Catecholamine release from chromaffin granules, suspended in sucrose solutions of various osmotic strengths, was determined at different temperatures between 2 degrees and 44 degrees C. Dynamic measurements showed that steady state is achieved within 15 min of incubation at all temperatures. The effect of temperature on the release was established in terms of the median granular fragility (MGF)...

Erythrocytes from patients with hereditary spherocytosis (HS) undergo changes in cation and lipid content when incubated in vitro under sterile conditions for 24 hours. These are accompanied by changes in cell volume, osmotic fragility, and the critical volume at which hemoly-sis of the cell occurs. Normal red cells have been found to undergo similar changes but with a longer time scale, the no...

OBJECTIVE To determine the effect of 3 differing transfusion techniques on survival of autologous canine RBCs. DESIGN Prospective, blinded study. SETTING University Teaching Hospital. ANIMALS Nine healthy dogs. INTERVENTIONS Three distinct preparations of RBCs, each representing ~1% of red cell mass, were generated for each dog by biotinylation of RBCs at varying biotin densities. Label...

Strategies to prevent diabetic microvascular angiopathy focus on the vascular endothelium. Because red blood cells (RBCs) are less deformable in diabetes, we explored an original concept linking decreased RBC deformability to RBC ascorbate and hyperglycemia. We characterized ascorbate concentrations from human and mouse RBCs and plasma, and showed an inverse relationship between RBC ascorbate c...

A child diagnosed in utero with hydrops fetalis and a hematocrit of 6.4% was studied to determine the etiology of the anemia. Fetal red blood cells (RBCs) obtained during in utero transfusion had extremely abnormal osmotic fragility. A maternal history of mild autosomal dominant hereditary spherocytosis was present, and the father, who was hematologically normal, had a slightly abnormal osmotic...

Propolis is a resinous substance collected from plants by bees. Its composition depends on the vegetation, the season, and the source area. It usually contains many chemical compounds such as polyphenols, steroids and amino acids. The hereditary spherocytosis (HS) is a type of anaemia characterized by microcytic and hyperchromic red cells, spherical in shape and without central pallor. Clinical...