bluuebunny/crossref_metadata_2025_split huggingface dataset:
Results of fludarabine and prednisone therapy in 264 patients with chronic lymphocytic leukemia with multivariate analysis-derived prognostic model for response to treatment [see comments]
Authors: O'Brien S , Kantarjian H , Beran M , Smith T , Koller C , Estey E , Robertson LE , Lerner S , Keating M 
Published: October 2019

Abstract
Two hundred sixty-four patients with chronic lymphocytic leukemia were treated with fludarabine 30 mg/m2 intravenously for 30 minutes each day for 5 days and with prednisone 30 mg/m2 orally each day for 5 days. Courses were repeated monthly. Of the 264 patients. 125 patients (47%) had Rai stage III-IV disease; 169 patients (64%) were previously treated with a median of 3 prior regimens; and 138 of them (82%) were refractory to therapy with alkylating agents. The overall response (OR) and complete response (CR) rates in the 169 previously-treated patients were 52% and 37%; these were 74% and 63%, respectively, in Rai stage O- II patients and declined to 64% and 46%, respectively, in Rai III-IV disease. Among the previously untreated patients, the OR and CR rates were 79% and 63%, these being 85% and 70%, respectively, in Rai O-II patients, and declining to 64% and 46%, respectively, in Rai III-IV disease. The incidence of minor infections or fever of unknown origin was similar in all patient groups and occurred in 22% of courses. The incidence of sepsis and/or pneumonia was significantly correlated with the extent of prior therapy and with Rai stage, and ranged from 3% of courses in the previously untreated Rai O-II patients, to 13% of courses in the previously treated Rai III-IV patients. Listeria sepsis or Pneumocystis carinii pneumonia was noted in 14 patients. With therapy, CD4 levels were uniformly depressed from a median 1,015/microL pretreatment to a median 159/microL after 3 months of fludarabine therapy. Median time to progression in previously treated patients was 22 months. In previously untreated patients, median time to progression was 30 months for patients who achieved a partial remission and has not been reached in patients who achieved a CR with a median follow-up of 2 years. The median survival was 18 months for previously treated patients and has not been reached for previously untreated patients. Response rates in previously treated and untreated patients, as well as infection rates, were identical to those seen in 110 patients treated with the same dose schedule of fludarabine alone. Logistic regression analysis selected 4 factors to be significantly associated with worse response: Rai III-IV stage disease, prior therapy, older age, and low albumin levels. The regression equation was used to derive a probability of response based on the 4 characteristics. When the model was applied to the same population, patients could be divided into 4 prognostic groups with different outcomes.
Elevated platelet count as a cause of abnormal von Willebrand factor multimer distribution in plasma
Authors: Budde U , Scharf RE , Franke P , Hartmann-Budde K , Dent J , Ruggeri ZM 
Published: October 2019

Abstract
Twelve of 19 patients with myeloproliferative disorders showed a decrease of absence of the largest multimers of plasma von Willebrand factor (vWF) that correlated with elevated platelet counts but not with leukocyte counts. This suggested that platelets, rather than leukocytes, may be associated with the pathogenesis of the acquired vWF abnormality seen in these patients. To examine the hypothesis further, we studied 12 patients with reactive thrombocytosis after splenectomy. Increased platelet count (> 5 x 10(11)/L) after splenectomy was associated with vWF abnormalities indistinguishable from those detected in patients with myeloproliferative disorders. Accordingly, there was an inverse correlation between proportion of large vWF multimers and platelet, but not leukocyte, number: normalization of the platelet count was accompanied by restoration of a normal vWF multimeric pattern. These findings suggest that an increase in the number of platelets circulating in blood may favor the adsorption of larger vWF multimers onto the platelet membrane, resulting in their removal from the circulation and subsequent degradation.
Demonstration of Rickettsia conorii-induced endothelial injury in vivo by measuring circulating endothelial cells, thrombomodulin, and von Willebrand factor in patients with Mediterranean spotted fever [see comments]
Authors: George F , Brouqui P , Boffa MC , Mutin M , Drancourt M , Brisson C , Raoult D , Sampol J 
Published: October 2019

Abstract
The endothelial cell (EC) is the primary target for Rickettsia conorii (RC) in Mediterranean spotted fever (MSF). Clinical manifestations such as thrombosis and vasculitis are mediated by pathologic changes localized in blood vessels. To study the in vivo endothelial injury induced by RC, markers of endothelial damage, including circulating EC (CEC), plasmatic thrombomodulin (TM), and von Willebrand factor (vWF), were investigated in 12 patients with MSF. CEC were counted in whole blood by a new immunomagnetic separation assay using a specific anti-EC antibody, S-Endo 1. Plasmatic TM and vWF antigens were measured by enzyme-linked immunosorbent assay. High levels of CEC and cell fragments were found in patients with a severe or malignant form of MSF. Sequential studies of CEC showed a decrease from 162 +/- 454 cells/mL before treatment to 6 +/- 7 cells/mL during treatment and recovery. Mean plasma TM and vWF levels that were also elevated before therapy (TM, 106 +/- 27 ng/mL; vWF, 420% +/- 164%) decreased progressively (TM, 55 +/- 43 ng/mL; vWF, 148% +/- 26%) during treatment. The measurement of cellular and molecular markers of vascular damage such as CEC, plasmatic TM, and vWF contributes to the definition of the Rickettsia-induced endothelial injury in vivo.
Impairment of chemoattractant-stimulated hexose uptake in neonatal neutrophils
Authors: Abughali N , Dubyak G , Tosi MF 
Published: October 2019

Abstract
Neonatal neutrophils (polymorphonuclear leukocytes [PMN]) exhibit a well-documented deficiency in chemotaxis, the nature of which has not been fully elucidated. To determine whether impaired ability of neonatal PMN to increase hexose uptake in response to chemoattractants could contribute to this defect, we compared uptake of 2-deoxy-D- glucose (2-DOG) in stimulated versus resting PMN from neonates (cord blood) and healthy adults. Compared with unstimulated values; N-formyl- methionyl-leucyl-phenylalanine (fMLP) (optimal at 10 nmol/L) caused a threefold to fourfold increase in 2-DOG uptake by adult PMN. Unstimulated 2-DOG uptake by neonatal PMN was slightly higher than that for adult cells, but fMLP caused only a minimal (less than twofold) increase, and optimally stimulated uptake was significantly lower than for adult PMN (P < .01 for adult versus neonatal stimulated uptake; n = 6). Findings were similar when ionomycin or C5a was used as a stimulus. Optimal fMLP stimulation of adult PMN was associated with a marked decrease in the Km for 2-DOG uptake, from 0.74 +/- 0.11 to 0.23 +/- 0.03 mmol/L (delta Km = -0.51 +/- 0.12 mmol/L; n = 6). In contrast, there was relatively little fMLP-induced change in the Km for uptake of 2-DOG by neonatal PMN (from 0.44 +/- 0.04 mmol/L to 0.32 +/- 0.019 mmol/L n = 6); delta Km = -0.12 +/- 0.04 mmol/L; P = .011 for adult versus neonatal delta Km. Stimulation with fMLP was not accompanied by a significant change in the Vmax for 2-DOG uptake with either adult or neonatal PMN, and the respective values for Vmax were similar. We conclude that the chemoattractant-induced increase in hexose uptake by PMN is deficient in neonates compared with adults and that this deficiency involves mechanisms that determine the Km for this process. This impairment may contribute to defective chemotaxis in neonatal PMN.
Competition between plasminogen and tissue plasminogen activator for cellular binding sites
Authors: Felez J , Chanquia CJ , Fabregas P , Plow EF , Miles LA 
Published: October 2019

Abstract
Cellular receptors for plasminogen and tissue plasminogen activator (t- PA) regulate plasminogen activation and cell-associated proteolytic activity. The characteristics of the interactions of both ligands with monocytes and monocytoid cell lines bear certain similarities, including affinity (kd approximately 1 mumol/L) capacity and susceptibility to carboxypeptidase treatment. Therefore, we have undertaken the present study to determine directly whether t-PA and plasminogen share common binding sites on cells. We found that recombinant human single-chain t-PA (rt-PA) could inhibit the binding of 125I-plasminogen to the cells and, conversely, plasminogen could inhibit 125I-rt-PA binding. This relationship was observed with 9 cell types, including both adherent cells and cells in suspension. In addition, under several conditions of cell treatment, plasminogen and t- PA receptor expression was modulated in parallel. Furthermore, molecules that have been implicated as candidate plasminogen receptors, gangliosides, and an alpha-enolase--related molecule, also interacted with t-PA. These results suggest that at least a component of the binding sites for plasminogen is shared with t-PA. Occupancy of these sites by either or both ligand(s) should result in arming the cells with the proteolytic activity of plasmin.
A model of in vivo cell proliferation of adult T-cell leukemia
Authors: Kondo A , Imada K , Hattori T , Yamabe H , Tanaka T , Miyasaka M , Okuma M , Uchiyama T 
Published: October 2019

Abstract
We have made a model of in vivo cell proliferation of leukemic cells from adult T-cell leukemia (ATL) patients using severe combined immunodeficiency (SCID) mice. Peripheral blood mononuclear cells (PBMC) or lymph node cells (LNC) depleted of B cells and monocytes were intraperitoneally injected into SCID mice treated with antimurine interleukin-2 receptor (IL-2+) beta chain monoclonal antibody (MoAb)(TM- beta 1), followed by daily injection of human recombinant IL-2 until 60 days after cell injection. SCID mice injected with ATL cells from 6 of 8 ATL patients were found to have the tumor or leukemia 5 to 7 weeks after the inoculation of cells. Serum levels of soluble form of human IL-2R alpha chain (Tac) were markedly elevated in such mice. The cells recovered from the mice injected with leukemic cells from four different ATL patients had the same cell surface phenotype as that of original leukemic cells which were CD4+Tac+. Furthermore, we detected the same integration site of human T-cell leukemia virus type I (HTLV- I) provirus and the same rearrangement pattern of human T-cell receptor (TCR) beta chain gene as those of ATL cells by Southern blot hybridization, indicating that the cells proliferating in SCID mice were derived from the original ATL cell clone. Histologic examination showed that the pattern of the infiltration of ATL cells into various organs in SCID mice was similar to that of an ATL patient. Such a model of in vivo cell proliferation of ATL cells will be useful for the study of the mechanism of neoplastic cell proliferation and for the development of a new and effective treatment of ATL.
The N-terminal domain of human urokinase receptor contains two distinct regions critical for ligand recognition
Authors: Pollanen JJ 
Published: October 2019

Abstract
The high-affinity receptor that binds human urokinase-type plasminogen activator (hu-PAR) is a glycosyl-phosphatidylinositol (GPI)-anchored cell-surface glycoprotein that belongs to the Ly-6 superfamily of T- cell-activating receptors. Binding of urokinase (u-PA) to u-PAR is species-specific, since neither murine (mu-PAR) nor hu-PAR binds u-PA from the other species. I designed and analyzed a series of exchanges between hu-PAR and mu-PAR in the N-terminal first domain to which ligand-binding function had been independently mapped. Introduction of as few as 13 murine residues (six of 13 variables) into the N-terminal region of hu-PAR abrogated binding to recombinant human pro-u-PA, whereas the opposite chimera, a mu-PAR carrying six of 13 human residues, was positive for binding. Within this region, the mu-PAR domain 1 could be minimally humanized to bind human pro-u-PA by a substitution of as few as four of the six nonconserved residues, thereby identifying the residues arginine-2, lysine-7, threonine-8, and glycine-10 as important in determining binding specificity. By alanine- scanning mutagenesis, a second recognition site within domain 1 was discovered between residues 47 and 53, a segment that is fully conserved between the human and the mouse receptors. Taken together, these results provide identification of two confined subregions within the N-terminal domain of hu-PAR critically involved in pro-u-PA recognition.
Differential regulation of human B-lymphocyte tumor necrosis factor- alpha (TNF-alpha) and lymphotoxin (TNF-beta) production by protein phosphatase 1 and 2A inhibitor
Authors: Xia HZ , Kannapell CC , Fu SM , Sung SS 
Published: October 2019

Abstract
Tumor necrosis factor (TNF) and lymphotoxin (LT; TNF-beta) are major cytokines produced by B lymphocytes. Stimulation by okadaic acid, a phosphatase 1 and 2A inhibitor, markedly increased TNF mRNA accumulation and cytokine production. On the other hand, the accumulation of LT mRNA was not affected by okadaic acid despite structural and functional similarities between TNF and LT. The increase in TNF mRNA accumulation was due to the stimulation of gene transcription and a marked stabilization of this mRNA. The binding activities of the transcription factors AP-1 and AP-2 and NF kappa B, which regulates TNF gene transcription, were also stimulated by okadaic acid. In addition, okadaic acid was shown to increase TNF production at the protein level. These results show the importance of protein phosphatases in the regulation of cytokine production in B cells, and further identifies differences in the regulation of TNF-alpha and LT production.
Murine myeloid cells transformed by myb require fibroblast-derived or autocrine growth factors in addition to granulocyte-macrophage colony- stimulating factor for proliferation
Authors: Macmillan EM , Gonda TJ 
Published: October 2019

Abstract
Murine myeloid cells can be transformed in vitro by infection with recombinant retroviruses carrying activated myb genes. While these myb- transformed hematopoietic cells (MTHCs) can proliferate continuously in culture, they exhibit several characteristics of progenitor cells of the granulocyte-macrophage (GM) lineage, including an absolute dependence on hematopoietic growth factors (HGFs) such as GM colony- stimulating factor (GM-CSF) for survival and growth. Whereas we have previously shown that MTHCs respond synergistically to certain combinations of HGFs, we report here that MTHCs apparently require two HGFs for proliferation, because GM-CSF alone appears insufficient to promote growth when MTHCs are cultured at very low densities. However, proliferation can be stimulated by either increasing the density at which MTHCs are cultured (implying the production of an autocrine growth factor) or by the presence of a feeder layer of irradiated fibroblasts. We find that the activity of such feeder layers is greatest when the MTHCs are allowed to contact them directly; and by using mutant fibroblast lines, that it depends on the production of CSF- 1, but not Steel factor (SLF). In contrast, the autocrine factor appears not to be either CSF-1 or SLF, and the possibility is raised that it may represent a novel HGF activity. Potential implications of these results for normal and leukemic hematopoiesis are discussed.
Human monocytes support factor X activation by factor VIIa, independent of tissue factor: implications for the therapeutic mechanism of high- dose factor VIIa in hemophilia [see comments]
Authors: Hoffman M , Monroe DM , Roberts HR 
Published: October 2019

Abstract
High doses of recombinant factor VIIa are useful in managing bleeding in hemophiliacs with inhibitors. Whether this therapeutic effect of factor VIIa is dependent on tissue factor (TF) is a matter of debate. We examined the ability of freshly isolated human monocytes (which lack TF) to support the activation of coagulation-factor X by factor VIIa. The rate of factor-X activation by factor VIIa was accelerated in the presence of monocytes compared with the rate of X activation in solution. This activation of factor X on monocytes was saturable with a K1/2 of about 400 to 600 pmol/L factor VIIa. The rate of activation was not inhibited by an excess of inhibitory anti-TF antibody or a Gla- containing fragment of prothrombin. In contrast to monocytes, an endothelial cell line did not support activation of factor X by factor VIIa. Our findings suggest that at least one cell type can accelerate activation for factor X by factor VIIa in the absence of TF. This activity requires higher concentrations of factor VIIa than does the TF mechanism. The concentrations of VIIa required are of a similar order of magnitude to those required for a therapeutic effect of VIIa in bleeding hemophiliacs with inhibitors.
Splenic primitive hematopoietic stem cell (PHSC) activity is enhanced by steel factor because of PHSC proliferation
Authors: Harrison DE , Zsebo KM , Astle CM 
Published: October 2019

Abstract
To test whether primitive hematopoietic stem cells (PHSCs) are stimulated by Steel (SI) factor (c-kit ligand) in vivo, donor mice were studied after three or seven daily injections of SI factor. PHSC activity was measured as long-term erythroid and lymphoid competitive repopulating ability. Cells to be tested (usually marrow or spleen cells from treated donors) were mixed with untreated competitor marrow that produces erythrocytes and lymphocytes that are genetically distinguishable from the donors by differences in hemoglobin (Hb) and glucosephosphate isomerase (GPI) markers. These cell mixtures were injected into lethally irradiated hosts, and after 111 to 293 days, functional abilities of donor PHSC populations were assessed and expressed as percentages of donor-type Hb and GPI in the host's circulating erythrocytes and lymphocytes, respectively. A striking increase in splenic PHSC activity occurred after seven daily injections of SI factor, with a much smaller increase after three daily injections. Both three and seven daily injections of SI factor slightly reduced marrow PHSC activity. Rapid cycling greatly increases PHSC vulnerability to 5-fluorouracil (5FU). To test whether SI factor stimulates PHSCs into rapid cycling, donor mice were given a dose of 5FU in addition to SI factor. The increase in splenic PHSCs after 7 days of treatment with SI factor occurred to a similar degree whether donors were or were not treated with 5FU on day 8. However, a dose of 5FU on day 4 of the SI factor treatments almost totally prevented the increase in splenic PHSC activity. Apparently this increased activity requires PHSC cycling throughout the period of SI factor treatment.
Bifunctional effects of tumor necrosis factor alpha (TNF alpha) on the growth of mature and primitive human hematopoietic progenitor cells: involvement of p55 and p75 TNF receptors
Authors: Rusten LS , Jacobsen FW , Lesslauer W , Loetscher H , Smeland EB , Jacobsen SE 
Published: October 2019

Abstract
Tumor necrosis factor alpha (TNF alpha) has previously been reported to have both inhibitory and stimulatory effects on hematopoietic progenitor cells. Specifically, TNF alpha has been proposed to stimulate early hematopoiesis in humans. In the present study we show that TNF alpha, in a dose-dependent fashion, can potently inhibit the growth of primitive high proliferative potential colony-forming cells (HPP-CFCs) stimulated by multiple cytokine combinations. Using agonistic antibodies to the p55 and p75 TNF receptors or TNF alpha mutants specific for either of the two TNF receptors, we show that both receptors can mediate this inhibition. In contrast, the potent stimulation of interleukin-3 (IL-3) plus granulocyte-macrophage colony- stimulating factor (GM-CSF) induced HPP-CFC colony formation observed at low concentrations of TNF alpha (2 ng/mL) was only a p55-mediated event. Moreover, the stimulatory effects of TNF alpha on GM-CSF or IL-3- induced colony formation, as well as the inhibition of G-CSF-induced colony growth, were also exclusively signaled through the p55 TNF receptor. Taken together, our results suggest that the inhibitory effects of TNF alpha on primitive bone marrow progenitor cells are mediated through both p55 and p75 TNF receptors, whereas the p55 receptor exclusively mediates the bidirectional effects on more mature, single factor-responsive bone marrow progenitor cells as well as stimulation of IL-3 plus GM-CSF-induced HPP-CFC colony growth.
No evidence for genomic imprinting of the human BCR gene
Authors: Fioretos T , Heisterkamp N , Groffen J 
Published: October 2019

Abstract
Chronic myeloid leukemias and 5% to 20% of acute lymphoid leukemias are characterized by the Philadelphia chromosome, a reciprocal chromosomal translocation, t(9;22)(q34;q11), generating BCR-ABL and ABL-BCR fusion genes. Cytogenetic studies have recently shown a preferential involvement of the paternally derived chromosome 9 and the maternally derived chromosome 22 in this translocation, indicating that imprinting might be involved in the formation or selection of the translocation. In this study, we have identified a BamHI polymorphism in the coding region of BCR exon 1, allowing us to investigate whether both BCR alleles are transcribed. By using a reverse transcriptase-polymerase chain reaction assay, we show that both BCR alleles are expressed in the peripheral blood cells of normal individuals.
The activation-induced decrease in the platelet surface expression of the glycoprotein Ib-IX complex is reversible
Authors: Michelson AD , Benoit SE , Kroll MH , Li JM , Rohrer MJ , Kestin AS , Barnard MR 
Published: October 2019

Abstract
Thrombin decreases the platelet surface expression of the glycoprotein (GP) Ib-IX complex. To determine whether this effect is reversible, flow cytometric studies were performed with GPIb-IX-specific monoclonal antibodies. In both whole blood and washed platelet systems, incubation of platelets with thrombin or a combination of adenosine diphosphate and epinephrine resulted in a maximal decrease of the platelet surface expression of GPIb-IX within 5 minutes, after which there was a time- dependent return of the platelet surface GPIb-IX complex, which was maximal by 60 minutes. Exposure of the same platelets to additional exogenous thrombin resulted in a second decrease in platelet surface GPIb-IX, followed by a second reconstitution of platelet surface GPIb- IX. Throughout these experiments there was no measurable release from the platelets of glycocalicin (a proteolytic fragment of GPIb). Experiments in which platelets were preincubated with a biotinylated GPIb-specific MoAb showed that the GPIb molecules that returned to the platelet surface were the same molecules that had been translocated to the intraplatelet pool. The GPIb molecules that returned to the platelet surface were functionally competent to bind von Willebrand factor, as determined by ristocetin-induced platelet agglutination and ristocetin-induced binding of exogenous von Willebrand factor. Inhibitors of protein kinase C and myosin light-chain kinase enhanced the reexpression of platelet surface GPIb. In summary, the activation- induced decrease in the platelet surface expression of the GPIb-IX complex is reversible. Inactivation of protein kinase C and myosin light-chain kinase are important mechanisms in the reexpression of the platelet surface GPIb-IX complex.