CT-derived measures of muscle quantity and quality predict poorer outcomes from elective colorectal surgery: a UK multicentre retrospective cohort study.

PURPOSE: To assess whether preoperative radiologically defined lean muscle measures are associated with adverse clinical outcomes in patients undergoing elective surgery for colorectal cancer. METHODS: This retrospective UK-based multicentre data collection study identified patients having had colorectal cancer resection with curative intent between January 2013 to December 2016. Preoperative computed-tomography (CT) scans were used to measure psoas muscle characteristics. Clinical records provided postoperative morbidity and mortality data. RESULTS: This study included 1122 patients. The cohort was separated into a combined group (patients with both sarcopenia and myosteatosis) and others group (either sarcopenia or myosteatosis, or neither). For the combined group, anastomotic leak was predicted on univariate (OR 4.1, 95% CI 1.43-11.79; p = 0.009) and multivariate analysis (OR 4.37, 95% CI 1.41-13.53; p = 0.01). Also for the combined group, mortality (up to 5 years postoperatively) was predicted on univariate (HR 2.41, 95% CI 1.64-3.52; p < 0.001) and multivariate analysis (HR 1.93, 95% CI 1.28-2.89; p = 0.002). A strong correlation exists between freehand-drawn region of interest-derived psoas density measurement and using the ellipse tool (R2 = 81%; p < 0.001). CONCLUSION: Measures of lean muscle quality and quantity, which predict important clinical outcomes, can be quickly and easily taken from routine preoperative imaging in patients being considered for colorectal cancer surgery. As poor muscle mass and quality are again shown to predict poorer clinical outcomes, these should be proactively targeted within prehabilitation, perioperative and rehabilitation phases to minimise negative impact of these pathological states.

Visible-Light-Mediated Carbonyl Alkylative Amination to All-Alkyl α-Tertiary Amino Acid Derivatives.

The all-alkyl α-tertiary amino acid scaffold represents an important structural feature in many biologically and pharmaceutically relevant molecules. Syntheses of this class of molecule, however, often involve multiple steps and require activating auxiliary groups on the nitrogen atom or tailored building blocks. Here, we report a straightforward, single-step, and modular methodology for the synthesis of all-alkyl α-tertiary amino esters. This new strategy uses visible light and a silane reductant to bring about a carbonyl alkylative amination reaction that combines a wide range of primary amines, α-ketoesters, and alkyl iodides to form functionally diverse all-alkyl α-tertiary amino esters. Brønsted acid-mediated in situ condensation of primary amine and α-ketoester delivers the corresponding ketiminium species, which undergoes rapid 1,2-addition of an alkyl radical (generated from an alkyl iodide by the action of visible light and silane reductant) to form an aminium radical cation. Upon a polarity-matched and irreversible hydrogen atom transfer from electron rich silane, the electrophilic aminium radical cation is converted to an all-alkyl α-tertiary amino ester product. The benign nature of this process allows for broad scope in all three components and generates structurally and functionally diverse suite of α-tertiary amino esters that will likely have widespread use in academic and industrial settings.

Modular Photocatalytic Synthesis of α-Trialkyl-α-Tertiary Amines.

Molecules displaying an α-trialkyl-α-tertiary amine motif provide access to an important and versatile area of biologically relevant chemical space but are challenging to access through existing synthetic methods. Here, we report an operationally straightforward, multicomponent protocol for the synthesis of a range of functionally and structurally diverse α-trialkyl-α-tertiary amines, which makes use of three readily available components: dialkyl ketones, benzylamines, and alkenes. The strategy relies on the of use visible-light-mediated photocatalysis with readily available Ir(III) complexes to bring about single-electron reduction of an all-alkyl ketimine species to an α-amino radical intermediate; the α-amino radical undergoes Giese-type addition with a variety of alkenes to forge the α-trialkyl-α-tertiary amine center. The mechanism of this process is believed to proceed through an overall redox neutral pathway that involves photocatalytic redox-relay of the imine, generated from the starting amine-ketone condensation, through to an imine-derived product. This is possible because the presence of a benzylic amine component in the intermediate scaffold drives a 1,5-hydrogen atom transfer step after the Giese addition to form a stable benzylic α-amino radical, which is able to close the photocatalytic cycle. These studies detail the evolution of the reaction platform, an extensive investigation of the substrate scope, and preliminary investigation of some of the mechanistic features of this distinct photocatalytic process. We believe this transformation will provide convenient access to previously unexplored α-trialkyl-α-tertiary amine scaffolds that should be of considerable interest to practitioners of synthetic and medicinal chemistry in academic and industrial institutions.

The efficacy of 'static' training interventions for improving indices of cardiorespiratory fitness in premenopausal females.

PURPOSE: Cardiovascular disease (CVD) is the leading cause of death worldwide. Many risk factors for CVD can be modified pharmacologically; however, uptake of medications is low, especially in asymptomatic people. Exercise is also effective at reducing CVD risk, but adoption is poor with time-commitment and cost cited as key reasons for this. Repeated remote ischaemic preconditioning (RIPC) and isometric handgrip (IHG) training are both inexpensive, time-efficient interventions which have shown some promise in reducing blood pressure (BP) and improving markers of cardiovascular health and fitness. However, few studies have investigated the effectiveness of these interventions in premenopausal women. METHOD: Thirty healthy females were recruited to twelve supervised sessions of either RIPC or IHG over 4 weeks, or acted as non-intervention controls (CON). BP measurements, flow-mediated dilatation (FMD) and cardiopulmonary exercise tests (CPET) were performed at baseline and after the intervention period. RESULTS: IHG and RIPC were both well-tolerated with 100% adherence to all sessions. A statistically significant reduction in both systolic (- 7.2 mmHg) and diastolic (- 6 mmHg) BP was demonstrated following IHG, with no change following RIPC. No statistically significant improvements were observed in FMD or CPET parameters in any group. CONCLUSIONS: IHG is an inexpensive and well-tolerated intervention which may improve BP; a key risk factor for CVD. Conversely, our single arm RIPC protocol, despite being similarly well-tolerated, did not elicit improvements in any cardiorespiratory parameters in our chosen population.

Long-term outcomes of biological mesh repair following extra levator abdominoperineal excision of the rectum: an observational study of 100 patients.

BACKGROUND: Current evidence suggests that pelvic floor reconstruction following extralevator abdominoperineal excision of rectum (ELAPER) may reduce the risk of perineal herniation of intra-abdominal contents. Options for reconstruction include mesh and myocutaneous flaps, for which long-term follow-up data is lacking. The aim of this study was to evaluate the long-term outcomes of biological mesh (Surgisis®, Biodesign™) reconstruction following ELAPER. METHODS: A retrospective review of all patients having ELAPER in a single institution between 2008 and 2018 was perfomed. Clinic letters were scrutinised for wound complications and all available cross sectional imaging was reviewed to identify evidence of perineal herniation (defined as presence of intra-abdominal content below a line between the coccyx and the lower margin of the pubic symphysis on sagittal view). RESULTS: One hundred patients were identified (median age 66, IQR 59-72 years, 70% male). Median length of follow-up was 4.9 years (IQR 2.3-6.7 years). One, 2- and 5-year mortality rates were 3, 8 and 12%, respectively. Thirty three perineal wounds had not healed by 1 month, but no mesh was infected and no mesh needed to be removed. Only one patient developed a symptomatic perineal hernia requiring repair. On review of imaging a further 7 asymptomatic perineal hernias were detected. At 4 years the cumulative radiologically detected perineal hernia rate was 8%. CONCLUSIONS: This study demonstrates that pelvic floor reconstruction using biological mesh following ELAPER is both safe and effective as a long-term solution, with low major complication rates. Symptomatic perineal herniation is rare following mesh reconstruction, but may develop sub clinically and be detectable on cross-sectional imaging.

Carboxylate-Assisted Oxidative Addition to Aminoalkyl PdII Complexes: C(sp3 )-H Arylation of Alkylamines by Distinct PdII /PdIV Pathway.

Reported is the discovery of an approach to functionalize secondary alkylamines using 2-halobenzoic acids as aryl-transfer reagents. These reagents promote an unusually mild carboxylate-assisted oxidative addition to alkylamine-derived palladacycles. In the presence of AgI salts, a decarboxylative C(sp3 )-C(sp2 ) bond reductive elimination leads to γ-aryl secondary alkylamines and renders the carboxylate motif a traceless directing group. Stoichiometric mechanistic studies were effectively translated to a Pd-catalyzed γ-C(sp3 )-H arylation process for secondary alkylamines.

Fibrin glue is a quick and effective treatment for primary and recurrent pilonidal sinus disease.

BACKGROUND: Pilonidal sinus disease (PSD) is a common, chronic inflammatory condition involving hair follicles within the natal cleft. It mainly affects young males and creates a significant health, social and economic burden. Traditional surgery is often radical resulting in pain, wound complications, long recovery times and poor cosmesis. The aim of our study was to evaluate fibrin glue as a primary treatment for PSD. METHODS: Fibrin glue procedures for a single surgeon at our institution were identified from operative coding databases and the logbook from January 2011 to January 2016. Patients had curettage of the sinus with fibrin glue obliteration. Recurrence data was collected retrospectively. RESULTS: One hundred and forty-six patients were identified; (115 (79%) males, mean age 30 (range 16-78 years). One hundred and forty-four (99%) were discharged the same day. Four (2.7%) were treated conservatively for wound discharge. Median operating time was 9 (range 4-28) min. There were 40 (27%) recurrences after one glue application. Median time to recurrence was 4 (range 0.25-36) months. Twenty-four (60%) of the recurrences had repeat glue treatment with 4 (16.6%) recurrences. After 2 rounds of treatment with glue alone, 126 out of 130 (96.9%) patients had healed. CONCLUSIONS: Fibrin glue application following curettage of the sinus is a quick and effective procedure for first and second line treatment of PSD.

Expression profiling of Sudanese visceral leishmaniasis patients pre- and post-treatment with sodium stibogluconate.

Visceral leishmaniasis (VL) in Sudan caused by Leishmania donovani is fatal in susceptible individuals if untreated. Treatment with sodium stibogluconate (SSG) leads to post-kala-azar dermal leishmaniasis (PKDL) in 58% of patients. Here, Affymetrix microarrays were used to identify genes differentially expressed in lymph nodes (N=9 paired samples) pre- and post-treatment with SSG. Using the Bioconductor package limma, 438 genes from 28 869 post-quality-control probe sets were differentially expressed (Pnominal ≤.02) post- vs pretreatment. Canonical pathway analysis using Ingenuity Pathway Analysis™ identified "role of nuclear factor of activated T-cell in regulation of immune response" (Pnominal =1.35×10-5 ; PBH-adjusted =4.79×10-3 ), "B-cell development" (Pnominal =2.04×10-4 ; PBH-adjusted =.024), "Fcγ receptor-mediated phagocytosis in macrophages and monocytes" (Pnominal =2.04×10-4 ; PBH-adjusted =.024) and "OX40 signalling" (Pnominal =2.82×10-4 ; PBH-adjusted =.025) as pathways differentially regulated post- vs pretreatment. Major network hub genes included TP53, FN1, MYC, BCL2, JUN, SYK, RUNX2, MMP1 and ACTA2. Top endogenous upstream regulators included IL-7 (P=2.28×10-6 ), TNF (P=4.26×10-6 ), Amyloid Precursor Protein (P=4.23×10-5 ) and SPI1/PI.1 (P=1.17×10-7 ). Top predicted chemical drug regulators included the flavonoid genistein (P=4.56×10-7 ) and the quinoline alkaloid camptothecin (P=5.14×10-5 ). These results contribute to our understanding of immunopathology associated with VL and response to SSG treatment. Further replication could identify novel therapeutic strategies that improve on SSG treatment and reduce the likelihood of progression to PKDL.

Anaesthetists stress is induced by patient ASA grade and may impair non-technical skills during intubation.

BACKGROUND: The aims of this study were to determine if patient ASA grade was associated with increased stress in anaesthetists with a subsequent effect on non-technical skills. METHODS: Stress was measured using a validated objective (heart rate variability or heart rate) and subjective tool. We studied eight consultant anaesthetists at baseline (rest) and during 16 episodes of intubation with an ASA 1 or 2 patient vs. an ASA 3 or 4 patient. The primary outcome for the study was objective and subjective stress between both patient groups. Secondary outcomes were non-technical skill ratings and the association between stress measurements. RESULTS: ASA 3 or 4 patients were associated with increases in objective stress when compared to baseline (mean 4.6 vs. 6.7; P = 0.004). However, ASA 1 or 2 patients were not associated with increases in stress when compared to baseline (mean 4.6 vs. 4.7; P = 1). There was no significant difference in subjective stress between the groups (P = 0.18). Objective stress negatively affected situational awareness (P = 0.03) and decision-making (P = 0.03); however, these did not decline to a clinically significant threshold. Heart rate variability (r = 0.60; P = 0.002) better correlated with subjective stress when compared to heart rate (r = 0.30; P = 0.15). Agreement between raters for Anaesthetic Non-Technical Skills (ANTS) scores was acceptable (ICC = 0.51; P = 0.003). CONCLUSION: This study suggests that higher patient ASA grade can increase stress in anaesthetists, which may impair non-technical skills.

Genome-wide association study of IgG1 responses to the choline-binding protein PspC of Streptococcus pneumoniae.

Streptococcus pneumoniae causes invasive pneumococcal disease. Delayed development of antibodies to S. pneumoniae in infancy is associated with the development of atopy and asthma. Pneumococcal surface protein C (PspC) is a vaccine candidate and variation in its choline-binding region is associated with invasive disease. This study examined 523 060 single-nucleotide polymorphisms in The Western Australian Pregnancy Cohort (Raine) Study to find loci influencing immunoglobulin G1 (IgG1) responses to PspC measured at age 14 years (n=1152). Genome-wide significance (top SNP rs9275596; P=3.1 × 10(-14)) was only observed at human leucocyte antigen (HLA). Imputed HLA amino-acid polymorphisms showed the strongest associations at positions DRB1 47 (P=3.2 × 10(-11)), 13SRG (P=9.8 × 10(-10)) and 11SP (P=9.8 × 10(-10)), and at DQA1 34 (P=6.4 × 10(-10)), DQB1 167R (P=9.3 × 10(-6)) and HLA-B 95 W (P=1.2 × 10(-9)). Conditional analyses showed independent contributions from DRB1 47 and DQB1 167R to the signal at rs9275596, supported by an omnibus test showing a strong signal for the haplotype DRB1_47_DQB1_167 (P=9.02 × 10(-15)). In silico analysis showed that DRB1 four-digit allele groups defined by DRB1 47F bind to a greater complexity of core 9-mer epitopes compared with DRB1 47Y, especially across repeats in the C-term choline-binding region. Consequent differences in CD4 T-cell help for IgG1 to PspC could have implications for vaccine design. Further analysis in other cohorts is merited.

Variation in the risk of venous thromboembolism following colectomy.

BACKGROUND: Guidelines recommend extended thromboprophylaxis following colectomy for malignant disease, but not for non-malignant disease. The aim of this study was to determine absolute and relative rates of venous thromboembolism (VTE) following colectomy by indication, admission type and time after surgery. METHODS: A cohort study of patients undergoing colectomy in England was undertaken using linked primary (Clinical Practice Research Datalink) and secondary (Hospital Episode Statistics) care data (2001-2011). Crude rates and adjusted hazard ratios (HRs) were calculated for the risk of first VTE following colectomy using Cox regression analysis. RESULTS: Some 12,388 patients were identified; 312 (2·5 per cent) developed VTE after surgery, giving a rate of 29·59 (95 per cent c.i. 26·48 to 33·06) per 1000 person-years in the first year after surgery. Overall rates were 2·2-fold higher (adjusted HR 2·23, 95 per cent c.i. 1·76 to 2·50) for emergency compared with elective admissions (39·44 versus 25·78 per 1000 person-years respectively). Rates of VTE were 2·8-fold higher in patients with malignant disease versus those with non-malignant disease (adjusted HR 2·84, 2·04 to 3·94). The rate of VTE was highest in the first month after emergency surgery, and declined from 121·68 per 1000 person-years in the first month to 25·65 per 1000 person-years during the rest of the follow-up interval. Crude rates of VTE were similar for malignant and non-malignant disease (114·76 versus 120·98 per 1000 person-years respectively) during the first month after emergency surgery. CONCLUSION: Patients undergoing emergency colectomy for non-malignant disease have a similar risk of VTE as patients with malignant disease in the first month after surgery.

Study investigating the role of skeletal muscle mass estimation in metastatic spinal cord compression.

BACKGROUND: Age-related loss of functional muscle mass is associated with reduced functional ability and life expectancy. In disseminated cancer, age-related muscle loss may be exacerbated by cachexia and poor nutritional intake, increasing functional decline, morbidity and accelerate death. Patients with spinal metastases frequently present for decompressive surgery with decision to operate based upon functional assessment. A subjective assessment of physical performance has, however, been shown to be a poor indicator of life expectancy in these patients. We aimed to develop an objective measure based upon lean muscle mass to aid decision making, in these individuals, by investigating the association between muscle mass and 1-year survival. METHODS: Muscle mass was calculated as total psoas area (TPA)/ vertebral body area (VBA), by two independent blinded doctors from CT images, acquired within 7 days of spinal metastases surgery, at the mid L3 vertebral level. Outcome at 1 year following surgery was recorded from a prospectively updated metastatic spinal cord compression database. RESULTS: 86 patients were followed for 1 year, with an overall mortality of 39.5%. Mortality rates at 1 year were significantly high among patients in the lowest quartile of muscle mass, compared with those in the highest quartile (57.1 vs 23.8%, p=0.02). CONCLUSION: Death within 1 year in individuals with spinal metastases is related to lean muscle mass at presentation. Assessment of lean muscle mass may inform decision to operate in patients with spinal metastases.

Genome-wide association study of vitamin D levels in children: replication in the Western Australian Pregnancy Cohort (Raine) study.

This genome-wide association study (GWAS) utilises data from the Western Australian Pregnancy Cohort (Raine) Study for 25-hydroxyvitamin D (25(OH)D) levels measured in blood collected at age 6 years (n=673) and at age 14 years (n=1140). Replication of significantly associated genes from previous GWASs was found for both ages. Genome-wide significant associations were found both at age 6 and 14 with single nucleotide polymorphisms (SNPs) on chromosome 11p15 in PDE3B/CYP2R1 (age 6: rs1007392, P=3.9 × 10(-8); age14: rs11023332, P=2.2 × 10(-10)) and on chromosome 4q13 in GC (age 6: rs17467825, P=4.2 × 10(-9); age14: rs1155563; P=3.9 × 10(-9)). In addition, a novel association was observed at age 6 with SNPs on chromosome 7p15 near NPY (age 6: rs156299, P=1.3 × 10(-6)) that could be of functional interest in highlighting alternative pathways for vitamin D metabolism in this age group and merits further analysis in other cohort studies.

Street football is a feasible health-enhancing activity for homeless men: biochemical bone marker profile and balance improved.

This case-control study investigated the feasibility of street football as a health-enhancing activity for homeless men, specifically the musculoskeletal effects of 12 weeks of training. Twenty-two homeless men participated in the football group (FG) and 10 served as controls (C). Plasma osteocalcin, TRACP5b, leptin, and postural balance were measured, and whole-body DXA scanning was performed. The attendance rate was 75% (2.2 ± 0.7 sessions per week). During 60 min of training, the total distance covered was 5534 ± 610 m, with 1040 ± 353, 2744 ± 671, and 864 ± 224 m covered by high-intensity, low-intensity, and backwards/sideways running, respectively. In FG, osteocalcin increased by 27% from 20.1 ± 11.1 to 25.6 ± 11.8 ng/mL (P = 0.007). Postural balance increased by 39% (P = 0.004) and 46% (P = 0.006) in right and left leg. Trunk bone mineral density increased by 1.0% from 0.959 ± 0.095 to 0.969 ± 0.090 g/cm(2) (P = 0.02). No effects were observed in C. In conclusion, street football appears to be a feasible training activity with musculoskeletal health benefits for homeless men. The attendance rate and the training intensity were high, and 12 weeks of training resulted in a substantial anabolic response in bone metabolism. Postural balance improved markedly, and the overall risk of falling, and hospitalization due to sudden trauma, could be reduced by street football for homeless men.

Covalent hits and where to find them.

Covalent hits for drug discovery campaigns are neither fantastic beasts nor mythical creatures, they can be routinely identified through electrophile-first screening campaigns using a suite of different techniques. These include biophysical and biochemical methods, cellular approaches, and DNA-encoded libraries. Employing best practice, however, is critical to success. The purpose of this review is to look at state of the art covalent hit identification, how to identify hits from a covalent library and how to select compounds for medicinal chemistry programmes.

Design of a Lead-Like Cysteine-Targeting Covalent Library and the Identification of Hits to Cys55 of Bfl-1.

Covalent hit identification is a viable approach to identify chemical starting points against difficult-to-drug targets. While most researchers screen libraries of <2k electrophilic fragments, focusing on lead-like compounds can be advantageous in terms of finding hits with improved affinity and with a better chance of identifying cryptic pockets. However, due to the increased molecular complexity, larger numbers of compounds (>10k) are desirable to ensure adequate coverage of chemical space. Herein, the approach taken to build a library of 12k covalent lead-like compounds is reported, utilizing legacy compounds, robust library chemistry, and acquisitions. The lead-like covalent library was screened against the antiapoptotic protein Bfl-1, and six promising hits that displaced the BIM peptide from the PPI interface were identified. Intriguingly, X-ray crystallography of lead-like compound 8 showed that it binds to a previously unobserved conformation of the Bfl-1 protein and is an ideal starting point for the optimization of Bfl-1 inhibitors.

Identification and Evaluation of Reversible Covalent Binders to Cys55 of Bfl-1 from a DNA-Encoded Chemical Library Screen.

Bfl-1 is overexpressed in both hematological and solid tumors; therefore, inhibitors of Bfl-1 are highly desirable. A DNA-encoded chemical library (DEL) screen against Bfl-1 identified the first known reversible covalent small-molecule ligand for Bfl-1. The binding was validated through biophysical and biochemical techniques, which confirmed the reversible covalent mechanism of action and pointed to binding through Cys55. This represented the first identification of a cyano-acrylamide reversible covalent compound from a DEL screen and highlights further opportunities for covalent drug discovery through DEL screening. A 10-fold improvement in potency was achieved through a systematic SAR exploration of the hit. The more potent analogue compound 13 was successfully cocrystallized in Bfl-1, revealing the binding mode and providing further evidence of a covalent interaction with Cys55.

Canceling the elastic Poynting effect with geometry.

The Poynting effect is a paragon of nonlinear soft matter mechanics. It is the tendency (found in all incompressible, isotropic, hyperelastic solids) exhibited by a soft block to expand vertically when sheared horizontally. It can be observed whenever the length of the cuboid is at least four times its thickness. Here we show that the Poynting effect can be easily reversed and the cuboid can shrink vertically, simply by reducing this aspect ratio. In principle, this discovery means that for a given solid, say one used as a seismic wave absorber under a building, an optimal ratio exists where vertical displacements and vibrations can be completely eliminated. Here we first recall the classical theoretical treatment of the positive Poynting effect, and then show experimentally how it can be reversed. Using finite-element simulations, we then investigate how the effect can be suppressed. We find that cubes always provide a reverse Poynting effect, irrespective of their material properties (in the third-order theory of weakly nonlinear elasticity).

FLI1 polymorphism affects susceptibility to cutaneous leishmaniasis in Brazil.

Mapping murine genes controlling cutaneous leishmaniasis (CL) identified Fli1 as a candidate influencing resistance to L. major and enhanced wound healing. We examine FLI1 as a gene controlling CL and mucosal leishmaniasis (ML) caused by L. braziliensis in humans. Intron 1 single nucleotide polymorphisms tagging promoter and enhancer elements were analysed in 168 nuclear families (250 CL; 87 ML cases) and replicated in 157 families (402 CL; 39 ML cases). Robust case-pseudocontrol logistic regression analysis showed association between allele C (odds ratio (OR) 1.65; 95% confidence interval 1.18-2.29; P=0.003) of FLI1_rs7930515 and CL in the primary sample that was confirmed (OR 1.60; 95% confidence interval 1.10-2.33; P=0.014) in the replication set (combined P=1.8 × 10(-4)). FLI1_rs7930515 is in linkage disequilibrium with the functional GAn microsatellite in the proximal promoter. Haplotype associations extended across the enhancer, which was not polymorphic. ML associated with inverse haplotypes compared with CL. Wound healing is therefore important in CL, providing potential for therapies modulating FLI1.

FBXO11, a regulator of the TGFß pathway, is associated with severe otitis media in Western Australian children.

Otitis media (OM) is a common childhood disease characterised by middle ear inflammation following infection. Susceptibility to recurrent acute OM (rAOM) and chronic OM with effusion (COME) is highly heritable. Two murine mutants, Junbo and Jeff, spontaneously develop severe OM with similar phenotypes to human disease. Fine-mapping of these mutants identified two genes (Evi1 and Fbxo11) that interact with the transforming growth factor ß (TGFß) signalling pathway. We investigated these genes, as well as four Sma- and Mad-related (SMAD) genes of the TGFß pathway, as candidate rAOM/COME susceptibility genes in two predominantly Caucasian populations. Single-nucleotide polymorphisms (SNPs) within FBXO11 (family-based association testing Z-Score=2.61; P(best)=0.009) were associated with severe OM in family-based analysis of 434 families (561 affected individuals) from the Western Australian Family Study of OM. The FBXO11 association was replicated by directed analysis of Illumina 660W-Quad Beadchip data available for 253 cases and 866 controls (OR=1.55 (95% CI 1.28-1.89); P(best)=6.9 × 10(-6)) available within the Western Australian Pregnancy Cohort (Raine) Study. Combined primary and replication results show P(combined)=2.98 × 10(-6). Neither cohort showed an association with EVI1 variants. Family-based associations at SMAD2 (P=0.038) and SMAD4 (P=0.048) were not replicated. Together, these data provide strong evidence for FBXO11 as a susceptibility gene for severe OM.