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

Migrations, Wintering and Summering Sites of Juvenile Imperial Eagles from the Volga Region, Russia

The paper reviews results of studying migration routes; wintering and summering sites of five juvenile Imperial Eagles (Aquila heliaca) from the Volga region tagged with GPS/GSM-trackers. Details of seasonal movements of five juvenile Imperial Eagles were made on the basis of 28 thousand points of location; received during the period from July 2017 to December 2018

Application of Laser Scanning Confocal Microscopy for the Visualization of M. tuberculosis in Lung Tissue Samples with Weak Ziehl–Neelsen Staining

One of the key requirements for the diagnosis of pulmonary tuberculosis is the identification of M. tuberculosis in tissue. In this paper, we present the advantages of specific fluorescent antibody labelling, combined with laser scanning confocal microscopy (LSCM), for the detection of M. tuberculosis in histological specimens of lung tissues. We demonstrate that the application of LSCM allows: (i) The automatic acquisition of images of the whole slice and, hence, the determination of regions for subsequent analysis; (ii) the acquisition of images of thick (20–40 μm) slices at high resolution; (iii) single bacteria identification; and (iv) 3D reconstruction, in order to obtain additional information about the distribution, size, and morphology of solitary M. tuberculosis; as well as their aggregates and colonies, in various regions of tuberculosis inflammation. LSCM allows for the discrimination of the non-specific fluorescence of bacteria-like particles and their aggregates presented in histological lung samples, from the specific fluorescence of labelled M. tuberculosis, using spectrum emission analysis. The applied method was effective in the identification of M. tuberculosis in lung histological samples with weak Ziehl–Neelsen staining. Altogether, combining immunofluorescent labelling with the application of LSCM visualization significantly increases the effectiveness of M. tuberculosis detection