PubMed Health⌕ Search

Biomedical subjects

M Pourfarzaneh

Publications and source records attributed to M Pourfarzaneh.

11 recordsLinked to original sources
PubMed1983

Specific micro-radioimmunoassay for prednisolone in serum.

Use of an 125I radioimmunoassay involving antiserum coupled to magnetizable cellulose, after prednisolone-21-phosphate interference is removed by dichloromethane extraction at pH 7.4 and endogenous glucocorticoid interference is removed by selective chemical derivatization with Girard's Reagent T [(carboxymethyl)trimethylammonium chloride hydrazide], allows determination of prednisolone in 10 microL of serum. Results correlate well with those of an established liquid-chromatographic method for separating prednisolone from its metabolites.

Chromatography, Liquid↗
PubMed1982

Direct determination of phenobarbital in serum or plasma by polarization fluoroimmunoassay.

A polarization fluoroimmunoassay for the direct determination of phenobarbital in serum or plasma was developed, optimized, and validated. The drug was derivatized by the introduction of a p-amino function in the phenyl group to enable coupling to carrier protein (used to raise antiserum in sheep) and to fluorescein label. The assay required simply the mixing of prediluted sample, labeled drug, and antiserum, followed by a short incubation and measurement of fluorescence polarization. Normal reliability criteria were satisfied and there was good correlation with established chromatographic and radioimmunoassay methods. Nonseparation, nonisotopic immunoassays are inherently susceptible to sample interferences, but it was shown that the polarization fluoroimmunoassay was subject to inaccuracy only in the presence of markedly elevated levels of bilirubin (above 500 mumol/L), or with gross hemolysis or lipemia.

Antibodies↗
PubMed1982

Fluoroimmunoassay of digoxin in serum.

A heterogeneous (solid-phase separation) fluoroimmunoassay for digoxin in serum was developed employing antibodies coupled to magnetisable cellulose/iron oxide particles and a fluorescein-labelled digoxin derivative as tracer. Intrinsic fluorophores and other potentially interfering components of serum samples were reliably and completely removed at the separation and wash steps of the assay procedure which were facilitated by magnetic sedimentation. In order to attain adequate sensitivity (detection limit 0.2 micrograms/l (0.26 nmol/l) serum digoxin), a sample volume of 500 microliters was necessary. Assay results for patients' specimens correlated well with those obtained using established charcoal--separation (r = 0.96) and magnetisable solid-phase (r = 0.95) radioimmunoassays. The feasibility of a "stat" adaptation of the fluoroimmunoassay that involved only two standards (0.5 and 4 micrograms/l digoxin) was demonstrated. The stat method would be suitable for the assay of urgent or single specimens.

Antibody Specificity↗
PubMed1981

A two-site immunofluorometric assay for human placental lactogen.

A two-site immunofluorometric assay for human placental lactogen (HPL) in serum has been developed. Samples and standards are incubated for 10 min with an excess of sheep anti-HPL serum covalently coupled to particles of magnetisable cellulose. After sedimenting the particles and adsorbed hormone on a magnet the supernates are aspirated (or decanted) to waste. An excess of purified sheep anti-HPL immunoglobulin, labelled with fluorescein, is added and, after a further 20 min, the fluorescence remaining in the supernates, after sedimenting the particles, is inversely related to the initial concentration of HPL. Results correlate closely with those of an established radioimmunoassay (r = 0.92), within- and between-assay coefficients of variation are less than 10% and, employing a 200 microliter sample volume, the assay extends from a minimum detection limit of 0.02 mg/l throughout the entire range of values encountered in pregnancy to more than 10 mg/l.

Female↗
PubMed1981

Magnetisable solid-phase fluoroimmunoassay of human immunoglobulin G in serum.

A simple fluoroimmunoassay is described for the determination of immunoglobulin G (IgG) in serum. It employs IgG labelled with fluorescein and magnetisable polyacrolein/iron oxide particles covalently linked to goat anti-human IgG serum. Diluted patient sample or standard and fluorescein-labelled IgG are incubated for 30 min with solid-phase antibody, the antibody-bound and free antigen separated simply by means of a magnet and the fluorescence in the supernate (free fraction) determined, which directly reflects the IgG concentration of the standard or sample. Correlation studies with two other immunological methods showed good agreement.

Animals↗
PubMed1980

A direct fluoroimmunoassay for conjugated chenodeoxycholic acid using antibody coupling to magnetisable particles.

A novel solid phase fluoroimmunoassay for conjugated chenodeoxycholic acid has been developed employing an antiserum coupled to magnetisable cellulose particles and a chenodeoxycholyl glycinefluorescein thiocarbamyl ethylene diamine conjugate as the label. The data obtained from serum samples from 25 patients correlated closely (r = 0.99) with those obtained by radioimmunoassay. The assay is rapid (30 minutes), simple, and ideal for routine clinical purposes.

Cellulose↗
PubMed1980

Cortisol directly determined in serum by fluoroimmunoassay with magnetizable solid phase.

We developed a direct fluoroimmunoassay for cortisol in serum. This method involves cortisol labeled at the 3 position with fluorescein, and antibodies to cortisol coupled to magnetizable cellulose/iron oxide particles. Sodium salicylate is used as a blocking agent to prevent interference from endogenous binding proteins in serum. Serum sample and labeled cortisol are incubated with the antibody-coupled solid phase for 30 min. The solid phase is then separated and washed to remove free labeled cortisol and endogenous fluorophores of the sample. Finally we elute the antibody-bound fraction of the labeled cortisol into an alkaline methanolic medium and measure its fluorescence. The separation, wash, and elution steps are facilitated by magnetic sedimentation. The assay is sufficiently sensitive, specific, and reliable for routine use and correlates acceptably (r = 0.92) with an established radioimmunoassay. Precision (CV) ranged from 4 to 10% in experiments on three pooled sera; analytical recovery for sera supplemented with as much as 360 microgram of cortisol per liter was 91 to 109%.

Cross Reactions↗
PubMed1978

Solid-phase fluoroimmunoassay of human albumin in biological fluids.

A simple fluoroimmunoassay for the determination of albumin levels in serum, urine and cerebrospinal fluid is described. It employs magnetisable particles to which antibodies to human serum albumin are covalently linked, and albumin labelled with fluorescein. Equilibrium is reached within 30 min, when separation of the bound and free fractions of the labelled albumin is performed by precipitation of the particles either with a magnet or by centrifugation. Measurement of the fluorescence in the supernatant (the free fraction) reflects the albumin concentration of the standards or samples. Correlation studies with an automated immunoprecipitation technique show good agreement.

Acrolein↗