Rhodobacter capsulatus PG Lipopolysaccharide Blocks the Effects of a Lipoteichoic Acid, a Toll-Like Receptor 2 Agonist.

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. The LPS from Rhodobacter capsulatus PG can be considered a prototype for developing preparations to protect blood cells against the LTA of gram-positive bacteria.

The Effect of a Lipopolysaccharide from Rhodobacter capsulatus PG on Inflammation Caused by Various Influenza Strains.

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. capsulatus PG lipopolysaccharide was shown to induce interferon-ß synthesis, both in healthy and influenza A virus-infected mice, and to promote production of antiviral antibodies in the blood of the influenza-infected animals.

Artifacts Arising from Using Leukocytic Fc Receptor Blocking Buffer.

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.

Dynamics of Antagonistic Potency of Rhodobacter capsulatus PG Lipopolysaccharide against Endotoxin-Induced Effects.

The dynamics of antagonistic potency of lipopolysaccharide (LPS) isolated from Rhodobacter capsulatus PG on the synthesis of proinflammatory (TNF-α, IL-1ß, 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-1ß, IL-8, and IL-6 during the first 6 h after endotoxin challenge. Similarly, the endotoxin-induced release of IFN-γ was abolished by R. capsulatus PG LPS as well (24 h). In contrast to the above-mentioned cytokines, the relatively weak antagonistic activity of R. capsulatus PG LPS against endotoxin-triggered production of IL-6 and IL-8 was revealed. Since R. capsulatus PG LPS displays more potent antagonistic activity against deleterious effects of S. enterica LPS than those of E. coli LPS in the cases of such cytokines as IL-1ß (6 and 24 h), IL-6 and IL-8 (4 h), we conclude that the effectiveness of protective action of antagonist is mostly determined by the primary lipid A structure of the employed agonist.

Role of CD11b/CD18 in priming of human leukocytes by endotoxin glycoforms from Escherichia coli.

The primary objective of this study was to determine the role of ß2 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. Antibodies against CD11b do not change fMLP-induced ROS generation from endotoxin-primed PML as well. The involvement of different isoforms of Fcγ receptors in fMLP-induced ROS generation from activated PML is proposed.

[Calf blood hemodializate reduces neurotoxic effect of hydrogen peroxide on human neuroblastoma cells].

OBJECTIVE: Our aim was to study the effect of calf blood gemodializat on apoptosis and intracellular signaling pathways of neuroblastoma cells SK-N-SH human. METHODS: Apoptosis was recorded by fluorescent microscopy using Hoechst 33342. Necrosis cells was monitored by propidium iodide. The fluorescence of the cells was recorded on a fluorescence inverted microscope Keyence BZ8100 (Japan). Formation of reactive oxygen species (ROS) in the cells of SK-N-SH was determined using nitroblue tetrazolium by absorbance at 620 nm on a plate reader "Uniplan". RESULTS: When adding hydrogen peroxide to the background of the calf blood gemodializat been decreasing apoptosis of these cells with 43 to 17% relative to apoptosis in the presence of a hydrogen peroxide. Under these conditions, the calf blood gemodializat significantly reduced ROS formation in human neuroblastoma cells SK-N-SH by the action of hydrogen peroxide. In these cells, we investigated the influence of calf blood gemodializat on apoptosis and intracellular signaling pathway involving mitogen-activated protein kinase (p38MAPK), extracellular regulatory kinase (ERK), phosphatidylinositol 3-kinase (PI-3K) and-Jun-N-terminal kinase (JNK) using their selective inhibitors. CONCLUSION: It was shown that the mechanism of the protective effect of calf blood gemodializat against peroxide-induced apoptosis in SK-N-SH dominant role is played by p38 MAPK and PI-3K.

[New approaches in the regulation of blood phagocytes and reduction in the formation of oxygen radicals in patients with heart failure].

AIM: The purpose was to study the effect of actovegin on the formation of reactive oxygen species by blood phagocytes of patients with heart failure and on SK-N-SH neuron necrosis. MATERIALS AND METHODS: The generation of superoxide anion (O2-*) were recorded on whole blood samples (50-100 µl). Change lucigenin-dependent hemiluminescence determined on a hemi-luminometer "Biotoks-7". As a stimulator of the phagocyte. phorbol ester (PMA, 1 µm) was used. Necrosis of neurons induced by hydrogen peroxide was determined by fluorescence of propidium iodit. RESULTS: Blood phagocytes of heart failure patients are initially pre-activated (primed). These cells spontaneous generated oxygen radicals. Actovegin dosa-dependent decreased radicals level and radical induced by PMA (1 µm). After PMA maximal inhibitory effect of actovegin observed in doses higher than 2-3 mg/ml. The impact of actovegin on the viability of human SK-N-SH neurons in the presence hydrogen peroxide (100 µm) was studied in vitro. Under these conditions hydrogen peroxide triggered radical-dependent neurons necrosis Actovegin dosa-dependent decreased of neuron death. CONCLUSION: Actovegin inhibits spontaneous and induced formation of reactive oxygen species generated by blood phagocytes of patients with heart failure. Actovegin suppressed necrosis of human SK-N-SH neuroblastoma cells caused by hydrogen peroxide. It is assumed that actovegin protects_cells of arious organs and tissues, including blood cells and neurons that die as a result of ischemia and inflammation by reducing levels of react.ive-oxygenspecies.

[The venture financing of scientifically-innovative projects: teaching experience in medical high school].

The authors presented an original material, devoted to first experience of teaching of theoretical bases of venture financing of scientifically-innovative projects in medical high school. The results and conclusions were based on data of the questionnaire performed by the authors. More than 90% of young scientist physicians recognized actuality of this problem for realization of their research work results into practice. Thus, experience of teaching of theoretical bases of venture financing of scientifically-innovative projects in medical high school proves reasonability of further development and inclusion the module "The venture financing of scientifically-innovative projects in biomedicine" in the training plan.

[An innovational model of elite tuition of students motivated towards scientific research activity].

Sechenov Moscow Medical Academy has accumulated almost 20-year positive experience in the work of the faculty training research and educational staff. The functioning of such a faculty perfects the original elite system for training research and educational staff at the undergraduate stage of medical education. Search for and introduction of innovational technologies to the educational process to train a new generation of researchers for biomedical science and universities is constantly carried out. The system favors the providence of medical schools, scientific and practical medical institutions with qualified staff, as well as the integration of Russian education into the European system of medical education.

[High-intensity focused ultrasound ablation, a new method for the minimally invasive treatment of hepatic tumours].

High-intensity focused ultrasound (HIFU) is a new totally noninvasive treatment of liver neoplasms allowing for selective ablation of the neoplastic tissue. It was first described in the 1920s but attracted more attention only in the 1990s when the possibility of high-quality three-dimensional monitoring substantially improved efficiency of diagnostic ultrasound scanning and magnetic resonance imaging. Numerous experimental and clinical studies demonstrated the safety of the method and its applicability to the treatment of oncological patients. This review highlightens the principles of HIFU, describes the equipment for HIFU and the current state of investigations with the use of this technique with special reference to hepatic tumours. Prospects for the further development of HIFU are outlined.

[Pathogenetic aspects of intoxication syndrome in the clinical picture of infectious diseases].

Pathogenetic mechanisms of intoxication syndrome in patients with infectious diseases are considered in the context of current general pathologic concepts. All major components of pathogenesis are discussed in terms of the authors' original observations and literature data. Bacterial endo- and exotoxines are believed to be the main inductors of intoxication. Results of original studies suggest an important contribution of Shiga toxins to specific clinical manifestations of infectious diseases. A novel interpretation of the role of intoxication syndrome in the development of infectious diseases is proposed.