bluuebunny/crossref_metadata_2025_split huggingface dataset:
Recombinant scinderin, an F-actin severing protein, increases calcium- induced release of serotonin from permeabilized platelets, an effect blocked by two scinderin-derived actin-binding peptides and phosphatidylinositol 4,5-bisphosphate
Authors: Marcu MG , Zhang L , Nau-Staudt K , Trifaro JM 
Published: October 2019

Abstract
In response to vessel injury or exposure to different substances, platelets undergo activation which consists of shape changes, formation of cellular pseudopodia, aggregation, and secretion. These dramatic changes are accompanied by cycles of actin depolymerization and polymerization. Previous work has shown the presence in platelets of gelsolin and scinderin, two Ca(2+)-dependent F-actin severing proteins. Recent published evidence suggests that scinderin is a component of the exocytotic machinery in chromaffin cells. The present work describes the preparation of recombinant scinderin and peptides Sc-ABP1 and Sc-ABP2 with sequences corresponding to two actin-binding sites of scinderin. Recombinant scinderin and peptides Sc-ABP1 and Sc-ABP2 were tested for their effects on Ca(2+)-induced serotonin release from digitonin permeabilized platelets. The results indicated that recombinant scinderin potentiates Ca(2+)-evoked serotonin release, an effect blocked in the presence of Sc-ABP1, Sc-ABP2, exogenous gamma-actin, or the addition of phosphatidylinositol 4,5-bisphosphate (PIP2). In the presence of a mismatched peptide (MMP) the potentiating effect of recombinant scinderin was not affected. Moreover, Sc-ABP1, Sc-ABP2, and gamma-actin inhibited Ca(2+)-induced release of serotonin in the absence of recombinant scinderin, suggesting an inhibition of platelet endogenous scinderin. MMP was ineffective under these conditions. The results suggest that F-actin disassembly, perhaps at a specific site, is required for platelet secretion and that scinderin might be an important component of the exocytotic machinery in platelets.
Allogeneic marrow transplantation for refractory anemia: a comparison of two preparative regimens and analysis of prognostic factors
Authors: Anderson JE , Appelbaum FR , Schoch G , Gooley T , Anasetti C , Bensinger WI , Bryant E , Buckner CD , Chauncey TR , Clift RA , Doney K , Flowers M , Hansen JA , Martin PJ , Matthews DC , Sanders JE , Shulman H , Sullivan KM , Witherspoon RP , Storb R 
Published: October 2019

Abstract
From 1990 to 1993 we performed a prospective study of busulfan (16 mg/kg) and cyclophosphamide (120 mg/kg) in 30 patients with refractory anemia (RA) undergoing related (n = 17) or unrelated (n = 13) donor marrow transplantation. Nineteen patients survive disease free (63% 3-year actuarial disease-free survival [DFS]) and no patient relapsed. These results were compared to those of 38 historical controls with RA treated with cyclophosphamide and total body irradiation, of whom 22 are disease-free survivors and 1 relapsed. After correcting for significant variables between the two treatment groups, we found no statistically significant difference in outcome based on preparative regimen. Combining data from these 68 patients plus 2 additional patients with RA treated before 1993 with busulfan and cyclophosphamide, we identified four variables independently associated with improved survival: younger age, shorter disease duration, lower neutrophil count pretransplant, and lower hematocrit pretransplant. We also found that 15 patients 40 to 55 years of age had a 46% 3-year actuarial DFS and 26 patients receiving unrelated or mismatched related donor marrow had a 50% 3-year actuarial DFS. We conclude that there does not appear to be any significant difference in outcome based on preparative regimen in this patient population. In addition, allogeneic bone marrow transplantation may be a reasonable approach to therapy of RA early after diagnosis. However, whether early intervention with transplantation prolongs survival over that expected without transplantation cannot be ascertained with certainty from available data.
Reactive oxygen intermediates cause rapid release of the interleukin-1 decoy receptor from human myelomonocytic cells
Authors: Sambo P , Fadlon EJ , Sironi M , Matteucci C , Introna M , Mantovani A , Colotta F 
Published: October 2019

Abstract
Free radicals play an important role in inflammation. We found that reactive oxygen intermediates (ROI) inhibit interleukin-1beta (IL- 1beta) binding on human myelomonocytes. Production of superoxide anion (O2-) by Xanthine (X) and Xanthine-Oxidase (XO) or NADPH caused a reduction (48% +/- 15% in 25 experiments) in the IL-1beta binding of polymorphonuclear cells (PMN) and monocytes that was inhibited by superoxide dismutase (SOD). Hydrogen peroxide (H2O2) was only active on monocytes and this effect was prevented by catalase. O2(-)-induced loss of IL-1beta binding on PMN reached half maximum at 5 minutes and peaked after 30 minutes. The reduction of IL-1beta binding was due to reduction of IL-1beta receptors (R) on PMN surface without any change in affinity. ROI-induced reduction of surface IL-1R was not caused by receptor internalization, but rather by the release of a soluble form (45 kD) of the type II decoy R. The action of ROI on IL-1 binding was selective because major histocompatibility complex class I, CD18 and CD16 were unaffected. The O2(-)-induced release of IL-1 decoy R was not affected by protein synthesis inhibitors, but was partially blocked by protease inhibitors. Release of the IL-1 type II decoy R might represent one mechanism by which ROI antagonize and limit the proinflammatory effects of IL-1.
Clinical features and studies of erythropoiesis in Israeli Bedouins with congenital dyserythropoietic anemia type I
Authors: Tamary H , Shalev H , Luria D , Shaft D , Zoldan M , Shalmon L , Gruinspan A , Stark B , Chaison M , Shinar E , Resnitzky P , Zaizov R 
Published: October 2019

Abstract
Congenital dyserythropoietic anemia (CDA) type I is a rare macrocytic anemia of unknown etiology. In the present study, we redefined the clinical and laboratory picture of CDA type I, some of its pathogenic aspects, and the association with thalassemia-like features in 20 patients, all of whom belong to one Bedouin tribal group and are probably descended from a common ancestor. In each case ultrastructural studies of bone marrow (BM) erythroblasts showed the classic morphological findings of CDA type I. Serological tests for CDA type II were negative. The clinical picture was variable, but mostly benign. Some patients displayed elevated hemoglobin A2 levels or high ratio of alpha- to non-alpha- globin. However, neither family studies nor complete sequence analysis of the beta-globin was compatible with beta- thalassemia. Increased erythropoiesis was manifested by a high number of BM erythroid burst-forming units. Serum erythropoietin was also elevated. BM flow cytometry studies demonstrated arrest of erythroid precursors in the S phase of the cell cycle. The ultrastructural morphological features of the erythroid precursors, showing peripheral chromatin condensation, suggest apoptosis. Additional studies are indicated to define the molecular basis of this disease.
Expression of A-myb, but not c-myb and B-myb, is restricted to Burkitt's lymphoma, sIg+ B-acute lymphoblastic leukemia, and a subset of chronic lymphocytic leukemias
Authors: Golay J , Luppi M , Songia S , Palvarini C , Lombardi L , Aiello A , Delia D , Lam K , Crawford DH , Biondi A , Barbui T , Rambaldi A , Introna M 
Published: October 2019

Abstract
The A-myb gene encodes a transcription factor that is related both functionally and structurally to the v-myb oncogene. Following our observations that A-myb is expressed in a restricted subset of normal mature human B lymphocytes, with the phenotype CD38+, CD39-, slgM-, we have now investigated the pattern of A-myb expression in neoplastic B cells representating the whole spectrum of B-cell differentiation and compared it to that of c-myb and B-myb. In a panel of 32 B-cell lines, A-myb was very strongly expressed in most Burkitt's lymphoma (BL) cell lines, but weak or negative in 2 pre-B acute lymphoblastic leukemia (ALL), 4 non-Hodgkin's lymphoma (NHL), 6 Epstein-Barr virus- immortalized lymphoblastoid cell lines, and 6 myeloma lines. Protein expression paralleled that of the RNA. We have also investigated A-myb expression in 49 fresh cases of B leukemias. Among 24 ALL, 6 were of the null and 11 of the common type and all these were negative for A- myb expression; on the other hand, all 7 B-ALL cases (slg+), as well as one fresh BL case with bone marrow infiltration, expressed A-myb. A-myb was undetectable in 4 prolymphocytic leukemias (PLL) but was strongly expressed in 5/20 (25%) of chronic lymphocytic leukemia (CLL) samples. In the latter A-myb did not correlate with phenotype or clinical stage. Finally, we have studied the progression of one case of CLL into Richter's syndrome and have found that the Richter's cells expressed about 25-fold less A-myb RNA than the CLL cells from the same patient. The pattern of c-myb and B-myb was clearly distinct from that of A-myb. C-myb and B-myb were expressed in all neoplastic groups, except in CLL cells. Thus, A-myb expression, unlike that of c-myb and B-myb, is restricted to a subset of B-cell neoplasias (in particular BL and slg+B- ALL) representative of a specific stage of B-cell differentiation. This expression may in part reflect expression of A-myb by the normal germinal center B cells that are the normal counterpart of these transformed B cells. The data presented strongly support a role for this transcription factor in B-cell differentiation and perhaps in B- cell transformation in some neoplasias.
Exposure of human CD34+ cells to human immunodeficiency virus type 1 does not influence their expansion and proliferation of hematopoietic progenitors in vitro
Authors: Kaushal S , La Russa VF , Gartner S , Kessler S , Perfetto S , Yu Z , Ritchey DW , Xu J , Perera P , Kim J , Reid T , Mayers DL , St. Louis D , Mosca JD 
Published: October 2019

Abstract
The susceptibility of highly purified human CD34+ cells to monocytotropic (Ba-L) and lymphotropic (A018-post) strains of human immunodeficiency virus-1 (HIV-1) was examined. Liquid cultures initiated with fresh immunomagnetically purified CD34+ cells using the K6.1 CD34 monoclonal antibody (MoAb) (K6.1/CD34+) were positive for HIV expression 2 weeks after exposure to HIV-1 Ba-L. These cells were initially greater than 90% CD34+ and had undetectable monocyte contamination by flow-cytometric staining and side-scatter analyses, respectively, and undetectable T-cell contamination by CD3 polymerase chain reaction (PCR) analysis. However, secondary CD34+ liquid cultures reselected from the primary liquid cultures 24 hours after HIV exposure by panning with the ICH3 CD34 MoAb (ICH3/CD34+) and maintained for an additional 14 days were negative for HIV expression. The ICH3-unbound cells were positive for both spliced and unspliced HIV RNA when exposed to HIV-1 Ba-L, and were DNA PCR positive when exposed to either monocytotropic or lymphotropic HIV-1. To further test that CD34+ cells were not infectible by HIV-1, we exposed K6.1/CD34+ cells continuously to HIV-1 in a culture system capable of maintaining and expanding primitive CD34+ cells. HIV-exposed K6.1/CD34+ cells proliferated and expanded as efficiently as uninfected cultures. However, when reselected magnetically using the K6.1 CD34 MoAb after expansion for 7 days, bound K6.1/CD34+ cells were again negative for HIV-1 expression, whereas unbound cells were positive for HIV-1 expression. These findings suggest that a sequential CD34+ cell-selection process, in which the two selections are separated by a brief culture period, can yield a population of CD34+ cells that are not infected with HIV-1. This process may be useful in the design of stem or progenitor cell- based transplantation therapies for HIV infection.
Are there functional gap junctions or junctional hemichannels in macrophages?
Authors: Alves LA , Coutinho-Silva R , Persechini PM , Spray DC , Savino W , Campos de Carvalho AC 
Published: October 2019

Abstract
The existence of functional gap junctions in migratory cells of the immune system is a controversial issue. In this report, we have focused on one particular cell type, namely the macrophages, because connexin- 43, a protein that forms gap junctions, has been described in peritoneal macrophages and a macrophage cell line (J774), by Northern and Western blot analysis. To test whether these cell types expressed functional gap junctions, we assayed dye coupling by intracellular injection of Lucifer Yellow. We observed that nonstimulated macrophages are not coupled among themselves and did not form functional gap junctions with an epithelial cell line, which expresses functional gap junctions formed by connexin-43. Dye coupling was also not detected between macrophages previously activated by lipopolysaccharide or interferon-gamma. We further examined the presence of functional coupling using the more sensitive technique of dual whole cell patch- clamp, and again, did not find electrical coupling between macrophages, consistent with the dye microinjection data. We also examined the possible presence of hemigap junction channels activated by extracellular adenosine triphosphate (ATP) using a dye uptake assay and the whole cell patch-clamp technique. Conditions expected to close gap junction hemichannels (exposure to octanol and low intracellular pH) did not decrease ATP-induced Lucifer Yellow uptake, whereas conditions expected to increase hemichannel opening either did not affect ATP permeabilization (dibutyryl adenosine monophosphate) or decreased it (zero extracellular CA+2). Finally, in experiments using resident macrophages derived from conexin-43 knockout mice, we observed ATP induced dye uptake. Our experimental data thus indicate that macrophages in vitro do not form functional gap junctions and that the permeability pathway activated by extracellular ATP is not formed by a hemigap junction channel.
Extremely high avidity association of Fe(III) with the sickle red cell membrane
Authors: Shalev O , Hebbel RP 
Published: October 2019

Abstract
Red blood cells (RBCs) from patients with sickle cell anemia and thalassemia carry abnormal accumulations of molecular Fe(III) at the cytosol/membrane interface. The avidity of the red cell membrane for this iron has not been defined. Using open ghost membranes prepared from sickle RBC, we examined the ability of membrane-associated Fe(III) to resist removal by 15 chelators representing a 40-log range of affinities for Fe(III). Efficacy of chelators was compared with literature values for their idealized affinity for iron as represented by the cummulative stability constant (beta n), their effective stability constant reflecting affinity under biologic conditions (Keff), and an indicator of their ability to chelate Fe(III) in the presence of an insoluble phase of iron (Ksol). Deferoxamine, a very high affinity chelator having log beta n = 30.6, was found to be the lowest affinity chelator able to remove RBC membrane Fe(III). Regardless of chelator beta n, only those agents able to preserve log Keff > or = 12 were able to do so, indicating that the membrane's effective avidity for Fe(III) is on the order of 10(12). Additional confirmation that membrane avidity for Fe(III) is extremely high is found in the observation that only chelators having log Ksol > 0 were effective. Potential physiologic iron chelators in cytoplasm of pathologic red cells are unable to prevent or reverse iron accumulation on the membrane because they do not have sufficiently high affinity for iron. These data argue that RBC membrane Fe(III) is truly pathologic.
Induction of negative hematopoietic regulators by neurokinin-A in bone marrow stroma
Authors: Rameshwar P , Gascon P 
Published: October 2019

Abstract
The tachykinins are a family of neuropeptides that share a common carboxyl terminus. Substance P (SP) and neurokinin-A (NK-A) are derived from the preprotachykinin l gene. Although SP and NK-A can bind to either NK-1, NK-2, or NK-3 receptors (R), they have preferences for NK- 1R and NK-2R, respectively. We have reported that SP stimulates erythroid (E) (burst-forming unit [BFU]-E and colony-forming unit [CFU]- E) and myeloid (CFU-granulocyte-macrophage [GM]) progenitors partly through the induction of growth factors. We have now investigated the hematopoietic effects of NK-A using short-term bone marrow (BM) cultures and found that NK-A (10(-7) to 10(-12) mol/L) inhibits CFU-GM proliferation but stimulates erythroid progenitors. Release of soluble factors by the stroma appears to mediate the inhibition because direct contact with the stroma was not required. We have found that NK-A, through NK-2-like receptors induces increased levels of macrophage inflammatory protein-1 alpha (MIP-1 alpha) and transforming growth factor-beta (TGF-beta) (transcriptional and posttranscriptional) in BM stroma. Clonogenic assays with NK-A (10(-9) mol/L) and either anti-MIP- 1 alpha or anti-TGF- beta 1 indicate that these cytokines partly contribute to the inhibition, suggesting that these two negative hematopoietic regulators exert part of the inhibition by NK-A on CFU- GM. The findings of two closely related neuropeptides, derived from the same gene, exerting opposite effects on myeloid colonies suggest that neuropeptides, by themselves could be important factors in hematopoietic regulation.
The effect of in vitro human immunodeficiency virus infection on dendritic-cell differentiation and function
Authors: Canque B , Rosenzwajg M , Camus S , Yagello M , Bonnet ML , Guigon M , Gluckman JC 
Published: October 2019

Abstract
CD1a+ dendritic cells (DC) differentiate from a major population of nonadherent CD13(hi)lin-cells that appear when human cord blood CD34+ hematopoietic progenitor cells are cultured with stem-cell factor, granulocyte/macrophage (MA) colony-stimulating factor, and tumor necrosis factor-alpha (TNF-alpha) for 5 days. CD13hilin- cells, which also comprise MA and granulocyte precursors, are CD4+ and can thus be targets of human immunodeficiency virus (HIV). Low replication was noted when these day 5 cells were infected with lymphotropic HIV-1LA1 (p24: < or = 4 ng/mL on day 8 postinfection [PI]), while high virus production occurred with MA-tropic HIV-1Ba-L, HIV-1Ada, or HIV-1-m-n. (p24: 50 to > or = 1,000 ng/mL). Strong cytopathicity (CPE) was then observed in nonadherent cells as in adherent MA. However, FACS analysis on day 7 PI showed that HIV did not affect differentiation of DC that survived CPE: apart from CD4 downmodulation related to HIV production, overall expression of CD40, CD80, and CD86 costimulatory molecules, and of HLA-DR, was unchanged relative to controls. At that time, the capacity of DC from HIV-infected cultures to stimulate the mixed leukocyte reaction was only altered less than 10-fold. Immunocytochemistry on day 7 PI showed that most HIV-infected cells were included in syncytia that were stained by anti-CD1a, anti-S100, and anti-CD14 antibodies, indicating that syncytia consisted of DC and cells of the MA lineage. Polymerase chain reaction analysis of FACS- sorted CD1a+ cells confirmed that they harbored then HIV DNA. Viral DNA was also detected in CD1a+ DC from noninfected cultures that had been exposed to HIV only after sorting. Therefore, we examined whether in infected cultures DC precursors were infected at the onset or if virus spread later from other infected cells to differentiated DC. This was answered by showing that, 24 hours postexposure to HIV, viral DNA was preferentially detected in day 5 sorted CD13hilin-versus CD13hilin- cells, and that it was found in the CD1a+ progeny of CD13(hi)lin-cells 48 hours later. In addition, HIV replication did not affect myeloid clonogenic progenitors in day 0 to day 7 PI cultures, although viral DNA was detected in colony-forming unit-granulocyte/macrophage (CFU-GM)/CFU-M colonies derived from day 3 and 7 PI cultures. Thus, precursors of DC and their progeny are susceptible to HIV in vitro, but, apart from CPE, the effect of virus production on DC differentiation or function is limited.
Interleukin-7 is a critical growth factor in early human T-cell development
Authors: Plum J , De Smedt M , Leclercq G , Verhasselt B , Vandekerckhove B 
Published: October 2019

Abstract
Highly purified human CD34+ fetal liver stem cells differentiate to mature T cells when seeded in vitro into isolated fetal thymic lobes of severe combined immunodeficient (SCID) mice followed by fetal thymus organ culture (FTOC). Here, this chimeric human-mouse FTOC was used to address the role of interleukin-7 (IL-7) and of the alpha chain of the IL-7 receptor (IL-7R alpha) in early human T-cell development. We report that addition of either the monoclonal antibody (MoAb) M25, which neutralizes both human and mouse IL-7, or the MoAb M21, which recognizes and blocks exclusively the human high-affinity alpha-chain of the IL-7R, results in a profound reduction in human thymic cellularity. Analysis of lymphoid subpopulations indicates that a highly reduced number of cells undergo maturation from CD34+ precursor cells toward CD4+CD3-CD1+ progenitor cells and subsequently toward CD4+CD8+ thymocytes. Our results reveal a critical role for IL-7 during early human thymocyte development, and may explain the absence or highly reduced levels of T cells in patients with X-linked SCID. The molecular defect in these patients has been shown to be a mutation in the gamma chain of the IL-2R. Although this gamma chain is not only present in the IL-2R, but also forms an essential part of other cytokine receptors, including IL-4, IL-7, IL-9, IL-13, and IL-15, the T- cell defect in these patients can be explained by the fact that IL-7 is not able to transduce its signal by the molecular defect of the common gamma (gamma c) chain and that IL-7 is indispensable for T-cell development.
Venous thromboembolism associated with double heterozygosity for R506Q mutation of factor V and for T298M mutation of protein C in a large family of a previously described homozygous protein C-deficient newborn with massive thrombosis
Authors: Brenner B , Zivelin A , Lanir N , Greengard JS , Griffin JH , Seligsohn U 
Published: October 2019

Abstract
It is remarkable that certain patients with heterozygous protein C (PC) deficiency manifest venous thromboembolism (VTE), whereas others, particularly those belonging to families with homozygous PC deficiency, remain asymptomatic. The goals of the present study of a family, in which the proband had homozygous PC deficiency, were to identify members with and without VTE, to determine the mutation causing PC deficiency, and to search for the R506Q mutation of factor V (FV) causing activated PC resistance. Heterozygosity for a T298M mutation in exon 9 of the PC gene was found in the father of the homozygous proband who died of massive thrombosis. Based on analysis of a three- dimensional molecular model of PC, we speculate that this mutation causes type I deficiency due to disruption of packing of hydrophobic side chains and loss of an H-bond between Q184 and T298. Forty-six family members were examined for the T298M mutation by polymerase chain reaction (PCR) amplification of exon 9 and restriction analysis using Mae III and for the FV R506Q mutation by PCR amplification of exon 10 and restriction analysis using Mnl I. VTE was observed in five of 11 members who were heterozygous for both PC and FV mutations. In contrast, VTE was not observed for the PC mutation in 13 heterozygotes who had normal FV, including the parents of the deceased proband, 10 heterozygotes for the FV mutation who had normal PC, and 12 individuals bearing neither mutation. These observations extend recent evidence of an increased thrombotic risk conferred by the coexistence of heterozygous PC deficiency and heterozygous activated PC resistance and support the paradigm in which hereditary thrombophilia is often a multigenic disease.