1,721,014 research outputs found
Avaliação do risco de transmissão de malária por transfusão de sangue na área endêmica brasileira
Full text linkTese (doutorado)—Universidade de Brasília, Faculdade de Medicina, Núcleo de Medicina Tropical, 2014.A malária transmitida por transfusão (MTT) é uma doença grave e subnotificada nos países endêmicos para malária. Avaliou-se o risco da MTT em serviços de hemoterapia (SH) da Região Amazônica brasileira (RAB) por meio da estimativa das prevalências de infecção por Plasmodium e dos seus fatores de risco (FRMal) em candidatos à doação de sangue. Realizou-se uma avaliação normativa de SH da RAB, com enfoque na prevenção da MTT e calculou-se a sensibilidade de um protocolo de nested- PCR aplicado em pool de amostras de sangue total. Métodos: Candidatos à doação de sangue, aptos e inaptos pela triagem clínica (TC) e epidemiológica (TE) de quatro SH, foram investigados quanto à presença de FRMal e tiveram uma amostra de sangue coletada para detecção do parasito. Nested-PCR em pool de cinco amostras foi utilizada para detecção do Plasmodium. As prevalências e intervalos de confiança a 95% (IC95%) foram obtidos dos resultados da nested-PCR (infecção) e do questionário epidemiológico (FRMal). Para avaliação normativa, utilizou-se questionário semiestruturado que e os SH foram classificados em inadequados, parcialmente adequados e adequados. Resultados: A nested-PCR apresentou sensibilidade de 95,2% (IC95%: 76,2% a 99,9%) para detecção de 0,20 parasito/microlitros de sangue. Para o estudo da prevalência e dos FRMal, foram selecionados 2.992 indivíduos (80% aptos e 20% inaptos). A malária foi o principal motivo de inaptidão entre as mulheres, e o segundo entre os homens. Os principais FRMal nos candidatos à doação aptos foram: “moradia/trabalho/estudo em municípios com alto risco para malária” (40,0%: IC95%: 38,0% a 40,2%); “deslocamento para áreas de risco (zona rural/áreas silvestres/garimpos)” (19,3%: IC95%: 17,8% a 21,0%); “duas ou mais malárias na vida” (8,9%: IC95%: 7,8% a 10,1%). Pelos critérios normativos, 42,0% (IC95%: 40,1% a 44,1%) dos aptos relataram FRMal que os tornariam inaptos à doação no dia da entrevista. A prevalência geral de infecção por Plasmodium foi 0,07% (n=2/2.992; IC95%: 0,01% a 0,27%), sendo de 0,04% (IC95%: 0,00% a 0,27%) nos aptos e 0,17% (IC95%: 0,01% a 1,07%) nos inaptos. A mediana geral de pontos entre os SH avaliados na avaliação normativa foi 49,8 (mínimo=16; máximo=78); cinco foram classificados como inadequados e cinco como parcialmente adequados. Conclusões: Nested-PCR em pool de amostras mostrou-se uma alternativa à gota espessa na triagem laboratorial para malária em SH da RAB. A alta prevalência de exposição aos FRMal nos candidatos à doação de sangue alerta para o risco de gerar desabastecimento se, de fato, todos os expostos aos FRMal fossem considerados inaptos. Portanto, é indicada a utilização de testes de alta sensibilidade na triagem laboratorial da malária. A avaliação normativa mostrou que a adesão às normas para a prevenção da MTT é negligenciada pelos SH. Recomenda-se o perfeiçoamento das normas vigentes para reduzir o risco de MTT, com a preocupação em não causar desabastecimento de sangue na RAB. ______________________________________________________________________________ ABSTRACTTransfusion-transmitted malaria (TTM) is a serious, underreported disease in malaria endemic countries. The aim of this thesis was to evaluate the risk of TTM in blood banks (BB) from the Brazilian Amazon Region (BAR) by estimating the prevalence of Plasmodium infection and its risk factors in blood donors as well as conducting a normative evaluation in BB, focusing on prevention of TTM. Blood donors from four BB were surveyed about the presence of risk factors for malaria and had a blood sample collected for parasite detection. Nested-PCR in pool of five samples, previously validated for these conditions, was used for Plasmodium detection. The prevalence and confidence intervals at 95% (95%CI) of Plasmodium infection and risk factors for malaria were obtained, respectively, based on the results of the nested-PCR and epidemiological questionnaire. The normative evaluation was performed in 10 BB from BAR using semi-structured questionnaire. For each item a score was assigned and the final score of each BB enable us to classify it as inadequate, partially adequate and adequate. The nested-PCR presented a sensitivity of 95.2% (95% CI: 76.2% to 99.9%) for detection of 0.20 parasites/microliter of blood. We surveyed 2,992 individuals, 80% qualified and 20% deferred for donation after the BB clinical and epidemiological screening, to assess the prevalence and risk factors for malaria. Malaria was the main deferring cause among women, and the second among men after BB clinical and epidemiological screening. The main risk factors among qualified donors were housing, work or study in municipalities with high risk for malaria (40.0%: 95%CI: 38.0% to 40.2%) and visiting risk areas (rural, wild areas and mines) (19.3%: 95%CI: 17.8% to 21.0%). In addition, 8.9% (95%CI: 7.8% to 10.1%) reported two or more episodes of malaria in their life. According to the regulations, 42.0% (95%CI: 40.1% to 44.1%) of qualified donors had one or more deferrable risk factors for donation. The overall prevalence of Plasmodium infection was 0.07% (n=2/2.992, 95%CI: 0.01% to 0.27%) and 0.04% (95%CI: 0.00% to 0.27%) among qualified donors and 0.17% (95%CI: 0.01% to 1.07%) among deferred donors. About normative evaluation, the overall median score was 49.8 (min=16, max=78) Five BB were classified as "inadequate" and five as "partially adequate". Nested-PCR in pooled samples proved to be an option to the thick blood smear for malaria laboratory screening in BB from BAR. The high prevalence of exposure to risk factors for malaria in blood donors highlights the risk of lack of blood supply if all exposed donors were deferred. Therefore, high-sensitivity tests are necessary for malaria laboratory screening. Normative evaluation showed that adherence to standards for the prevention of TTM is neglected by BB because none achieved "adequate" rating. We recommended improvement of current regulations to reduce the risk of TTM, keeping in mind the concerning about lack of blood supply in the BAR.Faculdade de Medicina (FM)Programa de Pós-Graduação em Medicina Tropica
Associação entre a produção anual de ouro em garimpos e incidência de malária em Mato Grosso - Brasil, 1985-1996
No full textBaseado em dados secundários realizou-se análise epidemiológica do tipo ecológico da série histórica da incidência parasitária anual da malária, produção oficial anual garimpeira de ouro e gastos financeiros do Programa de Controle da Malária na Bacia Amazônica relativo ao Estado de Mato Grosso, no período de 1985-1996. Associação positiva e estatisticamente significante (p<0,001) entre produção de ouro e IPA foi observada em análise multivariada, ainda que controlada por gastos financeiros. Esse achado contribui para a elucidação da tendência de redução da malária em MT, observada na última década
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Internal validity of clinical trials for Plasmodium vivax malaria treatment
Full text linkResistência parasitária pode ser definida como a habilidade da cepa parasitária de sobreviver e/ou multiplicar, a despeito da administração e absorção da medicação dada em doses iguais ou superiores àquelas usualmente recomendadas, porém dentro do limite de tolerância dos indivíduos. Assim sendo, o desenho de estudo ideal para monitorizar a emergência da resistência parasitária aos antimaláricos deveria utilizar controles históricos ou alguma informação prévia (baseline) válida. Além disso, é fundamental que se tenha algum tipo de controle sobre os demais determinantes de falha terapêutica, não diretamente relacionados ao fenômeno biológico da resistência do parasita, os quais poderiam variar através do tempo e teriam potencial de distorcer a interpretação dos resultados de estudos dessa natureza. No presente artigo são feitas considerações sobre a validade interna de estudos que objetivam avaliar a emergência da resistência in vivo do Plasmodium vivax à doses padronizadas de primaquina usadas rotineiramente pelos serviços de saúde. Poucos foram os estudos que atentaram para a necessidade de controlar os determinantes externos da falha terapêutica, ou que se preocuparam em comparar os resultados encontrados com as taxas de cura historicamente observadas em uma dada região geográfica. Assim, recomenda-se que maior ênfase seja dada à validade interna (e limitações) das conclusões de estudos dessa natureza. _______________________________________________________________________________________ ABSTRACTParasite resistance can be defined as the ability of a parasite strain to survive and/or to multiply despite the administration and absorption of a drug given in doses equal or higher than those usually recommended, but within the limits of tolerance of the patients. Therefore, the ideal study design to be used to monitor emergence of parasite resistance would use historical controls or any valid baseline data. Moreover, it is desirable to have some control of remaining determinants of therapeutic failure, not related to biological parasite resistance, which could vary over time and would have potential to distort the analysis for detecting emergence of parasite resistance. Here we comment on the internal validity of studies, which aim to assess the in vivo Plasmodium vivax emergence of resistance to standard doses of primaquine used routinely by health services. Few studies have paid attention to the need to control for other determinant factors of therapeutic failures or made any attempt to compare current findings with cure failure rates of historical controls from a given geographical area. Therefore, attention to the internal validity (and limitations) of study conclusions in these types of study is strongly advised.Faculdade de Medicina (FM
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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