Pancreatic islets and transdifferentiate into beta cells in both healthy and diabetic human and mouse pancreatic islets, a possible future source for beta cell regeneration. Pancreatic islets The pancreatic islets or islets of Langerhans are the regions of the pancreas that contain its endocrine (hormone-producing) cells, discovered in 1869 by German pathological anatomist Paul Langerhans. The pancreatic islets constitute 1 to 2% of the pancreas volume and receive 10–15% of its blood flow. The pancreatic islets are arranged in density routes throughout the human pancreas, and are important in the metabolism of glucose. There are about 3 million islets distributed in the
Langerhans cell oral mucosa of humans; the lower concentrations in oral mucosa suggest that it is not a likely source of HIV infection relative to foreskin and vaginal mucosa. On March 4, 2007 the online Nature Medicine magazine published the research letter "Langerin is a natural barrier to HIV-1 transmission by Langerhans cells." One of the authors of the study, Teunis Geijtenbeek, said that "Langerin is able to scavenge viruses from the surrounding environment, thereby preventing infection" and "since generally all tissues on the outside of our bodies have Langerhans cells, we think that the human body is equipped with an antiviral