Investigative & cell pathology最新文献

A multiplicity of regulatory molecules, messengers, are secreted by a large variety of neuronal, endocrine and paracrine cell populations. To some extent the anatomical locus of messenger production or the cytophysiological characteristics of cells producing a messenger determines its role as a hormone, transmitter, modulator or paracrine regulator. Thus, the same messenger may function as a hormone in one location and as a neurotransmitter in another. This versatility in functions makes it difficult to assign a definite physiological role to a given messenger. Our evidence for the occurrence of cell systems producing more than one type of messenger is presented. The practical and conceptual difficulties in determining definite functions of messengers leads to our present inability to examine critically well-known dogmas like the "one hormone-one cell" concept and "Dale's principle". Recognition of the fact that some cell systems do indeed produce multiple messengers provides us with valuable tools for investigating endocrine and neurocrine secretion and has far-reaching implications for studies of cell differentiation and cell pathology.

The occurrence of arylethylamines and histamine in normal and neoplastic peptide hormone producing cell types is described. The evidence for their role in hormone formation, storage and release is reviewed.

A description of the gastroenteropancreatic cells as identified by immunocytochemical techniques is presented. A functional classification of these cells is proposed where function is defined as the production of a chemical messenger be it a polypeptide or a biogenic amine. The discovery of the polypeptide-containing neurons has created a new area for investigation. This will be outlined briefly although the majority of the peptidergic-type synaptic profiles have as yet to be linked with the production of a particular polypeptide.

The usefulness of argentaffin (Masson) and argyrophil (Davenport, Sevier-Munger and Grimelius) staining methods for identification of endocrine cell types in the gastrointestinal tract and pancreas is discussed and comments are made on the techniques themselves. The applicability of silver impregnation methods in the histopathological investigations of endocrine tumours in the above-mentioned organs is outlined, and the chemical background of the silver reactions is briefly reviewed.

Immunological and biological studies have shown that many of the mammalian gastroenteropancreatic (GEP) hormones have counterparts in lower vertebrates. Hormonal localization in cyclostomes and fishes suggests that insulin was phylogenetically the first islet hormone, followed by somatostatin, glucagon and, last, pancreatic polypeptide (PP). Some of the GEP peptides are present in the central and peripheral nervous system of lower vertebrates as well as mammals. GEP hormone-like substances resembling insulin, somatostatin, glucagon, PP, gastrin, secretin, VIP, substance P and enkephalin also occur in protostomian invertebrates (Annelida, Arthropoda, Mollusca), particularly in their nervous system. These findings indicate that the vertebrate hormones may have originated in neural tissue before the development of the vertebrate line of evolution.

Localization of gut peptide hormones by immunological staining methods is known generally as "immunocytochemistry". These immunostaining techniques depend upon the correct processing of the tissue under study and careful characterization of the antisera used. Many years of research in our laboratory have enabled us to present here our approach to the application and pitfalls of immunocytochemistry in the study of gut neuroendocrinology.

The concept of nodular fasciitis and proliferative myositis as variants of the same fibroblastic disorder is supported by intermediary cases, showing simultaneous features thought to be typical of either nodular fasciitis or proliferative myositis. Various other anatomical, pathological and clinical similarities found in this study of 100 cases support such conclusions. 'Ganglion-like' cells were a distinct, but not exclusive, feature of all cases with sole, or only partial, muscle involvement.