1,721,238 research outputs found
Therapeutic use in endocrinology of somatostatin analogues [Uso terapeutico degli analoghi della somatostatina in Endocrinologia]
No full textThe recent availability of the long-acting somatostatin analogue, octreotide, has allowed its therapeutical use in a wide variety of human diseases, including some digestive, neoplastic and autoimmune disorders. This review focuses on the treatment of some endocrine disorders with octreotide. Evidence is accumulating that octreotide treatment is effective in improving the cure rate of pituitary surgery in acromegaly by shrinking the tumour size, and in lowering GH and IGF-I levels in the vaste majority of patients. Octreotide is also effective in ameliorating TSH-induced hyperthyroidism in patients with TSH-secreting adenomas. Moreover, octreotide has proved useful in the management of endocrine tumours of the gastroenteropancreatic tract (vipomas, glucagonomas, gastrinomas, insulinomas, and carcinoids) by reducing hormone levels and in some instances the size of the primary and/or metastatic lesions. Besides the above well-established indications there are some other potential indications (non-secreting pituitary tumours, medullary thyroid carcinoma, ectopic Cushing's syndrome, diabete mellitus, Graves' ophthalmopathy, tall children and polycystic ovary syndrome) that still await further investigation. Side-effects of octreotide, particularly the formation of gallstones, should be carefully monitored
A heuristic algorithm for master production schedule generation with finite capacity and sequence dependent setup
No full textMalattie ipotalamo-ipofisarie : note di anatomia e di fisiologia
No full textSezione del secondo capitolo di un testo di Endocrinologia Clinica indirizzato agli studenti del corso di Laurea in Medicina e Chirurgia che tratta di unità ipotalamo-ipofisaria, anatomia ed embriologia dell'ipofisi, composizione cellulare dell'ipofisi anteriore e posteriore, ormoni secreti e loro regolazione, cenni di diagnosi strumentale e di laboratorio
Craniofaringioma ed altri tumori parasellari
No full textLa ghiandola ipofisaria può essere sede di processi espansivi di natura diversa dagli adenomi che originano dalle cellule endocrine e comprendono processi patologici sia neoplastici che non neoplastici. Tra i primi il più importante per incidenza e rilevanza è sicuramente il craniofaringioma, tumore dal comportamento aggressivo che origina da residui della tasca di Rathke. Il capitolo ne tratta l'epidemiologia, l'anatomia patologica, la presentazione clinica, la diagnosi, la terapia ed il follow-up
Acromegalia
No full textIl capitolo tratta di epidemiologia, eziopatogenesi, presentazione clinica, diagnosi e trattamento dell'acromegalia, una malattia sistemica rara causata nella grande maggioranza dei casi da un adenoma ipofisario GH secernente
Ectopic acromegaly
No full textEctopic acromegaly is a rare syndrome (less than 1% of acromegalic patients) caused by ectopic growth hormone-releasing hormone (GHRH) or growth hormone (GH)-producing tumors. Its recognition is clinically important because acromegaly may be a symptom of an aggressive tumor, and different therapeutic approaches are required. Most cases are caused by either extra- or intracranial GHRH-producing tumors, whereas in rare instances the underlying disease is an ectopic GH-secreting tumor. The routine evaluation of circulating GHRH in all acromegalic patients may allow its early recognition, because plasma levels greater than 0.3 ng/mL are virtually diagnostic of a GHRH-producing tumor (frequently a bronchial or pancreatic carcinoid), whereas suppressed levels may suggest an ectopic GH-producing tumor. In addition to classic imaging techniques, whole body scintiscan with labeled octreotide may help in the localization of ectopic tumors. Surgical removal of the ectopic tumor is the therapy of choice, but it is not always feasible because patients often present with widespread metastases. Patients with GHRH-induced acromegaly benefit from the administration of the long-acting somatostatin analog, octreotide, which reduces GH, IGF-I, and GHRH, and may shrink the ectopic tumor, its metastases, and the secondary pituitary enlargement
GS protein mutations and pituitary tumors : functional correlates and possible therapeutic implications
No full textIn more than one third of growth hormone (GH)-secreting pituitary adenomas, a point mutation in the gene for the α-chain of the G stimulatory protein (gsp oncogene) causes the constitutive activation of the membrane adenylyl cyclase (AC) resulting in uncontrolled cyclic adenosine monophosphate (cAMP) elevation and GH hypersecretion. Tumors expressing gsp are characterized by high membrane AC activity, elevated intracellular cAMP content, and high rates of GH release in culture medium. The AC activity is not further stimulated by GH-releasing hormone (GHRH) and other specific and non-specific agents, while it is lowered by somatostatin, as the G inhibitory protein (Gi) is normally working. Acromegalic patients bearing adenomas with the gsp mutation do not present with any obvious clinical or epidemiological distinctive features. However, they have smaller tumors in relation to their circulating GH levels, suggesting that the gsp oncogene maintains a high rate of secretory activity in vivo. Most of these patients show paradoxical GH increases to thyrotropin-releasing hormone (TRH), but none to gonadotropin-releasing hormone (GnRH) or an oral glucose tolerance test (OGTT). As with the in vitro data, these patients are not very sensitive to GHRH administration, but are sensitive to the inhibitory action of somatostatin. In our experience, only three of six patients with non-gsp-mutated tumors had lowered serum GH levels during the administration of octreotide (100 μg thrice daily for 4 years), while all of six patients with gsp-mutated tumors had serum GH levels suppressed by octreotide treatment. Such a good GH suppressibility by somatostatin makes patients with psp-mutated tumors the best candidates for medical treatment with somatostatin analogs. Copyrigh
Delayed closure of epiphyseal cartilages induced by the aromatase inhibitor anastrozole : would it help short children grow up?
No full textEstrogens locally generated from androgen precursors due to the action of aromatase play a main role in epiphyseal cartilage fusion. Treatment with an aromatase inhibitor (anastrozole, 1 mg/day for 3 yr) in a boy previously operated on for a hamartoma causing precocious puberty and presenting with advanced bone maturation and nearly fused epiphyseal cartilages, slowed cartilage fusion consenting a higher final stature than expected (164.4 cm vs 158.4 cm). It is suggested that treatment with aromatase inhibitors, alone or in combination with rh-GH, may also be useful in children with constitutional short stature in order to delay epiphyseal closure and improve the final height
Treatment of acromegaly with octreotide, a synthetic analog of somatostatin with extended action
No full textOctreotide, an analog of somatostatin, is a valid tool for the cure of acromegalic disease. This compound has a prolonged half-life and is more selective than native somatostatin in suppressing growth hormone (GH) secretion. Octreotide, 100 micrograms tid sc, decreases GH levels and improves clinical symptoms in about 85% of acromegalic patients, lowering GH to below 5 ng/ml in 45% and to below 2 ng/ml in 17-21%. Octreotide normalizes somatomedin-C (IGF-I) levels in 36-50% of patients. The increase of dosage up to 1500 micrograms/day does not appear useful in poor responsive patients. No adverse effects on other endocrine functions submitted to hypothalamus-pituitary control have been observed. A slight shrinkage of the pituitary tumor is observed in 30-50% of cases. Octreotide therapy is well tolerated and side effects are usually mild. However the possibility of colelithiasis, liver damage and diabetes mellitus in patients with glucose intolerance must be taken into account. In conclusion octreotide is a useful complement to therapeutic means now used for the treatment of acromegaly
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