PubMed Health⌕ Search

Biomedical subjects

S Fasulo

Publications and source records attributed to S Fasulo.

36 records · Page 2Linked to original sources
PubMed1992

Ultrastructure and immunocytochemistry of the neuroepithelial bodies in the lung of the tiger salamander, Ambystoma tigrinum (Urodela, Amphibia).

Light and electron microscopy of the lungs of Ambystoma tigrinum (Urodela) revealed a relatively complex pattern of the neuroendocrine (NE) cells. In the apical parts of smaller septa single NE cells not associated with nerve fibres were covered and surrounded by pneumocytes. The larger septa possessed small areas of ciliated epithelium, in which the NE cells were grouped in a form of neuroepithelial bodies (NEB) consisting of 3-5 cells and covered by goblet cells. NE cells possessed a large nucleus with patches of condensed chromatin, clear cytoplasm, and membrane-bound vesicles of variable morphology and size, containing an electron dense interior surrounded by a lucent space. The size of these dense core vesicles (DCV) ranged from 70-140 nm, while rarely the larger ones exhibited a diameter of 300-600 nm. In some NEB a second type of NE cells was observed for the first time in an amphibian species: these cells communicated with the air space and exhibited on their surface microvilli and a single modified cilium with a 8 + 1 microtubule arrangement. Their cytoplasm contained two types of DCV: dense core granules with a diameter of 140-260 nm and vesicles 320-700 nm in diameter with a moderately electron dense interior. The NEB were associated with intracorpuscular, sensory nerve terminals morphologically afferent and efferent. By immunocytochemistry, the NE cells revealed the presence of serotonin, met-enkephalin, and leu-enkephalin. A paracrine and chemoreceptor role is proposed for NEB of Ambystoma tigrinum.

Ambystoma↗
PubMed1992

Developmental regulation of lectin-binding patterns in Paracentrotus lividus gonads, gametes, and early embryos.

By use of several lectins (ConA, WGA, SBA, GS I, PNA), a study was carried on gametes and developing embryos of the sea urchin Paracentrotus lividus, to investigate developmental changes in cell surface, leading to changements in cell-environment interactions. ConA, WGA, and SBA, with high affinity, bind to the vitelline membrane of unfertilized eggs, while PNA labelling at the same site is weak; GS I-binding is only present in the cytoplasm and cortical region of the unfertilized eggs. Immediately after fertilization, no ConA-binding is present in the membrane, while WGA- and SBA-binding molecules are located in the fertilization layer. In zygotes, 40 min after fertilization, ConA affinity sites were again present in both cytoplasm and cortical region. During cleavages and gastrulation, ConA binds to the blastomere cytoplasm and cortical region, to the intercellular matrix, and to the cytoplasm of mesenchyme cells. WGA binds to the cortical region of cleaving blastomeres, including the hyaline layer, up to the unhatched blastula. Then it labels the gastrula inner and outer surfaces. SBA binds to the blastomere membranes; no GS I- and PNA-binding was detected during embryonic development. Sperms are bound by all the lectins, except GS I. Mannose and glucose conjugates are the most represented throughout the whole development of P. lividus, and their origin and locations are developmentally regulated. Galacto-residues are scarcely represented or are masked by other terminal sugars (e.g. sialic acid), and become functional during particular developmental events (cell movements).

Animals↗
PubMed1990

Serotonin-like immunoreactivity in the epidermal club cells of teleost fishes.

The present immunocytochemical study concerns the distribution of serotonin in the epidermis of three species of teleost fish. Serotonin-like immunoreactivity was found in the club cells of Heteropneustes fossilis and Carapus acus but not in those from the sea eel Conger conger. This study is the first immunocytochemical identification of serotonin in the club cells of teleost epidermis. By comparing data from the literature (Zaccone et al. 1986, 1987, 1988) regarding the occurrence of serotonin and GRP/bombesin in the exocrine sacciform gland cells of piscine skin, it is worthy mentioning here that the serotonin contained in the club cells of the species studied may have the ability to affect the pheromonal or other possible functions of these cells. The presence of serotonin in these systems has been correlated with the capacity of the exocrine glands of fish skin to secrete, ectopically, amine messengers in contrast to those produced eutopically i.e. in the neuron-paraneuron system in some vertebrates (Fujita et al. 1988).

Animals↗
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

Localization of calmodulin positive immunoreactivity in the surface epidermis of the brown trout, Salmo trutta.

Calmodulin is a Ca2+-dependent modulatory protein which is required in the general regulation of a large number of key processes of cellular metabolism. In the present study, the localization of calmodulin positive immunoreactivity in the epidermis of the brown trout, Salmo trutta was investigated using a specific mouse monoclonal antibody to calmodulin of IgG2 class. The immunoreaction was found only in the superficial epithelial cells that constitute the main histological site for the production of calmodulin positive substances. Because of its distribution, this protein might have a physiological significance in the activation of the microvillar skeleton and in the control of the permeability of the skin epithelium.

Animals↗
PubMed1989

Immunohistochemical localization of VIP and Met-enkephalin in the rabbit submandibular and sublingual glands.

The existence and distribution of vasoactive intestinal polypeptide (VIP), and Met-enkephalin pentapeptide were investigated by means of the peroxidase-antiperoxidase (PAP) technique in rabbit submandibular and sublingual glands. In the submandibular gland, VIP immunostaining was observed in some peripheral acinar cells, while in sublingual one VIP positive fibres surrounded semilunes. Ductal cells of both glands were also reactive. These findings suggested a role of VIP in regulating volume and composition of salivary secretion.

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↗
PubMed1987

Lectin-binding pattern on the surface epidermis of Ambystoma tigrinum larvae. A light- and electron-microscopic study.

The surface epidermis of Ambystoma tigrinum larvae was examined at the light- and electron-microscope levels using five different lectin conjugates as probes for the detection of sugar residues on the cell membranes. Concanavalin A (Con-A), wheat-germ agglutinin (WGA), Ricinus communis agglutinin I (RCA-I), Dolichos biflorus agglutinin and soybean agglutinin (SBA) conjugates clearly labelled the surface cells, especially their apical surfaces. At electron microscopy, the labelling on plasma membranes was found to exhibit regional differences. Among the lectins tested WGA displayed a particularly characteristic binding pattern. WGA also bound to basolateral cell surfaces, including the tight-junction zone which was also stained by the RCA-I conjugate. The different labelling intensity and staining patterns obtained with the conjugates indicated the polarity of the cell surfaces. It is also assumed that the WGA staining of the basolateral membranes and intercellular spaces reflected transcellular transport, which is facilitated by acidic glycoconjugates. Other functional aspects of the polarized distribution of the lectin conjugates were also correlated with the receptor sites of certain sugar residues.

Ambystoma↗
PubMed1987

Occurrence of gastrin-releasing peptide-like and bombesin-like immunoreactivities in the epidermal sacciform gland cells of the clingfish Lepadogaster candollei.

Gastrin-releasing peptide (GRP)-like and bombesin (BOM)-like immunoreactivities were localized in the exocrine sacciform gland cells and in the surface epidermis of the clingfish Lepadogaster candollei with the use of previously characterized antibodies. The GRP-like and BOM-like peptides show resemblance to those immunohistochemically found in the dermal secretory products of the amphibian skin. The immunoreactive peptides tested in this study are unusual bioactive components of secretory sources of exocrine glands since these peptides were first demonstrated in cells of the neuroendocrine system. The results suggest that such bioactive compounds may exert regulatory activity in the absorptive processes of the skin epithelium and in influencing secretion release from exocrine complexes.

Animals↗
PubMed1986

Enzyme cytochemical and immunocytochemical studies of flask cells in the amphibian epidermis.

The localization of oxidoreductases and transport enzymes in flask cells of the amphibian epidermis was studied at the light-microscopic level. In these cells, the deposition of cytochemical reaction products was very similar to that found in fish epidermal ionocytes, thus demonstrating histochemical similarities between these two types of cells. The present histochemical results revealed high levels of activity of alkaline phosphatase (ALPase), potassium-dependent nitrophenylphosphatase (K+-p-NPPase) and carbonic-anhydrase isozymes (CA-I and CA-II) in the apical region of the flask cells, indicating that enzyme zonation may be the main site of the ion pumping.

4-Nitrophenylphosphatase↗
PubMed1985

Patterns of enzyme activities in the gills of the catfish Heteropneustes fossilis (Bloch) exposed to the anionactive detergent Na-alkyl-benzenesulphonate (LAS).

The effect of sodium-alkyl-benzenesulphonate (LAS) on the activity of the respiratory enzymes of the gills of Heteropneustes fossilis (Bloch) was investigated. After 48 h exposure, the main injury to gills was the progressive separation of the lamellae from their vascular components. The enzymes of the aerobic part of the metabolism showed a decrease in activity, whereas the activity of lactate dehydrogenase was strongly increased, thus indicating that LAS has a high potential to interfere with aerobic mechanisms; however, the mode of action of it has yet to be clearly defined.

Alkanesulfonates↗
PubMed1985

The effect of an anionic detergent on complex carbohydrates and enzyme activities in the epidermis of the catfish Heteropneustes fossilis (Bloch).

The histochemistry of various oxidative enzymes and complex carbohydrates in the epidermis of the catfish Heteropneustes fossils was investigated after exposure to sublethal concentrations of the detergent sodium alkylbenzenesulphonate. It was found that the detergent treatment was accompanied by a marked increase in the number of mucous cells which produce histochemically detectable amounts of acidic glycoproteins with a shift towards the production of O-acetylated sialic acids. The activities of mitochondrial enzymes were lost in the superficial cell layers. In contrast the activities of glucose-6-phosphate and lactate dehydrogenase increased considerably. The rise in glucose-6-phosphate dehydrogenase was correlated with the metabolic requirements for the enhanced production of mucus under stress. The changes in both enzyme activities and in the chemical composition of mucus may provide a suitable experimental model for histochemical investigations of the effects of stress induced by pollutants on aquatic organisms.

Alkanesulfonates↗
PubMed1985

Calf blood flow and vascular resistance in middle-aged and elderly hypertensives.

Hypertension is associated with increased total peripheral vascular resistance. Calf blood flow and vascular resistance in two groups of hypertensives of different age has been evaluated: 85 middle-aged hypertensives (MH) and 25 elderly hypertensives (EH), and in two groups of 20 normotensive control subjects of similar age. Calf blood flow at rest (RF) and after ischaemia (PF) was determined by strain-gauge plethysmography. Basal (BVR) and minimal (MVR) vascular resistance were obtained by the mean blood pressure (MBP):RF and MBP:PF ratio. Blood flow at rest was reduced only in EH, while PF was significantly lower in MH and in EH in comparison with the respective controls. In parallel, BVR and MVR were higher in MH and in EH compared with controls. The increase of BVR and of MVR was more evident in EH. These results suggest that in EH there is an impairment of the calf maximal vasodilatation capacity, probably due to the long duration of hypertension.

Adolescent↗
PubMed1985

Binding of concanavalin A to secretory epidermis in the fish Blennius sanguinolentus pallas: light microscopic and ultrastructural studies.

Concanavalin A (Con A) lectin from jack bean Canavalia ensiformis DC binds to alpha-D-glucopyranosyl and alpha-D-mannopyranosyl residues of the cuticular secretions (glycocalyx) attached to apical plasma membrane in the skin surface cells of Blennius sanguinolentus. The presence of Con A positive carbohydrate components is also observed in some secretory vesicles close under the apical cell membrane and in the goblet cell secretion spread over the surface of the skin. Other lectin labeling methods might offer a new tool for the cytochemical demonstration of glycoconjugates containing sugar residues on plasmic membranes of the epithelial cells. This can provide an insight into the functional significance of the carbohydrate moieties, attributable to the specialization of the cell membranes.

Animals↗
PubMed1984

Ultrastructural demonstration of alkaline phosphatase (ALP) and K+-p-nitrophenyl phosphatase (K+-p-NPPase) in the epidermal ionocytes of Blennius sanguinolentus.

Cytochemical techniques were used for the light and electron microscopical localization of alkaline phosphatase and potassium-dependent nitrophenyl phosphatase in the epidermal ionocytes of the Teleost Blennius sanguinolentus. The heavier deposition of the reaction products obtained with the different media was shown in the cytoplasmic surface of the labyrinth tubules, the apical vesicles and in intimate association with plasmic membranes. Both plasma membranes and intracellular activities are affected by the addition of specific inhibitors L-p-bromotetramisole oxalate and ouabain) to both complete and control media. The significance of the cytoplasmic localization of both the two enzymes is discussed with reference to current models of transepithelial ion transportation.

4-Nitrophenylphosphatase↗
PubMed1980

[Comparative aspects of the white body of Cephalopoda and the bone marrow of mammals].

The compared observations carried out in the white body of the Cephalopod Todarodes sagittatus and in the bone marrow of the Mammalian Rattus rattus enabled us to note, especially on the electron microscope, some resemblances among the main cellular types, and namely between leucoblasts and promyeloblasts, between proleucocytes and promyelocytes and between leucocytes and granulocytes. These resemblances are due also to the presence, in both series, of indispensable conditions to the protein synthesis in the cytoplasm. In any case one can assume that the considered series are formed by "synthetic activity cells with irreversible behaviour".

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↗