1,721,042 research outputs found
Some histochemical observations on Gaucher cells.
No full textPlastic-embedded bone marrow biopsies from four patients with Gaucher's disease have been studied histochemically. Concanavalin A (ConA) was found to bind to cytoplasmic inclusions of Gaucher cells; the binding was prevented by lipid extraction or beta-glucosidase digestion. This suggests that glucocerebrosides stored in Gaucher cells are responsible for ConA binding; ConA staining combined with lipid extraction and beta-glucosidase digestion tests may be taken as a tool for the demonstration of Gaucher's cerebrosides of possible practical importance in diagnosis and investigation of Gaucher's disease. An excess of vic-glycol groups with respect to ConA binding-sugar residues and not extractable by lipid solvents are demonstrable in Gaucher cells. Vic-glycols appear to be regularly arranged at the electron microscopy level within Gaucher cell lysosomes along typical Gaucher "tubules", where some kind of interaction between lipid and protein should occur. Acid phosphatase might be one protein species involved in such interactio
Endosteal surfaces in hyperparathyroidism: an enzyme cytochemical study on low-temperature-processed, glycol-methacrylate-embedded bone biopsies.
No full textAlkaline phosphatase (AlP) and tartrate-resistant acid phosphatase (TRAP) activities have been studied comparatively in needle biopsies of the iliac crest of four cases of secondary hyperparathyroidism (renal osteodystrophy). AlP activity was associated with the plasma membrane of osteoblasts and their processes, of reticular cells of bone marrow and of young osteocytes of osteoid borders and woven bone. Moreover, it was detected in the fibroblast-like cells of the endosteal "fibrosis". These cells were orderly in arrangement and were parallel to the endosteal surfaces near zones of bone formation. They were disorderly near zones of bone resorption. A strong TRAP-positive reaction was present in osteoclasts and mononuclear cells of endosteal "fibrosis" and in osteocytes located near active osteoclasts and in woven bone. These results suggest that the so-called fibrosis of hyperparathyroidism, rather than representing reparative, inert tissue, consists of osteoblast-like cells, probably precursors of osteoblasts derived by parathormone-stimulated proliferation of AlP-positive stromal cells of bone marrow, and of TRAP-positive, mononuclear cells, probably preosteoclasts. Moreover, they show that TRAP activity can be present in osteocytes, probably under stimulation by the same factors which stimulate osteoclast activity. The histochemical demonstration of AlP and TRAP facilitates the morphological diagnosis of metabolic bone disease and may improve knowledge of bone physiopathology
Tartrate-resistant acid phosphatase activity in rat osteoblasts and osteocytes.
No full textOsteonectin was immunolocalized in human fetal and calf neonatal developing bone using newly developed monoclonal antibodies. The protein was localized to the cytoplasm of osteoblasts and young osteocytes. In bone matrix, strong reactivity was found in newly laid down osteoid. Bone matrix immunoreactivity was enhanced by pretreatment of sections with proteases, possibly because of an unmasking of epitopes engaged in protein-protein interactions. Osteonectin immunoreactivity was also found in preosteoblasts in all types of human fetal osteogenesis (membranous, endochondral, subperiosteal, and mantellar (Meckel's cartilage) ossification), and in some chondrocytes of metaphyseal growth plate, possibly modulating towards an osteoblastic phenotype
Basic and 'special' stains for plastic sections in bone marrow histopathology, with special reference to May-Grünwald Giemsa and enzyme histochemistry.
No full textA battery of morphological, histochemical, and enzyme histochemical stains have been experimented on semithin sections of glycol-methacrylate-embedded bone marrow biopsies. We have been able to reproduce on sections the typical 'Romanowsky effect' which characterizes May-Grünwald Giemsa-stained smears of bone marrow or peripheral blood. This appears to be of critical importance for proper routine morphological evaluation of bone marrow biopsies. Conventional histochemical stains, and the enzyme histochemistry reactions that are most useful and widely used in the study of marrow aspiration smears have been successfully applied to plastic sections: in this way the evaluation of the cytochemical profiles of marrow diseases, especially leukemias, may be included in the histopathologist's diagnostic approach, with the additional advantage of preserving the architecture of the tissue and the relationship between haemapoietic cells and stromal component
Extracellular alkaline phosphatase activity in mineralizing matrices of cartilage and bone: ultrastructural localization using a cerium-based method.
No full textThe ultrastructural localization of alkaline phosphatase (A1P) activity has been demonstrated in epiphyseal growth cartilage and metaphyseal bone of rats. Epiphyso-metaphyseal specimens were decalcified with EDTA and treated with MgCl2 to regenerate the enzymatic activity before incubation in a medium containing beta-glycerophosphate, MgCl2 and CeCl3. A1P activity was present on the outer surface of the plasmamembrane of maturing and hypertrophic chondrocytes and of osteoblasts. Moreover, the reaction product was present in chondrocyte lacunae, in matrix vesicles, and in cartilage matrix, as well as among uncalcified collagen fibrils of osteoid tissue in bone. The intensity of reaction was the lowest, or completely lacking, where the degree of matrix calcification was the highest. These results suggest that alkaline phosphatase is transported from the cells into the cartilage and bone matrix by its association with matrix vesicles and plasmamembrane components, and that its activity in cartilage and bone matrix is inhibited as it is incorporated in the mineral substance
Bone sialoprotein (BSP) secretion and osteoblast differentiation: relationship to bromodeoxyuridine incorporation, alkaline phosphatase, and matrix deposition.
No full textWe defined two distinct maturational compartments (proliferative and secretory) of osteogenic cells in vivo on the basis of ALP activity, BrdU incorporation, cell shape, and BSP production. BSP immunoreactivity was found to mark cells in the secretory but not in the proliferative compartment. We established the phenotypic similarity of primitive marrow stromal cells with proliferating perichondral cells (fibroblast-like, ALP+, BrdU+, BSP-). This suggests the potential functional equivalence of the two cell types as committed non-secretory osteogenic cells and points to the duality of osteogenic cell compartments as a generalized feature of bone formation. We further showed that although BSP secretion is a hallmark of the onset of osteogenesis, BSP antigenicity is lost both in osteoid and in a large proportion of mature osteoblasts during subsequent phases of bone deposition. This suggests that bone formation may not be a uniform event, as bone cells actually deposit antigenically, and likely biochemically, distinct matrices at specific times
Alkaline phosphatase positive precursors of adipocytes in the human bone marrow.
No full textDeveloping fat cells in the bone marrow of leukaemic patients treated with chemotherapy were found to be endowed with membrane-bound alkaline phosphatase. Since alkaline phosphatase is a cytochemical marker of 'reticular' cells, this observation provides cytochemical evidence that reticular cells may convert to adipocytes when marrow cellularity abruptly decrease
Paramyxovirus-like nuclear inclusions identical to those of Paget's disease of bone detected in giant cells of primary oxalosis.
No full textNuclear inclusions, identical to those characteristic of Paget's disease of bone, were observed in giant cells in four of eight cases of primary oxalosis. The giant cells containing nuclear inclusions were directly involved in phagocytosis of large oxalate crystals in the context of typical foreign body granulomas in the bone marrow. Cytochemically, all of them exhibited strong tartrate-resistant acid phosphatase activity, and a proportion of them also tartrate-resistant acid ATPase. The inclusions consisted of typical arrays of filamentous material as described in Paget's disease, admixed with variable proportions of electron-dense material closely reminiscent of nucleolar pars fibrillaris and fibrillary centres. These data indicate: (a) the occurrence of Paget-like inclusions in a bone disease unrelated to Paget's disease, not causally related to viral infection, and resulting from an inborn metabolic derangement; and (b) the occurrence of Paget-like inclusions in foreign body giant cells as opposed to osteoclasts. We suggest that the occurrence of paramyxovirus-like nuclear inclusions in either osteoclasts or giant cells may represent an epiphenomenon of cell fusion and giant cell formation whenever appropriate stimuli act on latently infected precursor cells. Furthermore, our data suggest that nucleoli may represent the specific site of virus-like inclusion formation
lectin binding properties of bovine resting cartilage.
No full textThe aim of this study was to evaluate the differential localisation of glycoconjugates of bovine hyaline cartilage matrix by lectin histochemistry, to compare the results of lectin histochemistry with those that can be obtained in the same tissue with PAS and alcian blue. Frozen and paraffin sections were stained with HE, PAS and alcian blue (pH 1.8). Alcian blue staining was carried out also after 1 and 24 hour digestion with bovine testicular hyaluronidase. Peroxidase conjugated WGA, PNA and RS lectins were tested on all sections before and after 1 hour digestion with bovine testicular hyaluronidase. The results show that all the lectins used in this study react with sugars linked to proteoglycans of territorial matrix, the reaction being increased in territorial, and induced in interterritorial matrix by 1 hour hyaluronidase digestion. Alcian blue at pH 1.8 and PAS were complementary, the former staining territorial, and the latter interterritorial matrix. After 1 hour hyaluronidase digestion, alcian blue stained also the interterritorial matrix. These results suggest that lectins react with low molecular weight proteoglycans and that short hyaluronidase digestion causes depolymerization of high molecular weight proteoglycans without loss of their glucidic components, allowing: a) penetration of alcian blue molecules into the macromolecular proteoglycan network; b) an increase of sugar residuals available for lectin histochemistry. Lectin histochemistry can be useful for differential localisation of glycoconjugates in bovine cartilage, especially if associated with short hyaluronidase digestion and conventional histochemical techniques
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