Chemical constituents of the underground stem bark of Duguetia furfuracea (Annonaceae)

In the present investigation the underground parts of Duguetia furfuracea (Annonaceae) were used to conduct a phytochemical study that included the brine shrimp (Artemia salina) lethality bioassay. The substances (-)-duguetine beta-N-oxide, (-)-duguetine, dicentrinone, (-)-N-methyltetrahydropalmatine, and (+)-N-methylglaucine were isolated from the alkaloid extract of the bark of the underground stem, and the ureide allantoin was also isolated by precipitation from the ethanol extract of the wood of the underground stem. A fresh volatile oil and a nonpolar extract were also obtained from the underground stem bark. The substances 2,4,5-trimethoxystyrene, a-gurjunene, aromadendrene, bicyclogermacrene, (E)-methylisoeugenol, and alpha-asarone were isolated from the fresh volatile oil and polycarpol, beta-caryophyllene oxide, 2,4,5-trimethoxystyrene, a-asarone, and asaraldehyde were obtained from the petroleum ether extract. The present study describes for the first time the alkaloid (-)-duguetine beta-N-oxide and the occurrence of (-)-N-methyltetrahydropalmatine and (+)-N-methylglaucine in the family Annonaceae. All extracts were active in the brine shrimp lethality bioassay

An environmentally benign antimicrobial nanoparticle based on a silver-infused lignin core

Silver nanoparticles have antibacterial properties, but their use has been a cause for concern because they persist in the environment. Here, we show that lignin nanoparticles infused with silver ions and coated with a cationic polyelectrolyte layer form a biodegradable and green alternative to silver nanoparticles. The polyelectrolyte layer promotes the adhesion of the particles to bacterial cell membranes and, together with silver ions, can kill a broad spectrum of bacteria, including Escherichia coli, Pseudomonas aeruginosa and quaternary-amine-resistant Ralstonia sp. Ion depletion studies have shown that the bioactivity of these nanoparticles is time-limited because of the desorption of silver ions. High-throughput bioactivity screening did not reveal increased toxicity of the particles when compared to an equivalent mass of metallic silver nanoparticles or silver nitrate solution. Our results demonstrate that the application of green chemistry principles may allow the synthesis of nanoparticles with biodegradable cores that have higher antimicrobial activity and smaller environmental impact than metallic silver nanoparticles

A DiCre recombinase-based system for inducible expression in Leishmania major

Here we present the establishment of an inducible system based on the dimerizable Cre recombinase (DiCre) for controlled gene expression in the protozoan parasite Leishmania. Rapamycin-induced DiCre activation promoted efficient flipping and expression of gene products in a time and dose-dependent manner. The DiCre flipping activity induced the expression of target genes from both integrated and episomal contexts broadening the applicability of the system. We validated the system by inducing the expression of both full length and truncated forms of the checkpoint protein Rad9, which revealed that the highly divergent C-terminal domain of Rad9 is necessary for proper subcellular localization. Thus, by establishing the DiCre-based inducible system we have created and validated a robust new tool for assessing gene function in Leishmania

Falls among older adults in the South of Brazil: prevalence and determinants

OBJETIVO: Avaliar a prevalência e os fatores associados à ocorrência de quedas em idosos. MÉTODOS: Estudo transversal com amostra representativa de 1.451 idosos residentes na zona urbana de Pelotas, RS, em 2014. Foi realizada análise descritiva dos dados e apresentada a prevalência de quedas no último ano. A análise de fatores demográficos, socioeconômicos, comportamentais e de saúde associados ao desfecho foi realizada por meio de regressão de Poisson com ajuste para variância robusta conforme modelo hierárquico. As variáveis foram ajustadas entre si dentro de cada nível e para as de nível superior. Aquelas com p ≤ 0,20 foram mantidas no modelo para controle de confusão e aquelas com p < 0,05 foram consideradas associadas ao desfecho. RESULTADOS: A prevalência de quedas em idosos no último ano foi de 28,1% (IC95% 25,9–30,5), e a maioria ocorreu na própria residência do idoso. Entre os idosos que sofreram queda, 51,5% (IC95% 46,6–56,4) tiveram uma única queda e 12,1% (IC95% 8,9–15,3) tiveram fratura como consequência, sendo a de membros inferiores a mais relatada. A prevalência de quedas foi maior em mulheres, idosos com idade avançada, de menor renda e escolaridade, com incapacidade funcional para atividades instrumentais e portadores de enfermidades como diabetes, doença cardíaca e artrite. CONCLUSÕES: A ocorrência de quedas atingiu quase um terço dos idosos, e a prevalência foi mais elevada em segmentos específicos da população em questão. Cerca de 12% dos idosos que caíram, fraturaram algum osso. Os fatores associados à ocorrência de quedas identificados neste estudo poderão nortear medidas que visem sua prevenção na população de idosos.OBJECTIVE: Evaluate the prevalence and the factors associated with the occurrence of falls among older adults. METHODS: A cross-sectional study with a representative sample of 1,451 elderly residents in the urban area of Pelotas, RS, in 2014. A descriptive analysis of the data was performed and the prevalence of falls in the last year was presented. The analysis of demographic, socioeconomic, behavioral and health factors associated with the outcome was performed using Poisson regression with adjustment for robust variance according to the hierarchical model. The variables were adjusted to each other within each level and for the higher level. Those with p ≤ 0.20 were maintained in the model for confounding control and those with p < 0.05 were considered to be associated with the outcome. RESULTS: The prevalence of falls among older adults in the last year was 28.1% (95%CI 25.9–30.5), and most occurred in the person’s own residence. Among the older adults who fell, 51.5% (95%CI 46.6–56.4) had a single fall and 12.1% (95%CI 8.9–15.3) had a fracture as a consequence, usually in the lower limbs. The prevalence of falls was higher in women, adults of advanced age, with lower income and schooling level, with functional incapacity for instrumental activities, and patients with diseases such as diabetes, heart disease, and arthritis. CONCLUSIONS: The occurrence of falls reached almost a third of the older adults, and the prevalence was higher in specific segments of the population in question. About 12% of the older adults who fell fractured some bone. The factors associated with the occurrence of falls identified in this study may guide measures aimed at prevention in the older adult population

Longitudinal assessment of cognitive and psychosocial functioning after Hurricanes Katrina and Rita: Exploring disaster impact on middle-aged, older, and oldest-old adults

The authors examined the effects of Hurricanes Katrina and Rita on cognitive and psychosocial functioning in a lifespan sample of adults 6-14 months after the storms. Participants were recruited from the Louisiana Healthy Aging Study. Most were assessed during the immediate impact period and retested for this study. Analyses of pre- and post-disaster cognitive data confirmed that storm-related decrements in working memory for middle-aged and older adults observed in the immediate impact period had returned to pre-hurricane levels in the post-disaster recovery period. Middle-aged adults reported more storm-related stressors and greater levels of stress than the two older groups at both waves of testing. These results are consistent with a burden perspective on post-disaster psychological reactions. © 2012 Wiley Periodicals, Inc

Bacterial strains from floodplain soils perform different plant-growth promoting processes and enhance cowpea growth

ABSTRACT Certain nodulating nitrogen-fixing bacteria in legumes and other nodule endophytes perform different plant-growth promoting processes. The objective of this study was to evaluate 26 bacterial strains isolated from cowpea nodules grown in floodplain soils in the Brazilian savannas, regarding performance of plant-growth promoting processes and ability to enhance cowpea growth. We also identified these strains by 16S rRNA sequencing. The following processes were evaluated: free-living biological nitrogen fixation (BNF), solubilization of calcium, aluminum and iron phosphates and production of indole-3-acetic acid (IAA). The abilities to nodulate and promote cowpea growth were evaluated in Leonard jars. Partial sequencing of the 16S rRNA gene identified 60 % of the strains as belonging to genus Paenibacillus. The following four genera were also identified: Bacillus, Bradyrhizobium, Enterobacter and Pseudomonas. None of the strains fixed N2 free-living. Among the strains, 80 % solubilized Ca phosphate and one solubilized Al phosphate and none solubilized Fe phosphate. The highest IAA concentrations (52.37, 51.52 and 51.00 μg mL−1) were obtained in the 79 medium with tryptophan by Enterobacter strains UFPI B5-7A, UFPI B5-4 and UFPI B5-6, respectively. Only eight strains nodulated cowpea, however, all increased production of total dry matter. The fact that the strains evaluated perform different biological processes to promote plant growth indicates that these strains have potential use in agricultural crops to increase production and environmental sustainability

Heterokaryon Incompatibility Is Suppressed Following Conidial Anastomosis Tube Fusion in a Fungal Plant Pathogen

It has been hypothesized that horizontal gene/chromosome transfer and parasexual recombination following hyphal fusion between different strains may contribute to the emergence of wide genetic variability in plant pathogenic and other fungi. However, the significance of vegetative (heterokaryon) incompatibility responses, which commonly result in cell death, in preventing these processes is not known. In this study, we have assessed this issue following different types of hyphal fusion during colony initiation and in the mature colony. We used vegetatively compatible and incompatible strains of the common bean pathogen Colletotrichum lindemuthianum in which nuclei were labelled with either a green or red fluorescent protein in order to microscopically monitor the fates of nuclei and heterokaryotic cells following hyphal fusion. As opposed to fusion of hyphae in mature colonies that resulted in cell death within 3 h, fusions by conidial anastomosis tubes (CAT) between two incompatible strains during colony initiation did not induce the vegetative incompatibility response. Instead, fused conidia and germlings survived and formed heterokaryotic colonies that in turn produced uninucleate conidia that germinated to form colonies with phenotypic features different to those of either parental strain. Our results demonstrate that the vegetative incompatibility response is suppressed during colony initiation in C. lindemuthianum. Thus, CAT fusion may allow asexual fungi to increase their genetic diversity, and to acquire new pathogenic traits