bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thrombosis and Secondary Hemochromatosis Play Major Roles in the Pathogenesis of Jaundiced and Spherocytic Mice, Murine Models for Hereditary Spherocytosis
Authors: Kaysser Tamma M. , Wandersee Nancy J. , Bronson Rod T. , Barker Jane E. 
Published: October 2019

AbstractJaundiced mice, ja/ja, suffer from a severe hemolytic anemia caused by a complete deficiency of erythroid β-spectrin. We used these mice as a model to investigate the pathophysiological consequences of the deficiency, including the effects in the nonerythroid tissues where this protein is expressed. Because the ja/ja mice rarely survive beyond the fourth postnatal day, methods were assessed for extending lifespan into adulthood. Neonatal transfusion increased lifespan to a mean of 3.7 months, allowing a more complete characterization of the pathophysiology. Blood parameters and histopathology of the jaundiced mouse were compared with that from spherocytic mice, which have a hemolytic anemia caused by deficiency of erythroid α-spectrin, yet can survive the postnatal period transfusion free. The adult jaundiced and spherocytic mice present with greatly decreased hematocrit and red blood cell counts, reticulocytosis, and bilirubinemia, leading secondarily to hepatosplenomegaly and cardiomegaly. Jaundiced and spherocytic mice were analyzed histopathologically between 1.0 and 9.5 months of age. Interestingly, the complete absence of erythroid β-spectrin in jaundiced mice leads to no detectable structural defects in brain, cardiac, or skeletal muscles. However, fibrotic lesions and lymphocytic infiltration were observed in cardiac tissue from 4 of 13 jaundiced mice and 15 of 15 spherocytic mice, and thrombi were detected at either the atrioventricular valves or within the atria of 2 of 13 jaundiced mice and 15 of 15 spherocytic mice. In addition, all affected mice had a progressive renal hemosiderosis concurrent with hydronephrosis and glomerulonephritis. The severity of the renal disease and its presence in all moribund mice suggests kidney failure rather than the fibrotic heart lesions as the major cause of death in these mice.
Distinct Recirculating and Non-Recirculating B-Lymphocyte Pools in the Peripheral Blood Are Defined by Coordinated Expression of CD21 and L-Selectin
Authors: Young Alan J. , Marston Wendy L. , Dessing Mark , Dudler Lisbeth , Hein Wayne R. 
Published: October 2019

AbstractThe continual recirculation of lymphocytes between the blood, tissues, and lymph is essential for the coordination and dissemination of immune responses. We have compared the functional and phenotypic properties of lymphocytes isolated from blood and lymph, the two major migratory populations. Lymph-borne lymphocytes migrated readily into the lymphatic recirculation pathway, but greater than one third of all peripheral blood lymphocytes (PBLs) were excluded from the lymphatic circuit and showed an enhanced migration to the spleen. Phenotypic analysis showed that most non-recirculating PBLs were B cells. The migration competence of B cells correlated with the surface expression of CD21 and L-selectin; recirculating B cells expressed both of these molecules, whereas non-recirculating B cells lacked both antigens. These results establish that blood contains distinct pools of lymphocytes that differ in their recirculation competence. Clearly, blood sampling is not an efficient method to directly measure the status of the recirculating immune system, and implies important constraints and restrictions in the interpretation of experimental or clinical data that include phenotypic and quantitative analyses of blood lymphocytes.
A Specific Stimulator of Granulocyte Colony-Stimulating Factor Accelerates Recovery From Cyclophosphamide-Induced Neutropenia in the Mouse
Authors: Fine Jay S. , Cai Xiao-Yan , Justice Luminita , Gommoll Carl P. , Hamilton Linda D. , Waters Tracey A. , Narula Satwant K. , Bober Loretta A. , Grace Michael J. 
Published: October 2019

AbstractWe have identified a small molecular weight compound, SCH 14988, which specifically stimulates in vitro granulocyte-colony stimulating factor (G-CSF ) production from activated human peripheral blood mononuclear cells and monocytes but not other cytokines or CSFs with hematoregulatory activity. In vivo administration of SCH 14988 to mice rendered neutropenic by cyclophosphamide treatment resulted in the accelerated recovery of the peripheral neutrophil compartment. This activity correlated with increased in vivo G-CSF levels and stimulation of marrow granulopoiesis, and was comparable to that of exogenously administered recombinant human G-CSF. No alterations to other leukocyte populations in peripheral blood, spleen, or the peritoneal cavity were observed. These findings suggest that SCH 14988 may be clinically useful to enhance neutrophil granulopoiesis, as well as to study the mechanisms involved in G-CSF gene regulation.
Constitutive Expression of a CD44 Variant Isoform on T Cells Facilitates Regaining of Immunocompetence in Allogeneic Bone Marrow Transplantation
Authors: Zöller Margot , Schmidt Annette , Denzel Angela , Moll Jürgen 
Published: October 2019

AbstractConstitutive expression of a rat CD44 variant isoform, rCD44v4-v7, on murine T cells accelerates immune responsiveness. Because prolonged immunodeficiency can be a major drawback in allogeneic bone marrow transplantation, we considered it of special interest to see whether repopulation of lethally irradiated syngeneic and allogeneic mice may be influenced by constitutive expression of the rCD44v4-v7 transgene. When lethally irradiated syngeneic and allogeneic mice were reconstituted with bone marrow cells (BMC) from rCD44v4-v7 transgenic (TG) or nontransgenic (NTG) mice, the former had a clear repopulation advantage: thymocytes expanded earlier after reconstitution and, as a consequence, higher numbers of lymphocytes were recovered from spleen and lymph nodes. Lymphocytes also displayed functional activity in advance to those from mice reconstituted with BMC from NTG mice. Most importantly, after the transfer of BMC from TG mice into an allogeneic host, the frequency of host-reactive T cells decreased rapidly. Apparently, this was due to accelerated induction of tolerance. Because these effects were counterregulated by an rCD44v6-specific antibody, it is likely that they could be attributed to the rCD44v4-v7 TG product. Thus, expression of a CD44 variant isoform at high levels facilitated reconstitution with allogeneic BMC by accelerated establishment of tolerance and the regaining of immunocompetence.
Endogenously Produced Nitric Oxide Increases Tumor Necrosis Factor-α Production in Transfected Human U937 Cells
Authors: Yan Liang , Wang Shuibang , Rafferty Steven P. , Wesley Robert A. , Danner Robert L. 
Published: October 2019

AbstractVarious functions of human phagocytes are modulated by nitric oxide (NO). We transfected the human U937 monoblastoid cell line with an expression vector containing human endothelial NO synthase (eNOS) or murine inducible NOS (iNOS) cDNA to study the regulatory role of NO without the nonspecific effects associated with exogenous NO sources. Western blot confirmed expression of eNOS or iNOS in respectively transfected cells, but not in naive or empty-vector transfected cells. Transfectants expressing iNOS, a calcium-independent enzyme, but not eNOS, a calcium-dependent enzyme, spontaneously produced NO (P &lt; .001). The NO release from iNOS-transfected cells, as measured by nitrite and nitrate accumulation and by cyclic guanosine monophosphate (cGMP) increases in rat reporter cells, was inhibitable (P &lt; .01 for both) with Nω-methyl-L-arginine (L-NMA), a NOS inhibitor. The eNOS transfectants were shown to contain functional enzyme by the conversion of L-arginine to L-citrulline in fractionated cells (P = .0001) and by exposing intact cells to calcium ionophore using the cGMP reporter cell assay (P = .0001). After differentiation with phorbol-12-myristate-13-acetate (PMA), iNOS transfectants produced more tumor necrosis factor-α (TNF-α) (124.9 ± 25.4 pg/5 × 105 cells per 24 hours) than did empty-vector transfected cells (21.9 ± 1.9 pg/5 × 105 cells per 24 hours; P = .02). This effect was inhibited by 500 μmol/L L-NMA (54.4 ± 3.1 pg/5 × 105 cells per 24 hours; P = .05). However, in the presence of high concentrations of lipopolysaccharide (1 μg/mL), which further increased NO production in iNOS transfected cells (P = .044), TNF-α production was similar comparing PMA-differentiated iNOS and empty-vector transfectants (12.2 ± 0.8 and 13.1 ± 1.7 ng/5 × 105 cells per 24 hours, respectively; P = .5). The results show that under certain conditions endogenously produced NO can upregulate TNF-α production in human phagocytes.
Epstein-Barr Virus Latent Gene Expression in Primary Effusion Lymphomas Containing Kaposi's Sarcoma–Associated Herpesvirus/Human Herpesvirus-8
Authors: Horenstein Marcelo G. , Nador Roland G. , Chadburn Amy , Hyjek Elizabeth M. , Inghirami Giorgio , Knowles Daniel M. , Cesarman Ethel 
Published: October 2019

Abstract
Primary effusion (body cavity–based) lymphoma (PEL) is a recently recognized subtype of malignant lymphoma that exhibits distinctive clinical and biological features, most notably its usual infection with the Kaposi's sarcoma–associated herpesvirus (KSHV). The vast majority of cases also contain Epstein-Barr virus (EBV). This dual viral infection is the first example of a consistent dual herpesviral infection in a human neoplasm and provides a unique model to study viral interactions. We analyzed the pattern of EBV latent gene expression to determine the pathogenic role of this agent in PELs. We examined five PELs coinfected with EBV and KSHV by reverse transcription-polymerase chain reaction (RT-PCR), in situ hybridization, and immunohistochemistry. EBER1 mRNA, a consistent marker of viral latency, was positive in all PEL cases, although at lower levels than in the non-PEL controls due to EBER1 expression by only a variable subset of lymphoma cells. Qp-initiated mRNA, encoding only EBNA1 and characteristic of latencies I and II, was positive in all PEL cases. Wp- and Cp-initiated mRNAs, encoding all EBNAs and characteristic of latency III, were negative in all cases. LMP1 mRNA, expressed in latencies II and III, was present in three cases of PEL, although at very low levels that were not detectable at the protein level by immunohistochemistry. Low levels of LMP2A mRNA were detected in all cases. BZLF1, an early-intermediate lytic phase marker, was weakly positive in four cases, suggesting a productive viral infection in a very small proportion of cells, which was confirmed by ZEBRA antigen expression. Therefore, PELs exhibit a restricted latency pattern, with expression of EBNA1 in all cases, and low LMP1 and LMP2A levels.
Chronic Hepatitis C Virus Infection After Treatment for Pediatric Malignancy
Authors: Cesaro Simone , Petris Maria Grazia , Rossetti Flavio , Cusinato Riccardo , Pipan Corrado , Guido Maria , Masiero Lucia , Botta Giuseppe A. , Meloni Giovanni A. , Zanesco Luigi 
Published: October 2019

Abstract
Sera of 658 patients who had completed treatment for pediatric malignancy were analyzed by a second-generation enzyme-linked immunosorbent assay and recombinant immunoblot assay test to assess the prevalence of hepatitis C virus (HCV)-seropositivity. All HCV-seropositive patients underwent detailed clinical, laboratory, virologic, and histologic study to analyze the course of HCV infection. One hundred seventeen of the 658 patients (17.8%) were positive for HCV infection markers. Among the 117 anti-HCV+ patients, 41 (35%) were also positive for markers of hepatitis B virus infection with or without delta virus infection markers, 91 (77.8%) had previously received blood product transfusions, and 25 (21.4%) showed a normal alanine aminotransferase (ALT) level during the last 5-year follow-up (11 of them never had abnormal ALT levels). The remaining 92 patients showed ALT levels higher than the upper limit of normal range. Eighty-one of 117 (70%) anti-HCV+ patients were HCV-RNA+, with genotype 1b being present in most patients (54%). In univariate analysis, no risk factor for chronic liver disease was statistically significant. In this study, the prevalence of HCV infection was high in patients who were treated for a childhood malignancy. In about 20% of anti-HCV+ patients, routes other than blood transfusions are to be considered in the epidemiology of HCV infection. After a 14-year median follow-up, chronic liver disease of anti-HCV+ positive patients did not show progression to liver failure.
Recombinant Retroviruses Pseudotyped With the Vesicular Stomatitis Virus G Glycoprotein Mediate Both Stable Gene Transfer and Pseudotransduction in Human Peripheral Blood Lymphocytes
Authors: Gallardo H.F. , Tan C. , Ory D. , Sadelain M. 
Published: October 2019

AbstractIt is essential for the study of T-cell function and the improvement of adoptive cell therapies to efficiently generate large populations of human primary T cells that reliably express foreign genes. This goal is achieved by using recombinant retroviruses pseudotyped with either the gibbon ape leukemia virus (GaLV) envelope or the vesicular stomatitis virus G (VSV-G) glycoprotein. We show here that both retroviral particles mediate stable gene transfer in CD4+ and in CD8+ peripheral blood lymphocytes cultured under optimized conditions. However, VSV-G–pseudotyped virions may cause transduction artifacts that must be carefully excluded. The VSV-G virions require 10- to 100-fold higher concentrations of infectious particles to achieve levels of gene transfer comparable to GaLV-virions. Nonetheless, the physical stability of VSV-G–coated particles enables the concentration of viral stocks to 109 infectious particles per milliliter or more.
Human Immunodeficiency Virus-1 Entry Into Purified Blood Dendritic Cells Through CC and CXC Chemokine Coreceptors
Authors: Ayehunie Seyoum , Garcia-Zepeda Eduardo A. , Hoxie James A. , Horuk Richard , Kupper Thomas S. , Luster Andrew D. , Ruprecht Ruth M. 
Published: October 2019

AbstractBlood dendritic cells (DC) are susceptible to both macrophage (M) and T-cell line (T) tropic human immunodeficiency virus type 1. The CC chemokines RANTES, macrophage inflammatory protein-1α (MIP-1α), MIP-1β, eotaxin, and, to a lesser extent, monocyte chemoattractant protein-1 (MCP-1) and MCP-4 blocked entry of M-tropic virus into blood DC. The CXC chemokine, SDF-1, a fusin (CXCR4 chemokine receptor) ligand, and an antifusin antibody inhibited DC entry by T-tropic virus. Purified blood DC contained CCR1, CCR2, CCR3, and CCR5 as well as the CXCR4 chemokine receptor RNA transcripts and high levels of fusin on the cell surface. The coexpression of multiple chemokine receptors offers a molecular mechanism to explain the permissiveness of DC for both M- and T-tropic viruses.
Modulation of Cytokine Release and Neutrophil Function by Granulocyte Colony-Stimulating Factor During Endotoxemia in Humans
Authors: Pajkrt Dasja , Manten Annemieke , van der Poll Tom , Tiel-van Buul Monique M.C. , Jansen Jaap , Wouter ten Cate Jan , J.H. van Deventer Sander 
Published: October 2019

AbstractIn this double-blind, cross-over, placebo-controlled, randomized study, two groups of eight healthy male volunteers were challenged with endotoxin (4 ng/kg) on two occasions, once in conjunction with placebo and once with granulocyte colony-stimulating factor (G-CSF; 5 μg/kg). In group 1, G-CSF was administered intravenously 2 hours before endotoxin challenge; in group 2, G-CSF was administered subcutaneously 24 hours before endotoxin challenge. In group 1, G-CSF significantly enhanced the release of tumor necrosis factor (TNF ), interleukin-6 (IL-6), IL-8, IL-1 receptor antagonist (IL-1ra), and soluble TNF receptors. In group 2, G-CSF significantly reduced IL-8 concentrations and modestly attenuated TNF and IL-6 levels. In this group, IL-1ra and soluble TNF receptors were enhanced by G-CSF pretreatment and lipopolysaccharide (LPS)-induced soluble TNF receptor release was further augmented, whereas LPS-induced IL-1ra concentrations remained unaltered. Both pretreatments with G-CSF increased LPS-induced peripheral neutrophilia; the expression of CD11b, CD18, and CD67; and the release of elastase and lactoferrin. Both pretreatments also downregulated neutrophil L-selectin expression and prevented the endotoxin-induced pulmonary neutrophil accumulation during the first 2 hours after endotoxin challenge. These data indicate that two different pretreatments with G-CSF result in differential effects on LPS-induced cytokine release but similar effects on LPS-induced neutrophil activation and changes in expression of cell surface molecules. Finally, regardless of the effects of G-CSF on LPS-induced cytokine release, G-CSF blocks LPS-induced pulmonary granulocyte accumulation.
Hematopoietic-Specific Genes Are Not Induced During In Vitro Differentiation of scl-Null Embryonic Stem Cells
Authors: Elefanty Andrew G. , Robb Lorraine , Birner Raquella , Begley C. Glenn 
Published: October 2019

AbstractThe helix-loop-helix transcription factor, scl, plays an essential role in hematopoietic development. Embryos in which the gene has been disrupted fail to develop yolk sac erythropoiesis, and scl-null embryonic stem cells do not contribute to hematopoiesis in chimeric mice. To analyze the molecular consequences of scl deficiency, we compared the gene expression profiles of control (wild-type and scl-heterozygous) and scl-null embryonic stem cells differentiated in vitro for up to 12 days. In control and scl-null embryoid bodies the temporal expression pattern of genes associated with the formation of ventral mesoderm, such as Brachyury, bone morphogenetic protein-4, and flk-1, was identical. Similarly, GATA-2, CD34, and c-kit, which are coexpressed in endothelial and hematopoietic lineages, were expressed normally in scl-null embryonic stem cell lines. However, hematopoietic-restricted genes, including the transcription factors GATA-1, EKLF, and PU.1 as well as globin genes and myeloperoxidase, were only expressed in wild-type and scl-heterozygous embryonic stem cells. Indirect immunofluorescence was used to confirm the observations that GATA-1 and globins were only present in control embryoid bodies but that CD34 was found on both control and scl-null embryoid bodies. These data extend the previous gene ablation studies and support a model whereby scl is absolutely required for commitment of a putative hemangioblast to the hematopoietic lineage but that it is dispensable for endothelial differentiation.
Platelet Adhesion to Collagen Under Flow Causes Dissociation of a Phosphoprotein Complex of Heat-Shock Proteins and Protein Phosphatase 1
Authors: Polanowska-Grabowska Renata , Simon Carl G. , Falchetto Rocco , Shabanowitz Jeffrey , Hunt Donald F. , Gear Adrian R.L. 
Published: October 2019

AbstractPhosphorylation/dephosphorylation events in human blood platelets were investigated during their adhesion to collagen under flow conditions. Using 32P-labeled platelets and one-dimensional gel electrophoresis, we found that adhesion to collagen mediated primarily by the α2β1 integrin resulted in a strong dephosphorylation of several protein bands. Neither adhesion to polylysine nor thrombin-induced aggregation caused similar protein dephosphorylation. In addition, treatment with okadaic acid (OA), an inhibitor of serine/threonine protein phosphatases type 1 (PP1) and 2A (PP2A), caused significant inhibition of adhesion, suggesting that adhesion is regulated by OA-sensitive phosphatases. Recent studies indicate that phosphatases may be associated with the heat-shock proteins. Immunoprecipitations with antibodies against either the heat-shock cognate protein 70 (hsc70) or heat-shock protein 90 (hsp90) showed the presence of a phosphoprotein complex in 32P-labeled, resting human platelets. Antibody probing of this complex detected hsc70, hsp90, two isoforms of the catalytic subunit of PP1, PP1Cα and PP1Cδ, as well as the M regulatory subunit of PP1 (PP1M). OA, at concentrations that markedly blocked platelet adhesion to collagen, caused hyperphosphorylation of the hsc70 complex. In platelets adhering to collagen, hsc70 was completely dephosphorylated and hsp90, PP1α, and PP1M were dissociated from the complex, suggesting involvement of heat-shock proteins and protein phosphatases in platelet adhesion.
Anticoagulant Effects of Synthetic Retinoids Mediated Via Different Receptors on Human Leukemia and Umbilical Vein Endothelial Cells
Authors: Shibakura Misako , Koyama Takatoshi , Saito Takako , Shudo Koichi , Miyasaka Nobuyuki , Kamiyama Ryuichi , Hirosawa Shinsaku 
Published: October 2019

AbstractWe recently found that retinoic acids (RAs) exert anticoagulant effects by upregulating thrombomodulin (TM) and downregulating tissue factor (TF ) expression in acute promyelocytic leukemia (APL) cells and monoblastic leukemia cells. Two classes of nuclear RA receptors, termed retinoic acid receptors (RARs) and retinoid X receptors, have been identified. Each receptor class consists of three subtypes. In the present study, we have used several synthetic retinoids to determine which receptor subtypes are involved in the regulation of TM and TF expression in NB4 APL cells, U937 monoblastic leukemia cells, and human umbilical vein endothelial cells (HUVECs). Am80, which has no binding affinity for RARγ, and Ch55, which does not bind to cytoplasmic retinoic acid binding protein (CRABP), upregulated TM and downregulated TF in NB4 and U937 cells, similar to all-trans RA (ATRA). A specific RARα antagonist, Ro41-5253, significantly suppressed the upregulation of TM by ATRA and Am80 in NB4 cells, U937 cells, and HUVECs. In contrast, only with preincubation with both RARα and RARβ antagonists was downregulation of TF by retinoids suppressed in NB4 cells. These findings indicate that the mechanism of transactivation and transrepression functions of RARs are distinct and also elucidate the major role of RARα in TM upregulation by retinoids in leukemic cells and HUVECs and the cooperation of RARα and RARβ in TF downregulation by retinoids. They also indicate that binding to CRABP is not required for the anticoagulant effect of retinoids and that synthetic retinoids will prove very useful in controlling distinct targets, the TM and TF genes, at the level of transcription, and will permit the development of retinoids with a new type of anticoagulant effect.