bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cytochalasin D and E: effects on fibrinogen receptor movement and cytoskeletal reorganization in fully spread, surface-activated platelets: a correlative light and electron microscopic investigation
Authors: Olorundare OE , Simmons SR , Albrecht RM 
Published: October 2019

Abstract
This study investigates the involvement of actin microfilaments in fibrinogen receptor redistribution and cytoskeletal reorganization that takes place in fully spread, surface-activated platelets. Colloidal gold-labeled fibrinogen (Fgn-Au label) in conjunction with video- enhanced differential interference contrast light microscopy (VDIC) was used to identify fibrinogen binding sites, glycoprotein IIb/IIIb (GPIIb/IIIa), on fully spread platelets. Platelets were treated with cytochalasins D and E (5 x 10(-5) mol/L to 5 x 10(-8) mol/L) for 10 minutes, before or after incubation with Fgn-Au label. Results observed with VDIC were subsequently confirmed by high-voltage transmission and low voltage-high resolution scanning electron microscopic examination of the specimens. Preincubation of activated platelets with cytochalasin D or E (5 x 10(-5) and 5 x 10(-6) mol/L) inhibited fibrinogen receptor redistribution and abolished cytoskeletal reorganization in fully spread platelets. After surface-activated platelets were incubated with Fgn-Au label, treatment with the above concentrations of cytochalasin D or E disrupted cytoskeletal reorganization and caused random movement of previously redistributed receptor-ligand complexes. Incubation of platelets with cytochalasin E 5 x 10(-6) mol/L prevented platelet activation and spreading. Thus, actin filaments appear necessary for platelet spreading from the discoid to the fully spread stage. The ligand-triggered, cytoskeletally directed movement of fibrinogen receptors in fully spread platelets appears to be dependent on the presence of intact, polymerized actin. This movement is distinct from the cytochalasin-insensitive accumulation of GPIIb/IIIa-ligand in the channels of the open canalicular system.
Expression of receptors for granulocyte colony-stimulating factor on neutrophils from patients with severe congenital neutropenia and cyclic neutropenia
Authors: Kyas U , Pietsch T , Welte K 
Published: October 2019

Abstract
We studied granulocyte colony-stimulating factor (G-CSF) binding sites on neutrophils from patients with severe congenital neutropenia (SCN; Kostmann-syndrome) and cyclic neutropenia (CN) during treatment with recombinant human (rh) G-CSF. G-CSF receptor expression was measured by scatchard analysis. Neutrophils from six healthy controls expressed between 480 and 1,210 binding sites per cell, whereas neutrophils from five SCN patients expressed increased numbers of G-CSF binding sites ranging between 2,100 and 3,900 per cell. Neutrophils from four patients with CN expressed 350 to 1,600 binding sites per cell. The affinity of rhG-CSF to its receptor was similar in patients and controls. These data suggest that SCN patients and CN patients are not defective in G-CSF receptor expression as judged by the numbers of G- CSF binding sites and binding affinity; however, we cannot exclude defects in parts of the G-CSF receptor that may be involved in the signal transduction pathway.
Cardiopulmonary bypass induces leukocyte-platelet adhesion
Authors: Rinder CS , Bonan JL , Rinder HM , Mathew J , Hines R , Smith BR 
Published: October 2019

Abstract
Cardiopulmonary bypass (CPB) has been demonstrated to activate platelets, producing an increased number of circulating platelets that have undergone alpha-granule release and express granule membrane protein-140 (GMP-140) on their surface. In vitro, GMP-140 mediates activated platelet adhesion to neutrophils (PMN) and monocytes, causing the formation of leukocyte-platelet conjugates. Using a newly developed assay that measures the percentage of circulating leukocyte-platelet conjugates in whole blood, we studied 17 patients undergoing CPB and have determined that (1) monocyte-platelet conjugates increased significantly during CPB, from 18% +/- 1.5% to 44% +/- 4.5% (mean +/- SEM) by the end of CPB, while PMN-platelet conjugates increased only slightly and lymphocyte-platelet conjugates decreased; (2) the time course of the increase in monocyte- and PMN-platelet conjugates paralleled that of the increase in circulating activated platelets, as determined by the presence of surface GMP-140; and (3) monocyte activation, as assessed by increased surface expression of CD11b, showed a gradual increase similar to the increase in monocyte-platelet conjugates, while PMN surface CD11b peaked immediately after the start of CPB. We conclude that CPB, through increased platelet GMP-140 expression, causes formation of monocyte-platelet, and to a lesser extent, PMN-platelet conjugates. The activation of monocytes and PMN on CPB, as evidenced by CD11b expression, occurs with differing time courses.
Thrombolytic properties of Desmodus rotundus (vampire bat) salivary plasminogen activator in experimental pulmonary embolism in rats
Authors: Witt W , Baldus B , Bringmann P , Cashion L , Donner P , Schleuning WD 
Published: October 2019

Abstract
rDSPA alpha 1 (recombinant Desmodus salivary plasminogen activator alpha 1) is a recombinant protein corresponding to a natural plasminogen activator from the vampire bat Desmodus rotundus. The thrombolytic properties of rDSPA alpha 1 and tissue-type plasminogen activator (t-PA) were compared in a rat model of pulmonary embolism. Whole blood clots, produced in vitro and labeled with 125I-fibrinogen, were embolized into the lungs of anesthetized rats. Thrombolysis was calculated from the difference between initial clot radioactivity and that remaining in the lungs at 60 minutes. Blood was sampled for gamma counting, measurement of hemostatic factors, and plasminogen activator antigen levels. Thrombolysis at 3, 10, 30, and 100 nmol/kg intravenously (10% bolus, 90% over 60 minutes) amounted to 30% +/- 2%, 51% +/- 4%, 85% +/- 4%, 98% +/- 0% for rDSPA alpha 1 and 30% +/- 3%, 41% +/- 3%, 57% +/- 6%, 93% +/- 2% for t-PA (controls: 29% +/- 2%; mean +/- SEM, n greater than or equal to 6). t-PA at 100 nmol/kg significantly decreased fibrinogen, plasminogen, and alpha 2- antiplasmin levels by 33% +/- 7%, 38% +/- 8%, and 61% +/- 9%, whereas rDSPA alpha 1 at 100 nmol/kg only lowered alpha 2-antiplasmin significantly (by 29% +/- 6%). Compared with t-PA, rDSPA alpha 1 is the more potent and more clot selective (fibrin specific) thrombolytic agent. These results suggest that rDSPA alpha 1 may be safer and more efficacious than currently used thrombolytics.
Inhibition of normal B-cell function by human immunodeficiency virus envelope glycoprotein, gp120
Authors: Chirmule N , Oyaizu N , Kalyanaraman VS , Pahwa S 
Published: October 2019

Abstract
Despite the occurrence of hypergammaglobulinemia in human immunodeficiency virus (HIV) infection, specific antibody production and in vitro B-cell differentiation responses are frequently impaired. In this study, we have examined the effects of HIV envelope glycoprotein gp120 on T-helper cell function for B cells. In the culture system used, B-cell functional responses were dependent on T-B- cell contact, since separation of T and B cells in double chambers by Transwell membranes rendered the B cells unresponsive in assays of antigen-induced B-cell proliferation and differentiation. Cytokines secreted by T cells were also essential, since anti-CD3 monoclonal antibody (mAb)-activated, paraformaldehyde-fixed T-cell clones failed to induce B-cell proliferation and differentiation. Pretreatment of the CD4+ antigen-specific T cells with gp120 was found to impair their ability to help autologous B cells, as determined by B-cell proliferation, polyclonal IgG secretion, and antigen-specific IgG secretion. The gp120-induced inhibition was specific in that it was blocked by soluble CD4. Furthermore, only fractionated small B cells (which are T-cell-dependent in their function) manifested impaired responses when cultured with gp120-treated T cells. Antigen-induced interleukin (IL)-2 and IL-4, but not IL-6, secretion were markedly reduced in gp120-treated T-cell clones. Addition of exogenous cytokines failed to compensate for defective helper function of gp120-treated T cells. The findings in this study indicate that gp120 impairs helper functions of CD4+ T cells by interfering with T-B-cell contact- dependent interaction; the inhibitory effects of soluble envelope proteins of HIV may contribute to the immunopathogenesis of the HIV- associated disease manifestations.
An animal model of allogeneic donor platelet refractoriness: the effect of the time of leukodepletion
Authors: Blajchman MA , Bardossy L , Carmen RA , Goldman M , Heddle NM , Singal DP 
Published: October 2019

Abstract
Approximately 50% of multi-transfused individuals become refractory to random donor platelets. Recent clinical data suggest that those patients receiving leukocyte-depleted blood products are less likely to become refractory to random donor platelets than recipients of non- leukocyte-depleted products. Leukocyte depletion can be performed immediately after collection of a unit of whole blood before its storage (prestorage leukodepletion) or just before the transfusion of the blood product to a recipient, after its storage (poststorage leukodepletion). However, the most appropriate time for the leukodepletion of blood products has not been established. The present study was undertaken to establish an animal model of allogeneic platelet refractoriness, and to compare the effect of prestorage and poststorage leukodepletion on the frequency of refractoriness to allogeneic donor platelets. In this model, two strains of rabbits were used: California Black rabbits were used as blood donors, while New Zealand White rabbits were used as recipients. Eight weekly infusions of nonleukodepleted allogeneic fresh blood resulted in an allogeneic platelet refractory rate of 91.2% (31/34). The prestorage leukodepletion of the donor blood was associated with a significantly higher allogeneic platelet survival and lower refractory rate (33.3%) to allogeneic platelets than poststorage leukodepletion (66.7%). Furthermore, the data suggest that cell-free plasma products are capable of inducing refractoriness to allogeneic donor platelets; the stored plasma having a greater likelihood of inducing such refractoriness than fresh plasma. Thus, these data provide evidence that the prestorage leukodepletion of allogeneic donor blood is associated with a lower frequency of refractoriness and better allogeneic platelet survival than poststorage leukodepletion.
High expression of the mdr3 multidrug-resistance gene in advanced-stage chronic lymphocytic leukemia
Authors: Sonneveld P , Nooter K , Burghouts JT , Herweijer H , Adriaansen HJ , van Dongen JJ 
Published: October 2019

Abstract
Chronic lymphocytic leukemia (CLL) is characterized by an often indolent course with a poor therapeutic response at advanced stage. We investigated the expression of the human multidrug resistance genes mdr1 and mdr3 in 31 patients with CLL. Using specific probes for mdr1 and mdr3 mRNA, respectively, expression of both genes could be found in 29 of 31 patients. Of those, nine had high expression of mdr1 and 13 of mdr3. Although 29 of 31 patients showed coexpression of mdr1 and mdr3, the mRNA levels were not interrelated. Prior treatment did not significantly influence the level of mdr1 or mdr3 expression. In patients with advanced CLL (Rai stage 3 + 4) the mdr3 expression was significantly higher than in early-stage CLL (Rai stage 0 to 2) (mean +/- SEM, 25.4 +/- 4.2 U v 4.2 +/- 1.1 U; P less than .0001). Such a difference was not present for mdr1 expression (21.5 +/- 4.3 U v 10.7 +/- 3.1 U; P = .09). These data indicate that advanced-stage CLL is associated with an increased mdr3 expression, which may concur with a decreased sensitivity to chemotherapy.
Interferon system in primary acute lymphocytic leukemia cells with or without deletions of the alpha-/beta-interferon genes
Authors: Grander D , Heyman M , Brondum-Nielsen K , Liu Y , Lundgren E , Soderhall S , Einhorn S 
Published: October 2019

Abstract
Various aspects of the interferon (IFN) system were studied in malignant cells from 37 unselected patients with acute lymphocytic leukemia (ALL). It was found that leukemic cells from two of 37 patients had a complete loss of alpha- and beta-IFN genes, whereas cells from four of 37 had lost one of the alpha-/beta-IFN alleles. In 25 cases, viable cells were also available for functional studies. Cell clones with loss of one of the alpha-/beta-IFN alleles produced low amounts of IFN after virus induction in vitro. Some clones with an apparently normal set of IFN genes were unable to produce detectable amounts of IFN. All clones studied were found to carry high-affinity alpha-IFN receptors. In clones carrying deletions of IFN genes, the cells were sensitive to IFN in vitro as measured by alpha-IFN-induced enhancement of 2′,5′-oligoadenylate synthetase (2′,5′-A synthetase). Cells from four patients with an apparently normal set of IFN genes were insensitive to this effect of IFN. We conclude that of the 17 patients in which IFN genes, IFN production, alpha-IFN receptors, and IFN-induced enhancement of 2′,5′-A synthetase were studied, nine (53%) showed some abnormality in their IFN system. This finding may add some support to the hypothesis that defects in the IFN system could be a step on the path to malignant transformation in ALL. Moreover, patients whose malignant cells carry IFN gene deletions or other defects in their IFN-producing capacity, but are still sensitive to exogenous IFN, could represent a subgroup of ALL with a greater likelihood of responding to IFN therapy.
Hematopoietic growth factors released by marrow stromal cells from patients with aplastic anemia
Authors: Kojima S , Matsuyama T , Kodera Y 
Published: October 2019

Abstract
We studied the production of granulocyte colony-stimulating factor (G- CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), and interleukin-6 (IL-6) by stromal cells from 33 patients with aplastic anemia (AA). Complete, confluent stromal layers were produced by 29 of the 33 samples using the long-term bone marrow culture (LTBMC) system. The concentration of G-CSF, GM-CSF, and IL-6 in culture media with or without interleukin-1 (IL-1) stimulation was determined by an enzyme- linked immunoadsorbent assay (ELISA). The spontaneous production of G- CSF, GM-CSF, and IL-6 did not differ significantly between normal controls and the patients with AA. The ability of stromal cells to release the three hematopoietic growth factors in response to IL-1 was either normal or elevated in all but one patient. We also studied the change in production of G-CSF, GM-CSF, and IL-6 by stromal cells before and after antilymphocyte globulin (ALG) therapy in 16 patients with AA. There was no correlation between the change in production of these cytokines and the response to ALG. In contrast to previous studies that showed a defect in the production of hematopoietic growth factors by stromal cells from patients with AA, the results indicated a normal or elevated production of G-CSF, GM-CSF, and IL-6 by marrow stromal cells in patients with AA.
Granulocyte-macrophage colony-stimulating factor-induced antibody- dependent cellular cytotoxicity in bone marrow macrophages: application in bone marrow transplantation
Authors: Charak BS , Agah R , Mazumder A 
Published: October 2019

Abstract
Granulocyte-macrophage colony-stimulating factor (GM-CSF) has been reported to induce antitumor activity in peripheral blood monocytes. We examined the role of GM-CSF on bone marrow (BM) macrophages in inducing antibody-dependent cellular cytotoxicity (ADCC) against murine and human tumor cells in vitro and in vivo with the aim of applying this approach in an autologous bone marrow transplantation (BMT) setting. GM- CSF induced a potent ADCC in BM macrophages against a murine melanoma in vitro. Treatment with GM-CSF alone or with antibody alone had no effect, whereas therapy with combination of both these agents resulted in a significant reduction in dissemination of melanoma both in a nontransplant as well as in BMT settings, with results being more optimal in the latter setting. Adoptive transfer of BM macrophages harvested from mice undergoing therapy with GM-CSF plus antibody significantly reduced the dissemination of melanoma in secondary recipients but only after irradiation, not in intact mice. GM-CSF also induced significant ADCC in human BM macrophages against a melanoma and a lymphoma in vitro and against a lymphoma implanted in nude mice in vivo. Again, these effects were more optimal after chemotherapy. These data suggest that treatment with GM-CSF plus tumor-specific monoclonal antibodies after BMT may induce an antitumor effect and help eradicate the minimal residual disease.
In vitro stimulatory effect of substance P on hematopoiesis
Authors: Rameshwar P , Ganea D , Gascon P 
Published: October 2019

Abstract
The neuropeptide Substance P (SP) is widely distributed in the peripheral nervous system. Its biologic effects have been extensively studied in the immune system. However, even though the bone marrow (BM) is innervated with SP-immunoreactive fibers and some of its cells not only express SP receptors (T and B cells, endothelial cells, and macrophages) but also produce SP (macrophages, eosinophils, and endothelial cells), the effects of SP on hematopoiesis are scanty. Furthermore, SP induces the production of hematopoietic growth factors (HGFs) (interleukin-1 [IL-1], IL-6, and tumor necrosis factor alpha) from human monocytes. In this study, we have found a potent in vitro stimulatory effect of SP (10(-8) to 10(-12) mol/L) on hematopoiesis for both erythroid and granulocytic progenitors in short-term methyl- cellulose BM cultures. SP alone, in the absence of exogenous HGFs, is able to sustain hematopoiesis in vitro. This stimulatory effect of SP is: (1) mostly mediated by the adherent cells; (2) completely abrogated by two SP receptor (SP-R) antagonists; and (3) partially reduced by anti-IL-1, IL-3, IL-6, and granulocyte-macrophage colony-stimulating factor (GM-CSF). Furthermore, it appears that the stimulatory effect of SP may be mediated by IL-3 and GM-CSF because we have also found that SP induces the release of these two cytokines from BM mononuclear cells. Considering that the SP effect occurs at concentrations as low as 10(-11) mol/L, and via a specific receptor, it appears that SP may play a physiologic role in regulating hematopoiesis, at least partially through the adherent BM cells and the release of HGFs, and may place SP, a neuropeptide, in a new category of hematopoietic regulators.
CD34 expression is regulated reciprocally with adhesion molecules in vascular endothelial cells in vitro
Authors: Delia D , Lampugnani MG , Resnati M , Dejana E , Aiello A , Fontanella E , Soligo D , Pierotti MA , Greaves MF 
Published: October 2019

Abstract
Freshly cultured vascular endothelial cells express the CD34 antigen in a diffuse cell surface pattern with some concentration on microvilli. Expression is downregulated with proliferation in continuous culture and undetectable after nine population doublings but can be maintained by restraining cell proliferation and promoting cell contact. Expression of CD34 at the antigen and mRNA levels on early passage cells is rapidly downregulated by interleukin-1 beta (IL-1 beta), interferon-gamma (INF-gamma), and tumor necrosis factor-alpha (TNF- alpha) under conditions in which these ligands upregulate the adhesion molecules: endothelial leukocyte adhesion molecule 1 (ELAM-1) and intracellular adhesion molecule 1 (ICAM-1). This reciprocal pattern of expression and the topographic distribution of CD34 molecules on the lumenal interdigitated microprocesses of adjacent endothelial cells in vivo suggest that CD34 might have a negative modulating role on adhesion functions of endothelia.
Adhesion of human myeloma-derived cell lines to bone marrow stromal cells stimulates interleukin-6 secretion
Authors: Uchiyama H , Barut BA , Mohrbacher AF , Chauhan D , Anderson KC 
Published: October 2019

Abstract
Previous studies show that human myeloma-derived cell lines specifically adhere to fibronectin (FN) through very late antigen-4 (VLA-4; alpha 4 beta 1 integrin complex) and RGD-peptide mechanisms, which may contribute to the localization of tumor cells in bone marrow (BM). In these studies, we characterized the adhesion of myeloma- derived cell lines to both normal and myeloma BM stromal cells (BMSCs) and the effect of adhesion on DNA synthesis. Because interleukin-6 (IL- 6) plays an important role in the pathogenesis of multiple myeloma, we also examined the effects of tumor cell adhesion on IL-6 secretion by BMSCs. In 51chromium binding assays, the U266, ARH-77, and IM-9 cell lines showed 52% +/- 12%, 55% +/- 6%, and 47% +/- 7% specific adherence, respectively, to normal BMSCs and 74% +/- 4%, 60% +/- 3%, and 61% +/- 6% specific adherence, respectively, to myeloma BMSCs. In contrast, only 12% to 13% specific binding of HS-Sultan cells to BMSCs was noted. The binding of myeloma cells to BMSCs was partially blocked with anti-beta 1 monoclonal antibody (MoAb), anti-beta 2 integrin MoAb, and excess RGD peptide, suggesting multiple mechanisms for the adhesion of myeloma cell lines to BMSCs. Binding of cell lines to FN or myeloma BMSCs did not affect cell line proliferation; however, adhesion of myeloma cell lines to normal BMSCs decreased DNA synthesis, ie, stimulation indices are 0.1 +/- 0.04, 0.2 +/- 0.1, 0.2 +/- 0.07, and 0.1 +/- 0.06 for the adherent non-IL-6-dependent U266, ARH-77, HS- Sultan, and IM-9 cells, respectively (n = 5, P < .01). In contrast, adherence of IL-6-dependent B9 cells increased their proliferation (stimulation index, 3.2 +/- 0.7). Significant (twofold to eightfold) increases in IL-6 secretion were evident in cell line-adherent (> or = 12 hours) normal and myeloma BMSC cultures. Paraformaldehyde fixation of BMSCs before adhesion completely abrogated IL-6 secretion, suggesting that IL-6 secretion was triggered in BMSCs rather than in cell lines. Partial blocking of cell line adhesion to BMSCs, using anti- beta 1 integrin and anti-beta 2 integrin MoAbs and RGD peptide, also partially blocked the triggering of IL-6 secretion by BMSCs. When cell lines were placed in Transwell inserts and then cultured with either normal or myeloma BMSCs, permitting juxtaposition without cell to cell contact between myeloma cell lines and BMSCs, no increase in IL-6 secretion was observed.(ABSTRACT TRUNCATED AT 400 WORDS)