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Biomedical subjects

J B Kim

Publications and source records attributed to J B Kim.

At least 109 records · Page 6Linked to original sources
PubMed1989

Progesterone in saliva as an index of ovarian function.

Progesterone was assayed in samples of saliva collected daily throughout the menstrual cycle and correlated with corresponding daily concentrations of pregnanediol-3 alpha-glucuronide in early morning urine. Ovarian follicular growth was monitored on a daily basis with a real-time sector scanner. The concentrations of salivary progesterone shows a specific pattern with a mid-cycle rise and a peak in the luteal phase. The mean concentration in the follicular phase, as determined, was 40.4 pmol/l (range 15.3-110.7 pmol/l). It increased in the peri-ovulatory period to a peak of 201.1 pmol/l (range 46.4-289.8 pmol/l) 6 days following follicular rupture.

Adult↗
PubMed1987

Recent advances in chemiluminescence-based immunoassays for steroid hormones.

Several formats of solid-phase separation techniques for the measurement of steroids and urinary steroid conjugates using chemiluminescence as an end point are described. These formats include: (1) immunoadsorption of second antibodies directed against the first antibody on solid support; (2) specific immunoadsorbents consisting of primary antibodies covalently coupled to polymer beads; (3) second antibody coupled to a polymer containing magnetic particles. In these assays a steroid-chemiluminescent marker conjugate serves as the labelled ligand, and highly specific homologous monoclonal antibodies are used to provide optimal specificity and rigorous standardization. These techniques enabled the direct measurement of steroid glucuronides in diluted urine and of steroids in plasma.

Animals↗
PubMed1985

Chemiluminescence immunoassay of plasma progesterone, with progesterone-acridinium ester used as the labeled antigen.

This simple solid-phase chemiluminescence immunoassay for measurement of progesterone in extracts of venous plasma has sensitivity and precision similar to that of conventional radioimmunoassay with use of a tritiated antigen. The labeled antigen, 11 alpha-progesteryl-2-succinoyltyramine-4-(10-methyl)-acridini um-9-carboxylate, and a monoclonal antibody to progesterone-11 alpha-succinyl-bovine serum albumin are incubated with a 100-microL aliquot of plasma extract (equivalent to 20 microL of plasma) and 50 microL of a suspension of an IgG fraction of a donkey antiserum to mouse immunoglobulins, covalently attached to cellulose particles. After the antibody-binding reaction (60 min at 4 degrees C), 1 mL of phosphate buffer is added to each tube, the tubes are centrifuged (5 min, 1500 X g), and the supernatant fluid is aspirated. The washing step is repeated and diluted hydrochloric acid (50 mmol/L, 50 microL) is added to the pellet. Luminescence is initiated by oxidation with dilute sodium hydroxide/hydrogen peroxide. The signal is integrated over 10 s. The light yield is inversely proportional to the progesterone concentration in the standard or sample.

Acridines↗
PubMed1984

Actuarial analysis of the risk of undergoing repeat cardiac valve replacement.

One thousand five hundred ninety-eight patients who underwent cardiac valve replacement were reviewed. One hundred fifty-two patients (10 percent) required a second valve replacement. The indications for repeat valve replacement were prosthetic valve dysfunction in 53 patients (35 percent), development of a new valvular lesion in 46 patients (30 percent), simple closure of a perivalvular leak in 14 patients (9 percent), change of the valve poppet in 13 patients (8 percent), severe hemolysis or emboli in 21 patients (14 percent), and prosthetic valve endocarditis in 5 patients (3 percent). The mean preoperative New York Health Association functional class improved from 3 to 1.5 in the nonreoperated patients and from 2.9 to 1.8 in patients who underwent a second valve replacement. Similarly, the mean cardiac index improved from 2.5 to 2.9 and from 2.5 to 2.8 in nonreoperated and reoperated patients, respectively. The operative mortality rate was 14 percent in the nonreoperated patients and 16 percent at second operation in the reoperated patients. Using actuarial techniques, the risk of repeat valve replacement was 1 to 4 percent per year. Long-term survival was compared between groups. Using actuarial techniques, the estimated survival rates at 1, 5, and 10 years were 89 percent, 69 percent, and 52 percent, respectively in nonreoperated patients and 87 percent, 60 percent, and 37 percent in reoperated patients. This study has documented the excellent improvement in functional and hemodynamic state after second cardiac valve replacement. The operative mortality and long-term survival rates were similar to those of the nonreoperated patients. Patients having repeat cardiac valve replacement can expect good improvement in length and quality of life.

Actuarial Analysis↗
PubMed1984

The measurement of urinary LH, by a solid-phase chemiluminescence immunoassay.

Ovulation in women may be predicted or detected by a simple, solid-phase, chemiluminescence immunoassay for the measurement of urinary LH. An IgG fraction of a donkey antiserum to rabbit immunoglobulins is passively adsorbed to the walls of polystyrene tubes. Human chorionic gonadotrophin-succinyl-butyl-ethyl-isoluminol and a primary antibody (rabbit anti-human LH) is incubated with samples of early morning urine. After the binding reaction, the solution is removed by aspiration. The antibody-bound fraction is washed twice with buffer. Sodium hydroxide is added and the mixture incubated. After cooling, luminescence is initiated by oxidation of the label with microperoxidase/hydrogen peroxide and the signal integrated. The method has been evaluated in terms of sensitivity, within- and between-batch precision, bias and parallelism. The time interval between the peak day of LH in EMU and maximum follicular diameter during 38 menstrual cycles was -24 h (11%), O h (50%), + 24 h (28%) and + 48 h (11%).

Buffers↗
PubMed1984

Measurement of choriogonadotropin by chemiluminescence immunoassay and immunochemiluminometric assay: 1. Use of isoluminol derivatives.

We have developed immunoassays, monitored by the detection of chemiluminescence, for measuring choriogonadotropin in human urine. These methods involve the use of derivatives of isoluminol and include: (a) a labeled antigen with a second antibody covalently linked to polyacrylamide beads as the solid-phase reagent (i.e., solid-phase chemiluminescence immunoassay); and (b) an excess concentration of a specific antibody passively adsorbed onto the walls of polystyrene tubes and a labeled antibody of different specificity (i.e., two-site immunochemiluminometric assay). After the respective binding reactions, the solutions are aspirated, the antigen- or antibody-bound fractions are washed twice with 500 microL of buffer, sodium hydroxide (2 mol/L; 200 microL) is added, and the mixture is incubated for 60 min at 60 degrees C. After cooling, the label is oxidized with microperoxidase/hydrogen peroxide and the resulting chemiluminescence signal is measured for 10 s. We have evaluated the methods in terms of their sensitivity, precision, and clinical utility, and we compare results with values obtained by radioimmunoassay.

Body Temperature↗
PubMed1983

Multiple immunoassay: the simultaneous measurement of two urinary steroid glucuronides as an index of ovarian function.

Ovarian function in women may be monitored effectively by a simple, solid-phase, multiple immunoassay for the simultaneous measurement of estrone-3-glucuronide and pregnanediol-3 alpha-glucuronide in diluted urine. IgG fractions of the respective antisera are passively absorbed to the walls of polypropylene tubes. The labelled antigens are estrone-3-glucuronyl-5-aminoethyl-ethyl-isoluminol and [6,9-3H]-pregnanediol-3 alpha-glucuronide. Daily samples of early morning urine are diluted in buffer (1:200; v/v), and 200 microliters removed, in duplicate, for assay. After the binding reaction (18 h at 4 degrees C), the solution is removed by aspiration. The antibody-bound fraction is washed twice with buffer (300 microliters) is added and the mixture incubated for 50 min at 22 degrees C. Luminescence is initiated by oxidation of the label with microperoxidase/hydrogen peroxide and the signal integrated for 10 s. Subsequently, liquid scintillation fluid (4 ml) is added to the tube and the radioactivity measured. The unknown values are determined from appropriate calibration curves. The combined method has similar sensitivity, accuracy, precision and clinical utility to the values obtained from the separate measurement of the two analytes.

Antigen-Antibody Complex↗
PubMed1983

Measurement of serum thyroxine by solid-phase chemiluminescence immunoassay.

Descriptions are given of two solid-phase chemiluminescence immunoassays for the measurement of total thyroxine in serum. The antibodies were either attached to small uniform plastic microspheres (method 1) or passively adsorbed to antibody-coated tubes (method 2). The labelled antigen was thyroxine-aminobutyl ethyl isoluminol. After the antibody-binding reaction the antibody-bound fraction was washed, sodium hydroxide was added, and the mixture was incubated. Luminescence was initiated by oxidation of the label with microperoxidase/hydrogen peroxide and the signal integrated for 10 seconds. The light yield is inversely proportional to the concentration of thyroxine in the standard or sample. Both methods have similar sensitivity and precision to that obtained by a conventional radioimmunoassay.

Antibodies↗
PubMed1982

Measurement of plasma estradiol-17 beta by solid-phase chemiluminescence immunoassay.

We describe a simple, solid-phase chemiluminescence immunoassay for the measurement of estradiol-17 beta in extracts of peripheral venous plasma. The method has similar sensitivity, specificity, precision, and accuracy to a conventional radioimmunoassay with a tritiated antigen. An immunoglobulin G fraction od monoclonal antibodies to estradiol-6-carboyxmethyl oxime-bovine serum albumin is passively adsorbed onto the walls of polypropylene tubes. The labeled antigen is estradiol-6-carboxymethyl oxime-aminobutylethyl isoluminol. After the binding reaction (1 h at 22 degrees C), the solution is removed by aspiration (400 microliters). Sodium hydroxide (5 mol/L, 300 microliters) is added and the mixture incubated for 30 min at 37 degrees C. Luminescence is initiated by oxidation of the label with microperoxidase/hydrogen peroxide and the signal integrated for 10 s. The light yield is inversely proportional to the concentration of estradiol in the standard or sample.

Adult↗
PubMed1981

Evaluation of different progesterone-isoluminol conjugates for chemiluminescence immunoassay.

The effect of varying the length of the alkyl bridge linking the chemiluminescent label isoluminol to progesterone on the light yield and binding affinity of progesterone chemiluminescent-marker conjugates was investigated. For this purpose five different derivatives of isoluminol, aminoethyl isoluminol (AEI), aminoethylethyl isoluminol (AEEI), aminobutyl isoluminol (ABI), aminobutyl-ethyl isoluminol (ABEI) and aminoethyl-ethyl isoluminol (AHEI) were covalently linked through a peptide bond to progesterone-11 alpha -hemisuccinate (P-11-HS). The resulting progesterone chemiluminescent-marker conjugates were then evaluated as potential labels for the development of an immunoassay based on monitoring chemiluminescence. These conjugates were able to compete with tritiated progesterone for the binding sites of an antibody raised against progesterone-11 alpha-HS bovine serum albumin, and they showed higher affinity than unaltered progesterone. These conjugates produced light upon oxidation by a hydrogen peroxide-microperoxidase system. The chemiluminescent reaction was optimized in terms of pH, concentration of oxidant, catalyst and conjugate design. Under optimal conditions, all the conjugates were detectable at femtomolar levels. The lowest detection limit was obtained using P-11-HS-ABEI (0.1 fmol). These results indicated that immunoassay techniques based on chemiluminescence can be developed with these labels.

Animals↗
PubMed1981

Luminescent immunoassay (LIA) for progesterone in a heterogeneous system.

An immunoassay procedure for determination of progesterone in human plasma is described which utilizes chemiluminescence as the endpoint. The assay utilized progesterone-11-hemisuccinate-aminobutyl-ethyl-isoluminol (P-11-HS-ABEI) as the chemiluminescent marker conjugate and dextran coated charcoal for the separation of bound and free fractions of the ligand. An assay procedure for progesterone was established and validated in terms of sensitivity and precision, and assay results were compared with radioimmunoassay, using tritiated progesterone as the tracer. The two methods agreed well (n=35, r=0.96). The most important advantage of this assay is the elimination of problems inherent in the use of radioactive materials.

Azides↗