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Biomedical subjects

E Ottaviani

Publications and source records attributed to E Ottaviani.

At least 145 records · Page 8Linked to original sources
PubMed1991

Cytotoxicity and immunocyte markers in cells from the freshwater snail Planorbarius corneus (L.) (Gastropoda pulmonata): implications for the evolution of natural killer cells.

The hypothesis that natural killer (NK) cells represent an important form of cell recognition and cytotoxicity leads to the prediction that NK-like activity should be preserved throughout phylogenetic development. This was tested in the invertebrate Planorbarius corneus. Two types of cells can be identified and separated from the hemolymph of this mollusc, i.e. glass-adherent macrophage-like spreading hemocytes (SH) and nonadherent round hemocytes (RH). Only RH are able to lyse the K-562 human target cell line in a short-term NK cytotoxicity test. This NK-like activity, severely reduced after 18 h incubation at 24 degrees C, is preserved by human recombinant interleukin 2. A further analysis of P. corneus hemocytes has been performed by using several mouse anti-human monoclonal antibodies and cytofluorimetric analysis. Unexpectedly, both SH and RH react with several monoclonal antibodies, including those directed against epitopes typical of mammalian NK cells and cell adhesion molecules. On the whole, these data support the hypothesis that a primitive NK-like activity appeared early in evolution and is not shared by phagocytic cells.

Animals↗
PubMed1991

Identification of muramyl derivatives in Mollusca Gastropoda tissue.

Previous findings have demonstrated the presence of muramic acid and the lack of sialic acid in gastropod glycoconjugates from different tissues. The present study investigated the composition of muramyl derivatives in Mollusca Gastropoda tissue from the foot, mantle and periesophageal ganglia, using HRP-labeled lectins (LTA, UEA I, GSA IB4, GSA II, DBA, SBA, RCA II, WGA, PNA, ConA) and glycosidase digestion (neuraminidase, lysozyme, alpha-L-fucosidase, beta-N-acetylglucosaminidase, alpha-N-acetylgalactosaminidase). Muramyl derivatives from the tissue examined showed some differences related to the composition of the terminal disaccharides. Indeed, foot and mantle mucocytes exhibited muramic acid in a terminal position, linked to (subterminal) N-acetylgalactosamine, whereas in neuron cells muramic acid was present in an internal position and linked to N-acetylglucosamine. Diversities also occurred between foot and mantle mucocytes with respect to the receptor sugar for penultimate N-acetylgalactosamine.

Animals↗
PubMed1990

Immunocytochemical evidence of vertebrate bioactive peptide-like molecules in the immuno cell types of the freshwater snail Planorbarius corneus (L.) (Gastropoda, Pulmonata).

An immunocytochemical investigation was carried out on round and spreading hemocytes of Planorbarius corneus by using 20 antisera to vertebrate bioactive peptides. The immunotests showed the presence of alpha 1-antichymotrypsin-bombesin-, calcitonin-, CCK-8 (INC)-, CCK-39-, gastrin-, glucagon-, Met-enkephalin-, neurotensin-, oxytocin-, somatostatin-, substance P-, VIP-, and vasopressin-immunoreactive molecules in the spreading hemocytes. The round hemocytes were only positive to anti-bombesin, anticalcitonin, anti-CCK-8 (INC), anti-CCK-39, anti-neurotensin, anti-oxytocin, anti-substance P and anti-vasopressin antibodies. No immunostaining was observed with anti-CCK-8 (Peninsula), anti-insulin, anti-prolactin, anti-thyroglobulin and anti-thyroxin (T4) antibodies. As probably in vertebrates, these bioactive peptides may modulate immuno cell function.

Animals↗
PubMed1990

N-acetylmuramic acid in Mollusca Gastropoda: a histochemical and immunocytochemical study.

The presence of N-acetylmuramic acid in glycoconjugates in various mollusc tissues was investigated by histochemical and immunocytochemical techniques. The tissues studied included foot, mantle, digestive gland, ganglia and haemocytes of Helix aspersa, Planorbarius corneus, Murex brandaris and Trunculariposis trunculus. Sialic acid residues were found to be absent. The possibility that N-acetylmuramic acid replaces sialic acid in acid glycoconjugates of gastropods with similar properties is discussed.

Animals↗
PubMed1990

Presence of ACTH and beta-endorphin immunoreactive molecules in the freshwater snail Planorbarius corneus (L.) (Gastropoda, Pulmonata) and their possible role in phagocytosis.

The presence of ACTH and beta-endorphin immunoreactive molecules in the cell-free hemolymph and in the hemocytes of the freshwater snail Planorbarius corneus were demonstrated by immunocytochemistry and RIA tests. Only spreading phagocytic hemocytes were positive, in contrast with other hemocytes devoid of phagocytic activity, i.e., round hemocytes. These data were confirmed by flow cytometry. Another cell type with marked phagocytic activity, i.e., digestive cells of digestive gland, were also positive to anti-ACTH. Corticotropin-releasing factor immunoreactive molecules were found in the cell-free hemolymph and hemocytes, by RIA. Our data suggest that cells with phagocytic activity, the oldest immune response, may represent a suitable model to unravel the tangled web of the common ancestor of the immune and the neuroendocrine systems.

Adrenocorticotropic Hormone↗
PubMed1989

Immunodetection of haemocyte subpopulations by N-acetylmuramic acid antibody in Planorbarius corneus (L.) (Gastropoda, Pulmonata).

The cell subpopulations in the haemolymph of Planorbarius corneus were distinguished by means of flow cytometry. An antibody against N-acetylmuramic acid was prepared and used as a cellular marker to recognize the cell types forming the subpopulations. The spreading haemocytes showed a positive reaction for anti-N-acetylmuramic acid; round haemocytes gave a negative reaction.

Animals↗
PubMed1989

Plasma lipoproteins, tissue cholesterol overload, and skeletal muscle apolipoprotein A-I synthesis in the developing chick.

In the present study we investigated the changes of plasma lipids, lipoproteins, and tissue lipids that occur during the late embryonic life (5 days before hatching) and the postnatal period (0, 2, 7, 14, and 30 days after hatching) of the chick. The chick emerges from the egg with extreme hypercholesterolemia associated with a high level of cholesterol-rich VLDL + IDL. The density gradient profile of plasma lipoproteins showed that the concentrations of VLDL + IDL and LDL decreased during the first week of postnatal life, whereas HDL concentration increased sharply around hatching and remained stable afterwards. All plasma lipoprotein classes of the newborn chick (2 days from hatching) were enriched in cholesterol and cholesteryl esters; 2 weeks after hatching, the relative amount of cholesterol and cholesteryl esters decreased. In the newborn chick, plasma VLDL + IDL consisted of two populations of cholesteryl ester-rich lipoproteins: the main one (designated apoB-VLDL) contained apoB and no apoA-I; the other (designated apoA-I-VLDL) contained predominantly apoA-I. In the newborn chick there was an accumulation of free and esterified cholesterol in the liver and, to a lesser extent, in the skeletal muscle. These cholesterol deposits were depleted 2 to 7 days after hatching. The depletion in skeletal muscle was preceded by and associated with a striking increase in the synthesis of apoA-I in this tissue, as demonstrated by immunological methods and apoA-I mRNA measurements. In addition, apoA-I-containing HDL were secreted in vitro by explants of skeletal muscle of the newborn chick. The synthesis of apoA-I in the skeletal muscle decreased to the level found in the adult animal 1 week after hatching. It is likely that the rise of HDL and apoA-I in plasma observed 1-2 days after hatching reflects the production of apoA-I-containing HDL by skeletal muscle. We suggest that the cholesterol overload in skeletal muscle might stimulate the production of apoA-I which, in turn, would promote the removal of cholesterol from this tissue. The hypothesis that metabolic stimuli play a role in inducing apoA-I synthesis in skeletal muscle is supported by the observation that feeding the newborn chick a diet rich in proteins and lipids and free of carbohydrates delays the fall of apoA-I mRNA which normally occurs 1 week after hatching.

Animals↗
PubMed1988

Lectin binding to neurosecretory cells of Helicella virgata (Gastropoda, Pulmonata).

The neurosecretory cells of Helicella virgata, irrespective of specific neurosecretory activity, react in the same manner against each lectin (concanavalin A, soybean agglutinin, Pisum sativum agglutinin, Ricinus communis agglutinin I, wheat germ agglutinin, Ulex europaeus agglutinin I), but with different intensity. The possible neuromodulatory function is discussed in relation to surface reactivity to lectins.

Animals↗
PubMed1987

Histochemical research on metabolic pathways of glucose in some species of Mollusca Gastropoda.

The metabolic pathways of glucose were studied by histochemical reactions in some species of gastropods living in different habitats. The glycolytic pathway is histochemically indicated by positive results for glucose-6-phosphate isomerase, fructose-1,6-biphosphate aldolase, glyceraldehyde-3-phosphate dehydrogenase, and D-lactate dehydrogenase. The enzymes of the Krebs cycle gave different responses: isocitrate dehydrogenase and L-malate dehydrogenase were positive, whilst succinate dehydrogenase was constantly negative. Malate synthetase activity was also demonstrated. Despite L-glutamate dehydrogenase is undetectable, the presence of transaminase indicates the gluconeogenetic route. Phosphoglucomutase and glucose-6-phosphate phosphatase appear also positive. The metabolic meaning of our results were discussed.

Animals↗
PubMed1985

Effect of pollution on some freshwater species. II. Bioaccumulation and toxic effects of experimental lead pollution on the ganglia in Viviparus ater (Mollusca, Gastropoda).

The effect of lead on ganglia of Viviparus ater were studied by histochemical and histomorphological procedures. The pollution experiment should be considered a "short-time static bioassay" because of its experimental characteristics. There was considerable accumulation of lead in the ganglia as determined by atomic absorbance (A.A.S.). The cytological damage principally affected the neuronal cell bodies which undergo degenerative processes. The most serious cytopathological changes occurred in the following sequence: nuclear damage leading to pyknosis; nucleolar damage until disappearance; changes in Nissl bodies, at times forming a uniform mass. These cytological disorders led to markedly altered protein synthesis. Nerve fibers and neuroglia did not appear affected by lead exposure, even at higher doses. Membrane enzymes, phosphorylase, NADHDH, NADPHDH and SDH activities were decreased, whereas D-LDH, G-6-PDH, G-6-Pase and MAO activities increased. GDH was unchanged. Changes in polar lipid composition were also observed with an increase of phospholipids and a decrease of sulpholipids and cerebrosides.

Animals↗
PubMed1983

The blood cells of the freshwater snail Planorbis corneus (Gastropoda, Pulmonata).

A study of the morphology and behaviour (cell adherence and spreading, in vitro phagocytosis and rosette formation) of blood cells of Planorbis corneus, revealed the presence of two cell types: the spreading haemocyte and the round haemocyte. Results obtained with vinblastine confirmed that these cell forms are distinct cell types and not different maturational stages of a single cell type.

Animals↗
PubMed1982

Effect of pollution on some freshwater species. I. histochemical and biochemical features of lead pollution on some organs of Viviparus viviparus L. (Mollusca Gastropoda).

Experimental lead pollution was studied in some organs (foot, mantle and digestive gland) of Viviparus viviparus L. The amount of lead contained after 48h, 96 h and one week of pollution were established using an atomic absorption spectrophotometer. On the basis of physicochemical determination, it turns out that lead is mainly concentrated in the mantle. The biochemical tests (cholesterol, sulpholipids and phospholipids) were aimed at evaluating the lipids involved in the membranes. The histochemical research was carried out chiefly to evaluate the modifications of polysaccharides and proteins. Some hydrolytic enzymes (Na+ and K+ dependent ATPase) and some ooreductive enzymes (NADH+ and NADPH+ dependent diaphorases, D-lactate dehydrogenase, succinate dehydrogenase and glucose-6-P-dehydrogenase) were also tested. The digestive gland is the most severely damaged organ as proved by histomorphological and biochemical analyses.

Animals↗
PubMed1982

The digestive apparatus of Murex brandaris (L.) and Trunculariopsis Trunculus (L.).

The histomorphology and histochemistry of the digestive apparatus of Murex brandaris and Trunculariopsis trunculus has been studied in order to clarify the structural features of the digestive tract and the physiology of digestion in these species. Biochemical analyses of polar lipids and of some enzymatic activities were also carried out on the connected glands. (salivary, "framboisé", Leiblein and digestive). Digestive enzyme production is not present in the stomach and intestine. These enzymes are produced not only by the connected glands, but also by a specialized epithelial cell type (granular cell) present in the oesophagus and in the rectum. Absorbtion activity is demonstrable at the level of the rectum.

Animals↗
PubMed1982

Neurosecretory cells in the central nervous system of Helicella virgata (Gastropoda, Pulmonata).

The central nervous system of Helicella virgata was first investigated with chrome-haematoxylin phloxin and paraldehyde-fuchsin techniques for the detection of neurosecretory cells. With the alcian blue/alcian yellow staining method five cell types were identified within the class of Gomori-positive cells. It was further established that the group of Gomori-negative cells distributed in the right parietal and left parieto-visceral ganglia reacts positively with alcian blue/alcian yellow method. These cells are to be included in the Yellow Green Cells type.

Animals↗
PubMed1981

Lipid composition in ganglia of Mollusca.

The aim of the present study is to ascertain lipid composition in the ganglia of Mollusca. Nervous ganglia in the periesophageal ring dissected from Helix pomatia, Lymnaea stagnalis, Murex trunculus and Murex brandaris were studied by biochemical and histochemical procedures. Glycosphyngolipids are present mainly as sulpholipid; sialic acid and gangliosides are not present as revealed by Svennerholm's reaction and TLC separation. The phospholipid/cholesterol ratios are: 0.47 (Helix), 0.42 (Lymnaea), 0.86 (Murex brandaris) and 1.01 (Murex trunculus).

Animals↗