Jose J. Galvez

Prostatic intraepithelial neoplasia in genetically engineered mice

Several mouse models of human prostate cancer were studied to identify and characterize potential precursor lesions containing foci of atypical epithelial cells. These lesions exhibit a sequence of changes suggesting progressive evolution toward malignancy. Based on these observations, a grading system is proposed to classify prostatic intraepithelial neoplasia (PIN) in genetically engineered mice (GEM). Four grades of GEM PIN are proposed based on their architecture, differentiation pattern, and degree of cytological atypia. PIN I lesions have one or two layers of atypical cells. PIN II has two or more layers of atypical cells. PIN III has large, pleomorphic nuclei with prominent nucleoli and the cells tend to involve the entire lumen with expansion of the duct outlines. PIN IV lesions contain atypical cells that fill the lumen and bulge focally into, and frequently compromise, the fibromuscular sheath. Within the same cohorts, the lower grade PINs first appear earlier than the higher grades. Morphometric and immunohistochemical analyses confirm progressive change. Although the malignant potential of PIN IV in mice has not been proven, GEM PIN is similar to human PIN. This PIN classification system is a first step toward a systematic evaluation of the biological potential of these lesions in GEM.

C-reactive protein impairs the endothelial glycocalyx resulting in endothelial dysfunction

AIMS Inflammation is pivotal in atherosclerosis and a key early step is endothelial dysfunction. C-reactive protein, the prototypic marker of inflammation, and cardiovascular risk marker have been shown to promote atherogenesis. Increased levels of C-reactive protein are associated with endothelial dysfunction. The glycocalyx decorates the luminal surface and affords critical protection of the endothelium. Thus, the aim of the study was to examine the effect of C-reactive protein on the endothelial glycocalyx. METHODS AND RESULTS Human aortic endothelial cells (HAECs) were incubated with C-reactive protein at different concentrations (0, 12.5, 25, and 50 microg/mL) with boiled C-reactive protein as a control. For in vivo experiments, human C-reactive protein was injected into rats and human serum albumin was used as a control. Endothelial glycocalyx thickness was examined by transmission electron microscopy. Hyaluronan (HA) was examined in the supernatant of HAECs and in plasma and surface expression of heparan sulfate (HS) was quantified. C-reactive protein dose-dependently increased HA release in vitro and in vivo (P < 0.01). Also, glycocalyx thickness was significantly decreased (P < 0.05). Western blotting for HS showed significant reduction in expression of HS, one of the main glycosaminoglycans in the glycocalyx, with C-reactive protein treatment. There was a significant positive correlation between HA release and monocyte-endothelial cell adhesion, plasminogen activator inhibitor-1, and intercellular adhesion molecule-1 release and a negative correlation with endothelial nitric oxide synthase activity. CONCLUSION Collectively, these data suggest that C-reactive protein impairs glycocalyx function, resulting in endothelial dysfunction.

Diagnostic concordance of telecytology and conventional cytology for evaluating breast aspirates

OBJECTIVE To evaluate the diagnostic concordance between static electronic images versus glass slides for breast fine needle aspiration (FNA) cytology. STUDY DESIGN Nine malignant and 12 benign breast FNA cases were imaged using the Roche Image Manager, at a resolution of 1,024 x 768 pixels. A cytotechnologist or pathology resident selected five to nine representative images per case. Case histories and images were assembled into hypertext documents. Two pathologist blindly made diagnoses for each case based on the images and the clinical history and independently made diagnoses for the glass slides, also evaluating each set of images and glass slides for a list of cellular features. RESULTS The two pathologist had concordance rates of 90.5% and 66.7% between their image and glass diagnoses. For each pathologists discordant cases, 100.0% and 85.7%, respectively, were due chiefly to suspicious rather than definitive diagnoses. CONCLUSION Evaluation of the electronic images indicated that almost all the cellular features were comparable to those viewed though a microscope.

Validation: The New Challenge for Pathology

Modern pathologists have been challenged to “validate” mouse models of human cancer. Validation requires matching of morphological attributes of the model to human disease. Computers can assist in the validation process. However, adequate controlled, computer-readable vocabularies that can match terms do not currently exist in mouse pathology. Further, current standard diagnostic terminologies do not include the new concepts discussed here such as pathway pathology and mammary intraepithelial neoplasia. The terminologies must be revised and improved to meet the challenge. Human medicine has traditionally used “guilt-by-association” to validate interpretations of disease. Experimental pathology uses experimental verification exemplified by “test-by-transplantation.” Genetically Engineered Mice (GEM) develop unique tumor phenotypes bringing new structural-functional insights and reevaluation of concepts. Novel GEM-related tumors appear in all organ systems but mouse models of human breast cancer are prototypes. For example, mammary tumors induced by Mouse Mammary Tumor Virus (MMTV), chemical, radiation or other carcinogenic stimuli have limited phenotypes. These “spontaneous” or induced mammary tumors have never resembled human breast cancers. GEM tumors created with genes associated with human cancer are strikingly different. GEM tumors have unique histological phenotypes. Depending on the genes, the tumors may: 1) resemble MMTV-induced tumors, 2) display “signature” phenotypes, and 3) mimic human breast cancers. The phenotypes can be placed into structural and functional clusters with shared characteristics leading to the concepts of Pathway Pathology: tumor phenotype reflects the genotype.

Id-1 is not expressed in the luminal epithelial cells of mammary glands

BackgroundThe family of inhibitor of differentiation/DNA binding (Id) proteins is known to regulate development in several tissues. One member of this gene family, Id-1, has been implicated in mammary development and carcinogenesis. Mammary glands contain various cell types, among which the luminal epithelial cells are primarily targeted for proliferation, differentiation and carcinogenesis. Therefore, to assess the precise significance of Id-1 in mammary biology and carcinogenesis, we examined its cellular localization in vivo using immunohistochemistry.MethodsExtracts of whole mammary glands from wild type and Id-1 null mutant mice, and tissue sections from paraffin-embedded mouse mammary glands from various developmental stages and normal human breast were subjected to immunoblot and immunohistochemical analyses, respectively. In both these procedures, an anti-Id-1 rabbit polyclonal antibody was used for detection of Id-1.ResultsIn immunoblot analyses, using whole mammary gland extracts, Id-1 was detected. In immunohistochemical analyses, however, Id-1 was not detected in the luminal epithelial cells of mammary glands during any stage of development, but it was detected in vascular endothelial cells.ConclusionId-1 is not expressed in the luminal epithelial cells of mammary glands.

The Tumor Pathology of Genetically Engineered Mice: A New Approach to Molecular Pathology

Publisher Summary Genetically engineered mice (GEM) develop novel disease patterns that create new challenges for comparative pathology that could not have been envisioned. The fundamental genetic alterations introduced into GEM have unique effects on the microscopic structure of tumors. This chapter presents an accurate picture of how specific abnormalities of molecular function influence tumor morphology. Gene-specific tumor phenotypes can now be recognized. Most important, the microscopic patterns of human and GEM cancers are nearly identical when carrying the same genetic aberrations. Currently available models provide the basis for organizing these newer observations and assessing their significance, their ramifications, their internal contradictions, and their applicability to existing scientific paradigms. The chapter is the first step in an iterative process that seeks to summarize, organize, and assess the new functional-structural knowledge base and how it applies to naturally occurring cases in other animals and humans. The molecular revolution and the sequencing of genomes have brought tremendous new insights into disease mechanisms but have had relatively little impact on the discipline of anatomic pathology. Pathologists give credence to molecular pathology, but this new knowledge has thus far not resulted in fundamental changes in the organ- and cell-centric approach to pathology. Although the organ systems approach is not necessarily inaccurate or incorrect, the time has come to assess the structure of neoplastic disease from the perspective of the genes and their products.

Structured Reporting in Anatomic Pathology for Coclinical Trials: The caELMIR Model

Electronic media, with their tremendous potential for storing, retrieving, and integrating data, are an essential part of modern collaborative multidisciplinary science. Structured reporting is a fundamental aspect of keeping accurate, searchable electronic records. This discussion on structured reporting in anatomic pathology for pre- and coclinical trials in animal models provides background information for scientists who are not familiar with structured reporting. Practical examples are provided using a working database system for preclinical research-caELMIR (Cancer Electronic Laboratory Management Information and Retrieval)-developed by the U.S. National Cancer Institutes (NCIs) Mouse Models of Human Cancers Consortium (MMHCC).