Psychophysiological and cardiohemodynamic effects of solar,geomagnetic, and meteorological factors in humans under the conditions of the arctic region

The influence of variations in solar, geophysical, and meteorological factors, as well as of the lunar cycle phases, on cardiohemodynamic, emotional and CNS parameters has been studied in 12 men (19–38 years old) permanently residing in the Arctic region (the town of Apatity, 67°57′ N, 33°39′ E). The period of observation was characterized by M1 and M2 class solar flares and G1-G3 class geomagnetic storms. The study has demonstrated the adaptive modulation effects of environmental factors on autonomic regulation systems and the perturbing influences of geomagnetic storm and solar chromospheric flares on human functional state. Multiple regression analysis was used to identify the dominant environment factors by the degree of their influence on functional parameters and to assess their combined effect. The coefficient of determination was no more than 0.5 on average; however, in some subjects, it reached 0.7–0.8 for certain parameters. All subjects were shown to respond to the permanent fluctuations of climatic-geographical and cosmophysical factors under the extreme conditions of high latitudes; however, response pattern and intensity depended on individual sensitivity to their isolated and combined effects.     

Changes in the mitotic cycle of Chinese hamster cells and the repair of radiation damage in cells following the action of ionizing radiation

Using DNA flow cytofluorimetry technique, the effect of ionizing and gamma irradiation on cell cycle in Chinese hamster cells of clone CHO K1 773 and of its derivative EBR-30 resistant to ethidium bromide was examined. Irradiation in doses of 1 and 5.5 Gr leads to a reduced rate of cell passing from G1 into S phase, to a prolonged S phase and to a larger postsynthetic block in EBR-30 cells than in 773 cells. Our data correlate with some delay in repair of gamma-induced (200 Gr) DNA single-strand breaks in the EBR-30 clone. Clones under investigation are not distinguished in their survival. Our results may arise from deficiency in some regulatory process usually involved in cell response to radiation-induced lesions.     

Surface polarization in loach eggs and two-cell embryos: correlations between surface relief, endocytosis and cortex contractility

The aim of this study was to examine the reorganization of the microfilamentous cortical layer (MC) accompanying ooplasmic segregation in loach eggs. Using scanning (SEM) and transmission electron microscopy (TEM), we found that the MC is thicker in folded areas. Prior to fertilization, surface microvilli are distributed more or less uniformly throughout the egg. A similar, more or less uniform, distribution of endocytotic events was observed in the eggs 5-15 min after insemination using fluorescence microscopy of Lucifer yellow CH uptake. During ooplasmic segregation, the surface is progressively polarized so that before the first cleavage onset (50-60 min after insemination) only the blastodisc surface is folded and undergoes endocytosis, whereas the vegetal surface is smooth and does not show internalization. In two-cell embryos, the blastomeric surface is also regionalized according to its relief and endocytosis. When surface tension was lowered by sucking most yolk granules out of the egg, we observed contractile responses only in the animal folded surface. These data suggest that a polar distribution of contractile structures is established in the loach egg undergoing ooplasmic segregation.     

Proteins and Saponins in the Lipid Preparation Obtained by Extraction of Soybean Flour

A complex lipid preparation was obtained by extracting soybean flour with organic solvents. This preparation was shown to include not only phospholipids (major components), but also 30% saponins. These compounds were identified by TLC, HPLC, and ¹H-NMR spectroscopy. Minor components of the lipid extract were represented by polypeptides bound to phospholipids by electrostatic or hydrophobic forces.     

Use of the reaction of macrophage disappearance from peritoneal exudate for characterizing cellular immunity in Salmonella immunization

The test of macrophage disappearance from peritoneal exudate quite effectively shows the state of cell-mediated immunity in guinea pigs immunized with both live and killed S. typhimurium culture. The macrophages of the animals immunized with killed S. typhimurium culture react to the protein extract of these bacteria more actively than the macrophages of the animals immunized with killed S. sonnei cultures, which indicates the specificity of this test.     

Secreted protein Noggin4 participates in the formation of forebrain structures in <Emphasis Type="Italic">Xenopus laevis</Emphasis> by inhibiting the Wnt/beta-catenin signaling pathway

Noggin proteins are important regulators of the early development of the vertebrate neural system. Previously, it has been traditionally thought that vertebrates have only one noggin gene (Noggin1), whose main function is the inhibition of BMP signaling pathway during the formation of dorsoventral polarity in embryos. Then other proteins of this family were discovered, and the studies of Noggin2 protein showed that noggin proteins also participate in the modulation of Nodal/Activin and Wnt/beta-catenin signaling pathways in the early development of amphibian head structures. The purpose of this study is to investigate the properties of another noggin protein, Noggin4. We proved that Noggin4 plays an important role in the formation of head structure in clawed frog, since it inhibits the activity of Wnt/beta-catenin signaling pathway. At the same time, unlike Noggin1 and Noggin2, Noggin4 does not inhibit the activity of TGF-beta signaling pathways (BMP and Nodal/Activin).     

The monolayer–spheres–monolayer cycle: Ultrastructural changes in stem cells

Stem cell sphere formation is applied as a preconditioning treatment prior to transplantation. Here, stem cells (SC) isolated from human subepicardial adipose tissue were analyzed at different stages of the monolayer–spheres–monolayer cycle by transmission electron microscopy. Spheres obtained on a non-adherent surface or through hanging drops gave similar results. At the first two or three passages (stage 1), isolated SC displayed an embryonal cell-like ultrastructure. With increased passage number (stage 2), SC became larger and more electron-dense with a multilobed nucleus, well-developed rough endoplasmic reticulum (RER), well-developed Golgi apparatus, and numerous vacuoles. At 2 h after sphere induction (stage 3), SC gathered into clusters and formed desmosome-like intercellular contacts. Their nuclei possessed a large loose fibrillo-granular nucleolus, the cytoplasm was tightly packed with disintegrated cisternae of RER, and Golgi apparatus was not identified. Twenty-four hours afterward (stage 4), SC in well-formed spheres exhibited a large dense nucleolus and poorly developed Golgi apparatus and RER. One day after sphere dissociation (stage 5), SC looked like embryonal cells and were morphologically similar to the cells of the first stage except for the presence of a large nucleolus and several Golgi complexes. At 48 h after sphere dissociation (stage 6), SC became electron-dense and resembled SC of the second stage, bearing irregular nuclei and cytoplasm that was rich in RER. We interpret these results as SC senescence with increasing passage number after isolation from the tissue or 1 day after sphere dissociation and rejuvenation of the SC just after sphere dissociation. Further research is needed to determine the genetic, biochemical, and physiological parameters of the SC corresponding to morphologically defined distinct stages in order to provide high quality cellular material for cell therapy.     

Effect of neuropharmacologic preparations and colchicine on morphogenetic processes in embryonal amphibian cells]

The effect of antagonists of biogenous amines (antitransmitters--AT) and colchicine on rapid morphogenetic processes in the explants of embryonic ectoderm with underlying mesoderm cut from the lateral region of Rana temporaria embryos at the late neurula-early taibud stages was studied. The normal morphogenesis of the explants consists of two successive phases: phase of contact polarization and phase of cell movement into the fragment. The high concentrations of AT inhibited completely the morphogenesis of explants but somewhat lower concentrations inhibited the second phase of morphogenesis and not only did not prevent the cell polarization but even assisted its propagation over all the fragment. The inhibiting effect of AT was relieved by 5-hydroxytryptamine which per se stimulated the morphogenesis of explants. Thus, AT exert a specific inhibition of the motility of embryonic cells but do not prevent the contact interactions responsible for cell polarization within every layer.