[Investigation of lymphocytes activation using a method of coherent phase microscopy].

Investigation of initial stages of T-lymphocytes activation was performed by coherent phase microscopy (CPM) based on the measurements of phase thickness and diameter of the cell and its organelles. Lymphocytes where activated in two ways: by addition of 2 10-6 g/ml phytohemagglutinin (PHA) and with He-Ne laser (lambda = 633 nm, 10-3 W) radiation. It was shown that phase thickness is proportional to refractivity (difference between refractive indices of an object and the surrounding medium) and geometrical thickness. Phase thickness decreased during activation independently of the nature of the stimuli. Phase thickness in healthy donors was 220 + 60 nm; decreased to 110 + 30 nm 1 h after addition of PHA. The same values were achieved 30 min after stimulation with the He-Ne laser. Characteristic changes in phase thickness in the nucleus and nucleolus were observed after lymphocytes were stimulated with the laser.

[Research on the early stages of spore germination in Bacillus subtilis using dynamic phase microscopy].

The changes in the state of Bacillus subtilis spores that occur during germination were analyzed using dynamic phase microscopy (DPM). DPM is based on monitoring and analyzing the interference image of a specimen in a coherent laser beam. The optical path difference (the phase thickness of the specimen, PT) depends on the geometrical height of the specimen and its refractive index. We demonstrated that the maximum PT value is a convenient criterion of the physiological state of the organism involved: PT is > or = 80 nm, 40-50 nm, and < or = 0 in dormant, developing (initiated), and heat-killed spores, respectively. We established that (i) heating a spore suspension to 40 degrees C results in a reversible twofold decrease (from 80 to 40 nm) in their PT under conditions that do not promote the development of the bacteria; this decrease is irreversible under growth-promoting conditions; (ii) the PT values of germinating spores oscillate with a considerable fluctuation amplitude (up to 7 nm), in contrast to the limited fluctuation amplitude (within 1 nm) in dormant spores; (iii) activated spores were heterogenous with respect to the PT pattern: a majority of the spores exhibited a usual spatial profile (with a maximum thickness in the center), whereas a minor fraction of them were characterized by an erythrocyte-like profile with a concave center; this implies that the central zone of the spore was more rapidly hydrated (with a decrease in refractive index) than the peripheral zone.

[Cooperative processes in mitochondria: registration by dyanmic phase microscopy]. / Kooperativnye protsessy v mitokhondriiakh: registratsiia metodom dinamicheski fazovoi mikroskopii.

The spectra of phase fluctuations in mitochondria were measured by the method of dynamic phase microscopy. Contrasting components were revealed whose intensity markedly changed at distances of 100-300 nm. Similar frequency components were observed in the spectra of ATP-stimulated fluctuations in liposomes with the incorporated ATPase. The values of the frequency and intensity of contrasting components in spectra of liposomes, mitochondria, and cells are presented. The possibility of determining the position of active enzyme complexes from their characteristic frequencies is discussed.

[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.

[Diffusion of a fluorescent probe in egg lecithin multilayers and the effect of a permanent magnetic field]. / Diffuziia fluorestsentnogo zonda v mul'tisloiakh iaichnogo litsetina i vliianie na nee postoiannogo magnitnogo polia.

A method is developed for determining the value of transverse diffusion coefficient through lipid multilayers. Using the absorption kinetics parameters of 1-aniline-8-sulphonate naphthalene (ANS) the value of diffusion coefficient was estimated as Dt = (3 +/- 1). X 10(-12) cm2 s-1 at (22 +/- 0.5) degrees C. The value of Dt was shown to increase under the action of the magnetic field parallel to the multilayer surface; a relative increase of Dt at field 1.3 T is +(40 +/- 15)%.

[Conductivity and structural transitions in bilayer lipid membranes]. / Provodimost' i strukturnye perekhody bisloinykh lipidnykh membran.

5 structural transitions were found in bilayer lipid membranes (BLM) from egg lecithin (EL) within the temperature range 14-44 degrees C. In the transition zone BLM conductivity abruptly increases, in some cases current fluctuations of the order 150 pC of the channel type are initiated. The transition temperatures observed in BLM from EL coincide with those in biological membranes. The cause of this phenomenon is discussed, as well as possible use of these BLM in the region of structural transition as a model of cellular receptor to electromagnetic fields.