bluuebunny/crossref_metadata_2025_split huggingface dataset:
Role of pertussis toxin-sensitive guanosine triphosphate-binding proteins in the response of erythroblasts to erythropoietin
Authors: Miller BA , Foster K , Robishaw JD , Whitfield CF , Bell L , Cheung JY 
Published: October 2019

Abstract
Human progenitor-derived erythroblasts have been recently shown to respond to erythropoietin (Epo) with an increase in intracellular free calcium concentration [Cac]. To explore the role of guanosine triphosphate (GTP)-binding proteins in mediating the rise in [Cac], single day 10 erythroid burst forming unit (BFU-E)-derived erythroblasts loaded with Fura-2 were pretreated with pertussis toxin (PT), stimulated with Epo, and [Cac] measured over 18 minutes with fluorescence microscopy coupled to digital video imaging. The [Cac] increase in day 10 erythroblasts stimulated with Epo was blocked by pretreatment with PT in a dose-dependent manner but not by heat- inactivated PT. These observations provided strong evidence that a PT- sensitive GTP-binding protein is involved. To further characterize the GTP-binding protein, day 10 erythroblast membrane preparations were solubilized, electrophoresed, and immunoblotted with antibodies specific for the known PT-sensitive G-protein subunits: the three subtypes of Gia (1,2, and 3) and Goa, Gia1 or Gia3 and Gia2 were identified but no Goa was found. To examine the influence of Epo on adenylate cyclase activity, day 10 erythroblasts were initially treated with Epo, isolated membrane preparations made, and cyclic adenosine monophosphate (cAMP) production by adenylate cyclase in membrane preparations in the presence of theophylline measured. Epo did not inhibit but significantly stimulated adenylate cyclase activity. However, the mechanism of increase of [Cac] appears to be independent of adenylate cyclase stimulation because treatment of erythroblasts with the cell-permeant dibutyryl cAMP failed to increase [Cac]. In summary, pertussis toxin blocks the increase in [Cac] in erythroblasts after Epo stimulation suggesting that this response is mediated through a pertussis toxin-sensitive GTP-binding protein. Candidate PT-sensitive GTP-binding proteins identified on day 10 erythroblasts were Gia 1, 2, or 3, but not Goa.
Differential and synergistic effects of human granulocyte-macrophage colony-stimulating factor and human granulocyte colony-stimulating factor on hematopoiesis in human long-term marrow cultures
Authors: Hogge DE , Cashman JD , Humphries RK , Eaves CJ 
Published: October 2019

Abstract
The ability of granulocyte-macrophage colony-stimulating factor (GM- CSF) and G-CSF to influence hematopoiesis in long-term cultures (LTC) of human marrow was studied by cocultivating light density normal human marrow cells with human marrow fibroblast feeders engineered by retroviral infection to constitutively produce one of these growth factors. Feeders producing stable levels of 4 ng/mL GM-CSF or 20 ng/mL G-CSF doubled the output of mature nonadherent cells. The numbers of both colony forming unit-GM (CFU-GM) and erythroid burst forming unit (BFU-E) in the G-CSF LTC were also increased (twofold and fourfold, respectively, after 5 weeks in culture), but this effect was not seen with the GM-CSF feeders. At the time of the weekly half medium change 3H-thymidine suicide assays showed primitive adherent layer progenitors in LTC to be quiescent in both the control and GM-CSF cultures. In contrast, in the G-CSF cultures, a high proportion of primitive progenitors were in S-phase. A single addition of either recombinant GM- CSF or G-CSF to LTC in doses as high as 80 ng/mL and 150 ng/mL, respectively, failed to induce primitive progenitor cycling. However, three sequential daily additions of 150 ng/mL G-CSF did stimulate primitive progenitors to enter S-phase and a single addition of 5 or 12.5 ng/mL of G-CSF together with 10 ng/mL GM-CSF was able to elicit the same effect. Thus, selective elevation of G-CSF in human LTC stimulates proliferation of primitive clonogenic progenitors, which may then proceed through to the terminal stages of granulopoiesis. In contrast, the effects of GM-CSF in this system appear limited to terminally differentiating granulopoietic cells. However, when both GM- CSF and G-CSF are provided together, otherwise biologically inactive doses show strong stimulatory activity. These findings suggest that the production of both of these growth factors by normal stromal cells may contribute to the support and proliferation of hematopoietic cells, not only in LTC, but also in the microenvironment of the marrow in vivo.
Developmental expression of mRNAs encoding platelet proteins in rat megakaryocytes
Authors: Courtney MA , Stoler MH , Marder VJ , Haidaris PJ 
Published: October 2019

Abstract
The committed bone marrow megakaryocyte (MK) progenitor undergoes a series of highly regulated stages of development resulting in a large multi-nucleated platelet-producing cell. We studied the developmental expression of the mRNA for two alpha granule proteins, fibronectin (FN) and fibrinogen gamma chain (gamma-FIB), and a cytoskeletal protein, actin, in MKs from marrow of Sprague-Dawley rats. By the method of in situ RNA:RNA hybridization, we showed that mRNAs for the alpha granule proteins were expressed most abundantly in a population of 15-microns diameter promegakaryocytes and in cells as small as 10 microns whose identity as immature MKs was inferred by positive staining for platelet- and MK-specific markers. gamma-FIB and FN mRNAs were present in reduced abundance in a small proportion of intermediate MKs; however, little or no expression was seen in mature platelet-producing MKs. In contrast, high levels of actin mRNA were expressed predominantly in mature, multi- nucleated MKs, and less abundantly in the immature forms. These results suggest that FN and gamma-FIB are transcribed early in MK development to permit translation and packaging of the protein into alpha granules, after which transcription ceases. On the other hand, transcription of actin occurs continuously throughout development, with highest levels in mature platelet-producing MKs, in which actin is needed for shape changes and intracellular movement of organelles. Our data suggest that in situ RNA:RNA hybridization for platelet-specific markers will provide additional criteria by which to establish MK lineage in immature marrow progenitors.
T-cell translocation gene 1 (Ttg-1) encodes a nuclear protein normally expressed in neural lineage cells
Authors: McGuire EA , Davis AR , Korsmeyer SJ 
Published: October 2019

Abstract
We previously identified and cloned T-cell translocation gene 1 (Ttg- 1), a putative zinc finger protein, as a result of its deregulated expression in a T-cell acute lymphoblastic leukemia cell line (RPMI 8402) with a t(11;14)(p15;q11). We have now characterized its genomic organization and identified the major transcriptional start site to lie within an initiator-like motif. Ttg-1 is normally expressed in mouse brain and not in thymus. The mouse neuroblastoma cell line, N2a, also expresses Ttg-1. Antibodies raised against a TrpE-Ttg-1 fusion protein precipitate an 18-Kd nuclear protein from metabolically labeled 8402 cells. Immunofluorescence of N2a cells shows a nuclear pattern. The two potential zinc finger domains in Ttg-1 are highly homologous to similar regions in lin-11, mec-3, and lsl-1. This data suggests that Ttg-1 may be involved in gene regulation.
Activation and proliferation signals in murine macrophages. Biochemical signals controlling the regulation of macrophage urokinase-type plasminogen activator activity by colony-stimulating factors and other agents
Authors: Hamilton JA , Vairo G , Knight KR , Cocks BG 
Published: October 2019

Abstract
Purified hematopoietic growth factors such as colony-stimulating factor- 1 (CSF-1) or macrophage CSF, granulocyte-macrophage CSF, and interleukin-3 or multi-CSF, stimulate the urokinase-type plasminogen activator (u-PA) activity of murine bone marrow-derived macrophages (BMM) and resident peritoneal macrophages. Granulocyte-CSF was inactive. The increases in BMM u-PA activity were inhibited by the glucocorticoid dexamethasone, and by agents that raise intracellular cyclic adenosine monophosphate levels, including prostaglandin E2 and cholera toxin. These changes in u-PA activity were paralleled by corresponding changes in u-PA mRNA levels. Evidence was obtained for protein kinase C and phospholipase C-mediated stimulation of BMM u-PA activity and mRNA levels; however, no evidence was found for an involvement of Na+/H+ exchange or Na+, K(+)-ATPase activity, Ca2+ fluxes, or pertussis toxin-sensitive G proteins. Several findings point to a dissociation between macrophage u-PA expression and DNA synthesis.
Evidence of a graft-versus-lymphoma effect associated with allogeneic bone marrow transplantation
Authors: Jones RJ , Ambinder RF , Piantadosi S , Santos GW 
Published: October 2019

Abstract
The existence of an immunologic antileukemia reaction associated with allogeneic bone marrow transplantation (BMT) is well established. However, a similar graft-versus-tumor effect against lymphomas has not been demonstrated. We analyzed the results of BMT in 118 consecutive patients with relapsed Hodgkin's disease or aggressive non-Hodgkin's lymphoma. The 38 patients less than 50 years of age with HLA-matched donors had allogenic marrow transplants, and the other 80 patients received purged autologous grafts. The median age was 26 years in both the allogeneic and the autologous graft recipients. The patient's response to conventional salvage therapy before transplant was the only factor that influenced the event-free survival after BMT (P less than .001). Both the patient's response to salvage therapy before BMT (P less than .001) and the type of graft (P = .02) significantly influenced the probability of relapse after BMT. The actuarial probability of relapse in patients who responded to conventional salvage therapy before BMT was only 18% after allogenic BMT compared with 46% after autologous BMT. However, the actuarial probability of event-free survival at 4 years was the same, 47% versus 41%, for patients with responsive lymphomas who received allogeneic and autologous transplants, respectively (P = .8). The beneficial antitumor effect of allogeneic BMT was offset by its higher transplant-related mortality (P = .01), largely resulting from graft-versus-host disease. Allogeneic BMT appears to induce a clinically significant graft-versus- lymphoma effect. The magnitude of this effect is similar to that reported against leukemias.
Differential redistribution of platelet glycoproteins Ib and IIb-IIIa after plasmin stimulation [published erratum appears in Blood 1991 Jul 15;78(2):545]
Authors: Cramer EM , Lu H , Caen JP , Soria C , Berndt MC , Tenza D 
Published: October 2019

Abstract
The subcellular localization of the platelet membrane receptors glycoproteins (GP) Ib and IIb/IIIa [corrected] has been studied within resting platelets by a combination of biochemical and cytochemical techniques. While both GPIb and GPIIb/IIIa are localized within the plasma membrane and surface-connected canalicular system (SCCS) membranes, only GPIIb/IIIa is present within the internal face of alpha- granular membranes. Previous studies demonstrated that plasmin can induce platelet stimulation and also decrease ristocetin-induced platelet aggregation; it was suggested that this was because of GPIb degradation by plasmin. In this study, the respective localizations of both GPIb and GPIIb/IIIa were visualized during in vitro plasmin stimulation of platelets. Generally, plasmin induced shape change, pseudopod formation, organelle centralization either with or without alpha-granule release depending on the conditions of stimulation. Plasmin treatment of platelets at 37 degrees C resulted in the disappearance of GPIb from the cell surface and its subsequent redistribution into the channels and vesicles of the SCCS with no significant modification of GPIIb/IIIa remaining on the plasma membrane. Within degranulated platelets, GPIIb/IIIa was expressed on the plasma membrane and within membranes of large vacuoles containing the alpha-granule proteins. GPIb was virtually absent from these structures and mainly restricted to the SCCS. Addition of cytochalasin D inhibited the migration of GPIb to the SCCS. Biochemical measurements confirmed that no important hydrolysis of GPIb had occurred because only very little amounts of glycocalicin were generated during the reaction. In conclusion, in plasmin-treated platelets GPIIb/IIIa is externalized to the plasma membrane while GPIb is internalized into the SCCS. Although previous studies have suggested that plasmin degrades GPIb, the reduction in ristocetin-induced aggregation may be explained by its apparent redistribution within the membranes of the SCCS.
Effects of recombinant human macrophage colony-stimulating factor on plasma cholesterol levels
Authors: Stoudemire JB , Garnick MB 
Published: October 2019

Abstract
Recombinant human macrophage colony-stimulating factor (rhM-CSF) is a hematopoietic growth factor that stimulates the growth, differentiation, proliferation, and activation of cells of the monocyte/macrophage lineage. rhM-CSF was administered to rabbits and nonhuman primates to evaluate effects on cholesterol homeostasis. Decreases in plasma cholesterol concentrations were observed during rhM- CSF administration. The observed mean (+/- SD) decreases over a range of doses in nonhuman primates receiving rhM-CSF by continuous intravenous infusion (CIVI) or intravenous bolus (IVB) injection were approximately 16% +/- 8% and 43% +/- 10%, respectively. Low-density lipoprotein (LDL) cholesterol levels decreased 55% +/- 9% from pretreatment baseline values in the animals receiving rhM-CSF by IVB. Normocholesterolemic New Zealand white rabbits receiving rhM-CSF over a range of doses by CIVI showed a decrease from baseline in total cholesterol of approximately 28% +/- 17%, with LDL cholesterol levels decreasing by approximately 72% +/- 33%, while high-density lipoprotein levels showed variable changes, including increased values. A decrease of 36% +/- 26% in total plasma cholesterol was observed in Watanabe Heritable Hyperlipidemic rabbits receiving rhM-CSF by CIVI for 7 days. This decrease was attributable almost entirely to decreases in LDL cholesterol, which fell approximately 34% +/- 24% from baseline. Although the mechanism of this cholesterol-lowering effect is unknown, these results strongly suggest that rhM-CSF may provide a novel treatment for hypercholesterolemia and may be useful in investigations into the mechanisms of cholesterol homeostasis and atherogenesis.
Aggressive peripheral T-cell lymphomas containing Epstein-Barr viral DNA: a clinicopathologic and molecular analysis
Authors: Su IJ , Hsieh HC , Lin KH , Uen WC , Kao CL , Chen CJ , Cheng AL , Kadin ME , Chen JY 
Published: October 2019

Abstract
The Epstein-Barr virus (EBV) has been shown to be associated with posttransplant lymphoma, Hodgkin's disease, and T-cell lymphoma, in addition to African Burkitt's lymphoma. In a retrospective study of 56 consecutive cases of T-cell lymphoma, EBV DNA was found by Southern blot and in situ DNA hybridization in 10 (20%) of 50 peripheral T-cell lymphomas, but in none of six cases of T-lymphoblastic lymphoma. Peripheral T-cell lymphomas containing EBV DNA could be subclassified into three categories according to histology and immunophenotypic studies: (1) T-cell lymphoma of the helper phenotype, five cases. Two cases had histologic features resembling angioimmunoblastic lymphadenopathy (AILD). (2) T-cell lymphoma of the cytotoxic/suppressor phenotype, four cases. AILD-like features could also be recognized in two cases. Reed-Sternberg-like giant cells were identified in three cases designated Hodgkin-like T-cell lymphoma. (3) Angiocentric T-cell lymphoma or lymphomatoid granulomatosis in one case, initially affecting the skin and nose; no T-cell subset could be defined. Six of the eight EBV DNA-positive patients tested for serum EBV antibodies had elevated titers of IgG antiviral capsid antigen (greater than 640) and/or early antigen (greater than 10). From combined studies of Southern blot hybridization by using EBV termini fragment probe and in situ DNA hybridization, the EBV genomes appeared to be clonotypically proliferated in the neoplastic T cells. The patients in all three groups usually had prolonged fever preceding the diagnosis, hepatosplenomegaly, an aggressive clinical course, and poor response to chemotherapy; nine died with a median survival of only 8 months. We propose that these EBV-associated aggressive T-cell lymphomas, like human T-cell leukemia/lymphoma virus-positive T-cell lymphoma, have characteristic clinicopathologic features and should be treated as a separate disease entity.
Inactivation of the retinoblastoma gene in human lymphoid neoplasms
Authors: Ginsberg AM , Raffeld M , Cossman J 
Published: October 2019

Abstract
The absence of wild type retinoblastoma (Rb) gene expression in a wide variety of human solid tumors suggests an etiologic role for this tumor suppressor gene in human cancer. We have evaluated the involvement of Rb gene inactivation in the pathogenesis and progression of human lymphoma and leukemia. We examined the genomic configuration and transcription of the Rb gene in cultured cell lines and primary cases of T- and B-cell lymphomas and leukemias. By Southern analysis, abnormalities of the Rb locus were identified in 1 of 5 T-cell acute lymphoblastic lymphoma (T-ALL) cell lines, 1 of 26 primary cases of T- ALL, 1 of 40 primary cases of chronic lymphocytic lymphoma/well- differentiated lymphoma (CLL/WDL), and 1 of 15 primary cases of intermediately differentiated lymphoma (IDL). By Northern analysis, markedly reduced or abnormal expression of the Rb gene was identified in 2 of 5 T-ALL cell lines, 1 of 7 primary cases of T-ALL, 1 of 5 primary cases of CLL/WDL, and 1 of 6 primary cases of IDL. These findings show that Rb gene inactivation can be associated with a broad range of lymphoid neoplasms and that loss of the tumor suppressor function of Rb may influence the pathogenesis and progression of lymphoma/leukemia.
Circulating erythropoietin levels after bone marrow transplantation: inappropriate response to anemia in allogeneic transplants
Authors: Beguin Y , Clemons GK , Oris R , Fillet G 
Published: October 2019

Abstract
We studied 24 recipients of autologous bone marrow transplantation (ABMT) or allogeneic BMT (BMT) to determine whether impaired erythropoietin (Epo) response to anemia could delay full erythropoietic recovery. Observed Epo levels were compared with predicted levels based on the relationship between Epo and hematocrit in 125 control subjects. Circulating Epo levels were normal during conditioning and the early posttransplant period. Between days 21 and 180, Epo levels remained normal in ABMT patients but were inappropriately low for the degree of anemia in BMT patients. Median time to full erythropoietic engraftment was longer in BMT than in ABMT recipients. Circulating Epo returned to appropriate levels after day 180, except in patients with active cytomegalovirus infection. We conclude that impaired Epo response to anemia can contribute to delayed erythropoietic recovery after allogenic BMT. Renal toxicity of ciclosporin, interaction between host and donor marrow, and cytomegalovirus infection might play a role. This study could support the use of recombinant human Epo to accelerate erythropoietic engraftment after BMT.
Detection of early human T-cell lymphotropic virus type I antibody patterns during seroconversion among transfusion recipients
Authors: Manns A , Murphy EL , Wilks R , Haynes G , Figueroa JP , Hanchard B , Barnett M , Drummond J , Waters D , Cerney M 
Published: October 2019

Abstract
From a cohort of human T-cell lymphotropic virus type I (HTLV-I) exposed transfusion recipients (N = 71) enrolled in the Jamaican Transfusion Study, 11 were selected for detailed laboratory evaluation. All recipients were followed at monthly intervals for 6 months and then bimonthly up to 1 year for evidence of HTLV-I seroconversion. Without regard to results on screening assays, pretransfusion and posttransfusion samples were tested with two licensed HTLV-1 whole- virus screening enzyme immunoassays (EIAs), recombinant EIAs for antibody against tax (p40x) and p21e envelope, standard whole virus Western blot (WB), WB enhanced with recombinant p21e, and radioimmunoprecipitation assay (RIPA). In the early period posttransfusion, antibody to gag core protein was predominant with anti- p24 generally appearing before anti-p19. Recombinant anti-p21e envelope protein, in EIA and WB format, was frequently the earliest envelope reactivity detected, while anti-gp46 in WB and anti-gp61/68 in RIPA system appeared later. Anti-tax antibodies appeared later in the time course of seroconversion. The whole-virus EIAs were less sensitive than the confirmatory assays. The combination of WB and RIPA or WB enhanced with recombinant p21e appeared equally effective in confirming samples as positive by the Public Health Service two gene group confirmatory algorithm. However, specificity of this assay approach could not be addressed in this study.
Hirudin interruption of heparin-resistant arterial thrombus formation in baboons
Authors: Kelly AB , Marzec UM , Krupski W , Bass A , Cadroy Y , Hanson SR , Harker LA 
Published: October 2019

Abstract
To determine the role of thrombin in high blood flow, platelet- dependent thrombotic and hemostatic processes we measured the relative antithrombotic and antihemostatic effects in baboons of hirudin, a highly potent and specific antithrombin, and compared the effects of heparin, an antithrombin III-dependent inhibitor of thrombin. Thrombus formation was determined in vivo using three relevant models (homologous endarterectomized aorta, collagen-coated tubing, and Dacron vascular graft) by measuring: (1) platelet deposition, using gamma camera imaging of 111In-platelets; (2) fibrin deposition, as assessed by the incorporation of circulating 125I-fibrinogen; and (3) occlusion. The continuous intravenous infusion of 1, 5, and 20 nmol/kg per minute of recombinant hirudin (desulfatohirudin) maintained constant plasma levels of 0.16 +/- 0.03, 0.79 +/- 0.44, and 3.3 +/- 0.77 mumol/mL, respectively. Hirudin interrupted platelet and fibrin deposition in a dose-dependent manner that was profound at the highest dose for all three thrombogenic surfaces and significant at the lowest dose for thrombus formation on endarterectomized aorta. Thrombotic occlusion was prevented by all doses studied. In contrast, heparin did not inhibit either platelet or fibrin deposition when administered at a dose that maximally prolonged clotting times (100 U/kg) (P greater than .1), and only intermediate effects were produced at 10-fold that dose (1,000 U/kg). Moreover, heparin did not prevent occlusion of the test segments. Hirudin inhibited platelet hemostatic function in concert with its antithrombotic effects (bleeding times were prolonged by the intermediate and higher doses). By comparison, intravenous heparin failed to affect the bleeding time at the 100 U/kg dose (P greater than .5), and only minimally prolonged the bleeding time at the 1,000 U/kg dose (P less than .05). We conclude that platelet-dependent thrombotic and hemostatic processes are thrombin-mediated and that the biologic antithrombin hirudin produces a potent, dose-dependent inhibition of arterial thrombus formation that greatly exceeds the minimal antithrombotic effects produced by heparin.