PubMed Health⌕ Search

Biomedical subjects

F Passarelli

Publications and source records attributed to F Passarelli.

46 records · Page 3Linked to original sources
PubMed1987

Effects of single and repeated electroconvulsive shock on local cerebral glucose utilization in the conscious rat.

Local rates of cerebral glucose utilization (LCGU) were determined in adult rats submitted to electroconvulsive shock (ECS) treatment. One group of rats (n = 5) received a single ECS, a second group (n = 5) was treated once daily for 7 days. A third group (n = 5) of unshocked rats served as control. LCGU measurements were performed one day after either the single or the last ECS. Following a single ECS, most of the 45 brain regions examined exhibited lower rates of LCGU than controls, in contrast after repeated ECS treatment the metabolic activity results increased in segments of the hippocampus. The results indicate that repeated ECS treatment selectively increases metabolic rates within the hippocampus, a structure of the limbic system thought to be related to affective disorders and memory.

Animals↗
PubMed1987

Interaction between neuronal uptake inhibitors and presynaptic serotonin autoreceptors in rat hypothalamic slices: comparison of K+ and electrical depolarization.

In rat hypothalamic slices prelabeled with [3H]-5-hydroxytryptamine ([3H]-5-HT), exposure to the 5-HT receptor agonist lysergic acid diethylamide (0.1-1 microM) or 5-methoxytryptamine (0.1-10 microM) decreased in a concentration-dependent manner the release of 3H-transmitter elicited by high K+ or electrical stimulation. Exposure to the 5-HT autoreceptor antagonist methiothepin (0.1-1 microM) increased in a concentration-dependent manner the K+ stimulation-evoked overflow of [3H]-5-HT and a similar increase was observed under conditions of electrical stimulation. In contrast, exposure to the nontricyclic 5-HT uptake inhibitor citalopram (0.1-1 microM) did not modify by itself the electrically evoked overflow of [3H]-5-HT, but increased in a concentration-dependent manner the release of 3H-transmitter elicited by K+ stimulation. This effect of citalopram on transmitter release was potentiated when the endogenous stores of 5-HT were depleted by pretreatment with para-chlorophenylalanine methyl ester (300 mg/kg i.p.). Citalopram was shown previously to antagonize the inhibition by lysergic acid diethylamide of the electrically evoked release of [3H]-5-HT in rat hypothalamic slices. Yet, this inhibitor of neuronal uptake of 5-HT did not antagonize the effects of lysergic acid diethylamide when the release of [3H]-5-HT was evoked by K+ depolarization. Electrical stimulation represents a more physiological experimental model for transmitter release than exposure to high K+, and therefore the interaction between 5-HT uptake blockade and presynaptic inhibitory 5-HT autoreceptors, observed in the hypothalamus with electrical stimulation but not with K+ depolarization, remains of biological relevance.

5-Methoxytryptamine↗
PubMed1986

Study on the anticonvulsant activity of clonidine against pentylenetetrazol-induced seizures in rats: pharmacological evidence of alpha 2-adrenoceptors mediation.

The present work deals with an EEG and behavioral study of the interaction of alpha-adrenoceptor antagonists on the anticonvulsant activity of clonidine against the convulsions due to pentylenetetrazol (PTZ) in rats. Clonidine's ability (0.5 mg/kg, i.p.) to inhibit the tonic seizures and mortality induced by PTZ (75 mg/kg, i.p.) was counteracted by pretreatment with yohimbine and mianserine (10 mg/kg, i.p.). On the contrary, prazosin (10 mg/kg, i.p.) did not influence the anticonvulsant effect of clonidine. The results suggest that central alpha 2-adrenoceptors play an important role in the control of motor and EEG convulsions elicited by PTZ.

Adrenergic alpha-Antagonists↗
PubMed1983

Effects of chronic treatment with imipramine, trazodone and electroshock on the behavioural and electroencephalographic modifications induced by clonidine in the rat.

The influence of some typical and atypical antidepressant drugs on the EEG and behavioural effects of clonidine has been studied. The results indicate that chronic administration of imipramine or of electroshock led to the abolition of the behavioural depression and of the EEG synchronisation induced by clonidine. Chronic administration of trazodone was without effect. These results support the hypothesis that chronic treatment with imipramine and electroshock elicits a down-regulation of noradrenergic presynaptic receptors. These structures seem to be largely unaffected by trazodone, which could have a favourable effect on depression through its influence on beta-adrenergic receptors and on the 5-HT system.

Animals↗
PubMed1983

An EEG investigation on the effects of phencyclidine on pentylentetrazol convulsions in rats and rabbits.

The present work deals with an EEG and behavioral study of the effect of phencyclidine against the convulsions due to pentylentetrazol in rats and rabbits. The effects of phencyclidine were compared to those of phenobarbital and trimethadione. A dissociation between the behavioral and electrocortical manifestations of chemically-induced convulsions in the presence of several anticonvulsant drugs has been found.

Animals↗
PubMed1982

Effects of chronic treatment with imipramine on the behavioural and electroencephalographic modifications induced by clonidine in the rat.

The influence of repeated administration of imipramine on the EEG and behavioural effects of clonidine has been studied in the rat bearing chronic electrodes. Clonidine induced behavioural depression and EEG synchronization in control rats. Mydriasis, hyperirritability, stereotyped behaviour and EEG desynchronization were elicited by clonidine on the first and second days after discontinuation of the treatment with imipramine (15 mg/kg, i.p., daily for 21 days). On the 9th. day the animals responded to clonidine with sedation and EEG synchronization. These results support the hypothesis that chronic treatment with tricyclic antidepressant drugs changes the sensitivity of central noradrenergic neurones.

Animals↗
PubMedDate not supplied

Sentinel node biopsy for malignant melanoma: analysis of a four-year experience.

AIMS AND BACKGROUND: Sentinel node (SN) biopsy has been introduced to solve the controversy concerning the effectiveness of prophylactic lymphadenectomy in intermediate thickness melanoma. The aim of this study was to evaluate the rate of metastases, the technical details of the procedure, and the main reasons of failure. METHODS: 235 patients affected by intermediate thickness melanoma (tumor thickness >0.75 mm and <4 mm) without clinical signs of systemic spread (N0M0) were submitted to sentinel node biopsy between 1996 and 2000. Preoperative lymphoscintigraphy was routinely performed in the last 184 patients. Intraoperative mapping with gamma probe was combined with the use of vital dye for identification of sentinel nodes in the last 113 patients. RESULTS: The SN detection rate was 95.6%, with significant differences depending on the site of dissection and the use of a gamma probe. The overall rate of micrometastases was 14.7%, but relevant differences were recorded between different subgroups of patients (T2, 5.1%; T3a, 19.6%; T3b, 29%). CONCLUSIONS: Sentinel node biopsy requires a multidisciplinary approach (surgery, pathology and nuclear medicine) for reliable results. The association of vital dye and intraoperative gamma probe for sentinel node harvesting has made the procedure more effective, less time-consuming and less invasive. Failures may be due not only to surgical mistakes, but also to improper nuclear medicine procedures or inaccurate histological evaluation of SNs. Methods for histological examination of the SN are still debated and not standardized but promising results have recently been obtained with molecular oncology techniques (RT-PCR).

Axilla↗
PubMedDate not supplied

The combined use of radionuclide angiography and Doppler-sonography in the screening of carotid lesions.

The aim of our research is to check if the combined use of radionuclide angiography and Doppler-sonography leads to correct screening of carotid lesions in the neck, independently from the indexes of reliability of the individual examinations. 125 cerebrovascular patients (for a total of 250 carotid studies) were investigated with radionuclide angiography and Doppler-sonography. 100 of these carotids were also angiographically investigated. On the basis combined angioscintigraphic and Doppler results, these patients have been classified in four groups. When both non-invasive examinations result negative, the angiography shows pathological arteries only in 22% of cases. When only radionuclide angiography is positive, the angiography shows pathological findings in 63% of cases: when only Doppler is positive, the angiography confirmation occurs in 72% of cases. Finally, when both non-invasive tests results positive, there is always arterial pathology in the angiography.

Adult↗