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Biomedical subjects

R W Newman

Publications and source records attributed to R W Newman.

34 records · Page 2Linked to original sources
PubMed1977

The use of transportable single-radial-diffusion immunoplates in seroepidemiological studies of influenza in the Gambia. The occurrence and persistence of antibody to influenza A/Hong Kong/68 (H3N2) virus in selected inhabitants of two rural villages.

Seroepidemiological studies of influenza in the Gambia were made using transportable single-radial-diffusion immunoplates containing A/Hong Kong/68 (H3N2) virus as antigen. The frequency and durability of antibody so detected in selected residents of two Gambian villages (Manduar and Kafuta) are described. Transportable immunoplates were found to be an effective method for the serological surveillance of influenza and to be applicable in studies in remote areas where laboratory facilities may not be available. Results indicated that infection with influenza was widespread in Manduar residents on several occasions between 1968 and 1974 and that reinfection with A/Hong Kong/68 virus or its antigenic variants occurred frequently. Serum levels of antibodies to the haemagglutinin and neuraminidase antigens of the A/Hong Kong/68 virus often persisted for only a short time (mean half-life about 28 days), particularly after first infections. Antibody persistence increased following repeated reinfection. No precise explanation can be offered at present for the relatively short persistence of antibodies in Gambians. Possible reasons include genetic and environmental factors, depressed immunological reactivity associated with concurrent infection (notably parasitic diseases), and unusually high rates of synthesis and catabolism of immunoglobulins. The value of transportable immunoplates for serological surveys and for accurate assessment of antibody persistence is discussed.

Adolescent↗
PubMed1975

Temperature regulation training in a cooling environment.

Twelve young men were given biofeedback training to enable them to increase finger temperature at will. They were dressed in warm clothing, including gloves, and placed six at a time in an environmental chamber at 7 degrees C for three hours daily for eight work days. Each was to attempt six rewarmings per session. Finger temperature was presented to the subject on a multipoint recorder. Data from 554 attempts were analyzed. A training effect was not noted, but successful rewarmings were present from the start. The 12 subjects varied considerably in ability to rewarm, from 89% to 28% successes. They were divided into the most and least consistent who, nevertheless, remained over 10 degrees C above air temperature. These performances were compared with another group wearing identical, or even much more insulative, handwear under roughly comparable conditions but without voluntary rewarming; the advantage of periodic feedback rewarming to maintain finger temperature in such conditions was obvious.

Body Temperature↗
PubMed1975

A single-radial-immunodiffusion technique for the assay of influenza haemagglutinin antigen. Proposals for an assay method for the haemagglutinin content of influenza vaccines.

Single-radial-diffusion techniques are proposed as possible alternatives to tests based on agglutination of erythrocytes for the assay of the haemagglutinin content of influenza vaccines. Two test procedures (microtest and macrotest) and the use of reference reagents to assay vaccines using these tests are described. The two tests are of similar reproducibility and accuracy but the macrotest is technically simpler to perform and results of assays may be obtained more rapidly.

Antigens, Viral↗
PubMed1969

Immunological relationships between the neuraminidases of human and animal influenza viruses.

The neuraminidases of 3 human A2 virus strains-A2/Singapore/1/57, A2/England/76/66 and A2/Hong Kong/1/68-were compared immunologically with those of a number of influenza A virus strains of animal origin (14 avian, 2 equine and 1 porcine). The methods used were enzyme-inhibition tests and immuno-double-diffusion. In enzyme-inhibition tests, the neuraminidases of the A2/57 and A2/66 viruses cross-reacted with those of Turkey/Wisconsin/66, Turkey/Massachusetts/65 and Duck/Italy/574/66 viruses. The enzyme of the Hong Kong variant had a wider spectrum of cross-reactions than did those of the A2/57 and A2/66 viruses. No cross-reaction was detected with Turkey/Massachusetts/65 but the A2/Hong Kong enzyme showed major antigenic similarities with the enzymes of Turkey/Wisconsin/66 and Duck/Italy/574/66 and Duck/Germany/1998/68 viruses. Minor cross-reactions were also detected between the A2/Hong Kong enzyme and those of fowl plague virus, virus "N", Duck/England/56 and Swine/Cambridge/39.The cross-reactions between the enzymes of A2/Hong Kong and Turkey/Wisconsin/66 were confirmed by immunoprecipitin tests. Those between A2/Hong Kong and fowl plague virus, virus "N", Duck/England/56 and Swine/Cambridge/39 could not be confirmed by immunoprecipitation.The finding of antigenic similarities between the enzymes of human and avian influenza A viruses may be of importance in considering the origin of the new antigenic variants of influenza A virus which appear in man.

Animals↗
PubMedDate not supplied

Compatible instrumentation for intraoperative MRI: expanding resources.

Steadfast progress has been made from biopsy to surgery with interventional MRI (iMRI). Such image-guided interventions require specialized instrumentation due to the unusual elements of the MR environment. Suppliers/manufacturers of MR-compatible instrumentation were few in 1994, but now there are more than 50. We present fundamental issues of MR compatibility and a list of known suppliers/manufacturers.

Humans↗
PubMedDate not supplied

Application of an improved single-radial-immunodiffusion technique for the assay of haemagglutinin antigen content of whole virus and subunit influenza vaccines.

An improved single-radial-diffusion technique for the assay of influenza haemagglutinin antigen is described. The modified method enables the results of assays of antigen to be obtained more rapidly and with greater precision than previously. The use of immunoplates containing varied, preselected concentrations of antihaemagglutinin antibody allows accurate assays to be performed over a wide range of antigen concentration. In tests on "whole virus" antigen preparations it was found that the ratio between haemagglutination titre (iu/ml) and haemagglutinin antigen activity (microgram/ml) determined by single-radial-diffusion was relatively constant for antigens containing a given strain but showed variation between strains (range 16.5 to 26.8 iu/microgram HA activity). For the subunit vaccines examined this ratio showed a large degree of variation (range 1.4 to 16.6 iu/microgram HA activity) and in general was considerably lower than for whole virus antigens. It was concluded that single-radial-diffusion may be of value for assays of the haemagglutinin concentration of both "whole virus" vaccines and subunit vaccines. The data presented suggest that, in the event of antigenic drift, it may be possible to use the existing reference anti-haemagglutinin serum to assay a variant strain of influenza virus.

Antibodies, Viral↗
PubMedDate not supplied

The assay of influenza virus structural antigens in vaccines by rocket immunoelectrophoresis.

The internally situated influenza virus structural antigens (matrix and nucleoprotein) and the glycoprotein hemagglutinin were assayed using rocket immunoelectrophoresis or single radial diffusion following disruption of purified virus with 1% w/v sodium sarcosyl detergent. Electrophoresis was carried out for 1-4 h in 0.05 M barbitone buffer at pH 8.6. The potency estimations of HA and M activity were similar for the two methods for bivalent beta-propiolactone inactivated whole virus vaccines.

Antigens, Viral↗
PubMedDate not supplied

Strain-specificity of antibody to haemagglutinin following inactivated A/port chalmers/1/73 vaccine in man: evidence for a paradoxical strain-specific antibody response.

An analysis was carried out of the anti-haemagglutinin antibody responses in adult human recipients of inactivated whole virus A/Port Chalmers/1/73 (H3N2) vaccine using single radial diffusion combined with antibody adsorption techniques to determine antibody specificity. Antibody was characterised as cross-reactive (i.e. directed against antigenic determinants of haemagglutinin which are common for viruses within the H3 subtype) or strain-specific. Strain-specific antibodies for the vaccine strain and also for A/Hong Kong/68(H3N2) virus were assayed. A high proportion of vaccinees developed antibody of the cross-reactive specificity. The titre and frequency of such antibody increased with vaccine dose (100 iu to 1600 iu per dose). Many individuals developed strain-specific in addition to cross-reactive antibodies. A notable finding was that in 70% of vaccinees who developed strain-specific antibody, this was a paradoxical response directed against the strain specific determinant of A/Hong Kong/68 virus (the first number of the H3 subtype). Only 30% developed strain-specific antibody to the haemagglutinin of the vaccine strain. The percentage of vaccinees developing strain-specific antibodies to the vaccine strain was not significantly increased by increasing the dose of vaccine to 1600 iu. A second dose of A/Port Chalmers/73 vaccine administered approximately one year after the first dose only slightly increased the percentage with A/Port Chalmers strain-specific antibody.

Antibodies, Viral↗