Youth cannabis use in Canada post-legalization: service providers' perceptions, practices, and recommendations.

BACKGROUND: In 2018, Canada legalized recreational cannabis use with the purpose of protecting youth and restricting access. However, concerns have been raised that this objective has not been met as rates of cannabis use among youth aged 16-24 have not declined. Youth cannabis use is associated with various adverse effects including psychosis, anxiety, depression, suicidality, respiratory distress, cannabinoid hyperemesis syndrome, and intoxications. Service providers play a crucial role in addressing youth cannabis use. This study aimed to understand Ontario service providers' perceptions, practices, and recommendations on youth cannabis use. METHODS: This mixed method study included a survey and two focus groups. The survey was distributed to mental health service providers serving youth aged 16-24 across Ontario who were given the option to participate in a focus group. The survey included closed and open-ended questions regarding perceptions, practices, and recommendations, while the focus groups explored these categories in greater depth. Descriptive statistics were used to analyze close-ended questions and interpretative content analysis was applied for open-ended questions. Focus group data were analyzed using thematic analysis. RESULTS: The survey was completed by 160 service providers and 12 participated in two focus groups. Regarding perceptions, 60% of survey participants agreed with legalization, 26% had a strong understanding of medical versus recreational cannabis, 84% believed that cannabis has physical and mental health risks, and 49% perceived stigmatization. Less than half of the survey participants reported screening or assessing cannabis use, 16% stated they are highly familiar with treating cannabis use, and 67% reported that they rarely work with families. Subthemes identified in the focus groups under perceptions included normalization and stigmatization, harms for youth, and stigma, racism, and discrimination. Subthemes under practice included cannabis not being the primary focus, challenges with screening, assessment, and intervention, and referral to specialized services. Both the survey and focus group participants recommended increasing public education, enhancing service provider training, improving regulation and policies, reducing stigma and minimization, improving service access, and providing more culturally responsive services. CONCLUSION: Youth cannabis use in Canada remains a significant public health concern, necessitating a more comprehensive plan to protect Ontario youth and reduce associated harms.

Robo2 Receptor Gates the Anatomical Divergence of Neurons Derived From a Common Precursor Origin.

Sensory information relayed to the brain is dependent on complex, yet precise spatial organization of neurons. This anatomical complexity is generated during development from a surprisingly small number of neural stem cell domains. This raises the question of how neurons derived from a common precursor domain respond uniquely to their environment to elaborate correct spatial organization and connectivity. We addressed this question by exploiting genetically labeled mouse embryonic dorsal interneuron 1 (dI1) neurons that are derived from a common precursor domain and give rise to spinal projection neurons with distinct organization of cell bodies with axons projecting either commissurally (dI1c) or ipsilaterally (dI1i). In this study, we examined how the guidance receptor, Robo2, which is a canonical Robo receptor, influenced dI1 guidance during embryonic development. Robo2 was enriched in embryonic dI1i neurons, and loss of Robo2 resulted in misguidance of dI1i axons, whereas dI1c axons remained unperturbed within the mantle zone and ventral commissure. Further, Robo2 profoundly influenced dI1 cell body migration, a feature that was partly dependent on Slit2 signaling. These data suggest that dI1 neurons are dependent on Robo2 for their organization. This work integrated with the field support of a model whereby canonical Robo2 vs. non-canonical Robo3 receptor expression facilitates projection neurons derived from a common precursor domain to read out the tissue environment uniquely giving rise to correct anatomical organization.

Crumbs2 mediates ventricular layer remodelling to form the spinal cord central canal.

In the spinal cord, the central canal forms through a poorly understood process termed dorsal collapse that involves attrition and remodelling of pseudostratified ventricular layer (VL) cells. Here, we use mouse and chick models to show that dorsal ventricular layer (dVL) cells adjacent to dorsal midline Nestin(+) radial glia (dmNes+RG) down-regulate apical polarity proteins, including Crumbs2 (CRB2) and delaminate in a stepwise manner; live imaging shows that as one cell delaminates, the next cell ratchets up, the dmNes+RG endfoot ratchets down, and the process repeats. We show that dmNes+RG secrete a factor that promotes loss of cell polarity and delamination. This activity is mimicked by a secreted variant of Crumbs2 (CRB2S) which is specifically expressed by dmNes+RG. In cultured MDCK cells, CRB2S associates with apical membranes and decreases cell cohesion. Analysis of Crb2F/F/Nestin-Cre+/- mice, and targeted reduction of Crb2/CRB2S in slice cultures reveal essential roles for transmembrane CRB2 (CRB2TM) and CRB2S on VL cells and dmNes+RG, respectively. We propose a model in which a CRB2S-CRB2TM interaction promotes the progressive attrition of the dVL without loss of overall VL integrity. This novel mechanism may operate more widely to promote orderly progenitor delamination.

Evolution of the functionally conserved DCC gene in birds.

Understanding the loss of conserved genes is critical for determining how phenotypic diversity is generated. Here we focus on the evolution of DCC, a gene that encodes a highly conserved neural guidance receptor. Disruption of DCC in animal models and humans results in major neurodevelopmental defects including commissural axon defects. Here we examine DCC evolution in birds, which is of particular interest as a major model system in neurodevelopmental research. We found the DCC containing locus was disrupted several times during evolution, resulting in both gene losses and faster evolution rate of salvaged genes. These data suggest that DCC had been lost independently twice during bird evolution, including in chicken and zebra finch, whereas it was preserved in many other closely related bird species, including ducks. Strikingly, we observed that commissural axon trajectory appeared similar regardless of whether DCC could be detected or not. We conclude that the DCC locus is susceptible to genomic instability leading to independent disruptions in different branches of birds and a significant influence on evolution rate. Overall, the phenomenon of loss or molecular evolution of a highly conserved gene without apparent phenotype change is of conceptual importance for understanding molecular evolution of key biological processes.

Chronic wound audit: evaluation of a tissue viability service.

A chronic wound audit was carried out at the Conquest Hospital, East Sussex, to establish the prevalence of chronic wounds within the Trust, in light of evaluation of the tissue viability service. At the time of audit the Trust employed two specialist nurses on a part time basis (3 days a week) with 2 days clinical work on the wards. A total of 372 patients were included in the audit, 56 patients had a total of 82 chronic wounds. These wounds were subdivided into wound types. The highest numbers of chronic wounds were pressure ulcers grade 1-4, including the new category of moisture lesions totalling 47.5%. Surgical wounds followed at 20.7%. There was a marked reduction in grade 3-4 pressure ulcers consistent with the pressure ulcer prevalence report from August 2006 that saw an overall reduction of hospital acquired pressure ulcers of 3.9%. This was attributed to the purchase of pressure relieving equipment, the development of a pressure ulcer help line and focused education on pressure ulcer prevention throughout the wards. The mean bed stay for both medical and surgical patients was 28.5 bed days but with surgical patients alone median bed stay was a staggering 45.5 days.