Especiacao e biogeoquimica do arsenio no estuario do Tejo.

In this work it has been investigated the question of arsenic speciation in the estuarine environment and of the biogeochemical mechanisms that eventually control it. Particularly we have tried to study, in the Tagus estuary, the distribution of As"3"+, As"5"+, MMA and DMA for different seasonal and hydrodynamic conditions. In this connection tri methylated forms of arsenic (Tma) were detected and quantified for the first time in natural sea water. The attempt to identify the source of the tri methylated forms still allowed the detection and quantification of two unknown fractions of dissolved arsenic, refractory to the production of arsines. These fractions can be distinguished through their different sensitivity to alkaline digestion. We have further tried to characterize physically and chemically these two refractory fractions and particularly proceed to the identification of their chemical structure. From these efforts it has followed the identification, through mass fragmentometry, of arseno choline, in a methanol extract of a water fraction, purified by ion exchange.Available from Fundacao para a Ciencia e a Tecnologia, Servico de Informacao e Documentacao, Av. D. Carlos I, 126, 1249-074 Lisboa, Portugal / FCT - Fundação para o Ciência e a TecnologiaSIGLEPTPortuga

Especiação e Biogeoquímica do Arsénio no Estuário do Tejo

SUMÁRIO Neste trabalho foi aprofundaria a questão da especiação do arsénio em meio estuarino e analisados os possíveis mecanismos biogeoquímicos que a controlam. Em particular procurou estudar-se, no estuário do Tejo, a distribuição de AS3+, As5+, MMA e DMA em diferentes épocas do ano e para diferentes condições hidrodinâmicas. Neste contexto detectaram-se e quantificaram-se, pela primeira vez em águas naturais marinhas, formas trimetiladas de arsénio (MA). Os esforços desenvolvidos para esclarecer a origem das formas trimetiladas permitiram ainda a detecção e quantificação de duas fracções desconhecidas de arsénio dissolvido refractárias à produção de arsinas e que se distinguem entre si pela diferente sensibilidade à digestão alcalina. Procurou caracterizar-se física e quimicamente essas fracções e nomeadamente proceder à identificação da sua estrutura química. Resultou daí a identificação por fragmentometria de massa, de arsenocolina num extracto em metanol de uma fracção aquosa purificada por troca fónica. Foi também recolhida evidência que sugere a presença, nas águas do estuário, de arsenobetaina e de tetrametilarsónio. Com base nestes resultados reexaminou-se o conjunto de mecanismos responsáveis pela biotransformação e reciclagem do arsénio em meio estuarino retirando-se consequências nomeadamente no que respeita ao esclarecimento da origem da arsenobetaina nos tecidos de animais marinhos e ao significado tóxicológico e ecotóxicológico das novas fracções encontradas.;SUMMARY In this work it has been investigated the question of arsenic speciation in the estuarine environment and of the biogeochemical mechanisms that eventually control it. Particularly we have tried to study, in the Tagus estuary, the distribution of As3+, AS5+, MMA and DMA for different seasonal and hydrodynamic conditions. In this connection trimethylated forms of arsenic (TMA) were detected and quantified for the first time in natural sea water. The attempt to identify the source of the trimethylated forms still allowed the detection and quantification of two unknown fractions of dissolved arsenic, refractory to the production of arsines. These fractions can be distinguished through their different sensivity to alcaline digestion. We have further tried to characterize physically and chemically these two refractory fractions and particularly proceed to the identification of their chemical structure. Froco these efforts it has followed the identification, through mass fragmentometry, of arsenocholine, in a methanol extract of a water fraction, purified by ion-exchange. Evidence that suggests the presence, in estuarine waters, of arsenobetaine and of the tetramethylarsonium ion has also been collected. On these grounds the set of mechanisms responsible for the biotransformation and cycling of arsenic in the estuarine environment was reexamined. Particularly new suggestions are presented to clarify the question of the origin of arsenobetaine, in the tissue of marine animais. The toxicological and ecotoxicological significance of the new refractory fractions found are also analysed and discussed

Correction to: Comparative effectiveness and safety of non-vitamin K antagonists for atrial fibrillation in clinical practice: GLORIA-AF Registry

International audienceIn this article, the name of the GLORIA-AF investigator Anastasios Kollias was given incorrectly as Athanasios Kollias in the Acknowledgements. The original article has been corrected

Patterns of oral anticoagulant use and outcomes in Asian patients with atrial fibrillation: a post-hoc analysis from the GLORIA-AF Registry

Background: Previous studies suggested potential ethnic differences in the management and outcomes of atrial fibrillation (AF). We aim to analyse oral anticoagulant (OAC) prescription, discontinuation, and risk of adverse outcomes in Asian patients with AF, using data from a global prospective cohort study. Methods: From the GLORIA-AF Registry Phase II-III (November 2011-December 2014 for Phase II, and January 2014-December 2016 for Phase III), we analysed patients according to their self-reported ethnicity (Asian vs. non-Asian), as well as according to Asian subgroups (Chinese, Japanese, Korean and other Asian). Logistic regression was used to analyse OAC prescription, while the risk of OAC discontinuation and adverse outcomes were analysed through Cox-regression model. Our primary outcome was the composite of all-cause death and major adverse cardiovascular events (MACE). The original studies were registered with ClinicalTrials.gov, NCT01468701, NCT01671007, and NCT01937377. Findings: 34,421 patients were included (70.0 ± 10.5 years, 45.1% females, 6900 (20.0%) Asian: 3829 (55.5%) Chinese, 814 (11.8%) Japanese, 1964 (28.5%) Korean and 293 (4.2%) other Asian). Most of the Asian patients were recruited in Asia (n = 6701, 97.1%), while non-Asian patients were mainly recruited in Europe (n = 15,449, 56.1%) and North America (n = 8378, 30.4%). Compared to non-Asian individuals, prescription of OAC and non-vitamin K antagonist oral anticoagulant (NOAC) was lower in Asian patients (Odds Ratio [OR] and 95% Confidence Intervals (CI): 0.23 [0.22-0.25] and 0.66 [0.61-0.71], respectively), but higher in the Japanese subgroup. Asian ethnicity was also associated with higher risk of OAC discontinuation (Hazard Ratio [HR] and [95% CI]: 1.79 [1.67-1.92]), and lower risk of the primary composite outcome (HR [95% CI]: 0.86 [0.76-0.96]). Among the exploratory secondary outcomes, Asian ethnicity was associated with higher risks of thromboembolism and intracranial haemorrhage, and lower risk of major bleeding. Interpretation: Our results showed that Asian patients with AF showed suboptimal thromboembolic risk management and a specific risk profile of adverse outcomes; these differences may also reflect differences in country-specific factors. Ensuring integrated and appropriate treatment of these patients is crucial to improve their prognosis. Funding: The GLORIA-AF Registry was funded by Boehringer Ingelheim GmbH