pituitrin and Adenoma--Islet-Cell

A variety of cells found in the pituitary and pineal glands, sympathetic nervous system and adrenal glands, the gut, pancreas, thyroid (C-cells), chemoreceptors (type I-Cells), lungs (P-cells), skin (melanocytes) and the urogenital tract have a common origin from the neural crest. These cells are programmed for neuro-endocrine function and, as a group, can be regarded as one of the physiological control systems. They secrete a variety of amine and peptide hormones and have common cytochemical characteristics from which the term APUD cell is derived. Tumours of these cells are referred to as 'apudomas' and may synthesise not only their own hormones but also those which are normally produced by other APUD cells. The relevant physiological properties of some of the peptides which have been described relatively recently are discussed and the principal clinical syndromes produced by the APUDomas are described.

Topics: Adenoma, Islet Cell; APUD Cells; Apudoma; Cushing Syndrome; Endocrine System Diseases; Gastrointestinal Neoplasms; Hormones; Humans; Malignant Carcinoid Syndrome; Neoplasms, Nerve Tissue; Pancreatic Neoplasms; Paraneoplastic Endocrine Syndromes; Pheochromocytoma; Pituitary Neoplasms; Thyroid Neoplasms; Vasopressins; Zollinger-Ellison Syndrome

Ultrasonic examination of the pancreas is rendered difficult by the echogenic characteristics of the organ, by its depth, by the overlying gas, and by bony structures and anatomic variations. The reintroduction of gray-scale imaging promises to simplify the technique and expand its usefulness. The 75Se-/-selenomethionine scan is a reliable test when performed after effective pancreatic stimulation with a scintillation camera that permits the angulation required to separate pancreas from liver. Gallium-67-citrate may be important for both mapping inflammatory processes and imaging some tumors. Retrograde pancreatography has developed into a rather reliable and sensitive method of visualizing pancreatic duct abnormalities. Angiography remains the most reliable technique for finding small lesions, while computerized axial tomography appears a promising modality in the near future. In acute pancreatitis, gallium scanning may find a place alongside plain films, GI series, and echography. Chronic pancreatitis appears best studied by pancreatography, possibly with selenomethionine scanning as a function study and echography to find associated mass lesions. Pseudocysts are most easily located by ultrasound examination. Screening for pancreatic carcinoma is done most effectively with selenomethionine scanning when the index of suspicion is low and with pancreatography or arteriography when it is high. Echography is useful for localization for aspiration biopsy and for sequential evaluation of therapeutic response. Islet-cell tumors are best found by angiographic studies.

Topics: Acute Disease; Adenoma, Islet Cell; Adult; Female; Gallium Radioisotopes; Hormones, Ectopic; Humans; Male; Middle Aged; Pancreatic Cyst; Pancreatic Diseases; Pancreatic Neoplasms; Pancreatitis; Paraneoplastic Endocrine Syndromes; Radionuclide Imaging; Selenomethionine; Ultrasonography; Vasopressins; Zollinger-Ellison Syndrome

Topics: 5-Hydroxytryptophan; Adenoma; Adenoma, Islet Cell; Adrenocorticotropic Hormone; Calcitonin; Catecholamines; Corticosterone; Gastrins; Glucagon; Growth Hormone; Humans; Insulin; Insulin Secretion; Kinins; Pancreas; Pancreatic Neoplasms; Peptides; Prostaglandins; Secretin; Thyrotropin; Vasopressins; Zollinger-Ellison Syndrome

Topics: Adenoma, Islet Cell; Adrenocortical Hyperfunction; Adrenocorticotropic Hormone; Alkalosis; Cushing Syndrome; Electrolytes; Endocrinology; Humans; Hypernatremia; Hypokalemia; Hyponatremia; Neoplasms; Pancreatic Neoplasms; Vasopressins; Water-Electrolyte Balance