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Biomedical subjects

C Nazzaro

Publications and source records attributed to C Nazzaro.

9 recordsLinked to original sources

Serotonin modulation of cell excitability and of [3H]GABA and [3H]D-aspartate efflux in primary cultures of rat cortical neurons.

The effects of 5-hydroxytryptamine (5-HT) on neuronal excitability, evaluated as depolarization-induced firing rate, and on amino acid release, measured as electrically-evoked [(3)H]GABA and [(3)H]d-aspartate efflux, were investigated in rat primary cortical neuronal cultures. 5-HT displayed a concentration-dependent, bimodal effect on neuronal excitability: at 3-10microM it increased excitability through 5-HT(2A) receptors, and was blocked by the selective 5-HT(2A) antagonist MDL 100907, whereas at 30-100microM it reduced excitability through 5-HT(1A) receptors, and was, in turn, blocked by the selective 5-HT(1A) antagonist WAY 100135. The electrically-evoked [(3)H]GABA efflux was concentration-dependently inhibited by 5-HT (pEC(50)=4.74) and such inhibition was prevented by WAY 100135, but not by GR 55562, a selective 5-HT(1D/B) receptor antagonist. Conversely, 5-HT concentration-dependently increased stimulus-evoked [(3)H]d-aspartate efflux (pEC(50)=4.71). The increase was facilitated by methiothepin and was reversed into inhibition by ICS 205930, a selective 5-HT(3) receptor antagonist. In the presence of ICS 205930, the inhibition induced by 5-HT was prevented by the selective 5-HT(1D/B) receptor antagonist GR 55562, but not by WAY 100135. These findings suggest that 5-HT inhibits GABA release through 5-HT(1A) receptors and exerts a dual modulation on glutamate release, mostly facilitatory (through 5-HT(3) receptors) but also inhibitory (through 5-HT(1D/B) receptors), leading to a prevalently positive modulation of the excitatory signal by amino acid neurotransmitter containing neurons.

Animals↗

Salmonella typhimurium porin internalization by leukocytes.

The location of Salmonella typhimurium porins has been found in human monocytes and lymphocytes by means of high resolution autoradiography. The results indicate that traces of porins are frequently visible on ultrathin sections of treated human lymphomonocytes and that they are located especially in the nuclear areas.

Adult↗

Effects of benzodiazepines on immunodeficiency and resistance in mice.

Our results indicate that benzodiazepine (Bz) treatment time, greater than 2-3 months, induce a decrease of both specific and nonspecific responses. Mice treated for different times with diazepam or chlordemethyldiazepam showed decreased survival to experimental Salmonella typhimurium infections after three months of treatment. Adherence, expressed as the polymorphonuclear cells (PMN) capacity to attach to nylon wool, was impaired after 7 days of treatment. Longer treatments further increase this impairment. PMN from mice treated with Bz for 90 days also demonstrate on impaired chemotaxis and phagocytosis for Saccharomyces cerevisiae. Monocytes from mice treated for 7 days secreted more IL-1 alpha then controls; the antibody titer in mice given to prolonged treatment progressively diminished compared to controls. Con A or LPS stimulated lymphocytes showed an increase of H3-thymidine incorporation from mice treated for a short time and conversely a decreased incorporation when taken from mice that underwent longer treatments. Benzodiazepines were therefore found to affect PMN chemotaxis and phagocitosis, general immunity and survival of mice to infections.

Animals↗

Modification of actin in peritoneal macrophages after diazepam treatment.

We have investigated the effect of therapeutic doses of diazepam (7 micrograms/mouse) on the association of actin with the macrophage cytoskeleton using cytochemical and morphological methods. Results obtained indicated that diazepam was able to modulate the content of actin in macrophages; such an effect proved to be time-dependent. After fixation and staining for indirect immunofluorescence with actin antibody, peritoneal macrophages from mice treated for short time with diazepam, showed a fluorescent intensity increase compared to control mice. The fluorescent intensity augmented reaching peak value within 14 days of treatment. Afterwards, this value dropped below control value for mice that underwent longer treatments. In the in vitro experiments concentrations of 10(-5) M, diazepam inhibited a well cell spread and a lower amount of actin after 15 min of incubation was also revealed. These results suggest that administration of diazepam in vivo plays a role in both the nonspecific and specific immune response, producing in the macrophages a reorganization process of microfilaments.

Actin Cytoskeleton↗

Morphological changes induced in HEp-2 cells by Salmonella typhimurium porins.

The effects of different doses of Salmonella typhimurium porins were investigated on human laryngeal epithelial (HEp-2) cells by fluorescence and transmission electron microscopy. The changes observed in microfilament organization suggested an involvement of cytoskeleton in the cell response. Furthermore, morphologic phenomena characterized by ultrastructural membrane modifications also involved the nuclear membrane.

Cells, Cultured↗

[Chilaiditi's syndrome: a rare cause of abdominal pain in the differential diagnosis of the abdominal perforation. Case report].

A case of a 92-years-old patient with abdominal pain and constipation is presented. He reported a recent traumatic fracture of the upper limb. Traditional diagnostic work-up for patient with abdominal pain was started up. He was submitted to abdominal film that demonstrated air underneath the diaphragm suggestive for perforation. This hallmark is opposed to clinical condition of patient, so differential diagnosis for rare Chilaiditi's syndrome was considered, because this syndrome is frequent in old patient. Diagnostic work-up was completed with upper abdominal CT that excluded intestinal perforation and confirmed the diagnosis of Chilaiditi's syndrome showing hepatodiaphragmatic interposition of the dilated colon. Therefore it was decided in favour of medical therapy. In the our case, in spite of negative clinical examination, the uncertain radiological hallmark obliged us to exclude diagnosis of abdominal perforative syndrome that needs emergency operation. Although the Chilaiditi's syndrome is rare, it must be considerated in differential diagnosis of perforative abdominal syndrome, when there are doubts about the subdiaphragmatic air in abdominal film.

Abdominal Pain↗