Effect of hyperglycemia and hyperthermia on liver mitochondrial respiration and blood glucose content of rats during postnatal ontogenesis]

Correlation between glucose level in blood and liver mitochondrial energetics of 1, 10, 20-days rats under hyperglycemia and high environmental temperature (38 degrees C) has been studied. Glucose feeding led to a significant increase of glucose content in blood, this increase being less at hyperthermia. Glucose feeding strengthened the oxidation of such intermediates as succinate (Krebs cycle), pyruvate and malate (hydrocarbonates) and caprylate (lipid). High environmental temperature with hyperglycemia suppresses the liver mitochondria breathing, hydrocarbon and lipid intermediates being used; the suppression is less in the presence of succinate. It is found that liver mitochondria of growing rats at different experimental conditions oxidize different intermediates with various rates. These data can be explained in the light of ontogenetic evolution of the energetic apparatus. It is supposed that exogenic glucose is the factor which activates growing processes of animals and to certain extent diminishes the negative influence of hyperthermia on the organism.     

Study of the Ion Composition of the Diffuse Vacuum Arc on a Hot Cathode by the Time-of-Flight Method

Plasma Physics Reports - The study of a diffuse vacuum arc (DVA) is of interest in connection with the developing methods of plasma processing of the spent nuclear fuel (SNF). This type of...     

On the role of gene of SER-4 serotonin receptor in thermotolerance of Caenorhabditis elegans behavior

Serotonin reduces the behavior tolerance of Caenorhabditis elegans of the N2 wild-type strain (swimming induced by the mechanical stimulus) to a temperature of 36°C. The sensitivity to the serotonin influence on the behavior thermotolerance remains intact in strains with null mutations of mod-1(ok103) and ser-1(ok345) serotonin receptor genes, and is almost completely lost in the ser-4(ok512) strain with null mutation in the gene of the SER-4 serotonin receptor, which is a homologue of 5-HT₁ mammalian serotonin receptor. In addition, nematodes of the ser-4(ok512) strain have high behavior thermotolerance in the absence of the exogenous serotonin compared to the N2 strain. These data indicate the involvement of the ser-4 gene in the serotonin regulation of the tolerance of C. elegance nervous system functions to hyperthermia.     

Chirped dissipative ion-cyclotron solitons in the Earth’s low-altitude ionospheric plasma with two ion species

Conditions for the excitation of small-scale nonlinear ion-cyclotron gradient-drift dissipative structures in cold ionospheric plasma are considered. The solution for the wave electric field in this structure in the form of a chirped soliton satisfying the equation of the Ginzburg-Landau type is derived in the electrostatic approach. The dissipative structure as a whole represents the chirped soliton accompanied by the comoving quasineutral plasma hump. The possibility of the excitation of two modes of this type (the high- and low-frequency ones) in plasma containing light and heavy ion impurities is considered. The role of electromagnetic corrections and the possible contribution introduced by these structures to the transport processes in the ionosphere are discussed.     

Study of regulation of some key enzymes of L-alanine biosynthesis by Brevibacterium Flavum producer strains

The mechanisms of L-alanine overproduction by Brevibacterium flavum strain-producers were studied. It was shown that β-Cl-L-alanine is an inhibitor of some key enzymes involved in the synthesis of L-alanine: alanine transaminase and valine-pyruvate transaminase. Two highly active B. flavum GL1 and GL18 strain-producers, which are resistant to the inhibitory effect of β-Cl-L-alanine, were obtained using a parental B. flavum AA5 strain-producer, characterized by a reduced activity of alanine racemase (≥98%). It was demonstrated that the increased L-alanine synthesis efficiency observed in the strain-producer developed in this work is associated with the absence of inhibition of alanine transaminase by the end product of the biosynthesis reaction, as well as with the effect of derepression of both alanine transaminase and valine-pyruvate transaminase synthesis by the studied compound.     

Two populations of pluripotent stem cells in planarians <Emphasis Type="Italic">Girardia tigrina</Emphasis>

The positional differences in the regenerative capability of individual body parts of the planarian Girardia (Dugesia) tigrina were analyzed. The paper shows the significance of the size and positional differences of individual fragments of planarians for their regenerative capabilities, as well as the fundamental difference in the mechanisms of the head and tail blastema formation. A scheme of regeneration that includes two populations of pluripotent stem cells called neoblasts is suggested. The two populations of neoblasts differ in their role and distribution along the planarian body. Specifically, the population of neoblasts involved in the formation of any blastema migrates to the nearest blastema, and the population participating only in the creation of the head blastema migrates along the planarian body, following the gradient of biomass of the damaged axons arising after the amputation of the head end. The maximal size of the head blastema was found in the fragment obtained after cutting off the head fragment at the eye level, and the maximal portion of all pluripotent stem cells migrating into two blastemas was found in the fragment obtained by cutting the planarian above the mouth, followed by cutting off the head fragment at the eye level.     

Horizontal distribution of the cell abundance and toxicity of <Emphasis Type="Italic">Microcystis</Emphasis> in a hypereutrophic Moroccan reservoir

The first results of the horizontal distribution of the cell abundance and toxicity of Microcystis in the hypereutrophic Moroccan reservoir Lalla Takerkoust are reported. An unexpected spatio-temporal heterogeneity has been shown between Microcystis abundance and microcystins concentrations. The principal determining factors were analyzed in order to identify the most likely sites for the proliferation and/or accumulation of Microcystis in this reservoir. The horizontal heterogeneity seems to be mainly influenced by the wind direction and inflows. The results can serve as reference data for monitoring cyanobacterial water blooms and associated cyanotoxins in the lake.     

Development of nanostructured phosphorite: Study of the safety of application

A nanostructured mineral food supplement with a particle size of 60.0–120.0 nm was manufactured from phosphorite by ultrasonic dispersion. It was found that intragastric administration of nanostructures phosphorite to mice is relatively safe: clinical signs of intoxication appeared after a single administration of the preparation only at a dose of 90 mg/kg; a dose of 150 mg/kg caused death of 8% of mice, in which injuries of organs of the gastrointestinal tract were observed. When the preparation was administered subcutaneously, intramuscularly, or intraperitoneally, small phosphorite conglomerates and inflammation of the surrounding tissues and organs were observed at the injection site. Death of 25% of animals was observed in the group of mice which received intraperitoneal injections of nanophosphorite at a dose of 200 mg/kg.