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PubMed1998

A case of pseudohyperkalaemia and thrombocytosis.

An unusual cause of "hyperkalaemia" was observed in a neurosurgical patient admitted to our intensive care unit. The cause of the hyperkalaemia was not known initially and treatment with cation ion exchange resin was initiated to lower the elevated serum potassium level. The concurrent occurrence of thrombocytosis and hyperkalaemia raised the possibility of psuedohyperkalaemia associated with thrombocytosis. Simultaneous measurement of plasma and serum potassium with the Hitachi 917 Analyzer (indirect ion selective electrode, coefficient of variation = 1% to 2%) confirmed the diagnosis. Correlation between thrombocytosis and pseudohyperkalaemia was found to be highly significant (r = 0.54; P = 0.014). It is estimated that for for every 100 x 10(9)/L of platelets, an increase of 0.07 to 0.15 mmol/L of potassium is expected. In thrombocytosis, plasma rather than serum potassium should be measured.

Cerebral Hemorrhage↗

PubMed1976

[Direct Quantitative Evaluation of Thin-Layer Chromatograms by Measuring Remission and Fluorescence (author's transl)].

A highly specific method for the estimation of free serotonin in urine is described. The technique is based on the separation of the serotonin from urine by an ion exchange resin, acetylation of the separated serotonin with subsequent extraction into an organic solvent followed by a thin-layer chromatographic separation. After t.l.c. the plates are sprayed with o-phthaldialdehyde (OPT), whereupon serotonin forms intense fluorescent spots, which can be measured directly. The reproducibily of this method is about +/- 7%.

Chromatography, Ion Exchange↗

PubMed1978

Production of valine by a Bacillus sp.

A bacterium isolated from Burdwan (India) soil was found to accumulate L-valine in the growth medium and identified to be a strain of Bacillus subtilis. The strain is able to grow and accumulate valine in a purely synthetic medium, but supplementation of the synthetic medium with either Casamino acids or yeast extract or with both, significantly improves the yield. The entire fermentation period can be divided into a growth phase and a production phase, which can be prolonged by adjustment of pH to the neutral range. Among the different carbon and nitrogen sources tested glucose at 8.5% and L-glutamic acid at 0.8%, respectively, were found most suitable. Cane sugar molasses tested as a substitute for glucose significantly stimulated growth but valine production was less. Different vitamins tested stimulated growth and valine yield and an inoculum level of 10% (v/v) of the medium was found to be optimal. The yield of valine under optimal conditions was found to be 4.53 g per litre of the medium. Valine has been isolated in crystalline form from the fermented broth by ion exchange resin chromatography and found to be a pure sample of the L-isomer.

Bacillus subtilis↗

PubMed1997

The influence of particle surface characteristics on pollutant metal uptake by cells.

The phosphatic mineral, hydroxyapatite, and two ion exchange resins have been used as artificial sediment particles. The surface properties of these materials have been studied using the Langmuir adsorption isotherm to calculate the binding capacity (B(max)) and the adsorption constant (K(L)) for zinc and cadmium ions. Mussels (Mytilus edulis) were fed on the particles and their digestive glands were subsequently removed and subjected to cell fractionation. The supernatant fraction was used to determine cytosol metal levels as a measure of the materials absorbed from the ingested particles. The level of cytosol zinc and cadmium was correlated with the K(L) values of the artificial sediments. It is suggested that phagocytosis of sediment particles plays an important part in transferring pollutants into benthic organisms and that the efficiency of this process is related to the adsorption coefficient of the particle surfaces.

Journal Article↗

PubMed1978

Sorbent-filled hollow fibers for hemopurification.

Filled hollow fibers were prepared and evaluated for application in hemosorption. Powdered activated carbon, urease-carbon, and macroporous ion exchange resins were used as fillers in highly permeable cellulose acetate hollow fibers. The carbon-filled hollow fibers had better mass transfer properties than encapsulated carbon in solid form. Zirconium phosphate and 2 synthetic zeolites were tested for ammonium ion adsorption from buffered saline and Ringer's salt solutions. Synthetic zeolites were found to have higher specificity and capacity for ammonium ion adsorption than zirconium phosphate. Projections are that hemosorption devices utilizing urease, carbon, and zeolites could remove all nitrogenous waste metabolites currently being treated only by dialysis. Oxystarch and oxystarch derivatives were tested for direct urea adsorption and were found unsuitable for this application.

Adsorption↗

PubMed1976

A method for the estimation of total calcium in serum or heparinized plasma.

A simple titrimetric method for the determination of total calcium in serum or heparinized plasma is described. After removing interfering substances with an ion-exchange resin, calcium is reacted with glyoxalbis (2-hydroxyanil), GBA, and the resulting red colour titrated with ethylenediaminetetra-acetic acid in the presence of a methanol/glycerol mixture. No special equipment is used, deproteinization is not necessary and only 0.2 ml of sample is required.

Autoanalysis↗

PubMed1990

High-performance liquid chromatographic assay of iomeprol in plasma and urine.

A high-performance liquid chromatographic method for assaying the radiographic contrast agent iomeprol in plasma and urine samples is described. Before reversed-phase chromatography, the biological fluids are treated with ion-exchange resins and iopamidol is added as internal standard. The compounds are monitored during elution by ultraviolet-visible spectrometry at 245 nm. The method shows good precision and accuracy and gives similar results to X-ray fluorescence analysis.

Chromatography, High Pressure Liquid↗

PubMed1977

Urinary oxalate estimation.

A method of estimating urinary oxalate is described. Impurities which might otherwise interfere with the estimation are removed by means of an ion-exchange resin. The oxalate is then reduced to glycolic acid, which forms a coloured compound with chromotropic acid. It can then be estimated colorimetrically. No special equipment is required, oxalate recovery is good, and the method is reproducible and precise.

Chromatography, Ion Exchange↗

PubMed2004

Lead biosorption by waste biomass of Corynebacterium glutamicum generated from lysine fermentation process.

Biomass waste, mainly Corynebacterium glutamicum, is generated from large-scale lysine fermentation process. In this study, protonated C. glutamicum biomass was evaluated as a biosorbent for the removal of lead from synthetic wastewater. As Pb2+ were bound to the biomass, the solution pH deceased, indicating that protons in the biomass were exchanged with lead ions. The Corynebacterium biomass bound Pb2+ at up to 2.74 mmol g(-1) at pH 5, where lead does not precipitate. Compared with other biosorbents and conventional sorbents, such as natural zeolite, activated carbon and synthetic ion exchange resin, the protonated C. glutamicum biomass was considered to be a useful biomaterial for lead biosorption.

Adsorption↗

PubMed2003

Studies of the effect of variation of blend ratio on permselectivity and heterogeneity of ion-exchange membranes.

Heterogeneous ion-exchange membranes (both cationic and anionic types) have been synthesized by solution casting techniques using polyvinyl chloride (PVC) as binder and ion-exchange resin (-300+400 mesh). The binder:resin ratio varied from 60:40 to 30:70. The transport behavior of the membranes has been evaluated chronopotentiometrically in sodium chloride (NaCl) solutions of different concentrations. The different parameters E(0) (potential drop across the membrane at the instant of application of current I), E(max) (maximum potential drop across the membrane after the application of current I), DeltaE (magnitude of the potential jump across the membrane at transition time tau), Itau(1/2), tau, etc., have been evaluated. The isoconductance points were determined and based on the microheterogeneous model proposed by Zabolotsky and Nikonenko (J. Membrane Sci. 79 (1993) 181) the distribution factors beta has been evaluated for both types of ion exchange membranes. The electroconductivity of the joint gel (kappa ) and pure gel phases (kappa ' ) has been determined. At any particular solution concentration the transport number as well as the permselectivity of membranes increases with increased resin content of the membrane. The microheterogeneity factor beta exhibits synchronization among the each set of four different membranes for both the cationic and anionic type.

Journal Article↗

PubMed1990

Purification of Thermus aquaticus DNA polymerase expressed in Escherichia coli.

DNA polymerase from Thermus aquaticus has become a common reagent in molecular biology because of its utility in DNA amplification and DNA sequencing protocols. A simplified method is described here for isolating the recombinant Taq enzyme after overproduction in Escherichia coli. Purification requires 8 to 10 h and entails heat treating and clearing the E. coli lysate, followed by precipitation of the enzyme with polyethyleneimine and elution from Bio Rex 70 ion exchange resin in a single salt step. The resulting enzyme preparation contains a single, nearly homogeneous protein consistent with the previously established size of the Taq DNA polymerase in a yield of 40-50 mg of protein per liter of cell culture.

Base Sequence↗

PubMed1979

Estimation of catecholamines in human plasma by ion-exchange chromatography coupled with fluorimetry.

Estimation of catecholamines in human plasma was made by ion-exchange chromatography coupled with fluorimetry. Catecholamines in deproteinized plasma were adsorbed onto Amberlite CG-50 (pH 6.5, buffered with 0.4 M phosphate buffer) and selectively eluted by 0.66 M boric acid. The catecholamine fraction was separated further on a column of Amberlite IRC-50 which was coupled with a device for the automated performance of the trihydroxyindole method (epinephrine and norepinephrine) or the 4-aminobenzoic acid-oxidation method (dopamine). One sample could be analysed within 25 min with either method. The lower detection limits were 0.02 ng for epinephrine and dopamine, and 0.04 ng for norepinephrine. Plasma catecholamine contents of healthy adults at rest were epinephrine 0.07 +/- 0.01 ng/ml (n = 19), norepinephrine 0.27 +/- 0.03 ng/ml (n = 19) and dopamine 0.22 +/- 0.03 ng/ml (n = 26). The procedure of adsorption and elution of the plasma catecholamines by ion-exchange resin was simple, the simplicity contributing to constant recovery. The catecholamine fraction could be analysed without evaporation of the eluate. The analytical column could be used for the analysis of more than 1000 samples before excessive back-pressure developed. Our method of continuous measurement of plasma catecholamine fulfils clinical requirements.

Catecholamines↗

PubMed1994

Operational properties of an inverted matrix cellulose CM ion-exchanger.

Productive CM is a recently available carboxymethyl ion-exchanger based on cellulose supplied by BPS Separation. It is supplied in an 'inverted matrix' form as a coherent structure with large voids and about 90% free volume. This paper reports mainly on the physical properties and robustness under normal use conditions using lysozyme as a model protein. The structure is shown by electron microscopy to be formed of fibrous or sheet material around macropores of around 100 microns in diameter. The material around the macropores is itself porous down to the smallest pores visible at perhaps 50 nm. The capacity under static and dynamic conditions was measured and found in both cases to be only slightly dependent on applied flow velocities up to 8 m h-1. The high porosity allowed cider fermentation broth and diluted egg white to be applied directly to a column without blockage and at a moderate pressure drop yet with a high superficial velocity. Compression of the bed at high flow rates did not occur at free space velocities up to 17 m h-1 with water and slightly lower with other fluids. The adsorption isotherm was determined and found to follow a Langmuir form. It proved to be totally stable to immersion in 1 M NaOH and 1 M NaCl without any measurable volume changes. Many of the properties were compared with those of other ion-exchange resins and found to be equivalent in capacity but superior in terms of stability, sustainable flow rates and dynamic capacity. It is concluded that the stability, performance under high flow rates and good capacity make it eminently suitable for use in large scale applications.

Adsorption↗

PubMed1985

The product-selective blot: a technique for measuring enzyme activities in large numbers of samples and in native electrophoresis gels.

A method termed "product-selective" blotting has been developed for screening large numbers of samples for enzyme activity. The technique is particularly well suited to detection of enzymes in native electrophoresis gels. The principle of the method was demonstrated by blotting samples from glutaminase (EC 3.5.1.2) or glutamate synthase (EC 1.4.7.1) reactions into an agarose gel embedded with ion-exchange resin under conditions favoring binding of product (glutamate) over substrates and other substances in the reaction mixture. After washes to remove these unbound substances, the product was measured using either fluorometric staining or radiometric techniques. Glutaminase activity in native electrophoresis gels was visualized by a related procedure in which substrates and products from reactions run in the electrophoresis gel were blotted directly into a resin-containing "image gel." Considering the selective-binding materials available for use in the image gel, along with the possible detection systems, this method has potentially broad application.

Chromatography, Ion Exchange↗

PubMed2001

Soil nitrate monitoring for turfgrass sod farms and other turf areas.

Studies with established turf and golf courses have indicated minimal risk of nitrate pollution of groundwater resulting from turfgrass management, but soil nitrate flux in turfgrass sod production farms and golf courses has received less attention. Information about nitrate-N flux at a particular location can be helpful to the sod producer or the golf course manager when efficiently applying N fertilizers and minimizing risk of nitrate pollution. We used an ion exchange resin capsule system to continuously monitor soil nitrate-N fluxes at 12 sites in southern Rhode Island, including turfgrass sod production farms and a low-maintenance environment. Four capsules were placed in the soil at each site and retrieved at intervals coinciding with management and meteorological events to determine nitrate ion accumulation. We found that the golf course green exhibited significantly higher nitrate-N fluxes than the sod farms and the low-maintenance turf. There was significant interaction between sampling date and study site, indicating that seasonal variation in soil nitrate-N fluxes was affected by turfgrass management. The cultural practice of late fall fertilization to stimulate early spring growth in the following year appeared to present some risk of nitrate loss during the winter from the golf course greens in our region. We conclude that site-specific and time-relevant monitoring is needed to produce and manage turfgrasses in an environmentally sound manner.

Agriculture↗

PubMed1978

A sensitive method for the assay of guanylate cyclase activity.

A method for the assay of guanylate cyclase is described utilizing alpha-[32P]-GTP as substrate for the enzyme reaction. 100-150 microgram of enzyme protein is incubated in a 15.6 mM Tris-HCl buffer incubation mixture, pH 7.6. The reaction is stopped by the addition of EDTA. The [32P]-cyclic GMP formed is separated by a two-step column chromatography on Dowex 50W-X4 ion-exchange resin and neutral alumina. The recovery for cyclic GMP was about 70%. The blank values ranged from 0.001-0.003% of the added alpha-[32P]-GTP which had been purified by Dowex 50W-X4 column chromatography. This method was employed for the assay of guanylate cyclase activities in different tissues.

Animals↗

PubMed1984

Morphological disruption of colonic mucosa by free or cholestyramine-bound bile acids.

In order to assess the effects of free or resin-bound bile acids on colonic topography, adult rats were surgically provided with an indwelling infusion catheter in the proximal cecum, which exited at the neck behind the head. Conscious, unrestrained rats were allowed chow ad libitum and were administered 1 ml of an infusion mixture twice daily for five days. The infusion mixtures included either carrier saline, 100 mg cholestyramine, 165 mumol mixed bile acids, or the bile acids bound to cholestyramine. Additional groups of rats were fed defined diets with and without 2% cholestyramine. Compared to fed controls, colonic infusions of saline had little effect on colon topography. Infusions of 100 mg of cholestyramine in saline twice each day did cause some apparent damage to surface morphology of the colon, but not to the extent observed during feeding of the resin as 2% of the diet. In contrast, extensive surface damage of the colon was observed by twice daily infusions of either 165 mumol of an equimolar mixture of cholic, deoxycholic, and chenodeoxycholic acids, or by the bile acids mixed previously with the ion-exchange resin. The data suggest that topographical damage of the colon observed during feeding of bile acid-sequestering resins is in large part due to increased concentrations of either bound or unbound bile acids in the large bowel.

Animal Feed↗

PubMed2000

Efficient preconcentration and separation of actinide elements from large soil and sediment samples

Large (approximately 10 g) soil and sediment samples are often required for analysis of low-level man-made actinides for monitoring environmental radioactivity. However, use of large environmental samples often results in significant chemical losses during chemical separations due to matrix interferences. We present a technique based on the ion-exchange resin Diphonix which selectively collects actinides and lanthanides into a common form, which then behaves uniformly and predictably during subsequent separation schemes. Diphonix is attractive for this purpose because it has an extremely high affinity for actinides and a low affinity for most common ions and is resistant to hydrofluoric acid. After being adsorbed onto Diphonix resin in a column mode at a pH approximately 1, actinides are completely eluted with 0.5 M 1-hydroxyethylidene-diphosphonic acid (HEDPA). After destruction of the HEDPA by ozonation or use of Fenton's reagent, Am, Pu, U, and Th are separated from each other and the remaining matrix by use of extraction chromatographic resins. We obtained high and consistent chemical recoveries (mean, 85%), as well as excellent chemical separations, for Am, Pu, U, and Th through the entire procedure for several 10-g soil and sediment samples.

Journal Article↗