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L Döhner

Publications and source records attributed to L Döhner.

At least 37 records · Page 2Linked to original sources
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↗
PubMed1983

Differentiation of influenza A virus nucleoproteins in enzyme-linked immunosorbent assay.

The serum antibody titre to the nucleoprotein (NP) of the influenza virus recombinant MRC-11 was determined in virus strains A/USSA/5/80 (H3N2), A/Hong Kong/8/64 (H3N2), A/duck/Ukraine/63 (Hav7Neq2) and in a recombinant strain between A/tern/Frunse/334/78(Hav4Nav1) and A/PR/8/34(H0N1) using the enzyme-linked immunosorbent assay (ELISA). Significant differences between the NP of these strains were found proving the usefulness for ELISA for such investigations.

Antigens, Viral↗
PubMed1983

Role of genes 4 and 6 for the expression of some biological properties of influenza virus A/PR/8/34.

Genetic composition and biological properties of influenza virus recombinants A/PR/8/34 (H1N1) and A/Greifswald/6/74 (H3N2) were analysed. The haemagglutinin (HA) gene of the strain A/PR/8/34 was shown an important part of the gene complex determining the virulence for mice, the yield of HA and the plaque forming capacity. The exchange of the HA gene with that of an another strain led to a drastic reduction of these properties. On the other hand, the introduction of the HA gene of A/PR/8/34 strain into the genome of an another strain, did not render the latter virulent for mice. The production of H3 HA proceeded at an about 5-fold higher extent when the H3-gene was cooperating with the genes of A/PR/8/34 in contrast to the genes of A/Greifswald/6/74.

Animals↗
PubMed1983

[Koch's postulates and virology].

It is shown, that the postulates of R. Koch are mainly devoted to the explanation of all symptoms of infectious diseases as a direct or indirect consequence of the action of the infectious agents. By this, Koch has directed the further work to the elucidation of the conditions for the occurrence of infectious processes, of the host-parasite relations and of the mechanisms of pathogenesis. Up to now the development of virology was substantially influenced by the realization of these principles which will also in future help to elucidate the remaining unsolved etiological problems of virology.

Animals↗
PubMed1982

[Not Available].

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Allergy and Immunology↗
PubMed1982

Studies on some genetic properties of antigenic recombinants of influenza viruses.

Two groups of antigenic recombinants Hav4N1 were obtained by recombination of human influenza virus H0N1 with two avian influenza viruses isolated from ducks in 1956 and terns in 1978 and possessing the same surface antigen Hav4 Nav1. Recombinants obtained by crossing A/PR/8/34 and A/duck/CSSR/56 viruses showed a lower ability to reproduce at optimal and lowered temperatures and differed in the thermosensitivity of haemagglutinin and neuraminidase. An analysis of virus-specific proteins of the recombinants revealed different combinations of genes coding for internal (Pl, NP) and nonstructural (NS1) proteins. Recombinants obtained by crossing A/PR/8/34 and A/tern/Frunze/334/78 viruses possessed a thermostable haemagglutinin; they produced plaques of a size characteristic of avian influenza but, as distinct from the latter, they were practically not eluted from fowl erythrocytes. Polypeptide analysis of these recombinants showed that the genes coding for NP, M and NS1 proteins were inherited from the A/tern/Frunze/334/78 strain.

Antigens, Viral↗
PubMed1981

Genome analysis of influenza A virus strains isolated during an epidemic of 1979-1980.

The genome and polypeptides of influenza A virus H3N2 strains isolated during the epidemic of 1979-1980 in the U.S.S.R. and G.D.R. have been analysed. Five varieties of H3N2 strains differing in a number of genes have been found. The isolates of the first group was similar to the A/Texas/1/77 strain in all the genes; the isolates of the second group were similar to the A/Bangkok/1/79 strain in all the genes; the strain representative of the third variety, contained all the genes except gene 4 close to those of the A/Bangkok/1/79 strain; the isolates of the fourth group contained genes 7 and 8 similar to those of the A/Bangkok/1/79 strain while the other genes corresponded to those of no strains under comparison; the viruses of the fifth group contained gene 3 similar to that of A/Moscow/406/76 strain, gene 7 was similar to that of A/Texas/1/77 strain and the other genes differed from all other strains compared. The data obtained indicate that during an influenza epidemic occurring in certain region several influenza virus varieties of the same serotype can circulate simultaneously, differing not only in the antigenic specificity of the haemagglutinin, but also in other genes.

Disease Outbreaks↗
PubMed1978

[Radial hemolysis in the diagnosis of influenza virus infections].

Some of the parameters of the radial haemolysis test were studied, and the test was used to determine antibody titres of sera obtained from patients involved in the epidemic outbreak of influenza-A/Port Chalmers, 1975. The sensitivity of the method was found to depend on the degree of erythrocyte sensitisation. An enlargement by 40 per cent of the haemolytic halo diameter should be considered and treated as antibody rise, if the reaction was to used in serological diagnosis under the conditions tested. The findings were in agreement with the complement fixation reaction in 48 per cent of all cases and with the haemagglutination inhibition test in 53.8 per cent.

Antibodies, Viral↗
PubMed1978

[Genetics of influenza viruses].

An account is given of important fundamentals, working methods, and recent results in the context of influenza virus genetics. Reference is made to the potentials implied in gene mapping and to the possibility of elucidating the correlations between the single gene and all biological properties of the influenza virus. Discussed against that background are the polyacrylamide electrophoresis of virus RNA, hybridisation with complementary RNA, immunological and chemical differentiation of gene products, as well as the use of defect mutants and of recombinant formation. It is shown that successful elucidation of the genesis of new virus strains is possible by means of those methods which also enable the preparation of virus strains with desired properties. This is likely to open up new horizons for more progress in the context of immunoprophylaxis against virus influenza.

Genes, Viral↗