139 research outputs found
Diagnosis of Burkitt's lymphoma in due time: a practical approach
Aims: The quick diagnosis of Burkitt's lymphoma (BL) and its clear-cut differentiation from diffuse large B-cell lymphoma (DLBCL) is of great clinical importance since treatment for these two disease entities differ markedly and should promptly be initiated in BL. However, these two tumours are difficult to distinguish using the current WHO classification, particularly in regard to BL variants, i.e., BL with plasmacytoid differentiation and atypical Burkitt's/Burkitt's-like lymphomas. Methods: We studied 39 cases of highly proliferative blastic B-cell lymphoma (HPBCL) to establish a practical differential-diagnostic algorithm. Characteristics set for BL were a typical morphology, a mature B-cell phenotype of CD10+, Bcl-6+ and Bcl-2- tumour cells, a proliferation rate of >95%, and the presence of C-MYC rearrangements in the absence of t(14;18)(q32;q21). All cases were selectively negative for cyclin D-1, CD5, CD23, LMP-EBV, CD34 and TdT, and there were no cases of endemic or immunodeficiency-associated Burkitt's lymphoma. Results: Altogether the set BL characteristics were found in only 5/39 cases (12.8%), whereas the majority of tumours revealed mosaic features (87.2%). In a second attempt, we followed a pragmatic stepwise approach for a classification algorithm that includes the assessment of C-MYC status to stratify HPBCL into four predefined diagnostic categories (DC), namely DC I (5/39, 12.8%): "classical BL", corresponding to the classical variant of sporadic BL in the WHO classification; DC II (11/39, 28.2%): "atypical BL", corresponding to the atypical Burkitt's/Burkitt's-like variants of sporadic BL in the WHO classification; DC III (9/39, 23.1%): "C-MYC+ DLBCL"; and DC IV (14/39, 35.9%): "C-MYC- HPBCL". Conclusion: This proposal may serve as a robust and objective operational basis for therapeutic decisions for HPBCL within one week and is applicable to be evaluated for its prognostic relevance in prospective clinical trials
Novos ângulos da história da agricultura no Brasil.
Este livro tenta resgatar um pouco da história rica, variada e muitas vezes difícil acesso ao aluno de agricultura e de áreas correlatas.Coleção Eliseu Alves: Biblioteca da Embrapa Sede
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Wives’ part-time employment and marital stability in Great Britain, West Germany and the United States
Many hail wives’ part-time employment as a work—family balance strategy, but theories offer competing predictions as to the effects of wives’ employment on relationship stability. We use panel data to test these competing hypotheses among recent cohorts of first-married couples in Great Britain, West Germany 1 and the United States. We find effects of wives’ employment on marital stability var y across the countries. In West Germany with its high-quality part-time employment, couples where the wife works part time are significantly more stable. In the more liberal British and US labour markets, neither wives’ part- nor full-time employment significantly alters divorce risk. In the United States, however, mothers working part time have significantly lower divorce risk. West German and British husbands’ unemployment proves more detrimental to marital stability than wives’ employment. These results highlight the importance of the socioeconomic context in structuring the optimal employment participation of both partners
Reflexivity, knowledge and ecological awareness: premises for responsible action in the hospital work environment
GO4genome: A Prokaryotic Phylogeny Based on Genome Organization
Determining the phylogeny of closely related prokaryotes may fail in an analysis of rRNA or a small set of sequences. Whole-genome phylogeny utilizes the maximally available sample space. For a precise determination of genome similarity, two aspects have to be considered when developing an algorithm of whole-genome phylogeny: (1) gene order conservation is a more precise signal than gene content; and (2) when using sequence similarity, failures in identifying orthologues or the in situ replacement of genes via horizontal gene transfer may give misleading results. GO4genome is a new paradigm, which is based on a detailed analysis of gene function and the location of the respective genes. For characterization of genes, the algorithm uses gene ontology enabling a comparison of function independent of evolutionary relationship. After the identification of locally optimal series of gene functions, their length distribution is utilized to compute a phylogenetic distance. The outcome is a classification of genomes based on metabolic capabilities and their organization. Thus, the impact of effects on genome organization that are not covered by methods of molecular phylogeny can be studied. Genomes of strains belonging to Escherichia coli, Shigella, Streptococcus, Methanosarcina, and Yersinia were analyzed. Differences from the findings of classical methods are discussed
The Bifidobacterium dentium Bd1 Genome Sequence Reflects Its Genetic Adaptation to the Human Oral Cavity
Bifidobacteria, one of the relatively dominant components of the human intestinal microbiota, are considered one of the key groups of beneficial intestinal bacteria (probiotic bacteria). However, in addition to health-promoting taxa, the genus Bifidobacterium also includes Bifidobacterium dentium, an opportunistic cariogenic pathogen. The genetic basis for the ability of B. dentium to survive in the oral cavity and contribute to caries development is not understood. The genome of B. dentium Bd1, a strain isolated from dental caries, was sequenced to completion to uncover a single circular 2,636,368 base pair chromosome with 2,143 predicted open reading frames. Annotation of the genome sequence revealed multiple ways in which B. dentium has adapted to the oral environment through specialized nutrient acquisition, defences against antimicrobials, and gene products that increase fitness and competitiveness within the oral niche. B. dentium Bd1 was shown to metabolize a wide variety of carbohydrates, consistent with genome-based predictions, while colonization and persistence factors implicated in tissue adhesion, acid tolerance, and the metabolism of human saliva-derived compounds were also identified. Global transcriptome analysis demonstrated that many of the genes encoding these predicted traits are highly expressed under relevant physiological conditions. This is the first report to identify, through various genomic approaches, specific genetic adaptations of a Bifidobacterium taxon, Bifidobacterium dentium Bd1, to a lifestyle as a cariogenic microorganism in the oral cavity. In silico analysis and comparative genomic hybridization experiments clearly reveal a high level of genome conservation among various B. dentium strains. The data indicate that the genome of this opportunistic cariogen has evolved through a very limited number of horizontal gene acquisition events, highlighting the narrow boundaries that separate commensals from opportunistic pathogens
NEOTROPICAL XENARTHRANS: a data set of occurrence of xenarthran species in the Neotropics
Xenarthrans – anteaters, sloths, and armadillos – have essential functions for ecosystem maintenance, such as insect control and nutrient cycling, playing key roles as ecosystem engineers. Because of habitat loss and fragmentation, hunting pressure, and conflicts with 24 domestic dogs, these species have been threatened locally, regionally, or even across their full distribution ranges. The Neotropics harbor 21 species of armadillos, ten anteaters, and six sloths. Our dataset includes the families Chlamyphoridae (13), Dasypodidae (7), Myrmecophagidae (3), Bradypodidae (4), and Megalonychidae (2). We have no occurrence data on Dasypus pilosus (Dasypodidae). Regarding Cyclopedidae, until recently, only one species was recognized, but new genetic studies have revealed that the group is represented by seven species. In this data-paper, we compiled a total of 42,528 records of 31 species, represented by occurrence and quantitative data, totaling 24,847 unique georeferenced records. The geographic range is from the south of the USA, Mexico, and Caribbean countries at the northern portion of the Neotropics, to its austral distribution in Argentina, Paraguay, Chile, and Uruguay. Regarding anteaters, Myrmecophaga tridactyla has the most records (n=5,941), and Cyclopes sp. has the fewest (n=240). The armadillo species with the most data is Dasypus novemcinctus (n=11,588), and the least recorded for Calyptophractus retusus (n=33). With regards to sloth species, Bradypus variegatus has the most records (n=962), and Bradypus pygmaeus has the fewest (n=12). Our main objective with Neotropical Xenarthrans is to make occurrence and quantitative data available to facilitate more ecological research, particularly if we integrate the xenarthran data with other datasets of Neotropical Series which will become available very soon (i.e. Neotropical Carnivores, Neotropical Invasive Mammals, and Neotropical Hunters and Dogs). Therefore, studies on trophic cascades, hunting pressure, habitat loss, fragmentation effects, species invasion, and climate change effects will be possible with the Neotropical Xenarthrans dataset
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