Severity in a Norwegian hospitalized injury material (N = 177,663) by two severity measures: threat-to-life and threat of disability

We conducted a registry-based cohort study of all individuals aged 25-64 years residing in Norway by 1st of January 2008 (N = 2,535,213). This cohort was followed from 2008 through 2014 using inpatient registrations for acute hospitalizations due to all-cause injuries, getting 177,663 cases of hospitalized persons (incidence rate of new cases: 102.1 pr 10,000 person-years at risk). We derived two measures of severity: threat-to-life using the International Classification of Disease-based Injury Severity Score (ICISS) (Stephenson et al 2004; Gedeborg et al 2014), and threat of disability using long-term disability weights (DW) from the Injury-VIBES project (Gabbe et al 2014), also based on the ICD-codes. We found the following distributions of the hospitalized persons (N = 177,663): 1) Threat to life (ICISS): High threat to life: 4,186 (2.4 %); Lower threat to life: 173,477 (97.6%). 2) Threat of disability (Injury Vibes DW): High probability of long-term disability (DW-score < 0.807): 36,573 (20,6 %); Medium probability of long-term disability (DW-score 0.807-0.947): 97,590 (54,9 %); low probability of long-term disability (DW-score >0.947): 43,530 (24.5 %). Correlation between ICISS-score and the Injury Vibes disability weight score was moderate (r = 0.418, p < 0.001). The presentation will end up in a discussion on which of these two severity measures could be used for comparing burden of injuries across countries.

References

Gabbe BJ, Simpson PM, Lyons RA, et al. (2014) Association between the Number of Injuries Sustained and 12-Months Disability Outcomes: Evidence from the Injury-VIBES Study. PLos ONE, 9(12):e113467. DOI: 10.1371/journal.pone.0113467.

Gedeborg R, Warner M, Chen LH, et al. (2014) Internationally comparable diagnosis-specific survival probabilites for calculation of the ICD-10-based Injury Severity Score. J Trauma Acute Care Surg, 76(2):358-65. DOI: 10.1097/ta.0b013e3182a9cd31.

Incisional hernia following colorectal cancer surgery according to suture technique: Hughes Abdominal Repair Randomized Trial (HART)

BACKGROUND

Incisional hernias cause morbidity and may require further surgery. HART (Hughes Abdominal Repair Trial) assessed the effect of an alternative suture method on the incidence of incisional hernia following colorectal cancer surgery.

METHODS

A pragmatic multicentre single-blind RCT allocated patients undergoing midline incision for colorectal cancer to either Hughes closure (double far-near-near-far sutures of 1 nylon suture at 2-cm intervals along the fascia combined with conventional mass closure) or the surgeon's standard closure. The primary outcome was the incidence of incisional hernia at 1 year assessed by clinical examination. An intention-to-treat analysis was performed.

RESULTS

Between August 2014 and February 2018, 802 patients were randomized to either Hughes closure (401) or the standard mass closure group (401). At 1 year after surgery, 672 patients (83.7 per cent) were included in the primary outcome analysis; 50 of 339 patients (14.8 per cent) in the Hughes group and 57 of 333 (17.1 per cent) in the standard closure group had incisional hernia (OR 0.84, 95 per cent c.i. 0.55 to 1.27; P = 0.402). At 2 years, 78 patients (28.7 per cent) in the Hughes repair group and 84 (31.8 per cent) in the standard closure group had incisional hernia (OR 0.86, 0.59 to 1.25; P = 0.429). Adverse events were similar in the two groups, apart from the rate of surgical-site infection, which was higher in the Hughes group (13.2 versus 7.7 per cent; OR 1.82, 1.14 to 2.91; P = 0.011).

CONCLUSION

The incidence of incisional hernia after colorectal cancer surgery is high. There was no statistical difference in incidence between Hughes closure and mass closure at 1 or 2 years.

REGISTRATION NUMBER

ISRCTN25616490 (http://www.controlled-trials.com).

O101 Increased contractile activity through electrical stimulation attenuates postoperative loss of muscle mass and function, even in the presence of inadequate nutrition

Introduction

Significant muscle atrophy occurs after major abdominal surgery. Lack of physical activity and protein intake may play a significant role. This study assesses the efficacy of neuromuscular electrical stimulation (NMES) in attenuating loss of muscle mass and function following open colorectal resection.

Methods

Fifteen patients were recruited, and their lower limbs randomised to control (CON) or NMES (STIM). Vastus Lateralis (VL) cross sectional area (CSA), muscle thickness (MT) and knee extensor strength (KES) were measured preoperatively and repeated on postoperative day (POD) 5. Dietary intake was recorded, and nutritional intake calculated. Fifteen minutes of NMES was applied to the quadriceps of the STIM leg twice a day on POD 1–4. All outcomes were analysed using linear mixed model approaches. The study was approved by the NHS REC (ref 20/EM/069).

Results

NMES significantly reduced the loss of CSA (mean difference (MD) 1.18, 95%CI: 0.75–1.61, p<0.001), MT (MD 0.12, 95%CI: 0.04–0.2, p=0.001) and KES (MD 4.48, 95%CI: 0.00–8.97, p=0.03). Total energy and protein intakes over POD1 - 4 were 42.6% (± 19.7) and 21.1% (± 11.4) of the ESPEN recommended daily amount for perioperative patients. No adverse events occurred, and patients reported that NMES caused minimal or no discomfort.

Conclusion

NMES has been demonstrated to reduce loss of muscle mass and function following major abdominal surgery and may be an important tool in aiding recovery to normal functional state.

Further studies should establish the efficacy of bilateral whole-leg NMES for improving patient centred outcomes.

Take-home message

Loss of muscle mass and function after major abdominal surgery causes significant morbidity. Neuromuscular electrical stimulation reduces this muscle loss and should be investigated further as a potential therapy.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

The new map of injuries in the aftermath of the COVID-19 pandemic: examples from north with south Europe

The aim of this paper is to describe the impact of the pandemic on injuries. Data from National Injury Surveillance System of Norway and Portugal during Covid-19 period were analyzed. In Norway hospital data on injury diagnoses were collected from a national emergency preparedness register established during the pandemic. The number of injured patients per day in the period 1 January-30 June 2020 were identified. The change in patient volumes over two three-week periods before and during the lockdown by sex, age, level of care, level of urgency, type of contact and type of injury were analysed. In Portugal we described the temporal trend in 2020 of the Home and Leisure Accidents(HLA) among vulnerable groups(0-19years, 65years+), who needed attendance in Emergency Department(ED) of the National Health Service Hospitals. In 2019 and 2020, 240 538 HLA episodes were recorded in the age groups of interest. In Norway, there was an overall reduction of 43% in injured patients during the first three weeks of lockdown. The decrease in patient contacts did not differ by sex, but was most pronounced among young people. Substantial reductions were observed for both acute and elective treatment and across all levels of care and types of contact, with the exception of indirect patient contacts. The change in patient contacts varied considerably by injury type, with the largest reduction observed for dislocations/sprains/strains and a lower decrease for burns/corrosions/poisoning. Similar trend was observed in Portugal on home and leisure accidents episodes rate registered in children and young people up to 19 years decreased by 24,0% during the 2020 year. In groups of 10-14 years the greatest significant decrease of 35,2% was observed, followed by groups of 5-9 years with a decrease of 24,1%. In 65-74 years an increase of 13,2% was recorded, with the highest increase(19,1%) among people aged 75+. Implications for the health systems and health policy planning will be discussed.

Differential regulation of the DNA methylome in adults born during the Great Chinese Famine in 1959-1961

BACKGROUND

Extensive epidemiological studies have established the association between exposure to early-life adversity and health status and diseases in adults. Epigenetic regulation is considered as a key mediator for this phenomenon but analysis on humans is sparse. The Great Chinese Famine lasting from 1958 to 1961 is a natural string of disasters offering a precious opportunity for elucidating the underlying epigenetic mechanism of the long-term effect of early adversity.

METHODS

Using a high-throughput array platform for DNA methylome profiling, we conducted a case-control epigenome-wide association study on early-life exposure to Chinese famine in 79 adults born during 1959-1961 and compared to 105 unexposed subjects born 1963-1964.

RESULTS

The single CpG site analysis of whole epigenome revealed a predominant pattern of decreased DNA methylation levels associated with fetal exposure to famine. Four CpG sites were detected with p < 1e-06 (linked to EHMT1, CNR1, UBXN7 and ESM1 genes), 16 CpGs detected with 1e-06 < p < 1e-05 and 157 CpGs with 1e-05 < p < 1e-04, with a predominant pattern of hypomethylation. Functional annotation to genes and their enriched biological pathways mainly involved neurodevelopment, neuropsychological disorders and metabolism. Multiple sites analysis detected two top-rank differentially methylated regions harboring RNF39 on chromosome 6 and PTPRN2 on chromosome 7, both showing epigenetic association with stress-related conditions.

CONCLUSION

Early-life exposure to famine could mediate DNA methylation regulations that persist into adulthood with broad impacts in the activities of genes and biological pathways. Results from this study provide new clues to the epigenetic embedding of early-life adversity and its impacts on adult health.

Differential lncRNA expression profiling of cognitive function in middle and old aged monozygotic twins using generalized association analysis

Cognitive impairment is the most prominent symptom in neurodegenerative disorders affecting quality of life and mortality. However, despite years of research, the molecular mechanism underlying the regulation of cognitive function and its impairment is poorly understood. This study aims to elucidate the role of long non-coding RNAs (lncRNAs) expression and lncRNA-mRNA interaction networks, by analyzing lncRNA expression in whole blood samples of 400 middle and old aged monozygotic twins in association with cognitive function using both linear models and a generalized correlation coefficient (GCC) to capture the diverse patterns of correlation. We detected 13 probes (p < 1e-03) displaying nonlinear and 7 probes (p < 1e-03) showing linear correlations. After combining the results, we identified 20 lncRNA probes with p < 1e-03. The top lncRNA probes were annotated to genes, along with the non-coding MALAT1, that play roles in neurodegenerative diseases. The top lncRNAs were linked to functional clusters including peptidyl-glycine modification, vascular smooth muscle cells, mitotic spindle organization and protein tyrosine phosphatase. In addition, mapping of the top significant lncRNAs to the lncRNA-mRNA interaction network detected significantly enriched biological pathways involving neuroactive ligand-receptor interaction, proteasome and chemokines. We show that GCC served as a complementary approach in detecting lncRNAs missed by the conventional linear models. A combination of GCC and linear models identified lncRNAs of diverse patterns of association enriched for GO biological and molecular functions meaningful in cognitive performance and cognitive decline. The novel lncRNA regulatory network further contributed to detect significant pathways implicated in cognition.

O46 Differences in ARCP outcome by surgical specialty: a longitudinal cohort study

Introduction

Surgical training in the UK is comprised of ten specialties: cardiothoracic, general, neurosurgery, oral and maxillofacial (OMFS), otolaryngology, paediatric, plastic, trauma and orthopaedics, urology and vascular surgery. Progression through training is assessed by the Annual Review of Competency Progression (ARCP). The aim is to examine ARCP outcomes within UK surgical specialty training and identify differences between specialties.

Method

A longitudinal cohort study using data from United Kingdom Medical Education Database (UKMED) was performed across surgical specialities. ARCP outcome was the primary outcome measure. Multi-level univariate and multiple ordinal regression analyses were performed.

Result

8,220 trainees with an ARCP outcome between 2010 and 2017 were included, comprising 31,788 ARCP outcomes. There was substantial variation in the proportion of non-standard outcomes across specialties with general surgery trainees having the highest proportion of non-standard outcomes (22.5%) and urology trainees the fewest 12.4%. After adjustment, general surgery trainees were 1.3 times more likely to receive a non-standard outcome compared to T&O trainees (OR 1.33 95% CI 1.21–1.45). Urology trainees were 36% less likely to receive a non-standard outcome compared to T&O trainees (OR 0.64 95% CI 0.54–0.75). Female trainees and older age were associated with non-standard outcomes (OR 1.11 95% CI 1.02–1.22; OR 1.04 95% CI 1.03–1.05).

Conclusion

There is wide variation in the outcomes of surgical ARCP’s across specialties. General surgery has higher rates of non-standard ARCP outcomes compared to other surgical specialities. Across all specialities, female sex and older age were associated with non-standard outcomes. Further studies are required to explore these associations.

Take-home Message

There is significant variation in ARCP outcomes between specialities. Women and older trainees receive significantly more non-standard outcomes.

Age-related changes in muscle architecture and metabolism in humans: The likely contribution of physical inactivity to age-related functional decline

In the United Kingdom (UK), it is projected that by 2035 people aged >65 years will make up 23 % of the population, with those aged >85 years accounting for 5% of the total population. Ageing is associated with progressive changes in muscle metabolism and a decline in functional capacity, leading to a loss of independence. Muscle metabolic changes associated with ageing have been linked to alterations in muscle architecture and declines in muscle mass and insulin sensitivity. However, the biological features often attributed to muscle ageing are also seen in controlled studies of physical inactivity (e.g. reduced step-count and bed-rest), and it is currently unclear how many of these ageing features are due to ageing per se or sedentarism. This is particularly relevant at a time of home confinements reducing physical activity levels during the Covid-19 pandemic. Current knowledge gaps include the relative contribution that physical inactivity plays in the development of many of the negative features associated with muscle decline in older age. Similarly, data demonstrating positive effects of government recommended physical activity guidelines on muscle health are largely non-existent. It is imperative therefore that research examining interactions between ageing, physical activity and muscle mass and metabolic health is prioritised so that it can inform on the "normal" muscle ageing process and on strategies for improving health span and well-being. This review will focus on important changes in muscle architecture and metabolism that accompany ageing and highlight the likely contribution of physical inactivity to these changes.

Genetic and environmental determinants of O6-methylguanine DNA-methyltransferase (MGMT) gene methylation: a 10-year longitudinal study of Danish twins

BACKGROUND

Epigenetic inactivation of O⁶-methylguanine DNA-methyltransferase (MGMT) is associated with increased sensitivity to alkylating chemotherapeutic agents in glioblastoma patients. The genetic background underlying MGMT gene methylation may explain individual differences in treatment response and provide a clue to a personalized treatment strategy. Making use of the longitudinal twin design, we aimed, for the first time, to estimate the genetic contributions to MGMT methylation in a Danish twin cohort.

METHODS

DNA-methylation from whole blood (18 monozygotic (MZ) and 25 dizygotic (DZ) twin pairs) repeated 10 years apart from the Longitudinal Study of Aging Danish Twins (LSADT) were used to search for genetic and environmental contributions to DNA-methylation at 170 CpG sites of across the MGMT gene. Both univariate and bivariate twin models were applied. The intraclass correlations, performed on cross-sectional data (246 MZ twin pairs) from an independent study population, the Middle-Aged Danish Twins (MADT), were used to assess the genetic influence at each CpG site of MGMT for replication.

RESULTS

Univariate twin model revealed twelve CpG sites showing significantly high heritability at intake (wave 1, h² > 0.43), and seven CpG sites with significant heritability estimates at end of follow-up (wave 2, h² > 0.5). There were six significant CpG sites, located at the gene body region, that overlapped among the two waves (h² > 0.5), of which five remained significant in the bivariate twin model, which was applied to both waves. Within MZ pair correlation in these six CpGs from MADT demarks top level of genetic influence. There were 11 CpGs constantly have substantial common environmental component over the 10 years.

CONCLUSIONS

We have identified 6 CpG sites linked to the MGMT gene with strong and persistent genetic control based on their DNA methylation levels. The genetic basis of MGMT gene methylation could help to explain individual differences in glioblastoma treatment response and most importantly, provide references for mapping the methylation Quantitative Trait Loci (meQTL) underlying the genetic regulation.

Enabling single-cell trajectory network enrichment

Single-cell sequencing (scRNA-seq) technologies allow the investigation of cellular differentiation processes with unprecedented resolution. Although powerful software packages for scRNA-seq data analysis exist, systems biology-based tools for trajectory analysis are rare and typically difficult to handle. This hampers biological exploration and prevents researchers from gaining deeper insights into the molecular control of developmental processes. Here, to address this, we have developed Scellnetor; a network-constraint time-series clustering algorithm. It allows extraction of temporal differential gene expression network patterns (modules) that explain the difference in regulation of two developmental trajectories. Using well-characterized experimental model systems, we demonstrate the capacity of Scellnetor as a hypothesis generator to identify putative mechanisms driving haematopoiesis or mechanistically interpretable subnetworks driving dysfunctional CD8 T-cell development in chronic infections. Altogether, Scellnetor allows for single-cell trajectory network enrichment, which effectively lifts scRNA-seq data analysis to a systems biology level.

Novel DNA methylation marker discovery by assumption-free genome-wide association analysis of cognitive function in twins

Privileged by rapid increase in available epigenomic data, epigenome-wide association studies (EWAS) are to make a profound contribution to understand the molecular mechanism of DNA methylation in cognitive aging. Current statistical methods used in EWAS are dominated by models based on multiple assumptions, for example, linear relationship between molecular profiles and phenotype, normal distribution for the methylation data and phenotype. In this study, we applied an assumption-free method, the generalized correlation coefficient (GCC), and compare it to linear models, namely the linear mixed model and kinship model. We use DNA methylation associated with a cognitive score in 400 and 206 twins as discovery and replication samples respectively. DNA methylation associated with cognitive function using GCC, linear mixed model, and kinship model, identified 65 CpGs (p < 1e-04) from discovery sample displaying both nonlinear and linear correlations. Replication analysis successfully replicated 9 of these top CpGs. When combining results of GCC and linear models to cover diverse patterns of relationships, we identified genes like KLHDC4, PAPSS2, and MRPS18B as well as pathways including focal adhesion, axon guidance, and some neurological signaling. Genomic region-based analysis found 15 methylated regions harboring 11 genes, with three verified in gene expression analysis, also the 11 genes were related to top functional clusters including neurohypophyseal hormone and maternal aggressive behaviors. The GCC approach detects valuable methylation sites missed by traditional linear models. A combination of methylation markers from GCC and linear models enriched biological pathways sensible in neurological function that could implicate cognitive performance and cognitive aging.

Generalized correlation coefficient for genome-wide association analysis of cognitive ability in twins

Despite a strong genetic background in cognitive function only a limited number of single nucleotide polymorphisms (SNPs) have been found in genome-wide association studies (GWASs). We hypothesize that this is partially due to mis-specified modeling concerning phenotype distribution as well as the relationship between SNP dosage and the level of the phenotype. To overcome these issues, we introduced an assumption-free method based on generalized correlation coefficient (GCC) in a GWAS of cognitive function in Danish and Chinese twins to compare its performance with traditional linear models. The GCC-based GWAS identified two significant SNPs in Danish samples (rs71419535, p = 1.47e-08; rs905838, p = 1.69e-08) and two significant SNPs in Chinese samples (rs2292999, p = 9.27e-10; rs17019635, p = 2.50e-09). In contrast, linear models failed to detect any genome-wide significant SNPs. The number of top significant genes overlapping between the two samples in the GCC-based GWAS was higher than when applying linear models. The GCC model identified significant genetic variants missed by conventional linear models, with more replicated genes and biological pathways related to cognitive function. Moreover, the GCC-based GWAS was robust in handling correlated samples like twin pairs. GCC is a useful statistical method for GWAS that complements traditional linear models for capturing genetic effects beyond the additive assumption.

Differential long noncoding RNA profiling of BMI in twins

Aim: Many efforts have been deployed to identify genetic variants associated with BMI. Alternatively, we explore epigenetic contribution to BMI variation by focusing on long noncoding RNAs (lncRNAs) which represents a key layer of epigenetic control. Materials & methods: We analyzed lncRNA expression in whole blood of 229 monozygotic twin pairs in association with BMI using generalized estimating equations. Results & conclusion: Six lncRNA probes were identified as significant (false discovery rate <0.05), with BMI showing causal effects on the expression of the significant lncRNAs. Functional annotation of differential profiles identified Gene ontology biological processes including kidney development, regulations of lipid biosynthetic process, circadian rhythm, notch signaling, etc. Whole blood lncRNAs are significantly expressed in response to BMI variation.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

THU0011 ANALYSIS OF METABOLIC STATUS IN CYBRIDS REVEALED IMPAIRED METABOLIC FLEXIBILITY IN OA PROCESS

Background:

There are several metabolic pathways involved in cell metabolism, including glycolysis, tricarboxylic acid (TCA) cycle and fatty acid (FA) oxidation. Metabolic flexibility has previously described as the ability to respond or adapt to changes in metabolic demand; assessed by the ability to switch from fat to carbohydrate oxidation. In the last years there is a growing interest to assess the influence of metabolic flexibility, as a mechanism to explain how lipids can accumulate in the tissue. During OA, it has been established a relationship between mitochondrial dysfunction and cellular damage due to impairments in mitochondrial function and metabolic flexibility. Several studies have suggested that fatty acids may play an important role in OA development and progression.

Objectives:

The aim of this work was to examine the differences in glucose and fatty acid metabolism, with special focus on metabolic flexibility, in cybrids from healthy (N) or OA donors.

Methods:

Cybrids were developed using 143B.TK-Rho-0 cell line (nuclear donor) and platelets (mitochondrial donors) from healthy (N) and OA donors. Glucose and FA metabolism were measured using D-[14C(U)]glucose and [1-14C]oleic acid respectively. Metabolic flexibility was evaluated by co-culturing with glucose and oleic acid acutely by using inhibitors against glucose and FA oxidation, 20µM UK5099 and 10µM etomoxir, respectively. Incorporation of FA into lipid droplet (LD) was evaluated by thin layer chromatography and LD were stained by LD540 and analyzed by confocal microscope and flow cytometry. Mitochondrial dynamics was measured by real-time PCR method. Percentage of mitochondrial Anion Superoxide (O2-) production was evaluated incubating cells with MitoSox® using Flow Cytometer. Appropriate statistical analyses were performed with GraphPad Prism v6.

Results:

There were no changes in basal glucose metabolism between cybrids. N cybrids had higher acid-soluble metabolites, reflecting incomplete FA β-oxidation than OA cybrids. Comparing glucose and FA metabolism showed that both types of cybrids preferred to oxidize glucose. Co-culturing with glucose and Oleic acid, increased total cellular uptake and oxidation of glucose in N compared to basal condition (Figure-1) and in this condition the OA cybrids showed an increase in mitochondrial O2-production. Inhibition of FA oxidation by etomoxir increased complete glucose oxidation of N cybrids but not in OA cybrids that had a preference to oxidize oleic acid compared to basal condition. Gene expression of mitofusin-2 (MFN2) was higher in N than OA cybrids under inhibiting conditions. Combine these data indicate that N cybrids are more metabolically flexible and have better adaptative response than OA. Cybrids presented different lipid distribution patterns. Lipid droplet (LD) formation increased in both groups incubated in presence of FA. Furthermore, N cybrids showed less LD formation than OA.

Conclusion:

The results indicated that cybrids from OA patients had reduced metabolic flexibility compared to N cybrids. These results enhance our understanding of the mitochondria metabolism in OA, suggesting a mitochondrial dysfunction and impairment of metabolic flexibility during the OA process.

Disclosure of Interests:

Andrea Dalmao-Fernandez: None declared, Jenny Lund: None declared, Tamara Hermida Gómez: None declared, Maria Eugenia Vazquez Mosquera: None declared, Ignacio Rego-Perez: None declared, Francisco J. Blanco Grant/research support from: Sanofi-Aventis, Lilly, Bristol MS, Amgen, Pfizer, Abbvie, TRB Chemedica International, Glaxo SmithKline, Archigen Biotech Limited, Novartis, Nichi-iko pharmaceutical Co, Genentech, Jannsen Research & Development, UCB Biopharma, Centrexion Theurapeutics, Celgene, Roche, Regeneron Pharmaceuticals Inc, Biohope, Corbus Pharmaceutical, Tedec Meiji Pharma, Kiniksa Pharmaceuticals, Ltd, Gilead Sciences Inc, Consultant of: Lilly, Bristol MS, Pfizer, Mercedes Fernandez-Moreno: None declared

Systematic review: the effect of right hemicolectomy for cancer on postoperative bowel function

BACKGROUND

Right-sided cancer accounts for approximately 30% of bowel cancer in women and 22% in men. Colonic resection can cause changes in bowel function which affect daily activity. The aims are to assess the impact of right hemicolectomy for cancer on bowel function and to identify useful treatment modalities for managing bowel dysfunction after right hemicolectomy.

METHOD

The review was conducted in line with PRISMA. Eligible studies evaluated the impact of right hemicolectomy on bowel function in those treated for colorectal neoplasia or assessed the effect of surgical technique or other intervention on bowel function after right hemicolectomy. Right hemicolectomy for inflammatory bowel disease or benign cases only were excluded. Articles were limited to studies on human subjects written in English published between January 2008 and December 2018.

RESULTS

The searches identified 7531 articles. Nine articles met the inclusion criteria, of which eight were cohort studies and one was a randomised trial. Loose stool, increased bowel frequency and/or nocturnal defaecation following right-sided colectomy occurs in approximately one in five patients. Some of these symptoms may improve spontaneously with time. Bile acid malabsorption and/or small bowel bacterial overgrowth may be the cause for chronic dysfunction. Some studies report that no or little difference in outcome between right-sided and rectal resections likely suggests poor function after right-sided resection.

CONCLUSION

Right hemicolectomy can result in changes to bowel function. Patients should be counselled preoperatively, and follow-up should be designed to identify and effectively treat significantly altered bowel function.

Endocannabinoids and endocannabinoid-like compounds modulate hypoxia-induced permeability in CaCo-2 cells via CB1, TRPV1, and PPARα

BACKGROUND AND PURPOSE

We have previously reported that endocannabinoids modulate permeability in Caco-2 cells under inflammatory conditions and hypothesised in the present study that endocannabinoids could also modulate permeability in ischemia/reperfusion.

EXPERIMENTAL APPROACH

Caco-2 cells were grown on cell culture inserts to confluence. Trans-epithelial electrical resistance (TEER) was used to measure permeability. To generate hypoxia (0% O2), a GasPak™ EZ anaerobe pouch system was used. Endocannabinoids were applied to the apical or basolateral membrane in the presence or absence of receptor antagonists.

KEY RESULTS

Complete hypoxia decreased TEER (increased permeability) by ~35% after 4 h (recoverable) and ~50% after 6 h (non-recoverable). When applied either pre- or post-hypoxia, apical application of N-arachidonoyl-dopamine (NADA, via TRPV1), oleamide (OA, via TRPV1) and oleoylethanolamine (OEA, via TRPV1) inhibited the increase in permeability. Apical administration of anandamide (AEA) and 2-arachidonoylglycerol (2-AG) worsened the permeability effect of hypoxia (both via CB1). Basolateral application of NADA (via TRPV1), OA (via CB1 and TRPV1), noladin ether (NE, via PPARα), and palmitoylethanolamine (PEA, via PPARα) restored permeability after 4 h hypoxia, whereas OEA increased permeability (via PPARα). After 6 h hypoxia, where permeability does not recover, only basolateral application PEA sustainably decreased permeability, and NE decreased permeability.

CONCLUSIONS AND IMPLICATIONS

A variety of endocannabinoids and endocannabinoid-like compounds modulate Caco-2 permeability in hypoxia/reoxygenation, which involves multiple targets, depending on whether the compounds are applied to the basolateral or apical membrane. CB1 antagonism and TRPV1 or PPARα agonism may represent novel therapeutic targets against several intestinal disorders associated with increased permeability.

P3726Percutaneous left atrial appendage closure and conservative antithrombotic treatment in patients with atrial fibrillation and contraindication to oral anticoagulation: a 5-year follow-up study

Background

Patients with atrial fibrillation (AF) having high thromboembolic risk and either a history of major bleeding or very high bleeding risk form a treatment challenge. Percutaneous left atrial appendage closure (LAAC) offers a feasible option for stroke prevention in these patients. However, the optimal treatment strategy for AF patients with contraindications to oral anticoagulation (OAC) remains unclear.

Purpose

To study periprocedural and late events after LAAC in AF patients with contraindications to OAC therapy.

Methods

Data were collected into a prospective registry from all consenting AF patients who underwent LAAC from February 2009 to August 2018. Follow-up data was gathered during scheduled clinical visits, annual phone calls and by reviewing electronic patient records. Only AF patients with contraindications to OAC were considered for the present analysis.

Results

LAAC using mainly Amplatzer Cardiac Plugs (98.2%) was attempted in a total of 172 patients (mean age 74 years; 60 women). The mean CHA2DS2-VASc score was 3.8±1.5 and HAS-BLED score 4.0±1.0. Contraindications to OAC were prior intracranial bleeding in 112 (65.1%), other major bleeding in 33 (19.2%) and high bleeding risk in 27 patients (15.7%). Procedure was technically successful in 166 (96.5%) patients. Clinically significant in-hospital complications were as follows: two patients (1.2%) had cardiac tamponade, which was fatal in one case, one (0.6%) had device embolization and eight (4.7%) had major access site-related bleeding events. None of the patients had in-hospital thromboembolic complications. After successful implantation, 152 patients (91.6%) were discharged on aspirin. Single antiplatelet therapy was more common than dual or triple antiplatelet therapy (74.7% vs. 18.1% vs. 1.8%, respectively), while 8 patients (4.8%) received no antiplatelet therapy. The length of initial antiplatelet therapy ranged from 0.5 to 12 months and long-term antiplatelet therapy was prescribed in 53 patients (31.9%). After a median follow-up of 33 months (interquartile range 12–49) there were 29 deaths (17.5%), 16 thromboembolic events (9.6%), consisting of 11 strokes (6.6%) and 5 transient ischemic attacks (3.0%). At the time of thromboembolic event, 10 patients (62.5%) were on antithrombotic therapy. Eighteen patients (10.8%) had at least one major bleeding event after the index hospitalization. Intracranial bleeding occurred in 7 patients (4.2%) and 6 of them (85.7%) were on antithrombotic therapy when the event occurred. Most thromboembolic events (68.8%) and intracranial bleedings (57.1%) occurred after one year of follow-up. One patient (0.6%) had an asymptomatic device embolization detected at 3-month control visit. No predictive factors for thromboembolic or major bleeding events were identified.

Conclusion

The early outcome of this challenging patient group is good after LAAC, but thromboembolic and major bleeding events are not uncommon during later follow-up.

DNA methylome profiling in identical twin pairs discordant for body mass index

OBJECTIVE

Body mass index (BMI) serves as an important measurement of obesity and adiposity, which are highly correlated with cardiometabolic diseases. Although high heritability has been estimated, the identified genetic variants by genetic association studies only explain a small proportion of BMI variation. As an active effort for further exploring the molecular basis of BMI variation, large-scale epigenome-wide association studies have been conducted but with limited number of loci reported, perhaps due to poorly controlled confounding factors, including genetic factors. Being genetically identical, monozygotic twins discordant for BMI are ideal subjects for analyzing the epigenetic association between DNA methylation and BMI, providing perfect control on their genetic makeups largely responsible for BMI variation.

SUBJECTS

We performed an epigenome-wide association study on BMI using 30 identical twin pairs (15 male and 15 female pairs) with age ranging from 39 to 72 years and degree of BMI discordance ranging from 3-7.5 kg/m². Methylation data from whole blood samples were collected using the reduced representation bisulfite sequencing technique.

RESULTS

After adjusting for blood cell composition and clinical variables, we identified 136 CpGs with p-value < 1e-4, 30 CpGs with p < 1e-05 but no CpGs reached genome-wide significance. Genomic region-based analysis found 11 differentially methylated regions harboring coding and non-coding genes some of which were validated by gene expression analysis on independent samples.

CONCLUSIONS

Our DNA methylation sequencing analysis on identical twins provides new references for the epigenetic regulation on BMI and obesity.

Impact of the calcium form of β-hydroxy-β-methylbutyrate upon human skeletal muscle protein metabolism

BACKGROUND & AIMS

β-hydroxy-β-methylbutyrate (HMB) is purported as a key nutritional supplement for the preservation of muscle mass in health, disease and as an ergogenic aid in exercise. Of the two available forms of HMB (calcium (Ca-HMB) salt or free acid (FA-HMB)) - differences in plasma bioavailability have been reported. We previously reported that ∼3 g oral FA-HMB increased muscle protein synthesis (MPS) and reduced muscle protein breakdown (MPB). The objective of the present study was to quantify muscle protein metabolism responses to oral Ca-HMB.

METHODS

Eight healthy young males received a primed constant infusion of 1,2 ¹³C₂ leucine and ²H₅ phenylalanine to assess MPS (by tracer incorporation in myofibrils) and MPB (via arterio-venous (A-V) dilution) at baseline and following provision of ∼3 g of Ca-HMB; muscle anabolic (MPS) and catabolic (MPB) signalling was assessed via immunoblotting.

RESULTS

Ca-HMB led a significant and rapid (<60 min) peak in plasma HMB concentrations (483.6 ± 14.2 μM, p < 0.0001). This rise in plasma HMB was accompanied by increases in MPS (PA: 0.046 ± 0.004%/h, CaHMB: 0.072 ± 0.004%/h, p < 0001) and suppressions in MPB (PA: 7.6 ± 1.2 μmol Phe per leg min^-1, Ca-HMB: 5.2 ± 0.8 μmol Phe per leg min^-1, p < 0.01). Increases in the phosphorylation of mTORc1 substrates i.e. p70S6K1 and RPS6 were also observed, with no changes detected in the MPB targets measured.

CONCLUSIONS

These findings support the pro-anabolic properties of HMB via mTORc1, and show that despite proposed differences in bioavailability, Ca-HMB provides a comparable stimulation to MPS and suppression of MPB, to FA-HMB, further supporting its use as a pharmaconutrient in the modulation of muscle mass.

A curious case of cololithiasis

Gallstone ileus is an uncommon cause of bowel obstruction that involves cholecystoenteric fistulation and resultant passage of gallstones into the bowel. In the vast majority of cases, the fistula forms between the gallbladder and duodenum leading to small bowel obstruction. We report a case of cholecystocolic fistulation and subsequent large-bowel obstruction in a 75-year-old woman who presented acutely after taking a bowel preparation for an outpatient colonoscopy during the course of an investigation of anaemia and nonspecific abdominal pain. Preintervention imaging revealed a giant gallstone at the rectosigmoid junction, in the presence of a cholecystocolic fistula, and subsequent large bowel obstruction. After a failed period of expectant management, laparotomy and Hartmann's procedure were performed and the patient made an uneventful recovery.

Immunohistochemical Staining of Metastatic Ductal Carcinomas of the Breast by Monoclonal Antibodies used in Imaging and Therapy: A Comparative Study

Five monoclonal antibodies (MoAbs) (L6, 170H.82, 155, BrE-3 and BR96), most of which have been previously shown to target breast cancer and not normal tissues by immunoscintigraphic imaging, were evaluated for their frequency and pattern of immunohistochemical staining in 67 to 116 metastatic lesions from patients with ductal carcinoma of the breast. Immunoperoxidase staining in 75% or more of the cells occurred in 56/116 (48%) for L6, 44189 (49%) for Br, -96, 58/102 (57%) for 155, 62/99 (84%) for 170H.82, and 65.67 (97%) for BrE-3. With the first three MoAbs, an additional 6-10% of the tumors showed staining in 50-75% of tumor cells. These results illustrate that most patients with metastatic ductal carcinoma have cancer tissue in which a high percent of cells will react to several of these selected MoAbs that target different epitopes. The high expression of the MoAb targets throughout the tumor tissue makes these antibodies potential candidates to carry immunologically directed radioimmunotherapy and is an aid in selecting patients for treatment..

DNA Methylation and All-Cause Mortality in Middle-Aged and Elderly Danish Twins

Several studies have linked DNA methylation at individual CpG sites to aging and various diseases. Recent studies have also identified single CpGs whose methylation levels are associated with all-cause mortality. In this study, we perform an epigenome-wide study of the association between CpG methylation and mortality in a population of 435 monozygotic twin pairs from three Danish twin studies. The participants were aged 55-90 at the time of blood sampling and were followed for up to 20 years. We validated our results by comparison with results from a British and a Swedish cohort, as well as results from the literature. We identified 2806 CpG sites associated with mortality (false discovery rate ( FDR ) < 0.05 ), of which 24 had an association p-value below 10 - 7 . This was confirmed by intra-pair comparison controlling for confounding effects. Eight of the 24 top sites could be validated in independent datasets or confirmed by previous studies. For all these eight sites, hypomethylation was associated with poor survival prognosis, and seven showed monozygotic correlations above 35%, indicating a potential moderate to strong heritability, but leaving room for substantial shared or unique environmental effects. We also set up a predictor for mortality using least absolute shrinkage and selection operator (LASSO) regression. The predictor showed good performance on the Danish data under cross-validation, but did not perform very well in independent samples.

Modulation of the activated protein C pathway in severe haemophilia A patients: The effects of thrombomodulin and a factor V-stabilizing fab

INTRODUCTION

The thrombomodulin (TM)/activated protein C (APC) system is a key regulator of haemostasis, limiting amplification and propagation of the formed blood clot to the injury site. Dampening APC's inhibition of factor V (FV) and factor VIII (FVIII) may be a future strategy in developing next-generation therapeutic targets for haemophilia treatment.

AIMS

To determine ex vivo the respective concentration-dependent effects of TM and a FV-stabilizing Fab on the APC regulatory pathway in severe FVIII-deficient blood and plasma.

METHODS

Ten severe haemophilia A subjects and one healthy control were enrolled. Blood was spiked with TM (0, 1, 2.5, 5, 10, 20.0 nmol/L) and FV-stabilizing Fab (0, 3, 15, 65, 300 nmol/L). The respective effects were compared to FVIII concentrations of 3- and 10% using rotational thromboelastometry clotting time (CT) and thrombin generation analysis (TGA).

RESULTS

With 1 and 2.5 nmol/L TM, 5% FVIII resulted in CT similar to the absence of TM, suggesting it completely reversed the effect of APC. Increasing TM concentrations also reduced peak thrombin generation and ETP. The addition of 300 nmol/L FV-stabilizing Fab returned CT to nearly baseline, but for most subjects was less than the effects of 3- or 10% FVIII. The FV-stabilizing Fab produced similar or greater thrombin generation compared to samples with 3- or 10% FVIII.

CONCLUSIONS

The FV-stabilizing Fab resulted in enhanced CT and TGA parameters consistent with FVIII levels of 3- and 10%. Additional studies need to further characterize how modulating the APC pathway may prove beneficial in developing new haemophilia drug targets.

Jllumina - A comprehensive Java-based API for statistical Illumina Infinium HumanMethylation450 and Infinium MethylationEPIC BeadChip data processing

Measuring differential methylation of the DNA is the nowadays most common approach to linking epigenetic modifications to diseases (called epigenome-wide association studies, EWAS). For its low cost, its efficiency and easy handling, the Illumina HumanMethylation450 BeadChip and its successor, the Infinium MethylationEPIC BeadChip, is the by far most popular techniques for conduction EWAS in large patient cohorts. Despite the popularity of this chip technology, raw data processing and statistical analysis of the array data remains far from trivial and still lacks dedicated software libraries enabling high quality and statistically sound downstream analyses. As of yet, only R-based solutions are freely available for low-level processing of the Illumina chip data. However, the lack of alternative libraries poses a hurdle for the development of new bioinformatic tools, in particular when it comes to web services or applications where run time and memory consumption matter, or EWAS data analysis is an integrative part of a bigger framework or data analysis pipeline. We have therefore developed and implemented Jllumina, an open-source Java library for raw data manipulation of Illumina Infinium HumanMethylation450 and Infinium MethylationEPIC BeadChip data, supporting the developer with Java functions covering reading and preprocessing the raw data, down to statistical assessment, permutation tests, and identification of differentially methylated loci. Jllumina is fully parallelizable and publicly available at http://dimmer.compbio.sdu.dk/download.html

Exercise training promotes cardioprotection through oxygen-sparing action in high fat-fed mice

Although exercise training has been demonstrated to have beneficial cardiovascular effects in diabetes, the effect of exercise training on hearts from obese/diabetic models is unclear. In the present study, mice were fed a high-fat diet, which led to obesity, reduced aerobic capacity, development of mild diastolic dysfunction, and impaired glucose tolerance. Following 8 wk on high-fat diet, mice were assigned to 5 weekly high-intensity interval training (HIT) sessions (10 × 4 min at 85-90% of maximum oxygen uptake) or remained sedentary for the next 10 constitutive weeks. HIT increased maximum oxygen uptake by 13%, reduced body weight by 16%, and improved systemic glucose homeostasis. Exercise training was found to normalize diastolic function, attenuate diet-induced changes in myocardial substrate utilization, and dampen cardiac reactive oxygen species content and fibrosis. These changes were accompanied by normalization of obesity-related impairment of mechanical efficiency due to a decrease in work-independent myocardial oxygen consumption. Finally, we found HIT to reduce infarct size by 47% in ex vivo hearts subjected to ischemia-reperfusion. This study therefore demonstrated for the first time that exercise training mediates cardioprotection following ischemia in diet-induced obese mice and that this was associated with oxygen-sparing effects. These findings highlight the importance of optimal myocardial energetics during ischemic stress.

Computerized cognitive remediation training for schizophrenia: an open label, multi-site, multinational methodology study

A recent single-site study (Fisher et al., 2009. Am J Psychiatry. 166 (7) 805-11) showed that repeated training with the Brain Fitness Program (BFP) improved performance on a battery of neuropsychological tasks. If replicated these data suggest an important non-pharmacological method for ameliorating cognitive impairment in schizophrenia. Our study evaluated the BFP training effects in an open-label, multi-site, multinational clinical trial. Fifty-five stable adult patients with schizophrenia on regular antipsychotic medication completed ≥ 32 BFP training sessions over 8-10 weeks. Training effects on cognitive performance and functional capacity outcome measures were measured using CogState® schizophrenia battery, UCSD Performance based Skills Assessment (UPSA-2) and Cognitive Assessment Interview (CAI). BFP training showed a large and significant treatment effect on a training exercise task (auditory processing speed), however this effect did not generalize to improved performance on independent CogState® assessment. There were no significant effects on UPSA-2 or CAI scores. Our study demonstrated the feasibility of implementing BFP training in a multi-site study. However, BFP training did not show significant treatment effects on cognitive performance or functional capacity outcome measures despite showing large and significant effects on a training exercise.

Improved and standardized method for assessing years lived with disability after injury

OBJECTIVE

To develop a standardized method for calculating years lived with disability (YLD) after injury.

METHODS

The method developed consists of obtaining data on injury cases seen in emergency departments as well as injury-related hospital admissions, using the EUROCOST system to link the injury cases to disability information and employing empirical data to describe functional outcomes in injured patients.

FINDINGS

Overall, 87 weights and proportions for 27 injury diagnoses involving lifelong consequences were included in the method. Almost all of the injuries investigated (96-100%) could be assigned to EUROCOST categories. The mean number of YLD per case of injury varied with the country studied. Use of the novel method resulted in estimated burdens of injury that were 3 to 8 times higher, in terms of YLD, than the corresponding estimates produced using the conventional methods employed in global burden of disease studies, which employ disability-adjusted life years.

CONCLUSION

The novel method for calculating YLD after injury can be applied in different settings, overcomes some limitations of the method used to calculate the global burden of disease, and allows more accurate estimates of the population burden of injury.

High intensity interval training alters substrate utilization and reduces oxygen consumption in the heart

AIMS

although exercise training induces hypertrophy with improved contractile function, the effect of exercise on myocardial substrate metabolism and cardiac efficiency is less clear. High intensity training has been shown to produce more profound effects on cardiovascular function and aerobic capacity than isocaloric low and moderate intensity training. The aim of the present study was to explore metabolic and mechanoenergetic changes in the heart following endurance exercise training of both high and moderate intensity.

METHODS AND RESULTS

C57BL/6J mice were subjected to 10 wk treadmill running, either high intensity interval training (HIT) or distance-matched moderate intensity training (MIT), where HIT led to a pronounced increase in maximal oxygen uptake. Although both modes of exercise were associated with a 10% increase in heart weight-to-body weight ratio, only HIT altered cardiac substrate utilization, as revealed by a 36% increase in glucose oxidation and a concomitant reduction in fatty acid oxidation. HIT also improved cardiac efficiency by decreasing work-independent myocardial oxygen consumption. In addition, it increased cardiac maximal mitochondrial respiratory capacity.

CONCLUSION

This study shows that high intensity training is required for induction of changes in cardiac substrate utilization and energetics, which may contribute to the superior effects of high compared with moderate intensity training in terms of increasing aerobic capacity.