P48 Exploration of variation in Management of Acutely Symptomatic Hernia – results from the MASH practice survey

Introduction

There is minimal evidence to guide the emergency management of groin and abdominal wall hernia. The aim of this project is to understand current variations in clinical practice across the UK when managing common types of acutely symptomatic hernia.

Methods

A survey of clinical practice was developed to explore the management of acutely symptomatic abdominal wall hernia (ASH) including groin (GH), umbilical (UH), and incisional hernia (IH). The survey captured respondent characteristics. It explored preferences in the management of each type of ASH, including factors related to treatment and repair strategy. Surgeons at ST3+ level with a UK practice were invited to participate through Twitter and collaborative networks.

Results

In total, 144 responses were received (response rate 26%). Of these, 62 (43.1%) were Consultant Surgeons, 105 (72.9%) did not have a specialist hernia practice, and 95 (66%) did not follow specific guidelines for emergency hernia repair. There was variation in investigations used e.g. CT required for IH (91%) but less for GH (34.7%) and UH (47.2%). Open repair was preferred in all settings. For GH with ischaemic bowel 76 (52.8%) would suture repair vs. 67 (46.5%) who would use a mesh (64.2% permanent synthetic) this is similar for IH, where 59 (41%) chose suture vs. 71 (49.3%) mesh, although 61.9% favoured biologic mesh for IH. Suture repair was preferred for UH with ischaemic bowel (69.4%).

Conclusion

The survey demonstrates variation in treatment of ASH. Areas which require further exploration include use of mesh and laparoscopy in the emergency setting.

Uncertainty studies on hydrogen source term with MAAP5 code

In the present study, a methodology is developed to quantify the uncertainties of special model parameters of the integral severe accident analysis code MAAP5. Here, the in-vessel hydrogen production during a core melt accident for Lungmen Nuclear Power Station of Taiwan Power Company, an advanced boiling water reactor, is analyzed. Sensitivity studies are performed to identify those parameters with an impact on the output parameter. For this, multiple calculations of MAAP5 are performed with input combinations generated from Latin Hypercube Sampling (LHS). The results are analyzed to determine the 95th percentile with 95% confidence level value of the amount of in-vessel hydrogen production. The calculations show that the default model options for IOXIDE and FGBYPA are recommended. The Pearson Correlation Coefficient (PCC) was used to determine the impact of model parameters on the target output parameters and showed that the three parameters TCLMAX, FCO, FOXBJ are highly influencing the in-vessel hydrogen generation. Suggestions of values of these three parameters are given.

161 Does the Weather Contribute to Admissions of Neck of Femur Fractures?

Introduction

The effects of weather on overall mortality are well documented. Anecdotally, icy conditions are perceived to result in more falls and admissions for neck of femur (NOF) fractures. The aim of this unfunded pilot study was to determine whether relationships could be extracted or at least not ruled out by analysing a small dataset, and so give impetus to a larger project.

Methods

Seven trauma units across north west London were identified and NOF fracture data extracted for five years. Visual inspection of the time series, consideration of the weather on specific days and correlation analysis were used to assess causal links between fracture numbers and a variety of weather parameters (temperature, rainfall, wind and ice risk).

Results

Overall, 10,929 individuals with hip fractures were admitted over the five-year period. The highest number of admissions in a day was 14. No clear association was found between a weather parameter and daily admissions. However, when accumulated to a weekly timescale, a negative relationship with maximum temperature was found. No seasonal cycle was detected.

Conclusion

The lack of a daily relationship and presence of a weekly relationship points to a possible delayed response to weather or insufficient daily data to extract a signal. The inconclusive results also indicate that more socioeconomic data will need to be used in future studies, requiring a larger data sample. In addition, even in cold weather an urban environment may not create icy conditions, being ameliorated by the heat island effect and gritting.

Dynamical ground state in the XY pyrochlore Yb2GaSbO7

The magnetic ground state of the pyrochlore Yb2GaSbO7 has remained an enigma for nearly a decade. The persistent spin fluctuations observed by muon spin relaxation measurements at low temperatures have not been adequately explained for this material using existing theories for quantum magnetism. Here we report on the synthesis and characterisation of Yb2GaSbO7 to elucidate the central physics at play. Through DC and AC magnetic susceptibility, heat capacity, and neutron scattering experiments, we observe evidence for a dynamical ground state that makes Yb2GaSbO7 a promising candidate for disorder-induced spin-liquid or spin-singlet behaviour. This state is quite fragile, being tuned to a splayed ferromagnet in a modest magnetic field μ 0 H c ∼ 1.5 T .

97 Function of species-specific OCT4 reporter system during porcine embryo development

The present study examined the activity and function of pig OCT4 (POU5F1) enhancer in porcine early embryo development. OCT4 is one of the master regulators for the pluripotency of early mammalian embryonic development and embryonic stem cells. It has two regulatory elements: distal enhancer (DE) and proximal enhancer (PE) in the upstream regulatory region. They are activated under different conditions such as naïve and primed. It is known that two enhancers are activated to produce OCT4 simultaneously or sequentially depending on the state of pluripotency. Many porcine OCT4 upstream region-based reporter systems have been reported because this is a necessary part of studying porcine-specific pluripotency. However, the porcine-specific OCT4 reporter system has never been transfected and functionally tested during porcine early embryo development. We performed functional tests of the previously established porcine-specific OCT4 reporter system in the early embryo development stage. Porcine embryos were micro-injected with the pOCT4-ΔPE-eGFP (DE-GFP) containing a distal enhancer and core promoter and pOCT4-ΔDE-DsRed2 (PE-RFP) containing a proximal enhancer and core promoter. They were cultured in PZM-3 at 39°C in a humidified atmosphere, 5% CO2, and 5% O2 for 168h. Fifty of the 100 embryos were injected with OCT4 reporter system as treatment groups and the other 50 were not injected (control groups). We analysed mRNA and protein expression of GFP and RFP using quantitative real-time PCR and confocal microscopy by developmental stages. The introduced reporter system could function beginning with the 4-cell stage. The expression of GFP and RFP was observed simultaneously in the early embryonic development stage up to blastocyst, indicating that porcine OCT4 was produced by distal and proximal enhancers, unlike mouse Oct4 expression, which was only controlled by the distal enhancer during early embryo development. Therefore, the mechanisms and functions of distal and proximal enhancers of porcine OCT4 were different from those of the mouse. This is similar to results of the previous experiment using porcine-induced pluripotent stem cells, which suggest that porcine OCT4 is expressed by two enhancers and in a stage-specific manner during reprogramming and that pigs do not use only one enhancer in pluripotent states, but two enhancers at the same time, and there is only a difference in degree. This work showed that the porcine OCT4 reporter system enables non-destructive analysis during early embryo development and it could be applied to study species-specific pluripotency and to help the establishment of naïve embryonic stem cells in the pig. This work was supported by the BK21 Plus Program, the National Research Foundation of Korea (NRF) grant funded by the Korea government (NRF-2019R1C1C1004514), the Korea Institute of Planning and Evaluation for Technology in Food, Agriculture and Forestry (IPET) through the Development of High Value-Added Food Technology Program funded by the Ministry of Agriculture, Food, and Rural Affairs (MAFRA; 118042-03-3-HD020).

42 Disruption of endogenous SOX2 during porcine embryo development using the CRIPSR/Cas9 system

The lineage specification of the pre-implantation embryo is important to understand the developmental process, but it remains unclear because the expression of lineage-specific genes is distinct among species. Pigs have genetic and physiological traits similar to humans; however, there are differences in gene expression during the pre-implantation stage. To select a candidate gene that affects the formation of the inner cell mass (ICM) in porcine embryo, we conducted preliminary experiments. First, we measured the expression level of candidate genes for lineage specification in parthenogenetic-activated embryos. The expression of pluripotent genes peaked on Day 3 and thereafter decreased gradually. Next, we conducted immunocytochemistry. OCT4 was expressed in all cells in morula and Day 5 blastocyst, but some Day 7 blastocysts expressed OCT4 in both ICM and trophectoderm (TE), whereas others expressed OCT4 only in ICM. NANOG was not observed in the morula stage, whereas SOX2 was located in a restricted area. To examine the effect of SOX2 in ICM formation, we injected plasmid expressing Cas9 and guide (g)RNA using Lipofectamine for efficient transgene expression at the 2-cell stage to increase viability by inducing mosaicism. The expression of enhanced green fluorescent protein (EGFP) contained in the plasmid confirmed that the plasmid was operating normally. In SOX2-knockout (KO) early blastocysts, the numbers of total cells and SOX2- and NANOG-positive cells were greatly decreased, while OCT4 was expressed in most cells. As in early blastocysts, SOX2-KO late blastocysts had fewer cells expressing SOX2, NANOG, and SOX17 than control. To identify the transcriptional consequences of SOX2 reduction, we performed quantitative PCR analysis on non-injected and PX458-gRNA injected blastocysts. Injection of PX458-gRNA resulted in downregulation of NANOG, SOX17, and SMAD7, but not SOX2 and OCT4. Furthermore, proliferation-associated genes were downregulated in injected blastocysts. In conclusion, SOX2-targeted porcine embryos showed blastocoel formation, the inner cell mass formed poorly, and embryos have inefficient cells. Also, the depletion of SOX2 in porcine blastocysts downregulated pluripotent genes and proliferation genes. This work was supported by the BK21 Plus Program, the National Research Foundation of Korea (NRF) grant funded by the Korea government (NRF-2019R1C1C1004514), the Korea Institute of Planning and Evaluation for Technology in Food, Agriculture and Forestry (IPET) through the Development of High Value-Added Food Technology Program funded by the Ministry of Agriculture, Food, and Rural Affairs (MAFRA; 118042-03-3-HD020).

High-frequency gas effusion through nanopores in suspended graphene

Porous, atomically thin graphene membranes have interesting properties for filtration and sieving applications. Here, graphene membranes are used to pump gases through nanopores using optothermal forces, enabling the study of gas flow through nanopores at frequencies above 100 kHz. At these frequencies, the motion of graphene is closely linked to the dynamic gas flow through the nanopore and can thus be used to study gas permeation at the nanoscale. By monitoring the time delay between the actuation force and the membrane mechanical motion, the permeation time-constants of various gases through pores with diameters from 10–400 nm are shown to be significantly different. Thus, a method is presented for differentiating gases based on their molecular mass and for studying gas flow mechanisms. The presented microscopic effusion-based gas sensing methodology provides a nanomechanical alternative for large-scale mass-spectrometry and optical spectrometry based gas characterisation methods.

Atomically thin porous graphene is promising for filtration and sieving applications. Here the authors, using a laser-actuated micro-drum device of bilayer graphene with controlled number of nanopores, and measuring the permeation rate of different gases, show that it can also be used for permeation-based sensing.

Triggers of stress cardiomyopathy and their association with clinical outcomes

Background

Stress cardiomyopathy can be a result of physical stress, emotional stress, or both. Whether the type of trigger affects clinical outcomes is not well studied.

Purpose

The objectives of this study were to identify the prevalence of emotional and physical stressors and to assess differences in patient characteristics and mortality based on the type of trigger.

Methods

We conducted a retrospective review of 523 consecutive patients who presented to our institution from 2006 to 2016. All patients presented with acute coronary syndrome. Triggers for stress cardiomyopathy were abstracted from reviewing patients' medical records. Patients were categorized into those with 1) physical trigger, 2) emotional trigger, 3) both physical and emotional trigger, or 4) no known trigger. Baseline characteristics and clinical outcomes were reported.

Results

Among 523 patients with stress cardiomyopathy, 151 (28.9%) had a physical trigger, 189 (36.1%) had an emotional trigger, 30 (5.7%) had both physical and emotional triggers, and 153 (29.3%) had no known triggers identified. Men comprised the higher proportion of patients with physical triggers. Comorbidities including diabetes, pulmonary disease, chronic kidney disease and hypothyroidism were more prevalent among patients with physical triggers. Compared to patients with no obvious triggers, patients with a physical trigger had a much higher mortality rate (hazard ratio 2.0, 95% CI 1.2–3.3, p=0.007), whereas patients with an emotional trigger had significantly lower mortality (hazard ratio 0.40, 95% CI 0.21–0.89, p=0.007).

Conclusion

Different triggers for stress cardiomyopathy is associated with different baseline characteristics and clinical outcomes. Overall survival is worst in the group with an identified physical trigger.

Figure 1

Funding Acknowledgement

Type of funding source: None