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Carcinoembryonic antigen (CEA), alphafetoprotein (AFP) alpha and beta subunits of human chorionic gonadotropin (hCG) in cerebrospinal fluid of children with acute lymphoblastic leukaemia.

The cerebrospinal fluid (CSF) and plasma levels of CEA, AFP, alpha and beta hCG were determined by radioimmunoassay in 19 children with acute lymphoblastic leukaemia (ALL). CSF in 15 patients at the onset of ALL was examined in the first week after diagnosis and subsequently every two months. In 4 other children in second complete remission of ALL, CSF was examined every two months as well. Elevated values of CEACSF were present in 1/15 patients at the onset of ALL, of AFPCSF 0/15, alpha hCGCSF in 2/15, beta hCGCSF in 2/15 cases. The elevated levels of these markers in CSF became normal in successive lumbar punctures and none of these children developed central nervous system (CNS) relapse in further follow-up. Isolated CNS relapses were diagnosed 13 times in 7 children. Elevated CEACSF levels were found in 6/13 cases (maximum, 25.0 ng/ml) and in one patient CEACSF levels correlated well with pleocytosis. Elevated AFPCSF values were present in 0/13 cases, alpha hCGCSF in 0/13 and beta hCGCSF in 3/13 patients and became normal by the next CSF examination. The determination of CEA, AFP, alpha and beta hCG in plasma did not play a role in monitoring CNS relapse in ALL patients.

Adolescent↗

A nicked beta-subunit of human chorionic gonadotropin purified from pregnancy urine.

Human chorionic gonadotropin (hCG) is a glycoprotein hormone composed of two dissimilar subunits (alpha and beta) and normally excreted in urine of pregnant women. An uncommon beta-subunit of hCG was purified from fresh early normal pregnancy urine by Sepralyte C8, resin adsorption. Sephadex G-100 column chromatography, and reverse-phase HPLC. SDS-PAGE under non-reducing conditions showed that the apparent molecular weight (39,000) of this beta-subunit was extremely similar to that of the native beta-subunit, which is known to consist of 145 amino acid residues and carbohydrates. However, SDS-PAGE, under reducing conditions, resulted in two bands with apparent molecular weights of 22,000 and 18,000, indicating that it consisted of two peptide fragments connected with disulfide bridge(s). These two peptide fragments, separated and purified from the reduced and carboxymethylated protein, were subjected to amino acid and N-terminal sequence analyses. It was found that this beta-subunit consisted of two polypeptide chains composed of residues 1-47 disulfide-bridged to residues 48-145 of the beta-subunit, which may be produced by nicking of the beta-subunit at the one site (Gly47-Val48). This beta-subunit was termed a nicked beta-subunit of hCG (N-hCG beta). It was also found that N-hCG beta was present in urine as an alpha beta dimer, indicating that an intrachain nicking of this site in the beta-subunit does not inhibit alpha beta dimer formation.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗

[A case report of germinoma with syncytiotrophoblastic giant cells (STGC) in the basal ganglia].

We report a case of germinoma with syncytiotrophoblastic giant cells (STGC) in the basal ganglia which was encountered at the Department of Neurosurgery, Hiratsuka City Hospital, Kanagawa, Japan. A 9-year-old boy was admitted to our hospital on September 13th, 1993 because of left hemiparesis and precocious puberty. Endocrinological examination revealed a high serum level of human chorionic gonadotropin (HCG) (290 mIU/ml) and beta-subunit human chorionic gonadotropin (HCG-beta) (1.3 ng/ml). Plain CT scan showed an irregularly-defined mass lesion in the right basal ganglia, which had several low density spots and was inhomogeneously enhanced on contrast CT scan. The tumor developed from the right putamen to the thalamus and showed a tendency towards involvement of the hypothalamic region on MR imaging. We performed a right front-temporal craniotomy on 29th September, 1993, and a piece of the tumor was removed. It was histologically diagnosed to be germinoma with STGC. We treated the patient with carboplatin and etoposide (CBDCA 200 mg/m2day1, VP-16 60 mg/m2day1-5) chemotherapy and radiotherapy (local 30 Gy) after surgery. Postoperative course was good without recurrent signs. He is now in good health and going to elementary school without neurological deficit. There are very few reports of germinoma with STGC arising in the basal ganglia. We provide a new treatment of germinoma with STGC, chemotherapy and radiotherapy after surgery.

Basal Ganglia Diseases↗

Fragmentation of the beta-subunit of human chorionic gonadotropin produced by choriocarcinoma.

When human chorionic gonadotropin (hCG) was subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis under reducing conditions with dithiothreitol (DTT), a smaller weight material (CTP'), in addition to the beta-subunit, could be detected by Western blot analysis using antiserum for hCG beta-carboxy-terminal peptide (CTP). The CTP' band was much more apparent with urinary hCG from a patient with choriocarcinoma than with that from normal pregnant women. Second-dimensional electrophoresis of the choriocarcinoma hCG (c-hCG) after reduction with DTT indicated that the CTP', Mr 25,000, was released from the beta-subunit. The carbohydrate structure of the CTP' was analyzed by affinity with lectin-peroxidase on a nitrocellulose membrane. The CTP' did not interact with Concanavalin A, but exhibited strong interaction with both RCA120 and Arachis hypogaea after removal of sialic acid, indicating that it was released as a fragment containing an O-linked sugar chain as was found in the hCG beta carboxy-terminal portion. Western blot analysis using the antisera for hCG alpha, hCG beta, and hCG beta-CTP showed that the CTP' contains not only the carboxy-terminal portion but also a part of the internal (core) portion of the beta-subunit molecule. This dissociation of the c-hCG beta was further supported by the presence of a faster moving component (FMC) which may correspond to the NH2-terminal side counterpart. The desialylated FMC could be detected by Concanavalin A and RCA120 but not by Arachis hypogaea, indicating that it contains N-linked rather than O-linked sugar chains. The FMC does not contain any of the epitopes for the antisera examined in Western blot. These results indicate that the beta-subunit of the choriocarcinoma urine hCG has an unusual site which is dissociated into two components of Mr 25,000 (CTP') and Mr 18,000 (FMC) by DTT reduction.

Choriocarcinoma↗

Human chorionic gonadotropin beta-subunit affects the folding and glycosylation of alpha-cys mutants.

Human chorionic gonadotropin (hCG) is a member of a family of heterodimeric glycoprotein hormones that contain a common alpha-subunit but differ in their hormone-specific beta-subunits. Both subunits have five and six disulfide bonds, respectively, which consist of cystine knot structure. It is evident from numerous studies that the structure of beta-subunits is rigid, whereas that of alpha-subunit is flexible and can be molded by a beta-subunit. Previously, we reported that secreted forms of a mutants where either cysteine residue in the disulfide bond 7-31 or 59-87 was converted to alanine contained a disulfide-linked homodimer in addition to a monomer. To study whether the hCGbeta-subunit affects the conformations of alpha mutants, alpha-subunits lacking either the 7-31 or 59-87 disulfide bond were expressed with wild-type (WT) hCGbeta in Chinese hamster ovary cells, and homodimer formation and glycosylation of dimerized alpha-subunit were assessed by continuous labeling with [35S]methionine/cysteine, immunoprecipitation with anti-alpha or -hCGbeta serum, digestion with endoglycosidase-H or -F, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis in a non-reducing condition. Our data showed that a homodimer was not observed in the half-Cys mutants except one, where cysteine at position 7 was converted to alanine, in the presence of beta-subunit. This finding indicated that hCGbeta-subunit rescued the a half-Cys mutants from the formation of intermolecular disulfide-linked homodimer by preferentially combining with the alpha mutants. In both free WT and all mutants treated with endoglycosidase-H, no or faint bands were recognized as the same migration as seen in endoglycosidase-F treatment. Even in the endoglycosidase-H sensitive cases, the amount of sensitive alpha-subunits was less than 5% of total alpha-subunits. In contrast to free alpha-subunits, distinct endoglycosidase-H sensitive bands were seen in both WT and mutants, although the ratio was various. We concluded that hCGbeta-subunit affects the folding and glycosylation of the alpha-subunit mutants.

Amino Acid Substitution↗

Mutagenesis and chimeric genes define determinants in the beta subunits of human chorionic gonadotropin and lutropin for secretion and assembly.

Chorionic gonadotropin (CG) and lutropin (LH) are members of a family of glycoprotein hormones that share a common alpha subunit but differ in their hormone-specific beta subunits. The glycoprotein hormone beta subunits share a high degree of amino acid homology that is most evident for the LH beta and CG beta subunits having greater than 80% sequence similarity. However, transfection studies have shown that human CG beta and alpha can be secreted as monomers and can combine efficiently to form dimer, whereas secretion and assembly of human LH beta is less efficient. To determine which specific regions of the LH beta and CG beta subunits are responsible for these differences, mutant and chimeric LH beta-CG beta genes were constructed and transfected into CHO cells. Expression of these subunits showed that both the hydrophobic carboxy-terminal seven amino acids and amino acids Trp8, Ile15, Met42, and Asp77 together inhibit the secretion of LH beta. The carboxy-terminal amino acids, along with Trp8, Ile15, Met42, and Thr58 are implicated in the delayed assembly of LH beta. These unique features of LH beta may also play an important role in pituitary intracellular events and may be responsible for the differential glycosylation and sorting of LH and FSH in gonadotrophs.

Amino Acid Sequence↗

Disulfide bond mutations affect the folding of the human chorionic gonadotropin-beta subunit in transfected Chinese hamster ovary cells.

Previous kinetic studies have characterized the intracellular folding pathway of the human chorionic gonadotropin (hCG)-beta subunit in which each of the folding intermediates can be biochemically identified based on the formation of disulfide (S-S) bonds: p beta 1-early--> p beta 1-late--> p beta 2-free--> p beta 2-combined--> native hCG-alpha beta. Based on these data, we postulated that hCG-beta folding coincides with the formation of specific S-S bonds. We have now tested this hypothesis employing Chinese hamster ovary cells transfected with mutated hCG-beta genes in which the Cys residues required for the formation of the final four (of six total) S-S bonds were replaced by Ala. When the Cys residues required for the third hCG-beta S-S linkage to form (bond 9-90) were substituted, folding did not proceed beyond the earliest detectable folding intermediate (p beta 1-early). In the absence of the subsequently formed S-S bond (bond 23-72), p beta 1-early was converted into a second folding intermediate (p beta 1-late), but conversion to the next intermediate (p beta 2-free) was inhibited. When either of the final two S-S bonds (the carboxyl-terminal 93-100 or 26-110 bonds) were removed, conversion of p beta 1-late to p beta 2-free was detected, but conversion of p beta 2-free to the last folding intermediate (p beta 2-combined) was not observed. These data support the hypothesis that individual S-S bonds are involved in discrete steps in the hCG-beta folding pathway.

Alanine↗

Prospective evaluation of free beta-subunit of human chorionic gonadotropin and dimeric inhibin A for aneuploidy detection.

OBJECTIVE: Our goal was to prospectively evaluate the use of the free beta-subunit of human chorionic gonadotropin and dimeric inhibin A for the detection of fetal Down syndrome and other aneuploidies. STUDY DESIGN: Women who had a second-trimester multiple-marker screening test (alpha-fetoprotein, unconjugated estriol, human chorionic gonadotropin) and genetic amniocentesis from August 1996 to August 1998 were included. Serum was also analyzed for inhibin and the free beta-subunit of human chorionic gonadotropin. Detection and false-positive rates for 4 analyte combinations at 5 different screening risk cutoff points for Down syndrome were determined and compared. RESULTS: We evaluated 1256 patients, including 23 with aneuploidy (13 with Down syndrome, 10 others). The maternal age was 35.9 +/- 4.6 years (mean +/- SD). At the optimal risk cutoff point for Down syndrome detection (1:190; false-positive rate, 19%), the multiple-marker screening test plus inhibin was superior, detecting 85% of Down syndrome cases, in comparison with 69% when the multiple-marker screening test alone was used and 62% when the other 2 combinations were used. The multiple-marker screening test plus inhibin also detected 60% of the other aneuploidies. CONCLUSIONS: When evaluated prospectively in a high-risk population, the multiple-marker screening test plus inhibin was superior to the traditional multiple-marker screening test and 2 other analyte combinations, with a lower false-positive rate and increased detection of all aneuploidies in a high-risk population.

Amniocentesis↗

[Beta subunit of human chorionic gonadotropin, CA 125 antigen and CA 19-9 antigen with non-trophoblastic malignancy of genital tract. Vulval cancer].

Our investigations embraced the group of patients with vulval cancer before surgical treatment (n = 10). We measured in serum of blood the level of the total human chorionic gonadotrophin hCG, beta subunit of human Chorionic Gonadotrophin, CA 125 and CA 19-9 antigen. We ascertained significant elevation the beta subunit of hCG level in the group of women with neoplasms in comparison with control group (n = 96) and significant positive correlation between beta subunit level and degree of cancer cells maturity (r = 0.66, p < 0.05). We also ascertained strong positive correlation among beta subunit of hCG and CA 19-9 antigen level in the serum of the patients with vulval cancer (r = 0.55 and p < 0.05).

CA-125 Antigen↗

Monoclonal versus polyclonal antibody radioimmunoassay against the beta-subunit of human chorionic gonadotropin in patients with gestational trophoblastic neoplasia.

The level of human chorionic gonadotropin (hCG) in series of sera from eight patients with gestational trophoblastic neoplasia was measured by monoclonal antibody and polyclonal antibody radioimmunoassay. A comparative analysis was performed. Three commercially available monoclonal anti-beta-subunit of hCG (beta-hCG) antibodies were evaluated and the most specific and sensitive one was chosen to develop a quantitative beta-hCG radioimmunoassay. beta-hCG radioimmunoassay kits from Nuclear Medical Systems, Inc., and Clinical Assays served as polyclonal antibody assays. Results obtained with the monoclonal antibody radioimmunoassays demonstrated a high degree of correlation (r greater than 0.95, p less than 0.01) with those obtained by the polyclonal antibody techniques; however, the sera from one patient continuously demonstrated a low level of hCG in the monoclonal antibody radioimmunoassay while registering undetectable levels in the polyclonal antibody assays. Although the monoclonal antibody radioimmunoassay appears to be specific and fairly sensitive, the results indicate that, with current technology, there is no special advantage to employing this assay to measure hCG in patients with gestational trophoblastic neoplasia.

Antibodies↗

The beta subunit of human chorionic gonadotropin lacks specificity for malignant cells in serous effusions.

The cytologic diagnosis of malignancy is frequently straightforward. For difficult cases, multiple immunostains and immunostain panels have been investigated without consensus. beta-human chorionic gonadotropin (hCG) has been reportedly expressed in malignancies, but not in normal tissue. HCG also has been reported as a specific marker of metastases in serous fluids when detected with laboratory assays. We investigated the clinical utility of hCG in this cytologic setting. A total of 97 cases of benign and malignant effusions were studied. Each case was immunostained with monoclonal hCG using the avidin-biotin technique and diaminobenzidine as a chromogen. Additionally, a mucicarmine stain was performed on most cases. Cases were evaluated for hCG expression and mucin in a blinded fashion. After the cases were reviewed, the diagnoses were unblinded and staining patterns were evaluated. Of the 47 benign cases studied, 23 (49%) exhibited immunoreactivity to hCG in at least 5% of mesothelial cells present. In contrast, 28 of 44 (64%) adenocarcionomas exhibited a similar degree of immunostaining. In all, 21 (48%) of the adenocarcinomas were also positive for mucin; five of these mucin-positive cases were negative for hCG. The combination of mucin and hCG detected 33 of 44 (75%) adenocarcinomas. We conclude that hCG lacks the specificity for malignant cells to be of clinical use in effusion cytology.

Adenocarcinoma↗

Midtrimester urine human chorionic gonadotropin beta-subunit core fragment levels and the subsequent development of pre-eclampsia.

OBJECTIVE: Our purpose was to determine whether midtrimester maternal urine human chorionic gonadotropin beta-subunit core fragment predicts later pre-eclampsia. STUDY DESIGN: Urine beta-core fragment levels standardized to spot creatinine concentration and expressed as multiples of the median were prospectively determined in 347 midtrimester singleton pregnancies undergoing genetic amniocentesis. All women considered in the analysis were white and nonsmokers. Obstetric chart review was undertaken after delivery to identify cases in which pre-eclampsia developed. The risk of pre-eclampsia at different threshold levels of beta-core fragment of human chorionic gonadotropin was determined. RESULTS: The median maternal age was 36.0 years, with a median gestational age at urine collection of 16.0 weeks. The median level of the beta-core fragment of human chorionic gonadotropin was 1385.5 ng/mg of creatinine in those with pre-eclampsia, whereas that in those without pre-eclampsia was 1061.2 ng/mg. The difference was significant (Mann-Whitney U test, P = .03). A significant linear association was found between the beta-core fragment concentration and the risk of pre-eclampsia (Mantel-Haenszel test of linear association, P = .03). The relative risk and 95% confidence interval of subsequent pre-eclampsia increased from 2.07 (1.06 to 4.05) at beta-core fragment levels of human chorionic gonadotropin > or = 2.0 multiples of the median to 5.17 (1.95 to 13.7) at > or = 4.0 multiples of the median. CONCLUSION: Clinically normal patients with elevated midtrimester levels of urine beta-core fragment of human chorionic gonadotropin are at increased risk for the subsequent development of pre-eclampsia. The clinical value of this urine analyte as a marker for pre-eclampsia needs to be further investigated.

Adult↗

Effect of an in vitro fertilization program on serum CA 125, tumor-associated trypsin inhibitor, free beta-subunit of human chorionic gonadotropin, and common alpha-subunit of glycoprotein hormones.

OBJECTIVE: To investigate the impact of an IVF program on serum levels of tumor markers CA 125, tumor-associated trypsin inhibitor, free hCG beta-subunit, and free glycoprotein hormone alpha-subunit. DESIGN: A prospective controlled clinical study. SETTING: Outpatient university infertility clinic. PATIENT(S): Seventy-one infertile patients (with tubal occlusion, pelvic endometriosis, or unexplained infertility) undergoing IVF and nine control women with regular menstrual cycles. INTERVENTION(S): Serial blood sampling before, during, and after IVF, or during one ovulatory menstrual cycle in the controls. MAIN OUTCOME MEASURE(S): Serum levels of CA 125, tumor-associated trypsin inhibitor, hCG-beta, and glycoprotein hormone-alpha. RESULT(S): Before IVF, all tumor markers were within the normal range except for CA 125, which was elevated in patients with endometriosis. IVF led to significant increases in CA 125 and glycoprotein hormone-alpha that differed from the changes seen during normal menstrual cycles. The luteal phase increase in CA 125 correlated with levels of E(2) and P and the number of follicles. Two months after IVF, levels of CA 125 were 12% higher than levels before treatment. Tumor-associated trypsin inhibitor and hCG-beta revealed no cyclicity. CONCLUSION(S): An IVF regimen increased the release of CA 125 and glycoprotein hormone-alpha. The CA 125 elevation after IVF implies a persistent effect of ovarian hyperstimulation on CA 125 release.

Adult↗

Carcinoembryonic antigen, alphafetoprotein and alpha and beta subunits of human chorionic gonadotropin in plasma of children with acute leukaemia.

The plasma carcinoembryonic antigen, alpha-fetoprotein and the alpha and beta subunits of human chorionic gonadotropin levels were measured by radioimmunoassay in 44 children with acute leukaemia. These markers were determined repeatedly every 3 months at different stages of the disease (at onset, in complete remission, during bone marrow and extramedullary relapse). Elevated CEA levels were present in 64% of children at the onset of acute leukaemia and during bone marrow relapse. Elevated CEA levels decreased during induction treatment and they became normal with attainment of complete remission. In 7/12 patients who developed bone marrow relapse elevated CEA levels and in 4 of them raised levels appeared 3-4 months before there had been any other evidence of relapse. In 6/13 patients with extramedullary relapse, elevated CEA levels were found. AFP, alpha and beta hCG values in different stages of the disease were elevated sporadically; they did not reflect the activity of leukaemia.

Adolescent↗

Radioimmunoassay of free beta-subunit of human chorionic gonadotropin as a prognostic test for persistent trophoblastic disease in molar pregnancy.

A new radioimmunoassay system was established with a monoclonal antibody (1E5) that distinguishes the free beta-subunit of human chorionic gonadotropin in the presence of intact human chorionic gonadotropin, showing only 0.23% cross-reactivity with the intact human chorionic gonadotropin molecule and virtually no cross-reactivity with other glycoprotein hormones or their beta-subunits. Serum samples, taken at initial diagnosis from nine patients with hydatidiform mole and spontaneous remission and 12 patients with subsequent progression to persistent trophoblastic disease, were assayed for free and total levels of the beta-subunit of human chorionic gonadotropin. The assay results were expressed as a ratio of nanograms of free beta-subunit per 1000 mIU of total beta-subunit. Eight of nine patients with mole and spontaneous remission had a ratio value less than 4 whereas 10 of 12 patients with subsequent persistent disease had a ratio value greater than 4. Statistical analysis with chi 2 showed a highly significant correlation of high ratios with eventual progressive disease (p = 0.0009). This study suggests that excessive production of the free beta-subunit of human chorionic gonadotropin may identify patients with a high likelihood of developing persistent trophoblastic disease.

Chorionic Gonadotropin↗

Identification of patients with persistent trophoblastic disease by means of a normal human chorionic gonadotropin regression curve.

OBJECTIVE: Data from the Dutch Central Registry of Hydatidiform Mole were used to establish a reference human chorionic gonadotropin regression curve after molar pregnancy. STUDY DESIGN: A normal serum human chorionic gonadotropin regression corridor was constructed after fitting data from 130 patients with uneventful human chorionic gonadotropin regression after evacuation of a complete hydatidiform mole. Retrospectively, data from 77 patients with persistent trophoblastic disease were analyzed by means of this normal corridor. Measurements were performed with a radioimmunoassay for both native and free human chorionic gonadotropin beta-subunits. RESULTS: Human chorionic gonadotropin disappearance curves showed a biphasic decline with median serum half-lives of 1.8 and 12.8 days. Median time until normalization was 74 days (range 28 to 430). With the 95th percentile line, 71 of 77 patients (92%) with persistent trophoblastic disease could be identified. In > 50% of cases this could be achieved within 6 weeks from evacuation. CONCLUSION: The normal regression corridor allows identification of patients with persistent trophoblastic disease and an expectant attitude within the limits of the corridor.

Chorionic Gonadotropin↗