The influence of TNF alpha -308 G/A polymorphism on oxidative stress in patients with chronic lymphocytic leukemia.

The aim of this study was to examine the association of TNF-α-308G/A polymorphism with CLL and influence on oxidative stress parameters.Significant difference in the genotype and allele distribution was obtained in TNFA subgroup of patients.Significantly higher GPx activity and TBARS and lower catalase activity were detected in CLL.Significantly higher catalase and lower GPx activities were detected in PBMC of TNFG compared to TNFA subgroup, while TBARS were higher in TNFA.Oxidative stress in CLL patients highly correlates with the presence of TNFA subgroup. Increased TBARS, GPx and decreased catalase activity are associated with TNF-α-308A allele containing genotypes.

The Validation Study of Neurofilament Heavy Chain and 8-hydroxy-2'-deoxyguanosine as Plasma Biomarkers of Clinical/Paraclinical Activity in First and Relapsing-Remitting Demyelination Acute Attacks.

Although current evidence mainly suggests immunopathogenesis of demyelination and neurodegeneration in multiple sclerosis (MS), there are results which document the importance of other factors, such as oxidative stress and its mediated injuries. The oxidative stress intensity in axonal damage during acute demyelination is little known. We performed this study as a cross-sectional biomarker validation study in order to evaluate the parameters of axonal damage (phosphorylated neurofilaments heavy chain (pNF-H)) and oxidative stress (8-hydroxy-2'-deoxyguanosine (8-OHdG)) in plasma of patients with initial and relapsing-remitting demyelination attacks, defined as clinically isolated syndrome (CIS) and relapsing-remitting multiple sclerosis (RRMS); and the correlations between these parameters and biological (index of blood brain barrier (BBB) permeability), clinical (index of disease progression), and radiological (T1-Gd-enhancing lesion volume) activities of disease. Both parameters were increased in CIS and RRMS compared to control subjects (p < 0.05). The positive correlations were observed between 8-OHdG values and index of BBB permeability, clinical severity of disease, and demyelinated brain lesion volume, in CIS group (r > 0.50; p < 0.05). Similar correlations were obtained between pNF-H values and the above parameters, as well as the index of disease progression, in RRMS group (r > 0.30; p < 0.05). There was a significant correlation between values of 8-OHdG and pNF-H only in CIS group, r = 0.52, p < 0.05. While the plasma values of 8-OHdG reflect the degree of acute demyelination in CIS, pNF-H values reflect that in RRMS. The obtained results must be reevaluated in similar prospective studies related to their prognostic values.

The effect of melatonin on the liver of rats exposed to microwave radiation.

OBJECTIVES: We aimed to clarify if melatonin treatment (2 mg/kg i.p.) may favorably impact the liver tissue in rats exposed to microwave radiation. The experiment was performed on 84 six-weeks-old Wistar male rats exposed for 4h a day, for 20, 40 and 60 days, respectively, to microwaves (900 MHz, 100-300 microT, 54-160 V/m). Rats were divided in to four groups: I (control) - rats treated with saline, II (Mel) - rats treated with melatonin, III (MWs) - microwave exposed rats, IV (MWs + Mel) - MWs exposed rats treated with melatonin. We evaluated oxidative stress parameters (malondialdehyde and carbonyl group content), catalase, xanthine oxidase, deoxyribonuclease I and II activity. BACKGROUND: Oxidative stress is the key mechanism of the microwave induced tissue injury. Melatonin, a lipophilic indoleamine primarily synthesized and released from the pineal gland is a powerful antioxidant. RESULTS: Exposure to microwaves caused an increase in malondialdehyde after 40 (p < 0.01), protein carbonyl content after 20 (p < 0.05), catalase (p < 0.05) and xantine oxidase activity (p < 0.05) after 40 days. Increase in deoxyribonuclease I activity was observed after 60 days (p < 0.05), while deoxyribonuclease II activity was unaffected. Melatonin treatment led to malondialdehyde decrease after 40 days (p< 0.05), but surprisingly had no effect on other analyzed parameters. CONCLUSION: Melatonin exerts certain antioxidant effects in the liver of rats exposed to microwaves, by diminishing the intensity of lipid peroxidation(Fig. 6, Ref. 32).

The Role of Matrix Metalloproteinase 3 and 9 in the Pathogenesis of Acute Neuroinflammation. Implications for Disease Modifying Therapy.

Matrix metalloproteinases (MMPs) are proteolytic enzymes that are involved in a variety of physiological and pathological processes, including those in CNS. In this study, plasma values of MMP-3 and MMP-9 have been compared in clinically isolated syndrome (CIS) and relapsing-remitting multiple sclerosis (RRMS) patients during their acute attacks, in relation to the biological activity of disease. Therefore, we compared the MMPs plasma values regarding Expanded Disability Status Scale (EDSS), progression index of disease (PID), acute brain lesion volume seen on magnetic resonance imaging (MRI) and index of blood-brain barrier (BBB) permeability destruction. The obtained results demonstrated higher plasma values of MMPs in both study groups than control values (p < 0.05). No statistical significances have been detected comparing the obtained values of both enzymes between CIS and RRMS group (p > 0.05). In both CIS and RRMS groups, the patients with higher EDSS showed higher MMPs plasma values (p < 0.05). The MMPs values were also significantly higher in both study patients with higher total number comparing to those with lower number of MRI brain lesion (p < 0.05) (beyond MMP-3 in RRMS). All obtained correlations, between MMPs and EDSS, PID, volume of MRI Gd-enhancement brain lesions, and index of BBB permeability, were positive (p < 0.05.) This study demonstrates alterations of both tested MMPs with closed correlation with the disease biological activity. Although MMPs are being implicated in the pathogenesis of acute neuroinflammation, the MMPs modulation might be useful in the future design of disease modifying therapy with the specific target profile.

Biomarkers of oxidative stress and endothelial dysfunction after tourniquet release in children.

Pneumatic tourniquets are widely used in pediatric extremity surgery to provide a bloodless field and facilitate dissection. This prospective study was carried out to examine possible effect of different anesthesia techniques on oxidative stress and endothelial dysfunction connected with ischemia-reperfusion injury during extremity operations at children's age. Patients 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 for determination of the malondialdehyde in plasma and erythrocytes, protein carbonyl groups concentration as well as plasma nitrites and nitrates level and xanthine oxidase activity were obtained at four time points: before peripheral nerve block and induction of general anesthesia (baseline), 1 min before tourniquet release, 5 and 20 min after tourniquet release. This study demonstrates that total intravenous anesthesia with propofol and regional anesthesia techniques provide better antioxidant defense and reduce endothelial dysfunction than general inhalational anesthesia with sevoflurane during tourniquet application in pediatric extremity surgery.

Hyperglycemia, oxidative and nitrosative stress affect antiviral, inflammatory and apoptotic signaling of cultured thymocytes.

A high prevalence of various infectious diseases is reported in diabetic patients, which may suggest impaired innate immunity against different pathogen-associated molecular patterns. This study investigated the effects of hyperglycemia, oxidative stress (H(2)O(2)), nitric oxide (NO) and peroxynitrite (ONOO(-)) on the modulation of antiviral (MDA-5, IRF-3 and phospho-IRF-3), inflammatory (NF-kappaB) and pro/anti-apoptotic molecules (Bax and Bcl-2) in BALB/c mice thymocytes. Each of the experimental conditions, except the weakest NO concentration, resulted in down-regulation of MDA-5, IRF-3 and phospho-IRF-3. In contrast, each of the experimental conditions elicited up-regulation of NF-kappaB, Bcl-2 and Bax. These results suggest that hyperglycemia, oxidative and nitrosative stress may contribute to the reduced immunity of the host by altering the MDA-5/IRF-3/phosphoIRF-3 axis, as well as contributing to the mechanisms of inflammatory reaction via increased NF-kappaB, and to augmented turnover rate of thymocyte cells via Bcl2/Bax up-regulation.

Possible effects of interferon-alpha on Fas-induced renal apoptosis in mouse.

UNLABELLED: Fas (APO-1/CD95) is a cell surface receptor that initiates apoptotic pathway. Fas-stimulated ROS generation may play important role in Fas-mediated apoptosis. The aim of this study was to evaluate the influence of interferon-alpha on oxidative stress parameters in Fas-induced renal apoptosis in mice kidney. SUBJECTS AND METHODS: One-month-old Balb C male mice were used for the study. The animals were divided in four groups: group 1 were the controls, group 2 mice were treated with anti-Fas antibody i.p., group 3 mice were treated with IFN-alpha, and group 4 mice were treated with both agents simultaneously. The mice were killed 48 h afterwards, and kidneys were homogenized. TBA reactive substances (TBARS), glutathione content, and reactive carbonyl group (RCG) were measured. RESULTS: The results showed a statistically significant increase of TBARS (p < 0.05) and RCG (p < 0.05) concentration in the group treated with anti-Fas antibody versus control. IFN-alpha decreased the concentration of TBARS and RCG after anti-Fas antibody administration (p < 0.05). There is no significant difference in glutathione content between investigated groups. CONCLUSION: IFN-alpha might be considered as a new target for therapeutic intervention in FasL/Fas induced renal injury.

Possible impact of impaired double-stranded RNA degradation and nitrosative stress on immuno-inflammatory cascade in type 2 diabetes.

The immune response can be triggered by molecules derived from microorganisms (PAMP) or from molecules derived from damaged or dead host cells, known as the damage-associated molecular-pattern molecules (DAMP). Their immune effects are accompanied by altered redox environment. The level of stable end products of nitric oxide (NO)- plasma nitrate and nitrite (NOx), carbonyl groups (PCO) and nitrotyrosine (NTY), in relation to the metabolism of dsRNAs (poly I:C and poly A:U) and xanthine oxidase (XO activity), in plasma of type2 diabetic patients was determined. Thirty-six patients with type 2 diabetes (age group 34-66 years, 19 male and 17 female) were allocated to the study. Diabetic patients had a significantly higher level of plasma NOx products, NTY and PCO, fructosamine (FA) and XO activity indicating about altered redox environment. The concentration of circulating ribonucleic acids (CNAs) was significantly higher in type 2 diabetic patients, which was accompanied by a significantly decreased activity of RNase against double stranded RNA forms (poly I:C and poly A:U), compared to control samples. To determine whether CNAs, as possible DAMP molecules, are capable of exerting effect on inflammatory and host antiviral response, the effect of isolated CNAs on NF-kappaB, Bcl-2, Bax, MDA-5 and IRF-3 regulation was evaluated in culture of fresh isolated thymocytes. Circulating nucleic acids isolated from type 2 diabetic patients were able to upregulate NF-kappaB more than control RNA samples. In the same experimental conditions the mild Bcl-2 upregulation, followed by the marked Bax upregulation, was demonstrated. Since the Bcl-2/Bax ratio was lower in type 2 diabetic samples, obtained results may implicate that CNAs may exert proapoptotic response in type 2 diabetes. The CNAs isolated from diabetic patients were able to downregulate MDA-5 and IRF-3, very important subjects of the surveillance and cellular anti-viral response. The major findings of the present study are that impaired dsRNA metabolism may lead to increased level of different sized RNAs in type 2 diabetic patients. Acting as possible DAMP molecules, they may contribute to higher susceptibility of immune cells to inflammatory cascade via NF-kappaB activation, and possible MDA-5/IRF-3 axis downregulation, what may have an influence on further ineffective response against different pathogens.

Arginase activity and magnesium levels in blood of children with diabetes mellitus.

Under physiological conditions insulin controls the metabolism of carbohydrates, lipids and proteins. Diabetes mellitus is a metabolic disease characterized by a disturbance in the intermediary metabolism of glucose and glucose-induced insulin release. Arginase (L-arginine amidinohydrolase, EC 3.5.3.1) modulates nitric oxide synthase activity by regulating intracellular L-arginine availability. In diabetes mellitus, a decrease in nitric oxide bioavailability is a central mechanism for endothelial dysfunction. The aim of our study was to assess arginase activity in the blood of children with diabetes mellitus. Blood arginase activity, serum glucose (14.155 +/- 4.197 mmol/L; p < .001) and blood HbA1c (11.222 +/- 3.186 %; p < .001), were significantly higher in diabetic children than in healthy controls, whereas the magnesium (Mg2+) level, a cofactor of many enzymes, was significantly lower (0.681 +/- 0.104 micromol; p < .001). In diabetic children, arginase activity, hyperglycemia (r = 0.143), and the HbA1, level (r = 0.381) showed a positive correlation between but a negative correlation between Mg2+ and arginase activity (r= -0.206). The higher arginase activity and the lower Mg2+' levels in diabetic children could be a consequence of reduced insulin action and increased protein catabolic processes in these pathophysiological conditions. The inverse directions of arginase activity and serum Mg2+ levels are in agreement with this concept.

Microalbuminuria in children with vesicoureteral reflux.

Vesicoureteral reflux (VUR) is a common congenital anomaly of the urinary tract that may be inherited. Reflux of infected urine may cause scarring in susceptible kidneys with the potential to compromise renal function. The aim of the study was to evaluate the possible influence of different grades of VUR on glomerular damage using microalbuminuria as a parameter. Children with VUR detected by voiding cystourethrography (VCUG) were investigated. According to the grade of VUR, patients were separated into three groups. The first group included 12 children with VUR grade I-II. The second group consisted of 12 children with grade III of VUR. Patients with VUR grade IV-V (n = 11) were members of the third group. The control group consisted of 17 healthy children. Microalbuminuria was examined in samples of morning urine specimens using a microalbumin/creatinine reagent kit. Serum urea, creatinine levels and creatinine clearance (CCR) were measured as markers of renal function. The mean value of microalbumin excretion in the third group showed a statistically significant increase (p < 0.001) compared to all other groups. CCR in the third group was statistically significantly decreased (p < 0.05) in comparison to the group of healthy children. There were no statistically significant changes of microalbumin excretion and CCR in the first and second group compared to control values. We discussed the presence of microalbuminuria and decrease of CCR in children with high grade of VUR as a possible consequence of retrograde urine flow (intrarenal reflux), glomerulosclerosis, and consecutive hyperfiltration.

Glucocorticoids and oxidative stress.

Glucocorticoids (GC) are used widely for the treatment of patients with various disorders, including autoimmune diseases, allergies, and lymphoproliferative disorders. Glucocorticoid therapy is often limited by several adverse reactions associated with GC excess. Excess GC can elicit a variety of symptoms and signs, including growth retardation in children; immunosuppression; cardiovascular disorders like hypertension and atherosclerosis; osteoporosis; myopathy; and diabetes mellitus. Currently, attention is focused on oxidative stress as one of the major determinants of endothelial dysfunction and cardiovascular senescence. The main reason for all unwanted effects of GC is that dexamethasone induces the overproduction of reactive oxygen species, causing dysregulation of physiological processes. Humans and animals with GC-induced hypertension exhibit reduced nitric oxide levels; patients with excess GC levels also suffer from depression as a consequence of low levels of serotonin and melatonin. The common cofactor for the production of these vasoactive molecules is tetrahydrobiopterin (BH4), which is required for nitric oxide synthesis.

Selenomethionine induces polyamine biosynthesis in regenerating rat liver tissue.

Our study was undertaken to elucidate the effects of selenomethionine (SeMet) on polyamine metabolism in regenerating rat liver tissue, as useful model of rapidly growing normal tissue. We have examined the levels of spermine, spermidine and putrescine in liver tissue. At the same time we have evaluated the activities of polyamine oxidase (PAO) and diamine oxidase (DAO), the catabolic enzymes of polyamine metabolism. The obtained results suggest that polyamine levels in regenerating liver tissue, at 7(th) day after two-thirds partial hepatectomy, were higher in comparison with control group. The administration of selenomethionine to hepatectomized animals during seven days, in a single daily dose of 2.5 microg/100 g body weight, increases the amount of spermine and spermidine; the level of putrescine does not change under the influence of SeMet in regenerating rat liver tissue.PAO activity is lower in regenerating hepatic tissue than in control group. Supplementation of hepatectomized animals with SeMet significantly decreases the activity of this enzyme. DAO activity was significantly higher in hepatectomized and in operated animals treated with SeMet compared to the sham-operated and control ones. The differential sensitivity observed in our model of highly proliferating normal tissue to SeMet, compared with the reported anticancer activity of this molecule is discussed.