Histology and histopathology Vol.11, nº 3 (1996)
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- PublicationOpen AccessHuman basophil recovery from secretion. A review emphasizing the distribution of Charcot-Leyden crystal protein in cells stained with the postf ixation electron-dense tracer, cationized ferritin(Murcia : F. Hernández, 1996) Dvorak, A. M.Basophils of two species, guinea pigs and humans, have been shown by ultrastructural analyses to recover from noncytotoxic secretory processes by conservation and synthetic mechanisms. In human basophils, an electron-dense tracer (cationized femtin) used after fixation labels membranes in continuity with plasma membranes at planes of section out of view, thereby indicating internalization of previously externalized granule membranes. Conservation of previously emptied granule containers that remain in the cytoplasm after secretion was associated with reaccumulation of electron-dense particles and condensation of these dense materials therein. Granuleand vesicle-poor, previously stimulated cells developed large numbers of cytoplasmic vesicles beneath plasma membranes, in expanding Golgi areas and in perigranular areas of the cytoplasm. Cytochemical labeling techniques to localize histamine and Charcot-Leyden crystal protein revealed reaccumulation of these two granule proteins in recovering human basophil granules. The mechanism(s) of their recovery likely involves both synthesis of new proteins and conservation by internalization of secreted proteins bound to cell surfaces.
- PublicationOpen AccessUltrastructural localization of S-1 00 protein in rat popliteal lymph nodes, and very slight proliferative activity of follicular dendritic cells(Murcia : F. Hernández, 1996) Sato, H.; Dobashi, MichioThe purposes of this study were to examine the tissue distribution of S-100 protein in rat lymph nodes at the ultrastructural level with respect to the relationship between follicular dendritic cells (FDCs) and antigen transporting cells (ATCs), and to determine whether FDCs increase after secondary stimulation with sheep red blood cells (SRBCs). We examined the ultrastructural localization of S-100 protein in rat popliteal lymph nodes, and the density of S-100 proteinpositive FDCs in lymphoid follicles, after secondary stimulation with SRBCs, on paraffin wax sections. We found S-100 protein expression in FDCs in al1 regions of lymphoid follicles, although FDCs in the central portion of lymphoid follicles showed stronger reactions than FDCs in the periphery. S-100 protein recognized ATCs weakly. At the border between the subsinus layer and the lymphoid follicles, ATCs were very close to FDCs. There were only two mitotic S-100 protein-positive cells in the lymphoid follicles of al1 specimens. The density of S- 100 protein-positive FDCs in the lymphoid follicles in secondary stimulated rats was significantly lower than in primary stimulated rats. We suggest that S-100 protein expression reflects FDC development and supports a close relationship between FDCs and ATCs. FDCs may have only very slight proliferative activity, though the FDC density in the lymphoid follicles decreased after secondary stimulation
- PublicationOpen AccessHistoenzymological detection of sialic acids in the rodent salivary glands(Murcia : F. Hernández, 1996) Accili, Daniela; Gabrielli, M.G.; Menghi, Giovanna; Materazzi, G.Sections from the major salivary glands of rats and mice were used to locate, charactecize and compare sialoglycoconjugates by means of lectin histochemistry, sialidase digestion, periodate oxidation and potassium hydroxide deacetylation. The gland sialylated macromolecules contained the terminal dimers sialic acid-B-galactose and sialic acid-a-N-acetylgalactosamine but differed in the varieties of sialic acids and the linkages of sialic acids to penultimate sugars. Indeed, the submandibular and parotid glands exhibited a notable occurrence of periodate labile sialic acids with C7 andlor C8 andlor C9 acetyl groups in their polyhydroxyl chains. In particular, C9 acetylated sialic acids were mostly linked a2-6 to B-galactose. The sublingual glands, instead, were strongly characterized by a presence of C9 acetylated sialic acids bound a2-3 to B-galactose. Also, sialic acids with O-acetyl substituents at C4 were evident in the mouse parotid gland and in the rat submandibular and sublingual glands. The great variety of sialoderivatives expressed by the rodent salivary glands was correlated with the differential involvement of these compounds in lubricating and defensive processes. Sex-related differences regarding the sialic acid location, acetylation degree and linkage were shown in the submandibular glands of both species.
- PublicationOpen AccessOsteoclast differentiation antigen(Murcia : F. Hernández, 1996) Kukita, T.; Kukita, A.Osteoclasts are the primary cells which perform bone resorption. The origin of these multinucleated giant cells is the haematopoietic stem cells. The differentiation pathway of the osteoclasts has so far been well studied and the cell-lineage of these bone resorbing cells is considered to be close but not identical to the monocytes/macrophages. Owing to the development of in vitro culture systems for evaluating osteoclast differentiation, it has been elucidated that various cytokines are involved in the differentiation of the osteoclasts. However, there is still ambiguity concerning the molecular mechanism of the differentiation of the osteoclasts. One approach for clarifying the molecular mechanism is to find unique antigen molecules involved in the process of osteoclast differentiation. In this review article, we introduce such immunological studies concerning osteoclast differentiation. We also refer to our recent establishment of a panel of monoclonal antibodies recognizing rat osteoclasts. One of the monoclonal antibodies recognizes cell surface antigen (Kat 1 -antigen) expressed on cells in osteoclast-lineage and not on monocytes/macrophages. Cross-linking of the cell surface antigen using this monoclonal antibody showed that the Katl-antigen is the unique cell surface molecule involved in the regulation of the affinity of the calcitonin receptor and also involved in the modulation of the bone resorption. In this review article, we overview, the current issues which should be elucidated for understanding the differentiation and activation of the osteoclasts. We further emphasize the utility of the immunological approach for solving these current target issues.
- PublicationOpen AccessErythrophagocytosis by brown adipocytes of rat interscapular tissue(Murcia : F. Hernández, 1996) Radovanovic, J.; Korac, A.; Davidovic, V.; Koko, V.; Todorovic, V.In this investigation the following phenomena were observed: 1. Rat interscapular brown adipocytes were found to be capable of erythrophagocytosis; 2. Before leaving the capillary lumen, erythrocytes took some material from the blood plasma by endocytosis and passed the endothelial junction canying endocytotic vacuole. Some erythrocytes were in transit: the so-called «head» was in the process of engulfment by brown adipocytes while the rest of the cell had not left the capillary lumen. Fragmentation of erythrocytes was observed during passage through the endothelial junction as well as in the cytoplasm of adipocytes. 3. In some brown adipocytes erythrocytes retained the same shape as in the capillary, but in many cases they exhibited unusual form. Intracytoplasmic erythrocytes were seen in a semithin sections stained with toluidine blue. 4. Erythrocytes either became cells which phagocytized mitochondria and lipid droplets before their transformation into lipofuscin bodies or they were degraded into ferritin-like particles observed (on unstained sections) in the mitochondrial matrix, intercristal space, on the periphery of lipid droplets and in brown adipocyte cytoplasm.