The inhibition by the tumor necrosis factor of the death and DNA fragmentation of lymphoid cells in irradiated rats]

The influence of a tumor necrosis factor, administered 16 h before irradiation of rats, on the radiation response of thymus and bone marrow cells has been investigated. Three and 6 h after irradiation the following indices were analyzed: the number of apoptotic cells in the thymus; the accumulation of polydeoxyribonucleotides and the appearance of single-strand breaks in DNA of bone marrow and thymus cells; and the electrophoretic properties of thymocyte DNA. The injection of a tumor necrosis factor reduced the number of polydeoxyribonucleotides, inhibited internucleosome DNA fragmentation, and did not influence the formation of single-strand breaks in DNA.     

Synthesis and antianemic activity of nanosized biocomposite ferroarabinogalactan

An aggregation-stable highly resistant nanobiocomposite, a stimulator of hemopoiesis, has been synthesized and characterized by physicochemical methods. The biocomposite represents nanodisperse iron oxides encapsulated into a biocompatible biogenic matrix of arabinogalactan from Siberian larch (Larix sibirica). The effect of the novel iron-containing nanobiocomposite on the erythrocytic system in experimental anemia has been studied. It has been shown that ferroarabinogalactan produces an iron-stabilizing effect; its use qualitatively corrects iron deficiency and reduces manifestations of anemia.     

The role of lung afferent system in respiratory control during head-down tilt

The role of lung receptors in respiratory control during acute head-down tilt (AHDT, -30 degrees) was investigated in anesthetized, tracheostomized rats. The results show that AHDT increased the mechanical respiratory load, slowed inspiratory flow, reduced the end expiratory lung volume, tidal volume and minute ventilation. On the other hand, during AHDT a significant rise in inspiratory swings of oesophageal pressure was recorded indicated a compensatory increase in inspiratory muscle contraction force. These effects were reduced after transaction of the vagus nerve. It was also shown that respiratory response on added mechanical load was reduced during AHDT as compared with the value in horizontal position. This deference disappeared after vagotomy. The data obtained suggested that afferent information from lung receptors take part in compensation of respiratory effects of AHDT. The cause of reduction in respiratory response to loading during AHDT involves weakness of lung reflexes evoked by volume changes.     

Optimization of function of breath by means of training with additional resistive resistance

Research on studying influence of the rate of muscular training in conditions of additional resistive resistance to breath on a level of physical working capacity, aerobic productivity and a functional condition of system of breath was performed. It is shown, that regular muscular loadings in a combination to resistive resistance to breath in a mode of an interval exposition provide an increase of profitability and efficiency of functioning of breathing system as expressed in increase of expiratory force respiratory muscles, rationalization of parity of volumetric-time parameters of breath pattern that promotes more effective gas exchange and decrease in power cost of respiratory movements and as a result leads to increase in aerobic productivity and growth of the general and special working capacity. At continuous exposition of resistive resistance against a background of muscular training, the increase of inspiratory force of respiratory muscles, increase of functional capacity of system of breath were revealed at physical activity as well as a significant gain of the general physical working capacity.     

Synthesis of the tobacco mosaic virus in blocked spreading of infection

The possibility of infection of tobacco upper leaves with tobacco mosaic virus (TMV) was examined in experiments where the inoculum was imbibed through the cut stem. The inoculum used were: a) a preparation of a virus-specific informosome-like ribonucleoproteins (vRNP) isolated from TMV-infected plants; b) a TMV preparation; or c) a mixture of TMV and vRNP. Multiplication of TMV in upper leaves was observed in neither of the variants; nevertheless in the vascular tissue and/or probably in adjoining parenchymal cells, two kinds of RNA were synthesized: of mol. w. (1.1--1.3) X 10(6) and (0.6--0.8) X 10(6). These RNA were not found in healthy plants in the presence of actinomycin D. The synthesis of genomic TMV RNA is suppressed under these conditions. Thus, some kind of abortive TMV infection takes place under the condition of experimental inoculation of plants through a cut stem. Molecular hybridization with the DNA of recombinant plasmid containing a nucleotide sequence complementary to the 3'-portion of genomic TMV RNA proves that short RNAs synthesized under the abortive infection conditions are TMV-specific. The experiments with differential temperature treatment of N-gene-containing plants under abortive infection conditions suggest that necrotization is not necessarily induced by genomic TMV RNA synthesis.     

Transplantation of Stem/Progenitor Cells of Human Brain into Adult Rat Brain

We studied the development of stem/progenitor cells of the human brain transplanted in the adult rat brain after expansion in an in vitrotissue culture. It was preliminarily shown by the immunological methods that the stem cells grown in a medium with growth factors formed neurospheres, which were heterogenous and contained both stem and progenitor cells of the human brain. The cells were implanted in the hippocampus, striatum, or lateral ventricle of the rat brain as a suspension or aggregates (neurospheres) and their behavior and differentiation were studies within 10, 20, and 30 days using the morphological and immunochemical methods. The cultured cells of the human brain continued their development in the rat brain, migrated, and formed neurons and astrocytes. The white mater fibers, lateral ventricle wall, and perivascular spaces served as the main pathways of migration. The neuronal differentiation was shown by staining with antibodies to -tubulin III, neurofilaments-70, and calbindin. Some growing nerve cells had long processes with growth cones. At the same time, some transplanted cells retained the undifferentiated state within one month after the implantation, as shown by the vimentin expression.