Enhanced preservation of endosecretory granules in PP-cells of the canine pancreas.

Standard fixation techniques commonly used for light and electron microscopic studies have resulted in reported differences in the ultrastructural appearance of endosecretory granules of the pancreatic polypeptide (PP) cell. To clarify these differences, canine pancreatic tissues of intact and cultured pseudoislets were studied using a variety of ingredients, additives and fixatives in an effort to better preserve the endosecretory granules of PP cells. Results show that preservation of PP granules is enhanced by addition in zinc chloride (0.

Psammoma bodies in endocrine tumors of the gastroenteropancreatic axis: a rather common occurrence.

Seventeen of 204 cases of gastroenteropancreatic tumors contained psammoma bodies (8%). Of these 17, ten were B cell tumors, representing 33% of the B cell tumors studied. Three tumors of the appendix and four tumors of the small bowel also had psammoma bodies.

The juvenile human endocrine pancreas: normal v idiopathic hyperinsulinemic hypoglycemia.

Subtotal pancreatectomy specimens from 11 pediatric patients with idiopathic hyperinsulinemic hypoglycemia (IHH) were studied by conventional light and electron microscopic methods and by morphometric methods applied to sections immunostained specifically for A, B, D, and PP cells. The results were compared with corresponding studies of pancreata obtained at autopsy of 31 infants and children without abnormalities in carbohydrate homeostasis. In the control tissue, the total volume density of islet cells in live born premature infants (n = 12) was about 20%, in live born term newborn infants (0 to 1 months, n = 9) between 17.

A new in vitro model for studies of pancreatic polypeptide secretion and biochemistry.

A new model tissue (pseudoislet) is described for studies of pancreatic polypeptide (PP) secretion and biochemistry. It consists of islet-like aggregates of canine pancreatic endocrine cells which are formed and maintained on tissue culture. Immunocytochemical staining revealed that pseudoislets prepared from the duodenal end of the pancreas contained a predominance (40-60%) of F cells (the PP secreting cell).

Retrospective study of 77 pancreatic endocrine tumors using the immunoperoxidase method.

Immunocytochemical stains for various pancreatic hormones were performed on 77 pancreatic endocrine tumors from 59 patients [17 with hypoglycemia, three with glucagonoma syndrome, 18 were Zollinger-Ellison syndrome, six with WDHA (watery, diarrhea, hypokalemia, and achlorhydria) syndrome and 15 without endocrine symptoms]. In all tumors that caused either hypoglycemia or glucagonoma syndrome, insulin and glucagon were respectively identified. On the other hand, only 10 tumors from 18 patients with Zollinger-Ellison syndrome were positive for gastrin, and only four of six patients with WDHA syndrome had a vasoactive intestinal peptides-positive tumor.