Charles N Bernstein

University of Manitoba, Winnipeg, Manitoba, Canada

Are you Charles N Bernstein?

Claim your profile

Publications (400)2743.89 Total impact

  • Canadian journal of gastroenterology & hepatology. 07/2014; 28(7):371-372.
  • [Show abstract] [Hide abstract]
    ABSTRACT: To compare the incidence of, and mortality after, intensive care unit (ICU) admission as well as the characteristics of critical illness in the multiple sclerosis (MS) population vs the general population. We used population-based administrative data from the Canadian province of Manitoba for the period 1984 to 2010 and clinical data from 93% of admissions to provincial high-intensity adult ICUs. We identified 5,035 prevalent cases of MS and a cohort from the general population matched 5:1 on age, sex, and region of residence. We compared these populations using incidence rates and multivariable regression models adjusting for age, sex, comorbidity, and socioeconomic status. From January 2000 to October 2009, the age- and sex-standardized annual incidence of ICU admission among prevalent cohorts was 0.51% to 1.07% in the MS population and 0.34% to 0.51% in matched controls. The adjusted risk of ICU admission was higher for the MS population (hazard ratio 1.45; 95% confidence interval [CI] 1.19-1.75) than for matched controls. The MS population was more likely to be admitted for infection than the matched controls (odds ratio 1.82; 95% CI 1.10-1.32). Compared with the matched controls admitted to ICUs, 1-year mortality was higher in the MS population (relative risk 2.06; 95% CI 1.32-3.07) and was particularly elevated in patients with MS who were younger than 40 years (relative risk 3.77; 95% CI 1.45-8.11). Causes of death were MS (9.3%), infections (37.0%), and other causes (52.9%). Compared with the general population, the risk of ICU admission is higher in MS, and 1-year mortality after admission is higher. Greater attention to preventing infection and managing comorbidity is needed in the MS population.
    Neurology 05/2014; · 8.25 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: SLC22A23 is an orphan gene in the SLC22 family of organic membrane transporters, and its single-nucleotide polymorphism rs17309827-T was recently nominally associated with intestinal inflammation in a genome-wide association study. Other polymorphisms in the SLC22A23 gene have been associated with diseases with an inflammatory component, and polymorphisms in related genes in the SLC22 family have been repeatedly associated with inflammatory bowel disease (IBD). In a candidate-gene study using a well-phenotyped, highly monitored, Manitoban white cohort, we investigated whether variations in SLC22A23 were associated with intestinal inflammation. Selected genetic variations were genotyped by using fluorescent-based assays or a polymerase chain reaction-restriction fragment length polymorphism analysis in 160 individuals with Crohn disease, 149 individuals with ulcerative colitis, and 142 healthy control subjects to determine genetic associations. Homozygocity for single-nucleotide polymorphisms rs4959235-TT and rs950318-GG was associated with IBD, whereby 6% of patients (18 of 311 cases) carried these genotypes, but they were not seen in healthy controls. Associations reported in this article add to the emerging evidence that SLC22A23 variants could modify IBD risk. However, the biology of the gene and impact of variations on the gene's functions need to be tested to validate a causative role.
    American Journal of Clinical Nutrition 04/2014; · 6.50 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Little is known about how often, and for what reasons, patients with inflammatory bowel diseases (IBD) are admitted to the intensive care unit (ICU). We compared incidences of ICU admission, characteristics of critical illness, and mortality after ICU admission between patients with IBD and the general population. We identified all persons with IBD in the province of Manitoba using a validated administrative definition of IBD for the period 1984 to 2010. Cases were considered incident for IBD if their first health system contact for IBD was in 1989 or later. We identified a population-based control group, matched by age, sex, and geography (based on postal code). Case and control cohorts were linked to the Manitoba ICU database. We compared outcomes between groups using age- and sex-standardized rates, Cox proportional hazards models, and logistic regression models, adjusting for age, sex, comorbidity, and socioeconomic status. There were 8224 prevalent and 4580 incident cases of IBD. After adjustment, the risk for ICU admission was higher for patients with IBD than controls (hazard ratio [HR], 1.79; 1.58-2.02). The risk of ICU admission was higher for patients with Crohn's disease (HR, 2.31; 1.95-2.75) than ulcerative colitis (HR, 1.37; 1.13-1.65). From 2000 through 2010, age- and sex-standardized annual incidence rates for ICU admission in the prevalent IBD cohort ranged from 0.55% to 1.12%. Compared to controls admitted to ICUs, 1 year after ICU admission, mortality was 32% among patients with IBD. Patients with IBD have a higher risk for admission to the ICU than the general population, and increased mortality 1 year after admission. These findings underscore the potential severity of IBD.
    Clinical gastroenterology and hepatology: the official clinical practice journal of the American Gastroenterological Association 04/2014; · 5.64 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To evaluate the reporting and performance of colonoscopy in a large urban centre. Colonoscopies performed between January and April 2008 in community hospitals and academic centres in the Winnipeg Regional Health Authority (Manitoba) were identified from hospital discharge databases and retrospective review of a random sample of identified charts. Information regarding reporting of colonoscopies (including bowel preparation, photodocumentation of cecum⁄ileum, size, site, characteristics and method of polyp removal), colonoscopy completion rates and follow-up recommendations was extracted. Colonoscopy completion rates were compared among different groups of physicians. A total of 797 colonoscopies were evaluated. Several deficiencies in reporting were identified. For example, bowel preparation quality was reported in only 20%, the agent used for bowel preparation was recorded in 50%, photodocumentation of colonoscopy completion in 6% and polyp appearance (ie, pedunculated or not) in 34%, and polyp size in 66%. Although the overall colonoscopy completion rate was 92%, there was a significant difference among physicians with varying medical specialty training and volume of procedures performed. Recommendations for follow-up procedures (barium enema, computed tomography colonography or repeat colonoscopy) were recorded for a minority of individuals with reported poor bowel preparation or incomplete colonoscopy. The present study found many deficiencies in reporting of colonoscopy in typical, city-wide clinical practices. Colonoscopy completion rates varied among different physician specialties. There is an urgent need to adopt standardized colonoscopy reporting systems in everyday practice and to provide feedback to physicians regarding deficiencies so they can be rectified.
    Canadian journal of gastroenterology & hepatology. 04/2014; 28(4):185-90.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Mucosal inflammation in patients with inflammatory bowel disease (IBD) is characterized by an alteration of prohormone Chromogranin A (CgA) production. The recent demonstration of an implication of CgA in collagenous colitis and immune regulation provides a potential link between CgA-derived peptides (catestatin, CTS) and gut inflammation. Colitis was induced by administration of dextran sulfate sodium or 2, 4 dinitrobenzenesulfonic acid to C57BL/6 mice. Treatment with human (h)CTS or its proximal or distal part was started one day before colitis induction and colonic inflammatory markers were determined. Pro-inflammatory cytokines were evaluated in peritoneal isolated and bone marrow derived macrophages (BMDMs); p-STAT3 level was studied. Serum levels of CgA and CTS were assessed in experimental colitis and in a separate study in IBD patients and healthy controls. We show that sera from IBD patients and that in experimental colitis conditions the colonic level of mouse (m)CgA and mCTS are significantly increased. Moreover, in vivo treatment with human (h)CTS reduces the disease onset and suppresses exacerbated inflammatory responses in preclinical settings of colitis associated with an increase of p-STAT3. In vitro, hCTS treatment decreases proinflammatory cytokine release by peritoneal macrophages and BMDMs and increases p-STAT3 levels. These results support the hypothesis that CTS is increased during colitis and that hCTS modulates intestinal inflammation via the macrophage population and through a STAT-3 dependent pathway in a murine model of colitis. Identification of the molecular mechanism underlying the protective role of this peptide may lead to a novel therapeutic option in IBD.
    Biochemical pharmacology 03/2014; · 4.25 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Corticosteroids are widely used in the management of inflammatory bowel disease (IBD) and are associated with significant side effects. The real world effectiveness of newer drug therapies at reducing corticosteroid use is yet to be reported. The overall burden of corticosteroid use is poorly characterized. We used a population-based IBD database to evaluate the overall prevalence of corticosteroid exposure, corticosteroid-free survival, and heavy corticosteroid use (≥3000 mg of prednisone or equivalent in a 365-day period). Regression models were used to assess predictors of heavy corticosteroid use and the relationship between corticosteroid dose in the first year after diagnosis and the need for continued corticosteroid use and surgery. The proportion of persons with IBD prescribed corticosteroids within 1, 5, and 10 years of diagnosis was 35.2%, 52.0%, and 62.8%, respectively. Persons with ulcerative colitis, males, and diagnosis before age 25 were more likely to use corticosteroids and have higher cumulative exposure. Heavy corticosteroid use in the first year after IBD diagnosis was associated with a 3 times increased hazard of resective surgery. Cumulative corticosteroid exposure did not decrease among those diagnosed with IBD in more recent years, despite increasing use of immunomodulators. A plurality of IBD patients will be exposed to corticosteroids over the course of disease, mostly in the first year. Heavy corticosteroid use in the first year of IBD is a strong predictor of subsequent surgery. Cumulative exposure to corticosteroids use is not decreasing despite increasing uptake of immunomodulators.
    Inflammatory Bowel Diseases 02/2014; · 5.12 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: & Aims: Guidelines for the management of venous thromboembolism (VTE) from the American College of Chest Physicians do not address patients with inflammatory bowel disease (IBD), a group with a high risk of both VTE and gastrointestinal bleeding. We present recommendations for the prevention and treatment of VTE in patients with IBD. A systematic literature search was performed to identify studies on VTE in IBD. The quality of evidence and strength of recommendations were rated according to the Grading of Recommendation Assessment, Development, and Evaluation (GRADE) approach. Statements were developed through an iterative online platform, then finalized and voted on by a working group of adult and pediatric gastroenterologists and thrombosis specialists. IBD patients have an approximately 3-fold higher risk of VTE compared with individuals without IBD, and disease flares further increase this risk. Anticoagulant thromboprophylaxis is recommended for IBD patients who are hospitalized with IBD flares without active bleeding and is suggested when bleeding is nonsevere. Anticoagulant thromboprophylaxis is suggested during moderate-severe IBD flares in outpatients with a history of VTE provoked by an IBD flare or an unprovoked VTE, but not otherwise. The recommended duration of anticoagulation after a first VTE is based on the presence of provoking factors. Specific suggestions are made for the prevention and treatment of VTE in pediatric and pregnant IBD patients. Using the American College of Chest Physicians' guidelines as a foundation, we have integrated evidence from IBD studies to develop specific recommendations for the management of VTE in this high-risk population.
    Gastroenterology 01/2014; · 12.82 Impact Factor
  • Laura E Targownik, Charles N Bernstein, William D Leslie
    [Show abstract] [Hide abstract]
    ABSTRACT: To provide a synopsis on established and new research evaluating bone disease in patients with inflammatory bowel disease (IBD) RECENT FINDINGS: Persons with IBD, including Crohn's disease and ulcerative colitis are believed to be at high risk for osteoporosis and fracture. As osteoporosis is clinically silent and persons with IBD are not universally screened, the burden of bone disease in IBD has been difficult to accurately assess. It is also unclear whether bone disease is due to inflammatory activity, medication use, poor nutrient intake/absorption, or body habitus characteristics. Recent studies using population-wide databases of bone mineral density (BMD) analyses suggest that Crohn's disease is responsible for a small effect on BMD after adjusting for other risk factors for low BMD, whereas ulcerative colitis does not appear to confer an independent risk. Furthermore, IBD does not appear to be a risk for overall fracture once controlling for factors which are associated with both IBD and fracture risk. The ability to assess BMD on incidentally performed computed tomography scans may allow detection of low BMD in IBD patients. Although reduced BMD and fracture are more common in persons with IBD, the precise burden is not well characterized. Also, the relative impact of IBD-associated factors and IBD-specific inflammation on bone health is still uncertain.
    Current opinion in gastroenterology 01/2014; · 4.33 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background and aims Few studies have specifically examined models of care in IBD. This survey was designed to help gather information from health professionals working in IBD services on current care models, and their views on how to best reshape existing models for IBD care worldwide. Methods An online mixed-methods survey was conducted with health professionals caring for IBD patients. Recruitment was conducted using the snowballing technique, where members of professional networks of the investigators were invited to participate. Results of the survey were summarised using descriptive statistics. Results Of the 135 included respondents, 76 (56%) were female, with a median age of 44 (range: 23–69) years, 50% were GI physicians, 34% nurses, 8% psychologists, 4% dieticians, 2% surgeons, 1% psychiatrists, and 1% physiotherapists. Overall, 73 (54%) respondents considered their IBD service to apply the integrated model of care, and only 5% reported that they worked exclusively using the biomedical care (no recognition of psychosocial factors). The majority of respondents reported including mental health assessment in their standard IBD care (65%), 51% believed that an ideal IBD service should be managed in specialist led clinics, and 64% wanted the service to be publicly funded. Respondents pictured an ideal IBD service as easy-access fully multi-disciplinary, with a significant role for IBD nurses and routine psychological and nutritional assessment and care. Conclusions Health care professionals believe that an ideal IBD service should: be fully integrated, involve significant roles of nurses, psychologists and dieticians, run in specialist clinics, be easily accessible to patients and publicly funded.
    Journal of Crohn's and Colitis. 01/2014;
  • Charles N. Bernstein
    Clinical Gastroenterology and Hepatology. 01/2014; 12(5):828–830.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background & Aims Little is known about how often, and for what reasons, patients with inflammatory bowel diseases (IBD) are admitted to the intensive care unit (ICU). We compared incidences of ICU admission, characteristics of critical illness, and mortality after ICU admission between patients with IBD and the general population. Methods We identified all persons with IBD in the province of Manitoba using a validated administrative definition of IBD for the period 1984 to 2010. Cases were considered incident for IBD if their first health system contact for IBD was in 1989 or later. We identified a population-based control group, matched by age, sex, and geography (based on postal code). Case and control cohorts were linked to the Manitoba ICU database. We compared outcomes between groups using age- and sex-standardized rates, Cox proportional hazards models, and logistic regression models, adjusting for age, sex, comorbidity, and socioeconomic status. Results There were 8224 prevalent and 4580 incident cases of IBD. After adjustment, the risk for ICU admission was higher for patients with IBD than controls (hazard ratio [HR], 1.79; 1.58–2.02). The risk of ICU admission was higher for patients with Crohn’s disease (HR, 2.31; 1.95–2.75) than ulcerative colitis (HR, 1.37; 1.13–1.65). From 2000 through 2010, age- and sex-standardized annual incidence rates for ICU admission in the prevalent IBD cohort ranged from 0.55% to 1.12%. Compared to controls admitted to ICUs, 1 year after ICU admission, mortality was 32% among patients with IBD. Conclusions Patients with IBD have a higher risk for admission to the ICU than the general population, and increased mortality 1 year after admission. These findings underscore the potential severity of IBD.
    Clinical Gastroenterology and Hepatology. 01/2014;
  • [Show abstract] [Hide abstract]
    ABSTRACT: Disability is defined by chronic limitations that preclude the ability to engage in usual daily activities. Studies of disability in patients with IBD have focused on work and employment, with few descriptions of more general disability among multiple domains. We examined disability and the factors associated with it a decade after diagnosis in a population-based cohort of IBD patients. We interviewed 125 patients with Crohn's disease (CD) and 119 with ulcerative colitis (UC) from the population-based Manitoba IBD Cohort study a median of 12.3 y after diagnosis. Disability was assessed using 2 validated measures. Disease activity was assessed semi-annually, and long-term activity was defined as symptoms of active IBD at more than 65% of semi-annual assessments. Mean levels of disability were significantly higher among patients with CD than those with UC (P<.01). Based on the Work and Social Adjustment Scale (WSAS), rates of disability were 19% among patients with CD vs 11% among those with UC (P<.05). Results from the World Health Organization Disability Assessment Schedule 2 and the WSAS correlated (r=0.58 for patients with CD and 0.60 for those with UC; P<.01). Disability was associated with reduced quality of life. Long-term active disease and a lifetime history of major depression were associated with disability, whereas history of IBD-related surgeries or hospitalizations were not. A minority of patients with IBD have significant disability after a decade of disease, although a higher proportion of patients with CD are disabled than those with UC. Long-term active disease and psychologic factors are important predictors of disability. Depression should be treated as aggressively as the IBD itself.
    Clinical gastroenterology and hepatology: the official clinical practice journal of the American Gastroenterological Association 12/2013; · 5.64 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Crohn disease (CD) and ulcerative colitis (UC) are 2 common inflammatory bowel diseases (IBDs) associated with intestinal inflammation and tissue damage. Oxidative stress is suggested to play a major role in the initiation and progression of IBD. Vitamin C (ascorbate, ascorbic acid) supplementation has reduced oxidative stress in persons with IBD. The role of ascorbate transporters in IBD remains to be determined. SLC23A1 is a major ascorbate transporter in the intestinal tract, and some of its genetic variants have been associated with severely decreased ascorbate transport and lower systemic concentrations. This study aimed to determine whether common genetic variants in the vitamin C transporter SLC23A1 are associated with the risk of IBD. Genomic DNA samples from patients with CD (n = 162) and UC (n = 149) from the Manitoba IBD Cohort Study and ethnically matched controls (n = 142) were genotyped for 3 SLC23A1 polymorphisms (rs6596473, rs33972313, and rs10063949) by using TaqMan assays. Variation at rs10063949 (G allele for heterozygote and homozygote) was associated with increased susceptibility to CD (OR: 2.54; 95% CI: 1.38, 4.66; OR: 4.72; 95% CI: 2.53, 8.81; P < 0.0001; respectively). A strong linkage disequilibrium (LD) was observed across the SLC23A1region (variation rs6596473 with rs10063949) for CD and UC (D' = 0.94 and 0.96, respectively). The risk alleles confirmed a haplotype (CGG) that is carried more in CD patients (65.3%, P < 0.0001) than in controls (43.5%). A genetic variant (rs10063949-G) in the SLC23A1 ascorbate transporter locus was identified, which is associated with an increased risk of CD in a white Canadian IBD cohort. The presented evidence that SLC23A1 variations can modulate the risk of CD has implications for understanding ascorbate transport in CD patients and provides a novel opportunity toward individualized nutritional therapy for patients carrying the disease-associated genotype.
    American Journal of Clinical Nutrition 11/2013; · 6.50 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: : This review describes the history of U.S. government funding for surveillance programs in inflammatory bowel diseases (IBD), provides current estimates of the incidence and prevalence of IBD in the United States, and enumerates a number of challenges faced by current and future IBD surveillance programs. A rationale for expanding the focus of IBD surveillance beyond counts of incidence and prevalence, to provide a greater understanding of the burden of IBD, disease etiology, and pathogenesis, is provided. Lessons learned from other countries are summarized, in addition to potential resources that may be used to optimize a new form of IBD surveillance in the United States. A consensus recommendation on the goals and available resources for a new model for disease surveillance are provided. This new model should focus on "surveillance of the burden of disease," including (1) natural history of disease and (2) outcomes and complications of the disease and/or treatments.
    Inflammatory Bowel Diseases 11/2013; · 5.12 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Methotrexate and infliximab are effective therapies for Crohn's disease (CD). In the combination of maintenance methotrexate-infliximab trial, we evaluated the potential superiority of combination therapy over infliximab alone. In a 50-week double-blind, placebo-controlled trial, we compared methotrexate and infliximab to infliximab alone in 126 patients with CD who had initiated prednisone induction therapy (15 to 40 mg/day) within the preceding 6 weeks. Patients were randomly assigned to groups given methotrexate at an initial weekly dose of 10 mg, escalating to 25 mg/week (n=63), or placebo (n=63) . Both groups received infliximab (5 mg/kg of body weight) at weeks 1, 3, 7, 14 and every 8 weeks thereafter. Prednisone was tapered, beginning at week 1, and discontinued no later than week 14. The primary outcome was time to treatment failure, defined as lack of prednisone-free remission (CD Activity Index <150) at week 14 or failure to maintain remission through week 50. Patients' baseline characteristics were similar between groups. By week 50, the actuarial rate of treatment failure was 30.6% in the combination therapy group compared with 29.8% in the infliximab monotherapy group (P = .63; hazard ratio, 1.16; 95% confidence interval, 0.62-2.17). Pre-specified subgroup analyses failed to show a benefit in patients with short disease duration or an increased level of C-reactive protein. No clinically meaningful differences were observed in secondary outcomes. Combination therapy was well tolerated. The combination of infliximab and methotrexate, although safe, was no more effective than infliximab alone in patients with CD receiving treatment with prednisone. NCT00132899.
    Gastroenterology 11/2013; · 12.82 Impact Factor
  • Source
  • Charles N Bernstein
    Clinical gastroenterology and hepatology: the official clinical practice journal of the American Gastroenterological Association 11/2013; · 5.64 Impact Factor
  • Charles N Bernstein, Laura E Targownik, William D Leslie
    Gut 11/2013; · 10.73 Impact Factor
  • Dana C Moffatt, B Nancy Yu, Wiechun Yie, Charles N Bernstein
    [Show abstract] [Hide abstract]
    ABSTRACT: Comprehensive, population-based data on ERCP use over the last 30 years in North America are lacking. To establish crude and age-adjusted population-based rates of ERCP, evaluate for changing indications for ERCP, and evaluate for interactions between cholecystectomy technique and ERCP use from 1984 to 2009. Retrospective, comprehensive, population-based study. All inpatient and outpatient ERCPs and cholecystectomies in Manitoba, Canada from 1984 to 2009. All residents of Manitoba, Canada with a history of ERCP and/or cholecystectomy. None. Yearly crude and age-adjusted rates of ERCP (diagnostic and therapeutic) and cholecystectomy (open, laparoscopic, and with open bile duct exploration), and patient and/or procedure demographics. The rate of ERCP/10,000 people increased from 7.70 (1984) to 13.86/10,000 (2009) (P = .001). Diagnostic ERCP declined from 7.28/10,000 (1984) to 1.11/10,000 (2009), and therapeutic ERCP increased from 0.42/10,000 (1984) to 12.75/10,000 (2009) (P < .001). ERCPs were more common in women (62%) and in older populations (60-79 years, >80 years), with rates of therapeutic ERCP reaching 62.58/10,000 in the elderly. The primary indication for ERCP has changed over time, with biliary indications increasing from 50.3% to 67.3% and pancreatic indications decreasing from 18.3% to 8.1% (P < .05). The rate of therapeutic ERCP increased during the transition from open to laparoscopic cholecystectomy (1991-1994), whereas open bile duct exploration (OBDE) decreased from 2.0 to 0.18/10,000 (P < .001). Retrospective analysis, administrative data. ERCP use increased steadily from 1984 to 2009, and changed from a diagnostic modality to a therapeutic one. Changes in cholecystectomy technique may have influenced therapeutic ERCP use and likewise, the availability of therapeutic ERCP has decreased the need for OBDE.
    Gastrointestinal endoscopy 10/2013; · 6.71 Impact Factor

Publication Stats

13k Citations
2,743.89 Total Impact Points

Institutions

  • 1994–2014
    • University of Manitoba
      • • Department of Internal Medicine
      • • Department of Clinical Health Psychology
      • • Department of Surgery
      Winnipeg, Manitoba, Canada
  • 2013
    • Hebrew University of Jerusalem
      Yerushalayim, Jerusalem District, Israel
  • 2007–2013
    • Johns Hopkins University
      • Department of Medicine
      Baltimore, MD, United States
  • 2012
    • Centre Hospitalier Universitaire de Grenoble
      Grenoble, Rhône-Alpes, France
  • 2011–2012
    • University of Toronto
      Toronto, Ontario, Canada
    • University of Saskatchewan
      • School of Public Health
      Saskatoon, Saskatchewan, Canada
    • Hôpital St-Boniface Hospital
      Winnipeg, Manitoba, Canada
    • University of Newcastle
      • Faculty of Health and Medicine
      Newcastle, New South Wales, Australia
    • Mount Sinai Hospital, Toronto
      • Zane Cohen Centre for Digestive Diseases
      Toronto, Ontario, Canada
  • 2004–2012
    • University College Cork
      • • School of Medicine
      • • Alimentary Pharmabiotic Centre
      Cork, M, Ireland
  • 2007–2011
    • Health Sciences Centre Winnipeg
      Winnipeg, Manitoba, Canada
  • 2003–2011
    • The University of Winnipeg
      Winnipeg, Manitoba, Canada
  • 2006
    • Government of Manitoba, Canada
      Winnipeg, Manitoba, Canada
  • 2001–2002
    • National Research Council Canada
      • Institute for Biodiagnostics (IBD)
      Ottawa, Ontario, Canada
  • 1993–1995
    • University of California, Los Angeles
      • Department of Medicine
      Los Angeles, CA, United States
  • 1991–1992
    • Harbor-UCLA Medical Center
      Torrance, California, United States