Aberrant intervertebral motion in patients with treatment‑resistant nonspecific low back pain: a retrospective cohort study and control comparison

Purpose Intervertebral kinematic assessments have been used to investigate mechanical causes when back pain is resistant to treatment, and recent studies have identified intervertebral motion markers that discriminate patients from controls. However, such patients are a heterogeneous group, some of whom have structural disruption, but the effects of this on intervertebral kinematics are unknown.Methods Thirty-seven patients with treatment-resistant back pain referred for quantitative fluoroscopy were matched to an equal number of pain-free controls for age and sex. All received passive recumbent flexion assessments for intervertebral motion sharing inequality (MSI), variability (MSV), laxity and translation. Comparisons were made between patient sub-groups, between patients and controls and against normative levels from a separate group of controls.Results Eleven patients had had surgical or interventional procedures, and ten had spondylolisthesis or pars defects. Sixteen had no disruption. Patients had significantly higher median MSI values (0.30) than controls (0.27, p = 0.010), but not MSV (patients 0.08 vs controls 0.08, p = 0.791). Patients who received invasive procedures had higher median MSI values (0.37) than those with bony defects (0.30, p = 0.018) or no disruption (0.28, p = 0.0007). Laxity and translation above reference limits were not more prevalent in patients.Conclusion Patients with treatment-resistant nonspecific back pain have greater MSI values than controls, especially if the former have received spinal surgery. However, excessive laxity, translation and MSV are not more prevalent in these patients. Thus, MSI should be investigated as a pain mechanism and for its possible value as a prognostic factor and/or target for treatment in larger patient populations

An Evaluation of passive recumbent quantitative fluoroscopy to measure mid-lumber intervertebral motion in patients with chronic non-specific low back pain and healthy volunteers.

Introduction: The biomechanical model of back pain has failed to find distinct relationships between intervertebral movement and pain due to limitations and variation in methods, and errors in measurement. Quantitative fluoroscopy (QF) reduces variation and error and measures dynamic intervertebral motion in vivo. This thesis used recumbent QF to examine continuous mid-lumbar intervertebral motion (L2 to L5) in patients with assumed mechanical chronic non-specific low back pain (CNSLBP) that had been clinically diagnosed. It aimed to develop kinematic parameters from the continuous data and determine whether these could detect subtle mechanical differences by comparing this to data obtained from healthy volunteers. Methods: This was a prospective cross sectional study. Forty patients with CNSLBP (age 21 to 51 years), and 40 healthy volunteers matched for gender, age and body mass index underwent passive recumbent QF in the coronal and sagittal planes. The patient group completed questionnaires for pain and disability. Four kinematic parameters were developed and compared for differences and diagnostic accuracy. Reference intervals were developed for three of the parameters and reproducibility of two were assessed. The radiation dose was compared to lumbar spine radiographs and diagnostic reference levels were established. Finally, relationships between patient’s pain and disability and one of the kinematic parameters (continuous proportional motion CPM) were explored. Results: Reproducibility was high. There were some differences in the coronal plane and flexion for each kinematic parameter, but no consistency across segments and none had high diagnostic accuracy. Radiation dose for QF is of the same magnitude as radiographs, and there were no associations between patient characteristics of pain and disability and CPM. Conclusion: Although the kinematic differences were weak, they indicate that biomechanics may be partly responsible for clinically diagnosed mechanical CNSLBP, but this is not detectable by any one kinematic parameter. It is likely that other factors such as loading, central sensitisation and motor control may also be responsible for back pain that is considered mechanical. QF is easily adapted to clinical practice and is recommended to replace functional radiography, but further work is needed to determine which kinematic parameters are clinically useful

Measurement of Intervertebral Motion Using Quantitative Fluoroscopy: Report of an International Forum and Proposal for Use in the Assessment of Degenerative Disc Disease in the Lumbar Spine

Quantitative fluoroscopy (QF) is an emerging technology for measuring intervertebral motion patterns to investigate problem back pain and degenerative disc disease. This International Forum was a networking event of three research groups (UK, US, Hong Kong), over three days in San Francisco in August 2009. Its aim was to reach a consensus on how best to record, analyse, and communicate QF information for research and clinical purposes. The Forum recommended that images should be acquired during regular trunk motion that is controlled for velocity and range, in order to minimise externally imposed variability as well as to correlate intervertebral motion with trunk motion. This should be done in both the recumbent passive and weight bearing active patient configurations. The main recommended outputs from QF were the true ranges of intervertebral rotation and translation, neutral zone laxity and the consistency of shape of the motion patterns. The main clinical research priority should initially be to investigate the possibility of mechanical subgroups of patients with chronic, nonspecific low back pain by comparing their intervertebral motion patterns with those of matched healthy controls

Repressive and non-repressive chromatin at native telomeres in Saccharomyces cerevisiae

<p>Abstract</p> <p>Background</p> <p>In <it>Saccharomyces cerevisiae </it>genes that are located close to a telomere can become transcriptionally repressed by an epigenetic process known as telomere position effect. There is large variation in the level of the telomere position effect among telomeres, with many native ends exhibiting little repression.</p> <p>Results</p> <p>Chromatin analysis, using microccocal nuclease and indirect end labelling, reveals distinct patterns for ends with different silencing states. Differences were observed in the promoter accessibility of a subtelomeric reporter gene and a characteristic array of phased nucleosomes was observed on the centromere proximal side of core X at a repressive end. The silent information regulator proteins 2 - 4, the yKu heterodimer and the subtelomeric core X element are all required for the maintenance of the chromatin structure of repressive ends. However, gene deletions of particular histone modification proteins can eliminate the silencing without the disruption of this chromatin structure.</p> <p>Conclusion</p> <p>Our data identifies chromatin features that correlate with the silencing state and indicate that an array of phased nucleosomes is not sufficient for full repression.</p

Proportional lumbar spine inter-vertebral motion patterns: a comparison of patients with chronic, non-specific low back pain and healthy controls

Introduction: Identifying biomechanical subgroups in chronic, non-specific low back pain (CNSLBP) populations from inter-vertebral displacements has proven elusive. Quantitative fluoroscopy (QF) has excellent repeatability and provides continuous standardised inter-vertebral kinematic data from fluoroscopic sequences allowing assessment of mid-range motion. The aim of this study was to determine whether proportional continuous IV rotational patterns were different in patients and controls. A secondary aim was to update the repeatability of QF measurement of range of motion (RoM) for inter-vertebral (IV) rotation

Using behavioural science to enhance use of core outcome sets in trials: protocol.

BackgroundCore outcome sets (COS) represent agreed-upon sets of outcomes, which are the minimum that should be measured and reported in all trials in specific health areas. Use of COS can reduce outcome heterogeneity, selective outcome reporting, and research waste, and can facilitate evidence syntheses. Despite benefits of using COS, current use of COS in trials is low. COS use can be understood as a behaviour, in that it is something trialists do, or not do, adequately. The aim of this study is to identify strategies, informed by behaviour change theory, to increase COS use in trials.MethodsThe project will be conducted in two stages, informed by the behaviour change wheel (BCW). The BCW is a theoretically based framework that can be used to classify, identify, and develop behaviour change strategies. In Stage 1, barriers and enablers to COS use will be extracted from published studies that examined trialist's use of COS. Barriers and facilitators will be mapped to the components of COM-B model (capability, opportunity, and motivation), which forms part of the BCW framework. Stage 2 will build on Stage 1 findings to identify and select intervention functions and behaviour change techniques to enhance COS use in trials.DiscussionThe findings of this study will provide an understanding of the behavioural factors that influence COS use in trials and what strategies might be used to target these factors to increase COS use in trials

The last animal: cosmopolitanism in The Last Man

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Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy