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Biomedical subjects

R Elli

Publications and source records attributed to R Elli.

At least 37 records · Page 2Linked to original sources

The pR UV+ plasmid, transfected into mammalian cells, enhances their UV survival.

It has been recently reported that the pR plasmid enhances the UV survival in E.coli c600. In order to test whether this function may be expressed also in mammalian cells, LTA (tk- aprt-) mouse cells were cotransformed with pR plasmid DNA and ptk1 plasmid as selectable marker. Tk+ transformants were analyzed for their UV survival and for the presence of pR DNA sequences by blot-hybridization. The results show a correlation between the enhanced UV survival and presence of pR DNA sequences in cotransformed LTA mouse cells.

Adenine Phosphoribosyltransferase↗

Cytogenetic investigations on Werner's syndrome, Acrogeria and Keratosis Palmo-Plantaris.

The frequencies of sister chromatid exchanges and of aspecific chromosome aberrations have been investigated in the lymphocytes from a Werner patient, from an Acrogeria patient and from three members of a family with Keratosis Palmo-Plantaris. These investigations point out that: 1) the SCE frequency is significatively enhanced in Werner as in KPP lymphocytes, 2) the frequency of aspecific chromosome aberrations is increased only in Werner lymphocytes, without evidence of variegated translocation mosaicism. The findings confirm that SCE and chromosome aberrations do not necessarily result from the same genetic damage and that SCE may represent the cytological evidence of unexcised non fatal DNA lesions, which occasionally may be responsible for carcinogenesis.

Chromosome Aberrations↗

Identification of a protein coded by pR plasmid and involved in SOS repair in E. coli.

The TP120 plasmid is known to determine enhanced UV survival in E. coli wild type an uvrB and PolA mutants but not in RecA mutant. In order to analyze the function involved in the SOS repair, we have constructed a new plasmid named pR derived by cleavage of TP120 with Hind III endonuclease. This new plasmid maintains the Ap and UV resistance. The insertion of Tn5 transposon in the plasmid allows to select several pR::Tn5 plasmids whose UV resistance was inactivated by the transposition. The comparison of the protein synthesis in the minicells of the pR and pR::Tn5 shows that the pR codes for a 22.000 M.W. dalton protein which is absent in protein pattern of pR::Tn5.

Bacterial Proteins↗

Differences in the levels of UV repair and in clinical symptoms in two sibs affected by xeroderma pigmentosum.

UV-repair activity was studied in two sibs affected by XP showing different clinical symptoms. Complementation studies indicated that both patients fit into complementation group A. The levels of UV-induced 3H-thymidine incorporation, in fibroblasts and in lymphocytes, are different in the two patients: residual level of repair DNA synthesis in the sister is higher than in the brother. In one of the cell samples analyzed UDS analysis showed that in the sister a low proportion of cells with normal repair synthesis is present.

Adolescent↗

Effects of serotonin antagonists in sexually impotent men.

Thirty-one men affected with sexual impotence were studied. Since sexual function in the male seems to be controlled by both dopaminergic stimulatory and serotoninergic inhibitory mechanisms, the patients were treated with serotonin antagonists. In basal conditions mean serum LH, FSH, PRL and testosterone did not significantly differ from those found in normal subjects; no significant variations, except for PRL reduction, were observed after treatment. Both methysergide, in association with bromocriptine or mesterolone, and metergoline, either alone or in association with mesterolone, were ineffective in significantly improving sexual activity.

Adult↗

Study of the effects of bromocriptine on sexual impotence.

Serum testosterone, prolactin, LH, FSH and plasma 17 beta-oestradiol levels were determined in forty-seven male patients with sexual impotence. Low testosterone values and slightly elevated prolactin levels were observed in 19% and in 17% of cases, respectively. Since sexual function in the male seems to be controlled by both dopaminergic stimulatory and serotoninergic inhibitory mechanisms, bromocriptine was given orally to seventeen patients. As the preliminary results appeared encouraging, a double blind study was undertaken in the other thirty patients. No appreciable difference in hormonal pattern was noticed between bromocriptine and placebo treatment. As far as sexual function was concerned, good results were obtained in 52% of cases treated with bromocriptine and in 44% of patients given placebo.

Adult↗

Cleavage of damaged DNA by an enzymatic activity from human fibroblasts.

An endonuclease activity isolated from normal, Xeroderma Pigmentosum and De Sanctis-Cacchione fibroblasts by DNA-cellulose chromatography has been evaluated by means of sedimentation analysis both in alkaline and neutral sucrose gradients. The partially purified enzyme is active at pH 7.5 in presence of Mg++ and cleaves UV-irradiated and alkylated DNA. Under identical experimental conditions, the enzyme is not active on untreated, depurinated and heat-denaturated DNA. The specificity on pyrimidine dimers has been further investigated to understand the mechanism of action of the enzyme.

Alkylation↗

Hypothalamic-pituitary-testicular function in men with PRL-secreting tumors.

We studied the hypothalamic-pituitary-gonadal system in 33 men with PRL-secreting tumors to determine at which level(s) high PRL levels interfere with testicular function. In basal conditions serum PRL levels ranged between 24-4500 ng/ml, serum LH and FSH concentrations were lower than normal in 61% and 39% of patients; low testosterone (T) levels and sexual impotence appeared more common (85% and 88%) than that we expected on the basis of gonadotropin deficiency. Mean T increase after hCG in 14 patients with prolactinomas was significantly less than in normals (3.3 +/- 0.7) ng/Ml vs 7.3 +/- 0.5 ng/ml; p less than 0.025); a significantly higher T response to hCG was obtained in 5 cases retested after PRL levels had been reduced by therapy. GnRH test induced a normal LH rise in 45% of patients, Mean serum LH increase after clomiphene administration did not differ from that in normals, though 4 out of 10 patients showed an impared response. Metoclopramide injection did not cause a rise of LH in 11 patients so tested. These data, while not excluding a central influence of PRL on LHRH, suggest that in men the antigonadotropic effects of PRL are mainly exerted at the gonadal levels.

Adenoma↗