bluuebunny/crossref_metadata_2025 huggingface dataset:
Fibroblast tissue factor: calcium and ionophore induce shape changes, release of membrane vesicles, and redistribution of tissue factor antigen in addition to increased procoagulant activity
Authors: Carson SD , Perry GA , Pirruccello SJ
Published: October 2019

The coagulant activity of tissue factor (TF) in the membranes of cultured cells is increased after physical disruption of the cells, and a similar increase can be elicited by treatment of cell cultures with calcium ionophore and calcium. We observed that the supernatants of cultures treated with calcium and ionophore 4-Br-A23187 contained more TF activity than those of control cultures. Phase contrast microscopy showed that cultures treated with ionophore and calcium contained rounded cells, membrane vesicles, and cell fragments. Laser-activated fluorescence microscopy of cells stained for tissue factor antigen showed that 4-Br-A23187, in the presence of 5 mmol/L calcium, caused progressive changes in cell morphology. Treatment of cultures with thrombin receptor agonist peptide caused a transient increase in cytoplasmic calcium, but had no short-term effect on TF activity or cell morphology. These combined results show that 4-Br-A23187, with extracellular calcium, increases TF activity concomitant with dramatic changes in cell morphology and the plasma membrane. The effect of increased cytoplasmic calcium on TF expression may therefore be similar in mechanism to other models of cell injury and may be caused by the effects of a sustained increase of cytosolic calcium on cellular elements that influence membrane stability and the distribution of TF per se.
Characterization of clone-specific rearrangement T-cell receptor gamma- chain genes in lymphomas and leukemias by the polymerase chain reaction and DNA sequencing
Authors: Kneba M , Bolz I , Linke B , Bertram J , Rothaupt D , Hiddemann W
Published: October 2019

The structures of rearranged gamma-chain T-cell antigen receptor (TCR) genes were analyzed in 5 cases of T-cell acute lymphoblastic leukemia (T-ALL), in 15 cases of peripheral T-cell non-Hodgkin's lymphoma (T- NHL), in 1 case with large granular CD8 lymphocytosis, 1 case with CD8 lymphocytosis after autologous bone marrow transplantation for Hodgkin's disease, and in 2 cases with nonneoplastic diseases. Rearranged V-J TCR gamma-gene segments were amplified by the polymerase chain reaction (PCR). Because most of the biopsy tissue or bone marrow samples contained significant amounts of admixed nonmalignant T-cells, direct DNA sequencing of the PCR products yielded mixed sequence data because of coamplification of clonal together with polyclonal TCR gamma V-N-J junctions. Reliable data could only be obtained by cloning the V gamma-J gamma PCR products and sequencing several (4 to 10) randomly chosen clones. In the polyclonal samples, all PCR-derived clones differed in their specific V-N-J junctions, as expected. In the two T- cell lines and in most of the T-cell malignancies, monoclonal PCR products could be identified by the demonstration of clonally restricted V-N-J junctions. In most cases, this information yielded the desired clone-specific sequence and showed a background population of polyclonal TCR gamma cells in each specimen, except for those that were obtained from the T-ALL samples, the cell lines, or the NHL samples with high tumor cell fraction. The results obtained by PCR-directed sequencing were confirmed by temperature-gradient gel electrophoresis (TGGE) that showed distinct DNA bands only with the PCR products containing predominant (ie, monoclonal) TCR gamma V-N-J junctions. By combined sequence and TGGE analysis, it was found that PCR/TGGE is able to distinguish between monoclonal and polyclonal TCR gamma-PCR products. This finding prompted us to complete the analysis of the TCR gamma locus in the samples by PCR/TGGE using primer mixes which covered all possible V gamma and J gamma recombinations. Monoclonality was shown with all mixes by PCR/TGGE in 21 of 24 (87%) of the lymphoproliferations. In summary, the present study shows that the combination of amplifying TCR gamma V-N-J junctions by PCR with the identification of clonal PCR products by TGGE and DNA sequencing is a reliable method for the characterization of clonal TCR gamma sequences.
Defective assembly of membrane proteins in erythroid precursors of beta- thalassemic mice
Authors: Yuan J , Rubin E , Aljurf M , Ma L , Schrier SL
Published: October 2019

beta-Thalassemic mice provide a useful model for studying the pathophysiology of human beta-thalassemia in that one can perform experiments that are difficult to perform in humans. The ease of access to beta-thalassemic mouse marrow provided the opportunity to explore the cause of the ineffective erythropoiesis that characterizes severe beta-thalassemia in mouse and man. We hypothesized that the accumulation of excess alpha-globin might interfere with the normal assembly of red blood cell (RBC) membrane proteins, thus contributing to the severe intramedullary lysis. Femoral marrow was obtained from normal and beta-thalassemic mice, and RBC precursors were purified (> 90%) by panning and harvesting CD45- cells. The assembly of RBC membrane proteins was assessed by observing immunofluorescence patterns obtained on fixed permeabilized precursors using rabbit polyclonal antibodies directed against human spectrin, and band 4.1, and murine band 3. The distribution of the proteins was shown with a fluorescein- tagged goat antirabbit antibody. In contrast to normal mice, about 30% of intermediate and late stage erythroblasts in beta-thalassemic mice appear abnormal. Neither spectrin nor band 4.1 formed crisp rim fluorescence in these erythroid precursors of thalassemic mice, whereas assembly of band 3 appeared normal. Therefore, the assembly of membrane skeletal proteins is abnormal in murine beta-thalassemic erythroid precursors perhaps because of the deposition of unmatched alpha-globin chains.
Erythrocyte membrane proteins reactive with IgG (warm-reacting) anti- red blood cell autoantibodies: II. Antibodies coprecipitating band 3 and glycophorin A
Authors: Leddy JP , Wilkinson SL , Kissel GE , Passador ST , Falany JL , Rosenfeld SI
Published: October 2019

In our initial immunochemical study of the red blood cell (RBC) membrane proteins targeted in 20 cases of warm-antibody autoimmune hemolytic anemia (AHA), RBC eluates of 6 patients mediated immunoprecipitation (IP) of both band 3 and glycophorin A (GPA). This dual IP pattern had previously been observed with murine monoclonal antibodies (MoAbs) against the high frequency blood group antigen, Wrb (Wright), suggesting that the Wrb epitope may depend on a band 3-GPA interaction. Earlier, anti-Wrb had been identified serologically as a prominent non-Rh specificity of AHA autoantibodies. In the present study, 6 autoantibody eluates immunoprecipitating band 3 and GPA from common Wr(b+) RBCs were retested, in parallel with murine anti-Wrb MoAbs, against very rare Wr(a+b-)En(a+)RBCs. One patient's autoantibodies were unreactive with the Wr(b-) RBCs by either IP or indirect antiglobulin test (IAT) and were judged to have “pure” anti- Wrb specificity. Two other patients' autoantibodies displayed both IP and serologic evidence for anti-Wrb as a major component in combination with one or more additional specificities. However, among 3 other patients whose autoantibodies coprecipitated band 3 and GPA, there was no reduction in IP or IAT reactivity with Wr(b-) RBCs in 2 and only slight reduction in the third. We conclude (1) that human anti-Wrb autoantibodies, like their murine monoclonal counterparts, coprecipitate band 3 and GPA from human RBCs; but (2) that not all antibodies with this IP behavior have anti-Wrb serologic specificity, as defined by this donor's Wr(b-) RBCs. The possibility of an additional (non-Wrb) RBC epitope dependent on a band 3-GPA interaction is raised.
Characterization of murine CD34, a marker for hematopoietic progenitor and stem cells
Authors: Krause DS , Ito T , Fackler MJ , Smith OM , Collector MI , Sharkis SJ , May WS
Published: October 2019

CD34 is expressed on human hematopoietic stem and progenitor cells, and its clinical usefulness for the purification of stem cells has been well established. However, a similar pattern of expression for murine CD34 (mCD34) has not yet been determined. Two polyclonal anti-mCD34 antibodies that specifically recognize both endogenous and recombinant murine CD34 were developed to characterize the mCD34 protein and to determine its pattern of expression on murine cell lines and hematopoietic progenitor cells. Fluorescence-activated cell sorter analysis showed that mCD34 is expressed on NIH/3T3 embryonic fibroblasts, PA6 stromal cells, embryonic stem cells, M1 leukemia cells, and a subpopulation of normal bone marrow cells. Murine CD34 was found to be a glycoprotein expressed on the cell surface as either a full-length (approximately 100 kD) or truncated (approximately 90 kD) protein in NIH/3T3 and PA6 cells. Recombinant full-length CD34, when expressed in the CHO-K1 cell line, had a molecular weight of approximately 105 kD. Full-length CD34 expressed on M1 leukemia cells, had a higher apparent molecular weight (110 kD). These results suggest that there are glycosylation differences between CD34 expressed by different cell types. The full-length form, but not the truncated form, is a phosphoprotein that is hyperphosphorylated in response to 12–0- Tetradecanoyl phorbol 13-acetate treatment, suggesting potential functional differences between the two forms. Selection of the 3% highest-expressing CD34+ bone marrow cells enriched for the hematopoietic precursors that form colony-forming unit-spleen (CFU-S), CFU-granulocyte-macrophage, and burst-forming unit-erythroid. Transplantation of lethally irradiated mice with these cells demonstrated both short- and long-term repopulating ability, indicating that this population contains both functional hematopoietic progenitors and the putative stem cell. These antibodies should be useful to select for murine hematopoietic stem cells.
Autografting with cultured marrow in chronic myeloid leukemia: results of a pilot study [see comments]
Authors: Barnett MJ , Eaves CJ , Phillips GL , Gascoyne RD , Hogge DE , Horsman DE , Humphries RK , Klingemann HG , Lansdorp PM , Nantel SH
Published: October 2019

Incubation of chronic myeloid leukemia (CML) marrow for 10 days in vitro causes a marked and selective loss of very primitive Philadelphia chromosome (Ph)+ as compared with Ph- progenitors. We have autografted 22 patients with CML (16 in first chronic phase [group 1] and 6 with more advanced disease [group 2]) with marrow treated in this way to facilitate restoration of Ph- hematopoiesis after intensive therapy. Hematologic recovery to greater than 0.5 x 10(9)/L neutrophils occurred in 16 patients, and to greater than 20 x 10(9)/L platelets in 15 of 21 evaluable patients at a median of 29 and 48 days postautograft, respectively. Regenerating marrow cells were 100% Ph- in 13 patients and 75% to 94% Ph- in 3. Between 4 and 36 months (median 12) postautograft, Ph+ cells became detectable in all but 1 (who died in remission) of the 13 patients who achieved complete cytogenetic remission. Four of 7 evaluable patients treated with low-dose interferon alpha were returned to complete cytogenetic remission. Thirteen group 1 patients (81%) are alive 1.0 to 5.7 years (median 2.6) after autografting: 4 in complete cytogenetic remission, 2 in hematologic remission, 6 in chronic phase, and 1 in myeloid blast phase. Three group 2 patients (50%) are alive at 2.6, 3.8, and 4.3 years after autografting: 1 in partial cytogenetic remission, 1 in chronic phase, and 1 in accelerated phase. Thus, autografts of cultured marrow can result in prolonged restoration of Ph- hematopoiesis for some patients with CML.
Mac-1 (CD11b/CD18) and CD45 mediate the adhesion of hematopoietic progenitor cells to stromal cell elements via recognition of stromal heparan sulfate
Authors: Coombe DR , Watt SM , Parish CR
Published: October 2019

Hematopoiesis is regulated by two sets of signals, those generated by cytokines and those generated when precursor cells interact with bone marrow (BM) stroma. The intimate contact between precursors and stroma appears to be mediated by multiple, different receptor-ligand binding events. To identify receptor-ligand pairs mediating the adhesion of hematopoietic precursor cells to stroma, an in vitro model of hematopoiesis was used. This involved coculturing the BM-derived, interleukin-3 (IL-3)-dependent, multipotential cells, FCDP-mix A4 (A4) with a stromal equivalent embryonic mesenchymal cell line, Swiss 3T3 (3T3). In coculture, A4 cells survive, proliferate, and differentiate in the absence of exogenous IL-3, providing they are attached to the 3T3 cell surface. By using detergent lysates of surface-biotinylated A4 cells, A4 cell molecules that bind to the stroma could be detected by either fluorescein isothiocyanate (FITC)-streptavidin or FITC-antibody staining and flow cytometry. Using this approach the beta 2 integrin, Mac-1, and CD45, a receptor-type tyrosine phosphatase, were identified as molecules on the A4 cell surface that bind 3T3 cells. Various glycosaminoglycans (GAGs), particularly heparin and heparan sulfate, blocked binding of A4 cell surface molecules to the 3T3 cells. The binding of CD45 and Mac-1 to the 3T3 cells was similarly blocked by these GAGs. Removal of heparin-binding molecules from A4 cell lysates diminished binding to the 3T3 cells and digestion of the 3T3 cell surface with heparinase abolished the binding of CD45 and Mac-1. The data suggest that heparan sulfate on the 3T3 cell surface is a ligand for both CD45 and Mac-1, but the two molecules recognize different heparan sulfate structural motifs.
Abnormal response to granulocyte colony-stimulating factor (G-CSF) in canine cyclic hematopoiesis is not caused by altered G-CSF receptor expression
Authors: Avalos BR , Broudy VC , Ceselski SK , Druker BJ , Griffin JD , Hammond WP
Published: October 2019

A decrease in responsiveness to granulocyte colony-stimulating factor (G-CSF) has been implicated in the pathophysiology of cyclic hematopoiesis. Using the canine model of cyclic neutropenia, we examined the response of neutrophil precursors to G-CSF in vitro and G- CSF receptor expression in neutrophils from grey collie dogs to determine whether the abnormal response observed to G-CSF in vivo in this disorder is present at the level of the progenitor cell and is caused by defective G-CSF receptor expression. Bone marrow mononuclear cells from grey collie dogs required sevenfold higher G-CSF concentrations than normal dog cells to achieve half-maximal colony growth [56 pmol/L v 8 pmol/L). Receptor binding assays with 125I- labeled G-CSF and Scatchard analyses of the equilibrium binding data were consistent with expression of a single class of high-affinity receptors for G-CSF on neutrophils from both normal dogs and grey collies with similar receptor numbers (56 to 446 sites/cell v 78 to 199 sites/cell) and binding affinities (28 to 206 pmol/L v 84 to 195 pmol/L). Chemical cross-linking studies identified a G-CSF binding protein of approximately 120 kD on neutrophils from grey collies, similar in size to that on normal dog neutrophils. No abnormal G-CSF receptor mRNA transcripts were detected in neutrophils from grey collie dogs by Northern blot analysis. Treatment of both normal and grey collie neutrophils with G-CSF rapidly induced tyrosine phosphorylation of an 80-kD protein that behaved like canine c-rel. These results demonstrate that the abnormal responsiveness to G-CSF in canine cyclic hematopoiesis is present in neutrophil precursors and is not associated with demonstrable alterations in the number, binding affinity, or overall size of the G-CSF receptor in neutrophils, or with defective tyrosine phosphorylation of p80. These data suggest that cyclic hematopoiesis is caused by a defect in the G-CSF signal transduction pathway at a point distal to G-CSF receptor binding that does not involve the early biochemical events leading to p80 tyrosine phosphorylation.
Cell surface expression of c-kit receptors by childhood acute myeloid leukemia blasts is not of prognostic value: a report from the Childrens Cancer Group
Authors: Smith FO , Broudy VC , Zsebo KM , Lampkin BC , Buckley CV , Buckley JD , Opie T , Woods WG , Hammond GD , Bernstein ID
Published: October 2019

The prognostic significance of c-kit receptor expression on leukemic blast cells was determined in 122 children with acute myeloid leukemia (AML) entered onto Childrens Cancer Group protocol 213. Clinical and laboratory characteristics as well as outcome were analyzed according to the percentage of blast cells expressing c-kit receptors and the relative number of c-kit receptors per cell as determined by indirect immunofluorescence. c-kit receptor expression was strongly associated with the expression of the CD34 antigen. However, contrary to findings in adult patients with AML, c-kit receptor expression by childhood AML blast cells was not predictive of a poor response to therapy.
Phenotypic and functional characterization of T-BAM (CD40 ligand)+ T- cell non-Hodgkin's lymphoma
Authors: Inghirami G , Lederman S , Yellin MJ , Chadburn A , Chess L , Knowles DM
Published: October 2019

The precise mechanisms regulating T-helper function have been intensively investigated. We and others have recently identified a new T-cell-B-cell-activating molecule called T-BAM that directs B-cell differentiation by interacting with the CD40 molecule on B cells. Using a specific monoclonal antibody against T-BAM (5C8), we have previously shown that T-BAM expressing T cells are predominantly CD4+CD8- and in normal lymphoid tissue have a unique distribution. However, no information has been obtained regarding the phenotype and functional properties of human neoplastic T cells. Therefore, we investigated T- BAM expression immunohistochemically in 87 well-characterized T-cell non-Hodgkin's lymphomas and lymphoid leukemias (LL). We found that 21/81 neoplasms expressed detectable T-BAM and these positive tumors belong almost exclusively to the CD4+CD8- subtype. In addition, to determine whether T-BAM expression could be induced on T-BAM-LL cells, we activated T-BAM-LLs in vitro and showed that T-BAM could be upregulated only in CD4+CD8- tumors. Our studies clearly show that T- BAM is constitutively expressed in a large number of T-cell neoplasms with a relative mature phenotype (CD4+CD8-) and that only CD4+ neoplastic T cells can be induced in vitro to express this molecule. Additional studies are necessary to identify the biologic significance of T-BAM expression and its potential and clinical implications.
Hairy cell interactions with extracellular matrix: expression of specific integrin receptors and their role in the cell's response to specific adhesive proteins
Authors: Burthem J , Baker PK , Hunt JA , Cawley JC
Published: October 2019

Integrin/extracellular-matrix interactions are central to the migration, localization, and subsequent function of lymphocytes within tissues. In hairy cell leukemia (HCL) the malignant cells display a highly characteristic tissue distribution in which interactions with extracellular matrix (ECM) are often prominent. Therefore, we used HCL as a model in which to investigate the poorly understood integrin/ECM interactions that underlie the migratory behavior of malignant B lymphocytes. Using a combined approach involving immunocytochemistry, flow cytometry, and immunoprecipitation analysis, hairy cells (HCs) were shown to have a consistent and distinctive phenotype (mainly alpha 4 beta 1, alpha 5 beta 1, alpha v beta 1, and alpha v beta 3). Furthermore, functional studies utilising adhesion assays, time-lapse video-microscopy and image analysis showed that the HCs displayed very specific adhesive behaviour in response to relevant adhesive protein ligands. HCs were able to adhere to different extents on all the adhesive proteins examined, but, on laminin and collagen, binding was weak with little cytoplasmic spreading. In contrast, the cells showed strong adhesion both to fibronectin (FN) and to vitronectin (VN). On FN, the cells spread extensively with nonpolarized cytoplasmic projections, whereas on VN cytoplasmic projections were markedly polarized. This polarized morphology was shown to reflect cell motility. Investigation of the role of individual integrin receptors in the cell movement response suggested that alpha v beta 3 is the major integrin responsible for this motile behavior. These results are discussed in relation to the limited previous data on leukemic and activated B-cell integrins, and we suggest that the HC integrins play a significant role in the characteristic behavior of HCs within tissues.
Transfusion-transmitted human T-cell lymphotropic virus type I infection in Taiwan: a true risk and occasional coinfection with hepatitis C virus shown in a prospective study
Authors: Wang JT , Lin MT , Chen PJ , Sheu JC , Lin JT , Wang TH , Chen DS
Published: October 2019

To study the incidence of human T-cell lymphotropic virus (HTLV) after blood transfusion in Taiwan, serum samples from 699 patients in a prospective study were examined for seroreactivity of anti-HTLV. By an enzyme immunoassay, 9 of the 699 recipients were repeatedly positive. Serial serum samples of these 9 patients were then confirmed with a Western blot analysis and with a polymerase chain reaction (PCR) assay for HTLV-I genome. Four were already positive for anti-HTLV before transfusion, 1 carried antibodies to HTLV-I transiently after transfusion, and only 4 cases had de nova seroconversions. These patients and their family members were called back and tested for HTLV- I genome in the peripheral blood mononuclear cell (PBMC) and plasma. All the serologically positive patients, except the “transient one,” were positive for HTLV sequences in the PBMCs. Viral sequences could also be detected in several serum or plasma samples. In the family members, only the spouse of a pretransfusion-positive patient was infected. These results suggested that approximately 0.6% of the blood recipients were infected by HTLV-I through transfusion in Taiwan, and that the frequency of intrafamilial HTLV-I transmission is low. We also observed the unusual coinfection by both HTLV-I and hepatitis C virus in 2 patients, and superinfection of hepatitis C virus after blood transfusion in 1 HTLV-I carrier. Cases of coinfection suggest a prevalence of both viruses in blood donors and warrant further screening.
Increased levels of circulating Epstein-Barr virus (EBV)-infected lymphocytes and decreased EBV nuclear antigen antibody responses are associated with the development of posttransplant lymphoproliferative disease in solid-organ transplant recipients
Authors: Riddler SA , Breinig MC , McKnight JL
Published: October 2019

Epstein-Barr virus (EBV)-associated posttransplant lymphoproliferative disease (PTLD) is an uncommon but potentially fatal complication of immunosuppression in solid-organ transplant recipients. A semiquantitative DNA polymerase chain reaction assay was developed to amplify a unique 269-bp region of the EBNA-1 gene in peripheral blood lymphocytes (PBL) using the primers described by Telenti et al (J Clin Microbiol 28:2187, 1990). Serial samples were studied from 23 transplant recipients, 12 of whom were diagnosed with PTLD. The majority of transplant recipients who were EBV seropositive at the time of transplant surgery and who did not develop PTLD (5 of 7, 71%) exhibited less than a 10-fold increase in the levels of EBV-infected PBL over the 0.1 to 5 EBV genomes/10(6) PBL observed in immunocompetent EBV seropositive controls. Transplant recipients who were seronegative at the time of transplantation and who underwent a primary EBV infection but did not develop PTLD exhibited a reduced capacity to control viremia because the levels of EBV-infected PBL were up to 400 times greater than the 1.0 to 50 EBV genomes/10(6) PBL observed in individuals undergoing acute infectious mononucleosis (Rocci et al: N Engl J Med 296:132, 1977). However, all transplant recipients who developed PTLD exhibited a marked elevation of EBV-infected PBL independent of their serologic state at the time of transplantation. Six of the 10 transplant recipients with PTLD exhibited > or = 300,000 EBV genomes/10(5) PBL, two exhibited 10,000 to 50,000 EBV-infected genomes/10(5) PBL, and one each exhibited 2,500 and 500 EBV genomes/10(5) PBL. However, the latter two samples were obtained 4 to 5 weeks after the diagnosis of PTLD and may reflect a decrease in viral load resulting from immunomodulation. Marked decreases in the levels of EBV nuclear antigen-1 (EBNA-1), EBNA-2, and EBNA-LP antibodies correlated with the increase in EBV-infected PBL. Hence, a quantitative difference in circulating EBV viral load and EBNA antibody levels is evident between transplant recipients with and without PTLD and may be useful as a noninvasive prognostic marker with which to monitor and/or predict the development of PTLD.
Increasing hepatitis C virus RNA levels in hemophiliacs: relationship to human immunodeficiency virus infection and liver disease. Multicenter Hemophilia Cohort Study
Authors: Eyster ME , Fried MW , Di Bisceglie AM , Goedert JJ
Published: October 2019

We have previously observed an increased frequency of liver failure in human immunodeficiency virus (HIV)-infected hemophiliacs. The purpose of this study was to quantitate hepatitis C virus (HCV) RNA levels in serial samples from HIV-seropositive (HIV+) and HIV-seronegative (HIV-) hemophiliacs before and after HIV seroconversion, and to examine the relationship of HCV RNA levels to CD4 cell counts and to hepatic dysfunction over time. HCV RNA levels were measured on serial samples of serum stored frozen from 17 HCV+/HIV+ and 17 HCV+/HIV- subjects matched within 5 years of their birth dates. All were HCV+ before study entry. HCV RNA levels were quantitated by a branched DNA-enhanced label amplification (bDNA) assay. For samples less than the cut off, HCV RNA was measured by the nested polymerase chain reaction. Individual changes over time, clinical groups, and mean values within predetermined time windows were compared with Wilcoxon rank sum tests. Mean HCV RNA levels increased from 2.76 (standard error [SE] 1.33) x 10(5) to 2.84 (SE 1.39) x 10(6) eq/mL during the first 2 years after HIV seroconversion (P = .006). Baseline HCV RNA levels in the pre-HIV seroconversion group were not significantly different from the baseline levels in those who remained HIV (P = .79). Over the entire period of study, HCV RNA levels increased nearly threefold in those who remained HIV- (mean 9.47 [SE 4.78] x 10(5) to 2.81 [SE 1.13] x 10(6)/mL; P = .02). Among those who became HIV+, HCV RNA levels increased 58-fold (mean 2.85 [SE 1.26] x 10(5) to 1.66 [SE 0.57] x 10(7) eq/mL; P = .0001). The rate of increase in HCV RNA levels was eightfold faster for HIV+ subjects than for subjects who remained HIV- (P = .009). HCV RNA levels increased twofold higher in 5 subjects who developed liver failure compared with the 12 who did not (P = .43). HCV RNA levels correlated significantly with CD4 counts (R = -.33, P = .01) and serum aspartate aminotransferase levels (AST) (R = .36, P = .007). We conclude that HCV RNA levels are significantly higher in HIV+ than in HIV- multitransfused hemophiliacs. HCV load increases over time, is enhanced by HIV, and further increases as immune deficiency progresses. HCV RNA levels are directly associated with high AST levels. These findings suggest that HIV-induced immune deficiency may promote increased HCV replication.
Prediction of response to erythropoietin treatment in chronic anemia of cancer [see comments]
Authors: Ludwig H , Fritz E , Leitgeb C , Pecherstorfer M , Samonigg H , Schuster J
Published: October 2019

Chronic anemia of cancer can be corrected in approximately 50% of the cases by treatment with recombinant human erythropoietin (rHuEPO). Early prediction of responsiveness would avoid the emotional and financial burden of ineffective medical intervention. Eighty patients with chronic anemia of cancer undergoing treatment with rHuEPO (150 U/kg, 3 times per week by subcutaneous injection; after 6 weeks without response, 300 U/kg) participated in this study. Response was defined as a gain of at least 2 g/dL hemoglobin (Hb) within 12 weeks. Multivariate discriminant analysis and logistic regression analysis of response were performed on routine blood tests; serum levels of EPO, iron, ferritin, transferrin, and its receptor; World Health Organization (WHO) performance status; various cytokines; neopterin; stem cell factor; C- reactive protein; and alpha 1-antitrypsin. At baseline, none of these factors showed sufficient prognostic power. The following predictive algorithm was developed: (1) If after 2 weeks of therapy both the serum EPO level is > or = 100 mU/mL and Hb concentration has not increased by at least 0.5 g/dL, unresponsiveness of the patient is very likely (predictive power, 93%); otherwise, response may be predicted with an accuracy of 80%. (2) If both the serum level of EPO is less than 100 mU/mL and Hb concentration has increased by > or = 0.5 g/dL, response is highly probable (predictive power, 95%). (3) Alternatively, a serum ferritin level of > or = 400 ng/mL after 2 weeks of rHuEPO therapy strongly indicates unresponsiveness (predictive power, 88%), whereas a level less than 400 ng/mL suggests response in 3 of 4 patients.
Growth and differentiation of the human megakaryoblastic cell line (ELF- 153): a model for early stages of megakaryocytopoiesis
Authors: Mouthon MA , Freund M , Titeux M , Katz A , Guichard J , Breton-Gorius J , Vainchenker W
Published: October 2019

ELF-153 is a cell line that has been established from a patient with a poorly differentiated acute myeloid leukemia associated with an acute myelofibrosis. A majority of cells had a blast morphology with the phenotype of a myeloid hematopoietic progenitor, ie, CD34+, CD33+, CD13+, HLA-DR+, but CD38-, and the remaining cells (5% to 10%) expressed platelet restricted proteins such as CD41, CD42, CD36, CD61, and von Willebrand factor; some of them were polyploid (up to 32N) and exhibited demarcation membranes and alpha granules. No erythroid or other lineage-specific markers were detected. Proliferation of ELF-153 cells was highly stimulated by interleukin-3 (IL-3) and granulocyte- macrophage colony-stimulating factor and to a lesser extent by stem cell factor and IL-6. In contrast, the cell line did not respond to erythropoietin, leukemia inhibitory factor, IL-7, IL-11, granulocyte colony-stimulating factor, and basic fibroblast growth factor. ELF-153 cells could be separated by flow cytometry into three discrete cell populations (CD34+/CD61-, CD34+/CD61+, and CD34-/CD61+) with different proliferative and endomitotic properties corresponding to distinct stages of the mega karyocyte (MK) differentiation. This MK differentiation, which involved a minority of ELF-153, could be increased in the presence of 5-azacytidine and phorbol ester, but could not be significantly modified by growth factors. By contrast, cytochalasin B dramatically induced polyploidization without differentiation. It is noteworthy that association of 5-azacytidine to cytochalasin B dramatically induced the production of polyploid MK cells. To understand the molecular mechanisms underlying this MK differentiation, the expression of GATA-1 and GATA-2 was investigated in subpopulations of ELF-153. A high level of GATA-1 and GATA-2 mRNA was only present in the CD61+ cells. Therefore, these two transactivating factors may play an important role in the MK differentiation of ELF-153. We conclude that ELF-153 might be an important tool to investigate the mechanisms by which transcription factors control differentiation of MK progenitors.
Activation of the fibrinogen binding site on platelets isolated from a patient with the Strasbourg I variant of Glanzmann's thrombasthenia
Authors: Kouns WC , Steiner B , Kunicki TJ , Moog S , Jutzi J , Jennings LK , Cazenave JP , Lanza F
Published: October 2019

One proposed ligand binding site on platelet integrin alpha IIb beta 3 is the region of the beta 3 subunit encompassing amino acids 211–221. However, we recently showed that synthetic peptides corresponding to amino acids 211–221 inhibit fibrinogen binding to alpha IIb beta 3 by binding to alpha IIb beta 3 and not to fibrinogen. In this study, we show that AP6, a monoclonal antibody (MoAb) directed against amino acids 214–221 of beta 3, bound to immobilized active alpha IIb beta 3 but did not inhibit fibrinogen binding to the complex. We then determined whether nonfunctional alpha IIb beta 3 on platelets with a beta 3 Arg-214-->Trp mutation (Strasbourg I variant of Glanzmann's thrombasthenia or GTV) could be induced to aggregate after treatment with dithiothreitol (DTT). DTT has been shown to expose the fibrinogen receptor on normal platelets. DTT treatment of GTV platelets did result in the formation of the fibrinogen binding site as indicated by the binding of pI-55, an MoAb that only binds to the activated form of alpha IIb beta 3. Furthermore, DTT-treated GTV platelets aggregated in the presence of fibrinogen and divalent cations. This aggregation was inhibited by EDTA, RGDS, and the selective alpha IIb beta 3 antagonist, Ro 43–5054. These data show that Arg-214 of beta 3 is not required for fibrinogen binding or for platelet aggregation. However, this amino acid appears to be critical for the formation and for the maintenance of the correct tertiary structure of the fibrinogen binding site on alpha IIb beta 3.
Activated factor X and thrombin formation triggered by tissue factor on endothelial cell matrix in a flow model: effect of the tissue factor pathway inhibitor
Authors: van 't Veer C , Hackeng TM , Delahaye C , Sixma JJ , Bouma BN
Published: October 2019

The procoagulant subcellular matrix of stimulated endothelial cells that contains tissue factor (TF) was used to investigate the mechanism by which TF pathway inhibitor (TFPI) inhibits thrombin formation initiated by TF/factor VIIa (FVIIa) under flow conditions. Purified coagulation factors VII, X, and V and prothrombin were perfused at a wall shear rate of 100 s-1 through a flow chamber containing a coverslip covered with matrix of cultured human umbilical vein endothelial cells. This resulted in a TF- and FVII-dependent FXa and thrombin generation as measured in the effluent at the outlet of the system. Inhibition of this TF/FVIIa-triggered thrombin formation by TFPI purified from plasma was dependent on the amount of TF present on the endothelial cell matrix. The rate of prothrombinase assembly and steady-state levels of thrombin formation were decreased by TFPI. Because persistent albeit decreased steady-state levels of thrombin formation occurred in the presence of TFPI, we conclude that plasma- TFPI does not inhibit FXa present in the prothrombinase complex. The addition of FIX and FVIII to perfusates containing FVII and FX increased the FXa generation on endothelial matrices, and counteracted the inhibition of thrombin formation on endothelial cell matrices by TFPI. Our data provide further evidence for the hypothesis that the rapid inactivation of TF/FVIIa by TFPI in combination with the absence of either FVIII or FIX causes the bleeding tendency of patients with hemophilia A or B.
Plasmic degradation of fibrin rapidly decreases platelet adhesion and spreading
Authors: Hamaguchi M , Bunce LA , Sporn LA , Francis CW
Published: October 2019

Plasmin cleaves fibrin at or near sites involved in platelet recognition and may modulate platelet adhesion and spreading. Using an in vitro system, we have characterized the effects of limited plasmic degradation of polymerized fibrin on platelet adhesion and spreading. As shown by scanning electron microscopy, exposure to plasmin changed the tight fibrillar fibrin surface to a less dense structure with irregular and broken fibers. There was a gradient of proteolytic degradation through the fibrin clot as shown by sodium dodecyl sulfate polyacrylamide gel electrophoresis with the most extensive degradation at the surface. Plasmic degradation resulted in a rapid and progressive decrease in platelet adhesion. Plasmin exposure for 5 minutes resulted in only 6% solubilization of the fibrin but a 56% decrease in platelet adhesion. After 30 minutes of plasmin exposure, spreading of adherent platelets on fibrin also decreased sharply to a minimum of 35% of baseline. Inhibition experiments with specific monoclonal antibodies (MoAbs) indicated that platelet adhesion to undergraded fibrin involved residues within the sequence 566 through 580 of the alpha chain (including the RGDS site), the carboxyl terminal dodecapeptide of the gamma chain, and the amino terminus of the beta chain. MoAb 7E3, reactive with alpha IIb beta 3, inhibited platelet adhesion to fibrinogen by 90% +/- 5%, and to desA fibrin, prepared with Reptilase (American Diagnostica, Greenwich, CT), by 94% +/- 6%, whereas inhibition of adhesion to undegraded desAB fibrin was significantly less (48% +/- 8%, P > .01). The addition of 7E3 to MoAb T2G1, reactive with beta 15–21, significantly increased inhibition to desAB fibrin to 69% +/- 6% (P < .025), suggesting that the newly exposed amino terminus of the beta chain contributes to platelet adhesion. The results show that plasmin exposure of fibrin markedly decreases platelet adhesion and spreading, suggesting that plasmin degradation may play a role in modulating cellular responses to fibrin.
A variant chromosome translocation at 11q13 identifying PRAD1/cyclin D1 as the BCL-1 gene
Authors: Komatsu H , Iida S , Yamamoto K , Mikuni C , Nitta M , Takahashi T , Ueda R , Seto M
Published: October 2019

The 11q13 breakpoint region of t(11;14) (q13;q32), translocated to the Ig heavy chain locus at 14q32, has been designated as BCL-1 for B-cell leukemia/lymphoma-1, but the nature of the transcriptional unit has long remained unclear. Recently, the PRAD1 gene encoding cyclin D1, isolated from the 11q13 region, was proposed as a candidate BCL-1 gene on the basis of chromosome walking and concordant overexpression of PRAD1 mRNA in cell lines with t(11;14)(q13;q32). We report here molecular analysis of a variant translocation at the BCL-1 locus, t(11;22)(q13;q11), showing juxtaposition of the Ig light chain gene, Ig lambda, to the PRAD1 gene at its 3′ end, resulting in overexpression of PRAD1 mRNA. Because only the PRAD1 gene is present between the Ig heavy chain and light chain gene breakpoints, an identity between BCL-1 and the PRAD1/cyclin D1 gene is strongly indicated.
Molecular basis of reduced or absent expression of decay-accelerating factor in Cromer blood group phenotypes
Authors: Lublin DM , Mallinson G , Poole J , Reid ME , Thompson ES , Ferdman BR , Telen MJ , Anstee DJ , Tanner MJ
Published: October 2019

The human erythrocyte blood group system Cromer consists of high- incidence and low-incidence antigens that reside on decay-accelerating factor (DAF; CD55), a glycosyl-phosphatidylinositol-anchored membrane protein that regulates complement activation on cell surfaces. In the Cromer phenotypes Dr(a-) and Inab there is reduced or absent expression of DAF, respectively. This study investigated the molecular basis of the reduced DAF expression by polymerase chain reaction amplification of genomic DNA and RNA/cDNA obtained from Epstein-Barr virus- transformed lymphoblastoid cell lines. Sequence analysis of the Inab propositus showed a single nucleotide substitution in exon 2 of the DAF gene and at the corresponding position in the cDNA, G314-->A resulting in Trp53-->Stop. This truncation near the amino terminus explains the complete absence of surface DAF in the Inab phenotype. A similar analysis was performed for two Dr(a-) individuals, including KZ, who was previously reported to be Inab phenotype but is now shown by immunochemical and serologic methods to be Dr(a-) phenotype. A single nucleotide change was found in exon 5 of the DAF gene, C649-->T resulting in Ser165-->Leu, which we had previously shown to lead to loss of the Dra epitope. However, two species of cDNA were found, one encoding full-length DAF with the single amino acid change and the more abundant species having a 44-nucleotide deletion. The 44 nucleotide deletion includes the single polymorphic site, which creates a cryptic branch point in the Dr(a-) allele that leads to use of a downstream cryptic acceptor splice site. This shifts the reading frame and leads to a premature stop codon that precludes membrane anchoring. Thus, the single point mutation in the Dr(a-) phenotype results in a novel use of alternative splicing and provides a molecular explanation for both the antigenicity and the reduced DAF expression seen in this phenotype.
Abnormal phospholipid metabolism in spur cell anemia: decreased fatty acid incorporation into phosphatidylethanolamine and increased incorporation into acylcarnitine in spur cell anemia erythrocytes
Authors: Allen DW , Manning N
Published: October 2019

Spur cell anemia is a hemolytic anemia seen in severe alcoholic cirrhosis that is characterized by unusual morphology and a decreased ratio of phospholipids to cholesterol in the erythrocyte membrane. We hypothesized that defective phospholipid repair may contribute to the red blood cell (RBC) phospholipid abnormalities of spur cell anemia. Therefore, we compared RBCs from normal control subjects with RBCs from spur cell anemia patients. The incorporation of [14C] arachidonic acid into the phospholipids and acylcarnitine (acyl-Cn) of spur cells and normal RBCs was analyzed by a direct-phase high performance liquid chromatography column to separate both the phospholipids and acyl-Cn. There was less uptake of the [14C] arachidonate into phosphatidylethanolamine of spur cell RBCs (12.9% +/- 1.0%) compared with normal RBCs (20.5% +/- 2.8%; P = .0245). However, more arachidonate was incorporated into the acyl-Cn of spur cells (spur cell acyl-Cn [24.5% +/- 2.9%] v normal control acyl-Cn [10.1% +/- 1.9%]; P = .0018). We conclude that phospholipid biosynthesis is inhibited and that acyl-Cn formation is spared in spur cell anemia RBCs. These metabolic changes may help account for the lipid abnormalities seen in spur cell anemia RBCs and contribute to the hemolytic process.
A randomized, placebo-controlled trial of recombinant human granulocyte colony-stimulating factor administration in newborn infants with presumed sepsis: significant induction of peripheral and bone marrow neutrophilia
Authors: Gillan ER , Christensen RD , Suen Y , Ellis R , van de Ven C , Cairo MS
Published: October 2019

Host defenses in the human neonate are limited by immaturity in phagocytic immunity. Such limitations seem to predispose infected newborns to neutropenia from an exhaustion of the neutrophil reserve. Among the critical defects thus far identified in neonatal phagocytic immunity is a specific reduction in the capacity of mononuclear cells to express granulocyte colony-stimulating factor (G-CSF) after stimulation. However, the safety, pharmacokinetics, and biological efficacy of administration of recombinant human (rh)G-CSF to infected human newborns to compensate for this deficiency is unknown. Forty-two newborn infants (26 to 40 weeks of age) with presumed bacterial sepsis within the first 3 days of life were randomized to receive either placebo or varying doses of rhG-CSF (1.0, 5.0 or 10.0 micrograms/kg every 24 hours [36 patients] or 5.0 or 10.0 micrograms/kg every 12 hours [6 patients]) on days 1, 2, and 3. Complete blood counts with differential and platelet counts were obtained at hours 0, 2, 6, 24, 48, 72, and 96. Circulating G-CSF concentrations were determined at hours 0, 2, 6, 12, 14, 16, 18, 24, and 36. Tibial bone marrow aspirates were obtained after 72 hours for quantification of the bone marrow neutrophil storage pool (NSP), neutrophil proliferative pool, granulocyte progenitors, and pluripotent progenitors. Functional activation of neutrophils (C3bi expression) was determined 24 hours after rhG-CSF or placebo administration. Intravenous rhG-CSF was not associated with any recognized acute toxicity. RhG-CSF induced a significant increase in the blood neutrophil concentration 24 hours after the 5 and 10 micrograms/kg doses every 12 and 24 hours and it was sustained as long as 96 hours. A dose-dependent increase in the NSP was seen following rhG-CSF. Neutrophil C3bi expression was significantly increased at 24 hours after 10 micrograms/kg every 24-hour dose of rhG- CSF. The half-life of rhG-CSF was 4.4 +/- 0.4 hours. The rhG-CSF was well tolerated at all gestational ages treated. The rhG-CSF induced a significant increase in the peripheral blood and bone marrow absolute neutrophil concentration and in C3bi expression. Future clinical trials aimed at improving the outcome of overwhelming bacterial sepsis and neutropenia in newborn infants might include the use of rhG-CSF.
Appearance of a megakaryocyte growth-promoting activity, megapoietin, during acute thrombocytopenia in the rabbit
Authors: Kuter DJ , Rosenberg RD
Published: October 2019

Plasma obtained from rabbits made thrombocytopenic by the injection of antiplatelet serum (APS) stimulated megakaryocyte growth in an in vitro bone marrow culture. Although the number of megakaryocytes that grew was increased on average to 136%, the major effect was on megakaryocyte ploidy, which showed a shift in the modal ploidy class from 8N to 16N, an average change in the geometric mean ploidy from 8.7N to 11.8N, and the appearance of some 64N megakaryocytes. This in vitro stimulation of megakaryocyte number and ploidy was shown to be due to the appearance in the circulation of a positive activity, which we have named megapoietin. Levels of megapoietin in thrombocytopenic plasma could be quantitated by measuring the extent of megakaryocyte ploidization in vitro. The relationship over time of megapoietin to changes in the platelet count was then assessed in a series of rabbits made thrombocytopenic by APS injection. Although not elevated after 3 hours of thrombocytopenia, megapoietin increased after 8 hours to 48% of the maximal level, which occurred after 24 hours of thrombocytopenia. Levels of megapoietin were inversely and proportionally related to the platelet count during thrombocytopenia and the subsequent rebound thrombocytosis. During persistent thrombocytopenia, megapoietin levels remained maximally elevated. These results suggest that megapoietin may play a physiologic role in the feedback loop between the platelet and the bone marrow megakaryocytes.
Functional differences between CD38- and DR- subfractions of CD34+ bone marrow cells
Authors: Rusten LS , Jacobsen SE , Kaalhus O , Veiby OP , Funderud S , Smeland EB
Published: October 2019

Several studies have previously demonstrated enrichment in primitive progenitor cells in subfractions of CD34+ bone marrow (BM) cells not expressing CD38 or HLA-DR (DR) antigens. However, no studies have directly compared these two cell populations with regard to their content of primitive and more committed progenitor cells. Flow cytometric analysis of immunomagnetic isolated CD34+ cells demonstrated little overlap between CD34+CD38- and CD34+DR- progenitor subpopulations in that only 12% to 14% of total CD34+DR- and CD34+CD38- cells were double negative (CD34+CD38-DR-). Although the number of committed myeloid progenitor cells (colony-forming units granulocyte- macrophage) was reduced in both subpopulations, only CD34+CD38- cells were significantly depleted in committed erythroid progenitor cells (burst-forming units-erythroid). In single-cell assay, CD34+CD38- cells showed consistently poorer response to single as opposed to multiple hematopoietic growth factors as compared with unfractionated CD34+ cells, indicating that the CD34+CD38- subset is relatively enriched in primitive hematopoietic progenitor cells. Furthermore, CD34+CD38- and CD34+DR- cells, respectively, formed 3.2-fold and 1.6-fold more high proliferative potential colony-forming cell (HPP-CFC) colonies than did unfractionated CD34+ cells. Finally, CD34+CD38-DR- cells were depleted in HPP-CFCs as compared with CD34+CD38+DR+ cells. The results of the present study suggest that both the CD38- and DR- subfractions of CD34+ bone marrow cells are enriched in primitive hematopoietic progenitor cells, with the CD34+CD38- subpopulation being more highly enriched than CD34+DR- cells.