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C Taddei

Publications and source records attributed to C Taddei.

14 recordsLinked to original sources
PubMed1991

Comparative studies on the anorectic activity of d-fenfluramine in mice, rats, and guinea pigs.

The present study compares the anorectic activity of d-fenfluramine and its metabolite d-norfenfluramine in three animal species. d-Fenfluramine and d-norfenfluramine show anorectic activity at increasing doses (ED50) in rats, guinea pigs, and mice, d-norfenfluramine being more active than d-fenfluramine in all three species. Equiactive anorectic activities are reached with different brain levels of d-fenfluramine and d-norfenfluramine, guinea pigs being the most sensitive species, followed by rats then mice. The metabolite most probably plays a major role in the anorectic effect of d-fenfluramine in guinea pigs, contributes to the anorectic activity in rats, but adds little to the action of the parent drug in mice. The different sensitivity to d-fenfluramine and d-norfenfluramine in these three species does not appear to be explained by a number of biochemical parameters, including serotonin uptake or release, receptor subtypes, or 3H-d-fenfluramine binding and uptake.

Animals↗
PubMed1991

Effects of complete denture wearing on temporomandibular joints: a histomorphometric study.

At autopsy, 54 human temporomandibular joints were distributed in three groups. The first group was made up of 14 joints of dentate subjects (mean age = 51 years). The second group was composed of 12 temporomandibular joints of totally edentulous patients who had lost their teeth for at least 10 years (mean age = 82 years). The third group was composed of 28 joints of edentulous patients who had been wearing complete dentures for at least 20 years (mean age = 66 years). Sagittal serial decalcified sections were studied by light microscopy and was submitted to histomorphometry. Group 1 was characterized by a deep mandibular fossa with well-marked cortical layers of the temporal bones and the condyles. The fibrocartilages were multilayered and the articular disks had biconcave outlines. In group 2 a flattening of the mandibular fossa was observed, with a thinning of the cortical and spongy bones. The fibrocartilages were thin and not multilayered. In group 3, the structure of joints was similar to that of group 1. The mean values of the surfaces, thicknesses, and lengths of the measured parameters were systematically highest in group 1, whereas these mean values in group 3 were similar to or had a tendency to be close to the means of group 1. In contrast, the mean values of group 2 were always the lowest. It can be concluded that complete dentures had a favorable protective effect on temporomandibular joint structures.

Adult↗
PubMed1990

Structural modifications of the nuclear components during lizard oogenesis in relation to the differentiation of the follicular epithelium.

This paper deals with an electron microscope study of nucleolar ultrastructural modifications that occur in the oocytes of the lizard Podarcis sicula during ovarian follicle differentiation. In small diplotene oocytes around which a monolayered follicular epithelium forms, the nucleolus appears as a fibrillo-granular structure. Afterwards, simultaneously with the beginning of pyriform cell differentiation inside the granulosa, the nucleolus progressively condenses and breaks into fragments, forming dense spherical bodies. In larger follicles, with well differentiated pyriform cells, a typical nucleolus is no longer detectable in the oocyte nucleus. These ultrastructural modifications suggest a possible impairment of the oocyte nucleolus in ribosome organization. A possible involvement of pyriform cells in supplying ribosomes to the growing oocyte is discussed.

Animals↗
PubMed1990

In-vivo radiolabelled oxiracetam binding to rat brain.

The in-vivo binding of [3H]oxiracetam has been studied in brain areas of rats examined 30 min after i.c.v. injection. Soluble radioactivity accounted for more than 90% of total radioactivity in all the structures considered and was not affected by co-injection with a 1000-fold excess of unlabelled oxiracetam. Both total and bound radioactivity showed a marked regional distribution, with highest concentrations in the septum, followed by the hippocampus; the cerebral cortex, striatum and cerebellum had the lower concentrations of radioactivity. Computer-assisted quantitative autoradiography with [14C]oxiracetam confirms these findings. Analysis of [3H]oxiracetam bound to membranes indicated that, after co-injection with a 1000-fold excess of unlabelled oxiracetam, there was a significant reduction of binding only in the septum, hippocampus and cerebral cortex. These results suggest that in those cerebral structures oxiracetam binds to saturable sites.

Animals↗
PubMed1978

Intercellular bridges between follicle cells and oocyte during the differentiation of follicular epithelium in Lacerta sicula Raf.

Intercellular bridges first appear during lizard oogenesis when follicles are rather small (150 microgram in diameter); at this stage they form connecting links between the oocyte and follicle cells, which have not yet differentiated into pyriform cells. Later on, when the follicles have become larger (1 mm) and the follicular epithelium appears constituted by 3 types of cells (small, intermediate and pyriform cells) they form connecting links between the oocyte and both intermediate and pyriform cells. The establishment of intercellular bridges between pyriform cells and the oocyte precedes the complete differentiation of the former, which excludes the possibility that the fusion between pyriform cells and oocyte occurs only after these cells are completely differentiated. In still larger follicles (up to 2 mm in diameter), during the degeneration of the pyriform cells, the occurrence, inside the bridges, of mitochondria and other cytoplasmic material suggests that these cells at the end of their function transfer their contents into the oocyte.

Animals↗
PubMed1977

Progesterone-induced DNA polymerase activity in full-grown oocytes of Xenopus laevis (1).

DNA polymerase activity increases in full-grown oocytes of Xenopus laevis during in vitro progesterone-induced maturation. This increase is inhibited by cycloheximide. The presence of the oocyte's nucleus (germinal vesicle) seems essential for the induction of this increase: in previously enucleated oocytes, the level of DNA polymerase activity does not change during progesterone treatment. Furthermore, a new form of DNA polymerase is detectable by DEAE chromatography in in vitro matured oocytes.

Animals↗
PubMed1976

Intercellular bridges in lizard oogenesis.

Study of the germinal epithelium in the adult lizard shows that the germ cells constitute clusters of synchronized cells interconnected by intercellular bridges. Such bridges interconnect oogonia as well as early meiotic prophase oocytes (zygo-pachitene). Besides true intercellular bridges in oocytes, there are plasma membrane interruptions forming large zones that ensure cytoplasmic continuity between adjacent cells. In early diplotene, germ cells are isolated. Later, during auxocytosis, when the polymorphic follicular epithelium around the oocyte starts differentiating, intercellular bridges appear between the follicle cells and oocyte. No relationship is observed between the intercellular bridges found in the germinal epithelium and those found between the follicle cells and oocyte.

Animals↗
PubMedDate not supplied

[Hemolytic-uremic syndrome: association with vero cytotoxin-producing Escherichia coli. An epidemiological and microbiological study on possible animal reservoirs].

Vero cytotoxin-producing strains of Escherichia coli (VTEC) appear to be in man associated with a range of clinical symptoms from mild non bloody diarrhoea to haemorrhagic colitis and severe haemolytic uraemic syndrome (HUS). We present two patients affected by HUS who were investigated to determine evidence of infection by VTEC. In one of the patient free fecal cytotoxin active on Vero cells was detected as well as seroconversion of VT-neutralizing antibody titre. Both children were living in the same county town, but all parents denied any animal contact. The source of infection was not identified but one child had eaten ground beef during the period immediately prior to the onset of symptoms. Epidemiological informations are presented and the results of a study on the possible animal reservoir are illustrated. Fecal cultures were performed on 38 stools specimen obtained from non diarrheal beef cattle and pork. One VT- producing Escherichia coli strain was isolated in pork faeces (20 stools sample) whereas two VTEC were found in cattle faeces (18 stool sample).

Animals↗