Fundamental cryobiological characteristics of rhesus spermatozoa must be determined for successful cryopreservation techniques to be established. The main objectives of the present study were to determine the osmotic behavior and osmotic tolerance limits of rhesus macaque spermatozoa. Cell volume changes over anisotonic conditions were assessed using an electronic particle counter and sperm mot...

Sunmntary. Satisfactory measurements of phloem water potential of trees can be obtained with the Richards and Ogata psychrometer and the vapor equilibration techniques, although corrections for loss of dry weight and for heating by respiration are required for the vapor equilibrium values. The psychrometer technique is the more satisfactory of the 2 because it requires less time for equilibrati...

The pathogenesis of mucoinfective lung disease in cystic fibrosis (CF) patients likely involves poor mucus clearance. A recent model of mucus clearance predicts that mucus flow depends on the relative mucin concentration of the mucus layer compared with that of the periciliary layer; however, mucin concentrations have been difficult to measure in CF secretions. Here, we have shown that the conc...

The effect of cefmetazole, a broad-spectrum cephalosporin, on bile flow and composition in rats was studied. Intravenous injection of cefmetazole at doses ranging from 40 to 400 mumol/kg of body weight led to an increase in its biliary concentration and excretion rate, with a maximum at 30 min after injection. Excretion of cefmetazole into bile was associated with a marked choleresis. The magni...

MCBEAN, RALPH L., AND LEON GOLDSTEIN. Renal function during osmotic stress in the aquatic toad Xenopus laevis. Am. J. Physiol. 2 19 (4) : 1115-1123. 1970.~Xenopus toads, which are normally aquatic and arnmonotelic, became ureotelic after maintenance in a hyperosmotic saline solution for 2-3 weeks. In addition, blood urea levels were elevated more than 15-fold, and this increase contributed sign...

Background: Recurrent abortion is defined as three or more consecutive pregnancy losses. We aimed to determine the relationship between male sperm parameters and hypo-osmotic swelling score and recurrent abortion. We also studied whether washing of spermatozoa and intrauterine insemination in patients with recurrent miscarriage and low score hypo-osmotic swelling test in male partners could imp...

Through most of his career, Arthur Ramsay was fascinated by matters osmotic. In the period after the Second World War, he worked on osmotic relations of the earthworm (Ramsay, 1949a), developing typically novel methods for measuring the melting-point and sodium content of minute quantities of fluids (Ramsay, 1949b, 1950). However, in the early 1950s, Ramsay started working on insect Malpighian ...

AIM To quantify the exchange of water between cerebral compartments, specifically blood, tissue, perivascular pathways, and cerebrospinal fluid-filled spaces, on the basis of experimental data and to propose a dynamic global model of water flux through the entire brain to elucidate functionally relevant fluid exchange phenomena. METHODS The mechanistic computer model to predict brain water sh...

Valinomycin and gramicidin D were used to test the hypothesis that a lipoprotein membrane is the osmotic barrier in mature root systems. Hydroponically grown soybean (var. Ranson) root systems were pressurized in steps between 0.2 and 5.0 bars at 25 C. Steady-state flow rates and exudate osmotic potentials were measured at each pressure. Valinomycin or gramicidin D to a final concentration of 2...

Water movement occurs to a variable degree across every epithelial layer of cells and plays a determinant role in the homeostasis of body fluid balance. Is such water transport the result of a difference of water activity or osmotic pressure across the epithelium? The answer to that question is more often negative as demonstrated by the phenomenon of isotonic water movement. Many epithelia tran...