More than meets the eye: the changing face of histopathology

Crohn's Disease: Basic Characteristics of the Disease, Diagnostic Methods, the Role of Biomarkers, and Analysis of Metalloproteinases: A Review

Crohn's disease is a chronic inflammatory bowel disease that affects the ileum and/or large intestine. At the same time, it can also affect any other part of the human body, i.e., from the mouth to the anus. In Crohn's disease, the physiology and functioning of the epithelial barrier are inhibited due to the correlation of various factors, such as the environment, genetic susceptibility or intestinal microbiota. The symptoms are very troublesome and cause a significant reduction in quality of life, sometimes occurring with paralyzing permanent damage to the digestive tract, requiring enteral or parenteral nutrition throughout life. In order to make a proper and accurate diagnosis, an appropriately selected diagnostic path in a given clinical entity is necessary. Standard diagnostic methods are: laboratory examination, histopathological examination, endoscopic examination, X-ray, computed tomography, ultrasound examination and magnetic resonance imaging. Medical biology and the analysis of metalloproteinases have also proved helpful in diagnosing changes occurring as a result of Crohn's disease. Here we provide a thorough review of the latest reports on Crohn's disease and its genetic conditions, symptoms, morphology, diagnosis (including the analysis of Crohn's disease biomarkers, i.e., metalloproteinases) and treatment.

Detecting residents at risk of attrition - A Singapore pathology residency's experience

The SingHealth Pathology Residency Program (SHPRP) is a 5-year postgraduate training program in Singapore. We face the problem of resident attrition, which has a significant impact on the individual, program and healthcare providers. Our residents are regularly evaluated, using in-house evaluations as well as assessments required in our partnership with the Accreditation Council for Graduate Medical Education International (ACGME-I). We hence sought to determine if these assessments were able to distinguish residents who would attrite from residents who would graduate successfully. Retrospective analysis of existing residency assessments was performed on all residents who have separated from SHPRP and compared with residents currently in senior residency or graduated from the program. Statistical analysis was performed on quantitative assessment methods of Resident In-Service Examination (RISE), 360-degree feedback, faculty assessment, Milestones and our own annual departmental mock examination. Word frequency analysis of narrative feedback from faculty assessment was used to generate themes. Since 2011, 10 out of 34 residents have separated from the program. RISE, Milestone data and the departmental mock examination showed statistical significance in discriminating residents at risk of attrition for specialty-related reasons from successful residents. Analysis of narrative feedback showed that successful residents performed better in areas of organization, preparation with clinical history, application of knowledge, interpersonal communication and achieving sustained progress. Existing assessment methods used in our pathology residency program are effective in detecting residents at risk of attrition. This also suggests applications in the way that we select, assess and teach residents.

Global Research Trends of Artificial Intelligence on Histopathological Images: A 20-Year Bibliometric Analysis

Cancer has become a major threat to global health care. With the development of computer science, artificial intelligence (AI) has been widely applied in histopathological images (HI) analysis. This study analyzed the publications of AI in HI from 2001 to 2021 by bibliometrics, exploring the research status and the potential popular directions in the future. A total of 2844 publications from the Web of Science Core Collection were included in the bibliometric analysis. The country/region, institution, author, journal, keyword, and references were analyzed by using VOSviewer and CiteSpace. The results showed that the number of publications has grown rapidly in the last five years. The USA is the most productive and influential country with 937 publications and 23,010 citations, and most of the authors and institutions with higher numbers of publications and citations are from the USA. Keyword analysis showed that breast cancer, prostate cancer, colorectal cancer, and lung cancer are the tumor types of greatest concern. Co-citation analysis showed that classification and nucleus segmentation are the main research directions of AI-based HI studies. Transfer learning and self-supervised learning in HI is on the rise. This study performed the first bibliometric analysis of AI in HI from multiple indicators, providing insights for researchers to identify key cancer types and understand the research trends of AI application in HI.

Application of chemometric methods to the analysis of multimodal chemical images of biological tissues

Current histology techniques, such as tissue staining or histochemistry protocols, provide very limited chemical information about the tissues. Chemical imaging technologies such as infrared, Raman, and mass spectrometry imaging, are powerful analytical techniques with a huge potential in describing the chemical composition of sample surfaces. In this work, three images of the same tissue slice using matrix-assisted laser desorption/ionization (MALDI) mass spectrometry, infrared microspectroscopy, and an RGB picture from a conventional hematoxylin/eosin (H/E) staining are simultaneously analyzed. These fused images were analyzed by multivariate curve resolution-alternating least squares (MCR-ALS), which provided, for each component, its distribution within the tissue surface, its IR spectrum fingerprint, its characteristic mass values, and the contribution of the RGB channels of the H/E staining. Compared with the individual analysis of each of the images alone, the fusion of the three images showed the relationship between the different types of chemical/biological information and enabled a better interpretation of the tissue under study. In addition, the least-squares projection of the MCR-ALS resolved spectra of components at low spatial resolution onto the IR and RBG images at high spatial resolution, provided a better delimitation of the sample constituents on the image, giving a more precise description of their distribution on the investigated tissue. The application of this procedure can be of interest in different research areas in which a good description of the spatial distribution of the chemical constituents of the samples is needed, such as in biomedicine, food, or environmental research.

Three-Dimensional Imaging of Transparent Tissues via Metal Nanoparticle Labeling

Chemical probes are key components of the bioimaging toolbox, as they label biomolecules in cells and tissues. The new challenge in bioimaging is to design chemical probes for three-dimensional (3D) tissue imaging. In this work, we discovered that light scattering of metal nanoparticles can provide 3D imaging contrast in intact and transparent tissues. The nanoparticles can act as a template for the chemical growth of a metal layer to further enhance the scattering signal. The use of chemically grown nanoparticles in whole tissues can amplify the scattering to produce a 1.4 million-fold greater photon yield than obtained using common fluorophores. These probes are non-photobleaching and can be used alongside fluorophores without interference. We demonstrated three distinct biomedical applications: (a) molecular imaging of blood vessels, (b) tracking of nanodrug carriers in tumors, and (c) mapping of lesions and immune cells in a multiple sclerosis mouse model. Our strategy establishes a distinct yet complementary set of imaging probes for understanding disease mechanisms in three dimensions.

More than meets the eye: the changing face of histopathology

This personal reflection on trends in histopathology over the past 50 years draws upon experience of professional training and practice in the specialty in the UK. Developments during this period often resulted from new therapies (and their adverse effects) necessitating greater precision in the histopathological classification of disease, for which morphology alone can be insufficient. Conversely, histopathology has contributed to advances in our understanding of disease, leading directly to novel and more effective treatments. New infections, some involving histopathology in their discovery, have also led to fresh diagnostic challenges. Increasingly, patients have benefited from fundamental changes in professionalism in pathology. Through audit, external quality assurance, continuing professional development, standardized reporting, and increasing specialization, the consistency and reliability of histopathological diagnoses have steadily improved. Regarding the specialty's future, some now see rivalry between the morphological and molecular approaches to diagnosis and classification, particularly for neoplastic disease. An integrated strategy led by the specialty is more likely to strengthen histopathology and ultimately to have the greatest benefit for patients.