bluuebunny/crossref_metadata_2025_split huggingface dataset:
Expression of stem cell factor and c-kit in human neuroblastoma. The Children's Cancer Group
Authors: Cohen PS , Chan JP , Lipkunskaya M , Biedler JL , Seeger RC 
Published: October 2019

Abstract
During development, mice with mutations of stem cell factor (SCF) or its receptor c-kit exhibit defects in melanogenesis, as well as hematopoiesis and gonadogenesis. Because melanocytes derive from neural crest cells, the role of SCF and c-kit was investigated in the neural crest-derived childhood tumor neuroblastoma. Using reverse transcription-polymerase chain reaction analysis, simultaneous expression of steady-state mRNA for the SCF ligand and its receptor c- kit was found in 14 of 14 (100%) human neuroblastoma cell lines and clones and in 8 of 18 (45%) human neuroblastoma tumor samples. Functional blockade of c-kit receptors in the cell lines SK-N-BE(2) and SH-SY5Y using the mouse monoclonal anti-c-kit antibody SR-1 resulted in a significant decrease in cellular growth rate when measured by either 3H-thymidine incorporation or clonogenicity. In addition, higher levels of c-kit mRNA expression were associated with parental neuroblastoma cell lines and subclones with a neuronal (N) differentiation phenotype, whereas lower levels of c-kit mRNA were associated with neuroblastoma cell line subclones having a schwannian/glial/melanocytic pattern of differentiation. However, the differentiation phenotype of neuroblastoma cell lines was not directly altered when c-kit expression was blocked using the SR-1 antibody. In summary, these data indicate that c-kit receptor expression may play a significant role in the growth regulation of the two neuroblastoma cell lines examined and suggest that c-kit may also play a similar role in neuroblastoma growth regulation in vivo. Simultaneous expression of SCF and c-kit mRNA in both neuroblastoma cell lines and tumors implies that c-kit may act as part of an autocrine growth loop in conjunction with endogenous production of SCF in this disease.
Hereditary hemolytic anemia caused by diverse point mutations of pyruvate kinase gene found in Japan and Hong Kong
Authors: Kanno H , Wei DC , Chan LC , Mizoguchi H , Ando M , Nakahata T , Narisawa K , Fujii H , Miwa S 
Published: October 2019

Abstract
We identified four distinct point mutations in homozygous pyruvate kinase (PK) variants in Japanese and Chinese patients with chronic nonspherocytic hemolytic anemia. All gene abnormalities were missense mutations that caused single amino acid substitutions. 1261A (Q421K) and 1436A (R436H), which were identified in PK Sendai and PK Shinshu, had been found in unrelated Japanese and Amish PK variants, respectively. The clinical severity and extremely low residual erythrocyte PK activity of PK Shinshu as well as of the Amish PK might be caused partly by aberrant splicing, because the 1436A mutation changes a nucleotide at the last nucleotide in the exon 10. Recently, we diagnosed a 42-year-old Japanese woman with chronic nonspherocytic hemolytic anemia as having a homozygous PK deficiency. DNA sequencing of the variant PK gene showed a homozygous missense mutation at 1403GCT- ->GTT, resulting in a single amino acid substitution from 468la-->Val. The gene mutation is likely to impair the allostericity of this enzyme, speculated from the tertiary structure. A homozygous missense mutation in PK Hong Kong, a boy of a non-Han southern Chinese minority group, was identified in exon 7 of the human L-PK gene, 941ATT-->ACT, resulting in a single amino acid substitution from 314lle-->Thr. The R- PK activity is expected to be severely affected, because the mutated amino acid residue is located between the 313 Lys and the 315 Glu, which are very important for acid-base catalysis and magnesium binding, respectively. Both the R- and M2-type PK were shown by polyacrylamide gel electrophoresis of the PK Hong Kong erythrocyte lysate, and this is the first report of a homozygous individual whose erythrocytes contain the immature (M2)-type isozyme.
Characterization of recombinant plasminogen activator production by primate endothelial cells transduced with retroviral vectors
Authors: Dichek DA , Lee SW , Nguyen NH 
Published: October 2019

Abstract
Retroviral vector-mediated expression of plasminogen activators (PAs) from endothelial cells (ECs) has been proposed as a potential therapeutic approach for intravascular thrombosis. To define the potential for gene transfer to increase fibrinolytic activity in a primate system, baboon ECs were transduced with retroviral vectors expressing wild-type and glycosylphosphatidylinositol-anchored urokinase, as well as wild-type and serpin-resistant tissue PA (t-PA). Expression of either t-PA or urokinase was increased by one log over baseline levels. There was no specific effect of either t-PA or urokinase overexpression on endogenous t-PA, urokinase, or PA inhibitor 1 (PAI-1) expression. Recombinant urokinase could be anchored to the cell surface at a level eight-fold above that of receptor-bound urokinase. The majority of secreted urokinase accumulated in conditioned medium as a free proenzyme, whereas both wild-type and serpin-resistant t-PA accumulated almost exclusively in complexes with PAI-1. In most but not all of the assays, the urokinase vectors conferred PA activity above that of the t-PA vectors. These data show that PA synthesis and activity are specifically increased subsequent to retroviral vector-mediated gene transfer in primate ECs. However, definition of an optimal PA vector will require in vivo experimentation.
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

Abstract
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.
Antibodies to myeloid precursor cells in autoimmune neutropenia
Authors: Hartman KR , LaRussa VF , Rothwell SW , Atolagbe TO , Ward FT , Klipple G 
Published: October 2019

Abstract
Antibodies to mature blood neutrophils and to bone marrow myeloid cells have been described in the sera of some patients with apparent autoimmune neutropenia. To further explore the prevalence and specificities of antibodies to myeloid precursor cells, we evaluated sera from 148 patients with suspected autoimmune neutropenia for the presence of antibodies to neutrophils, to cultured myeloid cell lines, and to highly purified bone marrow myeloid progenitor cells. Using an immunofluorescence flow cytometric assay, we identified IgG antibodies in 42 (28%) of these sera that bound specifically to K562 cells, a multilineage cell line originally derived from a patient with chronic myelogenous leukemia. Twenty-two (15%) of the sera also contained IgG antibodies that bound specifically to the primitive myelomonocytic leukemia cell line KG1a. Twenty-five (17%) of the sera had IgG antibodies to myeloid cell lines in the absence of antibodies to mature neutrophils. There was a trend toward more severe neutropenia in patients with antibodies to K562 cells, without antineutrophil antibodies. In further studies, antibodies from 12 sera bound to mononuclear CD34+ cells that had been purified from normal human bone marrow by an immunomagnetic separation procedure. Moreover, two of these sera suppressed the growth of granulocyte-macrophage colony- forming units (CFU-GM) in methylcellulose cultures. The presence of antibodies to primitive hematopoietic cells in the sera of some patients with suspected immune neutropenia suggests that these antibodies may have a role in the pathogenesis of the neutropenia observed.
Characterization and purification of osteogenic cells from murine bone marrow by two-color cell sorting using anti-Sca-1 monoclonal antibody and wheat germ agglutinin
Authors: Van Vlasselaer P , Falla N , Snoeck H , Mathieu E 
Published: October 2019

Abstract
Osteogenic cells were sorted from bone marrow of 5-fluorouracil (5-FU)- treated mice based on light scatter characteristics, Sca-1 expression, and their binding to wheat germ agglutinin (WGA). Four sort gates were established using forward (FSC) and perpendicular (SSC) light scatter and were denominated as FSChigh SSClow, FSClow SSChigh, FSClow SSClow, and FSChigh SSChigh cell. Cells from the FSChigh SSChigh gate, but not from the other gates, synthesized alkaline phosphatase, collagen, and osteocalcin and formed a mineralized matrix in culture. The number of osteoprogenitor cells was significantly enriched after depleting the 5- FU bone marrow from cells of the lymphoid and myeloid lineage, eg, T cells, B cells, natural killer cells, granulocytes, macrophages, and erythrocytes. Approximately 95% of the FSChigh SSChigh cell population of this “lineage-negative” (Lin-) marrow expressed the Sca-1 antigen (Sca-1+) and bound WGA. Three additional sort windows were established based on WGA binding intensity and were denominated as Sca-1+ WGAdull, Sca-1+ WGAmedium, and Sca-1+ WGAbright. Cells from the Sca-1+ WGAbright gate, but not from the other gates, synthesized bone proteins and formed a mineralized matrix. However, they lost this capacity upon subcultivation. Further immunophenotypic characterization showed that FSChigh SSChigh Lin- Sca-1+ WGAbright cells expressed stromal (KM16) and endothelial (Sab-1 and Sab-2) markers, but not hematopoietic surface markers such as c-kit and Thy1.2. Sorted FSChigh SSChigh Lin- Sca-1+ WGAbright cells form three-dimensional nodules that stain with the von Kossa technique and contain osteoblast and osteocyte-like cells.
Mobilization of long-term hematopoietic reconstituting cells in mice by the combination of stem cell factor plus granulocyte colony-stimulating factor
Authors: Yan XQ , Briddell R , Hartley C , Stoney G , Samal B , McNiece I 
Published: October 2019

Abstract
In this study, we have compared the ability of recombinant human granulocyte colony-stimulating factor (rhG-CSF) alone and the combination of low doses of recombinant rat pegylated stem cell factor (rrSCF-PEG) plus rhG-CSF to mobilize peripheral blood progenitor cells (PBPCs) with long-term engrafting potential. Female recipient irradiated mice were transplanted with PBPCs from male mice that were mobilized with rhG-CSF alone (group A) or rrSCF-PEG plus rhG-CSF (group B). As previously shown, greater short-term survival resulted in group B compared with group A, with 80% and 40% survival at 30 days posttransplant, respectively. Both groups of animals showed long-term donor-derived engraftment in greater than 95% of animals, as determined by quantitative specific polymerase chain reaction amplification of a Y chromosome sequence from whole blood of the mice at 6 to 12 months posttransplantation. Analysis of individual granulocyte-macrophage colonies, picked up from semisolid methylcellulose culture of bone marrow cells from transplanted mice, resulted in detection of donor- derived DNA in 98% of colonies from group B mice compared with 81% from group A mice. These data show that cells with long-term potential are mobilized by rhG-CSF alone and the combination of rrSCF-PEG plus rhG- CSF. Furthermore, an increased number of cells with short-term and long- term engraftment potential was obtained with rrSCF-PEG plus rhG-CSF compared with rhG-CSF alone.
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

Abstract
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.
Plasmic degradation of fibrin rapidly decreases platelet adhesion and spreading
Authors: Hamaguchi M , Bunce LA , Sporn LA , Francis CW 
Published: October 2019

Abstract
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.
Maturation of acute T-lymphoblastic leukemia cells after CD2 ligation and subsequent treatment with interleukin-2
Authors: Mentz F , Ouaaz F , Michel A , Blanc C , Herve P , Bismuth G , Debre P , Merle-Beral H , Mossalayi MD 
Published: October 2019

Abstract
In this study, we have investigated the ability of various cytokines to induce the maturation of acute lymphoblastic leukemia (T-ALL) cells with early T-cell phenotype. Leukemic blasts from 17 untreated T-ALL patients were assayed for their ability to acquire mature T-cell markers, CD3/T-cell receptor (TCR) in particular, after incubation with one or a combination of recombinant human interleukin-1 (IL-1), IL-2, IL-4, IL-7, and CD2-specific monoclonal antibody (MoAb). IL-7 or IL-2 induced the proliferation of some leukemic cells, whereas sequential cell treatment with CD2-MoAb and then IL-2 promoted CD3/TCR expression on nearly all CD2+ cells (15 of 16), except for 1 T-ALL that developed into CD3-CD16+CD56+ cells. Differentiation of T-ALL cells was also evidenced through the downregulation of CD34 precursor cell antigen, the generation of CD4+ and CD8+ cells from CD4+ CD8+ precursors, and the acquisition of mature T-cell functions. CD2 ligation induced a progressive increase of surface expression of IL-2 receptor alpha (IL- 2R alpha) and IL-2R beta and an accelerated in vitro death of leukemic cells. The ligation of IL-2R by IL-2 rescued T-ALL cells from death and promoted their progression toward more mature cells expressing extracellular CD3/TCR alpha beta complexes. Intracellular analysis indicates that TCR alpha transcription and membrane translocation of both TCR alpha and TCR beta were promoted in these conditions. Analysis of intracellular signals transduced during T-ALL differentiation indicated that CD2-ligation induced Ca2+ influx and that the ligation of CD2 and IL-2R induced distinct tyrosine phosphorylation patterns. The addition of inhibitors of tyrosine phosphorylation abolished T-ALL cell differentiation, which suggests the involvement of tyrosine kinases in this phenomenon. Together, we showed the constant maturation of leukemic early T cells after stimulation of surface CD2 and the high- affinity IL-2R.
The regulatory element 3' to the A gamma-globin gene binds to the nuclear matrix and interacts with special A-T-rich binding protein 1 (SATB1), an SAR/MAR-associating region DNA binding protein
Authors: Cunningham JM , Purucker ME , Jane SM , Safer B , Vanin EF , Ney PA , Lowrey CH , Nienhuis AW 
Published: October 2019

Abstract
A cis-acting DNA regulatory element 3′ to the A gamma-globin gene contains eight distinct regions of DNA-protein interaction distributed over 750 bp of DNA. The sequences of two foot-printed regions (sites I and IV) are A-T rich and generate a highly retarded complex on gel shift analysis with nuclear extract from human erythroleukemia (K562) cells. We have purified a 98-kD protein that reproduces this gel shift. Tryptic cleavage and peptide sequence analysis demonstrated that the 98- kD protein is identical to a recently cloned protein, special A-T-rich binding protein 1 (SATB1), that binds selectively to nuclear matrix/scaffold-associated regions of DNA (MARs/SARs). We have shown by functional analysis that the 3′ A gamma regulatory element associates with the nuclear matrix. SATB1 mRNA was identified in K562 cells, and reverse transcriptase-polymerase chain reaction (RT-PCR) demonstrated its transcript in several other hematopoietic lines. Antisera to SATB1 caused ablation of the gel shift complex generated by both the crude nuclear extract and the purified 98-kD protein with the site I oligonucleotide. Furthermore, oligonucleotides that bind SATB1 inhibited formation of the site I gel shift complex when added as excess unlabeled competitor. An immunoblot analysis of the site I gel shift complex documented the presence of SATB1. Binding of SATB1 to two sites within the 3′ A gamma regulatory element and its MAR/SAR activity suggests that this element may influence gene expression through interaction with the nuclear matrix.
Corticosteroid modulation of interleukin-1 hematopoietic effects and toxicity in a murine system
Authors: Rinehart J , Delamater EW , Keville L , Measel J 
Published: October 2019

Abstract
Interleukin-1 (IL-1) has been shown to ameliorate the hematopoietic toxicities of antitumor chemotherapeutic agents in both mice and humans. However, IL-1 toxicity in humans is considerable and is similar to the systemic inflammatory toxicities induced by IL-3, IL-6, and other cytokines with pleiotropic biologic activities, eg, fever, nausea, malaise, and hypotension. We hypothesized that corticosteroids may reduce IL-1 toxicity without reducing IL-1 hematopoietic effects in vivo. C3H/HeJ mice (female, 6 weeks) were treated for 7 days subcutaneously with cortisone acetate (CA), (0.1, 0.25, or 0.5 mg/d/mouse), intraperitoneally with IL-1 (1 or 2 micrograms/d/mouse), or both. As expected, IL-1 increased white blood cell counts, splenic granulocyte-macrophage colony-forming units, and spleen cell number, and protected mice from lethal doses of carboplatin (200 mg/kg; Paraplatin, Bristol Laboratories, Evansville, IN) administered the day after completion of the 7 days of IL-1 administration. CA did not significantly block the hematopoietic effects of IL-1 or the ability of IL-1 to protect mice from the hematopoietic toxicity of carboplatin. IL- 1 administered to mice at 8 micrograms/d/mouse for 5 days induced decreased activity, roughening of hair, diarrhea, pancytopenia, multiple metabolic abnormalities, and death in 60% of mice. IL-1 at the therapeutic doses (0.5 to 2 micrograms/d) was not toxic. CA in a dose- dependent manner blocked all of the above mentioned toxicities when administered 24 hours and 30 minutes before each IL-1 injection. CA also decreased IL-1-induced increase in plasma tumor necrosis factor levels at the time point examined.