Modulation of the Human Erythrocyte Antioxidant System by the 5- and 6-Membered Heterocycle-Based Nitroxides.

Nitroxides are stable radicals consisting of a nitroxyl group, >N-O, which carries an unpaired electron. This group is responsible for the paramagnetic and antioxidant properties of these compounds. A recent study evaluated the effects of pyrrolidine and pyrroline derivatives of nitroxides on the antioxidant system of human red blood cells (RBCs).

Acrolein Induces Changes in Cell Membrane and Cytosol Proteins of Erythrocytes.

High concentrations of acrolein (2-propenal) are found in polluted air and cigarette smoke, and may also be generated endogenously. Acrolein is also associated with the induction and progression of many diseases. The high reactivity of acrolein towards the thiol and amino groups of amino acids may cause damage to cell proteins.

Contribution of staphylococcal virulence factors in the pathogenesis of thrombosis.

Staphylococci are responsible for many infections in humans, starting with skin and soft tissue infections and finishing with invasive diseases such as endocarditis, sepsis and pneumonia, which lead to high mortality. Patients with sepsis often demonstrate activated clotting pathways, decreased levels of anticoagulants, decreased fibrinolysis, activated endothelial surfaces and activated platelets. This results in disseminated intravascular coagulation and formation of a microthrombus, which can lead to a multiorgan failure.

Factors Influencing Venous Remodeling in the Development of Varicose Veins of the Lower Limbs.

One of the early symptoms of chronic venous disease (CVD) is varicose veins (VV) of the lower limbs. There are many etiological environmental factors influencing the development of chronic venous insufficiency (CVI), although genetic factors and family history of the disease play a key role. All these factors induce changes in the hemodynamic in the venous system of the lower limbs leading to blood stasis, hypoxia, inflammation, oxidative stress, proteolytic activity of matrix metalloproteinases (MMPs), changes in microcirculation and, consequently, the remodeling of the venous wall.

The Effect of Piperidine Nitroxides on the Properties of Metalloproteins in Human Red Blood Cells.

Nitroxides are stable, low molecular-weight radicals containing a nitroxide group that has an unpaired electron. The presence of a nitroxide group determines their redox properties. The effect of the piperidine nitroxides, Tempo, Tempol, and Tempamine, on metalloproteins (hemoglobin, superoxide dismutase, catalase) and lactate dehydrogenase in red blood cells was investigated in this research.

Indoxyl Sulfate Induces Oxidative Changes in Plasma and Hemolysate.

The deteriorating function of the kidneys in chronic kidney disease (CKD) is associated, among other things, with the retention of many unnecessary metabolic products in the body. Indoxyl sulfate (IS) belongs to the group of uremic toxins with a high protein binding affinity. Moreover, this compound can generate oxidative stress.

Alterations in the Plasma and Red Blood Cell Properties in Patients with Varicose Vein: A Pilot Study.

The varicose vein results from the inefficient functioning of the valves in the lower limb veins, making the blood flow slow down and leading to blood stasis and hypoxia. This type of vein dysfunction might be a result of the development of oxidative stress. We compared oxidative stress markers in the plasma and erythrocytes obtained from peripheral veins and varicose veins in the same patients (glutathione, nonenzymatic antioxidant capacity (NEAC), catalase (CAT) and acetylcholinesterase (AChE) activity, thiols, thiobarbituric acid-reactive substance (TBARS), and protein carbonyls).

Reactive Oxygen Species and Their Involvement in Red Blood Cell Damage in Chronic Kidney Disease.

Reactive oxygen species (ROS) released in cells are signaling molecules but can also modify signaling proteins. Red blood cells perform a major role in maintaining the balance of the redox in the blood. The main cytosolic protein of RBC is hemoglobin (Hb), which accounts for 95-97%.

Alterations in the Properties of Red Blood Cells in Men with Coronary Artery Diseases after Comprehensive Cardiac Rehabilitation.

Purpose: Comprehensive cardiac rehabilitation (CCR) is a complex program aimed at improving the health status of patients with coronary artery disease (CAD), especially those who have been subjected to cardiac interventions (PCI and CABG).The aim of this study was to measure the changes in the properties of red blood cells (RBCs) in men with CAD after cardiac intervention and after participation in CCR program.

Methods: In this study, we have investigated the influence of the physical training-based CCR program in 12 men with CAD, after PCI or CABG.

Doxyl Nitroxide Spin Probes Can Modify Toxicity of Doxorubicin towards Fibroblast Cells.

The biological properties of doxyl stearate nitroxides (DSs): 5-DS, Met-12-DS, and 16-DS, commonly used as spin probes, have not been explored in much detail so far. Furthermore, the influence of DSs on the cellular changes induced by the anticancer drug doxorubicin (DOX) has not yet been investigated. Therefore, we examined the cytotoxicity of DSs and their ability to induce cell death and to influence on fluidity and lipid peroxidation (LPO) in the plasma membrane of immortalised B14 fibroblasts, used as a model neoplastic cells, susceptible to DOX-induced changes.

Factors Affecting the Formation and Treatment of Thrombosis by Natural and Synthetic Compounds.

Venous thromboembolism (VTE) refers to deep vein thrombosis (DVT), whose consequence may be a pulmonary embolism (PE). Thrombosis is associated with significant morbidity and mortality and is the third most common cardiovascular disease after myocardial infarction and stroke. DVT is associated with the formation of a blood clot in a deep vein in the body.

Microbial Modulation of Coagulation Disorders in Venous Thromboembolism.

Venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE), is the third leading cause of cardiovascular death in the world. Important risk factors of thrombosis include bed restraint, surgery, major trauma, long journeys, inflammation, pregnancy, and oral contraceptives, previous venous thromboembolism, cancer, and bacterial infections. Sepsis increases the risk of blood clot formation 2-20 times.

Cytotoxic effect, generation of reactive oxygen/nitrogen species and electrochemical properties of Cu(ii) complexes in comparison to half-sandwich complexes of Ru(ii) with aminochromone derivatives.

This paper describes the synthesis of new 6-aminoflavone (6AFl (3)) and 6-aminochromone (6AC (4)) complexes with Cu(ii) and Ru(ii) ions ([Cu(6AC)Cl] (3a), [Cu(6AFl)Cl] (4a), [Ru(-cymene)(6AC)Cl] (4b)) and comparison of their properties with the previously described 7-aminoflavone (7AFl (1)) and 7-amino-2-methylchromone (7A2MC (2)) analogues. The cytotoxic effect of all these complexes against two human leukaemia cell lines (HL-60 and NALM-6), melanoma WM-115 cells and COLO205 cells, is determined. The cytotoxicity of copper(ii) complexes, especially [Cu(6AFl)Cl] (3a) was higher than ruthenium(ii) complexes with the same ligands.

Therapeutic potential of natural compounds in inflammation and chronic venous insufficiency.

The term varicose vein refers to the twisted and swollen vein visible under the skin surface which occurs most commonly in the leg. Epidemiological studies report a varying percentage of incidences from 2 to 56% in men and <1-60% in women. Venous insufficiency is most often caused by the damage to the valves and walls of the veins.

Anticancer Activity of Natural Compounds from Plant and Marine Environment.

This paper describes the substances of plant and marine origin that have anticancer properties. The chemical structure of the molecules of these substances, their properties, mechanisms of action, their structure⁻activity relationships, along with their anticancer properties and their potential as chemotherapeutic drugs are discussed in this paper. This paper presents natural substances from plants, animals, and their aquatic environments.

Indoxyl Sulfate Generates Free Radicals, Decreases Antioxidant Defense, and Leads to Damage to Mononuclear Blood Cells.

Indoxyl sulfate (IS) is a uremic toxin that has been associated with inflammation and oxidative stress as well as with the progression of chronic kidney disease (CKD). IS is a protein metabolite that is concentrated in the serum of CKD patients. IS is a well-known uremic toxin, but there are very few reports on the effect of IS on cells including mononuclear cells (MNCs).

Alterations in conformational state of albumin in plasma in chronic hemodialyzed patients.

Objective: In chronic hemodialyzed (CH) patients the balance between production of reactive oxygen species and antioxidant defense system is disturbed and shifted towards oxidative conditions. The properties of albumin in CH patients were studied before hemodialysis (HD) and post-HD.

Methods: Two oxidants were applied, organic t-butyl hydroperoxide (t-BOOH) and inorganic hydroperoxide (H2O2), for oxidation of albumin molecules.

Nitroxides as Antioxidants and Anticancer Drugs.

Nitroxides are stable free radicals that contain a nitroxyl group with an unpaired electron. In this paper, we present the properties and application of nitroxides as antioxidants and anticancer drugs. The mostly used nitroxides in biology and medicine are a group of heterocyclic nitroxide derivatives of piperidine, pyrroline and pyrrolidine.

Carbamylation and oxidation of proteins lead to apoptotic death of lymphocytes.

The apoptotic/necrotic changes in isolated human peripheral blood mononuclear cells (MNCs) subjected to hydrogen peroxide (HO), cyanate (NaOCN) and their combination were examined. The mitochondrial potential (ΔΨm), the activities of caspases (-2, -3, -6, -8 and -9) and the level of carbonyls and amino groups in proteins were determined and DNA fragmentation. Apoptotic or necrotic cells were identified by fluorescence microscopy using double staining with Hoechst 33258/propidium iodide.

Photoprotective and radioprotective properties of nitroxides and their application in magnetic resonance imaging.

Nitroxides are a group of stable organic radicals of low molecular weight having a nitroxyl group > N-.O, which has an unpaired electron. The presence of this group allows a nitroxide to participate in redox reactions.

Investigation of oxidative stress parameters in different lifespan erythrocyte fractions in young untrained men after acute exercise.

What is the central question of this study? What is the influence of a single bout of exercise on the properties of erythrocyte fractions at different ages? What is the main finding and its importance? A single bout of exercise in untrained men induced oxidative stress in erythrocytes and had an influence on antioxidant defense in these cells. Old erythrocytes were more sensitive to oxidative damage than young and middle-aged cells. Higher levels of glutathione in old erythrocyte fractions did not protect them against oxidative stress.

Cardiac rehabilitation improves the blood plasma properties of cardiac patients.

Cardiac rehabilitation (CR) improves exercise tolerance and general function. However, its effects on blood plasma in cardiac patients remain uncertain. Our aim was to examine the effect of comprehensive CR on the oxidative stress parameters and antioxidant plasma status in patients with coronary artery disease (CAD) after cardiac interventions.

[Carbamylation of proteins--mechanism, causes and consequences].

Carbamylation (carbamoylation) is a post-translational modification resulting from the nonenzymatic reaction between isocyanic acid and free functional groups of proteins, in particular with the free amino groups. This reaction alters structural and functional properties of proteins and results in faster aging of proteins. Urea present in the body can be transformed into cyanate and its more reactive form, isocyanic acid.

Changes in lymphocyte properties after employment of the combination of carbamylation and oxidative stress, an in vitro study.

It is well known that oxidative stress and carbamylation alter macromolecule properties and functions. We evaluated the influence of sodium cyanate (NaOCN) and the combination of cyanate and hydrogen peroxide (H2O2) on nonenzymatic antioxidant capacity (NEAC), total thiols, reduced glutathione (GSH) and hydroperoxide level in mononuclear blood cells (MNCs). We also examined plasma membrane properties of MNCs using the spin labeling method in EPR spectroscopy (electron paramagnetic resonance spectroscopy).

Detection and analysis of spin signal in spin-labeled poly(l-lysine).

In this paper, the authors present the study of spin-labeled poly(l-lysine) biological molecules (polypeptides) using electron paramagnetic resonance, atomic force microscopy, and electron spin noise-scanning tunneling microscopy. In the presented studies, the authors were able to obtain the information about the local distribution of the spin signal emission, and they registered the spectra for the selected area with nanometer resolution. The preparation method of spin-labeled biopolymer, experimental setup, and the procedure of calibration are also described in detail.