bluuebunny/crossref_metadata_2025_split huggingface dataset:
Specific repression of granulocyte-macrophage and granulocyte colony- stimulating factor gene expression in interleukin-1-stimulated endothelial cells with antisense oligodeoxynucleotides
Authors: Segal GM , Smith TD , Heinrich MC , Ey FS , Bagby GC 
Published: October 2019

Abstract
Antisense oligodeoxynucleotides (ODNs) have been used to effect the specific inhibition of cellular gene expression. We have evaluated the application of this approach to the inhibition of interleukin-1 (IL-1)- induced granulocyte-macrophage colony-stimulating factor (GM-CSF) and granulocyte colony-stimulating factor (G-CSF) expression in cultured human umbilical vein endothelial cells. Antisense ODNs or control ODNs (sense ODNs or missense ODNs containing random base substitutions) were added to cultures of endothelial cells, the cells were induced with IL- 1 alpha, and the conditioned media were assayed for GM-CSF and G-CSF by quantitative bioassays and for immunoreactive GM-CSF by enzyme immunoassay. Antisense ODNs complementary to the first 15 or 18 bases of the translation start sites of GM-CSF or G-CSF mRNAs inhibited, in a concentration-dependent fashion, the IL-1-stimulated expression of the corresponding factor, but did not affect expression of the other factor. Control ODNs did not affect GM-CSF or G-CSF expression. Exposure to a GM-CSF antisense ODN, but not a control ODN, substantially reduced cytoplasmic GM-CSF mRNA levels in IL-1-stimulated endothelial cells. Neither ODN affected levels of endothelial leukocyte adhesion molecule (ELAM)1 or glyceraldehyde-3-phosphate dehydrogenase mRNAs. We conclude that antisense ODNs complementary to the translation start sites of GM-CSF or G-CSF mRNAs inhibit expression of the corresponding factor in a sequence-specific fashion and this effect is mediated, at least in part, by reduction in the cytoplasmic level of the targeted mRNA. Moreover, IL-1-induced GM-CSF or G-CSF expression does not depend on expression of the other factor.
Accelerated programmed cell death (apoptosis) in erythroid precursors of patients with severe beta-thalassemia (Cooley's anemia) [see comments]
Authors: Yuan J , Angelucci E , Lucarelli G , Aljurf M , Snyder LM , Kiefer CR , Ma L , Schrier SL 
Published: October 2019

Abstract
The profound and life-threatening anemia in patients with Cooley's anemia is ascribed primarily to intramedullary hemolysis (ineffective erythropoiesis), the cause of which is obscure. Based on prior morphologic data showing nuclear abnormalities, we hypothesized that accelerated apoptosis could occur in these erythroid precursors. The highly successful bone marrow (BM) transplantation program for patients with Cooley's anemia provided us with a unique opportunity to test this hypothesis. We obtained pretransplantation BM aspiration samples from patients undergoing BM transplantation in Pesaro, Italy and from their allogeneic donors. The erythroid precursors were isolated using ficoll sedimentation and then panning selecting fro CD45- cells. Cytospin and Giemsa staining showed that the separation provided greater than 90% erythroblasts. Five million of these erythroblasts were lysed and their DNA was isolated. There were obvious ladder patterns of DNA breakdown products in beta-thalassemia major samples, with less occurring in beta- thalassemia trait. Normal individuals showed only a slight smear of breakdown of DNA. These results indicate there is enhanced apoptosis in the erythroblasts in the BMs of Cooley's anemia patients. This finding might partially explain why most of these erythroblasts never survive to become mature erythrocytes.
Structure and expression of the RH locus in the Rh-deficiency syndrome
Authors: Cherif-Zahar B , Raynal V , Le Van Kim C , D'Ambrosio AM , Bailly P , Cartron JP , Colin Y 
Published: October 2019

Abstract
Red blood cell deficiency of Rh proteins is associated with morphologic and functional abnormalities of erythrocytes and with a chronic hemolytic anemia of varying severity. Rh-deficiency may be the result of homozygosity either for a silent allele at the RH locus (Rhnull amorph type) or for a recessive inhibitor gene(s) at an autosomal locus unlinked to RH locus (Rhnull regulator and Rhmod). In this report, we investigated the RH locus structure of Rh-deficient individuals by Southern analysis using cDNA and exon-specific probes deduced from the recent cloning of Rh genes (CcEe and D). As expected from family studies indicating that Rhmod and Rhnull regulator individuals are unable to express Rh antigens but are able to convey functional Rh genes from one generation to another, no alteration of the Rh genes was detected in these variants. Although Rhnull of the amorph type arose by inheritance of a pair of silent alleles at the RH locus, the general organization of the unique CcEe gene in the genome of the particular individual under examination was apparently normal and indistinguishable from a Rh-negative chromosome. More surprisingly, no mutation could be detected by sequencing the polymerase chain reaction (PCR)-amplified reticulocyte mRNAs, suggesting that the RH locus of this patient might be altered in its transcriptional activity. Through hybridization with exon-specific probes, we were also able to determine the zygosity for the D gene in DNA samples from individuals of known genotypes; using this approach, we found that Rhnull regulator variants could be either of the DD, Dd, or dd genotypes. These findings suggest that the postulated inhibitor gene(s) can negatively suppress the RH locus expression from chromosomes carrying either one or two of the Rh genes.
Allogeneic bone marrow transplantation for 93 patients with myelodysplastic syndrome
Authors: Anderson JE , Appelbaum FR , Fisher LD , Schoch G , Shulman H , Anasetti C , Bensinger WI , Bryant E , Buckner CD , Doney K 
Published: October 2019

Abstract
We treated 93 patients with myelodysplastic syndrome using cyclophosphamide and either total body irradiation (n = 88) or busulfan (n = 5) followed by marrow transplantation. Sixty-five marrow donors were genotypically HLA-identical siblings and 28 were other family members or unrelated donors. Before transplantation all patients had either severe neutropenia or thrombocytopenia or had greater than 5% blasts in the marrow or peripheral blood. The probabilities of disease- free survival, relapse, and non-relapse mortality at 4 years were 41%, 28%, and 43%, respectively. Multivariate analysis revealed that younger age and shorter disease duration were significantly associated with improved disease-free survival and decreased non-relapse mortality. Relapse was seen only in patients with excess blasts at the time of transplantation (51% at 4 years). Patients younger than age 40 and without excess blasts had a 4-year disease-free survival of 62%. This study confirms that allogeneic marrow transplantation can cure some patients with myelodysplasia. Because of the favorable outcome in younger patients without excess blasts, we recommend that transplantation be considered early for patients younger than age 40, before disease progression or development of life-threatening cytopenias. For older patients and those with excess blasts, changes in the transplant procedure will be necessary to improve outcome.
Purification and characterization of heterogeneous pluripotent hematopoietic stem cell populations expressing high levels of c-kit receptor
Authors: Orlic D , Fischer R , Nishikawa S , Nienhuis AW , Bodine DM 
Published: October 2019

Abstract
Mouse pluripotent hematopoietic stem cells (PHSC) were fractionated based on size and density using counterflow centrifugal elutriation (CCE). These heterogeneous PHSC populations were further enriched by subtraction of cells with lineage-specific markers (Lin-) followed by positive sorting for c-kit expression. The cells were characterized for their functional and biochemical properties. We defined a subpopulation of c-kit-positive cells that expressed high numbers of c-kit receptors (c-kitBR). One hundred c-kitBR cells from either low- or higher-density fractions were sufficient to repopulate the lymphohematopoietic system in WBB6F1-W/Wv (W/Wv) recipients, whereas no PHSC were found in cells with low (c-kitDULL) or no (c-kitNEG) c-kit expression. Lin- c-kitBR cells were separated into RhoDULL and RhoBR subsets based on their ability to efflux rhodamine 123 (Rho). The PHSC were concentrated in Lin- c-kitBR RhoDULL cells and the number of Lin- c-kitBR RhoBR cells correlated directly with the number of day 12 colony-forming unit- spleen (CFU-S12) in each fraction. We were not able to enrich further for PHSC using monoclonal antibodies to the cell-surface markers AA4.1 or CD4, which have been used by others to isolate PHSC. The small, low- density Lin- c-kitBR subset contained PHSC and few CFU-S12. This enabled us to assay PHSC for expression of the flk-2 gene, which encodes a tyrosine kinase receptor present on fetal liver PHSC. Purified RNA from the low-density Lin- c-kitBR subset did not contain flk-2 mRNA. We suggest that AA4.1, CD4 and flk-2 are expressed as stage- specific markers on PHSC in cell cycle.
Autoantibodies against the platelet glycoproteins (GP) IIb/IIIa, Ia/IIa, and IV and partial deficiency in GPIV in a patient with a bleeding disorder and a defective platelet collagen interaction
Authors: Beer JH , Rabaglio M , Berchtold P , von Felten A , Clemetson KJ , Tsakiris DA , Kehrel B , Brandenberger S 
Published: October 2019

Abstract
To evaluate the physiologic importance of the different collagen receptors on platelets, we screened 806 patients admitted to the hospital because of hemorrhagic diathesis for eventual laboratory evidence of a pathologic platelet collagen interaction, and found 5 patients with an isolated deficiency in collagen-induced platelet aggregation. Four of these five patients had a partial defect, one had a complete defect. The structural and functional analysis of the platelets from the patient with a complete defect showed a deficiency in glycoprotein (GP) IV and autoantibodies against GPIIb/IIIa, GPIa/IIa, and GPIV. Patient plasma had only a minimal effect on normal control platelets and Naka-negative platelets. The analyses of the defect in the patient and of the data in the literature suggest that a single defect may not result in clinical bleeding (GPIV-deficient patients do not bleed), but may become symptomatic in combination with another defect such as the autoantibodies against GPIa/IIa, GPIV, and/or GPIIb/IIIa, all of which are involved in platelet collagen interactions (three of four of our immune thrombocytopenic purpura patients with anti-GPIV and anti-GPIIb/IIIa autoantibodies had a bleeding disorder). We hypothesize that it is the synergism of two abnormalities that results in the defective function, a mechanism that is in agreement with earlier studies on platelet collagen interaction that suggests that a double defect in platelet collagen interactions is required to become clinically apparent.
Lipoxin A4 induces hyperadhesiveness in human endothelial cells for neutrophils
Authors: Lerner R , Heimburger M , Palmblad J 
Published: October 2019

Abstract
Lipoxin A4 (LXA4), but not lipoxin B4, induced in vitro a dose- dependent, slowly emerging hyperadhesiveness in human umbilical vein endothelial cells (HUVEC), leading to a 1.9-fold increase in the binding of neutrophils (polymorphonuclear neutrophil granulocytes [PMN]). The maximal response to LXA4 occurred at 1 nmol/L and after 30 minutes of treatment of HUVEC. These response kinetics were intermediate in comparison with those of fast-acting inducers of HUVEC adhesivity (eg, thrombin, leukotriene B4 [LTB4] or platelet activating factor [PAF]), needing 5 to 15 minutes, or to the slow inducer interleukin-1 (IL-1 beta), which requires hours. The maximal LXA4 effect was slightly lower than that of LTB4 (100 nmol/L) and thrombin (1 U/mL), and less than that of PAF (100 nmol/L) or IL-1 beta (2.5 U/mL) (2.2-, 2.0-, 2.4-, or 13.6-fold increases, respectively). The LXA4 effect was inhibited by the PAF receptor antagonist WEB-2086; however, it could not be blocked by pertussis toxin. LXA4 conferred a slow, sustained increase in HUVEC cytosolic calcium ion concentrations, whereas thrombin did so rapidly and transiently. LXA4 also caused PMN to become hyperadhesive. Thus, this novel effect of LXA4 on HUVEC appears to be associated with endogenous PAF expression and slow increases of cytosolic calcium concentrations but not pertussis- sensitive G proteins.
Autologous IgM, IgA, and complement binding to sickle erythrocytes in vivo. Evidence for the existence of dense sickle cell subsets
Authors: Green GA 
Published: October 2019

Abstract
We have previously reported that sickle erythrocytes sedimenting at high specific density after gradient centrifugation exhibit increased IgG binding in vivo as compared with low-density paired samples. We have performed the present study to determine whether the opsonization of dense sickle cells in vivo could also involve autologous IgM, IgA, and complement. IgA, IgM, and complement binding in vivo to the surface of density-separated sickle erythrocytes was detected by flow cytometric analyses. IgM and complement C3 fragment binding was detected primarily on high-density sickle erythrocytes. With the exception outlined below, IgA binding was detected for all sickle cell fractions that sediment at densities > 1.085 g/mL. IgM, IgA, and complement C3 fragment binding was increased on high-density sickle erythrocytes as compared with low-density paired samples and exceeded that binding to normal erythrocytes by 30% +/- 10% (mean +/- range), 50% +/- 10%, and 41% +/- 5%, respectively. Two-color flow cytometry indicates that high-density sickle cell fractions contain at least two heterogeneous RBC subsets. One is an RBC subset that binds IgA in combination with IgM and C3, and the second subset is devoid of IgA yet binds IgM and C3. These findings indicate that high-density sickle cells exhibit a greater heterogeneity than has been reported in previous studies, which is based on autologous Ig binding in vivo; and suggest that RBC components of this most severely dehydrated sickle cell subpopulation could have heterogeneous origin and pathophysiologic significance. Although the functional role of IgA binding to human RBCs is unclear, our findings that IgM and complement bind to the same high- density sickle cell fractions suggest that both the IgM and the sickle erythrocyte-bound IgG determined in previous studies could mediate the deposition of complement on dense sickle cells in vivo. These findings support the hypotheses that irreversibly sickled cell-enriched high- density sickle RBC subpopulations could be removed from the circulation by erythrocyte phagocytosis that is enhanced by the presence of complement.
Prothymosin alpha gene expression correlates with proliferation, not differentiation, of HL-60 cells
Authors: Smith MR , al-Katib A , Mohammad R , Silverman A , Szabo P , Khilnani S , Kohler W , Nath R , Mutchnick MG 
Published: October 2019

Abstract
Accumulating evidence suggests that prothymosin alpha has an as yet undefined intracellular, perhaps intranuclear, function related to cell proliferation. Prothymosin alpha mRNA and/or peptide levels increase when cells are stimulated to proliferate. Because proliferation and differentiation events are often inversely correlated, we examined prothymosin alpha gene expression during proliferation and differentiation of HL-60 myeloid leukemia cells. Steady-state levels of prothymosin alpha mRNA, which are high in exponentially growing HL-60, decrease within hours after induction of HL-60 to differentiate along the neutrophil pathway with dimethylsulfoxide (DMSO) or along the macrophage lineage with either tetradecanoylphorbol acetate (TPA) or bryostatin 1. The decline in prothymosin alpha mRNA in response to these differentiation signals parallels that of c-myc mRNA under the same conditions. We then determined whether the downregulation of prothymosin alpha and c-myc mRNA were due to differentiation or cessation or proliferation. Recombinant human gamma-interferon induces monocytic differentiation of HL-60, but permits continued proliferation, and, under these conditions, expression of prothymosin alpha, as well as of c-myc, mRNA remains elevated. We conclude that prothymosin alpha and c-myc expression are coregulated in differentiating HL-60 and that their expression correlates with the proliferative state of HL-60 cells, rather than with the differentiated state.
Regulation by alpha 2-antiplasmin and fibrin of the activation of plasminogen with recombinant staphylokinase in plasma
Authors: Silence K , Collen D , Lijnen HR 
Published: October 2019

Abstract
The effects of alpha 2-antiplasmin and fibrin on the activation of plasminogen by recombinant staphylokinase (STAR) were studied in an effort to elucidate further the molecular basis of the fibrin- specificity of this fibrinolytic agent. In purified systems consisting of 1.5 mumol/L intact or low-M(r) plasminogen and 3 mumol/L alpha 2- antiplasmin, at 37 degrees C and in the absence of fibrin, STAR did not induce plasminogen activation and plasmin-alpha 2-antiplasmin complex (PAP) formation. Addition of a purified fibrin clot (30% vol at a concentration of 3 mg/mL) to mixtures containing intact plasminogen caused approximately 40% plasminogen activation within 2 hours, whereas in mixtures containing low-M(r) plasminogen, no activation was observed. In contrast, 10 nmol/L streptokinase (SK) induced 74% to 100% plasminogen activation within 2 hours in mixtures containing either intact or low-M(r) plasminogen, in both the absence and the presence of fibrin. In citrated human plasma in the absence of fibrin, 30 nmol/L STAR did not induce measurable plasminogen activation and PAP formation (< 1.5% within 2 hours), whereas addition of a plasma clot (12% vol) resulted in complete clot lysis and conversion of 19% +/- 8% of the plasminogen to PAP within 2 hours. Addition of a second plasma clot produced 23% +/- 2% additional plasminogen activation. Equipotent concentrations for plasma clot lysis of SK (100 nmol/L) induced 54% +/- 11% plasminogen activation in the absence and 49% +/- 16% in the presence of fibrin. Addition of 50 mmol/L 6-aminohexanoic acid (6-AHA) abolished the effect of fibrin on plasminogen activation with STAR, but not on activation with SK. In alpha 2-antiplasmin-depleted human plasma in the absence of fibrin, 30 nmol/L STAR did not induce fibrinogen breakdown (> 90% residual fibrinogen after 6 hours), whereas 30 nmol/L preformed plasmin-STAR complex induced extensive fibrinogen degradation (70% within 20 minutes). Thus, in the absence of fibrin, alpha 2- antiplasmin inhibits the activation of plasminogen by STAR, by preventing generation of active plasmin-STAR complex. Fibrin stimulates plasminogen activation by STAR via mechanisms involving the lysine- binding sites of plasminogen, probably by facilitating the generation of plasmin-STAR complex and by delaying its inhibition at the clot surface.
Acute promyelocytic leukemia: clinical relevance of two major PML-RAR alpha isoforms and detection of minimal residual disease by retrotranscriptase/polymerase chain reaction to predict relapse
Authors: Huang W , Sun GL , Li XS , Cao Q , Lu Y , Jang GS , Zhang FQ , Chai JR , Wang ZY , Waxman S 
Published: October 2019

Abstract
Recent data have shown that the PML-RAR alpha fusion gene resulting from translocation t(15;17) is a highly reliable molecular marker of acute promyelocytic leukemia (APL). In this study performed on 97 Chinese patients with APL, the retrotranscriptase/polymerase chain reaction (RT/PCR) was used to evaluate the clinical relevance of the long (L) or short (S) PML-RAR alpha fusion mRNA isoforms and to study minimal residual disease during clinical remission (CR). There were more early deaths during the all-trans retinoic acid (ATRA) induction treatment and more relapses within 2 years of CR in the S-type (6 of 19 cases) than in the L-type group (2 of 33 cases) (P < .025). Among 12 cases analyzed before and after the ATRA-induced CR, 9 cases (75%) showed positive RT/PCR, whereas only 3 cases showed a negative result, justifying the need for chemotherapy after ATRA-induced CR. Eleven of 62 APL patients in CR, after ATRA-induced CR and chemotherapy consolidation (follow-up, from 3 to 72 months), showed positive RT/PCR. Five of them relapsed within 1 to 6 months after the positive test; one converted to negative after further chemotherapy; and 5 remained in CR status without further PCR data. However, the latter 5 cases all received further intensive consolidation therapy after the PCR positivity. These results show that a positive RT/PCR of PML-RAR alpha is a sensitive predictor of relapse in APL.
P-selectin mediates spontaneous leukocyte rolling in vivo
Authors: Dore M , Korthuis RJ , Granger DN , Entman ML , Smith CW 
Published: October 2019

Abstract
Rolling represents the initial step leading to leukocyte extravasation from blood vessels during an inflammatory reaction. In vitro studies indicate that P-selectin could be one of the ligands on endothelium involved in the rolling phenomenon, although the molecular determinants responsible for this transient attachment in vivo are still undefined. Our objectives were to develop a blocking monoclonal antibody against canine P-selectin and to use it to investigate the role of P-selectin in leukocyte rolling in vivo using the technique of intravital microscopy. P-selectin was immunoaffinity purified from canine platelets and used for the production of monoclonal antibodies. One of the hybridomas generated, MD6, was shown by enzyme-linked immunosorbent assay and by flow cytometry to bind preferentially to stimulated platelets and to completely prevent binding of stimulated platelets to neutrophils. Visualization of canine mesenteric venules by intravital microscopy showed that administration of MD6 resulted in a marked inhibition in the number of rolling leukocytes (18.96 +/- 9.92 v 156.40 +/- 19.50 leukocytes/min, P < .05; 88.3% +/- 6.0% inhibition). Control antibody MD3 (which recognizes a nonfunctional epitope of canine P- selectin) had no effect on the number of rolling leukocytes or on their rolling velocity. These results show for the first time that P-selectin plays an essential role in leukocyte rolling in vivo, and therefore may be a key participant of the inflammatory response.
Evidence that red blood cell protein p55 may participate in the skeleton-membrane linkage that involves protein 4.1 and glycophorin C
Authors: Alloisio N , Dalla Venezia N , Rana A , Andrabi K , Texier P , Gilsanz F , Cartron JP , Delaunay J , Chishti AH 
Published: October 2019

Abstract
Human erythrocyte p55 is a peripheral membrane protein that contains three distinct domains in its primary structure: an N-terminal domain, an SH3 motif, and a C-terminal guanylate kinase domain. We used naturally mutated red blood cells (RBCs) with primary genetic defects resulting in the absence of protein 4.1 (4.1[-] hereditary elliptocytosis) or glycophorin C (Leach elliptocytosis). The absence of either protein was associated with the absence of p55. On a stoichiometric basis, the reduction in glycophorin C (about 80%) was concomitant to the lack of p55 in RBCs devoid of protein 4.1. Similarly, the reduction of protein 4.1 (about 20%) was equivalent to the absence of p55 in RBCs devoid of glycophorin C. These correlations suggest that p55 is associated, in precise proportions, with the protein 4.1-glycophorin-C complex, linking the skeleton and the membrane. The protein 4.1-glycophorin-C cross-bridge is known to be critically important for the stability and mechanical properties of human RBC plasma membrane. Because isoforms of protein 4.1, glycophorin C, and p55 exist in many tissues, these results provide evidence of a linkage between the skeleton and the membrane that may have implications in many nonerythroid cells.