Gastric bypass surgery contributing to hyperammonaemic encephalopathy: an under-reported cause of severe nutritional deficiency and significant patient mortality

Gastric-bypass associated hyperammonaemia (GaBHA) is an under-recognised cause of non-hepatic encephalopathy that is associated with significant mortality and has limited reporting in published literature. GaBHA has been reported predominately in middle-aged females with a past surgical history of Roux-En-Y surgical procedure. Individuals may present at any stage post-surgery and an important minority may have an undiagnosed inherited metabolic disorder. We report a case of a 49 year old woman who presented acutely with encephalopathy, a significantly elevated plasma ammonia level, and substantial multifactorial nutritional deficiency which required correction with intensive enteral and parenteral nutritional support. This case represented a diagnostic and management challenge for acute medical physicians and the multidisciplinary team involved.

Regulation of STAT3 signaling in IFNγ and IL10 pathways and in their cross-talk

The pro-inflammatory IFNγ-STAT1 pathway and anti-inflammatory IL10-STAT3 pathway elicit cellular responses primarily utilizing their canonical STATs. However IL10 mediated STAT1 and IFNγ mediated STAT3 activation is also observed, suggesting crosstalk of these functionally opposing signaling pathways can potentially reshape the canonical dynamics both STATs and alter the expression of their target genes. Herein, we measured the dynamics of STATs in response to different doses of IL10 or IFNγ and in their co-stimulation and employed quantitative modeling to understand the regulatory mechanisms controlling signal responses in individual and co-simulation scenarios. Our experiments show, STAT3 in particular, exhibits a bell-shaped dose-response while treated with IFNγ or IL10 and our model quantiatively captured the dose-dependent dynamics of both the STATs in both pathways. The model next predicted and subsequent experiments validated that STAT3 dynamics would robustly remain IL10 specific when subjected to a co-stimulation of both IFNγ and IL10. Genes common to both pathways also exhibited IL10 specific expression during the co-stimulation. The findings thus uncover anovel feature of the IL10-STAT3 signaling axis during pathway crosstalk. Finally, parameter sampling coupled to information theory based analysis showed that bell-shaped signal-response of STAT3 in both pathways is primarily dependent on receptor concentration whereas robustness of IL10-STAT3 signaling axis in co-stimulation results from the negative regulation of the IFNγ pathway.

Data-driven operation of the resilient electric grid: A case of COVID-19

Electrical energy is a vital part of modern life, and expectations for grid resilience to allow a continuous and reliable energy supply has tremendously increased even during adverse events (e.g. Ukraine cyberattack, Hurricane Maria). The global pandemic COVID-19 has raised the electric energy reliability risk due to potential workforce disruptions, supply chain interruptions, and increased possible cybersecurity threats. Additionally, the pandemic introduces a significant degree of uncertainty to the grid operation in the presence of other challenges including aging power grids, high proliferation of distributed generation, market mechanism, and active distribution network. This situation increases the need for measures for the resiliency of power grids to mitigate the impact of the pandemic as well as simultaneous extreme events including cyberattacks and adverse weather events. Solutions to manage such an adverse scenario will be multi-fold: (a) emergency planning and organisational support, (b) following safety protocol, (c) utilising enhanced automation and sensing for situational awareness, and (d) integration of advanced technologies and data points for ML-driven enhanced decision support. Enhanced digitalisation and automation resulted in better network visibility at various levels, including generation, transmission, and distribution. These data or information can be employed to take advantage of advanced machine learning techniques for automation and increased power grid resilience. In this paper, the resilience of power grids in the face of pandemics is explored and various machine learning tools that can be helpful to augment human operators are discused by: (a) reviewing the impact of COVID-19 on power grid operations and actions taken by operators/organisations to minimise the impact of COVID-19, and (b) presenting recently developed tools and concepts of machine learning and artificial intelligence that can be applied to increase the resiliency of power systems in normal and extreme scenarios such as the COVID-19 pandemic.

318 Adapting Surgical Intercalation Teaching to The Pandemic – A Novel Near-Peer Educational Model for Intercalating Medical Students

Aim

The COVID-19 pandemic has reduced medical student exposure to traditional formats of surgical teaching, thereby irrefutably altering surgical education for the foreseeable future. The pandemic has compounded the preliminarily reported disconnect intercalating students experience, as well as depriving students of opportunities for surgical exposure. The aim of our study is to devise an innovative near-peer system to supplement surgical teaching and guidance for the ‘Surgical Sciences’ Intercalated BSc offered at University College London, hence promoting surgical education.

Method

Past students (preceding two cohorts) were competitively recruited, termed mentors. Each student was paired with a mentor for one-to-one guidance. Mentors and programme directors formulated surgical, module-specific, virtual tutorials (Zoom). Mentees were surveyed using predesigned Google Forms to gauge subjective utility. Likert Scales (0-10) were used for quantitative analysis and free-text fields for further commentary.

Results

Mentors and programme directors devised 8 module-specific, surgical tutorials over term 1, spaced on average at every 1.5 weeks. A statistically significant increase in confidence reported per taught module, from 5.85±1.16 to 7.85±0.93 (P < 0.0001), was observed. Mentees report an overall recommendation of 93.19% that all tutorials be rerun for the upcoming cohort. 75% of mentees predict their designated mentors will be ‘very useful’ in their surgical education.

Conclusions

A novel model of near-peer education for surgical intercalation studies has been successfully established, whereby students receive valuable education and guidance from mentors with relevant surgical experiences. Students report significant utility in this programme, which can be a constant in otherwise turbulent times for surgical education.

980 Technological Innovations in The Management of Pressure Ulcers: A Systematic Review and Discussion

Aim

Pressure ulcers (PUs) affect over 700,000 patients per annum and are associated with an up to fourfold increase in mortality rate in older populations with complex pathologies. NICE guidelines for PU management involve a combination of low-grade technological interventions, including dressings and foam mattresses, while technology-centric therapies are not offered. The aim of this systematic review is to evaluate the effectiveness of any novel and high-grade technological PU interventions.

Method

The PubMed, Embase (via Ovid), Web of Science and CINAHL databases were electronically searched using free-text and MeSH search strings. Results evaluating the type of technological intervention, outcome measures and wound healing rates, duration of hospital stay, requirement for surgical debridement, infection and mortality rates were methodically assessed.

Results

An initial search identified 900 articles. Using the PRISMA guidance, 25 studies were included, encompassing 845 patients. 28 novel modalities of high-grade innovations were identified, with distinguished technologies including smart wireless bandages and 3D-printed wound repair scaffolds. Overall, 92.8% of devices demonstrated an improvement in wound healing (P < 0.05). A novel framework was created from the different innovations identified to approach adopting innovation in PU management.

Conclusions

The majority of high-technology innovations identified in this systematic review significantly improve PU healing, thus offering an additional pathway to standard care. Given the annual cost of PUs (£531 million), it is vital innovative technologies are considered as the NHS transitions into a digital age. Therefore, further studies are essential and recommended to evaluate the potential benefit of the promising, innovative technologies identified.

851 Giant Oncocytoma In A Solitary Kidney: A Case Report on Balancing Surgical Resection Against Surveillance

Renal oncocytomas are benign kidney neoplasms that are typically small, unilaterally localised (95%) and challenging to differentiate on cross-sectional imaging, hence requiring surgical intervention. We herein present the extremely rare case of a patient with giant, bilateral oncocytomas and oncocytosis, and chronic kidney disease (CKD) and discuss the associated treatment challenges.

A 61-year-old male with no past medical history presented with CKD (eGFR of 32ml/min). On investigation, cross sectional imaging revealed bilateral, multifocal, solid and vascular renal lesions. The largest lesion measuring 115mm x 102mm was situated in the right kidney, with multiple lesions noted in the left kidney, measuring up to 44mm. He subsequently underwent a right radical nephrectomy and histopathological analysis reported oncocytosis of the background kidney. The largest left sided renal lesion was biopsied, also confirmatory of benign oncocytoma. eGFR after surgery was 26ml/min. Following patient-centric consultations, further surgical intervention for the left sided renal lesions was declined, aiming to avoid renal replacement therapy (RRT). He has remained on active surveillance with biannual scans for 6 years. The lesions in his remaining kidney have since grown and coalesced into a single large lesion, with axial dimensions in the most recent MRI scan of 104mm x 306mm. He has progressed to stage IV CKD (eGFR 16ml/min), but still currently without need of RRT.

This case study underscores both the significance of shared decision making in urology and surgery. Ultimately, the most significant skill lies in knowing when to not operate, especially when presented with the rarest of cases.

119 The Potential of Low-fidelity Arthroscopic Simulation Training in Trauma and Orthopaedic Surgery: A Systematic Review of Experimental Studies

Aim

In an era of budget tightening and work-hour guideline reductions that have significantly reduced surgical exposure, low-fidelity arthroscopic simulators have an essential role to play in surgical training. The COVID-19 pandemic has only further amplified the need for alternative training models, as 91% of orthopaedic trainees have had elective procedures cancelled. The purpose of this systematic review is to synopsise the limited literature regarding the effectiveness of low-fidelity training models in the instruction of novices, and to formulate recommendations for future studies.

Method

The Embase, PubMed, Web of Science and Scopus databases were electronically searched. Studies from any year that described the use of orthopaedic, low-fidelity arthroscopic training models in novice populations were included. Questionnaires, case studies and review studies were excluded. Risk of bias assessments were also conducted for all studies.

Results

16 studies were identified. Using the PRISMA algorithm, 6 studies were deemed relevant. A cross-study comparison revealed low-fidelity arthroscopic simulators reduced time to completion outcomes (P < 0.05), increased ASSET scores (P < 0.01) and confirmed face validity and transfer of skills (cadaver, live patients).

Conclusions

Low-fidelity simulator training significantly improves the arthroscopic performance of novices, without the high setup costs and practical constraints of high-fidelity equivalents. Low-fidelity arthroscopic simulators remain a promising training apparatus in an era of reduced surgical exposure (COVID-19). We have identified the need for consistent outcome measures with greater sample sizes across future studies. We recommend the use of standardised pre-intervention teaching (e.g., ABOS curriculum) and further transference, construct, and face validity evaluations to support future result interpretations.

1376 Latex Allergies: Seeking an Alternative to Minimise Risk in The Operating Theatre

Introduction

Natural Rubber Latex (NRL) gloves have been ubiquitously used in surgical practice. Over the past few decades, there have been many reports of NRL allergies associated with their use presenting a safety hazard to both patients and healthcare workers. Powder-free and latex-free gloves have been shown to offer reductions in incidence of allergic reactions, as well as cost savings.

Method

We performed a literature search to identify the rates of reaction to latex across the population in addition to the associated costs including litigation costs, costs of admission, and lost work time associated. We further looked at the rates of perforation of alternatives and the costs associated with such a transition.

Results

The UK prevalence of sensitisation amongst healthcare workers has been estimated to be 10%. The average cost of litigation to the employer was found to be $21,402 per claim. The mean cost of inpatient care for anaphylaxis has been cited as £469.88, with additional costs such as follow-up representing approximately £400. A 14-month study found cost savings of $10,000pa with a switch to non-latex gloves. Furthermore, an overall perforation rate of 80% in a latex-free glove compared to 34.4% in a latex glove.

Conclusions

From a business perspective, there is evidence of cost-savings arising from a switch to latex-free gloves, however, formal cost-effectiveness analyses would inform future decisions. Furthermore, comfort and reducing the chances of allergic reactions through removing the offending allergen all represent benefits of switching to latex-free gloves, however, non-inferiority analyses will inform future strategies both locally and nationally.

1070 A Systematic Review of Seymour Fracture Management

Aim

Seymour fractures are distal phalanx fractures of the finger in children with a juxta-epiphyseal or Salter-Harris Type I/II pattern associated with a nail-bed injury. There remains a paucity in literature regarding the development of complications between Seymour fracture management options, with early studies encouraging non-operative management due to the increased rates of post-operative infection. This systematic review aims to identify present-day, optimal management strategies for Seymour fractures, with further analysis of infection rates and secondary outcomes during post-operative recovery.

Method

Free-text search, MeSH terms and expanded keywords/phrases were employed to search the PubMed, Embase (via Ovid), Web of Science and CINAHL databases. Studies that described the management of Seymour fractures in paediatric patients were included, subject to inclusion/exclusion criteria. The data extracted included the sample size, intervention, infection rates and secondary outcomes.

Results

An initial search identified 305 articles, following the PRISMA guidance, 8 studies were eligible for full-text analysis. Across all studies, 307 Seymour fractures were identified (mean age, 10±1.2 years). A cross-study analysis showed a lower rate of adverse outcomes (including malunion/non-union and unplanned operative intervention) for K-wire fixation when compared to external splinting, 8.3% and 20.7% (P ≤ 0.001), respectively.

Conclusions

There was no statistically significant difference between non-operative and operative management in rates of infection and adverse outcomes. However, further analysis revealed a significantly lower risk of complications in patients who received K-wire fixation when compared to external splinting. Nonetheless, further studies with greater levels of evidence need to be carried out to consolidate this.

A pre-registered short-term forecasting study of COVID-19 in Germany and Poland during the second wave

Disease modelling has had considerable policy impact during the ongoing COVID-19 pandemic, and it is increasingly acknowledged that combining multiple models can improve the reliability of outputs. Here we report insights from ten weeks of collaborative short-term forecasting of COVID-19 in Germany and Poland (12 October-19 December 2020). The study period covers the onset of the second wave in both countries, with tightening non-pharmaceutical interventions (NPIs) and subsequently a decay (Poland) or plateau and renewed increase (Germany) in reported cases. Thirteen independent teams provided probabilistic real-time forecasts of COVID-19 cases and deaths. These were reported for lead times of one to four weeks, with evaluation focused on one- and two-week horizons, which are less affected by changing NPIs. Heterogeneity between forecasts was considerable both in terms of point predictions and forecast spread. Ensemble forecasts showed good relative performance, in particular in terms of coverage, but did not clearly dominate single-model predictions. The study was preregistered and will be followed up in future phases of the pandemic.

Limited utility of plasma elafin as a biomarker for skin graft-versus-host disease following allogeneic stem cell transplantation

BACKGROUND

Acute cutaneous graft-versus-host disease (acGVHD) following haematopoietic stem cell transplant (HSCT) is common but difficult to distinguish from other causes of rash. Plasma elafin has been proposed as a diagnostic and prognostic biomarker of skin GVHD.

AIM

To evaluate the role of plasma elafin as a biomarker in acGVHD in an Indian population.

METHODS

Plasma elafin was evaluated in a prospective study of HSCT recipients, conducted over 2 years, taking measurements at baseline and at onset of skin rash after HSCT. Patients were categorized into those with GVHD rash, those with non-GVHD rash and those with no rash and the three groups were compared.

RESULTS

Two hundred and sixty-one patients with a median age of 16 years (range 1-61 years) and a male predominance (175 : 86 M/F) underwent HSCT during the study period: 56 patients in the GVHD group, 49 in the non-GVHD group and 156 in the no-rash group. The median baseline elafin was similar in all three groups. At the onset of rash, median elafin level was similar between GVHD and non-GVHD rash (34 549 vs. 32 077 pg/mL; P = 0.58) and between GVHD and no rash (34 549 vs. 26 197 pg/mL; P = 0.08). A rise in elafin from baseline was significantly different between GVHD and no rash (P < 0.001) but not between GVHD and non-GVHD rash (P = 0.44).

CONCLUSION

The utility of plasma elafin as a biomarker of skin GVHD is very limited. Plasma elafin, although elevated in cutaneous GVHD, is not helpful in distinguishing between GVHD rash and other causes of rash following HSCT.

Tripathi U. Synthesis, spectral and sol-gel behavior of mixed ligand complexes of titanium(IV) with oxygen, nitrogen and sulfur donor ligands

A new route to synthesize nano-sized Ti(IV) mixed ligand complexes have been investigated by the reaction of titanium(IV) chloride with ammonium salts of dithiophosphate and 3(2'-hydroxyphenyl)-5-(4-substituted phenyl) pyrazolines. The resultant complex is then treated with H2S gas to get sulfur bridged dimer of Ti(IV) complex, a precursor of TiS2. The morphology of the complexes was studied by employing XRD which shows that all the complexes are amorphous solid. Molecular weight measurements, elemental analysis in conjugation with spectroscopic (IR, 1H NMR, 13C NMR and 31P NMR) studies revealed the dimeric nature of the complexes in which pyrazoline and dithiophosphate are bidentate. Scanning electron microscopic image and XRD indicate that the particles are in the nano range (50 nm). Putting all the facts together, coordination number six is proposed for titanium with octahedral geometry.                     KEY WORDS: Titanium(IV), Dithiophosphate, Pyrazoline, Nano-sized, Sol-gel, Mixed ligand complexes   Bull. Chem. Soc. Ethiop. 2021, 35(1), 61-76. DOI: https://dx.doi.org/10.4314/bcse.v35i1.5

203 Developing and Fine-Tuning Novel 3D-Printed Biodegradable Scaffolds to Promote Auricular Cartilaginous Regeneration for Surgical Implantation

Introduction

Microtia, a congenital cartilaginous defect, poses major challenges in cosmetic surgery. Biodegradable polymers promote chondrogenesis, with promises of seeding cells into synthetic-polymer-implants for surgical fixation. However, existing polymers used in auricular reconstruction present limitations including inflammation, fibrosis, and extrusion. This study aimed to modulate the mechanical properties of the novel polylactic-acid/polyhydroxyalkanoate (PLA/PHA) blend by 3D-printing and hence, evaluate its suitability to the auricular microenvironment in developing next-generation reconstructs.

Method

Digitally defined PLA/PHA scaffolds were free-form 3D-printed at various infill densities and thicknesses. Through tensile testing, tensile moduli, yield point, maximum strength, tensile toughness, and stiffness were calculated, alongside Finite Element Analysis (FEA) and contact angle tests. Finally, preliminary cell seeding was conducted.

Results

Increasing infill densities of PLA/PHA scaffolds from 30%-60% significantly increased tensile moduli, yield point and maximum strength (P &lt; 0.01). Tensile stiffness increased significantly with scaffold thicknesses between 1mm-2mm (P &lt; 0.05). Cell studies showed promising proliferative activity.

Conclusions

The mechanical properties and structural stiffness of 3D-printed PLA/PHA scaffolds can be significantly tailored by altering infill density and thickness, respectively. The digitally defined interconnected pores within printed PLA/PHA scaffolds reduce stiffness mismatches between surgical-synthetic polymers and auricular cartilage, potentially promoting cell migration and nutrition transportation in future reconstructs.

Copy number and transcriptome alterations associated with metastatic lesion response to treatment in colorectal cancer

BACKGROUND

Therapeutic resistance is the main cause of death in metastatic colorectal cancer. To investigate genomic plasticity, most specifically of metastatic lesions, associated with response to first-line systemic therapy, we collected longitudinal liver metastatic samples and characterized the copy number aberration (CNA) landscape and its effect on the transcriptome.

METHODS

Liver metastatic biopsies were collected prior to treatment (pre, n = 97) and when clinical imaging demonstrated therapeutic resistance (post, n = 43). CNAs were inferred from whole exome sequencing and were correlated with both the status of the lesion and overall patient progression-free survival (PFS). We used RNA sequencing data from the same sample set to validate aberrations as well as independent datasets to prioritize candidate genes.

RESULTS

We identified a significantly increased frequency gain of a unique CN, in liver metastatic lesions after first-line treatment, on chr18p11.32 harboring 10 genes, including TYMS, which has not been reported in primary tumors (GISTIC method and test of equal proportions, FDR-adjusted p = 0.0023). CNA lesion profiles exhibiting different treatment responses were compared and we detected focal genomic divergences in post-treatment resistant lesions but not in responder lesions (two-tailed Fisher's Exact test, unadjusted p ≤ 0.005). The importance of examining metastatic lesions is highlighted by the fact that 15 out of 18 independently validated CNA regions found to be associated with PFS in this study were only identified in the metastatic lesions and not in the primary tumors.

CONCLUSION

This investigation of genomic-phenotype associations in a large colorectal cancer liver metastases cohort identified novel molecular features associated with treatment response, supporting the clinical importance of collecting metastatic samples in a defined clinical setting.