Intermediate filament expression in pituitary adenomas.

Seventy-five formalin-fixed and 18 alcohol-fixed pituitary adenomas were studied immunohistochemically using antibodies to keratin, vimentin, neurofilaments (NFs), glial fibrillary acidic protein, desmin, actin, S-100 protein and a variety of pituitary hormones. The pituitary adenoma cells were positive for keratin, vimentin and NFs (68 kDa and 160 kDa) and in a few instances there was co-expression of these three types of intermediate filaments (IMFs). The pattern of keratin-specific staining showed diffuse cytoplasmic or patchy paranuclear reactivity and of NF- or vimentin-specific staining showed fibrillar or patchy paranuclear reactivity. The patchy staining seemed to decorate the fibrous body. There was no correlation between the distribution of IMFs and pituitary hormones in pituitary adenomas except that melanocyte-stimulating-hormone-positive reactivity was limited to the NF-positive adenomas. The pattern of IMF staining did not depend on hormone production in adenomas.

Ultrastructural identification of human secretin cells by the immunogold technique. Their costorage of chromogranin A and serotonin.

We have localized secretin in a morphologically distinctive endocrine cell scattered in the epithelium covering the villi and uppermost crypts of the human duodenum and jejunum. The human secretin cell was characterized by relatively large (mean diameter 299 nm +/- 69 SD), fairly irregular granules, the majority of which showed homogeneous distribution of secretin and chromogranin A immunolabelling in a structurally homogeneous core. Other granules had a targetoid pattern due to an inner, argyrophobe, secretin-immunoreactive body surrounded by an argyrophil, chromogranin A immunoreactive mantle. These targetoid granules represent a distinctive ultrastructural marker of the secretin cell. Secretin cell granules have been shown to react with chromogranin A antibodies and Grimelius' silver, while lacking chromogranin B immunoreactivity. About 1/3 of secretin cells also showed serotonin immunostaining.

[Immunohistochemical localization of nerve terminals in the human gingiva. Use of a new neuronal marker]. / Localizzazione immunoistochimica dei terminali nervosi nella gengiva umana. Utilizzo di un nuovo marker neuronale.

The usefulness of classical techniques for sensory nerve ending detection is compromised by intrinsic limitations. The development of immunohistochemical methods has recently produced new information on the innervation pattern in different human tissues. This study presents the results obtained by use of a new antiserum, raised against a new marker of central and peripheral neurons (PGP 9.5), which selectively labels nerve fibers and neuroendocrine (APUD) cells also in human gingiva. The possible application of this method for further researches is also briefly discussed.

Serotonin-like immunoreactive cells in the pulmonary epithelium of ancient fish species.

The pulmonary mucosa of three species of ancient fish was studied immunohistochemically to show the distribution of serotonin, regarded as the main monoamine of mammalian bronchopulmonary paraneurons. Serotonin-like immunoreactive cells, dispersed through the airway epithelium as single cells, were found in all the fish species studied. They are presumably equivalent to the neuroendocrine cells reported in the lungs of mammalian and submammalian vertebrates. However, the precise role and the function of these cells remain unknown. Since the species studied belong to the most primitive extant groups of ancient fish, the present investigation suggests that serotonin is widely distributed in the lungs of the vertebrates. Several peptides, known to be specific cytochemical markers for the identification of the pulmonary neuroendocrine cells of mammals, are being investigated in the lungs of the fish species studied. They may help to trace the phylogeny of the pulmonary neuroendocrine cell system and to elucidate its function in lower vertebrates.

[Functional morphology of breast APUD cells in dysplasia and neoplastic processes]. / Funktsional'naia morfologiia apudotsitov molochnoi zhelezy pri displasticheskikh i opukholevykh protsessakh.

Histochemical and immunohistochemical methods were used to examine 29 malignant tumors (18 lobular and 11 invasive carcinomas) and 34 fibroadenomas of the mammary gland (MG). APUD cells containing serotonin, melatonin, and beta-endorphine were shown to be present in the duct epithelium of the normal MG and its pericanalicular fibroadenoma. APUD cells were detected in 21 of the 29 malignant tumours of MG. Hormonal differences of APUD cells were found in poorly and well differentiated carcinomas: the former contained serotonin, melatonin, and beta-endorphine (inhibitors of proliferation), the latter--insulin and adrenocorticotropic hormone (stimulators of cell division). Such differences in the endocrine function of MG malignant tumors are likely to be significant in the clinical course and determination of prognosis for carcinomas of various differentiation.

Localization of pancreastatin immunoreactivity in porcine endocrine cells.

Pancreastatin is a peptide isolated from the porcine pancreas and shown to inhibit insulin release. We have studied the immunocytochemical distribution of pancreastatin in three porcine endocrine tissues: pancreas, gut, and adenohypophysis. Pancreastatin-specific immunoreactivity was found in all three locations and distributed to numerous cells. In the pancreas, we performed the alternate labeling of consecutive thick (immunofluorescence) or thin (protein A-gold) sections and we observed that pancreastatin colocalizes to secretory granules of insulin and somatostatin-containing cells. The relationship of pancreastatin to chromogranin A is discussed.

Histamine in endocrine cells in the stomach. A survey of several species using a panel of histamine antibodies.

Antibodies to histamine were used to examine the localization of the amine in cells of the stomach and upper small intestine of a great variety of species, including cartilaginous and bony fish, amphibia, reptiles (lizard), birds (chicken) and a large number of mammals. In all species gastric histamine was localized in endocrine cells (invariably found in the epithelium) and mast cells (usually with an extra-epithelial localization). The endocrine cells were identified as such by immunostaining with antibodies to chromogranin A and the mast cells were identified by toluidine blue staining. Histamine-immunoreactive endocrine cells were found almost exclusively in the acid-producing part of the stomach; only rarely were such cells observed in the pyloric gland area. They were fairly numerous in the gastric mucosa of the two subclasses of fish as well as in the amphibia and reptile species studied. Here, the majority of the histamine-immunoreactive endocrine cells seemed to have contact with the gastric lumen (open type cells) and were located in the surface epithelium (certain fish only) or together with mucous neck cells at the bottom of the pits. In the chicken, histamine-immunoreactive endocrine cells were numerous and located peripherally in the deep compound glands. They were without contact with the lumen (closed type) and had long basal extensions ("paracrine" appearance), running close to the base of the oxyntic-peptic cells. In mammals, the number of histamine-immunoreactive endocrine cells in the stomach varied greatly. They were particularly numerous in the rat and notably few in the dog, monkey and man. In all mammals, the histamine-immunoreactive endocrine cells were of the closed type and located basally in the oxyntic glands. They often had a "paracrine" appearance with long basal processes. Histamine-storing mast cells, finally, were few in both subclasses of fish as well as in the amphibian species and in the lizard. They were fairly numerous in chicken proventriculus (beneath the surface epithelium), few in the oxyntic mucosa of mouse, rat and hamster, moderate in number in hedgehog, guinea-pig, rabbit, pig and monkey, and numerous in cat, dog and man.(ABSTRACT TRUNCATED AT 400 WORDS)

Argyrophilic cells in 202 human mucinous breast carcinomas. Relation to histopathologic and clinical factors.

Two hundred two human, mucinous breast carcinomas were investigated for the presence of argyrophilic granules, and these granules were found in 25% of the cases. The granules were located in the cytoplasm and were heterogeneously distributed within the tumors. Tumors with granules were otherwise morphologically indistinguishable from those tumors without granules. The recurrence-free survival was independent of the presence of granules, and no relation was found to other clinical or histopathologic factors. Tumors with granules were found to be estrogen-receptor positive, and they appear to have a slightly less aggressive growth pattern than tumors without granules, but the difference is far from being statistically significant. It is concluded that there is no convincing evidence that this group of primary breast carcinomas with argyrophilia originates from APUD cells.

Immunoassay of the neuronal and neuroendocrine marker PGP 9.5 in human tissues.

An inhibitory, coated-well immunoassay for the neurone-specific protein PGP 9.5 has been devised and used to measure the concentrations of the protein in human tissues. Concentrations of PGP 9.5 between 40 ng/ml and 10 micrograms/ml could be measured using this assay. In brain PGP 9.5 was present at 100.58 +/- 16.18 micrograms/mg protein. Of the other organs examined only kidney and testis showed significant concentrations of PGP 9.5 (3.97 +/- 0.87 microgram/mg protein and 3.25 +/- 0.36 microgram/mg protein, respectively). All other organs contained less than 2% of the brain level. The tissue levels determined by coated-well immunoassay confirmed the tissue specificity of PGP 9.5 originally determined by high-resolution two-dimensional gel electrophoresis.

Somatostatin and/or somatostatin-like immunoreactive endocrine-paracrine cells in the human prostate gland.

We demonstrated the presence of somatostatin and/or somatostatin-like immunoreactive (SSLI) endocrine-paracrine (EP) cells for the first time in the human prostate gland. Specimens from 26 prostates removed at radical cystectomies were studied using the unlabeled-antibody peroxidase-antiperoxidase technique. The SSLI cells were located predominantly in the prostatic ducts in widely scattered clusters and were mostly of the closed type. Some SSLI cells had processes that were prominent, suggesting a paracrine role. The SSLI cells were always associated with aggregates of numerous argyrophil cells. The finding of SSLI cells in the prostate gland (particularly in association with other EP cells) is circumstantial evidence that other polypeptide hormones are present. The SSLI and other prostatic EP cells may play major roles in the pathophysiology of the prostate gland and have an effect on such diverse conditions as infertility, nodular prostatic hyperplasia, and prostatic carcinoma.

Morphological and cytochemical characterization of neuroepithelial bodies in fetal rabbit lung. I. Studies of isolated neuroepithelial bodies.

Neuroepithelial bodies (NEB) in 29-day fetal rabbit lung were examined by light microscopy and cytochemistry to demonstrate their structural and biochemical properties in situ. Longitudinal sections of NEB at airway bifurcations demonstrated their chemoreceptor-like appearance. Furthermore, the cytochemical presence of serotonin, acetylcholinesterase, formaldehyde-induced fluorescence, and silver-staining properties demonstrated the neural-like biochemical properties of NEB cells. Forty-one NEB and eight single neuroendocrine cells from whole fetal lungs were examined ultrastructurally. Juxtaluminal junctional complexes composed of tight and intermediate junctions, desmosomes, and cytoplasmic filaments were demonstrated in the corpuscular-shaped NEB. Basal bodies were apparent in NEB cell cytoplasm; cilia extended from NEB cells. Dense-core vesicles (DCV) were of at least three types: type 1, type 2, and enterochromaffin type. The majority of epithelial cells adjacent to NEB in near-term airway epithelium were undifferentiated, with large amounts of glycogen. However, ciliated cells were adjacent to some small NEB and single neuroendocrine cells; mucus or Clara-type cells were not observed. NEB isolated by collagenase treatment revealed an intact organoid structure, DCV, and desmosomes and retained their argyrophilia and formaldehyde-induced fluorescence. NEB were recovered in cell fractions separated by unit gravity that had cells in clumps of four or more. One to five NEB stained with silver in cytocentrifuge preparations of control, mixed cells, whereas up to 20 intact NEB were demonstrated in the clump-containing, separated fractions. We propose that isolated NEB retain certain biochemical and metabolic properties similar to those of their counterparts in situ. Serotonin and 5-hydroxyindole acetic acid were found by high-performance liquid chromatography analysis in the fractions containing NEB, and amine precursor uptake and decarboxylation (APUD) activity were demonstrated. Moreover, muscarinic cholinergic receptors were detected, consistent with the occurrence of acetylcholinesterase in NEB. The elution profile of bombesin radioimmunoactivity substantiated that isolated fetal rabbit NEB contained this neuropeptide and that NEB were enriched by unit gravity sedimentation. These studies suggest that NEB are structurally and functionally developed before other cell types in immature airway epithelium and can be isolated as intact organoids, which retain some of their structural and metabolic integrity.

Neuroendocrine cells of the lung. An overview of morphologic characteristics and development.

The detailed morphology of pulmonary neuroendocrine (NE) cells has been defined only during the last decade. The purpose of this paper is to review the main morphologic features of the NE cells, to review the methods and techniques used for their identification, and to discuss the development and functional significance of these cells. The main emphasis is on NE cells in human lung, but where appropriate, studies in animal lungs are also included. NE cells are present in the airway epithelium of human and various animal species and occur singly as well as in clusters called neuroepithelial bodies (NEB). The general cytochemical features (common to both single NE cells and NEB) include cytoplasmic argyrophilia, fluorogenic amine content, positive staining with lead-hematoxylin, and masked metachromasia. These staining properties are similar to those found in APUD cells scattered in various tissues. More specific cell markers are immunoreactivity to peptide hormones (bombesin, calcitonin, leu-enkephalin) identified so far in NE cells of human lung, and immunoreactivity to serotonin found in both human and animal lungs. At the ultrastructural level, NE cells are characterized by the presence of cytoplasmic dense core granules (90-150 nm in diameter), which are considered the storage site of amine and peptide hormones. The distinctive feature of NEB, not found with single NE cells, is the presence of nonmyelinated nerve endings in contact with granulated cells, and positive staining for acetylcholinesterase. The single NE cells are scattered throughout the tracheobronchial epithelium, whereas NEB are found only within the intrapulmonary airways. In postnatal lungs, both the single NE cells and NEB appear concentrated in small peripheral airways. In developing human lung, the first NE cells appear at 8 weeks' gestation, when all other epithelial cells are still undifferentiated. The development and cytodifferentiation of NE cells progresses in a centrifugal direction. By the end of the glandular period, single and groups of NE cells are found along the entire length of primitive bronchial epithelium. Based on differences in the size and morphology of cytoplasmic granules, three distinct types of NE cells can be recognized. During terminal stages of development, NE cells appear in small peripheral airways and primitive saccules. The functional considerations include the possible role of NE cells as endocrine, paracrine, or receptosecretory cells involved in neurohormonal regulation of pulmonary vascular or bronchial responses, and possible function of NEB as intrapulmonary hypoxia-sensitive chemoreceptors.

Dynamics of the neuroendocrine cell--regulatory peptide system in the lung. Specific overview and new results.

We assessed the changes in argyrophil neuroendocrine (NE) cell numbers, intensity of 5-HT fluorescence, and arterial medial thickness in the lungs of neonatal rabbits under various oxygen treatments. NE cell numbers and 5-HT fluorescence in normoxic rabbits increased from 12 hr before to 1 day after birth, and NE cells declined thereafter to the 10th day. In acute hypoxic (520 mm Hg for 2-2.5 hr) 5-day-old rabbits, 5-HT fluorescence was decreased, whereas NE cell numbers and medial thickness were unchanged. Neonates hypoxic from birth had higher NE cell numbers and increased medial thickness at 3 and 5 days, whereas 5-HT fluorescence was decreased compared with that in normoxic controls. These chronically hypoxic neonates showed a dramatic drop in argyrophil NE cell numbers to below normal when they were exposed to normoxia for 1 hr, but cell numbers and medial thickness returned to normal at 4 and 24 hr, respectively. We also tested the effect of acute and chronic hyperoxia: 100% O2 for 2-2.5 hr caused a significant drop in detectable NE cell numbers, whereas 40% O2 in N2 caused no change; chronic 40% O2 in N2 caused a fivefold increase in argyrophil NE cells by day 5, and medial thickness was below normal; 5-HT fluorescence decreased in acute 100% and chronic 40% hyperoxia and was elevated in acute 40% O2.