Left ventricular heart aneurism--a new source of resident cardiac stem cells

In the past few years it has been established that the heart contains a reservoir of stem and progenitor cells that have the ability to differentiate in vitro and in vivo toward vascular and cardiac lineages and that show cardiac regeneration potential in vivo following injection into the infracted myocardium. The aim of the present study was to characterize cardiac stem cells in the tissue of chronic left ventricular aneurism. It was shown that human c-kit positive cells were scattered in fibrous, muscle and adipose parts of aneurism tissue. C-kit positive cells localized mainly in fibrous tissue nearby large vessels, however, c-kit positive cells did not express endothelial, smooth muscle or cardiomyocyte cell markers. Co-localization experiments demonstrated that all c-kit positive cells were of non-hematopoietic origin, since they did not express markers such as CD34 and CD45. Majority of c-kit positive cells expressed MDR1, but showed no proliferation activity (Ki67). It thus appears that aneurism tissue could be an alternative source of autologous cardiac stem cells. However, their regeneration capacity should be further explored.     

Induction by ethanol of 'phenomenon of switching estrogen effect' and its correction]

Drinking of 5% ethanol in combination with estradiol induced genotoxic (G) changes in the rat uterine tissue. The changes could be prevented by N-acetylcysteine or melatonin. The data obtained suggest that ascorbic acid and alpha-tocopherol may be recommended in combination with N-acetylcysteine for repair of estrogen effect switching phenomenon.     

Computational method for predicting protein functional sites with the use of specificity determinants

The currently available body of decoded amino acid sequences of various proteins exceeds manifold the experimental capabilities of their functional annotation. Therefore, in silico annotation using bioinformatics methods becomes increasingly important. Such annotation is actually a prediction; however, this can be an important starting point for further laboratory research. This work describes a new method for predicting functionally important protein sites, SDPsite, on the basis of identification of specificity determinants. The algorithm proposed utilizes a protein family aglinment and a phylogenetic tree to predict the conserved positions and specificity determinants, map them onto the protein structure, and search for clusters of the predicted positions. Comparison of the resulting predictions with experimental data and published predictions of functional sites by other methods demonstrates that the results of SDPsite agree well with experimental data and exceed the results obtained with the majority of previous methods. SDPsite is publicly available at http://bioinf.fbb.msu.ru/SDPsite.     

Cytoarchitectonic and neurochemical properties of spinal cord in teleost fishes

Traditional neuromorphological and NADPH-diaphorase methods were used to study the topography, morphology and neurochemical organization properties of spinal cord in teleosts fishes. The heterogeneous population of NO-producing motoneurons was revealed in the motor column of spinal cords from studied species. Dendrites of primary motoneurons formed rich plexus at the spinal segment periphery. This morphological pattern is determined by translational motion of the fishes in the water (trunk-tail movement), and has no connection with the origin of upper and lower extremities. The NO-producing capacity of spinal motoneurons shows their connection with premotor NO-ergic brain system, including over situated motor centers of reticular formation and descending projections of giant steam neurons (Mauthner and Muller cells). The NO-producing Rohon-Berd neurons were found in the dorso-medial part of spinal cord from studied fishes. These cells with the ascending propriospinal targets form spinal nociceptive system. Thus, the sense Rohon-Berd cells and most motor neurons of studied bony fishes are nitric oxide synthesizing ones. Spinal cord NO-synthesizing territories are situated in concordance with dorso-ventral histochemical gradient. Spinal cord interneurons of these fishes produce nitric oxide selectively. The quantity of NO-synthesizing reticular cells is determined by two main factors: the connection with the specialized neurochemical complexes, where NO is a specific neuromodulator, and individual properties of spinal cord structure directed by conditions of morphoadaptation.     

Cajal bodies and the nucleolus are required for a plant virus systemic infection

The nucleolus and Cajal bodies (CBs) are prominent interacting subnuclear domains involved in a number of crucial aspects of cell function. Certain viruses interact with these compartments but the functions of such interactions are largely uncharacterized. Here, we show that the ability of the groundnut rosette virus open reading frame (ORF) 3 protein to move viral RNA long distances through the phloem strictly depends on its interaction with CBs and the nucleolus. The ORF3 protein targets and reorganizes CBs into multiple CB-like structures and then enters the nucleolus by causing fusion of these structures with the nucleolus. The nucleolar localization of the ORF3 protein is essential for subsequent formation of viral ribonucleoprotein (RNP) particles capable of virus long-distance movement and systemic infection. We provide a model whereby the ORF3 protein utilizes trafficking pathways involving CBs to enter the nucleolus and, along with fibrillarin, exit the nucleus to form viral 'transport-competent' RNP particles in the cytoplasm.     

The correlation between the synthesis of beta-carotene and zygote formation by Blakeslea trispora heterothallic strains

It was demonstrated for the first time that the level of carotenogenesis by the heterothallic Blakeslea trispora strains intensively forming zygospores decreased under conditions of a surface cocultivation during their sexual interaction as compared with the strains grown separately. On the contrary, carotenogenesis was stimulated during a sexual interaction of the strains incapable of forming zygotes. In a submerged culture, the zygote-forming pairs of strains synthesized a considerably larger amount of trisporic acids but a smaller amount of carotenoids than the strains not forming zygospores. The discovered inverse dependence between zygote formation and carotenogenesis allowed us to suggest the inability to form zygotes as a criterion for selecting carotenogenic strain pairs.     

Delayed effect of prenatal exposure to hypoxia on the susceptibility of rats to electric seizures

We studied the delayed effects of prenatal exposure to hypoxia on the susceptibility of rats to seizures. The later was estimated using graded electroshock. The experiments were performed in two groups of 1.5-year-old male Wistar rats. The experimental group consisted of the animals that were exposed to hypoxia on day 14 of prenatal development, and the control group consisted of the animals that developed under the normal conditions. In the rats subjected to prenatal hypoxia, seizure episodes induced by weak currents in the range of 10–40 mA and their average duration were more pronounced as compared to the control animals.