bluuebunny/crossref_metadata_2025_split huggingface dataset:
Heparin-stimulated inhibition of factor IXa generation and factor IXa neutralization in plasma
Authors: Pieters J , Lindhout T , Willems G 
Published: October 2019

Abstract
Generation and inhibition of activated factor IXa was studied in factor XIa-activated plasma containing 4 mmol/L free calcium ions and 20 mumol/L phospholipid (25 mol% phosphatidylserine/75 mol% phosphatidylcholine). Interference of other (activated) clotting factors with the factor IXa activity measurements could be avoided by using a highly specific and sensitive bioassay. Factor IXa generation curves were analyzed according to a model that assumed Michaelis-Menten kinetics of factor XIa-catalyzed factor IXa formation and pseudo first order kinetics of inhibition of factor XIa and factor IXa. In the absence of heparin, factor IXa activity in plasma reached final levels that were found to increase with increasing amounts of factor XIa used to activate the plasma. When the model was fitted to this set of factor IXa generation curves, the analysis yielded a rate constant of inhibition of factor XIa of 0.7 +/- 0.1 min-1 and a kcat/Km ratio of 0.29 +/- 0.01 (nmol/L)-1 min-1. No neutralization of factor IXa activity was observed (the estimated rate constant of inhibition of factor IXa was 0). Thus, in the absence of heparin, the final level of factor IXa in plasma is only dependent on the initial factor XIa concentration. While neutralization of in situ generated factor IXa in normal plasma was negligible, unfractionated heparin dramatically enhanced the rate of inactivation of factor IXa (apparent second order rate constant of inhibition of 5.2 min-1/per microgram heparin/mL). The synthetic pentasaccharide heparin, the smallest heparin chain capable of binding antithrombin III, stimulated the inhibition of in situ generated factor IXa, but sevenfold less than unfractionated heparin (k = 0.76 min-1 per microgram pentasaccharide/mL). We found that free calcium ions were absolutely required to observe an unfractionated heparin and pentasaccharide-stimulated neutralization of factor IXa activity. Factor XIa inhibition (psuedo first order rate constant of 0.7 min-1) was not affected by unfractionated heparin or pentasaccharide in the range of heparin concentrations studied.
Establishment and characterization of a granulocyte-macrophage colony- stimulating factor-dependent human myeloid cell line
Authors: Oez S , Tittelbach H , Fahsold R , Schaetzl R , Buhrer C , Atzpodien J , Kalden JR 
Published: October 2019

Abstract
A new human myeloid cell line has been established recently from the bone marrow cells of a patient with chronic myelogenous leukemia in blast crisis. The active proliferation and survival of the cells in RPMI 1640 medium containing fetal calf serum are clearly dependent on the presence of either natural or recombinant human granulocyte- macrophage colony-stimulating factor (rhGM-CSF). Despite permanent culturing in rhGM-CSF (100 U/mL), the cells do not differentiate and bear the myelomonocytic surface markers CD34, CD13, CD36, as well as HLA-DR, but not CD3, CD7, CD10, CD11b, CD14, CD20, or CD42b. The predominant karyotype, apart from tetraploidy in several cells, is 45, XX, -9, -17, -19, -22, 7p-, 9q+ (der t[9;22]), der (13q), with three additional marker chromosomes, from which one was observed in the patient's leukemic cells. On BglII-digested DNA, Southern blot analysis with bcr 5′ as the probe detected two additional hybridizing restriction fragments of 8.6 and 11.0 kilobase pairs.
Chromosomal breakpoints within the first intron of the ABL gene are nonrandom in patients with chronic myelogenous leukemia
Authors: Jiang XY , Trujillo JM , Liang JC 
Published: October 2019

Abstract
Bone marrow cells from 37 patients with chronic myelogenous leukemia (CML), who had the characteristic Philadelphia chromosome in their leukemic cells, were examined for ABL gene rearrangement by pulsed- field gel electrophoresis. By using several probes from the ABL gene, we found that in 33 of 37 (89%) patients studied, the translocation breakpoints in ABL fell within the 175-kilobase (kb) intron between exons 1b and 1a. Furthermore, breakpoints in this intron clustered in three regions, approximately 30 +/- 5, 100 +/- 13, and 135 +/- 8 kb downstream from exon 1b. These findings suggest that there may be specific sequences in this intron that facilitate the processes of chromosomal translocation.
Effects of recombinant human interleukin-3 in patients with normal hematopoiesis and in patients with bone marrow failure
Authors: Ganser A , Lindemann A , Seipelt G , Ottmann OG , Herrmann F , Eder M , Frisch J , Schulz G , Mertelsmann R , Hoelzer D 
Published: October 2019

Abstract
In a phase I/II study, 19 patients with advanced tumors but normal hematopoiesis and nine patients with bone marrow failure and prolonged severe cytopenias were treated with recombinant human interleukin-3 (rhIL-3) to assess the toxicity and biological effects of this multipotential hematopoietic growth factor. Doses ranging from 30 micrograms/m2 to 500 micrograms/m2 were administered as subcutaneous bolus injection daily for 15 days. A dose-dependent increase in platelet counts ranging from 1.3-fold at 60 micrograms/m2 to 1.9-fold at 250 micrograms/m2 was induced by rhIL-3 in 15 of 18 evaluable patients with normal hematopoiesis. An increase in reticulocyte counts was observed in 14 patients. The blood leukocyte counts dose dependently increased 1.4- to 3.0-fold. In patients with bone marrow failure, platelet counts increased by a mean of sixfold (range, 1.3- fold to 14.3-fold) in five of eight evaluable patients. Reticulocyte counts increased 4.4-fold in six patients, and neutrophil counts increased by a mean of 3.1-fold in all eight patients. Platelet transfusions could be discontinued after treatment with rhIL-3 in two of three transfusion-dependent patients. Only mild side effects, mainly fever, headache, and flushing, were observed. These results indicate that rhIL-3 functions as a multilineage hematopoietin in vivo in patients with normal bone marrow function and in patients with secondary bone marrow failure.
An analysis of megakaryocytopoiesis in the C3H mouse: an animal model whose megakaryocytes have 32N as the modal DNA class
Authors: Jackson CW , Steward SA , Chenaille PJ , Ashmun RA , McDonald TP 
Published: October 2019

Abstract
The modal DNA content of normal marrow megakaryocytes from species so far examined usually has been reported to be 16N. In this report we describe an exception in the C3H mouse whose megakaryocytes have a modal DNA content of 32N. Female C3H/HEN mice had an average DNA content distribution of 14% 8N, 37% 16N, 43% 32N, and 6% 64N. Male C3H/HEN mice had somewhat higher proportions of 32N and 64N megakaryocytes (average DNA content distribution of 12% 8N, 29% 16N, 47% 32N, and 12% 64N) than females. All 11 other mouse strains examined had 16N as the modal megakaryocyte DNA content, although the proportions in the various polyploid DNA classes showed some strain variation. Megakaryocyte size was similar among all 12 strains evaluated, and mean platelet volume (MPV) of C3H/HEN mice differed from only 1 of the other 4 strains analyzed. Platelet counts of C3H/HEN mice were similar to those of six, and slightly but significantly lower than those of five other mouse strains examined. Compared with megakaryocyte concentrations of other mouse strains studied, that of C3H/HEN mice was similar to seven, somewhat higher than one, and slightly lower than three strains. Offspring from reciprocal matings of C57BL/6 and C3H/HEN mice had megakaryocyte DNA distributions intermediate between those of the parent strains, suggesting that a higher gene dosage of some component is responsible for the right-shifted megakaryocyte DNA content distribution phenotype of C3H mice. The proportions of 32N and 64N megakaryocytes increased in C3H/HEN mice in response to acute thrombocytopenia, as did those of CBA/CAJ mice used as a comparative strain. In summary, megakaryocytes of the C3H mouse have a higher average DNA content but similar platelet count, MPV, and megakaryocyte size and concentration as those of most other mouse strains. These results suggest that the number of platelets produced per unit of C3H megakaryocyte DNA is less than that for other mice.
Detection and isolation of the erythropoietin receptor using biotinylated erythropoietin
Authors: Wognum AW , Lansdorp PM , Humphries RK , Krystal G 
Published: October 2019

Abstract
Procedures have been developed to label human erythropoietin (Ep) with biotin to detect and isolate the Ep-receptor. The labeling method used the abundant carbohydrate groups on Ep and resulted in biologically active biotin-Ep (b-Ep) containing 8 to 10 biotins per Ep molecule. Specific binding of b-Ep to cells from spleens of mice made anemic by phenylhydrazine injections was demonstrated using 125I-labeled streptavidin. B-Ep, together with fluorescently tagged streptavidin, was found to specifically detect Ep-receptor-bearing cells by flow cytometry. This was demonstrated in several ways. First, approximately 90% of nucleated spleen cells from phenylhydrazine-treated mice were clearly fluorescent after staining with b-Ep and streptavidin- phycoerythrin, whereas only background fluorescence was detected using spleen cells from untreated mice. In addition, Ep-receptors were detected on 5% to 10% of normal mouse bone marrow cells, and these cells could be identified as erythroid in nature by separating the cells into subpopulations based on light-scatter properties. Third, Ep- receptor expression was found to correlate positively with expression of transferrin receptors, confirming the erythroid nature of these cells. B-Ep was also used to isolate Ep-receptors from monkey COS cells transfected with the murine Ep-receptor cDNA. In these experiments a cell-surface-bound protein of approximately 65 Kd and an intracellular protein of approximately 60 Kd were isolated from these cells. The procedures described in this report for detecting Ep-receptor expressing cells and for isolating the Ep-receptor should be valuable for purifying erythroid cells from heterogeneous cell populations, for elucidating the structure of the Ep-receptor, and for studying the biological activities of Ep at the cellular and molecular level.
Factor IX is activated in vivo by the tissue factor mechanism
Authors: Bauer KA , Kass BL , ten Cate H , Hawiger JJ , Rosenberg RD 
Published: October 2019

Abstract
Despite significant progress in elucidating the biochemistry of the hemostatic mechanism, the process of blood coagulation in vivo remains poorly understood. Factor IX is a vitamin K-dependent glycoprotein that can be activated by factor XIa or the factor VII-tissue factor complex in vitro. To investigate the role of these two pathways in factor IX activation in humans, we have developed a sensitive procedure for quantifying the peptide that is liberated with the generation of factor IXa. The antibody population used for the immunoassay was raised in rabbits and chromatographed on a factor IX-agarose immunoadsorbent to obtain antibody populations with minimal intrinsic reactivity toward factor IX. We determined that the mean level of the factor IX activation peptide (FIXP) in normal individuals under the age of 40 years was 203 pmol/L and that levels increased significantly with advancing age. The mean concentration of FIXP was markedly reduced to 22.7 pmol/L in nine patients with hereditary factor VII deficiency (factor VII coagulant activity less than 7%) but was not significantly different from normal controls in nine subjects with factor XI deficiency (factor XI coagulant activity less than 8%). These data indicate that factor IXa generation in vivo results mainly from the activity of the tissue factor mechanism rather than the contact system (factor XII, prekallikrein, high molecular-weight kininogen, factor XI). Our results may also help to explain the absence of a bleeding diathesis in many patients with deficiencies of the contact factors of coagulation.
Molecular genetics of gastrointestinal non-Hodgkin‧s lymphomas: unusual prevalence and pattern of c-myc rearrangements in aggressive lymphomas
Authors: van Krieken JH , Raffeld M , Raghoebier S , Jaffe ES , van Ommen GJ , Kluin PM 
Published: October 2019

Abstract
Thirty-two extranodal lymphomas of the gastrointestinal (GI) tract underwent molecular genetic analysis by Southern blotting using probes for the immunoglobulin genes and the bcl-1, bcl-2, and c-myc loci, commonly involved in lymphomagenesis. No bcl-1 rearrangements were found. There was only one large-cell lymphoma with a bcl-2 rearrangement. A rearrangement of the c-myc gene was found in six of eight Burkittlike lymphomas of the intestine. In five of these six cases, a chromosomal translocation t(8;14) with an unusual breakpoint was demonstrated by comigration of the rearranged c-myc and a rearranged JH sequence. This pattern of rearrangement has not been previously associated with a specific group of non-Hodgkin's lymphomas. In contrast to all six low-grade lymphomas, c-myc rearrangements were found in 6 of 12 large-cell or high-grade mucosa-associated lymphomas of the stomach. No comigration of c-myc and immunoglobulin heavy-chain gene sequences were found. We conclude that primary GI lymphomas have different molecular genetic characteristics compared with node-based follicle center-cell lymphoma and as a group are not related to these lymphomas. In addition, the prevalence and patterns of c-myc rearrangements in the gastric large-cell lymphomas and ileocecal Burkittlike lymphomas are noteworthy and suggest a different and distinct pathogenesis for these tumors.
N-ras mutations in adult de novo acute myelogenous leukemia: prevalence and clinical significance
Authors: Radich JP , Kopecky KJ , Willman CL , Weick J , Head D , Appelbaum F , Collins SJ 
Published: October 2019

Abstract
Point mutations of the N-ras proto-oncogenes have been previously detected in 20% to 60% of samples of acute myelogenous leukemia (AML), but the clinical significance of these mutations is presently unclear. We directly sequenced polymerase chain reaction (PCR) amplified N-ras fragments to determine the frequency of N-ras point mutations in 55 adult patients with de novo AML. Mutations were present in 8 of 55 (15%) patients. These mutations were usually in codon 12, 13, or 61, but one patient had mutations in both codons 13 and 61, and another had an unusual point mutation in N-ras codon 60. A comparison of patients with and without N-ras mutations showed no statistically significant differences in pretreatment clinical variables, response to induction therapy, or survival, except for a possibly higher percentage of FAB M4 subtypes in patients with the N-ras mutation. These data together with previous reports suggest that the presence of N-ras point mutations do not clearly define a unique clinical or biologic subset of AML patients.
The expression of IgG allotypes on platelets and immunization to IgG allotypes in multitransfused thrombocytopenic patients
Authors: Kickler TS , Ness PM , Braine HG , Richardson L , Farkosh M 
Published: October 2019

Abstract
We investigated whether the platelet-membrane surface carries IgG allotypic antigens and whether these determinants may be important in platelet transfusion therapy. Using a hemagglutination inhibition assay, we showed that the G1m IgG allotypes (a, x, f) and K1m and K3m light-chain allotypes are expressed on the surface of platelets, whereas G3m allotype antigenic determinants were not detectable. In 146 multitransfused thrombocytopenic patients, 35 (24%) patients were found to have antiallotypic antibodies. To study the effect of antiallotypic antibodies on platelet transfusion outcome, patients received platelet transfusions from donors, either positive or negative for the IgG allotype to which patients were immunized. Of the 19 antigen-positive and 19 antigen-negative platelet transfusions given, respectively, the mean platelet count increments at 1 hour were 8,402 +/- 6,402 +/- 6,721 (1 SD) and 9,799 +/- 5,559 (1 SD) P less than .2. Transfusion reactions were not more common when antigen-positive platelet transfusions were given. Despite the presence of IgG allotypic determinants on platelets, allotypic antibodies do not decrease platelet transfusion recovery. Furthermore, passive administration of plasma containing IgG allotypes to patients with antiallotypic antibodies does not lead to innocent bystander-mediated platelet destruction.
Impaired erythrocyte methemoglobin reduction in sickle cell disease: dependence of methemoglobin reduction on reduced nicotinamide adenine dinucleotide content
Authors: Zerez CR , Lachant NA , Tanaka KR 
Published: October 2019

Abstract
We have examined aspects of methemoglobin (metHb) reduction in sickle and in thalassemic red blood cells (RBCs). NADH metHb reductase activity in sickle and thalassemic RBCs was significantly increased compared with normal RBCs. Because in vitro enzyme activity does not necessarily represent in vivo activity, we measured the rate of metHb reduction in intact RBCs. Intact thalassemic RBCs demonstrated a significantly increased rate of metHb reduction compared with normal RBCs. In contrast, intact sickle RBCs had a rate of metHb reduction that was similar to normal RBCs and significantly decreased relative to high reticulocyte RBCs of equivalent cell age. To determine the mechanism for the relative impairment of metHb reduction in sickle RBCs, we measured intraerythrocytic NADH, a cofactor in the metHb reduction reaction. Thalassemic RBCs had a significantly increased NADH content relative to normal RBCs. In contrast, sickle RBCs did not have an increase in NADH content. Furthermore, incubating normal RBCs under conditions that increase the NADH content resulted in an increased rate of metHb reduction. In contrast, conditions that decrease the NADH content in normal RBC resulted in a decreased rate of metHb reduction. These data and other results suggest that metHb reduction in intact RBCs is dependent on NADH content, and that the impaired metHb reduction rate in sickle RBCs may be a result of a lack of increase in NADH content. The dependence of metHb reduction on RBC NADH content and the ability to manipulate NADH content in vitro suggest a new strategy for decreasing oxidant damage to sickle RBCs in vivo.
Phosphatidylserine transport in Rhnull erythrocytes
Authors: Smith RE , Daleke DL 
Published: October 2019

Abstract
Phosphatidylserine transport in normal and Rhnull red blood cells was determined by measuring characteristic morphologic changes induced by synthetic phospholipids. Treating normal A+ cells with commercial anti- A antisera, anti-Rho(D) antisera, or with saturating concentrations of purified Rho(D) antibodies had no effect on phosphatidylserine transport. Normal B- cells treated with purified anti-B antibodies transported phosphatidylserine at rates equal to those of cells not treated with antibody. Rhnull cells, deficient in the protein bearing the Rho(D) antigen, incorporated dimyristoylphosphatidylcholine and dimyristoylphosphatidylserine at rates and to extents similar to normal cells. Furthermore, incorporated phosphatidylserine, but not phosphatidylcholine, was rapidly transported across the membrane bilayer. Energy depletion or treatment with sulfhydryl reagents inhibited phosphatidylserine transport equally in normal and Rhnull cells. These results indicate that, although Rhnull cells have numerous membrane defects, they are capable of adenosine triphosphate-dependent transport of exogenously added dimyristoylphosphatidylserine. Normal phosphatidylserine transport in the presence of anti-Rho(D) antibodies or in cells deficient in the Rho(D) polypeptide indicates that this protein is not the aminophospholipid transporter.
Variations of fat tissue fraction in abnormal human bone marrow depend both on size and number of adipocytes: a stereologic study
Authors: Rozman C , Reverter JC , Feliu E , Berga L , Rozman M , Climent C 
Published: October 2019

Abstract
Studies dealing with the number or size of individual adipose cells in abnormal human bone marrow are lacking. To ascertain whether variations in fat tissue fraction depend on the size of individual adipocytes or their number or both, a stereologic study of 30 human bone marrow specimens (10 with aplasia, 10 with hyperplasia, and 10 with dysplasia) was performed. A total of 23,435 adipocyte profiles were measured and two stereologic parameters were obtained in each specimen: mean diameter and number of cells per mm3 of bone marrow. The fat tissue fraction correlated positively with the size (r = .79; P less than .001) and the number/volume (r = .77; P less than .001) of adipocytes. The significance of both adipocyte size and adipocyte number/volume was confirmed by stepwise multiple regression, in which the size alone explained 62.5% of fat tissue fraction and both size and number/volume explained 95.8% of fat tissue fraction. These results are discussed from a pathophysiologic point of view.
B-ly-7, a monoclonal antibody reactive with hairy cell leukemia, also defines an activation antigen on normal CD8+ T cells [see comments]
Authors: Mulligan SP , Travade P , Matutes E , Dearden C , Visser L , Poppema S , Catovsky D 
Published: October 2019

Abstract
We undertook a study to determine the specificity of the monoclonal antibody, B-ly-7, for hairy cell leukemia (HCL) by examining the expression in 150 samples from B-cell lymphoproliferative diseases as well as screening for reactivity in a number of other hematologic malignancies. Within the B-cell lineage we found that the expression of B-ly-7 was highly specific for HCL and reacted with all 28 cases examined, as well as with 3 of 9 cases of a variant form of HCL. Cells of other closely related B-cell disorders, prolymphocytic leukemia, and splenic lymphoma with villous lymphocytes were negative. Investigation of the peripheral blood and bone marrow of patients with HCL before and after treatment with alpha-interferon or deoxycoformycin suggests that B-ly-7 may be useful in the assessment of minimal disease after therapy. In addition to HCL, we found that B-ly-7 was positive with cells of three mature, CD4+ T-cell malignancies. In view of the reactivity with malignancies of activated B and T cells, we searched for the expression of B-ly-7 on activated, normal B and T cells and found that B-ly-7 reacted specifically with activated normal peripheral blood CD8+ T cells. B-ly-7 has a number of applications, including the precise classification of mature B-cell neoplasia and the diagnosis HCL and its assessment after treatment. In addition, B-ly-7 recognizes a small subset of T-cell disorders. Its expression on these malignancies and on in vitro activated peripheral blood CD8+ T cells suggests that B- ly-7 detects a lymphocyte activation antigen.