bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phagocytosis of Plasmodium falciparum-infected human red blood cells by human monocytes: involvement of immune and nonimmune determinants and dependence on parasite developmental stage
Authors: Turrini F , Ginsburg H , Bussolino F , Pescarmona GP , Serra MV , Arese P 
Published: October 2019

Abstract
The stage-dependent phagocytosis of Plasmodium falciparum-infected erythrocytes (IRBC) opsonized with nonimmune serum has been investigated. An average of 2.9 red blood cell (RBC) harboring ring- forms (RIRBC) and 7.5 RBC infected with trophozoites (TIRBC) or schizonts (SIRBC) were ingested per monocyte, in comparison with 0.8 noninfected RBC (NRBC) or 5 RBC oxidatively damaged with diamide. Abrogation of generation of complement component C3b or blockage of its binding to the phagocyte inhibited phagocytosis of RIRBC by 78% to 95% and of TIRBC by 25% to 50%. Blockage of immunoglobulin G (IgG) binding reduced phagocytosis of both RIRBC and TIRBC nonsignificantly by 14%. Preincubation of monocytes with phosphatidylserine (PS)-containing liposomes reduced phagocytosis of TIRBC by 22%, but had little effect on RIRBC. Residual, noncomplement, non-IgG-, and non-PS-dependent phagocytosis amounted to 6% to 18% of total phagocytosis in RIRBC and TIRBC, respectively. RIRBC bound 2.5 times more protein A and 3.1 times more anti-C3c (a stable derivative of C3b) antibodies, and TIRBC bound 20 times more protein A and 6.8 times more anti-C3c antibodies than NRBC. Phagocytosis of oxidatively damaged RBC and RIRBC are similar, whereas a higher portion of phagocytosis appears to be noncomplement- dependent and PS-suppressible in TIRBC. It is concluded that RIRBC generate recognition signals similar to those present in oxidatively damaged or senescent RBC. Extensive membrane modifications in TIRBC produce additional, hitherto undefined signals that induce much higher and qualitatively distinct phagocytosis.
Spectrin Jendouba: an alpha II/31 spectrin variant that is associated with elliptocytosis and carries a mutation distant from the dimer self- association site
Authors: Alloisio N , Wilmotte R , Morlé L , Baklouti F , Maréchal J , Ducluzeau MT , Denoroy L , Féo C , Forget BG , Kastally R , Delaunay J 
Published: October 2019

Abstract
Spectrin Jendouba (alpha II/31) was found in a Tunisian family. In the heterozygous state, it is associated with asymptomatic elliptocytosis and a minimal defect in spectrin dimer self-association. On partial digestion of spectrin with trypsin, an abnormal cleavage appeared following Lys 788. Peptide and DNA sequencing indicated that the responsible mutation is alpha 791 Asp----Glu (GAC----GAA). As in most alpha-spectrin variants associated with elliptocytosis, the change alters helix 3 of the proposed triple helical model of spectrin structure. Modified helix 3 in repeat alpha 8 is the most distant from the N-terminus of alpha-spectrin in known variants associated with elliptocytosis.
Fetal hemoglobin levels in sickle cell disease and normal individuals are partially controlled by an X-linked gene located at Xp22.2
Authors: Dover GJ , Smith KD , Chang YC , Purvis S , Mays A , Meyers DA , Sheils C , Serjeant G 
Published: October 2019

Abstract
Fetal hemoglobin (Hb F) production in sickle cell (SS) disease and in normal individuals varies over a 20-fold range and is under genetic control. Previous studies suggested that variant Hb F levels might be controlled by genetic loci separate from the beta-globin complex on chromosome 11. Using microscopic radial immunodiffusion and flow cytometric immunofluorescent assays to determine the percentage of F reticulocytes and F cells in SS and nonanemic individuals, we observed that F-cell levels were significantly higher in nonanemic females than males (mean +/- SD, 3.8% +/- 3.2% v 2.7% +/- 2.3%). F-cell production as determined by F reticulocyte levels in SS females was also higher than in SS males (17% +/- 10% v 13% +/- 8%). We tested the hypothesis that F-cell production in both normal and anemic SS individuals was controlled by an X-linked locus with two alleles, high (H) and low (L). Using an algorithm to determine the 99.8% confidence interval of a normal distribution in nonanemic individuals, we estimated that males and females with at least one H allele had greater than 3.3% F cells. Comparisons of male-male or female-female SS sib pairs with discordant F reticulocyte levels distinguished two phenotypes in SS males (L, less than 12%; H, greater than 12%) and three phenotypes in SS females (LL, less than 12%; HL, 12% to 24%, HH greater than 24%). Linkage analysis using polymorphic restriction sites along the X chromosome in eight SS and one AA family localized the F-cell production (FCP) locus to Xp22.2, with a maximum lod score (logarithm of odds of linkage v independent assortment) of 4.6 at a recombination fraction of 0.04.
Leukotriene B4 enhances interleukin-6 (IL-6) production and IL-6 messenger RNA accumulation in human monocytes in vitro: transcriptional and posttranscriptional mechanisms
Authors: Rola-Pleszczynski M , Stankova J 
Published: October 2019

Abstract
Leukotriene B4 (LTB4) is a potent lipid mediator of inflammation, and some of its bioactivities may involve inflammatory cytokines. Moreover, it may participate in myelopoiesis, either directly or via the induction of cytokines and growth factors. When human monocytes were cultured in the presence of graded concentrations of LTB4, significant stimulation of production of bioactive and immunoreactive interleukin-6 (IL-6) was observed. Nanomolar concentrations of LTB4 were optimal and the LTB4 receptor antagonist LY 255283 could block its activity. The omega-oxidation products of LTB4, 20-OH-LTB4 and 20-COOH-LTB4, were only 22% and 2% effective, respectively. LTA4 was also effective in stimulating IL-6 production, but only at micromolar concentrations, whereas 5-HETE and 12-epi-LTB4 were ineffective. The signaling induced by LTB4 did not seem to involve protein kinase C or A, but rather a tyrosine kinase, as suggested by its inhibition with genistein. LTB4 induced an accumulation of IL-6 messenger RNA (mRNA) in treated monocytes with a dose-response similar to that of IL-6 protein production. Whereas IL-6 mRNA half-life in untreated cells was approximately 1 hour, it was extended to 3 hours in LTB4-treated monocytes. Moreover, nuclear transcription of IL-6 mRNA was augmented at 30 minutes by a factor of 5 in LTB4-treated cells. Pretreatment of cells with cyclohexamide before exposure to LTB4 superinduced IL-6 message expression, but partially inhibited the effect of LTB4 on IL-6 mRNA accumulation, suggesting that newly synthesized proteins may be involved in the transcriptional activation of the IL-6 gene by LTB4. These findings constitute a first demonstration that LTB4 stimulates IL- 6 production and that the underlying mechanisms involve both increased IL-6 gene transcription and message stabilization. This may constitute an important mechanism through which rapidly produced mediators may modulate the subsequent production of regulatory or growth-promoting cytokines.
OMA-AML-1: a leukemic myeloid cell line with CD34+ progenitor and CD15+ spontaneously differentiating cell compartments
Authors: Pirruccello SJ , Jackson JD , Lang MS , DeBoer J , Mann S , Crouse D , Vaughan WP , Dicke KA , Sharp JG 
Published: October 2019

Abstract
OMA-AML-1 was established from a patient with acute myelomonocytic (M4) leukemia at fifth relapse when blasts were greater than 85% CD34+, CD15- . Leukemic cells were established in suspension culture and independently grown as subcutaneous tumors in SCID mice. Cells growing in suspension culture underwent differentiation by phenotypic and morphologic criteria. In contrast, cells grown as subcutaneous solid tumors in SCID mice maintained progenitor cell characteristics with high-density CD34 expression and lack of morphologic differentiation. A tendency toward differentiation to CD15+, CD34- cells in vitro and self- renewal of CD34+, CD15- cells in vivo was consistently demonstrated regardless of whether cells were initially grown in vitro or in vivo. The cell line maintains both a CD34+, CD15- progentitor cell pool and a non-overlapping, CD15+, CD34- differentiating cell compartment after more than 1 year in continuous culture. Cell cycle analysis and cloning experiments were consistent with terminal differentiation occurring in the CD15+, CD34- population. The cell line shows concentration- dependent proliferative responses to interleukin (IL)-3, granulocyte- macrophage colony-stimulating factor (GM-CSF), and IL-6, but not to granulocyte CSF (G-CSF). OMA-AML-1 appears to mimic several features of normal myeloid hematopoiesis and should prove useful for the study of normal and malignant myeloid differentiation.
Crossreacting human lymphoma idiotypes
Authors: Rudders RA , Levin A , Jespersen D , Zacks J , Delellis R , Ranger A , Krontiris T 
Published: October 2019

Abstract
We have examined an unselected series of 72 lymphomas of diverse histologies with a panel of mouse monoclonal antibodies specific for human B-lymphoma-derived Ig idiotypes (anti-ids) to determine the nature and extent of id/anti-id crossreactivity. The anti-id antibodies were prepared from Ig isolated from seven follicular center cell lymphomas by heterohybridoma technique. Thirty-six of 75 individual anti-ids obtained in this manner were further selected based on their reactivity with highly restricted or private idiotypic determinants. Twelve of the 72 (17%) lymphoma biopsies reacted with one or more of the 36 anti-ids that detect private determinants. A pool consisting of five individual antibodies would have detected 11 of the 12 crossreacting tumors. Staining of tumor cell populations was homogeneous in the positive cases, suggesting uniform idiotype expression. If there was a segregated staining pattern, it was generally related to the presence of CD3+ T cells in the section. These follicular center cell-derived anti-ids cross-reacted with follicular center cell tumors of all histologic grades with frequencies ranging from 13% to 50%. The structural basis for the crossreactivity of our lymphoma-derived private anti-ids is as yet not known. However, the reactivity of certain anti-ids with both kappa- and lambda-expressing tumors suggests a biased use of V gene segments in these crossreactive clones that is probably related to the VH gene. These data suggest the possibility that lymphoma may develop in a highly restricted pool of normal differentiated B cells or in B-cell subsets that express a limited repertoire of unmutated VH gene segments.
Stimulation of phosphoinositol turnover and protein kinase C activation by granulocyte-macrophage colony-stimulating factor in HL-60 cells
Authors: Nishimura M , Kaku K , Azuno Y , Okafuji K , Inoue Y , Kaneko T 
Published: October 2019

Abstract
Phosphoinositol turnover, diacylglycerol generation, protein kinase C (PK-C) activity, and intracellular cyclic nucleotides were studied in an established human leukemia cell line, HL-60, in response to one of the hematopoietic cytokines, granulocyte-macrophage colony-stimulating factor (GM-CSF). Continuous exposure of HL-60 cells to GM-CSF induced the cell differentiation that was evaluated by the nitroblue tetrazolium (NBT) reducing activity. GM-CSF also exhibited a proliferative effect on HL-60 cells. GM-CSF at 1 nmol/L, an optimal concentration for cell growth and cell differentiation, induced significant changes in the intracellular inositoltriphosphate (IP3). Diacylglycerol generation was also stimulated by GM-CSF treatment. GM- CSF increased the membrane PK-C activity by 10-fold of the control, whereas no measurable change in cyclic nucleotides was observed. These data indicated that phosphoinositol turnover and the activation of PK-C were included in the GM-CSF signal transducing pathway in HL-60 cell. Phosphoinositol response leading to PK-C activation may act as a trigger signal of cell differentiation by GM-CSF.
Multiple Rh messenger RNA isoforms are produced by alternative splicing
Authors: Le Van Kim C , Cherif-Zahar B , Raynal V , Mouro I , Lopez M , Cartron JP , Colin Y 
Published: October 2019

Abstract
Three Rh-related cDNAs have been isolated from a human bone marrow cDNA library and by polymerase chain reaction (PCR) amplification of human bone marrow and erythroblast mRNAs. They potentially encode a family of Rh protein isoforms that exhibit several unexpected structural properties as compared with the Rh polypeptide encoded by the cDNA clone identified previously. These modifications include several peptide deletions, the predicted alteration of Rh protein topology within the cell membrane, variations in the number and surface exposition of cysteine residues, and the generation of new C-terminal polypeptide segments caused by frameshift mutations. The four Rh mRNAs now described correspond to different splicing isoforms transcribed from the same Rh gene, and all exist in the same cell lineage (erythroid). Moreover, PCR experiments indicated that at least three of these RNA species exist in reticulocytes from donors with different commonly expressed Rh phenotypes. Although the translated proteins have not yet been characterized, these results suggest that the two genes at the RH locus may direct the synthesis of several protein species possibly corresponding to different Rh antigenic variants.
A c-kit ligand, recombinant human stem cell factor, mediates reversible expansion of multiple CD34+ colony-forming cell types in blood and marrow of baboons
Authors: Andrews RG , Bartelmez SH , Knitter GH , Myerson D , Bernstein ID , Appelbaum FR , Zsebo KM 
Published: October 2019

Abstract
The ligand for the human c-kit, recombinant human stem cell factor (SCF), was administered to baboons at doses of 200, 100, 50, 25, and 10 micrograms/kg/d. SCF induced a dose-dependent expansion of hematopoietic colony-forming cells (CFC) of multiple types in both blood and marrow, including colony-forming unit (CFU) granulocyte- monocyte, burst-forming unit-erythroid, CFU-MIX, and high proliferative potential-CFC. These changes were associated with a dose-dependent leukocytosis, involving all leukocyte lineages, a reticulocytosis, and increases in marrow cellularity. At 200 micrograms/kg/d of SCF, CFC in blood were increased 10-fold to greater than 100-fold. This correlated with an increased frequency of CD34+ cells in blood. The frequency of CFC in blood approached that of marrow in some animals. These changes were reversed within 7 to 14 days of stopping SCF. The results of these studies suggest a role for the c-kit ligand in stimulating the expansion of multiple CFC types in blood and marrow for potential therapeutic purposes.
Identification of a point mutation in factor XIII A subunit deficiency
Authors: Board P , Coggan M , Miloszewski K 
Published: October 2019

Abstract
Oligonucleotide primers have been designed for the amplification of all 15 exons of the human coagulation factor XIII A subunit gene. Each exon and its intron flanking regions has been amplified and sequenced from a patient with severe A subunit deficiency. A single G to A transition in the last base of exon 14 has been identified in the homozygous proband and in his heterozygous parents. The mutation would result in the substitution 681 Arg to His in the mature protein product. However, because the mutation is at a splice junction, the deficiency may result from a defect in pre-messenger RNA splicing.
Defective transport as a mechanism of acquired resistance to methotrexate in patients with acute lymphocytic leukemia
Authors: Trippett T , Schlemmer S , Elisseyeff Y , Goker E , Wachter M , Steinherz P , Tan C , Berman E , Wright JE , Rosowsky A 
Published: October 2019

Abstract
Although the mechanisms of resistance to methotrexate (MTX) are known in experimental tumors made resistant to this drug, little information is available regarding acquired resistance to MTX in patients. A competitive displacement assay using the fluorescent lysine analogue of MTX, N-(4-amino-4-deoxy-N10-methylpteroyl)-N epsilon-(4′-fluorescein- thiocarbamyl)-L-lysine (PT430), was developed as a sensitive method of detection of transport resistance to MTX in cell lines, as well as in blast cells from patients with leukemia. Rapid uptake of PT430 at high concentrations (20 mumol/L) in leukemic blasts resulted in achievement of steady-state levels within 2 hours. Subsequent incubation with the folate antagonists, MTX and trimetrexate (TMTX), which differ in the mode of carrier transport, produced characteristic patterns of PT430 displacement. Flow cytometric analysis of the mean fluorescence intensity in the human CCRF-CEM T-cell lymphoblastic leukemia cell line and its MTX-resistant subline clearly identified the presence of transport deficiency in the resistant subline. Analysis of blasts from 17 patients with leukemia, nine with no prior chemotherapy and eight previously treated with chemotherapy, found evidence of MTX transport resistance in two of the four patients who were treated with MTX and considered to be clinically resistant to the drug. The finding that blast cells of some patients with leukemia considered clinically resistant to MTX is due to decreased MTX transport has important implications for clinical use of this drug and for new drug development.
Bone marrow stromal fibroblasts secrete interleukin-6 and granulocyte- macrophage colony-stimulating factor in the absence of inflammatory stimulation: demonstration by serum-free bioassay, enzyme-linked immunosorbent assay, and reverse transcriptase polymerase chain reaction
Authors: Guba SC , Sartor CI , Gottschalk LR , Jing YH , Mulligan T , Emerson SG 
Published: October 2019

Abstract
Bone marrow (BM) stromal fibroblasts produce hematopoietic growth factors (HGFs) in response to inflammatory mediators such as tumor necrosis factor-alpha or interleukin-1 alpha (IL-1 alpha). In the absence of such inflammatory stimuli, production of HGFs by BM stromal cells has been problematic and controversial. In vivo, however, basal hematopoiesis maintains blood counts within a normal homeostatic range even in the absence of inflammation, and HGFs are required for progenitor cell differentiation in vitro. To better ascertain the contribution of BM stromal fibroblasts to basal hematopoiesis, we therefore studied HGF production in quiescent BM stromal fibroblasts by three sensitive assays: serum-free bioassay, enzyme-linked immunosorbent assay, and reverse transcriptase polymerase chain reaction. Stromal fibroblasts were cultured in the presence or absence of normal human serum to determine if serum factor(s) present in the noninflammatory (basal) state induce secretion of HGFs. Human serum was found to induce or enhance transcription and secretion of granulocyte- macrophage colony-stimulating factor (GM-CSF) and enhance secretion of constitutively expressed IL-6. In contrast, no secretion of either granulocyte-CSF (G-CSF) or IL-3 was found. These data indicate that factors in normal human serum are active in enhancing GM-CSF and IL-6 production by stromal fibroblasts and suggest that these growth factors contribute to the maintainance of normal, basal hematopoiesis in vivo.
Effects of human stem cell factor (c-kit ligand) on proliferation of myeloid leukemia cells: heterogeneity in response and synergy with other hematopoietic growth factors
Authors: Pietsch T , Kyas U , Steffens U , Yakisan E , Hadam MR , Ludwig WD , Zsebo K , Welte K 
Published: October 2019

Abstract
A novel hematopoietic growth factor, the stem cell factor (SCF), for primitive hematopoietic progenitor cells has recently been purified and its gene has been cloned. In this study we tested the mitogenic activity of recombinant human SCF on myeloid leukemia cells as well as the expression of its receptor. We have investigated the proliferation of 31 myeloid leukemia cell lines as well as fresh myeloid leukemic blasts from 17 patients in a 72-hour 3H-thymidine uptake assay in the presence of various concentrations of recombinant human (rh) SCF alone or in combination with saturating concentrations of granulocyte- macrophage colony-stimulating factor (GM-CSF), G-CSF, M-CSF, interleukin-3 (IL-3), or erythropoietin (EPO). Only five of 31 lines, but fresh leukemic blasts from 12 of 17 patients with acute myeloid leukemia (AML), significantly responded to SCF. The responding cell lines were of the acute promyelocytic, chronic myeloid, megakaryoblastic, and erythroleukemia origin, the responding blast preparations of all French-American-British subtypes. Synergistic activities of SCF were found with G-CSF, GM-CSF, EPO, and IL-3. To determine the SCF binding sites on leukemic cells, we used 125I- radiolabeled SCF in Scatchard analysis and cross-linking studies. The leukemic cell lines responding to SCF expressed from 2,300 up to 29,000 binding sites per cell. The SCF receptor expression was downregulated in vitro by the presence of its ligand. Cross-linking studies demonstrated a 150-Kd SCF receptor on the surface of all responding myeloid leukemias. This study suggests that SCF may be an important factor for the growth of myeloid leukemia cells, either as a direct stimulus or as a synergistic factor for other cytokines. Furthermore, using polymerase chain reaction analysis of total RNA from the myeloid leukemia lines, we found expression of SCF-mRNA in 17 of 30 lines, suggesting autocrine mechanisms in the growth of a subgroup of leukemic cells by coexpression of SCF and its receptor.
Quantification of a novel dense granule protein (granulophysin) in platelets of patients with dense granule storage pool deficiency
Authors: Shalev A , Michaud G , Israels SJ , McNicol A , Singhroy S , McMillan EM , White JG , Witkop CJ , Nichols WL , Greenberg AH 
Published: October 2019

Abstract
An antigen-capture sandwich enzyme-linked immunosorbent assay (ELISA) was developed for a novel protein granulophysin, a constituent of the platelet dense granule (DG) membrane and used to characterize patients with dense granule storage pool deficiency (delta-SPD). The assay uses two monoclonal antibodies against the protein, one of which is conjugated to peroxidase. Purified DGs, an enriched source of the protein, were used for the standard curve. Granulophysin levels were only low in forms of delta-SPD associated with albinism. Granulophysin levels in platelet homogenates of 30 patients with the Hermansky-Pudlak syndrome form of delta-SPD were 1/4 to 1/5 of levels in controls or obligate heterozygotes. Two patients with the Chediak-Higashi form of delta-SPD syndrome also had markedly reduced levels of granulophysin. Patients with other forms of delta-SPD had normal levels of granulophysin. Two sisters with delta-SPD in one family had normal granulophysin present in empty dense granule membrane vesicles. Three members of another family with delta-SPD had low DG counts but normal granulophysin levels, indicating that in this group the level of granulophysin was maintained despite the reduction in granule formation. Thus, granulophysin quantitation facilitates characterization of delta-SPD patients and may provide clues to the nature of defective granules in delta-SPD subtypes.