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W R Dowdle

Publications and source records attributed to W R Dowdle.

At least 55 records · Page 3Linked to original sources
PubMed1975

Seroepidemiologic survey of coronavirus (strain 229E) infections in a population of children.

The indirect hemagglutination (IHA) test for coronavirus 229E antibodies was used for serodiagnostic and seroepidemiologic studies in a population of children. Subjects ranged in age from 5 to 19 years and lived in a home which participated in a longitudinal surveilance of respiratory illness (1960-1968). During this period 1477 respiratory illnesses were observed; 63 (4%) were associated with sero-response (fourfold or greater antibody rises) to 229E. An additional 105 sero-responses were associated with unreported or subclinical illness. The frequency of these infections was cyclical, and 229E and coronavirus OC 43 infections peaked in different years among the same population. Sero-responses occurred mainly in the fall, winter and spring quarters. Preexisting antibody was demonstrated in one-third of the children with 229E sero-responses. Clinical studies indicated that the most frequent complaints with 229E infections were sore throat, coryza and cough, and the most frequent findings were pharyngeal injection, coryza and fever.

Adolescent↗
PubMed1975

Reference equine antisera to 33 human adenovirus types: homologous and heterologous titers.

Equine antisera to human adenovirus types 1 to 33 were prepared and evaluated by hemagglutination-inhibition and serum neutralization tests. Detailed data on the potency and purity of the immunizing antigens were tabulated as one means of evaluating the antisera. Most of the 52 hemagglutination-inhibition and 25 serum neutralization major or minor heterotypic responses among the equine antisera were observed at similar levels in previous studies with rabbit antisera and appeared to represent genuine antigenic relationships among the human adenoviruses. Equine antisera to human adenoviruses 1 to 33 and a similarly packaged normal horse serum served as lots of fully tested sera for definitive typing of isolates and as reference standards for evaluating other antisera.

Adenoviridae↗
PubMed1975

Application of the single radial diffusion test for assay of antibody to influenza type A viruses.

Single radial diffusion (SRD) tests for antibodies to influenza type A hemagglutinin, neuraminidase, nucleoprotein, and matrix protein antigens were compared with conventional hemagglutination inhibition, neuraminidase inhibition, and complement fixation tests. Sera used in this study were obtained in 1968-1969 from volunteers before and after vaccination and before and after an ensuing epidemic of Hong Kong influenza. The SRD test compared favorably with conventional tests for assessment of vaccine- or infection-induced rises in antibody titers to influenza type A viruses. Little linear relationshiip was seen between zone areas with SRD and titers with conventional tests, suggesting that the SRD test may detect antibody of different quality or specificity. The SRD seemed equal to the hemagglutination inhibition test for predicting susceptibility to influenza. SRD is a simple test for the recognition of antibody to various antigenic components of the influenza virus and could prove to be a valuable epidemiological tool.

Antibodies, Viral↗
PubMed1975

Coronaviridae.

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Coronaviridae↗
PubMed1975

Orthomyxoviridae.

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Orthomyxoviridae↗
PubMed1974

Inhibition of virus release by antibodies to surface antigens of influenza viruses.

When influenza virus was mixed with antisera to its surface subunits before inoculation of cell cultures, anti-hemagglutinin antibodies neutralized infectivity but anti-neuraminidase did not. When the antisera were added after infection of cell cultures, anti-hemagglutinin and anti-neuraminidase antibodies were equally effective in reducing virus titers in culture fluids. Decreased virus titers were not due to interference of antibody with assay and were not accompanied by a reduction in the synthesis of hemagglutinin and neuraminidase subunits. Both antisera also effectively prevented in vitro virus spread. Inhibition of virus release by neuraminidase antibody appeared unrelated to its antienzyme property. Hydrolysis of N-acetyl neuraminic acid residues of infected host cells proceeded unimpaired in the presence of subunit antisera. Anti-hemagglutinin and anti-neuraminidase antibodies may act to prevent virus release by binding newly formed virus subunits to each other and to anti-genically altered cell membranes.

Adsorption↗
PubMed1974

Antigenic variation in current influenza A viruses: evidence for a high frequency of antigenic 'drift' for the Hong Kong virus.

A new antigenic variant of the Hong Kong (H3N2) subtype of influenzavirus type A is described. The variant, A/Port Chalmers/1/73 (H3N2), was first isolated in Australasia in the autumn of 1973 and subsequently became the predominant influenza A variant in most areas of the world, replacing the previously prevalent strain A/England/42/72 (H3N2). The 1973 variant shows antigenic differences from former Hong Kong variants in both haemagglutinin and neuraminidase antigens. The application of immuno-double-diffusion tests and single-radial-diffusion tests in the antigenic analysis of new variants of the influenzavirus is also described. It is emphasized that since new variants of the Hong Kong virus have appeared in the successive years 1971, 1972, and 1973, the annual frequency of antigenic "drift" for the Hong Kong virus is higher than was recorded for the "Asian" influenzavirus (H2N2) in the first 5 years of the latter's prevalence from 1957 to 1962, during which period little antigenic variation occurred.

Antibodies, Viral↗
PubMed1974

A simple double immunodiffusion test for typing influenza viruses.

The identification of influenza virus type has traditionally been based on the characterization of internal nucleoprotein (NP) antigens by the complement fixation (CF) test. Because this test is complex and time-consuming, it is used only infrequently. In this report we describe a double immunodiffusion (DID) test, which is proposed as a replacement for the CF test for the typing of influenza viruses. The DID test is simple and requires only the allantoic fluid content of a single infected embryonated egg. Virus from the infected fluid is precipitated with mild acid and disrupted by detergent. Anti-NP or anti-matrix protein (MP) antibody is equally effective in most instances for typing influenza isolates by this test. The latter is preferred, however, since it seemed to be slightly more sensitive than anti-NP antibody.

Allantois↗
PubMed1973

Antigenic variants of influenza B virus.

From 1967 to 1971 little antigenic variation was detected in the prevalent influenza B viruses but in December 1972 a new antigenic variant of influenza B was isolated in Hong Kong from sporadic cases of influenza. The new variant, B/Hong Kong/5/72, possessed a haemagglutinin antigen which showed considerable antigenic differences from that of former influenza B strains while its neuraminidase antigen was closely related to that of the earlier, 1967-71, isolates. The B/Hong Kong/5/72 variant became the predominant influenza B strain in the United Kingdom by early summer 1973, and in both the United Kingdom and Japan this strain was associated with outbreaks of influenza. Strains antigenically intermediate between the 1967-71 isolates and B/Hong Kong/5/72 were isolated in a number of countries, often concurrently with B/Hong Kong/5/72-like strains.Serological studies indicated that antibody to B/Hong Kong/5/72 was infrequent in the populations in the United Kingdom and the U.S.A., suggesting the possibility of future epidemic activity associated with the new variant. In addition, conventional inactivated influenza vaccines containing the older influenza B isolates given to volunteers stimulated poor antibody responses to B/Hong Kong/5/72 virus. These studies indicate the desirability of immunizing high risk patients against B/Hong Kong/5/72-like viruses before the coming influenza season. Vaccine containing the new variant influenza B strain are currently available in the United Kingdom.

Antibodies, Viral↗
PubMed1973

Influenza A neuraminidase antibody assay with sensitized erythrocytes.

Erythrocytes sensitized with purified neuraminidase (Hong Kong) antigens were used for assay of influenza A neuraminidase antibodies. The neuraminidase indirect hemagglutination test was equal to the neuraminidase hemagglutination-inhibition (enhancement) test and appeared to be better than the neuraminidase inhibition test for detection of fourfold or greater antibody rises in paired sera from influenza patients or vaccinees. It was better than both tests for detection of neuraminidase antibody. The neuraminidase indirect hemagglutination test is simple to perform and has the advantage of direct antigen-antibody assay.

Aldehydes↗
PubMed1973

Influenzavirus neuraminidase and neuraminidase-inhibition test procedures.

The adequate characterization of type A influenzaviruses requires the identification not only of the haemagglutinin but also of the neuraminidase. The neuraminidase-inhibition test, as performed in the two WHO international reference centres for influenza, is described and its use in other laboratories-particularly those collaborating in the WHO programme-is recommended.

Antigens, Viral↗
PubMed1973

Characterization and ecology of a type A influenzavirus isolated from a sheawater.

An influenzavirus isolated from a shearwater bird nesting on Tryon Island on the Australian Great Barrier Reef in 1971 has been more extensively characterized. Haemagglutinin subunits were isolated from the shearwater virus and from the antigenically related avian influenzaviruses A/turkey/Mass./65 (Hav6N2) and A/duck/Penn./69 (Hav6N1). Maps of the tryptic peptides from the heavy polypeptides (HA1) of the haemagglutinin subunits of the three viruses showed a number of differences, but peptide maps of the light polypeptides (HA2) were almost identical, suggesting that these had almost the same amino acid sequence. Extensive tests confirmed that the neuraminidase of the shearwater virus was not related antigenically to any known neuraminidase. The sera collected from pelagic birds nesting on islands in the Capricorn-Bunker group in 1970 were devoid of any antibodies to the shearwater virus, while a high proportion of the sera collected from birds on the same islands in 1972 (one year after the isolation of the shearwater virus) had antibodies to the haemagglutinin and neuraminidase of the shearwater virus, some to a high titre. Thus, the shearwater virus appeared to have only recently been introduced into the area from where it was isolated.

Animals↗