Endocrine Abstracts

Pituiatry tumors account for about 15% of all intracranial neoplasms. They arise from pituitary cell types due to both cell cycle trophic dysruptions leading to adenomatous growth, as well as a coupling of specific hormone gene over-expression. Thus, both tumor growth characteristics, as well as hormonal excess are the hallmarks of these invariably benign tumors. They may lead to both central compressive features due to mass expansion or invasion, as well as to specific clinic...

Bisphosphonates, because of their efficacy, safety and ease of administration, are accepted as first-line therapy for osteoporosis worldwide. They decrease the rate of bone resorption but have also distinct pharmacological properties including preferential uptake in the skeleton, primarily at sites with increased bone remodeling, and long-term retention in bone. There are differences among bisphosphonates both in their affinity for bone as well as in their antiresorptive poten...

Acromegaly is a disease due, almost in all cases, to a pituitary adenoma (PA) characterized by GH hypersecretion. Its prevalence seems widely variable among different geographic areas, ranging 36–151 cases ×106 of inhabitants (c.p.m.). Apart from the possible underestimation due to misdiagnosis, reliable epidemiological studies showed that the prevalence of acromegaly could be 4–5 times higher in some geographic areas than in other ones, independently by presuma...

Osteoporosis is caused by a failure of bone homeostasis. The precise molecular mechanism controlling bone homeostasis is largely unknown. Increasing evidences that neurons and neurotransmitters are intimately involved in bone remodeling shed light on a novel regulatory mechanism for bone homeostasis. Namely, like all other homeostatic functions, bone remodeling is under the control of hypothalamus. We have uncovered that leptin, an adipocyte-derived anorexigenic hormone, regul...

Background: Since signs and symptoms of pheochromocytomas are unspecific, diagnosis is crucially dependent on biochemical evidence of excessive catecholamine production. Diagnostic workup was previously based on measurement of urinary catecholamines. Subsequently it was shown that pheochromocytomas contain high amounts of catechol-O-methyltransferase (COMT), the enzyme that converts epinephrine to metanephrine and norepinephrine to normetanephrine. This metabolism occur...

Tumor-induced osteomalacia (TIO) is a paraneoplastic syndrome characterized by hypophosphatemia associated with renal phosphate wasting and low to low normal serum level of 1,25-dihydroxyvitamin D (1,25(OH)2D). FGF23 was identified as a causative factor for TIO which inhibits proximal tubular phosphate reabsorption and decreases serum 1,25(OH)2D by modifying the expression levels of vitamin D-metabolizing enzymes. This disease is cured by complete resection of responsible tumo...

Fluorescence resonance energy transfer (FRET) using genetically encoded biosensors has proven to be a powerful technique to monitor the spatiotemporal dynamics of cAMP signals stimulated by Gs-coupled receptors in living cells. In contrast, real-time imaging of Gi-mediated cAMP signals under native conditions remains challenging. Here, we describe the use of transgenic mice ubiquitously expressing the highly sensitive cAMP sensor Epac1-camps for cAMP imaging in living pituitar...

The clinical response to somatostatin analogue (SMS) treatment in acromegaly is highly variable. In unselected, previously untreated patients, biochemical control is achieved in 20–50% of patients, and mean overall tumour shrinkage has been reported to 25–40%.The somatostatin analogues exert their effects through binding to the somatostatin receptor (SSTR) localized in the cell membrane. The available analogues bind with high affinity to SSTR2,...

During the past several years the wide application of sensitive brain imaging techniques (CT, MRI) has led to an increasing recognition of asymptomatic lesions in the pituitary. Although their etiology covers a wide range of pathologies, most incidentally discovered pituitary lesions are benign adenomas, ranging in size from micro- (<10 mm) to macro- (>10 mm) adenomas. Micro-incidentalomas are very common, with a reported incidence in normal individuals of 4–20%. ...

βThalassemia Minor cases unlike Thal-Major don’t require immediate medical attention, due to effective compensatory haematopoiesis and remain transfusion independent and patients may remain metabolically deficient lowering quality of life. To impose an artificial genetic bottleneck and suppress the dispersion of Thal-minor and Thal-major mutationsas in a population early detection is the only way out. Hypocholestreloemia, Vitamin D deficiency and marginally elevated ...