Blood
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Comparative Study
Sickle cell anemia day hospital: an approach for the management of uncomplicated painful crises.
Painful crisis episodes are poorly treated in sickle cell anemia, both in timeliness and appropriateness of care. Delayed treatment in Emergency Departments, unrelieved pain, frequent admissions, and prolonged hospitalizations are common. We established a Day Hospital (DH) to determine if an alternative care delivery system could improve pain relief and reduce unnecessary hospital admissions for patients with uncomplicated painful crises. ⋯ The length of stay (LOS) for inpatients followed by the DH staff decreased by 1.5 days, while the LOS for patients followed by non-DH staff remained unchanged. Reduction of admissions and LOS represented a savings of approximately $1.7 million. We conclude that a dedicated facility provides the kingpin for effective and rapid painful crisis management, reduces hospitalizations, and facilitates integration of the approach into other areas of care. (Blood. 2000;95:1130-1136)
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Randomized Controlled Trial Clinical Trial
Tissue factor pathway inhibitor dose-dependently inhibits coagulation activation without influencing the fibrinolytic and cytokine response during human endotoxemia.
Inhibition of the tissue factor pathway has been shown to attenuate the activation of coagulation and to prevent death in a gram-negative bacteremia primate model of sepsis. It has been suggested that tissue factor influences inflammatory cascades other than the coagulation system. The authors sought to determine the effects of 2 different doses of recombinant tissue factor pathway inhibitor (TFPI) on endotoxin-induced coagulant, fibrinolytic, and cytokine responses in healthy humans. ⋯ TFPI infusion induced a dose-dependent attenuation of thrombin generation, as measured by plasma F1 + 2 and thrombin-antithrombin complexes, with a complete blockade of coagulation activation after high-dose TFPI. Endotoxin-induced changes in the fibrinolytic system and cytokine levels were not altered by either low-dose or high-dose TFPI. The authors concluded that TFPI effectively and dose-dependently attenuates the endotoxin-induced coagulation activation in humans without influencing the fibrinolytic and cytokine response. (Blood. 2000;95:1124-1129)
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Congenital afibrinogenemia is a rare autosomal recessive disorder characterized by bleeding that varies from mild to severe and by complete absence or extremely low levels of plasma and platelet fibrinogen. Although several mutations in the fibrinogen genes associated with dysfibrinogenemia and hypofibrinogenemia have been described, the genetic defects of congenital afibrinogenemia are largely unknown, except for a recently reported 11-kb deletion of the fibrinogen Aalpha-chain gene. Nevertheless, mutation mechanisms other than the deletion of a fibrinogen gene are likely to exist because patients with afibrinogenemia showing no gross alteration within the fibrinogen cluster have been reported. ⋯ Sequencing of the fibrinogen genes in the 2 probands detected 2 different homozygous missense mutations in exons 7 and 8 of the Bbeta-chain gene, leading to amino acid substitutions Leu353Arg and Gly400Asp, respectively. Transient transfection experiments with plasmids expressing wild-type and mutant fibrinogens demonstrated that the presence of either mutation was sufficient to abolish fibrinogen secretion. These findings demonstrated that missense mutations in the Bbeta fibrinogen gene could cause congenital afibrinogenemia by impairing fibrinogen secretion. (Blood. 2000;95:1336-1341)
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Phospholipid asymmetry is well maintained in erythrocyte (RBC) membranes with phosphatidylserine (PS) exclusively present in the inner leaflet. The appearance of PS on the surface of the cell can have major physiologic consequences, including increased cell-cell interactions. Because increased adherence of PS-exposing RBCs to endothelial cells (ECs) may be pathologically important in hemoglobinopathies such as sickle cell disease and thalassemia, we studied the role of PS exposure in calcium ionophore-treated normal RBC adherence to human umbilical vein endothelial cell (HUVEC) monolayers. ⋯ Similarly, PS-containing lipid vesicles decreased RBC binding by competing for the PS binding sites in the monolayer. PS-exposing RBCs and PS-containing lipid vesicles adhered to immobilized thrombospondin (TSP) and matrix TSP, respectively, and adherence of PS-exposing RBCs to EC monolayers was reduced by antibodies to TSP and to its EC receptor, alpha(v)beta(3). Together, these results indicate a role for PS and matrix TSP in the adherence of PS-exposing RBCs to EC monolayers, and suggest an important contribution of PS-exposing RBCs in pathologies with reported vascular damage, such as sickle cell anemia. (Blood. 2000;95:1293-1300)
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A semiquantitative polymerase chain reaction assay was used to monitor the blood levels of Epstein-Barr virus (EBV)-DNA in 9 patients receiving allogeneic bone marrow transplants (BMT). Four of 5 recipients of HLA-mismatched T-cell-depleted grafts showed a 4- to 5-log increase of EBV-DNA within 1 to 3 months after BMT. Administration of 2 to 4 infusions of 10(7) EBV-specific cytotoxic T-lymphocytes (CTLs)/m(2) starting from the time of maximal virus load resulted in a 2- to 3-log decrease of virus titers in 3 patients. ⋯ A moderate increase of virus titers was also detected in 3 of 4 patients receiving unmanipulated HLA-matched grafts, whereas 1 patient with Wiskott-Aldrich syndrome reached a 5-log increase of EBV-DNA load within 70 days after BMT. Our results suggest that a rapid increase of circulating EBV-DNA occurs in the absence of EBV-specific T-cell precursors or in the presence of congenital immune defects that prevent the reestablishment of virus-specific immunity. Prophylactic administration of EBV-CTLs early after BMT appears to provide the most effective protection against the development of EBV-associated lymphoproliferative disease.