136 research outputs found
Comparative genetics of Enterococcus faecalis intestinal tissue isolates before and after surgery in a rat model of colon anastomosis.
We have recently demonstrated that collagenolytic Enterococcus faecalis plays a key and causative role in the pathogenesis of anastomotic leak, an uncommon but potentially lethal complication characterized by disruption of the intestinal wound following segmental removal of the colon (resection) and its reconnection (anastomosis). Here we hypothesized that comparative genetic analysis of E. faecalis isolates present at the anastomotic wound site before and after surgery would shed insight into the mechanisms by which collagenolytic strains are selected for and predominate at sites of anastomotic disruption. Whole genome optical mapping of four pairs of isolates from rat colonic tissue obtained following surgical resection (herein named "pre-op" isolates) and then 6 days later from the anastomotic site (herein named "post-op" isolates) demonstrated that the isolates with higher collagenolytic activity formed a distinct cluster. In order to perform analysis at a deeper level, a single pair of E. faecalis isolates (16A pre-op and 16A post-op) was selected for whole genome sequencing and assembled using a hybrid assembly algorithm. Comparative genomics demonstrated absence of multiple gene clusters, notably a pathogenicity island in the post-op isolate. No differences were found in the fsr-gelE-sprE genes (EF1817-1822) responsible for regulation and production of collagenolytic activity. Analysis of unique genes among the 16A pre-op and post-op isolates revealed the predominance of transporter systems-related genes in the pre-op isolate and phage-related and hydrolytic enzyme-encoding genes in the post-op isolate. Despite genetic differences observed between pre-op and post-op isolates, the precise genetic determinants responsible for their differential expression of collagenolytic activity remains unknown
The gradient of meteorological and chemical variables across the tropopause
The downward transport of air through the tropopause can bring substantial amounts of ozone and reactive nitrogen into the upper troposphere. In this cold region of the atmosphere, O3 is particularly effective as a greenhouse gas. As part of the North Dakota Thunderstorm Project in June 1989, the NCAR Sabreliner made five flights through the tropopause. We measured ozone, nitric oxide (NO), total reactive nitrogen (NO(y)), carbon monoxide (CO), and water vapor (H2)), and took grab samples for hydrocarbon (HC) analysis. Hydrocarbons, CO, and H2O, species with sources primarily at the earth's surface, showed a strong concentration decrease with increasing altitude, while O3 and NO(y), species with a source in the stratosphere, showed a strong concentration increase with increasing altitude. Stratospheric concentrations of NO(x), NO(y), and H2O were all high relative to winter observations made during NASA's AASE. We suggest that midlatitude thunderstorms may inject wet, NO-rich air into the lower stratosphere. Calculation based on measured ratios of NO(x) and NO(y) to O3 yield a total flux of reactive nitrogen from the Northern Hemisphere stratosphere into the troposphere of 1 to 2 Tg(N) yr(exp -1) with about 8 percent in the form of NO(x). This value is higher than reported estimates of total stratospheric nitrogen fixation
The 2020 release of the ExoMol database:Molecular line lists for exoplanet and other hot atmospheres
The ExoMol database (www.exomol.com) provides molecular data for
spectroscopic studies of hot atmospheres. While the data is intended for
studies of exoplanets and other astronomical bodies, the dataset is widely
applicable. The basic form of the database is extensive line lists; these are
supplemented with partition functions, state lifetimes, cooling functions,
Land\'e g-factors, temperature-dependent cross sections, opacities, pressure
broadening parameters, -coefficients and dipoles. This paper presents the
latest release of the database which has been expanded to consider 80 molecules
and 190 isotopologues totaling over 700 billion transitions. While the
spectroscopic data is concentrated at infrared and visible wavelengths,
ultraviolet transitions are being increasingly considered in response to
requests from observers. The core of the database comes from the ExoMol project
which primarily uses theoretical methods, albeit usually fine-tuned to
reproduce laboratory spectra, to generate very extensive line lists for studies
of hot bodies. The data has recently been supplemented by line lists deriving
from direct laboratory observations, albeit usually with the use of ab initio
transition intensities. A major push in the new release is towards accurate
characterisation of transition frequencies for use in high resolution studies
of exoplanets and other bodies
Beyond gene-disease validity: capturing structured data on inheritance, allelic requirement, disease-relevant variant classes, and disease mechanism for inherited cardiac conditions
Background:
As the availability of genomic testing grows, variant interpretation will increasingly be performed by genomic generalists, rather than domain-specific experts. Demand is rising for laboratories to accurately classify variants in inherited cardiac condition (ICC) genes, including secondary findings.
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Methods:
We analyse evidence for inheritance patterns, allelic requirement, disease mechanism and disease-relevant variant classes for 65 ClinGen-curated ICC gene-disease pairs. We present this information for the first time in a structured dataset, CardiacG2P, and assess application in genomic variant filtering.
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Results:
For 36/65 gene-disease pairs, loss of function is not an established disease mechanism, and protein truncating variants are not known to be pathogenic. Using the CardiacG2P dataset as an initial variant filter allows for efficient variant prioritisation whilst maintaining a high sensitivity for retaining pathogenic variants compared with two other variant filtering approaches.
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Conclusions:
Access to evidence-based structured data representing disease mechanism and allelic requirement aids variant filtering and analysis and is a pre-requisite for scalable genomic testing
Aerobic exercise in adolescents with obesity: preliminary evaluation of a modular training program and the modified shuttle test
BACKGROUND: Increasing activity levels in adolescents with obesity requires the development of exercise programs that are both attractive to adolescents and easily reproducible. The aim of this study was to develop a modular aerobic training program for adolescents with severe obesity, with a focus on variety, individual targets and acquiring physical skills. We report here the effects on aerobic fitness from a pilot study. Furthermore, we examined the feasibility of the modified shuttle test (MST) as an outcome parameter for aerobic fitness in adolescents with severe obesity. METHODS: Fifteen adolescents from an inpatient body weight management program participated in the aerobic training study (age 14.7 ± 2.1 yrs, body mass index 37.4 ± 3.5). The subjects trained three days per week for 12 weeks, with each session lasting 30–60 minutes. The modular training program consisted of indoor, outdoor and swimming activities. Feasibility of the MST was studied by assessing construct validity, test-retest reliability and sensitivity to change. RESULTS: Comparing pretraining and end of training period showed large clinically relevant and significant improvements for all aerobic indices: e.g. VO(2 peak )17.5%, effect size (ES) 2.4; W(max )8%, ES 0.8. In addition, a significant improvement was found for the efficiency of the cardiovascular system as assessed by the oxygen pulse (15.8%, ES 1.6). Construct validity, test-retest reliability and sensitivity to change of the MST were very good. MST was significantly correlated with VO(2 peak )(r = 0.79) and W(max )(r = 0.84) but not with anthropometric measures. The MST walking distance improved significantly by 32.5%, ES 2.5. The attendance rate at the exercise sessions was excellent. CONCLUSION: This modular, varied aerobic training program has clinically relevant effects on aerobic performance in adolescents with severe obesity. The added value of our aerobic training program for body weight management programs for adolescents with severe obesity should be studied with a randomized trial. This study further demonstrated that the MST is a reliable, sensitive and easy to administer outcome measure for aerobic fitness in adolescent body weight management trials
Impact of SARS-Cov-2 infection in patients with hypertrophic cardiomyopathy : results of an international multicentre registry
To describe the natural history of SARS-CoV-2 infection in patients with hypertrophic cardiomyopathy (HCM) compared with a control group and to identify predictors of adverse events. Three hundred and five patients [age 56.6 ± 16.9 years old, 191 (62.6%) male patients] with HCM and SARS-Cov-2 infection were enrolled. The control group consisted of 91 131 infected individuals. Endpoints were (i) SARS-CoV-2 related mortality and (ii) severe clinical course [death or intensive care unit (ICU) admission]. New onset of atrial fibrillation, ventricular arrhythmias, shock, stroke, and cardiac arrest were also recorded. Sixty-nine (22.9%) HCM patients were hospitalized for non-ICU level care, and 21 (7.0%) required ICU care. Seventeen (5.6%) died: eight (2.6%) of respiratory failure, four (1.3%) of heart failure, two (0.7%) suddenly, and three (1.0%) due to other SARS-CoV-2-related complications. Covariates associated with mortality in the multivariable were age {odds ratio (OR) per 10 year increase 2.25 [95% confidence interval (CI): 1.12-4.51], P = 0.0229}, baseline New York Heart Association class [OR per one-unit increase 4.01 (95%CI: 1.75-9.20), P = 0.0011], presence of left ventricular outflow tract obstruction [OR 5.59 (95%CI: 1.16-26.92), P = 0.0317], and left ventricular systolic impairment [OR 7.72 (95%CI: 1.20-49.79), P = 0.0316]. Controlling for age and sex and comparing HCM patients with a community-based SARS-CoV-2 cohort, the presence of HCM was associated with a borderline significant increased risk of mortality OR 1.70 (95%CI: 0.98-2.91, P = 0.0600). Over one-fourth of HCM patients infected with SARS-Cov-2 required hospitalization, including 6% in an ICU setting. Age and cardiac features related to HCM, including baseline functional class, left ventricular outflow tract obstruction, and systolic impairment, conveyed increased risk of mortality
2018 Research & Innovation Day Program
A one day showcase of applied research, social innovation, scholarship projects and activities.https://first.fanshawec.ca/cri_cripublications/1005/thumbnail.jp
Beyond gene-disease validity: capturing structured data on inheritance, allelic-requirement, disease-relevant variant classes, and disease mechanism for inherited cardiac conditions
BACKGROUND: As availability of genomic testing grows, variant interpretation will increasingly be performed by genomic generalists, rather than domain-specific experts. Demand is rising for laboratories to accurately classify variants in inherited cardiac condition (ICC) genes, including as secondary findings. METHODS: We analyse evidence for inheritance patterns, allelic requirement, disease mechanism and disease-relevant variant classes for 65 ClinGen-curated ICC gene-disease pairs. We present this information for the first time in a structured dataset, CardiacG2P, and assess application in genomic variant filtering. RESULTS: For 36/65 gene-disease pairs, loss-of-function is not an established disease mechanism, and protein truncating variants are not known to be pathogenic. Using CardiacG2P as an initial variant filter allows for efficient variant prioritisation whilst maintaining a high sensitivity for retaining pathogenic variants compared with two other variant filtering approaches. CONCLUSIONS: Access to evidence-based structured data representing disease mechanism and allelic requirement aids variant filtering and analysis and is pre-requisite for scalable genomic testing
Basic science232. Certolizumab pegol prevents pro-inflammatory alterations in endothelial cell function
Background: Cardiovascular disease is a major comorbidity of rheumatoid arthritis (RA) and a leading cause of death. Chronic systemic inflammation involving tumour necrosis factor alpha (TNF) could contribute to endothelial activation and atherogenesis. A number of anti-TNF therapies are in current use for the treatment of RA, including certolizumab pegol (CZP), (Cimzia ®; UCB, Belgium). Anti-TNF therapy has been associated with reduced clinical cardiovascular disease risk and ameliorated vascular function in RA patients. However, the specific effects of TNF inhibitors on endothelial cell function are largely unknown. Our aim was to investigate the mechanisms underpinning CZP effects on TNF-activated human endothelial cells. Methods: Human aortic endothelial cells (HAoECs) were cultured in vitro and exposed to a) TNF alone, b) TNF plus CZP, or c) neither agent. Microarray analysis was used to examine the transcriptional profile of cells treated for 6 hrs and quantitative polymerase chain reaction (qPCR) analysed gene expression at 1, 3, 6 and 24 hrs. NF-κB localization and IκB degradation were investigated using immunocytochemistry, high content analysis and western blotting. Flow cytometry was conducted to detect microparticle release from HAoECs. Results: Transcriptional profiling revealed that while TNF alone had strong effects on endothelial gene expression, TNF and CZP in combination produced a global gene expression pattern similar to untreated control. The two most highly up-regulated genes in response to TNF treatment were adhesion molecules E-selectin and VCAM-1 (q 0.2 compared to control; p > 0.05 compared to TNF alone). The NF-κB pathway was confirmed as a downstream target of TNF-induced HAoEC activation, via nuclear translocation of NF-κB and degradation of IκB, effects which were abolished by treatment with CZP. In addition, flow cytometry detected an increased production of endothelial microparticles in TNF-activated HAoECs, which was prevented by treatment with CZP. Conclusions: We have found at a cellular level that a clinically available TNF inhibitor, CZP reduces the expression of adhesion molecule expression, and prevents TNF-induced activation of the NF-κB pathway. Furthermore, CZP prevents the production of microparticles by activated endothelial cells. This could be central to the prevention of inflammatory environments underlying these conditions and measurement of microparticles has potential as a novel prognostic marker for future cardiovascular events in this patient group. Disclosure statement: Y.A. received a research grant from UCB. I.B. received a research grant from UCB. S.H. received a research grant from UCB. All other authors have declared no conflicts of interes
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