bluuebunny/crossref_metadata_2025_split huggingface dataset:
Endotoxin-induced tissue factor messenger RNA in human monocytes is negatively regulated by a cyclic AMP-dependent mechanism
Authors: Ollivier V , Houssaye S , Ternisien C , Leon A , de Verneuil H , Elbim C , Mackman N , Edgington TS , de Prost D 
Published: October 2019

Abstract
Tissue factor (TF) is a transmembrane receptor that serves as the major cofactor for factor VIIa-catalyzed proteolytic activation of factors IX and X. In response to bacterial lipopolysaccharide (LPS), monocytes transcribe, synthesize, and express TF on their surface, thereby conveying to activated monocytes the ability to initiate the blood coagulation protease cascades. Agents that elevate cellular cyclic AMP (cAMP) inhibit the functional expression of TF by LPS-stimulated monocytes. In this study, we investigated the mechanism of this suppression. Northern blot analysis of total RNA from LPS-stimulated monocytes showed a concentration-dependent decrease in TF messenger RNA (mRNA) levels in response to dibutyryl-cAMP (dBt-cAMP). TF mRNA and procoagulant activity were inhibited as early as 1 hour after the addition of dBt-cAMP and the inhibition persisted through 4 hours. Suppression of specific mRNA abundance was also observed with agents, including forskolin and iso-butyl-methyl-xanthine (IBMX), that increase cAMP levels by independent mechanisms. Flow immunocytometric analysis confirmed that cell-surface TF protein levels declined in parallel with TF functional activity. The rate of decay of TF mRNA after the arrest of transcription by actinomycin D was not altered by the addition of dBt-cAMP, IBMX, or forskolin, thus excluding effects on TF mRNA stability. We conclude that elevated cAMP levels suppress TF mRNA by reducing the rate of TF gene transcription.
Interferon-alpha in mixed cryoglobulinemia patients: a randomized, crossover-controlled trial
Authors: Ferri C , Marzo E , Longombardo G , Lombardini F , La Civita L , Vanacore R , Liberati AM , Gerli R , Greco F , Moretti A 
Published: October 2019

Abstract
The effects of interferon-alpha (IFN-alpha) on clinical and serologic manifestations of mixed cryoglobulinemia (MC) were investigated by randomized, crossover-controlled trial in 26 patients. The trial alternated 6 months with and 6 months without IFN-alpha therapy (2 x 10(6) IU daily for a month, then every other day for 5 months). In 22 patients, pretreatment steroid dosage remained unchanged during the study. Six patients dropped out (three because of side effects), whereas another 20 patients experienced a significant improvement of purpura (P < .02) and serum transaminases (P < .005) during IFN-alpha treatment. The presence of clinical improvement was supported by the outcome measurements of several immunologic parameters. In particular, serum cryoglobulins were significantly reduced (P < .04) during IFN- alpha therapy. A rebound phenomenon of clinical and serologic parameters was observed after IFN-alpha discontinuation. In addition, no variations were recorded during 6 months without therapy. Hepatitis C virus (HCV) RNA was detected in 91% (20/22) of our MC patients; in 2/13 cases HCV RNA was no longer detectable in serum samples after IFN- alpha therapy. Thus, IFN-alpha could be considered as treatment for MC in patients with HCV seropositivity.
Mast cells and their committed precursors are not required for interleukin-3-induced histamine synthesis in murine bone marrow: characteristics of histamine-producing cells
Authors: Schneider E , Ploemacher RE , Nabarra B , Brons NH , Dy M 
Published: October 2019

Abstract
In the present study we investigate the nature of the murine bone marrow cell subset responsible for the marked increase in histamine synthesis induced by interleukin-3 (IL-3). Because mast cells, and eventually their committed precursors, represent a potential source of histamine in this context, we examined their possible participation in this biologic activity with particular attention. We provide evidence that neither of these populations respond to IL-3 in terms of histamine synthesis and that other differentiated end cells or stromal components of the bone marrow are also not involved in this phenomenon. Starting from these findings, we further characterized the immature hematopoietic compartment responsible for IL-3-induced histamine synthesis using fluorescence-activated cell sorter (FACS) sorting based on rhodamine retention or wheat germ agglutinin (WGA) affinity. These procedures have allowed us to ascribe the following features to histamine-producing cells: (1) They belong to a low-density, progenitor- enriched bone marrow subset containing cells of relatively important size and internal structure. (2) The highest histamine levels are generated by the rhodamine-bright fraction of this population, while the most primitive rhodamine-dull cells do not express this biologic activity. (3) Histamine-producing cells do not copurify with colony- forming units in spleen day 7 and day 12 in WGA-bright fractions. (4) Their enrichment is associated with increased frequencies of cells forming colonies in methylcellulose (CFU-C), suggesting the involvement of several progenitors with partially limited differentiation potential in this biologic activity.
Bone marrow clones representing an intermediate stage of development between hematopoietic stem cells and pro-T-lymphocyte or pro-B- lymphocyte progenitors
Authors: Palacios R , Samaridis J 
Published: October 2019

Abstract
We have established in culture several nontransformed bone marrow clones (called PR) that show phenotypic and genotypic characteristics that distinguish them from totipotent stem cells and lineage-restricted Pro-T lymphocytes, Pro-B lymphocytes, and myeloid cell progenitors. In vivo and/or in vitro the PR clones give rise to T lymphocytes, B lymphocytes, and some myeloid-lineage cells, but they appear not to be able to generate cells of the erythroid lineage, nor can they rescue mice from a lethal dose of irradiation. We conclude that the PR clones are precursor cells representing an intermediate stage of development between the totipotential stem cell and lineage-restricted progenitor cells. The results described here support a model of blood cell formation in which stem cell differentiation is a progressive process marked by the stepwise loss of self renewal and functional potential. In addition, they provide evidence that cytokines and specialized microenvironments can direct the fate of the developing multipotent progenitor cells.
Regulation of fibrinolysis by platelet-released plasminogen activator inhibitor 1: light scattering and ultrastructural examination of lysis of a model platelet-fibrin thrombus
Authors: Braaten JV , Handt S , Jerome WG , Kirkpatrick J , Lewis JC , Hantgan RR 
Published: October 2019

Abstract
We have investigated the role of plasminogen activator inhibitor 1 (PAI- 1) in the regulation of fibrinolysis using a model thrombus composed of thrombin-stimulated platelets, fibrin(ogen), plasminogen, and recombinant tissue-type plasminogen activator. Laser light scattering kinetic measurements showed that clot lysis was significantly delayed both by thrombin-stimulated platelets and their cell-free releasate. This delay in lysis was almost fully reversed by the addition of a PAI- 1-specific monoclonal antibody that blocks the ability of PAI-1 to inhibit plasminogen activators. Lysis half-times exhibited a linear dependence on the concentration of PAI-1 antigen present, as determined by enzyme-linked immunosorbent assay (ELISA). Sodium dodecylsulfate- polyacrylamide gel electrophoresis (SDS-PAGE) followed by immunoblotting confirmed the presence of PAI-1 antigen in the platelet releasates. Scanning electron micrographs of the model thrombus components sampled late in lysis showed considerable unproteolyzed fibrin still attached to platelets. Immunogold cytochemistry detected large amounts of PAI-1 antigen in the partially lysed platelet-fibrin thrombi. This PAI-1 appeared to be bound to the fibrin network rather than to the platelet surface itself. We conclude that the residual clots observed late in lysis represent platelet-associated fibrin to which platelet-released PAI-1 has bound, rendering it less susceptible to degradation.
Lack of CD24 antigen expression in B-lineage acute lymphoblastic leukemia is associated with intrinsic radiation resistance of primary clonogenic blasts
Authors: Uckun FM , Song CW 
Published: October 2019

Abstract
The radiation sensitivity of primary clonogenic blasts from 27 children with immunologically classified CD2-CD5-CD7-CD19+slg- B-lineage acute lymphoblastic leukemia (ALL) was analyzed using leukemic progenitor cell (LPC) colony assays. Radiation survival curves of primary clonogenic blasts (ie, LPC) were constructed for each patient using computer programs for the single-hit multitarget as well as the linear quadratic models of cell survival. The D0 values ranged from 49 to 891 cGy (median, 239 cGy; mean +/- SE, 307 +/- 44 cGy) and the alpha values ranged from 0.000 to 2.047 Gy-1 (median, 0.156 Gy-1; mean +/- SE, 0.284 +/- 0.078 Gy-1). Patients were divided into groups according to sex, age, white blood cell count (WBC) at diagnosis, plating efficiency of primary bone marrow blasts, and immunophenotype. Patient sex, age, WBC at diagnosis, or in vitro plating efficiency was not associated with radiation resistance. Notably, freshly isolated primary clonogenic blasts from patients with a CD19+CD24-CD34+ composite immunophenotype (stage I B-cell precursor [BCP]) had 2.2-fold higher D0 values (P = .005) and 3.4-fold lower alpha values (P = .05) than those from patients with a CD19+CD24+CD34+ (stage II BCP) or CD19+CD24+CD34- (stage III BCP) immunophenotype. The relative values for CD24- primary clonogenic blasts signify greater intrinsic radiation resistance. Furthermore, the CD19+CD24-CD34+ immunophenotype had a larger radiation resistant fraction. Whereas only 60% of CD19+CD24+CD34+ and 33% of CD19+CD24+CD34- cases had clonogenic blasts with alpha < or = 0.2, 100% of CD19+CD24-CD34+ cases had clonogenic blasts with alpha < or = 0.2. Furthermore, clonogenic blasts from established CD19+CD24- B-lineage ALL cell lines were significantly more radiation resistant than CD19+CD24+ B-lineage ALL cell lines. Notably, radiation doses sufficient to induce apoptosis of CD24- B-lineage ALL cells were higher than those capable of inducing apoptosis in CD24+ B-lineage ALL cells. Thus, the lack of CD24 surface antigen expression in B-lineage ALL is associated with intrinsic radiation resistance at the level of primary clonogenic blasts.
Evidence for restricted Epstein-Barr virus latent gene expression and anti-EBNA antibody response in solid organ transplant recipients with posttransplant lymphoproliferative disorders
Authors: Cen H , Williams PA , McWilliams HP , Breinig MC , Ho M , McKnight JL 
Published: October 2019

Abstract
Epstein-Barr virus (EBV) is associated with the development of two human B-cell malignancies, Burkitt's lymphoma and lymphomas that occur in the immunosuppressed host. The latter category of disease has become important recently as it is seen primarily in organ transplant recipients and individuals with acquired immunodeficiency syndrome. One possible mechanism for lymphoma development involves a reduction in or lack of EBV-specific cytotoxic T-cell recognition. In support of this model are previous observations that the expression of EBV nuclear antigen 2 (EBNA2) and latent membrane protein, two viral antigens associated with major histocompatibility complex class I-restricted T- cell killing, are downregulated in Burkitt's lymphoma and in early passage lymphoblastoid cell lines (LCL) derived from the malignant lesions. To determine whether a similar mechanism could occur in the development of posttransplant lymphoproliferative disorders (PTLD), we compared EBV gene expression among 23 PTLD tumor lesions obtained from 11 solid organ transplant recipients and among LCL derived from 3 of these lesions. In this report, we demonstrate, by Southern blot, Western blot, and immunofluorescence analysis, that (1) the tumor lesions exhibit varying patterns of restricted viral gene expression; (2) LCL derived from these lesions may represent the in vitro selection of cell subpopulations; and (3) immunosuppressed individuals have a markedly reduced antibody response to the latent cycle antigens, EBNA1, EBNA2, and EBNA-LP, but not to the lytic cycle viral capsid antigen when compared with normal immunocompetent controls.
Use of porcine factor VIII in the treatment of patients with acquired hemophilia
Authors: Morrison AE , Ludlam CA , Kessler C 
Published: October 2019

Abstract
Data have been collected from 47 centers in Europe and North America on the treatment with porcine factor VIII concentrate of 74 acute bleeding episodes in 65 patients with acquired hemophilia. The median initial anti-human factor VIII auto-antibody inhibitor level was 38 Bethesda unit (BU)/mL (range 1.2 to 1,024) whereas that against porcine was 1 BU/mL (range 0 to 15). The mean initial dose of porcine factor VIII infused was 84 IU/kg, which increased the plasma factor VIII:C activity by 0.85 IU/mL. Therapy was continued for a mean of 8.5 days during which time the average number of infusions was 11. Objective clinical responses were rated as good or excellent in 78% of recipients. Side effects were uncommon; only one patient experienced a severe anaphylactic reaction necessitating the discontinuation of porcine FVIII therapy. After therapy, no increase in the median level of anti- human FVIII or anti-porcine antibody was noted in the group as a whole, although 13 patients showed individual increases in either anti-human or anti-porcine antibody levels or both of more than 10 BU/mL. Of the 7 patients who subsequently rebled, 5 were successfully re-treated and 2 did not respond to further porcine factor VIII treatment. Porcine factor VIII is safe and clinically effective treatment for bleeding episodes associated with acquired hemophilia and should be considered as first-line therapy for patients whose acquired anti-factor VIII:C antibody cross-reacts with porcine factor VIII:C at low levels.
Expression of perforin and membrane-bound lymphotoxin (tumor necrosis factor-beta) in virus-specific CD4+ human cytotoxic T-cell clones
Authors: Yasukawa M , Yakushijin Y , Hasegawa H , Miyake M , Hitsumoto Y , Kimura S , Takeuchi N , Fujita S 
Published: October 2019

Abstract
In an attempt to clarify the mechanisms of cytotoxicity mediated by CD4+ cytotoxic T lymphocytes (CTL), the expression of perforin and membrane-bound lymphotoxin (LT) (tumor necrosis factor-beta) in herpes simplex virus (HSV)-specific CD4+ human cytotoxic and noncytotoxic T- cell clones was examined. Three HSV-specific CD4+ human CTL clones that showed HLA-DR-restricted cytotoxicity and proliferative response were established. The cytotoxicity of these clones in 5-hour 51Cr release assays was found to be mediated by the directional target cell lysis and not by the release of cytotoxic soluble factors, ie, “innocent bystander” killing. Northern blot analysis showed that messenger RNAs for perforin and LT, which were both considered to be important mediators for cytotoxicity of CD8+ CTL and natural killer cells, were abundantly expressed in HSV-specific CD4+ CTL clones. Expression of perforin in the cytoplasm of CD4+ CTL clones was also detected by immunohistochemical staining using a monoclonal antibody against perforin. In addition, LT bound to the cell surface of CD4+ CTL clones was detected by flow cytometry. In contrast, little or no expression of perforin and LT was detected in three HSV-specific CD4+ noncytotoxic T- cell clones. Although the cytotoxicity mediated by lymphokine-activated killer cells was partly inhibited by addition of anti-LT antibody, it did not show any effect on the cytotoxicity of HSV-specific CD4+ CTL clones. In addition, it was found that cytotoxicity mediated by these CD4+ CTL clones was Ca2(+)-dependent. These data thus suggest that perforin and membrane-bound LT are both expressed in HSV-specific CD4+ CTL, although perforin might be the more important mediator in short- term culture.
Molecular cloning of CD68, a human macrophage marker related to lysosomal glycoproteins
Authors: Holness CL , Simmons DL 
Published: October 2019

Abstract
CD68 is a 110-Kd transmembrane glycoprotein of unknown function highly expressed by human monocytes and tissue macrophages. We have isolated cDNA clones encoding CD68 from a U937 cDNA library by transient expression in COS cells and panning with the anti-CD68 monoclonal antibodies (MoAbs) Y2/131, Y1/82A, EBM11, and Ki-M6. CD68 transcripts are constitutively present in the promonocyte cell line U937 and are upregulated by phorbol myristic acid (PMA). By contrast, CD68 transcripts are absent or present at very low levels in many hematopoietic lines including KG1, CEM, and K562, but can be induced by exposure to PMA. The cDNA sequence predicts a type I integral membrane protein of 354 residues with a heavily glycosylated extracellular domain of 298 residues containing nine potential N-linked glycosylation sites and numerous potential O-linked glycosylation sites. The extracellular domain consists of two distinct regions separated by an extended proline hinge: a membrane-distal mucin-like domain containing short peptide repeats and consisting of 54% serine and threonine residues; and a membrane proximal domain that has significant sequence homology to a family of lysosomal/plasma membrane shuttling proteins known as the lamp 1 group. CD68 is a member of a growing family of hematopoietic mucin-like molecules, including leukosialin/CD43, the stem cell antigen CD34, and the lymph node high endothelial ligand for L-selectin GlyCAM-1.
Molecular cloning, chromosomal location, and tissue-specific expression of the murine cathepsin G gene
Authors: Heusel JW , Scarpati EM , Jenkins NA , Gilbert DJ , Copeland NG , Shapiro SD , Ley TJ 
Published: October 2019

Abstract
We previously have characterized a cluster of genes encoding cathepsin G (CG) and two other CG-like hematopoietic serine proteases, CGL-1 and CGL-2, on human chromosome 14. In this report, we clone and characterize a novel, related murine hematopoietic serine protease gene using human CG (hCG) cDNA as the probe. This murine gene spans approximately 2.5 kb of genomic DNA, is organized into five exons and four introns, and bears a high degree of homology to hCG at both nucleic acid (73%) and deduced amino acid (66%) levels. The predicted cDNA contains an open reading frame of 783 nucleotides that encodes a nascent protein of 261 amino acids. Processing of a putative signal (pre) peptide of 18 residues and an activation (pro) dipeptide would generate a mature enzyme of approximately 27 Kd that has an estimated pI of 12.0. Conserved residues at His44, Asp88, and Ser181 form the characteristic catalytic triad of the serine protease superfamily. The gene is tightly linked to the CTLA-1 locus on murine chromosome 14, where the serine protease genes mCCP1–4 are clustered. Expression of this gene is detected only in the bone marrow and is restricted to a small population of early myeloid cells. These findings are consistent with the identification of the gene encoding murine CG.
Expression of embryonic zeta-globin and epsilon-globin chains in a 10- year-old girl with congenital anemia
Authors: Tang W , Cai SP , Eng B , Poon MC , Waye JS , Illum N , Chui DH 
Published: October 2019

Abstract
A 10-year-old Danish girl with congenital anemia is described. At birth, she had severe anemia and erythroblastosis and was transfused a number of times during the first year. The need for transfusions has since declined steadily. Her reticulocyte counts varied between 2% and 15%, and her bone marrow aspirate showed some dyserythropoietic features. Her hemoglobin F level was consistently elevated, up to as much as 41%. Her erythrocytes had a normal level of I antigen but an undetectable level of i antigen. Moreover, embryonic zeta-globin and epsilon-globin chains were present in some of her circulating erythrocytes. These findings may represent the manifestations of a new variant of congenital anemia.
Human platelet aggregation by murine monoclonal antiplatelet antibodies is subtype-dependent
Authors: De Reys S , Blom C , Lepoudre B , Declerck PJ , De Ley M , Vermylen J , Deckmyn H 
Published: October 2019

Abstract
Twenty murine monoclonal antibodies (MoAbs) generated against different human platelet antigens induced clumping of human platelets in plasma and buffer. Whereas one MoAb could agglutinate platelets, clumping for 19 MoAbs was blocked by metabolic inhibitors, indicating that these induce platelet activation. Fifteen MoAbs were of IgG1, two of IgG2a, and two of IgG2b subtype. F(ab')2 fragments of these did not evoke an aggregatory response, but specifically inhibited aggregations by and binding of their respective intact MoAbs to platelets. Single-platelet counting technology indicated that the MoAbs bind through their antigen- binding and Fc domains mainly to the surface of the same platelet, rather than cause interplatelet-binding. Despite these similarities, the mechanism of action was nevertheless subtype-dependent. Aggregation induced by all IgG1 antibodies could consistently be prevented by blocking the Fc gamma II-receptor, whereas aggregations induced by all IgG2 antibodies still occurred with blocked Fc-receptor, provided functional complement was present. We therefore conclude that platelet activation by MoAb-binding is initiated by antigen recognition followed by an Fc domain-dependent step, which involves the Fc gamma II-receptor for IgG1-type MoAbs and complement-binding for IgG2-type MoAbs. Thus, antibodies of different subtypes can aggregate platelets via different pathways.
Complement and virus-specific antibody-dependent infection of normal B lymphocytes by human immunodeficiency virus type 1
Authors: Gras G , Richard Y , Roques P , Olivier R , Dormont D 
Published: October 2019

Abstract
We tested the susceptibility of human purified, normal B lymphocytes to human immunodeficiency virus type 1 (HIV-1) infection, in the presence or absence of complement-sufficient serum and of virus-specific antibodies. Virus replication was detected when cells were infected in the presence of both complement and anti-HIV antibodies (C'-ADE conditions), by day 2 postinfection. Similar results were obtained when B lymphocytes were purified either from peripheral blood (three healthy donors) or from tonsils (four individuals with chronic tonsillitis). HIV infection was shown by polymerase chain reaction (PCR) detection of proviral sequences (gag and pol genes), by p24 antigen synthesis, and by cocultivation assay with MT2 cells. The higher p24 production was obtained when B cells were preactivated for 2 days by phorbol 12- myristate 13-acetate (PMA) before infection and then cultured in the presence of low-molecular weight B-cell growth factor (LMW-BCGF). Expression of virus envelope glycoprotein (gp) 120 could also be detected on a subpopulation of B cells (CD19+, CD22+) by flow cytometry. Blocking experiments with monoclonal antibodies (MoAbs) against CD4, CD21 (complement receptor 2 [CR2]), CD35 (CR1), CD19, and CD5 surface molecules indicated that infection of B cells involves CD4, CD21, and CD35 antigens. Indeed, blocking of CD4 receptor inhibited 10% of p24 production, and blocking of both CD21 and CD35 led to extinction of p24 signal. CR-dependent pathway is thus a major route for C'-ADE of HIV infection in normal B cells. Our results emphasize the importance of studying interactions between HIV and the complement system for better understanding infection mechanisms and the major dysfunctions of B cells in HIV-infected individuals.