bluuebunny/crossref_metadata_2025_split huggingface dataset:
Monoclonal antibodies against porcine platelet membrane glycoproteins Ib and IIb/IIIa
Authors: Takami H , Nichols WL , Kaese SE , Miller RS , Katzmann JA , Bowie EJ 
Published: October 2019

Abstract
We prepared murine monoclonal antibodies to porcine platelet membrane glycoprotein (GP) Ib and GP IIb/IIIa for further study of the porcine hemostatic mechanism. One monoclonal antibody, designated PP3–4C, blocked Ristocetin-induced platelet agglutination and caused 80% inhibition of Ristocetin-induced 125I-von Willebrand factor (vWF) binding to porcine platelets at a concentration of greater than or equal to 12 micrograms IgG/mL. PP3–4C did not affect adenosine diphosphate (ADP)- or collagen-induced platelet aggregation. Binding of 125I-Fab fragments of PP3–4C to platelets was saturable at 3.7 x 10(4) +/- 0.8 x 10(4) molecules per platelet. Another monoclonal antibody, designated PP3–3A, blocked ADP- or collagen-induced platelet aggregation at 6 micrograms IgG/mL. At a concentration of 10 micrograms IgG/mL, PP3–3A completely inhibited binding either of 125I-fibrinogen or of 125I-vWF to ADP-stimulated platelets. PP3–3A did not affect Ristocetin-induced platelet agglutination nor 125I-vWF binding to platelets in the presence of Ristocetin. Binding of 125I-Fab' fragments of PP3–3A to platelets was saturable at 9.8 x 10(4) +/- 1.2 x 10(4) molecules per platelet. PP3–4C antibody (anti-GP Ib) did not bind to human platelets; however, PP3–3A antibody (anti-GP IIb-IIIa) had partial cross-reactivity with human platelets. Immunoaffinity chromatography of solubilized surface-radiolabeled porcine platelets and subsequent sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis demonstrated that PP3–4C recognized a GP with an apparent molecular weight of 160,000 (nonreduced), and 140,000 (reduced). PP3–3A recognized GPs with apparent molecular weights of 130,000 and 80,000 (nonreduced), and 115,000 and 95,000 (reduced). These monoclonal antibodies to porcine platelet membrane GPs, which are structural and functional analogues of human GP Ib and GP IIb/IIIa, will be useful for in vitro and in vivo studies of the mammalian hemostatic mechanism.
Naturally occurring human antibodies against two distinct functional domains in the heavy chain of FXI/FXIa
Authors: De La Cadena RA , Baglia FA , Johnson CA , Wenk RE , Amernick R , Walsh PN , Colman RW 
Published: October 2019

Abstract
We have isolated and probed the mechanism of action of two naturally occurring antibodies (Baltimore and Winston-Salem) against factor XI (FXI), that developed in patients congenitally deficient in FXI after replacement therapy. Purification on immobilized protein A and neutralization with monospecific antibodies against IgG heavy and light chain subtypes indicated that both antibodies were of restricted heterogeneity. Both Winston-Salem (IgG3 kappa) and Baltimore (IgG1 kappa) completely inhibited FXI coagulant activity at titers of 200 and 8 Bethesda units, respectively. Immunoaffinity columns prepared from each antibody were able to bind the heavy but not the light chain of reduced and alkylated activated FXI (FXIa). The activation of purified FXI by activated bovine factor XII (FXIIa), a reaction independent of high molecular weight kininogen (HK), was not inhibited by either antibody. The active site on the FXIa light chain was unaffected by either patient's IgG, as measured by its amidolytic activity. In contrast, one antibody (Baltimore) or its Fab' blocked the surface- mediated proteolytic activation of FXI by human FXIIa in a concentration-dependent fashion by preventing its binding to HK, but had no effect on the rate of activation of FIX by FXIa. In contrast, the other antibody (Winston-Salem) or its Fab' inhibited the activation of FIX by FXIa in a concentration-dependent fashion but did not inhibit binding of FXI to HK. We conclude that each of these two naturally occurring antibodies is directed against a specific, separate, and distinct epitope located in the heavy chain of FXIa, one near or at the domain essential for the activation of FIX by FXIa and the other close to the domain required for binding to HK.
A comparison of phospholipid and platelets in the activation of human factor VIII by thrombin and factor Xa, and in the activation of factor X
Authors: Neuenschwander P , Jesty J 
Published: October 2019

Abstract
Two aspects of the activation of factor X by the intrinsic clotting pathway have been studied in purified human systems, in the presence of either purified phosphatidylserine:phosphatidylcholine vesicles (PS:PC) or platelets activated with ionophore A23187: (1) the activation of factor VIII by factor Xa and by thrombin, and (2) the activation of factor X by the factor IXa/VIIIa complex. Factor VIII activation by thrombin was unaffected in either rate or extent by the presence of PS:PC or activated platelets. In contrast, factor VIII activation by factor Xa required either PS:PC or platelets. The products of optimal factor VIII activation by the two enzymes, designated factor VIIIa(T) and factor VIIIa(Xa), are kinetically different in the activation of factor X by factor IXa, factor VIIIa(T) being approximately twice as active (in factor X activation) as factor VIIIa(Xa) in the presence of PS:PC or platelets. Factor VIIIa(Xa) can be converted to the more active VIIIa(T) by thrombin treatment, but the activity of factor VIIIa(T) is unchanged by factor Xa treatment. Factor X activation was also studied with optimally activated factor VIIIa(T), in the presence of PS:PC or activated platelets, as a function of factor IXa concentration in order to determine the apparent dissociation constant for the factor IXa-VIIIa interaction in the two cases. Activated platelets increased the apparent affinity more than fivefold.
Use of synthetic oligonucleotides in the characterization of antithrombin III Northwick Park (393 CGT----TGT) and antithrombin III Glasgow (393 CGT----CAT)
Authors: Thein SL , Lane DA 
Published: October 2019

Abstract
Antithrombin III (ATIII) Northwick Park is caused by a single amino acid substitution, Arg 393---Cys and antithrombin III Glasgow is caused by Arg 393----His. Examination of the genetic code and the sequence of normal antithrombin III revealed that these amino acid substitutions could arise from the substitution of either two nucleotides or a single nucleotide at codon 393 of the antithrombin III gene. In two families, detection of the ATIII variants by genetic linkage analysis was not possible owing to lack of informative RFLP markers. Consequently, we synthesized two 22-base-long oligonucleotides specific for the single- base substitutions in the region of codon 393 and demonstrated by oligonucleotide hybridization that the molecular defect of ATIII Northwick Park is caused by the CGT----TGT mutation at codon 393 and that ATIII Glasgow is caused by the CGT----CAT mutation at codon 393. These oligonucleotide probes should prove useful as an alternative method for early detection of the ATIII variants.
A multicenter trial of antithymocyte globulin in aplastic anemia and related diseases
Authors: Young N , Griffith P , Brittain E , Elfenbein G , Gardner F , Huang A , Harmon D , Hewlett J , Fay J , Mangan K 
Published: October 2019

Abstract
One hundred fifty patients with bone marrow failure were treated in three groups with antithymocyte globulin (ATG; Upjohn, Kalamazoo, MI) in a multicenter trial. Patients were assessed at 3, 6, and 12 months after initiation of treatment by three criteria: transfusion independence, clinical improvement, and blood counts. Group I consisted of 77 patients with acute severe aplastic anemia, randomized to receive either ten or 28 days of ATG. There was no significant difference between the two arms of this protocol: 47% of all patients were clinically improved and 31% were transfusion independent at 3 months. Of the severely affected patients, 27% died before 3 months; most deaths occurred early in treatment. Factors associated with survival in severely affected patients included male sex, age less than 40 years, absolute neutrophil count greater than 200/microL, and idiopathic etiology. Neutrophil counts generally increased by 8 weeks after treatment, but patients continued to show improvement to 1 year posttreatment. In Group II, 44 patients with moderate or chronic severe aplastic anemia were randomized to receive either ten days of ATG or 3 months of high-dose nandrolone decanoate. No patient initially treated with androgens recovered, but 28% of ATG-treated cases achieved transfusion independence at 3 months. Group III consisted of patients with a variety of bone marrow failure syndromes. Patients with pancytopenia and cellular bone marrow showed response rates similar to those of patients with chronic or moderate aplastic anemia.
In vivo hematopoietic effects of tumor necrosis factor-alpha in normal and erythroleukemic mice: characterization and therapeutic applications
Authors: Johnson CS , Chang MJ , Furmanski P 
Published: October 2019

Abstract
The effects of recombinant, macrophage-derived, murine tumor necrosis factor-alpha (TNF-alpha) on hematopoiesis in vivo has been examined in normal mice and in Friend virus (FV)-induced erythroleukemic mice. Intravenous (IV) administration of a single dose of recombinant murine TNF-alpha (10(5) U per mouse) significantly suppressed normal and leukemic late-stage erythropoiesis as measured by numbers of mature erythroid colony forming cells (CFU-E) in the bone marrow and spleen and by peripheral blood reticulocyte counts. In normal animals, the immature erythroid (BFU-E), macrophage (CFU-M), and granulocyte- macrophage (CFU-GM) compartments were significantly stimulated by TNF- alpha in both the bone marrow and the spleen. In the bone marrow of leukemic mice, the BFU-E, CFU-GM, and CFU-M progenitor cell compartments were also stimulated by treatment with the monokine. In the spleens of leukemic mice (the primary site of FV leukemia cell accumulation), relative numbers of BFU-E and CFU-GM were increased by TNF-alpha, while those of CFU-M were suppressed. TNF-alpha caused a rapid decrease in the markedly elevated spleen weights of progressively leukemic mice, and in multiple doses it caused complete clinical disease regression in a significant percentage of leukemic animals. The combination of TNF-alpha with interferon-gamma (IFN-gamma) increased the incidence of leukemia regression, compared with TNF-alpha alone. These results show that TNF-alpha exerts a suppressive influence on late-stage erythropoiesis in vivo and suggest that this effect might be exploited in the treatment of acute erythroleukemia, erythroid hyperplasias, and related diseases.
Growth regulation of human acute myeloid leukemia: effects of five recombinant hematopoietic factors in a serum-free culture system
Authors: Delwel R , Salem M , Pellens C , Dorssers L , Wagemaker G , Clark S , Lowenberg B 
Published: October 2019

Abstract
The response of human acute myeloid leukemia (AML) cells to the distinct hematopoietic growth factors (HGFs), ie, recombinant interleukin-3 (IL-3), granulocyte-macrophage-CSF (GM-CSF), granulocyte- CSF (G-CSF), macrophage-CSF (M-CSF), and erythropoietin (Epo) was investigated under well-defined serum-free conditions. Proliferative responses to these factors, when added separately as well as in combinations, were analyzed in 25 cases of human AML using 3H-thymidine incorporation and colony assays. The 3H-thymidine uptake data revealed that IL-3, GM-CSF, G-CSF, and M-CSF were stimulators of AML proliferation in 19, 15, 13, and 4 cases, respectively. Epo only stimulated DNA synthesis in the cells of the single erythroleukemia case. GM-CSF stimulation was seen only in IL-3 reactive cases and GM- CSF, when combined with IL-3, could not further elevate the DNA synthesis evoked by IL-3 alone. On the other hand, in six cases, G-CSF enhanced the IL-3- or GM-CSF-stimulated thymidine uptake. These results suggest that subpopulations of AML cells that are activated by distinct CSFs (eg, IL-3/GM-CSF-responsive cells and G-CSF-responsive cells) coexist. The 3H-thymidine incorporation assay was more sensitive for measuring CSF responses than methylcellulose colony cultures, since activation of DNA synthesis was more frequently seen than induction of colony formation. DNA synthesis experiments revealed eight different CSF response patterns among these 25 cases. CSF phenotyping may be a useful addition to the morphologic classification of AML, since these patterns directly reflect the ability of the proliferating subsets of AML cells to respond to the CSFs.
Orientation and specificity of fibrin protofibril binding to ADP- stimulated platelets
Authors: Lewis JC , Johnson C , Ramsamooj P , Hantgan RR 
Published: October 2019

Abstract
We have investigated the molecular basis of platelet:fibrin binding by studying interactions between platelets and protofibrils, soluble two- stranded polymers of fibrin, which are intermediates on the fibrin assembly pathway. The specificity of these interactions was examined with transmission electron microscopy (TEM), which clearly showed thin fibers with lengths to 150 nm attached to the cell surface of normal, stimulated platelets. Immunogold electron microscopy using rabbit anti- human fibrinogen as the first stage antibody verified the identity of the surface-bound molecules, and the immunogold distribution paralleled that observed with the fibrin/fibrinogen molecules alone. Contacts between the ends of the fibers and the platelets were frequently observed, but lateral contacts were also evident. Given the diameter at the point of fibrin contact (18.2 +/- 1.3 nm), it is possible that several glycoprotein receptors were involved in binding each protofibril. Morphometric analyses demonstrated that normal platelets stimulated by ADP in the absence of exogenous fibrin(ogen) or in the presence of fibrin protofibrils and antibodies directed against the GPIIb/IIIa complex lacked this molecular layer on the surface. Neither protofibrils nor fibrin fibers adhered to the surface of Glanzmann's thrombasthenic platelets, as demonstrated by TEM and microfluorimetry. Synthetic peptides of sequence RGDS and HHLGGAKQAGDV effectively blocked the binding of protofibrils to the surface of normal, stimulated platelets while synthetic GHRP had no effect. These results provide direct evidence for multiple points of attachment between fibrin protofibrils and the glycoprotein IIb/IIIa complexes present in a functional conformation on the surface of normal, stimulated platelets.
Synergistic factors for stem cell proliferation: further studies of the target stem cells and the mechanism of stimulation by interleukin-1, interleukin-6, and granulocyte colony-stimulating factor
Authors: Ikebuchi K , Ihle JN , Hirai Y , Wong GG , Clark SC , Ogawa M 
Published: October 2019

Abstract
Serial observations of blast cell colony development from spleen cells of mice treated with 5-fluorouracil (5-FU) four days earlier revealed that either form of human interleukin-1 (IL-1 alpha or IL-1 beta) hastens the emergence of interleukin-3 (IL-3)-dependent blast cell colonies. This activity was essentially indistinguishable from the effect of interleukin-6 (IL-6) or granulocyte colony-stimulating factor (G-CSF) in the same system, an effect that we have ascribed previously to a shortening of the G0 period of the dormant stem cells. We also analyzed the time courses of colony formation from cultures of day-2 post-5-FU marrow cells supported by IL-1 alpha, IL-6, or G-CSF alone or in combination with IL-3. In the presence of IL-3, G-CSF and IL-6 but not IL-1 alpha hastened the development of colonies and increased the numbers of multilineage colonies relative to cultures of IL-3 alone. This observation, together with our previous data from the human system, suggests that the synergistic effect of IL-1 is likely due to induction of secondary growth factors, including IL-6 and G-CSF, by accessory cells in culture. The effect of IL-6 on G0 was confirmed by analysis of the cycling status of progenitor cells in short-term culture. While neither IL-3 nor IL-6 alone had any effect on the cycling status, the combination of factors resulted in a rapid recruitment of quiescent cells into cell cycle (within 48 hours) as represented by a twofold increase in the numbers of multipotential progenitors and a significant increase in the sensitivity of these cells to 3H-thymidine with high specific activity. Combinational testing of all of these synergistic factors revealed that the target cell populations for the IL-1, IL-6, and G-CSF overlap considerably, suggesting that they all may act through a common mechanism. This is further supported by our finding that cells from blast cell colonies grown in the presence of a combination of any one of the synergistic factors with IL-3 replate with higher efficiency and yield more multilineage secondary colonies than those from colonies grown in IL-3 alone. These findings provide further evidence that IL-1, IL-6, and G- CSF serve to integrate the immediate host responses to infection through augmentation of effector cells and antibody production as well as the longer term host responses by recruitment of dormant hemopoietic stem cells into active cell cycling.
The limited importance of factor Xa inhibition to the anticoagulant property of heparin in thromboplastin-activated plasma
Authors: Pieters J , Lindhout T 
Published: October 2019

Abstract
The antifactor Xa activities of heparin fractions are widely used as an ex vivo index of their antithrombotic efficacy. Its clinical meaning, however, remains speculative. In the study reported, we measured the effects of standard heparin, a synthetic pentasaccharide heparin (antifactor Xa activity only), and a low molecular weight heparin (LMWH) on factor Xa, factor Va, and thrombin generation in thromboplastin-activated plasma. We clearly demonstrated that the antifactor Xa activity of heparin contributed little in its anticoagulant activity. The inhibition of factor Va generation, dependent on the heparin antithrombin activity only, is of prime importance to the inhibition of thrombin generation in plasma. The inhibition of thrombin generation by the LMWH was comparable with that of standard heparin on the basis of their respective antithrombin specific activities, but not on the basis of their antifactor Xa activities.
Dual role of fibronectin in hematopoietic differentiation
Authors: Weinstein R , Riordan MA , Wenc K , Kreczko S , Zhou M , Dainiak N 
Published: October 2019

Abstract
The adhesive glycoprotein fibronectin provides anchorage for fibroblasts and hematopoietic progenitor cells in vitro. Fibronectin also demonstrates growth factor activity for fibroblasts; however, there is no available information regarding its role as a hematopoietic growth factor. To distinguish growth factor activity of fibronectin from its anchorage activity for hematopoietic progenitors, we assessed the ability of purified human plasma fibronectin to promote human bone marrow erythroid, granulocyte-macrophage (GM) and mixed granulocyte- erythroid-macrophage-megakaryocyte (GEMM) colony formation in liquid suspension, methylcellulose, and fibrin clots under serum-free conditions. Addition of fibronectin to methylcellulose cultures, or to cultures formed in fibrin clots, using fibrinogen depleted of fibronectin by preadsorption over gelatin-Sepharose and clotted with thrombin, resulted in up to a twofold enhancement of proliferation of erythroid burst-forming units (BFU-E), erythroid colony-forming units (CFU-E), and CFU-GEMM. This effect was concentration-dependent up to a fibronectin supplement of 100 micrograms/mL. By contrast, CFU-GM proliferation was not affected by the addition of fibronectin to the cultures. Fibronectin-adherent marrow cells overlaid with liquid medium formed both early and late-appearing erythroid colonies, whereas similarly cultured plastic-adherent marrow cells did not. Erythroid colony formation was observed in cultures of fibronectin-adherent marrow cells overlaid with methylcellulose but not in cultures of plastic-adherent marrow cells under the same conditions. Finally, the erythroid growth-promoting activity of fibronectin was inhibited by arginyl-glycyl-aspartyl-serine (RGDS), a tetrapeptide that competitively blocks the interaction of fibronectin with its receptor. We conclude that fibronectin plays a dual role in hematopoiesis: providing (a) anchorage for erythroid and primitive progenitors, and (b) as a proliferative stimulus for these hematopoietic cells. Both activities may be mediated by the cell adhesion domain of the molecule.
Treatment of aggressive multiple myeloma by high-dose chemotherapy and total body irradiation followed by blood stem cells autologous graft
Authors: Fermand JP , Levy Y , Gerota J , Benbunan M , Cosset JM , Castaigne S , Seligmann M , Brouet JC 
Published: October 2019

Abstract
Eight patients with stage III aggressive multiple myeloma, refractory to current chemotherapy in six cases, were treated by high-dose chemotherapy (nitrosourea, etoposide, and melphalan) (HDC) and total body irradiation (TBI), followed by autografting with blood stem cells. These cells were previously collected by leukapheresis performed during hematologic recovery following cytotoxic drug-induced bone marrow aplasia. Seven patients were alive 9 to 17 months after HDC-TBI and graft. One died at day 40 from cerebral bleeding. All living patients achieved a 90% or greater reduction in tumor mass. In two cases, a complete remission (CR) has persisted at a follow-up of 15 and 16 months. Three patients have been well and off therapy with stable minimal residual disease (RD) since 10, 11, and 17 months, respectively. A patient in apparent CR and another with RD have relapsed 9 to 12 months posttreatment. Autologous blood-derived hematopoietic stem cells induced successful and sustained engraftment in all living patients. These results, although still preliminary, indicate that HDC and TBI, followed by blood stem cells autograft, which has both practical and theoretical interest over allogeneic or autologous bone marrow transplantation, deserve consideration in selected patients with multiple myeloma.
Prognostic impact of cytogenetic abnormalities in patients with de novo acute nonlymphocytic leukemia
Authors: Schiffer CA , Lee EJ , Tomiyasu T , Wiernik PH , Testa JR 
Published: October 2019

Abstract
Detailed cytogenetic analyses were performed on specimens from 198 patients with de novo acute nonlymphocytic leukemia (ANLL), including high-resolution banding studies in 79 patients. One hundred ninety-two patients received induction therapy with daunorubicin and cytosine arabinoside (Ara-C) with an overall complete response rate (CR) of 63%. Responding patients received repetitive cycles of Ara-C-based intensification therapy. Clonal abnormalities were detected in 69% of the patients with specimens adequate for cytogenetic analysis. Certain cytogenetic changes were closely associated with French-American- British (FAB) morphology, age, and outcome: t(8;21) (closely associated with FAB M2), t(15;17) (associated with FAB M3), and abn 16q22 (associated with FAB M4EOS) tended to occur in younger patients and were associated with favorable outcomes in terms of both CR rate and long-term disease-free survival. In contrast, 19% of patients who had - 5/5q- and or -7/7q- and seven patients with trisomy 8 were older, had a poor prognosis, and usually failed to achieve remission (CR) because of chemotherapy-resistant leukemia. The adverse effect on CR rate and duration in this group of patients was independent of age, and there was no association with particular morphologic subtypes. These data suggest that cytogenetic findings should influence future therapeutic choices. In particular, patients with abnormalities associated with poor responses may be considered for investigational approaches and may also provide insights into mechanisms of drug resistance.