bluuebunny/crossref_metadata_2025_split huggingface dataset:
A ricin A chain-containing immunotoxin that kills human T lymphocytes in vitro
Authors: Martin PJ , Hansen JA , Vitetta ES 
Published: October 2019

Abstract
An immunotoxin specific for human T lymphocytes was prepared by coupling an IgG2a anti-CD3 murine monoclonal antibody (64.1) to purified ricin A chain (64.1-A). Treatment of blood mononuclear cells with this immunotoxin at a concentration of 1.7 X 10(-9) mol/L for two hours at 37 degrees C in the presence of 20 mmol/L NH4Cl decreased phytohemagglutinin-stimulated protein synthesis by 95%. In addition, a sensitive culture assay showed that fewer than 0.03% T cells remained after treatment of human bone marrow mononuclear cells with 64.1-A at a concentration of 1.7 X 10(-9) mol/L. The inhibition of protein synthesis could be prevented by preincubating cells with unconjugated 64.1 antibody but not by preincubating cells with a control IgG2a antibody that binds to a different T cell antigen (CD5). At concentrations up to 1 X 10(-8) mol/L, 64.1-A had little effect on blood mononuclear cells from baboons or human myeloid precursors (CFU- GM), which do not express the CD3 antigen recognized by 64.1. Taken together, these results indicate that the toxicity of 64.1-A was specific and that 64.1-A may be a useful reagent for depleting T cells from donor marrow as a means of preventing acute graft-v-host disease after allogeneic bone marrow transplantation.
Production of monoclonal antibodies to the high fibrin-affinity, tissue- type plasminogen activator of human plasma. Demonstration of its endothelial origin by immunolocalization
Authors: Angles-Cano E , Balaton A , Le Bonniec B , Genot E , Elion J , Sultan Y 
Published: October 2019

Abstract
Monoclonal antibodies (MAbs) to vascular plasminogen activator (vPA), the tissue-type plasminogen activator (tPA) in human plasma, were produced to be used as probes for immunochemical analysis. Human tissue sections and one of these MAbs were used to demonstrate the endothelial origin of plasma-tPA by immunohistochemistry. To produce MAbs, mice were immunized with semipurified vPA isolated from postocclusion human venous blood. Primed spleen cells were fused with the mouse myeloma cell line NS-1. Screening for MAb-producing hybridomas was performed with postocclusion euglobulins as a source of antigen by means of a solid-phase fibrin-vPA immunoassay. The selective and high-affinity binding of vPA for fibrin ensures the specificity and sensitivity of this test. Thus, eight hybridomas secreting MAbs to vPA were selected, cloned, and established as permanent hybridoma cell lines. Immunohistochemical analysis of cryostat sections of human tissues was performed with EA-delta 12D, a MAb having no inhibitory effect against vPA activity but binding to vPA with a high affinity. Thus, the only structures immunostained were endothelial cells of venules, capillaries, and arterioles. The EA-delta 12D monoclonal localization of plasma vPA in the endothelial lining of blood vessels provides evidence that tPA in plasma originates from the vascular wall and validates its designation as vascular plasminogen activator, ie, vPA. Also, our results are consistent with the fact that vPA in blood and tPA in tissues are immunologically identical and have a common endothelial origin.
Delay in platelet recovery after bone marrow transplantation: impact of cytomegalovirus infection
Authors: Verdonck LF , van Heugten H , de Gast GC 
Published: October 2019

Abstract
The effect of cytomegalovirus (CMV) infection on hematopoietic recovery after marrow-ablative chemoradiotherapy followed by autologous bone marrow transplantation (BMT) was studied in patients with non-Hodgkin's lymphoma of high-grade malignancy and in patients with acute leukemia. The recovery of platelets after autologous BMT occurred significantly quicker in CMV-negative patients than in CMV-positive patients (platelets greater than 50,000 per cubic millimeter after 21 1/2 v 40 days, respectively). No differences in the recovery of neutrophils were found between those with or without CMV infection. CMV-positive patients required significantly more transfusion support with thrombocyte concentrates than CMV-negative patients (three v six thrombocyte concentrates). In conclusion, CMV infections do not influence neutrophil recovery but do delay platelet recovery. As a consequence, patients with a CMV infection, whether primary, reactivated, or latent, require more thrombocyte concentrates, which increases the risk of transfusion-related infections.
Detection of two distinct malignant B cell clones in a single patient using anti-idiotype monoclonal antibodies and immunoglobulin gene rearrangement
Authors: Giardina SL , Schroff RW , Woodhouse CS , Golde DW , Oldham RK , Cleary ML , Sklar J , Pritikin N , Foon KA 
Published: October 2019

Abstract
Immunoglobulin gene rearrangement analysis and somatic cell hybridization techniques were used to examine the malignant cell population in an unusual patient with hairy cell leukemia and macroglobulinemia (N Engl J Med 296:92, 1977). Although previous investigations suggested that the IgM macroglobulin was secreted by the circulating leukemia cells, anti-idiotype monoclonal antibodies raised to the IgM macroglobulin failed to react with the malignant cells in the circulation and bone marrow. In contrast, approximately 50% of the mononuclear cells from an enlarged inguinal lymph node reacted strongly with the anti-idiotype antibodies. Subsequent reanalysis of all cell populations demonstrated that whereas the circulating and bone marrow cells were IgM kappa-bearing, the macroglobulin was IgM gamma-bearing and the lymph node cells were evenly divided among IgM kappa-bearing and IgM gamma-bearing. Immunofluorescence flow cytometry indicated that those lymph node cells that reacted strictly with the anti-idiotype antibody were IgM gamma-bearing, demonstrating that they were the source of macroglobulin. An analysis of immunoglobulin gene DNA confirmed the coexistence of two distinct malignant B cell populations in the lymph node and indicated that the IgM kappa-bearing lymph node cells were identical to the circulating and bone marrow leukemic cells.
Increased activity of a specific sialyltransferase in chronic myelogenous leukemia
Authors: Baker MA , Taub RN , Kanani A , Brockhausen I , Hindenburg A 
Published: October 2019

Abstract
Granulocytes from patients with chronic myelogenous leukemia (CML) are morphologically identical to their normal counterparts but show marked differences in circulation patterns and in some membrane properties. We have previously shown that there is abnormal lectin binding to CML granulocytes, and aberrant sialylation of membrane glycoproteins. To examine the changes in sialylation of CML granulocytes further, we have studied membrane preparations from CML and normal granulocytes for specific sialyltransferase activity. Because sialyltransferase enzymes are specific for the configuration of the acceptor group, enzyme activity was assayed by measuring transfer of sialic acid from CMP-14C- sialic acid to substrates of defined structure. As compared with those of normal counterparts, CML extracts catalyzed a 50% higher overall rate of sialylation of asialofetuin, a substrate possessing both N- and O-linked acceptors. Studies of enzyme specificity utilizing porcine and ovine submaxillary mucins, antifreeze glycoprotein and alpha-1 acid glycoprotein as acceptors showed that the increased sialylation by CML extracts was due primarily to substrates with the O-linked Gal beta 1--- -3GaINAc acceptor group. These data suggest that sialyltransferase activity is increased in CML granulocytes compared to normal granulocytes and that the increased enzyme activity is specific for O- linked Gal beta 1----3GaINAc. This enzyme activity may be directly responsible for the abnormal membrane sialylation and pathophysiological behavior of these cells.
Changes in hematopoietic stem cells in bone marrow of mice with Plasmodium berghei malaria
Authors: Maggio-Price L , Brookoff D , Weiss L 
Published: October 2019

Abstract
An impaired erythropoietic response to anemia has been noted in human patients with malaria and in rodents experimentally infected with Plasmodium berghei. We have attempted to characterize the erythropoietic response in mice with a fatal P berghei infection, with particular emphasis on changes in marrow hematopoietic stem cells. Mice infected with P berghei had dramatic decreases in bone marrow cellularity, erythroblasts, BFU-E, and CFU-E as early as 24 hours postinfection and before there was any change in hematocrit. With development of anemia, marrows became erythropoietic with some expansion of the CFU-E compartment, but the BFU-E pool remained depleted and reticulocyte response was inadequate. There was no significant change in CFU-S from marrows of malaria-infected mice one day after infection. The lethality of malaria infection may take three weeks to be revealed, but it may be determined within hours of the infection by the irreparable changes in marrow erythroid stem cells.
beta 2-Glycoprotein I: a plasma inhibitor of the contact activation of the intrinsic blood coagulation pathway
Authors: Schousboe I 
Published: October 2019

Abstract
The general hypothesis for the biological function of beta 2- glycoprotein I is that it neutralizes all negatively charged macromolecules that might enter the bloodstream and diminishes unwanted activation of the blood coagulation. In the present study we report that beta 2-glycoprotein I inhibits the activation of the contact phase system of the intrinsic pathway of blood coagulation. Activation was accomplished by an ellagic acid-phospholipid suspension (Cephotest) and measured by the appearance of amidolytic activity using the chromogenic substrate H-D-Pro-Phe-Arg-p-nitroanilide (S-2302). This inhibitory effect of beta 2-glycoprotein I was observed both when Cephotest was preincubated with beta 2-glycoprotein I and when the amount of beta 2- glycoprotein I in plasma was increased by addition of beta 2- glycoprotein I to either normal or beta 2-glycoprotein I-deficient plasma. The inhibitory effect of beta 2-glycoprotein I on the contact phase activation could be one of the physiological functions of this protein.
CGA-7 and HHF, two monoclonal antibodies that recognize muscle actin and react with adherent cells in human long-term bone marrow cultures
Authors: Charbord P , Gown AM , Keating A , Singer JW 
Published: October 2019

Abstract
The CGA-7, a monoclonal antibody that reacts with smooth muscle cell actin but not with endothelial cell or fibroblast actin, and HHF, a monoclonal antibody that reacts with smooth muscle, skeletal muscle, and cardiac muscle actin, both recognize microfilaments present within adherent cells from actively hematopoietic human long-term marrow cultures. Macrophages, monocytes, and cultured marrow fibroblasts do not react with either antibody. These data suggest that the anti-actin antibodies may serve as useful markers for in vitro microenvironmental cells and lend support to the hypothesis that stromal cells from long- term marrow cultures are different from marrow fibroblasts and may constitute a unique cell lineage.
Purification of eosinophil peroxidase and studies of biosynthesis and processing in human marrow cells
Authors: Olsson I , Persson AM , Stromberg K , Winqvist I , Tai PC , Spry CJ 
Published: October 2019

Abstract
Human eosinophil peroxidase (EPO) was purified from leukocytes obtained from a patient with hypereosinophilia. EPO was extracted from the granule fraction using 0.2 mol/L sodium acetate pH 4.0, and the extract was subjected to gel chromatography on Sephadex G-75 and ion exchange chromatography on Biorex 70. The mol wt calculated from gel chromatography was approximately 50,000. However, under reducing and denaturing conditions, polyacrylamide gel electrophoresis revealed two subunits with mol wt of 50,000 and 15,000. The biosynthesis of EPO was studied in marrow cells from patients with eosinophilia using labeling with (14C)-leucine, followed by immunoprecipitation with anti-EPO, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and fluorography for visualization of labeled EPO. Biosynthesis of an Mr 53,000 subunit was demonstrated. Biosynthetic labeling of the Mr 15,000 subunit was not demonstrated. A labeled Mr 25,000 chain was detected and may represent a degradation product or a chain that, after further modification, produces the Mr 15,000 subunit. Labeling was also detected in two polypeptides with mol wt of 78,000 and 72,000. These forms of EPO seem to represent precursor polypeptides subjected to proteolytic processing in a similar manner as has been reported for myeloperoxidase (MPO). However, Monensin, a proton ionophore, which blocks the processing of MPO, did not inhibit processing of EPO, indicating separate mechanisms by which MPO and EPO are directed to granules.
Half-lives of beta and gamma globin messenger RNAs and of protein synthetic capacity in cultured human reticulocytes
Authors: Ross J , Sullivan TD 
Published: October 2019

Abstract
The turnover rates of beta and gamma globin messenger RNAs and of beta and gamma globin protein synthesis in human reticulocytes have been measured. Our goal was to determine whether beta globin mRNA is significantly more stable than gamma globin mRNA during the final stages of erythroid cell maturation. Such a result could explain the reported increase in the beta-gamma protein synthetic ratio during erythroid maturation. As determined by molecular hybridization and cell- free translation assays, the half-lives of both mRNAs are 20 to 29 hours in adult and neonatal reticulocytes. Protein synthetic capacity in intact cells decays with a half-life of six to eight hours, but beta protein synthesis declines at the same rate as gamma. Therefore, the changing ratio of fetal to adult hemoglobin synthesis during late erythroid maturation does not result from differences in mRNA turnover rates or changes in translation efficiencies. These data, coupled with those obtained with immature erythroid cells (Farquhar et al, Dev Biol 85: 403, 1981), suggest that, during erythroid maturation, the gamma- beta globin protein synthesis ratio declines because gamma gene transcription ceases earlier than beta gene transcription. Our results also indicate that the protein synthetic machinery, not the quantity of mRNA, becomes rate-limiting for globin production in cultured reticulocytes.
Turnover of the methyl moiety of 5-methyltetrahydropteroylglutamic acid in the cobalamin-inactivated rat
Authors: Lumb M , Chanarin I , Perry J , Deacon R 
Published: October 2019

Abstract
The metabolism of the methyl group of 5-methyltetrahydrofolate was studied in rats in which cobalamin had been inactivated by exposure to nitrous oxide and in air-breathing control animals. Methylfolate labeled with [14C] in the methyl group and with [3H] in the pteridine- PABA portion was injected and the disappearance of [14C]H3- relative to [3H]folate was measured in liver. The half-time of the methyl group in the livers of control rats was two hours. There was no turnover of the methyl group for the first 72 hours after cobalamin inactivation. After 72 hours, there was a slow turnover of the methyl group, with a half- time of 43 hours. In control rats, it is assumed that the methyl group was metabolized by transfer to homocysteine to form methionine. In cobalamin-inactivated rats, it was shown that methylfolate was used as the substrate for forming folate polyglutamate, and analogues with 3, 4, and 5 glutamic acid residues were present. It is likely that oxidation of the methyl group by methylene tetrahydrofolate reductase occurs from folate polyglutamate containing six and seven glutamic acid residues, (Brody et al, Biochemistry 21: 276, 1982), since we were unable to demonstrate labeled methyl in longer chain analogues.
Heparin-associated thrombocytopenia: antibody binding specificity to platelet antigens
Authors: Lynch DM , Howe SE 
Published: October 2019

Abstract
Sera from four patients with heparin-associated thrombocytopenia (HAT) were evaluated by a quantitative enzyme-linked immunosorbent assay (ELISA) to detect heparin-dependent serum platelet-bindable immunoglobulin (S-PBIg) and by Western blotting and immunoprecipitation to investigate the specificity of the antibody binding. All HAT sera showed mildly increased S-PBIg (mean, 7.8 fg per platelet; normal, less than 6.0 fg per platelet) to intact target platelets in the ELISA, which was markedly increased in the presence of heparin (mean, 20.9 fg per platelet). This increase was 20-fold greater than normal control sera, which showed a mean differential increase of only 0.5 fg per platelet. Immunoglobulin binding specificity to platelet antigens was investigated using sodium dodecyl sulfate-polyacrylamide gel electrophoresis of platelet lysate with transfer of the platelet fractions onto nitrocellulose strips (Western blotting) and subsequent immunoassay using HAT and normal sera. In the presence of heparin, the four HAT patients demonstrated increased binding of immunoglobulin to platelet antigens of apparent molecular weights of 180, 124, and 82 kd. Radiolabeled heparin when incubated with HAT sera, normal sera, or albumin blanks bound to platelet proteins of the same apparent molecular weights. These observations are consistent with current hypotheses suggesting that HAT antibody is directed to heparin-platelet complexes or, alternatively, that heparin induces conformational change of antigenic sites on the platelet membrane.
Hypomethylation of DNA derived from purified human erythroid cells correlates with gene activity of the beta-globin cluster
Authors: Oppenheim A , Katzir Y , Fibach E , Goldfarb A , Rachmilewitz E 
Published: October 2019

Abstract
Analysis of methylation at the beta-globin gene cluster was carried out on DNA derived from nucleated RBCs (orthochromatic normoblasts) isolated from peripheral blood of patients with beta-thalassemia major or other congenital hemolytic anemia after splenectomy. A procedure to separate these normoblasts from the other nucleated cells of the peripheral blood was developed, providing us with a convenient source of DNA for investigating parameters related to human erythroid differentiation. Blood samples were obtained from six adult patients who express their gamma-globin genes at different levels. Inverse correlation between methylation and gene activity was consistently observed for five of the eight sites analyzed. A site 3′ to the beta gene was always unmethylated, two sites flanking the epsilon gene were always found to be methylated, and two sites 5′ to the two gamma genes, G gamma and A gamma, were hypomethylated in correlation with gamma gene activity of the individual patients. A site 5′ to the delta gene was unmethylated in normoblasts as well as in WBC. No apparent relation between hypomethylation and gene activity was observed for two additional sites. The results suggest that methylation at specific chromosomal locations participate in genetic regulation of the beta- like globin genes in humans.
Phenotypic characterization of gamma interferon-induced human monocyte polykaryons
Authors: Weinberg JB , Hobbs MM , Misukonis MA 
Published: October 2019

Abstract
Multinucleated giant cells of mononuclear phagocyte origin (monocyte or macrophage polykaryons [MPs] ) are seen in numerous different normal and pathologic states. We have previously shown that gamma interferon (IFN-gamma) induces fusion of uninuclear monocytes (UMs) to form MPs. This study was designed to characterize these IFN-gamma-induced MPs. Control and IFN-gamma-treated UMs and MPs did not have peroxidase activity, but they stained intensely for nonspecific esterase and acid phosphatase. The esterase of UMs and MPs was abolished by fluoride, but the acid phosphatase of UMs and MPs was only minimally decreased by tartrate. The phagocytosis of polystyrene spheres and glutaraldehyde- fixed erythrocytes by MPs was moderately depressed as compared with control or treated UMs, whereas the phagocytosis of IgG-coated erythrocytes was markedly depressed. Populations of control monocytes produced less H2O2 in response to 200 nmol/L of phorbol myristate acetate than did IFN-gamma-treated monocytes (37 +/- 7 v 199 +/- 29 nmol/h per milligram of cell protein). However, when examined microscopically, individual MPs had less ability to reduce NBT (18% +/- 5% positive for MP, 91% +/- 3% for treated UMs, and 67% +/- 3% for control UMs). The surface membrane antigens Leu M3, OKM1 (C3bi receptor), DU-HL60′3, DU-HL60′4, TE5, and V1 were not expressed or were expressed poorly in MPs; they were expressed normally in control and treated UMs. However, HLA-DR expression was increased in treated UMs and MPs. The binding of the lectins RCA, Con A, WGA, DBA, UEA, and PNA was equivalent in all cells. Thus, MPs formed by fusion of UMs in vitro after culture with IFN-gamma differ in several features from UMs.
Platelet binding properties of monoclonal lupus autoantibodies produced by human hybridomas
Authors: Asano T , Furie BC , Furie B 
Published: October 2019

Abstract
The platelet binding properties of human monoclonal lupus autoantibodies have been studied. These IgM autoantibodies, produced by human X human hybridomas derived from lymphocytes of patients with systemic lupus erythematosus, are known to bind to single-stranded DNA. Four anti-DNA antibodies that express the dominant 16/6 idiotype--HF2′1/17, HF2′18/2, HF2′1/13b, and HF3′16/6--bound to glutaraldehyde-fixed platelets. In contrast, HF6′21/28, HF9′11/3, and polyclonal IgM bound poorly to platelets. [35S]Methionine was incorporated into HF2′1/17, and the interaction of the intrinsically radiolabeled HF2′1/17 with fixed platelets was evaluated in a solution phase radioimmunoassay. [35S]Methionine HF2′1/17 bound to fixed platelets and could be displaced by equivalent amounts of HF2′1/17, HF2′18/2, HF2′1/13b, and HF3′16/6. HF2′1/17 bound with greater affinity to fresh platelets and to thrombin-activated platelets than to glutaraldehyde-fixed platelets. Single-stranded DNA competed with platelets for the HF2′1/17 combining site. Treatment of fresh platelets with nuclease I, trypsin, chymotrypsin, and neuraminidase did not alter the binding of antibody to the platelet surface. No binding of antibody to phospholipid micelles was observed. Purified IgM autoantibodies did not inhibit platelet aggregation induced with ADP, thrombin, or ristocetin in platelet-rich plasma. These results indicate that the human IgM monoclonal anti-DNA autoantibodies that express the dominant 16/6 idiotype are polyspecific, bind to platelets, and interact with a platelet epitope that does not appear to involve DNA, protein, or sialic acid. These antibodies interact with platelets through the same sites responsible for antibody-DNA binding.