Red blood cells, phase contrast, interference contrast microscopy and microspectrophotometry.

Following Teorell's (1) observation that the ghosts of hypotonically hemolysed erythrocytes reseal, it was shown that during the time they are permeable to hemoglobin, foreign macromolecules (dextran) can enter and that the hemolysed cell can achieve a final colloid-osmotic equilibrial state containing dextran and some residual Hb. In this way dextran reduces the hemoglobin loss in hypotonic hemolysis. Some hemoglobin loss is, however, inevitable, as it begins with a non-diffusive bulk outflow, sometimes observable as a jet, during which time a diffusive influx of the colloid-osmotic "balancer", dextran, is not possible. Finally, as expected from a process which is for the most part diffusive, transmembrane macromolecular transport is bidirectional; during hemolysis smaller molecules escape to a greater extent than larger ones.

Evaluation by integrated thermography of the beneficial effect of cyclofenil in severe subcutaneous arterial insufficiency.

Integrated thermographic measurements were made in a patient suffering from a complex syndrome which included scleroderma, Osler-Weber-Rendu disease and a marked atherosclerotic circulatory insufficiency. A new anti-estrogenic drug, cyclofenil, elicited a rapid and prolonged curative effect against the entire syndrome. The circulatory amelioration was registered periodically by integrated thermography of the face and both hands. This method enables temperature distribution functions to be calculated and seems to hold considerable promise for the evaluation of circulatory changes and in particular those changes evoked by therapeutic agents.

Jet expulsion of cellular contents from rad cells during photodynamic hemolysis.

When red cells are incubated in the dark in the presence of the dye Rose Bengal and subsequently irradiated with visible light, they hemolyze. Under certain conditions some of the hemoglobin is expelled in the form of a convective jet and appears as a transient cloud beside the cell. Elastic contraction of the membrane is not a sufficient driving force for the jet. A plausible mechanism (an osmotic "pump") is presented.

On how macromolecules reduce hemoglobin loss in hypotonic hemolysis.

When human red cells are hemolysed in hypotonic solutions containing macromolecules, the hemoglobin loss from the individual cells is reduced although the number of cells hemolysed is not affected. The evidence strongly suggests this is a colloid osmotic effect but an additional condition is also necessary if hemoglobin is to be retained. The cell must reseal, at least to hemoglobin and macromolecules. There is some evidence which points to the role of the macromolecule in this process. Further, at least in the case of dextrans, a minimal size of about 2000 daltons is required for suppression of hemoglobin liberation and it is suggested that this limit may be set by the diffusion coefficient.

Passive cutaneous anaphylaxis in guinea pigs elicited by gastric absorption of dextran induced by acetylsalicylic acid.

Passive cutaneous anaphylaxis (PCA) was elicited in guinea pigs sensitized with rabbit antidextran by the absorption of dextran macromolecules from the stomach induced by intragastric acetylsalicylic acid. The gastric contents had a pH sufficiently low to maintain the acid mainly in the unionized form since it is the latter which alters gastric permeability. The acid concentration required to induce PCA was below that which caused mucosal cell loss or bleeding. The maximal molecular weight of the absorbed dextran was approximately 25,000. Dextran was chosen as antigen because of its well-characterized physical and immunological properties. It is suggested that ingestion of acetylsalicylic acid may contribute to sensitization and allergic reactions to antigenic food materials by facilitating their absorption from the stomach.