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G Tagliafierro

Publications and source records attributed to G Tagliafierro.

33 records · Page 2Linked to original sources
PubMed1989

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.

APUD Cells↗
PubMed1989

Distribution of somatostatin and glucagon immunoreactive cells in the gastric mucosa of some cartilaginous fishes.

The comparative distribution of somatostatin- and glucagon-like-containing cells in the histomorphologically different gastric mucosae of the cartilaginous fishes Heptranchias perlo, Raja asterias, Scyliorhinus canicula, Squatina aculeata, and Torpedo marmorata was immunocytochemically studied to demonstrate a possible interrelationship between these endocrine cells and/or other endocrine or nonendocrine cells. In the gastric mucosa, these open-type glucagon and somatostatin immunoreactive cells show a double localization with different morphology and interrelationships. At the bottom of gastric pits, which corresponds to a proliferative zone, spindle or pear-shaped immunopositive cells appear rather numerously and are often in close proximity to each other. In gastric glands, triangular or oval immunopositive cells never in contact with each other were detected; their numeric ratio seems to be rather constant even if their numeric frequency and distribution vary according to the histomorphological aspect of selachian gastric glands. Glucagon immunoreactive cells seem to be more related to pepsinogenic cells, while somatostatin immunoreactive cells seem to be more ubiquitous. Both cell types can present basal cytoplasmic processes. From our results we can suggest a possible regulative role exerted by these two peptides on gastric secretion and cell proliferation.

Animals↗
PubMed1989

Fine structure and serotonin immunohistochemistry of the neuroendocrine cells in the lungs of the bichirs Polypterus delhezi and P. ornatipinnis.

Neuroendocrine cells (NE) occurring in the pulmonary epithelium of the fishes Polypterus delhezi and P. ornatipinnis are studied by electron microscopy and by immunostaining for serotonin which is often present in such cells in the mammalian lung. With the electron microscopy NE are found to occur single, resting upon the basement membrane and forming a narrow cytoplasmic extension towards the air lumen. They contain dense-cored vesicles of 80-165 nm which form exocytotic profiles at the level of the basal membrane. An immunoreactivity for serotonin is demonstrated for the first time in the NE of these species. The role of this mediator may involve a paracrine or endocrine function as postulated for the respiratory neuroendocrine mammalian cells. NE of the species studied are considered similar to those found within the wall of lung airways in mammals and submammalian vertebrates. Although much immunocytochemical investigations remain to be executed, they may also be included in the APUD (or DNES) cell system.

Animals↗
PubMed1988

Distribution and ontogeny of VIP-like immunoreactivity in the gastro-entero-pancreatic system of a cartilaginous fish Scyliorhinus stellaris.

The presence, distribution and development of vasoactive intestinal polypeptide (VIP)-like immunoreactivity in the gastro-entero-pancreatic system of a cartilaginous fish Scyliorhinus stellaris (L.) was investigated by immunohistochemical methods utilizing mammalian VIP antisera. In the gut VIP-like immunoreactivity was observed in both nerves and endocrine cells. Endocrine cells with VIP-like material were only detected in the intestinal epithelium while nerve fibres containing VIP-like material were noted along the whole gastro-entero-pancreatic system, being more numerous in the pyloric sphincter and in the intestinal portion. Immunoreactive nerve cell bodies were encountered in the stomach and intestinal portions localized in the submucosa and in the myenteric plexus. Intestinal immunoreactive endocrine cells were already present in the first developmental stage considered (embryos aged 4 months). They grow in number and before birth reach a frequency higher than in adults. Nerves and cell bodies showing VIP-like immunoreactivity, appear later, before birth, as a few elements in the smooth muscular layer, but only after birth their distribution and frequency are similar to those found in adults. The faint immunofluorescence shown by the immunoreactive endocrine cells and their developmental pattern, which is always different from that observed in nervous elements, suggest the presence of at least two VIP-like substances in the gastro-entero-pancreatic system of S. stellaris.

Animals↗
PubMed1988

Distribution and ontogeny of glucagon-like cells in the gastrointestinal tract of the cartilaginous fish Scyliorhinus stellaris (L.).

The ontogeny and distribution of glucagon-like cells were studied in the gastrointestinal tract of embryos, neonates, and adults of the cartilaginous fish Scyliorhinus stellaris (L.) by immunocytochemistry. The results indicate that they appear early during embryonic development, and, in some portion of the gastrointestinal tract, even before the mucosa morphological differentiation. Immunoreactive glucagon-like cells were observed both in gastric and intestinal epithelium, being present in the pyloric portion only at a particular period of its differentiation. Some differences were observed between the embryonic and adult distributive pattern. They were more numerous in proliferative zone and sometimes were situated near other endocrine epithelial cells. These findings together with available information on trophic effects of some gastrointestinal hormonal peptides suggest a possible regulatory role of this peptide on the growth and differentiation of the gastrointestinal tract.

Animals↗
PubMed1985

Distribution, histochemistry and ultrastructure of somatostatin-like immunoreactive cells in the gastroenteric tract of the cartilaginous fish Scyliorhinus stellaris (L.).

Somatostatin-like immunoreactive cells of an open type have been identified in the digestive tract of the cartilaginous fish Scyliorhinus stellaris (L.) by the use of immunocytochemical techniques. In the stomach these cells are numerous both in the corpus (neck zone and tubular glands) and in the pyloric portion (crypts). In the spiral valve, somatostatin-like cells are rare, situated in the intestinal epithelium and without any particular localization. Using semithin serial sections, somatostatin-like cells are found to be Davenport-negative and weakly positive towards the Grimelius silver reaction, and using the semithin and ultrathin technique have been identified at the ultrastructural level; their secretory granules appear electron dense, round or slightly polygonal, and with a limiting membrane tightly adherent to the core. The mean diameter varies from 250-300 nm.

Animals↗
PubMed1984

[Histochemistry and ultrastructure of gastric glandular cells of the Raja asterias delaroche (Elasmobranchi)].

The presence of different kinds of cells in the gastric tubular glands of the Elasmobranchian Cartilaginous fish "Raja asterias" was investigated by histochemical and ultrastructural methods. Our study demonstrates that the gastric glands, unlike those of the other non-Mammalian Vertebrates, contain in the distal portion, near the neck zone, the oxyntic-like cells, and in the proximal portion the zymogenic-like cells. The former presents histochemical and ultrastructural patterns similar to the Mammalian oxyntic cells, the latter to the Mammalian peptic cells. Between these two types there are always cells with intermediate aspects. These features support the presence of two different stages in the secretory activity: at first the gastric tubular cell is implicated in the secretion of hydrochloric acid, later on, in the secretion of pepsinogen.

Animals↗
PubMed1983

Immunocytochemical localization of secretin-like cells in the digestive tract of the ascidian Halocynthia papillosa.

The digestive tract of the ascidian Halocynthia papillosa was studied by means of both immunofluorescent and immunocytochemical methods. In the esophageal epithelium there are immunoreactive secretin-like (S2) cells, which are at the same time serotonin-containing cells. In the gastric and intestinal epithelia, immunoreactive (S1) cells are present which contain exclusively secretin-like substances. On the basis of the comparison between the gastric morphology of H. papillosa and that of other ascidians (styelids) it is possible to reach some conclusions of an evolutionary nature.

Animals↗
PubMed1976

[Morphological and histochemical aspects of the argentaffin and argentophilic cells in the gastric mucosa of Scyliorhinus stellaris and Scyliorhinus canicula].

Using histological and histochemical methods for the identification of biogenic amins, phenolic and indolic groups, and of substances with a proteine and carbohydrate nature, it has been possible to identify at least five types of endocrine cells in the gastric mucose of Scyliorhinus stellaris and Scyliorhinus canicula. One of these, a type I cell, localised mainly in the piloric portion, shows morphological and histochemical characteristics which are perfectly comparable with those of the enterochromaffin type found in the gastro-intestinal tract of mammals. On the other hand, the four remaining cellular types are more difficult to define; three of these latter are present solely in the pyloric mucose, i.e., (a) type II cells with slightly fluorescent and metachromatic granules, with a positive reaction to the Grimelius test and to proteine test, and completely negative and argentaffin methods, (b) type III cells with non-fluorescent granules, but metachromatic and postive to argentaffin methods, and (c) type IV cells with slightly (argyrophilic) granules, strongly metachromatic and positive to the PAS test and to the tryptophan test, respectively. Types II and IV have been hypothetically correlated with the G and D cells, respectively, of mammals. The fifth cellular type, present solely in the central portion of the stomach has exclusively argyrophilic granules. This latter cellular type is considered similar to the ECL type, mammalian cell. No hypothesis, however, has yet been ventured with respect to the cells belonging to the third group.

Animals↗
PubMedDate not supplied

Apoptosis, cell proliferation and serotonin immunoreactivity in gut of Liza aurata from natural heavy metal polluted environments: preliminary observations.

In the present paper, the effect of natural environment non-lethal heavy metal concentration on cell renewal of Liza aurata intestinal epithelium, was studied by the TUNEL (terminal deoxynucleotidyltransferase-mediated dUTP nick end labelling) method and anti-PCNA (proliferating cell nuclear antigen) immunohistochemistry, in order to detect, respectively, apoptosis and cell proliferation. In addition, the presence and distribution of the cell renewal regulator, serotonin, was immunohistochemically investigated. In order to reduce variability, only immature specimens were considered. The results indicated that in the control specimens from non-polluted areas, the PCNA immunoreactive nuclei of the proximal intestinal epithelium were only located at the bottom of the intestinal folds, together with a few TUNEL-positive nuclei, and goblet mucous differentiated cells. In the specimens from polluted areas, the number of PCNA immunoreactive cells was greatly enhanced, and they extended along the mid portion of the intestinal folds; the number of TUNEL-positive nuclei was enhanced as well, but they were almost exclusively detected in the third apical portion of the intestinal folds. Serotonin immunoreactive nerve elements were more frequently detected in the intestinal wall of L. aurata specimens from polluted areas, and besides that, some serotonin immunoreactive endocrine cells were also present. Variations in distribution and frequency of TUNEL-positive nuclei, PCNA immunoreactive nuclei, and serotonin immunoreactivity put in evidence an alteration of cell renewal with an enhancement of cell proliferation, probably leading to morphological intestinal fold changes.

Animals↗
PubMedDate not supplied

Presence and distribution of serotonin immunoreactivity in the cyprids of the barnacle Balanus amphitrite.

In this work, the presence and distribution of serotonin in the cyprid of the barnacle Balanus amphitrite were investigated by immunohistochemical methods. Serotonin-like immuno-reactive neuronal cell bodies were detected in the central nervous system only. Various clusters of immunoreactive neuronal cell bodies are distributed in the brain (protocerebrum, deutocerebrum, optical lobes), and at least, four pairs of neuronal cell bodies were detected in the centrally positioned neuropil of the posterior ganglion. Rich plexuses of immunoreactive nerve fibers in the neuropil area were also observed. Furthermore, bundles of strongly immunoreactive nerve fibers surrounding the gut wall were localized, and immunoreactive nerve terminals in the antennules and compound eyes were observed. These data demonstrate the presence of a serotonin-like immunoreactive substance in the barnacle cyprids; furthermore, its immunolocalization in the cephalic nerve terminals allows us to postulate the involvement of this bioactive molecule in substrate recognition during the settlement process.

Animals↗
PubMedDate not supplied

PACAP in developing sensory and peripheral organs of the zebrafish, Danio rerio.

The anatomical distribution of PACAP-like immunoreactivity was investigated in sensory and peripheral organs of the zebrafish, Danio rerio, during the pharyngula, hatching and larval periods, by using indirect immunofluorescence methods. First PACAP-like immunoreactive (ir) elements appeared during the pharyngula period, at 24 hours post fertilization (hpf), within the most superficial layer of the retina and the dorsal aorta. At 48 hpf, additional ir cells were found in the olfactory placode and esophagus. At 72 hpf (hatching period), PACAP-like immunoreactivity was first detected in the ganglion cell layer of the retina, the otic sensory epithelium, pharyngeal arches, swim bladder and pancreatic progenitor cells. During day 5 of larval development, new groups of ir cells appeared in the liver, whereas no ir elements were observed in the olfactory placode. Subsequently, at day 13 of larval development, additional ir elements were found for the first time in some gut epithelial cells while those previously observed in the retina and otic sensory epithelium were absent. The transient expression of PACAP-like ir material in sensory organs suggests that the peptide could be implicated in neurotrophic activities and neurosensorial connections in the migration and/or differentiation processes. The appearance of PACAP-like ir elements in peripheral organs at different developmental stages, indicates that this peptide could be involved in the control of more specific functions as soon as these peripheral structures begin to operate.

Animals↗