Halistanol sulfate A and rodriguesines A and B are antimicrobial and antibiofilm agents against the cariogenic bacterium Streptococcus mutans

AbstractIn the present investigation we report the antibacterial activity of halistanol sulfate A isolated from the sponge Petromica ciocalyptoides, as well as of rodriguesines A and B isolated from the ascidian Didemnum sp., against the caries etiologic agent Streptococcus mutans. The transcription levels of S. mutans virulence genes gtfB, gtfC and gbpB, as well as of housekeeping genes groEL and 16S, were evaluated by sqRT-PCR analysis of S. mutans planktonic cells. There were no alterations in the expression levels of groEL and 16S after antimicrobial treatment with halistanol sulfate A and with rodriguesines A and B, but the expression of the genes gtfB, gtfC and gbpB was down-regulated. Halistanol sulfate A displayed the most potent antimicrobial effect against S. mutans, with inhibition of biofilm formation and reduction of biofilm-associated gene expression in planktonic cells. Halistanol sulfate A also inhibited the initial oral bacteria colonizers, such as Streptococcus sanguinis, but at much higher concentrations. The results obtained indicate that halistanol sulfate A may be considered a potential scaffold for drug development in Streptococcus mutans antibiofilm therapy, the main etiologic agent of human dental caries

MnO2-Ir Nanowires: Combining Ultrasmall Nanoparticle Sizes, O-Vacancies, and Low Noble-Metal Loading with Improved Activities towards the Oxygen Reduction Reaction

"Although clean energy generation utilizing the Oxygen Reduction Reaction (ORR) can be considered a promising strategy, this approach remains challenging by the dependence on high loadings of noble metals, mainly Platinum (Pt). Therefore, efforts have been directed to develop new and efficient electrocatalysts that could decrease the Pt content (e.g., by nanotechnology tools or alloying) or replace them completely in these systems. The present investigation shows that high catalytic activity can be reached towards the ORR by employing 1.8 ± 0.7 nm Ir nanoparticles (NPs) deposited onto MnO2 nanowires surface under low Ir loadings (1.2 wt.%). Interestingly, we observed that the MnO2 -Ir nanohybrid presented high catalytic activity for the ORR close to commercial Pt/C (20.0 wt.% of Pt), indicating that it could obtain efficient performance using a simple synthetic procedure. The MnO2 -Ir electrocatalyst also showed improved stability relative to commercial Pt/C, in which only a slight activity loss was observed after 50 reaction cycles. Considering our findings, the superior performance delivered by the MnO2 -Ir nanohybrid may be related to (i) the significant concentration of reduced Mn3+ species, leading to increased concentration of oxygen vacancies at its surface; (ii) the presence of strong metal-support interactions (SMSI), in which the electronic effect between MnOx and Ir may enhance the ORR process; and (iii) the unique structure comprised by Ir ultrasmall sizes at the nanowire surface that enable the exposure of high energy surface/facets, high surface-to-volume ratios, and their uniform dispersion.

Association between deep-water scale-worms (Annelida: Polynoidae) and black corals (Cnidaria: Antipatharia) in the Southwestern Atlantic

Polynoid scale-worms have been found living as commensals with deep-water antipatharians (commonly known as black corals) in the Potiguar Basin, off Rio Grande do Norte State, Northeastern Brazil. In this paper two polychaete species and four black corals species are redescribed. Benhamipolynoe cf. antipathicola and Parahololepidella cf. greeffi, and the black coral Stylopathes adinocrada Opresko, 2006 are recorded for the Southwestern Atlantic. Benhamipolynoe cf. antipathicola was first described from off New Zealand and the Malay Archipelago, as symbiont with the black coral Stylopathes tenuispina (Silberfeld, 1909). It was later reported for the North Atlantic, off Florida, associated with Stylopathes columnaris (Duchassaing, 1870). In our study, B. cf. antipathicola was found in association with the black coral S. adinocrada. Parahololepidella cf. greeffi was first described as a free-living from shallow waters off São Tomé and Cabo Verde Islands, West Africa, and later reported as symbiont with the black coral Tanacetipathes cf. spinescens in the same location. Our data expand both the geographical distribution and the host range of this species which is reported for the first time as symbiont with Tanacetipathes barbadensis (Brook, 1889), T. tanacetum (Pourtalès, 1880) and T. thamnea (Warner, 1981) in Brazil. The aim of this study is to discuss commensal associations between two species of scale-worm polynoids and black corals found in the Southwestern Atlantic, and also reporting their global distribution. Finally, we provided an updated list of the commensal polynoids and their black coral hosts

Assessment of the tolerability and cycle control of two low-dose oral contraceptives: an open-label study

An open-label comparative study was conducted in nine centers in Brazil to evaluate the tolerability and cycle control of two low-dose oral contraceptives containing 20 mg ethynylestradiol/75 mg gestodene and 20 mg ethynylestradiol/150 mg desogestrel, during six treatment cycles. A total of 167 healthy sexually active women were enrolled (77 in the gestodene group and 90 in the desogestrel group) and 138 completed the six-cycle treatment period. A lipid and hemostatic profile was performed for a subgroup of first users. A total of 867 cycles were evaluated. Irregular bleeding did not occur in 95.4% of the cycles evaluated with gestodene and in 91.9% with desogestrel. Tolerability was good with both preparations but there was significantly more nausea in the desogestrel group. Cycle control was good with both preparations with a significantly lower incidence of irregular bleeding with gestodene when all cycles were considered. There were no clinically significant changes in the hemostatic profile. Lipid profile showed a trend to be more favorable after six cycles of treatment with both preparations. Women in the gestodene group did not present changes in the mean weight; in the desogestrel group there was a significant mean weight increase of 1 kg after six cycles of treatment. Compliance with treatment was good with both preparations. Results of this study demonstrated that low-dose preparations containing gestodene or desogestrel combined with 20 mg of ethynylestradiol are well-tolerated oral contraceptives that provide good cycle control.Realizou-se um estudo aberto comparativo em nove centros brasileiros para avaliar a tolerabilidade e o controle de ciclo obtido com o uso de dois contraceptivos orais de baixa dose contendo 20 mg etinilestradiol/75 mg gestodeno e 20 mg etinilestradiol/150 mg desogestrel, durante seis ciclos de tratamento. Foram selecionadas 167 mulheres saudáveis com vida sexual ativa (77 no grupo do gestodeno e 90 no grupo do desogestrel), das quais 138 completaram os seis ciclos de tratamento. Em um subgrupo de novas usuárias realizou-se também perfil lipídico e hemostático. Foram avaliados 867 ciclos no total. Ocorreu sangramento irregular em 4,6% dos ciclos com gestodeno e em 8,1% com desogestrel. A tolerabilidade a ambas preparações foi boa, mas houve significativamente mais náusea no grupo do desogestrel. O controle de ciclo foi bom com os dois contraceptivos, sendo que houve freqüência significativamente menor de sangramento irregular no grupo do gestodeno quando se leva em conta que todos os ciclos foram considerados. Não houve alterações clinicamente significativas no perfil hemostático. O perfil lipídico mostrou tendência a tornar-se mais favorável após seis ciclos de tratamento com as duas preparações. Não ocorreu alteração no peso médio das mulheres no grupo do gestodeno; no grupo do desogestrel houve aumento significativo no peso médio de aproximadamente 1 kg após seis meses de tratamento. A adesão ao tratamento foi boa com as duas preparações. Os resultados deste estudo mostram que preparações contendo baixa dose de gestodeno ou desogestrel associados a 20 mg de etinilestradiol são contraceptivos bem tolerados que permitem bom controle de ciclo, sem efeitos colaterais significantes.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de MedicinaUniversidade Federal da Bahia Faculdade de MedicinaSecretaria Estadual de Saúde de Goiás Hospital Materno-InfantilUniversidade Federal do Ceará Faculdade de MedicinaUniversidade de São Paulo Faculdade de MedicinaFaculdade de Ciências Médicas do Espírito SantoUniversidade Federal do Pará Faculdade de MedicinaUniversidade Federal do Pernambuco Faculdade de MedicinaUniversidade Federal da Paraíba Faculdade de MedicinaUNIFESP, EPMSciEL

Criopreservação de mórulas de camundongos por diferentes métodos: lento, vitrificação e rápido

The in vitro and in vivo development of mouse morulae after cryopreservation through different methods was examined. The slow-freezing involved an equilibration in 1.5M ethylene glycol (EG) and cooled at 0.5; 0.7; 1.0 or 1.2ºC/minute. The vitrification involved a 3 minutes equilibration in 20% EG and 60 seconds in solution containing 40% EG, 18% ficoll and 10.26% sucrose. The quick-freezing involved an equilibration in 3M EG + 0.3M sucrose for 5 minutes and 2 minutes in nitrogen vapor. In all three methods the straws were thawed in air for 10 seconds and in water at 25ºC for 20 seconds and the embryos cultured in vitro for 72 hours to estimate blastocyst rate. To assess viability in vivo, frozen morulae as well as fresh embryos were transferred into recipients. The in vitro development rates with 0.5, 0.7; 1.0 and 1.2ºC/minute were, respectively, 72.3; 79.6; 76.5 and 84.8%. There was no significant difference among the cooling rates of 0.7; 1.0 and 1.2ºC/minute (p >; 0.01). The in vitro survival rates of vitrification and quick-freezing (84.5 and 74.3%, respectively) were similar to the slow-freezing. In vivo, the implantation rate and number of fetuses from embryos frozen through slow-freezing at 1.2ºC/minute, vitrification and quick-freezing were not significantly different.Este trabalho avaliou o desenvolvimento in vitro e in vivo de mórulas de camundongos congeladas por diferentes métodos. A congelação lenta foi realizada em 1,5M de etileno glicol (EG) sendo os embriões resfriados a 0,5; 0,7; 1,0 e 1,2ºC/minuto. Na vitrificação, as mórulas foram equilibradas por 3 minutos em 20% de EG e vitrificadas em solução contendo 40% de EG, 18% de ficol e 10,26% de sacarose após 60 segundos de exposição. A congelação rápida em vapor de nitrogênio foi realizada em solução contendo 3M de EG + 0,3M de sacarose após 2 ou 5 minutos de exposição. Os embriões dos três métodos foram descongelados pela exposição das palhetas ao ar por 10 segundos e imersão em água a 25ºC por 20 segundos. Todos os embriões descongelados foram cultivados in vitro por 72 horas para avaliação da sobrevivência in vitro. Para avaliação da sobrevivência in vivo, mórulas congeladas e não congeladas (controle) foram transferidas para receptoras. O desenvolvimento in vitro nas velocidades de 0,5; 0,7; 1,0 e 1,2ºC/minuto foi, respectivamente, 72,3; 79,6; 76,5 e 84,8%. Não houve diferença estatística entre as velocidades de 0,7; 1,0 e 1,2ºC/minuto (p >; 0,01). O desenvolvimento in vitro das mórulas congeladas por vitrificação e pelo método rápido (84,5 e 74,3%, respectivamente) foi semelhante ao método lento. In vivo, a taxa de implantação e o número de fetos vivos não diferiram estatisticamente entre os grupos lento a 1,2ºC/minute, vitrificação e rápido

Cognitive development and brain gray matter susceptibility to prenatal adversities : moderation by the prefrontal cortex brain-derived neurotrophic factor gene co-expression network

Background: Previous studies focused on the relationship between prenatal conditions and neurodevelopmental outcomes later in life, but few have explored the interplay between gene co-expression networks and prenatal adversity conditions on cognitive development trajectories and gray matter density. Methods: We analyzed the moderation effects of an expression polygenic score (ePRS) for the Brain-derived Neurotrophic Factor gene network (BDNF ePRS) on the association between prenatal adversity and child cognitive development. A score based on genes co-expressed with the prefrontal cortex (PFC) BDNF was created, using the effect size of the association between the individual single nucleotide polymorphisms (SNP) and the BDNF expression in the PFC. Cognitive development trajectories of 157 young children from the Maternal Adversity, Vulnerability and Neurodevelopment (MAVAN) cohort were assessed longitudinally in 4-time points (6, 12, 18, and 36 months) using the Bayley-II mental scales. Results: Linear mixed-effects modeling indicated that BDNF ePRS moderates the effects of prenatal adversity on cognitive growth. In children with high BDNF ePRS, higher prenatal adversity was associated with slower cognitive development in comparison with those exposed to lower prenatal adversity. Parallel-Independent Component Analysis (pICA) suggested that associations of expression-based SNPs and gray matter density significantly differed between low and high prenatal adversity groups. The brain IC included areas involved in visual association processes (Brodmann area 19 and 18), reallocation of attention, and integration of information across the supramodal cortex (Brodmann area 10). Conclusion: Cognitive development trajectories and brain gray matter seem to be influenced by the interplay of prenatal environmental conditions and the expression of an important BDNF gene network that guides the growth and plasticity of neurons and synapses

Assessing the antitumor potential of variants of the extracellular carbohydrate polymer from synechocystis ΔsigF mutant

Cancer is a leading cause of death worldwide with a huge societal and economic impact. Clinically effective and less expensive anticancer agents derived from natural sources can help to overcome limitations and negative side effects of chemotherapy and radiotherapy. Previously, we showed that the extracellular carbohydrate polymer of a Synechocystis ΔsigF overproducing mutant displayed a strong antitumor activity towards several human tumor cell lines, by inducing high levels of apoptosis through p53 and caspase-3 activation. Here, the ΔsigF polymer was manipulated to obtain variants that were tested in a human melanoma (Mewo) cell line. Our results demonstrated that high molecular mass fractions were important for the polymer bioactivity, and that the reduction of the peptide content generated a variant with enhanced in vitro antitumor activity. This variant, and the original ΔsigF polymer, were further tested in vivo using the chick chorioallantoic membrane (CAM) assay. Both polymers significantly decreased xenografted CAM tumor growth and affected tumor morphology, by promoting less compact tumors, validating their antitumor potential in vivo. This work contributes with strategies for the design and testing tailored cyanobacterial extracellular polymers and further strengths the relevance of evaluating this type of polymers for biotechnological/biomedical applications.info:eu-repo/semantics/publishedVersio

Self-assembled dithiothreitol on Au surfaces for biological applications: phospholipid bilayer formation

Self-assembly of dithiothreitol (DTT) on Au(111) from solution deposition has been studied by X-ray photoelectron spectroscopy and electrochemical data. DTT molecules self-assemble on Au(111) in a lying-down configuration irrespective of the concentration and temperature. XPS and electrochemical data indicate a DTT surface coverage of y E 0.16 with two S-head–Au covalent bonds per DTT molecule. The DTT monolayer turns the Au surface hydrophilic enough to allow the formation of fluid dimyristoylphosphatidylcholine (DMPC) bilayer domains by vesicle fusion as revealed by "in situ" atomic force imaging. Methylene blue (MB) and flavin adenine dinucleotide (FAD) have been used as probes to study molecule transport across the bilayer.Facultad de Ciencias ExactasInstituto de Investigaciones Fisicoquímicas Teóricas y Aplicada