47 research outputs found

    Lifetime Paid Work and Mental Health Problems among Poor Urban 9-to-13-Year-Old Children in Brazil

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    Objective. To verify if emotional/behavioral problems are associated with lifetime paid work in poor urban children, when taking into account other potential correlates. Methods. Cross-sectional study focused on 9-to-13-year-old children (n=212). In a probabilistic sample of clusters of eligible households (women 15–49 years and son/daughter <18 years), one mother-child pair was randomly selected per household (n=813; response rate = 82.4%). CBCL/6-18 identified child emotional/behavioral problems. Potential correlates include child gender and age, socioeconomic status/SES, maternal education, parental working status, and family social isolation, among others. Multivariate analysis examined the relationship between emotional/behavioral problems and lifetime paid work in the presence of significant correlates. Findings. All work activities were non-harmful (e.g., selling fruits, helping parents at their small business, and baby sitting). Children with lower SES and socially isolated were more involved in paid work than less disadvantaged peers. Children ever exposed to paid work were four times more likely to present anxiety/depression symptoms at a clinical level compared to non-exposed children. Multivariate modeling identified three independent correlates: child pure internalizing problems, social isolation, and low SES. Conclusion. There is an association between lifetime exposure to exclusively non-harmful paid work activities and pure internalizing problems even when considering SES variability and family social isolation

    Non-linear hierarchy of the quorum sensing signalling pathway in bloodstream form African trypanosomes.

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    Trypanosoma brucei, the agents of African trypanosomiasis, undergo density-dependent differentiation in the mammalian bloodstream to prepare for transmission by tsetse flies. This involves the generation of cell-cycle arrested, quiescent, stumpy forms from proliferative slender forms. The signalling pathway responsible for the quorum sensing response has been catalogued using a genome-wide selective screen, providing a compendium of signalling protein kinases phosphatases, RNA binding proteins and hypothetical proteins. However, the ordering of these components is unknown. To piece together these components to provide a description of how stumpy formation arises we have used an extragenic suppression approach. This exploited a combinatorial gene knockout and overexpression strategy to assess whether the loss of developmental competence in null mutants of pathway components could be compensated by ectopic expression of other components. We have created null mutants for three genes in the stumpy induction factor signalling pathway (RBP7, YAK, MEKK1) and evaluated complementation by expression of RBP7, NEK17, PP1-6, or inducible gene silencing of the proposed differentiation inhibitor TbTOR4. This indicated that the signalling pathway is non-linear. Phosphoproteomic analysis focused on one pathway component, a putative MEKK, identified molecules with altered expression and phosphorylation profiles in MEKK1 null mutants, including another component in the pathway, NEK17. Our data provide a first molecular dissection of multiple components in a signal transduction cascade in trypanosomes

    Analyses of Ten Years of Scientific Production of the Journal Psicologia: Teoria e Prática

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    Launched in 1999, the journal Psicologia: Teoria e Prática, from the Faculty of Psychology and the Developmental Disorder Post graduation Program from the Mackenzie Presbyterian University is scientific instrument of dissemination in psychology and related areas. This study aims to describe its production, in addition to identify/discuss classification criteria of this journal. The results of the analysis of 213 papers published between 1999‑2009 shows that 2002 there is a predominance of authors associated to other institutions (81%). Of the total 213 articles, 19% are institutional authorship. Articles with empirical data became majority since 2003. Topics related to treatment and prevention in psychology and to social psychology were the most frequent and the average processing time was less than five months. The journal has qualis B1, according to Webqualis Capes, ranking among the top 33% in psychology

    Genome of the Avirulent Human-Infective Trypanosome—Trypanosoma rangeli

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    Background: Trypanosoma rangeli is a hemoflagellate protozoan parasite infecting humans and other wild and domestic mammals across Central and South America. It does not cause human disease, but it can be mistaken for the etiologic agent of Chagas disease, Trypanosoma cruzi. We have sequenced the T. rangeli genome to provide new tools for elucidating the distinct and intriguing biology of this species and the key pathways related to interaction with its arthropod and mammalian hosts.  Methodology/Principal Findings: The T. rangeli haploid genome is ,24 Mb in length, and is the smallest and least repetitive trypanosomatid genome sequenced thus far. This parasite genome has shorter subtelomeric sequences compared to those of T. cruzi and T. brucei; displays intraspecific karyotype variability and lacks minichromosomes. Of the predicted 7,613 protein coding sequences, functional annotations could be determined for 2,415, while 5,043 are hypothetical proteins, some with evidence of protein expression. 7,101 genes (93%) are shared with other trypanosomatids that infect humans. An ortholog of the dcl2 gene involved in the T. brucei RNAi pathway was found in T. rangeli, but the RNAi machinery is non-functional since the other genes in this pathway are pseudogenized. T. rangeli is highly susceptible to oxidative stress, a phenotype that may be explained by a smaller number of anti-oxidant defense enzymes and heatshock proteins.  Conclusions/Significance: Phylogenetic comparison of nuclear and mitochondrial genes indicates that T. rangeli and T. cruzi are equidistant from T. brucei. In addition to revealing new aspects of trypanosome co-evolution within the vertebrate and invertebrate hosts, comparative genomic analysis with pathogenic trypanosomatids provides valuable new information that can be further explored with the aim of developing better diagnostic tools and/or therapeutic targets

    High throughput chemical screening for anti-virulence developmental phenotypes in Trypanosoma brucei

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    In the bloodstream of mammalian hosts, the sleeping sickness parasite, Trypanosoma brucei, exists as a proliferative slender form or a nonproliferative, transmissible, stumpy form. The transition between these developmental forms is controlled by a density-dependent mechanism that is important for the parasite's infection dynamics, immune evasion via ordered antigenic variation, and disease transmissibility. However, stumpy formation has been lost in most laboratory-adapted trypanosome lines, generating monomorphic parasites that proliferate uncontrolled as slender forms in vitro and in vivo. Nonetheless, these forms are readily amenable to cell culture and high-throughput screening for trypanocidal lead compounds. Here, we have developed and exploited a high-throughput screen for developmental phenotypes using a transgenic monomorphic cell line expressing a reporter under the regulation of gene control signals from the stumpy-specific molecule PAD1. Using a whole-cell fluorescence-based assay to screen over 6,000 small molecules from a kinase-focused compound library, small molecules able to activate stumpy-specific gene expression and proliferation arrest were assayed in a rapid assay format. Independent follow-up validation identified one hit able to induce modest, yet specific, changes in mRNA expression indicative of a partial differentiation to stumpy forms in monomorphs. Further, in pleomorphs this compound induced a stumpy-like phenotype, entailing growth arrest, morphological changes, PAD1 expression, and enhanced differentiation to procyclic forms. This not only provides a potential tool compound for the further understanding of stumpy formation but also demonstrates the use of high-throughput screening in the identification of compounds able to induce specific phenotypes, such as differentiation, in African trypanosomes

    Regulation of Trypanosoma brucei Total and Polysomal mRNA during Development within Its Mammalian Host

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    This work was supported by a Wellcome Trust Programme grant to KM and by a Wellcome Trust Strategic award to the Centre for Immunity, Infection and Evolution at the University of Edinburgh. SM was supported by a studentship from the Medical Research Council, UK.The gene expression of Trypanosoma brucei has been examined extensively in the blood of mammalian hosts and in forms found in the midgut of its arthropod vector, the tsetse fly. However, trypanosomes also undergo development within the mammalian bloodstream as they progress from morphologically 'slender forms' to transmissible 'stumpy forms' through morphological intermediates. This transition is temporally progressive within the first wave of parasitaemia such that gene expression can be monitored in relatively pure slender and stumpy populations as well as during the progression between these extremes. The development also represents the progression of cells from translationally active forms adapted for proliferation in the host to translationally quiescent forms, adapted for transmission. We have used metabolic labelling to quantitate translational activity in slender forms, stumpy forms and in forms undergoing early differentiation to procyclic forms in vitro. Thereafter we have examined the cohort of total mRNAs that are enriched throughout development in the mammalian bloodstream (slender, intermediate and stumpy forms), irrespective of strain, revealing those that exhibit consistent developmental regulation rather than sample specific changes. Transcripts that cosediment with polysomes in stumpy forms and slender forms have also been enriched to identify transcripts that escape translational repression prior to transmission. Combined, the expression and polysomal association of transcripts as trypanosomes undergo development in the mammalian bloodstream have been defined, providing a resource for trypanosome researchers. This facilitates the identification of those that undergo developmental regulation in the bloodstream and therefore those likely to have a role in the survival and capacity for transmission of stumpy forms.Publisher PDFPeer reviewe

    Rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART): Study protocol for a randomized controlled trial

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    Background: Acute respiratory distress syndrome (ARDS) is associated with high in-hospital mortality. Alveolar recruitment followed by ventilation at optimal titrated PEEP may reduce ventilator-induced lung injury and improve oxygenation in patients with ARDS, but the effects on mortality and other clinical outcomes remain unknown. This article reports the rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART). Methods/Design: ART is a pragmatic, multicenter, randomized (concealed), controlled trial, which aims to determine if maximum stepwise alveolar recruitment associated with PEEP titration is able to increase 28-day survival in patients with ARDS compared to conventional treatment (ARDSNet strategy). We will enroll adult patients with ARDS of less than 72 h duration. The intervention group will receive an alveolar recruitment maneuver, with stepwise increases of PEEP achieving 45 cmH(2)O and peak pressure of 60 cmH2O, followed by ventilation with optimal PEEP titrated according to the static compliance of the respiratory system. In the control group, mechanical ventilation will follow a conventional protocol (ARDSNet). In both groups, we will use controlled volume mode with low tidal volumes (4 to 6 mL/kg of predicted body weight) and targeting plateau pressure &lt;= 30 cmH2O. The primary outcome is 28-day survival, and the secondary outcomes are: length of ICU stay; length of hospital stay; pneumothorax requiring chest tube during first 7 days; barotrauma during first 7 days; mechanical ventilation-free days from days 1 to 28; ICU, in-hospital, and 6-month survival. ART is an event-guided trial planned to last until 520 events (deaths within 28 days) are observed. These events allow detection of a hazard ratio of 0.75, with 90% power and two-tailed type I error of 5%. All analysis will follow the intention-to-treat principle. Discussion: If the ART strategy with maximum recruitment and PEEP titration improves 28-day survival, this will represent a notable advance to the care of ARDS patients. Conversely, if the ART strategy is similar or inferior to the current evidence-based strategy (ARDSNet), this should also change current practice as many institutions routinely employ recruitment maneuvers and set PEEP levels according to some titration method.Hospital do Coracao (HCor) as part of the Program 'Hospitais de Excelencia a Servico do SUS (PROADI-SUS)'Brazilian Ministry of Healt

    A relação entre pais e professores: uma construção de proximidade para uma escola de sucesso

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    São objectivos do presente trabalho identificar os factores que promovem o envolvimento parental das famílias de nível sócio-económico baixo na escola, e propor estratégias de envolvimento parental junto das escolas e dos professores, especialmente com os que estão a iniciar a sua formação, tendo em vista minorar as dificuldades e os insucessos que as crianças manifestam, e por consequência, evitar o abandono escolar. De forma a avaliar as três das dimensões do envolvimento parental em escolas portuguesas, designadamente, a comunicação entre a escola e a família, o envolvimento da família em actividades na escola, e o envolvimento da família em actividades de aprendizagem em casa, aplicaram-se dois questionários em duas versões distintas, uma para pais e outra para professores, a uma amostra de 591 sujeitos resultante de uma investigação longitudinal integrada, em escolas portuguesas do 1º ciclo. A análise dos resultados permitiu identificar um grupo de 24 famílias de nível sócio-económico baixo, que apresentava, ao contrário do que era esperado, um nível alto de envolvimento parental na escola e em casa. Através da realização de entrevistas a famílias deste grupo, procedeu-se à identificação de factores que estavam associados a um alto envolvimento parental tendo-se apurado como significativos: i) o modelo de proximidade que o professor estabelece com os pais, baseado num conhecimento real de cada aluno e de cada família; ii) a partilha de informação e a forma como a comunicação se processa, o que permite aos pais minimizarem os anseios, as preocupações e dificuldades, bem como, uma participação mais activa na escola, face a um maior apoio pedagógico; e, por último, iii) um acompanhamento mais efectivo das actividades de aprendizagem em casa e nos tempos livres. Paralelamente, de salientar que o bom aproveitamento escolar, associado a expectativas positivas que os pais têm relativamente aos filhos, facilitou e promoveu o envolvimento parental.Foi igualmente possível confirmar que os pais, apesar de continuarem interessados e envolvidos, sentiam que na transição para o 2º ciclo o afastamento acontecia e que a partilha se tornava mais complicada. De facto, foi bem evidente a referência a um número crescente de dificuldades, quer na comunicação com a escola e o professor, quer na compreensão de certas áreas de ensino, decorrentes de uma insuficiente formação académica. Nestas circunstâncias, justifica-se na formação inicial dos educadores e dos professores uma sensibilização e abordagem mais adequadas e vocacionadas para esta temática (principalmente para os do 2º ciclo), dando especial atenção às áreas comunicacionais e pedagógicas,encorajando-os na criação de estratégias criativas que forneçam às famílias condições de apoio em todo o processo educativo, com base nos seus interesses e empenho
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