The Cytoskeletal Protein Zyxin Modulates the Expression of the Target Genes of the Shh Signaling Cascade in the Cells of the Neural Plate of Embryos of the Spur-Toed Frog Xenopus laevis

Russian Journal of Bioorganic Chemistry - It has been shown earlier in a study of the role of the cytoskeletal protein zyxin in cell differentiation in the primordium of the central nervous system...     

Changes in indexes of cardiovascular system in different mental tasks

The influence of different types of mental activity on the cardiovascular system was analyzed by following indexes: the heart rate (HR), the variation magnitude (VM), the amplitude of systolic wave (SWA) and the pulse wave transit time (PWTT). A registration of these indexes was conducted when the subjects solved verbal-logical and spatial mental tasks. HR was significantly greater in the spatial tasks than in the verbal-logical tasks, while SWA had an inverse relationship. The time for solving of tasks of the both types did not differ significantly. Therefore, the observed changes in autonomic indexes were not related to a difficulty of the mental tasks, but depended on the specific cognitive processes involved in the mental tasks of different types. Thus, the observed change in HR and the decrease in SWA correlating with the blood pressure rise reflect an influence of the sympathetic nervous system on the heart work during mental tasks of the verbal-logic type. The obtained results suggest that the indexes of HR and a blood pressure may also serve as supporting criteria in a development of new technologies for a determination of different types of mental operations in addition to the rhythms of the brain electrical activity.     

The density of myocardial and pericardial rat mast cells in isoproterenol-induced heart failure

The multifunctional mast cells (MC), located in the myocardium, actively react to the pathology of a cardiovascular system. We investigated MC density in the pericardium and myocardium of rats in intact and experimental heart failure (HF) 24 h and 14, 28, and 60 days after two (at 24 h intervals) injections of Isoproterenol (IP) inducing necrosises in the myocardium. An expressiveness of HF was estimated with the help of ultrasonic scanning of the heart after 28 and 60 days after two IP injections. MC of different degrees of maturity were identified cytochemically on paraffin sections stained with Alcian blue-Safranine. The MC density in the myocardium of intact and experimental rats was relatively low, ranging from 4 to 6 cells/mm², thus the ratio of cells of a different degrees of maturity during HF development was reliably unchanging. In the fibrous layer of pericardium, the MC density was higher than in the myocardium and, for the intact rats, it amounted 48.6 ± 13.0 cells/mm². 24 h to 14 days after IP injections, the MC density in pericardium in contrast to intact sample increased on the average in 1.5 times (P < 0.05) at the expense of increase of density of more differentiated cells stained with Safranine, without density change of less differentiated cells stained with Alcian blue. After 28 days, the MC density in pericardium was 2 times higher than in the intact sample (P < 0.01) and, at the same time, the density of cells of a different maturity degree (P < 0.05) was considerably increased. For 60 days, the MC density and the balance of Alcian-and Safranine-positive cells did not differ reliably from the intact sample. The dynamic of behavior of the MC population of pericardium was corresponding to HF injury on functional parameters. The data obtained indicate the active reaction of MC pericardium on a dysfunction of the myocardium; it stimulates the maturation of resident MCs and the reinforcement of the population at the expense of the migration of cells from the outside, which allows us to propose an intensification of the MC secretory function.     

Molecular characterization of Streptococcus pneumoniae,particularly serotype19A/ST320, which emerged in Krasnoyarsk,Russia

Streptococcus pneumoniae , a common human pathogen, colonizes the nasopharynx and causes diseases including acute otitis media (AOM). Herein, pneumococcal serotype distributions in children before and after PCV7 vaccination and in patients with pneumococcal disease in Siberian Russia (Krasnoyarsk) are reported. Analyses included antimicrobial susceptibility testing, sequence typing (ST), pulsed field gel electrophoresis, virulence‐related surface protein gene (VSG) typing with novel primers and structural analysis by scanning electron microscopy. In healthy children (HC) prior to administration of PCV7, drug‐susceptible serotype23F/ST1500 was a major pneumococcal genotype. In the PCV7 trial, multidrug‐resistant serotype19A/ST320 emerged in vaccinees after PCV7, exhibiting a PCV7‐induced serotype replacement. Multidrug‐resistant serotype19A/ST320 was evident in patients with AOM. Community‐acquired pneumonia (CAP) isolates showed genetic similarities to the AOM (ST320) genotype, constituting a common non‐invasive AOM–CAP group. In contrast, meningitis isolates were more divergent. Overall, 25 ST types were identified; five (20%) of which were Krasnoyarsk‐native. Regarding VSGs, PI‐1 (rlrA /rrgB ), PI‐2 (pitA /B ), psrP and cbpA were present at 54.3%, 38.6%, 48.6%, and 95.7%, respectively, with two major VSG content types, PI‐1^?/PI‐2^?/psrP ⁺/cbpA ⁺ and PI‐1⁺/PI‐2⁺/psrP ^‐/cbpA ⁺, being found for HC and non‐invasive diseases, respectively. A major clone of serotype19A/ST320 (PI‐1⁺/PI‐2⁺) produced the longest pneumococcal wire (pilus) structures in colonies. ST1016 (PI‐1^?/PI‐2^?) in HC had HEp‐2 cell‐adherent pili. These results suggest that serotype19A/ST320 and related genotypes, with the VSG content type PI‐1⁺/PI‐2⁺/psrP ^?/cbpA ⁺, emerged in vaccinees after PCV7 in Siberia, accompanying diseases in non‐vaccinated children, and that some genotypes (serotypes19A/ST320 and 18/ST1016) produced novel pneumococcal structures, predicting their roles in colony formation and adherence.

     

Two new genera of cuckoo wasps (Chrysididae: Amiseginae) from Rovno and Baltic ambers

Cuckoo wasps of the subfamily Amiseginae, Eosega heterotarsata gen. et sp. nov. and Foveorisus kilimniki gen. et sp. nov., from the Late Eocene Baltic (Russia) and Rovno ambers (Ukraine), respectively, are described. Primitive Eosega is close to the extinct genus Palaeobethylus Brues in Kieffer, 1914 and represents the so-called American series of genera of Amiseginae. Foveorisus is found to be morphologically close to a number of extant oriental genera. All known fossil Amiseginae are listed. Stick insects of the family Archipseudophasmatidae, possible hosts of the Eocene amisegines, are recorded in the Rovno amber for the first time.     

Interaction of secreted factor Agr2 with its potential receptors from the family of three-finger proteins

Interactions of the secreted protein XAgr2 of the Agr (anterior gradient proteins) family with six submembrane proteins, Tfp1–6, from the family of three-finger proteins Ly6 were studied in Xenopus laevis embryos. Earlier, other authors have shown that the newt homologue of XAgr2 is able to bind the Prod1 three-finger protein, which participates in the establishment of the proximal-to-distal pattern of cell differentiation in the regenerating blastema of a newt’s limb bud. Here, we identified six homologues of Prod1 in Xenopus laevis genome named Tfp1–6. By co-immunoprecipitation, we demonstrated that among these homologues, Tfp4 is the most probable receptor of XAgr2. Further study of the revealed interactions between XAgr2 and Tfp4 is of significant interest because XAgr2 is involved in the signaling pathways that regulate neural system development and the body appendages regeneration.     

Age differences of event-related potentials in the perception of successive and spatial components of auditory information

The perception of spatial and successive contexts of auditory information develops during child ontogeny. We compared event-related potentials (ERPs) recorded in 5- to 6-year-old children (N = 15) and adults (N = 15) in response to a digital series with omitted digits to explore age differences in the perception of successive auditory information. In addition, ERPs in response to the sound of a falling drop presented binaurally were obtained to examine the spatial content of auditory information. The ERPs obtained from the omitted digits significantly differed in the amplitude and latency of the N200 and P300 components between adults and children, which supports the hypothesis that the perception of a successive auditory structure is less automatic in children compared to adults. Although no significant differences were found in adults, the sound of a falling drop presented to the left ears of children elicited ERPs with earlier latencies and higher amplitudes of the P300 and N400 components in the right temporal area. Stimulation of the right ear caused an increasing amplitude of the N100 component in children. Thus, the observed differences in the auditory ERPs of children and adults reflect developmental changes in the perception of spatial and successive auditory information.     

Preparation and analysis of biological activity of the secreted proteins of the Noggin family

Methods for preparation of recombinant physiologically active proteins of the Noggin family (Noggin1 and Noggin2) of the clawed frog Xenopus laevis that are capable of interaction with BMP factors of the TGF-beta superfamily have been developed. Structures were designed for the expression of Noggin1 and Noggin2 proteins allowing us to produce them from the directly microinjected synthetic mRNA in the cells of developing embryos of the clawed frog, as well as in the prokaryotic expression system. Target proteins contained three Myc-epitopes at the N-terminal. Introduction of these’ tags’ allowed comparison of the expression level of the Noggin1 and Noggin2 proteins, isolation on the affinity immunosorbent, and demonstration of biological activity of the isolated Noggin-proteins through the analysis of their ability to bind the BMP4 factor of the TGF-beta superfamily with coimmunoprecipitation method.     

Structural analysis of carbohydrate chains of normal and myeloma immunoglobulins G using HPLC

A comparative analysis of carbohydrate chains from human normal IgG and myeloma IgG (subclass 4) was carried out using HPLC. It is shown that both IgGs contain the same carbohydrate chains (biantennary and bisected) but the relative amount of bisected and incomplete chains (with fewer terminal galactose residues) is higher in myeloma IgG4. Two earlier unknown minor oligosaccharides were isolated from normal IgG and structurally studied by means of the partial hydrolysis and the Smith degradation.