[Effect of weak static magnetic fields on the excitability of a neuron].

Changes in the excitability of the neuron (amplitude, excitability threshold, rate of action potential transduction), as well as changes in the viscosity of the plasma membrane of the nerve and membranes of subcellular organelles, induced by the action of a weak magnetic field, have been studied by the methods of extracellular registration of membrane potential and combination scattering. It was found that only the threshold of excitability in intact nervous fibers increases by the action of this field. It was proven that the conformation of C40 carotenoids localized not only in plasma membranes but also in subcellular membranes of the neuron changes in a weak magnetic field. It is assumed that the changes in the excitability of the neuron by the action of weak magnetic field are due to changes in the orderliness of membrane lipids and the content of oxygen in the cytoplasm.

Image analysis of bioparticles accumulation and diamagnetic alignment in high-gradient magnetic field.

Magnetic properties of biological particles are measured in high-gradient magnetic separation (HGMS) analysis, revealing the concentrating process of nucleoprotein particles, ferritin, red blood cells, and eggs. A magnetic force acting on micrometer and submicrometer biological particles having diamagnetic or paramagnetic susceptibility with respect to the solution causes their movement and accumulation in gradient magnetic fields dependent on the values of the magnetic moments. The methods developed enable us to obtain the magnetic moments values of single particles and their assembly directly from magnetic separation and image analyses without assuming the detection of sizes. Our precision methods for the measurement of the capture traveling (magnetic diffusion) time and the accumulation (magnetic sedimentation) radius in HGMS show that it is really possible to determine the weak dia- or paramagnetic shifts of magnetic susceptibility up to 0.7x10(-10) (SI units). HGMS analysis of the concentrating process of nucleoprotein granules (microcells, DNA granules, or nucleosome core particles) with polarization microscopy reveals phase transitions for DNA in granules, and separation accumulation of particles enables the determination of the diamagnetic susceptibility and anisotropy properties. Magnetic concentration effects always occur in living systems because micrometer-located gradient magnetic fields inside an organism are strong enough to cause drifts of cellular complexes and organelles of micrometer and submicrometer sizes. We report the appearance of superparamagnetic contamination inside developing shrimp eggs. In the developing shrimps eggs, ferritin aggregates are observed under weak gradient magnetic fields and diaparaferromagnetic changes are detected. A significant interruption of egg development is revealed in such fields.

[Effect of temperature and pH on magnetic properties of human erythrocytes]. / Vliianie temperatury i pH sredy na magnitnye svoistva éritrotsitov cheloveka.

Erythrocytes magnetic susceptibility depending on temperature and pH value of buffer were studied by analysing individual erythrocytes moving in a medium in the nonhomogeneous magnetic field near a transversely magnetized thin wire.

[Magnetic susceptibility and the structure of liposomes]. / Magnitnaia vospriimchivost' i struktura liposom.

Magnetic susceptibility of single liposomes sized 1-10 m was measured. Solid magnetic susceptibility of lipid-egg lecithin equalling chi et = -(5.038 +/- 0.035) X 10(-7) e.m.u./cm3 was determined. The liposome susceptibility was shown to be proportional to the number of bilayers in it and to reflect its packing.

[Theoretical estimation of the effect of magnetic fields on liposome formation]. / Teoreticheskaia otsenka vliianiia magnitnogo polia na formirovanie liposom.

In terms of equilibrium thermodynamics influence of the magnetic field on liposome formation is examined. As a result of the magnetic field influence under ultrasonic effect on water mixture of lipid structure a more homogeneous mixture must be observed due to the limits of vesicules maximum size.

[Changes in the structure of lipid bilayer membranes in magnetic fields]. / Izmeneniia v strukture bisloinykh lipidnykh membran v magnitnom pole.

In terms of structural voluminous phases the structure of bilayer lipid membranes in the constant magnetic field far from the point of phase transition is examined. The field influence on the area of the membrane black part is due to surface tension of voluminous phases. It is noted that the effect is squared with the field and is negative under gomeotropic orientation of the molecules on the surface. The dependence of the effect on temperature is predicted and its possible mechanisms are examined.

[Magnetic susceptibility and magnetic capture of cells]. / Magnitnaia vospriimchivost' i magnitnyi "zakhvat" kletok.

A phenomenon of magnetic capture of human erythrocytes and lymphocytes in paramagnetic and diamagnetic modes of motion near a transversely magnetized wire has been investigated. The values of magnetic susceptibility of numerous individual erythrocytes containing hemoglobin in various forms and lymphocytes were determined using a trajectory analysis. The distribution histograms of erythrocytes in various states and lymphocytes of magnetic susceptibility have been constructed. This histogram for lymphocytes cannot exclude magnetic identification of these cells. The method of determination of physiological concentration of methemoglobin in erythrocytes based on the distribution histogram has been suggested.

[Magnetic susceptibility of single human erythrocytes]. / Magnitnaia vospriimchivost' odinochnykh éritrotsitov cheloveka.

Velocity of movement of a large number of erythrocytes containing different forms of hemoglobin in a homogeneous magnetic field was measured. Distributions of the erythrocytes according to their movement velocity were obtained. Values of magnetic susceptibility were found. For the majority of oxigenized erythrocytes they are -0.75 x 10(-6), for desoxigenized ones -0,46 x 10(-6), for those containing 97% methemoglobin -0,54 x 10(-6). The method of obtaining erithrocytes distribution by their movement velocities in a nonhomogeneous magnetic field is proposed for diagnostical application.

[Effect of a heterogeneous magnetic field on human erythrocytes]. / Deistvie neodnorodnogo magnitnogo polia na éritrotsity cheloveka.

Visual observation was carried out of the effect of heterogeneous magnetic field on human erythrocytes containing both oxi- and methemoglobin, near the surface and end plane of ferromagnetic wire under its transverse and longitudinal magnetization in homogeneous magnetic field of 8.10(5) A/M. Existence of diamagnetic effect in normal erythrocytes and paramagnetic effect on erythrocytes with methemoglobin were shown. Drift rates of separate erythrocytes to the surface and end plane of the wire were measured.