bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thrombolytic and pharmacokinetic properties of an immunoconjugate of single-chain urokinase-type plasminogen activator (u-PA) and a bispecific monoclonal antibody against fibrin and against u-PA in baboons
Authors: Imura Y , Stassen JM , Kurokawa T , Iwasa S , Lijnen HR , Collen D 
Published: October 2019

Abstract
Targeting of plasminogen activators to the fibrin component of a thrombus with the use of monoclonal antibodies (MA) directed against human fibrin may enhance their thrombolytic potency and fibrin- specificity. The thrombolytic and pharmacokinetic properties of rscu- PA/MA-FU1–74, an immunoconjugate of recombinant single-chain urokinase- type plasminogen activator (rscu-PA) and a bispecific MA directed against u-PA and against the beta-chain of human fibrin (MA-FU1–74), were investigated in baboons with a [125I]fibrin-labeled autologous blood clot in the femoral vein. Continuous intravenous infusion of rscu- PA/MA-FU1–74 (1:1.2 molar ratio) over 2 hours showed a fivefold increased thrombolytic potency (lysis per unit dose) over that of unconjugated rscu-PA, as evidenced both by a higher maximal rate of lysis (380% +/- 68% v 78% +/- 25% lysis per mg u-PA equivalent of compound administered per kg body weight, P less than .001), and by a lower dose at which the maximal rate of lysis occurs (0.19 +/- 0.03 v 0.82 +/- 0.10 mg compound per kg body weight, P less than .001). The specific thrombolytic activity (percent lysis per unit steady-state plasma u-PA antigen level) was lower for rscu-PA/MA-FU1–74 than for rscu-PA, as shown by both a lower maximal rate of lysis (60% +/- 13% v 220% +/- 22% lysis per microgram/mL u-PA antigen level in plasma, P less than .001) and a higher plasma antigen level at which maximal lysis is achieved (1.2 +/- 0.17 v 0.20 +/- 0.01 microgram/mL, P less than .001). The thrombolytic potency of rscu-PA/MA-UK1–3, an immunoconjugate of rscu-PA with the parental anti-u-PA antibody was similar to that of unconjugated rscu-PA. Clot lysis was achieved without systemic fibrinogen or alpha 2-antiplasmin consumption, and with a minor transient prolongation of the bleeding time. After the end of the infusions, u-PA-related antigen disappeared from plasma in a biphasic manner, with an initial half-life of 3.3 +/- 0.4 minutes for rscu-PA, 13 +/- 1 minutes for rscu-PA/MA-FU1–74, and 13 +/- 1 minutes for rscu-PA/MA-UK1–3, with corresponding plasma clearances of 340 +/- 28, 10 +/- 1, and 37 +/- 4 mL/min, respectively (mean +/- SEM). rscu- PA/MA-FU1–74 has a fivefold higher thrombolytic potency than unconjugated rscu-PA, as a result both of fibrin targeting by the specific idiotype of the antibody and of a slower plasma clearance.
Preferred sequence requirements for cleavage of pro-von Willebrand factor by propeptide-processing enzymes
Authors: Rehemtulla A , Kaufman RJ 
Published: October 2019

Abstract
Maturation of pro-von Willebrand factor (vWF) to its active form requires proteolytic processing after a pair of dibasic amino acids (- LysArg-) at residue 763. By coexpression of vWF and various propeptide processing enzymes in COS-1 cells, we here demonstrate that vWF is preferentially processed by the paired dibasic amino acid-cleaving enzyme PACE (furin). Processing of vWF by the yeast homologue of PACE, Kex2, was inefficient and not specific for the authentic site. Two additional recently identified mammalian propeptide-processing enzymes PC2 and PC3 had no detectable vWF-processing activity. The inability of PC2 and PC3 to cleave vWF was apparently not due to the absence of a transmembrane domain, since deletion of the transmembrane domain from PACE resulted in a secreted form which retained its propeptide processing activity within the secretory apparatus. The inability of PC2 and PC3 to process wild-type vWF or any of the vWF mutants described suggests different members of subtilisin-related propeptide- processing enzyme family have evolved to selectively recognize and cleave specific sets of substrates. In addition to paired dibasic residues at the propeptide cleavage site, many proteins, including vWF, also contain an arginine at the P4 position. We have generated mutant vWFs with substitutions at the P2 lysine and/or the P4 arginine to investigate their significance in substrate specificity. A conservative substitution of the P4 arginine by lysine resulted in a decrease in vWF processing by PACE, as did a nonconservative substitution to alanine. Substitution of the P2 lysine to aspartic acid decreased processing and little or no processing was detected when both the P4 and P2 were mutated to lysine and aspartic acid, respectively. These data indicate that both the P4 arginine and the P2 lysine play an important role in substrate recognition by PACE.
Expression of the interleukin-3 and granulocyte-macrophage colony- stimulating factor genes in Friend spleen focus-forming virus-induced erythroleukemia
Authors: Shimada Y , Migliaccio G , Ruscetti S , Adamson JW , Migliaccio AR 
Published: October 2019

Abstract
Friend spleen focus-forming virus (F-SFFV) is a replication-defective retrovirus that induces a multistage erythroleukemia in mice. In the first stage, expression of the SFFV envelope glycoprotein results in erythroid hyperplasia. Subsequently, the F-SFFV integrates near the Spi- 1 gene and activates its expression, resulting in immortalized cells that represent a second stage in the disease process. We report here that media conditioned by erythroleukemia cell lines or leukemic spleen cells induced by the polycythemia-inducing strain of F-SFFV (F-SFFVp), but not medium conditioned by SFFVp-induced hyperplastic spleens, promote the proliferation of normal granulocyte-macrophage progenitor cells and of granulocyte-macrophage colony-stimulating factor (GM-CSF)- and/or interleukin-3 (IL-3)-dependent cell lines. The colony- stimulating activity of the conditioned media from four of five of the lines studied was neutralized by antibodies specific for IL-3 and/or GM- CSF, and IL-3 and GM-CSF-specific mRNA could be detected in the cells after amplification by the polymerase chain reaction. No rearrangements of the IL-3 or GM-CSF genes were observed by Southern blot analysis. However, as previously shown for SFFV-induced cell lines, the Spi-1 gene was expressed in all of these cells. Because the Spi-1 gene encodes a transcription factor whose cognate sequences are present in the promoter region of many hematopoietic growth factor genes, including IL-3 and GM-CSF, Spi-1 activation may be inducing the expression of these genes.
A deletion/inversion rearrangement of the beta-globin gene cluster in a Turkish family with delta beta zero-thalassemia intermedia
Authors: Kulozik AE , Bellan-Koch A , Kohne E , Kleihauer E 
Published: October 2019

Abstract
The most common forms of hereditary persistence of fetal hemoglobin synthesis (HPFH) and delta beta zero-thalassemia result from simple deletions of the beta-globin gene cluster or from point mutations in the gamma-globin gene promoters. These naturally occurring mutants extend our understanding of globin gene regulation and hemoglobin switching. Furthermore, they provide the opportunity to test in vivo hypothetical switching models that are based on the experimental approach. We report here a family with delta beta zero-thalassemia from Turkey with a complex rearrangement of the beta-globin gene cluster that involves two deletions of 11.5 kb and 1.6 kb, and an inversion of 7.6 kb. The larger deletion removes both the delta-and the beta-globin genes with 3′ flanking sequences, whereas the smaller deletion affects DNA of unknown function. The inversion contains the entire L1 repeat 3′ of the beta-globin gene. There are structural motifs near the breakpoints (introduction of an “orphan” nucleotide, multiple direct and inverted repeats) suggesting a nonhomologous type of recombination event. The hematologic phenotype and the molecular structure of the rearranged beta-globin gene cluster are consistent with a competitive relationship between the fetal and the adult globin genes and/or with the translocation of enhancer sequences into the gamma-globin gene region.
Reduced deformability of thalassemic erythrocytes and erythrocytes with abnormal hemoglobins and relation with susceptibility to Plasmodium falciparum invasion
Authors: Bunyaratvej A , Butthep P , Sae-Ung N , Fucharoen S , Yuthavong Y 
Published: October 2019

Abstract
A number of genetically variant erythrocytes showed decreased deformability of both intact cells and membranes prepared therefrom as measured by laser diffractometry. Erythrocytes associated with minor or no clinical symptoms (eg, alpha-thalassemia traits, hemoglobin [Hb] E trait, Hb Constant Spring trait), which showed only a minimal decrease in deformability, were, in general, invaded efficiently by the malarial parasite Plasmodium falciparum. Other variant erythrocytes (beta- thalassemia/Hb E, homozygous Hb E, homozygous Hb Constant Spring, Hb H, Hb H/Hb Constant Spring) with low deformability showed different degrees of reduction in invasion susceptibility, most of which were less than proportional with deformability decrease. It is concluded that parasite invasion is only weakly related to gross cell deformability, which in turn depends on various factors other than membrane deformability.
Tumor necrosis factor-alpha modulation of glycoprotein Ib alpha expression in human endothelial and erythroleukemia cells
Authors: Rajagopalan V , Essex DW , Shapiro SS , Konkle BA 
Published: October 2019

Abstract
Glycoprotein Ib alpha (GpIb alpha) is a platelet membrane Gp that binds von Willebrand factor and mediates platelet adhesion to subendothelium. We have found both GpIb alpha mRNA and protein in human umbilical vein endothelial cells (HUVEC). In previously published work we reported that combined treatment with interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha) markedly increased the GpIb alpha mRNA level in HUVEC. We have now documented that TNF-alpha alone induces GpIb alpha mRNA and protein expression, studied the kinetics of this response, and investigated potential mechanisms of the TNF-alpha effect. GpIb alpha mRNA induction by TNF-alpha is detectable as early as 2 hours after exposure to this cytokine, and reaches a maximal level after 20 to 24 hours. Using a nuclear run-on assay we found that GpIb alpha gene transcription is increased approximately 10-fold after 2 hours of TNF-alpha treatment. Furthermore, using two monoclonal antibodies that recognize different epitopes of GpIb alpha, we found that the protein expression in endothelial cells is markedly increased by TNF-alpha. Interleukin-1 (IL-1) and the phorbol ester phorbol myristate acetate, which mimic many effects of TNF-alpha on endothelial cells, have no effect on endothelial or human erytholeukemia (HEL)-cell GpIb alpha mRNA. TNF-alpha treatment for 24 hours increases the HEL cell GpIb alpha mRNA level approximately fourfold, showing a time- and dose-dependent effect similar to that seen in HUVEC. TNF-alpha-induced GpIb alpha mRNA and protein synthesis may play a role in mediating platelet or other cell interaction with activated endothelium. Unlike other endothelial pro-thrombotic and pro-adhesive proteins induced by TNF-alpha, GpIb alpha is not induced by IL-1 treatment, which suggests a novel pathway for induction of this protein.
Measurement of basal levels of factor VIIa in hemophilia A and B patients [see comments]
Authors: Wildgoose P , Nemerson Y , Hansen LL , Nielsen FE , Glazer S , Hedner U 
Published: October 2019

Abstract
Previous results, presented in abstract form, indicate that replacement of thromboplastin with a mixture of phospholipid and truncated soluble tissue factor apoprotein results in a coagulation assay that can directly measure plasma factor VIIa levels without interference from zymogen factor VII (Atherosclerosis Thromb 11:1544a, 1991 [abstr]). We have exploited the specificity and sensitivity of such a factor VIIa specific coagulation assay to directly assess the in vivo relationship of factor VIII and factor IX on the production of factor VIIa levels under nonthrombotic and nonstimulatory conditions. Normal individuals (n = 20) were found to possess an average circulating factor VIIa level corresponding to 4.34 +/- 1.57 ng/mL, or approximately 1% of their total factor VII antigen. Severe factor VIII deficient patients (n = 13) possessed a slightly lower but statistically significant (P less than .01) decrease in their basal factor VIIa levels (2.69 +/- 1.52 ng/mL), corresponding to approximately 60% of that observed in normal individuals. On the other hand, severe factor IX deficient patients (n = 7) were found to possess even lower levels of factor VIIa corresponding to 0.33 +/- 0.15 ng/mL, or less than 10% of that observed in normal individuals. Measurement of total factor VII antigen levels shows that the variation in basal factor VIIa levels stems from differences in the degree of factor VII activation as opposed to differences in factor VII antigen levels. Our present data are consistent with the hypothesis that factor IXa is the principal in vivo activator of factor VII under basal conditions.
Hematopoietic stem cell depletion by restorative growth factor regimens during repeated high-dose cyclophosphamide therapy [see comments]
Authors: Hornung RL , Longo DL 
Published: October 2019

Abstract
We studied the effects of six cycles of repeated cyclophosphamide (CTX) therapy followed by restorative therapy with either granulocyte- macrophage colony-stimulating factor (GM-CSF) or G-CSF on the hematopoietic stem cell compartment. Stem cell function was assessed by serially transferring bone marrow cells from CTX-CSF-treated mice into lethally irradiated recipient mice. Bone marrow cells from mice that initially received either G-CSF or GM-CSF after CTX therapy more rapidly lost the ability to repopulate the recipient lymphoid organs, showed a dramatic loss of hematopoietic progenitors, a more rapid loss of CFU-S capacity, and a 40% to 50% reduction in marrow repopulating ability (MRA). Interleukin-1 (IL-1) appeared to have little effect on the CTX-treated mice when used alone. However, when administered before the CTX-CSF regimen, IL-1 prevented the stem cell depletion as determined by CFU-C, CFU-S, and MRA through the serial transplantation procedures. These results support the hypothesis that repeated treatments with myelosuppressive drugs followed by stimulation with the CSFs may induce damage to the host stem cell compartment, and further suggest that pretreatment with IL-1 before CTX therapy may prevent this stem cell damage.
Functional reconstitution of the human interleukin-3 receptor
Authors: Kitamura T , Miyajima A 
Published: October 2019

Abstract
The high-affinity receptors for human interleukin-3 (IL-3), GM-CSF, and IL-5 are composed of alpha and beta subunits. The alpha subunits are primary ligand binding proteins specific for each ligand, whereas the three human receptors share a common beta subunit (beta c). In contrast to humans mice have two closely related genes, AIC2A and AIC2B, which are homologous to human beta c. The AIC2A gene encodes a low-affinity murine IL-3 binding protein, and the AIC2B protein is the beta subunit shared between murine GM-CSF receptors (mGMR) and IL-5 receptors (mIL- 5R). To examine the function of these receptor components, we established various stable transfectants of murine IL-2-dependent CTLL- 2 cells. CTLL-2 transfectants expressing both the alpha and beta subunits of the human IL-3 receptor (hIL-3R) proliferated in response to physiologic concentrations of hIL-3. Coexpression of hIL-3R alpha with AIC2B but not with AIC2A in CTLL-2 cells conferred a growth response to hIL-3. Although CTLL-2 transfectants expressing hIL-3R alpha alone did not proliferate in the presence of hIL-3, hIL-3- responsive sublines were repeatedly isolated. These sublines expressed endogenous AIC2B but not AIC2A. These results indicate that human beta c is essential for hIL-3 signaling and that AIC2B is a murine equivalent of human beta c. We also showed that hIL-3 and hGM-CSF induced tyrosine phosphorylation of several proteins in CTLL transfectants, similar to those observed in human factor-dependent TF-1 cells stimulated with hIL-3 and hGM-CSF.
Differential effects of sequential, simultaneous, and single agent interleukin-3 and granulocyte-macrophage colony-stimulating factor on megakaryocyte maturation and platelet response in primates
Authors: Stahl CP , Winton EF , Monroe MC , Haff E , Holman RC , Myers L , Liehl E , Evatt BL 
Published: October 2019

Abstract
Recombinant granulocyte-macrophage colony-stimulating factor (GM-CSF) following interleukin-3 (IL-3) priming has been shown to increase thrombopoiesis. To elucidate the comparative abilities of IL-3 and GM- CSF in influencing megakaryocyte development in vivo, serial bone marrow analyses were performed on rhesus monkeys treated with 5 micrograms/kg/d of IL-3 and 5 micrograms/kg/d of GM-CSF sequentially for 4 days each, simultaneously for 8 days, and as single agents for 8 days. Platelet counts maximally increased to a mean of 7.5 x 10(5)/microL (n = 3) on days 11 through 12 in monkeys treated with sequential IL-3/GM-CSF. In contrast, neither IL-3 alone nor simultaneously administered IL-3/GM-CSF elicited increases in thrombopoiesis between days 3 and 15. GM-CSF elicited a variable platelet response. Megakaryocyte ploidy distributions were significantly (P < .001) shifted between days 7 and 10 in monkeys treated sequentially and between days 3 and 15 in monkeys treated with combined IL-3/GM-CSF and with GM-CSF alone but not in monkeys treated with IL-3 alone. The changes in mean DNA content and megakaryocyte size, as determined by digital image analysis, were larger in monkeys treated with sequential IL-3/GM-CSF and with GM-CSF alone than in simultaneously treated monkeys. In addition, sequentially but not simultaneously treated monkeys showed increased numbers of megakaryocytes on bone marrow biopsy. We conclude that administration of IL-3 followed by GM-CSF treatment increases thrombopoiesis by sequentially increasing megakaryocyte numbers and maturation and that these effects are diminished by simultaneous administration of the two cytokines.
Isolation of a cDNA clone encoding a zinc finger protein highly expressed in T-leukemia lines
Authors: Wu BY , Hanley EW , Turka LA , Nabel GJ 
Published: October 2019

Abstract
A cDNA clone encoding a novel zinc finger protein expressed in lymphoid cells has been isolated. This protein contains 5 repeats of the C2H2 motif previously described in the Drosophila gap gene, Kruppel, which is involved in embryo segmentation. Northern blot analysis showed that the messenger RNA (mRNA) encoding this protein is expressed at high levels in a variety of T-leukemia cell lines, at lower levels in some B cells, but is not observed in nonlymphoid cells. Within the T lineage, the mRNA is found at high levels in both alpha beta and gamma delta T cells. These data suggest that this cDNA, designated Hkr-T1, represents a gene that may contribute to the determination of the differentiation and the specificity within lymphoid cells.
t(9;14)(p13;q32) denotes a subset of low-grade non-Hodgkin's lymphoma with plasmacytoid differentiation
Authors: Offit K , Parsa NZ , Filippa D , Jhanwar SC , Chaganti RS 
Published: October 2019

Abstract
In this series of 426 consecutively ascertained, karyotypically abnormal non-Hodgkin's lymphomas (NHLs) derived from 407 patients, a t(9;14)(p13;q32) was encountered in 7 cases; an additional case demonstrated t(9;14)(p1?3;q32). At the time of detection of t(9;14), four cases were small lymphocytic lymphomas with plasmacytoid features; in three of these the t(9;14) was the sole karyotypic abnormality. In two cases of large-cell NHL demonstrating t(9;14), retrospective review of prior lymph node biopsies showed the presence of a small lymphocytic lymphoma of the plasmacytoid subtype. The remaining two cases comprised a large-cell lymphoma of the brain and a follicular NHL. Thus, six of eight cases (75%) had an initial identical low-grade histology. Immunohistochemical analysis of six cases showed no reactivity with CD1, CD2, CD4, CD5, CD8, and CD10 and high reactivity with CD19 and CD20. All four lymphocytic lymphomas and one of the two large-cell NHLs showed cytoplasmic Ig, consistent with plasmacytoid differentiation. Of the eight cases in this series, six presented with or developed stage IV disease; all were characterized by a 6-month to 5-year clinical phase of indolent disease before treatment was instituted. All five patients with low-grade NHL at the time of cytogenetic analysis were alive with recurrent disease at 3-year median follow-up. The remaining three patients with large-cell diffuse histologies relapsed after intensive therapy and expired at a median of 3 years from diagnosis; two of these showed previous or metachronous small lymphocytic tumors. These results suggest a novel biologically distinct subset of NHL; a neoplasm of mature B lymphocytes with plasmacytoid differentiation, characterized by t(9;14); and an indolent presentation followed by gradual clinical progression of disease.
Alteration of the proliferative rate of acute myelogenous leukemia cells in vivo in patients
Authors: Preisler HD , Raza A , Larson RA 
Published: October 2019

Abstract
Ten patients with active acute myelogenous leukemia (AML) received either 13 cis retinoic acid (RA) + alpha interferon (IFN) or recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) for 3 days. Cell cycle measurements were performed before and at the conclusion of administration of the bioactive agent(s). The proliferative rate of the leukemia cells in vivo decreased in four of five patients receiving RA+IFN whereas in one patient proliferation accelerated. The proliferative rate of AML cells accelerated in three of the five patients who received rhGM-CSF and slowed in two patients. These data show that while the proliferative rate of AML cells can be altered in vivo, the effect produced by bioactive agents may be the opposite of the desired effect. Furthermore, the studies described here demonstrate the usefulness of marrow biopsies for measuring the percent S-phase cells and the importance of measuring the duration of S phase so that the effects of bioactive agents on the cell cycle time of the leukemia cells can be determined.
Epstein-Barr virus burden in Hodgkin's disease is related to latent membrane protein gene expression but not to active viral replication
Authors: Joske DJ , Emery-Goodman A , Bachmann E , Bachmann F , Odermatt B , Knecht H 
Published: October 2019

Abstract
The Epstein-Barr virus (EBV) has been increasingly detected in Hodgkin's disease (HD), but its role in pathogenesis remains uncertain. We analyzed 20 specimens of HD known to contain EBV DNA by a sensitive reverse transcriptase polymerase chain reaction (RT-PCR). The cases were assessed for the presence of RNA transcripts of the BNLF1 gene (coding for the viral latent membrane protein [LMP]) and the late replicative gene BLLF1 (coding for the principle envelope glycoprotein [gp220/350]). LMP RNA transcripts were found in 9 of 20 (45%) cases, mostly those containing many copies of viral DNA and of mixed cellularity (MC) histological subtype. Only one LMP RNA-positive case was also positive for RNA transcripts of the active replication gene BLLF1. Our results show that viral burden in HD is not primarily related to active viral replication, but is associated with LMP gene expression.