The oligosaccharide structures of heterodimeric glycoprotein hormones, such as follicle-stimulating hormone (FSH), have been shown to play an important role in the biosynthesis, secretion, metabolic fate, and regulation of potency of the hormone. The oligosaccharide structures attached to each subunit of the protein seem to exhibit distinct roles in some of these functions. Glycans attached to the alpha-subunit are critical for dimer assembly, integrity, and secretion, as well as for signal transduction; although beta-subunit glycans are also important for dimer assembly and secretion, they play a crucial role in clearance of the dimer from the circulation. Alternative glycosylation on FSH and other glycoprotein hormones not only may affect the metabolic clearance and net in vivo biopotency of the hormone, but also offers the interesting possibility that some glycosylation variants of the hormone may provoke differential or even unique effects at the target cell level. Glycosylation of FSH is regulated by hypothalamic and/or end products from the glands under the control of this hormone. In particular, estrogens regulate terminal sialylation and thus some functional properties of the gonadotropin influenced by sialic acid. Through these extrapituitary inputs, the gonadotroph may regulate not only the amount but also the intensity of the gonadotropin signal to be secreted by the pituitary in a given physiological condition.

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The aims of the present study were to examine whether the pattern of syndecan-1 expression correlates with cellular proliferation index in desmoplastic ameloblastomas (DA), peripheral ameloblastomas (PA) and ameloblastic carcinomas (AC), and to compare with that previously reported for solid (SA) and unicystic (UA) variants of ameloblastoma. Immunohistochemistry was performed for syndecan-1 and Ki-67 in seven ameloblastomas (four DA and three PA) and three AC. Expression of syndecan-1 was related to the histological subtype of tumors and, in the case of malignancy, to lower expression levels observed in AC (22.5%) than in PA (47.5%) or DA (77.5%) (P < 0.05). Syndecan-1 expression correlated inversely with Ki-67 proliferative index: the expression was lower in both types of ameloblastomas (1.5% in DA and 6.4% in PA) than in AC (41.2%; P < 0.05). The present results suggest that the decrease in syndecan-1 expression and increase in the Ki-67 index observed in AC is in accordance with its higher aggressiveness as compared to the rare DA and PA. Interestingly, DA had a lower proliferation index as well as the highest levels of syndecan-1 expression. These data suggest that DA differ from the other types of intraosseous ameloblastomas but more studies are necessary to better understand the role of this protein as a marker in the biological behavior of the epithelial odontogenic neoplasms.

In the present studies we analysed the main physicochemical and biological properties of the several isoforms of human pituitary follicle-stimulating hormone (hFSH). Extracts of total anterior pituitary glycoproteins from adult donors were submitted to chromatofocusing and several forms of immunoactive hFSH with isoelectric points (pI) ranging from 7.6 to 3.8 were identified. An additional isoform was detected after passing through the chromatofocusing column a 1.0 M NaCl solution (salt peak). Each hFSH isoform or pool of neighbouring isoforms (pI value 7.6-7.1, pool I, 1.5 +/- 0.13% of total immunoactivity recovered; pI value 5.9-5.3, pool II, 8.9 +/- 1.6% of total; pI value 5.0-4.7, pool III, 14.4 +/- 1.4% of total; pI value 4.5-4.1, pool IV, 54.8 +/- 4.9% of total; pI value 3.9-3.8, pool V, 3.67 +/- 0.9% of total; salt peak, pool VI, 16.8 +/- 4.8% of total) eluted as single hFSH peaks after Sephadex G-100 exclusion chromatography (apparent Mr 60,000). Even though hFSH present within each pool was recognized by a receptor preparation, the receptor-binding activity expressed as the radioreceptor assay:radioimmunoassay (RRA/RIA) activity ratio varied with the pI value of the particular hFSH isoform tested; starting from a pI value of 5.9, the receptor-binding activity of hFSH decreased from 4.25 +/- 0.28 to 1.17 +/- 0.14, as the pI value of the corresponding isoform declined. A similar trend was observed when the potency of each isoform was assessed by an in vitro bioassay.(ABSTRACT TRUNCATED AT 250 WORDS)

Our case is unique, as we found no previous reports of BPDCN presenting as a renal mass mimicking a primary renal malignancy clinically and radiologically, without the characteristic skin lesions. This highlights the importance of biopsy diagnosis of renal neoplasms.

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Pituitary gonadotrophins (follicle-stimulating hormone, FSH; luteinizing hormone, LH) exist in different molecular forms within the anterior pituitary gland and serum of several non-mammalian and mammalian species, including man. The number and relative abundance of each gonadotrophin species will depend on the specific technique utilized for their isolation, the tissue source and the physiological status of the donor. Intracellular FSH and LH from glands of rodents (hamsters and rats) and primates exhibit charge heterogeneity and therefore may be separated into several forms or iso-hormones by isoelectric focusing (IEF). These FSH and LH species differ from each other not only in their isoelectric point (pI) but also in their relative abundance, receptor binding activity, biological activity and plasma half-life. Almost all gonadotrophin species isolated from pituitary extracts have also been detected in vitro and in vivo as secreted forms. Less basic rodent LH and FSH forms exhibit low receptor binding and in-vitro biological activities; a similar trend is found in LH and FSH species isolated from glands of monkeys and humans. However, these relatively acidic isohormones have longer circulatory half-lives and higher in-vivo biological activities than less negatively charged forms. The overall pattern of charge heterogeneity of gonadotrophins varies according to the specific endocrine status of the donor. Sex steroid hormones (mainly oestrogens) and gonadotrophin-releasing hormone seem to act in concert at the pituitary level to influence the physicochemical and functional characteristics of gonadotrophins and therefore their biological expression at the target cell. The effects of these factors appear to be mediated through the incorporation of specific carbohydrate residues and/or degree of terminal sugar sulphation at co-post-translational levels. The first result of these complex interactions between the gonad and the hypothalamic-pituitary unit is the production and secretion of various types of gonadotrophin molecules in proportions according with the physiological requirements of the subject at a given time, to perform specific actions upon gonadal maturation and/or function.