GEMpath Inc.

Longmont, CO, United States

GEMpath Inc.

Longmont, CO, United States
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Cardiff R.D.,University of California at Davis | Couto S.,Genentech | Bolon B.,GEMpath Inc.
Breast Cancer Research | Year: 2011

Recent efforts to understand breast cancer biology involve three interrelated themes that are founded on a combination of clinical and experimental observations. The central concept is gene addiction. The clinical dilemma is the escape from gene addiction, which is mediated, in part, by phenotypic plasticity as exemplified by epithelial-to-mesenchymal transition and mesenchymal-to-epithelial transition. Finally, cancer stem cells are now recognized as the basis for minimal residual disease and malignant progression over time. These themes cooperate in breast cancer, as induction of epithelial-to-mesenchymal transition enhances self-renewal and expression of cancer stem cells, which are believed to facilitate tumor resistance. © 2011 BioMed Central Ltd.

PubMed | The Research Institute at Nationwide Childrens Hospital, Ohio State University, GEMPath Inc., State University of New York at Buffalo and Le Bonheur Childrens Hospital
Type: Journal Article | Journal: American journal of physiology. Renal physiology | Year: 2016

Acquired renal scarring occurs in a subset of patients following febrile urinary tract infections and is associated with hypertension, proteinuria, and chronic kidney disease. Limited knowledge of histopathology, immune cell recruitment, and gene expression changes during pyelonephritis restricts the development of therapies to limit renal scarring. Here, we address this knowledge gap using immunocompetent mice with vesicoureteral reflux. Transurethral inoculation of uropathogenic Escherichia coli in C3H/HeOuJ mice leads to renal mucosal injury, tubulointerstitial nephritis, and cortical fibrosis. The extent of fibrosis correlates most significantly with inflammation at 7 and 28 days postinfection. The recruitment of neutrophils and inflammatory macrophages to infected kidneys is proportional to renal bacterial burden. Transcriptome analysis reveals molecular signatures associated with renal ischemia-reperfusion injury, immune cell chemotaxis, and leukocyte activation. This murine model recapitulates the cardinal histopathological features observed in humans with acquired renal scarring following pyelonephritis. The integration of histopathology, quantification of cellular immune influx, and unbiased transcriptional profiling begins to define potential mechanisms of tissue injury during pyelonephritis in the context of an intact immune response. The clear relationship between inflammatory cell recruitment and fibrosis supports the hypothesis that acquired renal scarring arises as a consequence of excessive host inflammation and suggests that immunomodulatory therapies should be investigated to reduce renal scarring in patients with pyelonephritis.

PubMed | Bolder BioPath Inc., Lilly Research Laboratories, WB High Preclin Path Tox Consulting LLC, GEMpath Inc. and 9 more.
Type: Journal Article | Journal: Journal of toxicologic pathology | Year: 2016

The INHAND (International Harmonization of Nomenclature and Diagnostic Criteria for Lesions in Rats and Mice) Project ( is an initiative of the Societies of Toxicological Pathology from Europe (ESTP), Great Britain (BSTP), Japan (JSTP) and North America (STP) to develop an internationally accepted nomenclature for proliferative and nonproliferative lesions in laboratory animals. The purpose of this publication is to provide a standardized nomenclature for classifying microscopic lesions observed in the skeletal tissues and teeth of laboratory rats and mice, with color photomicrographs illustrating examples of many common lesions. The standardized nomenclature presented in this document is also available on the internet ( Sources of material were databases from government, academic and industrial laboratories throughout the world.

PubMed | College Park, Stratoxon LLC, GEMpath Inc., Pfizer and 3 more.
Type: Journal Article | Journal: Toxicologic pathology | Year: 2016

Recommendations (best practices) are provided by the Society of Toxicologic Pathologys Adversity Working Group for making consistent interpretations of test article-related effects as adverse and assigning a no observed adverse effect level (NOAEL) in nonclinical toxicity studies. Adverse is a term indicating harm to the test animal, while nonadverse indicates lack of harm. Adverse findings in the study reports should be defined in relation to effects on the test species used and within the context of the given study. Test article-related effects should be described on their own merits, and decisions to consider them as adverse or nonadverse should be justified. Related effects may be discussed together; in particular, markers of toxicity that are not in and of themselves adverse ideally should be discussed in conjunction with the causal toxicity to determine adversity. Adverse findings should be identified in subreports (clinical data, pathology data, etc.) if sufficient information is available, and/or in the final study report as individual or grouped findings, but study NOAELs should be established at the level of the overall study report. Interpretations such as not biologically relevant or not toxicologically important should be avoided unless defined and supported by scientific rationale. Decisions defining adverse findings and the NOAEL in final study reports should combine the expertise of all contributing scientific disciplines. Where possible, use of NOAELs in data tables should be linked to explanatory text that places them in context. Ideally, in nonclinical summary documents, NOAELs from multiple studies are considered together in defining the most important adverse responses in the most sensitive species. These responses are then considered along with an understanding of their likely mechanisms, as well as other information such as variability in species sensitivity, comparative pathology, reversibility and progression, kinetics, and metabolism of the test substance to help assess human risk.

Scudamore C.L.,Mary Lyon Center | Soilleux E.J.,University of Oxford | Karp N.A.,Wellcome Trust Sanger Institute | Smith K.,Royal Veterinary College | And 9 more authors.
Journal of Pathology | Year: 2016

Animal models are essential research tools in modern biomedical research, but there are concerns about their lack of reproducibility and the failure of animal data to translate into advances in human medical therapy. A major factor in improving experimental reproducibility is thorough communication of research methodologies. The recently published ARRIVE guidelines outline basic information that should be provided when reporting animal studies. This paper builds on ARRIVE by providing the minimum information needed in reports to allow proper assessment of pathology data gathered from animal tissues. This guidance covers aspects of experimental design, technical procedures, data gathering, analysis, and presentation that are potential sources of variation when creating morphological, immunohistochemical (IHC) or in situ hybridization (ISH) datasets. This reporting framework will maximize the likelihood that pathology data derived from animal experiments can be reproduced by ensuring that sufficient information is available to allow for replication of the methods and facilitate inter-study comparison by identifying potential interpretative confounders. © 2015 Pathological Society of Great Britain and Ireland.

PubMed | Merck KGaA, Exponent, Inc., Consultants in Veterinary Pathology Inc., University of Montréal and GEMpath Inc.
Type: Journal Article | Journal: Toxicologic pathology | Year: 2016

Neuropathology methods in rodent developmental neurotoxicity (DNT) studies have evolved with experience and changing regulatory guidance. This article emphasizes principles and methods to promote more standardized DNT neuropathology evaluation, particularly procurement of highly homologous brain sections and collection of the most reproducible morphometric measurements. To minimize bias, brains from all animals at all dose levels should be processed from brain weighing through paraffin embedding at one time using a counterbalanced design. Morphometric measurements should be anchored by distinct neuroanatomic landmarks that can be identified reliably on the faced block or in unstained sections and which address the region-specific circuitry of the measured area. Common test article-related qualitative changes in the developing brain include abnormal cell numbers (yielding altered regional size), displaced cells (ectopia and heterotopia), and/or aberrant differentiation (indicated by defective myelination or synaptogenesis), but rarely glial or inflammatory reactions. Inclusion of digital images in the DNT pathology raw data provides confidence that the quantitative analysis was done on anatomically matched (i.e., highly homologous) sections. Interpreting DNT neuropathology data and their presumptive correlation with neurobehavioral data requires an integrative weight-of-evidence approach including consideration of maternal toxicity, body weight, brain weight, and the pattern of findings across brain regions, doses, sexes, and ages.

Dr. Peter S. Spencer, a pioneering neurotoxicologist of international renown, delivered the keynote address at the 2010 Joint Scientific Symposium of the Society of Toxicologic Pathology (STP) and the International Federation of Societies of Toxicologic Pathologists (IFSTP). He has made many landmark discoveries during his four-decade career. Dr. Spencer's address communicated several fundamental principles of past and present toxicologic neuropathology research, and he also predicted future trends in the field. First, classic approaches to toxicologic neuropathology emphasized morphologic techniques such as light microscopic and ultrastructural assessment. However, neuropathology methods alone rarely reveal the mechanism(s) and etiology of neurotoxic conditions, so neurotoxicity problems are now being investigated using a multidisciplinary approach in which neuropathologic assessment is but one component of the analysis. The two primary trends for future toxicologic neuropathology investigations, in both animals and humans, will be an increased use of noninvasive neural imaging and greater preference for in situ molecular ("omic") methods, which provide functional information in a structural context. These trends will significantly enhance the ability of scientists to translate animal data to human situations, thereby improving our understanding of disease mechanisms and facilitating efforts to design new therapies for neural diseases.

Neuropathology analyses as end points during nonclinical efficacy and toxicity studies are challenging and require trained personnel and particular equipment to achieve optimal results. Accordingly, many regulatory agencies have produced explicit guidelines for designing and performing neuropathology assessments for nonclinical studies. This compilation of international regulatory guidance for toxicologic neuropathology end points represents a set of criteria recommended for general toxicity studies and specialized neurotoxicity studies that should facilitate the efforts of individuals who plan, perform, analyze, and report neuropathology evaluations in nonclinical toxicity studies.

Bolon B.,GEMpath Inc.
Toxicologic pathology | Year: 2011

Investigations in toxicologic neuropathology are complex undertakings because of the intricate spatial and temporal diversity in the anatomic, functional, and molecular organization of the central and peripheral nervous systems. This compilation of toxicologic neuropathology resources has been designed to consolidate a broad range of useful neurobiology, neuropathology, and neurotoxicology resources in a single reference. This collection will increase familiarity with the basic knowledge, skills, and tools required for the proficient practice of toxicologic neuropathology and should help to improve the analysis and interpretation of pathology data sets from neural tissues in toxicology studies.

The continuing education course on Developmental Neurotoxicity Testing (DNT) was designed to communicate current practices for DNT neuropathology, describe promising innovations in quantitative analysis and noninvasive imaging, and facilitate a discussion among experienced neuropathologists and regulatory scientists regarding suitable DNT practices. Conventional DNT neuropathology endpoints are qualitative histopathology and morphometric endpoints of particularly vulnerable sites (e.g., cerebral, cerebellar, or hippocampal thickness). Novel imaging and stereology measurements hold promise for automated analysis of factors that cannot be effectively examined in routinely processed specimens (e.g., cell numbers, fiber tract integrity). The panel recommended that dedicated DNT neuropathology data sets be acquired on a minimum of 8 sections (for qualitative assessment) or 3 sections (for quantitative linear and stereological analyses) using a small battery of stains to examine neurons and myelin. Where guidelines permit discretion, immersion fixation is acceptable for younger animals (postnatal day 22 or earlier), and peripheral nerves may be embedded in paraffin. Frequent concerns regarding DNT data sets include false-negative outcomes due to processing difficulties (e.g., lack of concordance among sections from different animals) and insensitive analytical endpoints (e.g., qualitative evaluation) as well as false-positive results arising from overinterpretation or misreading by inexperienced pathologists.

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