bluuebunny/crossref_metadata_2025_split huggingface dataset:
Diphenylhydantoin-induced pure red cell aplasia
Authors: Dessypris EN , Redline S , Harris JW , Krantz SB 
Published: October 2019

Abstract
The pathogenesis of diphenylhydantoin-induced pure red cell aplasia was investigated in the case of a 32-year-old man who developed pure red cell aplasia while he was under treatment with diphenylhydantoin. The patient's serum IgG purified from serum drawn at the time of diagnosis suppressed normal allogeneic marrow colony-forming (CFU-E) and burst- forming (BFU-E) and autologous blood BFU-E growth in vitro only in the presence of diphenylhydantoin. This IgG-diphenylhydantoin complex had no effect on CFU-GM growth in vitro. Normal IgG or patient's IgG purified from serum drawn after the remission of red cell aplasia had no effect on erythroid colony formation in vitro in the presence of diphenylhydantoin. The IgG-diphenylhydantoin complex exerted no direct cytotoxic effect on normal marrow erythroblasts, CFU-E, and BFU-E, nor did it interfere with the action of erythropoietin on marrow erythroblasts. These studies suggest that diphenylhydantoin-induced red cell aplasia is immunologically mediated through an IgG inhibitor, which requires the presence of the drug to suppress erythroid colony formation in vitro. This inhibitor seems to exert its effect on erythroid progenitors at or beyond the stage of differentiation of CFU- E, but not on erythroblasts.
Regulation of heme synthesis in erythroid cells: hemin inhibits transferrin iron utilization but not protoporphyrin synthesis
Authors: Ponka P , Schulman HM 
Published: October 2019

Abstract
The inhibition of delta-aminolevulinic acid (ALA) synthase activity by heme is commonly thought to regulate the overall rate of heme synthesis in erythroid cells. However, since heme inhibits erythroid cell uptake of iron from transferrin, we have tested the hypothesis that in reticulocytes heme regulates its own synthesis by controlling the cellular acquisition of iron from transferrin rather than by controlling the synthesis of ALA. We found that hemin added to reticulocytes in vitro inhibits not only the total cell incorporation of 59Fe from transferrin but also the incorporation of [2–14C]-glycine and transferrin-bound 59Fe into heme. However, hemin did not inhibit [2 –14C]-glycine incorporation into protoporphyrin. Furthermore, cycloheximide, which increases the level of non-hemoglobin heme in reticulocytes, also inhibited [2–14C]-glycine into heme but not into protoporphyrin. With high concentrations of ferric pyridoxal benzoylhydrazone (Fe-PBH), which, independent of transferrin and transferrin receptors, can be used as a source of iron for heme synthesis in reticulocytes, significantly more iron is incorporated into heme than from saturating concentrations of Fe-transferrin. This suggests that some step (or steps) in the pathway of iron from extracellular transferrin to protoporphyrin limits the overall rate of heme synthesis in reticulocytes. In addition, hemin in concentrations that inhibit the utilization of transferrin-bound iron for heme synthesis has no effect on the incorporation of iron from Fe-PBH into heme. Our results indicate that in reticulocytes heme inhibits and controls the utilization of iron from transferrin but has no effect on the enzymes of porphyrin biosynthesis and ferrochelatase. This mode of regulation of heme synthesis may be a specific characteristic of the hemoglobin biosynthetic pathway.
The effect of 5-azacytidine and its analogues on blast cell renewal in acute myeloblastic leukemia
Authors: Motoji T , Hoang T , Tritchler D , McCulloch EA 
Published: October 2019

Abstract
Blast cells from patients with acute myeloblastic leukemia were exposed to 5-azacytidine (5-aza) and its analogues 5-aza 2′-deoxycytidine (5- aza-dr) and 6-azacytidine (6-aza). Simple negative exponential survival curves were obtained for the three drugs, but the sensitivity varied; 5- aza-dr was most toxic, 6-aza was least toxic, and 5-aza was intermediate. Colonies surviving drug exposure were replated; 5-aza and 5-aza-dr were found to increase secondary plating efficiency, whereas 6- aza was inactive. The findings provide indirect evidence for a role for DNA methylation in the regulation of blast cell self-renewal.
The monoclonal antibodies alpha S-HCL 1 (alpha Leu-14) and alpha S-HCL 3 (alpha Leu-M5) allow the diagnosis of hairy cell leukemia
Authors: Schwarting R , Stein H , Wang CY 
Published: October 2019

Abstract
To define cell surface antigens associated with hairy cell leukemia (HCL), and to gain better insight into the origin of this disease, we developed monoclonal antibodies against spleen cells of a patient with this disease. Although none of these antibodies alone proved specific for the leukemic cells, two of them, designated alpha S-HCL 1 (alpha Leu-14) and alpha S-HCL 3 (alpha Leu-M5) were found to be valuable in the diagnosis of HCL when used in combination. alpha S-HCL 1 recognizes an antigen associated with greater than 95% of B cells in the peripheral blood. Biochemical analysis identified this antigen as a single polypeptide chain with a molecular weight of 150,000 daltons (150 kilodaltons). alpha S-HCL 1 expression on hairy cells is markedly increased when compared with normal B lymphocytes isolated from peripheral blood, tonsils, and spleens. alpha S-HCL 3 reacts with an antigen present on hairy cells but also on monocytes, macrophages, in a lower density on neutrophils, and a small percentage (less than 2%) of lymphocytes. The antigen recognized by alpha S-HCL 3 is composed of a non-covalently linked biomolecular complex of 90 and 150 kilodaltons. Since the HCL 3 antigen was not detectable on other lymphomas of either T or B cell type, the co-expression of S-HCL 1 and S-HCL 3 on hairy cells is a unique marker for this disease.
Drug-induced endocytosis of neonatal erythrocytes
Authors: Matovcik LM , Junga IG , Schrier SL 
Published: October 2019

Abstract
The erythrocytes of the newborn infant have many properties that distinguish them from those of adults, and their membranes are also different from those of adult erythrocytes. We compared the ability of adult and neonatal RBCs to undergo endocytosis on exposure to drugs. Using a quantitative method, we showed that neonatal erythrocytes undergo a greater degree of endocytosis than do adult RBCs in response to primaquine, vinblastine, and chlorpromazine, and are sensitive to lower concentrations of the drugs. Some forms of drug-induced endocytosis are red cell age-dependent; when RBCs were separated by density gradient centrifugation, the membranes of the younger, less dense populations of both the neonatal and adult RBCs were capable of more extensive internalization than those of the denser, older RBCs. Neonatal RBCs of a given density undergo more endocytosis than do adult RBCs of the same density, suggesting that the membrane of the neonatal RBC is less stable and capable of more of the reorganization reflected in endocytosis than is the adult RBC membrane.
Cell-bound autologous immunoglobulin in erythrocyte subpopulations from patients with sickle cell disease
Authors: Green GA , Rehn MM , Kalra VK 
Published: October 2019

Abstract
Previously, we have demonstrated a parallel between most-dense (bouyant density) sickle erythrocyte subpopulations and most-dense aged normal red cells in the organization of membrane components in the intact cell. The present study has addressed the possibility that a corresponding similarity may exist between most-dense sickled red cell subpopulations and aged normal erythrocytes in the development of membrane protein components that function as receptors for autologous immunoglobulin (Ig). Autologous IgG retained by density-fractionated erythrocytes has been estimated by a nonequilibrium 125I-protein A (Staphylococcus aureus) binding assay. Results show that most-dense sickle cell fractions contain more (2.7-fold and 1.8-fold, P less than .005) cell-bound IgG in comparison to younger sickle erythrocyte fractions sedimenting at low density. Parallel findings were obtained after similar analyses of normal (homozygous-A) erythrocyte fractions. Detection of the presence of specific IgG was also carried out by direct binding of fluorescein isothiocyanate-conjugated anti-human IgG to density-separated red cell fractions followed by analyses of the fluorescent cell populations by flow cytometry. Results showed significantly higher levels of IgG bound to most-dense (12.1% +/- 2.5% and 8.8% +/- 0.5%-) sickle red cell subpopulations (P less than .005) in comparison to younger sickle erythrocyte fractions sedimenting at low densities (3.8% +/- 0.32% and 4.7% +/- 1.6% IgG-positive red cell subpopulation). These results indicate that some of the same membrane changes that occur at about 120 days in normal red cells are also apparent in the chronologically younger (life span in vivo, ten to 40 days) sickle erythrocyte. The increased retention of IgG by most-dense irreversibly sickled cell-enriched fractions in comparison to least- dense reversibly sickled cells or pre-irreversibly sickled erythrocyte fractions, suggests that alterations in the topography of the sickle cell membrane during the transformation in vivo to the most-dense irreversibly sickled cell morphology may produce the unmasking of cryptic antigenic sites. In addition, these findings may indicate that opsonization of specific erythrocyte subpopulations may play a role in the pathophysiology of sickle cell disease.
Bone marrow transplantation for acute nonlymphocytic leukemia in first remission: analysis of prognostic factors
Authors: Bostrom B , Brunning RD , McGlave P , Ramsay N , Nesbit M Jr , Woods WG , Hurd D , Krivit W , Kim T , Goldman A 
Published: October 2019

Abstract
Prognostic factors were reviewed retrospectively for 39 children and adults aged 1 to 40 years (median 14 years) with acute nonlymphocytic leukemia (ANLL) who attained a first remission and underwent bone marrow transplantation from November 1976 to July 1983. The preparation regimen for transplantation was cyclophosphamide (60 mg/kg/d for two days) followed by total body irradiation (either 750 cGy single dose at 26 cGy/min, n = 37, or 1,320 cGy fractionated at 10 cGy/min, n = 2). Twenty-three patients are surviving disease free with a median followup of three years. The three-year estimated disease-free survival is 55% +/- 17% (+/- 2 SE). Five patients have relapsed from 92 to 756 days after transplantation for an estimated relapse rate of 21% +/- 18%. Two factors, the white blood cell (WBC) count and the French-American- British (FAB) classification at leukemia diagnosis were found to be of prognostic importance. Patients with a WBC of less than 20,000/microL at diagnosis had a three-year estimated disease-free survival of 74% +/- 18% v 26% +/- 24% for those with a WBC of greater than or equal to 20,000 (P = .008). The estimated relapse rate was 6% +/- 12% for patients with a WBC at diagnosis less than 20,000 v 53% +/- 38% for patients with a WBC at diagnosis of greater than or equal to 20,000 (P = .01). Patients with myeloid morphology at diagnosis (FAB M1,2,3) had an estimated relapse rate of 9% +/- 12% v patients with monocytoid morphology (FAB M4,5a) whose estimated relapse rate was 58% +/- 44% (P = .05). Our data suggest that a high WBC count at poor prognostic factors for patients with ANLL who undergo bone marrow transplantation in first remission after conditioning with cyclophosphamide plus total body irradiation.
A new abnormal variant of spectrin in black patients with hereditary elliptocytosis
Authors: Lecomte MC , Dhermy D , Solis C , Ester A , Feo C , Gautero H , Bournier O , Boivin P 
Published: October 2019

Abstract
Seven black patients with mild hereditary elliptocytosis (HE) from five unrelated families were studied. The erythrocytes of these patients exhibited an abnormal thermal sensitivity (between 45 degrees C and 47 degrees C instead of 49 degrees C). An important defect of spectrin dimer self-association was detected in two ways: (1) the proportions of spectrin dimer (SpD) extracted from membranes at 4 degrees C under low ionic strength conditions were increased between 25% and 56% (normal value 15% +/- 2%); (2) the spectrin dimer----tetramer conversion in solution were defective with an association constant value between 0.4 and 2.4 X 10(5) M-1 for a normal value of 6 +/- 0.4 X 10(5) M-1. Spectrin (Sp) from HE patients and normal volunteers (32 black and 22 white subjects) was submitted to limited tryptic digestion, followed by one- or two-dimensional separation of the peptides. Peptide patterns of crude Sp from all seven HE patients exhibited a marked and reproducible decrease in 80,000-dalton peptide (previously identified as the dimer- dimer interaction domain of the alpha-chain) and a concomitant appearance of a novel 65,000-dalton peptide. A minor fragment at 28,000 daltons was also decreased. Tryptic digestion of HE spectrin dimer and tetramer (SpT), isolated after the SpD self-association procedure in solution, revealed modifications (decrease in the 80,000-dalton peptide and presence of a 65,000-dalton peptide) predominantly in HE SpD when peptide patterns of HE SpT were quite similar to control SpT patterns. Immunoblots with anti-alpha-chain antibodies revealed that the 65,000- dalton peptide derived from the alpha-chain. Kinetic studies of Sp digestion showed that the 65,000-dalton peptide did not result from further digestion of a 74,000 intermediate and was not a precursor of 46,000- to 50,000-dalton peptides. These results show a new structural defect of Sp-alpha-chain, associated with a defective Sp dimer self- association in HE.
Preferentially expressed genes in chronic myelogenous leukemia
Authors: Mars WM , Florine DL , Talpaz M , Saunders GF 
Published: October 2019

Abstract
The predominant circulating cells in chronic myelogenous leukemia (CML) morphologically resemble normal myeloid precursors; however, certain characteristics indicate the two are not identical. Approximately 88% of the patients with clinically typical CML present with a cytogenetic abnormality known as the Philadelphia chromosome (Ph1). Additionally, the leukocyte alkaline phosphatase (LAP) value is decreased in CML. To investigate if there are selected genes expressed in the CML cell population, poly(A+)RNA from a chronic-phase, Ph1-positive CML patient was used for construction of a complementary DNA (cDNA) library. Recombinant clones representing moderately to abundantly transcribed sequences were selected by annealing [32P]-cDNA transcribed from homologous RNA to the library sequences and assessing radioactivity in the hybrids. From an initial 729 colonies, 417 (57.2%) displayed a hybridization signal more intense than controls, indicating these recombinant plasmids contained sequences homologous to moderately or highly expressed RNAs from this particular patient. Screening of the 417 clones--utilizing 32P-cDNAs derived from normal human placenta, an acute myelomonocytic leukemia (AMML), and two other CML samples--was used to select clones likely to represent sequences preferentially expressed in CML. Sixteen recombinants were initially selected that repeatedly failed to display hybridization with the placenta and AMML- derived probes. Further analysis of eight of these clones indicated that six contain sequences preferentially expressed in CML. One clone, C-A3, has been studied with 63 different RNA samples. This sequence is found to be highly expressed in peripheral blood cells from the chronic phase of both Ph1-positive and Ph1-negative CML as well as in a Ph1- positive acute myelogenous leukemia (AML). Expression is reduced in lymphoblastic crisis of CML (L BC-CML) and essentially absent in myeloblastic crisis of CML (M BC-CML). While preliminary, the results suggest that this probe may be useful as an aid in diagnosing Ph1- negative CML and in distinguishing M BC-CML from L BC-CML and Ph1- positive AML.
The anticoagulant mechanism of action of heparin in contact-activated plasma: inhibition of factor X activation
Authors: McNeely TB , Griffith MJ 
Published: October 2019

Abstract
The effects of heparin on the activation of blood coagulation factors IX and X in contact-activated plasma were determined in the present study. In the presence and absence of 0.5 U/mL heparin, the amounts of factor IX that were cleaved 30 minutes after the addition of calcium and phospholipid to plasma exposed to glass (ie, contact activated) were essentially identical. In the absence of heparin, however, the plasma clotting time was between three and four minutes, while in the presence of heparin, the clotting time was approximately 40 minutes. More factor IXa was inhibited by antithrombin III in the presence of heparin than in its absence, but factor IXa levels sufficient for factor X activation appeared to be present in the heparinized plasma. Neither an increase in factor Xa nor a decrease in factor X was detected, however, in heparinized plasma. We conclude that the step in the intrinsic pathway of coagulation that is inhibited in the presence of heparin is at the level of factor X activation.
Surface membrane expression by human blood leukocytes and platelets of decay-accelerating factor, a regulatory protein of the complement system
Authors: Nicholson-Weller A , March JP , Rosen CE , Spicer DB , Austen KF 
Published: October 2019

Abstract
The decay-accelerating factor (DAF), an integral membrane protein of approximately 75,000 mol wt that regulates the stability of the C3 convertases of the classical and alternative complement pathways, was initially isolated from normal erythrocyte stroma and used to prepare a polyclonal antiserum. Previously, anti-DAF antiserum has been used to immunoprecipitate DAF from surface-labeled normal erythrocytes and to document the deficiency of DAF on the surface of erythrocytes from patients with paroxysmal nocturnal hemoglobinuria, a condition in which erythrocytes express abnormal sensitivity to complement-mediated lysis. DAF has now been demonstrated by cytofluorography with anti-DAF F(ab')2 and fluoresceinated second antibody to be present on the surface of resting polymorphonuclear leukocytes (PMN), monocytes, lymphocytes, and platelets. Populations of PMN, monocytes, and platelets each exhibited a unimodal distribution of fluorescent staining, reflecting uniform cellular expression of DAF antigen, while the lymphocyte population had a skewed pattern of staining, indicating the heterogeneous expression of DAF antigen. For platelets, the shift in mean fluorescence channel observed with cytofluorographic analysis was minimal, but the presence of surface DAF on platelets was demonstrated by specific and saturable anti-DAF F(ab')2 binding. The DAF antigen, analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of dithiothreitol- reduced anti-DAF immunoprecipitates prepared from surface-labeled, isolated populations of cells, presented a single polypeptide chain of approximately 84,000 mol wt for PMN and 75,000 to 80,000 mol wt for monocytes, T and B lymphocytes, and platelets. Thus, the complement regulatory protein, DAF, is expressed on the surface of all major types of circulating blood cells from normal donors.
Arachidonic acid incorporation by cytoplasmic lipid bodies of human eosinophils
Authors: Weller PF , Dvorak AM 
Published: October 2019

Abstract
The presence of cytoplasmic lipid bodies in human eosinophils and the participation of these lipid bodies in the metabolism of arachidonic acid by human eosinophils have been studied. Lipid bodies, structures of roughly spherical shape and variable size within the cytoplasm, were identified with transmission electron microscopy by their shape and variable osmiophilia and by their lack of a limiting membrane. While generally absent from eosinophils of normal peripheral blood, lipid bodies were found in tissue eosinophils and in blood eosinophils from patients with eosinophilia. A role for lipid bodies in arachidonic acid metabolism was determined with eosinophils obtained from two eosinophilic patients. After incubation for 30 to 60 minutes with 3H- arachidonic acid, purified eosinophils took up 50% to 98% of the tritium label. By electron microscopic autoradiography, almost all tritium label was localized to lipid bodies. Only 3.6% of the cell- incorporated tritium label was free arachidonic acid, while 5.8% was neutral lipids and 66% was phospholipid. Thus, most of the tritiated arachidonic acid incorporated by human eosinophils was present in esterified form, predominantly as phospholipids, and almost all of the tritiated lipids were localized ultrastructurally to cytoplasmic lipid bodies. These results provide evidence that lipid bodies of human eosinophils have a role in the cellular metabolism of arachidonic acid.
Identification of human megakaryocyte coagulation factor V
Authors: Nichols WL , Gastineau DA , Solberg LA , Mann KG 
Published: October 2019

Abstract
Specific monoclonal and polyclonal antibody reagents and a double antigen indirect immunofluorescence microscopy technique were used to visualize coagulation factor V in human bone marrow. Marrow aspirates were smeared directly on glass slides, or washed and cytospun onto glass slides, or processed and plated into a plasma/methylcellulose cell culture system. Morphologically identifiable colonies of megakaryocytes, erythrocytes, granulocytes, or monocytes/macrophages were removed from 14- to 18-day marrow culture dishes by micropipette and streaked onto glass slides. Smears of marrow cell preparations were air-dried, fixed, washed, and incubated sequentially with primary IgG antibody reagents and with secondary anti-IgG antibody reagents conjugated with either fluorescein or rhodamine. Preparations were examined and photographed through a microscope suitably equipped for two-color fluorescence and phase contrast analysis. Cells of megakaryocytic lineage were identified by their immunofluorescent reactivity with murine monoclonal antibody HP1–1D, specific for human platelet plasma membrane glycoprotein IIb/IIIa (GP IIb/IIIa), or by their immunofluorescent reactivity with monoclonal or polyclonal antibodies specific for von Willebrand factor (vWF) or for platelet factor 4 (PF4). Coagulation factor V in bone marrow was detected by simultaneous immunofluorescent staining with polyclonal burro anti- human factor V antibody or with a panel of murine monoclonal anti-human factor V antibodies. The double antigen immunofluorescence staining technique, incorporating appropriate controls, revealed that coagulation factor V was principally located in marrow cells simultaneously identified as megakaryocytes by antibodies to GP IIb/IIIa, vWF, or PF4. The specific immunofluorescence of factor V in megakaryocytes and platelets was eliminated when excess purified factor V antigen was preincubated with anti-factor V antibody. Our observations establish the presence of human megakaryocyte coagulation factor V, confirm the presence of human platelet factor V, and indicate that human megakaryocyte/platelet coagulation factor V is a lineage- associated protein.