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At least 199 records · Page 11Linked to original sources
PubMedDate not supplied

Identical flow injection spectrophotometric manifold for determination of protein, phosphorus, calcium, chloride, copper, manganese, iron, and zinc in feeds or premixes.

A simple procedure using an identical manifold was developed for determination of nitrogen (protein) phosphorus, calcium, chloride, copper, manganese, iron, and zinc in feeds and feedstuffs. By changing appropriate reagents and detection wavelength, these 8 elements were determined successively with a simple identical double-line flow injection (FI) manifold. Fl spectrophotometric determinations were made by the blue indophenol reaction for ammonium, the molybdenum blue method for phosphate, the cresolphthalein complexone procedure for calcium, and the mercuric thiocyanate procedure for chloride. The chromogenic reagents for copper, iron, manganese, and zinc determination were bis(cyclohexanone)oxalydihydrazone (Cuprizone), 1,10-phenanthroline, formaldoxime, and xylenol orange, respectively. Sample digestion catalyst, Fl manifold, and some chemical parameters were optimized. The proposed procedure had a sampling rate of 90/h for each analyte. The determination ranges (mg/L) were 10-60 for N, 1-15 for P and Ca, 540 for Cl, and 0.5-15 for Cu, Fe, Mn, and Zn, respectively. Results of the analyses of animal feed and feedstuff samples by this procedure did not differ significantly from those obtained by proven manual methods.

Animal Feed↗
PubMed2002

Neuronal regulation of otolith growth and kinetotic behaviour.

Inner ear stones (otoliths) of larval cichlid fish were labelled with the calcium-tracer alizarin-complexone (AC) before animals were subjected to hypergravity (hg; 3 g). After the experiment, the otoliths' area between the two AC-labellings was measured. Growth of hg-otoliths was significantly slowed down as compared to 1 g-control specimens. In the course of a second experiment, the vestibular nerve was unilaterally transacted in neonate swordtail fish which were subsequently incubated in AC. Incorporation of AC was considerably lower in the otoliths of the transacted side. The results strongly suggest that otolith growth is continuously regulated in dependence of the environmental gravity vector. Since the otolithic calcium incorporation ceased on the transected head sides, it is concluded that the regulation of otolith growth is based on the central nervous efferent vestibular system.

Research Support, Non-U.S. Gov't↗
PubMed1976

[Isolation and properties of cytoplasmic L(+)-lactatoxydase of Candida lipolytica yeasts].

The enzyme preparation of L(+)-lactatoxydase (K.F. 1.1.3.2) with molecular weight of 230 000 has been isolated from the soluble fraction of the C. lipolytica cells and purified similar 360 times. The enzyme oxydizes L(+)-lactate, the optimum activity of the enzyme being observed at pH 8.0. Oxydation of the substrate is followed by accumulation of H2O2. Silver ions, p-chloromercurybenzoate and dicumarol inhibit the activity of L(+)-lactatoxydase. Iron complexones, cyanide and L-malate do not inhibit oxydation of the substrate. Pyruvate and its fluorine derivative practically do not produce any inhibiting effects either. The enzyme preparation contains 0.6 moles of flavin and 2 moles of nonhaem iron per a mole of the enzyme. Km value for the substrate is equal to 4-10(-4) M, Vmax--4.5 mkatom O/min/mg. Acidation of incubation medium leads to a decrease both of Km and Vmax. Km value for oxygen is equal to 3.1 mkM O2. Beside oxygen, ferricyanide, 2.6-dichlorphenolindophenol, phenazine methosulphate and cytochrome C may also serve as acceptors of L(+)-lactatoxydase electrons. The oxydized enzyme preparation is characterized by a spectrum absorption maximum at 410 nm. Upon L(+)-lactatoxydase reduction the maximum is shifted up to 420 nm.

Candida↗
PubMed1992

[Isolation and properties of intracellular peptidase from Brevibacterium].

The intracellular peptidase of Brevibacterium E531, a lysine-producing bacterial species, was purified 6500-fold by chromatography on DEAE-cellulose and the affinity adsorbent H-Thr(But)-Phe-Pro-hexamethylene-diamine-Sepharose 4B and by gel filtration on Sephadex G-200. The enzyme displayed the maximum activity towards proline p-nitroanilide at pH 7.7-7.9 and readily split glycine, alanine and proline from di-, tri- and tetrapeptides but did not practically hydrolyze oligopeptides of a greater chain length. The enzyme was not inhibited by complexons (EDTA, 8-oxiquinoline and 1.10-phenanthroline). The peptidase was not activated by divalent metal ions and was inhibited by Zn2+; Cd2+, Hg2+ and Cu2+. Data brom gel filtration on Sephadex G-200 suggest that the molecular mass of the enzyme is no less than 250 kDa. In the presence of sodium dodecyl sulfate the molecular mass of the enzyme is 43 kDa, which is suggestive of the presence of a quaternary structure. One peculiarity of the enzyme is its activation by alkaline metal halogenides and sodium nitrate which reaches a maximum at the 0.05-0.1 M concentration of the salts.

Aminopeptidases↗
PubMed2004

[The application of iron(III) complexing with different forms of DNA for the development of the biosensor for blood serum assay].

Fe(III) complexing with DNA was studied using spectrophotometric and voltamperometric data and mathematic simulation as well. The binding constant for the hypothetical complex Fe(III)-DNA 1:1 was 1.4 x 10(-5) mol(-1) x 1. Fe(III) complexes with various forms of DNA were characterized in terms of their composition and binding constants. The complex composition for the immobilized denatured DNA (d-IDNA) was found to be 1:2.25 (nucleotide:Fe(III)); this complex was characterized by the highest value of binding constant. d-IDNA was included into an amperometric biosensor for assay of Fe(II) content in human blood serum. The method of Fe(III) selective determination in the form of the complexonate was elaborated with the lower limit of detection of 1 x 10(-7) mol x l(-1). The linear region of Fe(III) detection was within the following concentration range 1.0 x 10(-7) - 6.0 x 10(-5) mol x l(-1). Determination of Fe(III) in the presence of matrix blood serum ions such as Mg(II), Zn(II), Cu(II) and Al(III) was carried out. The proposed method is well reproducible, characterised with an easy sampling and speed.

Biosensing Techniques↗
PubMed1992

Simple and sensitive determination of urea in serum and urine.

In this method for serum and urinary urea determination, the same reagent is used without predilution of urine samples. The method is based on the pH increase resulting from the ammonia released by urease hydrolysis of urea. o-Cresolphthalein complexone is used to monitor the pH change colorimetrically. Urea concentration and absorbance at 570 nm are linearly related for concentrations as great as 600 mmol/L for urine samples and 100 mmol/L for serum. There are no clinically significant interferences from physiological substances or drugs, and precision and accuracy are excellent (CV approximately 2%, except at very low concentrations in serum; analytical recovery was 99% in urine, 100% in serum). Results by this method (y) and by the Astra method (x) for urine correlated well (y = 0.991x - 2.87, Sy/x = 9.21, r = 0.994), as did the results by this method and by the total enzymatic method (x') for serum (y = 1.002x' + 0.192, Sy/x' = 0.598, r = 0.997). This method is applicable to automated as well as manual instruments, and one-reagent or two-reagent formats can be used.

Ammonia↗
PubMedDate not supplied

[The aggregative stability of human oxyhemoglobin in aqueous media in the presence of mercury(II) compounds].

The results are discussed of studies on oxyhemoglobin coagulation in neutral phosphate buffer and acidic acetate buffer at pH ranging from 5.85 to 4.90. Peculiarities are shown of the effect of strong complexon on the oxyhemoglobin-coagulum-mercuric acetate system in neutral tris-buffer. Coagulation characteristics are cited for polymeric oxyhemoglobin in presence of mercury ions.

Buffers↗
PubMed1991

[A highly sensitive immunoenzyme analysis using electrochemical detection].

The authors have developed a method for improving the sensitivity of electrochemical enzyme immunoassay, based on binding the enzymatic reaction volatile component to a complexone, followed by destruction of the complex in a flow-type amperometric detector. The lowest limit of the measured levels of blood serum antibodies and antigens is 10(-11)-10(-12) M. The method was tried in enzyme immunoassay of the blood serum IgE in patients with asthma and chronic obstructive bronchitis. Reduction of IgE level after therapy was found to be a regular feature; the authors claim that it may be considered as one of the criteria indicating the treatment efficacy.

Adult↗
PubMed1991

Arsenazo III: an improvement of the routine calcium determination in serum.

The widely used calcium dye reagent, o-cresolphthalein complexone, was replaced by the less well known metallochromic indicator Arsenazo III in a selective multitest analyser. Calibration stability increased from 12 hours to more than 48 hours. With the Arsenazo III reagent we clearly improved the within-lab and between-lab imprecision of the calcium determination. The accuracy of the Arsenazo III method was established with a reference method (atomic absorption spectrophotometry) and good results were obtained with assayed control sera. Furthermore, the mean calcium values of our out-clinic patients remained constant during the change of reagent. The calcium values are influenced by haemolysis; we correct for the observed decrease by adding 0.015 mmol/l Ca per 10 mumol/l Hb. Furthermore they are influenced by very small amounts of Cu ions from the preceding protein determination in the same cuvette. This latter problem is easily overcome by adding 15 mmol/l thiourea to the calcium reagent.

Arsenazo III↗
PubMed1990

[Ionic homeostasis and erythrocyte deformability in patients with primary arterial hypertension].

Erythrocyte Na, K-ATPase was examined for its activity and relation to the concentration of the complexon EDTA in 39 patients with arterial hypertension (AH), 12 subjects with borderline hypertension, and 18 normotensives. The ionic composition and deformability of erythrocytes were also studied. As compared to normotensives, the patients with Stage I AH displayed a significantly lower activity of erythrocyte Na, K-ATPase, which may suggest that there is an enzyme inhibitor in the blood of the patients. According to the enzyme activity, the patients with Stage II AH were divided into two subgroups: 1) those with a lower activity and 2) those with a higher activity than healthy subjects. The patients with a Stage II AH who showed a lower activity of Na, K-ATPase exhibited a more elevated erythrocyte sodium level, whereas those who had a high activity of the enzyme displayed a decreased erythrocyte deformability. In addition, a positive correlation between erythrocyte sodium concentrations and Na, K-ATPase activity, as well as erythrocyte deformability was found in normotensives, whereas a negative correlation was established in AH patients.

Adult↗
PubMed1989

[Study of fluorine and lead levels in selected vegetables and fruit grown within the range of emission of these elements by the household glass plant "Irena" in Inowrocław].

The content of fluorine and lead was determined by spectroscopic methods in the vegetables, fruit and flowers gathered in 1987 from the "Transportowiec" Garden Plots situated in the range of emission of these elements by the plant. Fluorine was isolated from plant materials by microdiffusion and determined spectrophotometrically as a triple complex: alizarine complexon + lanthanum + fluorideion. Lead was determined by atomic absorption spectrophotometry (ASA). Vegetables and fruit were raised in the range of 500 m from the emission source of the "Irena" plant. In only several vegetables the content of fluorine calculated for dry mass exceeded the Polish permissible level. On the other hand, the lead content in vegetables exceeded in 18.5% the Polish normal value and the suggested normal value of the Council of Mutual Economic Aid countries in 55.5%. The obtained results of fluorine and lead determinations were compared with those in the years 1981-1983 stressing the health hazards caused by consumption of vegetables and fruit from the gardens and fields situated in the vicinity of glass plant emission sources.

Fluorine↗
PubMed1988

[A slow spectral shift of cytochrome c oxidase induced by EDTA and o-phenanthroline].

Low concentrations of EDTA (in the presence of Ca2+ excess) or o-phenanthroline cause a blue shift of the oxidized cytochrome oxidase Soret absorption band. The effect develops within approximately 2 hours and does not depend on EDTA concentration provided the complexon is in a molar excess over the enzyme. It is suggested that the enzyme spectral characteristics depend on the presence of some tightly bound heavy metal ions which can stabilize one of the spectrally distinct conformations of cytochrome c oxidase.

Edetic Acid↗
PubMed1986

Analytical variance and definition of a reference change as a function of calcium concentration.

Using data from the Centers for Disease Control (CDC) Proficiency Testing (PT) Surveys, we obtained estimates of repeatability (intralaboratory variability between results on the same material) and reproducibility (interlaboratory variability between results on the same material) for the Technicon SMA 6 (or 12/60) and SMAC 1 (or II) systems used with cresolphthalein complexone methodology to measure serum calcium. The two systems were comparable in terms of short-term (within-day) repeatability, long-term (three to six months) repeatability, short-term (one to two weeks) reproducibility, and long-term (three to six months) reproducibility. The long-term repeatability was essentially the same as the long-term reproducibility. Short-term repeatability, long-term repeatability, and long-term reproducibility increased linearly with increased calcium concentration over the range 1.75 to 2.95 mmol/L; short-term reproducibility showed no significant change over this range. The effect of analytical variance on the definition of a reference change in semiannual calcium measurements was demonstrated.

Analysis of Variance↗
PubMed1986

[Compensatory factors in acute failure of the isolated heart].

The cardiac output of isolated guinea-pig hearts fell during progressive infusion of Ca2+-complexon, EGTA, or oxidative phosphorylation inhibitor dinitrophenol. Moderate doses of EGTA (0.3-0.6 mM) caused an apparent diminution of the left-ventricular +dP/dt and aortic pressure amplitude but did not influence cardiac output, which was maintained due to a prolongation of the contraction time. When the left-atrial cavity was greatly reduced by ligation, cardiac output fell by 40 per cent while left-ventricular systolic pressure and +dP/dt remained unchanged. In these conditions, EGTA in the same concentration reduced cardiac output by 30 per cent thus proving the important role of the left atrium in the compensation of hypocalcemic heart failure. On the contrary, the infusion of dinitrophenol shortened contraction time and increased myocardial rigidity. The latter change facilitated force development thus contributing to a lesser fall of +dP/dt and aortic pressure amplitude at equal diminution of cardiac output as compared to EGTA action. However, this compensation required a higher elevation of the filling pressure for inflow maintenance.

2,4-Dinitrophenol↗
PubMed1987

The hemolytic effect of copper complexes with different ligands.

The effect of Cu(II) and Cu(II) complexes/Cu(II)(cimetidine)2 Cu(II)(glycine) and Cu(II)(glycine)2/on the rat and human erythrocytes was studied. Time- and dose-dependence of the Cu(II) complexes-induced hemolysis, oxidation of hemoglobin and formation of precipitates of denaturated hemoglobin were established. The hemolytic effect of Cu(II)complexes was abolished by strong complexons of Cu(II) and by physiological concentrations of albumin and histidine. The hemolysis greatly decreased in the presence of chelator of Cu(I) and superoxide dismutase, which suggested oxi-reduction transitions and participation of superoxide in the process. The results are considered with the view to clarifying the differences in the stability and reaction ability of the different complexes, the possibility of their parenteral application.

Animals↗
PubMed1985

[Iron accumulation by saccharomycete yeasts growing on media with an elevated iron content].

In the absence of the artificial complexons of iron the intracellular iron content in yeast Saccharomyces cerevisiae are determined by the concentration of ions Fe(II) in medium. As iron is accumulated by yeast mainly in threevalency state the principal internal factor determining the intracellular iron content with existing concentration of Fe(II) in medium can be supposed to be redaction-oxidation state of yeast cell.

Chromatography, Gel↗
PubMed1985

[Effect of Na3Zn- and Na3Ca-DTPA on the behavior and biological action of 239Pu on rats].

The effect of a complexon therapy scheme including early (in 1 h) administration of Na3Ca DTPA and subsequent (in 1 day) administration of Na3Zn DTPA or Na3Ca DTPA at a dose of 25 mu Cimol/kg/day by three 2-week courses (5 times a week) with 2-week interruptions was studied in experiments on 541 male rats after intraperitoneal administration of 239Pu citrate complex (95 kBq/kg). The treatment resulted in a 3-fold lessening of the content of 239Pu and absorbed doses in the skeleton, a significant prolongation of the mean survival time (MST) from 452 to 593 days (Na3Zn DTPA) and 643 days (Na3Ca DTPA), and in a decrease of the osteosarcoma incidence from 76.4 to 32.6-41.2%. The ratio of osteosarcomas per 1 Gy retained in rats (0.076-0.083%) did not differ from that in untreated animals (0.067%) and varied within the ranges of established values (0.072-0.119%). The involvement of Na3Zn DTPA in the therapeutic scheme prolongs the MST of rats to a somewhat lesser degree than Na3Ca DTPA. No negative effects of Zn DTPA therapy were revealed.

Animals↗
PubMed1985

[Comparative analysis of the action of 2 calmodulin inhibitors on the contractile function of the isolated heart].

Ca2+-complexon EGTA and two calmodulin inhibitors: metaphenazine and trifluoperazine, induced similar effects on the cardiac contractile function: they diminished cardiac output, decelerated left ventricle pressure fall and increased both minimal--and end-diastolic pressure. Changes in the left ventricular pressure and its time course were more obvious during calmodulin inhibitor action as compared to EGTA at equal diminution of cardiac output. Trifluoperazine decreased left ventricular systolic pressure and resistance of coronary arteries to a greater extent than metaphenazine. The findings suggest participation of calmodulin in the regulation of myocardial relaxation mainly.

Animals↗