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Biomedical subjects

L R Haaheim

Publications and source records attributed to L R Haaheim.

46 records · Page 3Linked to original sources
PubMed1980

Surveillance of the antibody status to current influenza strains in the Norwegian population. 2: Antibodies to the A/USSR/90/77 (H1N1) virus in various age groups after the second epidemic wave.

Over 950 randomly selected sera from various regional bacteriological laboratories, collected in October 1979, were assayed for the presence of haemagglutination-inhibition antibodies to current influenza strains. It was shown that in contrast to the previous year (1978), most age groups had significant levels of antibodies to the A/USSR influenza variant. In October 1978 only children, adolescents, and adults born between 1931 and 1950 had such antibodies. As there was little laboratory evidence of A/USSR infections in other age groups than among children and adolescents, we conclude that the majority of these infections must have been inapparent or generally mild.

Adolescent↗
PubMed1979

Antibodies to the strain-specific and cross-reactive determinants of the haemagglutinin of influenza H3N2 viruses. 1. Preparation of antibodies and in vitro studies.

The serological analysis of antibodies to the haemagglutinin (HA) of influenza A viruses of the Hong Kong (H3N2) subtype is described, using haemagglutination-inhibition, immuno-double-diffusion and single-radial-diffusion techniques. By cross-absorption of antisera to purified HA antigens, different populations of antibody molecules were obtained, which are designated strain-specific and cross-reactive and characterized in terms of their antigenic specificities for HA antigens of the homologous and antigenically variant H3N2 viruses. A narrowly strain-specific population of antibodies (SS"HK) was obtained as the residual antibody in antiserum to A/Hong Kong/1/68 HA after absorption with the closely related A/England/42/72 virus, whilst a contrasting broadly cross-reactive population (CR'HK) was obtained by absorption of the anti-A/Hong Kong/1/68 HA serum with the more distantly related strain A/Victoria/3/75 and eluting the cross-reactive antibodies from the absorbing virus. Similarly, specific and cross-reactive antibodies were derived from antiserum to A/Victoria/3/75 HA antigen by absorption with A/Hong Kong/1/68 virus. Single-radial-diffusion tests were performed, involving sequential application of different antibody preparations in the same wells in immunoplates containing intact virus particles. The cross-reactive and strain-specific antibodies differed in their property of mutual interference of attachment ot antigen. The results suggested that the cross-reactive antigenic determinants on the HA subunit may be located closer to the distal end of the molecule than the strain-specific determinants. Further tests employing single-radial-diffusion showed that there are more cross-reactive than strain-specific sites available for antibody in the intact virus particle. The strain-specific antibodies also gave higher haemagglutination-inhibition titres per microgram IgG than the cross-reactive antibodies.

Antibodies, Viral↗
PubMed1979

Surveillance of the antibody status to current influenza strains in the Norwegian population. 1: Method of serum sampling and evaluation of the A/USSR/77 (H1N1) impact in various age groups in 1978.

Every autumn approximately 900 randomly selected sera from various regional bacteriological laboratories are received at the NIPH and assayed for the presence of haemagglutination-inhibition antibodies to current influenza strains. After three years of preliminary investigations the system is now working successfully. It is possible, in retrospect, to assess the impact of various influenza strains in different age groups and regions of the country. In particular, after the reappearance of the H1N1 subtype (the "Russian influenza") in Europe in January 1978, the sera collected in Norway during a 3-week period in October 1978 clearly showed that those under the age of 25 years, and especially teenagers between 13 and 16 years of age, were struck by this virus. This was unexpected since there was hardly any influenza morbidity associated with this "new" strain recorded in the winter of 1978.

Adolescent↗
PubMed1978

Single-radial-complement-fixation: a new immunodiffusion technique. Assay of the antibody response to the type-specific antigens of influenza virus in post-infection human sera.

A new immunodiffusion technique in agarose gel for the quantification of complement-fixing antibodies is described. The test involves the incorporation of antigen and complement in a primary agarose gel. Heat-inactivated serum samples are allowed to diffuse radially from wells overnight at 4 degrees C. A secondary gel, containing antibody-coated sheep erythrocytes, is layered on top of the first gel and the system is incubated for 45 min at 37 degrees C. Where complement is fixed, i.e., around wells with positive serum samples, zones of unlysed cells appear. There is a straight line relationship between zone areas so produced and log(2) serum titres obtained with the conventional complement fixation test. The method appears to be applicable to a variety of antigens. It has been found suitable for bacterial and viral antigens. The test can also be reversed, thus allowing the quantification of diffusible antigens in a gel containing immune serum and complement. This paper describes in detail the use of this method as a diagnostic tool for the assay of complement-fixing antibodies to the type-specific antigens of influenza virus in paired human sera.

Antigen-Antibody Reactions↗
PubMed1976

Reactivity of rabbit IgG-fragments in single-radial-immunodiffusion.

The previously described method of assaying the antibody response to influenza virus by single-radial-immunodiffusion is based on the formation of opalescent zones when immune sera are allowed to diffuse into gels containing large amount of purified influenza virus. The zones are not thought to be the result of immune aggregates of virus particles and antibody since the virus is immobile in the gel and the average distance between two neighbouring particles is approximately 50 times the virus diameter. The present study investigates how different rabbit IgG-fragments react in this type of test. It was found that IgG, F(ab')2 and reduced (monovalent) IgG gave rise to distinct zones of opalescence. Fab', on the other hand, produced weak and hazy zones which could not be quantitated with any accuracy. We conclude that the most likely mechanism responsible for the zones is a light-scattering effect caused by antibodies attached to the viral surface and that the quality of the opalescence to some extent seems to be dependent on the Fc-fragment.

Animals↗
PubMed1976

Antigenic variants of influenza A virus obtained in vitro.

The aim of this study was to investigate antigenic "drift" in the haemagglutinin and neuraminidase antigens of influenza A virus in vitro under immunological pressure. Variants of the "Asian" influenza strains A/England/12/64 (H2N2) and A/Tokyo/3/67 (H2N2) were isolated in the allantois-on-shell system in the presence of homologous postinfection ferret sera. For each of these two viruses three generations of variants were isolated and characterized. It was found that the successive antigenic variants of A/Eng/12/64 did not resemble A/Tokyo/3/67. Thus it is probable that the pathway of antigenic drift in vitro was not the same as that which occurred in nature during the evolution of A/Tokyo/3/67 from A/Eng/12/64. In addition, A/Tokyo/3/67, which was the last strain to be prevalent before the A/Hong Kong subtype appeared, underwent significant antigenic drift from "junior" to "senior" variants. This finding did not support the concept that, when antigenic drift occurs, resulting in the appearence of viruses with new haemagglutinin antigen subtypes, the previously prevalent strain has no capacity for further antigenic drift. The study did not result in the production of strains that were identifiable as "bridging" viruses between the H2 and H3 haemagglutinin subtypes. The present paper includes the first report of antigenic variation in the neuraminidase antigens of influenza A viruses occurring in vitro under immunological pressure.

Antigens, Viral↗
PubMedDate not supplied

Rapid quality evaluation of hybridomas using ELISPOT and cell-ELISA techniques.

We have used the ELISPOT assay in combination with ELISA procedures for rapid evaluation of properties of three different murine hybridoma cell lines, 104-I, -B and -G, secreting IgG1 kappa monoclonal antibodies against a 104-mer synthetic peptide from the C-terminal part of HIV-1 p24. By conventional ELISA we obtained data suggesting that the three monoclonal antibodies had different affinities. By cell-ELISA we found that the IgG1 kappa secretion rate varied between cells (4,000 to 14,000 antibody molecules/cell/min), and ELISPOT showed that only 4-5% of 104-I cells gave antigen-specific spots, indicating a cell population with diverse properties. We recommend that the ELISPOT and cell-ELISA techniques should be used routinely to supplement conventional ELISA procedures for rapid evaluation of hybridoma properties.

Animals↗
PubMedDate not supplied

Systemic and local immune responses after parenteral influenza vaccination in juvenile diabetic patients and healthy controls: results from a pilot study.

Diabetes patients suffer frequent complications and some excess mortality after influenza virus infection. Despite widespread agreement that diabetic patients should be routinely vaccinated against influenza, some reports claim that diabetics have a poor immune response to influenza vaccine. We have performed a pilot study to examine the humoral immune response of juvenile diabetics and matched healthy controls vaccinated with inactivated trivalent influenza vaccine. By enzyme-linked immunospot assay we found that both groups had comparable magnitude and kinetics of influenza-specific antibody secreting cell response. The influenza-specific antibody response in both serum and oral fluid were similar for both groups, and also showing a kinetic profile in accordance with our earlier data for healthy adults. Our study did not detect a difference in the humoral immune response between juvenile diabetics and healthy controls.

Adolescent↗
PubMedDate not supplied

The next influenza pandemic: lessons from Hong Kong, 1997.

The 1997 Hong Kong outbreak of an avian influenzalike virus, with 18 proven human cases, many severe or fatal, highlighted the challenges of novel influenza viruses. Lessons from this episode can improve international and national planning for influenza pandemics in seven areas: expanded international commitment to first responses to pandemic threats; surveillance for influenza in key densely populated areas with large live-animal markets; new, economical diagnostic tests not based on eggs; contingency procedures for diagnostic work with highly pathogenic viruses where biocontainment laboratories do not exist; ability of health facilities in developing nations to communicate electronically, nationally and internationally; licenses for new vaccine production methods; and improved equity in supply of pharmaceutical products, as well as availability of basic health services, during a global influenza crisis. The Hong Kong epidemic also underscores the need for national committees and country-specific pandemic plans.

Animals↗