Mepilex Border Sacrum and Heel Dressings for the Prevention of Pressure Ulcers: A NICE Medical Technology Guidance

Mepilex Border Sacrum and Heel dressings are self-adherent, multilayer foam dressings designed for use on the heel and sacrum aiming to prevent pressure ulcers. The dressings are used in addition to standard care protocols for pressure ulcer prevention. The National Institute for Health and Care Excellence (NICE) selected Mepilex Border Sacrum and Heel dressings for evaluation. The External Assessment Centre (EAC) critiqued the company's submission. Thirteen studies (four randomised controlled trials and nine nonrandomised comparative studies) were included. The majority of studies compared Mepilex Border Sacrum dressings (plus standard care) with standard care alone. Comparative evidence for Mepilex Border Heel dressings was limited. A meta-analysis indicated a non-statistically significant difference in favour of Mepilex Border Sacrum dressings for pressure ulcer incidence [RR 0.51 (95% CI 0.22-1.18)]. The company produced a de novo cost model, which was critiqued by the EAC. After the EAC updated input parameters, cost savings of £19 per patient compared with standard care alone for pressure ulcer prevention were estimated with Mepilex Border dressings predicted to be cost saving in 57% of iterations. The Medical Technologies Advisory Committee reviewed the evidence and judged that, although Mepilex Border Heel and Sacrum dressings have potential to prevent pressure ulcers in people who are considered to be at risk in acute care settings, further evidence is required to address uncertainties around the claimed benefits of the dressings and the incidence of pressure ulcers in an NHS acute-care setting. After a public consultation, NICE published this as Medical Technology Guidance 40.

Economic evidence for nonpharmacological asthma management interventions: A systematic review

Asthma management, education and environmental interventions have been reported as cost‐effective in a previous review (Pharm Pract (Granada), 2014;12:493), but methods used to estimate costs and outcomes were not discussed in detail. This review updates the previous review by providing economic evidence on the cost‐effectiveness of studies identified after 2012, and a detailed assessment of the methods used in all identified studies. Twelve databases were searched from 1990 to January 2016, and studies included economic evaluations, asthma subjects and nonpharmacological interventions written in English. Sixty‐four studies were included. Of these, 15 were found in addition to the earlier review; 53% were rated fair in quality and 47% high. Education and self‐management interventions were the most cost‐effective, in line with the earlier review. Self‐reporting was the most common method used to gather resource‐use data, accompanied by bottom‐up approaches to estimate costs. Main outcome measures were asthma‐related hospitalizations (69%), quality of life (41%) and utility (38%), with AQLQ and the EQ‐5D being the most common questionnaires measured prospectively at fixed time points. More rigorous costing methods are needed with a more common quality of life tool to aid greater replicability and comparability amongst asthma studies.

Adeno-associated virus-mediated delivery of BCL-w gene improves outcome after transient focal cerebral ischemia

A recombinant adeno-associated virus (rAAV) vector was used to overexpress the anti-apoptotic Bcl-2-family protein, BCL-w, in rat brain. Three weeks after injecting the vector into cerebral cortex and striatum on one side, temporary focal ischemia was induced by occlusion of the ipsilateral middle cerebral artery for 90 min, followed by reperfusion for 24 h. BCL-w expression was increased in cerebral cortex and striatum--and in neurons, astroglia and endothelial cells--in the brains of rats that received the rAAV-BCL-w vector, compared to rats given phosphate-buffered saline or a control vector containing the gene for green fluorescent protein. Recipients of the rAAV-BCL-w vector also showed a 30% reduction in infarct size and a 33-40% improvement in neurological function, compared to the control groups. These results provide evidence for a role of BCL-w in regulating histological and functional outcome after focal cerebral ischemia.

Recombinant adeno-associated virus vector-based gene transfer for defects in oxidative metabolism

Defects in oxidative metabolism may be caused by mutations either in nuclear genes or in mitochondrial DNA (mtDNA). We tested the hypothesis that recombinant adeno-associated virus (rAAV) could be used to complement mtDNA mutations. AAV vector constructs were designed to express the reporter gene encoding green fluorescent protein (GFP), fused to a targeting presequence that directed GFP to be translocated into mitochondria. These vectors mediated expression of mitochondrial-localized GFP, as indicated by fluorescence microscopy and electron microscopy, in respiring human embryonic kidney 293 cells and nonrespiring mtDNA-deficient (rho 0) cells. However, when sequences encoding hydrophobic segments of proteins normally encoded by mtDNA were inserted between the presequence and GFP, mitochondrial import failed to occur. In similar experiments, a fusion was created between pyruvate dehydrogenase (PDH) E1 alpha subunit, a nuclear-encoded mitochondrial gene with its own targeting presequence, and GFP. With this construct, expression of GFP was observed in mitochondria in vitro and in vivo. We conclude that the hydrophobicity of mtDNA-encoded proteins limits their ability to be transported from the cytoplasm. However, rAAV-based gene therapy may hold promise for gene therapy of PDH deficiency, the most common biochemically proven cause of congenital lactic acidosis.