Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 21
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Environ Res ; 206: 112595, 2022 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-34929191

RESUMO

Plastic, paper and cardboard are widely used as food contact materials (FCMs), due to its numerous favourable characteristics. However, they are usually coated with hazardous substances, such as per- and polyfluorinated alkyl substances (PFASs). PFASs, with its functional properties of oil- and water-repellency, can migrate from FCMs into the food and cause potential risk to human health. There are also increasing concerns about the harm that FCMs can cause to the environment. These concerns include accumulation of non-degradable plastics in the environment, generation of microplastics (MPs) and nanoplastics, and release of PFASs from FCMs. While many reviews have been conducted on PFASs in the environment, including their occurrence, fate, toxicity, biodegradation, migration in ecosystems and remediation technologies, a systematic review of PFASs in FCMs and MPs is currently lacking. In addition, our knowledge of the PFAS sorption processes on MPs is rather limited, and in particular their desorption processes. Thus, this review aims to (1) review the presence of various classes of PFASs in FCMs and their migration into food, (2) review the PFASs in MPs and summarize the sorption mechanisms, and factors that influence their sorption behaviour on MPs in the aquatic environment, and (3) identify the current research gaps and future research directions to predict the risks associated with the presence and sorption of PFASs in FCMs and MPs.


Assuntos
Fluorocarbonos , Poluentes Químicos da Água , Ecossistema , Fluorocarbonos/análise , Humanos , Microplásticos , Plásticos , Poluentes Químicos da Água/análise
2.
Proc Natl Acad Sci U S A ; 112(1): E15-20, 2015 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-25535372

RESUMO

The supply and bioavailability of dissolved iron sets the magnitude of surface productivity for ∼ 40% of the global ocean. The redox state, organic complexation, and phase (dissolved versus particulate) of iron are key determinants of iron bioavailability in the marine realm, although the mechanisms facilitating exchange between iron species (inorganic and organic) and phases are poorly constrained. Here we use the isotope fingerprint of dissolved and particulate iron to reveal distinct isotopic signatures for biological uptake of iron during a GEOTRACES process study focused on a temperate spring phytoplankton bloom in subtropical waters. At the onset of the bloom, dissolved iron within the mixed layer was isotopically light relative to particulate iron. The isotopically light dissolved iron pool likely results from the reduction of particulate iron via photochemical and (to a lesser extent) biologically mediated reduction processes. As the bloom develops, dissolved iron within the surface mixed layer becomes isotopically heavy, reflecting the dominance of biological processing of iron as it is removed from solution, while scavenging appears to play a minor role. As stable isotopes have shown for major elements like nitrogen, iron isotopes offer a new window into our understanding of the biogeochemical cycling of iron, thereby allowing us to disentangle a suite of concurrent biotic and abiotic transformations of this key biolimiting element.


Assuntos
Ecossistema , Ferro/análise , Marcação por Isótopo , Fitoplâncton/crescimento & desenvolvimento , Clima Tropical , Fracionamento Químico , Precipitação Química , Clorofila/análise , Isótopos de Ferro , Material Particulado/análise , Comunicações Via Satélite
3.
J Perinat Med ; 43(2): 141-6, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24964255

RESUMO

OBJECTIVE: Obesity is an important issue among fertile women as it may affect obstetric and neonatal outcomes. METHODS: Obstetric and neonatal outcomes of primiparous women were retrospectively analyzed in non-obese (n=11387) and obese (n=943) women. A subgroup analysis was performed in obese women divided into three groups: Grade I obesity (Group A, n=654), Grade II obesity (Group B, n=192), and Grade III obesity (Group C, n=97). Odds ratios (OR) were expressed with the corresponding 95% confidence intervals (CI). RESULTS: The incidence of gestational diabetes (non-obese, 1.9%; obese, 7.6%; Group C, 19.6%) and preeclampsia (non-obese, 3.3%; obese, 13.5%; Group C, 17.5%) increased with rising weight. The risk of non-elective cesarean section was significantly higher in obese women than in non-obese women (21.7% vs. 13.2%). The risk of extreme preterm birth (before 28 weeks of gestation) doubled in the Grade I obesity group (OR, 2.1; 95% CI, 1.4-3.2) and nearly tripled in women with body mass index ≥35 kg/m2 (OR, 2.9; 95% CI, 1.7-4.9). CONCLUSION: Pre-pregnancy obesity is associated with higher incidences of gestational diabetes and preeclampsia. Our study shows that obese women have a higher risk of non-elective cesarean section and preterm birth.


Assuntos
Obesidade/complicações , Complicações na Gravidez/etiologia , Adulto , Cesárea/estatística & dados numéricos , Feminino , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Paridade , Gravidez , Estudos Retrospectivos , Adulto Jovem
5.
Metabolites ; 13(7)2023 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-37512545

RESUMO

The development of new tools for assessing the health of cultured shellfish larvae is crucial for aquaculture industries to develop and refine hatchery methodologies. We established a large-volume ecotoxicology/health stressor trial, exposing mussel (Perna canaliculus) embryos to copper in the presence of ethylenediaminetetraacetic acid (EDTA). GC/MS-based metabolomics was applied to identify potential biomarkers for monitoring embryonic/larval health and to characterise mechanisms of metal toxicity. Cellular viability, developmental abnormalities, larval behaviour, mortality, and a targeted analysis of proteins involved in the regulation of reactive oxygen species were simultaneously evaluated to provide a complementary framework for interpretative purposes and authenticate the metabolomics data. Trace metal analysis and speciation modelling verified EDTA as an effective copper chelator. Toxicity thresholds for P. canaliculus were low, with 10% developmental abnormalities in D-stage larvae being recorded upon exposure to 1.10 µg·L-1 bioavailable copper for 66 h. Sublethal levels of bioavailable copper (0.04 and 1.10 µg·L-1) caused coordinated fluctuations in metabolite profiles, which were dependent on development stage, treatment level, and exposure duration. Larvae appeared to successfully employ various mechanisms involving the biosynthesis of antioxidants and a restructuring of energy-related metabolism to alleviate the toxic effects of copper on cells and developing tissues. These results suggest that regulation of trace metal-induced toxicity is tightly linked with metabolism during the early ontogenic development of marine mussels. Lethal-level bioavailable copper (50.3 µg·L-1) caused severe metabolic dysregulation after 3 h of exposure, which worsened with time, substantially delayed embryonic development, induced critical oxidative damage, initiated the apoptotic pathway, and resulted in cell/organism death shortly after 18 h of exposure. Metabolite profiling is a useful approach to (1) assess the health status of marine invertebrate embryos and larvae, (2) detect early warning biomarkers for trace metal contamination, and (3) identify novel regulatory mechanisms of copper-induced toxicity.

6.
Environ Pollut ; 292(Pt B): 118398, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34695516

RESUMO

Despite the ubiquity of per- and polyfluorinated alkyl substances (PFAS) in all environmental compartments, little is known about the pollution they cause on the African continent, neither on levels, nor effects. Here we examined the occurrence and levels of 21 legacy and emerging PFAS in 9 marine species (3 fish, 2 crustaceans and 4 mollusks) collected from Bizerte lagoon, Northern Tunisia. Furthermore, assessment of potential human health risks through consumption of contaminated seafood was examined. This is the first study assessing PFAS in Mediterranean coastal areas of North Africa. Twelve out of the 21 targeted PFAS were detected, evidencing the occurrence of PFAS in seafood from North Africa, albeit at low levels. The Æ©21PFAS concentrations in all seafood samples ranged from 0.202 ng g-1 dry weight (dw) to 2.89 ng g-1 dw, with a mean value of 1.10 ± 0.89 ng g-1 dw. The profiles of PFAS varied significantly among different species, which might be related to their different trophic level, protein content, feeding behaviour and metabolism. Generally, current exposure to PFAS through seafood consumption indicates that it should not be of concern to the local consumers, at least for those PFAS for which information is available.


Assuntos
Fluorocarbonos , Poluentes Químicos da Água , Animais , Ecossistema , Monitoramento Ambiental , Peixes , Fluorocarbonos/análise , Humanos , Alimentos Marinhos , Poluentes Químicos da Água/análise
7.
Sci Rep ; 12(1): 20723, 2022 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-36456707

RESUMO

Iron (Fe) is an essential trace element for life. In the ocean, Fe can be exceptionally scarce and thus biolimiting or extremely enriched causing microbial stress. The ability of hydrothermal plume microbes to counteract unfavorable Fe-concentrations up to 10 mM is investigated through experiments. While Campylobacterota (Sulfurimonas) are prominent in a diverse community at low to intermediate Fe-concentrations, the highest 10 mM Fe-level is phylogenetically less diverse and dominated by the SUP05 clade (Gammaproteobacteria), a species known to be genetically well equipped to strive in high-Fe environments. In all incubations, Fe-binding ligands were produced in excess of the corresponding Fe-concentration level, possibly facilitating biological Fe-uptake in low-Fe incubations and detoxification in high-Fe incubations. The diversity of Fe-containing formulae among dissolved organics (SPE-DOM) decreased with increasing Fe-concentration, which may reflect toxic conditions of the high-Fe treatments. A DOM-derived degradation index (IDEG) points to a degradation magnitude (microbial activity) that decreases with Fe and/or selective Fe-DOM coagulation. Our results show that some hydrothermal microbes (especially Gammaproteobacteria) have the capacity to thrive even at unfavorably high Fe-concentrations. These ligand-producing microbes could hence play a key role in keeping Fe in solution, particularly in environments, where Fe precipitation dominates and toxic conditions prevail.


Assuntos
Epsilonproteobacteria , Gammaproteobacteria , Microbiota , Transporte Biológico , Coagulação Sanguínea
8.
Environ Sci Technol ; 45(15): 6388-95, 2011 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-21751821

RESUMO

Speciation affects trace metal bioavailability. One model used to describe the importance of speciation is the biotic ligand model (BLM), wherein the competition of inorganic and organic ligands with a biotic ligand for free-ion trace metal determines the ultimate metal availability to biota. This and similar models require natural ligand concentrations and conditional stability constants as input parameters. In concept, the BLM is itself an analogue of some analytical approaches to the determination of trace metal speciation. A notable example is competitive ligand equilibration/cathodic stripping voltammetry, which employs an artificial ligand for comparative assessment of natural ligand concentrations and discrete conditional stability constants (i.e., BLM parameters) in a natural sample. Here, we report a new numerical approach to voltammetric speciation and parameter estimation that employs multiple analytical windows and a two-step optimization process, simultaneously generating both parameters and a complete suite of corresponding species concentrations. This approach is more powerful, systematic, and flexible than those previously reported.


Assuntos
Metais/análise , Modelos Químicos , Análise Numérica Assistida por Computador , Oligoelementos/análise , Algoritmos , Disponibilidade Biológica , Cobre/análise , Água Doce/química , Ligantes , Água do Mar/química
9.
Environ Sci Pollut Res Int ; 28(42): 59345-59357, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33026620

RESUMO

Two different sample preparation protocols for the determination of 37 emerging and historical halogenated flame retardants (HFRs) in marine tissues were compared with regards to extraction recovery, lipid removal efficiency, repeatability, reproducibility, and ability to measure sub-ng g-1 (dry weight) concentrations in marine biota. One method involved a purification step using gel permeation chromatography (GPC) followed by a HPLC fractionation step on a Partisil amino-cyano normal phase (GPC-Partisil procedure) and the other more traditional method was based on sulphuric acid treatment followed by silica column fractionation (H2SO4-silica procedure). The samples were analysed by gas chromatography (GC) and liquid chromatography (LC) tandem mass spectrometry (MS/MS). Sample fractionation in both methods enabled unique sample preparation procedures to isolate the GC from the LC amenable compounds. Both methods could remove > 99% of the lipids which was necessary prior to GC- and LC-MS/MS analyses. The majority of the target compounds (70%) had acceptable recoveries between 60-120% for both methods. However, the sulphuric acid treatment resulted in the degradation of the TBP-AE and the silica column fractionation resulted in the loss of BEH-TEBP and the elution of PBB-Acr and TBBPA-BME in the unsuitable fraction. High recoveries of DBE-DBCH (α+ß), EHTBB, BTBPE, BEH-TEBP, and PBB-Acr were attributed to matrix effects, suggesting the need to use isotope-labelled surrogate standards of the target compounds. The optimisation of the silica column chromatography, GPC, and Partisil fractionation is described and discussed to afford easy implementation of the method. The method using GPC followed by Partisil fractionation is more efficient and more reproducible than the sulphuric acid-silica procedure. The application of this method to marine biota reference materials revealed the presence of relatively high concentrations of DBE-DBCH isomers and BDE-47 in fish samples. The method detection limits comply with the recommendations of the European Commission.


Assuntos
Retardadores de Chama , Animais , Biota , Cromatografia Líquida , Retardadores de Chama/análise , Cromatografia Gasosa-Espectrometria de Massas , Reprodutibilidade dos Testes , Espectrometria de Massas em Tandem
10.
Appl Environ Microbiol ; 76(20): 6955-61, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20802068

RESUMO

The biochemical and molecular mechanisms used by alkaliphilic bacteria to acquire iron are unknown. We demonstrate that alkaliphilic (pH > 9) Bacillus species are sensitive to artificial iron (Fe³+) chelators and produce iron-chelating molecules. These alkaliphilic siderophores contain catechol and hydroxamate moieties, and their synthesis is stimulated by manganese(II) salts and suppressed by FeCl3 addition. Purification and mass spectrometric characterization of the siderophore produced by Caldalkalibacillus thermarum failed to identify any matches to previously observed fragmentation spectra of known siderophores, suggesting a novel structure.


Assuntos
Bacillaceae/metabolismo , Ferro/metabolismo , Catecóis/análise , Cloretos/metabolismo , Compostos Férricos/metabolismo , Ácidos Hidroxâmicos/análise , Quelantes de Ferro/química , Quelantes de Ferro/isolamento & purificação , Quelantes de Ferro/metabolismo , Manganês/metabolismo , Espectrometria de Massas , Sideróforos/química , Sideróforos/isolamento & purificação , Sideróforos/metabolismo
11.
Sci Total Environ ; 653: 300-314, 2019 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-30412875

RESUMO

Copper (Cu) is a naturally occurring micronutrient of eco-toxicological concern in aquatic ecosystems. Current knowledge of Cu-speciation and bioavailability in natural saline environments is insufficient to adequately inform environmental protection policy for estuarine systems. We assessed the combined effect of two of the main drivers of metal bioavailability, salinity and natural dissolved organic carbon (DOC), on Cu-speciation and associated Cu-toxicity to blue mussel (Mytilus galloprovincialis) embryos in a standard 48-h bioassay. We placed special emphasis on measurement of Cu-speciation rather than modelling. Cu-toxicity was found to be a function of DOC and salinity. The varying protective effect of different DOC-types suggests that estuarine DOC is more protective against Cu-toxicity than oceanic DOC. Salinity was negatively correlated with [Cu48-h-EC50], indicating a salinity-induced alteration in the physiology of the exposed mussel embryos and/or Cu-DOC-reactivity. These two assumptions were supported by (1) the relative uniformity of bioavailable copper ([Cu']) across similar salinity treatments despite considerable variation in [Cu48-h-EC50] and DOC-concentrations, and (2) the fact that Cu-toxicity and [Cu'] were slightly higher in the 35 salinity treatment compared to the 25 salinity treatment. Stripping voltammetry studies determined the presence of only one strong Cu-binding ligand class (i.e., L1), either actively or passively released by the exposed embryos. [L1] was found to be proportional to the total dissolved Cu-concentration ([CuT]), suggesting a protective effect of Cu-binding-ligands, in addition to the protective effect of DOC. There was also a strong positive correlation between [L1] and [Cu48-h-EC50], implying that electrochemically defined ligand concentrations along with measurements of [Cu'], DOC-quality, and salinity can be used as proxies for 48-h-EC50 Cu-values in estuarine waters, which may result in a significant improvement to risk assessments of Cu in estuarine systems.


Assuntos
Cobre/toxicidade , Substâncias Húmicas/análise , Mytilus/efeitos dos fármacos , Salinidade , Poluentes Químicos da Água/toxicidade , Animais , Cobre/química , Embrião não Mamífero/efeitos dos fármacos , Mytilus/embriologia , Distribuição Aleatória , Testes de Toxicidade Aguda , Poluentes Químicos da Água/química
12.
Environ Toxicol Chem ; 38(3): 561-574, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30623479

RESUMO

The production of accurate and reliable data on metal toxicity during ecotoxicological bioassays is important for credible environmental risk assessments and management in aquatic environments. Actual measurements and reporting of contaminant concentrations in bioassays are, however, often disregarded; and potential contaminant loss attributable to adsorption processes (e.g., wall adsorption) in bioassays is widely omitted, which can have detrimental effects on calculated metal toxicity thresholds. In the present we assessed copper (Cu) mass balance during a standard 48-h bioassay test with blue mussel (Mytilus galloprovincialis) embryos to evaluate effects on calculated toxicity endpoints. We demonstrated that measured Cu concentrations at the test conclusion need to be used to quantify the risk of Cu toxicity because nominal Cu and initial Cu concentrations underestimate overall Cu toxicity by up to 1.5-fold, owing to Cu loss in solution attributable to adsorption and bioaccumulation processes. For the first time we provide evidence that extracellular adsorption to the biological surface of the embryos is the most important sink for total dissolved Cu in a bioassay. We also established that adsorbed extracellular Cu accumulation reduces Cu toxicity to embryos, potentially by inhibiting Cu from entering the cell of the mussel embryo. Environmental factors (e.g., salinity and dissolved organic carbon) did not influence the partitioning of Cu within the laboratory-based bioassay. The present results 1) demonstrate the importance of differentiating extra- and intracellular Cu pools to improve our understanding of Cu toxicity and associated processes, 2) reveal the potential for bias with respect to calculated Cu toxicity thresholds when results are based on nominal and initial Cu concentrations, and 3) point out the need to follow current guidelines for the testing of chemicals to standardize toxicity tests and data reporting. Environ Toxicol Chem 2019;38:561-574. © 2019 SETAC.


Assuntos
Cobre/toxicidade , Testes de Toxicidade , Poluentes Químicos da Água/toxicidade , Adsorção , Animais , Bioensaio , Cobre/análise , Embrião não Mamífero/efeitos dos fármacos , Mytilus/efeitos dos fármacos , Mytilus/embriologia , Salinidade , Poluentes Químicos da Água/análise
13.
Sci Rep ; 9(1): 9573, 2019 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-31267013

RESUMO

Pollution from the grounding or sinking of ships can have long lasting effects on the recovery and dynamics of coastal ecosystems. Research on the impact of copper (Cu) pollution from the 2011 MV Rena shipwreck at the Astrolabe Reef (Otaiti), New Zealand, 5 years after the grounding, followed a multi-method and multi-disciplinary approach. Three independent measures of aqueous Cu using trace-element-clean-techniques substantiate the presence of high total, total dissolved (<2 µm) and elevated bioavailable Cu in the water column immediately above the aft section of the wreck where the highest sedimentary load of Cu was located. Intermittently elevated concentrations of strong Cu-binding ligands occurred in this location, and their binding strength was consistent with ligands actively produced by organisms in response to Cu induced stress. The recruitment of benthic invertebrates was modified at the high-Cu location. Taxonomic groups usually considered robust to pollution were restricted to this site (e.g. barnacles) or were the most abundant taxa present (e.g. foraminifera). Our results demonstrate that Cu-contaminated sediments can impose a persistent point source of Cu pollution in high-energy reef environments, with the potential to modify the composition and recovery of biological communities.

14.
Front Microbiol ; 10: 2296, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31649639

RESUMO

The microbial community composition and its functionality was assessed for hydrothermal fluids and volcanic ash sediments from Haungaroa and hydrothermal fluids from the Brothers volcano in the Kermadec island arc (New Zealand). The Haungaroa volcanic ash sediments were dominated by epsilonproteobacterial Sulfurovum sp. Ratios of electron donor consumption to CO2 fixation from respective sediment incubations indicated that sulfide oxidation appeared to fuel autotrophic CO2 fixation, coinciding with thermodynamic estimates predicting sulfide oxidation as the major energy source in the environment. Transcript analyses with the sulfide-supplemented sediment slurries demonstrated that Sulfurovum prevailed in the experiments as well. Hence, our sediment incubations appeared to simulate environmental conditions well suggesting that sulfide oxidation catalyzed by Sulfurovum members drive biomass synthesis in the volcanic ash sediments. For the Haungaroa fluids no inorganic electron donor and responsible microorganisms could be identified that clearly stimulated autotrophic CO2 fixation. In the Brothers hydrothermal fluids Sulfurimonas (49%) and Hydrogenovibrio/Thiomicrospira (15%) species prevailed. Respective fluid incubations exhibited highest autotrophic CO2 fixation if supplemented with iron(II) or hydrogen. Likewise catabolic energy calculations predicted primarily iron(II) but also hydrogen oxidation as major energy sources in the natural fluids. According to transcript analyses with material from the incubation experiments Thiomicrospira/Hydrogenovibrio species dominated, outcompeting Sulfurimonas. Given that experimental conditions likely only simulated environmental conditions that cause Thiomicrospira/Hydrogenovibrio but not Sulfurimonas to thrive, it remains unclear which environmental parameters determine Sulfurimonas' dominance in the Brothers natural hydrothermal fluids.

15.
Sci Rep ; 8(1): 14763, 2018 10 03.
Artigo em Inglês | MEDLINE | ID: mdl-30283041

RESUMO

Ocean warming (OW), ocean acidification (OA) and their interaction with local drivers, e.g., copper pollution, may negatively affect macroalgae and their microscopic life stages. We evaluated meiospore development of the kelps Macrocystis pyrifera and Undaria pinnatifida exposed to a factorial combination of current and 2100-predicted temperature (12 and 16 °C, respectively), pH (8.16 and 7.65, respectively), and two copper levels (no-added-copper and species-specific germination Cu-EC50). Meiospore germination for both species declined by 5-18% under OA and ambient temperature/OA conditions, irrespective of copper exposure. Germling growth rate declined by >40%·day-1, and gametophyte development was inhibited under Cu-EC50 exposure, compared to the no-added-copper treatment, irrespective of pH and temperature. Following the removal of copper and 9-day recovery under respective pH and temperature treatments, germling growth rates increased by 8-18%·day-1. The exception was U. pinnatifida under OW/OA, where growth rate remained at 10%·day-1 before and after copper exposure. Copper-binding ligand concentrations were higher in copper-exposed cultures of both species, suggesting that ligands may act as a defence mechanism of kelp early life stages against copper toxicity. Our study demonstrated that copper pollution is more important than global climate drivers in controlling meiospore development in kelps as it disrupts the completion of their life cycle.


Assuntos
Cobre/toxicidade , Células Germinativas Vegetais/efeitos dos fármacos , Germinação/efeitos dos fármacos , Macrocystis/efeitos dos fármacos , Undaria/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Mudança Climática , Células Germinativas Vegetais/fisiologia , Germinação/fisiologia , Temperatura Alta , Concentração de Íons de Hidrogênio , Macrocystis/fisiologia , Oceanos e Mares , Água do Mar/química , Undaria/fisiologia
16.
Front Microbiol ; 9: 3190, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30619234

RESUMO

Marine microbes are an important control on the biogeochemical cycling of trace metals, but simultaneously, these metals can control the growth of microorganisms and the cycling of major nutrients like C and N. However, studies on the response/limitation of microorganisms to trace metals have traditionally focused on the response of autotrophic phytoplankton to Fe fertilization. Few reports are available on the response of heterotrophic prokaryotes to Fe, and even less to other biogeochemically relevant metals. We performed the first study coupling dark incubations with next generation sequencing to specifically target the functional and phylogenetic response of heterotrophic prokaryotes to Fe enrichment. Furthermore, we also studied their response to Co, Mn, Ni, Zn, Cu (individually and mixed), using surface and deep samples from either coastal or open-ocean waters. Heterotrophic prokaryotic activity was stimulated by Fe in surface open-ocean, as well as in coastal, and deep open-ocean waters (where Zn also stimulated). The most susceptible populations to trace metals additions were uncultured bacteria (e.g., SAR324, SAR406, NS9, and DEV007). Interestingly, hydrocarbon-degrading bacteria (e.g., Thalassolituus, Marinobacter, and Oleibacter) benefited the most from metal addition across all waters (regions/depths) revealing a predominant role in the cycling of metals and organic matter in the ocean.

17.
Ann Otol Rhinol Laryngol ; 125(4): 331-5, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26530095

RESUMO

OBJECTIVES: To analyze the prognostic relevance of mucosal waves (MWs) for recovery of unilateral vocal fold paralysis (UVP). METHODS: The charts and stroboscopic examinations of 100 consecutive patients with a complete UVP were reviewed retrospectively. All had a minimal (estimated <3 mm) mucosal gap on stroboscopy. A positive or negative MW on the paralyzed vocal fold was associated with complete recovery to full adduction and abduction. All patients were followed for at least 12 months. RESULTS: Causes of the paralysis were iatrogenic/traumatic (n = 82), malignancy associated (n = 10), and idiopathic (n = 8). In patients with positive MW at diagnosis (n = 80), the chance of recovery of unilateral vocal fold paralysis was 91.25%, whereas the chance of recovery with a negative mucosal wave (n = 20) was only 10%. CONCLUSION: Positive MWs in stroboscopy are a predictor for recovery of (iatrogenic/traumatic) unilateral vocal fold paralysis and should be used in routine diagnostic assessment.


Assuntos
Recuperação de Função Fisiológica , Estroboscopia , Paralisia das Pregas Vocais/diagnóstico , Prega Vocal/fisiopatologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Feminino , Humanos , Laringoscopia , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Paralisia das Pregas Vocais/fisiopatologia , Adulto Jovem
18.
Environ Pollut ; 194: 138-144, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25108489

RESUMO

The current study aims to understand the speciation and fate of Cu complexes in hydrothermally altered sediments from the Central Indian Ocean Basin and assess the probable impacts of deep-sea mining on speciation of Cu complexes and assess the Cu flux from this sediment to the water column in this area. This study suggests that most of the Cu was strongly associated with different binding sites in Fe-oxide phases of the hydrothermally altered sediments with stabilities higher than that of Cu-EDTA complexes. The speciation of Cu indicates that hydrothermally influenced deep-sea sediments from Central Indian Ocean Basin may not significantly contribute to the global Cu flux. However, increasing lability of Cu-sediment complexes with increasing depth of sediment may increase bioavailability and Cu flux to the global ocean during deep-sea mining.


Assuntos
Cobre/análise , Sedimentos Geológicos/química , Fontes Hidrotermais , Poluentes Químicos da Água/análise , Monitoramento Ambiental , Oceano Índico , Mineração
19.
Int J Colorectal Dis ; 22(1): 49-55, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16538493

RESUMO

BACKGROUND AND AIMS: Thymidylate synthase (TS) is an important enzyme for DNA synthesis and the target for 5-fluorouracil (5-FU). Its expression may determine the outcome of patients with gastrointestinal cancers. We examined the prognostic and predictive value of TS-protein expression in patients with ductal adenocarcinoma of the pancreas. METHODS: TS expression from 131 patients with ductal adenocarcinoma of the pancreas was analyzed by immunohistochemistry in paraffin-embedded primary tumour specimens or biopsies. RESULTS: The median disease-specific survival among all patients (n=131) was 13 months. The invasion depth, the presence of metastases, grading and Union Internationale Contre le Cancer [International Union Against Cancer] (UICC) stage were associated with survival. Among resected patients (n=98), a difference in median survival was seen in the group receiving postoperative adjuvant treatment (21.1 months) compared with the group treated by surgery alone (12.4 months) (p=0.025). Low- and high-TS immunoreactivity was present in 74 (56%) and 56 (43%) of the cancers, respectively. One sample was not evaluable. No difference in median survival was observed among low- and high-TS-expressing tumours. Among patients undergoing resection and receiving postoperative intra-arterial chemotherapy (n=23), a marked trend to a longer median survival was seen for the group with low-TS-expressing tumours compared with the corresponding high-TS group (25.0 vs 16.0 months) (p=0.3834). There was no difference in survival among all palliative treated patients with low- and high-TS-expressing tumours. CONCLUSION: Especially patients undergoing tumour resection with low-TS values seemed to have taken advantage from an intensified postoperative chemotherapeutic protocol. However due to the heterogeneous group of patients in the present report, larger trials of more homogenous patient populations will be necessary to confirm this hypothesis.


Assuntos
Carcinoma Ductal Pancreático/enzimologia , Pancreatectomia/métodos , Neoplasias Pancreáticas/enzimologia , Timidilato Sintase/biossíntese , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/biossíntese , Carcinoma Ductal Pancreático/mortalidade , Carcinoma Ductal Pancreático/cirurgia , Feminino , Seguimentos , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Neoplasias Pancreáticas/mortalidade , Neoplasias Pancreáticas/cirurgia , Prognóstico , Estudos Retrospectivos , Índice de Gravidade de Doença , Taxa de Sobrevida/tendências
20.
Aging Clin Exp Res ; 17(3): 186-92, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16110730

RESUMO

BACKGROUND AND AIMS: The process applied to identify fall risks in frail elderly persons remains a matter of debate. We intended to develop a fall screening instrument for clinically defined subgroups of long-term care residents, to be administered by nursing staff. METHODS: Fall risk indicators were selected by multiple logistic regression in three pre-defined subgroups. The first consisted of residents who were not able to transfer, defined as a change from sit-to-stand position, without physical assistance (NAT). The second subgroup comprised residents who were able to transfer, but who had had a recent fall during the last 6 months (AT-F). Residents who were able to transfer but had had no recent fall (AT-NF) were in the third subgroup. The prospective observational study included 472 long-stay residents (mean age 84 years, 79% female) from three community nursing homes, with a follow-up period of 12 months. RESULTS: Fall incidence was highest in the AT-F subgroup: 6066 per 1000 resident years. The risk indicators identified included a positive fall history and restraint use in the NAT group, transfer assistance in the AT-F group, and urinary incontinence and visual impairment in the AT-NF group. CONCLUSIONS: The identification of different risk indicators in the subgroups indicates that specific strategies may be more appropriate to improve the effectiveness of fall prevention in long-term care, than the application of one strategy to all residents. The identification of incontinence, visual impairment, and restraints as risk indicators stresses the need for intervention studies which specifically address these items.


Assuntos
Acidentes por Quedas/estatística & dados numéricos , Algoritmos , Acidentes por Quedas/prevenção & controle , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Idoso Fragilizado , Avaliação Geriátrica/métodos , Avaliação Geriátrica/estatística & dados numéricos , Humanos , Modelos Logísticos , Assistência de Longa Duração , Masculino , Transtornos da Memória , Pessoa de Meia-Idade , Atividade Motora , Razão de Chances , Reprodutibilidade dos Testes , Restrição Física , Medição de Risco/métodos , Fatores de Risco , Incontinência Urinária , Transtornos da Visão
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA