Radioreceptor Assay of Human Chorionic Gonadotropin: Detection of Early Pregnancy

Saxena, Brij B.; Hasan, S. H.; Haour, F.; Schmidt-Gollwitzer, M.

doi:10.1126/science.184.4138.793

Cited by 136 publications

(20 citation statements)

References 14 publications

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“…hCG (CR-119) showed 1.4% and 9.0% crossreactivity in the homologous RIA for hCGa and hCGf3, respectively. RRA was performed by the method described by Saxena et al (11), using plasma membranes of bovine corpus luteum. The membranes were generously supplied by Wampole Laboratories.…”

Section: Materials and Methods Bacterial Extracts A Microorganism Tementioning

confidence: 99%

Production of choriogonadotropin-like factor by a microorganism.

Maruo¹,

Cohen²,

Segal³

et al. 1979

Proc. Natl. Acad. Sci. U.S.A.

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Extracts from an acetone powder preparation of a culture of a microorganism tentatively named Progenitor cryptocides contain choriogonadotropin (CG-like factor as determined by radioimmunoassay with antiserum to human (h)CG # subunit COOH-terminal peptide and radioreceptor assay with bovine corpus luteum membranes. Possible interference by proteases in the extracts was excluded. Immunoreactive materials reacting with antisera to hCG 0 subunit and hCG P subunit COOH-terminal peptide were also found in the extracts. No free a subunit was detected. The CClike factor was purified by chromatography on Sephadex G-100, concanavalin A-Sepharose, and DEAE-Sephadex A-50. The factor was adsorbed by concanavalin A-Sepharose, suggesting that it contains mannose and glucose moieties. The factor was eluted at the same position as standard hCG on Sephadex G-100. It dissociated into two bands when subjected to sodium dodecyl sulfate/polyacrylamide gel electrophoresis; the bands corresponded to the respective standard hCG subunits. The biological activity of the purified factor as determined by the rat uterine weight assay and the ovarian weight assay was equivalent to 380 (95% confidence limits: 320-490) and 880 (780-1020) international units/mg, respectively. It can be concluded from the present results that a microorganism produces a glycoprotein that is biologically active and has physicochemical properties similar to those of hCG.Human (h-) choriogonadotropin (CG) is a glycoprotein hormone normally produced by the placenta and considered to be a specific hormone of pregnancy and trophoblastic neoplasms. However, it has been reported that nontrophoblastic malignant tumors (1, 2) and normal human tissues (3) produce CG Related to the problem of extraplacental production of CG, there are reports suggesting that CG is produced by a microorganism (5, 6). However, in the measurements in these studies, possible interference by proteases in the bacterial extracts was not excluded. In the present study, we will show that a CG-like factor is produced by a microorganism and that the observed results are not due to proteases. The factor has been purified and found to be biologically active, and it has immunological and physicochemical properties similar to those of hCG. MATERIALS AND METHODS Bacterial Extracts. A microorganism tentatively namedProgenitor cryptocides was obtained from V. W.-C. Livingston (5). Cultures of the microorganism were maintained on Muller-Hinton slants. Inoculation of 250 ml of trypticase/yeast extract medium in a 500 ml Erlenmeyer-flask was performed with a single colony from the Muller-Hinton slant. To a 28-liter fermenter, 20 liters of trypticase/yeast extract medium was added and the fermenter was inoculated with an overnight growth of the organism in the 250 ml of medium described above. After incubation for 120 hr at 37°C, the entire culture content was harvested and an acetone-dried powder was prepared according to a prescribed method (5), by J. Majnarich, Biomedical Research Laboratory. Twenty ...

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Section: Materials and Methods Bacterial Extracts A Microorganism Tementioning

confidence: 99%

Production of choriogonadotropin-like factor by a microorganism.

Maruo¹,

Cohen²,

Segal³

et al. 1979

Proc. Natl. Acad. Sci. U.S.A.

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“…When we attempted to apply the RRA method to the assay of serum samples, nonspecific interference by the serum was a serious problem. Saxena et al (1974) reported a RRA system for measuring the serum LH and hCG using bovine corpora lutea as the receptor preparation, but they mentioned nothing about the nonspecific interference by serum. In our preliminary experiments, a potent nonspecific interference with the binding of 125I-LH to the receptor preparation was demonstrated in the monkey serum, resulting in a flattening of the standard curve.…”

Section: Discussionmentioning

confidence: 99%

Radioreceptor assay for cynomolgus monkey serum luteinizing hormone.

et al. 1984

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“…Human chorionic gonadotropin (choriogonadotropin) (HCG) is a product of trophoblasts and is synthesized at a very early stage of pregnancy, i.e., within [6][7][8] days of the fertilization of the egg (1). It provides a critical support to the corpus luteum, which decays in its absence, resulting in menstruation.…”

mentioning

confidence: 99%

Isoimmunization against human chorionic gonadotropin with conjugates of processed beta-subunit of the hormone and tetanus toxoid.

Talwar¹,

Sharma²,

Dubey³

et al. 1976

Proc. Natl. Acad. Sci. U.S.A.

153

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The immunogenicity of the conjugate prepared from "processed" a-subunit of human chorionic gonadotropin (choriogonadotropin, HCG) and tetanus toxoid has been studied in animals and a human subject. The conjugate elicited the formation of high-affinity (Ka = 109-101' M-') anti-HCG and anti-tetanus antibodies. On primary immunization, the antibody response lasted for several months. Repeat injection of the conjugate in the declining phase of antibody titers produced a booster response without a lag period. The antibodies reacted with the ,8-subunit of HCG and the complete HCG molecule but were devoid of significant crossreactivity with human growth hormone, placental lactogen, follicle-stimulating hormone, thyroid-stimulating hormone, and luteinizing hormone at tonic and surge levels. The antibodies were competent for neutralizing the biological activity of HCG in the mouse uterine weight gain assay, the ventral prostate weight gain assay, and the radioligand assay for binding of 1251-labeled HCG to receptors on corpus luteum. HCG (5000 international units) administered to an immunized subject was completely bound by circulating antibodies. Administration of HCG (in contrast to conjugate) was without booster effect on anti-HCG titers.

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Radioreceptor Assay of Human Chorionic Gonadotropin: Detection of Early Pregnancy

Cited by 136 publications

References 14 publications

Production of choriogonadotropin-like factor by a microorganism.

Production of choriogonadotropin-like factor by a microorganism.

Radioreceptor assay for cynomolgus monkey serum luteinizing hormone.

Isoimmunization against human chorionic gonadotropin with conjugates of processed beta-subunit of the hormone and tetanus toxoid.

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