Peculiarities of functional activity of circulating phagocytes in patients with different forms of drug-resistant pulmonary tuberculosis

Functional activity of circulating phagocytes (macrophages and neutrophils — Ns) was studied in 30 patients with infiltrative and 30 patients with fibro-cavernous pulmonary tuberculosis (IPT and FCPT, respectively), characterized by similar biological properties of mycobacterium tuberculosis (MTB), dissemination of the process, and manifestations of intoxication. Differences of the functional activity of both types of cells depending on the PT form were found: a more significant increase in the oxygen-depending activity in FCPT while bactericide potential estimated with the zymosan induced NST-test was more pronounced in IPT patients. These data correlate with the blood levels of neopterin and elastase, the markers of the mononuclear and neutrophil activity, respectively. Involvement of adenosine deaminase (ADA) and neopterin in realization of intracellular oxygen-dependent processes was demonstrated. Results of the multivariate analysis of the whole set of the studied phagocyte parameters, reflecting their different roles in this pathological process demonstrated a prevailing role of mononuclears in newly diagnosed IPT and neutrophils in the chronic progressive process.     

Cytokine-stimulating activity of lipopolysaccharide of gram-negative bacteria and its role in antitumor immunity

The review deals with the discussion of different mechanisms of the antitumor action of lipopolysaccharides (LPS), including the induction of endogenous cell mediators, the development of inflammatory and immune response and systemic metabolic changes. The complex action of these factors on the levels of cells, tissues, organs and the whole body led, in some cases, to the suppression or hemorrhagic necrosis of the tumor. These cases were regarded as analogous to the development of the septic syndrome when a cascade of reactions leading to the resorption of tumors was initiated and to chronic inflammation resulting, on the contrary, in the formation of pretumor status. The data on the role of cytokines in carcinogenesis are presented and the possible causes of established contradictions are discussed. The prospects of using LPS in the therapy of oncological diseases are discussed.     

Highly pathogenic avian influenza virus inducing influenza pneumonia in humans

The human disease caused by avian influenza virus in South Asia is a typical example of emerging infection resulting from transmission of a known causative agent to a new host. The first cases with a comparatively high level of lethality rates among patients were registered in 1997 and 1999. The situation is a special phenomenon in epidemiology which requires deep evolutionary and ecological analysis, as well as theoretical interpretation. With the example of avian influenza virus in Western Europe and South Asia in 2003-2004 the practical expediency of modern concepts "foci versus epidemics" and "eradication versus vaccination" is now evident.     

Influence of plasmid pR50 controlling bacterial protease activity on Salmonella experimental infection

The comparative analysis of the infectious process and immunological parameters in (CBA x C57BL/6)F1 mice infected with S. typhimurium isogenic strains differing by the presence of plasmid pR50 determining protease activity, was carried out. A growth in the expression level of antilactoferrin, anticomplementary and anti-immunoglobulin activity in bacteria isolated from the spleen in the course of the infectious process was detected. In mice infected with S. typhimurium having plasmid pR50, in contrast to nonplasmid recipients, a higher level of contamination of organs, the suppression of spontaneous, stimulated production of interferon-gamma and the bactericidal properties of peritoneal macrophages were noted. The data obtained in this investigation suggested that the acquisition of R-plasmid of 50 MD, controlling protease activity and multiple medicinal resistance, contributed to the persistence of intracellular bacteria.     

Identification of cysteinylation of a free cysteine in the Fab region of a recombinant monoclonal IgG1 antibody using Lys-C limited proteolysis coupled with LC/MS analysis

MAB007, an IgG1 monoclonal antibody, is unique because of the presence of a free cysteine residue in the Fab region at position 104 on the heavy chain in the CDR3 region. Mass spectrometric analysis of intact MAB007 showed multiple peaks varying in mass by 120-140 Da that cannot be fully attributed to glycosylation isoforms typically present in IgG molecules. Limited proteolysis of MAB007 with Lys-C led to a single cleavage at the C-terminus of a lysine residue in the hinge region of the heavy chain at position 222, generating free Fab and Fc fragments. Reversed-phase liquid chromatography/mass spectrometry analysis of the Fab and Fc fragments revealed several modifications. The Fab fraction showed cysteinylation of a free cysteine in the CDR3 region resulting in a mass shift of 119 Da. Using limited proteolysis, we also identified modifications resulting in a mass increase of 127 Da in the Fc region, corresponding to C-terminal lysine variants in the heavy chain. Other modifications, such as oxidation (+16 Da) and succinimide formation (-17 Da), were also detected in the Fab fragment. The cysteinylation observed after limited proteolysis was confirmed by peptide mapping coupled with tandem mass spectrometry analysis.     

In vitro stoichiometry of complexes between the soluble RANK ligand and the monoclonal antibody denosumab

The in vitro binding stoichiometry of denosumab, an IgG2 fully human monoclonal therapeutic antibody, to RANK ligand was determined by multiple complementary size separation techniques with mass measuring detectors, including two solution-based techniques (size-exclusion chromatography with static light scattering detection and sedimentation velocity analytical ultracentrifugation) and a gas-phase analysis by electrospray ionization time-of-flight mass spectrometry from aqueous nondenaturing solutions. The stoichiometry was determined under defined conditions ranging from small excess RANK ligand to large excess denosumab (up to 40:1). High concentrations of denosumab relative to RANK ligand were studied because of their physiological relevance; a large excess of denosumab is anticipated in circulation for extended periods relative to much lower concentrations of free soluble RANKL. The studies revealed that an assembly including 3 denosumab antibody molecules bound to 2 RANKL trimers (3D2R) is the most stable complex in DPBS at 37 °C. This differs from the 1:1 binding stoichiometry reported for RANKL and osteoprotegerin (OPG), a soluble homodimeric decoy receptor which binds RANKL with high affinity. Denosumab and RANKL also formed smaller assemblies including 1 denosumab and 2 RANKL trimer molecules (1D2R) under conditions of excess RANKL, 3 denosumab molecules and 1 RANKL trimer (3D1R) under conditions of excess denosumab, and larger assemblies, but these intermediate species were only present at lower temperatures (4 °C), shortly after mixing denosumab and RANKL, and converted over time to the more stable 3D2R assembly.     

Crowding-effect and attention

We studied the influence of additional objects on recognition of the test visual objects. The test objects were stylized low-contrast letters having size 1.1, 2.1 or 4.3 ang. deg. The additional objects after 30 ms were followed by the test objects which were presented in the middle of the screen. The additional objects were digits 1-9 having size 1.3 ang. deg. The digits were presented at various distances from the centre of the screen. The observers' task was to identify both the test objects and the digits. Recognition of the test objects deteriorated when the digits were at small distances to the tests (crowding-effect). Recognition of digits deteriorated with the increasing distances from the centre of the screen; the effect was more pronounced when the tests were large. The contribution of laterals masking and attention into crowding-effect is discussed.