The study of acute and chronic toxicity of the sodium-, calcium-, iron-polygalacturonate pharmacological substance in rabbits.

The purpose of this study is the assessment of the acute and chronic toxicity of pharmacological substance sodium, calcium, iron-polygalacturonate (PG Na,Ca,Fe) in rabbits as one of the stages of preclinical studies. We studied an acute and chronic oral toxicity of PG Na,Ca,Fe, which stimulates the process of hemopoiesis, in male and female rabbits of the "Chinchilla". According to the results of the study of acute toxicity of PG Na,Ca,Fe, treating with it the rabbits of both sexes in doses of 0.5-5 g/kg has no toxic effect (LD50 greater than 5 g/kg). The histostructure of studied organs of animals, treated with preparations in a dose of 5 g/kg, did not differ from that of the animals of the control group. This study allow to classify PG Na,Ca,Fe as a preparation of the 6th class with respect to harmless drugs. An estimate of the chronic toxicity of PG Na,Ca,Fe at administration of preparation in the form of boluses to rabbits in doses 0.025, 0.262 and 0.5 g/kg of the body weight demonstrated that the general condition and behavior of animals did not differ from the norm. The data of hematological and biochemical studies of blood serum and urine, electrocardiographic studies, the study of the mass coefficients of the internal organs of the experimental rabbits, treated with PG Na,Ca,Fe in the mentioned doses for 60 days, compared to those obtained in the 30-day post-observation period, did not show significant changes with respect to the control and intact group of rabbits.

[Membrane-bound proteases of ompT+ and ompT- Vibrio cholerae strains].

AIM: Detection ofproteases in outer membranes (OM) of ompT+ and ompT- Vibrio cholerae strains of O1 and O139 serogroups. MATERIALS AND METHODS: Specific sterile preparations of OM were obtained by lysis of live V. cholerae cells by 4.5 M urea solution with subsequent differential centrifugation and treatment by nucleases. Extraction of OM proteins previously treated by sodium sarcosinate was carried out by Triton X-100 in the presence of EDTA. Protease and polypeptide spectra were studied in substrate and SDS electrophoresis. Sensitivity of proteases to inhibitors was determined in diffusion test in agarose gel containing substrate by using soy trypsin inhibitor (STI) and phenylmethylsulfonyl fluoride (PMSF). The presence of ompT was determined in PCR by using specific primers. RESULTS: According to PCR data 13 Vibrio cholerae O1 strains and 3 V. cholerae O139 strains isolated from clinical material as well as 22 V. cholerae O1 strains isolated from environmental objects contained ompT gene. 2 V. cholerae O1 human isolated strains, 9 V. cholerae O1 strains and 2 V. cholerae O139 strains isolated from the environment did not have ompT gene. By using SDS- and enzyme-electrophoresis in polyacrylamide gel quantitative and qualitative differences in composition of polypeptides and proteases of OM ompT+ and ompT- V. cholerae strains that hydrolyze gelatin, casein and protamine sulfate were detected. Inhibition of OM by STI and PMSF resulted in a decrease of their proteolytic activity. CONCLUSION: In preparations and extracts of ompT+ and ompT- V. cholerae OM up to 3 proteases some of which may be related to ompT-like were detected.

[M-29 human diploid cells line--a substrate for the production of antiviral vaccines].

AIM: Study of morphologic and karyologic characteristics of 5 russian human diploid cell lines (HDC). MATERIALS AND METHODS: 5 HDC lines and HDC strain MRC-5 were studied; RK-13 and Vero continuous cell lines were used; viruses: rubella (RA27/3), measles (L-16), epidemic parotitis (L-3). Cytogenetic analysis of HDC was performed by using DAPI differential staining method. RESULTS: M-29 line has characteristics that are similar to those of MRC-5 diploid cell strain. M-29 cell culture is not contaminated with foreign viruses, mycoplasmata, does not have oncogenic potency. CONCLUSION: M-29 line has high virus-productive properties for accumulation of measles, rubella and epidemic parotitis vaccine viruses and may be recommended as a substrate for the production of antiviral vaccines.

[Genetic characteristics of the causative agent of tick-borne encephalitis in Mongolia].

A patient with diagnosed meningoencephalitis and a history of tick bite died in Mongolia in 2008. The purpose of this paper is to characterize the virus causing the ill person's death. The virus was identified using the phylogenetic analysis of the 520-bp fragment of the tick-borne encephalitis virus (TBEV) genome, which codes the fragment of TBEV protein E between 52-223 amino acids. TBEV RNA was detected in the samples of medulla oblongata, cerebral cortex, and pia mater of brain, but not in the cerebellar tissue. The study virus fragment was genetically closest to the representatives of the Far East subtype. Its closest relative was virus 740-84 (GenBank EU878282) isolated from large-toothed redback voles (Clethrionomys glareolus) in Buryatia and greatly differed from the Far East virus Soffin. Two amino acid substitutions (H86R and VI7A) were detected within the study protein E fragment. The paper is the first to describe the causative agent of tick-borne encephalitis on the territory of Mongolia and to discuss the evolution and pathogenicity of TBEV.

[Biological functions of amyloids: facts and hypotheses].

Amyloids are fibrous protein aggregates which arise due to polymerization of proteins accompanied by their conformational rearrangement and formation of a specific "cross-beta" structure. The interest to amyloids is caused by their relation to a vast group of human and animal diseases called amyloidoses. Some of these diseases caused by prions, a specific type of amyloids, are transmissible. Besides mammals, prion amyloids are described in lower eukaryotes, where they underlie non-chromosomal genetic determinants. Though in humans and animals amyloids are usually associated with pathologies, the increasing number of findings suggests that in some cases acquisition of amyloid or prion form by a protein may be of biological significance. Here, we summarize data on biological significance of prion and nonprion amyloids obtained in a wide range of species, from bacteria to mammals.

Imaging of respiratory network topology in living brainstem slices.

Topology of neuronal networks contributes to their functioning but the structure-function relationships are not yet understood. In order to reveal the spatial organisation of the respiratory network, we expressed enhanced green fluorescent proteins in neurons in brainstem slices containing the respiratory kernel (pre-Bötzinger complex). The expression was neuron specific due to use of adeno-associated viral vector driving transgene expression from synapsin 1 promoter. Both neuronal cell bodies and their dendrites were labelled with high efficacy. This labelling allowed for enhanced spatial resolution as compared to conventional calcium-sensitive dyes. Neurons occupied about 10% of tissue volume and formed an interconnected network. Using custom-developed software, we quantified the network structure that had a modular structure consisting of clusters having transverse (dorso-ventral) orientation. They contained in average seven neurons and connections between the cells in different clusters were less frequent. This novel in situ imaging technique is promising to gain new knowledge about the fine structure and function of neuronal networks in living slice preparations.

[Yeast prions, mammalian amyloidoses, and the problem of proteomic networks].

Prion proteins are infective amyloids and cause several neurodegenerative diseases in humans and animals. In yeasts, prions are expressed as cytoplasmic heritable determinants of a protein nature. Yeast prion [PSI], which results from a conformational rearrangement and oligomerization of translation termination factor eRF3, is used as an example to consider the structural--functional relationships in a potentially prion molecule, specifics of its evolution, and interactions with other prions, which form so-called prion networks. In addition, the review considers the results of modeling mammalian prion diseases and other amyloidoses in yeast cells. A hypothesis of proteomic networks is proposed by analogy with prion networks, involving interactions of different amyloids in mammals.

[Interaction of ATP17 gene with SUP45 and SUP35 genes in Saccharomyces cerevisiae yeast]. / Vzaimodeistvie gena ATP17 s genami SUP45 i SUP35 u drozhzhei Saccharomyces cerevisiae.

Genes SUP35 and SUP45 have been identified in the saccharomycete yeast as genes controlling termination of translation in cytoplasmic ribosomes. However, many facts indicate that the control of translation termination is not the only function of these genes. This work is devoted to studying one of the pleiotropic effects of sup35 and sup45 mutations, a respiratory deficiency. The compensation for this deficiency in mutants for either gene can occur due to a mutation in the ATP17 gene encoding the f-subunit of mitochondrial F1F0 ATP synthase. It is assumed that the observed interaction can be related to the system of co-translational protein import into mitochondria.

[Virological and serological characteristics of outbreaks and sporadic cases of acute gastroenteritis]. / Virusologicheskaia i serologicheskaia kharakteristika vspyshek i sporadicheskikh sluchaev ostrogo gastroénterita.

Specimens from patients with gastroenteritis (GE) collected during outbreaks and from sporadic cases reported in the USSR in 1979-1984 were examined by electron microscopy (EM), enzyme immunoassay, rotavirus neutralization test in cell culture. All the winter-spring outbreaks and a considerable number (34.9%) of sporadic GE cases were caused by rotaviruses. The summer-autumn outbreaks were of non-rotavirus nature. In water-borne winter-spring outbreaks in adults, severe forms of GE with signs of dehydration were observed. Among infants, cases of virus-carrier state were detected. The rate of rotavirus detection by EM in winter-spring outbreaks depended on the time of specimen collection and decreased after 4 days from the onset of the disease. Apart from rotaviruses, adeno-, astro-, calici-, coronaviruses, and picornavirus-like particles were detected by EM in feces from GE patients.

Characterization of the continuous green monkey spleen cell line 455.

A continuous line of adult green monkey spleen cells has been established and designated 455 (according to the number of animal). Cell suspension for primary explantation has been prepared by perfusion and disaggregation of the organ. The obtained culture, which consisted of fibroblast-like cells with chromosome modal number 60, underwent 25 passages followed by ageing and death (line 455 D). At passage level 13 in 2 culture flasks with 455 D cells, islets of polygonal cells had developed within 35 days; they gave rise to a continuous cell line with chromosome modal number 110 (designated line 455). Line 455 has a high proliferative activity but low demands on the composition of culture media and it can be easily passaged with the bovine serum at concentration of 1-5%. It is highly sensitive to a number of viruses. It is not contaminated with bacteria, fungi, mycoplasmas or viruses, it does not have a tumourigenic activity. Hence, it is a promising cellular model for virological studies, in particular, for preparation of inactivated vaccines along with Vero and 4647 cells. The line 455 can be used for investigation of the problems of haemopoiesis and immunogenesis.

[Spontaneous contamination of primary green monkey kidney cell cultures by foamy virus]. / Izuchenie spontannoi kontaminatsii pervichnykh kul'tur kletok pochek zelenykh martyshek peniashchim virusom.

Examinations of 1653 batches of green monkey kidney cell cultures revealed contamination with foamy virus (FV) in 243 (16%) batches. From some of these cultures 65 strains of virus belonging to two serotypes were isolated. Tests on sera from 1122 monkeys revealed antibody to FV in 985 (87.8%) animals. No correlation between the presence of antibody in the serum and virus recovery from monkey kidney cell cultures was observed, however. This might be due either to the lack of the virus in the kidneys or to the failure in its isolation from primary cultures. Passages of cell cultures were shown to facilitate additional recovery of FV. These experimental results may be used for screening and selection of FV-free cultures and for control purposes in the course of vaccine manufacture.