RESUMEN
An increase of nitrogen deposition resulting from human activities is not only a major threat for global biodiversity, but also for human health, especially in highly populated regions. It is thus important and in some instances legally mandated to monitor reactive nitrogen species in the atmosphere. The utilization of widely distributed biological species suitable for biomonitoring may be a good alternative. We assessed the suitability of an ensemble of atmospheric biomonitors of nitrogen deposition by means of an extensive sampling of a lichen, two mosses, and a bromeliad throughout the Valley of Mexico, whose population reaches 30 million, and subsequent measurements of nitrogen metabolism parameters. In all cases we found significant responses of nitrogen content, C:N ratio and the δ15N to season and site. In turn, the δ15N for the mosses responded linearly to the wet deposition. Also, the nitrogen content (R2 = 0.7), the C:N ratio (R2 = 0.6), and δ15N (R2 = 0.5) for the bromeliad had a linear response to NOx. However, the bromeliad was not found in sites with NOx concentrations exceeding 80 ppb, apparently of as a consequence of excess nitrogen. These biomonitors can be utilized in tandem to determine the status of atmospheric nitrogenous pollution in regions without monitoring networks for avoiding health problems for ecosystems and humans.
Asunto(s)
Contaminantes Atmosféricos/análisis , Bromelia/química , Briófitas/química , Monitoreo del Ambiente/métodos , Líquenes/química , Nitrógeno/análisis , Contaminantes Atmosféricos/metabolismo , Atmósfera , Bromelia/metabolismo , Briófitas/metabolismo , Humanos , Líquenes/metabolismo , México , Nitrógeno/metabolismo , Fijación del Nitrógeno/fisiología , Isótopos de Nitrógeno , Especies de Nitrógeno Reactivo/análisisRESUMEN
Electronic paramagnetic resonance (EPR) is an appropriate tool to identify free radicals formed in tissues under normal as well as stressful conditions. Since nitric oxide (NO) as a free radical has paramagnetic properties it can be detected by EPR. The use of spin traps highly improves the sensitivity allowing NO identification, detection and quantification at room temperature in vitro and in vivo conditions. NO production in animals is almost exclusively associated to an enzyme family known as Nitric Oxide Synthases (NOSs). The digestive glands of mollusks are a major target for oxidative disruption related to environmental stress. A simple EPR-methodology to asses both, the presence of NO and its rate of generation in tissues from different mollusk species, is reported here.
Asunto(s)
Espectroscopía de Resonancia por Spin del Electrón , Moluscos/metabolismo , Óxido Nítrico/análisis , Animales , Oxidación-Reducción , Estrés Oxidativo , Especies de Nitrógeno Reactivo/análisis , Especies Reactivas de Oxígeno/análisisRESUMEN
Leukocytes play a central role in asthma physiopathology. Aerobic training (AT) reduces leukocytes recruitment to the airways, but the effects of AT on some aspects of leukocytes activation in asthma are unknown. Therefore, the effects of 4 weeks of AT on airway inflammation, pulmonary and systemic Th2 cytokines levels, leukocytes expression of pro and anti-inflammatory, pro-fibrotic, oxidants and anti-oxidants mediators in an experimental model of asthma was investigated. AT reduced the levels of IL-4, IL-5, IL-13 in bronchoalveolar lavage fluid (BALF) (p<0.001), serum levels of IL-5, while increased BALF and serum levels of IL-10 (p<0.001). In addition, AT reduced leukocytes activation, showed through decreased expression of Th2 cytokines (IL-4, IL-5, IL-13; p<0.001), chemokines (CCL5, CCL10; p<0.001), adhesion molecules (VCAM-1, ICAM-1; p<0.05), reactive oxygen and nitrogen species (GP91phox and 3-nitrotyrosine; p<0.001), inducible nitric oxide synthase (iNOS; p<0.001), nuclear factor kB (NF-kB; p<0.001) while increased the expression of anti-inflammatory cytokine (IL-10; p<0.001). AT also decreased the expression of growth factors (TGF-beta, IGF-1, VEGF and EGFr; p<0.001). We conclude that AT reduces the activation of peribronchial leukocytes in a mouse model of allergic asthma, resulting in decreased airway inflammation and Th2 response.
Asunto(s)
Asma/inmunología , Bronquios/inmunología , Leucocitos/fisiología , Condicionamiento Físico Animal , Animales , Líquido del Lavado Bronquioalveolar/química , Moléculas de Adhesión Celular/análisis , Quimiocinas/análisis , Citocinas/análisis , Modelos Animales de Enfermedad , Inflamación/inmunología , Péptidos y Proteínas de Señalización Intercelular/análisis , Ratones , Ratones Endogámicos BALB C , FN-kappa B/análisis , Especies de Nitrógeno Reactivo/análisis , Especies Reactivas de Oxígeno/análisis , Células TH1/inmunología , Células Th2/inmunologíaRESUMEN
Increased reactive nitrogen (Nr) deposition due to expansion of agro-industry was investigated considering emission sources, atmospheric transport and chemical reactions. Measurements of the main inorganic nitrogen species (NO2, NH3, HNO3, and aerosol nitrate and ammonium) were made over a period of one year at six sites distributed across an area of â¼130,000 km2 in southeast Brazil. Oxidized species were estimated to account for â¼90% of dry deposited Nr, due to the region's large emissions of nitrogen oxides from biomass burning and road transport. NO2-N was important closer to urban areas, however overall HNO3-N represented the largest component of dry deposited Nr. A simple mathematical modeling procedure was developed to enable estimates of total Nr dry deposition to be made from knowledge of NO2 concentrations. The technique, whose accuracy here ranged from <1% to 29%, provides a useful new tool for the mapping of reactive nitrogen deposition.
Asunto(s)
Contaminantes Atmosféricos/análisis , Modelos Químicos , Especies de Nitrógeno Reactivo/análisis , Aerosoles , Agricultura , Brasil , Industrias , Estaciones del AñoRESUMEN
AIM: To assess the influence of co-culture with mineral trioxide aggregate (MTA) on phagocytosis and the production of reactive oxygen intermediates (ROI) and nitrogen (NO) species and the arginase activity by M1 and M2 peritoneal macrophages. METHODOLOGY: Cellular viability, adherence and phagocytosis of Saccharomyces boulardii were assayed in the presence of MTA. Macrophages were stimulated with zymosan for ROI assays and with Fusobacterium nucleatum and Peptostreptococcus anaerobius and IFN-gamma for NO production and arginase activity, when in contact with capillaries containing MTA. Data were analysed by T, anova, Kruskall-Wallis and Mann-Whitney tests. RESULTS: M2 macrophages displayed greater cellular viability in polypropylene tubes, greater ability to ingest yeast and smaller production of ROI and higher arginase activity when compared with M1 macrophages. Both macrophages, M1 and M2, presented similar cell adherence and NO production. The addition of bacterial preparations to macrophages interfered with NO and arginase productions. MTA did not interfere with any of the parameters measured. CONCLUSIONS: Phagocytosis and the ability of the two macrophage subtypes to eliminate microbes were not affected by MTA.
Asunto(s)
Compuestos de Aluminio/farmacología , Compuestos de Calcio/farmacología , Óxidos/farmacología , Fagocitosis/efectos de los fármacos , Materiales de Obturación del Conducto Radicular/farmacología , Silicatos/farmacología , Animales , Arginasa/efectos de los fármacos , Combinación de Medicamentos , Femenino , Macrófagos/citología , Macrófagos/efectos de los fármacos , Masculino , Ratones , Ratones Endogámicos C57BL , Especies de Nitrógeno Reactivo/análisis , Especies Reactivas de Oxígeno/análisisRESUMEN
Uma excessiva produção de espécies reativas pode ser prejudicial, superando a capacidade antioxidante e conduzindo a um desequilíbrio redox. A maioria das evidências da formação de espécies reativas em células musculares são "indiretas", ao passo que as evidências "diretas" ainda são escassas. As razões para este fato são múltiplas. Esta revisão sugere a utilização de sondas fluorescentes como DCFH (reativa ao H2O2), DAF-2 (reativa ao NO) e fluoróforo nitróxido (reativa ao O2À-) para determinação dessas espécies. Em adição, o presente estudo sugere que: 1) as medidas "indiretas" de ataque oxidativo em amostras sangüíneas não necessariamente refletem o ataque oxidativo ocorrido nas células musculares; 2) amostras de músculos isolados e homogenatos podem apresentar uma grande quantidade de tecido vascular contendo células endoteliais, hemácias e leucócitos, os quais podem gerar EROs e NO, dificultando a interpretação dos resultados; 3) as sondas fluorescentes DCFH-DA/DCFH, DAF-2-DA/DAF-2 e nitróxido são sensíveis na detecção do H2O2, NO e O2À- respectivamente, em tecido muscular durante contrações; 4) como método alternativo no estudo da produção de EROs e NO em músculo esquelético, culturas de células musculares e fibra muscular isolada são indicados como modelos experimentais.
Asunto(s)
Animales , Humanos , Músculo Esquelético/química , Músculo Esquelético/citología , Especies de Nitrógeno Reactivo/análisis , Especies Reactivas de Oxígeno/análisis , Contracción Muscular , Músculo Esquelético/fisiologíaRESUMEN
An excessive level of these species may be harmful as it may overcome the antioxidant capacity. Most evidences for ROS and NO formation in muscle cell are indirect whereas direct evidences are scarce. The present review suggests as an alternative method either fluorescent DCFH, DAF-2 or fluorescamine toward H2O2, NO and O2*- measurements, respectively in muscle cell. In addition, it was concluded that: 1) the "indirect" measurements of ROS and NO in blood sample do not reflect oxidative attack occurred in muscle cells during contractions; 2) isolated muscles and homogenates may contain a large amount of endothelial cells, red blood cells and leukocytes which may generate ROS and NO; 3) the fluorescent DCFH-DA/DCFH, DAF-2-DA/DAF-2 and fluorescamine are sensitive in detection of H2O2, NO and O2.- respectively, in muscle cell during contractions; 4) muscle cell culture and isolated muscle fiber are indicated as experimental models to study ROS and NO formation in muscular tissue.