Some aspects of avian flu in the Tyumen region

The list of the actions spent in the summer of 2005 in territory of the Tyumen region, in connection with a destruction of wild birds and poultry from the avian flu is submitted. Except for the quarantine and other sanitary-epidemic measures warning drift of a avian influenza virus in facilities, it is carried out of serological monitoring among workers of poultry-farming facilities and the population of the struck settlements on presence of antibodies to an influenza A (H5N1) virus. Taking into account ways of migration of a wild waterfowl in this territory, probability of contact to it and risk of infection of people, the conclusion about necessity of continuation the monitoring behind circulation of an avian influenza virus in region is made.     

Synthesis and investigation of spectral and electrochemical properties of alkyl-substituted planar binuclear phthalocyanine complexes sharing a common naphthalene ring

Hexa-tert-butyl and dodeca-n-butyl-substituted planar binuclear phthalocyanines sharing a common naphthalene ring with Mg as a central metal were synthesized with high yields and characterized by UV/Vis spectra, luminescence spectra, NMR, electrochemical, and spectroelectrochemical measurements. On the base of these complexes, the metal-free phthalocyanine ligands and the series of binuclear phthalocyanine complexes of rare earth elements (REE) were synthesized.All compounds obtained revealed an intensive near IR-absorption reaching 855 nm for trinuclear phthalocyanine. A crucial increase in NMR spectra resolution was achieved by the addition of ethylene glycol as a disaggregating agent. Spectroelectrochemical measurements during oxidation showed reversible changes of absorbance at 709 and 800 nm.     

Evidence of <Emphasis Type="Italic">Babesia microti</Emphasis> infection in multi-infected <Emphasis Type="Italic">Ixodes persulcatus</Emphasis> ticks in Russia

To detect Babesia-infected Ixodes persulcatus Shulze in a suburb of St. Petersburg, Russia, 738 adult ticks were studied using Babesia specific primers and PCR techniques. The entire sample (more than 1,200 individuals) was screened for the presence of Borrelia spp., Ehrlichia spp. and tick-borne encephalitis virus (TBEV). All 7 ticks infected with Babesia microti, were also infected with other pathogens (all 7 among 417 infected ticks, zero amongst the remaining 321 naive ones (χ² = 5.25, p < 0.05). Babesia microti occurred twice with Borrelia afzelii, 3 times with Borrelia garinii, once with both, and once with both B. garinii and TBEV. The prevalence of infection with Borrelia spp. was 34.0%, with Ehrlichia spp. 6.2%, with TBEV 1.5%, and with Ba microti 0.9%. Babesia microti infection was not found in combination with Ehrlichia sp. or Borrelia burgdorferi sensu stricto. The latter pathogen (prevalence 2.6%), just like Ba. microti, was not encountered as a monoinfection. The data suggest that Ba. microti infection can only survive in I. persulcatus in combination with Borrelia spp. (7 of 7 infections). The disease in humans is more severe and longer-lasting when more than one pathogen is involved. Our observations show that the well known St. Petersburg focus of tick-borne encephalitis and Lyme disease is also a focus of ehrlichiosis and babesiosis. This revised version was published online in July 2006 with corrections to the Cover Date.     

Microorganisms in heat supply lines and internal corrosion of steel pipes

In laboratory experiments with batch cultures of thermophilic microorganisms isolated from urban heat supply systems, the growth of sulfate-reducing, iron-oxidizing, and iron-reducing bacteria was found to accelerate the corrosion rate of the steel-3 plates used in the pipelines. In the absence of bacteria and dissolved oxygen, minimal, corrosion was determined. The aforementioned microorganisms, as well as sulfur-oxidizing bacteria, were found to be widespread in water and corrosion deposits in low-alloy steel pipelines (both delivery and return) of the Moscow heat networks, as well as in the corrosion deposits on the steel-3 plates in a testing unit supplied with the network water. The microorganisms were found in samples with water pH ranging from 8.1 to 9.6 and a temperature lower than 90 degrees C. Magnetite, lepidocrocite, goethite, X-ray amorphous ferric oxide were the corrosion products identified on the steel-3 plates, as well as siderite, aragonite, and S0. The effect of microbiological processes on the rate of electrochemical corrosion was evaluated from the accumulation of corrosion deposits and from variation in total and local corrosion of the steel plates in a testing unit.     

Oxidative stress and antioxidant cell protection systems in the microaerophilic bacterium Spirillum winogradskii

The influence of oxygen availability during cultivation on the biosynthetic processes and enzymatic activities in the microaerophilic bacterium Spirillum winogradskii D-427 was studied, and the roles played by different systems of the defense against oxidation stress were determined. The metabolic adjustments caused by transition from microaerobic (2% O2) aerobic conditions (21% O2 of the gas phase) were found to slow down constructive metabolism and increase synthesis of exopolysaccharides as a means of external protection of cells from excess oxygen. This resulted in a twofold decline of the growth yield coefficient. Even though the low activity of catalase is compensated for by a multifold increase in the activities of other cytoplasmic enzymes protecting from toxic forms of O2--peroxidase and enzymes of the redox system of glutathione (glutathione peroxidase and glutathione reductase)--massive lysis of cells starts in the mid-exponential phase and leads to culture death in the stationary phase because of H2O2 accumulation in the periplasm (up to 10 micrograms/mg protein). The absence in cells of cytochrome-c-peroxidase, a periplasmic enzyme eliminating H2O2, was shown. It follows that the major cause of oxidative stress in cells is that active antioxidant defenses are located in the cytoplasm, whereas H2O2 accumulates in the periplasm due to the lack of cytochrome-c-peroxidase. The addition to the medium of thiosulfate promotes elimination of H2O2, stops cell lysis under aerobic conditions, lends stability to cultures, and results in a threefold increase in the growth yield.     

Quantitative assessment of EB strain cell death in an aerosol and following rehydration]

The authors assessed quantitatively inactivation of lyophilized cells of EB strain by the action of aerosol stress and rehydration using the method of bacterial nucleoide staining. With the advance of dust aerosol "ages" microbial sensitivity to rehydration increased and to the action of aerosol stress--decreased. The method can be used to calculate the aspiration dose in aerogenic vaccination and also to assess the efficacy of lyophilized bacteria restoration.     

Change in the correlation of 2 RNA precursor synthesis pathways in the tissues of animals with rapidly growing hepatomas]

In the spleen, thymus and liver of mice and rats carrying transplantable rapidly growing hepatomas a shift between the de novo and "salvage" pathways of the pyrimidine RNA nucleotides synthesis in favour of the de novo one was observed. The phenomenon was found to be the manifestation of a drastically diminished uridine utilization by the host tissues, this precursor being preferentially and avidly used by the tumour for its own RNA synthesis. The above findings are regarded as the result of a successful competition of the tumour with the host tissues for vital metabolites representing one of the forms of the systemic effects of malignant neoplasms.     

Characteristics of morphology and ultrastructure of bacteria of the genus Dethiosulfovibrio

Cell morphology and fine structure were studied in two strains of rod-shaped, strictly anaerobic, gram-negative sulfidogenic bacteria: strain SR12T (DSM 12538) and strain WS100 (DSM 12537) belonging to "Dethiosulfovibrio starorussensis." Cells of both strains, as well as cells of the type species of the genus Dethiosulfovibrio, D. peptidovorans, were found to possess multiple intracellular incomplete cross septa in the stationary growth phase.     

The structure of cyclin E1/CDK2: implications for CDK2 activation and CDK2-independent roles

Cyclin E, an activator of phospho-CDK2 (pCDK2), is important for cell cycle progression in metazoans and is frequently overexpressed in cancer cells. It is essential for entry to the cell cycle from G0 quiescent phase, for the assembly of prereplication complexes and for endoreduplication in megakaryotes and giant trophoblast cells. We report the crystal structure of pCDK2 in complex with a truncated cyclin E1 (residues 81-363) at 2.25 A resolution. The N-terminal cyclin box fold of cyclin E1 is similar to that of cyclin A and promotes identical changes in pCDK2 that lead to kinase activation. The C-terminal cyclin box fold shows significant differences from cyclin A. It makes additional interactions with pCDK2, especially in the region of the activation segment, and contributes to CDK2-independent binding sites of cyclin E. Kinetic analysis with model peptide substrates show a 1.6-fold increase in kcat for pCDK2/cyclin E1 (81-363) over kcat of pCDK2/cyclin E (full length) and pCDK2/cyclin A. The structural and kinetic results indicate no inherent substrate discrimination between pCDK2/cyclin E and pCDK2/cyclin A with model substrates.