[Alternative ways of collateral venous flow in occlusion of superior sagittal sinus].

The authors demonstrated alternative ways of bloodflow from occluded superior sagittal sinus through hypertrophic dural veins (middle meningeal veins) and sphenoparietal sinus. Parameters of bloodflow were evaluated using triplex ultrasonography. The possibility of venous drainage into anterior segment of superior sagittal sinus proximal to the site of occlusion with further retrograde flow towards dural venous anastomosis is verified. Possibilities of spiral CT-venography and standard time-of-flight MR-venography for assessment of collateral venous flow were estimated.

[Effect of growth conditions on electrophysical properties of Rhodobacter capsulatus PG cells].

Electrophysical characteristics of cells of the phototrophic bacterium Rhodobacter capsulatus PG grown in complete Hutner medium in light or dark were found to differ depending on the composition of their lipopolysaccharides (LPS). Under dark cultivation, the cells synthesized LPS with a shortened structure that determined the electrophoretic properties of cell surfaces. The observed decrease in the effective high-frequency electroconductivity of the dark-grown cells is assumed to be due to a decrease in the intracellular K+ concentration resulting from increased permeability of cytoplasmic membranes of the cells grown under these conditions.

[Effects of cellobiose lipid B on Saccharomyces cerevisiae cells: K+ leakage and inhibition of polyphosphate accumulation].

Cellobiose lipid B, a natural fungicide produced by the yeast Pseudozyma fusiformata, induces the leakage of K+ and ATP from cells of Saccharomyces cerevisiae. The presence of glucose decreases the effective concentration of cellobiose lipid B. The concentration of cellobiose lipid B was selected that results in a high rate of K+ leakage and a five- to sevenfold decrease in the intracellular ATP content, while the accumulation of acid-soluble polyphosphates decreased only by half. These results indicate the possibility of synthesis of these polymers independently of the ATP level and of the ion gradient on the plasma membrane.

[The effect of composition of the core region of Escherichia coli K-12 lipopolysaccharides on the surface properties of cells].

The pH dependences of electrokinetic potentials (EKP) of the cells of two Escherichia coli K-12 strains (D21 and JM 103) with known lipopolysaccharide (LPS) core composition have been determined by the method of microelectrophoresis. At pH 4.6-5.2, the negative surface charge of the cells with Re core LPS was reliably higher. It was shown that the interaction of bacteria with lysozyme results in a decrease of optical density of suspensions due to higher sensitivity of the cells with complete LPS core to hypotonic shock. LPS release from bacterial cell wall depended also on bacterial LPS core composition and increased with LPS core extension. Electrokinetic measurements and the study of the interaction of cells with lysozyme suggest that higher negative surface charge of E. coli JM 103 cells (Re type LPS) is associated with higher quantity and density of LPS packing in the cell wall as compared with the cells of E. coli D21 (Ra type LPS).

[Changes of hemo- and liquor-dynamics during intravascular interventions on venous-arterial malformations of the brain].

Changes in the arterial and venous blood flow and liquor-dynamics during intravascular venous-arterial interventions were studied in 30 patients with venous-arterial malformations of the brain. It was found that against the background of reduced venous-arterial shunting no expected drop of pressure in the jugular veins occured. Data were obtained on possible active autoregulation of pressure by the jugular veins. The investigation of pressure in the sinus system of the brain has shown that it correlates with intracerebral and systemic arterial pressure. The results obtained can be used in vascular neurosurgery, anesthesiology and neurology.

[Relations between the chemotype and the cell electrophoretic properties in Rhodobacter capsulatus strains].

The cells of two Rhodobacter capsulatus strains, B10 and PG, and the LPS of their cell walls were studied by electrophysical and biochemical methods. Strain B10 was found to belong to the R chemotype, and strain PG, to the RS chemotype. A relation was revealed between the chemotype of the photosynthesizing bacteria Rhodobacter capsulatus and the electrophoretic properties of their cells.

[On the fluorescence of bidistilled water after electrochemical treatment].

The short-wave fluorescence of bidistilled water treated in the cathode and anode chambers of two types of electrolysers made from different materials was investigated by fluorescence spectroscopy. It was shown that the electrochemical treatment of water did not induce intrinsic short-wave flyorescence of catholyte and anolyte in the case of quartz glass electrolyser. The increase observed in the intensity of intrinsic short-wavelength fluorescence of bidistilled water in the catholyte and anolyte of the electrolyser made from technical organic glass was caused by microcontaminations released from electrolyser material in the samples.

[Effect of an aqueous salt solution exposed to weak magnetic fields on the sensitivity of bacterial plasma membrane to reactive oxygen species]. / Vliianie vodno-solevogo rastvora, obrabotannogo slabymi magnitnymi poliami, na chuvstvitel'nost' bakterial'noi plazmaticheskoi membrany k aktivnym formam kisloroda.

It was shown by electroorientation spectroscopy that hydroxyl radicals OH* generated in a Cu(2+)-ascorbate system disturb the barrier properties of the plasma membrane in Escherichia coli K12 cells. It was also found that in water containing small additions of H+, Na+, and Cl-, preliminarily exposed to weak combined permanent (42 microT) and polyfrequency alternating (amplitude 0.06 microT and frequencies 1, 3.7, and 32.2 Hz) magnetic fields, the sensitivity of the plasma membrane to the radical attack considerably decreased, whereas dimethylsulfoxide did not protect active oxygen species in this system. It was assumed that treating the aqueous solution with magnetic fields affects the oxidation of ascorbate. Spectrophotometric measurements did reveal a decrease in the rate of oxidation of ascorbate by Cu2+ ions in a solution preliminarily treated with magnetic fields.

[Early and late results of the intravascular treatment of cerebral aneurysms with a detachable balloon-catheter]. / Blizhaishie i otdalennye rezul'taty vnutrisosudistogo lecheniia anevrizm golovnogo mozga s pomoshch'iu otdeliaemogo ballon-katetera.

The paper analyzes the outcomes of intravascular treatment in 87 patients with cerebral aneurysms with separable a balloon catheter with a valve device. In the cold and hemorrhagic periods, mortality rates were 6.4 and 40%, respectively. The postoperative follow-ups lasted 1 to 17 years (mean 7.7 years). Recurrent subarachnoidal hemorrhage (SAH) was noted in 6.5% of cases, with not earlier than 4.5 years after intervention. The remaining patients (even with partial aneurysmal occlusion) had no recurrent SAH.

[Prognosis of inhalation-related injuries in accidental release of ammonium and chlorine by the method of dynamic concentration]. / Prognoz ingaliatsionnogo porazheniia cheloveka pri avariinom vybrose ammiaka i khlora metodom dinamicheskoi kontsentratsii.

The article deals with new approaches to evaluate casualty effect of accidental chemical release exemplified by common and dangerous industrial chemicals ammonium and chlorine. Dynamic concentration method considers effects of high concentrations inducing instant reflex cardiac and respiratory arrest as well as lesions caused by variable toxic doses.

[Comparative effectiveness of antioxidants in protecting the bacterial plasmatic membrane from the active froms of oxygen]. / Sravnitel'naia éffektivnost' antioksidantov pri zashchite bakterial'noi plazmaticheskoi membrany ot aktivnykh form kisloroda.

The effect of hydroxyl radicals OH. generated by the decomposition of H2O2 by Fe2+ ions (Fenton reaction) on the barrier properties of plasma membranes of Escherichia coli cells K-12 was studied by electroorientation spectroscopy. It was found that the administration of hydrogen peroxide led to the disturbance of the barrier properties of plasma membranes only when the cells were preincubated with Fe2+ ions and their constant concentration in the system was maintained by ascorbate or dithiotreitol (150-500 microM). The extent of the toxic action on plasma membranes depended on the concentration of reacting elements and the substance used as a reducer Fe2+. The efficiency of protection of antioxidants of different classes (enzymic, SH-containing, and phenolic compounds) against the toxic action of hydroxyl radicals on plasmatic membranes was shown.

[Resistance of certain strains of Pseudomonas bacteria to toxic effect of heavy metal ions]. / Ustoichivost' nekotorykh shtammov bakterii roda Pseudomonas k povrezhdaiushchemu deistviiu ionov tiazhelykh metallov.

The effect of heavy metal cations (cobalt, nickel, and copper) and the anion detergent sodium dodecyl sulfate (SDS) on the barrier properties of the plasma membrane (PM) of the Co-sensitive stain Pseudomonas putida BS394 and the Co-resistant strains Pseudomonas sp. BS501 (wild-type strain) and Pseudomonas putida BS394 (pBS501) (transformed strain) was studied by high-frequency electro-orientational spectroscopy. The cations were found to rank, in order of decreasing damage inflicted on the PM, as copper > cobalt > nickel. The strains studied were found to rank, in order of increasing resistance of the PM to damage inflicted by copper and cobalt cations, as P. putida BS394 < P. putida BS394 (pBS501) < Pseudomonas sp. BS501. In order of increasing resistance to SDS, the strains ranked inversely. The strains did not differ in sensitivity to nickel cations. Investigation of the surface of intact and trypsin-treated cells by microelectrophoresis showed that the surface layers of the cell wall of wild-type and transformed cells contained increased amounts of proteins. The surface proteins of Co-resistant cells had molecular masses of 49, 40, and 32 kDa. Exposure of Co-resistant cells to trypsin considerably reduced their resistance to cobalt cations. It is assumed that the resistance of the PM of the wild-type and transformed pseudomonads to heavy metal cations is determined by plasmid pBS501 and is related to the synthesis of protective surface proteins of the cell wall.

[Study of the interaction of MTPN11 mycobacteriophage with host cells based on electron microscopy, fluorimetry, and electro-oriented spectroscopy]. / Izuchenie vzaimodeistviia mikobakteriofaga MTPN11 s kletkoi-khoziainom na osnove élektronnoi mikroskopii, fluorimetrii i élektro-orientatsionnoi spektroskopii.

According to electron-microscopic data, various cells in the M. smegmatis ATCC607 population interact differently with phage MTPH11. Fluorometric studies of phage-host interactions were performed using a membranotropic fluorescent probe, 8-anilino-1-naphthalene sulfonate (ANS). Changes in the electric characteristics of mycobacterial cells infected with the phage were studied by electro-orientational (EO) spectroscopy. The problem of the employment of fluorometry and EO spectroscopy for rapid phage typing of mycobacteria is discussed.

[Toxic effect of hydroxylated ions of heavy metals on the cytoplasmic membrane of bacterial cells]. / Toksicheskoe deistvie gidroksilirovannykh ionov tiazhelykh metallov natsitoplazmaticheskuiu membranu bakterial'nykh kletok.

The influence of nickel, copper, cadmium, and lead ions at concentrations of 50 to 100 microM on the barrier properties of the plasma membrane (PM) and the electrophoretic mobility (EPM) of Pseudomonas fluorescens 71, Escherichia coli K-12, and Mycobacterium phlei B-1291 VKM cells was studied at pH values from 5 to 9 by electro-orientational (EO) spectroscopy and microelectrophoresis of cells. According to the data of EO spectroscopy, the increase in the toxicity of heavy metal cations to cells corresponded to transition of cations to monovalent hydroxylated forms. Hydroxylated ions were found to more easily adsorb on, or penetrate across, the PM and to bind to competent proteins. During the treatment of all three investigated microorganisms with Cu and Pb ions, and gram-negative bacteria also with Ni ions, the EPM of cells changed in a pH range corresponding to the transition of bivalent metal ions to their monovalent hydroxylated forms. Changes in the EPM induced by increasing pH correlated well with the enhanced toxicity of these metals to the PM, as evidenced by the EO spectroscopy data. At the same time, this correlation was less pronounced for cadmium sulfate toxicity to all of the microorganisms studied and for nickel chloride toxicity to M. phlei cells.

[Effect of cell wall polyphosphates on the sensitivity of the yeast Saccharomyces carlsbergensis to the damaging action of cetyltrimethylammonium bromide]. / Issledovanie vliianiia polifosfatov kletochnoi obolochki na chuvstvitel'nost' drozhzhei Saccharomyces carlsbergensis k povrezhdaiushchemu deistviiu tsetiltrimetilammonii bromida.

The effect of cetyltrimethylammonium bromide (CTAB) on Saccharomyces carlsbergensis cells grown in orthophosphate-containing medium and on cells starved of phosphorus was studied by electroorientation spectroscopy. CTAB (20 microM) was found to substantially damage the plasma membrane (PM)) of cells grown in the presence of orthophosphate, while cells starved of phosphorus were damaged to a lesser extent. Biochemical analysis of the content of inorganic polyphosphate (poly(P(i))) in the cells, as study of their capacity to adsorb 9-aminoacridine, a fluorescent cationic dye, suggested that the different sensitivity of the plasma membrane to CTAB was due to differences in the content of polyanionic molecules of poly(P(i)) in the cell wall and consequent differences in its net negative charge. Magnesium cations increased the time of CTAB penetration through the cell wall and reduced the damage inflicted on the PM.

[Electrophysical analysis of Escherichia coli cell damage caused by silver ions]. / Elektrofizicheskii analiz povrezhdeniia bakterial'nykh kletok Escherichia coli ionami serebra.

The influence of Ag+ (0.5-10 microM) on Escherichia coli K-12 cells was studied by electrophoresis and electro-orientation spectroscopy methods. It was shown that the pH-dependency of the cell electrokinetic potential (phosphate-citrate buffer with ion strength 0.02) practically didn't changed after Ag+ treatment, but in low-conductive media electrophoretical mobility of intact and inactivated by heat (70 degrees, 15 min) cells gradually decreased as the Ag+ concentration increased. It was due to the Ag+ adsorption on the cell surface and could not be used for the definite characterization of the cell damage. The high-frequency decrease in the cell electro-orientation spectrum shifted to the region of lower frequencies, K+ was excreted by cells, slight raise of the medium pH occurred and significant changes of cell osmotic properties were observed as a result of Ag+ action. All these changes showed the disturbance of barrier properties of the cytoplasmic membrane. Besides the damaging action of Ag+ on cell membranes increased with the decrease of pH and decreased after the addition of Mg2+, Ca2+ and Sr2+ in low concentrations.

[Electrophysical analysis of the damage of Escherichia coli outer membrane]. / Elektrofizicheskii analiz povrezhdeniia vneshnei membrany kletok Escherichia coli.

The method of electro-orientational spectroscopy was used to study the damaging action of SDS and Triton X-100 on Escherichia coli cells in which the barrier properties of the outer membrane were impaired by treatment with Triton B (10(-2) M Tris-HCl buffer, pH 8.0) and a heat shock (47 degrees C, 15 min). When either SDS (10(-4)-2.10(-4) M) or Triton X-100 (10(-4)-10(-3) M) was added to such cells, the high-frequency region of their electroorientational spectrum was found to undergo considerable changes. The mode of these changes indicated that the barrier properties of cell cytoplasmic membranes were damaged. These changes were not detected in the case of intact cells. Changes in the low-frequency region of the spectra for intact and damaged cells stemmed from the adsorption of these surfactant molecules on the cell surface.

[Relation between the damaging effect of surface-active compounds on Escherichia coli cells and the phase of culture growth]. / Zavisimost' povrezhdaiushchego deistviia poverkhnostno-aktivnykh veshchestv na kletki Escherichia coli ot fazy rosta kul'tury.

The techniques of cell electrophoresis and electro-orientation spectroscopy were used to study the effect of sodium dodecyl sulfate (SDS) and cetyl trimethyl ammonium bromide (CTAB) on Escherichia coli K-12 cells from the culture at the exponential and stationary growth phases. SDS (2 x 10(-4) M) considerably damaged cells at the exponential phase, particularly at pH less than 6.0, whereas cells at the stationary phase were damaged to a less degree and only at pH less than 5.3 or after their treatment with Trilon B. The damaging effect of SDS decreased in an isotonic medium (0.25 M sucrose) as compared to a hypotonic medium (distilled water). CTAB also damaged cells at the exponential phase more than those at the stationary phase, and its damaging action decreased with pH. Mg2+, Ca2+, and Sr2+ cations diminished the degree of cell damage with CTAB, but did not exert any noticeable protection in the case of SDS. The different sensitivity of cells at the exponential and stationary growth phases may be associated with changes in their surface electric charge and with the existence of hydrophobic regions on the cell surface. The higher electric charge of cells at the stationary growth phase is presumed to stem from a rise in the amount of surface lipopolysaccharides which bear a negative electric charge.