bluuebunny/crossref_metadata_2025_split huggingface dataset:
Oxidative mechanisms utilized by human neutrophils to destroy Escherichia coli
Authors: Passo SA , Weiss SJ 
Published: October 2019

Abstract
Serum-opsonized bacteria are efficiently ingested and killed by neutrophils within the phagocytic vacuole, where they are exposed to an array of reactive oxygen metabolites and toxic lysosomal components. Although bacteria may be destroyed by oxygen-independent mechanisms alone, many types of bacteria are not killed effectively unless they are attacked by oxygen metabolites. However, the apparent inability of extracellular scavengers, or inhibitors, of oxygen metabolites to gain access to the phagocytic vacuole makes this system difficult to evaluate. Therefore, we investigated the ability of neutrophils triggered with phorbol myristate acetate to destroy unopsonized E. coli in a serum-free model system. Neutrophils incubated with phorbol myristate acetate at a cell-to-bacteria ratio of 1:4 caused a greater than 95% reduction in colony-forming units (CFU) of E. coli in 60 min at 37 degrees C. Destruction of E. coli by the stimulated neutrophils was dependent on neutrophil number, stimuli concentration, and the incubation period. The neutrophil-mediated bactericidal effect was stimulated by superoxide dismutase, but was inhibited by catalase, azide, or compounds known to scavenge hypochlorous acid. Although stimulated neutrophils can generate long-lived endogenous N- chloroamines , these compounds did not play a direct role in destruction of E. coli in our model system. However, in the presence of exogenous iodide, endogenous N- chloroamines exerted a powerful bactericidal effect. Finally, neutrophils triggered with opsonized zymosan could also mediate E. coli destruction by a qualitatively similar process. Thus, we have demonstrated that neutrophils have the potential to utilize the myeloperoxidase system to generate bactericidal quantities of a species with characteristics similar to, if not identical with, hypochlorous acid.
A new variant of dominant type II von Willebrand's disease with aberrant multimeric pattern of factor VIII-related antigen (type IID)
Authors: Kinoshita S , Harrison J , Lazerson J , Abildgaard CF 
Published: October 2019

Abstract
A new type II variant form of von Willebrand's disease has been recognized in a mother and daughter who have bleeding manifestations typical of von Willebrand's disease. Laboratory findings include consistently prolonged bleeding times, with normal levels of factor VIII procoagulant and antigen, but decreased ristocetin cofactor activity. Electrophoresis in SDS 1.5% agarose gel and reaction with 125I-labeled anti-factor VIII-related antigen rabbit IgG, followed by autoradiography, revealed that both plasma and platelets lack the large multimers of factor VIII-related antigen. In 2.5% gel, the propositus plasma lacked the normal “triplet” pattern. In 3.0% gel, a 5-band pattern was observed in normal, type IIA, and type IIB plasma, whereas type IIC plasma revealed a 2-band pattern. The patient's plasma revealed a 4-band pattern distinctly different from normal or other type II variants. We suggest that this new variant be labeled type IID, until a more appropriate nomenclature is developed.
Differential binding of plasminogen to crosslinked and noncrosslinked fibrins: its significance in hemostatic defect in factor XIII deficiency
Authors: Sakata Y , Mimuro J , Aoki N 
Published: October 2019

Abstract
In spontaneous fibrinolysis of an alpha 2-plasmin inhibitor-deficient plasma clot or tissue-type plasminogen activator-induced fibrinolysis in a purified system without alpha 2-plasmin inhibitor, the lysis was faster when factor XIII-mediated crosslinking of fibrin to fibrin did not occur. During the initial period, the binding of plasminogen to fibrin steadily increased with incubation time. The initial level and subsequent increase of the binding, which may be critical for the subsequent development of fibrinolysis, were more remarkable when fibrin was not crosslinked. The amount of glu- or lys-plasminogen bound to noncrosslinked fibrin was around 4 or 1.5 times larger than the amount of the respective plasminogen bound to crosslinked fibrin. Plasmin was also found to be bound to noncrosslinked fibrin twice as much as the amount bound to crosslinked fibrin. Structural changes induced by crosslinking of fibrin alpha-chain may reduce either the affinity or the number of available complementary sites to lysine binding sites of plasmin(ogen), thereby decreasing the binding of plasmin(ogen) to fibrin. These results suggest that an increased affinity of noncrosslinked fibrin for plasmin(ogen) is contributory to the accelerated fibrinolysis observed in factor XIII deficiency, in addition to an absence of crosslinking of alpha 2-plasmin inhibitor to fibrin.
T lymphocyte repopulation and differentiation after bone marrow transplantation. Early shifts in the ratio between T4+ and T8+ T lymphocytes correlate with the occurrence of acute graft-versus-host disease
Authors: Gratama JW , Naipal A , Oljans P , Zwaan FE , Verdonck LF , de Witte T , Vossen JM , Bolhuis RL , de Gast GC , Jansen J 
Published: October 2019

Abstract
Acute graft-versus-host disease (GVHD), a major complication of allogeneic bone marrow transplantation (BMT), is probably mediated by T lymphocytes present in the marrow graft. In this study, the repopulation of the peripheral blood with T4+ and T8+ T cells was investigated during the period preceding the occurrence of acute GVHD. Twenty-four allogeneic and 11 autologous BMT recipients were monitored from day 4 post-BMT onward by the use of monoclonal antibodies, indirect immunofluorescence, and flow cytometry. The recipients of allogeneic transplants received methotrexate as GVHD prophylaxis. Similar recovery patterns for T4+ and T8+ T cells were found following autologous and allogeneic BMT. However, lymphoid repopulation occurred at a clearly faster rate after autologous BMT. T4+ T cells were the first to reappear in the peripheral blood, followed by T8+ T cells 4–7 days later. The T8+ T cell reconstitution occurred at an even faster rate in patients who were to develop grade II-IV GVHD, as compared with those with grade O-I GVHD, thus leading to an earlier decrease in the T4/T8 ratio. Of 10 patients with a T4/T8 ratio less than 2.5 at day 19, 9 developed grade II-IV GVHD and 1 showed no GVHD. Of 14 patients with a ratio greater than 2.5 at that time, only 2 developed grade II-IV and 12 grade O-I GVHD (p less than 0.001). In the 11 patients developing grade II-IV GVHD, the T4/T8 ratio decreased to values less than 2.5 before the first clinical symptoms of GVHD in 9; it coincided in one and occurred later in another patient. Thus, early monitoring of the T4/T8 ratio can distinguish patients at risk of developing grade II-IV GVHD.
Expression of human B cell-associated antigens on leukemias and lymphomas: a model of human B cell differentiation
Authors: Anderson KC , Bates MP , Slaughenhoupt BL , Pinkus GS , Schlossman SF , Nadler LM 
Published: October 2019

Abstract
A series of monoclonal antibodies that define B cell restricted and associated antigens was utilized in an attempt to characterize tumors of B lineage and to relate these tumors to B cell differentiative stages. Antigens that were previously shown to be B cell restricted on normal B lymphocytes were similarly expressed only on B cell malignancies. In contrast, antigens that were B cell associated were also found on tumors of other lineages. Moreover, on the basis of cell surface phenotypes, tumors of B cell origin were divided into three major subgroups, which corresponded to the level of differentiation of the malignant tumor cell: pre-B cell stage (non-T acute lymphoblastic leukemia and chronic myelocytic leukemia in lymphoid blast crisis); the mid-B cell stage (chronic lymphocytic leukemia, poorly differentiated lymphomas); and secretory B cell stage (large cell lymphomas and plasma cell tumors). A hypothetical model is derived that relates the malignant B cell to its normal cellular counterpart on the basis of cell surface expression of this panel of B cell-restricted and B cell- associated antigens.
Autoantibodies against platelet glycoprotein Ib in patients with chronic immune thrombocytopenic purpura
Authors: Woods VL Jr , Kurata Y , Montgomery RR , Tani P , Mason D , Oh EH , McMillan R 
Published: October 2019

Abstract
The present studies provide direct evidence that some patients with chronic immune thrombocytopenic purpura (ITP) have autoantibodies reactive with platelet glycoprotein Ib ( GPIb ). Microtiter wells coated with a monoclonal antibody that recognized GPIb were reacted with either platelet extract or a control cell extract. After washing and incubating with test plasma, well-bound IgG was quantitated using radioactive anti-IgG. When compared to plasma from normal subjects, plasma from 3 of 106 patients with chronic ITP had significantly increased quantities of IgG bound to microtiter wells reacted with platelet extracts. Negative results were obtained with the remaining 103 patients with chronic ITP and 59 patients with a variety of other platelet disorders. Plasma from two of the three positive patients precipitated a protein from 125I-surface-labeled platelet extract with a molecular weight similar to GPlb . One of the three patients with anti- GPlb antibody also had demonstrable autoantibodies to the platelet glycoprotein llb / llla complex.
Prolongation of sickle cell survival by dimethyl adipimidate is compromised by immune sensitization
Authors: Guis MS , Lande WM , Mohandas N , Pennathur-Das R , Preisler H , Lubin BH , Mentzer WC 
Published: October 2019

Abstract
The effect of dimethyl adipimidate (DMA), an amino-reactive crosslinking reagent with demonstrated antisickling properties in vitro, on the survival of 51Cr-labeled autologous sickle cells was evaluated in five adult males with sickle cell anemia. The survival of cells pretreated with 5 mmol/L DMA (pH 7.4), normal (t1/2 28–33 days) in four subjects and near-normal (t1/2 20 days) in the fifth, was considerably longer than that usually observed in sickle cell disease. In fact, the effect of DMA on the survival of sickle cells in vivo equals or exceeds that of any other agent tested to date. In three subjects, the survival of a second infusion of DMA-treated red cells was much shorter (t1/2 1.8, 3, 4.5 days) than in the initial study. An antibody was detected in the serum of these subjects that was directed to DMA-treated red cells. Modification of the immunogenicity of treated cells will be required before further consideration of DMA for use in the therapy of sickle cell anemia.
Human hepatoma cells secrete single chain factor X, prothrombin, and antithrombin III
Authors: Fair DS , Bahnak BR 
Published: October 2019

Abstract
The human hepatoma cell line, Hep G2, was analyzed for the ability to synthesize and secrete several coagulation proteins. Using specific radioimmunoassays, factor X, prothrombin, and antithrombin III were present in 8-day culture supernatants at 62, 405, and 1,220 ng/mL, respectively. Factor IX was not detected, either in supernatants or in cell extracts. Intrinsically labeled factor X was secreted as a single- chain polypeptide of 66,000 daltons, as measured by sodium dodecylsulfate-polyacrylamide gels under nonreduced and reduced conditions. Immunoblots of Hep G2 supernatants and normal human plasma also indicate the presence of single-chain factor X. These findings support the hypothesis of a postsecretion proteolytic cleavage of factor X into the two-chain form. Prothrombin and antithrombin represented their plasma protein counterparts structurally, with molecular weights of 73,000 and 61,000, respectively. Secreted factor X, prothrombin, and antithrombin III were biologically active, as determined in coagulation or chromogenic assays, and all three activities were neutralized by monospecific antibodies. Vitamin K increased the quantity of prothrombin secreted by twofold, without affecting the rate of secretion over a five-day culture period, and had an apparent transient inhibitory effect on secretion of antithrombin III. Warfarin caused a three to fourfold decrease in the rate and quantity of secreted prothrombin, but did not affect intracellular concentrations. The intracellular and extracellular concentrations and rate of secretion of antithrombin III were not modulated by warfarin. These data suggest that the Hep G2 cell line may provide a useful model for assessing the regulation of biosynthesis and secretion of human coagulation proteins.
The response of human neutrophils to a chemotactic tripeptide (N-formyl- methionyl-leucyl-phenylalanine) studied by microcinematography
Authors: Maher J , Martell JV , Brantley BA , Cox EB , Niedel JE , Rosse WF 
Published: October 2019

Abstract
A quantitative microcinematographic technique for the measurement of cellular motion in response to chemical influences is described. The data are analyzed by using a magnetic digitizer connected to a computer, permitting comparison of several characteristics of such motion. When human granulocytes are placed in a gradient of formyl- methionyl-leucyl-phenylalanine (fMLP) (concentration 10(-6)-10(-8) mol/L) against buffer, the motion of the cells is increased in velocity (chemokinesis) and is directed toward the chemoattractant, as measured by the orientation of the vector of motion. This directionality is confirmed by positive values for the McCutcheon index and analysis of directed linear displacement. Concentrations of fMLP below 10(-9) mol/L did not result in chemokinesis or chemotaxis, presumably due to insufficient stimulus. Concentrations of 10(-6) mol/L fMLP and greater resulted in marked stimulation of the cell surface but reduced directionality and velocity of motion compared with cells in a more optimal gradient. Motion of the unstimulated cells tended to be ortholinear , and this was not increased by the presence of a gradient of fMLP. Hence, as previously shown, the Random Walk analysis, which does not give weight to the direction of motion, is not useful in the analysis of the response of these cells to a chemotaxin in this system.
Beta O-39 thalassemia gene: a premature termination codon causes beta- mRNA deficiency without affecting cytoplasmic beta-mRNA stability
Authors: Humphries RK , Ley TJ , Anagnou NP , Baur AW , Nienhuis AW 
Published: October 2019

Abstract
The function of a beta O-thalassemia globin gene with a premature termination codon at position 39 was studied in tissue culture cells using plasmid expression vectors. The thalassemic globin gene was isolated by molecular cloning from the bone marrow DNA of an Italian patient with severe thalassemia. Sequences upstream of the normal beta- globin gene and the beta O-39 globin gene were removed to 127 nucleotides (nt) 5′ to the start site of transcription, thereby eliminating uncharacterized DNA sequences but preserving promoter function. To create a hybrid gene differing from the normal by only the single nt change in codon 39, the truncated 5′ end of the beta O-39 gene was recombined with the 3′ end of the normal gene. The beta O-39 substitution resulted in a 6–14-fold reduction in cytoplasmic RNA accumulation in transfected monkey kidney or HeLa cells. This decrease in mRNA did not appear to be due to instability, as the beta-mRNA present 24–36 hours after transfection was stable for up to 24 hours in the presence of actinomycin D. In the presence of actinomycin D, the globin mRNA precursor disappeared, suggesting that globin gene transcription had been effectively blocked. We also examined a second globin mRNA with a premature termination codon; this RNA that arises from incorrect splicing of the transcript of a beta + -24 thalassemia gene was as stable as the correctly spliced species. Thus, the presence of a premature termination codon does not necessarily alter cytoplasmic mRNA stability, nor does cytoplasmic instability account for the quantitative deficiency of beta-globin mRNA. Our observations suggest that a premature termination codon alters intranuclear stability and/or nuclear to cytoplasmic transport of the beta-globin mRNA.
TdT-positive acute leukemia with monocytoid characteristics: clinical, cytochemical, cytogenetic, and immunologic findings
Authors: Cuttner J , Seremetis S , Najfeld V , Dimitriu-Bona A , Winchester RA 
Published: October 2019

Abstract
Thirteen patients with acute leukemias that were difficult to classify by the use of cytochemical staining and terminal deoxyribonucleotidyl transferase (TdT) activity are reported. The phenotype of the leukemic cells was characterized by the presence of mature or early monocyte lineage antigens and intense Ia antigen expression detected by monoclonal antibodies, terminal deoxytransferase activity, and cytochemical features, including both Sudan black B and periodic acid- Schiff activity. The mean age of this group of patients was 60 years. Five patients had leukemia occurring after chemotherapy or radiotherapy of a prior malignant disease, and two patients had a refractory anemia prior to development of acute leukemia. These patients had a low response rate to chemotherapy. This series of leukemia appears to form a distinct nosologic entity, representing a leukemic transformation among early cells of the monocyte lineage, resulting in a predominant neoplastic cell that is less mature than either the French-American- British M4 acute myelomonocytic leukemia or M5 acute monoblastic leukemia. The presence of terminal deoxytransferase activity was interpreted as indicating the primitive state of the cells in the differentiation sequence, rather than as implying any significance with respect to lineage.
Characterization of immature T cell subpopulations in neonatal blood
Authors: Griffiths-Chu S , Patterson JA , Berger CL , Edelson RL , Chu AC 
Published: October 2019

Abstract
A series of monoclonal antibodies directed against T cell differentiation antigens was used to identify circulating T cells in normal human neonates. Twenty-five cord blood samples, taken after cesarean or vaginal delivery, and 16 venous blood samples from normal adult controls were examined using monoclonal antibodies in an indirect immunofluorescence technique. The percentage of circulating OKT3 positive (pan-T cell) cells was significantly lower in the neonatal blood (52.8%) compared with the adult controls (74.9%) (P less than .001). Of the cord mononuclear cells, 58% showed reactivity with OKT10 (common thymocyte antigen) compared with only 7% in adult controls (P less than .001). The helper:suppressor T cell ratio was lower in cord blood (1:2) as compared with 1:3 for adult blood (P less than .005) as observed in these studies. These figures reflect the presence of a significant population (25%) of immature T cells in cord blood that expresses simultaneously both helper (OKT4) and suppressor (OKT8) phenotypes. Twenty-four percent of the T cells in cord blood also expressed OKT6 antigen (cortical thymocyte), a feature not found in adult blood. Double-labeling studies characterized a previously undescribed blood T cell phenotype, which was simultaneously OKT6 and OKT3 (pan-T cell) positive; of the cells reactive with OKT3, 43% also were positive with OKT6. This study reveals the presence of immature populations of T cells in normal human neonatal blood exhibiting phenotypes characteristic of normal developing thymocytes and a previously undescribed cell phenotype.
The beta-adrenergic receptor adenylate cyclase complex of Rauscher murine erythroleukemia cells and its response to erythropoietin-induced differentiation
Authors: Sytkowski AJ , Kessler CJ 
Published: October 2019

Abstract
Rauscher murine erythroleukemia cells, grown continuously in vitro, undergo erythroid differentiation in response to the hormone erythropoietin. Therefore, they serve as an important model system with which to examine critical biochemical aspects of this developmental process. Intact, uninduced Rauscher cells possess a functional beta- adrenergic receptor-adenylate cyclase complex. The adrenergic agonists, isoproterenol, epinephrine, and norepinephrine, exhibited activation constants (Kact) of 0.1, 0.5, and 20 mumol/L, respectively. Thus, the beta-receptor-cyclase complex of Rauscher cells is apparently one of the most sensitive of all erythroid cells reported thus far. The epinephrine-stimulated cyclic adenosine monophosphate (cAMP) response was inhibited by propranolol, alprenolol, and hydroxybenzylpindolol, with inhibition constants (KI) of 3.8, 2.2, and 0.1 nmol/L, respectively. Using [125I]-iodohydroxybenzylpindolol as ligand, uninduced Rauscher cells were shown to possess 1,100 receptors/cell, with an equilibrium dissociation constant (KD) of 400 pmol/L. Erythropoietin, but not dimethylsulfoxide, induction caused a specific increase in receptor density to 3,300/cell on differentiating Rauscher cells. This is the first demonstration of membrane receptor regulation by erythropoietin that may be important in the complex interplay of hormonal effects during erythropoiesis.
Characterization of erythropoietin produced by IW32 murine erythroleukemia cells
Authors: Choppin J , Lacombe C , Casadevall N , Muller O , Tambourin P , Varet B 
Published: October 2019

Abstract
IW32 is a recently described murine erythroleukemia cell line that produces an erythropoietic factor similar to erythropoietin by in vivo and in vitro bioassays and without species specificity. Biochemical characteristics of IW32 erythropoietic factor and sheep or mouse plasma erythropoietins were compared. Murine colonies derived from erythroid colony-forming units (CFU-E) in plasma clot culture were used as the bioassay system. Both IW32 erythropoietic factor and sheep plasma erythropoietin were stable in the pH range of 3 to 10, after exposure to denaturing agents (8 mol/L urea, 4 mol/L guanidine hydrochloride, 1% sodium dodecyl sulfate), to a reducing agent (0.1 mol/L 2- mercaptoethanol) and to an oxidizing agent (5 mmol/L sodium metaperiodate). Only the combination of 0.1 mol/L 2-mercaptoethanol and 1% sodium dodecyl sulfate resulted in a significant loss of activity. IW32 erythropoietic factor and murine plasma erythropoietin were similarly precipitated by ethanol and ammonium sulfate. IW32 erythropoietic factor eluted as a single major peak after gel exclusion chromatography, with an estimated molecular weight of 45,000 daltons. Results were identical using supernatants from cultures in the presence of and absence of fetal calf serum. The supernatant of IW32 cells cultured without serum induced erythroid colonies after seven days on normal human bone marrow nonadherent mononuclear cells cultured in serum-free conditions. All these results made it very likely that IW32 cells produce an authentic erythropoietin. This cell line would be very useful for the study of murine erythropoietin.