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Biomedical subjects

P Bealmear

Publications and source records attributed to P Bealmear.

4 recordsLinked to original sources

Isolation of T-cells, B-cells and macrophages by a two-stage adherence procedure.

This communication describes a method to obtain enriched populations of T-cells, B-cells and macrophages. Spleen cells were initially fractionated on nylon wool columns. The nylon wool adherent fraction was removed by mechanical agitation and further separated on the basis of adherence to a coated-plastic surface in the presence of autologous serum. The tissue flask adherent population was removed with the aid of a rubber policeman. The nylon wool non-adherent and the tissue flask non-adherent and adherent fractions were characterized for the presence of cell surface markers, size, and functional activity and were identified as T-cells, B-cells and macrophages, respectively. The two-stage adherence procedure is simple to perform and does not require sophisticated equipment or expensive reagents.

Animals

Age, thymic involution, and circulating thymic hormone activity.

Circulating thymic hormone activity and thymic histology were studied in patients undergoing open heart surgery. Plasma thymic hormone activity was measured using a bioassay based upon thymocyte antigen induction on null mouse lymphocytes. Activity was highest at 15-30 yr of age and declined thereafter, being negligible after the sixth age decade. The age-related decline of circulating thymic hormone activity correlated, in general, with progressive thymic involution. However, hormone activity was detected in plasma from some cases with advanced involution, suggesting that the normal young thymus may have considerable functional reserve.

Adolescent

Circulating thymic-hormone activity in congenital immunodeficiency.

Circulating thymic-hormone activity was assayed by measuring Thy 1-2 antigen induction on null lymphocytes from athymic mice incubated with human plasma or serum. Plasma from 19 normal children aged under 10 had inductive activity equivalent to 10-6-16-2 ng thymopoitin/ml. Plasma from 15 infants were severe combined immuno-deficiency, 2 of whom had appreciable immunoglobulin synthesis, and from 2 infants with DiGeorge syndrome had little or no inductive activity. Successful reconstitution with thymus or bone-marrow grafts and with red-cell infusions (if adenosine-deaminase deficiency is present) was followed by a rise in circulating thymic-hormone activity.

Agammaglobulinemia