In situ permafrost thaw due to climate change drives holistic microbial community shifts with implications for methane cycling

Thawing permafrost is a potentially significant source of radiative forcing feedback due to increased emissions of methane, a biogenic greenhouse gas (GHG). This study investigated changes in the microbial community along a permafrost thaw gradient at Stordalen Mire, Sweden using 16S rRNA gene amplicon and metagenomic methods. In situ measurements of geochemical parameters, including CH4 and C isotopes, enabled linkage of community dynamics to significant shifts in C balance. The thaw gradient ranged from intact at a palsa (low productivity and GHG emissions), through partially thawed in a bog (high productivity, low GHG emissions) to a completely thawed fen (high productivity and GHG emissions). Microbial assemblages in both the palsa and fen were highly diverse (in both richness and evenness), consistent with climax communities. The microbial community in the bog had distinctly lower diversity, characteristic of ecosystem disturbance. The palsa community was dominated by Acidobacteria and Proteobacteria, as is typical of a range of soils including permafrost. Methanogens dominated both the bog and fen and were most abundant within the zone of water table fluctuation. Inferring methanogens’ production pathway from phylogeny showed a shift from mostly hydrogenotrophic methanogens in the bog towards acetotrophic methanogens in the fen. This corroborated porewater and flux emitted CH4 and CO2 carbon isotopic 13C signatures of CH4 and CO2. The fen, where the highest CH4 flux was recorded, was significantly richer in methanogenic archaea. A novel archaea, Candidatus Methanoflorens stordalenmirensis, was present at up to 70% relative abundance in the bog, enabling recovery of a population genome. The genome (and associated metaproteome) of ’M. stordalenmirensis’ indicates that hydrogenotrophic methane production is its main energy conservation pathway. ’Methanoflorens’ may be an indicator species of permafrost thaw, it is globally ubiquitous, and appears a major contributor to global methane production. Our results revealed a distinct difference in the microbial community structure and membership at each site, which can be directly associated with increasing methane emission and thaw state

Utilisation of an operative difficulty grading scale for laparoscopic cholecystectomy

Background A reliable system for grading operative difficulty of laparoscopic cholecystectomy would standardise description of findings and reporting of outcomes. The aim of this study was to validate a difficulty grading system (Nassar scale), testing its applicability and consistency in two large prospective datasets. Methods Patient and disease-related variables and 30-day outcomes were identified in two prospective cholecystectomy databases: the multi-centre prospective cohort of 8820 patients from the recent CholeS Study and the single-surgeon series containing 4089 patients. Operative data and patient outcomes were correlated with Nassar operative difficultly scale, using Kendall’s tau for dichotomous variables, or Jonckheere–Terpstra tests for continuous variables. A ROC curve analysis was performed, to quantify the predictive accuracy of the scale for each outcome, with continuous outcomes dichotomised, prior to analysis. Results A higher operative difficulty grade was consistently associated with worse outcomes for the patients in both the reference and CholeS cohorts. The median length of stay increased from 0 to 4 days, and the 30-day complication rate from 7.6 to 24.4% as the difficulty grade increased from 1 to 4/5 (both p < 0.001). In the CholeS cohort, a higher difficulty grade was found to be most strongly associated with conversion to open and 30-day mortality (AUROC = 0.903, 0.822, respectively). On multivariable analysis, the Nassar operative difficultly scale was found to be a significant independent predictor of operative duration, conversion to open surgery, 30-day complications and 30-day reintervention (all p < 0.001). Conclusion We have shown that an operative difficulty scale can standardise the description of operative findings by multiple grades of surgeons to facilitate audit, training assessment and research. It provides a tool for reporting operative findings, disease severity and technical difficulty and can be utilised in future research to reliably compare outcomes according to case mix and intra-operative difficulty

Population‐based cohort study of outcomes following cholecystectomy for benign gallbladder diseases

Background The aim was to describe the management of benign gallbladder disease and identify characteristics associated with all‐cause 30‐day readmissions and complications in a prospective population‐based cohort. Methods Data were collected on consecutive patients undergoing cholecystectomy in acute UK and Irish hospitals between 1 March and 1 May 2014. Potential explanatory variables influencing all‐cause 30‐day readmissions and complications were analysed by means of multilevel, multivariable logistic regression modelling using a two‐level hierarchical structure with patients (level 1) nested within hospitals (level 2). Results Data were collected on 8909 patients undergoing cholecystectomy from 167 hospitals. Some 1451 cholecystectomies (16·3 per cent) were performed as an emergency, 4165 (46·8 per cent) as elective operations, and 3293 patients (37·0 per cent) had had at least one previous emergency admission, but had surgery on a delayed basis. The readmission and complication rates at 30 days were 7·1 per cent (633 of 8909) and 10·8 per cent (962 of 8909) respectively. Both readmissions and complications were independently associated with increasing ASA fitness grade, duration of surgery, and increasing numbers of emergency admissions with gallbladder disease before cholecystectomy. No identifiable hospital characteristics were linked to readmissions and complications. Conclusion Readmissions and complications following cholecystectomy are common and associated with patient and disease characteristics

The development and validation of a scoring tool to predict the operative duration of elective laparoscopic cholecystectomy

Background: The ability to accurately predict operative duration has the potential to optimise theatre efficiency and utilisation, thus reducing costs and increasing staff and patient satisfaction. With laparoscopic cholecystectomy being one of the most commonly performed procedures worldwide, a tool to predict operative duration could be extremely beneficial to healthcare organisations. Methods: Data collected from the CholeS study on patients undergoing cholecystectomy in UK and Irish hospitals between 04/2014 and 05/2014 were used to study operative duration. A multivariable binary logistic regression model was produced in order to identify significant independent predictors of long (> 90 min) operations. The resulting model was converted to a risk score, which was subsequently validated on second cohort of patients using ROC curves. Results: After exclusions, data were available for 7227 patients in the derivation (CholeS) cohort. The median operative duration was 60 min (interquartile range 45–85), with 17.7% of operations lasting longer than 90 min. Ten factors were found to be significant independent predictors of operative durations > 90 min, including ASA, age, previous surgical admissions, BMI, gallbladder wall thickness and CBD diameter. A risk score was then produced from these factors, and applied to a cohort of 2405 patients from a tertiary centre for external validation. This returned an area under the ROC curve of 0.708 (SE = 0.013, p  90 min increasing more than eightfold from 5.1 to 41.8% in the extremes of the score. Conclusion: The scoring tool produced in this study was found to be significantly predictive of long operative durations on validation in an external cohort. As such, the tool may have the potential to enable organisations to better organise theatre lists and deliver greater efficiencies in care

The Cholecystectomy As A Day Case (CAAD) Score: A Validated Score of Preoperative Predictors of Successful Day-Case Cholecystectomy Using the CholeS Data Set

Background Day-case surgery is associated with significant patient and cost benefits. However, only 43% of cholecystectomy patients are discharged home the same day. One hypothesis is day-case cholecystectomy rates, defined as patients discharged the same day as their operation, may be improved by better assessment of patients using standard preoperative variables. Methods Data were extracted from a prospectively collected data set of cholecystectomy patients from 166 UK and Irish hospitals (CholeS). Cholecystectomies performed as elective procedures were divided into main (75%) and validation (25%) data sets. Preoperative predictors were identified, and a risk score of failed day case was devised using multivariate logistic regression. Receiver operating curve analysis was used to validate the score in the validation data set. Results Of the 7426 elective cholecystectomies performed, 49% of these were discharged home the same day. Same-day discharge following cholecystectomy was less likely with older patients (OR 0.18, 95% CI 0.15–0.23), higher ASA scores (OR 0.19, 95% CI 0.15–0.23), complicated cholelithiasis (OR 0.38, 95% CI 0.31 to 0.48), male gender (OR 0.66, 95% CI 0.58–0.74), previous acute gallstone-related admissions (OR 0.54, 95% CI 0.48–0.60) and preoperative endoscopic intervention (OR 0.40, 95% CI 0.34–0.47). The CAAD score was developed using these variables. When applied to the validation subgroup, a CAAD score of ≤5 was associated with 80.8% successful day-case cholecystectomy compared with 19.2% associated with a CAAD score >5 (p < 0.001). Conclusions The CAAD score which utilises data readily available from clinic letters and electronic sources can predict same-day discharges following cholecystectomy

Efficacy and safety of lisdexamfetamine dimesylate and atomoxetine in the treatment of attention-deficit/hyperactivity disorder:a head-to-head, randomized, double-blind, phase IIIb study

OBJECTIVES: The aim of this study was to compare the efficacy and safety of the prodrug psychostimulant lisdexamfetamine dimesylate (LDX) and the non-stimulant noradrenergic compound atomoxetine (ATX) in children and adolescents with attention-deficit/hyperactivity disorder (ADHD) who had previously responded inadequately to methylphenidate (MPH). METHODS: This 9-week, head-to-head, randomized, double-blind, active-controlled study (SPD489-317; ClinicalTrials.gov NCT01106430) enrolled patients (aged 6-17 years) with at least moderately symptomatic ADHD and an inadequate response to previous MPH therapy. Patients were randomized (1:1) to an optimized daily dose of LDX (30, 50 or 70 mg) or ATX (patients <70 kg, 0.5-1.2 mg/kg with total daily dose not to exceed 1.4 mg/kg; patients ≥70 kg, 40, 80 or 100 mg). The primary efficacy outcome was time (days) to first clinical response. Clinical response was defined as a Clinical Global Impressions-Improvement (CGI-I) score of 1 (very much improved) or 2 (much improved). Secondary efficacy outcomes included the proportion of responders at each study visit and the change from baseline in ADHD Rating Scale (ADHD-RS-IV) and CGI-Severity scores. Tolerability and safety were assessed by monitoring treatment-emergent adverse events (TEAEs), height and weight, vital signs and electrocardiogram parameters. Endpoint was defined as the last post-baseline, on-treatment visit with a valid assessment. RESULTS: Of 267 patients randomized (LDX, n = 133; ATX, n = 134), 200 (74.9%) completed the study. The median time to first clinical response [95% confidence interval (CI)] was significantly shorter for patients receiving LDX [12.0 days (8.0-16.0)] than for those receiving ATX [21.0 days (15.0-23.0)] (p = 0.001). By week 9, 81.7% (95% CI 75.0-88.5) of patients receiving LDX had responded to treatment compared with 63.6% (95% CI 55.4-71.8) of those receiving ATX (p = 0.001). Also by week 9, the difference between LDX and ATX in least-squares mean change from baseline (95% CI) was significant in favour of LDX for the ADHD-RS-IV total score [-6.5 (-9.3 to -3.6); p < 0.001; effect size 0.56], inattentiveness subscale score [-3.4 (-4.9 to -1.8); p < 0.001; effect size 0.53] and the hyperactivity/impulsivity subscale score [-3.2 (-4.6 to -1.7); p < 0.001; effect size 0.53]. TEAEs were reported by 71.9 and 70.9% of patients receiving LDX and ATX, respectively. At endpoint, both treatments were associated with mean (standard deviation) increases in systolic blood pressure [LDX, +0.7 mmHg (9.08); ATX, +0.6 mmHg (7.96)], diastolic blood pressure [LDX, +0.1 mmHg (8.33); ATX, +1.3 mmHg (8.24)] and pulse rate [LDX, +3.6 bpm (10.49); ATX, +3.7 bpm (10.75)], and decreases in weight [LDX, -1.30 kg (1.806); ATX, -0.15 kg (1.434)]. CONCLUSIONS: LDX was associated with a faster and more robust treatment response than ATX in children and adolescents with at least moderately symptomatic ADHD who had previously responded inadequately to MPH. Both treatments displayed safety profiles consistent with findings from previous clinical trials

Thigh-length compression stockings and DVT after stroke

Controversy exists as to whether neoadjuvant chemotherapy improves survival in patients with invasive bladder cancer, despite randomised controlled trials of more than 3000 patients. We undertook a systematic review and meta-analysis to assess the effect of such treatment on survival in patients with this disease