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D Sassi

Publications and source records attributed to D Sassi.

8 recordsLinked to original sources
PubMed2002

The supramedullary cells of the teleost Coris julis (L.): a noradrenergic neuronal system.

This study, carried out on Coris julis (Labridae), is a contribution to the immunocytochemical characterization of fish supramedullary neurons. The significance of these giant cells has been debated since the beginning of the twentieth century. Our research provides the first evidence for a noradrenergic feature of this neuronal system. The possible role of supramedullary neurons as components of the autonomic nervous system is discussed. Moreover, the present results, taken together with our previous studies, surmise that this the first known case of colocalization of a neuropeptide (gastrin/CCK-like) and noradrenaline in the nervous system of teleosts.

Animals↗
PubMed1998

PDGF and TGF-beta induce cell shape changes in invertebrate immunocytes via specific cell surface receptors.

The presence of PDGF receptor-alpha- and -beta- and TGF-beta-receptor (type II)-like molecules on the plasma membranes of the immunocytes of the mollusc Mytilus galloprovincialis was demonstrated by an immunocytochemical procedure. Furthermore, the present study provides evidence that PDGF-AB and TGF-beta1 provoke cell shape changes in immunocytes via interactions with the respective receptors and that these extracellular signals are transduced along the phosphoinositide signaling pathway.

Animals↗
PubMed1998

Interactions of signaling pathways in ACTH (1-24)-induced cell shape changes in invertebrate immunocytes.

ACTH (1-24) induces cell shape changes in the immunocytes of the bivalve mollusc, Mytilus galloprovincialis. Using computer-assisted microscopic image analysis, we have found that the G protein antagonist suramin sodium, the adenylate cyclase inhibitor 2',5'-dideoxyadenosine, and the protein kinase inhibitor staurosporine inhibit this effect. The highly specific inhibitors H-89 (for protein kinase A) and calphostin C (for protein kinase C) only inhibited partially the morphological alterations. In contrast, the simultaneous action of H-89 and calphostin C completely blocked these changes. The above findings indicate that ACTH (1-24) induces cell shape changes in molluscan immunocytes via adenylate cyclase/cAMP/protein kinase A pathway, as well as the activation of protein kinase C.

Adenylyl Cyclase Inhibitors↗
PubMed1997

PDGF- and TGF-beta-induced changes in cell shape of invertebrate immunocytes: effect of calcium entry blockers.

The cellular activity of hemocytes from the marine mollusc Mytilus galloprovincialis was studied using computer-assisted microscopic image analysis. PDGF-AB and TGF-beta 1 caused changes in cellular shape and induced the immunocytes to migrate in a chemotactic manner. The effect of PDGF-AB was more potent than that of TGF-beta 1, and the responses were dose-correlated for PDGF-AB, while they were dose-dependent up to 5 pg/ml for TGF-beta 1. Moreover, the PDGF-AB response was extracellular Ca(2+)-independent, while TGF-beta 1 was Ca(2+)-dependent.

Animals↗
PubMed1995

Cytofluorometric evidence for differential genome endoreplication in the cluster neurons of Lophius piscatorius L. (Osteichthyes, Lophiiformes).

Quantitative microfluorometric evaluation indicated that, in Lophius piscatorius, the DNA content of large neurons of a cluster located at the boundary between the medulla oblongata and the spinal cord varied from 4C to more than 5000C. This finding must be considered exceptional for the nervous system of Vertebrates. DNA contents were correlated to both nuclear and animal size. Utilization of AT and GC specific fluorochromes showed that the increase in DNA content is due to differential genome amplification involving GC-rich DNA sequences.

Animals↗