Partial restoration of the actin cytoskeleton in transformed Syrian hamster fibroblasts selected for low levels of ‘typical’ multidrug resistance

AbstractTwo independent colchicine (CLC)-resistant sublines of Rous sarcoma virus-transformed Syrian hamster flbroblasts were isolated. Each subline represented variants with 11- and 12.4-fold resistance, respectively, their 23- and 23.7-fold resistant descendants, as well as variants cultured in CLC-free medium for 10 months without loss of resistance. All variants demonstrated ‘typical’ multidrug resistance. The parental cells contained actin in dispersed form, as determined by rhodamine-phalloidin staining. In contrast, already in 11- and 12.4-fold resistant sublines up to 30% of cells demonstrated restored stress fibers. Cultivation in CLC-free medium leads to the accumulation of cells with a partially restored actin cytoskeleton. Putative mechanisms of up-regulation of stress fiber assembly in cells with P-glycoprotein-mediated multidrug resistance are discussed

The Discourse Personality of Politician Sergey Mikheyev with Regards to his Speech Behaviour

This paper presents the results of research into the linguistic personality of politician Sergey Mikheyev when viewed as a discourse personality. Special consideration has been given to the speech behaviour characteristic of a discourse personality. The paper presents the results of the cognitive-discursive and linguo-rhetorical description of a discourse personality.The relevance of this research is based on the growing interest for linguistic personality typology with regards to discourse (K. F. Sedov, V. I. Karasik, N. D. Golev, A. V. Bolotnov, et al.). A mixed type of political discourse that actualises both the personal and status factors of its formation was chosen as the object of analysis. The research focuses on semantic dominants and semantic constructs of the discourse behaviour of the Russian politician Sergey Mikheyev, as well as on the cognitive and linguo-rhetorical mechanisms of the interpretation of speech acts when viewed as elements of individual discourse behaviour. We define the linguo-rhetorical competence of the politician’s personality. The study is novel in that it identifies semantic dominants and semantic constructs found in Mikheyev’s discourse and uses an integrative approach to analysis (cognitive-discursive and linguo-rhetorical). It is proven that semantic dominants, constructs, and presuppositions manifest inventive mechanisms of individual discourse activity. We suggest defining the status of Mikheyev’s discourse personality as a mixed type of elitist linguistic personality that is pragmatically oriented. We prove that the discourse personality of Sergey Mikheyev is a prototype of a future successful politician’s linguistic personality. The paper presents the author’s original communicative competence system of S. Mikheyev’s discourse personality

Post-Soviet shifts in grazing and fire regimes changed the functional plant community composition on the Eurasian steppe

Globally, grasslands are shaped by grazing and fire, and grassland plants are adapted to these disturbances. However, temperate grasslands have been hotspots of land‐use change, and how such changes affect interrelations between herbivory, fire and vegetation are poorly understood. Such land‐use changes are widespread on the Eurasian steppe, where the dissolution of the Soviet Union in 1991 triggered the abandonment of cropland and pasture on globally relevant scales. Thus, to determine how relationships between plant functional composition, grazing and fire patterns changed after the Soviet Union dissolved, we studied a 358,000 km2 region in the dry steppe of Kazakhstan, combining a large field dataset on plant functional traits with multi‐scale satellite data. We found that increases in burned area corresponded to decreases in livestock grazing across large areas. Furthermore, fires occurred more often with high cover of grasses with high leaf dry matter content and thus higher flammability, whereas higher grazing pressure favoured grazing‐tolerant woody forbs and ruderal plants with high specific leaf area. The current situation of low grazing pressure represents a historically exceptional, potentially non‐analogue state. We suggest that the dissolution of the Soviet Union caused the disturbance regime to shift from grazer to fire control. As grazing and fire each result in different plant functional compositions, we propose that this led to widespread increases in grasses and associated changes in steppe plant community structure. These changes have potentially occurred across an area of more than 2 million km2, representing much of the world's largest temperate grassland area, with globally relevant, yet poorly understood implications for biodiversity and ecosystem functions such as carbon cycling. Additionally, future steppe management must also consider positive implications of abandonment (‘rewilding’) because reverting the regime shift in disturbance and associated changes in vegetation would require grazing animals to be reintroduced across vast areas.Volkswagen Foundation http://dx.doi.org/10.13039/501100001663Peer Reviewe

Analysis of T-Cell Receptor-γ Gene Rearrangements Using Oligonucleotide Microchip: A Novel Approach for the Determination of T-Cell Clonality

T-cell clonality estimation is important for the differential diagnosis between malignant and nonmalignant T-cell proliferation. Routinely used methods include polymerase chain reaction (PCR) analysis of T-cell receptor-γ (TCR-γ) gene rearrangements followed by Genescan analysis, polyacrylamide gel electrophoresis, or heteroduplex analysis to visualize amplification products. Here, we present a new method for the analysis after PCR of TCR-γ rearrangements using hybridization on oligonucleotide microchip. A microchip was designed to contain specific probes for all functional variable (V) and joining (J) gene segments involved in rearrangements of the TCR-γ locus. Fluorescently labeled fragments of rearranged γ-chain from patients and donors were obtained in a multiplex nested PCR and hybridized with a microchip. The results were detected using a portable microchip analyzer. Samples from 49 patients with T-cell lymphomas or leukemias and 47 donors were analyzed for T-cell clonality by microchip and single-strand conformation polymorphism analysis, which served as a standard reference method. Comparison of two techniques showed full concordance of the results. The microchip-based approach also allowed the identification of V and J gene segments involved in the particular TCR-γ rearrangement. The sensitivity of the method is sufficient to determine 10% of clonal cells in the sample