Upregulation of Haploinsufficient Gene Expression in the Brain by Targeting a Long Non-coding RNA Improves Seizure Phenotype in a Model of Dravet Syndrome

Dravet syndrome is a devastating genetic brain disorder caused by heterozygous loss-of-function mutation in the voltage-gated sodium channel gene SCN1A. There are currently no treatments, but the upregulation of SCN1A healthy allele represents an appealing therapeutic strategy. In this study we identified a novel, evolutionary conserved mechanism controlling the expression of SCN1A that is mediated by an antisense non-coding RNA (SCN1ANAT). Using oligonucleotide-based compounds (AntagoNATs) targeting SCN1ANAT we were able to induce specific upregulation of SCN1A both in vitro and in vivo, in the brain of Dravet knock-in mouse model and a non-human primate. AntagoNAT-mediated upregulation of Scn1a in postnatal Dravet mice led to significant improvements in seizure phenotype and excitability of hippocampal interneurons. These results further elucidate the pathophysiology of Dravet syndrome and outline a possible new approach for the treatment of this and other genetic disorders with similar etiology.

P17: PNEUMOMEDIASTINUM A RARE COMPLICATION OF COLONOSCOPY POLYPECTOMY SUCCESSFULLY TREATED WITH CONSERVATIVE MANAGEMENT

Purpose of Study

Colonoscopies are a relatively safe and are associated with few complications. We present a rare case of post-colonoscopy polypectomy resulting in a pneumomediastinum and subcutaneous emphysema.

Methods Used

An 84 year old male with a history of colonoscopy with polypectomy the day prior was admitted due to a syncopal episode. The only complaint was a small amount of dark red blood per rectum. On examination vital signs were stable, the patient appeared pale with dry membrane mucosa, abdominal and pulmonary exam were benign, labs were concerning for a Hgb 6.9 g/dl. Chest X-ray depicted free air beneath the right hemidiaphragm, computed tomography demonstrated pneumoretroperitoneum, pneumomediastinum and subcutaneous emphysema. Visceral angiogram failed to demonstrate any source of active bleeding. Due to the overall stable condition of the patient conservative management with prophylactic zosyn and transfusion of 2 units of packed red blood cells was initiated. Patient was discharged 5 days after admission with stable respiratory and hemodynamic signs.

Summary of Results

Diagnostic colonoscopies are relatively safe procedures with the most common complications being bleeding and perforations, with an incidence of less than .2%. Though perforations are rare they are associated with a high mortality and morbidity. Causes of perforation can be due to excessive insufflations, instrumental trauma and usually present with intra-abdominal free air but rarely with a pneumomediastinum. A pneumomediastinum is the presence of free air within the mediastinum and in our case was due to a micro-perforation from a colonic polypectomy. The colonic wall defect allowed free air into the retroperitoneum, which spread along the fascial planes and entered the mediastinum and subcutaneous tissues. The most sensitive test for pneumomediastinum is computed tomography and extra-pulmonary causes of pneumomediastinum can be successfully treated conservatively with rest and antibiotics.

Conclusions

Though complications from polypectomies are rare, they can be associated with a high morbidity and mortality but rarely associated with pneumomediastinum and in certain stable patients can be treated with conservative management.

Radiographer Delivered Fluoroscopy Reduces Radiation Exposure During Endoscopic Urological Procedures

INTRODUCTION

The 1999 Ionising Radiation Regulations recommend that medical professionals using ionising radiation should aim to keep exposure as 'low as reasonably practicable'. Urologists regularly use fluoroscopy during endoscopic surgical procedures. In some institutions, this is delivered by a radiographer whereas in others, it is delivered by the urological surgeon.

OBJECTIVES

To determine if radiographer-delivered fluoroscopy can reduce the exposure to ionising radiation during urological procedures.

METHODS

An analysis of 395 consecutive patients, who underwent endoscopic urological procedures requiring fluoroscopy, was performed simultaneously across two institutions, over a 4 month period. 321 patients were matched and included in the analysis.

RESULTS

Radiographer delivered fluoroscopy was associated with reduced ionising radiation exposure for retrograde pyelography procedures ED 0.09626 vs. 1.323 mSev, p= 0.0003, and endoscopic stone surgeries ED 0.3066 Vs. 0.5416 mSev, p=0.0039, but not for ureterorenoscopic stone surgeries 0.4880 vs. 0.2213 mSev, p=0.8292.

CONCLUSION

Radiographer delivered fluoroscopy could reduce the patient's exposure to ionising radiation for some urological procedures.

Closing the audit cycle: improving short-term outcomes of oesophagectomy in a provincial hospital

A previously published study regarding the outcomes of oesophagectomy at a provincial hospital identified issues with perioperative care (Al-Herz et al 2012). The aim of this study was to evaluate the effect of changes in management at the institution concerned. This was a cohort study which compared the outcomes of 30 patients undergoing oesophagectomy before the unit audit and 30 patients after it. Demographics, operative details, recovery parameters, and oncological data were collected retrospectively. There was a significant reduction in the use of intravenous fluid, both intraoperatively (6.6 vs 3.3L, P < 0.0001) and during the first 24 hours (9.2 vs 5.5L, P < 0.0001). Patients were extubated three days earlier (P < 0.001) after the audit, and the percentage of patients requiring tracheostomy was smaller (26.7% vs 0%, P = 0.003). The length of total hospital stay was shorter (15 vs 13 days, P = 0.035). We conclude that the publication of a unit audit changed perioperative practice and resulted in a significant improvement in the short term outcomes after oesophagectomy.

Differentiation of functional constipation and constipation predominant irritable bowel syndrome based on Rome III criteria: a population-based study

BACKGROUND

While the Rome III classification recognises functional constipation (FC) and constipation predominant IBS (IBS-C) as distinct disorders, recent evidence has suggested that these disorders are difficult to separate in clinical practice.

AIM

To identify whether clinical and lifestyle factors differentiate Rome III-defined IBS-C from FC based on gastrointestinal symptoms and lifestyle characteristics.

METHOD

3260 people randomly selected from the Australian population returned a postal survey. FC and IBS-C were defined according to Rome III. The first model used logistic regression to differentiate IBS-C from FC based on lifestyle, quality-of-life and psychological characteristics. The second approach was data-driven employing latent class analysis (LCA) to identify naturally occurring clusters in the data considering all symptoms involved in the Rome III criteria for IBS-C and FC.

RESULTS

We found n = 206 (6.5%; 95% CI 5.7-7.4%) people met strict Rome III FC whereas n = 109 (3.5%; 95% CI 2.8-4.1%) met strict Rome III IBS-C. The case-control approach indicated that FC patients reported an older age at onset of constipation, were less likely to exercise, had higher mental QoL and less health care seeking than IBS-C. LCA yielded one latent class that was predominantly (75%) FC, while the other class was approximately half IBS-C and half FC. The FC-dominated latent class had clearly lower levels of symptoms used to classify IBS (pain-related symptoms) and was more likely to be male (P = 0.046) but was otherwise similar in distribution of lifestyle factors to the mixed class.

CONCLUSION

The latent class analysis approach suggests a differentiation based more on symptom severity rather than the Rome III view.

Albiglutide does not impair the counter-regulatory hormone response to hypoglycaemia: a randomized, double-blind, placebo-controlled, stepped glucose clamp study in subjects with type 2 diabetes mellitus

AIM

To determine if the glucagon-like peptide-1 (GLP-1) receptor agonist albiglutide, once weekly, impairs counter-regulatory responses during hypoglycaemia.

METHODS

We conducted a randomized, double-blind, parallel, placebo-controlled study in subjects with type 2 diabetes mellitus. A single dose of albiglutide 50 mg (n = 22) or placebo (n = 22) was administered on day 1. Glucose was clamped on day 4 (to coincide with the approximate albiglutide maximum plasma concentration) at 9.0, 5.0, 4.0, 3.3 and 2.8 mmol/l (162, 90, 72, 59.4 and 50.4 mg/dl), with a post-clamp recovery period to 3.9 mmol/l (70 mg/dl). Hormone measurements were made at each plateau and adverse events (AEs) were recorded.

RESULTS

The counter-regulatory hormones glucagon, epinephrine, norepinephrine, growth hormone and cortisol were appropriately suppressed when plasma glucose levels were >4.0 mmol/l (>72 mg/dl), but increased in the albiglutide and placebo groups with glucose levels <3.3 mmol/l (<59.4 mg/dl) in response to hypoglycaemia. The area under the curve geometric mean ratios (albiglutide : placebo), calculated from the clamped plateau of 4.0 mmol/l (72 mg/dl) to the glucose recovery point, were not significantly different for any of the counter-regulatory hormones. When plasma glucose levels were >5.0 mmol/l (>90 mg/dl), albiglutide increased pancreatic β-cell secretion of C-peptide in a glucose-dependent manner to a greater extent than did placebo, and it was suppressed in each group when levels were <4.0 mmol/l (<72 mg/dl). No significant difference between groups was observed in the recovery time to glucose level ≥3.9 mmol/l (≥70 mg/dl). There were no clinically relevant differences in AEs or other safety variables.

CONCLUSIONS

A single 50-mg dose of albiglutide was well tolerated and did not impair the counter-regulatory response to hypoglycaemia. These data provide mechanistic evidence supporting the low intrinsic hypoglycaemic potential of albiglutide.

Predicting fat quality from pigs fed reduced-oil corn dried distillers grains with solubles by near infrared reflectance spectroscopy: fatty acid composition and iodine value

This study tested the ability of near infrared reflectance spectroscopy (NIRS) to estimate the fatty acid (FA) composition and iodine value (IV) of backfat from carcasses of pigs fed reduced-oil corn dried distillers grains with solubles. NIRS was suitable for screening purposes for the proportions of total saturated, monounsaturated, polyunsaturated, n-3 and n-6 FAs and some individual FAs such as C16:0, C18:1, C18:2n-6 and C18:3n-3 (R(2)=0.80-0.89; RMSECVs, root mean square errors of cross-validation=0.21-1.37% total FA) in both cold and warm intact backfat samples. This technology also met the requirements for a quick screening for the backfat IV in both cold and warm intact samples (R(2)=0.90 and 0.87; RMSECVs=1.66 and 1.80% total FA, respectively), which would help provide differential feed-back to pig producers and the feed industry and may provide the opportunity for breeding pigs for a desirable fat quality.

The effects of lipids and surfactants on TLR5-proteoliposome functionality for flagellin detection using surface plasmon resonance biosensing

The use of proteoliposomes as affinity elements in conjunction with a surface plasmon resonance sensor is a high-sensitivity alternative for the detection of multiple analytes. However, one of the most important aspects of these conformations is maintaining the functionality of the immobilized protein, which is determined by the choice of lipids and surfactants employed in the reconstitutions. Previously, we demonstrated the functionality of TLR5-proteoliposomes as screening affinity elements of bacterial flagellin. In this new study we change the conditions of immobilization of TLR5 and evaluate how the fluidity of the membrane and the final size of the liposomes affect the functionality of the construct and thus increase their utility as an affinity element for design of new biosensors. In particular, we used reconstructions into preformed liposomes composed of the lipids POPC, POPC-DMPC and POPC-POPE mediated by the use of surfactants OG, Triton X100, and DDM, respectively. The affinity results were evaluated by SPR technology proteoliposomes and were correlated with the anisotropic change in the membrane status; the final sizes of the proteoliposomes were estimated. Our results clearly show the dependence of fluidity and final size of the proteoliposomes with surface plasmon resonance affinity measurements.