Biomedical subjects

Anna Blázovics

Publications and source records attributed to Anna Blázovics.

At least 19 recordsLinked to original sources

PubMed2007

Effects of vitamin E administration on the hemorheological status and redox homeostasis of patients with porphyria cutanea tarda treated with phlebotomy.

BACKGROUND: Conflicting results were reported about the efficacy of vitamin E (E) treatment in porphyria cutanea tarda (PCT). We conducted a study in PCT patients to investigate whether E treatment has any additional beneficial effects compared with phlebotomy (P) treatment alone on rheological and oxidative stress parameters. METHODS: Twenty three patients with sporadic PCT in clinical remission and 10 healthy control patients were studied. All patients were treated with P prior to the study until clinical remission was achieved. Baseline routine laboratory [blood glucose, serum lipids, C-reactive protein (CRP), iron metabolism indices, liver function tests], oxidative stress [serum thiobarbituric acid reactive substances (TBARS), plasma H-donor activity, plasma free SH-groups, erythrocyte glutathion peroxidase activity] and rheological parameters (whole blood and plasma viscosity, cell transit time, clogging rate) were measured in both groups. Then all PCT patients received E (tocopherol acetate) 200 mg/day for 8 weeks and at the end of treatment measurements identical to those performed at baseline were repeated. RESULTS: Increased urine uroporphyrin, serum CRP, TBARS concentrations, whole blood and plasma viscosity and decreased plasma H-donor activity, free SH-group level, erythrocyte glutathione peroxidase activity were detected in PCT patients treated with P alone compared with control group consistent with residual oxidative stress in PCT patients. E treatment decreased urine uroporphyrin and serum TBARS concentrations; increased plasma H-donor activity and did not influence whole blood and plasma viscosity compared with P treatment alone. CONCLUSIONS: E treatment reduced the residual oxidative stress and did not influence increased plasma and whole blood viscosity present in PCT patients receiving P treatment prior to clinical remission.

Adult↗

PubMed2006

Reduced antioxidant level and increased oxidative damage in intact liver lobes during ischaemia-reperfusion.

AIM: To determine whether increased blood flow of the liver can cause oxidative stress and hepatocyte damage, and to elaborate methods suitable for measuring the antioxidant defence during hepatic surgery on rat model. METHODS: In nembutal narcosis, the left lateral and the medial lobes of the liver were clipped for 45 min to make the total blood supply flow through the other lobes. Total antioxidant status, glutathione peroxidase and superoxide dysmutase activity, as well as the concentrations of diene conjugates and free sulphydril groups, H-donating ability and reducing power of the liver samples were determined. Chemiluminescent intensity of the liver was also measured. Metal ions (Al, Ca, Cu, Fe, Mg, Mn, Zn) and P and S concentrations of the liver were determined with an inductively coupled plasma optical emission spectrometer and Se content was measured by cathodic stripping voltammetry. RESULTS: Glutathione peroxidase and superoxide dysmutase activities of the liver decreased significantly in the hyperemia group compared to those observed in the sham operated group. The level of total antioxidant status was also significantly lower in the hyperemia group. H-donating ability, reducing power and free sulphydril group concentration showed the same tendency. A significant correlation (P<0.05) was found between the changes in non-specific antioxidant activities. This pointed to simultaneous activity of the antioxidant defence system. Al, Cu, Mn, Zn, and S were lower in the hyperemia group than in the sham operated group when the levels of Ca, Fe, Mg, Se and P ions were higher during hyperemia. CONCLUSION: Oxidative stress is one of the main factors for the injury of intact liver lobes during ischaemia-reperfusion.

Analysis of Variance↗

PubMed2006

Metal ion and antioxidant alterations in leaves between different sexes of Ginkgo biloba L.

A comparative study was carried out to determine some valuable phytochemical components, macro- and microelement and redox parameters in leaves of male and female Ginkgo biloba trees and in extracts made from them. G. biloba extracts have become more popular as a therapeutic agent in the modern pharmacology in neurodegenerative diseases, in which increased brain metal levels can be observed and free radical reactions are involved. Macro- and microelement components, total phenol content, H-donating activity and reducing power as well as total scavenger capacity were determined in the samples. Well detectable differences were obtained for micro- and macroelement contents between male and female samples, but no toxic elements could be detected in the extracts. Male extracts contained more hazardous metals (e.g. Fe) compared to the female ones, while extracts from female leaves had higher levels of ions, which are known to have beneficial effects in neurodegenerative diseases. The ethanolic extracts of male leaves showed the highest H-donating activity, reducing power and total phenol content, as well as the best total scavenger activity. Ginkgo extracts due to the antioxidant properties may have favourable effects as dietary supplements in several neurodegenerative diseases, but this study draws the attention that critical evaluation is required in view of the potential hazard induced by their metal ion constitution. Our results lead us to the conclusion that although the aqueous extracts of female leaves are characterized by relatively lower antioxidant properties, they may be more eligible for these purposes due to their favourable metal ion constitution.

Antioxidants↗

PubMed2006

Hemorheological status and redox homeostasis of phlebotomised porphyria cutanea tarda patients with diabetes mellitus and in moderate alcohol consumer.

Increase in porphyrin concentration is caused by the decreased activity of uroporphyrinogen decarboxylase in porphyria cutanea tarda (PCT). Iron overload, alcohol consumption and diabetes mellitus play role in the development of PCT. We investigated the hemorheological and redox-parameters from the blood of 34 male PCT patients and 10 male volunteers. The disfunctions were investigated by pathological amounts of iron and lipid metabolism. Routine laboratory and hemorheological parameters, plasma free SH-group concentration, H-donating ability and reducing power were measured by spectrophotometry. Free radical activity was determined by chemiluminometry method. The hemorheological parameters were significantly increased in all three groups of PCT patients compared to the controls. Negative correlations were observed between blood viscosity and antioxidant defence of PCT patients and in PCT patients with alcohol consumption. Plasma and erythrocyte chemiluminescent intensity was higher in PCT patients than in controls, which indicated the decrease of antioxidant defence. Hemorheological parameters were highest in patients with diabetes and in alcohol consumers. Iron overload increased free radical reactions in PCT patients, leading to pathological viscosity. Increased free radical reactions and high blood viscosity increase the risk of cardiovascular diseases.

Alcohol Drinking↗

PubMed2005

[The therapeutic effect of metadoxine on alcoholic and non-alcoholic steatohepatitis].

The therapeutic effect of metadoxine on alcoholic and non-alcoholic steatohepatitis. Alcohol-induced liver disease is one of the main epidemic problems of nowadays. Non-alcoholic steatohepatitis has been described only for some years, but it also needs much more attention in the future. The etiologic factors of both entities are quite different, but the pathologic changes of the liver are nearly the same, therefore there could be certain drugs, that are equally effective in their therapy. Metadoxine is one of them, mainly because its protective effect against the damage done by free radicals. Metadoxine is a pyridoxine-pyrrolidone carboxylate with significant scavenging property. There are a lot of patients suffering from steatohepatitis, and they will face the complications of the liver damage. The aim is to provide better recovery and proper quality of life, which is based on the deeper understanding of these mechanisms. Metadoxine is suitable for increasing reduced glutathione level, which is very important for the redox homeostasis of the liver and the whole body. The effectiveness of the drug is established both in acute and in chronic alcoholism, moreover it helps in staying abstinent.

Alcohol Deterrents↗

PubMed2005

Insulin treatment decreases the antioxidant defense mechanism in experimental diabetes.

BACKGROUND: Hyperglycemia-induced oxidative stress and left ventricular hypertrophy is an independent risk factor for cardiovascular disease. Our aim was to determine the relationship between left ventricular hypertrophy and the total scavenger capacity (TSC) in diabetic rats. MATERIAL/METHODS: Control animals (n=30) were compared to streptozotocin-induced diabetic rats (n=38) and diabe-tic rats receiving insulin treatment (n=30) for 22 days. Half of the animals received angiotensin II on day 21. The left ventricular mass, TSC and carbohydrate parameters were determined. RESULTS: Diabetes did not alter left ventricular mass; however, diabetes with insulin treatment was associated with left ventricular hypertrophy. The extent of ventricular hypertrophy did not change significantly in this group after angiotensin II treatment. TSC increased very significantly in diabetic rats. These differences remained high when angiotensin II-treated control rats [CA] were compared with treated diabetic rats [DA] (p<0.005). TSC decreased significantly when diabetic rats were treated with insulin. CONCLUSIONS: Diabetes results in oxidative stress, which in turn enhances the activity of antioxidant enzymes. This increase in enzyme activity inhibits the subcellular remodeling processes, thus also inhibiting concomitant cardiac hypertrophy. Insulin treatment decreases the activity of the antioxidant system and can enhance the function of other localized tissue-specific growth factors. These changes may contribute to the early onset of cardiovascular damage detected in diabetic patients.

Angiotensin II↗

PubMed2005

Poly(ADP-ribose) polymerase inhibitor PJ-34 reduces mesenteric vascular injury induced by experimental cardiopulmonary bypass with cardiac arrest.

The aim of this study was to investigate effects of poly(ADP-ribose) polymerase (PARP) inhibition on mesenteric vascular function and metabolism in an experimental model of cardiopulmonary bypass (CPB) with cardiac arrest. Twelve anesthetized dogs underwent 90-min hypothermic CPB. After 60 min of cardiac arrest, reperfusion was started for 40 min following application of either saline vehicle (control, n = 6) or a potent PARP inhibitor, PJ-34 (10 mg/kg iv bolus and 0.5 mg.kg(-1).min(-1) infusion for 20 min, n = 6). PJ-34 led to better recovery of cardiac output (2.2 +/- 0.1 vs. 1.8 +/- 0.2 l/min in control) and mesenteric blood flow (175 +/- 38 vs. 83 +/- 4 ml/min, P < 0.05 vs. control) after reperfusion. The impaired vasodilator response of the superior mesenteric artery to acetylcholine, assessed in the control group after CPB (-32.8 +/- 3.3 vs. -57.6 +/- 6.6% at baseline, P < 0.05), was improved by PJ-34 (-50.3 +/- 3.6 vs. -54.3 +/- 4.1% at baseline, P < 0.05 vs. control). Although plasma nitrate/nitrite concentrations were not significantly different between groups, mesenteric nitric oxide synthase activity was increased in the PJ-34 group (P < 0.05). Moreover, the treated group showed a marked attenuation of mesenteric venous plasma myeloperoxidase levels after CPB compared with the control group (75 +/- 1 vs. 135 +/- 9 ng/ml, P < 0.05). Pharmacological PARP inhibition protects against development of post-CPB mesenteric vascular dysfunction by improving hemodynamics, restoring nitric oxide production, and reducing neutrophil adhesion.

Animals↗

PubMed2005

Antioxidant effect of squeezed juice from black radish (Raphanus sativus L. var niger) in alimentary hyperlipidaemia in rats.

Black radish (Raphanus sativus L. var. niger) root has been used in folk medicine since antiquity as a natural drug for the stimulation of bile function. According to in vitro studies the squeezed juice from black radish root exhibited significant antioxidant properties. In the present study, the beneficial effect of the black radish juice on some free radical reactions in rats fed with a diet rich in lipids (20% sunflower oil, 2% cholesterol, 0.5% cholic acid in normal chow) was examined. Thiobarbituric acid reactive substances and conjugated diene concentrations were significantly higher, while the antioxidant enzyme activities and the free radical scavenging capacity were lower in hyperlipidaemic rats compared with normal controls. Supplementation of the lipid-rich diet with black radish juice resulted in a significant improvement of the parameters mentioned above. Although the exact mechanism of the biologically active compounds in black radish on the lipid metabolism and lipid peroxidation is not clear yet, a beneficial effect of the drug was evident in alimentary hyperlipidaemia.

Animals↗

PubMed2005

Mesenteric vascular dysfunction after cardiopulmonary bypass with cardiac arrest is aggravated by coexistent heart failure.

Although patients suffering from heart failure (HF) have an increased incidence of nonocclusive mesenteric ischemia after opened heart surgery, the impact of cardiopulmonary bypass with cardiac arrest (CPB) on mesenteric vascular circulation in such situation remains unexplored. Therefore, the present study investigates the effects of CPB on mesenteric vascular reactivity, regional metabolism, and oxidative stress in an experimental model of HF. Volume-overload HF was induced in six dogs by bilateral femoral arteriovenous fistula. Six sham-operated dogs were used as controls. Eight weeks later, the short-term effects of 90 min of CPB were assessed in vivo during acute experiments. The significant increase in left ventricular end-diastolic volume in HF animals did not influence the vasodilator response of the superior mesenteric artery to acetylcholine (ACH) and nitroprusside (SNP) under baseline conditions. However, reduced mesenteric oxygen delivery, increased oxygen extraction, and lactate release were found during CPB in the HF group. In addition, an increased free radical production was assessed in the HF group during (89 +/- 23 x 10 relative light units [RLU]) and after CPB (93 +/- 15 x 10 RLU) compared with controls (45 +/- 15 and 49 +/- 7 x 10 RLU, respectively). Finally, 90 min of CPB led to a more pronounced decrease of ACH- (-22% +/- 5% vs. -42% +/- 9%, P < 0.05) and SNP- (-14% +/- 4% vs. -50% +/- 7%, P < 0.002) induced mesenteric vasodilations in the HF group compared with controls. We conclude that coexistent HF significantly enhances the pathological effects of CPB on the mesenteric vascular circulation by additionally altering endothelial and smooth muscle vascular function consequent to augmented oxidative stress.

Acetylcholine↗

PubMed2004

[Cytokines, prostaglandins, nutritive and non-nuitritive factors in inflammatory bowel diseases].

Therapeutic interventions in the case of gastrointestinal disease are based on the understanding of the role of different inflammatory mediators. Reactive O2 and N2 metabolites are involved in IBD. Pro-inflammatory cytokines, apoptosis signalling and redox-response transcription factors are depended on free radicals. NO activates COX enzymes. PGE2 negatively modulates induction of NO synthase by interleukins and therefore regulation of gastric mucosal integrity by endogenous NO depends on arachidonic acid cascade. PG-s have pro-inflammatory and anti-inflammatory effects on the immune system. Dietary PUFA-s and eicosanoids have potential effects on the modulation of inflammatory processes and immune cells. The cholesterol level lowering activity of several cytokines and colony stimulating factor can be observed. Therapeutic efficacy of N-3 PUFA is described in cases of patients with chronic gastrointestinal disorders, but N-3 PUFA-s only delay early relapse of ulcerative colitis in remission. TNF is known as a pleiotropic cytokine. Strategies for TNF in IBD is very important part of therapeutical approaches. Therapy with infliximab and related ones are encouraging in critical cases. It is also believed recently, that NF-kappaB also may be a target of IBD treatment. It became known, that oxidized LDL can inhibit LPS-induced binding of the NF-kappaB to DNA and the subsequent expression of TNF-alpha and interleukin-1beta in macrophages as well as oxidized LDL modulates activation of NF-kappaB in mononuclear phagocytes by altering the degradation of I-kappaBs. 15-d-PGJ2 inhibits multiple steps in the NF-kappaB signaling pathway. 15-d-PGJ2 metabolite binds PPAR-gamma promotes adipocyte differentiation. PPAR-gamma ligand inhibits growth of cells through induction of apoptosis. Several nutritional polyphenols (the secondary metabolites of plants) are COX2 and/or LOX inhibitors and iNOS activators. The moderate nutritional customs with natural antioxidants can help restore to normal function of gastrointestinal tract, but the immoderate consumption of vitamins and polyphenol type antioxidant molecules is contraindicated.

Antibodies, Monoclonal↗

PubMed2004

[Oxidative stress and liver disease].

Several papers have been published on the important role of oxidative stress on living cells and cell responses e.g. apoptosis and necrosis, which leads to cell death. At the same time mild oxidative stress can modulate signal transduction cascades and redirect gene expression, and influence many cellular responses, e.g. proliferation, differentiation, reproduction. Regulations of the cell cycle depend on intracellular redox state. Critical steps in the signal transduction cascade are sensitive to oxidative stress and antioxidants. Heavy metal accumulation in higher concentration may inhibit enzyme activities influence the acute phase protein synthesis and gene expression, as well as the pro-oxidant and antioxidant forms of scavenger molecules. Polyphenols and flavonoid type antioxidants may influence the signal transduction routes as well. Ethanol inducible cytochrome P450 2EI isoenzyme oxidise ethanol and acetaldehyde and numerous potentially toxic xenobiotic and produce toxic oxygen free radicals, which are implicated in the pathogenesis of alcoholic liver diseases. Natural preparations, e.g. tea infusions contains trace elements and polyphenol type antioxidants in high concentration, therefore may influence the redox homeostasis, and especially dangerous with interaction of other medicines and alcohol.

Animals↗

PubMed2004

[Redox homeostasis in inflammatory bowel diseases].

Janus faced oxygen radicals are secondary messengers of intracellular signal transduction pathways but also cytotoxic agents of cells. Activation of signal transduction proteins on mild oxidant stress and metal elements are still not clearly understood. Oxygen free radicals may have several functions in the expression of cytokines associated with inflammatory bowel disease. The molecular mechanism between activation, and inhibition participants of signal transduction are delicately controlled. Antioxidant-prooxidant balance of the cells can be traced back to the concentration of free-SH and its oxidised form,-S-S-. Healthy erythrocytes and plasma are rich in antioxidants, but their type of protection, differs significantly. The balance of free radicals and antioxidants is disturbed in inflammatory bowel disease. The antioxidant defence mechanism depends on concentration of metal elements, which determines enzyme activities. It seems that nutritional supplementation and adequate therapy restore the ion homeostasis, although, Zn overdose may cause disturbance in iron metabolism and consequently may influence erythrocyte functions.

Antioxidants↗

PubMed2004

[Antioxidants in liver protection].

Great importance has been attributed to antioxidants in the prevention and treatment of conditions associated with oxidative stress for many years. At the same time the antioxidants are free radicals themselves, and they can exert prooxidant activity depending on the concentration. They influence the cell redox homeostasis by their prooxidant and antioxidant activity as well. Drugs of chronic liver diseases should be considered, because free radicals are generated during the activity of the monooxygenase system, which affect the tissue oxidised status. Combined antioxidant treatment is more favourable compared with monotherapy, because antioxidants have scavenger-, compartment- and tissue-specificity and they regenerate each other directly, too. Beside their antioxidant property they may also directly regulate many important processes, e.g. cell cycle. We have some favourable results with regard combined antioxidant therapy of liver disease of different etiology.

Antioxidants↗

PubMed2004

[Methods of monitoring oxidation-reduction balance and its potential role in diagnostics].

Results of the latest investigations confirm that the injury of redox homeostasis of human organism can be the starting point of many diseases. The pathogenesis of these diseases, including atherosclerosis, diabetes mellitus, chronic liver diseases, renal failure, rheumatoid arthritis and neurodegenerative diseases could be cleared up more deeply by the investigation of parameters of oxidative stress and by the observation of their changes in connection with the different organ and tissue damages. It is well known, that individuals with lowered antioxidant defences may be at greater risk of developing diseases induced by free radicals. The goal of the authors is to direct attention to the possible role of some redox parameters in detecting of general health status of the human body and in the risk assessment of the different diseases. These measurements can perhaps help the clinician in determining optimal treatment and monitoring its effectiveness.

Antioxidants↗

PubMed2004

Special wound healing methods used in ancient egypt and the mythological background.

The Egyptian civilisation is one of the oldest in history and was renowned for its scientific and artistic achievements, and medicine was no exception. The ancient Egyptians were masters in applying and arranging bandages, and they recognized the cardinal signs of infection and inflammation. Egyptian drug therapy can be regarded as having evolved from a system rooted in magic and empirical observation. To illustrate how the Egyptian wound healing methods provided a major stimulus for the development of surgery, we conducted a literature search.

Bandages↗

PubMed2004

[Investigation of redox homeostasis of liver in experimental and human studies].

Great importance has been attributed to antioxidants in the treatment of conditions associated with oxidative stress for many years. At the same time the antioxidants can exert prooxidant activity. Combined antioxidant treatment is more favourable compared with monotherapy, because antioxidants have scavenger-, compartment- and tissue-specificity and they regenerate each other directly, too. Drugs of chronic liver diseases should be considered because of the role of liver in biotransformation. Our aim was to study the redox status of liver and investigate the effects of natural antioxidants (vegetable lyophilizates, silymarin, metadoxine) on liver redox status. Besides of clinical diagnosis, biochemical, analytical, histological methods were used to assess the free radical-antioxidant balance on the whole. Our in vitro methodological system is suitable for screening natural compounds for primary and secondary antioxidant property as well as membrane-stabilizing activity. A shift in free radical-antioxidant balance was proved in short-term extrahepatic cholestasis, antioxidant-type choleretic compounds can be investigated in this animal model. In human experiments redox status was investigated in the Gilbert's disease and in the most frequent chronic liver disorder in Hungary, in alcoholic liver disease. The improvement of non-enzymatic antioxidant defence system was found in Gilbert's disease without the alteration of free radical-antioxidant balance. Our results proved the role of free radical reactions in alcoholic liver disease and underlined the greater women vulnerability to alcohol toxicity. The chemiluminometric measurements in erythrocytes is suitable for the estimation of progression of alcoholic liver disease and of efficacy of antioxidant therapy.

Animals↗

PubMed2004

[Free radical scavenger and lipid peroxidation inhibiting effects of medicinal plants used in phytotherapy].

Epidemiological and clinical studies have proved the beneficial effect of bioactive compounds of vegetables and medicinal plants used in phytotherapy on prevention of several diseases. Beyond the well-known natural antioxidants, such as vitamins, other natural substances can function as antioxidants. In 1992 the Saas Fee Declaration was published by leader nutritionist and biochemists underlining the importance of prevention in health maintenance based on scientific studies with natural compounds. According to the declaration the antioxidants are the main active and beneficial components. Authors joining with the spirit of Saas Fee Declaration have worked out a complex examination system to study the antioxidant, free radical scavenging and inhibitory effects on lipid peroxidation of isolated components, natural plant extracts and herbal preparations. The members of the system are the followings: hydrogendonating ability, reducing power, chelating activity, free radical scavenging activities measured by chemiluminescence techniques, electron paramagnetic resonance / spin trapping studies, inhibition of lipid peroxidation induced in rat brain / liver microsomes, consequencies and treatment of experimental hyperlipidemia, morphological and histological studies. Only one measurement cannot give enough information about the antioxidant properties of the products. Complex in vitro examination of a novel antioxidant can draw pictures of correlation between the chemical structure and antioxidant effect, the mechanism of its favourable effect and its presumable role in prevention of lipid peroxidation. With the use of these results planning and execution of in vivo examinations should be more precise, practical and essential.

Antioxidants↗

PubMed2003

[Possibilities of monitoring oxidative damage and its clinical aspects].

In their earlier work the authors reviewed some methods, which appeared to be suitable for monitoring the redox-status of the human organism and, therefore, may be applied under routine clinical laboratory circumstances. This possibility can lead to a new perspective to set up epidemiological studies in different populations in order to investigate connecting points between the manner of life, alimentary customs (especially consumption of antioxidants), and the risk of chronic or acute illnesses. In this review the authors surveyed different methods for the measurements of end products (lipids, proteins, nucleic acids) produced by cells and tissues through oxidative injury, caused by the free radicals. These methods have already served the work of scientists for many years, helping them to obtain experience about the pathomechanisms of different diseases. With the help of these measurements it could be possible to monitor the results of medical therapy or surgical treatments, or in the field of chronic illnesses e.g. diabetes, to predict the possible development of late complications.

Acute Disease↗