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Biomedical subjects

R C Boguslaski

Publications and source records attributed to R C Boguslaski.

At least 19 recordsLinked to original sources
PubMed1979

The combined radioimmunoassay of triiodothyronine and thyroxine.

An RIA method for the concurrent determination of serum triiodothyronine (T3) and thyroxine (T4) is described. The extraction of the hormones from serum and competitive binding reactions using specific T3 and T4 antisera were conducted in sequence in a single Sephadex column. Precision studies resulted in average interassay relative standard deviations for T3 and T4 of 17 and 9.5%, respectively. The assay also exhibited satisfactory recovery and correlation with reference procedures (T3: y = 0.84x -- 36, r = 0.98; T4: y = 0.96x + 0.06, r = 0.98, where y is the value obtained by the combined method and x is the value obtained by the reference method.

Binding, Competitive↗
PubMed1979

Immunoassay for serum thyroxine monitored by chemiluminescence.

An immunoassay for thyroxine (T4) monitored by chemiluminescence was evaluated with clinical serums. A thyroxine-label conjugate (T4-L) and serum samples were applied sequentially to alkaline Sephadex G-25 columns which adsorbed the thyroxine species. Other serum components and potential interferents were washed from the column with barbital buffer. Subsequently addition of antibody initiated the binding reaction. After 1 h incubation, the antibody was eluted from the column with a barbital buffer wash. The bound T4-L in the eluate was oxidized in a chemiluminescent detection reaction. The peak light intensity, attained in about 1 sec, was related to T4 concentration by means of standards. The intra-assay precision of the chemiluminescence immunoassay was +/-5% (C.V.). Statistical comparison of T4 levels determined for 28 serums by this method and a reference assay was acceptable (y = 0.95x + 5.9, r = 0.98, Sy square root of y . 100 = 13.1%).

Chromatography, Gel↗
PubMed1979

Substrate-labeled fluorescent immunoassay for phenytoin in human serum.

A homogeneous substrate-labeled fluorescent immunoassay has been applied to the measurement of phenytoin concentrations in human serum. We coupled a fluorogenic enzyme substrate, galactosyl-umbelliferone, covalently to a derivative of phenytoin. Under assay conditions, this drug-substrate conjugate was nonfluorescent but became fluorescent upon hydrolysis catalyzed by bacterial beta-galactosidase. When antibody to phenytoin is bound to the drug-substrate conjugate, it is inactive as an enzyme substrate. Addition of phenytoin to competitive-binding reactions relieves the inactivation, and the resulting fluorescence is proportional to the phenytoin concentration. We validated the fluorescent immunoassay by comparing values for phenytoin obtained with this technique to those obtained by gas chromatography and by enzyme immunoassay (EMIT). All three methods correlated well. The major metabolite of phenytoin, 5-(p-hydroxyphenyl)-5-phenylhydantoin, and other drugs at concentrations expected in serum had no effect on the assay. The fluorescent immunoassay is rapid and simple to perform and requires only 2 microL of serum sample per test.

Chromatography, Gas↗
PubMed1977

Isolation of substances from urine by affinity chromatography.

The applications of affinity chromatography for the isolation and purification of physiological substances from urine have been reviewed. The use of affinity supports for the detection and measurement of various urinary components has also been briefly examined. These examples illustrate the usefulness of urine as a source of fine reagents and the versatility, simplicity and practicality of affinity isolation procedures.

Animals↗
PubMed1977

Homogeneous reactant-labeled fluorescent immunoassay for therapeutic drugs exemplified by gentamicin determination in human serum.

We applied a homogeneous reactant-labeled fluorescent immunoassay to the measurement of therapeutic drug concentrations in human serum, exemplified here by gentamicin. A derivative of umbelliferyl-beta-galactoside was coupled covalently to the drug and this conjugate was found to be nonfluorescent under assay conditions. The drug/dye conjugate was a substrate for bacterial beta-galactosidase and yielded a fluorescent product. When the drug/dye conjugate was bound to anti-gentamicin antibody it was inactive as an enzymatic substrate. This inactivation was relieved by the presence of gentamicin in competitive binding reactions. Hence, the rate of production of fluorescence was proportional to the gentamicin concentration. The fluorescent assay yielded values which compared favorably to a radioimmunoassay for gentamicin in clinical serum samples (r=0.94, standard error of estimate=0.66 mg/liter). The fluorescent assay requires only 1 microliter of serum and offers several advantages over existing techniques: sensitivity, specificity, simplicity, and the obviation of radioisotopes.

Cross Reactions↗
PubMed1977

Maternal serum unconjugated estriol and urine estriol concentrations in normal and high-risk pregnancy.

Serum unconjugated estriol levels and urinary estriol levels of concurrent specimens were compared for 6 normal and 6 high-risk subjects throughout the last trimester of pregnancy. Free estriol values in serum exhibited a close correlation with urinary estriol values for both the normal (r = 0.91) and high-risk (r = 0.92) groups. The results of this study indicate that the assessment of high-risk pregnancies now accomplished principally by urinary estriol assays may be performed by more convenient and rapid radioimmunoassays developed for quantification of free estriol in serum.

Estriol↗
PubMed1975

A column radioassay for the quantification of vitamin B-12.

A rapid and convenient column radioassay for the quantification of vitamin B-12 in clinical specimens has been developed. A mixture of the specimen and radiolabeled B-12 was applied to a column containing immobilized intrinsic factor and allowed to incubate for two hours. A buffer wash then separated bound and free B-12. The average intra- and inter-assay coefficients of variation over the range of interest was about 30 pg/ml in the sample and recovery and parallelism studies gave satisfactory results. The values obtained for clinical specimens by the column procedure correlated well with those obtained by reference method.

Binding Sites↗