Sex differences in surgical site infections following coronary artery bypass grafting: a retrospective observational study

BACKGROUND

Surgical site infection (SSI) following cardiac surgery poses a significant challenge for healthcare providers. Despite advances in surgical techniques and infection control measures, SSI remains a leading cause of morbidity and mortality, in addition to being a significant economic burden on healthcare services. Current literature suggests there is a reproducible difference in the incidence of SSI following cardiac surgery between sexes. We aim to assess the sex-specific predictive risk factors for sternal SSI following coronary artery bypass grafting (CABG) in addition to identifying any differences in the causative organisms between groups.

METHODS

Adult patients undergoing isolated CABG between January 2012 and December 2022 in one UK hospital organization were included. In this 10-year, retrospective observational study, a total of 10,208 patients met the inclusion criteria. Pre-operative risk factors were identified using univariate analysis. To assess dependence between sex and organism or Gram stain, a Pearson Chi-squared test with Yates correction for continuity was performed.

RESULTS

In total there were 8457 males of which 181 developed a sternal SSI (2.14%) and 1751 females, 128 of whom had a sternal SSI (7.31%). Male patients were found to be significantly more likely to develop an SSI secondary to a Gram-positive organism, whereas female patients were more likely to have a Gram-negative causative organism (P<0.00001). Staphylococcus was statistically more likely to be the causative organism genus in male patients. Pseudomonas aeruginosa was found to be twice as common in the female cohort compared with the male group.

CONCLUSION

In our study, we found a statistically significant difference in the causative organisms and Gram stain for post-CABG sternal SSIs between males and females. Male patients predominately have Gram-positive associated SSIs, whereas female SSI pathogens are more likely to be Gram negative. The preoperative risk profiles of both cohorts are similar, including being an insulin-dependent diabetic and triple vessel coronary artery disease. Given these findings, it prompts the question, should we be tailoring our SSI treatment strategies according to sex and associated risk profiles?

279 Preparing Foundation Trainees for Surgical On-Calls

Aim

Foundation trainee feedback has highlighted low levels of confidence with the prospect of surgical on-calls. Key areas of concern are assessing and managing the acute surgical patient, identifying which patients need an operation and having the technical skills to competently assist in theatre. This lack of confidence prevents trainees engaging in an educational and rewarding rotation. We have designed and facilitated a day of robust workshops, addressing these key educational needs.

Method

Pre and post course questionnaires assessed the efficacy of teaching. Lectures on the assessment and management of acute surgical patients in general surgery, urology and trauma and orthopaedics were delivered by core surgical trainees. A named consultant oversaw quality assurance. Addressing the technical skills development need, an afternoon of surgical skills workshops covered, suturing, knot tying, laparoscopic principles, and theatre etiquette. Small groups of trainees rotated through each workshop, delivered by senior specialty trainee registrars, to ensure high fidelity training

Results

Trainees rated themselves in key areas pre and post course on a scale from 1-5. Pre course, 66% of trainees scored 3+ in “confidence in managing a surgical patient on-call”. This rose to 100% post course. Similarly; “Confidence in decision making regarding whether a patient should proceed to theatre” increased from 37.5% to 93.7%. “Suturing skills” improved from 37.5% to 100%.

Conclusions

All trainees that attended the course displayed marked improvement in their confidence and competence. We feel this course or similar should be incorporated into the foundation teaching program locally and has scope to be expanded regionally.

Evaluation of 4 predictive algorithms for intramammary infection status in late-lactation cows

The objective of this observational study was to compare 4 cow-level algorithms to predict cow-level intramammary infection (IMI) status (culture and MALDI-TOF) in late-lactation US dairy cows using standard measures of test performance. Secondary objectives were to estimate the likely effect of each algorithm, if used to guide selective dry cow therapy (SDCT), on dry cow antibiotic use in US dairy herds, and to investigate the importance of including clinical mastitis criteria in algorithm-guided SDCT. Cows (n = 1,594) from 56 US dairy herds were recruited as part of a previously published cross-sectional study of bedding management and IMI in late-lactation cows. Each herd was visited twice for sampling. At each farm visit, aseptic quarter-milk samples were collected from 20 cows approaching dry-off (>180 d pregnant), which were cultured using standard bacteriological methods and MALDI-TOF for identification of isolates. Quarter-level culture results were used to establish cow-level IMI status, which was considered the reference test in this study. Clinical mastitis records and Dairy Herd Improvement Association test-day somatic cell count data were extracted from herd records and used to perform cow-level risk assessments (low vs. high risk) using 4 algorithms that have been proposed for SDCT in New Zealand, the Netherlands, United Kingdom, and the United States. Agreement between aerobic culture (reference test; IMI vs. no-IMI) and algorithm status (high vs. low risk) was described using Cohen's kappa, test sensitivity, specificity, negative predictive value, and positive predictive value. The proportion of cows classified as high risk among the 4 algorithms ranged from 0.31 to 0.63, indicating that these approaches to SDCT could reduce antibiotic use at dry-off by 37 to 69% in the average US herd. All algorithms had poor agreement with IMI status, with kappa values ranging from 0.05 to 0.13. Sensitivity varied by pathogen, with higher values observed when detecting IMI caused by Streptococcus uberis, Streptococcus dysgalactiae, Staphylococcus aureus, and Lactococcus lactis. Negative predictive values were high for major pathogens among all algorithms (≥0.87), which may explain why algorithm-guided SDCT programs have been successfully implemented in field trials, despite poor agreement with overall IMI status. Removal of clinical mastitis criteria for each algorithm had little effect on the algorithm classification of cows, indicating that algorithms based on SCC alone may have similar performance to those based on SCC and clinical mastitis criteria. We recommend that producers implementing algorithm-guided SDCT use algorithm criteria that matches their relative aspirations for reducing antibiotic use (high specificity, positive predictive value) or minimizing untreated IMI at dry-off (high sensitivity, negative predictive value).

Postcalving udder health and productivity in cows approaching dry-off with intramammary infections caused by non-aureus Staphylococcus, Aerococcus, Enterococcus, Lactococcus, and Streptococcus species

The objective of this prospective cohort study was to explore associations between intramammary infection (IMI) in late-lactation cows and postcalving udder health and productivity. Cows (n = 2,763) from 74 US dairy herds were recruited as part of a previously published cross-sectional study of bedding management and IMI in late-lactation cows. Each herd was visited twice for sampling. At each visit, aseptic quarter milk samples were collected from 20 cows approaching dry-off (>180 d pregnant), which were cultured using standard bacteriological methods and MALDI-TOF for identification of isolates. Quarter-level culture results were used to establish cow-level IMI status at enrollment. Cows were followed from enrollment until 120 d in milk (DIM) in the subsequent lactation. Herd records were used to establish whether subjects experienced clinical mastitis or removal from the herd, and DHIA test-day data were used to record subclinical mastitis events (somatic cell count >200,000 cells/mL) and milk yield (kg/d) during the follow-up period. Cox regression and generalized estimating equations were used to evaluate the associations between IMI and the outcome of interest. The presence of late-lactation IMI caused by major pathogens was positively associated with postcalving clinical mastitis [hazard ratio = 1.5, 95% confidence interval (CI): 1.2, 2.0] and subclinical mastitis (risk ratio = 1.5, 95% CI: 1.3, 1.9). Species within the non-aureus Staphylococcus (NAS) group varied in their associations with postcalving udder health, with some species being associated with increases in clinical and subclinical mastitis in the subsequent lactation. Late-lactation IMI caused by Streptococcus and Streptococcus (Strep)-like organisms, other than Aerococcus spp. (i.e., Enterococcus, Lactococcus, and Streptococcus spp.) were associated with increases in postcalving clinical and subclinical mastitis. Test-day milk yield from 1 to 120 DIM was lower (-0.9 kg, 95% CI: -1.6, -0.3) in late-lactation cows with any IMI compared with cows without IMI. No associations were detected between IMI in late lactation and risk for postcalving removal from the herd within the first 120 DIM. Effect estimates reported in this study may be less than the underlying quarter-level effect size for IMI at dry-off and postcalving clinical and subclinical mastitis, because of the use of late-lactation IMI as a proxy for IMI at dry-off and the use of cow-level exposure and outcome measurements. Furthermore, the large number of models run in this study (n = 94) increases the chance of identifying chance associations. Therefore, confirmatory studies should be conducted. We conclude that IMI in late lactation may increase risk of clinical and subclinical mastitis in the subsequent lactation. The relationship between IMI and postcalving health and productivity is likely to vary among pathogens, with Staphylococcus aureus, Streptococcus spp., Enterococcus spp., and Lactococcus spp. being the most important pathogens identified in the current study.

A change in perspective to see the bigger picture. A thematic analysis of Audit and Quality Improvement submissions to the last seven UK based SAM Conferences

AIMS

To create a profile of Society for Acute Medicine (SAM) Audit and Quality Improvement (A&QI) accepted abstracts from the last seven UK based conferences.

METHODOLOGY

The profile elements for 380 SAM A&QI abstracts accepted for poster presentation were compiled from their respective conference programme booklets. Abstracts were classified into 30 categories based on key themes. Further sub-categorisation of abstracts was based on secondary detail of the submissions. Data was analysed with Pareto charts.

FINDINGS

The majority of submissions were covered by a small representation of themes, with 30% of category themes covering 80% of A&QI abstracts. There is a repetitive trend of theme categories across all the conferences.

Cross-sectional study of the relationship between cloth udder towel management, towel bacteria counts, and intramammary infection in late-lactation dairy cows

Because cloth udder towels (CUT) may function as a fomite for mastitis-causing pathogens, most udder health laboratories offer towel culture services as a tool to monitor towel hygiene. However, no studies have investigated if an association exists between bacteria levels in CUT and udder health outcomes. The objectives of this cross-sectional study were to (1) describe associations between herd-level measures of towel bacteria count (ToBC) and quarter-level intramammary infection (IMI) status in late-lactation cows, (2) establish pathogen-specific target levels of bacteria in CUT to aid the interpretation of towel culture reports, and (3) identify laundering-related risk factors for high ToBC. The study was conducted in 67 herds from 10 dairy states in the United States that used CUT. These 67 herds were originally recruited as part of a larger (80 herd) cross-sectional study of bedding management. Each herd was visited once during December 2017 to April 2018 and quarter-milk samples (n = 4,656) were collected from late-gestation (>180 d pregnant) cows (n = 1,313). Two recently laundered CUT were collected and a questionnaire was used to collect information about pre-milking teat preparation and CUT management practices. Quarter-level IMI status was determined using standard bacteriologic methods. In addition, colony-forming units of all bacteria (total bacteria), Staphylococcus spp., Streptococcus spp. or Streptococcus-like organisms (SSLO), coliforms, noncoliform gram-negatives, and Bacillus spp. were determined for each pair of CUT (log₁₀ cfu/cm²). The association between ToBC and IMI was determined using multivariable logistic regression with mixed effects. After dichotomizing ToBC into high and low categories, associations between towel management practices and ToBC category were determined using unconditional logistic regression. The quarter-level prevalence of IMI was 19.6%, which was predominantly caused by non-aureus Staphylococcus spp. (NAS; 10.2%) and SSLO (5.1%). The predominant bacteria in CUT were Bacillus spp. (median = 3.13 log₁₀ cfu/cm²). Total bacteria count was not associated with odds of IMI (odds ratio = 1.06), likely due to the predominance of Bacillus spp. in CUT and low number of IMI caused by Bacillus spp. In contrast, counts of Staphylococcus spp. and SSLO were positively associated with odds of IMI caused by NAS (odds ratio = 1.33) and SSLO (odds ratio = 1.45), respectively. Of 12 CUT management practices evaluated, only the failure to use a dryer was identified as a clear predictor of risk for a high ToBC (risk ratio of high coliform count = 8.17). Our study findings suggest that CUT may act as a fomite for NAS and SSLO. We recommend that herds aim to keep counts of Staphylococcus spp. and SSLO in CUT below 32 cfu/cm² (or 5 cfu/in²), and that laundered towels be completely dried in a hot air dryer.

Cross-sectional study of the relationships among bedding materials, bedding bacteria counts, and intramammary infection in late-lactation dairy cows

Objectives of this study were to (1) describe the intramammary infection (IMI) prevalence and pathogen profiles in quarters of cows approaching dry-off in US dairy herds, (2) compare IMI prevalence in quarters of cows exposed to different bedding material types, and (3) identify associations between bedding bacteria count and IMI in cows approaching dry-off. Eighty herds using 1 of 4 common bedding materials (manure solids, organic non-manure, new sand, and recycled sand) were recruited in a multi-site cross-sectional study. Each herd was visited twice for sampling. At each visit, aseptic quarter-milk samples were collected from 20 cows approaching dry-off (>180 d pregnant). Samples of unused and used bedding were also collected. Aerobic culture was used to determine the IMI status of 10,448 quarters and to enumerate counts (log₁₀ cfu/mL) of all bacteria, Staphylococcus spp., Streptococcus spp. and Streptococcus-like organisms (SSLO), coliforms, Klebsiella spp., noncoliform gram-negatives, Bacillus spp., and Prototheca spp. in unused (n = 148) and used (n = 150) bedding. The association between bedding bacteria count and IMI was determined using multivariable logistic regression with mixed effects. Quarter-level prevalence of IMI was 21.1%, which was primarily caused by non-aureus Staphylococcus spp. (11.4%) and SSLO (5.6%). Only modest differences in IMI prevalence were observed between the 4 common bedding material types. Counts of all bacteria in unused bedding was positively associated with odds of IMI caused by any pathogen [ALL-IMI; odds ratio (OR) = 1.08]. A positive association was also observed for counts of SSLO in unused bedding and SSLO-IMI (OR = 1.09). These patterns of association were generally consistent across the 4 common bedding materials. In contrast, the association between counts of all bacteria in used bedding and ALL-IMI varied by bedding type, with positive associations observed in quarters exposed to manure solids (OR = 2.29) and organic non-manure (OR = 1.51) and a negative association in quarters exposed to new sand (OR = 0.47). Findings from this study suggest that quarter-level IMI prevalence in late-lactation cows is low in US dairy herds. Furthermore, bedding material type may not be an important risk factor for IMI in late lactation. Higher levels of bacteria in bedding may increase IMI prevalence at dry-off in general, but this relationship is likely to vary according to bedding material type.

The diagnosis and management of respiratory tract fungal infection in cystic fibrosis: A UK survey of current practice

Aspergillus fumigatus is commonly found in the airways of patients with cystic fibrosis (CF), and allergic bronchopulmonary aspergillosis (ABPA) is the most recognized associated clinical condition. However, accurate diagnosis remains challenging, and there is a paucity of clinical trials to guide clinical management of fungal disease. The aim of this survey was to assess the variability in current practice across the UK in diagnosis and management of fungal lung disease in CF patients. A 21 question anonymous online survey was sent to 94 paediatric and adult CF consultants in the UK. The response rate was 60.6% (32 adult physicians, 25 pediatricians) with 55 full and 2 partially completed surveys. For a first diagnosis of ABPA 20 (35.1%) treat with prednisolone alone, 38 (66.7%) use prednisolone with itraconazole and 2 (3.5%) choose voriconazole. Only 5 (8.8%) treat with prednisolone alone for a 1st relapse, 33 (58%) used prednisolone with itraconazole. To reduce treatment, 21 (36.8%) decrease steroids to zero over time and maintain azole therapy, 18 (31.6%) stop the azole and steroid after a fixed time, and 5 (8.8%) stop the azole after a fixed time and maintain a small steroid dose. Thirty-eight (66.7%) respondents believe Aspergillus colonization of the airway can cause clinical deterioration, and 37 (66.1%) would treat this. Scedosporium apiospermum infection has been diagnosed and treated by 35 (61.4%) of respondents. Results of this survey highlight the variance in clinical practice and the limited evidence available to guide management of fungal infection in CF.

Associations between urinary organophosphate ester metabolites and measures of adiposity among U.S. children and adults: NHANES 2013-2014

BACKGROUND

Organophosphate esters (OPEs) are synthetic chemicals found in many consumer products, including furniture, electronics, processed foods, and building materials. Emerging in vitro and in vivo studies suggest that OPEs are metabolism disrupting compounds; however, epidemiologic studies investigating their associations with adiposity markers are sparse.

OBJECTIVE

We examined cross-sectional associations between OPE biomarkers and adiposity measures among U.S. children and adults participating in the National Health and Nutrition Examination Survey (NHANES: 2013-2014).

METHODS

Concentrations of five OPE metabolites were quantified in urine: diphenyl phosphate (DPHP), bis(1,3-dichloro-2-propyl) phosphate (BDCPP), bis(2-chloroethyl) phosphate (BCEP), dibutyl phosphate (DBUP), and bis(1-chloro-2-propyl) phosphate (BCPP). We conducted covariate-adjusted logistic and linear regressions to examine associations between log2-transformed and dichotomized OPE metabolite concentrations and obesity, body mass index (BMI), and waist circumference (WC), separately among 784 children (6-19 years) and 1672 adults (≥20 years). We also assessed heterogeneity of associations by sex.

RESULTS

DBUP concentrations were inversely associated with the prevalence odds of being obese vs. normal weight in children (adjusted Prevalence Odds Ratio, aPOR: 0.82, 95% Confidence Interval, 95% CI: 0.70, 0.95) and adults (aPOR: 0.83, 95% CI: 0.72, 0.96). DBUP was also significantly associated with lower BMI z-scores (β:-0.08, 95% CI:-0.17, 0.01) and WC (β:-0.71, 95% CI: -1.49, 0.07) in children. BCEP concentrations were associated with increased prevalence odds of being overweight vs. normal weight (aPOR: 1.15, 95% CI: 1.01, 1.32) among children; similar, albeit not statistically significant, relationships were observed with other child adiposity outcomes. Among adults, detectable BCPP concentrations were associated with increased prevalence odds of being obese vs. normal weight (aPOR: 1.70, 95% CI: 1.21, 2.38) and having a high vs. normal WC (aPOR: 1.51, 95% CI: 1.11, 2.07) as well as higher BMI (β: 1.31, 95% CI: 0.30, 2.33). Other OPE metabolites were not consistently associated with adiposity measures among adults. Although associations of BCPP exposure with adiposity outcomes were generally inverse among boys, but not girls, we did not observe consistent evidence of sexually-dimorphic associations for other OPE metabolites.

CONCLUSIONS

Exposure to select OPEs may be differentially associated with body size among children and adults. Given the cross-sectional design of the present study, future prospective studies are needed to confirm these findings.

An Easy Method of Mentally Estimating the Metabolic Component of Acid/base Balance Using the Fencl-Stewart Approach

The Stewart approach defines acid/base abnormalities as resulting from changes in PCO 2, strong ion difference (SID), and weak acids (mainly albumin) but needs a computer for calculation. The base excess (BE) is a measure of the net effect of changes in SID and weak acids, therefore, metabolic acid/base balance can be described as BE effects of their change from normal.

We compared our mental estimation of BE effects with the more complex calculation.

Acid/base abnormalities were identified in 44 critically ill patients. The BE effects of change in strong ions, change in albumin, and the BE-gap (“other species” or unmeasured anion effect) were calculated using standard equations. An estimate of the BE effects was determined. The difference between SID (using [Na + ]+[K+ ]-([Cl]+lactate)) and normal SID (42 mEq/l) estimated the effect of a change in SID. The effect of a change of albumin from normal was estimated as 0.252 (normal albumin-measured albumin). The predicted BE was defined as estimated change in SID plus albumin effect. The estimated BE-gap (BE-gap est ) was actual BE minus predicted BE. The Bland-Altman method was used to test agreement.

Calculations were made on 46 data sets from 44 individuals. The bias (limits of agreement) for calculated and estimated strong ion effects, calculated and estimated albumin effect, and calculated and estimated BE-gap were -1.26 (-3.14 to 0.66) mEq/l, 0.5 (-0.05 to 1.05) mEq/l, and 0.76 (-1.27 to 2.79) mEq/l respectively. However the bias (limits of agreement) for BE-gap and BE-gap est and strong ion gap were poor, being 1.1 (-4 to 14) mEq/l and 0.4 (-9.2 to 10) mEq/l respectively.

The BE-gap and BE-gap est are unsuitable to quantify gap ions. However, our easy-to-perform estimation has a clinically acceptable bias compared to calculated BE effects and is a simple method for identifying the components of acid/base abnormalities.

Beyond the expected: Identifying broad research priorities of researchers and the cystic fibrosis community

The Cystic Fibrosis Foundation (CFF) supports research programs aimed at improving care and building a successful drug development pipeline. To ensure its research agenda meets the needs of the community it serves, the CFF sought community input into clinical research prioritization for topics not well-known as already being addressed by CFF-funded research. In 2018, clinical researchers, adults with CF, and family members were surveyed about a broad range of research topics that are perceived to receive less attention. We compared responses from researchers (n = 19) and community members (n = 135) and found groups aligned on their top three research priorities: 1) respiratory microorganism detection and treatment, 2) mental health, and 3) reducing treatment burden. We also explored whether or not those priorities align with the CFF research portfolio. Cognizance of researcher and community priorities can help inform clinical research endeavors to improve the health and well-being of people affected by CF.

Extensibility Characteristics of the Human Cheek: A Pilot Study

Force displacement curves of the cheek in an edentulous area in the maxillary bicuspid-molar region on ten adults evidenced three segments: a power function, a plateau, and an exponential function. The plateau suggested an area in which the cheek could be displaced with no increase in force. The resting force was 1.54 g to 4.61 g. The cheek can be modeled by a fluid-filled double elastic membrane system.

Preoperative endoscopy may reduce the need for revisional surgery for gastro-oesophageal reflux disease following laparoscopic sleeve gastrectomy

Laparoscopic sleeve gastrectomy is a safe and effective bariatric operation, but postoperative reflux symptoms can sometimes necessitate revisional surgery. Roux-en-Y gastric bypass is the preferred operation in morbidly obese patients with gastro-oesophageal reflux disease. In 2011, we introduced preoperative endoscopy to assess for hiatus hernia or evidence of oesophagitis in conjunction with an assessment of gastro-oesophageal reflux symptoms for all patients undergoing bariatric surgery with a view to avoid sleeve gastrectomy for these patients. A prospectively maintained database was used to identify patients who underwent sleeve gastrectomy before and after we changed the unit policy. The need for revisional surgery in patients with troublesome gastro-oesophageal reflux disease was examined. Prior to 2011, 130 patients underwent sleeve gastrectomy, and 11 (8.5%) of them required conversion to Roux-en-Y gastric bypass for symptomatic reflux disease. Following the policy change, 284 patients underwent sleeve gastrectomy, and to date, only five (1.8%) have required revisional surgery (p = 0.001). Baseline demographics were comparable between the groups, and average follow-up period was 47 and 33 months, respectively, for each group. Preoperative endoscopy and a detailed clinical history regarding gastro-oesophageal reflux symptoms may improve patient selection for sleeve gastrectomy. Avoiding sleeve gastrectomy in patients with reflux disease and/or hiatus hernia may reduce the incidence of revisional surgery.

GW151226: Observation of Gravitational Waves from a 22-Solar-Mass Binary Black Hole Coalescence

We report the observation of a gravitational-wave signal produced by the coalescence of two stellar-mass black holes. The signal, GW151226, was observed by the twin detectors of the Laser Interferometer Gravitational-Wave Observatory (LIGO) on December 26, 2015 at 03:38:53 UTC. The signal was initially identified within 70 s by an online matched-filter search targeting binary coalescences. Subsequent off-line analyses recovered GW151226 with a network signal-to-noise ratio of 13 and a significance greater than 5σ. The signal persisted in the LIGO frequency band for approximately 1 s, increasing in frequency and amplitude over about 55 cycles from 35 to 450 Hz, and reached a peak gravitational strain of 3.4_{-0.9}^{+0.7}×10^{-22}. The inferred source-frame initial black hole masses are 14.2_{-3.7}^{+8.3}M_{⊙} and 7.5_{-2.3}^{+2.3}M_{⊙}, and the final black hole mass is 20.8_{-1.7}^{+6.1}M_{⊙}. We find that at least one of the component black holes has spin greater than 0.2. This source is located at a luminosity distance of 440_{-190}^{+180}  Mpc corresponding to a redshift of 0.09_{-0.04}^{+0.03}. All uncertainties define a 90% credible interval. This second gravitational-wave observation provides improved constraints on stellar populations and on deviations from general relativity.

Properties of the Binary Black Hole Merger GW150914

On September 14, 2015, the Laser Interferometer Gravitational-Wave Observatory (LIGO) detected a gravitational-wave transient (GW150914); we characterize the properties of the source and its parameters. The data around the time of the event were analyzed coherently across the LIGO network using a suite of accurate waveform models that describe gravitational waves from a compact binary system in general relativity. GW150914 was produced by a nearly equal mass binary black hole of masses 36_{-4}^{+5}M_{⊙} and 29_{-4}^{+4}M_{⊙}; for each parameter we report the median value and the range of the 90% credible interval. The dimensionless spin magnitude of the more massive black hole is bound to be <0.7 (at 90% probability). The luminosity distance to the source is 410_{-180}^{+160}  Mpc, corresponding to a redshift 0.09_{-0.04}^{+0.03} assuming standard cosmology. The source location is constrained to an annulus section of 610  deg^{2}, primarily in the southern hemisphere. The binary merges into a black hole of mass 62_{-4}^{+4}M_{⊙} and spin 0.67_{-0.07}^{+0.05}. This black hole is significantly more massive than any other inferred from electromagnetic observations in the stellar-mass regime.

Tests of General Relativity with GW150914

The LIGO detection of GW150914 provides an unprecedented opportunity to study the two-body motion of a compact-object binary in the large-velocity, highly nonlinear regime, and to witness the final merger of the binary and the excitation of uniquely relativistic modes of the gravitational field. We carry out several investigations to determine whether GW150914 is consistent with a binary black-hole merger in general relativity. We find that the final remnant's mass and spin, as determined from the low-frequency (inspiral) and high-frequency (postinspiral) phases of the signal, are mutually consistent with the binary black-hole solution in general relativity. Furthermore, the data following the peak of GW150914 are consistent with the least-damped quasinormal mode inferred from the mass and spin of the remnant black hole. By using waveform models that allow for parametrized general-relativity violations during the inspiral and merger phases, we perform quantitative tests on the gravitational-wave phase in the dynamical regime and we determine the first empirical bounds on several high-order post-Newtonian coefficients. We constrain the graviton Compton wavelength, assuming that gravitons are dispersed in vacuum in the same way as particles with mass, obtaining a 90%-confidence lower bound of 10^{13}  km. In conclusion, within our statistical uncertainties, we find no evidence for violations of general relativity in the genuinely strong-field regime of gravity.

Mini Gastric Bypass: first report of 125 consecutive cases from United Kingdom

Mini Gastric Bypass is a promising bariatric procedure with multiple apparent benefits. Ours is the first unit within the National Health Service of the United Kingdom to be routinely performing this procedure. This retrospective cohort study reports our experience with first 125 procedures. Data were retrospectively analysed from a prospective database. Information was further supplemented by interviewing team members, contacting patients' general practitioners and telephonic follow-up. The mean follow-up was 11.4 months. There were 86 (68.8%) females and the mean age was 45 (range 20-70) years. Mean weight and body mass index was 135.8 (range 85-244) kilograms and 48.1 (range 34.5-73.8) kg m(-2) , respectively. The mean operating time was 92.4 (range 45-150) minutes and the mean post-operative hospital stay was 2.2 (range 2-17) days. There was no leak, one 30-day reoperation and no mortality in this study. Three patients required late reoperations and four patients developed marginal ulcers. At 6 months follow-up (n = 114), 27.5 (range 11.4-47.4) % total body weight loss and 60.1 (range 23.2-117.5) % excess body weight loss was seen. The figures at 12 months follow-up (n = 65) were 36.8 (range 23.7-55.4) % and 79.5 (range 44.9-138.3) %, respectively. This study demonstrates early safety and efficacy of Mini Gastric Bypass in a carefully selected British obese population in a high-volume centre.

Postnatal MRI Brain in Infants Treated for Twin-Twin Transfusion Syndrome

Untreated twin-twin transfusion syndrome (TTTS) is associated with significant mortality and neurological impairment. Fetoscopic laser surgery (FLS) is the treatment of choice. We sought to assess intracranial abnormalities in TTTS twins following treatment. In this prospective, blinded study MRI scans were performed on 3 groups; (1) monochorionic diamniotic (MCDA) twins with TTTS who had undergone FLS (n = 10), (2) MCDA twins without TTTS (n = 8) and (3) dichorionic twins (n = 8). Scans were scored as either normal or abnormal. The primary outcome was a composite of abnormal MRI brain or intrauterine fetal demise. The primary outcome occurred in 6/10 (60%) of the TTTS group versus 3/8 (37.5%) in the MCDA group. The primary outcome was significantly different across all study groups [p = 0.029; X2 = 7.112]. We found that twins treated for TTTS are more likely to have abnormalities on MRI brain at term than other twin groups. This group merits term-corrected MRI as part of their postnatal assessment.

Autoantibodies are not Predictive Markers for the Development of Depressive Symptoms in a Population-Based Cohort of Older Adults

Background

Autoantibodies have been implicated in the etiologic pathway of depressive disorders. Here, we determine the association between the presence of a panel of autoantibodies at baseline and change in depression symptom score over 5-year follow-up in a cohort of healthy elderly Australians.

Methods

Serum samples from 2049 randomly selected subjects enrolled in the Hunter Community Study (HCS) aged 55–85 years were assayed for a range of autoimmune markers (anti-nuclear autoantibodies, extractable nuclear antigen autoantibodies, anti-neutrophil cytoplasmic autoantibodies, thyroid peroxidase autoantibodies, tissue transglutaminase autoantibodies, anti-cardiolipin autoantibodies, rheumatoid factor and cyclic citrullinated peptide autoantibodies) at baseline. Depression symptom score was assessed using the Centre for Epidemiological Study (CES-D) scale at baseline and 5 years later.

Results

Autoantibody prevalence varied amongst our sample with ANA being the most prevalent; positive in 16% and borderline in 36% of study population. No evidence for a relationship was found between change in CES-D score over time and any autoimmune marker. Statins and high cholesterol were significantly associated with change in CES-D score over time in univariate analysis; however, these were probably confounded since they failed to remain significant following multivariable analysis.

Conclusions

Autoantibodies were not associated with change in CES-D score over time. These findings point to an absence of autoimmune mechanisms in the general population or in moderate cases of depression.

Methylation differences at the HLA-DRB1 locus in CD4+ T-Cells are associated with multiple sclerosis

BACKGROUND

Multiple sclerosis (MS) is thought to be caused by T-cell mediated autoimmune dysfunction. Risk of developing MS is influenced by environmental and genetic factors. Modifiable differences in DNA methylation are recognized as epigenetic contributors to MS risk and may provide a valuable link between environmental exposure and inherited genetic systems.

OBJECTIVES AND METHODS

To identify methylation changes associated with MS, we performed a genome-wide DNA methylation analysis of CD4+ T cells from 30 patients with relapsing-remitting MS and 28 healthy controls using Illumina 450K methylation arrays.

RESULTS

A striking differential methylation signal was observed at chr. 6p21, with a peak signal at HLA-DRB1. After prioritisation, we identified a panel of 74 CpGs associated with MS in this cohort. Most notably we found evidence of a major effect CpG island in DRB1 in MS cases (pFDR < 3 × 10(-3)). In addition, we found 55 non-HLA CpGs that exhibited differential methylation, many of which localise to genes previously linked to MS.

CONCLUSIONS

Our findings provide the first evidence for association of DNA methylation at HLA-DRB1 in relation to MS risk. Further studies are now warranted to validate and understand how these findings are involved in MS pathology.

The relationship of distance from the surgical centre on attendance and weight loss after laparoscopic gastric bypass surgery in the United Kingdom

Obesity remains a significant worldwide health problem and is currently increasing. Surgery remains the only proven long-term intervention and has been shown to be cost-effective. Evidence suggests that regular follow-up following laparoscopic adjustable gastric banding is related to improved outcome, such evidence is lacking for laparoscopic gastric bypass surgery (laparoscopic Roux-en-Y gastric bypass [LRYGB]). This study examines the effect of distance on attendance at post-operative clinics and subsequent weight loss following surgery. A prospectively maintained database was interrogated to analyze patients undergoing LRYGB before August 2010. Patient demographics, percentage excess weight loss (%EWL), compliance with out-patient clinic attendances and the distance the patients lived from the hospital were examined. Perfect clinic attendees were compared with non-attendees and the distances patients lived from the hospital evaluated. There was a significantly greater %EWL at 1 year post-op observed in the perfect attendees group (65.5 vs. 59.5, P = 0.01). Increased %EWL was also evident at 2 years post-op but did not reach statistical significance (66.9 vs. 59.5, P = 0.06). There was a negative correlation observed between post-operative weight loss and distance from the bariatric centre (R = -0.21, P = 0.04). Close follow-up following LRYGB is essential to optimize outcomes. Increased frequency of out-patient clinic visits was associated with improved post-operative weight loss. Increasing distance between the patient's home and the bariatric centre was associated with worse post-operative weight loss.

Laparoscopic adjustable gastric band survival in a high-volume bariatric unit

Background

Although laparoscopic adjustable gastric bands (LAGBs) have been shown to be efficacious, their long-term usefulness has been questioned. This study examined the fate of LAGBs in a unit with over a decade of experience in their use. Patient factors related to the need for, and timing of, band removal were investigated.

Methods

A prospectively maintained database was used to identify all patients with a LAGB. Patient demographics, need for band removal and band survival were examined. Logistic regression modelling was done and Kaplan–Meier curves were calculated for band survival.

Results

Between 2000 and 2012, 674 bands were placed in 665 patients. Of these, 143 (21·2 per cent) were removed. There was no difference in rates of removal by sex (P = 0·910). The highest rates of removal were in patients aged less than 40 years (26·7 per cent), and those with a BMI greater than 60 kg/m2 (28·6 per cent). Earlier band removal was seen in younger patients (P = 0·002). Rates of removal increased linearly by earlier year of placement. Of bands placed 4 or more years previously, 35·0 per cent required removal. Eighty-three patients (58·0 per cent) who had a LAGB removed went on to have a further bariatric procedure (band to bypass, 66; band to sleeve, 17).

Conclusion

Even in experienced hands LAGB does not appear to be a definitive solution. In a large number of patients there appears to be a finite ‘band life’, with the majority of patients requiring conversion to a further bariatric procedure.

Presented in part to a meeting of the British Obesity and Metabolic Surgery Society, Glasgow, UK, January 2013, as an oral presentation for which it was awarded the council prize; published in abstract form as Br J Surg 2013; 100(Suppl 3): 2

Laparoscopic adjustable gastric banding: a 10-year single-centre experience of 575 cases with weight loss following surgery

BACKGROUND

Laparoscopic adjustable gastric banding (LAGB) is one of the commonest bariatric procedures in the UK. This study reports our experience with this procedure over the last 10 years.

METHODS

A prospectively maintained database of all the patients undergoing LAGB at our centre between March 2000 and August 2010 was analysed.

RESULTS

Five hundred seventy-five patients underwent LAGB at our centre. There was no mortality in this series. Early (30-day) morbidity rate was 2.2 %. Late complications (20 %) comprised: 78 repositioning of the inflation port in 65 patients, repositioning of band in 24 patients (4 %), removal of band in 20 patients (3.4 %), conversion to bypass in 41 patients (7 %), diagnostic laparoscopy in 1 patient and subtotal gastrectomy in 1 patient. Median follow-up was 29 months. The median of percentage of weight loss (%WL) and excess body weight loss (EBWL) was 18.3 and 40 %, respectively, at ≥ 5 years post-LAGB. Patients with body mass index (BMI) over 50 kg/m(2) were compared to those with BMI ≤ 50 kg/m(2). No significant difference was noted in the weight loss between both of these groups. No significant difference was noted with regards to weight loss between patients <60 and >60 years of age.

CONCLUSIONS

In this cohort of patients, %WL and EBWL were 18.3 and 40 % ≥ 5 years after LAGB, respectively, and early and late complication rates were 2.2 and 20 %, respectively. Majority of late complications were in the first 100 patients. Multifactorial causes included the surgical learning curve and patient selection process.

Routine group and save unnecessary for gastric band surgery: a retrospective case review audit of 1018 bariatric patients

What is already known about this subject •  The demand for bariatric surgery is increasing. •  NHS Trusts are expected to instigate cost-efficiency measures. •  Previous articles have discussed the need for routine preoperative cross-match. What this study adds •  No gastric band patient suffered a significant drop in haemoglobin or needed a blood transfusion. •  Group and save samples could be safely stored in the laboratory and only sent for analysis if clinically indicated. •  Even greater cost savings could be achieved if prudent use of perioperative blood testing and blood transfusion was implemented.

SUMMARY

Current guidance at our Trust is that all bariatric surgical patients should have preoperative group and save (G&S) and full blood count (FBC) tests, as well as a FBC check 1 d post-operatively. Our aim was to investigate blood transfusion requirements of these patients and whether we could reduce the number of investigations requested. 1018 consecutive elective laparoscopic gastric band and laparoscopic Roux-en-Y gastric bypass patients who were operated on in our bariatric unit from March 2000 until January 2011 were identified. Patients' haemoglobin levels, G&S status and blood transfusion requirements were analyzed using our online pathology system. 607 patients had a laparoscopic gastric band, with 411 undergoing a laparoscopic Roux-en-Y gastric bypass. None of our gastric band patients required a transfusion; however, nine patients (2.2%) undergoing a gastric bypass needed a transfusion. Two patients required transfusion within 24 h of surgery while six of the remaining seven patients received blood 3-4 d post-operatively. Costs incurred on FBC and G&S tests during this time were estimated to exceed £15 700. G&S and post-operative FBC tests could be abandoned for laparoscopic gastric band patients with significant financial and person-time savings. However, given that 2.2% of laparoscopic Roux-en-Y gastric bypass patients needed a blood transfusion, we believe that post-operative FBC tests are still warranted in this patient group, with a G&S sample stored in pathology. Much greater financial savings could be achieved if prudent use of preoperative investigations, including storing G&S samples in the laboratory, was adopted for all elective operations.

Psychosocial health care needs assessment of adult cancer patients: a consensus-based guideline

PURPOSE

Although recommended as an essential part of cancer care, there is limited evidence regarding the optimum approach to psychosocial health care needs assessment in this setting. To address this gap, the Cancer Journey Action Group of the Canadian Partnership Against Cancer (CPAC) and the Canadian Association of Psychosocial Oncology (CAPO) partnered to develop consensus-based recommendations regarding the routine assessment of psychosocial and supportive care needs. The purpose of this paper is to summarize the evidence that informed the guideline and disseminate the recommendations developed by the expert panel.

METHODS

Clinical practice recommendations were developed by a panel comprised of psychosocial and interdisciplinary experts. Recommendations were informed by a review of oncology clinical practice guidelines, systematic reviews, and primary research, through to May 2008. Following expert consensus on the recommendations, the clinical practice guideline was externally reviewed by a purposively selected sample of national and international interdisciplinary experts.

RESULTS

A total of nine clinical practice guidelines, three systematic reviews, and 14 primary studies were included in the review. Overall, this body of literature suggested that routine collection of psychosocial health care data has an influence on communication with oncologists and other study specific outcomes, but the evidence was limited by heterogeneity and methodological limitations. Based on the interpretation of this body of evidence by clinical experts, research methodologists, and external reviewers, 12 substantive recommendations were developed regarding the process and parameters of psychosocial needs assessment in adult cancer patients.

CONCLUSION

Given the limitations in the current body of evidence, there remains a need for rigorous empirical research regarding the optimal approach to psychosocial needs assessment, including the specific characteristics that influence effectiveness on patient outcomes. This guideline fills an important gap in psychosocial care, regarding the routine assessment of psychosocial health care needs.

Directional limits on persistent gravitational waves using LIGO S5 science data

The gravitational-wave (GW) sky may include nearby pointlike sources as well as stochastic backgrounds. We perform two directional searches for persistent GWs using data from the LIGO S5 science run: one optimized for pointlike sources and one for arbitrary extended sources. Finding no evidence to support the detection of GWs, we present 90% confidence level (C.L.) upper-limit maps of GW strain power with typical values between 2-20×10(-50)  strain(2) Hz(-1) and 5-35×10(-49)  strain(2) Hz(-1) sr(-1) for pointlike and extended sources, respectively. The latter result is the first of its kind. We also set 90% C.L. limits on the narrow-band root-mean-square GW strain from interesting targets including Sco X-1, SN 1987A and the Galactic center as low as ≈7×10(-25) in the most sensitive frequency range near 160 Hz.

BCL2 mutations in diffuse large B-cell lymphoma

BCL2 is deregulated in diffuse large B-cell lymphoma (DLBCL) by the t(14;18) translocation, gene amplification and/or nuclear factor-κB signaling. RNA-seq data have recently shown that BCL2 is the most highly mutated gene in germinal center B-cell (GCB) DLBCL. We have sequenced BCL2 in 298 primary DLBCL biopsies, 131 additional non-Hodgkin lymphoma biopsies, 24 DLBCL cell lines and 51 germline DNAs. We found frequent BCL2 mutations in follicular lymphoma (FL) and GCB DLBCL, but low levels of BCL2 mutations in activated B-cell DLBCL, mantle cell lymphoma, small lymphocytic leukemia and peripheral T-cell lymphoma. We found no BCL2 mutations in GC centroblasts. Many mutations were non-synonymous; they were preferentially located in the flexible loop domain, with few in BCL2-homology domains. An elevated transition/transversions ratio supports that the mutations result from somatic hypermutation. BCL2 translocations correlate with, and are likely important in acquisition of, additional BCL2 mutations in GCB DLBCL and FL. DLBCL mutations were not independently associated with survival. Although previous studies of BCL2 mutations in FL have reported mutations to result in pseudo-negative BCL2 protein expression, we find this rare in de-novo DLBCL.

SNP analysis of minimally evolved t(14;18)(q32;q21)-positive follicular lymphomas reveals a common copy-neutral loss of heterozygosity pattern

Follicular lymphoma (FL) cases with a t(14;18)(q32;q21) and minimal or no additional karyotypic alterations, such as copy number gains and losses and/or chromosomal rearrangements, may exhibit pathologic features and a clinical behavior similar to those with more complex karyotypes. This study sought to investigate whether the copy-neutral loss of heterozygosity (cnLOH) profiles of these minimally evolved t(14;18)(q32;q21)-positive follicular lymphoma (MEV-FL) cases are similar to or different from the majority of FL cases with more karyotypic alterations. Affymetrix SNP 6.0 array analysis was applied to the tumor genomes of 23 MEV-FL biopsy samples to assess for the presence of cnLOH. These cases carried either a single or no chromosomal abnormality in addition to t(14;18)(q32;q21) as determined by karyotyping. We found that, although these MEV-FL cases had simple karyotypes, they showed very similar cnLOH profiles as compared to cytogenetically complex cases. The most frequent regions affected by cnLOH were 1p (17%), 6p (17%), 12q (13%) and 16p (13%). Our study suggests that cnLOH alterations may serve as important contributors to the pathological and clinical manifestations of FL.

Abstract LB-158: MEDI4736: Delivering effective blockade of immunosupression to enhance tumour rejection: Monoclonal antibody discovery and preclinical development

Cancerous cells emerge within the body following accumulation of deleterious genetic mutations. These mutations alter the phenotype of a cancer cell marking it as distinct from the surrounding host; an immunological state termed “altered self”. These cells, like other non-self entities such as viruses and bacteria, are recognised by the immune system and marked for destruction, a process known as “immune surveillance”. B7-H1 expression by tumour cells is believed to aid tumours in evading detection and elimination by the immune system. B7-H1 functions in this respect via several alternative mechanisms including driving exhaustion and anergy of tumour infiltrating T lymphocytes, stimulating secretion of immune repressive cytokines into the tumour micro-environment, stimulating repressive regulatory T cell function and protecting B7-H1 expressing tumour cells from lysis by tumour cell specific cytotoxic T cells.

Using hybridoma technology and high throughput screening MedImmune has identified a series of fully human antibodies specific for human B7-H1. Further characterisation of these antibodies led to the identification of a single high affinity antibody, MEDI 4736, with the ability to relieve B7-H1 mediated suppression of T cell activation in vitro and to enhance sub-optimal T cell activation in a mixed lymphocyte reaction. In vitro testing shows that MEDI 4736 does not trigger non-specific cytokine release in whole blood, and is only able to activate T cells in the context of an active T cell receptor signal.

A surrogate anti-mouse B7-H1 antibody shows significant anti-tumour activity in a syngeneic model when dosed in combination with chemotherapy. Similarly MEDI 4736 is able to inhibit tumour growth in a novel in vivo xenograft model, via a mechanism that is dependent on the presence of tumour specific human T cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-158. doi:10.1158/1538-7445.AM2011-LB-158