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Biomedical subjects

R G Webster

Publications and source records attributed to R G Webster.

At least 433 records · Page 24Linked to original sources
PubMed1972

The origin of pandemic influenza.

Serological tests, using antisera specific to the surface subunits of the viruses (e.g., antisera to the haemagglutinin subunits devoid of any antineuraminidase or anti-host antigen activity) showed that the haemagglutinin subunits of the Hong Kong virus were, immunologically, distinct from the subunits of the preceding A/Asian strains. On the other hand, the neuraminidase subunits of the Hong Kong virus are related to those of the A/Asian strains. The haemagglutinin subunits of influenzaviruses are composed of two pairs of light and heavy polypeptide chains and it was found that the amino acid sequence of the light and heavy chains from the haemagglutinin subunits of the Hong Kong virus differed remarkably from those of the preceding A/Asian strains. These findings suggest that Hong Kong virus did not arise by mutation from a pre-existing human strain and that it probably arose by the selection of a genetic recombinant in a partially immune population. It is postulated that the recombinant was formed as the result of the mixed infection of an animal or bird with an animal or avian influenzavirus and a human A/Asian strain. The animal (or avian) virus could have donated the haemagglutinin subunits of A/Hong Kong/1/68 virus and the neuraminidase subunits could have come from the human A/Asian strain.

Antigens, Viral↗
PubMed1972

Antibodies to human influenzavirus neuraminidase (the A-Asian-57 H2N2 strain) in sera from Australian pelagic birds.

Sera collected from Australian pelagic birds specifically inhibited the neuraminidase of the Asian/57 (H2N2) strain of human influenzavirus. Neuraminidase inhibition titres of some sera were high and the avidity of the inhibitor was comparable to that of specific antibody. The neuraminidase of A/Hong Kong/1/68 (H3N2), which has undergone considerable antigenic drift in man since 1957, was inhibited to a lesser extent by the bird sera, while the neuraminidases of the A/BEL/42 (H0N1) and A/FM/1/47 (H1N1) strains were not inhibited at all. The inhibitor could be removed from the sera by adsorption with A/57 virus particles, but not by particles of A/BEL or A/FM1 viruses. These results suggested that the inhibitor in the bird sera was specific antibody. The antibodies to A/57 neuraminidase were found in sera from wedge-tailed shearwaters (Puffinus pacificus) and noddy terns (Anous minutus) nesting on islands off the north-east coast of Australia. They were not found in sera from bridled terns (Sterna anaetheta) or brown gannets (Sula leucogaster) nesting on the same islands. Antibodies to A/57 neuraminidase were also detected in sera from short-tailed shearwaters (Puffinus tenuirostris), which migrate around the Pacific Ocean, suggesting that these birds may be responsible for bringing avian influenzaviruses from areas in the Northern Hemisphere into Australian coastal waters.

Animals↗
PubMed1969

Disruption of myxoviruses with Tween 20 and isolation of biologically active hemagglutinin and neuraminidase subunits.

Myxoviruses were disrupted with Tween 20 at high pH, and the major surface antigens were separated in biologically active form. The neuraminidase had a sedimentation coefficient of 10.8S, and the hemagglutinin had a sedimentation coefficient of 8.1S. Electron microscopic examination of negatively stained preparations revealed structures identical in size and morphology to the neuraminidase and hemagglutinin subunits described by others. Inhibition of neuraminidase activity by antibody to the hemagglutinin which occurred with intact viruses (probably for "steric" reasons) did not occur after the viruses were disrupted with Tween 20. Serological assays for neuraminidase were possible in the presence of the mild surfactant, whereas serological assays for hemagglutinin were possible after removal of the reagent. Disruption of myxoviruses with Tween 20 therefore provides a method for the independent study of these antigens during antigenic drift.

Animals↗
PubMed1969

Some properties of influenza virus nucleocapsids.

Nucleocapsids released from influenza virions by sodium deoxycholate sedimented heterogeneously in sucrose gradients. Highly infectious virus (complete) preparations yielded nucleocapsids with peak distributions at 64 and 56S; von Magnus type virus (incomplete) lacked 64S nucleocapsids. Treatment of influenza virus nucleocapsids with pancreatic ribonuclease rendered the associated viral ribonucleic acid (RNA) molecules acid-soluble, indicating that capsid proteins do not completely surround the viral RNA's. However, the capsid proteins remained associated after enzymatic hydrolysis of the RNA, as judged by persistently high sedimentation rates. Sedimentation rates of viral nucleocapsids reflected the sedimentation rates of the associated RNA's: 64S nucleocapsids contained 18S RNA, whereas 56S nucleocapsids contained 15S RNA, although in both cases RNA's sedimenting at 4 to 13S were also recovered. Furthermore, just as incomplete virions lacked 64S nucleocapsids, they also lacked 18S RNA. These findings support the hypothesis that the influenza virus genome is divided among several distinct pieces of RNA.

Journal Article↗