Inter-Rater and Intra-Rater Agreement in Scoring Severity of Rodent Cardiomyopathy and Relation to Artificial Intelligence-Based Scoring.

We previously developed a computer-assisted image analysis algorithm to detect and quantify the microscopic features of rodent progressive cardiomyopathy (PCM) in rat heart histologic sections and validated the results with a panel of five veterinary toxicologic pathologists using a multinomial logistic model. In this study, we assessed both the inter-rater and intra-rater agreement of the pathologists and compared pathologists' ratings to the artificial intelligence (AI)-predicted scores. Pathologists and the AI algorithm were presented with 500 slides of rodent heart.

Scientific and Regulatory Policy Committee Points to Consider: Review of the United States Food and Drug Administration (FDA) Guidance on Pathology Peer Review in Nonclinical Toxicology Studies.

In December 2021, the United States Food and Drug Administration (FDA) issued the final guidance for industry titled . The stated purpose of the FDA guidance is to provide information to sponsors, applicants, and nonclinical laboratory personnel regarding the management and conduct of histopathology peer review as part of nonclinical toxicology studies conducted in compliance with good laboratory practice (GLP) regulations. On behalf of and in collaboration with global societies of toxicologic pathology and the Society of Quality Assurance, the Scientific and Regulatory Policy Committee (SRPC) of the Society of Toxicologic Pathology (STP) initiated a review of this FDA guidance.

Case-area targeted interventions during a large-scale cholera epidemic: A prospective cohort study in Northeast Nigeria.

Background: Cholera outbreaks are on the rise globally, with conflict-affected settings particularly at risk. Case-area targeted interventions (CATIs), a strategy whereby teams provide a package of interventions to case and neighboring households within a predefined "ring," are increasingly employed in cholera responses. However, evidence on their ability to attenuate incidence is limited.

Using Wash'Em to Design Handwashing Programmes for Crisis-Affected Populations in Zimbabwe: A Process Evaluation.

Wash'Em is a process that supports humanitarians in assessing and designing rapid but context-specific hygiene programmes in crises or outbreaks. The process consists of training implementers, using tools to learn from populations, and entering findings into a software which generates contextualised activities. A process evaluation of Wash'Em use was conducted in a drought-affected area in Midland province, Zimbabwe.

Mapping the association between mental health and people's perceived and actual ability to practice hygiene-related behaviours in humanitarian and pandemic crises: A scoping review.

Humanitarian crises such as disease outbreaks, conflict and displacement and natural disasters affect millions of people primarily in low- and middle-income countries. Here, they often reside in areas with poor environmental health conditions leading to an increased burden of infectious diseases such as gastrointestinal and respiratory infections. Water, sanitation, and hygiene behaviours are critical to prevent such infections and deaths.

How are hygiene programmes designed in crises? Qualitative interviews with humanitarians in the Democratic Republic of the Congo and Iraq.

Background: Hygiene behaviour change programmes are complex to design. These challenges are heightened during crises when humanitarian responders are under pressure to implement programmes rapidly despite having limited information about the local situation, behaviours and opinions-all of which may also be rapidly evolving.

Methods: We conducted in-depth interviews with 36 humanitarian staff involved in hygiene programme design in two crisis-affected settings-one a conflict affected setting (Iraq) and the other amid a cholera outbreak (Democratic Republic of the Congo).

How does handwashing behaviour change in response to a cholera outbreak? A qualitative case study in the Democratic Republic of the Congo.

Background: Handwashing with soap has the potential to curb cholera transmission. This research explores how populations experienced and responded to the 2017 cholera outbreak in the Democratic Republic of the Congo and how this affected their handwashing behaviour.

Methods: Cholera cases were identified through local cholera treatment centre records.

How is hygiene behaviour affected by conflict and displacement? A qualitative case study in Northern Iraq.

This research aimed to qualitatively explore whether the determinants of handwashing behaviour change according to the duration of displacement or the type of setting that people are displaced to. We conducted an exploratory qualitative study in three different post-conflict settings in Northern Iraq-a long-term displacement camp, a short-term displacement camp, and villages where people were returning to post the conflict. We identified 33 determinants of handwashing in these settings and, of these, 21 appeared to be altered by the conflict and displacement.

An exploratory pilot study of the effect of modified hygiene kits on handwashing with soap among internally displaced persons in Ethiopia.

Background: Internally displaced persons fleeing their homes due to conflict and drought are particularly at risk of morbidity and mortality from diarrhoeal diseases. Regular handwashing with soap (HWWS) could substantially reduce the risk of these infections, but the behaviour is challenging to practice while living in resource-poor, informal settlements. To mitigate these challenges, humanitarian aid organisations distribute hygiene kits, including soap and handwashing infrastructure.

Using Artificial Intelligence to Detect, Classify, and Objectively Score Severity of Rodent Cardiomyopathy.

Rodent progressive cardiomyopathy (PCM) encompasses a constellation of microscopic findings commonly seen as a spontaneous background change in rat and mouse hearts. Primary histologic features of PCM include varying degrees of cardiomyocyte degeneration/necrosis, mononuclear cell infiltration, and fibrosis. Mineralization can also occur.

A Diagnostic Approach for Rodent Progressive Cardiomyopathy and Like Lesions in Toxicology Studies up to 28 Days in the Sprague Dawley Rat (Part 2 of 2).

To test the diagnostic approach described in part 1 of this article, 2 exercises were completed by pathologists from multiple companies/agencies. Pathologist's examination of whole slide image (WSI) heart sections from rats using personal diagnostic approaches (exercise #1) corroborated conclusions from study #1. Using the diagnostic approach described in part 1, these pathologists examined the same WSI heart sections (exercise #2) to determine whether that approach increased consistency of diagnosis of rodent progressive cardiomyopathy (PCM) lesions.

A Diagnostic Approach for Rodent Progressive Cardiomyopathy and Like Lesions in Toxicology Studies up to 28 Days in the Sprague Dawley Rat (Part 1 of 2).

Spontaneous rodent progressive cardiomyopathy (PCM) in the Sprague Dawley rat may confound identification and/or interpretation of potential test article (TA)-related cardiotoxicity. Pathologists apply diagnostic term(s) and thresholds for diagnosing and assigning severity grades for PCM and/or PCM-like (PCM/like) lesions consistently within a study, which is necessary to identify and interpret TA-related findings. Due to differences in training and/or experiences, diagnostic terms and thresholds may vary between pathologists.

Evaluation of von Willebrand factor and von Willebrand factor propeptide in models of vascular endothelial cell activation, perturbation, and/or injury.

Pharmacologically, vasoactive agents targeting endothelial and/or smooth muscle cells (SMC) are known to cause acute drug-induced vascular injury (DIVI) and the resulting pathology is due to endothelial cell (EC) perturbation, activation, and/or injury. Alteration in EC structure and/or function may be a critical event in vascular injury and, therefore, evaluation of the circulatory kinetic profile and secretory pattern of EC-specific proteins such as VWF and VWFpp could serve as acute vascular injury biomarkers. In rat and dog models of DIVI, this profile was determined using pharmacologically diverse agents associated with functional stimulation/perturbation (DDAVP), pathological activation (lipopolysaccharide [LPS]/endotoxin), and structural damage (fenoldopam [FD], dopamine [DA], and potassium channel opener (PCO) ZD6169).

Spontaneous cardiomyopathy in young Sprague-Dawley rats: evaluation of biological and environmental variability.

Cardiovascular safety signals in nonclinical studies remain among the main reasons for drug attrition during pharmaceutical research and development. Drug-induced changes can be functional and/or associated with morphological alterations in the normal heart histology. It is therefore crucial to understand the normal variations in histology to discriminate test article-related changes from background lesions.

MicroRNA changes in rat mesentery and serum associated with drug-induced vascular injury.

Regulatory miRNAs play a role in vascular biology and are involved in biochemical and molecular pathways dysregulated during vascular injury. Collection and integration of functional miRNA data into these pathways can provide insight into pathogenesis at the site of injury; the same technologies applied to biofluids may provide diagnostic or surrogate biomarkers. miRNA was analyzed from mesentery and serum from rats given vasculotoxic compounds for 4 days.

Potential candidate genomic biomarkers of drug induced vascular injury in the rat.

Drug-induced vascular injury is frequently observed in rats but the relevance and translation to humans present a hurdle for drug development. Numerous structurally diverse pharmacologic agents have been shown to induce mesenteric arterial medial necrosis in rats, but no consistent biomarkers have been identified. To address this need, a novel strategy was developed in rats to identify genes associated with the development of drug-induced mesenteric arterial medial necrosis.

Spontaneous findings in the heart of Mauritian-origin cynomolgus macaques (Macaca fascicularis).

The cynomolgus macaque is the most commonly used nonhuman primate in nonclinical toxicity testing, but the impact of the geographic source of cynomolgus macaque on differences in spontaneous pathology and response to xenobiotics has only recently been explored. Previous work from the authors' facility has described spontaneous cardiac findings in predominantly Indonesian-source animals; however, the authors have recently observed a novel spectrum of cardiac findings in Mauritian-source animals. This review evaluated the spontaneous macroscopic and microscopic cardiac findings in vehicle control Mauritian-source macaques used for routine toxicity testing.

Detection and characterization of circulating endothelial progenitor cells in normal rat blood.

Introduction: There are currently few widely accepted noninvasive detection methods for drug-induced vascular damage. Circulating endothelial progenitor cell (EPC) enumeration in humans has recently gained attention as a potential biomarker of vascular injury/endothelial damage/dysfunction. The rat is commonly used in preclinical drug development toxicity testing and lacks consensus noninvasive methodologies for immunophenotypic identification of EPCs.

Protein extraction of formalin-fixed, paraffin-embedded tissue enables robust proteomic profiles by mass spectrometry.

Global mass spectrometry (MS) profiling and spectral count quantitation are used to identify unique or differentially expressed proteins and can help identify potential biomarkers. MS has rarely been conducted in retrospective studies, because historically, available samples for protein analyses were limited to formalin-fixed, paraffin-embedded (FFPE) archived tissue specimens. Reliable methods for obtaining proteomic profiles from FFPE samples are needed.

Systemic activation of the transient receptor potential vanilloid subtype 4 channel causes endothelial failure and circulatory collapse: Part 2.

The transient receptor potential (TRP) vanilloid subtype 4 (V4) is a nonselective cation channel that exhibits polymodal activation and is expressed in the endothelium, where it contributes to intracellular Ca2+ homeostasis and regulation of cell volume. The purpose of the present study was to evaluate the systemic cardiovascular effects of GSK1016790A, a novel TRPV4 activator, and to examine its mechanism of action. In three species (mouse, rat, and dog), the i.

Transcriptional profiling of laser capture microdissected rat arterial elements: fenoldopam-induced vascular toxicity as a model system.

Transcriptional profiling of specific elements of vasculature from animal models of vascular toxicity is an approach to gain insight into molecular mechanisms of vascular injury. Feasibility of using laser capture microdissection (LCM) to evaluate differential gene expression in selected elements of mesenteric arteries (MA) from untreated rats and rats given a single vasotoxic dose of 100 mg/kg Fenoldopam and euthanized 1 or 4 hours postdose was assessed. Regions of MA (endothelial cells [EC] and vascular smooth muscle cells [VSMC]) were selectively microdissected from optimal-cutting-temperature (O.

Evaluation of the cynomolgus monkey stomach: recommendations for standard sampling procedures in nonclinical safety studies.

The cynomolgus macaque is the most commonly used nonhuman primate in nonclinical toxicity testing, but the macroscopic and microscopic anatomy of the stomach in the cynomolgus macaque is poorly described. To develop a reliable sampling method for histologic evaluation of the cynomolgus macaque stomach in regulatory toxicity studies, the stomachs of control animals were prospectively evaluated using an extensive sectioning pattern. The stomach of the cynomolgus macaque differs from that described for the human stomach and has a prominent fundus that lacks parietal cells.

Role of p38 in regulation of hematopoiesis: effect of p38 inhibition on cytokine production and transcription factor activity in human bone marrow stromal cells.

This study was designed to evaluate effects of specific p38 MAP kinase inhibition on gene and protein expression of essential hematopoietic cytokines in primary human bone marrow stromal cells (HBMSC) and to identify downstream transcription factors (TF) regulated by the p38 MAP kinase signalling pathway. In vitro effects of p38 inhibitors (p38i) on cytokine regulation were compared to inhibitors of other major signalling pathways including PI3 kinase, JNK, MEK-1, NF-kappaB or protein kinase C (PKC). HBMSC were pre-treated with p38i (SB-203580) for 1 h and then stimulated with 200 ng/ml lipopolysaccharide (LPS).

Confounding effects of platelets on flow cytometric analysis and cell-sorting experiments using blood-derived cells.

Background: Flow cytometric analysis and cell-sorting of peripheral blood leukocytes is commonplace; however, platelet contamination is typically ignored during immunophenotypic analysis and sorting of blood-derived cells.

Methods: Red blood cells, platelets, T & B lymphocytes, monocytes, and granulocytes were sorted from rat blood preparations. Presort enrichment was performed by differential centrifugation for all cell types.