Method of Surgical Treatment of Spine Injury with the Use of Extracorporeal Navigation System Based on Additive Technologies.

We present a method of minimally invasive transcutaneous insertion of screws using a prefabricated extracorporeal navigation system using additive technologies (based on primary data obtained from the DICOM package in multi-detector computed tomography of the affected spine segment) according to the principle of personalized medicine. The method was tested on 10 dogs of different breeds with generally similar mechanism of trauma and typical consequences that led to fracture and dislocation of one of the lumbar vertebrae. In all animals, a positive treatment outcome of different degrees was achieved. Regression of the neurological deficit without significant postoperative inflammatory reaction was noted. The proposed method of treatment reduces the risk of malposition in pedicular and interbody pins and reduces radiation intraoperative exposure.

The effects of silver ions on copper metabolism in rats.

The influence of short and prolonged diet containing silver ions (Ag-diet) on copper metabolism was studied. Two groups of animals were used: one group of adult rats received a Ag-diet for one month (Ag-A1) and another group received a Ag-diet for 6 months from birth (Ag-N6). In Ag-A1 rats, the Ag-diet caused a dramatic decrease of copper status indexes that was manifested as ceruloplasmin-associated copper deficiency. In Ag-N6 rats, copper status indexes decreased only 2-fold as compared to control rats. In rats of both groups, silver entered the bloodstream and accumulated in the liver. Silver was incorporated into ceruloplasmin (Cp), but not SOD1. In the liver, a prolonged Ag-diet caused a decrease of the expression level of genes, associated with copper metabolism. Comparative spectrophotometric analysis of partially purified Cp fractions has shown that Cp from Ag-N6 rats was closer to holo-Cp by specific enzymatic activities and tertiary structure than Cp from Ag-A1 rats. However, Cp of Ag-N6 differs from control holo-Cp and Cp of Ag-A1 in its affinity to DEAE-Sepharose and in its binding properties to lectins. In the bloodstream of Ag-N6, two Cp forms are present as shown in pulse-experiments on rats with the liver isolated from circulation. One of the Cp isoforms is of hepatic origin, and the other is of extrahepatic origin; the latter is characterized by a faster rate of secretion than hepatic Cp. These data allowed us to suggest that the disturbance of holo-Cp formation in the liver was compensated by induction of extrahepatic Cp synthesis. The possible biological importance of these effects is discussed.

Benzene oxidation at diamond electrodes: comparison of microcrystalline and nanocrystalline diamonds.

A comparative study of benzene oxidation at boron-doped diamond (BDD) and nitrogenated nanocrystalline diamond (NCD) anodes in 0.5 M K(2)SO(4) aqueous solution is conducted by using cyclic voltammetry and electrochemical impedance spectroscopy. It is shown by measurements of differential capacitance and anodic current that during the benzene oxidation at the BDD electrode, adsorption of a reaction intermediate occurs, which partially blocks the electrode surface and lowers the anodic current. At the NCD electrode, benzene is oxidized concurrently with oxygen evolution, a (quinoid) intermediate being adsorbed at the electrode. The adsorption and the electrode surface blocking are reflected in the impedance-frequency and impedance-potential complex-plane plots.

Discrimination of apple juice and herbal liqueur brands with solid-state electrodes covered with polyaniline and thiacalixarenes.

Solid-contact ion-selective electrodes based on glassy carbon electrode covered with electropolymerized polyaniline and tetrasubstituted thiacalix[4]arene ionophores with hexyl and o-pyridylamido functional groups at the lower rim have been developed and examined in the discrimination of the brands of apple juices and herbal liqueurs. For this purpose, the liquids tested were diluted and spiked with a constant amount of Fe(3+) ions. The variation of the signal toward Fe(3+) ions was achieved due to their involvement in the reactions with the organic ligands and the antioxidants present. As was shown, the combination of the three electrodes with various receptors makes it possible to predict the brand of apple juices and herbal liqueurs using linear discriminant analysis in 95-100% cases. The discrimination procedure makes it possible to discriminate liquids within 20 min. Besides, the electrodes developed make it possible to detect individual antioxidants (ascorbic, malic, oxalic acids, hydroquinone, and quercetin) in the range from 5.0x10(-6) to 1.0x10(-2) M in direct potentiometric measurements and redox titration.

Wettability of ultrananocrystalline diamond and graphite nanowalls films: a comparison with their single crystal analogs.

Dramatic changes in wettability of diamond and graphite are observed when these materials are prepared in nanostructured forms--undoped and nitrogen-doped ultrananocrystalline diamond (UNCD) films, and graphite nanowalls (GNW), respectively. The nanostructured carbon films were deposited on Si by microwave plasma CVD processes. The advancing contact angle theta for water on hydrogenated undoped UNCD films increases to 106 +/- 3 degrees compared to hydrogenated single crystal diamond (theta = 92 degrees). Nitrogen doping (N2 addition to plasma) during UNCD growth makes the film more hydrophilic. The GNW films exhibited superhydrophobic behavior with theta = 144 +/- 3 degrees for water, which is higher than the contact angle of monocrystalline graphite (the basal plane) by a factor of 1.8. No chemical surface treatment is necessary to achieve such high hydrophobicity, it is accomplished solely by a specific (nanoporous, high aspect ratio) surface morphology with very low free surface energy inherent in it. The wetting behaviour of nanostructured films can be described with the Cassie-Baxter equation for heterophase nanoporous surfaces. Oxidation and hydrogenation of UNCD films make it possible to control theta over a much wider range as compared to a single crystal diamond. The influence of diamond grain size on wetting is considered taking into account the surface treatment. The corresponding variation in surface energy has been determined by the modified Young's equation.

High rate flame synthesis of highly crystalline iron oxide nanorods.

Single-step flame synthesis of iron oxide nanorods is performed using iron probes inserted into an opposed-flow methane oxy-flame. The high temperature reacting environment of the flame tends to convert elemental iron into a high density layer of iron oxide nanorods. The diameters of the iron oxide nanorods vary from 10 to 100 nm with a typical length of a few microns. The structural characterization performed shows that nanorods possess a highly ordered crystalline structure with parameters corresponding to cubic magnetite (Fe(3)O(4)) with the [100] direction oriented along the nanorod axis. Structural variations of straight nanorods such as bends, and T-branched and Y-branched shapes are frequently observed within the nanomaterials formed, opening pathways for synthesis of multidimensional, interconnected networks.

Generation of noninductive current by electron-Bernstein waves on the COMPASS-D Tokamak.

Electron-Bernstein waves (EBW) were excited in the plasma by mode converted extraordinary (X) waves launched from the high field side of the COMPASS-D tokamak at different toroidal angles. It has been found experimentally that X-mode injection perpendicular to the magnetic field provides maximum heating efficiency. Noninductive currents of up to 100 kA were found to be driven by the EBW mode with countercurrent drive. These results are consistent with ray tracing and quasilinear Fokker-Planck simulations.

Interaction of catalytic domains in cytochrome P450scc--adrenodoxin reductase--adrenodoxin fusion protein imported into yeast mitochondria.

We have constructed plasmids for yeast expression of the fusion protein pre-cytochrome P450scc--adrenodoxin reductase-adrenodoxin (F2) and a variant of F2 with the yeast CoxIV targeting presequence. Mitochondria isolated from transformed yeast cells contained the F2 fusion protein at about 0.5% of total protein and showed cholesterol hydroxylase activity with 22(R)-hydroxycholesterol. The activity increased 17- or 25-fold when sonicated mitochondria were supplemented with an excess of purified P450scc or a mixture of adrenodoxin (Adx) and adrenodoxin reductase (AdxRed), respectively. These data suggest that, at least in yeast mitochondria, the interactions of the catalytic domains of P450scc, Adx, and AdxRed in the common polypeptide chain are restricted.

Heterochromatin protein 1 modifies mammalian PEV in a dose- and chromosomal-context-dependent manner.

Locus control regions (LCRs) are gene regulatory elements in mammals that can overcome the highly repressive effects normally associated with heterochromatic transgene locations (for example the centromere) in mice. Deletion of essential LCR sequences renders the cognate gene susceptible to this form of repression, so a proportion of the cells from transgenic mice that would normally express the transgene are silenced-a phenomenon known as position effect variegation (PEV). We show here that PEV can also occur when the transgene is non-centromeric and that the extent of variegation can be developmentally regulated. Furthermore, by overexpressing a mammalian homologue (M31) of Drosophila melanogaster heterochromatin protein 1 (HP1; refs 7,8) in transgenic mouse lines that exhibit PEV, it is possible to modify the proportion of cells that silence the transgene in a dose-dependent manner. Thus, we show M31 overexpression to have two contrasting effects which are dependent on chromosomal context: (i) it enhanced PEV in those lines with centromeric or pericentromeric transgene locations; and (ii) it suppressed PEV when the transgene was non-centromeric. Our results indicate that components or modifiers of heterochromatin may have a chromosomal-context-dependent role in gene silencing and activation decisions in mammals.

Human HMG box transcription factor HBP1: a role in hCD2 LCR function.

The locus control region (LCR) of the human CD2 gene (hCD2) confers T cell-specific, copy-dependent and position-independent gene expression in transgenic mice. This LCR consists of a strong T cell-specific enhancer and an element without enhancer activity (designated HSS3), which is required for prevention of position effect variegation (PEV) in transgenic mice. Here, we identified the HMG box containing protein-1 (HBP1) as a factor binding to HSS3 of the hCD2 LCR. Within the LCR, HBP1 binds to a novel TTCATTCATTCA sequence that is higher in affinity than other recently reported HBP1-binding sites. Mice transgenic for a hCD2 LCR construct carrying a deletion of the HBP1-binding sequences show a propensity for PEV if the transgene integrates in a heterochromatic region of the chromosome such as the centromere or telomere. We propose that HBP1 plays an important role in chromatin opening and remodelling activities by binding to and bending the DNA, thus allowing DNA-protein and/or protein-protein interactions, which increase the probability of establishing an active locus.

Can foreign proteins imported into yeast mitochondria interfere with PIM1p protease and/or chaperone function?

When studying the fate of mammalian apocytochrome P450scc (apo-P450scc) imported in small amounts into isolated yeast mitochondria, we found that it undergoes degradation, this process being retarded if recipient mitochondria are preloaded in vivo (to about 0.2% of total organelle protein) with a fusion protein composed of mammalian adrenodoxin reductase and adrenodoxin (AdR-Ad); in parallel we observed aggregation of apo-P450scc. These effects suggest some overload of Pim1p protease and/or mtHsp70 system by AdR-Ad, as both of them are involved in the degradation of apo-P450scc (see Savel'ev et al. J. Biol. Chem. 273, 20596-20602, 1998). However, under the same conditions AdR-Ad was not able to impede the import of proteins into mitochondria and the development of the mitochondrial respiratory machinery in yeast, the processes requiring the mtHsp70 system and Pim1p, respectively. These data imply that chaperones and Pim1p protease prefer their natural targets in mitochondria to imported foreign proteins.