Cannabis, alcohol and other drug findings in fatally injured drivers in Ontario.

OBJECTIVE: The purpose of this study was to determine the prevalence of cannabis, alcohol and other drug use in drivers of motor vehicles who died in crashes in the Canadian province of Ontario from January 2016 through December 2018 along with the characteristics of these drivers and some of the circumstances of the crash in which they were involved. METHODS: Toxicological tests were performed on blood samples obtained from 921 driver fatalities for whom postmortem blood samples were submitted to the Center of Forensic Sciences for analysis. The results were coded into a database along with basic demographic and crash characteristics and examined for prominent characteristics and patterns. RESULTS: Overall, among the 921 cases examined, 495 (53.7%) tested positive for alcohol, cannabis (tetrahydrocannabinol or THC), or another psychoactive drug. The number of cases that tested positive for THC (251) exceeded the number of cases that tested positive for alcohol (241) as well as the number that tested positive for a drug other than THC (235). In 38% of positive cases, more than one substance was detected. Alcohol and THC were most commonly detected among males; females most frequently tested positive for a drug other than THC, notably medications with depressant effects. Alcohol-involved driver fatalities were most common on weekends and most likely involved single vehicle crashes. Driver fatalities that tested positive for THC or another drug were more evenly distributed throughout the week and were more likely to have been in multi-vehicle crashes. CONCLUSIONS: The present study highlights the use of cannabis and other drugs by drivers. The patterns of crashes and the characteristics of drivers involved indicate that the characteristics of driver fatalities involving cannabis and/or other drug use differ from those of alcohol and require new, innovative approaches targeting high-risk times, groups and behaviors. Continued monitoring of the toxicological findings from blood samples obtained from drivers killed in motor vehicle crashes will be a key element in efforts to reduce the impact of drug use by drivers on road safety.

Elevated morphine concentrations determined during infant death investigations: artifacts of withdrawal of care.

Three cases are reported of elevated postmortem blood morphine concentrations (189-3036 ng/mL) that were observed during the course of death investigations involving three children ranging in age from 1 week to 2 years, all of whom underwent withdrawal of life support. In all three cases, the presence of opiates in postmortem blood was indicated by immunoassay (ELISA) and quantitative confirmatory analysis of free morphine concentrations in postmortem blood was performed by solid-phase extraction followed by gas chromatography/mass spectrometry (GC/MS) in the selected ion monitoring mode. While the practice of withdrawing life support from terminally ill patients, with the accompanying administration of narcotics/analgesics has been reported in the medical literature, it has not been adequately described in the forensic literature. The implications of this practice on the forensic toxicological interpretation of morphine findings are discussed. To our knowledge, this is the first report of postmortem morphine concentrations arising directly from administration in conjunction with withdrawal of care in pediatric patients.

Discovering novel phenotype-selective neurotrophic factors to treat neurodegenerative diseases.

Astrocytes and neurons in the central nervous system (CNS) interact functionally to mediate processes as diverse as neuroprotection, neurogenesis and synaptogenesis. Moreover, the interaction can be homotypic, implying that astrocyte-derived secreted molecules affect their adjacent neurons optimally vs remote neurons. Astrocytes produce neurotrophic and extracellular matrix molecules that affect neuronal growth, development and survival, synaptic development, stabilization and functioning, and neurogenesis. This new knowledge offers the opportunity of developing astrocyte-derived, secreted proteins as a new class of therapeutics specifically to treat diseases of the CNS. However, primary astrocytes proliferate slowly in vitro, and when induced to immortalize by genetic manipulation, tend to lose their phenotype. These problems have limited the development of astrocytes as sources of potential drug candidates. We have successfully developed a method to induce spontaneous immortalization of astrocytes. Gene expression analysis, karyotyping and activity profiling data show that these spontaneously immortalized type-1 astrocyte cell lines retain the properties of their primary parents. The method is generic, such that cell lines can be prepared from any region of the CNS. To date, a library of 70 cell lines from four regions of the CNS: ventral mesencephalon, striatum, cerebral cortex and hippocampus, has been created. A phenotype-selective neurotrophic factor for dopaminergic neurons has been discovered from one of the cell lines (VMCL1). This mesencephalic astrocyte-derived neurotrophic factor (MANF) is a 20 kD, glycosylated, human secreted protein. Homologs of this protein have been identified in 16 other species including C. elegans. These new developments offer the opportunity of creating a library of astrocyte-derived molecules, and developing the ones with the best therapeutic indices for clinical use.

MANF: a new mesencephalic, astrocyte-derived neurotrophic factor with selectivity for dopaminergic neurons.

We describe the discovery of a novel, 20 kDa, secreted human protein named mesencephalic astrocyte-derived neurotrophic factor, or MANF. The homologous, native molecule was initially derived from a rat mesencephalic type-1 astrocyte cell line and recombinant MANF subcloned from a cDNA encoding human arginine-rich protein. MANF selectively protects nigral dopaminergic neurons, versus GABAergic or serotonergic neurons. The discovery of MANF marks a more systematic approach in the search for astrocyte-derived, secreted proteins that selectively protect specific neuronal phenotypes. Compared to glial cell line-derived neurotrophic factor (GDNF) and brain-derived neurotrophic factor (BDNF), MANF was more selective in the protection of dopaminergic neurons at lower (0.05-0.25 ng/mL) and middle (0.5-2.5 ng/mL) concentrations: MANF>GDNF>BDNF. GDNF was more selective at higher concentrations (25-50 ng/ml): GDNF>MANF>BDNF. Two domains in MANF of 39-AA and 109-AA respectively, and eight cysteines are conserved from C. elegans to man. MANF is encoded by a 4.3 Kb gene with 4 exons, and is located on the short arm of human chromosome 3. The secondary structure is dominated by alpha-helices (47%) and random coils (37%). Studies to determine the localization of MANF in the brains of rat, monkey, and man, as well as the receptor, signaling pathways, and biologically active peptide mimetics are in progress. The selective, neuroprotective effect of MANF for dopaminergic neurons suggests that it may be indicated for the treatment of Parkinson's disease.