Permeability chloride

Cystic fibrosis (CF) is caused by mutations in the CF transmembrane conductance regulator (CFTR), a chloride (CF) channel characterised by chloride permeability and secretion, and also by the regulation of other epithelial ion channels (Eidelman et al, 2001). Mutations in the CFTR gene lead to an impaired or absent Cl conductance in the epithelial apical membrane, which leads to defective Cl secretion and absorption across the epithelium. Genistein (Illek et al, 1995 Weinreich et al, 1997) and other flavonoids (Illek and Fisher, 1998) have been shown, in different animal and tissue models, to activate wild-type CFTR and CFTR mutants by (Eidelman et al, 2001 Roomans, 2001 Suaud et al, 2002) ... 

Olsen JC, Johnson LG, Stutts MJ, Sarkadi B, Yankaskas JR, Swanstrom R, Boucher RC (1992) Correction of the apical membrane chloride permeability defect in polarized cystic fibrosis airway epithelia following retroviral-mediated gene transfer. Hum Gene Ther 3(3) 253-266. 

R,(C.) on Table 5 are shown in Figure 12 where pure water and sodium chloride permeabilities in homogeneous membranes obtained by Lonsdale etal( ) are also shown. 

Procedure of Analysis. Rate constant can be calculated as a slope of the line plotted right hand side of equation ( ) against time elasped. At first acetyl content is estimated from the ratio of sodium chloride permeability of the deteriorated membrane and the initial by Fig.12. Using the estimated acetyl content, and f2(CA) can be obtained from Fig. 12. Using these values and f ... 

Whereas benzodiazepines possessing agonist activity indirectly augment chloride permeability, inverse agonists exert an opposite action. These substances give rise to pronounced restlessness, excitement, anxiety, and convulsive seizures. There is, as yet, no therapeutic indication for their use. 

The rat Cx40 channel exhibits a detectable chloride permeability of 0.29 relative to potassium [Beblo et al., 1995]. This indicates some selectivity for cations over anions as well. These channels were also permeable to 2, 7 -dichlorofluorescein and to the more polar 6-carboxyfluorescein dye. Interestingly, the 2, 7 -dichlorofluorescein permeability did not increase with increasing junctional conductance in that study. 

Blair HC, Teitelbaum SL, Tan HL, Koziol CM, Schlesinger PH. 1991. Passive chloride permeability charge coupled to H+-ATPase of avian osteoclast raffled membrane. Am J Physiol 260 C1315-24. 

Figure 5.5 Water permeability as a function of sodium chloride permeability for membranes made from cellulose acetate of various degrees of acetylation. The expected rejection coefficients for these membranes, calculated for dilute salt solutions using Equation (5.6),...

Activation of calcium permeable receptors such as purinergic P2X receptor or NMDA receptor delayed the barrier recovery after barrier disruption and enhanced epidermal hyperplasia induced by barrier disruption.45-47 Topical application of antagonists of these receptors prevented these pathological changes. On the other hand, topical application of agonists of chloride permeable receptors such as GABA(A) receptor or glycine receptor accelerated the barrier repair and prevented the epidermal hyperplasia 46... 

Bettendorff L, Hennuy B, De Clerck A, and Wins P (1994) Chloride permeability of rat brain membrane vesicles correlates with thiamine triphosphate content. Brain Research 652, 157-60. 

There are five macrocyclic lactones utilized in veterinary practice of which ivermectin (an aver-mectin) and moxidectin (a milbemycin) are approved for use in the horse. Ivermectin and moxidectin selectively paralyze parasites by increasing muscle chloride permeability through interaction with glutamate-gated chloride ion channels (McKellar Benchaoui 1996). There is evidence that ivermectin and moxidectin may have several sites of action within the parasite and the effects of these compounds may also differ between the nematode species (McKellar Benchaoui 1996, Martin 1997). 

Table 10. Results of Rapid Chloride Permeability Test of RPUMRPE and HRPE...

There is some recent evidence that the chloride permeability determined by exchange measurements is much greater than that determined by net translocation (38). However, throughout this work a counteranion was always available, so the use of the high (10"4 cm/sec) permeability value seems justified since all movements of chloride ions occur under exchange conditions. 

Type of Project Location Overlay Thickness (mm) Age at Test Chloride Permeability (coulombs) ... 

Whiting, D., Rapid Determination of the Chloride Permeability of Concrete, FHWA/RD-81/119,174p, Portland Cement Association, Skokie, Illinois (Aug. 1981)... 

In addition to low chloride permeability, mineral admixtures impart other properties to the concrete depending on the admixture selected such as ... 

Recently, Kobayashi et al. (2010) also studied the chloride penetration into the cracked HPFRCC material. In their study, several concrete beams were prepared, and the bottom layer surrounding the reinforcing steel was repaired using HPFRCC and repair mortar (polymer cement mortar [PCM]). Cracks were introduced in the specimens by uniaxial tension. The maximum crack widths in the HPFRCC repair layer and PCM layer were 0.06 and 0.43 mm, respectively. The specimens were then subjected to saltwater (containing 3% NaCl) spray for 5 min every 6 h and continned for 2 months. Similar to Miyazato and Hiraishi (2005), the AgNOj solution was also sprayed on the fractured surface to measure the chloride penetration depth. Reduced chloride penetration in cracked HPFRCC compared to PCM was reported in their study (Figure 6.10). The above results on the permeability of HPFRCC show that it has very low water and chloride permeability even in the crack state. 

Due to its small crack width properties, the water and chloride permeability of cracked HPFRCC are comparable to those in the uncracked state. 

The alternative is to take cores and do laboratory tests of chloride permeability. This is slow, expensive and damaging to the structure. There is now a European Standard 1062-3 for water transmission through coatings for concrete (BSI, 1999). 

Table 2. Workability, strength and resistance to chloride permeability of concretes. 

Motais, R., Sola, F. and Cousin, J. L. (1978) Uncouplers of oxidative phosphorylation. A structure-activity study of their inhibitory effect on passive chloride permeability. Biochim. Biophys. Acta, 510, 201-7. 

The charges passing thi ough concrete with Pure-slag powder (Concrete 1 series) or with the Compound-slag powder (Concrete 2 series) were tested (Figure 7). Chloride permeability... 

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