Publications by authors named "Prokhorenko I"

The persisting presence of opportunistic pathogens like poses a significant threat to many immunocompromised cancer patients with pulmonary infections. This review highlights the complexity of interactions in the host's defensive eicosanoid signaling network and its hijacking by pathogenic bacteria to their own advantage. Human lipoxygenases (ALOXs) and their mouse counterparts are integral elements of the innate immune system, mostly operating in the pro-inflammatory mode.

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The investigation of common inflammation mechanisms caused by exogenic compounds of microbial origin and allergens is one of the most important tasks in current biomedical science. The main manifestations of immune cell activation caused by pro-inflammatory agents are changes in receptor quantity on the surface of immune cells and the production of cytokines and chemokines by blood cells. The levels of expression of TLR4, CD14, and CD11b in the monocytes and neutrophils of human whole blood in response to LPS , Der p 2 allergen, or their combination reflect different functional activities in these cells, while the composition and amount of produced cytokines reflect the biological activity of the studied agonists.

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Epidemiological data indicate the active progression of various forms of diabetes mellitus in patients with bronchial asthma (BA), but little is known about the mechanisms of comorbidity formation. TLR2 and TLR4 are involved in the progression of asthma and type 2 diabetes mellitus (T2DM). These receptors are involved in the inflammatory response to Gram(+) and Gram(-) bacteria, respectively, so changes in their expression may affect the predisposition of patients to bacteremia.

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Lipopolysaccharides (LPS) and lipoteichoic acids (LTA) are the major inducers of the inflammatory response of blood cells caused by Gram-negative and some Gram-positive bacteria. CD14 is a common receptor for LPS and LTA that transfers the ligands to TLR4 and TLR2, respectively. In this work, we have demonstrated that the non-toxic LPS from Rhodobacter capsulatus PG blocks the synthesis of pro-inflammatory cytokines during the activation of blood cells by Streptococcus pyogenes LTA through binding to the CD14 receptor, resulting in the signal transduction to TLR2/TLR6 being blocked.

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Search for the effective approaches to treat acute inflammation caused by combination of allergens and infectious agents is an important task for public health worldwide. House dust mites Dermatophagoides pteronyssinus are the source of allergens of the Der p groups and of microbial compounds, in particular, lipopolysaccharides (LPS). LPS and Der p 2 induce secretion of pro-inflammatory cytokines via activation of kinases p38 MAPK, MEK1/2, and PI3K.

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We report a novel family of natural lipoglycopeptides produced by Streptomyces sp. INA-Ac-5812. Two major components of the mixture, named gausemycins A and B, were isolated, and their structures were elucidated.

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Systemic inflammation plays a crucial role in formation of various pathological conditions, including sepsis, burns, and traumas. The main effector cells participating in progression of systemic inflammation response and sepsis are monocytes, which regulate both innate and acquired immunity via phagocytosis, synthesis of cytokines and chemokines, antigen presentation, and lymphocyte activation. Thus, the monocytes are considered as a link between innate and acquired immunity.

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Article Synopsis
  • Previous studies focused on farming ants and their use of antifungal microbes, but this research investigates the symbiosis between carpenter ants and actinobacteria.
  • * Antimycin A complex, produced by the isolated actinobacteria strain A10, was found to have significant antimicrobial and cytotoxic properties.
  • * The study suggests that strain A10 may help protect carpenter ants from infections, although the exact nature of this relationship needs further exploration.*
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Lipopolysaccharides (LPSs or endotoxins) from Gram-negative bacteria represent pathogen-associated molecular patterns (PAMPs) that are recognized by CD14 and Toll-like receptor 4 (TLR4). Lipopolysaccharides prime polymorphonuclear leukocytes (PMNs) for substantial production of reactive oxygen species (ROS) during its response to secondary stimuli such as chemoattractants or pathogens. The excessive ROS production can damage surrounding host tissues, thereby amplifying the inflammatory reaction caused by pathogens.

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Lipopolysaccharides (LPSs) induce a wide spectrum of functional activities after interaction with blood cells. Effect of structure of toxic LPS from S- and Re-chemotypes of E. coli and/or non-toxic LPS of Rhodobacter capsulatus PG (R.

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The development of a specific inflammation in mice that had been infected by two influenza virus strains, A/chicken/Kurgan/5/2005 (H5N1) and A/Hamburg/2009 MA (H1N1), was studied. We investigated the effect of a non-toxic lipopolysaccharide from Rhodobacter capsulatus PG on the survival and body weight of the mice, production of IgG antibodies, and the induction of pro- and anti-inflammatory cytokines in blood serum. The administration of the R.

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Lipopolysaccharides (LPS) from Gram-negative bacteria prime human polymorphonuclear neutrophils (PMNs) via multicomponent receptor cluster including CD14 and MD-2·TLR4 for the enhanced release of reactive oxygen species (ROS) were triggered by bacterial derived peptide -formyl-methionyl-leucyl-phenylalanine (fMLP). In this study, we investigated the impact of CD14 on LPS-induced priming of human PMNs for fMLP-triggered ROS generation (respiratory or oxidative) burst. Monoclonal antibodies against human CD14 (mAbs) as well as isotype-matched IgG2a did not influence significantly fMLP-triggered ROS production from LPS-unprimed PMNs.

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Purpose: House dust mites Dermatophagoides pteronyssinus are the main source of major inhalatory allergens inducing inflammatory response. Mite extract contain both allergenic proteins and lipopolysaccharides (LPS). The main allergenic protein, Der p 2, is a functional homolog of sMD-2, a protein providing blood cell response on LPS.

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The capacities of relatively nontoxic lipopolysaccharide (LPS) from Rhodobacter capsulatus PG and highly potent LPS from Salmonella enterica serovar Typhimurium to evoke proinflammatory cytokine production have been compared in vivo. Intravenous administration of S. enterica LPS at a relatively low dose (1 mg/kg body weight) led to upregulation of TNF-α, IL-6, and IFN-γ production by non-sensitized CD-1 mice.

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The study of an archived sample of crystallomycin complex using HPLC, ESI HRMS, and 2D NMR showed that two major components of the antibiotic, compounds and , are lipopeptides having the same peptide core, Asp1-cyclo(Dab2-Pip3-MeAsp4-Asp5-Gly6-Asp7-Gly8-Dab9-Val10-Pro11-), -acylated either with Δ-iso-tetradecenoyl or Δ-anteiso-pentadecenoyl that are identical to aspartocins C and B, respectively. According to the 2D NMR study, compound in DMSO solution exists as a mixture of four conformers. The producing strain was identified as .

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We studied the effects of Human TruStain FcX buffer (Fcγ receptor blocking solution) in experiments on evaluation of TLR4 level with labeled monoclonal antibodies, intracellular immunofluorescent staining of NF-κB p50, and TNF-α synthesis on human isolated monocytes and whole blood cells. The influence of the blocking buffer on the measured parameters should be taken into account and appropriateness of its use in experiments on isolated cells and whole blood should be considered.

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Detection of aminoglycoside antibiotics by MS or HPLC is complicated, because a) carbohydrate molecules have low ionization ability in comparison with other organic molecules (particularly in MALDI-MS), and b) the lack of aromatics and/or amide bonds in the molecules makes common HPLC UV-detectors useless. Here, we report on the application of a previously developed method for amine derivatization with tris(2,6- dimethoxyphenyl)carbenium ion to selective modification of aminoglycoside antibiotics. Only amino groups bound to primary carbons get modified.

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Molecular beacons carrying JOE dye (4',5'-dichloro-2',7'-dimethoxy-6-carboxyfluorescein) on a rigid or flexible linker and one or two BHQ1 quenchers have been prepared and tested in real-time PCR using Fusarium avenaceum elongation factor 1α DNA template. The probes were different in their structures (loop size and stem length), linkers for dye attachment (6-aminohexanol or trans-4-aminocyclohexanol), quencher composition (single and double BHQ1) to elucidate the influence of all these features. Fluorogenic properties of the probes were studied and compared to those of FAM (fluorescein)-based probes.

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The dynamics of antagonistic potency of lipopolysaccharide (LPS) isolated from Rhodobacter capsulatus PG on the synthesis of proinflammatory (TNF-α, IL-1β, IL-8, IL-6, IFN-γ) and antiinflammatory (IL-10, IL-1Ra) cytokines induced by highly stimulatory endotoxins from Escherichia coli or Salmonella enterica have been studied. Using human whole blood, we have shown that R. capsulatus PG LPS inhibited most pronouncedly the endotoxin-induced synthesis of TNF-α, IL-1β, IL-8, and IL-6 during the first 6 h after endotoxin challenge.

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The primary objective of this study was to determine the role of β2 integrin α-subunit (CD11b) in the mechanism of human polymorphonuclear leukocyte (PML) priming by S or Re endotoxin glycoforms from Escherichia coli for fMLP-induced respiratory burst. Similar priming activity of S and Re endotoxin glycoforms for fMLP-induced reactive oxygen species (ROS) generation from primed PML was found. Anti-CD11b antibodies (clone ICRF 44) as well as isotype-matched immunoglobulin G1 (clone MOPC-21) do not influence the fMLP-induced ROS generation from unprimed PML.

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Convenient preparation of fluorogenic hairpin DNA probes (molecular beacons) carrying a pair of FAM fluorophores (located close to 5'-terminus of the probe) or a pair of BHQ1 quenchers on 3'-terminus (with (BHQ1)2 or BHQ1-BHQ1 composition) is reported. These probes were used for the first time in a real-time PCR assay and showed considerable improvements in fluorogenic properties (the total fluorescence increase or signal-to-background ratio) in assay conditions vs. conventional one-FAM-one-BHQ1 molecular beacon probes as well as vs.

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By using the fMLP-induced respiratory burst approach, the involvement of Toll-like receptor 4 (TLR4) in human neutrophil priming by S- or Re-glycoforms of endotoxin from Escherichia coli has been elucidated. The priming effect of Re-glycoform is more pronounced than that of the S-glycoform. Unexpectedly, fMLP-triggered generation of reactive oxygen species (ROS) by endotoxin primed neutrophils was amplified by preincubation of the cells with anti-TLR4 (HTA125) antibodies or with isotype-matched immunoglobulin IgG2a.

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This unit describes the preparation of 5- and 6-carboxy derivatives of the xanthene fluorescent dyes fluorescein (FAM), 4',5'-dichloro-2',7'-dimethoxy-fluorescein (JOE), and tetramethylrhodamine (TAMRA) as individual isomers, and their conversion to non-nucleoside phosphoramidite reagents suitable for oligonucleotide labeling. The use of a cyclohexylcarbonyl (Chc) protecting group for blocking of phenolic hydroxyls facilitates the chromatographic separation of isomers of carboxy-FAM and carboxy-JOE as pentafluorophenyl esters. Acylation of 3-dimethylaminophenol with 1,2,4-benzenetricarboxylic anhydride gave a mixture of 4-dimethylamino-2-hydroxy-2',4'(5')-dicarboxybenzophenones, easily separable into individual compounds upon fractional crystallization.

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Interrelations between peculiarities of psychological profile of patients of senior age groups (according to Cattel), level of stress hormones in blood and background pathology of cardiovascular system were studied. Levels of catecholamine and corticosteroids in dynamics, rate of magnesium in erythrocytes and calcium in plaques of coronary arteries as well as fats, Holter ECG, daily profiles of blood pressure, vasomotor function of endothelium and microcirculation were analysed. It is established that stress hormones indirectly determine original form of stress reaction depending on patients' psychological profile.

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A typical TaqMan™ real-time PCR probe contains a 5'-fluorescent dye and a 3'-quencher. In the course of the amplification, the probe is degraded starting from the 5'-end, thus releasing fluorescent dye. Some fluorophores (including fluorescein) are known to be prone to self-quenching when located near each other.

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