Objective: To assess the diagnostic accuracy and cost-effectiveness of fetal fibronectin (fFN) and cervical phosphorylated insulin-like growth factor binding protein-1 (phIGFBP-1) tests, individually and in combination, to predict preterm delivery within 48 hours, 7 days and 14 days in symptomatic women.
Method: We selected women in Victoria, British Columbia, who presented between January 2008 and December 2017 at <34 weeks gestation at intermediate risk for labour (intact membrane, cervical dilatation <3 cm, and >6 contractions per hour). We calculated sensitivity, specificity, and positive and negative predictive values (PPV, NPV) for independent and concurrent testing and conducted a cost-effectiveness analysis to ensure appropriate test utilization.
Background: Orthopedic braces made by Computer-Aided Design and Manufacturing and numerical simulation were shown to improve spinal deformities correction in adolescent idiopathic scoliosis while using less material. Simulations with BraceSim (Rodin4D, Groupe Lagarrigue, Bordeaux, France) require a sagittal radiograph, not always available. The objective was to develop an innovative modeling method based on a single coronal radiograph and surface topography, and assess the effectiveness of braces designed with this approach.
View Article and Find Full Text PDFOrganobismuthines are an attractive class of organometallic reagents that can be accessed from inexpensive and nontoxic bismuth salts. Triarylbismuthines are particularly interesting due to their air and moisture stability and high functional group tolerance. We report herein a detailed study on the preparation of highly functionalized triarylbismuth reagents by triple functional group manipulation and their use in palladium- and copper-catalyzed C-, N-, and O-arylation reactions.
View Article and Find Full Text PDFThe development of general and more atom-economical catalytic processes for Friedel-Crafts alkylations of unactivated arenes is an important objective of interest for the production of pharmaceuticals and commodity chemicals. Ferroceniumboronic acid hexafluoroantimonate salt (1) was identified as a superior air- and moisture-tolerant catalyst for direct Friedel-Crafts alkylations of a variety of slightly activated and neutral arenes with stable and readily available primary and secondary benzylic alcohols. Compared to the use of classical metal-catalyzed alkylations with toxic benzylic halides, this methodology employs exceptionally mild conditions to provide a wide variety of unsymmetrical diarylmethanes and other 1,1-diarylalkane products in high yield with good to high regioselectivity.
View Article and Find Full Text PDFThe O-arylation of 1,2-aminoalcohols using functionalized triarylbismuth reagents is reported. The reaction can be performed using substoichiometric amounts of copper acetate and operates under mild conditions. Good functional group tolerance is observed, giving access to a range of β-aryloxyamines.
View Article and Find Full Text PDFAdolescent idiopathic scoliosis (AIS) is a musculoskeletal pathology. It is a complex spinal curvature in a 3-D space that also affects the appearance of the trunk. The clinical follow-up of AIS is decisive for its management.
View Article and Find Full Text PDFBackground: This paper presents a method that registers MRIs acquired in prone position, with surface topography (TP) and X-ray reconstructions acquired in standing position, in order to obtain a 3D representation of a human torso incorporating the external surface, bone structures, and soft tissues.
Methods: TP and X-ray data are registered using landmarks. Bone structures are used to register each MRI slice using an articulated model, and the soft tissue is confined to the volume delimited by the trunk and bone surfaces using a constrained thin-plate spline.
IEEE J Biomed Health Inform
March 2013
Besides the spinal deformity, scoliosis modifies notably the general appearance of the trunk resulting in trunk rotation, imbalance and asymmetries which constitutes patients' major concern. Existing classifications of scoliosis, based on the type of spinal curve as depicted on radiographs, are currently used to guide treatment strategies. Unfortunately, even though a perfect correction of the spinal curve is achieved, some trunk deformities remain, making patients dissatisfied with the treatment received.
View Article and Find Full Text PDFObjective: To determine scoliosis curve types using non invasive surface acquisition, without prior knowledge from X-ray data.
Methods: Classification of scoliosis deformities according to curve type is used in the clinical management of scoliotic patients. In this work, we propose a robust system that can determine the scoliosis curve type from non invasive acquisition of the 3D back surface of the patients.
Comput Med Imaging Graph
July 2012
This paper presents a magnetic resonance image (MRI)/X-ray spine registration method that compensates for the change in the curvature of the spine between standing and prone positions for scoliotic patients. MRIs in prone position and X-rays in standing position are acquired for 14 patients with scoliosis. The 3D reconstructions of the spine are then aligned using an articulated model which calculates intervertebral transformations.
View Article and Find Full Text PDFStudy Design: Reliability study.
Objectives: To assess between-acquisition reliability of new multilevel trunk cross sections measurements, in order to define what is a real change when comparing 2 trunk surface acquisitions of a same patient, before and after surgery or throughout the clinical monitoring.
Summary Of Background Data: Several cross-sectional surface measurements have been proposed in the literature for noninvasive assessment of trunk deformity in patients with adolescent idiopathic scoliosis (AIS).
IEEE Trans Biomed Eng
April 2012
3-D assessment of scoliotic deformities relies on an accurate 3-D reconstruction of bone structures from biplanar X-rays, which requires a precise detection and matching of anatomical structures in both views. In this paper, we propose a novel semiautomated technique for detecting complete scoliotic rib borders from PA-0° and PA-20° chest radiographs, by using an edge-following approach with multiple-path branching and oriented filtering. Edge-following processes are initiated from user starting points along upper and lower rib edges and the final rib border is obtained by finding the most parallel pair among detected edges.
View Article and Find Full Text PDFCobb angles and apical vertebral rotations (AVR) are two of the main scoliosis deformity parameters which spinal instrumentation and fusion techniques aim to reduce. Despite this importance, current surgical positioning techniques do not allow the reduction of these parameters. Two new surgical frame accessory prototypes have been developed: (1) a lateral leg displacer (LLD) allows lateral bending of a patient's legs up to 75° in either direction and (2) a pelvic torsion device (PTD) which allows transverse plane twisting of a patient's pelvis at 30° in either direction while raising the thoracic cushion, opposite to the raised side of the pelvis, by 5 cm.
View Article and Find Full Text PDFObjective: The objective of this study was to use finite element model (FEM) simulations and experimental testing to study the relationship between lower limb positioning for surgeries of the spine and changes in sagittal curves.
Methods: Four volunteers underwent lower limb flexibility and range of motion testing before being placed prone on a new surgical frame where lateral radiographs of their spines were taken in positions of hip flexion (average 48 degrees) and extension (average 13 degrees). Personalized FEMs were created representing each volunteer's spine, rib cage, pelvis, and lower limbs.
Objective: To study the impact of patient-specific prone positioning on the sagittal and coronal curves of scoliotic spines, including the impact of various patient and surgical frame factors.
Summary Of Background Data: Prone operative positioning has been shown to impact the geometry of various individual spinal segments. Its impact on global spinal geometry and influential factors remains unknown.
J Obstet Gynaecol Can
December 2010
Background: Rituximab is a novel therapy for immune thrombocytopenic purpura (ITP); however, information about its safety in pregnancy is limited. This case illustrates the successful use of rituximab to treat pregnancy-associated ITP.
Case: A 34-year-old woman presented with severe ITP at 23 weeks' gestation.
Stud Health Technol Inform
September 2010
A multi-functional positioning frame (MFPF) has been developed which includes a number of positioning features allowing for hip flexion and extension, thorax vertical displacement, lateral leg displacement, pelvic torsion and thorax lateral displacement. The objective of this study was to develop a method allowing for optimized combined use of the MFPF features. Finite element models (FEMs) representing the osseo-ligamentous structures of the spine, ribcage, pelvis and lower limbs, including muscles, were created for three different curve types (main thoracic, double major, and triple major) using a radiographic bi-planar reconstruction technique.
View Article and Find Full Text PDFPatient positioning is an important step in spinal surgeries. Many surgical frames allow for lumbar lordosis modulation due to lower limb displacement, however, they do not include a feature which can modulate thoracic kyphosis. A sternum vertical displacer (SVD) prototype has been developed which can increase a subject's thoracic kyphosis relative to the neutral prone position on a surgical frame.
View Article and Find Full Text PDFAmong the external manifestations of scoliosis, the rib hump, which is associated with the ribs' deformities and rotations, constitutes the most disturbing aspect of the scoliotic deformity for patients. A personalized 3-D model of the rib cage is important for a better evaluation of the deformity, and hence, a better treatment planning. A novel method for the 3-D reconstruction of the rib cage, based only on two standard radiographs, is proposed in this paper.
View Article and Find Full Text PDFInteins are phylogenetically diverse self-splicing proteins that are of great functional, evolutionary, biotechnological, and medical interest. To address the relationship between intein structure and function, particularly with respect to regulating the splicing reaction, and to groom inteins for application, we developed a phage display system to extend current in vivo selection for enhanced intein function to selection in vitro. We thereby isolated inteins that can function under excursions in temperature, pH, and denaturing environment.
View Article and Find Full Text PDFThe backbone and side chain resonance assignments of an engineered intein based on Mycobacterium tuberculosis RecA have been determined based on triple-resonance experiments with the uniformly [(13)C,(15)N]-labeled protein.
View Article and Find Full Text PDFStudy Design: Evaluation of a novel Dynamic Positioning Frame (DPF) for scoliosis surgery to improve presurgical correction.
Objective: To assess a DPF for scoliosis surgery and demonstrate how its design offers additional presurgical correction of the 3-dimensional deformity.
Summary Of Background Data: Patient positioning is an important step in scoliosis surgery.
Stud Health Technol Inform
October 2008
The objective of this study was to develop a finite element model (FEM) in order to study the relationship between hip flexion/extension and the sagittal curves of the spine. A previously developed FEM of the spine, rib cage and pelvis personalized to the 3D reconstructed geometry of a patient using biplanar radiographs was adapted to include the lower limbs including muscles. Simulations were performed to determine: the relationship between hip flexion / extension and lumbar lordosis / thoracic kyphosis, the mechanism of transfer between hip flexion / extension and pelvic rotation, and the influence that knee bending, muscle stiffness, and muscle mass have on the degree to which sagittal spinal curves are modified due to lower limb positioning.
View Article and Find Full Text PDFI-TevI is a modular intron-encoded endonuclease, consisting of an N-terminal catalytic domain and a C-terminal DNA-binding domain, joined by a 75 amino acid linker. This linker can be divided into three regions, starting at the N terminus: the deletion-intolerant (DI) region; the deletion-tolerant (DT) region; and a zinc finger, which acts as a distance determinant for cleavage. To further explore linker function, we generated deletion and substitution mutants that were tested for their preference to cleave at a particular distance or at the correct sequence.
View Article and Find Full Text PDFIEEE Trans Biomed Eng
February 2008
Finite element (FE) models are very efficient tools to study internal stresses in human structures that induce severe pressure sores. Unfortunately, methods currently used to generate FE models are not suitable for clinical application involving wheelchair users. A clinical-oriented method, based on calibrated-biplanar radiographs, was therefore developed to generate a subject-specific FE model of the buttocks in a non-weighted sitting position.
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