248 research outputs found
Affinity study of novel gelatin cell carriers for fibronectin
In the present work, the gelatin/fibronectin affinity was evaluated using SPR, QCM and radiolabelling. The results indicate that type A gelatin films possess a higher affinity for Fn compared to type B gelatin. This is due to a combined hydrophobic and electrostatic interaction between gelatin type A and Fn. In a second part, the affinity of Fn for porous gelatin scaffolds was evaluated. The scaffolds were prepared by a cryogenic treatment and subsequent freeze-drying yielding type I and type II scaffolds which possess different pore geometries/sizes. The results indicate that the Fn density on the scaffolds can be fine-tuned by varying the Fn concentration, the gelatin type (A vs. 13), the pore size/geometry (type I vs. type II scaffolds)
Faecal leukocyte esterase activity is an alternative biomarker in inflammatory bowel disease
Background: Leukocyte cytosolic proteins (e.g., calprotectin) are emerging biomarkers for inflammatory bowel disease. Leukocyte aryl esterase activity has been commonly used for sensitive detection of leukocytes in human body fluids such as urine. Urine test strip results are generally reported in categories. As automated strip readers allow quantitative data to be reported, sensitive quantitative detection of leukocytes in body fluids has become possible. Here, we explored the use of leukocyte esterase as a potential alternative faecal biomarker for inflammatory bowel disease.
Methods: We evaluated leukocyte esterase activity in faecal extracts and compared Cobas u 411 (Roche) quantitative reflectance data with calprotectin concentration for 107 routine samples. Stability of leukocyte esterase for trypsin digestion was carried out by adding trypsin to the extract. Incubation occurred at 37 ° C for 24 h or 48 h.
Results: Reproducibility of the reflectance signal was good (within-run imprecision: 6.1%; between-run imprecision: 6.2%). Results were linear in the range 10 3 – 10 6 WBC/100 mg faeces. The lower limit of detection was 4 WBC/ μ L and the lower limit of quantification was 5 WBC/ μ L. Stability of LE activity in stool and faecal matrix was good. An adequate correlation was obtained between leukocyte esterase activity and the faecal calprotectin concentration: log(y) = 4.28 + 0.29log(x). In vitro experiments monitored the digestion of leukocyte esterase and faecal calprotectin. Leukocyte esterase activity was significantly less affected by trypsin activity than calprotectin immunoreactivity.
Conclusions: Quantitative leukocyte esterase activity of faecal extracts provides information about the leukocyte count in the gut lumen. Leukocyte esterase is a promising and affordable alternative biomarker for monitoring inflammatory bowel disease
Modernist High-Rises in Postwar Antwerp. Two Answers to the same Question
As recent international scholarship has shown, the Modern Movement was not as coherent as authors such as Sigfried Giedion or Nikolaus Pevsner have claimed. Post-war modernism in particular has many faces. Although architects produced similar housing typologies that are presented in collective works of social housing within the same category, the architects could still take different positions. By means of a comparative analysis of two radical modernist high-rise housing projects in Antwerp, this article demonstrates how the focus of the design of similar projects could still differ considerably. Designed by Renaat Braem, the Kiel housing estate (1953) in the south of Antwerp will be compared with Hugo Van Kuyck’s Luchtbal housing estate (1954-1962) in the city’s north. Although both complexes are social housing blocks raised on pilotis, they differ in size, concept, architectural quality and degree of detailing, but also in ideology and utopian content. Both architects shared a fascination for Le Corbusier’s Ville Radieuse and for the Athens Charter (1933), and held a belief in progress and the need for a new idiom. At the same time, however, they have different ways of dealing with modernity. I will employ the analytical framework developed by architectural historian Sarah Williams Goldhagen (2000) to shed light on the architects’ different positions on the social and political axes.Como se processava o debate disciplinar sobre a cidade, que informava a grande expansão urbana em Portugal, antes e depois da revolução de Abril de 1974? De que modo se discutiam a arquitectura e o espaço urbano, quando a falta de habitação era um problema premente, e na Europa se questionava já a cidade produzida no pós guerra? As questões expostas estabelecem o quadro de desenvolvimento de uma pesquisa realizada a partir das duas publicações especializadas de grande divulgação no país na época abordada, as revistas Arquitectura e Binário, incidindo sobre o modo como se processavam o debate, a teorização e a exposição de ideias, que neste texto é sinteticamente apresentada. A temática abordada é entendida como relevante pela sua relação com a prática da transformação da cidade portuguesa, mais do que pela definição de um corpo coerente ou estruturado de ideias, pela organização de diferentes linhas de pensamento ou pela inovação das abordagens. Importa por isso entender o que e como se debatia ou se apresentavam ideias, isto é, como se definia o contexto no qual se desenvolvia o projecto, se desenhava o espaço urbano e o edifício. O momento novo do pós-revolução, em particular, em que toda a organização da sociedade era questionada e todas as possibilidades pareciam em aberto, inteiras e limpas, constituía um recomeço também para os arquitectos, empenhados em criar o suporte físico para a nova época e a nova sociedade. As reflexões, ideias, modelos ou teorias de que se socorriam para fundamentar o desenho, ante a urgência do momento e a premência de resposta ditadas pelo espírito do tempo, tinham já que estar formadas, sendo, em parte, fruto do contexto de discussão disciplinar aqui abordado
Post-WWII Modernism with a glaze: A comparison between Antwerp and Lisbon
Post World War II European modern housing often exhibited a Corbusian influence, but Le Corbusier was not embraced to the same extent everywhere, as noticed during exchanges between the University of Lisbon and the University of Antwerp in the ambit of the COST-Action 18137 on MCMH. While Belgium has several 1950s social housing projects, strongly indebted in its Unité d’habitation in Marseilles, Portugal does not. There, social housing architecture remained rather conservative, even though Corbusian features manifested themselves in some middle-class mass housing projects, such as the complex on Avenida Estados Unidos da América in Lisbon (1954-1966) designed by Lucínio Cruz, Alberto Ayres de Sousa and Mário Oliveira. While the housing blocks are on pilotis, they also have notable Art-Deco elements. In Belgium, free-standing modernist housing on pilotis with Art-Deco features also appears, such as the housing project at the Jan De Voslei in Antwerp designed by Jos Smolderen (1952-1967). These Modernist/Art-Deco hybrids have never been explored in depth because they are considered not radical enough. However, these cases shed light on how (older) architects mediated between traditional architecture and Modernism, between their own preferences and those of the state or housing company. They illuminate the political, social, and urban context in which these buildings were created. This paper explains why the principles Belgian architects applied to social housing were closer to Lisbon’s middle-class housing than their similar buildings for low-income housing. Based on cross-referencing archival material, legislation, on-site observations, and a study of the political, urban and social context, this paper posits a re-reading of Le Corbusier’s legacy in middle-class housing in Lisbon versus Antwerp
Vaginal distribution and retention of a multiparticulate drug delivery system, assessed by gamma scintigraphy and magnetic resonance imaging
How grass keeps growing : an integrated analysis of hormonal crosstalk in the maize leaf growth zone
We studied the maize leaf to understand how long-distance signals, auxin and cytokinin, control leaf growth dynamics. We constructed a mathematical model describing the transport of these hormones along the leaf growth zone and their interaction with the local gibberellin (GA) metabolism in the control of cell division. Assuming gradually declining auxin and cytokinin supply at the leaf base, the model generated spatiotemporal hormone distribution and growth patterns that matched experimental data. At the cellular level, the model predicted a basal leaf growth as a result of cell division driven by auxin and cytokinin. Superimposed on this, GA synthesis regulated growth through the control of the size of the region of active cell division. The predicted hormone and cell length distributions closely matched experimental data. To correctly predict the leaf growth profiles and final organ size of lines with reduced or elevated GA production, the model required a signal proportional to the size of the emerged part of the leaf that inhibited the basal leaf growth driven by auxin and cytokinin. Excision and shading of the emerged part of the growing leaf allowed us to demonstrate that this signal exists and depends on the perception of light intensity
Minimal processing of iceberg lettuce has no substantial influence on the survival, attachment and internalization of E. coli O157 and Salmonella
Effects of plant stanol ester consumption on fasting plasma oxy(phyto) sterol concentrations as related to fecal microbiota characteristics
Information regarding dietary effects on plasma oxyphytosterol concentrations as well as on the origin of oxyphytosterols is scarce. We hypothesized that plant sterols are oxidized in the intestinal lumen, mediated by microbial activity, followed by uptake into the circulation. To address this hypothesis, we carried out, a randomized, double blind, crossover study in 13 healthy subjects, who consumed for 3 weeks control and plant stanol ester enriched margarines (3.0 g/d plant stanols) separated by a 4-week wash-out period. Plasma oxy(phyto)sterols were determined via GC-MS/MS, while microbiota analyses were performed on fecal DNA using a phylogenetic microarray to assess microbial composition and diversity. Plasma plant sterol concentrations did not correlate with plasma oxyphytosterols concentrations at baseline. Plant stanol consumption reduced serum sitosterol and campesterol concentrations (-37% and -38%), respectively (p <0.001), as well as plasma concentrations of 7 beta-OH-campesterol (-24%; p <0.05), 7 beta-OH-sitosterol (-17%; p <0.05) and 7-keto-sitosterol (-13%; p <0.05). Although the intestinal microbiota composition and diversity of the faecal contents were not different between the two periods, we observed significant correlations between several specific bacterial groups and plasma plant sterol, but not with plasma oxyphytosterol concentrations. In conclusion, plant stanol ester consumption reduced serum plant sterol and plasma oxyphytosterol concentrations, while intestinal microbiota composition and diversity were not changed. To definitely answer the effects of microbiota on oxyphytosterol formation, future studies could examine oxyphytosterol concentrations after changing intestinal microbial composition or by measuring intestinal oxyphytosterol formation after providing labelled non-oxidized plant sterols. (C) 2016 Elsevier Ltd. All rights reserved.Peer reviewe
Development of a qPCR platform for quantification of the five bacteriophages within bacteriophage cocktail 2 (BFC2)
To determine phage titers accurately, reproducibly and in a non-laborious and cost-effective manner, we describe the development of a qPCR platform for molecular quantification of five phages present in bacteriophage cocktail 2 (BFC2). We compared the performance of this molecular approach, with regard to quantification and reproducibility, with the standard culture-based double agar overlay method (DAO). We demonstrated that quantification of each of the five phages in BFC2 was possible by means of qPCR, without prior DNA extraction, but yields were significantly higher in comparison to DAO. Although DAO is assumed to provide an indication of the number of infective phage particles, whereas qPCR only provides information on the number of phage genomes, the difference in yield (qPCR/DAO ratio) was observed to be phage-dependent and appeared rather constant for all phages when analyzing different (freshly prepared) stocks of these phages. While DAO is necessary to determine sensitivity of clinical strains against phages in clinical applications, qPCR might be a valid alternative for rapid and reproducible quantification of freshly prepared stocks, after initial establishment of a correction factor towards DAO
Evaluation of the Stability of Bacteriophages in Different Solutions Suitable for the Production of Magistral Preparations in Belgium
In Belgium, the incorporation of phages into magistral preparations for human application has been permitted since 2018. The stability of such preparations is of high importance to guarantee quality and efficacy throughout treatments. We evaluated the ability to preserve infectivity of four different phages active against three different bacterial species in five different buffer and infusion solutions commonly used in medicine and biotechnological manufacturing processes, at two different concentrations (9 and 7 log pfu/mL), stored at 4 °C. DPBS without Ca2+ and Mg2+ was found to be the best option, compared to the other solutions. Suspensions with phage concentrations of 7 log pfu/mL were unsuited as their activity dropped below the effective therapeutic dose (6-9 log pfu/mL), even after one week of storage at 4 °C. Strong variability between phages was observed, with Acinetobacter baumannii phage Acibel004 being stable in four out of five different solutions. We also studied the long term storage of lyophilized staphylococcal phage ISP, and found that the titer could be preserved during a period of almost 8 years when sucrose and trehalose were used as stabilizers. After rehydration of the lyophilized ISP phage in saline, the phage solutions remained stable at 4 °C during a period of 126 days
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