Crohn's and Colitis Canada's 2021 Impact of COVID-19 & Inflammatory Bowel Disease in Canada: A Knowledge Translation Strategy

The prevalence of inflammatory bowel diseases (IBD), Crohn’s disease and ulcerative colitis, in Canada, is over 0.75% in 2021. Many individuals with IBD are immunocompromised. Consequently, the World Health Organization’s declaration of a global pandemic uniquely impacted those with IBD. Crohn’s and Colitis Canada (CCC) formed the COVID-19 and IBD Taskforce to provide evidence-based guidance during the pandemic to individuals with IBD and their families. The Taskforce met regularly through the course of the pandemic, synthesizing available information on the impact of COVID-19 on IBD. At first, the information was extrapolated from expert consensus guidelines, but eventually, recommendations were adapted for an international registry of worldwide cases of COVID-19 in people with IBD. The task force launched a knowledge translation initiative consisting of a webinar series and online resources to communicate information directly to the IBD community. Taskforce recommendations were posted to CCC’s website and included guidance such as risk stratification, management of immunosuppressant medications, physical distancing, and mental health. A weekly webinar series communicated critical information directly to the IBD community. During the pandemic, traffic to CCC’s website increased with 484,755 unique views of the COVID-19 webpages and 126,187 views of the 23 webinars, including their video clips. CCC’s COVID-19 and IBD Taskforce provided critical guidance to the IBD community as the pandemic emerged, the nation underwent a lockdown, the economy reopened, and the second wave ensued. By integrating public health guidance through the unique prism of a vulnerable population, CCC’s knowledge translation platform informed and protected the IBD community.

Epidemiology of morbidity and mortality in US and Canadian recreational scuba diving

OBJECTIVES

This study investigates morbidity and mortality suffered by divers in the USA and Canada.

STUDY DESIGN

Prospectively recruited probability-weighted sample for estimating the national burden of injury and a weighted retrospective survey for estimating exposure.

METHODS

The National Electronic Surveillance System and Canadian Hospitals Injury Reporting and Prevention Program (CHIRPP) were searched for scuba diving injuries. The Divers Alert Network diving fatality database was searched for deaths, and Sports and Fitness Industry Association estimates for diving were obtained from annual surveys.

RESULTS

In the USA, there were an estimated 1394 emergency department (ED) presentations annually for scuba-related injuries. The majority (80%) were treated and/or released. There were an estimated 306 million dives made by the US residents 2006-2015 and concurrently 563 recreational diving deaths, a fatality rate of 0.18 per 10⁵ dives and 1.8 per 10⁵ diver-years. There were 658 diving deaths in the US 2006-2015 and 13,943 ED presentations for scuba injuries, giving a ratio of 47 diving deaths in the USA for every 1000 ED presentations. There were 98 cases of scuba-related injuries identified in the CHIRPP data. The prevalence of scuba-related injuries for patients aged 3-17 years was 1.5 per 10⁵ cases, and the prevalence of scuba-related injuries to patients 18-62 years was 16.5 per 10⁵ cases.

DISCUSSION

In Canada and the USA, only one out of every 10,000 ED presentations is due to a scuba-related injury. That there are 47 deaths for every 1000 ED presentations for scuba injuries speaks to the relatively unforgiving environment in which scuba diving takes place. For 1.8 deaths per million recreational dives, mortality in scuba diving is nonetheless relatively low.

At-a-glance, Emergency department surveillance of thermal burns and scalds, electronic Canadian Hospitals Injury Reporting and Prevention Program, 2013

INTRODUCTION

Although fatality and hospitalization rates for burns in Canada have declined over time, less serious cases still commonly present to the emergency department (ED).

METHODS

The Canadian Hospitals Injury Reporting and Prevention Program (CHIRPP) is an injury and poisoning surveillance system administered by the Public Health Agency of Canada, operating in emergency departments of 17 hospitals.

RESULTS

Overall, cases reported in 2013 were scalds and contact burns from hot objects. The leading direct causes of scalds were hot beverages and hot water. The leading causes of contact burns were stoves/ovens and fireplaces/accessories. While the overall proportion of burns was highest among females, males comprised a higher proportion of burns from all mechanisms except scalds.

Status report - The Canadian Hospitals Injury Reporting and Prevention Program: a dynamic and innovative injury surveillance system

This status report on the Canadian Hospitals Injury Reporting and Prevention Program (CHIRPP), an emergency department-based injury and poisoning surveillance system, describes the result of migrating from a centralized data entry and coding process to a decentralized process, the web-based eCHIRPP system, in 2011. This secure system is improving the CHIRPP's overall flexibility and timeliness, which are key attributes of an effective surveillance system. The integrated eCHIRPP platform enables near real-time data entry and access, has user-friendly data management and analysis tools, and allows for easier communication and connectivity across the CHIRPP network through an online collaboration centre. Current pilot testing of automated data monitoring and trend analysis tools-designed to monitor and flag incoming data according to predefined criteria (for example, a new consumer product)-is revealing eCHIRPP's potential for providing early warnings of new hazards, issues and trends.

Molecular-scale remnants of the liquid-gas transition in supercritical polar fluids

An electronically coarse-grained model for water reveals a persistent vestige of the liquid-gas transition deep into the supercritical region. A crossover in the density dependence of the molecular dipole arises from the onset of nonpercolating hydrogen bonds. The crossover points coincide with the Widom line in the scaling region but extend farther, tracking the heat capacity maxima, offering evidence for liquidlike and gaslike state points in a "one-phase" fluid. The effect is present even in dipole-limit models, suggesting that it is common for all molecular liquids exhibiting dipole enhancement in the liquid phase.

Development of a PCR-free electrochemical point of care test for clinical detection of methicillin resistant Staphylococcus aureus (MRSA)

An MRSA assay requiring neither labeling nor amplification of target DNA has been developed. Sequence specific binding of fragments of bacterial genomic DNA is detected at femtomolar concentrations using electrochemical impedance spectroscopy (EIS). This has been achieved using systematic optimisation of probe chemistry (PNA self-assembled monolayer film on gold electrode), electrode film structure (the size and nature of the chemical spacer) and DNA fragmentation, as these are found to play an important role in assay performance. These sensitivity improvements allow the elimination of the PCR step and DNA labeling and facilitate the development of a simple and rapid point of care test for MRSA. Assay performance is then evaluated and specific direct detection of the MRSA diagnostic mecA gene from genomic DNA, extracted directly from bacteria without further treatment is demonstrated for bacteria spiked into saline (10(6) cells per mL) on gold macrodisc electrodes and into human wound fluid (10(4) cells per mL) on screen printed gold electrodes. The latter detection level is particularly relevant to clinical requirements and point of care testing where the general threshold for considering a wound to be infected is 10(5) cells per mL. By eliminating the PCR step typically employed in nucleic acid assays, using screen printed electrodes and achieving sequence specific discrimination under ambient conditions, the test is extremely simple to design and engineer. In combination with a time to result of a few minutes this means the assay is well placed for use in point of care testing.

Nonlinear optical methods for cellular imaging and localization

Of all the ways in which complex materials (including many biological systems) can be explored, imaging is perhaps the most powerful because delivering high information content directly. This is particular relevant in aspects of cellular localization where the physical proximity of molecules is crucial in biochemical processes. A great deal of effort in imaging has been spent on enabling chemically selective imaging so that only specific features are revealed. This is almost always achieved by adding fluorescent chemical labels to specific molecules. Under appropriate illumination conditions only the molecules (via their labels) will be visible. The technique is simple and elegant but does suffer from fundamental limitations: (1) the fluorescent labels may fade when illuminated (a phenomenon called photobleaching) thereby constantly decreasing signal contrast over the course of image acquisition. To combat photobleaching one must reduce observation times or apply unfavourably low excitation levels all of which reduce the information content of images; (2) the fluorescent species may be deactivated by various environmental factors (the general term is fluorescence quenching); (3) the presence of fluorescent labels may introduce unexpected complications or may interfere with processes of interest (4) Some molecules of interest cannot be labelled. In these circumstances we require a fundamentally different strategy. One of the most promising alternative is based on a technique called Coherent Anti-Stokes Raman scattering (CARS). CARS is a fundamentally more complex process than is fluorescence and the experimental procedures and optical systems required to deliver high quality CARS images are intricate. However, the rewards are correspondingly very high: CARS probes the chemically distinct vibrations of the constituent molecules in a complex system and is therefore also chemically selective as are fluorescence-based methods. Moreover,the potentially severe problems of fluorescence bleaching and quenching are circumvented and high-resolution three dimensional images can be obtained on completely unlabelled specimens. We review here aspects of CARS and Multiphoton fluorescence techniques to cellular localization and measurement.

Electronically coarse-grained model for water

We introduce an electronically coarse-grained description of water representing all long range, many-body electronic responses via an embedded quantum oscillator. Leading-order response coefficients and gas phase electrostatic moments are exactly reproduced. Molecular dynamics, using electronic path integral sampling, shows that this framework is sufficient for a realistic liquid to emerge naturally with transferability extending further to nonambient state points and to the free water surface. The model allows the strength of many-body dispersion and polarization to be adjusted independently and these are found to have significant effects on the condensed phase.

Report summary - Injury in Review, 2012 Edition: Spotlight on Road and Transport Safety

Injury in Review, 2012 Edition: Spotlight on Road and Transport Safety, the first national public health report of its kind, synthesizes road- and transport-related injury statistics from a variety of sources. It profiles injury patterns among Canadians aged up to 24 years, explains risks and protective factors, and makes recommendations for action. The findings inform the development of targeted injury prevention efforts.

Report summary - injury in review, 2012 edition: spotlight on road and transport safety

Injury in Review, 2012 Edition: Spotlight on Road and Transport Safety, the first national public health report of its kind, synthesizes road- and transport-related injury statistics from a variety of sources. It profiles injury patterns among Canadians aged up to 24 years, explains risks and protective factors, and makes recommendations for action. The findings inform the development of targeted injury prevention efforts.

Structural properties of liquid N-methylacetamide via ab initio, path integral, and classical molecular dynamics

In order to better understand the physical interactions that stabilize protein secondary structure, the neat liquid state of a peptidic fragment, N-methylacetamide (NMA), was studied using computer simulation. Three different descriptions of the molecular liquid were examined: an empirical force field treatment with classical nuclei, an empirical force field treatment with quantum mechanical nuclei, and an ab initio density functional theory (DFT) treatment. The DFT electronic structure was evaluated using the BLYP approximate functional and a plane wave basis set. The different physical effects probed by the three models, such as quantum dispersion, many-body polarization, and nontrivial charge distributions on the liquid properties, were compared. Much of the structural ordering in the liquid is characterized by hydrogen bonded chains of NMA molecules. Modest structural differences are present among the three models of liquid NMA. The average molecular dipole in the liquid under the ab initio treatment, however, is enhanced by 60% over the gas phase value.

Structure and hydrogen bonding in neat N-methylacetamide: classical molecular dynamics and Raman spectroscopy studies of a liquid of peptidic fragments

The results of classical molecular dynamics (MD) simulations and Raman spectroscopy studies of neat liquid N-methylacetamide (NMA), the simplest model system relevant to the peptides, are reported as a function of temperature and pressure. The MD simulations predict that near ambient conditions, the molecules form a hydrogen bond network consisting primarily of linear chains. Both the links between molecules within the hydrogen-bonded chains and the associations between chains are stabilized by weak methyl-donated "improper" hydrogen bonds. The three-dimensional structural motifs observed in the liquid show some similarity to protein beta-sheets. The temperature and pressure dependence of the hydrogen bond network, as probed by the mode frequency of the experimentally determined amide-I Raman band, blue shifts on heating and red shifts under compression, respectively, suggesting weakened and enhanced hydrogen bonding in response to temperature and pressure increases. Disruption of the hydrogen-bonding network is clearly observed in the simulation data as temperature is increased, whereas the improper hydrogen bonding is enhanced under compression to reduce the energetic cost of increasing the packing fraction. Because of the neglect of polarizability in the molecular model, the computed dielectric constant is underestimated compared to the experimental value, indicating that the simulation may underestimate dipolar coupling in the liquid.

Structure of Aqueous Proline via Parallel Tempering Molecular Dynamics and Neutron Diffraction

The structure of aqueous L-proline amino acid has been the subject of much debate centering on the validity of various proposed models, differing widely in the extent to which local and long-range correlations are present. Here, aqueous proline is investigated by atomistic, replica exchange molecular dynamics simulations, and the results are compared to neutron diffraction and small angle neutron scattering (SANS) data, which have been reported recently (McLain, S.; Soper, A.; Terry, A.; Watts, A. J. Phys. Chem. B 2007, 111, 4568). Comparisons between neutron experiments and simulation are made via the static structure factor S(Q) which is measured and computed from several systems with different H/D isotopic compositions at a concentration of 1:20 molar ratio. Several different empirical water models (TIP3P, TIP4P, and SPC/E) in conjunction with the CHARMM22 force field are investigated. Agreement between experiment and simulation is reasonably good across the entire Q range although there are significant model-dependent variations in some cases. In general, agreement is improved slightly upon application of approximate quantum corrections obtained from gas-phase path integral simulations. Dimers and short oligomeric chains formed by hydrogen bonds (frequently bifurcated) coexist with apolar (hydrophobic) contacts. These emerge as the dominant local motifs in the mixture. Evidence for long-range association is more equivocal: No long-range structures form spontaneously in the MD simulations, and no obvious low-Q signature is seen in the SANS data. Moreover, associations introduced artificially to replicate a long-standing proposed mesoscale structure for proline correlations as an initial condition are annealed out by parallel tempering MD simulations. However, some small residual aggregates do remain, implying a greater degree of long-range order than is apparent in the SANS data.

The stability and characteristics of a DNA Holliday junction switch

A Holliday junction (HJ) consists of four DNA double helices, with a branch point discontinuity at the intersection of the component strands. At low ionic strength, the HJ adopts an open conformation, with four widely spaced arms, primarily due to strong electrostatic repulsion between the phosphate groups on the backbones. At high ionic strength, screening of this repulsion induces a switch to a more compact (closed) junction conformation. Fluorescent labelling with dyes placed on the HJ arms allows this conformational switch to be detected optically using fluorescence resonance energy transfer (FRET), producing a sensitive fluorescent output of the switch state. This paper presents a systematic and quantitative survey of the switch characteristics of such a labelled HJ. A short HJ (arm length 8 bp) is shown to be prone to dissociation at low switching ion concentration, whereas an HJ of arm length 12 bp is shown to be stable over all switching ion concentrations studied. The switching characteristics of this HJ have been systematically and quantitatively studied for a variety of switching ions, by measuring the required ion concentration, the sharpness of the switching transition and the fluorescent output intensity of the open and closed states. This stable HJ is shown to have favourable switch characteristics for a number of inorganic switching ions, making it a promising candidate for use in nanoscale biomolecular switch devices.

Time-Resolved FRET and FLIM of Four-way DNA Junctions

Conformational transitions in a 4-way DNA junction when titrated with ionic solutions are studied using time-resolved fluorescence resonance energy transfer. Parameters characterising the transition in terms of critical ion concentration (c1/2) and the Hill coefficient for ion binding are obtained by fitting a simple two-state model using steady-state spectra. Data obtained from a fluorescence lifetime plate reader and analysed by fitting a single exponential to donor fluorescence lifetime decays are shown to be in good agreement with the parameters obtained from steady-state measurements. Fluorescence lifetimes, however, offer advantages, particularly in being independent of fluorophore concentration, output intensity, inhomogeneity in the excitation source and output wavelength. We demonstrate preliminary FRET-FLIM images of DNA junction solutions obtained using a picosecond gated CCD which are in agreement with results from a fluorescence lifetime plate reader. The results suggest that time-resolved FRET-FLIM is sensitive to subtle structural changes and may be useful in assays based on 4-way DNA junctions.

Segregation in aqueous methanol enhanced by cooling and compression

Molecular segregation in methanol-water mixtures is studied across a wide concentration range as a function of temperature and pressure. Cluster distributions obtained from both neutron diffraction and molecular dynamics simulations point to significantly enhanced segregation as the mixtures are cooled or compressed. This evolution toward greater molecular heterogenity in the mixture accounts for the observed changes in the water-water radial distribution function and there are indications also of a change in the topology of the water clusters. The observed behavior is consistent with an approach to an upper critical solution point. Such a point would appear to be "hidden" below the freezing line, thereby precluding observation of the two-fluid region.

Methanol-water solutions: A bi-percolating liquid mixture

An extensive series of neutron diffraction experiments and molecular dynamics simulations has shown that mixtures of methanol and water exhibit extended structures in solution despite the components being fully miscible in all proportions. Of particular interest is a concentration region (methanol mole fraction between 0.27 and 0.54) where both methanol and water appear to form separate, percolating networks. This is the concentration range where many transport properties and thermodynamic excess functions reach extremal values. The observed concentration dependence of several of these material properties of the solution may therefore have a structural origin.

Single Molecule Fluorescence Imaging and Its Application to the Study of DNA Condensation

Single molecule fluorescence imaging incorporated with optical tweezers and a laminar flow cell has been used to monitor the kinetic process of DNA condensation induced by spermidine. It was found that at least two steps were involved in the condensation process of the hydrodynamically-stretched linear DNA; a lag period followed by a rapid collapse of DNA. The lag time increased with the flow speed and the collapse time remained short within the range of the flow speed studied. The effect of salt concentration on the condensation process was examined, and the results suggest that the longer lag time observed in the higher salt buffer probably results from the displacement of bound cations and rearrangement of spermidine on the DNA. The flow-speed dependence of the lag time suggests that a nucleation event at the free end of the DNA, i.e. formation of a loop, may play a vital role in the kinetic process of condensation.

Molecular segregation observed in a concentrated alcohol-water solution

When a simple alcohol such as methanol or ethanol is mixed with water, the entropy of the system increases far less than expected for an ideal solution of randomly mixed molecules. This well-known effect has been attributed to hydrophobic headgroups creating ice-like or clathrate-like structures in the surrounding water, although experimental support for this hypothesis is scarce. In fact, an increasing amount of experimental and theoretical work suggests that the hydrophobic headgroups of alcohol molecules in aqueous solution cluster together. However, a consistent description of the details of this self-association is lacking. Here we use neutron diffraction with isotope substitution to probe the molecular-scale structure of a concentrated alcohol water mixture (7:3 molar ratio). Our data indicate that most of the water molecules exist as small hydrogen-bonded strings and clusters in a 'fluid' of close-packed methyl groups, with water clusters bridging neighbouring methanol hydroxyl groups through hydrogen bonding. This behaviour suggests that the anomalous thermodynamics of water alcohol systems arises from incomplete mixing at the molecular level and from retention of remnants of the three-dimensional hydrogen-bonded network structure of bulk water.

Colloid-liquid-crystal composites: An unusual soft solid

Mixing model colloidal particles with a thermotropic nematic liquid crystal results in a soft solid with significant storage modulus (G' approximately 10(3)-10(5) Pa). The soft solid comprises a network of particle aggregates, formed by the exclusion of particles from emergent nematic domains as the mixture is cooled below the isotropic-nematic transition. The unusually high storage modulus of the colloid-liquid-crystal composites may be due to the local frustration of nematic order within the particle aggregates. The birefringent soft solid is potentially important as a switchable electro-optical material that can be readily handled and processed.

Mitral regurgitation after atrioventricular node catheter ablation for atrial fibrillation and heart failure: acute hemodynamic features

BACKGROUND

Radiofrequency catheter ablation of the atrioventricular node and pacemaker insertion have been associated with occasional development of mitral regurgitation (MR). Ventricular pacing might result in MR if (1) left ventricular (LV) compliance is decreased and/or (2) mitral valve leaflet apposition is disturbed. We studied acute hemodynamic changes resulting from initiation of ventricular pacing in patients undergoing ablation.

METHODS AND RESULTS

Thirteen patients (10 men and 3 women) with a mean age of 73.4 +/- 8. 6 years, with chronic atrial fibrillation and congestive heart failure, had permanent ventricular pacemaker insertion with lead placement at the right ventricular (RV) apex. The following hemodynamic recordings were obtained before ablation (during atrial fibrillation) and then immediately after ablation (during RV pacing): heart rate, mean arterial pressure, LV end-diastolic pressure (LVEDP), mean pulmonary capillary wedge pressure, V-wave amplitude, and cardiac index. Presence of MR was assessed by V-wave amplitude and the results of LV angiography. In patients who had MR, recordings were also obtained during temporary ventricular pacing from the RV outflow tract (RVOT). As a group there were no significant changes in any hemodynamic measurement. Before ablation, mild MR by LV angiogram was present in 5 patients, but none had large V-wave amplitude. After ablation, mild MR was present by LV angiogram in 6 patients, and in 3 of these patients large V-wave amplitude developed (mean amplitude 42.7 +/- 2.2 mm Hg; assigned to group 1). This was associated with a rise in LVEDP in 1 patient (consistent with reduced LV compliance), but LVEDP was unchanged in the other 2 patients (suggesting abnormal mitral valve leaflet apposition). All patients in group 1 exhibited a fall in V-wave amplitude when the pacing site was moved to the RVOT.

CONCLUSIONS

Both reduced LV compliance and disturbed mitral valve leaflet apposition contribute to MR after ablation. MR is reduced by pacing from the RVOT.

Effect of antiphospholipid antibodies in women undergoing in-vitro fertilization: role of heparin and aspirin

To describe the prevalence of antiphospholipid antibodies in women undergoing in-vitro fertilization (IVF) and to determine if heparin and aspirin affect implantation rates, 191 women with a history of infertility undergoing IVF were prospectively tested for antiphospholipid antibodies. This was a two-centre, non-randomized comparison of women with positive antiphospholipid antibodies receiving heparin and aspirin versus standard treatment. An enzyme-linked immunosorbent assay, with referenced standards and known positive and negative sera on each plate, was utilized to measure antibodies to cardiolipin, phosphatidylinositol, phosphatidylglycerol, phosphatidylserine and phosphatidylethanolamine. Statistical analyses of results included analysis of variance and Fisher's two-tailed exact test. Antiphospholipid antibodies were detected in 18.8% of patients undergoing IVF compared with only 5.5% in the 200 normal controls, 26% in 200 women with recurrent pregnancy loss, and 32% in 200 women with systemic lupus erythematosus. In conclusion, antiphospholipid antibodies were found more frequently in women undergoing IVF than in the normal control population. Although implantation rates appeared higher in the group of women treated with heparin and aspirin, no statistically significant differences were detected in implantation, pregnancy and ongoing pregnancy rates between those who received standard therapy and those treated with heparin and aspirin.