An essential thioredoxin-type protein of Trypanosoma brucei acts as redox-regulated mitochondrial chaperone

Most known thioredoxin-type proteins (Trx) participate in redox pathways, using two highly conserved cysteine residues to catalyze thiol-disulfide exchange reactions. Here we demonstrate that the so far unexplored Trx2 from African trypanosomes (Trypanosoma brucei) lacks protein disulfide reductase activity but functions as an effective temperature-activated and redox-regulated chaperone. Immunofluorescence microscopy and fractionated cell lysis revealed that Trx2 is located in the mitochondrion of the parasite. RNA-interference and gene knock-out approaches showed that depletion of Trx2 impairs growth of both mammalian bloodstream and insect stage procyclic parasites. Procyclic cells lacking Trx2 stop proliferation under standard culture conditions at 27°C and are unable to survive prolonged exposure to 37°C, indicating that Trx2 plays a vital role that becomes augmented under heat stress. Moreover, we found that Trx2 contributes to the in vivo infectivity of T. brucei. Remarkably, a Trx2 version, in which all five cysteines were replaced by serine residues, complements for the wildtype protein in conditional knock-out cells and confers parasite infectivity in the mouse model. Characterization of the recombinant protein revealed that Trx2 can coordinate an iron sulfur cluster and is highly sensitive towards spontaneous oxidation. Moreover, we discovered that both wildtype and mutant Trx2 protect other proteins against thermal aggregation and preserve their ability to refold upon return to non-stress conditions. Activation of the chaperone function of Trx2 appears to be triggered by temperature-mediated structural changes and inhibited by oxidative disulfide bond formation. Our studies indicate that Trx2 acts as a novel chaperone in the unique single mitochondrion of T. brucei and reveal a new perspective regarding the physiological function of thioredoxin-type proteins in trypanosomes

Shaping public Opinion for confrontation : catalan independence claims as represented in spanish, catalan, valencian, and basque editorials

Editorials represent a newspaper's principal means of ideological positioning and serve to identify the attitude of each newspaper and its readership to some of the main actors in any given conflict, especially those that are political in nature. Catalonia's independence movement has experienced a surge in recent years. The turning point came in July 2010, after Spain's constitutional court ruled against some aspects of Catalonia's Statute of Autonomy (the legislation regulating the relationship between the Catalan autonomous community and the Spanish state). The ruling annulled some of the articles of the statute. The demonstration in support of Catalan independence that took place on September 11, 2012, was considered the most important among several mass rallies held for this purpose over successive years on Catalonia's National Day. This article presents the results of a qualitative and quantitative analysis of editorial articles published around these two key dates, with the goal of studying each newspaper's treatment of political actors and their degree of identification with these actors. Their use of arguments aimed at persuading readers and legitimizing a given position during the specified time periods in 2010 and 2012 will also be studied. The study focuses on the editorial articles published by several newspapers in four distinct regional contexts: Catalonia, Valencia, the Basque Country, as well as the whole of Spain. The analyzed articles were published a few days before and after July 10, 2010, and September 11, 2012

Medical error in the portuguese press: when patients are part of the news

Esta investigação aborda a qualidade da produção noticiosa sobre o erro médico, como um fator essencial na construção do conhecimento público sobre o tema, com o objetivo de compreender que características definem tal produção e até que ponto poderão ser explicadas pela periodicidade e orientação editorial dos jornais; que conceito de erro médico é veiculado pela produção noticiosa sobre o tema; e quais são os protagonistas no discurso jornalístico sobre o erro médico. Foram analisadas as edições de três jornais portugueses, de 2008 a 2011, resultando num corpus de 266 (4,2%) artigos, que foram classificados de acordo com as seguintes variáveis: as fontes de informação citadas (o seu estatuto e especialidade, no caso dos médicos); os temas que são tratados; as características de enquadramento da informação publicada (tom, género jornalístico; e a presença e número de fontes de informação). Pela análise de conteúdo quantitativa, apurou-se que esse tema está em crescimento, essencialmente com notícias de tom negativo e fontes de informação habitualmente identificadas. Não há evidência para afirmar que a periodicidade e a orientação editorial expliquem as variações dessas características, a não ser relativamente ao número de fontes citadas. Vigoram as notícias centradas nos resultados dos erros (mortes ou lesões), provocados por "erros de omissão" e por "erros de comissão", envolvendo uma diversidade de protagonistas: são, tal como acontece na informação sobre saúde em geral, fontes oficiais e especializadas do campo da saúde. Destacam-se os médicos e os juristas e é dado relevo aos pacientes.This research addresses the quality of news production on medical error, as an essential factor in building public knowledge on the subject, in order to understand which characteristics define the news production of medical error and to what extent can they be explained by the periodicity and editorial orientation of the newspaper; which concept of medical error is transmitted by the news production on the subject; and who are the main actors in the journalistic discourse about medical error. The editions of three Portuguese newspapers were analyzed, from 2008 to 2011, resulting in a corpus of 266 (4.2%) articles, which were classified according to the following variables: the sources of information quoted (their status and specialty, in the case of doctors); the issues covered; and characteristic framework of the published information (tone, journalistic style, and the presence and number of information sources). Through quantitative content analysis, it was found that this topic is growing, essentially with negative news and information sources usually being identified. There is no evidence to support that periodicity and editorial orientation explain the variations in these characteristics, except for the number of cited sources. News focused on the results of errors (death or injury), caused by "errors of omission" and "commission errors", prevail, involving a variety of actors: they are, such as it happens in health information, in general, official sources and experts in health. Doctors and lawyers stand out, and special attention is given to patients

Crítica de llibres

Armand MATTELART y Héctor SCHUMUCLER, América Latina en la encrucijada telemátic

Crítica de llibres

Armand MATTELART y Héctor SCHUMUCLER, América Latina en la encrucijada telemátic

Mortality after surgery in Europe: a 7 day cohort study

Background: Clinical outcomes after major surgery are poorly described at the national level. Evidence of heterogeneity between hospitals and health-care systems suggests potential to improve care for patients but this potential remains unconfirmed. The European Surgical Outcomes Study was an international study designed to assess outcomes after non-cardiac surgery in Europe.Methods: We did this 7 day cohort study between April 4 and April 11, 2011. We collected data describing consecutive patients aged 16 years and older undergoing inpatient non-cardiac surgery in 498 hospitals across 28 European nations. Patients were followed up for a maximum of 60 days. The primary endpoint was in-hospital mortality. Secondary outcome measures were duration of hospital stay and admission to critical care. We used χ² and Fisher’s exact tests to compare categorical variables and the t test or the Mann-Whitney U test to compare continuous variables. Significance was set at p<0·05. We constructed multilevel logistic regression models to adjust for the differences in mortality rates between countries.Findings: We included 46 539 patients, of whom 1855 (4%) died before hospital discharge. 3599 (8%) patients were admitted to critical care after surgery with a median length of stay of 1·2 days (IQR 0·9–3·6). 1358 (73%) patients who died were not admitted to critical care at any stage after surgery. Crude mortality rates varied widely between countries (from 1·2% [95% CI 0·0–3·0] for Iceland to 21·5% [16·9–26·2] for Latvia). After adjustment for confounding variables, important differences remained between countries when compared with the UK, the country with the largest dataset (OR range from 0·44 [95% CI 0·19 1·05; p=0·06] for Finland to 6·92 [2·37–20·27; p=0·0004] for Poland).Interpretation: The mortality rate for patients undergoing inpatient non-cardiac surgery was higher than anticipated. Variations in mortality between countries suggest the need for national and international strategies to improve care for this group of patients.Funding: European Society of Intensive Care Medicine, European Society of Anaesthesiology