Cholesterol nucleation time in gallbladder bile of patients with solitary or multiple cholesterol gallstones

Patients with multiple cholesterol gallbladder stones have been found to be at a higher risk for the recurrence of gallstones after successful nonsurgical treatment than those with a solitary stone. Cholesterol gallstone recurrence, like primary gallstone formation, probably involves a triple defect with supersaturation, abnormally rapid nucleation of cholesterol in bile and altered gallbladder motor function. We investigated whether the increased recurrence rate of patients with multiple stones might be caused by more rapid nucleation. Therefore the time required for cholesterol monohydrate crystals to appear in ultracentrifuged bile of patients with solitary (n = 71) or multiple (n = 42) cholesterol gallstones was determined. The cholesterol nucleation time was significantly (p 4 days) nucleation time. However, no difference in the cholesterol saturation index was found between the bile samples from patients with solitary stones and the bile samples from patients with multiple stones (1.55 ± 0.65 vs. 1.54 ± 0.59, mean ± S.D., respectively). The more rapid cholesterol nucleation in gallbladder bile may, therefore, be the major risk factor causing the higher percentage of stone recurrence in patients with multiple cholesterol stones as compared with patients with solitary cholesterol stones

A Phase IV Study of Thromboembolic and Bleeding Events Following Hip and Knee Arthroplasty Using Oral Factor Xa Inhibitor

AbstractBackgroundMultiple randomized controlled trials have documented the effectiveness of rivaroxaban in the prevention of venous thromboembolism up to 1-month following total joint arthroplasty. However, the effectiveness and safety of rivaroxaban in the real-world setting, outside of the strict protocols used by randomized clinical trials, are unknown.MethodsThis was a prospective, observational, noninterventional, phase IV study of 3914 consecutive patients who underwent total joint arthroplasty from June 2010 to December 2012. Patients were treated with rivaroxaban 10 mg by mouth daily starting postoperative day 1 and continued for 15 days. Participants were followed up in clinic at 6 weeks and contacted by telephone at 12 weeks. The primary outcome of interest was symptomatic venous thromboembolism; secondary outcomes included bleeding events, transfusion requirements, and death.ResultsThe incidence of symptomatic deep venous thrombosis at 3 months was 0.5% (n = 18). Only 1 deep venous thrombosis event occurred within 7 days of surgery. The incidence of symptomatic pulmonary embolism (PE) at 3 months was 0.7% (n = 28). Thirteen PEs (46%) occurred within 7 days of surgery. The rate of major bleeding while on prophylaxis was 0.1%. Only 5% of patients received a blood transfusion. No deaths were attributed to thromboembolic events.ConclusionThis prospective, observational, phase IV study demonstrates that rivaroxaban appears to protect patients against symptomatic PE and is not associated with major bleeding events when used in a real-world setting as described

Pregabalin reduces postoperative opioid consumption and pain for 1 week after hospital discharge, but does not affect function at 6 weeks or 3 months after total hip arthroplasty

BACKGROUND: This study examined whether a perioperative regimen of pregabalin added to celecoxib improved pain scores and functional outcomes postdischarge up to 3 months after total hip arthroplasty (primary outcome) and acute postoperative pain and adverse effects (secondary outcomes). METHODS: One hundred and eighty-four patients were enrolled in a randomized, double-blind, placebo-controlled study. Two hours before receiving a spinal anaesthetic and undergoing surgery, patients received celecoxib 400 mg p.o. and were randomly assigned to receive either pregabalin 150 mg p.o. or placebo p.o. After surgery, patients received pregabalin 75 mg or placebo twice daily in hospital and for 7 days after discharge. Patients also received celecoxib 200 mg every 12 h for 72 h and morphine i.v. patient-controlled analgesia for 24 h. Pain and function were assessed at baseline, 6 weeks, and 3 months after surgery. RESULTS: There was no difference between groups in physical function or incidence and intensity of chronic pain 3 months after total hip arthroplasty. The pregabalin group used less morphine [mean (sd): 39.85 (28.1) mg] than the placebo group [54.01 (31.2) mg] in the first 24 h after surgery (P<0.01). Pain scores were significantly lower in the pregabalin group vs the placebo group on days 1-7 after hospitaldischarge, and the pregabalin group required less adjunctive opioid medication (Percocet) 1 week after hospital discharge (P<0.05). CONCLUSIONS: Perioperative administration of pregabalin did not improve pain or physical function at 6 weeks or 3 months after total hip arthroplasty. Perioperative administration of pregabalin decreased opioid consumption in hospital and reduced daily pain scores and adjunct opioid consumption for 1 week after discharge.Department of Anaesthesia at the University of Toronto (Merit Awards to H.C. and C.M.); Canadian Institute of Health Research Fellowship (to H.C.); Canada Research Chair in Health Psychology at York University (to J. Katz); Pfizer Canada (physician-initiated peer-reviewed Neuropathic Pain Competition)

Assessing stability and change of four performance measures: a longitudinal study evaluating outcome following total hip and knee arthroplasty

BACKGROUND: Physical performance measures play an important role in the measurement of outcome in patients undergoing hip and knee arthroplasty. However, many of the commonly used measures lack information on their psychometric properties in this population. The purposes of this study were to examine the reliability and sensitivity to change of the six minute walk test (6MWT), timed up and go test (TUG), stair measure (ST), and a fast self-paced walk test (SPWT) in patients with hip or knee osteoarthritis (OA) who subsequently underwent total joint arthroplasty. METHODS: A sample of convenience of 150 eligible patients, part of an ongoing, larger observational study, was selected. This included 69 subjects who had a diagnosis of hip OA and 81 diagnosed with knee OA with an overall mean age of 63.7 ± 10.7 years. Test-retest reliability, using Shrout and Fleiss Type 2,1 intraclass correlations (ICCs), was assessed preoperatively in a sub-sample of 21 patients at 3 time points during the waiting period prior to surgery. Error associated with the measures' scores and the minimal detectable change at the 90% confidence level was determined. A construct validation process was applied to evaluate the measures' abilities to detect deterioration and improvement at two different time points post-operatively. The standardized response mean (SRM) was used to quantify change for all measures for the two change intervals. Bootstrapping was used to estimate the 95% confidence intervals (CI) for the SRMs. RESULTS: The ICCs (95% CI) were as follows: 6MWT 0.94 (0.88,0.98), TUG 0.75 (0.51, 0.89), ST 0.90 (0.79, 0.96), and the SPWT 0.91 (0.81, 0.97). Standardized response means varied from .79 to 1.98, being greatest for the ST and 6MWT over the studied time intervals. CONCLUSIONS: The test-retest estimates of the 6MWT, ST, and the SPWT met the requisite standards for making decisions at the individual patient level. All measures were responsive to detecting deterioration and improvement in the early postoperative period

Modeling early recovery of physical function following hip and knee arthroplasty

BACKGROUND: Information on early recovery after arthroplasty is needed to help benchmark progress and make appropriate decisions concerning patient rehabilitation needs. The purpose of this study was to model early recovery of physical function in patients undergoing total hip (THA) and knee (TKA) arthroplasty, using physical performance and self-report measures. METHODS: A sample of convenience of 152 subjects completed testing, of which 69 (mean age: 66.77 ± 8.23 years) underwent THA and 83 (mean age: 60.25 ± 11.19 years) TKA. Postoperatively, patients were treated using standardized care pathways and rehabilitation protocols. Using a repeated measures design, patients were assessed at multiple time points over the first four postoperative months. Outcome measures included the Lower Extremity Function Scale (LEFS), the physical function subscale of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC PF), the 6 minute walk test (6 MWT), timed up and go test (TUG) and a timed stair test (ST). Average recovery curves for each of the measures were characterized using hierarchical linear modeling. Predictors of recovery were sequentially modeled after validation of the basic developmental models. RESULTS: Slopes of recovery were greater in the first 6 to 9 weeks with a second-degree polynomial growth term (weeks squared) providing a reasonable fit for the data over the study interval. Different patterns of recovery were observed between the self-report measures of physical function and the performance measures. In contrast to the models for the WOMAC PF and the LEFS, site of arthroplasty was a significant predictor (p = 0.001) in all of the physical performance measure models with the patients post TKA initially demonstrating higher function. Site of arthroplasty (p = 0.025) also predicted the rate of change for patients post THA and between 9 to 11 weeks after surgery, the THA group surpassed the function of the patients post TKA. CONCLUSION: Knowledge about the predicted growth curves will assist clinicians in referencing patient progress, and determining the critical time points for measuring change. The study has contributed further evidence to highlight the benefit of using physical performance measures to learn about the patients' actual level of disability

An Investigation into Mathematics for Undergraduate Engineering Education to Improve Student Competence in Important Mathematics Skills

Several convictions premise this work. First, that mathematics is a crucial part of the toolset required by engineers if they are to practice responsibly; how else can one predict consequences of innovative engineering actions and designs? Also, that faculty perceive that students often find mathematics neither helpful nor essential, but instead find it frustrating, painful and discouraging. This work shows that this perception of a gap is not only valid and widespread within engineering, and across the various departments, but is widespread for different backgrounds and across various mathematics subjects. Given that elucidating the importance of mathematics is crucial to engineering, is there an issue with student competence in mathematics? In seeking to answer this question, this endeavour is intended to be climactic, because it is not merely knowing that mathematics is essential, knowing if there is a struggle is imperative, which helps understand if a change is needed to teach mathematics to engineers and to open the doors for future discourse. This project uses a mixed-methods study, explicitly using a post-positivist, pragmatic research paradigm completed through an explanatory sequential framework. The 2017-2018 academic year was used to collect data. The findings suggest faculty agree that mathematics plays an important role in engineering, that students' need to be better at general and specific mathematics skills, and that revisiting how one teaches mathematics to engineering students is required. In an effort to provide students with a better learning environment, it is helpful to revisit the engineering mathematics curriculum. Engineering practice is dynamic, technologies change, even becoming obsolete. The same should be valid for how to impart the curriculum to students, which should encourage modernizing teaching methods to improve knowledge transfer for student success. Through the lenses of pedagogy, instructional design, and cognitive psychology offer opportunities to improve the existing curriculum as it relates to student achievement. Thus, one of the predominant outcomes of this project is to provide a study of best practices for mathematics education for engineering students, along with the perceptions of faculty about these same practices.Ph.D

Mind the Gap: A preliminary Investigation into the Gaps Between Faculty and Student Expectations in Engineering Mathematics Instruction

© 2019 American Society for Engineering EducationThe connection between mathematics and engineering, that is the ability for students to transfer their knowledge between mathematics courses and other engineering courses, has been documented as difficult for students (Holmegaard, Madsen, & Ulriksen, 2016; Basitere & Ivala, 2015; Klingbeil, Rattan, Raymer, Reynolds, & Mercer, 2009; Willcox & Bounova, 2004; Harper, Baker, & Grzybowski, 2013). By looking at faculty views regarding the mathematics that is learned while in undergraduate engineering, I argue that mathematics plays an important role in undergraduate engineering, yet faculty often believe that the students are inadequately equipped with the mathematics skills they need, which is essential because mathematics is foundational for engineering design. Through a mixed-methods study over the course of the 2017-2018 academic year, we sought to answer the following questions: To what extent does mathematics play an important role in undergraduate engineering education? Do professors believe that undergraduate engineering students can competently apply mathematic principles in engineering classes? And finally, how should mathematics be taught as it relates to undergraduate engineering? The initial findings suggest faculty believe that mathematics plays an important role in engineering, calculus being the most important, with linear algebra and statistics also playing a significant role. Faculty also believe that mathematics should be taught as a means of communicating (i.e. through mathematical modelling). Faculty also believe that students’ competence ranks lower than the importance of the general and specific mathematics skills. Finally, faculty were unsure if mathematics should be taught toward the abstract or the applied, but in general, believe that it should have some examples that are tied to engineering. Mathematics instruction to engineering students is often taught through two lenses, an abstract or an applied lens. While both categories of mathematics are essential in undergraduate engineering, a third paradigm for teaching is offered, an engineering mathematics lens, which combines both the necessity for an understanding both in abstract and applied mathematics, but relates examples to all facets of engineering. An engineering mathematics lens could offer part of a solution to helping to close the gap in faculty and student expectations as it relates to mathematics instruction in engineering education

Measuring the Connection Between Mathematics and Engineering

Mathematics forms the foundation for all the engineering disciplines. Students have trouble transferring this mathematical knowledge from their mathematics classes to the rest of their undergraduate engineering classes. This study is borne out of a desire to ‘be better,' to endeavour always to try to improve, but first, you need to know where one the starting point. The authors are also passionate about mathematics as it relates to engineering. Anecdotally the authors had heard that both students and faculty were disappointed and aggravated with the current status of mathematics teaching in undergraduate engineering. With no known study in Canada looking at how mathematics connects with engineering the authors went down the path to find out how strong the connection between mathematics and undergraduate engineering is at the University of Toronto. Through a mixed-method survey, the goal was to measure respondents’ (i.e. The teaching staff) views on the importance of and students’ competence of both mathematical topics and specific mathematic skills. A survey was administered in the 2017 fall semester to all of those who teach in the Faculty of Applied Science at the University of Toronto. The first part of the survey used a 5-point scale, the second part of the survey had open-ended questions. The responses to the 5-point scale questions demonstrate that the selected mathematic topics and specific skills were all seen as important and that the students’ competence was lower than their rated importance. The open ended-questions asked for respondents definitions and views as they related to abstract, applied, and engineering mathematics