Recognition of classes of noise-like signals by dolphins Tursiops truncatus

The ability of the auditory system to perceive and to classify the noise-like signals imitating natural sea noises has been studied in dolphins Tursiops truncates. Results of the studies carried out in a sea bay at free movement of the animals have shown that dolphins are able to determine noise-like signals and to ascribe them to a certain class by using invariant characters, such rhythmical sequence of impulses, regardless of the frequency-time scale of the signal presentation.     

Leukocyte preservation at near-zero temperatures

Intense metabolism and fast exhaustion of the energy potential of nucleate blood cells at positive temperatures substantially reduce the duration of their storage in a viable state. However, this transfusion environment is extremely necessary for clinical purposes. The popular method of cell preservation at an ultralow temperature (?196°C) is limited in application because of the use of liquid nitrogen, special equipment, and trained engineering staff. The goal of this study was to develop an efficient and simple method of leukocyte preservation at near-zero temperatures (+2°–0°C) using a standard household refrigerator and a novel cryopreservation solution.     

Frequency,composition and mobility of Escherichia coli-derived transposable elements in holdings of plasmid repositories

By providing the scientific community with uniform and standardized resources of consistent quality, plasmid repositories play an important role in enabling scientific reproducibility. Plasmids containing insertion sequence elements (IS elements) represent a challenge from this perspective, as they can change the plasmid structure and function. In this study, we conducted a systematic analysis of a subset of plasmid stocks distributed by plasmid repositories (The Arabidopsis Biological Resource Center and Addgene) which carry unintended integrations of bacterial mobile genetic elements. The integration of insertion sequences was most often found in, but not limited to, pBR322-derived vectors, and did not affect the function of the specific plasmids. In certain cases, the entire stock was affected, but the majority of the stocks tested contained a mixture of the wild-type and the mutated plasmids, suggesting that the acquisition of IS elements likely occurred after the plasmids were acquired by the repositories. However, comparison of the sequencing results of the original samples revealed that some plasmids already carried insertion mutations at the time of donation. While an extensive BLAST analysis of 47 877 plasmids sequenced from the Addgene repository uncovered IS elements in only 1.12%, suggesting that IS contamination is not widespread, further tests showed that plasmid integration of IS elements can propagate in conventional Escherichia coli hosts over a few tens of generations. Use of IS-free E. coli hosts prevented the emergence of IS insertions as well as that of small indels, suggesting that the use of IS-free hosts by donors and repositories could help limit unexpected and unwanted IS integrations into plasmids.     

Biological activities of phenolic compounds and ethanolic extract of <Emphasis Type="Italic">Halacsya sendtneri</Emphasis> (Boiss) Dőrfler

The objective of this study was to evaluate the efficacy of the ethanolic extract of endemic plant Halacsya sendtneri in inhibiting the growing of the test fungi and bacteria as well as to determine its genotoxic potential and toxicity using the Allium anaphase-telophase assay. Minimum inhibitory concentrations (MIC) were determined for 15 indicator strains of pathogens, representing both bacteria and fungi. The highest susceptibility to the ethanolic extract of H.sendtneri was exhibited by Pseudomonas glycinea (FSB4), (MIC=0.09 mg/ml) among the bacteria, and by Phialophora fastigiata (FSB81), (MIC=1.95 mg/ml) among the fungi. The composition of H. sendtneri extracts was also determined using HPLC analysis. Rosmarinic acid was found to be the dominant phenolic compound. The Allium anaphase-telophase genotoxicity assay revealed that the ethanolic extract of H. sendtneri at concentrations of 31.5 mg/l and below does not produce toxic or genotoxic effects. This is the first report of chemical constituents, genotoxic and antimicrobial activities of the endemic species, H. sendtneri.     

The synthesis and mass spectrometry of oligonucleotides bearing thiophosphoryl modifications of the predetermined localization

The technique of parallel automated synthesis of oligodeoxynucleotides bearing various local thiophosphoryl internucleotide bonds was optimized using assembling in the standby mode and creation of special program blocks. The selected conditions of Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI TOF MS) provided an increase in the method sensitivity (up to 1–10 fmol of oligonucleotide in sample) and registration of reliable spectra of oligodeoxynucleotide thiophosphoryl analogues. This enables to reliably prove the presence of the specified number of thiophosphoryl bonds within synthetic sequences. A series of oligodeoxynucleotides, thioanalogues of d(GGTTGGTGTGGTTGG), a known G-quadruplex antithrombin aptamer, were obtained.     

Regulation of lysine biosynthesis in the leucine-dependent mutant of Micrococcus glutamicus]

The role of leucine in metabolism of Micrococcus glutamicus was examined in relation to the lysis synthesis by the homoserine- and leucine-dependent strains of M. glutamicus 106 and the homoserine-dependent strain of M. glutamicus 95. In addition to the growth function, leucine produced a controlling effect on the yield of the end product. In the presence of leucine the inhibitory effect of isoleucine on the lysine yield was reduced or reversed. The end effect depended on the leucine: isoleucine ratio. The mechanism of interaction of amino acid metabolites with respect to the lysine biosynthesis in both strains is discussed.     

DAPK and cytoskeleton-associated functions

Death-associated protein kinase (DAPK) undergoes activation in response to various death stimuli, and they have been associated with an increase in DAPK catalytic activity. One of the most prominent features of DAPK-induced cell death is the effect on the cytoskeleton, including loss of matrix attachment, and membrane blebbing. One known cytoskeletal-associated substrate of DAPK is the myosin-II light chain, phosphorylated by DAPK on Ser¹⁹, thus stabilizing actin stress fibres. Moreover, paxillin, a component of focal adhesions, was found to be localized in close proximity to the tips of the DAPK-positive filaments, indicating that stress fibres containing DAPK extend to focal contacts. Forced expression of DAPK in multiple cell types results in morphological changes such as cell rounding, membrane blebbing, shrinking and detachment. During directed migration, DAPK functions as a potent inhibitor of cell polarization, as evidenced by its perturbation of the formation of static protrusion at the leading edge. Furthermore, DAPK inhibits random migration by suppressing directional persistence. One of the studies considered DAPK as an anoikis inducer. Others showed that DAP-kinase inhibits the activities of cell surface integrins by converting them into an inactive conformation. Biochemical experiments have established the DAPK binding to Syntaxin1 and its subsequent phosphorylation at Ser¹⁸⁸ in a Ca²⁺ dependent manner. This phosphorylation event has been shown to decrease the binding of Syntaxin to MUNC18-1, a protein critically involved in synaptic vesicle docking. Here, we have investigated the structural interactions that modulate DAPK phosphorylation with Syntaxin and its functional role in binding to the MUNC18-1 to regulate vesicle docking. This review will summarize our current knowledge of the role of DAPK on cytoskeleton reorganization and report the mechanisms that regulate these changes.     

Comparative Analysis of SOX3 Protein Orthologs: Expansion of Homopolymeric Amino Acid Tracts During Vertebrate Evolution

To understand more fully the structure and evolution of the SOX3 protein, we comparatively analyzed its orthologs in vertebrates. Since complex disorders are associated with human SOX3 polyalanine expansions, our investigation focused on both compositional and evolutionary analysis of various homopolymeric amino acid tracts observed in SOX3 orthologs. Our analysis revealed that the observed homopolymeric alanine, glycine, and proline tracts are mammal-specific, except for one polyglycine tract present in birds. Since it is likely that the SOX3 protein acquired additional roles in brain development in Eutheria, we might speculate that development of novel brain functions during the course of evolution was affected, at least in part, by such structural–functional changes in the SOX3 protein.     

Regulation of apoptotic signal by strontium in immunocytes

Exposure to heavy metals can initiate the development of negative effects in different organs and systems, including the immune system, and can be manifested as dysfunction of receptor systems and intracellular signaling. The participation of stable strontium (Sr²⁺) in the regulation of apoptotic signals in immunocompetent cells was analyzed. Various mechanisms of strontium-induced modulation of the apoptotic lymphocyte reaction were described, and the formation of intracellular signal transduction involving Sr²⁺ was defined. The flow cytometry method was used to study changes in membrane and intracellular markers of apoptosis in children who consumed drinking water with the elevated levels of strontium. It was shown that the content of strontium in blood in the range of 0.0129–0.173 mg/dm³ affected different ways of apoptosis regulation (CD95-, p53-, and TNF-induced apoptosis) and their integration sites, thereby reducing the transmission of apoptotic signal in immunocompetent cells, and formed an alternative pathway of the cell elimination based on the mechanism of necrosis.     

Preservation of leukocytes at moderately low temperatures

It was shown that the use of low-toxic cryopreservative based on glycerol (endocellular protectant), hydroxyethyl starch (exocellular protectant), and 3-hydroxy-6-methyl-2-ethylpyridine succinate (restoring component) makes it possible to preserve nucleated blood cells in a viable state at ?40°C.