Faculty Bibliography

Although abdominal pain is a common chief complaint in the emergency department, only 1 in 6 patients with abdominal pain are diagnosed with a gastrointestinal (GI) emergency. These patients often undergo extensive testing as well as hospitalizations to rule out an acute GI emergency and there is evidence that not all patients benefit from such management. Several clinical decision rules (CDRs) have been developed for the diagnosis and management of patients with suspected acute appendicitis and upper GI bleeding to identify those patients who may safely forgo further testing or hospital admission. Further validation studies demonstrating the superiority of these CDRs over contemporary practice are needed.

BACKGROUND:Self-stigma is highly prevalent in serious mental illness (SMI) and is associated with poorer clinical and functional outcomes. Narrative enhancement and cognitive therapy (NECT) is a group-based intervention combining psychoeducation, cognitive restructuring and story-telling exercises to reduce self-stigma and its impact on recovery-related outcomes. Despite evidence of its effectiveness on self-stigma in schizophrenia-related disorders, it is unclear whether NECT can impact social functioning. METHODS:This is a 12-centre stepped-wedge cluster randomized controlled trial of NECT effectiveness on social functioning in SMI, compared to treatment as usual. One hundred and twenty participants diagnosed with schizophrenia, bipolar disorder or borderline personality disorder will be recruited across the 12 sites. The 12 centres participating to the study will be randomized into two groups: one group (group 1) receiving the intervention at the beginning of the study (T0) and one group (group 2) being a control group for the first 6 months and receiving the intervention after (T1). Outcomes will be compared in both groups at T0 and T1, and 6-month and 12-month outcomes for groups 1 and 2 will be measured without a control group at T2 (to evaluate the stability of the effects over time). Evaluations will be conducted by assessors blind to treatment allocation. The primary outcome is personal and social performance compared across randomization groups. Secondary outcomes include self-stigma, self-esteem, wellbeing, quality of life, illness severity, depressive symptoms and personal recovery. DISCUSSION/CONCLUSIONS:NECT is a promising intervention for reducing self-stigma and improving recovery-related outcomes in SMI. If shown to be effective in this trial, it is likely that NECT will be implemented in psychiatric rehabilitation services with subsequent implications for routine clinical practice. TRIAL REGISTRATION/BACKGROUND:ClinicalTrials.gov NCT03972735 . Trial registration date 31 May 2019.

Expression of the lysis cassette (essD, ybcT, rzpD/rzoD) from the defective lambdoid prophage at the 12th minute of Escherichia coli's genome (DLP12) is required in some strains for proper curli expression and biofilm formation. Regulating production of the lytic enzymes encoded by these genes is critical for maintaining cell wall integrity. In lambdoid phages, late-gene regulation is mediated by the vegetative sigma factor RpoD and the lambda antiterminator Qλ. We previously demonstrated that DLP12 contains a Q-like protein (QDLP12) that positively regulates transcription of the lysis cassette, but the sigma factor responsible for this transcription initiation remained to be elucidated. In silico analysis of essDp revealed the presence of a putative - 35 and - 10 sigma site recognized by the extracytoplasmic stress response sigma factor, RpoE. In this work, we report that RpoE overexpression promoted transcription from essDp in vivo, and in vitro using purified RNAP. We demonstrate that the - 35 region is important for RpoE binding in vitro and that this region is also important for QDLP12-mediated transcription of essDp in vivo. A bacterial two-hybrid assay indicated that QDLP12 and RpoE physically interact in vivo, consistent with what is seen for Qλ and RpoD. We propose that RpoE regulates transcription of the DLP12 lysis genes through interaction with QDLP12 and that proper expression is dependent on an intact - 35 sigma region in essDp. This work provides evidence that the unique Q-dependent regulatory mechanism of lambdoid phages has been co-opted by E. coli harbouring defective DLP12 and has been integrated into the tightly controlled RpoE regulon.

In cell culture, when cells are inoculated into fresh media, there can be a period of slow (or lag phase) growth followed by a transition to exponential growth. This period of slow growth is usually attributed to the cells' adaptation to a new environment. However, we argue that, based on observations of shaken suspension culture of Dictyostelium discoideum, a model single-cell eukaryote, this transition is due to a density effect. Attempts to demonstrate the existence of implicit cell signaling via long-range diffusible messengers (i.e., soluble growth factors) through cell-medium separation and microfluidic flow perturbation experiments produced negative results. This, in turn, led to the development of a signaling model based on direct cell-to-cell contacts. Employing a scaling argument for the collision rate due to fluid shear, we reasonably estimate the crossover density for the transition into the exponential phase and fit the observed growth kinetics.