Regulated and adaptive in vivo insulin secretion from islets only containing β-cells.

Insulin-producing β-cells in pancreatic islets are regulated by systemic cues and, locally, by adjacent islet hormone-producing 'non-β-cells' (namely α-cells, δ-cells and γ-cells). Yet whether the non-β-cells are required for accurate insulin secretion is unclear. Here, we studied mice in which adult islets are exclusively composed of β-cells and human pseudoislets containing only primary β-cells.

Adult pancreatic islet endocrine cells emerge as fetal hormone-expressing cells.

The precise developmental dynamics of the pancreatic islet endocrine cell types, and their interrelation, are unknown. Some authors claim the persistence of islet cell differentiation from precursor cells after birth ("neogenesis"). Here, using four conditional cell lineage tracing ("pulse-and-chase") murine models, we describe the natural history of pancreatic islet cells, once they express a hormone gene, until late in life.

Pancreatic Ppy-expressing γ-cells display mixed phenotypic traits and the adaptive plasticity to engage insulin production.

The cellular identity of pancreatic polypeptide (Ppy)-expressing γ-cells, one of the rarest pancreatic islet cell-type, remains elusive. Within islets, glucagon and somatostatin, released respectively from α- and δ-cells, modulate the secretion of insulin by β-cells. Dysregulation of insulin production raises blood glucose levels, leading to diabetes onset.

Splenic Infarction in Acute Infectious Mononucleosis.

Background: The evaluation of a febrile patient with acute abdominal pain represents a frequent yet possibly challenging situation in the emergency department (ED). Splenic infarction is an uncommon complication of infectious mononucleosis, and may have a wide range of clinical presentations, from dramatic to more subtle. Its pathogenesis is still incompletely understood, yet it may be associated with the occurrence of transient prothrombotic factors.

Human colostrum and breast milk contain high levels of TNF-related apoptosis-inducing ligand (TRAIL).

Background: TNF-related apoptosis inducing ligand (TRAIL) is a pleiotropic cytokine, which plays a key role in the immune system as well as in controlling the balance of apoptosis and proliferation in various organs and tissues.

Objective: To investigate the presence and levels of soluble TRAIL in human colostrum and milk.

Methods: The levels of soluble human TRAIL were measured in human colostrum (day 2 after delivery) and breast milk (day 5 after delivery).