Model for the control of potassium transport in PHA-stimulated human blood lymphocytes

Results are reported for studies on the following: lymphocyte plasma-membrane ATP ase; substrate specificity of lymphocyte membrane phosphatase activity; effect of PHA on lymphocyte membrane ATP ase; correlation of K/sup +/ with lymphocyte K/sup +/ concentration; and K/sup +/ efflux, influx, and cell concentration in PHA-treated lymphocytes. (HLW

Quantification of erythroid and granulocytic precursor cells in plateletpheresis residues

Mononuclear cell fractions of human blood and plateletpheresis residues were compared for their content of hemopoietic precursor cells. Erythroid burst-forming units (BFU-E) averaged 560 +- 130 per ml of blood and granulocyte--monocyte colony forming units (CFU-C) averaged 240 +- 90 per ml blood. Estimates based on a blood volume of 7% of body weight indicate that the total blood pools of BFU-E and CFU-C are about 3.5 x 10/sup 6/ and 1.5 x 10/sup 6/ cells respectively. Sequential studies were performed over 3 days following one plateletpheresis in 4 donors. CFU-C and BFU-E approximately doubled between 48 and 72 hours after a plateletpheresis. During this time there was no significant alteration in the percent of null, T or B lymphocytes in blood. Thus, plateletpheresis appears to lead to a mobilization of precursor cells, which results in a transient increase in their concentration in blood. Therefore, pheresis 48 to 72 hours after an initial short-term procedure could harvest much larger numbers of precursor cells. Moreover, such techniques would put blood precursor cell content of plateletpheresis residues within reach of the precursor cell content in the volume of human marrow used for transplantation

Improved histochemical methods for the examination of plastic-embedded human marrow

Improved methods for processing, sectioning, and staining plastic (glycol methacrylate) embedded human marrow biopsies are described. Marrow biopsies processed by this technique were compared with biopsies processed by the conventional paraffin embedding method. The plastic-embedded marrows provide better morphology enhancing diagnostic accuracy, permit assessment of bone as well as marrow, and allow histochemical analysis of biopsy specimen. Special stains including naphtol AS-D chloroacetate esterase, periodic acid Schiff (PAS), reticulin, and iron have been modified so that they are suitable for undecalcified, two microns thick, plastic-embedded human marrow biopsies