Chronic kidney disease in children: the global perspective

In contrast to the increasing availability of information pertaining to the care of children with chronic kidney disease (CKD) from large-scale observational and interventional studies, epidemiological information on the incidence and prevalence of pediatric CKD is currently limited, imprecise, and flawed by methodological differences between the various data sources. There are distinct geographic differences in the reported causes of CKD in children, in part due to environmental, racial, genetic, and cultural (consanguinity) differences. However, a substantial percentage of children develop CKD early in life, with congenital renal disorders such as obstructive uropathy and aplasia/hypoplasia/dysplasia being responsible for almost one half of all cases. The most favored end-stage renal disease (ESRD) treatment modality in children is renal transplantation, but a lack of health care resources and high patient mortality in the developing world limits the global provision of renal replacement therapy (RRT) and influences patient prevalence. Additional efforts to define the epidemiology of pediatric CKD worldwide are necessary if a better understanding of the full extent of the problem, areas for study, and the potential impact of intervention is desired

Development of a heart failure filter for Medline: an objective approach using evidence-based clinical practice guidelines as an alternative to hand searching

<p>Abstract</p> <p>Background</p> <p>Heart failure is a highly debilitating syndrome with a poor prognosis primarily affecting the elderly. Clinicians wanting timely access to heart failure evidence to provide optimal patient care can face many challenges in locating this evidence.</p> <p>This study developed and validated a search filter of high clinical utility for the retrieval of heart failure articles in OvidSP Medline.</p> <p>Methods</p> <p>A Clinical Advisory Group was established to advise study investigators. The study set of 876 relevant articles from four heart failure clinical practice guidelines was divided into three datasets: a Term Identification Set, a Filter Development Set, and a Filter Validation Set. A further validation set (the Cochrane Validation Set) was formed using studies included in Cochrane heart failure systematic reviews. Candidate search terms were identified via word frequency analysis. The filter was developed by creating combinations of terms and recording their performance in retrieving items from the Filter Development Set. The filter's recall was then validated in both the Filter Validation Set and the Cochrane Validation Set. A precision estimate was obtained post-hoc by running the filter in Medline and screening the first 200 retrievals for relevance to heart failure.</p> <p>Results</p> <p>The four-term filter achieved a recall of 96.9% in the Filter Development Set; 98.2% in the Filter Validation Set; and 97.8% in the Cochrane Validation Set. Of the first 200 references retrieved by the filter when run in Medline, 150 were deemed relevant and 50 irrelevant. The post-hoc precision estimate was therefore 75%.</p> <p>Conclusions</p> <p>This study describes an objective method for developing a validated heart failure filter of high recall performance and then testing its precision post-hoc. Clinical practice guidelines were found to be a feasible alternative to hand searching in creating a gold standard for filter development. Guidelines may be especially appropriate given their clinical utility. A validated heart failure filter is now available to support health professionals seeking reliable and efficient access to the heart failure literature.</p

Concentrations and fluxes of water soluble inorganic aerosol components above tropical rainforest

The interaction between biosphere and atmosphere in the cycling of gas and aerosol species is of key importance in considering overall emission and deposition rates of nutrients and pollutants. Understanding of the biosphereatmosphere processes that govern these cycles is critical to modelling global concentrations of atmospheric aerosols and trace gases, which in turn is vital to developing predictions for future climate, air quality and trans‐boundary air pollution. However, to understand these processes, more measurements over a variety of different ecosystems are required, preferably measurements which are taken in real time, which are of high temporal resolution and record a variety of species simultaneously and at potentially low background concentrations. In particular, very little is known about the role of biosphere‐atmosphere exchange in the nutrient cycling in and above tropical rain forests. While aerosol concentrations can provide information on the regional transport of compounds, fluxes allow an insight into the chemical process in the forest. In this work, the concentrations and fluxes of water‐soluble aerosol species NH4 +, Cl‐, NO2 ‐, NO3 ‐ and SO4 2‐ in total suspended particulate (TSP) and their precursor gases NH3, HCl, HNO2, HNO3 and SO2 were measured using a Gradient of Aerosols and Gases Online Registrator (GRAEGOR) above a tropical rainforest site located at the Amazon Tall Tower Observatory (ATTO) in Amazonia, Brazil. Measurements were taken during the dry season from the 4 October to 10 November 2017. From the measured concentration‐gradients and ancillary meteorological measurements, fluxes for each species were derived using the hybrid Aerodynamic Gradient Method and the Modified Bowen Ratio Method. Deposition velocities for each species were calculated and compared to theoretical deposition velocities, and interpreted in relation to measurements of leaf wetness at the canopy level. The average concentrations for aerosol species at each of the measurement heights (42 m and 60 m) throughout the campaign were 0.26/0.26 μg m‐3 for NH4 +, 0.11/0.12 μg m‐3 for Cl‐, 0.39/0.48 μg m‐3 for NO3 ‐ and 0.48/0.49 μg m‐3 for SO4 2‐. The mean concentration values of measured precursor gases were 0.26/0.23 μg m‐3 for NH3, 0.10/0.11 μg m‐3 for HCl, 0.06/0.06 μg m‐3 for HNO2, 0.24/0.26 μg m‐3 for HNO3 and 0.20/0.23 μg m‐3 for SO2. The aerosol concentration values were mostly in agreement with previous measurements made at similar time of year, except for higher mass fraction contribution of chloride and nitrate in the current study. This could indicate regional or long‐distance transport of coarse chloride (sea salt) and coarse nitrate that previous measurements would not have detected due to their use of a smaller particle size cut‐off compared with the one in this study. Copyright © 2018 by the International Aerosol Conference (IAC)

Effect of age on proximal esophageal response to swallowing

CONTEXT: It has been demonstrated that the ageing process affects esophageal motility. OBJECTIVES: To evaluate the effect of the age on the proximal esophageal response to wet swallows. METHOD: We measured the proximal esophageal response to swallows of a 5 mL bolus of water in 69 healthy volunteers, 20 of them aged 18-30 years (group I), 27 aged 31-50 years (group II), and 22 aged 51-74 years (group III). We used the manometric method with continuous perfusion. The proximal esophageal contractions were recorded 5 cm from a pharyngeal recording site located 1 cm above the upper esophageal sphincter. The time between the onset of the pharyngeal and of the proximal esophageal recording (pharyngeal-esophageal time) and the amplitude, duration and area under the curve of the proximal esophageal contraction were measured. RESULTS: The pharyngeal-esophageal time was shorter in group I subjects than in group II and III subjects (P<0.05). The duration of proximal esophageal contractions was longer in group I than in groups II and III (P<0.001). There was no differences between groups in the amplitude or area under the curve of contractions. There were no differences between groups II and III for any of the measurements. CONCLUSION: We conclude that the age may affects the response of the proximal esophagus to wet swallows