bluuebunny/crossref_metadata_2025_split huggingface dataset:
P-Selectin and Platelet Clearance
Authors: Berger Gaëtan , Hartwell Daqing W. , Wagner Denisa D. 
Published: October 2019

AbstractP-selectin is an adhesion receptor for leukocytes expressed by activated platelets and endothelial cells. To assess a possible role of P-selectin in platelet clearance, we adapted an in vivo biotinylation technique in mice. Wild-type and P-selectin–deficient mice were infused with N-hydroxysuccinimido biotin. The survival of biotinylated platelets was followed by flow cytometry after labeling with fluorescent streptavidin. Both wild-type and P-selectin–deficient platelets presented identical life spans of about 4.7 days, suggesting that P-selectin does not play a role in platelet turnover. When biotinylated platelets were isolated, activated with thrombin, and reinjected into mice, the rate of platelet clearance was unchanged. In contrast, storage of platelets at 4°C caused a significant reduction in their life span in vivo but again no significant differences were observed between the two genotypes. The infused thrombin-activated platelets rapidly lost their surface P-selectin in circulation, and this loss was accompanied by the simultaneous appearance of a 100-kD P-selectin fragment in the plasma. This observation suggests that the platelet membrane P-selectin was shed by cleavage. In conclusion, this study shows that P-selectin, despite its binding to leukocytes, does not mediate platelet clearance. However, the generation of a soluble form of P-selectin on platelet activation may have biological implications in modulating leukocyte recruitment or thrombus growth.
Norethisterone Treatment, a Major Risk-Factor for Veno-Occlusive Disease in the Liver After Allogeneic Bone Marrow Transplantation
Authors: Hägglund Hans , Remberger Mats , Klaesson Sven , Lönnqvist Berit , Ljungman Per , Ringdén Olle 
Published: October 2019

AbstractIn this single-center study, we retrospectively analyzed incidence and risk factors for hepatic veno-occlusive disease (VOD) in 249 consecutive patients who underwent allogeneic hematopoietic stem cell transplantation between January 1990 and June 1995. Twenty-four of the 249 transplanted patients developed VOD. The probabilities of developing VOD were 17% among women and 7% in men (P = .01). In women treated with norethisterone, the incidence was 27% compared with 3% in women without this treatment (P = .007). One-year survival rates were 17% and 73% in patients with (n = 24) or without VOD (n = 225), respectively. The use of heparin prophylaxis (100 IE/kg/24 hours for 1 month) did not alter the incidence or 1-year mortality of VOD. In multivariate analysis, the following risk factors were significant: norethisterone treatment (P &lt; .001), bilirubin &gt;26 μmol/L before bone marrow transplantation (BMT) (P = .002), one HLA-antigen mismatch (P = .003), previous abdominal irradiation (P = .02), and conditioning with busulphan (P = .02). Our conclusion is that norethisterone treatment should not be used in patients undergoing BMT and heparin prophylaxis did not affect the incidence or mortality of VOD.
Hematopoietic Cells From -Spectrin–Deficient Mice Are Sufficient to Induce Thrombotic Events in Hematopoietically Ablated Recipients
Authors: Wandersee Nancy J. , Lee John C. , Kaysser Tamma M. , Bronson Roderick T. , Barker Jane E. 
Published: October 2019

AbstractThrombotic events are life-threatening complications of human hemolytic anemias such as paroxysmal nocturnal hemoglobinuria, sickle cell disease, and thalassemia. It is not clear whether these events are solely influenced by aberrant hematopoietic cells or also involve aberrant nonhematopoietic cells. Spherocytosis mutant (Spna1sph/Spna1sph; for simplicity referred to as sph/sph) mice develop a severe hemolytic anemia postnatally due to deficiencies in -spectrin in erythroid and other as yet incompletely defined nonerythroid tissues. Thrombotic lesions occur in all adult sph/sph mice, thus providing a hematopoietically stressed model in which to assess putative causes of thrombus formation. To determine whether hematopoietic cells fromsph/sph mice are sufficient to initiate thrombi, bone marrow from sph/sph or +/+ mice was transplanted into mice with no hemolytic anemia. One set of recipients was lethally irradiated; the other set was genetically stem cell deficient. All mice implanted withsph/sph marrow, but not +/+ marrow, developed severe anemia and histopathology typical of sph/sph mice. Histological analyses of marrow recipients showed that thrombi were present in the recipients of sph/sph marrow, but not +/+ marrow. The results indicate that the -spectrin–deficient hematopoietic cells of sph/sph mice are the primary causative agents of the thrombotic events.
Specific Signals Generated by the Cytoplasmic Domain of the Granulocyte Colony-Stimulating Factor (G-CSF) Receptor Are Not Required for G-CSF–Dependent Granulocytic Differentiation
Authors: Jacob Jason , Haug Jeffery S. , Raptis Sofia , Link Daniel C. 
Published: October 2019

AbstractGranulocyte colony-stimulating factor (G-CSF) is the principal growth factor regulating the production of neutrophils, yet its role in lineage commitment and terminal differentiation of hematopoietic progenitor cells is controversial. In this study, we describe a system to study the role of G-CSF receptor (G-CSFR) signals in granulocytic differentiation using retroviral transduction of G-CSFR–deficient, primary hematopoietic progenitor cells. We show that ectopic expression of wild-type G-CSFR in hematopoietic progenitor cells supports G-CSF–dependent differentiation of these cells into mature granulocytes, macrophages, megakaryocytes, and erythroid cells. Furthermore, we show that two mutant G-CSFR proteins, a truncation mutant that deletes the carboxy-terminal 96 amino acids and a chimeric receptor containing the extracellular and transmembrane domains of the G-CSFR fused to the cytoplasmic domain of the erythropoietin receptor, are able to support the production of morphologically mature, chloroacetate esterase-positive, Gr-1/Mac-1–positive neutrophils in response to G-CSF. These results demonstrate that ectopic expression of the G-CSFR in hematopoietic progenitor cells allows for multilineage differentiation and suggest that unique signals generated by the cytoplasmic domain of the G-CSFR are not required for G-CSF–dependent granulocytic differentiation.
B-Cell Chronic Lymphocytic Leukemia Cells Express a Functional Inducible Nitric Oxide Synthase Displaying Anti-Apoptotic Activity
Authors: Zhao Haixia , Dugas Nathalie , Mathiot Claire , Delmer Alain , Dugas Bernard , Sigaux François , Kolb Jean-Pierre 
Published: October 2019

AbstractThe expression of different isoforms of nitric oxide synthase (NOS) was investigated in B-cell chronic lymphocytic leukemia (B-CLL) to delineate a possible role for nitric oxide (NO) in the control of apoptosis of the tumoral cells. By reverse transcription-polymerase chain reaction (RT-PCR), all B-CLL cells were found to express spontaneously inducible NOS (iNOS) mRNA, whereas endothelial constitutive NOS (ecNOS) mRNA was undetectable. The iNOS protein was detected by immunofluorescence in the cytoplasm of permeabilized leukemic cells and identified by Western blotting, using different anti-iNOS antibodies, as a protein of 135 kD in B-CLL cytoplasmic extracts. B-CLL cell lysates also displayed basal NOS enzymatic activity, as measured by the conversion of14C-labeled L-arginine into 14C-L-citrulline. Ligation of CD23, expressed on the vast majority of B-CLL cells, resulted in increased iNOS expression and activity. The NO released exerted an anti-apoptotic effect on B-CLL cells that was counteracted by NOS inhibitors and engagement of the APO-1/Fas pathway. Therefore, the existence of a functional iNOS in B-CLL cells will provide further insights into the mechanisms that control proliferation and apoptosis in these tumor cells.© 1998 by The American Society of Hematology.
The α-Chemokine Receptor CXCR4 Is Expressed on the Megakaryocytic Lineage From Progenitor to Platelets and Modulates Migration and Adhesion
Authors: Wang Jian-Feng , Liu Zhong-Ying , Groopman Jerome E. 
Published: October 2019

AbstractCXCR4 is the receptor for the α-chemokine stromal cell-derived factor 1 (SDF-1) and has been shown to be expressed on a diversity of leukocytes. In this report, the expression of the CXCR4 receptor in cells of megakaryocytic lineage and the role of SDF-1 in megakaryocytopoiesis were investigated. Using flow cytometry in combination with reverse transcriptase-polymerase chain reaction (RT-PCR), we observed that bone marrow CD34+, CD61+ cells, blood platelets, and megakaryocytic leukemia cell lines all expressed the CXCR4 receptor. To examine the expression of the CXCR4 receptor on megakaryocyte progenitors (colony-forming units-megakaryocyte [CFU-Meg]), CXCR4-positive and -negative CD34+ populations were separated from bone marrow and cultured in a plasma clot culture system. A subpopulation of the CFU-Meg was found in the CXCR4-positive fraction. The functional significance of CXCR4 expression on cells of the megakaryocytic lineage was examined by studying the effects of SDF-1α on migration and proliferation of megakaryocyte progenitor cells in vitro. We found that SDF-1α potently induced megakaryocyte progenitor migration and significantly enhanced adhesion of mature marrow megakaryocytes to endothelium. No marked effects of SDF-1α alone or in combination with thrombopoietin and stem cell factor/kit ligand on megakaryocyte production in vitro were noted. These results demonstrate for the first time that the CXCR4 α-chemokine receptor is expressed on cells of the megakaryocytic lineage from progenitors to platelets and that its ligand SDF-1α may modulate several aspects of megakaryocytopoiesis.© 1998 by The American Society of Hematology.
Intermittent, Repetitive Corticosteroid-Induced Upregulation of Platelet Levels After Adenovirus-Mediated Transfer to the Liver of a Chimeric Glucocorticoid-Responsive Promoter Controlling the Thrombopoietin cDNA
Authors: Narumi Ko , Suzuki Motoyoshi , Song Wenru , Moore Malcolm A.S. , Crystal Ronald G. 
Published: October 2019

AbstractFor many in vivo gene therapy clinical applications, it is desirable to control the expression of the transferred transgene using pharmacologic agents. To evaluate the feasibility of accomplishing this using corticosteroids, pharmacologic agents widely used in clinical medicine, we constructed replication deficient adenoviral (Ad) vectors containing an expression cassette with a chimeric promoter comprised of five glucocorticoid response elements (GRE) and the chloramphenicol acetyltransferase reporter gene (AdGRE.CAT) or the murine thrombopoietin cDNA (AdGRE.mTPO). In vitro studies showed the vectors functioned as expected, with marked glucocorticoid-induced upregulation of the CAT or mTPO transgenes. To evaluate the inducibility of the GRE promoter in vivo, the AdGRE.CAT vector was administered intravenously to C57B1/6 mice, and CAT activity was quantified in liver before and after intraperitoneal administration of dexamethasone. The GRE promoter activity was dependent on the dexamethasone dose, with a 100-fold increase in CAT expression with 50 μg dexamethasone, similar to the levels observed in vivo with the Rous sarcoma virus long terminal repeat constitutive promoter. After dexamethasone administration, maximum CAT activity was observed at day 2, with a slow decline to baseline levels by 2 weeks. Based on these observations, we hypothesized that a single administration of an Ad vector-mediated transfer of the chimeric GRE inducible promoter driving the mTPO cDNA would enable repetitive administration of corticosteroids to repetitively upregulate platelet levels for 1 to 2 weeks. The data show that this occurs, with dexamethasone administration every 3 weeks associated with 1-week elevations (at each 3-week interval) of serum mTPO levels, megakaryocyte numbers in bone marrow, and platelet levels fourfold to sixfold over baseline. Thus, with the appropriate promoter, it is possible to use a commonly used pharmacologic agent to upregulate the expression of a newly transferred gene on demand.© 1998 by The American Society of Hematology.
Mutual Education Between Hematopoietic Cells and Bone Marrow Stromal Cells Through Direct Cell-to-Cell Contact: Factors That Determine the Growth of Bone Marrow Stroma-Dependent Leukemic (HB-1) Cells
Authors: Jiang Huijie , Sugimoto Kenkichi , Sawada Hitoshi , Takashita Emi , Tohma Maki , Gonda Hiroyuki , Mori Kazuhiro John 
Published: October 2019

AbstractA stroma-dependent cell line (HB-1) was established from myelogenous leukemic cells of CBA/N mouse. Characterization of the cells showed that HB-1 proliferated on hematopoietic supportive stromal cells (MS-10), but did not survive or proliferate on hematopoietic nonsupportive cells (MS-K). Direct contact between HB-1 and MS-10 appears to be necessary for HB-1 to proliferate on MS-10. We found that interleukin-1α (IL-1α) produced by MS-10 plays a major role in the survival and proliferation of HB-1. IL-11 did not support the proliferation of HB-1 cells by itself, but enhanced the proliferation of HB-1 cells in the presence of IL-1α. The expression of IL-1α and IL-11 was induced in MS-10 by the direct contact with HB-1 cells, and the expression of IL-1 receptor type I (IL-1RI) and interleukin-11 receptor (IL-11R) was induced in HB-1 cells by the attachment of the cells to MS-10. These findings show the existence of two-way interactions between HB-1 and MS-10.© 1998 by The American Society of Hematology.
Stomach Implant for Long-Term Erythropoietin Expression in Rats
Authors: Lejnieks Daniel V. , Ramesh N. , Lau Stella , Osborne William R.A. 
Published: October 2019

AbstractTo approach the goal of consistent long-term erythropoietin (Epo) expression in vivo, we developed an implantation procedure in which transduced autologous vascular smooth muscle was introduced into rats in a chamber created from a polytetrafluoroethylene (PTFE) ring placed under the serosa of the stomach. The implant became vascularized and permitted the long-term survival of smooth muscle cells expressing Epo. Hematocrits of treated animals increased rapidly and monitored over 12 months gave a mean value of 56.0 ± 4.0% (P &lt; .001; n = 9), increased from a presurgery mean of 42.3 ± 1.6%. Hemoglobin levels rose from a presurgery mean of 15.2 ± 0.4 g/dL and for 12 months were significantly elevated with a mean value of 19.5 ± 1.3 g/dL (P &lt; .001; n = 9). The hematocrit and hemoglobin levels of control animals receiving human adenosine deaminase (ADA)–expressing cells were not significantly different from baseline (P &gt; .05; n = 5). In response to tissue oxygenation, kidney, and (to a lesser extent) liver are specific organs that synthesize Epo. Treated animals showed downregulation of endogenous Epo mRNA in kidney over a 12-month period. The PTFE implant provides sustained gene delivery, is safe, and is minimally invasive. It allows easy engraftment of transduced cells and may be applied generally to the systemic delivery of therapeutic proteins such as hormones and clotting factors.© 1998 by The American Society of Hematology.
Erythropoietin Receptor and STAT5-Specific Pathways Promote SKT6 Cell Hemoglobinization
Authors: Gregory Richard C. , Jiang Ning , Todokoro Kazuo , Crouse Jill , Pacifici Robert E. , Wojchowski Don M. 
Published: October 2019

AbstractErythrocyte production in mammals is known to depend on the exposure of committed progenitor cells to the glycoprotein hormone erythropoietin (Epo). In chimeric mice, gene disruption experiments have demonstrated a critical role for Epo signaling in development beyond the erythroid colony-forming unit (CFU-e) stage. However, whether this might include the possible Epo-specific induction of red blood cell differentiation events is largely unresolved. To address this issue, mechanisms of induced globin expression in Epo-responsive SKT6 cells have been investigated. Chimeric receptors containing an epidermal growth factor (EGF) receptor extracellular domain and varied Epo receptor cytoplasmic domains first were expressed stably at physiological levels in SKT6 cells, and their activities in mediating induced hemoglobinization were assayed. While activity was exerted by a full-length chimera (EE483), truncation to remove 7 of 8 carboxyl-terminal tyrosine sites (EE372) markedly enhanced differentiation signaling. Moreover, mutation of a STAT5 binding site in this construct (EE372-Y343F) inhibited induced globin expression and SKT6 cell hemoglobinization, as did the ectopic expression of dominant-negative forms of STAT5 in parental SKT6 cells. As in normal CFU-e, SKT6 cells also were shown to express functional receptors for stem cell factor (SCF). To further define possible specific requirements for differentiation signaling, effects of SCF on SKT6 cell hemoglobinization were tested. Interestingly, SCF not only failed to promote globin expression but inhibited this Epo-induced event in a dose-dependent, STAT5-independent fashion. Thus, effects of Epo on globin expression may depend specifically on STAT5-dependent events, and SCF normally may function to attenuate terminal differentiation while promoting CFU-e expansion.© 1998 by The American Society of Hematology.
Ex Vivo Expansion of Genetically Marked Rhesus Peripheral Blood Progenitor Cells Results in Diminished Long-Term Repopulating Ability
Authors: Tisdale J.F. , Hanazono Y. , Sellers S.E. , Agricola B.A. , Metzger M.E. , Donahue R.E. , Dunbar C.E. 
Published: October 2019

AbstractThe possibility of primitive hematopoietic cell ex vivo expansion is of interest for both gene therapy and transplantation applications. The engraftment of autologous rhesus peripheral blood (PB) progenitors expanded 10 to 14 days were tracked in vivo using genetic marking. Stem cell factor (SCF)/granulocyte colony-stimulating factor (G-CSF)–mobilized and CD34-enriched PB cells were divided into two equal aliquots and transduced with one of two retroviral vectors carrying the neomycin-resistance gene (neo) for 4 days in the presence of interleukin-3 (IL-3), IL-6, and SCF in the first 5 animals, IL-3/IL-6/SCF/Flt-3 ligand (FLT) in 2 subsequent animals, or IL-3/IL-6/SCF/FLT plus an autologous stromal monolayer (STR) in the final 2. At the end of transduction period, one aliquot (nonexpanded) from each animal was frozen, whereas the other was expanded under the same conditions but without vector for a total of 14 days before freezing. After total body irradiation, both the nonexpanded and expanded transduced cells were reinfused. Despite 5- to 13-fold higher cell and colony-forming unit (CFU) doses from the expanded fraction of marked cells, there was greater short- and long-term marking from the nonexpanded cells in all animals. In animals receiving cells transduced and expanded in the presence of IL-3/IL-6/SCF/FLT, engraftment by the marked expanded cells was further diminished. This discrepancy was even more pronounced in the animals who received cells transduced and expanded in the presence of FLT and autologous stroma, with no marking detectable from the expanded cells. Despite lack of evidence for expansion of engrafting cells, we found that the addition of FLT and especially STR during the initial brief transduction period increased engraftment with marked cells into a clinically relevant range. Levels of marked progeny cells originating from the nonexpanded aliqouts were significantly higher than that seen in previous 4 animals receiving cells transduced in the presence of IL-3/IL-6/SCF, with levels of 10% to 20% confirmed by Southern blotting from the nonexpanded IL-3/IL-6/SCF/FLT/STR graft compared with 0.01% in the original IL-3/IL-6/SCF cohort. These results suggest that, although expansion of PB progenitors is feasible ex vivo, their contribution towards both short- and long-term engraftment is markedly impaired. However, a brief transduction in the presence of specific cytokines and stromal support allows engraftment with an encouraging number of retrovirally modified cells.This is a US government work. There are no restrictions on its use.
Transformation of Mycosis Fungoides/Sezary Syndrome: Clinical Characteristics and Prognosis
Authors: Diamandidou Eleni , Colome-Grimmer Maria , Fayad Luis , Duvic Madeleine , Kurzrock Razelle 
Published: October 2019

Abstract
The occurrence of large cell transformation has been well documented in a subgroup of patients with mycosis fungoides/Sezary syndrome (MF/SS). However, because of the rarity of MF/SS, little is known about the influence of clinicopathologic features in predicting large cell transformation and about outcome in the transformed cases. We evaluated all patients with MF/SS who were registered in our clinic during the study period and for whom pathologic slides for review were available or could be obtained. Disease was classified as transformed if biopsy showed large cells (≥4 times the size of a small lymphocyte) in more than 25% of the infiltrate or if they formed microscopic nodules. Twenty-six patients with transformation were identified from a total of 115 evaluable cases with a diagnosis of MF/SS. The actuarial cumulative probability of transformation reached 39% in 12 years. The median time from diagnosis of MF/SS to transformation was 12 months (range, 0 to 128 months). Thirty-one percent of all patients with stage IIB-IV disease at presentation eventually transformed versus 14% of those with stage I-IIA (P= .03), with transformation being especially common in patients with tumors (T3), 46% of whom transformed. Combining elevated β2 microglobulin and lactic dehydrogenase (neither elevated v one or both elevated) was also predictive for transformation (P = .009). The median survival from initial diagnosis of MF/SS for the transformed patients was 37 months versus 163 months for the untransformed group (P = .0029). The median survival from transformation was 19.4 months (range, 2+ to 138 months). The following characteristics were associated with an inferior survival in transformed patients: (1) early transformation (&lt;2 years from the diagnosis v ≥2 years; P = .011) and (2) advanced stage (IIB-IV v I-IIA; 2-year survival, 23% v 86%;P = .0035). We conclude that MF/SS patients with stages IIB-IV disease and, in particular, those with tumors have a high incidence of large-cell transformation. Patients with transformation have a relatively poor survival, especially if transformation occurs early (within 2 years) in the course of disease or if they are staged as IIB or higher.
© 1998 by The American Society of Hematology.