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Biomedical subjects

L Fiore

Publications and source records attributed to L Fiore.

At least 37 records · Page 2Linked to original sources
PubMed1987

Paralytic poliomyelitis in Italy (1981-85).

Fifteen cases of presumptive poliomyelitis occurring in Italy between 1981-85 were studied in order to differentiate between paralysis caused by poliovirus and that of different etiology. Out of seven confirmed cases three were "temporally associated with vaccination". Three aspects are discussed: the need for a careful differential diagnosis of paralytic cases; the over concern about the problem of vaccine-associated cases: the risk connected with re-importation of wild poliovirus strains.

Child, Preschool↗
PubMed1987

Antigenic and biochemical characterization of poliovirus type 2 isolated from two cases of paralytic disease.

Three isolates of poliovirus type 2 were obtained from rectal and pharyngeal swabs of two patients with paralytic poliomyelitis from Southern Italy (1981/1983). Neither one of the patients had received oral poliovirus vaccine, although a systematic vaccination campaign is conducted in the area. Neutralization tests with strain-specific antisera and analysis of the structural proteins by SDS-PAGE indicated that the three isolates were typical Sabin-like poliovirus type 2. Moreover, neutralization assays by means of a panel of well-characterized monoclonal antibodies indicated that the three isolates carried an antigenic mosaic where both wild-type and Sabin-specific epitopes were represented. The T1 fingerprints of the RNA of the three isolates diverged slightly from the standard Sabin reference map. A comparison of the oligonucleotide fingerprints of the viruses isolated from the pharynx and the feces of one patient indicated that mutations appeared as early as during replication in the intestinal tract.

Antibodies, Monoclonal↗
PubMed1987

Effect of dihydroergocryptine and dihydroergocristine on cyclic AMP accumulation and prolactin release in vitro: evidence for a dopaminomimetic action.

Dihydroergocryptine and dihydroergocristine, two C-9, 10-hydrogenated ergot alkaloids, inhibited in a concentration-dependent manner prolactin release and cyclic AMP accumulation in cultured anterior pituitary cells. The inhibitory effect of dihydroergocryptine was more potent and started at lower concentrations than that of dihydroergocristine. Haloperidol and pimozide, two dopamine receptor antagonists, completely abolished the inhibitory activity of the ergot alkaloids. The involvement of the adenylate cyclase-cyclic AMP system in the inhibitory action of the two compounds was demonstrated by the antagonism by pertussis toxin of the reduction of both prolactin release and cyclic AMP accumulation produced by dihydroergocryptine and dihydroergocristine.

Animals↗
PubMed1986

Cross-correlation analysis of intracellularly recorded synaptic activities: an evaluation of the method through computer simulation.

Cross-correlation of 'spontaneous' synaptic activities intracellularly recorded from pairs of neurons may be used to detect shared synaptic input, which could remain hidden in the raw data by the non-synchronized postsynaptic potentials (PSPs); besides, if a normalized cross-correlation function is adopted, the fraction of synchronized activity may be quantitatively estimated. To evaluate power and limits of this method, computer-simulated synaptic activities of pairs of neurons, in which a given percentage of PSPs were simultaneous, were subjected to this type of analysis. It was shown that percentages of shared activities as low as 4% and in some cases 2% could be revealed, with a conspicuity which was influenced by the types of associated PSPs.

Action Potentials↗
PubMed1986

[First experiences with trans-rectal echotomography in perianal abscess pathology].

Trans-rectal ultrasound with a 5 MHz probe was used to examine 16 patients who had perianal fistulas and 5 of them underwent one or more surgical explorations. In 11 cases, all surgically checked, sonography was able to demonstrate a pararectal abscess and accurately image the site, size, extension and--in some cases--the fistula itself. It can be advised that, using high frequency probes (7 or 10 MHz), transrectal ultrasound could provide even more exact diagnostic information in anorectal pathology.

Abscess↗
PubMed1985

Input-output relationships of identified buccal neurones involved in feeding control in Aplysia.

A group of about 28 neurones located in the lateral portion of the caudal face of Aplysia buccal ganglion and projecting into the cerebro-buccal connective were identified by retrograde cobalt staining, and designated as L neurones. It was found that the L neurones did not establish synaptic relations with the known buccal neurones, which are mainly involved in the production of the consummatory phase of feeding, nor with several cerebral neurones tested, including the well-known serotonin giant cell. Neither did they show responses to stimulation of the nerves directed to the buccal mass. On the other hand, the L neurones showed depolarizing responses, with the possible addition of a weak, slower hyperpolarizing phase, to stimulation of the ipsi- and contralateral oesophageal nerves, which innervate the portion of the gut posterior to the buccal mass. These findings, together with several properties of the oesophageal nerve input, suggest that one function of the L cells is to transmit information about gut regions posterior to the buccal mass towards the cerebral ganglia, and that they may mediate the inhibitory influence which in Aplysia is known to be exerted upon feeding by the presence of bulk in the anterior gut. The L neurones showed synaptic responses - consisting mainly or exclusively of depolarizations - to stimulation of the cerebro-buccal connectives. Besides this, large, tonic EPSPs, which often occurred in the 'spontaneous' activity of the L neurones, were found to be generated by spikes that travelled in the cerebro-buccal connective towards the buccal ganglion.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1979

Synaptic connections and functional organization in Aplysia buccal ganglia.

The buccal ganglion of Aplysia contains three morpho-functional groups (A, B, and C) of large cells and two groups (s1 and s2) of small cells. The A cells evoke monoxynaptic IPSPs in the B cells. We found that s1 cells can evoke large EPSPs in the A cells, IEPSPs in the B cells, and EIIPSPs in the C cells; several s1 cells are able to evoke all three types of responses. Many s2 cells can evoke these same responses, but only in the A and B cells. Furthermore, the s cells can evoke depolarizing PSPs in other s cells; this relation is often reciprocal. All these responses may also be contralateral. Their monosynaptic nature is shown by the consistent 1:1 relationship with the presynaptic spike, and also by the effects of intracellular tetraethylammonium and of high Mg2+ concentration in the bathing medium. d-tubocurarine reversibly suppresses the I phase of the IEPSP evoked by the s cells in the B cells. All the responses evoked by the s cells undergo depression with repetition. The network formed by all these relations is outlined, and a double relationship proposed between s cells and B cells. By electrophysiological tracing of axonal pathways it is shown that the A cells send axons into the 3rd buccal nerve, the B cells into the 2nd and/or 3rd buccal nerve and in two cases into the radular nerve, and the C cells into the gastro-oesophageal nerve. Spontaneous synaptic activity of the buccal neurons appears to be formed mostly by the described PSPs. Spontaneous firing inside the isolated ganglion corresponds well to the alternate pattern of muscular contractions of the buccal mass.

Animals↗
PubMed1979

Independent inhibition of prolactin secretion by dopamine and gamma-aminobutyric acid in vitro.

gamma-Aminobutyric acid (GABA) inhibits PRL release from incubated hemipituitaries in a dose-dependent manner. The maximum inhibition obtained with GABA is less than that obtained with dopamine. Its affinity is 100 times lower. The effect is blocked by picrotoxin but not by a dopamine inhibitor; alpha-flupentixol but not picrotoxin antagonizes dopamine inhibition. This indicates that dopamine and GABA inhibit PRL release through independent receptors. The hypothalamic extract contains sufficient GABA to inhibit PRL release in our in vitro conditions. Picrotoxin, however, does not significantly inhibit the nondopaminergic PRL-inhibiting activity of mediobasal hypothalamic extracts. Another nondopaminergic PRL-inhibiting factor, therefore, seems to be present in the hypothalamus.

Animals↗