THE AGGLUTINATION OF RED BLOOD CELLS IN THE PRESENCE OF BLOOD SERA

1. The addition of blood serum displaces the optimum for agglutination of red blood cells in a salt-free medium to the reaction characteristic of flocculation of the serum euglobulin. 2. This effect is not due merely to a mechanical entanglement of the cells by the precipitating euglobulin, since at reactions at which the latter is soluble it protects the cells from the agglutination which occurs in its absence. 3. A combination of some sort appears therefore to take place between sheep cells and sheep, rabbit, and guinea pig serum euglobulin, and involves a condensation of the serum protein upon the surface of the red cell. 4. At the optimal point for agglutination of persensitized cells both mid- and end-piece of complement combine with the cells. 5. Agglutination is closely related to an optimal H ion concentration in the suspending fluid, and probably of the cell membrane, and not to a definite reaction in the interior of the cell.     

THE ISOELECTRIC POINT OF RED BLOOD CELLS AND ITS RELATION TO AGGLUTINATION

1. The movement of normal and sensitized red blood cells in the electric field is a function of the hydrogen ion concentration. The isoelectric point, at which no movement occurs, corresponds with pH 4.6. 2. On the alkaline side of the isoelectric point the charge carried is negative and increases with the alkalinity. On the acid side the charge is positive and increases with the acidity. 3. On the alkaline side at least the charge carried by sensitized cells is smaller and increases less rapidly with the alkalinity than the charge of normal cells. 4. Both normal and sensitized cells combine chemically with inorganic ions, and the isoelectric point is a turning point for this chemical behavior. On the acid side the cells combine with the hydrogen and chlorine ions, and in much larger amount than on the alkaline side; on the alkaline side the cells combine with a cation (Ba), and in larger amount than on the acid side. This behavior corresponds with that found by Loeb for gelatin. 5. The optimum for agglutination of normal cells is at pH 4.75, so that at this point the cells exist most nearly pure, or least combined with anion and cation. 6. The optimum for agglutination of sensitized cells is at pH 5.3. This point is probably connected with the optimum for flocculation of the immune serum body.     

THE CATAPHORETIC VELOCITY OF MAMMALIAN RED BLOOD CELLS

1. No significant change with time (to 24 hours) in the cataphoretic velocity of certain mammalian red cells occurs when the cells are suspended in M/15 phosphate buffer at pH = 7.35. Neither successive washings nor standing effect a change. 2. In M/15 phosphate buffer at pH 7.35 ± 0.03 the following order of red cell velocity has been obtained. The numbers in parenthesis are µ per second per volt per centimeter. See PDF for Structure The order, though not the absolute values, was the same in buffered isotonic dextrose. Human and rabbit cells showed similar differences when both were studied simultaneously in the serum of either. Under these conditions, there is no apparent relationship between zoological Order and cataphoretic velocity. 3. Cholesterol and quartz adsorb gelatin from dilute solution in the phosphate buffer. Red cells, on the other hand, even after 24 hours contact with gelatin solution, retain their previous velocity. 4. Pregnant and non-pregnant white female humans have the same red cell cataphoretic velocity. (The cells were not agglutinated.) 5. In a series of severe anemias no significant change in cataphoretic velocity was in general apparent, although marked changes in the morphology of the red cells were present.     

THE ELECTRICAL CHARGE OF MAMMALIAN RED BLOOD CELLS

In Vol. 19, No. 4, March 20, 1936, page 603, in the eleventh line from the bottom of the page for "z_j = 2, z_jj = 1", read "z_j = 1, z_jj = 2". On the same page in the fourteenth line from the bottom of the page for "jj(HPO₄-)" read "jj(HPO₄--)".     

MEMBRANE EQUILIBRIA AND THE ELECTRIC CHARGE OF RED BLOOD CELLS

It has been shown, within the probable limit of error of the methods of measurement employed, that the Donnan equilibrium determines the distribution of H and Cl ions between the cell and the surrounding fluid. This equilibrium is a consequence of the impermeability of the cell membrane to the inorganic cations of the cell. The mechanism responsible for this equilibrium is suggested as that concerned in the secretion of HCl by the cells of the gastric mucosa. If the salt concentration of the medium is low there may result from the Donnan equilibrium a thermodynamic P.D. of considerable magnitude. In the presence of low concentrations of electrolytes, this P.D. is to be regarded as positive in sign at reactions of the medium at which the cataphoretic charge of the cell is negative in sign. The explanation of this discrepancy in sign of charge may lie in the existence at an outer phase-boundary of a second Donnan equilibrium the nature of which is determined by the ionization of the protein of the cell membrane.     

THE THICKNESS OF THE WALL OF THE RED BLOOD CORPUSCLE

Fricke''s assumption, that the dielectric constant of the erythrocyte wall is 3, is discussed. The assumption is approximately correct in the case of a solid layer of any thickness, and in the case of a liquid layer of not more than bimolecular thickness. For liquid layers of greater thickness the dielectric constant may be several times greater than 3. Calculated values based on experimental determinations are given of the dielectric constants of the polar groups of unimolecular films.     

THE EFFECT OF VALENCY OF CATIONS AND ANIONS ON NEGATIVELY AND POSITIVELY CHARGED RED BLOOD CELLS

1. Under comparable conditions, valency effect may be demonstrated with a suspension of red blood cells and the cations and anions of salts. 2. The valency of the cation determines the degree of the effect on negatively charged cells, the valency of the anion, the effect on positively charged cells. 3. Anomalies in valency effects with different salts and red cell suspensions are in part due to variations in H ion concentration, depending on the degree of hydrolysis of the salt.     

THE OSMOTIC BEHAVIOR OF CRENATED RED CELLS

The anomalously small swelling which the red cells of human oxalated blood undergo in hypotonic plasma is related to the extent to which the cells are crenated. Reasons are given for regarding crenation as corresponding to gelation, and the bulk modulus for crenated cells, calculated from the measurements of swelling in hypotonic plasma, is shown to be of the same order as that for gelatin gels.     

THE INFLUENCE OF ELECTROLYTES ON THE STABILITY OF RED BLOOD CORPUSCLE SUSPENSIONS

Two types of stability are observed in suspensions of red blood cells. In weak concentrations of electrolytes the stability depends on the electric charge of the cells and suspension is unstable below a certain critical P.D. In strong concentrations of electrolyte, the stability bears no relation to the charge.     

CHANGES IN THICKNESS OF THE RED BLOOD CORPUSCLE MEMBRANE

Measurements of the static capacity per cm.² of membrane for the red corpuscle as changed when the cells are made spherical by the addition of lecithin or rose bengal, show a slight increase of capacity, indicating a thinning of the membrane, although the change is not large enough to make it certain that it is real. Furthermore, the membrane capacity shows a slight decrease when spherical cells are swollen in hypotonic saline, indicating a thickening of the membrane, although the change is hardly outside the experimental error. The fact that there is no increase in capacity lends support to the theory that as the cell swells the membrane does not stretch but new material comes from the interior of the cell to make a new portion of the membrane.     

THE PROLYTIC LOSS OF K FROM HUMAN RED CELLS

The prolytic loss of K., i.e. the loss of K which takes place from red cells exposed to hypolytic concentrations of lysins, has been measured in systems containing distearyl lecithin, sodium taurocholate, sodium tetradecyl sulfate, saponin, and digitonin, by means of the flame photometer. The lysins are added in various concentrations to washed red cells from heparinized human blood, and the K in the supernatant fluids is determined after various intervals of time and at various temperatures. The prolytic loss K_p is compared in every experiment with the loss K_s into standard systems containing isotonic NaCl alone, with no lysin. The losses K_s and K_p increase with time, so that new steady states are approached logarithmically. The values of K_p which correspond to the new steady states depend on the lysin used, being greatest with taurocholate and smallest with digitonin. The temperature coefficient of the loss is positive, and the extent and course of the losses have no apparent relation to the prolytic shape changes. In systems in which the loss of K is appreciable, it can be inhibited by the addition of plasma or of either cholesterol or serum albumin. Of these two substances, even when used in quantities which have an approximately equal effect in inhibiting hemolysis, serum albumin is much the more effective. Just as the prolytic loss of K occurs without the loss of any Hb, so in concentrations of lysin sufficient to produce hemolysis the loss of K, expressed as a percentage of the total red cell K, increases much more rapidly with lysin concentration than does the loss of Hb expressed as a percentage of the total Hb. The explanation of these relations depends on whether the loss of K is treated as being all-or-none in the case of the individual cell or as being the result of the loss of part of the K from all of the cells. This point has still to be decided.     

THE EQUILIBRIUM BETWEEN HEMOLYTIC SENSITIZER AND RED BLOOD CELLS IN RELATION TO THE HYDROGEN ION CONCENTRATION

1. In a salt-free medium the proportion of the total amount of hemolytic sensitizer present, combined with the homologous cells, reaches a maximum of almost 100 per cent at pH 5.3. On the alkaline side of this point the proportion combined diminishes with the alkalinity and reaches a minimum of approximately 5 per cent at pH 10. On the acid side of pH 5.3 the proportion combined diminishes with the acidity but somewhat less rapidly than for a corresponding increase in alkalinity. 2. The presence of NaCl greatly increases the proportion of sensitizer combined with cells at all reactions except those in the neighborhood of pH 5.3. At this point the combination of sensitizer with cells is independent of the presence of electrolyte. 3. The curves representing the proportion of sensitizer combined or free run almost exactly parallel, both when the sensitizer combines de novo and when it dissociates from combination; therefore, in constant volume, at a given hydrogen ion concentration, and at a given temperature, an equilibrium exists between the amount of sensitizer free and that combined with cells. 4. The combination of sensitizer and cells is related fundamentally to the isoelectric point of the sensitizer. 5. The dissociated ions of the sensitizer, formed either by its acid or its basic dissociation, do not unite with cells. Combination takes place only between the cells and the undissociated molecules of the sensitizer.     

急进高原人群血浆NO和红细胞SOD变化

目的：本文旨在探讨急进高原低氧人群血浆ＮＯ和红细胞ＳＯＤ的变化及其相互作用的生理意义。方法：以急进高原的健康人群为研究对象,年龄范围在１８～２１岁之间,分为对照组和高原低氧组。血浆ＮＯ测定采用硝酸还原酶法,红细胞ＳＯＤ测定采用亚硝酸盐显色法。结果：高原低氧组血浆ＮＯ浓度显著低于平原对照组;高原低氧组红细胞ＳＯＤ含量显著高于平原对照组。结论：急进高原低氧人群红细胞ＳＯＤ显著升高,ＮＯ降低,可能与低氧造成肺血管收缩有关系。但ＮＯ、自由基及自由基清除剂（ＳＯＤ）之间的调控网络,在低氧的病理生理过程中的作用有待进一步研究     

THE PATTERN OF DNA SYNTHESIS IN THE CHROMOSOMES OF HUMAN BLOOD CELLS

The sequence in which various regions of the chromosomes of human blood cells complete DNA synthesis in vitro has been studied through the use of H³-thymidine labeling and autoradiography. Certain of its aspects have been defined, and these may serve as a basis for comparing the pattern of synthesis in cells of other tissues. In general, the long chromosomes continue replication later than the short ones. Variability of the sequence has been prominent. One pair from Group 13–15 and pair No. 17 complete replication early. In certain other chromosomes, replication is very active late in the S period, e.g. one X of the female cell, the Y of the male cell, two of Group 4–5, two of Group 13–15, the Nos. 16, and the Nos. 18. In the normal human female a striking correlation exists between the late replication of one of the X chromosomes, condensation during the intermitotic period, and presumed genetical inactivation. The pattern of replication characterizes certain chromosomes whose structural features alone are non-distinctive, and it may be useful in studies of cells in which a chromosomal aberration occurs.     

CONCANAVALIN A-INDUCED AGGLUTINATION AND BINDING OF CON A TO THE DIFFERENTIATING CELLS OF DICTYOSTELIUM DISCOIDEUM

Changes in agglutinability of Dictyostelium discoideum cells with Concanavalin A (Con A) during the course of development were investigated. The agglutinability of the cells was assayed under conditions where no spontaneous cell agglutination occurred. It was found that there was a progressive decrease in Con A-induced agglutinability during development: a decrease to half from exponentially growing cells to preaggregation cells, and to sixth in disaggregated slug cells. Pronase-BAL treatment of preaggregation cells did not enhance their agglutinability with Con A. The amounts of sites available for binding Con A were determined with preaggregation and slug cells. Cells were incubated at 4°C and in the presence of NaN₃ to avoid possible endocytosis of Con A. No significant differences in numbers of Con A-binding sites per unit area of cell surface was detected among preaggregation cells, those treated with pronase and BAL and cells disaggregated from slugs by similar treatment. It was thus concluded that the decrease in Con A-induced agglutinability during development is not attributable to changes in the numbers of Con A-binding sites.