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| Morais Jr.,M.A.; Vlcková,V.; Fridrichová,I.; Slaninová,M.; Brozmanová,J.; Henriques,J.A.P.. |
| Molecular and functional homology between yeast proteins pRad51 and pRad52 and Escherichia coli pRecA involved in recombinational DNA repair led us to investigate possible effects of recA gene expression on DNA repair in rad51 and rad52 mutants of Saccharomyces cerevisiae. The mutant cells were subjected to one of the following treatments: preincubation with 8-methoxypsoralen and subsequent irradiation with 360-nm ultraviolet (UVA) (8-MOP + UVA), irradiation with 254-nm UV light or treatment with methyl methane sulfonate (MMS). While recA expression did not repair lethal DNA lesions in mutant rad51, it was able to partially restore resistance to 8-MOP + UVA and MMS in rad52. Expression of recA could not complement the sensitivity of rad51rad52 double... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1998 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47571998000100002 |
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| Picada,J.N.; Roesler,R.; Henriques,J.A.P.. |
| Apomorphine is a dopamine receptor agonist proposed to be a neuroprotective agent in the treatment of patients with Parkinson's disease. Both in vivo and in vitro studies have shown that apomorphine displays both antioxidant and pro-oxidant actions, and might have either neuroprotective or neurotoxic effects on the central nervous system. Some of the neurotoxic effects of apomorphine are mediated by its oxidation derivatives. In the present review, we discuss recent studies from our laboratory in which the molecular, cellular and neurobehavioral effects of apomorphine and its oxidized derivative, 8-oxo-apomorphine-semiquinone (8-OASQ), were evaluated in different experimental models, i.e., in vitro genotoxicity in Salmonella/microsome assay and WP2... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Apomorphine; 8-Oxo-apomorphine- semiquinone; Dopamine; Genotoxicity; Neurotoxicity. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2005000400001 |
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| Manfredini,V.; Roehrs,R.; Peralba,M.C.R.; Henriques,J.A.P.; Saffi,J.; Ramos,A.L.L.P.; Benfato,M.S.. |
| Saccharomyces cerevisiae mutants deficient in superoxide dismutase genes (sod1delta, sod2delta and the double mutant) were subjected to H2O2 stress in the stationary phase. The highest sensitivity was observed in the sod2delta mutant, while the sod1deltasod2delta double mutant was not sensitive. Sod mutants had lower catalase activity (44%) than wild-type cells, independent of H2O2 stress. Untreated cells of sod1deltasod2delta double mutants showed increased glutathione peroxidase activity (126%), while sod1delta had lower activity (77%) than the wild type. Glutathione levels in sod1delta were increased (200-260%) after exposure to various H2O2 concentrations. In addition, the highest malondialdehyde levels could be observed without H2O2 treatment in... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Catalase; Superoxide dismutase; Glutathione; Hydrogen peroxide; Saccharomyces cerevisiae; Reactive oxygen species. |
| Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2004000200001 |
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| Tondo,E.C.; Andretta,C.W.S.; Souza,C.F.V.; Monteiro,A.L.; Henriques,J.A.P.; Ayub,M.A.Z.. |
| An aerobic Gram positive spore-forming bacterium was isolated from cellulose pulp mill effluent. This microorganism, identified as Bacillus sp. and named IS13, was able to rapidly degrade the organic chlorinated compound 4,5,6-trichloroguaiacol (4,5,6-TCG) from a culture containing 50 mg/l, which corresponds to about 3x104 times the concentration found in the original effluent. The biodegradation of this compound, usually found in cellulose pulp mill effluents, was evaluated by spectrophotometry and gas chromatography analysis. During 4,5,6-TCG decreasing, the lack of by-products had shown by such analysis lead to verify the possibility of either adsorption or absorption of 4,5,6-TCG by the cells, instead of real biodegradation. There were no traces of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Biodegradation 4; 5; 6-trichloroguaiacol aerobic bacteria DNA. |
| Ano: 1998 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37141998000400006 |
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| Rosa,R.M.; Roesler,R.; Braga,A.L.; Saffi,J.; Henriques,J.A.P.. |
| The pharmacology of synthetic organoselenium compounds indicates that they can be used as antioxidants, enzyme inhibitors, neuroprotectors, anti-tumor and anti-infectious agents, and immunomodulators. In this review, we focus on the effects of diphenyl diselenide (DPDS) in various biological model organisms. DPDS possesses antioxidant activity, confirmed in several in vitro and in vivo systems, and thus has a protective effect against hepatic, renal and gastric injuries, in addition to its neuroprotective activity. The activity of the compound on the central nervous system has been studied since DPDS has lipophilic characteristics, increasing adenylyl cyclase activity and inhibiting glutamate and MK-801 binding to rat synaptic membranes. Systemic... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Diphenyl diselenide; Organoselenium; Antioxidants; Neuroprotection; Saccharomyces cerevisiae; Mutagenesis. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2007001000001 |
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| Bonatto,D.; Revers,L.F.; Brendel,M.; Henriques,J.A.P.. |
| DNA double-strand breaks (DSBs) represent a major threat to the genomic stability of eukaryotic cells. DNA repair mechanisms such as non-homologous end joining (NHEJ) are responsible for the maintenance of eukaryotic genomes. Dysfunction of one or more of the many protein complexes that function in NHEJ can lead to sensitivity to DNA damaging agents, apoptosis, genomic instability, and severe combined immunodeficiency. One protein, Pso2p, was shown to participate in the repair of DSBs induced by DNA inter-strand cross-linking (ICL) agents such as cisplatin, nitrogen mustard or photo-activated bi-functional psoralens. The molecular function of Pso2p in DNA repair is unknown, but yeast and mammalian cell line mutants for PSO2 show the same cellular responses... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Non-homologous end joining; Double-strand breaks; V(D)J; PSO2; Artemis; Saccharomyces cerevisiae. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2005000300002 |
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