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PubMed1981

Pregnancy-specific beta 1 glycoprotein and chorionic gonadotrophin levels following conception.

Levels of pregnancy-specific beta 1 glycoprotein (SP1) and beta-subunit human chorionic gonadotropin (beta-hCG) were measured in the plasma of 22 subjects in early pregnancy following spontaneous or induced ovulation. Minimum baseline levels for pregnancy detection were set at 4 microgram/liter for SP1 an 15 IU/liter for beta-hCG. Using these levels, in some cases SP1 was detectable by day 17 following ovulation and beta-hCG by day 13. All patients were diagnosed as pregnant by day 20 using SP1 and by day 18 using beta-hCG. Both placental proteins had similar doubling times in the plasma. These was no difference between pregnancies following spontaneous and induced ovulation. Until accurate normal ranges can be obtained, there will be problems of interpretation of levels near the limits of the sensitivities of the assay in clinical situations.

Chorionic Gonadotropin↗

PubMed1993

Abbott AxSYM random and continuous access immunoassay system for improved workflow in the clinical laboratory.

We describe a new clinical laboratory instrument, the Abbott AxSYM, which provides random- and continuous-access testing for immunoassays, 20 onboard reagents, primary tube sampling, and a throughput of 80 to 120 tests per hour. The AxSYM incorporates three separate analytical technologies for processing immunoassays: microparticle enzyme immunoassay, fluorescence polarization immunoassay, and a novel technology known as ion-capture immunoassay. The system incorporates both common and technology-specific subsystems controlled by a real-time software scheduling processor. Tests can be processed in one- or two-step sandwich or competitive formats, with variable pipetting steps, incubation periods, optical read formats, and wash sequences. Menu capabilities include tests for hepatitis, retrovirus, tumor markers, fertility markers, thyroid functions, and therapeutic drugs. The time to first result is approximately 15-25 min for most routine assays and < or = 15 min for stat assays (i.e., creatine kinase MB isoenzyme, human chorionic gonadotropin beta subunit, and therapeutic drugs). AxSYM assay performance for 23 assays was comparable with that of the Abbott IMx and TDx analyzers; specimen correlation data had correlation coefficients ranging from 0.97 to 0.99 and slopes ranging from 0.99 to 1.10. Within-run imprecision (CV) was 1.5% to 11.4%, with most assays (19 of 23) demonstrating CVs < or = 8.0%.

Autoanalysis↗

PubMed1988

Urinary gonadotropin fragments (UGF) in cancers of the female reproductive system. II. Initial serial studies.

Levels of UGF, which constitute the free beta-subunit of human chorionic gonadotropin, asialo free beta-subunit, and a core fragment of asialo free beta-subunit, detected by a single immunoradiometric assay, were monitored in the urines of 28 woman undergoing therapy for gynecologic cancer (3 cervical, 8 endometrial, and 17 ovarian). During a 7-month study, 24 of the 28 woman had elevated UGF levels (greater than 0.2 ng/ml). Correlation was observed of UGF levels and changing clinical status during therapy in 23 of these 24. Normal range CA 125 (less than 35 U/ml) was found throughout the study period in 4 of 14 woman undergoing therapy for serous ovarian malignancy. Three of the 4 had elevated UGF levels which accurately followed the course of their disease. These preliminary studies suggest that in monitoring therapy of gynecologic cancers UGF, alone or with CA 125, warrants evaluation.

Calcium↗

PubMed1992

Search for peptide immunogens of the beta-subunit of human chorionic gonadotropin (hCG) capable of eliciting hormone specific and neutralizing antisera. Identification of an undecapeptide eliciting hCG-specific antisera.

The work reported herein describes our attempts to identify peptide immunogens of the beta-subunit of the pregnancy-specific placental hormone, human chorionic gonadotropin (hCG), capable of eliciting hormone specific and neutralizing antisera. Hydrophilicity profiles of the beta-subunits of hCG and the homologous pituitary hormone, human luteinizing hormone (hLH) were compared and two sequences which are hydrophilic but unique to hCG-beta were identified. They are 6-12 and 109-119 of hCG-beta. Results of the studies with the undecapeptide 109-119 of hCG-beta are reported in this paper. The undecapeptide amide was synthesized using the p-(acyloxy) benzhydrylamine resin and antisera to the peptide were elicited in rabbits using the peptide-diphtheria toxoid conjugate. The peptide is highly immunogenic as both the rabbits responded with high titers of antibodies to the peptide. The antipeptide antibodies bound to hCG but not to hLH showing thereby that the region 109-119 of hCG-beta is a unique determinant of hCG. However, the antibodies were found not to neutralize the biological activity of hCG.

Amino Acid Sequence↗

PubMed1992

Over-expression and characterization of recombinant beta subunit of the human chorionic gonadotropin hormone synthesized in insect cells infected with a genetically engineered baculovirus.

A recombinant baculovirus, vAc beta hCG, having a replacement of the viral polyhedrin gene with the cDNA encoding the beta subunit of hCG was used to express beta hCG, an extensively glycosylated hormone, in insect cells. Virus-infected cells, 72 hr pi, secreted approximately 8.02 micrograms beta hCG/2 x 10(6) cells/ml. The recombinant beta hCG purified from insect cells exhibited increased mobility on SDS-PAGE as compared to authentic urinary beta hCG, a reflection on differences in glycosylation between insect and mammalian systems. The insect derived beta hCG, however, was identical to the native hormonal peptide in terms of immunoreactivity and bioactivity on association with alpha-subunit, as evident by its binding to rat testicular receptors and induction of steroidogenesis in a mouse Leydig cell bioassay system. The implications of using the baculovirus system to study the importance of carbohydrates for biological activity are also discussed.

Animals↗

PubMed1980

Ectopic secretion of complete human chorionic gonadotropin and beta-subunit by human cervical carcinoma cells lines.

The CaSki and DoT cervical cancer cell lines were reported to secrete the beta-subunit of hCG in the absence of complete hCG or alpha-subunit (Science 196: 1456, 1977; J Clin Endocrinol Metab 46: 69, 1978). In the present study, concentrates of fluids from large numbers of CaSki or DoT cultures were analyzed for the presence of hCG beta and complete hCG. Although some CaSki and DoT preparations contained no detectable complete hCG, others were found to contain as much as 18% hCG. The reason for the variation in the amount of hCG relative to hCG beta in CaSki and DoT cultures is unknown.

Cell Line↗

PubMedDate not supplied

Characterization of monoclonal antibodies recognizing alpha and beta subunits of human chorionic gonadotropin hormone.

Human chorionic gonadotropin (hCG) hormone is required for maintenance of early pregnancy and is a potential marker in the diagnosis and prognosis of both pregnancy and trophoblastic diseases. Murine hybridomas were generated against purified hCG. Seven hybrid clones secreting antibodies against hCG molecule with IgG1/kappa subclass were established. The indirect ELISA result demonstrated that six MAbs (BEL-1 to BEL-6) recognized hCG in both holo and free beta subunit form with negligible cross-reactivity against a closely related hormone, human luteinizing hormone (hLH). In this fusion, only one MAb (ALC-1) showed a cross-reaction with hLH, which designated an alpha subunit specific. The outcome of Western blot ascertained that ALC-1 recognized the conformational epitope on alpha subunit of hCG at Mr 23 kDa band in nonreducing condition (NR). In contrast, epitopes belonging to all MAbs recognized beta subunit of hCG were in linear peptide structure at Mr 34 kDa band (NR) and Mr 26 kDa band (R). These six MAbs were further characterized by using two beta subunit carboxy-terminal synthetic peptides (beta109-119 and beta109-145). Three of them (BEL-1, BEL-3, and BEL-4) recognized only epitope harboring in beta109-145 fragment, the others recognized both types of the synthetic peptide. In order to select the most suitable MAbs specific to beta subunit of hCG for exploiting with ALC-1 in the sandwich-type immunometric assay, competitive ELISA was employed. Six individual MAbs specific to beta subunit of hCG were used to compete with biotinylated ALC-1 to evaluate the proximity of their epitopes on the holo form of hCG molecule. Of all six MAbs, BEL-5 depicted the lowest percent inhibition result, which indicated the bottom-most steric hindrance effect. Consequently, MAb BEL-5 will be the most appropriate antibody to utilize in concert with ALC-1 in place of devising a sandwich-type immunometric assay for measuring holo-hCG level.

Amino Acid Sequence↗

PubMed1987

The presence of an aberrant type of human chorionic gonadotropin in patients with gastric or colorectal cancer.

Beta subunits of human chorionic gonadotropin (beta-hCG) and human chorionic gonadotropin-like substance (hCGLS) were measured radioimmunologically in the serum and malignant tissue from patients with gastrointestinal cancer. Since serum beta-hCG and hCGLS correlate closely to those in cancer tissues, it is assumed that these two gonadotropins originate from cancer tissues. The serum hCGLS levels in 54 patients with gastrointestinal cancer were significantly higher, when compared with the findings in 19 healthy volunteers and 10 peptic ulcer patients. The frequency of high levels of serum hCGLS accounted for 71 per cent of those with operable gastric cancer, 44 per cent of those with inoperable gastric cancer, 100 per cent of those with operable colorectal cancer, and 67 per cent of those with inoperable colorectal cancer. On the contrary, serum beta-hCG levels did not differ between the volunteers and the cancer patients. In the 17 sera and 15 cancer tissues assayed, beta-hCG did not correlate to hCGLS. Moreover, the high levels of beta-hCG in cancer patients occurred in only 1/14 (7.1 per cent) of the assayed serum, and in 5/14 (35.7 per cent) of the cancer tissue. The increased production of these two hCGs may result from neoplastic transformation of an unrestrained fetal genome responsible for hCG production during gestation. It is assumed that the increased producibility of a defective hCG, i.e., an aberrant hCG such as hCGLS, is characteristic of malignant tumors.

Chorionic Gonadotropin↗

PubMed1998

Prognostic value of chorionic gonadotropin beta gene transcripts in human breast carcinoma.

The beta subunit of human chorionic gonadotropin is potentially encoded by six genes, which can be categorized into two types based on a sequence change at codon 117: GCC for the type I and GAC for the type II genes. We previously showed that, whereas type I genes were exclusively expressed in normal breast tissues, expression of type II genes was associated with malignant transformation (Bellet, D., et al. Cancer Res., 57: 516-523, 1997). We designed a simple and robust test (the CG117 assay) that measures the percentage of type II over both types of chorionic gonadotropin beta mRNAs. Normal breast tissues consistently had a negative CG117 index, whereas cancer breast tissues showed indexes ranging from 0 to 100%. The prognostic significance of the CG117 index was investigated in a series of 99 unilateral invasive primary breast cancer patients with known long-term outcome (median follow-up, 9 years). The CG117 index was positive in 48 (48.5%) of the 99 tumor mRNA samples. The index was not significantly associated with standard prognostic parameters, including clinical and macroscopic tumor size, histopathological grade, and lymph node status or steroid receptor status. Patients with a positive CG117 index in primary tumor mRNA had significantly shorter metastasis-free survival (P = 0.014) and overall survival (P = 0.038) after surgery, compared to patients with a negative index. The prognostic significance of the CG117 index persisted in Cox multivariate regression analysis, both for metastasis-free survival (P = 0.008) and overall survival (P = 0.016), together with lymph node status (P = 0.027 and P = 0.009, respectively). These findings indicate that the CG117 index may contribute to the identification of high-risk breast cancer patients.

Adult↗

PubMed1997

The biologic action of single-chain choriogonadotropin is not dependent on the individual disulfide bonds of the beta subunit.

Disrupting disulfide loops in the human chorionic gonadotropin beta subunit (CGbeta) inhibits combination with the alpha subunit. Because the bioactivity requires a heterodimer, studies on the role of disulfide bonds on receptor binding/signal transduction have previously been precluded. To address this problem, we bypassed the assembly step and genetically fused CGbeta subunits bearing paired cysteine mutations to a wild-type alpha (WTalpha) subunit. The changes altered secretion of the single-chain mutants which parallel that seen for the CGbeta monomeric subunit. Despite conformational changes in CG disulfide bond mutants (assayed by gel electrophoresis and conformationally sensitive monoclonal antibodies), the variants bind to the lutropin/CG receptor and activated adenylate cyclase in vitro. The data show that the structural requirements for secretion and bioactivity are not the same. The results also suggest that the extensive native subunit interactions determined by the cystine bonds are not required for signal transduction. Moreover, these studies demonstrate that the single-chain model is an effective approach to structure-activity relationships of residues and structural domains associated with assembly of multisubunit ligands.

Chorionic Gonadotropin↗

PubMedDate not supplied

Clinical applications of urinary gonadotropin peptides (UGP) in gynecologic oncology.

The past seven years has witnessed the development of research assays and now commercial assays for the measurement of a fragment of the beta subunit of human chorionic gonadotropin (beta-hCG). This fragment has been called the beta core fragment (beta-core), urinary gonadotropin fragment (UGF) and most recently urinary gonadotropin peptide (UGP). Clinical applications of UGP have been pursued most often but not exclusively in gynecologic oncology. This review presents evidence for a role for UGP in (1) the screening of women at high risk for ovarian cancer by virtue of their family history, (2) the differentiation of benign pelvic masses from malignant ones, particularly in premenopausal women and (3) monitoring women known to have previously been diagnosed with ovarian cancer and possibly cervical and advanced uterine cancer to determine efficacy of therapy.

Biomarkers, Tumor↗

PubMed2004

[Relationship between imbalanced synthesis of human chorionic gonadotropin alpha and beta subunits and pregnancy-induced hypertension].

OBJECTIVE: To study the relationship between imbalanced synthesis of human chorionic gonadotropin (hCG) alpha and beta subunits and the pathology of pregnancy-induced hypertension (PIH). METHODS: Total hCG, free alphahCG and betahCG were measured in serum samples collected from 60 cases of PIH and 30 normal gravid women by radioimmunoassay. The ratio of total hCG/betahCG, betahCG/FalphahCG, (FalphahCG+betahCG)/betahCG were calculated. Immunohistochemical staining was performed in 13 placenta from each group. RESULTS: In PIH group the levels of FalphahCG, total hCG and betahCG were significantly higher than those of normal group (FalphahCG: 528 +/-421 IU/L compared with 222 +/-129 IU/L; betahCG: 39396 +/-6412 IU/L compared with 24265 +/-5575 IU/L; total hCG: 66597 +/-9294 IU/L compared with 36078 +/-4767 IU/L, all P<0.001). The betahCG/FalphahCG ratio in PIH was lower than that of normal group (91.23 +/-53.38 Compared with 119.4 +/-80.1, P<0.05); (FalphahCG+betahCG)/betahCG ratio and total hCG/betahCG ratio in two groups were (1.022 +/-0.026 compared with 1.015 +/-0.011; 1.802 +/-0.339 compared with 1.807 +/-0.258, respectively P>0.05). The immunohistochemical intensity of betahCG and FalphahCG in syncytiotrophoblast was significantly increased in 13 PIH compared with the control. CONCLUSION: These data suggested that the imbalanced synthesis of hCG alpha and beta subunits may cause hypertension.

Adult↗

PubMed1975

Monitor of chemotherapy in gestational trophoblastic neoplasm by radioimmunoassay of the beta-subunit of human chorionic gonadotropin.

Radioimmunoassays and bioassays based on the reactions of the native molecule of human chorionic gonadotropin (HCG) fail to differentiate HCG from pituitary luteinizing hormone (LH). An assay based on the beta-subunit of HCG which detects HCG exclusively has been used in our laboratory to monitor patients undergoing chemotherapy for gestational trophoblastic disease (GTD). We have been able to differentiate minimal, persisting tumor activity from normal levels of pituitary gonadotropins and have based therapy on these findings. Alternatively, treatment has been terminated when HCG is no longer detectable in the serum. Tumor activity has been detected in the beta-subunit assay at a time when biologic activity in the urine indicated remission.

Adult↗

PubMed1985

Coordinate regulation of the messenger ribonucleic acids encoding the alpha- and beta-subunits of human chorionic gonadotropin in HeLa cells and butyrate-resistant variants.

Short term exposure of HeLa S3 cells to sodium butyrate induces accumulation of the mRNAs encoding both the alpha- and beta-subunits of hCG. Both mRNAs accumulate with the same kinetics and reach maximal levels with the same concentration of butyrate, suggesting that the levels of alpha and hCG beta mRNAs are coordinately regulated. In addition, induction of both mRNAs is tightly coupled with a similar increase in secreted levels of hCG subunit protein, further suggesting that regulation of CG biosynthesis in HeLa cells occurs before translation. To determine whether HeLa cells which have overcome the growth inhibitory properties of butyrate show uniformly high levels of alpha and hCG beta mRNAs, we isolated clonal variants by stepwise selection with increasing concentrations of butyrate. Of 69 isolated variants, at least 2 (AO and B2) display different patterns of CG gene expression. In AO cells, alpha-subunit mRNA was not detectable, while in B2 cells, the level of alpha-subunit mRNA was similar to that of wild-type HeLa S3 cells. Conversely, hCG beta mRNA levels in both variant cell lines approximated levels found in butyrate-treated HeLa S3 cultures, suggesting that the mRNAs for alpha and hCG beta are regulated independently. Analysis of genomic DNA by blot hybridization indicated that the alpha-subunit gene was present as a single unrearranged copy in HeLa S3 cells and in both variants, indicating that differences in alpha-subunit gene expression are not associated with major genomic alterations, but probably reflect more subtle changes.

Butyrates↗

PubMed1986

A map of the hCG beta-LH beta gene cluster.

The beta-subunit of human chorionic gonadotropin (hCG beta) is reportedly encoded by as many as seven non-allelic genes or pseudogenes. Previous studies have identified a cluster of three hCG beta gene copies and the single-copy lutropin-beta subunit (LH beta) gene, but overlap of this cluster with two additional pairs of hCG beta genes has not been demonstrated, despite the isolation of 18 genomic clones. To define the number and organization of non-allelic hCG beta gene copies, genomic Southern blot analyses were performed using hCG beta cDNA and gene-flanking unique-sequence probes. The data show the linear arrangement of six genes (or pseudogenes) and show that the hCG beta-IH beta gene cluster is present in a single 58-kilobase EcoRI fragment. Our map of the cluster indicates which of the cloned hCG beta genes reflect somatic genotypes rather than recombinant artifacts and will thus permit investigation of factors regulating expression during gestation.

Bacteriophage lambda↗

PubMed1975

The amino acid sequence of human chorionic gonadotropin. The alpha subunit and beta subunit.

The amino acid sequences of both the alpha and beta subunits of human chorionic gonadotropin have been determined. The amino acid sequence of the alpha subunit is: Ala - Asp - Val - Gln - Asp - Cys - Pro - Glu - Cys-10 - Thr - Leu - Gln - Asp - Pro - Phe - Ser - Gln-20 - Pro - Gly - Ala - Pro - Ile - Leu - Gln - Cys - Met - Gly-30 - Cys - Cys - Phe - Ser - Arg - Ala - Tyr - Pro - Thr - Pro-40 - Leu - Arg - Ser - Lys - Lys - Thr - Met - Leu - Val - Gln-50 - Lys - Asn - Val - Thr - Ser - Glu - Ser - Thr - Cys - Cys-60 - Val - Ala - Lys - Ser - Thr - Asn - Arg - Val - Thr - Val-70 - Met - Gly - Gly - Phe - Lys - Val - Glu - Asn - His - Thr-80 - Ala - Cys - His - Cys - Ser - Thr - Cys - Tyr - Tyr - His-90 - Lys - Ser. Oligosaccharide side chains are attached at residues 52 and 78. In the preparations studied approximately 10 and 30% of the chains lack the initial 2 and 3 NH2-terminal residues, respectively. This sequence is almost identical with that of human luteinizing hormone (Sairam, M. R., Papkoff, H., and Li, C. H. (1972) Biochem. Biophys. Res. Commun. 48, 530-537). The amino acid sequence of the beta subunit is: Ser - Lys - Glu - Pro - Leu - Arg - Pro - Arg - Cys - Arg-10 - Pro - Ile - Asn - Ala - Thr - Leu - Ala - Val - Glu - Lys-20 - Glu - Gly - Cys - Pro - Val - Cys - Ile - Thr - Val - Asn-30 - Thr - Thr - Ile - Cys - Ala - Gly - Tyr - Cys - Pro - Thr-40 - Met - Thr - Arg - Val - Leu - Gln - Gly - Val - Leu - Pro-50 - Ala - Leu - Pro - Gin - Val - Val - Cys - Asn - Tyr - Arg-60 - Asp - Val - Arg - Phe - Glu - Ser - Ile - Arg - Leu - Pro-70 - Gly - Cys - Pro - Arg - Gly - Val - Asn - Pro - Val - Val-80 - Ser - Tyr - Ala - Val - Ala - Leu - Ser - Cys - Gln - Cys-90 - Ala - Leu - Cys - Arg - Arg - Ser - Thr - Thr - Asp - Cys-100 - Gly - Gly - Pro - Lys - Asp - His - Pro - Leu - Thr - Cys-110 - Asp - Asp - Pro - Arg - Phe - Gln - Asp - Ser - Ser - Ser - Ser - Lys - Ala - Pro - Pro - Pro - Ser - Leu - Pro - Ser-130 - Pro - Ser - Arg - Leu - Pro - Gly - Pro - Ser - Asp - Thr-140 - Pro - Ile - Leu - Pro - Gln. Oligosaccharide side chains are found at residues 13, 30, 121, 127, 132, and 138. The proteolytic enzyme, thrombin, which appears to cleave a limited number of arginyl bonds, proved helpful in the determination of the beta sequence.

Amino Acid Sequence↗

PubMed1987

Persistent ectopic pregnancy.

From 1982-1986, 625 tubal ectopic pregnancies were treated at the University of Hawaii School of Medicine Affiliated Hospitals. The percentage of cases in which the involved tube was preserved increased from 7% in 1982 to 26% in 1986. The presence of persistent trophoblastic tissue was diagnosed by elevated serum levels of the beta subunit of human chorionic gonadotropin (beta-hCG) after conservative surgery in four patients. Three of the four patients developed intra-abdominal hemorrhage and required laparotomy. One patient remained asymptomatic despite elevated beta-hCG levels, which disappeared 60 days after surgery. Evaluation of histologic slides demonstrated persistent intraluminal trophoblastic tissue without invasion in two patients, and extraluminal invasion into the tubal wall in one patient. The use of postoperative serial beta-hCG titers might facilitate recognition of this complication in time to prevent further tubal damage and hemorrhage.

Adult↗

PubMed2002

Hemorrhagic shock from a ruptured ectopic pregnancy in a patient with a negative urine pregnancy test result.

Ectopic pregnancy has been increasing in frequency over the past 2 decades. The sudden rupture of a fallopian tube caused by ectopic pregnancy can lead to hemorrhagic shock and death if not diagnosed and treated in a timely fashion. The emergency physician is often the health professional that is called on to make the diagnosis and coordinate timely and effective intervention. The first step in the diagnosis of ectopic pregnancy is demonstration of pregnancy by means of a rapidly performed and sensitive qualitative urine test for the beta-subunit of human chorionic gonadotropin (beta-hCG). A negative urine pregnancy test result will generally be used to exclude ectopic pregnancy from further consideration. The following is a report of a patient presenting to an emergency department with hypovolemic shock in conjunction with 2 negative urine beta-hCG analysis results and a quantitative serum beta-hCG level of 7 mIU/mL, a value less than the lower limit of detection for the highly sensitive qualitative urine and serum tests. This case report demonstrates the importance of further consideration of the diagnosis of ectopic pregnancy in the setting of a negative urine pregnancy test result.

Adult↗