@article{oai:niigata-u.repo.nii.ac.jp:00006664,
 author = {Sato, Yoshiaki and Sudo, Yuhetsu and Takeuchi, Shoshichi},
 issue = {2},
 journal = {Acta medica et biologica, Acta medica et biologica},
 month = {Oct},
 note = {We developed an assay that measures human chorionic gonadotropin (hCG) at levels as low as 0.2 mIU/ml and that is roughly 25 and 10 times as sensitive as the hemagglutination (5 mIU/ml) and β-hCG radioimmunoassay (2 mIU/ml) methods, respectively. Cross-reaction in this assay system with human luteinizing hormones, human follicle-stimulating hormones, human thyroid-stimulating hormones, and α-hCG was very low; however, human menopausal gonadotropin showed a 4% crossreaction. In normal women, the hCG secretion tended to increase with age; the maximum value was 3.2 mIU/ml. This method is useful for long-term follow-up of trophoblastic diseases and early detection of recurrent choriocarcinomas. Human chorionic gonadotropin (hCG) is a glycoprotein hormone secreted by trophoblastic cells. As trophoblastic tumors also secrete hCG, it is regarded as a valuable tumor marker in trophoblastic disease. This hormone has α- and β-subunit which are biologically inactive as free subunits. The α-subunits of the hCG, the luteinzing hormone (LH), the follicle-stimulating hormone (FSH), and the tyroid-stimulating hormone are nearly identical, but the amino acid sequences of the β-subunits differ and account for the unique immunologic and biologic activities of each glycoprotein hormone. Nevertheless, the α-subunits of the 4 hormones have considerable homology, especially hCG and LH, which are similar in biologic activity. The β-subunits of hCG, however, contains an additional unique CTP of 30 amino acids that is absent in LH. The production of antiserum against the hormone-specific β-subunit, which possesses a greater affinity for hCG than for LH, has enabled us to develop the hCG assay that is more specific at low concentrations. This report compares the efficacy of the hCG RIA and this newly developed enzyme immunoassay (EIA) in measuring serum hCG activity in patients with molar pregnancies and choriocarcinomas.},
 pages = {85--94},
 title = {A newly developed enzyme immunoassay for the detection of human chorionic gonadotropin and its significance in the follow-up of trophoblastic disease},
 volume = {36},
 year = {1988}
}