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At least 343 records · Page 19Linked to original sources
PubMed2002

Ultrastructure of the secretion of prostasomes from benign and malignant epithelial cells in the prostate.

BACKGROUND: Prostate epithelial cells are producing, among other things, a fluid secretion containing small bodies, the prostasomes. The mechanism of synthesis of the prostasomes is not known in details, neither is it known whether the mode of prostasome production changes at a neoplastic transformation of the prostate cells. Due to the small size of the prostasomes, we have used electron microscopy for evaluating the production and distribution of prostasomes in benign and neoplastic cells of the prostate. METHODS: Benign and neoplastic areas in plastic embedded core biopsy specimens of prostate tissue were identified, and secreting cells were selected. The corresponding areas on the plastic blocks were further processed for examination in the electron microscope. RESULTS: The electron microscopical examination showed that the secretory machinery was similar in both types of tissue. Thus, in both benign and well-differentiated neoplastic cells studied, the formation of storage vesicles in the Golgi areas was similar, the content of the vesicles appeared similar, the structure and distribution of prostasomes were alike, and in both benign and malignant tissue, the secretion in the gland ducts showed the same appearance with many prostasomes. CONCLUSION: We conclude that cells in benign prostate tissue and cells in well-differentiated prostate carcinoma show great similarities in synthesis, storage, and release of prostasomes. However, this does not exclude the presence of other changes, for instance biochemical ones, in the prostasomes.

Adenocarcinoma↗
PubMed1975

[Comparative light and electron microscopic studies of oncocytic pituitary adenomas (author's transl)].

In a collection of 108 surgically removed, light and electron microscopically studied pituitary tumors, 19 adenomas (17.6%) could be found of which oncocytic tumor cells constituted more than 50%. These showed histologically, in conformity with the criteria of oncocytes, a fairly broad cytoplasm with finely granular or, in part, finely vacuolar structures and distinct cell membranes. The nuclei were predominantly round and moderately rich in chromatin but also in part, pyknotic. In paraffin-embedded sections the tumors could not be distinguished with certainty from chromophobe or moderately granulated acidophil adenomas. In plastic-embedded sections they could be identified by the typical filmy and finely granular feature of the cytoplasm which was distinctly different from conglomerations of secretory granules. Ultrastructurally they were characterized by many densely packed mitochondria. These were, in part, hydropically swollen. Furthermore, 5 tumors exhibited increased hormone-synthesizing organelles, 2 of which induced an acromegaly. Probably the oncocytic pituitary adenomas are secondarily transformed chromophobe or moderately chromophil tumors which must be regarded as independent, for the most part endocrinologically inactive pituitary tumors. In addition to these purely or almost purely oncocytic tumors further 12 adenomas (11.1%) with oncocytic parts constituting between 10 and 50% of the tissue were in our collection. Of these, 5 were moderately or distinctly acidophil adenomas with clinical symptoms of acromegaly; 2 were, for the most part, mucoid cell adenomas with Nelson's syndrome.

Acromegaly↗
PubMedDate not supplied

A rapid immunogold-silver staining for detection of bromodeoxyuridine in large numbers of plastic sections, using microwave irradiation.

A rapid and convenient method for the large scale, immunogold-silver staining (IGSS) of bromodeoxyuridine (BrdU) incorporated by S phase cells, by means of a monoclonal antibody (anti-BrdU) is described. Nineteen slides at a time can be incubated with the antibodies and the protein A-gold (PAG) in staining jars. The antibody and protein A-gold solutions could be used at least five times to incubate new batches of slides. The incubation times with these solutions were shortened by means of microwave irradiation. In this way 200 slides carrying at least 800 sections could be easily processed under the same conditions in one day, using 1.25 ml neat antibody solutions of anti-BrdU and rabbit anti-mouse. For light microscopy both plastic embedding systems: methylmethacrylate (MMA) and glycolmethacrylate (GMA) can be stained with this technique. The MMA sections, of which the plastic has to be removed before the IGSS, has the advantage of a stronger labelling intensity. The GMA plastic, which contains a cross-linking agent cannot be removed and consequently for GMA sections it is necessary to incubate the sections with a proteolytic enzyme (trypsin) before the IGSS, to reexpose the antigenic binding sides. However, the GMA sections can be allowed to air dry during the IGSS without negative effects on the morphology. This makes it possible to perform the antibody and the PAG-incubating steps on one day and to finish the IGSS the next day. In this way twice as many GMA slides can be incubated with the same antibody and PAG solutions than with MMA slides.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1980

A novel method to improve immunofluorescence in histological specimens.

A new approach to immunofluorescent labeling of sectioned tissue is described. Small tissue fragments which have been fixed and rendered permeable are labeled with immune reagents by either the direct or indirect method, prior to embedding in glycol methacrylate (2-hydroxyethyl methacrylate) at 4 degrees. In this way, the well-known superiority of plastic embedding over paraffin embedding or cryo-sections can be used to compare cellular structure in tissues with that seen in cultured cells.

Animals↗
PubMed1975

The demonstration of arylsulfatases with 4-nitro-1,2-benzenediol mono(hydrogen sulfate) by the formation of osmium blacks at the sites of copper capture.

A new method is described for the direct cytochemical demonstration of lysosomal arylsulfatases utilizing a synthetic substrate, 4-nitro-1,2-benzenediol mono(hydrogen sulfate), and a copper capture reaction. A small amount of Hatchett's brown (cupric ferrocyanide, Cu2Fe(CN)6-7 H2O) formed at the subcellular sites of copper capture is then utilized as a heterogeneous catalyst to effect the oxidative polymerization of 3,3'-diaminobenzidine which results in the formation of an insoluble, highly colored osmiophilic indamine polymer at the sites of enzymatic activity. The reaction product even at this stage prior to osmication is highly visible. It is readily seen with a light microscope in 50 mum sections of fixed tissues prepared with a mechanical chopper or in 10 micron cryostat sections treated for arylsulfatase activity. Upon osmication, an electron-opaque osmium black is formed which is much less soluble than the products of either the lead or barium capture reactions currently used for the demonstration of arylsulfatase with the electron microscope. The selection of areas of plastic-embedded tissues for ultrathin sectioning is facilitated by the ready visibility of these osmium black end products on 1-2 mum plastic sections which can be studied with the light microscope. This method gives permanent specimens demonstrating arylsulfatases A or B in lysosomes and autophagic vacuoles. In addition, enzyme activity is seen occasionally in the Golgi region or lamellae of certain cells believed to be elaborating sulfated products. In these instances, it may be demonstrating sulfotransferase activity.

Animals↗
PubMed1986

Demonstration of tartrate-resistant acid phosphatase in un-decalcified, glycolmethacrylate-embedded mouse bone: a possible marker for (pre)osteoclast identification.

Fixed, undecalcified mouse long bones were embedded in glycol methacrylate (GMA), sectioned, and incubated for acid phosphatase in the presence or absence of tartrate, to investigate the feasibility of tartrate-resistant acid phosphatase as a histochemical marker for osteoclast identification. Naphthol AS-BI phosphate was used as the substrate and hexazonium pararosanaline as coupler. Cytocentrifuge preparations of mouse, rat, and quail bone marrow or frozen and GMA sections of mouse splenic tissue were used as controls to specify acid phosphatase activity. After adequate fixation, acid phosphatase activity sensitive to tartrate inhibition (TS-AP) was demonstrated in macrophages from spleen, bone marrow, and loose connective tissue surrounding bone rudiments. Acid phosphatase activity resistant to tartrate inhibition (TR-AP), was detected in multi-nuclear osteoclasts and in some mononuclear cells from bone marrow and periosteum. In cytocentrifuge preparations and frozen sections of mouse spleen, TR-AP was demonstrated after simultaneous incubation with substrate and tartrate. In GMA sections, however, TR-AP could only be demonstrated after pre-incubation with tartrate before application of substrate. We suggest that histochemical demonstration of TR-AP versus TS-AP on GMA-embedded bone sections by means of a pre-incubation method can be used as an identification marker of (pre)osteoclasts. Plastic embedding is recommended for its excellent preservation of morphology and enzyme activity.

Acid Phosphatase↗
PubMed1992

Epon resin infiltration and immunogold labelling of pituitary secretory granules after cryofixation versus chemical fixation.

The degree of infiltration of epoxy resin into pituitary secretory granules was evaluated using X-ray microanalysis of the concentrations of chlorine in the epoxy resins. The effectiveness of infiltration was tested after three different tissue preparation techniques: cryofixation+freeze-drying (CF-FD), glutaraldehyde fixation (GF)+chemical dehydration, and no fixation--no dehydration. Signs of marked incomplete infiltration were found in embedded unfixed tissue while the other two techniques showed 80% infiltration. Uneven penetration was seen after CF-FD and GF. The plastic surface demonstrated a mountain-like appearance over the secretory granules after immunocytochemistry of the glutaraldehyde fixed tissue, whereas the CF-FD tissue showed a less furrowed surface. This probably is due to contact with water, which swells those parts of the granules that are unprotected by the plastic embedding medium. Our findings may explain why it is possible to perform immunocytochemistry on Epon embedded tissue.

Animals↗
PubMed1989

States of the art of immunoelectron microscopy in Japan.

In Japan, there are several laboratories which routinely utilize immunoelectron microscopy (IEM) for their investigation and participate in the development of methods for IEM. As a result, some major advances are in the making. IEM methods used in Japan may be divided roughly into four categories: 1) antibodies are reacted with tissues before the tissues are embedded in plastics (pre-embedding method); 2) antibodies are reacted with tissues after the tissues are embedded in plastics (post-embedding method); 3) tissues reacted with antibodies are deep-etched and the site of antigens are recognized in the replicas; and 4) that uses scanning electron microscopes. Samples from each category are introduced utilizing photographs provided by investigators, representing the states of the art of IEM in Japan.

Animals↗
PubMed1990

Immunolocalization in three dimensions: immunogold staining of cytoskeletal and nuclear matrix proteins in resinless electron microscopy sections.

We describe two methods for staining resinless thin sections with antibodies and gold-conjugated second antibodies. Immunolocalization of specific proteins is a powerful tool for cell structure studies but current techniques do not develop its full potential. Immunofluorescence provides only low-resolution localization, whereas conventional thin-section electron microscopy images and immunostains only the section surface. Resinless sections of extracted cell structures offer a simple and effective means of immuno-electron microscopy. Without embedding plastic or soluble proteins, the cell cytostructure produces high-contrast, three-dimensional images. Resinless sections of detergent-extracted cells are prepared by embedding in diethylene glycol distearate, sectioning, and removing diethylene glycol distearate before microscopy. In the first method of immunostaining, extracted cells were fixed and stained with antibodies before embedment, sectioning, removal of the embedding resin, and critical point drying. In the postembedment method, the sample was embedded and sectioned, the diethylene glycol distearate was removed, and the sample was rehydrated before antibody staining. With these techniques, specific proteins were localized with high resolution throughout the entire section. Stereoscopic micrographs of resinless sections revealed the precise localization of specific cytoskeleton and nuclear matrix proteins in three dimensions with unprecedented clarity.

Cell Line↗
PubMed1989

Utility of semithin sections in the diagnosis of donovanosis.

The relative merits of tissue smears, paraffin sections and semithin plastic embedded sections in the diagnosis of donovanosis were assessed. In three cases reported negative or doubtful for the organisms by the former two methods, semithin plastic sections provided definite diagnosis. The latter method revealed in addition the organisms in epidermis and perivascular locations. From amongst the three stains: toluidine blue, Leishman's and thionine azure II basic fuchsin, the last mentioned was found to be the method of choice for demonstrating the organisms differently from the host cells.

Calymmatobacterium↗
PubMed1997

Subsurface morphologic changes of ND:YAG laser-etched enamel.

BACKGROUND AND OBJECTIVE: Etching the enamel surface with a Nd:YAG dental laser produces impact craters with cavities, micropores, and microfissures. This in vitro SEM study examined laser-etched enamel to determine the pattern and extent of subsurface changes. STUDY DESIGN/MATERIALS AND METHODS: The facial surface of 10 maxillary central incisor teeth were coated with a black initiator and laser-etched with a pulsed Nd:YAG laser (1.06 lambda, 75 mJ, 15 Hz, 320 microns fiber, 94 J/cm2 fluence). The facial surface of five teeth were plastic-embedded under a low vacuum, then demineralized in 10% formic acid. The other teeth were split incisoapically. All samples were prepared for SEM. RESULTS: Examination of the plastic impressions showed a delicate interlacing pattern of thin partitions and small knob-like expansions. Examination of the split teeth showed the penetration of microfissures into the enamel estimated at 10 microns. CONCLUSION: These subsurface alterations may provide space for the infiltration and mechanical retention of dental resin.

Dental Enamel↗
PubMed1986

Immunohistochemical, enzyme histochemical, and immunologic features of giant lymph node hyperplasia of the hyaline-vascular type.

A combined histologic, immunohistologic, enzyme histochemical, and immunologic study has been carried out in a 7-year-old girl with recurring extramediastinal monocentric giant lymph node hyperplasia of hyaline-vascular type. A large panel of monoclonal and polyclonal antibodies to lymphoid and nonlymphoid cell markers were tested on frozen and paraffin-embedded lymph node tissue as well as on cell suspension and peripheral blood. Tissue enzyme histochemical study, including a conventional hematologic panel, was performed on frozen and plastic-embedded sections. The pattern was dominated by nodular aggregates of round BA-1+ Leu-14+ HLA-DR+ ATPase+ lymphocytes with polyclonal sIgD and sIgM positivity and lacking cIg and BA-2 staining. Leu-1+/Leu-4+, OKT6+, OKT10+, Leu-7+, and CALLA+ cells were few or absent in the nodules, whereas DRC-1+ BA-2+ HLA-DR+ 5'-Nuc+ cells formed a dendritic network in the outer portion of the nodules. No immunoreactivity for lymphoid and nonlymphoid cell markers, including cytokeratin and keratin, was detected in centrinodular histiocytic-like cells. Particularly, the Hassall's-like structures contained a target-like positivity for laminin, and consisted of flattened acid phosphatase (AP), alpha-naphthyl acetate esterase (ANAE), 5'-nucleotidase (5'-Nuc), and adenosine triphosphatase (ATPase) positive cells, whose enzyme profile overlapped with that of the histiocytic-like cells. The extranodular areas were mainly composed of Leu-1+/Leu-4+ lymphocytes with Leu-3a+/OKT4+ phenotype and, to a lesser extent, of OKT6+ OKT10+ lymphoid cells and scattered cells with markers of histiocytic lineage. The abundant vascular component was generally identified by laminin positivity and, in smaller proportion, it was positive for Factor VIII-related antigen. Most of the medium-sized vessels with high endothelium had marked AP, ANAE, and ATPase activities. The process observed resulted from vascularized nodular aggregates of nontransformed B-cells with the phenotype of primary follicle lymphocytes, associated to centrinodular histiocytic-like cells with a distinct enzyme profile.

Antibodies, Monoclonal↗
PubMed1985

Uptake of tritiated phosphatidylcholine by isolated rat liver nuclei studied by electron microscope autoradiography in albumin embedded specimens.

The transfer of phosphatidylcholine from multilamellar vesicles to isolated rat liver nuclei was studied by means of electron microscope autoradiography. To avoid the possible loss or the artifactual redistribution of the phospholipid occurring during dehydration with organic solvents and plastic embedding, the fixed specimens were embedded in aqueous albumin, which was then hardened by glutaraldehyde and dehydrated physically. The quantitative analyses of the autoradiograms demonstrated that part of the labelled phosphatidylcholine was taken up by the isolated nuclei and was transferred inside the nucleoplasm. The uptake corresponded to the loss of the vesicular arrangement, probably owing to the formation of a lipoprotein complex with the nuclear proteins. The results provide evidence that the lipid-induced changes of transcriptional activity occur upon the actual interaction of the exogenous phospholipid with the inner nuclear components.

Albumins↗
PubMed1989

Morphology of atopic eczema.

The routine examination of skin biopsy specimens embedded in paraffin and strained with hematoxylin-eosin has failed to allow differentiation of atopic eczema from other types of eczematous dermatitis. The use of 1-micron plastic-embedded sections permits the recognition of infiltrating cell types and blood vessel alterations, thus allowing a refined method to examine cutaneous lesions and permit better definition of cutaneous structures than can be achieved in routinely-processed specimens. Acute vesicular lesions exhibited marked epidermal intercellular edema (spongiosis) and a dermal inflammatory infiltrate of lymphocytes, and activated lymphocytes with normal numbers of mast cells that exhibited various degrees of hypogranulation. Only rare eosinophils, neutrophils, and basophils were noted. Venular alterations included endothelial cell hypertrophy without necrosis. In lichenified plaques there was epidermal hyperplasia with a dermal inflammatory infiltrate that included increased numbers of fully granulated mast cells and increased numbers of lymphocytes and monocyte-macrophages. Alterations of venules included marked endothelial cell hypertrophy and basement membrane thickening. Cutaneous nerves exhibited demyelination and fibrosis. Also, increased numbers of Langerhans' cells have been noted in the epidermis of chronic lesions. Despite the absence of eosinophils, major basic protein has been demonstrated in the dermis by direct immunofluorescence techniques. Studies of lymphocyte subsets have shown increased numbers of CD4+ T lymphocytes.

Adult↗
PubMed1989

Immunoelectron microscopic identification of human AA-type amyloid: exploration of various monoclonal AA-antibodies, methods of fixation, embedding and of other parameters for the protein-A gold method.

Using the postembedding protein-A gold technique ten monoclonal antibodies directed against amyloid-A protein (AA) were examined by immunoelectron microscopy to identify amyloid-A (AA) amyloid fibrils in plastic-embedded renal tissue of five patients and two controls. Two monoclonal antibodies (mc1, mc20) specifically labeled these amyloid deposits; two additional ones (mc4, mc13) bound with an intermediate rabbit anti-mouse IgG antiserum. These monoclonal anti-AA antibodies clearly separate amyloid fibrils from morphologically similar fibrils in the vicinity. Employing varying embedding media, fixation techniques, as well as etching and staining protocols, we adapted this method for the immunoelectron microscopic identification of AA-type amyloid fibrils and for the antigenic diagnosis of AA-type amyloid on routinely processed ultrathin sections.

Amyloidosis↗
PubMed1985

How the fixation-embedding protocol affects the specificity and efficiency of immunocytochemical stains for gonadotropin subunits.

This report describes a study designed to test factors that may affect the efficiency and specificity of stains for gonadotropins. These include chemical or freeze-fixation and dehydration, heat polymerization of the plastic embedding compound, dehydration in organic solvents, and etching. Specifically, postembedding stains for LH or FSH subunits were applied to 1-micron sections of 1) Araldite-embedded pituitaries that were either chemically fixed and dehydrated or freeze-fixed and freeze-dried; 2) Aldehyde-fixed pituitaries that were dehydrated in water-soluble glycol methacrylate (GMA) and embedded in GMA at 4 degrees C; and 3) p-formaldehyde-fixed pituitaries that were embedded in paraffin. A fourth group of pituitaries was dispersed and grown in monolayers for 1-3 days. These were stained following glutaraldehyde fixation. The optimal dilution of the primary antisera varied with the protocol; however, the percentage of cells staining for beta subunits did not change. In contrast, postembedding stains showed that alpha subunit reactivity is masked or destroyed in pituitaries that are fixed in glutaraldehyde and embedded in Araldite. Alpha chain reactivity was detected (in 14% of cells) either after freeze-fixation and freeze-drying followed by Araldite embedding, or after 4% paraformaldehyde fixation and GMA embedding (in 17% of cells). Staining in paraffin-embedded pituitaries was seen in only 10% of the cells. Preembedding stains for alpha chains were strikingly sensitive, however, and immunoreactivity was seen in 18-26% of the population of monolayer cells. Thus, whereas the percentages of cells staining for beta subunits do not change following the use of most of the fixation and embedding protocols, alpha chain reactivity is destroyed by all but the mildest. These findings show that one can control or improve the specificity of the stains for LH and FSH by the fixation-embedding protocol.

Animals↗
PubMed1981

High resolution light microscopy in renal pathology.

Seven hundred renal specimens embedded in epoxy resins and stained with polychromatic stains were compared with paraffin sections stained with Hematoxylin and Eosin (H & E), Perodic and Schiff, (PAS), silver, and trichrome stains. High resolution of light microscopy, never in wax histopathology, may be obtained by the use of plastic embedding and polychromatic stains. Cell boundaries, intracellular organelles, basement membranes, different cellular types, apposition of different substances, and other pathologic changes were readily recognized in a single P + P (Plastic section stained with Polychromatic stains) section, whereas paraffin sections usually needed special stains. The same plastic block may be used for transmission electron microscopy. Slightly elevated cost, special training of the technician and pathologist, and some few remaining technical difficulties are the disadvantages of this method. High resolution light microscopy methods are recommended for routine renal biopsies.

Basement Membrane↗