Colorimetric histology using plasmonically active microscope slides.

The human eye can distinguish as many as 10,000 different colours but is far less sensitive to variations in intensity1, meaning that colour is highly desirable when interpreting images. However, most biological samples are essentially transparent, and nearly invisible when viewed using a standard optical microscope2. It is therefore highly desirable to be able to produce coloured images without needing to add any stains or dyes, which can alter the sample properties. Here we demonstrate that colorimetric histology images can be generated using full-sized plasmonically active microscope slides. These slides translate subtle changes in the dielectric constant into striking colour contrast when samples are placed upon them. We demonstrate the biomedical potential of this technique, which we term histoplasmonics, by distinguishing neoplastic cells from normal breast epithelium during the earliest stages of tumorigenesis in the mouse MMTV-PyMT mammary tumour model. We then apply this method to human diagnostic tissue and validate its utility in distinguishing normal epithelium, usual ductal hyperplasia, and early-stage breast cancer (ductal carcinoma in situ). The colorimetric output of the image pixels is compared to conventional histopathology. The results we report here support the hypothesis that histoplasmonics can be used as a novel alternative or adjunct to general staining. The widespread availability of this technique and its incorporation into standard laboratory workflows may prove transformative for applications extending well beyond tissue diagnostics. This work also highlights opportunities for improvements to digital pathology that have yet to be explored.

Preparing Cell Smears for Staining.

Increasing use is being made of cell smears for cell-staining studies. Suspension cells can be attached to slides by drying, and cell smears can also be prepared from biopsy samples, such as needle aspirates, tissue scrapings, or freshly dissected tissues. In these procedures, a thin layer of cells is deposited on a dry slide by physical methods. The most important factor in obtaining good staining patterns is that the smear be only a single cell thick. Tissue smears do not preserve tissue architecture, but are useful for identifying pathological changes and infectious organisms in tissue samples. Cell smears are easily prepared and can be fixed readily by any of the methods used for attached cells.

Accurate assessment of nonalcoholic fatty liver disease lesions in liver allograft biopsies by a smartphone platform: A proof of concept.

Macrovesicular steatosis (MS) is a major risk factor for liver graft failure after transplantation and pathological microscopic examination of a frozen tissue section remains the gold standard for its assessment. However, the latter requires an experienced in-house pathologist for correct and rapid diagnosis as well as specific equipment that is not always available. Smartphones, which are must-have tools for everyone, are very suitable for incorporation into promising technology to generate moveable diagnostic tools as for telepathology. The study aims to compare the microscopic assessment of nonalcoholic fatty liver disease (NAFLD) spectrum in liver allograft biopsies by a smartphone microscopy platform (DIPLE device) to standard light microscopy. Forty-two liver graft biopsies were evaluated in transmitted light, using an iPhone X and the microscopy platform. A significant correlation was reported between the two different approaches for graft MS assessment (Spearman's correlation coefficient: r = .93; p < .001) and for steatohepatitis feature (r = .56; p < .001; r = .45; p < .001). Based on these findings, a smartphone integrated with a cheap microscopy platform can achieve adequate accuracy in the assessment of NAFLD in liver graft and could be used as an alternative to standard light microscopy when the latter is unavailable.

MR Imaging-Histology Correlation by Tailored 3D-Printed Slicer in Oncological Assessment.

3D printing and reverse engineering are innovative technologies that are revolutionizing scientific research in the health sciences and related clinical practice. Such technologies are able to improve the development of various custom-made medical devices while also lowering design and production costs. Recent advances allow the printing of particularly complex prototypes whose geometry is drawn from precise computer models designed on in vivo imaging data. This review summarizes a new method for histological sample processing (applicable to e.g., the brain, prostate, liver, and renal mass) which employs a personalized mold developed from diagnostic images through computer-aided design software and 3D printing. Through positioning the custom mold in a coherent manner with respect to the organ of interest (as delineated by in vivo imaging data), the cutting instrument can be precisely guided in order to obtain blocks of tissue which correspond with high accuracy to the slices imaged. This approach appeared crucial for validation of new quantitative imaging tools, for an accurate imaging-histopathological correlation and for the assessment of radiogenomic features extracted from oncological lesions. The aim of this review is to define and describe 3D printing technologies which are applicable to oncological assessment and slicer design, highlighting the radiological and pathological perspective as well as recent applications of this approach for the histological validation of and correlation with MR images.

Antecedents, development, adoption, and application of Duchenne's trocar for histopathologic studies of neuromuscular disorders in the nineteenth century.

Duchenne de Boulogne was one of the founders of clinical neurology. His name has been eponymically linked to the most common form of muscular dystrophy, originally described by him as pseudo-hypertrophic muscular paralysis or myo-sclerotic paralysis. Obtaining muscle biopsy specimens was essential to gain insight about the etiopathogenensis of the disease. Duchenne invented a novel instrument: l'emporte-pièce histologique, also known as "Duchenne's trocar," to perform muscle biopsies. Following Duchenne's design and instructions, a Parisian company, Charrière, constructed the first instrument probably in 1864. That instrument was essential for Duchenne's description of the histopathological abnormalities typical of pseudo-hypertrophic muscular paralysis. The innovative needle-biopsy technique enabled physicians to analyze the spectrum of pathological changes at varying stages of different neuromuscular diseases. Duchenne's trocar was a forerunner of several types of modern muscle-biopsy needles. His invention was instrumental in the development of the disciplines of muscle pathology and clinical myology.

Automated and Reproducible Detection of Vascular Endothelial Growth Factor (VEGF) in Renal Tissue Sections.

BACKGROUND: Manual analysis of tissue sections, such as for pathological diagnosis, requires an analyst with substantial knowledge and experience. Reproducible image analysis of biological samples is steadily gaining scientific importance. The aim of the present study was to employ image analysis followed by machine learning to identify vascular endothelial growth factor (VEGF) in kidney tissue that had been subjected to hypoxia. METHODS: Light microscopy images of renal tissue sections stained for VEGF were analyzed. Subsequently, machine learning classified the cells as VEGF+ and VEGF- cells. RESULTS: VEGF was detected and cells were counted with high sensitivity and specificity. CONCLUSION: With great clinical, diagnostic, and research potential, automatic image analysis offers a new quantitative capability, thereby adding numerical information to a mostly qualitative diagnostic approach.

Three-dimensional reconstruction with serial whole-mount sections of oral tongue squamous cell carcinoma: A preliminary study.

OBJECTIVES: Margin status and invasion pattern are prognostic factors for oral tongue squamous cell carcinoma (OTSCC). Current methods to identify these factors are limited to 2D observation; it is necessary to explore 3D reconstruction with whole-mount sample to improve the accuracy of analysis. This study aimed to study the tissue preparation, section generation, and 3D reconstruction with whole-mount OTSCC specimen. STUDY DESIGN: Two OTSCC samples were retrieved from Nanjing Stomatological Hospital, Medical School of Nanjing University. One sample was sliced into 3 equal-sized pieces and subjected to different processing schedules to determine the best method. The second sample was processed accordingly. Serial whole-mount sections of the second sample were generated, stained with HE/anticytokine antibody in intersection manner, and scanned into digital images. Digital images were aligned and reconstructed into 3D images with Hetero Genius Medical Image Manager 3D Pathology Add-On [HGMIM3D]. RESULTS: Successful serial whole-mount sections of comparable quality to traditional sections were generated. Three-dimensional images with serial whole-mount sections were successfully generated. CONCLUSIONS: Whole-mount histopathological 3D reconstruction of OTSCC was successfully generated, providing a solid foundation for comprehensive margin and invasion analysis. Although future study and improvement were needed, whole-mount histopathological 3D reconstruction proved to be a promising method in OTSCC study.

Dissection of the Mouse Pancreas for Histological Analysis and Metabolic Profiling.

We have been investigating the pancreas specific transcription factor, 1a cre-recombinase; lox-stop-lox- Kristen rat sarcoma, glycine to aspartic acid at the 12 codon (Ptf1acre/+;LSL-KrasG12D/+) mouse strain as a model of human pancreatic cancer. The goal of our current studies is to identify novel metabolic biomarkers of pancreatic cancer progression. We have performed metabolic profiling of urine, feces, blood, and pancreas tissue extracts, as well as histological analyses of the pancreas to stage the cancer progression. The mouse pancreas is not a well-defined solid organ like in humans, but rather is a diffusely distributed soft tissue that is not easily identified by individuals unfamiliar with mouse internal anatomy or by individuals that have little or no experience performing mouse organ dissections. The purpose of this article is to provide a detailed step-wise visual demonstration to guide novices in the removal of the mouse pancreas by dissection. This article should be especially valuable to students and investigators new to research that requires harvesting of the mouse pancreas by dissection for metabolic profiling or histological analyses.

Microscopy with ultraviolet surface excitation for rapid slide-free histology.

Histological examination of tissues is central to the diagnosis and management of neoplasms and many other diseases and is a foundational technique for preclinical and basic research. However, commonly used bright-field microscopy requires prior preparation of micrometre-thick tissue sections mounted on glass slides-a process that can require hours or days, contributes to cost and delays access to critical information. Here, we introduce a simple, non-destructive slide-free technique that, within minutes, provides high-resolution diagnostic histological images resembling those obtained from conventional haematoxylin and eosin histology. The approach, which we named microscopy with ultraviolet surface excitation (MUSE), can also generate shape and colour-contrast information. MUSE relies on ~280 nm ultraviolet light to restrict the excitation of conventional fluorescent stains to tissue surfaces and it has no significant effects on downstream molecular assays (including fluorescence in situ hybridization and RNA sequencing). MUSE promises to improve the speed and efficiency of patient care in both state-of-the-art and low-resource settings and to provide opportunities for rapid histology in research.

Diagnostic yield of transbronchial cryobiopsy in interstitial lung disease: a randomized trial.

BACKGROUND AND OBJECTIVE: Transbronchial lung biopsy (TBLB) is required for evaluation in selected patients with interstitial lung disease (ILD). The diagnostic yield of histopathologic assessment is variable and is influenced by factors such as the size of samples and the presence of crush artefacts left by conventional biopsy forceps. We compared the diagnostic yield and safety of TBLB with cryoprobe sampling versus conventional forceps sampling. METHODS: This randomized clinical trial analysed data for 77 patients undergoing TBLB for evaluation of ILD; patients were assigned to either a conventional-forceps group or a cryoprobe group. Two pathologists assessed the tissue samples and agreed on histopathologic diagnoses. We also compared the duration of procedures, complications and sample-quality variables. RESULTS: The most frequent diagnosis observed in the cryoprobe group was non-specific interstitial pneumonia. Histopathologic diagnoses were identified in more cases in the cryoprobe group (74.4%) than in the conventional-forceps group (34.1%) (P < 0.001), and the diagnostic yield was higher in the cryoprobe group (51.3% vs 29.1% in the conventional forceps group; P = 0.038). A larger mean area of tissue was harvested by cryoprobe (14.7 ± 11 mm(2) ) than by conventional forceps (3.3 ± 4.1 mm(2)) (P < 0.001). More grade 2 bleeding (not statistically significant) occurred in the cryoprobe group (56.4%) than in the conventional-forceps group (34.2%). No differences in other complications were observed. CONCLUSIONS: TBLB by cryoprobe is safe and potentially useful in the diagnosis of ILD. Larger multisite randomized trials are required to confirm the potential benefits of this procedure. Clinical trial registration at ClinicalTrials.gov: NCT01064609.

Systematic optimization of multiplex zymography protocol to detect active cathepsins K, L, S, and V in healthy and diseased tissue: compromise among limits of detection, reduced time, and resources.

Cysteine cathepsins are a family of proteases identified in cancer, atherosclerosis, osteoporosis, arthritis, and a number of other diseases. As this number continues to rise, so does the need for low cost, broad use quantitative assays to detect their activity and can be translated to the clinic in the hospital or in low resource settings. Multiplex cathepsin zymography is one such assay that detects subnanomolar levels of active cathepsins K, L, S, and V in cell or tissue preparations observed as clear bands of proteolytic activity after gelatin substrate SDS-PAGE with conditions optimal for cathepsin renaturing and activity. Densitometric analysis of the zymogram provides quantitative information from this low cost assay. After systematic modifications to optimize cathepsin zymography, we describe reduced electrophoresis time from 2 h to 10 min, incubation assay time from overnight to 4 h, and reduced minimal tissue protein necessary while maintaining sensitive detection limits; an evaluation of the pros and cons of each modification is also included. We further describe image acquisition by Smartphone camera, export to Matlab, and densitometric analysis code to quantify and report cathepsin activity, adding portability and replacing large scale, darkbox imaging equipment that could be cost prohibitive in limited resource settings.

Confocal microscopy with strip mosaicing for rapid imaging over large areas of excised tissue.

Confocal mosaicing microscopy is a developing technology platform for imaging tumor margins directly in freshly excised tissue, without the processing required for conventional pathology. Previously, mosaicing on 12-×-12 mm² of excised skin tissue from Mohs surgery and detection of basal cell carcinoma margins was demonstrated in 9 min. Last year, we reported the feasibility of a faster approach called "strip mosaicing," which was demonstrated on a 10-×-10 mm² of tissue in 3 min. Here we describe further advances in instrumentation, software, and speed. A mechanism was also developed to flatten tissue in order to enable consistent and repeatable acquisition of images over large areas. We demonstrate mosaicing on 10-×-10 mm² of skin tissue with 1-µm lateral resolution in 90 s. A 2.5-×-3.5 cm² piece of breast tissue was scanned with 0.8-µm lateral resolution in 13 min. Rapid mosaicing of confocal images on large areas of fresh tissue potentially offers a means to perform pathology at the bedside. Imaging of tumor margins with strip mosaicing confocal microscopy may serve as an adjunct to conventional (frozen or fixed) pathology for guiding surgery.

Laser ablation ICP-MS for quantitative biomedical applications.

LA-ICP-MS allows precise, relatively fast, and spatially resolved measurements of elements and isotope ratios at trace and ultratrace concentration levels with minimal sample preparation. Over the past few years this technique has undergone rapid development, and it has been increasingly applied in many different fields, including biological and medical research. The analysis of essential, toxic, and therapeutic metals, metalloids, and nonmetals in biomedical tissues is a key task in the life sciences today, and LA-ICP-MS has proven to be an excellent complement to the organic MS techniques that are much more commonly employed in the biomedical field. In order to provide an appraisal of the fast progress that is occurring in this field, this review critically describes new developments for LA-ICP-MS as well as the most important applications of LA-ICP-MS, with particular emphasis placed on the quantitative imaging of elements in biological tissues, the analysis of heteroatom-tagged proteins after their separation and purification by gel electrophoresis, and the analysis of proteins that do not naturally have ICP-MS-detectable elements in their structures, thus necessitating the use of labelling strategies.

Microcalcifications of the breast: a mammographic-histologic correlation study using a newly designed Path/Rad Tissue Tray.

The introduction of screening mammography has brought about a greater knowledge of early breast cancer characteristics. These improvements have led to a reduction in size of suspicious lesions and a shift from surgical to image-guided core needle biopsies (CNBs). Establishing correlation between histologic and imaging findings is required for accurate diagnosis. Currently, there are no standardized multidisciplinary protocols for evaluating such lesions. We correlated histologic and radiologic findings in mammographically detectable calcified lesions in CNBs using specially designed Path/Rad Tissue Trays (patent pending, University of Kansas). Evidence of calcification was analyzed in 440 with and without the use of tissue trays. After mammographic identification of the lesion, CNBs are harvested, placed in tissue trays, and x-rayed to confirm sampling of the lesion. Images of CNBs with calcifications are marked by the radiologists and sent to the pathologist along with the biopsies. Trays with CNBs are then placed into cassettes and sent to the laboratory where they are embedded without disturbing orientation. Identification and localization of targeted microcalcifications were accomplished by radiologists and pathologists in 68 of 71 cases when using the tissue trays compared with 292 of 369 without tissue trays. Confirmation of microcalcifications was accomplished after deeper sectioning into tissue blocks from discordant cases. In conclusion, a systematic approach is recommended to standardize reporting of calcifications. The use of Path/Rad Tissue Trays has created a level of concordance between pathologists and radiologists that previously did no exist. It improved diagnostic reliability, encouraged communication between pathologists and radiologists, and minimized false diagnoses and/or delays in cancer diagnosis.