Search

Introduction: This cadaveric study describes the collateral ligament constraints on the feline tarsocrural joint using stress radiography. Methods: Thirty‐six feline cadaveric hindlimbs free of orthopaedic disease were placed in a custom‐made jig and controlled stress radiography was performed before and after transection of one, or both collateral ligaments. Changes in varus and valgus deviation and pronation and supination were measured at three limb angles (extension, 120o flexion and 90o flexion). Results: There was a significant positive percentage change in the mean angle of varus deviation after transection of the fibulocalcaneal ligament at all limb positions (extension: 41%, 120°: 78%, 90°: 63%). There was a significant positive percentage change in the mean angle of varus deviation after transection of the fibulotalar ligament at extension (14%). There was a significant positive percentage change in the mean angle of varus deviation after transection of both fibulocalcaneal and fibulotalar ligaments at all limb positions (extension: 58%, 120°: 67%, 90°: 67%), and in the mean angle of valgus deviation (100%) and supination (89%) at 90 degrees flexion. There was a significant positive percentage change in the mean angle of valgus deviation after transection of the tibiocentral ligament at all limb positions (extension: mean 79%, 120°: 43%, 90°: 49%) and the mean angle of pronation at 120 degrees flexion (10%). There was a significant positive percentage change in the mean angle of varus deviation after transection of the tibiotalar ligament at extension (11%) and at 90 degrees flexion (54%) and in the mean angle of pronation at all limb positions (extension: 11%, 120°: 19%, 90°: 32%). There was a significant positive percentage change in the mean angle of valgus deviation (extension: 255%, 120°: 172%, 90°: 176%) and pronation (extension: 58%, 120°: 134%, 90°: 76%) after transection of the tibiocentral and tibiotalar ligaments at all limb positions and in the mean angle of varus deviation at extension (13%) and 90 degrees flexion (69%). Conclusion: The medial collateral ligaments prevent against excessive valgus deviation and pronation, and the lateral collateral ligaments prevent against excessive varus deviation and supination. At 90 degrees flexion subluxation of the talus occurs on the ipsilateral side of the ligament injury resulting in an additional direction of instability. [ABSTRACT FROM AUTHOR]

School-based, activity-focused physical education (PE) may be an effective, evidence-based method for reducing childhood overweight and obesity. However, it has been found that learners do not engage in vigorous activity during PE classes and spend the majority of class time standing while roll is taken or awaiting their turn to play. This study determined the effect of a 12-week concurrent physical education and obesity-prevention training programme (CON) on the anthropometry and cardiorespiratory measures in children already at the upper limit (50th centile) of a healthy body mass index (BMI). Anthropometric measures included body mass, stature, body mass index (BMI), body fat percentage while maximal cardiorespiratory fitness (VO2max) was measured using the one-mile walk test. CON performed a 10-minute warm-up, followed by 40 minutes of strength and endurance training using dumbbells, medicine balls and gym ball exercises, free hand exercises using callisthenic exercises and agility and flexibility exercises using ladder and gym ball exercises and concluded each session with 10 minutes of stretching. Analysis of variance (ANOVA) with repeated measures was used to determine the differences in anthropometric and cardiorespiratory variables over time between groups. A separate ANOVA with repeated measures for each group was used to determine differences over time in each group. One-way ANOVA was performed to determine the significance of differences between groups. When significance was revealed, a post-hoc test (Tukey HSD) was used to determine the differences between specific means. In the CON, there were no significant (p ≤ 0.01) differences in body mass, body fat percentage and maximal oxygen consumption (VO2max). However, a deleterious, significant increase was found in BMI at post-test when compared to pre-test (p = 0.001). In the PEG, there was no significant difference in body fat percentage (p = 0.108) and VO2max (p = 0.103), and the PEG too demonstrated significant increase in BMI (p = 0.008) and body mass (p = 0.002) from pre- to post-test. These findings indicate that a 12-week callisthenic programme in addition to physical education classes was not more effective than physical education classes alone. As such, more comprehensive programmes that include other treatments such as nutritional and/or behavioural modifications may be needed to curb childhood overweight and obesity. [ABSTRACT FROM AUTHOR]

Purpose. The objectives of this study were to describe perceptions of disability among South Asian immigrant mothers of children with disabilities in a large multicultural urban centre in Ontario, Canada, and to explore how these perceptions influence rehabilitation services. The study was built on our previous work conducted with mothers in South Asia. Methods. A descriptive qualitative research design was employed. Semi-structured interviews were conducted with five mothers who had immigrated to Canada from South Asia in the last decade, and whose children were receiving outpatient rehabilitation services. Results. Three primary themes were identified: (1) perceptions of disability reflected a mix of traditional and western beliefs; (2) mothers experienced physical, emotional and social suffering related to socio-cultural and material barriers and (3) mothers' primary goal for their children was the achievement of independent walking, which was linked to notions of achieving a ''normal'' life and the desire for more rehabilitation interventions. Conclusions. South Asian immigrant mothers' perceptions of their children's disabilities had important similarities and differences to mothers living in South Asia. Healthcare professionals can assist families in managing and coping with their child's disabilities by exploring their unique values and beliefs and identifying achievable outcomes together. [ABSTRACT FROM AUTHOR]

An abstract of the conference paper "Report of a case of right ductus arteriosus in a fetus with right aortic arch" by X. Zhang and colleagues is presented.

An abstract of the conference paper "Ultrasound features of an anomaly of the umbilico-portal system-a case report," by T. Foo, and colleagues is presented.

Online adaptive radiotherapy has been clinically feasible through decades of research and development and is now available in the clinical routine with dedicated platforms using CBCT-LINAC or MR-LINAC. The quality assurance (QA) of online plans has become a bottleneck in the clinical workflow as it often requires manual data export/import through third party software, lengthy wait for the secondary dose calculation, and tedious work on report generation and checking, etc. The QA bottleneck not only impedes clinical workflow but also risks plan and treatment quality due to the time pressure with the patient waiting on the treatment table. We have developed and implemented in-house solutions to address such a bottleneck. We developed dedicated in-house infrastructure to facilitate online adaptive plan QA and clinical workflow: 1) RT-PACK with SQLite database, which receives and organizes DICOM-RT data from any DICOM sender (e.g., clinical TPS); 2) a general purpose dose calculation server powered by the in-house GPU-based Monte Carlo particle transport engine with electromagnetic field modelling; 3) a report generator that automatically generates reports for secondary dose and plan quality check; 4) a web-portal that allows clinicians to review and sign the report anywhere with a network and VPN connection, even from a mobile phone. The reports and related documents will be automatically sent to the Record & Verify system after obtaining both physician and physicist signatures. An auto-commissioner was also developed to facilitate beam modeling based on water-tank measurements, which serves the purpose of fully independent verification. The dose calculation was performed on the whole patient volume with grid resolution of 2 mm x 2 mm x 2 mm. The 3D dose volume, treatment fields, point dose, Gamma Index with global 3%, 2mm criteria, three orthogonal dose profiles, dose volume histograms, and dosimetric constraints are metrics to compare the plan retrieved from TPS to the secondary dose verification and reported for clinicians' review. The whole in-house infrastructure went through extensive unit tests, dosimetric accuracy verifications, and alpha and beta tests before adopted for clinical use. The secondary dose and plan check infrastructure went live for CBCT-LINAC and MR-LINAC in our clinic and has since performed secondary check for every plan generated (846 plans and 622 plans, respectively, in less than 6 months.) The average processing time, from DICOM receiving to report generation, was 62 seconds for CBCT-LINAC and 130 seconds for MR-LINAC, which was 3-5 minutes shorter compared to using commercial software. More than 95% of CBCT-LINAC (MR-LINAC) plans had Gamma passing rates >99% (>95%). The in-house developed software, through strict verification and validation, has been integrated into the clinical system. It has greatly improved online adaptive quality assurance with efficient and streamlined clinical workflow. [ABSTRACT FROM AUTHOR]

Objective: Optimized deep brain stimulation (DBS) is fast becoming a therapy of choice for the treatment of Parkinson's disease (PD). However, the post-operative optimization (aimed at maximizing patient clinical benefits and minimizing adverse effects) of all possible DBS parameter settings using the standard-of-care clinical protocol requires numerous clinical visits, which substantially increases the time to optimization per patient (TPP), patient cost burden and limit the number of patients who can undergo DBS treatment. The TPP is further elongated in electrodes with stimulation directionality or in diseases with latency in clinical feedback. In this work, we proposed a deep learning and fMRI-based pipeline for DBS optimization that can potentially reduce the TPP from ~1 year to a few hours during a single clinical visit., Methods and Procedures: We developed an unsupervised autoencoder (AE)-based model to extract meaningful features from 122 previously acquired blood oxygenated level dependent (BOLD) fMRI datasets from 39 a priori clinically optimized PD patients undergoing DBS therapy. The extracted features are then fed into multilayer perceptron (MLP)-based parameter classification and prediction models for rapid DBS parameter optimization., Results: The AE-extracted features of optimal and non-optimal DBS were disentangled. The AE-MLP classification model yielded accuracy, precision, recall, F1 score, and combined AUC of 0.96 ± 0.04, 0.95 ± 0.07, 0.92 ± 0.07, 0.93 ± 0.06, and 0.98 respectively. Accuracies of 0.79 ± 0.04, 0.85 ± 0.04, 0.82 ± 0.05, 0.83 ± 0.05, and 0.70 ± 0.07 were obtained in the prediction of voltage, frequency, and x-y-z contact locations, respectively., Conclusion: The proposed AE-MLP models yielded promising results for fMRI-based DBS parameter classification and prediction, potentially facilitating rapid semi-automated DBS parameter optimization. Clinical and Translational Impact Statement-A deep learning-based pipeline for semi-automated DBS parameter optimization is presented, with the potential to significantly decrease the optimization duration per patient and patients' financial burden while increasing patient throughput., (© 2024 The Authors.)

DSS1, essential for BRCA2-RAD51 dependent homologous recombination (HR), associates with the helical domain (HD) and OB fold 1 (OB1) of the BRCA2 DSS1/DNA-binding domain (DBD) which is frequently targeted by cancer-associated pathogenic variants. Herein, we reveal robust ss/dsDNA binding abilities in HD-OB1 subdomains and find that DSS1 shuts down HD-OB1's DNA binding to enable ssDNA targeting of the BRCA2-RAD51 complex. We show that C-terminal helix mutations of DSS1, including the cancer-associated R57Q mutation, disrupt this DSS1 regulation and permit dsDNA binding of HD-OB1/BRCA2-DBD. Importantly, these DSS1 mutations impair BRCA2/RAD51 ssDNA loading and focus formation and cause decreased HR efficiency, destabilization of stalled forks and R-loop accumulation, and hypersensitize cells to DNA-damaging agents. We propose that DSS1 restrains the intrinsic dsDNA binding of BRCA2-DBD to ensure BRCA2/RAD51 targeting to ssDNA, thereby promoting optimal execution of HR, and potentially replication fork protection and R-loop suppression., (© 2024. The Author(s).)

Serous cystadenoma is a rare lesion in the para-testicular tissue, with even rarer reports of this entity occurring in the scrotum post-orchidopexy. We present such an occurrence, adding support for its existence as a distinct entity., Competing Interests: Declaration of Conflicting InterestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Introduction: The outcome of patients with metastatic colorectal cancer (mCRC) has improved significantly in the last few decades. Metastatic colorectal cancer is a highly heterogenous cancer. Beyond second line chemotherapy, treatment decisions are often based on molecular testing., Method: In this narrative review, we provide a comprehensive summary of data from key clinical trials and discuss how to integrate these agents into the current treatment landscape of metastatic colorectal cancer., Expert Opinion: In the era of precision medicine, molecular testing plays an increasingly important role in the management of mCRC. Efforts need to be made to target treatment based on molecular test results.

Background: Online adaptive radiotherapy (ART) involves the development of adaptable treatment plans that consider patient anatomical data obtained right prior to treatment administration, facilitated by cone-beam computed tomography guided adaptive radiotherapy (CTgART) and magnetic resonance image-guided adaptive radiotherapy (MRgART). To ensure accuracy of these adaptive plans, it is crucial to conduct calculation-based checks and independent verification of volumetric dose distribution, as measurement-based checks are not practical within online workflows. However, the absence of comprehensive, efficient, and highly integrated commercial software for secondary dose verification can impede the time-sensitive nature of online ART procedures., Purpose: The main aim of this study is to introduce an efficient online quality assurance (QA) platform for online ART, and subsequently evaluate it on Ethos and Unity treatment delivery systems in our clinic., Methods: To enhance efficiency and ensure compliance with safety standards in online ART, ART2Dose, a secondary dose verification software, has been developed and integrated into our online QA workflow. This implementation spans all online ART treatments at our institution. The ART2Dose infrastructure comprises four key components: an SQLite database, a dose calculation server, a report generator, and a web portal. Through this infrastructure, file transfer, dose calculation, report generation, and report approval/archival are seamlessly managed, minimizing the need for user input when exporting RT DICOM files and approving the generated QA report. ART2Dose was compared with Mobius3D in pre-clinical evaluations on secondary dose verification for 40 adaptive plans. Additionally, a retrospective investigation was conducted utilizing 1302 CTgART fractions from ten treatment sites and 1278 MRgART fractions from seven treatment sites to evaluate the practical accuracy and efficiency of ART2Dose in routine clinical use., Results: With dedicated infrastructure and an integrated workflow, ART2Dose achieved gamma passing rates that were comparable to or higher than those of Mobius3D. Additionally, it significantly reduced the time required to complete pre-treatment checks by 3-4 min for each plan. In the retrospective analysis of clinical CTgART and MRgART fractions, ART2Dose demonstrated average gamma passing rates of 99.61 ± 0.83% and 97.75 ± 2.54%, respectively, using the 3%/2 mm criteria for region greater than 10% of prescription dose. The average calculation times for CTgART and MRgART were approximately 1 and 2 min, respectively., Conclusion: Overall, the streamlined implementation of ART2Dose notably enhances the online ART workflow, offering reliable and efficient online QA while reducing time pressure in the clinic and minimizing labor-intensive work., (© 2023 American Association of Physicists in Medicine.)

The dependence of the diffusion MRI signal on the diffusion time carries signatures of restricted diffusion and exchange. Here we seek to highlight these signatures in the human brain by performing experiments using free gradient waveforms designed to be selectively sensitive to the two effects. We examine six healthy volunteers using both strong and ultra-strong gradients (80, 200 and 300 mT/m). In an experiment featuring a large set of 150 gradient waveforms with different sensitivities to restricted diffusion and exchange, our results reveal unique and different time-dependence signatures in grey and white matter. Grey matter was characterised by both restricted diffusion and exchange and white matter predominantly by restricted diffusion. Exchange in grey matter was at least twice as fast as in white matter, across all subjects and all gradient strengths. The cerebellar cortex featured relatively short exchange times (115 ms). Furthermore, we show that gradient waveforms with tailored designs can be used to map exchange in the human brain. We also assessed the feasibility of clinical applications of the method used in this work and found that the exchange-related contrast obtained with a 25-minute protocol at 300 mT/m was preserved in a 4-minute protocol at 300 mT/m and a 10-minute protocol at 80 mT/m. Our work underlines the utility of free waveforms for detecting time dependence signatures due to restricted diffusion and exchange in vivo, which may potentially serve as a tool for studying diseased tissue., Competing Interests: Declaration of Competing Interest Chakwizira A: none, Westin C-F: none, Szczepankiewicz F: none, Nilsson M: none. Zhu A and Foo T are employees of GE Research., (Copyright © 2023. Published by Elsevier Inc.)

Purpose: Ultrasound is often the preferred modality for image-guided therapy or treatment in organs such as liver due to real-time imaging capabilities. However, the reduced conspicuity of tumors in ultrasound images adversely impacts the precision and accuracy of treatment delivery. This problem is compounded by deformable motion due to breathing and other physiological activity. This creates the need for a fusion method to align interventional US with pre-interventional modalities that provide superior soft-tissue contrast (e.g., MRI) to accurately target a structure-of-interest and compensate for liver motion., Method: In this work, we developed a hybrid deformable fusion method to align 3D pre-interventional MRI and 3D interventional US volumes to target the structures-of-interest in liver accurately in real-time. The deformable multimodal fusion method involved an offline alignment of a pre-intervention MRI with a pre-intervention US volume using a traditional registration method, followed by real-time prediction of deformation using a trained deep-learning model between interventional US volumes across different respiratory states. This framework enables motion-compensated MRI-US image fusion in real-time for image-guided treatment., Results: The proposed hybrid deformable registration method was evaluated on three healthy volunteers across the pre-intervention MRI and 20 US volume pairs in the free-breathing respiratory cycle. The mean Euclidean landmark distance of three homologous targets in all three volunteers was less than 3 mm for percutaneous liver procedures., Conclusions: Preliminary results show that clinically acceptable registration accuracies for near real-time, deformable MRI-US fusion can be achieved by our proposed hybrid approach. The proposed combination of traditional and deep-learning deformable registration techniques is thus a promising approach for motion-compensated MRI-US fusion to improve targeting in image-guided liver interventions., (© 2023. CARS.)