Impacts of Groundwater Pumping for Hydraulic Fracturing on Aquifers Overlying the Eagle Ford Shale

Hydraulic fracturing (HF) events consume high volumes of water over a short time. When groundwater is the source, the additional pumping by rig/frack supply wells (RFSWs) may impose costs on owners of other sector wells (OSWs) by lowering the hydraulic head. The Carrizo-Wilcox aquifer in south Texas is the main source of water for HF of the Eagle Ford Shale (EFS) Play. The objectives are to assess the impacts of groundwater pumping for HF supply on: (1) hydraulic heads in OSWs located nearby an RFSW and (2) volumetric fluxes between layers of the regional aquifer system compared to a baseline model without the effect of RFSW pumping. The study area spans the footprint of the EFS Play in Texas and extends from 2011 to 2020. The pumping schedules of 2500 RFSWs were estimated from reported pumped water volumes to supply 22,500 HF events. Median annual drawdowns in OSWs ranged from 0.2 to 6.6 m, whereas 95th percentile annual drawdowns exceeded 20 m. The magnitudes of drawdown increased from 2011 to 2020. Of the four layers that comprise the Carrizo-Wilcox aquifer, the upper Wilcox was the most intensively pumped for HF supply. During the peak HF year of 2014, the net flux to the upper Wilcox was 292 Mm3 compared to the baseline net flux for the same year of 278 Mm3-a relative gain of 14 Mm3. Pumping for HF supply has the potential to negatively impact nearby OSWs by capturing water from adjacent aquifer layers.

How to do laparoscopic repair of perforated anterior duodenal ulcers: a 'three arches' falciform patch technique simplifies the approach

Laparoscopic repair of perforated duodenal ulcers has proven superior results to open procedures though uptake has been poor. We describe the 'three arches' technique as a means of reducing technical difficulty and improving operative efficiency. Our case series of patients undergoing this technique for perforated peptic ulcer disease demonstrates comparable results to other methods of repair.

A150 MODERATE AGREEMENT IN ENDOSCOPIC DISEASE SCORING OF PEDIATRIC EOSINOPHILIC ESOPHAGITIS AMONG PEDIATRIC GASTROENTEROLOGISTS IN CANADA

Background

Endoscopy is an important tool in assessing the severity of gastrointestinal diseases including Eosinophilic Esophagitis (EoE). Agreement regarding endoscopy outcomes is important when using tools such as the Endoscopic Reference Score for EoE (EREFS).

Purpose

Our goal was to determine interrater and intrarater agreement of EREFS among Canadian pediatric gastroenterologists.

Method

Survey-based study of interrater and intrarater reliability amongst pediatric gastroenterologists with interest in pediatric EoE. Participants were sourced from the Canadian Pediatric EoE Network. Participants were asked how many years of training they’ve had with endoscopy for pediatric EoE and their comfort in disease scoring for pediatric EoE. Pediatric EoE cases were identified from the pediatric EoE registry at the Stollery Children’s Hospital with an endoscopic video associated with each case. Participants were asked to score each video using the EREFS questionnaire for the proximal, middle and distal segments of the esophagus. 15 endoscopic videos were evaluated, with 3 cases provided each week over a period of 5 weeks. Additional data included ratings of the video quality and endoscopy quality. Of 15 cases, 12 were unique cases, distributed evenly in severity between no active disease to severe disease. 3 cases were repeated to assess intrarater reliability. The maximum grade of the proximal, middle and distal segments of the esophagus for each component endoscopic finding (edema, rings, exudates, furrows, strictures) were used for reliability calculations. Fleiss Kappa was calculated for all EREFS items and for each component endoscopic finding. Cohen’s Kappa was calculated to assess intrarater reliability.

Result(s)

Fifteen participants were recruited for the study. The participants had a median of 12 years (IQR: 7, 19) of clinical experience in endoscopy for pediatric EoE. The majority of participants were “comfortable” (i.e., 4 on 5-point scale) with EREFS scoring for pediatric EoE. Fleiss Kappa for all EREFS items was 0.481. For each component endoscopic finding (edema, rings, exudates, furrows, strictures), Fleiss Kappa was 0.365, 0.293, 0.548, 0.263, 0.445 respectively. Cohen’s Kappa had a median of 0.620 (IQR: 0.593, 0.704). The majority of raters rated video quality and endoscopy quality as “good” (i.e., 4 on 5-point scale).

Conclusion(s)

There is moderate interrater reliability in EREFS scoring for pediatric EoE. Interrater reliability was between fair to moderate for each component endoscopic finding. Intrarater reliability was good. This study shows there is room for improvement in disease scoring for pediatric EoE. This could be in the form of additional training, expert-defined conventions, or centralized reading which have reduced variability in endoscopic reporting for adult GI disease in past studies and could be used in a follow-up study to attempt to improve agreement. Additionally, incorporating EREFS into routine clinical practice may increase agreement amongst endoscopists.

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None

Disclosure of Interest

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A143 PEDIATRIC EOSINOPHILIC ESOPHAGITIS IN CANADA: A MULTI-CENTER COHORT WITH FOCUS ON THE STRICTURING PHENOTYPE

Background

Eosinophilic esophagitis (EoE) is a chronic eosinophil-predominant esophageal inflammatory condition, and is now recognized as one of the most common organic causes of dysphagia in pediatrics. While fibrostenotic esophageal strictures are a common complication of adult EoE, characterization of the stricturing phenotype in pediatric EoE remains at an early stage.

Purpose

Describe the Canadian pediatric EoE experience, with focus on the stricturing phenotype.

Method

New pediatric EoE diagnoses from 2015-2018 were retrospectively identified in Vancouver (BC), Northern Alberta (AB), Hamilton (ON) and Nova Scotia (NS). Incidence rates were calculated using 2016 Federal census data. Clinical, endoscopic and histologic data were gathered for each patient’s initial clinical encounter and for any esophagogastroduodenoscopies (EGD) until the end of the follow-up period (fall 2019).

Result(s)

332 new EoE cases were identified during the study period across all 4 sites. The incidence of EoE in patients less than 15 years old was 9.1 (AB), 6.5 (NS), 3.1 (BC) and 5.4 (combined) per 100,000 person-years. Incidence was not calculated for Hamilton due to risk of ascertainment bias given their catchment area overlaps with multiple other centers. Of identified cases, 40 (12.0%) had endoscopically-identified esophageal strictures at diagnosis or during the follow-up period, with a subset of 11 (3.3%) of these patients undergoing mechanical esophageal dilation. Another 11 (3.3%) patients had more subtle signs of esophageal narrowing (ex. mucosal rents), while the majority had no evidence of esophageal narrowing (281, 84.6%). The median age at diagnosis was higher in the cohort with strictures (12.4 years, IQR 8.9-14.1) than those without (10.3 years, IQR 6.1-13.6) but with wide IQR's. A similar trend was seen for the median duration of symptoms at diagnosis (1.5 years, IQR 0.5-3 versus 1.0 years, IQR 0.6-2.8). Patient reported food bolus impaction (OR 9.8, 95% CI 3.9-19.9) and dysphagia (OR 3.3, 95% CI 1.3-7.8) were associated with stricturing disease, with other symptoms less clearly linked. Trachealization was the endoscopic finding most closely associated with esophageal strictures (OR 5.7, 95% CI 2.8-11.5). Esophageal stricture(s) were noted on 72 EGDs, including 27 endoscopic esophageal dilations, but excluding 10 esophageal dilations by interventional radiology. Of the 65 EGDs done in follow-up of a known esophageal stricture (see Table), 4 of 31 had resolution of this finding post mechanical dilation, and 19 of 39 had resolution of the stricture after initiation of new medical or dietary treatments (without dilation).

Conclusion(s)

EoE is common in Canadian children, with esophageal strictures within a few years of diagnosis in 12% of cases. Interestingly, a large portion of strictures resolved without mechanical dilation, which seems to point away from fibrosis as the primary driver of esophageal strictures in this patient population.

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CAG, Other

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Women and Children's Health Research Institute

Disclosure of Interest

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Prospective multicentre randomised controlled trial of the effect of raun Enteroenterostomy in the Reconstruction after Pancreaticoduodenectomy on delayed gastric emptying (DGE): protocol for the BERP study

INTRODUCTION

Despite advances in achieving low mortality rates with pancreaticoduodenectomy (PD), morbidity remains high. A key contributor to this morbidity is delayed gastric emptying (DGE) occurring with an incidence of up to 30%. The utility of a Braun enteroenterostomy (BE) appears promising to reducing the incidence of DGE, but current research is not definitive.

METHODS AND ANALYSIS

This project will be designed as a prospective multicentre randomised controlled blinded study to assess how BE effects the rate of DGE after PD in the setting of malignancy, within Australia-with blinding of patients, outcome assessors and data analysts. Patients will be randomly assigned to PD with Billroth II reconstruction with BE versus PD with Billroth II reconstruction without BE. The primary outcome is the incidence of DGE as defined by the International Study Group of Pancreatic Surgery. Secondary outcomes will include length of hospital stay, postoperative pancreatic fistula incidence, development of major complications (Clavien-Dindo≥3 a), quality of life and 90-day mortality.The study will be powered at 80% to detect a reduction in DGE rate from 30% to 15%, requiring a total of 264 study participants. An interim analysis will be performed once a total of 104 study participants have been recruited at which point the study will be able to detect reduction in DGE from 30% to 10% with 80% power. Statistical analysis will be done with intention-to-treat principles. The proportion of patients suffering DGE will be compared between treatment arms using a χ² test, with p values used to represent statistical significance.

ETHICS AND DISSEMINATION

The study has been ethically approved by the Hunter New England Human Research Ethics Committee (2021/ETH11939), with results disseminated through presentation and publication.

TRIAL REGISTRATION NUMBER

CTRN12622000048785.

Reclaimed and Up-Cycled Cathodes for Lithium-Ion Batteries

As electric vehicles become more widely used, there is a higher demand for lithium-ion batteries (LIBs) and hence a greater incentive to find better ways to recycle these at their end-of-life (EOL). This work focuses on the process of reclamation and re-use of cathode material from LIBs. Black mass containing mixed LiMn₂O₄ and Ni_0.8Co_0.15Al_0.05O₂ from a Nissan Leaf pouch cell are recovered via two different recycling routes, shredding or disassembly. The waste material stream purity is compared for both processes, less aluminium and copper impurities are present in the disassembled waste stream. The reclaimed black mass is further treated to reclaim the transition metals in a salt solution, Ni, Mn, Co ratios are adjusted in order to synthesize an upcycled cathode, LiNi_0.6Mn_0.2Co_0.2O₂ via a co-precipitation method. The two reclamation processes (disassembly and shredding) are evaluated based on the purity of the reclaimed material, the performance of the remanufactured cell, and the energy required for the complete process. The electrochemical performance of recycled material is comparable to that of as-manufactured cathode material, indicating no detrimental effect of purified recycled transition metal content. This research represents an important step toward scalable approaches to the recycling of EOL cathode material in LIBs.

Pharmacological prevention of post-operative pancreatitis: systematic review and meta-analysis of randomized controlled trials on animal studies

BACKGROUND

Postoperative pancreatic fistula (POPF) remains a significant complication of pancreatic resection with recent evidence showing a strong association between post-operative pancreatitis and subsequent development of POPF. Incidence and severity of pancreatitis following endoscopic therapy has been effectively reduced with indomethacin prophylaxis, however further agents require evaluation. We present a systematic literature review and meta-analysis of the prophylactic treatment with corticosteroids or n-acetyl cysteine (NAC) of induced pancreatitis in rodent models.

METHODS

A systematic literature search was conducted using Pubmed, Medline, Embase and Cochrane library to identify eligible randomized control trials (RCT) involving animal models that examined NAC or corticosteroids. The primary outcome was the subsequent effect on serum amylase and IL-6 and the histopathological markers of severity such as pancreatic oedema and necrosis.

RESULTS

Four RCTs (n = 178) met inclusion criteria examining NAC and eight RCTs (n = 546) examining corticosteroid agents (dexamethasone, hydrocortisone, methylprednisolone). Prophylactic administration of all corticosteroid agents showed a net effect in favour of reducing markers of severity of pancreatitis. NAC showed a significant reduction in severity of amylase and necrosis.

CONCLUSION

The RCTs examined suggest that prophylactic administration of corticosteroid agents and NAC can reduce the severity of pancreatitis as indicated by histopathologic markers, serum amylase and IL-6 levels.

Incidence of Pediatric Eosinophilic Esophagitis and Characterization of the Stricturing Phenotype in Alberta, Canada

Limited work has been done to characterize the stricturing pediatric eosinophilic esophagitis (EoE) phenotype. We aimed to determine, in pediatric EoE: the local incidence, the frequency of esophageal stricturing, and the safety of mechanical dilations.

Methods

We retrospectively identified all new cases of EoE at our center from 2015 to 2018 using esophageal biopsy reports, EoE clinic lists, and a local OR database of esophageal dilatations. Electronic medical records (EMRs) were reviewed to confirm EoE diagnosis. Clinical data were captured from the outpatient EMR and gastroscopy/pathology reports. Scope adverse event data were captured from multiple sources. The 2016 census data were used to calculate incidence rates.

Results

One hundred eighty-five new cases of EoE were diagnosed during the study period. For patients <15 years old living in Edmonton, the incidence over the 4 years was 11.1 cases per 100,000 person years. Eight of 185 (4%) patients had endoscopically confirmed esophageal strictures, 4 of which required mechanical dilation. Eleven of 185 (5.9%) patients had more subtle signs of esophageal narrowing, but no focal strictures. No perforations or episodes of significant bleeding were reported. Pain was reported after 15% of all scopes, including 50% of the 28 scopes with focal strictures. No unexpected admissions or emergency department visits occurred within 72 hours of a gastroscope with esophageal narrowing.

Conclusions

Edmonton zone has one of the highest incidences of pediatric EoE reported. In this cohort, 4% had focal esophageal strictures, and 6% had more subtle narrowing. Mechanical dilation of esophageal strictures was associated with no significant adverse events.

A14 WIDE VARIATION IN CLINICAL MANAGEMENT OF PAEDIATRIC EOSINOPHILIC ESOPHAGITIS: A CANADIAN EXPERIENCE

Background

Eosinophilic esophagitis (EoE) is a chronic disorder treated by food elimination diet (FED), topical steroids and/or proton-pump inhibitors (PPI). Serial endoscopies and biopsies assess response to therapy. EoE management has evolved as guidelines are updated.

Aims

To identify practice variation among Canadian paediatric gastroenterologists (PG) who care for children with EoE.

Methods

An online survey using REDCap about decision-making in children with EoE was distributed to PG in Canada in November 2020.

Results

62 PG completed the survey (response rate 69%, 62/94). The majority work in academic centres (92%). 3 centers indicated an accrual of &gt;50 new patients per year; 9/16 centres have &gt;100 patients in follow-up. An EoE Clinic is present in 5 centres.

Diagnosis: Familiarity with the 2018 AGREE and 2020 AGA EoE guidelines was found to be 57% and 67% respectively. Criteria required to diagnose EoE according to current guidelines were correctly indicated by 42% of PG. (Figure 1).

Endoscopy: The majority of PG (95%) adhere to guidelines in terms of required number and location of biopsies for the initial diagnosis. Ideal timing of repeat endoscopy after change in therapy in patients who are not in histological remission was 8–12 weeks by 67% of PG, timing in stable patients on maintenance therapy varied (33% only if patient is symptomatic). 25% used the EREFS Score in reporting endoscopic findings.

Therapy: Improvement of symptoms was the highest ranked goal (64%), followed by remission of histologic findings (30%). A treatment algorithm was in place in 4 centers. The majority routinely assess adherence to therapy (73%) and consult a dietitian for FED (77%). Most (87%) do not consult an allergist for initial management. Preferred choices of 1st-line therapy varied among PG (Figure 2). When FED was selected, 32% of PG started with 1 food, 32% started with 2 foods, most frequently excluding dairy, followed by wheat. 14 (26%) start with ≥6 FED. Prescription of budesonide slurry was consistent among PG with doses of 1 and 2 mg/day in children &lt;10 and &gt;10 years, respectively.

Conclusions

The is the first Canadian study to assess the variation in management of children with EoE by PG. Overall, PG demonstrated good adherence to the guidelines in terms of initial diagnosis, but differences in maintenance therapy choice and timing of endoscopies. The results highlight a need for standardized management algorithms to deliver uniform care to this growing group. Grounding these guidelines in evidence will warrant a significant investment in further paediatric EoE research.

Funding Agencies

None

Spontaneous fistulisation of the common bile duct after transection by gunshot

A 35-year-old man presented with a gunshot wound to his abdomen via his lower chest. Initial laparotomy did not identify any perforation or contamination. On day 3, a laparotomy under the hepatobiliary service discovered a gastric perforation, two lateral duodenal perforations and a complete transection of the common bile duct, presumably delayed perforation from the shockwave injury produced by the bullet. Contamination and haemodynamic instability precluded immediate reconstruction, and abdominal drains and external biliary drainage were established. High-volume duodenal fistula was managed with slow withdrawal of drains, and inadvertent dislodgement of the biliary drain in an outpatient setting resulted in spontaneous fistulisation of the bile duct to the lateral duodenal wall, with creation of a neo-bile duct. The patient remains well more than 1 year later, without external drainage despite no surgical reconstruction.

AMY1 Gene Copy Number Correlates With Glucose Absorption and Visceral Fat Volume, but Not with Insulin Resistance

BACKGROUND

The human amylase gene (AMY1) has a broad copy number (CN) variation that may associate with body mass index.

METHODS

Deoxyribonucleic acid was extracted from urine (n = 74) and serum (n = 6) samples (Protein, Fiber and Metabolic Syndrome [ProFiMet] cohort), and buccal (n = 17) samples (Oral Starch Challenge [OSC] cohort), and assessed for AMY1 CN by droplet digital polymerase chain reaction. The association of AMY1 CN with comprehensive markers of metabolic status (ProFiMet cohort) were analyzed with Pearson's correlation coefficient (CC). For the healthy, euglycemic OSC cohort, glycemic response to OSC was analyzed with independent sample t-tests (subgroups: high AMY1 CN 9-12, n = 10; low AMY1 CN 4-6, n = 7).

RESULTS

There were significant inverse correlations of AMY1 CN with total visceral fat volume (CC -0.33; P = 0.004) and positive correlations of AMY1 CN with oral glucose insulin sensitivity score (derived from an oral glucose tolerance test, CC 0.26; P = 0.02), serum HDL-cholesterol (CC 0.325; P = 0.003), and serum adiponectin (CC 0.249; P = 0.026). Linear regression multivariate analysis (adiponectin as dependent variable), showed independent association of adiponectin with AMY1 CN (Beta = 0.29; P = 0.03). There were no significant associations between AMY1 CN and clamp-derived M-value, homeostasis model assessment of insulin resistance (IR), hepatic endogenous glucose production, fecal floral signature, or macronutrient dietary preference. Delta (mean) change in blood glucose concentration (fasting to 30-minutes post-OSC) was significantly greater in the high versus low AMY1 CN subgroups (mean 1.7 mmol/l [SEM 0.6] vs 0.9 mmol/l [SEM 0.9], respectively; P = 0.016).

CONCLUSIONS

High AMY1 CN associates with a favorable metabolic profile (lower visceral fat volume, higher serum adiponectin, enhanced glucose absorption following oral glucose, and OSC), but not with whole-body or hepatic IR.

A196 INCIDENCE OF PEDIATRIC EOSINOPHILIC ESOPHAGITIS IN EDMONTON ZONE AND RISK OF STRICTURING AT DIAGNOSIS

Background

Eosinophilic esophagitis (EoE) is a common cause of esophageal dysfunction in children. A subset of children have a more severe phenotype of EoE, complicated by esophageal stricturing. Limited work has been done to characterize this phenotype.

Aims

To determine the incidence of EoE, and the frequency of esophageal stricturing in pediatric EoE.

Methods

We retrospectively identified all new cases of EoE at the Stollery Children’s Hospital from 2015–2018 using esophageal biopsy reports for the province of Alberta (CoPath database), EoE clinic lists and an OR database for esophageal dilatation at the Stollery. Electronic medical records (EMR) were reviewed to confirm EoE diagnosis. For each confirmed case, clinical data was captured from the outpatient EMR and gastroscopy/pathology reports. A review of peri-endoscopy OR/nursing charts was performed on a subset of patients (n=75) to capture scope adverse event. Statistics Canada 2016 census data was used to calculate incidence rates.

Results

185 new cases of EoE were diagnosed at our center during the study period (see table). For patients &lt; 15 years old living in Edmonton zone (n=73), the incidence over the 4 years was 11.1 cases per 100,000 person years {8.7 (0–4 year-old), 7.6 (5–9 year old), and 18.1 (10–14 year old)}. There was limited variation in incidence in the 4 years (9.1–12.1 per 100,000 person years). 8 of 185 (4%) patients had endoscopically confirmed esophageal strictures, 4 of which required mechanical dilation (mean 3.75 dilations per patient, range 1–6). 11/185 (5.9%) patients had more subtle signs of esophageal narrowing, but no strictures. No perforations or episodes of significant bleeding were reported in peri-endoscopy charts reviewed for 239 gastroscopes, including 16 dilations. Pain was reported after 15% of all scopes, including 50% of the 28 scopes with strictures and 63% of the 16 scopes involving dilations.

Conclusions

Edmonton zone has one of the highest incidences of EoE reported in children. In this cohort, 4% had esophageal stricture (half required dilatation) and 5.9% had more subtle narrowing. Patients with strictures were older, had more frequent food impaction and longer duration of symptoms (Table). This data will be included in an ongoing multicenter case-control study across Canada.

Funding Agencies

CAGWomen and Children’s Health Research Institute (Univ. Alberta)

RNA Imaging with RNase-Inactivated Csy4 in Plants and Filamentous Fungi

Subcellular localizations of RNAs can be imaged in vivo with genetically encoded reporters consisting of a sequence-specific RNA-binding protein (RBP) fused to a fluorescent protein. Several such reporter systems have been described based on RBPs that recognize RNA stem-loops. Here we describe RNA tagging for imaging with an inactive mutant of the bacterial endonuclease Csy4, which has a significantly higher affinity for its cognate stem-loop than alternative systems. This property allows for sensitive imaging with only few tandem copies of the target stem-loop inserted into the RNA of interest.

Human amylase gene copy number variation as a determinant of metabolic state

INTRODUCTION

Humans have multiple genes encoding amylase that are broadly divided into salivary (AMY1) and pancreatic (AMY2) genes. They exhibit some of the greatest copy numbers of any human gene, an expansion possibly driven by increased dietary starch intake. Within the population, amylase gene copy number is highly variable and there is evidence of an inverse association between AMY1 copy number and BMI.

AREAS COVERED

We examine the evidence for the link between AMY1 and BMI, its potential mechanisms, and the metabolic effects of salivary and pancreatic amylase, both in the gastrointestinal tract and the blood

EXPERT COMMENTARY

Salivary amylase may influence postprandial 'cephalic phase' insulin release, which improves glucose tolerance, while serum amylase may have insulin-sensitizing properties. This could explain the favorable metabolic status associated with higher AMY1 copy number. The association with BMI is harder to explain and is potentially mediated by increased flux of undigested starch into the ileum, with resultant effects on short-chain fatty acids (SCFAs), changes in gut microbiota and effects on appetite and energy expenditure in those with low copy number. Future research on the role of amylase as a determinant of metabolic health and BMI may lead to novel therapies to target obesity.

The Surgical Management of Pilonidal Disease is Uncertain Because of High Recurrence Rates

Background Pilonidal disease is a common condition with no consensus for the best management of chronic disease or current practice in Australia and New Zealand. Methods A survey was distributed among 190 colorectal and 592 general surgeons in Australia and New Zealand. Data was obtained regarding pilonidal surgery volume, procedures performed, non-operative management and recurrence rates. Three clinical scenarios were also presented. Results The response rate was 58% among colorectal surgeons, 18% among general surgeons. Nineteen percent of surgeons were high-volume (>23 operations per year), 47% low-volume (<12 operations per year). The commonest procedure was the Karydakis procedure (77%), with many others performed including rhomboid flaps (36%), Bascom cleft lift (13%), Z-plasty (7%), and gluteal rotation flaps (5%). Fifty-five percent of high-volume surgeons offered more than one operation while only 16% of low-volume surgeons did. Nineteen percent operated on all patients with pilonidal disease, 89% believing off-midline closure to be superior to midline. Disease extent was the main driver for non-operative management; patient factors such as cosmesis and time-off work being the least important. Sixty-four percent reported recurrence rates above 5%, and 37% recurrence rates >10%. Six percent reported no recurrences ever. Five percent reported recurrence rates over 20%, but 24% stated that over one-fifth of their practice consists of recurrent disease. Conclusions This study reports higher recurrence rates than in published series, suggesting many surgeons do not see their own recurrences, with current treatment not as successful as previously thought. Combined with the widespread variation in practice, optimal management of this disease remains unclear.

Activity Based Protein Profiling Leads to Identification of Novel Protein Targets for Nerve Agent VX

Organophosphorus (OP) nerve agents continue to be a threat at home and abroad during the war against terrorism. Human exposure to nerve agents such as VX results in a cascade of toxic effects relative to the exposure level including ocular miosis, excessive secretions, convulsions, seizures, and death. The primary mechanism behind these overt symptoms is the disruption of cholinergic pathways. While much is known about the primary toxicity mechanisms of nerve agents, there remains a paucity of information regarding impacts on other pathways and systemic effects. These are important for establishing a comprehensive understanding of the toxic mechanisms of OP nerve agents. To identify novel proteins that interact with VX, and that may give insight into these other mechanisms, we used activity-based protein profiling (ABPP) employing a novel VX-probe on lysates from rat heart, liver, kidney, diaphragm, and brain tissue. By making use of a biotin linked VX-probe, proteins covalently bound by the probe were isolated and enriched using streptavidin beads. The proteins were then digested, labeled with isobarically distinct tandem mass tag (TMT) labels, and analyzed by liquid chromatography tandem mass spectrometry (LC-MS/MS). Quantitative analysis identified 132 bound proteins, with many proteins found in multiple tissues. As with previously published ABPP OP work, monoacylglycerol lipase associated proteins and fatty acid amide hydrolase (FAAH) were shown to be targets of VX. In addition to these two and other predicted neurotransmitter-related proteins, a number of proteins involved with energy metabolism were identified. Four of these enzymes, mitochondrial isocitrate dehydrogenase 2 (IDH2), isocitrate dehydrogenase 3 (IDH3), malate dehydrogenase (MDH), and succinyl CoA (SCS) ligase, were assayed for VX inhibition. Only IDH2 NADP+ activity was shown to be inhibited directly. This result is consistent with other work reporting animals exposed to OP compounds exhibit reduced IDH activity. Though clearly a secondary mechanism for toxicity, this is the first time VX has been shown to directly interfere with energy metabolism. Taken together, the ABPP work described here suggests the discovery of novel protein-agent interactions, which could be useful for the development of novel diagnostics or potential adjuvant therapeutics.

Single-stage laparoscopic cholecystectomy and intraoperative endoscopic retrograde cholangiopancreatography: is this strategy feasible in Australia?

Currently in Australasia, concomitant cholecystolithiasis and choledocholithiasis are usually managed with two procedures: laparoscopic cholecystectomy (LC) and pre or postoperative endoscopic retrograde cholangiopancreatography (ERCP). This approach exposes the patient to the risk of complications from the common bile duct stone(s) while awaiting ERCP, the risks of the ERCP itself (particularly pancreatitis) and the need for a second anaesthetic. This article explores the evidence for a newer hybrid approach, single stage LC and intraoperative ERCP (SSLCE) and compares this approach with the commonly used alternatives. SSLCE offers reduced rates of pancreatitis, reduced length of hospital stay and reduced cost compared with the two-stage approach and requires only one anaesthetic. There is a reduced risk of bile leak compared with procedures that involve a choledochotomy, and ductal clearance rates are superior to trans-cystic exploration and equivalent to the standard two-stage approach. Barriers to widespread implementation relate largely to operating theatre logistics and availability of appropriate endoscopic expertise, although when bile duct stones are anticipated these issues are manageable. There is compelling justification in the literature to gather prospective evidence surrounding SSLCE in the Australian Healthcare system.

ISO standards for pathology - a step too far?

The International Standard, ISO 15189 which specifies requirements for quality and competence in medical laboratories was written by medical laboratory professionals. Since its first publication in 2003, it has raised awareness of the importance of medical laboratories with governments throughout the world and provided a tool with which laboratories may develop their quality management systems and assess their own competence. This paper examines the use of the Standard in the context of self-assessment, accreditation and regulation of medical laboratories.

Abstract B53: Utilizing bimolecular fluorescent complementation to identify inhibitors of RAL and KRAS

We have identified RAL activity to be vital for NSCLC survival independent of KRAS or EGFR mutation status in a large panel of adenocarcinomas and have developed a novel high throughput screening assay based on Bimolecular Fluorescent Complementation (BiFC) in order to identify small molecules that impair RAL function. By coupling RALA and RALB to the C-terminus of the Venus protein (VC) and coexpressing either with direct binding effector RALBP1 fused to the N-terminus of the Venus protein (VN) results in a fluorescent signal when RAL-RALBP1 binding occurs in cells. This allows for the interrogation of small molecules to disrupt RAL-RALBP1 binding interactions (resulting in loss of fluorescence) in a real time, high throughput manner. Our preliminary screen with a natural compound library identified 14 small molecules that demonstrated high activity in disrupting both RALA- and RALB-RALBP1 binding and fluorescence. We are currently investigating these compounds' mode of action and have recently expanded our assay to screen for molecules that impair mutant KRAS activity (VC-KRAS / RAF1-VN). BiFC provides a rapid, more physiologic method to identify molecules that can disrupt protein-protein interactions of targets considered ‘undruggable’ including membrane bound small GTPases such as RAL and KRAS.

Citation Format: Marytheresa Ifediba, David Burnett, Nicholas Hovda, William Burnett, Matthew VanBrocklin. Utilizing bimolecular fluorescent complementation to identify inhibitors of RAL and KRAS. [abstract]. In: Proceedings of the AACR Special Conference on RAS Oncogenes: From Biology to Therapy; Feb 24-27, 2014; Lake Buena Vista, FL. Philadelphia (PA): AACR; Mol Cancer Res 2014;12(12 Suppl):Abstract nr B53. doi: 10.1158/1557-3125.RASONC14-B53

Abstract 3732: Utilizing Bimolecular Fluorescent Complementation to Identify Inhibitors of RAL and KRAS

We have identified RAL activity to be vital for NSCLC survival independent of KRAS or EGFR mutation status in a large panel of adenocarcinomas and have developed a novel high throughput screening assay based on Bimolecular Fluorescent Complementation (BiFC) to identify small molecules that impair RAL function. Coupling RALA and RALB to the C-terminus of the Venus protein (VC) and coexpressing either with direct binding effector RALBP1 fused to the N-terminus of the Venus protein (VN) result in a fluorescent signal when RAL-RALBP1 binding occurs in cells. This allows for the interrogation of small molecules that disrupt RAL-RALBP1 binding interactions (resulting in loss of fluorescence) in a real time, high throughput manner. Our preliminary screen with a natural compound library identified 14 small molecules that demonstrated high activity in disrupting both RALA- and RALB-RALBP1 binding and fluorescence. We are currently investigating these compounds' mode of action and have recently expanded our assay to screen for molecules that impair mutant KRAS activity (VC-KRAS / RAF1-VN). BiFC provides a rapid, more physiologic method to identify molecules that can disrupt protein-protein interactions of targets considered ‘undruggable’, including membrane bound small GTPases such as RAL and KRAS.

Citation Format: Marytheresa Ifediba, David Burnett, Nicholas Hovda, William Burnett, Matthew VanBrocklin. Utilizing Bimolecular Fluorescent Complementation to Identify Inhibitors of RAL and KRAS. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3732. doi:10.1158/1538-7445.AM2014-3732

Cardiorespiratory fitness in breast cancer survivors

Maximal oxygen uptake (VO2max) has been used to assess risk for all-cause mortality and cardiovascular disease (CVD), and low VO2max has recently been associated with increased mortality from breast cancer. The purpose of this study was to determine the proportion of breast cancer survivors with 2 or more risk factors for CVD exhibiting a low VO2max and to determine whether sub-maximal endpoints which could be applied more readily to intervention research would correlate with the maximal treadmill test. We performed a single VO2max test on a treadmill with 30 breast cancer survivors age 30-60 (mean age 50.5 ± 5.6 years) who had 2 or more cardiac risk factors for CVD not related to treatment and who had received systemic therapy and or left chest radiation. Submaximal VO2 endpoints were assessed during the VO2max treadmill test and on an Arc trainer. Resting left ventricular ejection fraction (LVEF) was also assessed by echocardiogram (ECHO) or multi-gated acquisition scan (MUGA). A majority (23/30) of women had a VO2max below the 20th percentile based on their predicted normal values. The group mean resting LVEF was 60.5 ± 5.0%. Submaximal VO2 measures were strongly correlated with the maximal test including; 1) 85% age predicted maximum heart rate VO2 on treadmill, (r = .89; p < 0.001), 2) treadmill VO2 at anaerobic threshold (AT), (r = .83; p < 0.001), and 3) Arc VO2 at AT, (r = .80; p < 0.001). Breast cancer survivors with 2 or more CVD risk factors but normal LVEF had a low cardiorespiratory fitness level compared to normative values in the healthy population placing them at increased risk for breast cancer and cardiovascular mortality. Submaximal VO2 exercise testing endpoints showed a strong correlation with the VO2max test in breast cancer survivors and is a good candidate for testing interventions to improve cardiorespiratory fitness.

Cardiorespiratory fitness in breast cancer survivors

Eighty four halotolerant bacterial strains were isolated from the saline habitats and screened for growth at different NaCl concentrations. All grew well at 5% NaCl, but only 25% isolates showed growth at 20% NaCl concentration. Five strains SL3, SL32, SL35, J8W and PU62 growing well in 20% NaCl concentrations were further characterized for multiple plant growth promoting traits such as indole −3- acetic acid (IAA) production, HCN and siderophore production, ACC deaminase activity and P-solubilization. None were positive for HCN production and PCR amplification of acdS, the structural gene for ACC deaminase enzyme was found negative. 16S rRNA gene sequencing analysis of the five strains showed them to belong to two genera Bacillus and Hallobacillus. In vitro experiments showed that salt concentrations had significant inhibitory effects on development of seedlings but not on the growth of the bacterial strains. Inoculation of the 5 halotolerant bacterial strains to ameliorate salt stress (80 mM, 160 mM and 320 mM) in wheat seedlings produced an increase in root length of 71.7% in comparison with uninoculated positive controls. In particular, Hallobacillus sp. SL3 and Bacillus halodenitrificans PU62 showed more than 90% increase in root elongation and 17.4% increase in dry weight when compared to uninoculated wheat seedlings at 320 mM NaCl stress indicating a significant reduction of the deleterious effects of NaCl. These results indicate that halotolerant bacteria isolated from saline environments have potential to enhance plant growth under saline stress through direct or indirect mechanisms and would be most appropriate as bioinoculants under such conditions.

Abstract P2-11-17: Pilot Study to Evaluate a Home-based Exercise and Weight Loss Intervention on Cardiopulmonary Fitness and Markers of Breast Cancer Risk in Postmenopausal Breast Cancer Survivors

Background: BrCa survivors have an estimated 4-fold increase in risk for developing cardiovascular disease compared to women never treated for breast cancer and a nearly 3-fold increase in breast cancer mortality in women with an exercise capacity (VO2max) less than 28mL kg−1 min−1. Cardiac events are the second most common cause of death in long-term breast cancer (BrCa) survivors.

Purpose: We conducted a study to investigate the effects of standard exercise or structured exercise on targeted cardiovascular outcomes during a home-based diet and exercise intervention for breast cancer survivors.

Method: Cross-sectional within- and between-group design. A total of 19 breast cancer survivors, average age of 52.6+/−9.3, were enrolled in the study. A convenient sample was enrolled into two exercise groups receiving either: standard (150 minutes per week of usual care (exercise without instruction) cardiovascular exercise + resistance training) or structured (150 minutes per week of gradual increased intensity cardiovascular exercise + resistance training) exercise instruction along with a group based behavioral weight loss intervention. All participants underwent baseline and 17 week assessments including maximal exercise testing (VO2max and minutes on the treadmill), measurements of body composition (weight, BMI, % body fat), and assessment of quality of life.

Results: We report on the 16 participants who completed the baseline and 17 week assessments (9 = Standard Exercise Group; 7 = Structured Exercise Group). The structured exercise group exhibited significantly greater improvements in measures of cardiorespiratory fitness: VO2max (p = 0.05) and duration on treadmill (p = 0.02). No significant differences were noted for all other cardiorespiratory fitness testing outcomes. Significant improvements from baseline to 17 weeks were seen across both groups for all measures of body composition. Lean body mass did not significantly change from baseline to 17 weeks in both groups. There were no significant between group differences for change in body composition.

Comparison of hepatitis C virus treatment between incarcerated and community patients

The prevalence of chronic hepatitis C virus (HCV) infection among incarcerated individuals in the United States is estimated to be between 12% and 31%. HCV treatment during incarceration is an attractive option because of improved access to health care and directly observed therapy. We compared incarcerated and nonincarcerated HCV-infected patients evaluated for treatment at a single academic center between January 1, 2002 and December 31, 2007. During this period, 521 nonincarcerated and 388 incarcerated patients were evaluated for HCV treatment. Three hundred and nineteen (61.2%) nonincarcerated patients and 234 (60.3%) incarcerated patients underwent treatment with pegylated interferon and ribavirin. Incarcerated patients were more likely to be male, African-American race, and have a history of alcohol or intravenous drug use. Treated incarcerated patients were less likely to have genotype 1 virus and were less likely to have undergone previous treatment. There was a similar prevalence of coinfection with human immunodeficiency virus (HIV) in both groups. A sustained viral response (SVR) was achieved in 97 (42.9%) incarcerated patients, compared to 115 (38.0%) nonincarcerated patients (P = 0.304). Both groups had a similar proportion of patients that completed a full treatment course. Stepwise logistic regression was conducted, and the final model included full treatment course, non-genotype 1 virus, younger age at treatment start, and negative HIV status. Incarceration status was not a significant predictor when added to this model (P = 0.075).

CONCLUSION

In a cohort of HCV-infected patients managed in an academic medical center ambulatory clinic, incarcerated patients were as likely to be treated for HCV and as likely to achieve an SVR as nonincarcerated patients.