[APPLICATION OF MINIINVASIVE INTERVENTIONS UNDER ULTRASONOGRAPHIC CONTROL FOR NONPARASITIC HEPATIC CYSTS].

The results of treatment of 21 patients, suffering nonparasitic hepatic cysts, using laparoscopic draining and puncture under ultrasonographic control, were analyzed. Minimal traumaticity of the intervention, absence of necessity to apply general anesthesia, low rate of postoperative morbidity (7.1%), reduction of duration of the patients stationary treatment down to (3.3 ± 0.61) days, reduction of economic wastes on the treatment constitute the advantages of such method.

Optical Kerr phase shift in a nanostructured nickel-doped zinc oxide thin solid film.

The optical Kerr effect exhibited by a nickel doped zinc oxide thin solid film was explored with femto- and pico-second pulses using the z-scan method. The samples were prepared by the ultrasonic spray pyrolysis technique. Opposite signs for the value of the nonlinear refractive index were observed in the two experiments. Self-defocusing together with a two-photon absorption process was observed with 120 ps pulses at 1064 nm, while a dominantly self-focusing effect accompanied by saturated absorption was found for 80 fs pulses at 825 nm. Regarding the nanostructured morphology of the resulting film, we attribute the difference in the two ultrafast optical responses to the different physical mechanism responsible of energy transfer generated by multiphoton processes under electronic and thermal effects.

Ultrafast nonlinear optical response of photoconductive ZnO films with fluorine nanoparticles.

The absorptive and refractive third order nonlinear optical properties exhibited by a ZnO thin solid film with fluorine nanoparticles were studied with picosecond and femtosecond pulses using different techniques. We were able to evaluate the photoconductivity of the material and the quenching of the induced birefringence observed in the presence of two-photon absorption. The samples were prepared by a chemical spray deposition technique. In order to investigate the different contributions of the third order nonlinearities of the film, we analyzed the vectorial self-diffraction effect and the optical Kerr transmittance observed in the sample. A dominantly absorptive nonlinearity was measured at a 532 nm wavelength with 50 ps pulses, while nonlinear refraction was found to be negligible in this regime. On the other side, a pure electronic refractive third order nonlinearity without the contribution of nonlinear absorption was detected at 830 nm with 80 fs pulse duration. A quasi-instantaneous optical response and a strong enhancement in the ultrafast nonlinear refraction with the inhibition of the picosecond two-photon absorption mechanism were measured for the case of the femtosecond excitation.

Absorptive and refractive nonlinearities by four-wave mixing for Au nanoparticles in ion-implanted silica.

We report a theoretical and experimental study on the real and imaginary part of the third-order nonlinear optical susceptibility at 532 nm and 7 ns pulse for high-purity silica samples containing Au nanoparticles prepared by ion implantation. We present a method for measuring the magnitude and sign of refractive and absorptive nonlinearities based on four-wave mixing (FWM). This method is derived from a comparison of the light intensities of incident and self-diffracted polarized waves. In the nanosecond regime the samples exhibit saturable absorption and it seems that a thermal effect is the mechanism responsible of nonlinearity of index.

Prednisolone and vitamin D(3) modulate oxidative metabolism and cell death pathways in blood and bone marrow mononuclear cells.

The study was designed to evaluate reactive oxygen species (ROS)/nitric oxide (NO) formation and apoptotic/necrotic cell death elicited by prednisolone in peripheral blood and bone marrow mononuclear cells and to define the efficacy of vitamin D3 to counter glucocorticoid (GC)-induced changes. It was shown that prednisolone (5 mg per kg of female Wistar rat's body weight for 30 days) evoked ROS and NO overproduction by blood mononuclear cells (monocytes and lymphocytes) that correlated with increased cell apoptosis and necrosis. In contrast, prednisolone did not affect ROS/NO levels in bone marrow mononuclear cells that corresponded to lower level of cell death than in the control. Alterations of prooxidant processes revealed in mononuclear cells and associated with GC action were accompanied by vitamin D3 deficiency in animals, which was assessed by the decreased level of blood serum 25-hydroxivitamin D3 (25OHD3). Vitamin D3 administration (100 IU per rat daily for 30 days, concurrently with prednisolone administration) completely restored 25OHD3 content to the control values and significantly reversed ROS and NO formation in blood mononuclear cells, thus leading to decreased apoptosis. In bone marrow, vitamin D3 activated ROS/NO production and protein nitration that may play a role in prevention of prednisolone-elicited increase in bone resorption. We conclude that vitamin D3 shows a profound protection against GC-associated cellular damage through regulating intracellular ROS/NO formation and cell death pathways.

Vectorial two-beam coupling with arbitrary shifted photorefractive gratings: an analytical approach.

An analytical solution is presented to the vectorial coupled wave equations for the steady state amplitudes of two waves interacting in cubic photorefractive crystals. The solution accounts for pump depletion as well as an arbitrary phase shift between the interference pattern and photorefractive grating. It is shown that bidirectional vectorial amplification and polarization orthogonalization of the interacting beams take place in photorefractive crystal with diffusion, drift or mixed mechanism of space-charge formation.

Synergetic theory for a jamming transition in traffic flow.

The theory of a jamming transition is proposed for the homogeneous car-following model within the framework of the Lorenz scheme. We represent a jamming transition as a result of the spontaneous deviations of headway and velocity that is caused by the acceleration/braking rate to be higher than the critical value. The stationary values of headway and velocity deviations and time of acceleration/braking are derived as functions of control parameter (time needed for car to take the characteristic velocity).

[Effect of cytoskeleton-disrupting on the redistribution of the surface receptors of cultured cells]. / Vliianie agentov, razrushaiushchikh tsitoskelet, na pereraspredelenie poverkhnostnykh retseptorov kul'tiviruemykh kletok.

The capacity of cap-formation in cultured cells was shown to increase from 2 to 20 fold upon treating them with ligands in the presence of a conditioned medium. This permitted us to compare the influence of cytoskeleton-disrupting agents on the process of cap-formation in cultured cells of different origin. Cytochalasin was shown to inhibit cap-formation, induced with concanavalin A or anti-H2-serum, both in cells of lymphoid and fibroblastic origin. In contrast, vinblastin did not inhibit cap-formation in cells of lymphoid origin, but caused inhibition in cells of fibroblastic origin twice as strong as did cytochalasin B.

[Ability to redistribute surface receptors in transplantable cell lines]. / Sposobnost' k pereraspredeleniiu poverkhnostnykh retseptorov u kletok perevivaemykh linii.

The ability of cultured lymphoid, erythroid and fibroblastic cells for ligand-induced redistribution of their surface receptors proved to be lower than that of lymphocytes. The process of surface receptors redistribution can be inhibited by low temperature and sodium azide in all the cells under study. Pretreatment with trypsin increased the ability for redistribution of surface receptors in some types of cultured cells, but had no such effect on lymphocytes. These differences between lymphocytes and cultured cells seem to be due to differences in organization of the surface and contractile systems of the respective cells.

[Changes in the cell cycle duration and karyotype of murine L cells with a shift in the mode of cultivation]. / Izmeneniia prodolzhitel'nosti kletochnogo tsikla i kariotipa Kletok L myshi pri smene sposoba kul'tivirovaniia.

A suspension subline LS of mouse fibroblasts L was adapted to the growth in monolayer (LSM subline). The duration of cell cycle and its phases was determined for both the sublines synchronized by a double thymidine block. The duration of cell cycle for LS cells is 17.0 hours, with G1, S and G2 + M being 8.8, 6.3 and 1.8 hours, resp., for LSM cells corresponding values being 31.6, 15.6, 11.0 and 4.8 hours. The karyotype of LSM cells differs from that of LS cells only slightly: there is a redistribution between the numbers of cells with 55 and 56 chromosomes, and a decrease in the number of polyploid cells from 2.0 till 0.2%. The data obtained indicate the heterogeneity of the L line culture which contains cells with long and short cycles. Depending on the mode of cultivation (suspension or monolayer), there is a certain predominance of population either with short or with long cell cycle.

[Dependence of the redistribution of ligand-receptor complexes in cultured cells on the type of growth and on the cell cycle phase]. / Zavisimost' pereraspredeleniia ligand-retseptornykh kompleksov u kul'tiviruemykh kletok ot tipa rosta i fazy kletochnogo tsikla.

The process of active redistribution of ligand-receptor complexes on the surface of both suspension (LS) and adapted for growing in monolayer (LMS) sublines of mouse fibroblasts L was studied. The binding of ligands to its specific receptors on the surface of the LS cells induced an accumulation of ligand-receptor complexes on one pole of a cell with the formation of a typical cap. Under the same conditions in the LSM cells the cleaning of processes and lamello-plasma surfaces from the ligand-receptor complexes was registered. The binding of ligands to the surface of the LSM cells, detached with EDTA, induced the same capping process, as in the case of the LS cells. No differences were found in the redistribution capacity of the ligand-receptor complexes in synchronized cultures of the LS and LSM cells in the G1 and S phase of the cycle. But such a redistribution was not registered on the surface of cells in metaphase and anaphase. The accumulation of ligand-receptor complexes was found in the region of cleavage between daughter cells in telophase. These results are in a good agreement with the well-known data on the changes in the cytoskeleton organization during transition from a monolayer to a suspension state and during mitosis.

[Characteristics of the structural organization of the cytoskeleton in suspension and monolayer sublines of mouse fibroblasts depending upon the type of growth in culture]. / Osobennosti strukturnoi organizatsii tsitoskeleta kletok suspenzionnoi i monosloinoi sublinii fibroblastov myshi v zavisimosti ot tipa rosta v kul'ture.

In attached cells, the main part of filaments is localized in submembrane area, whereas suspension fibroblasts are situated deeper in the cytoplasm. Another difference involves the form of filament gatherings. In the former these are bundles stretched parallel to the cell surface, whereas in the latter these gatherings are in the form of loose balls near the nucleus. According to their diameter and type of cell localization the latter filaments are similar to intermediate ones. In suspension cells with caps formed by ligand treatment, gatherings of fibrillar elements are observed within the cytoplasm but these filaments are shorter and looser, being located in disorder. In addition, the increase in the number of electron dense granules of unknown nature is observed between these filaments. The above observations suggest that the surface processes may be associated with the inner parts of cytoskeleton.

[Cytological and biochemical indices of induced sputum in patients with bronchial asthma and chronic obstructive bronchitis]. / Nekotorye tsitologicheskie i biokhimicheskie pokazateli indutsirovannoi mokroty u bol'nykh bronkhial'noi astmoi i chronicheskim obstruktivnym bronkhitom.

The aim of our research was to study the apoptotic index and the representativeness of CD95-receptor in the effector cells, in addition to estimation of the content of tumor necrosis factor-alpha in the induced sputum supernatant observed in patients with bronchial asthma and chronic obstructive bronchitis. These indices were evaluated in the disease dynamics and involves various treatment programs. The object of our research was induced sputum. The analysis has proven that apoptotic index of effector cell nuclei, representativeness of CD95-receptor and the content of tumor necrosis factor-alpha in the induced sputum differed, respectively, in patients with bronchial asthma and chronical obstructive bronchitis, and depended on the period of disease and employed treatment. The induced sputum analysis results can be used for the airway inflammation activity monitoring, with regard to these diseases and to treatment efficiency monitoring.

[Electron microscopic analysis of lymphocyte fibrillar elements during the redistribution of surface receptors]. / Elektronno-mikroskopicheskii analiz fibrilliarnykh élementov limfotsitov v protsesse pereraspredeleniia poverkhnostnykh retseptorov.

Filaments 5 nm thick, located throughout the cytoplasm mainly along the surface, are observed in intact lymphocytes. In the control glycerinized lymphocytes, besides the above filaments aggregations of filaments nearly 3 nm in diameter were found. After the treatment of cells by antimurine serum or ferritin-conjugated concanavalin A, some fibrillar structures are observed mainly in the cap region in the form of filaments 5-6 nm of thickness, radially directed towards the plasma membrane. After glycerinization, three types of filaments are observed being, respectively, near 3, 5-6 and almost 8 nm in diameter. Two latter types of filaments are decorated by S1-myosine fragments which indicates their actine nature. Differences in the character and distribution of myofibrils in the cytoplasm of intact cells and cells with caps may witness in favour of their involvement in the processes associated with redistribution of surface receptors.

[Role gene expression changes in development of human brain gliomas]. / Rol' izmenenii ékspressii genov v razvitii gliom golovnogo mozga cheloveka.

The identification and characterization of genes either induced or repressed in human brain tumors are important in understanding the mechanism of tumor initiation and progression, stages of malignancy, in developing new approaches to the diagnosis and treatment of tumors. In this paper, differential hybridization of arrayed human fetal brain and postnatal brain and postnatal brain cDNA libraries revealed differences in the rate of hybridization signals with total cDNA probes of the human brain and glioblastoma multiforme for more than 150 cDNA clones. Sixteen nucleotide sequences with changed contents in tumors were identified by repeated differential hybridization of the cDNA clones selected by primary screening with the same total cDNA probes of the human brain and glioblastoma multiforme and by Northern-hybridization of RNA samples from the human and glial tumors. The results of an analysis of the increased expression of the gene encoding apolipoprotein E. DNA-binding protein B, mitochondrial (16S and 12S) and cytoplasmic 28S rRNAs, Alu-containing transcripts, inactivation of cullin 1 gene and potential tumor suppressor gene TSC-22 are described.

[The ROS-generating and antioxidant systems in the liver of rats treated with prednisolone and vitamin D3].

The mechanisms of glucocorticoid-induced disturbances of liver function is currently not fully clarified. Vitamin D3 was previously shown to play an important role in the regulation of impaired oxidative metabolism and detoxification function of the liver associated with the effects of hepatotoxic compounds. The study was undertaken to define the intensity of oxidative metabolism in the rat liver and survival of hepatocytes after prolonged prednisolone administration and to assess whether vitamin D3 is capable to counter glucocorticoid-induced changes. It has been shown that prednisolone (0.5 mg per animal for 30 days) leads to 1.6-fold increase in the percentage of necrotic cells among isolated hepatocytes as compared with the control. The glucocorticoid-induced impairment of hepatocellular function was accompanied by enhanced generation of reactive oxygen species (ROS), accumulation of TBA-active products and carbonylated proteins but reduced levels of free SH-groups of low molecular weight compounds. It was demonstrated a decrease in the activities of key enzymes of antioxidant system (SOD, catalase, glutathione peroxidase), whereas the activities of pro-oxidant enzymes NAD(P)H-quinone oxidoreductase and semicarbazide-sensitive amine oxidase were shown to be increased. Vitamin D3 (and to greater extent in combination with α-tocopherol) administration (100 IU) on the background of glucocorticoid therapy caused normalizing effects on the level of ROS formation, oxidative modification of biomolecules and activity of antioxidant enzymes resulting in better survival of hepatocytes. These data suggest a potential role of vitamin D3 in the regulation of oxidative metabolism alterations related to hepatotoxic action of glucocorticoids.

[Cholecalciferol hydroxylation in rat hepatocytes under the influence of prednisolone].

Glucocorticoid therapy is accompanied by development of processes typical of steroid osteoporosis. Indirect effects of glucocorticoids on the bone tissue are due to changes in mineral metabolism, which is regulated by vitamin D3. In this connection, we studied the influence of prednisolone on cholecalciferol metabolism. The study has shown that prednisolone action causes impairment of cholecalciferol metabolism in hepatocytes due to inhibiting vitamin D3 25-hydroxylase activity. Microsomal (CYP2R1) and mitochondrial (CYP27A1) isoenzymes of vitamin D3 25-hydroxylase were found to function at different concentrations of the substrate. The relative protein contents of the isoenzymes greatly differed in the liver with the prevalence of CYP27A1 over CYP2R1. Prednisolone administration resulted in the lowering of both mitochondrial and microsomal isoenzymes of vitamin D3 25-hydroxylase. The inhibition of vitamin D3 25-hydroxylating system in hepatocytes contributed to a significant reduction in blood serum 25OHD3.

[Features of cholecalciferol hydroxylation in the liver of rats in conditions of D-hypervitaminosis and activity of alpha-tocopherol].

It is shown, that hepatocytes contain two (microsomal and mitochondrial) vitamin D3 25-hydroxylase enzymes, which differ as to their activity and function with maximal activity at different concentrations to substrate, namely at 15 microM and 100 microM of vitamin D3, accordingly. Activity of vitamin D3 25-hydroxylase enzymes of hepatocytes is regulated by cholecalciferol and alpha-tocopherol. The general and microsomal vitamin D3 25-hydroxylase enzymes activity of hepatocytes is lowered, but mitochondrial isoform is increased under D-hypervitaminosis conditions. Vitamin E increases microsomal vitamin D3 25-hydroxylase activity and decreases mitochondrial isoform activity of rats hepatocytes under D-hypervitaminosis conditions. It is established that D-hypervitaminosis is accompanied by expressed hypercalcemia and hyperphosphatemia, by decreased contents of mineral components in the bone tissue and high activity of alkaline phosphatase in the blood serum. The physiological doses of vitamin E under these conditions normalized the mineral metabolism, contents of calcium, phosphates and activity of alkaline phosphatase isoform in the blood serum.

[Role of vitamin E in regulation of cholecalciferol hydroxylation in hypovitaminosis D and hypervitaminosis D].

It is established, that dose-dependent influence of vitamin E on vitamin D3 metabolism, is conditioned by degree of cholecalciferol sufficiency. Under a condition of D-hypovitaminosis, contents of 25OHD3 in blood serum is 2-fold reduced and vitamin D3 25-hydroxylase enzymes activity increased in rat hepatocytes. Vitamin E (0.726-7.26 IU) significantly stimulated the effect of vitamin D3 (40 IU) in animals with D-hypovitaminosis and led to further increase of 25OHD3 content in the blood serum and activity of vitamin D3 25-hydroxylase enzymes in hepatocytes. In D-hypervitaminosis the contents of 25OHD3 in blood serum was more than 3-fold increased and vitamin D3 25-hydroxylase enzymes activity was inhibited. Vitamin E (0,726-7,26 IU) lowered the vitamin D toxicity, decreased contents of 25OHD3 in blood serum and activity of vitamin D3 25-hydroxylase enzymes in hepatocytes. High doses of vitamin E (36.3 IU) under these conditions demonstrated negative effect on vitamin D3 metabolism. The mechanism of vitaminE participation in the vitamin D3 metabolism under D-hypovitaminosis and D-hypervitaminosis may be its influence on the activity of different vitamin D3 25-hydroxylase systems of hepatocytes.

Bidirectional vectorial light amplification in cubic crystals with unshifted photorefractive gratings.

We present a new method of light amplification based on vectorial two-wave mixing in cubic crystal via an unshifted photorefractive grating. The energy transfer between interacting waves is achieved in an experimental configuration that provides the amplitudes of modulation of refractive indices of opposite signs, Dn(1)=-Dn(2), for two orthogonal polarization modes of the interacting waves. The configuration demonstrates bidirectional amplification; i.e., the weak wave is always amplified, independent of its direction with respect to the strong pump beam. We present the results of numerical analysis along with the experimental results for a Bi(12)TiO(20) crystal with a dc applied electric field.