Publications by authors named "Scott Robson"

Objectives: Communimetric screening tools convey functional impairment and action required, helping clinicians identify and communicate patient's needs and actions within a measurement framework. We examined the feasibility of using the HEADS-ED Under 6, a communimetric mental health (MH) and developmental screening and triage tool for children under 6, within 1Call1Click.ca, a regional coordinated access and navigation program in Eastern Ontario.

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Background: CT-guided percutaneous transthoracic needle biopsy is the primary method for diagnosing lung lesions. Widely accepted validated risk prediction models are yet to be developed. A recently published study conducted at Grampians Health Services (GHS) developed two risk prediction models for predicting pneumothorax and intercostal catheter (ICC) insertion.

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Interferon-stimulated gene-15 (ISG15) is an interferon-induced protein with two ubiquitin-like (Ubl) domains linked by a short peptide chain and is a conjugated protein of the ISGylation system. Similar to ubiquitin and other Ubls, ISG15 is ligated to its target proteins through a series of E1, E2, and E3 enzymes known as Uba7, Ube2L6/UbcH8, and HERC5, respectively. Ube2L6/UbcH8 plays a central role in ISGylation, underscoring it as an important drug target for boosting innate antiviral immunity.

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The current standard method for amino acid signal identification in protein NMR spectra is sequential assignment using triple-resonance experiments. Good software and elaborate heuristics exist, but the process remains laboriously manual. Machine learning does help, but its training databases need millions of samples that cover all relevant physics and every kind of instrumental artifact.

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The multinuclear nonheme iron-dependent oxidases (MNIOs) are a rapidly growing family of enzymes involved in the biosynthesis of ribosomally synthesized, posttranslationally modified peptide natural products (RiPPs). Recently, a secreted virulence factor from nontypeable (NTHi) was found to be expressed from an operon, which we designate the operon, that also encodes an MNIO. Here, we show by Mössbauer spectroscopy that the MNIO HvfB contains a triiron cofactor.

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G-protein coupled receptors (GPCRs) are the largest class of membrane proteins encoded in the human genome with high pharmaceutical relevance and implications to human health. These receptors share a prevalent architecture of seven transmembrane helices followed by an intracellular, amphipathic helix 8 (H8) and a disordered C-terminal tail (Ctail). Technological advancements have led to over 1000 receptor structures in the last two decades, yet frequently H8 and the Ctail are conformationally heterogeneous or altogether absent.

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The neurotensin receptor 1 (NTS) is a G protein-coupled receptor (GPCR) with promise as a drug target for the treatment of pain, schizophrenia, obesity, addiction, and various cancers. A detailed picture of the NTS structural landscape has been established by X-ray crystallography and cryo-EM and yet, the molecular determinants for why a receptor couples to G protein versus arrestin transducers remain poorly defined. We used CH-methionine NMR spectroscopy to show that binding of phosphatidylinositol-4,5-bisphosphate (PIP2) to the receptor's intracellular surface allosterically tunes the timescale of motions at the orthosteric pocket and conserved activation motifs - without dramatically altering the structural ensemble.

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Interferon-stimulated gene-15 (ISG15) is an interferon-induced protein with two ubiquitin-like (Ubl) domains linked by a short peptide chain, and the conjugated protein of the ISGylation system. Similar to ubiquitin and other Ubls, ISG15 is ligated to its target proteins through a series of E1, E2, and E3 enzymes known as Uba7, Ube2L6/UbcH8, and HERC5, respectively. Ube2L6/UbcH8 plays a literal central role in ISGylation, underscoring it as an important drug target for boosting innate antiviral immunity.

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Nuclear magnetic resonance (NMR) studies have revealed that fast methyl sidechain dynamics can report on entropically-driven allostery. Yet, NMR applications have been largely limited to the super-microsecond motional regimes of G protein-coupled receptors (GPCRs). We use C-methionine chemical shift-based global order parameters to test if ligands affect the fast dynamics of a thermostabilized GPCR, neurotensin receptor 1 (NTS).

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Fluorine ( F) offers several distinct advantages for biomolecular nuclear magnetic resonance spectroscopy such as no background signal, 100% natural abundance, high sensitivity, and a large chemical shift range. Exogenous cysteine-reactive F-probes have proven especially indispensable for characterizing large, challenging systems that are less amenable to other isotopic labeling strategies such as G protein-coupled receptors. As fluorine linewidths are inherently broad, limiting reactions with offsite cysteines is critical for spectral simplification and accurate deconvolution of component peaks-especially when analyzing systems with intermediate to slow timescale conformational exchange.

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Using a discrete, intracellular F nuclear magnetic resonance (NMR) probe on transmembrane helix 6 of the neurotensin receptor 1 (NTS1), we aim to understand how ligands and transducers modulate the receptor's structural ensemble in a solution. For apo NTS1, F NMR spectra reveal an ensemble of at least three conformational substates (one inactive and two active-like) in equilibrium that exchange on the millisecond to second timescale. Dynamic NMR experiments reveal that these substates follow a linear three-site exchange process that is both thermodynamically and kinetically remodeled by orthosteric ligands.

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Although the concepts of nonuniform sampling (NUS​​​​​​​) and non-Fourier spectral reconstruction in multidimensional NMR began to emerge 4 decades ago , it is only relatively recently that NUS has become more commonplace. Advantages of NUS include the ability to tailor experiments to reduce data collection time and to improve spectral quality, whether through detection of closely spaced peaks (i.e.

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Accurate rotational correlation times ([Formula: see text]) are critical for quantitative analysis of fast timescale NMR dynamics. As molecular weights increase, the classic derivation of [Formula: see text] using transverse and longitudinal relaxation rates becomes increasingly unsuitable due to the non-trivial contribution of remote dipole-dipole interactions to longitudinal relaxation. Derivations using cross-correlated relaxation experiments, such as TRACT, overcome these limitations but are erroneously calculated in 65% of the citing literature.

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Introduction: To retrospectively evaluate the incidence of and the risk factors for pneumothorax and intercostal catheter insertion (ICC) after CT-guided lung biopsy and to generate a risk prediction model for developing a pneumothorax and requiring an ICC.

Methods: 255 CT-guided lung biopsies performed for 249 lesions in 249 patients from August 2014 to August 2019 were retrospectively analysed using multivariate logistic regression analysis. Risk prediction models were established using backward stepwise variable selection and likelihood ratio tests and were internally validated using split-sample methods.

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Nonuniform sampling was first proposed more than 40 years ago as an alternate method for sampling two-dimensional NMR data was initially pursued by only a small number of scientists. However, it has been gradually adopted after it was shown that major gains in measuring time and spectrum resolution can be obtained. Furthermore, migration of NMR software to the Unix environment facilitated development of new processing tools, and there is now a selection of programs available that yield high-quality reconstructions of NUS data.

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The Bloch-Siegert shift is a phenomenon in NMR spectroscopy and atomic physics in which the observed resonance frequency is changed by the presence of an off-resonance applied field. In NMR, it occurs especially in the context of homonuclear decoupling. Here we develop a practical method for homonuclear decoupling that avoids inducing Bloch-Siegert shifts.

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Backbone resonance assignment is a critical first step in the investigation of proteins by NMR. This is traditionally achieved with a standard set of experiments, most of which are not optimal for large proteins. Of these, HNCA is the most sensitive experiment that provides sequential correlations.

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Non-Uniform Sampling has the potential to exploit the optimal resolution of high-field NMR instruments. This is not possible in 3D and 4D NMR experiments when using traditional uniform sampling due to the long overall measurement time. Nominally, uniformly sampled time domain data acquired to a maximum evolution time t can be extended to high resolution via a virtual maximum evolution time t* while extrapolating with linear prediction or iterative soft thresholding (IST).

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Recognizing that the object-directed actions of others are governed by goals and intentions is a crucial component of human interaction. These actions often occur rapidly and without explanation, yet we learn from and predict the actions of others with remarkable speed and accuracy, even during the first year of life. This review paper will serve as a bridge between several disparate literatures that, we suggest, can each contribute to our understanding of how infants interpret action.

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In bacteria, an ensemble of alkyl hydroperoxide reductase subunits C (AhpC) and F (AhpF) is responsible for scavenging H2O2. AhpC donates electrons for the reduction of H2O2, which are provided after NADH oxidation by AhpF. The latter contains an N-terminal domain (NTD), catalyzing the electron transfer from NADH via a FAD of the C-terminal domain (CTD) into AhpC.

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Bacterial division begins with the formation of a contractile protein ring at midcell, which constricts the bacterial envelope to generate two daughter cells. The central component of the division ring is FtsZ, a tubulin-like protein capable of self-assembling into filaments which further associate into a higher order structure known as the Z ring. Proteins that bind to FtsZ play a crucial role in the formation and regulation of the Z ring.

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Multi-dimensional NMR spectra have traditionally been processed with the fast Fourier transformation (FFT). The availability of high field instruments, the complexity of spectra of large proteins, the narrow signal dispersion of some unstructured proteins, and the time needed to record the necessary increments in the indirect dimensions to exploit the resolution of the highfield instruments make this traditional approach unsatisfactory. New procedures need to be developed beyond uniform sampling of the indirect dimensions and reconstruction methods other than the straight FFT are necessary.

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Current literature suggests that a large proportion of chest X-rays (CXRs) performed in emergency department (ED) patients with chest pain and suspected acute coronary syndrome (ACS) are unnecessary. The Canadian ACS Guidelines aim to guide clinicians in the appropriate use of CXR within this patient population. This study determined the prevalence of clinically significant CXR abnormalities and assessed the utility of the guidelines in a population of ED patients with chest pain and suspected ACS.

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It is well established that non-uniform sampling (NUS) allows acquisition of multi-dimensional NMR spectra at a resolution that cannot be obtained with traditional uniform acquisition through the indirect dimensions. However, the impact of NUS on the signal-to-noise ratio (SNR) and sensitivity are less well documented. SNR and sensitivity are essential aspects of NMR experiments as they define the quality and extent of data that can be obtained.

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