The Role H-Bonding and Supramolecular Structures in Homogeneous and Enzymatic Catalysis.

The article analyzes the role of hydrogen bonds and supramolecular structures in enzyme catalysis and model systems. Hydrogen bonds play a crucial role in many enzymatic reactions. However, scientists have only recently attempted to harness the power of hydrogen bonds in homogeneous catalytic systems.

Art and Agency in the Era of De-Structuration: Exploring a New Field.

Human agency, implying, from sociology's perspective, proactive or even transformative individual behaviour upon the social world (or "social structures" as sociologists call them), remains one of the central concepts and problems for both social science and practice. Current stage of societal evolution, de-structuration, makes individual agency especially important for both individual and collective well-being. In this context, the contribution of contemporary art (2018-2022) to agency issues remains little known in the academic world.

[The Effect of NT-1505 on a Membrane Structure of Endoplasmic Reticulum in vivo].

The effect of neuroprotector NT-1505 on endoplasmic reticulum membranes was studied. It was shown that the dynamics of changes in lipid and near-protein areas microviscosity of endoplasmic reticulum membranes at drug administration is of an antibate nature. This points to the absence of pathological disturbances in the membrane structure.

[Studying the effect of Dimebon and NT-1505 on microviscosity of mice brain synaptosomal membranes in vivo by EPR spin labeling method].

In this work membrane fluidity alterations in synaptosomes, isolated from mice brain tissue, at chronic administration of neuroprotectors Dimebon and NT-1505 in vivo were studied. Membrane microviscosity was measured by electron paramagnetic resonance spin labeling of 2,2,6,6-tetramet-hyl-4-capryloyl-oxylpiperidine-l-oxyl (lipid probe) and 5,6-benzo-2,2,6,6-tetramethyl-1,2,3,4-tetrahydro-gamma-carboline-3-oxyl (near protein probe). It was shown that the neuroprotectors Dimebon and NT-1505 affect a membrane structure.

[Effects of low doses of essential oil on the antioxidant state of the erythrocytes, liver, and the brains of mice].

We studied the effects of essential oil from oregano and clove and a mixture of lemon essential oil and a ginger extract on the antioxidant state of organs in intact and three experimental groups of Bulb mice. We found that the essential oil was an efficient in vivo bioantioxidant when mice were treated with it for 6 months even at very low doses, such as 300 ng/day. All essential oil studied inhibited lipid peroxidation (LPO) in the membranes of erythrocytes that resulted in increased membrane resistance to spontaneous hemolysis, decreased membrane microviscosity, maintenance of their structural integrity, and functional activity.

[Investigation of changes in fluidity of brain membranes in mice bearing experimental Alzheimer's disease using spin labeling electron paramagnetic resonance].

Changes in fluidity of membranes isolated from the microsomal and crude synaptosomal fractions which were obtained from forebrain tissue of mice bearing experimental Alzheimer's disease induced with olfactory bulbectomy were studied. Membrane microviscosity was measured by electron paramagnetic resonance with 2,2,6,6-tetramethyl-4-capryloyl-oxypiperidine-1-oxyl and 5,6-benzo-2,2,6,6-tetramethyl-1,2,3,4-tetrahydro-gamma-carboline-3-oxyl as spin labeling. Phasic alterations in relative fluidity were found during the development of experimental Alzheimer's disease pathology.

[Interrelation between structural state, physicochemical properties and lipid composition in microbial cells].

We performed complex investigations of antioxidant properties and the lipid composition of the five gram-negative bacteria depending on the cultivation season. Structural state, the lipid composition and physicochemical properties of lipids of the three gram-negative bacteria (Renobacter vacuolatum, Flectobacillus major WKM 869, Pseudomonas fluorescens) during their growth and mycelium of four species of the xylotrophic basidiomycetes (Panus tigrinus IBK-131, Fomes fomentarius M71, Laetiporus sulfureus M131, Piptoporus betulinus M60) during the lag phase were also studied. Changes in the composition of the lipid component in the studied bacteria led to considerable structural rearrangements in their membrane system during the growth of bacteria.

[Changes in fatty acid composition in the brain and liver in aging mice of high cancer risk AKR strain and effect of savory essential oil administration on leukemic process].

Age-related alterations of fatty acid composition in liver and brain of AKR mice was investigated. The effect of savory essential oil (Satureja hortensis L.), added with drinking water on fatty acid composition in these organs and the processes of lipid peroxidation in erythrocytes were estimated.

Mouse mutants for the nicotinic acetylcholine receptor ß2 subunit display changes in cell adhesion and neurodegeneration response genes.

Mice lacking expression of the ß2 subunit of the neuronal nicotinic acetylcholine receptor (CHRNB2) display abnormal retinal waves and a dispersed projection of retinal ganglion cell (RGC) axons to their dorsal lateral geniculate nuclei (dLGNs). Transcriptomes of LGN tissue from two independently generated Chrnb2-/- mutants and from wildtype mice were obtained at postnatal day 4 (P4), during the normal period of segregation of eye-specific afferents to the LGN. Microarray analysis reveals reduced expression of genes located on the cell membrane or in extracellular space, and of genes active in cell adhesion and calcium signaling.

[The effect of volatile antioxidants of plant origin on leukemogenesis in mice].

The effect of savory essential oil added with drinking water (150 ng/ml) or with feed (2.5 microg/g) on the lifetime of AKR mice and the parameters of oxidative stress in animal blood were investigated. It was found for the first time that long-term administration of an essential oil in low doses increased the average lifetime of mice by 20-35% and was accompanied by a decrease in the hemolysis level and the content of lipid peroxidation products in erythrocytes of mice, as well as alteration in the structural state of their membranes and stabilization of polyunsaturated fatty acids level in mice liver cells.

Effect of melafen on structure and function of liposome and ehrlich ascitic carcinoma cell membranes.

The effects of melafen (plant growth stimulant) on membrane structure and functions of animal cells were studied. The process of signal transduction from cell surface to intracellular structures and conformation changes in membranes in the presence of this substance were studied by light scatter and differential scanning microcalorimetry. Melafen in a wide range of concentrations (10(-13)-10(-3) M) inhibited Ca(2+) signal system involved in the function of Ca(2+)-dependent K(+) and Cl(-) channels in Ehrlich ascitic carcinoma cells.

Decrease of kappa-opioid receptor mRNA level in ventral tegmental area of male mice after repeated experience of aggression.

Brain opioid systems have been implicated in the regulation of social interaction, including agonistic behaviour. kappa-Opioid receptor B and C mRNA levels were decreased in the ventral tegmental area but not in the nucleus accumbens in male mice with repeated experience of social victories (winners), but not in mice after social defeats (losers) after 10 but not 20 days of confrontations. mu-Opioid receptor mRNA levels were not changed.

Investigation of the role of a second conserved serine in carboxylesterases via site-directed mutagenesis.

Carboxylesterases are enzymes that catalyze the hydrolysis of ester and amide moieties. These enzymes have an active site that is composed of a nucleophile (Ser), a base (His), and an acid (Glu) that is commonly known as a catalytic triad. It has previously been observed that the majority of carboxylesterases and lipases contain a second conserved serine in their active site [Proteins, 34 (1999) 184].

[Effect of low doses of phenozan on lactate dehydrogenase and microviscosity of microsomal membranes of brain cells in mice].

It was shown that low doses of phenozan (10(-17), 10(-14), 10(-11), 10(-5) mol/kg) caused changes in kinetic parameters Vmax, Km of LDG and microviscosity in various ranges of microsomal membranes of brain cells. It is suggested that the effect of phenozan on the structure of bilayer membrane is important for binding LDG with membranes.

[New aspects of of the effects of low intensity radiation].

In paper the new aspects of action regularity of ionizing radiation of low intensity on the biophysical and biochemical characteristics of bio-objects and populations are considered. From the point of view of breaking the connection between occurrence of damages and work of systems of restoration at low intensity irradiation, are described the dose dependence of different types--from threshold up to extreme and a plateau curve, differing among themselves only by a parity of these processes. The features of action of low intensity irradiation on bio-objects and populations--change of structure of a population, sensitivity to action of external stimulus, force of connections between the elements of regulatory systems--allow to consider the low intensity irradiation as the factor capable to cause unpredictable transition of quasistationary systems in new status.

[The characteristics of the biological action of low doses of irradiation].

Biochemical, biophysical and functional properties of the genetic and membrane apparatus of the cell were considered activity and regulatory properties of the membrane and cytosolic enzymes of organs and tissues of mice exposed to radiation in the wide range of doses of 6 to 1800 mGy with the radiation intensity of 4.1 x 10(-3) and 41 x 10(-3) mGy/min. It was shown that the dose-dependence of changes in the investigated properties is of non-linear polymodal (bimodal) nature.

[Structural and biochemical parameters of blood components of mice after gamma irradiation with small doses of different intensity].

The complex study on the low gamma-irradiation on the structural feature of lymphocyte DNA and lipid peroxidation (LPO) regulatory system parameters in mice blood was carried out depending on irradiation intensity. It was found that DNA alkaline elution rate constants, viscosity of the different regions of erythrocyte membranes and LPO products content in mice blood plasma varied nonlinearly depending on dose or dose rate. The proportion of the damage types and the range of the DNA structural changes substantially differ depending on the gamma-irradiation dose and its intensity.

[Effect of the functional groups of tocopherol molecules on lipid viscosity of mitochondria].

The influence of tocopherol and its analogue (oxychroman) on the microviscosity of mitochondrial lipids was studied, using spin labels. The viscosity of the lipid bilayer was shown to enhance with the increase in the antioxidant content in the membrane. Small concentrations of alpha-tocopherol (10(-5)-10(-6) mol/l) were shown to increase, while large concentrations (10(-3)-10(-4) mol/l) decreased the fluidity of the lipid bilayer.