459 research outputs found

    Prostatectomia radical laparoscópica versus aberta: margens cirúrgicas

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    A prostatectomia radical por via laparoscópica é atualmente uma via de abordagem al- ternativa à via clássica. Objetivos: Pretende-se comparar os resultados oncológicos, nomeadamente as margens cirúrgicas, dos dois tipos de abordagens. Material e métodos: Em Setembro de 2012 deu-se início, a um estudo prospetivo durante 10 meses, com o objetivo de comparar os resultados da prostatectomia radical laparos- cópica versus aberta. Incluiu-se no estudo apenas os tumores de baixo risco e de risco intermédio. Avaliou-se diversos parâmetros: idade, PSA inicial, Gleason na biópsia, duração da ci- rurgia, número de transfusões sanguíneas, margens cirúrgicas, complicações, Gleason e estádio TNM na peça operatória. Resultados: Foram incluídos no estudo 45 doentes, 24 operados por via laparoscópica e 21 por via aberta. No grupo da abordagem laparoscópica, dos 24 doentes 70,8% (17) apresentaram margens negativas, 25% (6) margens positivas e 4,17% (1) não avaliável. No grupo da abordagem aberta dos 21 doentes 66,7% (14) apresentaram margens nega- tivas, 28,6% (6) margens positivas e 4,76% (1) não avaliável. A aplicação de um teste do qui-quadrado considerando dois grupos de margens: po- sitivas e não positivas, resultou num valor observado do qui-quadrado igual a 0,07 (p valor = 0,79), pelo que se concluiu não haver diferenças signifi cativas na distribuição das margens positivas nos dois grupos de abordagem cirúrgica. Procurámos avaliar se a distribuição dos tumores classifi cados como T2a, T2b, T2c, T3a e T3b, era idêntica nos dois grupos. Obtivemos um valor observado para o qui-quadrado de 1,44 (p valor = 0,23), que nos permitiu concluir que a distribuição dos dois grupos de estádios tumorais não é signifi cativamente diferente nos dois tipos de cirurgia utilizados. Conclusões: Os resultados obtidos neste estudo revelam que não há associação entre as margens e o tipo de abordagem cirúrgica bem como, não existe também associação entre os estádios tumorais e os dois tipos de abordagem cirúrgica. Através das diferentes análises elaboradas neste estudo podemos concluir que a pros- tatectomia radical laparoscópica poderá ser uma alternativa válida à abordagem aberta nos tumores de baixo risco e de risco intermédio. Apesar do número reduzido de casos, pensamos que é uma técnica segura do ponto de vista oncológico, não estando reservada apenas a centros de alto volume

    Having a pair: the key to immune evasion for the diploid pathogen Schistosoma japonicum

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    Schistosomes, unlike malaria parasites, are in their diploid stage when targeted by the human immune system. Diploids can be either homozygous or heterozygous. The difference has profound significance for developing immunity and yet has not previously been addressed. We examined the implications of zygosity on immunity to a diploid pathogen, Schistosoma japonicum and showed that the diploid state, and its associated heterozygous advantage, significantly affects the outcome of attack by the immune system and the accumulation of antigenic diversity in the parasite population. We demonstrate here that diploidy provides a novel means of immune evasion for diploid pathogens

    A Standardised Procedure for Evaluating Creative Systems: Computational Creativity Evaluation Based on What it is to be Creative

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    Computational creativity is a flourishing research area, with a variety of creative systems being produced and developed. Creativity evaluation has not kept pace with system development with an evident lack of systematic evaluation of the creativity of these systems in the literature. This is partially due to difficulties in defining what it means for a computer to be creative; indeed, there is no consensus on this for human creativity, let alone its computational equivalent. This paper proposes a Standardised Procedure for Evaluating Creative Systems (SPECS). SPECS is a three-step process: stating what it means for a particular computational system to be creative, deriving and performing tests based on these statements. To assist this process, the paper offers a collection of key components of creativity, identified empirically from discussions of human and computational creativity. Using this approach, the SPECS methodology is demonstrated through a comparative case study evaluating computational creativity systems that improvise music

    Biochemical comparison of two Hypostomus populations (Siluriformes, Loricariidae) from the Atlântico Stream of the upper Paraná River basin, Brazil

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    Two syntopic morphotypes of the genus Hypostomus - H. nigromaculatus and H. cf. nigromaculatus (Atlântico Stream, Paraná State) - were compared through the allozyme electrophoresis technique. Twelve enzymatic systems (AAT, ADH, EST, GCDH, G3PDH, GPI, IDH, LDH, MDH, ME, PGM and SOD) were analyzed, attributing the score of 20 loci, with a total of 30 alleles. Six loci were diagnostic (Aat-2, Gcdh-1, Gpi-A, Idh-1, Ldh-A and Mdh-A), indicating the presence of interjacent reproductive isolation. The occurrence of few polymorphic loci acknowledge two morphotypes, with heterozygosity values He = 0.0291 for H. nigromaculatus and He = 0.0346 for H. cf. nigromaculatus. FIS statistics demonstrated fixation of the alleles in the two morphotypes. Genetic identity (I) and distance (D) of Nei (1978) values were I = 0.6515 and D = 0.4285. The data indicate that these two morphotypes from the Atlântico Stream belong to different species

    Enzymatic Shaving of the Tegument Surface of Live Schistosomes for Proteomic Analysis: A Rational Approach to Select Vaccine Candidates

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    Adult schistosome parasites can reside in the host bloodstream for decades surrounded by components of the immune system. It was originally proposed that their survival depended on the secretion of an inert bilayer, the membranocalyx, to protect the underlying plasma membrane from attack. We have investigated whether any proteins were exposed on the surface of live worms using incubation with selected hydrolases, in combination with mass spectrometry to identify released proteins. We show that a small number of parasite proteins are accessible to the enzymes and so could represent constituents of the membranocalyx. We also identified several proteins acquired by the parasite on contact with host cells. In addition, components of the cytolytic complement pathway were detected, but these appeared not to harm the worm, indicating that some of its own surface proteins could inhibit the lytic pathway. We suggest that, collectively, the ‘superficial’ parasite proteins may provide good candidates for a schistosome vaccine
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