Surgical sensation during caesarean section: a qualitative analysis

BACKGROUND

Caesarean section (CS) is a major abdominal surgery performed usually on a young and healthy population under neuraxial anesthesia with little to no sedation. This creates a distinct surgical experience whereby patients are aware of the surgical process, physical sensations, and their environment. This study aimed to provide an in-depth descriptive assessment of subjective surgical experience during CS under regional anaesthesia. We expected the information gained would enhance our current understanding and better alleviate patient anxiety through informed counselling.

METHODS

This qualitative descriptive study was conducted at a Canadian academic centre. Twenty patients participated in semi-structured interviews within a week of CS, using an interview guide developed for this study. Patient medical records were reviewed to collect demographic and surgical information. Thematic analysis was conducted using an inductive approach to determine common themes.

RESULTS

Nine themes were identified. Five themes were identified in the category of surgical sensation and four themes were identified in the category of peri-operative education.

CONCLUSIONS

Patients commonly experienced pressure and movement sensations at varying intensity, and most did not experience pain. Environmental factors, including sounds and distraction by the newborn, affected perception of surgical sensation. Patients wish to receive pre-operative counselling regarding potential surgical sensations, as well as ongoing communication from their anaesthesiologist. These results can be used to guide informed discussions with patients and direct further investigation in this area.

Inherited CD19 Deficiency Does Not Impair Plasma Cell Formation or Response to CXCL12

BACKGROUND

The human CD19 antigen is expressed throughout B cell ontogeny with the exception of neoplastic plasma cells and a subset of normal plasma cells. CD19 plays a role in propagating signals from the B cell receptor and other receptors such as CXCR4 in mature B cells. Studies of CD19-deficient patients have confirmed its function during the initial stages of B cell activation and the production of memory B cells; however, its role in the later stages of B cell differentiation is unclear.

OBJECTIVE

Using B cells from a newly identified CD19-deficient individual, we investigated the role of CD19 in the generation and function of plasma cells using an in vitro differentiation model.

METHODS

Flow cytometry and long-read nanopore sequencing using locus-specific long-range amplification products were used to screen a patient with suspected primary immunodeficiency. Purified B cells from the patient and healthy controls were activated with CD40L, IL-21, IL-2, and anti-Ig, then transferred to different cytokine conditions to induce plasma cell differentiation. Subsequently, the cells were stimulated with CXCL12 to induce signalling through CXCR4. Phosphorylation of key downstream proteins including ERK and AKT was assessed by Western blotting. RNA-seq was also performed on in vitro differentiating cells.

RESULTS

Long-read nanopore sequencing identified the homozygous pathogenic mutation c.622del (p.Ser208Profs*19) which was corroborated by the lack of CD19 cell surface staining. CD19-deficient B cells that are predominantly naïve generate phenotypically normal plasma cells with expected patterns of differentiation-associated genes and normal levels of CXCR4. Differentiated CD19-deficient cells were capable of responding to CXCL12; however, plasma cells derived from naïve B cells, both CD19-deficient and sufficient, had relatively diminished signaling compared to those generated from total B cells. Additionally, CD19 ligation on normal plasma cells results in AKT phosphorylation.

CONCLUSION

CD19 is not required for generation of antibody-secreting cells or the responses of these populations to CXCL12, but may alter the response other ligands that require CD19 potentially affecting localization, proliferation, or survival. The observed hypogammaglobulinemia in CD19-deficient individuals is therefore likely attributable to the lack of memory B cells.

Development and validation of a prognostic model for death 30 days after adult emergency laparotomy

The probability of death after emergency laparotomy varies greatly between patients. Accurate pre-operative risk prediction is fundamental to planning care and improving outcomes. We aimed to develop a model limited to a few pre-operative factors that performed well irrespective of surgical indication: obstruction; sepsis; ischaemia; bleeding; and other. We derived a model with data from the National Emergency Laparotomy Audit for patients who had emergency laparotomy between December 2016 and November 2018. We tested the model on patients who underwent emergency laparotomy between December 2018 and November 2019. There were 4077/40,816 (10%) deaths 30 days after surgery in the derivation cohort. The final model had 13 pre-operative variables: surgical indication; age; blood pressure; heart rate; respiratory history; urgency; biochemical markers; anticipated malignancy; anticipated peritoneal soiling; and ASA physical status. The predicted mortality probability deciles ranged from 0.1% to 47%. There were 1888/11,187 deaths in the test cohort. The scaled Brier score, integrated calibration index and concordance for the model were 20%, 0.006 and 0.86, respectively. Model metrics were similar for the five surgical indications. In conclusion, we think that this prognostic model is suitable to support decision-making before emergency laparotomy as well as for risk adjustment for comparing organisations.

Severity of Dementia and Survival in Patients Diagnosed with Colorectal Cancer: A National Cohort Study in England and Wales

AIMS

There is little evidence about the survival of patients with colorectal cancer (CRC) also diagnosed with dementia. We quantified dementia severity and estimated how it is associated with 2-year overall survival.

MATERIALS AND METHODS

Records of patients aged 65 years or older diagnosed with CRC in England and Wales were identified. A novel proxy for dementia severity combined dementia diagnosis in administrative hospital data with Eastern Cooperative Oncology Group performance status. Cox regression was used to estimate hazard ratios with and without risk adjustment.

RESULTS

In total, 4033 of 105 250 CRC patients (3.8%) had dementia recorded. Two-year survival decreased with increasing dementia severity from 65.4% without dementia, 53.5% with mild dementia, 33.0% with moderate dementia to 16.5% with severe dementia (hazard ratio comparing severe with no dementia: 2.97; 95% confidence interval 2.79, 3.16). Risk adjustment for comorbidity and cancer stage reduced this association slightly (hazard ratio 2.52; 95% confidence interval 2.37, 2.68) and additional adjustment for treatment factors reduced it further (hazard ratio 1.60; 95% confidence interval 1.50, 1.70).

CONCLUSIONS

Survival of CRC patients varied strongly according to dementia severity, suggesting that a 'one-size-fits-all' policy for the care of CRC patients with dementia is not appropriate. Comprehensive assessment of cancer patients with dementia that considers dementia severity is essential in a shared decision-making process that ensures patients receive the most appropriate treatment for their individual needs and preferences.

Iatrogenic and spontaneous preterm birth in England: a population-based cohort study

OBJECTIVE

To describe the rates of and risk factors associated with iatrogenic and spontaneous preterm birth and the variation in rates between hospitals.

DESIGN

Cohort study using electronic health records.

SETTING

English National Health Service.

POPULATION

Singleton births between 1^st April 2015 and 31^st March 2017.

METHODS

Multivariable Poisson regression models were used to estimate adjusted risk ratios (adjRR) to measure association with maternal demographic and clinical risk factors.

MAIN OUTCOME MEASURES

Preterm births (<37 weeks gestation) were defined as iatrogenic or spontaneous according to mode of onset of labour.

RESULTS

6.1% of births were preterm and of these, 52.8% were iatrogenic. The proportion of preterm births that were iatrogenic increased after 32 weeks. Both sub-groups are associated with previous preterm birth, extremes of maternal age, socioeconomic deprivation and smoking. Iatrogenic preterm birth was associated with higher BMI (adjRR BMI >40 1.59 (1.50, 1.69)), and previous caesarean (adjRR 1.88 (1.83, 1.95)). Spontaneous preterm birth was less common in women with a higher BMI (adjRR BMI>40 0.77 (0.70, 0.84)) and in women with a previous caesarean (adjRR 0.87 (0.83, 0.90)). More variation between NHS hospital trusts was observed in rates of iatrogenic, compared to spontaneous, preterm births.

CONCLUSIONS

Just over half of all preterm births resulted from iatrogenic intervention. Iatrogenic births have overlapping but different patterns of maternal demographic and clinical risk factors to spontaneous preterm births. Iatrogenic and spontaneous sub-groups should therefore be measured and monitored separately, as well as in aggregate, to facilitate different prevention strategies. This is feasible using routinely acquired hospital data.

First Leptophobic Dark Matter Search from the Coherent-CAPTAIN-Mills Liquid Argon Detector

We report the first results of a search for leptophobic dark matter (DM) from the Coherent-CAPTAIN-Mills (CCM) liquid argon (LAr) detector. An engineering run with 120 photomultiplier tubes (PMTs) and 17.9×10^{20} protons on target (POT) was performed in fall 2019 to study the characteristics of the CCM detector. The operation of this 10-ton detector was strictly light based with a threshold of 50 keV and used coherent elastic scattering off argon nuclei to detect DM. Despite only 1.5 months of accumulated luminosity, contaminated LAr, and nonoptimized shielding, CCM's first engineering run has already achieved sensitivity to previously unexplored parameter space of light dark matter models with a baryonic vector portal. With an expected background of 115 005 events, we observe 115 005+16.5 events which is compatible with background expectations. For a benchmark mediator-to-DM mass ratio of m_{V_{B}}/m_{χ}=2.1, DM masses within the range 9  MeV≲m_{χ}≲50  MeV are excluded at 90% C. L. in the leptophobic model after applying the Feldman-Cousins test statistic. CCM's upgraded run with 200 PMTs, filtered LAr, improved shielding, and 10 times more POT will be able to exclude the remaining thermal relic density parameter space of this model, as well as probe new parameter space of other leptophobic DM models.

Face Value: Remote facial expression analysis adds predictive power to perceived effectiveness for selecting anti-tobacco PSAs

Perceived effectiveness (PE) is a validated tool for predicting the potential impact of anti-tobacco public service announcements (PSAs). We set out to evaluate the added predictive value of facial expression analysis when combined with PE in a remote (online) survey. Each of 302 tobacco users watched 3 PSAs and allowed transmission of webcam videos from which metrics for "attention" (head position) and "facial action units" (FAU) were computed. The participants completed scales for their subjective emotions, willingness to share on social media, and intention to quit smoking using the Tobacco Free Florida website. Based on PE, both ready to quit (RTQ) and not ready (NR) respondents favored the same PSAs but RTQs assigned higher PE scores. Negative PSAs ("sad" or "frightening") were more compelling overall but RTQs also favored surprising ads and were more willing to share them on social media. Logistic regression showed that the combination of Attention + FAU+ PE (AUC = .816, p < .0001) outperformed single factors or factor combinations in distinguishing RTQ from NR. This study demonstrates that on-line assessment of facial expressions enhances the predictive value of PE and can be deployed on large remote samples.

A234 IN VITRO GUT MICROBIOME AND METABOLITE RESPONSES TO RESISTANT STARCH ARE INDIVIDUALIZED

Background

Gut microbes degrade and ferment resistant starch (RS) into metabolites that help maintain gut homeostasis. Clinical trials have evaluated RS for various health conditions, but individuals respond to RS with profound variability. The reason for this variability is unclear.

Aims

Using in vitro culturing methods and multi-omic analyses, we hypothesize that individuals will elicit variable responses to RS with respect to overall fermentation, bacterial composition, short chain acid production, and metabolite flux.

Methods

As part of an ongoing clinical trial, we have selected 4 pediatric patients with inflammatory bowel disease to better understand microbiome-RS interactions. We cultured stools anaerobically using a high-throughput platform (“RapidAIM”) with 9 different pre-digested RS. After 18-hour incubations, media supernatants were used to measure pH and perform targeted and semi-targeted metabolomic analyses with a panel of 116 compounds. Bacterial pellets were isolated for 16S rRNA gene sequencing analyses to evaluate changes in microbiome compositions. Data were analyzed with generalized linear mixed models, principal component analysis (PCA), random forest (RF) classification with feature selection, and network construction with graphical lasso.

Results

Changes in several microbiome parameters were different across individuals, including the magnitude of pH changes, metabolite signatures, and relative abundances of important bacterial taxa. Bacterial species known to degrade RS were more abundant in individuals showing stronger RS fermentation. Inter-individual discrimination was accomplished with PCA and RF, from which we could identify metabolite signatures. The robustness of microbiome networks corresponded to RS fermentation and butyrate production.

Conclusions

We report a novel perspective on how individuals respond to RS’ differently. Butyrate remains an important hub of the microbiome architecture with respect to RS fermentation. Future work will interrogate the roles of individualized metabolomic responses on host physiology. In vivo responses to RS are being evaluated in an ongoing clinical trial.

Funding Agencies

CCC, CIHRGenome Ontario, Genome Canada

A System for In Vitro Generation of Mature Murine Plasma Cells Uncovers Differential Blimp-1/Prdm1 Promoter Usage

Upon encounter with Ag, B cells undergo a sequential process of differentiation to become Ab-secreting plasma cells. Although the key drivers of differentiation have been identified, research has been limited by the lack of in vitro models recapitulating the full process for murine B cells. In this study, we describe methodology using BCR or TLR ligation to obtain plasma cells that are phenotypically mature, have exited cell cycle and express a gene signature concordant with long-lived plasma cells. Dependent on the initial stimuli, the transcriptomes also show variation including the enhanced expression of matrisome components after BCR stimulation, suggestive of unique functional properties for the resultant plasma cells. Moreover, using the new culture conditions we demonstrate that alternative promoter choice regulating the expression of the master transcription factor Blimp-1/Prdm1 can be observed; when the canonical B cell promoter for Prdm1 is deleted, differentiating B cells exhibit flexibility in the choice of promoter, dictated by the initiating stimulus, with preferential maintenance of expression following exposure to TLR ligation. Thus our system provides a readily tractable model for furthering our understanding of plasma cell biology.

751 Improving Engagement with Home-Based Surgical Skills Simulation

Introduction

Surgical simulation has been repeatedly shown to facilitate technical skill acquisition. However, trainee engagement with self-directed practice remains variable, despite access to resources. Understanding the motivators and barriers to participation is crucial to develop modules which can effectively meet the learning needs of current, and future, surgical trainees. The aim of this qualitative study was to examine factors which influence trainee engagement with home-based surgical skills simulation.

Method

A series of one-to-one semi-structured interviews were conducted remotely with ST3 vascular trainees who had previously consented to take part in a national programme of home-based technical skills simulation. Interview data was transcribed and thematically analysed.

Results

12 trainees were interviewed during a 4-week period. Overall, trainees valued simulation but found it difficult to balance against clinical commitments and mandatory training requirements, particularly if there were limited opportunities for skill transfer to the real-world environment. Although simulation was acknowledged to be a safe environment for experiential learning, trainees alluded to an underlying culture of perfection which limited willingness to learn from mistakes, even within a simulated setting. In addition, traditional attitudes about the apprenticeship model of surgical training prevail, with simulation often viewed as inferior to learning “on the job” in theatre.

Conclusions

Trainee engagement with home-based surgical skills simulation may be influenced by a range of systemic factors. In future, formal certification of simulation modules, mandating simulated competencies and curricular integration may help improve participation, as well as supporting cultural shift towards recognition of simulation as a vital component of modern surgical training.

Associations between ethnicity and admission to intensive care among women giving birth: a cohort study

OBJECTIVE

To determine the association between ethnic group and likelihood of admission to intensive care in pregnancy and the postnatal period.

DESIGN

Cohort study.

SETTING

Maternity and intensive care units in England and Wales.

POPULATION OR SAMPLE

A total of 631 851 women who had a record of a registerable birth between 1 April 2015 and 31 March 2016 in a database used for national audit.

METHODS

Logistic regression analyses of linked maternity and intensive care records, with multiple imputation to account for missing data.

MAIN OUTCOME MEASURES

Admission to intensive care in pregnancy or postnatal period to 6 weeks after birth.

RESULTS

In all, 2.24 per 1000 maternities were associated with intensive care admission. Black women were more than twice as likely as women from other ethnic groups to be admitted (odds ratio [OR] 2.21, 95% CI 1.82-2.68). This association was only partially explained by demographic, lifestyle, pregnancy and birth factors (adjusted OR 1.69, 95% CI 1.37-2.09). A higher proportion of intensive care admissions in Black women were for obstetric haemorrhage than in women from other ethnic groups.

CONCLUSIONS

Black women have an increased risk of intensive care admission that cannot be explained by demographic, health, lifestyle, pregnancy and birth factors. Clinical and policy intervention should focus on the early identification and management of severe illness, particularly obstetric haemorrhage, in Black women, in order to reduce inequalities in intensive care admission.

TWEETABLE ABSTRACT

Black women are almost twice as likely as White women to be admitted to intensive care during pregnancy and the postpartum period; this risk remains after accounting for demographic, health, lifestyle, pregnancy and birth factors.

Epidemiology and pathogenesis of stroke in preterm infants: A systematic review

BACKGROUND:

Perinatal stroke is one of the principal causes of cerebral palsy (CP) in preterm infants. Stroke in preterm infants is different from stroke in term infants, given the differences in brain maturation and the mechanisms of injury exclusive to the immature brain. We conducted a systematic review to explore the epidemiology and pathogenesis of periventricular hemorrhagic infarction (PVHI), perinatal arterial ischemic stroke (PAIS) and cerebral sinovenous thrombosis (CSVT) in preterm infants.

METHODS:

Studies were identified based on predefined study criteria from MEDLINE, EMBASE, SCOPUS and WEB OF SCIENCE electronic databases from 2000 –2019. Results were combined using descriptive statistics.

RESULTS:

Fourteen studies encompassed 546 stroke cases in preterm infants between 23 –36 weeks gestational ages and birth weights between 450 –3500 grams. Eighty percent (436/546) of the stroke cases were PVHI, 17%(93/546) were PAIS and 3%(17/546) were CSVT. Parietal PVHI was more common than temporal and frontal lobe PVHI. For PAIS, left middle cerebral artery (MCA) was more common than right MCA or cerebellar stroke. For CSVT partial or complete thrombosis in the transverse sinus was universal. All cases included multiple possible risk factors, but the data were discordant precluding aggregation within a meta-analysis.

CONCLUSION:

This systematic review confirms paucity of data regarding the etiology and the precise causal pathway of stroke in preterm infants. Moreover, the preterm infants unlike the term infants do not typically present with seizures. Hence high index of clinical suspicion and routine cUS will assist in the timely diagnosis and understanding of stroke in this population.

Hemispheric asymmetry in ocean change and the productivity of ecosystem sentinels

Climate change and other human activities are causing profound effects on marine ecosystem productivity. We show that the breeding success of seabirds is tracking hemispheric differences in ocean warming and human impacts, with the strongest effects on fish-eating, surface-foraging species in the north. Hemispheric asymmetry suggests the need for ocean management at hemispheric scales. For the north, tactical, climate-based recovery plans for forage fish resources are needed to recover seabird breeding productivity. In the south, lower-magnitude change in seabird productivity presents opportunities for strategic management approaches such as large marine protected areas to sustain food webs and maintain predator productivity. Global monitoring of seabird productivity enables the detection of ecosystem change in remote regions and contributes to our understanding of marine climate impacts on ecosystems.

256 Antimicrobial Stewardship in Skin Cancer Surgery. Assessing Best Practice in Reducing Significant Post-Operative Complications

Introduction

Antibiotic prescription is variable and with the growing frequency of antibiotic resistance, responsible use of antibiotics is necessary in keeping with Public Health England (PHE) Antimicrobial Stewardship guidelines. An audit was conducted to assess current practice of prophylactic antibiotics prescription in Skin Cancer Surgery in the department of Oral & Maxillofacial surgery.

Method

A retrospective case note review of patients who had undergone reconstructive surgery following skin cancer excision, recorded use of systemic and topical antibiotics and infective outcomes. Inclusion criteria were patients that had undergone surgical excision and reconstruction of skin cancer, followed by a wound assessment in an outpatient’s clinic with the outcome measure of infection defined by PHE Surgical Site Infection guidelines. A standard of 5% infection rate which is recognised by the British Association of Dermatologists was used.

Results

There was a 2% significant post op infection rate in patients with topical antibiotics used and 4.5% where neither systemic nor topical antibiotics were used. Immunocompromised patients had no increased incidence in significant post op infections occurring in either group.

Conclusions

The standard was met illustrating the low infection rate following reconstruction of Skin Cancer defects with or without prophylactic antibiotics and support a more discerning approach to antimicrobial prescribing.

525 Automated Continuous Instrument Tracking in Laparoscopic Box Trainers Predicts Performance at Assessment: A Prospective Cohort Study in Core Surgical Trainees

Introduction

Box-trainers enable deliberate practice of laparoscopic skills and can be equipped with instrument tracking metrics to provide feedback. However, the relationship between metrics, assessment outcomes and practice are unclear.

Method

Core surgical trainees were provided take-home box trainers with SurgTrac™ instrument tracking metrics for practice (eoSurgical Ltd., Scotland, UK). Practice was incentivised by certification and video assessment of a basic task, peg capping. Assessment was by consultant general surgeons, using objective structured assessment of technical skills (OSATS). The following metrics were analysed: task duration, distance moved by instruments, average instrument speed, average instrument acceleration, left- or right-handedness and instrument smoothness. Metrics were correlated to OSATS scores using regression analysis. Threshold for significance was p = 0.05.

Results

During the study period, there were 1639 peg capping performances by 85 trainees; 103 video recordings were submitted for assessment. All metrics were significantly associated with OSATS score, except instrument acceleration. The multiple linear regression model was highly correlated with actual scores (Pearson correlation 0.658; p &lt; 0.001). Practice was positively correlated with regression model predicted OSATS score (regression analysis; ANOVA p &lt; 0.001).

Conclusions

Instrument tracking metrics reliably predict OSATS performance and practice improves predicted score. Trainees can use metrics in unsupervised practice and gauge whether they are improving as expected.

Biallelic mutations in calcium release activated channel regulator 2A (CRACR2A) cause a primary immunodeficiency disorder

CRAC channel regulator 2 A (CRACR2A) is a large Rab GTPase that is expressed abundantly in T cells and acts as a signal transmitter between T cell receptor stimulation and activation of the Ca²⁺-NFAT and JNK-AP1 pathways. CRACR2A has been linked to human diseases in numerous genome-wide association studies, however, to date no patient with damaging variants in CRACR2A has been identified. In this study, we describe a patient harboring biallelic variants in CRACR2A [paternal allele c.834 gaG> gaT (p.E278D) and maternal alelle c.430 Aga > Gga (p.R144G) c.898 Gag> Tag (p.E300*)], the gene encoding CRACR2A. The 33-year-old patient of East-Asian origin exhibited late onset combined immunodeficiency characterised by recurrent chest infections, panhypogammaglobulinemia and CD4+ T cell lymphopenia. In vitro exposure of patient B cells to a T-dependent stimulus resulted in normal generation of antibody-secreting cells, however the patient's T cells showed pronounced reduction in CRACR2A protein levels and reduced proximal TCR signaling, including dampened SOCE and reduced JNK phosphorylation, that contributed to a defect in proliferation and cytokine production. Expression of individual allelic mutants in CRACR2A-deleted T cells showed that the CRACR2A^E278D mutant did not affect JNK phosphorylation, but impaired SOCE which resulted in reduced cytokine production. The truncated double mutant CRACR2A^R144G/E300* showed a pronounced defect in JNK phosphorylation as well as SOCE and strong impairment in cytokine production. Thus, we have identified variants in CRACR2A that led to late-stage combined immunodeficiency characterized by loss of function in T cells.

Astrocyte-Derived Exosomes in an iPSC Model of Bipolar Disorder

Bipolar I Disorder (BP) is a serious, recurrent mood disorder that is characterized by alternating episodes of mania and depression. To begin to identify novel approaches and pathways involved in BP, we have obtained skin samples from BP patients and undiagnosed control (C) individuals, reprogrammed them to form induced pluripotent stem cells (iPSC), and then differentiated the stem cells into astrocytes. RNAs from BP and C astrocytes were extracted and RNAseq analysis carried out. 501 differentially expressed genes were identified, including genes for cytoskeletal elements, extracellular matrix, signaling pathways, neurodegeneration, and notably transcripts that identify exosomes. When we compared highly expressed genes using hierarchial cluster analysis, "Exosome" was the first and most highly significant cluster identified, p < 5 × 10^-13, Benjamini correction. Exosomes are membrane-bound vesicles that package and remove toxic proteins from cells and also enable cell to cell communication. They carry genetic material, including DNA, mRNA and microRNAs, proteins, and lipids to target cells throughout the body. Exosomes are released by cortical neurons and astrocytes in culture and are present in BP vs C postmortem brain tissue. Little is known about what transcripts and proteins are targeted to neurons, how they regulate biological functions of the acceptor cell, or how that may be altered in mood disorders. Since astrocyte-derived exosomes have been suggested to promote neuronal plasticity, as well as to remove toxic proteins in the brain, alterations in their function or content may be involved in neurodevelopmental, neuropathological, and neuropsychiatric conditions. To examine exosome cargos and interactions with neural precursor cells, astrocytes were differentiated from four bipolar disorder (BP) and four control (C) iPSC lines. Culture supernatants from these astrocytes were collected, and exosomes isolated by ultra-centrifugation. Western blot analysis demonstrated the presence of the exosome markers CD9, CD81, and Hsp70. Nanosight technology was used to characterize exosomes from each astrocyte cell line, suggesting that exosomes were slightly more concentrated in culture supernatants derived from BP compared with C astrocytes but there was no difference in the mean sizes of the exosomes. Analysis of their function in neuronal differentiation is being carried out by labeling exosomes derived from bipolar patient and control astrocytes and adding them to control neural progenitor cells. Given the current interest in clearing toxic proteins from brains of patients with neurodegenerative disorders, exosomes may present similar opportunities in BP.

TLR-mediated activation of Waldenström macroglobulinemia B cells reveals an uncoupling from plasma cell differentiation

Waldenström macroglobulinemia (WM) is a rare malignancy in which clonal B cells infiltrate the bone marrow and give rise to a smaller compartment of neoplastic plasma cells that secrete monoclonal immunoglobulin M paraprotein. Recent studies into underlying mutations in WM have enabled a much greater insight into the pathogenesis of this lymphoma. However, there is considerably less characterization of the way in which WM B cells differentiate and how they respond to immune stimuli. In this study, we assess WM B-cell differentiation using an established in vitro model system. Using T-cell-dependent conditions, we obtained CD138+ plasma cells from WM samples with a frequency similar to experiments performed with B cells from normal donors. Unexpectedly, a proportion of the WM B cells failed to upregulate CD38, a surface marker that is normally associated with plasmablast transition and maintained as the cells proceed with differentiation. In normal B cells, concomitant Toll-like receptor 7 (TLR7) activation and B-cell receptor cross-linking drives proliferation, followed by differentiation at similar efficiency to CD40-mediated stimulation. In contrast, we found that, upon stimulation with TLR7 agonist R848, WM B cells failed to execute the appropriate changes in transcriptional regulators, identifying an uncoupling of TLR signaling from the plasma cell differentiation program. Provision of CD40L was sufficient to overcome this defect. Thus, the limited clonotypic WM plasma cell differentiation observed in vivo may result from a strict requirement for integrated activation.

SAT0008 INDIVIDUAL FUNCTIONS OF THE HISTONE-ACETYLTRANSFERASES CBP AND P300 IN REGULATING THE INFLAMMATORY RESPONSE BY AFFECTING HISTONE ACETYLATION AND MRNA STABILITY

Background:

Prolonged TNF-induced H3K27 acetylation (H3K27ac) and increased mRNA stability in rheumatoid arthritis (RA) synovial fibroblasts (SF) are leading to a sustained inflammatory response. Underlying enzymes coordinately regulating these pathways have not been identified so far. The histone acetyltransferases cAMP-response element binding protein binding protein (CBP) and p300 are writers of activating H3K27ac marks and close homologues with widely accepted redundant functions.

Objectives:

To analyze individual functions of CBP and p300 in regulating the inflammatory response of RA SF.

Methods:

SF were isolated from patients with RA undergoing joint replacement surgery. The expression of CBP and p300 was silenced by transfection of antisense LNA gapmeRs (12.5 nM). SF were stimulated with TNF (10 ng/ml) for 24h. Actinomycin D (10 µg/ml) was added 4h after TNF-treatment for 2h and 4h (n=3) to test mRNA stability. Transcriptomes were determined by RNA-seq (Illumina NovaSeq 6000, n=6). We mapped raw reads from RNA-seq reference genome using STAR. Counts for genes were obtained using Feature counts. We searched for differential expression genes (DEG) across experimental conditions using general linear models (glm) implemented in ‘edgeR’ package of R. Significantly affected genes (± fold change > 1.5, FDR < 0.05, top 3000 genes included) entered pathway enrichment analysis for Gene Ontology (GO) biological process, and KEGG pathways in DAVID. Changes in the mRNA (n=12-14) and protein expression (n=6-12) were confirmed by quantitative Real-time PCR and ELISA. The levels of activating histone marks H3K27ac and nuclear localization of p50 and p65 were analyzed by Western blotting.

Results:

DEG revealed that silencing of p300 affected the expression of 6026 and 5138 genes in unstimulated and stimulated SF, respectively. In contrast, only 285 and 1911 genes were affected by CBP silencing in unstimulated and stimulated SF, respectively. In TNF-stimulated SF, pathway enrichment analysis of DEG revealed a key role of CBP in regulating the “type I interferon signaling pathway” (p=2.12x10-6). Both, silencing of CBP and p300 regulated genes enriched in the “TNF signaling pathway” (CBP: p=0.005; p300: p=0.031). In contrast to CBP silencing that had anti-inflammatory effects, silencing of p300 had pro-and anti-inflammatory effects. ELISA experiments suggested that silencing of CBP reduced the secretion of IL6 (p<0.01), CCL2, CXC3L1 (p<0.05), and CXCL12 (p<0.001). Silencing of p300 reduced the secretion of CCL2 (p<0.001) and CXC3L1 (p<0.05) but increased the expression of IL8 (p<0.001) and CXCL2 (p<0.05). Western blotting revealed that neither CBP, nor p300 silencing affected the nuclear expression of the NF-ĸB subunits p65 and p50. Silencing of p300 reduced the levels of H3K27ac by 30% in unstimulated SF, and by 61.4% (p<0.05) in presence of TNF. In addition to regulating H3K27ac, silencing of p300 regulated the expression of TNF-induced cytokines by increasing the mRNA stability of IL8, IL6 and CCL2 mRNA but not of CXCL2. Silencing of CBP reduced H3K27ac by 43.5% only in presence of TNF and did not affect TNF-induced mRNA stability of cytokines. This is in line with the enrichment of the GO biological process “regulation of mRNA stability” (p=2.61x10-8) being enriched only after silencing of p300.

Conclusion:

Our results suggested that p300 is the major writer for H3K27ac marks in SF. Additionally, p300 regulated cytokine expression by affecting mRNA stability in a target-specific manner. We identified overlapping and distinct functions for CBP and p300 in regulating the inflammatory response of SF.

Disclosure of Interests:

Monika Krosel: None declared, Marcel Gabathuler: None declared, Kellie Walker: None declared, Matija Tomsic: None declared, Oliver Distler Grant/research support from: Grants/Research support from Actelion, Bayer, Boehringer Ingelheim, Competitive Drug Development International Ltd. and Mitsubishi Tanabe; he also holds the issued Patent on mir-29 for the treatment of systemic sclerosis (US8247389, EP2331143)., Consultant of: Consultancy fees from Actelion, Acceleron Pharma, AnaMar, Bayer, Baecon Discovery, Blade Therapeutics, Boehringer, CSL Behring, Catenion, ChemomAb, Curzion Pharmaceuticals, Ergonex, Galapagos NV, GSK, Glenmark Pharmaceuticals, Inventiva, Italfarmaco, iQvia, medac, Medscape, Mitsubishi Tanabe Pharma, MSD, Roche, Sanofi and UCB, Speakers bureau: Speaker fees from Actelion, Bayer, Boehringer Ingelheim, Medscape, Pfizer and Roche, Caroline Ospelt Consultant of: Consultancy fees from Gilead Sciences., Kerstin Klein: None declared

Liver transplantation outcomes after transarterial chemotherapy for hepatocellular carcinoma

Background

Transarterial chemoembolization (TACE) in patients with hepatocellular carcinoma (HCC) awaiting liver transplantation is widespread, although evidence that it improves outcomes is lacking and there exist concerns about morbidity. The impact of TACE on outcomes after transplantation was evaluated in this study.

Methods

Patients with HCC who had liver transplantation in the UK were identified, and stratified according to whether they received TACE between 2006 and 2016. Cox regression methods were used to estimate hazard ratios (HRs) for death and graft failure after transplantation adjusted for donor and recipient characteristics.

Results

In total, 385 of 968 patients (39·8 per cent) received TACE. Five-year patient survival after transplantation was similar in those who had or had not received TACE: 75·2 (95 per cent c.i. 68·8 to 80·5) and 75·0 (70·5 to 78·8) per cent respectively. After adjustment for donor and recipient characteristics, there were no differences in mortality (HR 0·96, 95 per cent c.i. 0·67 to 1·38; P = 0·821) or graft failure (HR 1·01, 0·73 to 1·40; P = 0·964). The number of TACE treatments (2 or more versus 1: HR 0·97, 0·61 to 1·55; P = 0·903) or the time of death after transplantation (within or after 90 days; P = 0·291) did not alter the outcome. The incidence of hepatic artery thrombosis was low in those who had or had not received TACE (1·3 and 2·4 per cent respectively; P = 0·235).

Conclusion

TACE delivered to patients with HCC before liver transplant did not affect complications, patient death or graft failure after transplantation.

Acute and chronic effects of multivitamin/mineral supplementation on objective and subjective energy measures

Background

Vitamins and minerals play an essential role within many cellular processes including energy production and metabolism. Previously, supplementation with a multivitamin/mineral (MVM) for ≥28 days resulted in improvements to cognition and subjective state. We have also demonstrated shifts in metabolism during cognitively demanding tasks following MVM in females, both acutely and following 8-week supplementation. The current study aimed to assess these effects further in males and females using metabolically challenging exercise and cognitive tasks.

Methods

The current randomised, placebo-controlled, parallel groups study investigated the effects of a MVM complex in 82 healthy young (18-35y) exercisers. Subjective ratings and substrate metabolism were assessed during 30 min each of increasingly effortful incremental exercise and demanding cognitive tasks. Assessments took place on acute study days following a single dose (Day 1) of MVM, containing 3 times recommended daily allowance of water-soluble vitamins plus CoQ10, and following 4-week supplementation (Day 28).

Results

Energy expenditure (EE) was increased during cognitive tasks following MVM across Day 1 and Day 28, with greater effects in males. In males, MVM also increased carbohydrate oxidation and energy expenditure during exercise across Day 1 and Day 28. In females, mental tiredness was lower during exercise; increases in physical tiredness following 30 min of exercise were attenuated; and stress ratings following cognitive tasks were reduced following MVM. In males, MVM only lowered mental tiredness following 10 min of exercise. These effects were apparent irrespective of day, but effects on mental tiredness were greater on Day 28. Ferritin levels were also higher on Day 28 in those receiving MVM.

Conclusion

These findings extend on existing knowledge, demonstrating increased carbohydrate oxidation and increased energy expenditure in males following MVM supplementation for the first time. Importantly, they show modulation of energy expenditure and subjective tiredness following a single dose, providing further evidence for acute effects of MVM. Differential effects in men and women suggest that sex may play an important role in the effects of MVM on energy metabolism and should be considered in future research.

Trial registration

ClinicalTrials.gov, NCT03003442. Registered 22nd November 2016 – retrospectively registered

Short- and long-term mortality after liver transplantation in patients with and without hepatocellular carcinoma in the UK

Background

The increasing demand for liver transplantation has led to considerable changes in characteristics of donors and recipients. This study evaluated the short- and long-term mortality of recipients with and without hepatocellular carcinoma (HCC) in the UK between 1997 and 2016.

Methods

First-time elective adult liver transplant recipients in the UK were identified and four successive eras of transplantation were compared. Hazard ratios (HRs) comparing the impact of era on short-term (first 90 days) and longer-term (from 90 days to 5 years) mortality were estimated, with adjustment for recipient and donor characteristics.

Results

Some 1879 recipients with and 7661 without HCC were included. There was an increase in use of organs donated after circulatory death (DCD), from 0 per cent in era 1 to 35·2 per cent in era 4 for recipients with HCC, and from 0·2 to 24·1 per cent for non-HCC recipients. The 3-year mortality rate decreased from 28·3 per cent in era 1 to 16·9 per cent in era 4 (adjusted HR 0·47, 95 per cent c.i. 0·35 to 0·63) for recipients with HCC, and from 20·4 to 9·3 per cent (adjusted HR 0·44, 0·36 to 0·53) for those without HCC. Comparing era 4 with era 1, improvements were more marked in short-term than in long-term mortality, both for recipients with HCC (0–90 days: adjusted HR 0·20, 0·10 to 0·39; 90 days to 5 years: adjusted HR 0·52, 0·35 to 0·75; P = 0·043) and for non-HCC recipients (0–90 days: adjusted HR 0·32, 0·24 to 0·42; 90 days to 5 years: adjusted HR 0·52, 0·40 to 0·67; P = 0·024).

Conclusion

In the past 20 years, the mortality rate after liver transplantation has more than halved, despite increasing use of DCD donors. Improvements in overall survival can be explained by decreases in short-term and longer-term mortality.

High Pressure Liquid Chromatographic Determination of Glycyrrhizic Acid or Glycyrrhizic Acid Salts in Various Licorice Products: Collaborative Study

A collaborative study determining glycyrrhizic acid or glycyrrhizic acid salts content of various licorice products has been conducted using high pressure liquid chromatography (HPLC). Five samples containing various concentrations of glycyrrhizic acid were analyzed in blind replicates by 8 collaborators. The results indicate excellent repeatability and reproducibility with coefficients of variation less than 7.5%. In addition, this method allows the determination of glycyrrhizic acid in less than 15 min compared with 3 days for the conventional gravimetric and colorimetric methods. The method has been adopted official first action.

The Scottish Academic Foundation Year Programme: what, why and how?

The Foundation Programme is well established in the UK and serves as the generic training scheme into which newly qualified doctors enter after gaining a medical degree. Although individual programmes have many differences, the range of competencies needing to be fulfilled to progress is uniform across Scotland and the rest of the UK. Some final year medical undergraduates may apply for the Academic Foundation Programme; this is designed to facilitate exposure to academic medicine over and above the clinical experience offered to Foundation Year doctors. This paper describes characteristics of the Academic Foundation Programme in general, with a particular focus on Scotland, which is one Foundation School.

Implementation and dissemination of an African American popular opinion model to improve lupus awareness: an academic-community partnership

OBJECTIVE

Lupus is a chronic, autoimmune disease that disproportionately affects African Americans. We adapted the Centers for Disease Control and Prevention's Popular Opinion Leader model to implement an intervention tailored for African American individuals that leverages an academic-community partnership and community-based social networks to disseminate culturally appropriate lupus education.

METHODS

Academic rheumatologists, social scientists, and researchers in Boston, MA and Chicago, IL partnered with local lupus support groups, community organizations, and churches in neighborhoods with higher proportions of African Americans to develop curriculum and recruit community leaders with and without lupus (Popular Opinion Leaders; POLs). POLs attended four training sessions focused on lupus education, strategies to educate others, and a review of research methods. POLs disseminated information through their social networks and recorded their impact, which was mapped using a geographic information system framework.

RESULTS

We trained 18 POLs in greater Boston and 19 in greater Chicago: 97% were African American, 97% were female; and the mean age was 57 years. Fifty-nine percent of Boston POLs and 68% of Chicago POLs had lupus. POLs at both sites engaged members of their social networks and communities in conversations about lupus, health disparities, and the importance of care. Boston POLs documented 97 encounters with 547 community members reached. Chicago POLs documented 124 encounters with 4083 community members reached.

CONCLUSIONS

An adapted, community-based POL model can be used to disseminate lupus education and increase awareness in African American communities. Further research is needed to determine the degree to which this may begin to reduce disparities in access to care and outcomes.

The timing of liver resection in patients with colorectal cancer and synchronous liver metastases: a population-based study of current practice and survival

AIM

There is uncertainty regarding the optimal sequence of surgery for patients with colorectal cancer (CRC) and synchronous liver metastases. This study was designed to describe temporal trends and inter-hospital variation in surgical strategy, and to compare long-term survival in a propensity score-matched analysis.

METHOD

The National Bowel Cancer Audit dataset was used to identify patients diagnosed with primary CRC between 1 January 2010 and 31 December 2015 who underwent CRC resection in the English National Health Service. Hospital Episode Statistics data were used to identify those with synchronous liver-limited metastases who underwent liver resection. Survival outcomes of propensity score-matched groups were compared.

RESULTS

Of 1830 patients, 270 (14.8%) underwent a liver-first approach, 259 (14.2%) a simultaneous approach and 1301 (71.1%) a bowel-first approach. The proportion of patients undergoing either a liver-first or simultaneous approach increased over the study period from 26.8% in 2010 to 35.6% in 2015 (P < 0.001). There was wide variation in surgical approach according to hospital trust of diagnosis. There was no evidence of a difference in 4-year survival between the propensity score-matched cohorts according to surgical strategy: bowel first vs simultaneous [hazard ratio (HR) 0.92 (95% CI: 0.80-1.06)] or bowel first vs liver first [HR 0.99 (95% CI: 0.82-1.19)].

CONCLUSION

There is evidence of wide variation in surgical strategy in dealing with CRC and synchronous liver metastases. In selected patients, the simultaneous and liver-first strategies have comparable long-term survival to the bowel-first approach.

Socioeconomic differences in selection for liver resection in metastatic colorectal cancer and the impact on survival

BACKGROUND

Socioeconomic inequalities in colorectal cancer (CRC) survival are well recognised. The aim of this study was to describe the impact of socioeconomic deprivation on survival in patients with synchronous CRC liver-limited metastases, and to investigate if any survival inequalities are explained by differences in liver resection rates.

METHODS

Patients in the National Bowel Cancer Audit diagnosed with CRC between 2010 and 2016 in the English National Health Service were included. Linked Hospital Episode Statistics data were used to identify the presence of liver metastases and whether a liver resection had been performed. Multivariable random-effects logistic regression was used to estimate the odds ratio (OR) of liver resection by Index of Multiple Deprivation (IMD) quintile. Cox-proportional hazards model was used to compare 3-year survival.

RESULTS

13,656 patients were included, of whom 2213 (16.2%) underwent liver resection. Patients in the least deprived IMD quintile were more likely to undergo liver resection than those in the most deprived quintile (adjusted OR 1.42, 95% confidence interval (CI) 1.18-1.70). Patients in the least deprived quintile had better 3-year survival (least deprived vs. most deprived quintile, 22.3% vs. 17.4%; adjusted hazard ratio (HR) 1.20, 1.11-1.30). Adjusting for liver resection attenuated, but did not remove, this effect. There was no difference in survival between IMD quintile when restricted to patients who underwent liver resection (adjusted HR 0.97, 0.76-1.23).

CONCLUSIONS

Deprived CRC patients with synchronous liver-limited metastases have worse survival than more affluent patients. Lower rates of liver resection in more deprived patients is a contributory factor.

Thirty-day mortality in patients undergoing laparotomy for small bowel obstruction

Background

Small bowel obstruction (SBO) is a common indication for emergency laparotomy. There are currently variations in the timing of surgery for patients with SBO and limited evidence on whether delayed surgery affects outcomes. The aim of this study was to evaluate the impact of time to operation on 30-day mortality in patients requiring emergency laparotomy for SBO.

Methods

Data were collected from the National Emergency Laparotomy Audit (NELA) on all patients aged 18 years or older who underwent emergency laparotomy for all forms of SBO between December 2013 and November 2015. The primary outcome measure was 30-day mortality, with date of death obtained from the Office for National Statistics. Patients were grouped according to the time from admission to surgery (less than 24 h, 24–72 h and more than 72 h). A multilevel logistic regression model was used to explore the impact of patient factors, primarily delay to surgery, on 30-day mortality.

Results

Some 9991 patients underwent emergency laparotomy requiring adhesiolysis or small bowel resection for SBO. The overall mortality rate was 7·2 per cent (722 patients). Within each time group, 30-day mortality rates were significantly worse with increasing age, ASA grade, Portsmouth POSSUM score and level of contamination. Patients undergoing emergency laparotomy more than 72 h after admission had a significantly higher risk-adjusted 30-day mortality rate (odds ratio 1·39, 95 per cent c.i. 1·09 to 1·76).

Conclusion

In patients who require an emergency laparotomy with adhesiolysis or resection for SBO, a delay to surgery of more than 72 h is associated with a higher 30-day postoperative mortality rate.

Interaction of H2O with CO: potential energy surface, bound states and scattering calculations

We present the first scattering calculations for the H₂O–CO system based on a high accuracy potential energy surface.

Individuals with a vestibular-related disorder use a somatosensory-dominant strategy for postural orientation after inclined stance

OBJECTIVES

The visual, somatosensory, and vestibular systems are critical for establishing a sensorimotor set for postural control and orientation. The goal of this study was to assess how individuals with a vestibular-related disorder keep their balance following prolonged stance on an inclined surface. We hypothesize that subjects will show greater reliance on the somatosensory system than age-matched controls as inferred by the presence of a forward postural lean aftereffect following the inclined stance (i.e., a positive response).

RESULTS

The results revealed an underlying somatosensory-dominant strategy for postural control in the vestibular group: 100% of the subjects tested positive compared to 58% in the control group (P=.006).

CONCLUSION

Individuals with a vestibular-related disorder use a somatosensory-dominant strategy for postural orientation following prolonged inclined stance. The implications for the management of this population are discussed.