Publications by authors named "Brendan Dougherty"

Nontyphoidal infections are a leading cause of enteric disease in Canada, most commonly associated with foodborne exposures. Raw frozen breaded chicken products (FBCP) have been implicated in 16 outbreaks between 2017 and 2019. This study quantified the impact of the 1 April 2019 requirement by the Canadian Food Inspection Agency (CFIA) for manufacturers to reduce in raw FBCP.

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Inappropriate antibiotic use is a key driver of antibiotic resistance and one that can be mitigated through stewardship. A better understanding of current prescribing practices is needed to develop successful stewardship efforts. This study aims to identify factors that are associated with human cases of enteric illness receiving an antibiotic prescription.

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Spinocerebellar ataxia type 1 (SCA1), a dominantly inherited neurodegenerative disorder caused by an expanded trinucleotide repeat in the gene, is characterized by motor dysfunction, cognitive impairment, and death from compromised swallowing and respiration. To delineate specific cell types that contribute to respiratory dysfunction, we utilized the floxed conditional knock-in mouse. Whole body plethysmography during spontaneous respiration and respiratory challenge showed that mice exhibit a spontaneous respiratory phenotype characterized by elevated respiratory frequency, volumes, and respiratory output.

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In addition to loss of sensory and motor function below the level of the lesion, traumatic spinal cord injury (SCI) may reduce circulating steroid hormones that are necessary for maintaining normal physiological function for extended time periods. For men, who comprise nearly 80% of new SCI cases each year, testosterone is the most abundant circulating sex steroid. SCI often results in significantly reduced testosterone production and may result in chronic low testosterone levels.

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Legionellosis is a disease caused by the bacterium that most commonly presents as Legionnaires' disease (LD), a severe form of pneumonia. From 2015 to 2019, an average of 438 LD cases per year were reported in Canada. However, it is believed that the actual number of cases is much higher, since LD may be underdiagnosed and underreported.

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Acute, intermittent hypoxia (AIH) induces ventilatory long-term facilitation (vLTF) in awake, freely behaving rats under poikilocapnic and isocapnic experimental conditions. Establishing pre-clinical methods for vLTF induction that more closely align with successful protocols in humans and anesthetized rats would minimize dissonance in experimental findings and improve translational aspects of vLTF. Here, we tested several levels of low-dose CO supplementation during and after AIH to determine 1) the lowest amount of inspired CO that would maintain isocapnia in rats during a vLTF protocol, and 2) the net impact of supplemental CO on vLTF expression.

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Objective: Community-engaged learning is used in Master of Public Health programs to enhance student training, connect with communities, help solve societal issues, develop competencies, and build partnerships. However, it is unclear how much community-engaged learning components supplement existing Master of Public Health programs and prepare students in developing these competencies. Thus, the aim of this study was to apply an explanatory mixed-methods study design to evaluate a Canadian Master of Public Health program's community-engaged learning activities and propose recommendations to strengthen public health training and course delivery.

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The aim of this study was to describe the impact of the COVID-19 pandemic on reported cases and clusters of select enteric diseases in Canada, for the period of March 2020 to December 2020. Weekly counts of laboratory confirmed cases of , , Shiga toxin-producing (STEC), and were obtained from laboratory surveillance data. These data were supplemented with epidemiological information on the suspected source of illness, collected for cases identified within whole genome sequencing clusters.

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Circulating sex steroid hormones are critical for neural function and development of neuroplasticity in many regions of the central nervous system. In the spinal cord, our knowledge of steroid hormone influence mostly derives from mechanistic studies of pain processing in dorsal spinal cord circuits; less is known regarding hormonal influence of ventral spinal motor function. Gonadectomy (surgical removal of the testes in males and ovaries in females) rapidly and persistently reduces circulating sex steroids in both females and males, providing a means to interrogate the role of hormones on neural function.

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Nontyphoidal (NTS) is a leading cause of acute gastrointestinal illness in Canada, and reported cases have been on the rise since the early 2000s. To address this trend, agri-food industry partners and government have worked to identify and implement interventions, guided by the enhanced information provided by whole-genome sequencing, to reduce the incidence of NTS. A substantial reduction in the number of NTS cases reported occurred in 2019.

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Background: Non-pharmaceutical interventions (NPIs) aim to reduce the incidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections mostly by limiting contacts between people where virus transmission can occur. However, NPIs limit social interactions and have negative impacts on economic, physical, mental and social well-being. It is, therefore, important to assess the impact of NPIs on reducing the number of coronavirus disease 2019 (COVID-19) cases and hospitalizations to justify their use.

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The long-term dynamics of COVID-19 disease incidence and public health measures may impact individuals' precautionary behaviours as well as support for measures. The objectives of this study were to assess longitudinal changes in precautionary behaviours and support for public health measures. Survey data were collected online from 1030 Canadians in each of 5 cycles in 2020: June 15-July 13; July 22-Aug 8; Sept 7-15; Oct 14-21; and Nov 12-17.

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Background: Members of the bacterial genus cause salmonellosis, a disease with a spectrum of clinical presentations from a self-limiting gastroenteritis to more severe bacteremia, organ failure and sepsis. The genus consists of over 2,600 serological variants (serovars). Important differences in the pathogenesis of serovars have been noted.

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New Findings: What is the central question of this study? Would ovariectomy cause prolonged changes in ventilation and sustained loss of acute, intermittent hypoxia-induced neuroplasticity or would these outcomes be restored with time? What is the main finding and its importance? Our main findings demonstrate that ovariectomy elicits minimal alteration in overall breathing function but impairs acute, intermittent hypoxia-induced plasticity for ≤ 12 weeks.

Abstract: Sex hormones are necessary to enable respiratory neuroplasticity, including phrenic long-term facilitation (pLTF), a form of respiratory motor plasticity elicited by acute, intermittent hypoxia (AIH). Female rats exhibit a progressive increase in phrenic nerve amplitude after AIH characteristic of pLTF only during pro-oestrus, the stage of the oestrous cycle notable for elevated circulating oestradiol levels.

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Pulmonary carcinoid tumours are a rare form of malignancy that often present with clinical heterogeneity and are challenging to diagnose. Diagnosis during pregnancy is further complicated by delays in imaging and procedures to minimise harm to the fetus. This case describes a primigravid healthcare worker who was diagnosed with pulmonary carcinoid in her first trimester of pregnancy, with particular focus on the unique radiological findings of subpleural blebs as a feature.

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Female carriers of Duchenne muscular dystrophy (DMD) presenting with DMD symptomology similar to males with DMD, such as skeletal muscle weakness and cardiomyopathy, are termed manifesting carriers. There is phenotypic variability among manifesting carriers including the age of onset, which can range from the first to fourth decade of life. In females, estrogen levels typically begin to decline during the fourth decade of life and estrogen deficiency contributes to loss of muscle strength and recovery of strength following injury.

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Introduction: This is a phase 1, open-label, single-centre, uncontrolled, dose-escalation study to evaluate the feasibility, tolerability and pharmacokinetic profiles of a single dose of liposomal curcumin, administered via an existing tunnelled indwelling pleural catheter (TIPC) directly to the tumour site in individuals with diagnoses of malignant pleural effusion. Primarily, we aim to determine a maximum tolerated dose of liposomal curcumin administered via this method.

Methods And Analysis: We will use a 3+3 expanded cohort for predefined dose-escalation levels or until a predefined number of dose-limiting toxicities are reached.

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While surveillance can identify changes in COVID-19 transmission patterns over time and space, sections of the population at risk, and the efficacy of public health measures, reported cases of COVID-19 are generally understood to only capture a subset of the actual number of cases. Our primary objective was to estimate the percentage of cases reported in the general community, considered as those that occurred outside of long-term care facilities (LTCFs), in specific provinces and Canada as a whole. We applied a methodology using the delay-adjusted case fatality ratio (CFR) to all cases and deaths, as well as those representing the general community.

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Background: Pleural effusions remain a common medical problem which often requires diagnostic pleurocentesis to determine the underlying cause. Pleurocentesis is a frequently performed procedure worldwide with improved safety using ultrasound (US) technology.

Objectives: This prospective, single-center study evaluated the use of an ultraportable handheld (UPHH) US compared with standard point-of-care (SPOC) US in determining a safe site for pleurocentesis.

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Objectives: Understanding the current state of antibiotic treatment guidelines and prescribing practices for bacterial enteric infections is critical to inform antibiotic stewardship initiatives. This study aims to add to the current understanding through three objectives: (i) to identify and summarize published treatment guidelines for bacterial enteric infections; (ii) to describe observed antibiotic prescribing practices for bacterial enteric infections across three sentinel sites in Canada; and (iii) to assess concordance between observed antibiotic prescribing and treatment guidelines.

Methods: An environmental scan of treatment guidelines for bacterial enteric infections was conducted and recommendations were collated.

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Ventilatory long-term facilitation (vLTF) is a form of respiratory plasticity characterized by a progressive and sustained increase in minute ventilation over time following acute, intermittent hypoxia (AIH). Though vLTF has been repeatedly demonstrated in adult males (rats and humans), few studies have assessed vLTF in adult females and no studies have explored differential expression of vLTF across the normal female estrous cycle. We recently reported that AIH-induced plasticity of phrenic motor output (phrenic long-term facilitation, pLTF), a phenotypically similar form of respiratory plasticity presenting as a sustained increase in phrenic nerve amplitude, develops in adult female rats only during the proestrus stage of the estrous cycle, notable for high levels of serum estrogen.

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Objective: In lung cancer screening practice low-dose computed tomography, diameter, and volumetric measurement have been used in the management of screen-detected lung nodules. The aim of this study was to compare the performance of nodule malignancy risk prediction tools using diameter or volume and between computer-aided detection (CAD) and radiologist measurements.

Methods: Multivariable logistic regression models were prepared by using data from two multicenter lung cancer screening trials.

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Although inflammation is prevalent in many clinical disorders challenging breathing, we are only beginning to understand the impact of inflammation on neural mechanisms of respiratory control. We recently demonstrated one form of respiratory motor plasticity is extremely sensitive to even mild inflammation induced by a single night (8 h) of intermittent hypoxia (IH-1), mimicking aspects of obstructive sleep apnea. Specifically, phrenic long-term facilitation (pLTF) following moderate acute intermittent hypoxia (AIH) is abolished by IH-1, but restored by high doses of the non-steroidal anti-inflammatory drug, ketoprofen.

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Gonadal steroids modulate CNS plasticity, including phrenic long-term facilitation (pLTF), a form of spinal respiratory neuroplasticity resulting in increased phrenic nerve motor output following exposure to acute intermittent hypoxia (aIH; three 5 min episodes, 10.5% O). Despite the importance of respiratory system neuroplasticity, and its dependence on estrogen in males, little is known about pLTF expression or mechanisms of estrogen signaling in females.

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