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V P Grachev

Publications and source records attributed to V P Grachev.

At least 19 recordsLinked to original sources
PubMed2001

Evaluation of the new control methods for oral poliomyelitis vaccine.

In the draft recommendations for production and control of OPV the WHO proposed new control methods: (i) mutant analysis with PCR and restriction enzyme cleavage (MAPREC) assay that allows evaluation of poliovirus population heterogeneity at the molecular level; (ii) neurovirulence (NV) test using transgenic mice susceptible to polioviruses and (iii) control of the seed lots for the presence of the simian virus 40 (SV40) DNA sequence. This paper is focused on our experience in the practical implementation of the new methods at the Institute of Poliomyelitis and Viral Encephalitides (IPVE). Using methods based on PCR we have demonstrated that working seed viruses used by IPVE for OPV production are free from SV40 DNA sequences. Our experience on the conduction of the OPV type 3 control using TgPVR21 mice NV test (seven vaccine lots) and the MAPREC assay (more than 150 samples of single harvests and monovalent bulks) showed that these methods may be used instead of the monkey NV test, because they could not pass the vaccine failed monkey NV test. The necessity for single harvests control is discussed.

Animals↗
PubMed2001

Poliomyelitis in Russia in 1998-1999.

After introducing surveillance for poliomyelitis and AFP cases in the Russian Federation in 1998, 740 AFP cases have been registered in 1998-1999, and 18 of that number were considered as vaccine-associated paralytic poliomyelitis (VAPP). Of 18 cases 11 were classified as VAPP of vaccine recipients and confirmed by virus isolation; from two of the vaccine recipients virus was not isolated, and five were poliomyelitis cases in contact non-vaccinated children. In all the cases the disease was characterised with the typical clinical picture with residual pareses and paralyses. One case was fatal. Vaccine virus type 3 has been isolated from all the vaccine recipients. The MAPREC test has shown that the quality of monovaccine type 3 bulks used for vaccinating these children did not differ from the quality of other bulk vaccines produced by the Chumakov Institute of Poliomyelitis. Patients surveyed for gammaglobulin were positive. Polioviruses type 1 isolated from two of the contact cases had changed antigenic properties and were recombinants of types 1 and 2.

Feces↗
PubMed1991

Viral safety of biological products in WHO policy.

The production and quality control of biological products are regulated by the different national and international requirements. One of the many functions of WHO is to develop an international consensus on basic criteria for the acceptability of biological products. These include general and international requirements for the production of individual biological products (vaccines, interferons, blood and blood products, etc.). Production and control of biologicals includes control of substrates, products during manufacture, and the final lots. By means of the application of these international requirements and guidelines, biological products can be manufactured with high quality, safety--especially viral safety--and efficacy.

Biological Products↗
PubMed1985

Recombinants between attenuated and virulent strains of poliovirus type 1: derivation and characterization of recombinants with centrally located crossover points.

Recombinants with a centrally located crossover point were selected from crosses between poliovirus type 1 strains and intertypic (type 3/type 1) recombinants. Two such recombinants were characterized in some detail. In one of them (v1/a1-6), the 5' half of the genome was derived from a virulent type 1 strain, while the 3' half came from an attenuated type 1 strain. The genome of the other recombinant (a1/v1-7) had the reverse organization, with the 5' and 3' halves being derived from the type 1 attenuated and virulent strains, respectively. As deduced from the RNase T1 oligonucleotide maps, the a1/v1-7 genome also had a relatively short centrally located insert of the poliovirus type 3 origin. Both recombinants exhibited ts phenotypes. The RNA phenotypes of the recombinants corresponded to that of the parent donating the 3' half of the genome, v1/a1-6 and a1/v1-7 expressing RNA- and RNA +/- characters, respectively. Despite being a ts RNA- virus, v1/a1-6 proved to be neurovirulent when injected intracerebrally into Cercopithecus aethiops monkeys, although it exhibited a somewhat diminished level of pathogenicity as compared to its virulent type 1 parent. Recombinant a1/v1-7 behaved as an attenuated strain. These data supported our previous conclusion drawn from the experiments with intertypic poliovirus recombinants that the attenuated phenotype of poliovirus depends largely on the structure of the 5' half of its genome, although mutations of the 3' half may alleviate the virulence of the virus to a degree.

Base Sequence↗
PubMed1985

Neurovirulence of the intertypic poliovirus recombinant v3/a1-25: characterization of strains isolated from the spinal cord of diseased monkeys and evaluation of the contribution of the 3' half of the genome.

A tsRNA- intertypic recombinant, v3/a1-25, which has the 5' and 3' halves of the genome derived from the neurovirulent type 3 poliovirus strain 452/62 3D and the attenuated type 1 poliovirus strain LSc-gr3, respectively, was previously shown to cause severe paralytic poliomyelitis after intracerebral inoculation of monkeys. To ascertain whether the illness was caused by the recombinant itself or by temperature-resistant trRNA+ mutants that might have arisen in the inoculated monkeys, five independent virus strains have been isolated from the spinal cord of the diseased animals. While two of these isolates exhibited RNA+ and RNA +/- phenotypes, respectively, the other three strains retained the parental RNA- character. Except for the RNA+ strain, the RNase T1 oligonucleotide maps of the genomes of all the isolates revealed only a minimal deviation from the parental pattern. These results were interpreted to mean that v3/a1-25 is intrinsically neurovirulent despite the presence of a tsRNA- mutation(s) in the 3' half of its genome. Nevertheless, this mutation, or other peculiarities of the 3' half of the recombinant genome, may somewhat alleviate the pathogenicity of the virus. This notion was inferred from the fact that, when used in a relatively small dose (about 10(3) p.f.u.), v3/a1-25 appeared to exhibit a lower level of neurovirulence compared to either the wild-type parent 452/62 3D, or a closely related intertypic recombinant having the genome 3' half derived from a neurovirulent trRNA +/- type 1 poliovirus strain. The problem of genetic determination of poliovirus neurovirulence and attenuation is briefly discussed.

Animals↗
PubMed1984

Construction and properties of intertypic poliovirus recombinants: first approximation mapping of the major determinants of neurovirulence.

An attempt was made to map, in a general way, the region of the poliovirus genome that is responsible for the neurovirulent and attenuated phenotypes of different virus strains. A set of four recombinants was investigated, one described previously (E. A. Tolskaya, L. I. Romanova, M. S. Kolesnikova, and V. I. Agol, 1983, Virology 124, 121-132) and three obtained in the present work with the following genetic structure: a 5' end-adjacent segment of the genome derived from either a virulent strain (452/62 3D), or from an attenuated strain (Leon-2) of poliovirus type 3, the remaining RNA sequences being derived from either a virulent strain (Mgr), or an attenuated strain (LSc-gr3) of poliovirus type 1. The crossover points in the recombinant genomes were centrally located, somewhere between the gene(s) that determines antigenic specificity of the virus and the locus that determines resistance of virus multiplication to low doses of guanidine. The recombinant nature of the newly selected clones was definitively established by mapping RNase T1 oligonucleotides of their genome. The recombinants were characterized with respect to their ability to produce infectious progeny and synthesize viral RNA at an elevated temperature. Neurovirulence of the recombinants was assayed by intracerebral inoculation of monkeys. Irrespective of the origin of the 3' end-adjacent segment of the genome, the recombinants that inherited the 5' end-adjacent segment from the neurovirulent parent were neurovirulent, whereas the recombinants with the 5' end-adjacent segment derived from the attenuated parent were not. The results suggest that the major determinants of neurovirulence of these recombinants (and by inference, of their parental viruses) reside in the 5' end-adjacent segment of poliovirus genome, known to code for capsid proteins.

Animals↗
PubMed1984

[Characteristics of the growth of cells on a surface of limited area].

An original technique was used to study the growth pattern of cells of varying origin on limited areas (from 1 to 0.01 mm2). During cultivation on limited areas, the growth of primary and continuous fibroblast-like cells was inhibited, whereas that of normal and transformed epithelioid cells was not. The growth of fibroblast-like skin cells of diploid lines and human embryonal muscles was completely inhibited in cultivation on 0.1-0.02 mm2 areas and partially inhibited in cultivation on 0.03-0.16 mm2 areas. Other normal fibroblast-like cells used in the experiment were also marked by growth inhibition of varying degree during cultivation on limited areas. The technique suggested and the data thus obtained may be used for studying substrate-cell and cell-cell interactions, selection of epithelioid cells, and the development of optimal microcarrier technology for cell cultures.

Animals↗
PubMed1984

[Phenomenon of delayed disruption of telomeric links between chromosomes in polykaryocytes formed from human-Chinese hamster hybrid cells].

The clones MOM-8-1 and MOM-8-3 of human--Chinese hamster cell hybrids were used for induction of the phenomenon of delayed disruption of the telomeric links between chromosomes. Colcemide (0.08 microgram/ml) and 5-bromodeoxyuridine (20 micrograms/ml) were present in cell culture for 30 hours. The dicentrics were observed in tetraploid, hypotetraploid and hypodiploid metaphases. No differences between the clones were found. The hybrid cells were the second object in which the phenomenon under discussion was reproduced.

Animals↗
PubMed1983

A study of candidate rabies vaccines for a national reference preparation for the evaluation of antigenic potency.

An unconcentrated and a concentrated lot of rabies vaccine prepared in Syrian hamster kidney cell culture from the Vnukovo-32 strain have been examined for their suitability as national reference preparations for rabies vaccine. The antigenic potencies of the preparations were assessed by the NIH test using both fixed and street strains of rabies virus and by the method of antibody induction. The candidate vaccines were calibrated in comparative assays with the WHO 3rd International Reference Preparation of Rabies Vaccine (IRP3). The correlation between the level of virus-neutralizing antibody and the resistance of mice to intracerebral challenge with a fixed rabies virus strain was studied. The candidate vaccines were also examined by the thermal degradation test. It was found that both vaccines had appropriate antigenic potency and thermostability to be used as a national reference preparation of rabies vaccine.

Animals↗
PubMed1983

[Comparative study of the reactogenicity and immunogenicity of new Soviet and commercial vaccines for preventing Japanese encephalitis].

In this article the results of testing Soviet vaccines for the prophylaxis of Japanese encephalitis, cell-culture inactivated adsorbed liquid vaccine and brain-tissue purified dried vaccine, are generalized and the comparison of their reactogenicity and immunogenicity characteristics with those of a similar commercial preparation manufactured by Toshiba Kagaku Kogyo Co., Ltd. (Japan) is made. Cell-culture inactivated liquid vaccine has proved to be the optimal preparation: it produces the most prolonged and intensive immunity and, when introduced by two methods, shows low reactogenicity.

Adolescent↗
PubMed1982

[African green monkey cell line RAMP simultaneously resistant to 8-azaguanine, 6-mercaptopurine, and 6-thioguanine].

African green monkey RAMT cell line was isolated from the permanent cell line 4647 in a medium containing 10 micrograms/ml 8-azaguanine, 6-mercaptopurine, and 6-thioguanine. The RAMT cells cannot grow in a medium containing thymidine, hypoxanthine, aminopterine and glycine because of the lack of hypoxanthine utilization due to hypoxanthine phosphoribosyltransferase deficiency. It was shown that 40% of the RAMT cells contain 57-58 chromosomes, and 20% of the cells are tetraploid. Like normal karyotype of the animal, the RAMT cells have two chromosomes with nucleolar organizer regions (NOR). One of them has an additional segment on the short arm and a large NOR revealed by silver staining. The cytoplasm of the RAMT cells was not found to have mycoplasma-like particles detected by the Hoechst 33258 fluorescent method. These characteristics enable the use of the RAMT cells for somatic cell hybridization.

Animals↗
PubMed1982

[Spontaneous sister chromatid exchanges in cultured African green monkey cells].

The frequencies of sister chromatid exchanges (SCE) were studied in primary kidney cell culture, diploid cell line 5018, pseudodiploid spontaneously transformed cell line 4647 and hypotetraploid cell line 455 of the African green monkey. Bromodeoxyuridine was used at a concentration of 10 micrograms/ml. The slides were stained with acridine orange and Giemsa for sister chromatid differentiation. In the first three cases, SCE were scored in 100 metaphases of each culture. The distribution of cells from the number of SCE differs from the normal law and was approximated fairly well by the lognormal distribution pattern. The geometrical means of SCE per cell were 6.90 for cells in primary culture, 9.26 for cells of diploid line 5018; 4.50 for cells of pseudodiploid transformed line 4647 and 9.76 for cells of hypotetraploid transformed line 455.

Animals↗
PubMed1981

[Immunological indices of human vaccination against tick-borne encephalitis using inactivated preparations with a varying concentration of the viral antigen].

The results obtained in the determination of the immunological activity of 3 types of formalin-killed tissue-culture tick-borne encephalitis vaccine, commercial non-concentrated and concentrated by 2 different methods, in humans are presented. Judging by the data of 3 serological tests and the blast transformation test, the concentration of killed tick-borne encephalitis virus enhanced immune response to vaccination. The intensity of this response correlated with the mouse protection capacity of the vaccine batches under test. An increase in the content of viral particles in the preparation is considered to be a promising approach to enhancing the effectiveness of vaccination against tick-borne encephalitis.

Adult↗
PubMed1980

[Chromosome nucleolus organizer regions of the African green monkey].

The silver staining Ag-I for detection of nucleolar organizer regions (NOR) in the African green monkey chromosomes was used. NOR were situated on the secondary constrictions of one pair of homologous marker chromosomes and consisted of two parts. A block of condensed chromatin was seen in the middle of the despiralized portion corresponding to the secondary constriction. The data suggest that the stalks of satellites of chromosomes, rather than satellites themselves, are regions of nucleolar organizer.

Animals↗