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Results for “Chloride Ion Level”

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At least 19 recordsLinked to original sources
PubMed2002

Optical chloride sensor based on dimer-monomer equilibrium of indium(III) octaethylporphyrin in polymeric film.

A novel transduction chemistry for preparing optical anion-selective polymeric films that respond reversibly and selectively to chloride ion activity is demonstrated. The chloride sensors are prepared by casting thin (5-10 microm) plasticized PVC films containing indium(III) octaethylporphyrin hydroxide, along with optimized levels of a lipophilic tetraphenylborate salt, onto glass slides. When bathed in low-pH buffered solutions void of chloride, the porphyrin species spontaneously forms a hydroxide ion-bridged dimer, with the added lipophilic borate species serving as the counteranion for this complex. The maximum for the Soret absorption band of this dimeric species is shifted to 390 nm, from 410 nm for the initial monomeric porphyrin. Increases in chloride ion levels in the bathing solution results in chloride extraction and ligation to the In(III) center, and concomitant breaking of the dimer into monomeric porphyrin species, yielding a decrease in absorbance at 390 nm and an increase in optical signal at 410 nm. Under optimized conditions, optical selectivity coefficients toward chloride over a wide range of other anions (NO3-, ClO4-, SCN-, SO4(2-), F-, Br-, H2PO4-) are measured to be < 10(-3). Of all anions tested, only salicylate yields a slightly greater response than chloride. This selectivity is shown to be adequate for reversible and accurate sensing of chloride levels in diluted serum samples.

Animals↗
PubMed1995

Chloride effect on the early photolysis intermediates of a gecko cone-type visual pigment.

Nanosecond laser photolysis measurements were conducted on the cone-type visual pigment P521 in digitonin extracts of Tokay gecko (Gekko gekko) retina containing physiological chloride ion levels and also on samples which had been chloride depleted or which contained high levels (4 M) of chloride. Absorbance difference spectra were recorded at a sequence of time delays from 30 ns to 60 microseconds following excitation with a pulse of either 532- or 477-nm actinic light. Global analysis showed the kinetic decay data for gecko pigment P521 to be best fit by two exponential processes under all chloride conditions. The initial photoproduct detected had a broad spectrum characteristic of an equilibrated mixture of a Batho P521 intermediate with its blue-shifted intermediate (BSI P521) decay product. The first exponential process was assigned to the decay of this mixture to the Lumi P521 intermediate. The second exponential process was identified as the decay of Lumi P521 to Meta I P521. The initial photoproduct's spectrum exhibited a strong dependence on chloride concentration, indicating that chloride affects the composition of the equilibrated mixture of Batho P521 and BSI P521. These results suggest that the affinity for chloride is reduced approximately 5-fold in the Batho P521 intermediate and approximately 50-fold in the BSI P521 intermediate. Chloride concentration also affects the apparent decay rate of the equilibrated mixture. When the apparent decay rate is corrected for the composition of the equilibrated mixture, a relatively invariant microscopic rate constant is obtained for BSI decay (k = 1/55 ns-1).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

[Effects of hyperosmolarity and furosemide on resting membrane potentials and skeletal muscle fiber volume in rats].

The changes of the muscle fibres volume and resting membrane potential (RMP) were studied following treatment with hypertonic medium and furosemide. The volume changes in hypertonic medium began with cell shrinkage and later have been followed by the volume increase up to normal level during 30-40 minutes. At the same time the medium hypertonicity caused muscle fibres depolarisation. The hypertonic-induced decrease of the RMP was delayed in the furosemide-treated muscle. Besides, furosemide abolished the muscle fibres volume restorative properties in hypertonic medium. It is suggested that the membrane depolarisation and cell volume restoration in hypertonic medium are the resultant effects of intracellular chloride ions level elevation which, in turn, have been evoked by activation of furosemide-sensitive Cl(-)-influx system.

Animals↗
PubMed1999

Hypochlorite Ion Decomposition: Effects of Temperature, Ionic Strength, and Chloride Ion.

The effects of pH, hypochlorite and chloride ion concentration, temperature, and ionic strength on the kinetics and mechanism of decomposition of concentrated hypochlorite ion and the formation of chlorate ion and oxygen in the pH 9-14 region has been investigated. In the absence of catalytic levels of transition-metal ions, the rate of chlorate ion formation is 8.7 times faster than the rate of oxygen formation for the concentration range of 0.7-3.0 M hypochlorite ion with various levels of chloride ion in 0.001-1.0 M OH(-) at 15-55 degrees C. Under these same conditions, the equation that describes the effect of temperature and ionic strength on the decomposition of OCl(-) is the following: log k(2) = 0.149&mgr; + log[2.083 x 10(10)T exp(-1.018 x 10(5)/RT) exp(-56.5/R)] where k(2) has units of M(-)(1) sec(-)(1) and &mgr; is between 1 and 6 molar. Numerical simulation of the decomposition of OCl(-) was carried out while taking into account the effect of each of the above experimental variables. Evidence is presented suggesting chloride ion catalyzed decomposition of hypochlorite ion in the pH 9-10 region that is in addition to the contribution of chloride ion to the ionic strength.

Journal Article↗
PubMed2002

CFTR gene mutations in patients suffering from acute pancreatitis.

BACKGROUND: The aim of our study was to investigate the frequency of the CFTR gene mutation in a selected group of patients suffering from severe acute pancreatitis. MATERIAL/METHODS: DNA isolated from peripheral blood samples from forty-one subjects was analyzed for the eight most common CFTR gene mutations (deltaF508, G542X, G551D, R553X, 1717-1(G>A), W1282X, N1303K, deltaI507) by the reverse-hybridization technique, using INNO-LIPA CF2 test strips. The level of chloride ions in sweat samples was established using the pilocarpine iontophoresis method. RESULTS: In the study group, none of the patients harbored CFTR gene mutations. In these selected cases, the experiments were repeated twice to ensure the reliability of the results. All of the subjects had a normal level of chloride ions (range 8-38 mmol/l). Comparison with historical carriers revealed no differences between the frequency of carriers of the CFTR gene mutations in the general Polish population (4%) in comparison with the surgical patients with acute pancreatitis (p=0.26; Fisher exact test). CONCLUSIONS: We found no patients with severe acute pancreatitis who had CFTR gene mutations, suggesting that these alterations are not a risk factor for the disease in our population. Further studies are warranted to evaluate the frequency and role of rare ('mild') CFTR gene point mutations in subjects suffering from severe acute pancreatitis.

Adult↗
PubMed2004

Determination of anion-exchange resin performance based on facile chloride-ion monitoring by FIA-spectrophotometry with applications to water treatment operation.

Based on a flow-injection spectrophotometry, an automatic analytical method for determination of ppb-level chloride-ion has been established. By use of this method, a novel FIA method for the determination of SBAER performance has also been developed. In this paper, the effects of concentration, dosage, and flow rate of the regenerant on BEC of SBAER were first investigated dynamically by the FIA method. In addition, the flow rate of the sample water and the temperature of the ion exchange resin were also examined. The optimum conditions were obtained: the volume of the regenerant (sodium hydroxide) was 50 mL (0.15 g resin), and its concentration was 3% (w/v); the volumetric flow rates of the regenerant and the sample water were 0.5 ml/min (4.3 m/h) and 1.5 ml/min (13 m/h), respectively. The exchanging temperature was 25 +/- 5 degrees C. The method is characterized by the use of a micro resin-column, shorter testing cycle, easy operation, and high reproducibility. The proposed method is approximately 30 times more efficient than the manual method, and it can be used for the exchange performance comparison of various SBAER.

Journal Article↗
PubMed1987

Urinary excretion of N-nitrosamino acids and nitrate by inhabitants in high- and low-risk areas for stomach cancer in northern Japan.

Three samples of 24-h urine were collected from each of 104 inhabitants of high-risk (Akita) and low-risk (Iwate) areas for stomach cancer in northern Japan, according to the following protocols: (i) when they were undosed, (ii) after ingestion of proline three times a day and (iii) after ingestion of proline together with vitamin C three times a day. These samples were analysed for N-nitrosamino acids, nitrate and chloride ion as indices of the exposure. The median values of N-nitrosoproline (NPRO) and N-nitroso-2-methylthiazolidine 4-carboxylic acid (NMTCA) excreted in the urine of undosed subjects were not different between the two areas; however, that of N-nitrosothiazolidine 4-carboxylic acid (NTCA) was significantly higher in subjects of the high-risk area. Salt intake, estimated from the level of chloride ion in the urine, did not differ in two areas. After intake of proline, the NPRO level increased significantly only in subjects of the high-risk area, but not in those of the low-risk area; intake of vitamin C inhibited this increase of NPRO and lowered the levels of other nitrosamino acids only in the high-risk subjects. In contrast, the urinary level of nitrate was higher in subjects of the low-risk area than in those of the high-risk area; nitrate levels were found to correlate well with the amounts of vegetables consumed.(ABSTRACT TRUNCATED AT 250 WORDS)

Ascorbic Acid↗
PubMed2003

Role of the two type II myosins, Myo2 and Myp2, in cytokinetic actomyosin ring formation and function in fission yeast.

The formation and contraction of a cytokinetic actomyosin ring (CAR) is essential for the execution of cytokinesis in fission yeast. Unlike most organisms in which its composition has been investigated, the fission yeast CAR contains two type II myosins encoded by the genes myo2(+) and myp2(+). myo2(+) is an essential gene whilst myp2(+) is dispensable under normal growth conditions. Myo2 is hence the major contractile protein of the CAR whilst Myp2 plays a more subtle and, as yet, incompletely documented role. Using a fission yeast strain in which the chromosomal copy of the myo2(+) gene is fused to the gene encoding green fluorescent protein (GFP), we analysed CAR formation and function in the presence and absence of Myp2. No change in the rate of CAR contraction was observed when Myp2 was absent although the CAR persisted longer in the contracted state and was occasionally observed to split into two discrete rings. This was also observed in myp2Delta cells following actin depolymerisation with latrunculin. CAR contraction in the absence of Myp2 was completely abolished in the presence of elevated levels of chloride ions. Thus, Myp2 appears to contribute to the stability of the CAR, in particular at a late stage of CAR contraction, and to be a component of the signalling pathway that regulates cytokinesis in response to elevated levels of chloride. To determine whether the presence of two type II myosins was a feature of cytokinesis in other fungi that divide by septation, we searched the genomes of two filamentous fungi, Aspergillus fumigatus and Neurospora crassa, for myosin genes. As in fission yeast, both A. fumigatus and N. crassa contained myosins of classes I, II, and V. Unlike fission yeast, both contained a single type II myosin gene that, on the basis of its tail structure, was more reminiscent of Myp2 than Myo2. The significance of these observations to our understanding of septum to formation and cleavage is discussed.

Actomyosin↗
PubMedDate not supplied

Halide-catalyzed cis product formation in the hydrolysis of anti-benzo[a]pyrene diol epoxide and its alkylation of poly(A).

The carcinogen 7-r,8-t-dihydroxy-9-t,10-t-epoxy-7,8,9,10- tetrahydrobenzo[a]pyrene (anti-BPDE) forms diastereomeric cis and trans products in its reactions with nucleic acids and water (adducts and tetrols, respectively). The effects of salts, buffers, and DNA on the hydrolysis product ratio were tested. Halide ions increase the cis-tetrol/trans-tetrol ratio, with the order of effectiveness being I > Br > Cl >> F. No cation effect was apparent. Non-halide salts of strong acids increase the ratio to a small degree. Buffers decrease the ratio, with phosphate being more effective than cacodylate. DNA also reduces the ratio, with denatured DNA being more potent than native DNA. Halide ions appear to catalyze cis-tetrol formation via trans halohydrin intermediates. At the lowest halide concentrations which significantly raise the product ratio, and at all levels of chloride ion, the rate of anti-BPDE hydrolysis is not greatly increased, indicating that the halide ions are reacting primarily with the BPDE carbocation formed in the rate-determining step. At higher concentrations, iodide ion and, to a lesser degree, bromide ion significantly accelerate hydrolysis, indicating that BPDE undergoes SN2 attack by these ions. Chloride ion was also found to increase the proportion of cis adducts formed between anti-BPDE and poly(A). The cis adduct/trans adduct ratio was quadrupled by 0.5 M NaCl. This suggests that chlorohydrins can be intermediates in the alkylation of nucleic acids by epoxides of polycyclic aromatic hydrocarbons.

7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide↗
PubMed1996

Characterization of ion interference in gossypol consumption.

The goal of the present investigation was to show that gossypol has the potential of ion interference capable of affecting the metabolic activation of the biologic system. Gossypol was administered orally at 20 mg/kg body weight (bw) for 8 weeks and the animals were fed a controlled diet. At the end of the experiment, liver supernatant was subjected to atomic absorption spectrometry. The characteristic ion interferences were examined for calcium, ferrous, sodium, magnesium, potassium and chloride ions. Glutathione level and lactate dehydrogenase activity were also monitored. The peak heights for calcium and ferrous ions were high and low respectively but the ion ratio for calcium is suggestive of a ligand-like substance that may be cumulative, thereby leading to biologic magnification (toxicity).

Animals↗
PubMed2002

Solubility of E2050 at various pH: a case in which apparent solubility is affected by the amount of excess solid.

The solubility of E2050, supplied as a dihydrochloride salt, in aqueous solutions at different pHs was studied. Two pK(a)s controlling the equilibrium between the various protonated species were determined. The solubility-pH profile of E2050 is expected to be high in acidic solutions because protonated species are formed and to be low in alkaline conditions due to the formation of hydrophobic free base. The solubility is also affected by chloride ion, a common ion for this drug substance. Two solubility products (K(sp)) were determined corresponding to the solubility of di-HCl salt and mono-HCl salt. Based on the pK(a)s (3.10 and 7.71), the solubility products with chloride (2.92 and 3.77 as corresponding pK(sp)), and the solubility of free base (2 x 10(-5) M), the solubility in solutions with different pH and different levels of chloride ion can be predicted. The prediction of the solubility change during the dilution of E2050 parenteral formulations by saline was also demonstrated. Furthermore, the present study presents an interesting example in which an apparent solubility can be different if varying (excess) amounts of salt are added to the solution. In this case, excess chloride ion suppresses the solubility in the pH region where mono-HCl salt controls the solubility.

Chemical Phenomena↗
PubMed2003

Spatio-temporal activation of caspase revealed by indicator that is insensitive to environmental effects.

Indicator molecules for caspase-3 activation have been reported that use fluorescence resonance energy transfer (FRET) between an enhanced cyan fluorescent protein (the donor) and enhanced yellow fluorescent protein (EYFP; the acceptor). Because EYFP is highly sensitive to proton (H+) and chloride ion (Cl-) levels, which can change during apoptosis, this indicator's ability to trace the precise dynamics of caspase activation is limited, especially in vivo. Here, we generated an H+- and Cl--insensitive indicator for caspase activation, SCAT, in which EYFP was replaced with Venus, and monitored the spatio-temporal activation of caspases in living cells. Caspase-3 activation was initiated first in the cytosol and then in the nucleus, and rapidly reached maximum activation in 10 min or less. Furthermore, the nuclear activation of caspase-3 preceded the nuclear apoptotic morphological changes. In contrast, the completion of caspase-9 activation took much longer and its activation was attenuated in the nucleus. However, the time between the initiation of caspase-9 activation and the morphological changes was quite similar to that seen for caspase-3, indicating the activation of both caspases occurred essentially simultaneously during the initiation of apoptosis.

Apoptosis↗
PubMed2002

Immunotoxic effects of 2-bromopropane in male Sprague-Dawley rats: a 28-day exposure study.

Immunotoxic effects of 2-bromopropane were investigated in male Sprague-Dawley rats. The rats were treated orally daily with 2-bromopropane at 100, 330, or 1000 mg/kg for 28 consecutive days. Four days before necropsy, the rats were immunized intravenously with sheep red blood cells (SRBCs). The body and thymus weights were significantly reduced by treatment with 2-bromopropane at the highest dose. In addition, the numbers of splenic and thymic cells were decreased by 2-bromopropane. In hematology, the numbers of white blood cells, red blood cells, and platelets were significantly reduced. Among the serum clinical parameters, the levels of chloride ion were significantly increased by 2-bromopropane. The antibody response to SRBCs was significantly suppressed at the highest dose. With immunized animals, immunophenotyping of splenic and thymic cells was performed to investigate the changes of the number of macrophages, B cells, and T cells in spleen and the number of CD4+ and CD8+ cells in thymus. The numbers of most cell types were significantly decreased in the spleen when animals were treated with 2-bromopropane at 1,000 mg/kg. Likewise, all cell types of thymus were significantly decreased by 2-bromopropane. The present results suggest that 2-bromopropane may have an immunotoxic potential in male Sprague-Dawley rats when the rats are exposed for 28 d.

Administration, Oral↗
PubMed1970

Mechanism of bicarbonate absorption and its relationship to sodium transport in the human jejunum.

Using a constant perfusion technique, sodium and bicarbonate absorption was studied in human subjects. The following observations were made on sodium absorption from saline solution: (a) the rate of sodium absorption is markedly influenced by bulk water flow, (b) when net water flow is zero, sodium absorption is zero if there are no concentration gradients between plasma and lumen that favor net NaCl diffusion; and (c) the PD between abraded skin and jejunal lumen is near zero when saline is perfused and does not change with partial substitution of sulfate or bicarbonate for chloride. Based on these observations, we conclude that sodium absorption from saline is entirely passive in the human jejunum. On the other hand, in the presence of bicarbonate sodium is absorbed actively against electrochemical gradients. The mechanism of the link between bicarbonate and sodium absorption was studied in normal subjects and in 11 patients with pernicious anemia; the latter were chosen because they do not secrete gastric acid which can react with bicarbonate in the jejunal lumen. We observed that bicarbonate absorption (a) occurs against steep electrochemical gradients, (b) does not generate a potential difference between abraded skin and jejunal lumen, (c) is inhibited by acetazolamide, and (d) generates a high CO2 tension in jejunal fluid. These observations suggest that bicarbonate absorption is mediated by active hydrogen secretion, rather than by bicarbonate ion transport per se, and that the link between sodium and bicarbonate transport is best explained by a sodium-hydrogen exchange process.

Acetazolamide↗