Publications by authors named "Robert Hayden"

Objective: To develop and externally validate a prediction model for severe cisplatin associated acute kidney injury (CP-AKI).

Design: Multicenter cohort study.

Setting: Six geographically diverse major academic cancer centers across the US.

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Over 2 years have passed since the start of the COVID-19 pandemic, which has claimed millions of lives. Unlike the early days of the pandemic, when management decisions were based on extrapolations from in vitro data, case reports and case series, clinicians are now equipped with an armamentarium of therapies based on high-quality evidence. These treatments are spread across seven main therapeutic categories: anti-inflammatory agents, antivirals, antithrombotics, therapies for acute hypoxaemic respiratory failure, anti-SARS-CoV-2 (neutralizing) antibody therapies, modulators of the renin-angiotensin-aldosterone system and vitamins.

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The hepatitis C virus (HCV) p7 protein is required for infectious virus production via its role in assembly and ion channel activity. Although NMR structures of p7 have been reported, the location of secondary structural elements and orientation of the p7 transmembrane domains differ among models. Furthermore, the p7 structure-function relationship remains unclear.

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Piscidins were the first antimicrobial peptides discovered in the mast cells of vertebrates. While two family members, piscidin 1 (p1) and piscidin 3 (p3), have highly similar sequences and α-helical structures when bound to model membranes, p1 generally exhibits stronger antimicrobial and hemolytic activity than p3 for reasons that remain elusive. In this study, we combine activity assays and biophysical methods to investigate the mechanisms underlying the cellular function and differing biological potencies of these peptides, and report findings spanning three major facets.

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Pregnancy rates and the desire to conceive are increasing among women living with HIV in Africa. However, attempts to conceive may increase the risk of HIV transmission or reinfection. A better understanding of factors influencing fertility desires would significantly contribute to programmes to meet the reproductive needs of women living with HIV.

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While antimicrobial peptides (AMPs) have been widely investigated as potential therapeutics, high-resolution structures obtained under biologically relevant conditions are lacking. Here, the high-resolution structures of the homologous 22-residue long AMPs piscidin 1 (p1) and piscidin 3 (p3) are determined in fluid-phase 3:1 phosphatidylcholine/phosphatidylglycerol (PC/PG) and 1:1 phosphatidylethanolamine/phosphatidylglycerol (PE/PG) bilayers to identify molecular features important for membrane destabilization in bacterial cell membrane mimics. Structural refinement of (1)H-(15)N dipolar couplings and (15)N chemical shifts measured by oriented sample solid-state NMR and all-atom molecular dynamics (MD) simulations provide structural and orientational information of high precision and accuracy about these interfacially bound α-helical peptides.

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Objective: Advancing life expectancy with the increased prevalence of aortic valve degenerative disease brings the need for an aortic bioprosthesis with excellent haemodynamic performance and comparable durability. The Mitroflow bioprosthesis has been on the worldwide market, except in the United States, since 1982, while the current model (1991) has only recently gained regulatory approval in the latter country. This study was primarily performed to determine the durability of the current Mitroflow bioprosthesis.

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Background: Many health care systems now use priority wait lists for scheduling elective coronary artery bypass grafting (CABG) surgery, but there have not yet been any direct estimates of reductions in in-hospital mortality rate afforded by ensuring that the operation is performed within recommended time periods.

Methods: We used a population-based registry to identify patients with established coronary artery disease who underwent isolated CABG in British Columbia, Canada. We studied whether postoperative survival during hospital admission for CABG differed significantly among patients who waited for surgery longer than the recommended time, 6 weeks for patients needing semi-urgent surgery and 12 weeks for those needing non-urgent surgery.

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Epiploic appendagitis is a very rare condition that results from acute inflammation of an appendix epiploica. We report a case involving a 24-year-old woman who presented to the emergency department with abdominal pain localized to the left lower quadrant. The patient was diagnosed with epiploic appendagitis, which was confirmed through findings obtained from a contrast-study computed tomography of the abdomen.

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Background: Currently there are no direct estimates of mortality reduction afforded by coronary-artery bypass grafting (CABG) that take into account the deaths among patients for whom coronary revascularization was indicated but who did not undergo the treatment. The objective of this analysis was to compare survival after the treatment decision between patients who underwent CABG and those who remained untreated.

Methods: We used a population-based registry to identify patients with established coronary artery disease who were to undergo first-time isolated CABG.

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Background: Studies have shown patients who are delayed for surgical cardiac revascularization are faced with increased risks of symptom deterioration and death. This could explain the observation that operative mortality among persons undergoing coronary artery bypass surgery (CABG) is higher among women than men. However, in jurisdictions that employ priority wait lists to manage access to elective cardiac surgery, there is little information on whether women wait longer than men for CABG.

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Objectives: To examine outcomes following all first coronary revascularization procedures, isolated coronary artery bypass graft surgery (CABG) and percutaneous coronary intervention (PCI) on British Columbia (BC) resident adults from 1995 to 2001.

Methods: CABG and PCI data were obtained from the BC Cardiac Registry, and mortality data were obtained from the BC Vital Statistics Agency. Analysis was performed by annual cohorts, and the rates reported are unadjusted.

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Objective: To compare the cumulative incidence of emergency surgery between two groups of patients classified according to the length of wait lists at the time of their registration for coronary artery bypass grafting (CABG) and to test for significant differences in the risk of emergency surgery resulting from registration on a longer wait list.

Methods: A prospective study of all adult British Columbia residents who registered to undergo isolated CABG. We compared the time-dependent cumulative incidence for undergoing planned surgery through unplanned emergency admission before or during a certain wait-list week between two categories of wait-list size.

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Background: In deciding where to undergo coronary-artery bypass grafting, the length of surgical wait lists is often the only information available to cardiologists and their patients. Our objective was to compare the cumulative incidence for death on the wait list according to the length of wait lists at the time of registration for the operation.

Methods: The study cohort included 8966 patients who registered to undergo isolated coronary-artery bypass grafting (82.

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Background: The detrimental effect of delaying surgical revascularization has been estimated in randomized trials and observational studies. It has been argued that the Kaplan-Meier method used in quantifying the hazard of delayed treatment is not appropriate for summarizing the probability of competing outcomes. Therefore, we sought to improve the estimates of the risk of death associated with delayed surgical treatment of coronary artery disease.

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Background: Priority wait lists are common for managing access to cardiac surgery in publicly funded health systems. We evaluated whether longer delays contribute to the probability of death before surgery among patients prioritized into the less urgent category.

Methods: We studied records of 9233 patients registered for isolated coronary artery bypass graft (CABG) in British Columbia, Canada.

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Objective: To determine whether the probability of undergoing coronary bypass surgery within a certain time was related to the number of patients on the wait list at registration for the operation in a publicly funded health system.

Methods: A prospective cohort study comparing waiting times among patients registered on wait lists at the hospitals delivering adult cardiac surgery. For each calendar week, the list size, the number of new registrations, and the number of direct admissions immediately after angiography characterized the demand for surgery.

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Background: The proportion of patients who undergo surgery within a clinically safe time is an important performance indicator in health systems that use wait lists to manage access to care. However, little is known about chances of on-time surgery according to variations in existing demand. We sought to determine what proportion of patients have had late coronary bypass surgery after registration on wait lists of different size in a network of hospitals with uniform standards for timing of surgery.

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Background: In British Columbia, Canada, all necessary medical services are funded publicly. Concerned with growing wait lists in the mid-1990s, the provincial government started providing extra funding for coronary artery bypass grafting (CABG) operations annually. Although aimed at improving access, it is not known whether supplementary funding changed the time that patients spent on wait lists for CABG.

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The Canadian trial of physiologic pacing (CTOPP), published in 2000, demonstrated a reduction in atrial fibrillation (AF), stroke and death with preservation of atrioventricular synchrony, though only the lower rate of AF was statistically significant. The purpose of this study was to determine the effect of CTOPP on pacing mode selection in our region. The British Columbia Cardiac Registry contains prospectively entered data covering a population of 4 millions (M) and 17 implanting centers.

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Objective: Many methods of minimally invasive surgical harvesting of the great saphenous vein have been developed because of the morbidity related to the long skin incision after traditional (open) great saphenous vein harvesting. One such method involves the use of multiple small incisions separated by 10- to 15-cm skin bridges through which the saphenous vein is harvested. We hypothesized that this method of saphenous vein harvesting might subject the saphenous vein to considerable traction forces, resulting in impaired endothelial cell function.

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