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E S Barrow

Publications and source records attributed to E S Barrow.

15 recordsLinked to original sources
PubMed1980

Identifying carriers of mild haemophilia.

The problems of carrier identification in mild haemophilia were examined by studying a large kindred transmitting VIII:C levels which average 17 u/dl in affected males. Fifteen obligatory carriers and 13 normal women from this kindred were used as reference groups to produce a set of linear discriminants. The utility of these discriminants in identifying carriers of mild haemophilia was compared with that of a similar set of discriminants which had been prepared for use with carriers of severe haemophilia, each set of discriminants being tested against both data bases. It was found that both sets of discriminants had large error rates when applied to the mild data base, and that both had much smaller error rates when applied to the severe data base. This outcome resulted from the greater overlap between the factor VII-related activities of mild carriers and normal women than the overlap of these activities between severe carriers and normal women. Our conclusions were that (i) correct classification of many but not all women from families of mild haemophilia would be difficult, (ii) discriminants prepared using obligatory carriers of severe haemophilia were not more inefficient in mild haemophilia than those prepared using obligatory carriers of mild haemophilia, (iii) a single set of discriminants prepared from reference groups of normal women and obligatory carriers of severe haemophilia may be used for identifying potential carriers of all grades of haemophilia, and (iv), statistically speaking, VIIIR:Ag assays provide a limited amount of information for this purpose.

Age Factors↗
PubMed1980

Factor VIII coagulant antigen in hemophilic plasma: a comparison of five alloantibodies.

Five independent alloantibodies directed to factor VIII coagulant antigen (VIII:CAg) were assessed against normal, von Willebrand's disease, and severe hemophilia A plasmas. Immunoradiometric assays (IRMAs) were developed for each antibody, one of which had arisen "spontaneously" and four in transfused hemophiliacs. The correlations between assays were very high for normal, vWd, and both CRM+ and CRM- hemophiliacs. This suggests that IRMAs maybe developed from almost any reasonably high titered alloantibody and used with confidence in diagnosing CRM- hemophilia A in utero by fetoscopy.

Antibody Specificity↗
PubMed1979

The separation of Willebrand factor from factor VIII-related antigen.

The three activities associated with factor VIII--coagulant (VIII:C), antigenic (VIIIR:Ag), and platelet agglutinating or Willebrand factor (VIIIR:WF)--have been separated by sequential antibody affinity chromatography, utilizing a rabbit antibody to factor VIII and a spontaneous human antibody to VIII:C. Normal plasma differentially lost its factor VIII-related antigen following passage over the rabbit antibody column. Subsequent passage of the VIIIR:Ag-depleted plasma over the human antibody column resulted in the loss of VIII:C activity, with retention of the Willebrand factor activity, antigen being partially recovered from the heterologous antibody column. These experiments demonstrate that it is possible to separate two of the factor VIII activities, VIIIR:Ag and VIIIR:WF, which are usually regarded as properties of a single molecule.

Antibody Affinity↗
PubMed1978

Use of a simple visual assay of Willebrand factor for diagnosis and carrier identification.

A visual assay of factor VIII-related Willebrand factor (VIIIR:WF) is described which utilizes formaldehyde-fixed platelets, end points being read in microflocculation tiles. Four dilutions of a sample can be assessed simultaneously, and the correlation with aggregometric assays is high (r = 0.91). Measurement error is 8.0% for a single assay in triplicate and less than 5% if an assay is repeated three times. The method has been used for 2 years by the coagulation genetics group at Chapel Hill for diagnosing subjects with von Willebrand's disease and assigning genotypes to members of families transmitting this disorder. Its utility in classifying known carriers of haemophilia A has also been examined, both in conjunction with assays of VIII:C and in a three-way test with assays of VIII:C and VIIIR:Ag. As predicted by the Lyon hypothesis, the rate of false negative diagnosis was higher than false positive diagnosis, but the overall rate of misclassification on single plasma samples was 7/51 = 13.7%. The error rate was the same whether discrimination was based upon assays of VIII:C vs. VIIIR:Ag, VIII:C vs. VIIIR:WF, or VIII:C vs. VIIIR:Ag vs VIIIR:WF, the same individuals being misclassified by each method. The observed rate of misclassification was well within the rates reported by others and very similar to our previous experience. We have concluded that this method of assaying VIIIR:WF is highly useful for diagnosing vWd, detecting inhibitors to VIIIR:WF, and examining large numbers of column fractions. It is a useful supplement, although it cannot yet substitute for, assays of VIIIR:Ag in detecting carriers of haemophilia A.

Antigens↗
PubMed1975

Dominant inheritance of hemophilia A in three generations of women.

A bleeding diathesis is described which is phenotypically indistinguishable from hemophilia A and which has been transmitted as a dominant trait in three generations of women in a North Carolina kindred. The abnormal phenotype is characterized by clinical mildness and slightly abnormal clotting time, prothrombin consumption, and partial thromboplastin time. Bleeding time, platelet count, clot retraction, tourniquet test, and prothrombin time are normal. Concentration of factors I, II, V, VII, IX, X, and XII are normal, while factor VIII activity is reduced to 2%-5% of control values. De novo synthesis of factor VIII does not occur after transfusion; factor VIII-related antigen is normal; patients' plasmas aggregate platelets normally in the presence of ristocetin, and a typical protein pattern is seen when a chymotryptic digest of cryoprecipitate of the proband is examined by SDS-polyacrylamide gel electrophoresis. Six possible genetic explanations are entertained. Balanced X-autosomal translocation of hemophilia A heterozygotes has been excluded by cytogenetic analysis of metaphase chromosomes. Classes von Willebrand's disease (vWd) is probably excluded on the basis of the laboratory data, and extreme lyonization of hemophilia A heterozygotes on probabilistic grounds. The genetic possibilities which cannot be excluded include a previously unrecognized variant mutation at the vWd locus, a dominant mutation at the hemophilia A locus on the X chromosome, and dominant mutation at a hypothetical fourth locus involved in factor VIII synthesis and control.

Animals↗
PubMed1973

Factor VIII.

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Alleles↗