Diffractometric measurements of the tonicity volume relations of human red cells in hypotonic systems

Red cell volumes in media sufficiently hypotonic to produce partial hemolysis have been measured with a high speed hematocrit and by an improved diffraction method. A comparison of the results shows that the upward departures from the linear relation based on the van't Hoff-Mariotte law are not observed when the volumes are measured diffractometrically. Downward departures are observed at low tonicities by both methods. These results provide strong evidence that the upward departures are due to the inclusion of semirigid ghosts in the column of packed red cells which is measured when the volumes are found with the hematocrit.

The sorption of influenza virus by chicken erythrocytes

Data are presented which indicate that the forces of attraction between influenza virus and chicken erythrocytes are governed by an orderly mechanism which effects a proportional distribution of virus between erythrocytes and suspending fluid. For a unit mass of erythrocytes, the ratio of combined (sorbed) virus to free (unsorbed) virus is sufficiently constant over a wide range of virus concentrations to indicate compliance with the laws of mass action, or, perhaps, with the laws of simple adsorption; however, the ratio of combined (sorbed) virus to free (unsorbed) virus appears to be a parabolic function of the total quantity of virus.

Permeability properties of erythrocyte ghosts

1. Erythrocyte ghosts from human blood were produced by gentle water hemolysis. The ghost-containing hemolysate (about 20 mN) was added to media of different composition (KCl, NaCl, glucose, sucrose, etc.) and varying concentration ranging from 8 to 840 mN. The volume changes of the ghost cells were followed by a light absorption method. The potassium and sodium concentrations were also analyzed in some representative cases. 2. The ghosts shrank, or swelled, in two stages. An initial phase with a momentary expulsion, or uptake, of water leading to an osmotic equilibrium, was followed by a second phase in which a slow swelling or shrinking proceeded toward a final constant volume. 3. The ghosts were semipermeable in the sense that water always passed rapidly in either direction so as to maintain isotonicity with the external medium. The relation between ghost cell volumes (V) and the total concentration (C_e) of the suspension medium can be expressed by a modified van't Hoff-Mariotte law: (C_e + a)(V – b) = constant. Here a is a term correcting for an internal pressure and b is the non-solvent volume of the ghost cells. This means that the ghosts behave as perfect osmometers. 4. On the other hand appreciable concentration differences of the K and Na ions could be maintained across the intact ghost cell membranes for long periods. Whether this phenomenon is due simply to very low cation permeability or to active transport processes cannot be decided, although the first assumption appears more probable. 5. When the ghosts were treated with small concentrations of a lytic substance like Na oleate, the alkali ion transfer was greatly increased. This seems to be a simple exchange diffusion process with simultaneous, continued maintenance of osmotic equilibrium (= the second phase). A simplified theory is also given for the kinetics of the volume variations and ion exchange during the second phase (cf. the Appendix). 6. Miscellaneous observations on the effects of pH, and of some other substances are discussed. Some shape transformations of the ghost cells are also described.

A microspectrophotometric study of red cell nuclei during pyknosis

1. A microspectrophotometric apparatus was used to measure nuclear absorption in fixed and stained human bone marrow smears. 2. The validity of the measurements was established. 3. The total and polymerized desoxyribose nucleic acid (DNA) of erythroblast nuclei were measured in relative units, and a gradual loss of DNA from the red cell nucleus during maturation was noted. 4. The loss in DNA is comparable quantitatively to that occurring during pathological pyknosis in sarcoma cells. 5. The continual loss of nuclear material during erythropoiesis supports the conception that the nucleus disappears by intracellular dissolution, not by extrusion in the intact form.

Anomalous features of the loss of K from human red cells; results of extended observations

1. The anomalous course of the curves relating K loss to time in systems containing human red cells in isotonic NaCl, and particularly the high positions of the asymptotes to which the curves apparently proceed, are due to the population of red cells consisting of at least two components, one of which loses K more readily than the other. 2. Since large K-Na exchanges can occur between red cells and an isotonic suspension medium without there being large volume changes, a restatement of the "dual mechanism of hemolysis" hypothesis, which takes account of the cell's being slowly permeable to cations, is required. If some approximations of minor consequence are allowed, the hypothesis can be restated in a quantitatively satisfactory way. 3. The general features of K-Na exchanges, including prolytic exchanges are summarized.

Cation exchange in mammalian erythrocytes. III. The prolytic effect of x-rays on human cells

Freshly drawn heparinized human whole blood is exposed to x-rays in amounts up to 54,000 r in vitro and then equilibrated under a controlled atmosphere at 24 or 38°C. For as long as 26 hours following exposure, potassium is progressively lost from the cells and quantitatively replaced by sodium with little, if any, osmotic disturbance. The mean rate of loss at 20,000 r and 24°C. is about 0.4 per cent of the initial cell potassium per hour and approximately doubles for a 20,000 r increase. It is accentuated if blood is stored at low temperature (5°C.) following radiation exposure. Isotope experiments show that the rate of entrance of potassium into the cells is practically unaltered, the principal effect being an acceleration of the rate from cells to plasma. This suggests that radiation may have interfered with a mechanism of selective potassium accumulation based on preferential retention of the element. The sodium which enters the cells following irradiation contributes to the rapidly exchanging portion of the cellular sodium, suggesting that this fraction is ionic sodium.

Electron microscope study of red cell membranes after experimental infection with the virus of foot-and-mouth disease

Guinea pigs were inoculated with the Vallée O type strain of the virus of foot-and-mouth disease. 42 to 48 hours after inoculation red blood cells washed in saline were found to be infective for normal guinea pigs suggesting that erythrocytes carry virus entities at the height of generalization of the disease. This infection is no longer obtained at 92 hours after inoculation when general symptoms of the disease decline. A replica-transfer technique was developed with which hemolyzed blood smears could be observed under the electron microscope. By direct examination and also shadow-casting with palladium, normal red cell membranes show only a very fine structure on the surface. Rounded masses of high electron density appear in the ghosts between 24 and 72 hours after inoculation with virus. The number and particularly the density of these masses tend to increase from 24 to 42 and 72 hours. In some cases they are disposed preferentially in single lines forming ring figures; in other cases they are distributed at random. At 42 hours after inoculation it was possible to detect dense particles of 20 to 70 mµ. within the masses. Measurements of 100 masses at 72 hours gave results ranging from 116 to 437 mµ with a mean diameter of 246 mµ. Results based on 105 electron micrographs and on thousands of cells demonstrate that practically all red cell membranes contained dense masses 24 to 72 hours after inoculation. 92 hours after inoculation, coinciding with the disappearance of infectivity of the erythrocytes, the masses could no longer be seen and the membranes looked entirely normal. Although the facts reported here may be suggestive of a relationship between the dense masses within the red cell membranes and the presence of virus entities in washed erythrocytes, no definite interpretation of these findings is postulated at present.