Endocrine Abstracts

Aim: Population studies have shown that basal calcitonin concentrations are below 10 ng/l in the normal population. Ten nanograms per liter is used as a diagnostic cut-off by most laboratories and patients with levels higher than this are offered a pentagastrin stimulation test to exclude medullary thyroid carcinoma. However, these guidelines were adopted from studies that used the Cisbio Immunoradiometric assay for measuring calcitonin. Most laboratories have now moved to che...

Somatostatin exerts inhibitory effects on hormone secretion and cell proliferation by interacting with five different receptors (SST1–SST5) linked to effector systems via G proteins. The receptor structural domains mediating these effects have not been identified. Since SS is the hypothalamic peptide that physiologically inhibits GH secretion, aim of this study was to investigate the molecular determinants mediating the interaction of the human SST5 with G proteins and su...

Primary hyperparathyroidism (PHPT) may occur sporadically or within MEN syndromes. It is classically thought that PHPT in MEN occurs at earlier ages than sporadic PHPT without significant differences in clinical and biochemical presentation. The aim of the study was to compare clinical and biochemical parameters between sporadic PHPT and MEN1 patients. The study included 41 genetically diagnosed MEN1 patients (14M, 27F) and 88 sporadic PHPT patients (24M, 64F) matched for age ...

Background: Apart from inactivation of the MEN1 gene, molecular events essential for tumorigenesis of the endocrine pancreas are poorly characterized. A potentially useful approach for understanding tumor progression is to study transcription factors operating in fetal pancreatic development. The Notch signaling cascade with expression of the transcription factors Hes1, Hey1, and Ascl1 plays a vital role in sustaining the balance between cell prolif...

Adrenocortical carcinoma (AC) is a rare neoplasm with poor prognosis. Medical treatment of AC is actually based on the use of op’DDD (mitotane) with or without traditional chemotherapeutic agents. Only very few information are available about the effectiveness of somatostatin analogs in AC. In human adrenal gland the expression of all five somatostatin receptor (SSTR) subtypes was previously demonstrated. A differential expression was shown in adrenal adenomas and carcino...

Vitamin D receptors are widely expressed in the skeletal system, and vitamin D and its metabolites and analogs, exert a variety of biological activities such as regulation of cellular proliferation and differentiation, cell calcium transients and energy metabolism in vitro. The latter is exerted through the control of the brain type isozyme of creatine kinase specific activity (CK), which serves to provide a readily available reservoir for ATP generation under increased worklo...

Increased RhoA/Rho-kinase (ROK) signalling is known to impair erectile function. Spontaneously hypertensive rats (SHR) over-express penile RhoA and show an impaired erectile response. We tested treatments known to inhibit RhoA activation, on erectile function and sildenafil responsiveness in SHR. SHR have been treated for two weeks with atorvastatin (5 and 30 mg/Kg/day), or with elocalcitol (30 μg/Kg/day), a vitamin D receptor (VDR) agonist. The normotensive Wistar Kyoto ...

The Estrogen Receptor (ER) is a well-studied, ligand dependent transcription factor. We have analysed, by kinetic chromatin immunoprecipitation (ChIP) assays, the mechanisms by which the ER modulates the permissiveness and transcriptional activity of the PS2 gene. Sequential ChIP assays were used to define the cyclical association of approximately 50 different proteins to the pS2 promoter. Key results from these studies are (i) that unliganded and liganded ER direct cycling on...

Introduction: Patients with diabetes have an increased risk of low-energy bone fractures (LEF). Traditional clinical risk factors and bone mineral densitometry underestimate LEF risk in diabetics. We aim to evaluate the frequency of LEF and associated risk factors in the diabetic Portuguese population.Methods: National, cross-sectional and population-based study to describe the prevalence of self-reported LEF in diabetic subjects over 40 years-old. Estim...

Background: Primary hyperparathyroidism (PHPT) is the third most common endocrine disorder. The Ca/P ratio is an accurate tool to differentiate patients with PHPT (>3.5 if Ca and P are expressed in mg/dl) from healthy subjects [1]. The reliability of this index is based on the fact that serum Ca and P are inversely related together. However, other disorders of the Ca-P metabolism, such as hypophosphoremia (HypoP), might impair the Ca/P ratio.Aim: To ...