bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thrombin-induced gap formation in confluent endothelial cell monolayers in vitro
Authors: Laposata M , Dovnarsky DK , Shin HS 
Published: October 2019

Abstract
When thrombin is incubated with confluent monolayers of human umbilical vein endothelial cells in vitro, there is a change in the shape of the endothelial cells that results in gaps in the monolayer, disrupting the integrity of the endothelium and exposing the subendothelium. Using a grid assay to measure this phenomenon, we observed that up to 80% of the surface area once covered by cells was uncovered after a 15-min incubation with 10(-2) U/ml (10(-10)M) thrombin. The effect was apparent within 2 min and did not remove cells from the surface of the culture dish. The gaps in the monolayer completely disappeared within 2 hr after exposure to thrombin. The effect of thrombin was inhibited by preincubation of thrombin with hirudin or antithrombin III plus heparin or by preincubation of the monolayers with dibutyryl cyclic adenosine monophosphate (dbcAMP). Histamine also induced gap formation in endothelial cell monolayers. Both pyrilamine and cimetidine prevented the histamine-induced effect, but they had no effect on thrombin- induced gap formation. Intact monolayers were not disrupted by bradykinin, serotonin, C5a, or C3a. Our results suggest that small amounts of thrombin can induce repeated and transient exposure of the subendothelium, a situation believed to be conducive to atherogenesis and thrombosis.
Effect of mouse interferon on growth and differentiation of mouse bone marrow cells stimulated by two different types of colony-stimulating factor
Authors: Yamamoto-Yamaguchi Y , Tomida M , Hozumi M 
Published: October 2019

Abstract
The effects of mouse L-cell interferon (IFN) on growth of mouse bone marrow cells and their differentiation into macrophages and granulocytes were investigated in a liquid suspension culture system with two different types of colony-stimulating factor (CSF). Within 7 days, most bone marrow cells differentiated into macrophages in the presence of macrophage colony-stimulating factor (M-CSF) derived from mouse fibroblast L929 cells, but into both granulocytes (40%) and macrophages (23%) in the presence of a granulocyte-macrophage colony- stimulating factor (GM-CSF) from mouse lung tissue. IFN inhibited growth of bone marrow cells with both M-CSF and GM-CSF, but had 20 times more effect on bone marrow cells stimulated with M-CSF than on those stimulated with GM-CSF. A low concentration of IFN (50 IU/ml) stimulated production of macrophages by GM-CSF in liquid culture medium, whereas it selectively inhibited colony formation of macrophages in semisolid agar culture. IFN caused no detectable block of late stages of differentiation; mature macrophages and granulocytes were produced even when cell proliferation was inhibited by IFN. These results indicate that IFN preferentially affects growth and differentiation of the cell lineage of macrophages among mouse bone marrow cells.
Natural killer and suppressor T-cell chronic lymphocytic leukemia
Authors: Palutke M , Eisenberg L , Kaplan J , Hussain M , Kithier K , Tabaczka P , Mirchandani I , Tenenbaum D 
Published: October 2019

Abstract
A patient with low-grade lymphocytosis, splenomegaly, and neutropenia, but adequate myeloid leukogenesis, was found to have chronic lymphocytic leukemia, which represented a clonal proliferation of a distinct T-lymphocyte subset. The lymphocytes did not form E rosettes but had an OKT3+, OKT4+, OKT6+, OKT8+, OKT11+, HNK-1+, HNK-36+, OKIa1+, OKM1+ phenotype and functionally had suppressor and natural killer activity. Morphologically, they were large granular lymphocytes, which were strongly acid phosphatase positive and nonspecific esterase negative. They did not respond to mitogens, or to allogeneic cells. Initially, the spleen appeared to be the most involved organ and, judging from the high proportion of leukemic splenic lymphocytes in the S and G2/M phases of the cell cycle, was also the organ of origin of the leukemic cells. Only a few leukemic cells in the blood and bone marrow were in S and G2/M phases. After splenectomy, the lymphocyte count rose considerably and the bone marrow became progressively more infiltrated by tumor nodules. One year after diagnosis, the patient was started on chemotherapy because of progressive anemia. He responded to the chemotherapy by normalization of the hemoglobin and neutrophil count and had a moderate decrease in the bone marrow involvement and peripheral lymphocytosis.
Enzyme analysis of lymphoproliferative diseases: a useful addition to cell surface phenotyping
Authors: van de Griend RJ , van der Reijden HJ , Bolhuis RL , Melief CJ , von dem Borne AE , Roos D 
Published: October 2019

Abstract
Lymphocytes from patients with acute and chronic T-cell malignancy or chronic T gamma lymphocytosis were characterized by studying the activity of three enzymes involved in purine metabolism and by determining the isoenzyme pattern of lactate dehydrogenase (LDH) in addition to analysis of surface marker expression with monoclonal antibodies. Four clinically different types of disease were distinguished on the basis of the enzyme parameters. Lymphocytes from patients with acute lymphocytic leukemia (T-ALL) showed an enzyme profile similar to that of normal thymocytes, i.e., an elevated level of adenosine deaminase (ADA) activity as compared with normal T lymphocytes, reduced activities of purine 5′nucleotidase (5′NT) and purine nucleoside phosphorylase (PNP), and a binomial distribution of the LDH isoenzyme pattern. Cells from “null”-ALL patients had an ADA/PNP ratio that was intermediate between that of normal T cells and that of T-ALL cells or thymocytes, but their 5′NT activity and LDH isoenzyme pattern were thymocyte-like. Patients with chronic T-cell proliferation were subdivided into those with chronic T gamma lymphocytosis and those with proven chronic T malignancy. The lymphocytes from these patients had ADA and PNP activities within the ranges of those of normal T lymphocytes. However, the ADA activity and/or the ADA/PNP ratio were consistently higher in the cells from the patients with chronic T gamma lymphocytosis than in those with chronic T malignancy. The enzyme profile of the cells from the T gamma patients was similar to that of T gamma cells of normal individuals. The cells from patients with chronic T malignancies showed a heterogeneous enzyme pattern as compared with that of normal T lymphocytes. Analysis with monoclonal antibodies enabled us to distinguish null-ALL patients from the other leukemias studied, but a distinction between chronic and acute T-cell proliferation disease, for instance, was not possible with monoclonal antibodies alone. Our data demonstrate that the enzyme profiles studied provide supplementary information for classification and diagnosis of lymphoproliferative diseases to that obtained with cell surface markers alone.
Specific toxicity of 2-chlorodeoxyadenosine toward resting and proliferating human lymphocytes
Authors: Carson DA , Wasson DB , Taetle R , Yu A 
Published: October 2019

Abstract
2-Chlorodeoxyadenosine (CdA), an adenosine-deaminase-resistant purine deoxynucleoside, is markedly toxic toward human T-lymphoblastoid cell lines in vitro and is an effective agent against L1210 leukemia in vivo. The present studies have examined the toxicity, and in some cases, metabolism, of CdA in (1) multiple established human cell lines of varying phenotype, (2) leukemia and lymphoma cells taken directly from patients, (3) normal bone marrow cells, and (4) normal peripheral blood lymphocytes. Nanomolar concentrations of CdA blocked the proliferation of lymphoblastoid cell lines with a high ratio of deoxycytidine kinase to deoxynucleotidase. The drug had virtually no effect on the growth of cell lines derived from solid tissues. The CdA inhibited the spontaneous uptake of tritiated thymidine by many T and non-T, non-B acute lymphoblastic leukemia cell specimens at concentrations less than or equal to 5 nM. The same concentrations did not impair either thymidine uptake or granulocyte-monocyte colony formation by normal bone marrow cells. In common with deoxyadenosine, but unlike several other agents affecting purine and purine metabolism, CdA was lethal to resting normal T lymphocytes and to slowly dividing malignant T cells. In both resting and proliferating lymphocytes, the CdA was phosphorylated by deoxycytidine kinase and entered a rapidly turning over nucleotide pool. Dividing lymphocytes also incorporated abundant CdA into DNA. The selective toxicity of CdA toward both dividing and resting lymphocytes may render the drug useful as an immunosuppressive or antileukemic agent.
Analysis of B-cell antigens in normal reactive lymphoid tissue using four B-cell monoclonal antibodies
Authors: Hofman FM , Yanagihara E , Byrne B , Billing R , Baird S , Frisman D , Taylor CR 
Published: October 2019

Abstract
Lymph nodes from 13 cases of reactive hyperplasia were examined with four different monoclonal antibodies to B cells. B-1 recognizes an antigen of 30,000 daltons on B cells. CB-2 was prepared with normal spleen and binds to a glycolipid. BA-1 labels surface immunoglobulin- positive cells, but not T lymphocytes or monocytes. B-532 recognizes an antigenic determinant of 45,000 daltons. Using the immunoperoxidase method on frozen sections of reactive lymph nodes, the staining patterns of these four unique antibodies showed dramatic differences. B- 1 labeled 80%-90% of the germinal center cells and 10%-50% of the mantle region. Few interfollicular cells were positive. CB-2 stained predominantly in the mantle area (50%-90% positive cells), with moderate staining in the germinal center as well and less than 1% positive cells in the diffuse cortex. BA-1 exhibited predominant labeling in the mantle (50%-90%), with little staining in the germinal center. A large number of cells in the interfollicular, subcapsular, and medullary regions expressed the BA-1 antigen. The B-5 antibody demonstrated intense staining in the follicle (50%-95%). This staining often appeared to be polarized within the germinal center. The mantle zone demonstrated staining of 30%-50% of the cells. The different staining patterns of the B-cell antibodies, as demonstrated by the in situ distribution of positive cells within the lymph node, may reflect stages of development or activation of the B-cell population.
Increased respiratory burst in myeloperoxidase-deficient monocytes
Authors: Locksley RM , Wilson CB , Klebanoff SJ 
Published: October 2019

Abstract
Studies of the respiratory burst in myeloperoxidase (MPO) deficient monocytes were undertaken to assess the physiologic consequence of the absence of MPO in these cells. As previously demonstrated with neutrophils, MPO-deficient monocytes had a greater initial rate, duration, and total superoxide production in response to phagocytosis of zymosan than did normal monocytes. Introduction of purified eosinophil peroxidase (EPO) into the phagosome by binding the enzyme to the surface of the zymosan particles changed the hypermetabolic characteristics of superoxide production in MPO-deficient cells to more closely resemble normal cells, but had no effect on superoxide generation by the normal monocytes. Further, inactivation of the bound EPO before ingestion restored the supranormal respiratory burst by the MPO-deficient cells. Iodination by MPO-deficient monocytes was significantly depressed as compared to normal monocytes following the ingestion of zymosan (1.9 versus 10.1 nmole I-/10(7) monocytes/30 min; p less than 0.01). In contrast, iodination was markedly augmented in MPO-deficient cells compared to normal cells after ingestion of zymosan coated with EPO (208 versus 70 nmole I-/10(7) monocytes/30 min; p less than 0.005), presumably reflecting the greater amounts of hydrogen peroxide formed by MPO-deficient cells. There were no differences in the levels of endogenous scavengers of reactive oxygen products (catalase, superoxide dismutase, glutathione peroxidase and reductase, and total glutathione) in MPO-deficient and normal monocytes that would account for the enhanced respiratory burst of MPO-deficient cells. These findings support a role for peroxidase in the termination of the respiratory burst of monocytes.
N-formylmethionyl-leucyl-[3H]phenylalanine binding, superoxide release, and chemotactic responses of human blood monocytes that repopulate the circulation during leukapheresis
Authors: Alteri E , Leonard EJ 
Published: October 2019

Abstract
Human blood monocytes comprise two subpopulations: one migrates to the chemoattractant, N-formylmethionyl-leucyl-phenylalanine (fMet-Leu-Phe), and has saturable binding sites for this peptide; the other does not migrate and exhibits little peptide binding. To determine if expression of binding sites was a function of monocyte maturation, we depleted human subjects of blood monocytes by leukapheresis so that the circulation was repopulated by monocytes released from the bone marrow. Pre- and postleukapheresis monocytes were then compared for fMet-Leu- [3H]Phe binding, superoxide generation, and chemotactic responses. No significant differences in peptide binding curves were found, suggesting that receptor expression was stable over the maturational span represented by these two groups of cells. This supports the hypothesis that there are two distinct lineages of monocytes with respect to expression of receptors for fMet-Leu-Phe. An additional finding of interest was that the number of chemotactically responsive cells immediately postleukapheresis was half the control. This was a transient state; monocyte responses were normal 3 hr after termination of leukapheresis, suggesting that they rapidly become functionally mature.
The amount of platelet-bound albumin parallels the amount of IgG on washed platelets from patients with immune thrombocytopenia
Authors: Kelton JG , Steeves K 
Published: October 2019

Abstract
The biologic relevance of the increased platelet-associated IgG (PAIgG) on platelets from patients with idiopathic thrombocytopenic purpura (ITP) is unclear. Platelets from ITP patients are often larger than normal, and it is possible that the increased IgG is not specific but passively related to platelet size. The measurement of platelet-bound albumin could provide information concerning the specificity of the platelet-bound IgG, since albumin, like IgG, is a plasma protein, but unlike IgG, is not an active participant in immunologic reactions. Albumin is also a normal constituent of platelet membrane, and increased platelet albumin could indicate an increased platelet mass. Platelet-bound albumin, IgG, and total platelet protein were measured on both intact and disrupted platelets from healthy individuals (n = 25) and patients with ITP (n = 21). Platelet IgG and albumin were measured in an immunoradiometric assay using intact antisera and F(ab')2 fragments prepared from the same antisera. There was no relationship between platelet-bound IgG or albumin, and platelet size measured by either platelet protein or platelet volume, (r less than 0.3 for all interactions). In contrast, there was a significant correlation between platelet-bound albumin and platelet-bound IgG (r = 0.7, n = 21, p less than 0.001). Those patients with elevated platelet PAIgG also had elevated platelet albumin, and this relationship was irrespective of the total platelet protein content or mean platelet volume. It is possible that the increased platelet-bound IgG in ITP reflects an increase in platelet surface area or contaminating platelet fragments that are not manifested as an increase in platelet volume or total platelet protein. Alternatively, a platelet membrane abnormality may occur in ITP that results in the uptake of significant amounts of plasma proteins. Either possibility implies that not all of the IgG on platelets from patients with ITP is pathologic IgG.
The kinetic properties of the ecto-ATPase of human peripheral blood lymphocytes and of chronic lymphatic leukemia cells
Authors: Gutmann HR , Chow YM , Vessella RL , Schuetzle B , Kaplan ME 
Published: October 2019

Abstract
This study examines whether the activity of the Mg2+-dependent ecto- ATPase of the surface membrane of the human lymphocyte is changed in chronic lymphocytic B-cell leukemia (CLL-B) and may be an indicator of malignant transformation. The ecto-ATPase activities of preparations consisting predominantly of T or B cells were compared to each other and to the ecto-ATPase of the CLL peripheral blood lymphocytes (PBL). The specific activities and kinetic constants of the ecto-ATPase of the cell preparations were determined with [gamma-32P] adenosine triphosphate (ATP) as substrate. B-enriched lymphocytes had nearly fourfold greater specific activity and apparent Vmax than T-enriched lymphocytes, while the Km values of both cell types showed no significant difference. The specific activities and kinetic constants of the ecto-ATPase of the CLL PBL were significantly higher than the corresponding values of PBL or of B-enriched lymphocytes. Judging from the kinetic constants the ecto-ATPase of the CLL-B lymphocyte appears to be an enzyme that is distinctly different from that of the normal B cell. On the basis of the kinetic properties, the ecto-ATPase of the B cell appears to be identical with that of the T cell. The differences in the maximal velocities of the hydrolysis of ATP by B and T cells are likely due to a greater number of enzymatic sites on the B cell.
Antithymocyte globulin reacts with many normal human cell types
Authors: Greco B , Bielory L , Stephany D , Hsu SM , Gascon P , Nienhuis A , Young N 
Published: October 2019

Abstract
Antithymocyte globulin (ATG) is frequently effective therapy for aplastic anemia. Its mechanism of action is often assumed to be upon a lymphocyte inhibitor of hematopoiesis. However, specificity for T lymphocytes would not be anticipated from consideration of the method of preparing ATG. In fact, using flow microfluorometry and fluorescence immunohistochemistry, we have found that ATG binds to virtually all circulating lymphocytes, granulocytes, and platelets, as well as to bone marrow cells. Extensive absorption of ATG with either granulocytes or lymphocytes does not eliminate reactivity with the opposite cells, indicating that ATG recognizes some distinct antigens on each cell type. Treatment of cells with ATG blocks the binding of monoclonal antibodies directed against either lymphocyte differentiation or histocompatibility antigens. ATG also binds to visceral tissues, including thymus and testis cell membranes and the nuclear and cytoplasmic components of tonsil, kidney, liver, breast, lung, and intestine. In vitro cytotoxicity of ATG was demonstrated for both T and non- T lymphocytes and platelets. Despite its name, ATG is not specific for a particular cell type, and it would be premature to conclude that its effect is mediated through a specific lymphocyte population.
Role of ADP-ribosyl transferase in differentiation of human granulocyte- macrophage progenitors to the macrophage lineage
Authors: Francis GE , Gray DA , Berney JJ , Wing MA , Guimaraes JE , Hoffbrand AV 
Published: October 2019

Abstract
Nuclear adenosine diphosphate-ribosyl (ADP-ribosyl) transferase is a chromatin-bound enzyme catalyzing the transfer of ADP-ribose from NAD+ to chromatin proteins. The physiologic function of this covalent modification of chromatin has not been fully established, but roles in both DNA repair and in differentiation have been proposed. We demonstrate that three specific inhibitors of ADP-ribosyl transferase (5-methylnicotinamide, 3-methoxybenzamide, 3-aminobenzamide) inhibit differentiation of human granulocyte-macrophage progenitor cells to the macrophage lineage. Differentiation to the neutrophil-granulocyte lineage is much less affected. The inhibition of macrophage differentiation seems to relate to the ability of these compounds to inhibit ADP-ribosyl transferase. A structural analogue (3- methoxybenzoic acid), which is not inhibitory for the enzyme, did not inhibit macrophage differentiation. Additional evidence for a role of ADP-ribosyl transferase in the differentiation of granulocyte- macrophage progenitors was obtained from experiments in which enzyme activity levels were measured in permeabilized marrow cells. Marrow cell ADP-ribosyl transferase activity increased after 3-hr stimulation by the differentiation/proliferation stimulus--granulocyte-macrophage colony-stimulating activity (GM-CSA). Unstimulated marrow cells showed low or undetectable levels of enzyme activity.
The mechanism of action of the antiinflammatory agents dexamethasone and Auranofin in human polymorphonuclear leukocytes
Authors: Coates TD , Wolach B , Tzeng DY , Higgins C , Baehner RL , Boxer LA 
Published: October 2019

Abstract
Human polymorphonuclear neutrophils (PMN) were treated with the antiinflammatory agents dexamethasone or Auranofin. PMN treated with dexamethasone in a dose range of 0.25–1 microM or Auranofin, 5–15 mM, were stimulated with 10(-7)M N-formyl-methionyl-leucyl-phenylalanine (FMLP). These agents were shown to inhibit the functional responses of degranulation and superoxide production in a dose-dependent manner. Similarly, the change in electrophoretic mobility, reflecting cell surface charge, was blocked. While both agents inhibited change in the fluorescence of the calcium chelate probe chlorotetracycline (CTC), the pattern of inhibition was significantly different. Dexamethasone appeared to inhibit the CTC response during its latter phases, while Auranofin inhibited all aspects of the CTC response. Auranofin was additionally shown to significantly decrease specific binding of FMLP, as well as the number of FMLP receptors. The two agents thus appear to act by different mechanisms. Dexamethasone is shown to have an effect on membrane-bound calcium release as measured by CTC, while Auranofin interferes with receptor binding.
Evidence for the separate human T-lymphocyte subpopulations that collaborate with autologous monocyte/macrophages in the elaboration of colony-stimulating activity and those that suppress this collaboration
Authors: Verma DS , Johnston DA , McCredie KB 
Published: October 2019

Abstract
We investigated the interaction of monocyte/macrophages and autologous T lymphocytes in the methanol extraction residue (MER) of BCG-induced production of granulocyte-macrophage colony-stimulating activity (CSA). Coincubation of monocyte/macrophages and T lymphocytes at a 1:3 ratio produces an optimum collaboration; a change to a 1:9 ratio diminished this collaboration. Coincubation of monocyte/macrophages and T lymphocytes primed with lithium carbonate (2 meq/liter) for 40 hr synergistically increased CSA elaboration and prevented the decline in CSA noted for the 1:9 monocyte/macrophage: T lymphocyte ratio. In contrast, concanavalin-A-primed T lymphocytes did not enhance CSA elaboration at any monocyte/macrophage:T lymphocyte ratio except, occasionally, at 1:9. However, this was overcome if the T lymphocytes were primed with both concanavalin-A and lithium carbonate before their coincubation with monocyte/macrophages. Further cell-mixing experiments revealed that concanavalin-A-primed T lymphocytes contained a subpopulation that suppressed monocyte/macrophage and T-lymphocyte collaboration. Activation of suppressor T lymphocytes could be effectively prevented by lithium carbonate and, in a dose-dependent manner, by irradiation. Also, suppressor T lymphocytes not only diminished the elaboration of colony-stimulating factor(s), but also elaborated an inhibitor of granulocyte-macrophage colony-forming cells. We further demonstrated that the respective hemopoietic helper and suppressor T-lymphocyte activities could be enriched with OKT8- (or OKT4+) and OKT8+ subpopulations.