Navegando por Autor "Rocha, Lorrana Cachuite Mendes"
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Item Efeito da contaminação por arsênio sobre a comunidade de bactérias cultiváveis do solo.(2021) Rocha, Lorrana Cachuite Mendes; Garcia, Camila Carrião Machado; Moreira, Leandro Marcio; Garcia, Camila Carrião Machado; Barboza, Natália Rocha; Silva, Silvana de QueirozO Arsênio é um semi-metal amplamente difundido na crosta terrestre associado a outros compostos minerais. Atividades antrópicas, como mineração e agricultura, e naturais como o intemperismo de rochas elevam a quantidade de As no ambiente. Os compostos derivados de As são considerados altamente tóxicos, estando associados ao desenvolvimento de uma série de patologias em resposta à intoxicação aguda e crônica, como doenças de pele e gastrointestinais, e diversos tipos de câncer. Sendo assim, estudar processos que possam nos auxiliar no tratamento de solos e águas contaminadas é de grande importância. Bactérias têm se mostrado microrganismos bastante interessantes para esses processos. Neste trabalho, procuramos avaliar o efeito da contaminação por arsênio sobre a comunidade bacteriana dos solos através de métodos dependentes de cultivo. Inicialmente, bactérias foram isoladas a partir de solo contaminado artificialmente com 55 µg/Kg de Arsenato de Sódio, solo naturalmente contaminado proveniente do quadrilátero ferrífero e solo controle entre 0 e 115 dias após a contaminação. Foram isolados 466 microrganismos e estes selecionados de acordo com suas tolerâncias às doses de 10-15 mM de Arsenato de Sódio e 1-3 mM de Arsenito de Sódio. Os 29 isolados mais tolerantes foram submetidos a crescimento em presença de Manganês (20-70 mM), Ferro (6-15 mM), diferentes valores de pH (4-12) e doses mais elevadas de arsenito (4-15 mM) e arsenato (25-400 mM). Os 10 isolados mais resistentes quanto à tolerância aos metais e principalmente arsenito e arsenato foram novamente selecionados e caracterizados quanto à formação de biofilme, curva de crescimento, tolerância ao peróxido de hidrogênio (10-200 mM) e características morfológicas e de parede celular. Nossos resultados apontam para um conjunto de bactérias com alta resistência a As, prospectadas principalmente do solo tratado com As, e que podem ser utilizadas em atividades de remediação de ambientes contaminados com o semi-metal.Item Hatchery tanks induce intense reduction in microbiota diversity associated with gills and guts of two endemic species of the São Francisco River.(2022) Damasceno, Maria Rosilene Alves; Lemes, Camila Gracyelle de Carvalho; Braga, Lucélia Sandra Silva Barbosa; Tizioto, Polyana Cristine; Montenegro, Horácio; Paduan, Marcela; Pereira, Josielda Gomes; Cordeiro, Isabella Ferreira; Rocha, Lorrana Cachuite Mendes; Silva, Sibele Aryadne da; Sanchez, Angelica Bianchini; Lima, Wanderson Geraldo; Yazbeck, Gabriel de Menezes; Moreira, Leandro Marcio; Garcia, Camila Carrião MachadoThe São Francisco River (SFR), one of the main Brazilian rivers, has suffered cumulative anthropogenic impacts, leading to ever-decreasing fish stocks and environmental, economic, and social consequences. Rhinelepis aspera and Prochilodus argenteus are medium-sized, bottom-feeding, and rheophilic fishes from the SFR that suffer from these actions. Both species are targeted for spawning and restocking operations due to their relevance in artisanal fisheries, commercial activities, and conservation concerns. Using high-throughput sequencing of the 16S rRNA gene, we characterized the microbiome present in the gills and guts of these species recruited from an impacted SFR region and hatchery tanks (HT). Our results showed that bacterial diversity from the gill and gut at the genera level in both fish species from HT is 87% smaller than in species from the SFR. Furthermore, only 15 and 29% of bacterial genera are shared between gills and guts in R. aspera and P. argenteus from SFR, respectively, showing an intimate relationship between functional differences in organs. In both species from SFR, pathogenic, xenobiont-degrading, and cyanotoxin-producer bacterial genera were found, indicating the critical pollution scenario in which the river finds itself. This study allowed us to conclude that the conditions imposed on fish in the HT act as important modulators of microbial diversity in the analyzed tissues. It also raises questions regarding the effects of these conditions on hatchery spawn fish and their suitability for restocking activities, aggravated by the narrow genetic diversity associated with such freshwater systems.Item Toxicogenetic and antiproliferative effects of chrysin in urinary bladder cancer cells.(2020) Lima, Ana Paula Braga; Almeida, Tamires Cunha; Barros, Tatiane Martins Barcelos; Rocha, Lorrana Cachuite Mendes; Garcia, Camila Carrião Machado; Silva, Glenda Nicioli daThe antitumour activity of chrysin have been studied in several types of cancer cells. In urinary bladder cancer, its cytotoxic effects have already demonstrated; however, its mechanism of action is not completely understood and the role of tumour protein p53 (TP53) gene in these effects is unclear. In this study, we investigated the role of chrysin (10, 20, 40, 60 80 and 100 µM) in progression of bladder tumour cells with different status of the TP53 gene and different degrees of tumour (RT4, grade 1, TP53 wild type; 5637, grade 2, TP53 mutated and T24, grade 3, TP53 mutated). Results demonstrated that chrysin inhibited cell proliferation by increasing reactive oxygen species and DNA damage and inhibited cell migration in all cell lines. In TP53 wild-type cells, a sub-G1 apoptotic population was present. In mutated TP53 cells, chrysin caused arrest at the G2/M phase and morphological changes accompanied by downregulation of PLK1, SRC and HOXB3 genes. In addition, in Grade 2 cells, chrysin induced global DNA hypermethylation and, in the highest-grade cells, downregulated c-MYC, FGFR3 and mTOR gene expression. In conclusion, chrysin has antiproliferative and toxicogenetic activity in bladder tumour cells independently of TP53 status; however, the mechanisms of action are dependent on TP53 status.