576 research outputs found

    Genetic relatedness of Plasmodium falciparum isolates and the origin of allelic diversity at the merozoite surface protein-1 (MSP-1) locus in Brazil and Vietnam

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    BACKGROUND: Despite the extensive polymorphism at the merozoite surface protein-1 (MSP-1) locus of Plasmodium falciparum, that encodes a major repetitive malaria vaccine candidate antigen, identical and nearly identical alleles frequently occur in sympatric parasites. Here we used microsatellite haplotyping to estimate the genetic distance between isolates carrying identical and nearly identical MSP-1 alleles. METHODS: We analyzed 28 isolates from hypoendemic areas in north-western Brazil, collected between 1985 and 1998, and 23 isolates obtained in mesoendemic southern Vietnam in 1996. MSP-1 alleles were characterized by combining PCR typing with allele-specific primers and partial DNA sequencing. The following single-copy microsatellite markers were typed : Polyα, TA42 (only for Brazilian samples), TA81, TA1, TA87, TA109 (only for Brazilian samples), 2490, ARAII, PfG377, PfPK2, and TA60. RESULTS: The low pair-wise average genetic distance between microsatellite haplotypes of isolates sharing identical MSP-1 alleles indicates that epidemic propagation of discrete parasite clones originated most identical MSP-1 alleles in parasite populations from Brazil and Vietnam. At least one epidemic clone propagating in Brazil remained relatively unchanged over more than one decade. Moreover, we found no evidence that rearrangements of MSP-1 repeats, putatively created by mitotic recombination events, generated new alleles within clonal lineages of parasites in either country. CONCLUSION: Identical MSP-1 alleles originated from co-ancestry in both populations, whereas nearly identical MSP-1 alleles have probably appeared independently in unrelated parasite lineages

    Differential effects of antigens from L. braziliensis isolates from disseminated and cutaneous leishmaniasis on in vitro cytokine production

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    BACKGROUND: Disseminated leishmaniasis is an emerging infectious disease, mostly due to L. braziliensis, which has clinical and histopathological features distinct from cutaneous leishmaniasis. METHODS: In the current study we evaluated the in vitro production of the cytokines IFN-γ, TNF-α, IL-5 and IL-10 by peripheral blood mononuclear cells (PBMC) from 15 disseminated leishmaniasis and 24 cutaneous leishmaniasis patients upon stimulation with L. braziliensis antigens genotyped as disseminated leishmaniasis or cutaneous leishmaniasis isolates. RESULTS: Regardless of the source of L. braziliensis antigens, PBMC from cutaneous leishmaniasis patients produced significantly higher IFN-γ than PBMC from disseminated leishmaniasis patients. Levels of TNF-α by PBMC from cutaneous leishmaniasis patients were significantly higher than disseminated leishmaniasis patients only when stimulated by genotyped cutaneous leishmaniasis antigens. The levels of IL-5 and IL-10 production by PBMC were very low and similar in PBMCs from both disseminated leishmaniasis and cutaneous leishmaniasis patients. The immune response of each patient evaluated by the two L. braziliensis antigens was assessed in a paired analysis in which we showed that L. braziliensis genotyped as disseminated leishmaniasis isolate was more potent than L. braziliensis genotyped as cutaneous leishmaniasis isolate in triggering IFN-γ and TNF-α production in both diseases and IL-5 only in cutaneous leishmaniasis patients. CONCLUSION: This study provides evidence that antigens prepared from genotypically distinct strains of L. braziliensis induce different degrees of immune response. It also indicates that both parasite and host play a role in the outcome of L. braziliensis infection

    Performance of organically grown tomato cultivars under greenhouse conditions

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    A agricultura orgânica no Brasil cresce a taxas superiores a 30% ao ano, devido principalmente à maior conscientização dos consumidores que buscam alimentos saudáveis, livres de resíduos químicos e biológicos. Dentre as hortaliças cultivadas em sistema orgânico, o tomate constitui grande desafio para os produtores devido à inexistência de recomendações de manejo cultural e de cultivares desenvolvidas específicas para esse sistema de cultivo. Diante disso, o presente trabalho teve como objetivo avaliar o desempenho de cultivares de tomate sob sistema orgânico, em ambiente protegido. O experimento foi conduzido de maio a outubro de 2004 em campo, no município de Araraquara-SP. O delineamento experimental adotado foi blocos ao acaso, com quatro repetições e oito tratamentos (cultivares Avalon, Colibri, HTX-5415, HTX-8027, Sahel, San Marzano, San Vito e Jane). As plantas foram conduzidas em fileiras duplas, com duas hastes por planta no espaçamento de 0,8 m entre linhas e 0,6 m entre plantas (cerca de 20.000 plantas ha-1), sem poda apical. O híbrido Sahel destacou-se com o melhor desempenho para rendimento comercial. A traça-do-tomateiro se revelou como fator limitante à produção de tomate em sistema orgânico, sendo responsável, em média, por 17% de danos nos frutos colhidos das oito cultivares que foram avaliadas.Organic agriculture in Brazil has been increasing about 30% per year over the last few years, since consumers are seeking for healthier foods, i.e. nutritious and free of pesticide residues. Among organically grown vegetable crops, tomato is an attractive economic opportunity for growers. However, the lack of information about management practices and adapted cultivars to organic production systems under protected cultivation are pointed out as important constraints that prevents this activity to expand. This work aimed at evaluating the performance of indeterminate tomato cultivars in organic management systems in unheated plastic greenhouse. In both experiments tomato plants were staked. Plant spacing was 1.5 m between rows and 0.35 m between plants. They were planted in double line and spaced 0.8 m between lines and 0.6 m between plants (about 20,000 plants ha-1). The experiment was set up in a randomized complete block design, with four replications and eight treatments (cultivars: Avalon, Colibri, HTX-5415, HTX-8027, Sahel, San Marzano, San Vito, and Jane). Sahel hybrid exhibited an outstanding performance for marketable yield under organic cultivation. Tomato pinworm (Tuta absoluta) was a serious limiting pest for organically grown tomatoes, responding for 17% of damage in the fruits harvested from the evaluated cultivars

    Oficina de compras públicas de inovação: América Latina e aprendizados para o Brasil: 5ª Semana de Inovação

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    São relatados problemas e as soluções alternativas para estes. O relatório discorre sobre o hospital de 2050 que deve ser sustentável, verde e eficiente. Outro tema é a capacidade de desenvolvimento científico e tecnológico do Uruguai, e os desafios que se apresentam para a mesma. Também foram abordadas as dificuldades e desafios da inovação, acerca desta temática houveram três oficinas sobre o tema.3 relatórios em pdf com 1 página cadaCompras Públicas. Logística PúblicaInovaçãoA 5ª Semana de Inovação foi realizada de 4 a 7 de novembro de 2019

    Prioritizing WHO normative work on maternal and perinatal health: a multicountry survey

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    <p>Abstract</p> <p>Background</p> <p>WHO develops evidence-based guidelines for setting global standards and providing technical support to its Member States and the international community, as a whole. There is a clear need to ensure that WHO guidance is relevant, rigorous and up-to date. A key activity is to ascertain the guidance needs of the countries. This study provides an international comparison of priority guidance needs for maternal and perinatal health. It incorporates data from those who inform policy and implementation strategies at a national level, in addition to targeting those who use and most need the guidance at grassroot level.</p> <p>Methods</p> <p>An online multi-country survey was used to identify WHO guidance priorities for the next five years in the field of maternal and perinatal health. WHO regional and country offices were requested to respond the survey and obtain responses from Ministries of Health around the world. In addition, the survey was disseminated through other networks and relevant electronic forums.</p> <p>Results</p> <p>A total of 393 responses were received, including 56 from Ministries of Health and 54 from WHO/UN country offices. 75% of responses were from developing countries and 25% from developed countries. Guidance on strategies focusing on 'quality of care' issues to reduce all-cause maternal/perinatal mortality was considered the most important domain to target, which includes for instance guidance to improve access, dissemination, implementation of effective practices and health professionals' education.</p> <p>Conclusions</p> <p>This study provides a panorama of international priority guidance needs for maternal and perinatal health. Although clinical guidance remains a priority, there are other areas related to health systems guidance, which seem to be even more important. Overall, the domain ranked highest in terms of greatest need for guidance was around quality of care, which included questions related to educational needs, access to and implementation of guidance.</p

    Distinct variation in vector competence among nine field populations of Aedes aegypti from a Brazilian dengue-endemic risk city

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    Background: In Brazil, dengue epidemics erupt sporadically throughout the country and it is unclear if outbreaks may initiate a sustainable transmission cycle. There are few studies evaluating the ability of Brazilian Aedes aegypti populations to transmit dengue virus (DENV). The aim of this study was to compare DENV susceptibility of field-captured Ae. aegypti populations from nine distinct geographic areas of the city of Belo Horizonte in 2009 and 2011. Infection Rate (IR), Vector Competence (VC) and Disseminated Infection Rate (DIR) were determined. Methods: Aedes aegypti eggs from each region were collected and reared separately in an insectary. Adult females were experimentally infected with DENV-2 and the virus was detected by qPCR in body and head samples. Data were analyzed with the Statistical Package for the Social Sciences version 17. Results: IR varied from 40.0% to 82.5% in 2009 and 60.0% to 100.0% in 2011. VC ranged from 25.0% to 77.5% in 2009 and 25.0% to 80.0% in 2011. DIR oscillated from 68.7% to 100.0% in 2009 and 38.4% to 86.8 in 2011. When the results were evaluated by a logistic model using IR as covariate, North, Barreiro, South-Central and Venda Nova showed the strongest association in 2009. In 2011, a similar association was observed for South-Central, Venda Nova, West and Northeast regions. Using VC as covariate, South-Central and Venda Nova showed the most relevant association in 2009. In 2011, South-Central, Venda Nova and Barreiro presented the greatest revelation associations. When DIR data were analyzed by logistic regression models, Pampulha, South-Central, Venda Nova, West, Northeast and East (2009) as well as South-Central, Venda Nova and West (2011) were the districts showing the strongest associations. Conclusions: We conclude that Ae. aegypti populations from Belo Horizonte exhibit wide variation in vector competence to transmit dengue. Therefore, vector control strategies should be adapted to the available data for each region. Further analysis should be conducted to better understand the reasons for this large variability in vector competence and how these parameters correlate with epidemiological findings in subsequent years

    Computer simulation of simultaneous evolution of individual texture components During recrystallization of an IF steel

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    Computer simulation of simultaneous evolution of individual texture components during recrystallization of an IF steel is carried out. A new methodology has been developed that takes as its starting point experimental data of each texture component evolving during recrystallization. In particular, Magnusson et al. data on IF steel was analyzed in a previous work with the help of the exact analytical tools developed by Rios and Villa for simultaneous transformations. From this analysis parameters such as number of nuclei of each texture component per unit of volume could be obtained and were employed as input for the present computer simulation. From this input 3-d microstructures could then be generated. The methodology proposed here combines experimental data, exact analytical methods and computer simulation and may be employed to extract the maximum information from the experimental data

    Evaluation of objective and subjective indicators of death in a period of one year in a sample of prevalent patients under regular hemodialysis

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    <p>Abstract</p> <p>Background</p> <p>To identify objective and subjective indicators of death in prevalent hemodialysis (HD) patients in a follow-up study of 12 months.</p> <p>Methods</p> <p>The study included end-stage renal disease patients undergoing HD and analyzed demographic and laboratory data from the dialysis unit's records. Baseline data concerning socioeconomic status, comorbidity, quality of life level, coping style and depression were also assessed. For variables that differed in the comparison between survivors and non-survivors, Cox proportional hazards for death were calculated.</p> <p>Results</p> <p>The mortality rate was 13.0%. Non-survivors differed in age, comorbidity, inclusion on the transplant waiting list and physical functioning score. The hazard ratios of death were 8.958 (2.843-28.223; <it>p </it>< 0.001) for comorbidity, 3.992 (1.462-10.902; <it>p </it>= 0.007) for not being on the transplant waiting list, 1.038 (1.012-1.066; <it>p </it>= 0.005) for age, and 0.980 (0.964-0.996; <it>p </it>= 0.014) for physical functioning.</p> <p>Conclusions</p> <p>Comorbidity, not being on the transplant waiting list, age and physical functioning, which reflects physical status, must be seen as risk indicators of death among patients undergoing HD.</p

    Population Genetics, Evolutionary Genomics, and Genome-Wide Studies of Malaria: A View Across the International Centers of Excellence for Malaria Research.

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    The study of the three protagonists in malaria-the Plasmodium parasite, the Anopheles mosquito, and the human host-is key to developing methods to control and eventually eliminate the disease. Genomic technologies, including the recent development of next-generation sequencing, enable interrogation of this triangle to an unprecedented level of scrutiny, and promise exciting progress toward real-time epidemiology studies and the study of evolutionary adaptation. We discuss the use of genomics by the International Centers of Excellence for Malaria Research, a network of field sites and laboratories in malaria-endemic countries that undertake cutting-edge research, training, and technology transfer in malarious countries of the world
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