FAM72A antagonizes UNG2 to promote mutagenic repair during antibody maturation.

Activation-induced cytidine deaminase (AID) catalyses the deamination of deoxycytidines to deoxyuracils within immunoglobulin genes to induce somatic hypermutation and class-switch recombination1,2. AID-generated deoxyuracils are recognized and processed by subverted base-excision and mismatch repair pathways that ensure a mutagenic outcome in B cells3-6. However, why these DNA repair pathways do not accurately repair AID-induced lesions remains unknown. Here, using a genome-wide CRISPR screen, we show that FAM72A is a major determinant for the error-prone processing of deoxyuracils. Fam72a-deficient CH12F3-2 B cells and primary B cells from Fam72a-/- mice exhibit reduced class-switch recombination and somatic hypermutation frequencies at immunoglobulin and Bcl6 genes, and reduced genome-wide deoxyuracils. The somatic hypermutation spectrum in B cells from Fam72a-/- mice is opposite to that observed in mice deficient in uracil DNA glycosylase 2 (UNG2)7, which suggests that UNG2 is hyperactive in FAM72A-deficient cells. Indeed, FAM72A binds to UNG2, resulting in reduced levels of UNG2 protein in the G1 phase of the cell cycle, coinciding with peak AID activity. FAM72A therefore causes U·G mispairs to persist into S phase, leading to error-prone processing by mismatch repair. By disabling the DNA repair pathways that normally efficiently remove deoxyuracils from DNA, FAM72A enables AID to exert its full effects on antibody maturation. This work has implications in cancer, as the overexpression of FAM72A that is observed in many cancers8 could promote mutagenesis.

Functional genomic landscape of cancer-intrinsic evasion of killing by T cells.

The genetic circuits that allow cancer cells to evade destruction by the host immune system remain poorly understood1-3. Here, to identify a phenotypically robust core set of genes and pathways that enable cancer cells to evade killing mediated by cytotoxic T lymphocytes (CTLs), we performed genome-wide CRISPR screens across a panel of genetically diverse mouse cancer cell lines that were cultured in the presence of CTLs. We identify a core set of 182 genes across these mouse cancer models, the individual perturbation of which increases either the sensitivity or the resistance of cancer cells to CTL-mediated toxicity. Systematic exploration of our dataset using genetic co-similarity reveals the hierarchical and coordinated manner in which genes and pathways act in cancer cells to orchestrate their evasion of CTLs, and shows that discrete functional modules that control the interferon response and tumour necrosis factor (TNF)-induced cytotoxicity are dominant sub-phenotypes. Our data establish a central role for genes that were previously identified as negative regulators of the type-II interferon response (for example, Ptpn2, Socs1 and Adar1) in mediating CTL evasion, and show that the lipid-droplet-related gene Fitm2 is required for maintaining cell fitness after exposure to interferon-γ (IFNγ). In addition, we identify the autophagy pathway as a conserved mediator of the evasion of CTLs by cancer cells, and show that this pathway is required to resist cytotoxicity induced by the cytokines IFNγ and TNF. Through the mapping of cytokine- and CTL-based genetic interactions, together with in vivo CRISPR screens, we show how the pleiotropic effects of autophagy control cancer-cell-intrinsic evasion of killing by CTLs and we highlight the importance of these effects within the tumour microenvironment. Collectively, these data expand our knowledge of the genetic circuits that are involved in the evasion of the immune system by cancer cells, and highlight genetic interactions that contribute to phenotypes associated with escape from killing by CTLs.

Identifying human pre-mRNA cleavage and polyadenylation factors by genome-wide CRISPR screens using a dual fluorescence readthrough reporter.

Messenger RNA precursors (pre-mRNA) generally undergo 3' end processing by cleavage and polyadenylation (CPA), which is specified by a polyadenylation site (PAS) and adjacent RNA sequences and regulated by a large variety of core and auxiliary CPA factors. To date, most of the human CPA factors have been discovered through biochemical and proteomic studies. However, genetic identification of the human CPA factors has been hampered by the lack of a reliable genome-wide screening method. We describe here a dual fluorescence readthrough reporter system with a PAS inserted between two fluorescent reporters. This system enables measurement of the efficiency of 3' end processing in living cells. Using this system in combination with a human genome-wide CRISPR/Cas9 library, we conducted a screen for CPA factors. The screens identified most components of the known core CPA complexes and other known CPA factors. The screens also identified CCNK/CDK12 as a potential core CPA factor, and RPRD1B as a CPA factor that binds RNA and regulates the release of RNA polymerase II at the 3' ends of genes. Thus, this dual fluorescence reporter coupled with CRISPR/Cas9 screens reliably identifies bona fide CPA factors and provides a platform for investigating the requirements for CPA in various contexts.

Identifying cell receptors for the nanoparticle protein corona using genome screens.

Nanotechnology provides platforms to deliver medical agents to specific cells. However, the nanoparticle's surface becomes covered with serum proteins in the blood after administration despite engineering efforts to protect it with targeting or blocking molecules. Here, we developed a strategy to identify the main interactions between nanoparticle-adsorbed proteins and a cell by integrating mass spectrometry with pooled genome screens and Search Tool for the Retrieval of Interacting Genes analysis. We found that the low-density lipoprotein (LDL) receptor was responsible for approximately 75% of serum-coated gold nanoparticle uptake in U-87 MG cells. Apolipoprotein B and complement C8 proteins on the nanoparticle mediated uptake through the LDL receptor. In vivo, nanoparticle accumulation correlated with LDL receptor expression in the organs of mice. A detailed understanding of how adsorbed serum proteins bind to cell receptors will lay the groundwork for controlling the delivery of nanoparticles at the molecular level to diseased tissues for therapeutic and diagnostic applications.

Identifying priorities for balance interventions through a participatory co-design approach with end-users.

BACKGROUND: Most individuals living with spinal cord injuries/diseases (SCI/D) or stroke experience at least one fall each year; hence, the development of interventions and technologies that target balance control is needed. The purpose of this study was to identify and explore the priorities for balance-focused interventions and technologies from the perspectives of end-users to assist with the design of an intervention that combines functional electrical stimulation (FES) with visual feedback training for standing balance. METHODS: Two individuals with SCI/D, one individual with stroke, two physical therapists (PT) and one hospital administrator were recruited. Participants attended three focus group meetings that followed a participatory co-design approach. A semi-structured interview guide, developed from the FAME (Feasibility, Appropriateness, Meaningfulness, Effectiveness, Economic Evidence) framework, was used to lead the discussion, querying participants' experiences with balance deficits and interventions, and FES. Meetings were audio-recorded and transcribed verbatim. An iterative and reflexive inductive thematic analysis was applied to the transcripts by three researchers. RESULTS: Four themes were identified: (1) Balance is meaningful for daily life and rehabilitation. Participants acknowledged various factors influencing balance control and how balance deficits interfered with participation in activities. End-users stressed the importance of continuing to work on one's balance after discharge from hospital-based rehabilitation. (2) Desired characteristics of balance interventions. Participants explained that balance interventions should be tailored to an individual's unique needs and goals, relevant to their lives, balance their safety and risk, and be engaging. (3) Prior experiences with FES to inform future therapeutic use. Participants with stroke or SCI/D described initial apprehension with FES, but experienced numerous benefits that motivated them to continue with FES. Challenges with FES were mentioned, including wires, cost, and time of set up. (4) Potential role of FES in balance interventions. Participants felt that FES would complement balance interventions; however, they had not experienced this combination of therapies previously. CONCLUSIONS: End-users described how their experiences with balance deficits, rehabilitation, and FES informed their priorities for balance interventions. The findings inform the design and implementation of future balance interventions for individuals with SCI/D or stroke, including an intervention involving FES and visual feedback training.

Interrater reliability of the Standing and Walking Assessment Tool for spinal cord injury.

STUDY DESIGN: Psychometric study. OBJECTIVES: The Standing and Walking Assessment Tool (SWAT) is a standardized approach to the evaluation of standing and walking capacity following traumatic spinal cord injury (tSCI) in Canada. The SWAT classifies individuals with a tSCI into 12 stages of standing and walking capacity that are paired with well-established outcome measures, such as the Berg Balance Scale and 10-m Walk Test. Prior research has demonstrated the validity and responsiveness of the SWAT stages; however, the reliability remains unknown. The objective of this study was to evaluate the interrater reliability of the SWAT stages. SETTING: Inpatient units of two Canadian rehabilitation hospitals. METHODS: Adults with sub-acute tSCI were recruited. SWAT stage was evaluated for each participant by two physical therapists separately. The two therapists aimed to complete the evaluations within one day of each other. To evaluate interrater reliability, the percentage agreement between the SWAT stages rated by the two physical therapists was calculated, along with a linear weighted kappa statistic with a 95% CI. RESULTS: Forty-five individuals with sub-acute tSCI (36 males, 9 females, mean (SD) age of 54.8 (17.9) years) participated. The percentage agreement in SWAT stages between the two physical therapists was 75.6%. A kappa statistic of 0.93 with a 95% CI, 0.81-1.05 was obtained. In cases where therapists disagreed (18% of participants), therapists differed by 1-2 stages only. CONCLUSIONS: The SWAT stages have high interrater reliability, providing further support for the use of the SWAT in rehabilitation practice in Canada.

A method for benchmarking genetic screens reveals a predominant mitochondrial bias.

We present FLEX (Functional evaluation of experimental perturbations), a pipeline that leverages several functional annotation resources to establish reference standards for benchmarking human genome-wide CRISPR screen data and methods for analyzing them. FLEX provides a quantitative measurement of the functional information captured by a given gene-pair dataset and a means to explore the diversity of functions captured by the input dataset. We apply FLEX to analyze data from the diverse cell line screens generated by the DepMap project. We identify a predominant mitochondria-associated signal within co-essentiality networks derived from these data and explore the basis of this signal. Our analysis and time-resolved CRISPR screens in a single cell line suggest that the variable phenotypes associated with mitochondria genes across cells may reflect screen dynamics and protein stability effects rather than genetic dependencies. We characterize this functional bias and demonstrate its relevance for interpreting differential hits in any CRISPR screening context. More generally, we demonstrate the utility of the FLEX pipeline for performing robust comparative evaluations of CRISPR screens or methods for processing them.

Parents' perceptions of functional electrical stimulation as an upper limb intervention for young children with hemiparesis: qualitative interviews with mothers.

BACKGROUND/OBJECTIVE: To explore parents' perceptions of an upper extremity (UE) intervention using functional electrical stimulation (FES) for young children with hemiparesis. METHODS: Parents of children aged 3-6 years with a history of perinatal stroke, impaired UE function, and participation in a 12-week FES intervention delivered at a hospital were included in this exploratory qualitative study. Nine mothers participated in a semi-structured interview < 1 week after their child completed the FES intervention (MyndMove®, MyndTec Inc.) targeting the hemiparetic UE. Open-ended questions queried parents' goals, perceived benefits, and challenges of the FES intervention. Interviews were audio recorded and transcribed verbatim. Qualitative conventional content analysis was used to analyze the transcripts. RESULTS: Five themes were identified. 1) Parents' expectations for the FES intervention. Mothers described setting functional, exploratory, and realistic goals, yet feeling initial apprehension towards FES. 2) Perceived improvement. Physical, functional, and psychological improvements were observed with FES; however, there was still room for improvement. 3) Factors influencing the FES intervention. Program structure, therapist factors, and child factors influenced perceived success. 4) Lack of access to intensive therapy. Mothers noted that FES is not provided in mainstream therapy; however, they wanted access to FES outside of the study. They also highlighted socioeconomic challenges to accessing FES. 5) Strategies to facilitate participation. The mothers provided suggestions for program structure and delivery, and session delivery. CONCLUSIONS: Mothers perceived the FES intervention to have physical, functional and psychological benefits for their children. Interest in continuing with FES highlights a need to improve access to this therapy for young children.

Validity and responsiveness of the Standing and Walking Assessment Tool for sub-acute traumatic spinal cord injury.

STUDY DESIGN: This is a retrospective longitudinal study. OBJECTIVE: The Standing and Walking Assessment Tool (SWAT) combines stages of standing and walking recovery (SWAT stages) with established measures (Berg Balance Scale (BBS), 10-m walk test (10MWT), 6-min walk test (6MWT), and modified Timed Up-and-Go (mTUG)). We evaluated the SWAT's validity (known-groups and convergent) and responsiveness among inpatients with sub-acute, traumatic spinal cord injury (SCI). SETTING: Ten Canadian rehabilitation hospitals. METHODS: Upon admission, SWAT stage and core measures (BBS, 10MWT, 6MWT, and mTUG), International Standards for Neurological Classification of SCI sensory and motor scores, and Spinal Cord Independence Measure III (SCIM) were collected from 618 adults with SCI. Known-groups validity was evaluated by comparing SWAT stage distributions across American Spinal Injury Association Impairment Scale (AIS) classification. Convergent validity was evaluated by correlating SWAT stages with scores on other measures using Spearman's rho. The SWAT (stage and core measures) was re-administered at discharge. To evaluate responsiveness, SWAT stages at admission and discharge were compared. The standardized response mean (SRM) was used to evaluate the responsiveness of core SWAT measures. RESULTS: The SWAT stage distribution of participants with AIS D injuries differed from those of participants with AIS A-C injuries (p ≤ 0.002). SWAT stages correlated strongly with BBS and motor scores (ρ = 0.778-0.836), and moderately with SCIM, mTUG, 10MWT, 6MWT, and sensory scores (ρ = 0.409-0.692). Discharge SWAT stage was greater than the admission stage (p < 0.0001). The BBS was the most responsive core SWAT measure (SRM = 1.26). CONCLUSIONS: The SWAT is a valid and responsive approach to the measurement of standing and walking ability during sub-acute SCI.

Interjoint coordination between the ankle and hip joints during quiet standing in individuals with motor incomplete spinal cord injury.

Individuals with motor incomplete spinal cord injuries (iSCI) often have impaired abilities to maintain upright balance. For able-bodied (AB) individuals, the ankle and hip joint accelerations are in antiphase to minimize the postural sway during quiet standing. Here we investigated how interjoint coordination between the ankle and hip joints was affected in individuals with iSCI, leading to their larger postural sway during quiet standing. Data from 16 individuals with iSCI, 14 age- and sex-matched AB individuals, and 13 young AB individuals were analyzed. The participants performed quiet standing during which kinematic and kinetic data were recorded. Postural sway was quantified using center-of-pressure velocity and center-of-mass acceleration. Individual ankle and hip joint kinematics were quantified, and the interjoint coordination was assessed using the cancellation index (CI), goal-equivalent variance (GEV), nongoal-equivalent variance (NGEV), and uncontrolled manifold (UCM) ratio. Individuals with iSCI displayed greater postural sway compared with AB individuals. The contribution of ankle angular acceleration toward one's sway was significantly greater for those with iSCI compared with AB groups. CI and the UCM ratios were not statistically different between the groups, while GEV and NGEV were significantly greater for the iSCI group compared with the AB groups. We demonstrated that individuals with iSCI show larger postural sway compared with the AB individuals during quiet standing, primarily due to larger ankle joint acceleration. We also demonstrated that the interjoint coordination between ankle and hip joint is not affected in individuals with iSCI, which is not successfully able to reduce the large COM acceleration.NEW & NOTEWORTHY There are limited studies investigating the biomechanics of standing balance for individuals with motor incomplete spinal cord injury (iSCI). Through our study, we found that these individuals with iSCI demonstrated increased postural sway primarily due to increased ankle joint accelerations. In addition, the ankle-hip coordination was equivalent between able-bodied individuals and those with motor incomplete spinal cord injury, which was not able to reduce the large body acceleration.

Cosine tuning determines plantarflexors' activities during human upright standing and is affected by incomplete spinal cord injury.

Plantarflexors such as the soleus (SOL) and medial gastrocnemius (MG) play key roles in controlling bipedal stance; however, how the central nervous system controls the activation levels of these plantarflexors is not well understood. Here we investigated how the central nervous system controls the plantarflexors' activation level during quiet standing in a cosine tuning manner where the maximal activation is achieved in a preferred direction (PD). Furthermore, we investigated how spinal cord injury affects these plantarflexors' activations. Thirteen healthy adults (AB) and thirteen individuals with chronic, incomplete spinal cord injury (iSCI) performed quiet standing trials. Their body kinematics and kinetics as well as electromyography signals from the MG and SOL were recorded. In the AB group, we found that the plantarflexors followed the cosine tuning manner during quiet standing. That is, MG was most active when the ratio of plantarflexion torque to knee extension torque was ~2:-3, whereas SOL was most active when the ratio was ~2:1. This suggests that the SOL muscle, despite being a monoarticular muscle, is sensitive to both ankle plantarflexion and knee extension during quiet standing. The difference in the PDs accounts for the phasic activity of MG and for the tonic activity of SOL. Unlike the AB group, the MG's activity was similar to the SOL's activity in the iSCI group, and the SOL PDs were similar to those in the AB group. This result suggests that chronic iSCI affects the control strategy, i.e., cosine tuning, for MG, which may affect standing balance in individuals with iSCI.NEW & NOTEWORTHY Soleus muscle shows a tonic activity whereas medial gastrocnemius muscle shows a phasic activity during quiet standing. Cosine tuning and their preferred direction account for the different muscle activation patterns between these two muscles. In individuals with chronic incomplete spinal cord injury, the preferred direction of gastrocnemius medial head is affected, which may result in their deteriorated standing balance.

Reactive stepping after a forward fall in people living with incomplete spinal cord injury or disease.

STUDY DESIGN: Cross sectional. OBJECTIVES: To compare the reactive stepping ability of individuals living with incomplete spinal cord injury or disease (SCI/D) to that of sex- and age-matched able-bodied adults. SETTING: A tertiary SCI/D rehabilitation center in Canada. METHODS: Thirty-three individuals (20 with incomplete SCI/D) participated. Participants assumed a forward lean position in standing whilst 8-12% of their body weight was supported by a horizontal cable at waist height affixed to a rigid structure. The cable was released unexpectedly, simulating a forward fall and eliciting one or more reactive steps. Behavioral responses (i.e., single step versus non-single step) were compared using a Chi-square test. The following temporal parameters of reactive stepping were compared using t-tests: the onset of muscle activation in 12 lower extremity muscles (six per limb) and step-off, step contact and swing time of the stepping leg. RESULTS: Behavioral responses were significantly different between groups (χ2 = 13.9 and p < 0.01) with participants with incomplete SCI/D showing more non-single step responses (i.e., multi-steps and falls). The onsets of muscle activation were more variable in participants with incomplete SCI/D, but only the stepping tibialis anterior showed a significantly slower onset in this group compared with able-bodied adults (t = -2.11 and p = 0.049). Movement timing of the stepping leg (i.e., step-off, step contact, and swing time) was not significantly different between groups. CONCLUSIONS: Reactive stepping ability of individuals with incomplete SCI/D is impaired; however, this impairment is not explained by temporal parameters. The findings suggest that reactive stepping should be targeted in the rehabilitation of ambulatory individuals with SCI/D.

Radiographic abnormalities, bladder interventions, and bladder surgery in the first decade of life in children with spina bifida.

BACKGROUND: Spina bifida (SB) patients are at increased risk for hydronephrosis, bladder storage and emptying problems, and renal failure that may require multiple bladder surgeries. METHODS: We retrospectively reviewed patients born with SB 2005-2009, presenting to our institution within 1 year of birth. Outcomes at 8-11 years old included final renal/bladder ultrasound (RBUS) results, clean intermittent catheterization (CIC) use, anticholinergic use, surgical interventions, and final renal function. We excluded those without follow-up past age 8 and/or no RBUS or fluoroscopic urodynamic images (FUI) within the first year of life. Imaging was independently reviewed by four pediatric urologists blinded to radiologists' interpretation and initial findings compared with final outcomes. RESULTS: Of 98 children, 62 met inclusion criteria (48% male, 76% shunted). Median age at last follow-up was 9.6 years. Upon initial imaging, 74% had hydronephrosis (≥ SFU grade 1), decreasing to 5% at 10 years (p < 0.0001). Initially, 9% had ≥ SFU grade 3 hydronephrosis, decreasing to 2% (p = 0.13). CIC and anticholinergic use increased from 61% and 37% to 87% and 86%, respectively (p = 0.001 and p < 0.0001, respectively). With follow-up, 55% had surgical intervention and 23% had an augmentation. Of children with a serum creatinine/cystatin-C at 8-11 years old, one had confirmed chronic kidney disease (stage 2). CONCLUSIONS: Despite initial high incidence of hydronephrosis, this was low grade and resolved in the first decade of life. Additionally, the 8-11-year incidence of kidney disease and upper tract changes was low due to aggressive medical management.

Structure-activity relationship of uridine-based nucleoside phosphoramidate prodrugs for inhibition of dengue virus RNA-dependent RNA polymerase.

To identify a potent and selective nucleoside inhibitor of dengue virus RNA-dependent RNA polymerase, a series of 2'- and/or 4'-ribose sugar modified uridine nucleoside phosphoramidate prodrugs and their corresponding triphosphates were synthesized and evaluated. Replacement of 2'-OH with 2'-F led to be a poor substrate for both dengue virus and human mitochondrial RNA polymerases. Instead of 2'-fluorination, the introduction of fluorine at the ribose 4'-position was found not to affect the inhibition of the dengue virus polymerase with a reduction in uptake by mitochondrial RNA polymerase. 2'-C-ethynyl-4'-F-uridine phosphoramidate prodrug displayed potent anti-dengue virus activity in the primary human peripheral blood mononuclear cell-based assay with no significant cytotoxicity in human hepatocellular liver carcinoma cell lines and no mitochondrial toxicity in the cell-based assay using human prostate cancer cell lines.

Variation in Surgical Antibiotic Prophylaxis for Outpatient Pediatric Urological Procedures at United States Children's Hospitals.

PURPOSE: Guidelines recommend surgical antibiotic prophylaxis for clean-contaminated procedures but none for clean procedures. The purpose of this study was to describe variations in surgical antibiotic prophylaxis for outpatient urological procedures at United States children's hospitals. MATERIALS AND METHODS: Using the PHIS (Pediatric Health Information System®) database we performed a retrospective cohort study of patients younger than 18 years who underwent clean and/or clean-contaminated outpatient urological procedures from 2012 to 2014. We excluded those with concurrent nonurological procedures or an abscess/infected wound. We compared perioperative antibiotic charges for clean vs clean-contaminated procedures using a multilevel logistic regression model with a random effect for hospital. We also examined whether hospitals that were guideline compliant for clean procedures, defined as no surgical antibiotic prophylaxis, were also compliant for clean-contaminated procedures using the Pearson correlation coefficient. We examined hospital level variation in antibiotic rates using the coefficient of variation. RESULTS: A total of 131,256 patients with a median age of 34 months at 39 hospitals met study inclusion criteria. Patients undergoing clean procedures were 14% less likely to receive guideline compliant surgical antibiotic prophylaxis than patients undergoing clean-contaminated procedures (OR 0.86, 95% CI 0.84-0.88, p <0.0001). Hospitals that used antibiotics appropriately for clean-contaminated procedures were more likely to use antibiotics inappropriately for clean procedures (r = 0.7, p = 0.01). Greater variation was seen for hospital level compliance with surgical antibiotic prophylaxis for clean-contaminated procedures (range 9.8% to 97.8%, coefficient of variation 0.36) than for clean procedures (range 35.0% to 98.2%, coefficient of variation 0.20). CONCLUSIONS: Hospitals that used surgical antibiotic prophylaxis appropriately for clean-contaminated procedures were likely to use surgical antibiotic prophylaxis inappropriately for clean procedures. More variation was seen in hospital level guideline compliance for clean-contaminated procedures.

Cerebral arterial and venous blood flow in adolescent multiple sclerosis patients and age-matched controls using phase contrast MRI.

PURPOSE: Altered cerebrovascular blood flow has been proposed as a mechanism for multiple sclerosis (MS). The primary objective of this study was to measure arterial and venous blood flow in adolescent MS patients and healthy controls (HC), in whom confounding factors such as age and lifestyle are less influential. MATERIALS AND METHODS: Phase-contrast magnetic resonance imaging (MRI) was used to measure flow in 26 MS patients and 26 controls aged 17.7 ± 1.8 and 17.8 ± 2.1 years, respectively. Flow was measured in the left and right internal carotid arteries (ICA), vertebral arteries (VA), internal jugular veins (IJV), and epidural veins (EV). Eighteen MS patients returned for a second MRI examination after 6 months. In all participants, ultrasound criteria for chronic cerebrospinal venous insufficiency (CCSVI) were also evaluated. RESULTS: Flows (mL/min) in the MS group versus HC group were as follows: right ICA = 262 ± 57 vs. 263 ± 32, left ICA = 260 ± 67 vs. 270 ± 36, right VA = 96 ± 50 vs. 103 ± 30, left VA = 104 ± 37 vs. 118 ± 41, right IJV = 342 ± 180 vs. 345 ± 195, left IJV = 190 ± 131 vs. 250 ± 148, right EV = 33 ± 29 vs. 48 ± 43, and left EV = 36 ± 35 vs. 44 ± 28 (P > 0.17 for all comparisons). In MS participants, a nonsignificant trend to lower flow in the left IJV was observed, and the flow pulsatility index in the epidural veins was higher. Two MS participants met ultrasound criteria for CCSVI, but no significant difference in flow was detected. CONCLUSION: No population difference in flow rate was detected in adolescent MS participants relative to age-matched controls.

Development of an activity-based therapy tracking tool: Item generation and reduction using the Delphi method.

CONTEXT/OBJECTIVE: Activity-based therapies (ABT) are increasingly used in rehabilitation after spinal cord injury or disease (SCI/D). However, the absence of standardized tools to track the details of an ABT program hinders the collection of data needed for client-tailored programming and resource allocation. The objective of this study is to determine the content to include in an ABT tracking tool for people living with SCI/D. DESIGN: Cross-sectional e-survey. SETTING: Community. PARTICIPANTS: The 60 participants from Canada and the United States who had knowledge and/or experience with ABT included: individuals with SCI/D; hospital clinicians (i.e. physical and occupational therapists/assistants); community-based clinicians; hospital or community clinic administrators; researchers; and funders, advocates and policy makers. INTERVENTIONS: None. OUTCOME MEASURES: A Delphi e-survey comprised 16 types of ABT (e.g. treadmill training) and 4 types of technology (e.g. virtual reality). Participants rated the importance of including each item on a tracking tool and the feasibility to track each item using a 9-point Likert scale. RESULTS: After two survey rounds, nine types of ABT and one technology were identified as important to include in a tracking tool. All items rated as important were considered feasible for clinicians and people with SCI/D to track, except crawling. CONCLUSION: This study identified the types of ABT and technology to include in an ABT tracking tool. Such a tool may provide details of an ABT program that can support decision-making at the individual, program and health system levels and aid the development of best practice guidelines.

Tracking activity-based therapy for people living with spinal cord injury or disease: insights gained through focus group interviews with key stakeholders.

PURPOSE: The development of a tool to track participation in activity-based therapy (ABT) for people with spinal cord injury or disease (SCI/D) was identified as a priority of the Canadian ABT Community of Practice. The objective of this study was to understand multi-stakeholder perspectives on tracking ABT participation across the continuum of care. MATERIALS AND METHODS: Forty-eight individuals from six stakeholder groups (persons living with SCI/D; hospital therapists; community trainers; administrators; researchers; and funders, advocates and policy experts) were recruited to participate in focus group interviews. Participants were asked open-ended questions concerning the importance of and parameters around tracking ABT. Transcripts were analyzed using conventional content analysis. RESULTS: Themes reflected the Who, What, Where, When, Why and How of tracking ABT. Participants described the importance of involving hospital therapists, community trainers and individuals with SCI/D in tracking ABT to capture both subjective and objective parameters across the continuum of care and injury trajectory. Digital tracking tools were favoured, although paper-based versions were regarded as a necessity in some circumstances. CONCLUSIONS: Findings highlighted the importance of tracking ABT participation for individuals with SCI/D. The information may guide the development of ABT practice guidelines and support the implementation of ABT in Canada.

Tracking the details of activity-based therapy (ABT) sessions and programs across the continuum of care and injury trajectory may provide important information to support the development of ABT practice guidelines and implementation strategies.Tracking objective and subjective parameters are needed to provide a comprehensive description of an ABT session and program.Clinicians and individuals with spinal cord injury or disease (SCI/D) should both be able to track ABT to accommodate all settings and types of data.Digital tracking tools, such as an app, may provide an accessible, versatile and efficient way of tracking ABT.

Mapping of DDX11 genetic interactions defines sister chromatid cohesion as the major dependency.

DDX11/Chl1R is a conserved DNA helicase with roles in genome maintenance, DNA replication, and chromatid cohesion. Loss of DDX11 in humans leads to the rare cohesinopathy Warsaw breakage syndrome. DDX11 has also been implicated in human cancer where it has been proposed to have an oncogenic role and possibly to constitute a therapeutic target. Given the multiple roles of DDX11 in genome stability and its potential as an anticancer target, we set out to define a complete genetic interaction profile of DDX11 loss in human cell lines. Screening the human genome with clustered regularly interspaced short palindromic repeats (CRISPR) guide RNA drop out screens in DDX11-wildtype (WT) or DDX11-deficient cells revealed a strong enrichment of genes with functions related to sister chromatid cohesion. We confirm synthetic lethal relationships between DDX11 and the tumor suppressor cohesin subunit STAG2, which is frequently mutated in several cancer types and the kinase HASPIN. This screen highlights the importance of cohesion in cells lacking DDX11 and suggests DDX11 may be a therapeutic target for tumors with mutations in STAG2.