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Biomedical subjects

A Franchini

Publications and source records attributed to A Franchini.

At least 73 records · Page 4Linked to original sources
PubMed1994

Effects of low-power 632 nm radiation (HeNe laser) on a human cell line: influence on adenylnucleotides and cytoskeletal structures.

HeNe (632 nm) irradiation (5, 15 and 30 min) of an embryonal human cell line (EUE) was used to study the short-term effects on energy charge and the rapid, energy-dependent, remodelling processes of cytoskeletal and adhesion structures. The adenosine triphosphate (ATP) concentration, tested by luminometric and high performance liquid chromatography (HPLC) procedures, is constant after 15 and 30 min of HeNe treatment; the lower phosphorylated nucleotides, i.e. adenosine diphosphate (ADP) and adenosine monophosphate (AMP), change after 30 min in opposite directions: the ADP concentration decreases by 39% whilst that of AMP increases about sixfold. The adenylate energy charge (AEC) decreases by 21.7% in treated EUE cells (AEC = 0.65) in comparison with untreated EUE cells (AEC = 0.83). In HeNe-treated cells, the remodelling of cytoskeletal and adhesion molecules becomes evident after 15 min of treatment. The following events are important: (1) modification of stress fibre assembly and increase in vinculin-containing adhesion plaques; (2) assembly and bundling of intermediate filaments; (3) increase in laminin and L-cell adhesion molecules (L-CAM) expression. The lowered energy charge in irradiated cells is related to the increase in AMP production at the expense of ADP. ATP is dynamically constant despite its requirement in short-time remodelling processes of the cytoskeletal network which are enhanced in irradiated cells.

Adenine Nucleotides↗
PubMed1994

Modification induced by ACTH in hemocyte cytoskeleton of the freshwater snail Viviparus ater (Gastropoda, Prosobranchia).

Adrenocorticotropin hormone (ACTH) is able to induce motile events in the phagocytic hemocytes of Viviparus ater by modifying the cytoskeletal components. The cell shape changes into a polarized morphology. The microfilament bundles, which, in control cells display a radial distribution from the nucleus to the cell periphery, are arranged under the plasma membrane. Moreover, on the protruded lamellipod, actin is accumulated in small, round structures. The microtubule component increases and seems to contribute to the maintenance of cell polarity. Hemocyte adhesive properties are also modified, and different localization patterns of extracellular fibronectin are observed. Cellular responses induced by the ACTH signal may be mediated by cyclic 3',5'-AMP (cAMP).

Adrenocorticotropic Hormone↗
PubMed1994

Immunocytochemical detection of endocrine cells in the gut of Viviparus ater (Mollusca, Gastropoda).

The presence of endocrine cells was investigated by immunocytochemical procedures in the gut and salivary gland of Viviparus ater, a freshwater prosobranch gastropod. The endocrine cells were scanty and both of closed and open cell type. Most of them were located in the esophagus (immunostaining with anti-gastrin, anti-insulin, anti-serotonin and anti-substance P antisera), very few in the stomach (immunoreactive only to anti-gastrin antibody) and in proximal part of the intestine (immunoreactive to anti-serotonin and anti-substance P antibodies). In the salivary glands, occasional endocrine cells scattered among the glandular cells in the adenomera stained with anti-neuropeptide Y, anti-pancreatic polypeptide and anti-somatostatin sera were detected.

APUD Cells↗
PubMed1993

Presence of several cytokine-like molecules in molluscan hemocytes.

The presence of a variety of cytokine-like molecules (IL-1 alpha, IL-1 beta, IL-2, IL-6, TNF-alpha) in the hemocytes of two molluscs, i.e., Planorbarius corneus and Viviparus ater, is reported. These molecules are present only in hemocytes with phagocytic activity. These data, together with recent reports on the presence of cytokine-like molecules in other invertebrates, suggest that cytokines are important, ancestral and functionally conserved molecules.

Animals↗
PubMed1993

CRF provokes the release of norepinephrine by hemocytes of Viviparus ater (Gastropoda, Prosobranchia): further evidence in favour of the evolutionary hypothesis of the mobile immune-brain.

The concentration of biogenic amines (norepinephrine, epinephrine and dopamine) was determined by HPLC in serum and hemocytes of the mollusc Viviparus ater following in vitro incubation of the hemolymph with corticotropin-releasing factor (CRF) for different periods of time. CRF provoked the release of norepinephrine from hemocytes into the serum, the maximum level being observed after 15 min. incubation. Moreover, immunoreactive tyrosine hydroxylase and dopamine beta-hydroxylase, i.e., the enzymes involved in biogenic amine biosynthesis, have been demonstrated in hemocytes. These findings show that in invertebrates an ancestral type of stress response, similar to that performed by mammalian hypothalamic-pituitary-adrenal axis, occurs in phagocytic hemocytes, a cell type capable of both fundamental immune and neuroendocrine responses.

Animals↗
PubMed1992

The presence of immunoreactive vertebrate bioactive peptide substances in hemocytes of the freshwater snail Viviparus ater (Gastropoda, Prosobranchia).

1. Using an immunocytochemical procedure a wide range of immunoreactive vertebrate bioactive peptides (BAPs) has been found in hemocytes of Viviparus ater: bombesin, calcitonin, CCK-8, CCK-39, GH, glucagon, insulin, oxytocin, neurotensin, secretin, serotonin, somatostatin, substance P, vasopressin, and VIP. 2. No immunostaining was observed for antigastrin and antithyroglobulin antibodies. 3. The presence of BAP-like molecules in hemocytes suggests a correlation between hemocyte and APUD cells and is evidence of a relationship between the neuroendocrine and the immune systems.

APUD Cells↗
PubMed1992

ACTH-like molecules in lymphocytes. A study in different vertebrate classes.

Immunocytochemical and cytofluorimetric studies were performed in several species of different classes (Pisces, Amphibia, Reptilia and Aves), in order to ascertain the presence of ACTH-like molecules in blood cells. Using monoclonal and polyclonal antibodies, we demonstrated that lymphocytes containing ACTH-like molecules are first detectable in anuran amphibia, and are present in lymphocytes of reptilia and aves. Taking into account previous results demonstrating that ACTH-like molecules are present in and modulate macrophage functions from molluscs to man, it is argued that a new biological role has probably been acquired by ACTH in higher vertebrates, where it is also expressed in cells belonging to the lymphocyte lineage, possibly exerting a regulatory role on antibody response.

Adrenocorticotropic Hormone↗
PubMed1992

Histomorphological and cytochemical changes induced in the liver of goldfish Carassius carassius var. auratus by short-term exposure to lead.

The cellular and molecular effects of experimental lead intoxication (5 mg l-1/24 h and 48 h) were studied in hepatocytes of Carassius carassius var. auratus. Significant lead storage was not detected by atomic absorbance spectroscopy after treatment. Cell morphology appeared only poorly impaired. A decrease of glycogen content was observed. Glycolysis, Krebs cycle and pentose shunt were altered in their enzymatic activities. Lysosomal activities were strongly increased. All enzymatic activities tested were altered 24 h after lead treatment.

Animals↗
PubMed1991

Effects of lead on hepatocyte ultrastructure in Carassius carassius (L.) var. auratus.

Subcellular modifications in hepatocytes of Carassius carassius var. auratus subjected to 24 hr and 48 hr sublethal acute lead (5mg.1-1) exposure were studied by electron microscopy. Cytological alterations were observed after 24 hr of treatment and became more evident after 48 hr. Lead induced an increase in nuclear heterochromatin and alterations in mitochondria, endoplasmic reticulum and Golgi complex ultrastructure. Glycogen granula decreased, and secondary lysosomes and lipid droplets increased. Furthermore, intracytoplasmic lumina with microvilli-bearing surfaces and numerous autophagic vacuola were observed after 48 hr of exposure.

Animals↗
PubMed1991

Vitamin E as adjuvant in emulsified vaccine for chicks.

Mineral oil was partially replaced with D, L-alpha-tocopheryl acetate (vitamin E) in bacterial and viral inactivated emulsified vaccines. Vitamin E increased the immune response to the viral antigen (Newcastle disease virus) used but not to the bacterial antigen (Escherichia coli) when its presence in the oil phase did not exceed 30%. Inoculated vitamin E may have enhanced the immune response by interacting with the immune-competent cells involved in the inflammatory reaction that followed inoculation of emulsified vaccines.

Adjuvants, Immunologic↗
PubMed1990

A preliminary histochemical study on the labral glands of Daphnia obtusa (Crustacea, Cladocera).

The gland cells located in the upper lip of the cladoceran Daphnia were studied by histochemical reactions to establish the chemical nature of some substances they synthesize. Neutral polysaccharides were found to be present, but acid glycosaminoglycans absent. Large amounts of proteins and ribonucleoproteins are also present, lipid substances were not detected. Immunohistochemical methods failed to reveal alpha-amylase in the labral gland cells, though the enzyme was detected in the cells of the intestine. The secretion products of the labral gland cells are probably glycoproteins. The results are discussed in terms of the possible roles of these substances in the animal's physiology.

Animals↗
PubMed1990

Organization of neck muscle motoneurons in the cervical spinal cord of the pigeon.

As a first step towards the analysis of the neural control of pecking behaviour in the pigeon, the cell bodies of neck muscle motoneurons were localized and their somatotopic organization in the cervical spinal cord examined. Fluorescent tracers were injected into single neck muscles and labelled motoneuron cell bodies identified. Labelled perikarya were arranged in longitudinal columns within layers VIII and IX of the ventral horn ipsilateral to the injection site. Cell bodies of neurons innervating different muscles formed distinct columns that extended mainly rostrally from the injection level. Labelling of adjoining portions of one muscle revealed one continuous column of cell bodies. Relative to the neck muscles, the motoneuron perikarya were arranged in a mediolaterally inversed pattern.

Amidines↗
PubMed1989

Characterization of glycoconjugates in an embryonic human epithelial line and changes consequent to adaptation to a hyperosmotic medium.

Cell surface and cytoplasmic glycoconjugates were characterized in embryonic human explant cells (a transformed heteroploid line) cultured in iso-osmotic medium (0.137 M NaCl) and in hyperosmotic medium (0.274 M NaCl) for 10 days in order to study the changes induced in these compounds by hyperosmoticity. Cytochemical and ultracytochemical staining selective for glycoconjugates was carried out. The following results were obtained: (1) glycoproteins, glycosaminoglycans and glycolipids are present on the cell surface and in the cytoplasm of the explant cells; (2) lectin histochemistry combined with glycosidase digestion demonstrated the presence of the disaccharides fucose-N-acetylglucosamine and sialic acid-beta-galactose as terminal sequences; (3) histophotometric evaluation of lectin labelling showed a noticeable decrease in histochemical reactivity of adapted cells; (4) plasma membrane cell coat decreased in adapted cells, which was emphasized by ultracytochemical reactions and a rearrangement of glycolipids in the cytoplasm.

Cells, Cultured↗