In this article, we present the response of Medicago truncatula Gaert. cv. Jemalong plants expressing constitutively the Dsp22 gene from Craterostigma plantagineum to water stress and rehydration. The Dsp22 gene encodes an ELIP-like protein thought to protect the chloroplast against photooxidative damage during the dehydration and rehydration. The Dsp22 transgenic homozygous M. truncatula plants showed higher amount of chlorophyll (Chl), lower Chl a/Chl b ratio and higher actual efficiency of energy conversion in photosystem 2 (Φ PSII ) after rehydration when compared to the wild type. The combined data from the Chl a fluorescence analysis, pigment quantification, and biomass accumulation showed that transgenic M. truncatula plants are able to recover from water deprivation better than wild type plants.

We analyzed DNA lesions produced by H2O2 under low iron conditions, the cross adaptive response and the synergistic lethal effect produced by iron chelator-o-phenanthroline, using different Escherichia coli mutants deficient in DNA repair mechanisms. At normal iron levels the lesions produced by H2O2 are repaired mainly by the exonuclease III protein. Under low iron conditions we observed that the Fpg and UvrA proteins as well as SOS and OxyR systems participate in the repair of these lesions. The lethal effect of H2O2 is strengthened by o-phenanthroline if both compounds are added simultaneously to the culture medium. This phenomenon was observed in the wild type cells and in the xthA mutant (hypersensitive to H2O2). E. coli cells treated with low concentrations of H2O2 (micromolar) acquire resistance to different DNA damaging agents. Our results indicate also that pretreatment with high (millimolar) H2O2 concentrations protects cells against killing, by UV and this phenomenon is independent of the SOS system, but dependent on RecA and UvrA proteins. H2O2 induces protection against lethal and mutagenic effects of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). H2O2 also protects the cells against killing by cumene hydroperoxide, possibly with the participation of Ahp protein.

Objetivo: Essa revisão sistemática da literatura tem como objetivo trazer os fatores de risco para suicídio em adolescentes e jovens adultos mais relevantes na literatura. Métodos: Foi realizado uma busca de alta sensibilidade nas principais bases de dados: PubMed, Web of Science, Cinahl, EMBASE; Cochrane; BVS. Os critérios de inclusão foram: Estudos observacionais ou Ensaios Clínicos Randomizados que relacionam a ideação suicida e o suicídio de jovens e adolescentes com potenciais fatores de risco. Resultados: Os estudos apontaram diversos fatores de risco para ideação e suicídio na população estudada, dentre eles os mais citados foram rejeição familiar, não conformidade de gênero na infância, intimidação na escola, vtimização, não conformidade por ser transgênero e "depressão, ansiedade, outros transtornos mentais". Conclusão: A população de jovens e adolescentes transgêneros possuem maiores índices de suicídio, fato que está diretamente atrelado a maior quantidade de fatores de risco, associados a alta discriminação e violência e a própria fase da vida