2023 International Academy of Toxicologic Pathology (IATP) Satellite Symposium: "Medical Device Safety Assessment: Pathology and Toxicology Perspective".

Medical devices represent a complex category of medicinal products with varying definitions depending on the regional jurisdiction of regulatory agencies. A common aspect of these definitions is that a medical device is intended to be used for specific medicinal purpose where the primary intended action of the device is not achieved through pharmacologic (or other chemical) means. While regional regulatory frameworks for medical devices are different than for pharmaceutical or biological products, medical device manufacturers are required to evaluate the safety and performance of these products in the context of their intended use.

Encapsulating therapeutic cells in RGD-modified agarose microcapsules.

Current cell-based strategies for repairing damaged tissue often show limited efficacy due to low cell retention at the site of injury. Encapsulation of cells within hydrogel microcapsules demonstrably increases cell retention but benefits can be limited due to premature cell escape from the hydrogel microcapsules and subsequent clearance from the targeted tissue. We propose a method of encapsulating cells in agarose microcapsules that have been modified to increase cell retention by providing cell attachment domains within the agarose hydrogel allowing cells to adhere to the microcapsules.

Updating the Standards of Professional Competence in the Field of Toxicology: The Second Generation of Best Practice.

The American Board of Toxicology (ABT), in consultation with ACT Credentialing & Career Services (ACT), performed a practice analysis study of general toxicology in 2020-21. This work follows up on an initial practice analysis commissioned by the ABT and conducted in 2014-2015, results of which were published in 2016. The purpose of the current, second-generation study was to update and validate the existing process-based delineation of practice of general toxicologists, including major domains of responsibility and tasks performed in practice.

Best practices in prenatal health promotion: Perceptions, experiences, and recommendations of Ottawa, Canada, prenatal key informants.

Background: Prenatal health promotion includes the provision of evidence-based information and practical skills to optimize maternal-fetal outcomes. Increasingly, prenatal education is delivered by both healthcare professionals and allied childbirth educators, in community- or hospital-based group classes, targeted outreach programs, and online modules.

Objectives: To better understand how prenatal health promotion relates to a diverse urban community, we assessed the perspectives of Ottawa, Canada prenatal key informants.

A case study: Re-evaluating the biological risk following a processing aid change on a marketed cardiovascular implant device.

Per ISO 10993-1:2018, a processing change to a medical device requires re-evaluation of biological risk. Here, we present the biological evaluation of a marketed cardiovascular implant following a detergent formulation change. This change was initially assessed through a qualitative toxicological risk assessment based on the fully disclosed detergent formulation and a limited panel of biological testing.

Ottawa prenatal educator e-survey: Experiences and perceptions of public health nurses and allied childbirth educators.

Background: Prenatal education provides opportunities for health promotion of healthy behaviors and risk reduction. Quality and coherence with prenatal health promotion best practices depend on an individual class instructor. The objective of our study was to document the experiences, practices, and perceptions of our diverse Ottawa, Canada community of prenatal educators.

Deterministic paracrine repair of injured myocardium using microfluidic-based cocooning of heart explant-derived cells.

While encapsulation of cells within protective nanoporous gel cocoons increases cell retention and pro-survival integrin signaling, the influence of cocoon size and intra-capsular cell-cell interactions on therapeutic repair are unknown. Here, we employ a microfluidic platform to dissect the impact of cocoon size and intracapsular cell number on the regenerative potential of transplanted heart explant-derived cells. Deterministic increases in cocoon size boosted the proportion of multicellular aggregates within cocoons, reduced vascular clearance of transplanted cells and enhanced stimulation of endogenous repair.

Rapid fingerprinting of spilled petroleum products using fluorescence spectroscopy coupled with parallel factor and principal component analysis.

The characterization of spilled petroleum products in an oil spill is necessary for identifying the spill source, selection of clean-up strategies, and evaluating potential environmental and ecological impacts. Existing standard methods for the chemical characterization of spilled oils are time-consuming due to the lengthy sample preparation for analysis. The main objective of this study is the development of a rapid screening method for the fingerprinting of spilled petroleum products using excitation/emission matrix (EEM) fluorescence spectroscopy, thereby delivering a preliminary evaluation of the petroleum products within hours after a spill.

Patient Needs, Required Level of Care, and Reasons Delaying Hospital Discharge for Nonacute Patients Occupying Acute Hospital Beds.

This study aims to determine the proportion of nonacute patients occupying acute care beds and to describe their needs, the appropriate level of alternative care, and reasons preventing discharge. Data from 952 patients hospitalized in an acute care unit for 30 days were obtained from their medical charts and by consulting with the medical team at two tertiary teaching hospitals. Among them, 333 (35%) were determined nonacute on day 30 of hospitalization.

Bubble-Facilitated VOC Transport from LNAPL Smear Zones and Its Potential Effect on Vapor Intrusion.

Most conceptual and mathematical models of soil vapor intrusion assume that the transport of volatile organic compounds (VOCs) from a source toward a building is limited by diffusion through the soil gas. Under conditions where advection occurs, transport rates are higher and can lead to higher indoor air concentrations. Advection-dominated conditions can be created by gas bubble flow in the saturated zone.

Characteristics and Needs of Psychiatric Patients With Prolonged Hospital Stay.

Objective: To describe the characteristics and needs prior to, on admission, during the first month in hospital, at the thirtieth day of hospitalization and posthospital discharge of psychiatric patients occupying acute beds.

Methods: This prospective observational study was conducted in 2 tertiary care hospitals. Adult patients hospitalized on a psychiatric unit for 30 days were identified.

Hospital stay on acute care units for non-acute reasons: Effects of patient pre-hospitalization and admission factors.

This study identifies patient risk factors present prior to an acute hospitalization that are associated with occupying acute care beds for non-acute reasons on the 30 day of a hospitalization. Data from 952 adult patients were obtained, among which 333 (35%) were evaluated as non-acute on their 30 day. Inability to move in and out of the bed, cognitive impairment, receiving home or community healthcare services prior to hospitalization, unavailable family resources, a secondary diagnosis within the mental and behavioural category, and age ≥75 years were found to increase the risk of occupying acute care beds for non-acute reasons, while patients with a feeding tube were less likely to be non-acute at day 30.

Detection and correction of prescription errors by an emergency department pharmacy service.

Objectives: Emergency departments (EDs) are recognized as a high-risk setting for prescription errors. Pharmacist involvement may be important in reviewing prescriptions to identify and correct errors. The objectives of this study were to describe the frequency and type of prescription errors detected by pharmacists in EDs, determine the proportion of errors that could be corrected, and identify factors associated with prescription errors.

Patient considerations in the management of multiple sclerosis: development and clinical utility of oral agents.

Multiple sclerosis (MS) is one of the most frequently occurring disabling neurological disorders among young adults in Canada. It is a chronic inflammatory disorder of the central nervous system (CNS) that is thought to be immune mediated in nature. An estimated 55,000-75,000 Canadians suffer from this debilitating disease.

Strut tissue coverage and endothelial cell coverage: a comparison between bare metal stent platforms and platinum chromium stents with and without everolimus-eluting coating.

Aims: In a rabbit denudation model, assess impact of strut thickness on arterial healing by comparing endothelial cell coverage and strut tissue coverage after implantation of bare metal stents of varying thickness; evaluate the effect of an everolimus-eluting stent.

Methods And Results: Strut tissue coverage and endothelialisation were assessed 14 and 21 days after implantation with scanning electron microscopy quantitation methods and immunostaining against the endothelial cell marker PECAM-1 (CD-31). At 14 days, strut tissue coverage was higher with the stainless steel Liberté stent (88%, 97 µm) versus Express (77%, 132 µm).

Development of the Canadian Emergency Department Diagnosis Shortlist.

Objective: Managers of emergency departments (EDs), governments and researchers would benefit from reliable data sets that characterize use of EDs. Although Canadian ED lists for chief complaints and triage acuity exist, no such list exists for diagnosis classification. This study was aimed at developing a standardized Canadian Emergency Department Diagnosis Shortlist (CED-DxS), as a subset of the full International Classification of Diseases, 10th revision, with Canadian Enhancement (ICD-10-CA).

Markers of overcrowding in a pediatric emergency department.

Objectives: The objective of this study was to identify markers of overcrowding in pediatric emergency departments (PEDs) according to expert opinion and then to use statistical methods to further explore the underlying construct of overcrowding.

Methods: A cross-sectional survey of all PED directors (n = 12) and pediatric emergency medicine fellowship program directors (n = 10) across Canada was conducted to elicit expert opinion on relevant markers of emergency department (ED) crowding. The list of markers was reduced to those specific to the ED for which data could be extracted from one tertiary care PED from an existing computerized patient tracking system.

Evaluation of a dry format reagent alternative for CD4 T-cell enumeration for the FACSCount system: a report on a Moroccan-Canadian study.

Background: Efforts to improve alternative CD4 T-cell counting methods are critical to accelerate the implementation of HIV antiretroviral therapy in resources limited regions. Substituting liquid format reagents to eliminate cold-chain transportation and refrigerated storage with dry format reagents contributes to higher efficiency supply management solution especially for laboratories at remote locations. ReaMetrix has developed dry format reagent kits compatible with the FACSCount system, a dedicated flow cytometer for T-cell subset enumeration widely used in resource limited settings.

QASI, an international quality management system for CD4 T-cell enumeration focused to make a global difference.

Background: A significant worldwide mobilization effort to treat people with HIV disease began in 2003. Most guidelines for initiating antiretroviral therapy require reliable and reproducible CD4 T-cell counting. Therefore, any effort that improves global availability of quality managed assessment schemes for CD4 T-cell enumeration is a positive achievement for the clinical management of AIDS on a worldwide scale.

Symptom-to-door time in ST segment elevation myocardial infarction: overemphasized or overlooked? Results from the AMI-McGill study.

Background: Ischemic time is a major determinant of infarct size in ST segment elevation myocardial infarction (STEMI). Emphasis is placed on reducing the door-to-reperfusion therapy time component, whereas the symptom-to-door time is often overlooked.

Objectives: To correlate the symptom-to-door time with left ventricular ejection fraction (LVEF) in patients with STEMI.

Basal gene expression in male and female Sprague-Dawley rat nasal respiratory and olfactory epithelium.

The nasal epithelium is an important target site for chemically induced toxicity and carcinogenicity. Experimental studies show that site-specific lesions can arise within the nasal respiratory or olfactory epithelium following the inhalation of certain chemicals. Moreover, gender differences in epithelial response are also reported.

Impact of a standardized communication system on continuity of care between family physicians and the emergency department.

Objective: It has been suggested that continuity of care is hampered because of the lack of communication between emergency departments (EDs) and primary care providers. A web-based, standardized communication system (SCS) that enables family physicians (FPs) to visualize information regarding their patients' ED visits was developed. This paper aims to evaluate the impact of this SCS on continuity of care.

Arsenic stimulates sinusoidal endothelial cell capillarization and vessel remodeling in mouse liver.

Unlabelled: Trivalent arsenic [As(III)] is a well-known environmental toxicant that causes a wide range of organ-specific diseases and cancers. In the human liver, As(III) promotes vascular remodeling, portal fibrosis, and hypertension, but the pathogenesis of these As(III)-induced vascular changes is unknown. To investigate the hypothesis that As(III) targets the hepatic endothelium to initiate pathogenic change, mice were exposed to 0 or 250 parts per billion (ppb) of As(III) in their drinking water for 5 weeks.

Low level arsenic promotes progressive inflammatory angiogenesis and liver blood vessel remodeling in mice.

The vascular effects of arsenic in drinking water are global health concerns contributing to human disease worldwide. Arsenic targets the endothelial cells lining blood vessels, and endothelial cell activation or dysfunction may underlie the pathogenesis of both arsenic-induced vascular diseases and arsenic-enhanced tumorigenesis. The purpose of the current studies was to demonstrate that exposing mice to drinking water containing environmentally relevant levels of arsenic promoted endothelial cell dysfunction and pathologic vascular remodeling.