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BON cells are human carcinoid cells that secrete serotonin (5-HT) and various peptides. Secretion of [(3)H]5-HT by cell cultures was investigated. Acetylcholine (Ach) stimulated secretion through a somatostatin-sensitive muscarinic pathway, whereas isoproterenol was inefficient. [(3)H]5-HT secretion also was induced by Ca(2+) in the presence of the ionophore A-23187 or after digitonin permeabilization. These two processes were insensitive to stomatostatin. Ba(2+) induced an efficient somatostatin-sensitive [(3)H]5-HT secretory response. Secretion also was analyzed at the single-cell level, using carbon fiber amperometry and evanescent-field fluorescence microscopy, after labeling the secretory vesicles by transfection of the cells with a NPY-GFP construct. Both techniques revealed slow kinetics of secretory responses, suggesting that ready-to-fuse vesicles do not accumulate in these cells. Single secretory vesicles were imaged either in resting conditions or after addition of Ca(2+) ions to digitonin-permeabilized cells. The three-dimensional movements of the vesicles before exocytosis were analyzed. The mean velocity of vesicles that released their content was lower than that of silent ones. Even in the case of mobile vesicles, exocytosis often was preceded by a period of arrest lasting at least 15 seconds, consistent with a docking/priming step.

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Pancreatic ductal adenocarcinoma (PDAC) remains a major public health challenge, and faces disparities and delays in the diagnosis and access to care. Our purposes were to describe the medical path of PDAC patients in the real-life setting and evaluate the overall survival at 1 year. We used the national hospital discharge summaries database system to analyze the management of patients with newly diagnosed PDAC over the year 2016 in Auvergne-Rhône-Alpes region (AuRA) (France). A total of 1872 patients met inclusion criteria corresponding to an incidence of 22.6 per 100,000 person-year. Within the follow-up period, 353 (18.9%) were operated with a curative intent, 743 (39.7%) underwent chemo- and/or radiotherapy, and 776 (41.4%) did not receive any of these treatments. Less than half of patients were operated in a high-volume center, defined by more than 20 PDAC resections performed annually, mainly university hospitals. The 1-year survival rate was 47% in the overall population. This study highlights that a significant number of patients with PDAC are still operated in low-volume centers or do not receive any specific oncological treatment. A detailed analysis of the medical pathways is necessary in order to identify the medical and territorial determinants and their impact on the patient’s outcome.