Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.11.1.7 (peroxidase)
 65,474 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The radioreceptor assay system for TSH is considered to be useful in quantitating the hormone and analyzing the mechanism of its action. The assay was established, and the interaction of abnormal thyroid stimulators in Graves' patients was evaluated in this assay system. A 10,000xg fraction of human thyroid homogenates was used as the receptor. Human TSH supplied from NIH was iodinated by using lactoperoxidase. The binding of 125I-TSH to the receptor was small, and 125I-TSH was further purified by the receptor binding. The receptor (25mg equivalent), purified 125I-TSH, and standard TSH or a sample were incubated at 37 degrees C for 60 min in a final volume of 300 microliters. The binding of 125I-TSH to the receptor was time- and temperature-dependent with optimal binding under the conditions described above. The binding was completely inhibited by the addition of human, bovine and ovine TSH and partially inhibited by high concentrations of HCG, FSH-LH. However, there was no cross reactivity with insulin, prostaglandin E1, E2, T3, T4 and Nal. The assay was sensitive enough to detect 5 to 50 microU of TSH. The amount of TSH bound to the receptor was almost parallel to the TSH concentration which is necessary to stimulate human thyroid adenylate cyclase activity. Studies of dissociation kinetics and Scatchard plot indicated that there were two classes of TSH receptors in the human thyroid. A higher association constant was calculated as 1.5 x 10(8)M-1. LATS-IgG from a patient with Graves' disease completely inhibited the binding of 125I-TSH to the receptor, and studies of Lineweaver-Burk, plot suggested that TSH and LATS-IgG shared common binding sites. The radioreceptor assay of TSH appears to be useful in evaluating the abnormal thyroid stimulators present in Graves' disease.
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PMID:[Studies on the radioreceptor assay of TSH: the binding of 125I-TSH to the human thyroid receptor and the interaction of LATS-IgG (author's transl)]. 22 97

An enzyme-immunoassay (EIA) for estimation of human placental lactogen (HPL) in plasma or serum was developed using HPL labelled with horseradish peroxidase (HRP) and anti-HPL sera raised in rabbits. The separation between antiserum-bound and free labelled hormone was accomplished with a double antibody solid phase technique. Interference of substances from the sample with the immunoassay was prevented by dilution of the sample with at least a factor of 20 and measurement of the labelled hormone attached to the solid phase. The peroxidase activity was colorimetrically measured using o-phenyl-enediamine and urea peroxide as substrate. The standard curve of the assay ranged from 3 to 40 ng HPL/ml allowing estimations of HPL in serum or plasma starting from about the 10th week of pregnancy. Normal values were established. Intra- and inter-assay variation coefficients of 6 and 7.5% respectively were found. The EIA showed no cross-reaction with human serum proteins or HCG. The low cross-reaction noted with human growth hormone did not interfere with the assay. An excellent agreement was found with the results of radioimmunoassay (RAI).
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PMID:Enzyme-immunoassay of human placental lactogen. 36 37

Serial transplantation of an HCG-producing human testicular teratoma in immune-deprived mice is described. The xenografted tumour was compared to the tumour of origin in histology, immunohistochemistry (using an immune peroxidase technique to localize HCG) autoradiography, marker production and growth rate. It is concluded that the xenograft retained the characteristics of the original tumour with the exception of a reduction in HCG-producing elements at transplantation beyond 5 serial passages.
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PMID:A human testicular teratoma serially transplanted in immune-deprived mice. 38 30

The onset of FSH synthesis in the embryonic pituitary gland of the rat was studied by a peroxidase-labelled antibody method. The first FSH-containing cells appeared on the 20th day of embryonic life. From that day onwards, FSH cells increased rapidly in number. It was found that in adult animals some pituitary cells reacted with both anti-HCG and anti-FSH sera, indicating the simultaneous presence of LH and FSH in the same cell.
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PMID:Functional differentiation of the FSH-synthesizing cells in the pars distalis of the fetal pituitary gland of the rat. 79 82

A cross-reaction of anti-HCG and anti-HPL sera with related tissue antigens in normal beagle dog pregnant uteri, from thirty days of pregnancy to term, is reported. Using the immunoglobulin-peroxidase bridge technique, specific staining is localized in the glands of the spongy layer and in the deep uterine glands, but it is absent from the trophoblasts of the placental labyrinth. A specific reaction product is also observed in the surface and glandular epithelium of the chorion laeve. These findings suggest that certain antigens, which share antigenic determinants with HCG and HPL, are produced in the endometrial epithelium and not in the trophoblastic villi of pregnant beagle dogs.
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PMID:Immunohistological localization of antigens related to human chorionic gonadotrophin and human placental lactogen in the uterus of pregnant beagle dogs. 117 2

Patients with testis tumor were investigated for serum and tissue levels of alpha-fetoprotein and beta-human chorionic gonadotropin (beta-HCG). The tissue immune peroxidase-antiperoxidase staining for the tumor marker was quantitated by computer-assisted immunohistophotometry and immuno-gamma ray histospectrometry. The results supported the general view that mostly polynuclear giant cells produce beta-HCG in 66% of nonseminoma cancer. This finding qualifies beta-HCG as relatively unspecific in the absence of chorioepithelial cells in the tumor. Discrepancies of tissue and serum beta-HCG values may be caused by deglycolysation of beta-HCG while penetrating the perivascular tissues. Alpha-fetoprotein (AFP) appears helpfully to discriminate the true seminoma cancer, which is constantly negative. Histologically pure seminoma which reacts for AFP therefore suggests sclerotic teratoma compartments. A constant finding is the significantly reduced synthesis rate of tumor markers in metastasis compared to primary tumor.
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PMID:Quantification of alpha-fetoprotein and beta-HCG in testis tumor patients. 244 89

The area and cytoplasmic-to-nuclear ratio (C/N) of cells aspirated from follicles with mature oocytes was determined using a computerized image analysis system. The presence of human chorionic gonadotropin (hCG) on the surface membrane and/or within the cytoplasm of each cell also was determined using a horseradish peroxidase immunocytochemical procedure. Based on morphometric characteristics, follicular cells were classified as granulosa or luteal. Granulosa cells were less than 75 micron 2 in area with a C/N of approximately 0.5. Luteal cells were classified as small (less than 75 micron 2, C/N approximately 1.5), midluteal (76 to 100 micron 2, C/N greater than 1.5) and large luteal (greater than 100 micron 2, C/N greater than 1.5). Compared with aspirates from follicles containing fertilizable oocytes, aspirates from follicles with nonfertilizable oocytes had fewer granulosa cells and more large luteal cells. HCG was localized on the membranes of granulosa and small luteal cells and within the cytoplasm of midluteal cells. Human chorionic gonadotropin was generally not observed on either the membranes or cytoplasm of luteal cells over 120 micron 2. These data support the concept that granulosa cells bind hCG to membrane receptors, internalize hCG, and begin to luteinize in response to hCG stimulation. Since the aspirates from follicles containing nonfertilizable oocytes possessed a higher percentage of large luteal cells, it is postulated that the cells from these aspirates began the luteinization process earlier than those from follicles containing fertilizable oocytes.
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PMID:Human chorionic gonadotropin localization and morphometric characterization of human granulosa-luteal cells obtained during in vitro fertilization cycles. 264 58

38 pure and 11 mixed seminomas were studied with the peroxidase-anti-peroxidase method for the presence of chorionic gonadotropin (beta-HCG) and pregnancy-specific beta 1-glycoprotein (SP1). HCG was found in 8 of 49 cases, SP1 in 5 of 49 cases in syncytial and mononuclear giant cells. The 5 pure seminomas with positive tumor markers appear to have no worse prognosis than pure seminomas without HCG or SP1 production. None of the seminomas was found to contain carcinoembryonic antigen or alpha-fetoprotein.
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PMID:Immunohistochemical and radioimmunological determination of beta-HCG and pregnancy-specific beta 1-protein in seminomas. 388 14

A detailed follow-up examination was performed in 20 patients who had been operated upon 10 to 20 years ago because of uni- or bilateral cryptorchidism. The youngest patient was 18 years old at the time of the follow-up. The following values were analysed: primary and secondary sexual characteristics, the possible sexual disturbances, penile volume and the diameter of the testes, the serum testosterone, HCG, FSH, and LH level, sperm and immune peroxidase examination, and histologic study of both testes. The absence of sexual disturbances and the normal primary and secondary sexual characteristics were explained by the results of hormonal assays and these also showed that in adults there is no possibility to improve fertility by hormones. Early operation at 2 years of age at the latest is the only possibility to prevent in- or subfertility. The intervention prevents secondary damage to the retained and to the contralateral testicle. Immune peroxidase tests pointed to the possibility of therapy by immunosuppressive drugs.
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PMID:Follow-up examination of patients with undescended testicles. 611 9

We evaluated a quantitative solid-phase enzyme immunoassay for human choriogonadotropin beta subunit (beta-HCG) with anti-beta-HCG:horseradish peroxidase conjugate, recently marketed by Abbott Laboratories. We compared results on 56 patients' serum specimens, obtained mostly for followup of neoplastic disease, with those by a competitive radioimmunoassay kit. The correlation was good, the differences being of little clinical significance. Linear regression in the low and intermediate ranges gave a slope of 0.93, a y-intercept of 0.34, and a correlation coefficient of 0.97. Precision studies yielded an interassay CV of 6.4% in the intermediate range and 13% in the low range. Sensitivity was 0.69 int. unit/L. Cross reactivity was 1 to 2% with specimens fortified with lutropin or follitropin. The only substantial problem was with linearity in the upper part of the standard curve, especially in the interval, 100-200 int. units/L. This problem is obviated by adequate sample dilution.
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PMID:Evaluation of a solid-phase enzyme immunoassay for human choriogonadotropin beta subunit. 619 17


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