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1.
Mar Pollut Bull ; 203: 116394, 2024 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-38705001

RESUMO

Seagrasses are marine flowering plants that create critical coastal ecosystems and are threatened by warming. Clonal expansion is generally the dominant strategy for meadow recovery, while sexual reproduction strongly differs among species (e.g., monoecious and diecious species, some creating seed banks, viviparous seedlings). In 2022, the Western Mediterranean underwent unprecedented warming, and, associated with it, we observed flowering (100 %) across 11 Posidonia oceanica meadows in Mallorca, Balearic Islands. Furthermore, 64 % of the sites also exhibited pseudovivipary, an extremely rare phenomenon in angiosperms whereby plantlets replace sexual reproductive structures, producing clones of the maternal plant. Our results support the notion that P. oceanica flowering and pseudovivipary (genetically confirmed) are triggered by warming, never before being pseudovivipary reported across multiple sites in a marine plant. Considering the negative impacts that warming can have on seagrasses, existence of widespread pseudovivipary is a critical aspect to consider for understanding mechanisms of resilience in seagrasses.

2.
Semin Arthritis Rheum ; 61: 152232, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37348350

RESUMO

INTRODUCTION: Obstetric complications are more common in women with systemic lupus erythematosus (SLE) than in the general population. OBJECTIVE: To assess pregnancy outcomes in women with SLE from the RELESSER cohort after 12 years of follow-up. METHODS: A multicentre retrospective observational study was conducted. In addition to data from the RELESSER register, data were collected on obstetric/gynaecological variables and treatments received. The number of term pregnancies was compared between women with pregnancies before and after the diagnosis of SLE. Further, clinical and laboratory characteristics were compared between women with pregnancies before and after the diagnosis, on the one hand, and with and without complications during pregnancy, on the other. Bivariate and multivariate analyses were carried out to identify factors potentially associated with complications during pregnancy. RESULTS: A total of 809 women were included, with 1869 pregnancies, of which 1395 reached term. Women with pregnancies before the diagnosis of SLE had more pregnancies (2.37 vs 1.87) and a higher rate of term pregnancies (76.8% vs 69.8%, p < 0.001) compared to those with pregnancies after the diagnosis. Women with pregnancies before the diagnosis were diagnosed at an older age (43.4 vs 34.1 years) and had more comorbidities. No differences were observed between the groups with pregnancies before and after diagnosis in antibody profile, including anti-dsDNA, anti-Sm, anti-Ro, anti-La, lupus anticoagulant, anticardiolipin or anti-beta-2-glycoprotein. Overall, 114 out of the 809 women included in the study experienced complications during pregnancy, including miscarriage, preeclampsia/eclampsia, foetal death, and/or preterm birth. Women with complications had higher rates of antiphospholipid syndrome (40.5% vs 9.9%, p < 0.001) and higher rates of positivity for IgG anticardiolipin (33.9% vs 21.3%, p = 0.005), IgG anti-beta 2 glycoprotein (26.1% vs 14%, p = 0.007), and IgM anti-beta 2 glycoprotein (26.1% vs 16%, p = 0.032) antibodies, although no differences were found regarding lupus anticoagulant. Among the treatments received, only heparin was more commonly used by women with pregnancy complications. We did not find differences in corticosteroid or hydroxychloroquine use. CONCLUSIONS: The likelihood of term pregnancy is higher before the diagnosis of SLE. In our cohort, positivity for anticardiolipin IgG and anti-beta-2- glycoprotein IgG/IgM, but not lupus anticoagulant, was associated with a higher risk of poorer pregnancy outcomes.


Assuntos
Síndrome Antifosfolipídica , Lúpus Eritematoso Sistêmico , Complicações na Gravidez , Nascimento Prematuro , Reumatologia , Gravidez , Humanos , Recém-Nascido , Feminino , Resultado da Gravidez/epidemiologia , Nascimento Prematuro/epidemiologia , Lúpus Eritematoso Sistêmico/complicações , Lúpus Eritematoso Sistêmico/diagnóstico , Lúpus Eritematoso Sistêmico/tratamento farmacológico , Síndrome Antifosfolipídica/diagnóstico , Síndrome Antifosfolipídica/epidemiologia , Síndrome Antifosfolipídica/complicações , Complicações na Gravidez/epidemiologia , Estudos Retrospectivos , beta 2-Glicoproteína I , Anticoagulantes , Imunoglobulina G , Imunoglobulina M
3.
Cureus ; 15(4): e38303, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37255911

RESUMO

Systemic sclerosis (SSc) is a chronic autoimmune disease with complex pathogenesis, characterized by vascular dysfunction and fibrosis. Digital ulcers (DUs) are a common and severe complication in SSc patients, negatively impacting their quality of life. This retrospective study evaluates the use of macitentan, an endothelin receptor antagonist, in six female patients with connective tissue disease (CTD) and sclerodermiform features (five SSc and one mixed connective tissue disease) for the treatment of refractory DUs. Macitentan demonstrated a safe and effective alternative to bosentan, reducing DU relapses, hospitalizations, and the use of systemic prostaglandin therapy. The findings suggest that macitentan may be a valuable therapeutic option in specific cases of recurrent or refractory DUs and warrant further investigation in larger, long-term studies.

4.
Semin Arthritis Rheum ; 58: 152121, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36375359

RESUMO

OBJECTIVES: To analyze the prevalence, incidence, survival and contribution on mortality of major central nervous system (CNS) involvement in systemic lupus erythematosus (SLE). METHODS: Patients fulfilling the SLE 1997 ACR classification criteria from the multicentre, retrospective RELESSER-TRANS (Spanish Society of Rheumatology Lupus Register) were included. Prevalence, incidence and survival rates of major CNS neuropsychiatric (NP)-SLE as a group and the individual NP manifestations cerebrovascular disease (CVD), seizure, psychosis, organic brain syndrome and transverse myelitis were calculated. Furthermore, the contribution of these manifestations on mortality was analysed in Cox regression models adjusted for confounders. RESULTS: A total of 3591 SLE patients were included. Of them, 412 (11.5%) developed a total of 522 major CNS NP-SLE manifestations. 61 patients (12%) with major CNS NP-SLE died. The annual mortality rate for patients with and without ever major CNS NP-SLE was 10.8% vs 3.8%, respectively. Individually, CVD (14%) and organic brain syndrome (15.5%) showed the highest mortality rates. The 10% mortality rate for patients with and without ever major CNS NP-SLE was reached after 12.3 vs 22.8 years, respectively. CVD (9.8 years) and organic brain syndrome (7.1 years) reached the 10% mortality rate earlier than other major CNS NP-SLE manifestations. Major CNS NP-SLE (HR 1.85, 1.29-2.67) and more specifically CVD (HR 2.17, 1.41-3.33) and organic brain syndrome (HR 2.11, 1.19-3.74) accounted as independent prognostic factors for poor survival. CONCLUSION: The presentation of major CNS NP-SLE during the disease course contributes to a higher mortality, which may differ depending on the individual NP manifestation. CVD and organic brain syndrome are associated with the highest mortality rates.


Assuntos
Lúpus Eritematoso Sistêmico , Vasculite Associada ao Lúpus do Sistema Nervoso Central , Reumatologia , Humanos , Estudos Retrospectivos , Lúpus Eritematoso Sistêmico/epidemiologia , Vasculite Associada ao Lúpus do Sistema Nervoso Central/complicações , Vasculite Associada ao Lúpus do Sistema Nervoso Central/epidemiologia , Vasculite Associada ao Lúpus do Sistema Nervoso Central/psicologia , Sistema Nervoso Central
5.
Phytochemistry ; 196: 113070, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34999511

RESUMO

Differences in phenolic composition across different ontogenic stages can be crucial in determining the interaction outcomes between plants and their surrounding biotic environment. In seagrasses, specific phenolic compounds have rarely been analyzed and remain unexplored in ontogenic stages other than non-reproductive adults. Furthermore, it is generally accepted that plants would prioritize defense (e.g., through increased phenolic content) on tissues or stages that are critical for plant fitness but how this affects nutritional quality or plant resources has been scarcely explored. We analyzed how phenolic composition, N and C content and carbohydrate resources varied among different life stages (i.e. old and young leaves of reproductive and non-reproductive plants, and leaves of seedlings) in the seagrass Posidonia oceanica. We identified five phenolic compounds, whose structures were established as hydroxycinnamate esters of tartaric acid. Also, our results show that in all examined ontogenic stages phenolic compounds have the same qualitative composition but inflorescences exhibit higher contents than vegetative tissues. We did not find a reduction in stored resources in reproductive plants, pointing to some kind of compensatory mechanism in the production or storage of resources. In contrast, seedlings seemed to have less phenolic compounds than reproductive plants, perhaps due to limited resources available to allocate to phenolic production. Our results demonstrate how different ontogenic stages change their investment in specialized phenolic compounds prioritizing different functions according to the needs and limitations of that stage.


Assuntos
Alismatales , Alismatales/química , Fenóis , Folhas de Planta , Plântula
6.
Funct Plant Biol ; 49(6): 517-532, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34372966

RESUMO

This study documents the first validation of the suitability of the most common parameters and protocols used in marine ecophysiology to characterise photosynthesis by means of chlorophyll a fluorescence tools. We demonstrate that the effective yield of PSII (ΔF /F m ') is significantly underestimated when using short inductions times (≤1 min) following the rapid light curve protocol (RLC). The consequent electron transport rates (ETR) underestimations are species-specific and highly variable with irradiance and the photoacclimatory condition of the sample. Our analysis also questions the use of relative descriptors (relETR), as they not only overestimate photosynthesis, but overlook one of the fundamental components of the photosynthetic response: light absorption regulation. Absorptance determinations were fundamental to characterise the ETR response of low-pigmented seagrass leaves, and also uncovered relevant differences between two coral species and the accclimatory response of a cultured dinoflagellate to temperature. ETR and oxygen evolution determinations showed close correlations for all organisms tested with the expected slope of 4 e- per O2 molecule evolved, when correct photosynthesis inductions and light absorption determinations were applied. However, ETR curves cannot be equated to conventional photosynthetic response to irradiance (P vs E ) curves, and caution is needed when using ETR to characterise photosynthesis rates above photosynthesis saturation (E k ). This validation strongly supports the utility of fluorescence tools, underlining the need to correct two decades of propagation of erroneous concepts, protocols and parameters in marine eco-physiology. We aim also to emphasise the importance of optical descriptions for understanding photosynthesis, and for interpreting fluorescence measurements. In combination with conventional gross photosynthesis (GPS) approaches, optical characterisations open an extraordinary opportunity to determine two central parameters of photosynthesis performance: the quantum yield (φmax ) of the process and its minimum quantum requirements (1/φmax ). The combination of both approaches potentiates the possibilities of chlorophyll a fluorescence tools to characterise marine photosynthesis biodiversity.


Assuntos
Clorofila , Luz , Clorofila A , Fluorescência , Oxigênio , Fotossíntese/fisiologia
7.
J Int Med Res ; 49(7): 3000605211029058, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34251275

RESUMO

OBJECTIVE: We aimed to assess the relationship between major air pollutants and the natural history and mortality of idiopathic pulmonary fibrosis (IPF). METHODS: We conducted a retrospective cohort study from 2013 to 2019 among 52 patients with IPF from the pneumology department of a tertiary hospital. According to their geocoded residential address, each patient was assigned a mean concentration of carbon monoxide (CO), nitrogen dioxide, particulate matter 2.5 and 10, ozone, and sulfur dioxide, as measured at a single surveillance station in central Madrid, Spain. We analyzed forced vital capacity (FVC), CO diffusing capacity, 6-minute walking test, degree of dyspnea, radiologic pattern, and signs of pulmonary hypertension in all patients. RESULTS: Patients' mean age was 66 ± 10 years, and 79% were men. The mean predicted FVC was 78.9 ± 0.5%. Forty-two patients met the criteria for severe disease, and 18 patients died. Mortality was significantly associated with increased CO exposure (for each 0.1 mg/m2 increase: odds ratio 2.45, 95% confidence interval 1.39-4.56). We observed no association between any of the other investigated contaminants and IPF mortality or severity. CONCLUSIONS: Air pollution, specifically that caused by carbon monoxide, can increase mortality in patients with IPF.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Fibrose Pulmonar Idiopática , Idoso , Poluentes Atmosféricos/toxicidade , Poluição do Ar/efeitos adversos , Poluição do Ar/análise , Humanos , Masculino , Pessoa de Meia-Idade , Material Particulado/efeitos adversos , Material Particulado/análise , Estudos Retrospectivos , Espanha/epidemiologia
8.
Reumatol. clín. (Barc.) ; 16(6): 480-484, nov.-dic. 2020. ilus, tab
Artigo em Espanhol | IBECS | ID: ibc-201051

RESUMO

OBJETIVOS: Analizar las características clínicas y de metabolismo óseo de una serie de pacientes con fracturas vertebrales tras la suspensión de denosumab (DMab). MÉTODOS: Estudio observacional retrospectivo de 10 pacientes con fracturas vertebrales tras suspender DMab atendidas en el Servicio de Reumatología de un hospital español de tercer nivel entre 2015 y 2018. RESULTADOS: Se registraron un total de 49 fracturas espontáneas tras una media de 6 dosis de DMab y transcurridos 10,9 meses desde la suspensión del fármaco. El 90% había recibido tratamiento previo, 7 de 10 bisfosfonatos orales. Tras la suspensión, CTX y P1NP estaban elevados y la media de T-score en cuello femoral y columna lumbar fue menor que previo a DMab. Las vértebras más afectadas fueron L3, L5, D6, D7, D9 y D11. CONCLUSIÓN: La descripción de nuevos casos de fracturas vertebrales múltiples en los meses posteriores a la suspensión de DMab subraya la preocupación emergente en la comunidad científica siendo preciso apoyar en evidencias sólidas las nuevas recomendaciones sobre su manejo


OBJECTIVES: Analyse clinical and bone metabolism features in a case series of patients with multiple vertebral fractures after discontinuation of denosumab (DMab). METHODS: An observational descriptive study analysing data from ten patients with multiple vertebral fractures after DMab discontinuation that were admitted to our rheumatology department between 2015 and 2018. RESULTS: There were a total of 49 spontaneous fractures after an average of 6 DMab doses and 10.9 months from discontinuation. Ninety percent had already received treatment other than DMab 7 of 10 oral bisphosphonates. After discontinuation, CTX and P1NP remained elevated and mean T-score for femoral neck and lumbar spine was lower than before treatment. The most affected vertebrae were L3, L5, D6, D7, D9 and D11. CONCLUSION: This report of ten new cases suffering multiple vertebral fractures early after discontinuation of DMab highlights the emerging concern on the subject in the scientific community and the need to clarify its pathogenic mechanism, and to support by solid evidence the new recommendations on its management


Assuntos
Humanos , Feminino , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Denosumab/uso terapêutico , Fraturas Múltiplas/etiologia , Fraturas por Osteoporose/epidemiologia , Fraturas da Coluna Vertebral/epidemiologia , Conservadores da Densidade Óssea/uso terapêutico , Suspensão de Tratamento , Estudos Retrospectivos , Efeito Rebote , Anticorpos Monoclonais Humanizados/uso terapêutico , Densitometria/métodos
9.
Mar Environ Res ; 162: 105159, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32992225

RESUMO

Seagrasses are key habitat-forming species of coastal areas. While previous research has demonstrated considerable small-scale variation in seagrass abundance and structure, studies teasing apart local from large-scale variation are scarce. We determined how different biogeographic scenarios, under varying environmental and genetic variation, explained variation in the abundance and structure (morphology and biomass allocation), epiphytes and sexual reproduction intensity of the seagrass Cymodocea nodosa. Regional and local-scale variation, including their temporal variability, contributed to differentially explain variation in seagrass attributes. Structural, in particular morphological, attributes of the seagrass leaf canopy, most evidenced regional seasonal variation. Allocation to belowground tissues was, however, mainly driven by local-scale variation. High seed densities were observed in meadows of large genetic diversity, indicative of sexual success, which likely resulted from the different evolutionary histories undergone by the seagrass at each region. Our results highlight that phenotypic plasticity to local and regional environments need to be considered to better manage and preserve seagrass meadows.


Assuntos
Alismatales , Biomassa , Ecossistema , Folhas de Planta , Reprodução
10.
Reumatol Clin (Engl Ed) ; 16(6): 480-484, 2020.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-30846260

RESUMO

OBJECTIVES: Analyse clinical and bone metabolism features in a case series of patients with multiple vertebral fractures after discontinuation of denosumab (DMab). METHODS: An observational descriptive study analysing data from ten patients with multiple vertebral fractures after DMab discontinuation that were admitted to our rheumatology department between 2015 and 2018. RESULTS: There were a total of 49 spontaneous fractures after an average of 6 DMab doses and 10.9 months from discontinuation. Ninety percent had already received treatment other than DMab 7 of 10 oral bisphosphonates. After discontinuation, CTX and P1NP remained elevated and mean T-score for femoral neck and lumbar spine was lower than before treatment. The most affected vertebrae were L3, L5, D6, D7, D9 and D11. CONCLUSION: This report of ten new cases suffering multiple vertebral fractures early after discontinuation of DMab highlights the emerging concern on the subject in the scientific community and the need to clarify its pathogenic mechanism, and to support by solid evidence the new recommendations on its management.


Assuntos
Conservadores da Densidade Óssea/administração & dosagem , Denosumab/administração & dosagem , Fraturas Múltiplas/etiologia , Fraturas da Coluna Vertebral/etiologia , Suspensão de Tratamento , Idoso , Feminino , Humanos , Pessoa de Meia-Idade
11.
Clin Exp Rheumatol ; 38(4): 662-669, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31694752

RESUMO

OBJECTIVES: To assess the plasma apolipoprotein B/apolipoprotein A1 ratio and its potential association with cardiovascular events (CVE) in patients with rheumatoid arthritis (RA). METHODS: A baseline analysis was made of the CARdiovascular in rheuMAtology Project (CARMA), a 10-year prospective study evaluating the presence of at least one CVE in 775 Spanish patients with RA. Of them, 29 had already experienced CVE prior to the inclusion in the study. We assessed the association between the elevation of the apoB/apoA1 ratio with the presence of CVE according to a logistic regression model for possible confounding factors. We also analysed the main parameters of activity of RA and parameters related to lipid metabolism. RA patients were classified according to treatment: patients treated with disease-modifying anti-rheumatic drugs without biologics and those undergoing biologic therapy (anti-TNF-α, anti-IL-6 receptor, and other biologic agents). RESULTS: The apoB/apoA1 ratio of patients who had experienced CVE was higher than that of patients without previous CVE (0.65 vs. 0.60). However, the difference between both subgroups did not reach statistical significance (p=0.197). It was also the case after the multivariate analysis [OR: 1.48 (95% CI: 0.15-14.4); p=0.735]. RA patients from the group with CVE were more commonly receiving lipid-lowering treatment with statins than those without CVE history (41.4% vs. 20%, p=0.005). High HAQ and high atherogenic index were significantly associated with the presence of CVE. There was no statistical association between the type of biologic therapy used in RA and the presence of CVE. CONCLUSIONS: No association between ApoB/apoA1 ratio and CVE was found at the baseline visit of patients with RA from the CARMA study.


Assuntos
Antirreumáticos/uso terapêutico , Artrite Reumatoide/tratamento farmacológico , Doenças Cardiovasculares , Apolipoproteína A-I , Apolipoproteínas B , Humanos , Estudos Prospectivos , Fator de Necrose Tumoral alfa/uso terapêutico
12.
Reumatol. clín. (Barc.) ; 15(6): e125-e127, nov.-dic. 2019. ilus
Artigo em Espanhol | IBECS | ID: ibc-189670

RESUMO

La enfermedad gonocócica diseminada es una manifestación infrecuente de la afectación por Neisseria gonorrhoeae, que presenta una clínica variada y no bien definida, siendo la afectación articular un hallazgo característico. Presentamos el caso de una mujer de 64 años con enfermedad gonocócica diseminada de inicio agudo, que comenzó con deterioro generalizado y oligoartritis. Se realizó artrocentesis de carpo, obteniéndose un líquido sinovial de aspecto purulento, cuyo estudio microbiológico identificó Neisseira gonorrhoeae. En el estudio se objetivó un complemento hemolítico total (CH50) de cero, no detectándose la fracción C2 del complemento. Son muy pocos los casos descritos en la literatura de enfermedad gonocócica diseminada asociada a déficit de C2. Presentamos un nuevo caso y revisamos los previamente publicados


Disseminated gonococcal infection is a rare presentation of the sexually transmitted pathogen, Neisseria gonorrhoeae. Here, we report the case of a 64-year-old woman with disseminated gonococcal infection, which started with symptoms of oligoarthritis and malaise. Neisseria gonorrhoeae was identified in the carpal synovial fluid. The follow-up study revealed an absence of total hemolytic complement and complement C2 was not detected. Being relatively common, C2 deficiency has been associated with disseminated gonococcal infection in a few cases. We present a new case and discuss those previously published


Assuntos
Humanos , Feminino , Pessoa de Meia-Idade , Artrite Infecciosa/microbiologia , Complemento C2/deficiência , Gonorreia/complicações
13.
Oecologia ; 189(3): 719-732, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30806786

RESUMO

Numerous hypotheses have been posited to explain the observed variation in plant defense strategies against herbivory. Under resource-rich environments, plants are predicted to increase their tolerance (limiting resource model; LRM) and, while the resource availability hypothesis (RAH) predicts a decrease in constitutive resistance in plant species growing in resource-rich environments, at the intraspecific level, plants are predicted to follow an opposite pattern (intraspecific RAH). Furthermore, the effect of multiple factors in modulating plant defense strategies has been scarcely explored and is more difficult to predict. Our aim was to understand how plant defense traits respond to herbivory, resource availability and their interactions, and to assess the effects on plant palatability. To this end, we performed an in situ factorial experiment at two sites simulating three herbivory levels and two nutrient availability conditions with the seagrass Posidonia oceanica. Additionally, we performed a series of feeding experiments with its two main herbivores. While plants decreased their constitutive resistance under nutrient fertilization (contrary to intraspecific RAH but in accordance to the RAH), and did not increase allocation to tolerance (likely due to resource limitation, LRM), simulated herbivory induced resistance traits. However, we found no interactive effects of nutrient fertilization and herbivory simulation on plant defense. Both herbivores responded similarly to changes in plant palatability, strongly preferring nutrient-enriched plants and non-clipped plants. This work highlights the need to better understand the drivers of plant defense intraspecific variability in response to resources, particularly in habitat-forming species where changes in plant traits and abundance will cascade onto associated species.


Assuntos
Alismatales , Herbivoria , Ecossistema , Fenótipo , Plantas
14.
Reumatol Clin (Engl Ed) ; 15(6): e125-e127, 2019.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-29102589

RESUMO

Disseminated gonococcal infection is a rare presentation of the sexually transmitted pathogen, Neisseria gonorrhoeae. Here, we report the case of a 64-year-old woman with disseminated gonococcal infection, which started with symptoms of oligoarthritis and malaise. Neisseria gonorrhoeae was identified in the carpal synovial fluid. The follow-up study revealed an absence of total hemolytic complement and complement C2 was not detected. Being relatively common, C2 deficiency has been associated with disseminated gonococcal infection in a few cases. We present a new case and discuss those previously published.


Assuntos
Artrite Infecciosa/microbiologia , Complemento C2/deficiência , Gonorreia/complicações , Feminino , Humanos , Pessoa de Meia-Idade
15.
Sci Total Environ ; 610-611: 1487-1495, 2018 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-28898957

RESUMO

Persistent organic pollutants (POPs) reach Antarctica through atmospheric transport, oceanic currents, and to minor extent, by migratory animals. The Southern Ocean is a net sink for many POPs, with a key contribution of the settling fluxes of POPs bound to organic matter (biological pump). However, little is known about POP transfer through the food web in the Southern Ocean and Antarctic waters, where krill is an important ecological node. In this study, we assessed the occurrence of polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs), polybrominated diphenyl ethers (PBDEs), and polychlorinated biphenyls (PCBs) in Antarctic krill (Euphausia superba) from the Bellingshausen, South Scotia and Weddell Seas around the Antarctic Peninsula. The concentrations of PCDD/Fs, PBDEs and PCBs in krill showed a large variability and the average were higher (generally within a factor 3) than those previously reported for eastern Antarctica. This result highlights regional differences related to atmospheric transport and deposition, and also probable regional sources due to human activities. Bioaccumulation and biomagnification factors for PCBs in krill were estimated using previously reported phytoplankton and seawater concentrations for this region. These suggested a near water-krill equilibrium for PCBs, which was not observed for water-phytoplankton partitioning. The estimated removal settling fluxes of PCBs due to the biological pump were several orders of magnitude higher than the estimated fluxes of PCBs transferred from phytoplankton to krill.


Assuntos
Monitoramento Ambiental , Euphausiacea/metabolismo , Cadeia Alimentar , Poluentes Químicos da Água/metabolismo , Animais , Regiões Antárticas , Dibenzofuranos Policlorados/metabolismo , Éteres Difenil Halogenados/metabolismo , Oceanos e Mares , Bifenilos Policlorados/metabolismo , Dibenzodioxinas Policloradas/metabolismo , Água do Mar
16.
Glob Chang Biol ; 23(11): 4530-4543, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28544549

RESUMO

Increases in seawater temperature are expected to have negative consequences for marine organisms. Beyond individual effects, species-specific differences in thermal tolerance are predicted to modify species interactions and increase the strength of top-down effects, particularly in plant-herbivore interactions. Shifts in trophic interactions will be especially important when affecting habitat-forming species such as seagrasses, as the consequences on their abundance will cascade throughout the food web. Seagrasses are a major component of coastal ecosystems offering important ecosystem services, but are threatened by multiple anthropogenic stressors, including warming. The mechanistic understanding of seagrass responses to warming at multiple scales of organization remains largely unexplored, especially in early-life stages such as seedlings. Yet, these early-life stages are critical for seagrass expansion processes and adaptation to climate change. In this study, we determined the effects of a 3 month experimental exposure to present and predicted mean summer SST of the Mediterranean Sea (25°C, 27°C, and 29°C) on the photophysiology, size, and ecology (i.e., plant-herbivore interactions) of seedlings of the seagrass Posidonia oceanica. Warming resulted in increased mortality, leaf necrosis, and respiration as well as lower carbohydrate reserves in the seed, the main storage organ in seedlings. Aboveground biomass and root growth were also limited with warming, which could hamper seedling establishment success. Furthermore, warming increased the susceptibility to consumption by grazers, likely due to lower leaf fiber content and thickness. Our results indicate that warming will negatively affect seagrass seedlings through multiple direct and indirect pathways: increased stress, reduced establishment potential, lower storage of carbohydrate reserves, and increased susceptibly to consumption. This work provides a significant step forward in understanding the major mechanisms that will drive the capacity of seagrass seedlings to adapt and survive to warming, highlighting the potential additive effects that herbivory will have on ultimately determining seedling success.


Assuntos
Alismatales/fisiologia , Mudança Climática , Herbivoria , Plântula , Aclimatação , Biomassa , Ecossistema , Cadeia Alimentar , Mar Mediterrâneo , Folhas de Planta/crescimento & desenvolvimento , Estações do Ano , Água do Mar , Temperatura
17.
Sci Rep ; 6: 38017, 2016 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-27905514

RESUMO

Under future increased CO2 concentrations, seagrasses are predicted to perform better as a result of increased photosynthesis, but the effects in carbon balance and growth are unclear and remain unexplored for early life stages such as seedlings, which allow plant dispersal and provide the potential for adaptation under changing environmental conditions. Furthermore, the outcome of the concomitant biochemical changes in plant-herbivore interactions has been poorly studied, yet may have important implications in plant communities. In this study we determined the effects of experimental exposure to current and future predicted CO2 concentrations on the physiology, size and defense strategies against herbivory in the earliest life stage of the Mediterranean seagrass Posidonia oceanica. The photosynthetic performance of seedlings, assessed by fluorescence, improved under increased pCO2 conditions after 60 days, although these differences disappeared after 90 days. Furthermore, these plants exhibited bigger seeds and higher carbon storage in belowground tissues, having thus more resources to tolerate and recover from stressors. Of the several herbivory resistance traits measured, plants under high pCO2 conditions had a lower leaf N content but higher sucrose. These seedlings were preferred by herbivorous sea urchins in feeding trials, which could potentially counteract some of the positive effects observed.


Assuntos
Alismatales/fisiologia , Dióxido de Carbono/análise , Plântula/fisiologia , Adaptação Fisiológica , Alismatales/química , Animais , Herbivoria , Fotossíntese , Plântula/química
18.
Glob Chang Biol ; 21(11): 4021-30, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26152761

RESUMO

Coastal communities are under threat from many and often co-occurring local (e.g., pollution, eutrophication) and global stressors (e.g., climate change), yet understanding the interactive and cumulative impacts of multiple stressors in ecosystem function is far from being accomplished. Ecological redundancy may be key for ecosystem resilience, but there are still many gaps in our understanding of interspecific differences within a functional group, particularly regarding response diversity, that is, whether members of a functional group respond equally or differently to anthropogenic stressors. Herbivores are critical in determining plant community structure and the transfer of energy up the food web. Human disturbances may alter the ecological role of herbivory by modifying the defense strategies of plants and thus the feeding patterns and performance of herbivores. We conducted a suite of experiments to examine the independent and interactive effects of anthropogenic (nutrient and CO2 additions) and natural (simulated herbivory) disturbances on a seagrass and its interaction with two common generalist consumers to understand how multiple disturbances can impact both a foundation species and a key ecological function (herbivory) and to assess the potential existence of response diversity to anthropogenic and natural changes in these systems. While all three disturbances modified seagrass defense traits, there were contrasting responses of herbivores to such plant changes. Both CO2 and nutrient additions influenced herbivore feeding behavior, yet while sea urchins preferred nutrient-enriched seagrass tissue (regardless of other experimental treatments), isopods were deterred by these same plant tissues. In contrast, carbon enrichment deterred sea urchins and attracted isopods, while simulated herbivory only influenced isopod feeding choice. These contrasting responses of herbivores to disturbance-induced changes in seagrass help to better understand the ecological functioning of seagrass ecosystems in the face of human disturbances and may have important implications regarding the resilience and conservation of these threatened ecosystems.


Assuntos
Alismatales/fisiologia , Dióxido de Carbono/metabolismo , Eutrofização , Herbivoria , Invertebrados/fisiologia , Animais , Cadeia Alimentar , Portugal
19.
Environ Sci Technol ; 48(17): 10198-207, 2014 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-25083749

RESUMO

The remote oceans are among the most pristine environments in the world, away from sources of anthropogenic persistent organic pollutants (POP), but nevertheless recipients of atmospheric deposition of POPs that have undergone long-range atmospheric transport (LRAT). In this work, the background occurrence of gas and aerosol phase polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin like polychlorinated biphenyls (dl-PCB) is evaluated for the first time in the atmosphere of the tropical and subtropical Atlantic, Pacific, and Indian oceans. Thirty-nine air samples were collected during the eight-month Malaspina circumnavigation cruise onboard the R/V Hespérides. The background levels of dioxins and dl-PCBs remained very low and in many cases very close to or below the limit of detection. Expectedly, the levels of PCBs were higher than dioxins, PCB#118 being the most abundant compound. In the particular case of dioxins, octachlorodibenzo-p-dioxin (OCDD) was the most abundant PCDD/F congener. Distribution of dl-PCB is dominated by the gas phase, while for PCDD/F the aerosol phase concentrations were higher, particularly for the more hydrophobic congeners. The Atlantic Ocean presented on average the highest PCDD/F and dl-PCB concentrations, being lower in the southern hemisphere. The assessment of air mass back trajectories show a clear influence of continental source regions, and lower concentrations when the air mass has an oceanic origin. In addition, the samples affected by an oceanic air mass are characterized by a lower contribution of the less chlorinated dioxins in comparison with the furans, consistent with the reported higher reaction rate constants of dibenzo-p-dioxins with OH radicals than those of dibenzofurans. The total dry atmospheric deposition of aerosol-bound ∑PCDD/F and ∑dl-PCB to the global oceans was estimated to be 354 and 896 kg/year, respectively.


Assuntos
Poluentes Atmosféricos/análise , Atmosfera/química , Benzofuranos/análise , Compostos de Bifenilo/análise , Oceanos e Mares , Dibenzodioxinas Policloradas/análogos & derivados , Aerossóis/análise , Ar/análise , Oceano Atlântico , Gases/análise , Geografia , Oceano Índico , Oceano Pacífico , Dibenzodioxinas Policloradas/análise , Navios
20.
Arch. bronconeumol. (Ed. impr.) ; 49(6): 249-260, jun. 2013. tab
Artigo em Espanhol | IBECS | ID: ibc-113109

RESUMO

Las enfermedades del colágeno constituyen un gran grupo de enfermedades inflamatorias sistémicas de etiología autoinmune. La etiopatogenia de las enfermedades del colágeno es multifactorial. Existe una susceptibilidad genética, y muchos trastornos del tejido conectivo muestran una agregación familiar, sobre la que actúan factores ambientales que desencadenan la enfermedad. En las enfermedades del colágeno se pueden afectar casi todos los órganos del cuerpo. El sistema respiratorio es uno de los más frecuentemente afectados, aunque no se conoce con exactitud la prevalencia de enfermedad pulmonar en las diferentes enfermedades del colágeno. Cualquier estructura del aparato respiratorio puede estar afectada. Quizá lo más frecuente sea la enfermedad del parénquima pulmonar en forma de neumonitis, que puede manifestarse como cualquiera de los patrones de neumonitis intersticiales idiopáticas. Pero también pueden afectarse la pleura, los vasos pulmonares, la vía aérea y la musculatura respiratoria. La frecuencia de enfermedad pulmonar asociada a las enfermedades del colágeno está aumentando, por una parte gracias a los mejores métodos de diagnóstico de que disponemos hoy en día, como la tomografía computarizada de alta resolución, y también por la aparición de nuevas formas de neumonitis asociadas a los nuevos tratamientos empleados en la actualidad. El objetivo de este artículo es ofrecer una visión en conjunto de cómo las enfermedades del colágeno pueden afectar el pulmón, de acuerdo con las nuevas evidencias científicas (AU)


Collagen diseases are a large group of systemic inflammatory diseases of autoimmune etiology. The etiopathogenesis of collagen diseases is multifactorial. There is genetic susceptibility, as many connective tissue disorders show family history, and environmental factors may trigger the disease. Collagen diseases can affect almost all the organs of the body. The respiratory system is one of the most frequently affected, although the prevalence of pulmonary disease is not precisely known for the different collagen disorders. Any structure of the respiratory tract can be affected, but perhaps the most frequent is pulmonary parenchymal disease in the form of pneumonitis, which can be produced in any of the idiopathic interstitial pneumonitis patterns. The pleura, pulmonary vessels, airways and respiratory muscles may also be affected. The frequency of lung disease associated with collagen diseases is on the rise. This is in due part to the better diagnostic methods that are available to us today (such as high-resolution computed tomography) and also to the appearance of new forms of pneumonitis associated with the new treatments that are currently used. The objective of this article is to offer a global vision of how collagen diseases can affect the lungs according to the latest scientific evidence (AU)


Assuntos
Humanos , Doenças do Colágeno/complicações , Doenças Pulmonares Intersticiais/complicações , Artrite Reumatoide/complicações , Escleroderma Sistêmico/complicações , Lúpus Eritematoso Sistêmico/complicações , Miosite/complicações , Doenças do Tecido Conjuntivo/complicações
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