bluuebunny/crossref_metadata_2025_split huggingface dataset:
Assessment of the hemostatic effectiveness of human platelets treated with aminomethyltrimethyl psoralen and UV A light using a rabbit ear bleeding time technique
Authors: Wagner SJ , Bardossy L , Moroff G , Dodd RY , Blajchman MA 
Published: October 2019

Abstract
The photochemical aminomethyltrimethyl psoralen (AMT), in conjunction with UV A light (UVA), has been shown to inactivate human immunodeficiency virus-1 and model viruses in platelet suspensions under conditions that have only a minimal effect on in vitro platelet properties. A rabbit ear bleeding time technique was used to assess the hemostatic effectiveness of human platelet suspensions treated with AMT/UVA. New Zealand White rabbits were made thrombocytopenic by a combination of irradiation and heterologous antirabbit platelet antiserum. Reticuloendothelial function in these rabbits was suppressed by the intravenous administration of ethyl palmitate. The hemostatic function of 1- and 5-day-old human platelet suspensions (14.5% plasma) that had been treated on day 1 with 40 micrograms/mL AMT and 24 kJ/m2 UVA (1 x UVA) was evaluated by measuring microvascular bleeding times after a standard incision. Comparable bleeding times were observed after infusion with both control and AMT/UVA-treated platelets stored for either 1 or 5 days. With the transfusion of AMT/1 x UVA-treated platelets stored for 5 days, the mean (+/- SD) bleeding time was 156.3 +/- 39.2 seconds (n = 10). With untreated platelets (no AMT/no UVA), stored for 5 days, the mean bleeding time was 189.2 +/- 36.4 seconds (n = 10). Neither AMT nor 1 x UVA treatment alone influenced the observed bleeding times. In contrast, the hemostatic effectiveness of human platelet suspensions was diminished if they were exposed to three times the standard UVA dose (72 kJ/m2) on day 1 and stored for 4 more days, regardless of whether AMT was present, with the mean bleeding time increasing to 442.2 +/- 122.6 seconds (n = 15, AMT present) or 396.0 +/- 45.9 seconds (n = 10, AMT absent). These results are consistent with data obtained from in vitro studies and indicate that virucidal AMT/1 x UVA treatment does not influence platelet hemostatic function. However, the final conditions to achieve these results must be carefully controlled.
Absence of reverse transcription-polymerase chain reaction detectable residual disease in patients with acute promyelocytic leukemia in long- term remission
Authors: Diverio D , Pandolfi PP , Biondi A , Avvisati G , Petti MC , Mandelli F , Pelicci G , Lo Coco F 
Published: October 2019

Abstract
Hybrid fusion genes are specific tumor markers of several leukemic subtypes. The use of reverse transcription-polymerase chain reaction (RT-PCR) to amplify chimeric cDNAs allows sensitive detection of the neoplastic clone for diagnostic and monitoring studies in these leukemias. Nonetheless, the clinical relevance of minimal residual disease (MRD) evaluation by PCR remains controversial. In this study, 9 patients (pts) with acute promyelocytic leukemia (APL) in long-term remission for 4 to 12 years were analyzed for the presence of MRD by RT- PCR amplification of the specific PML/RAR-alpha fusion gene. Seven pts had been treated with conventional chemotherapy (CHT) alone, 1 had undergone allogeneic bone marrow transplantation (BMT), and 1 autologous BMT as consolidation therapy after CHT. In 8 cases, the presence of the t(15;17) rearrangement could be documented in diagnostic BM specimens by cytogenetic and/or molecular analysis. A two- rounds “nested” RT-PCR assay with sensitivity levels of 1 in 10(5) was used to analyze BM samples collected at 32 to 141 months from the achievement of complete remission (CR). In no cases were residual PML/RAR-alpha transcripts detectable in these remission controls. All patients are in unmaintained CR at 48 to 154 months from CR and at 6 to 17 months from PCR evaluation. These results suggest that long-term survival of APL is associated with eradication of cells carrying the specific PML/RAR-alpha rearrangement, indicating that PCR negativity should be considered the therapeutic goal in these patients. Our findings further strengthen the clinical relevance of PCR monitoring studies in APL, as opposite to other leukemic subtypes (chronic myeloid leukemia and acute myeloid leukemia-M2) in which the prognostic significance of PCR evaluation is unclear.
Platelet activation and inhibition of malarial cytoadherence by the anti-CD36 IgM monoclonal antibody NL07
Authors: Alessio M , Greco NJ , Primo L , Ghigo D , Bosia A , Tandon NN , Ockenhouse CF , Jamieson GA , Malavasi F 
Published: October 2019

Abstract
The surface glycoprotein CD36 (GPIV) is known to mediate the adhesion of Plasmodium falciparum malaria-infected red blood cells and to be a receptor for extracellular matrix proteins such as collagen and thrombospondin. The murine monoclonal IgM antibody NL07, which is specific for CD36, has now been shown to also be a potent inhibitor of the adhesion of P falciparum malaria-infected red blood cells to C32 melanoma cells. Treatment of platelets with NL07 monoclonal antibody resulted in rapid degranulation, release of ATP and serotonin, increase in [Ca2+]i, and tyrosine phosphorylation of a substrate protein of 130 kD. In about one-half of the experiments, activation with NL07 resulted in the formation of small aggregates of 10 to 30 platelets, whereas in the other half of the experiments, large aggregates were seen similar to those induced by adenosine diphosphate (ADP) and these large aggregates could be converted to the small aggregates by ATP alpha S or by AP-2 or other antibodies against GPIIb and/or IIIa. Microaggregates of 2 to 5 platelets were seen with Glanzmann's platelets that constitutively lack GPIIb/IIIa. Aggregate formation was not seen with heat-treated serum, in the presence of anti C1q antibodies, or when using C5-, C8-, or C9-deficient human sera. Although activation of platelets with purified complement components results in a slow morphologic change without aggregation, involvement of CD36 results in rapid complement-mediated activation leading to formation of small aggregates that is largely independent of GPIIb/IIIa and that, under certain circumstances, proceeds to the formation of large ADP-dependent aggregates.
Transcriptional and posttranscriptional regulation of the expression of the erythropoietin receptor gene in human erythropoietin-responsive cell lines
Authors: Migliaccio AR , Jiang Y , Migliaccio G , Nicolis S , Crotta S , Ronchi A , Ottolenghi S , Adamson JW 
Published: October 2019

Abstract
With erythroid differentiation, committed progenitor cells acquire the ability to respond to erythropoietin (Epo). Epo interacts with target cells through the Epo receptor (Epo-R), whose expression is tightly regulated in a lineage-specific fashion. Epo-R expression is presumed to be progressively activated or repressed as cells progress along the erythroid or the myeloid pathway, respectively. Little is known of the mechanisms that underlie the erythroid-specific expression of the Epo-R gene. GATA-1, the major known transcription factor involved in Epo-R gene regulation, is not erythroid-specific. We have studied the regulation of the expression of the Epo-R gene in two related human Epo- responsive cell lines, UT-7 and UT-7 Epo. These lines express Epo-R at high levels because of amplification of the endogenous gene, which is apparently not rearranged. Treatment for 6 to 24 hours with the tumor promoter, phorbol myristate acetate (PMA), or 24 hours of growth factor starvation (Epo or granulocyte/macrophage colony-stimulating factor [GM- CSF]) decreased or increased the levels of Epo-R mRNA, respectively. In the case of growth factor starvation, the increase (approximately equal to threefold) in the level of Epo-R mRNA correlated directly with an increase in the rate of Epo-R gene transcription as measured by run-off assay. Both increases were observed as early as 3 hours after the growth factor was withdrawn and were reversible; levels of mRNA and transcription rates returned to baseline 3 hours after the cells were reexposed to growth factors. The changes in Epo-R expression after growth factor starvation were coordinated with changes in the level of expression of GATA-1 that were detected both at the mRNA and at the gene transcription level under these conditions (suggesting that GATA-1 was responsible for this upregulation). During PMA treatment, after a transient increase in Epo-R mRNA at 1 hour, a progressive decline in the level of Epo-R mRNA was observed; the level of Epo-R mRNA decreased by 50%, and fell below the level of detection by 6 and 24 hours, respectively. This decrement was explained in part by a fourfold reduction in the rate of gene transcription as well as a reduction (measured as levels of Epo-R mRNA in the presence of actinomycin D) in mRNA stability. The changes in transcription rate occurred in the absence of changes in the level of GATA-1 binding activity.(ABSTRACT TRUNCATED AT 400 WORDS)
Development and characterization of monoclonal antiplatelet autoantibodies from autoimmune thrombocytopenic purpura-prone (NZW x BXSB)F1 mice
Authors: Mizutani H , Engelman RW , Kurata Y , Ikehara S , Good RA 
Published: October 2019

Abstract
Male (NZW x BXSB)F1 (W/BF1) mice develop systemic autoimmunity involving autoantibodies, progressive thrombocytopenia, lupus nephritis, and degenerative coronary vascular disease with myocardial infarction. Platelet-associated IgG (PAIgG) on the platelet surface mediates platelet destruction by the reticuloendothelial system in the autoimmune thrombocytopenic purpura (ATP) of W/BF1 mice. Because the epitopes targeted in ATP by PAIgG have not been identifiable using serum from thrombocytopenic W/BF1 mice, we developed seven hybridomas secreting antiplatelet monoclonal antibodies (MoAbs) using splenocytes of thrombocytopenic W/BF1 mice. Epitopes recognized by three MoAbs were similar to those recognized by PAIgG, because eluted IgG from platelets of thrombocytopenic W/BF1 mice inhibited platelet binding by MoAbs in competitive micro-enzyme-linked immunosorbent assay. Hybridoma cells or purified Ig from the ascites of two clones (2A12 and 6A6), when injected into nude mice produced acute thrombocytopenia, elevated the levels of PAIgG, purpura, and megakaryocytosis. MoAbs of two clones also reacted with single-stranded DNA or double-stranded DNA, and one of these clones (4–13) bound to cardiolipin (CL) but was nonpathogenic in nude mice, suggesting that anti-CL and antiplatelet autoantibodies can be distinct. On immunoblotting analysis, antiplatelet MoAbs frequently bound a 100-Kd platelet protein. These MoAbs contribute to an understanding of the etiopathogenesis of ATP and the several antigens and autoantibodies involved.
Treatment of adult chronic autoimmune thrombocytopenic purpura with repeated high-dose intravenous immunoglobulin
Authors: Godeau B , Lesage S , Divine M , Wirquin V , Farcet JP , Bierling P 
Published: October 2019

Abstract
Intravenous (i.v.) infusions of Ig concentrates are an effective but expensive treatment for patients with autoimmune thrombocytopenic purpura (AITP). The optimal treatment protocol and the long-term results are uncertain, and the precise mechanism by which the platelet count increases is poorly understood. Twenty adult patients with chronic AITP were enrolled in a prospective study to compare the respective efficacy of two high-dose IVIgG induction regimens (1 g v 2 g/kg body weight) and the long-term effect of six 1 g/kg body weight i.v. IgG reinfusions. An initial response was observed in all 18 evaluable patients: the platelet count increased to a mean value of 251 x 10(9)/L (range 72 to 836 x 10(9)/L) and the mean pretreatment platelet count was multiplied by 14.6. No difference in efficiency was observed between the two i.v. IgG dosages. The degree of the platelet count increment correlated in both groups with the increase in the clearance of antibody-coated red blood cells, measured by an isotopic method, but not with the serum IgG elevation. Treatment was considered to have failed in 11 patients, 90 days after the last i.v. IgG reinfusion (D90), because the platelet counts were comparable with pretreatment values. In contrast, a complete response was observed at D90 in five patients (mean platelet count: 184 x 10(9)/L; range: 150 to 250 x 10(9)/L) and a partial response at D90 was obtained in the remaining two patients (platelet counts: 70 and 104 x 10(9)/L). Five of the 7 responders at D90 kept a platelet count above 50 x 10(9)/L during the entire follow-up period (mean 33 months; range: 5 to 66) with no further treatment; unfortunately, no clinical or biologic criteria were found to be predictive of the long-term response. This study shows that an i.v. IgG infusion regimen of 1 g/kg body weight could safely replace the classical 2 g/kg body weight dosage, at least in patients who do not have life-threatening thrombocytopenia. Moreover, repeated i.v. IgG reinfusion could be an alternative for AITP patients in whom splenectomy is contraindicated.
Lymphocytopenia as an unfavorable prognostic factor in patients with cytomegalovirus infection after bone marrow transplantation
Authors: Einsele H , Ehninger G , Steidle M , Fischer I , Bihler S , Gerneth F , Vallbracht A , Schmidt H , Waller HD , Muller CA 
Published: October 2019

Abstract
Sixty-three recipients of an allogeneic marrow transplant were screened for the occurrence of cytomegalovirus (CMV) infection and clinical parameters possibly predicting the development of CMV disease in a retrospective study. Blood and urine samples obtained from these patients were screened weekly after bone marrow transplantation (BMT) for the presence of CMV by polymerase chain reaction (PCR) and virus culture technique. Forty-six of the 63 patients studied were found to be CMV-positive by PCR technique in blood and urine samples at a median of 29 days after BMT. In 33 of these 46 patients, CMV could be cultured from urine samples and 16 of the 46 had culture-positive viremia. Twenty-eight of these 46 PCR-positive patients developed CMV disease. Whereas PCR assays showed an optimal negative predictive value and sensitivity for the development of CMV disease, their positive predictive value was 61% and could not be remarkably increased when culture-proven viruria (64%) and viremia (69%) were considered. Acute graft-versus-host disease (GVHD) grade 2 to 4 (P < .05), but not underlying disease, conditioning therapy, or GVHD prophylaxis, was associated with CMV infection. On day +49, a remarkable decrease (P < .001) in the lymphocyte count, as well as in the absolute number of CD4+, CD8+, and CD56+ lymphocytes, occurred only among the patients who later developed CMV disease. The decrease of all of these cell counts, but predominantly the CD4+ T cells, to less than 100/microL on day +49 after BMT showed a very high positive predictive value (100%) for the development of CMV disease in patients with PCR-proven viremia. Persisting CD4 lymphopenia after antiviral therapy was only observed in patients who finally died of CMV disease. Thus, immunophenotyping of the patients after BMT in addition to a highly sensitive virus detection assay might help to identify patients at high risk to develop CMV disease and indicate the need for additional adoptive immunotherapy.
Human eosinophil Charcot-Leyden crystal protein: cloning and characterization of a lysophospholipase gene promoter
Authors: Gomolin HI , Yamaguchi Y , Paulpillai AV , Dvorak LA , Ackerman SJ , Tenen DG 
Published: October 2019

Abstract
The Charcot-Leyden crystal (CLC) protein is a lysophospholipase expressed exclusively by eosinophils and basophils. During eosinophilic differentiation of eosinophil-committed cell lines, CLC steady state mRNA levels increase significantly. This increased expression is transcriptionally regulated during butyrate induction of an eosinophilic subline (C15) of the promyelocytic leukemia cell line HL- 60, as shown by nuclear run-on assays. The transcriptional start site of the CLC gene was identified 43 bp upstream of the 5′ end of the longest available cDNA sequence. The gene encoding CLC protein was cloned from a chromosome 19-specific library and a fragment overlapping the transcriptional start site was isolated and sequenced. Plasmid constructs (in the pXP2 luciferase expression vector) containing 411 and 292 bp of genomic sequence upstream of the CLC transcriptional start site directed reporter gene expression in transient transfections of HL-60-C15 cells, as well as other myeloid (U937) and nonmyeloid (HeLa and RPMI 8402) cell lines. However, the differential expression of the two CLC promoter constructs in these cell lines suggests that the -292 to -411 bp region of the promoter may confer some specificity for expression in the eosinophil lineage. The CLC promoter sequence contains two consensus GATA binding sites, a purine-rich sequence that presents potential binding sites for PU.1, a member of the ets family of genes, as well as sequences described in other myeloid-specific promoters. This is the first demonstration of a functional eosinophil promoter that could serve as a model for identifying DNA elements and trans-activating factors that regulate gene expression during the commitment and differentiation of the eosinophil lineage.
Compound heterozygosity for hemoglobin C and Korle-Bu: moderate microcytic hemolytic anemia and acceleration of crystal formation [corrected] [published erratum appears in Blood 1994 May 15;83(10):3105]
Authors: Nagel RL , Lin MJ , Witkowska HE , Fabry ME , Bestak M , Hirsch RE 
Published: October 2019

Abstract
We report here that compound heterozygosity for hemoglobin Korle-Bu (HbKB) and HbC (beta 6 Glu-->Lys) is associated with moderate chronic hemolytic anemia with microcytosis. To understand the pathogenesis of this syndrome, we have studied the effect of Hb Korle-Bu (KB = beta 73 Asp-->Asn) on the crystallization of HbC. We have previously established that fetal Hb (HbF) inhibits the crystallization of HbC. In contrast, HbS accelerates crystallization affecting the pathogenesis of SC disease. We now report on in vitro crystallization of mixtures of HbKB, HbC, and various amounts of HbF and the native hemolysate of a child who is a compound heterozygote for HbKB and HbC. At 6 months of age, the propositus' hemolysate contained 55% HbKB, 39% HbC, and 6% HbF. Crystal formed within 2 minutes compared with 30 minutes for the mixture of 40% HbC:60% HbS and with 180 minutes for 40% HbC:60% HbA. The morphology of the crystals formed was cubic, in contrast with the tetragonal crystals observed in CC and SC disease. Early crystals did not exhibit “sharp edges” until 45 minutes. Purified HbKB formed aggregates but not crystals after 24 hours. Isopycnic gradients showed that the KB/C compound heterozygotes have red blood cell (RBC) densities intermediate between the AC and CC phenotype and similar to SC disease. The surface residue beta 73, known to participate in areas of interaction of the deoxy HbS polymer, can now be assigned to areas of contact in HbC containing crystals. The hemolysis observed in the HbKB/C compound heterozygote is likely to be secondary to the acceleration of Hb crystallization. The microcytosis and increased RBC density is clearly the consequence of the presence of HbC, but the basis of the increased RBC pathology compared with AC trait, despite the low proportion of HbC (35% to 40%), remains to be elucidated.
Recombinant Miltenberger I and II human blood group antigens: the role of glycosylation in cell surface expression and antigenicity of glycophorin A
Authors: Ugorski M , Blackall DP , Pahlsson P , Shakin-Eshleman SH , Moore J , Spitalnik SL 
Published: October 2019

Abstract
Glycophorin A is a heavily glycosylated glycoprotein (1 N-linked and 15 O-linked oligosaccharides) and is highly expressed on the surface of human red blood cells. It is important in transfusion medicine because it carries several clinically relevant human blood group antigens. To study further the role of glycosylation in surface expression of this protein, four mutations were separately introduced into glycophorin A cDNA by site-directed mutagenesis. Each of these mutations blocks N- linked glycosylation at Asn26 of this glycoprotein by affecting the Asn- X-Ser/Thr acceptor sequence. Two of these mutations are identical to the amino acid polymorphisms found at position 28 in the Mi.I and Mi.II Miltenberger blood group antigens. The mutated recombinant glycoproteins were expressed in transfected wild-type and glycosylation- deficient Chinese hamster ovary (CHO) cells. When expressed in wild- type CHO cells and analyzed on Western blots, each of the four mutants had a faster electrophoretic mobility than wild-type glycophorin A, corresponding to a difference of approximately 4 Kd. This change is consistent with the absence of the N-linked oligosaccharide at Asn26. Each of the four mutants was highly expressed on the surface of CHO cells, confirming that, in the presence of normal O-linked glycosylation, the N-linked oligosaccharide is not necessary for cell surface expression of this glycoprotein. To examine the role of O- linked glycosylation in this process, the Mi.I mutant cDNA was transfected into the IdlD glycosylation-deficient CHO cell line. When the transfected IdlD cells were cultured in the presence of N- acetylgalactosamine alone, only intermediate levels of cell surface expression were seen for Mi.I mutant glycophorin A containing truncated O-linked oligosaccharides. In contrast, when cultured in the presence of galactose alone, or in the absence of both galactose and N- acetylgalactosamine, Mi.I mutant glycophorin A lacking both N-linked and O-linked oligosaccharides was not expressed at the cell surface. This extends previous results (Remaley et al, J Biol Chem 266:24176, 1991) showing that, in the absence of O-linked glycosylation, some types of N-linked glycosylation can support cell surface expression of glycophorin A. The glycophorin A mutants were also used for serologic testing with defined human antisera. These studies showed that the recombinant Mi.I and Mi.II glycoproteins appropriately bound anti-Vw and anti-Hut, respectively. They also demonstrated that these antibodies recognized the amino acid polymorphisms encoded by Mi.I and Mi.II rather than cryptic peptide antigens uncovered by the lack of N- linked glycosylation.
Perturbations in the fibrinolytic pathway abolish cyst formation but not capillary-like organization of cultured murine endothelial cells
Authors: Dubois-Stringfellow N , Jonczyk A , Bautch VL 
Published: October 2019

Abstract
Fibrinolytic activity and its relation to morphogenesis was investigated in several transformed murine endothelial cell lines and primary cultures of endothelial cells. Two in vitro systems, fibrin gels and Matrigel (Collaborative Research, Bedford, MA), were used. Fibrin gels model a fibrin-rich extracellular matrix that frequently supports neovascularization in vivo, and Matrigel models the basement membrane surrounding quiescent endothelial cells in vivo. The transformed endothelial cell lines have higher levels of plasminogen activator (PA) mRNA than primary cultures of endothelial cells, and an increased PA-mediated proteolytic activity was correlated with formation of cysts in fibrin gels. Addition of neutralizing anti- urokinase antibodies, plasminogen depletion, or addition of a plasmin inhibitor prevented cyst formation. Addition of plasminogen restored the ability to form cysts in the plasminogen-depleted system. Normal endothelial cells organized into capillary-like structures in fibrin gels regardless of manipulations affecting the fibrinolytic pathway. In Matrigel, both transformed and primary cultures of endothelial cells rapidly formed a capillary-like network that was not affected by plasminogen depletion or addition of plasmin inhibitors. Thus, elements of the fibrinolytic pathway necessary for cyst formation are not critical in capillary-like structure formation on a reconstituted basement membrane. These results suggest that plasmin is essential for hemangioma formation but is not critical to the organizational behavior of normal endothelial cells.