PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “POTASSIUM CHLORIDE”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 883 records · Page 49Linked to original sources

Interaction of woodchuck hepatitis virus surface antigen with hepatocyte plasma membrane in woodchuck chronic hepatitis.

The extent of association between woodchuck hepatitis virus surface antigen and host hepatocyte plasma membrane in chronic hepatitis was studied. Purified membranes containing the antigen were treated with various agents which perturb plasma membrane constituents to elute woodchuck hepatitis virus surface antigen. The products from disrupted membranes were analyzed by sedimentation in sucrose gradients and tested to identify the antigen reactivity. The results indicated that membrane-bound woodchuck hepatitis virus surface antigen was partially released by 4 M potassium chloride, potassium thiocyanate and guanidine, 6 M urea or 0.1 N sodium hydroxide (pH 13.5), but not in the presence of low concentrations of these reagents or by 10% 2-mercaptoethanol and 1% sodium dodecyl sulfate. No more than 15% of the total membrane-associated woodchuck hepatitis virus surface antigen was eluted by 0.1 N NaOH, which was found to be the most effective eluent among tested agents at the antigen removal. The remaining woodchuck hepatitis virus surface antigen was resistant to further extraction with sodium hydroxide, as expected for an integral membrane protein. Treatment of the infected membranes with 1% Triton X-100 or 50 mM deoxycholic acid, that solubilize the membrane lipid bilayer releasing most of the integral membrane proteins, resulted in the sedimentation of almost all detectable woodchuck hepatitis virus surface antigen reactivity with the detergent-insoluble membrane residues, suggesting a firm interaction of the antigen with the plasma membrane matrix.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Electrical conductance of directly compressible materials under pressure.

An electrometer that allowed direct recording of resistance changes during compression was used to measure the conductances of sodium chloride, potassium chloride, ammonium chloride, and sodium citrate. The effects of initial particle size, lubricant level, moisture content, and compaction pressure were determined. Direct compression tableting diluents also studied were dextrose, sucrose, lactose, microcrystalline cellulose, and dibasic calcium phosphate. Distinctive conductance patterns were observed and are rationalized in terms of previously proposed bondign machanisms.

Electric Conductivity↗

Determination of isopropylmethylphenols in black seed oil by differential pulse voltammetry.

A differential pulse voltammetric method is presented for the determination of isopropylmethylphenols (carvacrol and/or thymol) in phytotherapeutic black seed oils. The voltammetric behaviours of these phenols were examined in various buffer systems over the pH range 3.5-10.0. In Sörensen buffered methanol solution (3:7; v:v; pH 8.5), the differential pulse voltammograms exhibited reproducible peaks at Ep + 0.49 V vs. silver-silver chloride-potassium chloride 3 M for both carvacrol and thymol. Under these conditions, a plot of peak height against concentration of the isopropylmethylphenols was found to be linear over the range 0.25-2.5 microg/mL (r = 0.999). The detection limit was 0.04 microg/mL. The described voltammetric method was tested on two black seed oils available on the Austrian market.

Cymenes↗

Kinetic and crystallographic studies of Escherichia coli UDP-N-acetylmuramate:L-alanine ligase.

Uridine diphosphate-N-acetylmuramate:L-alanine ligase (EC 6.3.2.8, UNAM:L-Ala ligase or MurC gene product) catalyzes the ATP-dependent ligation of the first amino acid to the sugar moiety of the peptidoglycan precursor. This is an essential step in cell wall biosynthesis for both gram-positive and gram-negative bacteria. Optimal assay conditions for initial velocity studies have been established. Steady-state assays were carried out to determine the effect of various parameters on enzyme activity. Factors studies included: cation specificity, ionic strength, buffer composition and pH. At 37 degrees C and pH 8.0, kcat was equal to 980 +/- 40 min-1, while K(m) values for ATP, UNAM, and L-alanine were, 130 +/- 10, 44 +/- 3, and 48 +/- 6 microM, respectively. Of the metals tested only Mn, Mg, and Co were able to support activity. Sodium chloride, potassium chloride, ammonium chloride, and ammonium sulfate had no effect on activity up to 75 mM levels. The enzyme, in appropriate buffer, was stable enough to be assayed over the pH range of 5.6 to 10.1. pH profiles of Vmax/K(m) for the three substrates and of Vmax were obtained. Crystallization experiments with the enzyme produced two crystal forms. One of these has been characterized by X-ray diffraction as monoclinic, space group C2, with cell dimensions a = 189.6, b = 92.1, c = 75.2 A, beta = 105 degrees, and two 54 kDa molecules per asymmetric unit. It was discovered that the enzyme will hydrolyze ATP in the absence of L-alanine. This L-alanine independent activity is dependent upon the concentrations of both ATP and UNAM; kcat for this activity is less than 4% of the biosynthetic activity measured in the presence of saturating levels of L-alanine. Numerous L-alanine analogs tested were shown to stimulate ATP hydrolysis. A number of these L-alanine analogs produced novel products as accessed by HPLC and mass spectral analysis. All of the L-alanine analogs tested as inhibitors were competitive versus L-alanine.

Crystallization↗

Adventitious redox-active metals in Krebs-Henseleit buffer can contribute to Langendorff heart experimental results.

Adventitious redox-active metals in Krebs-Henseleit buffer exhibit a significant enhancement of damage to isolated rat hearts. Using atomic absorption spectroscopy, it was determined that Krebs-Henseleit buffer contains substantial amounts of contaminating iron and copper. Significant copper contamination was found in ACS Reagent grade sodium chloride and sodium bicarbonate; iron contamination in sodium chloride, potassium chloride, sodium bicarbonate, and calcium chloride. Chelating resin treatment of individual reagents was found to decrease copper content of Krebs-Henseleit buffer from 0.32 to 0.17 microM. Using salicylate as a probe for .OH formation, it was determined that considerable amounts of this radical are formed when 0.25 mM ascorbate is added to the buffer indicating significant metal-catalysed autoxidation. Isolated rat hearts, perfused with non-chelexed Krebs-Henseleit buffer plus 0.25 mM ascorbate for 60 min, sustained moderate injury with developed systolic pressure, +dP/dtmax and -dP/dtmax decreased by 30 to 35% by the end of experiment. Hearts perfused with chelating resin-treated Krebs-Henseleit buffer sustained no significant injury within the same time frame. Furthermore, it was observed that hearts perfused with non-chelexed Krebs-Henseleit buffer accumulate significant amounts of copper depending on the amount of contamination and length of perfusion. Significant effects on post-ischemic end diastolic pressure were observed in hearts perfused with a Krebs-Henseleit buffer subsequently found to be contaminated with high levels of copper. These results clearly demonstrate that adventitious redox-active transition metals may be a confounding factor in experimental results. Further, it is recommended that all perfusion media be routinely examined for adventitious metals and treated if deemed necessary.

Animals↗

Food additives and plant components control growth and aflatoxin production by toxigenic aspergilli: a review.

Growth and aflatoxin production by toxigenic aspergilli are partially or completely inhibited by the undissociated form of acetic, benzoic, citric, lactic, propionic and sorbic acids. Salts such as sodium chloride, potassium chloride and sodium nitrate, at low concentrations, can enhance aflatoxin production. At higher concentrations they become inhibitory, but marked inhibition requires amounts of the salts greater than are commonly used in foods. Phenolic antioxidants, sometimes added to foods to prevent oxidative deterioration, also are inhibitory to toxigenic aspergilli. Other inhibitory agents include certain insecticides, methylxanthines (caffeine and theophyllin), and components of some herbs, spices and other plants.

Aflatoxins↗

Hydroxyhydroquinone reductase, the initial enzyme involved in the degradation of hydroxyhydroquinone (1,2,4-trihydroxybenzene) by Desulfovibrio inopinatus.

The recently isolated sulfate reducer Desulfovibrio inopinatus oxidizes hydroxyhydroquinone (1,2,4trihydroxybenzene; HHQ) to 2 mol acetate and 2 mol CO2 (mol substrate)-1, with stoichiometric reduction of sulfate to sulfide. None of the key enzymes of fermentative HHQ degradation, i.e. HHQ-1,2,3,5-tetrahydroxybenzene transhydroxylase or phloroglucinol reductase, were detected in cell-free extracts of D. inopinatus, indicating that this bacterium uses a different pathway for anaerobic HHQ degradation. HHQ was reduced with NADH in cell-free extracts to a nonaromatic compound, which was identified as dihydrohydroxyhydroquinone by its retention time in HPLC separation and by HPLC-mass spectrometry. The compound was identical with the product of chemical reduction of HHQ with sodium borohydride. Dihydrohydroxyhydroquinone was converted stoichiometrically to acetate and to an unknown coproduct. HHQ reduction was an enzymatic activity which was present in the cell-free extract at 0.25-0.30 U (mg protein)-1, with a pH optimum at 7.5. The enzyme was sensitive to sodium chloride, potassium chloride, EDTA, and o-phenanthroline, and exhibited little sensitivity towards sulfhydryl group reagents, such as copper chloride or p-chloromercuribenzoate.

Biodegradation, Environmental↗

Studies on some biological differences between the chiral forms of methyl-1-naphthyl-p-nitrophenyl phosphorothionate.

A general degranulation test for carcinogens using the postmitochondrial supernatant (PMS) was based on the consistency of the stripping of ribosomes from rough endoplasmic reticulum. The degranulation phenomenon has been classified into three types, which are D1A, D1B and D11. This classification which is new has been introduced to probe more into the mechanistic aspects of degranulation. Aflatoxin B1 dimethylnitrosamine, 2-acetylaminofluorene, and 4-dimethylaminobenzene were carcinogens, evaluated in the PMS system. Reduced glutathione (GSH), oxidized glutathione (GSSG), sodium chloride, potassium chloride, lithium chloride, lithium carbonate, and ascorbic acid which are noncarcinogens and the (+) and (-) chiral forms of methyl-1-naphthyl-p-nitrophenyl phosphorothionate were also evaluated in the PMS system. Lithium carbonate is teratogenic in rats. Similar findings have also been reported in mice, and lithium ion has been confirmed to be teratogenic in mice. This biological phenomenon of the D11 type could well evolve as a teratogenic effect and not a carcinogenic effect.

Aflatoxin B1↗

A biotin-containing compound N-(2-aminoethyl)biotinamide for intracellular labeling and neuronal tracing studies: comparison with biocytin.

The hydrochloride salt of a new, small molecular weight (M.W. = 286) biotin-containing compound referred to as biotinamide (N-(2-aminoethyl)biotinamide) was compared with biocytin (M.W. = 372) for its use in intracellular labeling of neurons and in neuronal tracing experiments using avidin conjugates for histochemical detection. The DC resistance and current passing ability of electrodes filled with 1-2 M potassium chloride, potassium acetate or potassium methylsulfate and containing 1-4% of these compounds were compared. Although differences were observed due to the electrolyte, with KCl electrodes being the least resistant, no electrode differences could be attributed to the concentration or type of tracer. However, whereas biocytin could be electrophoresed with either positive or negative current with roughly similar facility, biotinamide was selectively ejected with positive current. This would be beneficial to electrophysiologists using hyperpolarizing current to stabilize the membrane potential of neurons prior to recording. In addition, biotinamide-HCl could be dissolved at concentrations of 2-4% in either 1 or 2 M salt without precipitation, whereas biocytin precipitated in some of these solutions. Both compounds were equally useful for neuronal tracing experiments with survival times of 2 days, but labeling was much weaker with longer survival times. There was also little difference in the ability to histochemically localize these compounds using avidin conjugates, including avidin-biotin-horseradish peroxidase complex. In conclusion, biotinamide shares many of the useful features of biocytin, but can be selectively electrophoresed with positive current and can be dissolved at higher concentrations with little detriment in the electrical properties of the recording electrode.

Animals↗

Determination of iodide in seawater and edible salt by microcolumn liquid chromatography with poly(ethylene glycol) stationary phase.

An ion chromatography method for rapid and direct determination of iodide in seawater and edible salt is reported. Separation was achieved using a laboratory-made C30 packed column (100 mm x 0.32 mm i.d.) modified with poly(ethylene glycol) (PEG). Effects of eluent composition on retention behavior of inorganic anions have been investigated. Both cation and anion of the eluent affected the retention of analyte anions. The retention time of anions increased with increasing eluent concentration when lithium chloride, sodium chloride, potassium chloride, sodium sulfate, magnesium sulfate were used as the eluent, while it decreased with increasing eluent concentration when ammonium sulfate was used as the eluent. The detection limit for iodide obtained by injecting 0.2 microl of sample was 9 microg/l (S/N = 3). The present method was successfully applied to the rapid and direct determination of iodide in seawater and edible salt samples. Partition may be involved in the present separation mode.

Acetonitriles↗

Effect of stabilizers on the shelf-life of Penicillium frequentans conidia and their efficacy as a biological agent against peach brown rot.

Stabilizers were added to conidia of Penicillium frequentans at two different points of the production-formulation process to improve shelf-life of conidia stored at different temperatures. Effects were also tested on conidial germination and production. Germination of conidia without additives was 90.2%; sodium chloride, potassium chloride, triton TX100, dimethyl sulphoxide, peroxidase, 0.375% and 0.075% ascorbic acid, 7.5% and 3.75% sucrose, and 7.5% and 3.75% d-sorbitol reduced significantly (P=0.05) conidial germination, while no effect was observed with glucose, lactose, maltose, sodium glutamate, glycerol, peptone, sodium alginate, carboximethylcellulose, Tween 80, and gelatine. Production of P. frequentans conidia in solid-state fermentation without additives was 1.07 conidia x 10(8) g(-1) of dry substrate. The highest tested doses of glucose, lactose, maltose, sodium glutamate, and glycerol enhanced production of P. frequentans, while the lowest tested doses of d-sorbitol and ascorbic acid reduced it. No significant effect was observed with sucrose, peptone, sodium alginate, carboximethylcellulose, gelatine and Tween 80. Conidial germinability after one year of storage at different temperatures was studied in some formulations. It was lower than 18% after 365 days of storage at room temperature in control samples (without any additive), being enhanced when 7.5% glucose, 7.5% glycerol, or 1.5% sodium alginate was added to the substrate in bags before fermentation; or when 7.5% glucose, 7.5% sodium glutamate, or 1.5% sodium alginate was added to conidia before drying. Germinability of conidia produced without any additive and stored at 4 degrees C was significantly higher (38%) than at room temperature, being enhanced when 7.5% glycerol or 1.5% sodium alginate was added to the substrate in bags before fermentation; and when 7.5% glucose, or 1.5% sodium alginate was added to conidia before drying. No effect was observed with the presence or absence of light or high vacuum. Four formulations of P. frequentans conidia reduced disease incidence by more than 55%. The relationship of the disease control with the viability of P. frequentans was discussed.

Biological Factors↗

Evaluation of Alstonia scholaris leaves for broncho-vasodilatory activity.

The present study demonstrates that the ethanol extract of Alstonia scholaris (Apocynaceae) leaves induced pronounced bronchodilatory activity in anaesthetized rats with the probable involvement of prostaglandins. However, in vitro preparations of guinea-pig trachea did not confirm this property, indicating that bronchodilation is not due to the direct tracheal smooth muscle relaxation. The vasodilatory activity of the extract was independent of adrenergic or muscarinic receptors or prostaglandins but was mainly via endothelial-derived relaxing factor, nitric oxide. The extract inhibited the spontaneous movements of rabbit jejunum and contractile effects of acetylcholine and histamine on guinea-pig ileum. Additionally, the extract caused marked reduction of barium chloride-, potassium chloride- and calcium chloride-induced contraction on guinea-pig ileum and pulmonary artery, implying a direct interference of plant extract with the influx of calcium ions into cells. However, the extract has no detectable effect on mobilization of intracellular calcium. These results coupled with the in vivo effects of ethanol extract reveal that the Alstonia scholaris leaves possess broncho-vasodilatory activity mediated presumably by prostaglandins, calcium antagonism and endothelium-derived relaxing factor(s).

Alstonia↗

Effects of water potential on mycelial growth, sclerotial production, and germination of Rhizoctonia solani from potato.

The effects of osmotic and matric potential on mycelial growth, sclerotial production and germination of isolates of Rhizoctonia solani [anastomosis groups (AGs) 2-1 and 3] from potato were studied on potato dextrose agar (PDA) adjusted osmotically with sodium chloride, potassium chloride, glycerol, and matrically with polyethylene glycol (PEG) 6000. All isolates from AGs 2-1 and AG-3 exhibited fastest mycelial growth on unamended PDA (-0.4MPa), and growth generally declined with decreasing osmotic and matric potentials. Growth ceased between -3.5 and -4.0MPa on osmotically adjusted media, and at -2.0MPa on matrically adjusted media, with slight differences between isolates and osmotica. Sclerotium yield declined with decreasing osmotic potential, and formation by AG 2-1 and AG-3 isolates ceased between -1.5 and -3.0MPa and -2.5 and -3.5MPa, respectively. On matrically adjusted media, sclerotial formation by AG 2-1 isolates ceased at -0.8MPa, whereas formation by AG-3 isolates ceased at the lower matric potential of -1.5MPa. Sclerotial germination also declined with decreasing osmotic and matric potential, with total inhibition occurring over the range -3.0 to -4.0MPa on osmotically adjusted media, and at -2.0MPa on matrically adjusted media. In soil, mycelial growth and sclerotial germination of AG-3 isolates declined with decreasing total water potential, with a minimum potential of -6.3MPa permitting both growth and germination. The relevance of these results to the behaviour of R. solani AGs in soil and their pathogenicity on potato is discussed.

Agar↗

Time dependent changes in diabetic cystopathy in rats include compensated and decompensated bladder function.

PURPOSE: Diabetic bladder dysfunction is among the most common and bothersome complications of diabetes mellitus. While bladder filling and voiding problems have been reported, the precise functional changes in diabetic bladders remain unclear. We investigated time dependent changes in bladder function in streptozotocin induced diabetic rats. MATERIALS AND METHODS: Cystometrograms and detrusor muscle contractility were examined in male age matched control and diabetic Sprague-Dawley rats (Harlan, Indianapolis, Indiana) 3, 6, 9, 12 and 20 weeks after diabetes induction with streptozotocin. RESULTS: Diabetes decreased average body weight and increased bladder weight, capacity and compliance. Peak detrusor leak pressure increased gradually from weeks 3 to 6 to 9 in diabetic rats (mean +/- SEM 47.3 +/- 2.5, 50.8 +/- 3.0 and 56.0 +/- 3.6 cm H(2)O) and in controls (36.9 +/- 1.4, 37.7 +/- 1.5 and 41.6 +/- 1.81 cm H(2)O, respectively). However, at 12 and 20 weeks diabetic rats deviated strongly from this trend with peak detrusor leak pressure decreasing vs controls (41.6 +/- 2.8 and 37.3 +/- 0.9 vs 45.2 +/- 1.7 and 49.6 +/- 1.4 cm H(2)O, respectively) and post-void resting pressures increasing from 9-week levels vs controls (interactions p <0.0001). In contractility studies increased contractile force responses of diabetic animals to carbamylcholine chloride, potassium chloride, adenosine 5'-triphosphate and electric field stimulation peaked at 6 or 9 weeks but at 12 to 20 weeks they generally reverted toward those of controls (carbamylcholine chloride and electrical field stimulation interactions p = 0.0022 and 0.01, respectively). CONCLUSIONS: Diabetic bladders may undergo a transition from a compensated to a decompensated state and transition in the streptozotocin rat model may begin 9 to 12 weeks after induction.

Animals↗

Broncho-vasodilatory activity of fractions and pure constituents isolated from Bacopa monniera.

The present study demonstrates that various fractions and sub-fractions isolated from Bacopa monniera produced significant inhibition of carbachol-induced bronchoconstriction, hypotension and bradycardia in anaesthetized rats. All these showed more potency towards inhibition of tracheal pressure compared to either blood pressure or heart rate. The sub-sub fraction and compound 1 caused greater inhibition of tracheal pressure and heart rate compared to blood pressure. Thus, overall bioassay-directed fractionation of B. monniera improved the bronchodilatory activity in various fractions and compound 1 (2-219x) in anaesthetized rats. In vitro, the KCl-induced contraction was equally inhibited by crude extract, petroleum ether and methanol fractions on trachea suggesting bronchodilatory activity remained the same in fractions. On pulmonary artery petroleum ether, dichloromethane and methanol fractions produced 2-2.6 times more vasodilatation compared to crude extract of B. monniera. Subsequent sub-fractions failed to show the existence of broncho-vasodilatory activity, however, the CHCl(3)/MeOH sub-fraction significantly reduced the acetylcholine-induced contraction on ileum. Both the methanol fraction and CHCl(3)/MeOH sub-fraction caused marked reduction of barium chloride-, potassium chloride- and calcium chloride-induced contraction on guinea-pig ileum, indicating their interference with Ca(2+) ion movement. Thus, it may be concluded that various fractions derived from B. monniera possess broncho-vasodilatory activity, which is attributed mainly to inhibition of calcium ions.

Animals↗

Effect of impurities on the matrix-assisted laser desorption mass spectra of single-stranded oligodeoxynucleotides.

The effect of impurities on the analysis of single-stranded DNA oligomers by the technique of matrix-assisted laser desorption/ionization with time-of-flight mass spectrometry has been studied using the matrix 3-hydroxypicolinic acid and 355-nm pulsed light. By mixing the DNA oligomers with different concentrations of impurities and recording mass spectra, limits are set on the tolerable level of a given impurity in a sample. The tolerance limits for sodium chloride, potassium chloride, sodium acetate, sodium fluoride, sodium dodecyl sulfate (SDS), and manganese(II) chloride were found to be approximately 10(-2) M. It was found that magnesium salts degraded the mass spectrum at much lower levels of 10(-4) M. The organic compounds tris(hydroxymethyl)aminomethane (Tris), urea, dithiothreitol (DTT), glycerol, and ethylenediaminetetraacetic acid (EDTA), when present as its ammonium salt, were tolerable at concentrations into the range of 0.25-0.5 M, while the organic polyamine compound spermine substantially degraded the mass spectrum at concentrations above 10(-2) M. When comparing these results for DNA analysis with previously reported limits for protein analysis, large differences are seen for some of the impurities tested.

Base Sequence↗

Adrenalectomy reduces peripheral neural responses to gustatory stimuli in the rat.

In the rat, sodium need leads to an increase in sodium intake, which depends on salt taste sensitivity. The adrenalectomized rat, because of excessive body sodium loss, has been an important animal model for studying the physiological mechanisms underlying salt ingestion. In order to investigate the mediation by peripheral taste responsivity of changes in salt intake, multiunit responses of the chorda tympani nerve to various concentrations of sodium chloride, potassium chloride, lithium chloride, hydrochloric acid, and quinine hydrochloride were recorded from adrenalectomized and control rats. In order to control for a generalized decrease in sensory sensitivity, recordings from the auriculotemporal nerve to tactile stimulation of the pinna were also performed. There were no group differences in amplitude of the integrated neural responses to tactile stimulation. The largest decrease in gustatory responsivity occurred for suprathreshold concentrations of sodium chloride and lithium chloride. The data are discussed with reference to possible mechanisms underlying this neural alteration and to the role that reductions in salt taste responsivity play in mediating increases in salt intake.

Adrenal Glands↗

The 'compartmentation' of choline acetyltransferase within the synaptosome.

1. Choline acetyltransferase may be isolated in either a bound or soluble form after hypo-osmotic treatment of a crude synaptosome fraction, depending on the conditions. 2. In the bound form, the enzyme appears to be associated with the larger membrane fragments rather than with synaptic vesicles. 3. The bound form is predominant at slightly acid pH values and low ionic strength, the soluble form under more physiological conditions of pH and ionic strength. 4. Sodium chloride, potassium chloride, magnesium chloride and calcium chloride at similar ionic strengths solubilize the enzyme. 5. Choline acetyltransferase was found to be soluble under these conditions after release from synaptosomes from rat and pigeon cerebra, guinea-pig cortex and rabbit cortex, caudate nuclei, diencephalon and midbrain. 6. Certain isoenzymes of lactate dehydrogenase behaved similarly.

Acyltransferases↗