Molecular-biologic analysis of avian influenza virus isolates which caused epizootics on the south of West Siberia and in Crimea

The objective of the study was to determine reasons of poultry deaths in Crimea Republic in December 2005 as well as isolation, identification, and comparative analysis of pathogens, which caused epizootics in Siberia and Crimea. During epizootic in poultry in North-East Crimea highly pathogenic avian influenza virus H5N1 was isolated. Phylogenetic analysis of RNA sequences revealed that they belong to one big cluster. Isolated strain was close to viruses, which caused epizootic in July-August 2005 in the south of West Siberia. Conclusion about the high importance of the south of West Siberia in spreading of highly pathogenic influenza viruses H5N1 in Eurasia was made.     

Glycotargeting to improve cellular delivery efficiency of nucleic acids

Nucleic acids bearing glycans of various structures have been under vigorous investigation in the past decade. The carbohydrate moieties of such complexes can serve as recognition sites for carbohydrate-binding proteins—lectins—and initiate receptor-mediated endocytosis. Therefore, carbohydrates can enhance cell targeting and internalization of nucleic acids that are associated with them and thus improve the bioavailability of nucleic acids as therapeutic agents. This review summarizes nucleic acid glycosylation in nature and approaches for the preparation of both non-covalently associated and covalently-linked carbohydrate-nucleic acid complexes.     

Protease from a strain of bacteria E. coli A2, specifically cleaving actin

A novel bacterial protease specifically hydrolyzing actin with the formation of a stable fragment with Mr of 36 kDa was obtained. This protease was shown to be synthesized at the stationary phase of bacterial culture growth. The actin hydrolysis by bacterial protease was inhibited by o-phenanthroline, EDTA and p-chloromercuribenzoate but not by N-ethyl-maleimide, phenylmethylsulfonylfluoride, Leu-peptin, pepstatin and other serine proteinase inhibitors. The protease was stable within the pH range of 4.5-8.5 and had an activity optimum at pH 7.0-8.0. The protease activity was maintained for 40 min at 45 degrees C and for 30 min at 50 degrees C; at 65 degrees C the enzyme was fully inactivated by 5 min heating. The protease preparations causing quantitative conversion of actin into a 36 kDa fragment did not hydrolyze casein, albumin, ovalbumin, lysozyme, DNAase I, RNAase, myosin, alpha-actinin, tropomyosin and troponin. It was assumed that the protease under consideration is a neutral metalloprotease specifically hydrolyzing actin.     

Fluorescence microscopy and 3D image reconstruction of cytokine initiated disruption of the Parkinson disease associated proteins α-synuclein, tau and ubiquitin in cultured glial cells

Human derived glioblastoma cells were cultured and treated with cytokines interleukin-6 (IL6), tumor necrosis factor alpha (TNF) and interferon-gamma (IFN) and imaged by fluorescence deconvolution microscopy to localize α-synuclein, tau and ubiquitin. Exposures were for short (2 h) and prolonged times (up to 96 h), with doses at both low (10 ng/ml), and high (100 ng/ml) concentrations. Further experiments used additive doses up to 200 ng/ml (2 × 100 ng), mimicking a super-infection state. Single, low doses of the cytokines initiated changes in levels of intracellular proteins, but these changes, be they increases or decreases, were not sustained, so we added higher doses of cytokine to the culture medium or fresh aliquots of cytokines over time. Finally, we treated cells with high, single doses of cytokine (200 ng/ml), to try to sustain perturbations of the proteins with cytokines. IFN caused a disruption and reduction of peripheral synuclein, TNF treatment resulted in increased levels of ubiquitin and IL6 disrupted and appeared to fragment tau. Of note, each of the proteins was found in a specific locale, tau being perinuclear, ubiquitin residing in the cytoplasm, and α-synuclein occupying the tips of cellular processes, exhibiting the characteristics of an adhesion protein/molecule [Word count = 198].     

Regeneration and DNA synthesis in cultures of rat heart ventricles after damage to the cellular layer

By means of the 3H-thymidine radioautography method replicative activity of myocytes and other cells in a dense layer of cellular culture of the traumatized ventricular myocardium has been studied in newborn (2-3-day-old) rats after lesion of the myocardium. Proliferation of the non-muscular cells is sharply suppressed after the cellular layer formation: their labelling index (LI) is 5.7 +/- 2.2% on the 8th day. Simultaneously, LI of unicellular myocytes is 25 +/- 6%, and that of binuclear ones, specific for the myocardium of mature animals is 6.4 +/- 2.9%. That demonstrates autonomy of DNA synthesis in myocytes from its suppression in the surrounding non-muscular cells. For 1-2 days after trauma intensive migration of fibroblasts into the wound is observed; they are often oriented perpendicularly to the edges of the cellular layer. There is an activation of DNA synthesis in the non-muscular cells in the wound area (in 20 h after the lesion LI is 73.4 +/- 1.7%) and in the layer edge directed to the wound LI is 23.9 +/- 0.0%, while in the depth of the zone situating close to the wound their LI is 7.8 +/- 2.4%. The replicative activity of mononuclear cardiomyocytes in the zone mentioned increases very weakly (LI 32 +/- 5%), and LI of binuclear ones is practically unchanged (6.1 +/- 2.3%). Karyo-kinetic activity is estimated by amount of binuclear cardiomyocytes and in the zone near the wound, in comparison to that in an intact layer, it does not change (35 +/- 3% and 34.4 +/- 2.5%).(ABSTRACT TRUNCATED AT 250 WORDS)