Antioxidative action of polyamines in protection of phospholipid membranes exposed to ozone stress.

In the present work, Langmuir monolayers were used to study the interaction of putrescine (a cationic antioxidant) with anionic charged membranes (1,2-dioleoyl-sn-glycerol-3-phosphate) under oxidative stress caused by the presence of ozone in the water phase. Calcium ions and acidic environment were used to compare the electrostatic and antioxidant effects of putrescine with those of an inorganic cation. It has been shown that the main role of putrescine in protecting systems against oxidation is its rapid reaction with ROS.

The Effects of the Structure and Composition of the Hydrophobic Parts of Phosphatidylcholine-Containing Systems on Phosphatidylcholine Oxidation by Ozone.

The degree of lipid unsaturation is a parameter used to describe membrane susceptibility to oxidation. This paper highlights the importance of double bond distribution in the hydrophobic parts of lipid layers. The problem was studied by determining the effects induced by ozone dissolved in an aqueous phase acting on layers of unsaturated cholines of various molecular structures, including bi-unsaturated (DOPC), mono-unsaturated (POPC) and natural origin (soy PC).

Aggregation/dispersion transitions of T4 phage triggered by environmental ion availability.

Background: Bacteriophage survives in at least two extremes of ionic environments: bacterial host (high ionic-cytosol) and that of soil (low ionic-environmental water). The impact of ionic composition in the micro- and macro-environments has not so far been addressed in phage biology.

Results: Here, we discovered a novel mechanism of aggregation/disaggregation transitions by phage virions.

Interactions of tumour-derived micro(nano)vesicles with human gastric cancer cells.

Background: Tumour cells release membrane micro(nano)fragments called tumour-derived microvesicles (TMV) that are believed to play an important role in cancer progression. TMV suppress/modify antitumour response of the host, but there is also some evidence for their direct interaction with cancer cells. In cancer patients TMV are present in body fluid and tumour microenvironment.

α-Tocopherol/Gallic Acid Cooperation in the Protection of Galactolipids Against Ozone-Induced Oxidation.

The protective ability of α-tocopherol (TOH) and gallic acid (GA) acting simultaneously at the moment of oxidizer application was evaluated by determination of galactolipid layers' oxidation degree. Addition of GA resulted in a significant decrease of ozone-derived radicals shifting the threshold of lipid sensitivity by an amount approximately corresponding to the GA intake in bulk reaction with ozone. TOH presence in lipid layers results in a change of the role of GA which additionally may be involved in the reduction of tocopheroxyl radical formed during oxidation.

Isolation and characterization of circulating micro(nano)vesicles in the plasma of colorectal cancer patients and their interactions with tumor cells.

Micro(nano)vesicles (MV) are regarded as important messengers in cell-to-cell communication. There is also evidence for their pivotal role in cancer progression. Circulating MV are of different body cells origin, including tumor cell‑derived MV (TMV) in cancer patients.

Physicochemical aspects of reaction of ozone with galactolipid and galactolipid-tocopherol layers.

The impact of reaction of galactolipids with ozone on the physicochemical properties of their monolayers was examined. In Megli and Russo (Biochim Biophys Acta, 1778:143-152, 2008), Cwiklik and Jungwirth (Chem Phys Lett, 486:99-103, 2010), Jurkiewicz et al. (Biochim Biophys Acta, 1818:2388-2402, 2012), Khabiri et al.

Mechanical and electrokinetic effects of polyamines/phospholipid interactions in model membranes.

The mechanical and electrical properties of phospholipids layers influenced by interaction with polyamines were determined by measuring surface pressure and compression modulus of monolayers and zeta potential of liposomes. The saturated derivative of phosphatidic acid (DPPA) formed layers of the organization varying with compression degree. Contact of DPPA layers with polyamines present in the subphase resulted in changing their mechanical properties and the conditions in which the layer reorganization appears.

Zeta potential of mica covered by colloid particles: a streaming potential study.

The streaming potential of mica covered by monodisperse latex particles was measured using the parallel-plate channel, four-electrode cell. The zeta potential of latex bearing amidine charged groups was regulated by the addition of NaCl (10(-4)-10(-2) M) and MgCl(2) (10(-4)-10(-2) M) at a constant pH 5.5 and by the change in pH (4-12) at 10(-2) M NaCl.

Circulating tumour-derived microvesicles in plasma of gastric cancer patients.

Cell membrane microfragments called microvesicles (MV) originating from different cells are circulating in the blood of healthy subjects and their elevated numbers are found in different diseases, including cancer. This study was designed to characterise MV present in plasma of gastric cancer patients. Since majority of MV in blood are platelets-derived (PMV), plasma samples deprived of PMV were used.

Effect of tocopherol on surface properties of plastid lipids originating from wheat calli cultivated in cadmium presence.

The behaviour of equimolar mixtures of alpha-tocopherol with monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG) and phospholipids (PL) isolated from wheat calli cultured on media with and without cadmium was investigated at the air-water interface by surface pressure-area (pi-A) measurements established using an automated Langmuir-type film balance. It was found that monolayers of all studied compounds were expanded. The additivity rule was not fulfilled and the collapse pressure of mixtures was different from these recorded for pure components.

Effect of selenium on characteristics of rape chloroplasts modified by cadmium.

Selenium appears to be an important protective agent that decreases cadmium-induced toxic effects in animals and plants. The aim of these studies was to investigate the changes of properties of chloroplast membranes obtained from Cd-treated rape seedlings caused by Se additions. Chloroplasts were isolated from leaves of 3-week-old rape plants cultured on Murashige-Skoog media supplied with 2 microM Na(2)SeO(4) and/or 400 microM CdCl(2) under in vitro conditions.

Particle assembly on surface features (patterned surfaces).

Irreversible adsorption (deposition) of spherical particles on surface features of various shapes (collectors) was studied using the random sequential adsorption (RSA) model. The collectors in the form of linear line segments, semicircles, and circles were considered. Numerical simulation of the Monte Carlo type enabled one to determine particle configurations, the jamming coverage, and the end to end length of particle monolayers for various collector length (L) to particle size (d) ratio L = L/d.

Hoc protein regulates the biological effects of T4 phage in mammals.

We previously investigated the biological, non-antibacterial effects of bacteriophage T4 in mammals (binding to cancer cells in vitro and attenuating tumour growth and metastases in vivo); we selected the phage mutant HAP1 that was significantly more effective than T4. In this study we describe a non-sense mutation in the hoc gene that differentiates bacteriophage HAP1 and its parental strain T4. We found no substantial effects of the mutation on the mutant morphology, and its effects on electrophoretic mobility and hydrodynamic size were moderate.

Electric and structural studies of hormone interaction with chloroplast envelope membranes isolated from vegetative and generative rape.

The electric and structural properties of envelope membranes of chloroplasts obtained from vegetative and generative plants of rape and the effect of hormone (IAA, GA(3) and zearalenone) treatment were determined by zeta potential and small-angle X-ray scattering (SAXS) methods. Chloroplasts were isolated from leaves cut off from the vegetative (before cooling) and generative apical parts of plants. The lipid composition of chloroplast envelope membranes were analyzed by chromatographic techniques.

Irreversible adsorption of particles on heterogeneous surfaces.

Methods of theoretical and experimental evaluation of irreversible adsorption of particles, e.g., colloids and globular proteins at heterogeneous surfaces were reviewed.

Electrokinetics of heterogeneous interfaces.

The influence of surface heterogeneity of various types on electrokinetic parameters is reviewed. The scope of the paper covers classical electrokinetic phenomena characterized by linear dependence of electrokinetic parameters vs. related driving forces.

The influence of phytohormones on zeta potential and electrokinetic charges of winter wheat cells.

The zeta potential measurements of protoplasts obtained from winter wheat cell culture and phospholipid liposomes were performed to determine the electrokinetic charge in a medium containing various phytohormones (kinetin, 2,4-D and zearalenone) in absence and in presence of 2 x 10(-5) MCa2+. Calli were induced from immature inflorescences (inf) and embryos (emb) and cultured to obtain non-embryogenic (NE) and embryogenic (E) cell tissues. All investigated phytohormones indicate ability to adsorb to the negatively charged surfaces (latex, L88 - model negative adsorption site) both in water solutions and at the presence of mannitol and buffer (MES).