Cryopreservation of immature bovine oocytes with 1,2 propanediol

O objetivo deste trabalho foi avaliar o efeito de dois gradientes de concentrações de 1,2 propanediol (PROH) na criopreservação de ovócitos imaturos, envoltos em células do cumulus, de bovinos abatidos em matadouro. No tratamento 1, com uso de 1,6 M de PROH, os ovócitos foram desidratados em três etapas crescentes (0,53; 1,06 e 1,6 M), à temperatura ambiente e congelados em nitrogênio líquido. A descongelação foi realizada em água a 37ºC por 30 segundos e a reidratação em três etapas decrescentes (1,6; 1,06 e 0,53 M), acrescidos de 0,25 M de sacarose cada. No tratamento 2 foi utilizado 2,0 M de PROH, de maneira semelhante ao tratamento 1, com desidratação contendo 0,7; 1,4 e 2,0 M, e reidratação 2,0; 1,4 e 0,7 M. Após a reidratação, os ovócitos foram lavados em meio TCM 199 (Meio de Cultivo para Tecidos) e levados para maturação in vitro. O grupo controle foi constituído de ovócitos recém-colhidos. Os ovócitos foram colocados para maturar por 24 horas, em meio TCM 199 com 10% de SVC (Soro de Vaca em Cio) e FSH (Hormônio Estimulante de Folículo), em co-cultura com células da granulosa, com 5% CO2 no ar a 39ºC. Os resultados de maturação nuclear foram diferentes (P<0,05) entre os ovócitos criopreservados e controle, sendo 2,04%, 0% e 84% para o tratamento 1, 2 e controle, respectivamente.A study was carried out to investigate the ability of immature bovine cumulus-oocytes complexes to survive cryopreservation and undergo subsequent in vitro maturation in two different levels of propanediol (PROH). Treatment 1 consisted of subjecting oocytes to a gradual 3-step, concentration-driven dehydration with PROH (0.53; 1.06 and 1.6 M) at room temperature and subsequent freezing. Oocytes were thawed in water at 37ºC for 30 seconds and subjected to a gradual 3-step, concentration-driven rehydration with PROH (1.6; 1.06 and 0.53 M) in the presence of 0.25 M sucrose. Treatment 2 was conducted the same way, but PROH concentrations for dehydration were 0.7; 1.4 and 2.0 M and for rehydration were 2.0; 1.4 and 0.7 M. After rehydration, oocytes of both treatments were washed in TCM 199 medium followed by the in vitro maturation. The control consisted of nonfrozen oocytes. Oocytes of all groups were cultured in TCM 199 medium with 10% ECS and FSH, and 5% CO2 air in co-culture at 39ºC, for 24 hours. The in vitro maturation rate of cryopreserved oocytes were different for treatments and control. Metafase II was reached by 2.04%, 0% and 84% for treatment 1, 2 and control, respectively

The complete genome sequence of Chromobacterium violaceum reveals remarkable and exploitable bacterial adaptability

Chromobacterium violaceum is one of millions of species of free-living microorganisms that populate the soil and water in the extant areas of tropical biodiversity around the world. Its complete genome sequence reveals (i) extensive alternative pathways for energy generation, (ii) ≈500 ORFs for transport-related proteins, (iii) complex and extensive systems for stress adaptation and motility, and (iv) wide-spread utilization of quorum sensing for control of inducible systems, all of which underpin the versatility and adaptability of the organism. The genome also contains extensive but incomplete arrays of ORFs coding for proteins associated with mammalian pathogenicity, possibly involved in the occasional but often fatal cases of human C. violaceum infection. There is, in addition, a series of previously unknown but important enzymes and secondary metabolites including paraquat-inducible proteins, drug and heavy-metal-resistance proteins, multiple chitinases, and proteins for the detoxification of xenobiotics that may have biotechnological applications

Uso do Método Delphi para validação de conteúdo e confiabilidade de uma escala sobre bullying e desengajamento moral

Embora a associação entre as variáveis bullying escolar e desengajamento moral sejam amplamente exploradas, ainda não existem instrumentos de pesquisa validados para uso no contexto brasileiro nessa direção. Assim, esse estudo objetivou apresentar o Método Delphi e uma situação de sua aplicação no processo de adaptação e validação de uma escala sobre bullying e desengajamento moral. O painel de especialistas incluiu três enfermeiras, um psicólogo, uma médica, uma professora de biologia e uma professora de educação física. Todos os participantes eram Ph.D e investigavam questões relacionadas ao bullying a mais de 5 anos. A escala foi avaliada em quatro dimensões: objetividade, simplicidade, clareza e credibilidade. Os dados foram tabulados utilizando-se o programa Microsoft Excel e a estatística descritiva permitiu definir os índices de validade de conteúdo e fidedignidade. O índice de validade de conteúdo atingiu a pontuação máxima (100.0%) nas quatro dimensões avaliadas. A verificação de fidedignidade demonstrou desempenho médio de 94.0%. Após o uso do Método Delphi foi proposta uma versão final, em português, da escala sobre bullying e desengajamento moral. O ponto forte do estudo reside na apresentação e aplicação rigorosa do Método Delphi

GC-MS Profile and Enhancement of Antibiotic Activity by the Essential Oil of Ocotea odorífera and Safrole: Inhibition of Staphylococcus aureus Efflux Pumps

Considering the evidence that essential oils, as well as safrole, could modulate bacterial growth in different resistant strains, this study aims to characterize the phytochemical profile and evaluate the antibacterial and antibiotic-modulating properties of the essential oil Ocotea odor&iacute;fera (EOOO) and safrole against efflux pump (EP)-carrying strains. The EOOO was extracted by hydrodistillation, and the phytochemical analysis was performed by gas chromatography coupled to mass spectrometry (GC-MS). The antibacterial and antibiotic-modulating activities of the EOOO and safrole against resistant strains of Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa were analyzed through the broth microdilution method. The EP-inhibiting potential of safrole in association with ethidium bromide or antibiotics was evaluated using the S. aureus 1199B and K2068 strains, which carry genes encoding efflux proteins associated with antibiotic resistance to norfloxacin and ciprofloxacin, respectively. A reduction in the MIC of ethidium bromide or antibiotics was used as a parameter of EP inhibition. The phytochemical analysis identified 16 different compounds in the EOOO including safrole as the principal constituent. While the EOOO and safrole exerted clinically relevant antibacterial effects against S. aureus only, they potentiated the antibacterial activity of norfloxacin against all strains evaluated by our study. The ethidium bromide and antibiotic assays using the strains of S. aureus SA1119B and K2068, as well as molecular docking analysis, indicated that safrole inhibits the NorA and MepA efflux pumps in S. aureus. In conclusion, Ocotea odorifera and safrole presented promising antibacterial and antibiotic-enhancing properties, which should be explored in the development of drugs to combat antibacterial resistance, especially in strains bearing genes encoding efflux proteins