bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chemosensitivity of lymphocytes from patients with B-cell chronic lymphocytic leukemia to chlorambucil, fludarabine, and camptothecin analogs
Authors: Silber R , Degar B , Costin D , Newcomb EW , Mani M , Rosenberg CR , Morse L , Drygas JC , Canellakis ZN , Potmesil M 
Published: October 2019

Abstract
Chemosensitivity of B lymphocytes, obtained from 65 patients with B- cell chronic lymphocytic leukemia (B-CLL), Rai stages 0 through IV, was determined using the MTT assay. The results were expressed by the drug concentration required for 50% inhibition of cell viability (IC50). The cytotoxicity of chlorambucil (CLB) was compared with that of fludarabine and the DNA topoisomerase I inhibitors, camptothecin, 9- aminocamptothecin, 10,11-methylenedioxy-20(S)-camptothecin (10,11-MDC) and 9-amino-10,11-methylenedioxy-20(S)-campthothecin (9-A-10,11-MDC), and topotecan. Considerable heterogeneity in sensitivity to CLB was observed, with a median IC50 of 40.5 mumol/L in untreated patients. B- CLL cells from patients treated with CLB had a significantly higher median IC50 of 86.0 mumol/L (P < .01). Untreated as well as CLB-treated patients were divided into two subsets. For the purpose of this study, B-CLL lymphocytes with an IC50 CLB of less than 61.0 mumol/L were designated as “sensitive” and those with an IC50 CLB of > or = 61.0 mumol/L were designated as “0resistant.” After baseline assays, 15 untreated patients received CLB; after treatment, the IC50 increased in B-CLL lymphocytes from 13 of 15 patients. The response to CLB treatment, determined by its effect on the absolute lymphocyte count and by the Eastern Cooperative Oncology Group clinical criteria, was significantly better in patients whose lymphocytes had an IC50 CLB of less than 61.0 mumol/L before therapy (P < .01). B-CLL lymphocytes also had a variable degree of sensitivity in vitro to each of the other drugs. There was significant cross-resistance between CLB and fludarabine (P < 0.01). Whereas only 29% of CLB-resistant B-lymphocyte specimens obtained from individual patients were sensitive to fludarabine in vitro, 52% and 67% of CLB-resistant lymphocyte samples were sensitive to 10,11-MDC and 9-A-10,11-MDC, respectively. We have previously reported that p53 gene mutations were associated with aggressive B-CLL and a poor prognosis. B lymphocytes from seven patients with these mutations were resistant to CLB, and five of six were resistant to fludarabine. Lymphocytes from four of seven were resistant to 10,11-MDC, and three of four were resistant to 9-A-10,11- MDC. This study implies that the MTT assay may be useful in identifying subsets of CLL patients resistant to conventional chemotherapy. However, definitive conclusions can not be drawn in view of the small number of patients studied prospectively. In addition, these results suggest the potential of camptothecin-based therapy for patients unresponsive to standard treatment.
Mouse fetal liver cells lack functional amphotropic retroviral receptors
Authors: Richardson C , Ward M , Podda S , Bank A 
Published: October 2019

Abstract
We have been transducing mouse hematopoietic cells with the human MDR1 (MDR) gene in retroviral vectors to determine the optimal conditions for retroviral gene transfer as a model system for potential human gene therapy. In these studies, we have demonstrated transduction and expression of the human MDR gene using ecotropic and amphotropic MDR- retroviral producer lines. To obtain more mouse hematopoietic cells for detailed study, mouse fetal liver cells (FLC) have been used for MDR transduction and expression, and to reconstitute the ablated marrows of live adult mice. FLC contain hematopoietic cells that have a reconstituting capacity comparable to that of adult mouse bone marrow cells. However, to our surprise, FLC can only be transduced with ecotropic retrovirus and not with amphotropic virus. This restriction of transduction of FLC cannot be overcome by higher titer virus. The resistance to amphotropic transduction by FLC may be part of a changing developmental program that results in a different antigen repertoire on FLC as compared with adult bone marrow cells.
Fc-independent cross-linking of a novel platelet membrane protein by a monoclonal antibody causes platelet activation
Authors: De Reys S , Hoylaerts MF , De Ley M , Vermylen J , Deckmyn H 
Published: October 2019

Abstract
A monoclonal antiplatelet antibody (MA-13G8E1) is described that dose- dependently induces platelet aggregation and serotonin release in an Fc- independent fashion. Whereas platelets were equally aggregated by F(ab')2 fragments of this monoclonal antibody (MoAb), its Fab fragments, on the other hand, were inactive, indicating that divalent interaction is an essential requirement to induce platelet activation by MA-13G8E1. In addition, we could show that platelet epitope cross- linking by MA-13G8E1 occurred on the same platelet. MA-13G8E1 stimulated platelet phospholipase C (PLC) and induced activation of protein kinase C (PKC), both of which were almost unaffected by aspirin pretreatment. Furthermore, PLC activation appeared to be a direct antibody-mediated effect, since intracellular Ca2+ rises were not inhibited by EGTA, cytochalasin B, or aggregation-blocking MA-16N7C2 (antiglycoprotein [anti-GP]IIb/IIa). The MA-13G8E1 antigen is constitutively expressed on resting platelets of different species (7,100 +/- 800 molecules per human platelet), but not on other cell types tested. Both immunoprecipitation and affinity isolation by MA- 13G8E1 showed two low-molecular weight proteins (45 and 36 kD), having slightly acidic isoelectric pH levels (4.5 to 5.5) and forming multimolecular complexes. In conclusion, we found an MoAb that is able to induce platelet activation in an Fc-independent fashion. The mechanism involves cross-linking of a hitherto undescribed platelet membrane protein, leading to PLC and PKC stimulation.
Second primary cancers in patients continuously disease-free from Hodgkin's disease: a protective role for the spleen?
Authors: Dietrich PY , Henry-Amar M , Cosset JM , Bodis S , Bosq J , Hayat M 
Published: October 2019

Abstract
Second primary cancers are a serious late occurrence for patients surviving Hodgkin's disease (HD). In addition to previously described risk factors such as age, gender, clinical stage, and treatment modalities, splenectomy was found to correlate with an increase in risk for secondary acute leukemia. We assumed that splenic irradiation inducing functional hyposplenia and splenectomy could have similar consequences on second cancer risk. We studied a series of 892 continuously disease-free HD adult patients treated at a single institution between 1960 and 1984. The risk of second cancer was analyzed (1) relative to the general population and (2) between risk subgroups using the Cox proportional hazards model. Fifty-six patients developed a second cancer (8 acute leukemias, 3 myelodysplastic syndromes, 8 non-Hodgkin's lymphomas, and 37 solid tumors; basal cell and in situ cervix carcinomas were excluded). The 15-year cumulative incidence rate (with 95% confidence limits) was 13.2% (9.3% to 17.2%). Relative to the general population incidence data, the risk of second cancer was multiplied by 4.68 (3.51 to 6.12; P < .001); it was multiplied by 2.80 (1.63 to 4.48; P < .001) in patients whose spleen was not treated and multiplied by 6.87 (4.81 to 9.51; P < .001) in splenectomized patients or patients whose spleen was irradiated. Multivariate regression analysis that controlled for confounding variables (age, gender, clinical stage, extent of radiation therapy, and chemotherapy regimen) showed that, in addition to age above 40 years (relative risk [RR] = 3.72; P < .001), combination of MOPP chemotherapy and regional irradiation (RR = 4.99; P = .015) and combination of MOPP chemotherapy and extended irradiation (RR = 10.86; P < .001), splenic irradiation (RR = 3.67; P = .003), and splenectomy (RR = 2.54; P = .018) also significantly correlated with an increased risk. The results of this hospital-based registry study strongly suggest that splenic irradiation and splenectomy might increase the risk for treatment-related second cancer. These findings, if confirmed, have to be considered in future HD treatment policies.
Functional differences between CD38- and DR- subfractions of CD34+ bone marrow cells
Authors: Rusten LS , Jacobsen SE , Kaalhus O , Veiby OP , Funderud S , Smeland EB 
Published: October 2019

Abstract
Several studies have previously demonstrated enrichment in primitive progenitor cells in subfractions of CD34+ bone marrow (BM) cells not expressing CD38 or HLA-DR (DR) antigens. However, no studies have directly compared these two cell populations with regard to their content of primitive and more committed progenitor cells. Flow cytometric analysis of immunomagnetic isolated CD34+ cells demonstrated little overlap between CD34+CD38- and CD34+DR- progenitor subpopulations in that only 12% to 14% of total CD34+DR- and CD34+CD38- cells were double negative (CD34+CD38-DR-). Although the number of committed myeloid progenitor cells (colony-forming units granulocyte- macrophage) was reduced in both subpopulations, only CD34+CD38- cells were significantly depleted in committed erythroid progenitor cells (burst-forming units-erythroid). In single-cell assay, CD34+CD38- cells showed consistently poorer response to single as opposed to multiple hematopoietic growth factors as compared with unfractionated CD34+ cells, indicating that the CD34+CD38- subset is relatively enriched in primitive hematopoietic progenitor cells. Furthermore, CD34+CD38- and CD34+DR- cells, respectively, formed 3.2-fold and 1.6-fold more high proliferative potential colony-forming cell (HPP-CFC) colonies than did unfractionated CD34+ cells. Finally, CD34+CD38-DR- cells were depleted in HPP-CFCs as compared with CD34+CD38+DR+ cells. The results of the present study suggest that both the CD38- and DR- subfractions of CD34+ bone marrow cells are enriched in primitive hematopoietic progenitor cells, with the CD34+CD38- subpopulation being more highly enriched than CD34+DR- cells.
Structural elements influencing von Willebrand factor (vWF) binding affinity for platelet glycoprotein Ib within a dispase-digested vWF fragment
Authors: Miura S , Fujimura Y , Sugimoto M , Kawasaki T , Ikeda Y , Titani K , Yoshioka A 
Published: October 2019

Abstract
We investigated the structural elements in human von Willebrand factor (vWF) that influence binding affinity for platelet glycoprotein (GP) Ib using a dispase-digested vWF fragment as a prototype (residues Leu480/Val481-Gly718 of the vWF subunit; Andrews et al, Biochemistry 28:8326, 1989). The major structural features of this fragment are a large A1-loop formed by an intrachain disulfide bond between Cys509 and Cys695 and six O-linked sugar chains. The fragment was chemically modified by (1) reduction and S-carboxyamido-methylation (R/A), (2) desialylation (DS), or (3) a combination of both (R/A-DS). The GPIb binding affinity of these fragments was basically evaluated by competitive binding assay with anti-GPIb monoclonal antibody (LJ-Ib1), a receptor blocker for vWF (Sugimoto et al, Biochemistry 30:5202, 1991). Both the prototype and the R/A fragments were also assessed for their function in shear-induced platelet aggregation. Results unambiguously demonstrated that the presence of a disulfide bridge (Cys509-Cys695) within this domain downregulates the affinity of vWF to GPIb. In addition, it was also demonstrated that the terminal sialic acids attached to six o-linked sugar chains within this domain contribute to optimal functional modulation by the antibiotic ristocetin, but not by snake venom botrocetin.
Characterization of the human neutrophil C1q receptor and functional effects of free ligand on activated neutrophils
Authors: Eggleton P , Ghebrehiwet B , Coburn JP , Sastry KN , Zaner KS , Tauber AI 
Published: October 2019

Abstract
The partial characterization and expression of the C1q receptor (C1q-R) in relation to other complement receptors present on the surface of neutrophils has been examined, as well as the effects of free C1q on cell function. A polyclonal anti-C1q-R antibody recognizes a 68-kD neutrophil surface protein. C1q-R expression was not upregulated upon warming, priming, or exposure to FMLP, but decreased after exposure to phorbol myristate acetate (PMA), because of shedding of the receptor into the extracellular medium, as detected by enzyme-linked immunosorbent assay. CR3 and CR1 expression was upregulated from intracellular pools after cell stimulation by PMA. No evidence of intracellular pools of C1q-R was found, as assessed by immunoblotting of subcellular fractions. But C1q-R appeared to be expressed early in cell differentiation, was detected on undifferentiated HL-60 cells, and like CR3 expression, increased upon 5 days differentiation towards a neutrophil lineage. However, C1q-R expression decreased upon additional culture, whereas CR3 expression continued to increase. A large variation in the percentage of peripheral cells expressing C1q receptors in donors was observed, ranging from 13% to 100%, contrasting with CR3 receptors that exhibited less variability. Interactions between free monomeric C1q and neutrophils were also studied. Incubation of stimulated neutrophils with 10 to 100 micrograms/mL C1q resulted in a further increase in CR3 expression and adherence to albumin-coated surfaces. Staphylococci opsonized with low quantities of C1q (0.1 to 1 microgram/mL) mediated a moderate and sustained respiratory burst in neutrophils, whereas a burst of similar magnitude was generated only with free C1q at concentrations 10- to 100-fold higher. Stimulation was only partially inhibited if cells were first treated with anti-C1q-R antibody, suggesting other C1q binding proteins may be present on the cell surface. In summary, neutrophil C1q receptor is approximately 68-kD, exhibits varying expression on different subjects, and is not upregulated from intracellular stores on exposure to soluble stimuli. Stimulated, but not resting, neutrophils selectively respond to raised levels of free C1q, resulting in altered cell function and enhanced CR3 receptor expression. These studies thus suggest complex roles for C1q in neutrophil function.
Activation of Ras and formation of GAP complex during TPA-induced monocytic differentiation of HL-60 cells
Authors: Katagiri K , Hattori S , Nakamura S , Yamamoto T , Yoshida T , Katagiri T 
Published: October 2019

Abstract
In this study, it was shown that the proportion of guanosine triphosphate (GTP)-bound active Ras increased in TPA (12-o- tetradecanoyl phorbol-13-acetate)-induced monocytic differentiation of HL-60 cells. The increase of active Ras was observed at 24 hours after TPA stimulation and attained to threefold (15%) over the proportion in nontreated HL-60 cells. Herbimycin A, an inhibitor of tyrosine kinase, prevented the activation of Ras, as well as the induction of monocytic differentiation. In parallel with the activation of Ras, the proteins with molecular weights of 52, 56, 62, and 190 kD were tyrosine- phosphorylated and formed a complex with GTPase-activating protein (GAP) for Ras. In addition to the 116-kD GAP (type I GAP), the 100-kD GAP (type II GAP) molecule was markedly induced at 24 hours after TPA stimulation of HL-60 cells. These phenomena sustained for a further 24 hours during monocytic differentiation. However, they were not observed during retinoic acid-induced granulocytic differentiation of the cells. The HL-60 transfectants, which expressed a dominant inhibitory Ha-ras Asn17, showed a low level of tyrosine-phosphorylated GAP-associated proteins and did not undergo full differentiation in response to TPA. Taken together, these data indicate that the activation of Ras and GAP complex formation mutually correlate and function downstream of protein- tyrosine kinases in the signaling pathway for monocytic differentiation of HL-60 cells.
A subset of human CD34+ hematopoietic progenitors express low levels of CD4, the high-affinity receptor for human immunodeficiency virus-type 1
Authors: Zauli G , Furlini G , Vitale M , Re MC , Gibellini D , Zamai L , Visani G , Borgatti P , Capitani S , La Placa M 
Published: October 2019

Abstract
We investigated the expression of CD4 antigen in normal bone marrow (BM) samples, enriched in CD34+ hematopoietic progenitor cells. At flow cytometry, a significant fraction (ranging from 25% to 65%) of CD34+ cells also showed low levels of CD4 antigen on their surface. The CD4 receptor densities on the surface of hematopoietic progenitors was approximately 50% that of peripheral blood monocytes and 5% of peripheral blood T lymphocytes. In immunoprecipitation experiments, the CD4 antigen expressed by BM hematopoietic progenitors appeared to be the same form expressed by mature peripheral blood CD4+ cells and appeared to be a potentially functional receptor for human immunodeficiency virus-type 1, because it specifically bound recombinant envelope gp120. Moreover, BM samples, highly enriched in CD34+ cells, showed the presence of CD4 mRNA at reverse transcription- polymerase chain reaction examination. In experiments of complement- mediated cytotoxicity with Leu3-a+Leu3b anti-CD4 monoclonal antibody, a significant reduction in the number of both classes of megakaryocyte (burst-forming unit-meg [BFU-meg] and colony-forming unit-meg [CFU- meg]) and granulocyte/macrophage (CFU-GM) progenitors was observed, whereas erythroid (BFU-E) progenitors were only slightly affected. Moreover, purified CD4+ BM cells obtained by immunomagnetic selection, using high concentrations of Leu3a+Leu3b, showed a colony-forming ability of megakaryocyte and granulocyte/macrophage progenitors comparable with that of CD4- BM cells. In conclusion, the present data show that immature hematopoietic progenitor cells express low levels of CD4, the high-affinity receptor of human immunodeficiency virus-type 1.
Granulocyte colony-stimulating factor (CSF) but not interleukin-1 (IL- 1), IL-3, and granulocyte-macrophage CSF protect bone marrow progenitor cells from suppression by allosensitized cytotoxic T cells
Authors: Gerritsen WR , O'Reilly RJ 
Published: October 2019

Abstract
The major immunological reactions after an allogeneic bone marrow transplantation (BMT) are graft rejection and graft-versus-host disease (GVHD). GVHD can be prevented by T-cell depletion of the allogeneic BM graft, but the beneficial effect of T-cell depletion on the incidence of GVHD is counterbalanced by a higher incidence of graft failure. One option for the prevention of graft rejection after T-cell-depleted BM grafts is the administration of cytokines. Before applying cytokines after an allogeneic BMT, we considered it desirable to learn whether cytokines would alter the susceptibility of donor BM cells to host T cells. An in vitro assay was developed to investigate the role of the cytokines interleukin-1 (IL-1), IL-3, granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage CSF (GM-CSF) on the interaction between allosensitized, cytotoxic-T cells (CTLs) and T-cell- depleted BM cells. CTLs primed against the BM donor suppressed the formation of colonies consisting of granulocytes and macrophages (colony-forming unit GM). Colony formation was not inhibited by CTLs sensitized against a third party. Accordingly, the number of colonies scored in cocultures with CTLs sensitized to third party antigens were designated as 0% inhibition. A 66% inhibition of colony formation was observed for untreated BM cells at an effector:target (E:T) ratio of 1:1. Pretreatment of the BM cells with the cytokines G-CSF, GM-CSF, IL- 1, and IL-3 resulted in a 38% (P = .001), 53%, 66%, and 68% inhibition of colony formation, respectively, at E:T ratios of 1:1. G-CSF reduced the susceptibility of BM cells over a range from 4:1 to 1:16 (E:T ratios). GM-CSF had only significant influence at the lower E:T ratios (1:4 and 1:16). These in vitro data indicate that G-CSF could protect BM cells from killing by allosensitized CTLs and suggest that administration of these cytokines might potentially reduce the susceptibility of T-cell-depleted allogeneic BM grafts to host T-cell- mediated rejection.
Sequential administration of recombinant human interleukin-3 and granulocyte-macrophage colony-stimulating factor after autologous bone marrow transplantation for malignant lymphoma: a phase I/II multicenter study
Authors: Fay JW , Lazarus H , Herzig R , Saez R , Stevens DA , Collins RH Jr , Pineiro LA , Cooper BW , DiCesare J , Campion M 
Published: October 2019

Abstract
Preclinical studies of recombinant human interleukin-3 (rhIL-3) and granulocyte-macrophage colony-stimulating factor (rhGM-CSF) have shown enhancement of multilineage hematopoiesis when administered sequentially. This study was designed to evaluate the safety, tolerability, and biologic effects of sequential administration of rhIL- 3 and rhGM-CSF after marrow ablative cytotoxic therapy and autologous bone marrow transplantation (ABMT) for patients with malignant lymphoma. Thirty-seven patients (20 patients with non-Hodgkin's lymphoma and 17 patients with Hodgkin's disease) received one of four different treatment regimens before ABMT. Patients were entered in one of four study groups to receive rhIL-3 (2.5 or 5.0 micrograms/kg/day) administered by subcutaneous injection for either 5 or 10 days starting 4 hours after the marrow infusion. Twenty-four hours after the last dose of rhIL-3, rhGM-CSF (250 micrograms/m2/d as a 2-hour intravenous infusion) administration was initiated. rhGM-CSF was administered daily until the absolute neutrophil count (ANC) was > or = 1,500/microL for 3 consecutive days or until day 27 posttransplant. The most frequent adverse events in the trial included nausea, fever, diarrhea, mucositis, vomiting, rash, edema, chills, abdominal pain, and tachycardia. Three patients were removed from the study because of chest, skeletal, and abdominal pain felt to be probably related to study drug. Four patients died during the study period because of complications unrelated to either rhIL-3 or rhGM-CSF. The median time to recovery of neutrophils (ANC > or = 500/microL) and platelets (platelet count > or = 20,000/microL) was 14 and 15 days, respectively. There were fewer days of platelet transfusions than seen in historical control groups using rhGM-CSF, rhG-CSF, or rhIL-3 alone. In addition, there were fewer days of red blood cell transfusions compared with historical controls using no cytokines or rhGM-CSF. These data indicate that the sequential administration of rhIL-3 and rhGM-CSF after ABMT is safe and generally well-tolerated and results in rapid recovery of multilineage hematopoiesis.