PMN heterogeneity: long-term stability of fluorescent membrane potential responses to the chemoattractant N-formyl-methionyl-leucyl- phenylalanine in healthy adults and correlation with respiratory burst activity

Polymorphonuclear neutrophils (PMNs) were isolated from 24 healthy adults 20 to 61 years of age and the proportion of cells that demonstrated depolarization responses to the synthetic chemotaxin N- formyl-methionyl-leucyl-phenylalanine (FMLP) were enumerated using the lipophilic fluorescent cyanine dye 3,3'-di-pentyl-oxacarbocyanine [di-O- C(5)(3)] and flow cytometry. The membrane potential responses were correlated to the cells' respiratory burst capabilities as measured by nitroblue tetrazolium (NBT) reduction and/or superoxide production in response to FMLP; 40.2% +/- 15.1% (mean +/- SD) of cells depolarized to FMLP. The mean SE for duplicate determinations 1 hour apart was 3.8% (range 0.4% to 13.6%, n = 15). There was no correlation between the percentage of depolarizing PMNs and the yield of cells, the percentage of immature cells, or the circulating WBC count. There was no difference in the average age of men (34.9 +/- 9.9 years, n = 11) v women (33.8 +/- 8.5, n = 13) (mean +/- SD) studied, or in the percentage of depolarizing PMNs when men and women were compared (42.2 +/- 10.6% v 43.1 +/- 13.3%, respectively). However, there was a significant increase in the percentage of depolarizing PMNs with increasing age of women (r = .61, P less than .025) but not men (r = .03, P greater than .05). Analysis of variance revealed significantly greater person-to-person variability in the membrane potential response than in day-to-day variability in the same person (P less than .0005). The percentage of depolarizing PMNs in response to FMLP was significantly correlated with the percentage of NBT-positive cells from both purified PMNs and from whole blood (r = .849, P less than .0005, r = .857, P less than .05, respectively), and with the amount of superoxide produced, expressed as a percentage of that amount produced by cytochalasin B (cyto-B)-pretreated cells (r = .565, P less than .01). The data indicate that PMNs from healthy adults demonstrate a heterogeneous membrane potential response to the chemotaxin FMLP that correlates with the cells' oxidative responsiveness and that intersubject differences can be detected. In addition, the proportion of responsive PMNs increases with increasing age in women.     

Cutaneous lymphoblastic lymphoma with pre-B markers

Two children with cutaneous convoluted lymphoblastic lymphoma are reported. Malignant cells from both patients contained cytoplasmic Mu heavy chains characteristic of pre-B-cells and expressed CALLA and la antigens as well. Most cases of convoluted lymphoblastic lymphoma are T- cell-derived neoplasms. The non-T, non-B phenotype found in these two children demonstrates that histology does not necessarily predict immunophenotype. The association of the pre-B phenotype with cutaneous lymphoma has not been previously reported, but may represent a unique clinical-histopathologic-immunologic entity that occurs in young children.     

Improved results of treatment of adult acute lymphoblastic leukemia

We designed a treatment program to improve the outcome for adults with acute lymphoblastic leukemia (ALL). Treatment included a remission- induction phase followed by intensive alternating cycles of non-cross- resistant chemotherapy and prolonged oral maintenance therapy. Eighty- one consecutive previously untreated patients were entered on this study. Ninety-four percent of patients entered complete remission. A Kaplan-Meier analysis predicts that 53% +/- 9% (SEM) of patients in remission will remain free of disease at 3 years. Neither age, sex, WBC count, nor immunophenotype had a significant effect on remission duration. This program of intensive cyclical chemotherapy has improved the disease-free survival of patients with adult ALL.     

Basophils (Bsp-1+) derive from the leukemic clone in human myeloid leukemias involving the chromosome breakpoint 9q34

The monoclonal antibody (MoAb) Bsp-1 was used to purify basophilic cells from leukemic blood of five patients with Philadelphia chromosome (Ph') positive chronic myeloid leukemia (CML) and two patients with acute myeloid leukemia (AML) characterized by the chromosomal translocation t(6;9)(p23;q34). When cultured, Bsp-1 positive cells from all CML and AML patients showed the same clonal karyotype changes observed in diagnostic buffy coat preparations, indicating that the basophilic cells were of leukemic origin. In contrast, T lymphocytes from four of five CML patients cultured in the presence of interleukin- 2 (IL-2) showed a normal karyotype and were therefore not derived from the leukemic clone. Bsp-1 staining correlated with toluidine blue- positive basophils in chronic phase CML and with toluidine blue- negative blast cells expressing an immature myeloid phenotype in blast crisis CML and AML. Chromosome in situ hybridization showed that the ABL oncogene was translocated from chromosome 9 to chromosome 22 in the CML patients but remained on chromosome 9 in the AML patients. These results indicate that the breakpoint at 9q34 in CML is 5' of ABL, whereas the breakpoint at 9q34 in AML is 3' of ABL. Field inversion gel electrophoresis showed that the 9q34 breakpoint was not within 200 kb 3' of ABL in one of the AML patients, nor was there any rearrangement of the PIM oncogene locus at 6p21.     

Human CD34+ fetal liver stem cells differentiate to T cells in a mouse thymic microenvironment

Hematopoietic stem cells differentiate in the thymus to T cells along precisely defined intermediates. This process is thymic epithelium dependent and involves cytokines and cell-cell interactions between thymic stroma and T-cell precursors. Here we report that highly purified human CD34++ fetal liver stem cells differentiate to mature T cells, when seeded into isolated fetal thymic lobes of severe combined immunodeficient mice, and subsequently cultured in vitro. The human stem cells differentiate sequentially into CD4+CD8-CD3-, CD4+CD8+CD3-, CD4+CD8+CD3+, and finally, CD4+CD8-CD3+4 and CD4-CD8+CD3++ cells. Phenotypic analysis for additional maturation markers showed that these CD4 and CD8 single-positive thymocytes are fully maturate cells. By immunochemistry, human HLA-DR+ cells with a dendritic morphology could be detected. This novel chimeric human-mouse fetal thymus organ culture offers a tool to study human T-cell ontogeny in vitro and is a rapid and reliable test method for T-cell precursor activity of cultured or transfected human stem cells.     

Racial variation in the blood-cerebrospinal fluid barrier of normal children

Conclusion The normal bromide permeability quotient variation of the negro covers a distinctly lower range than that of the white.Financed through Child Neurology Research by the Friedsam Foundation. This is a preliminary report. The full report including complete tabulations and critical analysis of data will appear in the volume of collected reports of Child Neurology Research soon to be published.