Abrupt osmotic changes during rapid correction of chronic hyponatremia result in demyelinative brain lesions, but the sequence of events linking rapid osmotic changes to myelin loss is not yet understood. Here, in a rat model of osmotic demyelination syndrome, we found that massive astrocyte death occurred after rapid correction of hyponatremia, delineating the regions of future myelin loss. As...

Method for production and regeneration of Acetobacter pasterianus protoplasts is described. The protoplasts were obtained by treatment of cells with lysozyme in protoplast buffer at pH 8.0 with different osmotic stabilizers. The protoplasts were regenerated on Acetobacter medium with various osmotic stabilizers. Maximum protoplast formation was obtained in protoplast buffer with NaCl (0.5M) as ...

We have investigated the effect on the osmotic activation of rat liver lysosomes, by glucose penetration, of different substances known to inhibit the glucose transport through the plasma membrane. Diethylstilbestrol is the most efficient, particularly when purified lysosomes are used. It has no effect on osmotic activation induced by hypo-osmotic sucrose or by iso-osmotic KCl. It is proposed t...

Cells swell in response a hypoosmotic challenge. By converting osmotic pressure to hydrostatic pressure at the cell membrane via van't Hoff's law, and converting that to tension via Laplace's law one predicts that the cell membrane should stretch and become stiff. We tested this prediction using the atomic force microscopy. During osmotic swelling cells did not become stiff and generally became...

BACKGROUND Assessment of sperm morphology (including morphometry) is extensively used to determine one of the qualities of a semen sample and depends on the differential staining of spermatozoa. A staining technique should cause as little change to sperm dimensions and form as possible in order to reliably evaluate the morphometric features of the sperm. Various staining techniques have been em...

This paper criticizes the model and the new definition for osmotic pressure given by Parsafar et al. [J. Sci. I. R. Iran, Vol. 10, No. 4, 233 (1999)]. The model is a closed system containing 1 kg of solvent plus m mole of solute at constant temperature and under pressure P0 + ? where P0 is the standard pressure and ? is the osmotic pressure of the corresponding m molal solution. While the total...

Osmotic stress produced by high concentrations of sucrose stimulated the high-affinity transport of glutamine in Escherichia coli cells. Glutamine transport via a low-affinity system was not affected. Osmotic stress produced by NaCl, in contrast, inhibited the transport of glutamine and some other amino acids. Maltose transport was strongly inhibited by osmotic stress.

The osmotic pressure of solutions in the ventral sac of the rumen of the conscious cow was varied with Na Cl or mannitol. The mucosal blood flow measured by HTO clearance was minimal when the lumen contained an isotonic solution and rose threefold when the rumen was hypo- or hypertonic to plasma by 150 mosmol/kg. Thus osmotic gradients actoss the rumen epithelium stimulated mucosal blood flow. ...

The relationship between left ventricular filling pressure and plasma colloid osmotic pressure to pulmonary edema was examined in a group of 37 patients, the majority of whom were hypovolemic. Sixteen patients developed pulmonary edema during fluid infusion. In the 21 patients who did not develop pulmonary edema, the left ventricular filling pressure was slightly elevated but the colloid osmoti...

The addition of lead to normal human blood was previously found to cause a decrease in erythrocyte osmotic fragility in vitro. The mechanism of the decreased osmotic fragility caused by lead has not been completely clarified, but the following hypothesis has been proposed. Lead causes a leakage of water from erythrocytes, thus more water can enter the cell before haemolysis occurs. There has be...