The Physical Aspects of the Primary Interaction of Therapeutic Ultrasound with Biological Tissue

Biophysics - The biophysical aspects of the effects of ultrasound on biological tissues are considered. A mathematical model that describes the effects of the primary interaction of mechanical...     

Polyploidization and endomitosis in giant cells of rabbit trophoblast

Morphological and cytophotometric investigations have been performed on giant cells of the rabbit trophoblast to reveal a mechanism of nuclei polyploidization and define the level of polyploidy. The character of endomitotic chromosomes is found to differ and depend largely on the degree of nuclei polyploidy. Small chromosomes were found in nuclei with low levels of polyploidy. For highly polyploid nuclei, two stages are distinguished. In the first case condensed chromosomes join into bundles resembling Riesenchromosomen in plants, whereas in the second, decondensed chromosomal threads separate and disperse in the karyoplasm. The splitting does not involve nuclei-forming chromosomes in the region of the nucleolar organiser. The degree of polyploidy was determined on the 15th day of development. It was found that giant cell nuclei contain DNA in amounts corresponding to 32-512 chromosomal sets. Most of the nuclei have levels of 128c and 256c. Highly-polyploid nuclei disintegrate into small nuclei with the degree of polyploidy varying from 1c to 32c. Di- tri- and tetraploid nuclei predominate.     

Notch Pathway Activation Contributes to Inhibition of C2C12 Myoblast Differentiation by Ethanol

The loss of muscle mass in alcoholic myopathy may reflect alcohol inhibition of myogenic cell differentiation into myotubes. Here, using a high content imaging system we show that ethanol inhibits C2C12 myoblast differentiation by reducing myogenic fusion, creating smaller and less complex myotubes compared with controls. Ethanol administration during C2C12 differentiation reduced MyoD and myogenin expression, and microarray analysis identified ethanol activation of the Notch signaling pathway target genes Hes1 and Hey1. A reporter plasmid regulated by the Hes1 proximal promoter was activated by alcohol treatment in C2C12 cells. Treatment of differentiating C2C12 cells with a gamma secretase inhibitor (GSI) abrogated induction of Hes1. On a morphological level GSI treatment completely rescued myogenic fusion defects and partially restored other myotube parameters in response to alcohol. We conclude that alcohol inhibits C2C12 myoblast differentiation and the inhibition of myogenic fusion is mediated by Notch pathway activation.     

Role of proteolytic enzymes in the interaction of phytopathogenic microorganisms with plants

Various forms of participation of proteolytic enzymes in pathogenesis and defense in plants are reviewed. Along with extracellular proteinases, phytopathogenic microorganisms produce specific effectors having proteolytic activity and capable of acting on proteins inside plant cells. In turn, for defense against pathogens, plants use both extracellular and intracellular proteinases.     

The role of microRNA in abiotic stress response in plants

Regulation of gene expression via microRNA is the key mechanism of response to biotic and abiotic stresses in plants. There are a lot of experimental data on the biological function of microRNAs in response to different stresses in various plant species. This review contains up-to-date information on molecular mechanisms of microRNA action in plants in response to abiotic stresses, including drought, salinity, mineral nutrient deficiency or imbalance.     

Taxonomic Status of the Okhotsk Lumpsucker Eumicrotremus ochotonensis (Cyclopteridae,Cottoidei) with Redescription of E. derjugini

Journal of Ichthyology - The species status is justified for the Okhotsk lumpsucker Eumicrotremus ochotonensis based on the morphological characters. The differences from the closely related...     

New molecular complexes of heterocyclic bis-adducts with bacterial lectins: synthesis and structure-activity relationship studies

A strongly antitumour effect has been discovered for lectins of Bacillus bacteria [Bacillus subtilis 668(1 + 2)IMV, Bacillus polymyxa 102(1 + 2) KGU] and for their molecular complexes with some heterocyclic bis-adducts of unsubstituted benzimidazole and 6-methyluracile for the first time. These were tested on the tumours: Lymphosarcoma Plissa, Sarcoma 45, Carcinosarcoma Yokera 256. A new convenient method for the preparation of the heterocyclic bisadducts of imidazole, benzimidazole, uraciles with 1,1,1-trifluoro-2-bromo-2-chloroethane is described. The reactions are catalysed by the 18-crown-6-complex.