Directed evolution of a far-red fluorescent rhodopsin

Microbial rhodopsins are a diverse group of photoactive transmembrane proteins found in all three domains of life. A member of this protein family, Archaerhodopsin-3 (Arch) of halobacterium Halorubrum sodomense, was recently shown to function as a fluorescent indicator of membrane potential when expressed in mammalian neurons. Arch fluorescence, however, is very dim and is not optimal for applications in live-cell imaging. We used directed evolution to identify mutations that dramatically improve the absolute brightness of Arch, as confirmed biochemically and with live-cell imaging (in Escherichia coli and human embryonic kidney 293 cells). In some fluorescent Arch variants, the pK_a of the protonated Schiff-base linkage to retinal is near neutral pH, a useful feature for voltage-sensing applications. These bright Arch variants enable labeling of biological membranes in the far-red/infrared and exhibit the furthest red-shifted fluorescence emission thus far reported for a fluorescent protein (maximal excitation/emission at ∼620 nm/730 nm)

Pre-arrest and intra-arrest prognostic factors associated with survival after in-hospital cardiac arrest : systematic review and meta-analysis

Abstract: Objective: To determine associations between important pre-arrest and intra-arrest prognostic factors and survival after in-hospital cardiac arrest. Design: Systematic review and meta-analysis. Data sources: Medline, PubMed, Embase, Scopus, Web of Science, and the Cochrane Database of Systematic Reviews from inception to 4 February 2019. Primary, unpublished data from the United Kingdom National Cardiac Arrest Audit database. Study selection criteria: English language studies that investigated pre-arrest and intra-arrest prognostic factors and survival after in-hospital cardiac arrest. Data extraction: PROGRESS (prognosis research strategy group) recommendations and the CHARMS (critical appraisal and data extraction for systematic reviews of prediction modelling studies) checklist were followed. Risk of bias was assessed by using the QUIPS tool (quality in prognosis studies). The primary analysis pooled associations only if they were adjusted for relevant confounders. The GRADE approach (grading of recommendations assessment, development, and evaluation) was used to rate certainty in the evidence. Results: The primary analysis included 23 cohort studies. Of the pre-arrest factors, male sex (odds ratio 0.84, 95% confidence interval 0.73 to 0.95, moderate certainty), age 60 or older (0.50, 0.40 to 0.62, low certainty), active malignancy (0.57, 0.45 to 0.71, high certainty), and history of chronic kidney disease (0.56, 0.40 to 0.78, high certainty) were associated with reduced odds of survival after in-hospital cardiac arrest. Of the intra-arrest factors, witnessed arrest (2.71, 2.17 to 3.38, high certainty), monitored arrest (2.23, 1.41 to 3.52, high certainty), arrest during daytime hours (1.41, 1.20 to 1.66, high certainty), and initial shockable rhythm (5.28, 3.78 to 7.39, high certainty) were associated with increased odds of survival. Intubation during arrest (0.54, 0.42 to 0.70, moderate certainty) and duration of resuscitation of at least 15 minutes (0.12, 0.07 to 0.19, high certainty) were associated with reduced odds of survival. Conclusion: Moderate to high certainty evidence was found for associations of pre-arrest and intra-arrest prognostic factors with survival after in-hospital cardiac arrest. Systematic review registration: PROSPERO CRD4201810479

Pre-arrest and intra-arrest prognostic factors associated with survival after in-hospital cardiac arrest : systematic review and meta-analysis

Abstract: Objective: To determine associations between important pre-arrest and intra-arrest prognostic factors and survival after in-hospital cardiac arrest. Design: Systematic review and meta-analysis. Data sources: Medline, PubMed, Embase, Scopus, Web of Science, and the Cochrane Database of Systematic Reviews from inception to 4 February 2019. Primary, unpublished data from the United Kingdom National Cardiac Arrest Audit database. Study selection criteria: English language studies that investigated pre-arrest and intra-arrest prognostic factors and survival after in-hospital cardiac arrest. Data extraction: PROGRESS (prognosis research strategy group) recommendations and the CHARMS (critical appraisal and data extraction for systematic reviews of prediction modelling studies) checklist were followed. Risk of bias was assessed by using the QUIPS tool (quality in prognosis studies). The primary analysis pooled associations only if they were adjusted for relevant confounders. The GRADE approach (grading of recommendations assessment, development, and evaluation) was used to rate certainty in the evidence. Results: The primary analysis included 23 cohort studies. Of the pre-arrest factors, male sex (odds ratio 0.84, 95% confidence interval 0.73 to 0.95, moderate certainty), age 60 or older (0.50, 0.40 to 0.62, low certainty), active malignancy (0.57, 0.45 to 0.71, high certainty), and history of chronic kidney disease (0.56, 0.40 to 0.78, high certainty) were associated with reduced odds of survival after in-hospital cardiac arrest. Of the intra-arrest factors, witnessed arrest (2.71, 2.17 to 3.38, high certainty), monitored arrest (2.23, 1.41 to 3.52, high certainty), arrest during daytime hours (1.41, 1.20 to 1.66, high certainty), and initial shockable rhythm (5.28, 3.78 to 7.39, high certainty) were associated with increased odds of survival. Intubation during arrest (0.54, 0.42 to 0.70, moderate certainty) and duration of resuscitation of at least 15 minutes (0.12, 0.07 to 0.19, high certainty) were associated with reduced odds of survival. Conclusion: Moderate to high certainty evidence was found for associations of pre-arrest and intra-arrest prognostic factors with survival after in-hospital cardiac arrest. Systematic review registration: PROSPERO CRD4201810479

Elevated Paracellular Glucose Flux across Cystic Fibrosis Airway Epithelial Monolayers Is an Important Factor for Pseudomonas aeruginosa Growth.

People with cystic fibrosis (CF) who develop related diabetes (CFRD) have accelerated pulmonary decline, increased infection with antibiotic-resistant Pseudomonas aeruginosa and increased pulmonary exacerbations. We have previously shown that glucose concentrations are elevated in airway surface liquid (ASL) of people with CF, particularly in those with CFRD. We therefore explored the hypotheses that glucose homeostasis is altered in CF airway epithelia and that elevation of glucose flux into ASL drives increased bacterial growth, with an effect over and above other cystic fibrosis transmembrane conductance regulator (CFTR)-related ASL abnormalities. The aim of this study was to compare the mechanisms governing airway glucose homeostasis in CF and non-CF primary human bronchial epithelial (HBE) monolayers, under normal conditions and in the presence of Ps. aeruginosa filtrate. HBE-bacterial co-cultures were performed in the presence of 5 mM or 15 mM basolateral glucose to investigate how changes in blood glucose, such as those seen in CFRD, affects luminal Ps. aeruginosa growth. Calu-3 cell monolayers were used to evaluate the potential importance of glucose on Ps. aeruginosa growth, in comparison to other hallmarks of the CF ASL, namely mucus hyperviscosity and impaired CFTR-dependent fluid secretions. We show that elevation of basolateral glucose promotes the apical growth of Ps. aeruginosa on CF airway epithelial monolayers more than non-CF monolayers. Ps. aeruginosa secretions elicited more glucose flux across CF airway epithelial monolayers compared to non-CF monolayers which we propose increases glucose availability in ASL for bacterial growth. In addition, elevating basolateral glucose increased Ps. aeruginosa growth over and above any CFTR-dependent effects and the presence or absence of mucus in Calu-3 airway epithelia-bacteria co-cultures. Together these studies highlight the importance of glucose as an additional factor in promoting Ps. aeruginosa growth and respiratory infection in CF disease

Understanding How Inequality in the Distribution of Income Affects Health

Research on the determinants of health has almost exclusively focused on the individual but it seems clear we cannot understand or improve patterns of population health without engaging structural determinants at the societal level. This article traces the development of research on income distribution and health to the most recent epidemiologic studies from the USA that show how income inequality is related to age-adjusted mortality within the 50 States. (r 520.62, p 5 0.0001) even after accounting for absolute levels of income. We discuss potential material, psychological, social and behavioral pathways through which income distribution might be linked to health status. Distributional aspects of the economy are important determinants of health and may well provide one of the most pertinent indicators of overall social well-being.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66686/2/10.1177_135910539700200303.pd

Accuracy of syndrome definitions based on diagnoses in physician claims

<p>Abstract</p> <p>Background</p> <p>Community clinics offer potential for timelier outbreak detection and monitoring than emergency departments. However, the accuracy of syndrome definitions used in surveillance has never been evaluated in community settings. This study's objective was to assess the accuracy of syndrome definitions based on diagnostic codes in physician claims for identifying 5 syndromes (fever, gastrointestinal, neurological, rash, and respiratory including influenza-like illness) in community clinics.</p> <p>Methods</p> <p>We selected a random sample of 3,600 community-based primary care physicians who practiced in the fee-for-service system in the province of Quebec, Canada in 2005-2007. We randomly selected 10 visits per physician from their claims, stratifying on syndrome type and presence, diagnosis, and month. Double-blinded chart reviews were conducted by telephone with consenting physicians to obtain information on patient diagnoses for each sampled visit. The sensitivity, specificity, and positive predictive value (PPV) of physician claims were estimated by comparison to chart review.</p> <p>Results</p> <p>1,098 (30.5%) physicians completed the chart review. A chart entry on the date of the corresponding claim was found for 10,529 (95.9%) visits. The sensitivity of syndrome definitions based on diagnostic codes in physician claims was low, ranging from 0.11 (fever) to 0.44 (respiratory), the specificity was high, and the PPV was moderate to high, ranging from 0.59 (fever) to 0.85 (respiratory). We found that rarely used diagnostic codes had a higher probability of being false-positives, and that more commonly used diagnostic codes had a higher PPV.</p> <p>Conclusions</p> <p>Future research should identify physician, patient, and encounter characteristics associated with the accuracy of diagnostic codes in physician claims. This would enable public health to improve syndromic surveillance, either by focusing on physician claims whose diagnostic code is more likely to be accurate, or by using all physician claims and weighing each according to the likelihood that its diagnostic code is accurate.</p

Assessment of health care needs and utilization in a mixed public-private system: the case of the Athens area

BACKGROUND: Given the public-private mix of the Greek health system, the purpose of this study was to assess whether variations in the utilisation of health services, both primary and inpatient care, were associated with underlying health care needs and/or various socio-economic factors. METHODS: Data was obtained from a representative sample (N = 1426) residing in the broader Athens area (response rate 70.6%). Perceived health-related quality of life (HRQOL), as measured by the physical and mental summary component scores of the SF-36 Health Survey, was used as a proxy of health care need. Health care utilization was measured by a) last-month visits to public sector physicians, b) last-month visits to private sector physicians, c) last-year visits to hospital emergency departments and d) last-year hospital admissions. Statistical analysis involved the implementation of logistic regression models. RESULTS: Health care need was the factor most strongly associated with all measures of health care utilization, except for visits to public physicians. Women, elderly, less wealthy and individuals of lower physical health status visited physicians contracted to their insurance fund (public sector). Women, well educated and those once again of lower physical health status were more likely to visit private providers. Visits to hospital emergency departments and hospital admissions were related to need and no socio-economic factor was related to the use of those types of care. CONCLUSION: This study has demonstrated a positive relationship between health care need and utilisation of health services within a mixed public-private health care system. Concurrently, interesting differences are evident in the utilization of various types of services. The results have potential implications in health policy-making and particularly in the proper allocation of scarce health resources

Stream denitrification across biomes and its response to anthropogenic nitrate loading

Author Posting. © The Author(s), 2008. This is the author's version of the work. It is posted here by permission of Nature Publishing Group for personal use, not for redistribution. The definitive version was published in Nature 452 (2008): 202-205, doi:10.1038/nature06686.Worldwide, anthropogenic addition of bioavailable nitrogen (N) to the biosphere is increasing and terrestrial ecosystems are becoming increasingly N saturated, causing more bioavailable N to enter groundwater and surface waters. Large-scale N budgets show that an average of about 20-25% of the N added to the biosphere is exported from rivers to the ocean or inland basins, indicating substantial sinks for N must exist in the landscape. Streams and rivers may be important sinks for bioavailable N owing to their hydrologic connections with terrestrial systems, high rates of biological activity, and streambed sediment environments that favor microbial denitrification. Here, using data from 15N tracer experiments replicated across 72 streams and 8 regions representing several biomes, we show that total biotic uptake and denitrification of nitrate increase with stream nitrate concentration, but that the efficiency of biotic uptake and denitrification declines as concentration increases, reducing the proportion of instream nitrate that is removed from transport. Total uptake of nitrate was related to ecosystem photosynthesis and denitrification was related to ecosystem respiration. Additionally, we use a stream network model to demonstrate that excess nitrate in streams elicits a disproportionate increase in the fraction of nitrate that is exported to receiving waters and reduces the relative role of small versus large streams as nitrate sinks.Funding for this research was provided by the National Science Foundation