Selective binding of fluoresceinated-avidin to A-cells of sectioned pancreas.

Fluoresceinated-avidin (FITC-avidin) was observed to bind specifically to a subset of pancreatic islet cells in sections of both human and rat pancreas. FITC-avidin binding was inhibited by excess unlabeled avidin, and by biotin, but not by glucagon, somatostatin, or insulin. Labeling of islets with anti-insulin, anti-glucagon, anti-somatostatin, and anti-human pancreatic polypeptide antibodies showed the avidin binding subset to correspond to islet cells identified by anti-glucagon antibody. Conversely, avidin reacted with no insulin, somatostatin, or cells containing HPP. We conclude that avidin localizes specifically to A-islet cells. Binding may be to a biotin-containing enzyme within the A-cells, but the precise molecular site of binding is currently unidentified.

Case report 701: Prostaglandin E1 (PGE1) periostitis.

A case of periosteal new bone in a newborn is presented. The periostitis resulted from long-term therapy with PGE1, which was administered to maintain patency of the ductus in a neonate with ductal-dependent cyanotic congenital heart disease. The features of PGE1 periostitis and the differential diagnosis are reviewed.

Jaccoud's arthropathy and inflammatory bowel disease.

A patient with longstanding ulcerative colitis developed an arthropathy of the hands and feet characterized by subluxations at the metacarpophalangeal and metatarsophalangeal joints without apparent osseous erosions. This could be a case of Jaccoud's arthropathy associated with inflammatory bowel disease.