Viscoelastic properties of blood studied through piezoresistance measurements.

Piezoresistance describes the change of electrical resistance in a material undergoing deformation. Heterogeneous materials having different resistivities of dispersed and continuous matrix phases, such as blood (comprised of red and white blood cells and platelets suspended in plasma), can exhibit the piezoresistance effect. For an initially isotropic material, two independent intrinsic material coefficients, λ1 and λ2, would uniquely describe the piezoresistance phenomenon.

Dose of prophylactic platelet transfusions and prevention of hemorrhage.

Background: We conducted a trial of prophylactic platelet transfusions to evaluate the effect of platelet dose on bleeding in patients with hypoproliferative thrombocytopenia.

Methods: We randomly assigned hospitalized patients undergoing hematopoietic stem-cell transplantation or chemotherapy for hematologic cancers or solid tumors to receive prophylactic platelet transfusions at a low dose, a medium dose, or a high dose (1.1x10(11), 2.

Rituximab therapy for thrombotic thrombocytopenic purpura: a proposed study of the Transfusion Medicine/Hemostasis Clinical Trials Network with a systematic review of rituximab therapy for immune-mediated disorders.

The rationale for immunosuppressive therapy of thrombotic thrombocytopenic purpura (TTP) was established by observations that TTP may be caused by autoantibodies to ADAMTS13. Patients with high-titer autoantibodies to ADAMTS13 may have a higher mortality, and survivors may require prolonged plasma exchange therapy in spite of adjunctive glucocorticoid treatment. More intensive immunosuppressive therapy with rituximab may provide benefit for many of these patients.

Hemoglobinopathy case finding by pulse oximetry.

Pulse oximetry is a widely used, noninvasive instrument for monitoring oxygen saturation. Its use, however, is limited in the setting of dyshemoglobinemias. We report a case of hemoglobin Rothschild in an Asian patient diagnosed as a result of routine pulse oximetry.

Low-O(2) affinity erythrocytes improve performance of ischemic myocardium.

O(2) transport and O(2) diffusion interact in providing O(2) to tissue, but the extent to which diffusion may be critical in the heart is unclear. If O(2) diffusion limits mitochondrial oxygenation, a change in blood O(2) affinity at constant total O(2) transport should alter cardiac O(2) consumption (VO(2)) and function. To test this hypothesis, we perfused isolated isovolumically working rabbit hearts with erythrocytes at physiological blood-gas values and P(50) (PO(2) required to half-saturate hemoglobin) values at pH of 7.