The influence of storage time upon the real thickness of the histological brain sections

The aim of the study was to assess the effect of storage time on the actual thickness of the histological sections. The study was performed on 5 brains of adult Wistar rats. The most rapid changes occur at the beginning of the storage process, after about one month the dynamics of changes decreases, but still the thickness of the sections diminishes. It is suggested that quantitative analyses should be performed in similar period of time and the critical care should be taken not only of the chemicals and procedures used, but also of the control of environmental factors.     

Visualization of fungi in histological sections

Deparaffinized kidney sections from mice infected with Candida albicans and lung sections from mice infected with Blastomyces dermatitides were stained with the stilbene derivative, Uvitex 2B (1%), and counterstained with haemalum and eosin. Fungi selectively stained with Uvitex 2B are visualized by blue fluorescence under incident illumination with ultraviolet light. Simultaneous or consecutive illumination with transmitted light permits the assignment of fluorescent fungi to haemalum-eosin-stained structures in the section. The most practical means of achieving a high optical contrast with Uvitex 2B in sections and good haemalum-eosin staining is to use the established haemalum-eosin technique, but with a solution containing both 1% eosin and 1% Uvitex 2B in place of eosin alone. Since Uvitex 2B stains all fungi investigated so far, it affords a simple, sensitive and inexpensive method of selectively detecting opportunistic fungal infections in conventional histopathology.     

The paper chromatography as applied to histological sections

Summary The results of tissue section chromatography are given in comparison with histochemical section tests.Qualitative research concerns essential components of organism — amino acids, carbohydrates, lipids, and some steroids. Suggestions referring to quantitative prospects of the section chromatography method are given.With 6 Figures in the Text     

Reconstructing protein networks of epithelial differentiation from histological sections

MOTIVATION: For systems biology of complex stratified epithelia like human epidermis, it will be of particular importance to reconstruct the spatiotemporal gene and protein networks regulating keratinocyte differentiation and homeostasis. RESULTS: Inside the epidermis, the differentiation state of individual keratinocytes is correlated with their respective distance from the connective tissue. We here present a novel method to profile this correlation for multiple epithelial protein biomarkers in the form of quantitative spatial profiles. Profiles were computed by applying image processing algorithms to histological sections stained with tri-color indirect immunofluorescence. From the quantitative spatial profiles, reflecting the spatiotemporal changes of protein expression during cellular differentiation, graphs of protein networks were reconstructed. CONCLUSION: Spatiotemporal networks can be used as a means for comparing and interpreting quantitative spatial protein expression profiles obtained from different tissue samples. In combination with automated microscopes, our new method supports the large-scale systems biological analysis of stratified epithelial tissues.     

The application of the avidin-biotin technique to previously stained histological sections

Using the sensitive avidin-biotin peroxidase technique, a wide variety of tissue antigens can be detected in standard histological sections of both normal and pathological tissues previously stained with hematoxylin and eosin. There appears to be no detectable reduction of sensitivity with this method of "restaining" compared to the standard immunoperoxidase procedure applied to unstained tissue sections. This technique makes it possible for retrospective identification of tissue antigens when insufficient unstained material is available.     

Interferometric analysis of intrasection and intersection thickness variability associated with cryostat microtomy

Summary Mach-Zehnder interferometric measurements were used to assess the extent of section thickness variability (inter- and intrasection) associated with cryostat microtomy of adrenal sections over a typical working range of 10–20 m. Sections were obtained using a Bright's Cambridge rocking type and a Damon rotary type cryostat microtome to allow comparative analyses. The effective thickness of tissue sections after being mounted onto slides by flash drying was reduced by 90% relative to microtome section thickness setting. A linear relationship between measured thickness and microtome setting was obtained with both instruments. Thickness variability between replicate sections over the range of microtome settings approximated 11% for the rocking microtome and 5% with the rotary microtome. Average intrasection variability was found to be 7% for rocking microtome sections and 4% for sections obtained with the rotary microtome. However, this variability is a negligible source of error in cytophotometric analyses, providing replicate sections are used and an adequate number of measurements are made on mask-delimited individual cells or tissue specimen areas.     

Evaporation process in histological tissue sections for neutron autoradiography

The analysis of the distribution and density of nuclear tracks forming an autoradiography in a nuclear track detector (NTD) allows the determination of ¹⁰B atoms concentration and location in tissue samples from Boron Neutron Capture Therapy (BNCT) protocols. This knowledge is of great importance for BNCT dosimetry and treatment planning. Tissue sections studied with this technique are obtained by cryosectioning frozen tissue specimens. After the slicing procedure, the tissue section is put on the NTD and the sample starts drying. The thickness varies from its original value allowing more particles to reach the detector and, as the mass of the sample decreases, the boron concentration in the sample increases. So in order to determine the concentration present in the hydrated tissue, the application of corrective coefficients is required. Evaporation mechanisms as well as various factors that could affect the process of mass variation are outlined in this work. Mass evolution for tissue samples coming from BDIX rats was registered with a semimicro analytical scale and measurements were analyzed with software developed to that end. Ambient conditions were simultaneously recorded, obtaining reproducible evaporation curves. Mathematical models found in the literature were applied for the first time to this type of samples and the best fit of the experimental data was determined. The correlation coefficients and the variability of the parameters were evaluated, pointing to Page’s model as the one that best represented the evaporation curves. These studies will contribute to a more precise assessment of boron concentration in tissue samples by the Neutron Autoradiography technique.     

Methods of characterizing histological sections based on the AMBA/R system

There exist 2 characterization levels: karyometry and histometry. The state of the art in karyometry is relatively wide advanced. A wide spectrum of methods exists and there is often a good correlation between measured parameters and diagnosis as well as prognosis. The development of histometry is just in the first phase. This paper gives an introduction to the histometrical methods based on the AMBA/R-software-system.     

Method for histological preparation of bone sections containing titanium implants

A thin sectioning technique involving hand grinding has been developed to produce 20-40-microns-thick sections of bone-titanium implant sites. Components include: 1) surface staining of sections prior to mounting on slides so bone labels (oxytetracycline-HCl and 2,4-bis(N,N-dicarbomethyl)aminomethylfluorescein (DCAF] can be seen in sections viewed with transmitted light, 2) a pneumatic sample press for bonding sections to slides with a thin, uniform glue line and without trapped air bubbles, and 3) bonding methyl methacrylate embedded sections to clear acrylic slides with methyl methacrylate monomer to provide enhanced bond strength and grinding properties compared to those obtainable with glass slides. Sample cracking and distortion is minimized and the tissue-implant interface can be kept intact. The expense of start-up equipment for this technique is minimal.