Institute of Biochemistry

Verotoxin-producing Escherichia coli (VTEC) present a significant risk of foodborne illness and severe patient outcomes. Isolation is laborious and time consuming due to the diversity of strains. Development of a differential agent wouldenhance rate and speed of isolation. Production of verotoxin (VT) is the only phenotypic trait exclusive to VTEC. Aptamers are single-stranded oligonucleotides with high selectivity and affinity for their targets. A VT-targeting aptamer beacon could aid in isolation of VTEC. Proof of concept was demonstrated using an existing aptamer sequence, showing increased fluorescence in the presence of VT1a. Further characterization showed target specificity, but weaker signal contrast in complex media. Comparison of fluorophore-quencher pairs showed Texas Red and Black Hole Quenchers as optimal choices. Finally, a DNA substrate developed to detect VT enzyme activity produced weak fluorescent signalmaking it unlikely to aid in detection.

Exercise-induced arterial hypoxemia (EIAH), defined as a significant decrease in oxygen saturation (<95%) during maximal and sub-maximal exercise, is a phenomenon observed in moderately and highly trained athletes. The consequences of EIAH on exercise performance relate to its negative influence on maximal O2 uptake (VO2 max) and impairment of oxygen delivery. The causes of EIAH are yet to be completely elucidated. Proposed mechanisms include ventilation/perfusion inequality, relative alveolar hypoventilation, right-to-left shunt, and diffusion limitation. We hypothesized that development of interstitial pulmonary edema during maximal exercise triggers the physiological mechanisms leading to EIAH. Eleven subjects, who had previously developed EIAH during a similar testing protocol, performed an incremental cycling or running protocol to exhaustion, and pre- and post-exercise lungs scanned using computed tomography. Scans were analyzed both qualitatively and quantitatively for the...

Results A total of 392 patients were randomized (mean age 53.9 10.3 years); 83.5% were male; 64.9% had STsegment elevation myocardial infarction). Patients smoked a mean of 23.2 10.6 cigarettes/day for a mean of 32.9 12.4 years. At 12 months, point prevalence abstinence rates were 37.2% in the bupropion group and 32.0% in the placebo group (p 0.33; % difference after adjusting for between center differences 3.9%). Continuous abstinence rates were 26.8% and 22.2%, respectively (p 0.34). Major adverse cardiac event rates were similar (13.0% vs. 11.0%, respectively; p 0.64).

Hyponatremia among marathon runners and endurance athletes has become an emerging topic for research and public concern following reports of serious illness and death. Weight gain due to excessive fluid consumption during the marathon race was proposed to be a major factor in the development of hyponatremia. We hypothesized that hyponatremia immediately following marathon completion is less common than previously reported and that post race fluid consumption is a critical factor in the development of hyponatremia. Blood, urine samples and body weight were collected up to 2 hours prior to start of the race, at race completion and at 1 hour after the race in 133 full and half marathon runners. At the race finish, each runner completed a brief questionnaire documenting consumption of fluids during the race. Serum sodium for all participants slightly increased from baseline (141.0±1.72 mmol/L) to race completion (141.8±3.09 mmol/L; p=0.0154), but significantly reduced one hour after rac...

Patients with severe chronic obstructive pulmonary disease (COPD) commonly develop weight loss, muscle wasting, and consequently poor survival. Nutritional supplementation and ana-bolic steroids increase lean body mass, improve muscle strength, and survival in patients enrolled in comprehensive rehabilitation programs. Whether anabolic steroids are effective out-side an intensive rehabilitation program is not known. We conducted a prospective, double-blind, placebo-controlled, 16-week trial to study the benefits of anabolic steroids in patients with severe COPD who did not participate in a structured rehabilitation program. Biweekly intramuscular injections of either the drug (nandrolone decanoate) or placebo were adminis-tered. Sixteen patients with severe COPD were randomized to either placebo or nandrolone decanoate. The placebo group weighed 55.32 ± 11.33 kg at baseline and 54.15 ± 10.80 kg at 16 weeks; the treatment group weighed 68.80 ± 6.58 at baseline and 67.92 ± 6.73 at 16 ...

Exercise-induced arterial hypoxemia (EIAH) is a recognized phenomenon in healthy subjects, although its epidemiology and mechanisms remain incompletely understood. In this study, we assessed the prevalence rates of EIAH among various populations. Eighty-two subjects underwent incremental exercise protocols to maximum volitional fatigue while being monitored using forehead pulse oximetry. Pre-and post-exercise spirometric testing as well as serum lactate measurements were utilized. Results were stratified by severity of oxygen desaturation, gender, age, training, fitness level, and mode of exercise, and statistically compared to determine EIAH prevalence and characteristics of the desaturating populations. The prevalence of EIAH in our study population was 35.4% (37.1% for males and 30% for females), which was significantly lower than that reported previously. We additionally observed a higher prevalence of EIAH in moderately fit individuals than previously documented (32.7%) and a l...

Exercise-induced arterial hypoxemia (EIAH) is a recognized phenomenon in healthy subjects, although its epidemiology and mechanisms remain incompletely understood. In this study, we assessed the prevalence rates of EIAH among various populations and further explored whether expiratory flow limitation plays a role in its causation. Eighty-two subjects underwent incremental exercise protocols to maximum volitional fatigue while being monitored using forehead pulse oximetry. Pre-and post-exercise spirometric tests were employed to detect evidence of airway hyper-responsiveness and expiratory flow limitation. Results were stratified by severity of oxygen desaturation, gender, age, training, fitness level, and mode of exercise, and statistically compared to determine EIAH prevalence and characteristics of the desaturating populations. The prevalence of EIAH in our study population was 35.4% (37.1% for males and 30% for females), which was significantly lower than that reported previously. We additionally observed a higher prevalence of EIAH in moderately fit individuals than previously documented (32.7%) and lower prevalence in the least trained subjects (36.8% vs. 12.5%). Younger subjects displayed a trend towards greater development of EIAH. Spirometric analysis revealed no statistically significant differences in lung volumes and flow rates between individuals with normal saturation and those who displayed desaturation. Our documented prevalence of EIAH is significantly lower, but more common in less fit and younger individuals, compared to previously published findings. Moreover, our results do not support the theory that expiratory flow limitation is a major contributory mechanism in the development of EIAH.

Web based Curriculum Management Systems (CMS) are increasingly utilized to deliver medical education across Canadian and other Universities. CMS can facilitate the delivery of learning resources, broadens the capacity for tracking and reporting of teaching & learning across an institution, simplify and automate administrative and supervisory tasks, and serve a useful function for institutional accreditation. Some of these systems are equipped with business intelligence tools to analyze data and create reports to facilitate curriculum governance and education delivery. These intelligence reports can improve curriculum governance and are expected to be immensely advantageous while preparing for medical school accreditation visits. At University of Manitoba, we have been using Online Portal for Advanced Learning (OPAL) to generate reports to find missing sessions, learning objectives, resource uploading and instructor assignment during the pre clerkship year. In this paper, we demonstr...