A IMPORTÂNCIA DAS MACRÓFITAS AQUÁTICAS NO CICLO DO MERCÚRIO NA BACIA DO RIO TAPAJÓS (PA)

Studies about the mercury (Hg) cycle in the Amazon region indicate that deforestation is a main source of Hg to aquatic systems. The atmospheric Hg deposits in soil have a great affinity with Iron (Fe) and Aluminum (Al) oxyhidroxides that are carried to waters by runoff during rainy season. Constituting the fine particulate matter (FPM), Hg is accumulated in aquatic macrophytes roots, a main site of methylmercury (MeHg) production, permitting biomagnification of the neurotoxic MeHg. During wet season, the organic material, humic and fulvic acids and Hg associated to clayed sediments from inundated forest seem to intensify biotic and abiotic Hg methylation. The reducing and acidic conditions may facilitate the bioavailability of the reactive Hg and a higher transference of the produced MeHg is expected as a function of microbial activity and diversity. During the dry season, Hg may return to the atmospheric and terrestrial systems as a consequence of macrophyte decomposition.Os estudos sobre o ciclo do mercúrio (Hg) na região amazônica durante os últimos 20 anos indicam que a atual fonte de contaminação do meio aquático é o desmatamento. O Hg que se deposita no sistema terrestre tem grande afinidade com os oxihidróxidos de Ferro (Fe) e Alumínio (Al), que são carreados por lixiviação durante o período de chuvas. Esses elementos integram o material particulado fino (MPF) e são acumulados em raízes de macrófitas aquáticas, principal local de formação do metilmercúrio (MeHg), composto neurotóxico biomagnificado na cadeia trófica. Durante o período de cheia, a inundação da floresta fornece material orgânico, ácidos húmicos e fúlvicos e Hg junto com sedimentos argilosos, que formam um ambiente favorável à metilação biótica e abiótica do Hg. As condições reduzidas e de pH ácido podem favorecer a biodisponibilidade do Hg e a diversidade e atividade de microrganismos podem intensificar o processo de transferência trófica do MeHg produzido. Durante o período de seca, as macrófitas se decompõem e o Hg, possivelmente, retorna aos sistemas atmosférico e terrestre.

Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362