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

Thermostable DNA Polymerase from a Viral Metagenome Is a Potent RT-PCR Enzyme

Viral metagenomic libraries are a promising but previously untapped source of new reagent enzymes. Deep sequencing and functional screening of viral metagenomic DNA from a near-boiling thermal pool identified clones expressing thermostable DNA polymerase (Pol) activity. Among these, 3173 Pol demonstrated both high thermostability and innate reverse transcriptase (RT) activity. We describe the biochemistry of 3173 Pol and report its use in single-enzyme reverse transcription PCR (RT-PCR). Wild-type 3173 Pol contains a proofreading 3′-5′ exonuclease domain that confers high fidelity in PCR. An easier-to-use exonuclease-deficient derivative was incorporated into a PyroScript RT-PCR master mix and compared to one-enzyme (Tth) and two-enzyme (MMLV RT/Taq) RT-PCR systems for quantitative detection of MS2 RNA, influenza A RNA, and mRNA targets. Specificity and sensitivity of 3173 Pol-based RT-PCR were higher than Tth Pol and comparable to three common two-enzyme systems. The performance and simplified set-up make this enzyme a potential alternative for research and molecular diagnostics

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

Depression, psychological distress and Internet use among community-based Australian adolescents: a cross-sectional study

BACKGROUND: There has been rapid increase in time spent using Internet as a platform for entertainment, socialising and information sourcing. This study aimed to evaluate the relationship between duration of time spent using Internet for leisure, depressive symptoms, and psychological distress among Australian adolescents. METHODS: Depressive symptoms were indicated by the youth self-report module from the Diagnostic and Statistical Manual of Mental Disorders Version IV criteria, and psychological distress was measured by Kessler Psychological Distress scale. Internet use was self-reported based on use on an average weekday, and an average weekend day. Multivariate logistic regression models were used to examine the relationship between Internet use and mental health outcomes. Models were adjusted for potential confounders: age; relative level of socio-economic disadvantage, and body mass index. RESULTS: Adolescents were aged 11-17 years (M = 14.5 years, SD = 2.04 years). Greatest time spent using internet (≥7 h a day) was significantly associated with experiencing depressive symptoms among females (OR = 2.09, 95% CI = 1.16, 3.76, p < 0.05), and high/very high levels of psychological distress for male (OR = 2.23, 95% CI = 1.36, 3.65, p < 0.01) and female (OR = 2.38, 95% CI = 1.55, 3.67, p < 0.01) adolescents. CONCLUSIONS: With current initiatives to improve health behaviours among adolescents to improve physical health outcomes such as overweight or obesity, it is imperative that the reciprocal relationship with mental health is known and included in such public health developments. Internet use may interact with mental health and therefore could be a modifiable risk factor to reach and improve mental health outcomes for this age group. Caution is advised in interpretation of findings, with some inconsistencies emerging from this evidence

Biodiversity inventories in high gear: DNA barcoding facilitates a rapid biotic survey of a temperate nature reserve

Comprehensive biotic surveys, or ‘all taxon biodiversity inventories’ (ATBI), have traditionally been limited in scale or scope due to the complications surrounding specimen sorting and species identification. To circumvent these issues, several ATBI projects have successfully integrated DNA barcoding into their identification procedures and witnessed acceleration in their surveys and subsequent increase in project scope and scale. The Biodiversity Institute of Ontario partnered with the rare Charitable Research Reserve and delegates of the 6th International Barcode of Life Conference to complete its own rapid, barcode-assisted ATBI of an established land trust in Cambridge, Ontario, Canada

Mobilization of the non-conjugative plasmid RSF1010: A genetic and DNA sequence analysis of the mobilization region

The entire region required for mobilization of the non-conjugative plasmid RSF1010 has been cloned into a mobilization-deficient pBR322 derivative. The segment of DNA cloned was ∼1.8 kb and included the origin of conjugal DNA transfer (oriT). The DNA sequence of the mobilization region has been determined, and revealed the presence of several overlapping reading frames. The isolation and mapping of both Tn 1725 and BamH1-linker insertions and comparison with the DNA sequence data has allowed the identification of three genes required for mobilization. Two of these genes are overlapping and encode proteins of 16 kDa and >65 kDa (although the truncated protein is functional, the gene extends outside the region cloned). The third gene is transcribed in the opposite direction. Promoters capable of transcribing these genes were located by S1 mapping in the inter-cistronic region between these divergently transcribed genes. The oriT site is located in this region, and the transcriptional patterns observed for mob+ and mob- plasmids implied that the promoters may be regulated by two of the mobilization proteins binding to the oriT site. © 1987 Springer-Verlag