Lymphocyte subsets in normal bone marrow

Bone marrow aspirates and biopsies from ten normal donors were stained directly with monoclonal antibodies specific for lymphocyte, monocyte, and myeloid antigens, and were analyzed by flow cytometry. To avoid cell loss, lymphocytes were not specifically isolated prior to staining. T cells comprised 46% of aspirate lymphocytes and 22% of biopsy lymphocytes. Further, the Leu-3:Leu-2 ratio of bone marrow T cells was below 1.0. B cells comprised 8% to 11% of bone marrow lymphocytes in both aspirates and biopsies, and there was a substantial percentage of cells in the lymphocyte window that was negative for all B and T cell markers. The lymphocyte window had very little myeloid contamination; however, when the myeloid window was examined, staining was greater than 90%.     

Subcutaneous recombinant granulocyte-macrophage colony-stimulating factor used as a single agent and in an alternating regimen with azidothymidine in leukopenic patients with severe human immunodeficiency virus infection [see comments]

We investigated the effects of recombinant human granulocyte-macrophage colony-stimulating factor (rGM-CSF) administered by the subcutaneous route, first alone and then alternating with azidothymidine (AZT), in leukopenic patients with severe human immunodeficiency virus (HIV) infection. Ten patients with acquired immunodeficiency syndrome (AIDS) or related disorders, five of whom could not tolerate conventional doses of AZT, were administered rGM-CSF subcutaneously for 12 days. They then were administered an alternating regimen using AZT for 1 week, followed by 5 days of subcutaneous rGM-CSF and 2 days without any medication. During the initial 12 days of GM-CSF administration, there was an increase in the mean white blood cell (WBC) value. In addition, rGM-CSF stimulated circulating monocytes as evidenced by an increase in superoxide anion production and expression of surface HLA-DR antigen. However, at the same time rGM-CSF increased the serum HIV p24 antigen in each of the six evaluable patients from 189 x/divided by 2.02 pg/mL (geometric mean x/divided by SEM) at entry to 375 x/divided by 2.11 pg/mL (P less than .05). During the subsequent period of alternating AZT and rGM-CSF treatment, serum HIV p24 antigen fell below the day 14 value in most patients, particularly after the weeks of AZT administration. The mean T4 cell value increased in patients who had not previously received AZT, but generally did not change in those who had prior AZT exposure. Hematologic toxicity appeared to be somewhat reduced compared with continuous full-dose AZT therapy, and two patients with previous AZT hematologic toxicity tolerated this alternating regimen for 25 weeks. Additional regimens simultaneously combining these two agents are worth exploring.     

Methodology of in vivo human sodium MR imaging at 1.5 T

The methodology of sodium-23 (Na-23) imaging is reported in relationship to the physiological factors that determine the chemical environment of the Na-23 nucleus. Contrast resolution is given as a function of imaging time and spatial resolution. Data showing the optimal relaxation time for sodium imaging are given, and the linear quantitative relationship between sodium concentration and voxel intensity for our imaging system is confirmed. The major problem facing in vivo sodium imaging is the ability to differentiate intracellular sodium from extracellular sodium. The sodium in blood serum (extracellular) and packed red blood cells (intracellular) both exhibit biexponential T2 decay. These results indicate that T2 measurements alone will be insufficient for discriminating extracellular from intracellular sodium. Instead, other methods based on the underlying physiological properties of in vivo sodium imaging, such as the diffusion coefficient, will be necessary to truly separate extracellular from intracellular sodium.