Search for biocontrol agents among endophytic lipopeptide-synthesizing bacteria Bacillus spp. to protect wheat plants against Greenbug aphid (Schizaphis graminum).

Beneficial endophytic bacteria can suppress the development of insect pests through direct antagonism, with the help of metabolites, or indirectly by the induction of systemic resistance through the regulation of hormonal signaling pathways. Lipopeptides are bacterial metabolites that exhibit direct antagonistic activity against many organisms, including insects. Also, lipopeptides are able to trigger induced systemic resistance (ISR) in plants against harmful organisms, but the physiological mechanisms of their action are just beginning to be studied. In this work, we studied ten strains of bacteria isolated from the tissues of wheat and potatoes. Sequencing of the 16S rRNA gene showed that all isolates belong to the genus Bacillus and to two species, B. subtilis and B. velezensis. The genes for lipopeptide synthetase - surfactin synthetase (Bs_srf ), iturin synthetase (Bs_ituA, Bs_ituB) and fengycin synthetase (Bs_fenD) - were identified in all bacterial isolates using PCR. All strains had high aphicidal activity against the Greenbug aphid (Schizaphis graminum Rond.) due to the synthesis of lipopeptides, which was proven using lipopeptide-rich fractions (LRFs) isolated from the strains. Endophytic lipopeptide-synthesizing strains of Bacillus spp. indirectly affected the viability of aphids, the endurance of plants against aphids and triggered ISR in plants, which manifested itself in the regulation of oxidative metabolism and the accumulation of transcripts of the Pr1, Pr2, Pr3, Pr6 and Pr9 genes due to the synthesis of lipopeptides, which was proven using LRF isolated from three strains: B. subtilis 26D, B. subtilis 11VM, and B. thuringiensis B-6066. We have for the first time demonstrated the aphicidal effect of fengycin and the ability of the fengycin-synthesizing strains and isolates, B. subtilis Ttl2, Bacillus sp. Stl7 and B. thuringiensis B-6066, to regulate components of the pro-/antioxidant system of aphid-infested plants. In addition, this work is the first to demonstrate an elicitor role of fengycin in triggering a systemic resistance to S. graminum in wheat plants. We have discovered new promising strains and isolates of endophytes of the genus Bacillus, which may be included in the composition of new biocontrol agents against aphids. One of the criteria for searching for new bacteria active against phloem-feeding insects can be the presence of lipopeptide synthetase genes in the bacterial genome.

The Effect of TLR Agonists and Myokines on Secretory Activity of Adipogenically Differentiated MSC Cultures.

We studied the effect of bacterial pathogen-associated molecular patterns and myokines on the secretion of adipokines by mesenchymal stem cells (MSC) and products of their adipogenic differentiation. The secretion of adiponectin, adipsin, leptin, and insulin by adipogenically differentiated cell cultures was quantitatively determined using multiplex ELISA. MSC obtained from the stromal vascular fraction of human subcutaneous adipose tissue were shown to secrete a known adipokine adipsin. The ability of white adipocytes to secrete significant amounts of insulin (in vitro) has been shown for the first time. Control cultures of white adipocytes secreted much higher levels of adiponectin, leptin, and insulin when compared to other adipocytes cultures. On the other hand, beige and brown adipocyte cultures secreted more adipsin than white adipocyte cultures. The influence of myokine ß-aminoisobutyric acid on the secretion of adipsin in MSC, white, beige, and brown adipocytes was also studied.

The Effect of LPS and Flagellin on the Process of Lipolysis in Mesenchymal Stromal Cells during Adipogenic Differentiation.

We analyzed the effects of bacterial pathogen-associated molecular patterns (LPS and flagellin) and adrenergic agonist isoproterenol on the content of total and phosphorylated (Ser552) hormone-sensitive lipase in mesenchymal stromal cells and cell products of their adipogenic differentiation. The expression of hormone-sensitive lipase and an increase in the content of its activated phosphorylated form were demonstrated by Western blotting in cells of all three lines of adipogenic differentiation. Under the influence of flagellin, the content of total and phosphorylated forms of hormone-sensitive lipase increased in brown adipocytes, while LPS induced a decrease in the content of total hormone-sensitive lipase in white adipocytes. We hypothesize that bacterial pathogen-associated molecular patterns can activate lipolysis under pathological conditions associated with slow remodeling of the adipose tissue.

[The study of tryptophan metabolite concentrations in blood serum and fecal extracts from obese children]. / Izuchenie soderzhaniia metabolitov obmena triptofana v syvorotke krovi i kalovykh ékstraktakh u detei s ozhireniem.

We found that changes in the concentrations of tryptophan metabolites in the blood serum and in the intestinal contents are one of the mechanisms for the formation of metabolic coupling in the system "macroorganism-intestinal microbiota", which undergoes significant changes in the development of obesity. Although blood kynurenine remained basically unchanged in obese children we found an increase in some of its serum metabolites: anthranilic, kynurenic and xanthurenic acids. It is noteworthy that in the analysis of fecal matter in obese children, revealed a 2-fold increase in the level of kynurenine while the concentration of kynurenine pathway metabolites corresponded to the level of the group of healthy children. This may indicate the metabolic activation of the microbiota associated with the intestinal mucosa. This is also supported by the absence of statistically significant differences in the concentration of indole in healthy children and in obese children in fecal analyses, and a significant increase in the concentration of indole-3-lactate and indole-3-acetate in the blood serum of obese children.

Proton-irradiation-immune electronics implemented with two-dimensional charge-density-wave devices.

We demonstrate that charge-density-wave devices with quasi-two-dimensional 1T-TaS2 channels show remarkable immunity to bombardment with 1.8 MeV protons to a fluence of at least 1014 H+cm-2. The current-voltage characteristics of these devices do not change as a result of proton irradiation, in striking contrast to most conventional semiconductor devices or other two-dimensional devices. Only negligible changes are found in the low-frequency noise spectra. The radiation immunity of these "all-metallic" charge-density-wave devices is attributed to the quasi-2D nature of the electron transport in the nanoscale-thickness channel, high concentration of charge carriers in the utilized charge-density-wave phases, and two-dimensional device design. Such devices, capable of operating over a wide temperature range, can constitute a crucial segment of future electronics for space, particle accelerator and other radiation environments.

[Humoral regulation of nutritional status in children].

The purpose of the research was the investigation of the characteristics of insulin resistance, levels of adipokines, myokines and collagen metabolites type I in children in orphanages and social rehabilitation centers (SRC). The study involved 69 children aged 7-12 years. The first group consisted of 20 children from SRC, the second - 16 children living in orphanages, control group included 33 children (1-2 health groups) from wealthy families. The average length of stay of children in SRP was 1.0 (0.5-2.5) month, in orphanages - 38 (22-44) months. The groups were comparable in age and sex. Anthropometric indices were determined, in blood serum glucose concentration was measured by glucose oxidase method, blood serum level of insulin, cortisol, leptin, adiponectin, resistin, apelin, myostatin, collagen metabolites were determined by ELISA. Children from orphanages and SRC had significantly lower anthropometric indices in comparison with the control group. Particularly low parameters were observed in children from SRP, which in growth, body weight, chest circumference and body mass index significantly lagged behind the control group peers. The children from SRP as compared with the control group revealed higher insulin resistance index (3.33±0.49 vs 2.29±0.29, p<0.05) and cortisol level (405.21±38.21 vs 313.08±25.97 nmol/l, p>0.05). There were changes (p<0.05) in blood serum content of adipokines - reduced leptin level (5.35±1.55 vs 14.00±3.10 ng/ml) and increased apelin level (4.07±0.82 vs 2.19±0.41 ng/ml), as well as higher levels (p<0.05) of myostatin (183.95±16.3 vs 116.4±9.4 ng/ml) and C-terminal telopeptide of type I collagen (1.11±0.11 vs 0.72±0.08 ng/ml). The children in orphanages compared with the control group had lower levels of insulin (5.04±0.69 vs 11.3±1.12 µIU/ml), high insulin sensitivity - HOMA-IR was 1.01±0.16. The children in orphanages have even more pronounced reduction in leptin concentration (2.69±0.4 ng/ml), a decrease of resistin (4.99±0.32 vs 7.16±0.70 ng/ml, p<0.05), increased concentration (p<0.05) of apelin (3.53±0.67 ng/ml), myostatin (181.17±10.2 ng/ml) and C-terminal telopeptide of type I collagen (2.70±0.22 ng/ml). Features of hormone and cytokine regulation of metabolism make it particularly urgent to prevent disorders of eating behavior and to promote a healthy lifestyle among children left without parental care.

Nanometer size field effect transistors for terahertz detectors.

Nanometer size field effect transistors can operate as efficient resonant or broadband terahertz detectors, mixers, phase shifters and frequency multipliers at frequencies far beyond their fundamental cut-off frequency. This work is an overview of some recent results concerning the application of nanometer scale field effect transistors for the detection of terahertz radiation.

Study of genetic stability of human bone marrow multipotent mesenchymal stromal cells.

Immunophenotype, proliferation rate, and genetic stability parameters of bone marrow multipotent mesenchymal stromal cells were studied. Despite the reduction of proliferative activity by passages 11-12, the cells retained the characteristic immunophenotype. The incidence of spontaneous aneuploidy for autosomes 6, 8, 11 and sex chromosomes was evaluated. Two cultures of mesenchymal stromal cells carrying aneuploid cell clones were detected: with chromosome 8 trisomy and X chromosome monosomy. The results indicate the possibility of genetic transformation and selection of mesenchymal stromal cells with abnormal karyotype during in vitro culturing.

Electrical and noise characteristics of graphene field-effect transistors: ambient effects, noise sources and physical mechanisms.

We fabricated a large number of single and bilayer graphene transistors and carried out a systematic experimental study of their low-frequency noise characteristics. Special attention was given to determining the dominant noise sources in these devices and the effect of aging on the current-voltage and noise characteristics. The analysis of the noise spectral density dependence on the area of graphene channel showed that the dominant contributions to the low-frequency electronic noise come from the graphene layer itself rather than from the contacts. Aging of graphene transistors due to exposure to ambient conditions for over a month resulted in substantially increased noise, attributed to the decreasing mobility of graphene and increasing contact resistance. The noise spectral density in both single and bilayer graphene transistors either increased with deviation from the charge neutrality point or depended weakly on the gate bias. This observation confirms that the low-frequency noise characteristics of graphene transistors are qualitatively different from those of conventional silicon metal-oxide-semiconductor field-effect transistors.

An ultra-stable non-coherent light source for optical measurements in neuroscience and cell physiology.

We demonstrate that high power light-emitting diodes (LED's) exhibit low-frequency noise characteristics that are clearly superior to those of quartz tungsten halogen lamps, the non-coherent light source most commonly employed when freedom from intensity variation is critical. Their extreme stability over tens of seconds (combined with readily selectable wavelength) makes high power LED's ideal light sources for DC recording of optical changes, from living cells and tissues, that last more than a few hundred milliseconds. These optical signals (DeltaI/I(0)) may be intrinsic (light scattering, absorbance or fluorescence) or extrinsic (absorbance or fluorescence from probe molecules) and we show that changes as small as approximately 8 x 10(-5) can be recorded without signal averaging when LED's are used as monochromatic light sources. Here, rapid and slow changes in the intrinsic optical properties of mammalian peptidergic nerve terminals are used to illustrate the advantages of high power LED's compared to filament bulbs.

Toward molecular level of the "Salmonella-victim" ecology, genetics, and evolution.

Bacteria of the Salmonella genus are polypathogenic agents that can affect both men and animals, causing devastating and fatal illness. Despite considerable immunological, epidemiological, and genetic efforts, and increased understanding of how the Salmonella infection develops, many key questions concerning Salmonella infection remain unanswered. Salmonella can be carried as harmless commensals in some sectors of the population. In some individuals, however, the same microbes cause illness while others display immunity to primary Salmonella infection. Nothing is known about the molecular base of the Salmonella pathogenicity. Even the ability of Salmonella to destroy the victim's cells has been the subject of century-long discussions. In this article, some key findings concerning ecology, molecular ecology, and cell level of the Salmonella infection genetics are summarized and interpreted from the viewpoint of evolutionary theory with certitude that this approach can help to decipher the undiscovered secrets of Salmonella infection's epidemiology and pathogenesis, as well as the clinical course and severity, and to select ways for fighting against Salmonella.

Species, population and age diversity in cell resistance to adhesion of Neisseria meningitidis serogroups A, B and C.

The variation of cell adherence of meningococci serogroups A, B and C and influenza viruses was investigated in 11 animal species and in humans of different age groups (1st, 2nd, 3rd and 4th weeks; 2nd-3rd months; 4th-12th months, 2nd-3rd years; and 18th-60th years of life) as well as in women during pregnancy (17th-36th weeks) and childbirth. Red blood cells of all animals tested as well as of human newborns were absolutely resistant to attachment of meningococci. In neonatal and the later periods the human cells become far differently sensitive individually to meningococcal adhesion. In contrast, the viral adhesion was characterized by different individual cell sensitivity in all age groups tested. Pregnancy and childbirth did not influence the women's cell sensitivity to adhesion of Neisseria meningitidis. Different receptors are involved in interactions of human cells with influenza viruses and meningococci. The function of meningococcal receptors on human cells develops during postnatal ontogenesis. The variations express both specific (genetic) and ontogenetic (individual) differences in natural resistance to meningococcal infection.

Constitutional and non-specific immunity to infection.

Most immunologists focus on elaborate non-specific and antigen-specific factors of reactive immunity produced by the vertebrate lymphoid system. Modern principles of immunogenic prophylaxis and therapy are based solely on the use of these agents. There is, however, a more effective system of specific resistance which is shared by all forms of life: hereditary constitutional immunity to infection and invasion. An explosive growth in knowledge of the constitutional immunogenic system has occurred during the past two decades. The author illustrates the nature and importance of constitutional immunity, using examples from genetics and molecular biology. Special attention is given to testing for genetic susceptibility to infection and genetic engineering of resistance.

Chemical ecology and biomolecular evolution .

The belief in the Darwinian theory of evolution appeared to be shaken when one tried to interpret statements of molecular biology in it. As a consequence there arose a theory of non-Darwinian neutral evolution. The supporters of this theory believe that under natural conditions no factors exist which can distinguish and select organisms on their internal (molecular) structure. In the opinion of these neutralists natural selection cannot in principle control the molecular constitution of organisms. Contrary to the viewpoint of the critics of neutralism it is impossible to admit that nucleic acids, proteins and other biomolecules can evolve without the participation of natural selection. This controversy in contemporary theoretical biology can be solved by integrating the conceptions of molecular ecology with Darwinian theory. Molecular ecology acknowledges the interactions of organisms by means of chemical substances synthesized by them. Such chemical ecological factors play a leading part in the selective stages of biomolecular evolution. These diverse chemical ecological interrelations take place intensively when living beings interact with parasitic microbes.

Pathogenic effects of the human chemical biofield.

Organisms release their antigens into the environment. Some antigens are volatile and may pass into the blood of other organisms during respiration. Fetal antigens enter the mother's bloodstream through the placenta. Foreign antigens in the blood can cause various chemical changes and may initiate an immune reaction.

Observations on constitutional resistance to infection.

The attention of most immunologists is held by the elaborate nonspecific and antigen-specific mechanisms of reactive immunity. There is, however, a more fundamental level of immunity to infection that is shared by all forms of life: constitutional resistance to infection. In this article, the nature and importance of constitutional immunity is illustrated using examples from population, cell and molecular biology.