Biomedical subjects

Y Z Ghendon

Publications and source records attributed to Y Z Ghendon.

At least 19 recordsLinked to original sources

PubMed2005

The effect of mass influenza immunization in children on the morbidity of the unvaccinated elderly.

The objectives of these studies were to analyse the effect of mass influenza immunization in children on the morbidity of unvaccinated non-institutionalized elderly during an influenza epidemic. A mass vaccination campaign with vaccine was conducted in children aged 3-6 years attending kindergartens (57.4% of 6374) and aged 7-17 years attending schools (72% of 34237) in two communities of the Moscow region. The clinical effectiveness of vaccination was 60.9% for kindergartens and 68.8% for schools. There were 3.4 times fewer episodes of influenza-like illnesses and 1.7-2.6 fewer episodes in all seven diseases which are possible complications of influenza out of the 10 evaluated diseases in 158451 unvaccinated non-institutionalized elderly people during the influenza epidemic compared with the control communities. The differences were found to be statistically significant. Mass vaccination of children attending child institutions brought about a significant reduction of both influenza-like illnesses in children and influenza-associated illnesses in unvaccinated non-institutionalized elderly persons living in the home setting.

Aged↗

PubMed2005

Development of cell culture (MDCK) live cold-adapted (CA) attenuated influenza vaccine.

Optimal conditions are determined for growing cold-adapted reassortant strains of a live influenza vaccine in MDCK cell line cultivated in a fermenter with a serum-free medium and microcarriers. The studied MDCK cell line meet all national and WHO requirements for the finite cell lines used for the production of biological preparations. CA reassortant vaccine strains grown in such conditions which fully preserve its mutations and the mutations lead to amino acid substitution in all genome segments of the studied CA reassortants. Under optimal cultivation conditions, the output of a monovalent live CA influenza vaccine in a 10-l fermenter may reach 100,000 doses.

Adaptation, Physiological↗

PubMed1990

Genome and antigenic analysis of influenza A (H3N2) viruses isolated from an epidemic in a closed community of Carmelite nuns.

Eighteen influenza A (H3N2) viruses were isolated during a single outbreak in a closed community of Carmelite nuns. Serological analysis of the virus haemagglutinin (HAs), using a panel of monoclonal antibodies, demonstrated antigenic microheterogeneity. In contrast, no significant biochemical differences were detected in viral genes by RNA:RNA hybridisation or in structural or nonstructural polypeptides analysed by high-resolution polyacrylamide gel electrophoresis (PAGE) or by limited proteolysis followed by PAGE. Influenza A (H3N2) viruses isolated in the vicinity of the convent were distinguishable from each other and from the epidemic viruses isolated in the convent both antigenically and biochemically.

Adult↗

PubMed1986

Genome analysis of influenza B virus strains isolated during epidemics in boarding schools. Brief report.

Genetic analysis of influenza B virus strains isolated during concurrent epidemics (February-March 1982) in three physically separated schools was carried out using the RNA:RNA hybridization technique. The data supports the hypothesis that the influenza B virus epidemics in each school were initiated by different viruses and the variability of the strains in a closed community was found to be minor though some variants were detected.

Child↗

PubMed1986

Comparative studies of H3N2 influenza virus strains isolated in May-June, 1982, and in the subsequent epidemic in February, 1983: antigenic and genome analysis.

Comparative studies have been undertaken on the H3N2 influenza virus strains isolated in Leningrad in May-June, 1982 and those isolated in the subsequent winter epidemic in February, 1983. Analysis of the isolates with ferret antisera against standard influenza viruses of the H3N2 subtype and with monoclonal antibodies against A/Bangkok/1/79 virus revealed a considerable but similar degree of heterogeneity in the HA antigenic specificity of the strains isolated in the spring-summer, 1982, as in the winter, 1983, periods and also a close resemblance between the antigenic specificities of the strains of these two epidemics. However comparative genome analysis of the strains using cRNA:vRNA hybridization technique revealed that in terms of the gene homology, the influenza virus strains which circulated in the spring-summer period of 1982 resembled the strains responsible for the previous rather than subsequent epidemic.

Animals↗

PubMed1985

Analysis of the genome of influenza A virus strains (H3N2) isolated during the epidemic season of 1982-1983.

The cRNA:vRNA hybridization technique was used to analyse H3N2 influenza virus isolates obtained from influenza patients in the United Kingdom and the U.S.A. (Alaska) during the epidemic season of 1982-1983. The majority of isolates differed from reference H3N2 influenza virus strains A/Bangkok/1/79 and A/Philippines/2/82 as well as from one another in the homology of nearly all the genes. No identical strains were detected among the isolates including the ones isolated in the same town and at the same time.

Animals↗

PubMed1985

Interaction of M protein and RNP of fowl plague virus in vitro.

The ability of the fowl plague virus (FPV) M protein to form a complex with FPV RNP and to inhibit the RNP transcriptase activity in vitro depended on NaCl concentration and did not depend on the concentration of nonionic detergents. The results obtained indicate that the M protein-RNP links formed were of an electrostatic rather than a hydrophobic nature. As demonstrated using individual RNP components, vRNA and RNA-free protein structures, M protein formed complexes only with vRNA, and the complex formation was salt-dependent. Analysis of products formed in the in vitro system containing RNP of FPV in the presence of the M protein showed impairment in the transcription of all RNA segments. The degree of inhibition correlated with the size of a segment, transcription of high molecular weight RNA segments being inhibited significantly more than that of low molecular weight RNA segments.

Animals↗

PubMed1985

Comparative studies of A/Leningrad/134/57 wild-type and 47-times passaged cold-adapted mutant influenza viruses: oligonucleotide mapping and RNA-RNA hybridization studies.

Direct biochemical evidence for the existence of mutations in five of the RNA segments of the A/Leningrad/134/57 cold-adapted 47th passage mutant as compared with its wild-type progenitor has been obtained using two techniques. T1 oligonucleotide mapping of total viral RNA as well as of individual RNA segments revealed changes in RNAs 4, 5 and 6. Analysis of S1 nuclease-treated RNA-RNA hybrids on polyacrylamide gels revealed changes in at least one of the polymerase genes as well as in RNAs 4, 5, 6 and 7. These findings provide a direct demonstration for the existence of multiple mutations in the cold-adapted mutant vaccine strain.

Cold Temperature↗

PubMed1984

Biochemical and serological studies of influenza B viruses: comparisons of historical and recent isolates.

The genetic characteristics of 24 representative influenza B viruses isolated in widely different geographical areas of the world between 1940 and 1980 were analysed using either RNA:RNA hybridisation or oligonucleotide mapping. Additional biochemical characterisation included electrophoretic analysis of virus-induced polypeptides and virion RNAs. A panel of monoclonal antibodies to virus HA was used to investigate serological relationships between the viruses. The influenza B viruses examined constituted a genetically and serologically related group but mutational changes were detected in all eight genes of the viruses isolated in different eras and also in genes of viruses isolated in the same epidemic year. Regardless of the overall and dominating similarities, at a higher level of discrimination it was clear that certain genetic and serological relationships were more complex than expected and, for example, some recently circulating field viruses were apparently more closely related antigenically and genetically to viruses isolated five to twelve years previously than to other viruses isolated concurrently. No evidence of recombination with hitherto undescribed influenza B viruses and with genes coding for internal proteins was detected.

Antibodies, Monoclonal↗

PubMed1984

Studies of a recombinant which inherited the haemagglutinin from the human influenza virus A/Hong Kong/1/68 (H3n2) and other genes from influenza virus A/duck/Ukraine/1/63 (H3N8).

A recombinant (R3/3) has been obtained which inherited the gene coding for the haemagglutinin from human influenza virus A/Hong Kong/1/68 (H3N2), and seven other genes from influenza virus A/duck/Ukraine/1/63 (H3N8). The recombinant R3/3 had properties, a ts+ phenotype and a capability of reproducing in chick embryos, similar to those of the duck influenza virus, but, in contrast to this parent, had lost its ability to reproduce in organ cultures of colon of ducks and chickens as well as in monolayer cultures of chick embryo fibroblasts.

Animals↗

PubMed1984

Studies of fowl plague virus temperature-sensitive mutants with defects in synthesis of virion RNA.

Three different types of impairment in the synthesis of virion RNA (vRNA) were detected in three groups of temperature-sensitive (ts) mutants of fowl plague virus (FPV) having ts mutations in genes 1, 3 and 5 respectively. Normal synthesis of poly-(A+) cRNA, poly(A-) cRNA and vRNA was observed under non-permissive conditions early in infection in cells infected with the ts43 mutant having a ts mutation in gene 1 coding for the PB2 protein. However, 4 h after infection synthesis of vRNA ceased, synthesis of poly(A+) cRNA was reduced drastically, but the rate of poly(A-) cRNA synthesis was the same as that in cells infected with wild-type FPV. In cells infected with the ts 166 mutant having a ts mutation in gene 3, coding for the PA polypeptide, a drastic reduction was observed in poly(A+) cRNA synthesis under non-permissive conditions. Synthesis of poly(A-) cRNA was also reduced and synthesis of vRNA was not detected. The ts 60 mutant, having a ts mutation in gene 5 coding for the NP polypeptide, induced synthesis of all types of virus-specific RNA under non-permissive conditions, but the regulation of synthesis of vRNA and poly(A+) cRNA was affected, there being predominant syntheses of RNA segments 5 and 8 late in infection. In cells infected with mutants ts43 and ts 166 synthesis of virus-specific proteins was impaired, which reflected defects in the synthesis of virus-specific RNAs. The data obtained suggest that the PB2 protein may be contained in an enzyme complex responsible for synthesis of vRNA, that different enzyme complexes may be involved in the synthesis of poly(A-) cRNA and vRNA, and that the NP protein plays a significant role in the regulation of vRNA synthesis.

Cycloheximide↗

PubMed1984

Recombinant cold-adapted attenuated influenza A vaccines for use in children: molecular genetic analysis of the cold-adapted donor and recombinants.

A previously described cold-adapted attenuated virus, A/Leningrad/134/17/57 (H2N2), was further modified by 30 additional passages in chicken embryos at 25 degrees C. This virus had a distinct temperature-sensitive (ts) phenotype, grew well in chicken embryos at 25 degrees C, and failed to recombine with reference ts mutants of fowl plague virus containing ts lesions in five genes coding for non-glycosylated proteins (genes 1, 2, 5, 7, and 8). Recombination of A/Leningrad/134/47/57 with wild-type influenza virus strains A/Leningrad/322/79 (H1N1) and A/Bangkok/1/79(H3N2) yielded ts recombinants 47/25/1(H1N1) and 47/7/2 (H3N2). These recombinants inherited their ts phenotype and ability to reproduce in chicken embryos at 25 degrees C from the cold-adapted parent. Analysis of the genome composition of the recombinants obtained by recombination of the cold-adapted donor with wild-type influenza virus strains A/Leningrad/322/79(H1N1) and A/Bangkok/1/79(H3N2) showed that recombinants 47/25/1(H1N1) and 47/7/2 (H3N2) inherited five and six genes, respectively, from the cold-adapted parent, and hemagglutinin and neuraminidase genes from the wild-type strains.

Animals↗

PubMed1984

Location of ts defects in the genome of cold-adapted recombinant influenza A virus vaccine strains.

The ts phenotype and location of ts mutations were studied in the genome of parent viruses and those obtained by recombination of cold-adapted strains A/Leningrad/134/17/57 or A/Leningrad/134/47/57 with epidemic H1N1 and H3N2 influenza A virus strains. The epidemic H1N1 and H3N2 strains under study possessed a ts phenotype and contained ts mutations in one or two genes. The ts phenotype was lost following three clonings at 40 degrees C, suggesting that influenza virus strains isolated from humans may be heterogeneous and contain virions either carrying or not carrying the ts mutations in their genomes. Two cold-adapted strains possessing a distinct ts phenotype contained ts mutations in three (A/Leningrad/134/17/57 virus after 17 passages at 25 degrees C) or in five (A/Leningrad/134/47/57 variant after 30 additional passages at 25 degrees C) genes coding for non-glycosylated proteins. When compared with cold-adapted donor strains, the recombinants had either the same set or additional ts mutations. However, no ts mutation was detected in a gene which had been inherited from the donor strain. It is suggested that, in addition to the analysis of the genome composition, in cold-adapted recombinant influenza virus strains recommended as vaccine candidates it is necessary to control the number of genes containing ts mutations.

Acclimatization↗

PubMed1984

Ts mutations in the genome of cold-adapted variants of human influenza virus A/Krasnodar/101/59 (H2N2) at different passage levels and their reproduction in lungs of hamsters.

Human influenza virus A/Krasnodar/101/59 (H2N2) was passaged in chick fibroblast cultures in the presence of trypsin at suboptimal temperature. The virus which underwent 16 passages at 28 degrees C possessed cold-adapted (ca) and temperature sensitive (ts) phenotypes and formed larger plaques at the optimal temperature (33 degrees C). Its reproduction in the lungs of hamsters was decreased as evidenced by approximately 2.5 log10 lower titres; only one of 9 virus isolates from the lungs of hamsters acquired the ts +/- phenotype, although it had retained a ca phenotype. Recombination of this variant with ts mutants of fowl plague virus (FPV) revealed a ts mutation only in gene 4 of this variant coding for haemagglutinin (HA). The virus which had had 25 passages at 28 degrees C possessed the same properties as the previous variant, but all eight virus isolates from the lungs of hamsters retained the ts phenotype; the genome of this variant contained ts mutations in genes 1, 3, 4, 5 and 6. The mutation found in gene 8 was not a ts mutation. The virus, which underwent 25 passages at 28 degrees C and additional 15 passages at 27 degrees C, formed large plaques and alike to the previous variants it possessed the ca and ts phenotypes; however, its reproduction in the lungs of hamsters was decreased by 4.0 log10 and occurred in the lungs only of 4 out 16 infected animals. This variant contained ts mutations in genes 1, 3, 4, 5, 6 and 7 and a non-ts mutation in gene 8.

Animals↗

PubMed1984

Genome analysis of epidemic influenza virus strains isolated in 1979-1983.

Comparative studies on the electrophoretic mobility of double-stranded RNA segments constructed of the genome of isolates under study and of reference influenza virus strains of respective serotypes are suggestive for the evolution of majority of the genes of both A and B influenza viruses, including their genes coding for non-glycosylated proteins. Among influenza A and B virus strains which were circulating during the same epidemic, there were variants differing from each other in a number of genes including those coding for virion internal proteins. A recombinant (reassortant) detected among the influenza virus strains, which circulated in Moscow in 1979, contained the genes 4, 6, 7 and 8 identical with those of the reference H1N1 strain, and the genes 1, 2, 3 and 5 identical with those of the reference H3N2 strain. Comparative analysis of reference influenza virus strains, both the H3N2 serotype (being isolated from 1968 to 1979) and the H1N1 serotype (being isolated from 1977 to 1980) differing in the antigenic specificity of their haemagglutinin (HA) suggested the increasing variability of either genes coding for glycoproteins as well as for non-glycosylated proteins.

Disease Outbreaks↗

PubMed1984

Molecular characteristics and biological properties (genetic markers) of candidate strains for preparation of live influenza virus vaccines.

The biological and molecular properties of both virulent and vaccine types of influenza virus strains are reviewed, including their analysis in laboratory animals and in organ tissue cultures, as well as studies of their genome peculiarities. Methods are discussed for obtaining attenuated donor strains of influenza virus, and the properties of these strains are analysed. The methods of studying the genome composition and the genes carrying mutation lesions in recombinant vaccine strains obtained by recombination of an attenuated donor strain with current epidemic influenza virus variants are also reviewed.

Animals↗

PubMed1983

Studies on a temperature-sensitive mutant of fowl plague virus having a mutation in gene 7 coding for the M protein.

A fowl plague virus (FPV) temperature-sensitive mutant, ts 303/1 having a ts mutation in gene 7 coding for the matrix (M) protein has been obtained. The mutant induced synthesis of virus-specific RNA and polypeptides as well as ribonuclear protein (RNP) formation in cells under non-permissive conditions; however, haemagglutinin cleavage was reduced, functionally active haemagglutinin and neuraminidase were absent and virions were not formed. In mutant-infected cells at 36 degrees C haemagglutinin cleavage was also reduced and virions formed had an altered NP:M ratio as well as a decreased haemagglutinin content. A population of virions formed under these conditions was heterogeneous both in morphology and in buoyant density. The data obtained suggest that a mutation in the M proteins of orthomyxoviruses can affect processing of the haemagglutinin and impair final stages of virion morphogenesis.

Genes, Viral↗

PubMed1983

In vitro inhibition of negative strand virus transcriptase activity by proteins soluble in acidic chloroform-methanol.

The effect of proteins soluble in acidic chloroform-methanol (ACMS proteins) on the transcriptase activity of virus ribonucleoproteins (RNPs) in vitro has been studied. Experiments with ACMS membrane (M) proteins from type A and B orthomyxoviruses, as well as from vesicular stomatitis virus, showed that inhibition of the viral RNP transcriptase activity occurred when they interacted with M proteins isolated from viruses of a different serotype, or even of a different family. The presence of ACMS proteins capable of inhibiting the transcriptase activity of orthomyxovirus RNP in vitro was also detected in human blood plasma and among proteins produced by human leukocytes. Determination of the minimum concentration of M protein inhibiting the RNP transcriptase activity, and analysis of the fowl plague virus M protein-RNP complex formed in the in vitro system, showed that the M protein was capable of inhibiting RNP transcriptase activity at a M:RNP ratio of 0.1 to 0.2:1.

Blood Proteins↗