Red Cell Deformability
Mostrando 1-12 de 25 artigos, teses e dissertações.
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1. Aplicação da pinça optica para o estudo da deformabilidade das hemacias
The deformability of erythrocytes is a critical determinant of blood flow in microcirculation. By capturing red blood cells with optical tweezers and dragging them through a viscous fluid we were able to measure their overall elasticity. Laser optical tweezers, based on photon momentum transfer, have been used successfully in a variety of biological applicat
Publicado em: 2003
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2. Evaluation of the red cell deformability through ektacytometry in iron deficiency / Avaliação da deformidade eritrocitária através da ectacitometria na deficiência de ferro
The deformability allows the 7 to 8 cm red cell to circulate through capillaries of 3 cm. This phenomenon depends on cellular geometry, internal viscosity and viscoelastic properties of the membrane. Among the various techniques of erytrocyte deformability (ED) analysis such as: micropipette aspiration, filtration and reoscopy, we chose ektacytometry. This t
Publicado em: 2002
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3. Liberação de radicais livres por leucocitos de pacientes com anemia falciforme
Sickle cell anemia is a genetic disorder of red blood cells characterized by chronic hemolysis and episodic vaso-oclusive crisis. The molecular defect is caused by a point mutation at the 6thposition ofthe f3chain ofhemoblobin, which leads erythrocytes to abnormal sickle shape, rigidity, deformability and distortion with consequent blood flow obstruction. A
Publicado em: 2002
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4. Effect of reconstructive vascular surgery on red cell deformability--preliminary results.
Using a simple filtration method, red cell deformability was measured in healthy control subjects and in patients with peripheral vascular disease. Impaired red cell deformability was demonstrated in patients with rest pain or gangrene and in patients with intermittent claudication. An improvement in red cell deformability was demonstrated after successful r
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5. Red cell deformability is not an independent risk factor in stroke.
Reduced erythrocyte deformability has been implicated in the causation of stroke. We have therefore tested this red cell property by filtration through polycarbonate membranes in 42 patients with either transient ischaemic attacks or completed ischaemic stroke together with age and sex paired controls. We have failed to demonstrate any difference between pat
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6. Effect of catecholamines on deformability of red cells from trout: relative roles of cyclic AMP and cell volume.
1. In the presence of catecholamine the nucleated red blood cells of trout show a large increase in cell volume as a result of an accumulation of sodium and chloride due to activation of an amiloride-sensitive, cyclic AMP-dependent Na+-H+ exchanger allowing Na+ to enter in exchange for internal H+. 2. The activation of this cyclic AMP-dependent Na+-H+ exchan
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7. Metabolic dependence of red cell deformability
The contribution of the metabolic state of human erythrocytes to maintenance of cellular deformability was studied during and after in vitro incubation in serum for periods up to 28 hr. An initial loss of membrane deformability became apparent between 4 and 6 hr when cellular adenosine triphosphate (ATP) levels were approximately 70% of initial values. Membr
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8. Changes in red cell deformability and other haemorrheological variables after myocardial infarction.
Haemorrheological variables were studied in 43 patients after acute myocardial infarction. Red cell deformability, by a filtration method, was significantly lower within 12 hours of infarction than subsequently. This drop was greater in the presence of haemodynamic complications. Blood viscosity, particularly when adjusted to a standard haematocrit, rose in
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9. Does blood rheology revert to normal after myocardial infarction?
After myocardial infarction there is an acute deterioration of the flow properties of blood. The present study was designed to test whether the abnormality persists. Blood and plasma viscosity, red cell aggregation and deformability, haematocrit, erythrocyte sedimentation rate, white cell count, cholesterol, and triglycerides were measured in 51 patients who
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10. Alteration in the rheologic properties of plasmodium knowlesi-infected red cells. A possible mechanism for capillary obstruction
Red cells parasitized by Plasmodium knowlesi concentrate within the microcirculation of many organs including cerebral capillaries in rhesus monkeys. The possibility that P. knowlesi could alter the rheologic properties of red cells so that they are trapped within capillaries was investigated in the present study. The viscosity of P. knowlesi-infected red ce
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11. Preferential Binding of βS Globin Chains Associated with Stroma in Sickle Cell Disorders
Sickle cell anemia (SS) is associated with abnormalities of the red cell membrane and decreased red cell deformability. The present study assesses globin chain binding to stroma in SS, sickle cell trait (AS), and nonsickling (AA) cells. The results indicate that there is preferential binding of newly synthesized βS globin to red cell stroma in SS cells and
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12. Studies on erythrocyte membranes of patients with Huntington's disease
Several red cell membrane properties and activities of membrane-bound enzymes were investigated in blood samples of patients with Huntington's disease. (Na++K+) ATPase activity and cell deformability appeared to be normal, in contradiction to preceding reports from other laboratories. With other techniques sensitive to relatively small changes in membrane st