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R Conti

Publications and source records attributed to R Conti.

At least 73 records · Page 4Linked to original sources
PubMed1964

[Rib neoplasms].

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Adolescent↗
PubMedDate not supplied

Inhibition of L-carnitine uptake into primary rat cortical cell cultures by GABA and GABA uptake blockers.

L-carnitine plays a central role in mitochondrial function and is found to be differentially distributed in the brain. We have shown before that the uptake of L-carnitine into cultured rat cortical neurones was temperature-dependent, as well as potently inhibited by factors affecting the sodium gradient as well as by molecules resembling its structure, e.g. D-carnitine, acetyl-L-carnitine and gamma-aminobutyric acid (GABA). GABA was the most potent inhibitor of L-carnitine uptake. In the present study we have found that specific GABA uptake blockers, nipecotic acid, cis-4-hydroxynipecotic (HNA), guvacine, 2,4-diaminobutyric acid (DABA) and NO 711 inhibit L-carnitine uptake even more potently than GABA. However, apart from NO 711, they caused about the same maximal inhibition, 67.4% at 50 microM for guvacine, compared to 60.5% by GABA. NO 711 was extremely potent and blocked 80.5% of the L-carnitine uptake. In contrast, the GABAA receptor agonists, isonipecotic acid and isoguvacine, or the antagonist bicuculline, at similar concentrations (50 microM), did not significantly inhibit the uptake of the L-carnitine. However, bicuculline at relatively high concentration (500 microM) was inhibitory (38%). The GABAB receptor agonist, baclofen, or antagonist, phaclofen, were ineffective, although 5-aminovaleric acid did significantly inhibit uptake at both 50 and 500 microM, causing 22 and 48% inhibition respectively. Like bicuculline, it was not as effective as GABA or the specific GABA uptake blockers. The results indicate that the uptake of L-carnitine by rat cortical neurones occurs in part by a process that can be potently inhibited by GABA and GABA uptake blockers.

Animals↗
PubMedDate not supplied

Cerebellar liponeurocytoma: immunohistochemical and ultrastructural study of a case.

The clinical, histopathological, and ultrastructural features of a cerebellar liponeurocytoma are reported. The tumor, a 3-cm mass localized in the right cerebellar hemisphere, was resected from a 61-year-old man clinically presenting with symptoms of intracranial hypertension. The lesion was composed of small, in some areas closely packed, medulloblastoma-like cells with prominent areas of lipidization phenomena. Moreover, mitoses, cellular atypia, and numerous vascular structures were focally observed. Glial and neuronal differentiation was immunohistochemically noted (glial fibrillary acidic protein, synaptophysin, neurofilaments, and neuron-specific enolase positivity). The p53 oncoprotein was detected in the majority of neoplastic cells and a moderate proliferation activity, evaluated by Mib-1 antibody, was focally appreciated. Ultrastructural study did not show evident neuritic processes, synapses, or dense core neuroendocrine granules. This cerebellar tumor previously called lipidized medulloblastoma and recently renamed cerebellar liponeurocytoma is considered an adult neoplasm with excellent prognosis histologically presenting prominent lipidized areas and, at the immunohistochemical and ultrastructural level, both glial and neuronal differentiation. The present study provides the first description of a less differentiated and histologically more aggressive form of this unusual tumor.

Antigens, Nuclear↗