Investigation into diagnostic agreement using automated computer-assisted histopathology pattern recognition image analysis

Intestinal morphometry and cell density features in tropical farmed fish: A methodological approach

The digestive tract of fish has many morphological adaptations related to habitat and nutrition. Intestinal biometry may reflect these adaptations. Here, we aimed to describe histometric patterns in farmed fish and their relationship with feeding by using a standardized protocol considering cell density by tissue area. Five juvenile specimens of each species (Pseudoplatystoma corruscans, Piaractus mesopotamicus, and Oreochromis niloticus) were used. O. niloticus possessed higher intestinal weight and length besides higher intestinal quotient and intestinal somatic index than the other species. The general histological composition was similar between species. However, P. corruscans showed differences in thickness between the anterior and posterior segments. O. niloticus had thinner serosa and muscularis layers than the other species. The cell density was distinct in both species and segments. Comparing the intestinal segments, O. niloticus displayed the lowest count of granulocytes. Goblet cell density was lower in P. mesopotamicus in all segments. However, the volume of these cells was higher in the anterior and middle anterior segments. Our data demonstrated that intestinal structural plasticity is associated with the difference in feeding habits. Here, we used quantitative standardized histometric criteria to understand the morphophysiological diversity of the fish digestive tract, and this technique can be applied in future studies to evaluate changes in the digestive tracts of vertebrates.

Digital Microscopy, Image Analysis, and Virtual Slide Repository

Advancements in technology and digitization have ushered in novel ways of enhancing tissue-based research via digital microscopy and image analysis. Whole slide imaging scanners enable digitization of histology slides to be stored in virtual slide repositories and to be viewed via computers instead of microscopes. Easier and faster sharing of histologic images for teaching and consultation, improved storage and preservation of quality of stained slides, and annotation of features of interest in the digital slides are just a few of the advantages of this technology. Combined with the development of software for digital image analysis, digital slides further pave the way for the development of tools that extract quantitative data from tissue-based studies. This review introduces digital microscopy and pathology, and addresses technical and scientific considerations in slide scanning, quantitative image analysis, and slide repositories. It also highlights the current state of the technology and factors that need to be taken into account to insure optimal utility, including preanalytical considerations and the importance of involving a pathologist in all major steps along the digital microscopy and pathology workflow.

Digital Image Analyses on Whole-Lung Slides in Mouse Models of Acute Pneumonia

Descriptive histopathology of mouse models of pneumonia is essential in assessing the outcome of infections, molecular manipulations, or therapies in the context of whole lungs. Quantitative comparisons between experimental groups, however, have been limited to laborious stereology or ill-defined scoring systems that depend on the subjectivity of a more or less experienced observer. Here, we introduce self-learning digital image analyses that allow us to transform optical information from whole mouse lung sections into statistically testable data. A pattern-recognition-based software and a nuclear count algorithm were adopted to quantify user-defined pathologies from whole slide scans of lungs infected with Streptococcus pneumoniae or influenza A virus compared with PBS-challenged lungs. The readout parameters "relative area affected" and "nuclear counts per area" are proposed as relevant criteria for the quantification of lesions from hematoxylin and eosin-stained sections, also allowing for the generation of a heat map of, for example, immune cell infiltrates with anatomical assignments across entire lung sections. Moreover, when combined with immunohistochemical labeling of marker proteins, both approaches are useful for the identification and counting of, for example, immune cell populations, as validated here by direct comparisons with flow cytometry data. The solutions can easily and flexibly be adjusted to specificities of different models or pathogens. Automated digital analyses of whole mouse lung sections may set a new standard for the user-defined, high-throughput comparative quantification of histological and immunohistochemical images. Still, our algorithms established here are only a start, and need to be tested in additional studies and other applications in the future.

Combined targeting of Raf and Mek synergistically inhibits tumorigenesis in triple negative breast cancer model systems

Aberrant Ras-MAPK signaling from receptor tyrosine kinases (RTKs), including epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor-2 (HER2), is a hallmark of triple negative breast cancer (TNBC); thus providing rationale for targeting the Ras-MAPK pathway. Components of this EGFR/HER2-Ras-Raf-Mek-Erk pathway were co-targeted in the MDA-MB-231 and MDA-MB-468 human TNBC cell lines, and in vitro effects on signaling and cytotoxicity, as well as in vivo effects on xenograft tumor growth and metastasis were assessed. The dual EGFR/HER2 inhibitor lapatinib (LPN) displayed greater cytotoxic potency and MAPK signaling inhibition than the EGFR inhibitor erlotinib, suggesting both EGFR and HER2 contribute to MAPK signaling in this TNBC model. The Raf inhibitor sorafenib (SFN) or the Mek inhibitor U0126 suppressed MAPK signaling to a greater extent than LPN; which correlated with greater cytotoxic potency of SFN, but not U0126. However, U0126 potentiated the cytotoxic efficacy of LPN and SFN in an additive and synergistic manner, respectively. This in-series Raf-Mek co-targeting synergy was recapitulated in orthotopic mouse xenografts, where SFN and the Mek inhibitor selumitinib (AZD6244) inhibited primary tumor growth and pulmonary metastasis. Raf and Mek co-inhibition exhibits synergy in TNBC models and represent a promising combination therapy for this aggressive breast cancer type.

cFOS-SOX9 Axis Reprograms Bone Marrow-Derived Mesenchymal Stem Cells into Chondroblastic Osteosarcoma

Bone marrow-derived mesenchymal stem cells (BMSCs) are proposed as the cells of origin of several subtypes of osteosarcoma (OS). However, signals that direct BMSCs to form different subtypes of OS are unclear. Here we show that the default tumor type from spontaneously transformed p53 knockout (p53_KO) BMSCs is osteoblastic OS. The development of this default tumor type caused by p53 loss can be overridden by various oncogenic signals: RAS reprograms p53_KO BMSCs into undifferentiated sarcoma, AKT enhances osteoblastic OS, while cFOS promotes chondroblastic OS formation. We focus on studying the mechanism of cFOS-induced chondroblastic OS formation. Integrated genome-wide studies reveal a regulatory mechanism whereby cFOS binds to the promoter of a key chondroblastic transcription factor, Sox9, and induces its transcription in BMSCs. Importantly, SOX9 mediates cFOS-induced cartilage formation in chondroblastic OS. In summary, oncogenes determine tumor types derived from BMSCs, and the cFOS-SOX9 axis is critical for chondroblastic OS formation.

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The default tumor type from p53_KO BMSCs is osteoblastic OS

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Oncogenes reprogram p53_KO BMSCs into different sarcomas

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cFOS promotes chondroblastic OS from p53_KO BMSCs

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SOX9 is a mediator of cFOS in promoting chondroblastic OS

Cell and region specificity of Aryl hydrocarbon Receptor (AhR) system in the testis and the epididymis

Aryl hydrocarbon receptor (AhR) plays multiple important functions in adaptive responses. Exposure to AhR ligands may produce an altered metabolic activity controlled by the AhR pathways, and consequently affect drug/toxin responses, hormonal status and cellular homeostasis. This research revealed species-, cell- and region-specific pattern of the AhR system expression in the rat and human testis and epididymis, complementing the existing knowledge, especially within the epididymal segments. The study showed that AhR level in the rat and human epididymis is higher than in the testis. The downregulation of AhR expression after TCDD treatment was revealed in the spermatogenic cells at different stages and the epididymal epithelial cells, but not in the Sertoli and Leydig cells. Hence, this basic research provides information about the AhR function in the testis and epididymis, which may provide an insight into deleterious effects of drugs, hormones and environmental pollutants on male fertility.

Validation of Whole-Slide Imaging for Histolopathogical Diagnosis: Current State

Rapid advances in informatics and technological improvements have led to the development of high-throughput whole-slide imaging (WSI) scanners able to produce high-quality digital images, which allow achieving a correct diagnosis of the biopsies using virtual viewers. This technology is currently prepared to be introduced in the departments of pathology for routine diagnosis. The aim of this review is to analyze the current evidence regarding the use of WSI in primary or routine diagnosis in the different subspecialties of pathology. An increasing number of studies have shown almost perfect inter- and intraobserver agreement between the diagnoses obtained with WSI and the classical diagnoses based on conventional light microscopy. The only exception seems to be cytology, which still requires some technological development. Although validation studies are needed in some areas of pathology, growing evidence indicates that WSI is a reliable tool for routine diagnosis. Pathologists have a positive perception of the ergonomics of the workstations, the low magnification of WSI and the possibility of making annotations and measurements. WSI can be used from any device and anywhere, thereby providing great opportunities for teleconsultation. New technologies such as the recognition of histopathology patterns using image analysis may facilitate diagnosis and improve the reproducibility among pathologists in the future.

Image Analysis-Based Approaches for Scoring Mouse Models of Colitis

Mouse models of inflammatory bowel disease are critical for basic and translational research that is advancing the understanding and treatment of this disease. Assessment of these mouse models frequently relies on histologic endpoints. In recent years, whole slide imaging and digital pathology-based image analysis platforms have become increasingly available for implementation into the pathology workflow. These automated image analysis approaches allow for nonbiased quantitative assessment of histologic endpoints. In this study, the authors sought to develop an image analysis workflow using a commercially available image analysis platform that requires minimal training in image analysis or programming, and this workflow was used to score 2 mouse models of colitis that are primarily characterized by immune cell infiltrates in the lamina propria. Although the software was unable to accurately and consistently segment hematoxylin and eosin–stained sections, automated quantification of CD3 immunolabeling resulted in strong correlations with the pathologist’s score in all studies and allowed for the identification of 8 of the 9 differences among treatment groups that were identified by the pathologist. These results demonstrate not only the ability to incorporate solutions based on image analysis into the pathologist’s workflow but also the importance of immunohistochemical or histochemical surrogates for the incorporation of image analysis in histologic assessments.

Digital pathology and image analysis augment biospecimen annotation and biobank quality assurance harmonization

Standardization of biorepository best practices will enhance the quality of translational biomedical research utilizing patient-derived biobank specimens. Harmonization of pathology quality assurance procedures for biobank accessions has lagged behind other avenues of biospecimen research and biobank development. Comprehension of the cellular content of biorepository specimens is important for discovery of tissue-specific clinically relevant biomarkers for diagnosis and treatment. While rapidly emerging technologies in molecular analyses and data mining create focus on appropriate measures for minimizing pre-analytic artifact-inducing variables, less attention gets paid to annotating the constituent makeup of biospecimens for more effective specimen selection by biobank clients. Both pre-analytic tissue processing and specimen composition influence acquisition of relevant macromolecules for downstream assays. Pathologist review of biorepository submissions, particularly tissues as part of quality assurance procedures, helps to ensure that the intended target cells are present and in sufficient quantity in accessioned specimens. This manual procedure can be tedious and subjective. Incorporating digital pathology into biobank quality assurance procedures, using automated pattern recognition morphometric image analysis to quantify tissue feature areas in digital whole slide images of tissue sections, can minimize variability and subjectivity associated with routine pathologic evaluations in biorepositories. Whole-slide images and pathologist-reviewed morphometric analyses can be provided to researchers to guide specimen selection. Harmonization of pathology quality assurance methods that minimize subjectivity and improve reproducibility among collections would facilitate research-relevant specimen selection by investigators and could facilitate information sharing in an integrated network approach to biobanking.

Whole-slide imaging and automated image analysis: considerations and opportunities in the practice of pathology

Digital pathology, the practice of pathology using digitized images of pathologic specimens, has been transformed in recent years by the development of whole-slide imaging systems, which allow for the evaluation and interpretation of digital images of entire histologic sections. Applications of whole-slide imaging include rapid transmission of pathologic data for consultations and collaborations, standardization and distribution of pathologic materials for education, tissue specimen archiving, and image analysis of histologic specimens. Histologic image analysis allows for the acquisition of objective measurements of histomorphologic, histochemical, and immunohistochemical properties of tissue sections, increasing both the quantity and quality of data obtained from histologic assessments. Currently, numerous histologic image analysis software solutions are commercially available. Choosing the appropriate solution is dependent on considerations of the investigative question, computer programming and image analysis expertise, and cost. However, all studies using histologic image analysis require careful consideration of preanalytical variables, such as tissue collection, fixation, and processing, and experimental design, including sample selection, controls, reference standards, and the variables being measured. The fields of digital pathology and histologic image analysis are continuing to evolve, and their potential impact on pathology is still growing. These methodologies will increasingly transform the practice of pathology, allowing it to mature toward a quantitative science. However, this maturation requires pathologists to be at the forefront of the process, ensuring their appropriate application and the validity of their results. Therefore, histologic image analysis and the field of pathology should co-evolve, creating a symbiotic relationship that results in high-quality reproducible, objective data.

A novel noninvasive method for evaluating experimental lung metastasis in mice

Metastasis remains the most significant problem in the field of cancer. The biologic complexity that characterizes metastasis requires relevant in vivo models. When using murine models for pulmonary metastasis, longitudinal studies are valuable for following the progression of metastatic burden. Currently, the progression of pulmonary metastatic burden in experimental mice over time is monitored through advanced imaging approaches or the clinical assessment of morbidity. Because clinical signs of morbidity are often vague and unpredictable, an inexpensive and reproducible method to detect advanced metastatic burden-before the development of mortality-is needed. We have developed a noninvasive technique for assessing pulmonary metastatic burden in laboratory mice. The pulmonary assessment of advanced metastasis (PAAM) test is performed by restraining an awake mouse and gently applying pressure with the index finger under the xiphoid process. This pressure reduces the diaphragmatic component to respiration. Mice with advanced lung metastases show transient signs of respiratory distress within 3 s of the application of this pressure. Using PAAM in 4 distinct models (including sarcoma and mammary carcinoma histologies) of experimental (tail vein) pulmonary metastasis (n = 114 mice), among 3 independent evaluators yielded 94% positive and negative predictive values, which were validated by histologic assessment of postmortem lung tissue. PAAM is a simple, reproducible, and efficient method to assist in the detection of advanced pulmonary metastasis in mice and contributes to their humane care during longitudinal studies.