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Biomedical subjects

G W Bird

Publications and source records attributed to G W Bird.

At least 19 recordsLinked to original sources
PubMed1996

A closer look at self-image in male foster care adolescents.

Using the Offer Self-Image Questionnaire, this study attempted to determine the differences between 58 male adolescents in foster care and their peers in the normal population and to establish if there are characteristics of the adolescents' background or foster care experience related to specific domains of self-image. Characteristics from foster care history included number of placements and length of time at the current placement. Individual background characteristics included race, educational achievement, and age. Foster care youths had lower family self-image and emotional health and higher social self-image when compared with the normative population. Lower scores on several domains of self-image were associated with being younger, being white, having lower academic achievement, having more placements, and staying at the current placement for a longer time. The implications of these findings for foster care placement decisions are discussed.

Adolescent↗
PubMed1991

Semi-quantitative assay of D antigen site density by flow cytometric analysis.

This study describes the comparative measurement of D antigen site density using a fluorescent indirect antiglobulin test (FIAT) read by flow cytometry. The test results confirmed the continuum of D antigen strength from weakest D through to R2R2 and also allowed the majority of weak D samples to be adequately distinguished from D-negative samples.

Erythrocytes↗
PubMed1989

Characterization of a neuraminidase from Corynebacterium aquaticum responsible for Th polyagglutination.

Th polyagglutinability is characterized by the agglutination of the red blood cells (RBC) by Arachis hypogaea, Medicago disciformis, Vicia cretica but, in contrast to the T phenomenon, not by Glycine max (Glycine soja). Because Th transformation of RBC has been obtained in vitro, the mechanism of Th polyagglutinability expression has been studied and reproduced experimentally. An enzyme with neuraminidase specificity has been isolated from the culture supernatant of Corynebacterium aquaticum, and further characterized (MW = 55,600 kDa, pH = 5.5, Km = 0.138 microM, Kcat = 0.22 micrograms). Reversely, Th transformation of RBC could be obtained by using other neuraminidases but in very mild conditions of hydrolysis. From our results, it can be concluded that by the release of less than 20 micrograms of sialic acid per 10(10) RBC, Th reactivity can be induced whereas hydrolysis of greater amounts of sialic acid (greater than 20 micrograms/10(10) RBC) give the classical T polyagglutinability.

Blood Group Antigens↗
PubMed1987

Polyagglutination in hospitalized patients: a prospective study.

A hospital population at high risk for red cell polyagglutination was studied prospectively in search for cryptantigen exposure. The patients included in this study suffered from: malignancies, sepsis, direct antiglobulin test (DAT) negative anemias and various combinations of these three. 238 patients were examined, and 18 of these (7.6%) were found to have exposed cryptantigens on their erythrocytes. This is an unexpectedly high percentage. Our findings suggest that cryptantigen exposure on the red cells is a more common phenomenon than previously described, especially when looked for in a carefully chosen population. The red cells of these patients are potentially polyagglutinable, and screening with lectins will ensure their pretransfusion identification and evaluation.

Adult↗
PubMed1987

Tx polyagglutination in three members of one family.

A case of acute haemolytic anaemia is described in a child. Tx polyagglutination of his red cells was observed, but no direct association with the anaemia could be proved. Polyagglutination was suspected because of irregularities in the AB0 blood grouping. Confirmation of the cryptantigen Tx was made when the patient's red cells were tested with lectins including Arachis hypogaea, Glycine soja, and Vicia cretica. Examination of family members showed Tx polyagglutination on the red cells of 2 siblings. The Tx polyagglutination was a transient phenomenon lasting 4-5.5 months, and could have been caused as the result of some unidentified bacterial or viral infection. Guidelines for transfusion therapy are suggested in patients in whom polyagglutination is recognised.

Adolescent↗
PubMed1985

Myelofibrosis, autoimmune haemolytic anaemia and Tn-polyagglutinability.

A patient with myelofibrosis was studied for about four years. During this period he developed autoimmune haemolytic anaemia, a rare complication of myelofibrosis. Furthermore, about two years after the investigation started, his red blood cells, previously normal, became Tn-polyagglutinable, a change known to be due to somatic mutation in haemopoietic stem cells.

Anemia, Hemolytic, Autoimmune↗
PubMed1984

Lectins from Loasaceae.

Extracts of Caiophora coronata or Loasa vulcanica seeds contain a strong lectin for T, Tn, Cad 1, and papain-treated erythrocytes.

Erythrocytes↗