Diagnosis of iron deficiency anemia in a rural population of children. Relative usefulness of serum ferritin, red cell protoporphyrin, red cell indices, and transferrin saturation determinations.

The diagnostic usefulness in iron deficiency anemia of serum ferritin, red cell protoporphyrin (Epp), mean corpuscular volume, mean corpuscular hemoglobin (MCH), and transferrin saturation measurements has been studied in a population of 294 children aged 1 to 6 yr. Of the children studied 19% had hemoglobin below 11 g/dl. Iron deficiency, diagnosed by at least two abnormal independent laboratory parameters, was the cause of anemia in all except two cases.

EA rosette formation: a simple means to increase sensitivity of the antiglobulin test in patients with anti red cell antibodies.

Erythrocyte antibody (EA) rosette formation with the Fc-receptor on the K-562 erythro-myeloid cell line was employed for the detection of subagglutinating amounts of Ig molecules bound to red cells. The sensitivity of this method exceeds that of the conventional direct and indirect antiglobulin tests without any alteration of the incubation media or pretreatment of red cells. The increased sensitivity did not diminish the specificity of the test, which can detect IgG, IgM and complement as well.

The in vitro sensitivity of leukemic and normal leukocytes to hydrocortisone induced cytolysis.

A marked sensitivity of CLL lymphocytes to hydrocortisone in vitro was demonstrated in each of the 25 patients tested. The sensitivity was manifested by the eventual lysis of the affected cells. Malignant lymphocytes from 8 out of 14 ALL patients were found also to be in vitro sensitive, whereas CML cells, AML cells, normal BM cells, thymocytes, peripheral blood lymphocytes, and polymorphonuclear cells were resistant.

Continuous production of monoclonal rheumatoid factor by EBV-transformed lymphocytes.

Human B lymphocytes are immortalized by Epstein-Barr virus (EBV, ref. 1). The virus can be used to establish lymphoblastoid cell lines that produce and actively secrete specific antibodies.

Human prothymocytes. Membrane properties, differentiation patterns, glucocorticoid sensitivity, and ultrastructural features.

Thymic precursor cells (prothymocytes) comprise a large proportion of the fetal thymic cell population, but are less frequently encountered in the postnatal thymus, where they compose < 1% of the entire population. In the present study we attempted to characterize a number of properties of the prothymocytes obtained from human fetal thymic tissues after depletion of the E-rosette thymocyes on a Ficoll-Hypaque gradient. The prothymocytes are larger than the thymocytes and show a different nuclear chromatin pattern.