Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Potassium Compounds”

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 1,117 records · Page 62Linked to original sources
PubMed1991

Separation of human serum lipoproteins into three major classes by hydroxyapatite chromatography.

The separation of normolipidemic male serum lipoprotein fraction, prepared by ultracentrifugal flotation, was studied on hydroxyapatite columns. Potassium phosphate buffers in the pH range 5.6-7.4 were evaluated as eluents. The three main classes of the lipoproteins (high density, low density and very low density) can be separated on the Tiselius-type hydroxyapatite (Bio-Gel HTP DNA grade) column by elution with 75, 250 and 300 mM potassium phosphate buffer (pH 7.4), respectively.

Buffers↗
PubMed1995

Complementary use of counter-current chromatography and hydroxyapatite chromatography for the separation of three main classes of lipoproteins from human serum.

High-density, low-density and very-low-density lipoproteins (HDLs, LDLs and VLDLs) were purified from human serum by the combined use of counter-current chromatography (CCC) and hydroxyapatite chromatography. Polymer-phase CCC of human serum using the cross-axis coil planet centrifuge yielded two lipoprotein fractions, one containing HDLs and LDLs and the other VLDLs and serum proteins. Each fraction was concentrated and subjected to hydroxyapatite chromatography to obtain three lipoprotein fractions, all free from serum proteins. Each lipoprotein was confirmed by agarose gel electrophoresis.

Chromatography↗
PubMed1996

Protein partition between the different phases comprising poly(ethylene glycol)-salt aqueous two-phase systems, hydrophobic interaction chromatography and precipitation: a generic description in terms of salting-out effects.

The solution behaviour of selected proteins has been studied under conditions promoting precipitation, binding to mildly hydrophobic adsorbents or partition. Solvophobic theory may be used to describe these forms of protein partition. The tendency of a protein to partition therein is dependent upon surface properties of the protein solute mediated by the concentration and nature of added salts. As applied to partitioning in poly(ethylene glycol) (PEG)-salt systems this implies that linear (Brönsted) relationships apply only to proteins partitioned close to the critical point. At longer tie-line lengths protein partitioning is increasingly influenced by salting-out forces. This is confirmed by the observed behaviour of the proteins. The point at which this behaviour changes has been unambiguously defined enabling the direct comparison of phase transition of proteins during partition in all systems. The results obtained show that phase transition during adsorption and partition occur at similar concentrations of salt. This is less than that required to promote precipitation. It appears, from these limited studies, that top-phase preferring proteins are partitioned at salt concentrations above those required to cause adsorption. Proteins preferring the lower phase are partitioned at salt concentrations close to or below those required for adsorption. This raises questions regarding the solvated molecular form of the partitioned proteins and the definition of the partition coefficient.

Chemical Precipitation↗
PubMed1996

Determination of a HIV protease inhibitor (DMP 450) in animal and human plasma by solid-phase extraction and high-performance liquid chromatography.

Extraction of DMP 450 from plasma was performed with C2 solid-phase extraction columns, using 0.1 M ammonium acetate in 90% methanol to elute DMP 450. The extraction recovery over the range of 10 to 10 000 ng/ml averaged 81.0, 96.2, 77.4, 95.2 and 68.0% from rat, dog, monkey, chimpanzee (25-10 000 ng/ml) and human plasma, respectively. HPLC analysis was carried out with a C18 column and a mobile phase of acetonitrile, methanol and 30 mM potassium phosphate (pH 3), the composition dependent on the type of plasma being analyzed, and monitored at a wavelength of 229 nm. Intra-day and inter-day coefficients of variation were less than 9.9 and 12.9%, respectively. Absolute differences were less than 11.5%.

Acetonitriles↗
PubMed1996

Impact of cell disruption and polymer recycling upon aqueous two-phase processes for protein recovery.

A practical study is presented of the influence of cell debris and polymer recycling upon the operation of two-stage aqueous two-phase systems (ATPS) for the recovery of yeast bulk protein, pyruvate kinase and fumarase. Brewers' yeast was disrupted using one of two types of high-pressure homogenisers or a bead mill. The different cell debris suspensions were partitioned in a single PEG-phosphate ATPS extraction and the efficiency of solid-liquid separation was examined. A continuously operated two-stage ATPS process, using spray columns, is presented and practical problems of polymer recycling are discussed. Conclusions are drawn concerning the generic implementation and operational stability of ATPS in practical protein recoveries.

Buffers↗
PubMedDate not supplied

Urinary excretion of N-acetyl-beta-glucosaminidase and beta-galactosidase by patients with epilepsy.

In an effort to detect active renal tubular dysfunction in 74 epileptic patients being treated with antiepileptic drugs (AEDs), we measured the urinary activity of two lysosomal enzymes, N-acetyl-beta-glucosaminidase (NAG) and beta-galactosidase (beta-gal). The heterogeneity of the types of seizures and therapeutic regimens permitted us to examine the potential differences in AED effects. We also examined the chronological changes in the urinary excretion rates of NAG and beta-gal in 132 healthy controls, aged 3 months to 37 years. Increased NAG excretion rates (defined as > or = 2 S.D. compared with age-matched controls) were found in 36.5% of the patients. Valproic acid was highly associated with this increase, and in combination with potassium bromide caused the highest levels of NAG excretion. Among the patients taking carbamazepine, only 11.1% exhibited high levels of NAG in urine. Children under 1 year of age showed higher levels of NAG excretion than older patients. In spite of the abnormally high urinary excretion of NAG, we could not detect any signs of renal dysfunction by urinalysis and measurement of blood urea nitrogen and serum electrolytes. We cannot exclude the possibility that the increased levels of urinary NAG in epileptic patients might be due to renal tubular enzyme induction by AEDs.

Acetylglucosaminidase↗
PubMedDate not supplied

A comparison of calcofluor white, potassium hydroxide, and culture for the laboratory diagnosis of superficial fungal infection.

A total of 207 skin scrapings were prospectively studied using potassium hydroxide (KOH), calcofluor white (CW), and culture to determine the clinical usefulness of each microscopic method. For dermatophytes (prevalence 13.2%), CW had a sensitivity of 92% and a specificity 95%, giving a positive predictive value of 74% and negative predictive value of 99%. KOH had a sensitivity of 88% and a specificity of 95%, giving a positive predictive value of 73% and a negative predictive value of 98%. CW was simple, rapid, and easy to read. For dermatophyte infection, CW results are as useful as KOH results.

Arthrodermataceae↗
PubMed1991

Alkalinity of non-industrial cleaning products and the likelihood of producing significant esophageal burns.

Alkaline cleaning products are a cause of serious esophageal injury. Over time, legislation has diminished the concentration of many such non-industrial solutions and solids; however several products presently do not list either the pH or relative concentrations of alkaline constituents. This study measures the pHs of several non-industrial cleaning products containing either ammonium chloride, sodium hydroxide, or potassium hydroxide. Three pH measurements were performed on each of 10 non-industrial alkaline cleaning products (eight liquid, two solid). Two 0.1% ammonium chloride solutions had pHs of 12.06 +/- 0.00 and 12.06 +/- 0.01, whereas a pH of 12.43 +/- 0.00 was recorded in a 0.2% ammonium chloride solution. Concentrations of sodium hydroxide and potassium hydroxide were listed on only one of five liquid cleaning product labels. The pHs for these five products varied between 12.83 +/- 0.009 and 13.5 +/- .0.2. The pHs of three sodium hydroxide solutions differed from values reported in Micromedex (Micromedex Inc, Denver CO) by up to 0.32 pH units. Ten percent (v/v) solutions of two solid lye products had pHs of 13.62 +/- 0.008 and 13.74 +/- 0.02. The investigator found that selected non-industrial cleaning products, including ammonia solutions, retain the ability to cause clinically important esophageal damage.

Ammonium Chloride↗
PubMed1991

Saltpeter ingestion.

A 37-year-old man presented to the emergency department after an attempt to self-treat his priapism with saltpeter (K+NO3). Initially he had a potassium of 7.6 with electrocardiographic changes and a markedly elevated CO2. The potassium and carbon dioxide normalized in less than 24 hours with standard treatment for hyperkalemia. Hyperkalemia is expected with large oral potassium ingestion; and the elevated CO2 was spurious, caused by the misreading of serum nitrates by the Ektachrom 700 system. Ingestion of K+NO3 should be added to the differential of hyperkalemia with a markedly elevated CO2.

Adult↗
PubMedDate not supplied

Profound atelectasis following alkaline corrosive airway injury.

We report a case of life-threatening acute atelectasis following intubation for alkaline corrosive injury to the upper airway. The risk factors for and diagnosis of acute atelectasis as well as current methods of treatment are reviewed. It is important for emergency physicians to be familiar with this potentially fatal respiratory emergency during care for acutely ill and injured patients.

Bronchi↗
PubMed1988

Routine synthesis of N-[11C-methyl]scopolamine by phosphite mediated reductive methylation with [11C]formaldehyde.

A synthesis of [11C]scopolamine capable of clinical delivery of this agent in high specific activity is described. The precursor [11C]formaldehyde was produced by catalytic oxidation of [11C]CH3OH over metallic silver and was used to N-11C-methylate norscopolamine using aqueous neutral potassium phosphite as the reducing agent. The labeling reaction was complete after 5 min at 75-80 degrees C and the [11C]scopolamine (99% radiochemical purity) was isolated by preparative HPLC. Total synthesis time is less than 45 min. Decay corrected radiochemical yields from [11C]CO2 are presently 20-43%.

Carbon Radioisotopes↗
PubMed1989

Cyclic AMP does not alter taurine accumulation by rat renal brush border membrane vesicles.

Secondary hyperparathyroidism has been attributed to be responsible for the generalized aminoaciduria and phosphaturia of vitamin D deficiency. Since PTH acts in the kidney to generate cAMP, we explored the possibility that its synthetic analog, dbcAMP, would alter the renal transport of taurine (an amino acid lost in the urine in vitamin D deficiency) and Pi. Exposure of renal BBMV prepared from normal and vitamin D-calcium-deficient rats to dbcAMP at concentrations ranging between 10(-4) and 10(-7) M did not alter taurine uptake by these vesicles. Higher dbcAMP concentrations blunted uptake, but these concentrations reduced intravesicular volume, thus representing an artifact of osmolarity. Preincubation of BBMV with dbcAMP for times between 0 and 60 min at 0 or 25 degrees C also did not alter taurine accumulation. Hypotonic lysis of BBMV, allowing entry of the cyclic nucleotide, followed by isotonic resealing did not influence taurine uptake. The addition of potassium fluoride (to inhibit phosphodiesterase activity) and ATP (as an energy source) did not alter taurine accumulation at 60 sec. The uptake of Pi, which is influenced by PTH, was decreased by 25% following exposure to dbcAMP on the internal surface of the vesicle. These data indicate that the taurinuria observed in vitamin D deficiency is unlikely to be related to a PTH-induced increase in intracellular cAMP, unlike the changes in Pi transport, which is sensitive to cyclic nucleotides.

Adenosine Triphosphate↗
PubMedDate not supplied

Insulin sensitivity and blood lipids during antihypertensive treatment with special reference to ACE inhibition.

NIDDM and hypertension are both characterized by insulin resistance and/or hyperinsulinemia. In IDDM, factors associated with nephropathy produce hypertension. To avoid exacerbation of the metabolic condition, and to prevent further deterioration in glycemic control, treatment of hypertension in the diabetic patient should include the administration of medication with the fewest adverse effects on glucose homeostasis. If diuretics are to be used, it appears that loop diuretics may be preferable to the thiazides or potassium-sparing compounds. Among the remaining classes of antihypertensive drugs, ACE inhibitors may be the agents of choice because of their potential positive effects on insulin sensitivity and renal function, and their lack of severe adverse side-effects.

Adrenergic beta-Antagonists↗
PubMed1991

The history of nitrite in human nutrition: a contribution from German cookery books.

In order to settle the question of when saltpetre (nitrate) came in use as an additive to human food, a number of historic cookery books from Germany and Austria were reviewed. Obviously, the change from vegetable dyes to saltpetre for the coloring or color preservation, respectively, of meat occurred between 1600 and 1750, probably near 1700. The addition of sugar which favours the reduction of nitrate to the active agent nitrite became common practice during the 19th century. Thus some historic parallels to the appearance of colorectal cancer, multiple sclerosis and rheumatoid arthritis in the medical literature became apparent.

Colonic Neoplasms↗
PubMed1989

A metabolically stable analog of 1,4,5-inositol trisphosphate activates a novel K+ conductance in pyramidal cells of the rat hippocampal slice.

IP(s)3, a metabolically stable analog of 1,4,5-inositol trisphosphate (IP3), inhibited action potential firing when injected into hippocampal pyramidal cells. This effect was associated with decreased input resistance, a more negative resting potential, outward rectification at depolarized potentials, and an afterhyperpolarization. The response to IP(s)3 was unaffected by antagonists of Na+, Ca2+, and Cl- conductances, but was sensitive to changes in extracellular K+ concentration. The IP(s)3-induced conductance was voltage-dependent, was activated in 10 ms with depolarization, and was blocked by extracellular Ba2+ or intracellular Ca2+ chelation. It was not suppressed by other K+ conductance antagonists. Thus, IP(s)3 may activate a novel K+ conductance in CA1 pyramidal cells. IP3 itself did not elicit this conductance, suggesting it may be rapidly metabolized in these cells.

Action Potentials↗