Izvestiia Akademii nauk. Seriia biologicheskaia最新文献

It is shown that the effect of 5-fluorouracil (5-FU) on mesenchymal stromal cells (MSCs) of the bone marrow and fetal liver of the rat increases the population of cells with a reduced proliferative potential. It is shown that, in the course of passaging, the 5-FU-resistant MSCs of the bone marrow and fetal liver lose their ability to differentiate in the osteogenic direction more and less rapidly, respectively, than the 5-FU-sensitive MSCs.

Species classification of a strain of the bacterium oil-destructor Acinetobacter sp. I B DT-5.1/l is established by means of gas chromatography-mass spectrometry fatty acid methyl esters in the cell wall and matrix-assisted laser desorption/ionization (MALDI) mass spectrometry of proteins of a cell.

In this paper we report the results of testosterone manipulation in the blood of male Campbell dwarf hamsters Phodopus campbelli Thomas, 1905 through castration, followed by testosterone treatment. Under these conditions, we studied antibody production rates in response to injection with sheep red blood cells (SRBC). It was shown that castration induced a dramatic decrease in blood testosterone but had no effect on the humoral response to SRBC. Males that received a testosterone compound with a long-lasting action (omnadren) exhibited a poor response to SRBC following re-exposure in the context of elevated testosterone compared to castrated males inoculated with an oil base of the drug.

The use of the buccal mucosa cell micronucleus test for comparison of chemical, radiation, and radiation-chemical environmental pollution has been considered. The combined impact of chemical and radiation factors has been found to cause additive effects, synergism, and inhibition. It has been noted that the cytogenetic characteristics of the buccal epithelium may be used as a "biological dosimeter" of the total level of environmental pollution.

Information on the effect of hypoxia on the behavior and physiological state of the honeybee was compiled and systematized. It was shown that, in the course of colonization of temperate and cold climate zones by the honeybee, natural selection favored the acquisition of an effective mechanism of thermoregulation and high tolerance to hypoxia. It was noted that bees can develop under conditions when the CO2 concentration exceeds the content of this gas in the surface layer of the Earth by more than three orders of magnitude; however, this leads to deviations in the morphometric traits from the norm. At the adult stage, anesthesia with carbon dioxide was found to reduce the body weight and the water content in it. It was shown that the effect of anesthesia in adult bees increases with temperature and that hypoxia in adult bees and queens accelerates their senescence and reduces viability.

The effects of serotonin receptor activation (by serotonin) and inhibition (by mianserin) on the properties of the α1-, α2-adrenoreceptors, and muscarinic cholinergic receptors in subcellular membrane fractions from the rat cerebral cortex were studied. Experimental data on the kinetics of specific antagonists binding to adrenergic and muscarinic receptors were analyzed by graphical and mathematical methods. The results suggest the presence of allosteric (cross-talk) interaction. In the control, α1- and α2-adrenoreceptors were represented by a single pool, and muscarinic receptors, by two pools. Two pools of adrenoreceptors with different affinity were detected against the background of serotonin. It was found that mianserin induces the formation of two pools of only (α2-receptors and muscarinic receptors are represented by two pools differing in the main parameters, such as dissociation constants and adrenoreceptor concentrations, in the control and experimental groups. It was shown that the allosteric effect of serotonin and mianserin is manifested in the inhibition of muscarinic receptors. It was assumed that the adrenergic and cholinergic receptors exist as dimers. The interaction between the adrenergic, cholinergic, and serotonergic systems is likely to be implemented at the cell membrane level.

The diversity and viability of prokaryotic communities in the primitive organomineral soils of East Antarctica have been studied; it has been shown that the total number of bacteria is smaller than and the viability of bacteria is similar to that in soils of the temperate zone. The prokaryotic communities are characterized by the occurrence of a major part of cells in filterable forms, which is higher than the analogous parameter for the temperate soils. The method of fluorescence in situ hybridization (FISH) revealed that the distribution of the main taxons is similar to that in the temperate soils: the portion of the domain Archaea is smaller than that of the domain Bacteria; the total content of Gram-negative bacteria (the phyla Proteobacteria, Acidobacteria, and Planctomycetes) is higher than that of Gram-positive bacteria (Actinobacteria). Within the phylum Proteobacteria, a significant variation of three proteobacterial classes has been noted along the profiles of the soils studied.

An association between the cerebrum electrical activity (CEA) in rats, blood supply of its cortex microregions (linear blood flow), and general cerebrum blood flow under acute nitrite hypoxia was studied. The phase character of the change in hemodynamic indices and the total capacity of electroencephalography (EEG) spectrum for 75 min after sodium nitrite introduction (30 mg/kg of body weight) was detected. The first phase (30 min) was associated with cerebrum adaptation to hypotension caused by nitrite and was completed by EEG normalization. The second phase was characterized by pathological EEG changes (in spite of restoration of hemodynamics in the cerebrum) caused by the growth of oxygen debt in the nervous tissue as a result of a decrease in the blood oxygen capacity by 60-75 min of the effect of nitrite.

The effect of abscisic acid (ABA) and fluridone on the content of endogenous phytohormones and free polyamines and the intensity of oxidative stress was studied in plants of Mesembryanthemum crystallinum L. under salinity. It was shown that the pretreatment of plant roots with 1 μM ABA, followed by the action of 300 mM NaCl, caused a protective effect and improved the physiological state of the plants, which was manifested in increased biomass and content of available cytokinins and reduced values of the indicators of oxidative stress. It was noted that the inhibitor fluridone reduced the effect of ABA and acted as a pro-oxidant.

The cytomorphological and biochemical composition of the blood has been studied for the deep-dwelling (bottom) morphotype of the Baikal omul infected by plerocercoids of Diphyllobothrium dendriticum, during the fish spawning migration. A decrease in hemoglobin synthesis and an increase in the proliferative activity of erythroid cells have been registered. The changes in the leukocyte population composition, immunoglobulin, and total protein concentrations evidenced a disorder of blood cell proliferation and differentiation and suppression of the immune response in the infected fish. The changes in the humoral and cell factors of homeostasis in Coregonus migratorius infected by D. dendriticum during the spawning period remain within the limits of the adaptive possibilities of the species.