Increased SIRT3 combined with PARP inhibition rescues motor function of SBMA mice

Spinal and bulbar muscular atrophy (SBMA) is a neuromuscular disease with substantial mitochondrial and metabolic dysfunctions. SBMA is caused by polyglutamine (polyQ) expansion in the androgen receptor (AR). Activating or increasing the NAD+-dependent deacetylase, SIRT3, reduced oxidative stress and death of cells modeling SBMA. However, increasing diminished SIRT3 in AR100Q mice failed to reduce acetylation of the SIRT3 target/antioxidant, SOD2, and had no effect on increased total acetylated peptides in quadriceps. Yet, overexpressing SIRT3 resulted in a trend of motor recovery, and corrected TCA cycle activity by decreasing acetylation of SIRT3 target proteins. We sought to boost blunted SIRT3 activity by replenishing diminished NAD+ with PARP inhibition. Although NAD+ was not affected, overexpressing SIRT3 with PARP inhibition fully restored hexokinase activity, correcting the glycolytic pathway in AR100Q quadriceps, and rescued motor endurance of SBMA mice. These data demonstrate that targeting metabolic anomalies can restore motor function downstream of polyQ-expanded AR.

Autologous skin-derived neural precursor cell therapy reverses canine Alzheimer dementia-like syndrome in a proof of concept veterinary trial

BACKGROUND

Older companion dogs naturally develop a dementia-like syndrome with biological, clinical and therapeutic similarities to Alzheimer disease (AD). Given there has been no new safe, clinically effective and widely accessible treatment for AD for almost 20 years, an all-new cell therapeutic approach was trialled in canine veterinary patients, and further modelled in aged rats for more detailed neurobiological analysis.

METHODS

A Phase 1/2A veterinary trial was conducted in N = 6 older companion dogs with definitive diagnosis of Canine Cognitive Dysfunction (CCD). Treatment comprised direct microinjection of 250,000 autologous skin-derived neuroprecursors (SKNs) into the bilateral hippocampus using MRI-guided stereotaxis. Safety was assessed clinically and efficacy using the validated Canine Cognitive Dysfunction Rating Scale (CCDR) at baseline and 3-month post treatment. Intention to treat analysis imputed a single patient that had a surgical adverse event requiring euthanasia. Three dog brains were donated following natural death and histology carried out to quantify Alzheimer pathology as well as immature neurons and synapses; these were compared to a brain bank (N = 12) of untreated aged dogs with and without CCD. Further, an age-related memory dysfunction rat model (N = 16) was used to more closely evaluate intrahippocampal engraftment of canine SKN cells, focusing on mnemonic and synaptic effects as well as donor cell survival, neurodifferentation and electrophysiologic circuit integration in a live hippocampal slice preparation.

RESULTS

Four out-of-five dogs improved on the primary clinical CCDR endpoint, three fell below diagnostic threshold, and remarkably, two underwent full syndromal reversal lasting up to 2 years. At post mortem, synaptic density in the hippocampus specifically was nine standard deviations above non-treated dogs, and intensity of new neurons also several fold higher. There was no impact on AD pathology or long-term safety signals. Modelling in aged rats replicated the main canine trial findings: hippocampally-dependent place memory deficits were reversed and synaptic depletion rescued. In addition, this model confirmed donor cell survival and migration throughout the hippocampus, neuronal differentiation in situ, and physiologically-correct integration into pyramidal layer circuits.

CONCLUSIONS

With further development, SKN cell therapy may have potential for treating carefully chosen AD patients based on neurosynaptic restoration in the hippocampus.

Toward automatic beam angle selection for pencil-beam scanning proton liver Treatments: A deep learning-based approach

BACKGROUND

Dose deposition characteristics of proton radiation can be advantageous over photons. Proton treatment planning however poses additional challenges for the planners. Proton therapy is usually delivered with only a small number of beam angles, and the quality of a proton treatment plan is largely determined by the beam angles employed. Finding the optimal beam angles for a proton treatment plan requires time and experience, motivating the investigation of automatic beam angle selection methods.

PURPOSE

A deep learning-based approach to automatic beam angle selection is proposed for proton pencil-beam scanning treatment planning of liver lesions.

METHODS

We cast beam-angle selection as a multi-label classification problem. To account for angular boundary discontinuity, the underlying convolution neural network is trained with the proposed Circular Earth Mover's Distance based regularization and multi-label circular-smooth label technique. Furthermore, an analytical algorithm emulating proton treatment planners' clinical practice is employed in post-processing to improve the output of the model. Forty-nine patients that received proton liver treatments between 2017 and 2020 were randomly divided into training (n = 31), validation (n = 7), and test sets (n = 11). AI-selected beam angles were compared with those angles selected by human planners, and the dosimetric outcome was investigated by creating plans using knowledge-based treatment planning.

RESULTS

For 7 of the 11 cases in the test set, AI-selected beam angles agreed with those chosen by human planners to within 20 degrees (median angle difference = 10°; mean = 18.6°). Moreover, out of the total 22 beam angles predicted by the model, 15 (68%) were within 10 degrees of the human-selected angles. The high correlation in beam angles resulted in comparable dosimetric statistics between proton treatment plans generated using AI- and human-selected angles. For the cases with beam angle differences exceeding 20°, the dosimetric analysis showed similar plan quality although with different emphases on organ-at-risk sparing.

CONCLUSIONS

This pilot study demonstrated the feasibility of a novel deep learning-based beam angle selection technique. Testing on liver cancer patients showed that the resulting plans were clinically viable with comparable dosimetric quality to those using human-selected beam angles. In tandem with auto-contouring and knowledge-based treatment planning tools, the proposed model could represent a pathway for nearly fully automated treatment planning in proton therapy. This article is protected by copyright. All rights reserved.

Assessment of predictive indicators of acute gastrointestinal toxicity using in vivo transmission images

PURPOSE

For pelvic and abdominal treatments, excess dose to the bowel can result in acute toxicities. Current estimates of bowel toxicity are based on pre-treatment dose-volume histogram data. However, the actual dose the bowel receives depends on interfraction variations, such as patient anatomy changes. We propose a method to model bowel toxicities, incorporating in vivo patient information using transit electronic portal imaging device (EPID) images.

METHODS AND MATERIALS

For 63 patients treated to the lower thorax, abdomen, or pelvis on the Varian Halcyon, weekly chart review was performed to obtain incidences of grade 2 or higher toxicity, RTOG scale. Twenty patients presented with acute gastrointestinal (GI) toxicity. All patients were treated with conventional fractionation. For each treatment plan, the absolute volume dose-volume histogram of the bowel was exported and analyzed. Additionally, for each fraction of treatment, in vivo EPID images were collected and used to estimate the change in radiation transmission during the course of treatment. A logistic model was used to test correlations between acute GI toxicity and bowel dosimetric parameters as well as metrics obtained from in vivo image measurements. After performing the fit to the in vivo EPID data, the bootstrap resampling method was used to create confidence intervals. In vivo EPID image metrics from an additional 42 patients treated to the lower thorax, abdomen, or pelvis were used to validate the logistic model fit.

RESULTS

The incidence of toxicity versus the volume of 40 Gy to the bowel space was fitted with a logistic function, which was superior to an average model (p < 0.0001) and agrees with previously published models. For the initial in vivo EPID data, the incidence of toxicity versus the sum of in vivo transmission measurements showed marginal significance after 15 fractions (p = 0.10) of treatment and a significance of p = 0.038 is seen at the 20th fraction, when compared to an average model. For the validation data set, the logistic model of the in vivo transmission measurement after 20 fractions was superior to the average model (p = 0.043), with the model falling within the 68% confidence interval of the fit of the initial data set.

CONCLUSIONS

Dose-volume constraints to reduce the incidence of acute GI toxicity have been validated. The presented novel EPID transmission-based metric can be used to identify GI toxicity as patients progress through treatment.

457 The Effect of Biochemical Adversity of Primary Hyperparathyroidism on Preoperative Imaging (SPECT-CT and US Parathyroids)

Aim

Primary hyperparathyroidism (PHPT) is a common endocrine disorder, with an estimated incidence of 1/500 women and 1/2000 men older than 40 years. Several factors influence the positivity of preoperative scans including serum calcium, PTH and vitamin D levels, and gland size. The aim of our study is to examine the effect of biochemical adversity of primary hyperparathyroidism on preoperative imaging (SPECT-CT and US parathyroids).

Method

Retrospective study of 176 parathyroidectomies (2017-2020) in a tertiary referral centre with biochemistry, SPECT-CT, US parathyroids and histology outcomes being recorded. Failed parathyroidectomies were excluded.

Results

Patients were divided into 4 groups based on the preoperative calcium levels (normocalcemia &lt;2.6, 3.4%; mild 2.60-2.79, 51.1%; moderate 2.80-2.99, 31.2%; severe &gt;3.0 mmol/l, 14.2% of patients). Age (p-0.0297), preoperative vitamin D (p-0.03) and PTH levels (p-0.0001) were different while SPECT-CT positivity (p-0.29) weight of gland (p-0.015) and US positivity (p-0.09) were similar within the subgroups. Looking at the whole group, patients with positive SPECT-CT have a larger weight (p &lt; 0.0001) while preoperative PTH levels was higher for the positive SPECT-CT patients (p-0.0289). No relation was identified between calcium levels and SPECT-CT positivity (p-0.18). No significance between preoperative vitamin D and positivity of US and SPECT-CT within the study group were noted.

Conclusions

Serum PTH levels and weight of the gland are directly correlated with positivity of preoperative imaging. Preoperative calcium and vitamin D levels correlates indirectly with the severity of the disease but did not influence the preoperative imaging positivity.

Prospective Longitudinal Assessment of Health-related Quality of Life in Patients With Brain Metastases Undergoing Radiation Therapy

OBJECTIVE

We conducted a prospective clinical trial of patients receiving radiation (RT) for brain metastases to identify clinical predictors of pre-RT and post-RT health-related quality of life (hrQoL).

MATERIALS AND METHODS

Patients with brain metastases completed overall (European Organisation for Research and Treatment of Cancer QLQ C15-PAL) and brain tumor-specific (QLQ-BN20) hrQoL assessments pre-RT (n=127) and 1 (n=56) and 3 (n=45) months post-RT. Linear and proportional-odds models analyzed patient, disease, and treatment predictors of baseline, 1-, and 3-month hrQoL scores. Generalized estimating equations and repeated measures proportional-odds models assessed predictors of longitudinal hrQoL scores.

RESULTS

Most patients underwent stereotactic radiosurgery (SRS) (69.3%) and had non-small-cell lung (36.0%) metastases. Compared with SRS, receipt of whole brain RT was associated with a higher odds of appetite loss (baseline P=0.04, 1 mo P=0.02) and greater motor dysfunction (baseline P=0.01, 1 mo P=0.003, 3 mo P=0.02). Receipt of systemic therapy was associated with better emotional functioning after RT (1 mo P=0.03, 3 mo P=0.01). Compared with patients with breast cancer, patients with melanoma had higher odds of better global hrQoL (P=0.01) and less pain (P=0.048), while patients with lung cancer reported lower physical function (P=0.048) 3 months post-RT. Nonmarried patients had greater odds of higher global hrQoL (1 mo P=0.01), while male patients had lower odds of reporting more hair loss (baseline P=0.03, 3 mo P=0.045). Patients 60 years and above had lower odds of more drowsiness (P=0.04) and pain (P=0.049) over time.

CONCLUSIONS

Patients receiving SRS versus whole brain RT and systemic therapy reported better posttreatment hrQoL. In addition, melanoma metastases, nonmarried, male, and older patients with reported better hrQoL in various as well as domains after intracranial RT.

Cost Effectiveness of Watch and Wait Versus Resection in Rectal Cancer Patients with Complete Clinical Response to Neoadjuvant Chemoradiation

BACKGROUND

Watch and wait (WW) protocols have gained increasing popularity for patients diagnosed with locally advanced rectal cancer and presumed complete clinical response after neoadjuvant chemoradiation. While studies have demonstrated comparable survival and recurrence rates between WW and radical surgery, the decision to undergo surgery has significant effects on patient quality of life. We sought to conduct a cost-effectiveness analysis comparing WW with abdominoperineal resection (APR) and low anterior resection (LAR) among patients with stage II/III rectal cancer.

METHODS

In this comparative-effectiveness study, we built Markov microsimulation models to simulate disease progression, death, costs, and quality-adjusted life-years (QALYs) for WW or APR/LAR. We assessed cost effectiveness using the incremental cost-effectiveness ratio (ICER), with ICERs under $100,000/QALY considered cost effective. Probabilities of disease progression, death, and health utilities were extracted from published, peer-reviewed literature. We assessed costs from the payer perspective.

RESULTS

WW dominated both LAR and APR at a willingness to pay (WTP) threshold of $100,000. Our model was most sensitive to rates of distant recurrence and regrowth after WW. Probabilistic sensitivity analysis demonstrated that WW was the dominant strategy over both APR and LAR over 100% of iterations across a range of WTP thresholds from $0-250,000.

CONCLUSIONS

Our study suggests WW could reduce overall costs and increase effectiveness compared with either LAR or APR. Additional clinical research is needed to confirm the clinical efficacy and cost effectiveness of WW compared with surgery in rectal cancer.

Improving multilevel regression and poststratification with structured priors

A central theme in the field of survey statistics is estimating population-level quantities through data coming from potentially non-representative samples of the population. Multilevel regression and poststratification (MRP), a model-based approach, is gaining traction against the traditional weighted approach for survey estimates. MRP estimates are susceptible to bias if there is an underlying structure that the methodology does not capture. This work aims to provide a new framework for specifying structured prior distributions that lead to bias reduction in MRP estimates. We use simulation studies to explore the benefit of these prior distributions and demonstrate their efficacy on non-representative US survey data. We show that structured prior distributions offer absolute bias reduction and variance reduction for posterior MRP estimates in a large variety of data regimes.

Correlation between biochemical features and outcomes of preoperative imaging (SPECT-CT and Ultrasound) in primary hyperparathyroidism

BACKGROUND

Primary hyperparathyroidism is the third most common endocrine disorder, diagnosed by elevated parathyroid hormone (PTH) in hypercalcaemia. Several biochemical factors have been described to suggest severity of disease and may be correlated with preoperative imaging.

METHODS

This was a retrospective study of patients who underwent parathyroidectomy over a 3-year period. Preoperative calcium, PTH, vitamin D levels, ALP (alkaline phosphatase), vitamin D, serum phosphate and US and SPECT-CT positivity was noted.

RESULTS

176 patients underwent parathyroidectomy and these were divided into 4 groups based on preoperative calcium. Overall, 61% of patients showed concordance between imaging and operative findings. Severe hypercalcaemia was associated with higher PTH levels, lower vitamin D levels, an increased rate of abnormal ALP levels, lower phosphate, male gender and highest rate of imaging concordance. Imaging positivity was associated with severe hypercalcaemia and elevated PTH levels. Level of PTH >125 pmol/L and hypercalcaemia >2.8 mmol/L are the most accurate cut-off levels for scan positivity.

CONCLUSION

Biochemical factors associated with severity of the disease are directly correlated with positivity of preoperative imaging while ALP and vitamin D did not influence the preoperative imaging positivity but are associated with disease adversity. Serum phosphate level independently predicted results of parathyroid US.

An unusual presentation of dysarthria in a young patient, a stroke mimic

Internal carotid artery dissection commonly affects younger patients. We present a case of a previously fit and well 43-year-old gentleman who presented with a sudden onset of slurring of speech, with right-sided tongue deviation and fasciculation on examination. Signs and symptoms began following participation in a home workout class. Magnetic resonance angiography revealed right-sided extracrainal internal carotid artery dissection leading to right-sided unilateral twelfth cranial nerve palsy.

Intrafractional relationship changes between an external breathing signal and fiducial marker positions in pancreatic cancer patients

Background and purpose

The purpose of this study of pancreatic cancer patients treated with respiratory‐guided stereotactic body radiotherapy (SBRT) on a standard linac was to investigate (a) the intrafractional relationship change (IRC) between a breathing signal and the tumor position, (b) the impact of IRC on the delivered dose, and (c) potential IRC predictors.

Materials and methods

We retrospectively investigated 10 pancreatic cancer patients with 2–4 implanted fiducial markers in the tumor treated with SBRT. Fluoroscopic images were acquired before and after treatment delivery simultaneously with the abdominal breathing motion. We quantified the IRC as the change in fiducial location for a given breathing amplitude in the left–right (LR), anterior–posterior (AP), and superior–inferior (SI) directions from before to after treatment delivery. The treatment plans were re‐calculated after changing the isocenter coordinates according to the IRCs. Four treatment‐ or patient‐related factors were investigated as potential predictors for IRC using linear models.

Results

The average (±1 SD) absolute IRCs in the LR, AP, and SI directions were 1.2 ± 1.2 mm, 0.7 ± 0.7 mm, and 1.1 ± 0.8 mm, respectively. The average 3D IRC was 2.0 ± 1.3 mm (range: 0.4–5.3 mm) for a median treatment delivery time of 8.5 min (range: 5.7–19.9 min; n = 31 fractions). The dose coverage of the internal target volume (ITV) decreased by more than 3% points in three of 31 fractions. In those cases, the 3D IRC had been larger than 4.3 mm. The 3D IRC was found to correlate with changes in the minimum breathing amplitude during treatment delivery.

Conclusion

On average, 2 mm of treatment delivery accuracy was lost due to IRC. Periodical intrafractional imaging is needed to safely deliver respiratory‐guided SBRT.

The Mitochondrial Apoptotic Effectors BAX/BAK Activate Caspase-3 and -7 to Trigger NLRP3 Inflammasome and Caspase-8 Driven IL-1β Activation

Intrinsic apoptosis resulting from BAX/BAK-mediated mitochondrial membrane damage is regarded as immunologically silent. We show here that in macrophages, BAX/BAK activation results in inhibitor of apoptosis (IAP) protein degradation to promote caspase-8-mediated activation of IL-1β. Furthermore, BAX/BAK signaling induces a parallel pathway to NLRP3 inflammasome-mediated caspase-1-dependent IL-1β maturation that requires potassium efflux. Remarkably, following BAX/BAK activation, the apoptotic executioner caspases, caspase-3 and -7, act upstream of both caspase-8 and NLRP3-induced IL-1β maturation and secretion. Conversely, the pyroptotic cell death effectors gasdermin D and gasdermin E are not essential for BAX/BAK-induced IL-1β release. These findings highlight that innate immune cells undergoing BAX/BAK-mediated apoptosis have the capacity to generate pro-inflammatory signals and provide an explanation as to why IL-1β activation is often associated with cellular stress, such as during chemotherapy.

Quantitative Imaging Biomarkers of Damage to Critical Memory Regions Are Associated With Post-Radiation Therapy Memory Performance in Brain Tumor Patients

PURPOSE

We used quantitative magnetic resonance imaging to prospectively analyze the association between microstructural damage to memory-associated structures within the medial temporal lobe and longitudinal memory performance after brain radiation therapy (RT).

METHODS AND MATERIALS

Patients with a primary brain tumor receiving fractionated brain RT were enrolled on a prospective trial (n = 27). Patients underwent high-resolution volumetric brain magnetic resonance imaging, diffusion-weighted imaging, and neurocognitive testing before and 3, 6, and 12 months post-RT. Medial temporal lobe regions (hippocampus; entorhinal, parahippocampal, and temporal pole white matter [WM]) were autosegmented, quantifying volume and diffusion biomarkers of WM integrity (mean diffusivity [MD]; fractional anisotropy [FA]). Reliable change indices measured changes in verbal (Hopkins Verbal Learning Test-Revised) and visuospatial (Brief Visuospatial Memory Test-Revised [BVMT-R]) memory. Linear mixed-effects models assessed longitudinal associations between imaging parameters and memory.

RESULTS

Visuospatial memory significantly declined at 6 months post-RT (mean reliable change indices, -1.3; P = .012). Concurrent chemotherapy and seizures trended toward a significant association with greater decline in visuospatial memory (P = .053 and P = .054, respectively). Higher mean dose to the left temporal pole WM was significantly associated with decreased FA (r = -0.667; P = .002). Over all time points, smaller right hippocampal volume (P = .021), lower right entorhinal FA (P = .023), greater right entorhinal MD (P = .047), and greater temporal pole MD (BVMT-R total recall, P = .003; BVMT-R delayed recall, P = .042) were associated with worse visuospatial memory. The interaction between right entorhinal MD (BVMT-R total recall, P = .021; BVMT-R delayed recall, P = .004) and temporal pole FA (BVMT-R delayed recall, P = .024) significantly predicted visuospatial memory performance.

CONCLUSIONS

Brain tumor patients exhibited visuospatial memory decline post-RT. Microstructural damage to critical memory regions, including the hippocampus and medial temporal lobe WM, were associated with post-RT memory decline. The integrity of medial temporal lobe structures is critical to memory performance post-RT, representing possible avoidance targets for memory preservation.

Unilateral Strength Training and Mirror Therapy in Patients With Chronic Stroke: A Pilot Randomized Trial

OBJECTIVE

The aim of the study was to investigate the feasibility and potential effectiveness of mirror-aided cross-education compared with cross-education alone in poststroke upper limb recovery.

DESIGN

A pilot randomized controlled parallel group study was carried out. Thirty-two patients with chronic stroke followed a 4-wk isometric strength training program performed with the less-affected upper limb three times per week. Participants in the mirror and strength training group observed the reflection of the exercising arm in the mirror. Participants in the strength training only group exercised without a mirror entirely. Participant compliance, adverse effects, and suitability of outcome measures assessed feasibility. Effectiveness outcomes included maximal isometric strength measured with the Biodex Dynamometer, the Modified Ashworth Scale, and the Chedoke Arm and Hand Activity Inventory.

RESULTS

Compliance was high with no adverse effects. The use of the Biodex Dynamometer must be reviewed. Mirror therapy did not augment the cross-education effect (P > 0.05) in patients with chronic stroke when training isometrically.

CONCLUSIONS

This pilot trial established the feasibility of a randomized controlled trial comparing mirror-aided cross-education with cross-education alone for poststroke upper limb recovery. Mirror therapy did not augment cross-education when training isometrically. However, results indicate that the combination of interventions should be investigated further applying an altered training protocol.

Unilateral dorsiflexor strengthening with mirror therapy to improve motor function after stroke: A pilot randomized study

BACKGROUND

Independently, cross-education, the performance improvement of the untrained limb following unilateral training, and mirror therapy have shown to improve lower limb functioning poststroke. Mirror therapy has shown to augment the cross-education effect in healthy populations. However, this concept has not yet been explored in a clinical setting.

OBJECTIVES

This study set out to investigate the feasibility and potential efficacy of applying cross-education combined with mirror therapy compared with cross-education alone for lower limb recovery poststroke.

METHODS

Thirty-one chronic stroke participants (age 61.7 ± 13.3) completed either a unilateral strength training (ST; n = 15) or unilateral strength training with mirror-therapy (MST; n = 16) intervention. Both groups isometrically strength trained the less-affected ankle dorsiflexors three times per week for 4 weeks. Only the MST group observed the mirror reflection of the training limb. Patient eligibility, compliance, treatment reliability, and outcome measures were assessed for feasibility. Maximal voluntary contraction (MVC; peak torque, rate of torque development, and average torque), 10-m walk test, timed up and go (TUG), Modified Ashworth Scale (MAS), and the London Handicap Scale (LHS) were assessed at pretraining and posttraining.

RESULTS

Treatment and assessments were well tolerated without adverse effects. No between group differences were identified for improvement in MVC, MAS, TUG, or LHS. Only the combined treatment was associated with functional improvements with the MST group showing an increase in walking velocity.

CONCLUSION

Cross-education plus mirror therapy may have potential for improving motor function after stroke. This study demonstrates the feasibility of the combination treatment and the need for future studies with larger sample sizes to investigate the effectiveness of the treatment.

Peak torque, rate of torque development and average torque of isometric ankle and elbow contractions show excellent test-retest reliability

Background

Peak Torque (PT), Rate of Torque Development (RTD) and Average Torque (AT) over a single contraction assess the three components of muscle function during isometric contractions. Surprisingly, AT has never been reported or its reliability confirmed.

Objectives

This study aims to establish protocol reliability for ankle dorsiflexion and elbow extension isometric muscle function (PT, RTD, AT) in healthy participants using the Biodex System 3 Dynamometer.

Methods

Twelve participants (6 male, 6 female, mean age 39 . 8 ± 16 . 0 years) performed four maximal isometric contractions on two occasions. Intraclass Correlation Coefficient (ICC), Typical Error (TE) and Coefficient of Variation (CV) for PT, RTD and AT were reported.

Results

The ICC for all strength parameters varied from 0.98-0.92. TE for ankle dorsiflexion PT was 1.38 Nm, RTD 7.43 Nm/s and AT 1.33 Nm, CV varied from 6 . 26 ± 6 . 25 % to 11 . 72 ± 8 . 27 % . For elbow extension, TE was 3.36 Nm for PT, 14.87 Nm/s for RTD and 3.03 Nm for AT, CV varied from 5 . 97 ± 4 . 52 % to 18 . 46 ± 14 . 78 % .

Conclusion

Maximal isometric ankle dorsiflexion and elbow extension PT, RTD and AT can be evaluated with excellent reliability when following the described protocol. This testing procedure, including the application of AT, can be confidently applied in research, exercise or clinical settings.

Mapping the contact area of the patellofemoral joint: the relationship between stability and joint congruence

AIMS

The aim of this study was to determine and compare the congruency of the articular surface contact area of the patellofemoral joint (PFJ) during both active and passive movement of the knee with the use of an MRI mapping technique in both the stable and unstable PFJ.

PATIENTS AND METHODS

A prospective case-control MRI imaging study of patients with a history of PFJ instability and a control group of volunteers without knee symptoms was performed. The PFJs were imaged with the use of an MRI scan during both passive and active movement from 0° through to 40° of flexion. The congruency through measurement of the contact surface area was mapped in 5-mm intervals on axial slices. In all, 40 patients were studied. The case group included 31 patients with symptomatic patellofemoral instability and the control group of nine asymptomatic volunteers. The ages were well matched between the case and control groups. The mean age was 25 years (16 to 42; sd 6.9) in the case group and 26 years (19 to 32; sd 5.1) in the control group. There were 19 female and 12 male patients in the case group.

RESULTS

The unstable PFJs were demonstrably less congruent than the stable PFJs throughout the range of knee movement. The greatest mean differences in congruency between unstable and stable PFJ's were observed between 11° and 20° flexion (1.73 cm² vs 4.00 cm²; p < 0.005).

CONCLUSION

The unstable PFJ is less congruent than the stable PFJ throughout the range of knee movement studied. This approach to mapping PFJ congruency produces a measurable outcome and will allow the assessment of pre- and postoperative results following surgical intervention. This may facilitate the design of new procedures for patients with PFJ instability. If a single axial series is to be obtained on MRI scan, the authors recommend 11° to 20° of tibiofemoral flexion, as this was shown to have the greatest difference in contact surface area between the case and control groups. Cite this article: Bone Joint J 2019;101-B:552-558.

Mirror therapy and treadmill training for patients with chronic stroke: a pilot randomized controlled trial

BACKGROUND

Previous lower-limb mirror therapy research has focused on non-weight bearing interventions.

OBJECTIVES

The primary aim of this study was to investigate the effect and feasibility of a combination of mirror therapy and treadmill training on post-stroke lower-limb recovery compared to a placebo intervention.

METHODS

All patients (N = 30) walked on a treadmill for 30 min per day, 3 days per week, for 4 weeks. The mirror therapy and treadmill training group (n = 15) walked on the treadmill while viewing a reflection of their non-paretic limb in a mirror positioned in their mid-sagittal plane. The placebo group (n = 15) received no mirror visual feedback due to an altered mirror position.

PRIMARY OUTCOME MEASURES

Ten Metre Walk Test (10MWT) and Six Minute Walk Test (6MWT).

SECONDARY OUTCOME MEASURES

Modified Ashworth Scale (MAS) and Fugl-Meyer Assessment-Lower Extremity (FMA-LE). Feasibility was appraised by examining participant compliance and any adverse events.

RESULTS

No significant between group differences were demonstrated for the 10MWT, 6MWT or FMA-LE at post-training or 3-month follow-up assessment. A significant between group difference on the MAS was demonstrated in the reduction of ankle dorsiflexion muscle tone (p = 0.006) and ankle plantarflexion muscle tone (p = 0.01) in the mirror therapy group compared to the placebo group at post-training assessment but not at 3-month follow-up.

CONCLUSION

Our study reveals that in our group of patients with chronic stroke, mirror therapy combined with treadmill training facilitated significant reductions in ankle muscle tone (p < 0.05) compared to a placebo intervention.

Data Integration for the Assessment of Population Exposure to Ambient Air Pollution for Global Burden of Disease Assessment

Air pollution is a leading global disease risk factor. Tracking progress (e.g., for Sustainable Development Goals) requires accurate, spatially resolved, routinely updated exposure estimates. A Bayesian hierarchical model was developed to estimate annual average fine particle (PM_2.5) concentrations at 0.1° × 0.1° spatial resolution globally for 2010-2016. The model incorporated spatially varying relationships between 6003 ground measurements from 117 countries, satellite-based estimates, and other predictors. Model coefficients indicated larger contributions from satellite-based estimates in countries with low monitor density. Within and out-of-sample cross-validation indicated improved predictions of ground measurements compared to previous (Global Burden of Disease 2013) estimates (increased within-sample R² from 0.64 to 0.91, reduced out-of-sample, global population-weighted root mean squared error from 23 μg/m³ to 12 μg/m³). In 2016, 95% of the world's population lived in areas where ambient PM_2.5 levels exceeded the World Health Organization 10 μg/m³ (annual average) guideline; 58% resided in areas above the 35 μg/m³ Interim Target-1. Global population-weighted PM_2.5 concentrations were 18% higher in 2016 (51.1 μg/m³) than in 2010 (43.2 μg/m³), reflecting in particular increases in populous South Asian countries and from Saharan dust transported to West Africa. Concentrations in China were high (2016 population-weighted mean: 56.4 μg/m³) but stable during this period.

Mirror therapy for improving lower limb motor function and mobility after stroke: A systematic review and meta-analysis

BACKGROUND

Mirror therapy has been proposed as an effective intervention for lower limb rehabilitation post stroke.

RESEARCH QUESTION

This systematic review with meta-analysis examined if lower limb mirror therapy improved the primary outcome measures of muscle tone and motor function and the secondary outcome measures balance characteristics, functional ambulation, walking velocity, passive range of motion (PROM) for ankle dorsiflexion and gait characteristics in patients with stroke compared to other interventions.

METHODS

Standardised mean differences (SMD) and mean differences (MD) were used to assess the effect of mirror therapy on lower limb functioning.

RESULTS

Nine studies were included in the review. Among the primary outcome measures there was evidence of a significant effect of mirror therapy on motor function compared with sham and non-sham interventions (SMD 0.54; 95% CI 0.24-0.93). Furthermore, among the secondary outcome measures there was evidence of a significant effect of mirror therapy for balance capacity (SMD -0.55; 95% CI -1.01 to -0.10), walking velocity (SMD 0.71; 95% CI 0.35-1.07), PROM for ankle dorsiflexion (SMD 1.20; 95% CI 0.71-1.69) and step length (SMD 0.56; 95% CI -0.00 to 1.12).

SIGNIFICANCE

The results indicate that using mirror therapy for the treatment of certain lower limb deficits in patients with stroke may have a positive effect. Although results are somewhat positive, overly favourable interpretation is cautioned due to methodological issues concerning included studies.

An intuitive Bayesian spatial model for disease mapping that accounts for scaling

In recent years, disease mapping studies have become a routine application within geographical epidemiology and are typically analysed within a Bayesian hierarchical model formulation. A variety of model formulations for the latent level have been proposed but all come with inherent issues. In the classical BYM (Besag, York and Mollié) model, the spatially structured component cannot be seen independently from the unstructured component. This makes prior definitions for the hyperparameters of the two random effects challenging. There are alternative model formulations that address this confounding; however, the issue on how to choose interpretable hyperpriors is still unsolved. Here, we discuss a recently proposed parameterisation of the BYM model that leads to improved parameter control as the hyperparameters can be seen independently from each other. Furthermore, the need for a scaled spatial component is addressed, which facilitates assignment of interpretable hyperpriors and make these transferable between spatial applications with different graph structures. The hyperparameters themselves are used to define flexible extensions of simple base models. Consequently, penalised complexity priors for these parameters can be derived based on the information-theoretic distance from the flexible model to the base model, giving priors with clear interpretation. We provide implementation details for the new model formulation which preserve sparsity properties, and we investigate systematically the model performance and compare it to existing parameterisations. Through a simulation study, we show that the new model performs well, both showing good learning abilities and good shrinkage behaviour. In terms of model choice criteria, the proposed model performs at least equally well as existing parameterisations, but only the new formulation offers parameters that are interpretable and hyperpriors that have a clear meaning.

Mirror therapy and treadmill training for a patient with chronic stroke: A case report

INTRODUCTION

A large proportion of patients with chronic stroke have permanent lower limb functional disability leading to reduced levels of independent mobility. Individually, both mirror therapy and treadmill training have been shown to improve aspects of lower limb functioning in patients with stroke. This case report examined whether a new combination of both interventions would lead to improvements in lower limb functional disability for a patient with chronic stroke.

CASE DESCRIPTION

The participant was a 50-year-old female who had a left middle cerebral artery infarction (47 months' post stroke). Due to hemiparesis, she had lower limb motor impairment and gait deficits.

INTERVENTION

The participant engaged in a combination of mirror therapy and treadmill training for 30 minutes per day, 3 days per week, for 4 weeks.

OUTCOMES

Modified Ashworth Scale, Fugl-Meyer Assessment-Lower Extremity and the 10 m Walk Test demonstrated clinically meaningful change. The 6 Minute Walk Test did not demonstrate meaningful change.

DISCUSSION

The positive outcomes from this new combination therapy for this participant are encouraging given the relatively small dose of training and indicate the potential benefit of mirror therapy as an adjunct to treadmill training for enhancing lower limb muscle tone, motor function and walking velocity in patients with chronic stroke.

Pancarpal Arthrodesis in a Cat: A Case Report and Anatomical Study

A carpometacarpal hyperextension injury in a cat was treated by pancarpal arthrodesis, following the failure of conservative treatment. An 8-hole 1.5 mm mini plate was placed on the dorsal aspect of the distal radius, carpus and third metacarpal bone. An aluminium spoon splint was used for six weeks postoperatively, until radio-graphs revealed bone union. The body weights and the dimensions of the distal radius, radiocarpal bone and third metacarpal bone from the left limb of 15 cadavers were recorded in order to aid the selection of appropriate implants for future cases.

Pancarpal arthrodesis was used to treat a cat with a carpometacarpal hyperextension injury. The use of an 8-hole 1.5 mm mini plate applied to the dorsal surface of the carpus, in combination with limb splinting provided effective stabilization. An excellent functional result was obtained. Measurements of the radius, radial carpal and third metacarpal bones from 15 cadavers suggest that 1.5 mm bone screws are the largest that should be used for carpal arthrodesis in the average sized cat.

Automatic patient positioning and gating window settings in respiratory-gated stereotactic body radiation therapy for pancreatic cancer using fluoroscopic imaging

Before treatment delivery of respiratory-gated radiation therapy (RT) in patients with implanted fiducials, both the patient position and the gating window thresholds must be set. In linac-based RT, this is currently done manually and setup accuracy will therefore be dependent on the skill of the user. In this study, we present an automatic method for finding the patient position and the gating window thresholds. Our method uses sequentially acquired anterior-posterior (AP) and lateral fluoroscopic imaging with simultaneous breathing amplitude monitoring and intends to reach 100% gating accuracy while keeping the duty cycle as high as possible. We retrospectively compared clinically used setups to the automatic setups by our method in five pancreatic cancer patients treated with hypofractionated RT. In 15 investigated fractions, the average (±standard deviation) differences between the clinical and automatic setups were -0.4 ± 0.8 mm, -1.0 ± 1.1 mm, and 1.8 ± 1.3 mm in the left-right (LR), the AP, and the superior-inferior (SI) direction, respectively. For the clinical setups, typical interfractional setup variations were 1-2 mm in the LR and AP directions, and 2-3 mm in the SI direction. Using the automatic method, the duty cycle could be improved in six fractions, in four fractions the duty cycle had to be lowered to improve gating accuracy, and in five fractions both duty cycle and gating accuracy could be improved. Our automatic method has the potential to increase accuracy and decrease user dependence of setup for patients with implanted fiducials treated with respiratory-gated RT. After fluoroscopic image acquisition, the calculated patient shifts and gating window thresholds are calculated in 1-2 s. The method gives the user the possibility to evaluate the effect of different patient positions and gating window thresholds on gating accuracy and duty cycle. If deemed necessary, it can be used at any time during treatment delivery.