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  • 1
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Scandinavian journal of immunology 26 (1987), S. 0 
    ISSN: 1365-3083
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Two non-lymphoid cell types play an important role in the pathogenesis of arthritis, i.e. the ‘classical’ macrophage and the antigen-presenting dendritic cell [33]. In the present sludy, the roles of both cell types are studied in antigen-induced arthritis of the rat knee joint. Cryostat sections of whole, unfixed, undecalcified knee joints were used for immunohistochemical staining of non-lymphoid cells and lymphocyte subsets. For the demonstration of the different types of non-lymphoid cells, monoclonal antibodies against rat macrophages (ED1. ED2, and ED3) and against Ia antigen were used with an immunoperoxidase method. The results show in an overalls view of the arthritic joint the different sites of action of the classical macrophages on the one hand and the Ia-positive dendritic cells on the other. Classical macrophages were mainly found in the superficial layers of the synovium bordering joint space and articular cartilage. Dendritic cells and T cells of the helper phenotype were mainly found in clusters surrounding small blood vessels within the synovium. These clusters express the immunological background of the antigen-induced arthritis and may well be responsible for the continuation of the arthritic process.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-0827
    Keywords: Ectopic cartilage formation ; Chondrocyte ; Differentiation ; Pancreatic cancer ; Mincralization ; Nude mice
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract Mineralized as well as nonmineralized cartilage-like structures enclosing cells resembling chondrocytes were found in human-derived undifferentiated but not in poorly differentiated pancreatic adenocarcinoma explants grown in nude mice. The structures reacted with anti-mouse IgG but not with antibodies against human cytokeratin 19, indicating that the newly formed tissue was of mouse origin. High activity of alkaline phosphatase was found in cell layers surrounding the structures and in cells embedded in the matrix. The extracellular matrix was strongly positive after Sirius red staining, reacted with anti-collagen type II antibodies, and the presence of proteoglycans was demonstrated with Alcian blue staining and by metachromasia after Giemsa staining. Electron microscopic inspection revealed the presence of bundles of both thick collagenous fibrils with low levels of fine filamentous material and thin collagenous fibrils with high concentrations of filamentous components. The majority of both types of matrices was found to be partially or completely calcified. The mean area density of the cartilage-like structures in the undifferentiated tumors was 0.31%. The frequent formation of the cartilage-like structures in the rapidly growing undifferentiated explants and its absence in the slowly growing, more differentiated explants suggest that low oxygen tensions in combination with altered levels of growth factors, such as members of the transforming growth factor β superfamily, create conditions that induce differentiation of fibroblasts to chondrocytes. It is concluded that these human tumors grown in nude mice can be used as an in vivo model to study ectopic formation of mineralized cartilage.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The use of unfixed and undecalcified cryostat sections of mouse knee joints is described for the study of enzyme histochemical reactions. Non-inflamed knee joints and knee joints of mice with antigen induced arthritis have been used. Joints were embedded in gelatin and subsequently cut at low speed with a motor-driven cryostat fitted with a tungsten carbide knife at an obtuse angle (10°). The sections were attached to transparent tape to keep the integrity of the tissue intact. The following histochemical reactions were carried out succesfully: the tetrazolium salt reaction for dehydrogenase and reductase activity, the post-azocoupling method for acid phosphatase and cathepsin B activity and the simultaneous azo-coupling method for esterase activity. In all cases the morphology and integrity of the sections were well kept and serial sections were obtained without any difficulty. Nonspecific staining of the tape did not occur. The localization of the final reaction product was meeting criteria for specific and precise histochemical methods with the exception of the metal salt method because of nonspecific staining of undecalcified bone. Cytophotometry of the final reaction product appeared to be reproducible and valid as demonstrated by reaction for glucose-6-phosphate dehydrogenase activity in synoviocytes from knee joints with induced arthritis. End point measurements as well as kinetic measurements of the formazan production were performed and linear relationships were found between the specific formazan formation and section thickness or incubation time, respectively. It is concluded that cryostat sections attached to transparent tape are an excellent tool for the study of the metabolism in tissues adjacent to bone matrix. Changes of enzyme activities in synoviocytes, chondrocytes and osteoclasts during induced arthritis are discussed.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Cytochemical methods for the demonstration of enzyme activities in blood and bone marrow cells were systematically improved by the addition of an inert polymer, polyvinyl alcohol (PVA), to the incubation medium and by using optimized reaction media. The methods investigated were tetrazolium salt methods for lactate, glucose-6-phosphate, succinate and glutamate dehydrogenase, the indoxyl-tetrazolium salt method for alkaline phosphatase, the diaminobenzidine method for peroxidase, and diazonium salt methods for chloroacetate esterase, β-glucosaminidase, β-glucuronidase, acid phosphatase, and dipeptidylpeptidase II and IV. PVA in the media preserved the morphology of cells very well and prevented leakage of large molecules such as enzymes from the cells. Therefore, fixation or long periods of air-drying prior to incubation leading to substantial loss of enzyme activity could be avoided. A brief period of drying (2 min at 37° C) of the cell preparations just before the incubation was sufficient for making the cells permeable. Localization of enzyme activities was very precise and precipitation of the final reaction product was confined to sites which are known to contain the enzyme under study (granules, mitochondria, lysosomes). These advantages advocate the use of PVA in haematological enzyme cytochemistry and especially for diagnosis of leukemia.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A new method for enzyme cytochemical studies on individual cells is developed. Cells are incorporated in the matrix of a thin film of transparent polyacrylamide prior to incubation in a cytochemical medium. Five different kinds of individual cells, i.e. isolated rat hepatocytes, isolated mouse oocytes, cultivated human fibroblasts, rat thymocytes and human blood cells are used for testing the applicability of this method for the cytochemical demonstration of glucose-6-phosphate dehydrogenase with tetranitro BT. The incorporation technique solves at least some of the problems occurring with enzyme cytochemistry on single cells. The morphology of the cells is very well preserved, the formazan precipitation due to enzyme activity occurs entirely within the cell cytoplasm, the nothing dehydrogenase activity can be kept very low and the loss of cells is completely prevented with all cell types used.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A sensitive cytochemical staining method for glucose-6-phosphate dehydrogenase activity in individual human erythrocytes is described. This staining method can be used for the rapid routine discrimination of patients with a deficiency of the enzyme in its homozygote or heterozygote form, but also for quantitative localization of its activity in individual erythrocytes. The staining procedure in its optimal form consists of a treatment of the erythrocytes with sodium nitrite, then a “fixation” in 0.025% glutaraldehyde (under NADP+ protection of the active site of the enzyme), followed by incubation of the cells in suspension in the presence of tetranitro BT, 1-methoxyphenazine methosulphate and polyvinyl alcohol. Using this new technique, a sharp localization is obtained of the glucose-6-phosphate dehydrogenase activity, which enables discrimination between red cells with different levels of enzyme activity, as a consequence of enzyme deficiencies or age changes.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Following the clamping of the afferent vessels of the left lateral and median lobes in rat liver, a considerable part of these lobes show signs of necrosis 24 h after 90 min of ischemia, wheras no necrotic areas can be detected after 30 min interruption of the blood flow. The purpose of this study was to examine the value of an analysis of the leakage of enzymes from the liver parenchyma in the early phase after restoration of the blood flow after ichemia for a prediction of the occurrence of necrosis. Leakage of the enzymes GPT, GOT and LDH can be detected in the blood plasma with a maximum activity between 1 and 5 h both following 30 and 90 min of ischemia; a considerable difference in clearance is observed, however, in the period afterwards, the normal situation being reached after 24 h with the 30-min ischemic period, but not following the 90-min period. With use of an enzyme histochemical reaction, in situ a depletion of LDH-activity in the hepatocytes could be detected within a short period of time after 30 min temporary ischemia and a restoration during the following period of 24 h; the decrease in LDH-activity persisted during 24 h with a 90-min period of ischemia. Electronmicroscopically cytoplasmic blebs arosen from hepatocytes are observed in the lumen of sinusoids immediately after 30 min of ischemia, whereas after 90 min of ischemia actual leakage of cytoplasmic material takes place through the damaged surface of the hepatocytes. Enzyme leakage probably takes place via these both types of shedding of cytoplasm. It is concluded that the enzyme leakage as such cannot be used as a discriminating test between reversible and irreversible damage of the liver parenchyma.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular histology 21 (1989), S. 373-379 
    ISSN: 1573-6865
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular histology 16 (1984), S. 799-803 
    ISSN: 1573-6865
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
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