposure on the model system of experimental animals, the thiobarbituric acid (TBA)-reactive substance (TBARS) level, and the activity of xanthine oxidase (XO) and catalase in kidney of rats, with and without glutathione and lipoic acid (LA). The experimental animals were classified into six groups, regarding cadmium, glutathione, and LA intake. The concentration of TBARSs in the homogenate was determined by spectrophotometric method according to Nabavi et al. The specific activity of XO was determined spectrophotometrically by the method of Aygul et al. Catalase activity in tissues was determined by spectrophotometric method according to Nabavi et al. The increased level of TBARS and the increased activity of XO in kidney tissue in cadmium poisoning are statistically significant compared to control (p < 0.001). Glutathione and LA applied along with cadmium lowered TBARS concentration and reduced XO activity (p < 0.001). Catalase activity in the kidney tissue was increased in the group, which was administered cadmium (p < 0.001). In conclusion, glutathione and LA, as physiological antioxidants applied with cadmium, have reduced the level of lipid peroxide and the activity of XO, and can be used as protectors in conditions of cadmium poisoning.

Modulation of nitric oxide synthase by arginase and methylated arginines during the acute phase of experimental multiple sclerosis.

We explore the nitric oxide synthase modulation by methylated arginines, asymmetric (ADMA) and symmetric (SDMA) dimethyl-l-arginine and arginase, in early phase of experimental autoimmune encephalomyelitis (EAE), the most frequently used animal model for studying the multiple sclerosis (MS), during the treatment with selective inducibile nitric oxide synthase inhibitor - aminoguanidine (AG) and oxidative scavenger N-acetyl-l-cysteine (NAC), compared to the clinical signs, continual to our previous research. The given results showed that the arginase activity was significantly increased in EAE rats compared to the healthy and AG treated EAE animals (p<0.05), and it was significantly decreased compared to the NAC treated EAE animals (p<0.05) in examined tissues. The ADMA and SDMA levels were significantly decreased in EAE untreated animals compared to the AG and NAC treated EAE animals (p<0.05). As we have reported in our previous papers, nitric oxide (NO) production, was significantly increased in examined tissues of EAE rats compared to the control group (p<0.05). In AG and NAC treated EAE group NO production was decreased in all tissues compared to untreated EAE animals (p<0.05). Also, the AG and NAC treatment of EAE rats during the development of the disease, significantly decreased the clinical score of EAE treated animals compared to EAE group. Arginase and methylated arginine derivatives, involving also NO, appear to be essential modulators of the inflammatory response in acute phase of MS. The continued research of these findings may provide a new area in the treatment of multiple sclerosis acute phase.

Correlation of nitric oxide levels in the cerebellum and spinal cord of experimental autoimmune encephalomyelitis rats with clinical symptoms.

Experimental autoimmune encephalomyelitis (EAE) is a well-established cell-mediated autoimmune inflammatory disease of the CNS, which has been used as a model of the human demyelinating disease. EAE is characterized by infiltration of the CNS by lymphocytes and mononuclear cells, microglial and astrocytic hypertrophy, and demyelination which cumulatively contribute to clinical expression of the disease. EAE was induced in female Sprague-Dawley rats, 3 months old (300 g ± 20 g), by immunization with myelin basic protein (MBP) in combination with Complete Freund's adjuvant (CFA). The animals were divided into 7 groups: control, EAE, CFA, EAE + aminoguanidine (AG), AG, EAE + N-acetyl-L-cysteine (NAC) and NAC. The animals were sacrificed 15 days after EAE induction, and the level of nitric oxide (NO(·)) production was determined by measuring nitrite and nitrate concentrations in 10% homogenate of cerebellum and spinal cord. Obtained results showed that the level of NO(·) was significantly increased in all examined tissues of the EAE rats compared to the control and CFA groups. Also, AG and NAC treatment decreased the level of NO(·) in all tissues compared to the EAE group. The level of NO(·) is increased significantly in the spinal cord compared to the cerebellum. The clinical course of the EAE was significantly decreased in the EAE groups treated with AG and NAC during the development of the disease compared to EAE group and its correlates with the NO(·) level in cerebellum and spinal cord. The findings of our work suggest that NO(·) and its derivatives play an important role in multiple sclerosis (MS). It may be the best target for new therapies in human demyelinating disease and recommend the new therapeutic approaches based on a decreased level of NO(·) during the course of MS.

Aminoguanidine and N-acetyl-cysteine supress oxidative and nitrosative stress in EAE rat brains.

Experimental autoimmune encephalomyelitis (EAE) is a well-established animal model of human multiple sclerosis (MS). We have evaluated the role of oxidative and nitrosative stress, as the causal factors in the development of EAE, responsible for the damage of cardinal cellular components, such as lipids, proteins and nucleic acids, resulting in demyelination, axonal damage, and neuronal death. EAE was induced in female Sprague-Dawley rats, 3 months old (300±20 g), by immunization with myelin basic protein in combination with Complete Freund's adjuvant (CFA). The animals were divided into seven groups: control, EAE, CFA, EAE+aminoguanidine (AG), AG, EAE+N-acetyl-L-cysteine (NAC) and NAC. The animals were sacrificed 15 days after EAE induction, and the levels of nitrosative and oxidative stress were determined in 10% homogenate of the whole encephalitic mass. In EAE rats, brain NO production and MDA level were significantly increased (P<0.001) compared to the control values, whereas AG and NAC treatment decreased both parameters in EAE rats compared to EAE group (P<0.001). Glutathione (GSH) was reduced (P<0.001) in EAE rats in comparison with the control and CFA groups, but increased in EAE+AG and EAE+NAC group compared to the EAE group (P<0.01). Superoxide dismutase (SOD) activity was significantly decreased (P<0.001) in the EAE group compared to all other experimental groups. The clinical expression of EAE was significantly decreased (P<0.05) in the EAE groups treated with AG and NAC compared to EAE rats, during disease development. The obtained results prove an important role of oxidative and nitrosative stress in the pathogenesis of EAE, whereas AG and NAC protective effects offer new possibilities for a modified combined approach in MS therapy.

[Association of TNF-alpha polymorphism (-308 A/G) with high activity of rheumatoid arthritis and therapy response to Etanercept].

INTRODUCTION: Genetic markers are significant predictive factors in the assessment of therapeutic response of rheumatoid arthritis (RA) to biological medication. OBJECTIVE: The aim of the study was to determinate the association of TNF-alpha -308 G/A polymorphism with a high RA activity and its predictive value in therapeutic response after 12 months of treatment with Etanercept. METHODS: The study enrolled 132 patients with RA treated with Methotrexate (MTX) and 58 control subjects. The -308 TNF polymorphism was examined using the polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP). The patients were divided into two groups: group A with A/A and A/G genotype and group G with G/G genotype. After 12 months, beside MTX, Etanercept was introduced in 36 patients. We compared clinical activity among the groups at the beginning and after one year of therapy by using DAS28 SE (Disease activity score with sedimentation). RESULTS: There was no significant difference found in the distribution of G and A allele in the RA group compared to the control group. A significantly higher disease activity was noticed in A compared to the G group (DAS28 SE: 6.31 to 5.81; p < 0.05). The patients with A allele kept the majority of the disease activity even after a year of study (DAS28 SE: 5.25 to 3.89). After a year of MTX and Etanercept therapy, a significantly larger proportion of patients in the G group displayed a good clinical response to treatment compared to the A group (81.5% to 25%; p < 0.05). The average change of DAS28 SE in G group was 2.24, while in the A group DAS 28 reduction was significantly lower (1.17; p = 0.005). CONCLUSION: There was no significant difference in the frequency of A in the patients with RA compared to healthy subjects. The presence of A allele is associated with more serious clinical presentation of the disease and lower therapeutic response to Etanercept.

The effects of different anesthesia techniques on free radical production after tourniquet-induced ischemia-reperfusion injury at children's age.

BACKGROUND/AIM: Reperfusion of previously ischemic tissue leads to injuries mediated by reactive oxygen species. The aim of the study was to investigate the effects of different anesthesia techniques on oxidative stress caused by tourniquet-induced ischemia-reperfusion (IR) injury during extremity operations at children's age. METHODS: The study included 45 patients American Society of Anesthesiologists (ASA) classification I or II, 8 to 17 years of age, undergoing orthopedic procedures that required bloodless limb surgery. The children were randomized into three groups of 15 patients each: general inhalational anesthesia with sevoflurane (group S), total intravenous anesthesia with propofol (group T) and regional anesthesia (group R). Venous blood samples were obtained at four time points: before peripheral nerve block and induction of general anesthesia (baseline), 1 min before tourniquet release (BTR), 5 and 20 min after tourniquet release (ATR). Postischemic reperfusion injury was estimated by measurement of concentration of malondialdehyde (MDA) in plasma and erythrocytes as well as catalase (CAT) activity. RESULTS: Plasma MDA concentration in the group S was significantly higher at 20 min ATR in comparison with the groups T and R (6.78 +/- 0.33 micromolL-1(-1) vs. 4.07 +/- 1.53 and 3.22 +/- 0.9. micromolL-1(-1), respectively). There was a significant difference in MDA concentration in erytrocythes between the groups S and T after 5 min of reperfusion (5.88 +/- 0.88 vs. 4.27 +/- 1.04 nmol/mlEr, p < 0.05). Although not statistically significant, CAT activity was slightly increased as compared to baseline in both groups S and R. In the group T, CAT activity decreased at all time points when compared with baseline, but the observed decrease was only statistically significant at BTR (34.70 +/- 9.27 vs. 39.69 +/- 12.91 UL-1, p < 0.05). CONCLUSION: Continuous propofol infusion and regional anesthesia techniques attenuate lipid peroxidation and IR injury connected with tourniquet application in pediatric extremity surgery.

Etanercept reduces matrix metalloproteinase-9 level in children with polyarticular juvenile idiopathic arthritis and TNF-alpha-308GG genotype.

Genetic contribution of tumor necrosis factor polymorphism (TNF-alpha-308G/A) in patients with juvenile idiopathic arthritis (JIA) on response to TNF blocking agents, as well as matrix metalloproteinase-9 (MMP-9) production, is not yet well established. We have investigated whether the TNF-alpha-308G/A polymorphism can influence MMP-9 level and clinical response to etanercept (TNF receptor II-Fc fusion protein) in JIA patients, after 1 year of treatment. A total of 66 patients with polyarticular JIA and 65 healthy children were screened for the polymorphism using the polymerase chain reaction-restriction fragment length polymorphism method. JIA patients donated paired blood samples prior to and 12 months after etanercept therapy. Plasma MMP-9 level was determined using an enzyme-linked immunosorbent assay kit. Clinical assessment was performed according to ACR Pedi 50 improvement criteria. The frequency of the A allele was significantly higher in JIA patients compared to controls (39% vs. 26%, P = 0.026). Patients with the -308GG genotype achieved an ACR Pedi 50 response significantly more frequently than those with the -308AA genotype (P = 0.035). MMP-9 level in patients with the genotype -308GG was significantly decreased after 1 year of treatment with etanercept compared to the value from before (P = 0.036). On the other hand, there was a decrease of MMP-9 levels after treatment, but not statistically significant in patients with the genotypes -308GA/AA. We conclude that etanercept reduces MMP-9 level in children with polyarticular JIA and TNF-alpha-308GG genotype. Our results correlate with findings that the -308A allele is associated with a lower response to etanercept treatment.