Histology and histopathology Vol.11, nº 4 (1996)
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- PublicationOpen AccessHistochemical aspects of the yol k-sac and digestive tract of larvae of the Senegal sole, Solea senegalensis (Kaup, 1858)(Murcia : F. Hernández, 1996) Sarasquete, C.; Gonzalez de Canales, M.L.; Arellano, J.M.; Muñoz-Cueto, J.A.; Ribeiro, L.; Dinis, M.T.Histochemical distribution of glycoproteins, carbohydrates and proteins rich in different aminoacids were studied using histological and histochemical procedures, in Senegal sole, Solea senegalensis (Kaup, 1858) larvae from hatching until day 15. Glycogen, proteins and glycoproteins were detected in the yolk-sac of the larvae at hatching and during the yolk-resorption. The epithelia1 digestive system (brush border, enterocytes and goblet cells) contained neutral and acid mucins (carboxylated andlor sulphated). Glycogen was observed in the cytoplasm of the digestive absortive cells (enterocytes) and in the liver (hepatocytes) on day 3-4 posthatching. Protein reactions, and specially those that showed proteins rich in arginine, tyrosine and tryptophan, were very intense in the zymogen granules of the pancreatic cells. Oesophageal and intestinal goblet cells contained glucose N-acetyl and sialic acid residues, but the mucin content of these mucous cells did not show affinity towards Con-A, suggesting the absence of glycoproteins with Mannose andlor glucose residues. WGA showed a very intense positivity in the microvilli of the digestive epithelium of the larvae and positive granules for both lectins, specially for Con-A, were detected in the cytoplasm of the anterior intestinal enterocytes.
- PublicationOpen AccessThe role of neuromedin B in the regulation of rat pituitary-adrenocortical function(Murcia : F. Hernández, 1996) Malendowicz, L.K.; Macchi, C.; Nussdorfer, G.G.; Nowak, M.The effects of a 7-day administration of neuromedin B (NMB) andlor ( ~ ~D-rphe~12,)-b ornbesin, an NMB-receptor antagonist (NMB-A) on the function of pituitary-adrenocortical axis were investigated in the rat. NMB raised the plasma concentration of aldosterone, without affecting that of ACTH or corticosterone; the simultaneous administration of NMB-A prevented the effect of NMB. Neither NMB nor NMB-A treatments induced significant changes in adenohypophysis and adrenal weights, nor in the average volume of zona glomerulosa and zona reticularis cells. NMB-A administration lowered the volume of zona fasciculata cells, an effect annulled by the concomitant NMB administration. Our results suggest that NMB specifically stimulates aldosterone secretion, and that endogenous NMB or NMB-like peptides exert a tonic stimulating action on the growth of zona fasciculata cells.
- PublicationOpen AccessHistochemical study of expression of lectin-reactive carbohydrate epitopes and glycoligand-binding sites in normal human appendix vermiformis, colonic mucosa, acute appendicitis and colonic adenoma(Murcia : F. Hernández, 1996) Brinck, U.; Bosbach, R.; Korabiowska, M.; Schauer, A.; Gabius, H.J.In a glycohistochemical analysis of human appendix vermiformis we report the assessment of lectin binding in cells of the Gut Associated Lymphoid Tissue of normal samples and in acute appendicitis using a panel of plant, invertebrate and mammalian lectins with specificity for a-L-Fuc (UEA-I), a-D-Gluc and a-DMan (Con A), a-D-GalNAc (DBA), GalNAc (SBA, HPA), B-Gal (RCA-I, 14 kDa=galectin-l) and a-, B-Gal (VAA). Moreover, we initiate the study of expression of carbohydrate-binding sites in this tissue and in colonic mucosa, employing several types of carrier-immobilized carbohydrate ligands as suitable probes for this purpose. Within the three populations of macrophages intralsubepithelial macrophages of the dome region, the lamina propria of the intercryptal region and the follicleassociated epithelium were apparently reactive with most of the lectins and also with mannose and fucose residues of the tested neoglycoproteins. Distinguishing features of germinal center macrophages in relation to intra-/subepithelia1 phagocytes were the lack of binding of UEA-I and DBA. In comparison to all other types of phagocytes, macrophages of the T-region displayed a rather restricted binding capacity only to Con A and RCA-I. Labeling of macrophages with SBA, HPA and VAA in this location was only rarely found. With respect to dendritic cells no consistently positive reaction was seen for follicular cells, whereas interdigitating cells of the T-region bound Con A, HPA and RCA-I, and, less frequently, SBA. Lymphocytes in all anatomical subsites of the Gut Associated Lymphoid Tissue, centrocytes, centroblasts and plasma cells had binding sites for Con A and RCA-I in common. Notably, a small number of lymphocytes mostly in the T-region but also in B-cell-rich areas expressed intranuclear binding sites for fucose and mannose residues. Intraepithelial lymphocytes and lymphatic cells of the T-region differed from lymphocytes in other regions by a more frequent expression of VAA-binding sites. The epithelium of appendix vermiformis and colonic mucosa not only presents lectin binding sites, but also has the capacity to bind carbohydrate structures, as shown by labeled glycoligand-exposing neoglycoproteins. In normal mucosa the extent of binding appeared to be associated with maturation of cells, the surface epithelium showing the most intense staining reaction. This pattern is not detectable in colonic adenoma which reveal increased intensity, when compared to normal mucosa. In contrast to development of hyperplasia, acute inflammation in appendicitis caused no detectable changes of neoglycoprotein binding. Taking our previous assessment on lectin binding in appendicitis into account, we conclude that glycosylation of goblet cell mucus, but not the capacity to bind certain sugar epitopes responds to inflammatory processes, whereas tumorigenesis of colonic adenoma can also affect the binding of neoglycoproteins.
- PublicationOpen AccessSugar residues content and distribution in atrophic and hyperplastic postmenopausal human endometrium: lectin histochemistry(Murcia : F. Hernández, 1996) Gheri, G.; Gheri Bryk, S.; Taddei, G.; Moncini, D.; Noci, I.A lectin histochemical study was performed to investigate the glycoconjugate saccharidic moieties of the human postmenopausal endometrium (14 atrophic and 15 hyperplastic). For this purpose a battery of seven horseradish peroxidase-conjugated lectins (PNA, SBA, DBA, WGA, ConA, LTA and UEA I) was used. No differences in lectin binding between atrophic and hyperplastic endometria were observed. This investigation allowed us to provide a basic picture of the oligosaccharidic distribution in postmenopausal endometria. The data on the saccharidic distribution at the postmenopausal endometria showed a large amount of sugar residues at all the investigated sites, i.e. the lining and glandular epithelium, the stroma and the vessels (capillary and large vessels). Furthermore, at the endometrial lining epithelium, at the glands and at the wall of the blood vessels of some postmenopausal women the presence of a-L-fucosyl residues which bind via a (1-6) linkage to penultimate glucosaminyl residues andtor difucosylated oligosaccharides was demonstrated for the first time.
- PublicationOpen AccessDescription of primordial germ cells, oogonia, oocytes and embryo-like growth in squash preparations of tissues from hem-atologica malignancies(Murcia : F. Hernández, 1996) Logothetou-Rella, H.This study evidences the presence of primordial germ cells, in tissue squash preparations and sections from hematological malignancies. Primordial germ cells were identified by their morphology, the intense PAS, PAS-D reaction and presence of calciumactivated neutral proteinase. Primordial germ cells gave rise to nuclear vlimata. Immature oogonia exhibited a nuclear envelope and a star-shaped nuclear core, arising from acellular globose bodies impregnated by a nuclear vlima of primordial germ cell. Bone marrow tissue oogonia were PAS and PAS-D positive, identical to fungal ones. Calcium-activated neutral proteinase was demonstrated in the plasma of the acellular globose bodies, the nuclear envelope and the conglomerated primordial germ cells. Immature bone marrow oogonia progressed into mature ones, leptotene, diplotene, dictyotene and mature oocytes. Nuclear vlimata fertilized primordial germ cells, oogonia and oocytes, giving rise to round embryos at the morula and hatching morula-like stages. Embryos consisted of a zonapellucida- like cortex, composed of glycosaminoglycans, glycoproteins, protease and diffuse nuclear material, enclosing developing cells. Primordial germ cells, oogonia and embryos were also demonstrated in squash preparations of adult rat testis and sections of normal rat bone marrow tissues. The observations document that primordial germ cells are the primary stem cells which give rise to nuclear vlimata and oogonia, which constitute the secondary stem germ cells. The results are discussed in terms of stem cell renewal according to the events: primordial germ cells - gametes - fertilization - embryos - primordial germ cells.