bluuebunny/crossref_metadata_2025_split huggingface dataset:
F-actin content of neonate and adult neutrophils
Authors: Hilmo A , Howard TH 
Published: October 2019

Abstract
We utilized flow cytometric analysis of NBDphallacidin-stained cells to measure F-actin content, expressed as fluorescent channel numbers, and we compared the microfilamentous cytoskeletal organization in neutrophils from healthy neonates (36 to 38 weeks gestational age) and adults. Basal F-actin content in neonate cord blood neutrophils is higher than that of adults. The elevation is intrinsic to the cell and not related to parturition because basal F-actin content of neonatal cells obtained by venipuncture (days 1 to 8 of age) is also elevated (38 +/- 10, N = 15) when compared to adults (21 +/- 7.0, N = 27). The rate of N-formyl-methionyl-leucyl-phenylalanine (fMLP)-induced actin polymerization is similar in adult and neonatal neutrophils and is maximal by 30 to 45 seconds at 25 degrees C. Adult, neonatal cord, and neonatal venipuncture neutrophils increase F-actin content to a similar extent following 0.5 mumol/L fMLP activation (52 +/- 18, N = 27; 58.7 +/- 18, N = 18; 51.5 +/- 7.0, N = 15, respectively). However, the relative increase in F-actin content following fMLP activation is much greater in adult (2.37-fold) than neonatal neutrophils (1.28-fold). This difference is due to the elevated basal F-actin content of neonatal cells. Comparison of distribution of F-actin content among basal, neonatal neutrophils reveals two subpopulations of neutrophils with respect to F-actin content--approximately 25% with F-actin content similar to that of adult neutrophils and 75% with F-actin content greater than that of adult cells. Following fMLP activation, the subpopulations disappear. The results suggest that abnormalities in microfilamentous cytoskeletal organization of neonatal cells may, in part, be responsible for decreased chemotactic response of neonatal neutrophils.
Differences in coagulant and fibrinolytic activities of cultured human endothelial cells derived from omental tissue microvessels and umbilical veins
Authors: Speiser W , Anders E , Preissner KT , Wagner O , Muller-Berghaus G 
Published: October 2019

Abstract
Large vessel and microvascular endothelial cells were compared in their capacity to synthesize and secrete coagulant and fibrinolytic factors. Human omental tissue microvascular endothelial cells (HOTMEC) and human umbilical vein endothelial cells (HUVEC) were isolated, grown to confluency under identical conditions, and studied in primary cultures. After an incubation period of 12 hours in serum-free medium, the conditioned medium of confluent HOTMEC contained 100-fold higher levels of tissue plasminogen activator (tPA) antigen than that of HUVEC. The conditioned media as well as the lysates of both cell types did not contain any free tPA activity, but the free plasminogen activator inhibitor capacity was found intracellularly as well as extracellularly. Although von Willebrand factor was detected in both cell types by immunofluorescence, measurable amounts were only found in HUVEC using an enzyme-linked immunosorbent assay. The kinetics of protein C activation by thrombin on the surface of once-passaged cells were identical for HOTMEC and HUVEC. The present study indicates that cultivated HOTMEC produce larger quantities of tPA than HUVEC do, possess smaller amounts of von Willebrand factor than HUVEC do, and express thrombomodulin for protein C activation as effectively as HUVEC.
Immunochemical characterization of fibrinogen, fibrin I, and fibrin II in human thrombi and atherosclerotic lesions
Authors: Bini A , Fenoglio J Jr , Sobel J , Owen J , Fejgl M , Kaplan KL 
Published: October 2019

Abstract
Arterial thrombi and atherosclerotic lesions were analyzed immunochemically and examined histologically. The extent of in vivo proteolytic cleavage of the amino-terminal end of fibrinogen by thrombin and plasmin was determined and quantitated by specific radioimmunoassays. The samples were treated with cyanogen bromide (CNBr), and the total amount of fibrinogen and fibrin-derived protein was determined as NDSK, the NH2-terminal disulfide knot of fibrinogen. Thrombin-releasable fibrinopeptides A and B were used to quantitate fibrinogen and fibrin I. Previous plasmin cleavage of the B beta chain was inferred from the amount of B beta 1–42 and B beta 15–42 in undigested NDSK. The results obtained in both acute and organized thrombi indicate that approximately 60% of the total protein (as determined by amino acid analysis) was fibrinogen-derived and that 70% to 80% of the fibrinogen-derived material was fibrin II. These findings support the hypothesis that fibrin II as distinct from fibrin I is the predominant component in a thrombus. In samples from normal and atherosclerotic aortas, fibrinogen-derived protein comprised less than 10% of the total protein. Samples from grossly normal aortas contained only fibrinogen and fibrin I. Fibrinogen concentration decreased and fibrin II concentration increased with increasing severity of the lesions, suggesting that increased fibrin II formation is associated with progression of atheromas.
Stimulation by cAMP of erythropoietin secretion by an established human renal carcinoma cell line
Authors: Sherwood JB , Burns ER , Shouval D 
Published: October 2019

Abstract
We used our recently reported stable, transformed human renal carcinoma cell line as a model system to study the role of 3′,5′-adenosine monophosphate (cAMP) in erythropoietin secretion. The erythropoietin produced by these cells is both biologically active and immunologically cross-reactive with purified native human hormone in our radioimmunoassay. Erythropoietin release by these renal carcinoma cells appears to be stimulated by cAMP as well as by the phosphodiesterase inhibitor 3-isobutyl-1-methyl-xanthine (MIX). The response to cAMP involves a rapid and enhanced release of hormone, which occurred within 30 minutes of exposure of the cells to the effector and continued for at least 4 hours. Intracellular erythropoietin was higher in the control cultures than in the cells treated with cAMP, suggesting that cAMP stimulates the release of a storage pool of hormone. The ability of cAMP and MIX to elicit the release of erythropoietin suggests that a cAMP-mediated mechanism is involved in the release of this hormone.
Sardinian delta beta zero-thalassemia: a further example of a C to T substitution at position -196 of the A gamma globin gene promoter
Authors: Ottolenghi S , Giglioni B , Pulazzini A , Comi P , Camaschella C , Serra A , Guerrasio A , Saglio G 
Published: October 2019

Abstract
Selective overexpression (50- to 100-fold) in adult erythroid cells of either G gamma or A gamma fetal globin gene is observed in hereditary conditions known as delta beta zero-thalassemia and hereditary persistence of fetal hemoglobin (HPFH). Recently, a C-T change at position -196 of an overexpressed A gamma globin gene from an Italian HPFH was hypothesized, on the basis of indirect evidence, to represent the cause of the functional defect. We now show that the same mutation is present in a different overexpressed A gamma-globin gene from a Sardinian patient with a different syndrome (delta beta zero- thalassemia). The Sardinian A gamma globin gene differs from both the HPFH and the normal A gamma globin gene at nucleotide 1,560 in the noncoding portion of the third exon, where an A is deleted. In addition, the mutant -196 A gamma-globin gene is linked to a normal beta globin gene in HPFH, and to a beta-thalassemic gene (beta 39CAG-TAG) in delta beta zero-thalassemia. These data strengthen the suggestion that -196 mutation is causally linked to the abnormal phenotype and raise the question of whether the same or multiple mutational events are responsible for the appearance of the -196 mutation in different syndromes.
Studies on the ultrastructure of fibrin lacking fibrinopeptide B (beta- fibrin)
Authors: Mosesson MW , DiOrio JP , Muller MF , Shainoff JR , Siebenlist KR , Amrani DL , Homandberg GA , Soria J , Soria C , Samama M 
Published: October 2019

Abstract
Release of fibrinopeptide B from fibrinogen by copperhead venom procoagulant enzyme results in a form of fibrin (beta-fibrin) with weaker self-aggregation characteristics than the normal product (alpha beta-fibrin) produced by release of fibrinopeptides A (FPA) and B (FPB) by thrombin. We investigated the ultrastructure of these two types of fibrin as well as that of beta-fibrin prepared from fibrinogen Metz (A alpha 16 Arg----Cys), a homozygous dysfibrinogenemic mutant that does not release FPA. At 14 degrees C and physiologic solvent conditions (0.15 mol/L of NaCl, 0.015 mol/L of Tris buffer pH 7.4), the turbidity (350 nm) of rapidly polymerizing alpha beta-fibrin (thrombin 1 to 2 U/mL) plateaued in less than 6 min and formed a “coarse” matrix consisting of anastomosing fiber bundles (mean diameter 92 nm). More slowly polymerizing alpha beta-fibrin (thrombin 0.01 and 0.001 U/mL) surpassed this turbidity after greater than or equal to 60 minutes and concomitantly developed a network of thicker fiber bundles (mean diameters 118 and 186 nm, respectively). Such matrices also contained networks of highly branched, twisting, “fine” fibrils (fiber diameters 7 to 30 nm) that are usually characteristic of matrices formed at high ionic strength and pH. Slowly polymerizing beta-fibrin, like slowly polymerizing alpha beta-fibrin, displayed considerable quantities of fine matrix in addition to an underlying thick cable network (mean fiber diameter 135 nm), whereas rapidly polymerizing beta-fibrin monomer was comprised almost exclusively of wide, poorly anastomosed, striated cables (mean diameter 212 nm). Metz beta-fibrin clots were more fragile than those of normal beta-fibrin and were comprised almost entirely of a fine network. Metz fibrin could be induced, however, to form thick fiber bundles (mean diameter 76 nm) in the presence of albumin at a concentration (500 mumol/L) in the physiologic range and resembled a Metz plasma fibrin clot in that regard. The diminished capacity of Metz beta-fibrin to form thick fiber bundles may be due to impaired use or occupancy of a polymerization site exposed by FPB release. Our results indicate that twisting fibrils are an inherent structural feature of all forms of assembling fibrin, and suggest that mature beta-fibrin or alpha beta-fibrin clots develop from networks of thin fibrils that have the ability to coalesce to form thicker fiber bundles.
Mediastinal lymphoma of clear cell type is a tumor corresponding to terminal steps of B cell differentiation
Authors: Moller P , Moldenhauer G , Momburg F , Lammler B , Eberlein-Gonska M , Kiesel S , Dorken B 
Published: October 2019

Abstract
This article reports eight primary mediastinal tumors occurring in young adults (19 to 43 years, mean 29.4 years), predominantly female (six of eight) adults. Most patients responded badly to aggressive therapy. Progression is presently noted in one patient; five patients died 10, 11, 13, 18, and 22 months after diagnosis. No patient developed leukemia. The tumors were highly proliferative, had a diffuse growth pattern, and comprised clear cells of variable size. They could not be classified histologically, but could, however, be immunohistologically characterized as B cell lymphomas. In all cases, the immunophenotype was LC+, cALLa-, CD19+, CD20+, CD21-, Ig (surface/cytoplasm)-, and PC-1+. In addition, the neoplastic cells exhibited variable defects in the expression of HLA-A,B,C and HLA-DR and inconstant expression of other B cell-restricted/associated antigens. This combination of immunophenotypical and clinical features suggests that the mediastinal clear cell lymphoma (MCCL) is a previously undescribed type of B cell lymphoma corresponding to the terminal steps of B cell differentiation.
Contrasting patterns of DNA strand breakage and ADP-ribosylation- dependent DNA ligation during granulocyte and monocyte differentiation
Authors: Khan Z , Francis GE 
Published: October 2019

Abstract
Previous studies have shown that structural changes in DNA, including the ligation of pre-existing DNA breaks and the opening and closure of new breaks, occur shortly after exposure of granulomonocytic precursors (CFU-GM) to granulocyte-macrophage colony stimulating activity (GM- CSA). Monocytic differentiation of CFU-GM is selectively inhibited by compounds known to inhibit the nuclear enzyme ADP-ribosyl transferase (ADPRT). Since this enzyme, which transfers ADP-ribose units to chromatin proteins, is known to activate DNA ligase, we attempted to determine whether ligation of one or both types of DNA break is required for monocytic differentiation. Breaks in DNA were examined using the nucleoid sedimentation technique in which DNA breaks cause loss of DNA supercoiling in nucleoids and concomitant changes in their sedimentation through neutral sucrose gradients. We here report that two distinct patterns of DNA strand breakage and ligation are associated with differentiation to the granulocyte and monocyte lineages. Monocytic inducers (phorbolester and vitamin D3) predominantly produce closure of pre-existing strand breaks, whereas granulocytic inducers (granulocyte colony stimulating activity, G-CSA; retinoic acid) cause opening and closure of new breaks. Only ligation of the pre-existing breaks is highly sensitive to inhibition by 3- methoxybenzamide (a potent ADPRT inhibitor), and only monocytic differentiation is impaired by addition of this compound. These findings suggest that DNA structural changes may be directly involved in granulocyte-macrophage switching.
Vitamin B12-responsive neonatal megaloblastic anemia and homocystinuria with associated reduced methionine synthase activity
Authors: Hallam LJ , Sawyer M , Clark AC , Van der Weyden MB 
Published: October 2019

Abstract
We present findings on an infant with neonatal megaloblastic anemia, homocystinuria, and neurologic dysfunction that included developmental delay and tonic seizures. There was no methylmalonic aciduria. Cyanocobalamin therapy was accompanied by complete hematologic and neurologic recovery, diminished homocystine excretion, and subsequently normal neurologic development. Cultured fibroblasts and lymphoblasts showed a reduced methionine synthase activity and a growth requirement for methionine. Cobalamin incorporation by the patient's lymphoblasts was normal, but the proportion of cellular methylcobalamin in the patient's lymphoblasts and fibroblasts were markedly reduced and that of adenosylcobalamin normal. The reduced methionine synthase activity was independent of assay reducing (thiol) conditions, but normal levels of activity accompanied culture of the patient's lymphoblasts in medium with markedly increased cobalamin concentration. The characteristics of the reduced methionine synthase of our patient differ significantly from that of the previously described infant with cobalamin E disease and suggest that genetic heterogeneity may characterize this mutation.
Correlation of drug-perturbed marrow cell growth kinetics and intracellular 1-B-D-arabinofuranosylcytosine metabolism with clinical response in adult acute myelogenous leukemia
Authors: Karp JE , Donehower RC , Dole GB , Burke PJ 
Published: October 2019

Abstract
To define the relationship between leukemic cell growth, intracellular metabolism of 1-B-D-arabinofuranosylcytosine (ara-C), and the clinical response to timed sequential induction therapy with ara-C in adult acute myelogenous leukemia (AML), growth kinetic and biochemical pharmacologic determinants were examined in AML bone marrow populations. Leukemic blasts from 45 previously untreated patients obtained prior to therapy were cultured in vitro in autologous pretreatment serum (APS) and in serum containing drug-induced humoral stimulatory activity (HSA). Cell populations cultured in HSA demonstrated both increased proliferation, as measured by both [3H]dThd incorporation into DNA and [3H]dThd leukemic blast labeling index, and greater [3H] ara-C leukemic blast labeling index relative to cells maintained in APS. HSA-cultured marrow cells from the 31 patients who achieved complete remission with ara-C-containing therapy demonstrated enhanced intracellular formation of ara-C 5′-triphosphate over three hours and retention of this active form during one subsequent hour in drug-free medium relative to cells maintained in APS. In contrast, cells from the 14 nonresponsive patients demonstrated no such HSA- induced increases in intracellular ara-C metabolism. These studies of human AML marrow cells identify behavior patterns of ara-C activation and net metabolism in the kinetically perturbed, proliferative state that may discriminate clinical sensitivity from clinical resistance to ara-C-based timed sequential therapy. Sensitive AML populations behave similarly to normal hematopoietic cohorts, with direct linkage of HSA- perturbed growth and pharmacologic parameters, while refractory cells demonstrate uncoupling of these determinants in the growth-stimulated state. These in vitro measurements may further serve as a template for prediction of clinical outcome to timed sequential therapy with ara-C, where both pharmacologic and cytokinetic determinants of response are intrinsic to the success of the designed drug scheduling.
The molecular basis of beta-thalassemia in Lebanon: application to prenatal diagnosis
Authors: Chehab FF , Der Kaloustian V , Khouri FP , Deeb SS , Kan YW 
Published: October 2019

Abstract
A study of the molecular lesions of beta-thalassemia in Lebanon revealed the presence of eight different mutations in 25 patients with Cooley's anemia. The IVS1 position 110 mutation predominated with a frequency of 62% and was almost invariably associated with Mediterranean chromosome haplotype I. Five other mutations commonly found in the Mediterranean area occurred with frequencies of 2% to 8%. In addition a G----C substitution in IVS1 position 5 (a lesion previously found in Chinese and Asian Indians) was demonstrated in a patient with Mediterranean haplotype IX. A new mutation at codon 29 was found in two other patients with haplotype II. The characterization of these beta-thalassemia mutations should allow the implementation of a prenatal diagnosis program in that country.
The regulatory role of interleukin 2-responsive T lymphocytes on human marrow granulopoiesis
Authors: Estrov Z , Roifman C , Mills G , Grunberger T , Gelfand EW , Freedman MH 
Published: October 2019

Abstract
The effect of recombinant interleukin 2 (IL2) on marrow CFU-C colony formation was evaluated to define the role for T lymphocytes in human marrow granulopoiesis. The colony-stimulating factor (CSA) used in our experiments was found to contain IL2. IL2 depletion from CSA resulted in a reduction in CFU-C colony proliferation. Addition of exogenous IL2 caused an increase in CFU-C colony numbers in a dose-dependent manner. This increase could be prevented by anti-Tac, a monoclonal antibody (MoAb) to the IL2 receptor. Moreover, anti-Tac in the absence of exogenous IL2 resulted in an overall decrease in colony numbers. Depletion of either adherent cells or T lymphocytes abolished the effect of IL2 and anti-Tac on colony growth. In the presence of IL2, re- addition of T lymphocytes to the T-depleted marrow or adherent cells to adherent cell-depleted marrow resulted in a significant increase in CFU- C colony numbers, whereas no significant effect was found when IL2- depleted CSA was used. Although T lymphocytes were not themselves essential for CFU-C colony growth, our studies indicate that IL2 and IL2-responsive T cells can regulate in vitro granulopoiesis.
Membrane receptors for interleukin 2 on hematopoietic precursors in chronic myeloid leukemia
Authors: Visani G , Delwel R , Touw I , Bot F , Lowenberg B 
Published: October 2019

Abstract
In this report we present data on the expression of IL2 receptors on chronic phase CML cells. Using an anti IL2 receptor monoclonal antibody (McAb aIL2r) in indirect immunofluorescence we found significant proportions (42.2% +/- 19.7 SD) of the CML cells (previously depleted of E rosetting T cells) to be IL2 receptor positive following incubation in suspension for 18 hours at 37 degrees C. Noninduced cells did not express IL2 receptors. After induction the aIL2r positive and negative cell subpopulations were sorted and analyzed separately for morphology, lineage specific cell surface markers, and clonogenic cell numbers. The IL2 receptor positive CML subpopulations mainly contained blast cells and monocytes and revealed reactivity with myeloid McAbs but not with T cell, B cell, platelet, or erythroid markers. Clonogenic cells (CFU-GEMM, BFUe, and CFU-GM) were selectively recovered from aIL2r positive CML cells and thus were IL2 receptor positive. The addition of recombinant IL2 (rIL2) to CFU-GM and BFUe cultures, in concentrations from 50 to 500 U/mL, did not influence the efficiency of colony formation. Binding of a radiolabeled IL2 preparation to the in vitro activated CML cells indicated the presence of low affinity receptors for IL2. In contrast to CML, normal human marrow cells were consistently aIL2r nonreactive. Thus, IL2 receptor inducibility is a characteristic feature of CML clonogenic cells, which they share with AML, but not with normal marrow progenitors. The role of IL2 receptors in the regulation of proliferation of CML cells requires further investigation.
Further studies of the secretory pathway in thrombin-stimulated human platelets
Authors: White JG , Krumwiede M 
Published: October 2019

Abstract
The pathway followed by secretory products stored in platelet alpha granules during the release reaction remains controversial. Tannic acid has been used in the present study as an electron-dense stain to follow the secretory process in thrombin-stimulated platelets. Preliminary experiments demonstrated that tannic acid precipitates fibrinogen, and binds osmium tetroxide to fibrinogen and fibrin strands. Examination of platelets fixed at short intervals after exposure to thrombin and incubated in solutions containing tannic acid revealed electron-dense deposits of osmium not apparent in resting platelets. Granules and lumina of channels making up the open canalicular system (OCS) were unstained in discoid cells. However, exposure to thrombin at concentrations of 1 to 5 U/mL for thirty seconds or more resulted in intense staining of alpha granules by osmium. Some granules communicated directly with dilated channels of the OCS, and several were frequently connected to the same canaliculus. The electron-dense substance in swollen granules and channels appeared to be in the process of extrusion through narrow or dilated openings of the OCS onto the platelet surface. Granule-to-granule fusion and formation of sealed vacuoles of fused granule products unstained by tannic acid-osmium were not observed. The findings support the concept that secretion by stimulated human platelets results from development of direct communications between granules and channels of the OCS and subsequent extrusion of products through channel pores to the surrounding medium.