Regulation of Dendritic Protein Synthesis by Miniature Synaptic Events

We examined dendritic protein synthesis after a prolonged blockade of action potentials alone and after a blockade of both action potentials and miniature excitatory synaptic events (minis). Relative to controls, dendrites exposed to a prolonged blockade of action potentials showed diminished protein synthesis. Dendrites in which both action potentials and minis were blocked showed enhanced protein synthesis, suggesting that minis inhibit dendritic translation. When minis were acutely blocked or stimulated, an immediate increase or decrease, respectively, in dendritic translation was observed. Taken together, these results reveal a role for miniature synaptic events in the acute regulation of dendritic protein synthesis in neurons

Protocol for a single-centre randomised controlled trial of multimodal periarticular anaesthetic infiltration versus single-agent femoral nerve blockade as analgesia for total knee arthroplasty: Perioperative Analgesia for Knee Arthroplasty (PAKA)

Introduction: Total knee arthroplasty (TKA) surgery causes postoperative pain. The use of perioperative injections around the knee containing local anaesthetic, opiates and non-steroidal anti-inflammatory drugs has increased in popularity to manage pain. Theoretical advantages include reduced requirements for analgesia and earlier mobilisation. We propose a single-centre randomised controlled trial of multimodal periarticular anaesthetic infiltration versus femoral nerve anaesthetic blockade as analgesia for TKA. The aim is to determine, in patients undergoing TKA, if there is a difference in patient-reported pain scores on the visual analogue scale (VAS) prior to physiotherapy on day 1 postoperatively between treatment groups. Methods and analysis: Patients undergoing a primary unilateral TKA at University Hospitals Coventry and Warwickshire Hospitals will be assessed for eligibility. A total of 264 patients will provide 90% power to detect a difference of 12 mm on the VAS on day 1 postoperatively at the 5% level. The trial will use 1:1 randomisation, stratified by mode of anaesthetic. Primary outcome measure will be the VAS for pain prior to physiotherapy on day 1. Secondary outcome measures include VAS on day 2, total use of opiate analgesia up to 48 h, ordinal pain scores up to 40 min after surgery, independent functional knee physiotherapist assessment on days 1 and 2. Oxford knee Scores (OKS), EuroQol (EQ-5D) and Douleur Neuropathic Pain Scores (DN2) will be recorded at baseline, 6 weeks and 12 months. Adverse events will be recorded up to 12 months. Analysis will investigate differences in VAS on day 1 between the two treatment groups on an intention-to-treat basis. Tests will be two-sided and considered to provide evidence for a significant difference if p values are less than 0.05. Ethics and dissemination: NRES Committee West Midlands, 23 September 2013 (ref: 13/WM/0316). The results will be disseminated via peer-reviewed publications and conference presentations. Trial registration numbers: ISRCTN 60611146 and EUDRACT Number 2013-002439-10 (protocol code number PAKA-33601-AS117013); Pre-results

A pragmatic randomised controlled trial comparing the efficacy of a femoral nerve block and periarticular infiltration for early pain relief following total knee arthroplasty

Aims The aim of this study was to compare the effectiveness of a femoral nerve block and a periarticular infiltration in the management of early post-operative pain after total knee arthroplasty (TKA). Patents and methods A pragmatic, single centre, two arm parallel group, patient blinded, randomised controlled trial was undertaken. All patients due for TKA were eligible. Exclusion criteria included contraindications to the medications involved in the study and patients with a neurological abnormality of the lower limb. Patients received either a femoral nerve block with 75 mg of 0.25% levobupivacaine hydrochloride around the nerve, or periarticular infiltration with 150 mg of 0.25% levobupivacaine hydrochloride, 10 mg morphine sulphate, 30 mg ketorolac trometamol and 0.25 mg of adrenaline all diluted with 0.9% saline to make a volume of 150 ml. Results A total of 264 patients were recruited and data from 230 (88%) were available for the primary analysis. Intention-to-treat analysis of the primary outcome measure of a visual analogue score for pain on the first post-operative day, prior to physiotherapy, was similar in both groups. The mean difference was -0.7 (95% confidence interval (CI) -5.9 to 4.5; p = 0.834). The periarticular group used less morphine in the first post-operative day compared with the femoral nerve block group (74%, 95% CI 55 to 99). The femoral nerve block group reported 39 adverse events, of which 27 were serious, in 31 patients and the periarticular group reported 51 adverse events, of which 38 were serious, in 42 patients up to six weeks post-operatively. None of the adverse events were directly attributed to either of the interventions under investigation. Conclusion Periarticular infiltration is a viable and safe alternative to femoral nerve block for the early post-operative relief of pain following TKA. Cite this article: Bone Joint J 2017;99-B:904-11

Childhood Maltreatment, Stressful Life Events, and Alcohol Craving in Adult Drinkers

Background: Little is known about the relationship between stressful life events and alcohol craving in the general population, and whether a history of childhood maltreatment sensitizes individuals to crave alcohol after adult stressors. Methods: Participants were 22,147 past-year drinkers from Wave 2 (2004 to 2005) of the National Epidemiologic Survey on Alcohol and Related Conditions. A structured, face-to-face interview assessed past-year stressful life events, alcohol craving, and history of childhood maltreatment. Logistic regression was used to generate adjusted odds ratios (aOR) to evaluate the relationship between stressful life events and craving, adjusting for demographic characteristics and parental history of alcoholism. Interaction between stressful life events and childhood maltreatment was also assessed. Results: Compared to participants with no stressful life events, those with ≥3 events had increased odds of moderate alcohol craving (aOR = 3.15 [95% CI = 2.30 to 4.33]) and severe craving (aOR = 8.47 [95% CI = 4.78 to 15.01]). Stressful life events and childhood maltreatment interacted in predicting severe craving (p = 0.017); those with ≥3 events were at higher risk of craving if they had been exposed to childhood maltreatment. Conclusions: A direct relationship between stressful life events and risk of alcohol craving was observed. Further, history of childhood maltreatment increased the salience of stressful life events in adulthood. Future studies should examine the role of psychiatric comorbidity in more complex models of stress sensitization and alcohol craving

The feasibility of conducting a randomised controlled trial comparing arthroscopic hip surgery to conservative care for patients with femoroacetabular impingement syndrome : the FASHIoN feasibility study

BACKGROUND: Femoroacetabular impingement (FAI) is a syndrome of hip or groin pain associated with shape abnormalities of the hip joint. Treatments include arthroscopic surgery and conservative care. This study explored the feasibility of a randomised controlled trial to compare these treatments. OBJECTIVES: The objectives of this study were to estimate the number of patients available for a full randomised controlled trial (RCT); to explore clinician and patient willingness to participate in such a RCT; to develop consensus on eligibility criteria, surgical and best conservative care protocols; to examine possible outcome measures and estimate the sample size for a full RCT; and to develop trial procedures and estimate recruitment and follow-up rates. METHODS: Pre-pilot work: we surveyed all UK NHS hospital trusts (n = 197) to identify all FAI surgeons and to estimate how much arthroscopic FAI surgery they performed. We interviewed a purposive sample of 18 patients, 36 physiotherapists, 18 surgeons and two sports physicians to explore attitudes towards a RCT and used consensus-building methods among them to develop treatment protocols and patient information. Pilot RCT: we performed a pilot RCT in 10 hospital trusts. Patients were randomised to receive either hip arthroscopy or best conservative care and then followed up at 3, 6 and 12 months using patient-reported questionnaires for hip pain and function, activity level, quality of life, and a resource-use questionnaire. Qualitative recruitment intervention: we performed semistructured interviews with all researchers and clinicians involved in the pilot RCT in eight hospital trusts and recorded and analysed diagnostic and recruitment consultations with eligible patients. RESULTS: We identified 120 surgeons who reported treating at least 1908 patients with FAI by hip arthroscopy in the NHS in the financial year 2011/12. There were 34 hospital trusts that performed ≥ 20 arthroscopic FAI operations in the year. We found that clinicians were positive about a RCT: only half reported equipoise, but most said that they would be prepared to randomise patients. Patients strongly supported a RCT, but expressed concerns about its design; these were used to develop patient information for the pilot RCT. We developed a surgical protocol and showed that this could be used in a RCT. We developed a physiotherapy-led exercise-based package of best conservative care called 'personalised hip therapy' and showed that this was practicable. In the pilot RCT, we recruited 42 out of 60 eligible patients (70%) across nine sites. The mean duration and recruitment rate across all sites were 4.5 months and one patient per site per month, respectively. The lead site recruited for the longest period (9.3 months) and accrued the largest number of patients (2.1 patients per month). We recorded and analysed 84 diagnostic and recruitment consultations in 60 patients and used these to develop a model for an optimal recruitment consultation. We identified the International Hip Outcome Tool at 12 months as an appropriate outcome measure and estimated the sample size for a full trial as 344 participants: a number that could be recruited in 25 centres over 18 months. CONCLUSION: We have demonstrated that it is feasible to perform a RCT to establish the clinical effectiveness of hip arthroscopy compared with best conservative care for FAI. We have designed a full trial and developed and tested procedures for it, including an innovative approach to recruitment. We propose that a full trial be implemented

Sleep-wake sensitive mechanisms of adenosine release in the basal forebrain of rodents : an in vitro study

Adenosine acting in the basal forebrain is a key mediator of sleep homeostasis. Extracellular adenosine concentrations increase during wakefulness, especially during prolonged wakefulness and lead to increased sleep pressure and subsequent rebound sleep. The release of endogenous adenosine during the sleep-wake cycle has mainly been studied in vivo with microdialysis techniques. The biochemical changes that accompany sleep-wake status may be preserved in vitro. We have therefore used adenosine-sensitive biosensors in slices of the basal forebrain (BFB) to study both depolarization-evoked adenosine release and the steady state adenosine tone in rats, mice and hamsters. Adenosine release was evoked by high K+, AMPA, NMDA and mGlu receptor agonists, but not by other transmitters associated with wakefulness such as orexin, histamine or neurotensin. Evoked and basal adenosine release in the BFB in vitro exhibited three key features: the magnitude of each varied systematically with the diurnal time at which the animal was sacrificed; sleep deprivation prior to sacrifice greatly increased both evoked adenosine release and the basal tone; and the enhancement of evoked adenosine release and basal tone resulting from sleep deprivation was reversed by the inducible nitric oxide synthase (iNOS) inhibitor, 1400 W. These data indicate that characteristics of adenosine release recorded in the BFB in vitro reflect those that have been linked in vivo to the homeostatic control of sleep. Our results provide methodologically independent support for a key role for induction of iNOS as a trigger for enhanced adenosine release following sleep deprivation and suggest that this induction may constitute a biochemical memory of this state

Submillimeter Number Counts From Statistical Analysis of BLAST Maps

We describe the application of a statistical method to estimate submillimeter galaxy number counts from confusion limited observations by the Balloon-borne Large Aperture Submillimeter Telescope (BLAST). Our method is based on a maximum likelihood fit to the pixel histogram, sometimes called 'P(D)', an approach which has been used before to probe faint counts, the difference being that here we advocate its use even for sources with relatively high signal-to-noise ratios. This method has an advantage over standard techniques of source extraction in providing an unbiased estimate of the counts from the bright end down to flux densities well below the confusion limit. We specifically analyse BLAST observations of a roughly 10 sq. deg. map centered on the Great Observatories Origins Deep Survey South (GOODS-S) field. We provide estimates of number counts at the three BLAST wavelengths, 250, 350, and 500 microns; instead of counting sources in flux bins we estimate the counts at several flux density nodes connected with power-laws. We observe a generally very steep slope for the counts of about -3.7 at 250 microns and -4.5 at 350 and 500 microns, over the range ~0.02-0.5 Jy, breaking to a shallower slope below about 0.015 Jy at all three wavelengths. We also describe how to estimate the uncertainties and correlations in this method so that the results can be used for model-fitting. This method should be well-suited for analysis of data from the Herschel satellite.Comment: Accepted for publication in the Astrophysical Journal; see associated data and other papers at http://blastexperiment.info