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H H Gunson

Publications and source records attributed to H H Gunson.

At least 37 records · Page 2Linked to original sources
PubMed1980

Anti-A haemagglutinins in factor VIII concentrates.

Experimental evidence has been obtained that cryoprecipitation concentrates anti-A in mixtures of group O and group A plasma by a mechanism that does not operate in group O plasma alone. It has been concluded that the anti-A/A polysaccharide complex is less soluble during cryoprecipitation than anti-A immunoglobulin, and this complex dissociates to give free anti-A when the cryoprecipitate is redissolved. From a practical point of view, factor VIII concentrates prepared from cryoprecipitate obtained from single donations of plasma unselected for ABO group contain significantly less anti-A than those prepared from mixing pools of plasma in which partial neutralisation of anti-A has occurred before cryoprecipitation.

ABO Blood-Group System↗
PubMed1980

Evaluation of an AutoAnalyzer method for quantitating anti-A and anti-B haemagglutinins in factor VIII preparations.

The continuous flow principle employed in the Technicon AutoAnalyzer has been adapted for the assay of anti-A and anti-B. The method has an acceptable degree of reproducibility and has been used, principally, for the quantitation of anti-A and anti-B in factor VIII concentrates of intermediate activity. It is, however, a method that can be applied to the assay of these antibodies in serum samples.

ABO Blood-Group System↗
PubMed1980

Collaborative study to recalibrate the International Reference Preparation of Anti-D Immunoglobulin.

A collaborative study involving nine independent assays by eight laboratories has recalibrated the anti-D concentration of the International Reference Preparation of Anti-D Immunoglobulin (68/417) in terms of the International Standard for Anti-Rho (anti-D) Incomplete Blood Typing Serum (64/16). This study was carried out when it was found that 68/419 had been calibrated not against 64/16, as originally intended, but inadvertently against another preparation. Based on the results, a revised rounded off value of 300 IU anti-D per ampoule of 68/419 was assigned by the Expert Committee on Biological Standardisation of WHO at its 30th meeting. Many of the known variables in anti-D quantitation using the AutoAnalyzer were considered in the preparation of the protocol for this study. The remarkably close agreement of the results indicated that the format can be used as an acceptable model for interlaboratory studies in the future.

Calibration↗
PubMed1978

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.

Hemagglutination Tests↗
PubMed1976

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.

Antibody Formation↗
PubMed1976

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.

Antibody Formation↗
PubMed1975

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.

Anemia, Hemolytic↗
PubMed1975

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.

Absorption↗
PubMed1975

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.

Binding Sites, Antibody↗
PubMed1974

The effect of ambient temperature on the anti-D assay using the Auto-Analyzer.

Using the AutoAnalyzer, the percentage agglutination effected by the anti-D antisera studied showed a varied dependence on the ambient temperature over the manifold subsequent to the incubation period at 37 degrees C. This leads to assays which are a function of the ambient temperature. It is suggested that the entry of a relatively large volume of rouleaux-dispersing agent results in an elution of bound antibody to a new position of equilibrium, the shift being dependent on the particular equilibrium constant of the antibody and the rate of its attainment on the ambient temperature. A constant ambient temperature will lead to greater accuracy of anti-D assay.

Autoanalysis↗
PubMed1972

Manipulative and inherent errors in anti-D quantitation using the AutoAnalyzer.

The limits of accuracy for the quantitation of anti-D using the AutoAnalyzer have been reduced from +/- 26% with manually prepared dilutions to +/- 14% using an automatic pipette, as expressed by the 95% confidence limits. The error inherent in the AutoAnalyzer was estimated to contribute +/- 10% to the overall error. Problems associated with the reproducibility of this method for anti-D quantitation have been investigated, namely, the effect of the age of a given test cell, the use of different test cells, loss of sensitivity of the machine over a given day, and the reproducibility of results obtained at different positions on the standard graph.

Analysis of Variance↗