Full-text resources of PSJD and other databases are now available in the new Library of Science.
Visit https://bibliotekanauki.pl

Refine search results

Journals help
Years help
Authors help
Preferences help
enabled [disable] Abstract
Number of results

Results found: 28

Number of results on page
first rewind previous Page / 2 next fast forward last

Search results

Search:
in the keywords:  reactive oxygen species
help Sort By:

help Limit search:
first rewind previous Page / 2 next fast forward last
EN
Purpose. In adult liver transplant recipients, coronary artery disease and congestive heart failure are significant cause of morbidity and mortality. This may be attributed to the long-term immunosuppressive treatment, mostly with calcineurin inhibitors and steroids, which in long-term may be associated with hyperlipidemia, oxidative stress and cardiovascular complications. Since such data for children is sparse, the aim of this study was to assess the lipid and oxidative stress markers after pediatric liver transplantation (LTx). Method. We performed prospective analysis of 74 children, at the median age of 7.9 (2.8-11.6) years, 3.2 (1.2-4.3) years after LTx. We assessed the BMI Z-scores, cholesterol fractions (LDLc, HDLc, VLDLc), triglicerides, apolipoproteins (ApoAI, ApoB, ApoE), LCAT, insulin resistance by HOMA-IR and markers of oxidative stress and atherosclerosis: glutathione (GSH), glutathione peroxidase (GPx), asymmetrical dimethyl arginine (ADMA) and oxidized low-density lipoprotein (oxyLDL). At baseline, the results were compared with a healthy age-and-sex matched control group. After 3.1±0.3 year follow-up we repeated all investigations and compared them with the baseline results. RESULTS. At the baseline, we investigated 74 patients 3.2 (1.2-4.3) years after LTx, at the median age of 7.9 (2.8-11.6) years. The prevalence of overweight or obesity (BMI >85th percentile) was 23% and was more common in girls (24% vs 20%). Fourteen patients had TCH >200 mg%, 9 patients had LDLc >130 mg% and TG were at normal levels in all patients. Compared to the controls, there were no significant differences in lipid profiles but we found decreased GSH (p<0.001) and GPx (p<0.001) which play role as an antioxidant defense. OS markers were higher in the study group: ADMA (p<0.001), and oxyLDL (p<0.0001). Insulin resistance by HOMA-IR was increased in the study group (p=0.0002) but fasting glucose remained within normal ranges in all patients. After 3.1-year follow-up, the BMI >95th and >85Th percentile was present in 8% and 14% respectively. ADMA and oxyLDL decreased, whilst GSH and GPx increased when compared to the baseline. There was also significant decrease in apoB and Lp(a). Conclusion. Children after LTx had normal lipid profiles when compared to controls, however there is a tendency for hypercholesterolemia and obesity, which may play a role in cardiovascular complications in the future. Some markers of oxidative stress were increased after LTx, however further investigations are required to establish its clinical significance.
|
2006
|
vol. 53
|
issue 4
679-684
EN
The budding yeast Saccharomyces cerevisiae is a well studied unicellular eukaryotic organism the genome of which has been sequenced. The use of yeast in many commercial systems makes its investigation important not only from basic, but also from practical point of view. Yeast may be grown under both aerobic and anaerobic conditions. The investigation of the response of eukaryotes to different kinds of stresses was pioneered owing to yeast and here we focus mainly on the so-called oxidative stress. It is a result of an imbalance between the formation and decomposition of reactive oxygen species increasing their steady-state concentration. Reactive oxygen species may attack any cellular component. In the present review oxidation of proteins in S. cerevisiae is analyzed. There are two connected approaches to study oxidative protein modification - characterization of the overall process and identification of individual oxidized proteins. Because all aerobic organisms possess special systems which defend them against reactive oxygen species, the involvement of so-called antioxidant enzymes, particularly superoxide dismutase and catalase, in the protection of proteins is also analyzed.
EN
The aim of the study was an evaluation of changes in protein level and activity of SOD isoenzymes, and the participation of AP-1 and NF-κB in subsequent stages of colorectal cancer development. Studies were conducted on 65 colorectal cancers. Controls were unchanged colon regions. Activity of SOD isoenzymes, lipid peroxidation level (TBARS), and protein level of SOD1, SOD2, AP-1 and NF-κB were determined. We found that the protein level and activity of SOD isoenzymes and protein level of AP-1 and NF-κB change in subsequent stages of clinical advancement of colorectal cancer, according to UICC (I-IV), and in grades of tumor cells differentiation (G1-G3). These results indicate adaptation of colorectal cancer cells to oxidative stress, and show that the observed changes of SOD activity and protein level depend on gradual progression of colorectal cancer, and suggest an impairment of processes regulated by AP-1 and NF-κB which are critical for tumor progression (proliferation, differentiation and apoptosis).
4
Content available remote

NF-κB signaling pathway and free radical impact

100%
|
2012
|
vol. 59
|
issue 3
323-331
EN
The activation of NF-κB transcription factor is critical for a wide range of processes such as immunity, inflammation, cell development, growth and survival. It is activated by a variety of stimuli including cytokines, ionizing radiation and oxidative stress. Redox modulations of NF-κB pathway have been widely demonstrated. Studies carried out during last years have advanced our knowledge about possible connections between NF-κB pathway and the impact of free radicals. This review is an endeavor to gather recent results focused on this issue, although an important question, whether oxidative stress plays a physiological role in NF-κB activation, seems to be still unanswered.
5
100%
EN
Besides the structural function in proteins, aromatic amino acids are precursors of many important biological compounds essential for normal functioning of the human organism. Many of these compounds may be used as markers for identification of specific pathological states. Comprehensive knowledge about the metabolism of aromatic amino acids and mechanisms of action of their metabolites made it possible to develop effective treatments for many disorders. However, it should not be forgotten that in some pathological conditions, these compounds could not only be involved in the pathogenesis of many disease entities but could also be used as an important tool in prediction of many diseases. This paper contains a review of published literature on aromatic amino acids in the context of physiological processes of the human body and chosen social disorders, such as cancers; psychiatric disorders: depression, anxiety states, schizophrenia, bipolar affective disorders; neurodegenerative, and cardiovascular diseases; chronic kidney insufficiency or diabetes.
|
2015
|
vol. 62
|
issue 3
465-473
EN
Neutrophils form the first line of host defense against infections that combat pathogens using two major mechanisms, the phagocytosis or the release of neutrophil extracellular traps (NETs). The netosis (NET formation) exerts additional, unfavorable effects on the fitness of host cells and is also involved at the sites of lung infection, increasing the mucus viscosity and in the circulatory system where it can influence the intravascular clot formation. Although molecular mechanisms underlying the netosis are still incompletely understood, a role of NADPH oxidase that activates the production of reactive oxygen species (ROS) during the initiation of NETs has been well documented. Since several commonly used drugs can affects the netosis, our current study was aimed to determine the effects of selected mucolytic, anti-inflammatory and cardiovascular drugs on NET formation, with a special emphasis on ROS production and NADPH oxidase activity. The treatment of neutrophils with N-acetylcysteine, ketoprofen and ethamsylate reduced the production of ROS by these cells in a dose-dependent manner. NET formation was also modulated by selected drugs. N-acetylcysteine inhibited the netosis but in the presence of H2O2 this neutrophil ability was restored, indicating that N-acetylcysteine may influence the NET formation by modulating ROS productivity. The administration of ethamsylate led to a significant reduction in NET formation and this effect was not restored by H2O2 or S. aureus, suggesting the unexpected additional side effects of this drug. Ketoprofen seemed to promote ROS-independent NET release, simultaneously inhibiting ROS production. The results, obtained in this study strongly suggest that the therapeutic strategies applied in many neutrophil-mediated diseases should take into account the NET-associated effects.
|
2013
|
vol. 60
|
issue 1
1-16
EN
Oxygen is one of the most important molecules on Earth mainly because of the biochemical symmetry of oxygenic photosynthesis and aerobic respiration that can maintain homeostasis within our planet's biosphere. Oxygen can also produce toxic molecules, reactive oxygen species (ROS). ROS play a dual role in biological systems, since they can be either harmful or beneficial to living systems. They can be considered a double-edged sword because at moderate concentrations, nitric oxide (NO•), superoxide anion, and related reactive oxygen species play an important role as regulatory mediators in signalling processes. Many of the ROS-mediated responses actually protect the cells against oxidative stress and re-establish "redox homeostasis". On the other hand, overproduction of ROS has the potential to cause damage. In the recent decades, ROS has become a focus of interest in most biomedical disciplines and many types of clinical research. Increasing evidence from research on several diseases shows that oxidative stress is associated with the pathogenesis of diabetes mellitus, obesity, cancer, cardiovascular diseases, inflammation, ischaemia/reperfusion injury, obstructive sleep apnea, neurodegenerative disorders, hypertension and ageing.
EN
Background: Head and neck neoplasms stand for 6% of all malignant neoplasms worldwide. Chemotherapy has limited use due to the biological properties of the tumor (in the majority of cases moderately and poorly differentiated squamous cell carcinoma). The fundamental molecule used in treatment is cisplatin and its derivates, that can be associated with fluorouracil. The new chemotherapeutic agents are not in common use during the treatment of head and neck malignancies. However, the use of low molecular weight complexes Pd (II) carries the potential of being more effective in therapy. Material and Methods: Fifty-one patients, 30 men and 21 women (aged 52.9 ± 12.1 years) with head and neck cancer were included in the study. Fifty-one healthy subjects, 31 men and 20 women, (aged 54.1 ± 14.7 years) years formed the control group. Antioxidant enzymes, superoxide dismutase, and catalase activities in erythrocytes were examined. Results: An increased level of antioxidant enzymes was seen in the blood samples from patients with head and neck cancer after incubation with Pd (II) complex. In the group we obtained a statistically significant result p = <0.001. Discussion: That project may contribute to the development of new, more efficient head and neck cancer treatment strategies. In our opinion, the results can be used in the future to develop a valuable prognostic marker of the disease. This is important because the initial phase of cancer is asymptomatic. The search for factors involved in pathogenesis translates into economic benefits and makes therapy more effectiveness through the reduction of treatment expenses.
|
2015
|
vol. 62
|
issue 3
445-455
EN
Candida species are associated with an increasing number of life-threatening infections (candidiases), mainly due to the high resistance of these yeast-like fungi to antifungal drugs and oxidative stress. Recently, thiamine (vitamin B1) was found to alleviate stress responses in Saccharomyces cerevisiae; however, thiamine influence on defense systems in pathogenic fungi has never been investigated. The current work was aimed to elucidate the role of thiamine in stress reactions of C. albicans, C. glabrata, C. tropicalis and C. dubliniensis, subjected to hydrogen peroxide treatment. As compared to S. cerevisiae, Candida strains exposed to oxidative stress showed: (i) a much higher dependence on exogenous thiamine; (ii) an increased demand for thiamine diphosphate (TDP) and TDP-dependent enzyme, transketolase; (iii) no changes in gene expression of selected stress markers - superoxide dismutase and catalase - depending on thiamine availability in medium; (iv) a similar decrease of reactive oxygen species (ROS) generation in the presence of thiamine. Moreover, the addition of therapeutic doses of thiamine to yeast culture medium revealed differences in its accumulation between various Candida species. The current findings implicate that the protective action of thiamine observed in S. cerevisiae differs significantly form that in pathogenic Candida strains, both in terms of the cofactor functions of TDP and the effects on fungal defense systems.
EN
Background: Head and neck neoplasms stand for 6% of all malignant neoplasms worldwide. Chemotherapy has limited use due to the biological properties of the tumor (in the majority of cases moderately and poorly differentiated squamous cell carcinoma). The fundamental molecule used in treatment is cisplatin and its derivates, that can be associated with fluorouracil. The new chemotherapeutic agents are not in common use during the treatment of head and neck malignancies. However, the use of low molecular weight complexes Pd (II) carries the potential of being more effective in therapy. Material and Methods: Fifty-one patients, 30 men and 21 women (aged 52.9 ± 12.1 years) with head and neck cancer were included in the study. Fifty-one healthy subjects, 31 men and 20 women, (aged 54.1 ± 14.7 years) years formed the control group. Antioxidant enzymes, superoxide dismutase, and catalase activities in erythrocytes were examined. Results: An increased level of antioxidant enzymes was seen in the blood samples from patients with head and neck cancer after incubation with Pd (II) complex. In the group we obtained a statistically significant result p = <0.001. Discussion: That project may contribute to the development of new, more efficient head and neck cancer treatment strategies. In our opinion, the results can be used in the future to develop a valuable prognostic marker of the disease. This is important because the initial phase of cancer is asymptomatic. The search for factors involved in pathogenesis translates into economic benefits and makes therapy more effectiveness through the reduction of treatment expenses.
12
Content available remote

Properties of chemically oxidized kininogens.

75%
|
2003
|
vol. 50
|
issue 3
753-763
EN
Kininogens are multifunctional proteins involved in a variety of regulatory processes including the kinin-formation cascade, blood coagulation, fibrynolysis, inhibition of cysteine proteinases etc. A working hypothesis of this work was that the properties of kininogens may be altered by oxidation of their methionine residues by reactive oxygen species that are released at the inflammatory foci during phagocytosis of pathogen particles by recruited neutrophil cells. Two methionine-specific oxidizing reagents, N-chlorosuccinimide (NCS) and chloramine-T (CT), were used to oxidize the high molecular mass (HK) and low molecular mass (LK) forms of human kininogen. A nearly complete conversion of methionine residues to methionine sulfoxide residues in the modified proteins was determined by amino acid analysis. Production of kinins from oxidized kininogens by plasma and tissue kallikreins was significantly lower (by at least 70%) than that from native kininogens. This quenching effect on kinin release could primarily be assigned to the modification of the critical Met-361 residue adjacent to the internal kinin sequence in kininogen. However, virtually no kinin could be formed by human plasma kallikrein from NCS-modified HK. This observation suggests involvement of other structural effects detrimental for kinin production. Indeed, NCS-oxidized HK was unable to bind (pre)kallikrein, probably due to the modification of methionine and/or tryptophan residues at the region on the kininogen molecule responsible for the (pro)enzyme binding. Tests on papain inhibition by native and oxidized kininogens indicated that the inhibitory activity of kininogens against cysteine proteinases is essentially insensitive to oxidation.
EN
Chronic myeloid leukemia (CML) results from the t(9;22) reciprocal chromosomal translocation producing the BCR-ABL1 gene, conferring growth and proliferation advantages in the CML cells. CML progresses from chronic, often syndrome-free, to blast phase, fatal if not treated. Although the involvement of BCR-ABL1 in some signaling pathways is considered as the cause of CML, the mechanisms resulting in its progression are not completely known. However, BCR-ABL1 stimulates the production of reactive oxygen species (ROS), which levels increase with CML progression and induce BCR-ABL1 self-mutagenesis. Introducing imatinib and other tyrosine kinase inhibitors (TKIs) to CML therapy radically improved its outcome, but TKIs-resistance became an emerging problem. TKI resistance can be associated with even higher ROS production than in TKI-sensitive cells. Therefore, ROS-induced self-mutagenesis of BCR-ABL1 can be crucial for CML progression and TKI resistance and in this way should be taken into account in therapeutic strategies. As a continuous production of ROS by BCR-ABL1 would lead to its self-destruction and death of CML cells, there must be mechanisms controlling this phenomenon. These can be dependent on DNA repair, which is modulated by BCR-ABL1 and can be different in CML stem and progenitor cells. Altogether, the mechanisms of the involvement of BCR-ABL1 in ROS signaling can be engaged in CML progression and TKI-resistance and warrant further study.
|
2014
|
vol. 61
|
issue 4
795-799
EN
The protective action of quercetin against the pro-oxidant and apoptotic effect of etoposide was investigated in HL-60 cells with a high level of myeloperoxidase (MPO) activity and in cells treated with MPO inhibitor, 4-aminobenzoic acid hydrazide (ABAH). Quercetin significantly protected MPO-rich cells against the pro-oxidative (p<0.05) and apoptotic (p<0.05) effects of etoposide. Pre-treatment with ABAH abolished this protective influence of quercetin on apoptosis induced by etoposide but actually enhanced the action effect of quercetin against etoposide-generated reactive oxygen species (ROS) level by this cytostatic drug. Thus quercetin can protect HL-60 cells against the pro-oxidative activity of etoposide regardless of MPO activity.
|
|
vol. 51
|
issue 1
223-229
EN
Mitochondrial respiration is considered to provide reactive oxygen species (ROS) as byproduct of regular electron transfer. Objections were raised since results obtained with isolated mitochondria are commonly transferred to activities of mitochondria in the living cell. High electrogenic membrane potential was reported to trigger formation of mitochondrial ROS involving complex I and III. Suggested bioenergetic parameters, starting ROS formation, widely change with the isolation mode. ROS detection systems generally applied may be misleading due to possible interactions with membrane constituents or electron carriers. Avoiding these problems no conditions reported to transform mitochondrial respiration to a radical source were confirmed. However, changing the physical membrane state affected the highly susceptible interaction of the ubiquinol/bc1 redox complex such that ROS formation became possible.
EN
Two natural flavonoids, quercetin and isorhamnetin 3-O-acylglucosides, were examined for their inhibitory influence on the in vitro production and release of reactive oxygen species in polymorphonuclear neutrophils (PMNs). The generation of superoxide radical, hydrogen peroxide and hypochlorous acid were measured by, respectively, cytochrome c reduction, dichlorofluorescin oxidation and taurine chlorination. Membrane lipid oxidation was studied by the thiobarbituric acid method in mouse spleen microsomes. The addition of flavonoids at the concentration range 1-100 μM inhibited PMNs oxidative metabolism and lipid peroxidation in a dose-dependent manner. The results suggest that these flavonoids suppress the oxidative burst of PMNs and protect membranes against lipid peroxidation.
18
Content available remote

Alternative oxidase in higher plants.

75%
|
2003
|
vol. 50
|
issue 4
1257-1271
EN
Plant respiratory chain branches at the level of ubiquinone from where the electrons flow through the cytochrome pathway or to alternative oxidase. Transfer of electrons from ubiquinone to oxygen by alternative oxidase has a non-protonmotive character and, by bypassing two sites of H+ pumping in complexes III and IV, lowers the energy efficiency of respiration. In this paper we review theoretical and experimental studies about the structure and possible function of alternative oxidase. The evidence for specific gene expression dependent on the physiological, developmental and environmental conditions is also described. We underline the physiological role of alternative oxidase as a "survival" protein that allows plants to cope with the stressful environment.
EN
WSTĘP: Choroba zwyrodnieniowa stawów kolanowych (gonartroza – GA) należy do najczęstszych schorzeń narządu ruchu, a ból i ograniczenie ruchomości kolana są najdotkliwiej odbieranymi przez pacjentów objawami zmian zwyrodnieniowych. Celem pracy było sprawdzenie, czy podanie dostawowe preparatu kwasu hialuronowego wpływa na funkcje stawu kolanowego, wybrane parametry układu antyoksydacyjnego i natężenie stresu oksydacyjnego we krwi u pacjentów z gonartrozą. MATERIAŁ I METODY: Grupa badana 1K obejmowała 96 pacjentów z chorobą zwyrodnieniową stawu kolanowego, którym podano kwas hialuronowy do jednego stawu kolanowego, natomiast do grupy badanej 2K włączono 33 pacjentów, którym podano kwas hialuronowy do obu stawów kolanowych. Badanie prowadzono przez 40 tygodni według ustalonego protokołu. Oznaczono całkowity status oksydacyjny (TOS) osocza, zawartość grup sulfhydrylowych (SH) w surowicy, aktywność katalazy (CAT) w erytrocytach, aktywność dysmutazy ponadtlenkowej (SOD) w osoczu i erytrocytach, aktywność peroksydazy glutationowej (GPx) w erytrocytach. WYNIKI: Po leczeniu wiskosuplementacyjnym odnotowano zmniejszenie nasilenia bólu oraz poprawę w badanych skalach VAS i HHS, przy czym nieco większą poprawę stwierdzono w przypadku zajęcia jednego kolana. Po leczeniu dostawowym kwasem hialuronowym stwierdzono znamienny spadek aktywności SOD oraz CAT a wzrost aktywności GPx, wzrost stężenia grup SH w obu grupach oraz spadek stężenia TOS. WNIOSKI: Wiskosuplementacja w chorobie zwyrodnieniowej stawu kolanowego istotnie redukuje ból kolana i poprawia jego funkcje oraz wywołuje korzystne zmiany w układzie antyoksydacyjnym krwi. Efekt leczenia jest porównywalny zarówno w przypadku podawania preparatu kwasu hialuronowego do jednego, jaki i do obu stawów kolanowych.
PL
INTRODUCTION: Osteoarthritis of the knee (gonarthritis – GA) is one of the most common musculoskeletal disorders. Pain and limitation of joint movement are the most constant and troublesome symptoms of the joint pathology. The aim of the study was to examine viscosupplementation therapy with hyaluronic acid. MATERIAL AND METHODS: 96 patients were administered hyaluronic acid unilaterally (the 1K group), while 33 patients were administered hyaluronic acid bilaterally (the 2K group) in a 40-day cycle. The stage of the disease was assessed based on medical history, physical examination and a questionnaire survey. Analysis of the following parameters was performed: serum level of sulfhydryl groups (SH), total oxidant status (TOS), catalase activities (CAT) and glutathione peroxidase (GPx) in erythrocytes and superoxide dismutase activity (SOD) in plasma and erythrocytes. RESULTS: Viscosupplementation resulted in pain reduction and improvement in the HHS score. The SOD and CAT activities were significantly decreased, while GPx activity as well as the SH level significantly increased in both the examined groups. In addition the TOS values significantly decreased. CONCLUSION: Viscosupplementation therapy with hyaluronic acid significantly reduces pain of the knee joint, improves its function and has a beneficial effect on the pro/antioxidant balance in the blood of patients diagnosed with GA. The effects of uni- and bilateral administration of hyaluronic acid are similar.
EN
The present study provides a comprehensive data on the antioxidant, antimicrobial and neutrophil-modulating activities of extracts from six medicinal plants - blackberry (Rubus fruticosus) leaves, chokeberry (Aronia melanocarpa) leaves, hawthorn (Crataegus monogyna) leaves, lady's mantle (Alchemilla glabra) aerial parts, meadowsweet (Filipendula ulmaria) aerial parts and raspberry (Rubus idaeus) leaves. In order to analyze the antioxidant activity of the herbs, several methods (ORAC, TRAP, HORAC and inhibition of lipid peroxidation) were used. Blackberry leaves and meadowsweet extracts revealed the highest antioxidant activities via all methods. All extracts studied blocked almost completely the opsonized zymosan particle-activated ROS production by neutrophils from human whole blood. On the other hand, the effect of extracts on phorbol myristate acetate-activated ROS production was much milder and even nonsignificant in the case of chokeberry leaves. This latter result suggests that extracts (apart from their antioxidative activity) interfere with the signaling cascade of phagocyte activation upstream of the protein kinase C activation. The antimicrobial activity of the investigated extracts against 11 human pathogens was investigated using three different methods. Meadowsweet and blackberry leaves extracts had the highest antimicrobial effect and the lowest minimal inhibiting concentrations (MICs) against the microorganisms tested.
first rewind previous Page / 2 next fast forward last
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.