Resources of regeneration in planarians

We studied the intensity of blastema growth in operated planarians at an early stage of regeneration as a function of the following factors: area of regenerate and its function and number of regeneration foci (volume of regeneration). There was no direct dependence between the intensity of regeneration and the size of regenerating fragment, as well as the volume of regeneration. Some specific features of the early stage of regeneration have been described, which suggest its determinate character. The behavior of neoblasts during formation of blastemas with different localization is discussed.     

The role of lichens in high-mountain phytocenoses of Siberia

The authors have studied and analyzed the role of lichens in epilithic-lichen, stony, Alectoria, Dryas, fruticose-lichen, fescue, Cobresia, and yernik tundras, integral components of high-mountain vegetation.     

Heat shock-induced changes in the respiration of the yeast Saccharomyces cerevisiae

The incubation of Saccharomyces cerevisiae at elevated temperature (45 degrees C) stimulated the respiration of yeast cells and decreased their survival rate. The respiration-deficient mutant of this yeast was found to be more tolerant to the elevated temperature than the wild-type strain. At the same time, the cultivation of the wild-type strain in an ethanol-containing medium enhanced the respiration, catalase activity, and thermotolerance of yeast cells, as compared with their growth in a glucose-containing medium. It is suggested that the enhanced respiration of yeast cells at 45 degrees C leads to an intense accumulation of reactive oxygen species, which may be one of the reasons for the heat shock-induced cell death.     

Variable tandem repeat VcA of Vibrio cholerae

Computer analysis revealed seven potential variable-number tandem-repeat (VNTR) loci in the Vibrio cholerae genome. Specific primers were designed to amplify locus VcA located on chromosome 2 and containing a TGCTGT repeat. The locus was found in all tested strains from a V. cholerae strain collection, the repeat number varying 3 to 23. In total, 14 VcA alleles were observed. The VcA locus was proposed as a marker for the molecular typing of V. cholerae strains.     

A new program complex EFOLD for molecular modeling: the use of a flexible weighting coefficient scheme and the standard valence geometry in modeling the enzyme active sites

An algorithm for the representation of biopolymer structures in an internal coordinate system (so-called structure regularization) by minimizing the target function with a flexible weighting coefficient scheme using three components that determine the reliability of deviations of each atom was proposed. For the structure regularization, an algorithm for taking into account the temperature factor was suggested for the first time. It was shown by the example of the aspartyl protease rhizopuspepsin that the representation in the internal coordinate system may result in an accurate reproduction of the structural details of separate molecule fragments, such as the active site region of the enzyme. This algorithm was realized as one of the modules of our EFOLD program complex. The English version of the paper.     

Specific features of eye regeneration in multiocular planarians <Emphasis Type="Italic">Polycelis tenuis</Emphasis>

Regeneration and negative phototaxis were studied in planarians Polycelis tenuis, in which the anterior body end is fringed with many eyes. Comparative data for the same indices are given for binocular planarians Girardia tigrina. Multiple eyes regenerated gradually with a decrease in the rate of regeneration and independently from the rate of restoration of the anterior body end, where they are located. Negative phototaxis was restored independently from the total amount of regenerated eyes. It was unstable in both planarian species.     

Structure of spawning school of chum salmon Oncorhynchus keta from Olutorsky Bay of the Bering Sea (Northeastern Kamchatka)

Results of studies of spawning chum salmon Oncorhynchus keta (Walbaum) in Olutorsky Bay and the Apuka River—the largest river in northeast Kamchatka—inflowing Olutorsky Bay of the Bering Sea are presented. It was established that the first individuals of the chum salmon enter the river together with early sockeye salmon and chinook salmon in the first ten-day period of June, and mass-spawning run takes place in July–August. Analysis of biological characteristics of chum salmon caught in the Apuka River and Olutorsky Bay of the Bering Sea enabled us to reveal the inhomogeneity of its spawning school represented by two seasonal forms.     

Association of the polymorphic markers G(−455)A in the FGB gene and C(−1654)T in the PROC gene with hereditary predisposition to unfavourable outcome in patients with history of acute coronary syndrome

Associations of polymorphisms of genes FGB G(?455)A and PROC C(?1654)T with the frequency of poor outcomes in patients with the history of acute coronary syndrome (ACS) were studied in the Russian population. A total of 1145 patients admitted to cardiological hospitals of Moscow, St. Petersburg, Kazan, Chelyabinsk, Perm, Stavropol, and Rostov-on-Don with ischemic heart disease exacerbation were examined. The mean follow-up time was 1.14 ± 0.33 years, and the maximum follow-up time was 3.2 years. The risk of poor outcome did not depend on the carriership of genotypes of the polymorphic G(?455)A marker in the FGB gene. However, the PROC C(?1654)T polymorphism patients with ACS history and allele T of the PROC gene had a poor outcome more often than patients homozygous for allele C. The survival time to the endpoint for carriers of the TT and CT genotypes of the PROC gene was 2.19 ± 0.18 years vs. 2.46 ± 0.16 years for carriers of the CC genotype. On the base of these results it is suggested that hemostasis-related genes play an important role in early failures in patients with ACS history.     

Skewed X-chromosome inactivation in human miscarriages

The sex ratio in the first trimester of pregnancy shifts toward males due to increased elimination of female embryos. One reason for this phenomenon may be disruption of X chromosome inactivation. In this paper, we have analyzed the nature of the X chromosome inactivation in extraembryonic tissues of induced and spontaneous abortuses with 46,XX karyotype. Both equiprobable and asymmetric inactivation have been found in chorionic cytotrophoblast from spontaneous and induced abortuses. In the extraembryonic mesoderm of the control group of embryos, only equiprobable inactivation has been found, whereas this parameter was shifted in 15% of spontaneous abortions. The highest incidence of the selective inactivation of one of the parent homologues was found in the group with a lack of development of embryos and embryos from women with recurrent miscarriages. One of the reasons for the observed results can be compartmentalization of cells in the blastocyst leading to the nonrandom redistribution of cells and the predominance in the inner mass of cells with an active X chromosome with aberrations incompatible with normal embryonic development.