Acute respiratory infection (ARI) is a leading cause of morbidity and mortality in children worldwide. This study aimed to determine the viral and atypical bacterial causes of different severities ...and clinical manifestations of ARI in preschool children from low-income families in North-East Brazil.
Clinical/demographic data and nasopharyngeal aspirates (NPA) were prospectively collected from children <5 years presenting with ARI over one year to a paediatric A&E department. Disease severity was grouped according to presence of lower respiratory tract signs, need for hospital admission and need for oxygen. Clinical manifestation of ARI was based on discharge diagnosis from hospital with four conditions predominating: bronchiolitis, pneumonia, episodic viral wheeze/asthma and upper respiratory tract infection. Multiplex PCR was used to detect 17 common respiratory viral and atypical bacterial pathogens in NPA.
407 children with a median age of eight months were recruited. Pathogens were detected in 85·5% samples with co-infection being particularly common (39·5%). Respiratory Syncytial Virus (RSV; 37%), Adenoviruses (AdV; 25%), Rhinoviruses (hRV; 19%), Bocavirus (hBoV; 19%), human Meta-pneumovirus (hMPV; 10%) and Mycoplasma pneumoniae (Mpp; 10%) were most prevalent. Detection and co-infection rates were similar in all severities and clinical manifestations of ARI apart from RSV, which was associated with more severe disease and specifically more severe cases of bronchiolitis, and Mpp, which was associated with more severe cases of pneumonia. Mpp was detected in 17% of children admitted to hospital with pneumonia.
This study underlines the importance of viral and atypical bacterial pathogens in ARI in pre-school children and highlights the complex epidemiology of these pathogens in this age group. Generally, viruses and atypical bacteria were detected in all severities and clinical manifestations of ARI but RSV and Mpp were associated with more severe cases of bronchiolitis and pneumonia respectively.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Toxicity of cadmium in musculoskeletal diseases Reyes-Hinojosa, D.; Lozada-Pérez, C.A.; Zamudio Cuevas, Y. ...
Environmental toxicology and pharmacology,
November 2019, 2019-Nov, 2019-11-00, 20191101, Letnik:
72
Journal Article
Recenzirano
Epidemiological studies have reported that exposure to toxic metals like cadmium (Cd) may promote the development of musculoskeletal diseases, such as osteoporosis, rheumatoid arthritis (RA), and ...osteoarthritis (OA), among others. The objective of this review is to summarize the molecular mechanisms of inflammation and oxidative stress activated by Cd at the bone level, particularly in osteoporosis, RA, and OA. Cadmium can increase bone resorption, affect the activity of osteoclasts and calcium (Ca) absorption, and impair kidney function, which favors the development of osteoporosis. In the case of RA, Cd interferes with the activity of antioxidant proteins, like superoxide dismutase (SOD) and catalase (CAT). It also promotes an inflammatory state, inducing the process of citrullination, which affects the proteins of immune response. On the other hand, accumulation of Cd in the tissues and blood of smokers has been related to the development of some musculoskeletal diseases. Therefore, knowing the negative impact of Cd toxicity at the articular level can help understand the damage mechanisms it produces, leading to the development of such diseases.
Emitted mainly by the oceans, iodine is a halogen compound important for atmospheric chemistry due to its high ozone depletion potential and effect on the oxidizing capacity of the atmosphere. Here ...we present a comprehensive data set of iodine oxide (IO) measurements in the open marine boundary layer (MBL) made during the Malaspina 2010 circumnavigation. Results show IO mixing ratios ranging from 0.4 to 1 pmol mol-1 (30% uncertainty) and, complemented with additional field campaigns, this data set confirms through observations the ubiquitous presence of reactive iodine chemistry in the global marine environment. We use a global model with organic (CH3I, CH2ICl, CH2I2 and CH2IBr) and inorganic (HOI and I2) iodine ocean emissions to investigate the contribution of the different iodine source gases to the budget of IO in the global MBL. In agreement with previous estimates, our results indicate that, globally averaged, the abiotic precursors contribute about 75 % to the IO budget. However, this work reveals a strong geographical pattern in the contribution of organic vs. inorganic precursors to reactive iodine in the global MBL.
Excess reactive oxygen species production by mitochondria is a key mechanism of age-related vascular dysfunction. Our laboratory has shown that supplementation with the mitochondrial-targeted ...antioxidant MitoQ improves vascular endothelial function by reducing mitochondrial reactive oxygen species and ameliorates arterial stiffening in old mice, but the effects in humans are unknown. Here, we sought to translate our preclinical findings to humans and determine the safety and efficacy of MitoQ. Twenty healthy older adults (60–79 years) with impaired endothelial function (brachial artery flow–mediated dilation <6%) underwent 6 weeks of oral supplementation with MitoQ (20 mg/d) or placebo in a randomized, placebo-controlled, double-blind, crossover design study. MitoQ was well tolerated, and plasma MitoQ was higher after the treatment versus placebo period (P<0.05). Brachial artery flow–mediated dilation was 42% higher after MitoQ versus placebo (P<0.05); the improvement was associated with amelioration of mitochondrial reactive oxygen species–related suppression of endothelial function (assessed as the increase in flow-mediated dilation with acute, supratherapeutic MitoQ 160 mg administration; n=9; P<0.05). Aortic stiffness (carotid–femoral pulse wave velocity) was lower after MitoQ versus placebo (P<0.05) in participants with elevated baseline levels (carotid–femoral pulse wave velocity >7.60 m/s; n=11). Plasma oxidized LDL (low-density lipoprotein), a marker of oxidative stress, also was lower after MitoQ versus placebo (P<0.05). Participant characteristics, endothelium-independent dilation (sublingual nitroglycerin), and circulating markers of inflammation were not different (all P>0.1). These findings in humans extend earlier preclinical observations and suggest that MitoQ and other therapeutic strategies targeting mitochondrial reactive oxygen species may hold promise for treating age-related vascular dysfunction.
CLINICAL TRIAL REGISTRATION—URLhttp://www.clinicaltrials.gov. Unique identifierNCT02597023.
Injection of iodine to the stratosphere Saiz-Lopez, A.; Baidar, S.; Cuevas, C. A. ...
Geophysical research letters,
28 August 2015, Letnik:
42, Številka:
16
Journal Article
Recenzirano
Odprti dostop
We report a new estimation of the injection of iodine into the stratosphere based on novel daytime (solar zenith angle < 45°) aircraft observations in the tropical tropopause layer and a global ...atmospheric model with the most recent knowledge about iodine photochemistry. The results indicate that significant levels of total reactive iodine (0.25–0.7 parts per trillion by volume), between 2 and 5 times larger than the accepted upper limits, can be injected into the stratosphere via tropical convective outflow. At these iodine levels, modeled iodine catalytic cycles account for up to 30% of the contemporary ozone loss in the tropical lower stratosphere and can exert a stratospheric ozone depletion potential equivalent to, or even larger than, that of very short‐lived bromocarbons. Therefore, we suggest that iodine sources and chemistry need to be considered in assessments of the historical and future evolution of the stratospheric ozone layer.
Key Points
Injection of iodine to the stratosphere can be 2 to 5 times larger than accepted upper limits
Iodine catalytic cycles could account for up to 30% of ozone loss in the tropical lower stratosphere
Iodine‐mediated depletion of stratospheric ozone can be comparable to that of VSL bromocarbons
Until recently, the Arctic Basin was generally considered to be a low productivity area and was afforded little attention in global- or even basin-scale ecosystem modelling studies. Due to ...anthropogenic climate change however, the sea ice cover of the Arctic Ocean is undergoing an unexpectedly fast retreat, exposing increasingly large areas of the basin to sunlight. As indicated by existing Arctic phenomena such as ice-edge blooms, this decline in sea-ice is liable to encourage pronounced growth of phytoplankton in summer and poses pressing questions concerning the future of Arctic ecosystems. It thus provides a strong impetus to modelling of this region. The Arctic Ocean is an area where plankton productivity is heavily influenced by physical factors. As these factors are strongly responding to climate change, we analyse here the results from simulations of the 1/4° resolution global ocean NEMO (Nucleus for European Modelling of the Ocean) model coupled with the MEDUSA (Model for Ecosystem Dynamics, carbon Utilisation, Sequestration and Acidification) biogeochemical model, with a particular focus on the Arctic basin. Simulated productivity is consistent with the limited observations for the Arctic, with significant production occurring both under the sea-ice and at the thermocline, locations that are difficult to sample in the field. Results also indicate that a substantial fraction of the variability in Arctic primary production can be explained by two key physical factors: (i) the maximum penetration of winter mixing, which determines the amount of nutrients available for summer primary production, and (ii) short-wave radiation at the ocean surface, which controls the magnitude of phytoplankton blooms. A strong empirical correlation was found in the model output between primary production and these two factors, highlighting the importance of physical processes in the Arctic Ocean.
During the East Antarctic International Ice Sheet Traverse (Eaiist, december 2019), in an unexplored part of the East Antarctic Plateau, snow samples were collected to expand our knowledge of the ...latitudinal variability of iodine, bromine and sodium as well as their relation in connection with emission processes and photochemical activation in this unexplored area. A total of 32 surface (0–5 cm) and 32 bulk (average of 1 m depth) samples were taken and analysed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Our results show that there is no relevant latitudinal trend for bromine and sodium. For bromine they also show that it has no significant post-depositional mechanisms while its inland surface snow concentration is influenced by spring coastal bromine explosions. Iodine concentrations are several orders of magnitude lower than bromine and sodium and they show a decreasing trend in the surface samples concentration moving southward. This suggests that other processes affect its accumulation in surface snow, probably related to the radial reduction in the ozone layer moving towards central Antarctica. Even though all iodine, bromine and sodium present similar long-range transport from the dominant coastal Antarctic sources, the annual seasonal cycle of the ozone hole over Antarctica increases the amount of UV radiation (in the 280–320 nm range) reaching the surface, thereby affecting the surface snow photoactivation of iodine. A comparison between the bulk and surface samples supports the conclusion that iodine undergoes spring and summer snow recycling that increases its atmospheric lifetime, while it tends to accumulate during the winter months when photochemistry ceases.
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•Halogens snow concentrations in an unexplored Antarctic region.•Spring bromine explosions and sodium and iodine winter accumulation in the East Antarctic Plateau.•Role of photochemistry in surface snow concentration and spatial distribution of photoactive elements.•Iodine decreasing latitudinal trend in surface snow linked with its photochemistry.
Three years of multi-axis differential optical absorption spectroscopy (MAXDOAS) measurements (2011-2013) have been used for estimating the NO2 mixing ratio along a horizontal line of sight from the ...high mountain subtropical observatory of Izana, at 2370 m a.s.l. (NDACC station, 28.3 degree N, 16.5 degree W). The method is based on horizontal path calculation from the O2-O2 collisional complex at the 477 nm absorption band which is measured simultaneously to the NO2 column density, and is applicable under low aerosol-loading conditions. The MAXDOAS technique, applied in horizontal mode in the free troposphere, minimizes the impact of the NO2 contamination resulting from the arrival of marine boundary layer (MBL) air masses from thermally forced upwelling breeze during middle hours of the day. Comparisons with in situ observations show that during most of the measuring period, the MAXDOAS is insensitive or very slightly sensitive to the upwelling breeze. Exceptions are found for pollution events during southern wind conditions. On these occasions, evidence of fast, efficient and irreversible transport from the surface to the free troposphere is found. Background NO2 volume mixing ratio (vmr), representative of the remote free troposphere, is in the range of 20-45 pptv. The observed seasonal evolution shows an annual wave where the peak is in phase with the solar radiation. Model simulations with the chemistry-climate CAM-Chem model are in good agreement with the NO2 measurements, and are used to further investigate the possible drivers of the NO2 seasonality observed at Izana.
We report the evolution of tropospheric NO2 over the south-east of the Iberian Peninsula from 2005 to 2017. We have used hourly NO2 levels measured at air-quality stations in urban and suburban ...environments. Annual averages ranged between 14 and 45 μg m−3, with peaks above 200 μg m−3. A monthly variation was observed, with higher concentrations in cold months (40–60 μg m−3) and lower levels in the warm season (13–17 μg m−3). A diurnal pattern was found in urban and suburban areas. The upward trend in NO2 observed during the whole period contrasts with the upward trend reported in 2013–2017. The NO2 tropospheric column levels measured by the Ozone Monitoring Instrument over the Iberian Peninsula indicated a similar behaviour; nevertheless, the largest Spanish metropolitan areas did not show this increase. The mean sea level pressure and wind field data of ERA5 (European Centre for Medium-Range Weather Forecasts) were used to investigate the weather conditions, the NO2 outputs of the Copernicus Monitoring Services being used for the assessment of the NO2 spatial distribution. NO2 regional events, with concentrations in the range 140–150 μg m−3, and which occurred both in the winter and summer season under anticyclonic conditions, are also described. A local origin is identified in winter, whereas in summer, they are associated with a high-pressure system that blocks Mediterranean outflows towards the Atlantic Ocean. The high NO2 levels are attributed mainly to two factors: i) local emissions, rather than contributions from the western Mediterranean (or even North Africa), and ii) an increase in the pressure gradient between the Atlantic and the Mediterranean pressure systems, associated with a decrease in wind speed, was found during the last five years compared with the previous eight. Meteorological and chemical changes in mid-latitudes associated with global warming should also be investigated in the future.
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•NO2 measurements from 2005 to 2017 were investigated in the SE of the Iberian Peninsula.•Negative NO2 trends were found in 2005–2017; however, an increase was measured from 2013 onwards.•Trend of NO2 on the surface showed good agreement with OMI NO2 tropospheric column trends.•NO2 events occurred in both winter and summer under a weak pressure gradient.•The change in NO2 trends could be associated with changes in weather patterns.
In this work, it is presented a first approach of a mathematical and kinetic analysis for improving the decoloration and further degradation process of an azo dye named acid red 27 (AR27), by means ...of a novel microbial consortium formed by the fungus Trametes versicolor and the bacterium Pseudomonas putida. A multivariate analysis was carried out by simulating scenarios with different operating conditions and developing a specific mathematical model based on kinetic equations describing all stages of the biological process, from microbial growth and substrate consuming to decoloration and degradation of intermediate compounds. Additionally, a sensitivity analysis was performed by using a factorial design and the Response Surface Method (RSM), for determining individual and interactive effects of variables like, initial glucose concentration, initial dye concentration and the moment in time for bacterial inoculation, on response variables assessed in terms of the minimum time for: full decoloration of AR27 (R1 = 2.375 days); maximum production of aromatic metabolites (R2 = 1.575 days); and full depletion of aromatic metabolites (R3 = 12.9 days). Using RSM the following conditions improved the biological process, being: an initial glucose concentration of 20 g l-1, an initial AR27 concentration of 0.2 g l-1 and an inoculation moment in time of P. putida at day 1. The mathematical model is a feasible tool for describing AR27 decoloration and its further degradation by the microbial consortium of T. versicolor and P. putida, this model will also work as a mathematical basis for designing novel bio-reaction systems than can operate with the same principle of the described consortium.
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