Desialylated and deglycosylated human chorionic gonadotropin are superagonists of native human chorionic gonadotropin in human thyroid follicles.

Highly purified human chorionic gonadotropin (hCG) interacts with the thyrotropin (TSH) receptor and stimulates triiodothyronine (T3) secretion, iodide uptake and organification, and cyclic adenosine monophosphate (cAMP) formation in human thyroid follicles. Because of interest in the role of the carbohydrate component in the structure-function relationships of hCG we undertook to deplete hCG of its sialic acid or carbohydrate residues and assess the thyrotropic activity of the carbohydrate-modified forms. For this purpose, we used our assay system consisting of human thyroid follicles cultured and suspended in collagen gel in serum-free medium.

A potential novel mechanism for precocious puberty in juvenile hypothyroidism.

Some children with juvenile hypothyroidism exhibit unexplained precocious puberty. Interaction of TSH with the human FSH receptor (hFSH-R) is a possible pathophysiological mechanism for this syndrome that has not been explored due to the lack of hFSH-free TSH preparations and the scarcity of a suitable hFSH-R-based assay system. To devise an in vitro FSH bioassay suitable for exploring this mechanism, we expressed hFSH-R complementary DNA in COS-7 cells and stimulated them with recombinant hTSH (rec-hTSH).

Increased biological activity due to basic isoforms in recombinant human follicle-stimulating hormone produced in a human cell line.

FSH has four asparagine-linked oligosaccharides with variable sialic acid contents, so that FSH is not a single molecule, but a heterogeneous group of isoforms. These isoforms differ in their biological properties and their distribution changes in various physiological states, allowing the modulation of FSH activity. Recombinant human (h) FSH has been produced in Chinese hamster ovary cells and has an isoform profile similar to those of both pituitary FSH standard and purified urinary FSH.

Human chorionic gonadotropin stimulates thyroid hormone secretion, iodide uptake, organification, and adenosine 3',5'-monophosphate formation in cultured human thyrocytes.

Despite extensive studies, the issue of whether hCG possesses intrinsic thyrotropic activity remains unresolved. This is mainly because in the experimental systems used so far, the parameters measured did not include the thyroid-specific functions of iodine organification and the hormonal end-point response, T3 secretion, and cells of nonhuman origin were employed, constituting a major drawback in view of the wide variation in sensitivity of thyroid responsiveness to hCG in different species. We investigated the thyrotropic activity of hCG, using for this purpose a novel homologous assay system consisting of human thyroid follicles cultured suspended in collagen gel in serum-free medium.

Modulation of the expression of murine lupus by gonadotropin-releasing hormone analogs.

Recent studies have suggested that hypothalamic and pituitary hormones may directly influence the immune system. One such hormone with immunomodulatory properties is GnRH. We hypothesized that GnRH and/or the gonadotropins might alter the severity of autoimmune disease through mechanisms distinct from their effects on gonadal hormones.

Site-directed mutagenesis defines the individual roles of the glycosylation sites on follicle-stimulating hormone.

To determine the specific role of each follicle-stimulating hormone (FSH) oligosaccharide, we mutated Asn to Gln at each glycosylation site (alpha Gln52, alpha Gln78, alpha Gln52-78, beta Gln7, beta Gln24, and beta Gln7-24) to selectively inhibit oligosaccharide attachment. For wild-type and mutant FSH, we determined the binding affinity to homogenized rat Sertoli cells and the signal-transducing activity in cultured rat granulosa cells. The binding affinity of FSH lacking any one of the oligosaccharides was increased over wild-type FSH, while the signal-transducing activity of FSH lacking the oligosaccharide at alpha Asn52 (alpha Gln52 FSH) was markedly reduced, and that of FSH lacking either beta oligosaccharide (beta Gln7 and beta Gln24 FSH) was slightly reduced.

Oral gossypol in the treatment of metastatic adrenal cancer.

Medical treatment of metastatic adrenal cancer is largely unsuccessful and has considerable toxicity. We previously demonstrated the activity of the plant toxin gossypol against human adrenal cancers in nude mice. We therefore examined the efficacy and toxicity of oral gossypol as a treatment for adrenal cancer in humans.

Standardization of protein immunoprocedures. Choriogonadotropin (CG).

The objectives of this report is to improve the quality of immunochemical determinations of proteins. Procedures for determination of the various molecular forms hCG were chosen as the subject of a detailed study, with the aim as using this report as a model for similar future projects. The aim of this undertaking is to improve the reliability and reproducibility of the results and, as a result of this, to enhance the clinical usefulness of hCG determinations.

Measurement of human chorion gonadotropin by biological methods.

The clinically significant biological activities of hCG result from its interaction with LH and TSH receptors. In vivo bioassays for measurement of these hCG activities have many disadvantages including complexity, expense, labor-intensity, and insensitivity. In vitro bioassays based on animal Leydig cell responses are widely used in research studies, but since they are based on animal receptors, their relevance to human biology remains uncertain.

Nocturnal thyrotropin surge in growth hormone-deficient children.

Because some patients with growth hormone (GH) deficiency are found to be hypothyroid after initiation of treatment with GH, we assessed the predictive value of the nocturnal thyrotropin surge (a sensitive test for central hypothyroidism) in 56 untreated GH-deficient children and adolescents. Eighteen patients had a subnormal thyrotropin surge (mean 18% (range -30% to 46%)), significantly less than that of 96 normal control subjects (mean 124%; 95% confidence limits, 47% to 300%; p less than 0.01); 13 of the 18 had a subnormal total thyroxine (T4) level or a subnormal free T4 level, or both.

Glycosylation changes in human chorionic gonadotropin and free alpha subunit as gestation progresses.

Carbohydrate is important to the structure, function, and circulatory survival of the glycoprotein hormones. Human CG (hCG) and the related free alpha-molecule of pregnancy contain four and two asparagine-linked oligosaccharides, respectively. The present study analyzes changes in the glycosylation patterns of hCG and free alpha in early vs.

Subtle primary hypothyroidism in patients treated for acute lymphoblastic leukemia.

We evaluated serum thyroid hormone and thyroid antibody levels, the serum TSH response to TRH, and the circadian pattern of serum TSH in 10 children and adolescents after radiation therapy for acute lymphoblastic leukemia. Four patients had received central nervous system preventive cranial irradiation and intrathecal chemotherapy, and the remaining 6 patients were treated with craniospinal irradiation for central nervous system relapse. Serum total T4 and T3 concentrations were within the normal range and thyroid antibodies were negative in all patients.

Uptake of erythrocyte-associated component of blood testosterone and corticosterone to rat brain.

To study transport of steroids by erythrocytes, the tissue uptake of erythrocyte-associated testosterone and corticosterone was studied in vivo using a single injection technique into the carotid artery of rats. A brain uptake index (BUI) was calculated by dividing the ratio of [3H]steroid to [14C]butanol (internal reference) in the brain tissue by that in the injection material, and multiplying by 100%. BUIs of testosterone and corticosterone in an erythrocyte suspension were 131 +/- 3% (mean +/- SE, n = 6) and 57.

Thyroid abnormalities in the McCune-Albright syndrome: ultrasonography and hormonal studies.

Hyperthyroidism and goiter have been reported frequently in association with the McCune-Albright syndrome (MAS). To assess the prevalence and extent of thyroid abnormalities in girls with MAS, we studied 19 patients [mean age, 6.6 +/- 1 (+/- SE) yr; mean bone age, 9.

beta-Core chemical and clinical properties.

beta-Core is the most abundant hCG-related molecule in pregnancy urine. The structure of beta-core as well as aspects of its metabolic clearance suggest that beta-core is a metabolic fragment of the hCG-beta subunit. The occurrence of beta-core in the urine of patients with a broad spectrum of malignancies imparts an important role to beta-core as a tumor marker.

Hypothyroidism and deficiency of the nocturnal thyrotropin surge in children with hypothalamic-pituitary disorders.

The circadian pattern of serum TSH in normal children, aged 5-18 yr, is characterized by a nocturnal surge and is presumably related in some way to a biological clock within the central nervous system. To look for patients deficient in the nocturnal TSH surge, we studied 52 children with hypothalamic-pituitary disorders. Thirteen of the children were hypothyroid, as judged by subnormal serum free T4 (FT4).

Human chorionic gonadotrophin-like and beta-core-like materials in postmenopausal urine.

In addition to human chorionic gonadotrophin (hCG), the urine of pregnant women contains a small molecular weight form of the hCG-beta subunit known as beta-core. Human CG-like material has been described in tissues, serum and urine of normal man, particularly in postmenopausal women. We examined different urine preparations from postmenopausal women to determine whether beta-core-like material, as well as hCG-like material, could be detected.

The binding properties of pyrethroids to human skin fibroblast androgen receptors and to sex hormone binding globulin.

The pyrethroids are a class of natural and synthetic pesticides which were associated with an epidemic of gynecomastia in Haitian men in 1981. In the present study we tested several pyrethroids for their ability to interact with androgen binding sites in dispersed, intact human genital skin fibroblasts and in human plasma to sex hormone binding globulin (SHBG). All the pyrethroids tested inhibited fibroblast binding of [3H]methyltrienolone (R1881) at 22 degrees C with the following rank order of potency:pyrethrins greater than bioallethrin greater than fenvalerate greater than fenothrin greater than fluvalinate greater than permethrin greater than resmethrin.

Disparity between beta-core levels in pregnancy urine and serum: implications for the origin of urinary beta-core.

We used a highly purified preparation of the naturally occurring core fragment of hCG beta (beta-core) and a new RIA for beta-core to investigate the concentrations and behavior of beta-core in serum and urine. We collected serum and 24-h urine specimens from healthy pregnant women during the first trimester of pregnancy. The concentrations of beta-core in serum were determined by analysis of fractions eluted from Sephadex G-100.

Reduced metabolic clearance of acidic variants of human choriogonadotropin from patients with testicular cancer.

We investigated the plasma disappearance of purified urinary human choriogonadotropin (hCG) and acidic variants of hCG (AV-hCG) that are excreted in the urine of patients with testicular cancer to determine if there are differences in their disappearance rates. All cancer patients had relatively increased fractions (10% to 46%) of AV-hCG in their serum when compared with hCG from pregnant control subjects (less than 4% present as AV-hCG). After initiation of therapy in 12 patients with nonseminomatous testicular tumors, the proportion of hCG present as acidic variants in serum rose despite lower serum total hCG concentrations.

Carbohydrate composition of beta-core.

beta-Core is a major component of the hCG-related molecules found in pregnancy urine. We previously have purified the beta-core molecule and have deduced portions of its carbohydrate structure based on lectin binding data. In the present study we used recently developed technology to determine the carbohydrate composition of beta-core and hCG beta (CR119).

Metabolic fate of human choriogonadotropin.

Review of the literature reveals a number of recent insights concerning the metabolic fate of human choriogonadotropin (hCG). In man, only a fraction (21.7%) of the circulating hCG molecules is excreted in urine.

Metabolic clearance rate and urinary clearance of purified beta-core.

We injected a highly purified preparation of the beta-core molecule, a fragment of hCG beta excreted in pregnancy urine, into five men and three women to determine its kinetic parameters, MCR, and urinary clearance. The beta-core molecule was distributed in an initial volume [1950 +/- 156 (mean +/- SEM) mL/m2 body surface area] approximately equal to the estimated plasma volume. Its disappearance was multiexponential on a semilogarithmic plot, with a rapid phase t1/2 of 3.

Effects of hyperthyroidism on binding proteins for steroid hormones.

Sex hormone binding globulin (SHBG) and corticosteroid binding globulin (CBG) binding capacities were examined weekly in eight normally cycling women and three women taking birth control pills during a 5-week baseline period and after daily ingestion of 75 micrograms of L-triiodothyronine (T3) for 30 days. The SHBG binding capacity increased whereas the CBG binding capacity decreased after T3 therapy. The binding capacities of proteins for steroid hormones were measured in 18 hyperthyroid subjects (Graves' disease) prior to and after 3 months of antithyroid drug therapy.

Effect of alcohol on the interaction of cortisol with plasma proteins, glucocorticoid receptors and erythrocytes.

Alcohol ingestion stimulates glucocorticoid secretion in animals and normal men. It is generally believed that this effect is mediated through the pituitary-adrenal axis. To investigate its mechanism, we focussed on the effects of ethanol on cortisol binding to plasma proteins and to glucocorticoid receptors, and on cortisol uptake by erythrocytes.