Interaction with human plasminogen system turns on proteolytic activity in Streptococcus agalactiae and enhances its virulence in a mouse model

Interactions of several microbial pathogens with the plasminogen system increase their invasive potential. In this study, we show that Streptococcus agalactiae binds human plasminogen which can be subsequently activated to plasmin, thus generating a proteolytic bacterium. S. agalactiae binds plasminogen via the direct pathway, using plasminogen receptors, and via the indirect pathway through fibrinogen receptors. The glyceraldehyde-3-phosphate dehydrogenase is one If the S. agalactiae proteins that bind plasminogen. Presence of exogenous activators such as uPA and tPA are required to activate bound plasminogen. Results from competitive inhibition assays indicate that binding is partially mediated through the lysine binding sites of plasminogen. Following plasminogen binding and activation, S. agalactiae is able to degrade in vitro fibronectin, one of the host extracellular matrix proteins. Moreover, incubation of S. agalactiae with either plasminogen alone, or plasminogen plus fibrinogen, in the presence of tPA enhanced its virulence in C57BL/6 mice, suggesting that acquisition of plasmin-like activity by the bacteria increase their invasiveness

Exploring bioactive properties of marine cyanobacteria Isolated from the Portuguese coast: high potential as a source of anticancer compounds

The oceans remain a major source of natural compounds with potential in pharmacology. In particular, during the last few decades, marine cyanobacteria have been in focus as producers of interesting bioactive compounds, especially for the treatment of cancer. In this study, the anticancer potential of extracts from twenty eight marine cyanobacteria strains, belonging to the underexplored picoplanktonic genera, Cyanobium, Synechocystis and Synechococcus, and the filamentous genera, Nodosilinea, Leptolyngbya, Pseudanabaena and Romeria, were assessed in eight human tumor cell lines. First, a crude extract was obtained by dichloromethane:methanol extraction, and from it, three fractions were separated in a Si column chromatography. The crude extract and fractions were tested in eight human cancer cell lines for cell viability/toxicity, accessed with the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and lactic dehydrogenase release (LDH) assays. Eight point nine percent of the strains revealed strong cytotoxicity; 17.8% showed moderate cytotoxicity, and 14.3% assays showed low toxicity. The results obtained revealed that the studied genera of marine cyanobacteria are a promising source of novel compounds with potential anticancer activity and highlight the interest in also exploring the smaller filamentous and picoplanktonic genera of cyanobacteria.This research was supported by the European Regional Development Fund (ERDF) through the COMPETE - Operational Competitiveness Programme and national funds through FCT – Foundation for Science and Technology, under the project PTDC/MAR/102638/2008

Interaction with human plasminogen system turns on proteolytic activity in Streptococcus agalactiae and enhances its virulence in a mouse model

Interactions of several microbial pathogens with the plasminogen system increase their invasive potential. In this study, we show that Streptococcus agalactiae binds human plasminogen which can be subsequently activated to plasmin, thus generating a proteolytic bacterium. S. agalactiae binds plasminogen via the direct pathway, using plasminogen receptors, and via the indirect pathway through fibrinogen receptors. The glyceraldehyde-3-phosphate dehydrogenase is one If the S. agalactiae proteins that bind plasminogen. Presence of exogenous activators such as uPA and tPA are required to activate bound plasminogen. Results from competitive inhibition assays indicate that binding is partially mediated through the lysine binding sites of plasminogen. Following plasminogen binding and activation, S. agalactiae is able to degrade in vitro fibronectin, one of the host extracellular matrix proteins. Moreover, incubation of S. agalactiae with either plasminogen alone, or plasminogen plus fibrinogen, in the presence of tPA enhanced its virulence in C57BL/6 mice, suggesting that acquisition of plasmin-like activity by the bacteria increase their invasiveness

Investigação sobre o mercado de trabalho para o bibliotecário na internet: relato de pesquisa em andamento

Preliminary results of a research about Internet market-place in Brasilia, DF (Brazil)data were collected through interviews submitted to librarians graduate at UnB in the period 1995-1997. Additional data were collected at library site observation.Trata-se de um relato de pesquisa em andamento sobre mercado de trabalho na Internet. Mostra resultados preliminares obtidos sobre as atividades dos bibliotecários que foram coletados por meio de entrevistas com os profissionais formados pela Universidade de Brasília no período de 1995 a 2000 e por meio da observação de sites de biblioteca de Brasília, DF

Avaliação da efetividade de intervenções de promoção da atividade física no Sistema Único de Saúde

OBJECTIVE To assess the effect of interventions on the levels of physical activity of healthy adults, users of the Brazilian Unified Health System and attended by the Family Health Strategy. METHODS Non-randomized experimental study with 157 adults allocated in three groups: 1) physical exercise classes (n = 54), 2) health education (n = 54), 3) control (n = 49). The study lasted for18 months, with 12 months of interventions and six months of follow-up after intervention. Assessments took place at the beginning, in the 12 months, and in the 18 months of study. Physical activity has been assessed by questionnaires and accelerometry. For the analyses, we have used the intention-to-treat principle and generalized estimating equations. RESULTS After 12 months, both intervention groups have increased the minutes of weekly leisure time physical activity and annual scores of physical exercise, leisure and transport-related physical activity. The exercise class group has obtained the highest average annual physical exercises score when compared to the other groups (p < 0.001). In the follow-up period, the exercise class group reduced its annual score (average: -0.3; 95%CI -0.5–-0.1), while the health education group increased this score (average: 0.2; 95%CI 0.1–0.4). There have been no differences in the levels of physical activity measured by accelerometry. CONCLUSIONS The interventions have been effective in increasing the practice of physical activity. However, we have observed that the health education intervention was more effective for maintaining the practice of physical activity in the period after intervention. We recommend the use of both interventions to promote physical activity in the Brazilian Unified Health System, according to the local reality of professionals, facilities, and team objectives.OBJETIVO Avaliar o efeito de intervenções nos níveis de atividade física de adultos saudáveis, usuários do Sistema Único de Saúde e atendidos pela Estratégia de Saúde da Família. MÉTODOS Estudo experimental, não randomizado, com 157 adultos alocados em três grupos: 1) classes de exercícios físicos (n = 54); 2) educação em saúde (n = 54); 3) controle (n = 49). O estudo teve duração de 18 meses, sendo 12 meses de intervenções e seis meses de acompanhamento pós-intervenção. As avaliações ocorreram no início, nos 12 e nos 18 meses de estudo. A atividade física foi avaliada por questionários e por acelerometria. Para as análises, utilizaram-se o princípio de intenção de tratar e equações de estimativas generalizadas. RESULTADOS Após 12 meses, ambos os grupos de intervenção aumentaram os minutos semanais de atividade física no lazer e os escores anuais de exercícios físicos, de lazer e de deslocamento. O grupo das classes de exercícios físicos obteve maior média de escore anual de exercícios físicos em comparação com os outros grupos (p < 0,001). No período pós-intervenção, o grupo de classes de exercícios físicos reduziu o escore anual de exercícios físicos (média: -0,3; IC95% -0,5–-0,1), enquanto o grupo de educação em saúde aumentou este escore (média: 0,2; IC95% 0,1–0,4). Não houve diferenças nos níveis de atividade física mensurados por acelerometria. CONCLUSÕES As intervenções foram efetivas para aumentar a prática de atividade física. No entanto, observou-se que a intervenção de educação em saúde foi mais efetiva para a manutenção da prática de atividade física no período pós-intervenção. Recomenda-se a utilização de ambas as intervenções para a promoção da atividade física no Sistema Único de Saúde, de acordo com as realidades locais de profissionais, instalações e objetivos das equipes

Assessment of the effectiveness of physical activity interventions in the Brazilian Unified Health System.

OBJECTIVE: To assess the effect of interventions on the levels of physical activity of healthy adults, users of the Brazilian Unified Health System and attended by the Family Health Strategy. METHODS: Non-randomized experimental study with 157 adults allocated in three groups: 1) physical exercise classes (n = 54), 2) health education (n = 54), 3) control (n = 49). The study lasted for18 months, with 12 months of interventions and six months of follow-up after intervention. Assessments took place at the beginning, in the 12 months, and in the 18 months of study. Physical activity has been assessed by questionnaires and accelerometry. For the analyses, we have used the intention-to-treat principle and generalized estimating equations. RESULTS: After 12 months, both intervention groups have increased the minutes of weekly leisure time physical activity and annual scores of physical exercise, leisure and transport-related physical activity. The exercise class group has obtained the highest average annual physical exercises score when compared to the other groups (p < 0.001). In the follow-up period, the exercise class group reduced its annual score (average: -0.3; 95%CI -0.5--0.1), while the health education group increased this score (average: 0.2; 95%CI 0.1-0.4). There have been no differences in the levels of physical activity measured by accelerometry. CONCLUSIONS: The interventions have been effective in increasing the practice of physical activity. However, we have observed that the health education intervention was more effective for maintaining the practice of physical activity in the period after intervention. We recommend the use of both interventions to promote physical activity in the Brazilian Unified Health System, according to the local reality of professionals, facilities, and team objectives. OBJETIVO: Avaliar o efeito de intervenções nos níveis de atividade física de adultos saudáveis, usuários do Sistema Único de Saúde e atendidos pela Estratégia de Saúde da Família. MÉTODOS: Estudo experimental, não randomizado, com 157 adultos alocados em três grupos: 1) classes de exercícios físicos (n = 54); 2) educação em saúde (n = 54); 3) controle (n = 49). O estudo teve duração de 18 meses, sendo 12 meses de intervenções e seis meses de acompanhamento pós-intervenção. As avaliações ocorreram no início, nos 12 e nos 18 meses de estudo. A atividade física foi avaliada por questionários e por acelerometria. Para as análises, utilizaram-se o princípio de intenção de tratar e equações de estimativas generalizadas. RESULTADOS: Após 12 meses, ambos os grupos de intervenção aumentaram os minutos semanais de atividade física no lazer e os escores anuais de exercícios físicos, de lazer e de deslocamento. O grupo das classes de exercícios físicos obteve maior média de escore anual de exercícios físicos em comparação com os outros grupos (p < 0,001). No período pós-intervenção, o grupo de classes de exercícios físicos reduziu o escore anual de exercícios físicos (média: -0,3; IC95% -0,5--0,1), enquanto o grupo de educação em saúde aumentou este escore (média: 0,2; IC95% 0,1-0,4). Não houve diferenças nos níveis de atividade física mensurados por acelerometria. CONCLUSÕES: As intervenções foram efetivas para aumentar a prática de atividade física. No entanto, observou-se que a intervenção de educação em saúde foi mais efetiva para a manutenção da prática de atividade física no período pós-intervenção. Recomenda-se a utilização de ambas as intervenções para a promoção da atividade física no Sistema Único de Saúde, de acordo com as realidades locais de profissionais, instalações e objetivos das equipes

Phosphate solubilization and synergism between P-solubilizing and arbuscular mycorrhizal fungi

O objetivo deste trabalho foi avaliar a capacidade de solubilização de fosfato de alumínio e apatita de Araxá por diversos isolados de fungos solubilizadores de fosfato e o sinergismo entre o fungo solubilizador de fosfato, FSF 7, e fungos micorrízicos arbusculares, na promoção do crescimento de trevo fertilizado com fosfato de alumínio. Dois experimentos foram conduzidos, o primeiro em laboratório e o segundo em câmaras de cultivo. No primeiro experimento, os isolados FSF 7, FSF 9, FSF 21 e FSF 22, mais controle foram incubados em meio líquido, sob agitação, a 28ºC, por oito dias. Avaliou-se o pH e P solúvel no segundo, quarto e oitavo dia de incubação. No segundo experimento, semeou-se trevo em copos de plástico contendo 300 g de substrato esterilizado, fertilizado com fosfato de alumínio, 3 g L-1, com e sem FSF 7 e fungos micorrízicos. O delineamento foi inteiramente casualizado, esquema fatorial 2x2 (presença e ausência de FSF 7 e fungos micorrízicos), com cinco repetições. No primeiro experimento, foram encontradas maiores quantidades de P solúvel no meio contendo fosfato de alumínio. O FSF 7 aumentou a solubilização desse fosfato. O crescimento do trevo foi favorecido pela presença do FSF 7 e fungos micorrízicos arbusculares, o que evidencia sinergismo entre esses microrganismos.The objective of this work was to evaluate the ability of several P-solubilizing fungi to solubilize aluminum phosphate and Araxá apatite as well as the synergism between the P-solubilizing fungus, PSF 7, and arbuscular mycorrhizal fungi to promote clover growth amended with aluminum phosphate. Two experiments were carried out, the first under laboratory conditions and the second in a controlled environmental chamber. In the first experiment, PSF 7, PSF 9, PSF 21 and PSF 22 isolates plus control were incubated in liquid medium at 28ºC for eight days. On the 2nd, 4th and 8th day of incubation, pH and soluble P were determined. In the second experiment, clover was sowed in plastic pots containing 300 g of sterilized substrate amended with aluminum phosphate, 3 g L-1, in presence and absence of PSF 7 isolate and arbuscular mycorrhizal fungi. A completely randomized design, in factorial outline 2x2 (presence and absence of PSF 7 and arbuscular mycorrhizal fungi) and five replicates were used. In the first experiment, higher P content was detected in the medium containing aluminum phosphate. PSF 7 is the best fungi isolate which increases aluminum solubilization with major tolerance to Al3+. Clover growth was stimulated by presence of PSF 7 and arbuscular mycorrhizal fungi. There is synergism between microorganisms utilized to improve plant nutrition

GM2-gangliosidosis B1 variant: analysis of beta-hexosaminidase alpha gene mutations in 11 patients from a defined region in Portugal.

The GM2-gangliosidosis B1 variant occurs at an exceptionally high frequency in the northern part of Portugal. In most patients, the disease manifests itself as a juvenile form, as opposed to the late-infantile form described for many patients from other parts of the world. We have analyzed the beta-hexosaminidase alpha gene in 11 patients, as well as in some relatives, in order to characterize the underlying abnormalities. They were screened for the two previously identified mutations responsible for the B1 variant phenotype (G533----A, also designated as the "DN allele," and C532---T) by PCR amplification of an 800-bp DNA fragment and subsequent dot-blot hybridization with allele-specific oligonucleotides. The fragment amplified from one patient was also subcloned and sequenced. Ten patients, constituting a clinically and biochemically homogeneous group, were found to be homozygous for the DN allele. The other, whose clinical profile more resembled the late-infantile phenotype often described in the literature, was a compound heterozygote carrying the DN allele and another, as yet unidentified, abnormal allele. Our results, corroborated by previously published data, suggest that homozygotes and compound heterozygotes for the DN allele may be distinguishable at the phenotypic level, depending on the nature of the abnormality in the other allele. A common ancestral origin for the DN allele can also be postulated

Phosphate solubilization in solid and liquid media by soil bacteria and fungi

O objetivo deste trabalho foi avaliar a capacidade e a eficiência de solubilização de CaHPO4, AlPO4 e apatita de Araxá em meio sólido, e de AlPO4 e apatita de Araxá em meio líquido, por fungos (Aspergillus) e bactérias (Enterobacteriaceae) do solo. Em meio sólido, todos solubilizaram CaHPO4, nenhum solubilizou apatita de Araxá e apenas o isolado de fungo FSF 7 solubilizou AlPO4. Em meio líquido, todos solubilizaram AlPO4 e apatita de Araxá. A seleção de solubilizadores deve ser feita com a quantificação do potencial de solubilização em meio líquido.The objective of this work was to evaluate the ability and efficiency of solubilization of CaHPO4, AlPO4 and Araxá apatite in solid medium, and AlPO4 and Araxá apatite in liquid medium. Soil P-solubilizing fungi (Aspergillus) and P-solubilizing bacteria (Enterobacteriaceae) were tested. In solid medium, all isolates solubilized CaHPO4, not any isolate solubilized Araxá apatite, and one fungus isolate (PSF 7) solubilized AlPO4. In liquid medium, all isolates solubilized AlPO4 and Araxá apatite. Screening of P-solubilizing microorganisms must be done by quantifying their potential of phosphate solubilization in liquid growth medium

Phosphate solubilization in solid and liquid media by soil bacteria and fungi

O objetivo deste trabalho foi avaliar a capacidade e a eficiência de solubilização de CaHPO4, AlPO4 e apatita de Araxá em meio sólido, e de AlPO4 e apatita de Araxá em meio líquido, por fungos (Aspergillus) e bactérias (Enterobacteriaceae) do solo. Em meio sólido, todos solubilizaram CaHPO4, nenhum solubilizou apatita de Araxá e apenas o isolado de fungo FSF 7 solubilizou AlPO4. Em meio líquido, todos solubilizaram AlPO4 e apatita de Araxá. A seleção de solubilizadores deve ser feita com a quantificação do potencial de solubilização em meio líquido.The objective of this work was to evaluate the ability and efficiency of solubilization of CaHPO4, AlPO4 and Araxá apatite in solid medium, and AlPO4 and Araxá apatite in liquid medium. Soil P-solubilizing fungi (Aspergillus) and P-solubilizing bacteria (Enterobacteriaceae) were tested. In solid medium, all isolates solubilized CaHPO4, not any isolate solubilized Araxá apatite, and one fungus isolate (PSF 7) solubilized AlPO4. In liquid medium, all isolates solubilized AlPO4 and Araxá apatite. Screening of P-solubilizing microorganisms must be done by quantifying their potential of phosphate solubilization in liquid growth medium