Study protocol for a randomised controlled trial of insulin delivery by continuous subcutaneous infusion compared to multiple daily injections

BACKGROUND: Intensive insulin therapy with continuous subcutaneous insulin infusion (CSII) devices or multiple daily injections (MDI) reduces the risk of long-term vascular complications of type I diabetes (TID). Both treatments are used routinely, but there is little evidence to demonstrate superiority of either treatment. If CSII treatment reduces the risk of long-term complications or is associated with an improved quality of life (QoL), the additional cost of this therapy may be compensated for by a reduction in long-term health expenditure. If there is no demonstrable difference between treatments, health-care resources may be better invested elsewhere. This study aims to address this gap in knowledge. METHODS/DESIGN: This is a pragmatic, randomised controlled trial (RCT). Fifteen centres, selected to represent a population with a broad demographic, will recruit 316 patients, newly diagnosed with TID, aged between 7 months and 15 years. Exclusion criteria include additional pathologies or treatments likely to affect glycaemic control and a first-degree relative with TID. Randomisation to CSII or MDI is stratified for age, gender and recruiting centre. The randomised treatment starts within 15 days of diagnosis. Patients will be trained to adjust their insulin dose according to carbohydrate intake and blood glucose level. Study visits coincide with routine clinic appointments at 3, 6, 9 and 12 months when data relating to routine clinical assessments, adverse events and concomitant medications are collected. Health utilities questionnaires are completed at each visit and a diabetes-specific QoL questionnaire (PedsQL) at diagnosis, 6 and 12 months. The primary outcome is glycaemic control (HbA1c) at 12 months. Secondary outcome measures include QoL, insulin use, growth and weight gain, adverse events and a health economics appraisal. DISCUSSION: This is the first adequately powered RCT comparing CSII and MDI in a non-selected population, treated according to standard practice guidelines. It will produce data that are meaningful to individual patients and local and national policymakers. TRIAL REGISTRATION: The study was registered with the European Clinical Trials Database on 4 November 2010, reference 2010-023792-25

A randomised controlled trial of treatment for post-stroke homonymous hemianopia: screening and recruitment

The authors report the screening process and recruitment figures for the VISION (Visual Impairment in Stroke; Intervention Or Not) trial. This is a prospective, randomised, single-blinded, three-arm controlled trial in 14 UK acute hospital stroke units. Stroke teams identified stroke survivors suspected as having homonymous hemianopia. Interventions included Fresnel prisms versus visual search training versus standard care (information only). Primary outcome was change in visual field assessment from baseline to 26 weeks. Secondary measures included change in quality-of-life questionnaires. Recruitment opened in May 2011. A total of 1171 patients were screened by the local principal investigators. Of 1171 patients, 178 (15.2%) were eligible for recruitment: 87 patients (7.4%) provided consent and were recruited; 91 patients (7.8%) did not provide consent, and 993 of 1171 patients (84.8%) failed to meet the eligibility criteria. Almost half were excluded due to complete/partial recovery of hemianopia (43.6%; n = 511). The most common ineligibility reason was recovery of hemianopia. When designing future trials in this area, changes in eligibility criteria/outcome selection to allow more patients to be recruited should be considered, e.g., less stringent levels of visual acuity/refractive error. Alternative outcomes measurable in the home environment, rather than requiring hospital attendance for follow-up, could facilitate increased recruitment

Proteasomal modulation of cellular SNAT2 (SLC38A2) abundance and function by unsaturated fatty acid availability

Expression and activity of the System A/SNAT2 (SLC38A2) amino acid transporter is up-regulated by amino acid starvation and hypertonicity by a mechanism dependent on both ATF4-mediated transcription of the SLC38A2 gene and enhanced stabilization of SNAT2 itself, which forms part of an integrated cellular stress response to nutrient deprivation and osmotic stress. Here we demonstrate that this adaptive increase in System A function is restrained in cells subjected to prior incubation with linoleic acid (LOA, an unsaturated C18:2 fatty acid) for 24 h. While fatty acid treatment had no detectable effect upon stress-induced SNAT2 or ATF4 gene transcription, the associated increase in SNAT2 protein/membrane transport activity were strongly suppressed in L6 myotubes or HeLa cells preincubated with LOA. Cellular ubiquitination of many proteins was increased by LOA and although the fatty acid-induced loss of SNAT2 could be attenuated by proteasomal inhibition, the functional increase in System A transport activity associated with amino acid starvation/hypertonicity that depends upon processing/maturation and delivery of SNAT2 to the cell surface could not be rescued. LOA up-regulated cellular expression of Nedd4.2, an E3-ligase implicated in SNAT2 ubiquitination, but shRNA-directed Nedd4.2 gene silencing could not curb fatty acid-induced loss of SNAT2 adaptation. However, expression of SNAT2 in which seven putative lysyl-ubiquitination sites in the cytoplasmic N-terminal domain were mutated to alanine protected SNAT2 against LOA-induced proteasomal degradation. Collectively, our findings indicate that increased availability of unsaturated fatty acids can compromise the stress-induced induction/adaptation in SNAT2 expression and function by promoting its degradation via the ubiquitin-proteasome system