bluuebunny/crossref_metadata_2025_split huggingface dataset:
Erythroid-specific processing of human beta spectrin I pre-mRNA
Authors: Chu ZL , Wickrema A , Krantz SB , Winkelmann JC 
Published: October 2019

Abstract
Erythroid cells express a unique form of beta spectrin I as a result of tissue-specific alternative pre-mRNA processing. Nonerythroid cells that express the beta spectrin I gene include four additional exons at the 3′ end of the mature transcript, leading to elongation of the carboxyl terminus of the protein. The nonerythroid beta spectrin I isoform is not present in the red blood cell membrane skeleton; the erythroid isoform is not detected in other cell types. Therefore, developing erythroid cells acquire this tissue-specific pre-mRNA processing activity during differentiation. In the present study, we investigated the developmental timing of erythroid-specific pre-mRNA processing in human erythroid precursors. Partially purified human peripheral blood burst forming uniterythroid (BFU-E) cells were grown in culture for 5 to 12 days. beta Spectrin I mRNA transcripts were analyzed at different time points by S1 nuclease mapping. The processing of beta spectrin I transcripts was found to be exclusively erythroid from day 5 onward, indicating that erythroid-specific processing is not linked temporally to assembly of the mature erythroid membrane skeleton. Human erythroleukemia (HEL) cells had both erythroid and nonerythroid transcripts, indicating that both processing patterns can coexist. Induction of erythroid differentiation in HEL cells using hemin resulted in a partial switch toward the erythroid processing pattern of beta spectrin I transcripts. Using a genomic S1 probe that spans the erythroid polyadenylation signal, we found that a substantial portion of the transcripts detected by the erythroid cDNA S1 probe (in both cultured BFU-E and HEL cells) is incompletely processed pre-mRNA precursors. Poly(A) RNA selection before S1 analysis showed that the unprocessed transcripts are not polyadenylated. We conclude that (1) erythroid-specific pre-mRNA processing activity is present early in erythroid differentiation; (2) beta spectrin I transcripts that are unprocessed at the 3′ end accumulate, awaiting either erythroid or nonerythroid processing pathways, from which observation we infer that the regulated alternative pathways are both inefficient; and (3) HEL cells offer a human cell culture model in which to study the balance between the two pre-mRNA processing pathways. We speculate that erythroid cells evolved this tissue-specific pre-mRNA processing machinery for other erythroid genes in addition to beta spectrin I.
Fetal hemoglobin and potassium in isolated transferrin receptor- positive dense sickle reticulocytes
Authors: Franco RS , Barker-Gear R , Miller MA , Williams SM , Joiner CH , Rucknagel DL 
Published: October 2019

Abstract
A subset of sickle cells have an increased density at the reticulocyte stage of development, indicating that they are either abnormally dense upon release from the bone marrow or become dense quickly in the circulation. These cells are of interest because they most likely have severely disrupted cation regulation and a short lifespan. Based on the distribution of fetal hemoglobin (HbF) in the density fractions of sickle red blood cells (RBCs) and in vitro studies of cellular K+ loss, it seems likely that HbF content is an important in vivo determinant of dense cell formation. In this study, we tested the hypothesis that young, dense cells have low HbF content. Sickle RBCs were first separated into light and dense fractions. Reticulocytes were isolated from unfractionated cells and from each density fraction with an immunomagnetic technique directed against transferrin receptors (TfR) and assayed for the percentage of HbF and K+/Hb ratio. TfR+ reticulocytes isolated from unfractionated cells had a much lower HbF content when compared with all the unfractionated RBCs. This is most likely caused by enrichment of F cells because of a longer circulation life span. Heavy TfR+ reticulocytes had a K+/Hb ratio similar to that measured in the entire dense population and contained very low levels of HbF, averaging 2.5% of the level in all RBCs, 11.7% of the level in all TfR+ reticulocytes, and 4.0% of the level in all dense RBCs. These findings suggest that TfR+ dense cells derive predominantly from non-F cells. Furthermore, the amount of HbF in the circulating dense cells suggests that many of these cells do not derive from the TfR+ dense cells.
Treatment of large granular lymphocyte leukemia with oral low-dose methotrexate
Authors: Loughran TP Jr , Kidd PG , Starkebaum G 
Published: October 2019

Abstract
Morbidity and mortality in patients with T large granular lymphocyte (T- LGL) leukemia result from infections acquired during severe neutropenia. Optimum treatment for severe neutropenia remains undefined. We conducted an uncontrolled but prospective study of low- dose oral methotrexate, up to 10 mg/m2 weekly, in 10 patients with this disease. Therapeutic response was assessed by serial clinical evaluations and laboratory determinations including complete blood counts, lymphocyte phenotyping, and T-cell receptor gene rearrangement studies. A partial response was defined as a sustained increase in neutrophil count greater than 500/microL. A complete clinical remission was defined as achievement of a normal complete blood count and CD3+ LGL count. Previous prednisone treatment in eight of these patients had produced one clinical remission and four partial responses; tapering of prednisone in each of these patients resulted in recurrence of severe neutropenia. Five patients in this study received both methotrexate and tapering doses of prednisone. Complete clinical remissions on methotrexate were observed in five patients; an additional patient had a partial response. Molecular analyses of T-cell receptor gene rearrangement could not detect the abnormal clone in three of five patients achieving a complete clinical remission. Two weeks to 4 months of therapy were needed before attaining a neutrophil count greater than 500/microL. Complete and partial responses have been maintained on therapy, with a follow-up period ranging from 1.3 to 9.6 years. Low- dose oral methotrexate therapy is an effective treatment for some patients with LGL leukemia.
Molecular analysis of Polish patients with factor VII deficiency
Authors: Arbini AA , Bodkin D , Lopaciuk S , Bauer KA 
Published: October 2019

Abstract
We analyzed the mutations in patients from 10 Polish kindreds with a bleeding diathesis due to factor VII deficiency. Patients from eight families had plasma levels of factor VII coagulant activity (VII:C) and factor VII antigen (VII:Ag) that were less than 4% of normal. The coding sequence of the factor VII gene was amplified from genomic DNA by polymerase chain reaction (PCR). Sequencing demonstrated a C to T transition at position 10798 resulting in Ala294Val, a G to A transition at 10976 resulting in Arg353Gln, and a single bp deletion at 11125 to 11128 causing a frameshift mutation in the triplet encoding amino acid 404. Homozygosity for the three sequence alterations was confirmed with the restriction enzymes AvaII and MspI and allele specific PCR, respectively. A homozygous patient from a ninth family with levels of VII:C and VII:Ag of 4% and 17%, respectively, had Ala294Val and the frameshift mutation, but not Arg353Gln. Investigation of a homozygous patient from a tenth kindred with VII:C and VII:Ag of 11% and 47%, respectively, demonstrated Ala294Val and Arg353Gln, but not the frameshift mutation. Based on the above data, we conclude that the frameshift mutation in the codon for amino acid 404 is associated with marked reductions in VII:C, Arg353Gln can decrease plasma levels of factor VII in the presence of other mutations in the factor VII gene, and Ala294Val results in a dysfunctional factor VII molecule.
Lymphocyte depletion during treatment with intensive chemotherapy for cancer
Authors: Mackall CL , Fleisher TA , Brown MR , Magrath IT , Shad AT , Horowitz ME , Wexler LH , Adde MA , McClure LL , Gress RE 
Published: October 2019

Abstract
Recently we have observed an increased incidence of opportunistic infections in patients treated with intensive chemotherapy for cancer. Because T-cell depletion is associated with similar clinical events in human immunodeficiency virus infection and after bone marrow transplantation, we have analyzed peripheral blood lymphocyte populations in a series of patients during treatment with intensive chemotherapy for cancer. Although neutrophil, monocyte, and platelet numbers consistently recovered to greater than 50% of pretreatment values after each sequential cycle of therapy, lymphocyte numbers did not recover within the same time period. B cells decreased rapidly from a mean value of 149 +/- 46/mm3 before chemotherapy to 4 +/- 1/mm3 during chemotherapy (P = .01). CD4+ T cells decreased from a mean of 588 +/- 76/mm3 before chemotherapy to 105 +/- 28/mm3 during chemotherapy (P = .0002) and CD8+ T cells decreased from a mean of 382 +/- 41/mm3 before chemotherapy to 150 +/- 46/mm3 during chemotherapy (P = .0009). Natural killer cell numbers did not show significant declines (171 +/- 30/mm3 before, 114 +/- 24/mm3 during, P = .19). Based on the history of opportunistic complications in patients with other disorders who display similar degrees of CD4+ T-cell lymphopenia and preliminary observations in this population, immune incompetence could surface as a dose-limiting toxicity for highly dose-intensive chemotherapy regimens.
Identification of upstream signals regulating interleukin-6 gene expression during in vitro treatment of human B cells with pokeweed mitogen
Authors: Chauhan D , Kharbanda S , Uchiyama H , Urashima M , Fragoso R , Sen J , Kufe DW , Anderson KC 
Published: October 2019

Abstract
The present studies have characterized the regulation of interleukin-6 (IL-6) gene expression during pokeweed mitogen (PWM)-driven human B- cell differentiation. PWM induced an early and transient increase in the expression of immediate-early response genes of the jun/fos leucine zipper family (c-jun, jun B, c-fos, and fos-B). The induction of c-jun mRNA by PWM was concentration dependent. Nuclear run-on assays showed that PWM treatment is associated with an increased rate of c-jun gene transcription. The induction of c-jun mRNA precedes the induction of IL- 6 gene expression and IL-6 secretion by the B cells. c-Jun antisense, but not sense, oligodeoxynucleotide (ODN) significantly decreases PWM- related B-cell (1) proliferation; (2) IL-6 mRNA induction; (3) IL-6 secretion; and (4) nuclear extract binding to AP-1 in electrophoretic mobility shift assay. In contrast, c-Fos anti-sense ODN did not effect either IL-6 mRNA induction or IL-6 secretion triggered in B cells by PWM. The results further show activation of c-Raf-1 kinase in PWM- treated B cells. Raf-1 acts upstream to mitogen-activated protein (MAP) kinase; therefore, studies were performed to assay for MAP kinase activation in these cells. The results show an increase in phosphorylation of myelin basic protein (MBP) and c-Jun “Y” peptide in PWM-treated B cells. Taken together, these findings suggest that PWM is able to initiate an intracytoplasmic signaling cascade in normal human splenic B cells, which, at least in part, involves serine/threonine protein kinases. These results show transient induction of immediate- early response genes in B cells and support a potential role for the c- jun gene product in regulation of IL-6 transcription and secretion.
Structural requirements of platelet chemokines for neutrophil activation
Authors: Yan Z , Zhang J , Holt JC , Stewart GJ , Niewiarowski S , Poncz M 
Published: October 2019

Abstract
Using recombinantly expressed proteins and synthetic peptides, we examined the structural/functional features of the platelet chemokines, neutrophil-activating peptide-2 (NAP-2) and platelet factor 4 (PF4); that were important in their activation of neutrophils. Previous studies with the chemokine interleukin-8 (IL-8) had shown that the N- terminal region preceding the first cysteine residue was critical in defining neutrophil-activating properties. We examined whether NAP-2 and PF4 had similar structural requirements. In the Ale-glu-leu-arg (AELR) N-terminus of NAP-2, substitution of E or R abolished Ca2+ mobilization and elastase secretion. Unlike the parent molecule PF4, AELR/PF4, the hybrid formed by replacing the N-terminal sequence of PF4 before the first cysteine residue with the homologous sequence of NAP- 2, stimulated Ca2+ mobilization and elastase secretion. Furthermore, the effect of amino acid substitutions in the ELR motif differed from those seen with NAP-2 in that conserved substitutions of E or R in NAP- 2 abolished activity, but only reduced neutrophil activation in the hybrid. These studies show that just as with IL-8, the N-termini of NAP- 2 and PF4 are critical for high-level neutrophil-activating function. Desensitization studies provided information on receptor binding. NAP- 2, which binds almost exclusively to the type 2 IL-8 receptor (IL-8R), did not desensitize neutrophils to activation by IL-8 because IL-8 could bind to and activate via both type 1 and 2 IL-8R. AELR/PF4 appears to bind to both types of receptors because it desensitized neutrophils to NAP-2 activation; but was not desensitized by NAP-2, and because it desensitized to and was desensitized by IL-8. Thus, although NAP-2 and AELR/PF4 share approximately 60% amino acid homology, they have different receptor affinities. Studies were performed to define the role of the C-termini of these platelet chemokines in receptor binding. Heparin and a monoclonal antibody specific for the heparin- binding domain of PF4 both inhibited Ca2+ mobilization and elastase release, further suggesting that the C-terminus of these chemokines is important in receptor binding. Synthetic NAP-2(51–70) failed to mobilize Ca2+, whereas PF4(47-–70) and PF4(58–70) induced Ca2+ mobilization and secretion of elastase at high concentrations. Pertussis toxin inhibited neutrophil activation by 40% to 50%, establishing a role for G-protein-coupled receptors such as the IL-8Rs in activation by the PF4 C-terminal peptides.(ABSTRACT TRUNCATED AT 400 WORDS)
Mast cells cultured from the peripheral blood of normal donors and patients with mastocytosis originate from a CD34+/Fc epsilon RI- cell population
Authors: Rottem M , Okada T , Goff JP , Metcalfe DD 
Published: October 2019

Abstract
Mast cells may be cultured from human peripheral blood in the presence of recombinant human stem cell factor (rhSCF). The characteristics of the cells in peripheral blood that give rise to mast cells are unknown. Because mast cell precursors in human marrow are CD34+, human peripheral blood mononuclear cells from patients with mastocytosis and normal controls were sorted on the basis of CD34 expression and the positive and negative cell populations were cultured in rhSCF, recombinant human interleukin-3 (rhIL-3), or both for 6 weeks. Cell cultures were examined every 2 weeks for total and mast cell number and cell differential using Wright Giemsa and acid toluidine blue stains and antibodies to mast cell tryptase and chymase, cell-associated histamine, and expression of CD34, c-kit, Fc epsilon RI, and Fc gamma RII using flow cytometric analysis. The ultrastructural anatomy of mast cells was examined by electron microscopy. Peripheral blood CD34+ cells cultured in rhSCF with or without rhIL-3 gave rise to cell cultures consisting of greater than 80% mast cells by 6 weeks. CD34+ cells cultured in rhIL-3 alone did not give rise to mast cells, whereas rhIL- 3 plus rhSCF increased the final mast cell number eightfold when compared with cells cultured in rhSCF alone. Mast cells increased concomitantly with a decrease in large undifferentiated mononuclear cells. CD34- cells did not give rise to mast cells. Histamine content per cell at 6 weeks was approximately 5 pg. Electron microscopy of 4- week cultures showed immature mast cells containing predominantly tryptase-positive granules that were either homogeneous or contained lattice structures, partial scroll patterns, or central dense cores and mixtures of vesicles, fine granular material, and particles. The CD34+ population at day 0 expressed Kit (65%) and Fc gamma RII (95%), but not Fc epsilon RI, by fluorescence-activated cell sorter analysis. At 6 weeks, CD34+-derived mast cells exhibited Fc epsilon RI in addition to Kit and Fc gamma RII, and were negative for CD34 antigen. Patients with mastocytosis showed a higher number of mast cells per CD34+ cell cultured compared with normal controls. Thus, the mast cell precursor in human peripheral blood is CD34+/Fc epsilon RI- and gives rise to mast cells in the presence of rhSCF with or without rhIL-3, and the number of mast cells arising per CD34+ cell in culture is greater when the CD34+ cells are obtained from patients with mastocytosis compared with normal subjects.
Characterization of CD34+ peripheral blood cells from healthy adults mobilized by recombinant human granulocyte colony-stimulating factor
Authors: Tjonnfjord GE , Steen R , Evensen SA , Thorsby E , Egeland T 
Published: October 2019

Abstract
Primed peripheral blood hematopoietic stem cells (PBSC) generate and sustain lymphohematopoiesis in myeloablated animals, and recent reports indicate that allogeneic transplantation using PBSC grafts may be feasible in humans. A major concern with the use of PBSC transplants is that permanent engraftment may be limited because of lack of sufficient numbers of primitive progenitor cells in the graft. In the present study, in vitro colony formation and immunophenotype of CD34+ cells in PB of healthy adults during short-term granulocyte colony-stimulating factor (G-CSF) administration were compared with that of CD34+ cells in normal bone marrow (BM). The number of CD34+ cells mobilized to PB peaked at day 4 or 5 of G-CSF administration. The phenotypic profile of CD34+ PB cells showed a substantial increase in the percentage of CD34+CD13+ and CD34+CD33+ cells (myeloid progenitors) and a corresponding decrease in the percentage of CD34+CD10+ and CD34+CD19+ cells (B lymphoid progenitors) compared with CD34+ BM cells. The other subsets studied, including CD34+CD38- and CD34+HLA-DR- cells, were present in both compartments in similar proportions. Furthermore, primed CD34+ PB cells were enriched for colony-forming cells (CFC) and displayed an increased clonogenicity when compared with their counterparts in BM. A comparison between a postulated PBSC graft and an average BM graft is presented, showing that such PBSC grafts will be enriched for CD34+ cells as a whole, CD34+CD33+ cells, and colony- forming cells (CFC), factors which have been shown to correlate to acceleration of hematologic reconstitution and reduction in requirements for supportive care in autografting. Hence, we predict that allogeneic transplantation using G-CSF-primed PBSC grafts will result in a more rapid hematologic reconstitution after myeloablative conditioning than BM grafting. The question of whether PBSC allografting will result in permanent engraftment and clinical benefits as observed in autografting has to be determined in prospective clinical studies.
Effects of in vivo recombinant methionyl human granulocyte colony- stimulating factor on the neutrophil response and peripheral blood colony-forming cells in healthy young and elderly adult volunteers
Authors: Chatta GS , Price TH , Allen RC , Dale DC 
Published: October 2019

Abstract
Recombinant granulocyte colony stimulating factor (G-CSF) was administered daily for 14 days to healthy young (Y) (20 to 30 years) and elderly (O) (70 to 80 years) volunteers to evaluate the effects of age on the neutrophil (polymorphonuclear leukocytes, PMN) responses. Thirty-eight volunteers were randomized to receive 0 micrograms, 30 micrograms, or 300 micrograms per day. Baseline neutrophil counts (ANC), peak ANCs, and the rate of attaining the peak ANC were similar in both age groups at both doses. The peak ANC was increased 5-fold at 30 micrograms and 15-fold at 300 micrograms in both the young and elderly. Daily tests of PMN function, as measured by an automated chemiluminescence system, showed nearly identical responses to several agonists for both age groups. Marrow proliferative activity as reflected by the percentage of cells in the marrow neutrophil mitotic pool also increased similarly for both age groups at both doses. In contrast, there was an age-related change in blood colony formation as measured by the blood CFU-GM assay. Compared with controls at the 30 micrograms dose, mean colony formation was increased 2-fold in the young versus no change in the elderly and at the 300 micrograms dose 24- fold in the young versus 12-fold in the elderly. These studies indicate that neutrophil responses to rhG-CSF are equivalent in healthy young and elderly volunteers but the mobilization of progenitor cells, as measured by the CFU-GM assay appears to differ substantially.
Transfer of the tumor necrosis factor alpha gene into hematopoietic progenitor cells as a model for site-specific cytokine delivery after marrow transplantation
Authors: Kuhr T , Dougherty GJ , Klingemann HG 
Published: October 2019

Abstract
Relapse of leukemia is the major cause of failure after autologous stem cell transplantation due to reinfusion of residual clonogenic cells and the absence of an immune-mediated graft-versus-leukemia effect. To provide an antileukemia effect, immune-activating cytokines have been given to patients after transplantation. Systemic administration of such cytokines early after transplantation is often accompanied by substantial side effects, and it is unknown whether sufficient concentrations reach the sites of residual disease in the marrow. As a method of site-directed immunotherapy provided early after stem cell transplantation, we have tested in a murine model whether (1) marrow can be retrovirally transduced with the tumor necrosis factor alpha (TNF alpha) gene, (2) local production of TNF alpha by marrow cells after transplantation can be achieved, and (3) adverse effects of TNF alpha occurred. Balb/c mice were treated with 5-fluorouracil and bone marrow (BM) was obtained 4 days later. Whole BM was transduced in the presence of interleukin-3 (IL-3), IL-6, and stem cell factor by coculture with the packaging cell line GP+E-86, producing the cDNA for TNF alpha. Irradiated (1,300 cGy) syngeneic recipient mice were given 10(6) transduced BM cells on day 0. Integration of the TNF alpha gene into the host genome was documented by Southern blotting in spleen and BM cells on days 7 and 12 and in BM on day 40 after marrow infusion, but was no longer found on day 90. Messenger RNA for TNF alpha was present on day 12, but could no longer be shown on day 40 or 90. Although no measurable (L929 bioassay) levels of TNF alpha were found in serum of mice who had received TNF alpha transduced marrow, the supernatant of 10(6) unstimulated BM cells obtained 12 days after marrow infusion was found to have 7 pg of TNF alpha compared with 1.8 pg in nontransduced marrow. Mice that had received TNF alpha transduced marrow showed no side effects suggestive of systemic TNF alpha release, and cellularity of the TNF alpha-transduced marrow was not different from control mice that had received unmanipulated marrow or cells transduced with the neomycin resistance gene only. The studies suggest that gene transfer of immune-activating cytokines into hematopoietic cells could be used as a means to achieve their temporary local production early after transplantation by cells located in the BM.