Faculty prefer continuity with medical students in the emergency department.

INTRODUCTION: The aim of this investigation was to better understand emergency medicine (EM) faculty opinions as they relate to continuity with students. METHODS: This was a prospective cohort study of faculty supervising students completing an EM clerkship. Student schedules were aligned to maximise continuity with faculty. Faculty completed surveys prior to the start of the study and again at the end of the study period. RESULTS: Faculty generally indicated a favourable opinion regarding continuity with students. Significant change was noted in two survey questions from pre- to post-intervention: faculty reported higher motivation to teach and felt the students' learning experience was better with improved continuity. CONCLUSION: EM faculty express theoretical optimism regarding the value of improved continuity between teacher and learner. This positive sentiment persisted after actual experience with students on a shift allocation model that aligns faculty and student schedules.

Team Approach: Treatment of Traumatic Dislocations of the Knee.

¼: Traumatic knee dislocations are complex injuries that can be associated with compromise of the neurovascular structures about the knee. ¼: Various classification systems for knee dislocations exist in the literature but should be used with caution as a prognostic tool because many knee dislocations fit into more than 1 category. ¼: Special populations of knee dislocations, such as obese patients and high-velocity mechanism injuries, require additional caution during the initial evaluation for possible vascular injuries.

ß-Glucans inhibit intracellular growth of Mycobacterium bovis BCG but not virulent Mycobacterium tuberculosis in human macrophages.

The yeast polysaccharide, ß-glucan, has been shown to promote both anti-microbial and anti-tumor activities through its interaction with macrophages. Here we analyzed the effects of an insoluble whole glucan particle (WGP), a 1,3/1,6-ß-glucan from Saccharomyces cerevisiae, and a soluble poly-1-6-ß-d-glucopyranosyl-1-3-ß-d-glucopyranose (PGG), a hydrolytic product of WGP, on the anti-microbial response of human macrophages against mycobacterial infection. Treatment of macrophages with WGP and PGG significantly decreased cell association and intracellular growth of Mycobacterium bovis BCG, but not Mycobacterium tuberculosis (M.tb) when compared to untreated controls. We characterized the influence of ß-glucans on the generation of macrophage oxidative products and pro-inflammatory cytokines, two important anti-microbial defense mechanisms. WGP but not PGG treatment enhanced the oxidative response of macrophages as determined by the 2',7'-dichlorofluorescin (DCF) assay. WGP treatment also induced macrophages to produce pro-inflammatory cytokines. The ß-glucan receptor, Dectin-1, was found to be involved in the WGP-induced macrophage oxidative burst and intracellular growth inhibition of M. bovis BCG. This report indicates that although some forms of ß-glucan are able to stimulate the respiratory burst and cytokine production in human macrophages, and exhibit anti-microbial properties against M. bovis BCG, the ß-glucans tested here did not inhibit growth of M.tb within human macrophages.

Characterization of clinical and environmental Mycobacterium avium spp. isolates and their interaction with human macrophages.

Members of the Mycobacterium avium complex (MAC) are naturally occurring bacteria in the environment. A link has been suggested between M. avium strains in drinking water and clinical isolates from infected individuals. There is a need to develop new screening methodologies that can identify specific virulence properties of M. avium isolates found in water that predict a level of risk to exposed individuals. In this work we have characterized 15 clinical and environmental M. avium spp. isolates provided by the US Environmental Protection Agency (EPA) to improve our understanding of the key processes involved in the binding, uptake and survival of these isolates in primary human macrophages. M. avium serovar 8 was predominant among the isolates studied. Different amounts and exposure of mannose-capped lipoarabinomannan (ManLAM) and glycopeptidolipids (GPLs), both major mycobacterial virulence factors, were found among the isolates studied. Reference clinical isolate 104 serovar 1 and clinical isolates 11 and 14 serovar 8 showed an increased association with macrophages. Serum opsonization increased the cell association and survival at 2 h post infection for all isolates. However, only the clinical isolates 104 and 3 among those tested showed an increased growth in primary human macrophages. The other isolates varied in their survival in these cells. Thus we conclude that the amounts of cell envelope ManLAM and GPL, as well as GPL serovar specificity are not the only important bacterial factors for dictating the early interactions of M. avium with human macrophages.