Patterns of facial trauma before and after legalization of marijuana in Denver, Colorado: A joint study between two Denver hospitals.

INTRODUCTION: The effect of marijuana on human health has been studied extensively. Marijuana intoxication has been shown to affect performance, attention span, and reaction time. The public health relationship between trauma and cannabis use has also been studied, with mixed conclusions. In this report, the effect of marijuana legalization on many aspects of facial trauma at two hospitals in Denver, Colorado is examined. METHODS: A retrospective review of the electronic medical records was undertaken. Mann-Whitney U tests were used to compare age of patients before and after legalization, and chi squared analyses were used to compare mechanism of injury, and fracture types before and after recreational marijuana legalization in Denver, Colorado. Geographical location of patients was also considered. RESULTS: No significant increase was found in race before and after marijuana legalization (p=0.19). A significant increase in age was found before (M=39.54,SD=16.37), and after (M=41.38,SD=16.66) legalization (p<0.01). Maxillary and skull base fracture proportions significantly increased following legalization (p<0.001 and p<0.001respectively). No significant differences were seen in the proportion of patients who lived in urban and rural counties before and after legalization (p>0.05). CONCLUSION: Public health efforts should be directed towards educating residents and visitors of Colorado on the effects and toxicology of marijuana. More epidemiologic studies are needed for further assessment of the long-term effects of the legalization of marijuana on the population.

Determinants of precatalytic conformational transitions in the DNA cytosine methyltransferase M.HhaI.

The DNA methyltransferase M.HhaI is an excellent model for understanding how recognition of a nucleic acid substrate is translated into site-specific modification. In this study, we utilize direct, real-time monitoring of the catalytic loop position via engineered tryptophan fluorescence reporters to dissect the conformational transitions that occur in both enzyme and DNA substrate prior to methylation of the target cytosine. Using nucleobase analogues in place of the target and orphan bases, the kinetics of the base flipping and catalytic loop closure rates were determined, revealing that base flipping precedes loop closure as the rate-determining step prior to methyl transfer. To determine the mechanism by which individual specific hydrogen bond contacts at the enzyme-DNA interface mediate these conformational transitions, nucleobase analogues lacking hydrogen bonding groups were incorporated into the recognition sequence to disrupt the major groove recognition elements. The consequences of binding, loop closure, and catalysis were determined for four contacts, revealing large differences in the contribution of individual hydrogen bonds to DNA recognition and conformational transitions on the path to catalysis. Our results describe how M.HhaI utilizes direct readout contacts to accelerate extrication of the target base that offer new insights into the evolutionary history of this important class of enzymes.