bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Multicenter Prospective Study on the Risk of Acquiring Liver Disease in Anti–Hepatitis C Virus Negative Patients Affected From Homozygous β-Thalassemia
Authors: Prati Daniele , Zanella Alberto , Farma Elena , De Mattei Claudia , Bosoni Patrizia , Zappa Manuela , Picone Alessandra , Mozzi Fulvio , Rebulla Paolo , Cappellini Maria Domenica , Allain Jean-Pierre , Sirchia Girolamo 
Published: October 2019

Abstract
Although the risk of transfusion-transmitted hepatitis has been recently reduced, transfusion-dependent β-thalassemia patients may still develop liver disease due to viral infection or iron overload. We assessed the frequency and causes of liver dysfunction in a cohort of anti–hepatitis C virus (HCV) negative thalassemics. Of 1,481 thalassemics enrolled in 31 centers, 219 (14.8%) tested anti-HCV− by second-generation assays; 181 completed a 3-year follow-up program consisting of alanine-aminotransferase (ALT) measurement at each transfusion and anti-HCV determination by third-generation enzyme-immunoassay (EIA-3) at the end of study. Serum ferritin levels were determined at baseline and at the end of follow-up. Ten patients were anti-HCV+ by EIA-3 at the end of follow-up. Of them, seven were already positive in 1992 to 1993 when the initial sera were retested by EIA-3, one tested indeterminate by confirmatory assay, and two had true seroconversion (incidence, 4.27/1,000 person years; risk of infection, 1/7,100 blood units, 95% confidence interval [CI], 1 in 2,000-1 in 71,000 units). At baseline, 67 of 174 thalassemics had abnormal ALT. Of those with normal ALT, seven subsequently developed at least one episode of moderate ALT increase (incidence, 24.6/1,000 person-years). All of the 20 patients with ferritin values ≥3,000 ng/mL had clinically relevant ALT abnormalities, as compared with 53 of 151 with &lt;3,000 ng/mL (P&lt; .005). Hepatic dysfunction is still frequent in thalassemics. Although it is mainly attributable to siderosis and primary HCV infection, the role of undiscovered transmissible agents cannot be excluded.
© 1998 by The American Society of Hematology.
Osteoclast-Mediated Bone Resorption Is Stimulated During Short-Term Administration of Granulocyte Colony-Stimulating Factor But Is Not Responsible for Hematopoietic Progenitor Cell Mobilization
Authors: Takamatsu Yasushi , Simmons Paul J. , Moore Robert J. , Morris Howard A. , To Luen B. , Lévesque Jean-Pierre 
Published: October 2019

AbstractThe cellular and molecular mechanisms responsible for hematopoietic progenitor cell (HPC) mobilization from bone marrow (BM) into peripheral blood after administration of cytokines such as granulocyte colony-stimulating factor (G-CSF) are still unknown. In this study we show that high concentrations of soluble calcium induce the detachment of BM CD34+ HPC adherent on fibronectin, a major component of BM extracellular matrix. Because G-CSF has been shown to induce osteoporosis in patients with congenital neutropenia and in G-CSF–overexpressing transgenic mice, we hypothesized that short-term G-CSF administration may be sufficient to induce bone resorption, resulting in the release of soluble calcium in the endosteum leading in turn to the inhibition of attachment to fibronectin and the egress of HPC from the BM. We show herein that in humans, serum osteocalcin concentration, a specific marker of bone formation, is strongly reduced after 3 days of G-CSF administration. Furthermore, in patients mobilized with G-CSF either alone or in association with stem cell factor or interleukin-3, the reduction of serum osteocalcin is significantly correlated with the number of HPC mobilized in peripheral blood. Urine levels of deoxypyridinoline (DPyr), a specific marker of bone resorption, gradually elevated during the time course of G-CSF administration until day 7 after cessation of G-CSF, showing a simultaneous stimulation of bone degradation during G-CSF–induced HPC mobilization. In an in vivo murine model, we found that the number of osteoclasts was dramatically increased paralleling the elevation of DPyr after G-CSF administration. When pamidronate, an inhibitor of osteoclast-mediated bone resorption, was administered together with G-CSF in mice, the G-CSF–induced increase of DPyr levels was completely abolished whereas the numbers of colony-forming cells mobilized in peripheral blood were not decreased, but unexpectedly increased relative to the numbers elicited by G-CSF alone. Collectively, our data therefore show that short-term administration of G-CSF induces bone degradation by a simultaneous inhibition of bone formation and an enhanced osteoclast-mediated bone resorption. This increased bone resorption is inhibited by pamidronate without reducing G-CSF–induced HPC mobilization, suggesting that the activation of bone resorption after G-CSF administration is not the direct cause of HPC mobilization as initially hypothesized, but a parallel event.© 1998 by The American Society of Hematology.
Heparan Sulfate Proteoglycans Mediate Interleukin-7– Dependent B Lymphopoiesis
Authors: Borghesi Lisa A. , Yamashita Yoshio , Kincade Paul W. 
Published: October 2019

AbstractHeparin/heparan sulfate proteoglycans (HSPGs) have the potential to bind and directly regulate the bioactivity of hematopoietic growth factors including interleukin-7 (IL-7), a cytokine critical for murine B-cell development. We examined the consequence of manipulating soluble heparin and cell-surface heparan sulfate to IL-7–dependent responses of B-cell precursors. Soluble heparin was found to inhibit production of lymphoid, but not myeloid, cells in long-term bone marrow cultures. Analysis of pro-B cells lacking plasma membrane HS suggests that this glycosaminoglycan is required for efficient binding and responsiveness to IL-7. By contrast, responses of hematopoietic cells to other cytokines were not influenced by heparin addition or HS removal. Therefore, HSPGs on B-lineage precursors may function as IL-7 receptor components similar to HSPGs known to be important for the bFGF receptor. Other experiments suggest that HSPGs on the surface of stromal cells provide a weakly associating docking site for IL-7, possibly controlling availability of this cytokine to B-cell precursors. Together these data demonstrate a direct role for heparinlike molecules in regulating the IL-7–dependent stages of murine B lymphopoiesis.
Marginal-Zone B Cells in the Human Lymph Node and Spleen Show Somatic Hypermutations and Display Clonal Expansion
Authors: Tierens Anne , Delabie Jan , Michiels Lieve , Vandenberghe Peter , De Wolf-Peeters Chris 
Published: October 2019

AbstractSplenic marginal-zone B cells, marginal-zone B cells of Peyer’s patches in the gut, and nodal marginal-zone B cells (also identified as monocytoid B cells) share a similar morphology and immunophenotype. These cells likely represent a distinct subset of B cells in humans and rodents, but their precise ontogenetic relationship as well as their origin from B cells of the germinal center is still debated. To study this, we performed a mutation analysis of the rearranged immunoglobulin variable genes (VH) of microdissected single nodal and splenic marginal-zone cells. In addition, we investigated the presence of proliferating cells and B-cell clones in the human splenic and nodal marginal zone as well as adjacent germinal centers. This was performed by immunohistochemical staining for the Ki-67 antigen and denaturing gradient gel analysis of amplified immunoglobulin heavy chain genes’ complementarity determining region 3 of microdissected cell clusters. A variable subset of nodal and splenic marginal-zone B cells showed somatic mutations in their rearranged VH genes, indicating that both virgin and memory B cells are present in the nodal and splenic marginal zone. Nodal and splenic marginal-zone B cells preferentially rearranged VH3 family genes such as DP47, DP49, DP54, and DP58. A preferential rearrangement of the same VH genes has been shown by others in the peripheral CD5− IgM+ B cells. These data suggest that the splenic and nodal marginal-zone B cells are closely related B-cell subsets. We also showed that marginal-zone B cells may cycle and that clones of B cells are frequently detected in the nodal as well as the splenic marginal zone. These clones are not related to those present in adjacent germinal centers. These data favor the hypothesis that clonal expansion occurs in the marginal zone. Whether the somatic hypermutation mechanism is activated during the clonal expansion in the marginal zone and which type of immune response triggers the clonal expansion need to be elucidated.
Arsenic Trioxide and Interferon- Synergize to Induce Cell Cycle Arrest and Apoptosis in Human T-Cell Lymphotropic Virus Type I–Transformed Cells
Authors: Bazarbachi Ali , El-Sabban Marwan E. , Nasr Rihab , Quignon Frédérique , Awaraji Christian , Kersual Joelle , Dianoux Laurent , Zermati Yael , Haidar Joud H. , Hermine Olivier , de Thé Hughes 
Published: October 2019

AbstractHuman T-cell lymphotropic virus type I (HTLV-I) is the causative agent of adult T-cell leukemia/lymphoma (ATL). ATL is an aggressive proliferation of mature activated T cells associated with a poor prognosis. The combination of the antiviral agents, zidovudine (AZT) and  interferon (IFN), is a potent treatment of ATL. Recently, arsenic trioxide (As) was shown to be an effective treatment of acute promyelocytic leukemia (APL). We have tested the effects of the combination of As and IFN on cell proliferation, cell cycle phases distribution, and apoptosis in ATL-derived or control T-cell lines. A high synergistic effect between IFN and As was observed in ATL-derived cell lines in comparison to the control cell lines, with a dramatic inhibition of cell proliferation, G1 arrest, and induction of apoptosis. Similar results were obtained with fresh leukemia cells derived from an ATL patient. Although the mechanisms involved are unclear, these results could provide a rational basis for combined As and IFN treatments in ATL.
The Use of Allele-Specific Recombinant Fcγ Receptor IIIb Antigens for the Detection of Granulocyte Antibodies
Authors: Bux Juergen , Kissel Karin , Hofmann Christine , Santoso Sentot 
Published: October 2019

AbstractThe Fcγ receptor IIIb (FcγRIIIb) for the Fc domain of IgG is expressed exclusively on neutrophils. The FcγRIIIb bears allotypic polymorphisms referred to as NA1, NA2, and SH, which are known for their frequent involvement in alloimmune and autoimmune neutropenias as well as in transfusion reactions. The bactericidal capacity of isolated neutrophils is easily activatable, and activation results in self-desintegration, thus preventing storage of neutrophils. As a result, only freshly isolated granulocytes can be used for antibody screening, often making it impossible to use typed panel cells. To provide a readily available source of typed panel cells, we therefore established stable mammalian cells expressing recombinant NA1, NA2, and SH antigens. We isolated mRNA from typed neutrophils and then transcribed it in cDNA. The cDNA that codes for the different forms of the FcγRIIIb was amplified by polymerase chain reaction and was subsequently subcloned into the mammalian expression vector pcDNA3. Chinese hamster ovary (CHO) cells were transfected with allele-specific constructs, and stable cell lines expressing FcγRIIIb were selected by flow cytometry. Because human sera show high background fluorescence with transfectants in flow cytometry, the monoclonal antibody–specific isolation of granulocyte antigens (MAIGA) assay was performed. By MAIGA assay, we tested 14 well-characterized human alloantibodies directed against the antigens NA1, NA2, and SH; 5 FcγRIIIb-specific isoantibodies; and 12 FcγRIIIb-reactive autoantibodies. Except one NA1- and one SH-specific alloantibody, all other antibodies could be identified by the use of CHO transfectants. In contrast to neutrophils, fixed CHO cells can be stored at 4°C for at least 4 weeks or stored frozen for a longer period. This longer shelf life of the transfected CHO cells compared with isolated neutrophils will simplify the detection of the clinically most important FcγRIIIb-reactive alloantibodies and autoantibodies.
Evaluation of Biochemical Changes During In Vivo Erythrocyte Senescence in the Dog
Authors: Rettig Michael P. , Low Philip S. , Gimm J. Aura , Mohandas Narla , Wang Jiazhen , Christian John A. 
Published: October 2019

AbstractOne hypothesis to explain the age-dependent clearance of red blood cells (RBCs) from circulation proposes that denatured/oxidized hemoglobin (hemichromes) arising late during an RBC’s life span induces clustering of the integral membrane protein, band 3. In turn, band 3 clustering generates an epitope on the senescent cell surface leading to autologous IgG binding and consequent phagocytosis. Because dog RBCs have survival characteristics that closely resemble those of human RBCs (ie, low random RBC loss, ≈115-day life span), we decided to test several aspects of the above hypothesis in the canine model, where in vivo aged cells of defined age could be evaluated for biochemical changes. For this purpose, dog RBCs were biotinylated in vivo and retrieved for biochemical analysis at various later dates using avidin-coated magnetic beads. Consistent with the above hypothesis, senescent dog RBCs were found to contain measurably elevated membrane-bound (denatured) globin and a sevenfold enhancement of surface-associated autologous IgG. Interestingly, dog RBCs that were allowed to senesce for 115 days in vivo also suffered from compromised intracellular reducing power, containing only 30% of the reduced glutathione found in unfractionated cells. Although the small quantity of cells of age ≥110 days did not allow direct quantitation of band 3 clustering, it was nevertheless possible to exploit single-cell microdeformation methods to evaluate the fraction of band 3 molecules that had lost their normal skeletal linkages and were free to cluster in response to hemichrome binding. Importantly, band 3 in RBCs ≥112 days old was found to be 25% less restrained by skeletal interactions than band 3 in control cells, indicating that the normal linkages between band 3 and the membrane skeleton had been substantially disrupted. Interestingly, the protein 4.1a/protein 4.1b ratio, commonly assumed to reflect RBC age, was found to be maximal in RBCs isolated only 58 days after labeling, implying that while this marker is useful for identifying very young populations of RBCs, it is not a very sensitive marker for canine senescent RBCs. Taken together, these data argue that several of the readily testable elements of the above hypothesis implicating band 3 in human RBC senescence can be validated in an appropriate canine model.
Age Is Not a Prognostic Variable With Autotransplants for Multiple Myeloma
Authors: Siegel D.S. , Desikan K.R. , Mehta J. , Singhal S. , Fassas A. , Munshi N. , Anaissie E. , Naucke S. , Ayers D. , Spoon D. , Vesole D. , Tricot G. , Barlogie B. 
Published: October 2019

AbstractMultiple myeloma (MM) typically afflicts elderly patients with a median age of 65 years. However, while recently shown to provide superior outcome to standard treatment, high-dose therapy (HDT) has usually been limited to patients up to 65 years. Among 550 patients with MM and a minimum follow-up of 18 months, 49 aged ≥65 years were identified (median age, 67; range, 65 to 76 years). Their outcome was compared with 49 younger pair mates (median, 52; range, 37 to 64 years) selected among the remaining 501 younger patients (&lt;65 years) matched for five previously recognized critical prognostic factors (cytogenetics, β2-microglobulin, C-reactive protein, albumin, creatinine). Nearly one half had been treated for more than 1 year with standard therapy and about one third had refractory MM. All patients received high-dose melphalan-based therapy; 76% of the younger and 65% of the older group completed a second transplant (P = .3). Sufficient peripheral blood stem cells to support two HDT cycles (CD34 &gt; 5 × 106/kg) were available in 83% of younger and 73% of older patients (P = .2). After HDT, hematopoietic recovery to critical levels of granulocytes (&gt;500/μL) and of platelets (&gt;50,000/μL) proceeded at comparable rates among younger and older subjects with both first and second HDT. The frequency of extramedullary toxicities was comparable. Treatment-related mortality with the first HDT cycle was 2% in younger and 8% among older subjects, whereas no mortality was encountered with the second transplant procedure. Comparing younger/older subjects, median durations of event-free and overall survival were 2.8/1.5 years (P = .2) and 4.8/3.3 years (P = .4). Multivariate analysis showed pretransplant cytogenetics and β2-microglobulin levels as critical prognostic features for both event-free and overall survival, whereas age was insignificant for both endpoints (P = .2/.8). Thus, age is not a biologically adverse parameter for patients with MM receiving high-dose melphalan-based therapy with peripheral blood stem cell support and, hence, should not constitute an exclusion criterion for participation in what appears to be superior therapy for symptomatic MM.
Low Platelet 2β1 Levels in Type I von Willebrand Disease Correlate With Impaired Platelet Function in a High Shear Stress System
Authors: Di Paola Jorge , Federici Augusto B. , Mannucci P.M. , Canciani Maria T. , Kritzik Marcie , Kunicki Thomas J. , Nugent Diane 
Published: October 2019

AbstractPlatelet adhesion to collagen-coated surfaces in whole blood under flow conditions is mediated by both von Willebrand factor (vWF)-dependent recruitment of the platelet glycoprotein Ib-IX receptor complex and collagen interaction with the integrin 2β1. In type 1 von Willebrand disease (vWD), platelet adhesive functions are impaired due to the decrease in vWF levels in plasma and platelets. There are at least three alleles of the human 2 gene, distinguishable by a cluster of silent or noncoding sequence differences within a segment of the gene. Two alleles, associated with low receptor density can be distinguished by nucleotide 807C, while the third allele associated with high receptor density, expresses nucleotide 807T. Gene frequencies of these alleles in a normal population (n = 167) are 0.58 for 807C and 0.42 for 807T. We measured the frequencies of these alleles in symptomatic patients with five types of vWD (type 1, n = 78; type 2A, n = 25, type 2B, n = 14; type 2M, n = 10; and type 3, n = 20). Compared with the normal group, no significant difference in allele frequencies was observed among individuals with types 2A, 2B, 2M, or 3 vWD. However, the frequency of the 807C allele, associated with low collagen receptor density, among type 1 vWD patients (807C = .71; 807T = .29) was significantly higher than that of the normal population (P = .007). Also, in patients with vWD type 1 and borderline to normal ristocetin-cofactor (vWF:RCo) activity values, collagen receptor density correlates inversely with closure time in a high shear stress system (platelet function analyzer [PFA-100]). We propose that low platelet 2β1 density results in less efficient primary platelet adhesion and may result in increased tendency to bleed, as evidenced by the high frequency of this polymorphism in patients with type 1 vWD compared with normal individuals. In addition, this may account for the variability between patients with similar levels of vWF antigen, but strikingly different bleeding histories.
The 2 Gene Coding Sequence T807/A873 of the Platelet Collagen Receptor Integrin 2β1 Might Be a Genetic Risk Factor for the Development of Stroke in Younger Patients
Authors: Carlsson Lena E. , Santoso Sentot , Spitzer Carsten , Kessler Christof , Greinacher Andreas 
Published: October 2019

Abstract
The polymorphisms C807T and G873A of the platelet integrin 2β1 (collagen receptor glycoprotein [GP] Ia-IIa) are linked to the expression density of this receptor. The GPIa T807/A873 allele causes a higher receptor expression, enhancing platelet binding to collagen. This might present a genetic predisposition for the development of thromboembolic complications. In this case-control study, the genotypes of the GPIa C807T polymorphism and presence of conventional risk factors (hypertension, diabetes mellitus, and smoking) were compared in stroke patients and patients without cerebrovascular disease (non-CVD patients) ≤50 years of age (n = 45 and 41, respectively) and in stroke patients and non-CVD patients more than 50 years of age (n = 182 and 129, respectively. In patients ≤50 years of age, the T807 allele was the only overrepresented variable (P = .023; odds ratio, 3.02; 95% confidence interval, 1.20 to 7.61) and an independent risk factor, whereas the presence of conventional risk factors was similar between stroke patients ≤50 years of age and non-CVD patients ≤50 years of age. Large epidemiological studies should prove whether the platelet collagen receptor GPIa-IIa T807 allele is an independent risk factor for the development of stroke in younger patients.
A Common Signaling Pathway Via Syk and Lyn Tyrosine Kinases Generated From Capping of the Sialomucins CD34 and CD43 in Immature Hematopoietic Cells
Authors: Tada Jun-ichi , Omine Mitsuhiro , Suda Toshio , Yamaguchi Naoto 
Published: October 2019

AbstractThe sialomucin CD34 is a useful marker for hematopoietic stem/progenitor cells. However, the role of CD34 remains poorly understood. Here we investigate the functions of CD34 and another sialomucin CD43 coexpressed on hematopoietic stem/progenitor cells. Stimulation of undifferentiated hematopoietic KG1a cells with anti-CD34 or anti-CD43 induced homotypic cytoadhesion, accompanied by formation of a long-lived cap of CD34 and CD43 respectively, which colocalized with F-actin. Stimulation with either antibody specifically increased tyrosine phosphorylation of the identical set of proteins of Lyn, Syk, pp60, pp69, and pp77 at the capping site. These events were similar to those observed in monocytic U937 cells ectopically expressing CD34. After stimulation of KG1a cells, coimmunoprecipitation of Lyn with pp69 and pp77 and of Syk with pp37 was detected in the membrane fraction. Blockade of antibody-induced cap formation by treatment with cytochalasin D leads to inhibition of tyrosine phosphorylation of Syk and pp77 and homotypic cytoadhesion. Moreover, normal human CD34+ bone marrow cells showed cap formation of CD34 or CD43 after stimulation. These results suggest that crosslinking of either CD34 or CD43 activates the same signaling pathway for cytoadhesion through Lyn, Syk, and the novel tyrosine-phosphorylated proteins within hematopoiesis.