Eugenio De Carlo

Altered intracellular calcium fluxes in pancreatic cancer induced diabetes mellitus: Relevance of the S100A8 N‐terminal peptide (NT‐S100A8)

After isolating NT‐S100A8 from pancreatic cancer (PC) tissue of diabetic patients, we verified whether this peptide alters PC cell growth and invasion and/or insulin release and [Ca2+]i oscillations of insulin secreting cells and/or insulin signaling. BxPC3, Capan1, MiaPaCa2, Panc1 (PC cell lines) cell growth, and invasion were assessed in the absence or presence of 50, 200, and 500 nM NT‐S100A8. In NT‐S100A8 stimulated β‐TC6 (insulinoma cell line) culture medium, insulin and [Ca2+] were measured at 2, 3, 5, 10, 15, 30, and 60 min, and [Ca2+]i oscillations were monitored (epifluorescence) for 3 min. Five hundred nanomolars NT‐S100A8 stimulated BxPC3 cell growth only and dose dependently reduced MiaPaCa2 and Panc1 invasion. Five hundred nanomolars NT‐S100A8 induced a rapid insulin release and enhanced β‐TC6 [Ca2+]i oscillations after both one (F = 6.05, P < 0.01) and 2 min (F = 7.42, P < 0.01). In the presence of NT‐S100A8, [Ca2+] in β‐TC6 culture medium significantly decreased with respect to control cells (F = 6.3, P < 0.01). NT‐S100A8 did not counteract insulin induced phosphorylation of the insulin receptor, Akt and IκB‐α, but it independently activated Akt and NF‐κB signaling in PC cells. In conclusion, NT‐S100A8 exerts a mild effect on PC cell growth, while it reduces PC cell invasion, possibly by Akt and NF‐κB signaling, NT‐S100A8 enhances [Ca2+]i oscillations and insulin release, probably by inducing Ca2+ influx from the extracellular space, but it does not interfere with insulin signaling. J. Cell. Physiol. 226: 456–468, 2011.

Clinical and diagnostic aspects of cystic insulinoma

Cystic endocrine tumors of the pancreas rarely occur, and only a few cases of cystic insulinoma have been reported to date. Diagnosis of insulinoma could be difficult if the functional activity is incomplete, possibly leading to blunted symptoms of hypoglycemia and failure in the laboratory to provide evidence of hyperinsulinemia. We report a clinical case of cystic insulinoma confirmed by histological examination after surgery, characterized by a high intracystic insulin concentration despite normal blood basal levels of the hormone. New diagnostic findings from dynamic tests and cystic fluid examination have been carefully focused on.

Sudden death due to aortic rupture in acromegaly

Acromegaly, when left untreated, is associated with premature mortality which is chiefly related to cardiovascular complications. We report on a 50-year-old acromegalic woman, resistant to therapy, who died suddenly because of thoracic aortic rupture and massive bleeding into the left pleural space. The postmortem examination disclosed, nearby the point of rupture, a pulmonary abscess as well as extensive intrinsic alteration of arteries originating from the aortic arch and aorta itself, which featured microscopic cystic medial necrosis. We discussed how these aspects could be related to long-term exposition to growth hormone excess. In particular, this case gives further evidence of vascular system frailty in acromegaly.

Ovarian tumors secreting insulin.

AbstractCombined ovarian germ cell and neuroendocrine tumors are rare. Only few cases of hyperinsulinism due to ovarian ectopic secretion have been hypothesized in the literature. An ovarian tumor was diagnosed in a 76-year-old woman, referred to our department for recurrent hypoglycemia with hyperinsulinism. In vivo tests, in particular fasting test, rapid calcium infusion test, and Octreotide test were performed. Ectopic hyperinsulinemic hypoglycemia was demonstrated in vivo and hypoglycemia disappeared after hysteroadnexectomy. Histological exam revealed an ovarian germ cell tumor with neuroendocrine and Yolk sac differentiation, while immunostaining showed insulin positivity in neuroendocrine cells. A cell culture was obtained by tumoral cells, testing Everolimus, and Pasireotide. Insulin was detected in cell culture medium and Everolimus and Pasireotide demonstrated their potentiality in reducing insulin secretion, more than controlling cell viability. Nine cases of hyperinsulinism due to ovarian ectopic secretion reported in literature have been reviewed. These data confirm the ovarian tissue potentiality to induce hyperinsulinemic hypoglycemic syndrome after neoplastic transformation.

A very rare case of nonfunctioning pituitary adenoma incidentally disclosed at 18F-FDG PET/CT.

This is a case of a 48-year-old man treated with surgery and (131)I for papillary thyroid carcinoma: a follow-up (18)F-FDG PET/CT incidentally evidenced pituitary uptake, also seen in (111)In-octreoscan as increased uptake in the sellar area. MRI confirmed a pituitary mass. The patient did not show any signs or symptoms related to this lesion; 1 year later, both PET/CT and MRI findings remained unchanged. Surgery confirmed nonfunctioning benign pituitary adenoma. This single case observed in 12,873 consecutive patients scanned in our center confirms the possibility that nonfunctioning benign pituitary adenomas may be FDG-avid: uptake mechanisms remain unknown, and targeted studies are needed.

From the rat to the beta cell: a fast and effective technique of separation of Langerhans islets and direct purification of pancreatic beta cells

Abstract Isolated Langerhans islets represent a useful model for the study of the endocrine pancreas. The possibility to purify pancreatic beta cells from a mixed Langerhans islet cell population may lead towards a dedicated focus on beta cell research. We describe an effective and rapid immunomagnetic technique for the direct purification of beta cells from isolated Langerhans islets of rat. After the sacrifice of the rat, the Langerhans islets were separated by ductal injection of the pancreas with collagenase, altered to a mixed Langerhans islet cell population and incubated with conditioned immunomagnetic beads targeted to the beta cell surface. The beads were previously coated with a specific antibody against the surface of the beta cell, namely K14D10. The suspension of mixed Langerhans islet cells and immunomagnetic K14D10-conditioned beads was pelleted by a magnetic particle concentrator to isolate the bead-bound cells, which were finally suspended in a culture medium. The purified cells were immunoreactive for insulin and no glucagon-positive cells were detected at immunocytochemistry. Real Time PCR confirmed the purification of the pancreatic beta cells. This immunomagnetic technique allows a rapid, effective and consistent purification of beta cells from isolated Langerhans islets in a direct manner by conditioning the immunomagnetic beads only. This technique is easy, fast and reproducible. It promises to be a reliable method for providing purified beta cells for in vitro research.

Farmaci off-label in endocrinologia clinica: rischi e aspetti regolatori

RiassuntoLa prescrizione off-label dei farmaci è un tema di solito trattato da farmacologi o legali. Per recuperare la dovuta attenzione dei medici è invece necessario ricordare che la sicurezza del paziente rappresenta la storica “mission” della professione medica. Solo spronando tale orgoglio culturale si può pensare di recuperare il senso e l’applicazione della relativa normativa, che solitamente viene considerata come un ennesimo ostacolo burocratico alla nostra pratica clinica quotidiana.