Peculiarities of brain mechanisms of regulation of level of wakefulness and of cognitive activity in children with retardation of psychic development and in healthy children of the same age

The work opens possibilities of the of modifications of the developed at the Laboratory systemic-integrative psychophysiological approach to study of the age-related organization or of deviation from norm in formation of superslow informational-controlling brain systems participating in mechanisms of regulation of the wakefulness level and of cognitive activity in the 5–7-year old healthy children and in children of the same age group with retardation of psychic and speech development of the cerebral-organic genesis. There are disclosed peculiarities of organization of: (a) cortical-brainstem and limbic-reticular mechanisms of regulation of the level of wakefulness; (b) suprasegmentary mechanisms of autonomic, hemodynamic, and oxygen-dependent energy supply of the wakefulness level in the examined children’s contingent. There are substantiated concepts about interrelations of peculiarities of the level of actual development of emotional and cognitive spheres with age-related peculiarities or disturbances of formation of mechanisms of regulation of the wakefulness level, its autonomic and hemodynamic provision as well as of the oxygen-dependent energetic potential.     

An Alteration in ELMOD3, an Arl2 GTPase-Activating Protein,Is Associated with Hearing Impairment in Humans

Exome sequencing coupled with homozygosity mapping was used to identify a transition mutation (c.794T>C; p.Leu265Ser) in ELMOD3 at the DFNB88 locus that is associated with nonsyndromic deafness in a large Pakistani family, PKDF468. The affected individuals of this family exhibited pre-lingual, severe-to-profound degrees of mixed hearing loss. ELMOD3 belongs to the engulfment and cell motility (ELMO) family, which consists of six paralogs in mammals. Several members of the ELMO family have been shown to regulate a subset of GTPases within the Ras superfamily. However, ELMOD3 is a largely uncharacterized protein that has no previously known biochemical activities. We found that in rodents, within the sensory epithelia of the inner ear, ELMOD3 appears most pronounced in the stereocilia of cochlear hair cells. Fluorescently tagged ELMOD3 co-localized with the actin cytoskeleton in MDCK cells and actin-based microvilli of LLC-PK1-CL4 epithelial cells. The p.Leu265Ser mutation in the ELMO domain impaired each of these activities. Super-resolution imaging revealed instances of close association of ELMOD3 with actin at the plasma membrane of MDCK cells. Furthermore, recombinant human GST-ELMOD3 exhibited GTPase activating protein (GAP) activity against the Arl2 GTPase, which was completely abolished by the p.Leu265Ser mutation. Collectively, our data provide the first insights into the expression and biochemical properties of ELMOD3 and highlight its functional links to sound perception and actin cytoskeleton.     

Effects of noradrenaline on neuronal response induced in the motor cortex by conditioned stimuli

In chronic experiments on cats, the effects were investigated of iontophoretic application of the adrenomimetic ephedrine and the -blocker obsidan (propranolol) on neuronal response induced in the motor cortex by conditioned stimulus presentation during performances of instrumental lever-pressing response. Inhibition of background firing activity and response in most neurons induced by conditioned stimuli was produced by ephedrine, whereas obsidan application enhanced this activity. It was concluded that steady, tonic inhibitory action of the noradrenergic system on background and induced firing activity in cortical neurons takes place during free-ranging behavior. Temporary reinforcement of noradrenergic influences could be an important element in mechanisms of external inhibition during stressful situations, aversive effects, and distractive stimuli.A. A. Bogomolets Institute of Physiology, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Neirofiziologiya, Vol. 22, No. 5, pp. 680–688, September–October, 1990.     

G(i) proteins in regulation of water permeability of the rat kidney collecting tube epithelium cell membrane

Principal mechanism of the transepithelial water permeability increase in the kidney collecting ducts in response to vasopressin involves insertion of aquaporin 2 (AQP2) into the apical membrane. Previously we have shown that water permeability of the basolateral membrane also may be increased with stimulation of V2-receptors. It is known that inhibition of G(i)-proteins with pertussis toxin blocks redistribution of AQP2 into the apical membrane following the application of vasopressin or forskolin. The aim of the present study was to investigate potential involvement of G(i)-proteins in regulation of basolateral membrane water permeability. Effect of pertussis toxin on the ability of desmopressin to increase the basolateral membrane osmotic water permeability was investigated, and the expression of Galpha(i)2 and Galpha(i)3 genes under normal conditions and after 2 days of water deprivation were evaluated. We demonstrated that dehydration leds to a 30% increase of Galpha(i)3 mRNA content while the Galpha(i)2 mRNA level remains unchanged. In control experiments, basolateral membrane water permeability increased in response to desmopressin from 59.2 +/- 6.61 to 70.6 +/- 9.2 microm/s (p < 0.05, paired t-test). Pertussis toxin completely blocked this reaction (53.5 +/- 5.18 vs 50.1 +/- 6.50 microm/s, respectively). We conclude that G(i)-proteins participate in the mechanism of the basolateral membrane water permeability increase in response to stimulation of V2-receptors. Clarification of the G(i)-proteins role in this process requires further investigation, but most likely they are involved in regulation of aquaporin transport and insertion into the cell membrane.     

Cell ultrastructure and fatty acid composition of lipids in vegetative organs of <Emphasis Type="Italic">Chenopodium album</Emphasis> L. under salt stress conditions

White goosefoot plants (Chenopodium album L. of the family Chenopodiaceae) grown at various NaCl concentrations (3–350 mM) in the nutrient solution were used to study the cell ultrastructure as well as the qualitative and quantitative composition of fatty acids in the lipids of vegetative organs. In addition, the biomass of Ch. album vegetative organs, the water content, and the concentrations of K⁺, Na⁺, and Cl^– were determined. The growth rates of plants raised at NaCl concentrations up to 200–250 mM were the same as for the control plants grown at 3 mM NaCl; the growth parameters remained rather high even at NaCl concentrations of 300–350 mM. The water content in Ch. album organs remained high at all NaCl concentrations tested. Analysis of the ionic status of Ch. album revealed a comparatively high K⁺ content in plant organs. At low NaCl concentrations in the nutrient solution, K⁺ ions were the dominant contributors to the osmolarity (the total concentration of osmotically active substances) and, consequently, to the lowered cell water potential in leaves and roots. As the concentration of NaCl was increased, the plant organs accumulated larger amounts of Na⁺ and Cl^–, and the contribution of these ion species to osmolarity became increasingly noticeable. At 300–350 mM NaCl the contribution of Na⁺ and Cl^– to osmolarity was comparable to that of K⁺. An electron microscopy study of Ch. album cells revealed that, apart from the usual response to salinity manifested in typical ultrastructural changes of chloroplasts, mitochondria, and the cytosol, the salinity response comprised the enhanced formation of endocytic structures and exosomes and stimulation of autophagy. It is supposed that activation of these processes is related to the removal from the cytoplasm of toxic substances and the cell structures impaired by salt stress conditions. The qualitative and quantitative composition of fatty acids in the lipids of Ch. album organs was hardly affected by NaCl level. These findings are consistent with the high salt tolerance of Ch. album, manifested specifically in retention of growth functions under wide-range variations of NaCl concentration in the nutrient solution and in maintenance of K⁺, Na⁺, and Cl^– content in organs at a constant level characteristic of untreated plants.     

Deeplasmid: deep learning accurately separates plasmids from bacterial chromosomes

Plasmids are mobile genetic elements that play a key role in microbial ecology and evolution by mediating horizontal transfer of important genes, such as antimicrobial resistance genes. Many microbial genomes have been sequenced by short read sequencers and have resulted in a mix of contigs that derive from plasmids or chromosomes. New tools that accurately identify plasmids are needed to elucidate new plasmid-borne genes of high biological importance. We have developed Deeplasmid, a deep learning tool for distinguishing plasmids from bacterial chromosomes based on the DNA sequence and its encoded biological data. It requires as input only assembled sequences generated by any sequencing platform and assembly algorithm and its runtime scales linearly with the number of assembled sequences. Deeplasmid achieves an AUC–ROC of over 89%, and it was more accurate than five other plasmid classification methods. Finally, as a proof of concept, we used Deeplasmid to predict new plasmids in the fish pathogen Yersinia ruckeri ATCC 29473 that has no annotated plasmids. Deeplasmid predicted with high reliability that a long assembled contig is part of a plasmid. Using long read sequencing we indeed validated the existence of a 102 kb long plasmid, demonstrating Deeplasmid''s ability to detect novel plasmids.     

Millimeter‐scale genetic gradients and community‐level molecular convergence in a hypersaline microbial mat

To investigate the extent of genetic stratification in structured microbial communities, we compared the metagenomes of 10 successive layers of a phylogenetically complex hypersaline mat from Guerrero Negro, Mexico. We found pronounced millimeter‐scale genetic gradients that were consistent with the physicochemical profile of the mat. Despite these gradients, all layers displayed near‐identical and acid‐shifted isoelectric point profiles due to a molecular convergence of amino‐acid usage, indicating that hypersalinity enforces an overriding selective pressure on the mat community.     

Antiinfluenza virus effect of extracts from marine algae and invertebrates

Sixty products, derived from marine organisms, typical of the Bulgarian Black Sea coast, were examined for inhibitory activity on the reproduction of influenza viruses in tissue cultures. The antiviral effect was investigated by the reduction of virus infectivity. Using representative strains of influenza virus it was shown that apparently the inhibitory effect was strain-specific. The most effective products were further studied in fertile hen's eggs and in experimental influenza infection in white mice.     

Role of Oxidative Metabolism in the Energy Suppply of Active Potassium Transport in Erythrocytes of the Lamprey Lampetra fluviatilis

To study role of glycolysis and oxidative metabolism in providing active transport of monovalent cations, isolated erythrocytes of the lamprey Lampetra fluviatlis were incubated at 20°C in the presence of various metabolic inhibitors. The active (ouabain-sensitive) K⁺ (⁸⁶Rb) influx into erythrocytes did not change after cell incubation for 1–2 h in the absence of glucose or in the presence of 10 mM deoxy-D-glucose or 1 mM monoiodoacetate. Inhibitors of oxidative phosphorylation (antimycin A, rotenone, sodium azide, cyanide) produced a significant decrease (on average, by 74% ) in the active K⁺ transport in the lamprey erythrocytes. All blockers of oxidative phosphorylation produced the same degree of inhibition of the K⁺ transport after the cell pre-incubation with them for 30 and 60 min. In experiments with rotenone, the K⁺ influx was reduced statistically significantly as early as in 5 min of cell incubation and reached a maximal effect after 10–20 min. The intracellular ATP content in erythrocytes decreased by 17, 37, and 45% after 5, 10, and 20 min of cell incubation with rotenone, respectively. The active K⁺ transport in the lamprey erythrocytes is most likely to be closely associated with the intracellular ATP concentration. The data obtained indicate that the energy supply of the Na,K-pump in the lamprey erythrocytes is due exclusively to oxidative phosphorylation processes.     

Reagents for Modification of Protein–Nucleic Acid Complexes: III.1Site-Specific Photomodification of Elongation Complex of DNA Polymerase β with Arylazide Derivatives of Primers Sensitized with Fluorescent ATP γ-Amides

ATP -amides containing in -N-position 1-methylpyrene, 9-methylanthracene, 10-chloro-9-methyl-anthracene, and 3-methylperylene residues were synthesized and characterized. These compounds were used as sensitizers of site-specific photomodification of the reconstituted elongating complex of the mammalian DNA polymerase . The photomodification was carried out with the use of photoaffinity reagents, which were synthesized in situby the 5"-³²P-labeled primers extension with photoreactive analogues of dCTP containing in the exo-N-position of cytosine various perfluoroarylazide groups. The effect of structures of the sensitizers and photoreactive reagents on the efficiency and selectivity of photocrosslinking of primers to the enzyme and template, as well as formation of a number of other photomodification products was studied. It was shown that the sensitizers containing 10-chloro-9-methylanthracene and 3-methylperylene residues allow one to obtain photocrosslinks under such irradiation conditions when photomodification in their absence is not essentially observed.