At-a-glance - Opioid surveillance: monitoring and responding to the evolving crisis. / Aperçu - Crise des opioïdes : assurer le suivi et faire évoluer les données de surveillance.

The incidence of opioid-related overdoses is increasing at an alarming pace, largely driven by the increased use of fentanyl and its analogues. The need for sound and reliable sources of data on opioid use is crucial in order to make decisions on implementing efficient interventions, and develop appropriate policies and guidelines to mitigate the burden of opioid use. This article highlights initiatives undertaken by federal partners to address the opioid crisis in Canada. The need for novel surveillance approaches that improve the collection and harmonization of drug-related data is also discussed.

RÉSUMÉ: Le nombre de cas de surdoses liées à la consommation d'opioïdes augmente à un rythme alarmant, principalement en raison de l'usage accru du fentanyl et de ses analogues. Des sources de données fiables et solides sur l'utilisation des opioïdes sont cruciales pour la planification d'interventions efficaces, de même que pour l'élaboration de politiques et de directives appropriées en vue de réduire le fardeau des opioïdes. Cet article porte sur les mesures entreprises par les partenaires fédéraux pour s'attaquer à la crise des opioïdes au Canada. Il traite aussi de la nécessité de nouvelles méthodes de surveillance destinées à améliorer la collecte et l'harmonisation des données sur les drogues.

Contribution of methylmercury, polychlorinated biphenyls and organochlorine pesticides to the toxicity of a contaminant mixture based on Canadian Arctic population blood profiles.

Human populations are simultaneously exposed to a variety of anthropogenic contaminants. However, despite extensive literature on animal exposure to single compounds, data on the toxicity of complex mixtures are scarce. The Northern Contaminant Mixture (NCM) was formulated to contain the 27 most abundant contaminants in the same relative proportions found in the blood of Canadian Arctic populations. Sprague-Dawley rat dams were dosed from the first day of gestation until weaning with methylmercury (MeHg), polychlorinated biphenyls (PCBs) or organochlorines pesticides (OCs) administered either separately or together in the NCM. An additional control group for hypothyroxinemia was included by dosing dams with the goitrogen 6-propyl-2-thiouracil (PTU). Offspring growth, survival, serum thyroxine and Thyroid Stimulating Hormone (TSH) levels, thyroid gland morphology, brain taurine content and cerebellum and hippocampus protein expression patterns resulting from such exposures were monitored. Pups' increased mortality rate and impaired growth observed in the NCM treatment group were attributed to MeHg, while decreased circulating thyroxine levels and perturbations of thyroid gland morphology were mostly attributable to PCBs. Interestingly, despite comparable reduction in serum thyroxine levels, PCBs and PTU exposures produced markedly different effects on pup's growth, serum TSH level and brain taurine content. Analysis of cerebellum and hippocampus protein expression patterns corroborated previous cerebellum gene expression data, as contaminant co-exposure in the NCM significantly masked the effects of individual components on protein two-dimensional electrophoresis patterns. Identification by MALDI-TOF/TOF MS of differentially expressed proteins involved notably in neuronal and mitochondrial functions provided clues on the cellular and molecular processes affected by these contaminant mixtures.