Browsing by Issue Date, starting with "2005-12"
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- Results of radiation protection programmes on mammographyPublication . Machado, Nuno; Carvoeiras, Pedro; Teixeira, NunoIn this paper, we present the results of mammography quality control tests related to the work with Portuguese mammography equipment, either in conventional or in digital mammography computed radiography, showing the main differences in the tested equipments. Quality control in mammography is a very special area of quality control in radiology, which demands relatively high knowledge on physics. Digital imaging is changing the standards of the radiographic imaging. Regarding mammography, this is yet a controversial issue owing to some limitations of the digital detectors, like the resolution for instance. A complete set of results regarding radiation protection of the patients submitted to mammography diagnosis is presented. A discussion of the quality image parameters and its interpretation in conventional and digital mammography is presented. In conclusion, we present a sample of results that can be considered as characteristics of mammography equipment in Portugal.
- Polyglycine expansions in eRF3/GSPT1 are associated with gastric cancer susceptibilityPublication . Brito, Miguel; Malta-Vacas, Joana; Carmona, Bruno; Aires, C.; Costa, P.; Martins, A. P.; Ramos, S.; Conde, A. R.; Monteiro, C.Gastric cancer remains a major cause of death in the developed countries, and a large percentage is still genetically unexplained. Because of their major role in cell survival, mutations in translation factors and altered expression of these genes have been associated with cancer development. Apart from its role in translation termination, the eukaryotic translation release factor 3 (eRF3) is involved in several critical cellular processes, such as cell cycle regulation, cytoskeleton organization, and apoptosis. The aim of this study was to evaluate eRF3/GSPT1 gene as a potential genetic susceptibility associated locus for gastric cancer, analyzing a stable GGC expansion in exon 1 encoding a polyglycine tract in the N-terminal domain of the protein. DNA was obtained from 139 patients with gastric cancer and from 100 individuals of a healthy control population. The GGC expansion was amplified by PCR and the number of repeats determined by genotyping in an automatic sequencer. There are five known alleles encoding from 8 to 12 glycines. The most common allele encodes 10 glycines. The 12-Gly allele was detected exclusively in the cancer patients (allelic frequency = 5%). Regardless of the genotype, patients with the 12-Gly allele had a 20-fold increased risk for gastric cancer. We also detected a single-base alteration in the gene (G274T) although no correlation with cancer development has been found. Thus, our results show that the GGC expansion may have a potential role in regulating eRF3/GSPT1 expression and/or changing the protein function that can lead to gastric cancer development.
- Panorama da logística 2005Publication . Pereira, Francisco José Costa; Verissimo, JorgeUma vez mais, a revista “Logística Hoje” publica o Panorama da Logística, que representa a continuação de um projecto pioneiro lançado pela nossa publicação. É, pois, com um enorme prazer e satisfação que renovamos esta edição de grande interesse e de referência para todos os profissionais de logística. Consideramos esta iniciativa como uma mais-valia para o sector empresarial, apesar de não apresentar a totalidade dos operadores com actividade em Portugal. No entanto, acreditamos que estamos a dar uma imagem bastante aproximada da actual situação do mercado português da logística. Não podíamos deixar de destacar e agradecer às empresas que responderam aos questionários que lhes foram enviados, dando assim um contributo precioso para que este Panorama se torne, de facto, num documento relevante para o sector logístico. Preparado por uma equipa da Escola Superior de Comunicação Social, com concepção a cargo da Logistema, este Panorama apresenta uma informação detalhada sobre a actualidade e as perspectivas de desenvolvimento futuro da logística empresarial e da macrologística, assim como as mais recentes novidades no que concerne à utilização de equipamentos de armazém, veículos de transporte e tecnologias de informação. O destaque vai, como é óbvio, para a análise da situação dos operadores logísticos e dos transportadores no mercado português. Pretende distinguir as empresas que se dedicam à organização, integração e gestão das actividades necessárias à disponibilização atempada e adequada dos bens nos locais de consumo, usando maioritariamente meios e recursos subcontratados, daquelas que prosseguem os mesmos objectivos utilizando em grande parte meios e recursos próprios, em particular na actividade de transporte. (David Espanca)
- Structural characterization and immunogenicity in wild-type and immune tolerant mice of degraded recombinant human interferon Alpha2bPublication . Hermeling, S.; Caetano, Liliana Aranha; Damen, J. M.; Slijper, M.; Schellekens, H.; Crommelin, D. J.; Jiskoot, W.Purpose: This study was conducted to study the influence of protein structure on the immunogenicity in wild-type and immune tolerant mice of well-characterized degradation products of recombinant human interferon alpha2b (rhIFNα2b). Methods: RhIFNα2b was degraded by metal-catalyzed oxidation (M), cross-linking with glutaraldehyde (G), oxidation with hydrogen peroxide (H), and incubation in a boiling water bath (B). The products were characterized with UV absorption, circular dichroism and fluorescence spectroscopy, gel permeation chromatography, reverse-phase high-pressure liquid chromatography, sodium dodecyl sulfate polyacrylamide gel electrophoresis, Western blotting, and mass spectrometry. The immunogenicity of the products was evaluated in wild-type mice and in transgenic mice immune tolerant for hIFNα2. Serum antibodies were detected by enzyme-linked immunosorbent assay or surface plasmon resonance. Results: M-rhIFNα2b contained covalently aggregated rhIFNα2b with three methionines partly oxidized to methionine sulfoxides. G-rhIFNα2b contained covalent aggregates and did not show changes in secondary structure. H-rhIFNα2b was only chemically changed with four partly oxidized methionines. B-rhIFNα2b was largely unfolded and heavily aggregated. Nontreated (N) rhIFNα2b was immunogenic in the wild-type mice but not in the transgenic mice, showing that the latter were immune tolerant for rhIFNα2b. The anti-rhIFNα2b antibody levels in the wild-type mice depended on the degradation product: M-rhIFNα2b > H-rhIFNα2b ∼ N-rhIFNα2b ≫ B-rhIFNα2b; G-rhIFNα2b did not induce anti-rhIFNα2b antibodies. In the transgenic mice, only M-rhIFNα2b could break the immune tolerance. Conclusions: RhIFNα2b immunogenicity is related to its structural integrity. Moreover, the immunogenicity of aggregated rhIFNα2b depends on the structure and orientation of the constituent protein molecules and/or on the aggregate size.
- Algo sobre a Europa: Thomas MorePublication . Coelho, Rui PinaCrítica de teatro / Thomas More / William Shakespeare / Anthony Munday / Robert Delamere / Royal Shakespeare Company