616 research outputs found
Effects of Autism Spectrum Disorder Insurance Mandates on the Treated Prevalence of Autism Spectrum Disorder
Key Findings: State mandates requiring commercial health plans to cover services for children with autism spectrum disorder increased the number of children diagnosed with the disorder. However, diagnosis rates remain much lower than community estimates, suggesting that many commercially insured children with ASD remain undiagnosed or are insured through public plans
RNAi in Budding Yeast
RNA interference (RNAi), a gene-silencing pathway triggered by double-stranded RNA, is conserved in diverse eukaryotic species but has been lost in the model budding yeast Saccharomyces cerevisiae. Here, we show that RNAi is present in other budding yeast species, including Saccharomyces castellii and Candida albicans. These species use noncanonical Dicer proteins to generate small interfering RNAs, which mostly correspond to transposable elements and Y′ subtelomeric repeats. In S. castellii, RNAi mutants are viable but have excess Y′ messenger RNA levels. In S. cerevisiae, introducing Dicer and Argonaute of S. castellii restores RNAi, and the reconstituted pathway silences endogenous retrotransposons. These results identify a previously unknown class of Dicer proteins, bring the tool of RNAi to the study of budding yeasts, and bring the tools of budding yeast to the study of RNAi
Numbers and narratives: How qualitative methods can strengthen the science of paediatric antimicrobial stewardship
Antimicrobial and diagnostic stewardship initiatives have become increasingly important in paediatric settings. The value of qualitative approaches to conduct stewardship work in paediatric patients is being increasingly recognized. This article seeks to provide an introduction to basic elements of qualitative study designs and provide an overview of how these methods have successfully been applied to both antimicrobial and diagnostic stewardship work in paediatric patients. A multidisciplinary team of experts in paediatric infectious diseases, paediatric critical care and qualitative methods has written a perspective piece introducing readers to qualitative stewardship work in children, intended as an overview to highlight the importance of such methods and as a starting point for further work. We describe key differences between qualitative and quantitative methods, and the potential benefits of qualitative approaches. We present examples of qualitative research in five discrete topic areas of high relevance for paediatric stewardship work: provider attitudes; provider prescribing behaviours; stewardship in low-resource settings; parents\u27 perspectives on stewardship; and stewardship work focusing on select high-risk patients. Finally, we explore the opportunities for multidisciplinary academic collaboration, incorporation of innovative scientific disciplines and young investigator growth through the use of qualitative research in paediatric stewardship. Qualitative approaches can bring rich insights and critically needed new information to antimicrobial and diagnostic stewardship efforts in children. Such methods are an important tool in the armamentarium against worsening antimicrobial resistance, and a major opportunity for investigators interested in moving the needle forward for stewardship in paediatric patients
Design and Characterisation of a Randomized Food Intervention That Mimics Exposure to a Typical UK Diet to Provide Urine Samples for Identification and Validation of Metabolite Biomarkers of Food Intake
Poor dietary choices are major risk factors for obesity and non-communicable diseases, which places an increasing burden on healthcare systems worldwide. To monitor the effectiveness of healthy eating guidelines and strategies, there is a need for objective measures of dietary intake in community settings. Metabolites derived from specific foods present in urine samples can provide objective biomarkers of food intake (BFIs). Whilst the majority of biomarker discovery/validation studies have investigated potential biomarkers for single foods only, this study considered the whole diet by using menus that delivered a wide range of foods in meals that emulated conventional UK eating patterns. Fifty-one healthy participants (range 19–77 years; 57% female) followed a uniquely designed, randomized controlled dietary intervention, and provided spot urine samples suitable for discovery of BFIs within a real-world context. Free-living participants prepared and consumed all foods and drinks in their own homes and were asked to follow the protocols for meal consumption and home urine sample collection. This study also assessed the robustness, and impact on data quality, of a minimally invasive urine collection protocol. Overall the study design was well-accepted by participants and concluded successfully without any drop outs. Compliance for urine collection, adherence to menu plans, and observance of recommended meal timings, was shown to be very high. Metabolome analysis using mass spectrometry coupled with data mining demonstrated that the study protocol was well-suited for BFI discovery and validation. Novel, putative biomarkers for an extended range of foods were identified including legumes, curry, strongly-heated products, and artificially sweetened, low calorie beverages. In conclusion, aspects of this study design would help to overcome several current challenges in the development of BFI technology. One specific attribute was the examination of BFI generalizability across related food groups and across different preparations and cooking methods of foods. Furthermore, the collection of urine samples at multiple time points helped to determine which spot sample was optimal for identification and validation of BFIs in free-living individuals. A further valuable design feature centered on the comprehensiveness of the menu design which allowed the testing of biomarker specificity within a biobank of urine samples
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Research-based versus clinical serum creatinine measurements and the association of acute kidney injury with subsequent kidney function: findings from the Chronic Renal Insufficiency Cohort study.
Background:Observational studies relying on clinically obtained data have shown that acute kidney injury (AKI) is linked to accelerated chronic kidney disease (CKD) progression. However, prior reports lacked uniform collection of important confounders such as proteinuria and pre-AKI kidney function trajectory, and may be susceptible to ascertainment bias, as patients may be more likely to undergo kidney function testing after AKI. Methods:We studied 444 adults with CKD who participated in the prospective Chronic Renal Insufficiency Cohort (CRIC) Study and were concurrent members of a large integrated healthcare delivery system. We estimated glomerular filtration rate (eGFR) trajectories using serum creatinine measurements from (i) the CRIC research protocol (yearly) and (ii) routine clinical care. We used linear mixed effects models to evaluate the associations of AKI with acute absolute change in eGFR and post-AKI eGFR slope, and explored whether these varied by source of creatinine results. Models were adjusted for demographic characteristics, diabetes status and albuminuria. Results:During median follow-up of 8.5 years, mean rate of eGFR loss was -0.31 mL/min/1.73 m2/year overall, and 73 individuals experienced AKI (55% Stage 1). A significant interaction existed between AKI and source of serum creatinine for acute absolute change in eGFR level after discharge; in contrast, AKI was independently associated with a faster rate of eGFR decline (mean additional loss of -0.67 mL/min/1.73 m2/year), which was not impacted by source of serum creatinine. Conclusions:AKI is independently associated with subsequent steeper eGFR decline regardless of the serum creatinine source used, but the strength of association is smaller than observed in prior studies after taking into account key confounders such as pre-AKI eGFR slope and albuminuria
Developing a food exposure and urine sampling strategy for dietary exposure biomarker validation in free-living individuals
SCOPE: Dietary choices modulate the risk of chronic diseases and improving diet is a central component of public health strategies. Food-derived metabolites present in urine could provide objective biomarkers of dietary exposure. To assist biomarker validation we aimed to develop a food intervention strategy mimicking a typical annual diet over a short period of time and assessed urine sampling protocols potentially suitable for future deployment of biomarker technology in free-living populations. METHODS AND RESULTS: Six different menu plans representing comprehensively a typical UK annual diet that were split into two dietary experimental periods. Free-living adult participants (n = 15 and n = 36, respectively) were provided with all their food, as a series of menu plans, over a period of 3 consecutive days. Multiple spot urine samples were collected and stored at home. CONCLUSION: We established a successful food exposure strategy following a conventional UK eating pattern, which was suitable for biomarker validation in free-living individuals. The urine sampling procedure was acceptable for volunteers and delivered samples suitable for biomarker quantification. Our study design provides scope for validation of existing biomarker candidates and potentially for discovery of new biomarker-leads and should help inform the future deployment of biomarker technology for habitual dietary exposure measurement
Developing community-based urine sampling methods to deploy biomarker technology for the assessment of dietary exposure
Objective:
Obtaining objective, dietary exposure information from individuals is challenging because of the complexity of food consumption patterns and the limitations of self-reporting tools (e.g., FFQ and diet diaries). This hinders research efforts to associate intakes of specific foods or eating patterns with population health outcomes.
Design:
Dietary exposure can be assessed by the measurement of food-derived chemicals in urine samples. We aimed to develop methodologies for urine collection that minimised impact on the day-to-day activities of participants but also yielded samples that were data-rich in terms of targeted biomarker measurements.
Setting:
Urine collection methodologies were developed within home settings.
Participants:
Different cohorts of free-living volunteers.
Results:
Home collection of urine samples using vacuum transfer technology was deemed highly acceptable by volunteers. Statistical analysis of both metabolome and selected dietary exposure biomarkers in spot urine collected and stored using this method showed that they were compositionally similar to urine collected using a standard method with immediate sample freezing. Even without chemical preservatives, samples can be stored under different temperature regimes without any significant impact on the overall urine composition or concentration of forty-six exemplar dietary exposure biomarkers. Importantly, the samples could be posted directly to analytical facilities, without the need for refrigerated transport and involvement of clinical professionals.
Conclusions:
This urine sampling methodology appears to be suitable for routine use and may provide a scalable, cost-effective means to collect urine samples and to assess diet in epidemiological studies
DNA fragility in the parallel evolution of pelvic reduction in stickleback fish
Evolution generates a remarkable breadth of living forms, but many traits evolve repeatedly, by mechanisms that are still poorly understood. A classic example of repeated evolution is the loss of pelvic hindfins in stickleback fish (Gasterosteus aculeatus). Repeated pelvic loss maps to recurrent deletions of a pelvic enhancer of the Pitx1 gene. Here, we identify molecular features contributing to these recurrent deletions. Pitx1 enhancer sequences form alternative DNA structures in vitro and increase double-strand breaks and deletions in vivo. Enhancer mutability depends on DNA replication direction and is caused by TG-dinucleotide repeats. Modeling shows that elevated mutation rates can influence evolution under demographic conditions relevant for sticklebacks and humans. DNA fragility may thus help explain why the same loci are often used repeatedly during parallel adaptive evolution
Daily MODIS 500 m Reflectance Anisotropy Direct Broadcast (DB) Products for Monitoring Vegetation Phenology Dynamics
Land surface vegetation phenology is an efficient bio-indicator for monitoring ecosystem variation in response to changes in climatic factors. The primary objective of the current article is to examine the utility of the daily MODIS 500 m reflectance anisotropy direct broadcast (DB) product for monitoring the evolution of vegetation phenological trends over selected crop, orchard, and forest regions. Although numerous model-fitted satellite data have been widely used to assess the spatio-temporal distribution of land surface phenological patterns to understand phenological process and phenomena, current efforts to investigate the details of phenological trends, especially for natural phenological variations that occur on short time scales, are less well served by remote sensing challenges and lack of anisotropy correction in satellite data sources. The daily MODIS 500 m reflectance anisotropy product is employed to retrieve daily vegetation indices (VI) of a 1 year period for an almond orchard in California and for a winter wheat field in northeast China, as well as a 2 year period for a deciduous forest region in New Hampshire, USA. Compared with the ground records from these regions, the VI trajectories derived from the cloud-free and atmospherically corrected MODIS Nadir BRDF (bidirectional reflectance distribution function) adjusted reflectance (NBAR) capture not only the detailed footprint and principal attributes of the phenological events (such as flowering and blooming) but also the substantial inter-annual variability. This study demonstrates the utility of the daily 500 m MODIS reflectance anisotropy DB product to provide daily VI for monitoring and detecting changes of the natural vegetation phenology as exemplified by study regions comprising winter wheat, almond trees, and deciduous forest
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