PubMed Health⌕ Search

Biomedical subjects

S Franceschetti

Publications and source records attributed to S Franceschetti.

62 records · Page 4Linked to original sources
PubMed1980

Effect of L-5HTP and drugs acting on serotonin metabolism in various myoclonic syndromes.

Ten patients affected by various myoclonic syndromes were tested with drugs acting on cerebral serotonin metabolism and with clonazepam (CZP). After L5HTP or serotonergic drugs administration a clear cut improvement was observed in the 2 patients affected by Ramsay-Hunt syndrome, while the patients with myoclonic epilepsy have shown no effect (3 cases) or negative response (1 case). Methysergide was active only in 1 patient affected by progressive erratic myoclonus who had a striking worsening of clinical picture. The main side effects observed were: gastrointestinal distress (L5HTP--4 patients, fenfluoramine--2, quipazine--1, methysergide--2) and cutaneous rash (quipazine--1 case). These results support the possible implication of the serotonergic system in the pathogenesis of myoclonus other than post-anoxic.

5-Hydroxytryptophan↗
PubMedDate not supplied

Changes in excitability of CA1 pyramidal neurons in slices prepared from AlCl3-treated rabbits.

Intracellular recordings in 'in vitro' hippocampal slices, prepared from intracisternally AlCl3-intoxicated rabbits, were obtained from 43 CA1 pyramidal neurons. The experiments were performed 12-20 days after aluminum administration. The electrotonic length was significantly shorter than that of 33 control neurons, in agreement with morphological evidence of an Al-induced dendritic impairment. Both postsynaptic and Ca2(+)-dependent K+ hyperpolarizing potentials were also found to be significantly decreased, with reciprocal enhancement of excitatory postsynaptic potentials and depolarizing after-potentials. The former finding is ascribed to a selective neurotoxic effect of aluminum on GABAergic interneurons; the latter can be accounted for by an Al-induced increase in cyclic AMP, which is known to block the Ca2(+)-activated K+ conductance responsible for after-hyperpolarizing potentials. It is concluded that aluminum can exert its epileptogenic effect through multiple neurotoxic mechanisms involving membrane electrotonic properties, K+ conductances, and synaptic influences, thus resulting in a neuronal hyperexcitable state. Such changes are detectable in the early stages of the Al-induced encephalopathy, when there is only slight evidence of cytoskeleton alterations (i.e., neurofibrillary degeneration).

Action Potentials↗
PubMedDate not supplied

Ethosuximide plasma concentrations: influence of age and associated concomitant therapy.

The relationship between oral dose and plasma concentration of ethosuximide was evaluated retrospectively in 198 epileptic patients aged 2.5 to 34 years. Age appears to be a major factor in determining the ethosuximide plasma level/dose (L/D) ratio. Children younger than 10 years had men L/D ratios significantly lower (p less than 0.0003) than adolescents (10 to 15 years of age) and adults (16 to 34 years of age). Associated antiepileptic therapy reduced the ethosuximide L/D ratio: mean ethosuximide L/D ratios were significantly lower in patients also taking primidone (p less than 0.0005) or valproic acid (p less than 0.02). The correlation between the dose of ethosuximide administered and the plasma concentration was significant in the 3 age groups considered (p less than 0.0004), but the wide scattering of individual plasma concentrations makes it impossible to predict what plasma concentration of ethosuximide will be obtained after a given dose. For this reason, routine monitoring of ethosuximide plasma concentrations still appears to be necessary, especially in children and patients on polytherapy.

Administration, Oral↗
PubMedDate not supplied

Focal reflex myoclonus in corticobasal degeneration.

Focal reflex myoclonus was observed in a patient clinically diagnosed as affected by corticobasal degeneration. Myoclonus was not preceded by a cortical discharge and contralateral parietal components of the somatosensory evoked potentials were reduced in amplitude. No simple pathophysiological mechanism can account for all cases of focal reflex myoclonus seen in clinical practice.

Aged↗
PubMedDate not supplied

Sialidosis type I: pathological study in an adult.

Histological and ultrastructural findings observed throughout the nervous system and the extranervous organs in a case of sialidosis type I, also known as normosomatic group, are reported. The patient was a 22-year-old male with non-familial progressive myoclonus, macular cherry-red spot, moderate cerebellar syndrome and normal intelligence. Biochemical study showed an alpha-N-acetylneuraminidase deficiency in cultured fibroblasts. A complete and early autopsy was performed. Neuropathological study showed two prominent lesions: the first one was a fine cytoplasmatic vacuolation in several neurons of the cortex, basal ganglia and thalamus and the second one was a diffuse neuronal intracytoplasmic storage of lipofuscin-like pigment (LLP). As for the extranervous organs the main light and electron microscope findings were observed in the hepatocytes and in the Kupffer's cells, which showed an enlarged cytoplasm and lipopigment granules in different amount. Vacuoles containing dense lamellar bodies were found in tubular epithelial cells of the kidney. To our knowledge this is the first complete autoptic study of a case of sialidosis type I.

Adult↗