The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material. http://http://dspace.unitus.it:80 2013-05-19T17:15:17Z 2013-05-19T17:15:17Z Mosesso, Pasquale Fonti, Enrica Bassi, Loredana Lorenti Garcia, Claudia Palitti, Fabrizio http://hdl.handle.net/2067/1719 2011-06-30T12:16:30Z 1998-12-31T23:00:00Z

Title: The involvement of chromatin condensation in campthotecin-induced chromosome breaks in G0 human lymphocytes Authors: Mosesso, Pasquale; Fonti, Enrica; Bassi, Loredana; Lorenti Garcia, Claudia; Palitti, Fabrizio Abstract: In the present study we evaluated campthotecin (CPT)-induced chromosomal damage in human lymphocytes in the G0 phase of the cell cycle as revealed by the premature chromosome condensation technique. The results obtained here indicate that CPT was able to induce chromosome fragments in the G0 phase of the cell cycle of human lymphocytes as detected in prematurely condensed chromosomes. This result appears to be rather surprising, since the DNA lesions produced by CPT (e.g. 'protein concealed' DNA single-strand breaks) should not produce any damage in G0. A possible explanation for this result could come from much evidence to suggest that chromatin condensation processes are significantly involved in the conversion of DNA lesions into chromosome breaks in prematurely condensed chromosomes. The unexpected clastogenic behaviour of CPT can be explained taking into account the chromosome condensation induced by mitosis promoting factors when human lymphocytes are fused in G0, thus converting the 'protein concealed' DNA single-strand breaks induced by CPT into chromosome breaks. The same perspective should be taken into consideration for breaks induced by CPT under normal physiological conditions in the G2 phase of the cell cycle. Description: L'articolo é disponibile sul sito dell'editore: http://www.oxfordjournals.org

1998-12-31T23:00:00Z Mosesso, Pasquale Penna, Sabrina Pepe, Gaetano Lorenti Garcia, Claudia Palitti, Fabrizio http://hdl.handle.net/2067/1349 2011-08-08T23:05:25Z 2003-12-31T23:00:00Z

Title: Potassium Bromate but not X-ray cause unexpectedly elevated levels of DNA breakage similar to those induced by ultraviolet light in Cockayne syndrome (CS-B) fibroblast Authors: Mosesso, Pasquale; Penna, Sabrina; Pepe, Gaetano; Lorenti Garcia, Claudia; Palitti, Fabrizio Abstract: It has been previously reported that the elevated accumulation of repair incision intermediates in cells from patients with combined characteristics of xeroderma pigmentosum complementation group D (XP-D) and Cockayne syndrome (CS) XP-D/CS fibroblasts following UV irradiation is caused by an "uncontrolled" incision of undamaged genomic DNA induced by UV-DNA-lesions which apparently are not removed. This could be an explanation for the extreme sensitivity of these cells to UV light. In the present study, we confirm the immediate DNA breakage following UV irradiation also for CS group B (CS-B) fibroblasts by DNA migration in the "comet assay" and extend these findings to other lesions such as 8-oxodeoxyguanosine (8-oxodG), selectively induced by KBrO3 treatment. In contrast, X-ray exposure does not induce differential DNA breakage. This indicates that additional lesions other than the UV-induced photoproducts (cyclobutane pyrimidine dimers, CPD, and 6-pyrimidine-4-pyrimidone products, 6-4 PP), such as 8-oxodG, specifically induced by KBrO3, are likely to trigger "uncontrolled" DNA breakage in the undamaged genomic DNA in the CS-B fibroblasts, thus accounting for some of the clinical features of these patients Description: L'articolo é disponibile sul sito dell'editore: http://www.karger.com

2003-12-31T23:00:00Z Lorenti Garcia, Claudia Filippi, Silvia Mosesso, Pasquale Menotti Calvani, R. Nicolai, Raffaella Mosconi, Luigi Palitti, Fabrizio http://hdl.handle.net/2067/1345 2011-06-30T14:51:22Z 2005-12-31T23:00:00Z

Title: The protective effect of L-Carnitine in peripheral blood human lymphocytes exposed to oxidative agents Authors: Lorenti Garcia, Claudia; Filippi, Silvia; Mosesso, Pasquale; Menotti Calvani, R.; Nicolai, Raffaella; Mosconi, Luigi; Palitti, Fabrizio Abstract: Literature data indicate l-carnitine (LC), a trans-mitochondrial carrier of acetyl and long chain groups, as an agent possessing protective effects against oxidative stress in mammalian cells. However, the major factor involved in the protective mechanism is not known. The protection activity exerted by this agent against reactive oxygen species induced by hydrogen peroxide (H2O2) and t-butylhydroperoxide (t-butyl-OOH) treatment in isolated human peripheral blood lymphocytes (PBLs) has been studied. Human lymphocytes cells were isolated and pre-incubated with 5 mM lc before H2O2 (100 µM) and t-butyl-OOH (400 µM) treatment. The protective effect of lc on treated PBLs was measured by single cell gel electrophoresis and the analysis of chromosomal aberrations. Results show that lc treated cells exhibited a significant decrease in the number of oxidative induced single-strand breaks and chromosomal aberrations. Description: L'articolo é disponibile sul sito dell'editore: http://www.oxfordjournals.org

2005-12-31T23:00:00Z