Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Chlorides”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 127 records · Page 7Linked to original sources
PubMed1979

Mutagenicity of vinyl chloride, vinylidene chloride and chloroprene in V79 Chinese hamster cells.

The mutagenicity of vinyl chloride, vinylidene chloride (1,1-dichloroethylene) and chloroprene (2-chloro-1,3-butadiene) was tested in V79 Chinese hamster cells in the presence of a 15 000 x g liver supernatant from phenobarbitone-pre-treated rats and mice. Mutations in terms of 8-azaguanine and ouabain resistance were induced in a dose-related fasion by exposure to vapour of vinyl chloride in the presence of liver supernatant from phenobarbitone-pretreated rats. Vapours of vinylidene chloride and chloroprene induced a dose-related toxicity in the presence of liver supernatant from phenobarbitone-retreated rats, but these two compounds were not mutagenic in V79 Chinese hamster cells under the present assay conditions. The results are discussed with regard to the metabolic activation of the compounds and to the correlation with their carcinogenicity in man and experimental animals.

Animals↗
PubMed2000

A genetically encoded ratiometric indicator for chloride: capturing chloride transients in cultured hippocampal neurons.

We constructed a novel optical indicator for chloride ions by fusing the chloride-sensitive yellow fluorescent protein with the chloride-insensitive cyan fluorescent protein. The ratio of FRET-dependent emission of these fluorophores varied in proportion to the concentration of Cl and was used to measure intracellular chloride concentration ([Cl-]i) in cultured hippocampal neurons. [Cl-]i decreased during neuronal development, consistent with the shift from excitation to inhibition during maturation of GABAergic synapses. Focal activation of GABAA receptors caused large changes in [Cl-]i that could underlie use-dependent depression of GABA-dependent synaptic transmission. GABA-induced changes in somatic [Cl-]i spread into dendrites, suggesting that [Cl-]i can signal the location of synaptic activity. This genetically encoded indicator will permit new approaches ranging from high-throughput drug screening to direct recordings of synaptic Cl- signals in vivo.

Animals↗
PubMed2000

Cystic fibrosis transmembrane conductance regulator and the outwardly rectifying chloride channel: a relationship between two chloride channels expressed in epithelial cells.

1. Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) result in the primary defect observed in patients with cystic fibrosis. 2. The CFTR is a member of the ATPase-binding cassette (ABC) transporter family but, unlike other members of this group, CFTR conducts a chloride current that is activated by cAMP. 3. In epithelial cells, the cAMP-stimulated chloride current is conducted by both CFTR and the outwardly rectifying chloride channel (ORCC). 4. The present review summarizes the current knowledge of the properties of the two channels, as well as their relationship. Because the gene encoding the ORCC has not been identified, a discussion as to possible candidates for this chloride channel is included.

Animals↗
PubMed1976

Teleost chloride cell. I. Response of pupfish Cyprinodon variegatus gill Na,K-ATPase and chloride cell fine structure to various high salinity environments.

Certain euryhaline teleosts can tolerate media of very high salinity, i.e. greater than that of seawater itself. The osmotic gradient across the integument of these fish is very high and the key to their survival appears to be the enhanced ability of the gill to excrete excess NaCl. These fish provide an opportunity to study morphological and biochemical aspects of transepithelial salt secretion under conditions of vastly different transport rates. Since the cellular site of gill salt excretion is believed to be the "chloride cell" of the branchial epithelium and since the enzyme Na,K-ATPase has been implicated in salt transport in this and other secretory tissues, we have focused our attention on the differences in chloride cell structure and gill ATPase activity in the variegated pupfish Cyprinodon variegatus adapted to half-strength seawater (50% SW), seawater (100% SW), or double-stregth seawater (200% SW). The Na,K-ATPase activity in gill homogenates was 1.6 times greater in 100% SW. When 50% SW gills were compared to 100% SW gills, differences in chloride cell morphology were minimal. However, chloride cells from 200% SW displayed a marked hypertrophy and a striking increase in basal-lateral cell surface area. These results suggest that there are correlations among higher levels of osmotic stress, basal-lateral extensions of the cell surface, and the activity of the enzyme Na,K-ATPase.

Adenosine Triphosphatases↗
PubMed1981

Transepidermal chloride flux through hydrated skin: combination chloride electrode.

A combination chloride electrode was used to determine quantitatively the outward rate of epidermal chloride transport in vivo. Regional anatomical variation and the effects of topical agents and cellophane tape strippings on the rate of chloride diffusion were determined. Transepidermal chloride flux through hydrated skin appears to be an alternative method for determining stratum corneum function in vivo.

Acetates↗
PubMed1998

Characterization of the putative chloride channel xClC-5 expressed in Xenopus laevis oocytes and comparison with endogenous chloride currents.

1. We recently cloned a putative chloride channel (xClC-5) from the renal cell line A6, which induced the appearance of a Cl- conductance not found in control oocytes after homologous expression in Xenopus oocytes. With the aim of increasing the Xenopus oocyte xClC-5 expression, we constructed a new plasmid in which the native 5' and 3' non-coding regions of xClC-5 were replaced by the non-coding regions of the Xenopus beta-globin sequence and in which a Kozak consensus site was introduced before the initiator ATG. 2. We then compared the induced currents Inative (induced by injection of cRNA presenting the native non-coding regions of xClC-5) and Ibeta-globin (induced by injection of cRNA presenting the non-coding regions of the Xenopus beta-globin sequence) investigating anion selectivity and anion blocker sensitivity. Several differences were found: (1) expression yield and oocyte surviving rate were largely increased by injecting (beta) xClC-5 cRNA, (2) the Ibeta-globin outward rectification score was 2.6 times that of Inative, (3) the anion conductivity sequence was nitrate > bromide > chloride > iodide >> gluconate for Ibeta-globin and iodide > bromide > nitrate > chloride >> gluconate for Inative, (4) 5-nitro-2-(3-phenylpropylamino)-benzoic acid (NPPB), anthracene-9-carboxylic acid (9-AC), DIDS, lanthanum ions, cAMP and ionomycin-induced [Ca2+]i increase inhibited Inative but had no effect on Ibeta-globin, and (5) Inative showed considerable similarity to the previously reported endogenous current appearing after ClC-6 or pICln cRNA injection. 3. Comparison of Inative with the endogenous chloride current ICl,swell which develops under hyposmotic conditions demonstrated several similarities in their electrophysiological and pharmacological characteristics but were nevertheless distinguishable. 4. In vitro translation assays demonstrated that protein synthesis was much greater using the (beta) xClC-5 construct than that of xClC-5. Furthermore, immunoreactivity of membrane preparations of Xenopus oocytes was only observed with the (beta) xClC-5 construct, its intensity being positively correlated with Ibeta-globin levels. 5. In addition, the current induced in (beta) xClC-5 cRNA-injected oocytes presented a very marked pH dependence (inhibition by acid external media) with a pKa value (negative log of the acid dissociation constant) of 5.67. 6. In conclusion, Ibeta-globin may be due to the presence of xClC-5 in the oocyte plasma membrane playing a role as an anion channel whereas Inative may represent an endogenous current induced by xClC-5 cRNA injection. The use of antibodies will facilitate the tissue and subcellular localization of xClC-5 and the identification of its physiological role.

Animals↗
PubMed1977

Sodium chloride transport across the chicken coprodeum. Basic characteristics and dependence on sodium chloride intake.

1. The transport characteristics of the chicken coprodeum have been examined in vitro using the isolated mucosa. The short-circuit current (I(sc)), the transepithelial electrical potential difference (p.d.), the unidirectional transmural fluxes (J(ms), J(sm)) of sodium and chloride measured in the short-circuited state, and the unidirectional influx of sodium and chloride across the brush border membrane measured under open-circuit conditions have been studied. The effect of the sodium chloride contents of the diet on these parameters have been investigated.2. The isolated mucosa depends functionally on the presence of glucose in the incubation media. This dependence reflects the need of glucose as a fuel. There is no indication of coupling between transport of sugars and sodium across the brush border membrane. For preparations from chickens on a low sodium diet a very high and stable I(sc) can quantitatively be accounted for by the net transport of sodium. Influx of sodium across the brush border membrane is not significantly different from the net flux of sodium. By feeding the chickens a high sodium diet the I(sc) is reduced by more than 95%, the net transport of sodium is abolished, and the transepithelial electrical conductance is reduced by more than 50%.3. Both unidirectional transepithelial fluxes of chloride, and the serosa to mucosa flux of sodium appear to proceed through a paracellular shunt.4. Under the conditions of the low sodium diet the paracellular pathway appears to be anion selective. Whereas, under the conditions of the high sodium regimen the paracellular route appears to be cation selective. After adaptation to a high sodium diet the influx of sodium across the brush border membrane is only moderately reduced. Consequently the decisive event in the adaptation must be localized elsewhere.

Animals↗
PubMed1996

The chloride current induced by expression of the protein pICln in Xenopus oocytes differs from the endogenous volume-sensitive chloride current.

1. Phenotypical similarities between ICl,swell, the cell-swelling-induced chloride current and ICln, the nucleotide-sensitive chloride current induced by expression of mammalian pICln in Xenopus oocytes, have led to models which identify pICln either as the volume-sensitive chloride channel or as a cytosolic regulator thereof. 2. To investigate critically the relationship between ICl,swell and pICln two-microelectrode voltage clamp experiments were performed on Xenopus oocytes in which either human pICln was expressed or endogenous ICl,swell was activated. 3. Several criteria that clearly differentiated ICln from ICl,swell were detected. Outward rectification and the discrimination between NO3- and Cl- were more pronounced for ICln. Cyclamate blocked ICln but not ICl,swell. In contrast to ICl,swell, inactivation kinetics of ICln were pH independent and extracellular cAMP blocked only the outward ICln component. Finally, ICln was readily expressed in collagenase-defolliculated oocytes and was not modulated by extracellular hypotonicity, whereas ICl,swell could only be triggered in follicle-enclosed or manually defolliculated oocytes. 4. We therefore conclude that ICln and ICl,swell are two different chloride currents. Consequently, any model which invokes a crucial role for pICln in ICl,swell should be critically reviewed.

Animals↗
PubMed1977

Mortality experience of workers exposed to vinyl chloride monomer in the manufacture of polyvinyl chloride in Great Britain.

Identification particulars were obtained for over 7000 men who were at some time between 1940 and 1974 exposed to vinyl chloride monomer in the manufacture of polyvinyl chloride. Approximately 99% of these men have been traced and their mortality experience studied. The overall standardised mortality ratio, 75-4, shows a significant reduction compared with the national rates. Four cases of liver cancer were found. Two of these have been confirmed by a panel of liver pathologists as angiosarcoma and two as not angiosarcoma. There is no evidence to support the hypothesis that cancers other than those of the liver are associated with exposure to vinyl chloride monomer. The two cases of angiosarcoma were found in men who had been exposed to high concentrations of the monomer although the second man died only eight years after first exposure. The industry in Great Britain has expanded considerably since the second world war with over 50% of men having entered with the last decade. Conclusions drawn about the effect of vinyl chloride monomer on the mortality experience of men in this industry must consequently be tempered by the reservation that the full impact may not yet be in evidence.

Chemical Industry↗
PubMed2006

Mechanisms of net chloride secretion during rotavirus diarrhea in young rabbits: do intestinal villi secrete chloride?

Rotaviral diarrheal illness is one of the most common infectious diseases in children worldwide, but our understanding of its pathophysiology is limited. This study examines whether the enhanced net chloride secretion during rotavirus infection in young rabbits may occur as a result of hypersecretion in crypt cells that would exceed the substantial Cl(-) reabsorption observed in villi. By using a rapid filtration technique, we evaluated transport of (36)Cl and D-(14)C glucose across brush border membrane (BBM) vesicles purified from villus tip and crypt cells isolated in parallel from the entire small intestine. Rotavirus infection impaired SGLT1-mediated Na(+)-D-glucose symport activity in both villus and crypt cell BBM, hence contributing to the massive water loss along the cryptvillus axis. In the same BBM preparations, rotavirus failed to stimulate the Cl(-) transport activities (Cl(-)/H(+) symport, Cl(-)/anion exchange and voltage-activated Cl(-) conductance) at the crypt level, but not at the villus level, questioning, therefore, the origin of net chloride secretion. We propose that the chloride carrier might function in both normal (absorption) and reversed (secretion) modes in villi, depending on the direction of the chloride electrochemical gradient resulting from rotavirus infection, agreeing with our results that rotavirus accelerated both Cl(-) influx and Cl(-) efflux rates across villi BBM.

Animals↗
PubMed1984

[Thallium-201 chloride dynamic analysis using thallium-201 chloride and sodium iodide-131 thyroid subtraction scintigraphy].

The mechanism of 201Tl chloride accumulation is unclear in thyroid gland and thyroid tumor. This report examines 108 patients that received thyroid scintigraphy examinations with both 201Tl chloride and sodium 131I. The patients were diagnosed clinically and histologically whenever possible. The ROI were obtained by subtraction imaging with both isotopes and by subtraction positive and negative areas of imaging. Dynamic curves were obtained for 201Tl chloride per square unit of each ROI. The dynamic curve in the radioiodide-accumulated area was examined. The data indicate that the clearance rate of 201Tl chloride (T15) was correlated with the sodium 131I uptake rate at 24 h (r = 0.70).

Adolescent↗
PubMed2006

[Properties of benzethonium chloride in micellar solutions and the effect of added sodium chloride].

Aqueous solutions of the antimicrobially effective quaternary ammonium salt benzethonium chloride (hyamine 1622) were studied using UV spectrophotometry and partially conductometry. The spectra of micellar solutions of benzethonium chloride revealed a concentration-dependent bathochromic and hyperchromic shift of a weak UV absorption band in the region 250-300 nm. This served to elaborate the spectrophotometric determination of the critical micellar concentration (CMC) of benzethonium chloride and the concentration of free benzethonium cations in micellar solutions without an addition of NaCl and with a constant addition of NaCl 0.003, 0.1 and 0.15 mol/l. Premicellar associations were not observed and in NaCl-free solutions CMC 0.0028 mol/l was spectrophotometrically determined. An addition of NaCl resulted in an increased hyperchromic effect and strengthening of micellization, manifested by a more than ten-times decrease in the CMC as well as the concentration of free benzethonium cations in micellar solutions. The courses of the determined concentrations of free benzethonium cations in the solutions both without and with the presence of NaCl were quite similar; their maximal values were always just a little higher than the corresponding CMC and with a further growth of the total concentration of benzethonium chloride there was, on the other hand, a marked decrease in the concentration of its free cations in micellar solution. Possible effects of a decreased concentration of free benzethonium cations due to an added electrolyte on antimicrobial activity and formation of ionic pairs are discussed.

Anti-Infective Agents↗
PubMed1990

[The effect of zinc chloride mouthwashes on caries-inducing plaque streptococci. 2. In vivo studies of the antibacterial effect of zinc chloride on the total streptococcal flora of the dental plaque].

During a 14-day test period a 0.2% and a 0.4% zinc chloride solution have been examined concerning their antibacterial efficiency on the total streptococcus flora of dental plaque under conditions conforming to standard by means of the Mylar foil technique. The results of the microbiological examination show a significant decrease of colony developing units of the plaque streptococci by a 7-day mouth rinsing with zinc chloride solution. The lesser antimicrobial effect of the zinc chloride solution compared with a 0.2% chlorhexidine solution is not proved statistically in the test period. A 0.2% or 0.4% zinc chloride solution could complete the mechanical dental and oral hygiene in an effective way.

Child↗
PubMed1988

HPLC analysis of polyamines and their acetylated derivatives in the picomole range using benzoyl chloride and 3,5-dinitrobenzoyl chloride as derivatizing agent.

Analytical methods are described for the quantitative determination of putrescine, cadaverine, spermidine, spermine and the acetylated derivatives of spermidine and spermine in biological fluids using pre-column derivatization with either benzoyl chloride or 3,5-dinitrobenzoyl chloride, which were added to each sample as solutions in diethyl ether. Putrescine, spermidine and spermine can be analysed in seminal plasma at nanogram levels when benzoyl chloride is used as derivatizing agent. In the analysis of putrescine, cadaverine, spermidine and acetyl derivatives of spermidine and spermine, higher sensitivity is obtained with 3,5-dinitrobenzoyl-chloride. This method can readily be used in the determination of acetylated polyamines in urine samples.

Acetylation↗
PubMed1983

Mutagenicity of dichloroacetylene and its degradation products trichloroacetyl chloride, trichloroacryloyl chloride and hexachlorobutadiene.

Dichloroacetylene (DCA) is a highly reactive compound that decomposes rapidly in contact with air into a series of chlorinated aliphatic hydrocarbons (e.g., phosgene, trichloroacetyl chloride, trichloroacryloyl chloride and hexachlorobutadiene). Experiments were performed to compare the mutagenic properties of DCA and its degradation products on the histidine-dependent tester strains TA98 and TA100 of Salmonella typhimurium. In these experiments, DCA vapour was streamed under analytical control through the bacterial suspensions. DCA is soluble in aqueous solution and was stable under the experimental steady-state conditions of the bacterial exposure. There is a linear correlation between the supply of DCA vapour and solubilized DCA in the range of 1000 and 16 000 ppm. Mutagenic response was observed with strain TA100 if the bacteria were suspended in Oxoid medium. No mutagenicity could be detected with strain TA98. DCA mixtures with acetylene, as used as stabilizer for animal experiments, were not mutagenic in either bacterial strain, irrespective of the presence or absence of S9 mix in the cell suspension. One of the degradation products of DCA, trichloroacryloyl chloride, showed pronounced mutagenic properties with and without drug-metabolizing enzymes. Other degradation products of DCA, such as trichloroacetyl chloride and hexachlorobutadiene, were not mutagenic, either in the presence or absence of liver homogenate.

Acetylene↗
PubMed2005

Mechanisms of solvolyses of acid chlorides and chloroformates. Chloroacetyl and phenylacetyl chloride as similarity models.

[reaction: see text] Rate constants and product selectivities (S = ([ester product]/[acid product]) x ([water]/[alcohol solvent]) are reported for solvolyses of chloroacetyl chloride (3) at -10 degrees C and phenylacetyl chloride (4) at 0 degrees C in ethanol/ and methanol/water mixtures. Additional kinetic data are reported for solvolyses in acetone/water, 2,2,2-trifluoroethanol(TFE)/water, and TFE/ethanol mixtures. Selectivities and solvent effects for 3, including the kinetic solvent isotope effect (KSIE) of 2.18 for methanol, are similar to those for solvolyses of p-nitrobenzoyl chloride (1, Z = NO(2)); rate constants in acetone/water are consistent with a third-order mechanism, and rates and products in ethanol/ and methanol/water mixtures can be explained quantitatively by competing third-order mechanisms in which one molecule of solvent (alcohol or water) acts as a nucleophile and another acts as a general base (an addition/elimination reaction channel). Selectivities increase for 3 as water is added to alcohol. Solvent effects on rate constants for solvolyses of 3 are very similar to those of methyl chloroformate, but acetyl chloride shows a lower KSIE, and a higher sensitivity to solvent-ionizing power, explained by a change to an S(N)2/S(N)1 (ionization) reaction channel. Solvolyses of 4 undergo a change from the addition/elimination channel in ethanol to the ionization channel in aqueous ethanol (<80% v/v alcohol). The reasons for change in reaction channels are discussed in terms of the gas-phase stabilities of acylium ions, calculated using Gaussian 03 (HF/6-31G(d), B3LYP/6-31G(d), and B3LYP/6-311G(d,p) MO theory).

Journal Article↗
PubMed1984

The effect of guanidinium chloride on the behaviour of human cervical-mucus glycoproteins. Evidence for unfolding regions of ordered structure in 6M-guanidinium chloride.

The macromolecular properties of cervical-mucus glycoproteins (mucins) were studied as a function of the concentration of guanidinium chloride with conventional light-scattering, photon-correlation spectroscopy and sedimentation-velocity centrifugation. No evidence for an association of the mucins in 0.2M-NaCl as compared with 6M-guanidinium chloride was found at mucin concentrations below approx. 0.5 mg/ml. However, an increase in the frictional coefficient and in the radius of gyration occurred with increasing concentrations of guanidinium chloride, in particular between 4 M and 6 M, suggesting an expansion of the individual macromolecule. The change in the particle-scattering function is consistent with a transition from a 'stiff' random coil in 0.2 M-NaCl into a more flexible one in 6 M-guanidinium chloride. We suggest that the mucins contain regions of 'ordered' structure which can undergo a reversible 'unfolding' analogous to the behaviour of a conventional globular protein exposed to a denaturing solvent. Such regions might carry sites for specific interactions between mucins and/or be decisive for their conformation and macromolecular properties in physiological solvents.

Cervix Mucus↗
PubMed1997

A study of the behaviour of cobalt chloride during the labelling of leukocytes with 99Tcm-HMPAO stabilised in vitro by the addition of cobalt chloride solution.

The method described by Weisner et al. for stabilizing 99Tcm-hexamethylpropylene amine oxime (99Tcm-HMPAO) with cobalt chloride hexahydrate solution is the most promising developed to date. The aim of our work was to study the behaviour of cobalt during the labelling of leukocytes with 99Tcm-HMPAO stabilized in vitro using this method. Three parallel labellings were carried out using six blood samples taken from polycythaemic patients. The first set of labellings was performed using 99Tcm-HMPAO, the second set using 99Tcm-HMPAO stabilized with cobalt chloride hexahydrate solution "spiked' with 57Co-chloride, and the third set using 57Co-chloride solution alone. Measurements of radioactivity content were made on the leukocyte pellets after washing at five time points post-labelling (t = 0, 30 min, 1 h, 2 h and 4 h). The data show that leukocytes do not retain cobalt during labelling with stabilized 99Tcm-HMPAO. Studies carried out in parallel demonstrated that the presence of cobalt in the cell-labelling medium had no effect on cell viability.

Analysis of Variance↗