Digital Light Microscopy Research Articles

Assessment of microphytobenthos communities in the Kinzig catchment using photosynthesis-related traits, digital light microscopy and 18S-V9 amplicon sequencing

Assessment of microphytobenthos communities in the Kinzig catchment using photosynthesis-related traits, digital light microscopy and 18S-V9 amplicon sequencing

A new mechanism of cancer initiation that involves the transformation of hepatocytes into preneoplastic single hepatocytes and minifoci positive for glutathione S-transferase P-form (GST-P) in rat livers: 3D analysis using a vibratome.

Cancer initiation has long been "unknowable" in biology and medicine. In 1987, however, Moore and our research group observed single hepatocytes and minifoci that were strongly positive for glutathione S-transferase P-form (GST-P) in the rat liver as early as 2 to 3 days after initiation by diethylnitrosamine prior to the induction of GST-P+ foci and nodules. The induction of GST-P+ single hepatocytes, precursors of GST-P+ foci and nodules, was considered genetic. But, the details of the induction mechanism have remained unclear despite various examinations over a long period. Male Sprague-Dawley rats (aged 6 weeks) were fed a basal diet containing either benzyl isothiocyanate (BITC, 0.5% by wt) or 2-acetylaminofluorene (AAF, 0.04%) ad libitum for appropriate time intervals. All animals were anesthetized and euthanized. The livers obtained were excised, cut into 3- to 4-mm-thick slices and fixed in cold acetone at 4 °C. The liver specimens were then sliced into 25-µm-thick sections in PBS using an automated microtome (Vibratome 1500 Sectioning System, Vibratome Products, NY, USA). Immunocytochemical staining was performed in free solution, and the results were examined via digital light microscopy (Coolscope, Nikon, Tokyo). 3D analysis using a vibratome showed that GST-P is rapidly excreted into the bile of the liver of animals in response to strong carcinogenic stress caused by promoters or initiators. "Rapid biliary excretion of GST-P" was widely and commonly observed in all hepatocytes, GST-P+ single hepatocytes, minifoci, foci and nodules under appropriate conditions. Surprisingly, on the basis of these key findings, a new mechanism of cancer initiation involving the transformation of hepatocytes into GST-P+ single hepatocytes and minifoci in animal livers was identified. In addition, the initiation process was determined to be nongenetic because mutation is an invisible rare event. This short review describes several details about breakthrough findings on cancer initiation in rat livers, the application of 3D analysis to other cancers and the importance in the genetic analysis in malignant diseases.

Comparison of Digital Pathology and Light Microscopy Among Dermatology Residents: A Reappraisal Following Practice Changes.

Following transition to digital pathology for primary diagnosis at our institution, dermatology residents have reduced exposure to light microscopy. This study compares resident competency with light microscopy versus digital pathology following practice changes. Twenty-one dermatology residents were administered a dermatopathology examination composed of 32 diagnoses evaluated using digital slides and 32 with light microscopy. Case difficulty was graded and balanced between modalities. Diagnostic accuracy was measured using the number of correct diagnoses for each modality. Participants were surveyed regarding their experience and preferences. Diagnostic accuracy was higher with digital pathology than light microscopy (22/32 vs. 18/32, P < 0.001). Diagnostic accuracy with digital pathology increased with years of training, but accuracy with light microscopy did not. Residents with previous light microscopy experience achieved an average score of 19/32 on glass, as compared with 10/32 for those without experience (P = 0.039). Digital pathology was preferred over light microscopy (18/21, 85.7%). Trainees had better diagnostic proficiency with digital pathology and preferred this modality. Most practices at this time continue to use light microscopy. Therefore, we need to maintain proficiency in microscopy during training while concurrently preparing trainees for a digital future.

Creation of a 3D Goethite-Spongin Composite Using an Extreme Biomimetics Approach.

The structural biopolymer spongin in the form of a 3D scaffold resembles in shape and size numerous species of industrially useful marine keratosan demosponges. Due to the large-scale aquaculture of these sponges worldwide, it represents a unique renewable source of biological material, which has already been successfully applied in biomedicine and bioinspired materials science. In the present study, spongin from the demosponge Hippospongia communis was used as a microporous template for the development of a new 3D composite containing goethite [α-FeO(OH)]. For this purpose, an extreme biomimetic technique using iron powder, crystalline iodine, and fibrous spongin was applied under laboratory conditions for the first time. The product was characterized using SEM and digital light microscopy, infrared and Raman spectroscopy, XRD, thermogravimetry (TG/DTG), and confocal micro X-ray fluorescence spectroscopy (CMXRF). A potential application of the obtained goethite-spongin composite in the electrochemical sensing of dopamine (DA) in human urine samples was investigated, with satisfactory recoveries (96% to 116%) being obtained.

Machine Learning-Enabled Quantitative Analysis of Optically Obscure Scratches on Nickel-Plated Additively Manufactured (AM) Samples.

Additively manufactured metal components often have rough and uneven surfaces, necessitating post-processing and surface polishing. Hardness is a critical characteristic that affects overall component properties, including wear. This study employed K-means unsupervised machine learning to explore the relationship between the relative surface hardness and scratch width of electroless nickel plating on additively manufactured composite components. The Taguchi design of experiment (TDOE) L9 orthogonal array facilitated experimentation with various factors and levels. Initially, a digital light microscope was used for 3D surface mapping and scratch width quantification. However, the microscope struggled with the reflections from the shiny Ni-plating and scatter from small scratches. To overcome this, a scanning electron microscope (SEM) generated grayscale images and 3D height maps of the scratched Ni-plating, thus enabling the precise characterization of scratch widths. Optical identification of the scratch regions and quantification were accomplished using Python code with a K-means machine-learning clustering algorithm. The TDOE yielded distinct Ni-plating hardness levels for the nine samples, while an increased scratch force showed a non-linear impact on scratch widths. The enhanced surface quality resulting from Ni coatings will have significant implications in various industrial applications, and it will play a pivotal role in future metal and alloy surface engineering.

Endometrial Staining of CD56 (Uterine Natural Killer), BCL-6, and CD138 (Plasma Cells) Improve Diagnosis and Clinical Pregnancy Outcomes in Unexplained Infertility and Recurrent IVF Failures: Standardization of Diagnosis with Digital Pathology.

In women with unexplained infertility (UI) and recurrent in vitro fertilization (IVF) failures, the etiology is often unclear. Endometrial immune perturbations and the use of immune markers associated with these dysregulations are of great interest in the diagnosis and treatment of UI. However, reliable biomarkers and standardized quantification methods are lacking. Here, to address endometrial immune dysregulation in UI patients with recurrent IVF failures, we performed endometrial tissue sampling and immunostaining of CD56 (uNK), CD138, and BCL-6. Of these cases, 57.9% had positive CD56 in the endometrial stroma, while 46.1% had positive BCL-6 in the glandular epithelium, and 14.5% of the cases were found to be positive for CD138. Combined staining rates were 60.5%, 68.4%, and 71.05% for (CD56 or BCL-6), (CD56 or CD138), and (CD56, BCL-6, or CD138), respectively. There was a significant correlation between CD56 and BCL-6 positivity, while CD138 positivity was an independent parameter. After the recommended targeted therapy, pregnancy rates were found to increase from 58.5% to 61.6% and 73.8% in CD56-positive, (CD56- or BCL-6-positive), and (CD56-, BCL-6-, or CD138-positive) cases, respectively. Notably, a retrospective evaluation of digital pathology and light microscopy results showed a significant correlation. This study suggests that the examination of CD56, BCL-6, and CD138 in the same endometrial sample may be an effective method in determining the etiology of UI and reaching an early diagnosis and treatment options. Moreover, digital pathology can be used in the evaluation of CD56 and BCL-6 to provide objective, rapid, and reliable results.

A Comparison of Materials for Dry Surface Cleaning Soot-Coated Papers of Varying Roughness: Assessing Efficacy, Physical Surface Changes, and Residue

ABSTRACT To provide detailed information to aid conservators faced with soot removal, a survey comparing the removal of lamp black pigment, serving as a model soot, from three sample papers of differing roughness is presented. The efficacy of ten different dry surface cleaning materials—including sponges, firm and kneaded erasers, eraser crumbs, a cleaning putty, a solvent-free polydimethylsiloxane elastomer, and a dry swab—have been assessed using a handheld color spectrophotometer and image analysis of photomicrographs. Inspection of the cleaned substrates with a portable optical microscope revealed detailed information into how physical properties of cleaning materials influence the location of residual soot on the surface. 3D digital light microscopy and Fourier-transform infrared spectroscopy were used to assess physical changes to the paper surface and to identify potential residues from the materials after cleaning, respectively. The results of this model study were compared with spot cleaning tests performed on a fire-damaged paper book cover. Limited access to laboratory spaces during Covid-19 lockdown motivated this research to focus on affordable ways to perform hands-on technical research outside of the laboratory, details of which are noted throughout this paper.

Methods of dislocation structure characterization in AIIIBV semiconductor single crystals

The development pace of advanced electronics raises the demand for semiconductor single crystals and strengthens the requirements to their structural perfection. Dislocation density and distribution pattern are most important parameters of semiconductor single crystals which determine their performance as integrated circuit components. Therefore studies of the mechanisms of dislocation nucleation, slip and distribution are among the most important tasks which make researchers face the choice of suitable analytical methods. This work is an overview of advanced methods of studying and evaluating dislocation density in single crystals. Brief insight has been given on the main advantages and drawbacks of the methods overviewed and experimental data have been presented. The selective etching method (optical light microscopy) has become the most widely used one and in its conventional setup is quite efficient in the identification of scrap defects and in dislocation density evaluation by number of etch pits per vision area. Since the introduction of digital light microscopy and the related transfer from image analysis to pixel intensity matrices and measurement automation, it has become possible to implement quantitative characterization for the entire cross-section of single crystal wafers and analyze structural imperfection distribution pattern. X-ray diffraction is conventionally used for determination of crystallographic orientation but it also allows evaluating dislocation density by rocking curve broadening in double-crystal setup. Secondary electron scanning electron microscopy and atomic force microscopy allow differentiating etch patterns by origin and studying their geometry in detail. Transmission electron microscopy and induced current method allow obtaining micrographs of discrete dislocations but require labor-consuming preparation of experimental specimens. X-ray topography allows measuring bulky samples and also has high resolution but is hardly suitable for industry-wide application due to the high power consumption of measurements.Digital image processing broadens the applicability range of basic dislocation structure analytical methods in materials science and increases the authenticity of experimental results.

Eco-friendly approach for control of fungal deterioration of archaeological skeleton dated back to the Greco-Roman period

The deterioration aspects of Papio Hamadryas skeleton dating back to the Greco-Roman period, and its associated fungal strains were investigated. Also, the efficacy of two green synthesized nanoparticles to suppress fungal growth was assessed. The results stated that the accumulated dust, erosion, holes, and colour change were the most significant deterioration aspects. The digital light microscope and scanning electron microscope (SEM) showed some micro-cracks and the presence of fauna identified as woodlice. Attenuated total reflection – Fourier transform infrared spectroscopy (ATR/FTIR) proved that the archaeological bone suffered from deterioration since the wavenumber of most bands and their intensities were lower compared to the control. The most common fungal strains associated with deteriorated bones were Aspergillus flavus, Aspergillus delicatus, Aspergillus parasiticus, Aspergillus niger, Aspergillus oryzae, Penicillium expansum, Penicillium oxalicum, Penicillium digitatum, Cladosporium sp., and Paecilomyces sp. These strains exhibited varied enzymatic activity, including protease, pectinase, cellulase, and gelatinase. Green synthesized silver nanoparticles (Ag-NPs) and magnesium nanoparticles MgO-NPs showed sufficient tools to suppress radial fungal growth. The growth inhibition percentages of Ag-NPs (69.1 ± 1.3–81.5 ± 2.01%) were more efficient than those recorded by MgO-NPs (59.5 ± 0.9 – 74.3 ± 2.8%) at a concentration of 300 ppm. The inhibition percentages were decreased at low NPs (200 and 100 ppm) concentrations, but it is still a promising tool to suppress fungal growth. This study recommended that Ag-NPs at 300 ppm may be used in the disinfection of the archaeological skeleton studied.

Methods of dislocation structure characterization in A IIIB V semiconductor single crystals

The development pace of advanced electronics raises the demand for semiconductor single crystals and strengthens the requirements to their structural perfection. Dislocation density and distribution pattern are most important parameters of semiconductor single crystals which determine their performance as integrated circuit components. Therefore studies of the mechanisms of dislocation nucleation, slip and distribution are among the most important tasks which make researchers face the choice of suitable analytical methods. This work is an overview of advanced methods of studying and evaluating dislocation density in single crystals. Brief insight has been given on the main advantages and drawbacks of the methods overviewed and experimental data have been presented. The selective etching method (optical light microscopy) has become the most widely used one and in its conventional setup is quite efficient in the identification of scrap defects and in dislocation density evaluation by number of etch pits per vision area. Since the introduction of digital light microscopy and the related transfer from image analysis to pixel intensity matrices and measurement automation, it has become possible to implement quantitative characterization for the entire cross-section of single crystal wafers and analyze structural imperfection distribution pattern. X-ray diffraction is conventionally used for determination of crystallographic orientation but it also allows evaluating dislocation density by rocking curve broadening in double-crystal setup. Secondary electron scanning electron microscopy and atomic force microscopy allow differentiating etch patterns by origin and studying their geometry in detail. Transmission electron microscopy and induced current method allow obtaining micrographs of discrete dislocations but require labor-consuming preparation of experimental specimens. X-ray topography allows measuring bulky samples and also has high resolution but is hardly suitable for industry-wide application due to the high power consumption of measurements. Digital image processing broadens the applicability range of basic dislocation structure analytical methods in materials science and increases the authenticity of experimental results.

Painting the Bunting: Carotenoids and structural elements combine to produce the feather coloration of the male Painted Bunting

Abstract Male Painted Buntings (Passerina ciris) display at least 6 distinct plumage colors that encapsulate much of the visible light spectrum, yet the specific mechanisms responsible for generating this diversity of color have not been identified. Here, we show that metabolically derived carotenoids and nanostructures capable of producing structural color were ubiquitous across feather patches. We used digital photography, light microscopy, spectrophotometry, carotenoid extraction, and high-performance liquid chromatography to show that the resulting color of each feather patch depended on the concentration of carotenoids, melanins, and underlying feather nanostructures. For example, we found that the blue-violet head feathers contained low concentrations of ketolated carotenoids, which is not typical of blue-violet structurally colored feathers. Additionally, the red breast and orange belly feathers contained a green-tuned structural color visible after carotenoid extraction, which is not typical of feathers that contain ketolated carotenoids. Although, none of these abnormal combinations of carotenoids and structural coloration appeared to significantly impact feather color. Conversely, we found the purple rump, dark green greater coverts, and bright yellow-green mantle feather coloration resulted from the combination of high concentrations of carotenoids and the presence of structural color. For the first time, we identify the combination of red ketolated carotenoids and blue structural color as a mechanism to produce purple feather coloration. Identifying the specific mechanisms that give rise to the diversity of colors within this species will facilitate the study of the—to date—unknown signaling functions of colors produced through the combination of carotenoids and nanostructures in Painted Buntings and other songbirds.

Intestinal parasite infection in the Augustinian friars and general population of medieval Cambridge, UK

ObjectiveTo investigate how lifestyle may have impacted the risk of contracting intestinal parasites in medieval England . Regular clergy (such as those living in monasteries) and the lay population form interesting groups for comparison as diet and lifestyle varied significantly. Monasteries were built with latrine blocks and hand washing facilities, unlike houses of the poor. MaterialsSediment samples from the pelvis, along with control samples from feet and skull, of 19 burials of Augustinian Friars (13th-16th century), and 25 burials from All Saints by the Castle parish cemetery (10th-14th century), Cambridge. MethodsWe analysed the sediment using micro-sieving and digital light microscopy to identify the eggs of intestinal parasites. ResultsParasite prevalence (roundworm and whipworm) in the Augustinian friars was 58%, and in the All Saints by the Castle parishioners just 32% (Barnards Test score statistic 1.7176, p-value 0.092). ConclusionsIt is interesting that the friars had nearly double the infection rate of parasites spread by poor hygiene, compared with the general population. We consider options that might explain this difference, and discuss descriptions and treatment of intestinal worms in medical texts circulating in Cambridge during the medieval period. SignificanceThis is the first study to compare prevalence of parasite infection between groups with different socioeconomic status from the same location. LimitationsQuality of egg preservation was suboptimal, so our data may under-represent the true prevalence. Suggestions for further researchLarger studies with greater statistical power, covering different time periods and regions.

Density, Orientation, and Distribution of Foliar Trichomes in Selected Philippine Traditional Rice Varieties with Resistance to Scirpophaga spp.

Pest infestation restricts rice productivity and, among rice pests, the stem borers (Scirpophaga spp.) caused substantial damage of &gt; 20% yield loss. Host resistance is considered the most effective, economical, and environmentally friendly way for rice pest management, and Philippine traditional rice varieties (TRVs) are potential sources of genes useful in breeding for pest resistance. Leaf trichomes are the first physical barrier against any invading plant pests and to characterize the quantitative variations of foliar trichomes of six selected TRVs identified to have resistance – namely, Dinorado, Hinumay, Inarciaga, RED 18, C-4 Dinorado, and Mukol – these TRVs were evaluated using digital light microscopy. RED 18 consistently had the highest trichome density (5.374–9.390/mm2) in each and across the 2018 wet season (WS), 2019 WS, and 2020 dry season (DS) – even significantly higher (P &gt; 0.05) than the resistant check TKM6 (4.489–5.783/mm2). For trichome orientation, Mukol (59.151–71.617°), and Inarciaga (57.395–72.464°) consistently had higher and/or statistically comparable angle values to the resistant TKM6 (59.654–71.617°), across each and 2018 WS, 2019 WS, and 2020 DS (P &gt; 0.05). Within- and between-genotype variability showed that adaxial foliar trichomes have varying density and were not uniformly distributed across the leaf surface: densest (4.560–5.456/mm2) and mostly distributed (49.086–50.532%) in the apical zone of the leaf surface, and least dense (2.623–2.834/mm2) and rarely distributed (16.439–18.806%) in the basal zone. Based on desirable trichome traits and statistical similarities to TKM6, hierarchical cluster analysis delineated RED 18, Inarciaga, and Mukol as excellent sources of trichome traits that will improve plant structural defense against stem borers.

Converting a next-generation digital light microscope to a dark-field microscope

The working principle of a dark-field microscope is to block the central light from illuminating the preparation and to ensure that only oblique-oriented light reaches the specimen. Initially, the view appears dark, but when placing the appropriate specimen, the sample's particles change the direction of the oblique light toward the objective and ocular.1 Dark-field microscopy is useful for displaying Treponema pallidum spirochetes. However, dark-field microscopes are quite expensive compared to light microscopes and are not widely available among dermatology practices.

Full and Hollow Metal–Ceramic Beads Based on Tantalum and Alumina Produced by Alginate Gelation

Metal–ceramic composite beads containing different amounts of tantalum and alumina, particularly 100 vol% tantalum and 60–40 vol% tantalum/alumina, are produced by the alginate gelation process. Sodium alginate is used as gelling agent in the metal–ceramic suspension, while a calcium chloride solution is prepared to trigger the consolidation process. As in the previous study, different nozzles are used in order to obtain beads of three different sizes. The largest beads result to be hollow, and hence require a freeze‐drying step in order to prevent their collapse. After debinding in air, the composite beads are sintered at 1600 °C under inert atmosphere. Samples in green and sintered state are analyzed by digital light microscopy and scanning electron microscopy. Investigations by mercury intrusion porosimetry reveal that composite beads feature smaller pores compared to pure tantalum beads, as well as lower open porosity. The fracture strength is evaluated on single beads. Despite the high metallic content, both composite and pure tantalum beads show a brittle behavior. X‐ray powder diffraction (XRD) analyses reveal the presence of , , and alongside pure Ta in the samples prepared from pure tantalum. The impurities are due to reactions with Na, C, and Ca from the used additives.

Intestinal parasites in the Neolithic population who built Stonehenge (Durrington Walls, 2500 BCE).

Durrington Walls was a large Neolithic settlement in Britain dating around 2500 BCE, located very close to Stonehenge and likely to be the campsite where its builders lived during its main stage of construction. Nineteen coprolites recovered from a midden and associated pits at Durrington Walls were analysed for intestinal parasite eggs using digital light microscopy. Five (26%) contained helminth eggs, 1 with those of fish tapeworm (likely Dibothriocephalus dendriticus) and 4 with those of capillariid nematodes. Analyses of bile acid and sterol from these 5 coprolites show 1 to be of likely human origin and the other 4 to likely derive from dogs. The presence of fish tapeworm reveals that the Neolithic people who gathered to feast at Durrington Walls were at risk of infection from eating raw or undercooked freshwater fish. When the eggs of capillariids are found in the feces of humans or dogs it normally indicates that the internal organs (liver, lung or intestines) of animals with capillariasis have been eaten, and eggs passed through the gut without causing disease. Their presence in multiple coprolites provides new evidence that internal organs of animals were consumed. These novel findings improve our understanding of both parasitic infection and dietary habits associated with this key Neolithic ceremonial site.

Analysis of pore morphology in oxide electroceramics by automatic image analysis

Abstract Porosity represents one of the key parameters in the characterization of ceramic materials. Pores remaining after sintering often constitute the origin of direct mechanical or dielectric material failure. Isolated and large-scale pores in the microstructure are particularly problematic; many times these are larger than the average pore diameter. Their detection poses a particular challenge for analytics. The analytical methods used for ceramic materials either detects only part of the porosity or are greatly limited in view of area measurements. Moreover, the analysis of the morphology of detected pores is hardly possible or even impossible for the majority of methods. This research paper offers a detailed account of the qualitative analysis of porosity in oxide ceramics, with the primary focus being on possibilities for pore detection, the measured distribution functions, and the advantages of this method. This paper will show that the use of digital light microscopy together with coaxial illumination is capable of determining pore morphology and distribution in a fraction of time that would be required by conventional methods. The comparison of the measurement results, aided by well established methods for pore characterization, such as the linear intercept method (according to DIN EN ISO 13383), will enable a reliable validation of the results. Final FESEM analysis was used to enable a detailed study of the identified pores and to verify the results.

Strain maps characterize the symmetry of convergence and extension patterns during zebrafish gastrulation

During gastrulation of the zebrafish embryo, the cap of blastoderm cells organizes into the axial body plan of the embryo with left–right symmetry and head–tail, dorsal–ventral polarities. Our labs have been interested in the mechanics of early development and have investigated whether these large-scale cell movements can be described as tissue-level mechanical strain by a tectonics-based approach. The first step is to image the positions of all nuclei from mid-epiboly to early segmentation by digital sheet light microscopy, organize the surface of the embryo into multi-cell spherical domains, construct velocity fields from the movements of these domains and extract strain rate maps from the change in density of the domains. During gastrulation, tensile/expansive and compressive strains in the axial and equatorial directions are detected as anterior and posterior expansion along the anterior–posterior axis and medial–lateral compression across the dorsal–ventral axis and corresponds to the well characterized morphological movements of convergence and extension. Following gastrulation strain is represented by localized medial expansion at the onset of segmentation and anterior expansion at the onset of neurulation. In addition to linear strain, symmetric patterns of rotation/curl are first detected in the animal hemispheres at mid-epiboly and then the vegetal hemispheres by the end of gastrulation. In embryos treated with C59, a Wnt inhibitor that inhibits head and tail extension, the axial extension and vegetal curl are absent. By analysing the temporal sequence of large-scale movements, deformations across the embryo can be attributed to a combination of epiboly and dorsal convergence-extension.

Metal-Ceramic Beads Based on Niobium and Alumina Produced by Alginate Gelation.

Full metal-ceramic composite beads containing different amounts of niobium and alumina, particularly 100 vol% alumina, 100 vol% niobium, and 95/5 vol% niobium/alumina, were produced by the alginate gelation process. The suspension for bead fabrication contained sodium alginate as gelling agent and was added dropwise into a calcium chloride solution to trigger the consolidation process. After debinding in air, sintering of the composite beads was performed under inert atmosphere. Samples in green and sintered state were analyzed by digital light microscopy and scanning electron microscopy equipped with energy dispersive X-ray spectroscopy. Investigations by mercury intrusion porosimetry revealed that pure alumina beads featured smaller pores compared to composite beads, although the open porosities were comparable. The fracture strength was evaluated on single beads. Contrary to the pure alumina, the composite beads showed a clear plastic deformation. Pure niobium beads showed a ductile behavior with very large deformations. XRD analyses revealed the presence of calcium hexaluminate and beta-alumina as minor phases in the alumina beads, while the composite ones contained about 25 wt% of impurities. The impurities comprised NbO arising from the oxidation, and β-Nb2C, from the reaction with the residual sodium alginate.

Diagnostic Pitfalls of Digital Microscopy Versus Light Microscopy in Gastrointestinal Pathology: A Systematic Review.

Digital microscopy (DM) is one of the cutting-edge advances in pathology, which entails improved efficiency, diagnostic advantages, and potential application in virtual diagnosis, particularly in the current era of the coronavirus disease (COVID-19) pandemic. However, the diagnostic challenges are the remaining concerns for its wider adoption by pathologists, and these concerns should be addressed in a specific subspecialty. We aim to identify the common diagnostic pitfalls of whole slide imaging (WSI), one modality of DM, in gastrointestinal (GI) pathology. From validating studies of primary diagnosis performance, we included 16 records with features on GI cases involved, at least two weeks wash-out periods, and more than 60 case study designs. A tailored quality appraisal assessment was utilized to evaluate the risks of bias for these diagnostic accuracy studies. Furthermore, due to the highly heterogeneous studies and unstandardized definition of discordance, we extract the discordant cases in GI pathology and calculate the discrepant rate, resulting from 0.5% to 64.28%. Targeting discrepancy cases between digital microscopy and light microscopy, we demonstrate five main diagnostic pitfalls regarding WSI as follows: additional time to review slides in WSI, hard to identify dysplasia nucleus, missed organisms like Helicobacter pylori (H. pylori), specific cell recognitions, and technical issues. After detailed reviews and analysis, we generate two essential suggestions for further GI cases signing out by DM. One is to use systematized 20x scans for diagnostic workouts and requesting 40x or even 60x scans for challenging cases; another is that a high-volume slides training should be set before the real clinical application of WSI for primary diagnosis, particularly in GI pathology.