The role of interleukin-33 in pathogenesis of bronchial asthma. New experimental data

Interleukin-33 (IL-33) belongs to the IL-1 cytokine family and plays an important role in modulating immune system by inducing Th2 immune response via the ST2 membrane receptor. Epithelial cells are the major producers of IL-33. However, IL-33 is also secreted by other cells, e.g., bone marrow cells, dendritic cells, macrophages, and mast cells. IL-33 targets a broad range of cell types bearing the ST2 surface receptor. Many ST2-positive cells, such as Th2 cells, mast cells, basophils, and eosinophils, are involved in the development of allergic bronchial asthma (BA). This suggests that IL-33 directly participates in BA pathogenesis. Currently, the role of IL-33 in pathogenesis of inflammatory disorders, including BA, has been extensively investigated using clinical samples collected from patients, as well as asthma animal models. In particular, numerous studies on blocking IL-33 and its receptor by monoclonal antibodies in asthma mouse model have been performed over the last several years; IL-33-and ST2-deficient transgenic mice have also been generated. In this review, we summarized and analyzed the data on the role of IL-33 in BA pathogenesis and the prospects for creating new treatments for BA.     

Changes in the cyclic nucleotide level and the inhibition of human thrombocyte aggregation in 3-hydroxypyridine exposure

The effect of six 3-oxypiridine derivatives (at a concentration of 10(-3) and 5 X 10(-3) M) on cyclic nucleotide level in human platelets and platelet aggregation was studied. Five 3-oxypiridine derivatives were shown to depress platelet aggregation, four of them causing the increase in cAMP platelet level. The correlation between antiaggregation activity of 3-oxypiridine derivatives and their ability to rise cyclic nucleotide level in human platelets is discussed.     

Nature of the IR spectra of intact cells of Gram-negative microorganisms

The character of changes in the infrared spectra of E. coli in the process of their mechanical disintegration has been studied. The destruction of E. coli cell structures has been shown to produce no changes in the optical density of the main analytical absorption bands in infrared spectra. This fact suggests that the infrared absorption spectra of E. coli are the sum of the spectra of all chemical components of the cell, which is confirmed by the infrared spectral study of E. coli cell-wall preparations. Similar results have been obtained in the study of the preparations of B. pertussis cell walls, protoplasts and intact cells.     

On the Feasibility of Plasma Separation of Spent Nuclear Fuel Components in a Nonuniform Magnetic Field

Plasma Physics Reports - A new concept of plasma separation of spent nuclear fuel components in a variable-cross-section chamber with a nonuniform magnetic field is proposed. Numerical simulation...     

Phosphate Homeostasis in Conditions of Phosphate Proficiency and Limitation in the Wild Type and the phoP Mutant of Streptomyces lividans

Phosphate, as a constituent of the high energy molecules, ATP/GTP and polyphosphate, plays a crucial role in most of the metabolic processes of living organisms. Therefore, the adaptation to low Pi availability is a major challenge for bacteria. In Streptomyces, this adaptation is tightly controlled by the two component PhoR/PhoP system. In this study, the free intracellular Pi, ATP, ADP and polyP content of the wild type and the phoP mutant strain of S. lividans TK24 were analyzed at discrete time points throughout growth in Pi replete and limited media. PolyP length and content was shown to be directly related to the Pi content of the growth medium. In Pi repletion, ATP and high molecular weight (HMW) polyP contents were higher in the phoP mutant than in the WT strain. This supports the recently proposed repressive effect of PhoP on oxidative phosphorylation. High oxidative phosphorylation activity might also have a direct or indirect positive impact on HMW polyP synthesis. In Pi sufficiency as in Pi limitation, the degradation of these polymers was shown to be clearly delayed in the phoP mutant, indicating PhoP dependent expression of the enzymes involved in this degradation. The efficient storage of Pi as polyphosphate and/or its inefficient degradation in Pi in the phoP mutant resulted in low levels of free Pi and ATP that are likely to be, at least in part, responsible for the very poor growth of this mutant in Pi limitation. Furthermore, short polyP was shown to be present outside the cell, tightly bound to the mycelium via electrostatic interactions involving divalent cations. Less short polyP was found to be associated with the mycelium of the phoP mutant than with that of the WT strain, indicating that generation and externalization of these short polyP molecules was directly or indirectly dependent on PhoP.     

Mortality Caused by Bath Exposure of Zebrafish (Danio rerio) Larvae to Nervous Necrosis Virus Is Limited to the Fourth Day Postfertilization

Nervous necrosis virus (NNV) is a member of the Betanodavirus genus that causes fatal diseases in over 40 species of fish worldwide. Mortality among NNV-infected fish larvae is almost 100%. In order to elucidate the mechanisms responsible for the susceptibility of fish larvae to NNV, we exposed zebrafish larvae to NNV by bath immersion at 2, 4, 6, and 8 days postfertilization (dpf). Here, we demonstrate that developing zebrafish embryos are resistant to NNV at 2 dpf due to the protection afforded by the egg chorion and, to a lesser extent, by the perivitelline fluid. The zebrafish larvae succumbed to NNV infection during a narrow time window around the 4th dpf, while 6- and 8-day-old larvae were much less sensitive, with mortalities of 24% and 28%, respectively.