bluuebunny/crossref_metadata_2025_split huggingface dataset:
Expression of the c-myc proto-oncogene in multiple myeloma and chronic lymphocytic leukemia: an in situ analysis
Authors: Greil R , Fasching B , Loidl P , Huber H 
Published: October 2019

Abstract
The c-myc gene plays a pivotal role in mediating the competence state for cell cycle transversion. This biologic role is in contradiction to reports of elevated expression of the gene in multiple myeloma, a tumor with restricted self-renewal capacity. To more clearly define the role of this gene in plasma cells of myeloma patients, c-myc messenger RNA (mRNA) and/or oncoprotein expression were semiquantitatively analyzed on the single cell level in 19 cases of multiple myeloma, among them 1 biclonal case and 1 case with coexistent chronic lymphocytic leukemia (CLL). Performing anti-sense/mRNA in situ hybridization, mature c-myc gene transcripts were detected in 92% (12 of 13) of cases and could definitely be attributed to the plasma cells by our study. The number of Ki 67-positive plasma cells actively passing the cell cycle was less than 1% and independent of c-myc gene expression. However, because the presence of the 152-c-MYC epitope was correlated to extent of marrow plasmacytosis (r = .64; P = .043) and content of plasmablasts (P = .09), the c-myc gene might serve a function different from proliferative activity, but also associated with tumor cell mass. In CLL cells (21 of 22 cases) and their benign counterparts, ie, bone marrow and peripheral blood lymphocytes, the anti-sense/c-myc mRNA hybridization signals remained below the threshold considered as cutpoint between negative and positive. The low amounts of c-myc transcripts were correlated to neither stage of disease (P = .52) nor lymphocyte counts (P = .24). Because the numbers of peripheral blood lymphoma cells were independent of tumor mass and of c-myc gene transcripts expressed, peripheral blood lymphocytosis might more likely reflect homing processes than proliferative activity in CLL.
Hematologic effects of stem cell factor in vivo and in vitro in rodents
Authors: Ulich TR , del Castillo J , Yi ES , Yin S , McNiece I , Yung YP , Zsebo KM 
Published: October 2019

Abstract
Recombinant rat stem cell factor (rrSCF) administered to rats as a single intravenous injection causes a dose-dependent neutrophilia and lymphocytosis as well as the appearance of immature myeloid cells and occasional blast cells in the circulation. Neutrophilia begins at 2 hours, peaks at 4 to 6 hours, and subsides between 12 and 24 hours. Lymphocytosis occurs at 0.5 hours and has subsided by 2 hours. rrSCF- induced neutrophilia and lymphocytosis are abrogated by boiling, demonstrating that endotoxin-contamination of the rrSCF preparation is not responsible for the observed hematologic effects. The bone marrow at 6 hours after injection of rrSCF shows a left-shifted myeloid and erythroid hyperplasia as evidenced by significant increases in the absolute numbers of morphologically recognizable early myeloid and erythroid precursors. A concurrent decrease in the absolute numbers of mature marrow neutrophils is noted, suggesting that the release of marrow neutrophils contributes to the peripheral neutrophilia. After 2 weeks of daily injections of rrSCF, bone marrow smears demonstrate a remarkable mast cell hyperplasia accompanied by a decrease in total marrow cellularity and by a striking erythroid and lymphoid hypoplasia. rrSCF also causes mast cells to appear in the circulation and causes a systemic increase in embryonic connective tissue-type, but not mucosal- type, mast cells. In vitro long-term culture of lineage-depleted mouse bone marrow cells with rrSCF results in an almost pure outgrowth of mast cells.
Effect of chemical conjugation of recombinant single-chain urokinase- type plasminogen activator with monoclonal antiplatelet antibodies on platelet aggregation and on plasma clot lysis in vitro and in vivo
Authors: Dewerchin M , Lijnen HR , Stassen JM , De Cock F , Quertermous T , Ginsberg MH , Plow EF , Collen D 
Published: October 2019

Abstract
The murine monoclonal antiplatelet antibodies MA-TSPI-1 (directed against human thrombospondin) and MA-PMI-2, MA-PMI-1, and MA-LIBS-1 (directed against ligand-induced binding sites [LIBS] on human platelet glycoprotein IIb/IIIa) were conjugated with recombinant single-chain urokinase-type plasminogen activator (rscu-PA) using the cross-linking reagent N-succinimidyl 3-(2-pyridyldithio)propionate (SPDP). The conjugates (rscu-PA/MA-TSPI-1, rscu-PA/MA-PMI-2, rscu-PA/MA-PMI-1, and rscu-PA/MA-LIBS-1), purified by immunoadsorption and gel filtration, were obtained with recoveries of 34% to 45%, with an average stoichiometry of 1.6 to 1.8 IgG molecules per rscu-PA molecule, and with unaltered specific activities and affinities. Preincubation of human platelet-rich plasma with rscu-PA/MA-PMI-2, rscu-PA/MA-PMI-1, or unconjugated rscu-PA resulted in partial inhibition of ADP-induced aggregation; 25% inhibition was obtained with 63 micrograms/mL rscu-PA and with 6 micrograms u-PA/mL rscu-PA/MA-PMI-2 or 1.2 micrograms u- PA/mL rscu-PA/MA-PMI-1. In an in vitro system composed of a 125I-fibrin- labeled platelet-rich human plasma clot immersed in normal human plasma, the conjugates had threefold to greater than 15-fold less fibrinolytic potency than unconjugated rscu-PA. The thrombolytic potency of rscu-PA/MA-PMI-1 and rscu-PA/MA-LIBS-1 was compared with that of rscu-PA and that of a control conjugate rscu-PA/MA-1C8 in a pulmonary embolism model in the hamster, using clots prepared from platelet-poor or platelet-rich human plasma. Lysis was measured 30 minutes after the end of a 60-minute intravenous infusion of the thrombolytic agents. rscu-PA, rscu-PA/MA-PMI-1, rscu-PA/MA-LIBS-1, as well as rscu-PA/MA-1C8 had comparable thrombolytic potencies (percent lysis per dose administered) towards platelet-poor human plasma clots. In contrast, the thrombolytic potency of rscu-PA/MA-PMI-1 and of rscu- PA/MA-LIBS-1 towards platelet-rich clots was 2.3- to 3-fold higher than that of rscu-PA (P less than .005) and fivefold to sevenfold higher than that of the control conjugate (P less than .01).
Investigation of the mechanisms of monoclonal antibody-induced platelet activation
Authors: Horsewood P , Hayward CP , Warkentin TE , Kelton JG 
Published: October 2019

Abstract
Antiplatelet antibodies can activate platelets causing platelet aggregation and the release reaction. However, the pathway of activation by these antibodies is unknown and several potential mechanisms are possible. In this report, we describe studies investigating potential pathways of platelet activation by IgG antibodies. We tested 16 different IgG monoclonal antibodies (MoAbs) against a variety of platelet surface components and found that six antibodies were capable of causing platelet aggregation and release. These included MoAbs against glycoprotein (GP) IIb/IIIa, CD9, GPIV, and two other not well-characterized platelet components. There was no relationship between the number of platelet binding sites and the ability of an MoAb to activate the platelets. By adding intact and F(ab')2 preparations of the MoAb to control or Fc receptor-blocked platelets, we found that in all instances the MoAbs initiated platelet activation via interacting with the platelet Fc receptors. Clustering of the platelet protein components using a secondary antibody did not cause activation. Studies into the pathway of Fc-dependent activation demonstrated that the MoAbs were capable of activating platelets by occupying Fc receptors on adjacent platelets (interplatelet activation), as well as on the same platelet (intraplatelet activation).
Neutrophils express the high affinity receptor for IgG (Fc gamma RI, CD64) after in vivo application of recombinant human granulocyte colony- stimulating factor
Authors: Repp R , Valerius T , Sendler A , Gramatzki M , Iro H , Kalden JR , Platzer E 
Published: October 2019

Abstract
Fc receptors are important effector molecules of neutrophilic granulocytes (polymorphonuclear neutrophils [PMN]), connecting phagocytic cells and the specific immune response. Neutrophils from healthy donors express the low-affinity receptors for IgG Fc gamma RII (CD32) and Fc gamma RIII (CD16), but not the high-affinity receptor Fc gamma RI (CD64). The latter has been found on neutrophils from patients with certain bacterial infections and can be induced in vitro after incubation with interferon-gamma. We show here that neutrophils strongly express Fc gamma RI after in vivo application of recombinant human granulocyte colony-stimulating factor (rhG-CSF). PMN from patients receiving rhG-CSF displayed higher cytotoxicity against Daudi lymphoma cells in vitro compared with control patients and with healthy donors. Fab fragments against Fc gamma RII (monoclonal antibody [MoAb] IV.3) inhibited neutrophil-mediated cytotoxicity of healthy donors but not of patients during rhG-CSF therapy. Therefore, expression of Fc receptors by PMN was investigated by flow cytometry and the mean fluorescence intensity (MFI) was compared. After staining with MoAb 32.2 against Fc gamma RL, the median MFI of neutrophils from G-CSF patients (median, 4.78; range, 2.40 to 8.50; n = 5) was significantly higher (P = .002 and P = .001, respectively) than the median MFI of patients not receiving G-CSF (median, 1.23; range, 1.01 to 1.58; n = 6) and the median MFI of healthy donors (median, 1.04; range, 0.67 to 1.12; n = 6). Fc gamma RI disappeared after the discontinuing of the G- CSF injections, but was reinduced during the next treatment cycle with rhG-CSF. The high expression of Fc gamma RI during rhG-CSF therapy correlated with enhanced cytotoxicity. In vitro incubation with rhG-CSF also enhances cytotoxicity, but only minor increments in Fc gamma RI expression were observed. Thus, during in vivo application of rhG-CSF neutrophils acquire an additional potent receptor for mediating tumor cell killing in vitro by induction of the high-affinity receptor for IgG (Fc gamma RI, CD64).
Progression and survival studies in early chronic lymphocytic leukemia
Authors: Molica S 
Published: October 2019

Abstract
To investigate the natural history of stage A chronic lymphocytic leukemia (CLL) we reviewed 84 such patients. Among 74 cases evaluable for disease progression, 22 (29.6%) progressed to more advanced clinical stages (9 to stage B, 13 to stage C); the actuarial estimation of such an event at 4 years was 30% (95% CI: 26.3% to 33.6%). Despite a linear trend toward an increasing risk (r = .92), the hazard function analysis showed a constant pattern of progression, suggesting a lack of correlation of such an event with time (r = .04). Furthermore, disease progression when analyzed as a time-dependent variable had a clear-cut impact on survival (P less than .001). With the aim of identifying a subgroup of patients with low probability of disease progression and death, we applied to our set of patients four different proposals for subclassifying stage A. All methods were similar in terms of sample size, 5-year survival rate, and disease progression risk, suggesting that the choice between different proposals is somewhat arbitrary. Whatever the criteria are for defining “smoldering” CLL, such patients (accounting in the present study for 20.5% of overall series and 46.7% of stage A patients) should not be treated until progression occurs.
Functional characterization of an abnormal factor XII molecule (F XII Bern)
Authors: Wuillemin WA , Huber I , Furlan M , Lammle B 
Published: October 2019

Abstract
An 18-year-old healthy woman was found to have cross-reacting material (CRM)-positive factor XII (F XII) deficiency, F XII clotting activity was less than 0.01 U/mL, whereas F XII antigen was 0.11 U/mL. An F XII inhibitor was excluded. To partially characterize the molecular defect of the abnormal F XII, immunologic and functional studies were performed on the proposita's plasma. The abnormal F XII was a single chain molecule with the same molecular weight (80 Kd) and the same isoelectric points (pl, 5.9 to 6.8) as normal F XII. Dextran sulfate activation of the proposita's plasma showed no proteolytic cleavage of F XII even after 120 minutes, whereas F XII in pooled normal plasma, diluted 1:10 with CRM-negative F XII-deficient plasma, was completely cleaved after 40 minutes. Adsorption to kaolin was identical for both abnormal and normal F XII. In the presence of dextran sulfate and exogenous plasma kallikrein, the abnormal F XII was cleaved with the same rate as normal F XII. However, kallikrein-cleaved abnormal F XII was not able to cleave factor XI and plasma prekallikrein, in contrast to activated normal F XII. Thus, these studies show that the functional defect of this abnormal F XII, denoted as F XII Bern, is due to the lack of protease activity of the kallikrein-cleaved molecule. Therefore, the structural defect is likely to be located in the light chain region of F XII, containing the enzymatic active site.
Platelet activation by a synthetic hydrophobic polymer, polymethylmethacrylate
Authors: Ware JA , Kang J , DeCenzo MT , Smith M , Watkins SC , Slayter HS , Saitoh M 
Published: October 2019

Abstract
Platelets adhere to artificial surfaces in the initial stage of thrombus formation, but the subsequent steps in signal transduction that lead to platelet activation by artificial surfaces are not understood. When 0.325-micron diameter beads composed of a hydrophobic polymer, polymethylmethacrylate (PMMA), were added to gel-filtered aequorin-loaded platelets suspended in media containing Ca2+, the platelets aggregated; addition of fibrinogen was not required. Platelet aggregation was preceded by an increase in cytoplasmic Ca2+ and was accompanied by phosphorylation of the 47-Kd substrate of protein kinase C (PKC), 5-hydroxytryptamine (5-HT) release, and accumulation of phosphatidic acid. All these effects were partially inhibited by apyrase and aspirin. Monoclonal antibodies (MoAbs) 7E3 and M148 and the synthetic peptides RGDS and fibrinogen gamma chain fragment 400–411, all of which bind to the platelet fibrinogen receptor glycoprotein IIb- IIIa (GPIIb-IIIa) and inhibit fibrinogen binding, prevented PMMA- induced aggregation but did not inhibit the Ca2+ increase. Chymotrypsin- treated platelets aggregated after addition of fibrinogen, but not PMMA. We conclude that platelets interact initially with PMMA at membrane sites other than those required for fibrinogen binding, leading to activation of membrane phospholipases and PKC, an increase in cytoplasmic Ca2+, release of 5-HT, ADP, and fibrinogen from storage granules, and to platelet aggregation.
Role of AUUU sequences in stabilization of granulocyte-macrophage colony-stimulating factor RNA in stimulated cells
Authors: Akashi M , Shaw G , Gross M , Saito M , Koeffler HP 
Published: October 2019

Abstract
RNAs for transiently expressed genes such as oncogenes and cytokines, including granulocyte-monocyte colony-stimulating factor (GM-CSF), have a short half-life (T1/2). A cluster of AUUU sequences identified in the 3′ untranslated (UT) region of these RNAs has been implicated in controlling stability of these transcripts. We examined the role of AUUU sequences in mRNA stability of GM-CSF after stimulation of cells. Human fibroblasts (W138) were stably transfected with chimeric constructs containing the beta-globin gene linked to a 52-bp tail of GM- CSF containing either eight ATTTT (pNEOR beta G-AT) or eight repeats in which the AT sequences have been changed to GC sequences (pNEOR beta G- GC). Data confirmed that AUUU sequences in 3′UT region of GM-CSF play a major role in GM-CSF RNA instability. Stimulators of protein kinase C (PKC), cycloheximide (CHX), sodium fluoride (NaF), and, to a more limited extent, interleukin-1 beta (IL-1 beta), appear to stabilize GM- CSF RNA through these AUUU sequences, but tumor necrosis factor-alpha (TNF-alpha) induces stabilization of GM-CSF RNA through a mechanism independent of their AUUU sequences.
Role of glycoprotein IIa (beta 1 subunit of very late activation antigens) in platelet functions
Authors: Parmentier S , Catimel B , McGregor L , Leung LL , McGregor JL 
Published: October 2019

Abstract
Very late activation antigens (VLAs) are glycoproteins (GPs) that play a major role in platelet adhesion to extracellular matrix. These GPs, members of the integrin family, are heterodimer complexes with different alpha subunits noncovalently associated with a common beta 1 subunit known as GPIIa. GPIa-IIa (also known as VLA2), GPIc-IIa (VLA5), and GPIc*-IIa (VLA6) are involved, respectively, in platelet adhesion to collagen, fibronectin, and laminin. At this stage, very little is known about the role of GPIIa in platelet adhesive functions. In this study, we have generated a monoclonal antibody (MoAb) (LYP22) directed against GPIIa. Immunoaffinity chromatography using LYP22 combined with two-dimensional nonreduced-reduced sodium dodecyl sulfate- polyacrylamide gel electrophoresis shows that the antibody brings down all VLA subunits. Western blots indicate that the binding site of LYP22 on GPIIa is disulfide bridge-dependent. The number of LYP22 binding sites is not increased on stimulation with thrombin and is in the range of what is observed with another anti-GPIIa MoAb (A-1A5). LYP22 is the first anti-GPIIa MoAb to inhibit aggregation and secretion of washed platelets stimulated with collagen, thrombin, or arachidonic acid. Moreover, the lag-phase usually observed on collagen stimulation is significantly prolonged (by 60 seconds) in the presence of LYP22. This lag-phase, mediated by LYP22, is also observed in the presence of plasma proteins and is coupled with a reduced effect on collagen- induced platelet aggregation. In addition, LYP22 affects the adhesion of resting platelets to type III collagen, but not to fibronectin, laminin, or type I collagen. These results strongly indicate that the site on GPIIa, bearing the LYP22 epitope, is an active participant in signal transduction controlling platelet functions.
High-dose recombinant interleukin-2 and acute myeloid leukemias in relapse
Authors: Maraninchi D , Blaise D , Viens P , Brandely M , Olive D , Lopez M , Sainty D , Marit G , Stoppa AM , Reiffers J 
Published: October 2019

Abstract
Interleukin-2 (IL-2) is able to induce the regression of metastatic cancers when administered in vivo. IL-2-activated natural killer cells and lymphocytes show, in vitro, activities against leukemic cells. To assess if in vitro observations could have significant clinical relevance, we evaluated the in vivo activity of high-dose recombinant IL-2 (6 to 8 x 10(6) IU/m2/8H intravenous bolus for 5 days) in 10 patients with acute myeloid leukemias (AML) in relapse after chemotherapy (n = 7) or autologous bone marrow transplantation (n = 3). Two patients achieved a complete remission and one had a minimal improvement in his marrow blast cells. Response was observed after one cycle of IL-2 in the two patients achieving a complete remission. These two patients relapsed at 3 and 4 months. These results showing clinical activity of high-dose recombinant IL-2 in AML invite further evaluation of this new form of immunotherapy in other clinical situations, like an adjuvant setting for selected groups of high-risk patients.
Binding of tissue plasminogen activator to human monocytes and monocytoid cells
Authors: Felez J , Chanquia CJ , Levin EG , Miles LA , Plow EF 
Published: October 2019

Abstract
Monocytes and monocytoid cell lines previously have been shown to express receptors for plasminogen and urokinase (u-PA). In the present study, the monocytoid cell lines, U937 and THP-1, are shown to bind tissue plasminogen activator (t-PA) in a specific, saturable, and reversible manner. These cells bound t-PA with low affinity (kd = 0.67 to 0.97 mumol/L) and high capacity (0.71 to 3.3 x 10(6) receptors/cell). Human peripheral blood monocytes bound t-PA with a kd (0.9 mumol/L) similar to that of the monocytoid cells but with a lower capacity (0.17 x 10(6) sites/cell). These binding parameters also were similar to the low-affinity interaction of t-PA with endothelial cells as measured with the cells in suspension (kd = 0.73 mumol/L and 1.1 x 10(6) sites/cell). Lysine analogues and active or diisopropylfluorophosphate-inactivated u-PA inhibited t-PA binding to monocytes, monocytoid cells, and endothelial cells with similar IC50 (concentration producing 50% inhibition) values, suggesting that the same recognition specificity mediates t-PA binding to all of these cell types. The existence of a high-affinity binding site for t-PA on monocytoid cells was also explored in detail. Unlike endothelial cells where plasminogen activator inhibitor-1 has been implicated in mediating a high-affinity interaction of t-PA with the cells, no evidence for a role of this inhibitor in ligand binding to the monocytoid cells was found. Furthermore, using both high and low 125I-t- PA concentrations, competition analyses with lysine analogues or u-PA, or treatment of the cells with carboxypeptidase B, failed to indicate the presence of distinguishable classes of t-PA binding sites. In sum, low-affinity receptors for t-PA are expressed at high density on monocytes and monocytoid cells, identifying a new element in the fibrinolytic arsenal of these cells.
BCR-ABL rearrangements in children with Philadelphia chromosome- positive chronic myelogenous leukemia
Authors: Aurer I , Butturini A , Gale RP 
Published: October 2019

Abstract
Leukemia cells from adults with Philadelphia (Ph1)-chromosome positive chronic myelogenous leukemia (CML) have a characteristic molecular rearrangement between the BCR and ABL genes whereby major breakpoint cluster region (Mbcr) exons 2 or 3 are joined to ABL exon II. Ph1- chromosome positive CML is uncommon in children and it is unknown whether these children have similar rearrangements. We studied 17 children with Ph1-chromosome positive CML. Five were studied for Mbcr rearrangement using Southern blotting, nine for the presence of chimeric BCR-ABL mRNA using reverse transcription and polymerase chain reaction, and three for both. All eight children studied by Southern blotting had BCR rearrangement. Of 12 children in whom BCR-ABL mRNA was studied, 10 had Mbcr exon 2 joined to ABL exon II, one had Mbcr exon 3 joined to ABL II, and one had both Mbcr-ABL junctions. These data indicate a similarity to adult CML. However, mRNA processing in children may preferentially splice Mbcr exon 2 to ABL exon II. No child had BCR exon 1 joined to ABL exon II, the rearrangement typical of childhood Ph1-chromosome positive acute lymphoblastic leukemia.