bluuebunny/crossref_metadata_2025 huggingface dataset:
Blood cells participate in the fibrinolytic response to tissue-type plasminogen activator
Authors: Hammouda MW , Moroz LA
Published: October 2019

Exercise and venous occlusion stimulate fibrinolysis. In addition to increased concentrations of tissue-type plasminogen activator (tPA) and increased plasmin-mediated fibrinolysis in plasma, these stimuli produce additional cellular-phase activity in blood that is of the same magnitude as the plasma response. To determine whether tPA alone, rather than other consequences of these stimuli, is responsible for the cellular response, the in vitro effects of tPA on whole blood, plasma, and calculated cellular-phase (whole blood minus plasma) activities were determined by solid-phase radiofibrin assay on venous blood from ten normal subjects (seven men, three women). At tPA concentrations encompassing physiological and therapeutic levels (5 to 100 ng/mL; 0.7 to 14 IU/mL), increments in whole blood were consistently in excess of those in companion plasma and represented increased cellular-phase activity equivalent in magnitude to the well-known increase in plasma activity. Fibrinolytic activity produced by 10 to 20 ng tPA/mL (1.4 to 2.8 IU/mL) was consistently detected in whole blood and plasma by 60 minutes, with higher concentrations (100 ng or 14 IU tPA/mL) detectable after a five-minute assay in all subjects. Thus, tPA alone, without invoking fibrinolytic factors extraneous to blood or other effects of exercise or venous occlusion, accounts for both cellular and plasma responses to these stimuli. The considerable cellular response, the mechanism of which remains to be elucidated, may constitute a determinant of individual therapeutic responsiveness to tPA.
Deoxycytidine preferentially protects normal versus leukemic myeloid progenitor cells from cytosine arabinoside-mediated cytotoxicity
Authors: Bhalla K , MacLaughlin W , Cole J , Arlin Z , Baker M , Graham G , Grant S
Published: October 2019

We examined the ability of high concentrations of the naturally occurring nucleoside deoxycytidine (dCyd) to reverse the cytotoxicity of high (eg, greater than or equal to 10(-5) mol/L) concentrations of 1- B-D arabinofuranosylcytosine (Ara-C) toward normal (CFU-GM) and leukemic myeloid progenitor cells (L-CFU). Leukemic myeloblasts from patients with acute nonlymphocytic leukemia (ANLL) and normal human bone marrow mononuclear cells were cultured in soft agar in the continuous presence of 10(-5) to 5 X 10(-5) mol/L of Ara-C together with dCyd (10(-4) to 5 X 10(-3) mol/L). Administration of 10(-5) mol/L of Ara-C alone eradicated colony formation in all samples tested. Coadministration of 10(-3) mol/L of dCyd restored 72.2% of control colony formation for CFU-GM, but only 10.9% for L-CFU. When higher concentrations of Ara-C (eg, 5 X 10(-5) mol/L) were administered, dCyd- mediated protection toward CFU-GM decreased, but remained significantly greater than that observed for L-CFU. Incubation with 10(-3) mol/L of dCyd reduced the 4-hour intracellular accumulation of the triphosphate derivative of Ara-C (Ara-CTP) in both normal and leukemic cells by greater than 98%; under identical conditions, a significant expansion of the intracellular of the triphosphate derivative of dCyd (dCTP) pools was observed in normal bone marrow mononuclear cells but not in leukemic blasts. This finding was associated with a greater reduction in Ara-C DNA incorporation in normal elements. These in vitro studies suggest that dCyd may preferentially protect normal v leukemic myeloid progenitor cells from the lethal actions of high-dose Ara-C.
Bipotential cell differentiation of KU-812: evidence of a hybrid cell line that differentiates into basophils and macrophage-like cells
Authors: Fukuda T , Kishi K , Ohnishi Y , Shibata A
Published: October 2019

KU-812-F is a subclone of KU-812, which has cytological features similar to the parent clone, and which carries the Philadelphia chromosome. We studied the effects of various chemical agents and serum- free culture (SF-C) condition on its differentiation. The KU-812-F subclone differentiated into macrophage-like cells with phorbol myristate acetate (PMA), but not with other agents. Unexpectedly, under SF-C, KU-812-F cells differentiated into mature basophil-like cells, and the histamine content of cell lysates increased in proportion to maturation. The addition of the condensed supernatant of SF-C promoted the cloning efficiency of KU-812-F cells in semisolid SF-C, whereas the cloning efficiency was reduced in SF-C alone. KU-812-F cells expressed myelomonocytic antigens. Additionally, My4 was induced with PMA and SF- C, but less often. HLA-DR was not expressed in any culture conditions, despite blastic morphology of KU-812-F cells or macrophage-like cells induced with PMA. The IgE receptor could not be demonstrated under any conditions. Correspondingly, immature and mature KU-812-F cells did not respond to anti-IgE or concanavalin A (con A), while histamine release was induced with PMA. In conclusion, KU-812-F belongs to the myeloid cell lineage and is at least a bipotential cell that can differentiate into basophils and macrophage-like cells. Although the functions appear to be dissimilar to those of normal basophils, the KU-812-F cell line may be a good model for basophil differentiation. Moreover, KU-812-F cells may provide new insights because they grow in semisolid culture by an autostimulating mechanism.
The effects of three recombinant growth factors, IL-3, GM-CSF, and G- CSF, on the blast cells of acute myeloblastic leukemia maintained in short-term suspension culture
Authors: Miyauchi J , Kelleher CA , Yang YC , Wong GG , Clark SC , Minden MD , Minkin S , McCulloch EA
Published: October 2019

The blast stem cells of acute myeloblastic leukemia (AML) respond in cell culture to growth factors by both self-renewal and terminal divisions. Both of these functions have been shown to be stimulated by the recombinant growth factors granulocyte-macrophage colony- stimulating factor (GM-CSF) and granulocyte colony-stimulating factor (G-CSF). In this paper, recombinant gibbon interleukin-3 (IL-3), homologous to human IL-3, was tested on blast cells and compared with the effects of GM-CSF, G-CSF, and medium conditioned by the bladder cell line 5637 (5637-CM). We found that IL-3 was an effective stimulator of blast renewal and terminal divisions. However, great patient-to-patient variation was found. A graphic method of presenting complex comparisons between growth factors is also included.
Abnormal stimulated adherence of neonatal granulocytes: impaired induction of surface Mac-1 by chemotactic factors or secretagogues
Authors: Anderson DC , Freeman KL , Heerdt B , Hughes BJ , Jack RM , Smith CW
Published: October 2019

To identify possible secretory determinants of impaired hyperadherence and stimulated migration of neonatal granulocytes (NGs), we performed correlative studies of: (a) specific granule content and exocytosis, (b) secretago-gue-mediated upregulation of f-met-leu-phe (fMLP) receptors, (c) the chemotactic induction of the adhesive glycoproteins Mac-1 alpha (complement receptor 3) and beta, and (d) morphometric assessments of specific (peroxidase negative) granule depletion following chemotactic stimulation. Lactoferrin (LF) content of NG suspensions (cord blood or peripheral blood cells) was profoundly diminished (mean +/- SD 51% +/- 18% of normal) as compared with healthy adult granulocytes (AGs). Despite diminished cellular content, LF release by NG suspensions in response to fMLP was comparable to that of AGs. In contrast, LF release by NG suspensions was significantly diminished in response to phorbol myristate acetate (PMA) or calcium ionophor A23187 and/or during stimulated cell spreading, experimental conditions promoting overall greater LF depletion than chemotactic stimuli. In addition, NGs demonstrated an impaired capacity to upregulate fMLP receptors in response to PMA or A23187 when tested under the same experimental conditions. Baseline expression of the adhesive glycoproteins Mac-1 alpha and beta on NG surfaces was normal, but induction or upregulation of these proteins by chemotactic concentrations of fMLP, C5a as well as secretory (high) concentrations of PMA and A23187, was significantly diminished as compared with AGs. In contrast, chemotactic induction of the surface expression of the complement receptor-1 (CR-1) on NGs was normal. An impaired induction of Mac-1 alpha or beta was directly related to an impaired enhancement of adherence of NG in response to fMLP over a chemotactically relevant concentration range (10(-10) to 10(-7) mol/L). Moreover, in blocking- incubation experiments using anti-Mac-1 alpha/beta monoclonal antibodies (MAbs), significantly less inhibition of adherence by these MAbs was evident with fMLP-stimulated NG as compared with AG suspensions. Under selected chemotactic conditions, ultrastructural assessments of NGs demonstrated diminished peroxidase-negative granule loss in association with diminished granule-membrane fusion and the “addition” of plasma membrane. These studies suggest that abnormal expression of multiple surface determinants derived from peroxidase- negative granules or other intracellular pools may contribute to deficient chemotaxis or other inflammatory functions of NGs.(ABSTRACT TRUNCATED AT 400 WORDS)
Direct evidence for the interaction of the nucleotide affinity analog 5'-p-fluorosulfonylbenzoyl adenosine with a platelet ADP receptor
Authors: Figures WR , Scearce LM , DeFeo P , Stewart G , Zhou F , Chen J , Daniel J , Colman RF , Colman RW
Published: October 2019

Previous reports have indicated that the nucleotide affinity analog 5′- p-fluorosulfonylbenzoyl adenosine (FSBA) at concentrations between 40 and 100 mumol/L and at times greater than 20 minutes covalently modifies a single protein component on the external platelet membrane surface and that adenosine diphosphate (ADP) protects against this reaction. That this protein is an ADP receptor linked to platelet activation is shown by FSBA inhibition of ADP-mediated platelet shape change, aggregation, and fibrinogen receptor exposure. In this report, further evidence for the interaction of FSBA with the ADP receptor on platelets is provided by the observation that FSBA at high concentrations (100 to 500 mumol/L) behaves as a weak agonist to produce platelet shape change within one minute as detected by spectroscopic assay and scanning electron microscopy with concomitant phosphorylation of the light chain of platelet myosin. The specificity of FSBA as an agonist is demonstrated by inhibition of FSBA-induced shape change by ATP and the covalent incorporation of SBA as well as the failure of 5′-fluorosulfonylbenozoyl guanosine (FSBG) to cause shape change. In contrast, incubation of platelets with low concentrations of [3H]-FSBA (40 mol/L) is not associated with stimulation of platelet shape change or myosin light chain phosphorylation.
A two-color flow cytometry assay for detection of hairy cells using monoclonal antibodies
Authors: Kristensen JS , Ellegaard J , Hokland P
Published: October 2019

We have developed a simple two-color immunofluorescence assay equally suited for microscopy and flow cytometry detecting hairy cells (HCs) in single cell suspensions, based on the concomitant reactivities with the B cell-specific monoclonal antibody B1 (CD20) and the monocyte/HC- associated antibody SHCL-3 (CD11c). Thus, HCs can be demonstrated in peripheral blood, bone marrow, and spleen specimens from hairy cell leukemia (HCL) patients even when they constitute less than 1% of the cell suspension. Likewise, admixture experiments with normal mononuclear cells and the MOLT-4 T-acute lymphocytic leukemia (ALL) cell line demonstrated that HCs could be detected in amounts as low as 1%. The validity of this assay has been ascertained by the lack of double marker positivity in cell suspensions from B-chronic lymphocytic leukemia (CLL) and acute myelogenous leukemia (AML) patients that only expressed B1 or SHCL-3, respectively. Furthermore, other malignant blood diseases, including malignant lymphomas, acute leukemias, and chronic leukemias disclosed no double marker positive cells. In a clinical setting, this assay was used for purifying HCs (by flow cytometry) from the peripheral blood from patients with no apparent morphological evidence of circulating HC infiltration and for monitoring the effect of interferon therapy. In conclusion, this assay should be of value for both diagnosis and monitoring patients with HCL.
Conversion of the active to latent plasminogen activator inhibitor from human endothelial cells
Authors: Levin EG , Santell L
Published: October 2019

The plasminogen activator inhibitor from human endothelial cells (PAI- 1) exists in two forms in the culture medium: an active form that binds to and inactivates plasminogen activators and a latent form that in its native state has no anti-activator activity. Inhibitor activity associated with the latent form can be generated by treatment with protein denaturants and makes up more than 98% of the total inhibitor activity in conditioned medium. Plasminogen activator inhibitor activity is also found in cell cytosol. This inhibitor activity is stable to SDS-treatment but is not enhanced by it. We investigated the relationship between this active cell-associated inhibitor and the latent PAI-1 found in the conditioned medium. Both intracellular and extracellular inhibitors were immunoprecipitated by a monoclonal antibody produced against the latent inhibitor from HT1080 fibrosarcoma cells and electrophoresis on SDS gels of various acrylamide concentrations demonstrated that both forms had the same Mr. Incubation of cytosol inhibitor at 37 degrees C resulted in a decline in inhibitor activity with a half-life of approximately 4 hours, a rate of decline similar to that of the active PAI-1 in conditioned medium, with less than 10% of the original activity present after eight hours. This decline is accelerated at higher temperatures and is not affected by the presence of a variety of protease inhibitors. Approximately 90% of the activity can be regenerated after SDS treatment suggesting that the cell associated inhibitor, during incubation at 37 degrees C, converts to a form similar to that found in conditioned medium. Despite these similarities, the apparent Stoke's radii of the active intracellular inhibitor and the latent inhibitor in conditioned medium were significantly different with values of 2.77 nm and 2.40 nm for active and latent PAI-1, respectively. Incubation of the active form at 37 degrees C resulted in the shift of the Stoke's radius to that similar to the latent PAI-1 (2.45 nm). Thus, the active and latent PAI-1, while being immunologically similar and of the same apparent Mr, can be differentiated by their behavior on gel permeation columns. This suggests that the intracellular inhibitor is a precursor to the latent form.
Functional heterogeneity of B-CLL lymphocytes: dissociated responsiveness to growth factors and distinct requirements for a first activation signal
Authors: Karray S , Merle-Beral H , Vazquez A , Gerard JP , Debre P , Galanaud P
Published: October 2019

We studied the effects of B cell directed growth factors on B lymphocytes from 11 patients with chronic lymphocytic leukemia (B-CLL). B-CLL lymphocytes were costimulated with anti-mu antibody (Ab) and with three growth factor preparations: recombinant IL2, B cell growth factor (BCGF) (20 kiloDalton (kD) BCGF) and a high molecular weight BCGF (50 kD BCGF). IL2 was the more active factor (in six of 11 patients). The effect of IL2 was dependent on a costimulation with anti-mu Ab or occurred independently of anti-mu Ab, according to the patients. This pattern of reactivity did not correlate with the presence or absence of the IL2 receptor (IL2-R) molecule on fresh B-CLL lymphocytes. Five patients responded to the 20 kD BCGF. Although four of them were also strong responders to IL2, one strongly responded to the 20 kD BCGF and did not respond to IL2. Only one patient responded to the 50 kD BCGF. When an anti-IL2-R Ab was introduced into the culture, only the responsiveness to IL2 was abolished: thus both 20 kD and 50 kD BCGFs activate B-CLL lymphocytes independently of the IL2-R. These results show that several B cell directed growth factors can act independently to support the proliferation of B-CLL lymphocytes.
The molecular species composition of phosphatidylcholine affects cellular properties in normal and sickle erythrocytes
Authors: Kuypers FA , Chiu D , Mohandas N , Roelofsen B , Op den Kamp JA , Lubin B
Published: October 2019

The phosphatidylcholine specific transfer protein (PCTP) from bovine liver was used to retailor the molecular species composition of phosphatidylcholine (PC) in the membrane of normal (AA) and sickleable (SS) human erythrocytes. Changes in molecular species composition of PC altered morphology as well as cellular deformability and stability as measured with ektacytometry. In normal cells, replacement of native PC with 1-palmitoyl,2-arachidonoyl PC (PAPC) resulted in a decrease in osmotic fragility with no change in hydration, whereas replacement with 1,2-dipalmitoyl PC (DPPC) led to an increased osmotic fragility and cellular hydration. Replacement of native PC by 1-palmitoyl,2-oleoyl PC (POPC) in normal cells had no apparent effect on these parameters. In contrast, replacement of native PC in sickle cells with either PAPC, DPPC or POPC led to cellular hydration. Facilitation of PC exchange between subpopulations of SS cells separated on buoyant density also led to cellular hydration. These observations suggest that the state of hydration of sickle cells can be modified by the fatty acyl composition of PC and illustrate a a role for the lipid core in the observed permeability changes in sickle erythrocytes. They also raise the interesting possibility that the state of cellular hydration of sickle cells may be modulated by altering the molecular species composition of the membrane phospholipids.
Progenitor cell assays predict hematopoietic reconstitution after syngeneic transplantation in mice
Authors: Jones RJ , Sharkis SJ , Celano P , Colvin OM , Rowley SD , Sensenbrenner LL
Published: October 2019

Hematopoietic reconstitution following syngeneic bone marrow transplantation with graded doses of untreated and drug-treated bone marrow was studied in B6D2F1 mice. Granulocyte-macrophage colony- forming units (CFU-GM) and spleen colony-forming units (CFU-S) showed similar in vitro drug sensitivities. Both the speed of hematologic recovery and survival of mice transplanted with untreated or drug- treated bone marrow were directly related to the number of CFU-GM or CFU-S transplanted. Similar hematologic recovery was seen for untreated marrow transplants and treated transplants that had similar CFU-GM or CFU-S content. There is a minimum number of transplanted CFU-GM or CFU- S that allows survival of lethally irradiated mice. This number is present in a marrow transplant containing the equivalent of 5 X 10(3) untreated cells or producing one to two spleen colonies. There also exists a maximum value for the number of hematopoietic progenitors in a marrow graft, above which the rate of hematologic recovery following transplantation is rapid and no detectable increase in the rate is seen with increasing CFU-GM or CFU-S content. The presence of this maximum value for transplanted progenitors and variations in culture techniques are probably the reasons previous studies have not always shown a correlation between CFU-GM content and hematologic recovery after bone marrow transplantation.
Fructose-6-phosphate,2-kinase activity in human erythrocytes
Authors: Fujii S , Matsuda M , Okuya S , Yoshizaki Y , Miura-Kora Y , Kaneko T
Published: October 2019

The hemolysate partially purified from human red cells was demonstrated to be capable of synthesizing fructose-2,6-bisphosphate (F-2,6-P2) from fructose-6-phosphate in the presence of adenosine triphosphate (ATP) indicating that human red cells contain fructose-6-phosphate,2-kinase. The effect of F-2,6-P2 on the rate-limiting enzymes of glycolysis, ie, hexokinase, phosphofructokinase (PFK), and pyruvate kinase, has also been examined. PFK was activated by this metabolite and the half- maximum activation was obtained at a concentration of 10(-7) mol/L. Neither hexokinase nor pyruvate kinase was affected by F-2,6-P2. These results suggest that human erythrocytes may contain this metabolite as one of the positive effectors for PFK.
Characterization of interleukin-2 receptors expressed on acute leukemic B cells
Authors: Bentaboulet M , Allouche M , Tsapis A , Jasmin C , Georgoulias V
Published: October 2019

More than 90% of both unfractionated and blast-enriched T cell-depleted mononuclear cells (MNC) from a patient with a morphologically and phenotypically unclassified acute leukemia expressed interleukin 2 receptors (IL2-R), whereas 50% unfractionated MNC displayed monocyte/myeloid- (My7, My9, and OKM1) and B cell-restricted (B4) antigens. Two-color fluorescence studies showed that 80% of the My9+ cells expressed the B4 antigen and 63% of the B4+ cells were IL2-R+. Cell incubation with phorbol myristate acetate (PMA) increased the expression of B4 antigen and significantly decreased the proportion of My9+ and IL2-R-bearing cells. Southern analysis of DNA from leukemic cells revealed monoclonal rearranged heavy and k light-chain immunoglobulin genes. Immunoprecipitation of leukemic cell membrane proteins with a monoclonal antibody recognizing the IL2-R (anti-Tac) revealed a protein with the same molecular weight (55 kilodaltons) as that of the IL2-R present on PHA-stimulated normal T cells. Fresh leukemic cells did not express high-affinity IL2-R and did not proliferate in liquid culture or in a colony assay in the presence of recombinant IL2 (rIL2). PMA-treated blast cells, however, generated B cell colonies in the presence of rIL2, thus suggesting that PMA could induce functional IL2-R on immature leukemic B cells.
Effects of granulocyte-macrophage colony-stimulating factor and erythropoietin on leukemic erythroid colony formation in human early erythroblastic leukemias
Authors: Mitjavila MT , Villeval JL , Cramer P , Henri A , Gasson J , Krystal G , Tulliez M , Berger R , Breton-Gorius J , Vainchenker W
Published: October 2019

Erythroid colonies from five patients with an early erythroblastic leukemia were obtained in “serum-free” cultures in the presence or absence of recombinant granulocyte-macrophage colony-stimulating factor (GM-CSF) and homogeneous native erythropoietin (Epo). Erythroid colonies with abnormal morphology and karyotype could be grown in different culture conditions. Their erythroid nature was ascertained by the presence of carbonic anhydrase I and glycophorin A. Leukemic erythroid progenitors strongly differed from normal progenitors in that spontaneous colonies were always obtained, sometimes with an extremely high plating efficiency (up to 5.7%). Colonies were found to be autonomous from exogenous hematopoietic growth factors because they were still obtained with a high plating efficiency at an average of one cell per culture in the absence of any added growth factor. No evidence for an autocrine secretion of Epo or GM-CSF emerged because Epo or GM- CSF could not be detected by biologic or radioimmunologic assays from the culture supernatant or cellular extracts of the leukemic cells and that Epo or GM-CSF antibodies did not block autonomous growth. In all cases, however, hematopoietic growth factors increased the plating efficiency of the abnormal erythroid progenitors. In the two “de novo” leukemias, leukemic erythroid progenitors responded primarily to Epo, whereas in the three other patients' (chronic myeloid leukemia) blast crisis they responded maximally to GM-CSF plus Epo. Recombinant erythroid-potentiating activity had no effect in any of these cases. These results suggest that the leukemic erythroid clonogenic cells arise from expansion of erythroid progenitors at different levels of differentiation (ie, CFU-E or BFU-E, depending upon the disease) and that autonomous growth is not related to a secretion of Epo or GM-CSF.
The von willebrand factor domain-mediating botrocetin-induced binding to glycoprotein IB lies between Val449 and Lys728
Authors: Fujimura Y , Holland LZ , Ruggeri ZM , Zimmerman TS
Published: October 2019

Botrocetin, a component of Bothrops jararaca venom, induces von Willebrand factor (vWF)-dependent platelet agglutination and has been proposed as an alternative agent to ristocetin for evaluating vWF function. However, important differences between the vWF-platelet interactions induced by these two agents have suggested that different regions of vWF and the platelet may be involved in the interactions induced by the two agonists. We have recently demonstrated that binding of vWF to the platelet glycoprotein (GP) Ib receptor, either induced by ristocetin or as occurs spontaneously with asialo-vWF or vWF from IIb von Willebrand disease, is mediated by a domain residing on a 52/48- kilodalton (kD) tryptic fragment of vWF. This fragment extends from amino acid residue Val (449) to Lys (728). We have now found that this 52/48-kD fragment blocks botrocetin-induced binding of vWF to platelets and completely inhibits botrocetin-induced platelet agglutination. These results provide evidence that the vWF domain-mediating, botrocetin-induced platelet agglutination lies within the region delimited by this fragment and is therefore close to or identical with that which mediates ristocetin-induced binding and spontaneous binding of vWF to platelet GPIb. Anti-GPIb monoclonal antibodies also blocked agglutination, which showed that botrocetin, like ristocetin, induces binding of vWF to the GPIb receptor.
Phorbol ester induces interleukin-2 receptor on the cell surface of precursor thymocyte leukemia with no rearrangement of T cell receptor beta and gamma genes
Authors: Morishima Y , Morishita Y , Adachi K , Tanimoto M , Ohno R , Saito H
Published: October 2019

The early event of thymocyte maturation has been analyzed using acute lymphoblastic leukemia (ALL) cells. A group of ALL cells whose cell surface phenotype was CD2 (SRBC receptor) negative and CD7 (T cell antigen) positive has been considered as precursor thymocyte ALL (pre-T- ALL). No rearrangements of the T cell receptor beta-gene (TCR beta) and gamma-gene (TCR gamma) were found in three of four pre-T-ALL patients. Stimulation of these pre-T-ALL cells with 12–0-tetradecanoylphorbol-13- acetate (TPA) induced only CD25 (Tac) antigen but no other T cell antigens. These findings suggest that the activation pathway of interleukin 2 (IL-2) receptor already exists in the most immature precursor thymocytes. Pre-T-ALL cells from the fourth patients showed the expression of CD3 antigen, and both TCR beta and TCR gamma rearrangement. TPA induced the differentiation of the more mature pre-T- ALL cells of this case in vitro, and not only CD25 (Tac) antigen but also CD4 and CD8 antigens appeared on the cell surface. The low affinity binding of 125I-IL-2 to TPA-stimulated leukemia cells was observed in the three cases of pre-T-ALL tested, and the addition of recombinant IL-2 to TPA-stimulated cells showed no effect on cell proliferation.
Recombinant gibbon interleukin 3 supports formation of human multilineage colonies and blast cell colonies in culture: comparison with recombinant human granulocyte-macrophage colony-stimulating factor
Authors: Leary AG , Yang YC , Clark SC , Gasson JC , Golde DW , Ogawa M
Published: October 2019

The genetic sequences encoding the gibbon and human interleukin 3 (IL 3) proteins were molecularly cloned. The amino acid sequence of the mature gibbon IL 3 protein proved to share 93% homology with the corresponding human protein. We examined the effects of biosynthetic (recombinant) gibbon IL 3 on the proliferation and differentiation of an enriched population of human hematopoietic progenitors and compared the results with the effects of recombinant human granulocyte- macrophage colony-stimulating factor (GM-CSF). Gibbon IL 3 supported the formation of various types of single lineage as well as multilineage colonies by My-10+ bone marrow cells in the presence of human erythropoietin (Ep). In contrast, recombinant human GM-CSF supported the formation of single-lineage colonies and only a small number of multilineage colonies. Both IL 3 and GM-CSF had significant erythroid burst-promoting activity (BPA). Delayed addition of gibbon IL 3 to low serum culture of My-10+ marrow cells supported the formation of blast cell colonies with variable but high replating capability. Human GM-CSF was less effective than IL 3 in support of multipotential blast cell colonies. These results are analogous to the effects of murine IL 3 and GM-CSF on murine progenitors and support the notion that the primary factor for multipotential progenitors is IL 3.
Shear stress activation of platelet glycoprotein IIb/IIIa plus von Willebrand factor causes aggregation: filter blockage and the long bleeding time in von Willebrand's disease
Authors: O'Brien JR , Salmon GP
Published: October 2019

The article explores the finding that high shear alone applied to normal, native blood results in platelet aggregation. A filter with tortuous capillary-sized channels permits a study of the effect of shearing forces at different pressures. Native, heparinized, citrated and EDTA blood and platelet-rich plasma (PRP) were forced through the filter. Normal and von Willebrand's blood were studied, as were the effects of antibodies to platelet glycoproteins (GPr) and to von Willebrand's factor (vWf) and of “membrane-active” drugs. Normally, the filter blocked at 40 mmHg but not at 5 mmHg. Transmission electronmicroscopy of the filter at 40 mmHg showed blockage by platelet aggregates. Initially, the mean transit time through the filter was 8 milliseconds. Platelet retention in the filter occurred in two phases. From 0 to 3 seconds, only high-shear, vWf, and GPrIIb/IIIa were required. From 10 to 20 seconds, retention presumably involved these three attributes, but divalent cations were also essential. Only this phase was inhibited by some membrane-active drugs. ADP- and thrombin- induced aggregation requires GPrIIb/IIIaand fibrinogen. Shear-induced blocking of the filter by blood with a normal concentration of fibrinogen requires GPrIIb/IIIa and vWf. This indicates a different type of exposure of GPrIIb/IIIa. The long bleeding time in vW disease highlights the absolute requirement for vWf and emphasizes the difference in exposure of GPrIIb/IIIa induced by shear stress. Evidently, a process similar to that occurring in the filter is required in normal capillary hemostasis.
Phorbol esters sensitize platelets to activation by physiological agonists
Authors: Siess W , Lapetina EG
Published: October 2019

Phorbol esters such as phorbol 12, 13-dibutyrate (PdBu; 40 to 200 nmol/L) or 12-O-tetradecanoyl phorbol 13-acetate (20 to 80 nmol/L) added to aspirinized platelet-rich plasma (PRP) 5 to 15 seconds prior to various platelet stimuli (epinephrine, ADP, prostaglandin endoperoxide analog U44069, collagen, PAF, or vasopressin) potentiate the rate and extent of aggregation and ATP secretion induced by those agonists. Platelet aggregation, but not secretion, is potentiated at low concentrations of agonists; platelet secretion is potentiated at higher concentrations of the platelet stimuli. Potentiation of platelet responses was also observed when the preincubation time with PdBu was extended to 12 minutes and also occurred in washed platelets. The potentiating effect of phorbol esters is not mediated by formation of arachidonate metabolites or by released ADP. The sensitizing effect of PdBu on platelet aggregation induced by epinephrine is unique, since in contrast to the other platelet stimuli it is also found at maximal concentrations of epinephrine and does not diminish with prolonged preincubation of platelets with PdBu. Activation of protein kinase C ranges from 20% to 80% over control after 1 to 10 minutes of platelet pretreatment with PdBu but dramatically increases after subsequent addition of a stimulus such as vasopressin. In contrast, agonist- induced myosin light chain phosphorylation is reduced after platelet pretreatment with PdBu. The results indicate that protein kinase C activation enhances platelet aggregation and dense granule secretion triggered by physiologic stimuli, although it desensitizes agonist- induced myosin light chain phosphorylation.
Bone marrow transplantation for leukemia following a new busulfan and cyclophosphamide regimen
Authors: Tutschka PJ , Copelan EA , Klein JP
Published: October 2019

Busulfan 16 mg/kg and cyclophosphamide 120 mg/kg were used as conditioning prior to allogeneic marrow transplantation in 50 adult patients with acute nonlymphocytic leukemia (ANLL), acute lymphocytic leukemia (ALL), and chronic myelogenous leukemia (CML). A standard risk group of 20 patients included those with acute leukemia in remission and CML in chronic phase. A high-risk group of 30 patients included individuals with refractory acute leukemia, acute leukemia in relapse, acute leukemia following preleukemia, and CML in accelerated and blastic phase. Complete remission and sustained complete engraftment were achieved in all evaluable patients. The duration of aplasia was remarkably short (median of 8 days), resulting in a low infection rate during the period of neutropenia, a reduced need for blood product support, and a short length of hospital stay. Three-year actuarial relapse-free survival in both standard-risk (88.9% +/- 10.5%) and high- risk (50.5% +/- 9.6%) groups compares favorably with that reported with total body irradiation (TBI) containing regimens.
Intensive chemotherapy in aggressive lymphomas: updated results of LNH- 80 protocol and prognostic factors affecting response and survival
Authors: Coiffier B , Bryon PA , Ffrench M , Blanc M , Sebban C , Berger F , Viala JJ
Published: October 2019

One hundred patients with aggressive malignant lymphomas treated with the LNH-80 regimen were evaluated for long-term survival and pretreatment characteristics predictive of response and survival. LNH- 80 consists of three intensive courses of adriamycin cyclophosphamide vindesine bleomycin (ACVB) followed by sequential consolidation and final intensification. Eighty-four patients went into complete remission (CR), eight had a partial response (PR), three failed to respond, and five died during induction. Twenty-three patients (27%) relapsed, in two of whom a prolonged second remission was obtained. Sixty-three patients are currently alive, two of them with disease. Four patients died in CR. Median survival and median freedom from relapse survival were not reached with a median follow-up of 4 1/2 years. Characteristics negatively associated with response in multivariate analysis were: poor performance status, bone marrow involvement, and two or more extranodal sites of disease. Duration of CR was associated with splenic involvement. Three characteristics were negatively associated with survival in multivariate analysis: age, high grade subtypes, and bone marrow involvement.
High-dose intravenous gamma globulin improves responses to single-donor platelets in patients refractory to platelet transfusion
Authors: Zeigler ZR , Shadduck RK , Rosenfeld CS , Mangan KF , Winkelstein A , Oral A , Ramsey GE , Duquesnoy RJ
Published: October 2019

Ten patients, with bone marrow failure or malignant disorders, became refractory to platelet transfusions using random, as well as partial or fully HLA-matched, single-donor platelets. To determine its effect on platelet refractoriness, intravenous gamma globulin (IV IgG) was administered at 400 or 800 mg/kg/d for five days, and postinfusion platelet responses were monitored. Platelet transfusion responses following intravenous gamma globulin (IV IgG) were graded as follows: Excellent, 48-hour posttransfusion count greater than 50,000/microL; good, 48-hour count greater than 20,000 but less than 50,000/microL; Fair, increased increment, 48-hour count less than 20,000; and failed, no increased increment. Six of ten patients (60%) had improved responses to selected single-donor platelets (two were excellent, three were good, and one was fair). The time to achieve a platelet transfusion count greater than 25,000/microL ranged from one to nine days of IgG therapy. One individual had sustained benefit (greater than 1 year); the remaining responses persisted for 6 to 8 weeks. These results suggest that IV IgG may be useful in the management of platelet refractoriness, especially in patients receiving single-donor platelets.
Fibronectin is required for platelet adhesion and for thrombus formation on subendothelium and collagen surfaces
Authors: Bastida E , Escolar G , Ordinas A , Sixma JJ
Published: October 2019

Fibronectin (FN) plays a role in several adhesion mediated functions including the interaction of platelets with subendothelium. We investigated the role of plasma FN in platelet adhesion and platelet thrombus formation under flow conditions. We used two different perfusion models: the annular chamber with alpha-chymotrypsin-treated rabbit vessel segments, and the flat chamber with coverslips coated with fibrillar purified human collagen type III. Perfusates consisted of washed platelets and washed RBCs, suspended in normal or FN-depleted plasma. Perfusions were carried out for ten minutes at shear rates of 300 or 1,300 s-1. Platelet deposition and thrombus dimensions were evaluated morphometrically by a computerized system. We found that depletion of plasma fibronectin significantly reduced the percentage of total coverage surface and percentage of platelet thrombus, at both shear rates studied, and in both perfusion systems (P less than .01) (P less than .01). The dimensions of the platelet thrombi formed in perfusions at high shear rate were also significantly reduced in perfusions carried out with FN depleted plasma (P less than .01). Addition of purified FN to FN-depleted perfusates restored all values to those measured in the control perfusions. These results indicate that plasma FN is required for platelet aggregate and thrombus formation following adhesion under flow conditions.
Fibrin monomer induces binding of endogenous platelet von Willebrand factor to the glycocalicin portion of platelet glycoprotein IB
Authors: Parker RI , Gralnick HR
Published: October 2019

This study demonstrates that when platelets are stimulated by thrombin in the presence of low concentrations of purified human fibrinogen (10 to 20 micrograms/mL, final concentration) binding of released platelet von Willebrand factor (plt-vWF) to the platelet membrane is enhanced. This effect appears to be mediated by fibrin monomer produced by the action of thrombin on the fibrinogen in the incubation suspension. When fibrin polymerization is inhibited, the binding of released plt-vWF to the platelets is markedly increased. This enhanced binding is dependent on platelet glycoprotein Ib (GPIb) as shown by a decreased response with Bernard-Soulier platelets and inhibition by both monoclonal and polyclonal antibodies against glycocalicin. The binding of fibrin to thrombin-activated platelets preincubated with monoclonal antibody against GPIIb/IIIa is increased when the predominant form of fibrin is fibrin monomer. The fibrin binding is also decreased in the presence of antibody against glycocalicin. Our data demonstrate that fibrin monomer facilitates plt-vWF binding to the glycocalicin portion of platelet GPIb on thrombin-stimulated platelets and that binding of fibrin monomer to glycocalicin is necessary for this response to occur.
Interleukin-2 production and response to interleukin-2 by peripheral blood mononuclear cells from patients after bone marrow transplantation: II. Patients receiving soybean lectin-separated and T cell-depleted bone marrow
Authors: Welte K , Keever CA , Levick J , Bonilla MA , Merluzzi VJ , Mertelsmann R , Evans R , O'Reilly RJ
Published: October 2019

The ability of peripheral blood mononuclear cells (PBMC) to produce and respond to interleukin-2 (IL-2) was evaluated in 50 recipients of HLA- identical bone marrow (BM) depleted of mature T cells by soybean agglutination and E rosetting (SBA-E-BM). In contrast to our previous findings in recipients of unfractionated marrow, during weeks 3 to 7 post-SBA-E-BM transplantation (BMT), PBMC from the majority of patients spontaneously released IL-2 into the culture medium. This IL-2 was not produced by Leu-11+ natural killer cells, which were found to be predominant in the circulation at this time, but by T11+, T3+, Ia antigen-bearing T cells. The IL-2 production could be enhanced by coculture with host PBMC frozen before transplant but not by stimulation with mitogenic amounts of OKT3 antibody, thus suggesting an in vivo activation of donor T cells or their precursors by host tissue. Spontaneous IL-2 production was inversely proportional to the number of circulating peripheral blood lymphocytes and ceased after 7 to 8 weeks post-SBA-E-BMT in most of the patients. In patients whose cells had ceased to produce IL-2 spontaneously or never produced this cytokine, neither coculture with host cells nor stimulation with OKT3 antibody thereafter induced IL-2 release through the first year posttransplant. Proliferative responses to exogenous IL-2 after stimulation with OKT3 antibody remained abnormal for up to 6 months post-SBA-E-BMT, unlike the responses of PBMC from recipients of conventional BM, which responded normally by 1 month post-BMT. However, the upregulation of IL- 2 receptor expression by exogenous IL-2 was found to be comparable to normal controls when tested as early as 3 weeks post-SBA-E-BMT. Therefore, the immunologic recovery of proliferative responses to IL-2 and the appearance of cells regulating in vivo activation of T cells appear to be more delayed in patients receiving T cell-depleted BMT. Similar to patients receiving conventional BMT, however, the ability to produce IL-2 after mitogenic stimulation remains depressed for up to 1 year after transplantation.
The metabolite 1 alpha,25-dihydroxyvitamin D3 enhances lymphokine- mediated activation of the oxidative metabolism of the U937 cell line and phosphorylation of a 48-kD respiratory burst-associated protein
Authors: Snipes RG , Ways K , D'Amico CN , Sivam G , Gray TK , Cohen MS
Published: October 2019

U937 cells respond to a variety of stimuli with increased differentiation as manifested by reduced growth, increased adherence, increased expression of several surface receptors, and increased capacity for phagocytosis and formation of reactive oxygen intermediates. In the present study the effects of lymphocyte conditioned media, recombinant interferon-gamma (IFN-gamma), and 1 alpha,25-dihydroxyvitamin D3 (1,25(OH)2D3) on the ability to form reactive oxygen intermediates by U937 cells were measured by using the luminol-dependent luminescence (LDL) assay. Neither 1,25(OH)2D3 alone nor IFN-gamma alone enhanced competence for phorbol myristate acetate- stimulated LDL. Cells were capable of moderate LDL after exposure to lymphocyte conditioned media, and this was enhanced by 1,25(OH)2D3 (10(- 8) mol/L) and other vitamin D metabolites at higher concentrations. This effect was not secondary to accelerated production of myeloperoxidase, which is important in the LDL assay. Enhanced phorbol myristate acetate-stimulated phosphorylation of a 48-kd substrate was observed in 32P-labeled intact cells treated with 1,25(OH)2D3 alone or in combination with IFN-gamma. Treatment of cells with IFN-gamma or lymphocyte conditioned media did not alter phosphorylation. These results support the concept that 1,25(OH)2D3 plays a role in phagocyte differentiation and activation beyond the effects of lymphokines. Protein kinase C-mediated phosphorylation reactions may be necessary for the ability of U937 cells to reduce O2 and required for maximal activity under some conditions of incubation.
Tumor necrosis factor: receptors on hematopoietic cells
Authors: Munker R , DiPersio J , Koeffler HP
Published: October 2019

Tumor necrosis factor (TNF) is a monokine that is cytotoxic/cytostatic for a variety of tumor cells and has multiple effects on normal cells. We demonstrate that normal and malignant human myeloid cells express a single class of high-affinity receptors (400 to 1,900 per cell, KD 20 to 90 pmol/L) for TNF. Mitogen-stimulated lymphocytes have a similar number of TNF receptors, whereas resting lymphoid cells have fewer receptors. RBCs and platelets have no detectable TNF receptors. No correlation is observed between the receptor number, receptor affinity, and the cytotoxic effect of TNF on myeloid cell lines. Significant cytotoxic effects of TNF on the most sensitive myeloid cell line (HL-60 promyelocytes) could be seen at concentrations tenfold lower than those concentrations at which one half of the TNF receptors were occupied. Our data show that significant biologic effects of TNF can occur at low levels of receptor occupancy and resistance to TNF is not related to the absence of TNF receptors on certain myeloid leukemic cell lines.
Expression of myelomonocytic antigens on chronic lymphocytic leukemia B cells correlates with their ability to produce interleukin 1
Authors: Morabito F , Prasthofer EF , Dunlap NE , Grossi CE , Tilden AB
Published: October 2019

We analyzed the expression of myelomonocytic-associated antigens on lymphocytes from B cell chronic lymphocytic leukemia (B-CLL) patients. Blood mononuclear cells were depleted of monocytes by one-step Percoll density gradient centrifugation and tested for antigen expression by fluorescent microscopy and flow cytometry. The reactivity of patient lymphocytes was as follows: 26 of 31 were positive for CD14 (Myr), 22 of 31 for a monocyte Fc receptor (MFC-1), 22 of 31 for CD11b (C3bi receptor), eight of 31 for CD15 (Leu-M1), five of 18 for CD13 (My 7), seven of 18 for My 9, and five of 30 for Mo 2. The B lymphocytes of B- CLL patients were also tested for the ability to produce interleukin 1 (IL-1) after depletion of monocytes and T lymphocytes. In 13 of 17 cases, B lymphocytes of patients produced IL-1 as detected in a mouse thymocyte proliferation assay and, in selected cases, a radioimmunoassay specific for IL-1 beta. The 13 cases that produced IL- 1 were also positive for the expression of one or more myelomonocytic- associated antigens, whereas the four cases that did not produce IL-1 lacked expression of these antigens. In conclusion, the malignant B cells of B-CLL patients frequently express a variety of antigens generally considered specific for myelomonocytic cells, and expression of these antigens is associated with the ability to produce IL-1.
Analysis of the erythroid phenotype of HEL cells: clonal variation and the effect of inducers
Authors: Papayannopoulou T , Nakamoto B , Kurachi S , Nelson R
Published: October 2019

The erythroid phenotype of HEL cells, before and after the addition of a variety of inducers, was assessed at the cellular and biochemical level. Among 14 inducers used, delta-aminolevulinic acid (delta-ALA) was identified as the most optimal inducer of heme and globin synthesis in HEL cells. The relative synthesis of globin chains produced by HEL cells, mainly gamma and alpha chains with traces of epsilon and zeta chains, was not influenced by the majority of the inducers used. However, delta-ALA and bromodeoxyuridine did increase the relative synthesis of alpha and epsilon chains respectively. Subcloning experiments revealed heterogeneity in the constitutive expression of alpha globin; however, the latter was inducible in all clones by either hemin or delta-ALA. One rare clone of HEL cells was found to produce, in contrast to parental cells, significant amounts of epsilon globin. This clone differed from K562 cells by the absence of any zeta globin expression, thus demonstrating the independent regulation of the two embryonic chains, epsilon and zeta. Changes in the expression of several surface markers specific for erythroid cells were found to accompany the globin accumulation in these cells, and some of these changes appeared to be inducer specific. Thus, the unique globin and nonglobin phenotypic properties of HEL cells and their subclones make them valuable cellular models complementary to the existing K562 cells for studying regulatory aspects of erythroid-specific proteins.