bluuebunny/crossref_metadata_2025_split huggingface dataset:
The incidence of heparin-induced thrombocytopenia in hospitalized medical patients treated with subcutaneous unfractionated heparin: a prospective cohort study
Authors: Girolami Bruno , Prandoni Paolo , Stefani Piero M. , Tanduo Cinzia , Sabbion Paola , Eichler Petra , Ramon Roberto , Baggio Giovannella , Fabris Fabrizio , Girolami Antonio 
Published: April 2003

Abstract
Although heparin-induced thrombocytopenia (HIT) is a known complication of intravenous unfractionated heparin (UFH), its incidence in medical patients treated with subcutaneous UFH is less well defined. To determine the incidence of HIT in this category of patients, the platelet count was performed at baseline and then every 3 ± 1 days in 598 consecutive patients admitted to 2 medical wards and treated with subcutaneous UFH for prophylactic (n = 360) or therapeutic (n = 238) indications. The diagnosis of HIT was accepted in the case of a platelet drop of 50% or more and either the demonstration of heparin-dependent antibodies or (when this search could not be performed) the combination of the following features: (1) the absence of any other obvious clinical explanation for thrombocytopenia, (2) the occurrence of thrombocytopenia at least 5 days after heparin start, and (3) either the normalization of the platelet count within 10 days after heparin discontinuation or the earlier patient's death due to an unexpected thromboembolic complication. HIT developed in 5 patients (0.8%; 95% CI, 0.1%-1.6%); all of them belonged to the subgroup of patients who received heparin for prophylactic indications. The prevalence of thromboembolic complications in patients with HIT (60%) was remarkably higher than that observed in the remaining 593 patients (3.5%), leading to an odds ratio of 40.8 (95% CI, 5.2-162.8). Although the frequency of HIT in hospitalized medical patients treated with subcutaneous heparin is lower than that observed in other clinical settings, this complication is associated with a similarly high rate of thromboembolic events.
Discrimination of polycythemias and thrombocytoses by novel, simple, accurate clonality assays and comparison with PRV-1 expression and BFU-E response to erythropoietin
Authors: Liu Enli , Jelinek Jaroslav , Pastore Yves D. , Guan Yongli , Prchal Jaroslav F. , Prchal Josef T. 
Published: April 2003

AbstractEssential thrombocythemia (ET) and polycythemia vera (PV) are clonal myeloproliferative disorders that are often difficult to distinguish from other causes of elevated blood cell counts. Assays that could reliably detect clonal hematopoiesis would therefore be extremely valuable for diagnosis. We previously reported 3 X-chromosome transcription-based clonality assays (TCAs) involving the G6PD, IDS, and MPP1 genes, which together were informative in about 65% of female subjects. To increase our ability to detect clonality, we developed simple TCA for detecting the transcripts of 2 additional X-chromosome genes: Bruton tyrosine kinase (BTK) and 4-and-a-half LIM domain 1 (FHL1). The combination of TCA established the presence or absence of clonal hematopoiesis in about 90% of female subjects. We show that both genes are subject to X-chromosome inactivation and are polymorphic in all major US ethnic groups. The 5 TCAs were used to examine clonality in 46 female patients along with assays for erythropoietin-independent erythroid colonies (EECs) and granulocyte PRV-1 mRNA levels to discriminate polycythemias and thrombocytoses. Of these, all 19 patients with familial polycythemia or thrombocytosis had polyclonal hematopoiesis, whereas 22 of 26 patients with clinical evidence of myeloproliferative disorder and 1 patient with clinically obscure polycythemia were clonal. Interestingly, interferon α therapy in 2 patients with PV was associated with reversion of clonal to polyclonal hematopoiesis. EECs were observed in 14 of 14 patients with PV and 4 of 12 with ET, and increased granulocyte PRV-1 mRNA levels were found in 9 of 13 patients with PV and 2 of 12 with ET. Thus, these novel clonality assays are useful in the diagnosis and follow-up of polycythemic conditions and disorders with increased platelet levels.
The tetrapeptide AcSDKP, an inhibitor of primitive hematopoietic cell proliferation, induces angiogenesis in vitro and in vivo
Authors: Liu Jian-Miao , Lawrence Françoise , Kovacevic Milica , Bignon Jérôme , Papadimitriou Evangelia , Lallemand Jean-Yves , Katsoris Panagiotis , Potier Pierre , Fromes Yves , Wdzieczak-Bakala Joanna 
Published: April 2003

AbstractThe tetrapeptide acetyl-Ser-Asp-Lys-Pro (AcSDKP), purified from bone marrow and constitutively synthesized in vivo, belongs to the family of negative regulators of hematopoiesis. It protects the stem cell compartment from the toxicity of anticancer drugs and irradiation and consequently contributes to a reduction in marrow failure. This current work provides experimental evidence for another novel biologic function of AcSDKP. We report that AcSDKP is a mediator of angiogenesis, as measured by its ability to modulate endothelial cell function in vitro and angiogenesis in vivo. AcSDKP at nanomolar concentrations stimulates in vitro endothelial cell migration and differentiation into capillary-like structures on Matrigel as well as enhances the secretion of an active form of matrix metalloproteinase-1 (MMP-1). In vivo, AcSDKP promotes a significant angiogenic response in the chicken embryo chorioallantoic membrane (CAM) and in the abdominal muscle of the rat. Moreover, it induces the formation of blood vessels in Matrigel plugs implanted subcutaneously in the rat. This is the first report demonstrating the ability of AcSDKP to interact directly with endothelial cells and to elicit an angiogenic response in vitro and in vivo.
Recombinant P-selectin glycoprotein ligand–1 directly inhibits leukocyte rolling by all 3 selectins in vivo: complete inhibition of rolling is not required for anti-inflammatory effect
Authors: Hicks Anne E. R. , Nolan Sarah L. , Ridger Victoria C. , Hellewell Paul G. , Norman Keith E. 
Published: April 2003

AbstractSelectin-dependent leukocyte rolling is one of the earliest steps of an acute inflammatory response and, as such, contributes to many inflammatory diseases. Although inhibiting leukocyte rolling with selectin antagonists is a strategy that promises far-reaching clinical benefit, the perceived value of this strategy has been limited by studies using inactive, weak, or poorly characterized antagonists. Recombinant P-selectin glycoprotein ligand–1–immunoglobulin (rPSGL-Ig) is a recombinant form of the best-characterized selectin ligand (PSGL-1) fused to IgG, and is one of the best prospects in the search for effective selectin antagonists. We have used intravital microscopy to investigate the ability of rPSGL-Ig to influence leukocyte rolling in living blood vessels and find that it can reduce rolling dependent on each of the selectins in vivo. Interestingly, doses of rPSGL-Ig required to reverse pre-existing leukocyte rolling are 30-fold higher than those required to limit inflammation, suggesting additional properties of this molecule. In support of this, we find that rPSGL-Ig can bind the murine chemokine KC and inhibit neutrophil migration toward this chemoattractant in vitro.
Antithrombin reduces ischemia/reperfusion-induced renal injury in rats by inhibiting leukocyte activation through promotion of prostacyclin production
Authors: Mizutani Akio , Okajima Kenji , Uchiba Mitsuhiro , Isobe Hirotaka , Harada Naoaki , Mizutani Sachiko , Noguchi Takayuki 
Published: April 2003

AbstractAntithrombin (AT) supplementation in patients with severe sepsis has been shown to improve organ failures in which activated leukocytes are critically involved. However, the precise mechanism(s) for the therapeutic effects of AT is not well understood. We examined in rats whether AT reduces ischemia/reperfusion (I/R)–induced renal injury by inhibiting leukocyte activation. AT markedly reduced the I/R-induced renal dysfunction and histologic changes, whereas neither dansyl glutamylglycylarginyl chloromethyl ketone–treated factor Xa (DEGR-F.Xa), a selective inhibitor of thrombin generation, nor Trp49-modified AT, which lacks affinity for heparin, had any effect. Renal tissue levels of 6-keto-PGF1α, a stable metabolite of prostacyclin (PGI2), increased after renal I/R. AT enhanced the I/R-induced increases in renal tissue levels of 6-keto-PGF1α, whereas neither DEGR-F.Xa nor Trp49-modified AT had any effect. AT significantly inhibited I/R-induced decrease in renal tissue blood flow and the increase in the vascular permeability. Ischemia/reperfusion-induced increases in renal tissue levels of tumor necrosis factor-α, cytokine-induced neutrophil chemoattractant, and myeloperoxidase were significantly inhibited in animals given AT. Pretreatment of animals with indomethacin reversed the effects induced by AT. Iloprost, an analog of PGI2, produced effects similar to those induced by AT. These observations strongly suggest that AT reduces the I/R-induced renal injury by inhibiting leukocyte activation. The therapeutic effects of AT might be mainly mediated by PGI2released from endothelial cells through interaction of AT with cell surface glycosaminoglycans.
Monoclonal T-cell expansions in asymptomatic individuals and in patients with large granular leukemia consist of cytotoxic effector T cells expressing the activating CD94:NKG2C/E and NKD2D killer cell receptors
Authors: Bigouret Valérie , Hoffmann Till , Arlettaz Lionel , Villard Jean , Colonna Marco , Ticheli André , Gratwohl Alois , Samii Kaveh , Chapuis Bernard , Rufer Nathalie , Roosnek Eddy 
Published: April 2003

AbstractWe have analyzed the phenotype, cytokine profile, and mitotic history (telomere length) of monoclonal T-cell expansions in 5 CD3+ T-cell large granular lymphocyte (TLGL) leukemia patients by fluorescence activated cell sorting (FACS) and single-cell polymerase chain reaction (PCR). We confirm that the common phenotype of TLGL leukemia is CD3+CD8+CD45RA+CD27−CD94+(CD57+). Interestingly, the C-type lectin-like type killer cell receptor CD94 was invariably associated with the activating form of its signal-transducing molecule NKG2. Furthermore, when judged by criteria such as interferon gamma (IFN-γ)/tumor necrosis factor (TNF) production, expression of granzyme, FasL, and NKG2D, the TLGL cells had all the features of a cytotoxic effector T cell. Telomere shortening in TLGL cells was in the normal range for CD8+ T cells, indicating that they had not divided significantly more than chronically stimulated CD8+ T cells in healthy individuals. In 25 of 27 controls, cells with a TLGL phenotype occurred at low (1%-3%) frequencies. However, in the other 2 individuals (ages 28-36 years), large stable (> 3 years) monoclonal expansions of CD3+CD8+CD45RA+CD27−CD57+CD94+ NKG2C+ were found which rendered these controls phenotypically indistinguishable from TLGL leukemia patients. We believe that the TLGL clonopathy, rather than being of a neoplastic nature, is more likely an extreme manifestation of the large and stable clonal size characteristic of CD8+ effector cells. Such a TLGL clone consisting of cells without any particular pathologic trait might exist in a considerable number of individuals. Clinical symptoms may occur in individuals in whom the TLGL clone encounters antigen and is triggered to produce large amounts of effector molecules that dysregulate the immune system, which could manifest itself as autoimmunity or as a FasL-mediated neutropenia.
Features of the overexpressed V1-69 genes in the unmutated subset of chronic lymphocytic leukemia are distinct from those in the healthy elderly repertoire
Authors: Potter Kathleen N. , Orchard Jenny , Critchley Eustacia , Mockridge C. Ian , Jose Annette , Stevenson Freda K. 
Published: April 2003

AbstractChronic lymphocytic leukemia (CLL) comprises 2 subsets, distinguished by expression of unmutated or mutated VHgenes, with the former having a worse prognosis. Biased usage of the V1-69 gene is found in unmutated cases and is combined with selected D gene segments and JH6. It is controversial whether this is a CLL-associated feature or mirrors the normal B-cell pattern. Since CLL is a disease of the elderly, where changes in the B-cell repertoire may occur, we have analyzedV1-69 usage in the elderly (older than 75 years) population. Using monoclonal antibody (MoAb) G6, specific for 51p1-related V1-69 alleles, we found no increased expression with age. In 51p1-encoded immunoglobulin M (IgM), complementarity-determining region 3 (CDR3) length and frequency of D and JH genes were similar to those in the healthy young and distinct from those in CLL. These findings support the concept that CLL arises from B cells driven by antigen/superantigen and is not a stochastic event in the elderly B-cell population.
Cell death induced by granzyme C
Authors: Johnson Hillary , Scorrano Luca , Korsmeyer Stanley J. , Ley Timothy J. 
Published: April 2003

AbstractAlthough the functions of granzymes A and B have been defined, the functions of the other highly expressed granzymes (Gzms) of murine cytotoxic lymphocytes (C, D, and F) have not yet been evaluated. In this report, we describe the ability of murine GzmC (which is most closely related to human granzyme H) to cause cell death. The induction of death requires its protease activity and is characterized by the rapid externalization of phosphatidylserine, nuclear condensation and collapse, and single-stranded DNA nicking. The kinetics of these events are similar to those caused by granzyme B, and its potency (defined on a molar basis) is also equivalent. The induction of death did not involve the activation of caspases, the cleavage of BID, or the activation of the CAD nuclease. However, granzyme C did cause rapid mitochondrial swelling and depolarization in intact cells or in isolated mitochondria, and this mitochondrial damage was not prevented by cyclosporin A pretreatment. These results suggest that granzyme C rapidly induces target cell death by attacking nuclear and mitochondrial targets and that these targets are distinct from those used by granzyme B to cause classical apoptosis.
Elevated prothrombin results in clots with an altered fiber structure: a possible mechanism of the increased thrombotic risk
Authors: Wolberg Alisa S. , Monroe Dougald M. , Roberts Harold R. , Hoffman Maureane 
Published: April 2003

AbstractIndividuals with elevated prothrombin levels are at increased risk of venous thrombosis. To understand the mechanism behind this observation, we studied the effect of prothrombin concentration on thrombin generation and fibrin clot structure. The pattern of thrombin generation was directly related to the prothrombin level at all concentrations tested. From 0% to 300% of normal plasma levels of prothrombin, increasing the prothrombin concentration increased the initial rate, peak, and total amount of thrombin generated. Importantly, fibrin clot structure was also affected by the prothrombin concentration. Fibrin clots made from prothrombin concentrations less than 10% of plasma levels were weak and poorly formed. Fibrin clots made at 10% to 100% of plasma levels of prothrombin had similar fiber structures (mass-to-length ratio; μ). However, the fiber mass-to-length ratio decreased with increasing prothrombin levels more than 100% of plasma levels, in a dose-dependent manner. These results suggest that increased levels of prothrombin alter thrombin generation and clot structure. Specifically, elevated prothrombin levels produce clots with reduced fibrin mass-to-length ratios compared with normal clots. We hypothesize that this alteration in fibrin clot structure is an important determinant of the risk of thrombosis.
Distinct dose-dependent effects of plasmin and TPA on coagulation and hemorrhage
Authors: Stewart Daphne , Kong Mansze , Novokhatny Valery , Jesmok Gary , Marder Victor J. 
Published: April 2003

AbstractAll thrombolytic agents in current clinical usage are plasminogen activators. Although effective, plasminogen activators uniformly increase the risk of bleeding complications, especially intracranial hemorrhage, and no laboratory test is applicable to avoid such bleeding. We report results of a randomized, blinded, dose-ranging comparison of tissue-type plasminogen activator (TPA) with a direct-acting thrombolytic agent, plasmin, in an animal model of fibrinolytic hemorrhage. This study focuses on the role of plasma coagulation factors in hemostatic competence. Plasmin at 4-fold, 6-fold, and 8-fold the thrombolytic dose (1 mg/kg) induced a dose-dependent effect on coagulation, depleting antiplasmin activity completely, then degrading fibrinogen and factor VIII. However, even with complete consumption of antiplasmin and decreases in fibrinogen and factor VIII to 20% of initial activity, excessive bleeding did not occur. Bleeding occurred only at 8-fold the thrombolytic dose, on complete depletion of fibrinogen and factor VIII, manifest as prolonged primary bleeding, but with minimal effect on stable hemostatic sites. Although TPA had minimal effect on coagulation, hemostasis was disrupted in a dose-dependent manner, even at 25% of the thrombolytic dose (1 mg/kg), manifest as rebleeding from hemostatically stable ear puncture sites. Plasmin degrades plasma fibrinogen and factor VIII in a dose-dependent manner, but it does not disrupt hemostasis until clotting factors are completely depleted, at an 8-fold higher dose than is needed for thrombolysis. Plasmin has a 6-fold margin of safety, in contrast with TPA, which causes hemorrhage at thrombolytic dosages.
Downstream effectors of oncogenic ras in multiple myeloma cells
Authors: Hu Liping , Shi Yijiang , Hsu Jung-hsin , Gera Joseph , Van Ness Brian , Lichtenstein Alan 
Published: April 2003

AbstractEctopic expression of mutated K-ras or N-ras in the interleukin 6 (IL-6)–dependent ANBL6 multiple myeloma cell line induces cytokine-independent growth. To investigate the signaling pathways activated by oncogenic ras that may stimulate IL-6–independent growth, we compared ANBL6 cells stably transfected with mutated K or N-ras genes with wild-type ras–expressing control cells identically transfected with an empty vector. Upon depletion of IL-6, both mutated ras–containing myeloma lines demonstrated constitutive activation of mitogen-activated extracellular kinase 2(MEK)/extracellular signal–regulated kinase (ERK), phosphatidylinositol-3 kinase (PI3-kinase)/AKT, mammalian target of rapamycin (mTOR)/p70S6-kinase, and nuclear factor kappaB (NF-kB) pathways. In contrast, signal transducer and activator of transcription–3 (STAT-3) was not constitutively tyrosine phosphorylated in mutant ras–expressing cells. We used several maneuvers in attempts to selectively target these constitutively active pathways. The mTOR inhibitors rapamycin and CCI-779, the PI3-kinase inhibitor LY294002, and the MEK inhibitor PD98059 all significantly curtailed growth of mutant ras–containing cells. Farnesyl transferase inhibitors, used to target ras itself, had modest effects only against mutant N-ras–containing cells. Growth of mutant N-ras–containing myeloma cells was also inhibited by acute expression of the IKBsuperrepressor gene, which abrogated NF-kB activation. These results indicate that several pathways contributing to stimulation of cytokine-independent growth are activated downstream of oncogenic ras in myeloma cells. They also suggest that therapeutic strategies that target these pathways may be particularly efficacious in patients whose myeloma clones contain ras mutations.
Cotreatment with the histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA) enhances imatinib-induced apoptosis of Bcr-Abl–positive human acute leukemia cells
Authors: Nimmanapalli Ramadevi , Fuino Lianne , Stobaugh Corinne , Richon Victoria , Bhalla Kapil 
Published: April 2003

Abstract
Here we demonstrate that treatment with SAHA (suberoylanilide hydroxamic acid), a known inhibitor of histone deacetylases (HDACs), alone induced p21 and/or p27 expressions but decreased the mRNA and protein levels of Bcr-Abl, which was associated with apoptosis of Bcr-Abl–expressing K562 and LAMA-84 cells. Cotreatment with SAHA and imatinib (Gleevec) caused more down-regulation of the levels and auto-tyrosine phosphorylation of Bcr-Abl and apoptosis of these cell types, as compared with treatment with either agent alone (P < .05). This finding was also associated with a greater decline in the levels of phospho-AKT and Bcl-xL. Significantly, treatment with SAHA also down-regulated Bcr-Abl levels and induced apoptosis of CD34+ leukemia blast progenitor cells derived from patients who had developed progressive blast crisis (BC) of chronic myelocytic leukemia (CML) while receiving therapy with imatinib. Taken together, these findings indicate that cotreatment with SAHA enhances the cytotoxic effects of imatinib and may have activity against imatinib-refractory CML-BC.
Cobalamin deficiency with and without neurologic abnormalities: differences in homocysteine and methionine metabolism
Authors: Carmel Ralph , Melnyk Stepan , James S. Jill 
Published: April 2003

AbstractThe unknown biochemical basis for neurologic dysfunction in cobalamin deficiency and the frequent divergence between neurologic and hematologic manifestations led us to study homocysteine metabolism in 22 patients with pernicious anemia. Serum levels of total homocysteine (tHcy), methionine, S-adenosylmethionine (AdoMet), cysteine, cysteinylglycine (cys-gly), and glutathione (GSH) were measured. Only levels of tHcy and cysteine were increased and only GSH was decreased in cobalamin deficiency as a whole, compared with 17 control subjects. AdoMet correlated only with methionine levels (P = .015) and cysteine only with cys-gly (P = .007) in healthy subjects, but in cobalamin-deficient patients AdoMet correlated instead with cysteine, cys-gly, and folate levels only (P = .008,P = .03, and P = .03, respectively). Significant differences appeared in clinically subgrouped cobalamin-deficient patients. The 11 patients with neurologic defects had higher mean levels of folate (27.9 versus 15.4 nM), AdoMet (117.2 versus 78.6 nM), cysteine (462 versus 325 μM), and cys-gly (85.0 versus 54.7 μM) than the 11 neurologically unaffected patients. Cobalamin therapy restored all metabolic changes to normal. The results indicate that changes in several metabolic pathways differ in patients with and without neurologic dysfunction. Cysteine levels were the most significant predictors of neurologic dysfunction, but it is unclear if they are direct or indirect indicators of neurotoxicity. The higher AdoMet levels in neurologically affected patients may result from inhibition of glycine N-methyltransferase by those patients' higher folate levels. The origin of the folate differences is unclear and possibly varied. Low AdoMet and GSH levels were independent predictors of anemia.