Effect of Ethanol, Diphenylhydantoin, Methotrexate and Low Sodium Ion Concentration on Jejunal Surface pH and Folic Acid Transfer in the Rat

1978 ◽  
Vol 6 (1) ◽  
pp. 297-299 ◽  
Author(s):  
MICHAEL L. LUCAS ◽  
SARA K. SWANSTON ◽  
FUNG HAN LEI ◽  
PAYUNG MANGKORNTHONG ◽  
JOHN A. BLAIR
Keyword(s):  
Folic Acid ◽  
Sodium Ion ◽  
Ion Concentration ◽  
Surface Ph ◽  
Low Sodium

scholarly journals Identification of a Meningococcal l-Glutamate ABC Transporter Operon Essential for Growth in Low-Sodium Environments

2006 ◽  
Vol 74 (3) ◽  
pp. 1725-1740 ◽  
Author(s):  
Caterina Monaco ◽  
Adelfia Talà ◽  
Maria Rita Spinosa ◽  
Cinzia Progida ◽  
Eleanna De Nitto ◽  
...  
Keyword(s):  
Abc Transporter ◽  
Cell Invasion ◽  
Mutant Cell ◽  
Defined Medium ◽  
Sodium Ion ◽  
Ion Concentration ◽  
Low Sodium ◽  
Defective Mutant ◽  
Secondary Transporter ◽  
Genes Encoding

ABSTRACT GdhR is a meningococcal transcriptional regulator that was previously shown to positively control the expression of gdhA, encoding the NADP-specific l-glutamate dehydrogenase (NADP-GDH), in response to the growth phase and/or to the carbon source. In this study we used reverse transcriptase-PCR-differential display (to identify additional GdhR-regulated genes. The results indicated that GdhR, in addition to NADP-GDH, controls the expression of a number of genes involved in glucose catabolism by the Entner-Doudoroff pathway and in l-glutamate import by an unknown ABC transport system. The genes encoding the putative periplasmic substrate-binding protein (NMB1963) and the permease (NMB1965) of the ABC transporter were genetically inactivated. Uptake experiments demonstrated an impairment of l-glutamate import in the NMB1965-defective mutant in the absence or in the presence of a low sodium ion concentration. In contrast, at a sodium ion concentration above 60 mM, the uptake defect disappeared, possibly because the activity of a sodium-driven secondary transporter became predominant. Indeed, the NMB1965-defective mutant was unable to grow at a low sodium ion concentration (<20 mM) in a chemically defined medium containing l-glutamate and four other amino acids that supported meningococcal growth, but it grew when the sodium ion concentration was raised to higher values (>60 mM). The same growth phenotype was observed in the NMB1963-defective mutant. Cell invasion and intracellular persistence assays and expression data during cell invasion provided evidence that the l-glutamate ABC transporter, tentatively named GltT, was critical for meningococcal adaptation in the low-sodium intracellular environment.

Sodium-Induced Changes in the Nuclei of Monolayer Hela Cultures

1972 ◽  
Vol 11 (3) ◽  
pp. 669-673
Author(s):  
K. JOBST ◽  
N. KELLERMAYER
Keyword(s):  
Culture Medium ◽  
Structural Rearrangement ◽  
Sodium Ion ◽  
Ion Concentration ◽  
Sodium Ions ◽  
Hypertonic Medium ◽  
Low Sodium ◽  
Large Numbers ◽  
Induced Changes ◽  
Cells Cultured

In HeLa cells cultured in a medium containing 142 mequiv./l. sodium ions only the mitotic forms are birefringent (anisotropic index, 27/1000). In a culture medium containing 155-160 mequiv./l. sodium ions, large numbers of nuclear forms reminiscent of the prophase were found. In such a medium the anisotropic index was 86/1000. At low sodium ion concentration (90-110 mequiv./l.) these anomalous, prophase-like forms were not seen and the anisotropic index was 18/1000. The appearance of the birefringent, prophase-like forms is related to a structural rearrangement and condensation of DNP in a hypertonic medium.

Effects of sodium ion and solution tonicity on reactivities of hypertensive rat aortic strips

1960 ◽  
Vol 198 (5) ◽  
pp. 1019-1022 ◽  
Author(s):  
Samuel Mallov
Keyword(s):  
Drinking Water ◽  
Sodium Ion ◽  
Ion Concentration ◽  
Nacl Solution ◽  
Hypertensive Rats ◽  
Initial Tension ◽  
Low Concentration ◽  
Ion Concentrations ◽  
Low Sodium ◽  
Hypertensive Rat

Rats were rendered hypertensive by injecting DCA and feeding 1% NaCl solution in place of drinking water. Isometric tensions developed by strips of aorta from these rats, when exposed to a low concentration of epinephrine, were compared with tensions developed by strips from normotensive controls, under conditions of varying Na ion concentration and solution tonicity. Solutions with high Na ion concentrations (hypertonic), and normal solutions rendered equivalently hypertonic by the addition of sucrose, increased the reactivities of strips from normotensive rats, but decreased the reactivities of strips from hypertensive rats, to added epinephrine. The hypertensive rat strips manifested increases in tension in these solutions even prior to the addition of epinephrine, so that the subsequent smaller responses to epinephrine may have been related to these initial tension increases. Low sodium ion concentrations in hypotonic solutions, but not in isotonic solutions, decreased the reactivities of both hypertensive and normotensive rat strips. These results are interpreted to mean that aortas from hypertensive rats are so changed structurally and functionally, that they respond differently than do normal aortas to increased sodium ion concentrations and/or hypertonic solutions, as well as to epinephrine in such solutions.

Residual phase lignin in haft cooking related to the conditions in the cook

1997 ◽  
Vol 12 (4) ◽  
pp. 225-229
Author(s):  
Cart-in A-S. Gustavsson ◽  
Chritofer T. Lindgren ◽  
Mikael E. Lindström
Keyword(s):  
Hydrogen Sulfide ◽  
Ionic Strength ◽  
Sodium Ion ◽  
Ion Concentration ◽  
Constant Composition ◽  
Hydroxide Ion ◽  
Sulfide Ion ◽  
Residual Phase ◽  
Kraft Cooking ◽  
Very High

Abstract The amount of lignin reacting according to the slow residual phase, i.e. the residual phase lignin, is in many perspectives an interesting issue. The purpose of the present investigation was to develop a mathematical model to show how the amount of residual phase lignin in the kraft cooking of spruce chips (Picm ahies) depends on the conditions in the earlier phases of the cook. The variables studied were hydroxide ion concentration, hydrogen sulfide ion concentration and ionic strength. The liquor-to-wood ratio during pulping was very high to maintain approximately constant chemical concentrations throughout each experiment (so called "constant composition" cooks). An increase in hydroxide ion concentration andtor hydrogen sulfide ion concentration leads to a decrease in the amount of residual phase lignin, while an increase in ionic strength, i.e. sodium ion concentration, leads to an increase. A signiticant result is that the hydrogen sulfide ion concentration has a pronounced influence on the amount of residual phase lignin during a cook at a low hydroxide ion concentration. The amount of residual phase lignin expressed as % lignin on wood, L,, can be described by the following equation developed for "constant composition" cooks (when cooking with a constant sodium ion concentration of 2 mol/L): LT=0,55-0.32*[HO-](-1,3)*ln[HS-] This equation is valid for a concentration of HO- in the range from 0.17 to 1.4, and a hydrogen sulfide ion concentration from 0.07 to 0.6 mol/L.

scholarly journals ALKALOSIS VERSUS ABNORMAL SODIUM ION CONCENTRATION AS A CAUSE OF TETANY

1923 ◽  
Vol 57 (1) ◽  
pp. 47-63
Author(s):  
W. Denis ◽  
L. von Meysenbug ◽  
Julia Goddard
Keyword(s):  
Sodium Ion ◽  
Ion Concentration

Adsorption of sodium cyclododecylmethanoate and cycloundecylmethanoate at the air/water interface

1984 ◽  
Vol 62 (11) ◽  
pp. 2359-2363 ◽  
Author(s):  
Jan J. Spitzer
Keyword(s):  
Aqueous Solutions ◽  
Sodium Ion ◽  
Ion Concentration ◽  
Ionic Surfactants ◽  
Free Energies ◽  
Straight Chain ◽  
Double Chain ◽  
Adsorbed State ◽  
Critical Micelle Concentrations ◽  
Air Water Interface

Surface tension measurements on aqueous solutions of sodium cyclododecylmethanoate and sodium cycloundecylmethanoate in sodium carbonate/bicarbonate buffers and at constant sodium ion concentration at 25 °C were used to obtain the standard free energies of adsorption, the saturation areas per surfactant ion, and the critical "micelle" concentrations of these compounds. Similar measurements were done for solutions of sodium dodecanoate for comparisons.The standard free energies of adsorption of CH2 group that is located in a macrocyclic cycloalkyl ring appears to follow the "rule of two" (−RT ln 2) that is also valid for straight chain ionic surfactants. The saturation areas of both cyclododecylmethanoate and cycloundecylmethanoate are about 52 Å2/ion as compared to about 32 Å2/ion for normal dodecanoate.For large ring cycloalkylmethanoates the critical "micelle" concentrations appear to decrease by a factor of about 4/5 for each CH2 group added to the ring as compared to the factor of about 1/2 for each CH2 group added to the chain of normal alkanoates. The data suggest that large cycloalkyl rings have "collapsed ring", or "double chain", conformation in aqueous solutions and in the adsorbed state.

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