Evidence for a nuclear compartment of transcription and splicing located at chromosome domain boundaries

The nuclear topography of splicing snRNPs, mRNA transcripts and chromosome domains in various mammalian cell types are described. The visualization of splicing snRNPs, defined by the Sm antigen, and coiled bodies, revealed distinctly different distribution patterns in these cell types. Heat shock experiments confirmed that the distribution patterns also depend on physiological parameters. Using a combination of fluorescencein situ hybridization and immunodetection protocols, individual chromosome domains were visualized simultaneously with the Sm antigen or the transcript of an integrated human papilloma virus genome. Three-dimensional analysis of fluorescence-stained target regions was performed by confocal laser scanning microscopy. RNA transcripts and components of the splicing machinery were found to be generally excluded from the interior of the territories occupied by the individual chromosomes. Based on these findings we present a model for the functional compartmentalization of the cell nucleus. According to this model the space between chromosome domains, including the surface areas of these domains, defines a three-dimensional network-like compartment, termed the interchromosome domain (ICD) compartment, in which transcription and splicing of mRNA occurs

Adverse childhood experiences and suicide attempts in morbidly obese adults

Introdução: As tentativas de suicídio surgem frequentemente associadas a problemas alimentares, tanto anorexia quanto bulimia. Do mesmo modo, tem-se verifi cado uma elevada ocorrência de suicídio entre obesos. Investigações têm mostrado que a adversidade na infância pode ser um fator de risco para as tentativas de suicídio. Objetivos: Caracterizar e compreender a relação entre experiências de adversidade na infância e tentativas de suicídio em 100 obesos mórbidos candidatos a cirurgia bariátrica. Métodos: Um total de 100 pacientes foram selecionados de setembro de 2007 a outubro de 2007 e de janeiro de 2008 a janeiro de 2009, sendo que 20 pacientes eram do sexo feminino. A média de idade era de 38,89±9,87 anos, e a média do peso máximo era de 136,43±14 kg. O Questionário da História de Adversidade na Infância foi utilizado para avaliar experiências adversas. Resultados: 88% dos pacientes relataram a existência de pelo menos uma experiência de adversidade na infância, e 25% relataram já ter realizado pelo menos uma tentativa de suicídio. A adversidade na infância esteve associada a um risco aumentado para realizar tentativas de suicídio (odds ratio = 2,026). Conclusão: Esses dados devem ser levados em consideração na avaliação e no acompanhamento desses pacientes.Introduction: Suicide attempts are often associated with eating disorders, both anorexia and bulimia. Likewise, a high incidence of suicide has been observed among obese patients. Previous studies have shown that adverse experiences in childhood may be a risk factor for suicide attempts. Objectives: To characterize and to understand the relationship between adverse experiences and suicide attempts in 100 morbidly obese patients referred for bariatric surgery. Methods: A total of 100 patients were selected from September 2007 to October 2007 and from January 2008 to January 2009. Of these, 20 patients were females. Mean age was 38.89±9.87 years, and mean maximum weight was 136.43±14 kg. The Portuguese version of the Family ACE (Adverse Childhood Experiences) Questionnaire was used to assess the occurrence of adverse events. Results: 88% of the patients reported the existence of at least one adverse experience in childhood, and 25% reported at least one previous suicide attempt. Adversity in childhood was associated with an increased risk for suicide attempts (odds ratio = 2.026). Conclusion: These data should be taken into account in the assessment and monitoring of these patients.Fundação para a Ciência e a Tecnologia (FCT); (SFRH/BD/37069/2007)

The N-P-K soil nutrient balance of portuguese cropland in the 1950s: the transition from organic to chemical fertilization

Agricultural nutrient balances have been receiving increasing attention in both historical and nutrient management research. The main objectives of this study were to further develop balance methodologies and to carry out a comprehensive assessment of the functioning and nutrient cycling of 1950s agroecosystems in Portugal. Additionally, the main implications for the history of agriculture in Portugal were discussed from the standpoint of soil fertility. We used a mass balance approach that comprises virtually all nitrogen (N), phosphorus (P) and potassium (K) inputs and outputs from cropland topsoil for average conditions in the period 1951–56. We found a consistent deficit in N, both for nationwide (−2.1 kg.ha−1.yr−1) and arable crops (−1.6 kg.ha−1.yr−1) estimates, that was rectified in the turn to the 1960 decade. P and K were, in contrast, accumulating in the soil (4.2–4.6 kg.ha−1.yr−1 and 1.0–3.0 kg.ha−1.yr−1, respectively). We observed that the 1950s is the very moment of inflection from an agriculture fertilized predominantly through reused N in biomass (livestock excretions plus marine, plant and human waste sources) to one where chemical fertilizers prevailed. It is suggested that N deficiency played an important role in this transitioninfo:eu-repo/semantics/publishedVersio