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PubMed1986

Immunohistochemical demonstration of DNA-incorporated 5-bromodeoxyuridine in frozen and plastic embedded sections.

The application of an immunohistochemical method in the detection of replicating cells, that have incorporated 5-bromodeoxyuridine (BrdUrd), was studied on frozen and plastic embedded sections of different rat tissues. Hydrolysis conditions employed in the Feulgen procedure are essential in making the incorporated BrdUrd accessible to the monoclonal anti-BrdUrd antibodies. To demonstrate the incorporated BrdUrd in plastic embedded sections a subsequent etching with xylene and digestion with protease is necessary. Data obtained with this method are completely comparable with those found by the tritiated thymidine method. In comparison with the thymidine method, the BrdUrd method is much less time consuming and does not require precautions in working with radioactivity. The BrdUrd-method enables a more precise localization as is especially shown in the plastic embedded sections.

Animals↗
PubMed1985

A comparison of subcellular element concentrations in frozen-dried, plastic-embedded, dry-cut sections and frozen-dried cryosections.

Biological X-ray microanalysis of diffusible elements within cellular and subcellular compartments requires preparation methods to retain electrolytes in the compartments they occupied in vivo. X-ray microanalysis of frozen-dried, plastic-embedded samples has been used to quantitate electrolytes at the cellular level. We have compared the subcellular elemental distribution in dry cut sections from such samples with that in ultrathin frozen-dried cryosections. Rat pancreases were quench-frozen onto a helium-vapor-cooled copper block. Cryosections were cut at 130-150 K, transferred using a Gatan cold stage, frozen-dried in the column and analysed at 190 K. Tissue fragments were frozen-dried at 190 K, and cut on a dry knife at 293 K. Both samples provided images permitting unambiguous identification of all major compartments except the Golgi complex. Intracellular potassium-to-sodium ratios obtained on frozen-dried plastic-embedded sections were lower than for cryosections (e.g. 1.77 in basal cytoplasm in plastic sections as compared to 4.34 for cryosections) and varied with the pre-embedding procedure (e.g. 1.77 in formaldehyde-fixed as compared to 2.87 in osmium-fixed plastic sections). Potassium gradients between adjacent organelles were large in cryosections and insignificant in plastic-embedded material. Higher cytoplasmic phosphorus, potassium and sulfur concentrations were observed in cryosections. Therefore, a redistribution of electrolytes and covalently bound elements occurred subcellularly in the plastic sections. Calcium was quantifiable in most organelles in cryosections but the plastic lowered sensitivity too much to permit routine calcium quantification. We conclude that in our hands frozen-dried, plastic-embedded samples were compromised and provided lower sensitivity than cryosections.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

Plastic-embedded semi-thin sections of fine needle aspiration biopsies with dibasic staining. Diagnostic and didactic applications.

The diagnostic and didactic utility of plastic-embedded semi-thin sections of fine needle aspiration biopsies is presented using a case-study approach. The Spurr epoxy semi-thin sections were stained with a newly developed sequential basic fuchsin-methylene blue stain, which gives hematoxylin-and-eosin-like staining and simultaneously substitutes for a wide variety of special stains. The informational content of the sections can approach that of electron microscopy. The use of a direct off-the-slide "pop-off" technique in preparing the plastic-embedded sections allows for a direct comparison between similar groups of cells embedded in plastic and present on the routine aspiration slides; retrospective analysis can discern subtle, previously unrecognized morphologic features in the alcohol-fixed, Papanicolaou-stained slides. The limitations of this comparative approach, however, become manifest when the effects of alcohol fixation on cells are directly compared in plastic and at the ultrastructural level to aldehyde fixation.

Adenoma↗
PubMed1984

Spontaneous autoradiographic grain activation associated with mast cells in methacrylate plastic embedded tissue sections.

Autoradiographic tracing using tritium labeled compounds or cells is a common laboratory technique for light and electron microscopy. This report describes a chemographic effect associated with certain cells in sections from tissues embedded in the new methacrylate plastic embedding compounds. When tissue sections from rats and rhesus monkeys that received no radioisotope were coated with nuclear track emulsion and subsequently developed, cells with morphologic characteristics of mast cells showed significant grain formation over the entire cell. Three different types of methacrylate plastics were tested using rat and monkey tissues and all three were found to promote grain formation over mast cells; however, this phenomenon was not seen in similar tissue sections from paraffin or epoxy embedded material. The properties of methacrylate plastics which promote positive chemography by mast cells may reflect the greater permeability of this class of plastics. Due to their wide tissue distribution, the presence of such chemographically active cells could cause false estimates of the distribution of either exogenous radiolabeled cells or radioisotopes within many tissues.

Animals↗
PubMed1982

Classification of plastic-embedded rat seminiferous epithelium prior to electron microscopy.

Systematic electron microscopic studies of the changes which take place during the cycle of the rat seminiferous epithelium require that each of the 14 stages of the cycle are identified in the light microscope in plastic-embedded material allowing each stage to be trimmed out separately before the electron microscopic study. The classification of the 14 stages has originally been based on the morphological characteristics seen in paraffin-embedded tissue after PAS-staining. PAS-staining is less effective in plastic-embedded material, and this may be a main reason why electron microscopic findings of the seminiferous epithelium relatively seldom are related to the stages of the cycle. In the present paper a method is described by which the 14 stages of the cycle can be easily identified in the light microscope in plastic-embedded tissue. Some of the stages could be subdivided and a total of 23 stages were distinguished. This constitutes a safe method allowing accurate classification prior to electron microscopic examination of the seminiferous epithelium.

Animals↗
PubMed1988

Antigen localization in immunoperoxidase-stained plastic-embedded soft tissues.

Immunoperoxidase stains were performed on normal and neoplastic tissue from prostate, colon, thyroid, lung, nerve, uterus, and placenta embedded in both plastic (glycolmethacrylate [GMA]) and paraffin. Positive results in plastic section were obtained for carcinoembryonic antigen (CEA), keratin, epithelial membrane antigen (EMA), thyroglobulins, S-100, prostate-specific antigen, human chorionic gonadotrophin (HCG), and beta-HCG. More delicate staining with more precise localization of antigens is noted. Superior (paraformaldehyde) fixation and cold processing followed by GMA polymerization (4 degrees C) allow for optimum antigen survival. After fixation, tissue processing involves a series of 0.1 mol/L phosphate buffer rinses with sucrose and ammonium chloride in a conventional dip-and-dunk processor placed in a 4 degrees C cold room. Acetone dehydrations are used before GMA infiltration, cold polymerization, and sectioning. Before immunoperoxidase staining, the plastic section is digested in .25% bovine trypsin for ten minutes. The immunoperoxidase methods described can be useful when small biopsies are routinely embedded in plastic to obtain improved histologic (hematoxylin-eosin) sections. There may also be research applications in quantifying antigen expression in benign, dysplastic, and neoplastic tissues by examining the stains under high power.

Adenocarcinoma↗
PubMed1982

Plastic embedding of cutaneous specimens: an important diagnostic aid in mycosis fungoides.

A technique for primary plastic embedding for light microscopy was utilized in evaluating plaque lesions in four patients with mycosis fungoides and compared to tissues from the same patients embedded in paraffin. Standard 3 mm punch biopsies were utilized. Specimens were fixed in B-5 and embedded in araldite epoxy resin. In specimens from all four patients, the cytological details of the mycosis cells were superior in the plastic embedded tissues. this practical and relatively inexpensive method may prove to be a sensitive indicator of mycosis cells in early lesions. This technique also permits the use of a variety of special stains, immunoperoxidase and electron microscopic analyses.

Aged↗
PubMed1991

Immunohistochemical localization and quantification of desmoplakins I & II and keratins 1 and 19 in plastic-embedded sections of human gingiva.

We developed immunohistochemical and image analytical techniques to localize and quantify keratins and desmoplakins in sections of plastic-embedded human gingiva. Acetone fixation followed by plastic embedding of gingiva provided excellent morphology and permitted immunohistochemical detection of keratins 1 and 19 and desmoplakins I & II after 2.5-min trypsin digestion. Quantitative image analysis demonstrated that different volume densities of staining of each marker were associated with specific epithelial strata. Keratin 1 stained most heavily in granular strata, followed by corneal and spinous strata; keratin 19 stained most strongly in the basal layer; desmoplakins I & II stained most strongly in the granular and corneal strata. These findings confirm that variations of keratin and desmoplakin expression in these epithelial are associated with regional patterns of epithelial differentiation.

Cell Differentiation↗
PubMed1991

Enzyme, lectin and immunohistochemistry of plastic embedded undecalcified bone and other hard tissues for light microscopic investigations.

Enzymes and tissue antigens were localized on plastic embedded undecalcified bones and teeth using Technovit 7200 VLC (Kulzer, Germany). This resin is hard enough for cutting and grinding procedures on rotating plates with diamond layers. The pores between the diamond grains are not obstructed with this resin. The procedure described here permits localization of antigens in the soft tissues adjacent to, or in the biological hard tissues themselves and in dental implants (ceramic or metallic) on the light microscopic level. The undecalcified bone is fixed and embedded in plastic and cut at 100-150 microns. The slices are ground automatically by a grinding machine to a thickness of 5-10 microns. After application of the substrates for alkaline and acid phosphatases and the required dyes, the distribution of these enzymes can be demonstrated. Tissue antigens also can be detected with slightly modified standard techniques of immunohistochemistry and lectin histochemistry using the peroxidase technique or fluorescence microscopy.

Ameloblasts↗
PubMed1985

Comparative study of three methods of plastic embedding in diagnostic dermatopathology.

Three methods of plastic embedding were assessed for their value in routine dermatopathology. The J B 4, Taab embedding, and Taab transmit techniques were compared for quality, convenience, and safety. The Taab transmit method was the most satisfactory method, being both rapid and simple. An additional advantage is that the resin can be removed and the immunoperoxidase technique carried out on thin sections.

Histological Techniques↗
PubMed1992

A plastic embedding technique for analyzing fluorescent dextran-amine labelled neuronal profiles.

A plastic embedding technique employing fluorescently labelled dextran-amines is described. After application of tracer to cut nerves and appropriate transport time, animals were fixed in paraformaldehyde. Subsequently their brains were dissected, heads and brains were dehydrated, embedded in methacrylate and sectioned serially on a rotary microtome. Plastic sections allow high resolution of single neuron profiles and complete serial reconstruction of undistorted sections, including embryos with large amounts of yolk. In conjunction with whole mount analysis and double labelling, this technique can accurately reveal the spatial relationships of nerve components throughout development.

Ambystoma mexicanum↗
PubMed1981

Plastic-embedded human marrow biopsy specimens: improved histochemical methods.

Improved methods for processing, sectioning, and staining plastic (glycol methacrylate)-embedded human marrow biopsy specimens were studied. Special stains, including naphthol AS-D-chloro-acetate esterase, PAS, reticulin, and iron, have been modified so that they are suitable for undecalcified, 2-microns-thick, plastic-embedded human marrow biopsy specimens. These adaptations permit plastic-embedded marrow specimens to be used for clinical diagnosis. Marrow biopsy specimens embedded in plastic were compared with biopsy specimens preserved by the conventional paraffin method. The plastic-embedded marrows provide better results from morphologic examination (enhancing diagnostic accuracy), permit assessment of bone as well as of marrow, and allow histochemical analysis to be performed.

Anemia, Aplastic↗
PubMed1985

Plastic embedding in routine histology. I: Preparation of semi-thin sections of undecalcified marrow cores.

The preparation of sections of bone marrow cores in a routine histology laboratory requires decalcification and paraffin embedding, which produces shrinkage and considerable loss of cellular detail. This may be avoided by using plastic embedding procedures. This report describes a simplified routine procedure for using methylmethacrylate as a plastic embedding medium for the preparation of semi-thin sections of undecalcified bone marrow cores. A modification of the May-Grunwald-Giemsa stain is also given which provides good colour differentiation of various haematopoietic cells in the marrow. The method is simple, reproducible, requires no expensive equipment, and is suitable for routine processing of bone marrow biopsy cores in any histopathology laboratory.

Bone Marrow Examination↗
PubMed1980

[Rational simplified plastic embedding with polymethacrylate for non-decalcified bone sections].

A exact judgment of bone and bone marrow tissue is based on an undecalcified treatment technique by means of plastics embedding and hard section microtomy. All hitherto existing routine techniques of plastics embedding of bone tissue used monomeres of methakrylate with addition of so-called emollient substances for polymerisation. Disadvantages of a stronger shrinking of the polymerisation product and uncontrolled, not always avoidable accelerations of the polymerisation process which have an essentially negative influence on the histological results should thus be avoided. A very exact observance of the treatment steps is here necessary. In the further development of our embedding method we turned to the polymethacrylates. The polymerisation adhesive Kalloplast R used in industry proved as the most suitable initial substance for the new method. The yielded results lie in a considerable shortening and further simplification of the embedding technique. The results are always well reproducible. Undesirable shrinking or polymerisation artefacts with impairment of the histological results do no more appear.

Bone and Bones↗
PubMed1987

Plastic embedding evaluation of Pneumocystis carinii pneumonia in AIDS. Simultaneous demonstration of cyst and sporozoite forms.

To study the possible role of plastic embedding in the surgical pathologic diagnosis of Pneumocystis carinii pneumonia, bronchial biopsy specimens from five patients with AIDS were examined using 0.9 micron thick methacrylate sections stained with silver methenamine borate and counterstained with toluidine blue. This technique was found to be superior to paraffin embedding in the demonstration of the fine structural details of both Pneumocystis and the surrounding lung tissue. This method permitted the simultaneous demonstration of both the cyst wall and intracystic sporozoites of Pneumocystis in biopsy tissue, which had been previously possible only by using electron microscopy. This technique assists in the differentiation of Pneumocystis from other opportunistic agents, and may be useful in estimating the relative numbers of cyst and sporozoite forms of the organism. We recommend that bronchoscopic and open lung biopsies from AIDS patients suspected of having Pneumocystis pneumonia be submitted for plastic embedding and high-resolution light microscopy.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Simultaneous immunohistochemical demonstration of antigen expression and 5-bromodeoxyuridine incorporation in plastic embedded sections.

In this study a double immunohistochemical staining procedure is described for the simultaneous demonstration of antigen expressing cells and replicating cells in rat thymus. As markers for cell surface antigen expression a monoclonal antibody against Ia-expressing cells (His 19) and a monoclonal antibody against cells of the monocyte-macrophage lineage (ED2) were used. Replicating cells were demonstrated by the incorporation of 5-bromodeoxyuridine (BrdUrd). Tissue pieces were fixed in a periodate-lysine-paraformaldehyde fixative and embedded in glycol methacrylate. To demonstrate Ia-expressing cells or ED2-positive macrophages in plastic embedded sections a digestion with trypsin is necessary. The staining procedure was applied sequentially and was performed with a peroxidase and an alkaline phosphatase labeled reagent yielding respectively a brown and a blue reaction product. Results with this staining procedure on plastic embedded sections of rat thymus, an organ with a high DNA synthesizing capacity, showed incorporation of BrdUrd predominantly in the cortex. ED2-positive macrophages were only found in the cortex. The Ia-positive epithelial reticular cells demonstrated extremely well their stellate form.

Animals↗
PubMedDate not supplied

Polyomavirus infection versus high-grade bladder carcinoma. The importance of cytologic and comparative morphometric studies of plastic-embedded voided urine sediments.

The cytodiagnostic criteria of polyomavirus infection of the urinary tract versus high-grade bladder carcinoma in Cytospin and plastic-embedded preparations of voided urine samples are presented. In Cytospin preparations, the polyomavirus infection and the high-grade bladder carcinoma could not always be distinguished from each other. The diagnosis was facilitated when plastic-embedded specimens were used for cytologic study. On the basis of the comparison of morphometric data from the two types of specimens, it is postulated that the physical properties of the cancer cell nuclei differ from those of the virocytes.

Carcinoma↗
PubMed1992

Adaptations of Goldner's Masson trichrome stain for the study of undecalcified plastic embedded bone.

Specialized adaptations for application of Goldner's Masson trichrome stain to plastic embedded undecalcified bone specimens are presented. This stain can be used successfully on methyl-glycol methacrylate, glycol methacrylate and Spurr embedded bones. The stain affords the advantage of good cellular staining due to the hematoxylin component with concomitant sharp discrimination of mature bone matrix which stains green, immature new bone matrix which stains red, and calcified cartilage which stains very pale green. Use of red filters during photomicrography aids in bone-osteoid discrimination in black and white photographs.

Azo Compounds↗