Biomedical subjects
H H Gunson
Publications and source records attributed to H H Gunson.
Transfusion medicine: fact and fiction.
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U.K. multicentre study on blood donors for surrogate markers of non-A non-B hepatitis. Part I: Alanine transferase and anti-HBc testing.
Blood samples from 9,215 blood donors in three U.K. centres (North London, Bristol and Manchester) were tested for their alanine aminotransferase (ALT) level and the presence of anti-HBc and anti-HCV. This paper presents the results of the ALT and anti-HBc tests. The prevalence of ALT > 45 IU/l was 3.1% overall (North London 3.06%, Bristol 4.56% and Manchester 1.97%). Manchester results were skewed by the methodology used for ALT measurement, highlighting the need for standard test methods. Anti-HBc was detected using the Wellcome enzyme-immunosorbent assay (EIA) and confirmatory testing was performed using a radioimmunoassay (RIA) and the Corecell haemagglutination assay. Repeat reactive rates were 0.9, 0.79 and 0.94% for North London, Bristol and Manchester, respectively, with an overall rate of 0.9%. The confirmed positive rate was 0.73, 0.53 and 0.65% for the three centres with an overall rate of 0.63%. Donors with an ALT > 45 IU/l, or with confirmed anti-HBc, were interviewed with a medical questionnaire for risk factors. The major contributing factors in donors with a raised ALT were alcohol consumption and obesity.
Screening of blood donations for HIV-1 antibody: 1985-1991.
One hundred and ninety HIV-1 antibody positive donors have been detected, out of 14.85 million blood donations screened in the United Kingdom and the Isle of Man, since the start of testing in October 1985 to the end of March 1991. There were 145 men and 45 women, with an overall seropositivity rate of 0.001%. Records for new donors (ie, those donating for the first time) have been kept since February 1986 and 79 out of 1.9 million donations have been seropositive (58 men and 21 women); a rate of 0.004%. One hundred and forty-one (74.2%) of the 190 positive donors were found to have been exposed to a high risk of HIV infection. Twenty-four (13%) denied any exposure other than heterosexual intercourse with partners who were not considered to be at high risk. In six cases the partners were from countries where the main route of transmission is heterosexual. Seven donors (4%) attributed infection to some other cause. Eighteen (9.5%) have been lost to follow-up, are still being investigated or have not yet been interviewed. Combined tests which screen for both HIV-1 and HIV-2 antibodies were introduced in June 1990. The last 2.55 million donations (including 370,000 new donors) have been tested with these kits. One HIV-2 antibody positive donation had been confirmed in a new donor by the end of March 1991.(ABSTRACT TRUNCATED AT 250 WORDS)
Blood transfusion services.
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Bedside blood compatibility testing.
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Comparison of false-positive reactions in direct-binding anti-HIV ELISA using cell lysate or recombinant antigens.
In a 2-year study of false-positive anti-HIV-1 tests in blood donors at Manchester and Lancaster Blood Banks, the reactions associated with a HIV-infected cell lysate antigen were compared with those using recombinant-antigen-based tests. In year 1 (cell lysate test) at Manchester BTS 0.21% of 119.178 donations were repeatedly reactive, compared with 0.53% of 119,004 donations in year 2 (recombinant antigen). Reactive sera were tested at Manchester PHL by three different immunoassays. Referred specimens were classified as anti-HIV positive (95-100% reactive in all the assays), equivocal or negative (negative results in all three immunoassays). Two donors were confirmed to be anti-HIV positive over the 2-year period. Most sera were negative by confirmatory immunoassays in years 1 and 2. In year 1, a study of 60 referred sera with sex- and age-matched controls showed high correlation between a reactive anti-HIV-1 screening test and indeterminate anti-HIV-1 patterns on Western blot showing reactions with HIV gag-coded proteins. In year 2, less than 10% of referred sera were reactive by Western blot, and there was no correlation between a reactive screening anti-HIV test, the strength of signal in the test or a reactive Western blot. Follow-up showed that donors whose sera were reactive in years 1 and 2 by the anti-HIV-1 screening test formed almost two different populations. Four donors with equivocal anti-HIV-1 confirmatory tests had anti-HIV 'envelope' reactions.(ABSTRACT TRUNCATED AT 250 WORDS)
ABC of transfusion. National self-sufficiency in blood and blood products.
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AIDS update.
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HIV antibody screening of blood donations in the United Kingdom.
Routine screening of blood donations for anti-HIV commenced in the UK during October 1985 and by the end of February 1987 approximately 3.7 million donations had been tested. Seventy-two were confirmed anti-HIV positive, i.e. 0.002%. Of the anti-HIV-positive donors interviewed to date, the majority are young homosexual or bisexual men or intravenous drug abusers. Included in the study are data collected on approximately 470,000 donors giving blood for the first time. Twenty of these have been confirmed anti-HIV positive (0.004%), and 19 interviewed have admitted to being in risk categories. In 5 instances a positive anti-HIV donor was found negative on a previous occasion, and in 1 instance the products from the donation led to seroconversion in the recipients. The majority of anti-HIV-positive donors attending for blood donation did so because they did not consider that the self-exclusion categories specified in the leaflet issued to donors applied to them since homosexual activity or drug abuse was not currently being practised.
Reference preparation for assay of anti-D immunoglobulin.
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HLA antigens in polymyalgia rheumatica.
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International collaborative study of assay of anti-D (anti-Rh) immunoglobulin.
An international collaborative study of anti-D assays has been carried out by 21 laboratories in 11 countries. Samples of anti-D immunoglobulin assayed in this study included two dilutions of a preparation used in clinical trials to determine a dose-protection relation, a national standard, commercial clinical preparations and the proposed international reference preparation in coded ampoules. Manual, automated haemagglutination and isotope labelling methods all gave similar relative potencies. Several of these estimates were significantly (P=0.95) heterogeneous and some modifications to improve assay design and procedure are suggested. The coded preparation was shown to be stable and suitable for comparative assays. It was estimated to contain 60 microgram of of anti-D IgG immunoglobulin per ampoule, and 150 i.u./ampoule when assayed against the International Standard for Incomplete Anti-D Blood Typing Serum. Thus for this preparation 1 microgram of IgG anti-D immunoglobulin identical to 2.5 i.u. anti-D antibody. At its 28th meeting the Expert Committee on Biological Standardization of WHO established the preparation 68/419 as the International Reference Preparation of Anti-D Immunoglobulin and assigned to it a potency of 150 i.u. per ampoule. The Preparation has been widely used (with a nominal content of 60 microgram of IgG anti-D immunoglobulin) for control of clinical preparations.
The primary Rho(D) immune response in male volunteers.
After a single antigenic stimulus, not greater than 5.0 ml R2R2 red cells, anti-D was detected in 79% of D-negative volunteers increasing to 88% after subsequent spaced stimuli. The use of repeated antigenic stimuli at 2- or 4-weekly intervals to induce the immune response did not appear to increase the frequency of responders. The results obtained are compared with those of other workers and evidence is presented to suggest that the immunogenicity of red cells from different donors may have a role in determining the frequency of responders with detectable anti-D and is possibly associated with the R2 antigenic complex.
The anti-Rho(D) responses of immunized volunteers following repeated antigenic stimuli.
Twenty-nine Rho(D) negative male volunteers previously immunized with D-positive red cells have received series of antigenic stimuli repeated at intervals of 2 or 4 weeks. Although there is an individual variation in the magnitude of the anti-D response, the levels of anti-D achieved are, in general, higher than those obtained after stimuli spaced at intervals of several months. Moreover, certain volunteers whose plasma was not suitable for inclusion into pools for the preparation of anti-D immunoglobulin after spaced stimuli could donate regularly following the repeated stimuli. Whilst untoward clinical reactions did not occur as a result of the repeated stimuli five volunteers developed unwanted antibodies outside the Rh system and this may be related to the total dose of red cells injected.
Molecular basis of Tn-polyagglutinability.
Spectrophotometric and gas-liquid chromatographic analyses on the carbohydrate moiety of tryptic erythrocyte glycopeptides from persons with Tn-syndrome reveal a selective lowering of the galactose and sialic acid content, the degree being dependent on the percentage of polyagglutinable cells. Alkaline borohydride specifically releases N-acetylgalactosaminitol, and the amount is correlated to the percentage of pathological acetylgalactosaminitol, and the amount is correlated to the percentage of pathological erythrocytes. It is concluded that the alkali-labile carbohydrate chains of Tn-polyagglutinable red cells solely consist of N-acetylgalactosamine linked to serine or threonine. Experiments with heterophile agglutinins whose specificity is known are in line with the above-mentioned results. As judged from SDS-polyacrylamide gel electrophoresis the three major membrane glycoproteins are affected to a different extent by the defect.
An inhibitor to erythrocyte agglutination in bovine albumin preparations.
Three out of 28 commercial preparations of bovine serum albumin have been encountered which have an inhibitory effect on the assay of anti-Rh-o(D) using the Technicon AutoAnalyser. The inhibitory property, which can also be demonstrated by standard manual serological techniques, appears to be directed towards the second stage of the agglutination reaction. An automated screening procedure for bovine serum albumin preparations and some properties of the inhibitor are described.
Studies on glycoproteins and glycopeptides from Tn-polyagglutinable erythrocytes.
Direct evidence for the theory that Tn-polyagglutinable erythrocytes have a deficiency of alkali-labile sialic acid and galactose is gained by analysing the carbohydrate moiety of the tryptic glycopeptides with spectrophotometric methods and gas-liquid chromatography. Alkaline borohydride treatment of these glycopeptides specifically releases N-acetylgalactosaminitol. In addition it is shown that mainly the third and the first membrane glycoprotein are affected by the defect.