Rishad Khan

Autophagy gene fingerprint in human ischemia and reperfusion

OBJECTIVE Autophagy is an evolutionary conserved adaptive response that is believed to promote cell survival in response to stressful stimuli via recycling of precursors derived from the degradation of endogenous cellular components. The autophagic molecular machinery is controlled by a large family of autophagy-related genes (ATGs) and downstream regulators. We sought to define the autophagy gene fingerprint associated with human ischemia and reperfusion (IR) injury using an intraoperative model developed by Sellke and colleagues. METHODS Right atrial appendages, collected from human hearts before and after cardioplegic arrest and after reperfusion, were submitted for polymerase chain reaction (PCR) array, quantitative real-time PCR, and immunoblot analysis for autophagy proteins and their associated upstream regulators. RESULTS Perioperative IR significantly upregulated 11 (13.1%) and downregulated 3 (3.6%) of 84 ATGs. Specifically, there were increases in the autophagy machinery components ATG4A, ATG4C, and ATG4D; tumor necrosis factor-related apoptosis-inducing ligand, MAPK8 and BCL2L1; and chaperone-mediated autophagy activity with increased heat shock protein (HSP) A8, HSP90AA1, and a-synuclein. Autophagy activity was confirmed through observations of higher LC3-I levels and an increase in the LC3-II/LC3-I ratio. Autophagy activation coincided with increased AMPK activation and decreased protein levels of the mammalian target of rapamycin, the latter a key negative regulator of autophagy. CONCLUSIONS We provide the first human cardiac fingerprint of autophagy gene expression in response to IR. These findings may inform on appropriate cell- and gene-based therapeutic approaches to limit aberrant cardiac injury.

BRCA1 shields vascular smooth muscle cells from oxidative stress

BACKGROUND Excessive production of reactive oxygen species (ROS), in part via upregulation of DNA damage pathways, is a central mechanism governing pathologic activation of vascular smooth muscle cells (VSMCs). We hypothesized that the breast cancer 1, early onset (BRCA1) gene that is involved in cellular resistance to DNA damage limits ROS production and oxidative stress in VSMCs. METHODS We evaluated basal and H2O2-stimulated expression of BRCA1 in human aortic smooth muscle cells (HASMCs). In vitro gain-of-function experiments were performed in BRCA1 adenovirus (Ad-BRCA1)-transfected HASMCs. ROS production and expression of Nox1 and its key regulatory subunit p47phox, key components of the ROS-generating nicotinamide adenine dinucleotide phosphate (NADPH) oxidase system, were evaluated. In vivo gain-of-function experiments were performed in spontaneously hypertensive (SHR) rats treated with Ad-BRCA1 (5 × 10(10) IU/rat). Blood pressure, vascular ROS generation, Nox1, and p47phox expression were measured. RESULTS BRCA1 was constitutively expressed in murine, rat, and human smooth muscle cells (SMCs). H2O2 significantly reduced BRCA1 expression with a resultant increase in ROS generation. BRCA1-overexpressing HASMCs were protected against H2O2-induced ROS generation, in part, via downregulation of the ROS-producing NADPH oxidase subunits Nox1 and p47phox. Ad-BRCA1 treatment in SHR rats was associated with a sustained increase in aortic BRCA1 expression, lower aortic ROS production, reduced γH2A.X levels, greater RAD51 foci, and decreases in blood pressure. CONCLUSIONS BRCA1 is a novel and previously unrecognized target that may shield VSMCs from oxidative stress by inhibiting NADPH Nox1-dependent ROS production. Gene- and/or cell-based approaches that improve BRCA1 bioavailability may represent a new approach in the treatment of diverse vascular diseases associated with an aberrant VSMC phenotype.

Peer assessment in the objective structured clinical examination: A scoping review

Abstract Background: The objective structured clinical examination (OSCE), originally designed with experts assessing trainees’ competence, is more frequently employed with an element of peer assessment and feedback. Although peer assessment in higher education has been studied, its role in OSCEs has not reviewed. Aims: The aim of this study is to conduct a scoping review and explore the role of peer assessment and feedback in the OSCE. Methods: Electronic database and hand searching yielded 507 articles. Twenty-one full records were screened, of which 13 were included in the review. Two independent reviewers completed each step of the review. Results: Peer-based OSCEs are used to assess students’ accuracy in assessing OSCE performance and to promote learning. Peer examiners (PE) tend to award better global ratings and variable checklist ratings compared to faculty and provide high-quality feedback. Participating in these OSCEs is perceived as beneficial for learning. Conclusions: Peer assessment and feedback can be used to gauge PE reliability and promote learning. Teachers using these OSCEs must use methodology which fits their purpose. Competency-based education calls for diversification of assessment practices and asks how assessment impacts learning; the peer-based OSCE responds to these demands and will become an important practice in health professions education.

Simulation-Based Training of Non-Technical Skills in Colonoscopy: Protocol for a Randomized Controlled Trial

Background Non-technical skills (NTS), such as communication and professionalism, contribute to the safe and effective completion of procedures. NTS training has previously been shown to improve surgical performance. Moreover, increases in NTS have been associated with improved clinical endoscopic performance. Despite this evidence, NTS training has not been tested as an intervention in endoscopy. Objective The aim of this study is to evaluate the effectiveness of a simulation-based training (SBT) curriculum of NTS on novice endoscopists’ performance of clinical colonoscopy. Methods Novice endoscopists were randomized to 2 groups. The control group received 4 hours of interactive didactic sessions on colonoscopy theory and 6 hours of SBT. Hours 5 and 6 of the SBT were integrated scenarios, wherein participants interacted with a standardized patient and nurse, while performing a colonoscopy on the virtual reality (VR) simulator. The NTS (intervention) group received the same teaching sessions but the last hour was focused on NTS teaching. The NTS group also reviewed a checklist of tasks relevant to NTS concepts prior to each integrated scenario case and was provided with dedicated feedback on their NTS performance during the integrated scenario practice. All participants were assessed at baseline, immediately after training, and 4 to 6 weeks post-training. The primary outcome measure is colonoscopy-specific performance in the clinical setting. Results In total, 42 novice endoscopists completed the study. Data collection and analysis is ongoing. We anticipate completion of all assessments by August 2017. Data analysis, manuscript writing, and subsequent submission for publication is expected to be completed by December 2017. Conclusions Results from this study may inform the implementation of NTS training into postgraduate gastrointestinal curricula. NTS curricula may improve attitudes towards patient safety and self-reflection among trainees. Moreover, enhanced NTS may lead to superior clinical performance and outcomes in colonoscopy. Trial Registration Clinicaltrial.gov NCT02877420; https://www.clinicaltrials.gov/ct2/show/NCT02877420 (Archived by WebCite at http://www.webcitation.org/6rw94ubXX NCT02877420)

Aseptic Abscesses and Inflammatory Bowel Disease: Two Cases and Review of Literature

Background. Aseptic abscesses (AA) are sterile lesions that represent an extraintestinal manifestation (EIM) of inflammatory bowel disease (IBD). Though Canada has the highest prevalence of IBD in the world, reports of IBD-associated AA are absent in Canada. This may represent a different IBD phenotype or underrecognition and underreporting. Purpose. To explore AA as a possible EIM of IBD and evaluate clinical and investigative findings among patients with IBD-associated AA. Methods. Retrospective chart and literature reviews were performed to find cases of IBD-associated AA at our institution and in the literature. Results. We identified 2 cases of IBD-associated AA in our institution. Both patients had ulcerative colitis and presented with fever, abdominal pain, and weight loss. Radiological workup and aspiration showed sterile splenic abscesses. The AA were unresponsive to antibiotics. One patient improved on corticosteroids and one underwent splenectomy. We retrieved 37 cases of IBD-associated AA from the literature. All patients showed no evidence of infection, failed to resolve with antibiotics, and, if attempted, improved on corticosteroids. Conclusions. Our cases are the first reported in Canada. They support literature which suggests AA as an EIM of IBD and may help increase recognition and reporting of this phenomenon.