Halifax, Canada
Halifax, Canada

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Hystad P.,University of British Columbia | Setton E.,University of Victoria | Cervantes A.,University of British Columbia | Poplawski K.,University of British Columbia | And 9 more authors.
Environmental Health Perspectives | Year: 2011

Background: Population exposure assessment methods that capture local-scale pollutant variability are needed for large-scale epidemiological studies and surveillance, policy, and regulatory purposes. Currently, such exposure methods are limited. Methods: We created 2006 national pollutant models for fine particulate matter [PM with aerodynamic diameter ≤ 2.5 μm (PM 2.5)], nitrogen dioxide (NO 2), benzene, ethylbenzene, and 1,3-butadiene from routinely collected fixed-site monitoring data in Canada. In multiple regression models, we incorporated satellite estimates and geographic predictor variables to capture background and regional pollutant variation and used deterministic gradients to capture local-scale variation. The national NO 2 and benzene models are evaluated with independent measurements from previous land use regression models that were conducted in seven Canadian cities. National models are applied to census block-face points, each of which represents the location of approximately 89 individuals, to produce estimates of population exposure. Results: The national NO 2 model explained 73% of the variability in fixed-site monitor concentrations, PM 2.5 46%, benzene 62%, ethylbenzene 67%, and 1,3-butadiene 68%. The NO 2 model predicted, on average, 43% of the within-city variability in the independent NO 2 data compared with 18% when using inverse distance weighting of fixed-site monitoring data. Benzene models performed poorly in predicting within-city benzene variability. Based on our national models, we estimated Canadian ambient annual average population-weighted exposures (in micrograms per cubic meter) of 8.39 for PM 2.5, 23.37 for NO 2, 1.04 for benzene, 0.63 for ethylbenzene, and 0.09 for 1,3-butadiene. Conclusions: The national pollutant models created here improve exposure assessment compared with traditional monitor-based approaches by capturing both regional and local-scale pollution variation. Applying national models to routinely collected population location data can extend land use modeling techniques to population exposure assessment and to informing surveillance, policy, and regulation.


Reid J.M.,Royal Infirmary | Dai D.,Children's Hospital of Philadelphia | Cheripelli B.,University of Glasgow | Christian C.,DalhousieUniversity | And 3 more authors.
International Journal of Stroke | Year: 2015

Debate exists as to whether wake-up stroke (WUS) (i.e. symptoms first noted on waking) differs from stroke developing while awake [awake onset stroke (AOS)]. Unknown onset stroke (UOS) with unclear symptom onset time is infrequently studied. Aims: This study aimed to examine differences in stroke characteristics and outcomes in these three groups. Methods: The stroke registry database from Halifax Infirmary, Canada, was interrogated for hospitalised stroke patients between 1999-2011. Information was available on demographics, stroke characteristics, and functional status at discharge and six months (modified Rankin score [mRS]). Results: Of 3890 patients, 65% had AOS, 21% WUS and 14% UOS. UOS patients were significantly older, more commonly female and living alone than AOS patients, with no difference between AOS and WUS. UOS rates increased from 10 to 16% of patients during the study period (P<0·0001). UOS but not WUS had a higher stroke severity than AOS. Intracerebral hemorrhage was less common (9 vs. 13%) and lacunar stroke more common (23 vs. 19%) in WUS compared to AOS. In UOS left hemisphere location was more likely, and lacunar stroke less common. Excellent outcomes were slightly lower for WUS. UOS had significantly higher rates of in-hospital mortality (23 vs. 16%, P<0·0001) and poorer functional outcome six months after stroke (mRS<3 in 26% of UOS and 46% of AOS, P=0·02). Conclusion: WUS has lower rates of ICH but similar stroke severity and outcomes to AOS. UOS prevalence appears to be increasing, with higher stroke severity and worse prognosis. © 2014 World Stroke Organization.


Bandiera G.,University of Toronto | LeBlanc C.,DalhousieUniversity | Regehr G.,University of British Columbia | Snell L.,McGill University | And 2 more authors.
Canadian Journal of Emergency Medicine | Year: 2014

Emergency medicine (EM) is defined, in part, by clinical excellence across an immense breadth of content and the provision of exemplary bedside teaching to a wide variety of learners. The specialty is also well-suited to a number of emerging areas of education scholarship, particularly in relation to team-based learning, clinical reasoning, acute care response, and simulation-based teaching. The success of EM education scholarship will be predicated on systematic, collective attention to providing the infrastructure for this to occur. Specifically, as a new generation of emergency physicians prepares for education careers, academic organizations need to develop means not only to identify potential scholars but also to mentor, support, and encourage their careers. This paper summarizes the supporting literature and presents related recommendations from a 2013 consensus conference on EM education scholarship led by the Academic Section of the Canadian Association of Emergency Physicians.


Radic J.A.E.,Brigham And Womens Hospital | Radic J.A.E.,DalhousieUniversity | Chou S.H.-Y.,Brigham And Womens Hospital | Du R.,Brigham And Womens Hospital | Lee J.W.,Brigham And Womens Hospital
Neurocritical Care | Year: 2014

Background: Although both levetiracetam and phenytoin are used for seizure prophylaxis in subdural hematomas (SDHs), there is little data on their comparative efficacies. We compared the efficacy and risk of using levetiracetam versus phenytoin for seizure prophylaxis following acute or subacute SDH diagnosis.Methods: In this retrospective cohort study, the clinical data registry at a tertiary care hospital was searched for all cases of acute or subacute SDHs that were admitted to hospital in 2002, 2003, or 2011. Risk of clinical and/or electrographic seizures, and risk of adverse drug events were compared between the two exposure arms.Results: 124 subjects in the phenytoin arm and 164 subjects in the levetiracetam arm were included. There was no significant difference in clinical and/or electrographic seizure risk, though there was a decreased risk of adverse events in the levetiracetam arm (p < 0.001). In subjects with midline shift >0 mm, levetiracetam was associated with an increased risk of electrographic seizures during hospitalization (p = 0.028) and a decreased risk of adverse drug effects (p = 0.001), compared with phenytoin use.Conclusions: Levetiracetam generally appears to have a similar efficacy to phenytoin in preventing clinical and/or electrographic seizures following acute/subacute SDH diagnosis, though patients with midline shift >0 mm may have associated with a higher risk of electrographic seizures on levetiracetam compared with patients on phenytoin. Levetiracetam is associated with a lower risk of adverse drug effects. A prospective, randomized study would more definitively determine any difference in efficacy and risk between phenytoin and levetiracetam. © 2014, Springer Science+Business Media New York.


Jurgens T.M.,DalhousieUniversity
Cochrane database of systematic reviews (Online) | Year: 2012

Preparations of green tea are used as aids in weight loss and weight maintenance. Catechins and caffeine, both contained in green tea, are each believed to have a role in increasing energy metabolism, which may lead to weight loss. A number of randomised controlled trials (RCTs) evaluating the role of green tea in weight loss have been published; however, the efficacy of green tea preparations in weight loss remains unclear. To assess the efficacy and safety of green tea preparations for weight loss and weight maintenance in overweight or obese adults. We searched the following databases from inception to specified date as well as reference lists of relevant articles: The Cochrane Library (Issue 12, 2011), MEDLINE (December 2011), EMBASE (December 2011), CINAHL (January 2012), AMED (January 2012), Biological Abstracts (January 2012), IBIDS (August 2010), Obesity+ (January 2012), IPA (January 2012) and Web of Science (December 2011). Current Controlled Trials with links to other databases of ongoing trials was also searched. RCTs of at least 12 weeks' duration comparing green tea preparations to a control in overweight or obese adults. Three authors independently extracted data, assessed studies for risk of bias and quality, with differences resolved by consensus. Heterogeneity of included studies was assessed visually using forest plots and quantified using the I(2) statistic. We synthesised data using meta-analysis and descriptive analysis as appropriate; subgroup and sensitivity analyses were conducted. Adverse effects reported in studies were recorded. Due to the level of heterogeneity among studies, studies were divided into two groups; those conducted in Japan and those conducted outside Japan. Study length ranged between 12 and 13 weeks. Meta-analysis of six studies conducted outside Japan showed a mean difference (MD) in weight loss of -0.04 kg (95% CI -0.5 to 0.4; P = 0.88; I(2) = 18%; 532 participants). The eight studies conducted in Japan were not similar enough to allow pooling of results and MD in weight loss ranged from -0.2 kg to -3.5 kg (1030 participants) in favour of green tea preparations. Meta-analysis of studies measuring change in body mass index (BMI) conducted outside Japan showed a MD in BMI of -0.2 kg/m(2) (95% CI -0.5 to 0.1; P = 0.21; I(2) = 38%; 222 participants). Differences among the eight studies conducted in Japan did not allow pooling of results and showed a reduction in BMI ranging from no effect to -1.3 kg/m(2) (1030 participants), in favour of green tea preparations over control. Meta-analysis of five studies conducted outside Japan and measuring waist circumference reported a MD of -0.2 cm (95% CI -1.4 to 0.9; P = 0.70; I(2) = 58%; 404 participants). Differences among the eight studies conducted in Japan did not allow pooling of results and showed effects on waist circumference ranging from a gain of 1 cm to a loss of 3.3 cm (1030 participants). Meta-analysis for three weight loss studies, conducted outside Japan, with waist-to-hip ratio data (144 participants) yielded no significant change (MD 0; 95% CI -0.02 to 0.01). Analysis of two studies conducted to determine if green tea could help to maintain weight after a period of weight loss (184 participants) showed a change in weight loss of 0.6 to -1.6 kg, a change in BMI from 0.2 to -0.5 kg/m(2) and a change in waist circumference from 0.3 to -1.7 cm. In the eight studies that recorded adverse events, four reported adverse events that were mild to moderate, with the exception of two (green tea preparations group) that required hospitalisation (reported as not associated with the intervention). Nine studies reported on compliance/adherence, one study assessed attitude towards eating as part of the health-related quality of life outcome. No studies reported on patient satisfaction, morbidity or cost. Green tea preparations appear to induce a small, statistically non-significant weight loss in overweight or obese adults. Because the amount of weight loss is small, it is not likely to be clinically important. Green tea had no significant effect on the maintenance of weight loss. Of those studies recording information on adverse events, only two identified an adverse event requiring hospitalisation. The remaining adverse events were judged to be mild to moderate.


Benstead T.J.,DalhousieUniversity | Chalk C.H.,DalhousieUniversity | Parks N.E.,DalhousieUniversity
The Cochrane database of systematic reviews | Year: 2014

BACKGROUND: Peripheral neuropathy is the most common neurologic complication of hepatitis C virus (HCV) infection. The pathophysiology of the neuropathy associated with HCV is not definitively known; however, proposed mechanisms include cryoglobulin deposition in the vasa nervorum and HCV-mediated vasculitis. The optimal treatment for HCV-related peripheral neuropathy has not been established.OBJECTIVES: To assess the effects of interventions (including interferon alfa, interferon alfa plus ribavirin, corticosteroids, cyclophosphamide, plasma exchange, and rituximab) for cryoglobulinemic or non-cryoglobulinemic peripheral neuropathy associated with HCV infection.SEARCH METHODS: On 26 August 2014, we searched the Cochrane Neuromuscular Disease Group Specialized Register, CENTRAL, MEDLINE, and EMBASE. We also searched two trials registers, the Networked Digital Library of Theses and Dissertations (NDLTD) (October 2014), and three other databases. We checked references in identified trials and requested information from trial authors to identify any additional published or unpublished data.SELECTION CRITERIA: We included all randomized controlled trials (RCTs) and quasi-RCTs involving participants with cryoglobulinemic or non-cryoglobulinemic peripheral neuropathy associated with HCV infection. We considered any intervention (including interferon alfa, interferon alfa plus ribavirin, corticosteroids, cyclophosphamide, plasma exchange, and rituximab) alone or in combination versus placebo or another intervention ('head-to-head' comparison study design) evaluated after a minimum interval to follow-up of at least six months.DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by The Cochrane Collaboration. The planned primary outcome was change in sensory impairment (using any validated sensory neuropathy scale or quantitative sensory testing) at the end of the follow-up period.  Other planned outcomes were: change in impairment (any validated combined sensory and motor neuropathy scale), change in disability (any validated disability scale), electrodiagnostic measures, number of participants with improved symptoms of neuropathy (global impression of change), and severe adverse events.MAIN RESULTS: Four trials of HCV-related cryoglobulinemia fulfiled selection criteria and the review authors included three in quantitative synthesis. All studies were at high risk of bias. No trial addressed the primary outcome of change in sensory impairment. No trial addressed secondary outcomes of change in combined sensory and motor impairment, disability, or electrodiagnostic measures. A single trial of HCV-related mixed cryoglobulinemia treated with pegylated interferon alfa (peginterferon alfa), ribavirin, and rituximab versus peginterferon alfa and ribavirin did not show a significant difference in the number of participants with improvement in neuropathy at 36 months post treatment (risk ratio (RR) 4.00, 95% confidence interval (CI) 0.27 to 59.31, n = 9). One study of interferon alfa (n = 22) and two studies of rituximab (n = 61) provided adverse event data. Severe adverse events were no more common with interferon alfa (RR 7.00, 95% CI 0.38 to 128.02) or rituximab (RR 3.00, 95% CI 0.13 to 67.06) compared to the control group.AUTHORS' CONCLUSIONS: There is a lack of RCTs and quasi-RCTs addressing the effects of interventions for peripheral neuropathy associated with HCV infection. At present, there is insufficient evidence from RCTs and quasi-RCTs to make evidence-based decisions about treatment.


PubMed | DalhousieUniversity
Type: Journal Article | Journal: The Journal of biological chemistry | Year: 2011

Vesicular transport shuttles cargo among intracellular compartments. Several stages of vesicular transport are mediated by the small GTPase Arf, which is controlled in a cycle of GTP binding and hydrolysis by Arf guanine-nucleotide exchange factors and Arf GTPase-activating proteins (ArfGAPs), respectively. In budding yeast the Age2 + Gcs1 ArfGAP pair facilitates post-Golgi transport. We have found the AGE1 gene, encoding another ArfGAP, can in high gene-copy number alleviate the temperature sensitivity of cells carrying mutations affecting the Age2 + Gcs1 ArfGAP pair. Moreover, increased AGE1 gene dosage compensates for the complete absence of the otherwise essential Age2 + Gcs1 ArfGAP pair. Increased dosage of SFH2, encoding a phosphatidylinositol transfer protein, also allows cell growth in the absence of the Age2 + Gcs1 pair, but good growth in this situation requires Age1. The ability of Age1 to overcome the need for Age2 + Gcs1 depends on phospholipase D activity that regulates lipid composition. We show by direct assessment of Age1 ArfGAP activity that Age1 is regulated by lipid composition and can provide ArfGAP function for post-Golgi transport.


PubMed | DalhousieUniversity
Type: | Journal: The Cochrane database of systematic reviews | Year: 2012

Preparations of green tea are used as aids in weight loss and weight maintenance. Catechins and caffeine, both contained in green tea, are each believed to have a role in increasing energy metabolism, which may lead to weight loss. A number of randomised controlled trials (RCTs) evaluating the role of green tea in weight loss have been published; however, the efficacy of green tea preparations in weight loss remains unclear.To assess the efficacy and safety of green tea preparations for weight loss and weight maintenance in overweight or obese adults.We searched the following databases from inception to specified date as well as reference lists of relevant articles: The Cochrane Library (Issue 12, 2011), MEDLINE (December 2011), EMBASE (December 2011), CINAHL (January 2012), AMED (January 2012), Biological Abstracts (January 2012), IBIDS (August 2010), Obesity+ (January 2012), IPA (January 2012) and Web of Science (December 2011). Current Controlled Trials with links to other databases of ongoing trials was also searched.RCTs of at least 12 weeks duration comparing green tea preparations to a control in overweight or obese adults.Three authors independently extracted data, assessed studies for risk of bias and quality, with differences resolved by consensus. Heterogeneity of included studies was assessed visually using forest plots and quantified using the I(2) statistic. We synthesised data using meta-analysis and descriptive analysis as appropriate; subgroup and sensitivity analyses were conducted. Adverse effects reported in studies were recorded.Due to the level of heterogeneity among studies, studies were divided into two groups; those conducted in Japan and those conducted outside Japan. Study length ranged between 12 and 13 weeks. Meta-analysis of six studies conducted outside Japan showed a mean difference (MD) in weight loss of -0.04 kg (95% CI -0.5 to 0.4; P = 0.88; I(2) = 18%; 532 participants). The eight studies conducted in Japan were not similar enough to allow pooling of results and MD in weight loss ranged from -0.2 kg to -3.5 kg (1030 participants) in favour of green tea preparations. Meta-analysis of studies measuring change in body mass index (BMI) conducted outside Japan showed a MD in BMI of -0.2 kg/m(2) (95% CI -0.5 to 0.1; P = 0.21; I(2) = 38%; 222 participants). Differences among the eight studies conducted in Japan did not allow pooling of results and showed a reduction in BMI ranging from no effect to -1.3 kg/m(2) (1030 participants), in favour of green tea preparations over control. Meta-analysis of five studies conducted outside Japan and measuring waist circumference reported a MD of -0.2 cm (95% CI -1.4 to 0.9; P = 0.70; I(2) = 58%; 404 participants). Differences among the eight studies conducted in Japan did not allow pooling of results and showed effects on waist circumference ranging from a gain of 1 cm to a loss of 3.3 cm (1030 participants). Meta-analysis for three weight loss studies, conducted outside Japan, with waist-to-hip ratio data (144 participants) yielded no significant change (MD 0; 95% CI -0.02 to 0.01). Analysis of two studies conducted to determine if green tea could help to maintain weight after a period of weight loss (184 participants) showed a change in weight loss of 0.6 to -1.6 kg, a change in BMI from 0.2 to -0.5 kg/m(2) and a change in waist circumference from 0.3 to -1.7 cm. In the eight studies that recorded adverse events, four reported adverse events that were mild to moderate, with the exception of two (green tea preparations group) that required hospitalisation (reported as not associated with the intervention). Nine studies reported on compliance/adherence, one study assessed attitude towards eating as part of the health-related quality of life outcome. No studies reported on patient satisfaction, morbidity or cost.Green tea preparations appear to induce a small, statistically non-significant weight loss in overweight or obese adults. Because the amount of weight loss is small, it is not likely to be clinically important. Green tea had no significant effect on the maintenance of weight loss. Of those studies recording information on adverse events, only two identified an adverse event requiring hospitalisation. The remaining adverse events were judged to be mild to moderate.


PubMed | DalhousieUniversity
Type: | Journal: Journal (Canadian Dental Association) | Year: 2010

Although laser treatment has generated considerable interest among dentists and the public, there is no evidence that any laser system adds clinical value over and above scaling and root planing and conventional surgical treatment for periodontitis. Following a brief explanation of the mechanism behind soft tissue lasers, the evidence on the use of laser therapy in addition to traditional nonsurgical periodontal treatment in the management of periodontal diseases is reviewed.

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