Reference Ranges of 8-Isoprostane Concentrations in Exhaled Breath Condensate (EBC): A Systematic Review and Meta-Analysis.

Isoprostanes are physiopathologic mediators of oxidative stress, resulting in lipid peroxidation. 8-isoprostane seems particularly useful for measuring oxidative stress damage. However, no reference range values are available for 8-isoprosante in exhaled breath condensate (EBC) of healthy adults, enabling its meaningful interpretation as a biomarker. We conducted this systematic review and meta-analysis according to the protocol following PROSPERO (CRD42020146623). After searching and analyzing the literature, we included 86 studies. After their qualitative synthesis and risk of bias assessment, 52 studies were included in meta-analysis. The latter focused on studies using immunological analytical methods and investigated how the concentrations of 8-isoprostane differ based on gender. We found that gender had no significant effect in 8-isoprostane concentration. Among other studied factors, such as individual characteristics and factors related to EBC collection, only the device used for EBC collection significantly affected measured 8-isoprostane concentrations. However, adjustment for the factors related to EBC collection, yielded uncertainty whether this effect is due to the device itself or to the other factors. Given this uncertainty, we estimated the reference range values of 8-isoprostane stratified by gender and EBC collection device. A better standardization of EBC collection seems necessary; as well more studies using chemical analytical methods to extend this investigation.

An approach to the integration of beach litter data from official monitoring programmes and citizen science.

Marine litter on Spanish beaches is assessed through two monitoring programmes: the Official Monitoring Programme of Marine Litter on Beaches (BM-1) developed by the Spanish Ministry for the Ecological Transition and the Demographic Challenge and the Citizen Science Monitoring Programme (BM-7) that provides beach litter data from voluntary clean-up initiatives. So far, the data provided by both programmes have been analysed separately although their integration could improve the assessment of the situation of Spanish beaches regarding marine litter. To this end, this paper studies the possible integration of both datasets through the calculation of a baseline value for marine litter on Spanish beaches. Statistical analysis of data shows that both datasets produce similar values and also integrate in a consistent way to achieve a value of 128 items/100 m as a baseline value for beach litter in Spain.

Baseline and power analyses for the assessment of beach litter reductions in the European OSPAR region.

Marine litter pollution is a global environmental problem. Beach litter is a part of this problem, and is widely monitored in Europe. The European Marine Strategy Framework Directive (MSFD) requires a reduction of beach litter. A reduction of 30% has been proposed in the European Plastics Strategy. The aims of this study are to develop (a) a method to calculate sufficiently stable and precise baseline values for beach litter, and (b) to derive a method of power analysis to estimate the number of beach litter surveys, necessary to detect a given reduction, using these baseline values. Beach litter data from the OSPAR (Oslo Paris Convention) region were used, and tailor-made statistical methods were implemented in open source software, litteR. Descriptive statistics and Theil-Sen and Mann-Kendall trend analyses were calculated for the most abundant beach litter types, for 14 survey sites. The length of a baseline period necessary to obtain a specified precision of the mean baseline value, expressed as Coefficient of Variation (CV), was calculated. Power analyses were performed using Monte Carlo simulations combined with Wilcoxon tests to determine significant deviations of the simulated datasets from the baseline mean values. For most survey sites, the mean length of monitoring periods necessary to achieve a CV < 10% amounts to four to five years with four surveys a year. The mean number of surveys necessary to detect a statistically significant reduction of 30% with 80% power ranges from 14 to 20. Power analyses show that a reduction of 10% is difficult to detect, because more than 24 surveys are needed. In contrary, a reduction of 40-50% can be detected easily with a small (<12) number of surveys. The new methods could also be applied to other areas where similar beach litter surveys are performed.

Assessment of organic and metallic contamination in the surface sediment of Monastir Bay (Eastern Tunisia): Spatial distribution, potential sources, and ecological risk assessment.

To investigate the current environment status in Monastir Bay (Tunisia), surface sediments from 32 stations were assessed for heavy metal and organic matter concentrations, and the results were compared with values of natural metal content, marine sediment quality standards, and other results concerning sediments from other Mediterranean coasts. The study of their spatial distributions refined by complementary approaches, including potential ecological risks determined through the enrichment factor, geo-accumulation index, contamination factor, potential ecological risk index, pollution load index, and principal component analysis, showed a significant impact of multiple anthropogenic sources. Moderate pollution of sediments, particularly by Ni and Cu, was also observed. Moreover, TOC values showed that the northern part of Monastir Bay is characterized by high levels of sediment organic matter because of the presence of fish farm cage. This baseline study can be used to establish background values for future sediment surveys.

[Determination of Heavy Metal Baseline Values and Analysis of Its Accumulation Characteristics in Agricultural Land in Chongqing].

In order to understand the accumulation of heavy metals of agricultural land in Chongqing and make clear priority control elements, the soil heavy metal baseline values need to be determined. Based on geochemical baselines, a total of 214 surface soil samples of six soil types were collected according to stratified sampling. Under strict quality control, the As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn content in each sample was measured. The baseline values of eight heavy metals were determined using mathematical statistics, iterative culling, and cumulative frequency curve methods. The accumulation of heavy metals in agricultural soils in Chongqing was evaluated using the geochemical baseline pollution and geological accumulation index methods. The mean baseline values of As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn in agricultural land in Chongqing were 5.83, 0.25, 66.78, 25.45, 0.069, 29.90, 26.18, and 78.44 mg·kg-1, respectively, which agreed with the historical findings. Evaluation of the geochemical baseline pollution index method showed that the accumulation of As, Hg, and Zn in soil was the most prominent, with 14.65%, 11.82%, and 3.88% of the samples reaching severe accumulation, respectively. The proportions of moderate accumulation of As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn were 12.12%, 6.50%, 3.79%, 6.50%, 15.27%, 5.29%, 5.45%, and 17.96%, respectively, of which As, Hg, and Zn were relatively large. The geological accumulation index indicated that more than 93% of the samples of Cd, Cr, Cu, Ni, and Pb were in a state of no accumulation. The proportions of mild accumulation of Hg, Zn, and As were 26.60%, 21.84%, and 21.21%, respectively. Only 5.56% and 0.49% of the samples had moderate accumulation of As and Zn. Different soil types have different properties. All soil types in the sample had different degrees of accumulation of the eight kinds of heavy metals. The accumulation of heavy metals in paddy and purple soils was lower than that in other soil types. For the soils of different geological and geomorphic types, the Ki values of As in the limestone middle and low mountain area of Daba Mountain in Northeast Chongqing and the low mountain area of the limestone of Wuling Mountain in Southeast Chongqing were relatively large; the rest were not significantly different, and all belonged to the non-accumulation and mild accumulation ranges. Both evaluation methods showed that the main accumulated heavy metals in agricultural land soil in Chongqing was As, followed by Hg and Zn, and management and prevention of the accumulation of these elements should be strengthened.

Assessing the Relationship between the Baseline Value of a Continuous Variable and Subsequent Change Over Time.

Analyzing the relationship between the baseline value and subsequent change of a continuous variable is a frequent matter of inquiry in cohort studies. These analyses are surprisingly complex, particularly if only two waves of data are available. It is unclear for non-biostatisticians where the complexity of this analysis lies and which statistical method is adequate. With the help of simulated longitudinal data of body mass index in children, we review statistical methods for the analysis of the association between the baseline value and subsequent change, assuming linear growth with time. Key issues in such analyses are mathematical coupling, measurement error, variability of change between individuals, and regression to the mean. Ideally, it is better to rely on multiple repeated measurements at different times and a linear random effects model is a standard approach if more than two waves of data are available. If only two waves of data are available, our simulations show that Blomqvist's method - which consists in adjusting for measurement error variance the estimated regression coefficient of observed change on baseline value - provides accurate estimates. The adequacy of the methods to assess the relationship between the baseline value and subsequent change depends on the number of data waves, the availability of information on measurement error, and the variability of change between individuals.

Dietary essential amino acids are highly anabolic in pediatric patients with cystic fibrosis.

BACKGROUND: Current nutritional approaches have been partially successful in Cystic Fibrosis (CF). Essential amino acids mixtures with high Leucine levels (EAA) have anabolic properties in catabolic conditions, however data in CF are lacking. METHODS: On two days according a randomized crossover design, 15 pediatric CF patients ingested 6.7 g EAA versus mixture of total amino acids as present in whey. Whole body protein and Arginine metabolism (as EAA lack Arginine) were assessed by stable isotope methodology. RESULTS: Protein synthesis (P<0.05) but not protein breakdown was higher after EAA and 70% higher values for net anabolism (P<0.001)were found both in patients with and without nutritional failure. Arginine turnover was lower (P<0.001) and de novo Arginine synthesis tended lower (P=0.09) after EAA. Nitric oxide synthesis was not different. CONCLUSIONS: CF patients are highly responsive to EAA intake independent of their nutritional status. Addition of Arginine to the EAA mixture may be warranted in CF.