bluuebunny/crossref_metadata_2025_split huggingface dataset:
Erythroid Fc-IgG and complement receptor expression: a study of normoblastic and megaloblastic human bone marrows
Authors: Bynoe AG , Scott CS , Roberts BE 
Published: October 2019

Abstract
Using a standardized rosetting technique with IgG-coated ox erythrocytes, avid IgG (Fc) receptors were demonstrated on red cell precursors. The proportion of receptor-positive cells in normal marrows was highest in early precursors and appeared to be lost with maturation. In megaloblastosis, the absolute percentage of early precursors increase, but there is an even greater increase in the proportion of receptor-positive cells. It is proposed that this reflects the degree of maturation arrest. The specificity of the receptor was confirmed by inhibition studies with aggregated human IgG. In contrast, the expression of the C3b “immune adherence” receptor, assessed by IgM-C3b-coated ox erythrocytes, was seen to increase with erythroid maturation. Early megaloblasts, especially in severe megaloblastosis, showed a marked decrease in C3b receptor activity, again in proportion to the level of maturation arrest. The significance and possible function of these receptors is discussed.
Hemin enhances the in vitro growth of primitive erythroid progenitor cells
Authors: Monette FC , Holden SA 
Published: October 2019

Abstract
Since exogenous hemin has been shown to exert a variety of stimulatory effects on erythroid cells, including the augmentation of hemoglobin synthesis, we determined its effect on early stages of erythroid development by employing clonal cells assays. The addition of hemin at a concentration of 2 X 10(-4) M to cultures of normal murine marrow substantially increased the observed number of primitive BFU-E, which was in contrast to its lack of an effect on more mature erythroid colony-forming cells. This cell-specific enhancement of primitive BFU-E resulted in marrow frequencies equivalent to or exceeding those reported in the presence of “burst-promoting activity.” In the presence of hemin, the number of BFU-E was also observed to be linearly related to the number of cells plated at very low plating densities, and the cell titration curve was observed to extrapolate to the origin. The evidence suggests that hemin may be a primary growth regulator of early developmental stages of erythroid progenitor cells.
Thrombin-mediated release of factor VIII antigen from human umbilical vein endothelial cells in culture
Authors: Levine JD , Harlan JM , Harker LA , Joseph ML , Counts RB 
Published: October 2019

Abstract
We have examined the effects of purified human alpha-thrombin on factor VIII antigen (FVIII-Ag) release by human umbilical vein endothelial cells in culture. Alpha-thrombin induced a time and dose-dependent release of FVIII-Ag into supernatant medium. Alpha-thrombin-mediated FVIII-Ag release was not dependent on protein synthesis and was observed in both serum-free and serum-containing media. FVIII-Ag release, however, was prevented when the serine esterase activity of thrombin was inhibited. Pretreatment of human endothelial cells with alpha-thrombin, but not diisofluorophosphate-thrombin, prevented subsequent FVIII-Ag release by alpha-thrombin. Thrombin-mediated FVII- Ag release was not associated with significant 51Cr release from prelabeled endothelial monolayers. We conclude that alpha-thrombin induces release of preformed FVIII-Ag from human umbilical vein endothelial cells by a receptor-independent, nonlytic mechanism requiring serine esterase activity.
Fibronectin: blood turnover in normal animals and during intravascular coagulation
Authors: Sherman LA , Lee J 
Published: October 2019

Abstract
Plasma fibronectin (FN) binds fibrin in vitro by both noncovalent and covalent bonds and is decreased in DIC. In rabbits, conventionally purified 125I-FN had a complex blood clearance with a late t1/2 of 71 hr. A large portion was apparently altered, as evinced by rapid clearance and an intravascular/total body ratio (C1) of 0.28–0.51. 3H- labeled FN, made in vivo by injection of 3H amino acids, had a t1/2 of 73 hr. Crosstransfusion of 131I-FN and 3H-FN into a second set of animals gave similar t1/2s and C1s of 0.74–0.82, indicating the altered 125I-FN was biologically screened in the first animals. Other animals were given 125I-fibrinogen and “screened” 131I-FN. Intravenous thrombin (50–60 U/kg/1 hr) caused a 25%-50% decrease in both 125I-fibrinogen and 131I-FN. Ancrod injection reduced fibrinogen by greater than 90% but had no effect on 131I-FN. 131I-FN levels did not change when thrombin was given after ancrod. No cross-linked FN-fibrinogen alpha-chain was found in the plasma, nor was the thrombin-induced fall in FN affected by spermidine blockade. These experiments demonstrate that FN and fibrin bind in vivo during defibrination and are rapidly cleared from the blood. The abnormal fibrin resulting from ancrod either does not bind FN in vivo or does so reversibly.
Characterization of the colony-forming cell in monoclonal gammopathies
Authors: Bast BJ , Boom SE , Ballieux RE 
Published: October 2019

Abstract
The nature of the colony-forming cell in the bone marrow of patients with monoclonal gammopathy, as defined in the stem cell assay described by Hamburger and Salmon, has been studied. It could be shown that the colony-forming cells produce immunoglobulins of the same idiotype, heavy chain and light chain, as the monoclonal bone marrow cells in the patient. Data regarding the presence or absence of J chain in the colonies, the failure to observe isotype-switch in the growing colonies, as well as the lack of inhibition of colony formation using antiidiotypic antibodies, strongly suggest that colony formation in vitro reflects proliferation of the clonogenic stem cell in the bone marrow without apparent differentiation. The stem cell may be of plasma cell nature.
IMVP-16: an effective regimen for patients with lymphoma who have relapsed after initial combination chemotherapy
Authors: Cabanillas F , Hagemeister FB , Bodey GP , Freireich EJ 
Published: October 2019

Abstract
Results of second-line chemotherapy regimens against lymphoma have usually been poor. In this study, we used a combination of ifosfamide, methotrexate, and VP-16 to treat 52 patients with lymphoma who had either relapsed or who had failed to attain a complete remission on front-line treatment. Thirty-two patients (62%) responded (CR 37%, PR 25%) and 10 (19%) had a minor response. The median relapse-free interval of the responding patients was 12 mo, and the median survival of the whole group was 15 mo. Of the 18 patients who achieved complete remission, 10 still remain free of any evidence of disease. The factor that best predicted for response to IMVP-16 was the quality of the remission achieved on front-line therapy. In view of the poor prognosis associated with recurrent lymphoma, the results obtained with this study are considered most encouraging. Patients with recurrent lymphoma can be successfully salvaged by the use of this combination regimen, especially if introduced early after relapse or preferably before progressive disease develops.
Changes in cell surface antigen expression during hemopoietic differentiation
Authors: Sieff C , Bicknell D , Caine G , Robinson J , Lam G , Greaves MF 
Published: October 2019

Abstract
Human bone marrow cells were separated on a fluorescence activated cell sorter (FACS) according to their binding of a series of monoclonal antibodies; the positive and negative fractions were cloned for erythroid burst and colony-forming units (BFU-E and CFU-E) and myeloid colony-forming units (CFU-GM), and cytocentrifuge slides were prepared for microscopy of maturing precursors. The pattern of antigen expression on hemopoietic progenitor and precursor populations has been established using antibodies defining blood group (A, I/i), HLA- associated (*A, B, C, DR, DC1), lineage specific, and transferrin receptor antigens. Like monomorphic HLA-DR, the antigen defined by monoclonal antibody OKT10 is expressed on the earliest progenitors and lost during differentiation, suggesting a role in interactions regulating the differentiation of these cells. The HLA-linked DC1 determinant, in contrast to HLA-DR, is not expressed at a detectable level on progenitor cells. Although a lineage-specific early antigen has not been identified, the transferrin receptor is expressed on the majority of erythroid progenitors, but only weakly on myeloid progenitors, and may provide an approach to isolating erythroid progenitors. These and earlier studies with monoclonal antibodies against HLA-DR and glycophorin now provide a detailed “map” of antigen expression during hemopoietic differentiation.
Constitutive expression of platelet glycoproteins by the human leukemia cell line K562
Authors: Gewirtz AM , Burger D , Rado TA , Benz EJ Jr , Hoffman R 
Published: October 2019

Abstract
The human leukemia cell line K562 was derived from a patient with chronic granulocytic leukemia. This cell line has subsequently been shown to possess phenotypic markers typical of erythroid and myeloid cells. Using a rabbit antiserum directed against purified platelet glycoproteins (PGPs), we have obtained evidence for the constitutive expression of PGPs on the surface of K562 cells. PGPs expressed have been tentatively identified as IIa and III based on their apparent migration in a 7% sodium dodecylsulfate polyacrylamide gel. K562 may become an important tool for the study of early events involved in megakaryocytic differentiation.
The production of committed hemopoietic colony-forming cells from multipotential precursor cells in vitro
Authors: Nicola NA , Johnson GR 
Published: October 2019

Abstract
Murine fetal liver cells have been fractionated by fluorescence- activated cell sorting into two fractions termed. For convenience, the pre-CFC and CFC (colony-forming cell) fractions, which differ in their relative binding of the lectin, pokeweed mitogen. The CFC fraction contained a high frequency of CFC (26%) and in liquid cultures stimulated with colony-stimulating factors generated large numbers of differentiated progeny. Consequently, residual CFC could not be detected in such cultures after day 4. In contrast, the pre-CFC fraction contained relatively few CFC (1%) but contained the majority of CFU-S and was able to generate large numbers of new CFC after 5–7 days in liquid culture. This production of CFC from precursor cells was absolutely dependent on factors present in pokeweed-mitogen-stimulated spleen cell conditioned medium (PWM-SCM) or postendotoxin serum (ES) but was not stimulated by known granulocyte or macrophage colony- stimulating factors. CFC production occurred from multipotential precursor cells and all types of CFC were detected (excluding lymphocytes). Clonal analysis of pre-CFC showed that most of the generated CFC arose from relatively few multipotential precursors some of which could generate up to 500 CFC. The data suggested a differentiation sequence of the multipotential precursor cells in which differentiation potentials are successively restricted in the order macrophage, eosinophil, granulocyte-macrophage leads to granulocyte, megakaryocyte, erythroid. The frequency of CFC-generating cells in the pre-CFC fraction was significantly less (ten-fold) than that of CFU-S, suggesting that pre-CFC may be a more ancestral subset of CFU-S. The cell fractions and assay systems described should be of use in defining and purifying factors regulating early phases of hemopoietic differentiation and in defining the differentiation steps involved in the restriction of potentialities of multipotential cells.
Isolation of human platelet membrane microparticles from plasma and serum
Authors: George JN , Thoi LL , McManus LM , Reimann TA 
Published: October 2019

Abstract
Methods have been developed to isolate human platelet membrane fragments from plasma and serum. Rabbit antibody produced against the human platelet membrane glycoprotein complex, IIb/IIIa, was utilized in an immunoelectrophoretic assay to evaluate the amount of this antigen in various microparticle preparations. The serum concentration of platelet microparticles was more than tenfold greater than that observed for plasma (65 micrograms/ml versus 4.4 micrograms/ml, respectively). Ultrastructural evaluation of either plasma or serum- derived microparticles disclosed a variety of membrane fragments and membrane-bound vesicles with occasional fragments of red blood cells, white blood cells, and platelets. In contrast, microparticle preparations derived from isolated washed platelets after thrombin stimulation contained a heterogeneous array of membrane fragments, vesicles, and granules but no identifiable red cell, white cell, or platelet fragments. Thus, these studies demonstrate that normal human plasma and serum contain platelet membrane fragments that are produced during cell activation. If a similar loss of platelet membranes occurs in vivo following reversible platelet activation, it is possible that the resulting membrane modifications may be of importance in both the structural and functional changes that develop during platelet senescence.
Equivalence of intrathecal chemotherapy and radiotherapy as central nervous system prophylaxis in children with acute lymphatic leukemia: a pediatric oncology group study
Authors: Sullivan MP , Chen T , Dyment PG , Hvizdala E , Steuber CP 
Published: October 2019

Abstract
The efficacy of intrathecal (i.t.) chemoprophylaxis was compared with cranial radiotherapy plus i.t. methotrexate (MTX) in a Southwest Oncology Group (SWOG) study accessing 408 patients from September 10, 1974, to October 29, 1976. Randomization was stratified by prognostic groups (PGs) based on age and white blood cell count at diagnosis. All received induction therapy with vincristine and prednisone (Pred); maintenance therapy consisted of daily 6-mercaptopurine and weekly MTX. Consolidation for arm 1 employed cyclophosphamide and L-asparaginase followed by biweekly 5-day courses of parenteral MTX. The first dose of each course of MTX was given i.t. in triple chemoprophylaxis (MTX, hydrocortisone, and cytosine arabinoside). During maintenance, i.t. chemoprophylaxis was bimonthly and 28-day Pred “pulses” were given every 3 mo. Arm 2 i.t. chemoprophylaxis was initiated on achievement of remission, and arm 3 i.t. on treatment day 1; both continued 1 yr. Arm 4 induction included two doses of L-asparaginase. On achievement of remission, CNS prophylaxis (radiotherapy, 2400 rad plus i.t. MTX) was given. For all, therapy was discontinued after 3 yr of continuous complete remission. Survival and the incidence of extramedullary relapse were similar for the treatments employing either i.t. chemoprophylaxis or radiotherapy plus i.t. MTX upon achievement of remission. Among poor prognosis patients, the duration of complete remission was significantly better with the regimen using i.t. chemoprophylaxis as a component of consolidation therapy than with the regimen employing i.t. chemoprophylaxis early in induction or with the treatment using radiotherapy plus i.t. MTX for CNS prophylaxis. In poor prognosis patients, the initiation of i.t. chemoprophylaxis during consolidation was also associated with hematologic remissions that were significantly better than those achieved with the treatment employing early CNS chemoprophylaxis or with the regimen using radiotherapy plus i.t. MTX. Among average prognosis patients, therapy with CNS chemoprophylaxis during consolidation, as well as the regimen employing radiotherapy and i.t. MTX for CNS prophylaxis, produced hematologic remissions that were significantly longer than those obtained with the regimen using early CNS chemoprophylaxis. Hematologic remissions of good prognosis patients who received treatment with the regimen employing i.t. chemoprophylaxis during consolidation were statistically superior when compared to the regimen employing CNS radiotherapy plus i.t. MTX. This study indicates that i.t. chemoprophylaxis may be substituted for cranial radiotherapy when utilizing effective systemic regimens. Additionally, chemoprophylaxis may be reduced from 3 to 1 yr in patients with good prognostic factors.
Syndrome of neutrophil agranulocytosis, hypogammaglobulinemia, and thymoma
Authors: Degos L , Faille A , Housset M , Boumsell L , Rabian C , Parames T 
Published: October 2019

Abstract
The clinical, hematologic, and immunologic findings of a syndrome of agranulocytosis, hypogammaglobulinemia, and thymoma are described. Neutrophil agranulocytosis predisposing to severe infectious disease resulted from a deficiency of mature cells in bone marrow. Autologous and heterologous stem cell growth in vitro was inhibited by the patient's serum. Immunoglobulin deficiency was secondary to the absence of peripheral blood B lymphocytes, while T-cell subpopulations and cellular immunity were present. Surgical removal of a spindle cell thymoma had no effect on the agranulocytosis and B-cell deficiency. The hematologic findings did not respond to steroid therapy and cyclophosphamide. However, the agranulocytosis improved with repeated plasmapheresis and the patient achieved a clinical remission.
The subcellular particulate NADPH-dependent O2.(-)-generating oxidase from human blood monocytes: comparison to the neutrophil system
Authors: Chaudhry AN , Santinga JT , Gabig TG 
Published: October 2019

Abstract
Highly purified preparations of normal human monocytes obtained from peripheral blood were shown to contain a subcellular particulate O2.(-)- generating oxidase system. This O2.(-)-generating activity was present in particulate preparations from monocytes that had been previously stimulated with phorbol myristate acetate but was low or absent in control preparations from unstimulated monocytes or stimulated monocytes from a patient with chronic granulomatous disease. In the stimulated preparations from normal monocytes, O2.(-)-generation was linearly proportional to cell protein concentration, insensitive to inhibition by azide, and dependent on NADPH as substrate. These characteristics are similar to the O2.(-)-generating oxidase system from human neutrophils. A significant difference in the apparent Km for NADPH was shown between preparations from stimulated monocytes and neutrophils (monocyte 83 +/- 16 microM, neutrophil 31 +/- 5 microM, mean +/- SE). Additionally, affinity of the stimulated monocyte particulate preparation for NADH was unmeasurably low.
Evaluation of erythropoiesis in long-term hamster bone marrow suspension cultures: absence of a requirement for adherent monolayer cells
Authors: Eastment CE , Ruscetti FW 
Published: October 2019

Abstract
In long-term hamster bone marrow cultures, proliferation and differentiation of hemopoietic stem cells occurs for several months without need for hydrocortisone or adherent stromal elements, which are requirements for bone marrow growth in all other species studied. Only the most primitive erythroid progenitors (BFU-E) are produced in the cultures. Following treatment of the cells with erythropoietin, these progenitor cells undergo differentiation into mature hemoglobinized red blood cells. Concomitant addition of erythropoietin (Epo) and prostaglandin-E1 (PGE1) results in the production of large numbers of maturing red blood cells. In cultures stimulated with Epo and PGE1, as many as 70% of the cells are benzidine-positive, while Epo alone stimulated as many as 45% of the cells to become erythroid. Epo and PGE1 do not have any apparent deleterious effect on the continuous hemopoiesis occurring in these cultures. Under identical conditions, syngeneic adherent cell cultures do not produce any erythroid elements. The development of mature red blood cells from primitive erythroid precursors occurs in the presence of Epo alone and without any apparent need for adherent stromal elements. These cultures provide a useful in vitro model for dissecting the positive and negative signals that regulate erythropoiesis.
Heterogeneity of the response of chronic lymphocytic leukemia cells to phorbol ester
Authors: Okamura J , Gelfand EW , Letarte M 
Published: October 2019

Abstract
The ability of the tumor promotor 12–0-tetradecanoylphorbol 13-acetate (TPA) to induce differentiation of leukemic cells was studied in 10 cases of chronic lymphocytic leukemia (CLL). An increase in modal volume and an enhancement of the capacity of te leukemic cells to stimulate in mixed lymphocyte reaction (MLR) was seen in the majority of cases. A significant increase in Ia expression was observed upon culture of leukemic cells with TPA in 6 of the 10 cases; 5 of these cases also showed an induction of cytoplasmic IgM production. Correlations between the phenotypic markers of the leukemic cells and their ability to respond to TPA were evaluated. CLL cells with low amounts to surface Ig. a volume less than or equal to 165 fl. and relatively low la expression responded well to TPA. Cells with bright surface Ig. a volume greater than or equal to 178 fl. and elevated amounts of Ia responded poorly to TPA. These results suggest that differences in the response of B leukemic cells to TPA reflect the underlying heterogeneity of the leukemic cells and might be correlated with their stage of maturation.
Aspirin prolongation of the template bleeding time: influence of venostasis and direction of incision
Authors: Mielke CH Jr 
Published: October 2019

Abstract
The template bleeding time is a measure of platelet participation in primary hemostasis. Aspirin alters platelet function through interference with prostaglandin biosynthesis. In many individuals, aspirin will consistently prolong the bleeding time. Despite this observation, normal individuals rarely develop a bleeding disorder. This prompted us to investigate the influence of technical variables on the prolongation of the bleeding time by aspirin. Both direction of incision and venostasis influenced the prolongation of the bleeding time by aspirin. A horizontal incision with venostasis produced the most pronounced prolongation, while a vertical incision without venostasis didn't prolong the bleeding time despite the characteristic changes in platelet aggregation and release. These studies suggest that the influence of aspirin on the template bleeding time is dependent on technical variables and is minimal in the normal subject.
Monocyte function in patients with chronic granulomatous disease of childhood
Authors: Donowitz GR , Mandell GL 
Published: October 2019

Abstract
Adults with chronic granulomatous disease of childhood (CGD) have been described who remain relatively free of infection despite markedly abnormal neutrophil function. Monocyte function in four adults with this mild or atypical CGD syndrome was examined and compared to that of normal controls and to that of two patients with the more severe or classic CGD syndrome. Monocytes from patients with atypical CGD killed 75.7% +/- 2.6% (mean +/- SEM) of ingested organisms at 30 min, while monocytes from the patients with classic CGD killed only 50.3% +/- 4.2% of bacteria (p less than 0.001). The difference in bactericidal activity between atypical CGD monocytes and normal monocytes was relatively small (75.7% +/- 2.6% versus 88.1% +/- 3.7%, respectively) but was statistically significant (p = 0.007). Monocytes from both atypical and classic CGD patients showed markedly impaired oxidative metabolism. Differences in monocyte bactericidal activity may explain why atypical CGD patients have fewer infections than classic CGD patients. The presence of nonoxidative bactericidal mechanisms in atypical CGD monocytes is suggested by the demonstration of bactericidal activity despite severe oxidative metabolic defects.