[Live attenuated and inactivated influenza vaccines: data from direct comparative studies].

Comparative evaluation of live attenuated and inactivated influenza vaccines based on data from direct comparative studies is necessary for ensuring the most effective and safe vaccination against influenza. Analysis of direct comparative preclinical and clinical studies of inactivated and live cold-adapted (ca) influenza vaccines showed that published data are inconsistent and limited for some population groups. Live ca vaccines may be promising as an alternative or addition to inactivated vaccines especially for mass vaccination against influenza in children as well as in the elderly when combined with inactivated vaccines. Further studies of inactivated and live ca influenza vaccines in direct comparative studies that control the administration route and vaccine strain production as well as development and confirmation of objective criteria of live attenuated influenza vaccine effectiveness evaluation are necessary.

[Cells of endothelial lineage (or endothelial-like cells) as possible progenitor cells of sarcomas induced by implanted foreign body].

This study is dedicated to the problem of the origin of progenitor cells of sarcomas induced by implantation of a foreign body (polyvinilchloride plates) to mice. It is known that such cells are found among the cells of the monolayer covering the surface of implanted plate without any signs of tumor growth in 6 and more months after implantation. We studied the existence of endothelial features of mesenchymal type cells that had been grown by culturing the cells from the implanted plate surface in 9 and 14 months after implantation. We have shown that these cells are really the precursors of FB sarcomas thou they had different tumor potential depending on the period since implantation moment. We studied the behavior of these pretumor cells in 2D (on plastic) and 3D (on matrigel) cultures. We have found that in the case of a dense monolayer on plastic such cells show growth of endothelial type (cobblestone). When sown on matrigel they are organized in more or less typical capillary-like structures that subsequently form secondary branching vascular-like structures named "secondary sprouting". Such behavior is also characteristic for endothelial cells. This observations allow us to postulate the possibility of endothelial origin of FB sarcomas.

[Increasing the immunogenicity of inactivated chitosan adjuvanted vaccine from A/California/7/09 (H1N1) strain and analyzing the antigenic specificity of this influenza virus strain].

Addition of chitosan as an adjuvant to subunit vaccine from the swine origin influenza virus A/California/7/09 (H1N1) increases vaccine immunogenicity by 8-16 times and significantly enhances its protective potency. Single immunization with chitosan adjuvanted vaccine induced similar antibody titers as two immunizations with unadjuvanted vaccine. Chitosan stabilized the immunogenicity of subunit vaccine when stored at 4 degrees C. The antigenic specificity of the A/California/7/09 (H1N1) virus strain did not resemble substantially that of the human influenza strains A/Brisbane/59/07 (H1N1) and A/Solomon Isles/3/06 (H1N1), which are among the 2008/2009 and 2007/2008 seasonal influenza vaccines, respectively, as well as that of the human influenza H1N1 virus strains that circulated about 30 years ago.

[Epidemiologic and economic effectiveness of school closure during influenza epidemics and pandemics].

Epidemiologic and economic effectiveness of school closure during influenza epidemics and pandemics is discussed. Optimal effect of school closure is observed when this measure is taken at the start of the epidemic or pandemic and for a sufficiently long time. School closure during high morbidity among schoolchildren, in the middle (at the peak) and by the end of epidemic or pandemic does not influence significantly the spread of influenza or morbidity. Significant economic losses and other negative consequences of school closure are noted. School closure may be the most appropriate during the emergence of influenza pandemic when the pandemic vaccine is not yet available, however timely mass immunization of schoolchildren against influenza may be a more appropriate measure than school closure for the reduction of influenza morbidity and spread during seasonal influenza epidemics.

[Enhancing the immunogenicity of inactivated polio vaccines with chitosan used as an adjuvant].

Addition of chitosan to inactivated trivalent polio vaccine or inactivated preparations of attenuated poliomyelitis viruses (Sabin strains) significantly increases immunogenicity of these inactivated poliomyelitis virus preparations. High neutralizing antibody titers are detected after two immunizations of mice and a single immunization of rats, as well as when the antigen dose was reduced by 4 times. Addition of chitosan as an adjuvant significantly induces cellular immunity.

[Influenza vaccines adjuvants--contemporary state].

Data on development and study of adjuvants for influenza vaccines against avian and seasonal influenza are presented. Requirements to perspective adjuvants, their main groups (mineral salts of aluminium, squalene derivatives, polyglycosides, and immunomodulators) as well as experimental adjuvants are reviewed. Analysis of results of several clinical trials of adjuvanted vaccines against avian influenza is presented. On the basis of published data analysis conclusion about good perspective of influenza vaccines with new adjuvants was made.

[Comparative study of avian influenza virus propagation in the cell culture and chick embryos].

Comparative reproduction studies of 7 avian influenza virus strains (H5N1, H5N2, H3N2, H4N6, H7N7) in Vero and MDCK cell lines have indicated that the MDCK cell line is an optimal substrate for all study strains. The maximum viral output depends on trypsin concentrations and infection doses, which can differ for individual viral strains. The use of the optimal parameters of avian influenza virus replication in the MDCK cell lines yields virus titers comparable with virus reproduction in the chick embryos. The reproductive studies of the same avian influenza virus strains in chick embryos have shown that the maximum virus multiplication is seen when observing the optimum incubation time for infected embryos, which may be dissimilar in different strains. A considerable increase in hemagglutinin output can be achieved on adding trypsin to the infected chick embryos.

[Chitosan as an adjuvant for inactivated vaccines against avian influenza viruses].

AIM: To study chitozan as an adjuvant for inactivated vaccines against A/H5 influenza viruses. MATERIALS AND METHODS: Avian A/H5 influenza viruses were grown on chicken embryos or on MDCK cell line; viruses-containing fluid was inactivated with formalin. Mice were vaccinated intramuscularly with inactivated avian influenza virus mixed with chitozan and then levels of hemagglutination-inhibiting and neutralizing antibodies as well as protective efficacy against both homologous and drifted strains of avian influenza viruses A/H5 were measured. RESULTS: Addition of chitozan to inactivated preparations of A/H5 avian influenza viruses for immunization of mice significantly increased levels of hemagglutination-inhibiting and neutralizing antibodies to both homologous and drifted variants of A/H5 influenza viruses, including those containing neuraminidase from other subtype as well as strains isolated 10 - 20 years earlier than virus used for vaccination. Chitozan significantly improved protective efficacy of inactivated avian influenza vaccines against infection with both homologous and drifted variant of the virus. Vaccination with inactivated avian influenza viruses A/H5 and chitozan induced high levels of antibodies even after single immunization as well as after administration of 8-fold reduced dose of preparation. CONCLUSION: Chitozan is a perspective adjuvant for inactivated vaccines against avian influenza viruses, which could significantly improve immune response and protective efficacy against both homologous and drifted variants of avian influenza viruses A/H5.

[Mechanisms of social behavior of the vertebrate tissue cells: cultural models].

Morphogenetic interactions between cells in the organism are largely reproduced in the cell cultures of various types, in particular, in that of the epitheliocytes and fibroblasts. The cultured cells interact by means of receptors and ligands, which activate intracellular signal systems. Three microenvironment components (liquid medium, extracellular matrix, and intercellular contacts) play the role of such ligands. The ligands of liquid medium include hormones, growth factors, apoptosis factors and other molecules. Specific structures strongly tied with the cytoskeleton (with the actin one, first of all) use to appear during contacts with other cells and with the cellular base. Encounter between two fibroblasts or between two epitheliocytes causes local inhibiting of pseudopodial activity (so called contact paralysis). Regeneration of the connective tissue and the epithelial layer, as well as epithelial-mesenchimal transformation, is successfully reproduced in the cell culture. Incomplete epithelial-mesenchimal transformation seems to serve as a base for morphogenesis of various glands and lungs, as well as of angiogenesis.

[Avian influenza vaccines].

The review gives data on the designing of avian influenza vaccines and the preparation of human safe vaccine strains from the highly virulent strains of these viruses. It considers activated and live vaccines, promising adjuvants for vaccines, as well as recombinant, virus-vector, and DNA vaccines and virus-like particles. The results of a number of clinical trials of avian influenza vaccines are examined. Analysis of the data published leads to the conclusion that cell culture-based whole-virion vaccines with adjuvants are promising in combating avian influenza.

[Distribution of actin isoforms in normal, dysplastic, and tumorous human breast cells].

The distribution of beta- and gamma-cytoplasmic actins was compared in the normal cells and dysplastic malignant breast epithelial cells. In the normal luminal epithelium, beta- and gamma-cytoplasmic actins were located in different cell compartments: gamma-actin was more expressed in the apical parts of epithelial cells while beta-actin was in their basolateral domain. Polarized distribution of actinic isoforms was partially preserved in the papillomas and fibroadenomas; a more pronounced coexpression of isoforms was detected in the dysplastic proliferates. In ductal and lobular in situ carcinoma cells, gamma-actin filamentous structures were absent while the gamma-cytoplasmic actin network throughout the cytoplasm was increased. It is generally accepted that the enhanced motility of cancer cells as to the nonmalignant situation is crucial in the process of cancer invasion. The authors' findings suggest that specific monoclonal antibodies to beta- and gamma-cytoplasmic actins may be used as supplementary markers that can differentiate benign and malignant breast neoplasms.

[Mechanisms of the invasion of normal and malignant cells].

Different examples of invasion in normal ontogenesis and during the growth of malignant genetically altered cells are discussed. The invasive migration of single epithelial cells or cell groups may be regarded as pathological variants depending on complete or partial epithelio-mesenchymal transformation. A very special new type of epithelial cell dissemination from the monolayer was observed in our experiments with epithelial cells hyperexpressing transfected RhoA gene. In these experiments, mitotic cells were squeezed out of the contracted monolayer into a fluid medium, floated passively in this medium, and settled at the substrate forming new islands. It is important to find whether this type of dissemination not associated with active cell movements can take place in tumors in vivo.

[Reorganization of cytoskeleton as basis for morphogenesis].

A brief review of the cytoskeleton dynamic structure in cells of two types: fibroblasts and epitheliocytes. Differences have been described between the functions of y-actin filaments and beta-actomyosin bundles. Tubulogenesis and angiogenesis have been considered as consequences of partial epitheliomesenchymal transformation and neoplastic transformation as a consequence of gamma-actomyosin bundles disturbance.

[Expression of E-cadherine as a differential diagnostic fest for lobular infiltrative breast cancers].

An immunomorphological study of 30 breast carcinomas was conducted. In accordance with the histological characteristics they had been previously diagnosed as lobular infiltrative carcinomas (LIC). We have studied E-cadherin cell-cell adhesion molecules and also epithelial markers and basement membranes. We have analyzed the cryostate and paraffin sections of in situ structures, invasion components and metastases. E-cadherin staining was negative, positive or mixed. The E-cadherin negative group consisted of 17 carcinomas of classic LIC accompanied with dyshesive invasion. The E-cadherin positive group consisted of 6 carcinomas. According to our results this diagnosis was changed to ductal infiltrative carcinoma. The E-cadherin mixed group consisted of 7 special type carcinomas with double lobular-ductal differentiation, which had in situ structures of negative or positive cells. In these cases in situ structures consisting of both E-cadherin negative and positive parts were also observed. It is shown that E-cadherin expression can be used in doubtful cases in order to differentiate between the lobular and ductal forms of breast carcinoma.

[Stimulation of grafting of a minimal number of tumor cells after their transplantation into the subcutaneous "air pouch"]. / Stimuliatsiia privivaemosti minimal'nogo kolichestva opukholevykh kletok pri transplantatsii v podkozhnyi "vozdushnyi meshok".

Transplantation of the minimal number of cultivated cells of sarcoma line 84 into CBA mice gave higher percentage of tumours when these cells were inoculated into the subcutaneous "air pouch" in comparison with the standard subcutaneous unoculation.

[Sensitivity of the proliferation of normal and tumor cells to cytochalasin D]. / Chuvstvitel'nost' proliferatsii normal'nykh i opukholevykh kletok k tsitokhalazinu D.

The effect of cytochalasin D, which is known to disrupt specifically actin cytoskeleton, on DNA replication was studied. The incubation of cultured mouse embryonic fibroblasts (MEF), cells of Balb/3T3 line and cells of minimally transformed clones 12 MC and 6 st/T CAK-7 line with cytochalasin D leads to inhibition of DNA synthesis. A complete inhibition of labeled index in MEF culture was observed after an 8 day incubation in cytochalasin D. Part of cells of clones 12 MC and 6 st/T were insensitive to cytochalasin D and continued to enter to S-phase even after a 10 day incubation. The transfer of cells into a fresh medium leads to a rapid restoration of DNA synthesis. Strongly transformed L cells were almost insensitive to cytochalasin D. Thus, the reorganization of actin cytoskeleton caused by cytochalasin D can inhibit the cycle of normal and minimally transformed cells. In the course of neoplastic progression, in the transformed cells there is a loss of dependence of cell proliferation on microfilament system.

[Cytoskeletal changes in mouse embryonic fibroblasts exposed to colcemid. Electron microscopic research on platinum replicas]. / Izmeneniia tsitoskeleta myshinykh émbrional'nykh fibroblastov pod deistviem koltsemida. Elektronno-mikroskopicheskoe issledovanie platinovykh replik.

Cytoskeletons of colcemid-treated mouse embryo fibroblasts were studied using platinum replica technique. In the control cells, cytoskeletal components were oriented along direction of cell polarization. Structure of the control cytoskeleton changed regularly from the cell active edge to its centre forming several zones. Distribution of microtubules by colcemid led to significant changes in the organization of actin cytoskeleton. Both orientation and zonal differentiation of cytoskeleton disappeared in colcemid-treated fibroblasts. Changes in the fine structure of microfilament sheath were most prominent. Control sheath was composed of stretched tightly packed microfilaments. Colcemid treatment transformed it into fine microfilament meshwork, normally characteristic only for ruffle zone. Alterations of the fine structure of focal contacts and ruffles were also observed in treated cells. The role of microtubules in the organization of intracellular tensions and in the distribution of sites of actin polymerization is discussed.

[The effect of the depolymerization and disintegration of the microtubular system on the cytoskeleton of untransformed and transformed cells]. / Vliianie depolimerizatsii i dezintegratsii sistemy mikrotrubochek na tsitoskelet netransformirovannykh i transformirovannykh kletok.

How important are the changes of microtubule control for the realization of actin cortex changes during neoplastic transformation? To answer this question we studied the actin cytoskeleton and intermediate filaments condition after colcemid destruction or taxol disintegration of microtubule system in non-transformed cells BALB/c 3T3 and in the same cells transformed by Ha-ras gene. We have come to a conclusion that the differences between non-transformed and transformed cells in the actin cytoskeleton organization remain the same after specific inhibitor action on the microtubules; after the microtubules are destroyed the differences between the two cell types appear in the intermediate filament organization; there are reasons to assume that changes in the actin cortex structure may play the central role in morphological transformation expression.

[Redistribution of concanavalin A receptors on the thrombocyte surface]. / Pereraspredelenie retseptorov k konkanavalinu A na poverkhnisti trombotsitov.

Using the indirect immunofluorescence method, it has been shown for the first time that concanavalin A receptors can undergo a redistribution over the surface of platelets spread on the substrate. The distribution of receptors in the intact cells is diffuse and random. Con A receptors, cross-linked by their ligand, are removed from the surface of the lamellar cytoplasm of living substrate-spread platelets. These receptors move into the central part of cell surface. This phenomenon is similar to capping or clearing of lamellar cytoplasm of big nucleated cells. Cytochalasin B (10 mcg/ml) does not prevent the formation of patches of receptors but inhibits the clearing of the lamellar cytoplasm of spread platelets. This result suggests that microfilaments may be involved in the redistribution of receptors.

[Distribution of fibronectin on the surface of single fibroblasts. The possible mechanism of the assembly of fibronectin structures]. / Raspredelenie fibronektina na poverkhnosti odinochnykh fibroblastov. Vozmozhnyi mekhanizm sborki fibronektinovykh struktur.

Distribution of fibronectin on the surface of lamelloplasm and endoplasm of single cultured mouse embryo fibroblasts was studied by means of indirect immunofluorescence technique. Large fibronectin fibrillae were located on the surface of endoplasm mainly, while "spots" and "streaks" of fibronectin dominated on the surface of lamelloplasm. Colcemid-treated cells had approximately the same distribution whereas cytochalasin B-treated cells were characterized by a spotty fluorescence alone. In contrast, in dense cultures of colcemid-treated cells fibronectin network underwent tearing, while it remained unchanged in cytochalasin B-treated cells. The centripetal movement of the fibronectin--receptor complexes along the cell surface from lamelloplasm into endoplasm (or the natural capping of fibronectin receptors) seems to play an important role in the assembling of fibronectin fibrillae.