Publications by authors named "Christie S"

We have developed a novel real-time quaking-induced conversion RT-QuIC-based assay to detect alpha-synuclein aggregation in brain and cerebrospinal fluid from dementia with Lewy bodies and Parkinson's disease patients. This assay can detect alpha-synuclein aggregation in Dementia with Lewy bodies and Parkinson's disease cerebrospinal fluid with sensitivities of 92% and 95%, respectively, and with an overall specificity of 100% when compared to Alzheimer and control cerebrospinal fluid. Patients with neuropathologically confirmed tauopathies (progressive supranuclear palsy; corticobasal degeneration) gave negative results.

View Article and Find Full Text PDF

We present the first comparison between assays that use resistive pulses or rectification ratios on a tunable pore platform. We compare their ability to quantify the cancer biomarker Vascular Endothelial Growth Factor (VEGF). The first assay measures the electrophoretic mobility of aptamer modified nanoparticles as they traverse the pore.

View Article and Find Full Text PDF

Traumatic spinal cord injury (SCI) represents a significant burden of illness, but it is relatively uncommon and heterogeneous, making it challenging to achieve sufficient subject enrollment in clinical trials of therapeutic interventions for acute SCI. The Rick Hansen Spinal Cord Injury Registry (RHSCIR) is a national SCI Registry that enters patients with SCI from acute-care centers across Canada. To predict the feasibility of conducting clinical trials of acute SCI within Canada, we have applied the inclusion/exclusion criteria of six previously conducted SCI trials to the RHSCIR data set and generated estimates of how many Canadian persons would have been eligible theoretically for enrollment in these studies.

View Article and Find Full Text PDF

In this paper we present a framework for the semi-automatic extraction of medical entities from referral letters and use them to transcribe a case report form. Our framework offers the functionality to: (a) extract the medical entity from the unstructured referral letters, (b) classify them according to their semantic type, and (c) transcribe a case report form based on the extracted information from the referral letter. We take a semantic text analytics approach where SNOMED-CT ontology is used to both classify referral concepts and to establish semantic similarities between referral concepts and CRF elements.

View Article and Find Full Text PDF

Background: The ideal aortic valve substitute in young and middle-aged adults remains unknown. We sought to compare the long-term outcomes of patients undergoing the Ross procedure and those receiving a mechanical aortic valve replacement (AVR).

Methods: From 1990 to 2014, 258 patients underwent a Ross procedure and 1444 had a mechanical AVR at a single institution.

View Article and Find Full Text PDF

The formation of smart Lab-on-a-Chip (LOC) devices featuring integrated sensing optics is currently hindered by convoluted and expensive manufacturing procedures. In this work, a series of 3D-printed LOC devices were designed and manufactured via stereolithography (SL) in a matter of hours. The spectroscopic performance of a variety of optical fibre combinations were tested, and the optimum path length for performing Ultraviolet-visible (UV-vis) spectroscopy determined.

View Article and Find Full Text PDF

Objective: Current selection methods for neurosurgical residents fail to include objective measurements of bimanual psychomotor performance. Advancements in computer-based simulation provide opportunities to assess cognitive and psychomotor skills in surgically naive populations during complex simulated neurosurgical tasks in risk-free environments. This pilot study was designed to answer 3 questions: (1) What are the differences in bimanual psychomotor performance among neurosurgical residency applicants using NeuroTouch? (2) Are there exceptionally skilled medical students in the applicant cohort? and (3) Is there an influence of previous surgical exposure on surgical performance?

Design: Participants were instructed to remove 3 simulated brain tumors with identical visual appearance, stiffness, and random bleeding points.

View Article and Find Full Text PDF

Objective: To provide evidence-based treatment recommendations for adults with acute migraine who require treatment with injectable medication in an emergency department (ED). We addressed two clinically relevant questions: (1) Which injectable medications should be considered first-line treatment for adults who present to an ED with acute migraine? (2) Do parenteral corticosteroids prevent recurrence of migraine in adults discharged from an ED?

Methods: The American Headache Society convened an expert panel of authors who defined a search strategy and then performed a search of Medline, Embase, the Cochrane database and clinical trial registries from inception through 2015. Identified articles were rated using the American Academy of Neurology's risk of bias tool.

View Article and Find Full Text PDF

Selective laser melting (SLM) has previously been shown to be a viable method for fabricating biomedical implants; however, the surface chemistry of SLM fabricated parts is poorly understood. In this study, X-ray photoelectron spectroscopy (XPS) was used to determine the surface chemistries of (a) SLM as-fabricated (SLM-AF) Ti6Al4V and (b) SLM fabricated and mechanically polished (SLM-MP) Ti6Al4V samples and compared with (c) traditionally manufactured (forged) and mechanically polished Ti6Al4V samples. The SLM-AF surface was observed to be porous with an average surface roughness (Ra) of 17.

View Article and Find Full Text PDF

Coagulopathy following injury is common and it predicts poor outcomes and increased mortality. For many decades, coagulopathy in trauma was considered as an iatrogenic phenomenon, and clinical practice focused on a resuscitation strategy using large volume crystalloid and packed red blood cells. The discovery of Acute Traumatic Coagulopathy as a distinct pathophysiologic state coupled with a transition towards balanced product resuscitation has fundamentally changed the paradigm of trauma care and represents one of the most active areas of current research in the field of trauma.

View Article and Find Full Text PDF

A new type of photocrosslinkable polycaprolactone (PCL) based ink that is suitable for three-dimensional (3D) inkjet printing has been developed. Photocrosslinkable Polycaprolactone dimethylacrylate (PCLDMA) was synthesized and mixed with poly(ethylene glycol) diacrylate (PEGDA) to prepare an ink with a suitable viscosity for inkjet printing. The ink performance under different printing environments, initiator concentrations, and post processes was studied.

View Article and Find Full Text PDF

Not all samples of evidence are equally conclusive: Diverse evidence is more representative than narrow evidence. Prior research showed that children did not use sample diversity in evidence selection tasks, indiscriminately choosing diverse or narrow sets (tiger-mouse; tiger-lion) to learn about animals. This failure is not due to a general deficit of inductive reasoning, but reflects children's belief about the category and property at test.

View Article and Find Full Text PDF

Introduction: Many encephalitis survivors can benefit from rehabilitation. However, there is currently no comprehensive review describing rehabilitation intervention outcomes among children and adults with infectious encephalitis. This is a protocol for a systematic review that will summarise the current literature on outcomes following rehabilitative interventions among children and adults with infectious encephalitis.

View Article and Find Full Text PDF

OBJECTIVE Severe bleeding during neurosurgical operations can result in acute stress affecting the bimanual psychomotor performance of the operator, leading to surgical error and an adverse patient outcome. Objective methods to assess the influence of acute stress on neurosurgical bimanual psychomotor performance have not been developed. Virtual reality simulators, such as NeuroTouch, allow the testing of acute stress on psychomotor performance in risk-free environments.

View Article and Find Full Text PDF

Study Design: Modified-Delphi expert consensus method.

Objective: The aim of this study was to develop competence-based spine fellowship curricula as a set of learning goals through expert consensus methodology in order to provide an educational tool for surgical educators and trainees. Secondarily, we aimed to determine potential differences among specialties in their rating of learning objectives to defined curriculum documents.

View Article and Find Full Text PDF

An initial study of processing bioresorbable polycaprolactone (PCL) through material jetting was conducted using a Fujifilm Dimatix DMP-2830 material printer. The aim of this work was to investigate a potential solvent based method of jetting polycaprolactone. Several solvents were used to prepare a PCL solvent based ink and 1, 4-dioxane was chosen with the consideration of both solubility and safety.

View Article and Find Full Text PDF

Relational reasoning is a hallmark of sophisticated cognition in humans. Does it exist in other primates? Despite some affirmative answers, there appears to be a wide gap in relational ability between humans and other primates--even other apes. Here, we test one possible explanation for this gap, motivated by developmental research showing that young humans often fail at relational reasoning tasks because they focus on objects instead of relations.

View Article and Find Full Text PDF

Broad HIV-1 genetic diversity in Cameroon provides a unique opportunity to monitor HIV-1 evolution and allows the detection of novel strains. We have genetically characterized the HIV-1 subtypes found in 156 samples from 90 drug-naive subjects in Yaoundé, Cameroon collected from 2011 to 2013, using phylogenetic analysis of regions in gag and pol. We identified subtypes CRF02_AG (64.

View Article and Find Full Text PDF

TRAF-interacting protein with forkhead-associated domain B (TIFAB) is a haploinsufficient gene in del(5q) myelodysplastic syndrome (MDS). Deletion of Tifab results in progressive bone marrow (BM) and blood defects, including skewed hematopoietic stem/progenitor cell (HSPC) proportions and altered myeloid differentiation. A subset of mice transplanted with Tifab knockout (KO) HSPCs develop a BM failure with neutrophil dysplasia and cytopenia.

View Article and Find Full Text PDF

While it is widely recognized that thinking is somehow costly, involving cognitive effort and producing mental fatigue, these costs have alternatively been assumed to exist, treated as the brain's assessment of lost opportunities, or suggested to be metabolic but with implausible biological bases. We present a model of cognitive cost based on the novel idea that the brain senses and plans for longer-term allocation of metabolic resources by purposively conserving brain activity. We identify several distinct ways the brain might control its metabolic output, and show how a control-theoretic model that models decision-making with an energy budget can explain cognitive effort avoidance in terms of an optimal allocation of limited energetic resources.

View Article and Find Full Text PDF

The advent of synoptic operative reports has revolutionized how clinical data are captured at the time of care. In this article, an electronic synoptic operative report for spinal cord injury was implemented using interoperable standards, HL7 and Systematized Nomenclature of Medicine-Clinical Terms. Subjects (N = 10) recruited for a pilot study completed recruitment and feedback questionnaires, and produced both an electronic synoptic operative report for spinal cord injury report and a dictated narrative operative report for an actual patient case.

View Article and Find Full Text PDF

Objective: To compare the use of a generic molecular assay to 'standard' investigations used to assist the diagnosis of late onset bacterial sepsis in very low birth weight infants (VLBW, <1500 g).

Methods: VLBW infants, greater than 48 hours of age, who were clinically suspected to have sepsis were investigated using standard tests (full blood count, C-reactive protein (at presentation) and blood culture), in addition, blood was taken for a universal molecular assay (16S rRNA reverse transcriptase PCR) for comparison. Clinical data were recorded during the suspected infection episode.

View Article and Find Full Text PDF

Background: Citizen science, scientific research conducted by non-specialists, has the potential to facilitate biomedical research using available large-scale data, however validating the results is challenging. The Cell Slider is a citizen science project that intends to share images from tumors with the general public, enabling them to score tumor markers independently through an internet-based interface.

Methods: From October 2012 to June 2014, 98,293 Citizen Scientists accessed the Cell Slider web page and scored 180,172 sub-images derived from images of 12,326 tissue microarray cores labeled for estrogen receptor (ER).

View Article and Find Full Text PDF