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Results for “POLAROGRAPHY”

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PubMedDate not supplied

Differential pulse polarographic determination of BCNU pharmacokinetics in patients with lung cancer.

BCNU levels were determined by differential pulse polarography in 12 patients with lung cancer. A simple assay method for submicrogram quantities of nitrosoureas is described. The half-life of BCNU added to plasma in vitro was 1413 mins at 0 degrees C and 12 mins at 37 degrees C during incubation. BCNU kinetics in blood of treated patients was calculated using the two-compartment open model; the half-life of the drug was 1.4 mins in the first phase and 17.8 mins in the second. Mean distribution volume was 2.59 liters/kg and plasma clearance was 16.7 ml/min/kg.

Aged↗

PubMed1981

[Polarographic method of determining oleandomycin].

It was shown with the use of classical and differential polarography that oleandomycin in aqueous solutions undergoes electrolytic reduction on the mercury-dropping electrode. The polarographic wave of the reduction was distorted with adsorption phenomena. Its height was proportional to the analytical concentration of oleandomycin in the solution. The polarographic study on the process of acid and alkaline hydrolysis showed a satisfactory correlation between the height of the oleandomycin peak on the differential polarogramme [Formula: see text] and the biological activity of the antibiotic in the solution. The quantitative analysis implies recording of the data of the differential polarogramme of the test-solution and measurement of the antibiotic concentration with the calibration graph. Comparison of the results of determination of the oleandomycin levels in oleandomycin phosphate drugs and fermentation broth filtrates with the polarographic and micro-biological methods revealed no systematic deviations and showed that the average casual deviation between the results was due only to the errors of the methods reproducibility.

Biological Assay↗

PubMed1980

[Bismuth osteoarthropathies. Concern with bone bismuth dosage].

Impulsion polarography with anodic redissolution, a very sensitive means of dosage that is easy to repeat and more selective than atomic absorption, makes it possible to affirm the presence of bismuth in the bones after oral or parenteral treatment in 6 patients, 5 of whom suffered from osteoarthropathies that could be linked, given their nature, to the treatment administered, though this could not be proven. The presence of bismuth in the bone tissue of these patients must be considered in the physiopathological discussion of their osteoarthropathies, especially since none of them showed signs of encephalopathies.

Adult↗

PubMed1995

[A study of the content of synthetic food dyes in gelatin jellies].

Methods of identification and quantitative determination of synthetic dyes in gelatine jellies have been described. Extraction and isolation procedures of synthetic food dyes have been developed specifically for gelatine products. The various techniques have been used as follows: paper chromatography, absorption spectrophotometry and polarography. Tartrazine, Cochineal Red and Indigotin in amounts permitted by Polish legislation have been determined.

Chromatography, Paper↗

PubMed1994

[Duodenal function in some diseases of upper abdominal organs].

Eighty-five children with surgical parasurgical and pediatric abnormalities of upper abdominal organs were studied. In addition to the routine procedures, the authors used the following: endoscopic stepwise manometry, electromyography, polarography, pH-metry. In some chronic pediatric diseases, manometric, polarographic, electromyographic changes were found to correlate with the similar ones in surgical abnormalities. The findings provide strong evidence for the necessity of more comprehensive examinations of the duodenum in children with surgical and pediatric upper abdominal abnormalities in order to earlier detect the indications for surgical treatment, to assess the outcomes of treatment and to predict the course of rehabilitation.

Child↗

PubMed1978

Carcinogenicity and polarographic behavior of dibenz[a,h]anthracene, dibenz[a,h]acridine and dibenz[a,h]phenazine.

In a simultaneous test of carcinogenicity the authors have studied the activities of dibenz-[a,h]anthracene, dibenz[a,h]acridine and dibenz-[a,h]phenazine. These compounds were dispersed in paraffin disks and subcutaneously implanted in rats. Each experimental group consisted of 30 animals. The number of sarcomas induced by the above-mentioned compounds was 20, 5 and 3 respectively. Tumorigenicity of the aza analogues of dibenz[a,h]anthracene was proportional to their electron donation and inversely proportional to their electron acceptance in the performed polarographic test. The authors discuss the possibilities of using polarography as a screening test for the exclusion of carcinogenic polycyclic compounds.

Acridines↗

PubMed1994

[Polarographic determination of N,N'-methylene-bis(2-amino-1,3,4-thiadiazole) in water].

The polarographic behavior of the product of N,N'-methylene-bis(2-amino-1,3,4-thiadiazole) (I) with nitrite and N-(1-naphthyl)-ethylendiamine is reported. The effects of acidity and reagents on the polarography was studied, and a polarographic method was established for the determination of (I). The relative standard deviation was 2.2-8.4%, and the recovery in the range of 80-103%. The proposed method was sensitive, accurate, reproducible and suitable for the determination of microamount of (I) in water.

Insecticides↗

PubMedDate not supplied

[The morphofunctional characteristics of the blood supply to the oral mucosa in the absence of teeth and their prosthesis].

Morphofunctional features of blood supply to the buccal mucosa were studied by rheography, polarography, light and electron transmission microscopy and stereo-morphometry in patients with partial adentia and after they were fitted with prostheses. Adentia changed the functional parameters, this being indicative of reduced circulation. Morphologically it manifested by microvessel stasis, red cell sludging, stromal edema and polymorphonuclear infiltration. Endothelial ultrastructure and ultrastructure of other microvessel components indicated impaired permeability. Fitting with prostheses resulted in recovery of the functional parameters and of the buccal mucosa morphology. All the parameters sooner normalized if bridge prostheses were implanted. Circulatory functional parameters and buccal mucosa microvessel structure were in good correlation.

Adolescent↗

PubMed1993

[The potentials for noninvasive diagnosis in predicting the effect of a reconstructive operation in patients with severe ischemia of the lower extremities].

The paper discusses whether the outcome of reconstructive surgery can be predicted by using the orthostatic test in Doppler sonography and transcutaneous polarography. A total of 97 patients with severe lower extremity ischemia were studied, of them 87 were operated on. Reconstructive operations on the vessels were performed in 72 patients. There was no relationship between the value of the humero-mallear index of regional systolic pressure as well as TcpO2 and the outcome of an operation. At the same time there was a correlation between the orthostatic rise in regional systolic pressure on the tibial arteries at the ankle-bone and the orthostatic increase in pO2 in the feet and the outcome of a reconstructive operation. The orthostatic rise in pO2 and regional systolic pressure was 8.06 +/- 4.0 and 58.2 +/- 5.43 mm Hg in patients with poor outcomes and inoperable patients, respectively. In good outcomes, these figures were 17.8 +/- 2.14 and 91.3 +/- 3.64 mm Hg (p < 0.05), respectively. The positive outcome of a reconstructive operations was observed in 88.8 = 92.0% patients with an orthostatic rise of pO2 in the feet by more than 20 mm Hg and that at the ankle-bone by more than 90 mm Hg.

Acute Disease↗

PubMed1977

Regional cerebral blood flow with intracranial mass lesions. Part I: Local alterations in cerebral blood flow.

Focal changes in the cat cerebral blood flow were studied by the technique of H2 polarography. Areas studied included the caudate nuclei, thalami and midbrain. A unilateral mass effect was created by inflation of an epidural balloon. A rapid decrease in regional cerebral blood flow was noted ipsilateral to the mass at very small balloon volumes. This was followed closely by contralateral supratentorial decrease in regional cerebral blood flow. The normal midbrain blood flow was found to be preserved until total decompensation (herniation) occurred.

Animals↗

PubMed1995

In vitro and in vivo comparative studies on chelation of aluminum by some polyaminocarboxylic acids.

Since desferrioxamine exhibits toxic effects, the possible use of several other therapeutic agents in acute aluminum intoxication has been investigated in this study. The potential for the chelation of aluminum (Al) by different compounds has been first determined using two in vitro techniques. The formation of stable complexes with Al in an aqueous solution has been evaluated by using pulse polarography. This technique allows the influence of temperature and of calcium (Ca) to be studied for each compound. Certain compounds (HEDTA, DTPA) showed extensive chelation in the presence of Ca2+ at a temperature of 37 +/- 1 degree C. An ultrafiltration technique combined with Al determination by atomic emission spectroscopy (A.E.S.) has allowed the ability of different substances to complex Al that was previously bound to serum proteins, to be estimated. The kinetics of chelation and the minimum efficient concentration have been determined for all of the products studied. The real efficacies of the compounds were studied by in vivo investigations to compare the effectiveness of the best chelating agents (DFO, HEDTA and EDTA) on the distribution and excretion of Al, after repeated i.p. administration to rats. HEDTA shows a chelation potential as widely active as the DFO potential.

Acetates↗

PubMed1995

In vitro and in vivo evaluation of potential aluminum chelators.

The potential for aluminium (Al) chelation by different compounds was determined using 2 in vitro techniques. The formation of stable complexes with Al in an aqueous solution was evaluated using pulse polarography. This technique allowed the influence of temperature and calcium (Ca) to be studied for each compound. Certain compounds (EDDHA, HAES, citric acid and HBED) showed great chelation in the absence of Ca2+ at a temperature of 37 +/- 1 C. An ultrafiltration technique combined with Al determination by atomic emission spectroscopy allowed the efficiency of different substances to complex Al that were previously bound to serum proteins to be estimated. The kinetics of chelation and minimum efficient concentration have been determined for all products studied. EDDHA had chelation potential similar to DFO. The real efficacies of the compounds were studied in vivo to compare the effectiveness of repeated administrations of the best chelating agents (EDDHA, DFO, HAES and tartaric acid) on the distribution and excretion of Al after repeated i.p. administrations to rats. Intraperitoneal EDDHA significantly increased urinary metal (Al, Ca, Cu, Fe and Zn) excretion. These excretions may be correlated to a renal toxic potential property.

Aluminum↗

PubMed1996

The potential of electroanalytical techniques in pharmaceutical analysis.

With the considerable progresses observed in analytical instrumentation, it was of interest to survey recent trends in the field of electroanalysis of drugs. Potentiometric, voltammetric and amperometric techniques were scrutinized both in terms of historical evolution and in terms of potentialities with respect to the analysis of drugs in various matrices. With regard to the former, it appeared that numerous original selective electrodes (for drugs and ions) have been studied and several ion-selective electrodes have been successfully commercialized. Improvements are still expected in this field in order to find more robust membrane matrices and to minimize the surface fouling. Electrochemistry is well suited for trace metal analysis. A renewed interest in potentiometric stripping analysis is observed and is stimulated by the power of computers and microprocessors which allow rapid signal recording and data handling. Polarography and its refinements (Pulsed Waveform, Automation,...) is ideally applied for trace metal analysis and speciation. The technique is still useful in the analysis of drug formulations and in biological samples provided that the method is adequately validated (selectivity!). The same holds for solid electrodes which are currently routinely applied as sensitive detectors after chromatographic separation. New instrumentation is soon expected as regard electrochemical detection in capillary electrophoresis. Actually, in order to increase the responses and improve the selectivity, solid electrodes are facing exponential research dedicated to surface modifications. Perm-selectivity, chelations catalysis, etc. may be considered as appropriate strategies. Microelectrodes and screen printed (disposable) sensors are of considerable interest in cell culture e.g. for single cell excretion analysis and in field (decentralized) assays, respectively. Finally several biosensors and electrochemical immunoassays have been successfully development for the selective and sensitive analysis of drugs.

Automation↗

PubMed1996

Polarographic behavior of kojic acid and its derivatives, determination of potential carcinogenicity and correlation of these properties with their other attributes.

Polarographic properties of kojic acid [5-hydroxy-2-(hydroxymethyl)-4H-pyran-4-one] and 10 of their synthetic derivatives were investigated. It was shown that these compounds are reduced in anhydrous conditions, usually in one two-electron step or in two one-electron steps. The presence of some substituents may change the course of reduction process. The polarography of these compounds in the presence of alpha-lipoic acid showed the kojic acid analog-alpha-lipoic acid complex formation. The determined potential carcinogenic activity of these compounds expressed as a parameter tg alpha is not substantial.

Carcinogenicity Tests↗

PubMed1977

Evaluation of rapid polarographic method for determining tocopherols in vegetable oils and oil-based products.

A polarographic procedure for the determination of the tocopherols in vegetable oils was compared to a conventional gas-liquid chromatographic procedure. The polarographic method is 2-3 times more precise and more rapid, which is an important advantage for monitoring the nutritional value of processing conditions of vegetable oil-based products. Attempts to establish the validity of apparently slightly higher values for alpha- and gamma-tocopherols obtained by polarography has implicated the gas chromatography or derivative formation rather than the extensive prior manipulation of the sample for chromatography as the source of error. Essentially the same results were obtained for alpha-tocopherol, regardless of the technique used. However, more variable results which were product dependent were obtained for gamma- and delta-tocopherols when gas-liquid chromatography was used.

Chromatography, Gas↗

PubMedDate not supplied

Electrochemical studies of some quinolone antibiotics. Part I. Qualitative analysis on mercury and carbon electrodes.

Direct current polarography and cyclic voltammetry was used to study quinolone antibiotics: ciprofloxacin, enoxacin, norfloxacin, ofloxacin and pefloxacin on a mercury and carbon electrode. The dependence of limiting currents and half-wave potentials on the pH of the solution, mercury head, temperature, ionic strength of the solution, methyl cellulose concentration, scan rate and quinolone concentration was studied. The optimal parameters and background solutions have been chosen. It was concluded that on mercury electrode quinolones are reduced in two one-electron waves and the process of the reduction is accompanied by an acid-base equilibrium. An anodic peak observed on graphite electrode is probably caused by the oxidation of piperazine ring in the molecule.

Anti-Infective Agents↗

PubMed1977

Polarographic determination of robenidine residues in chicken tissues, eggs, litter, soil, and plant tissue.

Polarographic residue methods have been developed for determining robenidine (Robenz), 1,3-bis[p-chlorobenzylidene)amino]-guanidine monohydrochloride, in chicken tissues, eggs, litter, soil, and plants. The compound is extracted from chicken fat, skin, muscle, liver, and eggs with ethyl acetate; from blood with acetone; from plant tissue, litter, and kidney with acidic acetone; and from soil with basic methanol. After extraction by high-speed blending or overnight shaking, the extract is cleaned up by evaporation, solvent partition and/or elution from CG-50 ion exchange resin. Robenidine is quantitated by differential cathode ray polarography, using acidic aqueous methanol or acetic acid (1+1) supporting electrolyte. Recoveries ranged from 64 to 125% with an average overall recovery of 90%. The validated sensitivity is 0.1 ppm for chicken tissues, soil, and plants, 0.01 ppm for eggs, and 1 ppm for litter.

Animals↗

PubMed1997

Polarographic testing of carcinogenicity of some chemotherapeutics.

This work is devoted to the study of polarographic reduction of three antibiotic compounds including adriamycin, chloramphenicol and erythromycin and of a synthetic antibacterial chemotherapeutic compound--5-nitrofurantoin. The polarographic reduction was performed in the strictly anhydrous N,N-dimethylformamide with or without alpha-lipoic acid (LA) by the means of DC polarography. The values of half-wave potentials E1/2 and parameter of potential carcinogenicity were determined for the all compounds. Adriamycin was reduced during the five-step process, other compounds were reduced in two steps. The presence of LA in a polarographic solution resulted in a new polarographic one-electron wave in the range of -1.120 V to -1.790 V vs. SCE possessing a diffuse and reversible character. Its height is linearly dependent on the LA concentration in solution. The highest parameter of potential carcinogenicity tg alpha was determined for adriamycin (0.575) which belongs among compounds classified by WHO as "probably carcinogenic to humans". The lowest determined value of parameter tg alpha belonged to 5-nitrofurantoin (0.290) which has not yet been included into the IARC classification.

Anti-Bacterial Agents↗