Electroporation enhances transfection efficiency in murine cutaneous wounds

Transfection of wounds with DNA-encoding growth factors has the potential to improve healing, but current means of nonviral gene delivery are inefficient. Repeated high doses of DNA, necessary to achieve reliable gene expression, are detrimental to healing. We assessed the ability of in vivo electroporation to enhance gene expression. Full-thickness cutaneous excisional wounds were created on the dorsum of female mice. A luciferase- encoding plasmid driven by a CMV promoter was injected at the wound border. Following plasmid administration, electroporative pulses were applied to injection sites. Pulse parameters were varied over a range of voltage, duration, and number. Animals were euthanized at intervals after transfection and the luciferase activity measured. Application of electric pulses consistently increased luciferase expression. The electroporative effect was most marked at a plasmid dose of 50 micro g, where an approximate tenfold increase was seen. Six 100- micro s-duration pulses of 1750 V/cm were found to be the most effective in increasing luciferase activity. High numbers of pulses tended to be less effective than smaller numbers. This optimal electroporation regimen had no detrimental effect on wound healing. We conclude that electroporation increases the efficiency of transgene expression and may have a role in gene therapy to enhance wound healing.     

Introduction, availability and role of simulation in surgical education and training: Review of current evidence and recommendations from the Association of Surgeons in Training

The utility of simulation in surgical training is now well-established, with proven validity and demonstrable transfer of skills to the clinical setting. Through a reduction in the technical learning curve, simulation can prepare surgeons for actual practice and in doing so it has the potential to improve both patient safety and service efficiency. More broadly, multi-disciplinary simulation of the theatre environment can aid development of non-technical skills and assist in preparing theatre teams for infrequently encountered scenarios such as surgical emergencies. The role of simulation in the formal training curriculum is less well-established, and availability of facilities for this is currently unknown. This paper reviews the contemporary evidence supporting simulation in surgical training and reports trainee access to such capabilities. Our national surgical trainee survey with 1130 complete responses indicated only 41.2% had access to skills simulator facilities. Of those with access, 16.3% had availability out-of-hours and only 54.0% had local access (i.e. current work place). These results highlight the paucity in current provision of surgical skills simulator facilities, and availability (or awareness of availability) varies widely between region, grade and specialty. Based on these findings and current best-evidence, the Association of Surgeons in Training propose 22 action-points for the introduction, availability and role of simulation in surgical training. Adoption of these should guide trainers, trainees and training bodies alike to ensure equitable provision of appropriate equipment, time and resources to allow the full integration of simulation into the surgical curriculum.     

Continent catheterizable conduits: which stoma, which conduit and which reservoir?

OBJECTIVE: To assess the outcome of the various methods used in creating continent catheterizable conduits. PATIENTS AND METHODS: The case notes were reviewed from 89 patients who underwent the formation of 112 continent catheterizable conduits. RESULTS: Sixty-five conduits were Mitrofanoff and 47 were antegrade colonic enema (ACE); 21 patients had both. At a mean follow-up of 34 months, 95 (85%) conduits were still in use. There was no difference in complications between the Mitrofanoff and ACE conduits; 109 (97%) conduits were continent and stomal stenosis occurred 35 (31%). There was no significant difference relating to the conduit used, the reservoir, the stoma type or the stoma site. Only 39% of patients required no revisional surgery. CONCLUSION: Although urinary and fecal continence can be achieved in most patients there is a high burden of complications and revisional surgery. All patients should be counselled accordingly.     

Detrusor myotomy: a 5-year review in unstable and non-compliant bladders

OBJECTIVE: To identify urodynamic factors that might determine the clinical outcome of detrusor myotomy in incontinent children. PATIENTS AND METHODS: Six girls and three boys (aged 5-14 years) underwent detrusor myotomy for severe urinary incontinence. Seven children had spina bifida, one had traumatic paraplegia and one had low bladder compliance. The patients were followed for a minimum of 5 years. RESULTS: Urodynamic studies before surgery showed that three patients had normal compliance with grossly unstable detrusor contractions, and six had low bladder compliance with few phasic detrusor contractions. Detrusor leak-point pressures were > 40 cmH2O in five patients and < 40 cmH2O in four. Only two patients, both with grossly unstable detrusor contractions and leak-point pressures of > 40 cmH2O, had a successful 5-year outcome. The other seven patients remained incontinent; six underwent further surgery and one died from unrelated causes. CONCLUSION: Detrusor myotomy appears to have the best outcome in those patients with marked phasic unstable detrusor contractions with a competent urethral sphincter. In this group it may have distinct advantages over more commonly used procedures.     

Predictors of mortality in adult trauma patients: the physiologic trauma score is equivalent to the Trauma and Injury Severity Score

Background:

Several statistical models (Trauma and Injury Severity Score [TRISS], New Injury Severity Score [NISS], and the International Classification of Disease, Ninth Revision-based Injury Severity Score [ICISS]) have been developed over the recent decades in an attempt to accurately predict outcomes in trauma patients. The anatomic portion of these models makes them difficult to use when performing a rapid initial trauma assessment. We sought to determine if a Physiologic Trauma Score, using the systemic inflammatory response syndrome (SIRS) score in combination with other commonly used indices, could accurately predict mortality in trauma.

Study Design:

Prospective data were analyzed in 9,539 trauma patients evaluated at a Level I Trauma Center over a 30-month period (January 1997 to July 1999). A SIRS score (1 to 4) was calculated on admission (1 point for each: temperature >38°C or <36°C, heart rate >90 beats per minute, respiratory rate >20 breaths per minute, neutrophil count > 12,000 or < 4,000. SIRS score, Injury Severity Score (ISS), Revised Trauma Score (RTS), TRISS, Glasgow Coma Score, age, gender, and race were used in logistic regression models to predict trauma patients’ risk of death. The area under the receiver-operating characteristic curves of sensitivity versus 1-specificity was used to assess the predictive ability of the models.

Results:

The study cohort of 9,539 trauma patients (of which 7,602 patients had complete data for trauma score calculations) had a mean ISS of 9 ± 9 (SD) and mean age of 37 ± 17 years. SIRS (SIRS score ≥ 2) was present in 2,165 of 7,602 patients (28.5%). In single-variable models, TRISS and ISS were most predictive of outcomes. A multiple-variable model, Physiologic Trauma Score combining SIRS score with Glasgow Coma Score and age (Hosmer-Lemenshow CHI-SQUARE = 4.74) was similar to TRISS and superior to ISS in predicting mortality. The addition of ISS to this model did not significantly improve its predictive ability.

Conclusions:

A new statistical model (Physiologic Trauma Score), including only physiologic variables (admission SIRS score combined with Glasgow Coma Score and age) and easily calculated at the patient bedside, accurately predicts mortality in trauma patients. The predictive ability of this model is comparable to other complex models that use both anatomic and physiologic data (TRISS, ISS, and ICISS).     

Efficacy of a topical concentrated surfactant gel on microbial communities in non‐healing diabetic foot ulcers with chronic biofilm infections: A proof‐of‐concept study

This proof‐of‐concept study sought to determine the effects of standard of care (SOC) and a topically applied concentrated surfactant gel (SG) on the total microbial load, community composition, and community diversity in non‐healing diabetic foot ulcers (DFUs) with chronic biofilm infections. SOC was provided in addition to a topical concentrated SG, applied every 2 days for 6 weeks. Wound swabs were obtained from the base of ulcers at baseline (week 0), week 1, mid‐point (week 3), and end of treatment (week 6). DNA sequencing and real‐time quantitative polymerase chain reaction (qPCR) were employed to determine the total microbial load, community composition, and diversity of patient samples. Tissue specimens were obtained at baseline and scanning electron microscopy and peptide nucleic acid fluorescent in situ hybridisation with confocal laser scanning microscopy were used to confirm the presence of biofilm in all 10 DFUs with suspected chronic biofilm infections. The application of SG resulted in 7 of 10 samples achieving a reduction in mean log10 total microbial load from baseline to end of treatment (0.8 Log10 16S copies, ±0.6), and 3 of 10 samples demonstrated an increase in mean Log10 total microbial load (0.6 log10 16S copies, ±0.8) from baseline to end of treatment. Composition changes in microbial communities were driven by changes to the most dominant bacteria. Corynebacterium sp. and Streptococcus sp. frequently reduced in relative abundance in patient samples from week 0 to week 6 but did not disappear. In contrast, Staphylococcus sp., Finegoldia sp., and Fusobacterium sp., relative abundances frequently increased in patient samples from week 0 to week 6. The application of a concentrated SG resulted in varying shifts to diversity (increase or decrease) between week 0 and week 6 samples at the individual patient level. Any shifts in community diversity were independent to changes in the total microbial loads. SOC and a topical concentrated SG directly affect the microbial loads and community composition of DFUs with chronic biofilm infections.     

Diversion procto-colitis: response to treatment with short-chain fatty acids

BACKGROUND/PURPOSE: Diversion procto-colitis (DPC) results from a deficiency of luminal short-chain fatty acids (SCFAs). Endoscopic and histopathologic features of the disorder are almost universally present in defunctioned bowel, but symptomatic DPC is less common. METHODS: Five children with symptomatic DPC underwent endoscopy and rectosigmoid biopsies. An endoscopic index (EI) was used to quantify disease severity. An SCFA mixture was administered into the defunctioned bowel. RESULTS: A good clinical response and improvement in the endoscopic index occurred in all children. Undiversion or rectal excision was carried out in 4 and was curative in each case. One child is awaiting a redo pull through. CONCLUSIONS: DPC should be considered in children with a defunctioned colon presenting with evidence of colitis. Histopathology provides supportive evidence and SCFAs may provide effective relief of symptoms. Stoma reversal or rectal excision is curative.     

Charlson Co‐morbidity Index and albumin significantly associated with fracture risk in peritoneal dialysis patients

Published literature on fracture in dialysis patients seldom addressed the effect of co‐morbidity and malnutrition. In this study, we reported the incidence and risk factors for fracture in peritoneal dialysis patients. Peritoneal dialysis patients who had fractures between 2006 and 2011 were recruited. Demographic data, details of fracture, Charlson Co‐morbidity Index (CCI) and biochemical parameters were also collected. Non‐fracture controls, matched for age, gender and duration of dialysis, were also recruited at ratio 1:1 for fracture risk analysis. The incidence of fracture was 1 in 37 patient‐years. The commonest site of fracture was neck of femur (n = 16, 55.2%). Twenty‐four patients (82.8%) developed fracture after slip and fall injury. Eight out of 17 self‐ambulatory patients (47.1%) became non‐ambulatory after fracture. Infection was the commonest complication during hospitalization. Univariant analysis demonstrated high CCI (P = 0.001), hypoalbuminaemia (P < 0.001), loss of self autonomy (P = 0.006) and non‐ambulatory state (P = 0.011) significantly associated with increased fracture risk. However, only CCI (odds ratio (OR) 1.373, P = 0.028) and albumin (OR 0.893, P = 0.025) increased fracture risk significantly on multivariant analysis. Bone profile and parathyroid hormone were not significant risk factors. To conclude, fracture associated with adverse outcome in peritoneal dialysis patients. High CCI score and hypoalbuminaemia significantly increase risk of fracture.