bluuebunny/crossref_metadata_2025_split huggingface dataset:
Human erythropoietin-specific sites of monoclonal antibody-mediated neutralization
Authors: Fibi MR , Aslan M , Hintz-Obertreis P , Pauly JU , Gerken M , Luben G , Lauffer L , Siebold B , Stuber W , Nau G 
Published: October 2019

Abstract
Recombinant human erythropoietin (rhuEpo)-specific mouse monoclonal antibodies (MoAbs) have been produced and characterized. All antibodies were specifically reactive with rhuEpo in enzyme-linked immunosorbent assay (ELISA). Epitope exclusion studies showed three distinct epitope regions, A, B, and C, recognized by neutralizing MoAbs. An additional epitope region D was recognized by non-neutralizing MoAbs. Antibodies defining an epitope region competed with each other for binding sites, but did not compete with antibodies defining a different epitope region. Group B antibodies were able to compete for the receptor binding site on rhuEpo with a soluble human Epo-receptor-lg fusion protein. No single peptide sequences were found to specifically interact either with group B MoAbs or with the rhuEpo-receptor. Therefore, it is suggested that epitope region B and the receptor binding site share binding determinants that are primarily composed of conformational epitopes. Because group A and group C antibodies did not compete with the receptor for binding to the receptor binding site of the rhuEpo molecule, it is suggested that neutralization via epitope regions A and C is mediated through binding inhibition caused by conformational changes, transmuting the binding site(s) for the receptor. Conversely, binding to the receptor seems to induce conformational changes in the hormone molecule, eliminating epitopes for group A and C antibodies.
Biologically active thrombomodulin is synthesized by adherent synovial fluid cells and is elevated in synovial fluid of patients with rheumatoid arthritis
Authors: Conway EM , Nowakowski B 
Published: October 2019

Abstract
Thrombomodulin (TM) is a transmembrane glycoprotein that interacts with thrombin, thereby serving as a cofactor in the activation of protein C, a major physiologically relevant natural anticoagulant. Although initially described as a vascular endothelial cell receptor, TM has also been reported to be synthesized by several cells, including megakaryocytes, platelets, monocytes, neutrophils (PMN), mesothelial cells, and synovial lining cells. A prominent feature of rheumatoid arthritis (RA) is infiltration of PMN into the joint space. To determine whether TM might play a role in the inflammatory process, we examined synovial fluid for the presence of TM in 10 patients with RA and five patients with osteoarthritis (OA). We determined that the mean synovial fluid and plasma TM levels in the OA group were 23.5 ng/mL and 24.2 ng/mL, respectively, whereas those with RA had a significantly elevated mean synovial fluid TM level of 136.2 ng/mL as compared with the plasma TM concentration of 43.9 ng/mL (P < .05). Synovial fluid TM levels did not correlate with PMN counts (r = .261). Purified TM from synovial fluid was identical in molecular weight to plasma-derived TM and was biologically functional with respect to protein C cofactor activity. Using direct immunofluorescence, we determined that adherent cultured synovial fluid cells that are not monocytoid in origin express surface and cytoplasmic TM, thereby providing an alternative source of the protein. Biologic activity of the cell-surface TM was confirmed by acceleration of thrombin-dependent protein C activation. Northern analysis of RNA extracted from the cultured cells indicated that TM messenger RNA was present, suggesting local synthesis. Our results indicate that in RA-associated synovial effusions, biologically active TM is increased, the source of which may be from plasma, PMN, and/or synovial lining cells. TM may play a regulatory role either in fibrin deposition in the inflamed joint and/or in the progression of the inflammatory process.
Immunoglobulins from normal sera bind platelet vinculin and talin and their proteolytic fragments
Authors: Reid DM , Jones CE , Luo CY , Shulman NR 
Published: October 2019

Abstract
Our previous finding that normal serum immunoglobulins bind to internal platelet proteins on Western blots led us to further identify these proteins and determine the possible significance of autoantibodies against them. A 95-Kd protein reactive with immunoglobulins in most normal sera and easily confused with gpIIIa was shown to be a fragment of vinculin generated by calpain proteolysis. Identity was established by peptide sequencing of the protein purified from platelets stored without specific protease inhibitors. Normal immunoglobulins bound intact vinculin (117 Kd) and metavinculin (152 Kd), and their 105-, 95- , and 80- to 85-Kd proteolytic fragments. IgG in 89%, and IgA and IgM in 100% of normal sera reacted in titers of 10 to 1,000 with purified vinculin. In addition, IgG in 79%, and IgA and IgM in 93% of normal sera reacted in titers of 10 to 5,000 with talin (235 Kd), another cytoskeletal protein, and its 200-Kd proteolytic fragment. IgGs in sera from animals of several different phylogenetic classes also reacted with human vinculin and talin on Western blots. Frequency of occurrence, titers, and classes of antivinculin and antitalin autoantibodies in patients with thrombocytopenia did not differ discernibly from those of normal individuals. These antibodies had no effect on platelet aggregation or clot retraction, and no apparent pathogenic significance, but their widespread presence and the variability in extent of proteolysis of platelet preparations used for Western blots can complicate interpretation of patterns obtained with sera from patients with presumed immune-mediated thrombocytopenias.
9-cis-retinoic acid: effects on normal and leukemic hematopoiesis in vitro
Authors: Sakashita A , Kizaki M , Pakkala S , Schiller G , Tsuruoka N , Tomosaki R , Cameron JF , Dawson MI , Koeffler HP 
Published: October 2019

Abstract
Retinoic acid exhibits effects on the proliferation and differentiation of many hematopoietic cells. Cellular responsiveness to retinoic acid (RA) is conferred through two distinct classes of nuclear receptors, the RA receptors (RARs) and the retinoid X receptors (RXRs). The RARs bind to both 9-cis- and all-trans-RAs, but 9-cis-RA alone directly binds and activates RXR. This suggested that 9-cis-RA could have expanded hematopoietic activities as compared with all-trans-RA. We compared the abilities of 9-cis- and all-trans-RAs to induce differentiation and inhibit proliferation of three acute myelogenous leukemia (AML) cell lines and fresh leukemic cells from 28 patients and found that: (1) 9-cis-RA in general was more potent than all-trans-RA in suppressing the clonal growth of two AML cell lines and 17 AML samples from patients, including four from individuals with acute promyelocytic leukemia (APL). Eleven leukemic samples, including three from patients with chronic myelogenous or chronic myelomonocytic leukemia, were relatively refractory to both retinoids. (2) The range of activities of both retinoids was similar except that the clonal growth of samples from three AML patients were inhibited by 9-cis-RA, but not by all-trans-RA. (3) Both retinoids inhibited the clonal proliferation of leukemia cells without necessarily inducing their differentiation; in fact, the only fresh AML cells that were able to undergo differentiation were from patients with APL and one individual with M2 AML. (4) Both retinoids enhanced myeloid and erythroid clonal growth from normal individuals, and 9-cis-RA showed slightly more stimulation of the myeloid clonal growth than did the all-trans-RA. Our study suggests that 9-cis-RA is worthy of further study for the treatment of selected individuals with AML.
Prolonged survival of B-lineage acute lymphoblastic leukemia cells is accompanied by overexpression of bcl-2 protein
Authors: Campana D , Coustan-Smith E , Manabe A , Buschle M , Raimondi SC , Behm FG , Ashmun R , Arico M , Biondi A , Pui CH 
Published: October 2019

Abstract
Overexpression of bcl-2 delays the onset of apoptosis in lymphohematopoietic cells. We measured levels of bcl-2 protein in normal and leukemic human B-cell progenitors with a specific monoclonal antibody and flow cytometry. Normal immature B cells had low levels of bcl-2 protein; the intensity of fluorescence, expressed as molecules of soluble fluorochrome per cell, within CD10+ cells was 3,460 +/- 1,050 (mean +/- SD; 5 samples). In 16 cases of B-lineage acute lymphoblastic leukemia (ALL), cells had levels of bcl-2 that were strikingly higher than those of their normal counterparts (33,560 +/- 14,570; P < .001 by t-test analysis). We next investigated whether the intensity of bcl-2 expression correlated with the resistance of immature B cells to in vitro culture. In 12 cases of B-lineage ALL, the cells recovered after 7 days of culture on allogeneic bone marrow stromal layers were 69% to 178% (median, 95.5%) of those originally seeded. Prolonged survival of leukemic cells in vitro was observed even in the absence of stromal layers in 6 of these 12 cases; the intensity of bcl-2 protein expression in these cases was 45,000 +/- 13,270, compared with 21,500 +/- 7,260 in the 6 cases in which greater than 99.5% of cells rapidly died by apoptosis under the same culture conditions (P = .003). Five immature B-cell lines, continuously growing in the absence of stroma, had the highest bcl-2 expression (79,400 +/- 20,330). By contrast, most normal CD19+, sIg-immature B cells died despite the presence of bone marrow stromal layers; 9.7% to 28.2% were recovered after 7 days of culture in three experiments. We conclude that abnormal bcl-2 gene expression influences the survival ability of B-cell progenitors. This may contribute to leukemogenesis and explain the aptitude of leukemic lymphoblasts to expand outside the bone marrow microenvironment.
The 5q- syndrome: a single-institution study of 43 consecutive patients
Authors: Mathew P , Tefferi A , Dewald GW , Goldberg SL , Su J , Hoagland HC , Noel P 
Published: October 2019

Abstract
A favorable prognosis and a low rate of leukemic transformation has been attributed to the 5q- syndrome, a myelodysplastic syndrome (MDS) characterized by macrocytic anemia, hypolobulated micromegakaryocytic hyperplasia, and an interstitial deletion of chromosome 5. We examined the characteristics and outcome of 43 consecutive patients in our institution strictly defined by morphologic criteria and a solitary 5q- cytogenetic defect. The median age at diagnosis was 68 years, with a clear female predominance (7:3). Eighty percent of the patients were red blood cell transfusion-dependent at diagnosis and all untransfused patients had macrocytic indexes. In contrast, significant neutropenia or thrombocytopenia was rare. The French-American-British (FAB) class distributions were RA (72%), RARS (7%), RAEB (16%), and RAEB-IT (5%). At a median follow-up of 31 months, 56% of the patients survive, with a projected median survival of 63 months. The incidence of acute leukemia was 16% and was uniformly fatal. Clinical hemosiderosis occurred in 28% of the patients, resulting in two deaths. Neither survival nor the risk of leukemic transformation was predictable from initial clinical parameters, including FAB classification, Bournemouth score, and degree of aneuploidy. The lack of significant neutropenia and thrombocytopenia seemed to account for a very low incidence of infection and bleeding resulting in a prognosis equal or superior to historical patients with MDS. Therapeutic endeavors, including the use of corticosteroids, androgens, cis-retinoic acid, pyridoxine, and danazol, were largely unsuccessful.
Transferrin synthesis by mouse lymph node and peritoneal macrophages: iron content and effect on lymphocyte proliferation
Authors: Djeha A , Perez-Arellano JL , Brock JH 
Published: October 2019

Abstract
Transferrin is an essential requirement for lymphocyte proliferation, because it supplies activated lymphocytes with iron needed for cell proliferation. However, during inflammation or an immune response, the iron content of circulating transferrin, which is of hepatic origin, decreases. It is hypothesized that activated lymphocytes may therefore obtain transferrin-iron from an alternative source, and we have investigated the possibility that transferrin is synthesized locally in lymphoid tissues. It was found that lymph node cells from mice stimulated in vivo with Freund's complete adjuvant were able to synthesize transferrin, and this was because of the macrophage rather than the lymphocyte population. Transferrin synthesized by mouse lymph node or peritoneal macrophages contained iron and was able to promote mouse lymphocyte proliferation. Peritoneal macrophages activated in vivo synthesized more transferrin, released more transferrin-bound iron, and were more effective than resident macrophages at enhancing lymphocyte proliferation. These results suggest that transferrin synthesized by macrophages acts in a paracrine manner to support lymphocyte proliferation, thus eliminating possible detrimental effect of hypoferremia on the immune system.
Quantitative assessment of erythropoiesis and functional classification of anemia based on measurements of serum transferrin receptor and erythropoietin
Authors: Beguin Y , Clemons GK , Pootrakul P , Fillet G 
Published: October 2019

Abstract
We evaluated the quantitative value of a simple model of erythropoiesis, based on the basic assumptions that the red blood cell (RBC) mass determines erythropoietin (Epo) production, which in turn stimulates erythropoietic activity. The RBC mass was quantitated by direct isotopic measurement (RCM), Epo production by serum Epo levels, and erythropoiesis by the ferrokinetic measurement of the erythron transferrin uptake (ETU), the serum transferrin receptor (TfR) level, and the reticulocyte (retic) index, and was completed by an evaluation of overall marrow erythron cellularity. We studied a total of 195 subjects, including 31 normal individuals, 38 patients with polycythemia, and 126 patients with various forms of anemia. Instead of only quantitating Epo and erythropoiesis in absolute terms, we also evaluated them in relation to the degree of anemia or polycythemia, and expressed the results as a ratio of observed values to values predicted from the regression equations between hematocrit (Hct) on the one hand, and Epo, TfR, and ETU on the other, obtained in a carefully selected subpopulation. The slope of the regression of TfR (as well as ETU) versus Hct was very similar to the slope of the regression of Epo versus Hct. Average EPO and TfR (as well as ETU) values predicted from the regression equations were quite comparable to observed values in most groups of subjects, with exceptions predictable from knowledge of the pathophysiology of these hematologic disorders. We identified four major patterns of erythropoiesis, ie, normal, hyperdestruction (with variants of hemolysis or ineffective erythropoiesis), intrinsic marrow hypoproliferation, and defective Epo production. Dissecting out groups of patients showed much greater heterogeneity than when patients were analyzed by group. This was particularly true in the case of a hypoproliferative component being combined with hyperdestruction, giving what we called a “mixed disorder of erythropoiesis.” We conclude that the pathophysiology of anemia can be assessed by a simple measurement of Hct, retic index, Epo, and TfR levels, with Epo and TfR being more informative when expressed in relation to the degree of anemia. The model is particularly useful for detecting the presence of multiple mechanisms of anemia in the same patient. However, it has limitations inherent to the relative invalidity of TfR in iron deficiency, the imprecision of a retic count, and the difficulty in distinguishing hemolysis from ineffective erythropoiesis in some patients and in recognizing a component of hyperdestruction in hypoproliferative anemia.
Methotrexate, cyclosporine, or both to prevent graft-versus-host disease after HLA-identical sibling bone marrow transplants for early leukemia?
Authors: Ringden O , Horowitz MM , Sondel P , Gale RP , Biggs JC , Champlin RE , Deeg HJ , Dicke K , Masaoka T , Powles RL 
Published: October 2019

Abstract
Optimal prophylaxis of graft-versus-host disease (GVHD) is controversial. We compared efficacy of three posttransplant immune suppressive regimens in 2,286 recipients of HLA-identical sibling bone marrow transplants for acute lymphoblastic leukemia (ALL) in first remission, acute myelogenous leukemia (AML) in first remission, or chronic myelogenous leukemia (CML) in first chronic phase. Six hundred forty received methotrexate, 977 received cyclosporine, and 669 received combined cyclosporine and methotrexate. In children, the three regimens resulted in similar outcomes. In adults, cyclosporine and methotrexate had comparable risks of acute and chronic GVHD. Compared with methotrexate, cyclosporine was associated with less interstitial pneumonia (relative risk [RR] = 0.6; P < .001), less treatment-related mortality (RR = 0.6; P < .001), more relapses (RR = 1.6; P < .05), and less treatment failure (relapse or death from any cause; RR = 0.7; P < .001). Different effects were observed in different leukemias. In ALL, the rate of leukemia relapse was increased with cyclosporine versus methotrexate, with no effect on other outcomes. In AML and CML, interstitial pneumonia, treatment-related mortality, and treatment failures were decreased with cyclosporine, with no increase in relapse. Similar analyses comparing cyclosporine plus methotrexate with cyclosporine alone showed that adults receiving the combination had less acute GVHD (RR = 0.5; P < .001), less chronic GVHD (RR = 0.7; P < .01), and less interstitial pneumonia (RR = 0.7; P < .001). Treatment failure (RR = 0.8; P < .05) was marginally reduced. Separate analyses in ALL and AML showed less acute GVHD with combined therapy, but no significant effect on other outcomes. In CML, acute GVHD, interstitial pneumonia, treatment-related mortality, and treatment failure were decreased with combined therapy.
Detection of DNA rearrangements in the AML1 and ETO loci and of an AML1/ETO fusion mRNA in patients with t(8;21) acute myeloid leukemia
Authors: Nucifora G , Birn DJ , Erickson P , Gao J , LeBeau MM , Drabkin HA , Rowley JD 
Published: October 2019

Abstract
The (8;21)(q22;q22) translocation is a frequent karyotypic abnormality seen in approximately 40% of patients with acute myeloid leukemia subtype M2 (AML-M2) and an abnormal karyotype. The translocation interrupts two genes, AML1 on chromosome 21 and ETO on chromosome 8, that are consequently fused in the der(8) chromosome to produce a novel chimeric gene and message. Selected genomic DNA probes from chromosome 21 and from chromosome 8 near the breakpoint junction detect rearrangements in the DNA of about 80% of the patients with the rearrangement at diagnosis and in relapse. We analyzed the DNA of 20 patients with t(8;21) AML by standard Southern blot with probes originating from chromosomes 21 and 8 near the breakpoint junction, and we identified rearranged bands in 17 of the 20 patients at diagnosis and in relapse. We also used the polymerase chain reaction (PCR) with appropriate primers from the AML1 and ETO genes to amplify the cDNAs from a cell line with the t(8;21) and from seven AML patients with the t(8;21). We detected a fused transcript in the cell line and in all of the patients analyzed, including three patients who did not show any rearrangement by Southern blot analysis and one patient in hematologic remission, who later relapsed. Combining the results from Southern blot and PCR analysis, we could detect the t(8;21) in all of the patients tested. These results indicate that, whereas several DNA probes used as genetic markers do detect the t(8;21) in most, but not all Southern blots of patients with AML, PCR amplification with primers from AML1 and ETO can be used as a more sensitive and accurate means for detecting this chromosomal abnormality, and for observing the patients' response to therapy.
Recombinant human interleukin-11 stimulates megakaryocytopoiesis and increases peripheral platelets in normal and splenectomized mice
Authors: Neben TY , Loebelenz J , Hayes L , McCarthy K , Stoudemire J , Schaub R , Goldman SJ 
Published: October 2019

Abstract
The effects of recombinant human interleukin-11 (rhIL-11) on in vivo mouse megakaryocytopoeisis were examined. Normal C57Bl/6 mice and splenectomized C57Bl/6 mice were treated for 7 days with 150 micrograms/kg rhIL-11 administered subcutaneously. In normal mice, peripheral platelet counts were elevated compared with vehicle-treated controls after 3 days of rhIL-11 treatment and remained elevated until day 10. Splenectomized mice treated with rhIL-11 showed elevated peripheral platelet counts that were similar in magnitude to normal rhIL-11-treated mice. However, on day 10 the platelet counts in rhIL-11- treated, splenectomized mice were no longer elevated. Analysis of bone marrow megakaryocyte ploidy by two-color flow cytometry showed an increase, relative to controls, in the percentage of 32N megakaryocytes in both normal and splenectomized animals treated with rhIL-11. In normal mice, the number of spleen megakaryocyte colony-forming cells (MEG-CFC) were increased twofold to threefold relative to controls after 3 and 7 days of rhIL-11 treatment, whereas the number of bone marrow MEG-CFC were increased only on day 7. The number of MEG-CFC in the bone marrow of rhIL-11-treated, splenectomized mice was increased twofold compared with controls on both days 3 and 7 of the study. These data show that in vivo treatment of normal or splenectomized mice with rhIL-11 increased megakaryocyte progenitors, stimulated endoreplication of bone marrow megakaryocytes, and increased peripheral platelet counts. In addition, results in splenectomized mice showed that splenic hematopoiesis was not essential for the observed increases in peripheral platelets in response to rhIL-11 administration.
Basic fibroblast growth factor counteracts the suppressive effect of transforming growth factor-beta 1 on human myeloid progenitor cells
Authors: Gabrilove JL , Wong G , Bollenbacher E , White K , Kojima S , Wilson EL 
Published: October 2019

Abstract
We have previously shown that basic fibroblast growth factor (bFGF) is mitogenic for human bone marrow stromal cells and enhances myelopoiesis in human long-term bone marrow culture. In the present study, we examined the mechanism by which bFGF enhances granulopoiesis. We observed that bFGF significantly abrogated the inhibitory effect of transforming growth factor-beta 1 (TGF-beta 1) on granulocyte- macrophage colony-stimulating factor (GM-CSF)-supported progenitor cell growth (P = .009). The partial reversal of TGF-beta 1-mediated suppression was dependent on the dose of bFGF used. In addition, we noted that the inclusion of neutralizing antibody to TGF-beta 1 significantly augmented the clonogenic response to GM-CSF. We have also shown that 10 ng/mL or 100 ng/mL of bFGF resulted in a 30% to 100% increase in GM-CSF-mediated progenitor cell growth (P = .0001). These data suggest that bFGF may enhance myelopoiesis by modulating the inhibitory response to TGF-beta 1.