Abnormal deposits of free iron are found on the cytoplasmic surface of red blood cell (RBC) membranes in beta-thalassemia. To test the hypothesis that this is of importance to RBC pathobiology, we administered the iron chelator deferiprone (L1) intraperitoneally to beta-thalassemic mice for 4 wk and then studied RBC survival and membrane characteristics. L1 therapy decreased membrane free iron ...

The effect of spent culture supernatant on RBC membrane mechanical properties, RBC membrane deformability and stability, were assayed by ektacytometry after treating RBC ghost membranes with spent Plasmodium falciparum (P. falciparum) malaria culture supernatant fluid (Pf(+)), malaria culture medium which had not been exposed to P. falciparuminfected RBCs Pf(-), and malaria culture medium from ...

The survival of erythrocytes (RBC) is shortened in uremia, and it has been shown that calcium influx into RBC evoked crenation and increased their rigidity. The high blood levels of parathyroid hormone (PTH) may augment entry of calcium into RBC and hence affect their integrity. We examined the effect of PTH on osmotic fragility of human RBC and investigated the mechanisms through which PTH int...

The different genetic markers of pneumococcal transforming DNA are inactivated in solution at characteristic temperatures, analogous to melting points. These temperatures are spaced sufficiently to permit inactivation of the lower melting markers while the others are preserved intact.' Such partially inactivated DNA has been considered to be a mixture of native and denatured molecules.1 If this...

OBJECTIVE Transfusion of aged blood has been associated with increased morbidity and mortality in critically ill patients. During storage, erythrocytes release increasing numbers of microvesicles (red blood cell-derived microvesicles [RBC-MV]). We hypothesized that RBC-MV mediate some of the deleterious effects of aged blood transfusions. APPROACH AND RESULTS We established a murine transfusi...

NMR studies of protein denatured states provide insights into potential initiation sites for folding that may be too transient to be observed kinetically. We have characterized the structure and dynamics of the acid-denatured state of protein G by using a F30H mutant of G(B1) which is on the margin of stability. At 5 degrees C, F30H-G(B1) is greater than 95% folded at pH 7.0 and is greater than...

The denatured states of proteins have always attracted our attention due to the fact that the denatured state is the only experimentally achievable state of a protein, which can be taken as initial reference state for considering the in vitro folding and defining the native protein stability. It is known that heat and guanidinium chloride (GdmCl) give structurally different states of RNase-A, l...

BACKGROUND Nitric oxide (NO) produced by nitric oxide synthase (NOS) in human red blood cells (RBCs) was shown to depend on shear stress and to exhibit important biological functions, such as inhibition of platelet activation. In the present study we hypothesized that exercise-induced shear stress stimulates RBC-NOS activation pathways, NO signaling, and deformability of human RBCs. METHODS/F...

Red blood cells (RBC) become sensitized following the elution of strain 575 Newcastle disease virus (NDV). The neuraminidase (NA) in the haemagglutinin (HA)-sialic acid configuration is inactive. The HA on sensitized RBC agglutinates normal RBC. The sialic acid on normal RBC initiated reactivation of the NA-a newly described function. Then normal-sensitized RBC agglomerates separated at 37 degr...