Foci of segmentally contracted sarcomeres in trapezius muscle biopsy specimens in myalgic and nonmyalgic human subjects : preliminary results

Objective The myofascial trigger point hypothesis postulates that there are small foci of contracted sarcomeres in resting skeletal muscle. Only one example, in canine muscle, has been published previously. This study evaluated human muscle biopsies for foci of contracted sarcomeres. Setting The Departments of Rehabilitation Sciences and Physiotherapy at Ghent University, Ghent, Belgium. Subjects Biopsies from 28 women with or without trapezius myalgia were evaluated, 14 in each group. Methods Muscle biopsies were obtained from regions of taut bands in the trapezius muscle and processed for light and electron microscopy and for histochemical analysis. Examination of the biopsies was blinded as to group. Results A small number of foci of segmentally contracted sarcomeres were identified. One fusiform segmental locus involved the entire muscle fiber in tissue from a myalgic subject. Several transition zones from normal to contracted sarcomeres were found in both myalgic and nonmyalgic subjects. The distance between Z-lines in contracted sarcomeres was about 25–45% of the same distance in normal sarcomeres. Z-lines were disrupted and smeared in the contracted sarcomeres. Conclusions A small number of foci of segmentally contracted sarcomeres were found in relaxed trapezius muscle in human subjects, a confirmation of the only other example of spontaneous segmental contraction of sarcomeres (in a canine muscle specimen), consistent with the hypothesis of trigger point formation and with the presence of trigger point end plate noise

Intertwined magnetic and nematic orders in semiconducting KFe0.8_{0.8}Ag1.2_{1.2}Te2_2

Superconductivity in the iron pnictides emerges from metallic parent compounds exhibiting intertwined stripe-type magnetic order and nematic order, with itinerant electrons suggested to be essential for both. Here we use X-ray and neutron scattering to show that a similar intertwined state is realized in semiconducting KFe$_{0.8}$Ag$_{1.2}$Te$_2$ (K$_5$Fe$_4$Ag$_6$Te$_{10}$) without itinerant electrons. We find Fe atoms in KFe$_{0.8}$Ag$_{1.2}$Te$_2$ form isolated $2\times2$ blocks, separated by nonmagnetic Ag atoms. Long-range magnetic order sets in below $T_{\rm N}\approx35$ K, with magnetic moments within the $2\times2$ Fe blocks ordering into the stripe-type configuration. A nematic order accompanies the magnetic transition, manifest as a structural distortion that breaks the fourfold rotational symmetry of the lattice. The nematic orders in KFe$_{0.8}$Ag$_{1.2}$Te$_2$ and iron pnictide parent compounds are similar in magnitude and how they relate to the magnetic order, indicating a common origin. Since KFe$_{0.8}$Ag$_{1.2}$Te$_2$ is a semiconductor without itinerant electrons, this indicates that local-moment magnetic interactions are integral to its magnetic and nematic orders, and such interactions may play a key role in iron-based superconductivity.Comment: supplemental material available upon request, to be published in PR

The use of antidepressants in Belgian nursing homes : focus on indications and dosages in the PHEBE study

Background : Since antidepressants are prescribed for multiple indications, the use of an antidepressant cannot be equated with a diagnosis of depression. Objective : The objective of this study was to examine the quality of antidepressant prescribing in Belgian nursing homes, with a critical evaluation of indications and dosages, to see whether depression was appropriately treated in terms of drug choice, the indications for which antidepressants were being prescribed and whether there was underdosing. Methods : This analysis was based on data obtained in the Prescribing in Homes for the Elderly in Belgium (PHEBE) study, a cross-sectional, descriptive study of a representative, stratified, random sample of 1,730 residents from 76 Belgian nursing homes. The PHEBE study investigated overall drug utilization in Belgian nursing homes in 2006. Clinical and medication data for the present study were obtained from this study. A 28-item checklist of clinical conditions was designed ad hoc for the PHEBE study and sent to the residents' general practitioners (GPs) to collect clinical information. We copied the residents' medication charts, classified the drugs using the Anatomical Therapeutic Chemical (ATC) classification system codes and transferred the drug names and dosages into a database. Information on indications was retrospectively obtained from the GPs, so that we could link the indication to each medication. Minimum effective doses (MEDs) of antidepressants to treat major depression were obtained from the literature to assess underdosing. Results : The overall use of antidepressants in nursing homes was 39.5 % (95 % CI 37.2, 41.8). The physicians classified 34.2 % (95 % CI 32.0, 36.4) of the residents as having depression, and 80.9 To of these patients were treated with an antidepressant. Indications among the single antidepressant users (n = 551) were depression (66.2 %), insomnia (13.4 %), anxiety (6.2 %) and neuropathic pain (1.6 %). In the indication of depression, 74.8 % used a selective serotonin reuptake inhibitor (SSRI), predominantly citalopram, sertraline and escitalopram. Venlafaxine was used by 10.7 % of the residents. Dosages for these antidepressants were equal to or higher than the MED. But when trazodone, amitriptyline or mirtazapine were used to treat depression, respectively, 92.3, 55.5 and 44.5 % of prescribed dosages were below the MED. In the indication of insomnia, most of the time, trazodone (90.5 %) or mirtazapine (5.4 %) were used, and in lower dosages than those required for depression treatment (<MED). Tricyclic antidepressants were predominantly used for the treatment of neuropathic pain and were also used at lower dosages. Of all the residents receiving a medication for anxiety, only 13.9 % received an antidepressant (mostly an SSRI), and the remaining received a benzodiazepine. Conclusions : The number one indication for the use of an antidepressant was depression. Within this indication, mostly the recommended SSRIs were used, in dosages equal to or higher than the MED. Furthermore, we noticed that there was substantial use of sedative antidepressants for insomnia and that the physicians preferred to prescribe benzodiazepines over the recommended SSRIs to treat anxiety chronically

Benzodiazepine use in Belgian nursing homes: a closer look into indications and dosages

(1) To describe the prevalence of benzodiazepine use in Belgian nursing homes, with specific attention to indications and dosages. (2) To compare actual and recommended dosages of benzodiazepines for anxiety and insomnia. (3) To explore the risk profile for chronic benzodiazepine use in institutionalised older adults. Medication charts of 1,730 residents from 76 nursing homes in Belgium were collected and analysed, using the ATC classification. Drug name, indication and daily dosage were recorded. From authoritative international sources, we extracted for each drug and each indication a daily dosage recommended not to be exceeded in older adults for comparison with observed actual dosages. Among the chronic benzodiazepine or z-drug (BZD/Z) users (50% of the residents), the leading indication was 'insomnia' (59% of the users) followed by 'anxiety' (17%) and 'unrest' (10%). In the chronic prescriptions of BZD/Zs indicated for insomnia, the actual daily dose exceeded the geriatric upper limit in 95% of lormetazepam prescriptions, 82% of zolpidem, 78% of zopiclone and 35% of lorazepam prescriptions. For anxiety, daily doses also exceeded the limit but not to the same extent. Multivariate analysis showed BZD/Z use was positively associated with pain (OR 1.58, 95% CI 1.27-1.97), constipation (OR 1.43, 95% CI 1.16-1.76) and depression (OR 1.68, 95% CI 1.35-2.08). Residents with dementia were less likely to receive a BZD/Z (OR 0.60, 95% CI 0.48-0.74). Efforts to reduce the use of BZD/Zs in nursing homes should concentrate on insomnia, with interventions aimed at reducing too high prevalence of chronic use and too high daily dosages in this indication

Withdrawal versus continuation of long-term antipsychotic drug use for behavioural and psychological symptoms in older people with dementia

Background : Antipsychotic agents are often used to treat neuropsychiatric symptoms (NPS) in people with dementia although there is uncertainty about the effectiveness of their long-term use for this indication and concern that they may cause harm, including higher mortality. When behavioural strategies have failed and treatment with antipsychotic drugs is instituted, regular attempts to withdraw them have been recommended in guidelines. Physicians, nurses and families of older people with dementia may be reluctant to stop antipsychotics, fearing deterioration of NPS. This is an update of a Cochrane Review published in 2013. Objectives : To evaluate whether withdrawal of antipsychotic agents is successful in older people with dementia and NPS in primary care or nursing home settings, to list the different strategies for withdrawal of antipsychotic agents in older participants with dementia and NPS, and to measure the effects of withdrawal of antipsychotic agents on participants' behaviour and assess safety. Search methods : We searched the Specialized Register of the Cochrane Dementia and Cognitive Improvement Group (ALOIS), the Cochrane Library, MEDLINE, Embase, PsycINFO, CINAHL, LILACS, clinical trials registries and grey literature sources up to 11 January 2018. Selection criteria : We included all randomised, controlled trials comparing an antipsychotic withdrawal strategy to continuation of antipsychotics in people with dementia who had been treated with an antipsychotic drug for at least three months. Data collection and analysis : We used standard methodological procedures according to the Cochrane Handbook for Systematic Reviews of Interventions. We rated the quality of evidence for each outcome using the GRADE approach. Main results : We included 10 studies involving 632 participants. One new trial (19 participants) was added for this update. One trial was conducted in a community setting, eight in nursing homes and one in both settings. Different types of antipsychotics at varying doses were discontinued in the studies. Both abrupt and gradual withdrawal schedules were used. Reported data were predominantly from studies at low or unclear risk of bias. We included nine trials with 575 randomised participants that used a proxy outcome for overall success of antipsychotic withdrawal. Pooling data was not possible due to heterogeneity of outcome measures used. Based on assessment of seven studies, discontinuation may make little or no difference to whether or not participants complete the study (low-quality evidence). Two trials included only participants with psychosis, agitation or aggression who had responded to antipsychotic treatment. In these two trials, stopping antipsychotics was associated with a higher risk of leaving the study early due to symptomatic relapse or a shorter time to symptomatic relapse. We found low-quality evidence that discontinuation may make little or no difference to overall NPS, measured using various scales (7 trials, 519 participants). There was some evidence from subgroup analyses in two trials that discontinuation may reduce agitation for participants with less severe NPS at baseline, but may be associated with a worsening of NPS in participants with more severe NPS at baseline. None of the studies assessed withdrawal symptoms. Adverse effects of antipsychotics (such as falls) were not systematically assessed. Low-quality evidence showed that discontinuation may have little or no effect on adverse events (5 trials, 381 participants), quality of life (2 trials, 119 participants), or cognitive function (5 trials, 365 participants). There were insufficient data to determine whether discontinuation of antipsychotics has any effect on mortality (very low-quality evidence). Authors' conclusions : There is low-quality evidence that antipsychotics may be successfully discontinued in older people with dementia and NPS who have been taking antipsychotics for at least three months, and that discontinuation may have little or no important effect on behavioural and psychological symptoms. This is consistent with the observation that most behavioural complications of dementia are intermittent and often do not persist for longer than three months. Discontinuation may have little or no effect on overall cognitive function. Discontinuation may make no difference to adverse events and quality of life. Based on the trials in this review, we are uncertain whether discontinuation of antipsychotics leads to a decrease in mortality. People with psychosis, aggression or agitation who responded well to long-term antipsychotic drug use, or those with more severe NPS at baseline, may benefit behaviourally from continuation of antipsychotics. Discontinuation may reduce agitation for people with mild NPS at baseline. However, these conclusions are based on few studies or small subgroups and further evidence of benefits and harms associated with withdrawal of antipsychotic is required in people with dementia and mild and severe NPS. The overall conclusions of the review have not changed since 2013 and the number of available trials remains low

An ontology supported risk assessment approach for the intelligent configuration of supply networks

As progress towards globalisation continues, organisations seek ever better ways with which to configure and reconfigure their global production networks so as to better understand and be able to deal with risk. Such networks are complex arrangements of different organisations from potentially diverse and divergent domains and geographical locations. Moreover, greater focus is being put upon global production network systems and how these can be better coordinated, controlled and assessed for risk, so that they are flexible and competitive advantage can be gained from them within the market place. This paper puts forward a reference ontology to support risk assessment for product-service systems applied to the domain of global production networks. The aim behind this is to help accelerate the development of information systems by way of developing a common foundation to improve interoperability and the seamless exchange of information between systems and organisations. A formal common logic based approach has been used to develop the reference ontology, utilising end user information and knowledge from three separate industrial domains. Results are presented which illustrate the ability of the approach, together with areas for further work

On new developments in the physics of positron swarms

Recently a new wave of swarm studies of positrons was initiated based on more complete scattering cross section sets. Initially some interesting and new physics was discovered, most importantly negative differential conductivity (NDC) that occurs only for the bulk drift velocity while it does not exist for the flux property. However the ultimate goal was to develop tools to model positron transport in realistic applications and the work that is progressing along these lines is reviewed here. It includes studies of positron transport in molecular gases, thermalization in generic swarm situations and in realistic gas filled traps and transport of positrons in crossed electric and magnetic fields. Finally we have extended the same technique of simulation (Monte Carlo) to studies of thermalization of positronium molecule. In addition, recently published first steps towards including effects of dense media on positron transport are summarized here

The effect of massive binaries on stellar populations and supernova progenitors

We compare our latest single and binary stellar model results from the Cambridge STARS code to several sets of observations. We examine four stellar population ratios, the number of blue to red supergiants, the number of Wolf-Rayet stars to O supergiants, the number of red supergiants to Wolf-Rayet stars and the relative number of Wolf-Rayet subtypes, WC to WN stars. These four ratios provide a quantitative measure of nuclear burning lifetimes and the importance of mass loss during various stages of the stars' lifetimes. In addition we compare our models to the relative rate of type Ib/c to type II supernovae to measure the amount of mass lost over the entire lives of all stars. We find reasonable agreement between the observationally inferred values and our predicted values by mixing single and binary star populations. However there is evidence that extra mass loss is required to improve the agreement further, to reduce the number of red supergiants and increase the number of Wolf-Rayet stars.Comment: Accepted for publication in MNRAS, 11 pages, 10 figure