Respiratory pathogen colonisation of dental plaque, the lower airways and endotracheal tube biofilms during mechanical ventilation

Purpose In mechanically ventilated patients, the endotracheal tube is an essential interface between the patient and ventilator, but inadvertently, it also facilitates the development of ventilator-associated pneumonia (VAP) by subverting pulmonary host defenses. A number of investigations suggest that bacteria colonizing the oral cavity may be important in the etiology of VAP. The present study evaluated microbial changes that occurred in dental plaque and lower airways of 107 critically ill mechanically ventilated patients. Materials and Methods Dental plaque and lower airways fluid was collected during the course of mechanical ventilation, with additional samples of dental plaque obtained during the entirety of patients' hospital stay. Results A “microbial shift” occurred in dental plaque, with colonization by potential VAP pathogens, namely, Staphylococcus aureus and Pseudomonas aeruginosa in 35 patients. Post-extubation analyses revealed that 70% and 55% of patients whose dental plaque included S aureus and P aeruginosa, respectively, reverted back to having a predominantly normal oral microbiota. Respiratory pathogens were also isolated from the lower airways and within the endotracheal tube biofilms. Conclusions To the best of our knowledge, this is the largest study to date exploring oral microbial changes during both mechanical ventilation and after recovery from critical illness. Based on these findings, it was apparent that during mechanical ventilation, dental plaque represents a source of potential VAP pathogens

Lyman Continuum Escape Fraction of Star-forming Dwarf Galaxies at z ~ 1

To date, no direct detection of Lyman continuum emission has been measured for intermediate-redshift (z ~ 1) star-forming galaxies. We combine Hubble Space Telescope grism spectroscopy with GALEX UV and ground-based optical imaging to extend the search for escaping Lyman continuum to a large (~600) sample of z ~ 1 low-mass log(M)≃ 9.3 M_☉), moderately star-forming (ψ ≾ 10M_☉ yr^(−1)) galaxies selected initially on Hα emission. The characteristic escape fraction of LyC from star-forming galaxies (SFGs) that populate this parameter space remains weakly constrained by previous surveys, but these faint (sub-Lsstarf) SFGs are assumed to play a significant role in the reionization of neutral hydrogen in the intergalactic medium (IGM) at high redshift z > 6. We do not make an unambiguous detection of escaping LyC radiation from this z ~ 1 sample, individual non-detections to constrain the absolute Lyman continuum escape fraction, f_(esc) 200Å), which are thought to be close analogs of high redshift sources of reionization. For reference, we also present an emissivity-weighted escape fraction that is useful for measuring the general contribution SFGs to the ionizing UV background. In the discussion, we consider the implications of these intermediate redshift constraints for the reionization of hydrogen in the IGM at high (z > 6) redshift. If we assume our z ~ 1 SFGs, for which we measure this emissivity-weighted f_(esc), are analogs to the high redshift sources of reionization, we find it is difficult to reconcile reionization by faint (M}_(UV) ≾-13) SFGs with a low escape fraction (f_(esc) < 3%), with constraints from independent high redshift observations. If f_(esc) evolves with redshift, reionization by SFGs may be consistent with observations from Planck

Carbon isotope alteration during the thermal maturation of non-flowering plant species representative of those found within the geological record

Rationale The carbon isotope (δ13C value) composition of fossil plant material is routinely used as a proxy of past climate and environment change. However, palaeoclimate interpretation requires assumptions about the stability of δ13C values in plant material during its decomposition and incorporation into sediments. Previous work on modern angiosperm species shows δ13C changes of several per mille during simulated decomposition experiments. However, no such tests have been undertaken on non-flowering plants, which are found extensively within the geological record. These plants have distinctly different cellulose-to-lignin ratios from those of their angiosperm counterparts, potentially creating hitherto unknown variations in the original to fossil δ13C signatures. Methods To test the extent of δ13C change during decomposition we have subjected a number of plants, representing more basal, non-flowering plant lineages (cycads, ferns, horsetails and dawn redwood), to artificial decay using a hydrothermal maturation technique at two temperatures over periods of up to 273 hours. Subsamples were extracted every 12–16 hours and analysed for their δ13C and %C values using a Carlo Erba 1500 elemental analyser, and VG TripleTrap and Optima mass spectrometers. Results The %C values increased for all samples through the maturation process at both temperatures with the largest increases observed within the first 24 hours. Decreases in δ13C values were observed for all plants at 300°C and for two of the species at the lower temperature (200°C). The maximum shift in the δ13C value related to experimental decomposition was −0.90‰ (horsetail), indicating a preferential loss of 13C during thermal maturation. Conclusions The reduction in the δ13C value potentially suggests a preferential loss of isotopically heavier cellulose in relation to the isotopically lighter lignin component during maturation. The isotopic offset observed here (<0.9‰) means that palaeoclimatic interpretation of δ13C values from non-flowering plant material within the geological record remains robust, but only where interpretations are based on variations in δ13C values greater than 1

Spectrum of mitochondrial genomic variation and associated clinical presentation of prostate cancer in South African men

BACKGROUND : Prostate cancer incidence and mortality rates are significantly increased in African–American men, but limited studies have been performed within Sub–Saharan African populations. As mitochondria control energy metabolism and apoptosis we speculate that somatic mutations within mitochondrial genomes are candidate drivers of aggressive prostate carcinogenesis. METHODS : We used matched blood and prostate tissue samples from 87 South African men (77 with African ancestry) to perform deep sequencing of complete mitochondrial genomes. Clinical presentation was biased toward aggressive disease (Gleason score >7, 64%), and compared with men without prostate cancer either with or without benign prostatic hyperplasia. RESULTS : We identified 144 somatic mtDNA single nucleotide variants (SNVs), of which 80 were observed in 39 men presenting with aggressive disease. Both the number and frequency of somatic mtDNA SNVs were associated with higher pathological stage. CONCLUSIONS : Besides doubling the total number of somatic PCa-associated mitochondrial genome mutations identified to date, we associate mutational load with aggressive prostate cancer status in men of African ancestry.NIH R21- CA170081, Australian Prostate Cancer Research Centre NSW, the J. Craig Venter Institute, the Garvan Institute, the Petre Foundation, Australia, the Cancer Association of South Africa (CANSA).http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1097-0045hb201

The Optimal Study: Describing the Key Components of Optimal Health Care Delivery to UK Care Home Residents: A Research Protocol

Long-term institutional care in the United Kingdom is provided by care homes. Residents have prevalent cognitive impairment and disability, have multiple diagnoses, and are subject to polypharmacy. Prevailing models of health care provision (ad hoc, reactive, and coordinated by general practitioners) result in unacceptable variability of care. A number of innovative responses to improve health care for care homes have been commissioned. The organization of health and social care in the United Kingdom is such that it is unlikely that a single solution to the problem of providing quality health care for care homes will be identified that can be used nationwide. Realist evaluation is a methodology that uses both qualitative and quantitative data to establish an in-depth understanding of what works, for whom, and in what settings. In this article we describe a protocol for using realist evaluation to understand the context, mechanisms, and outcomes that shape effective health care delivery to care home residents in the United Kingdom. By describing this novel approach, we hope to inform international discourse about research methodologies in long-term care settings internationally

Mental Contrasting With Implementation Intentions Reduces Drinking When Drinking Is Hazardous: An Online Self-Regulation Intervention

Introduction. Drinking alcohol has detrimental health consequences, and effective interventions to reduce hazardous drinking are needed. The self-regulation intervention of Mental Contrasting with Implementation Intentions (MCII) promotes behavior change across a variety of health behaviors. In this study, we tested if online delivery of MCII reduced hazardous drinking in people who were worried about their drinking. Method. Participants (N = 200, female = 107) were recruited online. They were randomized to learn MCII or solve simple math problems (control). Results. Immediately after the intervention, participants in the MCII condition (vs. control) reported an increased commitment to reduce drinking. After 1 month, they reported having taken action measured by the Readiness to Change drinking scale. When drinking was hazardous (Alcohol Use Disorders Identification Test ≥ 8, n = 85), participants in the MCII condition indicated a decreased number of drinking days, exp(β) = 0.47, CI (confidence interval) [−1.322, −.207], p = .02, and drinks per week, exp(β) = 0.57, CI [0.94, 5.514], p = .007, compared with the control condition. Discussion. These findings demonstrate that a brief, self-guided online intervention (Mdn = 28 minutes) can reduce drinking in people who worry about their drinking. Our findings show a higher impact in people at risk for hazardous drinking. Conclusion. MCII is scalable as an online intervention. Future studies should test the cost-effectiveness of the intervention in real-world settings

Heterogeneous contributions of change in population distribution of body mass index to change in obesity and underweight

From 1985 to 2016, the prevalence of underweight decreased, and that of obesity and severe obesity increased, in most regions, with significant variation in the magnitude of these changes across regions. We investigated how much change in mean body mass index (BMI) explains changes in the prevalence of underweight, obesity, and severe obesity in different regions using data from 2896 population-based studies with 187 million participants. Changes in the prevalence of underweight and total obesity, and to a lesser extent severe obesity, are largely driven by shifts in the distribution of BMI, with smaller contributions from changes in the shape of the distribution. In East and Southeast Asia and sub-Saharan Africa, the underweight tail of the BMI distribution was left behind as the distribution shifted. There is a need for policies that address all forms of malnutrition by making healthy foods accessible and affordable, while restricting unhealthy foods through fiscal and regulatory restrictions

Worldwide trends in body-mass index, underweight, overweight, and obesity from 1975 to 2016: a pooled analysis of 2416 population-based measurement studies in 128·9 million children, adolescents, and adults

Background Underweight, overweight, and obesity in childhood and adolescence are associated with adverse health consequences throughout the life-course. Our aim was to estimate worldwide trends in mean body-mass index (BMI) and a comprehensive set of BMI categories that cover underweight to obesity in children and adolescents, and to compare trends with those of adults. Methods We pooled 2416 population-based studies with measurements of height and weight on 128·9 million participants aged 5 years and older, including 31·5 million aged 5–19 years. We used a Bayesian hierarchical model to estimate trends from 1975 to 2016 in 200 countries for mean BMI and for prevalence of BMI in the following categories for children and adolescents aged 5–19 years: more than 2 SD below the median of the WHO growth reference for children and adolescents (referred to as moderate and severe underweight hereafter), 2 SD to more than 1 SD below the median (mild underweight), 1 SD below the median to 1 SD above the median (healthy weight), more than 1 SD to 2 SD above the median (overweight but not obese), and more than 2 SD above the median (obesity). Findings Regional change in age-standardised mean BMI in girls from 1975 to 2016 ranged from virtually no change (−0·01 kg/m2 per decade; 95% credible interval −0·42 to 0·39, posterior probability [PP] of the observed decrease being a true decrease=0·5098) in eastern Europe to an increase of 1·00 kg/m2 per decade (0·69–1·35, PP\u3e0·9999) in central Latin America and an increase of 0·95 kg/m2 per decade (0·64–1·25, PP\u3e0·9999) in Polynesia and Micronesia. The range for boys was from a non-significant increase of 0·09 kg/m2 per decade (−0·33 to 0·49, PP=0·6926) in eastern Europe to an increase of 0·77 kg/m2 per decade (0·50–1·06, PP\u3e0·9999) in Polynesia and Micronesia. Trends in mean BMI have recently flattened in northwestern Europe and the high-income English-speaking and Asia-Pacific regions for both sexes, southwestern Europe for boys, and central and Andean Latin America for girls. By contrast, the rise in BMI has accelerated in east and south Asia for both sexes, and southeast Asia for boys. Global age-standardised prevalence of obesity increased from 0·7% (0·4–1·2) in 1975 to 5·6% (4·8–6·5) in 2016 in girls, and from 0·9% (0·5–1·3) in 1975 to 7·8% (6·7–9·1) in 2016 in boys; the prevalence of moderate and severe underweight decreased from 9·2% (6·0–12·9) in 1975 to 8·4% (6·8–10·1) in 2016 in girls and from 14·8% (10·4–19·5) in 1975 to 12·4% (10·3–14·5) in 2016 in boys. Prevalence of moderate and severe underweight was highest in India, at 22·7% (16·7–29·6) among girls and 30·7% (23·5–38·0) among boys. Prevalence of obesity was more than 30% in girls in Nauru, the Cook Islands, and Palau; and boys in the Cook Islands, Nauru, Palau, Niue, and American Samoa in 2016. Prevalence of obesity was about 20% or more in several countries in Polynesia and Micronesia, the Middle East and north Africa, the Caribbean, and the USA. In 2016, 75 (44–117) million girls and 117 (70–178) million boys worldwide were moderately or severely underweight. In the same year, 50 (24–89) million girls and 74 (39–125) million boys worldwide were obese. Interpretation The rising trends in children\u27s and adolescents\u27 BMI have plateaued in many high-income countries, albeit at high levels, but have accelerated in parts of Asia, with trends no longer correlated with those of adults. Funding Wellcome Trust, AstraZeneca Young Health Programme

Stream and slope weathering effects on organic-rich mudstone geochemistry and implications for hydrocarbon source rock assessment: a Bowland Shale case study

This study contributes to the exploration and quantification of the weathering of organic-rich mudstones under temperate climatic conditions. Bowland Shales, exposed by a stream and slope, were sampled in order to develop a model for the effects of weathering on the mudstone geochemistry, including major and trace element geochemistry, Rock-Eval pyrolysis and δ13Corg. Four weathering grades (I – IV) are defined using a visual classification scheme; visually fresh and unaltered (I), chemically altered (II, III) and ‘paper shale’ that typifies weathered mudstone on slopes (IV). Bedload abrasion in the stream exposes of visually fresh and geochemically unaltered mudstone. Natural fractures are conduits for oxidising meteoric waters that promote leaching at the millimetre scale and/or precipitation of iron oxide coatings along fracture surfaces. On the slope, bedding-parallel fractures formed (and may continue to form) in response to chemical and/or physical weathering processes. These fractures develop along planes of weakness, typically along laminae comprising detrital grains, and exhibit millimetre- and centimetre-scale leached layers and iron oxide coatings. Fracture surfaces are progressively exposed to physical weathering processes towards the outcrop surface, and results in disintegration of the altered material along fracture surfaces. Grade IV, ‘paper shale’ mudstone is chemically unaltered but represents a biased record driven by initial heterogeneity in the sedimentary fabric. Chemically weathered outcrop samples exhibit lower concentrations of both ‘free’ (S1) (up to 0.6 mgHC/g rock) and ‘bound’ (S2) (up to 3.2 mgHC/g rock) hydrocarbon, reduced total organic carbon content (up to 0.34 wt%), reduced hydrogen index (up to 58 mgHC/gTOC), increased oxygen index (up to 19 mgCO + CO2/gTOC) and increased Tmax (up to 11 °C) compared with unaltered samples. If analysis of chemically weathered samples is unavoidable, back-extrapolation of Rock-Eval parameters can assist in the estimation of pre-weathering organic compositions. Combining Cs/Cu with oxygen index is a proxy for identifying the weathering progression from fresh material (I) to ‘paper shale’ (IV). This study demonstrates that outcrop samples in temperate climates can provide information for assessing hydrocarbon potential of organic-rich mudstones