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215 records · Page 12Linked to original sources
PubMed1980

[Cyclic nucleotide phosphodiesterase from wheat sprouts. Purification, properties, effect of systemic fungicides].

Cyclic nucleotide phosphodiesterase from wheat sprouts was isolated and partially purified. The molecular weight of the enzyme is about 83 000. The enzyme activity sharply rises as the inhibiting factors present in the homogenate are separated. The pH optimum of the enzymatic reaction is 4,8. Divalent cations (Mg2+, Mn2+, Cu2+) within the concentration range of 1--5 mM and complexons (EDTA, EGTA) at the concentration of 1 mM do not affect the PDE activity. The temperature optimum for the reaction is 60 degrees. The enzyme hydrolyzes 3' : 5'-AMP, 3' : 5'-GMP and 2':3'-AMP. The Km value for cAMP is 4 . 10(-3) M. The enzyme activity is inhibited by chemical agents possessing the fungicide activity, the strongest effect being exerted by anylate.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMedDate not supplied

[Ion transport in rat liver mitochondria after freezing and thawing].

Induction of ion transport in the rat liver mitochondria arising after their deep freezing is inhibited effectively by adenosine diphosphate, Mg ions, Ca2+ complexons (EDTA, EGTA) as well as by inhibitors of ATPase (oligomycin and dicyclohexylcarbodiimide) and of electrogenic transport of Ca2+ (ruthenium red). The value of ion flows is determined by adenine nucleotide concentration in the matrix. It is supposed that specific inhibitors of ion electrogenic transport promoting an increase in the transmembrane potential prevent from releasing adenine nucleotides from the mitochondrial matrix.

Animals↗
PubMed1981

Centrifugal analysis with automated sequential reagent addition: measurement of serum calcium.

We describe an automated method for calcium assay, for use with the Cobas-Bio centrifugal analyzer. Calcium is reacted with cresolphthalein complexone and the absorbance of the calcium--dye complex at 575 nm is measured. EDTA is then added to break up the calcium--dye complex and the absorbance at 575 nm is re-measured, to correct for endogenous color and turbidity. Day-to-day precision data, determined over four months, were as follows: mean = 92.9 mg/L, CV = 1.47%; n = 216; mean = 128.7 mg/L, CV = 1.72%; n = 216. Comparison of the Cobas-Bio method (y) with an atomic absorption spectrometric method (x) gave the following results: y = 1.012x--2.05, r = 0.991, Sy/x = 1.2, mean x = 92.63 mg/L, mean y = 91.69 mg/L, n = 74. Hemoglobin, bilirubin, or turbidity does not interfere. At the medical decision value (110 mg/L), the overall analytical error is 4.6 mg/L, which is less than the 5 mg/L allowable (95% confidence limit) error.

Autoanalysis↗
PubMed1983

Automated determination of crude protein, phosphorus, calcium, iron, and magnesium in feeds by using stopped-flow analyzer.

Methods are described for determination of crude protein, phosphorus, calcium, iron, and magnesium in feeds, using an automated microprocessor-based stopped-flow analyzer. Crude protein is determined by a reaction-rate procedure based on the ammonia-sodium phenate-hypochloride Berthelot reaction. Phosphorus determination is based on a phosphomolybdenum blue reaction-rate method. o-Cresolphthalein complexone, ferrozine, and calmagite are used as colorimetric reagents for calcium, iron, and magnesium, respectively. The methods are precise with relative standard deviations less than 1%, rapid with analysis rates of 110-266 samples per hour, sensitive, and require less than 1 mL sample and reagent volumes. Results for feed samples are comparable with those obtained by official AOAC methods.

Animal Feed↗
PubMed1983

Interference by hemolysis with various methods for total calcium and its correction by trichloroacetic acid precipitation.

We evaluated the influence of hemolysis on total serum calcium as determined with the Du Pont aca, SMA 12/60, Ektachem 400, Corning 940 EGTA titrator, and the Beckman Astra 8, comparing results with those obtained by atomic absorption spectroscopy. We find that hemoglobin does not influence calcium measurements with the SMA 12/60, Ektachem 400, or Beckman Astra 8. The presence of hemoglobin exceeding 2 to 3 g/L caused falsely high results with the aca and falsely low results with the Corning 940 titrator. Similar interferences may be observed with other titrating or colorimetric procedures that involve direct reaction of the sample with o-cresolphthalein complexone or calcein. Upon removal of the hemoglobin by precipitation with trichloroacetic acid, the values obtained with the aca and the Corning 940 EGTA titrator were similar to those measured by atomic absorption. With nonhemolyzed serum samples the acid treatment had little or no effect on the aca procedure but resulted in a positive bias of approximately 10% with the EGTA procedure. Thus we recommend this trichloroacetic acid procedure for measuring calcium in hemolyzed samples with the aca and, with certain reservations, with the EGTA titrator.

Autoanalysis↗
PubMed1982

[Coordination compounds of Pd(II) with potential antitumor activity].

The first results about the anti-neoplastic activity of Pd(II) ion coordinative compounds with complexones of the ethylenediamine-tetraacetic acid type are described. The assays employing Ehrlich ascites cancer of the mouse show that the presence of substitutes in the ethylenediamine skeleton originates important changes of the activity of such compounds.

Animals↗
PubMed1980

[Role of protein synthesis in the process of degradation of anomalous proteins in Escherichia coli cells].

The degradation of three types of anomalous proteins, e. g. those containing the arginine analog kanavanine; polypeptides synthesized in the presence of puromycin (100 micrograms/ml) under slight inhibition of total translation, and polypeptides synthesized under amino acid deficiency, was studied. In order to measure the rate of proteolysis, the E. coli cells were labelled for 5 min with [14C]-phenylalanine and then transferred to a complete medium. The loss of TCA-insoluble material was taken as a measure of proteolysis. While the normal total protein of E. coli cells was degraded at the rate of 2--8% per hour, the canavanine-containing proteins were degraded at the rate of 30--40% per hour. The polypeptides synthesized in the presence of puromycin were degraded at the rate of 10--15% per hour, while the polypeptides formed under amino acid starvation--at the rate of 7--8% per hour. The rate of proteolysis of canavanine-containing polypeptides was two times lower under inhibition of translation by chloramphenicol, tetracycline of kasugamicin, while the rate of degradation of two other types of anomalous polypeptides was significantly increased. Tetracycline at concentrations significantly exceeding those sufficient for maximal inhibition of translation, practically completely repressed the proteolysis of canavanine-containing proteins. No such tetracycline activity was observed in the presence of 20 mM Mg2+, which was assumed to be dependent on the complexon-forming ability of the antibiotic.

Amino Acids↗
PubMed1982

Bone scintigraphy in evaluating the viability of composite bone grafts revascularized by microvascular anastomoses, conventional autogenous bone grafts, and free non-revascularized periosteal grafts.

We studied the value of bone scintigraphy in the assessment of anastomotic patency and bone-cell viability in free bone grafts revascularized by microvascular anastomoses in twenty-seven dogs. The dogs were divided into three different groups, and scintigraphy was carried out using technetium-labeled methylene diphosphonate in composite bone grafts revascularized by microvascular anastomoses, conventional autogenous bone grafts, and periosteal grafts placed in different recipient beds. The viability of the grafts was evaluated by histological examination and fluorescence microscopy after triple labeling with oxytetracycline on the first postoperative day, alizarin complexone on the fourth postoperative day, and DCAF on the eleventh postoperative day. A positive scintiscan within the first week following surgery indicated patent microvascular anastomoses, and histological study and fluorescence microscopy confirmed that bone throughout the graft was viable. A positive scintiscan one week after surgery or later does not necessarily indicate microvascular patency or bone-cell survival, because new bone formed by creeping substitution on the surface of a dead bone graft can result in this finding.

Animals↗
PubMed1982

Total calcium and magnesium determined in serum with an automated stopped-flow analyzer.

We describe the measurement of total calcium and magnesium in serum with an automated microcomputer-controlled stopped-flow analyzer. The calcium method is based on the cresolphthalein complexone procedure, with 2-amino-3-methyl-1-propanol as the alkalinizing agent. The assay, performed on 60-fold prediluted samples, requires 50 microL of serum. Absorbance is measured at 580 nm for 1 s, after a 5-s delay. Response is linearly related to concentration up to 5 mmol/L; analytical recovery averaged 97.8%. Within-day CVs were 0.7 to 1.5%, day-to-day CVs 1.8 to 2.5%. Results compared well with those by continuous-flow Technicon SMA II method. A sample throughput of as many as 260 samples per hour is possible. The magnesium determination, a complexometric procedure, involves magnesium/calmagite complex in an alkaline reagent mixture and ethylene glycol bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid to eliminate calcium interference. Prediluted serum samples are used (100 microL of serum diluted 25-fold), and absorbance at 520 nm is linear with concentration to 50 mg/L. Within-run CVs were 0.5 to 1.1%, and day-to-day 1.3 to 3.8%; analytical recovery was 99.3%. Results compared well with those by atomic absorption spectrometry (r = 0.994). A delay time of 10 and a measurement time of 2.5 s allows for a throughput of as many as 180 samples per hour.

Autoanalysis↗
PubMed1995

[Sarcoidosis and urolithiasis].

OBJECTIVES: A retrospective study of patients with sarcoidosis and urinary lithiasis or lithogenic risk factors (hypercalcemia and hypercalciuria) was conducted to determine the degree of relationship of this disease with urinary lithogenesis. METHODS: From 1978 to 1993, 96 patients with sarcoidosis (68 females and 28 males), aged 17 to 77 years (mean 43 yrs), were evaluated. Serum and 24-hour urinary calcium were determined by the cresolphthalein complexone procedure. The presence of urinary lithiasis was determined from patient clinical data and/or the findings of the imaging techniques that had been utilized to evaluate these patients. RESULTS: 6.3% were hypercalcemic, 26.6% were hypercalciuric, 6.2% had a previous history of urolithiasis and 8.3% had a urinary calculus at the initial consultation. CONCLUSIONS: Hypercalciuria was present in about 25% of the patients with sarcoidosis, whereas approximately 15% had clinically documented urinary lithiasis.

Adolescent↗
PubMedDate not supplied

[A method of calculating complexed calcium in patients with in-vitro simulated hypo- and hypercalcemia].

Assessment of plasma protein calcium-binding capacity in disease involves measurements of Ca fractions in native plasma and its samples after in vitro stimulation of hypo- and hypercalcemia; such measurements include multiple and labor-consuming anaerobic ultrafiltration procedures. Values of Ca bound to plasma complexons and effective constants of their associations with Ca were experimentally assessed in 20 normal subjects, 7 patients before and 20 ones after kidney transplantation with the use of ultrafiltration. A method for estimation of integrated calcium in a sample lot has been developed, based on a single experimental value of integrated calcium in native plasma and the mean association constant in health. Experimental and estimated values of liganded Ca were in good correlation, this confirming the rightfulness of clinical use of the suggested method. This method essentially simplifies assessment of plasma proteins Ca-binding properties and requires lesser blood volumes.

Calcium↗
PubMed1993

New reagent for colorimetric assay of calcium in serum.

We report a new single-reagent colorimetric assay for the determination of calcium in serum. The assay is based on a novel chromogenic tetracarboxylic acid chelating agent. The method has several advantages over the o-cresolphthalein complexone (CPC) method, including improved linearity, better accuracy, increased stability, and lower working pH (9.0). The calibration curve for the assay is linear up to 4 mmol/L. The results for 47 patients' samples correlated well with results obtained with an Instrumentation Laboratory atomic absorption spectrophotometer. The mean (+/- SD) calcium values for the new method were 2.27 +/- 0.06 mmol/L and 2.26 +/- 0.05 mmol/L for the comparison method. The on-system stability of the reagents is 1 week vs 8 h for the CPC method.

Calcium↗
PubMed1996

New enzymatic assay for calcium in serum.

We established a simple and rapid kinetic assay for measurement of calcium in serum by using urea amidolyase (EC 3.5.1.45) from yeast species. The method is based on inhibition of the enzyme by calcium. In the assay, we eliminated endogenous ammonium ion by use of glutamate dehydrogenase (GLDH; EC 1.4.1.4); then in the presence of urea amidolyase, urea, ATP, bicarbonate, magnesium, and potassium ions, ammonium ion production was inversely proportional to calcium ion concentration in serum. The concentration of ammonium ion formed was determined by adding GLDH to produce NADP+ in the presence of 2-oxoglutarate and NADPH; we then monitored the change of absorbance at 340 nm. The within-run CVs of this method were 1.7-3.2% (n = 10) at 1.53-3.08 mmol/L, respectively. Day-to-day (total) CVs were 2.8-4.1%. Analytical recovery was 92-112%. The presence of other ions, ascorbic acid, reduced glutathione, bilirubin, hemoglobin, citrate, lipemic material, or human serum albumin did not affect this assay system. The correlation between values obtained with our method (y) and o-cresolphthalein complexone method (CPC) (x) was: y = 1.001x + 0.077 mmol/L (r = 0.949, Sy[symbol: see text]x = 0.079, n = 100); with the other enzymatic method (x) it was: y = 0.952x + 0.021 mmol/L (r = 0.955, Sy[symbol: see text]x = 0.074, n = 100). The SEs for each method were: 0.025 mmol/L, our method; 0.023 mmol/L, CPC method; and 0.025 mmol/L, the other enzymatic method.

Adenosine Triphosphate↗
PubMed1977

Hemoglobin interference with Du Pont Automatic Clinical Analyzer procedure for calcium.

Hemoglobin in concentrations of approximately 2.5 g/liter or greater significantly increases values for apparent calcium in serum as determined with the Du Pont aca, an interference attributable to the 575-nm absorption band of oxyhemoglobin being uncompensated by the 577--600 nm differential absorption reading of the calcium o-cresolphthalein complexone complex.

Autoanalysis↗
PubMed1997

[A pain syndrome of compression-reflex origin: the mechanisms of its development and the means for its therapeutic management].

Complex observation and treatment of 112 patients with compressive-reflex syndromes of cervical osteochondrosis with pain as the leading clinical manifestation resulted in elaboration of the scheme of its pathogenesis. The main links of pathological process development as well as their relationships were described. The main means and methods of the correction of algesic syndrome development were determined on the basis of both own investigations and literary data. The peculiarity of this study was the inclusion of Xydiphone (the Russian-made drug from complexons group) in pathogenetic therapy. Its positive medical effect in treatment of the disease described was established.

Adult↗
PubMed1978

[Effect of combined administration of hydrocortisone and EDTA on the number of the antibody-producing cells in the spleen of mice immunized with sheep erythrocytes].

Experiments on mouse hybrids (CBA X C57BL)F1I indicated that injection of hydrocortisone in a dose of 1 mg/mouse 24 hours after the immunization with sheep red blood cells against the background of multiple EDTA injection resulted in a relative reduction of the plaque-forming cells in the spleen--more than 6-fold in comparison with control, and more than 3-fold in comparison with the effect of hydrocortisone or EDTA alone. This may possibly be the consequence of a more intensive hydrocortisone incorporation under conditions of prolonged hypocalciemic action of EDTA complexon.

Animals↗