Digital synthesis of histological stains using micro-structured and multiplexed virtual staining of label-free tissue

Histological staining is a vital step used to diagnose various diseases and has been used for more than a century to provide contrast to tissue sections, rendering the tissue constituents visible for microscopic analysis by medical experts. However, this process is time-consuming, labor-intensive, expensive and destructive to the specimen. Recently, the ability to virtually-stain unlabeled tissue sections, entirely avoiding the histochemical staining step, has been demonstrated using tissue-stain specific deep neural networks. Here, we present a new deep learning-based framework which generates virtually-stained images using label-free tissue, where different stains are merged following a micro-structure map defined by the user. This approach uses a single deep neural network that receives two different sources of information at its input: (1) autofluorescence images of the label-free tissue sample, and (2) a digital staining matrix which represents the desired microscopic map of different stains to be virtually generated at the same tissue section. This digital staining matrix is also used to virtually blend existing stains, digitally synthesizing new histological stains. We trained and blindly tested this virtual-staining network using unlabeled kidney tissue sections to generate micro-structured combinations of Hematoxylin and Eosin (H&E), Jones silver stain, and Masson's Trichrome stain. Using a single network, this approach multiplexes virtual staining of label-free tissue with multiple types of stains and paves the way for synthesizing new digital histological stains that can be created on the same tissue cross-section, which is currently not feasible with standard histochemical staining methods.Comment: 19 pages, 5 figures, 2 table

Evaluation of fingerprint development reagents for biological stain detection

Some latent fingerprint development techniques rely on the reaction with amino acids within the fingerprint and then either change in color or fluoresce to help visualize this fingerprint. Amino acids are the building blocks of proteins and are present in all biological fluid. Thus, these developers should be able to also locate biological stains. In a previous study, ninhydrin was shown to be able to locate biological stains. Two more latent fingerprint developers are introduced as possible universal biological stain detectors: 1,8-diazafluoren-9-one (DFO), and 1,2-indanedione (1,2-IND). Five biological stains were used to test these chemicals: 1:500 diluted blood, saliva, semen, sweat, and urine. A new heating method was also introduced for a more portable application. The hair dryer heating method was optimized for the three chemicals with two traditional oven heating methods: the oven setting at 70oC and the oven setting at 100oC. These chemicals were also examined for their effectiveness on aged samples. Samples aged for three different time intervals were used: 4 weeks, 8 weeks, and 16 weeks. The hair dryer heating method was found to be viable for all three chemicals for each of the biological stains except the 1:500 diluted blood. With the application of the hair dryer for less than 3 minutes, most stains were visible for all three chemicals. 1,2-IND gave slightly different color changes for sweat and the other biological stains. This property can possibly be used to guide subsequent specific body fluids testing. All three chemicals lost their effectiveness as the stain became older. One-month-old stains still gave similar results as fresh stains, but after 2 months, the color became fainter and was barely visible after 4 months. The next stage of this study applied these chemicals as a guide for wearer DNA extraction from worn clothing. Sampling for wearer DNA has mostly been an educated guess with little guidance as to where an abundance of DNA is located. Fingerprint developers can react with amino acids, and cells contain abundant amino acids. Thus, these chemicals may react more to areas with abundant cells. Wearer DNA was extracted from collars of donated shirts before and after the chemical applications to determine the effectiveness of these chemicals as DNA detectors. Of the three collars tested, ninhydrin reacted completely with two of the collars, making any distinction between areas with abundant DNA and areas with no DNA difficult. In addition, the quantitation data of the ninhydrin samples showed no advantage in using ninhydrin as a wearer DNA locator. DFO was shown to have some detrimental effects on the DNA or the DNA extraction and quantitation process. The quantitation data for DFO also showed no advantage in using DFO as a wearer DNA locator. 1,2-IND showed promising results and was the most likely candidate as a wearer DNA locator. All areas that reacted with 1,2-IND produced at least one sample having higher than 0.01 nanograms per microliter of DNA and would be considered viable for DNA profiling

Near-infrared imaging of demineralization on the occlusal surfaces of teeth without the interference of stains.

Most new caries lesions are found in the pits and fissures of the occlusal surface. Radiographs have extremely low sensitivity for early occlusal decay, and by the time the lesion is severe enough to appear on a radiograph, it typically has penetrated well into the dentin and surgical intervention is required. The occlusal surfaces are often heavily stained, and visual and tactile detection have poor sensitivity and specificity. Previous near-infrared imaging studies at wavelengths beyond 1300 nm have demonstrated that stains are not visible and demineralization on the occlusal surfaces can be viewed without interference from stains. The objective of our study is to determine how the contrast between sound and lesion areas on occlusal surfaces varies with wavelength from the visible to 2350 nm and determine to what degree stains interfere with that contrast. The lesion contrast for reflectance is measured in 55 extracted teeth with suspected occlusal lesions from 400 to 2350 nm employing silicon and indium gallium arsenide imaging arrays. In addition, the lesion contrast is measured on 25 extracted teeth with suspected occlusal lesions from 400 to 1600 nm in reflectance and from 830 to 1400 nm in transillumination before and after stains are removed using a ultrasonic scaler. The highest lesion contrast in reflectance is measured at wavelengths >1700  nm. Stains interfere significantly at wavelengths <1150  nm (400 to 1150) for both reflectance and transillumination measurements. Our study suggests that the optimum wavelengths for imaging decay in the occlusal surfaces are >1700  nm for reflectance (1700 to 2350 nm) and near 1300 nm (1250 to 1350 nm) for transillumination

Moisture conditions in coated wood panels during 18 months natural weathering at five sites in Europe

Wood moisture content of coated panels of Scots pine sapwood was recorded during 18 months natural weathering in Vienna by logging electric resistance and temperature near the surface. Eight coating systems with various film thicknesses were used, including three solvent borne alkyd stains, three water borne acrylic stains and two water borne acrylic paints. At five sites in Europe wood moisture content of panels coated with three solvent borne alkyd stains, a brow acrylic stain and a white opaque acrylic paint was recorded weekly by changes in panel mass. Fluctuations in wood moisture content were influenced by the film thickness, moisture protection and colour of the coating systems used. Degradation phenomena led to decreasing moisture protection of less durable coating systems over time of exposure. Differences between the exposure sites were relatively low, except the site in the UK where moisture conditions were higher

An investigation into the enhancement of fingermarks in blood on fruit and vegetables

A number of studies have reported the successful enhancement of latent fingermarks on fruit and vegetables. A study was set up to identify the most effective technique for the enhancement of fingermarks in blood on various fruit and vegetables. The enhancement techniques targeted different components in blood and consisted of protein stains (e.g. acid black 1), peroxidase reagents (e.g. leuco crystal violet) and amino acid stains (e.g. ninhydrin). Different variables such as the ageing periods of the marks and a diminishing series were employed to assess the suitability and sensitivity of the enhancement techniques.Overall, the use of different protein stains appeared to be the most effective techniques for the enhancement of fingermarks in blood on fruit and vegetables. In addition, the aubergine and cucumber skins appeared to be the most responsive surface to the different chemical techniques during enhancement. On the contrary, little or no enhancement was achieved for fingermarks in blood on the nectarine fruit

SOX10 commonly stains scar in Mohs sections

Sox10 immunostaining is used for the diagnosis and margin evaluation of melanocytic lesions. Sox10 was initially thought not to stain fibrohistiocytic processes. Consequently, it was believed to reliably distinguish desmoplastic melanoma from scar. However, recent data from formalin sections suggest Sox10 is less specific than previously thought. In this report, we demonstrate that Sox10-stained Mohs sections commonly show strong, fractional staining of scar. When using Sox10 with frozen section immunohistochemistry, Mohs practitioners should recognize the potential of this marker to stain scar to avoid overdiagnosis of desmoplastic melanoma