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Higher concentrations of vitamin D in Canadian children with juvenile idiopathic arthritis compared to healthy controls are associated with more frequent use of vitamin D supplements and season of birth
No full textA number of studies have demonstrated that patients with autoimmune disease have lower levels of vitamin D prompting speculation that vitamin D might suppress inflammation and immune responses in children with juvenile idiopathic arthritis (JIA). The objective of this study was to compare vitamin D levels in children with JIA at disease onset with healthy children. We hypothesized that children and adolescents with JIA have lower vitamin D levels than healthy children and adolescents. Data from a Canadian cohort of children with new-onset JIA (n= 164, data collection 2007-2012) were compared to Canadian Health Measures Survey (CHMS) data (n=4027, data collection 2007-2011). We compared 25-hydroxy vitamin D (25(OH)D) concentrations with measures of inflammation, vitamin D supplement use, milk intake, and season of birth. Mean 25(OH)D level was significantly higher in patients with JIA (79 ± 3.1 nmol/L) than in healthy controls (68 ± 1.8 nmol/L P <.05). Patients with JIA more often used vitamin D containing supplements (50% vs. 7%; P <.05). The prevalence of 25(OH)D deficiency (<30 nmol/L) was 6% for both groups. Children with JIA with 25(OH)D deficiency or insufficiency (<50 nmol/L) had higher C-reactive protein levels. Children with JIA were more often born in the fall and winter compared to healthy children. In contrast to earlier studies, we found vitamin D levels in Canadian children with JIA were higher compared to healthy children and associated with more frequent use of vitamin D supplements. Among children with JIA, low vitamin D levels were associated with indicators of greater inflammation
Characterization of the microbiota and resistome of bulk tank milk samples from Prince Edward Island dairy farms
No full textBulk tank milk (BTM) is regularly used for surveillance on dairy farms for disease conditions such as mastitis and Johne's disease. In this study, we used 16S rRNA sequencing and bait-capture enrichment to characterize the microbiota and resistome of BTM, and investigate potential differences between the cream or pellet fractions. A total of 12 BTM samples were taken from 12 Prince Edward Island dairy farms, in Atlantic Canada, in duplicates. The DNA was analyzed by high-throughput sequencing of the 16S rRNA gene and a suite of antimicrobial resistance (AMR) genes. Target-capture enrichment of AMR genes was conducted before shotgun sequencing. The bioinformatics pipelines QIIME 2 and AMR++ were used for microbiota and resistome analysis, respectively. Differences between microbiotae were evaluated qualitatively with nonmetric multidimensional scaling and quantitatively with permutational ANOVA of UniFrac distances. A total of 47 phyla were present across the BTM samples. Firmicutes, Bacteroidetes, Proteobacteria, and Actinobacteria were the most abundant phyla. At the genus level, Corynebacterium, Acinetobacter, Lactobacillus, and Turicibacter were the most abundant. There was no significant difference in the Faith's phylogenetic diversity between the cream and pellet fraction. Faith's phylogenetic diversity differed marginally by stall type. There were 10,217 hits across 80 unique AMR genes, with tetracycline resistance being the most common class
A note on the structure of matrix ^*-subalgebras with scalar diagonals
No full textWe characterize those unital, self-adjoint algebras of complex n×n matrices that are
simultaneously unitarily similar to algebras in which every member has a scalar diagonal.Natural Sciences and Engineering Research Council of CanadaSlovenian Research Agenc
Anoxia-reoxygenation alters H2O2 efflux and sensitivity of redox centers to copper in heart mitochondria
No full textMitochondrial reactive oxygen species (ROS) have been implicated in organ damage caused by environmental stressors, prompting studies on the effect of oxygen deprivation and metal exposure on ROS metabolism. However, how anoxia and copper (Cu) jointly influence heart mitochondrial ROS metabolism is not understood. We used rainbow trout heart mitochondria to probe the effects of anoxia-reoxygenation and Cu on hydrogen peroxide (H2O2) emission during oxidation of palmitoylcarnitine (PC), succinate, or glutamate-malate. In addition, we examined the influence of anoxia-reoxygenation and Cu on site-specific H2O2 emission capacities and key antioxidant enzymes, glutathione peroxidase (GPx) and thioredoxin reductase (TrxR). Results showed that anoxia-reoxygenation suppressed H2O2 emission regardless of substrate type or duration of anoxia. Anoxia-reoxygenation reduced mitochondrial sensitivity to Cu during oxidation of succinate or glutamate-malate whereas high Cu concentration additively stimulated H2O2 emission in mitochondria oxidizing PC. Prolonged anoxia-reoxygenation stimulated H2O2 emission from sites OF and IF, inhibited emission from sites IQ, IIF and IIIQo, and disparately altered the sensitivity of the sites to Cu. Interestingly, anoxia-reoxygenation increased GPx and TrxR activities, more prominently when reoxygenation followed a short duration of anoxia. Cu did not alter GPx but reduced TrxR activity in normoxic and anoxic-reoxygenated mitochondria. Overall, our study revealed potential mechanisms that may reduce oxidative damage associated with anoxia-reoxygenation and Cu exposure in heart mitochondria. The increased and decreased H2O2 emission from NADH/NAD+ and QH2/Q isopotential sites, respectively, may represent a balance between H2O2 required for oxygen deprivation-induced signaling and prevention of ROS burst associated with anoxia-reoxygenation
Antimicrobial peptides as an alternative to relieve antimicrobial growth promoters in poultry
No full text1. This review describes different classes of antimicrobial peptides (AMP) found in the gastrointestinal (GI) tract of avian species, and their antimicrobial and immunomodulatory activities. The potential benefits of synthetic AMP in poultry production are examined, in the context of the use of AMP as alternatives to antimicrobial growth promoters (AGP). 2. Since the mid-1950s, antibiotic growth promoters (AGP) have been used in feed at low prophylactic doses to modulate the homoeostasis of intestinal microbiota, decreasing the risk of intestinal dysbacteriosis and the growth of pathogens within the avian gut. Over the last three decades, AGP have faced major regulatory restrictions due to concerns of generating antimicrobial resistance (AMR). It is now well documented that the rate of infectious disease outbreaks is higher in flocks that are not fed prophylactic antibiotics, resulting in a compensatory increase in antimicrobial use for therapeutic purposes. 3. Endogenous natural AMP production is associated with the presence of microbiota and their interaction with the intestinal epithelial and lamina propria lymphoid cells. Their antimicrobial activity shapes the beneficial microbiota population and controls intestinal pathogens such Clostridium and Salmonella spp., and stimulates the development and maturation of the local immune system. 4. Similar to AGP, AMP can establish a well-balanced gut beneficial microbiota for adequate immune-competence, animal health and high growth performance parameters such as feed intake, daily weight, feed conversion and accumulated mortality. 5. Antimicrobial proteins and peptides constitute an essential part of the innate immune system of all organisms and protect the host from invading pathogenic bacteria, viruses, fungi, and parasites by interacting with the negatively charged pathogen membranes.Canadian Poultry Research Counci
Morphological, physiological and behavioral responses of an intertidal snail, Acanthina monodon (Pallas), to projected ocean acidification and cooling water conditions in upwelling ecosystems
No full textOcean acidification (OA) is expected to rise towards the end of the 21st century altering the life history traits in marine organisms. Upwelling systems will not escape OA, but unlike other areas of the ocean, cooling effects are expected to intensify in these systems. Regardless, studies evaluating the combined effects of OA and cooling remain scarce. We addressed this gap using a mesocosm system, where we exposed juveniles of the intertidal muricid snail Acanthina monodon to current and projected pCO2 (500 vs. 1500 ppm) and temperature (15 vs. 10 °C) from the southeast Pacific upwelling system. After 9 weeks of experimental exposure to those conditions, we conducted three estimations of growth (wet weight, shell length and shell peristomal length), in addition to measuring calcification, metabolic and feeding rates and the ability of these organisms to return to the normal upright position after being overturned (self-righting). Growth, feeding and calcification rates increased in projected cooling conditions (10 °C) but were unaffected by pCO2 or the interaction between pCO2 and temperature. Instead, metabolic rates were driven by pCO2, but a significant interaction with temperature suggests that in cooler conditions, metabolic rates will increase when associated with high pCO2 levels. Snail self-righting times were not affected across treatments. These results suggest that colder temperatures projected for this area would drive this species growth, feeding and calcification, and consequently, some of its population biology and productivity. However, the snails may need to compensate for the increase in metabolic rates under the effects of ocean acidification. Although A. monodon ability to adjust to individual or combined stressors will likely account for some of the changes described here, our results point to a complex dynamic to take place in intertidal habitats associated with upwelling systems
Comparison of unmanned aerial vehicle technology versus standard practice of scene assessment by paramedic students of a mass-gathering event
No full textIntroduction: The proliferation of unmanned aerial vehicle (UAV) technology has the potential to change the situational awareness of medical incident commanders' (ICs') scene assessment of mass gatherings. Mass gatherings occur frequently and the potential for injury at these events is considered higher than the general population. These events have generated mass-casualty incidents (MCIs) in the past. The aim of this study was to compare UAV technology to standard practice (SP) in scene assessment using paramedic students during a mass-gathering event (MGE).
Methods: This study was conducted in two phases. Phase One consisted of validation of the videos and accompanying data collection tool. Phase One was completed by 11 experienced paramedics from a provincial Emergency Medical Services (EMS) service. Phase Two was a randomized comparison with 47 paramedic students from the Holland College Paramedicine Program (Charlottetown, Prince Edward Island, Canada) of the two scene assessment systems. For Phase Two, the paramedic students were randomized into a UAV or a SP group. The data collection tool consisted of two board categories: primary importance with 20 variables and secondary importance with 25 variables. After a brief narrative, participants were either shown UAV footage or the ground footage depending on their study group. After completion of the videos, study participants completed the data collection tool.
Results: The Phase One validation showed good consensus in answers to most questions (average 79%; range 55%-100%). For Phase Two, a Fisher's exact test was used to compare each variable from the UAV and SP groups using a P value of .05. Phase Two demonstrated a significant difference between the SP and UAV groups in four of 20 primary variables. Additionally, significant differences were found for seven out of 25 secondary variables.
Conclusion: This study demonstrated the accurate, safe, and feasible use of a UAV as a tool for scene assessment by paramedic students at an MGE. No observed statistical difference was noted in a majority of both primary and secondary variables using a UAV for scene assessment versus SP
Characteristics and outcomes of cats with and without pacemaker placement for high-grade atrioventricular block
No full textIntroduction: Available information on characteristics and outcome in cats with high-grade atrioventricular block (AVB) that receive a pacemaker is limited.
Animals: Twenty-two privately owned cats presenting with high-grade AVB.
Materials and methods: Medical records were retrospectively examined. Cats were grouped as having received a pacemaker (PACE group) or not having received a pacemaker (non-PACE group). Clinical characteristics and outcomes of groups were evaluated.
Results: There were 10 cats in the PACE group and 12 cats in the non-PACE group. At presentation, syncope or seizure-like behavior (p = 0.004) and bradycardia (p = 0.043) were more common in the PACE than the non-PACE group. Historical lethargy (p = 0.015) and dull mentation (p = 0.045) were more common in the non-PACE group, as was clinically relevant systemic disease. Pacemaker placement improved syncope or seizure-like behavior in 100% of cats. The degree of AVB at presentation was not associated with pacemaker placement nor the future degree of AVB. The major complication rate of pacemaker placement was 40%. Intergroup survival was not significantly different (PACE group 1278 days, 95% confidence interval: 0-2145 days; non-PACE group 213 days, confidence interval: 1-not available, p = 0.77).
Conclusions: Pacemaker placement improved clinical signs in cats with high-grade AVB. A difference in survival time could not be demonstrated between cats that received and did not receive a pacemaker in this retrospective study. High-grade AVB can be transient and accompanied by systemic disease in some cats
The Differential Effects of Salinity Level on Chlorpyrifos and Imidacloprid Toxicity to an Estuarine Amphipod
No full textAgricultural activity within coastal watersheds results in estuaries becoming the receiving environment for pesticide inputs. In estuaries, salinity can alter insecticide responses of exposed crustaceans. The acute toxicity of environmentally relevant doses of chlorpyrifos and imidacloprid were examined using the euryhaline amphipod Gammarus lawrencianus at 20 and 30 Practical Salinity Units (PSU). Responses were recorded every 24 h until an incipient (threshold) L(E)C50 was reached. For chlorpyrifos, LC50 ranged from 0.1 to 0.5 µg/L and was two-fold higher at 30 vs. 20 PSU at all time-points over the 96 h exposure. Imidacloprid immobility EC50 ranged from 4 to 40 µg/L over the 144 h exposure. An effect of salinity was only observed at 48 h and the EC50 values showed 1.4 times more potency at 20 PSU compared to 30 PSU. Measured concentrations of both compounds did not differ between salinities. Acetylcholinesterase activity in chlorpyrifos exposed amphipods showed no salinity effect at 96 h. We conclude that salinity level alters G. lawrencianus susceptibility to chlorpyrifos exposure, but not imidacloprid
The impact of image resolution on power, bias, and confounding: A simulation study of ambient light at night exposure
No full textBackground:
Studies of the impact of environmental pollutants on health outcomes can be compromised by mismeasured exposures or unmeasured confounding with other environmental exposures. Both problems can be exacerbated by measuring exposure from data sources with low spatial resolution. Artificial light at night, for example, is often estimated from low-resolution satellite images, which may result in substantial measurement error and increased correlation with air or noise pollution.
Methods:
Light at night exposure was considered in simulated epidemiologic studies in Vancouver, British Columbia. First, we assessed statistical power and bias for hypothetical studies that replaced true light exposure with estimates from sources with low resolution. Next, health status was simulated based on pollutants other than light exposure, and we assessed the frequency with which studies might incorrectly attribute negative health impacts to light exposure as a result of unmeasured confounding by the other environmental exposures.
Results:
When light was simulated to be the causal agent, studies relying on low-resolution data suffered from lower statistical power and biased estimates. Additionally, correlations between light and other pollutants increased as the spatial resolution of the light exposure map decreased, so studies estimating light exposure from images with lower spatial resolution were more prone to confounding.
Conclusions:
Studies estimating exposure to pollutants from data with lower spatial resolution are prone to increased bias, increased confounding, and reduced power. Studies examining effects of light at night should avoid using exposure estimates based on low-resolution maps, and should consider potential confounding with other environmental pollutants