Check out some of the papers that were recently published by DMCBH members:
Helen Tremlett: Data resource profile: PharmaNet, the database for prescription drug dispensing in British Columbia, Canada
Journal: International Journal of Population Data Science
This study is a comprehensive data resource profile of PharmaNet, a drug information system containing nearly 30 years of data on all prescription drugs and some medical supplies dispensed at pharmacies across BC. Its data contains over 1.8 billion records, and over 75 million new records are added annually and can be requested for research purposes. PharmaNet is a powerful resource for health research such as policy evaluation and long-term real-world drug safety.
Anthony Traboulsee: Comparative effectiveness of rituximab versus ocrelizumab in relapsing multiple sclerosis on clinical relapses and radiological outcomes in British Columbia, Canada
Journal: Multiple Sclerosis Journal
In this study, researchers compared the effectiveness of two medications used to treat relapsing multiple sclerosis (RMS): rituximab and ocrelizumab. Previous studies have suggested that rituximab may be less effective than ocrelizumab. Researchers looked at individuals with RMS and their relapse frequency and brain activity through MRI scans. Results indicate that both rituximab and ocrelizumab are effective treatments, but ocrelizumab may suppress relapses better. Because relapses were rare overall, additional studies are needed to determine a significant difference.
Journal: Frontiers in Health Services
In this study, researchers examined how often children and adolescents accessed mental health services and support (MHSS) during the COVID-19 pandemic and the factors associated with their use. After analyzing data from 1,100 participants, 17% self-reported access to MHSS over a 15-month period. Factors that were associated with MHSS use included: accessing COVID-19 related income support, missing school, being slightly or very/extremely worried in the past 2 weeks, and most strongly, having chronic health condition. Those who reported mental health ratings of very good or excellent compared with good before COVID-19 were less likely to access MHSS. Further research on the use of MHSS is needed to provide effective mental healthcare for children.
Helen Tremlett: The many faces of the multiple sclerosis population in Canada
Journal: Multiple Sclerosis and Related Disorders
Most studies of people with multiple sclerosis (MS) in Canada only report age and sex. In this study, researchers conducted a national survey to capture diversity characteristics of people with MS ages 18 and older. 857 people completed the survey over the course of 8 months. Most participants (93%) identified as White, 4.9% identified as Indigenous, and 2.1% identified as Black. Most participants were female at birth (83.5%) and 101 (11.9%) identified as 2SLGBTQI+. 51.2% had household income over $100,000, and 47.4% had at least one university degree. Like Canada’s population, the MS community is diverse, underscoring the importance of inclusive research and clinical care for the MS community in the future.
Mypinder Sekhon: Burden of and risk factors for neurological complications in critical illness
Journal: Intensive Care Medicine
This review discusses how neurological complications are common among patients admitted to an intensive care unit (ICU) experiencing critical illness. These complications are recognized as major contributors to severe psychological stress on the brain and long-term disability. Researchers have identified modifiable risk factors such as standardized delirium screening (routine check for delirium in patients) and mitigating environmental contributors such as sleep disruption and immobility. Factors that may contribute to under recognition of neurological complications include different definitions of risk factors between studies or different surveillance practices, as well as an incomplete understanding of the mechanisms of neurological injury and recovery in the brain. This review highlights knowledge gaps and limitations to improve upon future research.
Neil Cashman: Could anticholinergics accelerate ALS progression? A critical perspective on drug safety and disease vulnerability
Journal: Expert Opinion on Drug Safety
This review examined the use of anticholinergic medications in people with amyotrophic lateral sclerosis (ALS), a progressive neurodegenerative disorder with diverse symptoms and limited treatment options. Anticholinergic medications (which block the action of the neurotransmitter acetylcholine) are commonly used in ALS care, however, their effects may pose underrecognized risks for those with ALS. Drawing on evidence from studies of non-ALS populations, the review found that higher anticholinergic burden (the combined effects of using multiple medications that block acetylcholine) is associated with various side effects such as cognitive decline and respiratory complications. Researchers suggest that anticholinergic burden may be a risk factor in ALS and suggest prioritizing longitudinal studies and integrating anticholinergic burden assessment into ALS care.
Jessica Rosin: Expression and Role of Colony Stimulating Factor 1 Receptor During Odontogenesis
Journal: Journal of Developmental Biology
This study looked at whether the colony-stimulating factor-1 receptor (CSF1R) directly affects teeth development in the embryo or if poor teeth development is caused by abnormal bone development around the teeth. Using histology and high-resolution micro-computed tomography, researchers examined early stages of teeth development and the surrounding bone in the embryonic and postnatal stages by blocking CSF1R activity in pregnant mice. Results showed that inhibiting CSF1R caused changes in the shape and structure of developing teeth and were linked to problems with normal bone development. However, blocking CSF1R after birth did not affect the structure or growth of adult teeth. The findings suggest that CSF1R plays an important, time-specific role in early teeth development by helping to maintain the bone environment needed for normal tooth formation.
Jessica Rosin: CSF1R+ Macrophages and Osteoclasts Are Essential for Limb Bone Development During Embryogenesis
Journal: Journal of Developmental Biology
This study looked at the role of CSF1R (colony-stimulating factor-1 receptor) in supporting the development and function of specific cells, macrophages and osteoclasts, during limb development in the embryo. Researchers blocked CSF1R activity in pregnant mice to examine how inhibiting this receptor impacts embryonic limb development. They found that this eliminated CSF1R-dependent cells, including a complete loss of embryonic osteoclasts, in developing limb bones, which led to underdeveloped limbs after birth. Researchers conclude that the CSF1R inhibitor effectively depletes CSF1R macrophages and osteoclasts in embryonic limbs and suggest that CSF1R-dependent cells play an essential role in limb bone development.
Jehannine (J9) Austin: Guidance from an informed public on collecting and sharing PGx test results for major depressive disorder: “It’s no different from your blood type”
Journal: Pharmacogenomics
Many individuals with major depressive disorder (MDD) go through a long process of trial-and-error before finding medication that works for them. Researchers believe pharmacogenomic (PGx) testing for MDD can help find medication faster, but there are data privacy and health equity concerns before using the test. 30 individuals attended a public deliberation in Vancouver to help address these concerns before implementing PGx testing. They concluded with four positions on implementation: 1) PGx test results should be treated like other lab results; 2) stored in electronic medical records; 3) shared with patients and healthcare professionals in the circle of care; and 4) healthcare professionals must be educated on the test.
Julie Robillard: Debate: Conversational AI and young people’s mental health – friend or foe? – the illusion of a safe space for youth mental health
Journal: Child and Adolescent Mental Health
Artificial intelligence (AI) chatbots are increasingly used for mental health support among youth, but their safety and ethical structures remain unclear. Researchers drew on observations from 117 public chatbot applications and observed that entering personal information, agreeing to extensive data sharing, and making payments are explicit and sometimes implicit requirements to fully engage with the AI chatbot. The chatbots often emphasize its professional expertise and can mislead users to overestimate the applications’ capabilities. Researchers conclude that many AI mental health chatbots create the illusion of a safe and accessible therapeutic space, therefore it is important to raise awareness and encourage users to make informed decisions about their use.
Helen Tremlett: Sex differences in healthcare use before the first multiple sclerosis-related demyelinating event
Journal: Multiple Sclerosis and Related Disorders
Researchers looked at the connection between the multiple sclerosis (MS) prodrome (early set of signs or symptoms that indicate onset of an illness) and healthcare use between male and female patients’ pre-onset of MS. They examined healthcare use up to 29 years prior to onset between sex by using administrative data of annual doctor visit rates. Researchers discovered those who developed MS were seeing doctors up to 10 years before onset of MS, and males showed stronger increase in doctor visits. Researchers also observed an increase in mental health related visits beginning around 4 years before MS onset and was higher in males, who additionally had more general signs/symptoms and injury-related visits than females. These findings suggest that prodromal MS patterns vary by sex.
Thalia Field: Sex differences in brain frailty measures and outcomes after endovascular thrombectomy: ESCAPE-NA1 analysis
Journal: Journal of the Neurological Sciences
This study looked at sex differences in brain frailty (signs of brain aging and damage) after a severe ischemic stroke treated with endovascular thrombectomy, a procedure that removes blood clots from blocked arteries. Researchers analyzed brain frailty markers on MRI scans, such as brain shrinkage and blood vessel-related changes, and examined how these were linked to independence 90 after treatment. While the study found no significant differences between men and women, exploratory analyses suggested that several brain frailty markers were associated with a lower likelihood of recovery in women. Overall, the findings suggest brain frailty is an important predictor of stroke recovery but larger studies are needed to determine if there are meaningful sex-specific differences.
Sam Fereshtehnejad: Disease-Duration-Specific Percentiles for Prospective Subtyping of Parkinson’s Disease: A PPMI-Based Study
Journal: Movement Disorders Clinical Practice
This study developed a new way to classify patients with Parkinson’s disease (PD) into groups based on different disease progression rates during the first five years after diagnosis. A previous model divided PD into three groups: diffuse malignant (DM), intermediate (IM) and mild-motor predominant (MMP), but this model lacked information on disease-duration specific thresholds to apply at different disease stages. Researchers used Parkinson’s Precision Medicine Initiative (PPMI) data and measured motor and non-motor symptoms and computed percentiles, which allows clinicians to classify patients into one of the three groups to have a better grasp on their disease progression in comparison to others at the same stage of disease. The study found that the DM group progressed significantly faster than the IM and MMP groups. This new tool can help researchers identify patients more accurately for clinical trials and treatments.
Brett Hilton: An intrinsic cytoskeletal oscillator establishes neuronal polarity
Journal: Nature
Researchers are curious on how a neuron specifies which of its neurites becomes the axon while the others become dendrites. This study emphasizes that this selection does not only rely on growth cones (structures at the tip of axons and dendrites that guide the neuron to their target) that sense external cues, but the nerve cell soma (cell body) acts as the primary organizer in the process. Researchers used multiple approaches to examine neurons, such as live imaging and optogenetics. They discovered that actin (protein that makes up the cell’s skeleton) works with myosin (motor protein) to generate an actin wave that spreads throughout the neuron. The waves of activity reshape the neurite branches until one is selected to become the axon, while the others develop into dendrites. This built-in mechanism helps neurons decide which branch becomes the axon, which is essential for establishing one-way information flow between neurons.
Jon Stoessl, Vesna Sossi, Jeremy Seamans: Functional segregation in Parkinson’s disease
Journal: Science Advances
This study looked at the impact of Parkinson’s disease on the brain’s ability to organize dopamine during different tasks. Researchers mapped task-based dopamine release using positron emission tomography (PET) scans that detect dopamine release while PD and control participants performed motor, cognitive, and reward tasks. They discovered that in PD participants, there was less dopamine release in a basal ganglia structure called the dorsal putamen, which is a structure damaged in patients with PD. Healthy participants displayed distinct patterns of dopamine activity depending on the task and type of movement. For PD participants, organized patterns were disrupted, with dopamine activity across movement and reward areas of the brain. While these changes help the brain compensate and maintain function, they may contribute to challenges in movement and multitasking.
Journal: Neurology
This study examined a rare type of myasthenia gravis (MG), an autoimmune neuromuscular disease, in which patients have antibodies against LRP4, a receptor protein that plays a critical role in neuromuscular formation. Researchers studied a German MG registry of patients, comparing people with LRP4 antibodies to other MG subtypes. They found that patients with only LRP4 antibodies had a distinct form of MG with more severe symptoms, faced greater disease burden and need for advanced treatments compared to MG patients with different or a combination of antibodies.
Naznin Virji-Babul, Shelina Babul: Concussion knowledge, awareness, and experiences of indigenous youth ice hockey players: A call for culturally grounded concussion education and recovery
Journal: Canadian Journal of Public Health
This study used a community-engaged approach called Two-Eyed Seeing to study the knowledge, awareness and lived experiences of Indigenous youth ice hockey players in Canada with respect to concussion. Indigenous youth are disproportionally affected by injuries due to systemic inequities in Canadian healthcare, education and historical mistrust of the system. Researchers examined the intersection between culture, sport and healthcare with concussion education, disclosure and recovery. 48 Indigenous youth hockey players answered a questionnaire and results indicated that many youths delay or avoid reporting injuries due to stigma, minimal or lack of formal education, or understanding the importance of utilizing traditional Indigenous healing methods that are often absent in formal care. Researchers emphasize the importance of supporting Indigenous self-determination through holistic and community-based method within the sport and healthcare system.
Todd Woodward: A Task-Based Functional MRI Double Dissociation of Visual Language and Feature Processing in Healthy Adults
Journal: Journal of Neuroimaging
This study examined functional MRI (fMRI) and its ability to identify different brain configurations of blood-oxygen-level-dependent (BOLD) activity for cognitive functions. Researchers investigated whether fMRI can reliably separate different “cognitive modes” (different ways brains process information) by studying two modes: FoVF (Focus on Visual Features) and LAN (Language). Participants underwent one visual task and one language task, and 10 MRI sessions. Researchers concluded that the tasks revealed a double dissociation, which indicates during one task, the task-induced BOLD activation increased while the other had no significant activation, and vice versa. These results show that fMRI can reliably detect different modes of brain activity linked to specific cognitive functions.
Noah Silverberg, Scott Ramsay: Social Determinants of Health and Symptomatic Recovery from Pediatric Concussion
Journal: Journal of Neurotrauma
This study looks at social determinants of health (SDoH), which are non-medical factors that influence health outcomes including income, education, ethnicity, etc. Researchers examined the relationship between SDoH and post-concussion symptom severity in Canadian children. Through a longitudinal cohort study, children with concussion or orthopedic injury (the control group) and their parents were asked to rate post-concussion symptoms, while researchers examined social factors. Results show that individual SDoH had relatively small effects on post-concussion symptoms, but multiple SDoH and its combined effects are likely an important factor in post-concussion symptom severity.
Teresa Liu-Ambrose: Mapping women’s health and well-being in Canada: A scoping review of findings from the Canadian longitudinal study on aging (CLSA)
Journal: Maturitas
This review looked into the Canadian Longitudinal Study on Aging (CLSA) and its data related to women’s health. Since no review has examined how CLSA data has been used to study women’s health, researchers used this opportunity to examine published studies and identify key research trends, combine their findings, examine sex and gender integration, and highlights gaps and opportunities for improvement. The studies reviewed focused on postmenopausal, pre/perimenopausal and all reproductive stages in females. Researchers concluded that women’s health research using the CLSA data is expanding but is narrowly focused on reproductive health and menopause hormone therapy, and future research should expand beyond the reproductive system and include understudied populations.
Fidel Vila-Rodriguez: Acute neuromodulatory effects of 1 Hz rTMS on the central autonomic network in depression: A concurrent TMS-fMRI study
Journal: Journal of Affective Disorders
Major depressive disorder (MDD) is associated with autonomic dysregulation and dysfunction of the central autonomic network (CAN), the main control system that directs the autonomic nervous system (ANS). Repetitive transcranial magnetic stimulation (rTMS) is an effective non-invasive brain stimulation treatment, for depression and has been shown to change heart rate variability (HRV). However, there is a knowledge gap for how rTMS modulates CAN activity. Researchers looked at MDD patients and examined their brain scans after rTMS. They found that during low frequency rTMS, communication increased between the CAN and the heart and also caused HRV to temporarily decrease. More research is needed to understand how these brain-body changes contribute to improvements in depression.
Cheryl Wellington: Using reference intervals to improve interpretation of youth sport-related concussion biomarkers using a research platform
Journal: Brain Communications
Researchers examined sports-related concussions (SRCs) in adolescents, which are difficult to diagnose due to the variety and subtlety of symptoms. In this study, researchers looked at two biomarkers: neurofilament light (NfL), and glial fibrillary acidic protein (GFAP) to examine whether they can serve as diagnostic tools for SRCs. Researchers examined blood collected from youth before the sports season and up to 28 days after a concussion. They found that levels of both biomarkers increased, but most remained in the normal reference range of NfL and GFAP. These results indicate that NfL and GFAP alone are not suitable to be used as stand-alone diagnostic biomarkers for diagnosing SRCs in youth.
Shernaz Bamji: The GCP16-zDHHC9 S-acyltransferase complex: reciprocal effects on protein S-acylation and stability
Journal: The Journal of Biological Chemistry
This study focuses on how two proteins, zDHHC9 and GCP16, work to regulate a cellular process called S-acylation process, which is essential for the proper function of this protein complex. Researchers found that GCP16 helps the S-acylation and stability of zDHHC9, and vice versa, zDHHC9 enhances the S-acylation process and stabilizes GCP16. They also found that disrupting this interaction prevented dendritic growth in hippocampal neurons, suggesting this complex plays an important role in brain cell development. Overall, this study provides new insights into the mutual regulation of the zDHHC9-GCP16 complex and reveals a role for S-acylation in protecting GCP16 from premature degradation.
