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L Badiali de Giorgi

Publications and source records attributed to L Badiali de Giorgi.

9 recordsLinked to original sources
PubMed1994

Ito cell heterogeneity: desmin-negative Ito cells in normal rat liver.

The presence of desmin is used to identify Ito cells in rat liver and to evaluate the purity of separated and cultured Ito cells. Heterogeneity of the normal Ito cell population has been suggested; this could include variations in the content of cytoskeletal components. For these reasons we decided to reevaluate the use of desmin staining as a phenotypical marker of Ito cells in normal rat liver. Our approach was to combine desmin staining with identification of vitamin A (autofluorescence), lipid droplets (Sudan III), vimentin, laminin and tenascin, using cryostat sections: Immunofluorescence, double-immunofluorescence or immunoperoxidase techniques were used. All the techniques described corroborate the existence of desmin-negative Ito cells, mainly located in pericentral areas. In fact, lobular desmin-positive cells showed uneven distribution because they were more frequent in periportal than in pericentral areas. On the contrary, Ito cells identified on the basis of morphological criteria or positivity for laminin were evenly distributed. Double immunofluorescence confirmed this observation, showing nearly complete codistribution of laminin and desmin in periportal areas. Outside this area, positivity for desmin was observed only in about 50% of laminin-positive cells. Our observations suggest that desmin cannot be viewed as a phenotypical marker but rather is a differentiation marker of Ito cells, possibly indicating a specific functional state.

Animals↗
PubMed1990

Ultrastructural aspects of aging rat hippocampus after long-term administration of acetyl-L-carnitine.

In aged rats a decrease in axosomatic synapses of granule cells as well as a decrease in the number of synaptic vesicles of giant synapses was found. These phenomena were supposed to be correlated on the basis of a feed-back circuit existing at the level of the dentate gyrus. In fact the axosomatic synapses of the granules are inhibitory gamma-aminobutyric acid-ergic terminals of interneurons. Interneurons receive excitatory afferences from granules via the giant synapses of the mossy fibre collaterals. This results in a feed-back regulation of granule cell activity. The long-term administration of acetyl-L-carnitine to aged rats restores a synaptic pattern comparable to that of young rats. This effect on synaptic plasticity is transient.

Acetylcarnitine↗
PubMed1987

Light and electron microscopy investigation of glycoconjugates of rat hippocampus by lectin-gold technique.

The distribution of glycoconjugates in rat hippocampus was investigated by light and electron microscopy using gold-labelled lectins with different sugar specificities: ConA, WGA, PNA and LTA. A morphological correlation with cytochemical data was performed, and revealed the presence of intensely-stained (dark), unstained (light) and weakly-stained (intermediate) neurons both in Ammon's horn and in the dentate gyrus. The glycoconjugates are located in the nucleus, the perikaryal cytoplasm and the cytoskeleton of axons and dendrites: they are probably involved in the mechanisms of transport towards the synaptic membrane. The presence or absence of glycoconjugates corresponds to the particular ultrastructural aspect of the cell. This suggests the existence of different functional states of the neurons, probably correlated with the synthesis of neurotransmitter precursors or receptors.

Animals↗
PubMed1987

Ultrastructural aspects of ageing rat hippocampus and effects of L-acetyl-carnitine treatment.

The ageing rat hippocampus undergoes ultrastructural changes, including the loss of axosomatic synapses of the granule cells. These synapses are supposed to take part in a feed-back regulation of granule cell activity, as they are inhibitory terminals of interneurons which receive afferences from the granules themselves via the giant synapses formed by the collaterals of the mossy fibres. In the present study the authors performed a quantitative analysis of axosomatic and giant synapses at the ultrastructural level in aged rats as compared with young animals. In aged rats a decrease both in axosomatic synapses and in giant synapsis vesicles was found, giving further support to the postulated feed-back mechanism. Both young and old rats were treated with L-acetyl-carnitine, a drug which favours the synthesis of acetylcholine, the main neurotransmitter deficient in old age. In aged rats the drug restored a normal number of both axosomatic synapses and giant bouton vesicles. The authors hypothesize that the drug, by a cholinergic-type mechanism, restores the excitatory afferences to the granule whose axon would thus form normal giant boutons with the interneuron, reestablishing the feed-back regulation. In young rats the drug induced a decrease only of the axosomatic synapses, suggesting that an "over-excitation" might impair the information to the local-circuit neurons, thus interrupting feed-back control.

Acetylcarnitine↗