Involvement of Ca<Superscript>2+</Superscript> in the development of ischemic disorders of myocardial contractile function

The review addresses the role of Ca²⁺ ions in the development of ischemic disorders of myocardial contractility associated with changes in Ca²⁺ homeostasis in cardiomyocytes and mitochondrial Ca²⁺ overload. A special attention is paid to the analysis of intracellular signaling mechanisms activated during the development of ischemic and reperfusion injury of the myocardium.     

Obtaining of intrapopulational dissociants of some bacilli and the use of DIR-PCR for their identification

The paper is the first to suggest methods for rapid obtaining and genotypic identification of phenotypic (colonial-morphological) dissociants of bacterial cultures. For revelation of the potential dissociation ability and obtaining of dissociants, the use of bacterial cyst-like refractile cells (CRC) is recommended. These cells are characterized by enhanced variability; upon their first passage, an abrupt increase in the dissociation index is observed as a result of the emergence of cells that form morphologically different types of colonies. The approaches elaborated were tested with Bacillus cereus, B. subtilis, and B. licheniformis, for which colonial-morphological dissociants of various types were obtained after the first passage of CRC (both of those formed in the developmental cycle of bacteria and of those arising as a result of artificial increase of the concentration of anabiosis autoinducers in the cultivation medium). The genomic distinctions between dissociants of B. cereus and B. subtilis were estimated using polymerase chain reaction with a primer system designed based on the analysis of nucleotide sequences of complete prokaryotic genomes available in the GenBank database (DIR-PCR). The application of the suggested method allowed distinctions between the genomes of dissociants of Bacillus cereus and B. subtilis to be revealed, which is in agreement with the hypothesis that suggests reversible intragenomic rearrangements to be the basis of bacterial dissociation into subpopulations.     

Organization of the Brain Systems of Aim-Directed Behavior: New Data

Currently, the dominating approach to studying functional brain organization is based on the so-called activation studies, in the frameworks of which the functional specializations of different brain structures in the context of studied nature of activity are specified according to their energy states. The concept of organization of brain systems is formed largely thanks to such activation research. However, our studies devoted to the analysis of functional relations between different nodes of the brain systems show that they are much more complicated than they are presented in the activation studies. The structure of brain systems is not limited to those elements that are involved in its work by changing their local neuronal activity. This fact dramatically changes our views on how the brain systems are organized.     

Images of Alu-sequence in 7 DNA clones from the human genome

Information theory methods were used for computer search of Alu-like sequences in human DNA and RNA. Eight new regions related to the Alu repeat sequence was revealed in 85 clones from the EMBL-5 data bank. Some of these regions are purine-pyrimidine images of Alu repeats sequence, the rest are more complex images of Alu repeat sequence. A new definition for the likeness of different sequences--information image of sequence--was introduced. This information theory application greatly increases the power of DNA sequences computer analysis.     

The meadow tick Dermacentor reticulatus in natural foci of tick-borne encephalitis in Udmurtia

In southern Udmurtia, where occur both Dermacentor reticulatus and Ixodes persulcatus, in the years of high abundance of small mammals feeding periods of larvae and nymphs of these ticks coincide completely. The duration of simultaneous parasitism of preimago of the above ixodid species on animals is of epidemiological significance as far as within this period the infection of young stages of D. reticulatus with the virus of tick-borne encephalitis occurs. This is confirmed by the isolation of I strain of the virus from D. reticulatus collected at the state of engorged nymphs on hosts common with I. persulcatus and moulted in the laboratory.     

Tl+ Showed Negligible Interaction with Inner Membrane Sulfhydryl Groups of Rat Liver Mitochondria,but Formed Complexes with Matrix Proteins

The effects of Tl⁺ on protein sulfhydryl (SH) groups, swelling, and respiration of rat liver mitochondria (RLM) were studied in a medium containing TlNO₃ and sucrose, or TlNO₃ and KNO₃ as well as glutamate plus malate, or succinate plus rotenone. Detected with Ellman's reagent, an increase in the content of the SH groups was found in the inner membrane fraction, and a simultaneous decline was found in the content of the matrix‐soluble fraction for RLM, incubated and frozen in 25–75 mM TlNO₃. This increase was greater in the medium containing KNO₃ regardless of the presence of Ca²⁺. It was eliminated completely for RLM injected in the medium containing TlNO₃ and then washed and frozen in the medium containing KNO₃. Calcium‐loaded RLM showed increased swelling and decreased respiration. These results suggest that a ligand interaction of Tl⁺ with protein SH groups, regardless of the presence of calcium, may underlie the mechanism of thallium toxicity.